WorldWideScience

Sample records for edta science assessment

  1. Chromium-51-EDTA and technetium-99m-DTPA excretion for assessment of small bowel Crohn's disease

    International Nuclear Information System (INIS)

    O'Morain, C.; Chervu, L.; Milstein, D.M.; Das, K.M.

    1984-01-01

    In the present study, 4 patients with radiologically documented Crohn's disease were given 100 μCi of Cr-51-EDTA and 5 mCi of Tc-99m-DTPA together orally in 10ml of water, and urine was collected during the following 24 hr period. Sequential imaging of the stomach and the GI tract was done with a LFOV gamma camera at 10 min intervals until the activity cleared the small bowel. The images failed to show any localization of the activity in any disease process and no extraintestinal accumulation site was observed scintigraphically. Mean 24 hr urinary excretion for Tc-99m-DTPA was 4.8 +- 2.6% comparable to that of Cr-51-EDTA in these patients. This study suggests that a comparable oral dose of Tc-99m-DTPA could be substituted for Cr-51-EDTA as a far more readily available agent for documenting small bowel Crohn's disease by quantitative assessment of its urinary excretion

  2. Assessment of glomerular filtration rate in diabetic nephropathy using the plasma clearance of 51Cr-EDTA

    DEFF Research Database (Denmark)

    Hansen, H P; Rossing, P; Mathiesen, E R

    1998-01-01

    Plasma clearance of 51Cr-EDTA is widely used to assess the glomerular filtration rate (GFR) in diabetic nephropathy. Originally, the ratio between the intravenously injected amount of tracer and the total area under the plasma concentration curve was used for the calculation of total 51Cr...... and rate of decline in GFR based upon these three methods. Bland & Altman plots were used to illustrate the range of agreement. We investigated 76 insulin-dependent diabetic (IDDM) patients with microalbuminuria or diabetic nephropathy. GFR was measured after a single intravenous injection of 3.7 MBq 51Cr...

  3. Assessment in Science Education

    Science.gov (United States)

    Rustaman, N. Y.

    2017-09-01

    An analyses study focusing on scientific reasoning literacy was conducted to strengthen the stressing on assessment in science by combining the important of the nature of science and assessment as references, higher order thinking and scientific skills in assessing science learning as well. Having background in developing science process skills test items, inquiry in its many form, scientific and STEM literacy, it is believed that inquiry based learning should first be implemented among science educators and science learners before STEM education can successfully be developed among science teachers, prospective teachers, and students at all levels. After studying thoroughly a number of science researchers through their works, a model of scientific reasoning was proposed, and also simple rubrics and some examples of the test items were introduced in this article. As it is only the beginning, further studies will still be needed in the future with the involvement of prospective science teachers who have interests in assessment, either on authentic assessment or in test items development. In balance usage of alternative assessment rubrics, as well as valid and reliable test items (standard) will be needed in accelerating STEM education in Indonesia.

  4. Assessing Glomerular Filtration in Small Animals Using [68Ga]DTPA and [68Ga]EDTA with PET Imaging.

    Science.gov (United States)

    Gündel, Daniel; Pohle, Ulrike; Prell, Erik; Odparlik, Andreas; Thews, Oliver

    2018-06-01

    Determining the glomerular filtration rate (GFR) is essential for clinical medicine but also for pre-clinical animal studies. Functional imaging using positron emission tomography (PET) allows repetitive almost non-invasive measurements. The aim of the study was the development and evaluation of easily synthesizable PET tracers for GFR measurements in small animals. Diethylenetriaminepentaacetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA) were labeled with Ga-68. The binding to blood cells and plasma proteins was tested in vitro. The distribution of the tracers in rats was analyzed by PET imaging and ex vivo measurements. From the time-activity-curve of the blood compartment (heart) and the total tracer mass excreted by the kidney, the GFR was calculated. These values were compared directly with the inulin clearance in the same animals. Both tracers did not bind to blood cells. [ 68 Ga]DPTA but not [ 68 Ga]EDTA showed strong binding to plasma proteins. For this reason, [ 68 Ga]DPTA stayed much longer in the blood and only 30 % of the injected dose was eliminated by the kidney within 60 min whereas the excretion of [ 68 Ga]EDTA was 89 ± 1 %. The calculated GFR using [ 68 Ga]EDTA was comparable to the measured inulin clearance in the same animal. Using [ 68 Ga]-DPTA, the measurements led to values which were 80 % below the normal GFR. The results also revealed that definition of the volume of interest for the blood compartment affects the calculation and may lead to a slight overestimation of the GFR. [ 68 Ga]EDTA is a suitable tracer for GFR calculation from PET imaging in small animals. It is easy to be labeled, and the results are in good accordance with the inulin clearance. [ 68 Ga]DTPA led to a marked underestimation of GFR due to its strong binding to plasma proteins and is therefore not an appropriate tracer for GFR measurements.

  5. Assessing Ethics in Secondary Science

    Science.gov (United States)

    Reiss, Michael J.

    2011-01-01

    An increasing number of science courses now include consideration of the ethical implications of science. However, there is little agreement about how ethical reasoning in science should be assessed. This article highlights the conclusions of a seminar on the assessment of ethics in science that was organized by the Nuffield Foundation Curriculum…

  6. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2005-01-01

    The complexation of radionuclides (e.g., plutonium (Pu) and 60 Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH) 3 (s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop Pu

  7. EDTA-S: A novel root conditioning agent

    Directory of Open Access Journals (Sweden)

    S Srirangarajan

    2012-01-01

    Full Text Available Background: To evaluate the efficacy of 15% ethylenediaminetetraacetic acid (EDTA-S (EDTA with soft soap preparation for the removal of smear layer at human root surfaces. Materials and Methods: Twenty teeth indicated for extraction due to periodontal disease were sectioned using high speed cylindrical bur under copious irrigation. The root surfaces were instrumented with Gracey 7-8 curette (Hu-Friedy, 12 times to induce an "experimental smear layer". Following root planning, the root surface was cut using diamond disc and separated from the crown. Samples were randomly distributed into five groups. One group was control, saline and test groups were EDTA 15% alone, by active and passive applications (groups 2 and 3, and EDTA 15%+soft soap, by active and passive applications (groups 4 and 5. Specimens were then subjected to scanning electron microscope study. Smear layer removal was evaluated according to Sampaio et al., index. Results: EDTA-S removed the smear layer better than plain EDTA and the control group, while active application of the root conditioning agent had significant difference than the passive application of the agent. Conclusion: EDTA-S has favorable benefits over EDTA alone, and active application is better in comparison with passive application of root conditioning agent. Clinical Relevance: Removal of smear layer has been considered as an important step in periodontal regenerative therapy. Scaling and root planning alone with saline irrigation does not remove the smear layer. EDTA is a commonly used root conditioning agent in periodontal therapy. The addition of a detergent to EDTA proved to remove smear layer more efficiently than EDTA alone.

  8. Phytoextraction of Pb and Cu contaminated soil with maize and microencapsulated EDTA.

    Science.gov (United States)

    Xie, Zhiyi; Wu, Longhua; Chen, Nengchang; Liu, Chengshuai; Zheng, Yuji; Xu, Shengguang; Li, Fangbai; Xu, Yanling

    2012-09-01

    Chelate-assisted phytoextraction using agricultural crops has been widely investigated as a remediation technique for soils contaminated with low mobility potentially toxic elements. Here, we report the use of a controlled-release microencapsulated EDTA (Cap-EDTA) by emulsion solvent evaporation to phytoremediate soil contaminated with Pb and Cu. Incubation experiments were carried out to assess the effect of Cap- and non-microencapsulated EDTA (Ncap-EDTA) on the mobility of soil metals. Results showed EDTA effectively increased the mobility of Pb and Cu in the soil solution and Cap-EDTA application provided lower and more constant water-soluble concentrations of Pb and Cu in comparison with. Phytotoxicity may be alleviated and plant uptake of Pb and Cu may be increased after the incorporation of Cap-EDTA. In addition phytoextraction efficiencies of maize after Cap- and Ncap-EDTA application were tested in a pot experiment. Maize shoot concentrations of Pb and Cu were lower with Cap-EDTA application than with Ncap-EDTA. However, shoot dry weight was significantly higher with Cap-EDTA application. Consequently, the Pb and Cu phytoextraction potential of maize significantly increased with Cap-EDTA application compared with the control and Ncap-EDTA application.

  9. Peer Assessment of Elementary Science Teaching Skills

    Science.gov (United States)

    Kilic, Gulsen Bagci; Cakan, Mehtap

    2007-01-01

    In this study, peer assessment was applied in assessing elementary science teaching skills. Preservice teachers taught a science topic as a team to their peers in an elementary science methods course. The peers participating in the science lesson assessed teacher-groups' elementary science teaching skills on an assessment form provided by the…

  10. Life Sciences Centrifuge Facility assessment

    Science.gov (United States)

    Benson, Robert H.

    1994-01-01

    This report provides an assessment of the status of the Centrifuge Facility being developed by ARC for flight on the International Space Station Alpha. The assessment includes technical status, schedules, budgets, project management, performance of facility relative to science requirements, and identifies risks and issues that need to be considered in future development activities.

  11. Changes in metal mobility assessed by EDTA kinetic extraction in three polluted soils after repeated phytoremediation using a cadmium/zinc hyperaccumulator.

    Science.gov (United States)

    Li, Zhu; Wu, Longhua; Luo, Yongming; Christie, Peter

    2018-03-01

    Phytoextraction is one of the most promising technologies for the decontamination of metal-polluted agricultural soils. Effects of repeated phytoextraction by the cadmium (Cd)/zinc (Zn) hyperaccumulator Sedum plumbizincicola on metal (Cd, Zn, copper (Cu) and lead (Pb)) mobility were investigated in three contaminated soils with contrasting properties. EDTA kinetic extraction and the two first-order reactions model showed advantages in the assessment of soil metal mobility and clearly discriminated changes in metal fractions induced by phytoextraction. Repeated phytoextraction led to large decreases in readily labile (Q 1 0 ) and less labile (Q 2 0 ) fractions of Cd and Zn in all three soils with the sole exception of an increase in the Q 2 0 of Zn in the highly polluted soil. However, Q 1 0 fractions of soil Cu and Pb showed apparent increases with the sole exception of Pb in the acid polluted soil but showed a higher desorption rate constant (k 1 ). Furthermore, S. plumbizincicola decreased the non-labile fraction (Q 3 0 ) of all metals tested, indicating that the hyperaccumulator can redistribute soil metals from non-labile to labile fractions. This suggests that phytoextraction decreased the mobility of the metals hyperaccumulated by the plant (Cd and Zn) but increased the mobility of the metals not hyperaccumulated (Cu and Pb). Thus, phytoextraction of soils contaminated with mixtures of metals must be performed carefully because of potential increases in the mobility of non-hyperaccumulated metals in the soil and the consequent environmental risks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Hydroxyapatite synthesis using EDTA.

    Science.gov (United States)

    Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

    2013-05-01

    Bone comprises structure of the body and consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self-healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite (Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite; however, economical cost and being time consuming make the production difficult. In this study, we synthesized hydroxyapatite with EDTA. Freeze-dried bone allograft (Hans Biomed) was used as the control group. Synthesized hydroxyapatite was a rod-shaped, white powdery substance with 2- to 5-μm length and 0.5- to 1-μm width. X-ray diffraction showed the highest sharp peak at 32°C and high peaks at 25.8°C, 39.8°C, 46.8°C, 49.5°C, and 64.0°C, indicating a similar substance to the freeze-dried bone allograft. After 3 days, the cell growth of synthesized hydroxyapatite showed 1.5-fold more than did the bone allograft. Cellular and media alkaline phosphate activity increased similar to the bone allograft. In this study, we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also, the product can be manufactured in large quantity. It can be also transformed into scaffold structure, which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products.

  13. Relevance of EDTA carryover during blood collection.

    Science.gov (United States)

    Cadamuro, Janne; Felder, Thomas Klaus; Oberkofler, Hannes; Mrazek, Cornelia; Wiedemann, Helmut; Haschke-Becher, Elisabeth

    2015-07-01

    The order of draw is regarded as a preanalytical issue to prevent carryover of additives during blood collection. Our objective was to prove the theory of ethylenediaminetetraacetic acid (EDTA) carryover for a closed vacuum system and the influence of EDTA on concentrations of selected biomarkers. To test the carryover of EDTA, a blood collection with tripotassium EDTA (K3EDTA) and subsequent non-additive tubes was simulated using distilled water as substitute for blood. EDTA concentrations were measured by tandem mass spectrometry. Then we added increasing concentrations of EDTA to heparinized blood and measured routine biomarkers, thereby simulating a carryover of EDTA whole blood and pure EDTA, respectively. Additionally, we tested for EDTA contamination and biomarker alteration in samples collected from 10 healthy volunteers by a syringe with subsequent transfer into sample tubes. No EDTA contamination was detected in samples collected subsequent to a K3EDTA tube when adhering to guidelines of blood sampling. Magnesium, calcium, and potassium levels were altered by artificial K3EDTA whole-blood contamination as well as when adding 1 μL pure K3EDTA. Iron values were altered at EDTA concentrations of 4.4 mmol/L. All other parameters remained unaffected. A slight EDTA carryover was observed in syringe collection and subsequent transfer into EDTA and heparin tubes, however, without any biomarker alteration. An EDTA carryover during blood collection using a closed vacuum system is highly unlikely. Even if carryover of EDTA whole blood occurs, an absolute volume larger than 10 μL would be necessary to alter test results. However, contamination of samples with preloaded pure K3EDTA solution by severe neglect of current recommendations in blood collection may significantly alter testing results.

  14. Valid and Reliable Science Content Assessments for Science Teachers

    Science.gov (United States)

    Tretter, Thomas R.; Brown, Sherri L.; Bush, William S.; Saderholm, Jon C.; Holmes, Vicki-Lynn

    2013-01-01

    Science teachers' content knowledge is an important influence on student learning, highlighting an ongoing need for programs, and assessments of those programs, designed to support teacher learning of science. Valid and reliable assessments of teacher science knowledge are needed for direct measurement of this crucial variable. This paper…

  15. The ERA-EDTA today and tomorrow: a progress document by the ERA-EDTA Council.

    Science.gov (United States)

    Zoccali, Carmine; Arici, Mustafa; Blankestijn, Peter J; Bruchfeld, Annette; Capasso, Giovambattista; Fliser, Danilo; Fouque, Denis; Goumenos, Dimitrios; Ketteler, Markus; Malyszko, Jolanta; Massy, Ziad; Rychlík, Ivan; Spasovski, Goce

    2018-05-23

    Scientific societies are increasingly seen as central to the advancement of information sharing and collaboration among scientists and clinical investigators for the progress of medical research and the promotion of education, professional competence, integrity and quality studies. To more effectively serve the practicing nephrologists and investigators dedicated to renal science, the Council of the European Renal Association and European Dialysis and Transplantation Association (ERA-EDTA) reorganized and integrated the various activities of the society into two branches, the Clinical Nephrology Governance branch and the Renal Science branch. New affordable initiatives to promote research, education and professional development and to advocate for the recognition of chronic kidney disease as a major public health issue at the European level will be put in place and/or potentiated in the new organizational frame. Educational initiatives will be espoused to Continuous Professional Development and, starting from 2019, 14 Education & Continuous Professional Development courses will be held covering the full range of knowledge areas of modern nephrology. Consolidation and development is the short- and medium-term mantra of the ERA-EDTA. The society has a rich portfolio of successful activities and brilliant, creative scientists among its members. Integrating the various activities of the ERA-EDTA and treasuring the expertise and wisdom of its most accomplished members will facilitate collaborative research, education and its public impact at large.

  16. Hormesis in Regulatory risk assessment - Science and Science Policy.

    Science.gov (United States)

    Gray, George

    2011-01-01

    This brief commentary will argue that whether hormesis is considered in regulatory risk assessment is a matter less of science than of science policy. I will first discuss the distinction between science and science policy and their roles in regulatory risk assessment. Then I will focus on factors that influence science policy, especially as it relates to the conduct of risk assessments to inform regulatory decisions, with a focus on the U.S. Environmental Protection Agency (EPA). The key questions will then be how does hormesis interact with current concepts of science and science policy for risk assessment? Finally, I look ahead to factors that may increase, or decrease, the likelihood of hormesis being incorporated into regulatory risk assessment.

  17. EDTA-assisted Pb phytoextraction.

    Science.gov (United States)

    Saifullah; Meers, E; Qadir, M; de Caritat, P; Tack, F M G; Du Laing, G; Zia, M H

    2009-03-01

    Pb is one of the most widespread and metal pollutants in soil. It is generally concentrated in surface layers with only a minor portion of the total metal found in soil solution. Phytoextraction has been proposed as an inexpensive, sustainable, in situ plant-based technology that makes use of natural hyperaccumulators as well as high biomass producing crops to help rehabilitate soils contaminated with heavy metals without destructive effects on soil properties. The success of phytoextraction is determined by the amount of biomass, concentration of heavy metals in plant, and bioavailable fraction of heavy metals in the rooting medium. In general, metal hyperaccumulators are low biomass, slow growing plant species that are highly metal specific. For some metals such as Pb, there are no hyperaccumulator plant species known to date. Although high biomass-yielding non-hyperaccumulator plants lack an inherent ability to accumulate unusual concentrations of Pb, soil application of chelating agents such as EDTA has been proposed to enhance the metal concentration in above-ground harvestable plant parts through enhancing the metal solubility and translocation from roots to shoots. Leaching of metals due to enhanced mobility during EDTA-assisted phytoextraction has been demonstrated as one of the potential hazards associated with this technology. Due to environmental persistence of EDTA in combination with its strong chelating abilities, the scientific community is moving away from the use of EDTA in phytoextraction and is turning to less aggressive alternative strategies such as the use of organic acids or more degradable APCAs (aminopolycarboxylic acids). We have therefore arrived at a point in phytoremediation research history in which we need to distance ourselves from EDTA as a proposed soil amendment within the context of phytoextraction. However, valuable lessons are to be learned from over a decade of EDTA-assisted phytoremediation research when considering the

  18. Students Explaining Science--Assessment of Science Communication Competence

    Science.gov (United States)

    Kulgemeyer, Christoph; Schecker, Horst

    2013-01-01

    Science communication competence (SCC) is an important educational goal in the school science curricula of several countries. However, there is a lack of research about the structure and the assessment of SCC. This paper specifies the theoretical framework of SCC by a competence model. We developed a qualitative assessment method for SCC that is…

  19. Effect of the association between citric acid and EDTA on root surface etching.

    Science.gov (United States)

    Manzolli Leite, Fabio Renato; Nascimento, Gustavo Giacomelli; Manzolli Leite, Elza Regina; Leite, Amauri Antiquera; Cezar Sampaio, Josá Eduardo

    2013-09-01

    This study aims to compare the clot stabilization on root surfaces conditioned with citric acid and ethylenediamine-tetraacetic acid (EDTA). Scaled root samples (n = 100) were set in fve groups: group I-control group (saline solution); group II (24% EDTA); group III (25% citric acid); group IV (EDTA + citric acid); group V (citric acid + EDTA). Fifty samples were assessed using the root surface modifcation index (RSMI). The other 50 received a blood drop after conditioning. Clot formation was assessed using blood elements adhesion index (BEAI). A blind examiner evaluated photomicrographs. Statistical analysis considered p EDTA employment before citric acid (group-IV) reduced clot formation in comparison to citric acid use alone (group-III). Root conditioning with citric acid alone and before EDTA had the best results for smear layer removal and clot stabilization. EDTA inhibited clot stabilization on root surface and must have a residual activity once it has diminished clot adhesion to root even after citric acid conditioning. Thus, EDTA can be used to neutralize citric acid effects on periodontal cells without affecting clot stabilization. Clinical signifcance: To demonstrate that citric acid use on root surfaces previously affected by periodontal disease may favor clot stabilization and may have a benefcial effect on surgical outcomes. Also, EDTA can be used to neutralize citric acid effects on periodontal cells.

  20. EDTA chelation therapy for cardiovascular disease: a systematic review

    Directory of Open Access Journals (Sweden)

    Wu Ping

    2005-11-01

    Full Text Available Abstract Background Numerous practitioners of both conventional and complementary and alternative medicine throughout North America and Europe claim that chelation therapy with EDTA is an effective means to both control and treat cardiovascular disease. These claims are controversial, and several randomized controlled trials have been completed dealing with this topic. To address this issue we conducted a systematic review to evaluate the best available evidence for the use of EDTA chelation therapy in the treatment of cardiovascular disease. Methods We conducted a systematic review of 7 databases from inception to May 2005. Hand searches were conducted in review articles and in any of the trials found. Experts in the field were contacted and registries of clinical trials were searched for unpublished data. To be included in the final systematic review, the studies had to be randomized controlled clinical trials. Results A total of seven articles were found assessing EDTA chelation for the treatment of cardiovascular disease. Two of these articles were subgroup analyses of one RCT that looked at different clinical outcomes. Of the remaining five studies, two smaller studies found a beneficial effect whereas the other three exhibited no benefit for cardiovascular disease from the use of EDTA chelation therapy. Adverse effects were rare but those of note included a few cases of hypocalcemia and a single case of increased creatinine in a patient on the EDTA intervention. Conclusion The best available evidence does not support the therapeutic use of EDTA chelation therapy in the treatment of cardiovascular disease. Although not considered to be a highly invasive or harmful therapy, it is possible that the use of EDTA chelation therapy in lieu of proven therapy may result in causing indirect harm to the patient.

  1. Making Sense of New Science Assessments

    Science.gov (United States)

    Pellegrino, James W.

    2016-01-01

    What we choose to assess in science is what will end up being the focus of instruction. US science standards once treated content and inquiry as fairly separate strands of science learning, with content standards stating what students should know and inquiry standards stating what they should be able to do. In its content coverage, these standards…

  2. Exploring alternative assessment strategies in science classrooms

    Directory of Open Access Journals (Sweden)

    Michèle Stears

    2010-01-01

    Full Text Available The knowledge children bring to the classroom or construct in the classroom may find expression in a variety of activities and is often not measurable with the traditional assessment instruments used in science classrooms. Different approaches to assessment are required to accommodate the various ways in which learners construct knowledge in social settings. In our research we attempted to determine the types of outcomes achieved in a Grade 6 classroom where alternative strategies such as interactive assessments were implemented. Analyses of these outcomes show that the learners learned much more than the tests indicate, although what they learnt was not necessarily science. The implications for assessment are clear: strategies that assess knowledge of science concepts, as well as assessment of outcomes other than science outcomes, are required if we wish to gain a holistic understanding of the learning that occurs in science classrooms.

  3. Transport of EDTA into cells of the EDTA-degrading bacterial strain DSM 9103.

    Science.gov (United States)

    Witschel, M; Egli, T; Zehnder, A J; Wehrli, E; Spycher, M

    1999-04-01

    In the bacterial strain DSM 9103, which is able to grow with the complexing agent EDTA as the sole source of carbon, nitrogen and energy, the transport of EDTA into whole cells was investigated. EDTA uptake was found to be dependent on speciation: free EDTA and metal-EDTA complexes with low stability constants were readily taken up, whereas those with stability constants higher than 1016 were not transported. In EDTA-grown cells, initial transport rates of CaEDTA showed substrate-saturation kinetics with a high apparent affinity for CaEDTA (affinity constant Kt= 0.39 microM). Several uncouplers had an inhibitory effect on CaEDTA transport. CaEDTA uptake was also significantly reduced in the presence of an inhibitor of ATPase and the ionophore nigericin, which dissipates the proton gradient. Valinomycin, however, which affects the electrical potential, had little effect on uptake, indicating that EDTA transport is probably driven by the proton gradient. Of various structurally related compounds tested only Ca2+-complexed diethylenetriaminepentaacetate (CaDTPA) competitively inhibited CaEDTA transport. Uptake in fumarate-grown cells was low compared to that measured in EDTA-grown bacteria. These results strongly suggest that the first step in EDTA degradation by strain DSM 9103 consists of transport by an inducible energy-dependent carrier. Uptake experiments with 45Ca2+ in the presence and absence of EDTA indicated that Ca2+ is transported together with EDTA into the cells. In addition, these transport studies and electron-dispersive X-ray analysis of electron-dense intracellular bodies present in EDTA-grown cells suggest that two mechanisms acting simultaneously allow the cells to cope with the large amounts of metal ions taken up together with EDTA. In one mechanism the metal ions are excreted, in the other they are inactivated intracellularly in polyphosphate granules.

  4. Assessing mathematics within advanced school science qualifications

    OpenAIRE

    McAlinden, Mary; Noyes, Andrew

    2017-01-01

    Following sustained discussion regarding the relationship between advanced mathematics and science learning in England, the government has pursued a reform agenda in which mathematics is embedded in national, high stakes A-level science qualifications and their assessments for 18-year-olds. For example, A-level Chemistry must incorporate the assessment of relevant mathematics for at least 20% of the qualification. Other sciences have different mandated percentages. This embedding policy is ru...

  5. Data Science in Educational Assessment

    Science.gov (United States)

    Gibson, David C.; Webb, Mary E.

    2015-01-01

    This article is the second of two articles in this special issue that were developed following discussions of the Assessment Working Group at EDUsummIT 2013. The article extends the analysis of assessments of collaborative problem solving (CPS) to examine the significance of the data concerning this complex assessment problem and then for…

  6. Radiologic sciences. Faculty needs assessment.

    Science.gov (United States)

    Powers, Kevin J

    2005-01-01

    A total of 326 programs are represented in the data collected. Based on the average number of full- and part-time faculty members reported per program, this survey represents more than 1500 faculty positions. Based on the forecast of retirement and career change for all faculty members, there will be a turnover of 700 to 800 positions over the next 5 to 10 years. Part-time/adjunct faculty vacancies are expected to create the greatest number of opportunities for technologists to make the transition to education, with approximately one third of current part-time/adjunct educators planning on leaving radiologic sciences education within 5 years. To encourage retention of part-time/adjunct educators, annual evaluations should be modified to recognize the important educational role these instructors play. There is a need to create enthusiasm and interest in education as a career pathway for radiologic technologists. Resources are needed that help radiologic technologists make the transition to teaching. Finally, the retention of educators must be emphasized. Program applicant trends indicate radiologic technology students are older, have prior postsecondary education experience or are making a career change. This data emphasizes the need for educators, both full time and part time, to understand the characteristics and needs of the adult learner. Adult learners bring a wealth of education, experience and life skills that create both opportunities and challenges in the classroom and clinical setting. All categories of respondents indicated that their current salaries were greater than those of program graduates in their firstjob. Of interest is that 1 in 5 (20%) of part-time/adjunct educators indicated the opposite--that program graduates earn more in their firstjob than educators earn. When asked about salaries if working full time in clinical practice, the majority of all groups indicated their salary would be about the same or would decrease. Only 20% of program

  7. Effects of Na4EDTA and EDTA on seeded precipitation of sodium aluminate solution

    Institute of Scientific and Technical Information of China (English)

    吕保林; 陈启元; 尹周澜; 胡慧萍

    2010-01-01

    Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.

  8. Fusion Nuclear Science Pathways Assessment

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Kessel, et. al.

    2012-02-23

    With the strong commitment of the US to the success of the ITER burning plasma mission, and the project overall, it is prudent to consider how to take the most advantage of this investment. The production of energy from fusion has been a long sought goal, and the subject of several programmatic investigations and time line proposals [1]. The nuclear aspects of fusion research have largely been avoided experimentally for practical reasons, resulting in a strong emphasis on plasma science. Meanwhile, ITER has brought into focus how the interface between the plasma and engineering/technology, presents the most challenging problems for design. In fact, this situation is becoming the rule and no longer the exception. ITER will demonstrate the deposition of 0.5 GW of neutron heating to the blanket, deliver a heat load of 10-20 MW/m2 or more on the divertor, inject 50-100 MW of heating power to the plasma, all at the expected size scale of a power plant. However, in spite of this, and a number of other technologies relevant power plant, ITER will provide a low neutron exposure compared to the levels expected to a fusion power plant, and will purchase its tritium entirely from world reserves accumulated from decades of CANDU reactor operations. Such a decision for ITER is technically well founded, allowing the use of conventional materials and water coolant, avoiding the thick tritium breeding blankets required for tritium self-sufficiency, and allowing the concentration on burning plasma and plasma-engineering interface issues. The neutron fluence experienced in ITER over its entire lifetime will be ~ 0.3 MW-yr/m2, while a fusion power plant is expected to experience 120-180 MW-yr/m2 over its lifetime. ITER utilizes shielding blanket modules, with no tritium breeding, except in test blanket modules (TBM) located in 3 ports on the midplane [2], which will provide early tests of the fusion nuclear environment with very low tritium production (a few g per year).

  9. Sodium citrate blood contamination by K2 -ethylenediaminetetraacetic acid (EDTA): impact on routine coagulation testing.

    Science.gov (United States)

    Lima-Oliveira, G; Salvagno, G L; Danese, E; Favaloro, E J; Guidi, G C; Lippi, G

    2015-06-01

    The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen. Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. © 2014 John Wiley & Sons Ltd.

  10. K2-EDTA and K3-EDTA Greiner Tubes for HbA1c Measurement.

    Science.gov (United States)

    Vrtaric, Alen; Filipi, Petra; Hemar, Marina; Nikolac, Nora; Simundic, Ana-Maria

    2016-02-01

    To determine whether K2-ethylenediaminetetraacetic acid (EDTA) and K3-EDTA Greiner tubes could be used interchangeably for glycosylated hemoglobin, type A1C (HbA1c) measurement via the Abbott Laboratories ARCHITECT chemiluminescent microparticle HbA1c assay on the ARCHITECT i2000SR immunoanalyzer at our university hospital. We drew blood from a total of 45 outpatients into plastic Greiner Vacuette tubes, some of which were lined with K2-EDTA and others with K3-EDTA anticoagulant. Data are presented as median and interquartile range values. We used the Wilcoxon test and Passing-Bablok regression for tube comparison. For K2-EDTA tubes median HbA1c concentration was 54 mmol/mol (41 to 71 mmol/mol) and for K3-EDTA tubes 56 mmol/mol (43 to 69 mmol/mol). There was no statistically significant difference between K2-EDTA and K3-EDTA (bias= -1.29 mmol/mol; P = 0.24). Passing-Bablok regression showed that there is no constant and proportional error: y = -0.23 (95% CI[-3.52 to 0.69]) + 1.00( 95% CI[0.98 to 1.06]) x. In this study, we provide evidence for the lack of any clinically and statistically significant bias between K2-EDTA and K3-EDTA HbA1c measurements. Thus, Greiner tubes lined with K2-EDTA and those lined with K3-EDTA can safely be used interchangeably to measure HbA1c via the Abbott Laboratories ARCHITECT assay. © American Society for Clinical Pathology, 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Decontamination effectiveness of mixtures of citric acid, oxalic acid and EDTA

    International Nuclear Information System (INIS)

    Speranzini, R.A.

    1990-01-01

    An experimental study of the decontamination effectiveness of citric acid, oxalic acid and EDTA mixtures was conducted to assess whether oxalic acid could be removed from decontamination solutions to minimize corrosion. In loop experiments, radioactive specimens from two boiling water reactors and one pressurized water reactor were suspended in solutions of single acids or in mixtures of reagents at total reagent concentrations of less than 0.1 wt% under conditions similar to those used to decontaminate reactor systems. Rate constants for dissolution of oxides and decontamination factors were measured. Based on the results, it was concluded that under certain conditions, oxalic acid was the most effective reagent for the dissolution of oxides. It was also found, however, that conditions under which effective dissolution occurred in solutions of oxalic acid and/or citric acid were difficult to define and control. EDTA was found to be an effective reagent for dissolution of oxides such that rates of dissolution in EDTA containing solutions at 117 degrees Celsius were comparable to rates in oxalic acid containing solutions. At 90 degrees Celsius, EDTA acted synergistically with oxalic acid such that the rate of dissolution of oxides in citric-acid/oxalic-acid/EDTA solutions was higher than in citric-acid/EDTA solutions. The rates of dissolution of oxides were significantly reduced when 60 mg/kg of ferric ion was added to the citric-acid/oxalic-acid, citric-acid/EDTA and citric-acid/oxalic-acid/EDTA solutions. It was concluded that effective decontaminations of BWR and PWR systems could be achieved with mixtures of citric acid and EDTA

  12. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Xun, Luying; Bolton, Jr. Harvey

    2001-01-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation

  13. Science assessment of fusion power plant

    International Nuclear Information System (INIS)

    Nagai, Toru; Shimazu, Yasuo

    1984-01-01

    A concept of SCIENCE ASSESSMENT (SA) is proposed to support a research program of the so-called big science. The SA System should be established before the demonstration reactor is realized, and the system is classified into four categories: (1) Resource Economy Assessment (REA) (cost evaluation and availability of rare resource materials), (2) Risk Assessment (RA) (structural safety during operation and accident), (3) Environmental Assessment (EA) (adaptability to environments), and (4) Socio-Political Assessment (SPA) (from local public acceptance to national policy acceptance). Here, REA to the published conceptual designs of commercial fusion power plants (most of them are TOKAMAK) is carried out as the first step. The energy analysis method is imployed because the final goal of fusion plant is to supply energy. The evaluation index is the energy ratio (= output/input). Computer code for energy analysis was developed, to which the material inventory table from the conceptual design and the database for the energy intensity (= energy required to obtain a unit amount of materials) were prepared. (Nogami, K.)

  14. Carbon dioxide sorption on EDTA modified halloysite

    Directory of Open Access Journals (Sweden)

    Waszczuk Patrycja

    2016-01-01

    Full Text Available In this paper the sorption study of CO2 on EDTA surface modified halloysite was conducted. In the paper chemical modification of halloysite from the Dunino deposit (Poland and its influence on sorption of CO2 are presented. A halloysite samples were washed with water-EDTA 1% solution, centrifuged to separate liquid and impurities and dried. The samples were tested for the sorption capacity using a manometric method with pressure up to 3 MPa. A Langmuir adsorption model was fitted to the data. The results showed that EDTA had a limited effect on the increase of sorption potential at low pressure and the samples exhibited similar results to that ones treated solely with the water solution.

  15. Crown ether derivatives of EDTA: Pt. 6

    International Nuclear Information System (INIS)

    Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

    1988-01-01

    EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

  16. Effect of NaFeEDTA-Fortified Soy Sauce on Anemia Prevalence in China: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Huo, Jun Sheng; Yin, Ji Yong; Sun, Jing; Huang, Jian; Lu, Zhen Xin; Regina, Moench-Pfanner; Chen, Jun Shi; Chen, Chun Ming

    2015-11-01

    To assess the effect of sodium iron ethylenediaminetetraacetate (NaFeEDTA)-fortified soy sauce on anemia prevalence in the Chinese population. A systematic review was performed to identify potential studies by searching the electronic databases of PubMed, Cochrane Library, WHO Library, HighWire, CNKI, and other sources. The selection criteria included randomized controlled trials that compared the efficacy of NaFeEDTA-fortified soy sauce with that of non-fortified soy sauce. Anemia rates and hemoglobin levels were the outcomes of interest. Inclusion decisions, quality assessment, and data extraction were performed by two reviewers independently. A total of 16 studies met the inclusion criteria for anemia rate analysis, of which 12 studies met the inclusion criteria for hemoglobin analysis. All included studies assessed the effect of NaFeEDTA-fortified soy sauce on anemia rates and hemoglobin concentrations. After the intervention, the hemoglobin concentration increased and anemia rates decreased significantly as compared with the non-fortified soy sauce groups. For anemia rates, data from 16 studies could be pooled, and the pooled estimate odds ratio was 0.25 (95% CI 0.19-0.35). For hemoglobin concentrations, data from 12 studies could be pooled, and the pooled weighted mean difference was 8.81 g/L (95% CI 5.96-11.67). NaFeEDTA-fortified soy sauce has a positive effect on anemia control and prevention in the at-risk population. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  17. Anaerobic Biotransformation and Mobility of Pu and PuEDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2005-01-01

    The objective of this report is to isolate anaerobic EDTA-degrading bacteria. Although our goal is to isolate anaerobic EDTA degraders, we initiated the experiments to include nitrilotriacetate (NTA), which is a structure homologue of EDTA. All the aerobic EDTA degraders can degrade NTA, but the isolated NTA degraders cannot degrade EDTA. Since NTA is a simpler structure homologue, it is likely that EDTA-degrading ability is evolved from NTA degradation. This hypothesis is further supported from our characterization of EDTA and NTA-degrading enzymes and genes (J. Bact. 179:1112-1116; and Appl. Environ. Microbiol. 67:688-695). The EDTA monooxygenase and NTA monooxygenase are highly homologous. EDTA monooxygenase can use both EDTA and NTA as substrates, but NTA monooxygenase can only use NTA as a substrate. Thus, we put our effort to isolate both NTA and EDTA degraders. In case, an anaerobic EDTA degrader is not immediately enriched, we will try to evolve the NTA degraders to use EDTA. Both aerobic and anaerobic enrichment cultures were set

  18. Assessment of the Fusion Energy Sciences Program. Final Report

    International Nuclear Information System (INIS)

    2001-01-01

    An assessment of the Office of Fusion Energy Sciences (OFES) program with guidance for future program strategy. The overall objective of this study is to prepare an independent assessment of the scientific quality of the Office of Fusion Energy Sciences program at the Department of Energy. The Fusion Science Assessment Committee (FuSAC) has been appointed to conduct this study

  19. Characteristics of mixed bacterial cultures degarding EDTA, isolated from Czech sources

    Czech Academy of Sciences Publication Activity Database

    Ivanova, V.; Šafaříková, Miroslava; Vassileva, A.; Tonkova, A.

    2004-01-01

    Roč. 51, č. 3 (2004), s. 306-311 ISSN 0477-0250. [ Food Science, Techniques and Technologies 2004. Plovdiv, 27.10.2004-29.10.2004] R&D Projects: GA AV ČR IBS6087204 Institutional research plan: CEZ:AV0Z6087904 Keywords : EDTA * biodegradation Subject RIV: EE - Microbiology, Virology

  20. Immobilization of mixed bacterial cultures degrading EDTA and isolated from Bulgarian and Czech sources

    Czech Academy of Sciences Publication Activity Database

    Ivanova, V.; Tonkova, A.; Vassileva, A.; Šafaříková, Miroslava

    2004-01-01

    Roč. 51, č. 3 (2004), s. 312-317 ISSN 0477-0250. [Food Science, Techniques and Technologies 2004. Plovdiv, 27.10.2004-29.10.2004] R&D Projects: GA AV ČR IBS6087204 Institutional research plan: CEZ:AV0Z6087904 Keywords : EDTA * degradation * immobilization Subject RIV: EE - Microbiology, Virology

  1. Supporting Staff to Develop a Shared Understanding of Science Assessment

    Science.gov (United States)

    Sampey, Carol

    2018-01-01

    Assessment is not something that stands alone and teachers need support to develop their understanding of both assessment practices and the subject being assessed. Teachers at Shaw Primary School were fortunate to take part in the Teacher Assessment in Primary Science (TAPS) project and, in this article, the outlines how science and assessment can…

  2. Assessing clinical competency in the health sciences

    Science.gov (United States)

    Panzarella, Karen Joanne

    To test the success of integrated curricula in schools of health sciences, meaningful measurements of student performance are required to assess clinical competency. This research project analyzed a new performance assessment tool, the Integrated Standardized Patient Examination (ISPE), for assessing clinical competency: specifically, to assess Doctor of Physical Therapy (DPT) students' clinical competence as the ability to integrate basic science knowledge with clinical communication skills. Thirty-four DPT students performed two ISPE cases, one of a patient who sustained a stroke and the other a patient with a herniated lumbar disc. Cases were portrayed by standardized patients (SPs) in a simulated clinical setting. Each case was scored by an expert evaluator in the exam room and then by one investigator and the students themselves via videotape. The SPs scored each student on an overall encounter rubric. Written feedback was obtained from all participants in the study. Acceptable reliability was demonstrated via inter-rater agreement as well as inter-rater correlations on items that used a dichotomous scale, whereas the items requiring the use of the 4-point rubric were somewhat less reliable. For the entire scale both cases had a significant correlation between the Expert-Investigator pair of raters, for the CVA case r = .547, p performances on the ISPE with other independent estimates of students' competence. The unique integration questions of the ISPE were judged to have good content validity from experts and students, suggestive that integration, a most crucial element of clinical competence, while done in the mind of the student, can be practiced, learned and assessed.

  3. 21 CFR 172.135 - Disodium EDTA.

    Science.gov (United States)

    2010-04-01

    ..., other than black-eyed peas) 165 Promote color retention. Mayonnaise 75 Preservative. Ready-to-eat cereal... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Disodium EDTA. 172.135 Section 172.135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  4. Rate constants for the reaction of e-aq with EDTA and some metal EDTA-complexes

    International Nuclear Information System (INIS)

    Buitenhuis, R.; Bakker, C.M.N.; Stock, F.R.; Louwrier, P.W.F.

    1977-01-01

    The rate constants for the reaction e - aq + EDTA were measured as a function of the pH by the pulse-radiolysis technique. Between pH = 6and pH = 10 this rate constant can be represented by the equation k = 4.7 x 10 6 x (fraction of HEDTA 3- )+1.0 x 10 8 x (fraction H 2 EDTA 2 -)M -1 s -1 . Also the rate constants for reactions of e - aq with the following metal-EDTA complexes were measured: CuEDTA 2- , HgEDTA 2- , CoEDTA 2- , InEDTA - , NiEDTA 2- , GaEDTA - , MnEDTA 2- , ZnEDTA 2- , CdEDTA 2- , PbEDTA 2- . Ionic strength variation indicates that the reacting ions are not hydrolized to an appreciable amount at pH = 11.5. It is found that some of the products show light absorption in the region between 300 and 400 nm. (orig.) [de

  5. Integrated Science Assessment (ISA) for Sulfur Oxides ...

    Science.gov (United States)

    This draft document provides EPA’s evaluation and synthesis of the most policy-relevant science related to the health effects of sulfur oxides. When final, it will provide a critical part of the scientific foundation for EPA’s decision regarding the adequacy of the current primary (health-based) National Ambient Air Quality Standard (NAAQS) for sulfur dioxide. The references considered for inclusion in or cited in the external review draft ISA are available at https://hero.epa.gov/hero/sulfur-oxides. The intent of the ISA, according to the CAA, is to “accurately reflect the latest scientific knowledge expected from the presence of [a] pollutant in ambient air” (U.S. Code, 1970a, 1970b). It includes an assessment of scientific research from atmospheric sciences, exposure sciences, dosimetry, mode of action, animal and human toxicology, and epidemiology. Key information and judgments formerly found in the Air Quality Criteria Documents (AQCDs) for sulfur oxides (SOx) are included; Annexes provide additional details supporting the ISA. Together, the ISA and Annexes serve to update and revise the last SOx ISA which was published in 2008.

  6. Hurricane Sandy science plan: coastal impact assessments

    Science.gov (United States)

    Stronko, Jakob M.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

  7. Protective effect by EDTA in radiation inactivation of enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Kumakura, M; Kaetsu, I

    1985-11-05

    Protective effect by EDTA in radiation inactivation of enzymes such as glucoamylase, cellulase, and urease was studied. A remarkable protective effect by EDTA was observed and had a maximum at certain EDTA concentration. The protective effect was compared with other protective agents in the irradiation of urease, in which the protective ability of EDTA was greater than those of sulfhydryl compounds such as cysteine. (author).

  8. Toxicity Thresholds Based on EDTA Extractable Nickel and Barley Root Elongation in Chinese Soils

    Directory of Open Access Journals (Sweden)

    Guangyun Zhu

    2018-04-01

    Full Text Available The uncertainty in the risk assessment of trace metal elements in soils when total metal contents are used can be decreased by assessing their availability and/or extractability when the soils have a high background value or different sources of trace metal elements. In this study, the added water-soluble nickel (Ni toxicity to barley root elongation was studied in 17 representative Chinese soil samples with and without artificial rainwater leaching. The extractability of added Ni in soils was estimated by three sequential extractions with ethylenediaminetetraacetic acid (EDTA. The results showed that the effective concentration of EDTA extractable Ni (EC50, which caused 50% inhibition of barley root elongation, ranged from 46 to 1019 mg/kg in unleached soils and 24 to 1563 mg/kg in leached soils. Regression models for EDTA extractable Ni and total Ni added to soils against soil properties indicated that EDTA extractable Ni was significantly correlated with the total Ni added to soils and that pH was the most important control factor. Regression models for toxicity thresholds based on EDTA extractable Ni against soil properties showed that soil citrate dithionate extractable Fe was more important than soil pH in predicting Ni toxicity. These results can be used to accurately assess the risk of contaminated soils with high background values and/or different Ni sources.

  9. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2004-01-01

    The contamination of many DOE sites by Pu presents a long-term problem because of its long half-life (240,000 yrs) and the low drinking water standard ( -12 M). EDTA was co-disposed with radionuclides (e.g., Pu, 60 Co), formed strong complexes, and enhanced radionuclide transport at several DOE sites. Biodegradation of EDTA should decrease Pu mobility. One objective of this project was to determine the biodegradation of EDTA in the presence of PuEDTA complexes. The aqueous system investigated at pH 7 (10 -4 M EDTA and 10 -6 M Pu) contained predominantly Pu(OH) 2 EDTA 2- . The EDTA was degraded at a faster rate in the presence of Pu. As the total concentration of both EDTA and PuEDTA decreased (i.e., 10 -5 M EDTA and 10 -7 M PuEDTA), the presence of Pu decreased the biodegradation rate of the EDTA. It is currently unclear why the concentration of Pu directly affects the increase/decrease in rate of EDTA biodegradation. The soluble Pu concentration decreased, in agreement with thermodynamic predictions, as the EDTA was biodegraded, indicating that biodegradation of EDTA will decrease Pu mobility when the Pu is initially present as Pu(IV)EDTA. A second objective was to investigate how the presence of competing metals, commonly encountered in geologic media, will influence the speciation and biodegradation of Pu(IV)-EDTA. Studies on the solubilities of Fe(OH) 3 (s) and of Fe(OH) 3 (s) plus PuO 2 (am) in the presence of EDTA and as a function of pH showed that Fe(III) out competes the Pu(IV) for the EDTA complex, thereby showing that Pu(IV) will not form stable complexes with EDTA for enhanced transport of Pu in Fe(III) dominated subsurface systems. A third objective is to investigate the genes and enzymes involved in EDTA biodegradation. BNC1 can use EDTA and another synthetic chelating agent nitrilotriacetate (NTA) as sole carbon and nitrogen sources. The same catabolic enzymes are responsible for both EDTA and NTA degradation except that additional enzymes are

  10. 21 CFR 73.2120 - Disodium EDTA-copper.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Disodium EDTA-copper. 73.2120 Section 73.2120 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2120 Disodium EDTA-copper. (a) Identity. The color additive disodium EDTA-copper is disodium [[N,N′- 1,2- ethanediylbis[N - (carboxymethyl) glycinato...

  11. 77 FR 26292 - Risk Evaluation and Mitigation Strategy Assessments: Social Science Methodologies to Assess Goals...

    Science.gov (United States)

    2012-05-03

    ...] Risk Evaluation and Mitigation Strategy Assessments: Social Science Methodologies to Assess Goals... announcing a public workshop entitled ``Risk Evaluation and Mitigation Strategy Assessments: Social Science... constructive dialogue and information-sharing among regulators, researchers, the pharmaceutical industry...

  12. Comparison of EDTA and EDDS as potential soil amendments for enhanced phytoextraction of heavy metals.

    Science.gov (United States)

    Meers, E; Ruttens, A; Hopgood, M J; Samson, D; Tack, F M G

    2005-02-01

    Phytoextraction has been proposed as an alternative remediation technology for soils polluted with heavy metals or radionuclides, but is generally conceived as too slow working. Enhancing the accumulation of trace pollutants in harvestable plant tissues is a prerequisite for the technology to be practically applicable. The chelating aminopolycarboxylic acid, ethylene diamine tetraacetate (EDTA), has been found to enhance shoot accumulation of heavy metals. However, the use of EDTA in phytoextraction may not be suitable due to its high environmental persistence, which may lead to groundwater contamination. This paper aims to assess whether ethylene diamine disuccinate (EDDS), a biodegradable chelator, can be used for enhanced phytoextraction purposes. A laboratory experiment was conducted to examine mobilisation of Cd, Cu, Cr, Ni, Pb and Zn into the soil solution upon application of EDTA or EDDS. The longevity of the induced mobilisation was monitored for a period of 40 days after application. Estimated effect half lives ranged between 3.8 and 7.5 days for EDDS, depending on the applied dose. The minimum observed effect half life of EDTA was 36 days, while for the highest applied dose no decrease was observed throughout the 40 day period of the mobilisation experiment. Performance of EDTA and EDDS for phytoextraction was evaluated by application to Helianthus annuus. Two other potential chelators, known for their biodegradability in comparison to EDTA, were tested in the plant experiment: nitrilo acetic acid (NTA) and citric acid. Uptake of heavy metals was higher in EDDS-treated pots than in EDTA-treated pots. The effects were still considered insufficiently high to consider efficient remediation. This may be partly due to the choice of timing for application of the soil amendment. Fixing the time of application at an earlier point before harvest may yield better results. NTA and citric acid induced no significant effects on heavy metal uptake.

  13. Teaching and Assessing the Nature of Science

    Science.gov (United States)

    Clough, Michael P.

    2011-01-01

    Understanding the nature of science (NOS)--what science is and how it works, the assumptions that underlie scientific knowledge, how scientists function as a social group, and how society impacts and reacts to science--is prominent in science education reform documents (Rutherford and Ahlgren 1990; AAAS 1993; McComas and Olson 1998; NRC 1996; AAAS…

  14. Assessing Prinary School; Second Cycle Social Science Textbooks ...

    African Journals Online (AJOL)

    Assessing Prinary School; Second Cycle Social Science Textbooks in ... second cycle primary level social science textbooks vis-à-vis the principles of multiculturalism. ... Biases were disclosed in gender, economic and occupational roles.

  15. The study of operating variables in soil washing with EDTA

    International Nuclear Information System (INIS)

    Zou Zeli; Qiu Rongliang; Zhang Weihua; Dong Hanying; Zhao Zhihao; Zhang Tao; Wei Xiange; Cai Xinde

    2009-01-01

    This study discusses the operating variables for removal of metals from soils using EDTA, including the type of EDTA, reaction time, solution pH, dose, temperature, agitation, ultrasound and number of extractions. For As, Cd, Cu, Pb and Zn, the removal efficiency order was: H 4 -EDTA > Na 2 EDTA > (NH 4 ) 2 EDTA. At low EDTA concentrations the removal increased progressively with increasing dose while above 0.4 mmol/g only small increases in extraction efficiency were observed. EDTA induced a two-step process including a rapid desorption within the first hour, and a gradual release in the following hours. The extraction efficiency of metals decreased with increasing pH in the range of 2-10. Consecutive extractions using low concentrations were more effective than a single extraction with concentrated EDTA if the same dose of EDTA was used. - Consecutive extractions using low concentrations are more effective than a single extraction with concentrated EDTA if the same dose of EDTA is used

  16. Multifunctional adhesive polymers: Preactivated thiolated chitosan-EDTA conjugates.

    Science.gov (United States)

    Netsomboon, Kesinee; Suchaoin, Wongsakorn; Laffleur, Flavia; Prüfert, Felix; Bernkop-Schnürch, Andreas

    2017-02-01

    The aim of this study was to synthesis preactivated thiolated chitosan-EDTA (Ch-EDTA-cys-2MNA) conjugates exhibiting in particular high mucoadhesive, cohesive and chelating properties. Thiol groups were coupled with chitosan by carbodiimide reaction and further preactivated by attachment with 2-mercaptonicotinic acid (2MNA) via disulfide bond formation. Determinations of primary amino and sulfhydryl groups were performed by TNBS and Ellman's tests, respectively. Cytotoxicity was screened by resazurin assay in Caco-2 cells. Mucoadhesive properties and bivalent cation binding capacity with Mg 2+ and Ca 2+ in comparison to chitosan-EDTA (Ch-EDTA) and thiolated Ch-EDTA (Ch-EDTA-cys) were evaluated. Determination of 2MNA and total sulfhydryl groups indicated that 80% of thiol groups were preactivated. The results from cytotoxicity studies demonstrated that Ch-EDTA-cys and Ch-EDTA-cys-2MNA were not toxic to the cells at the polymer test concentration of 0.25% (w/v) while cell viability decreased by increasing the concentration of Ch-EDTA. Although EDTA molecule was modified by thiolation and preactivation, approximately 50% of chelating properties of the conjugates were maintained compared to Ch-EDTA. Ch-EDTA-cys-2MNA adhered on freshly excised porcine intestinal mucosa up to 6h while Ch-EDTA adhered for just 1h. According to the combination of mucoadhesive and chelating properties of the conjugates synthesized in this study, Ch-EDTA-cys-2MNA might be useful for various mucosal drug delivery systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Intestinal permeability to [51Cr]EDTA in children with Crohn's disease and celiac disease

    International Nuclear Information System (INIS)

    Turck, D.; Ythier, H.; Maquet, E.; Deveaux, M.; Marchandise, X.; Farriaux, J.P.; Fontaine, G.

    1987-01-01

    [ 51 Cr]EDTA was used as a probe molecule to assess intestinal permeability in 7 healthy control adults, 11 control children, 17 children with Crohn's disease, and 6 children with untreated celiac disease. After subjects fasted overnight, 75 kBq/kg (= 2 microCi/kg) 51 Cr-labeled EDTA was given by mouth; 24-h urinary excretion of [ 51 Cr]EDTA was measured and expressed as a percentage of the total oral dose. Mean and SD were as follows: control adults 1.47 +/- 0.62, control children 1.59 +/- 0.55, and patients with Crohn's disease or celiac disease 5.35 +/- 1.94. The difference between control children and patients was statistically significant (p less than 0.001). These results show that intestinal permeability to [ 51 Cr]EDTA is increased among children with active or inactive Crohn's disease affecting small bowel only or small bowel and colon, and with untreated celiac disease. The [ 51 Cr]EDTA permeability test could facilitate the decision to perform more extensive investigations in children suspected of small bowel disease who have atypical or poor clinical and biological symptomatology

  18. Advanced Science for Kids: Multicultural Assessment and Programming.

    Science.gov (United States)

    Bettac, Teresa; Huckabee, Colleen; Musser, Louise; Patton, Paulette; Yates, Joyce

    1997-01-01

    Describes Advanced Science for Kids (ASK), a multicultural approach to assessment and programming for a middle school advanced science program. ASK is designed to provide alternative approaches to identification and assessment, facilitate authentic instruction and assessment, and provide minority students with academic and social support as they…

  19. 'Scan GFR' as an alternative to 51Cr-EDTA clearance

    International Nuclear Information System (INIS)

    Osman, E.A.; Clarke, M.B.; Barrett, J.J.; Parsons, V.; Dulwich Hospital, London

    1989-01-01

    In this report 39 patients had their GFR assessed by 51 Cr-EDTA in a single shot-multiple sampling technique and also by measuring the quantitative renal uptake of 99m Tc-DTPA during a standard renal imaging test. The results showed a correlation coefficient of 0.96 between the two techniques. By using linear regression analysis the GFR was derived from the % renal uptake of DTPA in a further series of 24 patients in whom the 51 Cr-EDTA method was also employed. The two methods were compared and showed a correlation coefficient of 0.94 with a mean GFR difference of 7 ± 4.5 ml/min over a 51 Cr-EDTA range of 38-150 ml/min. (orig.) [de

  20. The use of EDTA and DTPA for accelerating the removal of deposited transuranic elements from humans

    CERN Document Server

    Spoor, N L

    1977-01-01

    EDTA and DTPA have been prominent among the chelating agents used to increase the rate of excretion of certain deposited heavy metals from the human body. Since 1959, DTPA, administered either by intravenous injection or by aerosol inhalation, has been widely used to treat workers contaminated by plutonium or a higher actinide. In this report, an attempt is made to assess the toxicities of EDTA and DTPA and to evaluate the effectiveness and safety of DTPA as a drug for removing deposited transuranic elements.

  1. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Xun, Luying; Bolton, Jr. Harvey

    2002-01-01

    This project, by Dr. Xun, supports work at PNNL (Bolton) regarding plutonium mobility in the subsurface. Ethylenediaminetetraacetate (EDTA) is a chelating agent that can increase the mobility of radionuclides and heavy metals in groundwater. Biodegradation of EDTA can decrease the enhanced mobility. The overall objective is to understand how microbial degradation affects Plutonium-EDTA transport in the environment and the specific objective of this component is to understand how microorganisms degrade EDTA. A chelating degrading bacterium BNC1 can use EDTA and nitrilotriacetate (NTA) as sole carbon and nitrogen sources. A gene cluster responsible for both EDTA and NTA degradation has been cloned and characterized (1,2). The same enzymes are used to degrade both compounds except that additional enzymes are required for EDTA degradation. Since the enzymes are located inside cells, EDTA and NTA must be transported into cells for degradation. For the first funding year, we have focused on how EDTA and NTA are transported into BNC1 cells. The EDTA-degrading gene cluster also contains genes encoding a hypothetical ABC-type transporter. We first demonstrated that the transporter genes and EDTA monooxygenase gene (emoA) were co-transcribed by RT-PCR, suggesting that the genes are involved in EDTA transport. We then characterized one of the gene product EppA. Using recombinant EppA purified from Escherichia coli, we have shown that EppA binds several metal:EDTA complexes by fluorescence techniques. In addition, EppA is shown to bind Mg:NTA, Ca:NTA and Fe(III):NTA but not free NTA

  2. Needs Assessment Study in Science Education: Sample of Turkey

    OpenAIRE

    Z. Ozdilek; M. Ozkan

    2008-01-01

    A needs assessment process was conducted to determine the difficulties and requirements of a science unit as an example how needs assessment process can be used in science education in Turkey. A 40-item teacher questionnaire containing four dimensions related to a chemistry unit named “Travel to the Inner Structure of Matter” as presented in the current curriculum materials was administered. The questionnaire was completed by 130 elementary school science teachers in order to get their views ...

  3. 78 FR 38318 - Integrated Science Assessment for Lead

    Science.gov (United States)

    2013-06-26

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9827-4] Integrated Science Assessment for Lead AGENCY... availability of a final document titled, ``Integrated Science Assessment for Lead'' (EPA/600/R-10/075F). The... lead (Pb). DATES: The document will be available on or around June 26, 2013. ADDRESSES: The...

  4. EDTA chelation therapy alone and in combination with oral high-dose multivitamins and minerals for coronary disease: The factorial group results of the Trial to Assess Chelation Therapy.

    Science.gov (United States)

    Lamas, Gervasio A; Boineau, Robin; Goertz, Christine; Mark, Daniel B; Rosenberg, Yves; Stylianou, Mario; Rozema, Theodore; Nahin, Richard L; Terry Chappell, L; Lindblad, Lauren; Lewis, Eldrin F; Drisko, Jeanne; Lee, Kerry L

    2014-07-01

    Disodium ethylenediaminetetraacetic acid (EDTA) reduced adverse cardiac outcomes in a factorial trial also testing oral vitamins. This report describes the intent-to-treat comparison of the 4 factorial groups overall and in patients with diabetes. This was a double-blind, placebo-controlled, 2 × 2 factorial multicenter randomized trial of 1,708 post-myocardial infarction (MI) patients ≥50 years of age and with creatinine ≤2.0 mg/dL randomized to receive 40 EDTA chelation or placebo infusions plus 6 caplets daily of a 28-component multivitamin-multimineral mixture or placebo. The primary end point was a composite of total mortality, MI, stroke, coronary revascularization, or hospitalization for angina. Median age was 65 years, 18% were female, 94% were Caucasian, 37% were diabetic, 83% had prior coronary revascularization, and 73% were on statins. Five-year Kaplan-Meier estimates for the primary end point was 31.9% in the chelation + high-dose vitamin group, 33.7% in the chelation + placebo vitamin group, 36.6% in the placebo infusion + active vitamin group, and 40.2% in the placebo infusions + placebo vitamin group. The reduction in primary end point by double active treatment compared with double placebo was significant (hazard ratio 0.74, 95% CI 0.57-0.95, P = .016). In patients with diabetes, the primary end point reduction of double active compared with double placebo was more pronounced (hazard ratio 0.49, 95% CI 0.33-0.75, P < .001). In stable post-MI patients on evidence-based medical therapy, the combination of oral high-dose vitamins and chelation therapy compared with double placebo reduced clinically important cardiovascular events to an extent that was both statistically significant and of potential clinical relevance. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

  5. The Workshop Program on Authentic Assessment for Science Teachers

    Science.gov (United States)

    Rustaman, N. Y.; Rusdiana, D.; Efendi, R.; Liliawati, W.

    2017-02-01

    A study on implementing authentic assessment program through workshop was conducted to investigate the improvement of the competence of science teachers in designing performance assessment in real life situation at school level context. A number of junior high school science teachers and students as participants were involved in this study. Data was collected through questionnaire, observation sheets, and pre-and post-test during 4 day workshop. This workshop had facilitated them direct experience with seventh grade junior high school students during try out. Science teachers worked in group of four and communicated each other by think-pair share in cooperative learning approach. Research findings show that generally the science teachers’ involvement and their competence in authentic assessment improved. Their knowledge about the nature of assessment in relation to the nature of science and its instruction was improved, but still have problem in integrating their design performance assessment to be implemented in their lesson plan. The 7th grade students enjoyed participating in the science activities, and performed well the scientific processes planned by group of science teachers. The response of science teachers towards the workshop was positive. They could design the task and rubrics for science activities, and revised them after the implementation towards the students. By participating in this workshop they have direct experience in designing and trying out their ability within their professional community in real situation towards their real students in junior high school.

  6. Taking Stock: Implications of a New Vision of Science Learning for State Science Assessment

    Science.gov (United States)

    Wertheim, Jill

    2016-01-01

    This article presents the author's response to the article "Taking Stock: Existing Resources for Assessing a New Vision of Science Learning" by Alonzo and Ke (this issue), which identifies numerous challenges that the Next Generation Science Standards (NGSS) pose for large-scale assessment. Jill Werthem comments that among those…

  7. Health Technology Assessment - science or art?

    Science.gov (United States)

    Hofmann, Bjørn

    2013-01-01

    The founding disciplines of HTA are clearly scientific, and have been firmly based among the natural sciences. However, common definitions of HTA indicate that HTA is something more than the "pure application of science". This article investigates whether this "something" also makes HTA an art. The question of whether HTA is a science or an art is pursued in two specific and historically rich directions. The first is whether HTA is an art in the same way that medicine is described as an art. It has been argued extensively that medicine is based on two different and partly incompatible cultures, i.e., the natural sciences and humanities. Medicine is based on disciplines within the natural sciences, while its value judgments have been placed in the humanities camp. This dichotomy is present in HTA as well, and the first part of the investigation illustrates how HTA is an art in terms of its inherent and constitutive value-judgments. The second part of the science/art-scrutiny leads us to the ancient (Hippocratic) concept of art, téchne, where we find an etymological and a conceptual link between HTA and art. It demonstrates HTA is not an arbitrary process, even though it involves value judgments and relates complex decision making processes. As an art (téchne) HTA has a specific subject matter, requires inquiry and mastery of general rational principles, and is oriented to a specific end. In conclusion, the science-or-art-question makes sense in two specific perspectives, illustrating that HTA is a science based art. This has implications for the practice of HTA, for its education, and for the status of its results.

