Sample records for k-12 mg1655 undergoing

  1. SfiI genomic cleavage map of Escherichia coli K-12 strain MG1655.

    PubMed Central

    Perkins, J D; Heath, J D; Sharma, B R; Weinstock, G M

    1992-01-01

    An SfiI restriction map of Escherichia coli K-12 strain MG1655 is presented. The map contains thirty-one cleavage sites separating fragments ranging in size from 407 kb to 3.7 kb. Several techniques were used in the construction of this map, including CHEF pulsed field gel electrophoresis; physical analysis of a set of twenty-six auxotrophic transposon insertions; correlation with the restriction map of Kohara and coworkers using the commercially available E. coli Gene Mapping Membranes; analysis of publicly available sequence information; and correlation of the above data with the combined genetic and physical map developed by Rudd, et al. The combination of these techniques has yielded a map in which all but one site can be localized within a range of +/- 2 kb, and over half the sites can be localized precisely by sequence data. Two sites present in the EcoSeq5 sequence database are not cleaved in MG1655 and four sites are noted to be sensitive to methylation by the dcm methylase. This map, combined with the NotI physical map of MG1655, can aid in the rapid, precise mapping of several different types of genetic alterations, including transposon mediated mutations and other insertions, inversions, deletions and duplications. Images PMID:1312707

  2. Identification of new members of the Escherichia coli K-12 MG1655 SlyA regulon

    PubMed Central

    Curran, Thomas D; Abacha, Fatima; Hibberd, Stephen P; Green, Jeffrey

    2017-01-01

    SlyA is a member of the MarR family of bacterial transcriptional regulators. Previously, SlyA has been shown to directly regulate only two operons in Escherichia coli K-12 MG1655, fimB and hlyE (clyA). In both cases, SlyA activates gene expression by antagonizing repression by the nucleoid-associated protein H-NS. Here, the transcript profiles of aerobic glucose-limited steady-state chemostat cultures of E. coli K-12 MG1655, slyA mutant and slyA over-expression strains are reported. The transcript profile of the slyA mutant was not significantly different from that of the parent; however, that of the slyA expression strain was significantly different from that of the vector control. Transcripts representing 27 operons were increased in abundance, whereas 3 were decreased. Of the 30 differentially regulated operons, 24 have previously been associated with sites of H-NS binding, suggesting that antagonism of H-NS repression is a common feature of SlyA-mediated transcription regulation. Direct binding of SlyA to DNA located upstream of a selection of these targets permitted the identification of new operons likely to be directly regulated by SlyA. Transcripts of four operons coding for cryptic adhesins exhibited enhanced expression, and this was consistent with enhanced biofilm formation associated with the SlyA over-producing strain. PMID:28073397

  3. Identification of new members of the Escherichia coli K-12 MG1655 SlyA regulon.

    PubMed

    Curran, Thomas D; Abacha, Fatima; Hibberd, Stephen P; Rolfe, Matthew D; Lacey, Melissa M; Green, Jeffrey

    2017-03-01

    SlyA is a member of the MarR family of bacterial transcriptional regulators. Previously, SlyA has been shown to directly regulate only two operons in Escherichia coli K-12 MG1655, fimB and hlyE (clyA). In both cases, SlyA activates gene expression by antagonizing repression by the nucleoid-associated protein H-NS. Here, the transcript profiles of aerobic glucose-limited steady-state chemostat cultures of E. coli K-12 MG1655, slyA mutant and slyA over-expression strains are reported. The transcript profile of the slyA mutant was not significantly different from that of the parent; however, that of the slyA expression strain was significantly different from that of the vector control. Transcripts representing 27 operons were increased in abundance, whereas 3 were decreased. Of the 30 differentially regulated operons, 24 have previously been associated with sites of H-NS binding, suggesting that antagonism of H-NS repression is a common feature of SlyA-mediated transcription regulation. Direct binding of SlyA to DNA located upstream of a selection of these targets permitted the identification of new operons likely to be directly regulated by SlyA. Transcripts of four operons coding for cryptic adhesins exhibited enhanced expression, and this was consistent with enhanced biofilm formation associated with the SlyA over-producing strain.

  4. Stock culture heterogeneity rather than new mutational variation complicates short-term cell physiology studies of Escherichia coli K-12 MG1655 in continuous culture.

    PubMed

    Nahku, Ranno; Peebo, Karl; Valgepea, Kaspar; Barrick, Jeffrey E; Adamberg, Kaarel; Vilu, Raivo

    2011-09-01

    Nutrient-limited continuous cultures in chemostats have been used to study microbial cell physiology for over 60 years. Genome instability and genetic heterogeneity are possible uncontrolled factors in continuous cultivation experiments. We investigated these issues by using high-throughput (HT) DNA sequencing to characterize samples from different phases of a glucose-limited accelerostat (A-stat) experiment with Escherichia coli K-12 MG1655 and a duration regularly used in cell physiology studies (20 generations of continuous cultivation). Seven consensus mutations from the reference sequence and five subpopulations characterized by different mutations were detected in the HT-sequenced samples. This genetic heterogeneity was confirmed to result from the stock culture by Sanger sequencing. All the subpopulations in which allele frequencies increased (betA, cspG/cspH, glyA) during the experiment were also present at the end of replicate A-stats, indicating that no new subpopulations emerged during our experiments. The fact that ~31 % of the cells in our initial cultures obtained directly from a culture stock centre were mutants raises concerns that even if cultivations are started from single colonies, there is a significant chance of picking a mutant clone with an altered phenotype. Our results show that current HT DNA sequencing technology allows accurate subpopulation analysis and demonstrates that a glucose-limited E. coli K-12 MG1655 A-stat experiment with a duration of tens of generations is suitable for studying cell physiology and collecting quantitative data for metabolic modelling without interference from new mutations.

  5. Stock culture heterogeneity rather than new mutational variation complicates short-term cell physiology studies of Escherichia coli K-12 MG1655 in continuous culture

    PubMed Central

    Nahku, Ranno; Peebo, Karl; Valgepea, Kaspar; Barrick, Jeffrey E.; Adamberg, Kaarel

    2011-01-01

    Nutrient-limited continuous cultures in chemostats have been used to study microbial cell physiology for over 60 years. Genome instability and genetic heterogeneity are possible uncontrolled factors in continuous cultivation experiments. We investigated these issues by using high-throughput (HT) DNA sequencing to characterize samples from different phases of a glucose-limited accelerostat (A-stat) experiment with Escherichia coli K-12 MG1655 and a duration regularly used in cell physiology studies (20 generations of continuous cultivation). Seven consensus mutations from the reference sequence and five subpopulations characterized by different mutations were detected in the HT-sequenced samples. This genetic heterogeneity was confirmed to result from the stock culture by Sanger sequencing. All the subpopulations in which allele frequencies increased (betA, cspG/cspH, glyA) during the experiment were also present at the end of replicate A-stats, indicating that no new subpopulations emerged during our experiments. The fact that ~31 % of the cells in our initial cultures obtained directly from a culture stock centre were mutants raises concerns that even if cultivations are started from single colonies, there is a significant chance of picking a mutant clone with an altered phenotype. Our results show that current HT DNA sequencing technology allows accurate subpopulation analysis and demonstrates that a glucose-limited E. coli K-12 MG1655 A-stat experiment with a duration of tens of generations is suitable for studying cell physiology and collecting quantitative data for metabolic modelling without interference from new mutations. PMID:21700661

  6. Genome-wide Reconstruction of OxyR and SoxRS Transcriptional Regulatory Networks under Oxidative Stress in Escherichia coli K-12 MG1655.

    PubMed

    Seo, Sang Woo; Kim, Donghyuk; Szubin, Richard; Palsson, Bernhard O

    2015-08-25

    Three transcription factors (TFs), OxyR, SoxR, and SoxS, play a critical role in transcriptional regulation of the defense system for oxidative stress in bacteria. However, their full genome-wide regulatory potential is unknown. Here, we perform a genome-scale reconstruction of the OxyR, SoxR, and SoxS regulons in Escherichia coli K-12 MG1655. Integrative data analysis reveals that a total of 68 genes in 51 transcription units (TUs) belong to these regulons. Among them, 48 genes showed more than 2-fold changes in expression level under single-TF-knockout conditions. This reconstruction expands the genome-wide roles of these factors to include direct activation of genes related to amino acid biosynthesis (methionine and aromatic amino acids), cell wall synthesis (lipid A biosynthesis and peptidoglycan growth), and divalent metal ion transport (Mn(2+), Zn(2+), and Mg(2+)). Investigating the co-regulation of these genes with other stress-response TFs reveals that they are independently regulated by stress-specific TFs. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  7. 5 CFR 1655.12 - Loan agreement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Loan agreement. 1655.12 Section 1655.12 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.12 Loan agreement. (a... participant submits a paper loan application, the TSP record keeper will mail the loan agreement, and other...

  8. 5 CFR 1655.12 - Loan agreement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Loan agreement. 1655.12 Section 1655.12 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.12 Loan agreement. (a... participant submits a paper loan application, the TSP record keeper will mail the loan agreement, and other...

  9. 5 CFR 1655.12 - Loan agreement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Loan agreement. 1655.12 Section 1655.12 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.12 Loan agreement. (a... participant submits a paper loan application, the TSP record keeper will mail the loan agreement, and other...

  10. Revealing genome-scale transcriptional regulatory landscape of OmpR highlights its expanded regulatory roles under osmotic stress in Escherichia coli K-12 MG1655.

    PubMed

    Seo, Sang Woo; Gao, Ye; Kim, Donghyuk; Szubin, Richard; Yang, Jina; Cho, Byung-Kwan; Palsson, Bernhard O

    2017-05-19

    A transcription factor (TF), OmpR, plays a critical role in transcriptional regulation of the osmotic stress response in bacteria. Here, we reveal a genome-scale OmpR regulon in Escherichia coli K-12 MG1655. Integrative data analysis reveals that a total of 37 genes in 24 transcription units (TUs) belong to OmpR regulon. Among them, 26 genes show more than two-fold changes in expression level in an OmpR knock-out strain. Specifically, we find that: 1) OmpR regulates mostly membrane-located gene products involved in diverse fundamental biological processes, such as narU (encoding nitrate/nitrite transporter), ompX (encoding outer membrane protein X), and nuoN (encoding NADH:ubiquinone oxidoreductase); 2) by investigating co-regulation of entire sets of genes regulated by other stress-response TFs, stresses are surprisingly independently regulated among each other; and, 3) a detailed investigation of the physiological roles of the newly discovered OmpR regulon genes reveals that activation of narU represents a novel strategy to significantly improve osmotic stress tolerance of E. coli. Thus, the genome-scale approach to elucidating regulons comprehensively identifies regulated genes and leads to fundamental discoveries related to stress responses.

  11. [Construction of the new Escherichia coli K-12 wild-type strain with improved growth characteristics for application in metabolic engineering].

    PubMed

    Biriukova, I V; Krylov, A A; Kiseleva, E M; Minaeva, N I; Mashko, S V

    2010-03-01

    MG1655 of Escherichia coli K-12 is frequently used in metabolic engineering as the wild-type strain. However, its two mutations, ilvG and rph-1 provide a negative effect on culture growth. The "polar effect" of rph-1 decreases the level of pyrE expression, causing partial auxotrophy for pyrimidines. Mutation ilvG leading to the appearance of Val(S) phenotype causes retardation of cell growth rate on media containing amino acids. In this work, the substitution of two loci in the genome of MG1655 with the recovery of the wild-type phenotype was accomplished. Gene rph(wt) from the chromosome of E. coli TG1 was marked via Red-dependent integration of DNA fragment carrying lambda attL-Cm(R)-lambda attR and transduced with phage P1 into MG1655; later, the Cm(R) marker was removed with the use of lambda Xis/Int recombinase. Parallel to this procedure, a spontaneous Val(R) mutant of E. coli MG1655 yielding colonies of maximal size on M9 medium with glucose in the presence of Val (50 microg/ml) was isolated. It was shown that a nucleotide deletion in the isolated Val(R) strain had been generated in the region of the identified E. coli K-12 ilvG mutation, which led to the recovery of the reading frame and active protein synthesis. This mutation named ilvG-15, which is the only reason for the Val(R) phenotype in the obtained strain, was transferred to MG1655-rph(wt) using cotransduction, by analogy to the transfer of rph(wt). Evaluation of rates of aerobically growing cells (microm, hour(-1)) on M9 medium with glucose produced the following values: 0.56, 0.69, and 0.73 for strains MG1655, MG1655-rph(wt), and MG1655-(rph(wt), ilvG-15), respectively.

  12. Construction of 2,4,6-Trinitrotoluene Biosensors with Novel Sensing Elements from Escherichia coli K-12 MG1655.

    PubMed

    Tan, Junjie; Kan, Naipeng; Wang, Wei; Ling, Jingyi; Qu, Guolong; Jin, Jing; Shao, Yu; Liu, Gang; Chen, Huipeng

    2015-06-01

    Detection of 2,4,6-trinitrotoluene (TNT) has been extensively studied since it is a common explosive filling for landmines, posing significant threats to the environment and human safety. The rapid advances in synthetic biology give new hope to detect such toxic and hazardous compounds in a more sensitive and safe way. Biosensor construction anticipates finding sensing elements able to detect TNT. As TNT can induce some physiological responses in E. coli, it may be useful to define the sensing elements from E. coli to detect TNT. An E. coli MG1655 genomic promoter library containing nearly 5,400 elements was constructed. Five elements, yadG, yqgC, aspC, recE, and topA, displayed high sensing specificity to TNT and its indicator compounds 1,3-DNB and 2,4-DNT. Based on this, a whole cell biosensor was constructed using E. coli, in which green fluorescent protein was positioned downstream of the five sensing elements via genetic fusion. The threshold value, detection time, EC200 value, and other aspects of five sensing elements were determined and the minimum responding concentration to TNT was 4.75 mg/L. According to the synthetic biology, the five sensing elements enriched the reservoir of TNT-sensing elements, and provided a more applicable toolkit to be applied in genetic routes and live systems of biosensors in future.

  13. Whole-genome resequencing of Escherichia coli K-12 MG1655 undergoing short-term laboratory evolution in lactate minimal media reveals flexible selection of adaptive mutations

    PubMed Central

    2009-01-01

    Background Short-term laboratory evolution of bacteria followed by genomic sequencing provides insight into the mechanism of adaptive evolution, such as the number of mutations needed for adaptation, genotype-phenotype relationships, and the reproducibility of adaptive outcomes. Results In the present study, we describe the genome sequencing of 11 endpoints of Escherichia coli that underwent 60-day laboratory adaptive evolution under growth rate selection pressure in lactate minimal media. Two to eight mutations were identified per endpoint. Generally, each endpoint acquired mutations to different genes. The most notable exception was an 82 base-pair deletion in the rph-pyrE operon that appeared in 7 of the 11 adapted strains. This mutation conferred an approximately 15% increase to the growth rate when experimentally introduced to the wild-type background and resulted in an approximately 30% increase to growth rate when introduced to a background already harboring two adaptive mutations. Additionally, most endpoints had a mutation in a regulatory gene (crp or relA, for example) or the RNA polymerase. Conclusions The 82 base-pair deletion found in the rph-pyrE operon of many endpoints may function to relieve a pyrimidine biosynthesis defect present in MG1655. In contrast, a variety of regulators acquire mutations in the different endpoints, suggesting flexibility in overcoming regulatory challenges in the adaptation. PMID:19849850

  14. Use of Adaptive Laboratory Evolution To Discover Key Mutations Enabling Rapid Growth of Escherichia coli K-12 MG1655 on Glucose Minimal Medium

    PubMed Central

    LaCroix, Ryan A.; Sandberg, Troy E.; O'Brien, Edward J.; Utrilla, Jose; Ebrahim, Ali; Guzman, Gabriela I.; Szubin, Richard; Palsson, Bernhard O.

    2014-01-01

    Adaptive laboratory evolution (ALE) has emerged as an effective tool for scientific discovery and addressing biotechnological needs. Much of ALE's utility is derived from reproducibly obtained fitness increases. Identifying causal genetic changes and their combinatorial effects is challenging and time-consuming. Understanding how these genetic changes enable increased fitness can be difficult. A series of approaches that address these challenges was developed and demonstrated using Escherichia coli K-12 MG1655 on glucose minimal media at 37°C. By keeping E. coli in constant substrate excess and exponential growth, fitness increases up to 1.6-fold were obtained compared to the wild type. These increases are comparable to previously reported maximum growth rates in similar conditions but were obtained over a shorter time frame. Across the eight replicate ALE experiments performed, causal mutations were identified using three approaches: identifying mutations in the same gene/region across replicate experiments, sequencing strains before and after computationally determined fitness jumps, and allelic replacement coupled with targeted ALE of reconstructed strains. Three genetic regions were most often mutated: the global transcription gene rpoB, an 82-bp deletion between the metabolic pyrE gene and rph, and an IS element between the DNA structural gene hns and tdk. Model-derived classification of gene expression revealed a number of processes important for increased growth that were missed using a gene classification system alone. The methods described here represent a powerful combination of technologies to increase the speed and efficiency of ALE studies. The identified mutations can be examined as genetic parts for increasing growth rate in a desired strain and for understanding rapid growth phenotypes. PMID:25304508

  15. Use of adaptive laboratory evolution to discover key mutations enabling rapid growth of Escherichia coli K-12 MG1655 on glucose minimal medium.

    PubMed

    LaCroix, Ryan A; Sandberg, Troy E; O'Brien, Edward J; Utrilla, Jose; Ebrahim, Ali; Guzman, Gabriela I; Szubin, Richard; Palsson, Bernhard O; Feist, Adam M

    2015-01-01

    Adaptive laboratory evolution (ALE) has emerged as an effective tool for scientific discovery and addressing biotechnological needs. Much of ALE's utility is derived from reproducibly obtained fitness increases. Identifying causal genetic changes and their combinatorial effects is challenging and time-consuming. Understanding how these genetic changes enable increased fitness can be difficult. A series of approaches that address these challenges was developed and demonstrated using Escherichia coli K-12 MG1655 on glucose minimal media at 37°C. By keeping E. coli in constant substrate excess and exponential growth, fitness increases up to 1.6-fold were obtained compared to the wild type. These increases are comparable to previously reported maximum growth rates in similar conditions but were obtained over a shorter time frame. Across the eight replicate ALE experiments performed, causal mutations were identified using three approaches: identifying mutations in the same gene/region across replicate experiments, sequencing strains before and after computationally determined fitness jumps, and allelic replacement coupled with targeted ALE of reconstructed strains. Three genetic regions were most often mutated: the global transcription gene rpoB, an 82-bp deletion between the metabolic pyrE gene and rph, and an IS element between the DNA structural gene hns and tdk. Model-derived classification of gene expression revealed a number of processes important for increased growth that were missed using a gene classification system alone. The methods described here represent a powerful combination of technologies to increase the speed and efficiency of ALE studies. The identified mutations can be examined as genetic parts for increasing growth rate in a desired strain and for understanding rapid growth phenotypes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Comparative analysis of envelope proteomes in Escherichia coli B and K-12 strains.

    PubMed

    Han, Mee-Jung; Lee, Sang Yup; Hong, Soon Ho

    2012-04-01

    Recent genome comparisons of E. coli B and K-12 strains have indicated that the makeup of the cell envelopes in these two strains is quite different. Therefore, we analyzed and compared the envelope proteomes of E. coli BL21(DE3) and MG1655. A total of 165 protein spots, including 62 nonredundant proteins, were unambiguously identified by two-dimensional gel electrophoresis and mass spectrometry. Of these, 43 proteins were conserved between the two strains, whereas 4 and 16 strain-specific proteins were identified only in E. coli BL21(DE3) and MG1655, respectively. Additionally, 24 proteins showed more than 2-fold differences in intensities between the B and K-12 strains. The reference envelope proteome maps showed that E. coli envelope mainly contained channel proteins and lipoproteins. Interesting proteomic observations between the two strains were as follows: (i) B produced more OmpF porin with a larger pore size than K-12, indicating an increase in the membrane permeability; (ii) B produced higher amounts of lipoproteins, which facilitates the assembly of outer membrane beta-barrel proteins; and (iii) motility- (FliC) and chemotaxis-related proteins (CheA and CheW) were detected only in K-12, which showed that E. coli B is restricted with regard to migration under unfavorable conditions. These differences may influence the permeability and integrity of the cell envelope, showing that E. coli B may be more susceptible than K-12 to certain stress conditions. Thus, these findings suggest that E. coli K-12 and its derivatives will be more favorable strains in certain biotechnological applications, such as cell surface display or membrane engineering studies.

  17. An individual-based modeling approach to simulate the effects of cellular nutrient competition on Escherichia coli K-12 MG1655 colony behavior and interactions in aerobic structured food systems.

    PubMed

    Tack, Ignace L M M; Logist, Filip; Noriega Fernández, Estefanía; Van Impe, Jan F M

    2015-02-01

    Traditional kinetic models in predictive microbiology reliably predict macroscopic dynamics of planktonically-growing cell cultures in homogeneous liquid food systems. However, most food products have a semi-solid structure, where microorganisms grow locally in colonies. Individual colony cells exhibit strongly different and non-normally distributed behavior due to local nutrient competition. As a result, traditional models considering average population behavior in a homogeneous system do not describe colony dynamics in full detail. To incorporate local resource competition and individual cell differences, an individual-based modeling approach has been applied to Escherichia coli K-12 MG1655 colonies, considering the microbial cell as modeling unit. The first contribution of this individual-based model is to describe single colony growth under nutrient-deprived conditions. More specifically, the linear and stationary phase in the evolution of the colony radius, the evolution from a disk-like to branching morphology, and the emergence of a starvation zone in the colony center are simulated and compared to available experimental data. These phenomena occur earlier at more severe nutrient depletion conditions, i.e., at lower nutrient diffusivity and initial nutrient concentration in the medium. Furthermore, intercolony interactions have been simulated. Higher inoculum densities lead to stronger intercolony interactions, such as colony merging and smaller colony sizes, due to nutrient competition. This individual-based model contributes to the elucidation of characteristic experimentally observed colony behavior from mechanistic information about cellular physiology and interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA SgrS.

    PubMed

    Negrete, Alejandro; Majdalani, Nadim; Phue, Je-Nie; Shiloach, Joseph

    2013-01-25

    When exposed to the nonmetabolized glucose derivative alpha methyl glucoside (αMG), both Escherichia coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICB(glu). This occurs through the over-expression of the noncoding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a glucose concentration of 40 g/L, over-expression of SgrS is observed only in E. coli B (BL21). Unlike E. coli K-12 (JM109 and MG1655), which are affected by high glucose concentration and produce higher levels of acetate, E. coli B (BL21) is not affected. Based on this information, it was assumed that over-expression of SgrS enables E. coli B (BL21) to reduce its acetate excretion by controlling the glucose transport. When SgrS was over-expressed in both E. coli K-12 strains from a multicopy plasmid, it was possible to reduce their acetate excretion levels to those seen in E. coli B. This observation opens a new approach towards controlling bacterial metabolism through the use of noncoding RNA. Published by Elsevier B.V.

  19. Differential high pressure survival in stationary-phase Escherichia coli MG1655

    NASA Astrophysics Data System (ADS)

    Griffin, Patrick L.; Kish, Adrienne; Steele, Andrew; Hemley, Russell J.

    2011-06-01

    Hydrostatic pressure exerts a profound influence on nearly all facets of cellular structure and function with exposures to sufficiently high pressure leading to microbial inactivation. We report the first observation of a persistent, pressure-resistant subpopulation within stationary-phase samples of Escherichia coli MG1655, a mesophilic bacterium adapted to surface pressure. This high pressure-resistant subpopulation exhibits pressure survival ranging from 0.6 to 2.0 orders of magnitude greater survival than high pressure treatments at pressures of 225-400 MPa. We also examine some aspects of pressure treatment protocol that may influence the measurements of high pressure survival.

  20. Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA sgrS

    PubMed Central

    Negrete, Alejandro; Majdalani, Nadim; Phue, Je Nie; Shiloach, Joseph

    2011-01-01

    When exposed to the non-metabolized glucose derivative alpha methyl glucoside, both E. coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICBglu. This occurs through the over-expression of the non-coding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a glucose concentration of 40 g/L, over-expression of SgrS is observed only in E. coli B (BL21). Unlike E. coli K-12 (JM109 and MG1655), which are affected by high glucose concentration and produce higher levels of acetate, E. coli B (BL21) is not affected. Based on this information, it was assumed that over-expression of SgrS enables E. coli B (BL21) to reduce its acetate excretion by controlling the glucose transport. When SgrS was over-expressed in both E. coli K-12 strains from a multicopy plasmid, it was possible to reduce their acetate excretion levels to those seen in E. coli B. This observation opens a new approach towards controlling bacterial metabolism through the use of non-coding RNA. PMID:22107968

  1. Quantitative protein expression and cell surface characteristics of Escherichia coli MG1655 biofilms.

    PubMed

    Mukherjee, Joy; Ow, Saw Yen; Noirel, Josselin; Biggs, Catherine A

    2011-02-01

    Cell surface physicochemical characterization techniques were combined with quantitative changes in protein expression, to investigate the biological and biophysical changes of Escherichia coli MG1655 cells when grown as a biofilm (BIO). The overall surface charge of BIO cells was found to be less negative, highlighting the need for a lower electrophoretic mobility for attachment to occur. Comparison of the chemical functional groups on the cell surface showed similar profiles, with the absorbance intensity higher for proteins and carbohydrates in the BIO cells. Quantitative proteomic analysis demonstrated that 3 proteins were significantly increased, and 9 proteins significantly decreased in abundance, in cells grown as a BIO compared to their planktonic counterparts, with 7 of these total 12 proteins unique to this study. Proteins showing significant increased or decreased abundance include proteins involved in acid resistance, DNA protection and binding and ABC transporters. Further predictive analysis of the metabolic pathways showed an increased abundance of the amino acid metabolism and tricarboxylic acid (TCA) cycle, with a decrease in expression within the pentose phosphate and glycolysis pathways. It is therefore hypothesized that cells grown as a BIO are still energetically viable potentially using amino acids as an indirect carbon backbone source into the TCA cycle. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Engineering Escherichia coli K12 MG1655 to use starch

    PubMed Central

    2014-01-01

    Background To attain a sustainable bioeconomy, fuel, or valuable product, production must use biomass as substrate. Starch is one of the most abundant biomass resources and is present as waste or as a food and agroindustry by-product. Unfortunately, Escherichia coli, one of the most widely used microorganisms in biotechnological processes, cannot use starch as a carbon source. Results We engineered an E. coli strain capable of using starch as a substrate. The genetic design employed the native capability of the bacterium to use maltodextrins as a carbon source plus expression and secretion of its endogenous α-amylase, AmyA, in an adapted background. Biomass production improved using 35% dissolved oxygen and pH 7.2 in a controlled bioreactor. Conclusion The engineered E. coli strain can use starch from the milieu and open the possibility of optimize the process to use agroindustrial wastes to produce biofuels and other valuable chemicals. PMID:24886307

  3. 5 CFR 1655.14 - Loan payments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Loan payments. 1655.14 Section 1655.14 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.14 Loan payments. (a) Loan payments must be made through payroll deduction in accordance with the loan agreement. Once loan...

  4. 5 CFR 1655.7 - Interest rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Interest rate. 1655.7 Section 1655.7 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.7 Interest rate. (a... interest rate established by the Department of the Treasury in effect on the date the TSP record keeper...

  5. 5 CFR 1655.11 - Loan acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Loan acceptance. 1655.11 Section 1655.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.11 Loan acceptance. The TSP record keeper will reject a loan application if: (a) The participant is not qualified to apply for...

  6. 5 CFR 1655.18 - Spousal rights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Spousal rights. 1655.18 Section 1655.18 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.18 Spousal rights. (a) Spouse of CSRS participant. (1) Before a loan is disbursed to a CSRS participant, the TSP record keeper...

  7. 5 CFR 1655.7 - Interest rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Interest rate. 1655.7 Section 1655.7 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.7 Interest rate. (a... interest rate established by the Department of the Treasury in effect on the date the TSP record keeper...

  8. 5 CFR 1655.7 - Interest rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Interest rate. 1655.7 Section 1655.7 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.7 Interest rate. (a... interest rate established by the Department of the Treasury in effect on the date the TSP record keeper...