  8. Assessing a Science Graduate School Recruitment Symposium.

    Science.gov (United States)

    González-Espada, Wilson; Díaz-Muñoz, Greetchen; Feliú-Mójer, Mónica; Flores-Otero, Jacqueline; Fortis-Santiago, Yaihara; Guerrero-Medina, Giovanna; López-Casillas, Marcos; Colón-Ramos, Daniel A; Fernández-Repollet, Emma

    2015-12-01

    Ciencia Puerto Rico, a non-profit organization dedicated to promoting science, research and scientific education among Latinos, organized an educational symposium to provide college science majors the tools, opportunities and advice to pursue graduate degrees and succeed in the STEM disciplines. In this article we share our experiences and lessons learned, for others interested in developing large-scale events to recruit underrepresented minorities to STEM and in evaluating the effectiveness of these efforts.

  9. Outer Sphere Adsorption of Pb(II)EDTA on Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Bargar, John R

    1999-07-16

    FTIR and EXAFS spectroscopic measurements were performed on Pb(II)EDTA adsorbed on goethite as functions of pH (4-6), Pb(II)EDTA concentration (0.11 {micro}M - 72 {micro}M), and ionic strength (16 {micro}M - 0.5M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both amine groups bonded to Pb(II). No evidence was observed for inner-sphere Pb(II)-goethite bonding at Pb:EDTA = 1:1. Hence, the adsorbed complexes should have composition Pb(II)EDTA{sup 2{minus}}. Since substantial uptake of PbEDTA(II){sup 2{minus}} occurred in the samples, we infer that Pb(II)EDTA{sup 2{minus}} adsorbed as outer-sphere complexes and/or as complexes that lose part of their solvation shells and hydrogen bond directly to goethite surface sites. We propose the term ''hydration-sphere'' for the latter type of complexes because they should occupy space in the primary hydration spheres of goethite surface functional groups, and to distinguish this mode of sorption from common structural definitions of inner- and outer-sphere complexes. The similarity of Pb(II) uptake isotherms to those of other divalent metal ions complexed by EDTA suggests that they too adsorb by these mechanisms. The lack of evidence for inner-sphere EDTA-Fe(III) bonding suggests that previously proposed metal-ligand - promoted dissolution mechanisms should be modified, specifically to account for the presence of outer-sphere precursor species.

  10. Protective effect of EDTA preadministration on renal ischemia

    Directory of Open Access Journals (Sweden)

    Belloni Daniela

    2006-03-01

    Full Text Available Abstract Background Chelation therapy with sodium edetate (EDTA improved renal function and slowed the progression of renal insufficiency in patients subjected to lead intoxication. This study was performed to identify the underlying mechanism of the ability of EDTA treatment to protect kidneys from damage. Methods The effects of EDTA administration were studied in a rat model of acute renal failure induced by 60 minutes ischemia followed or not by 60 minutes reperfusion. Renal ischemic damage was evaluated by histological studies and by functional studies, namely serum creatinine and blood urea nitrogen levels. Treatment with EDTA was performed 30 minutes before the induction of ischemia. Polymorphonuclear cell (PMN adhesion capability, plasmatic nitric oxide (NO levels and endothelial NO synthase (eNOS renal expression were studied as well as the EDTA protection from the TNFα-induced vascular leakage in the kidneys. Data was compared by two-way analysis of variance followed by a post hoc test. Results EDTA administration resulted in the preservation of both functional and histological parameters of rat kidneys. PMN obtained from peripheral blood of EDTA-treated ischemized rats, displayed a significant reduction in the expression of the adhesion molecule Mac-1 with respect to controls. NO was significantly increased by EDTA administration and eNOS expression was higher and more diffuse in kidneys of rats treated with EDTA than in the controls. Finally, EDTA administration was able to prevent in vivo the TNFα-induced vascular leakage in the kidneys. Conclusion This data provides evidence that EDTA treatment is able to protect rat kidneys from ischemic damage possibly through the stimulation of NO production.

  11. Health Technology Assessmentscience or art?

    Science.gov (United States)

    Hofmann, Bjørn

    2013-01-01

    The founding disciplines of HTA are clearly scientific, and have been firmly based among the natural sciences. However, common definitions of HTA indicate that HTA is something more than the “pure application of science”. This article investigates whether this “something” also makes HTA an art. The question of whether HTA is a science or an art is pursued in two specific and historically rich directions. The first is whether HTA is an art in the same way that medicine is described as an art. It has been argued extensively that medicine is based on two different and partly incompatible cultures, i.e., the natural sciences and humanities. Medicine is based on disciplines within the natural sciences, while its value judgments have been placed in the humanities camp. This dichotomy is present in HTA as well, and the first part of the investigation illustrates how HTA is an art in terms of its inherent and constitutive value-judgments. The second part of the science/art-scrutiny leads us to the ancient (Hippocratic) concept of art, téchne, where we find an etymological and a conceptual link between HTA and art. It demonstrates HTA is not an arbitrary process, even though it involves value judgments and relates complex decision making processes. As an art (téchne) HTA has a specific subject matter, requires inquiry and mastery of general rational principles, and is oriented to a specific end. In conclusion, the science-or-art-question makes sense in two specific perspectives, illustrating that HTA is a science based art. This has implications for the practice of HTA, for its education, and for the status of its results. PMID:23935761

  12. Contextual assessment in science education: Background, issues, and policy

    Science.gov (United States)

    Klassen, Stephen

    2006-09-01

    Contemporary assessment practices in science education have undergone significant changes in recent decades. The basis for these changes and the resulting new assessment practices are the subject of this two-part paper. Part 1 considers the basis of assessment that, more than 25 years ago, was driven by the assumptions of decomposability and decontextualization of knowledge, resulting in a low-inference testing system, often described as traditional. This assessment model was replaced not on account of direct criticism, but rather on account of a larger revolution - the change from behavioral to cognitive psychology, developments in the philosophy of science, and the rise of constructivism. Most notably, the study of the active cognitive processes of the individual resulted in a major emphasis on context in learning and assessment. These changes gave rise to the development of various contextual assessment methodologies in science education, for example, concept mapping assessment, performance assessment, and portfolio assessment. In Part 2, the literature relating to the assessment methods identified in Part 1 is reviewed, revealing that there is not much research that supports their validity and reliability. However, encouraging new work on selected-response tests is forming the basis for reconsideration of past criticisms of this technique. Despite the major developments in contextual assessment methodologies in science education, two important questions remain unanswered, namely, whether grades can be considered as genuine numeric quantities and whether the individual student is the appropriate unit of assessment in public accountability. Given these issues and the requirement for science assessment to satisfy the goals of the individual, the classroom, and the society, tentative recommendations are put forward addressing these parallel needs in the assessment of science learning.

  13. Science and judgment in risk assessment

    National Research Council Canada - National Science Library

    National Research Council (U.S.). Committee on Risk Assessment of Hazardous Air Pollutants

    1994-01-01

    ... on Environmental Studies and Toxicology Commission on Life Sciences National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1994 i Copyrightoriginal retained, the be not from cannot book, paper original however, for version formatting, authoritative the typesetting-specific created from the as publication files other XML and from this of recompo...

  14. Evaluation and Assessment in Early Social Science

    Science.gov (United States)

    Hus, Vlasta; Matjašic, Jasmina

    2017-01-01

    Authenticity is an important element in the newer models of teaching, evaluation and assessment. Due to the fact that it is quite unclear how authentic evaluation and assessment should be implemented into practice, teachers still cling too much to traditional forms of knowledge evaluation and assessment. First, some basic theoretical facts on…

  15. EDTA modified glassy carbon electrode: Preparation and characterization

    International Nuclear Information System (INIS)

    Ustuendag, Zafer; Solak, Ali Osman

    2009-01-01

    EDTA-phenoxyamide modified glassy carbon electrode (EDTA-GC) was prepared at a glassy carbon electrode by surface synthesis. In the first step, nitrophenyl was grafted to the glassy carbon (GC) surface via the electrochemical reduction of its tetraflouroborate diazonium salt. In the second step, nitrophenyl-modified electrode (NP-GC) was subjected to the cathodic potential scan to reduce the nitro to amine group. p-Aminophenyl modified glassy carbon electrode (AP-GC) was dipped into a EDTA solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide (EDC) as an activating agent. Thus formed ((2-anilino-2-oxoethyl){2-[bis(carboxymethyl)amino]-ethyl}amino)acetic acid modified GC electrode was denoted as EDTA-GC and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ellipsometry and X-ray photoelectron spectroscopy (XPS). Complexation of the EDTA-GC surface with Pb 2+ ions was investigated if this electrode could be used as a metal sensor.

  16. Coulometric titration of niobium in EDTA complexing solution

    International Nuclear Information System (INIS)

    Pannu, S.S.

    1976-01-01

    Constant current coulometry of Nb in EDTA was studied employing both potentiometric and amperometric end-point techniques. The titrations were based on the oxidation of Nb(IV)-EDTA with electrogenerated Fe(III) at a graphite anode. The rate of disproportionation of Nb(IV)-EDTA was found to be slow enough not to effect the accuracy sought for the titration. The coulometric titration of Nb in EDTA was found to be more accurate than in 1F sulfuric acid. The mean error in the titrations of 4.76 to 19.65 of Nb in a volume of about 100 ml of 0.02 to 0.04F EDTA was 0.13%. It was found that Ta may be tolerated to a ratio of 1:4, Ta:Nb, in a solution containing 13 mg of Nb. (author)

  17. Growth and characterization of EDTA assisted CBD-CdS

    Energy Technology Data Exchange (ETDEWEB)

    Kumarage, W.G.C.; Wijesundera, R. P.; Seneviratne, V. A.; Jayalath, C. P.; Varga, Tamas; Nandasiri, Manjula I.; Dassanayake, B. S.

    2017-10-01

    Chemical bath deposition of CdS (CBD-CdS) thin films with the assistance of a cationic surfactant, ethylenediamine tetraacetic acid (EDTA), is reported in this work. Also the EDTA treated CdS thin films are compared with that of conventional CBD-CdS. Fabricated thin, compact, uniform and adherent EDTA treated CdS films show enhanced effective surface area and roughness compared to conventional CBD-CdS. The grazing incidence x-ray diffraction analysis shows all the fabricated CdS films are hexagonally crystallized. EDTA-treated CdS films show excellent photo activity compared to conventional CBDCdS. The flat band potential (Vfb) value was found to be tunable with EDTA concentration.

  18. Dissolution of root canal sealers in EDTA and NaOCl solutions.

    Science.gov (United States)

    Keleş, Ali; Köseoğlu, Mustafa

    2009-01-01

    Solutions of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) have been used as canal irrigants in endodontic treatment. The authors conducted a study to compare the ability of these solutions to dissolve sealers. The authors assessed the solubility of six sealers-calcium hydroxide, polyketone, zinc oxide-eugenol, silicone and two epoxy resins-in EDTA and two concentrations of NaOCl (2.5 percent and 5.0 percent). They immersed standardized samples (n = 5) of each sealer for two minutes and 10 minutes. They obtained the mean values of sealer dissolution in solutions by calculating the difference between the original preimmersion and postimmersion weights to determine the amount of sealer removed. They compared the values via factorial analysis of variance. They analyzed differences between the six sealers with respect to their solubility in EDTA or NaOCl solutions at two minutes and 10 minutes by using a one-way analysis of variance (P Polyketone and calcium hydroxide-based sealers were the most soluble sealers (P < .05). The results of this study indicate that during nonsurgical endodontic re-treatment, EDTA and NaOCl solutions used for removing smear layer aided in the retreatment by dissolving some root canal sealers.

  19. Interim research assessment 2003-2005 - Computer Science

    NARCIS (Netherlands)

    Mouthaan, A.J.; Hartel, Pieter H.

    This report primarily serves as a source of information for the 2007 Interim Research Assessment Committee for Computer Science at the three technical universities in the Netherlands. The report also provides information for others interested in our research activities.

  20. Effects of calcium binding and of EDTA and CaEDTA on the clotting of bovine fibrinogen by thrombin.

    Science.gov (United States)

    Perizzolo, K E; Sullivan, S; Waugh, D F

    1985-03-01

    Studies were carried out at pH 7.0 and gamma/2 0.15 before addition of CaCl2 or EDTA. Clotting time, tau, at 3.03 microM fibrinogen and 0.91 u/ml thrombin was determined for equilibrium systems. With added Ca2+, tau decreases, from tau 0 at 0 added Ca2+ (mean, 29.7 +/- 3 s), by approximately 3 s at 5 mM added Ca2+. With added EDTA, tau increases sigmoidally from tau 0 at 0 EDTA to a maximum (mean tau m = 142 +/- 23 s) at approximately 200 microM EDTA. tau then decreases slightly to a minimum at approximately 1.3 mM and finally increases to infinity at approximately 10 mM EDTA. Between 0 and 1.3 mM EDTA, effects on clotting time are completely reversed by adding Ca2+ and, after equilibration at 400 microM EDTA, tau is independent of EDTA concentration. Thus, up to 400 microM EDTA, effects on clotting time are attributed to decreasing fibrinogen bound Ca2+. Between 5 mM Ca2+ and 200 microM EDTA it is assumed that an equilibrium distribution of fibrinogen species having 3, 2, 1, or 0 bound calcium ions is established and that a clotting time is determined by the sum of products of species fractional abundance and pure species clotting time. Analysis indicates that pure species clotting times increase proportionately with decreasing Ca2+ binding, binding sites are nearly independent, and the microscopic association constant for the first bound Ca2+ is approximately 4.9 X 10(6) M-1. Effects of adding Ca2+ at times t1 after thrombin addition to systems initially equilibrated at 200 microM EDTA were determined. Analysis of the relation between tau and t1 indicates that as Ca2+ binding decreases, rate constants for release of B peptides decrease less than those for release of A peptides. As EDTA concentration is increased above 1.3 mM, inhibitory effects of EDTA and CaEDTA progressively increase.

  1. Assessment of the Forensic Sciences Profession: A Legal Study Concerning the Forensic Sciences Personnel. Volume III.

    Science.gov (United States)

    Schroeder, Oliver, Jr.

    The place and function of forensic sciences personnel in American criminal law and court procedure, and the criteria used by criminal trial judges and lawyers to assess the value of forensic sciences personnel were investigated. Federal, state, Virgin Island, and Puerto Rican laws were examined, and a search of the medical and legal literature…

  2. Student Explanations of Their Science Teachers' Assessments, Grading Practices and How They Learn Science

    Science.gov (United States)

    del Carmen Gomez, María

    2018-01-01

    The current paper draws on data generated through group interviews with students who were involved in a larger ethnographic research project performed in three science classrooms. The purpose of the study from which this data was generated, was to understand science teachers' assessment practices in an upper-secondary school in Sweden. During…

  3. Relationships Between the Way Students Are Assessed in Science Classrooms and Science Achievement Across Canada

    Science.gov (United States)

    Chu, Man-Wai; Fung, Karen

    2018-04-01

    Canadian students experience many different assessments throughout their schooling (O'Connor 2011). There are many benefits to using a variety of assessment types, item formats, and science-based performance tasks in the classroom to measure the many dimensions of science education. Although using a variety of assessments is beneficial, it is unclear exactly what types, format, and tasks are used in Canadian science classrooms. Additionally, since assessments are often administered to help improve student learning, this study identified assessments that may improve student learning as measured using achievement scores on a standardized test. Secondary analyses of the students' and teachers' responses to the questionnaire items asked in the Pan-Canadian Assessment Program were performed. The results of the hierarchical linear modeling analyses indicated that both students and teachers identified teacher-developed classroom tests or quizzes as the most common types of assessments used. Although this ranking was similar across the country, statistically significant differences in terms of the assessments that are used in science classrooms among the provinces were also identified. The investigation of which assessment best predicted student achievement scores indicated that minds-on science performance-based tasks significantly explained 4.21% of the variance in student scores. However, mixed results were observed between the student and teacher responses towards tasks that required students to choose their own investigation and design their own experience or investigation. Additionally, teachers that indicated that they conducted more demonstrations of an experiment or investigation resulted in students with lower scores.

  4. Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.

    Directory of Open Access Journals (Sweden)

    Lejla Imamovic

    Full Text Available BACKGROUND: The bacteriophage life cycle has an important role in Shiga toxin (Stx expression. The induction of Shiga toxin-encoding phages (Stx phages increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cell. Previous studies suggested that prophage induction might also occur in the absence of SOS response, independently of RecA. METHODOLOGY/PRINCIPAL FINDINGS: The influence of EDTA on RecA-independent Stx2 phage induction was assessed, in laboratory lysogens and in EHEC strains carrying Stx2 phages in their genome, by Real-Time PCR. RecA-independent mechanisms described for phage λ induction (RcsA and DsrA were not involved in Stx2 phage induction. In addition, mutations in the pathway for the stress response of the bacterial envelope to EDTA did not contribute to Stx2 phage induction. The effect of EDTA on Stx phage induction is due to its chelating properties, which was also confirmed by the use of citrate, another chelating agent. Our results indicate that EDTA affects Stx2 phage induction by disruption of the bacterial outer membrane due to chelation of Mg(2+. In all the conditions evaluated, the pH value had a decisive role in Stx2 phage induction. CONCLUSIONS/SIGNIFICANCE: Chelating agents, such as EDTA and citrate, induce Stx phages, which raises concerns due to their frequent use in food and pharmaceutical products. This study contributes to our understanding of the phenomenon of induction and release of Stx phages as an important factor in the pathogenicity of Shiga toxin-producing Escherichia coli (STEC and in the emergence of new pathogenic strains.

  5. Science and judgment in risk assessment

    National Research Council Canada - National Science Library

    National Research Council (U.S.). Committee on Risk Assessment of Hazardous Air Pollutants

    .... This comprehensive and readable book explores how the U.S. Environmental Protection Agency (EPA) can improve its risk assessment practices, with a focus on implementation of the 1990 Clean Air Act Amendments...

  6. Assessing Motivations and Use of Online Citizen Science Astronomy Projects

    Science.gov (United States)

    Nona Bakerman, Maya; Buxner, Sanlyn; Bracey, Georgia; Gugliucci, Nicole

    2018-01-01

    The exponential proliferation of astronomy data has resulted in the need to develop new ways to analyze data. Recent efforts to engage the public in the discussion of the importance of science has led to projects that are aimed at letting them have hands-on experiences. Citizen science in astronomy, which has followed the model of citizen science in other scientific fields, has increased in the number and type of projects in the last few years and poses captivating ways to engage the public in science.The primary feature of this study was citizen science users’ motivations and activities related to engaging in astronomy citizen science projects. We report on participants’ interview responses related to their motivations, length and frequency of engagement, and reasons for leaving the project. From May to October 2014, 32 adults were interviewed to assess their motivations and experiences with citizen science. In particular, we looked at if and how motivations have changed for those who have engaged in the projects in order to develop support for and understandparticipants of citizen science. The predominant reasons participants took part in citizen science were: interest, helping, learning or teaching, and being part of science. Everyone interviewed demonstrated an intrinsic motivation to do citizen science projects.Participants’ reasons for ending their engagement on any given day were: having to do other things, physical effects of the computer, scheduled event that ended, attention span or tired, computer or program issues. A small fraction of the participants also indicated experiencing negative feedback. Out of the participants who no longer took part in citizen science projects, some indicated that receiving negative feedback was their primary reason and others reported the program to be frustrating.Our work is helping us to understand participants who engage in online citizen science projects so that researchers can better design projects to meet their

  7. Risk assessment - black art or science?

    International Nuclear Information System (INIS)

    Moore, G.

    1988-01-01

    Measures of risk can be divided into two categories, those that observe or calculate the risk of a process or project, and those that rely on the level of risk as perceived by the people during the assessment. Collection of data of accidents (where cause and effect are obvious) and experiments on animals which can then be extrapolated to humans, are two ways of risk assessment. Mathematical models and computerized simulations, using either fault tree analysis or Monte Carlo methods are explained simply. Using these methods, experts are able to perceive risk fairly realistically. However, the general public's perception of risk is often quite different, as potential risk is assessed in different ways. The concept of tolerable risk is considered, particularly with reference to nuclear reactors such as Sizewell-B. The need to inform the public of safeguards and safety procedures so they have a better understanding of the risks of nuclear power is stressed. (U.K.)

  8. An Argument for Formative Assessment with Science Learning Progressions

    Science.gov (United States)

    Alonzo, Alicia C.

    2018-01-01

    Learning progressions--particularly as defined and operationalized in science education--have significant potential to inform teachers' formative assessment practices. In this overview article, I lay out an argument for this potential, starting from definitions for "formative assessment practices" and "learning progressions"…

  9. Beginning science teachers' performances: Assessment in times of reform

    Science.gov (United States)

    Budzinsky, Fie K.

    2000-10-01

    The current reform in science education and the research on effective teaching and student learning have reinforced the importance of teacher competency. To better measure performances in the teaching of science, performance assessment has been added to Connecticut's licensure process for beginning science teachers. Teaching portfolios are used to document teaching and learning over time. Portfolios, however, are not without problems. One of the major concerns with the portfolio assessment process is its subjectivity. Assessors may not have opportunities to ask clarifying or follow-up questions to enhance the interpretation of a teacher's performance. In addition, portfolios often contain components based on self-documentation, which are subjective. Furthermore, the use of portfolios raises test equity issues. These concerns present challenges for persons in charge of establishing the validity of a portfolio-based licensure process. In high-stakes decision processes, such as teaching licensure, the validity of the assessment instruments must be studied. The primary purpose of this study was to explore the criterion-related validity of the Connecticut State Department of Education's Beginning Science Teaching Portfolio by comparing the interpretations of performances from science teaching portfolios to those derived from another assessment method, the Expert Science Teaching Educational and Evaluation Model, (ESTEEM). The analysis of correlations between the Beginning Science Teaching Portfolio and ESTEEM instrument scores was the primary method for establishing support for validity. The results indicated moderate correlations between all Beginning Science Teaching Portfolio and ESTEEM category and total variables. Multiple regression was used to examine whether differences existed in beginning science teachers' performances based on gender, poverty group, school level, and science discipline taught. None of these variables significantly contributed to the

  10. Student explanations of their science teachers' assessments, grading practices and how they learn science

    Science.gov (United States)

    del Carmen Gomez, María

    2018-03-01

    The current paper draws on data generated through group interviews with students who were involved in a larger ethnographic research project performed in three science classrooms. The purpose of the study from which this data was generated, was to understand science teachers' assessment practices in an upper-secondary school in Sweden. During group interviews students were asked about their conceptions of what were the assessment priority of teachers, why the students were silent during lecturing and their experiences regarding peer- and self-assessments. The research design and analysis of the findings derives from what students told us about their assessments and learning sciences experiences. Students related that besides the results of the written test, they do not know what else teachers assessed and used to determine their grades. It was also found that students did not participate in the discussion on science because of peer-pressure and a fear of disappointing their peers. Student silence is also linked with student conceptions of science learning and student experiences with methodologies of teaching and learning sciences.

  11. Leaching characteristics of EDTA-enhanced phytoextraction of Cd and Pb by Zea mays L. in different particle-size fractions of soil aggregates exposed to artificial rain.

    Science.gov (United States)

    Lu, Yayin; Luo, Dinggui; Lai, An; Liu, Guowei; Liu, Lirong; Long, Jianyou; Zhang, Hongguo; Chen, Yongheng

    2017-01-01

    Chelator-assisted phytoextraction is an alternative and effective technique for the remediation of heavy metal-contaminated soils, but the potential for heavy metal leaching needs to be assessed. In the present study, a soil column cultivation-leaching experiment was conducted to investigate the Cd and Pb leaching characteristics during assisted phytoextraction of metal-contaminated soils containing different particle-size soil aggregates. The columns were planted with Zea mays "Zhengdan 958" seedlings and treated with combined applications of EDTA and simulated rainfall (pH 4.5 or 6.5). The results were as follows: (1) The greatest uptake of Cd and Pb by Z. mays was observed after treatment with EDTA (2.5 mmol kg -1 soil) and soil aggregates of  EDTA 2.5-1 (pH 6.5) > EDTA 2.5-2 (pH 4.5) > EDTA 2.5-4 (pH 4.5) > EDTA 2.5-2 (pH 6.5) > EDTA 2.5-4 (pH 6.5).

  12. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    Energy Technology Data Exchange (ETDEWEB)

    Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shen Zhenguo [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lou Laiqing [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: cexdli@polyu.edu.hk

    2006-12-15

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil.

  13. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    International Nuclear Information System (INIS)

    Luo Chunling; Shen Zhenguo; Lou Laiqing; Li Xiangdong

    2006-01-01

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil

  14. Intestinal permeability to (/sup 51/Cr)EDTA in children with Crohn's disease and celiac disease

    Energy Technology Data Exchange (ETDEWEB)

    Turck, D.; Ythier, H.; Maquet, E.; Deveaux, M.; Marchandise, X.; Farriaux, J.P.; Fontaine, G.

    1987-07-01

    (/sup 51/Cr)EDTA was used as a probe molecule to assess intestinal permeability in 7 healthy control adults, 11 control children, 17 children with Crohn's disease, and 6 children with untreated celiac disease. After subjects fasted overnight, 75 kBq/kg (= 2 microCi/kg) /sup 51/Cr-labeled EDTA was given by mouth; 24-h urinary excretion of (/sup 51/Cr)EDTA was measured and expressed as a percentage of the total oral dose. Mean and SD were as follows: control adults 1.47 +/- 0.62, control children 1.59 +/- 0.55, and patients with Crohn's disease or celiac disease 5.35 +/- 1.94. The difference between control children and patients was statistically significant (p less than 0.001). These results show that intestinal permeability to (/sup 51/Cr)EDTA is increased among children with active or inactive Crohn's disease affecting small bowel only or small bowel and colon, and with untreated celiac disease. The (/sup 51/Cr)EDTA permeability test could facilitate the decision to perform more extensive investigations in children suspected of small bowel disease who have atypical or poor clinical and biological symptomatology.

  15. Studies on biamperometric determination of thorium using EDTA as titrant

    International Nuclear Information System (INIS)

    Jayachandran, Kavitha; Nair, P.R.; Noronha, D.M.; Xavier, Mary; Aggarwal, S.K.

    2009-01-01

    A method is described for the determination of thorium at sub milligram levels by EDTA complexometric titration using biamperometric end point detection. The methodology is based on the electroactive behaviour of EDTA observed at pH 2-3, suggesting a reversible electron transfer reaction at potential ≥ 200 mV applied between twin Pt electrodes. Accuracy and precision of better than 2% were obtained for thorium amounts in the 100-500 μg range. (author)

  16. Amperometric titration of indium with edta solution in propanol

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Khadeev, V.A.; Kostylev, V.S.; Khadeeva, L.A.

    1980-01-01

    Optimum conditions have been chosen for titration of indium with EDTA solution in anhydrous propanol and its mixtures with some aprotic solvents using amperometric and point detection. A procedure is suggested of determining indium microcontents in the presence of large amounts of other elements. The procedure is based on its extraction preseparation followed by direct titration in the extract with a standard EDTA solution [ru

  17. Development and Validation of the Life Sciences Assessment: A Measure of Preschool Children's Conceptions of Basic Life Sciences

    Science.gov (United States)

    Maherally, Uzma Nooreen

    2014-01-01

    The purpose of this study was to develop and validate a science assessment tool termed the Life Sciences Assessment (LSA) in order to assess preschool children's conceptions of basic life sciences. The hypothesis was that the four sub-constructs, each of which can be measured through a series of questions on the LSA, will make a significant…

  18. Performance Assessment as a Diagnostic Tool for Science Teachers

    Science.gov (United States)

    Kruit, Patricia; Oostdam, Ron; van den Berg, Ed; Schuitema, Jaap

    2018-04-01

    Information on students' development of science skills is essential for teachers to evaluate and improve their own education, as well as to provide adequate support and feedback to the learning process of individual students. The present study explores and discusses the use of performance assessments as a diagnostic tool for formative assessment to inform teachers and guide instruction of science skills in primary education. Three performance assessments were administered to more than 400 students in grades 5 and 6 of primary education. Students performed small experiments using real materials while following the different steps of the empirical cycle. The mutual relationship between the three performance assessments is examined to provide evidence for the value of performance assessments as useful tools for formative evaluation. Differences in response patterns are discussed, and the diagnostic value of performance assessments is illustrated with examples of individual student performances. Findings show that the performance assessments were difficult for grades 5 and 6 students but that much individual variation exists regarding the different steps of the empirical cycle. Evaluation of scores as well as a more substantive analysis of students' responses provided insight into typical errors that students make. It is concluded that performance assessments can be used as a diagnostic tool for monitoring students' skill performance as well as to support teachers in evaluating and improving their science lessons.

  19. Effects of wheat-flour biscuits fortified with iron and EDTA, alone and in combination, on blood lead concentration, iron status, and cognition in children: a double-blind randomized controlled trial.

    Science.gov (United States)

    Bouhouch, Raschida R; El-Fadeli, Sana; Andersson, Maria; Aboussad, Abdelmounaim; Chabaa, Laila; Zeder, Christophe; Kippler, Maria; Baumgartner, Jeannine; Sedki, Azzedine; Zimmermann, Michael B

    2016-11-01

    Lead is a common neurotoxicant and its absorption may be increased in iron deficiency (ID). Thus, iron fortification to prevent ID in populations is a promising lead mitigation strategy. Two common fortificants are ferrous sulfate (FeSO 4 ) and ferric sodium EDTA (NaFeEDTA). EDTA can chelate iron and lead. Our study objective was to determine the effects of iron and EDTA, alone and in combination, on blood lead (BPb) concentration, iron status, and cognition. In this 2 × 2 factorial, double-blind placebo-controlled trial, 457 lead-exposed Moroccan children were stratified by school and grade and randomly assigned to consume biscuits (6 d/wk at school) containing 1) ∼8 mg Fe as FeSO 4 , 2) ∼8 mg Fe as NaFeEDTA that contained ∼41 mg EDTA, 3) ∼41 mg EDTA as sodium EDTA (Na 2 EDTA), or 4) placebo for 28 wk. The primary outcome was BPb concentration; secondary outcomes were iron status and cognitive outcomes from subtests of the Kaufman Assessment Battery for Children and the Hopkins Verbal Learning Test. These outcomes were measured at baseline and endpoint. All data were analyzed by intention-to-treat. The adjusted geometric mean BPb concentration at baseline was 4.3 μg/dL (95% CI: 4.2, 4.3 μg/dL), and at endpoint these values were 3.3 μg/dL (95% CI: 3.1, 3.5 μg/dL) for FeSO 4 , 2.9 μg/dL (95% CI: 2.7, 3.0 μg/dL) for NaFeEDTA, 3.3 μg/dL (95% CI: 3.1, 3.5 μg/dL) for EDTA, and 3.7 μg/dL (95% CI: 3.5, 3.9 μg/dL) for placebo. We found an effect of iron (P = 0.009) and EDTA (P = 0.012) for reduced BPb concentrations at endpoint, but no iron × EDTA interaction. Iron fortification improved iron status, but there were no positive effects of iron or EDTA on cognitive test scores. Food fortification with iron and EDTA additively reduces BPb concentrations. Our findings suggest that NaFeEDTA should be the iron fortificant of choice in lead-exposed populations. This trial was registered at clinicaltrials.gov as NCT01573013. © 2016 American Society for

  20. CaEDTA vs CaEDTA plus BAL to treat children with elevated blood lead levels.

    Science.gov (United States)

    O'Connor, M E

    1992-07-01

    The effectiveness of CaEDTA alone vs CaEDTA plus BAL was compared retrospectively in a group of 72 children with lead levels between 2.41 mumol/L (50 micrograms/dL) and 2.90 mumol/L (60 micrograms/dL). The children who received both drugs had higher median zinc protoporphyrin (ZnP) concentrations at the initiation of therapy than children who received CaEDTA alone (160 micrograms/dL vs 96 micrograms/dL, p less than .01). There was a significantly increased incidence of vomiting and abnormal liver-function test results in the children who received both drugs. The children who received CaEDTA alone had a greater percent mean fall in lead level at one to three weeks postchelation (30.5% vs 18.1%, p less than .05). Children who received both CaEDTA and BAL had a greater percent decrease in ZnP at four to eight months postchelation, but there was no difference in percent decrease in lead levels. Children who received both drugs also had a greater number of repeat courses of chelation by six months. The addition of BAL to CaEDTA for treatment of children with lead levels of 2.41 mumol/L (50 micrograms/dL) to 2.90 mumol/L (60 micrograms/dL) produced greater toxicity and does not seem to prevent repeat chelations within six months.

  1. Curriculum Assessment in Social Sciences at Universiti Pendidikan Sultan Idris

    Science.gov (United States)

    Saleh, Hanifah Mahat Yazid; Hashim, Mohmadisa; Yaacob, Norazlan Hadi; Kasim, Adnan Jusoh Ahmad Yunus

    2015-01-01

    The purpose of this paper is to discuss the effectiveness of the curriculum implementation for undergraduate programme in the Faculty of Human Sciences, UPSI producing quality and competitive educators. Curriculum implementation has to go through an assessment process that aims to determine the problem, select relevant information and collect and…

  2. 76 FR 38650 - Draft Integrated Science Assessment for Lead

    Science.gov (United States)

    2011-07-01

    ... Science Assessment for Lead AGENCY: Environmental Protection Agency. ACTION: Notice of extension of public... Lead'' (EPA/600/R-10/075A). The original Federal Register notice announcing the public comment period... review of the National Ambient Air Quality Standards (NAAQS) for Lead. DATES: The public comment period...

  3. Pedagogy of Science Teaching Tests: Formative assessments of science teaching orientations

    Science.gov (United States)

    Cobern, William W.; Schuster, David; Adams, Betty; Skjold, Brandy Ann; Zeynep Muğaloğlu, Ebru; Bentz, Amy; Sparks, Kelly

    2014-09-01

    A critical aspect of teacher education is gaining pedagogical content knowledge of how to teach science for conceptual understanding. Given the time limitations of college methods courses, it is difficult to touch on more than a fraction of the science topics potentially taught across grades K-8, particularly in the context of relevant pedagogies. This research and development work centers on constructing a formative assessment resource to help expose pre-service teachers to a greater number of science topics within teaching episodes using various modes of instruction. To this end, 100 problem-based, science pedagogy assessment items were developed via expert group discussions and pilot testing. Each item contains a classroom vignette followed by response choices carefully crafted to include four basic pedagogies (didactic direct, active direct, guided inquiry, and open inquiry). The brief but numerous items allow a substantial increase in the number of science topics that pre-service students may consider. The intention is that students and teachers will be able to share and discuss particular responses to individual items, or else record their responses to collections of items and thereby create a snapshot profile of their teaching orientations. Subsets of items were piloted with students in pre-service science methods courses, and the quantitative results of student responses were spread sufficiently to suggest that the items can be effective for their intended purpose.

  4. Assessing the Genetics Content in the Next Generation Science Standards.

    Directory of Open Access Journals (Sweden)

    Katherine S Lontok

    Full Text Available Science standards have a long history in the United States and currently form the backbone of efforts to improve primary and secondary education in science, technology, engineering, and math (STEM. Although there has been much political controversy over the influence of standards on teacher autonomy and student performance, little light has been shed on how well standards cover science content. We assessed the coverage of genetics content in the Next Generation Science Standards (NGSS using a consensus list of American Society of Human Genetics (ASHG core concepts. We also compared the NGSS against state science standards. Our goals were to assess the potential of the new standards to support genetic literacy and to determine if they improve the coverage of genetics concepts relative to state standards. We found that expert reviewers cannot identify ASHG core concepts within the new standards with high reliability, suggesting that the scope of content addressed by the standards may be inconsistently interpreted. Given results that indicate that the disciplinary core ideas (DCIs included in the NGSS documents produced by Achieve, Inc. clarify the content covered by the standards statements themselves, we recommend that the NGSS standards statements always be viewed alongside their supporting disciplinary core ideas. In addition, gaps exist in the coverage of essential genetics concepts, most worryingly concepts dealing with patterns of inheritance, both Mendelian and complex. Finally, state standards vary widely in their coverage of genetics concepts when compared with the NGSS. On average, however, the NGSS support genetic literacy better than extant state standards.

  5. Assessing the Genetics Content in the Next Generation Science Standards.

    Science.gov (United States)

    Lontok, Katherine S; Zhang, Hubert; Dougherty, Michael J

    2015-01-01

    Science standards have a long history in the United States and currently form the backbone of efforts to improve primary and secondary education in science, technology, engineering, and math (STEM). Although there has been much political controversy over the influence of standards on teacher autonomy and student performance, little light has been shed on how well standards cover science content. We assessed the coverage of genetics content in the Next Generation Science Standards (NGSS) using a consensus list of American Society of Human Genetics (ASHG) core concepts. We also compared the NGSS against state science standards. Our goals were to assess the potential of the new standards to support genetic literacy and to determine if they improve the coverage of genetics concepts relative to state standards. We found that expert reviewers cannot identify ASHG core concepts within the new standards with high reliability, suggesting that the scope of content addressed by the standards may be inconsistently interpreted. Given results that indicate that the disciplinary core ideas (DCIs) included in the NGSS documents produced by Achieve, Inc. clarify the content covered by the standards statements themselves, we recommend that the NGSS standards statements always be viewed alongside their supporting disciplinary core ideas. In addition, gaps exist in the coverage of essential genetics concepts, most worryingly concepts dealing with patterns of inheritance, both Mendelian and complex. Finally, state standards vary widely in their coverage of genetics concepts when compared with the NGSS. On average, however, the NGSS support genetic literacy better than extant state standards.

  6. Everyday classroom assessment practices in science classrooms in Sweden

    Science.gov (United States)

    Gómez, María del Carmen; Jakobsson, Anders

    2014-12-01

    The focus of this study is to examine to what extent and in what ways science teachers practice assessment during classroom interactions in everyday activities in an upper-secondary school in Sweden. We are science teachers working now with a larger research project on assessment in science education that seeks to examine teachers' assessment practices in the upper-secondary school. Framing questions include: are teachers performing an integrated assessment of students' skills as the national curriculum mandates? If so, what do the instructional discourses look like in those situations and what are students' experiences regarding their agency on learning and assessment? We emphasize the social, cultural and historic character of assessment and sustain a situated character of learning instead of the notion that learning is "stored inside the head". Teacher led lessons in three science classrooms were video-recorded and analyzed by combining ethnographic and discourse methods of analysis. Both methods are appropriate to the theoretical foundation of our approach on learning and can give some answers to questions about how individuals interact socially, how their experience is passed on to next generations through language and how language use may reveal cultural changes in the studied context. Making the study of action in a classroom the focal point of sociocultural analysis supports the examination of assessment processes and identification of the social roles in which teachers and students are immersed. Such an approach requires observations of how teachers act in authentic teaching situations when they interact with their students in classroom making possible to observe negotiation processes, agencies when both teachers and students are involved in every-day activities. Our study showed that teachers mostly ignored students' questions and that students solved their own problems by helping each other. Teachers did not provide opportunities for students to discuss

  7. Relationship between intestinal permeability to [51Cr]EDTA and inflammatory activity in asymptomatic patients with Crohn's disease

    International Nuclear Information System (INIS)

    Pironi, L.; Miglioli, M.; Ruggeri, E.; Levorato, M.; Dallasta, M.A.; Corbelli, C.; Nibali, M.G.; Barbara, L.

    1990-01-01

    The relationship between intestinal permeability to an oral dose (100 mu Ci) of [51CR]EDTA and the inflammatory activity of Crohn's disease was studied in 63 adult patients (32 unresected and 31 resected) who underwent 162 evaluations. The results of the [51CR]EDTA test were compared with the serum levels of the acute-phase reactant proteins (APRP) and with the result of the [111In]leukocyte scanning, respectively, as an indirect and direct method to assess intestinal inflammation. In a group of healthy adult controls, the upper normal value for the 24-hr urinary [51CR]EDTA excretion was 3.61 (97.5% percentile) and the mean coefficient of variation was 21%. Sensitivity and specificity of the [51CR]EDTA test in identifying active inflammation expressed by increased serum levels of APRP were, respectively, 97% and 54% in the unresected group and 68% and 52% in the resected group of patients. The low specificity of the test was due to the presence of increased [51CR]EDTA urinary excretion in about half the cases with normal serum levels of APRP. The [111In]leukocyte scanning was performed in a subgroup of 11 patients (three unresected and eight resected) with normal serum levels of APRP, six with increased and five with normal [51CR]EDTA urinary excretion. All six patients with increased intestinal permeability had a positive 111In image of mild to moderate degree of activity. A positive 111In scan was present in two of the five patients with normal permeability; these were two resected patients

  8. The Effect of an EDTA-based Chelation Regimen on Patients with Diabetes and Prior Myocardial Infarction in TACT

    Science.gov (United States)

    Escolar, Esteban; Lamas, Gervasio A.; Mark, Daniel B.; Boineau, Robin; Goertz, Christine; Rosenberg, Yves; Nahin, Richard L.; Ouyang, Pamela; Rozema, Theodore; Magaziner, Allan; Nahas, Richard; Lewis, Eldrin F.; Lindblad, Lauren; Lee, Kerry L.

    2014-01-01

    Background The Trial to Assess Chelation Therapy (TACT) showed clinical benefit of an ethylene diamine tetraacetic acid (EDTA-based) infusion regimen in patients 50 years or older with prior myocardial infarction (MI). Diabetes prior to enrollment was a pre-specified subgroup. Methods and Results Patients received 40 infusions of EDTA chelation or placebo. 633 (37%) had diabetes (322 EDTA, 311 placebo). EDTA reduced the primary endpoint (death, reinfarction, stroke, coronary revascularization, or hospitalization for angina) [25% vs 38%, hazard ratio (HR) 0.59, 95% confidence interval (CI) (0.44, 0.79), p<0.001] over 5 years. The result remained significant after Bonferroni adjustment for multiple subgroups (99.4% CI (0.39, 0.88), adjusted p=0.002). All-cause mortality was reduced by EDTA chelation [10% vs 16%, HR 0.57, 95% CI (0.36, 0.88) p=0.011], as was the secondary endpoint (cardiovascular death, reinfarction, or stroke) [11% vs 17% HR 0.60, 95% CI (0.39, 0.91), p=0.017]. After adjusting for multiple subgroups, however, those results were no longer significant. The number needed to treat to reduce one primary endpoint was 6.5 over 5 years (95% CI (4.4, 12.7). There was no reduction in events in non-diabetics (n=1075, p=0.877), resulting in a treatment by diabetes interaction (p=0.004). Conclusions Post-MI diabetic patients age 50 or older demonstrated a marked reduction in cardiovascular events with EDTA chelation. These findings support efforts to replicate these findings and define the mechanisms of benefit. They do not, however, constitute sufficient evidence to indicate the routine use of chelation therapy for all post-MI diabetic patients. PMID:24254885

  9. Physical sciences and engineering advances in life sciences and oncology a WTEC global assessment

    CERN Document Server

    Fletcher, Daniel; Gerecht, Sharon; Levine, Ross; Mallick, Parag; McCarty, Owen; Munn, Lance; Reinhart-King, Cynthia

    2016-01-01

    This book presents an Assessment of Physical Sciences and Engineering Advances in Life Sciences and Oncology (APHELION) by a panel of experts. It covers the status and trends of applying physical sciences and engineering principles to oncology research in leading laboratories and organizations in Europe and Asia. The book elaborates on the six topics identified by the panel that have the greatest potential to advance understanding and treatment of cancer, each covered by a chapter in the book. The study was sponsored by the National Cancer Institute (NCI) at the National Institute of Health (NIH), the National Science Foundation (NSF) and the National Institute of Biomedical Imaging and Bioengineering at the NIH in the US under a cooperative agreement with the World Technology Evaluation Center (WTEC).

  10. Assessment for Learning in Inquiry Based Science Education

    DEFF Research Database (Denmark)

    Fornaguera, Cristina Carulla

    The study looks at assessment for learning and Inquiry Based Science Education —IBSE— as concepts established in a diversity of geographical areas, where the traditional summative assessment shapes what most individuals share as being experienced as assessment. Based on Leontiev and Radford...... the analytical process. The main contribution was the analysis and the results of researcher movement from a view of assessment considering learning as a psychological process in the mind, independent of the everyday life of individuals, towards one considering the inseparability of collective and individual...... as identifying and differentiating forms of researching assessment, changing the researcher’s perspective on research, and imagining a new theoretical approach to assessment for learning....

  11. Integrated Science Assessment (ISA) of Ozone and Related ...

    Science.gov (United States)

    EPA announced the availability of the final report, Integrated Science Assessment of Ozone and Related Photochemical Oxidants. This document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision regarding the adequacy of the current national ambient air quality standards for ozone to protect human health, public welfare, and the environment. Critical evaluation and integration of the evidence on health and environmental effects of ozone to provide scientific support for the review of the NAAQS for ozone.

  12. EDTA modified glassy carbon electrode: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ustuendag, Zafer [Dumlupinar University, Faculty of Arts and Sciences, Department of Chemistry, Kuetahya (Turkey); Solak, Ali Osman [Ankara University, Faculty of Science, Department of Chemistry, Degol Street, Tandogan, 06100 Ankara (Turkey)], E-mail: osolak@science.ankara.edu.tr

    2009-11-01

    EDTA-phenoxyamide modified glassy carbon electrode (EDTA-GC) was prepared at a glassy carbon electrode by surface synthesis. In the first step, nitrophenyl was grafted to the glassy carbon (GC) surface via the electrochemical reduction of its tetraflouroborate diazonium salt. In the second step, nitrophenyl-modified electrode (NP-GC) was subjected to the cathodic potential scan to reduce the nitro to amine group. p-Aminophenyl modified glassy carbon electrode (AP-GC) was dipped into a EDTA solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide (EDC) as an activating agent. Thus formed ((2-anilino-2-oxoethyl){l_brace}2-[bis(carboxymethyl)amino]-ethyl{r_brace}amino)acetic acid modified GC electrode was denoted as EDTA-GC and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ellipsometry and X-ray photoelectron spectroscopy (XPS). Complexation of the EDTA-GC surface with Pb{sup 2+} ions was investigated if this electrode could be used as a metal sensor.

  13. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  14. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2009-01-01

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10 -10 nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  15. Effect of edta on arsenic phytoextraction by arundo donax

    International Nuclear Information System (INIS)

    Mirza, N.; Pervez, A.; Mahmood, Q.; Shah, M.M.; Farooq, U.

    2014-01-01

    Ligand assisted metal uptake by plants is recent trend in environmental clean-up. Arundo donax L. has been demonstrated as a suitable bioresource for the phytoextraction of arsenic recently. A. donax L. plants were grown in arsenic contaminated soil with doses (5 and 10 mg kg/sup -1/) of Ethylene Diamine Tetra Acetic Acid (EDTA) to investigate chelator-assisted phytoextraction. The arsenic treatments included control (no metal) and five doses of arsenic, i.e., 50, 100, 300, 600 and 1000 micro g kg/sup -1/ . The arsenic concentrations linearly increased in parts of plant with the increasing arsenic and EDTA in growth medium. Ligand addition also resulted in the increased arsenic accumulation in the shoot over its control plants. EDTA additionat the rate 5 mg kg/sup -1/ to the treatment system may effectively increase the arsenic uptake by A. donax without severe growth suppression. (author)

  16. Results of Needs Assessments Related to Citizen Science Projects

    Science.gov (United States)

    Buxner, Sanlyn; Bracey, Georgia; Glushko, Anna; Bakerman, Maya; Gay, Pamela L.; CosmoQuest Team

    2017-01-01

    The CosmoQuest Virtual Research Facility invites the public and classrooms to participate in NASA Science Mission Directorate related research that leads to publishable results and data catalogues. One of the main goals of the project is to support professional scientists in doing science and the general public--including parents, children, teachers, and students--in learning and doing science. Through the effort, the CosmoQuest team is developing a variety of supports and opportunities to support the doing and teaching of science. To inform our efforts, we have implemented a set of needs surveys to assess the needs of our different audiences. These surveys are being used to understand the interests, motivations, resources, challenges and demographics of our growing CosmoQuest community and others interested in engaging in citizen science projects. The surveys include those for teachers, parents, adult learners, planetarium professionals, subject matter experts (SMEs), and the general public. We will share the results of these surveys and discuss the implications of the results for broader education and outreach programs.

  17. Quality Assessment of Collection 6 MODIS Atmospheric Science Products

    Science.gov (United States)

    Manoharan, V. S.; Ridgway, B.; Platnick, S. E.; Devadiga, S.; Mauoka, E.

    2015-12-01

    Since the launch of the NASA Terra and Aqua satellites in December 1999 and May 2002, respectively, atmosphere and land data acquired by the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor on-board these satellites have been reprocessed five times at the MODAPS (MODIS Adaptive Processing System) located at NASA GSFC. The global land and atmosphere products use science algorithms developed by the NASA MODIS science team investigators. MODAPS completed Collection 6 reprocessing of MODIS Atmosphere science data products in April 2015 and is currently generating the Collection 6 products using the latest version of the science algorithms. This reprocessing has generated one of the longest time series of consistent data records for understanding cloud, aerosol, and other constituents in the earth's atmosphere. It is important to carefully evaluate and assess the quality of this data and remove any artifacts to maintain a useful climate data record. Quality Assessment (QA) is an integral part of the processing chain at MODAPS. This presentation will describe the QA approaches and tools adopted by the MODIS Land/Atmosphere Operational Product Evaluation (LDOPE) team to assess the quality of MODIS operational Atmospheric products produced at MODAPS. Some of the tools include global high resolution images, time series analysis and statistical QA metrics. The new high resolution global browse images with pan and zoom have provided the ability to perform QA of products in real time through synoptic QA on the web. This global browse generation has been useful in identifying production error, data loss, and data quality issues from calibration error, geolocation error and algorithm performance. A time series analysis for various science datasets in the Level-3 monthly product was recently developed for assessing any long term drifts in the data arising from instrument errors or other artifacts. This presentation will describe and discuss some test cases from the

  18. Improving Assessment Methods in University Science Education with Negotiated Self- and Peer-Assessment

    Science.gov (United States)

    Poon, Wai-Yin; McNaught, Carmel; Lam, Paul; Kwan, H. S.

    2009-01-01

    The aim of this study was to investigate whether, in the Hong Kong context, self- and peer-assessment promote students' self-reflection and enable students to understand their own strengths and weaknesses better. A three-stage assessment strategy was employed in three Science courses at The Chinese University of Hong Kong: (1) students developing…

  19. 78 FR 66892 - BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment...

    Science.gov (United States)

    2013-11-07

    .... Kevin Shea, Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-26701 Filed 11-6-13... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2012-0028] BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment for...

  20. Simultaneous absorption of NO and SO{sub 2} into Fe-II-EDTA solution coupled with the Fe-II-EDTA regeneration catalyzed by activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.S.; Mao, Y.P.; Yang, X.J.; Chen, Y.; Long, X.L.; Yuan, W.K. [East China University of Science & Technology, Shanghai (China)

    2010-07-30

    The simultaneous removal of NO and SO{sub 2} from flue gases can be realized with Fe(II)-ethylenediamineteraacetate (EDTA) solution. Activated carbon is used to catalyze the reduction of Fe-III-EDTA to Fe-II-EDTA to maintain the capability of removing NO of the Fe-EDTA solution. The reductant is the sulfite/bisulfite ions produced by SO{sub 2} dissolving into the aqueous solution. Experiments have been performed to determine the effects of activated carbon of coconut shell, Fe-II-EDTA concentration, Fe/EDTA molar ratio, SO{sub 2} partial pressure, NO partial pressure and SO{sub 4}{sup 2-} concentration on the combined elimination of NO and SO{sub 2} with Fe-II-EDTA solution coupled with the Fe-II-EDTA regeneration catalyzed by activated carbon. According to the experimental results, activated carbon not only catalyzes the reduction of Fe-III-EDTA by sulfite/bisulfite greatly but also avoids the release of N{sub 2}O. The NO removal efficiency increases with the initial Fe-II-EDTA concentration and SO{sub 2} partial pressure. The ratio of Fe/EDTA and the SO{sub 4}{sup 2-} concentration has little effect on the catalytic reduction of Fe-III-EDTA. The optimal initial NO concentration range is from 600 ppm to 900 ppm. The experimental results manifest that the Fe-II-EDTA solution coupled with catalytic regeneration of Fe-II-EDTA can maintain high nitric oxide removal efficiency for a long period of time.

  1. The National Climate Assessment as a Resource for Science Communication

    Science.gov (United States)

    Somerville, R. C. J.

    2014-12-01

    The 2014 Third National Climate Assessment (NCA3) is scientifically authoritative and features major advances, relative to other assessments produced by several organizations. NCA3 is a valuable resource for communicating climate science to a wide variety of audiences. Other assessments were often overly detailed and laden with scientific jargon that made them appear too complex and technical to many in their intended audiences, especially policymakers, the media, and the broad public. Some other assessments emphasized extensive scientific caveats, quantitative uncertainty estimates and broad consensus support. All these attributes, while valuable in research, carry the risk of impeding science communication to non-specialists. Without compromising scientific accuracy and integrity, NCA3 is written in exceptionally clear and vivid English. It includes outstanding graphics and employs powerful techniques aimed at conveying key results unambiguously to a wide range of audiences. I have used NCA3 as a resource in speaking about climate change in three very different settings: classroom teaching for undergraduate university students, presenting in academia to historians and other non-scientists, and briefing corporate executives working on renewable energy. NCA3 proved the value of developing a climate assessment with communication goals and strategies given a high priority throughout the process, not added on as an afterthought. I draw several lessons. First, producing an outstanding scientific assessment is too complex and demanding a task to be carried out by scientists alone. Many types of specialized expertise are also needed. Second, speaking about science to a variety of audiences requires an assortment of communication skills and tools, all tailored to specific groups of listeners. Third, NCA3 is scientifically impeccable and is also an outstanding example of effective communication as well as a valuable resource for communicators.

  2. After the Cap: Risk Assessment, Citizen Science and Disaster Recovery

    Directory of Open Access Journals (Sweden)

    Sabrina McCormick

    2012-12-01

    Full Text Available I used the 2010 Deepwater Horizon oil spill to examine how crowdsourcing is used as a new form of citizen science that provides real time assessments of health-related exposures. Assessing risks of an oil spill, or disasters more generally, is a challenge complicated by the situated nature of knowledge-generation that results in differential perceptions and responses. These processes are critical in the case of the British Petroleum spill in the Gulf Coast since the identification of risks promises to have ramifications for multiple social actors, as well as the health status and long-term resilience of communities in the area. Qualitative interviews, ethnographic observations, and video data were collected with local social movement organizations, grassroots groups, spill workers, fisherman, local residents, scientists, and government representatives within five months of the spill. Findings suggest that crowdsourcing is a new form of citizen science reflecting a transition from lay mapping to an online data gathering system that allows a broader range of participation and the detection of a broader range of impacts. Outcomes of this research promise to help demonstrate and theorize how citizen science relates to risk assessment processes and affects disaster recovery and long-term response.

  3. Dissolution of Fe(III) (hydr) oxides by metal-EDTA complexes

    Science.gov (United States)

    Ngwack, Bernd; Sigg, Laura

    1997-03-01

    The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA CaEDTA ≫ PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced.

  4. A Scale to Assess Science Activity Videos (SASAV): The Study of Validity and Reliability

    Science.gov (United States)

    Kara, Yilmaz; Bakirci, Hasan

    2018-01-01

    The purpose of the study was to develop an assessment scale for science activity videos that can be used to determine qualified science activity videos that can fulfill the objectives of activity based science education, help teachers to evaluate any science activity videos and decide whether to include into science learning process. The subjects…

  5. Taking Stock: Existing Resources for Assessing a New Vision of Science Learning

    Science.gov (United States)

    Alonzo, Alicia C.; Ke, Li

    2016-01-01

    A new vision of science learning described in the "Next Generation Science Standards"--particularly the science and engineering practices and their integration with content--pose significant challenges for large-scale assessment. This article explores what might be learned from advances in large-scale science assessment and…

  6. Safari Science: Assessing the reliability of citizen science data for wildlife surveys

    Science.gov (United States)

    Steger, Cara; Butt, Bilal; Hooten, Mevin B.

    2017-01-01

    Protected areas are the cornerstone of global conservation, yet financial support for basic monitoring infrastructure is lacking in 60% of them. Citizen science holds potential to address these shortcomings in wildlife monitoring, particularly for resource-limited conservation initiatives in developing countries – if we can account for the reliability of data produced by volunteer citizen scientists (VCS).This study tests the reliability of VCS data vs. data produced by trained ecologists, presenting a hierarchical framework for integrating diverse datasets to assess extra variability from VCS data.Our results show that while VCS data are likely to be overdispersed for our system, the overdispersion varies widely by species. We contend that citizen science methods, within the context of East African drylands, may be more appropriate for species with large body sizes, which are relatively rare, or those that form small herds. VCS perceptions of the charisma of a species may also influence their enthusiasm for recording it.Tailored programme design (such as incentives for VCS) may mitigate the biases in citizen science data and improve overall participation. However, the cost of designing and implementing high-quality citizen science programmes may be prohibitive for the small protected areas that would most benefit from these approaches.Synthesis and applications. As citizen science methods continue to gain momentum, it is critical that managers remain cautious in their implementation of these programmes while working to ensure methods match data purpose. Context-specific tests of citizen science data quality can improve programme implementation, and separate data models should be used when volunteer citizen scientists' variability differs from trained ecologists' data. Partnerships across protected areas and between protected areas and other conservation institutions could help to cover the costs of citizen science programme design and implementation.

  7. Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol

    Science.gov (United States)

    Underwood, Sonia M.; Matz, Rebecca L.; Posey, Lynmarie A.; Carmel, Justin H.; Caballero, Marcos D.; Fata-Hartley, Cori L.; Ebert-May, Diane; Jardeleza, Sarah E.; Cooper, Melanie M.

    2016-01-01

    Many calls to improve science education in college and university settings have focused on improving instructor pedagogy. Meanwhile, science education at the K-12 level is undergoing significant changes as a result of the emphasis on scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. This framework of “three-dimensional learning” is based on the literature about how people learn science and how we can help students put their knowledge to use. Recently, similar changes are underway in higher education by incorporating three-dimensional learning into college science courses. As these transformations move forward, it will become important to assess three-dimensional learning both to align assessments with the learning environment, and to assess the extent of the transformations. In this paper we introduce the Three-Dimensional Learning Assessment Protocol (3D-LAP), which is designed to characterize and support the development of assessment tasks in biology, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not. PMID:27606671

  8. Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol.

    Science.gov (United States)

    Laverty, James T; Underwood, Sonia M; Matz, Rebecca L; Posey, Lynmarie A; Carmel, Justin H; Caballero, Marcos D; Fata-Hartley, Cori L; Ebert-May, Diane; Jardeleza, Sarah E; Cooper, Melanie M

    2016-01-01

    Many calls to improve science education in college and university settings have focused on improving instructor pedagogy. Meanwhile, science education at the K-12 level is undergoing significant changes as a result of the emphasis on scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. This framework of "three-dimensional learning" is based on the literature about how people learn science and how we can help students put their knowledge to use. Recently, similar changes are underway in higher education by incorporating three-dimensional learning into college science courses. As these transformations move forward, it will become important to assess three-dimensional learning both to align assessments with the learning environment, and to assess the extent of the transformations. In this paper we introduce the Three-Dimensional Learning Assessment Protocol (3D-LAP), which is designed to characterize and support the development of assessment tasks in biology, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not.

  9. Integrated Science Assessment (ISA) for Oxides of Nitrogen ...

    Science.gov (United States)

    This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision on retaining or revising the current secondary standards for NO2, SO2, PM 2.5 and PM 10 since the prior release of the assessment. The intent of the ISA, according to the CAA, is to “accurately reflect the latest scientific knowledge expected from the presence of [a] pollutant in ambient air” (U.S. Code, 1970a, 1970b). It includes scientific research from atmospheric sciences, exposure and deposition, biogeochemistry, hydrology, soil science, marine science, plant physiology, animal physiology, and ecology conducted at multiple scales (e.g., population, community, ecosystem, landscape levels). Key information and judgments formerly found in the Air Quality Criteria Documents (AQCDs) for oxides of nitrogen, oxides of nitrogen and particulate matter for ecological effects are included; Appendixes provide additional details supporting the ISA. Together, the ISA and Appendixes serve to update and revise the last oxides of nitrogen and oxides of sulfur ISA which was published in 2008 and the ecological portion of the last particulate matter ISA, which was published in 2009.

  10. Social Science Boot Camp: Development and Assessment of a Foundational Course on Academic Literacy in the Social Sciences

    Science.gov (United States)

    Eaton, Judy; Long, Jennifer; Morris, David

    2018-01-01

    We developed a course, as part of our institution's core program, which provides students with a foundation in academic literacy in the social sciences: how to find, read, critically assess, and communicate about social science research. It is not a research methods course; rather, it is intended to introduce students to the social sciences and be…

  11. Students Explaining Science—Assessment of Science Communication Competence

    Science.gov (United States)

    Kulgemeyer, Christoph; Schecker, Horst

    2013-12-01

    Science communication competence (SCC) is an important educational goal in the school science curricula of several countries. However, there is a lack of research about the structure and the assessment of SCC. This paper specifies the theoretical framework of SCC by a competence model. We developed a qualitative assessment method for SCC that is based on an expert-novice dialog: an older student (explainer, expert) explains a physics phenomenon to a younger peer (addressee, novice) in a controlled test setting. The explanations are video-recorded and analysed by qualitative content analysis. The method was applied in a study with 46 secondary school students as explainers. Our aims were (a) to evaluate whether our model covers the relevant features of SCC, (b) to validate the assessment method and (c) to find characteristics of addressee-adequate explanations. A performance index was calculated to quantify the explainers' levels of competence on an ordinal scale. We present qualitative and quantitative evidence that the index is adequate for assessment purposes. It correlates with results from a written SCC test and a perspective taking test (convergent validity). Addressee-adequate explanations can be characterized by use of graphical representations and deliberate switches between scientific and everyday language.

  12. EFFECTS OF EDTA ON LEA indica) SEEDLINGS REPLANTE ECTS ...

    African Journals Online (AJOL)

    userpc

    Lead (Pb) is one of the widely distributed an most abundant toxic elements in the soil. exerts adverse effects on ... on morphology, growth esses of plants. 1975 ... l plants. The harvesting or EDTA. The pH ntration of Pb2+ before er harvest. The weights .... reported that toxicity symptoms in Indian mustard exposed to Pb and.

  13. Measurement of intestinal permeability using 51Cr-EDTA

    International Nuclear Information System (INIS)

    Peled, Y.; Watz, C.; Gilat, T.

    1985-01-01

    Intestinal permeability tests are a new class of tests of which the 51 Cr-EDTA seemed the easiest to perform. The authors have evaluated the 8- and 24-h urinary excretion of ingested 51 Cr-EDTA in 38 subjects. Twenty-seven patients with diseases not affecting the integrity of the small bowel served as controls. The test group consisted of two patients with celiac, six with Crohn's disease, and three with ulcerative colitis. Nineteen (70.37%) of the control patients had an abnormal test (more than 2.6% in 24 h). The patients with ulcerative colitis had normal excretion (mean 1.95% in 24 h). The patients with celiac disease had an elevated excretion (mean 3.62% in 24 h) and five out of six patients with Crohn's disease also had an increased excretion (mean 6.2% in 24 h). The elevated 51 Cr-EDTA excretion in the control patients casts serious doubts on the validity of the test. Possible causes for abnormal excretion in the controls include various medications used by the patients as well as changes in the chromatographic mobility of 51 Cr-EDTA, demonstrated after incubation with gastric juice

  14. Teaching and Assessing Teamwork Skills in Engineering and Computer Science

    Directory of Open Access Journals (Sweden)

    Robert W. Lingard

    2010-02-01

    Full Text Available To be successful in today's workplace, engineering and computer science students must possess high levels of teamwork skills. Unfortunately, most engineering programs provide little or no specific instruction in this area. This paper outlines an assessment-driven approach toward teaching teamwork skills. Working with the Industrial Advisory Board for the College, a set of performance criteria for teamwork was developed. This set of criteria was used to build an assessment instrument to measure the extent to which students are able to achieve the necessary skills. This set of criteria provides a clear basis for the development of an approach toward teaching teamwork skills. Furthermore, the results from the assessment can be used to adjust the teaching techniques to address the particular skills where students show some weaknesses. Although this effort is in the early stages, the approach seems promising and will be improved over time.

  15. Reinforcement of qualitative risk assessment proposals from computer science

    International Nuclear Information System (INIS)

    Friedlhuber, T.; Hibti, M.; Rauzy, A.

    2013-01-01

    During the last decade a lot of research has been made to evaluate concepts and methos of quantitative risk assessment in order to predict hazards more precisely. Nevertheless, the occurrence of new catastrophes like the Indonesian Tsunami in 2004, the Deepwater Horizon accident in 2010 or recently the Fukushima accidents in 2011 raise the question whether we may underestimate some natural limits of annotative risk assessment or even mistake its significance. Especially in the case of very unlikely events, in combination with uncertainty and severe consequences, may be we would do better to concentrate more on understanding risk than on calculating probability values. In this paper we apply progresses, made in the field of computer science, to tools and modelling concepts used in risk assessment. Regarding computer science, we point out now concepts, that may improve the quality of risk models and the process of model engineering. The goal is to reinforce the importance of qualitative risk assessment with the help of sophisticated tools and modelling. Qualitative risk assessment aims to understand risk and therefore reflects the initial idea of risk assessment. Risk understanding requires understanding systems and relations of components. It is fundamental to comprehend the meaning of components in fault- and event trees, to retrace all applied modifications and to highlight critical aspects. It is important how PSA models are visualized, documented, navigated, how results are presented and how model maintenance, integration and version control are performed. Also, the conjoint usage of different type of models (for example PSA models together with event sequence diagrams) can contribute to quality assurance. We present new concepts for various kind of problems. (author)

  16. Assessment for Effective Intervention: Enrichment Science Academic Program

    Science.gov (United States)

    Sasson, Irit; Cohen, Donita

    2013-10-01

    Israel suffers from a growing problem of socio-economic gaps between those who live in the center of the country and residents of outlying areas. As a result, there is a low level of accessibility to higher education among the peripheral population. The goal of the Sidney Warren Science Education Center for Youth at Tel-Hai College is to strengthen the potential of middle and high school students and encourage them to pursue higher education, with an emphasis on majoring in science and technology. This study investigated the implementation and evaluation of the enrichment science academic program, as an example of informal learning environment, with an emphasis on physics studies. About 500 students conducted feedback survey after participating in science activities in four domains: biology, chemistry, physics, and computer science. Results indicated high level of satisfaction among the students. No differences were found with respect to gender excluding in physics with a positive attitudes advantage among boys. In order to get a deeper understanding of this finding, about 70 additional students conducted special questionnaires, both 1 week before the physics enrichment day and at the end of that day. Questionnaires were intended to assess both their attitudes toward physics and their knowledge and conceptions of the physical concept "pressure." We found that the activity moderately improved boys' attitudes toward physics, but that girls displayed decreased interest in and lower self-efficacy toward physics. Research results were used to the improvement of the instructional design of the physics activity demonstrating internal evaluation process for effective intervention.

  17. Breathing life into fisheries stock assessments with citizen science.

    Science.gov (United States)

    Fairclough, D V; Brown, J I; Carlish, B J; Crisafulli, B M; Keay, I S

    2014-11-28

    Citizen science offers a potentially cost-effective way for researchers to obtain large data sets over large spatial scales. However, it is not used widely to support biological data collection for fisheries stock assessments. Overfishing of demersal fishes along 1,000 km of the west Australian coast led to restrictive management to recover stocks. This diminished opportunities for scientists to cost-effectively monitor stock recovery via fishery-dependent sampling, particularly of the recreational fishing sector. As fishery-independent methods would be too expensive and logistically-challenging to implement, a citizen science program, Send us your skeletons (SUYS), was developed. SUYS asks recreational fishers to voluntarily donate fish skeletons of important species from their catch to allow biological data extraction by scientists to produce age structures and conduct stock assessment analyses. During SUYS, recreational fisher involvement, sample sizes and spatial and temporal coverage of samples have dramatically increased, while the collection cost per skeleton has declined substantially. SUYS is ensuring sampling objectives for stock assessments are achieved via fishery-dependent collection and reliable and timely scientific advice can be provided to managers. The program is also encouraging public ownership through involvement in the monitoring process, which can lead to greater acceptance of management decisions.

  18. Interactions between the Tetrasodium Salts of EDTA and 1-Hydroxyethane 1,1-Diphosphonic Acid with Sodium Hypochlorite Irrigants.

    Science.gov (United States)

    Biel, Philippe; Mohn, Dirk; Attin, Thomas; Zehnder, Matthias

    2017-04-01

    A clinically useful all-in-one endodontic irrigant with combined proteolytic and decalcifying properties is still elusive. In this study, the chemical effects of dissolving the tetrasodium salts of 1-hydroxyethane 1,1-diphosphonic acid (Na 4 HEDP) or Na 4 EDTA directly in sodium hypochlorite (NaOCl) irrigants in polypropylene syringes were assessed during the course of 1 hour. The solubility of the salts in water was determined. Their compatibility with 1% and 5% NaOCl was measured by iodometric titration and in a calcium complexation experiment by using a Ca 2+ -selective electrode. The salts dissolved within 1 minute. The dissolution maximum of Na 4 HEDP in water (wt/total wt) was 44.6% ± 1.6%. The corresponding dissolution maximum of Na 4 EDTA was 38.2% ± 0.8%. Na 4 HEDP at 18% in 5% NaOCl caused a mere loss of 16% of the initially available chlorine during 1 hour. In contrast, a corresponding mixture between NaOCl and the Na 4 EDTA salt caused 95% reduction in available chlorine after 1 minute. Mixtures of 3% Na 4 EDTA with 1% NaOCl were more stable, but only for 30 minutes. Na 4 HEDP lost 24% of its calcium complexation capacity after 60 minutes. The corresponding loss for Na 4 EDTA was 34%. The compatibility and solubility of particulate Na 4 HEDP with/in NaOCl solutions are such that these components can be mixed and used for up to 1 hour. In contrast, short-term compatibility of the Na 4 EDTA salt with NaOCl solutions was considerably lower, decreasing at higher concentrations of either compound. Especially for Na 4 HEDP but also for Na 4 EDTA, the NaOCl had little effect on calcium complexation. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Integrated assessment, water resources, and science-policy communication

    International Nuclear Information System (INIS)

    Davies, E.G.R.; Akhtar, M.K.; McBean, G.A.; Simonovic, S.P.

    2009-01-01

    Traditional climate change modeling neglects the role of feedbacks between different components of society-biosphere-climate system. Yet, such interconnections are critical. This paper describes an alternative, Integrated Assessment (IA) model that focuses on feedbacks not only within individual elements of the society-biosphere-climate system, but also on their interconnections. The model replicates the relevant dynamics of nine components of the society-biosphere- climate system at the sectoral, or single-component, level: climate, carbon cycle, hydrological cycle, water demand, water quality, population, land use, energy and economy. The paper discusses the role of the model in science-policy dialogue. (author)

  20. Documenting Matured Science: The BACC-Type Assessment Reports

    Science.gov (United States)

    Reckermann, M.; Omstedt, A. T.

    2016-12-01

    The BACC-type reports (BALTEX and Baltic Earth Assessment of Climate Change for the Baltic Sea region, BACC 2008 and BACC II 2015) represent an approach to assessing and making available current knowledge on regional climate change and its regional impacts on the physical, biogeochemical and biological environment (ecosystems, socio-economic sphere). The BACC assessments have originated in the BALTEX scientific research community (now Baltic Earth) and are coordinated by the International Baltic Earth Secretariat. The assessments are produced by teams of scientists from the region, led by lead authors who recruit experts from relevant topics to contribute. The report of 2015 was compiled by a different group of authors as 2008 to warrant independence of personal opinions and bias. The process is not externally funded and completely based on published scientific evidence, and not biased by political or economic interest groups. The BACC-type reports aim to bring together consolidated knowledge that has broad consensus in the scientific community, but also acknowledging issues for which contradicting opinions are found in the literature, so that no consensus can be reached ("consensus on dissensus"). An international steering committee is responsible for overlooking the process, and all manuscripts are anonymously peer-reviewed by independent international experts. Outreach to stakeholders and the public is an inherent aspect of this approach to document mature science. For the Baltic Sea, there is a close collaboration with HELCOM, the intergovernmental Baltic Marine Environment Protection Commission and the major regional science-policy interface in the Baltic Sea region. A summary for non-scientists was produced for the first BACC report and is in preparation for the second. Other BACC-type reports published are the climate report for the greater Hamburg area (published in 2011), and the NOSCCA report (North Sea Climate Change Assessment), published in 2016.

  1. Radiation environmental impact assessment of the radioisotope's application on nuclear medical science

    International Nuclear Information System (INIS)

    Liu Hongshi

    2004-01-01

    The radiation environmental impact assessment of the radioisotope's application on nuclear medical science is introduced, including the assessment criteria, the assessment methods and the environmental impact assessment of three wastes emission. (authors)

  2. [Effectiveness of social mobilization and social marketing in promoting NaFeEDTA-fortified soya sauce in adult women].

    Science.gov (United States)

    Wang, Bo; Chen, Junshi; Zhan, Siyan; Sun, Jing; Li, Liming

    2011-05-01

    To assess the effectiveness of social mobilization and social marketing in promoting NaFeEDTA-fortified soy sauce in an iron deficient population. This study was an uncontrolled, community-based, before-after study, which was implemented in three counties of Shijiazhuang Municipality. The intervention was a social mobilization and social marketing strategy. Adult women older than 20 years of age participated in the evaluation protocol. The main outcomes included KAP relevant to IDA. Cross-sectional samples were used to assess the outcomes at baseline and 1 year later. Knowledge and attitudes of adult women had changed positively, and the percentage of women who had adopted NaFeEDTA-fortified soy sauce increased from 8.9% to 36.6% (P marketing had a positive impact on the KAP of adult women in the iron deficient population.

  3. Risk Assessment in the 21st Century | Science Inventory | US ...

    Science.gov (United States)

    For the past ~50 years, risk assessment depended almost exclusively on animal testing for hazard identification and dose-response assessment. Originally sound and effective, with increasing dependence on chemical tools and the number of chemicals in commerce, this traditional approach is no longer adequate. This presentation provides an update on current progress in achieving the goals outlined in the NAS report on Toxicology Testing in the 21st Century, highlighting many of the advances lead by the EPA. Topics covered include the evolution of the mode of action framework into a chemically agnostic, adverse outcome pathway (AOP), a systems-based data framework that facilitates integration of modifiable factors (e.g., genetic variation, life stages), and an understanding of networks, and mixtures. Further, the EDSP pivot is used to illustrate how AOPs drive development of predictive models for risk assessment based on assembly of high throughput assays representing AOP key elements. The birth of computational exposure science, capable of large-scale predictive exposure models, is reviewed. Although still in its infancy, development of non-targeted analysis to begin addressing exposome also is presented. Finally, the systems-based AEP is described that integrates exposure, toxicokinetics and AOPs into a comprehensive framework. For the past ~50 years, risk assessment depended almost exclusively on animal testing for hazard identification and dose-response as

  4. Experiences of Using Automated Assessment in Computer Science Courses

    Directory of Open Access Journals (Sweden)

    John English

    2015-10-01

    Full Text Available In this paper we discuss the use of automated assessment in a variety of computer science courses that have been taught at Israel Academic College by the authors. The course assignments were assessed entirely automatically using Checkpoint, a web-based automated assessment framework. The assignments all used free-text questions (where the students type in their own answers. Students were allowed to correct errors based on feedback provided by the system and resubmit their answers. A total of 141 students were surveyed to assess their opinions of this approach, and we analysed their responses. Analysis of the questionnaire showed a low correlation between questions, indicating the statistical independence of the individual questions. As a whole, student feedback on using Checkpoint was very positive, emphasizing the benefits of multiple attempts, impartial marking, and a quick turnaround time for submissions. Many students said that Checkpoint gave them confidence in learning and motivation to practise. Students also said that the detailed feedback that Checkpoint generated when their programs failed helped them understand their mistakes and how to correct them.

  5. In-EDTA as activable tracer in hydrogeological investigations

    International Nuclear Information System (INIS)

    Stanescu, S.P.; Gaspar, E.; Spiridon, S.; Farcasiu, O.M.; Catilina, R.

    1982-12-01

    Two experiments are presented, on the possibilities of the use of indium in the form of the In-EDTA complex, as an activable tracer for hydrogeological studies. The determination of indium concentrations in the sampled water has been carried out by using the coprecipitation of indium with bismuth hydroxide, the neutron activation at the VVR-S reactor of the Institute for Nuclear Physics and Engineering - Bucharest and the measurement on the 417.0 keV line of sup(116m)In with the Ge(Li) spectrometric device. The advantages of the utilization of In-EDTA as a tracer for marking large volumes of water and of some long transit waters (of the order of months) have resulted. (authors)

  6. Thermometric studies on the Fe(III)-EDTA chelate.

    Science.gov (United States)

    Dot, K

    1978-02-01

    A DeltaH of -11.5 +/- 0.5 kJ/mole has been determined for the formation of the Fe(III)-EDTA chelate at 25.0 degrees and mu = 0.1(= [HClO(4)] + [NaClO(4)]) by a direct thermometric titration procedure. The entropy change, DeltaS, has been calculated to be 440 J.mole(-1) .deg(-1) by combining the result of the heat measurements with the free energy change obtained from the stability constant previously determined. A relationship between the DeltaS values and the standard partial molal entropies of the tervalent metal ions is discussed. In addition, conditions for the thermometric titration of Fe(III) with NA(4)EDTA at room temperature have been investigated. Iron(III) can be determined in the presence of fairly large amounts of phosphate, Cr(III), Mn(II) and Al(III).

  7. Application of cerium(IV)/EDTA complex for future biotechnology

    International Nuclear Information System (INIS)

    Sumaoka, Jun; Chen Wen; Kitamura, Yoshihito; Tomita, Takafumi; Yoshida, Junya; Komiyama, Makoto

    2006-01-01

    A new artificial system for site-selective hydrolysis of single-stranded DNAs was prepared. By using two oligonucleotide additives that bear a monophosphate group at the termini, gap structures were formed at predetermined positions in substrate DNA. The phosphodiester linkages in the gap were efficiently and selectively hydrolyzed by Ce(IV)/EDTA complex (EDTA, ethylenediamine-N,N,N',N'-tetraacetate) at pH 7.0 and 37 deg. C. Furthermore, the fragments formed by the site-selective scission were connected with various oligonucleotides by using T4 DNA ligase, producing desired recombinant DNAs. A new tool for manipulation of single-stranded DNA in biotechnology has been successfully obtained

  8. Development and Exemplification of a Model for Teacher Assessment in Primary Science

    Science.gov (United States)

    Davies, D. J.; Earle, S.; McMahon, K.; Howe, A.; Collier, C.

    2017-01-01

    The Teacher Assessment in Primary Science project is funded by the Primary Science Teaching Trust and based at Bath Spa University. The study aims to develop a whole-school model of valid, reliable and manageable teacher assessment to inform practice and make a positive impact on primary-aged children's learning in science. The model is based on a…

  9. 76 FR 57762 - Agency Information Collection Activities: Proposed New Collection-Social Science Assessment and...

    Science.gov (United States)

    2011-09-16

    ... Information Collection Activities: Proposed New Collection--Social Science Assessment and Geographic Analysis...: OMB Control Number: 1024-NEW. Title: Social Science Assessment and Geographic Analysis of Marine... for Coastal Science and Policy, Mail Stop 250, Flanagan, East Carolina University, Greenville, NC...

  10. EDTA fouling in dead-end ultrafiltration of low level radioactive wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Lixia [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China); Zhang, Xue [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Zhao, Xuan, E-mail: zhxinet@mail.tsinghua.edu.cn [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Hu, Hongying [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China); State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China)

    2015-12-15

    Highlights: • EDTA in LLRW caused unrecoverable UF membrane fouling. • The rejection of nuclides by UF was significantly enhanced with EDTA addition. • The nuclide (except Ag) deposition on membrane increased with EDTA addition. • Reducing EDTA in the feed water or alkaline/ultrasonic washing were suggested. - Abstract: EDTA is widely used as a detergent, and finally enters into wastewater. The influence of EDTA on ultrafiltration of low level radioactive wastewater (LLRW) was investigated under different operation conditions. As the main organic pollutant, EDTA led to unrecoverable membrane fouling and the normalized flux decreased from 100% to 85% depending on its concentration. The clogging caused by EDTA increased the surface roughness of the membrane, leading to the flux reduction. Both nuclide rejections and depositions on the membrane surfaces were enhanced with EDTA addition, due to the strong complexation of the nuclides with EDTA. However, Ag deposition on the membrane decreased slightly in the presence of EDTA, which may be caused by the stronger attraction of Ag to the unmodified membrane than that to the EDTA-modified one. Transmembrane pressure (TMP) and molecular weight cut off (MWCO) of membranes had negligible effects on membrane fouling, while the nuclide rejections by membrane and the depositions of nuclides on membrane both decreased significantly when the TMP increased to 0.2 MPa and MWCO increased from 5 kDa to 30 kDa. Based on these results, it clearly showed that EDTA even at a low concentration had strong effects on the performance of UF treating LLRW. Therefore, it is suggested for industrial application that pretreatments to reduce EDTA or alkaline/ultrasonic washing involved in UF process were necessary to reduce the nuclide depositions on the membrane surfaces and irradiation dose of membrane surface.

  11. Radiopharmaceuticals of DTPA, DMSA and EDTA labeled with holmium-166

    International Nuclear Information System (INIS)

    Rahman, M.; Matsouka, H.; Takami, S.; Terunuma, K.

    2001-01-01

    DTPA, DMSA and EDTA were labelled with 166 Ho of low specific activity, 250-275mCi/mg of Ho, produced from holmium oxide by the 165 Ho(n, g) 166 Ho reaction at a neutron flux of about 10 14 n.cm -2 .s -1 . Three pH ranges were selected in the study, viz. 2-3, 3-3.5 and 5-6. The labelling reactions were studied as chloride and nitrate solutions in aqueous and saline media at 30 min and 20-24 h of reaction. DTPA was labelled over 99, DMSA at about 90 and EDTA at 100.0% with 166 Ho. The complexes were found stable at all times of investigation. A beta chromatogram scanner was used to study by TLC the labelling reactions of DTPA and DMSA with the nuclide and by PC those of EDTA. A biodistribution study in three rats injected intravenous with a saline solution of 166 HoCl 3 [DTPA] at pH5.1 showed an initial uptake in blood, kidney and lung after 30 minutes. After four hours the complex was found to have cleared from blood and lung, and localized 100% in kidney. It was stable in vivo in the kidney after 24 hours. The g spectrum analysis did not show the formation of any impurity except the four characteristic g energies of 166 Ho. (author)

  12. Simultaneous Removal of Thallium and EDTA by Fenton Process

    Science.gov (United States)

    Xu, Ruibing; Huang, Xuexia; Li, Huosheng; Su, Minhua; Chen, Diyun

    2018-01-01

    The wastewater containing heavy metals and organic pollutants is widely discharged from industries. Because of the coexistence of heavy metals and organic pollutants, the treatment of such wastewater is very difficult. Fenton process is considered to be one of the most effective approaches for the degradation of organic pollutants in aqueous solution due to the strong oxidative ability of hydroxyl radical which generated from the Fenton process. Apart from this, heavy metals are able to be removed during Fenton process owning to the synergic effect of coagulation and precipitation. In this work, pollutants of thallium and EDTA were successfully removed via the Fenton process. A series of single-factor experiments were designed and performed to achieve an optimal reaction conditions for the removal of both thallium and EDTA. Results showed that the removal efficiencies of thallium and TOC could be as high as 96.54% and 70.42%, respectively. The outcomes from our study demonstrate that Fenton process is a promising method for the purification of wastewater containing thallium and EDTA.

  13. The influence of EDDS and EDTA on the uptake of heavy metals of Cd and Cu from soil with tobacco Nicotiana tabacum.

    Science.gov (United States)

    Evangelou, Michael W H; Bauer, Uwe; Ebel, Mathias; Schaeffer, Andreas

    2007-06-01

    Phytoextraction, the use of plants to extract contaminants from soils and groundwater, is a promising approach for cleaning up soils contaminated with heavy metals. In order to enhance phytoextraction the use of chelating agents has been proposed. This study aims to assess whether ethylene diamine disuccinate (EDDS), a biodegradable chelator, can be used for enhanced phytoextraction purposed, as an alternative to ethylene diamine tetraacetate (EDTA). EDDS revealed a higher toxicity to tobacco (Nicotiana tabacum) in comparison to EDTA, but no toxicity to microorganisms. The uptake of Cu was increased by the addition of EDTA and EDDS, while no increase was observed in the uptake of Cd. Both chelating agents showed a very low root to shoot translocation capability and the translocation factor was lower than the one of the control. Heavy metals where significantly more phytoavailable than in the control, even after harvesting, resulting in a high heavy metal leaching possibility, probably owing to a low biodegradation rate of EDDS. New seedlings which were transplanted into the EDDS treated pots 7d after the phytoextraction experiment, showed signs of necrosis and chlorosis, which resulted in a significantly lower biomass in comparison to the control. The seedlings on the EDTA treated pots showed no toxicity signs. Contrary to previous opinions the results of this study revealed the chelating agents EDTA and EDDS as unsuitable for enhanced phytoextraction using tobacco.

  14. Family and Consumer Sciences Teacher Needs Assessment of a STEM-Enhanced Food and Nutrition Sciences Curriculum

    OpenAIRE

    Merrill, Cathy A.

    2016-01-01

    Science, technology, engineering and mathematics (STEM) education concepts are naturally contextualized in the study of food and nutrition. In 2014 a pilot group of Utah high school Career and Technical Education Family and Consumer Sciences teachers rewrote the Food and Nutrition Sciences curriculum to add and enhance the STEM-related content. This study is an online needs assessment by Utah Food and Nutrition 1 teachers on the implementation of the STEM-enhanced curriculum after its first y...

  15. Integrated Science Assessment (ISA) of Ozone and Related Photochemical Oxidants (Second External Review Draft, Sep 2011)

    Science.gov (United States)

    EPA has released the Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Second External Review Draft) for independent peer review and public review. This draft document represents a concise synthesis and evaluation of the most policy-relevant scienc...

  16. Nanotechnology in food science: Functionality, applicability, and safety assessment

    Directory of Open Access Journals (Sweden)

    Xiaojia He

    2016-10-01

    Full Text Available Rapid development of nanotechnology is expected to transform many areas of food science and food industry with increasing investment and market share. In this article, current applications of nanotechnology in food systems are briefly reviewed. Functionality and applicability of food-related nanotechnology are highlighted in order to provide a comprehensive view on the development and safety assessment of nanotechnology in the food industry. While food nanotechnology offers great potential benefits, there are emerging concerns arising from its novel physicochemical properties. Therefore, the safety concerns and regulatory policies on its manufacturing, processing, packaging, and consumption are briefly addressed. At the end of this article, the perspectives of nanotechnology in active and intelligent packaging applications are highlighted.

  17. Nanotechnology in food science: Functionality, applicability, and safety assessment.

    Science.gov (United States)

    He, Xiaojia; Hwang, Huey-Min

    2016-10-01

    Rapid development of nanotechnology is expected to transform many areas of food science and food industry with increasing investment and market share. In this article, current applications of nanotechnology in food systems are briefly reviewed. Functionality and applicability of food-related nanotechnology are highlighted in order to provide a comprehensive view on the development and safety assessment of nanotechnology in the food industry. While food nanotechnology offers great potential benefits, there are emerging concerns arising from its novel physicochemical properties. Therefore, the safety concerns and regulatory policies on its manufacturing, processing, packaging, and consumption are briefly addressed. At the end of this article, the perspectives of nanotechnology in active and intelligent packaging applications are highlighted. Copyright © 2016. Published by Elsevier B.V.

  18. Long-term risks of kidney living donation: review and position paper by the ERA-EDTA DESCARTES working group.

    Science.gov (United States)

    Maggiore, Umberto; Budde, Klemens; Heemann, Uwe; Hilbrands, Luuk; Oberbauer, Rainer; Oniscu, Gabriel C; Pascual, Julio; Schwartz Sorensen, Soren; Viklicky, Ondrej; Abramowicz, Daniel

    2017-02-01

    Two recent matched cohort studies from the USA and Norway published in 2014 have raised some concerns related to the long-term safety of kidney living donation. Further studies on the long-term risks of living donation have since been published. In this position paper, Developing Education Science and Care for Renal Transplantation in European States (DESCARTES) board members critically review the literature in an effort to summarize the current knowledge concerning long-term risks of kidney living donation to help physicians for decision-making purposes and for providing information to the prospective live donors. Long-term risk of end-stage renal disease (ESRD) can be partially foreseen by trying to identify donors at risk of developing ‘de novo’ kidney diseases during life post-donation and by predicting lifetime ESRD risk. However, lifetime risk may be difficult to assess in young donors, especially in those having first-degree relatives with ESRD. The study from Norway also found an increased risk of death after living donor nephrectomy, which became visible only after >15 years of post-donation follow-up. However, these findings are likely to be largely the result of an overestimation due to the confounding effect related to a family history of renal disease. DESCARTES board members emphasize the importance of optimal risk–benefit assessment and proper information to the prospective donor, which should also include recommendations on health-promoting behaviour post-donation. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  19. Ground Validation Assessments of GPM Core Observatory Science Requirements

    Science.gov (United States)

    Petersen, Walt; Huffman, George; Kidd, Chris; Skofronick-Jackson, Gail

    2017-04-01

    NASA Global Precipitation Measurement (GPM) Mission science requirements define specific measurement error standards for retrieved precipitation parameters such as rain rate, raindrop size distribution, and falling snow detection on instantaneous temporal scales and spatial resolutions ranging from effective instrument fields of view [FOV], to grid scales of 50 km x 50 km. Quantitative evaluation of these requirements intrinsically relies on GPM precipitation retrieval algorithm performance in myriad precipitation regimes (and hence, assumptions related to physics) and on the quality of ground-validation (GV) data being used to assess the satellite products. We will review GPM GV products, their quality, and their application to assessing GPM science requirements, interleaving measurement and precipitation physical considerations applicable to the approaches used. Core GV data products used to assess GPM satellite products include 1) two minute and 30-minute rain gauge bias-adjusted radar rain rate products and precipitation types (rain/snow) adapted/modified from the NOAA/OU multi-radar multi-sensor (MRMS) product over the continental U.S.; 2) Polarimetric radar estimates of rain rate over the ocean collected using the K-Pol radar at Kwajalein Atoll in the Marshall Islands and the Middleton Island WSR-88D radar located in the Gulf of Alaska; and 3) Multi-regime, field campaign and site-specific disdrometer-measured rain/snow size distribution (DSD), phase and fallspeed information used to derive polarimetric radar-based DSD retrievals and snow water equivalent rates (SWER) for comparison to coincident GPM-estimated DSD and precipitation rates/types, respectively. Within the limits of GV-product uncertainty we demonstrate that the GPM Core satellite meets its basic mission science requirements for a variety of precipitation regimes. For the liquid phase, we find that GPM radar-based products are particularly successful in meeting bias and random error requirements

  20. Direct analysis of ethylenediaminetetraacetic acid (EDTA) on concrete by reactive-desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Lebeau, D; Reiller, P E; Lamouroux, C

    2015-01-01

    Analysis of organic ligands such as ethylenediaminetetraacetic acid (EDTA) is today an important challenge due to their ability to increase the mobility of radionuclides and metals. Reactive desorption electrospray ionization mass spectrometry (reactive-DESI-MS) was used for direct analysis of EDTA on concrete samples. EDTA forms complexes and those with Fe(III) ions are among the most thermodynamically favored. This complexing capacity was used to improve the specific detection of EDTA directly on a concrete matrix by doping the solvent spray of DESI with a solution of FeCl3 to selectively create the complex between EDTA and Fe(III). Thus, EDTA sensitivity was largely improved by two orders of magnitude with reactive-DESI-MS experiments thanks to the specific detection of EDTA as a [EDTA-4H+Fe(III)](-) complex. The proof of principle that reactive DESI can be applied to concrete samples to detect EDTA has been demonstrated. Its capacity for semi-quantitative determination and localization of EDTA under ambient conditions and with very little sample preparation, minimizing sample manipulations and solvent volumes, two important conditions for the development of new methodologies in the field of analytical chemistry, has been shown. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Development and Validation of an Online Dynamic Assessment for Raising Students' Comprehension of Science Text

    Science.gov (United States)

    Wang, Jing-Ru; Chen, Shin-Feng

    2016-01-01

    This article reports on the development of an online dynamic approach for assessing and improving students' reading comprehension of science texts--the dynamic assessment for reading comprehension of science text (DARCST). The DARCST blended assessment and response-specific instruction into a holistic learning task for grades 5 and 6 students. The…

  2. Phytoremediation of lead by jack beans on a Rhodic Hapludox amended with EDTA Fitorremediação de chumbo por feijão-de-porco em um Latossolo Vermelho Distrófico tratado com EDTA

    Directory of Open Access Journals (Sweden)

    Bruno Fernando Faria Pereira

    2010-01-01

    Full Text Available A greenhouse study was conducted to evaluate the effects of ethylenediamine tetraacetic acid (EDTA addition to soils on the lead (Pb phytoextraction potential of jack beans (Canavalia ensiformis L.. In a pot experimentSoil samples (dystrophic Rhodic Hapludox were treated with six Pb rates (0, 100, 200, 350, 1,200, and 2,400 mg kg-1 soil applied as Pb(NO32 without and with EDTA application (0 and 0.5 g kg-1, respectively. Lead, Cl-, NO3-, NH4+, SO4(2-, H2PO4-, Zn2+, Cu2+, Fe3+, Al3+, Ca2+, Mg2+, K+ and DOC (dissolved organic carbon concentrations obtained in a saturation soil extract (soil:water ratio of 1:0.3 were used for Pb speciation by means of the software Visual-Minteq 2.30. Soil Pb-availability was assessed with Diethylene triamine pentaacetic acid (DTPA extraction. EDTA treated soils showed higher Pb (as PbEDTA2-, and Fe (as FeEDTA- concentrations in soil solution leading to higher uptake of these elements by the jack bean. On the other hand, it decreased the concentration of stable complexes as Pb-DOC and Fe-DOC. EDTA also induced better nutrition to plants building up the concentration of non target metals (Ca, K, Mg, Zn, Cu, Fe and Mn in shoots. Shoot dry matter yield remained constant even at the highest Pb rates after EDTA treatment. Jack bean can be considered as a potential Pb-phytoextractor. In addition, the DTPA solution was effective to assess Pb availability to the plants at all applied Pb rates.Este estudo teve como objetivo avaliar, em condições de casa de vegetação, os efeitos do ácido etilenodiamino tetraacético (EDTA no potencial fitoextrator do feijão-de-porco (Canavalia ensiformis L.. Amostras de um Latossolo Vermelho distrófico foram tratadas com seis doses de Pb (0, 100, 200, 350, 1.200 e 2.400 mg kg-1 de solo aplicadas como Pb(NO32 com e sem a aplicação de EDTA (0 e 0,5 g kg-1, respectivamente e colocadas em vasos. A concentração de Pb2+, Cl-, NO3-, NH4+, SO4(2-, H2PO4-, Zn2+, Cu2+, Fe3+, Al3+, Ca2+, Mg2

  3. Mission Adaptive UAS Platform for Earth Science Resource Assessment

    Science.gov (United States)

    Dunagan, S.; Fladeland, M.; Ippolito, C.; Knudson, M.

    2015-01-01

    NASA Ames Research Center has led a number of important Earth science remote sensing missions including several directed at the assessment of natural resources. A key asset for accessing high risk airspace has been the 180 kg class SIERRA UAS platform, providing mission durations of up to 8 hrs at altitudes up to 3 km. Recent improvements to this mission capability are embodied in the incipient SIERRA-B variant. Two resource mapping problems having unusual mission characteristics requiring a mission adaptive capability are explored here. One example involves the requirement for careful control over solar angle geometry for passive reflectance measurements. This challenges the management of resources in the coastal ocean where solar angle combines with sea state to produce surface glint that can obscure the ocean color signal. Furthermore, as for all scanning imager applications, the primary flight control priority to fly the UAS directly to the next waypoint should compromise with the requirement to minimize roll and crab effects in the imagery. A second example involves the mapping of natural resources in the Earth's crust using precision magnetometry. In this case the vehicle flight path must be oriented to optimize magnetic flux gradients over a spatial domain having continually emerging features, while optimizing the efficiency of the spatial mapping task. These requirements were highlighted in several recent Earth Science missions including the October 2013 OCEANIA mission directed at improving the capability for hyperspectral reflectance measurements in the coastal ocean, and the Surprise Valley Mission directed at mapping sub-surface mineral composition and faults, using high-sensitivity magentometry. This paper reports the development of specific aircraft control approaches to incorporate the unusual and demanding requirements to manage solar angle, aircraft attitude and flight path orientation, and efficient (directly geo-rectified) surface and sub

  4. The effect of media composition on EDTA degradation by Agrobacterium sp

    International Nuclear Information System (INIS)

    Palumbo, A.V.; Lee, S.Y.; Boerman, P.

    1994-01-01

    EDTA degradation by an Agrobacterium sp. has been examined by quantifying 14 C-labeled CO 2 produced from iron-[2- 14 C] EDTA and by measured loss of nonlabeled EDTA by HPLC. Fe-EDTA degradation resulted in a rise in pH, nitrate concentration, and ammonia concentration. Addition of glycerol resulted in suppression of Fe-EDTA degradation and in a decrease in pH and NH 4 + concentration in the media. Addition of peptone or yeast extract did not affect degradation. Some of the components (e.g., biotin) of the media are not necessary for growth and biodegradation. Although cobalt-EDTA cannot be degraded, ferrous iron can be added to displace the cobalt. The purpose was to relate the results to remediation of radionuclide-contaminated soils. 12 refs., 4 figs., 2 tabs

  5. Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

    Science.gov (United States)

    Dotto, Sidney Ricardo; Travassos, Rosana Maria Coelho; de Oliveira, Elias Pandonor Motcy; Machado, Manoel Eduardo de Lima; Martins, José Luiz

    2007-08-01

    The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

  6. Recovery of manganese from manganese oxide ores in the EDTA solution

    Science.gov (United States)

    Zhang, Chao; Wang, Shuai; Cao, Zhan-fang; Zhong, Hong

    2018-04-01

    A new process has been experimentally and theoretically established for the recovery of manganese from manganese oxide ores, mainly including the reductive leaching of manganese by ethylenediaminetetraacetic acid (EDTA), EDTA recovery, and manganese electrolysis. The experimental conditions for this process were investigated. Moderate leaching environment by EDTA with the pH in the range of 5-6 is of benefit to leach manganese from some manganese oxide ores with high-content impurities, such as iron and aluminum. Most of EDTA can be recovered by acidification. A small amount of the residual EDTA in the electrolyte can prevent the generation of anode mud. In addition, trimanganese tetroxide (Mn3O4) can be obtained by the roasting of the EDTA-Mn crystallized product.

  7. Ion exchange behaviour of citrate and EDTA anions on strong and weak base organic ion exchangers

    International Nuclear Information System (INIS)

    Askarieh, M.M.; White, D.A.

    1988-01-01

    The exchange of citrate and EDTA ions with two strong base and two weak base exchangers is considered. Citrate and EDTA analysis for this work was performed using a colorimetric method developed here. The ions most selectively exchanged on the resins are H 2 cit - and H 2 EDTA 2- , though EDTA is generally less strongly sorbed on strong base resins. In contact with weak base resins, deprotonation of the resin occurs during ion exchange with a noticeable drop in solution pH. Although EDTA sorption can be reversed by nitric acid, citrate ions are significantly held on the resin at low pH. The exchange of citrate can be made reversible if bicarbonate is added to the initial solutions. Alkaline regeneration of exchangers loaded with EDTA proved to be very effective. (author)

  8. The Use of Clinical Interviews to Develop Inservice Secondary Science Teachers' Nature of Science Knowledge and Assessment of Student Nature of Science Knowledge

    Science.gov (United States)

    Peters-Burton, Erin E.

    2013-01-01

    To fully incorporate nature of science knowledge into classrooms, teachers must be both proficient in their own nature of science knowledge, but also skillful in translating their knowledge into a learning environment which assesses student knowledge. Twenty-eight inservice teachers enrolled in a graduate course which in part required a clinical…

  9. Oxidative dehydrogenation of the 2-aminomethylpyridine (EDTA) ruthenium (III) complex

    International Nuclear Information System (INIS)

    Toma, H.E.; Tsurumaki, M.

    1990-01-01

    The oxidative dehydrogenation of the 2-aminomethylpyridine (ampy) ligand coordinated to the (EDTA)RU(III) complex was investigated based on cyclic voltammetry, spectoelectrochemistry and stopped-flow kinetic measurements in aqueous solution. The reaction mechanism is consistent with the deprotonation of the ampy ligand (pk a =7.48), followed by a reversible one-electron transfer step. The intermediate species generated at this step undergoes a metal-induced electron transfer process, with k=227 s -1 , converting into the corresponding 2-iminomethylpyridine complex. (author) [pt

  10. Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

    1954-01-01

    The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

  11. [51Cr]EDTA plasma clearance and endogenous creatinine clearance in advanced renal insufficiency

    International Nuclear Information System (INIS)

    Svendsen, U.G.; Munck, O.; Czartoryski, A.; Stafanger, G.

    1978-01-01

    Comparison of [ 51 Cr]EDTA plasma clearance corrected for extrarenal elimination with 24 h endogenous creatinine clearance in patients with advanced renal failure showed that the corrected [ 51 Cr]EDTA clearance was lower than creatinine clearance, and thus might be a better approximation to the glomerular filtration rate in uraemic patients. The corrections cannot be used on [ 51 Cr]EDTA clearance values below the mean extrarenal clearance, averaging 3.7 ml/min. (Auth.)

  12. In vitro comparison of different 24% EDTA gel formulations efficacy on root surface conditioning

    OpenAIRE

    Sousa, Cliciane Portela; Frizzera, Fausto; Batista, Luiz Henrique Carvalho; Dantas, Andrea Abi Rached; Zandim-Barcelos, Daniela Leal; Sampaio, José Eduardo Cezar

    2013-01-01

    INTRODUCTION: The main goal of root biomodification is to modify the root surface in order to improve the repair of periodontal tissues destroyed by periodontal disease. OBJECTIVE: To evaluate the conditioning efficacy of 24% EDTA gel of different trademarks, considering the variables time and application method, by scanning electron microscopy. MATERIAL AND METHOD: 225 samples were randomly assigned to five groups: sterile saline solution (control); 24% EDTA (Santa Paula Pharmacy); 24% EDTA-...

  13. Teratogenic effect of calcium edetate (CaEDTA) in rats and the protective effect of zinc.

    Science.gov (United States)

    Brownie, C F; Brownie, C; Noden, D; Krook, L; Haluska, M; Aronson, A L

    1986-03-15

    The calcium chelate of EDTA (CaEDTA) currently is the drug of choice in the treatment of lead intoxication. This study investigated the teratogenic potential of CaEDTA, administered parenterally during periods of organogenesis and determined if incorporating zinc into EDTA would protect against teratogenic effects. Four doses (2, 4, 6, and 8 mmol/m2/day) of CaEDTA, two concentrations (8 and 20 mmol/m2/day) of ZnEDTA and ZnCaEDTA (molar ratio 0.5:0.5:1) were used, and a saline control (0.9% NaCl). Timed-pregnant Long-Evans rats were assigned at random to the treatment groups, 20 per dose for each chelate and 30 to the saline control. Rats were injected with the chelate or saline solution sc, twice daily during the 11th through 15th days of gestation. Pups removed by cesarean section on the 21st day were processed for osseous and visceral examination. Additional animals per treatment group were used for maternal plasma and liver and fetal zinc determinations. Results showed increases in several abnormalities (submucous cleft, cleft palate, adactyly-syndactyly, curly tail, abnormal rib and vertebrae) with increasing amounts of CaEDTA. No malformations were seen with ZnEDTA at either dose or with ZnCaEDTA at 8 mmol/m2/day. However, submucous cleft was seen in 6 of 20 litters from the dams receiving the higher dose of ZnCaEDTA. It was concluded that CaEDTA is teratogenic in rats at concentrations which, except for decreased weight gain, produce no discernible toxicity to the dam, and which are comparable to the recommended therapeutic dosage in humans (1500 mg/m2/day corresponding to 4 mmol/m2/day). Protection is afforded by incorporating zinc in the chelate.

  14. Visual Representations on High School Biology, Chemistry, Earth Science, and Physics Assessments

    Science.gov (United States)

    LaDue, Nicole D.; Libarkin, Julie C.; Thomas, Stephen R.

    2015-01-01

    The pervasive use of visual representations in textbooks, curricula, and assessments underscores their importance in K-12 science education. For example, visual representations figure prominently in the recent publication of the Next Generation Science Standards (NGSS Lead States in Next generation science standards: for states, by states.…

  15. Comparison between high concentration EDTA (24%) and low concentration EDTA (3%) with surfactant upon removal of smear layer after rotary instrumentation: a SEM study.

    Science.gov (United States)

    Daghustani, Mohsen; Alhammadi, Ahmad; Merdad, Khalid; Ohlin, Johan; Erhardt, Fredrik; Ahlquist, Michael

    2011-01-01

    This in vitro study compare cleanliness of tooth canal walls regarding smear layer after final treatment with 24% ethylenediaminetetraaceticacid (EDTA) and 3% EDTA with or without surfactant. Sixty extracted teeth, randomly distributed into four groups, were prepared using ProFile instruments (DENTSPLY, Maillefer, Ballaigues, Switzerland), and subjected to different final irrigation solutions: group A, 24% EDTA; group B, 3% EDTA with surfactant; group C (positive control), 3% EDTA; and group D (negative control), 0.5% sodium hypochlorite. Roots were sectioned, examined and evaluated under scanning electron microscope; microphotographs were taken for the coronal, middle and apical third of each specimen. Statistical analysis showed no difference regarding presence of smear layer between test groups in the coronal and apical sections. They were cleaned in the coronal sections and uncleaned in the apical sections. In the middle section, group B was significantly cleaner (p EDTA did not improve root canal cleanliness and there is no difference between different EDTA concentrations in removing the smear layer.

  16. Scientific Caricatures in the Earth Science Classroom: An Alternative Assessment for Meaningful Science Learning

    Science.gov (United States)

    Clary, Renee M.; Wandersee, James H.

    2010-01-01

    Archive-based, historical research of materials produced during the Golden Age of Geology (1788-1840) uncovered scientific caricatures (SCs) which may serve as a unique form of knowledge representation for students today. SCs played important roles in the past, stimulating critical inquiry among early geologists and fueling debates that addressed key theoretical issues. When historical SCs were utilized in a large-enrollment college Earth History course, student response was positive. Therefore, we offered SCs as an optional assessment tool. Paired t-tests that compared individual students’ performances with the SC option, as well as without the SC option, showed a significant positive difference favoring scientific caricatures ( α = 0.05). Content analysis of anonymous student survey responses revealed three consistent findings: (a) students enjoyed expressing science content correctly but creatively through SCs, (b) development of SCs required deeper knowledge integration and understanding of the content than conventional test items, and (c) students appreciated having SC item options on their examinations, whether or not they took advantage of them. We think that incorporation of SCs during assessment may effectively expand the variety of methods for probing understanding, thereby increasing the mode validity of current geoscience tests.

  17. Heavy metal phytoextraction-natural and EDTA-assisted remediation of contaminated calcareous soils by sorghum and oat.

    Science.gov (United States)

    Mahmood-Ul-Hassan, Muhammad; Suthar, Vishandas; Ahmad, Rizwan; Yousra, Munazza

    2017-10-30

    The abilities of sorghum (Sorghum bicolor L.) and oat (Avena sativa L.) to take up heavy metals from soils amended with ethylenediaminetetraacetic acid (EDTA) were assessed under greenhouse conditions. Both plants were grown in two soils contaminated with heavy metals (Gujranwala-silty loam and Pacca-clay loam). The soils were treated with 0, 0.625, 1.25, and 2.5 mM EDTA kg -1 soil applied at both 45 and 60 days after sowing (DAS); the experiment was terminated at 75 DAS. Addition of EDTA significantly increased concentrations of Cd, Cr, and Pb in roots and shoots, and bio-concentration factors and phytoextraction rates were also increased. Post-harvest soil analysis showed that soluble fractions of metals were also increased significantly. The increase in Cd was ≈ 3-fold and Pb was ≈ 15-fold at the highest addition of EDTA in Gujranwala soil; in the Pacca soil, the increase was less. Similarly, other phytoremediation factors, such as metal translocation, bio-concentration factor, and phytoextraction, efficiency were also maximum when soils were treated with 2.5 mM EDTA kg -1 soil. The study demonstrated that sorghum was better than oat for phytoremediation.

  18. EDTA sample contamination is common and often undetected, putting patients at unnecessary risk of harm.

    Science.gov (United States)

    Sharratt, C L; Gilbert, C J; Cornes, M C; Ford, C; Gama, R

    2009-08-01

    Potassium ethylenediaminetetraacetic acid (EDTA) is a sample tube anticoagulant used for many laboratory analyses. Gross potassium EDTA contamination of blood samples is easily recognised by marked hyperkalaemia and hypocalcaemia. However, subtle contamination is a relatively common, often unrecognised erroneous cause of spurious hyperkalaemia. Potassium EDTA contamination may also cause hypomagnesaemia and hypozincaemia. There are, however, no data on the prevalence of EDTA contamination as a cause of hypocalcaemia, hypomagnesaemia and hypozincaemia. Following a recent service evaluation, we measure EDTA in serum samples from patients with unexplained hyperkalaemia (serum potassium > 6.0 mmol/l). In addition, over a 1-month period EDTA concentrations were measured in hypocalcaemic (serum adjusted calcium samples. Ethylenediaminetetraacetic acid contamination was detected in 31 samples, nine of which were detected by our routine screening programme. The remaining 22 samples represented 14.3% (19/133) of hypocalcaemic samples, 4.8% (5/104) of hypomagnesaemic samples and 1.4% (2/139) of hypozincaemic samples. A total of 25/31 (80.6%) of patients were re-bled, of which 23/25 (92%) results normalised. Factitious hyperkalaemia, hypocalcaemia and hypomagnesaemia caused by potassium EDTA contamination in our studies are relatively common, and if unrecognised may adversely affect patient care and waste scarce healthcare resources. Correct order of draw of blood samples, improved education and routine laboratory screening of EDTA are necessary to prevent and identify EDTA contamination.

  19. Effects of Application of NTA and EDTA on Accumulation of Soil Heavy Metals in Chrysanthemum

    Science.gov (United States)

    Bai, Weiyang

    2018-02-01

    In order to find out the effect of non-bio chelating agent EDTA and bio-chelating agent NTA on soil heavy metal pollution, the effects of different ratio of chelating agent NTA and EDTA on soil heavy metals (Pb, Cu and Cd ), the effects of chelating on content of chlorophyll and vitamin C and the degree of soil nutrient loss were evaluated. The results showed: that the contents of Pb and Cd were the highest in the roots of Chrysanthemum in the treatment (EDTA / NTA = 2: 1). The treatment (EDTA / NTA = 1: 1) was the best chelating agent ratio for the synergistic effect, which can significantly promoted the Chrysanthemum on heavy metal Cu uptake and transport to aboveground. Chrysanthemum were inhibited by all chelating agents treatments, while the content of chlorophyll and vitamin C of the Chrysanthemum physiological indexes were reduced. In the treatment (EDTA = 1), chlorophyll SPAD, vitamin C content reached a minimum of 36 and 38mg · 100g-1, respectively. The nutrient element TN in the leachate were gradually decreased with the time, and the tenth day was significantly lower than the leaching rate of the first day (p treatment (EDTA = 1) >treatment (EDTA / NTA = 2: 1) >treatment (EDTA / NTA = 1: 2)> treatment (NTA = 1). Treatment (EDTA / NTA = 2: 1) was recommended for the chelating agent ratio with the better physiological parameters, the more heavy metal extraction and the less nitrogen and phosphorus loss

  20. Ion chromatographic determination of vanadium (4) and vanadium (5) in the form of EDTA complexes

    International Nuclear Information System (INIS)

    Komarova, T.V.; Obrezkov, O.N.; Shpigun, O.A.

    1991-01-01

    Ion chromatographic behaviour of V 4+ and V 5+ -EDTA complexes (1,2) and V 5+ -EDTA monoperoxo complexes (3) has been studied. The regularities of ion exchange are obeyed for 1 and 3 complexes. These complex anions are strongly retained on HIX-1 anion exchanger. The chromatographic characteristics of 2 change in time, therefore its determination is impossible under the conditions studied. A method has been developed of the simultaneous determination of V 4+ and V 5+ which is based on retarded formation of the V 5+ -EDTA monoperoxo complex in a system of V 4+ -EDTA - H 2 O 2

  1. Electrochemical EDTA recycling with sacrificial Al anode for remediation of Pb contaminated soil

    International Nuclear Information System (INIS)

    Pociecha, Maja; Lestan, Domen

    2010-01-01

    Recycling chelant is a precondition for cost-effective EDTA-based soil remediation. Extraction with EDTA removed 67.5% of Pb from the contaminated soil and yielded washing solution with 1535 mg L -1 Pb and 33.4 mM EDTA. Electrochemical treatment of the washing solution using Al anode, current density 96 mA cm -2 and pH 10 removed 90% of Pb from the solution (by electrodeposition on the stainless steel cathode) while the concentration of EDTA in the treated solution remained the same. The obtained data indicate that the Pb in the EDTA complex was replaced by electro-corroded Al after electro-reduction of the EDTA and subsequently removed from the solution. Additional soil extraction with the treated washing solution resulted in total removal of 87% of Pb from the contaminated soil. The recycled EDTA retained the Pb extraction potential through several steps of soil extraction and washing solution treatment, although part of the EDTA was lost by soil absorption. - Aluminium anode at alkaline pH in conventional electrolytic cell enables efficient recycling of EDTA as a part of soil washing remediation technology.

  2. Japanese technology assessment: Computer science, opto- and microelectronics mechatronics, biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Brandin, D.; Wieder, H.; Spicer, W.; Nevins, J.; Oxender, D.

    1986-01-01

    The series studies Japanese research and development in four high-technology areas - computer science, opto and microelectronics, mechatronics (a term created by the Japanese to describe the union of mechanical and electronic engineering to produce the next generation of machines, robots, and the like), and biotechnology. The evaluations were conducted by panels of U.S. scientists - chosen from academia, government, and industry - actively involved in research in areas of expertise. The studies were prepared for the purpose of aiding the U.S. response to Japan's technological challenge. The main focus of the assessments is on the current status and long-term direction and emphasis of Japanese research and development. Other aspects covered include evolution of the state of the art; identification of Japanese researchers, R and D organizations, and resources; and comparative U.S. efforts. The general time frame of the studies corresponds to future industrial applications and potential commercial impacts spanning approximately the next two decades.

  3. Efeito do EDTA e EDTA-T aplicado de forma ativa na remoção de "smear layer" de superfícies radiculares

    OpenAIRE

    Sampaio, José Eduardo Cezar; Rached, Ricardo Samih Georges Abi; Pilatti, Gibson Luiz; Theodoro, Letícia Helena; Batista, Luiz Henrique Carvalho

    2003-01-01

    The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon) gel in different concentrations (5%, 10%, 15%, 20% and 24%), using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control) application of saline solution (n = 20); Group II - EDTA gel (pH 7.0) was applied in the following concentrations: 5%, 10%, 15%, ...

  4. Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable-isotope study in Kenyan infants.

    Science.gov (United States)

    Paganini, Daniela; Uyoga, Mary A; Cercamondi, Colin I; Moretti, Diego; Mwasi, Edith; Schwab, Clarissa; Bechtler, Salome; Mutuku, Francis M; Galetti, Valeria; Lacroix, Christophe; Karanja, Simon; Zimmermann, Michael B

    2017-10-01

    Background: Whether consumption of prebiotics increases iron absorption in infants is unclear. Objective: We set out to determine whether prebiotic consumption affects iron absorption from a micronutrient powder (MNP) containing a mixture of ferrous fumarate and sodium iron EDTA (FeFum+NaFeEDTA) in Kenyan infants. Design: Infants ( n = 50; aged 6-14 mo) consumed maize porridge that was fortified with an MNP containing FeFum+NaFeEDTA and 7.5 g galacto-oligosaccharides (GOSs) (Fe+GOS group, n = 22) or the same MNP without GOSs (Fe group, n = 28) each day for 3 wk. Then, on 2 consecutive days, we fed all infants isotopically labeled maize porridge and MNP test meals containing 5 mg Fe as 57 FeFum+Na 58 FeEDTA or ferrous sulfate ( 54 FeSO 4 ). Iron absorption was measured as the erythrocyte incorporation of stable isotopes. Iron markers, fecal pH, and bacterial groups were assessed at baseline and 3 wk. Comparisons within and between groups were done with the use of mixed-effects models. Results: There was a significant group-by-compound interaction on iron absorption ( P = 0.011). The median percentages of fractional iron absorption from FeFum+NaFeEDTA and from FeSO 4 in the Fe group were 11.6% (IQR: 6.9-19.9%) and 20.3% (IQR: 14.2-25.7%), respectively, ( P iron absorption was greater from the FeFum+NaFeEDTA ( P = 0.047) in the Fe+GOS group but not from the FeSO 4 ( P = 0.653). The relative iron bioavailability from FeFum+NaFeEDTA compared with FeSO 4 was higher in the Fe+GOS group than in the Fe group (88% compared with 63%; P = 0.006). There was a significant time-by-group interaction on Bifidobacterium spp. ( P = 0.008) and Lactobacillus / Pediococcus / Leuconostoc spp. ( P = 0.018); Lactobacillus / Pediococcus / Leuconostoc spp. decreased in the Fe group ( P = 0.013), and there was a nonsignificant trend toward higher Bifidobacterium spp. in the Fe+GOS group ( P = 0.099). At 3 wk, iron absorption was negatively correlated with fecal pH ( P iron absorption by 62

  5. Investigation of science production in Iran’s type I universities of medical sciences, a 6-year assessment

    Directory of Open Access Journals (Sweden)

    M Yadollahi

    2014-07-01

    Full Text Available Introduction: Science production is one of the main dimensions of sustainable development in any country. Thus, universities as the major centers for science production play a key role in development. The present study aimed to assess the trend of science production in Iran’s type I universities of medical sciences from 2007 to 2012. Method: In this study, the universities’ scores of empowering, governance and leadership, science production, student researches, and number of published articles were computed based on the evaluations of universities of medical sciences by the Ministry of Health, Treatment, and Medical Education from 2007 to 2012. Then, the data were analyzed using descriptive statistics and the figures were drawn by Excel software. Results: This study assessed science production in Iran’s type I universities of medical sciences and analyzed each university’s proportion in publication of articles. According to the results, most of the published articles were affiliated to Tehran University of Medical Sciences. However, considering the role of number of faculty members, different results were obtained. With respect to the evaluation raw scores, Isfahan University of Medical Sciences showed a considerable reduction of scores in 2012, while other universities had a constant or ascending trend. Besides, indexed articles followed an ascending trend in all the universities and most of the articles had been published in index 1. Conclusion: Similar to other studies, the findings of this study revealed an increase in science productions in Iran through the recent years. Yet, the highest scores of the studied indexes, except for student researches, were related to Tehran University of Medical Sciences. This great difference between this university and other universities might be due to accumulation of specific potentials and forces in this region. Overall, science productions followed an ascending trend in all type I universities of

  6. [Evaluation of initial results of treatment of lead poisoning with EDTA].

    Science.gov (United States)

    Petkova, V; Adjarov, D; Pavlova, S; Naydenova, E; Kerimova, M; Kuneva, T

    1994-01-01

    The results of EDTA therapy were studied in 37 workers of a battery factory consisting of males with varying degrees of occupational lead poisoning (low exposure: 10 subjects, blood lead levels (PbB) lower than 400 micrograms/l with slight alterations in heme biosynthesis; beyond limit of effect: 5 subjects, PbB > 400 micrograms/l; slight intoxication: 19 subjects, with marked alterations in heme synthesis and preclinical signs of intoxication; average degree of intoxication: 3 subjects with clinical signs of intoxication. Clinical symptoms and the following parameters were investigated: blood lead (PbB), delta-aminolevulinic acid dehydratase in erythrocytes (ALA-D), zinc protoporphyrin (PP) in erythrocytes and delta-aminolevulinic acid (ALA) in 24-hour urine before and after EDTA chelating therapy. Simultaneous measurement of ALA-D and PP showed high diagnostic sensitivity in detecting lead poisoning in occupationally exposed subjects. In view of the high interindividual variability of the results, these indices did not, however, permit a useful differentiation to be made of the different degrees of intoxication at individual level, even though a good correlation was observed between PbB and porphyrin metabolism indices. From the alterations observed in ALA-D and PP values it was not possible to establish an association between degree of alteration and types of clinical symptoms in the different intoxication studies. At the end of EDTA treatment, a clinical improvement was observed in all cases studied but only in 5 cases was a reduction in PbB observed, to levels below 1.20 mol/l, which is accepted as a permissible limit for the general population; in 17 cases PbB remained at levels above the critical value for occupational lead poisoning (400 micrograms/l), although there was a decrease after treatment. The improvement observed in the indices of porphyrin metabolism at the end of treatment was only slight: significant variations were measured only for PbB. After

  7. Simulation-Based Performance Assessment: An Innovative Approach to Exploring Understanding of Physical Science Concepts

    Science.gov (United States)

    Gale, Jessica; Wind, Stefanie; Koval, Jayma; Dagosta, Joseph; Ryan, Mike; Usselman, Marion

    2016-01-01

    This paper illustrates the use of simulation-based performance assessment (PA) methodology in a recent study of eighth-grade students' understanding of physical science concepts. A set of four simulation-based PA tasks were iteratively developed to assess student understanding of an array of physical science concepts, including net force,…

  8. Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (Final Report, Sep 2008)

    Science.gov (United States)

    EPA announced the availability of the final report, Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria final assessment. This report represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scien...

  9. Does Formative Assessment Improve Student Learning and Performance in Soil Science?

    Science.gov (United States)

    Kopittke, Peter M.; Wehr, J. Bernhard; Menzies, Neal W.

    2012-01-01

    Soil science students are required to apply knowledge from a range of disciplines to unfamiliar scenarios to solve complex problems. To encourage deep learning (with student performance an indicator of learning), a formative assessment exercise was introduced to a second-year soil science subject. For the formative assessment exercise, students…

  10. A Behavioral Science Assessment of Selected Principles of Consumer Education.

    Science.gov (United States)

    Friedman, Monroe; Rees, Jennifer

    1988-01-01

    This study examined the bahavioral science support for a set of 20 food-buying principles. Three types of principles are found; they differ in the consumer behaviors they recommend and in the nature and strength of support they receive in the behavioral science literature. (Author/JOW)

  11. Assessment of Student Memo Assignments in Management Science

    Science.gov (United States)

    Williams, Julie Ann Stuart; Stanny, Claudia J.; Reid, Randall C.; Hill, Christopher J.; Rosa, Katie Martin

    2015-01-01

    Frequently in Management Science courses, instructors focus primarily on teaching students the mathematics of linear programming models. However, the ability to discuss mathematical expressions in business terms is an important professional skill. The authors present an analysis of student abilities to discuss management science concepts through…

  12. Assessment of Examinations in Computer Science Doctoral Education

    Science.gov (United States)

    Straub, Jeremy

    2014-01-01

    This article surveys the examination requirements for attaining degree candidate (candidacy) status in computer science doctoral programs at all of the computer science doctoral granting institutions in the United States. It presents a framework for program examination requirement categorization, and categorizes these programs by the type or types…

  13. Complexometric determination: Part I - EDTA and complex formation with the Cu2+ ion

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2002-01-01

    Full Text Available Compounds forming very stable complexes - chelates, have a wide field of application in analytical chemistry. The most famous group of these compounds are complexons. Complexons represent organic polyaminocarbonic acids as for example ethylenediaminetetraacetic acid (EDTA and its salts. The EDTA molecule has six coordinative sites. It is a hexadentate ligands i.e. it has two binding nitrogen atoms and four oxygen atoms from carboxyl groups and it forms complexes with almost all metal ions. EDTA as a tetraprotonic acid, H4Y disociates through four steps, yielding the ions HsY-, H2Y2-, HY3- and Y4-. Which of the EDTA forms will be encountered in a solution, depends on the pH. Due to the poor solubility of EDTA in pure water, as well as in most organic solvents, the disodium salt of EDTA Na2H2Y-2H2O, under the commercial name complexon III, is utilized for analytical determinations. In water, EDTA forms soluble, stabile chelate complexes with all cations, at the molar ratio 1:1, regardless of the charge of the metal ion. In contrast to other equilibria, which are mainly defined by Le Chatellier's principle, equilibria related to metal-EDTA complex formation are also dependent on the influence of the secondary equilibria of EDTA complex formation. Complexing reactions, which are equilibrium reactions, are simultaneously influenced by the following factors: solution pH and the presence of complexing agents which may also form a stabile complex with metal ions. The secondary reaction influence may be viewed and monitored through conditional stability constants. In the first part of the paper, the reaction of the formation of the Cu2+-ion complex with EDTA is analyzed beginning from the main reaction through various influences of secondary reactions on the complex Cu2+-EDTA: pH effect, complexation effect and hydrolysis effect. The equations are given for conditional stability constants, which include equilibrium reactions under actual conditions.