  9. 5 CFR 1655.7 - Interest rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Interest rate. 1655.7 Section 1655.7 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.7 Interest rate. (a... interest rate established by the Department of the Treasury in effect on the date the TSP record keeper...

  10. 5 CFR 1655.21 - Loan fee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Loan fee. 1655.21 Section 1655.21 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.21 Loan fee. The TSP will charge a participant a $50.00 loan fee when it disburses the loan and will deduct the fee from the...

  11. Development of an Escherichia coli K12-specific quantitative polymerase chain reaction assay and DNA isolation suited to biofilms associated with iron drinking water pipe corrosion products.

    PubMed

    Lu, Jingrang; Gerke, Tammie L; Buse, Helen Y; Ashbolt, Nicholas J

    2014-12-01

    A quantitative polymerase chain reaction assay (115 bp amplicon) specific to Escherichia coli K12 with an ABI(TM) internal control was developed based on sequence data encoding the rfb gene cluster. Assay specificity was evaluated using three E. coli K12 strains (ATCC W3110, MG1655 & DH1), 24 non-K12 E. coli and 23 bacterial genera. The biofilm detection limit was 10(3) colony-forming units (CFU) E. coli K12 mL(-1), but required a modified protocol, which included a bio-blocker Pseudomonas aeruginosa with ethylenediaminetetraacetic acid buffered to pH 5 prior to cell lysis/DNA extraction. The novel protocol yielded the same sensitivity for drinking water biofilms associated with Fe3O4 (magnetite)-coated SiO2 (quartz) grains and biofilm-surface iron corrosion products from a drinking water distribution system. The novel DNA extraction protocol and specific E. coli K12 assay are sensitive and robust enough for detection and quantification within iron drinking water pipe biofilms, and are particularly well suited for studying enteric bacterial interactions within biofilms.

  12. Complete Genome Sequence of ER2796, a DNA Methyltransferase-Deficient Strain of Escherichia coli K-12.

    PubMed

    Anton, Brian P; Mongodin, Emmanuel F; Agrawal, Sonia; Fomenkov, Alexey; Byrd, Devon R; Roberts, Richard J; Raleigh, Elisabeth A

    2015-01-01

    We report the complete sequence of ER2796, a laboratory strain of Escherichia coli K-12 that is completely defective in DNA methylation. Because of its lack of any native methylation, it is extremely useful as a host into which heterologous DNA methyltransferase genes can be cloned and the recognition sequences of their products deduced by Pacific Biosciences Single-Molecule Real Time (SMRT) sequencing. The genome was itself sequenced from a long-insert library using the SMRT platform, resulting in a single closed contig devoid of methylated bases. Comparison with K-12 MG1655, the first E. coli K-12 strain to be sequenced, shows an essentially co-linear relationship with no major rearrangements despite many generations of laboratory manipulation. The comparison revealed a total of 41 insertions and deletions, and 228 single base pair substitutions. In addition, the long-read approach facilitated the surprising discovery of four gene conversion events, three involving rRNA operons and one between two cryptic prophages. Such events thus contribute both to genomic homogenization and to bacteriophage diversification. As one of relatively few laboratory strains of E. coli to be sequenced, the genome also reveals the sequence changes underlying a number of classical mutant alleles including those affecting the various native DNA methylation systems.

  13. Complete Genome Sequence of ER2796, a DNA Methyltransferase-Deficient Strain of Escherichia coli K-12

    PubMed Central

    Anton, Brian P.; Mongodin, Emmanuel F.; Agrawal, Sonia; Fomenkov, Alexey; Byrd, Devon R.; Roberts, Richard J.; Raleigh, Elisabeth A.

    2015-01-01

    We report the complete sequence of ER2796, a laboratory strain of Escherichia coli K-12 that is completely defective in DNA methylation. Because of its lack of any native methylation, it is extremely useful as a host into which heterologous DNA methyltransferase genes can be cloned and the recognition sequences of their products deduced by Pacific Biosciences Single-Molecule Real Time (SMRT) sequencing. The genome was itself sequenced from a long-insert library using the SMRT platform, resulting in a single closed contig devoid of methylated bases. Comparison with K-12 MG1655, the first E. coli K-12 strain to be sequenced, shows an essentially co-linear relationship with no major rearrangements despite many generations of laboratory manipulation. The comparison revealed a total of 41 insertions and deletions, and 228 single base pair substitutions. In addition, the long-read approach facilitated the surprising discovery of four gene conversion events, three involving rRNA operons and one between two cryptic prophages. Such events thus contribute both to genomic homogenization and to bacteriophage diversification. As one of relatively few laboratory strains of E. coli to be sequenced, the genome also reveals the sequence changes underlying a number of classical mutant alleles including those affecting the various native DNA methylation systems. PMID:26010885

  14. 21 CFR 184.1655 - Propane.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propane. 184.1655 Section 184.1655 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific...

  15. 5 CFR 1655.4 - Number of loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Number of loans. 1655.4 Section 1655.4 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD LOAN PROGRAM § 1655.4 Number of loans. A participant may have no more than two loans outstanding from his or her TSP account at any time. One of the...

  16. 28 CFR 16.55 - Other rights and services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Other rights and services. 16.55 Section 16.55 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE OF MATERIAL OR INFORMATION Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 16.55 Other...

  17. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  18. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  19. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  20. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  1. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  2. K{sub 2}Mg{sub 5-x}Sn{sub 3} and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, pb) with two types of Mg-Sn/Pb frameworks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lei, Xiao-Wu, E-mail: xwlei10@163.co

    2011-04-15

    K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) have been synthesized by reacting the mixture of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction studies. K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) is isostructural with Ni{sub 7-x}SbQ{sub 2} (Q=Se, Te) series and features 2D corrugated [Mg{sub 5-x}Sn{sub 3}] layers that are separated by K{sup +} cations. The structure of K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) is closely related to the Ho{sub 2}Rh{sub 12}As{sub 7} structural type and features 3D [Mg{sub 18}Tt{sub 11}] framework composed of 1D [Mg{sub 18}Tt{sub 11}] columns that aremore » interconnected via Mg-Tt bonds, forming 1D hexagonal tunnels occupied by the K+ cations. Electronic structure calculations indicate that Mg atoms can function as either electron donor or as a participator in the network along with Tt atoms. Magnetic property measurements and band structure calculations indicate that these compounds are metallic. -- Graphical abstract: Two new K-Mg-Tt phases, K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb), have been synthesized and structurally characterized. K{sub 2}Mg{sub 5-x}Sn{sub 3} is isostructural with Ni{sub 7-x}SbQ{sub 2} (Q=Se, Te) and features a 2D corrugated [Mg{sub 5}Sn{sub 3}] layer that is separated by K{sup +} cations, and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) is closely related to the Ho{sub 2}Rh{sub 12}As{sub 7} structure type and features a 3D [Mg{sub 18}Tt{sub 11}] network with 1D hexagonal tunnels along the c-axis occupied by K{sup +} cations. Display Omitted Research highlights: Two new polar intermetallics, K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb). Electronic structure calculations were performed by both TB-LMTO and EHTB methods. Mg atom can function as either electron donor or participator in the network.« less

  3. 21 CFR 862.1655 - Pyruvic acid test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... treatment of acid-base and electrolyte disturbances or anoxia (the reduction of oxygen in body tissues). (b... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pyruvic acid test system. 862.1655 Section 862....1655 Pyruvic acid test system. (a) Identification. A pyruvic acid test system is a device intended to...

  4. 21 CFR 862.1655 - Pyruvic acid test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... treatment of acid-base and electrolyte disturbances or anoxia (the reduction of oxygen in body tissues). (b... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pyruvic acid test system. 862.1655 Section 862....1655 Pyruvic acid test system. (a) Identification. A pyruvic acid test system is a device intended to...

  5. 21 CFR 862.1655 - Pyruvic acid test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... treatment of acid-base and electrolyte disturbances or anoxia (the reduction of oxygen in body tissues). (b... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pyruvic acid test system. 862.1655 Section 862....1655 Pyruvic acid test system. (a) Identification. A pyruvic acid test system is a device intended to...

  6. 21 CFR 862.1655 - Pyruvic acid test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... treatment of acid-base and electrolyte disturbances or anoxia (the reduction of oxygen in body tissues). (b... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pyruvic acid test system. 862.1655 Section 862....1655 Pyruvic acid test system. (a) Identification. A pyruvic acid test system is a device intended to...

  7. 21 CFR 862.1655 - Pyruvic acid test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... treatment of acid-base and electrolyte disturbances or anoxia (the reduction of oxygen in body tissues). (b... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pyruvic acid test system. 862.1655 Section 862....1655 Pyruvic acid test system. (a) Identification. A pyruvic acid test system is a device intended to...

  8. Stabilization mechanism of γ-Mg17Al12 and β-Mg2Al3 complex metallic alloys

    NASA Astrophysics Data System (ADS)

    Vrtnik, S.; Jazbec, S.; Jagodič, M.; Korelec, A.; Hosnar, L.; Jagličić, Z.; Jeglič, P.; Feuerbacher, M.; Mizutani, U.; Dolinšek, J.

    2013-10-01

    Large-unit-cell complex metallic alloys (CMAs) frequently achieve stability by lowering the kinetic energy of the electron system through formation of a pseudogap in the electronic density of states (DOS) across the Fermi energy ɛF. By employing experimental techniques that are sensitive to the electronic DOS in the vicinity of ɛF, we have studied the stabilization mechanism of two binary CMA phases from the Al-Mg system: the γ-Mg17Al12 phase with 58 atoms in the unit cell and the β-Mg2Al3 phase with 1178 atoms in the unit cell. Since the investigated alloys are free from transition metal elements, orbital hybridization effects must be small and we were able to test whether the alloys obey the Hume-Rothery stabilization mechanism, where a pseudogap in the DOS is produced by the Fermi surface-Brillouin zone interactions. The results have shown that the DOS of the γ-Mg17Al12 phase exhibits a pronounced pseudogap centered almost exactly at ɛF, which is compatible with the theoretical prediction that this phase is stabilized by the Hume-Rothery mechanism. The disordered cubic β-Mg2Al3 phase is most likely entropically stabilized at high temperatures, whereas at lower temperatures stability is achieved by undergoing a structural phase transition to more ordered rhombohedral β‧ phase at 214 ° C, where all atomic sites become fully occupied. No pseudogap in the vicinity of ɛF was detected for the β‧ phase on the energy scale of a few 100 meV as determined by the ‘thermal observation window’ of the Fermi-Dirac function, so that the Hume-Rothery stabilization mechanism is not confirmed for this compound. However, the existence of a much broader shallow pseudogap due to several critical reciprocal lattice vectors \\buildrel{\\rightharpoonup}\\over{G} that simultaneously satisfy the Hume-Rothery interference condition remains the most plausible stabilization mechanism of this phase. At Tc = 0.85 K, the β‧ phase undergoes a superconducting transition

  9. Laboratory adapted Escherichia coli K-12 becomes a pathogen of Caenorhabditis elegans upon restoration of O antigen biosynthesis.

    PubMed

    Browning, Douglas F; Wells, Timothy J; França, Fernanda L S; Morris, Faye C; Sevastsyanovich, Yanina R; Bryant, Jack A; Johnson, Matthew D; Lund, Peter A; Cunningham, Adam F; Hobman, Jon L; May, Robin C; Webber, Mark A; Henderson, Ian R

    2013-03-01

    Escherichia coli has been the leading model organism for many decades. It is a fundamental player in modern biology, facilitating the molecular biology revolution of the last century. The acceptance of E. coli as model organism is predicated primarily on the study of one E. coli lineage; E. coli K-12. However, the antecedents of today's laboratory strains have undergone extensive mutagenesis to create genetically tractable offspring but which resulted in loss of several genetic traits such as O antigen expression. Here we have repaired the wbbL locus, restoring the ability of E. coli K-12 strain MG1655 to express the O antigen. We demonstrate that O antigen production results in drastic alterations of many phenotypes and the density of the O antigen is critical for the observed phenotypes. Importantly, O antigen production enables laboratory strains of E. coli to enter the gut of the Caenorhabditis elegans worm and to kill C. elegans at rates similar to pathogenic bacterial species. We demonstrate C. elegans killing is a feature of other commensal E. coli. We show killing is associated with bacterial resistance to mechanical shear and persistence in the C. elegans gut. These results suggest C. elegans is not an effective model of human-pathogenic E. coli infectious disease. © 2013 Blackwell Publishing Ltd.

  10. Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12.

    PubMed

    Hayashi, T; Makino, K; Ohnishi, M; Kurokawa, K; Ishii, K; Yokoyama, K; Han, C G; Ohtsubo, E; Nakayama, K; Murata, T; Tanaka, M; Tobe, T; Iida, T; Takami, H; Honda, T; Sasakawa, C; Ogasawara, N; Yasunaga, T; Kuhara, S; Shiba, T; Hattori, M; Shinagawa, H

    2001-02-28

    Escherichia coli O157:H7 is a major food-borne infectious pathogen that causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Here we report the complete chromosome sequence of an O157:H7 strain isolated from the Sakai outbreak, and the results of genomic comparison with a benign laboratory strain, K-12 MG1655. The chromosome is 5.5 Mb in size, 859 Kb larger than that of K-12. We identified a 4.1-Mb sequence highly conserved between the two strains, which may represent the fundamental backbone of the E. coli chromosome. The remaining 1.4-Mb sequence comprises of O157:H7-specific sequences, most of which are horizontally transferred foreign DNAs. The predominant roles of bacteriophages in the emergence of O157:H7 is evident by the presence of 24 prophages and prophage-like elements that occupy more than half of the O157:H7-specific sequences. The O157:H7 chromosome encodes 1632 proteins and 20 tRNAs that are not present in K-12. Among these, at least 131 proteins are assumed to have virulence-related functions. Genome-wide codon usage analysis suggested that the O157:H7-specific tRNAs are involved in the efficient expression of the strain-specific genes. A complete set of the genes specific to O157:H7 presented here sheds new insight into the pathogenicity and the physiology of O157:H7, and will open a way to fully understand the molecular mechanisms underlying the O157:H7 infection.

  11. 32 CFR 165.5 - Responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NONRECURRING COSTS ON SALES OF U.S. ITEMS § 165.5 Responsibilities. (a) The Comptroller of the Department of... of this part. (2) Review and approve nonrecurring cost recoupment charges and nonrecurring cost... military sales. (3) Ensure publication of a listing of items developed for or by the Department of Defense...

  12. Melting and thermodynamic properties of pyrope (Mg3Al2Si3O12)

    USGS Publications Warehouse

    Tequi, C.; Robie, R.A.; Hemingway, B.S.; Neuville, D.R.; Richet, P.

    1991-01-01

    The heat capacity of Mg3Al2Si3O12 glass has been measured from 10 to 1000 K by adiabatic and differential scanning calorimetry. The heat capacity of crystalline pyrope has been determined from drop-calorimetry measurements between 820 and 1300 K. From these and previously published results a consistent set of thermodynamic data is presented for pyrope and Mg3Al2Si3O12 glass and liquid for the interval 0-2000 K. The enthalpy of fusion at 1570 ?? 30 K, the metastable congruent 1-bar melting point, is 241 ?? 12 kJ/mol. ?? 1991.

  13. Thermodynamics of MgO shocked to 250 GPa and 9000 K

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.; Ahrens, T. J.

    2011-06-01

    Plate impact experiments in the 200-250 GPa pressure range were done on <100 > single-crystal MgO preheated before compression to 1850 K. Hot Mo(driver)-MgO targets were impacted with Ta flyers launched by the Caltech two-stage light-gas gun up to 7.5 km/s. Radiative temperatures and shock velocities were measured with 3-5% and 1-2% respective uncertainty by a 6-channel pyrometer with 3 ns time resolution, over 500-900 nm spectral range. MgO shock front reflectivity was determined in additional experiments at 220 and 250 GPa using 50/50 high-temperature sapphire beamsplitters. Shock temperatures and preheated MgO Hugoniot data reported here are in good agreement with the corresponding values calculated using Mie-Grüneisen equation of state with γ0 = 1.4 and constant γ / V . Our experiments showed no evidence of MgO melting up to 250 GPa and 9.2 kK. The highest shock temperatures exceed the extrapolated melting curve of Zerr & Boehler by >3000 K at 250 GPa, which seems too much for any realistic superheating.

  14. Global transcriptional response of Escherichia coli MG1655 cells exposed to the oxygenated monoterpenes citral and carvacrol.

    PubMed

    Chueca, Beatriz; Pérez-Sáez, Elisa; Pagán, Rafael; García-Gonzalo, Diego

    2017-09-18

    DNA microarrays were used to study the mechanism of bacterial inactivation by carvacrol and citral. After 10-min treatments of Escherichia coli MG1655 cells with 100 and 50ppm of carvacrol and citral, 76 and 156 genes demonstrated significant transcriptional differences (p≤0.05), respectively. Among the up-regulated genes after carvacrol treatment, we found gene coding for multidrug efflux pumps (acrA, mdtM), genes related to phage shock response (pspA, pspB, pspC, pspD, pspF and pspG), biosynthesis of arginine (argC, argG, artJ), and purine nucleotides (purC, purM). In citral-treated cells, transcription of purH and pyrB and pyrI was 2 times higher. Deletion of several differentially expressed genes confirmed the role of ygaV, yjbO, pspC, sdhA, yejG and ygaV in the mechanisms of E. coli inactivation by carvacrol and citral. These results would indicate that citral and carvacrol treatments cause membrane damage and activate metabolism through the production of nucleotides required for DNA and RNA synthesis and metabolic processes. Comparative transcriptomics of the response of E. coli to a heat treatment, which caused a significant change of the transcription of 1422 genes, revealed a much weaker response to both individual constituents of essential oils (ICs).·Thus, inactivation by citral or carvacrol was not multitarget in nature. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Acquired absolute vitamin K deficiency in a patient undergoing warfarin therapy.

    PubMed

    Takada, Hiroaki; Toru, Hifumi; Bunya, Naofumi; Kiriu, Nobuaki; Kato, Hiroshi; Koido, Yuichi; Yasuhiro, Kuroda

    2014-06-01

    We report a case of absolute vitamin K deficiency (VKD) diagnosed by measuring serum VK levels in an elderly woman undergoing warfarin therapy. A 78-year-old woman was admitted to our hospital because of dyspnea and sore throat diagnosed as pharyngitis 1 week before admission. On admission, the sore throat had exacerbated and dyspnea developed. She had history of atrial fibrillation, for which warfarin 1.5 mg/d was started approximately 10 years prior and her international normalized ratio (INR) had been maintained at an acceptable therapeutic level. Blood results revealed unmeasurable INR and abnormally prolonged activated partial thromboplastin time (APTT). She was diagnosed with adenoiditis and warfarin-related coagulopathy and administered intravenous VK (20 mg) and fresh frozen plasma (FFP; 4 U), which improved INR and APTT. Since the coagulopathy responded to intravenous VK administration, the patient was clinically diagnosed with warfarin-related relative VKD. Approximately 1 month later, she returned with complaints of sore throat. Blood results indicated abnormal INR (7.22) and APTT (N80.0 s). She was diagnosed with recurrent adenoiditis and VK deficient coagulopathy. The patient’s serum VK levels were low (VK1 level, 0.13 ng/mL; VK2 levels, 0.85 ng/mL). Initial treatment of VK (20 mg) and FFP followed by intravenous VK (20 mg/d) for 6 days, her symptoms dissipated. Warfarin was suspected to have caused absolute VKD. Severe coagulopathy in patients undergoing warfarin therapy is primarily caused by, relative VKD. However, the possibility of warfarin-related absolute VKD should be suspected when INRis not sufficiently improved by intravenous VK administration.

  16. 40 CFR 721.1655 - Alkylbenzenesulfonic acid (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzenesulfonic acid (generic... Substances § 721.1655 Alkylbenzenesulfonic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzenesulfonic acid (PMN...

  17. Self-defense of Escherichia coli against damages caused by nanoalumina.

    PubMed

    Ma, Jing; Kang, Meiling; Zhang, Yingxia; Guo, Xuan; Tian, Zhongjing; Ding, Chengshi; Wang, Hongmei

    2017-10-01

    Although studies showed effects of nanoalumina (nano-Al 2 O 3 ) on Escherichia coli, no study completely provides understanding on how bacterial cells respond to damages, especially on how they initiate self-defense. In this study, we showed three types of responses of E. coli to damages caused by nano-Al 2 O 3 . Live, dead, and injured, bacteria showed improved survival rates reaching 104%, 116%, and 104% after exposure to 0.1, 1, and 10mmol/L of nano-Al 2 O 3 respectively. Survival rates improved from 100% to 114%, corresponding to an exposure time of 0-9h, and from 100% to 127%, corresponding to 0-1000μg/L Al 3+ . Improvements were noted in survival rates of E. coli K12 MG1655, HB101, DH5α, and K12 MG1655 △lexA treated by nano-Al 2 O 3 in Luria-Bertani (LB) exposure system or K12 MG1655 in LB, normal saline(NS) and H 2 O exposure system. Bacterial cells transformed from long rods to ellipsoidal or nearly spherical as form of self-preservation mechanism; this phenomenon may be related to changes in membrane potential induced by free Al 3+ released from nano-Al 2 O 3 particles. Molecular mechanism of this response involved inhibited gene expression of sythesis and metabolism of carbohydrates, lipids and proteins. Findings presented in this study may improve understanding of potential danger of nanomaterials and control their spread to environmen. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Endoscopic evaluation of the gastro-duodenal tolerance of short-term analgesic treatment with 25 mg diclofenac-K liquid capsules.

    PubMed

    Hawkey, C; Burnett, I; Gold, M S; Garsed, K; Stevenson, D; Mannath, J; Norman, A; Shepherd, V; Subramanian, V; Johnston, R D; Brown, M

    2012-04-01

    Diclofenac-potassium (diclofenac--K) 25 mg liquid capsule is absorbed more quickly than the tablet formulation. It offers potential for rapid pain relief, but may alter gastro-duodenal tolerability. To evaluate the gastro-duodenal tolerance of diclofenac-K 25 mg liquid capsules vs. diclofenac-K 12.5 mg tablets, acetylsalicylic acid (ASA) 500 mg tablets and ibuprofen 200 mg liquid capsules. In an endoscopist-blinded, randomised, parallel-group study, volunteers received 15 doses of diclofenac-K 25 mg liquid capsules (n = 36), diclofenac-K 2 × 12.5 mg tablets (n = 36), ibuprofen 2 × 200 mg liquid capsules (n = 24) or ASA 2 × 500 mg tablets (n = 36) over 5 days. The primary outcome was the incidence of erosive gastro-duodenal lesions at Day 6. Secondary outcomes included modified Lanza score and change in gastric mucosal prostaglandin synthesis. The lowest incidence of erosive gastro-duodenal lesions was with diclofenac-K liquid capsules (53%), compared to 61% with diclofenac-K tablets (P = 0.52), 75% with ibuprofen (P = 0.08) and 94% with ASA (P = 0.001). Results were similar for the Lanza scores, although diclofenac-K liquid capsules were significantly superior to ibuprofen liquid capsules (P = 0.04). Diclofenac-K liquid capsules inhibited prostaglandin synthesis by 52% compared to 64% for diclofenac-K tablets (P = 0.10), 50% for ibuprofen (P = 0.85) and 79% for ASA (P = 0.002). With respect to safety, adverse events were most frequent in the ASA group, predominantly gastrointestinal events. Mucosal injury with diclofenac-K liquid 25 mg liquid capsules was similar to diclofenac-K 25 mg tablets, significantly lower than ASA 1 g tablets and showed some superiority over ibuprofen 400 mg liquid capsules (EudraCT Number 2009-011278-14). © 2012 Blackwell Publishing Ltd.

  19. Three diverse target preparations: 14C (12 mg/cm 2), 71Ga 24Mg (12 mg/cm 271Ga, 3 mg/cm 224Mg), and 66,67Zn (1.8-14.9 mg/cm 2)

    NASA Astrophysics Data System (ADS)

    Lozowski, W. R.

    1989-10-01

    A natural-carbon analog of fluffy, intractable 14C powder was produced. With it, a method was developed to produce a pressed disk of 14C of 12.7-mg/cm 2 thickness and 1.27-cm diameter, bound with 2.1 wt.% of adhesive. Aluminized Mylar cover foils and a fritted-disc filter were used to contain the target for ( overlinep, p') experiments. Reduction of 71Ga 2O 3 to the metal was accomplished with an efficiency of 94.3% in a small electroplating cell. Magnesium was chosen as the companion element because 50 at.% could be tolerated in the (p, n) experiment, and GaMg has a melting point of 646 K. A 1.27-cm diameter target, supported at the edge by a Mg foil, was produced in several simple steps. Directly rollable 66,67Zn foils were obtained from an electroplating cell with a Pt screen anode and a highly polished tungsten-carbide cathode. Plating times of 3 h provided metal-recovery efficiencies ranging from 94.2 to 96.5%. The as-deposited foils had many holes but were hole-free and shiny after reduction of 25% by pack rolling.

  20. Crystallization Behavior of A Bulk Amorphous Mg62Cu26Y12 Alloy

    NASA Astrophysics Data System (ADS)

    Wu, Shyue-Sheng; Chin, Tsung-Shune; Su, Kuo-Chang

    1994-07-01

    The crystallization temperature, the associated activation energy and the crystallized structure of a bulk amorphous Mg62Cu26Y12 alloy with a diameter of 2.5 mm were studied. It possesses a one-step crystallization behavior. The crystallization reaction was found to be represented by: AM(MG62Cu26Y12)→Mg2Cu+MgY+CuY+Mg, ( Tx=188°C, Eac=134 kJ/mol) where AM represents the amorphous state, T x the crystallization temperature at an infinitesimal heating rate, and E ac the associated activation energy. The amount of crystalline phases were found to be Mg2Cu:MgY:CuY=76:17:7. The Mg phase is identifiable only by high resolution electron microscopy, not by X-ray diffraction. The crystallization leads to a sharp rise in electrical resistivity which is reversed to those of iron-based amorphous alloys.

  1. RXTE/PCA and Swift/XRT observations of GRO J1655-40 during decay

    NASA Astrophysics Data System (ADS)

    Homan, Jeroen; Kong, Albert; Tomsick, John; Miller, Jon; Campana, Sergio; Wijnands, Rudy; Belloni, Tomaso; Lewin, Walter

    2005-10-01

    Following its transition to the hard state (ATels #607,#612), we have continued our daily RXTE/PCA observations of the black hole X-ray transient GRO J1655-40 (see http://tahti.mit.edu/opensource/1655). Between September 23, when the source reached the hard state, and October 10, the RXTE/ PCA count rate decreased exponentially, with an e-folding time of ~7 days. After October 10 the decrease started to slow down and data from the last few days suggest that the count rate may have reached a constant level.

  2. An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope

    NASA Astrophysics Data System (ADS)

    Haywood, Raphaëlle D.; Vanderburg, Andrew; Mortier, Annelies; Giles, Helen A. C.; López-Morales, Mercedes; Lopez, Eric D.; Malavolta, Luca; Charbonneau, David; Collier Cameron, Andrew; Coughlin, Jeffrey L.; Dressing, Courtney D.; Nava, Chantanelle; Latham, David W.; Dumusque, Xavier; Lovis, Christophe; Molinari, Emilio; Pepe, Francesco; Sozzetti, Alessandro; Udry, Stéphane; Bouchy, François; Johnson, John A.; Mayor, Michel; Micela, Giusi; Phillips, David; Piotto, Giampaolo; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Watson, Chris; Affer, Laura; Bonomo, Aldo S.; Buchhave, Lars A.; Ciardi, David R.; Fiorenzano, Aldo F.; Harutyunyan, Avet

    2018-05-01

    We present the confirmation of a small, moderately irradiated (F = 155 ± 7 F ⊕) Neptune with a substantial gas envelope in a P = 11.8728787 ± 0.0000085 day orbit about a quiet, Sun-like G0V star Kepler-1655. Based on our analysis of the Kepler light curve, we determined Kepler-1655b’s radius to be 2.213 ± 0.082 R ⊕. We acquired 95 high-resolution spectra with Telescopio Nazionale Galileo/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0{+/- }2.83.1 {M}\\oplus via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655b falls on the upper edge of the evaporation valley, in the relatively sparsely occupied transition region between rocky and gas-rich planets. It is therefore part of a population of planets that we should actively seek to characterize further.