  14. Seeking Missing Pieces in Science Concept Assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch Analysis

    Science.gov (United States)

    Ding, Lin

    2014-01-01

    Discipline-based science concept assessments are powerful tools to measure learners' disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA) has been broadly used to gauge student conceptions of key electricity and magnetism (E&M) topics in college-level introductory physics courses.…

  15. Synthesis and characterization of TEP-EDTA-regulated bioactive hydroxyapatite

    Science.gov (United States)

    Haders, Daniel Joseph, II

    Hydroxyapatite (HA), Ca10(PO4)6(OH) 2, the stoichiometric equivalent of the ceramic phase of bone, is the preferred material for hard tissue replacement due to its bioactivity. However, bioinert metals are utilized in load-bearing orthopedic applications due to the poor mechanical properties of HA. Consequently, attention has been given to HA coatings for metallic orthopedic implants to take advantage of the bioactivity of HA and the mechanical properties of metals. Commercially, the plasma spray process (PS-HA) is the method most often used to deposit HA films on metallic implants. Since its introduction in the 1980's, however, concerns have been raised about the consequences of PS-HA's low crystallinity, lack of phase purity, lack of film-substrate chemical adhesion, passivation properties, and difficulty in coating complex geometries. Thus, there is a need to develop inexpensive reproducible next-generation HA film deposition techniques, which deposit high crystallinity, phase pure, adhesive, passivating, conformal HA films on clinical metallic substrates. The aim of this dissertation was to intelligently synthesize and characterize the material and biological properties of HA films on metallic substrates synthesized by hydrothermal crystallization, using thermodynamic phase diagrams as the starting point. In three overlapping interdisciplinary studies the potential of using ethylenediamine-tetraacetic acid/triethyl phosphate (EDTA/TEP) doubly regulated hydrothermal crystallization to deposit HA films, the TEP-regulated, time-and-temperature-dependent process by which films were deposited, and the bioactivity of crystallographically engineered films were investigated. Films were crystallized in a 0.232 molal Ca(NO3)2-0.232 molal EDTA-0.187 molal TEP-1.852 molal KOH-H2O chemical system at 200°C. Thermodynamic phase diagrams demonstrated that the chosen conditions were expected to produce Ca-P phase pure HA, which was experimentally confirmed. EDTA regulation of

  16. Impacts of EDTA on uptake and accumulation of Cu 2+ by spinach ...

    African Journals Online (AJOL)

    The effects of EDTA on Cu2+ uptake by spinach (spinacia oleracea L) seedlings replanted in hydroponic solutions in a greenhouse were investigated. Four week old seedlings were exposed to various doses of Cu2+ (0, 5, 10, 15, and 20mg/L) and constant concentration of EDTA (10mM). During the exposure, the plant ...

  17. Coulometric Titration of Ethylenediaminetetraacetate (EDTA) with Spectrophotometric Endpoint Detection: An Experiment for the Instrumental Analysis Laboratory

    Science.gov (United States)

    Williams, Kathryn R.; Young, Vaneica Y.; Killian, Benjamin J.

    2011-01-01

    Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

  18. Chemodynamics of EDTA in a simulated mixed waste: the Hanford Site's complex concentrate waste

    International Nuclear Information System (INIS)

    Toste, A.P.; Ohnuki, Toshihiko

    1999-01-01

    Enormous stockpiles of mixed wastes at the USDOE's Hanford Site, the original US plutonium production facility, await permanent disposal. One mixed waste derived from reprocessing spent fuel was found to contain numerous nuclear related organics including chelating agents like EDTA and complexing agents, which have been used as decontamination agents, etc. Their presence in actual mixed wastes indicates that the organic content of nuclear wastes is dynamic and complicate waste management efforts. The subjects of this report is the chemo-degradation of EDTA degradation in a simulant Hanford's complex concentrate waste. The simulant was prepared by adding EDTA to an inorganic matrix, which was formulated based on past analyses of the actual waste. Aliquots of the EDTA simulant were withdrawn at different time points, derivatized via methylation and analyzed by gas chromatography and Gc/MS to monitor the disappearance of EDTA and the appearance of its' degradation products. This report also compares the results of EDTA's chemo-degradation to the g-radiolysis of EDTA in the simulant, the subject of a recently published article. Finally based on the results of these two studies, an assesment of the potential impact of EDTA degradation on the management of mixed wastes is offered. (J.P.N.)

  19. Determination of Glomerular Filtration Rate with {sup 51}Cr, {sup 58}Co, {sup 114m}In, {sup 115m}In and {sup 169}Yb- Labelled EDTA and DTPA Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Gy.; Pal, I.; Stuetzel, M.; Jaky, L. [Third Department of Medicine, University Medical School and Institute of Isotopes of the Hungarian Academy of Sciences, Budapest (Hungary)

    1971-02-15

    Some metal complexes are suitable for determination of the glomerular filtration rate (GFR). A series of labelled EDTA and DTPA complexes have been produced during the last two years by the Isotope Institute of the Hungarian Academy of Sciences. The common property of EDTA and DTPA complexes is their great stability, which is a major advantage over the iodinated compounds. We have demonstrated that none of the complexes used by us combine with plasma proteins or penetrate into the red blood cells. There is evidence that EDTA and DTPA leave the body exclusively by way of glomerular filtration. The results of more than 600 cases are presented. {sup 169}Yb EDTA was used in 315, {sup 51}Cr EDTA in 126, {sup 114m}In EDTA in 83, {sup 58}Co DTPA in 72 and {sup 115m}In EDTA in 28 cases for determination of GFR. The injected activity was 0.3 -4.0 {mu}Ci/kg body weight. In most cases the result has been compared with the 24-h endogenous creatine clearance, and in 50 cases with inulin clearance also. In general the single-shot method was used. Blood samples were taken about the first and the second hour after injection of the isotope. A formula is given for calculating GFR. In a few cases we administered the isotope in the same way as inulin (priming dose and constant plasma concentration sustained by an infusion pump). Our results show that the single-shot method is a very suitable one in routine clinical practice either in states of normal or reduced kidney function. Using the single-shot method for GFR determination is especially important in those cases where the collection of urine is impossible without using a catheter, which always entails the risk of infection. Results are reliable even in disorders of the urinary tract. During or after the procedure no side effects could be observed. (author)

  20. The Effects of Motivation on Student Performance on Science Assessments

    Science.gov (United States)

    Glenn, Tina Heard

    Academic achievement of public school students in the United States has significantly fallen behind other countries. Students' lack of knowledge of, or interest in, basic science and math has led to fewer graduates of science, technology, engineering, and math-related fields (STEM), a factor that may affect their career success and will certainly affect the numbers in the workforce who are prepared for some STEM jobs. Drawing from self-determination theory and achievement theory, the purpose of this correlational study was to determine whether there were significant relationships between high school academic performance in science classes, motivations (self-efficacy, self-regulation, and intrinsic and extrinsic goal orientation), and academic performance in an introductory online college biology class. Data were obtained at 2 points in time from a convenience multiethnic sample of adult male ( n =16) and female (n = 49) community college students in the southeast United States. Correlational analyses indicated no statistically significant relationships for intrinsic or extrinsic goal orientation, self-efficacy, or self-regulation with high school science mean-GPA nor college biology final course grade. However, high school academic performance in science classes significantly predicted college performance in an entry-level online biology class. The implications of positive social change include knowledge useful for educational institutions to explore additional factors that may motivate students to enroll in science courses, potentially leading to an increase in scientific knowledge and STEM careers.

  1. Formative and summative assessment of science in English primary schools: evidence from the Primary Science Quality Mark

    Science.gov (United States)

    Earle, Sarah

    2014-05-01

    Background:Since the discontinuation of Standard Attainment Tests (SATs) in science at age 11 in England, pupil performance data in science reported to the UK government by each primary school has relied largely on teacher assessment undertaken in the classroom. Purpose:The process by which teachers are making these judgements has been unclear, so this study made use of the extensive Primary Science Quality Mark (PSQM) database to obtain a 'snapshot' (as of March 2013) of the approaches taken by 91 English primary schools to the formative and summative assessment of pupils' learning in science. PSQM is an award scheme for UK primary schools. It requires the science subject leader (co-ordinator) in each school to reflect upon and develop practice over the course of one year, then upload a set of reflections and supporting evidence to the database to support their application. One of the criteria requires the subject leader to explain how science is assessed within the school. Sample:The data set consists of the electronic text in the assessment section of all 91 PSQM primary schools which worked towards the Quality Mark in the year April 2012 to March 2013. Design and methods:Content analysis of a pre-existing qualitative data set. Text in the assessment section of each submission was first coded as describing formative or summative processes, then sub-coded into different strategies used. Results:A wide range of formative and summative approaches were reported, which tended to be described separately, with few links between them. Talk-based strategies are widely used for formative assessment, with some evidence of feedback to pupils. Whilst the use of tests or tracking grids for summative assessment is widespread, few schools rely on one system alone. Enquiry skills and conceptual knowledge were often assessed separately. Conclusions:There is little consistency in the approaches being used by teachers to assess science in English primary schools. Nevertheless

  2. Improving Science Attitude and Creative Thinking through Science Education Project: A Design, Implementation and Assessment

    Science.gov (United States)

    Sener, Nilay; Türk, Cumhur; Tas, Erol

    2015-01-01

    The purpose of this study is to examine the effects of a science education project implemented in different learning environments on secondary school students' creative thinking skills and their attitudes to science lesson. Within this scope, a total of 50 students who participated in the nature education project in Samsun City in 2014 make up the…

  3. Using the EDTA Hole Scavenger to Accelerate Decolorization in the Immobilized Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    raziye Asgari

    2015-07-01

    Full Text Available This study investigated the effect of EDTA as a hole scavenger on accelerating the photocatalytic decolorization of direct blue 71 as a non-degradable model pollutant with nano TiO2 powder immobilized on a cementitious bed. For this purpose, 75 mg/L of the dye was decolorized in 75 minutes with 0.03 M of EDTA at a pH level of 6 and under irradiation produced by a 60-W UV-C lamp. This is while decolorization under identical conditions but in the absence of EDTA had been accomplished in 225 minutes. The experiment, therefore, confirmed the accelerating effect of the scavenger on decolorization. The kinetics of the photocatalytic process with EDTA followed a first order reaction with a constant rate of 0.05 min-1, which is 2.5 times faster than the process without EDTA.

  4. Responsible research and innovation indicators for science education assessment: how to measure the impact?

    Science.gov (United States)

    Heras, Maria; Ruiz-Mallén, Isabel

    2017-12-01

    The emerging paradigm of responsible research and innovation (RRI) in the European Commission policy discourse identifies science education as a key agenda for better equipping students with skills and knowledge to tackle complex societal challenges and foster active citizenship in democratic societies. The operationalisation of this broad approach in science education demands, however, the identification of assessment frameworks able to grasp the complexity of RRI process requirements and learning outcomes within science education practice. This article aims to shed light over the application of the RRI approach in science education by proposing a RRI-based analytical framework for science education assessment. We use such framework to review a sample of empirical studies of science education assessments and critically analyse it under the lenses of RRI criteria. As a result, we identify a set of 86 key RRI assessment indicators in science education related to RRI values, transversal competences and experiential and cognitive aspects of learning. We argue that looking at science education through the lenses of RRI can potentially contribute to the integration of metacognitive skills, emotional aspects and procedural dimensions within impact assessments so as to address the complexity of learning.

  5. Using Educative Assessments to Support Science Teaching for Middle School English-language Learners

    Science.gov (United States)

    Buxton, Cory A.; Allexsaht-Snider, Martha; Suriel, Regina; Kayumova, Shakhnoza; Choi, Youn-jeng; Bouton, Bobette; Baker, Melissa

    2013-03-01

    Grounded in Hallidayan perspectives on academic language, we report on our development of an educative science assessment as one component of the language-rich inquiry science for English-language learners teacher professional learning project for middle school science teachers. The project emphasizes the role of content-area writing to support teachers in diagnosing their students' emergent understandings of science inquiry practices, science content knowledge, and the academic language of science, with a particular focus on the needs of English-language learners. In our current school policy context, writing for meaningful purposes has received decreased attention as teachers struggle to cover large numbers of discrete content standards. Additionally, high-stakes assessments presented in multiple-choice format have become the definitive measure of student science learning, further de-emphasizing the value of academic writing for developing and expressing understanding. To counter these trends, we examine the implementation of educative assessment materials—writing-rich assessments designed to support teachers' instructional decision making. We report on the qualities of our educative assessment that supported teachers in diagnosing their students' emergent understandings, and how teacher-researcher collaborative scoring sessions and interpretation of assessment results led to changes in teachers' instructional decision making to better support students in expressing their scientific understandings. We conclude with implications of this work for theory, research, and practice.

  6. Views of nature of science questionnaire: Toward valid and meaningful assessment of learners' conceptions of nature of science

    Science.gov (United States)

    Lederman, Norm G.; Abd-El-Khalick, Fouad; Bell, Randy L.; Schwartz, Renée S.

    2002-08-01

    Helping students develop informed views of nature of science (NOS) has been and continues to be a central goal for kindergarten through Grade 12 (K-12) science education. Since the early 1960s, major efforts have been undertaken to enhance K-12 students and science teachers' NOS views. However, the crucial component of assessing learners' NOS views remains an issue in research on NOS. This article aims to (a) trace the development of a new open-ended instrument, the Views of Nature of Science Questionnaire (VNOS), which in conjunction with individual interviews aims to provide meaningful assessments of learners' NOS views; (b) outline the NOS framework that underlies the development of the VNOS; (c) present evidence regarding the validity of the VNOS; (d) elucidate the use of the VNOS and associated interviews, and the range of NOS aspects that it aims to assess; and (e) discuss the usefulness of rich descriptive NOS profiles that the VNOS provides in research related to teaching and learning about NOS. The VNOS comes in response to some calls within the science education community to go back to developing standardized forced-choice paper and pencil NOS assessment instruments designed for mass administrations to large samples. We believe that these calls ignore much of what was learned from research on teaching and learning about NOS over the past 30 years. The present state of this line of research necessitates a focus on individual classroom interventions aimed at enhancing learners' NOS views, rather than on mass assessments aimed at describing or evaluating students' beliefs.

  7. Overall welfare assessment of laying hens: Comparing science-based, environmental-based and animal-based assessments

    NARCIS (Netherlands)

    Shimmura, T.; Bracke, M.B.M.; Mol, de R.M.; Hirahara, S.; Tanaka, T.

    2011-01-01

    To increase the validity of evaluations and facilitate expansion and maintenance of assessment systems, we constructed a database of studies on the welfare of laying hens around the world. On the basis of this database, we devised a science-based welfare assessment model. Our model includes

  8. Assessment that Matters: Integrating the "Chore" of Department-Based Assessment with Real Improvements in Political Science Education

    Science.gov (United States)

    Deardorff, Michelle D.; Folger, Paul J.

    2005-01-01

    Assessment requirements often raise great concerns among departments and faculty: fear of loss of autonomy, distraction from primary departmental goals, and the creation of alien and artificial external standards. This article demonstrates how one political science department directly responded to their own unique circumstances in assessing their…

  9. Stability of BDNF in Human Samples Stored Up to 6 Months and Correlations of Serum and EDTA-Plasma Concentrations.

    Science.gov (United States)

    Polyakova, Maryna; Schlögl, Haiko; Sacher, Julia; Schmidt-Kassow, Maren; Kaiser, Jochen; Stumvoll, Michael; Kratzsch, Jürgen; Schroeter, Matthias L

    2017-06-03

    Brain-derived neurotrophic factor (BDNF), an important neural growth factor, has gained growing interest in neuroscience, but many influencing physiological and analytical aspects still remain unclear. In this study we assessed the impact of storage time at room temperature, repeated freeze/thaw cycles, and storage at -80 °C up to 6 months on serum and ethylenediaminetetraacetic acid (EDTA)-plasma BDNF. Furthermore, we assessed correlations of serum and plasma BDNF concentrations in two independent sets of samples. Coefficients of variations (CVs) for serum BDNF concentrations were significantly lower than CVs of plasma concentrations ( n = 245, p = 0.006). Mean serum and plasma concentrations at all analyzed time points remained within the acceptable change limit of the inter-assay precision as declared by the manufacturer. Serum and plasma BDNF concentrations correlated positively in both sets of samples and at all analyzed time points of the stability assessment ( r = 0.455 to r s = 0.596; p plasma up to 6 months. Due to a higher reliability, we suggest favoring serum over EDTA-plasma for future experiments assessing peripheral BDNF concentrations.

  10. Development Module Oriented Science Technology Society Indue Science Literacy Assessment for 7th-Grade Junior High School Students in 2nd -Semester

    Science.gov (United States)

    Arbi, Y. R.; Sumarmin, R.; Putri, D. H.

    2018-04-01

    The problem in the science learning process is the application of the scientific approach takes a long time in order to provide conceptual understanding to the students, there is no teaching materials that can measure students reasoning and thinking ability, and the assessment has not measured students reasoning and literacy skills.The effort can be done is to develop science technology society module indue science literacy assessment. The purpose of the research was to produce a module oriented society indue science science technology literacy assessment. The research is development research using Plomp model, consist of preliminary, prototyping, and assessment phase. Data collect by questionnare and documantion. The result there is science technology society module indue science literacy assessment is very valid.

  11. Assessment of a Bioinformatics across Life Science Curricula Initiative

    Science.gov (United States)

    Howard, David R.; Miskowski, Jennifer A.; Grunwald, Sandra K.; Abler, Michael L.

    2007-01-01

    At the University of Wisconsin-La Crosse, we have undertaken a program to integrate the study of bioinformatics across the undergraduate life science curricula. Our efforts have included incorporating bioinformatics exercises into courses in the biology, microbiology, and chemistry departments, as well as coordinating the efforts of faculty within…

  12. Assessing Bilingual Knowledge Organization in Secondary Science Classrooms =

    Science.gov (United States)

    Wu, Jason S.

    Improving outcomes for English language learners (ELLs) in secondary science remains an area of high need. The purpose of this study is to investigate bilingual knowledge organization in secondary science classrooms. This study involved thirty-nine bilingual students in three biology classes at a public high school in The Bronx, New York City. Methods included an in-class survey on language use, a science content and English proficiency exam, and bilingual free-recalls. Fourteen students participated in bilingual free-recalls which involved a semi-structured process of oral recall of information learned in science class. Free-recall was conducted in both English and Spanish and analyzed using flow-map methods. Novel methods were developed to quantify and visualize the elaboration and mobilization of ideas shared across languages. It was found that bilingual narratives displayed similar levels of organizational complexity across languages, though English recalls tended to be longer. English proficiency was correlated with narrative complexity in English. There was a high degree of elaboration on concepts shared across languages. Finally, higher Spanish proficiency correlated well with greater overlapping elaboration across languages. These findings are discussed in light of current cognitive theory before presenting the study's limitations and future directions of research.

  13. Missouri Assessment Program (MAP), Spring 2000: Secondary Science, Released Items, Grade 10.

    Science.gov (United States)

    Missouri State Dept. of Elementary and Secondary Education, Jefferson City.

    This assessment sample provides information on the Missouri Assessment Program (MAP) for grade 10 science. The sample consists of six items taken from the test booklet and scoring guides for the six items. The items assess ecosystems, mechanics, and data analysis. (MM)

  14. Comparing Panelists' Understanding of Standard Setting across Multiple Levels of an Alternate Science Assessment

    Science.gov (United States)

    Hansen, Mary A.; Lyon, Steven R.; Heh, Peter; Zigmond, Naomi

    2013-01-01

    Large-scale assessment programs, including alternate assessments based on alternate achievement standards (AA-AAS), must provide evidence of technical quality and validity. This study provides information about the technical quality of one AA-AAS by evaluating the standard setting for the science component. The assessment was designed to have…

  15. Assessing the Attitudes and Beliefs of Preservice Middle School Science Teachers toward Biologically Diverse Animals

    Science.gov (United States)

    Wagler, Ron; Wagler, Amy

    2015-01-01

    The purpose of this study was to assess the relationship between United States (US) preservice middle school science teacher characteristics, their attitude toward a specific animal and their belief concerning the likelihood of incorporating information about that specific animal into their future science classroom. The study participants…

  16. The Use of Illustrations in Large-Scale Science Assessment: A Comparative Study

    Science.gov (United States)

    Wang, Chao

    2012-01-01

    This dissertation addresses the complexity of test illustrations design across cultures. More specifically, it examines how the characteristics of illustrations used in science test items vary across content areas, assessment programs, and cultural origins. It compares a total of 416 Grade 8 illustrated items from the areas of earth science, life…

  17. Spiral and Project-Based Learning with Peer Assessment in a Computer Science Project Management Course

    Science.gov (United States)

    Jaime, Arturo; Blanco, José Miguel; Domínguez, César; Sánchez, Ana; Heras, Jónathan; Usandizaga, Imanol

    2016-01-01

    Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning,…

  18. International Assessment: A Rasch Model and Teachers' Evaluation of TIMSS Science Achievement Items

    Science.gov (United States)

    Glynn, Shawn M.

    2012-01-01

    The Trends in International Mathematics and Science Study (TIMSS) is a comparative assessment of the achievement of students in many countries. In the present study, a rigorous independent evaluation was conducted of a representative sample of TIMSS science test items because item quality influences the validity of the scores used to inform…

  19. 78 FR 14299 - Notification of a Public Meeting of the Science Advisory Board Chemical Assessment Advisory...

    Science.gov (United States)

    2013-03-05

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9786-6] Notification of a Public Meeting of the Science...: Notice. SUMMARY: The Environmental Protection Agency (EPA or agency) Science Advisory Board (SAB) Staff Office announces a public meeting of the SAB Chemical Assessment Advisory Committee (CAAC) to receive a...

  20. Using the Mixture Rasch Model to Explore Knowledge Resources Students Invoke in Mathematic and Science Assessments

    Science.gov (United States)

    Zhang, Danhui; Orrill, Chandra; Campbell, Todd

    2015-01-01

    The purpose of this study was to investigate whether mixture Rasch models followed by qualitative item-by-item analysis of selected Programme for International Student Assessment (PISA) mathematics and science items offered insight into knowledge students invoke in mathematics and science separately and combined. The researchers administered an…

  1. Assessing the Impact of Gender and Race on Earnings in the Library Science Labor Market

    Science.gov (United States)

    Sweeper, Darren; Smith, Steven A.

    2010-01-01

    Using data from the 2003 National Survey of College Graduates, this paper examines earnings in the library science labor market and assesses the impact of gender on the income attainment process. We use this cross-sectional dataset to determine if there are significant income differences between male and female library science professionals. The…

  2. Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Thaís Heloisa Vaz Farias

    2016-05-01

    Full Text Available Abstract: The present study aimed to evaluate the effects of Na heparin and Na2EDTA on blood of Piaractus mesopotamicus (360.7±42.4g, 26.4±1.0cm. Twenty fishes were sampled in two experiment trials, ten for erythrocyte fragility analysis and ten for hematologic and plasma biochemical study. The blood collected by venous-caudal puncture was fractioned and stored in anticoagulants solution: Na2EDTA 10%, Na2EDTA 3%, Na heparin 5000 IU and Na heparin 100 IU. Plasmatic levels of calcium presented in the Na2EDTA stored samples were about 80% lower than both heparin groups. Blood samples of P. mesopotamicus stored with Na2EDTA demonstrated increase in the hematocrit and MCV, and decrease in MCHC. The dose-response effect was observed in this study. The results are reinforced by the higher levels of plasmatic protein and hemolysis presented in the Na2EDTA 10% stored blood, confirming the deleterious effect of this anticoagulant treatment on the quality of blood samples. Na2EDTA is not indicated to store P. mesopotamicus blood samples, but sodium heparin at 100 IU is the most recommended anticoagulant, since this treatment presented the lower rate of alterations in the stored blood.

  3. Highly concentrated EDTA gel improves cleaning efficiency of root canal preparation in vitro.

    Science.gov (United States)

    Putzer, P; Hoy, L; Günay, H

    2008-12-01

    Debris and smear layer, as a product of mechanical root canal instrumentation, reduce the effectiveness of pharmacological substances to prevent post-treatment diseases and impair direct contact of filling materials with a clean dentinal surface. The aim of this in vitro study was to investigate the presence and localization of debris and smear layer via scanning electron microscope analysis after standardized root canal preparation with different chelating agents. Dentin surfaces received treatment with: (1) 15% ethylenediaminetetraacetic acid (EDTA), (2) 18.6% EDTA (3) and 24% EDTA or without any demineralizing chemicals as control. Forty vertically split human premolars were sputtered and divided into coronal, middle, and apical sections, followed by a randomized, blinded score evaluation using five scores. Pairwise comparisons of all treatment groups against a control group have been performed by Mann-Whitney U test and the Kruskal-Wallis test. Debris grades showed no significant difference between the three regions of the root canals, except for 18.6% EDTA in the central third. Smear layer and smear plug removal was concentration-dependent. Removal of the smear layer in the three areas showed that there was a statistically significant difference between all parts when using 18.6% and 24% EDTA concentrations compared with the control. The best smear layer removal in the apical region was observed using a 24% EDTA gel as chelating agent and lubricant. The usage of EDTA gel >/=18.6% presented a better cleaning regime when compared to the control group.

  4. "Off-the-Shelf" K2-EDTA for Calcific Band Keratopathy.

    Science.gov (United States)

    Lee, Marco E; Ouano, Dean P; Shapiro, Brett; Fong, Andrew; Coroneo, Minas T

    2018-07-01

    To explore the effectiveness of "off-the-shelf" dipotassium-ethylenediaminetetraacetic acid (K2-EDTA) as an alternative to sodium EDTA as chelation therapy in removal of calcific band keratopathy (CBK). This study was a retrospective case series involving 4 patients with CBK who underwent superficial keratectomy and subsequent chelation therapy with K2-EDTA in a single center (Coastal Eye Clinic) by the same surgeon. Visual acuity and symptomatic relief were the main outcomes measured in our study. All 4 participants in this study were female with an average age of 80.3 years. Three of the patients with reasonable baseline visual acuity experienced improved visual acuity at 1 month. The other patient with multiple ocular comorbidities and severely reduced visual potential reported symptomatic pain relief at 1-month follow-up after the intervention. K2-EDTA seems to be an effective alternative to disodium EDTA in its ability to clear calcific plaques and restore visual function. Because of the logistical difficulties associated with acquiring disodium EDTA, and the relative abundance of K2-EDTA in health-care facilities, we believe that our findings warrant further investigation into its use as a more accessible and cost-effective chelating agent in CBK.

  5. Characterization of EDTA-soluble polysaccharides from the scape of Musa paradisiaca (banana).

    Science.gov (United States)

    Raju, T S; Jagadish, R L; Anjaneyalu, Y V

    2001-02-01

    The polysaccharide components present in the scape of Musa paradisiaca (banana) were fractionated into water-soluble (WSP), EDTA-soluble (EDTA-SP), alkali-soluble (ASP) and alkali-insoluble (AISP) polysaccharide fractions [Anjaneyalu, Jagadish and Raju (1997) Glycoconj. J. 14, 507-512]. The EDTA-SP was further fractionated by iso-amyl alcohol into EDTA-SP-A and EDTA-SP-B. The homogeneity of these two polysaccharides was established by repeated precipitation with iso-amyl alcohol, gel-filtration chromatography and sedimentation analysis. The polysaccharides were characterized by monosaccharide composition analysis, methylation linkage analysis, iodine affinity, ferricyanide number, blue value, hydrolysis with alpha-amylase, gold-electron microscopy and X-ray diffraction spectroscopy. Data from all of these studies suggest that EDTA-SP-A is a branched amylose-type alpha-D-glucan and that EDTA-SP-B is a highly branched amylopectin-type polymer. The nature of the branching patterns of these polysaccharides suggests that they are unique to M. paradisiaca.

  6. Effect of EDTA Conditioning on Microleakage of Four Adhesive Systems in Composite Restorations

    Directory of Open Access Journals (Sweden)

    F. Shafiei

    2008-12-01

    Full Text Available Objective: Evaluating the effect of dentin conditioning with EDTA on microleakage of composite resin restorations, using two etch and rinse and two self-etch adhesives.Materials and Methods: One hundred and sixty extracted molars received class V cavity preparations right under the CEJ and were randomly divided into eight groups of 20, usingfour different adhesive systems. These adhesives included Adper Scotchbond Multi-purpose (SBMP, Adper Single Bond (SB, Clearfil SE Bond (CSEB, and Adper Prompt L-Pop (PLP. In the SBMP and SB experimental groups, EDTA was applied instead of phosphoric acid. In the CSEB and PLP experimental groups, EDTA conditioning was added to the bonding process. After thermocycling, the amount of dye penetration was evaluated using stereomicroscope. The data were analyzed using the Kruskal-Wallis and Dunn tests.Results: Two etch and rinse adhesives (SBMP, SB showed a significantly lower micro-leakage than the two self-etch adhesives, CSEB and PLP, (P<0.05. No significant differ-ence was observed among the experimental groups. PLP and CSEB showed significantly less microleakage using EDTA conditioning (P<0.05. There was no significant difference for SBMP and SB when applying either phosphoric acid or EDTA.Conclusion: In the cases of SBMP and SB, EDTA conditioning is as effective as phos-phoric acid in preventing microleakage. In cases of CSEB and PLP, EDTA conditioning can significantly improve the sealing ability.

  7. “Which Child Left Behind”: Historical Issues Regarding Equity in Science Assessment

    Directory of Open Access Journals (Sweden)

    J. Joy Cumming

    2013-08-01

    Full Text Available Assessment of learning plays a dominant role in formal education in the forms of determining features of curriculum that are emphasized, pedagogic methods that teachers use with their students, and parents’ and employers’ understanding of how well students have performed. A common perception is that fair assessment applies the same mode of assessment and content focus for all students—the approach of assessments in international comparative studies of science achievement. This article examines research evidence demonstrating that the act of assessment is not neutral—different forms of assessment advantage or disadvantage groups of students on the basis of family backgrounds, gender, race, or disability. Assessment that implicitly or explicitly captures the social capital of the child serves to consolidate, not address, educational equity. The article provides an overview of ways that science curriculum focus and assessment can introduce bias in the identification of student achievement. It examines the effect of changes to curriculum and assessment approaches in science, and relationships between assessment of science and the cultural context of the student. Recommendations are provided for science–assessment research to address bias for different groups of students.

  8. Embedded Assessment as an Essential Method for Understanding Public Engagement in Citizen Science

    Directory of Open Access Journals (Sweden)

    Rachel Becker-Klein

    2016-05-01

    Full Text Available Citizen science is an important way of engaging a broad range of audiences in science inquiry by participating in research that asks novel questions and unearths new knowledge and new questioning. Though citizen science projects are quite diverse in their scientific pursuits, all projects share the common element of involving volunteers directly in some aspect of science inquiry. Thus, it is essential for citizen science projects to determine their participants’ capacity to learn and successfully perform science inquiry skills, such as making scientific observations, collecting and analyzing data, and sharing findings. Such skill gains are essential to (a ensure high quality data that can be used in meaningful scientific research, and (b achieve broader goals such as developing a participant’s identity as a contributor to science. However, we do not yet fully understand how improvement in participants’ inquiry skills through citizen science advances our knowledge of public engagement with science. In this essay, we offer embedded assessment as an effective method to capture participant skill gains, and encourage citizen science leaders, evaluators, and researchers to develop authentic methods that address the complexities of measuring skill development within the context of citizen science.

  9. SUSTAINABILITY LOGISTICS BASING SCIENCE AND TECHNOLOGY OBJECTIVE DEMONSTRATION; SELECTED TECHNOLOGY ASSESSMENT

    Science.gov (United States)

    2018-03-22

    BASING SCIENCE AND TECHNOLOGY OBJECTIVE – DEMONSTRATION; SELECTED TECHNOLOGY ASSESSMENT by Gregg J. Gildea Paul D. Carpenter Benjamin J...Campbell William F. Harris* Michael A. McCluskey** and José A. Miletti*** *General Dynamics Information Technology Fairfax, VA 22030 **Maneuver...SCIENCE AND TECHNOLOGY OBJECTIVE – DEMONSTRATION; SELECTED TECHNOLOGY ASSESSMENT 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  10. A Comparative Study of [CaEDTA](2-) and [MgEDTA](2-): Structural and Dynamical Insights from Quantum Mechanical Charge Field Molecular Dynamics.

    Science.gov (United States)

    Tirler, Andreas O; Hofer, Thomas S

    2015-07-09

    Structure and dynamics of [MgEDTA](2-) and [CaEDTA](2-) complexes in aqueous solution have been investigated via quantum mechanical/molecular mechanical (QM/MM) simulations. While for the first a 6-fold octahedral complex has been observed, the presence of an additional coordinating water ligand has been observed in the latter case. Because of rapidly exchanging water molecules, this 7-fold coordination complex was found to form pentagonal bipyramidal as well as capped trigonal prismatic configurations along the simulation interchanging on the picosecond time scale. Also in the case of [MgEDTA](2-) a trigonal prismatic configuration has been observed for a very short time period of approximately 1 ps. This work reports for the first time the presence of trigonal prismatic structures observed in the coordination sphere of [MgEDTA](2-) and [CaEDTA](2-) complexes in aqueous solution. In addition to the detailed characterization of structure and dynamics of the systems, the prediction of the associated infrared spectra indicates that the ion-water vibrational mode found at approximately 250 cm(-1) provides a distinctive measure to experimentally detect the presence of the coordinating water molecule via low-frequency IR setups.

  11. Phosphorus Elimination at Sodium Silicate from Quartz Sand Roasted with Complexation using Chitosan-EDTA

    Science.gov (United States)

    Wahyuningsih, S.; Ramelan, A. H.; Suharty, N. S.; Handayani, M.; Firdiyono, F.; Sulistiyono, E.; Munawaroh, H.; Sari, P. P.; Kristiawan, Y. R.

    2018-03-01

    A phosphorus elimination from sodium silicate solution has been studied. Phosphorus elimination was performed by adding chitosan-EDTA to remove cation phosphorus. Characterization of chitosan-EDTA material was performed using FT-IR, while the decreasing level of phosphorus content was analyzed by quantitative analysis using spectrophotometer UV-Vis refers to SNI 06-6989-2004. The results showed that the content of the sodium silicate can be reduced up to 67.1% through Chitosan-EDTA complexation with phosphorus.

  12. Synthesis and Characterization of EDTA Complexes Useful for Trace Elements Supplementation

    Directory of Open Access Journals (Sweden)

    Baran Enrique J.

    2002-01-01

    Full Text Available The synthesis of two heterobimetallic EDTA complexes, MgCu(EDTA.6H2O and ZnCu(EDTA.6H2O, is described. They were characterized by means of vibrational (infrared and Raman and electronic (reflectance spectroscopy. Several dissolution tests in 0.1 N HCl and simulated gastric juice were also performed. The results support the potential usefulness of these complexes for copper supplementation in human and veterinary medicine and to the simultaneous reinforcement of Mg(II and Zn(II levels.

  13. Potentiometric end point detection in the EDTA titrimetric determination of gallium

    International Nuclear Information System (INIS)

    Gopinath, N.; Renuka, M.; Aggarwal, S.K.

    2001-01-01

    Gallium is titrated in presence of known amount of Fe (III) with EDTA in HNO 3 solution at pH 2 to 3. The end point is detected potentiometrically employing a bright platinum wire - saturated calomel (SCE) reference electrode system, the redox couple being Fe (III) / Fe (II). Since Fe (III) is also titrated by EDTA, it is, therefore, subtracted from titre value to get the EDTA equivalent to gallium only. Precision and accuracy 0.2 to 0.4% was obtained in the results of gallium in the range of 8 to 2 mg. (author)

  14. A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

    OpenAIRE

    Sampaio,José Eduardo Cezar; Campos,Flávia Pavan; Pilatti,Gibson Luiz; Theodoro,Letícia Helena; Leite,Fábio Renato Manzolli

    2005-01-01

    The aim of the present study was to compare root surface smear layer removal following topical application of EDTA and EDTA-T (Texapon). Extracted human teeth had their cementum removed and were mechanically scaled. A total of 220 root specimens were obtained and were randomly assigned to the following groups: I-saline solution (control), II-EDTA; III-EDTA-T. Groups II and III specimens were assigned to different EDTA gel concentrations: 5%, 10%, 15%, 20% and 24%. Smear layer removal score wa...

  15. Enabling Wide-Scale Computer Science Education through Improved Automated Assessment Tools

    Science.gov (United States)

    Boe, Bryce A.

    There is a proliferating demand for newly trained computer scientists as the number of computer science related jobs continues to increase. University programs will only be able to train enough new computer scientists to meet this demand when two things happen: when there are more primary and secondary school students interested in computer science, and when university departments have the resources to handle the resulting increase in enrollment. To meet these goals, significant effort is being made to both incorporate computational thinking into existing primary school education, and to support larger university computer science class sizes. We contribute to this effort through the creation and use of improved automated assessment tools. To enable wide-scale computer science education we do two things. First, we create a framework called Hairball to support the static analysis of Scratch programs targeted for fourth, fifth, and sixth grade students. Scratch is a popular building-block language utilized to pique interest in and teach the basics of computer science. We observe that Hairball allows for rapid curriculum alterations and thus contributes to wide-scale deployment of computer science curriculum. Second, we create a real-time feedback and assessment system utilized in university computer science classes to provide better feedback to students while reducing assessment time. Insights from our analysis of student submission data show that modifications to the system configuration support the way students learn and progress through course material, making it possible for instructors to tailor assignments to optimize learning in growing computer science classes.

  16. Bridging Arctic environmental science and life cycle assessment

    DEFF Research Database (Denmark)

    Johnsen, Fredrik Moltu

    2014-01-01

    Current research aims to make the impact assessment module of life cycle assessment (LCA) less site-generic and thus more relevant to particular regions. The Arctic region attracts its share of interest when it comes to environmental issues, but little research has been performed with the explicit...

  17. Principles of sustainability science to assess alternative energy technologies

    CSIR Research Space (South Africa)

    Brent, AC

    2009-04-01

    Full Text Available , adaptive capacity, and complexity of social-ecological systems to assess the potential of such technologies for increasing the carrying capacity and improving the resilience of social-ecological systems, or to assess the resilience of the technological...

  18. Incorporating computer-assisted assessment to Bachelor of Science ...

    African Journals Online (AJOL)

    The use of computers in education has already been established for decades. Computers have been used from lesson preparations, presentations, and student assessments. Many authors have studied the design, implementation, and impact of computer-assisted assessment (CAA) (also called computer-based testing, ...

  19. Library and Information Science Journal Prestige as Assessed by Library and Information Science Faculty

    Science.gov (United States)

    Manzari, Laura

    2013-01-01

    This prestige study surveyed full-time faculty of American Library Association (ALA)-accredited programs in library and information studies regarding library and information science (LIS) journals. Faculty were asked to rate a list of eighty-nine LIS journals on a scale from 1 to 5 based on each journal's importance to their research and teaching.…

  20. Promoting Prospective Elementary Teachers' Learning to Use Formative Assessment for Life Science Instruction

    Science.gov (United States)

    Sabel, Jaime L.; Forbes, Cory T.; Zangori, Laura

    2015-06-01

    To support elementary students' learning of core, standards-based life science concepts highlighted in the Next Generation Science Standards, prospective elementary teachers should develop an understanding of life science concepts and learn to apply their content knowledge in instructional practice to craft elementary science learning environments grounded in students' thinking. To do so, teachers must learn to use high-leverage instructional practices, such as formative assessment, to engage students in scientific practices and connect instruction to students' ideas. However, teachers may not understand formative assessment or possess sufficient science content knowledge to effectively engage in related instructional practices. To address these needs, we developed and conducted research within an innovative course for preservice elementary teachers built upon two pillars—life science concepts and formative assessment. An embedded mixed methods study was used to evaluate the effect of the intervention on preservice teachers' (n = 49) content knowledge and ability to engage in formative assessment practices for science. Findings showed that increased life content knowledge over the semester helped preservice teachers engage more productively in anticipating and evaluating students' ideas, but not in identifying effective instructional strategies to respond to those ideas.

  1. Computational data sciences for assessment and prediction of climate extremes

    Science.gov (United States)

    Ganguly, A. R.

    2011-12-01

    Climate extremes may be defined inclusively as severe weather events or large shifts in global or regional weather patterns which may be caused or exacerbated by natural climate variability or climate change. This area of research arguably represents one of the largest knowledge-gaps in climate science which is relevant for informing resource managers and policy makers. While physics-based climate models are essential in view of non-stationary and nonlinear dynamical processes, their current pace of uncertainty reduction may not be adequate for urgent stakeholder needs. The structure of the models may in some cases preclude reduction of uncertainty for critical processes at scales or for the extremes of interest. On the other hand, methods based on complex networks, extreme value statistics, machine learning, and space-time data mining, have demonstrated significant promise to improve scientific understanding and generate enhanced predictions. When combined with conceptual process understanding at multiple spatiotemporal scales and designed to handle massive data, interdisciplinary data science methods and algorithms may complement or supplement physics-based models. Specific examples from the prior literature and our ongoing work suggests how data-guided improvements may be possible, for example, in the context of ocean meteorology, climate oscillators, teleconnections, and atmospheric process understanding, which in turn can improve projections of regional climate, precipitation extremes and tropical cyclones in an useful and interpretable fashion. A community-wide effort is motivated to develop and adapt computational data science tools for translating climate model simulations to information relevant for adaptation and policy, as well as for improving our scientific understanding of climate extremes from both observed and model-simulated data.

  2. Intentional research design in implementation science: implications for the use of nomothetic and idiographic assessment.

    Science.gov (United States)

    Lyon, Aaron R; Connors, Elizabeth; Jensen-Doss, Amanda; Landes, Sara J; Lewis, Cara C; McLeod, Bryce D; Rutt, Christopher; Stanick, Cameo; Weiner, Bryan J

    2017-09-01

    The advancement of implementation science is dependent on identifying assessment strategies that can address implementation and clinical outcome variables in ways that are valid, relevant to stakeholders, and scalable. This paper presents a measurement agenda for implementation science that integrates the previously disparate assessment traditions of idiographic and nomothetic approaches. Although idiographic and nomothetic approaches are both used in implementation science, a review of the literature on this topic suggests that their selection can be indiscriminate, driven by convenience, and not explicitly tied to research study design. As a result, they are not typically combined deliberately or effectively. Thoughtful integration may simultaneously enhance both the rigor and relevance of assessments across multiple levels within health service systems. Background on nomothetic and idiographic assessment is provided as well as their potential to support research in implementation science. Drawing from an existing framework, seven structures (of various sequencing and weighting options) and five functions (Convergence, Complementarity, Expansion, Development, Sampling) for integrating conceptually distinct research methods are articulated as they apply to the deliberate, design-driven integration of nomothetic and idiographic assessment approaches. Specific examples and practical guidance are provided to inform research consistent with this framework. Selection and integration of idiographic and nomothetic assessments for implementation science research designs can be improved. The current paper argues for the deliberate application of a clear framework to improve the rigor and relevance of contemporary assessment strategies.

  3. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of edta

    International Nuclear Information System (INIS)

    Busev, A.I.; Ignat'eva, T.I.; Lomakina, L.N.

    1975-01-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was constidered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min.heating. In the lowacid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms lowsoluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated

  4. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Busev, A I; Ignat' eva, T I; Lomakina, L N [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

    1975-05-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was considered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min. heating. In the low acid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms low soluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated.

  5. Radiometric titration of thallium(III) with EDTA

    International Nuclear Information System (INIS)

    Rao, V.R.S.; Pulla Rao, Ch.; Tataiah, G.

    1978-01-01

    Radioactive solutions containing very small amounts of thallium(III) can be determined by radiometric titration using ammonia as hydrolysing agent. Aqueous solution of thallium(I) (both inactive and radioactive) is treated with bromine water till the appearance of the brown colour of bromine, and the solution is warmed to 80 deg C to expel the excess bromine. By this procedure all thallium(I) is quantitatively oxidised to thallium(III). An aqueous solution of ammonia is added to precipitate thallium(III) as thallic oxide. It is then filtered, washed with water to free it from bromide and then dissolved in 2N HCl and the solution is then standardised. 2 ml of this solution is transferred to a 20 ml volumetric flask, 1 ml of radioactive thallium(III) solution to be standardised is added as well as incremental amounts of EDTA solution and mixed thoroughly. Uncomplexed thallium(III) is then precipitated by the addition of an ammonia solution and diluted to 20 ml. Required amount of this mixture is centrifuged. The beta activity of the supernatant aliquot is measured using a GM counter. Quantitative determination of Tl(III) in the range of 1-10 μM can be carried out. The interference of cations such as Au(III), iron(III), Ga(III) can be eliminated by pretreatment of the Tl(III) solution before carrying out radiometric titration. The results obtained are reproducible and accurate to +-3%. (T.I.)

  6. Assessment Strategies for Implementing Ngss in K12 Earth System Science Classrooms

    Science.gov (United States)

    McAuliffe, C.

    2016-12-01

    Several science education researchers have led assessment efforts that provide strategies particularly useful for evaluating the threedimensional learning that is central to NGSS (DeBarger, A. H., Penuel, W. R., Harris, C. J., Kennedy, C. K., 2016; Knight, A. M. & McNeill, K. L., 2015; McNeill, K. L., KatshSinger, R. & Pelletier, P., 2015; McNeill K.L., et.al., 2015; McNeill, K.L., & Krajcik, J.S., 2011; Penuel, W., 2016). One of the basic premises of these researchers is that, "Assessment is a practice of argument from evidence based on what students say, do, and write" and that "the classroom is the richest place to gather evidence of what students know (Penuel, W., 2016). The implementation of the NGSS in Earth System Science provides a unique opportunity for geoscience education researchers to study student learning and contribute to the development of this research as well as for geoscience educators to apply these approaches and strategies in their own work with K12 inservice and preservice educators. DeBarger, A. H., Penuel, W. R., Harris, C. J., Kennedy, C. K. (2016). Building an Assessment Argument to Design and Use Next Generation Science Assessments in Efficacy Studies of Curriculum Interventions. American†Journal†of†Evaluation†37(2) 174192Æ Knight, A. M. & McNeill, K. L. (2015). Comparing students' individual written and collaborative oral socioscientific arguments. International Journal of Environmental and Science Education.10(5), 23647. McNeill, K. L., KatshSinger, R. & Pelletier, P. (2015). Assessing science practices-Moving your class along a continuum. Science Scope. McNeill, K.L., & Krajcik, J.S. (2011). Supporting Grade 5-8 Students in Constructing Explanations in Science: The Claim, Evidence, and Reasoning Framework for Talk and Writing. Upper Saddle River, New Jersey: Pearson. Penuel, W. (2016). Classroom Assessment Strategies for NGSS Earth and Space Sciences. Implementing†the†NGSS†Webinar†Series, February 11, 2016.

  7. Effect of EDTA on luminescence property of Eu+3 doped YPO4 nanoparticles

    International Nuclear Information System (INIS)

    Parchur, A.K.; Okram, G.S.; Singh, R.A.; Tewari, R.; Pradhan, Lina; Vatsa, R.K.; Ningthoujan, R.S.

    2010-01-01

    Nanoparticles of Eu 3+ doped YPO 4 have been prepared using ethylene glycol (EG). Ethylene diamine tetra acetic acid (EDTA) is used as a complexing agent. X-ray diffraction results show that the nanoparticles are crystalline in tetragonal structure. Based on William-Hall relation, the effective crystallite size and strain developed in lattice are found to be 28 nm and 0.002, respectively. With the addition of EDTA, there is a slight shift towards the lower wavelength in emission peaks. Asymmetric ratio of electric to magnetic dipole transition intensities are found to decrease with addition of EDTA. Emission intensity decreases with EDTA because of decrease of particle size as well as decrease of number of Eu 3+ activators per unit volume. These materials are dispersible in water, which may have potential biological applications. (author)

  8. Effect Of EDTA On Luminescence Property Of Eu+3 Doped YPO4 Nanoparticles

    International Nuclear Information System (INIS)

    Parchur, A. K.; Okram, G. S.; Singh, R. A.; Tewari, R.; Pradhan, Lina; Vatsa, R. K.; Ningthoujam, R. S.

    2010-01-01

    Nanoparticles of Eu 3+ doped YPO 4 have been prepared using ethylene glycol (EG). Ethylene diamine tetra acetic acid (EDTA) is used as a complexing agent. X-ray diffraction results show that the nanoparticles are crystalline in tetragonal structure. Based on William-Hall relation, the effective crystallite size and strain developed in lattice are found to be 28 nm and 0.002, respectively. With the addition of EDTA, there is a slight shift towards the lower wavelength in emission peaks. Asymmetric ratio of electric to magnetic dipole transition intensities are found to decrease with addition of EDTA. Emission intensity decreases with EDTA because of decrease of particle size as well as decrease of number of Eu 3+ activators per unit volume. These materials are dispersible in water, which may have potential biological applications.

  9. 51Cr-EDTA plasma clearance in severe renal failure determined by one plasma sample

    DEFF Research Database (Denmark)

    Kamper, A L; Nielsen, S L

    1989-01-01

    Two hundred and thirty-four measurements of standard 51Cr-EDTA plasma clearance were made in 50 patients with severe chronic renal failure. Based on these data two calculation methods were attempted using one plasma sample drawn 24 h after injection of 51Cr-EDTA. One of the methods used the 'one...... at zero-time was derived from injected dose and body surface area. This method might provide values 1.5 ml/min below or 0.8 ml/min above the established method of 51Cr-EDTA plasma clearance, which would be acceptable for clinical purposes. It is concluded that exact plasma clearance of 51Cr-EDTA in severe...... renal dysfunction (estimated clearance values below 21 ml/min) may be determined with adequate precision by one plasma sample drawn at 24 h after injection of the tracer without sampling at 5 h. This appears to be a very practical simplification....

  10. Formation of nitridotechnetium(VI) μ-oxo dimer complexes with EDTA and EDDA

    International Nuclear Information System (INIS)

    Takayama, T.; Kani, Y.; Sekine, T.; Kudo, H.; Yoshihara, K.

    1995-01-01

    Reactions of [ 99 TcNCl 4 ] - with ethylenediaminetetraacetic acid 4 (ETDA) and ethylenediamine-N,N'-diacetic acid (EDDA) in a mixture of water and acetone gave Tc VI N-EDTA and Tc VI N-EDTA complexes. The infrared spectra of both reaction products showed the existence of the Tc≡N and C=O groups. The elemental analysis indicated the 1:1 TcN-ligand ratio in the EDTA and EDDA complexes. Electrophoresis showed that the Tc VI -EDTA complex was an anionic species in a perchlorate solution. For the Tc VI N-EDDA complex, neutral and anionic species were formed, depending on the pH of the solution. Formation of the μ-oxo dimer complexes was suggested from the UV-Vis absorption spectra. (author) 11 refs.; 4 figs.; 1 tab

  11. Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

    Directory of Open Access Journals (Sweden)

    Lilian Terezinha de Queiroz Leite

    1996-10-01

    Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.

  12. Zinc species distribution in EDTA-extract residues of zinc-contaminated soil

    International Nuclear Information System (INIS)

    Chang, S.-H.; Wei, Y.-L.; Wang, H. Paul

    2007-01-01

    Soil sample from a site heavily contaminated with >10 wt.% zinc is sampled and extracted with aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) that is a reagent frequently used to extract heavy metals in soil remediation. Three liquid/soil ratios (5/1, 20/1, and 100/1) were used in the extracting experiment. The molecular environment of the residual Zn in the EDTA-extract residues of zinc-contaminated soil is investigated with XANES technique. The results indicate that EDTA does not show considerable preference of chelating for any particular Zn species during the extraction. Zn species distribution in the sampled soil is found to resemble that in all EDTA-extract residues; Zn(OH) 2 is determined as the major zinc species (60-70%), seconded by organic zinc (21-26%) and zinc oxide (9-14%)

  13. Late calcium EDTA rescues hippocampal CA1 neurons from global ischemia-induced death.

    Science.gov (United States)

    Calderone, Agata; Jover, Teresa; Mashiko, Toshihiro; Noh, Kyung-min; Tanaka, Hidenobu; Bennett, Michael V L; Zukin, R Suzanne

    2004-11-03

    Transient global ischemia induces a delayed rise in intracellular Zn2+, which may be mediated via glutamate receptor 2 (GluR2)-lacking AMPA receptors (AMPARs), and selective, delayed death of hippocampal CA1 neurons. The molecular mechanisms underlying Zn2+ toxicity in vivo are not well delineated. Here we show the striking finding that intraventricular injection of the high-affinity Zn2+ chelator calcium EDTA (CaEDTA) at 30 min before ischemia (early CaEDTA) or at 48-60 hr (late CaEDTA), but not 3-6 hr, after ischemia, afforded robust protection of CA1 neurons in approximately 50% (late CaEDTA) to 75% (early CaEDTA) of animals. We also show that Zn2+ acts via temporally distinct mechanisms to promote neuronal death. Early CaEDTA attenuated ischemia-induced GluR2 mRNA and protein downregulation (and, by inference, formation of Zn2+-permeable AMPARs), the delayed rise in Zn2+, and neuronal death. These findings suggest that Zn2+ acts at step(s) upstream from GluR2 gene downregulation and implicate Zn2+ in transcriptional regulation and/or GluR2 mRNA stability. Early CaEDTA also blocked mitochondrial release of cytochrome c and Smac/DIABLO (second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein-binding protein with low pI), caspase-3 activity (but not procaspase-3 cleavage), p75NTR induction, and DNA fragmentation. These findings indicate that CaEDTA preserves the functional integrity of the mitochondrial outer membrane and arrests the caspase death cascade. Late injection of CaEDTA at a time when GluR2 is downregulated and caspase is activated inhibited the delayed rise in Zn2+, p75NTR induction, DNA fragmentation, and cell death. The finding of neuroprotection by late CaEDTA administration has striking implications for intervention in the delayed neuronal death associated with global ischemia.

  14. The science of adaptation. A framework for assessment

    International Nuclear Information System (INIS)

    Smit, B.; Burton, I.; Street, R.; Klein, R.J.T.; Maciver, D.C.

    1999-01-01

    This paper outlines what is meant by 'adaptation' to climate change, and how it might be addressed in the IPCC Assessments. Two roles of adaptation in the climate change field are identified: adaptation as part of impact assessment (where the key question is: what adaptations are likely?), and adaptation as part of the policy response (where the central question is: what adaptations are recommended?). The concept of adaptation has been adopted in several fields including climate impact assessment and policy development, risk management, and natural hazards research. A framework for systematically defining adaptations is based on three questions: (1) adaptation to what? (2) who or what adapts? and (3) how does adaptation occur? The paper demonstrates that, for adaptation purposes, climate extremes and variability are integral parts of climate change, along with shifts in mean conditions. Attributes for differentiating adaptations include purposefulness, timing, temporal and spatial scope, effects, form and performance. The framework provides a guide for the treatment of adaptation in the IPCC assessments, both in the assessment of impacts and in the evaluation of adaptive policy options. 64 refs

  15. NASA and the National Climate Assessment: Promoting awareness of NASA Earth science

    Science.gov (United States)

    Leidner, A. K.

    2014-12-01

    NASA Earth science observations, models, analyses, and applications made significant contributions to numerous aspects of the Third National Climate Assessment (NCA) report and are contributing to sustained climate assessment activities. The agency's goal in participating in the NCA was to ensure that NASA scientific resources were made available to understand the current state of climate change science and climate change impacts. By working with federal agency partners and stakeholder communities to develop and write the report, the agency was able to raise awareness of NASA climate science with audiences beyond the traditional NASA community. To support assessment activities within the NASA community, the agency sponsored two competitive programs that not only funded research and tools for current and future assessments, but also increased capacity within our community to conduct assessment-relevant science and to participate in writing assessments. Such activities fostered the ability of graduate students, post-docs, and senior researchers to learn about the science needs of climate assessors and end-users, which can guide future research activities. NASA also contributed to developing the Global Change Information System, which deploys information from the NCA to scientists, decision makers, and the public, and thus contributes to climate literacy. Finally, NASA satellite imagery and animations used in the Third NCA helped the pubic and decision makers visualize climate changes and were frequently used in social media to communicate report key findings. These resources are also key for developing educational materials that help teachers and students explore regional climate change impacts and opportunities for responses.

  16. Assessing nano cellulose developments using science and technology indicators

    International Nuclear Information System (INIS)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues

    2013-01-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  17. Assessing nanocellulose developments using science and technology indicators

    Directory of Open Access Journals (Sweden)

    Douglas Henrique Milanez

    2013-06-01

    Full Text Available This research aims to examine scientific and technological trends of developments in nanocellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nanocellulose activity indicators were compared to nanotechnology and other selected nanomaterials. Scientific and technological future developments in nanocellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nanocellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nanocellulose development and the extrapolation growth curves suggested that nanocellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nanocellulose S&T advances in the coming years.

  18. Assessing nano cellulose developments using science and technology indicators

    Energy Technology Data Exchange (ETDEWEB)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues, E-mail: douglasmilanez@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Nucleo de Informacao Tecnologica em Materiais. Dept. de Engenharia de Materiais

    2013-11-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  19. Potentiometric determination of sulfate with EDTA and the cupric-selective electrode

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1976-11-01

    Sulfate was indirectly determined by precipitating sulfate as BaSO 4 and then dissolving BaSO 4 in excess ammoniacal EDTA. The excess EDTA was titrated potentiometrically with La 3+ . A cupric-selective electrode was used to detect the end point. About 10 -3 M SO 4 2- was determined in 3M HCl solutions of metal oxides with a relative standard deviation of 3.5 percent and a bias of +4 percent

  20. Effects of Na2CaEDTA on lead deposits in rabbit osseous tissue

    International Nuclear Information System (INIS)

    Doniec, J.; Trojanowska, B.; Trzcinka-Ochocka, M.; Garlicka, I.

    1983-01-01

    Radiochemical and autoradiographic methods were used for 210 Pb determination after Na 2 CaEDTA administration to rabbits. 210 Pb was determined in soft tissues, compact and trabecular bones and growing microareas on the endosteum of the long bone. After Na 2 CaEDTA injection lead was depleted from 'new' deposits mainly on the growing surface of both trabecular and compact bones. (Auth.)

  1. Implementing Curriculum-Embedded Formative Assessment in Primary School Science Classrooms

    Science.gov (United States)

    Hondrich, Annika Lena; Hertel, Silke; Adl-Amini, Katja; Klieme, Eckhard

    2016-01-01

    The implementation of formative assessment strategies is challenging for teachers. We evaluated teachers' implementation fidelity of a curriculum-embedded formative assessment programme for primary school science education, investigating both material-supported, direct application and subsequent transfer. Furthermore, the relationship between…

  2. Designing Interdisciplinary Assessments in Sciences for College Students: An Example on Osmosis

    Science.gov (United States)

    Shen, Ji; Liu, Ou Lydia; Sung, Shannon

    2014-01-01

    College science education needs to foster students' habit of mind beyond disciplinary constraints. However, little research has been devoted to assessing students' interdisciplinary understanding. To address this problem, we formed a team of experts from different disciplines to develop interdisciplinary assessments that target…

  3. Full-Cycle Assessment of Critical Thinking in an Ethics and Science Course

    Science.gov (United States)

    Blue, Jennifer; Taylor, Beverley; Yarrison-Rice, Jan

    2008-01-01

    Enhancing critical thinking skills for undergraduate students is important across the curriculum and between disciplines. We report on a method of improving critical thinking skills, which was studied through an Ethics and Science First-Year Seminar course. We used full cycle assessment over a three-year period to assess students' development and…

  4. Drawing and Writing in Digital Science Notebooks: Sources of Formative Assessment Data

    Science.gov (United States)

    Shelton, Angi; Smith, Andrew; Wiebe, Eric; Behrle, Courtney; Sirkin, Ruth; Lester, James

    2016-01-01

    Formative assessment strategies are used to direct instruction by establishing where learners' understanding is, how it is developing, informing teachers and students alike as to how they might get to their next set of goals of conceptual understanding. For the science classroom, one rich source of formative assessment data about scientific…

  5. TIMSS 2011 Science Assessment Results: A Review of Ghana's Performance

    Science.gov (United States)

    Buabeng, Isaac; Owusu, Kofi Acheaw; Ntow, Forster Danso

    2014-01-01

    This paper reviews Ghana's performance in the TIMSS 2011 survey in comparison with other African and some high performing countries which participated in the TIMSS assessment. Students' achievement in the science content areas assessed were summarized and teacher preparation constructs of teachers of the students who took part in the assessment…

  6. The effect of vacuum packaging, EDTA, oregano and thyme oils on the microbiological quality of chicken's breast.

    Science.gov (United States)

    Pavelková, Adriana; Kačániová, Miroslava; Horská, Elena; Rovná, Katarína; Hleba, Lukáš; Petrová, Jana

    2014-10-01

    The effect of ethylenediaminetetraacetate (EDTA), oregano (Origanum vulgare) and thyme (Thymus vulgaris) oils, on the chicken breast fillets was examined in this study. The chicken breast fillets were stored under vacuum packaging (VP), at 4 ± 0.5 °C for a period of 18 days. There were used the following treatments of chicken breast fillets: Air-packaged (AC, control samples), vacuum-packaged (VPC, control samples), VP with EDTA solution 1.50% w/w (VPEC, control samples), VP with oregano oil 0.20% v/w (VP + O) and VP with thyme oil 0.20% v/w, (VP + T). The quality assessment for vacuum packaging of the product in accordance with the terms above and EDTA treatment, oregano and thyme oil was established by microbiological analyzes. The microbiological properties as the total viable counts on Plate Count Agar, after incubation for 2 days at 37 °C and coliform bacteria on Violet Red Bile Glucose agar incubated at 37 °C for 24 h, lactobacilli on Rogosa and Sharpe agar after incubation 48-78 h at 37 °C in an aerobic atmosphere supplemented with carbon dioxide (5% CO2) and Pseudomonas aeruginosa on Pseudomonas Isolation agar (PIA, Oxoid, UK) after incubation at 48 h at 35 °C were monitored. The using of oregano, thyme oil and EDTA with combination of vacuum packaging has significant effects to reduction of all followed groups of microorganisms compared with control group without vacuum packaging and untreated control group. The natural preservatives can be used as alternatives to chemical additives which could extend the meat and meat products shelf life. The knowledge about them can have an important economic feedback by reducing losses attributed to spoilage and by allowing the products to reach distant and new markets. This study shows how using of natural antimicrobials can extend the shelf-life of the meat product. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Evaluating design-based formative assessment practices in outdoor science teaching

    DEFF Research Database (Denmark)

    Hartmeyer, Rikke; Stevenson, Matthew Peter; Bentsen, Peter

    2016-01-01

    Background and purpose: Research in formative assessment often pays close attention to the strategies which can be used by teachers. However, less emphasis in the literature seems to have been paid to study the application of formative assessment designs in practice. In this paper, we argue...... that a formative assessment design that we call Eva-Mapping, which is developed on the principles of design-based research, can be a productive starting point for disseminating and further developing formative assessment practices in outdoor science teaching. Sample, design and methods: We conducted an evaluation...... of the design, based on video-elicited focus group interviews with two groups of experienced science teachers. Both groups consisted of teachers who taught science outside the classroom on a regular basis. These groups watched identical video sequences which were recorded during lessons in which teachers...