  3. Structural insight into the rearrangement of the switch I region in GTP-bound G12A K-Ras.

    PubMed

    Xu, Shenyuan; Long, Brian N; Boris, Gabriel H; Chen, Anqi; Ni, Shuisong; Kennedy, Michael A

    2017-12-01

    K-Ras, a molecular switch that regulates cell growth, apoptosis and metabolism, is activated when it undergoes a conformation change upon binding GTP and is deactivated following the hydrolysis of GTP to GDP. Hydrolysis of GTP in water is accelerated by coordination to K-Ras, where GTP adopts a high-energy conformation approaching the transition state. The G12A mutation reduces intrinsic K-Ras GTP hydrolysis by an unexplained mechanism. Here, crystal structures of G12A K-Ras in complex with GDP, GTP, GTPγS and GppNHp, and of Q61A K-Ras in complex with GDP, are reported. In the G12A K-Ras-GTP complex, the switch I region undergoes a significant reorganization such that the Tyr32 side chain points towards the GTP-binding pocket and forms a hydrogen bond to the GTP γ-phosphate, effectively stabilizing GTP in its precatalytic state, increasing the activation energy required to reach the transition state and contributing to the reduced intrinsic GTPase activity of G12A K-Ras mutants.

  4. Structural insight into the rearrangement of the switch I region in GTP-bound G12A K-Ras

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, Shenyuan; Long, Brian N.; Boris, Gabriel H.

    K-Ras, a molecular switch that regulates cell growth, apoptosis and metabolism, is activated when it undergoes a conformation change upon binding GTP and is deactivated following the hydrolysis of GTP to GDP. Hydrolysis of GTP in water is accelerated by coordination to K-Ras, where GTP adopts a high-energy conformation approaching the transition state. The G12A mutation reduces intrinsic K-Ras GTP hydrolysis by an unexplained mechanism. Here, crystal structures of G12A K-Ras in complex with GDP, GTP, GTPγS and GppNHp, and of Q61A K-Ras in complex with GDP, are reported. In the G12A K-Ras–GTP complex, the switch I region undergoes amore » significant reorganization such that the Tyr32 side chain points towards the GTP-binding pocket and forms a hydrogen bond to the GTP γ-phosphate, effectively stabilizing GTP in its precatalytic state, increasing the activation energy required to reach the transition state and contributing to the reduced intrinsic GTPase activity of G12A K-Ras mutants.« less

  5. Interpretation of Na-K-Mg relations in geothermal waters

    USGS Publications Warehouse

    Fournier, R.O.

    1990-01-01

    When using a Na-K-???Mg triangular diagram as an aid in the interpretation of a geothermal water, the estimated temperature of last water-rock equilibration may change by as much as 50??C, depending on which of the many Na/K geothermometers one assumes is correct. A particular geothermometer may work well in one place and not in another because of differences in the mineralogy of the phases that are in contact with the reservoir fluid. The position of the full equilibrium line that is used for geothermometry and for assessing degrees of departure from equilibrium also changes as the assumed K/???Mg geothermometer equation changes. The degree of ambiguity can be evaluated by utilizing the results of all the recently published Na/K geothermometers on a single Na-K-???Mg triangular plot.

  6. Lambda Red recombinase-mediated integration of the high molecular weight DNA into the Escherichia coli chromosome.

    PubMed

    Juhas, Mario; Ajioka, James W

    2016-10-05

    Escherichia coli K-12 is a frequently used host for a number of synthetic biology and biotechnology applications and chassis for the development of the minimal cell factories. Novel approaches for integrating high molecular weight DNA into the E. coli chromosome would therefore greatly facilitate engineering efforts in this bacterium. We developed a reliable and flexible lambda Red recombinase-based system, which utilizes overlapping DNA fragments for integration of the high molecular weight DNA into the E. coli chromosome. Our chromosomal integration strategy can be used to integrate high molecular weight DNA of variable length into any non-essential locus in the E. coli chromosome. Using this approach we integrated 15 kb DNA encoding sucrose catabolism and lactose metabolism and transport operons into the fliK locus of the flagellar region 3b in the E. coli K12 MG1655 chromosome. Furthermore, with this system we integrated 50 kb of Bacillus subtilis 168 DNA into two target sites in the E. coli K12 MG1655 chromosome. The chromosomal integrations into the fliK locus occurred with high efficiency, inhibited motility, and did not have a negative effect on the growth of E. coli. In addition to the rational design of synthetic biology devices, our high molecular weight DNA chromosomal integration system will facilitate metabolic and genome-scale engineering of E. coli.

  7. Secretome Biomarkers for the Identification and Differentiation of Enterohemorrhagic and Enteropathogenic Escherichia coli Strains

    DTIC Science & Technology

    2013-09-01

    SbBS512_E4084 Shigella byodii /EC NC101 ND ND ND EC: E. coli ND: not determined 8 Table 2. Common Strain-Unique Proteins from Replicate...E24377A- Escherichia coli str. K-12 substr. MG1655- Escherichia coli SE11- Escherichia coli- W3110 Shigella boy dii CDC 3083-94- Shigella boy dii Sb227

  8. Dielectric properties and phase transition behaviors in (1-x)PbZrO3-xPb(Mg1/2W1/2)O3 ceramics

    NASA Astrophysics Data System (ADS)

    Vittayakorn, Naratip; Charoonsuk, Piyanut; Kasiansin, Panisara; Wirunchit, Supamas; Boonchom, Banjong

    2009-09-01

    The solid solution of lead zirconate [PbZrO3 (PZ)] and lead magnesium tungstate [Pb(Mg1/2W1/2)O3 (PMW)] has been synthesized by the wolframite precursor method. The crystal structure, phase transformations, dielectric and thermal properties of (1-x)PZ-xPMW, where x =0.00-0.10, were investigated. The crystal structure of sintered ceramics was analyzed by x-ray diffraction. Phase-pure perovskite was obtained for all compositions. Furthermore, a change from orthorhombic to rhombohedral symmetry was observed as the mole fraction of increased PMW. As a result, it was found that PbZrO3-Pb(Mg1/2W1/2)O3 undergoes successive transitions from the antiferroelectric phase to the ferroelectric phase to the paraelectric state. The coexistence of orthorhombic and rhombohedral phases in this binary system is located near the composition x =0.1.

  9. Transcriptomic analysis of Escherichia coli O157:H7 and K-12 cultures exposed to inorganic and organic acids in stationary phase reveals acidulant- and strain-specific acid tolerance responses.

    PubMed

    King, Thea; Lucchini, Sacha; Hinton, Jay C D; Gobius, Kari

    2010-10-01

    The food-borne pathogen Escherichia coli O157:H7 is commonly exposed to organic acid in processed and preserved foods, allowing adaptation and the development of tolerance to pH levels otherwise lethal. Since little is known about the molecular basis of adaptation of E. coli to organic acids, we studied K-12 MG1655 and O157:H7 Sakai during exposure to acetic, lactic, and hydrochloric acid at pH 5.5. This is the first analysis of the pH-dependent transcriptomic response of stationary-phase E. coli. Thirty-four genes and three intergenic regions were upregulated by both strains during exposure to all acids. This universal acid response included genes involved in oxidative, envelope, and cold stress resistance and iron and manganese uptake, as well as 10 genes of unknown function. Acidulant- and strain-specific responses were also revealed. The acidulant-specific response reflects differences in the modes of microbial inactivation, even between weak organic acids. The two strains exhibited similar responses to lactic and hydrochloric acid, while the response to acetic acid was distinct. Acidulant-dependent differences between the strains involved induction of genes involved in the heat shock response, osmoregulation, inorganic ion and nucleotide transport and metabolism, translation, and energy production. E. coli O157:H7-specific acid-inducible genes were identified, suggesting that the enterohemorrhagic E. coli strain possesses additional molecular mechanisms contributing to acid resistance that are absent in K-12. While E. coli K-12 was most resistant to lactic and hydrochloric acid, O157:H7 may have a greater ability to survive in more complex acidic environments, such as those encountered in the host and during food processing.

  10. 40 CFR 147.1655 - Requirements for wells authorized by permit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... New York § 147.1655 Requirements for wells authorized by permit. (a) The owner or operator of a Class... largest casing string. (b) The owner or operator of a new Class II well authorized by permit shall: (1... volume. (3) For new enhanced recovery wells, install tubing or long string casing extending to the...

  11. A powder neutron diffraction study of the crystal structure of the fluoroperovskite NaMgF3 (neighborite) from 300 to 3.6 K

    NASA Astrophysics Data System (ADS)

    Mitchell, Roger H.; Alexander, Malcolm; Cranswick, Lachlan M. D.; Swainson, Ian P.

    2007-12-01

    The cell dimensions and crystal structures of the fluoroperovskite NaMgF3 (neighborite), synthesized by solid state methods, have been determined by powder neutron diffraction and Rietveld refinement over the temperature range 300 3.6 K using Pt metal as an internal standard for calibration of the neutron wavelength. These data show that Pbnm NaMgF3 does not undergo any phase transitions to structures of lower symmetry with decreasing temperature. The cell dimensions and atomic coordinates together with polyhedron volumes and distortion indices are given for Pbnm NaMgF3 at 25 K intervals from 300 to 3.6 K. Decreases in the a and c cell dimensions reach a saturation point at 50 K, whereas the b dimension becomes saturated at 150 K. The distortion of the structure of Pbnm NaMgF3 from the aristotype cubic Pmifmmodeexpandafterbarelseexpandafter\\=fi{3}m structure is described in terms of the tilting of the MgF6 octahedra according to the tilt scheme a - a - c + . With decreasing temperature the antiphase tilt ( a -) increases from 14.24° to 15.39°, whereas the in-phase tilt ( c + ) remains effectively constant at ˜10.7°. Changes in the tilt angles are insufficient to cause changes in the coordination sphere of Na that might induce a low temperature phase transition. The structure of Pbnm NaMgF3 is also described in terms of normal mode analysis and displacements of the condensed normal modes are compared with those of Pbnm KCaF3.

  12. Paired measurements of K and Mg isotopes and clay authigenesis in marine sediments

    NASA Astrophysics Data System (ADS)

    Santiago Ramos, D. P.; Dunlea, A. G.; Higgins, J. A.

    2016-12-01

    Despite its importance as a major sink for seawater K and Mg, estimates of clay authigenesis in marine sediments remain poorly constrained. Previous work on Mg isotope fractionation during clay formation has revealed a preferential uptake of 26Mg, yielding authigenic clay products with potentially distinct δ26Mg compared to the detrital component. In a similar manner, we aim to quantify the K isotope fractionation during authigenic clay formation and to use paired δ26Mg and δ41K measurements as proxies for the identification and quantification of authigenic clays in shallow and deep marine sedimentary systems. To better understand the behavior of paired Mg and K isotopes during authigenic clay formation in marine sediments, we measured δ26Mg and δ41K values of pore-fluids and sediments from ODP/IODP sites 1052, U1395, U1403 and U1366. We find that while pore-fluid K concentrations at sites 1052, U1395 and U1403 all decline with depth, δ41K profiles differ significantly. These differences might be a result of a complex interplay between clay authigenesis, sedimentation rate, and fractionation of K isotopes during diffusion. Results from 1-D diffusion-advection-reaction models suggest that, in contrast to Mg, diffusion may play an important role in determining the overall K isotope fractionation during clay authigenesis in sites with low-sedimentation rates. Sites with high sedimentation rates may act as close systems where diffusion is negligible. In such cases, K uptake can be modeled as a Rayleigh distillation process and K isotope fractionation can be estimated. Measurements of δ26Mg and δ41K of pore-fluids from site U1395 and bulk sediments from U1366 suggest that paired measurements of these isotopic systems in siliciclastic marine sediments can provide new insights into rates of marine clay authigenesis, a globally important but understudied component of many geochemical cycles.

  13. The streptomycin-treated mouse intestine selects Escherichia coli envZ missense mutants that interact with dense and diverse intestinal microbiota.

    PubMed

    Leatham-Jensen, Mary P; Frimodt-Møller, Jakob; Adediran, Jimmy; Mokszycki, Matthew E; Banner, Megan E; Caughron, Joyce E; Krogfelt, Karen A; Conway, Tyrrell; Cohen, Paul S

    2012-05-01

    Previously, we reported that the streptomycin-treated mouse intestine selected nonmotile Escherichia coli MG1655 flhDC deletion mutants of E. coli MG1655 with improved colonizing ability that grow 15% faster in vitro in mouse cecal mucus and 15 to 30% faster on sugars present in mucus (M. P. Leatham et al., Infect. Immun. 73:8039-8049, 2005). Here, we report that the 10 to 20% remaining motile E. coli MG1655 are envZ missense mutants that are also better colonizers of the mouse intestine than E. coli MG1655. One of the flhDC mutants, E. coli MG1655 ΔflhD, and one of the envZ missense mutants, E. coli MG1655 mot-1, were studied further. E. coli MG1655 mot-1 is more resistant to bile salts and colicin V than E. coli MG1655 ΔflhD and grows ca. 15% slower in vitro in mouse cecal mucus and on several sugars present in mucus compared to E. coli MG1655 ΔflhD but grows 30% faster on galactose. Moreover, E. coli MG1655 mot-1 and E. coli MG1655 ΔflhD appear to colonize equally well in one intestinal niche, but E. coli MG1655 mot-1 appears to use galactose to colonize a second, smaller intestinal niche either not colonized or colonized poorly by E. coli MG1655 ΔflhD. Evidence is also presented that E. coli MG1655 is a minority member of mixed bacterial biofilms in the mucus layer of the streptomycin-treated mouse intestine. We offer a hypothesis, which we call the "Restaurant" hypothesis, that explains how nutrient acquisition in different biofilms comprised of different anaerobes can account for our results.

  14. The ternary system K2SO4MgSO4CaSO4

    USGS Publications Warehouse

    Rowe, J.J.; Morey, G.W.; Silber, C.C.

    1967-01-01

    Melting and subsolidus relations in the system K2SO4MgSO4CaSO4 were studied using heating-cooling curves, differential thermal analysis, optics, X-ray diffraction at room and high temperatures and by quenching techniques. Previous investigators were unable to study the binary MgSO4CaSO4 system and the adjacent area in the ternary system because of the decomposition of MgSO4 and CaSO4 at high temperatures. This problem was partly overcome by a novel sealed-tube quenching method, by hydrothermal synthesis, and by long-time heating in the solidus. As a result of this study, we found: (1) a new compound, CaSO4??3MgSO4 (m.p. 1201??C) with a field extending into the ternary system; (2) a high temperature form of MgSO4 with a sluggishly reversible inversion. An X-ray diffraction pattern for this polymorphic form is given; (3) the inversion of ??-CaSO4 (anhydrite) to ??-CaSO4 at 1195??C, in agreement with grahmann; (1) (4) the melting point of MgSO4 is 1136??C and that of CaSO4 is 1462??C (using sealed tube methods to prevent decomposition of the sulphates); (5) calcium langbeinite (K2SO4??2CaSO4) is the only compound in the K2SO4CaSO4 binary system. This resolved discrepancies in the results of previous investigators; (6) a continuous solid solution series between congruently melting K2SOP4??2MgSO4 (langbeinite) and incongruently melting K2SO4??2CaSO4 (calcium langbeinite); (7) the liquidus in the ternary system consists of primary phase fields of K2SO4, MgSO4, CaSO4, langbeinite-calcium langbeinite solid solution, and CaSO4??3MgSO4. The CaSO4 field extends over a large portion of the system. Previously reported fields for the compounds (K2SO4??MgSO4??nCaSO4), K2SO4??3CaSO4 and K2SO4??CaSO4 were not found; (8) a minimum in the ternary system at: 740??C, 25% MgSO4, 6% CaSO4, 69% K2SO4; and ternary eutectics at 882??C, 49% MgSO4, 19% CaSO4, 32% K2SO4; and 880??, 67??5% MgSO4, 5% CaSO4, 27??5% K2SO4. ?? 1967.

  15. Broadband High-Energy Observations of the Superluminal Jet Source GRO J1655-40 During an Outburst

    NASA Technical Reports Server (NTRS)

    Zhang, S. N.; Ebisawa, K.; Sunyaev, R.; Ueda, Y.; Harmon, B. A.; Sazonov, S.; Fishman, G. J.; Inoue, H.; Paciesas, W. S.; Takahash, T.

    1997-01-01

    The X-ray/radio transient superluminal jet source GRO J1655-40 was recently suggested to contain a black hole from optical observations. Because it is a relatively close-by system (d approximately 3.2 kpc), it can likely provide us with rich information about the physics operating in both Galactic and extragalactic jet sources. We present the first simultaneous broadband high-energy observations of GRO J1655-40 during the 1995 July-August outburst by three instruments: ASCA, WATCH/Granat, and BATSE/CGRO, in the energy band from 1 keV to 2 MeV. Our observations strengthen the interpretation that GRO J1655-40 contains a black hole. We detected a two-component energy spectrum, commonly seen from other Galactic black hole binaries, but never detected from a neutron star system. Combining our results with the mass limits derived from optical radial velocity and orbital period measurements, we further constrain the mass of the central object to be between 3.3 and 5.8 solar mass, above the well-established mass upper limit of 3.2 solar mass for a neutron star (the optical mass function for GRO J1655-40 is 3.16 + 0.2 solar mass). This system is therefore the first Galactic superluminal jet source for which there is strong evidence that the system contains a stellar mass black hole. The inclination angle of the binary system is constrained to be between 76 deg and 87 deg, consistent with estimates obtained from optical light curves and radio jet kinematics.

  16. 5 CFR 1655.3 - Information concerning the cost of a loan.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Information concerning the cost of a loan... § 1655.3 Information concerning the cost of a loan. Information concerning the cost of a loan is provided... office or service, or from the TSP record keeper). From this information, a participant can determine the...

  17. Fast growth phenotype of E. coli K-12 from adaptive laboratory evolution does not require intracellular flux rewiring

    PubMed Central

    Long, Christopher P.; Gonzalez, Jacqueline E.; Feist, Adam M.; Palsson, Bernhard O.; Antoniewicz, Maciek R.

    2018-01-01

    Adaptive laboratory evolution (ALE) is a widely-used method for improving the fitness of microorganisms in selected environmental conditions. It has been applied previously to Escherichia coli K-12 MG1655 during aerobic exponential growth on glucose minimal media, a frequently used model organism and growth condition, to probe the limits of E. coli growth rate and gain insights into fast growth phenotypes. Previous studies have described up to 1.6-fold increases in growth rate following ALE, and have identified key causal genetic mutations and changes in transcriptional patterns. Here, we report for the first time intracellular metabolic fluxes for six such adaptively evolved strains, as determined by high-resolution 13C-metabolic flux analysis. Interestingly, we found that intracellular metabolic pathway usage changed very little following adaptive evolution. Instead, at the level of central carbon metabolism the faster growth was facilitated by proportional increases in glucose uptake and all intracellular rates. Of the six evolved strains studied here, only one strain showed a small degree of flux rewiring, and this was also the strain with unique genetic mutations. A comparison of fluxes with two other wild-type (unevolved) E. coli strains, BW25113 and BL21, showed that inter-strain differences are greater than differences between the parental and evolved strains. Principal component analysis highlighted that nearly all flux differences (95%) between the nine strains were captured by only two principal components. The distance between measured and flux balance analysis predicted fluxes was also investigated. It suggested a relatively wide range of similar stoichiometric optima, which opens new questions about the path-dependency of adaptive evolution. PMID:28951266

  18. Effect of Bi(Mg1/2Ti1/2)O3 addition on the electrical properties of Si-Mn modified on SrTiO3

    NASA Astrophysics Data System (ADS)

    Roh, Yoon-ah; Masaki, Takaki; Yoon, Dae-Ho

    2015-05-01

    Single-Crystalline Strontium titanate (SrTiO3) has been widely used in many fields such as catalyst, semiconductors and dielectrics. SrTiO3 is a typical perovskite-type oxide, the physical properties of which strongly depend on its chemical composition, structure, shape, size, and crystallinity. In this work, the effects of Bi(Mg1/2Ti1/2)O3 addition on the nanostructure and the dielectric properties of Si-Mn modified SrTiO3 were investigated to develop nano-sized particles and low-temperature-fired SrTiO3-based ceramics with stable temperature characteristics. The dielectric constant of SrTiO3-Bi(Mg1/2Ti1/2)O3 was found to range from 900 to 1200 at 1 kHz for samples sintered at 1200°C. This new composition, SrTiO3-Bi(Mg1/2Ti1/2)O3, can be applied as a nano-sized dielectric materials in various fields.

  19. Ultrafast Synthesis and Related Phase Evolution of Mg2Si and Mg2Sn Compounds

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Lu, Qiangbing; Yan, Yonggao; Su, Xianli; Tang, Xinfeng

    2017-05-01

    Both Mg2Si and Mg2Sn compounds were synthesized by an ultra-fast self-propagating high-temperature synthesis (SHS) method. The data regarding SHS were obtained via theoretical calculation combined with experiments, showing that the adiabatic temperature T ad and ignition temperature T ig of Mg2Si are a little higher than those of Mg2Sn. The mechanism of phase evolution and the concomitant microstructure evolution during the synthesis process of Mg2Si and Mg2Sn compounds were investigated by adopting SHS technique coupled with a sudden quenching treatment. Differential scanning calorimetry (DSC), field emission scanning electron microscopy (FESEM), and x-ray powder diffraction (XRD) results indicate that Mg2Si compound can be directly synthesized through the reaction of Mg and Si elements at around 850 K. Correspondingly, the formation of Mg2Sn needs to undergo melting of Sn and the subsequent feeble reaction between Mg and Sn elements before the large scale transformation at 730 K. As the groundwork, this research embodies great significance for future study on the ultrafast SHS process of the ternary Mg2Si1- x Sn x solid solutions.

  20. Crystal structure of the mineral (Na,Ca,K)2(Ca,Na)4(Mg,Fe)5(Mg,Fe,Ti)5[Si12Al4O44](F,O)4: a triclinic representative of the amphibole family

    NASA Astrophysics Data System (ADS)

    Rastsvetaeva, R. K.; Aksenov, S. M.

    2012-05-01

    A mineral belonging to the amphibole family found at the Rothenberg paleovolcano (Eifel, Germany) was studied by single-crystal X-ray diffraction. The triclinic pseudomonoclinic unit-cell parameters are a = 5.3113(1) Å, b = 18.0457(3) Å; c = 9.8684(2) Å, α = 90.016(2)°, β = 105.543(4)°, γ = 89.985(2)°. The structure was solved by direct methods in sp. gr. P1 and refined to the R factor of 2.7% based on 6432 reflections with | F| > 3σ( F) taking into account twinning. The mineral with the idealized formula (Na,Ca,K)2(Ca,Na)4(Mg,Fe)5(Mg,Fe,Ti)5[Si12Al4O44](F,O)4 has some symmetry and structural features that distinguish it from other minerals of this family.

  1. Flagellar region 3b supports strong expression of integrated DNA and the highest chromosomal integration efficiency of the Escherichia coli flagellar regions.

    PubMed

    Juhas, Mario; Ajioka, James W

    2015-07-01

    The Gram-negative bacterium Escherichia coli is routinely used as the chassis for a variety of biotechnology and synthetic biology applications. Identification and analysis of reliable chromosomal integration and expression target loci is crucial for E. coli engineering. Chromosomal loci differ significantly in their ability to support integration and expression of the integrated genetic circuits. In this study, we investigate E. coli K12 MG1655 flagellar regions 2 and 3b. Integration of the genetic circuit into seven and nine highly conserved genes of the flagellar regions 2 (motA, motB, flhD, flhE, cheW, cheY and cheZ) and 3b (fliE, F, G, J, K, L, M, P, R), respectively, showed significant variation in their ability to support chromosomal integration and expression of the integrated genetic circuit. While not reducing the growth of the engineered strains, the integrations into all 16 target sites led to the loss of motility. In addition to high expression, the flagellar region 3b supports the highest efficiency of integration of all E. coli K12 MG1655 flagellar regions and is therefore potentially the most suitable for the integration of synthetic genetic circuits. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  2. Modelling the work to be done by Escherichia coli to adapt to sudden temperature upshifts.

    PubMed

    Swinnen, I A M; Bernaerts, K; Van Impe, J F

    2006-05-01

    This paper studies and models the effect of the amplitude of a sudden temperature upshift DeltaT on the adaptation period of Escherichia coli, in terms of the work to be done by the cells during the subsequent lag phase (i.e., the product of growth rate mumax and lag phase duration lambda). Experimental data are obtained from bioreactor experiments with E. coli K12 MG1655. At a predetermined time instant during the exponential growth phase, a sudden temperature upshift is applied (no other environmental changes take place). The length of the (possibly) induced lag phase and the specific growth rate after the shift are quantified with the growth model of Baranyi and Roberts (Int J Food Microbiol 23, 1994, 277). Different models to describe the evolution of the product lambda x mumax as a function of the amplitude of the temperature shift are statistically compared. The evolution of lambda x mumax is influenced by the amplitude of the temperature shift DeltaT and by the normal physiological temperature range. As some cut-off is observed, the linear model with translation is preferred to describe this evolution. This work contributes to the characterization of microbial lag phenomena, in this case for E. coli K12 MG1655, in view of accurate predictive model building.

  3. Regulation of bacteria population behaviors by AI-2 "consumer cells" and "supplier cells".

    PubMed

    Quan, Yufen; Meng, Fankang; Ma, Xinyu; Song, Xinhao; Liu, Xiao; Gao, Weixia; Dang, Yulei; Meng, Yao; Cao, Mingfeng; Song, Cunjiang

    2017-09-19

    Autoinducer-2 (AI-2) is a universal signal molecule and enables an individual bacteria to communicate with each other and ultimately control behaviors of the population. Harnessing the character of AI-2, two kinds of AI-2 "controller cells" ("consumer cells" and "supplier cells") were designed to "reprogram" the behaviors of entire population. For the consumer cells, genes associated with the uptake and processing of AI-2, which includes LsrACDB, LsrFG, LsrK, were overexpressed in varying combinations. Four consumer cell strains were constructed: Escherichia coli MG1655 pLsrACDB (NK-C1), MG1655 pLsrACDBK (NK-C2), MG1655 pLsrACDBFG (NK-C3) and MG1655 pLsrACDBFGK (NK-C4). The key enzymes responsible for production of AI-2, LuxS and Mtn, were also overexpressed, yielding strains MG1655 pLuxS (NK-SU1), and MG1655 pLuxS-Mtn (NK-SU2). All the consumer cells could decrease the environmental AI-2 concentration. NK-C2 and NK-C4 were most effective in AI-2 uptake and inhibited biofilm formation. While suppliers can increase the environmental AI-2 concentration and NK-SU2 was most effective in supplying AI-2 and facilitated biofilm formation. Further, reporter strain, MG1655 pLGFP was constructed. The expression of green fluorescent protein (GFP) in reporter cells was initiated and guided by AI-2. Mixture of consumer cells and reporter cells suggest that consumer cells can decrease the AI-2 concentration. And the supplier cells were co-cultured with reporter cells, indicating that supplier cells can provide more AI-2 compared to the control. The consumer cells and supplier cells could be used to regulate environmental AI-2 concentration and the biofilm formation. They can also modulate the AI-2 concentration when they were co-cultured with reporter cells. It can be envisioned that this system will become useful tools in synthetic biology and researching new antimicrobials.

  4. Detection of 12 micron Mg I and OH lines in stellar spectra

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.; Deming, D.; Wiedemann, G. R.; Keady, J. J.

    1986-01-01

    Infrared lines of Mg I and OH have been detected in stellar spectra near 12.3 microns. The Mg I 7i-6h transition was seen in Alpha Ori and Alpha Tau, and the R2e(23.5) and R1f(24.5) transitions of OH were seen in Alpha Ori. All lines appear in absorption, in contrast to the solar spectrum where the Mg I line shows a prominent emission core. The lack of emission in these low surface gravity stars is due to a greatly reduced volume recombination rate for the high-n states of Mg I, which is not fully compensated by the increased chromospheric scale height. The OH equivalent widths are sensitive to the temperature structure of the upper photosphere of Alpha Ori, and they indicate that the photosphere near tau 5000 of about 10 to the -5th is approximately 100 K hotter than is given by flux constant models. The OH measurements agree more closely with the 1981 semiemprical model of Basri, Linsky, and Eriksson (1981), which is based on Ca II and Mg II ultraviolet features.

  5. The in vitro biocompatibility and macrophage phagocytosis of Mg17Al12 phase in Mg-Al-Zn alloys.

    PubMed

    Liu, Chen; He, Peng; Wan, Peng; Li, Mei; Wang, Kehong; Tan, Lili; Zhang, Yu; Yang, Ke

    2015-07-01

    Mg alloys are gaining interest for applications as biodegradable medical implant, including Mg-Al-Zn series alloys with good combination of mechanical properties and reasonable corrosion resistance. However, whether the existence of second phase particles in the alloys exerts influence on the biocompatibility is still not clear. A deeper understanding of how the particles regulate specific biological responses is becoming a crucial requirement for their subsequent biomedical application. In this work, the in vitro biocompatibility of Mg17Al12 as a common second phase in biodegradable Mg-Al-Zn alloys was investigated via hemolysis, cytotoxicity, cell proliferation, and cell adhesion tests. Moreover, osteogenic differentiation was evaluated by the extracellular matrix mineralization assay. The Mg17Al12 particles were also prepared to simulate the real situation of second phase in the in vivo environment in order to estimate the cellular response in macrophages to the Mg17Al12 particles. The experimental results indicated that no hemolysis was found and an excellent cytocompatibility was also proved for the Mg17Al12 second phase when co-cultured with L929 cells, MC3T3-E1 cells and BMSCs. Macrophage phagocytosis co-culture test revealed that Mg17Al12 particles exerted no harmful effect on RAW264.7 macrophages and could be phagocytized by the RAW264.7 cells. Furthermore, the possible inflammatory reaction and metabolic way for Mg17Al12 phase were also discussed in detail. © 2014 Wiley Periodicals, Inc.

  6. Fast growth phenotype of E. coli K-12 from adaptive laboratory evolution does not require intracellular flux rewiring.

    PubMed

    Long, Christopher P; Gonzalez, Jacqueline E; Feist, Adam M; Palsson, Bernhard O; Antoniewicz, Maciek R

    2017-11-01

    Adaptive laboratory evolution (ALE) is a widely-used method for improving the fitness of microorganisms in selected environmental conditions. It has been applied previously to Escherichia coli K-12 MG1655 during aerobic exponential growth on glucose minimal media, a frequently used model organism and growth condition, to probe the limits of E. coli growth rate and gain insights into fast growth phenotypes. Previous studies have described up to 1.6-fold increases in growth rate following ALE, and have identified key causal genetic mutations and changes in transcriptional patterns. Here, we report for the first time intracellular metabolic fluxes for six such adaptively evolved strains, as determined by high-resolution 13 C-metabolic flux analysis. Interestingly, we found that intracellular metabolic pathway usage changed very little following adaptive evolution. Instead, at the level of central carbon metabolism the faster growth was facilitated by proportional increases in glucose uptake and all intracellular rates. Of the six evolved strains studied here, only one strain showed a small degree of flux rewiring, and this was also the strain with unique genetic mutations. A comparison of fluxes with two other wild-type (unevolved) E. coli strains, BW25113 and BL21, showed that inter-strain differences are greater than differences between the parental and evolved strains. Principal component analysis highlighted that nearly all flux differences (95%) between the nine strains were captured by only two principal components. The distance between measured and flux balance analysis predicted fluxes was also investigated. It suggested a relatively wide range of similar stoichiometric optima, which opens new questions about the path-dependency of adaptive evolution. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  7. Unveiling the Hybrid Genome Structure of Escherichia coli RR1 (HB101 RecA+)

    PubMed Central

    Jeong, Haeyoung; Sim, Young Mi; Kim, Hyun Ju; Lee, Sang Jun

    2017-01-01

    There have been extensive genome sequencing studies for Escherichia coli strains, particularly for pathogenic isolates, because fast determination of pathogenic potential and/or drug resistance and their propagation routes is crucial. For laboratory E. coli strains, however, genome sequence information is limited except for several well-known strains. We determined the complete genome sequence of laboratory E. coli strain RR1 (HB101 RecA+), which has long been used as a general cloning host. A hybrid genome sequence of K-12 MG1655 and B BL21(DE3) was constructed based on the initial mapping of Illumina HiSeq reads to each reference, and iterative rounds of read mapping, variant detection, and consensus extraction were carried out. Finally, PCR and Sanger sequencing-based finishing were applied to resolve non-single nucleotide variant regions with aberrant read depths and breakpoints, most of them resulting from prophages and insertion sequence transpositions that are not present in the reference genome sequence. We found that 96.9% of the RR1 genome is derived from K-12, and identified exact crossover junctions between K-12 and B genomic fragments. However, because RR1 has experienced a series of genetic manipulations since branching from the common ancestor, it has a set of mutations different from those found in K-12 MG1655. As well as identifying all known genotypes of RR1 on the basis of genomic context, we found novel mutations. Our results extend current knowledge of the genotype of RR1 and its relatives, and provide insights into the pedigree, genomic background, and physiology of common laboratory strains. PMID:28421066

  8. Maine K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 12

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2013-01-01

    The "Maine K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Maine registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels and…

  9. Giant dielectric constant in CaCu3Ti4O12-MgB2 composites near the percolation threshold

    NASA Astrophysics Data System (ADS)

    Mukherjee, Rupam; Fernandez, Lucia; Lawes, Gavin; Nadgorny, Boris

    2013-03-01

    We have investigated the enhancement of the dielectric constant K in CaCu3Ti4O12 (CCTO)-MgB2 composite near the percolation threshold. To optimize the dielectric properties of pure CCTO we have sintered the samples at variuos temperatures. We will present the results of the measurements of K in a broad frequency for pure CCTO for the samples sintered at 1100°C and 500°C. Commercially available MgB2 powder was mixed with different weight fractions of CCTO and the pressure of 1GPa was applied to form composite pellets. Near the percolation threshold PC, CCTO/MgB2 composite system exhibit a dramatic increase of the dielectric constant K by several orders of magnitude, compared to pure CCTO. We will also discuss the magnetic field dependence of the capacitance of CCTO composite powders.

  10. NASA Lewis' IITA K-12 Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA Lewis Research Center's Information Infrastructure Technology and Applications for Kindergarten to 12th Grade (IITA K-12) Program is designed to introduce into school systems computing and communications technology that benefits math and science studies. By incorporating this technology into K-12 curriculums, we hope to increase the proficiency and interest in math and science subjects by K-12 students so that they continue to study technical subjects after their high school careers are over.

  11. Role of point defects in bipolar fatigue behavior of Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3} modified (Bi{sub 1/2}K{sub 1/2})TiO{sub 3}-(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3} relaxor ceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kumar, Nitish, E-mail: nitishkumar.iitk@gmail.com; Ansell, Troy Y.; Cann, David P.

    Lead-free Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-(Bi{sub 1/2}K{sub 1/2})TiO{sub 3}-(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3} (BMT-BKT-BNT) ceramics have been shown to exhibit large electromechanical strains under high electric fields along with negligible fatigue under strong electric fields. To investigate the role of point defects on the fatigue characteristics, the composition 5BMT-40BKT-55BNT was doped to incorporate acceptor and donor defects on the A and B sites by adjusting the Bi/Na and Ti/Mg stoichiometries. All samples had pseudo-cubic symmetries based on x-ray diffraction, typical of relaxors. Dielectric measurements showed that the high and low temperature phase transitions were largely unaffected by doping. Acceptor doping resulted inmore » the observation of a typical ferroelectric-like polarization with a remnant polarization and strain hysteresis loops with significant negative strain. Donor-doped compositions exhibited characteristics that were indicative of an ergodic relaxor phase. Fatigue measurements were carried out on all of the compositions. While the A-site acceptor-doped composition showed a small degradation in maximum strain after 10{sup 6} cycles, the other compositions were essentially fatigue free. Impedance measurements were used to identify the important conduction mechanisms in these compositions. As expected, the presence of defects did not strongly influence the fatigue behavior in donor-doped compositions owing to the nature of their reversible field-induced phase transformation. Even for the acceptor-doped compositions, which had stable domains in the absence of an electric field at room temperature, there was negligible degradation in the maximum strain due to fatigue. This suggests that either the defects introduced through stoichiometric variations do not play a prominent role in fatigue in these systems or it is compensated by factors like decrease in coercive field, an increase in ergodicity, symmetry change, or other factors.« less

  12. Na(7)Mg(13)Nd(PO(4))(12).

    PubMed

    Jerbi, Hasna; Hidouri, Mourad; Mongi, Ben Amara

    2012-06-01

    Investigations of the quasi-ternary system Na(3)PO(4)-Mg(3)(PO(4))(2)-NdPO(4) allowed us to obtain the new phosphate hepta-sodium trideca-magnesium neodymium dodeca-kis-phosphate, Na(7)Mg(13)Nd(PO(4))(12), by applying a flux method. The crystal structure is isotypic with that of the previously reported Na(7)Mg(13)Ln(PO(4))(12) (Ln = Eu, La) compounds. It consists of a complex three-dimensional framework built up from an NdO(8) polyhedron (m symmetry), an MO(6) octa-hedron statistically occupied by M = Mg and Na, and eight MgO(x) (x = 5, 6) polyhedra (four with site symmetry m), linked either directely by sharing corners, edges and faces, or by one of the eight unique PO(4) tetra-hedra through common corners. Two of the PO(4) tetra-hedra are statisticaly disordered over a mirror plane. The whole structure can be described as resutling from an assembly of two types of structural units, viz [Mg(4)MP(4)O(22)](∞) (2) layers extending parallel to (100) and stacked along [100], and [Mg(4)NdP(4)O(36)](∞) (1) undulating chains running along the [010] direction. The six different Na(+) cations (five with site symmetry m and one with 0.5 occupancy) are situated in six distinct cavities delimited by the framework. The structure was refined from data of a racemic twin.

  13. Synthesis of Pt/K2CO3/MgAlOx–reduced graphene oxide hybrids as promising NOx storage–reduction catalysts with superior catalytic performance

    PubMed Central

    Mei, Xueyi; Yan, Qinghua; Lu, Peng; Wang, Junya; Cui, Yuhan; Nie, Yu; Umar, Ahmad; Wang, Qiang

    2017-01-01

    Pt/K2CO3/MgAlOx–reduced graphene oxide (Pt/K/MgAlOx–rGO) hybrids were synthesized, characterized and tested as a promising NOx storage and reduction (NSR) catalyst. Mg–Al layered double hydroxides (LDHs) were grown on rGO via in situ hydrothermal crystallization. The structure and morphology of samples were thoroughly characterized using various techniques. Isothermal NOx adsorption tests indicated that MgAlOx–rGO hybrid exhibited better NOx trapping performance than MgAlOx, from 0.44 to 0.61 mmol · g−1, which can be attributed to the enhanced particle dispersion and stabilization. In addition, a series of MgAlOx–rGO loaded with 2 wt% Pt and different loadings (5, 10, 15, and 20 wt%) of K2CO3 (denoted as Pt/K/MgAlOx–rGO) were obtained by sequential impregnation. The influence of 5% H2O on the NOx storage capacity of MgAlOx–rGO loaded with 2 wt% Pt and 10% K2CO3 (2Pt/10 K/MgAlOx–rGO) catalyst was also evaluated. In all, the 2Pt/10 K/MgAlOx–rGO catalyst not only exhibited high thermal stability and NOx storage capacity of 1.12 mmol · g−1, but also possessed excellent H2O resistance and lean–rich cycling performance, with an overall 78.4% of NOx removal. This work provided a new scheme for the preparation of highly dispersed MgAlOx–rGO hybrid based NSR catalysts. PMID:28205630

  14. Effect of the cation size on the framework structures of magnesium tungstate, A4Mg(WO4)3 (A = Na, K), R2Mg2(WO4)3 (R = Rb, Cs).

    PubMed

    Han, Shujuan; Wang, Ying; Jing, Qun; Wu, Hongping; Pan, Shilie; Yang, Zhihua

    2015-03-28

    A series of alkali metal magnesium tungstates, A4Mg(WO4)3 (A = Na, K), R2Mg2(WO4)3 (R = Rb, Cs), were synthesized from a high temperature solution, and their structures were determined by single-crystal X-ray diffraction. Interestingly, Na4Mg(WO4)3 crystallizes in the monoclinic space group C2/c, while K4Mg(WO4)3 having an identical stoichiometry with Na4Mg(WO4)3, exhibits a different framework structure belonging to triclinic symmetry with the space group P1[combining macron]. Isostructural Rb2Mg2(WO4)3 and Cs2Mg2(WO4)3 crystallize in the space group P213 of cubic symmetry and reveal a three dimensional framework composed of isolated WO4 tetrahedra, MgO6 octahedra and RO12 (R = Rb, Cs) polyhedra. The effect of the alkali metal cation size on the framework structures of magnesium tungstate has been discussed in detail. In addition, the infrared spectra, as well as the UV-Vis-NIR diffuse reflectance spectroscopy data, are reported. The first-principles theoretical studies are also carried out to aid the understanding of electronic structures and linear optical properties.

  15. Comparison of original and generic clopidogrel 600 mg loading dose in the patients who planned undergoing coronary angiography.

    PubMed

    Srimahachota, Suphot; Rojnuckarin, Ponlapat; Udayachalerm, Wasan; Buddhari, Wacin; Chaipromprasit, Jarkarpun; Lertsuwunseri, Vorarit; Akkawat, Benjaporn; Jirapattrathamrong, Somboon

    2012-12-01

    To compare the efficacy and safety of original (Plavix) and generic (Apolets) clopidogrel 600 mg loading in patients planning to undergo coronary angiography. This is an experimental design, parallel, randomized-controlled study. Coronary artery disease patients planned for cardiac catheterization were recruited Patients were randomized to receive either original or generic clopidogrel 600 mg loading dose. Platelet aggregation induced by 5 micromol/L and 20 micromol/L adenosine diphosphate (ADP) was measured by light transmission aggregometry (LTA) at baseline and 6 hours after clopidogrel 600 mg administration. Forty-nine patients were enrolled, 24 patients received original clopidogrel, and 25 patients received generic clopidogrel. After six hours of loading, there was significantly reduction in platelet aggregation induced by adenosine 5 micromol/L from 41.08 +/- 3.04% to 19.50 +/- 1.68% (p < 0.001) in original group compared to 36.76 +/- 2.66% to 21.32 +/- 2.60% (p < 0.001) in generic group. When induced by 20 micromol/L, the platelet aggregation was reduced from 58.50 +/- 2.09% to 32.25 +/- 2.30% (p < 0.001) in original group and from 61.12 +/- 2.54% to 30.04 +/- 3.14% (p < 0.001) in generic group. There was no significant difference between original and generic clopidogrel in reducing platelet aggregation induced by both adenosine 5 and 20 micromol/L. Groin hematoma was found in one case (4.2%) in the original clopidogrel group. Generic clopidogrel (Apolets) 600 mg loading dose is as effective as original clopidogrel (Plavix) in term of platelet aggregation inhibition.

  16. CCQM-K11.2 determination of glucose in human serum and CCQM-K12.2 determination of creatinine in human serum

    NASA Astrophysics Data System (ADS)

    Wise, Stephen A.; Phinney, Karen W.; Duewer, David L.; Sniegoski, Lorna T.; Welch, Michael J.; Pritchett, Jeanita; Pabello, Guiomar; Avila Calderon, Marco A.; Balderas, Miryan; Qinde, Liu; Kooi, Lee Tong; Rego, Eliane; Garrido, Bruno; Allegri, Gabriella; de La Cruz, Marcia; Barrabin, Juliana; Monteiro, Tânia; Lee, Hwashim; Kim, Byungjoo; Delatour, Vincent; Peignaux, Maryline; Kawaguchi, Migaku; Bei, Xu; Can, Quan; Nammoonnoy, Jintana; Schild, Katrin; Ohlendorf, Rüdiger; Henrion, Andre; Ceyhan Gören, Ahmet; Yılmaz, Hasibe; Bilsel, Mine; Konopelko, L.; Krylov, A.; Lopushanskaya, E.

    2018-01-01

    Glucose and creatinine are two of the most frequently measured substances in human blood/serum for assessing the health status of individuals. Because of their clinical significance, CCQM-K11 glucose in human serum and CCQM-K12 creatinine in human serum were the fourth and fifth key comparisons (KCs) performed by the Organic Analysis Working Group (OAWG). These KCs were conducted in parallel and were completed in 2001. The initial subsequent KCs for glucose, CCQM-K11.1, and creatinine, CCQM-K12.1, were completed in 2005. Measurements for the next KCs for these two measurands, CCQM-K11.2 and CCQM-K12.2, were completed in 2013. While designed as subsequent KCs, systematic discordances between the participants' and the anchor institution's results in both comparisons lead the OAWG to request reference results from two experienced laboratories that had participated in the 2001 comparisons. Based on the totality of the available information, the OAWG converted both CCQM-K11.2 and CCQM-K12.2 to 'Track C' KCs where the key comparison reference value is estimated by consensus. These comparisons highlighted that carrying out comparisons for complex chemical measurements and expecting to be able to treat them under the approaches used for formal CIPM subsequent comparisons is not an appropriate strategy. The approach used here is a compromise to gain the best value from the comparison; it is not an approach that will be used in the future. Instead, the OAWG will focus on Track A and Track C comparisons that are treated as stand-alone entities. Participation in CCQM-K11.2 demonstrates a laboratory's capabilities to measure a polar (pKow > 2), low molecular mass (100 g/mol to 500 g/mol) metabolite in human serum at relatively high concentrations (0.1 mg/g to 10 mg/g). Participation in CCQM-K12.2 demonstrates capabilities to measure similar classes of metabolites at relatively low concentrations (1 μg/g to 30 μg/g). The capabilities required for the analysis of complex

  17. Thermo and mechanoluminescence of Dy3+ activated K2Mg2(SO4)3 phosphor

    NASA Astrophysics Data System (ADS)

    Panigrahi, A. K.; Dhoble, S. J.; Kher, R. S.; Moharil, S. V.

    2003-08-01

    A solid state diffusion method for the preparation of (K2 : Dy)Mg2(SO4)3 and (K2 : Dy,P)Mg2(SO4)3 phosphors is reported. Thermoluminescence (TL) and mechanoluminescence (ML) characteristics are studied. TL, shown by the (K2 : Dy,P)Mg2(SO4)3 phosphor is 60% as intense as the conventional CaSO4 : Dy phosphor used in the TLD of ionization radiation. It has a linear TL dose response and a negligible fading. These properties of (K2 : Dy,P)Mg2(SO4)3 should be suitable in dosimetry of ionization radiation using TL technique. ML of (K2 : Dy)Mg2(SO4)3 shows one peak which has been observed in ML intensity versus time curve. The ML peak shows the recombination of electrons with free radicals (anion radicals produced by γ-irradiation) released from traps during the mechanical pressure applied on the Dy activated K2Mg2(SO4)3 phosphor. This ML mechanism is proposed for γ-irradiated sulfate based phosphors. It has been found that the total light output, i.e. ML intensity, increases with concentration of dopant, strain rate and irradiation dose of the phosphor. Mechanoluminescence and ML emission spectra of (K2 : Dy)Mg2(SO4)3 were recorded for better understanding of the ML process. The TL and ML measurements have also been performed to elucidate the mechanism of ML. Some correlation between ML and TL has also been found.

  18. Colorado K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 26

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2015-01-01

    The purpose of the "Colorado K-12 & School Choice Survey" is to measure public opinion on, and in some cases awareness or knowledge of, a range of K-12 education topics and school choice reforms. A total of 601 telephone interviews were completed from August 29 to September 16, 2015, with questions on the direction of K-12 education,…

  19. Simultaneous observations of Ca II K and Mg II k in T Tauri stars

    NASA Technical Reports Server (NTRS)

    Calvet, N.; Basri, G.; Imhoff, C. L.; Giampapa, M. S.

    1985-01-01

    The first simultaneous, calibrated observations of the Ca II K and Mg II k resonance lines in T Tauri stars are presented. It is found that for T Tauri stars with mass greater than 1.5 solar mass, which have radiative cores and tend to be fast rotators, the k line seems to arise in an extended region (probably also responsible for the H-alpha emission), whereas the K line apparently originates closer to the highly inhomogeneous stellar surface. The lower mass stars, which are fully convective and tend to be slow rotators, are more easily described by a largely chromospheric model, consistent with main-sequence activity structures but at greater values of the nonradiative flux. The strongest emission-line stars in the low-mass group, however, are also likely to have extended k line regions.

  20. Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs.

    PubMed

    Sulaiman, N N; Ismail, M

    2016-12-06

    The composite of MgH 2 /K 2 NiF 6 /carbon nanotubes (CNTs) is prepared by ball milling, and its hydrogenation properties are studied for the first time. MgH 2 co-catalyzed with K 2 NiF 6 and CNTs exhibited an improvement in the onset dehydrogenation temperature and isothermal de/rehydrogenation kinetics compared with the MgH 2 -K 2 NiF 6 composite. The onset dehydrogenation temperature of MgH 2 doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs is 245 °C, which demonstrated a reduction of 25 °C compared with the MgH 2 + 10 wt% K 2 NiF 6 composite. In terms of rehydrogenation kinetics, MgH 2 doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs samples absorbed 3.4 wt% of hydrogen in 1 min at 320 °C, whereas the MgH 2 + 10 wt% K 2 NiF 6 sample absorbed 2.6 wt% of hydrogen under the same conditions. For dehydrogenation kinetics at 320 °C, the MgH 2 + 10 wt% K 2 NiF 6 + 5 wt% CNTs sample released 3.3 wt% hydrogen after 5 min of dehydrogenation. By contrast, MgH 2 doped with 10 wt% K 2 NiF 6 released 3.0 wt% hydrogen in the same time period. The apparent activation energy, E a , for the dehydrogenation of MgH 2 doped with 10 wt% K 2 NiF 6 reduced from 100.0 kJ mol -1 to 70.0 kJ mol -1 after MgH 2 was co-doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs. Based on the experimental results, the hydrogen storage properties of the MgH 2 /K 2 NiF 6 /CNTs composite is enhanced because of the catalytic effects of the active species of KF, KH and Mg 2 Ni that are formed in situ during dehydrogenation, as well as the unique structure of CNTs.

  1. Crystal structures of K2[XSi5O12] (X = Fe2+, Co, Zn) and Rb2[XSi5O12] (X = Mn) leucites: comparison of monoclinic P21/c and Ia{\\overline 3}d polymorph structures and inverse relationship between tetrahedral cation (T = Si and X)-O bond distances and intertetrahedral T-O-T angles.

    PubMed

    Bell, Anthony M T; Henderson, C Michael B

    2018-06-01

    The leucite tectosilicate mineral analogues K 2 X 2+ Si 5 O 12 (X = Fe 2+ , Co, Zn) and Rb 2 X 2+ Si 5 O 12 (X = Mn) have been synthesized at elevated temperatures both dry at atmospheric pressure and at controlled water vapour pressure; for X = Co and Zn both dry and hydrothermally synthesized samples are available. Rietveld refinement of X-ray data for hydrothermal K 2 X 2+ Si 5 O 12 (X = Fe 2+ , Co, Zn) samples shows that they crystallize in the monoclinic space group P2 1 /c and have tetrahedral cations (Si and X) ordered onto distinct framework sites [cf. hydrothermal K 2 MgSi 5 O 12 ; Bell et al. (1994a), Acta Cryst. B50, 560-566]. Dry-synthesized K 2 X 2+ Si 5 O 12 (X = Co, Zn) and Rb 2 X 2+ Si 5 O 12 (X = Mn) samples crystallize in the cubic space group Ia{\\overline 3}d and with Si and X cations disordered in the tetrahedral framework sites as typified by dry K 2 MgSi 5 O 12 . Both structure types have tetrahedrally coordinated SiO 4 and XO 4 sharing corners to form a partially substituted silicate framework. Extraframework K + and Rb + cations occupy large channels in the framework. Structural data for the ordered samples show that mean tetrahedral Si-O and X-O bond lengths cover the ranges 1.60 Å (Si-O) to 2.24 Å (Fe 2+ -O) and show an inverse relationship with the intertetrahedral angles (T-O-T) which range from 144.7° (Si-O-Si) to 124.6° (Si-O-Fe 2+ ). For the compositions with both disordered and ordered tetrahedral cation structures (K 2 MgSi 5 O 12 , K 2 CoSi 5 O 12 , K 2 ZnSi 5 O 12 , Rb 2 MnSi 5 O 12 and Cs 2 CuSi 5 O 12 leucites) the disordered polymorphs always have larger unit-cell volumes, larger intertetrahedral T-O-T angles and smaller mean T-O distances than their isochemical ordered polymorphs. The ordered samples clearly have more flexible frameworks than the disordered structures which allow the former to undergo a greater degree of tetrahedral collapse around the interframework cavity cations. Multivariant linear regression has

  2. Nebraska Science Standards: Grades K-12

    ERIC Educational Resources Information Center

    Nebraska Department of Education, 2010

    2010-01-01

    This publication presents the Nebraska Science Standards for Grades K-12. The standards are presented according to the following grades: (1) Grades K-2; (2) Grades 3-5; (3) Grades 6-8; and (4) Grades 9-12.

  3. Giant negative electrocaloric effect in PbZrO3/0.88BaTiO3-0.12Bi(Mg1/2,Ti1/2)O3 multilayered composite ferroelectric thin film for solid-state refrigeration

    NASA Astrophysics Data System (ADS)

    Huang, D.; Wang, J. B.; Zhong, X. L.; Li, B.; Zhang, Y.; Jin, C.; Zheng, D. F.; Meng, X. J.

    2017-11-01

    A giant negative electrocaloric (EC) effect in a PbZrO3/(0.88BaTiO3-0.12 Bi(Mg1/2,Ti1/2)O3) (PZ/(BT-BMT)) multilayered composite ferroelectric (MCFE) thin film which is grown on Pt(111)/Ti/SiO2/Si(100) substrates by the sol-gel method is investigated in this work. The negative EC effect in the PZ/(BMT-BT) MCFE thin film is greatly higher than that in the PZ AFE thin film with an adiabatic temperature change (ATC) ΔT = 1.5 K. The ATC ΔT of the PZ/(BMT-BT) MCFE thin film is -32 K under the applied electric field change ΔE = 1151 kV/cm. The result is conducive to enhance the EC refrigeration efficiency greatly.

  4. A Mixed Methods Study on Teachers' Perceptions of Readiness of Higher Education Institutions to the Implementation of the K-12 Curriculum

    ERIC Educational Resources Information Center

    Acosta, Imee C.; Acosta, Alexander S.

    2017-01-01

    The Philippine Educational System is undergoing a major overhaul that shifts from a 10-year education to 12 years known as Enhanced Basic Education Curriculum or K-12. The purpose of this mixed-methods sequential explanatory study was to identify factors that determine readiness of select higher education institutions to the full implementation of…

  5. Author Reply to K12 Inc. Response

    ERIC Educational Resources Information Center

    National Education Policy Center, 2012

    2012-01-01

    K12 Inc. enrolls more public school students than any other private education management organization in the U.S. Much has been written about K12 Inc. (referred to in this report simply as "K12") by financial analysts and investigative journalists because it is a large, publicly traded company and is the dominant player in the operation…

  6. Composition, response to pressure, and negative thermal expansion in M IIB IVF 6 (M = Ca, Mg; B = Zr, Nb) [Composition, response to pressure, and negative thermal expansion in A IIB IVF 6; A - Ca, Mg, B - Zr, Nb

    DOE PAGES

    Hester, Brett R.; Hancock, Justin C.; Lapidus, Saul H.; ...