  8. Influence of EDTA on lead transportation and accumulation by Sedum alfredii Hance

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dan [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education; Zhejiang Forestry College, Lin' an (China). School of Tourism and Health; Li Ting-Qiang; Yang Xiao-E; Islam, E.; Jin Xiao-Fen; Mahmood, Q. [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education

    2007-09-15

    Hydroponics and pot experiments were conducted to study the effects of ethylenediaminetetraacetic acid (EDTA) on Pb transportation and accumulation by two contrasting ecotypes of Sedum alfredii Hance. In hydroponics experiments, the accumulating ecotype (AE) showed more ability to tolerate Pb toxicitycompared with the non-accumulating ecotype (NAE). When treated with equimolar mixtures of EDTA and Pb, maximum Pb accumulation occurred without any phytotoxicity symptoms. Pot experiments with Pb contents of 400 mg kg{sup -1} showed that 5 mm EDTA is the optimum dose for the phytoextraction of soils contaminated with relatively low Pb levels; in contrast, increasing EDTA addition resulted in increased Pb accumulation in the shoots of AE in soils with high Pb content (1200 mg kg{sup -1}). The post-harvest effects of EDTA on available Pb were strong compared with those without addition of EDTA (CK). Within the initial 7 days almost no differences of water-soluble Pb were noted in soils contaminated with both levels of Pb but after 2 weeks, water-soluble Pb started to decrease significantlycompared with before. Considering the toxicity and biodegradability of synthetic chelators, it can be concluded that the chelate-assisted technique is more suitable for soils contaminated with low Pb levels and to avoid environment risks; a suitable dose of chelators must be considered before application. (orig.)

  9. EDTA treatment alters protein glycosylation in the cellular slime mold Dictyostelium discoideum

    International Nuclear Information System (INIS)

    West, C.M.; Brownstein, S.A.

    1988-01-01

    The authors have found that treatment of cells with EDTA resulted in the accumulation of lower molecular weight forms of two cell-type-specific glycoproteins. These new glycoproteins lacked a developmentally regulated glycoantigen defined by monoclonal antibody 54.2. Since EDTA dissociated the cells, the possible involvement of cell separation was tested by immobilizing cells in soft agarose. Glycoantigen expression on these proteins was found to be dependent on cAMP and high oxygen tension but not on cell contact, and was reversibly sensitive to EDTA regardless of the state of cell association. The EDTA effect was mimicked by other soluble, but not particulate, membrane impermeable chelators, could be completed by Zn 2+ better than Mg 2+ , and appeared to involve an intracellular mechanism. Studies with [ 14 C]EDTA showed that EDTA equilibrated with a cellular compartment in a temperature-dependent, Zn 2+ -insensitive fashion with half-time kinetics of loading and unloading of 30-40 min. The data suggest that this step in glycosylation, which was found to be delayed 1 or more hours subsequent to protein synthesis, involves an intracellular, transition metal-ion-dependent process which can be modulated by chelators entering the cell through the endocytic pathway

  10. Effect of NaFeEDTA-fortified soy sauce on zinc absorption in children.

    Science.gov (United States)

    Li, Min; Wu, Jinghuan; Ren, Tongxiang; Wang, Rui; Li, Weidong; Piao, Jianhua; Wang, Jun; Yang, Xiaoguang

    2015-03-01

    NaFeEDTA has been applied in many foods as an iron fortificant and is used to prevent iron deficiency in Fe-depleted populations. In China, soy sauce is fortified with NaFeEDTA to control iron deficiency. However, it is unclear whether Fe-fortified soy sauce affects zinc absorption. To investigate whether NaFeEDTA-fortified soy sauce affects zinc absorption in children, sixty children were enrolled in this study and randomly assigned to three groups (10 male children and 10 female children in each group). All children received daily 3 mg of (67)Zn and 1.2 mg of dysprosium orally, while the children in the three groups were supplemented with NaFeEDTA-fortified soy sauce (6 mg Fe, NaFeEDTA group), FeSO₄-fortified soy sauce (6 mg Fe, FeSO₄ group), and no iron-fortified soy sauce (control group), respectively. Fecal samples were collected during the experimental period and analyzed for the Zn content, (67)Zn isotope ratio and dysprosium content. The Fe intake from NaFeEDTA-fortified and FeSO₄-fortified groups was significantly higher than that in the control group (P sauce does not affect Zn bioavailability in children.

  11. Enhanced degradation of 4-nitrophenol by microwave assisted Fe/EDTA process

    Energy Technology Data Exchange (ETDEWEB)

    Liu Bo, E-mail: yongboliu@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Li Song, E-mail: ls8214@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhao Yongjun, E-mail: zyjun2007@126.com [State Key Laboratory of Pollution Control and Resource Reuse, School of Life Science, Nanjing University, Nanjing 210093 (China); Wu Wenfei, E-mail: feibanana6@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhang Xuxiang, E-mail: zhangxx@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Life Science, Nanjing University, Nanjing 210093 (China); Gu Xueyuan, E-mail: xygu@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Li Ruihua, E-mail: liruihua@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Yang Shaogui, E-mail: ysg420@sina.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2010-04-15

    A microwave assisted zero-valent iron oxidation process was studied in order to investigate the synergetic effects of MW irradiation on Fe/EDTA system (Fe/EDTA/MW) treated 4-nitrophenol (4-NP) from aqueous solution. The results indicated that the thermal effect of microwave improved the removal effect of 4-NP and TOC through raising the temperature of the system, as well as the non-thermal effect generated by the interaction between the microwave and the Fe resulting in an increase in the hydrophobic character of Fe surface. During the degradation of 4-NP in Fe/EDTA/MW system, the optimum value for MW power, Fe, EDTA dosage was 400 W, 2 g and 0.4 mM, respectively. The possible pathway for degrading the 4-NP was proposed based on GC/MS and HPLC analysis of the degradation intermediates. The concentration change course of the main bio-refractory by-products, the aminophenol formed in the degradation of 4-NP suggested a more efficient degradation and mineralization in Fe/EDTA/MW system. Finally, BOD{sub 5}/COD{sub Cr} of the solution increased from 0.237 to 0.635 after reaction for 18 min, indicating that the biodegradability of wastewater was greatly improved by Fe/EDTA/MW system and would benefit to further treatment by biochemical methods.

  12. Enhanced degradation of 4-nitrophenol by microwave assisted Fe/EDTA process

    International Nuclear Information System (INIS)

    Liu Bo; Li Song; Zhao Yongjun; Wu Wenfei; Zhang Xuxiang; Gu Xueyuan; Li Ruihua; Yang Shaogui

    2010-01-01

    A microwave assisted zero-valent iron oxidation process was studied in order to investigate the synergetic effects of MW irradiation on Fe/EDTA system (Fe/EDTA/MW) treated 4-nitrophenol (4-NP) from aqueous solution. The results indicated that the thermal effect of microwave improved the removal effect of 4-NP and TOC through raising the temperature of the system, as well as the non-thermal effect generated by the interaction between the microwave and the Fe resulting in an increase in the hydrophobic character of Fe surface. During the degradation of 4-NP in Fe/EDTA/MW system, the optimum value for MW power, Fe, EDTA dosage was 400 W, 2 g and 0.4 mM, respectively. The possible pathway for degrading the 4-NP was proposed based on GC/MS and HPLC analysis of the degradation intermediates. The concentration change course of the main bio-refractory by-products, the aminophenol formed in the degradation of 4-NP suggested a more efficient degradation and mineralization in Fe/EDTA/MW system. Finally, BOD 5 /COD Cr of the solution increased from 0.237 to 0.635 after reaction for 18 min, indicating that the biodegradability of wastewater was greatly improved by Fe/EDTA/MW system and would benefit to further treatment by biochemical methods.

  13. Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers

    Science.gov (United States)

    Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

    2017-01-01

    A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm2 and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS). PMID:28754016

  14. Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers.

    Science.gov (United States)

    Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

    2017-07-21

    A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm² and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS).

  15. New EDTA determination method based on ion chromatography with suppressed conductimetric detection

    International Nuclear Information System (INIS)

    Gyoergy Patzay; Yahya Ramadan; Csilla Tonko

    2014-01-01

    A novel direct method for the determination of EDTA in alkaline radioactive evaporator residue solution was developed and validated based on ion chromatography with suppressed conductimetric detection and anion exchange columns (A Supp 4, 4 mm × 250 mm and A Supp 5, 4 mm × 150 mm). The yttrium-EDTA complex resulted one single chromatographic peak in the eluent and allowed the correct determination of EDTA in an alkaline, high concentration radioactive waste water. Depending on coexisting substances, suitable eluent is 10.0 mM carbonate buffer/pH 10.6 or 10.75 (t R ,Y-EDTA = 7.01 and 6.4 min, respectively). For 10.0 mM carbonate buffer/pH 10.6 and isocratic flow rate of 1.0 cm 3 /min, a linear calibration curve was obtained from 5 to 40 mg/dm 3 (r > 0.999) EDTA. Good resolution was achieved from commonly coexisting anions (chloride, nitrite, nitrate, sulphate, phosphate, bromide and citrate). The developed simple ion chromatographic method was applied for the assay of EDTA in various radioactive alkaline solutions. (author)

  16. Immunological effects of CaEDTA injection: observations in two lead workers.

    Science.gov (United States)

    Sata, F; Araki, S; Sakai, T; Nakata, A; Yamashita, K; Morita, Y; Tanigawa, T; Miki, A

    1997-12-01

    To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

  17. Assessing High School Student Learning on Science Outreach Lab Activities

    Science.gov (United States)

    Thomas, Courtney L.

    2012-01-01

    The effect of hands-on laboratory activities on secondary student learning was examined. Assessment was conducted over a two-year period, with 262 students participating the first year and 264 students the second year. Students took a prequiz, performed a laboratory activity (gas chromatography of alcohols, or photosynthesis and respiration), and…

  18. Southern forest resource assessment: Conducting science in the public eye

    Science.gov (United States)

    John G. Greis; David N. Wear

    2002-01-01

    Questions about the long-term sustainability of southern forest benefits, including wildlife habitat, water quality, and timber supply, prompted this regional assessment and guided the process by which it was conducted. SFRA’s final report is descriptive—not prescriptive—and is intended to inform debate and policymaking in technically defensible, unbiased, and...

  19. Hiroshima and Nagasaki: from fear through science to risk assessment

    International Nuclear Information System (INIS)

    Sugahara, T.

    1996-01-01

    This presentation summarises the data of Japanese epidemiological studies in the light of the recent progresses made in radiation biology which do not support the present radiation paradigm for cancer risk assessment at low doses. The possible paradigm shift and its effect on the dose limits for protection of individuals is also discussed. (author). 27 refs., 1 tab

  20. Development and exemplification of a model for Teacher Assessment in Primary Science

    Science.gov (United States)

    Davies, D. J.; Earle, S.; McMahon, K.; Howe, A.; Collier, C.

    2017-09-01

    The Teacher Assessment in Primary Science project is funded by the Primary Science Teaching Trust and based at Bath Spa University. The study aims to develop a whole-school model of valid, reliable and manageable teacher assessment to inform practice and make a positive impact on primary-aged children's learning in science. The model is based on a data-flow 'pyramid' (analogous to the flow of energy through an ecosystem), whereby the rich formative assessment evidence gathered in the classroom is summarised for monitoring, reporting and evaluation purposes [Nuffield Foundation. (2012). Developing policy, principles and practice in primary school science assessment. London: Nuffield Foundation]. Using a design-based research (DBR) methodology, the authors worked in collaboration with teachers from project schools and other expert groups to refine, elaborate, validate and operationalise the data-flow 'pyramid' model, resulting in the development of a whole-school self-evaluation tool. In this paper, we argue that a DBR approach to theory-building and school improvement drawing upon teacher expertise has led to the identification, adaptation and successful scaling up of a promising approach to school self-evaluation in relation to assessment in science.

  1. Rubric Assessment on Science and Creative Thinking Skills of Students

    Science.gov (United States)

    Ratnasusanti, H.; Ana, A.; Nurafiati, P.; Umusyaadah, L.

    2018-02-01

    The result of the monitoring and evaluation of the latest Indonesian curriculum (the 2013 curriculum) implementation at junior high school level year of 2014 showed that one of the difficult things that learners had in implementation 2013 curriculum is doing the result. The characteristic of applying the 2013 curriculum is to emphasize the modern pedagogic dimension of learning, which is using scientific approach, which requires learners to have highlevel thinking skills, one of which is creative thinking skills. The aims of this research is to implement performance assessment in measuring the creative thinking of junior high school students on subject Prakarya. The form of the main performance assessment is the task and assessment criteria. The experimental method that been used is the Quasi Experiment with Non-Equivalent Design Group Research. Population in this study is the students of VIII class of junior high school in Bandung, Indonesia which consists of six classes. And two classes are selected for the sample from that six classes and VIII A class were chosen, while VIII F class has been chosen as control class. The result of this research showed that the rubics of performance assessment can be measure or identify the creative thinking skill, its prove by the result of pre-test dan post-test are more dominant. In material of identification student’s creative thinking skills are reached an average 85 compare 79 with the control class. while in the presentation the experimental class got an average of 85 bigger than the control class which only reached 79.

  2. Effect of PDGF-BB combined with EDTA gel on adhesion and proliferation to the root surface.

    Science.gov (United States)

    Belal, Mahmoud Helmy; Watanabe, Hisashi; Ichinose, Shizuko; Ishikawa, Isao

    2012-07-01

    Periodontal regeneration using EDTA or PDGF showed promising results, but the effect of combined application was still unclear. This study aimed to verify the effect of EDTA and/or PDGF application on root adhesion and proliferation of PDL fibroblast cells. Eighty specimens were prepared from forty periodontitis teeth and made five groups: (1) diseased (untreated), (2) SRP (scaling root planing), (3) EDTA (24%), (4) PDGF (25 ng/ml) and (5) Combined application of EDTA and PDGF. Periodontal ligament cells were cultured on the above conditioned dentin plate, and SEM examination was preformed and cells were counted within a representative standard area for both cell morphology and density. All groups including untreated showed significantly increase of adhered cells from baseline to 7 days. Among them, rate of increase was much higher in EDTA, PDGF, and combined groups. ANOVA test indicated that the number of cells in PDGF and combined groups was significantly higher than diseased group at 1 day. On day 7, PDGF and combined groups showed significantly higher number of adhesion cells than that found in the diseased, SRP and EDTA groups. Thus, root conditioning with EDTA enhanced cell adhesion more than SRP alone. There was no significant difference of cell number between PDGF and combined group. Combined application of EDTA and PDGF increased significantly PDL cell adhesion than EDTA alone. PDGF alone, however, also showed comparable effect to combined application at all periods. Thus, synergistic effect between PDGF and EDTA was not observed.

  3. Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

    Science.gov (United States)

    Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

    2017-03-01

    The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Sustained Assessment Metadata as a Pathway to Trustworthiness of Climate Science Information

    Science.gov (United States)

    Champion, S. M.; Kunkel, K.

    2017-12-01

    The Sustained Assessment process has produced a suite of climate change reports: The Third National Climate Assessment (NCA3), Regional Surface Climate Conditions in CMIP3 and CMIP5 for the United States: Differences, Similarities, and Implications for the U.S. National Climate Assessment, Impacts of Climate Change on Human Health in the United States: A Scientific Assessment, The State Climate Summaries, as well as the anticipated Climate Science Special Report and Fourth National Climate Assessment. Not only are these groundbreaking reports of climate change science, they are also the first suite of climate science reports to provide access to complex metadata directly connected to the report figures and graphics products. While the basic metadata documentation requirement is federally mandated through a series of federal guidelines as a part of the Information Quality Act, Sustained Assessment products are also deemed Highly Influential Scientific Assessments, which further requires demonstration of the transparency and reproducibility of the content. To meet these requirements, the Technical Support Unit (TSU) for the Sustained Assessment embarked on building a system for not only collecting and documenting metadata to the required standards, but one that also provides consumers unprecedented access to the underlying data and methods. As our process and documentation have evolved, the value of both continue to grow in parallel with the consumer expectation of quality, accessible climate science information. This presentation will detail the how the TSU accomplishes the mandated requirements with their metadata collection and documentation process, as well as the technical solution designed to demonstrate compliance while also providing access to the content for the general public. We will also illustrate how our accessibility platforms guide consumers through the Assessment science at a level of transparency that builds trust and confidence in the report

  5. Challenges and Opportunities for Integrating Social Science Perspectives into Climate and Global Change Assessments

    Science.gov (United States)

    Larson, E. K.; Li, J.; Zycherman, A.

    2017-12-01

    Integration of social science into climate and global change assessments is fundamental for improving understanding of the drivers, impacts and vulnerability of climate change, and the social, cultural and behavioral challenges related to climate change responses. This requires disciplinary and interdisciplinary knowledge as well as integrational and translational tools for linking this knowledge with the natural and physical sciences. The USGCRP's Social Science Coordinating Committee (SSCC) is tasked with this challenge and is working to integrate relevant social, economic and behavioral knowledge into processes like sustained assessments. This presentation will discuss outcomes from a recent SSCC workshop, "Social Science Perspectives on Climate Change" and their applications to sustained assessments. The workshop brought academic social scientists from four disciplines - anthropology, sociology, geography and archaeology - together with federal scientists and program managers to discuss three major research areas relevant to the USGCRP and climate assessments: (1) innovative tools, methods, and analyses to clarify the interactions of human and natural systems under climate change, (2) understanding of factors contributing to differences in social vulnerability between and within communities under climate change, and (3) social science perspectives on drivers of global climate change. These disciplines, collectively, emphasize the need to consider socio-cultural, political, economic, geographic, and historic factors, and their dynamic interactions, to understand climate change drivers, social vulnerability, and mitigation and adaptation responses. They also highlight the importance of mixed quantitative and qualitative methods to explain impacts, vulnerability, and responses at different time and spatial scales. This presentation will focus on major contributions of the social sciences to climate and global change research. We will discuss future directions for

  6. Assessing Data Quality in Emergent Domains of Earth Sciences

    Science.gov (United States)

    Darch, P. T.; Borgman, C.

    2016-12-01

    As earth scientists seek to study known phenomena in new ways, and to study new phenomena, they often develop new technologies and new methods such as embedded network sensing, or reapply extant technologies, such as seafloor drilling. Emergent domains are often highly multidisciplinary as researchers from many backgrounds converge on new research questions. They may adapt existing methods, or develop methods de novo. As a result, emerging domains tend to be methodologically heterogeneous. As these domains mature, pressure to standardize methods increases. Standardization promotes trust, reliability, accuracy, and reproducibility, and simplifies data management. However, for standardization to occur, researchers must be able to assess which of the competing methods produces the highest quality data. The exploratory nature of emerging domains discourages standardization. Because competing methods originate in different disciplinary backgrounds, their scientific credibility is difficult to compare. Instead of direct comparison, researchers attempt to conduct meta-analyses. Scientists compare datasets produced by different methods to assess their consistency and efficiency. This paper presents findings from a long-term qualitative case study of research on the deep subseafloor biosphere, an emergent domain. A diverse community converged on the study of microbes in the seafloor and those microbes' interactions with the physical environments they inhabit. Data on this problem are scarce, leading to calls for standardization as a means to acquire and analyze greater volumes of data. Lacking consistent methods, scientists attempted to conduct meta-analyses to determine the most promising methods on which to standardize. Among the factors that inhibited meta-analyses were disparate approaches to metadata and to curating data. Datasets may be deposited in a variety of databases or kept on individual scientists' servers. Associated metadata may be inconsistent or hard to

  7. The Astronomy and Space Science Concept Inventory: Assessment Instruments Aligned with the K-12 National Science Standards

    Science.gov (United States)

    Sadler, Philip M.

    2011-01-01

    We report on the development of an item test bank and associated instruments based on those K-12 national standards which involve astronomy and space science. Utilizing hundreds of studies in the science education research literature on student misconceptions, we have constructed 211 unique items that measure the degree to which students abandon such ideas for accepted scientific views. Piloted nationally with 7599 students and their 88 teachers spanning grades 5-12, the items reveal a range of interesting results, particularly student difficulties in mastering the NRC Standards and AAAS Benchmarks. Teachers generally perform well on items covering the standards of the grade level at which they teach, exhibiting few misconceptions of their own. Teachers dramatically overestimate their students’ performance, perhaps because they are unaware of their students’ misconceptions. Examples are given showing how the developed instruments can be used to assess the effectiveness of instruction and to evaluate the impact of professional development activities for teachers.

  8. Technology assessment and social science research on technology

    International Nuclear Information System (INIS)

    Thienen, V. von

    1983-01-01

    In a first step this bibliography wants to overcome the want of systematic scientific data compilations and evaluations of experiences in studies on technology assessment. It concentrates on the social and political aspects of the development of technologies and the decision on their utilization by presenting titles which have been published in English- and German-speaking countries in the past decade. The bibliography is divided into various chapters and subchapters. The index part contains authors' indexes and publishers' indexes, subject indexes, other bibliographies and selected periodicals. (orig.) With 1647 refs [de

  9. Creating scientists teaching and assessing science practice for the NGSS

    CERN Document Server

    Moore, Christopher

    2018-01-01

    Teach students to reason like scientists. This practical new book provides a clear framework for helping students develop scientific thinking so they are not just memorizing content but are becoming engaged in the real work scientists do. You'll learn how to teach students to analyse scientific testing, to understand if something caused something else, and to understand the value of evidence. The book offers ideas for lesson plans and assessments and also features reproducible tools and handouts that you can use in the classroom immediately.

  10. Terrain Safety Assessment in Support of the Mars Science Laboratory Mission

    Science.gov (United States)

    Kipp, Devin

    2012-01-01

    In August 2012, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems by delivering the largest and most capable rover to date to the surface of Mars. The process to select the MSL landing site took over five years and began with over 50 initial candidate sites from which four finalist sites were chosen. The four finalist sites were examined in detail to assess overall science merit, EDL safety, and rover traversability on the surface. Ultimately, the engineering assessments demonstrated a high level of safety and robustness at all four finalist sites and differences in the assessment across those sites were small enough that neither EDL safety nor rover traversability considerations could significantly discriminate among the final four sites. Thus the MSL landing site at Gale Crater was selected from among the four finalists primarily on the basis of science considerations.

  11. The effects of professional development related to classroom assessment on student achievement in science

    Science.gov (United States)

    Mazzie, Dawn Danielle

    This study investigated the relationship between students' standardized test scores in science and (a) increases in teacher assessment literacy and (b) teacher participation in a Teacher Quality Research (TQR) project on classroom assessment. The samples for these studies were teachers from underperforming schools who volunteered to take part in a professional development program in classroom assessment. School groups were randomly assigned to the treatment group. For Study 1, teachers in the treatment received professional development in classroom assessment from a trained assessment coach. Teachers in the control received no professional development. For Study 2, teachers in Treatment 1 received professional development in classroom assessment from a trained assessment coach and teachers in Treatment 2 received professional development in classroom assessment from a facilitator with one day of training. Teachers in both groups completed a measure of assessment literacy, the Teacher Quality Research Test of Assessment Literacy Skills (TQR_TALS), prior to the beginning and then again at the conclusion of the four month professional development program. A hierarchical linear model (HLM) analysis was conducted to determine the relationship between students' standardized test scores in science and (a) increases in teacher assessment literacy and (b) teacher TQR status. Based upon these analyses, the professional development program increased teachers' assessment literacy skills; however, the professional development had no significant impact on students' achievement.

  12. What are the effects of self-assessment preparation in a middle school science classroom?

    Science.gov (United States)

    Severance, Sara E.

    2012-02-01

    This research was conducted by an urban middle school science teacher who sought to investigate the effects of self-assessment on student performance. A group of students were asked to give themselves a score on each learning target assessed in class and to provide evidence for their decision. Student self-assessment scores were compared to scores given by the teacher to see if students who accurately assessed their own learning scored higher on final assessments than students who did not. Assessment scores between groups of students who completed the self-assessment preparation and students who did not were also analyzed. The data indicates no correlation between the ability to self-assess and achievement. However, further implications on self-assessment at the secondary level are discussed.

  13. Effectiveness of EDTA and EDTA-T brushingm on the removal of root surface smear layer Efeito do EDTA e EDTA-T aplicado de forma ativa na remoção de "smear layer" de superfícies radiculares

    Directory of Open Access Journals (Sweden)

    José Eduardo Cezar Sampaio

    2003-12-01

    Full Text Available The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon gel in different concentrations (5%, 10%, 15%, 20% and 24%, using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control application of saline solution (n = 20; Group II - EDTA gel (pH 7.0 was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100; Group III - EDTA-T gel (pH 7.0 applied in the same concentrations described above (n = 100. The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test. The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p 0.05. Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.O objetivo do presente estudo foi comparar, através de microscopia eletrônica de varredura, o efeito da aplicação de gel de EDTA e de EDTA-T (texapon em diferentes concentrações (5%, 10%, 15%, 20% e 24% na remoção de "smear layer" de superfícies radiculares previamente raspadas com instrumentos manuais. Duzentos e vinte espécimes de superfícies radiculares submetidas à raspagem foram divididos em 3 grupos. Grupo I - (controle solução salina (n = 20; Grupo II - gel de EDTA (pH 7,0 nas concentrações de 5%, 10%, 15%, 20% e 24% (n = 100; Grupo III - gel de EDTA-T (pH 7,0 nas concentrações acima descritas (n = 100. As fotomicrografias obtidas foram avaliadas por um examinador calibrado através da aplicação de um índice de remoção de "smear layer", e os dados foram analisados através de análise estat

  14. How Exposure Science can be Integrated into the Assessment ...

    Science.gov (United States)

    The presentation describes ongoing research in the Rapid Exposure and Dosimetry project funded under the Chemical Safety for Sustainability Research Program of the Office of Research and Development. There is a well known need for information on human exposure to thousands of chemicals, especially with respect to route of exposure. A combination of curation of legacy data, new data collection activities, and mathematical models based both upon statistics (empirical) and mechanism are allowing chemicals to be prioritized for further exposure study. This presentation pays special attention to the opportunities presented by non-targeted screening using mass spectrometry. This is a presentation to the American College of Toxicology annual meeting in Baltimore, Maryland on November 7, 2016. This half hour presentation is part of a session on 21st Century Approaches to Assessing Food Ingredient Safety.

  15. Assessment of canine intestinal permeability, using 51Cr-labeled ethylenediaminetetraacetate

    International Nuclear Information System (INIS)

    Hall, E.J.; Batt, R.M.; Brown, A.

    1989-01-01

    The 51 Cr-labeled EDTA was validated as a suitable permeability probe in dogs for measurement of passive, unmediated diffusion across intestinal mucosa via intercellular pathways. The 51 Cr-labeled EDTA was stable in aqueous solution and did not bind to biologic tissue and fluids. After incubation of 51 Cr-labeled EDTA in isolated jejunal loops, analytic subcellular fractionation of jejunal mucosa on reorientating sucrose-density gradients was performed, and no association of 51 Cr-labeled EDTA with particulate intracellular organelles was detected. Intravenously administered 51 Cr-labeled EDTA was rapidly and completely excreted in urine. Intestinal permeability to 51 Cr-labeled EDTA after oral administration was assessed in healthy dogs. The percentage of the administered dose of 51 Cr-labeled EDTA excreted in the urine in 24 hours ranged from 2.3 to 17.6% (median, 13%)

  16. Evaluation of di-amino phenol substituted EDTA for use in radiolabelling proteins with 64Cu

    International Nuclear Information System (INIS)

    Schmidt, P.F.; Smith, S.V.; DiBartolo, N.M.

    1996-01-01

    This study involves a high yielding synthesis of a novel di-amino-phenol substituted EDTA (DAHA-EDTA) ligand and its radiolabelling chemistry with 64 Cu produced at the National Medical Cyclotron (NMC). High activity levels (up to 59.2 GBq EOB) of 64 Cu is co-produced during the production of 67 Ga from enriched 68 Zn. Waste eluent from the NMC 67 Ga production was evaporated to dryness and found to contain by products such as 57 Ni, 57 Co, 64 Cu, 67 Cu and 55 Co. A new method involving low acid concentration aqueous/organic mixtures with an anion exchange (AG 1-X8, BioRad) have been used to isolate the carrier-free 64 Cu. The specific activity of the 64 Cu (5 x 10 14 Bq/g) was found to be higher than that produce by Australian radioisotopes (ARI). The synthesis of the ligand involves the refluxing of EDTA anhydride in the presence of 4-nitro-2-amino-phenol in acetonitrile to produce the di-nitro derivative (DNHA- EDTA) in > 95% yield. The DNHA-EDTA is then reduced in the presence of activated palladium charcoal with sodium borohydride under an inert atmosphere at room temperature. The reaction mixture was acidified and the catalyst removed to obtain the final product, DAHA-EDTA. Labelling of proteins (B72.3, DD-3B6/22 and streptavidin) has been achieved with the DAHA-EDTA ligand. The reaction mixture is left to incubate for 1 h at 37 deg C and radiolabelled protein is then isolated using size exclusion chromatography

  17. Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

    Directory of Open Access Journals (Sweden)

    Lilian Terezinha de Queiroz Leite

    1996-10-01

    Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.Anticorpos monoclonais (AcM foram produzidos contra o extrato EDTA obtido de Leptospira interrogans, sorovar icterohaemorrhagiae. Pelo teste de precipitação foram caracterizados como IgM e IgG (IgGl e IgG2. A eletroforese em gel de poliacrilamida do extrato EDTA revelou diversas bandas quando corada pela prata. No "Western blot", as bandas em torno de 20 kDa reagiram com o AcM 47B4D6, foram oxidadas pelo periodato e não digeridas pela pronase, sugerindo que o determinante é de natureza carboidrato. O determinante reconhecido pelo AcM 47B4D6 estã localizado sob o envelope externo como revelado pela imunocitoquímica usando marcação com ouro coloidal. O AcM contra extrato EDTA do sorovar icterohaemorrahagiae não protegeu hamsters quando inoculados com lepstopira homóloga virulenta.

  18. Science Alternate Assessments Based on Alternate Achievement Standards (AA-AAS) during School Year 2014-2015. Synthesis Report 99

    Science.gov (United States)

    Rogers, Christopher M.; Thurlow, Martha L.; Lazarus, Sheryl S.

    2015-01-01

    Federal law requires that all students, including students with disabilities, participate in state assessments used for accountability purposes. It also requires states to assess students in several content areas, including science. Most students with disabilities take the general science assessment with or without accommodations, but a few…

  19. The role of assessment infrastructures in crafting project-based science classrooms

    Science.gov (United States)

    D'Amico, Laura Marie

    In project-based science teaching, teachers engage students in the practice of conducting meaningful investigations and explanations of natural phenomena, often in collaboration with fellow students or adults. Reformers suggest that this approach can provide students with more profitable learning experiences; but for many teachers, a shift to such instruction can be difficult to manage. As some reform-minded teachers have discovered, classroom assessment can serve as a vital tool for meeting the challenges associated with project science activity. In this research, classroom assessment was viewed as an infrastructure that both students and teachers rely upon as a mediational tool for classroom activity and communications. The study explored the classroom assessment infrastructures created by three teachers involved in the Learning through Collaborative Visualization (CoVis) Project from 1993--94 to 1995--96. Each of the three teachers under study either created a new course or radically reformulated an old one in an effort to incorporate project-based science pedagogy and supporting technologies. Data in the form of interviews, classroom observations, surveys, student work, and teacher records was collected. From these data, an interpretive case study was developed for each course and its accompanying assessment infrastructure. A set of cross-case analyses was also constructed, based upon common themes that emerged from all three cases. These themes included: the assessment challenges based on the nature of project activity, the role of technology in the teachers' assessment infrastructure designs, and the influence of the wider assessment infrastructure on their course and assessment designs. In combination, the case studies and cross-case analyses describe the synergistic relationship between the design of pedagogical reforms and classroom assessment infrastructures, as well as the effectiveness of all three assessment designs. This work contributes to research

  20. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation

    International Nuclear Information System (INIS)

    Tian Shengke; Lu Lingli; Yang Xiaoe; Huang Huagang; Brown, Patrick; Labavitch, John; Liao Haibing; He Zhenli

    2011-01-01

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO 3 ) 2 was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb 3 (PO 4 ) 2 , Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. - Research highlights: → The plants of S. alfredii are less effective in taking up Pb from the EDTA-Pb medium. → Pb is mainly localized in the vascular bundles and probably as Pb-cell wall complex. → EDTA does not increase the internal mobility of Pb within the plants of S. alfredii. → The Pb-EDTA complex could be transported and accumulated within the plants. - The plants of S. alfredii are able to transport and accumulate the Pb-EDTA complex, but are less effective in taking up Pb from the EDTA-Pb medium.

  1. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian Shengke [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Lu Lingli, E-mail: linglilulu@gmail.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe, E-mail: xyang571@yahoo.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Huang Huagang [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Brown, Patrick; Labavitch, John [Department of Plant Sciences, University of California, Davis, CA 95616 (United States); Liao Haibing [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); He Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States)

    2011-03-15

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO{sub 3}){sub 2} was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb{sub 3}(PO{sub 4}){sub 2}, Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. - Research highlights: > The plants of S. alfredii are less effective in taking up Pb from the EDTA-Pb medium. > Pb is mainly localized in the vascular bundles and probably as Pb-cell wall complex. > EDTA does not increase the internal mobility of Pb within the plants of S. alfredii. > The Pb-EDTA complex could be transported and accumulated within the plants. - The plants of S. alfredii are able to transport and accumulate the Pb-EDTA complex, but are less effective in taking up Pb from the EDTA-Pb medium.

  2. Isolation and growth characteristics of an EDTA-degrading member of the alpha-subclass of Proteobacteria.

    Science.gov (United States)

    Weilenmann, Hans-Ueli; Engeli, Barbara; Bucheli-Witschel, Margarete; Egli, Thomas

    2004-10-01

    A Gram-negative, ethylenediaminetetraacetic acid (EDTA)-degrading bacterium (deposited at the German Culture Collection as strain DSM 9103) utilising EDTA as the only source of carbon, energy and nitrogen was isolated from a mixed EDTA-degrading population that was originally enriched in a column system from a mixture of activated sludge and soil. Chemotaxonomic analysis of quinones, polar lipids and fatty acids allowed allocation of the isolate to the alpha-subclass of Proteobacteria. 16S rDNA sequencing and phylogenetic analysis revealed highest similarity to the Mesorhizobium genus followed by the Aminobacter genus. However, the EDTA-degrading strain apparently forms a new branch within the Phyllobacteriaceae/Mesorhizobia family. Growth of the strain was rather slow not only on EDTA (micro(max) = 0.05 h(-1)) but also on other substrates. Classical substrate utilisation testing in batch culture suggested a quite restricted carbon source spectrum with only lactate, glutamate, and complexing agents chemically related to EDTA (nitrilotriacetate, iminodiacetate and ethylenediaminedisuccinate) supporting growth. However, when EDTA-limited continuous cultures of strain DSM 9103 were pulsed with fumarate, succinate, glucose or acetate, these substrates were assimilated immediately. Apparently, the strain can use a broader spectrum than indicated by traditional substrate testing techniques. The EDTA species CaEDTA and MgEDTA served as growth substrates of the strain because in the mineral medium employed EDTA was predicted to be mainly present in the form of these two complexes. The bacterium was not able to degrade Fe3+-complexed EDTA.

  3. Differential Performance by English Language Learners on an Inquiry-Based Science Assessment

    Science.gov (United States)

    Turkan, Sultan; Liu, Ou Lydia

    2012-10-01

    The performance of English language learners (ELLs) has been a concern given the rapidly changing demographics in US K-12 education. This study aimed to examine whether students' English language status has an impact on their inquiry science performance. Differential item functioning (DIF) analysis was conducted with regard to ELL status on an inquiry-based science assessment, using a multifaceted Rasch DIF model. A total of 1,396 seventh- and eighth-grade students took the science test, including 313 ELL students. The results showed that, overall, non-ELLs significantly outperformed ELLs. Of the four items that showed DIF, three favored non-ELLs while one favored ELLs. The item that favored ELLs provided a graphic representation of a science concept within a family context. There is some evidence that constructed-response items may help ELLs articulate scientific reasoning using their own words. Assessment developers and teachers should pay attention to the possible interaction between linguistic challenges and science content when designing assessment for and providing instruction to ELLs.

  4. Assessment report of research and development activities. Activity: 'Nuclear science and engineering research' (Interim report)

    International Nuclear Information System (INIS)

    2013-11-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consults an assessment committee, 'Evaluation Committee of Research Activities for Nuclear Science and Engineering' (hereinafter referred to as 'Committee') for interim assessment of 'Nuclear Science and Engineering,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by the JAEA. In response to the JAEA's request, the Committee assessed the research program of the Nuclear Science and Engineering Directorate (hereinafter referred to as 'NSED') and Center for Computational Science and e-Systems (hereinafter referred to as 'CCSE') during the period of about four years from September 2008 to September 2012. The Committee evaluated the management and research activities of the NSED and the CCSE based on explanatory documents prepared by the NSED and the CCSE, and oral presentations with questions-and-answers by unit managers etc. A CD-ROM is attached as an appendix. (J.P.N.)

  5. Advice and Frequently Asked Questions (FAQs) for Citizen-Science Environmental Health Assessments.

    Science.gov (United States)

    Barzyk, Timothy M; Huang, Hongtai; Williams, Ronald; Kaufman, Amanda; Essoka, Jonathan

    2018-05-11

    Citizen science provides quantitative results to support environmental health assessments (EHAs), but standardized approaches do not currently exist to translate findings into actionable solutions. The emergence of low-cost portable sensor technologies and proliferation of publicly available datasets provides unparalleled access to supporting evidence; yet data collection, analysis, interpretation, visualization, and communication are subjective approaches that must be tailored to a decision-making audience capable of improving environmental health. A decade of collaborative efforts and two citizen science projects contributed to three lessons learned and a set of frequently asked questions (FAQs) that address the complexities of environmental health and interpersonal relations often encountered in citizen science EHAs. Each project followed a structured step-by-step process in order to compare and contrast methods and approaches. These lessons and FAQs provide advice to translate citizen science research into actionable solutions in the context of a diverse range of environmental health issues and local stakeholders.

  6. Bulgarian Contribution to World Science and Main Criteria for Assessing the Achievements of Scientists [In Bulgarian

    Directory of Open Access Journals (Sweden)

    B.V. Toshev

    2011-12-01

    Full Text Available The status and the new developments in world science are both discussed. The transition from the ‘normal science’ (Kuhn to the ‘post-normal science’ (Funtowicz & Ravetz is commented. The integration processes in science, the mass higher education and its mcdonaldization are also considered. The difference between ‘science’ and ‘surrogate science’ is explained. The existence of marginal journals as an attribute of the surrogate science is discussed. Such a broad-based consideration allows a realistic assess of the contribution of Bulgarian scientists in the development of world science to be made. Some of the most important scientific achievements made by Bulgarians are listed.

  7. Assessing middle school students` understanding of science relationships and processes: Year 2 - instrument validation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schau, C.; Mattern, N.; Weber, R.; Minnick, K.

    1997-01-01

    Our overall purpose for this multi-year project was to develop an alternative assessment format measuring rural middle school students understanding of science concepts and processes and the interrelationships among them. This kind of understanding is called structural knowledge. We had 3 major interrelated goals: (1) Synthesize the existing literature and critically evaluate the actual and potential use of measures of structural knowledge in science education. (2) Develop a structural knowledge alternative assessment format. (3) Examine the validity of our structural knowledge format. We accomplished the first two goals during year 1. The structural knowledge assessment we identified and developed further was a select-and-fill-in concept map format. The goal for our year 2 work was to begin to validate this assessment approach. This final report summarizes our year 2 work.

  8. Comparative study of conventional PAH and inulin clearance and slope clearance of 131I-o-hippuric acid and 51Cr-EDTA

    International Nuclear Information System (INIS)

    Berghaeuser, H.

    1981-01-01

    ''Classic'' PAH and inulin clearance were determined in 81 patients with renal anomalies or renal diseases of different genesis and severity. In addition, radioisotope nephrography was carried out after administration of I-131-o-hippuric acid, followed by administration of Cr-51-EDTA. The activity decrease was recorded by a sensor located over the patient's right shoulder; the activities of a serum sample and of the urine excreted after 21 or 31 min were measured, and the findings were compared with those of the classic method. The clearance data calculated on the basis of the soulder measurements were hardly compatible with those of the conventional method in the case of 131 I-o-hippuric acid (r=0.54) and totally incompatible in the case of 51 Cr-EDTA. This means that the method described by Oberhausen is the only accurate method available for a quantitative assessment of the renal function on the basis of measurements of the activity decrease in the body. The activity of urine excreted after 31 min ( 131 I-hippuric acid:r=0.992, 51 Cr-EDTA:r=0.79) is a sufficiently accurate parameter although it is inaccurate at PAH clearance, values > 130 ml/min and inulin clearance values > 30 ml/min. Of the many parameters of radioisotope nephrogram curves, in the case of 131 I-o-hippuric acid only the parameters related to the ascent between 48 and 120 sec or to the secant ascent yield sufficient quantitative information for certain functional regions (r=0.9 resp. r=0.93). In the case of 51 Cr-EDTA, semiquantitative information on the renal function can be obtained by constructing secants on the nephrogram curves (r=0.7 resp. r=0.72). Here as in the case of 131 I-hippuric acid, the contribution of each kidney can be determined individually from the functional analysis of both kidneys. (orig.) [de

  9. Chlorhexidine controlled-release profile after EDTA root surface etching: an in vivo study.

    Science.gov (United States)

    Gamal, Ahmed Y; Kumper, Radi M; Sadek, Hesham S; El Destawy, Mahmoud T

    2011-05-01

    The main objective of the present study was to quantify chlorhexidine (CHX) release after the use of CHX-EDTA root surface treatment as a local-delivery antimicrobial vehicle. Twenty non-smoking patients clinically diagnosed as having moderate-to-severe chronic periodontitis were selected to participate in this study. After cause-related therapy, one site in every patient received defect overfill with CHX gel 2% (20 sites). In addition, twenty contralateral sites received defect fill of CHX gel after 3 minutes of 24% EDTA gel root surface etching (20 sites). Gingival crevicular fluid samples were collected at 1, 3, 7, and 14 days post-therapy. The CHX-EDTA group showed statistically significantly higher levels of CHX than those of the control group at 1, 3, and 7 days. At 14 days, the CHX-EDTA group showed 0.8 mg/mL values. The use of CHX-EDTA root surface treatment as a local-delivery antimicrobial improves CHX substantivity.

  10. Column leaching of chromium and nickel from a contaminated soil using EDTA and citric acid

    International Nuclear Information System (INIS)

    Jean-Soro, Liliane; Bordas, François; Bollinger, Jean-Claude

    2012-01-01

    This study investigates the column leaching of a soil contaminated mainly with Cr and Ni by using two chelants: citric acid (biodegradable) and EDTA (non-biodegradable) followed with water rinse. The chelants lead to Cr and Ni leaching, in addition to major elements (Ca, Fe, Mg, Al, Mn and Zn) showing the dissolution of soil mineral constituents. EDTA leaches more major elements and Ni than citric acid related to the respective stability of metal–chelant complexes; citric acid leaches more Cr than EDTA, certainly because of a substitution reaction with Cr(VI). In the case of alternating chelant/water applications, leaching occurs during the chelant applications, but also during water applications. In the case of chelant/water applications followed by continuous water application, both Cr and Ni leach over time. This increased mobility could be due to the residual chelant present in soil as well as to the dissolution/mobilization of mineral or organic soil fractions. - Highlights: ► Column leaching of an industrial soil contaminated with chromium and nickel. ► Citric acid or EDTA were used alternatively or followed with water rinse. ► Chelants lead to Cr and Ni leaching and the dissolution of soil mineral constituents. ► Leaching of these two metals proceeds continuously during water rinse. ► Chelants deeply impacted Cr and Ni mobility. - Citric acid or EDTA application deeply impact Cr and Ni mobility during column leaching of a contaminated soil.

  11. Efficacy of the chelating agent CaEDTA in reversing lead-induced changes in behavior.

    Science.gov (United States)

    Cory-Slechta, D A; Weiss, B

    1989-01-01

    The chelating agent CaEDTA has been reported to reverse the deficits in intellectual function and performance associated with Pb (lead) exposure in children. However, such studies have not included rigorous controls for the intervention procedures per se. The experiments reported here examined reversibility of performance changes in a rat model based on behavior sensitive to low-level Pb exposure. Rats were exposed to 50 ppm sodium or Pb acetate in drinking water from weaning. Performance maintained under a Fixed-Interval schedule of food reinforcement began at 55 days of age. Following the onset of the characteristic increase in short interresponse times (IRTs) associated with low-level Pb exposure after 35 experimental sessions, Pb treatment was terminated. Animals within both the control and Pb groups were then matched on the basis of performance indices and injected daily for 5 days with either saline, 75 mg/kg or 150 mg/kg CaEDTA. Subsequent changes in F1 performance were monitored for 35-60 sessions. No consistent effects of CaEDTA were detected in control animals. CaEDTA treatment failed to reverse the behavioral effects in Pb-exposed animals. If anything, it tended to further increase the proportion of short IRTs. These data suggest that better controlled clinical studies are warranted to evaluate the efficacy of CaEDTA in reversing Pb-induced behavioral effects before its application for these purposes becomes widespread.

  12. A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

    OpenAIRE

    Sampaio, José Eduardo Cezar; Campos, Flávia Pavan; Pilatti, Gibson Luiz; Theodoro, Letícia Helena; Leite, Fábio Renato Manzolli

    2005-01-01

    The aim of the present study was to compare root surface smear layer removal following topical application of EDTA and EDTA-T (Texapon). Extracted human teeth had their cementum removed and were mechanically scaled. A total of 220 root specimens were obtained and were randomly assigned to the following groups: I-saline solution(control), II-EDTA; III-EDTAT. Groups II and III specimens were assigned to different EDTA gel concentrations: 5%, 10%, 15%, 20% and 24%. Smear layer removal score was ...

  13. Effects of EDTA and low molecular weight organic acids on soil solution properties of a heavy metal polluted soil.

    Science.gov (United States)

    Wu, L H; Luo, Y M; Christie, P; Wong, M H

    2003-02-01

    A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the soil solution in the rhizosphere of Brassica juncea grown in a paddy soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the soil solution pH. EDTA addition significantly increased the TOC concentrations in the soil solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the soil solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the soil solution followed the sequence: EDTA > citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA > MA > CA approximately OA for Zn; and EDTA > MA > CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.

  14. Synthesis of LaNiO3 perovskite type by chelating precursor method using EDTA: optimization of chelating content

    International Nuclear Information System (INIS)

    Santos, Jose Carlos dos; Pedrosa, Anne Michelle Garrido; Mesquita, Maria Eliane; Souza, Marcelo Jose Barros de

    2011-01-01

    The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO 3 perovskite type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis. The synthesized materials were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TG) and Infrared Spectroscopy (FTIR). In the optimization of the EDTA content the lowest ratio of metal / EDTA used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite. (author)

  15. Enhanced science-stakeholder communication to improve ecosystem model performances for climate change impact assessments.

    Science.gov (United States)

    Jönsson, Anna Maria; Anderbrant, Olle; Holmér, Jennie; Johansson, Jacob; Schurgers, Guy; Svensson, Glenn P; Smith, Henrik G

    2015-04-01

    In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science-stakeholder collaboration, and in a two-way dialog link empirical experience and impact modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science-stakeholder communication. By this, we hope to stimulate a discussion among the science-stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models.

  16. Chemistry teachers’ understanding of science process skills in relation of science process skills assessment in chemistry learning

    Science.gov (United States)

    Hikmah, N.; Yamtinah, S.; Ashadi; Indriyanti, N. Y.

    2018-05-01

    A Science process skill (SPS) is a fundamental scientific method to achieve good knowledge. SPS can be categorized into two levels: basic and integrated. Learning SPS helps children to grow as individuals who can access knowledge and know how to acquire it. The primary outcomes of the scientific process in learning are the application of scientific processes, scientific reasoning, accurate knowledge, problem-solving, and understanding of the relationship between science, technology, society, and everyday life’s events. Teachers’ understanding of SPS is central to the application of SPS in a learning process. Following this point, this study aims to investigate the high school chemistry teachers’ understanding of SPS pertains to their assessment of SPS in chemistry learning. The understanding of SPS is measured from the conceptual and operational aspects of SPS. This research uses qualitative analysis method, and the sample consists of eight chemistry teachers selected by random sampling. A semi-structured interview procedure is used to collect the data. The result of the analysis shows that teachers’ conceptual and operational understanding of SPS is weak. It affects the accuracy and appropriateness of the teacher’s selection of SPS assessment in chemistry learning.

  17. Assessment of Service Desk Quality at an Academic Health Sciences Library.

    Science.gov (United States)

    Blevins, Amy E; DeBerg, Jennifer; Kiscaden, Elizabeth

    2016-01-01

    Due to an identified need for formal assessment, a small team of librarians designed and administered a survey to gauge the quality of customer service at their academic health sciences library. Though results did not drive major changes to services, several important improvements were implemented and a process was established to serve as a foundation for future use. This article details the assessment process used and lessons learned during the project.

  18. Business Statistics and Management Science Online: Teaching Strategies and Assessment of Student Learning

    Science.gov (United States)

    Sebastianelli, Rose; Tamimi, Nabil

    2011-01-01

    Given the expected rise in the number of online business degrees, issues regarding quality and assessment in online courses will become increasingly important. The authors focus on the suitability of online delivery for quantitative business courses, specifically business statistics and management science. They use multiple approaches to assess…

  19. Endorsing the Practical Endorsement? OCR's Approach to Practical Assessment in Science A-Levels

    Science.gov (United States)

    Evans, Steve; Wade, Neil

    2015-01-01

    This article summarises the practical requirements for new science A-levels in biology, chemistry and physics for first teaching from September 2015. It discusses the background to how the new approach was reached and how OCR has seen this taking shape in our assessment models. The opportunities presented by this new approach to practical…

  20. Integrated Science Assessment (ISA) for Carbon Monoxide (Second External Review Draft, Sep 2009)

    Science.gov (United States)

    EPA announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of t...

  1. Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (First External Review Draft, Sep 2007)

    Science.gov (United States)

    EPA has announced that the First External Review Draft of the Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria has been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluatio...

  2. From Log Files to Assessment Metrics: Measuring Students' Science Inquiry Skills Using Educational Data Mining

    Science.gov (United States)

    Gobert, Janice D.; Sao Pedro, Michael; Raziuddin, Juelaila; Baker, Ryan S.

    2013-01-01

    We present a method for assessing science inquiry performance, specifically for the inquiry skill of designing and conducting experiments, using educational data mining on students' log data from online microworlds in the Inq-ITS system (Inquiry Intelligent Tutoring System; www.inq-its.org). In our approach, we use a 2-step process: First we use…

  3. Assessment report of research and development activities. Activity: 'Advanced science research' (Pre-review report)

    International Nuclear Information System (INIS)

    2010-11-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for prior assessment of 'Advanced Science Research,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program and activities of the Advanced Science Research Center (hereinafter referred to as 'ASRC') for the period of five years from April 2010. The Committee evaluated the management and the research program of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  4. Teaching and Assessing Ethics and Social Responsibility in Undergraduate Science: A Position Paper

    Science.gov (United States)

    Schultz, Madeleine

    2014-01-01

    Institutional graduate capabilities and discipline threshold learning outcomes require science students to demonstrate ethical conduct and social responsibility. However, the teaching and assessment of these concepts are not straightforward. Australian chemistry academics participated in a workshop in 2013 to discuss and develop teaching and…

  5. Assessment report on research and development activities. Activity: 'Advanced science research' (Interim report)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-15

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for interim assessment of 'Advanced Science Research,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research programs and activities of the Advanced Science Research Center (hereinafter referred to as 'ASRC') for the period of two years from April 2010. The Committee evaluated the management and the research programs of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  6. Assessment report on research and development activities. Activity: 'Advanced science research' (Interim report)

    International Nuclear Information System (INIS)

    2012-11-01

    Japan Atomic Energy Agency (hereinafter referred to as “JAEA”) consulted an assessment committee, “Evaluation Committee of Research Activities for Advanced Science Research” (hereinafter referred to as “Committee”) for interim assessment of “Advanced Science Research,” in accordance with “General Guideline for the Evaluation of Government Research and Development (R and D) Activities” by Cabinet Office, Government of Japan, “Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology” and “Regulation on Conduct for Evaluation of R and D Activities” by JAEA. In response to the JAEA's request, the Committee assessed the research programs and activities of the Advanced Science Research Center (hereinafter referred to as “ASRC”) for the period of two years from April 2010. The Committee evaluated the management and the research programs of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  7. Assessing and Analyzing Behavior Strategies of Instructors in College Science Laboratories.

    Science.gov (United States)

    Kyle, William C., Jr.; And Others

    1980-01-01

    Analyzed are university instructor behaviors in introductory and advanced level laboratories of botany, chemistry, geology, physics and zoology. Science Laboratory Interaction Categories--Teacher (SLIC) was used to assess 15 individual categories of teacher behaviors in the areas of questioning, giving directions, transmitting information,…

  8. Science teachers' mission impossible?: a qualitative study of obstacles in assessing students' practical abilities

    Science.gov (United States)

    Sund, Per

    2016-09-01

    Science teachers regard practical work as important and many claim that it helps students to learn science. Besides theoretical knowledge, such as concepts and formulas, practical work is considered to be an integral and basic part of science education. As practical work is perceived and understood in different ways, comparing the results between classes and schools is difficult. One way of making the results comparable is to develop systematic inquiries to be assessed in national large-scale tests. However, introducing similar testing conditions in a laboratory environment is not always possible. Although the instructions and assessment guides for such tests are detailed, many obstacles need to be overcome if equality in the overall test situation is to be achieved. This empirical case study investigates two secondary school science teachers' assessments of 15-16 years old students in three separate groups in the practical part of a Swedish national test in chemistry. Data are gathered using two video cameras and three pairs of spy camera glasses. The results show that individual and independent assessments are difficult due to the social interactions that take place and the physical sources of errors that occur in this type of setting.

  9. Science and Biology Assessment in Hong Kong--Progress and Developments

    Science.gov (United States)

    Cheng, May Hung; Cheung, Wing Ming Francis

    2005-01-01

    A paper was published in JBE in 2001 which examined the background of the education reform launched in 2000 in Hong Kong, and reviewed existing practices as well as beliefs in science and biology assessment among secondary teachers in Hong Kong. The direction of the reform was to take the emphasis away from public examinations as the sole…

  10. Using Citation Analysis Methods to Assess the Influence of Science, Technology, Engineering, and Mathematics Education Evaluations

    Science.gov (United States)

    Greenseid, Lija O.; Lawrenz, Frances

    2011-01-01

    This study explores the use of citation analysis methods to assess the influence of program evaluations conducted within the area of science, technology, engineering, and mathematics (STEM) education. Citation analysis is widely used within scientific research communities to measure the relative influence of scientific research enterprises and/or…

  11. INFORMATION SCIENCE--OUTLINE, ASSESSMENT, INTERDISCIPLINARY DISCUSSION. REPORT FOR JUNE, 1965-JUNE, 1966.

    Science.gov (United States)

    IBERALL, A.S.

    THIS REPORT PROVIDES AN ASSESSMENT AND INTRODUCTION TO THE INTERDISCIPLINARY LITERATURE OF THREE APSECTS OF INFORMATION SCIENCE, IN ANNOTATED BIBLIOGRAPHY FORM. THESE ARE--COMMUNICATION NETWORKS, HUMAN INFORMATION PROCESSES (PRINCIPALLY LANGUAGE AND INFORMATION RETRIEVAL), AND THE LARGE CYBERNETIC SYSTEMS SUCH AS THE HUMAN BRAIN AND CENTRAL…

  12. English Language Assessment in the Colleges of Applied Sciences in Oman: Thematic Document Analysis

    Science.gov (United States)

    Al Hajri, Fatma

    2014-01-01

    Proficiency in English language and how it is measured have become central issues in higher education research as the English language is increasingly used as a medium of instruction and a criterion for admission to education. This study evaluated the English language assessment in the foundation Programme at the Colleges of Applied sciences in…

  13. Short Circuits or Superconductors? Effects of Group Composition on High-Achieving Students' Science Assessment Performance.

    Science.gov (United States)

    Webb, Noreen M.; Nemer, Kariane Mari; Zuniga, Stephen

    2002-01-01

    Studied the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high-ability students completing science assessments. Results for 83 high ability students show the quality of group functioning serves as the strongest predictor of high-ability students' performance and explained much of the…

  14. Assessment and Teaching of Science Skills: Whole of Programme Perceptions of Graduating Students

    Science.gov (United States)

    Hodgson, Yvonne; Varsavsky, Cristina; Matthews, Kelly E.

    2014-01-01

    This study reports on science student perceptions of their skills (scientific knowledge, oral communication, scientific writing, quantitative skills, teamwork and ethical thinking) as they approach graduation. The focus is on which teaching activities and assessment tasks over the whole programme of study students thought utilised each of the six…

  15. Assessing Earth and Environmental Science Enrollment Trends in Texas Public High Schools

    Science.gov (United States)

    Sanders, Joan G.

    2012-01-01

    Scope and Method of Study: This study assesses the status of Earth and environmental sciences education in Texas Public High Schools by analyzing enrollment proportions of 11th and 12th grade students in 607 Independent School Districts (ISD) for the 2010-2011 academic school year using a quantitative, non-experimental alpha research design. This…

  16. 75 FR 69078 - Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA)

    Science.gov (United States)

    2010-11-10

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9224-7] Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Workshop... (NAAQS) for Lead (Pb), EPA is announcing that a workshop to evaluate initial draft materials for the Pb...

  17. Sustainability Logistics Basing - Science and Technology Objective - Demonstration; Industry Assessment and Demonstration Final Report

    Science.gov (United States)

    2017-08-14

    TECHNICAL REPORT AD ________________ NATICK/TR-17/019 SUSTAINABILITY ...LOGISTICS BASING – SCIENCE & TECHNOLOGY OBJECTIVE – DEMONSTRATION; INDUSTRY ASSESSMENT AND DEMONSTRATION FINAL REPORT by Elizabeth D. Swisher and...Benjamin J. Campbell August 2017 Final Report December 2014 – February 2016 Approved for public release; distribution is

  18. Preliminary Analysis of Assessment Instrument Design to Reveal Science Generic Skill and Chemistry Literacy

    Science.gov (United States)

    Sumarni, Woro; Sudarmin; Supartono, Wiyanto

    2016-01-01

    The purpose of this research is to design assessment instrument to evaluate science generic skill (SGS) achievement and chemistry literacy in ethnoscience-integrated chemistry learning. The steps of tool designing refers to Plomp models including 1) Investigation Phase (Prelimenary Investigation); 2) Designing Phase (Design); 3)…

  19. Student Self-Assessment in HOCS Science Examinations: Is There a Problem?

    Science.gov (United States)

    Zoller, Uri; Ben-Chaim, David

    1998-06-01

    A specially-designed self-assessment questionnaire (SAQHOCS), containing higher-order cognitive skills (HOCS)-type questions, was administered to 71 biology majors, enrolled in a four-year college program. The gap between students' self-assessment marking, and that of their HOCS-biased teachers (the authors), is accounted for by the prevailing LOCS-orientation and the "testing culture"—a total separation between testing and learning—in contemporary science teaching. The majority of the students in the study evaluated themselves as capable of self-assessment, and felt reasonably confident in doing so. They were quite reserved as far as the applicability of the self-assessment method to nonalgorithmic ("correct/incorrect") questions is concerned. The results of this study suggest that the potential for student self-assessment within college science teaching and learning exists. However, still a great purposed effort in HOCS-oriented teaching and learning is required in order for the student self-assessment practice to become a routine integral component of HOCS science examinations.

  20. Confidence in Science and Achievement Outcomes of Fourth-Grade Students in Korea: Results from the TIMSS 2011 Assessment

    Science.gov (United States)

    House, J. Daniel; Telese, James A.

    2017-01-01

    Findings from assessments of fourth-grade science have indicated that students in Korea scored higher than international averages. Research results have also shown that attitudes toward science were related to achievement outcomes for Korean students. The purpose of this study was to examine the relationship between confidence in science and…

  1. Assessing the impact participation in science journalism activities has on scientific literacy among high school students

    Science.gov (United States)

    Farrar, Cathy

    As part of the National Science Foundation Science Literacy through Science Journalism (SciJourn) research and development initiative (http://www.scijourn.org ; Polman, Saul, Newman, and Farrar, 2008) a quasi-experimental design was used to investigate what impact incorporating science journalism activities had on students' scientific literacy. Over the course of a school year students participated in a variety of activities culminating in the production of science news articles for Scijourner, a regional print and online high school science news magazine. Participating teachers and SciJourn team members collaboratively developed activities focused on five aspects of scientific literacy: placing information into context, recognizing relevance, evaluating factual accuracy, use of multiple credible sources and information seeking processes. This study details the development process for the Scientific Literacy Assessment (SLA) including validity and reliability studies, evaluates student scientific literacy using the SLA, examines student SLA responses to provide a description of high school students' scientific literacy, and outlines implications of the findings in relation to the National Research Council's A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (2012) and classroom science teaching practices. Scientifically literate adults acting as experts in the assessment development phase informed the creation of a scoring guide that was used to analyze student responses. Experts tended to draw on both their understanding of science concepts and life experiences to formulate answers; paying close attention to scientific factual inaccuracies, sources of information, how new information fit into their view of science and society as well as targeted strategies for information seeking. Novices (i.e., students), in contrast, tended to ignore factual inaccuracies, showed little understanding about source credibility and suggested

  2. Teaching Scientists to Communicate: Evidence-based assessment for undergraduate science education

    Science.gov (United States)

    Mercer-Mapstone, Lucy; Kuchel, Louise

    2015-07-01

    Communication skills are one of five nationally recognised learning outcomes for an Australian Bachelor of Science (BSc) degree. Previous evidence indicates that communication skills taught in Australian undergraduate science degrees are not developed sufficiently to meet the requirements of the modern-day workplace-a problem faced in the UK and USA also. Curriculum development in this area, however, hinges on first evaluating how communication skills are taught currently as a base from which to make effective changes. This study aimed to quantify the current standard of communication education within BSc degrees at Australian research-intensive universities. A detailed evidential baseline for not only what but also how communication skills are being taught was established. We quantified which communication skills were taught and assessed explicitly, implicitly, or were absent in a range of undergraduate science assessment tasks (n = 35) from four research-intensive Australian universities. Results indicate that 10 of the 12 core science communication skills used for evaluation were absent from more than 50% of assessment tasks and 77.14% of all assessment tasks taught less than 5 core communication skills explicitly. The design of assessment tasks significantly affected whether communication skills were taught explicitly. Prominent trends were that communication skills in tasks aimed at non-scientific audiences were taught more explicitly than in tasks aimed at scientific audiences, and the majority of group and multimedia tasks taught communication elements more explicitly than individual, or written and oral tasks. Implications for science communication in the BSc and further research are discussed.