    2016-12-27

    CaZrF 6 has recently been shown to combine strong negative thermal expansion (NTE) over a very wide temperature range (at least 10–1000 K) with optical transparency from mid-IR into the UV range. Variable-temperature and high-pressure diffraction has been used to determine how the replacement of calcium by magnesium and zirconium by niobium(IV) modifies the phase behavior and physical properties of the compound. Similar to CaZrF 6, CaNbF 6 retains a cubic ReO 3-type structure down to 10 K and displays NTE up until at least 900 K. It undergoes a reconstructive phase transition upon compression to ~400 MPa at room temperature and pressure-induced amorphization above ~4 GPa. Prior to the first transition, it displays very strong pressure-induced softening. MgZrF 6 adopts a cubic ( Fmmore » $$\\bar{3}$$m) structure at 300 K and undergoes a symmetry-lowering phase transition involving octahedral tilts at ~100 K. Immediately above this transition, it shows modest NTE. Its’ thermal expansion increases upon heating, crossing through zero at ~500 K. Unlike CaZrF 6 and CaNbF 6, it undergoes an octahedral tilting transition upon compression (~370 MPa) prior to a reconstructive transition at ~1 GPa. Cubic MgZrF 6 displays both pressure-induced softening and stiffening upon heating. MgNbF 6 is cubic ( Fm$$\\bar{3}$$m) at room temperature, but it undergoes a symmetry-lowering octahedral tilting transition at ~280 K. It does not display NTE within the investigated temperature range (100–950 K). Furthermore the replacement of Zr(IV) by Nb(IV) leads to minor changes in phase behavior and properties, the replacement of the calcium by the smaller and more polarizing magnesium leads to large changes in both phase behavior and thermal expansion.« less

  7. Composition, response to pressure, and negative thermal expansion in M IIB IVF 6 (M = Ca, Mg; B = Zr, Nb) [Composition, response to pressure, and negative thermal expansion in A IIB IVF 6; A - Ca, Mg, B - Zr, Nb

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hester, Brett R.; Hancock, Justin C.; Lapidus, Saul H.

    CaZrF 6 has recently been shown to combine strong negative thermal expansion (NTE) over a very wide temperature range (at least 10–1000 K) with optical transparency from mid-IR into the UV range. Variable-temperature and high-pressure diffraction has been used to determine how the replacement of calcium by magnesium and zirconium by niobium(IV) modifies the phase behavior and physical properties of the compound. Similar to CaZrF 6, CaNbF 6 retains a cubic ReO 3-type structure down to 10 K and displays NTE up until at least 900 K. It undergoes a reconstructive phase transition upon compression to ~400 MPa at room temperature and pressure-induced amorphization above ~4 GPa. Prior to the first transition, it displays very strong pressure-induced softening. MgZrF 6 adopts a cubic ( Fmmore » $$\\bar{3}$$m) structure at 300 K and undergoes a symmetry-lowering phase transition involving octahedral tilts at ~100 K. Immediately above this transition, it shows modest NTE. Its’ thermal expansion increases upon heating, crossing through zero at ~500 K. Unlike CaZrF 6 and CaNbF 6, it undergoes an octahedral tilting transition upon compression (~370 MPa) prior to a reconstructive transition at ~1 GPa. Cubic MgZrF 6 displays both pressure-induced softening and stiffening upon heating. MgNbF 6 is cubic ( Fm$$\\bar{3}$$m) at room temperature, but it undergoes a symmetry-lowering octahedral tilting transition at ~280 K. It does not display NTE within the investigated temperature range (100–950 K). Furthermore the replacement of Zr(IV) by Nb(IV) leads to minor changes in phase behavior and properties, the replacement of the calcium by the smaller and more polarizing magnesium leads to large changes in both phase behavior and thermal expansion.« less

  8. Characteristics of Pt-K/MgAl2O4 lean NOx trap catalysts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Do Heui; Mudiyanselage, Kumudu K.; Szanyi, Janos

    2012-04-30

    We report the various characteristics of Pt-K/MgAl{sub 2}O{sub 4} lean NOx trap (LNT) catalysts including the effect of K loading on nitrate formation/decomposition, NOx storage activity and durability. Upon the adsorption of NO{sub 2} on K/MgAl{sub 2}O{sub 4} samples, potassium nitrates formed on Mg-related sites in MgAl{sub 2}O{sub 4} support are observed, in addition to the typical two potassium nitrates (ionic and bidentate) formed also on Al{sub 2}O{sub 3} supported sample. Based on NO{sub 2} TPD and FTIR results, the Mg-bound KNO{sub 3} thermally decompose at higher temperature than Al-bound KNO{sub 3}, implying its superior thermal stability. At a potassiummore » loading of 5wt%, the temperature of maximum NOx uptake (T{sub max}) is 300 C. Increasing the potassium loading from 5wt% to 10 wt%, the T{sub max} gradually shifted from 300 C to 450 C, indicating the dependence of T{sub max} on the potassium loading. However, increase in potassium loading above 10 wt% only gives rise to the reduction in the overall NOx storage capacity. This work also underlines the obstacles these materials have prior to their practical application (e.g., durability and sulfur poisoning/ removal). This work provides fundamental understanding of Pt-K/MgAl{sub 2}O{sub 4}-based lean NOx trap catalysts, which could be good candidates for high temperature LNT applications.« less

  9. Heat capacity from 12 to 305°K and entropy of talc and tremolite

    USGS Publications Warehouse

    Robie, R.A.; Stout, J.W.

    1963-01-01

    The heat capacities of talc, Mg3Si4O10(OH)2, and tremolite, Ca2Mg6Si8O22(OH)2, have been measured between 12 and 305??K. Smoothed values of heat capacity, entropy, enthalpy, and free energy are tabulated. At 298.15?? K. the values of the thermodynamic functions are: talc, Cp?? = 76.89 ?? 0.23 cal. deg.-1 mole-1, S?? = 62.33 ?? 0.19 cal. deg.-1 mole-1, H?? - H6?? = 11,206 ?? 34 cal. mole-1; tremolite, Cp?? = 156.7 ?? 0.6 cal. deg.-1 mole-1, S?? = 131.2 ?? 0.5 cal. deg.-1 mole-1, H?? - H6?? = 23,335 ?? 90 cal. mole-1. From the equilibrium data of Bowen and Tuttle and the entropy of talc, the heat of formation of talc from MgO, SiO2, and H2O (liq.) is calculated to be ??H??f298 = -43.6 ?? 1 kcal.

  10. GRO J1655-40: Early Stages of the 2005 Outburst

    NASA Technical Reports Server (NTRS)

    Shaposhnikov, N.; Swank, Jean; Shrader, C. R.; Rupen, M.; Beckmann, V.; Markwardt, C. B.; Smith, D. A.

    2007-01-01

    The black-hole X-ray binary transient GRO J1655-40 underwent an outburst beginning in early 2005. We present the results of our multi-wavelength observational campaign to study the early outburst spectral and temporal evolution, which combines data from X-ray (RXTE, INTEGRAL), radio (VLA) and optical (ROTSE, SMARTS) instruments. During the reported period the source left quiescence and went through four major accreting black hole states: low-hard, hard intermediate, soft intermediate and high-soft. We investigated dipping behavior in the RXTE band and compare our results to the 1996-1997 case, when the source was predominantly in the high-soft state, finding significant differences. We consider the evolution of the low frequency quasi-periodic oscillations and find that the frequency strongly correlates with the spectral characteristics, before shutting off prior to the transition to the high-soft state. We model the broad-band high-energy spectrum in the context of empirical models, as well as more physically motivated thermal and bulk-motion Comptonization and Compton reflection models. RXTE and INTEGRAL data together support a statistically significant high energy cut-off in the energy spectrum at approximately equal to 100 - 200 keV during the low-hard state. The RXTE data alone also show it very significantly during the transition, but cannot see one in the high-soft state spectra. We consider radio, optical and X-ray connections in the context of possible synchrotron and synchrotron self-Compton origins of X-ray emission in low-hard and intermediate states. In this outburst of GRO J1655-40, the radio flux does not rise strongly with the X-ray flux.

  11. Art Education Curriculum Guide, K-12.

    ERIC Educational Resources Information Center

    Naperville Public Schools, IL.

    GRADES OR AGES: K-12. SUBJECT MATTER: Art. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into numerous sections, one each for grades K-8, and one section for grades 9-12. Each section is in list form. The guide is mimeographed and spiral-bound with a paper cover. OBJECTIVES AND ACTIVITIES: Each section contains four sample lessons…

  12. Standards for K-12 Engineering Education?

    ERIC Educational Resources Information Center

    National Academies Press, 2010

    2010-01-01

    The goal of this study was to assess the value and feasibility of developing and implementing content standards for engineering education at the K-12 level. Content standards have been developed for three disciplines in STEM education--science, technology, and mathematic--but not for engineering. To date, a small but growing number of K-12…

  13. A survey of Mg II h and k emission in near-solar type stars

    NASA Technical Reports Server (NTRS)

    Doherty, L. R.

    1984-01-01

    International Ultraviolet Explorer measurements of Mg II h and k emission fluxes are presented for 30 F and G stars that are on or near the main sequence and compared with Wilson's measurements of the Ca II H and K fluxes in these stars. The survey includes a large proportion of stars with very low chromospheric activity as well as 111 Tau, X(1) Ori and other examples of strong chromospheric emission. Emission cores are presented in all of the stars observed. A sharp lower limit to the flux in the cores of the k lines implies the existence of a minimum level of chromospheric activity in which the k line flux is a constant fraction of stellar luminosity. Reduction of Wilson's values to absolute fluxes produces a close correlation between Mg and Ca strength with possibly some dependence on color. For the most active stars, the Mg k and Ca fluxes are consistent with the presence of solar plage covering up to one half of the stellar surface. However, the ratio of k to h in these stars is much less than this simple interpretation predicts.

  14. Steam reforming of simulated bio-oil on K-Ni-Cu-Mg-Ce-O/Al 2O 3: The effect of K

    DOE PAGES

    Yu, Ning; Rahman, Muhammad Mahfuzur; Chen, Jixiang; ...

    2018-04-10

    Steam reforming of simulated bio-oil (ethanol, acetone, phenol, and acetic acid) and phenol has been studied on K-Ni-Cu-Mg-Ce-O/Al 2O 3 composite catalysts. Complementary characterization techniques, such as nitrogen sorption, XRD, H 2-TPR, H 2-TPD, CO-TPD, CO-DRIFTS, and in situ XPS, were used to correlate surface structure and functionality to catalytic performance of potassium (K) doped catalysts. K doping of the Ni-Cu-Mg-Ce-O/Al 2O 3 catalyst created a Ni°/Ni 2+ mixed active phase, which not only enhanced steam reforming activity, but also suppressed the methanation reaction. In addition, K doping changed the surface acid-basic properties of the catalyst, which instead favor themore » gasifcation and water-gas shift reactions. In conclusion, with the combination of these effects, K doping of Ni-Cu-Mg-Ce-O/Al 2O 3 catalysts led to higher C1 yield and much lower methane formation, favoring hydrogen production in steam reforming of both phenol and simulated bio-oil.« less

  15. Steam reforming of simulated bio-oil on K-Ni-Cu-Mg-Ce-O/Al 2O 3: The effect of K

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu, Ning; Rahman, Muhammad Mahfuzur; Chen, Jixiang

    Steam reforming of simulated bio-oil (ethanol, acetone, phenol, and acetic acid) and phenol has been studied on K-Ni-Cu-Mg-Ce-O/Al 2O 3 composite catalysts. Complementary characterization techniques, such as nitrogen sorption, XRD, H 2-TPR, H 2-TPD, CO-TPD, CO-DRIFTS, and in situ XPS, were used to correlate surface structure and functionality to catalytic performance of potassium (K) doped catalysts. K doping of the Ni-Cu-Mg-Ce-O/Al 2O 3 catalyst created a Ni°/Ni 2+ mixed active phase, which not only enhanced steam reforming activity, but also suppressed the methanation reaction. In addition, K doping changed the surface acid-basic properties of the catalyst, which instead favor themore » gasifcation and water-gas shift reactions. In conclusion, with the combination of these effects, K doping of Ni-Cu-Mg-Ce-O/Al 2O 3 catalysts led to higher C1 yield and much lower methane formation, favoring hydrogen production in steam reforming of both phenol and simulated bio-oil.« less

  16. First Direct Measurement of C 12 ( C 12 , n ) Mg 23 at Stellar Energies

    DOE PAGES

    Bucher, B.; Tang, X. D.; Fang, X.; ...

    2015-06-25

    Neutrons produced by the carbon fusion reaction 12C( 12C,n) 23Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapolation at astrophysical energies. Here in this paper, we present the first direct measurement that extends deep into the astrophysical energy range along with a new and improved extrapolation technique based on experimental data from the mirror reaction 12C( 12C,p) 23Na . The new reaction rate has been determined with a well-defined uncertainty that exceeds the precision required by astrophysics models. Using our constrained rate,more » we find that 12C ( 12C,n) 23Mg is crucial to the production of Na and Al in pop-III pair instability supernovae. It also plays a nonnegligible role in the production of weak s -process elements, as well as in the production of the important galactic γ-ray emitter 60Fe.« less

  17. Heat capacities and entropies of Mg2SiOa, Mn2SiOa, and Co2SiOa between 5 and 380 K

    USGS Publications Warehouse

    Robie, Richard A.; Hemingway, Bruch S.; Takei, Humihiko

    1982-01-01

    whereas the shoulder near 12 K corresponds to the change from the collinear to a canted spin structure. Our calorimetric values for the antiferromagnetic-paramagnetictr ansition temperature (N6el Temperature) are in excellent agreement with those obtained by powder magnetic susceptibility measurements, 49t2 K and 5015 K for co2Sioa and Mn2Sioa respectively. The thermal Debye temperature, 0$, of Mg2Sioa calculated from our c$ measurements between 6.3 and 13.8 K is 768+15 K and agrees well with the elastic vaiue ofi of 758 K based on the mean sound velocity calculated from the room temperature elastic stiffness constants (ci:) of Graham and Barsch. At 298.15K (25"c) the molar heat capacitiesa re 118.6,1 28.7, and 133.4J /(mol . K) and the molar entropiesa re 94.11-r0.101, 55.910.4a nd,1 42.6-+0.J2l (mol . K) respectivelyf or Mg2SiO4M, n2SiOaa, nd Co2SiOa.

  18. K-12 Education

    Science.gov Websites

    reached out to elementary and high school students to expose them to earthquakes in a hands-on products laboratories publications nisee b.i.p. members education FAQs links education Education Program Internships K-12 Education Contact the PEER Education Program PEER's Educational Affiliates Student Design

  19. Revisit to the RXTE and ASCA Data for GRO J1655-40: Effects of Radiative Transfer in Corona and Color Hardening in the Disk

    NASA Technical Reports Server (NTRS)

    Zhang, S. Nan; Zhang, Xiaoling; Wu, Xuebing; Yao, Yangsen; Sun, Xuejun; Xu, Haiguang; Cui, Wei; Chen, Wan; Harmon, B. A.; Robinson, C. R.

    1999-01-01

    The results of spectral modeling of the data for a series of RXTE observations and four ASCA observations of GRO J1655-40 are presented. The thermal Comptonization model is used instead of the power-law model for the hard component of the two-component continuum spectra. The previously reported dramatic variations of the apparent inner disk radius of GRO J1655-40 during its outburst may be due to the inverse Compton scattering in the hot corona. A procedure is developed for making the radiative transfer correction to the fitting parameters from RXTE data and a more stable inner disk radius is obtained. A practical process of determining the color correction (hardening) factor from observational data is proposed and applied to the four ASCA observations of GRO J1655-40. We found that the color correction factor may vary significantly between different observations and the finally corrected physical inner disk radius remains reasonably stable over a large range of luminosity and spectral states.

  20. Magnetic properties of Mg12O12 nanocage doped with transition metal atoms (Mn, Fe, Co and Ni): DFT study

    NASA Astrophysics Data System (ADS)

    Javan, Masoud Bezi

    2015-07-01

    Binding energy of the Mg12O12 nanocage doped with transition metals (TM=Mn, Fe, Co and Ni) in endohedrally, exohedrally and substitutionally forms were studied using density functional theory with the generalized gradient approximation exchange-correlation functional along 6 different paths inside and outside of the Mg12O12 nanocage. The most stable structures were determined with full geometry optimization near the minimum of the binding energy curves of all the examined paths inside and outside of the Mg12O12 nanocage. The results reveal that for all stable structures, the Ni atom has a larger binding energy than the other TM atoms. It is also found that for all complexes additional peaks contributed by TM-3d, 4s and 4p states appear in the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) gap of the host MgO cluster. The mid-gap states are mainly due to the hybridization between TM-3d, 4s and 4p orbitals and the cage π orbitals. The magnetic moment of the endohedrally doped TM atoms in the Mg12O12 are preserved to some extent due to the interaction between the TM and Mg12O12 nanocage, in contrast to the completely quenched magnetic moment of the Fe and Ni atoms in the Mg11(TM)O12 complexes. Furthermore, charge population analysis shows that charge transfer occurs from TM atom to the cage for endohedrally and substitutionally doping.

  1. High doses of digoxin increase the myocardial nuclear factor-kB and CaV1.2 channels in healthy mice. A possible mechanism of digitalis toxicity.

    PubMed

    Farghaly, Hanan Sayed Mohamed; Ashry, Israa El-Sayed Mohamed; Hareedy, Mohammad Salem

    2018-06-06

    Toxic effects of digoxin may occur with normal therapeutic serum level. However, the underlying mechanisms are not fully understood. Nuclear factor kappa-B (NF-kB) is an important transcription factor in most organ systems and is often implicated in the harmful effects of cardiac injury. NF-kB promotes inflammatory responses, mediates adverse cardiac remodeling and has a function correlation with calcium. The voltage-gated L-type calcium channel CaV1.2 mediates the influx of Ca+2 into the cell in response to membrane depolarization. Our aim was to characterize the role of NF-kB during digoxin toxicity and to assess its correlation with Cav 1.2 in healthy mice in vivo. To address these questions, digoxin was administered in doses of 0.1, 1 or 5 mg/kg orally daily for seven days to the animals. Serum digoxin, serum calcium, atrial and ventricular calcium levels were measured. We, also, looked for NF-kB and CaV1.2 channel expression in cardiac muscle of mice. Digoxin at a dose of 0.1 mg/kg did not enhance serum, atrial, and ventricular Ca+2 levels, but were increased when digoxin dose of 1 and 5 mg/kg were administered. Histologically, myocardial necrosis and cellular infiltration on day 7 were significantly more severe in the 5 mg/kg/day digoxin group. Immunohistochemical studies showed more expression of both NF-kB and CaV1.2 in 1 and 5 mg/kg/day digoxin groups. These data suggest that NF-kB may be responsible for digoxin toxicity, at least partially via modulation of CaV1.2 and intracellular calcium homeostasis in the myocardium. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  2. Hydration Experiments and Physical Observations at 193 K and 243 K for Mg-Sulfates Relevant to Mars

    NASA Astrophysics Data System (ADS)

    Vaniman, D. T.; Chipera, S. J.; Carey, J. W.

    2006-03-01

    Hydration of kieserite and amorphous Mg-sulfate at 243 K progresses along simple pathways involving only hexahydrite and kieserite. Kieserite forms a duricrust-like cement, but the anhydrous precursor does not.

  3. Idaho K-12 & School Choice Survey: What Do Voters Say about K-12 Education. Polling Paper No. 5

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2012-01-01

    The "Idaho K-12 & School Choice Survey" project, commissioned by The Friedman Foundation for Educational Choice and conducted by Braun Research Incorporated (BRI), measures Idaho registered voters' familiarity and views on a range of K-12 education issues and school choice reforms. We report response "levels" and…

  4. What K-12 Leaders Can Learn from Accreditation

    ERIC Educational Resources Information Center

    Stader, David L.; Munoz, Ava J.; Rowett, Charles

    2009-01-01

    Community college Quality Enhancement Plans (QEPs) typically focus on improving student outcomes. QEPs are in many ways analogous to the campus improvement plans (CIPs) that have become standard practice for virtually all K-12 schools. K-12 campus and district leaders often seek school improvement ideas from other K-12 districts. However, much can…

  5. Drought and epidemic typhus, central Mexico, 1655-1918.

    PubMed

    Burns, Jordan N; Acuna-Soto, Rudofo; Stahle, David W

    2014-03-01

    Epidemic typhus is an infectious disease caused by the bacterium Rickettsia prowazekii and transmitted by body lice (Pediculus humanus corporis). This disease occurs where conditions are crowded and unsanitary. This disease accompanied war, famine, and poverty for centuries. Historical and proxy climate data indicate that drought was a major factor in the development of typhus epidemics in Mexico during 1655-1918. Evidence was found for 22 large typhus epidemics in central Mexico, and tree-ring chronologies were used to reconstruct moisture levels over central Mexico for the past 500 years. Below-average tree growth, reconstructed drought, and low crop yields occurred during 19 of these 22 typhus epidemics. Historical documents describe how drought created large numbers of environmental refugees that fled the famine-stricken countryside for food relief in towns. These refugees often ended up in improvised shelters in which crowding encouraged conditions necessary for spread of typhus.

  6. Minnesota K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 23

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2015-01-01

    The "Minnesota K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Minnesota registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response…

  7. Washington K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 6

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2012-01-01

    The "Washington K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research Incorporated (BRI), measures Washington registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report…

  8. Alaska K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 3

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2011-01-01

    The "Alaska K-12 & School Choice Survey" project, commissioned by The Friedman Foundation for Educational Choice and conducted by Braun Research Incorporated (BRI), measures Alaska registered voters' familiarity and views on a range of K-12 education issues and school choice reforms. The author and his colleagues report response…

  9. Study on biodegradation of the second phase Mg17Al12 in Mg-Al-Zn alloys: in vitro experiment and thermodynamic calculation.

    PubMed

    Liu, Chen; Yang, Huazhe; Wan, Peng; Wang, Kehong; Tan, Lili; Yang, Ke

    2014-02-01

    The in vitro biodegradation behavior of Mg17Al12 as a second phase in Mg-Al-Zn alloys was investigated via electrochemical measurement and immersion test. The Hank's solutions with neutral and acidic pH values were adopted as electrolytes to simulate the in vivo environment during normal and inflammatory response process. Furthermore, the local orbital density functional theory approach was employed to study the thermodynamical stability of Mg17Al12 phase. All the results proved the occurrence of pitting corrosion process with crackings for Mg17Al12 phase in Hank's solution, but with a much lower degradation rate compared with both AZ31 alloy and pure magnesium. Furthermore, a preliminary explanation on the biodegradation behaviors of Mg17Al12 phase was proposed. © 2013.

  10. Delaware K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 21

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2014-01-01

    The "Delaware K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Delaware registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels…

  11. Nevada K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 22

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2015-01-01

    The "Nevada K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Nevada registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels and…

  12. Texas K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 14

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2013-01-01

    The "Texas K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Texas registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels and…

  13. Missouri K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 19

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2014-01-01

    The "Missouri K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Missouri registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels…

  14. Oklahoma K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 18

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2014-01-01

    The "Oklahoma K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Oklahoma registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels…

  15. Montana K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 10

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2012-01-01

    The "Montana K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures Montana registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels…

  16. Louisiana K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 7

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2012-01-01

    The "Louisiana K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research Incorporated (BRI), measures Louisiana registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. In this paper the author and his colleagues…

  17. Tennessee K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 9

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2012-01-01

    The "Tennessee K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research Inc. (BRI), measures Tennessee registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response levels…

  18. Thermodynamically complete equation of state of MgO from true radiative shock temperature measurements on samples preheated to 1850 K

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.; Ahrens, T. J.

    2018-01-01

    Plate impact experiments in the 100-250 GPa pressure range were done on a 〈100 〉 single-crystal MgO preheated before compression to 1850 K. Hot Mo(driver)-MgO targets were impacted with Mo or Ta flyers launched by the Caltech two-stage light-gas gun up to 7.5 km/s. Radiative temperatures and shock velocities were measured with 3%-4% and 1%-2% uncertainty, respectively, by a six-channel pyrometer with 3-ns time resolution, over a 500-900-nm spectral range. MgO shock front reflectivity was determined in additional experiments at 220 and 248 GPa using ≈50 /50 high-temperature sapphire beam splitters. Our measurements yield accurate experimental data on the mechanical, optical, and thermodynamic properties of B1 phase MgO from 102 GPa and 3900 K to 248 GPa and 9100 K, a region not sampled by previous studies. Reported Hugoniot data for MgO initially at ambient temperature, T =298 K, and the results of our current Hugoniot measurements on samples preheated to 1850 K were analyzed using the most general methods of least-squares fitting to constrain the Grüneisen model. This equation of state (EOS) was then used to construct maximum likelihood linear Hugoniots of MgO with initial temperatures from 298 to 2400 K. A parametrization of all EOS values and best-fit coefficients was done over the entire range of relevant particle velocities. Total uncertainties of all the EOS parameters and correlation coefficients for these uncertainties are also given. The predictive capabilities of our updated Mie-Grüneisen EOS were confirmed by (1) the good agreement between our Grüneisen data and five semiempirical γ (V ) models derived from porous shock data only or from combined static and shock data sets, (2) the very good agreement between our 1-bar Grüneisen values and γ (T ) at ambient pressure recalculated from reported experimental data on the adiabatic bulk modulus Ks(T ) , and (3) the good agreement of the brightness temperatures, corrected for shock reflectivity

  19. Low daily dose of 3 mg monacolin K from RYR reduces the concentration of LDL-C in a randomized, placebo-controlled intervention.

    PubMed

    Heinz, Tina; Schuchardt, Jan Philipp; Möller, Katharina; Hadji, Peyman; Hahn, Andreas

    2016-10-01

    Hypercholesterolemia and elevated homocysteine concentrations are associated with cardiovascular risk. Previous studies have demonstrated a cholesterol-lowering effect of red yeast rice (RYR) supplements which contained 5 to 10 mg of monacolin K. We hypothesized that the intake of a low monacolin K dose may likewise reduce low-density lipoprotein-cholesterol (LDL-C) and other plasma lipids. In secondary analyses, we tested the homocysteine lowering effect of folic acid, which was also included in the study preparation. Therefore, we conducted a randomized, double-blind, and placebo-controlled intervention study. One hundred forty-two nonstatin-treated participants with hypercholesterolemia (LDL-C ≥ 4.14 ≤ 5.69 mmol/L) were randomized to the supplement group with RYR or the placebo group. Participants of the supplement group consumed 3 mg monacolin K and 200 μg folic acid per day. A significant (P < .001) reduction of LDL-C (-14.8%), total cholesterol (-11.2%), and homocysteine (-12.5%) was determined in the supplement group after 12 weeks. A total of 51% of the participants treated with RYR achieved the limit of LDL-C <4.14 mmol/L advised and 26% reached the threshold level of homocysteine <10 μmol/L. No significant changes were exhibited within the placebo group. Other parameters remained unchanged and no intolerances or serious adverse events were observed. In conclusion, we demonstrated that a low dose of daily 3 mg monacolin K from RYR reduces the concentration of LDL-C; a risk factor for cardiovascular diseases. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Simultaneous Treatment with Subcutaneous Injection of Golimumab and Intra-articular Injection of Triamcinolone Acetonide (K-Method) in Patients with Rheumatoid Arthritis Undergoing Switching of Biologics: Retrospective Case–Control Study

    PubMed Central

    Kanbe, Katsuaki; Chiba, Junji; Inoue, Yasuo; Taguchi, Masashi; Yabuki, Akiko; Deguchi, Tomohiko

    2016-01-01

    BACKGROUND Tight control of severe rheumatoid arthritis (RA) in patients with high disease activity, even when using biologics, is sometimes difficult using a treat-to-target strategy. Switching from one biologic to another is associated with lower efficacy than that in treatment-naive cases. We developed the K-method that involves simultaneous treatment with golimumab and intra-articular joint injection of triamcinolone acetonide (TA) in patients undergoing switching of biologics. We performed this retrospective case–control study to investigate the efficacy of achieving an immediate treatment response using the K-method. METHODS This study involved 20 patients with RA (control group, 10 patients; K-method group, 10 patients). Patients in the control group were switched to golimumab from other biologics without intra-articular injection of TA. The K-method involved injection of 1 mL of TA (40 mg/mL) and 2 mL of 1% lidocaine hydrochloride into swollen or painful joints on the same day as golimumab treatment. A quick response one day after treatment was compared between the two groups according to the disease activity score 28 based on C-reactive protein (DAS28 CRP), clinical disease activity index (CDAI), simplified disease activity index (SDAI), European League Against Rheumatism (EULAR) response, and remission rate. These parameters were investigated for 24 weeks. RESULTS The K-method group showed significant improvements in DAS28 CRP, CDAI, and SDAI at one day, 12 weeks, and 24 weeks compared with the control group. The number of swollen and tender joints and the patient and doctor global visual analog scale scores were also significantly different between the two groups. The remission rates based on DAS28 CRP were 30% at one day, 50% at 12 weeks, and 60% at 24 weeks in the K-method group. The EULAR good/moderate response rates were 80% at one day, 90% at 12 weeks, and 90% at 24 weeks in the K-method group; however, these rates were only 10%, 40%, and 40

  1. Indiana K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 27

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2016-01-01

    The purpose of the "Indiana K-12 & School Choice Survey" is to measure public opinion on, and in some cases awareness or knowledge of, a range of K-12 education topics and school choice reforms. The Friedman Foundation for Educational Choice developed this project in partnership with Braun Research, Inc., who conducted the live phone…

  2. Electroplating of the superconductive boride MgB2 from molten salts

    NASA Astrophysics Data System (ADS)

    Abe, Hideki; Yoshii, Kenji; Nishida, Kenji; Imai, Motoharu; Kitazawa, Hideaki

    2005-02-01

    An electroplating technique of the superconductive boride MgB2 onto graphite substrates is reported. Films of MgB2 with a thickness of tens micrometer were fabricated on the planar and curved surfaces of graphite substrates by means of electrolysis on a mixture of magnesium chloride, potassium chloride, sodium chloride, and magnesium borate fused at 600 °C under an Ar atmosphere. The electrical resistivity and magnetization measurements revealed that the electroplated MgB2 films undergo a superconducting transition with the critical temperature (Tc) of 36 K.