  3. Comparison between total and renal plasma clearance of [51Cr]EDTA

    International Nuclear Information System (INIS)

    Broechner-Mortensen, J.; Roedbro, P.

    1976-01-01

    The total plasma (E 1 ) and renal plasma (E 2 ) clearances of [ 51 Cr]EDTA were measured simultaneously in 40 patients with a wide range of renal function. The regression equation was E 1 = 0.997E 2 + 4.1; the slope of the regression line was not significantly different from 1.00, and the intercept differed significantly from zero. The results suggest that [ 51 Cr]EDTA has a significant extrarenal clearance of approximately 4 ml/min, independent of renal function. The data are used to correct the total [ 51 Cr]EDTA plasma clearance, measured by a simplified method, to yield a rapid, accurate and precise measurement of glomerular filtration rate for routine clinical use. (Auth.)

  4. EDTA-assisted synthesis of rose-like ZnO architectures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China); Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Fang, Yaoguo [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China); Peng, Liwei; Wu, Minghong [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Pan, Dengyu

    2010-10-15

    Rose-like ZnO nanostructures were prepared by a low-temperature solution route with assistance of ethylenediaminetetraacetic acid disodium (EDTA-2Na). The morphology of ZnO nanostructures was found to change from nanowire arrays to rose- and tower-like architectures with increasing the molar ratio of EDTA-2Na/Zn{sup 2+}. Also, the shape evolution of ZnO nanostructures with time was observed from flat nanosheets to wrinkled nanosheets and to rose-like nanostructures. EDTA-2Na as a strong complexing agent was found to play a key role in the shape evolution. Photoluminescence spectra show that the rose-like ZnO architectures have more defects than the nanowire arrays. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Interactions between 59Fe(14C)EDTA and soils containing calcium carbonate

    International Nuclear Information System (INIS)

    Hargitai-Toth, A.; Konya, J.

    1991-01-01

    Interaction between FeEDTA and calcareous soils was followed over a period of four weeks using a radiotracer technique, and a kinetic evaluation of the results was performed. 59 Fe served to determine the quantity of iron, 14 C to assay for EDTA and 45 Ca to measure calcium. During the experiment, i.e. within four weeks in case of the chernozem soil 61% and in case of the clayey meadow soil 51% of the iron chelate disappeared from the solution. The loss in soluble iron was partly due to a rapid sorption process of about an hour and partly due to the slow decomposition of FeEDTA to Fe(OH) 3 . The two processes could be separated using the Christiansen equation. (author) 9 refs.; 1 figs.; 2 tabs

  6. [51Cr]EDTA intestinal permeability in children with cow's milk intolerance

    International Nuclear Information System (INIS)

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J.

    1990-01-01

    Making use of [ 51 Cr]EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. [ 51 Cr]EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the [ 51 Cr]EDTA test can be helpful for the diagnosis of cow's milk intolerance

  7. Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

    Science.gov (United States)

    Hajeb, P; Jinap, S

    2012-06-13

    An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish.

  8. (51Cr)EDTA intestinal permeability in children with cow's milk intolerance

    Energy Technology Data Exchange (ETDEWEB)

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J. (Academic Hospital Maastricht (Netherlands))

    1990-02-01

    Making use of ({sup 51}Cr)EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. ({sup 51}Cr)EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the ({sup 51}Cr)EDTA test can be helpful for the diagnosis of cow's milk intolerance.

  9. Temporal Lob Epilepsi'sinde L-Arginine ve CaEDTA'nın Etkileri

    OpenAIRE

    NOYAN, Behzat

    2005-01-01

    Bu çalışmada, bir nitrik oksit (NO-) prekürsörü olan L-Arginine ve bir ekstrasellüler çinko şelatörü olan CaEDTA'nın pilokarpine HCl ile oluşturulan kısa süreli epileptik nöbet üzerine etkileri araştırıldı. Deney, nöbet kontrol (serum fizyolojik 10 µl, i.c.v., ve sonra 380 mg/kg pilokarpine HCl i.p.), L-Arginine (150 µg/10 µl, i.c.v.), CaEDTA (100 mM, 10 µl, i.c.v.), L-Arginine+CaEDTA olmak üzere 4 gruptan oluştu. Enjeksiyonlardan sonra iki saat boyunca nöbet davranışları gözlemlenen ...

  10. Application of expert-notice dialogue (END) method to assess students’ science communication ability on biology

    Science.gov (United States)

    Sriyati, S.; Amelia, D. N.; Soniyana, G. T.

    2018-05-01

    Student’s science communication ability can be assessed by the Expert-Notice Dialogue (END) method which focusing on verbal explanations using graphs or images as a tool. This study aims to apply the END method to assess students’ science communication ability. The study was conducted in two high schools with each sample of one class at each school (A and B). The number of experts in class A is 8 students and 7 in class B, the number of notice in class A 24 students and 30 in class B. The material chosen for explanation by expert is Ecosystem in class A and plant classification in class B. Research instruments are rubric of science communication ability, observation rubric, notice concept test and notice questionnaire. The implementation recorded with a video camera and then transcribed based on rubric science communication ability. The results showed that the average of science communication ability in class A and B was 60% and 61.8%, respectively, in enough categories. Mastery of the notice concept is in good category with 79.10 averages in class A and 94.64 in class B. Through the questionnaire notice it is known that the END method generally helps notice in understanding the concept.

  11. Perceptions and attitudes of formative assessments in middle-school science classes

    Science.gov (United States)

    Chauncey, Penny Denyse

    No Child Left Behind mandates utilizing summative assessment to measure schools' effectiveness. The problem is that summative assessment measures students' knowledge without depth of understanding. The goal of public education, however, is to prepare students to think critically at higher levels. The purpose of this study was to examine any difference between formative assessment incorporated in instruction as opposed to the usual, more summative methods in terms of attitudes and academic achievement of middle-school science students. Maslow's theory emphasizes that individuals must have basic needs met before they can advance to higher levels. Formative assessment enables students to master one level at a time. The research questions focused on whether statistically significant differences existed between classrooms using these two types of assessments on academic tests and an attitude survey. Using a quantitative quasi-experimental control-group design, data were obtained from a sample of 430 middle-school science students in 6 classes. One control and 2 experimental classes were assigned to each teacher. Results of the independent t tests revealed academic achievement was significantly greater for groups that utilized formative assessment. No significant difference in attitudes was noted. Recommendations include incorporating formative assessment results with the summative results. Findings from this study could contribute to positive social change by prompting educational stakeholders to examine local and state policies on curriculum as well as funding based on summative scores alone. Use of formative assessment can lead to improved academic success.

  12. A laboratory and field evaluation of the mobility of cobalt-60/EDTA

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Kirkham, R.R.; Swanson, J.L.

    1983-01-01

    We have observed a time and soil type dependence in the ability of the organic complexant EDTA to keep cobalt-60 in solution. Test results indicate that short-term adsorption tests lasting 5 days or less can be misleading. In short-term tests using cobalt-60/EDTA and soil from the Hanford site, low sorption in batch tests and high mobility in column tests were observed. During long-term batch test using cobalt-60/EDTA, the percentage of cobalt remaining in solution decreased from 90% after 7 days to less than 10% after 500 days. In laboratory and field column tests where low water flow rates allowed long contact time, virtually no cobalt movement was observed even though in the field test tritium was transported over 4 meters. Long-term batch tests using cobalt-60/EDTA and soil from Savannah River burial grounds showed that cobalt remainin in solution dropped to 30% of the total cobalt added after 5 days and to less than 1% after 15 days. Batch tests using soil from Oak Ridge burial grounds were less dramatic showing cobalt in solution decreasing from 90% after 5 days to 70% after 35 days. The cobalt-60/EDTA complex appears to be dissociating and leaving uncomplexed cobalt which is readily sorbed. The dissociation seems to be rather complete in Hanford and Savannah River soil but limited in the Oak Ridge soil. The implication to waste management is that the potential for transport of cobalt by EDTA may not be as serious at all burial sites as once thought

  13. Influence of EDTA2− on the hydrothermal synthesis of CdTe nanocrystallites

    International Nuclear Information System (INIS)

    Gong Haibo; Hao Xiaopeng; Wu Yongzhong; Cao Bingqiang; Xu Hongyan; Xu Xiangang

    2011-01-01

    Transformation from Te nanorods to CdTe nanoparticles was achieved with the assistance of EDTA as a ligand under hydrothermal conditions. Experimental results showed that at the beginning of reaction Te nucleated and grew into nanorods. With the proceeding of reaction, CdTe nucleus began to emerge on the surface, especially on the tips of Te nanorods. Finally, nearly monodispersed hexagonal CdTe nanoparticles with diameters of about 200 nm were obtained. The effects of EDTA on the morphology and formation of CdTe nanoparticles were discussed in consideration of the strong ligand-effect of EDTA, which greatly decreased the concentration of Cd 2+ . Furthermore, the possible formation process of CdTe nanoparticles from Te nanorods was further proposed. The crystal structure and morphology of the products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). - Graphical Abstract: Firstly, Te nucleated and grew into nanorods in the presence of EDTA 2− . Then CdTe nucleus began to emerge on Te nanorods and finally monodispersed CdTe nanoparticles were obtained. Highlights: ► EDTA serves as a strong ligand with Cd 2+ . ► The existence of EDTA constrains the nucleation of CdTe and promotes the formation of Te nanorods. ► With the proceeding of reaction, CdTe nucleus began to emerge on the surface, especially on the tips of Te nanorods. ► Nearly monodispersed hexagonal CdTe nanoparticles with diameters of about 200 nm were finally obtained.

  14. Treatment of EDTA contained reactor coolant using water dielectric barrier discharge plasma

    International Nuclear Information System (INIS)

    Song, Sang Heon; Kwon, Daniel; Kim, Gon Ho

    2005-01-01

    EDTA (Ethylene Diamine Tetraacetic Acid) is used as a main absorbent for the metal ion in the secondary loop of the nuclear reactor. Dissolving the wasted EDTA with low cost, therefore, is important issue for the maintenance of the nuclear power reactor and the protection of environment. EDTA is not easily biodegradable, furthermore these methods could make remained another pollutant as complex chemical compounds. Compared to chemical method, the physical methods, using the energetic particles and UVs, are more favorable because they dissociate the bonds of organic compounds directly without the secondary chemical reactions during the treatment. Recently, high energy electron beam, the plasma torch, and the water breakdown by high voltage pulse are applied to treatment of the waste water contained chemicals. Here consideration is narrow down to improve the interaction between the plasma and the chemical bonds of EDTA because the energetic particles; activated radicals, and UVs, are abundant in plasmas. The new method adapted of the water DBD (dielectric barrier discharge) which plasma generates directly on the top of the water contained EDTA is proposed. The application of DBD plasmas has been extended for cleaning the organic compounds from the contaminated surface and also for removing volatile organic chemicals (VOC) such as NO x and SO x from the exhausted gases. Here, the water DBD reactor (SEMTECH, SD-DWG-04-1) is consisted that the one electrode is a ceramic insulator and another one is the water itself. Interestingly, the one electrode, the water, is not the solid dielectric electrode. In this study, therefore, the characteristics with driving frequency are considered and the feasibility of this new method for the DBD treatment of EDTA contained water is demonstrated

  15. Technology Readiness Level Assessment Process as Applied to NASA Earth Science Missions

    Science.gov (United States)

    Leete, Stephen J.; Romero, Raul A.; Dempsey, James A.; Carey, John P.; Cline, Helmut P.; Lively, Carey F.

    2015-01-01

    Technology assessments of fourteen science instruments were conducted within NASA using the NASA Technology Readiness Level (TRL) Metric. The instruments were part of three NASA Earth Science Decadal Survey missions in pre-formulation. The Earth Systematic Missions Program (ESMP) Systems Engineering Working Group (SEWG), composed of members of three NASA Centers, provided a newly modified electronic workbook to be completed, with instructions. Each instrument development team performed an internal assessment of its technology status, prepared an overview of its instrument, and completed the workbook with the results of its assessment. A team from the ESMP SEWG met with each instrument team and provided feedback. The instrument teams then reported through the Program Scientist for their respective missions to NASA's Earth Science Division (ESD) on technology readiness, taking the SEWG input into account. The instruments were found to have a range of TRL from 4 to 7. Lessons Learned are presented; however, due to the competition-sensitive nature of the assessments, the results for specific missions are not presented. The assessments were generally successful, and produced useful results for the agency. The SEWG team identified a number of potential improvements to the process. Particular focus was on ensuring traceability to guiding NASA documents, including the NASA Systems Engineering Handbook. The TRL Workbook has been substantially modified, and the revised workbook is described.

  16. Strategies for assessment of inquiry learning in science in a Danish context

    DEFF Research Database (Denmark)

    Petersen, Morten Rask; Albrechtsen, Thomas R. S.; Michelsen, Claus

    it would be more appropriate to use a more formative assessment (Black, 2002). In several European science curricula there is room for this latter approach but it seems that it is not carried out in practice. In a review of national curricula among partners of the SAILS (Strategies for Assessment...... in all countries, it is not reflected in the assessment used in most of the participating countries. We feel that this highlights a need for assessment instruments and tools that measure the inquiry skills of students. If these skills are not being assessed, it is difficult for teachers and students...... to realise the value of inquiry based methodologies.” (McLoughlin et al., 2013, p. 108) It is the aim of the SAILS project to develop materials for teachers to use in assessing student skills and competencies obtained by IBSE. It is done by finding exemplary lesson plans with inquiry approaches...

  17. An Assessment of Factors Relating to High School Students' Science Self-Efficacy

    Science.gov (United States)

    Gibson, Jakeisha Jamice

    This mixed-methods case study examined two out-of-school (OST) Science, Technology, Engineering and Math (STEM) programs at a science-oriented high school on students' Self-Efficacy. Because STEM is a key for future innovation and economic growth, Americans have been developing a variety of approaches to increase student interest in science within the school curriculum and in OST programs. Nationwide, many OST programs are offered for students but few have engaged in an in-depth assessment. This study included an assessment of two different types of OST programs and direct observations by the researcher. This study involved two advisors (one male, one female), 111 students, and their parents during 2016. Student participants completed two standardized surveys, one to determine their Science Self-Efficacy and another to assess their engagement in science during their OST programs. Parents described their parental involvement and their child's interest in the OST program(s). The OST program advisors participated in lengthy interviews. Additionally, the advisors rated their perceived interest level of the enrolled students and recorded attendance data. Bandura's Social Cognitive Theory (1997a) provided the theoretical framework. This theory describes the multidirectional influence of behavioral factors, personal factors, and environmental factors have on a student's Self-Efficacy. Compiled data from the teachers, students, and parents were used to determine the relationship of selected variables on Science Self-Efficacy of students. A correlational analysis revealed that students who participated in these OST programs possessed a high Mindset for the Enjoyment of science and that teacher ratings were also positively correlated to Mindset and Enjoyment of Science. Descriptive analyses showed that (a) girls who chose to participate in these OST programs possessed higher school grades in their in-school coursework than boys, (b) that parents of girls participated in more

  18. Gender differences in national assessment of educational progress science items: What does i don't know really mean?

    Science.gov (United States)

    Linn, Marcia C.; de Benedictis, Tina; Delucchi, Kevin; Harris, Abigail; Stage, Elizabeth

    The National Assessment of Educational Progress Science Assessment has consistently revealed small gender differences on science content items but not on science inquiry items. This assessment differs from others in that respondents can choose I don't know rather than guessing. This paper examines explanations for the gender differences including (a) differential prior instruction, (b) differential response to uncertainty and use of the I don't know response, (c) differential response to figurally presented items, and (d) different attitudes towards science. Of these possible explanations, the first two received support. Females are more likely to use the I don't know response, especially for items with physical science content or masculine themes such as football. To ameliorate this situation we need more effective science instruction and more gender-neutral assessment items.

  19. Assessment report of research and development activities. Activity: advanced science research' (Interim report)

    International Nuclear Information System (INIS)

    2008-08-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consults an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for interim assessment of 'Advanced Science Research,' in accordance with General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program of the Advanced Science Research Center (hereinafter referred to as 'ASRC') during the period of two years from October 2005 to September 2007. The Committee evaluated the management and research activities of the ASRC based on the explanatory documents prepared by the ASRC, the oral presentations with questions-and-answers by the Director and the research group leaders, and interviews from group members through on-site visits by the Committee members. One CD-ROM is attached as an appendix. (J.P.N.)

  20. Bicarbonate catalysis of exchange synthesis of [51Cr]Cr(III)-EDTA and other chromium complexes

    International Nuclear Information System (INIS)

    Aronson, F.L.; Strashun, A.M.; Lopez, C.; Steigman, J.

    1993-01-01

    Exchange syntheses of trivalent chromium complexes often require heating, thus limiting tagging of heat-sensitive biological compounds with 51 Cr. Bicarbonate at pH 6, accelerates the formation of mM Cr-EDTA. Accordingly, room temperature catalysis with [ 51 Cr]Cr(III) at 10 -7 -10 -8 M was investigated. Complexes were successfully formed with EDTA and iminodiacetic acid (electrophoretic analysis) and acetylacetone and tropolone (analyzed by chloroform extraction). The formation of these complexes normally requires extensive heating. (author)

  1. Evaluation of calcium di-sodium EDTA intramuscular injection using gamma scintigraphy against heavy metal poisoning

    International Nuclear Information System (INIS)

    Kumar, N.; Soni, S.; Mehra, L.; Mittal, G.; Nishad, D.K.; Bhatnagar, A.; Singh, T.; Ahmad, F.J.

    2010-01-01

    Full text: Heavy metals become toxic when they are not metabolized by the body and accumulate in soft tissues. These metals may enter the body through food, water, air or absorption through skin when an individual is exposed to areas with high heavy metal content such as agriculture, pharmaceutical manufacturing, paint and heavy metal industries or residential settings. Majority of population commonly get affected by heavy metal poisoning. Heavy metal poisoning is more likely to result through inhalation or ingestion route. Aim of the present study is to provide an easy, effective and controlled chelating therapy against heavy metal using Ca-disodium EDTA intramuscular injection. Ca-disodium-EDTA and Sesame oil were procured from Merck, India and Sigma Aldrich, USA respectively. Ca-Na 2 EDTA radiolabeling with 99m Tc-pertechnetate was standardized using stannous ions as reducing agent. The hypothesis of present work is to maintain effective concentration of chelating agent in blood for prolong time period. To test this hypothesis, we studied 1% Ca-Na 2 EDTA blood bioavailability after intramuscular depot administration in new zealand white rabbit. The optimized radiolabeled intramuscular formulation was evaluated for its dissolution and permeation studies in isotonic buffer solution were envisaged through radiometry. Sub-acute toxicity studies were performed after a single dose intramuscular administration of 1% Ca-Na 2 EDTA in Sprague Dawley rats. Radiolabeled Ca-disodium-EDTA (>95% labeled) was found to be fairly stable up to 24 h in physiological solution (Serum) as well as in normal saline with negligible degradation of 2.5% and 5.0% respectively, thereby indicating high stability of radiolabeled product. In-vitro data indicates that control release pattern (Cmax 24 hrs) with effective concentration up to seven days. 99m Tc-CaNa 2 EDTA retention at depot site was estimated up to 3 days by scintigraphy. Subacute toxicity studies done by histopathological

  2. Assessing Gains in Science Teaching Self-Efficacy after Completing an Inquiry-Based Earth Science Course

    Science.gov (United States)

    Gray, Kyle

    2017-01-01

    Preservice elementary teachers are often required to take an Earth Science content course as part of their teacher education program but typically enter the course with little knowledge of key Earth Science concepts and are uncertain in their ability to teach science. This study investigated whether completing an inquiry-based Earth Science course…

  3. Glomerular filtration rate by {sup 51}chomium and {sup 113m}indium labeled EDTA in horses; Taxa de filtracao glomerular pelo EDTA marcado com {sup 51}cromo e com {sup 113m}indio em equinos

    Energy Technology Data Exchange (ETDEWEB)

    Maliska, C.; D' Almeida, J.; Pellegrini, P.M.; Schimit, T.S. [Hospital Central do Exercito (HCE), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Pinho, W.R. [Centro de Ensino Superior, Valenca, RJ (Brazil). Fac. de Medicina Veterinaria; Lima, J.E.T. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    2009-07-01

    The glomerular filtration rate was determined in nine healthy horses, six male and three female, aged two to 12-year-old, by means of {sup 51}Cr and {sup 113m}In labeled EDTA single injection technique. The glomerular filtration rate was calculated from the plasma disappearance curve and the volume of distribution of the radiotracer, {sup 51}Cr-EDTA or {sup 113m}In-EDTA. The result (mean +- standard deviation) was 148.80 +- 26.42 m L.min{sup -1}.100 kg. It is concluded that the measurement of glomerular filtration rate by {sup 51}Cr-EDTA or {sup 113m}In-EDTA by single injection technique eliminates the bladder catheterization, and for its simplicity, convenience, accuracy, and low dose of radiation, can be used in horses as a method of choice in clinical routine. (author)

  4. The Figured Worlds of High School Science Teachers: Uncovering Three-Dimensional Assessment Decisions

    Science.gov (United States)

    Ewald, Megan

    As a result of recent mandates of the Next Generation Science Standards, assessments are a "system of meaning" amidst a paradigm shift toward three-dimensional assessments. This study is motivated by two research questions: 1) how do high school science teachers describe their processes of decision-making in the development and use of three-dimensional assessments and 2) how do high school science teachers negotiate their identities as assessors in designing three-dimensional assessments. An important factor in teachers' assessment decision making is how they identify themselves as assessors. Therefore, this study investigated the teachers' roles as assessors through the Sociocultural Identity Theory. The most important contribution from this study is the emergent teacher assessment sub-identities: the modifier-recycler , the feeler-finder, and the creator. Using a qualitative phenomenological research design, focus groups, three-series interviews, think-alouds, and document analysis were utilized in this study. These qualitative methods were chosen to elicit rich conversations among teachers, make meaning of the teachers' experiences through in-depth interviews, amplify the thought processes of individual teachers while making assessment decisions, and analyze assessment documents in relation to teachers' perspectives. The findings from this study suggest that--of the 19 participants--only two teachers could consistently be identified as creators and aligned their assessment practices with NGSS. However, assessment sub-identities are not static and teachers may negotiate their identities from one moment to the next within socially constructed realms of interpretation known as figured worlds. Because teachers are positioned in less powerful figured worlds within the dominant discourse of standardization, this study raises awareness as to how the external pressures from more powerful figured worlds socially construct teachers' identities as assessors. For teachers

  5. Upholding science in health, safety and environmental risk assessments and regulations

    International Nuclear Information System (INIS)

    Aschner, Michael; Autrup, Herman N.; Berry, Sir Colin L.; Boobis, Alan R.; Cohen, Samuel M.; Creppy, Edmond E.; Dekant, Wolfgang; Doull, John; Galli, Corrado L.; Goodman, Jay I.; Gori, Gio B.; Greim, Helmut A.; Joudrier, Philippe

    2016-01-01

    A public appeal has been advanced by a large group of scientists, concerned that science has been misused in attempting to quantify and regulate unmeasurable hazards and risks. The appeal recalls that science is unable to evaluate hazards that cannot be measured, and that science in such cases should not be invoked to justify risk assessments in health, safety and environmental regulations. The appeal also notes that most national and international statutes delineating the discretion of regulators are ambiguous about what rules of evidence ought to apply. Those statutes should be revised to ensure that the evidence for regulatory action is grounded on the standards of the scientific method, whenever feasible. When independent scientific evidence is not possible, policies and regulations should be informed by publicly debated trade-offs between socially desirable uses and social perceptions of affordable precaution. This article explores the premises, implications and actions supporting the appeal and its objectives.

  6. A comparative study on EDTA and coronaliy advanced flap technique in the treatment of human gingival recessions

    Directory of Open Access Journals (Sweden)

    Khoshkhoo Nejad AA

    2003-08-01

    Full Text Available Statement of Problem: Treatment of gingival recession defect and covering denuded root surfaces is one of the goals in periodontal therapy and several surgical techniques have been suggested in this field."nPurpose: The aim of this study was to perform a comparison on coronaliy repositioned flap procedure with and without the use of ethylenediaminoteraacetic acid (EDTA. 24%, pH=7 in the treatment of"nrecession defects."nMaterial and Methods: In this randomized clinical trial study, 16 patients, aged 17-60 years, with a total of 27 miller class 1 isolated buccal gingival recession type defects of at least 2mm depth, and based"non special criteria were investigated. After initial therapy, surgical recession coverage was performed as coronaliy advanced flap technique and EDTA gel conditioning (test or coronaliy advanced flap alone"n(control. Clinical examination including assessments of oral hygiene, recession depth (RD, recession width (RW, width of keratinized tissue (KT, probing depth (PD and probing attachment level (PAL"nwere performed before and 1, 2, 3 months after surgical treatment."nResults: The mean of initial RD, RW, KT, PT and PAL in the test group was 2.73, 3.17, 3.13, 1.1 and 3.83mm respectively and in the control group was 2.56, 3.03, 3.67, 1.25, 3.92mm respectively. The mean of these parameters 3 months after treatment in the test group were changed to 0.46, 1.97, 2.65, 0.67, 1.1 mm, corresponding figures for control teeth were 0.85, 2.98, 2.75, 1, 1.94, respectively. At 3 months after treatment the mean root coverage amounted to 83% (test and 67% (control which was a statistically significant difference (P=0.0067. Although a significant clinical difference was observed regarinding root coverage level, all other clinical variables were not statistically different, with the exception of probing attachment level (P=0.005."nConclusion: It was suggested that EDTA gel (24%, PLT=7 for 3 minutes as root conditioner and the coronaliy

  7. A Science for Citizenship Model: Assessing the Effects of Benefits, Risks, and Trust for Predicting Students' Interest in and Understanding of Science-Related Content

    Science.gov (United States)

    Jack, Brady Michael; Lee, Ling; Yang, Kuay-Keng; Lin, Huann-shyang

    2017-10-01

    This study showcases the Science for Citizenship Model (SCM) as a new instructional methodology for presenting, to secondary students, science-related technology content related to the use of science in society not taught in the science curriculum, and a new approach for assessing the intercorrelations among three independent variables (benefits, risks, and trust) to predict the dependent variable of triggered interest in learning science. Utilizing a 50-minute instructional presentation on nanotechnology for citizenship, data were collected from 301 Taiwanese high school students. Structural equation modeling (SEM) and paired-samples t-tests were used to analyze the fitness of data to SCM and the extent to which a 50-minute class presentation of nanotechnology for citizenship affected students' awareness of benefits, risks, trust, and triggered interest in learning science. Results of SCM on pre-tests and post-tests revealed acceptable model fit to data and demonstrated that the strongest predictor of students' triggered interest in nanotechnology was their trust in science. Paired-samples t-test results on students' understanding of nanotechnology and their self-evaluated awareness of the benefits and risks of nanotechology, trust in scientists, and interest in learning science revealed low significant differences between pre-test and post-test. These results provide evidence that a short 50-minute presentation on an emerging science not normally addressed within traditional science curriculum had a significant yet limited impact on students' learning of nanotechnology in the classroom. Finally, we suggest why the results of this study may be important to science education instruction and research for understanding how the integration into classroom science education of short presentations of cutting-edge science and emerging technologies in support of the science for citizenship enterprise might be accomplished through future investigations.

  8. Microbial reduction of [Co(III)-EDTA]⁻ by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan.

    Science.gov (United States)

    Paraneeiswaran, Arunachalam; Shukla, Sudhir K; Prashanth, K; Rao, T Subba

    2015-01-01

    Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)-EDTA](-) reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)-EDTA](-) generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)-EDTA](2-) is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1mM [Co(III)-EDTA](-) in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)-EDTA](-) acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)-EDTA](-) reduction. More detailed investigations showed that after [Co(III)-EDTA](-) reduction, i.e. [Co(II)-EDTA](2-) complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. The Effects of EDTA and H2SO4 on Phyto-extraction of Pb from contaminated Soils by Radish

    Directory of Open Access Journals (Sweden)

    T. Mansouri

    2016-10-01

    Full Text Available Introduction: Soil contamination by heavy metals is one of the most important environmental concerns in many parts of the world. The remediation of soil contaminated with heavy metals is necessary to prevent the entry of these metals into the human food chain. Phyto-extraction is an effective, cheap and environmental friendly method which uses plants for cleaning contaminated soils. The plants are used for phytoremediation should have high potential for heavy metals uptake and produce enormous amount of biomass. A major problem facing phyto-extraction method is the immobility of heavy metals in soils. Chemical phyto-extraction is a method in which different acids and chelating substances are used to enhance the mobility of heavy metals in soil and their uptake by plants. The aims of this study were: (a to determine the potential of radish to extract Pb from contaminated soils and (b to assess the effects of different soil amendment (EDTA and H2SO4 to enhance plant uptake of the heavy metal and (c to study the effects of different levels of soil Pb on radish growth and Pb concentrations of above and below ground parts of this plant. Materials and Methods: Soil samples were air dried and passed through a 2 mm sieve and analysed for some physico-chemical properties and then artificially contaminated with seven levels of lead (0, 200, 400, 600, 800 and 1000 mg/kg using Pb(NO32 salt and then planted radish. During the growth period of radish and after the initiation of root growth, the plants were treated with three levels of sulfuric acid (0, 750 and 1500 mg/kg or three levels of EDTA (0, 10 and 20 mg/kg through irrigation water. At the end of growth period, the above and below ground parts of the plants were harvested, washed, dried and digested using a mixture of HNO3, HCl, and H2O2. The concentrations of Pb, N, P and K in plant extracts were measured. Statistical analysis of data was performed using MSTATC software and comparison of means was

  10. Assessment of an On-Line Earth System Science Course for Teachers

    Science.gov (United States)

    Shuster, R. D.; Grandgenett, N.

    2009-12-01

    The University of Nebraska at Omaha (UNO) has been offering on-line Earth System Science coursework to in-service teachers in Nebraska since 2002 through the Earth Systems Science Education Alliance (ESSEA). The goal of this course is to increase teacher content knowledge in Earth Science, introduce them to Earth System Science, and have them experience cooperative learning. We have offered three different ESSEA courses, with nearly 200 students having taken ESSEA courses at UNO for graduate credit. This effort represents a close collaboration between faculty and students from the Colleges of Arts & Sciences and Education, with periodic assistance of the local schools. In a follow-up study related to ESSEA coursework, UNO examined the perceptions of teachers who have taken the course and the potential benefits of the ESSEA courses for their own educational settings. The study was descriptive in design and included an online survey and a focus group. The results of these assessments indicated that the teachers felt very positive about what they learned in these courses, and in particular, how they could incorporate cooperative learning, inquiry based activities, and Earth System Science interconnections in their own classrooms. Problems identified by the teachers included a perceived lack of time to be able to integrate the learned material into their science curriculua and a lack of computer and/or technological resources in their educational settings. In addition, this Fall, we will conduct two teacher case studies, where we will interview two teachers, visit their classrooms, acquire work samples and talk with students. All of the results of our survey and focus group will be presented.

  11. Assessing Dimensions of Inquiry Practice by Middle School Science Teachers Engaged in a Professional Development Program

    Science.gov (United States)

    Lakin, Joni M.; Wallace, Carolyn S.

    2015-03-01

    Inquiry-based teaching promotes students' engagement in problem-solving and investigation as they learn science concepts. Current practice in science teacher education promotes the use of inquiry in the teaching of science. However, the literature suggests that many science teachers hold incomplete or incorrect conceptions of inquiry. Teachers, therefore, may believe they are providing more inquiry experiences than they are, reducing the positive impact of inquiry on science interest and skills. Given the prominence of inquiry in professional development experiences, educational evaluators need strong tools to detect intended use in the classroom. The current study focuses on the validity of assessments developed for evaluating teachers' use of inquiry strategies and classroom orientations. We explored the relationships between self-reported inquiry strategy use, preferences for inquiry, knowledge of inquiry practices, and related pedagogical content knowledge. Finally, we contrasted students' and teachers' reports of the levels of inquiry-based teaching in the classroom. Self-reports of inquiry use, especially one specific to the 5E instructional model, were useful, but should be interpreted with caution. Teachers tended to self-report higher levels of inquiry strategy use than their students perceived. Further, there were no significant correlations between either knowledge of inquiry practices or PCK and self-reported inquiry strategy use.

  12. Calcium EDTA toxicity: renal excretion of endogenous trace metals and the effect of repletion on collagen degradation in the rat.

    Science.gov (United States)

    Braide, V B

    1984-01-01

    Studies on total hydroxyproline concentrations in urine of rats infused with toxic doses of CaEDTA at 6 mmol/kg per 24 hr for 48 hr or injected i.p. with the chelate at 4.8 mmol/kg/day for 10 days, indicate a two- to six-fold increase in urine excretion of the imino acid. This is due to increased degradation of collagen induced by CaEDTA. CaEDTA infusion was also shown to enhance urine excretion of some trace metals (Zn, Mn, Cu and Fe). Rats infused with CaEDTA for 36 hr showed a gradual fall in concentration of hydroxyproline in the urine, following cessation of chelate infusion. The decline in hydroxyproline concentrations was faster in rats receiving trace metal (Zn, Co, Mn or Ni) treatment during the post-CaEDTA infusion period; suggesting that the metals may affect collage, making the protein less susceptible to degradation in the body.

  13. Comparison of EDTA- and citric acid-enhanced phytoextraction of heavy metals in artificially metal contaminated soil by Typha angustifolia.

    Science.gov (United States)

    Muhammad, Dawood; Chen, Fei; Zhao, Jing; Zhang, Guoping; Wu, Feibo

    2009-08-01

    A pot experiment was conducted to study the performance of EDTA and citric acid (CA) addition in improving phytoextraction of Cd, Cu, Pb, and Cr from artificially contaminated soil by T. angustifolia. T. angustifolia showed the remarkable resistance to heavy metal toxicity with no visual toxic symptom including chlorosis and necrosis when exposed to metal stress. EDTA-addition significantly reduced plant height and biomass, compared with the control, and stunted plant growth, while 2.5 and 5 mM CA addition induced significant increases in root dry weight. EDTA, and 5 and 10 mM CA significantly increased shoot Cd, Pb, and Cr concentrations compared with the control, with EDTA being more effective. At final harvest, the highest shoot Cd, Cr, and Pb concentrations were recorded in the treatment of 5 mM EDTA addition, while maximal root Pb concentration was found at the 2.5 mM CA treatment. However, shoot Cd accumulation in the 10 mM CA treatment was 36.9% higher than that in 2.5 mM EDTA, and similar with that in 10 mM EDTA. Shoot Pb accumulation was lower in 10 mM CA than that in EDTA treatments. Further, root Cd, Cu, and Pb accumulation of CA treatments and shoot Cr accumulation in 5 or 10 mM CA treatments were markedly higher than that of control and EDTA treatments. The results also showed that EDTA dramatically increased the dissolution of Cu, Cr, Pb, and Cd in soil, while CA addition had less effect on water-soluble Cu, Cr, and Cd, and no effect on Pb levels. It is suggested that CA can be a good chelator candidate for T. angustifolia used for environmentally safe phytoextraction of Cd and Cr in soils.

  14. Seeking missing pieces in science concept assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch analysis

    Science.gov (United States)

    Ding, Lin

    2014-02-01

    Discipline-based science concept assessments are powerful tools to measure learners' disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA) has been broadly used to gauge student conceptions of key electricity and magnetism (E&M) topics in college-level introductory physics courses. Differing from typical concept inventories that focus only on one topic of a subject area, BEMA covers a broad range of topics in the electromagnetism domain. In spite of this fact, prior studies exclusively used a single aggregate score to represent individual students' overall understanding of E&M without explicating the construct of this assessment. Additionally, BEMA has been used to compare traditional physics courses with a reformed course entitled Matter and Interactions (M&I). While prior findings were in favor of M&I, no empirical evidence was sought to rule out possible differential functioning of BEMA that may have inadvertently advantaged M&I students. In this study, we used Rasch analysis to seek two missing pieces regarding the construct and differential functioning of BEMA. Results suggest that although BEMA items generally can function together to measure the same construct of application and analysis of E&M concepts, several items may need further revision. Additionally, items that demonstrate differential functioning for the two courses are detected. Issues such as item contextual features and student familiarity with question settings may underlie these findings. This study highlights often overlooked threats in science concept assessments and provides an exemplar for using evidence-based reasoning to make valid inferences and arguments.

  15. Seeking missing pieces in science concept assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch analysis

    Directory of Open Access Journals (Sweden)

    Lin Ding

    2014-02-01

    Full Text Available Discipline-based science concept assessments are powerful tools to measure learners’ disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA has been broadly used to gauge student conceptions of key electricity and magnetism (E&M topics in college-level introductory physics courses. Differing from typical concept inventories that focus only on one topic of a subject area, BEMA covers a broad range of topics in the electromagnetism domain. In spite of this fact, prior studies exclusively used a single aggregate score to represent individual students’ overall understanding of E&M without explicating the construct of this assessment. Additionally, BEMA has been used to compare traditional physics courses with a reformed course entitled Matter and Interactions (M&I. While prior findings were in favor of M&I, no empirical evidence was sought to rule out possible differential functioning of BEMA that may have inadvertently advantaged M&I students. In this study, we used Rasch analysis to seek two missing pieces regarding the construct and differential functioning of BEMA. Results suggest that although BEMA items generally can function together to measure the same construct of application and analysis of E&M concepts, several items may need further revision. Additionally, items that demonstrate differential functioning for the two courses are detected. Issues such as item contextual features and student familiarity with question settings may underlie these findings. This study highlights often overlooked threats in science concept assessments and provides an exemplar for using evidence-based reasoning to make valid inferences and arguments.

  16. Metal decomposition rates or 111In-DPTA and EDTA conjugates of monoclonal antibodies in vivo

    International Nuclear Information System (INIS)

    Goodwin, D.A.; McTigue, M.; Chaovapong, W.; Meares, C.F.; McCall, M.J.

    1986-01-01

    We have studied the metal chelate decomposition rates in vivo in both 111 In-labelled benzyl EDTA and DTPA (bicyclic anhydride) conjugates of monoclonal anti-IAsup(k) IgG2a with identical Kα = 1 x 10 11 M -1 in both Ag + ve and Ag -ve mice. Twenty μCi was given i.v. and whole body counting done immediately and daily for 10 days. Half the mice in each group received i.p. injections of 5.0 mg CaNa 2 EDTA chase (Versenate) to facilitate urinary excretion of free 111 In. 50% of control 111 In-citrate remained at nine days but only 8% with chase. No significant loss of 111 In with chase occurred with C 1 substituted EDTA conjugates. A 19% increase in excretion was demonstrated with the chase in mice give DTPA conjugates (1.9% per day). While this will not interfere with radioimmunoimaging up to 24 h after injection, waiting periods of a week or longer will produce significant background of free 111 In in the reticuloendothelial system, RES. 111 In-EDTA stability was important in accurate metabolic rate measurements of anti-IAsup(k); T1/2 = 7.0 days in Ag-ve mice, T1/2 = 9.3 days in Ag-ve mice. (author)

  17. The effect of Emdogain and 24% EDTA root conditioning on periodontal healing of replanted dog's teeth.

    Science.gov (United States)

    Guzmán-Martínez, Nayelli; Silva-Herzog, Flores Daniel; Méndez, González Verónica; Martín-Pérez, Silvia; Cerda-Cristerna, Bernardino Isaac; Cohenca, Nestor

    2009-02-01

    Controversies still exist as for the regenerative role of enamel matrix derivatives and the need for removal of the periodontal ligament in replanted teeth. The purpose of this study was to evaluate the effect of Emdogain and 24% ethylenediamine tetraacetic acid (EDTA) root conditioning on periodontal healing of replanted dog's teeth. Teeth were extracted, endodontically treated and preconditioned as follows: group 1, Emdogain; group 2, Emdogain + EDTA and group 3, EDTA. Teeth were replanted after 30 min extraoral time, splinted for 15 days and animals sacrificed after 8 weeks of observation. Histological evaluation was performed using hematoxylin/eosin and Masson trichrome and results scored based on previously reported criteria for histological evaluation. Replacement root resorption was histologically diagnosed in all groups except in the negative control. A parametric analysis showed no statistically significant differences between experimental groups. Root preconditioning with Emdogain alone or in combination with 24% EDTA showed no evidence of regeneration of collagen fibers and consequently did not prevent the development of replacement root resorption on replanted dog's teeth.

  18. Effects of salinity and ethylenediamine tetra acetic acid (edta) on the ...

    African Journals Online (AJOL)

    In this study, the effects of the combined treatment of salinity and ethylenediamine tetra acetic acid (EDTA) on the germination of tomato seeds in Petri-dishes were compared to sole salinity. The treatments consisted of seven concentrations of sodium chloride (NaCL): 0 (control), 10, 50, 100, 250, 500 and 1000 mM.

  19. Ionic strength dependence of stability constants, complexation of Molybdenum(V I) with EDTA

    International Nuclear Information System (INIS)

    Zare, K.; Majlesi, K.; Teimoori, F.

    2002-01-01

    The stability constant of Mo (Vi) complexes with EDTA in aqueous solution has been determined by various authors using different techniques, but according to literature, no work has been reported on ionic strength dependence of these complexes. The present work describes the complexation of Mo (Vi) with EDTA in an ionic strength range of 0.1 to 1.0 moldm - 3 s odium perchlorate at 25 d ig C . The complexation of molybdenum (Vi) with EDTA was investigated in aqueous solution ranging in ph from 5 to 7 using UV spectrophotometric techniques. The composition of the complex was determined by the continuous variations method. It was shown that molybdenum (Vi) forms a 2:1 complex with EDTA of the type (MoO 3 ) 2 L - 4 a t ph =5.5 The parameters that define the dependence on ionic strength were analyzed with the aim of obtaining further information regarding to their variation as a function of the charges involved in the complex reaction. Moreover, a Debye-Huckel type equation makes it possible to estimate a stability constant at a fixed ionic strength when its value is known at another ionic media in the range of 0.1 3 . Therefore the evaluation may make a significant contribution solving many analytical and speciation problems

  20. Intraparticle diffusion of rare earths in porous ion exchanger rounding by EDTA solution

    International Nuclear Information System (INIS)

    Ling Daren; Xie Weije

    1991-01-01

    The self-diffusion of rate earth (RE) isotopes in porous cation exchangers with various radii or different pore structures rounding by EDTA solution was studied. The intraparticle effective diffusivity De was calculated by Boyd's method and Kataoka's bi-disperse pore model, and through further calculation the solid phase diffusivity Dg and macropore diffusivity Dp were also obtained. (author)

  1. [Evaluation of compounding EDTA and citric acid on remediation of heavy metals contaminated soil].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Cai, Wen-Min

    2014-08-01

    As commonly used eluents, Na2EDTA (EDTA) and citric acid (CA) have been widely applied in remediation of soil contaminated by heavy metals. In order to evaluate the removal of arsenic, cadmium, copper, and lead in the contaminated soil collected in a chemical plant by compounding EDTA and CA, a series of stirring experiments were conducted. Furthermore, the changes in speciation distribution of heavy metals before and after washing were studied. The results showed that, adopting the optimal molar ratio of EDTA/CA (1:1), when the pH of the solution was 3, the stirring time was 30 min, the stirring rate was 150 r x min(-1) and the L/S was 5:1, the removal rates of arsenic, cadmium, copper and lead could reach 11.72%, 43.39%, 24.36% and 27.17%, respectively. And it was found that after washing, for arsenic and copper, the content of acid dissolved fraction rose which increased the percentage of available contents. Fe-Mn oxide fraction mainly contributed to the removal of copper. As for cadmium, the percentages of acid dissolved fraction, Fe-Mn oxide fraction and organic fraction also decreased. In practical projects, speciation changes would pose certain environmental risk after soil washing, which should be taken into consideration.

  2. Super water-absorbing new material from chitosan, EDTA and urea.

    Science.gov (United States)

    Narayanan, Abathodharanan; Dhamodharan, Raghavachari

    2015-12-10

    A new, super water-absorbing, material is synthesized by the reaction between chitosan, EDTA and urea and named as CHEDUR. CHEDUR is probably formed through the crosslinking of chitosan molecules (CH) with the EDTA-urea (EDUR) adduct that is formed during the reaction. CHEDUR as well as the other products formed in control reactions are characterized extensively. CHEDUR exhibits a very high water uptake capacity when compared with chitosan, chitosan-EDTA adduct, as well as a commercial diaper material. A systematic study was done to find the optimum composition as well as reaction conditions for maximum water absorbing capacity. CHEDUR can play a vital role in applications that demand the rapid absorption and slow release of water such as agriculture, as a three in one new material for the slow release of urea, water and other metal ions that can be attached through the EDTA component. The other potential advantage of CHEDUR is that it can be expected to degrade in soil based on its chitosan backbone. The new material with rapid and high water uptake could also find potential applications as biodegradable active ingredient of the diaper material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. KINETICS OF THE OXIDATION OF FERROUS CHELATES OF EDTA AND HEDTA IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    WUBS, HJ; BEENACKERS, AACM

    1993-01-01

    The kinetics of the reaction of oxygen with ferrous chelates of EDTA and HEDTA was studied in a stirred cell reactor under industrial conditions. The temperature was varied from 20 to 60-degrees-C and the concentration of the ferrous chelate ranged from 0 to 100 mol/m3. The initial pH was 7.5. Under

  4. Synthesis, Characterization, and Magnetic Properties of Pure and EDTA-Capped NiO Nanosized Particles

    Directory of Open Access Journals (Sweden)

    H. T. Rahal

    2017-01-01

    Full Text Available The effect of ethylenediaminetetraacetic acid (EDTA as a capping agent on the structure, morphology, optical, and magnetic properties of nickel oxide (NiO nanosized particles, synthesized by coprecipitation method, was investigated. Nickel chloride hexahydrate and sodium hydroxide (NaOH were used as precursors. The resultant nanoparticles were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, and scanning electron microscopy (SEM. XRD patterns showed that NiO have a face-centered cubic (FCC structure. The crystallite size, estimated by Scherrer formula, has been found in the range of 28–33 nm. It is noticed that EDTA-capped NiO nanoparticles have a smaller size than pure nanoparticles. Thus, the addition of 0.1 M capping agent EDTA can form a nucleation point for nanoparticles growth. The optical and magnetic properties were investigated by Fourier transform infrared spectroscopy (FTIR and UV-vis absorption spectroscopy (UV as well as electron paramagnetic resonance (EPR and magnetization measurements. FTIR spectra indicated the presence of absorption bands in the range of 402–425 cm−1, which is a common feature of NiO. EPR for NiO nanosized particles was measured at room temperature. An EPR line with g factor ≈1.9–2 is detected for NiO nanoparticles, corresponding to Ni2+ ions. The magnetic hysteresis of NiO nanoparticles showed that EDTA capping recovers the surface magnetization of the nanoparticles.

  5. EDTA functionalized magnetic nanoparticle as a multifunctional adsorbent for Congo red dye from contaminated water

    Science.gov (United States)

    Sahoo, Jitendra Kumar; Rath, Juhi; Dash, Priyabrat; Sahoo, Harekrushna

    2017-05-01

    The present work reports the applicability of magnetite iron nanoparticles (Fe3O4) functionalized with ethylenediaminetetraacetic acid (EDTA) as an efficient adsorbent for the removal of Congo red (CR) dye from contaminated water. Magnetic nanoparticles (Fe3O4) are prepared by chemical precipitation method in which Fe2+ and Fe3+ salt from aqueous solution were reacted in presence of ammonia solution. The surface of Fe3O4 nanoparticle was first coated with (3-aminopropyl) triethoxy silane (APTES) by a salinization reaction and then linked with EDTA via reaction between -NH2 and -COOH to form well dispersed surface functionalised biocompatible magnetic nanoparticles. The obtained EDTA functionalized magnetic nanoparticles are characterized in terms of their morphological, XRD, BET surface area analysis, Fourier transform infrared spectroscopy (FT-IR) and Vibrating sample magnetometer (VSM). The adsorption of CR on Fe3O4-APTES-EDTA nanocomposite corresponds well to the Langmuir model and the Freundlich model respectively. The adsorption processes for CR followed the pseudo-second-order model.

  6. The separation of heavy lanthanons with NH4-EDTA as the eluent. The ionites comparison

    International Nuclear Information System (INIS)

    Frank, B.; Wolodkiewicz, W.

    1980-01-01

    Using two types of cation exchangers: Zerolit 225 x 8 and Wofatit KPS there was carried out the comparison of the ion exchange separation efficiency of the rare earth elements. The solution of NH 4 -EDTA with increasing pH gradient was used as the eluent. In these conditions no distinct differences in the separation of rare earth elements were found. (author)

  7. Impedance response characteristics of iron oxide interface in the EDTA solutions

    International Nuclear Information System (INIS)

    Sawa, Tosio; Higuchi, Shigeo; Kataoka, Ichiro; Ito, Hisao.

    1986-01-01

    The relationship between the dissolution and the surface conditions of Fe 3 O 4 were studied in the various conditions of EDTA solutions by means of the A · C impedance measurement. From the experimental results obtained, surface layer of Fe 3 O 4 electrode can be expressed with electrical equivalent circuit that have capacitance and reaction resistance in the electrical double layer. In the Na 2 SO 4 solution without occuring dissolution, reaction resistance was estimated as 314 kΩ · cm 2 and capacitance was 203 μF/cm 2 . In the EDTA solutions, reaction resistance decreases along with dissolution of Fe 3 O 4 . The factors to make decrease reaction resistance are EDTA concentration, pH and temperature of the solutions. In contrast with this, the factor to increase it is dissolved oxygen in the solutions. The reciprocal value of reaction resistance agrees well with the rate of dissolution. On the other hand, when the electrode potential was maintained under the cathodic polarization in the EDTA solutions, impedances of electrode surface showed the lower value than that in the immersion condition. And apparent resistance came near to 0 at the potential of -2.0 V in all the range of frequency. Fe 3 O 4 electrodes pretreated with the cathodic polarization exhibited the characteristic impedance response that were caused by the change of electrode surface and the deposites such as iron hydroxide. (author)

  8. A pulse radiolysis study of the formation and reactions of reduced metal EDTA complexes

    International Nuclear Information System (INIS)

    Buitenhuis, R.

    1977-01-01

    The construction of a computerized pulse radiolysis system with available means appropriate for the wavelength interval between 300 and 1000 nm is described. The investigation of the radiolysis of aqueous solutions of EDTA complexes in the presence of alcohols is discussed

  9. Effect of citric acid and EDTA on chromium and nickel uptake and translocation by Datura innoxia

    International Nuclear Information System (INIS)

    Jean, Liliane; Bordas, Francois; Gautier-Moussard, Cecile; Vernay, Philippe; Hitmi, Adnane; Bollinger, Jean-Claude

    2008-01-01

    EDTA and citric acid were tested to solubilize metals and enhance their uptake by Datura innoxia, chosen because of its ability to accumulate and tolerate metals. Two application modes were used on an industrial soil contaminated mainly by Cr and Ni. The results showed that citric acid was the most effective at increasing the uptake of Cr and EDTA for Ni. These results are consistent with the effectiveness of both chelants in solubilizing metals from the soil. The translocation factor (TF) of Ni was 1.6- and 6.7-fold higher than the control, respectively, for one and two applications of 1 mmol kg -1 EDTA. After two applications of 5 and 10 mmol kg -1 citric acid, the TF of Cr increased 2- and 3.5-fold relative to the control. Whatever the concentration, the application of EDTA modified the plant physiology significantly. For citric acid this was only observed with the highest dose (10 mmol kg -1 ). - Chelant effectiveness in increasing chromium and nickel uptake by Datura innoxia is the result of the increase in translocation versus negative effect on plant physiology

  10. Effect of sugarcane vinasse and EDTA on cadmium phytoextraction by two saltbush plants.

    Science.gov (United States)

    Eissa, Mamdouh A

    2016-05-01

    Although the use of saltbush plants in metal phytoremediation is well known, there is little information about the impact of sugarcane vinasse (SCV) and EDTA on metal uptake. Heavily cadmium-polluted soil (38 mg kg(-1) Cd) was used in pot and incubation experiments to investigate the Cd phytoextraction potential of wavy saltbush (Atriplex undulata) and quail saltbush (Atriplex lentiformis). EDTA at rates of 3, 6, and 10 mM kg(-1) soil and SCV at rates of 7, 15, and 30 mL kg(-1) soil were added to the polluted soil. The application of EDTA significantly (P = 0.002) reduced the growth of saltbush plants; on the other hand, SCV improved the growth. Both EDTA and SCV increased the availability and root-to-shoot transfer of Cd. The plants of A. lentiformis grown on the soil amended with the highest rate of SCV were able to remove 20.4 % of the total soil Cd during a period of 9 months. Based on the obtained results, it may be concluded that A. lentiformis and sugarcane vinasse could be more effective in the phytoextraction of Cd from the polluted soils.

  11. Chelate-assisted phytoextraction: effect of EDTA and EDDS on copper uptake by Brassica napus L.

    Directory of Open Access Journals (Sweden)

    TIJANA M. ZEREMSKI-ŠKORIĆ

    2010-09-01

    Full Text Available Chelate-assisted phytoextraction is proposed as an effective approach for the removal of heavy metals from contaminated soil through the use of high biomass plants. The aim of the present study was to compare the efficiency of the two chelators: EDTA and biodegradable EDDS in enhancing Cu uptake and translocation by Brassica napus L. grown on moderately contaminated soil and treated with increasing concentrations of EDTA or EDDS. Increasing amounts of EDDS caused serious growth suppression of B. napus and an increase in shoot metal concentrations. Growth suppression limited the actual amount of phytoextracted Cu at high concentrations of EDDS. The maximum amount of extracted Cu was achieved by the application of 8.0 and 4.0+4.0 mmol kg-1 EDDS. The shoot Cu concentrations after EDTA application were much lower than with EDDS at the same doses. According to these experiments, EDTA does not appear to be an efficient amendment if Cu phytoextraction with B. napus is considered but EDDS is.

  12. Plasma Calcium, Inorganic Phosphate and Magnesium During Hypocalcaemia Induced by a Standardized EDTA Infusion in Cows

    Directory of Open Access Journals (Sweden)

    Enemark JMD

    2001-06-01

    Full Text Available The intravenous Na2EDTA infusion technique allows effective specific chelation of circulating Ca2+ leading to a progressive hypocalcaemia. Methods previously used were not described in detail and results obtained by monitoring total and free ionic calcium were not comparable due to differences in sampling and analysis. This paper describes a standardized EDTA infusion technique that allowed comparison of the response of calcium, phosphorus and magnesium between 2 groups of experimental cows. The concentration of the Na2EDTA solution was 0.134 mol/l and the flow rate was standardized at 1.2 ml/kg per hour. Involuntary recumbency occurred when ionised calcium dropped to 0.39 – 0.52 mmol/l due to chelation. An initial fast drop of ionized calcium was observed during the first 20 min of infusion followed by a fluctuation leading to a further drop until recumbency. Pre-infusion [Ca2+] between tests does not correlate with the amount of EDTA required to induce involuntary recumbence. Total calcium concentration measured by atomic absorption remained almost constant during the first 100 min of infusion but declined gradually when the infusion was prolonged. The concentration of inorganic phosphate declined gradually in a fluctuating manner until recumbency. Magnesium concentration remained constant during infusion. Such electrolyte responses during infusion were comparable to those in spontaneous milk fever. The standardized infusion technique might be useful in future experimental studies.

  13. Efektivitas KMK dan Na2 EDTA dalam Mengabsorbsi Paparan Merkuri pada Ikan Lele (Clarias batrachus

    Directory of Open Access Journals (Sweden)

    Tuti Hartati Siregar

    2010-12-01

    Full Text Available Penelitian ini dilaksanakan untuk mengamati efektivitas karboksimetil kitosan (KMK sebagai bahan pengkelat alami dan Na2 EDTA sebagai bahan pengkelat sintetis logam berat merkuri (Hg pada ikan lele. Ikan lele yang digunakan adalah jenis lele dumbo yang diperoleh dari Bogor. Ikan dipelihara dalam kolam berukuran 380 x 150 x 60 cm 3. Air kolam sebanyak 570 L yang berisi 200 ekor ikan lele dipapar dengan Hg 60–90 ppb secara bertahap selama 1 bulan dan penggantian air kolam dilakukan setiap minggu. Sebelum pemaparan dengan Hg dilakukan, ikan lele dikondisikan pada kolam percobaan selama 1 minggu. Pada minggu ke dua ikan dipapar merkuri 60 ppb, kemudian konsentrasi merkuri dinaikkan 15 ppb setiap minggu sampai dengan minggu ke empat. Pemaparan dihentikan setelah minggu ke empat. Setelah itu ikan dipanen kemudian difilet dan dikelat dengan cara direndam dalam larutan KMK dan Na 2EDTA masing-masing pada konsentrasi 0; 0,5; 1,0; dan 1,5% selama 0, 30, 60, dan 90 menit. Perendaman dalam air digunakan sebagai kontrol terhadap perlakuan tersebut. Setiap perlakuan diulang sebanyak 3 kali. Pengamatan yang dilakukan meliputi kandungan awal dan kandungan akhir Hg setelah perlakuan perendaman. Analisis dilakukan menggunakan instrumen AAS (Perkin Elmer tipe Aanalyst800. Hasil pengamatan menunjukkan bahwa perendaman dalam KMK dan Na 2 EDTA 0,5% selama 30 menit memberikan hasil yang terbaik, dan tidak ada perbedaan antara KMK dan Na2EDTA dalam fungsinya sebagai absorben logam berat.

  14. Role of CA-EDTA on the Synthesizing Process of Cerate-Zirconate Ceramics Electrolyte

    Directory of Open Access Journals (Sweden)

    Nur Athirah Abdullah

    2013-01-01

    Full Text Available The role of a combination between citric acid (CA and ethylenediaminetetra acetic acid (EDTA as chelating agents in preparation of BaCe0.54Zr0.36Y0.1O2.95 powder by a modified sol-gel method is reported. The precursor solutions were prepared from metal nitrate salts (M+, chelating agents (C, and ethylene glycol (EG at molar ratio of M+ : C : EG = 3 : 2 : 3. Chemical and phase transformation of samples during thermal decomposition were analyzed by thermogravimetric analysis (TGA and Fourier transform infrared (FTIR spectroscopy. TGA results show that the sample prepared by a combination of CA-EDTA exhibited the lowest thermal decomposition temperature, Ttd since there was no significant weight loss after 750°C. After calcined at 1100°C, the carbonates residue remained in the samples as proven by FTIR results. It was found that the used combination of CA-EDTA acts as a better combustion reagent to increase the reaction rate and influence the thermal decomposition behaviour compared to a single citric acid and EDTA, respectively. Apparently, calcination temperatures above 1100°C are needed to produce a pure perovskitic BaCe0.54Zr0.36Y0.1O2.95.

  15. Assessing the Credibility of Climate Science Information: A Roadmap for Educators

    Science.gov (United States)

    Mandia, S. A.

    2017-12-01

    Although there is an overwhelming scientific consensus that humans are driving modern day climate change, a significant portion of Americans are still not convinced. One reason for this gap in understanding results from a large body of misinformation that is easily accessible by students and educators. Here the author presents an effective teaching model to allow students to assess the credibility of organizations and their authors who publish climate science information aimed toward the general public.

  16. Engaging Oral Health Students in Learning Basic Science Through Assessment That Weaves in Personal Experience.

    Science.gov (United States)

    Leadbeatter, Delyse; Gao, Jinlong

    2018-04-01

    Learning basic science forms an essential foundation for oral health therapy and dentistry, but frequently students perceive it as difficult, dry, and disconnected from clinical practice. This perception is encouraged by assessment methods that reward fact memorization, such as objective examinations. This study evaluated use of a learner-centered assessment portfolio designed to increase student engagement with basic science in an oral health therapy program at the University of Sydney, Australia. The aim of this qualitative study based on focus groups was to investigate students' engagement with basic science courses following introduction of the portfolio. Three assessments were conducted in three subsequent semesters: one based on students' interest in everyday phenomena (one student, for example, explored why she had red hair); the second focussed on scientific evidence and understanding of systemic diseases; and the third explored relations between oral and general health. Students were encouraged to begin with issues from their personal experience or patient care, to focus on what they were curious about, and to ask questions they really cared about. Each student prepared a written report and gave an oral presentation to the entire cohort. After the portfolios were completed, the authors held focus groups with two cohorts of students (N=21) in 2016 and analyzed the results using Zepke's framework for student engagement research. The results showed that the students successfully interweaved personal experience into their studies and that it provided significant motivation for learning. The students described their learning in terms of connection to themselves, their peer community, and their profession. Many additional benefits were identified, from increased student engagement in all courses to appreciation of the relevance of basic science. The findings should encourage dental and allied dental educators to reconsider the effects of assessments and seek

  17. Assessment of Teaching Methods and Critical Thinking in a Course for Science Majors

    Science.gov (United States)

    Speck, Angela; Ruzhitskaya, L.; Whittington, A. G.