  3. K-12 Aerospace Education Programs

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA, the United States Air Force Academy, the Air Force Space Command, the University of Colorado at Colorado Springs (UCCS), and the United States Space Foundation teamed to produce a dynamic and successful graduate course and in-service program for K-12 educators that has a positive impact on education trends across the nation. Since 1986, more than 10,000 educators from across the United States have participated in Space Discovery and Teaching with Space affecting nearly a million students in grades K-12. The programs are designed to prepare educators to use the excitement of space to motivate students in all curriculum subjects.

  4. Nucleoli in human early erythroblasts (K2, K1, K1/2 cells).

    PubMed

    Smetana, K; Jirásková, I; Klamová, H

    2005-01-01

    Human early erythroid precursors classified according to the nuclear size were studied to provide information on nucleoli in these cells using simple cytochemical procedures for demonstration of RNA and proteins of silver-stained nucleolar organizers. K2 cells with nuclear diameter larger than 13 microm and K1 cells with nuclear diameter larger than 9 microm corresponding to proerythroblasts and macroblasts (large basophilic erythroblasts) mostly possessed large irregularly shaped nucleoli with multiple fibrillar centres representing "active nucleoli". K1/2 cells with nuclear diameter smaller than 9 microm corresponding to small basophilic erythroblasts were usually characterized by the presence of micronucleoli representing "inactive nucleolar types". On the other hand, a few K1/2 cells contained large nucleoli with multiple fibrillar centres similar to those present in K2 cells and thus appeared as "microproerythroblasts". The nucleolar asynchrony expressed by the presence of large irregularly shaped nucleoli with multiple nucleoli (active nucleoli) and ring-shaped nucleoli (resting nucleoli) in one and the same nucleus of K2 or K1 cells was not exceptional and might reflect a larger resistance of these cells to negative factors influencing the erythropoiesis. The intranucleolar translocation of silver-stained nucleolus organized regions was noted in K2 cells and might indicate the premature aging of these cells without further differentiation. More studies, however, are required in this direction.

  5. Perioperative management of vitamin K antagonists in patients with low thromboembolic risk undergoing elective surgery: A prospective experience.

    PubMed

    Becerra, Ana Florencia; Cornavaca, María Teresita; Revigliono, José Ignacio; Contreras, Alejandro; Albertini, Ricardo; Tabares, Aldo Hugo

    2017-10-11

    To quantify thromboembolic and bleeding events in patients with low thromboembolic risk, who were chronically receiving vitamin K antagonists and undergoing elective surgery. A descriptive, prospective, single-center study was conducted between December 2010 and July 2014. Patients aged over 18 years old, chronically anticoagulated with vitamin K antagonists and admitted for elective surgery were included in the study. We excluded patients with a creatinine clearance<30ml/min, a body weight>120kg, heparin-induced thrombocytopenia, pregnant women, carriers of an epidural catheter for analgesia, patients who underwent unscheduled surgery and high thromboembolic risk-patients. Vitamin K antagonists were discontinued 5 days prior to the procedure without administering anticoagulant enoxaparin. The NIR was measured 24h before the procedure. A single dose of 3mg of vitamin K was administered in cases of a NIR>1.5. Vitamin K antagonists was resumed according to the surgical bleeding risk. Events were registered between 5 days prior to the procedure until 30 days after it. A total of 75 procedures were included in the study. Fifty-six patients (74.7%) received vitamin K antagonists for atrial fibrillation, 15 suffered from venous thromboembolism (20%) and 4 had mechanical heart valves (5.3%). Twenty-six patients (34.5%) underwent high-bleeding risk surgeries and 49 (65.5%) underwent low risk procedures. No thromboembolic event was recorded. Four bleeding events (5.3%) were reported, 3 of which were considered major bleeding events (2 fatal). Suspending vitamin K antagonists with no bridging therapy performed in patients with a low thromboembolic risk does not expose such patients to a significant risk of embolic events. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  6. Proteasome inhibitor MG132 induces selective apoptosis in glioblastoma cells through inhibition of PI3K/Akt and NFkappaB pathways, mitochondrial dysfunction, and activation of p38-JNK1/2 signaling.

    PubMed

    Zanotto-Filho, Alfeu; Braganhol, Elizandra; Battastini, Ana Maria Oliveira; Moreira, José Cláudio Fonseca

    2012-12-01

    Proteasome inhibitors are emerging as a new class of anticancer agents. In this work, we examined the mechanisms underlying cytotoxicity, selectivity and adjuvant potential of the proteasome inhibitor MG132 in a panel of glioblastoma (GBM) cells (U138MG, C6, U87 and U373) and in normal astrocytes. MG132 markedly inhibited GBM cells growth irrespective of the p53 or PTEN mutational status of the cells whereas astrocytic viability was not affected, suggesting a selective toxicity of MG132 to cancerous glial cells. Mechanistically, MG132 arrested cells in G2/M phase of the cell cycle and increased p21(WAF1) protein immunocontent. Following cell arrest, cells become apoptotic as shown by annexin-V binding, caspase-3 activation, chromatin condensation and formation of sub-G1 apoptotic cells. MG132 promoted mitochondrial depolarization and decreased the mitochondrial antiapoptotic protein bcl-xL; it also induced activation of JNK and p38, and inhibition of NFkappaB and PI3K/Akt survival pathways. Pre-treatment of GBMs with the mitochondrial permeability transition pore inhibitor, bongkrekic acid, or pharmacological inhibitors of JNK1/2 and p38, SP600125 and SB203580, attenuated MG132-induced cell death. Besides its apoptotic effect alone, MG132 also enhanced the antiglioma effect of the chemotherapeutics cisplatin, taxol and doxorubicin in C6 and U138MG cells, indicating an adjuvant/chemosensitizer potential. In summary, MG132 exerted profound and selective toxicity in GBMs, being a potential agent for further testing in animal models of the disease.

  7. NON-LTE INVERSIONS OF THE Mg ii h and k AND UV TRIPLET LINES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    De la Cruz Rodríguez, Jaime; Leenaarts, Jorrit; Ramos, Andrés Asensio

    The Mg ii h and k lines are powerful diagnostics for studying the solar chromosphere. They have become particularly popular with the launch of the Interface Region Imaging Spectrograph ( IRIS ) satellite, and a number of studies that include these lines have lead to great progress in understanding chromospheric heating, in many cases thanks to the support from 3D MHD simulations. In this study, we utilize another approach to analyze observations: non-LTE inversions of the Mg ii h and k and UV triplet lines including the effects of partial redistribution. Our inversion code attempts to construct a model atmospheremore » that is compatible with the observed spectra. We have assessed the capabilities and limitations of the inversions using the FALC atmosphere and a snapshot from a 3D radiation-MHD simulation. We find that Mg ii h and k allow reconstructing a model atmosphere from the middle photosphere to the transition region. We have also explored the capabilities of a multi-line/multi-atom setup, including the Mg ii h and k, the Ca ii 854.2 nm, and the Fe i 630.25 lines to recover the full stratification of physical parameters, including the magnetic field vector, from the photosphere to the chromosphere. Finally, we present the first inversions of observed IRIS spectra from quiet-Sun, plage, and sunspot, with very promising results.« less

  8. Efficacy and safety of losartan 100 mg/hydrochlorothiazide 12.5 mg in Japanese subjects with essential hypertension: two randomized, controlled trials.

    PubMed

    Rakugi, Hiromi; Tsuchihashi, Takuya; Shimada, Kazuyuki; Numaguchi, Hirotaka; Nishida, Chisato; Yamaguchi, Hiroya; Fujimoto, Go; Azuma, Kyoichi; Shirakawa, Masayoshi; Hanson, Mary E; Fujita, Kenji P

    2014-12-01

    Two randomized studies were designed to assess the safety, tolerability and efficacy of losartan 100 mg (L100) plus hydrochlorothiazide 12.5 mg (H12.5) in a single fixed-dose combination. In one study, subjects received losartan 50 mg (L50) plus H12.5 during an 8-week filter period. They were then randomized to either L100/H12.5 or L50/H12.5 for another 8 weeks, followed by L100/H12.5 for 44 weeks. The primary end point was safety of L100/H12.5 for 52 weeks. In the second study, subjects received L100 during an 8-week filter period. Subjects were then randomized to receive either L100/H12.5 or L100 for a further 8 weeks. The primary end point was change from baseline in sitting diastolic blood pressure (SiDBP) at week 8. Safety was assessed throughout both studies. L100/H12.5 reduced SiDBP and sitting systolic blood pressure (SiSBP) at 8 weeks, and when compared with L100, the differences were statistically significant for both measures (P<0.001). L100/H12.5 reductions SiDBP for 8 weeks were comparable to L50/H12.5. The efficacy of L100/H12.5 was maintained to week 52. Drug-related adverse events with an incidence ⩾ 2% in the L100/H12.5 group during the 52-week extension period were an increase in aspartate aminotransferase and in blood uric acid. Additionally, mean uric acid levels were reduced by 0.57 mg dl(-1) from baseline with long-term treatment with L100/H12.5 in subjects whose baseline uric acid level was >7.0 mg dl(-1). In conclusion, L100/H12.5 was shown to be more effective than L100 at reducing SiDBP and SiSBP and showed good tolerability in Japanese patients with essential hypertension.

  9. K-12 Educational Outcomes of Immigrant Youth

    ERIC Educational Resources Information Center

    Crosnoe, Robert; Turley, Ruth N. Lopez

    2011-01-01

    The children from immigrant families in the United States make up a historically diverse population, and they are demonstrating just as much diversity in their experiences in the K-12 educational system. Robert Crosnoe and Ruth Lopez Turley summarize these K-12 patterns, paying special attention to differences in academic functioning across…

  10. North Dakota K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 13

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2013-01-01

    The "North Dakota K-12 & School Choice Survey" project, commissioned by the Friedman Foundation for Educational Choice and conducted by Braun Research, Inc. (BRI), measures North Dakota registered voters' familiarity and views on a range of K-12 education topics and school choice reforms. The author and his colleagues report response…

  11. New Mexico K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper Number 4

    ERIC Educational Resources Information Center

    DiPerna, Paul

    2011-01-01

    The "New Mexico K-12 & School Choice Survey" project, commissioned by The Friedman Foundation for Educational Choice and conducted by Braun Research Incorporated (BRI), measures New Mexico voters' familiarity and views on a range of K-12 education issues and school choice reforms. The author and his colleagues report response…

  12. Short-term differential adaptation to anaerobic stress via genomic mutations by Escherichia coli strains K-12 and B lacking alcohol dehydrogenase

    PubMed Central

    Kim, Hyun Ju; Jeong, Haeyoung; Hwang, Seungwoo; Lee, Moo-Seung; Lee, Yong-Jik; Lee, Dong-Woo; Lee, Sang Jun

    2014-01-01

    Microbial adaptations often occur via genomic mutations under adverse environmental conditions. This study used Escherichia coli ΔadhE cells as a model system to investigate adaptation to anaerobic conditions, which we then compared with the adaptive mechanisms of two closely related E. coli strains, K-12 and B. In contrast to K-12 ΔadhE cells, the E. coli B ΔadhE cells exhibited significantly delayed adaptive growth under anaerobic conditions. Adaptation by the K-12 and B strains mainly employed anaerobic lactate fermentation to restore cellular growth. Several mutations were identified in the pta or pflB genes of adapted K-12 cells, but mostly in the pta gene of the B strains. However, the types of mutation in the adapted K-12 and B strains were similar. Cellular viability was affected directly by severe redox imbalance in B ΔadhE cells, which also impaired their ability to adapt to anaerobic conditions. This study demonstrates that closely related microorganisms may undergo different adaptations under the same set of adverse conditions, which might be associated with the specific metabolic characteristics of each strain. This study provides new insights into short-term microbial adaptation to stressful conditions, which may reflect dynamic microbial population changes in nature. PMID:25250024

  13. Short-term differential adaptation to anaerobic stress via genomic mutations by Escherichia coli strains K-12 and B lacking alcohol dehydrogenase.

    PubMed

    Kim, Hyun Ju; Jeong, Haeyoung; Hwang, Seungwoo; Lee, Moo-Seung; Lee, Yong-Jik; Lee, Dong-Woo; Lee, Sang Jun

    2014-01-01

    Microbial adaptations often occur via genomic mutations under adverse environmental conditions. This study used Escherichia coli ΔadhE cells as a model system to investigate adaptation to anaerobic conditions, which we then compared with the adaptive mechanisms of two closely related E. coli strains, K-12 and B. In contrast to K-12 ΔadhE cells, the E. coli B ΔadhE cells exhibited significantly delayed adaptive growth under anaerobic conditions. Adaptation by the K-12 and B strains mainly employed anaerobic lactate fermentation to restore cellular growth. Several mutations were identified in the pta or pflB genes of adapted K-12 cells, but mostly in the pta gene of the B strains. However, the types of mutation in the adapted K-12 and B strains were similar. Cellular viability was affected directly by severe redox imbalance in B ΔadhE cells, which also impaired their ability to adapt to anaerobic conditions. This study demonstrates that closely related microorganisms may undergo different adaptations under the same set of adverse conditions, which might be associated with the specific metabolic characteristics of each strain. This study provides new insights into short-term microbial adaptation to stressful conditions, which may reflect dynamic microbial population changes in nature.

  14. K12 Online School Practice in China

    ERIC Educational Resources Information Center

    Chen, Li; Wang, Nan; Qiao, Ailing

    2009-01-01

    Purpose: The purpose of this paper is two fold. First, it presents the developmental stages and running modes of K12 Online Schools in China. Second, it illustrates online education practice, its current status, and the use of ICT in online schools. The experiences and lessons learned from the development of the K12 Online Schools are presented,…

  15. Economics in the School Curriculum, K-12.

    ERIC Educational Resources Information Center

    Schug, Mark C., Ed.

    Intended to help economics educators in grades K-12 foster in students the thinking skills and substantive economic knowledge necessary to become effective and participating citizens, this book is organized around four themes. Part I presents an introduction by Mark C. Schug and a section on "The Current Status of Economics in the K-12 Curriculum"…

  16. Crystal structure of the mineral (Na,Ca,K){sub 2}(Ca,Na){sub 4}(Mg,Fe){sub 5}(Mg,Fe,Ti){sub 5}[Si{sub 12}Al{sub 4}O{sub 44}](F,O){sub 4}: a triclinic representative of the amphibole family

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Aksenov, S. M.

    2012-05-15

    A mineral belonging to the amphibole family found at the Rothenberg paleovolcano (Eifel, Germany) was studied by single-crystal X-ray diffraction. The triclinic pseudomonoclinic unit-cell parameters are a = 5.3113(1) Angstrom-Sign , b = 18.0457(3) Angstrom-Sign ; c = 9.8684(2) Angstrom-Sign , {alpha} = 90.016(2) Degree-Sign , {beta} = 105.543(4) Degree-Sign , {gamma} = 89.985(2) Degree-Sign . The structure was solved by direct methods in sp. gr. P1 and refined to the R factor of 2.7% based on 6432 reflections with |F| > 3{sigma}(F) taking into account twinning. The mineral with the idealized formula (Na,Ca,K){sub 2}(Ca,Na){sub 4}(Mg,Fe){sub 5}(Mg,Fe,Ti){sub 5}[Si{sub 12}Al{sub 4}O{submore » 44}](F,O){sub 4} has some symmetry and structural features that distinguish it from other minerals of this family.« less

  17. Evolutionary Dynamics of Small RNAs in 27 Escherichia coli and Shigella Genomes

    PubMed Central

    Skippington, Elizabeth; Ragan, Mark A.

    2012-01-01

    Small RNAs (sRNAs) are widespread in bacteria and play critical roles in regulating physiological processes. They are best characterized in Escherichia coli K-12 MG1655, where 83 sRNAs constitute nearly 2% of the gene complement. Most sRNAs act by base pairing with a target mRNA, modulating its translation and/or stability; many of these RNAs share only limited complementarity to their mRNA target, and require the chaperone Hfq to facilitate base pairing. Little is known about the evolutionary dynamics of bacterial sRNAs. Here, we apply phylogenetic and network analyses to investigate the evolutionary processes and principles that govern sRNA gene distribution in 27 E. coli and Shigella genomes. We identify core (encoded in all 27 genomes) and variable sRNAs; more than two-thirds of the E. coli K-12 MG1655 sRNAs are core, whereas the others show patterns of presence and absence that are principally due to genetic loss, not duplication or lateral genetic transfer. We present evidence that variable sRNAs are less tightly integrated into cellular genetic regulatory networks than are the core sRNAs, and that Hfq facilitates posttranscriptional cross talk between the E. coli–Shigella core and variable genomes. Finally, we present evidence that more than 80% of genes targeted by Hfq-associated core sRNAs have been transferred within the E. coli–Shigella clade, and that most of these genes have been transferred intact. These results suggest that Hfq and sRNAs help integrate laterally acquired genes into established regulatory networks. PMID:22223756

  18. Drought and Epidemic Typhus, Central Mexico, 1655–1918

    PubMed Central

    Acuna-Soto, Rudofo; Stahle, David W.

    2014-01-01

    Epidemic typhus is an infectious disease caused by the bacterium Rickettsia prowazekii and transmitted by body lice (Pediculus humanus corporis). This disease occurs where conditions are crowded and unsanitary. This disease accompanied war, famine, and poverty for centuries. Historical and proxy climate data indicate that drought was a major factor in the development of typhus epidemics in Mexico during 1655–1918. Evidence was found for 22 large typhus epidemics in central Mexico, and tree-ring chronologies were used to reconstruct moisture levels over central Mexico for the past 500 years. Below-average tree growth, reconstructed drought, and low crop yields occurred during 19 of these 22 typhus epidemics. Historical documents describe how drought created large numbers of environmental refugees that fled the famine-stricken countryside for food relief in towns. These refugees often ended up in improvised shelters in which crowding encouraged conditions necessary for spread of typhus. PMID:24564928

  19. K-12 Art Guide.

    ERIC Educational Resources Information Center

    Furney, Trudy; And Others

    The development of students in various art fields is the focus of this K-12 art curriculum guide. The philosophy of the art program and the roles of administrator, teacher, and parent are outlined. The underlying school community relationships, and the objective, goals, and purposes of art education are described. Phases of child development in…

  20. Comparison between Mg II k and Ca II H images recorded by SUNRISE/SuFI

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Danilovic, S.; Hirzberger, J.; Riethmüller, T. L.

    2014-03-20

    We present a comparison of high-resolution images of the solar surface taken in the Mg II k and Ca II H channels of the Filter Imager on the balloon-borne solar observatory SUNRISE. The Mg and Ca lines are sampled with 0.48 nm and 0.11 nm wide filters, respectively. The two channels show remarkable qualitative and quantitative similarities in the quiet Sun, in an active region plage and during a small flare. However, the Mg filtergrams display 1.4-1.7 times higher intensity contrast and appear more smeared and smoothed in the quiet Sun. In addition, the fibrils in a plage are wider.more » Although the exposure time is 100 times longer for Mg images, the evidence suggests that these differences cannot be explained only with instrumental effects or the evolution of the solar scene. The differences at least partially arise because of different line-formation heights, the stronger response of Mg k emission peaks to the higher temperatures, and the larger height range sampled by the broad Mg filter used here. This is evidently manifested during the flare when a surge in Mg evolves differently than in Ca.« less

  1. Giant strain with low cycling degradation in Ta-doped [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} lead-free ceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Xiaoming; Tan, Xiaoli, E-mail: xtan@iastate.edu

    2016-07-21

    Non-textured polycrystalline [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}](Ti{sub 1−x}Ta{sub x})O{sub 3} ceramics are fabricated and their microstructures and electrical properties are characterized. Transmission electron microscopy reveals the coexistence of the rhombohedral R3c and tetragonal P4bm phases in the form of nanometer-sized domains in [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} with low Ta concentration. When the composition is x = 0.015, the electrostrain is found to be highly asymmetric under bipolar fields of ±50 kV/cm. A very large value of 0.62% is observed in this ceramic, corresponding to a large-signal piezoelectric coefficient d{sub 33}* of 1240 pm/V (1120 pm/V under unipolar loading). These values are greater thanmore » most previously reported lead-free polycrystalline ceramics and can even be compared with some lead-free piezoelectric single crystals. Additionally, this ceramic displays low cycling degradation; its electrostrain remains above 0.55% even after undergoing 10 000 cycles of ±50 kV/cm bipolar fields at 2 Hz. Therefore, Ta-doped [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} ceramics show great potential for large displacement devices.« less

  2. A Parameter Study for Modeling Mg ii h and k Emission during Solar Flares

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rubio da Costa, Fatima; Kleint, Lucia, E-mail: frubio@stanford.edu

    2017-06-20

    Solar flares show highly unusual spectra in which the thermodynamic conditions of the solar atmosphere are encoded. Current models are unable to fully reproduce the spectroscopic flare observations, especially the single-peaked spectral profiles of the Mg ii h and k lines. We aim to understand the formation of the chromospheric and optically thick Mg ii h and k lines in flares through radiative transfer calculations. We take a flare atmosphere obtained from a simulation with the radiative hydrodynamic code RADYN as input for a radiative transfer modeling with the RH code. By iteratively changing this model atmosphere and varying thermodynamicmore » parameters such as temperature, electron density, and velocity, we study their effects on the emergent intensity spectra. We reproduce the typical single-peaked Mg ii h and k flare spectral shape and approximate the intensity ratios to the subordinate Mg ii lines by increasing either densities, temperatures, or velocities at the line core formation height range. Additionally, by combining unresolved upflows and downflows up to ∼250 km s{sup −1} within one resolution element, we reproduce the widely broadened line wings. While we cannot unambiguously determine which mechanism dominates in flares, future modeling efforts should investigate unresolved components, additional heat dissipation, larger velocities, and higher densities and combine the analysis of multiple spectral lines.« less

  3. The Mg II h and k lines. II - Comparison with synthesized profiles and Ca II K. [solar spectra

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.; Linsky, J. L.

    1976-01-01

    Measured high-dispersion center and limb profiles of the solar Mg II h and k resonance lines are compared with synthetic spectra computed with a partial-redistribution formalism and based on several upper-photosphere and lower-chromosphere temperature distributions. Profiles of the analogously formed Ca II K resonance line are also synthesized for the same atmospheric models. The spectrum-synthesis approach is outlined, and the collisional and fixed radiative rates appropriate to the adopted model atoms and solar atmosphere are discussed. It is found that the HSRA and VAL models predict systematically lower intensities in the h, k, and K inner wings than observed and that models with a somewhat higher minimum temperature (about 4450 K) can reproduce the measured inner wings and limb darkening. A 'Ca II' solar model with a minimum temperature of 4450 K is proposed as an alternative to the class of models based on continuum observations.

  4. Laboratory Safety Guide for Arkansas K-12 Schools.

    ERIC Educational Resources Information Center

    Arkansas State Dept. of Education, Little Rock.

    This document presents laboratory safety rules for Arkansas K-12 schools which were developed by the Arkansas Science Teachers Association (ASTA) and the Arkansas Department of Education (ADE). Contents include: (1) "Laboratory Safety Guide for Arkansas K-12 Schools"; (2) "Safety Considerations"; (3) "Safety Standards for Science Laboratories";…

  5. Accelerated anaerobic release of K, Mg and P from surplus activated sludge for element recovery and struvite formation inhibition.

    PubMed

    Ito, A; Kawakami, H; Ishikawa, N; Ito, M; Oikawa, T; Sato, A; Umita, T

    2017-05-01

    Accelerated release of potassium (K), magnesium (Mg) and phosphorus (P) from surplus activated sludge (SAS) was investigated to develop a new system for the recovery of the elements. Anaerobic cultivation of SAS during 24 h released 78% of K and about 50% of Mg and P from SAS more effectively compared to aerobic cultivation (K: 40%, Mg: 15%, P: 15%). Furthermore, the addition of sodium acetate as an organic carbon source remarkably accelerated the release of K, Mg and P from SAS under anaerobic condition. However, no increase in the maximum release efficiencies was observed. The elements released from SAS could be transferred to separate liquid with the existing mechanical thickener and be recovered as MgKPO 4 by some additional process. Furthermore, the removal of the elements from SAS would inhibit the formation of struvite causing the blockage of sludge transport pipe after anaerobic digestion process of thickened sludge.

  6. Many Mg-Mg bonds form the core of the Mg16Cp*8Br4K cluster anion: the key to a reassessment of the Grignard reagent (GR) formation process?

    PubMed

    Kruczyński, T; Henke, F; Neumaier, M; Bowen, K H; Schnöckel, H

    2016-02-01

    It caused a sensation eight years ago, when the first room temperature stable molecular compound with a Mg-Mg bond (LMgMgL, L = chelating ligand) containing magnesium in the oxidation state +1 was prepared. Here, we report the preparation of a [Mg 16 Cp*8Br 4 K] - cluster anion (Cp* = pentamethylcyclopentadiene) with 27 Mg-Mg bonds. It has been obtained through the reaction of KCp* with a metastable solution of MgBr in toluene. A highly-resolved Fourier transform mass spectrum (FT-MS) of this cluster anion, brought into vacuum by electrospraying its solution in THF, provides the title cluster's stoichiometry. This Mg 16 cluster together with experiments on the metastable solution of MgBr show that: during the formation process of GRs (Grignard reagents) which are involved in most of sophisticated syntheses of organic products, not the highly reactive MgBr radical as often presumed, but instead the metalloid Mg 16 Cp*8Br 4 cluster anion and its related cousins that are the operative intermediates along the pathway from Mg metal to GRs ( e.g. Cp*MgBr).

  7. L alpha, L beta /of H I/, K and H /of MG II/, K and H /of CA II/ observations in a quiescent prominence with the OSO-8 LPSP instrument

    NASA Astrophysics Data System (ADS)

    Vial, J. C.; Martres, M. J.; Salm-Platzer, J.

    1981-04-01

    A sequence of images taken at different positions in the resonance lines of Ca II, Mg II, and H I was obtained over a quiescent prominence with the LPSP instrument on OSO-8. Ca II K (and H) profiles are reconstructed at different locations in the prominence with a (10 × 5) arc sec2 resolution. Significant variations of FWHM and line shifts are found: FWHM range from 0.14 Å to 0.5 Å; blue shifts reach about 14 km s-1. The ratio of K to H absolute intensities shows a large spread around the average value of 1.2. The same ratio for the Mg II lines in the whole prominence is higher (1.7), a fact already noticed at the edge of an active prominence (Vial et al., 1979). The ionization degree, as measured by the Lα/Ca K ratio, shows noticeable variations within the prominence. The La intensity is about 0.3 times the intensity measured in the quiet Sun, and the Lα/Lβ ratio is less than one half the disk value. These results indicate important variations of the thermal conditions inside the prominence.