    2014-01-01

    Ability to think critically is a key ingredient to the scientific mindset. Students who take science courses may or may not be predisposed to critical thinking - the ability to evaluate information analytically. Regardless of their initial stages, students can significantly improve their critical thinking through learning and practicing their reasoning skills, critical assessments, conducting and reflecting on observations and experiments, building their questioning and communication skills, and through the use of other techniques. While, there are several of teaching methods that may help to improve critical thinking, there are only a few assessment instruments that can help in evaluating the efficacy of these methods. Critical thinking skills and improvement in those skills are notoriously difficult to measure. Assessments that are based on multiple-choice questions demonstrate students’ final decisions but not their thinking processes. In addition, during the course of studies students may develop subject-based critical thinking while not being able to extend the skills to the general critical thinking. As such, we wanted to design and conduct a study on efficacy of several teaching methods in which we would learn how students’ improve their thinking processes within a science discipline as well as in everyday life situations. We conducted a study among 20 astronomy, physics and geology majors-- both graduate and undergraduate students-- enrolled in our Solar System Science course (mostly seniors and early graduate students) at the University of Missouri. We used the Ennis-Weir Critical Thinking Essay test to assess students’ general critical thinking and, in addition, we implemented our own subject-based critical thinking assessment. Here, we present the results of this study and share our experience on designing a subject-based critical thinking assessment instrument.

  18. Transport of Sr 2+ and SrEDTA 2- in partially-saturated and heterogeneous sediments

    Science.gov (United States)

    Pace, M. N.; Mayes, M. A.; Jardine, P. M.; McKay, L. D.; Yin, X. L.; Mehlhorn, T. L.; Liu, Q.; Gürleyük, H.

    2007-05-01

    Strontium-90 has migrated deep into the unsaturated subsurface beneath leaking storage tanks in the Waste Management Areas (WMA) at the U.S. Department of Energy's (DOE) Hanford Reservation. Faster than expected transport of contaminants in the vadose zone is typically attributed to either physical hydrologic processes such as development of preferential flow pathways, or to geochemical processes such as the formation of stable, anionic complexes with organic chelates, e.g., ethylenediaminetetraacetic acid (EDTA). The goal of this paper is to determine whether hydrological processes in the Hanford sediments can influence the geochemistry of the system and hence control transport of Sr 2+ and SrEDTA 2-. The study used batch isotherms, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core. Isotherms and repacked column experiments suggested that the SrEDTA 2- complex was unstable in the presence of Hanford sediments, resulting in dissociation and transport of Sr 2+ as a divalent cation. A decrease in sorption with increasing solid:solution ratio for Sr 2+ and SrEDTA 2- suggested mineral dissolution resulted in competition for sorption sites and the formation of stable aqueous complexes. This was confirmed by detection of MgEDTA 2-, MnEDTA 2-, PbEDTA 2-, and unidentified Sr and Ca complexes. Displacement of Sr 2+ through a partially-saturated undisturbed core resulted in less retardation and more irreversible sorption than was observed in the saturated repacked columns, and model results suggested a significant reservoir (49%) of immobile water was present during transport through the heterogeneous layered sediments. The undisturbed core was subsequently disassembled along distinct bedding planes and subjected to sequential extractions. Strontium was unequally distributed between carbonates (49%), ion exchange sites (37%), and the oxide (14%) fraction. An inverse relationship between mass wetness and Sr suggested that

  19. Cd2+ and Zn2+ sorption on apatite in the presence of EDTA and humic substance

    Directory of Open Access Journals (Sweden)

    Viipsi K.

    2013-04-01

    Full Text Available The sorption of Cd2+ and Zn2+ on hydroxyapatite [HAP- Ca10(PO46(OH2] and fluorapatite [FAP- Ca10( PO46(F2] with different specific surface area and stoichiometry was investigated in batch experiments in the pH range 4 to 11 (25 ◦C; 0.1 M KNO3. The impact of different conditions was concerned: solution pH, the presence of complexing ligands (EDTA and humic substance and competing metal ions, as well as reaction kinetic and equilibrium conditions. To evaluate the reversibility of Cd2+ sorption onto HAP, desorption characteristics in water, Ca, EDTA, and HUM-solutions were determined. Additionally to solution analysis the surface composition of solid phases was analysed by X-Ray Photoelectron Spectroscopy XPS. The information from the chemical analyses was used to design an equilibration model that takes into account dissolution, surface potential, solution and surface complexation, as well as possible phase transformations. It was revealed that apatites effectively sorb Cd2+ and Zn2+ by ion exchange reactions on surface by formation of new surface phases. Using XPS the formation of a Me-enriched HAP surface was found, which was interpreted as the formation of a solid solution with the general formula: Ca8.4-xMex(HPO41.6(PO44.4(OH0.4. In a binary solution (Cd+Zn the competition of metals reduced individual sorbed amount compared with the single component solutions but the total adsorption maximum was approximately constant. The presence of EDTA reduces the metal sorption on apatite due to [CdEDTA]2- and [ZnEDTA]2- complexes and increases apatite solubility due to [CaEDTA]2- complex formation. The dissolved humic substance was bound on apatite in suspensions but the amount of Cd2+ bound was not changed. The results showed that the solution pH and the presence of complexing ligands have a significant effect on heavy metal sorption on apatite and must be considered if apatites are used as remediation agent. The proposed model can be used to predict

  20. Development and validation of an instrument to evaluate science teachers' assessment beliefs and practices

    Science.gov (United States)

    Genc, Evrim

    The primary purpose of this study was to develop a valid and reliable instrument to examine science teachers' assessment beliefs and practices in science classrooms. The present study also investigated the relationship between teachers' beliefs and practices in terms of assessment issues in science, their perceptions of the factors that influenced their assessment practices and their feelings towards high-stakes testing. The participants of the study were 408 science teachers teaching at middle and high school levels in the State of Florida. Data were collected through two modes of administration of the instrument as a paper-and-pencil and a web-based form. The response rate for paper-and-pencil administration was estimated as 68% whereas the response for the web administration was found to be 27%. Results from the various dimensions of validity and reliability analyses revealed that the 24 item-four-factor belief and practice measures were psychometrically sound and conceptually anchored measures of science teachers' assessment beliefs and self-reported practices. Reliability estimates for the belief measure ranged from .83 to .91 whereas alpha values for the practice measure ranged from .56 to .90. Results from the multigroup analysis supported that the instrument has the same theoretical structure across both administration groups. Therefore, future researchers may use either a paper-and-pencil or web-based format of the instrument. This study underscored a discrepancy between what teachers believe and how they act in classroom settings. It was emphasized that certain factors were mediating the dynamics between the belief and the practice. The majority of teachers reported that instruction time, class size, professional development activities, availability of school funding, and state testing mandates impact their assessment routines. Teachers reported that both the preparation process and the results of the test created unbelievable tension both on students and

  1. Performance-based alternative assessments as a means of eliminating gender achievement differences on science tests

    Science.gov (United States)

    Brown, Norman Merrill

    1998-09-01

    Historically, researchers have reported an achievement difference between females and males on standardized science tests. These differences have been reported to be based upon science knowledge, abstract reasoning skills, mathematical abilities, and cultural and social phenomena. This research was designed to determine how mastery of specific science content from public school curricula might be evaluated with performance-based assessment models, without producing gender achievement differences. The assessment instruments used were Harcourt Brace Educational Measurement's GOALSsp°ler: A Performance-Based Measure of Achievement and the performance-based portion of the Stanford Achievement Testspcopyright, Ninth Edition. The identified independent variables were test, gender, ethnicity, and grade level. A 2 x 2 x 6 x 12 (test x gender x ethnicity x grade) factorial experimental design was used to organize the data. A stratified random sample (N = 2400) was selected from a national pool of norming data: N = 1200 from the GOALSsp°ler group and N = 1200 from the SAT9spcopyright group. The ANOVA analysis yielded mixed results. The factors of test, gender, ethnicity by grade, gender by grade, and gender by grade by ethnicity failed to produce significant results (alpha = 0.05). The factors yielding significant results were ethnicity, grade, and ethnicity by grade. Therefore, no significant differences were found between female and male achievement on these performance-based assessments.

  2. An assessment of collections at the University of Wisconsin-Madison Health Sciences Libraries: drug resistance.

    Science.gov (United States)

    Bergen, P L; Nemec, D

    1999-01-01

    In December 1997, the authors completed an in-depth collection assessment project at the University of Wisconsin-Madison Health Sciences Libraries. The purpose was to develop a framework for future collection assessment projects by completing a multifaceted evaluation of the libraries' monograph and serial collections in the subject area of drug resistance. Evaluators adapted and synthesized several traditional collection assessment tools, including shelflist measurement, bibliography and standard list checking, and citation analysis. Throughout the project, evaluators explored strategies to overcome some of the problems inherent in the application of traditional collection assessment methods to the evaluation of biomedical collections. Their efforts resulted in the identification of standard monographs and core journals for the subject area, a measurement of the collections' strength relative to the collections of benchmark libraries, and a foundation for future collection development within the subject area. The project's primary outcome was a collection assessment methodology that has potential application to both internal and cooperative collection development in medical, pharmaceutical, and other health sciences libraries.

  3. Assessment of the Forensic Sciences Profession. A Survey of Educational Offerings in the Forensic Sciences. Volume I.

    Science.gov (United States)

    Field, Kenneth S.; And Others

    This survey of the educational offerings in the Forensic Sciences was initiated to identify institutions and agencies offering educational courses and/or programs in the forensic sciences and to evaluate the availability of these programs. The information gathered by surveying members of the American Academy of Forensic Sciences reveals that…

  4. Effectiveness of EDTA and Modified Salt Solution to Detach and Kill Cells from Enterococcus faecalis Biofilm.

    Science.gov (United States)

    de Almeida, Josiane; Hoogenkamp, Michel; Felippe, Wilson T; Crielaard, Wim; van der Waal, Suzette V

    2016-02-01

    Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and a modified salt solution (MSS) to detach bacteria from biofilms. Forty-eight-hour-old Enterococcus faecalis biofilms were grown on glass coverslips and then treated for 1 hour by immersion in 17% EDTA or MSS. Phosphate-buffered saline served as a negative control. Then, residual biofilm cells on the substrate and the detached cells in the supernatant were collected. Viability was verified by the colony-forming unit (CFU) counting method. Propidium monoazide (PMA) treatment in conjunction with quantitative polymerase chain reaction (qPCR) was also performed to detect the presence of E. faecalis 16S ribonucleic RNA genes. Data were analyzed using 1-way analysis of variance and Tukey or Kruskal-Wallis and Dunn tests. The Pearson R test evaluated the correlation between results from CFU and PMA (α = 5%). qPCR showed that EDTA detached 99% of biofilm cells, and MSS detached 94% of biofilm cells (both P < .001). In contrast to EDTA, MSS was highly antimicrobial. The treatment promoted an ample log 7 reduction of the attached cells (P < .001), and almost no live cells were detected in the supernatant (P < .001). Positive correlations between CFU and qPCR with PMA were observed (r = 0.959 and r = 0.729). EDTA detached cells in biofilms with a minor antimicrobial effect. Besides a great antimicrobial effect, MSS also detached biofilm cells. These dispersals of biofilms give insights into new endodontic biofilm removal strategies. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Cascadia GeoSciences: Community-Based Earth Science Research Focused on Geologic Hazard Assessment and Environmental Restoration.

    Science.gov (United States)

    Williams, T. B.; Patton, J. R.; Leroy, T. H.

    2007-12-01

    Cascadia GeoSciences (CG) is a new non-profit membership governed corporation whose main objectives are to conduct and promote interdisciplinary community based earth science research. The primary focus of CG is on geologic hazard assessment and environmental restoration in the Western U.S. The primary geographic region of interest is Humboldt Bay, NW California, within the southern Cascadia subduction zone (SCSZ). This region is the on-land portion of the accretionary prism to the SCSZ, a unique and exciting setting with numerous hazards in an active, dynamic geologic environment. Humboldt Bay is also a region rich in history. Timber harvesting has been occurring in California's coastal forestlands for approximately 150 years. Timber products transported with ships and railroads from Mendocino and Humboldt Counties helped rebuild San Francisco after the 1906 earthquake. Historic land-use of this type now commonly requires the services of geologists, engineers, and biologists to restore road networks as well as provide safe fish passage. While Humboldt Bay is a focus of some of our individual research goals, we welcome regional scientists to utilize CG to support its mission while achieving their goals. An important function of CG is to provide student opportunities in field research. One of the primary charitable contributions of the organization is a student grant competition. Funds for the student grant will come from member fees and contributions, as well as a percent of all grants awarded to CG. A panel will review and select the student research proposal annually. In addition to supporting student research financially, professional members of CG will donate their time as mentors to the student researchers, promoting a student mentor program. The Humboldt Bay region is well suited to support annual student research. Thorough research like this will help unravel some of the mysteries of regional earthquake-induced land-level changes, as well as possible fault

  6. Exploring pre-service science teachers' pedagogical capacity for formative assessment through analyses of student answers

    Science.gov (United States)

    Aydeniz, Mehmet; Dogan, Alev

    2016-05-01

    Background: There has been an increasing emphasis on empowering pre-service and in-service science teachers to attend student reasoning and use formative assessments to guide student learning in recent years. Purpose: The purpose of this study was to explore pre-service science teachers' pedagogical capacity for formative assessment. Sample: This study took place in Turkey. The participants include 53 pre-service science teachers in their final year of schooling. All but two of the participants are female. Design and methods: We used a mixed-methods methodology in pursing this inquiry. Participants analyzed 28 responses to seven two-tiered questions given by four students of different ability levels. We explored their ability to identify the strengths and weaknesses in students' answers. We paid particular attention to the things that the pre-service science teachers noticed in students' explanations, the types of inferences they made about students' conceptual understanding, and the affordances of pedagogical decisions they made. Results: The results show that the majority of participants made an evaluative judgment (i.e. the answer is correct or incorrect) in their analyses of students' answers. Similarly, the majority of the participants recognized the type of mistake that the students made. However, they failed to successfully elaborate on fallacies, limitations, or strengths in student reasoning. We also asked the participants to make pedagogical decisions related to what needs to be done next in order to help the students to achieve academic objectives. Results show that 8% of the recommended instructional strategies were of no affordance, 64% of low-affordance, and 28% were of high affordance in terms of helping students achieve the academic objectives. Conclusion: If our goal is to improve pre-service science teachers' noticing skills, and the affordance of feedback that they provide, engaging them in activities that asks them to attend to students' ideas

  7. Getting the full picture: Assessing the complementarity of citizen science and agency monitoring data

    Science.gov (United States)

    Loiselle, Steven; Ophof, Daniel; Thornhill, Ian

    2017-01-01

    While the role of citizen science in engaging the public and providing large-scale datasets has been demonstrated, the nature of and potential for this science to supplement environmental monitoring efforts by government agencies has not yet been fully explored. To this end, the present study investigates the complementarity of a citizen science programme to agency monitoring of water quality. The Environment Agency (EA) is the governmental public body responsible for, among other duties, managing and monitoring water quality and water resources in England. FreshWater Watch (FWW) is a global citizen science project that supports community monitoring of freshwater quality. FWW and EA data were assessed for their spatio-temporal complementarity by comparing the geographical and seasonal coverage of nitrate (N-NO3) sampling across the River Thames catchment by the respective campaigns between spring 2013 and winter 2015. The analysis reveals that FWW citizen science-collected data complements EA data by filling in both gaps in the spatial and temporal coverage as well as gaps in waterbody type and size. In addition, partial spatio-temporal overlap in sampling efforts by the two actors is discovered, but EA sampling is found to be more consistent than FWW sampling. Statistical analyses indicate that regardless of broader geographical overlap in sampling effort, FWW sampling sites are associated with a lower stream order and water bodies of smaller surface areas than EA sampling sites. FWW also samples more still-water body sites than the EA. As a possible result of such differences in sampling tendencies, nitrate concentrations, a measure of water quality, are lower for FWW sites than EA sites. These findings strongly indicate that citizen science has clear potential to complement agency monitoring efforts by generating information on freshwater ecosystems that would otherwise be under reported. PMID:29211752

  8. Getting the full picture: Assessing the complementarity of citizen science and agency monitoring data.

    Directory of Open Access Journals (Sweden)

    Jeneen Hadj-Hammou

    Full Text Available While the role of citizen science in engaging the public and providing large-scale datasets has been demonstrated, the nature of and potential for this science to supplement environmental monitoring efforts by government agencies has not yet been fully explored. To this end, the present study investigates the complementarity of a citizen science programme to agency monitoring of water quality. The Environment Agency (EA is the governmental public body responsible for, among other duties, managing and monitoring water quality and water resources in England. FreshWater Watch (FWW is a global citizen science project that supports community monitoring of freshwater quality. FWW and EA data were assessed for their spatio-temporal complementarity by comparing the geographical and seasonal coverage of nitrate (N-NO3 sampling across the River Thames catchment by the respective campaigns between spring 2013 and winter 2015. The analysis reveals that FWW citizen science-collected data complements EA data by filling in both gaps in the spatial and temporal coverage as well as gaps in waterbody type and size. In addition, partial spatio-temporal overlap in sampling efforts by the two actors is discovered, but EA sampling is found to be more consistent than FWW sampling. Statistical analyses indicate that regardless of broader geographical overlap in sampling effort, FWW sampling sites are associated with a lower stream order and water bodies of smaller surface areas than EA sampling sites. FWW also samples more still-water body sites than the EA. As a possible result of such differences in sampling tendencies, nitrate concentrations, a measure of water quality, are lower for FWW sites than EA sites. These findings strongly indicate that citizen science has clear potential to complement agency monitoring efforts by generating information on freshwater ecosystems that would otherwise be under reported.

  9. Getting the full picture: Assessing the complementarity of citizen science and agency monitoring data.

    Science.gov (United States)

    Hadj-Hammou, Jeneen; Loiselle, Steven; Ophof, Daniel; Thornhill, Ian

    2017-01-01

    While the role of citizen science in engaging the public and providing large-scale datasets has been demonstrated, the nature of and potential for this science to supplement environmental monitoring efforts by government agencies has not yet been fully explored. To this end, the present study investigates the complementarity of a citizen science programme to agency monitoring of water quality. The Environment Agency (EA) is the governmental public body responsible for, among other duties, managing and monitoring water quality and water resources in England. FreshWater Watch (FWW) is a global citizen science project that supports community monitoring of freshwater quality. FWW and EA data were assessed for their spatio-temporal complementarity by comparing the geographical and seasonal coverage of nitrate (N-NO3) sampling across the River Thames catchment by the respective campaigns between spring 2013 and winter 2015. The analysis reveals that FWW citizen science-collected data complements EA data by filling in both gaps in the spatial and temporal coverage as well as gaps in waterbody type and size. In addition, partial spatio-temporal overlap in sampling efforts by the two actors is discovered, but EA sampling is found to be more consistent than FWW sampling. Statistical analyses indicate that regardless of broader geographical overlap in sampling effort, FWW sampling sites are associated with a lower stream order and water bodies of smaller surface areas than EA sampling sites. FWW also samples more still-water body sites than the EA. As a possible result of such differences in sampling tendencies, nitrate concentrations, a measure of water quality, are lower for FWW sites than EA sites. These findings strongly indicate that citizen science has clear potential to complement agency monitoring efforts by generating information on freshwater ecosystems that would otherwise be under reported.

  10. Assessment of and Response to Data Needs of Clinical and Translational Science Researchers and Beyond

    Directory of Open Access Journals (Sweden)

    Hannah F. Norton

    2016-04-01

    Full Text Available Objective and Setting: As universities and libraries grapple with data management and “big data,” the need for data management solutions across disciplines is particularly relevant in clinical and translational science (CTS research, which is designed to traverse disciplinary and institutional boundaries. At the University of Florida Health Science Center Library, a team of librarians undertook an assessment of the research data management needs of CTS researchers, including an online assessment and follow-up one-on-one interviews. Design and Methods: The 20-question online assessment was distributed to all investigators affiliated with UF’s Clinical and Translational Science Institute (CTSI and 59 investigators responded. Follow-up in-depth interviews were conducted with nine faculty and staff members. Results: Results indicate that UF’s CTS researchers have diverse data management needs that are often specific to their discipline or current research project and span the data lifecycle. A common theme in responses was the need for consistent data management training, particularly for graduate students; this led to localized training within the Health Science Center and CTSI, as well as campus-wide training. Another campus-wide outcome was the creation of an action-oriented Data Management/Curation Task Force, led by the libraries and with participation from Research Computing and the Office of Research. Conclusions: Initiating conversations with affected stakeholders and campus leadership about best practices in data management and implications for institutional policy shows the library’s proactive leadership and furthers our goal to provide concrete guidance to our users in this area.

  11. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

    International Nuclear Information System (INIS)

    Li Jiahua; Sun Yuanyuan; Yin Ying; Ji Rong; Wu Jichun; Wang Xiaorong; Guo Hongyan

    2010-01-01

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L -1 medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L -1 medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d -1 pot -1 for the duration of Day 5-8 and 0.59 mg d -1 pot -1 for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  12. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

    Energy Technology Data Exchange (ETDEWEB)

    Li Jiahua [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Sun Yuanyuan [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Yin Ying; Ji Rong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Wu Jichun [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Wang Xiaorong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Guo Hongyan, E-mail: hyguo@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L{sup -1} medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L{sup -1} medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d{sup -1}pot{sup -1} for the duration of Day 5-8 and 0.59 mg d{sup -1}pot{sup -1} for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  13. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by autochthonous willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River.

    Science.gov (United States)

    Li, Jiahua; Sun, Yuanyuan; Yin, Ying; Ji, Rong; Wu, Jichun; Wang, Xiaorong; Guo, Hongyan

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L(-1) medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L(-1) medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71 mg d(-1) pot(-1) for the duration of Day 5-8 and 0.59 mg d(-1) pot(-1) for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River. Copyright 2010 Elsevier B.V. All rights

  14. Design and Assessment of Online, Interactive Tutorials That Teach Science Process Skills.

    Science.gov (United States)

    Kramer, Maxwell; Olson, Dalay; Walker, J D

    2018-06-01

    Explicit emphasis on teaching science process skills leads to both gains in the skills themselves and, strikingly, deeper understanding of content. Here, we created and tested a series of online, interactive tutorials with the goal of helping undergraduate students develop science process skills. We designed the tutorials in accordance with evidence-based multimedia design principles and student feedback from usability testing. We then tested the efficacy of the tutorials in an introductory undergraduate biology class. On the basis of a multivariate ordinary least-squares regression model, students who received the tutorials are predicted to score 0.82 points higher on a 15-point science process skill assessment than their peers who received traditional textbook instruction on the same topic. This moderate but significant impact indicates that well-designed online tutorials can be more effective than traditional ways of teaching science process skills to undergraduate students. We also found trends that suggest the tutorials are especially effective for nonnative English-speaking students. However, due to a limited sample size, we were unable to confirm that these trends occurred due to more than just variation in the student group sampled.

  15. View of Nature of Science (VNOS Form B: An Instrument for Assessing Preservice Teachers View of Nature of Science at Borneo University Tarakan

    Directory of Open Access Journals (Sweden)

    Listiani Listiani

    2017-03-01

    Full Text Available NOS form B is an instrument that has been developed and revised to assess the view of nature of science of preservice science teachers through nature of science aspects.Indeed, students and teachers have to have the view of nature of science to avoid misconceptions of science concepts. Unfortunately, research on the view of Nature of Science is less conducted in Indonesia. This is a qualitative research that was conducted in Borneo University Tarakan. Respondents are preservice biology teachers in the sixth semester. The first step of this research is translating and adapting the VNOS form B into Bahasa Indonesia to make sure that the instrument is culturally fit to Indonesian and the transadapted instrument then given to the respondents. The result shows that the VNOS form B can be applied to assess the view of nature of science of preservice biology teachers. However, the result also shows that most of preservice biology teachers have few understanding on aspects of nature of scince.

  16. Performance of an easy-to-use prediction model for renal patient survival: an external validation study using data from the ERA-EDTA Registry.

    Science.gov (United States)

    Hemke, Aline C; Heemskerk, Martin B A; van Diepen, Merel; Kramer, Anneke; de Meester, Johan; Heaf, James G; Abad Diez, José Maria; Torres Guinea, Marta; Finne, Patrik; Brunet, Philippe; Vikse, Bjørn E; Caskey, Fergus J; Traynor, Jamie P; Massy, Ziad A; Couchoud, Cécile; Groothoff, Jaap W; Nordio, Maurizio; Jager, Kitty J; Dekker, Friedo W; Hoitsma, Andries J

    2018-01-16

    An easy-to-use prediction model for long-term renal patient survival based on only four predictors [age, primary renal disease, sex and therapy at 90 days after the start of renal replacement therapy (RRT)] has been developed in The Netherlands. To assess the usability of this model for use in Europe, we externally validated the model in 10 European countries. Data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry were used. Ten countries that reported individual patient data to the registry on patients starting RRT in the period 1995-2005 were included. Patients prediction model was evaluated for the 10- (primary endpoint), 5- and 3-year survival predictions by assessing the calibration and discrimination outcomes. We used a data set of 136 304 patients from 10 countries. The calibration in the large and calibration plots for 10 deciles of predicted survival probabilities showed average differences of 1.5, 3.2 and 3.4% in observed versus predicted 10-, 5- and 3-year survival, with some small variation on the country level. The concordance index, indicating the discriminatory power of the model, was 0.71 in the complete ERA-EDTA Registry cohort and varied according to country level between 0.70 and 0.75. A prediction model for long-term renal patient survival developed in a single country, based on only four easily available variables, has a comparably adequate performance in a wide range of other European countries. © The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Determinação do teor de edta remanescente em soluções de limpeza de equipamentos industriais Determination of edta content in cleaning solutions after their use in industrial equipaments

    Directory of Open Access Journals (Sweden)

    Arnaldo Antonio Rodella

    2007-08-01

    Full Text Available Cleaning solutions containing EDTA are widely employed to remove incrustation despite of the costs involved. The free content of EDTA in commercial solutions may be determined by mixing an aliquot to ammonium oxalate and using a standard calcium solution as titrant. The end-point is detected by the formation of insoluble calcium oxalate after all EDTA is complexed. A system for turbidimetric detection of the end-point was envisaged to substitute the visual detection, which impaired the analyses of dark samples. The proposed method was tested with real samples and good accuracy and precision was obtained.

  18. Comparison of Three Analytical Methods for Separation of Mineral and Chelated Fraction from an Adulterated Zn-EDTA Fertilizer

    International Nuclear Information System (INIS)

    Khan, M.S.; Qazi, M.A.; Khan, N.A.; Mian, S.M.; Ahmed, N.; Ahmed, N.

    2013-01-01

    Summary: Different analytical procedures are being employed in the world to quantify the chelated portion in a Zn-EDTA fertilizer. Agriculture Department, Government of the Punjab is following Shahid's analytical method in this regard. This method is based on Ion-chromatography (IC) that separates the mineral zinc (Zn) from an adulterated Zn-EDTA fertilizer sample i.e. mixture of mineral and chelated Zn fractions. To find out its effectiveness and suitability, this comparative study was carried out by analyzing adulterated, non-adulterated Zn-EDTA standard and Zn-EDTA samples taken from market in thrice following three methods namely Shahid's (IC) analytical method, Atomic Absorption Spectrophotometric (AAS) method based on the principle of precipitating the mineral Zn fraction at high pH value by using alkali solution of suitable concentration and analysis of filtrate containing only chelated fraction and Association of Official Analytical Chemists (AOAC) method FM-841 respectively. Adulterated Zn-EDTA samples were prepared by mixing of known quantity of mineral Zn with chelated Zn-EDTA standard. The results showed that Shahid's analytical method and AAS method, both successfully estimated the chelated fraction. The AOAC FM-841 method was insensitive to put a ceiling on the mineral fraction hence did not furnish the reliable results. The Shahid's analytical method was selected being equallyeffective to produce reliable results both for solid and liquid Zn-EDTA samples. The AAS method was comparable in only liquid samples. (author)

  19. Preparation of 99mTc-EDTA-MN and Its Bioimaging in Mouse

    Directory of Open Access Journals (Sweden)

    Yongshuai QI

    2015-07-01

    Full Text Available Background and objective Hypoxia is an important biological characteristics of solid tumor, it is not sensitive to radiotherapy and chemotherapy for which is the presence of hypoxic cell, thus increasing their resistance to conventional radiotherapy and chemotherapy, therefore, the detection of hypoxia degree of tumor tissue is of great significance. The hypoxia imaging of nuclear medicine can reflect the degree of tissue hypoxia, which can selectively retained on the hypoxic cells or tissues, including nitroimidazole and non nitroimidazole; the nitroimidazole is widely and deeply researched as hypoxic celles developer in China and abroad at present. The research about application of radionuclide labelled technique has clinical application value to develop the hypoxia imaging agent EDTA-MN complexes which was labeled. To study the feasibility of 99mTc by direct labeling method, the radiochemical properties evaluation of 99mTc-EDTA-MN, and observe the distribution characteristics of 99mTc radiolabeled EDTA-MN in the xenograft lung cancer nude mice bearing non-small cell lung cancer cell (A549, and provide experimental evidence for its further research and application. Methods The radiolabeling of EDTA-MN with 99mTc was performed with direct labeling method, respectively, on the reaction dosage (10 mg, 5 mg, 2 mg, stannous chloride dosage (8 mg/mL, 4 mg/mL, 2 mg/mL, mark system pH (2, 4, 5, 6 one by one test, using orthogonal design analysis, to find the optimal labeling conditions. Labelling rate, radiochemical purity, lipid-water partition coefficient and in vitro stability in normal saline (NS were determined by TLC and HPLC, and the preliminary study on the distribution of 99mTc-EDTA-MN in nude mice. Results The labeling rate of 99mTc-EDTA-MN with the best labeling conditions was (84.11±2.83%, and the radiochemical purity was higher than 90% by HPLC purification, without any notable decomposition at room temperature over a period of 12 h. The

  20. Biological degradation of EDTA in pulping effluents at higher pH - a laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Ek, M; Remberger, M; Allard, A S

    1999-01-01

    The biological degradation of EDTA at different pH, sludge load and sludge age has been investigated in laboratory experiments. The experiments showed that relatively fast degradation of EDTA in the form found in this waste water (from production of TMP) took place at least at pH around 8.5 with moderate COD load and high sludge age. In continuous reactors the degradation of EDTA in a pulp and paper waste water was 2-3 mg EDTA/g SS*day at both pH 7 and 8,5, and at sludge ages from 5 to 21 days. The degradation was dependent on sludge load, and no degradation was seen above 1 g COD/g SS*day. In kinetic experiments with half strength waste water the same degradation rate (1,5-2 mg EDTA/g SS*day) was found at pH 7 and at pH 8,5 with sludge of low age (9 and 5 days SRT). Much faster degradation was found at pH 8,5 with sludge of high age (21 days in the continuous experiment). The mean degradation rate was over 10 mg EDTA/g SS*day from 20 to 5 mg EDTA/l. v{sub max} was determined to be 35 mg EDTA/g SS*day and K{sub M} to 31 mg EDTA/l. COD removal was at least as good at pH 8,5 as at pH 7. Sludge properties were best at pH 8,5 and long sludge retention time (giving low sludge load). Both sludge volume index and residual suspended solids after sedimentation were lower than under normal conditions at pH 7. The direct cost for caustic lime would be about 15 SEK per ton of TMP, with a water like the one investigated here. This can vary a lot depending on starting pH and buffering capacity. Costs for addition of nitrogen source could probably be omitted, but this is normally not more than 1-2 SEK per ton of TMP. The extra need for oxygen in the treatment would not be more than some percent, but may be important if oxygen is limited. A substantial extra cost would be if the aeration volume has to be increased. According to the best results from the kinetic study, this would not be needed in an extended aeration activated plant with 2 days HRT and sludge concentrations of 2

  1. Climate research in the former Soviet Union. FASAC: Foreign Applied Sciences Assessment Center technical assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, R.G.; Baer, F.; Ellsaesser, H.W.; Harshvardhan; Hoffert, M.I.; Randall, D.A.

    1993-09-01

    This report assesses the state of the art in several areas of climate research in the former Soviet Union. This assessment was performed by a group of six internationally recognized US experts in related fields. The areas chosen for review are: large-scale circulation processes in the atmosphere and oceans; atmospheric radiative processes; cloud formation processes; climate effects of natural atmospheric disturbances; and the carbon cycle, paleoclimates, and general circulation model validation. The study found an active research community in each of the above areas. Overall, the quality of climate research in the former Soviet Union is mixed, although the best Soviet work is as good as the best corresponding work in the West. The best Soviet efforts have principally been in theoretical studies or data analysis. However, an apparent lack of access to modern computing facilities has severely hampered the Soviet research. Most of the issues considered in the Soviet literature are known, and have been discussed in the Western literature, although some extraordinary research in paleoclimatology was noted. Little unusual and exceptionally creative material was found in the other areas during the study period (1985 through 1992). Scientists in the former Soviet Union have closely followed the Western literature and technology. Given their strengths in theoretical and analytical methods, as well as their possession of simplified versions of detailed computer models being used in the West, researchers in the former Soviet Union have the potential to make significant contributions if supercomputers, workstations, and software become available. However, given the current state of the economy in the former Soviet Union, it is not clear that the computer gap will be bridged in the foreseeable future.

  2. Assessing the influence of Environmental Impact Assessments on science and policy: an analysis of the Three Gorges Project.

    Science.gov (United States)

    Tullos, Desiree

    2009-07-01

    The need to understand and minimize negative environmental outcomes associated with large dams has both contributed to and benefited from the introduction and subsequent improvements in the Environmental Impact Assessment (EIA) process. However, several limitations in the EIA process remain, including those associated with the uncertainty and significance of impact projections. These limitations are directly related to the feedback between science and policy, with information gaps in scientific understanding discovered through the EIA process contributing valuable recommendations on critical focus areas for prioritizing and funding research within the fields of ecological conservation and river engineering. This paper presents an analysis of the EIA process for the Three Gorges Project (TGP) in China as a case study for evaluating this feedback between the EIA and science and policy. For one of the best-studied public development projects in the world, this paper presents an investigation into whether patterns exist between the scientific interest (via number of publications) in environmental impacts and (a) the identification of impacts as uncertain or priority by the EIA, (b) decisions or political events associated with the dam, and (c) impact type. This analysis includes the compilation of literature on TGP, characterization of ecosystem interactions and responses to TGP through a hierarchy of impacts, coding of EIA impacts as "uncertain" impacts that require additional study and "priority" impacts that have particularly high significance, mapping of an event chronology to relate policies, institutional changes, and decisions about TGP as "events" that could influence the focus and intensity of scientific investigation, and analysis of the number of publications by impact type and order within the impact hierarchy. From these analyses, it appears that the availability and consistency of scientific information limit the accuracy of environmental impact

  3. science

    International Development Research Centre (IDRC) Digital Library (Canada)

    David Spurgeon

    Give us the tools: science and technology for development. Ottawa, ...... altered technical rela- tionships among the factors used in the process of production, and the en- .... to ourselves only the rights of audit and periodic substantive review." If a ...... and destroying scarce water reserves, recreational areas and a generally.

  4. Redistribution of fractions of zinc, cadmium, nickel, copper, and lead in contaminated calcareous soils treated with EDTA.

    Science.gov (United States)

    Jalali, Mohsen; Khanlari, Zahra V

    2007-11-01

    Effect of ethylene diamine tetraacetic acid (EDTA) on the fractionation of zinc (Zn), cadmium (Cd), nickel (Ni), copper (Cu), and lead (Pb) in contaminated calcareous soils was investigated. Soil samples containing variable levels of contamination, from 105.9 to 5803 mg/kg Zn, from 2.2 to 1361 mg/kg Cd, from 31 to 64.0 mg/kg Ni, from 24 to 84 mg/kg Cu, and from 109 to 24,850 mg/kg Pb, were subjected to EDTA treatment at different dosages of 0, 1.0, and 2.0 g/kg. Metals in the incubated soils were fractionated after 5 months by a sequential extraction procedure, in which the metal fractions were experimentally defined as exchangeable (EXCH), carbonate (CARB), Mn oxide (MNO), Fe oxide (FEO), organic matter (OM), and residual (RES) fractions. In contaminated soils without EDTA addition, Zn, Ni, Cu, and Pb were predominately present in the RES fraction, up to 60.0%, 32.3%, 41.1%, and 36.8%, respectively. In general, with the EDTA addition, the EXCH and CARB fractions of these metals increased dramatically while the OM fraction decreased. The Zn, Ni, Cu, and Pb were distributed mostly in RES, OM, FEO, and CARB fractions in contaminated soils, but Cd was found predominately in the CARB, MNO, and RES fractions. The OM fraction decreased with increasing amounts of EDTA. In the contaminated soils, EDTA removed some Pb, Zn, Cu, and Ni from MNO, FEO, and OM fractions and redistributed them into CARB and EXCH fractions. Based on the relative percent in the EXCH and CARB fractions, the order of solubility was Cd > Pb > Ni > Cu > Zn for contaminated soils, before adding of EDTA, and after adding of EDTA, the order of solubility was Pb > Cd > Zn > Ni > Cu. The risk of groundwater contamination will increase after applying EDTA and it needed to be used very carefully.

  5. SUPPORTING TEACHERS IN IMPLEMENTING FORMATIVE ASSESSMENT PRACTICES IN EARTH SYSTEMS SCIENCE

    Science.gov (United States)

    Harris, C. J.; Penuel, W. R.; Haydel Debarger, A.; Blank, J. G.

    2009-12-01

    An important purpose of formative assessment is to elicit student thinking to use in instruction to help all students learn and inform next steps in teaching. However, formative assessment practices are difficult to implement and thus present a formidable challenge for many science teachers. A critical need in geoscience education is a framework for providing teachers with real-time assessment tools as well as professional development to learn how to use formative assessment to improve instruction. Here, we describe a comprehensive support system, developed for our NSF-funded Contingent Pedagogies project, for addressing the challenge of helping teachers to use formative assessment to enhance student learning in middle school Earth Systems science. Our support system is designed to improve student understanding about the geosphere by integrating classroom network technology, interactive formative assessments, and contingent curricular activities to guide teachers from formative assessment to instructional decision-making and improved student learning. To accomplish this, we are using a new classroom network technology, Group Scribbles, in the context of an innovative middle-grades Earth Science curriculum called Investigating Earth Systems (IES). Group Scribbles, developed at SRI International, is a collaborative software tool that allows individual students to compose “scribbles” (i.e., drawings and notes), on “post-it” notes in a private workspace (a notebook computer) in response to a public task. They can post these notes anonymously to a shared, public workspace (a teacher-controlled large screen monitor) that becomes the centerpiece of group and class discussion. To help teachers implement formative assessment practices, we have introduced a key resource, called a teaching routine, to help teachers take advantage of Group Scribbles for more interactive assessments. Routine refers to a sequence of repeatable interactions that, over time, become

  6. Assessing middle school students` understanding of science relationships and processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schau, C.; Mattern, N.; Weber, R. [Univ. of New Nexico, Albuquerque, NM (United States); Minnick, K. [Minnick & Associates, Inc., Albuquerque, NM (United States)

    1994-09-01

    Our overall goal for this multi-year project is to develop and validate an alternative assessment format that effectively measures middle school students understanding of the relationships among selected science concepts and processes. In this project, we collaborate with the staff of the Los Alamos National Laboratory`s TOPS Program and the Programs participating teachers and their students. We also work with selected middle school science teachers from the TOPS program at Sandia National Laboratories. Our goal for this past year was to develop and field test informally a variety of potential measurement formats. This work has allowed us to identify formats to test during the validation phase of the project which will occur during the second year.

  7. Trichobezoar in Vagina: Assessment for Child Sexual Abuse and Diagnostic Result of Forensic Science.

    Science.gov (United States)

    Bağ, Özlem; Acar, Buğra Han; Öztürk, Şenol; Alşen, Sevay; Ecevit, Çiğdem

    2017-03-01

    Vaginal discharge and bleeding in children require a through and thoughtful evaluation to diagnose the underlying problem including infections, sexual abuse, and vaginal foreign bodies. We report a 6-year-old girl presenting with bloody vaginal discharge, carefully evaluated for sexual abuse, and finally diagnosed as a vaginal foreign body after vaginoscopy. A rolling hair ball was extracted from the vagina and was diagnosed as trichobezoar pathologically without any endo-ecto-mesodermal residual tissue. The hair ball was genetically detected and diagnosed to belong herself by containing no foreign structure. Child sexual abuse was ruled out by forensic interview at CAC and report of forensic science that reported genetic structure belonging to the child. Medicolegal assessment helped in final diagnosis to exclude child sexual abuse. © 2016 American Academy of Forensic Sciences.

  8. An Assessment of the Perception of Learning Gains of Freshmen Students in an Introductory Course in Nutrition and Food Science

    Science.gov (United States)

    Anderson, Alfred K.

    2006-01-01

    The assessment of learning gains of students in science and other disciplines is becoming a reality following the gradual shift from the traditional style of teaching to a curriculum-based assessment of learning outcomes. The degree to which students perceive to have obtained the outcomes of a course can be measured through an assessment of…

  9. Assessing and Improving L2 Graduate Students' Popular Science and Academic Writing in an Academic Writing Course

    Science.gov (United States)

    Rakedzon, Tzipora; Baram-Tsabari, Ayelet

    2017-01-01

    This paper reports a study using a quasi-experimental design to examine whether an academic writing course in English can improve graduate students' academic and popular science writing skills. To address this issue, we designed pre- and post-assessment tasks, an intervention assessment task and a scoring rubric. The pre- and post-assessment tasks…

  10. The Interactional Accomplishment of Not Knowing in Elementary School Science and Mathematics: Implications for Classroom Performance Assessment Practices

    Science.gov (United States)

    Reis, Giuliano; Barwell, Richard

    2013-01-01

    The day-to-day business of being a science or mathematics teacher involves the continuous assessment of students. This, in turn, is an inherently discursive process. The aim of the present study is to examine some of the specific discursive practices through which science and mathematics knowing is jointly produced through classroom interaction.…

  11. Chromium-51-EDTA clearance in adults with a single-plasma sample.

    Science.gov (United States)

    Mårtensson, J; Groth, S; Rehling, M; Gref, M

    1998-12-01

    In 1996, a committee on renal clearance recommended a mean sojourn time-based methodology for single-sample determination of plasma clearance of 99mTc-diethylenetriamine pentaacetic acid (DTPA) to be used on adults if the patient's glomerular filtration rate (GFR) is suspected to be >30 ml/min. The main purpose of this study was to derive a mean sojourn time-based formula for calculation of 51Cr-ethylenediamine tetraacetic acid (EDTA) clearance in adults. Two groups of patients with 51Cr-EDTA clearance (Cl) between 16 and 172 ml/min were studied. In Group I (n = 46), reference Cl was determined as a multiplasma sample, single-injection method (ClSM). Sixteen blood samples were drawn from 0 until 5 hr after a single intravenous injection of 51Cr-EDTA. In Group II (n = 1046), reference Cl was determined by the Brøchner-Mortensen four-sample clearance method (ClBM). The plasma time-activity curves of Group I were used to derive two mean sojourn time-based formulas (Formulas 1 and 2) for calculation of a single-sample clearance. Formula 1 was derived from the entire time-activity curve, whereas the derivation of Formula 2 used only the final slope of the time-activity curve. The accuracy of the two formulas and the Christensen and Groth 99mTc-DTPA formula was tested on Group II. Chromium-51-EDTA Cl calculated by Formula 1 was almost identical to the Cl calculated by the reference Cl method (r = 0.982; SDdiff = 5.82 ml/min). Both 51Cr-EDTA Cl calculated by Formula 2 and by the 99mTc-DTPA formula showed close correlation with the reference method (r = 0.976, r = 0.985, respectively) but systematically overestimated GFR for the whole range of clearance values by 3.5 and 3.2 ml/min (ptime methodology. The determination is marginally more accurate (ptime-activity curve than from only the final slope. The single-sample formula derived for determination of 99mTc-DTPA Cl tends slightly to overestimate GFR if used to calculate 51Cr-EDTA Cl.

  12. PENGARUH PENGOLAHAN DAN PENAMBAHAN Na2EDTA PADA TERIGU FORTIFIKASI TERHADAP KETERSEDIAAN BIOLOGIS SENG

    Directory of Open Access Journals (Sweden)

    Estu Nugroho

    2014-05-01

    Full Text Available ABSTRACTThe objective of this research was to analyze changes in bioavailability of zinc (Zn caused by addition of Na2EDTA and processing of fortified wheat flour. Bioavailability of zinc was tested by in vitro method as a simulation of human digestive track. The result showed that there was no significant difference in the bioavailability of zinc on wheat flour which is processed by frying (donuts, steaming (steamed bun, and baking (bread (p>0.05. However, there was a tendency to increase the bioavailability of wheat flour processed by frying (donuts and baking (bread when compared to the raw dough. Raw dough had bioavailability of zinc 13.29%, after frying (donut increase to 14.72%, and after baking (bread increase to 17.06%. The addition of Na2EDTA also did not increase bioavailability of zinc significantly for the three types of processing (p>0.05, despite increased bioavailability of zinc on the donuts by 4.67%.Keywords: bioavailability, in vitro, Na2EDTA, wheat flour, zincABSTRAKTujuan penelitian ini adalah menganalisis perubahan ketersediaan biologis seng (Zn yang terjadi akibat penambahan Na2EDTA dan pengolahan terigu yang difortifikasi. Uji ketersediaan biologis seng dilakukan secara in vitro dengan mensimulasikan pencernaan manusia. Hasil uji menunjukkan bahwa tidak terdapat perbedaan ketersediaan biologis seng yang nyata pada terigu yang digoreng (donat, dikukus (bakpau, ataupun dipanggang (roti (p>0.05. Namun, terdapat kecenderungan peningkatan ketersediaan biologis pada terigu yang diolah dengan cara digoreng (donat dan dipanggang (roti dibandingkan dengan adonan mentah. Adonan mentah memiliki nilai ketersediaan biologis seng sebesar 13.29%, setelah digoreng (donat memiliki nilai ketersediaan biologis seng sebesar 14.72% dan setelah dipanggang (roti memiliki nilai ketersediaan biologis seng sebesar 17.06%. Penambahan Na2EDTA juga tidak memberikan peningkatan ketersediaan biologis seng yang nyata pada ketiga jenis pengolahan yang

  13. Assessment of knowledge and skills in information literacy instruction for rehabilitation sciences students: a scoping review.

    Science.gov (United States)

    Boruff, Jill T; Harrison, Pamela

    2018-01-01

    This scoping review investigates how knowledge and skills are assessed in the information literacy (IL) instruction for students in physical therapy, occupational therapy, or speech-language pathology, regardless of whether the instruction was given by a librarian. The objectives were to discover what assessment measures were used, determine whether these assessment methods were tested for reliability and validity, and provide librarians with guidance on assessment methods to use in their instruction in evidence-based practice contexts. A scoping review methodology was used. A systematic search strategy was run in Ovid MEDLINE and adapted for CINAHL; EMBASE; Education Resources Information Center (ERIC) (EBSCO); Library and Information Science Abstracts (LISA); Library, Information Science & Technology Abstracts (LISTA); and Proquest Theses and Dissertations from 1990 to January 16, 2017. Forty articles were included for data extraction. Three major themes emerged: types of measures used, type and context of librarian involvement, and skills and outcomes described. Thirty-four measures of attitude and thirty-seven measures of performance were identified. Course products were the most commonly used type of performance measure. Librarians were involved in almost half the studies, most frequently as instructor, but also as author or assessor. Information literacy skills such as question formulation and database searching were described in studies that did not involve a librarian. Librarians involved in instructional assessment can use rubrics such as the Valid Assessment of Learning in Undergraduate Education (VALUE) when grading assignments to improve the measurement of knowledge and skills in course-integrated IL instruction. The Adapted Fresno Test could be modified to better suit the real-life application of IL knowledge and skills.

  14. Reactivity of OH· and e-aq from electron beam irradiation of aqueous solutions of EDTA and aminopolycarboxylic acids

    International Nuclear Information System (INIS)

    Vel Leitner, N.K.; Guilbault, I.; Legube, B.

    2003-01-01

    Electron beam irradiation of aqueous solutions of EDTA, EDDA NN', NTA, IDA and Cu-EDTA was performed in the presence of scavengers for the hydroxyl radicals (methanol) or for the solvated electrons (hydrogen peroxide). Experiments showed that for each molecule, the G-value decreases as the radiation dose increases from 1 to 25 kGy, and for EDTA, when the initial concentration decreases from 10 to 0.1 mmol l -1 . At pH 8 and for 5 kGy, the G-values of NTA, IDA, EDTA and EDDA NN' removal ascribed to OH · radicals are, respectively, 0.06, 0.06, 0.15 and 0.20 μmol J -1 , whereas for the solvated electrons the G-values were, respectively, 0.01, 0.01, 0.06 and 0.04 μmol J -1 . The rate constants of hydroxyl radicals and solvated electrons were determined by comparison with one competitor. For each active species (hydroxyl radical or solvated electron), the reactivity is connected to the number of nitrogen atoms and acetate groups. The rate constants of OH · radicals are above 10 10 and 8.6x10 9 l mol -1 s -1 for EDDA NN' and EDTA, respectively, 2.1x10 9 l mol -1 s -1 for IDA and 6.1x10 8 l mol -1 s -1 for NTA. The reactivity of solvated electrons is smaller and the rate constants are in the range 1.9x10 6 -3.7x10 6 l mol -1 s -1 for NTA, IDA and EDDA NN' and equal 1.4x10 7 l mol -1 s -1 for EDTA. The reactivity of the complex Cu-EDTA towards OH · does not differ to a large extent from EDTA whereas with e - aq the reactivity of Cu-EDTA is better than EDTA since k e - /Cu-EDTA reaches 2.2x10 9 l mol -1 s -1 . It follows that when both active entities (OH · and e - aq ) are involved in the electron beam irradiation process, the removal of free aminopolycarboxylic acids is mainly due to OH · radicals. However, the complex Cu-EDTA is concerned by both e - aq and OH · radicals

  15. Mobilisation of heavy metals into the urine by CaEDTA: relation to erythrocyte and plasma concentrations and exposure indicators.

    OpenAIRE

    Araki, S; Aono, H; Murata, K

    1986-01-01

    To investigate the effects of calcium disodium ethylenediamine tetra-acetate (CaEDTA) on the urinary excretion, erythrocyte, and plasma concentrations and exposure indicators of seven heavy metals, CaEDTA was administered by intravenous infusion to 20 workers exposed to lead, zinc, and copper. The workers' blood lead concentrations ranged from 22 to 59 micrograms/dl (mean 38 micrograms/dl (1.8 mumol/l]. The 24 hour urinary excretion of metals after CaEDTA administration (mobilisation yield) w...

  16. The optimal period of Ca-EDTA treatment for parthenogenetic activation of porcine oocytes during maturation culture

    OpenAIRE

    MORITA, Yasuhiro; TANIGUCHI, Masayasu; TANIHARA, Fuminori; ITO, Aya; NAMULA, Zhao; DO, Lanh Thi Kim; TAKAGI, Mitsuhiro; TAKEMOTO, Tatsuya; OTOI, Takeshige

    2016-01-01

    The changes triggered by sperm-induced activation of oocytes, which are required for normal oocyte development, can be mediated by other agents, thereby inducing the parthenogenesis. In this study, we exposed porcine oocytes to 1 mM Ca-EDTA, a metal-ion chelator, at various intervals during 48 hr of in vitro maturation to determine the optimum period of Ca-EDTA treatment for parthenogenetic activation. When the oocytes were cultured with or without Ca-EDTA from 36 hr (post-12), 24 hr (post-24...

  17. Assessing does not mean threatening: the purpose of assessment as a key determinant of girls' and boys' performance in a science class.

    Science.gov (United States)

    Souchal, Carine; Toczek, Marie-Christine; Darnon, Céline; Smeding, Annique; Butera, Fabrizio; Martinot, Delphine

    2014-03-01

    Is it possible to reach performance equality between boys and girls in a science class? Given the stereotypes targeting their groups in scientific domains, diagnostic contexts generally lower girls' performance and non-diagnostic contexts may harm boys' performance. The present study tested the effectiveness of a mastery-oriented assessment, allowing both boys and girls to perform at an optimal level in a science class. Participants were 120 boys and 72 girls (all high-school students). Participants attended a science lesson while expecting a performance-oriented assessment (i.e., an assessment designed to compare and select students), a mastery-oriented assessment (i.e., an assessment designed to help students in their learning), or no assessment of this lesson. In the mastery-oriented assessment condition, both boys and girls performed at a similarly high level, whereas the performance-oriented assessment condition reduced girls' performance and the no-assessment condition reduced boys' performance. One way to increase girls' performance on a science test without harming boys' performance is to present assessment as a tool for improving mastery rather than as a tool for comparing performances. © 2013 The British Psychological Society.

  18. Needs assessment of science teachers in secondary schools in Kumasi, Ghana: A basis for in-service education training programs at the Science Resource Centers

    Science.gov (United States)

    Gyamfi, Alexander

    The purpose of this study was twofold. First, it identified the priority needs common to all science teachers in secondary schools in Kumasi, Ghana. Second, it investigated the relationship existing between the identified priority needs and the teacher demographic variables (type of school, teacher qualification, teaching experience, subject discipline, and sex of teacher) to be used as a basis for implementing in-service education training programs at the Science Resource Centers in Kumasi Ghana. An adapted version of the Moore Assessment Profile (MAP) survey instrument and a set of open-ended questions were used to collect data from the science teachers. The researcher handed out one hundred and fifty questionnaire packets, and all one hundred and fifty (100%) were collected within a period of six weeks. The data were analyzed using descriptive statistics, content analysis, and inferential statistics. The descriptive statistics reported the frequency of responses, and it was used to calculate the Need Index (N) of the identified needs of teachers. Sixteen top-priority needs were identified, and the needs were arranged in a hierarchical order according to the magnitude of the Need Index (0.000 ≤ N ≤ 1.000). Content analysis was used to analyze the responses to the open-ended questions. One-way analysis of variance (ANOVA) was used to test the null hypotheses of the study on each of the sixteen identified top-priority needs and the teacher demographic variables. The findings of this study were as follows: (1) The science teachers identified needs related to "more effective use of instructional materials" as a crucial area for in-service training. (2) Host and Satellite schools exhibited significant difference on procuring supplementary science books for students. Subject discipline of teachers exhibited significant differences on utilizing the library and its facilities by students, obtaining information on where to get help on effective science teaching

  19. Gulf Coast Ecosystem Restoration Task Force---Gulf of Mexico Ecosystem Science Assessment and Needs

    Science.gov (United States)

    Walker, Shelby; Dausman, Alyssa M.; Lavoie, Dawn L.

    2012-01-01

    watersheds are managed to help support healthy and sustainable Gulf of Mexico ecosystems.Offshore environments are healthy and well managedEach working group was charged with defining their specific goal, describing the current conditions related to that goal (for example, the status of coastal habitats in the Gulf of Mexico), providing highlevel activities needed to further define and achieve the goal, with associated outcome-based performance indicators, and identifying the scientific gaps in understanding to accomplish the goal and implement the recommended activities. The overall scientific assessment reveals that the Gulf of Mexico ecosystem continues to suffer from extensive degradation, and action is necessary to develop a healthy, resilient, and sustainable Gulf of Mexico ecosystem. The six groups also were tasked with outlining the necessary monitoring, modeling, and research needs to aid in achieving the goals. Recognizing that (1) the scientific needs (monitoring, modeling, and research) overlap among many of the goals, and (2) an overarching scientific framework could be developed to implement the necessary science in support of the Strategy, a seventh group was created with several members from each of the original six working groups. This seventh group compiled all of the cross-cutting monitoring, modeling, and research needs previously identified by the individual groups. These scientific requirements are found in Chapter 5 of this document. The seventh group also has developed a Science Plan, outlined in Chapter 6. The Science Plan provides the basic science infrastructure to support the overall Gulf restoration program and Strategy. The Science Plan allows for the development of an iterative and flexible approach to adaptive management and decision-making related to restoration projects based on sound science that includes monitoring, modeling, and research. Taken in its entirety, this document helps to articulate the current state of the system and the

  20. Assessment of environments for Mars Science Laboratory entry, descent, and surface operations

    Science.gov (United States)

    Vasavada, Ashwin R.; Chen, Allen; Barnes, Jeffrey R.; Burkhart, P. Daniel; Cantor, Bruce A.; Dwyer-Cianciolo, Alicia M.; Fergason, Robini L.; Hinson, David P.; Justh, Hilary L.; Kass, David M.; Lewis, Stephen R.; Mischna, Michael A.; Murphy, James R.; Rafkin, Scot C.R.; Tyler, Daniel; Withers, Paul G.

    2012-01-01

    The Mars Science Laboratory mission aims to land a car-sized rover on Mars' surface and operate it for at least one Mars year in order to assess whether its field area was ever capable of supporting microbial life. Here we describe the approach used to identify, characterize, and assess environmental risks to the landing and rover surface operations. Novel entry, descent, and landing approaches will be used to accurately deliver the 900-kg rover, including the ability to sense and "fly out" deviations from a best-estimate atmospheric state. A joint engineering and science team developed methods to estimate the range of potential atmospheric states at the time of arrival and to quantitatively assess the spacecraft's performance and risk given its particular sensitivities to atmospheric conditions. Numerical models are used to calculate the atmospheric parameters, with observations used to define model cases, tune model parameters, and validate results. This joint program has resulted in a spacecraft capable of accessing, with minimal risk, the four finalist sites chosen for their scientific merit. The capability to operate the landed rover over the latitude range of candidate landing sites, and for all seasons, was verified against an analysis of surface environmental conditions described here. These results, from orbital and model data sets, also drive engineering simulations of the rover's thermal state that are used to plan surface operations.

  1. Consultation Needs Assessment in Kermanshah University of Medical Sciences: Viewpoints of Medical Students

    Directory of Open Access Journals (Sweden)

    Cyrus Jalili

    2018-01-01

    Full Text Available Introduction: Consultation can play an effective role in accommodating students to conditions and can be followed by academic achievement. This study was aimed to determine the consultation needs assessment among medical students in Kermanshah University of Medical Sciences (KUMS. Methods: This cross-sectional study was conducted among 300 students from undergraduate basic sciences of medical faculty of KUMS during 2016. Two structured questionnaires were applied for collecting data: demographics and consultation needs assessment. Data were analyzed by SPSS version 16 using bivariate correlations, t-test, and ANOVA test. Results: The age range of participants was 19 to 31 with the average of 22.78±2.30. Gender was associated significantly and statistically with the areas of individual growth and promotion needs, educational needs, employment needs and emotional needs; girls in these areas acquired a higher score compared to boys (P<0.05. Furthermore, the domain of individual growth and promotion needs acquired the highest score. Conclusion: Our findings indicated that most of the students' needs were in the field of individual and educational growth and promotion. Furthermore, the average scores of guidance and consultation needs assessment of the female students was higher, with the necessity of paying more attention to the consultation problems among them.

  2. Assessing the Life Science Knowledge of Students and Teachers Represented by the K-8 National Science Standards

    Science.gov (United States)

    Sadler, Philip M.; Coyle, Harold; Cook Smith, Nancy; Miller, Jaimie; Mintzes, Joel; Tanner, Kimberly; Murray, John

    2013-01-01

    We report on the development of an item test bank and associated instruments based on the National Research Council (NRC) K-8 life sciences content standards. Utilizing hundreds of studies in the science education research literature on student misconceptions, we constructed 476 unique multiple-choice items that measure the degree to which test…

  3. Design and Assessment of a General Science STEM Course with a Blended Learning Approach

    Science.gov (United States)

    Courtier, A. M.; Liu, J. C.; St John, K. K.

    2015-12-01

    Blended learning, a combination of classroom- and computer-mediated teaching and learning, is becoming prominent in higher education, and structured assessment is necessary to determine pedagogical costs and benefits. Assessment of a blended general education science class at James Madison University used a mixed-method causal-comparative design: in Spring 2014, two classes with identical content and similar groups of non-science majors were taught by the same instructor in either blended or full face-to-face formats. The learning experience of 160 students in the two classes was compared based on course and exam grades, classroom observation, and student survey results. Student acquisition of content in both classes was measured with pre-post tests using published concept inventories, and surveys, quizzes, and grade reports in the Blackboard learning management system were additionally used for data collection. Exams were identical between the two sections, and exam questions were validated in advance by a faculty member who teaches other sections of the same course. A course experience questionnaire was administered to measure students' personal experiences in both classes, addressing dimensions of good teaching, clear goals and standards, generic skills, appropriate assessment and workload, and emphasis on independence. Using a STEM classroom observation checklist, two researchers conducted in-class observations for four 75-minute face-to-face meetings with similar content focus in both classes, which allowed assessment of student engagement and participation. We will present details of the course design and research plan, as well as assessment results from both quantitative and qualitative analysis. The preliminary findings include slightly higher average grade distribution and more ready responses to in-class activities in the blended class.

  4. Hanford Site Cleanup Challenges and Opportunities for Science and Technology - A Strategic Assessment

    International Nuclear Information System (INIS)

    Johnson, W.; Reichmuth, B.; Wood, T.; Glasper, M.; Hanson, J.

    2002-01-01

    In November 2000, the U.S. Department of Energy (DOE) Richland Operations Office (RL) initiated an effort to produce a single, strategic perspective of RL Site closure challenges and potential Science and Technology (S and T) opportunities. This assessment was requested by DOE Headquarters (HQ), Office of Science and Technology, EM-50, as a means to provide a site level perspective on S and T priorities in the context of the Hanford 2012 Vision. The objectives were to evaluate the entire cleanup lifecycle (estimated at over $24 billion through 2046), to identify where the greatest uncertainties exist, and where investments in S and T can provide the maximum benefit. The assessment identified and described the eleven strategic closure challenges associated with the cleanup of the Hanford Site. The assessment was completed in the spring of 2001 and provided to DOE-HQ and the Hanford Site Technology Coordination Group (STCG) for review and input. It is the first step in developing a Site-level S and T strategy for RL. To realize the full benefits of this assessment, RL and Site contractors will work with the Hanford STCG to ensure: identified challenges and opportunities are reflected in project baselines; detailed S and T program-level road maps reflecting both near- and long-term investments are prepared using this assessment as a starting point; and integrated S and T priorities are incorporated into Environmental Management (EM) Focus Areas, Environmental Management Science Program (EMSP) and other research and development (R and D) programs to meet near-term and longer-range challenges. Hanford is now poised to begin the detailed planning and road mapping necessary to ensure that the integrated Site level S and T priorities are incorporated into the national DOE S and T program and formally incorporated into the relevant project baselines. DOE-HQ's response to this effort has been very positive and similar efforts are likely to be undertaken at other sites

  5. The effects of formative assessment on student self-regulation, motivational beliefs, and achievement in elementary science

    Science.gov (United States)

    King, Melissa Digennaro

    Goals 2000 set forth a bold vision for U.S. students: they would be "first in the world in science and mathematics" by the year 2000. Performance indicators such as the TIMSS-R (1999) and NAEP (2000) reports suggest that U.S. students have not yet reached that goal. This study intended to learn how specific assessment strategies might contribute to improved student performance in science. This quasi-experimental study investigated the effects of formative assessment with reflection on students' motivational beliefs, self-regulatory skills, and achievement in elementary science. The study aimed to find out whether and how classroom applications of formative assessment during science instruction might influence fifth-grade students' attitudes and self-perceptions about science learning, self-regulatory learning behaviors, and achievement. To explore the effects of the assessment intervention, the study utilized a mixed methods approach involving quantitative and qualitative investigations of treatment and control groups during a four-week intervention period. Quantitative measures included student self-report surveys administered pre- and post-treatment and an end-of-unit science test. Qualitative measures included classroom observations, student interviews (post-treatment), and a teacher interview (post-treatment). Findings indicated that the fifth-grade students in this study had positive attitudes toward science and high levels of self-efficacy for science. Results suggested that these elementary students employed a wide variety of cognitive and metacognitive strategies to support science learning. Findings revealed that these fifth graders believed formative assessment with reflection was beneficial for science learning outcomes. Research results did not show that the formative assessment intervention contributed to significant differences between treatment and control groups. However, the data revealed different levels of academic achievement and self

  6. Effect of EDTA and gypsum on self diffusion coefficient of zinc in alkali soil

    International Nuclear Information System (INIS)

    Gupta, G.N.; Deb, D.L.