  8. Hydriding and dehydriding rates of Mg, Mg-10TaF5, and Mg-10NbF5 prepared via reactive mechanical grinding

    NASA Astrophysics Data System (ADS)

    Song, Myoung Youp; Kwak, Young Jun; Lee, Seong Ho; Park, Hye Ryoung

    2015-01-01

    In this work, TaF5 and NbF5 were chosen as additives to enhance the hydriding and dehydriding rates of Mg. Mg, Mg-10TaF5, and Mg-10NbF5 samples were prepared by reactive mechanical grinding. The hydriding and dehydriding properties of the samples were then examined. Mg-10TaF5 had the largest amount of hydrogen absorbed for 30 min and the highest initial dehydriding rate after incubation period, followed in order by Mg-10NbF5, and Mg. At 593 K under 12 bar H2 at the first cycle, Mg-10TaF5 absorbed 3.63 wt% H for 5 min and 4.53 wt% H for 30 min. At 593 K under 1.0 bar H2 at the first cycle, Mg-10TaF5 desorbed 0 wt% H for 2.5 min, 0.59 wt% H for 5 min, 3.42 wt% H for 30 min, and 4.24 wt% H for 60 min. The reactive mechanical grinding of Mg with TaF5 or NbF5 is believed to have facilitated the nucleation and to have decreased the diffusion distances of hydrogen atoms. These two effects are believed to have increased the hydriding and dehydriding rates of Mg. The MgF2 and Ta2H formed in Mg-10TaF5, and the MgF2, NbH2, and NbF3 formed in Mg-10NbF5 are considered to have enhanced both of these effects.

  9. Keeping Pace with K-12 Online Learning, 2016

    ERIC Educational Resources Information Center

    Gemin, Butch; Pape, Larry

    2017-01-01

    "Keeping Pace with K-12 Online Learning 2016" marks the thirteenth consecutive year Evergreen has published its annual research of the K-12 education online learning market. The thirteen years of researching, writing and publishing this report represents a time of remarkable change. There has been a constant presence that has become the…

  10. Fast and accurate determination of K, Ca, and Mg in human serum by sector field ICP-MS.

    PubMed

    Yu, Lee L; Davis, W Clay; Nuevo Ordonez, Yoana; Long, Stephen E

    2013-11-01

    Electrolytes in serum are important biomarkers for skeletal and cellular health. The levels of electrolytes are monitored by measuring the Ca, Mg, K, and Na in blood serum. Many reference methods have been developed for the determination of Ca, Mg, and K in clinical measurements; however, isotope dilution thermal ionization mass spectrometry (ID-TIMS) has traditionally been the primary reference method serving as an anchor for traceability and accuracy to these secondary reference methods. The sample matrix must be separated before ID-TIMS measurements, which is a slow and tedious process that hindered the adoption of the technique in routine clinical measurements. We have developed a fast and accurate method for the determination of Ca, Mg, and K in serum by taking advantage of the higher mass resolution capability of the modern sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Each serum sample was spiked with a mixture containing enriched (44)Ca, (26)Mg, and (41)K, and the (42)Ca(+):(44)Ca(+), (24)Mg(+):(26)Mg(+), and (39)K(+):(41)K(+) ratios were measured. The Ca and Mg ratios were measured in medium resolution mode (m/Δm ≈ 4 500), and the K ratio in high resolution mode (m/Δm ≈ 10 000). Residual (40)Ar(1)H(+) interference was still observed but the deleterious effects of the interference were minimized by measuring the sample at K > 100 ng g(-1). The interferences of Sr(++) at the two Ca isotopes were less than 0.25 % of the analyte signal, and they were corrected with the (88)Sr(+) intensity by using the Sr(++):Sr(+) ratio. The sample preparation involved only simple dilutions, and the measurement using this sample preparation approach is known as dilution-and-shoot (DNS). The DNS approach was validated with samples prepared via the traditional acid digestion approach followed by ID-SF-ICP-MS measurement. DNS and digested samples of SRM 956c were measured with ID-SF-ICP-MS for quality assurance, and the results (mean

  11. Retaining K-12 Online Teachers: A Predictive Model for K-12 Online Teacher Turnover

    ERIC Educational Resources Information Center

    Larkin, Ingle M.; Lokey-Vega, Anissa; Brantley-Dias, Laurie

    2018-01-01

    The purpose of this study was to measure and explore factors influencing K-12 online teachers' turnover intentions, with job satisfaction and organizational commitment serving as moderating variables. Using Fishbein and Ajzen's Theory of Reasoned Action and Planned Behavior (1975), this study was conducted in public, private, charter, for-profit,…

  12. Antisense Oligonucleotide-Based Splicing Correction in Individuals with Leber Congenital Amaurosis due to Compound Heterozygosity for the c.2991+1655A>G Mutation in CEP290.

    PubMed

    Duijkers, Lonneke; van den Born, L Ingeborgh; Neidhardt, John; Bax, Nathalie M; Pierrache, Laurence H M; Klevering, B Jeroen; Collin, Rob W J; Garanto, Alejandro

    2018-03-07

    Leber congenital amaurosis (LCA) is a rare inherited retinal disorder affecting approximately 1:50,000 people worldwide. So far, mutations in 25 genes have been associated with LCA, with CEP290 (encoding the Centrosomal protein of 290 kDa) being the most frequently mutated gene. The most recurrent LCA-causing CEP290 mutation, c.2991+1655A>G, causes the insertion of a pseudoexon into a variable proportion of CEP290 transcripts. We previously demonstrated that antisense oligonucleotides (AONs) have a high therapeutic potential for patients homozygously harbouring this mutation, although to date, it is unclear whether rescuing one single allele is enough to restore CEP290 function. Here, we assessed the AON efficacy at RNA, protein and cellular levels in samples that are compound heterozygous for this mutation, together with a protein-truncating mutation in CEP290 . We demonstrate that AONs can efficiently restore splicing and increase protein levels. However, due to a high variability in ciliation among the patient-derived cell lines, the efficacy of the AONs was more difficult to assess at the cellular level. This observation points towards the importance of the severity of the second allele and possibly other genetic variants present in each individual. Overall, AONs seem to be a promising tool to treat CEP290 -associated LCA, not only in homozygous but also in compound heterozygous carriers of the c.2991+1655A>G variant.

  13. Identification of a site involved in the block by extracellular Mg2+ and Ba2+ as well as permeation of K+ in the Kir2.1 K+ channel

    PubMed Central

    Murata, Yoshimichi; Fujiwara, Yuichiro; Kubo, Yoshihiro

    2002-01-01

    The inward rectifier potassium channel Kir2.1 is more sensitive to the weakly voltage-dependent block by extracellular Mg2+ (Mg02+) than Kir2.2 and Kir2.3. We identified Glu125 in an extracellular loop before the pore region of Kir2.1 as a site responsible for this sensitivity to M02+ block, based on the observations that the Glu125Gln (E125Q) mutation strongly decreased the sensitivity, while a mutation to Glu at the corresponding sites of Kir2.2 and 2.3 led to an increase. The negative charge proved to be crucial since the Glu125Asp (E125D) mutant showed similar properties to the wild type (WT). A similar weakly voltage-dependent block was also caused by extracellular Ca2+ and La3+ in Kir2.1 WT but not in the E125Q mutant. The sensitivity to block by extracellular Ba2+ (Ba02+) was also decreased in the E125Q mutant, although the voltage dependency of half-inhibition concentration was not changed, as reported previously. We additionally observed that the speed of Ba02+ block and recovery was decelerated by the presence of Mg02+ in WT, but not in the E125Q mutant. The sensitivity to the block by Mg02+ was increased by lowering extracellular K+ (K0+), suggesting a competitive interaction of Mg02+ and K0+. The single-channel conductance of the WT in 140 mm K+ was 39.6 pS (0 mm Mg02+) and 11.5 pS (10 mm), while that of the E125Q mutant was 26.0 pS (0 mm) and 19.6 pS (10 mm). These results demonstrate that Mg2+ competes with K+ permeation in the WT and that E125 is required for efficient K+ permeation in the absence of Mg02+. We conclude that E125 in an extracellular loop of Kir2.1 is a site which facilitates K+ permeation and entry of Ba2+ toward a deeper plugging site, and that Mg02+ competes with K0+ and Ba02+ at this site. PMID:12411513

  14. Rethinking Museums' Adult Education for K-12 Teachers

    ERIC Educational Resources Information Center

    Marcus, Alan S.

    2008-01-01

    This article explores the importance of developing strong adult education programs within a broader collaborative effort between museum staff and K-12 teachers. Focusing on history museums, the first section discusses the importance of museum visits for K-12 history learning and how we need to reconsider some of the primary purposes for these…

  15. A precise determination of black hole spin in GRO J1655-40

    NASA Astrophysics Data System (ADS)

    Abramowicz, M. A.; Kluźniak, W.

    2001-08-01

    We note that the recently discovered 450 Hz frequency in the X-ray flux of the black hole candidate GRO J1655-40 is in a 3:2 ratio to the previously known 300 Hz frequency of quasi-periodic oscillations (QPO) in the same source. If the origin of high frequency QPOs in black hole systems is a resonance between orbital and epicyclic motion of accreting matter, as suggested previously, the angular momentum of the black hole can be accurately determined, given its mass. We find that the dimensionless angular momentum is in the range 0.2

  16. Temporal dissection of K-ras(G12D) mutant in vitro and in vivo using a regulatable K-ras(G12D) mouse allele.

    PubMed

    Wang, Zuoyun; Feng, Yan; Bardeesy, Nabeel; Bardessy, Nabeel; Wong, Kwok-Kin; Liu, Xin-Yuan; Ji, Hongbin

    2012-01-01

    Animal models which allow the temporal regulation of gene activities are valuable for dissecting gene function in tumorigenesis. Here we have constructed a conditional inducible estrogen receptor-K-ras(G12D) (ER-K-ras(G12D)) knock-in mice allele that allows us to temporally switch on or off the activity of K-ras oncogenic mutant through tamoxifen administration. In vitro studies using mice embryonic fibroblast (MEF) showed that a dose of tamoxifen at 0.05 µM works optimally for activation of ER-K-ras(G12D) independent of the gender status. Furthermore, tamoxifen-inducible activation of K-ras(G12D) promotes cell proliferation, anchor-independent growth, transformation as well as invasion, potentially via activation of downstream MAPK pathway and cell cycle progression. Continuous activation of K-ras(G12D) in vivo by tamoxifen treatment is sufficient to drive the neoplastic transformation of normal lung epithelial cells in mice. Tamoxifen withdrawal after the tumor formation results in apoptosis and tumor regression in mouse lungs. Taken together, these data have convincingly demonstrated that K-ras mutant is essential for neoplastic transformation and this animal model may provide an ideal platform for further detailed characterization of the role of K-ras oncogenic mutant during different stages of lung tumorigenesis.

  17. State of the Nation: K-12 Online Learning in Canada

    ERIC Educational Resources Information Center

    Barbour, Michael K.

    2009-01-01

    The goal of the initial "Snapshot State of the Nation: K-12 Online Learning in Canada" report was to provide an overview of the state of K-12 online learning in Canada. This was accomplished through the use of short commentaries about the state of K-12 distance education for each province and territory, along with more developed case…

  18. Precipitates and voids in cubic silicon carbide implanted with 25Mg+ ions

    NASA Astrophysics Data System (ADS)

    Jiang, Weilin; Spurgeon, Steven R.; Liu, Jia; Schreiber, Daniel K.; Jung, Hee Joon; Devaraj, Arun; Edwards, Danny J.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

    2018-01-01

    Single crystal cubic phase silicon carbide (3C-SiC) films on Si were implanted to 9.6 × 101625Mg+/cm2 at 673 K and annealed at 1073 and 1573 K for 2, 6, and 12 h in an Ar environment. The data from scanning transmission election microscopy (STEM) and electron energy loss spectroscopy (EELS) mapping suggest a possible formation of unidirectionally aligned tetrahedral precipitates of core (MgC2)-shell (Mg2Si) in the implanted sample annealed at 1573 K for 12 h. There are also small spherical voids near the surface and larger faceted voids around the region of maximum vacancy concentration. Atom probe tomography confirms 25Mg segregation dominated by small atomic clusters with local 25Mg concentrations up to 85 at.%. The resulting precipitate size and number density are found to decrease and increase, respectively, probably as a result of the thermal annealing that decomposes the 25Mg-bearing precipitates at the elevated temperatures and subsequent nucleation and growth below 1073 K during the cooling stage. The results from this study provide data needed to fully understand the property degradation of SiC in a high-flux fast neutron environment.

  19. Scientists and K-12: Experience from The Science House

    NASA Astrophysics Data System (ADS)

    Haase, David G.

    2003-03-01

    In working with K-12 science and mathematics education, scientists may take on many different roles - from presenter to full-time partner. These roles are illustrated in the activities of The Science House, a K-12 education program of North Carolina State University, (www.science-house.org) which partners with teachers and students across the state to promote inquiry-based learning in mathematics and science. While it is important to involve scientists in K-12, most universities do not have effective means to make the connections. In our efforts to do so, which began with a few teacher workshops and now encompasses six offices across NC, we have sought to join the interests of the university (research, teaching, student recruiting) to the needs of K-12. Our programs now include teacher training workshops, student science camps and curriculum projects in several states. We are reminded that K-12 science education is interdisciplinary; local and political; and a process, not a problem to be solved and forgotten. Partially supported by NSF (CHE-9876674 and DBI-0115462), the Howard Hughes Medical Institute and the Burroughs Wellcome Fund.

  20. Reflecting on Progress in K-12 Dance Education

    ERIC Educational Resources Information Center

    Callahan-Russell, Colleen

    2004-01-01

    Dance as an art form is transformational to body, mind, and spirit. The author opines that public education would do just fine if dance was the "only" subject taught. This article presents the author's reflection on progress of dance in K-12 education. The author contends that progress in dance in K-12 education can perhaps be judged by the fact…

  1. MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O.; Asimow, P.

    2013-06-01

    In a continuous effort to determine experimentally the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. The limit was primarily caused by intense sublimation of pure MgO in vacuum above ~2050 K. Completely redesigned Mo capsules holding ~20 mm long MgO crystals with controlled thermal gradients were impacted by thin Ta flyers launched at 6.5 to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel pyrometer with 3 ns time resolution, over 440-750 nm spectral range. All our experiments showed smooth pressure dependence of MgO sound speed consistent with the solid phase at 204-239 GPa. Observed temperatures are ~1000 K lower than those predicted by the solid phase model, but the plot of measured shock temperature versus pressure exhibits a pattern typical of shock melting at the highest pressure investigated. This may suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line at 220-240 GPa. Sound speed data indistinguishable from the solid phase model do not exclude the possibility of melting there.

  2. RXTE spectra of the Galactic microquasar GRO J1655-40 during the 2005 outburst

    NASA Astrophysics Data System (ADS)

    Saito, Koji; Yamaoka, K.; Fukuyama, M.; Miyakawa, T. G.; Yoshida, A.; Homan, J.

    We report on the results of a detailed spectral analysis of 389 RXTE observations of the Galac- tic microquasar GRO J1655-40, performed during its 2005 outburst. The maximum luminosity reached during this outburst was 1.4 times higher than in the previous (1996-1997) outburst. However, the spectral behavior during the two outbursts was very similar. In particular, L disk was 4 proportional to Tin up to the same critical luminosity and in both outbursts there were periods during which the energy spectra were very soft, but could not be fit with standard disk models.

  3. The evolution of metabolic networks of E. coli

    PubMed Central

    2011-01-01

    Background Despite the availability of numerous complete genome sequences from E. coli strains, published genome-scale metabolic models exist only for two commensal E. coli strains. These models have proven useful for many applications, such as engineering strains for desired product formation, and we sought to explore how constructing and evaluating additional metabolic models for E. coli strains could enhance these efforts. Results We used the genomic information from 16 E. coli strains to generate an E. coli pangenome metabolic network by evaluating their collective 76,990 ORFs. Each of these ORFs was assigned to one of 17,647 ortholog groups including ORFs associated with reactions in the most recent metabolic model for E. coli K-12. For orthologous groups that contain an ORF already represented in the MG1655 model, the gene to protein to reaction associations represented in this model could then be easily propagated to other E. coli strain models. All remaining orthologous groups were evaluated to see if new metabolic reactions could be added to generate a pangenome-scale metabolic model (iEco1712_pan). The pangenome model included reactions from a metabolic model update for E. coli K-12 MG1655 (iEco1339_MG1655) and enabled development of five additional strain-specific genome-scale metabolic models. These additional models include a second K-12 strain (iEco1335_W3110) and four pathogenic strains (two enterohemorrhagic E. coli O157:H7 and two uropathogens). When compared to the E. coli K-12 models, the metabolic models for the enterohemorrhagic (iEco1344_EDL933 and iEco1345_Sakai) and uropathogenic strains (iEco1288_CFT073 and iEco1301_UTI89) contained numerous lineage-specific gene and reaction differences. All six E. coli models were evaluated by comparing model predictions to carbon source utilization measurements under aerobic and anaerobic conditions, and to batch growth profiles in minimal media with 0.2% (w/v) glucose. An ancestral genome

  4. NSF GK-12 Fellows as Mentors for K-12 Teachers Participating in Field Research Experiences

    NASA Astrophysics Data System (ADS)

    Ellins, K.; Perry, E.

    2005-12-01

    The University of Texas Institute for Geophysics (UTIG) recognizes the value of providing educational opportunities to K-12 teachers who play a critical role in shaping the minds of young people who are the future of our science. To that end, UTIG established the "Texas Teachers in the Field" program in 2000 to formalize the participation of K-12 teachers in field programs that included UTIG scientists. In 2002, "Texas Teachers in the Field" evolved through UTIG's involvement in a University of Texas at Austin GK-12 project led by the Environmental Sciences Institute, which enabled UTIG to partner a subset of GK-12 Fellows with teachers participating in geophysical field programs. During the three years of the GK-12 project, UTIG successfully partnered four GK-12 Fellows with five K-12 teachers. The Fellows served as mentors to the teachers, as liaisons between UTIG scientists leading field programs and teachers and their students, and as resources in science, mathematics, and technology instruction. Specifically, Fellows prepared teachers and their students for the field investigations, supervised the design of individual Teacher Research Experience (TRE) projects, and helped teachers to develop standards-aligned curriculum resources related to the field program for use in their own classrooms, as well as broader distribution. Although all but one TRE occurred during the school year, Texas school districts and principals were willing to release teachers to participate because the experience and destinations were so extraordinary (i.e., a land-based program in Tierra del Fuego, Argentina; and research cruises to the Southeast Caribbean Sea and Hess Deep in the Pacific Ocean) and carried opportunities to work with scientists from around the world. This exceptional collaboration of GK-12 Fellows, K-12 teachers and research scientists enriches K-12 student learning and promotes greater enthusiasm for science. The level of mentoring, preparation and follow-up provided

  5. K-12 Teachers Encounter Digital Games: A Qualitative Investigation of Teachers' Perceptions of the Potential of Digital Games for K-12 Education

    ERIC Educational Resources Information Center

    Dickey, Michele D.

    2015-01-01

    The purpose of this study is to investigate teachers' perceptions of the integration of digital games for K-12 education. Specifically, this qualitative investigation focuses on reflective dialogued gathered from a group of K-12 educators about their experiences and perceptions of learning about and playing digital games for teaching and learning.…

  6. The impact of a 600-mg loading dose of clopidogrel in diabetic and non-diabetic patients undergoing elective PCI.

    PubMed

    Mohareb, Mina W; Abd Elghany, Mohamed; Sabry, Nirmeen A; Farid, Samar F

    2016-08-01

    High platelet reactivity (HPR) and suboptimal response to dual antiplatelet therapy (DAPT) may explain high recurrent rates of ischemic events in type 1 and 2 diabetes mellitus (DM) patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to determine the effect of diabetes mellitus on clopidogrel activity in cardiac patients undergoing PCI. This is an observational study. Patients were categorized according to DM status into diabetic group (N.=30) and non-diabetic group (N.=33). All patients received clopidogrel in a loading dose of 600 mg before PCI. Platelet function was assessed using light transmittance aggregometry (LTA) technique at baseline (before clopidogrel administration), 24 hour after clopidogrel loading dose administration and 7-10 days after PCI. All patients were followed up for at least one year after PCI for recurrence of acute cardiac events. There was no statistically significant difference between the two groups with respect to 10 µm adenosine diphosphate (ADP)-induced platelet aggregation measured at baseline (P=0.64), 24 hours after PCI (P=0.874), and 7-10 days after PCI (0.643). Diabetics were not significantly different from non-diabetics in terms of post-PCI acute stent thrombosis (P=0.945), sub-acute stent thrombosis (P=0.945), unstable angina (P=0.29) and cardiac death (P=0.64). There was a statistically significant difference between patients with and without post-PCI acute events regarding ADP aggregation measured 24 hours and 7-10 days after PCI. The use of a high loading dose of clopidogrel (600 mg) in patients undergoing elective PCI can overcome the significant increase in post-PCI platelet aggregation and rate of acute cardiac events induced by diabetes mellitus as co-morbidity in those patients.

  7. Information Infrastructure Technology and Applications (IITA) Program: Annual K-12 Workshop

    NASA Technical Reports Server (NTRS)

    Hunter, Paul; Likens, William; Leon, Mark

    1995-01-01

    The purpose of the K-12 workshop is to stimulate a cross pollination of inter-center activity and introduce the regional centers to curing edge K-1 activities. The format of the workshop consists of project presentations, working groups, and working group reports, all contained in a three day period. The agenda is aggressive and demanding. The K-12 Education Project is a multi-center activity managed by the Information Infrastructure Technology and Applications (IITA)/K-12 Project Office at the NASA Ames Research Center (ARC). this workshop is conducted in support of executing the K-12 Education element of the IITA Project The IITA/K-12 Project funds activities that use the National Information Infrastructure (NII) (e.g., the Internet) to foster reform and restructuring in mathematics, science, computing, engineering, and technical education.

  8. Heat capacities and entropies at 298.15 K of MgTiO3 (geikielite), ZnO (zincite), and ZnCO3 (smithsonite)

    USGS Publications Warehouse

    Robie, R.A.; Haselton, H.T.; Hemingway, B.S.

    1989-01-01

    Heat capacities of synthetic MgTiO3 (geikielite), ZnO (zincite), and natural crystals of smithsonite (ZnCO3) were measured between 9 and 366 K using an automatic adiabatically shielded calorimeter. At 298.15 K the standard molar entropies Smo of MgTiO3, ZnO, and ZnCO3 are (74.64 ?? 0.15), (43.16 ?? 0.09), and (81.19 ?? 0.16) J??K-1??mol-1, respectively. Debye temperatures for MgTiO3 and ZnO calculated from our Cp, mo values below 20 K are (900 ?? 20) K and (440 ?? 25) K respectively. Heat capacities for MgTiO3 and ZnO were combined with enthalpy increments from the literature to derive heat-capacity equations for these phases from 260 to about 1800 K. The heat capacities of MgTiO3 between 260 and 1720 K were fitted with an average deviation of 0.3 per cent by the equation: C??p,m/(J??K-1??mol-1) = 222.5-0.05274(T/K)-6.092x105(T/K)-1-1874.6(T/K) -1/2+1.878x10-5(T/K)2 and for ZnO the equation: C??p,m/(J??K-1??mol-1) = 53.999+7.851x10-4(T/K)-5.868x105(T/K)-2 -127.50(T/K)-:1/2+1.9376x10-6(T/K)2 fits the heat capacities in the temperature interval of 250 to 1800 K with an average deviation of 0.7 per cent. ?? 1989.

  9. Discovery of a Kojibiose Phosphorylase in Escherichia coli K-12.

    PubMed

    Mukherjee, Keya; Narindoshvili, Tamari; Raushel, Frank M

    2018-05-15

    The substrate profiles for three uncharacterized enzymes (YcjM, YcjT, and YcjU) that are expressed from a cluster of 12 genes ( ycjM-W and ompG) of unknown function in Escherichia coli K-12 were determined. Through a comprehensive bioinformatic and steady-state kinetic analysis, the catalytic function of YcjT was determined to be kojibiose phosphorylase. In the presence of saturating phosphate and kojibiose (α-(1,2)-d-glucose-d-glucose), this enzyme catalyzes the formation of d-glucose and β-d-glucose-1-phosphate ( k cat = 1.1 s -1 , K m = 1.05 mM, and k cat / K m = 1.12 × 10 3 M -1 s -1 ). Additionally, it was also shown that in the presence of β-d-glucose-1-phosphate, YcjT can catalyze the formation of other disaccharides using 1,5-anhydro-d-glucitol, l-sorbose, d-sorbitol, or l-iditol as a substitute for d-glucose. Kojibiose is a component of cell wall lipoteichoic acids in Gram-positive bacteria and is of interest as a potential low-calorie sweetener and prebiotic. YcjU was determined to be a β-phosphoglucomutase that catalyzes the isomerization of β-d-glucose-1-phosphate ( k cat = 21 s -1 , K m = 18 μM, and k cat / K m = 1.1 × 10 6 M -1 s -1 ) to d-glucose-6-phosphate. YcjU was also shown to exhibit catalytic activity with β-d-allose-1-phosphate, β-d-mannose-1-phosphate, and β-d-galactose-1-phosphate. YcjM catalyzes the phosphorolysis of α-(1,2)-d-glucose-d-glycerate with a k cat = 2.1 s -1 , K m = 69 μM, and k cat / K m = 3.1 × 10 4 M -1 s -1 .

  10. California's Future: K-12 Education

    ERIC Educational Resources Information Center

    Hill, Laura; Gao, Niu; Warren, Paul

    2015-01-01

    California educates more than six million children in its K-12 public schools. More than half of these children are economically disadvantaged, and almost a quarter are not native English speakers (compared to less than one in ten nationwide). California is working to address these challenges, in part by adopting a new, simplified school finance…

  11. Classifying K-12 Blended Learning

    ERIC Educational Resources Information Center

    Staker, Heather; Horn, Michael B.

    2012-01-01

    The growth of online learning in the K-12 sector is occurring both remotely through virtual schools and on campuses through blended learning. In emerging fields, definitions are important because they create a shared language that enables people to talk about the new phenomena. The blended-learning taxonomy and definitions presented in this paper…

  12. Interstellar Molecules in K-12 Education

    NASA Astrophysics Data System (ADS)

    Kuiper, T. B. H.; Hofstadter, M. D.; Levin, S. M.; MacLaren, D.

    2006-12-01

    The Lewis Center for Educational Research (LCER) and the Jet Propulsion Laboratory (JPL) collaborate in a K-12 educational project in which students conduct observations for several research programs led by radio astronomers. The Goldstone-Apple Valley Radio Telescope (GAVRT) program provides participating teachers with curriculum elements, based on the students' observing experiences, which support national and state academic standards. The current program is based on 2.2-GHz and 8.4-GHz radiometric observations of variable sources. The research programs monitor Jupiter, Uranus, and a selected set of quasars. The telescope is a decommissioned NASA Deep Space Network antenna at Goldstone, California. In the next three years, a second telescope will be added. This telescope will at least operate at the above frequencies as well as 6 GHz and 12 GHz. Possibly, it will operate in a continuous band from 1.2 GHz to 14 GHz. In either case, the telescope will be able to observe at least the 6.6-GHz and 12.2-GHz methanol maser lines. The success of the GAVRT program depends critically on the participation of scientists committed to the research who have the ability and enthusiasm for interacting with K-12 students, typically through teleconferences. The scientists will initially work with the LCER staff to create curriculum elements around their observing program.

  13. K-12 Technology Accessibility: The Message from State Governments

    ERIC Educational Resources Information Center

    Shaheen, Natalie L.; Lazar, Jonathan

    2018-01-01

    This study examined state education technology plans and technology accessibility statutes to attempt to answer the question--is K-12 instructional technology accessibility discussed in state-level technology accessibility statutes and education technology plans across the 50 United States? When a K-12 school district is planning the construction…

  14. Educating K-12 Students about Glacier Dynamics in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Stearns, L. A.; Hamilton, G. S.