    1981-01-01

    The effect of EDTA and gypsum application on the rate of zinc diffusion was studied in an alkali soil. Gypsum application at the rate of half gypsum requirement (GR) increased the apparent self diffusion coefficient of zinc (DaZn) and decreased the capacity factor (B) of soil. The higher rates (full GR and double GR) depressed the rate of zinc diffusion and increased the B value. Application of EDTA at the rate of 0.77 μeg -1 of soil produced 1600 and 24 fold increase in DaZn and DpZn values respectively and 100 times drop in B value. Addition of 55 ppm Zn to the soil significantly increased the DaZn and DpZn values. (author)

  7. Intestinal permeability to [51Cr]EDTA in children with cystic fibrosis

    International Nuclear Information System (INIS)

    Leclercq-Foucart, J.; Forget, P.; Sodoyez-Goffaux, F.; Zappitelli, A.

    1986-01-01

    Intestinal permeability was investigated in 14 children with cystic fibrosis making use of [ 51 Cr]EDTA as probe molecule. Ten normal young adults and 11 children served as controls. After oral administration of [ 51 Cr]EDTA, 24 h urine was collected. Urinary radioactivity was calculated and results expressed as percentage of oral dose excreted in 24 h urine. Mean and SEM were as follows: 2.51 +/- 0.21, 2.35 +/- 0.24, and 13.19 +/- 1.72 for control children, normal adults, and cystic fibrosis patients, respectively. The permeability differences between cystic fibrosis patients and either control children or control adults are significant (p less than 0.001)

  8. Use of EDTA for potentiometric back titration of rare earths and analysis of their mixtures

    International Nuclear Information System (INIS)

    Zayed, M.A.; Rizk, M.S.; Khalifa, H.; Omer, W.F.

    1987-01-01

    Advantage was taken of the stoichiometric reaction between mercury(II), rare earths, alkaline earths, heavy metal ions and EDTA in urotropine buffered media to determine rare earths by back-titration of excess EDTA in the course of estimating a variety of lanthanides or analysing their binary mixture with one of the alkaline earth metals by selective control of pH; or analysing their binary mixtures with heavy metals using fluoride as a good masking agent for rare earths; or analysing their ternary mixtures with both heavy and alkaline earth metals in two steps, one by selective control of pH and the other by masking of rare earths with fluoride at lower pH to estimate the heavy metal. The procedures given are simple, rapid and extremely reliable. 19 refs. (author)

  9. A novel biamperometric methodology for thorium determination by EDTA complexometric titration

    International Nuclear Information System (INIS)

    Jayachandran, K.; Gamare, J.S.; Nair, P.R.; Xavier, M.; Aggarwal, S.K.

    2012-01-01

    A biamperometric methodology is described for the determination of thorium by EDTA complexometric titration, based on the observed electrochemical behaviour of EDTA when the applied potential was ≥ 200 mV between the twin Pt electrodes. Studies carried out showed that a pH range of 2.4-2.7 was optimum for the determination. Accuracy and precision of the method were evaluated using different amounts of thorium ranging from 50 μg to 5 mg. Studies on the interference of uranium were carried out with different amounts of uranium ranging from 20 to 80% using the presently developed approach of biamperometry as well as the conventional indicator method. The method was employed for the determination of Th in (Th,U)O 2 samples containing different amounts of Th and U. (orig.)

  10. Adsorption of manganese(II) ions by EDTA-treated activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.Y.; Mazyck, D.W. [Jones Edmunds & Associates, Gainesville, FL (United States)

    2009-07-01

    The adsorption of manganese(II) ions from aqueous solution onto three different granular activated carbons treated with ethylenediamine tetraacetic acid (EDTA) and its sodium salt was investigated. Characterization of the chelate-treated carbons showed that EDTA altered the physical and chemical properties of the sorbents relative to their untreated counterparts. Furthermore, the modified sorbents exhibited a heightened capacity towards the adsorption of Mn(II) ions from aqueous media. Manganese(II) ion removal increased from 0 to 6.5 mg/g for the lignite coal-based sorbent, from 3.5 to 14.7 mg/g for the wood-based sorbent and from 1.3 to 7.9 mg/g for the bituminous coal-based sorbent. The increased removal is attributed, in part, to the creation of Lewis base sites that participate in covalent interactions and hydrolysis reactions.

  11. Structural modification of mordenite zeolite with Fe For the photo-degradation of EDTA

    International Nuclear Information System (INIS)

    Emara, Mostafa M.; Tourky, Amal S.M.; El-Moselhy, Medhat M.

    2009-01-01

    Fe 2+ was incorporated inside mordenite through ion exchange technique in aqueous solution. The amount of Fe loading was 25-100 wt %, using FeSO 4 .7H 2 O as precursor and Na-mordenite starting material Na-M. The Fe incorporated (Fe-M) thus prepared was characterized by XRD, FTIR and N 2 adsorption measurements. It was found that Fe mordenite retained the same structure as that for Na-mordenite which may indicate that Fe well dispersed into mordenite channels. BET indicated that Fe-M samples possessed higher surface area compared to the parent Na-M. Photocatalytic degradation of EDTA was carried out in presence of the prepared Fe-M catalysts. Effects of catalyst concentration and temperature were also studied. Thermodynamic parameters calculated for 50% Fe-M showed the highest catalytic activity toward EDTA degradation.

  12. Structural modification of mordenite zeolite with Fe For the photo-degradation of EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Emara, Mostafa M. [Chemistry Department, Faculty of Science (boys), Al-Azha University, Nasr city 11884, Cairo (Egypt); Tourky, Amal S.M. [Chemistry Department, Faculty of Science (Girls), Al-Azhar University, Nasr city, Cairo (Egypt); El-Moselhy, Medhat M., E-mail: medhatmohamed@yahoo.com [Chemistry Department, Faculty of Science (boys), Al-Azha University, Nasr city 11884, Cairo (Egypt)

    2009-07-15

    Fe{sup 2+} was incorporated inside mordenite through ion exchange technique in aqueous solution. The amount of Fe loading was 25-100 wt %, using FeSO{sub 4}.7H{sub 2}O as precursor and Na-mordenite starting material Na-M. The Fe incorporated (Fe-M) thus prepared was characterized by XRD, FTIR and N{sub 2} adsorption measurements. It was found that Fe mordenite retained the same structure as that for Na-mordenite which may indicate that Fe well dispersed into mordenite channels. BET indicated that Fe-M samples possessed higher surface area compared to the parent Na-M. Photocatalytic degradation of EDTA was carried out in presence of the prepared Fe-M catalysts. Effects of catalyst concentration and temperature were also studied. Thermodynamic parameters calculated for 50% Fe-M showed the highest catalytic activity toward EDTA degradation.

  13. Thermometric titration of thorium with EDTA in the presence of large excess of neutral sodium salts.

    Science.gov (United States)

    Doi, K

    1980-11-01

    The thermometric titration of Th(IV) in the presence of neutral sodium salts, sulphuric acid or acetic acid with EDTA has been studied. The effect of each on the observed heat values for the titration is discussed. For sodium perchlorate media, DeltaH values of -9 and -21 kJ/mole have been estimated for the formation of the Th(IV)-EDTA chelate at mu --> 0 and mu = 0.5 (NaClO(4)), respectively. The -DeltaH values increase steadily with increase in concentration of sodium perchlorate up to at least 3M. For the titration of Th(IV) in the presence of a large excess of sodium nitrate the use of sodium iodide as a masking reagent has been examined: large amounts of Bi and Cu(II) are masked and a masking effect is observed for small amounts of Ni.

  14. 99mTc-EDTA and 99mTc-DTPA complexes as hydrological tracers

    International Nuclear Information System (INIS)

    Dominguez, J.; Borroto, J.; Nazco, J.; Perez, E.; Gamboa, R.; Cruz, J.

    2002-01-01

    The [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1- were evaluated as radiotracers for short time hydrological studies. Their complex stability after labelling with 9.25 GBq of 99m Tc, the behaviour against pH variations, from 5 to 9, in simulated solutions and in natural river waters and the sorption of these compounds on the river sediments, were tested in laboratory experiments. Finally field double tracing experiments were carried out for each of labelling complexes and Rhodamine WT. From recovery calculations not losses of the 99m Tc activity were observed. The shape of the RTD curves of the [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1 were quite similar to the Rhodamine Wt ones. May be concluded that both complexes behaved conservatively on the studied environmental conditions. (author)

  15. Chromium 51 EDTA/technetium 99m MDP plasma ratio to measure total skeletal function

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, A.P.; Edwards, S.; Lazarus, C.R.; Malamitsi, J.; Maisey, M.N.; Mashiter, G.D.; Winn, P.J. (Guy' s Hospital, London (UK))

    1984-08-01

    A method is described for the quantitation of total skeletal activity during bone scans. The method requires a single plasma sample only, taken at the time of imaging. The ratio of % injected dose of /sup 51/Cr EDTA to that of /sup 99/Tcsup(m) MDP is calculated from this sample following combined injection of the two radiopharmaceuticals. The /sup 51/Cr EDTA level corrects for the glomerular filtration of /sup 99/Tcsup(m) MDP. Using this method, which only requires a gamma counter, significant differences from normal controls have been shown in patients with osteomalacia, renal osteodystrophy, Paget's disease and hypercalcaemia. The method provides routine quantitative data to add to the imaging information in the bone scan.

  16. Optical Manufacturing and Testing Requirements Identified by the NASA Science Instruments, Observatories and Sensor Systems Technology Assessment

    Science.gov (United States)

    Stahl, H. Philip; Barney, Rich; Bauman, Jill; Feinberg, Lee; Mcleese, Dan; Singh, Upendra

    2011-01-01

    In August 2010, the NASA Office of Chief Technologist (OCT) commissioned an assessment of 15 different technology areas of importance to the future of NASA. Technology assessment #8 (TA8) was Science Instruments, Observatories and Sensor Systems (SIOSS). SIOSS assess the needs for optical technology ranging from detectors to lasers, x-ray mirrors to microwave antenna, in-situ spectrographs for on-surface planetary sample characterization to large space telescopes. The needs assessment looked across the entirety of NASA and not just the Science Mission Directorate. This paper reviews the optical manufacturing and testing technologies identified by SIOSS which require development in order to enable future NASA high priority missions.

  17. Targeting change: Assessing a faculty learning community focused on increasing statistics content in life science curricula.

    Science.gov (United States)

    Parker, Loran Carleton; Gleichsner, Alyssa M; Adedokun, Omolola A; Forney, James

    2016-11-12

    Transformation of research in all biological fields necessitates the design, analysis and, interpretation of large data sets. Preparing students with the requisite skills in experimental design, statistical analysis, and interpretation, and mathematical reasoning will require both curricular reform and faculty who are willing and able to integrate mathematical and statistical concepts into their life science courses. A new Faculty Learning Community (FLC) was constituted each year for four years to assist in the transformation of the life sciences curriculum and faculty at a large, Midwestern research university. Participants were interviewed after participation and surveyed before and after participation to assess the impact of the FLC on their attitudes toward teaching, perceived pedagogical skills, and planned teaching practice. Overall, the FLC had a meaningful positive impact on participants' attitudes toward teaching, knowledge about teaching, and perceived pedagogical skills. Interestingly, confidence for viewing the classroom as a site for research about teaching declined. Implications for the creation and development of FLCs for science faculty are discussed. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(6):517-525, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

  18. Assessing predictors of science grades and career goals in university undergraduates

    Science.gov (United States)

    Patanella, Daniel Francis

    The utility of traditional predictors of both science grades and career goals (SAT and GPA) was compared to psychological predictors such as Piagetian stage (as measured by the Group Assessment of Logical Thinking), sex-role schema (as measured by the Bem Sex-Role Inventory, and self-schema in students enrolled in either psychology classes (n = 123) or biology classes (n = 56). While the overall predictive ability of the model was high (R = .73), the strongest predictors of grade in science class were traditional variables and not psychological ones as predicted. Prediction of career goal, while more modest (R = .19), was best served by the psychological variable of self-schema. Subsequent analyses indicated that Piagetian stage was best conceptualized as a mediating variable and that sex-role schema as measured played almost no role in either grade or career goal, as well as verifying the internal validity of the self-schema measure used. Biology students were more likely to possess a science self-schema than psychology students (chi2 (1,179) = 7.34, p < .01) and outperformed psychology students on the Piagetian questions (t(177) = 3.01, p < .01). Response latency was recorded for all participants' answer to the Piagetian questions; contrary to prediction however, the inclusion of response latency did not add to the predictive ability of the Piagetian measure used.

  19. Treatment of Ni-EDTA containing wastewater by electrocoagulation using iron scraps packed-bed anode.

    Science.gov (United States)

    Ye, Xiaokun; Zhang, Junya; Zhang, Yan; Lv, Yuancai; Dou, Rongni; Wen, Shulong; Li, Lianghao; Chen, Yuancai; Hu, YongYou

    2016-12-01

    The unique electrocoagulator proposed in this study is highly efficient at removing Ni-EDTA, providing a potential remediation option for wastewater containing lower concentrations of Ni-EDTA (Ni ≤ 10 mg L -1 ). In the electrocoagulation (EC) system, cylindrical graphite was used as a cathode, and a packed-bed formed from iron scraps was used as an anode. The results showed that the removal of Ni-EDTA increased with the application of current and favoured acidic conditions. We also found that the iron scrap packed-bed anode was superior in its treatment ability and specific energy consumption (SECS) compared with the iron rod anode. In addition, the packed density and temperature had a large influence on the energy consumption (ECS). Over 94.3% of Ni and 95.8% of TOC were removed when conducting the EC treatment at an applied current of 0.5 A, initial pH of 3, air-purged rate 0.2 L min -1 , anode packed density of 400 kg m -3 temperature of 313 K and time of 30 min. SEM analysis of the iron scraps indicated that the specific area of the anode increased after the EC. The XRD analysis of flocs produced during EC revealed that hematite (α-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) were the main by-products under aerobic and anoxic conditions, respectively. A kinetic study demonstrated that the removal of Ni-EDTA followed a first-order model with the current parameters. Moreover, the removal efficiency of real wastewater was essentially consistent with that of synthetic wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Field and laboratory evaluation of the mobility of cobalt-60/EDTA in an arid environment

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Swanson, J.L.; Kirkham, R.R.

    1983-02-01

    The ability of the organic complexant EDTA to enhance the mobility of cobalt-60 was investigated in both laboratory and field experiments. Laboratory tests consisted of short term (approximately 7 day) column and batch adsorption tests using soil from the Hanford site as well as long term (approximately 70 day) batch tests with Hanford soil and soils from Oak Ridge and Savannah River. In addition, two large scale tracer tests were conducted using Hanford soil. One used a large (1.6 m) laboratory column, spiked with cobalt-60/EDTA and the other was a field test conducted in an 8 m deep lysimeter. Enhanced mobility decreased sorption were observed in both column and batch tests when the cobalt-60/EDTA solutions contacted Hanford and Oak Ridge soil for only a few days. When long contact times were allowed (months) the Hanford soil showed large increases in sorption with time. The low sorption exhibited initially by the Oak Ridge soil increased slightly over time, however, the high sorption observed with the Savannah River soil remained constant with time. The reduced mobility, with time, observed in Hanford soils was confirmed in both the large scale laboratory and breaking down when contacted with Hanford and Savannah River soil and to a lesser extent, the Oak Ridge soil. It is not known at this time why the complex is breaking down or why the kinetics are different among the soils tested. The implication to waste management is that the potential for transport of cobalt by EDTA complexation may not be as serious as once thought

  1. Design of Ion-Exchange Resins Through EDTA and DTPA Modified Ligands

    Directory of Open Access Journals (Sweden)

    2014-07-01

    Catechol, resorcinol, and their admixtures with EDTA and DTPA moieties were converted into polymeric resins by alkaline polycondensation with formaldehyde. The resins were characterized by FTIR spectroscopy, elemental analysis, ion-exchange capacity, and distribution coefficient (D for heavy metal and radionuclide such as Cs and Sr. 137Cs and 90Sr constitutes a major source of heat in nuclear waste streams and in regards to recent nuclear event their remediation in complex solution – sea water - represent an important issue.

  2. Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

    International Nuclear Information System (INIS)

    Oliveira, G.M. de; Carlos, I.A.

    2009-01-01

    This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

  3. Using assessments to investigate and compare the nature of learning in undergraduate science courses.

    Science.gov (United States)

    Momsen, Jennifer; Offerdahl, Erika; Kryjevskaia, Mila; Montplaisir, Lisa; Anderson, Elizabeth; Grosz, Nate

    2013-06-01

    Assessments and student expectations can drive learning: students selectively study and learn the content and skills they believe critical to passing an exam in a given subject. Evaluating the nature of assessments in undergraduate science education can, therefore, provide substantial insight into student learning. We characterized and compared the cognitive skills routinely assessed by introductory biology and calculus-based physics sequences, using the cognitive domain of Bloom's taxonomy of educational objectives. Our results indicate that both introductory sequences overwhelmingly assess lower-order cognitive skills (e.g., knowledge recall, algorithmic problem solving), but the distribution of items across cognitive skill levels differs between introductory biology and physics, which reflects and may even reinforce student perceptions typical of those courses: biology is memorization, and physics is solving problems. We also probed the relationship between level of difficulty of exam questions, as measured by student performance and cognitive skill level as measured by Bloom's taxonomy. Our analyses of both disciplines do not indicate the presence of a strong relationship. Thus, regardless of discipline, more cognitively demanding tasks do not necessarily equate to increased difficulty. We recognize the limitations associated with this approach; however, we believe this research underscores the utility of evaluating the nature of our assessments.

  4. Science and environmental policy-making : bias-proofing the assessment process

    International Nuclear Information System (INIS)

    McKitrick, R.

    2005-01-01

    Politicians and policy-makers appeal to the concept of peer-reviewed research as a foundation for decision-making. However, peer review does not typically guarantee that data and methods are open to scrutiny or that results are reproducible. This paper argued that additional checks and balances are needed for scientific assessment reports when they are being used to justify major policy investments. The need for such mechanisms was examined with reference to the debate in climate change, which allowed the Intergovernmental Panel on Climate Change (IPCC) to downplay fundamental scientific uncertainties in research in order to claim that the 1990s were the warmest decade of the millennium. Two mechanisms were proposed to address biases in expert assessment panels. The creation of a scientific audit or permanent agency was recommended that would act independently of assessment panels to identify key studies influencing panel decisions to ensure that data are publicly available and that statistical methods are fully described and correctly implemented. The creation of a counterweight panel was also advised, which would then be convened to prepare the strongest possible counter argument to the conclusions of an assessment panel. It was concluded that, given the far-reaching implications of policy decisions that are based on expert assessments, audits and counterweight panels should be integrated into the process by which science is used to guide decision-making. 17 refs., 4 figs

  5. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, 76703 Queretaro (Mexico); Hernandez, G.; Solis, S. [UNAM, Campus Juriquilla, Centro de Geociencias, Boulevard Juriquilla 3001, 76230 Queretaro (Mexico); Garcia, R. [UNAM, Centro de Ciencias de la Atmosfera, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Pi, T., E-mail: ebustos@cideteq.mx [UNAM, Instituto de Geologia, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2014-07-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  6. Effects of EDTA on phytoextraction of heavy metals (Zn, Mn and Pb) from sludge-amended soil with Brassica napus.

    Science.gov (United States)

    Zaier, Hanen; Ghnaya, Tahar; Ben Rejeb, Kilani; Lakhdar, Abdelbasset; Rejeb, Salwa; Jemal, Fatima

    2010-06-01

    Sludge application is a reliable practice to ameliorate soil fertility. However, repetitive sludge addition represents a potential soil contamination source with heavy metals, which must be extracted. The aim of this study was to evaluate the capacity of Brassica napus to remove metals from soils amended with sludge, and to study the effect of EDTA on this process. Seedlings were cultivated in presence of sludge combined or not with EDTA. Results showed that sludge ameliorate significantly biomass production. This effect was accompanied with an increase in Pb, Zn and Mn shoot concentrations. EDTA application does not affect significantly plant growth. However, this chelator enhances shoot metals accumulation. It's therefore concluded that sludge has a beneficial effect on soil fertility, B. napus can be used for the decontamination of affected soils and that the EDTA addition increases the ability of B. napus to accumulate heavy metals. Published by Elsevier Ltd.

  7. Incorporation of rare-earth ions in Mg-Al layered double hydroxides: intercalation with an [Eu(EDTA)] - chelate

    Science.gov (United States)

    Li, Cang; Wang, Ge; Evans, David G.; Duan, Xue

    2004-12-01

    Reaction of an aqueous slurry of an Mg 2Al-NO 3 layered double hydroxide with a four-fold excess of Na[Eu(EDTA)] gives a material which analyses for Mg 0.68Al 0.32(OH) 2[Eu(EDTA)] 0.10(CO 3) 0.11·0.66H 2O. The interlayer spacing of the material is 13.8 Å, corresponding to a gallery height of 9.0 Å, which accords with the maximal dimensions (9-10 Å) of the anion in metal-EDTA complex salts as determined by single crystal X-ray diffraction. Geometrical considerations show that the charge density on the layered double hydroxide layers is too high to be balanced by intercalation of [Eu(EDTA)] - alone, necessitating the co-intercalation of carbonate ions which have a much higher charge density.

  8. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    International Nuclear Information System (INIS)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E.; Hernandez, G.; Solis, S.; Garcia, R.; Pi, T.

    2014-01-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  9. Influence of irradiation and Caf EDTA on the metabolism of nucleus acid of the different radiosensitive crops

    International Nuclear Information System (INIS)

    Song Daojun

    1997-01-01

    Irradiation and damage repair inhibitor (Caf and EDTA) post-treatment had a substantial effect on DNA and RNA content and DNA self-repairing synthesis. The experiment results showed the content of DNA and RNA increased with increase doses in the seedling hypocotyl of soybean and rape, Caf and EDTA post-treatment made them further higher than that of H 2 O-treatment. Meanwhile, the content of DNA and RNA in hypocotyl of soybean seedling was more than that of rape. Radioactive 3 H-TdR incorporation experiment showed γ-ray irradiated seeds induced unshunted DNA synthesis in the primary cultivated seeds of two crops, which was inhibited by Caf, EDTA and C + E post-treatment in the order of C + E>Caf>EDTA. Experiment also revealed irradiation and repair repressor post-treatment affected normal shunted DNA synthesis, postponed the cycle of cell division

  10. Uranium Leaching from Contaminated Soil Utilizing Rhamnolipid, EDTA, and Citric Acid

    Directory of Open Access Journals (Sweden)

    Sara Asselin

    2014-01-01

    Full Text Available Biosurfactants have recently gained attention as “green” agents that can be used to enhance the remediation of heavy metals and some organic matter in contaminated soils. The overall objective of this paper was to investigate rhamnolipid, a microbial produced biosurfactant, and its ability to leach uranium present in contaminated soil from an abandoned mine site. Soil samples were collected from two locations in northern Arizona: Cameron (site of open pit mining and Leupp (control—no mining. The approach taken was to first determine the total uranium content in each soil using a hydrofluoric acid digestion, then comparing the amount of metal removed by rhamnolipid to other chelating agents EDTA and citric acid, and finally determining the amount of soluble metal in the soil matrix using a sequential extraction. Results suggested a complex system for metal removal from soil utilizing rhamnolipid. It was determined that rhamnolipid at a concentration of 150 μM was as effective as EDTA but not as effective as citric acid for the removal of soluble uranium. However, the rhamnolipid was only slightly better at removing uranium from the mining soil compared to a purified water control. Overall, this study demonstrated that rhamnolipid ability to remove uranium from contaminated soil is comparable to EDTA and to a lesser extent citric acid, but, for the soils investigated, it is not significantly better than a simple water wash.

  11. Histological analysis of effects of 24% EDTA gel for nonsurgical treatment of periodontal tissues.

    Science.gov (United States)

    de Vasconcellos, Luana Marotta Reis; Ricardo, Lucilene Hernandes; Balducci, Ivan; de Vasconcellos, Luis Gustavo Oliveira; Carvalho, Yasmin Rodarte

    2006-12-01

    The aim of this study was to investigate, by means of histological and histomorphometric analysis, the effects of 24% ethylenediaminetetraacetic acid (EDTA) gel in periodontal tissue when used in combination with conventional periodontal treatment. Periodontitis was induced in the 2nd upper left permanent molars of 45 male Wistar rats by means of ligature. After 5 weeks, this was removed and debridement was performed. The animals were then randomly divided into 3 groups; group 1: mechanical treatment, group 2: mechanical treatment and EDTA gel application for 2 min, and group 3: mechanical treatment and placebo gel application for 2 min. After the treatment, rinsing was done with 0.9% saline solution for 1 min in all cases, followed by root notching in the deepest part of the pocket. After 4, 10, and 28 days the animals were sacrificed. The averages obtained were evaluated by means of test two-way analysis of variance (ANOVA) and Tukey statistical tests (P 24% EDTA gel did not interfere with periodontal tissue repair when used in combination with conventional periodontal treatment.

  12. Electrospun polyacrylonitrile nanofibers functionalized with EDTA for adsorption of ionic dyes

    Science.gov (United States)

    Chaúque, Eutilério F. C.; Dlamini, Langelihle N.; Adelodun, Adedeji A.; Greyling, Corinne J.; Ngila, J. Catherine

    2017-08-01

    The manipulation of nanofibers' surface chemistry could enhance their potential application toward the removal of ionic dyes in wastewater. For this purpose, surface modification of electrospun polyacrylonitrile (PAN) nanofibers with ethylenediaminetetraacetic acid (EDTA) and ethylenediamine (EDA) crosslinker was experimented. The functionalized EDTA-EDA-PAN nanofibers were characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) technique. The impregnation of EDA and EDTA chelating agents on the surface of PAN changed the distribution of nanofibers as proximity is increased (accompanied by reduced softness), but the nanofibrous structure of the pristine PAN nanofibers was not substantially altered. Adsorption equilibrium studies were performed with Freundlich, Langmuir and Temkin isotherm models with the former providing better correlation to the experimental data. The modified PAN nanofibers showed efficient sorption of methyl orange (MO) and reactive red (RR) from aqueous synthetic samples, evinced by the maximum adsorption capacities (at 25 °C) of 99.15 and 110.0 mg g-1, respectively. The fabricated nanofibers showed appreciable removal efficiency of the target dye sorptives from wastewater. However, the presence of high metal ions content affected the overall extraction of dyes from wastewater due to the depletion of the adsorbent's active adsorptive sites.

  13. Laser Monitoring Of Phytoextraction Enhancement Of Lead Contaminated Soil Adopting EDTA And EDDS

    Science.gov (United States)

    Hassan, M.; Abdelhamied, M.; Hanafy, A. H.; Fantoni, R.; Harith, M. A.

    2011-09-01

    Removal of heavy metals (HMs) such as Pb from soil, wastewater, and air is essential for environment and human health. Phytoremediation is a well established technology based on the use of certain green plants for contaminants removal from soil, wastewater as well as air. Scented geranium, Pelargonium zonal, is a flowering plant recently used in HMs removal from contaminated soil. In the present work, EDTA (ethylenediaminetetraacetic acid) and EDDS (S, S-ethylenediaminedisuccinic acid) were used as chemical assistants providing higher Pb availability for extraction by plant roots. Lead was artificially added to the planting media, peatmoss, at different concentrations. Laser induced breakdown spectroscopy (LIBS) was used to follow up Pb relative concentrations in peatmoss as well as plant shoots, at different sampling times during the experiment period. Laser induced chlorophyll fluorescence (LICF), has been also used to evaluate chlorophyll formation and photosynthetic apparatus status in geranium plants. Such measurements were performed on geranium plants grown under various Pb levels, as well as EDTA and EDDS combinations. The combined effect of EDTA and EDDS was found to enhance Pb extraction with time. Good correlation was found between LICF results and chlorophyll (a) (Chl.a) concentrations in plant tissues extracted by chemical analysis.

  14. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA.

    Science.gov (United States)

    Guardabassi, Luca; Ghibaudo, Giovanni; Damborg, Peter

    2010-06-01

    Minimum bactericidal concentrations (MBCs) of a commercial ear antiseptic containing chlorhexidine 0.15% and Tris-EDTA (Otodine) were determined by broth microdilution for 150 isolates representing the most common pathogens associated with canine otitis. The microorganisms were classified into three groups according to their levels of susceptibility. The most susceptible group included Staphylococcus pseudintermedius, Malassezia pachydermatis, Streptococcus canis and Corynebacterium auriscanis, which were generally killed by 1 : 64 dilution of the antiseptic product (MBC = 23/0.8 microg/mL of chlorhexidine/Tris-EDTA). The most resistant organism was Proteus mirabilis, which survived up to 1 : 8 dilution of the product (MBC = 375/12 microg/mL). Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus displayed intermediate MBCs ranging between 188/6 and 47/1.5 microg/mL. Interestingly, S. pseudintermedius was more susceptible than S. aureus, and no significant difference was observed between meticillin-resistant and meticillin-susceptible isolates within each species, indicating that antiseptic use is unlikely to co-select for meticillin resistance. Although the concentrations required for killing (MBCs) varied considerably with microorganism type, the combination of chlorhexidine 0.15% and Tris-EDTA was active against all the pathogens most commonly involved in canine otitis.

  15. Characterization and adsorption mechanism of Zn2+ removal by PVA/EDTA resin in polluted water

    International Nuclear Information System (INIS)

    Zhang Yun; Li Yanfeng; Yang Liuqing; Ma Xiaojie; Wang Liyuan; Ye Zhengfang

    2010-01-01

    Batch adsorption experiments were conducted using a PVA/EDTA resin as an adsorbent to adsorb Zn(II) ions from single component system in which experimental parameters were studied including solution pH, contact time, adsorbent dose and initial metal ions concentration. The equilibrium isotherms were determined at pH 6 under constant ionic strength and at different temperatures. The results showed that the maximum removal of Zn(II) (99.8%) with 1 g L -1 of sorbent was observed at 40 mg L -1 at an initial pH value of 6. Removals of about 60-70% occurred in 15 min, and equilibrium was attained at around 30 min. The equilibrium data for the adsorption of Zn(II) on PVA/EDTA resin was tested with various adsorption isotherm models among which three models were found to be suitable for the Zn(II) adsorption. In addition, the kinetic adsorption fitted well to the pseudo-second-order model and the corresponding rate constants were obtained. Thermodynamic aspects of the adsorption process were also investigated. Furthermore a higher desorption efficiency of Zn(II) from the PVA/EDTA resin using acid treatment was available by more than 95%.

  16. Preparation and radiopharmaceutical control of 169Yb EDTA an agent for kidney function and scintigraphy

    International Nuclear Information System (INIS)

    Gulbaba, G.; Ozker; Tomek, F.

    1976-01-01

    169 Yb was produced by thermal neutron irradiation of Yb 2 O 3 in 1 MW research reactor at Cekmece Nuclear Research Center. 169 Yb-EDTA complex was then prepared with a sodium salt of EDTA. Radionuclidic and radiochemical purities of the compound were determined by gama spectral analysis and radiochromatography-electrophoresis following preparation. Ionic Yb(III) which accumulates at bone and liver was not observed on the radiochromatographic and electrophoretic analysis of the final compound. There was no separation of the label for two months of examination in order to determine stability of the compound. In conclusion, the labeled compound has been prepared for use in the external scanning of kidney and determining the glomerular filtration rate. The label appears to be firmly bound so that the agent can be stored for a reasonably long period as 31 days half-life of 169 Yb permits. Administration of the compound is safe from the stand point of radiation dose since a 30 micro-Ci 169 Yb-EDTA for a glomerular filtration study delivers no more than 0.4 mrad whole-body and 5 mrad kidney dose. (author)

  17. ICT-infrastructures for hydrometeorology science and natural disaster societal impact assessment: the DRIHMS project

    Science.gov (United States)

    Parodi, A.; Craig, G. C.; Clematis, A.; Kranzlmueller, D.; Schiffers, M.; Morando, M.; Rebora, N.; Trasforini, E.; D'Agostino, D.; Keil, K.

    2010-09-01

    Hydrometeorological science has made strong progress over the last decade at the European and worldwide level: new modeling tools, post processing methodologies and observational data and corresponding ICT (Information and Communication Technology) technologies are available. Recent European efforts in developing a platform for e-Science, such as EGEE (Enabling Grids for E-sciencE), SEEGRID-SCI (South East Europe GRID e-Infrastructure for regional e-Science), and the German C3-Grid, have demonstrated their abilities to provide an ideal basis for the sharing of complex hydrometeorological data sets and tools. Despite these early initiatives, however, the awareness of the potential of the Grid technology as a catalyst for future hydrometeorological research is still low and both the adoption and the exploitation have astonishingly been slow, not only within individual EC member states, but also on a European scale. With this background in mind and the fact that European ICT-infrastructures are in the progress of transferring to a sustainable and permanent service utility as underlined by the European Grid Initiative (EGI) and the Partnership for Advanced Computing in Europe (PRACE), the Distributed Research Infrastructure for Hydro-Meteorology Study (DRIHMS, co-Founded by the EC under the 7th Framework Programme) project has been initiated. The goal of DRIHMS is the promotion of the Grids in particular and e-Infrastructures in general within the European hydrometeorological research (HMR) community through the diffusion of a Grid platform for e-collaboration in this earth science sector: the idea is to further boost European research excellence and competitiveness in the fields of hydrometeorological research and Grid research by bridging the gaps between these two scientific communities. Furthermore the project is intended to transfer the results to areas beyond the strict hydrometeorology science as a support for the assessment of the effects of extreme

  18. ICT-based hydrometeorology science and natural disaster societal impact assessment

    Science.gov (United States)

    Parodi, A.; Clematis, A.; Craig, G. C.; Kranzmueller, D.

    2009-09-01

    research by bridging the gaps between these two scientific communities. Furthermore the project is intended to transfer the results to areas beyond the strict hydrometeorology science as a support for the assessment of the effects of extreme hydrometeorological events on society and for the development of the tools improving the adaptation and resilience of society to the challenges of climate change.

  19. Final Report to the Department of the Energy for Project Entitled Rare Isotope Science Assessment Committee

    International Nuclear Information System (INIS)

    Shapero, Donald; Meyer, Timothy I.

    2007-01-01

    The Rare Isotope Science Assessment Committee (RISAC) was convened by the National Research Council in response to an informal request from the DOE's Office of Nuclear Physics and the White House Office of Management and Budget. The charge to the committee is to examine and assess the broader scientific and international contexts of a U.S.-based rare-isotope facility. The committee met for the first time on December 16-17, 2005, in Washington, DC, and held three subsequent meetings. The committee's's final report was publicly released in unedited, prepublication form on Friday, December 8, 2006. The report was published in full-color by the National Academies Press in April 2007. Copies of the report were distributed to key decision makers and stakeholders around the world.

  20. Image Quality Assessment of JPEG Compressed Mars Science Laboratory Mastcam Images using Convolutional Neural Networks

    Science.gov (United States)

    Kerner, H. R.; Bell, J. F., III; Ben Amor, H.

    2017-12-01

    The Mastcam color imaging system on the Mars Science Laboratory Curiosity rover acquires images within Gale crater for a variety of geologic and atmospheric studies. Images are often JPEG compressed before being downlinked to Earth. While critical for transmitting images on a low-bandwidth connection, this compression can result in image artifacts most noticeable as anomalous brightness or color changes within or near JPEG compression block boundaries. In images with significant high-frequency detail (e.g., in regions showing fine layering or lamination in sedimentary rocks), the image might need to be re-transmitted losslessly to enable accurate scientific interpretation of the data. The process of identifying which images have been adversely affected by compression artifacts is performed manually by the Mastcam science team, costing significant expert human time. To streamline the tedious process of identifying which images might need to be re-transmitted, we present an input-efficient neural network solution for predicting the perceived quality of a compressed Mastcam image. Most neural network solutions require large amounts of hand-labeled training data for the model to learn the target mapping between input (e.g. distorted images) and output (e.g. quality assessment). We propose an automatic labeling method using joint entropy between a compressed and uncompressed image to avoid the need for domain experts to label thousands of training examples by hand. We use automatically labeled data to train a convolutional neural network to estimate the probability that a Mastcam user would find the quality of a given compressed image acceptable for science analysis. We tested our model on a variety of Mastcam images and found that the proposed method correlates well with image quality perception by science team members. When assisted by our proposed method, we estimate that a Mastcam investigator could reduce the time spent reviewing images by a minimum of 70%.

  1. A Citizen Science Approach: A Detailed Ecological Assessment of Subtropical Reefs at Point Lookout, Australia.

    Science.gov (United States)

    Roelfsema, Chris; Thurstan, Ruth; Beger, Maria; Dudgeon, Christine; Loder, Jennifer; Kovacs, Eva; Gallo, Michele; Flower, Jason; Gomez Cabrera, K-le; Ortiz, Juan; Lea, Alexandra; Kleine, Diana

    2016-01-01

    Subtropical reefs provide an important habitat for flora and fauna, and proper monitoring is required for conservation. Monitoring these exposed and submerged reefs is challenging and available resources are limited. Citizen science is increasing in momentum, as an applied research tool and in the variety of monitoring approaches adopted. This paper aims to demonstrate an ecological assessment and mapping approach that incorporates both top-down (volunteer marine scientists) and bottom-up (divers/community) engagement aspects of citizen science, applied at a subtropical reef at Point Lookout, Southeast Queensland, Australia. Marine scientists trained fifty citizen scientists in survey techniques that included mapping of habitat features, recording of substrate, fish and invertebrate composition, and quantifying impacts (e.g., occurrence of substrate damage, presence of litter). In 2014 these volunteers conducted four seasonal surveys along semi-permanent transects, at five sites, across three reefs. The project presented is a model on how citizen science can be conducted in a marine environment through collaboration of volunteer researchers, non-researchers and local marine authorities. Significant differences in coral and algal cover were observed among the three sites, while fluctuations in algal cover were also observed seasonally. Differences in fish assemblages were apparent among sites and seasons, with subtropical fish groups observed more commonly in colder seasons. The least physical damage occurred in the most exposed sites (Flat Rock) within the highly protected marine park zones. The broad range of data collected through this top-down/bottom-up approach to citizen science exemplifies the projects' value and application for identifying ecosystem trends or patterns. The results of the project support natural resource and marine park management, providing a valuable contribution to existing scientific knowledge and the conservation of local reefs.

  2. Using Online Citizen Science to Assess Giant Kelp Abundances Across the Globe with Satellite Imagery

    Science.gov (United States)

    Byrnes, J.; Cavanaugh, K. C.; Haupt, A. J.; Trouille, L.; Rosenthal, I.; Bell, T. W.; Rassweiler, A.; Pérez-Matus, A.; Assis, J.

    2017-12-01

    Global scale long-term data sets that document the patterns and variability of human impacts on marine ecosystems are rare. This lack is particularly glaring for underwater species - even moreso for ecologically important ones. Here we demonstrate how online Citizen Science combined with Landsat satellite imagery can help build a picture of change in the dynamics of giant kelp, an important coastal foundation species around the globe, from the 1984 to the present. Giant kelp canopy is visible from Landsat images, but these images defy easy machine classification. To get useful data, images must be processed by hand. While academic researchers have applied this method successfully at sub-regional scales, unlocking the value of the full global dataset has not been possible until given the massive effort required. Here we present Floating Forests (http://floatingforests.org), an international collaboration between kelp forest researchers and the citizen science organization Zooniverse. Floating Forests provides an interface that allows citizen scientists to identify canopy cover of giant kelp on Landsat images, enabling us to scale up the dataset to the globe. We discuss lessons learned from the initial version of the project launched in 2014, a prototype of an image processing pipeline to bring Landsat imagery to citizen science platforms, methods of assessing accuracy of citizen scientists, and preliminary data from our relaunch of the project. Through this project we have developed generalizable tools to facilitate citizen science-based analysis of Landsat and other satellite and aerial imagery. We hope that this create a powerful dataset to unlock our understanding of how global change has altered these critically important species in the sea.

  3. Assessing the Science Knowledge of University Students: Perils, Pitfalls and Possibilities

    Science.gov (United States)

    Jones, Susan M.

    2014-01-01

    Science content knowledge is internationally regarded as a fundamentally important learning outcome for graduates of bachelor level science degrees: the Science Threshold Learning Outcomes (TLOs) recently adopted in Australia as a nationally agreed framework include "Science Knowledge" as TLO 2. Science knowledge is commonly assessed…

  4. Using case method to explicitly teach formative assessment in preservice teacher science education

    Science.gov (United States)

    Bentz, Amy Elizabeth

    The process of formative assessment improves student understanding; however, the topic of formative assessment in preservice education has been severely neglected. Since a major goal of teacher education is to create reflective teaching professionals, preservice teachers should be provided an opportunity to critically reflect on the use of formative assessment in the classroom. Case method is an instructional methodology that allows learners to engage in and reflect on real-world situations. Case based pedagogy can play an important role in enhancing preservice teachers' ability to reflect on teaching and learning by encouraging alternative ways of thinking about assessment. Although the literature on formative assessment and case methodology are extensive, using case method to explore the formative assessment process is, at best, sparse. The purpose of this study is to answer the following research questions: To what extent does the implementation of formative assessment cases in methods instruction influence preservice elementary science teachers' knowledge of formative assessment? What descriptive characteristics change between the preservice teachers' pre-case and post-case written reflection that would demonstrate learning had occurred? To investigate these questions, preservice teachers in an elementary methods course were asked to reflect on and discuss five cases. Pre/post-case data was analyzed. Results indicate that the preservice teachers modified their ideas to reflect the themes that were represented within the cases and modified their reflections to include specific ideas or examples taken directly from the case discussions. Comparing pre- and post-case reflections, the data supports a noted change in how the preservice teachers interpreted the case content. The preservice teachers began to evaluate the case content, question the lack of formative assessment concepts and strategies within the case, and apply formative assessment concepts and

  5. Quality in environmental science for policy: Assessing uncertainty as a component of policy analysis

    International Nuclear Information System (INIS)

    Maxim, Laura; Sluijs, Jeroen P. van der

    2011-01-01

    The sheer number of attempts to define and classify uncertainty reveals an awareness of its importance in environmental science for policy, though the nature of uncertainty is often misunderstood. The interdisciplinary field of uncertainty analysis is unstable; there are currently several incomplete notions of uncertainty leading to different and incompatible uncertainty classifications. One of the most salient shortcomings of present-day practice is that most of these classifications focus on quantifying uncertainty while ignoring the qualitative aspects that tend to be decisive in the interface between science and policy. Consequently, the current practices of uncertainty analysis contribute to increasing the perceived precision of scientific knowledge, but do not adequately address its lack of socio-political relevance. The 'positivistic' uncertainty analysis models (like those that dominate the fields of climate change modelling and nuclear or chemical risk assessment) have little social relevance, as they do not influence negotiations between stakeholders. From the perspective of the science-policy interface, the current practices of uncertainty analysis are incomplete and incorrectly focused. We argue that although scientific knowledge produced and used in a context of political decision-making embodies traditional scientific characteristics, it also holds additional properties linked to its influence on social, political, and economic relations. Therefore, the significance of uncertainty cannot be assessed based on quality criteria that refer to the scientific content only; uncertainty must also include quality criteria specific to the properties and roles of this scientific knowledge within political, social, and economic contexts and processes. We propose a conceptual framework designed to account for such substantive, contextual, and procedural criteria of knowledge quality. At the same time, the proposed framework includes and synthesizes the various

  6. Atmospheric Risk Assessment for the Mars Science Laboratory Entry, Descent, and Landing System

    Science.gov (United States)

    Chen, Allen; Vasavada, Ashwin; Cianciolo, Alicia; Barnes, Jeff; Tyler, Dan; Hinson, David; Lewis, Stephen

    2010-01-01

    In 2012, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems, by delivering the largest and most capable rover to date to the surface of Mars. As with previous Mars landers, atmospheric conditions during entry, descent, and landing directly impact the performance of MSL's EDL system. While the vehicle's novel guided entry system allows it to "fly out" a range of atmospheric uncertainties, its trajectory through the atmosphere creates a variety of atmospheric sensitivities not present on previous Mars entry systems and landers. Given the mission's stringent landing capability requirements, understanding the atmosphere state and spacecraft sensitivities takes on heightened importance. MSL's guided entry trajectory differs significantly from recent Mars landers and includes events that generate different atmospheric sensitivities than past missions. The existence of these sensitivities and general advancement in the state of Mars atmospheric knowledge has led the MSL team to employ new atmosphere modeling techniques in addition to past practices. A joint EDL engineering and Mars atmosphere science and modeling team has been created to identify the key system sensitivities, gather available atmospheric data sets, develop relevant atmosphere models, and formulate methods to integrate atmosphere information into EDL performance assessments. The team consists of EDL engineers, project science staff, and Mars atmospheric scientists from a variety of institutions. This paper provides an overview of the system performance sensitivities that have driven the atmosphere modeling approach, discusses the atmosphere data sets and models employed by the team as a result of the identified sensitivities, and introduces the tools used to translate atmospheric knowledge into quantitative EDL performance assessments.

  7. Assessment of oral health attitudes and behavior among students of Kuwait University Health Sciences Center.

    Science.gov (United States)

    Ali, Dena A

    2016-01-01

    The aims of this study were to assess attitudes and behavior of oral health maintenance among students in four faculties (Medicine, Dentistry, Pharmacy, and Allied Health) and to compare oral health attitudes and behavior of all students at Kuwait University Health Sciences Center (KUHSC) based on their academic level. Students enrolled in the Faculties of Dentistry, Medicine, Pharmacy, and Allied Health at KUHSC were evaluated regarding their oral health attitudes and behavior by an e-mail invitation with a link to the Hiroshima University Dental Behavior Inventory survey that was sent to all 1802 students with Kuwait University Health Sciences Center e-mail addresses. The data were analyzed for frequency distributions, and differences among the groups were assessed using the Mann-Whitney U test, Chi-square test, and Kruskal-Wallis test. P values less than 0.05 were considered to be statistically significant ( P < 0.05). The results of this study indicated that dental students achieved better oral health attitudes and behavior than that of their nondental professional fellow students ( P < 0.05). Students in advanced academic levels and female students demonstrated better oral health attitudes and behavior. Dental students and students who were in advanced levels of their training along with female students demonstrated better oral health practices and perceptions than students in lower academic levels and male students, respectively. Additional studies for investigating the effectiveness and identifying areas requiring modification within the dental curriculum at KUHSC may be warranted.

  8. Assessment of Kolb's Learning Styles among College Students of Qom University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    Elaheh rahiminia

    2017-06-01

    Full Text Available Background and Objective: Learning styles are effective factors in the learning. Learning is a relatively permanent change in the behavior or attitude of a person over time. Whereas improvement of existing conditions is pivotal in educational activities; therefore, the aim of this study was the assessment of stages and learning styles based on the Kolb theory among students of Qom University of Medical Sciences. Materials and Methods: This cross-sectional study was performed on 279 students of the QomUniversity of Medical Sciences, Iran in October 2015. The participants were selected using a stratified sampling method. The assessment instrument was the Kolb learning style inventory (KLSI V.3.1. Data analysis was performed by SPSS using descriptive statistics and Chi square test. Results: The mean age of students was 22.23±4.38 years, and the average grade was 16.85±1.65. Generally, the learning styles of students were convergent (% 38.9, assimilative (% 37.5, divergent (%13.2 and accommodative (%10.4. There was a significant relationship between learning styles with gender (P=0.01. Conclusion: Considering the predominance of convergent and assimilative learning styles in these students, it is recommended that faculty members use visual methods such as diagrams, self learning, individualized instruction and emphasize on practical methods in teaching.

  9. Investigation of coronal leakage of root fillings after smear-layer removal with EDTA or Nd:YAG lasing through capillary-flow porometry.

    Science.gov (United States)

    Michiels, Rafaël; Vergauwen, Tom Edgard Maria; Mavridou, Athina; Meire, Maarten; De Bruyne, Mieke; De Moor, Roeland Jozef Gentil

    2010-10-01

    This study investigates the effects of Nd:YAG laser irradiation combined with different irrigation protocols on the marginal seal of root fillings. Limited information exists regarding the effects of morphologic changes to root canal (RC) walls after Nd:YAG laser irradiation after smear-layer removal with EDTA on the sealing ability of root fillings. The 75 root-filled teeth (5 × 15 teeth) were analyzed for through-and-through leakage by using capillary flow porometry (CFP). The RC cleaning procedure determined the assignment to a group: (1) irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP), (2) SP + Nd:YAG lasing (dried RC), (3) NaOCl 2.5% + Nd:YAG lasing (dried RC), (4) SP + Nd:YAG lasing (wet RC), or (5) NaOCl 2.5% + Nd:YAG lasing (wet RC). Groups 1r to 5r consisted of the same filled teeth with resected apices up to the most apical point of the preparation length. Resection was performed after the first CFP measurement. Roots were filled with cold lateral condensation. CFP was used to assess minimum, mean flow and maximum pore diameters after 48 h, and immediately after these measurements, including root resection. Statistics were performed by using nonparametric tests (p > 0.05). An additional three roots per group were submitted to SEM of the RC wall. Through-and-through leakage was observed in all groups. Statistically significant differences were observed in maximum pore diameter: 1r > 3r, and 1r > 5r; in mean flow pore diameter: 1r > 2r, 2r < 4r (p < 0.05). Typical Nd:YAG glazing effects were observed when the smear layer was present and exposed to the laser fiber (i.e., in the groups without use of EDTA) or when the fiber tip made direct contact with a smear-layer free RC wall. The reduction in through-and-through leakage is significantly higher with the Nd:YAG laser as smear-layer modifier than when smear layer is removed with an EDTA rinsing solution.

  10. Oxidation of aqueous EDTA and associated organics and coprecipitation of inorganics by ambient iron-mediated aeration.

    Science.gov (United States)

    Englehardt, James D; Meeroff, Daniel E; Echegoyen, Luis; Deng, Yang; Raymo, Françisco M; Shibata, Tomoyuki

    2007-01-01

    Cationic metal and radionuclide contaminants can be extracted from soils to groundwater with sequestering agents such as EDTA. However, EDTA must then be removed fromthe groundwater, by advanced oxidation or specialized biological treatment. In this work, aqueous individual metal-EDTA solutions were aerated with steel wool for 25 h, at ambient pH, temperature, and pressure. Removal of approximately 99% of EDTA (0.09-1.78 mM); glyoxylic acid (0.153 mM); chelated Cd2+ (0.94 and 0.0952 mM), Pb2+ (0.0502 mM), and Hg2+ (0.0419 mM); and free chromate and vanadate was shown. EDTA was oxidized to glyoxylic acid and formaldehyde, and metals/metalloids were coprecipitated together with iron oxyhydroxide floc. Free arsenite and arsenate were each removed at 99.97%. Free Sr2+, and chelated Ni2+ were removed at 92% and 63%, respectively. Similar removals were obtained from mixtures, including 99.996+/-0.004% removal of total arsenic (95% confidence). Traces of iminodiacetic acid, nitrilotriacetic acid, and ethylenediaminetriacetic acid were detected after 25 h. Results are consistent with first-order, solution-phase oxidation of EDTA and glyoxylic acid by ferryl ion and H202, respectively, with inhibition due to sludge accumulation, and equilibrium metal coprecipitation. This ambient process, to our knowledge previously unknown, agrees with recently reported findings and shows promise for remediation of metals, metalloids, and radionuclides in wastewater, soil, and sediment.

  11. Using electrocoagulation for metal and chelant separation from washing solution after EDTA leaching of Pb, Zn and Cd contaminated soil.

    Science.gov (United States)

    Pociecha, Maja; Lestan, Domen

    2010-02-15

    Electrocoagulation with an Al sacrificial anode was tested for the separation of chelant and heavy metals from a washing solution obtained after leaching Pb (3200 mg kg(-1)), Zn (1100 mg kg(-1)), and Cd (21 mg kg(-1)) contaminated soil with EDTA. In the electrochemical process, the sacrificial anode corroded to release Al(3+) which served as coagulant for precipitation of chelant and metals. A constant current density of 16-128 mAc m(-2) applied between the Al anode and the stainless-steel cathode removed up to 95% Pb, 68% Zn and 66% Cd from the soil washing solution. Approximately half of the initial EDTA remained in the washing solution after treatment, up to 16.3% of the EDTA was adsorbed on Al coagulant and precipitated, the rest of the EDTA was degraded by anodic oxidation. In a separate laboratory-scale remediation experiment, we leached a soil with 40 mmol EDTA per kg of soil and reused the washing solution (after electrocoagulation) in a closed loop. It removed 53% of Pb, 26% of Zn and 52% of Cd from the soil. The discharge solution was clear and colourless, with pH 7.52 and 170 mg L(-1) Pb, 50 mg L(-1) Zn, 1.5 mg L(-1) Cd and 11 mM EDTA.

  12. Oxidative degradation stability and hydrogen sulfide removal performance of dual-ligand iron chelate of Fe-EDTA/CA.

    Science.gov (United States)

    Miao, Xinmei; Ma, Yiwen; Chen, Zezhi; Gong, Huijuan

    2017-09-05

    Catalytic oxidation desulfurization using chelated iron catalyst is an effective method to remove H 2 S from various gas streams including biogas. However, the ligand of ethylenediaminetetraacetic acid (EDTA), which is usually adopted to prepare chelated iron catalyst, is liable to be oxidative degraded, and leads to the loss of desulfurization performance. In order to improve the degradation stability of the iron chelate, a series of iron chelates composed of two ligands including citric acid (CA) and EDTA were prepared and the oxidative degradation stability as well as desulfurization performance of these chelated iron catalysts were studied. Results show that the iron chelate of Fe-CA is more stable than Fe-EDTA, while for the desulfurization performance, the situation is converse. For the dual-ligand iron chelates of Fe-EDTA/CA, with the increase of mol ratio of CA to EDTA in the iron chelate solution, the oxidative degradation stability increased while the desulfurization performance decreased. The results of this work showed that Fe-EDTA/CA with a mol ratio of CA:EDTA = 1:1 presents a relative high oxidative degradation stability and an acceptable desulfurization performance with over 90% of H 2 S removal efficiency.

  13. Reducing the potential for migration of radioactive waste: Aqueous thermal degradation of the chelating agent disodium EDTA

    International Nuclear Information System (INIS)

    Boles, J.S.; Ritchie, K.; Crerar, D.A.

    1987-01-01

    Ethylenediaminetetraacetic acid (EDTA), a common component of cleaning solutions used for decontamination of radioactive equipment, has been associated with increased migration of radionuclides into local groundwaters at some radwaste disposal sites. It has been proposed that predisposal thermal degradation of EDTA-containing aqueous solutions may reduce the potential for chelate-enhanced mobilization of radionuclides at these sites. Aqueous thermal degradation experiments with disodium EDTA have shown that the compound degrades rapidly at 200 0 C with an activation energy of 114.3 +- 7.87 kJ/mol, and forms the decomposition product methyliminodiacetic acid (MIDA). A comparison of the values for stability constants of transition metal and actinide complexes with EDTA, MIDA, and two other reported degradation products, indicates that the chelating efficiency of the degradation products is 6 to 22 orders of magnitude lower than that of EDTA at 25 0 C. It is concluded that aqueous thermal degradation should significantly reduce the overall chelating efficiency of EDTA-containing solutions

  14. Optimizing the molarity of a EDTA washing solution for saturated-soil remediation of trace metal contaminated soils

    International Nuclear Information System (INIS)

    Andrade, M.D.; Prasher, S.O.; Hendershot, W.H.

    2007-01-01

    Three experiments were conducted to optimize the use of ethylenediaminetetraacetic acid (EDTA) for reclaiming urban soils contaminated with trace metals. As compared to Na 2 EDTA (NH 4 ) 2 EDTA extracted 60% more Zn and equivalent amounts of Cd, Cu and Pb from a sandy loam. When successively saturating and draining loamy sand columns during a washing cycle, which submerged it once with a (NH 4 ) 2 EDTA wash and four times with deionised water, the post-wash rinses largely contributed to the total cumulative extraction of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. Both the washing solution and the deionised water rinses were added in a 2:5 liquid to soil (L:S) weight ratio. For equal amounts of EDTA, concentrating the washing solution and applying it and the ensuing rinses in a smaller 1:5 L:S weight ratio, instead of a 2:5 L:S weight ratio, increased the extraction of targeted Cr, Cu, Ni, Pb and Zn. - A single EDTA addition is best utilised in a highly concentrated washing solution given in a small liquid to soil weight ratio

  15. Effect of EDTA and citric acid on phytoremediation of Cr- B[a]P-co-contaminated soil.

    Science.gov (United States)

    Chigbo, Chibuike; Batty, Lesley

    2013-12-01

    Polycyclic aromatic hydrocarbons and heavy metals in the environment are a concern, and their removal to acceptable level is required. Phytoremediation, the use of plants to treat contaminated soils, could be an interesting alternative to conventional remediation processes. This work evaluates the role of single and combined applications of chelates to single or mixed Cr + benzo[a]pyrene (B[a]P)-contaminated soil. Medicago sativa was grown in contaminated soil and was amended with 0.3 g citric acid, 0.146 g ethylenediaminetetraacetic acid (EDTA), or their combination for 60 days. The result shows that in Cr-contaminated soil, the application of EDTA + citric acid significantly (psoil. The soluble Cr concentration in single Cr or Cr + B[a]P-contaminated soil was enhanced with the amendment of all chelates; however, only the application of citric acid in Cr-contaminated soil (44 %) or EDTA and EDTA + citric acid in co-contaminated soil increased the removal of Cr from the soil (34 and 54 %, respectively). The dissipation of B[a]P in single B[a]P-contaminated soil was effective even without planting and amendment with chelates, while in co-contaminated soil, it was related to the application of either EDTA or EDTA + citric acid. This suggests that M. sativa with the help of chelates in single or co-contaminated soil can be effective in phytoextraction of Cr and promoting the biodegradation of B[a]P.

  16. Effect of EDTA washing of metal polluted garden soils. Part I: Toxicity hazards and impact on soil properties.

    Science.gov (United States)

    Jelusic, Masa; Lestan, Domen

    2014-03-15

    We applied a multi-level approach assessing the quality, toxicity and functioning of Pb, Zn and Cd contaminated/remediated soil from a vegetable garden in Meza Valley, Slovenia. Contaminated soil was extracted with EDTA and placed into field experimental plots equipped with lysimeters. Soil properties were assessed by standard pedological analysis. Fractionation and leachability of toxic metals were analyzed by sequential extraction and TCLP and metal bioaccessibility by UBM tests. Soil respiration and enzyme activities were measured as indicators of soil functioning. Remediation reduced the metal burden by 80, 28 and 72% for Pb, Zn and Cd respectively, with a limited impact on soil pedology. Toxic metals associated with labile soil fractions were largely removed. No shifts between labile and residual fractions were observed during the seven months of the experiment. Initial metal leaching measured through lysimeters eventually ceased. However, remediation significantly diminished potential soil enzyme activity and no trends were observed of the remediated soil recovering its biological properties. Soil washing successfully removed available forms of Pb, Zn and Cd and thus lowered the human and environmental hazards of the remediated soil; however, remediation also extracted the trace elements essential for soil biota. In addition to reduced water holding capacity, soil health was not completely restored. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Implementing the Science Assessment Standards: Developing and validating a set of laboratory assessment tasks in high school biology

    Science.gov (United States)

    Saha, Gouranga Chandra

    Very often a number of factors, especially time, space and money, deter many science educators from using inquiry-based, hands-on, laboratory practical tasks as alternative assessment instruments in science. A shortage of valid inquiry-based laboratory tasks for high school biology has been cited. Driven by this need, this study addressed the following three research questions: (1) How can laboratory-based performance tasks be designed and developed that are doable by students for whom they are designed/written? (2) Do student responses to the laboratory-based performance tasks validly represent at least some of the intended process skills that new biology learning goals want students to acquire? (3) Are the laboratory-based performance tasks psychometrically consistent as individual tasks and as a set? To answer these questions, three tasks were used from the six biology tasks initially designed and developed by an iterative process of trial testing. Analyses of data from 224 students showed that performance-based laboratory tasks that are doable by all students require careful and iterative process of development. Although the students demonstrated more skill in performing than planning and reasoning, their performances at the item level were very poor for some items. Possible reasons for the poor performances have been discussed and suggestions on how to remediate the deficiencies have been made. Empirical evidences for validity and reliability of the instrument have been presented both from the classical and the modern validity criteria point of view. Limitations of the study have been identified. Finally implications of the study and directions for further research have been discussed.

  18. 78 FR 27387 - Notice of Workshop and Call for Information on Integrated Science Assessment for Oxides of Sulfur

    Science.gov (United States)

    2013-05-10

    ... periodically, and, if appropriate, to revise existing air quality criteria to reflect advances in scientific... such as chemistry and physics, sources and emissions, analytical methodology, transport and... will update the scientific assessment presented in the Integrated Science Assessment for Sulfur Oxides...

  19. Developing a Construct-Based Assessment to Examine Students' Analogical Reasoning around Physical Models in Earth Science

    Science.gov (United States)

    Rivet, Ann E.; Kastens, Kim A.

    2012-01-01

    In recent years, science education has placed increasing importance on learners' mastery of scientific reasoning. This growing emphasis presents a challenge for both developers and users of assessments. We report on our effort around the conceptualization, development, and testing the validity of an assessment of students' ability to reason around…

  20. Alignment of Assessment Objectives with Instructional Objectives Using Revised Bloom's Taxonomy--The Case for Food Science and Technology Education

    Science.gov (United States)

    Jideani, V. A.; Jideani, I. A.

    2012-01-01

    Nine food science and technology (FST) subjects were assessed for alignment between the learning outcomes and assessment using revised Bloom's taxonomy (RBT) of cognitive knowledge. Conjoint analysis was used to estimate the utilities of the levels of cognitive, knowledge, and the attribute importance (cognitive process and knowledge dimension)…