    2005-12-01

    Public awareness of climate change is growing in the United States. Popular movies, books and magazines are frequently addressing the issue of global warming - some with careful scientific research, but many with unrealistic statements. Early education about the basic principles and processes of climate change is necessary for the general public to distinguish fact from fiction. The U.S. National Science Foundation's GK-12 program (GK-12; grades K to 12) currently in its sixth year, provides an opportunity for scientific enrichment for students and their teachers at the K-12 level through collaborative pairings with science and engineering graduate students (the Fellows). The NSF GK-12 program at the University of Maine has three goals: to enrich the scientific education of the students by providing role models, expertise, and equipment that may not be accessible otherwise; to provide professional development for the teachers through curriculum enrichment and participation at science conferences; and to improve the teaching and communication skills of the Fellows. The University of Maine is one of over 100 U. S. universities participating in this program. During the 2004-05 academic year, 11 graduate and one undergraduate student Fellows, advised by University faculty members, taught at schools across the state of Maine. Fellows from, biology, earth science, ecology, engineering, food science, forestry, and marine science, and taught in their area of expertise. We created a hands-on activity for middle and high school students that describes glacier mass balance in a changing climate. The students make a glacier using glue, water and detergent ('flubber') and construct a glacier valley using plastic sheeting. Flubber behaves in mechanically similar ways to glacier ice, undergoing plastic deformation at low stresses and exhibiting brittle failure at high stresses. Students are encouraged to run several tests with different values for valley slope, glacier mass

  15. [Synthesis of vitamin K2 by isopentenyl transferase NovA in Pichia pastoris Gpn12].

    PubMed

    Wu, Xihua; Li, Zhemin; Liu, Hui; Wang, Peng; Wang, Li; Fang, Xue; Sun, Xiaowen; Ni, Wenfeng; Yang, Qiang; Zheng, Zhiming; Zhao, Genhai

    2018-01-25

    The effect of methanol addition on the heterologous expression of isoprenyl transferase NovQ was studied in Pichia pastoris Gpn12, with menadione and isopentenol as precursors to catalyze vitamin K2 (MK-3) synthesis. The expression of NovQ increased by 36% when 2% methanol was added every 24 h. The influence of initial pH, temperature, methanol addition, precursors (menadione, isopentenol) addition, catalytic time and cetyltrimethyl-ammonium bromide (CTAB) addition were explored in the P. pastoris whole-cell catalytic synthesis process of MK-3 in shaking flask. Three significant factors were then studied by response surface method. The optimal catalytic conditions obtained were as follows: catalytic temperature 31.56 ℃, menadione 295.54 mg/L, catalytic time 15.87 h. Consistent with the response surface prediction results, the optimized yield of MK-3 reached 98.47 mg/L in shaking flask, 35% higher than that of the control group. On this basis, the production in a 30-L fermenter reached 189.67 mg/L when the cell catalyst of 220 g/L (dry weight) was used to catalyze the synthesis for 24 h. This method laid the foundation for the large-scale production of MK-3 by P. pastoris Gpn12.

  16. K-12 Science Curriculum Guide.

    ERIC Educational Resources Information Center

    Reading Community Schools, OH.

    GRADES OR AGES: K-12. SUBJECT MATTER: Science. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into three sections, one each for elementary grades, middle grades, and high school. The first two sections are further subdivided by grade level and the last section is subdivided by course. Sections are laid out in four columns across two…

  17. Hydrogen storage and phase transformations in Mg-Pd nanoparticles

    NASA Astrophysics Data System (ADS)

    Callini, E.; Pasquini, L.; Rude, L. H.; Nielsen, T. K.; Jensen, T. R.; Bonetti, E.

    2010-10-01

    Microstructure refinement and synergic coupling among different phases are currently explored strategies to improve the hydrogen storage properties of traditional materials. In this work, we apply a combination of these methods and synthesize Mg-Pd composite nanoparticles by inert gas condensation of Mg vapors followed by vacuum evaporation of Pd clusters. Irreversible formation of the Mg6Pd intermetallic phase takes place upon vacuum annealing, resulting in Mg/Mg6Pd composite nanoparticles. Their hydrogen storage properties are investigated and connected to the undergoing phase transformations by gas-volumetric techniques and in situ synchrotron radiation powder x-ray diffraction. Mg6Pd transforms reversibly into different Mg-Pd intermetallic compounds upon hydrogen absorption, depending on temperature and pressure. In particular, at 573 K and 1 MPa hydrogen pressure, the metal-hydride transition leads to the formation of Mg3Pd and Mg5Pd2 phases. By increasing the pressure to 5 MPa, the Pd-richer MgPd intermetallic is obtained. Upon hydrogen desorption, the Mg6Pd phase is reversibly recovered. These phase transformations result in a specific hydrogen storage capacity associated with Mg-Pd intermetallics, which attain the maximum value of 3.96 wt % for MgPd and influence both the thermodynamics and kinetics of hydrogen sorption in the composite nanoparticles.

  18. Engineering a synthetic pathway in cyanobacteria for isopropanol production directly from carbon dioxide and light.

    PubMed

    Kusakabe, Tamami; Tatsuke, Tsuneyuki; Tsuruno, Keigo; Hirokawa, Yasutaka; Atsumi, Shota; Liao, James C; Hanai, Taizo

    2013-11-01

    Production of alternate fuels or chemicals directly from solar energy and carbon dioxide using engineered cyanobacteria is an attractive method to reduce petroleum dependency and minimize carbon emissions. Here, we constructed a synthetic pathway composed of acetyl-CoA acetyl transferase (encoded by thl), acetoacetyl-CoA transferase (encoded by atoAD), acetoacetate decarboxylase (encoded by adc) and secondary alcohol dehydrogenase (encoded by adh) in Synechococcus elongatus strain PCC 7942 to produce isopropanol. The enzyme-coding genes, heterogeneously originating from Clostridium acetobutylicum ATCC 824 (thl and adc), Escherichia coli K-12 MG1655 (atoAD) and Clostridium beijerinckii (adh), were integrated into the S. elongatus genome. Under the optimized production conditions, the engineered cyanobacteria produced 26.5 mg/L of isopropanol after 9 days. © 2013 Published by Elsevier Inc.

  19. Plastic deformation of polycrystalline MgO up to 1250 K and 65 GPa

    NASA Astrophysics Data System (ADS)

    Merkel, S.; Liermann, H.; Miyagi, L. M.; Wenk, H.

    2009-12-01

    Understanding the development of lattice preferred orientations (LPO) in polycrystals is critical to constrain the anisotropy and dynamics of the Earth mantle. Until recently, it was not possible to study LPO under high pressure and high temperature. The introduction of the deformation-DIA (D-DIA) and radial diffraction experiments in the diamond anvil cell (DAC) have extended the range of pressures and temperatures that can be accessed. However, the pressure range accessible in the D-DIA remains limited (up to 19 GPa, 1) and LPO measurements in the DAC have been performed at 300 K (2). Recently, we have designed a new DAC that can be used to study LPO in polycrystalline samples up to temperatures of 1300 K and pressures of 65 GPa (3). In this study, we use this new device for the study of MgO up to 65 GPa and 1250 K. Four samples of polycrystalline MgO were deformed in the DAC at constant temperature: 300, 600, 900, and 1250 K. At each temperature, we study the development of stress and LPO as the sample is compressed between ambient and high pressures (up to 65 GPa). In all cases, we collect diffraction data in a radial geometry that can be used to extract lattice strains and LPO in the sample. A comparison of the LPO measured in the experiment and results of visco-plastic self-consistent models can be used to extract information about the active deformation mechanisms in the sample (2). Similarly, the measured lattice strains can be compared to results of an elasto-plastic self-consistent model to extract information on average stress, stress distribution among grains, and active deformation in the sample (4). Details of the measurements along with the LPO measured in the experiments will be presented. We will also discuss the implication of those results for our understanding of the behavior of MgO in the deep mantle. 1- N. Nishiyama, Y. Wang, M. L. Rivers, S. R. Sutton, D. Cookson, Rheology of e-iron up to 19 GPa and 600 K in the D-DIA, Geophys. Res. Lett., 34

  20. Increased oxidative stress and decreased activities of Ca2+/Mg2+-ATPase and Na+/K+-ATPase in the red blood cells of the hibernating black bear

    USGS Publications Warehouse

    Chauhan, V.P.S.; Tsiouris, J.A.; Chauhan, A.; Sheikh, A.M.; Brown, W. Ted; Vaughan, M.

    2002-01-01

    During hibernation, animals undergo metabolic changes that result in reduced utilization of glucose and oxygen. Fat is known to be the preferential source of energy for hibernating animals. Malonyldialdehyde (MDA) is an end product of fatty acid oxidation, and is generally used as an index of lipid peroxidation. We report here that peroxidation of lipids is increased in the plasma and in the membranes of red blood cells in black bears during hibernation. The plasma MDA content was about four fold higher during hibernation as compared to that during the active, non-hibernating state (P < 0.0001). Similarly, MDA content of erythrocyte membranes was significantly increased during hibernation (P < 0.025). The activity of Ca2+/Mg2+-ATPase in the erythrocyte membrane was significantly decreased in the hibernating state as compared to the active state. Na+/K+-ATPase activity was also decreased, though not significant, during hibernation. These results suggest that during hibernation, the bears are under increased oxidative stress, and have reduced activities of membrane-bound enzymes such as Ca2+/Mg2+-ATPase and Na+/K+-ATPase. These changes can be considered part of the adaptive for survival process of metabolic depression. ?? 2002 Elsevier Science Inc. All rights reserved.

  1. Comparative evaluation of some commercially available brands of pharmaceutical preparations for Na, K and Mg concentrations.

    PubMed

    Hayat, Sikander; Chughtai, Muhammad Ismail; Ansari, Tariq Mahmood; Kamal, Ghulam Mustafa

    2012-04-01

    A study was carried out to investigate the concentrations of macro-elements (Na(+), K(+) and Mg(+2)) in twelve commercially available pharmaceutical preparations used as sex stimulant, by Atomic Absorption Spectrophotometer. A wet digestion method was adopted to prepare the samples. The results indicated that sodium concentration was maximum (3702 ± 29 μg g(-1)) in LB and minimum (495 ± 06 μg g(-1)) in H-E-H. Potassium concentration was maximum (6337 ± 13 μg g(-1)) in NBA while minimum (150 ± 06 μg g(-1)) in ZGRA. Magnesium concentration was maximum in V-100 (9226 ± 11 μg g(-1)) and minimum in FGRA (1194 ± 25 μg g(-1)). The concentration of macro-elements in the imported herbal preparations was in the order of Mg and in the local herbal preparations as follows: Mg

  2. Developing Open Education Literacies with Practicing K-12 Teachers

    ERIC Educational Resources Information Center

    Kimmons, Royce M.

    2014-01-01

    This study seeks to understand how to use formal learning activities to effectively support the development of open education literacies among K-12 teachers. Considering pre-and post-surveys from K-12 teachers (n = 80) who participated in a three-day institute, this study considers whether participants entered institutes with false confidence or…

  3. Soil Science Society of America - K-12 Outreach

    NASA Astrophysics Data System (ADS)

    Lindbo, David L.; Loynachan, Tom; Mblia, Monday; Robinson, Clay; Chapman, Susan

    2013-04-01

    The Soil Science Society of America created its K12 Committee in 2006 in part to compliment the Dig It! The Secrets of Soil exhibit that opened in July 2008 at the Smithsonian's Institution's Nation Museum of Natural History (of which SSS was a founding sponsor). The committee's work began quickly with a website designed to provide resources for K12 teachers. The first accomplishments included reviewing and posting links to web based information already available to teachers. These links were sorted by subject and grade level to make it easier for teachers to navigate the web and find what they needed quickly. Several presentations and lessons designed for K12 teachers were also posted at this time. Concurrent with this effort a subcommittee review and organized the national teaching standards to show where soils could fit into the overall K12 curriculum. As the website was being developed another subcommittee developed a soils book (Soil! Get the Inside Scoop, 2008) to further compliment the Dig It! exhibit. This was a new endeavor for SSSA having never worked with the non-academic audience in developing a book. Peer-reviews of this book included not only scientist but also students in order to make sure the book was attractive to them. Once the book was published and the website developed it became clear more outreach was needed. SSSA K12 Committee has attended both the National Science Teachers Association (since 2008) the USA Science and Engineering Festival (since 2010) with exhibits and workshops. It has cooperated and contributed to the American Geologic Institutes' Earth Science Week materials with brochures and lesson plans and with National Association of Conservation Districts by providing peer-review and distribution of materials. The most recent developments from the committee include a web redesign that is more student and teacher friendly, the development of a peer-review system to publish K12 Lesson Plans, and finally the publication of a new soils

  4. Unified Science Approach K-12, Proficiency Levels 7-12.

    ERIC Educational Resources Information Center

    Oickle, Eileen M., Ed.

    Presented is the second part of the K-12 unified science materials used in the public schools of Anne Arundel County, Maryland. Detailed descriptions are made of the roles of students and teachers, purposes of the bibliography, major concepts in unified science, processes of inquiry, a scheme and model for scientific literacy, and program…

  5. Low Z elements (Mg, Al, and Si) K-edge X-ray absorption spectroscopy in minerals and disordered systems

    NASA Astrophysics Data System (ADS)

    Ildefonse, Ph.; Calas, G.; Flank, A. M.; Lagarde, P.

    1995-05-01

    Soft X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy have been performed at the Mg-, Al- and Si-K edges in order to establish the ability of this spectroscopy to derive structural information in disordered solids such as glasses and gels. Mg- and Al-K XANES are good structural probes to determine the coordination state of these elements in important minerals, glasses and gels. In a CaOsbnd MgOsbnd 2SiO2 glass Mg XANES spectra differ from that found in the crystalline equivalent, with a significant shift of the edge maxima to lower energy, consistent with a CN lower than 6. Mg-EXAFS on the same sample are in agreement and indicate the presence of 5-coordinated Mg with Mgsbnd O distances of 2.01Å. In aluminosilicate gels, Alsbnd K XANES has been used to investigate the [4]Al/Altotal ratios. These ratios increase as the Al/Si ratios decrease. Aluminosilicate and ferric-silicate gels were studied by using Sisbnd K edge XANES. XANES spectra differ significantly among the samples studied. Aluminosilicate gels with Al/Si= 1 present a different Al and Si local environment from that known in clay minerals with the same Al/Si ratio. The gel-to-mineral transformation thus implies a dissolution-recrystallization mechanism. On the contrary, ferric-silicate gel presents a Si local environment close to that found in nontronite which may be formed by a long range ordering of the initial gels.

  6. Effects of NH4+, K+, Mg2+, and Ca2+ on the Cesium Adsorption/Desorption in Binding Sites of Vermiculitized Biotite.

    PubMed

    Yin, Xiangbiao; Wang, Xinpeng; Wu, Hao; Takahashi, Hideharu; Inaba, Yusuke; Ohnuki, Toshihiko; Takeshita, Kenji

    2017-12-05

    The reversibility of cesium adsorption in contaminated soil is largely dependent on its interaction with micaceous minerals, which may be greatly influenced by various cations. Herein, we systematically investigated the effects of NH 4 + , K + , Mg 2+ , and Ca 2+ on the adsorption/desorption of Cs + into different binding sites of vermiculitized biotite (VB). Original VB was initially saturated by NH 4 + , K + , or Mg 2+ ; we then evaluated the adsorption of Cs + on three treated VBs, and the desorption by extraction with NH 4 + , K + , Mg 2+ , or Ca 2+ was further evaluated. Our structural analysis and Cs + extractability determinations showed that NH 4 + and K + both collapsed the interlayers of VB, resulting in the dominant adsorption of Cs + to external surface sites on which Cs + was readily extracted by NH 4 + , K + , Mg 2+ , or Ca 2+ irrespective of their species, whereas Mg 2+ maintained the VB with expanded interlayers, leading to the overwhelming adsorption of Cs + in collapsed interlayer sites on which the Cs + desorption was difficult and varied significantly by the cations used in extraction. The order of Cs + extraction ability from the collapsed interlayers was K + ≫ Mg 2+ ≈ Ca 2+ ≫ NH 4 + . These results could provide important insights into Cs migration in soil and its decontamination for soil remediation.

  7. Harnessing Technology to Improve K-12 Education. Discussion Paper 2012-05

    ERIC Educational Resources Information Center

    Chatterji, Aaron; Jones, Benjamin

    2012-01-01

    Technological progress has consistently driven remarkable advances in the U.S. economy, yet K-12 education sees little technological change compared to other sectors, even as U.S. K-12 students increasingly lag behind students in other nations. This proposal considers how we can take a signature American strength--innovation--and apply it to K-12…

  8. The system K2Mg2(SO4)3 (langbeinite)-K2Ca2(SO4)3 (calcium-langbeinite)

    USGS Publications Warehouse

    Morey, G.W.; Rowe, J.J.; Fournier, R.O.

    1964-01-01

    The join between the compositions K2Mg2(SO4)3 and K2Ca2(SO4)3 was studied by means of high-temperature equilibrium quenching techniques and by means of a heating stage mounted on an X-ray diffractometer. Complete solid solution exists in the system, but at 25??C members of the solid solution series are isometric only in the composition range 0-73??5 wt. per cent K2Ca2(SO4)3. At compositions richer in K2Ca2(SO4)3 than 73??5 wt. per cent, members of the series are optically biaxial. At higher temperatures members of the solid solution series are isometric at successively more calcium-rich compositions and pure K2Ca2(SO4)3 is isometric above about 200 ?? 2??C. The system is not binary, as mixtures richer in K2Ca2(SO4)3 than 42 wt. per cent decompose with the formation of liquid and CaSO4. ?? 1964.

  9. Renal insufficiency predicts mortality in geriatric patients undergoing emergent general surgery.

    PubMed

    Yaghoubian, Arezou; Ge, Phillip; Tolan, Amy; Saltmarsh, Guy; Kaji, Amy H; Neville, Angela L; Bricker, Scott; De Virgilio, Christian

    2011-10-01

    Clinical predictors of perioperative mortality in geriatric patients undergoing emergent general surgery have not been well described. The purpose of this study was to determine the incidence of postoperative morbidity and mortality in geriatric patients and factors associated with mortality. A retrospective review of patients 65 years of age or older undergoing emergent general surgery at a public teaching hospital was performed over a 7-year period. Data collected included demographics, comorbidities, laboratory studies, perioperative morbidities, and mortality. Descriptive statistics and predictors of morbidity and mortality are described. The mean age was 74 years. Indications for surgery included small bowel obstruction (24%), diverticulitis (20%), perforated viscous (16%), and large bowel obstruction (9%). The overall complication rate was 41 per cent with six cardiac complications (14%) and seven perioperative (16%) deaths. Mean admission serum creatinine was significantly higher in patients who died (3.6 vs 1.5 mg/dL, P = 0.004). Mortality for patients with an admission serum creatinine greater than 2.0 mg/dL was 42 per cent (5 of 12) compared with 3 per cent (2 of 32) for those 2.0 mg/dL or less (OR, 10.7; CI, 1.7 to 67; P = 0.01). Morbidity and mortality in geriatric patients undergoing emergency surgery remains high with the most significant predictor of mortality being the presence of renal insufficiency on admission.

  10. Bioequivalence studies for 2 different strengths of irbesartan/hydrochlorothiazide combination in healthy volunteers: 300/25 mg and 300/12.5 mg film-coated tablets.

    PubMed

    Cánovas, M; Cabré, F; Polonio, F

    2014-05-01

    Two bioequivalence studies of irbesartan (CAS 138402-11-6) and hydrochlorothiazide (CAS 58-93-5) combination at 300/12.5 mg and 300/25 mg strengths were carried out in order to assess the bioequivalence of these film-coated tablet formulations in comparison with the marketed reference formulations.Both studies were performed with 30 healthy volunteers according to an open label, randomized, 2-period, 2-sequence, crossover, single dose and fasting conditions design. In each study, test and reference formulations were administered in 2 treatment days, separated by a washout period of 7 days. Blood samples were drawn up to 72 h following drug administration in case of irbesartan and up to 24 h in case of hydrochlorothiazide. Plasma concentrations of both analytes were obtained by a validated HPLC method using MS/MS detection. Log-transformed AUC0-t and Cmax values were tested for bioequivalence based on the ratios of the geometric LSmeans (test/reference).For both studies, the 90% confidence intervals of the geometric LSmean values for the test/reference ratios for AUC0-t [(irbesartan: 300/12.5 mgstrength: 95.33-111.74%. 300/25 mg strength: 91.27-103.93%) (hydrochlorothiazide: 300/12.5 mg strength: 99.63-107.50%. 300/25 mg strength: 95.72-102.24%)] and Cmax [(irbesartan: 300/12.5 mg strength: 98.73-115.03%. 300/25 mg strength: 97.27-112.12%) (hydrochlorothiazide: 300/12.5 mg strength: 97.34-112.06%. 300/25 mg strength: 93.29-106.38%)] were within the bio-equivalence acceptance range of 80-125%.According to the European Guideline on the Investigation of Bioequivalence it may be therefore concluded that both test formulations are bioequivalent to the corresponding reference formulations. Overall, it was judged that both studies were conducted with a good tolerance of the subjects to study drugs. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Earth Science Content Guidelines Grades K-12.

    ERIC Educational Resources Information Center

    American Geological Inst., Alexandria, VA.

    Teams of teachers, other science educators, and scientists selected from a national search for project writers have proposed using the following set of questions to guide the inclusion of earth science content into the kindergarten through grade 12 curriculum. The Essential Questions are organized in a K-12 sequence by six content areas: (1) Solid…

  12. DIFFUSION OF MAGNESIUM AND MICROSTRUCTURES IN Mg+ IMPLANTED SILICON CARBIDE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jiang, Weilin; Edwards, Danny J.; Jung, Hee Joon

    2014-08-28

    Following our previous reports [ 1- 3], further isochronal annealing (2 hrs.) of the monocrystalline 6H-SiC and polycrystalline CVD 3C-SiC was performed at 1573 and 1673 K in Ar environment. SIMS data indicate that observable Mg diffusion in 6H-SiC starts and a more rapid diffusion in CVD 3C-SiC occurs at 1573 K. The implanted Mg atoms tend to diffuse deeper into the undamaged CVD 3C-SiC. The microstructure with Mg inclusions in the as-implanted SiC has been initially examined using high-resolution STEM. The presence of Mg in the TEM specimen has been confirmed based on EDS mapping. Additional monocrystalline 3C-SiC samplesmore » have been implanted at 673 K to ion fluence 3 times higher than the previous one. RBS/C analysis has been performed before and after thermal annealing at 1573 K for 12 hrs. Isothermal annealing at 1573 K is being carried out and Mg depth profiles being measured. Microstructures in both the as-implanted and annealed samples are also being examined using STEM.« less

  13. Scientific and Engineering Practices in K-12 Classrooms: Understanding "A Framework for K-12 Science Education"

    ERIC Educational Resources Information Center

    Bybee, Rodger W.

    2011-01-01

    In this article, the author presents the science and engineering practices from the recently released "A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas" (NRC 2011). The author recognizes the changes implied by the new framework, and eventually a new generation of science education standards will present new…

  14. CLASP2: High-Precision Spectro-Polarimetery in Mg II h & k

    NASA Technical Reports Server (NTRS)

    Ishikawa, R.; McKenzie, D.; Trujillo Bueno, J.; Auchere, F.; Rachmeler, L.; Okamoto, T. J.; Kano, R.; Song, D.; Kubo, M.; Narukage, N.; hide

    2017-01-01

    The international team is promoting the CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket experiment, which is the re-flight of CLASP (2015). In this second flight, we will refit the existing CLASP instrument to measure all Stokes parameters in Mg II h k lines, and aim at inferring the magnetic field information in the upper chromosphere combining the Hanle and Zeeman effects. CLASP2 project was approved by NASA in December 2016, and is now scheduled to fly in 2019.

  15. Optical and thermodynamic properties of MgO from radiative shock temperature and sound speed measurements on samples preheated to 2300 K

    NASA Astrophysics Data System (ADS)

    Fatýanov, O. V.; Asimow, P. D.

    2013-12-01

    Thermodynamic properties of MgO, one of the major end-members of deep planetary interiors, play a significant role in the processes inside the Earth's lower mantle. Of particular importance in geophysics and geochemistry is the MgO melting behavior at high pressure. Despite considerable theoretical and experimental efforts over decades, it remains essentially unknown. The melting temperature predictions for MgO at 135 GPa, the Earth's core-mantle boundary pressure, range from 5 to 9 kK. In a continuous effort to resolve this inconsistency and to probe the P-T region previously unexplored, we developed a technique for radiative shock temperature measurements in single-crystal MgO preheated to 2300 K. Large ventilated Mo capsules were employed to hold ~20 mm long MgO crystals with controlled longitudinal thermal gradients. These hot targets were impacted by 0.8 mm thick Ta flyers launched at 6.5 to 7.5 km/s on the Caltech two-stage light-gas gun. Six spectral radiance histories from MgO shock front were recorded in every shot with 3 ns time resolution over 440-750 nm or 500-830 nm spectral range. The majority of our experiments showed smooth pressure dependence of MgO shock temperature and sound speed consistent with the solid phase at 197-243 GPa. Although most observed temperatures are ~700 K lower and sound speeds ~1 km/s higher than the model predictions, the pressure slopes for both parameters are in close agreement with those calculated for the solid phase. Unconfirmed data from a single experiment at 239 GPa and 8.3 kK showed correlated temperature and sound speed anomalies (both values lower than expected) that may be explained by partial melting. Our past and recent data on shock-compressed preheated MgO suggest its melting curve above 200 GPa is higher than the extrapolation of the experiments of Zerr & Boehler or the theoretical calculation by Strachan et. al. These results, features of shock experiments with 2300 K pre-heat temperatures, data analysis

  16. Study of Np(V) Sorption by Ionic Exchange on Na, K, Ca and Mg-Montmorillonite

    NASA Astrophysics Data System (ADS)

    Benedicto, A.; Begg, J.; Zhao, P.; Kersting, A. B.; Zavarin, M.

    2012-12-01

    The transport behavior of actinides in soil and ground water are highly influenced by clay minerals due to their ubiquity in the environment, reactivity and colloidal properties. Neptunium(V) has been introduced in the environment as a result of nuclear weapons testing [e.g. 1, 2] and is a radionuclide of potential interest for safety assessment of high level radioactive waste disposal because its long half-life and high toxicity [3]. Surface complexation and ionic exchange have been identified as Np(V) sorption mechanisms onto montmorillonite. At pH below 5, Np(V) sorption is mainly attributed to ionic exchange. This study examines Np(V) ion exchange on Na, K, Ca and Mg forms of montmorillonite. Experiments were carried out using 237Np concentrations between 2 x 10-8 M and 5 x 10-6 M at three different ionic strengths 0.1, 0.01 and 0.001M. The pH was maintained at 4.5. Np(V) sorption to montmorillonite homoionized with monovalent cations (Na and K) demonstrated a markedly different behavior to that observed for montmorillonite homoionized with divalent cations (Ca and Mg). Np sorption to Na and K-montmorillonite was greater than Np sorption to Ca and Mg-montmorillonite. Isotherms with Na and K-montmorillonite showed a strong dependence on ionic strength: the percentage of Np adsorbed was near zero at 0.1M ionic strength, but increased to 30% at 0.001 M ionic strength. This suggests ionic exchange is the main Np adsorption mechanism under the experimental conditions investigated. Dependence on ionic strength was not observed in the Np sorption isotherms for Ca and Mg-montmorillonite indicating a low exchange capacity between Np and divalent cations. Modeling of the sorption experimental data will allow determination of the Na+↔NpO2+ and K+↔NpO2+ ionic exchange constants on montmorillonite. References: [1] A. R. Felmy; K. J. Cantrell; S. D. Conradson, Phys. Chem. Earth 2010, 35, 292-297 [2] D. K. Smith; D. L. Finnegan; S. M. Bowen, J. Environ. Radioact. 2003, 67

  17. Revolutionizing Arts Education in K-12 Classrooms through Technological Integration

    ERIC Educational Resources Information Center

    Lemon, Narelle, Ed.

    2015-01-01

    Educational technologies are becoming more commonplace across the K-12 curriculum. In particular, the use of innovative digital technology is expanding the potential of arts education, presenting new opportunities--and challenges--to both curricular design and pedagogical practice. "Revolutionizing Arts Education in K-12 Classrooms through…

  18. High-performance MgB2 superconducting wires for use under liquid-helium-free conditions fabricated using an internal Mg diffusion process

    NASA Astrophysics Data System (ADS)

    Ye, ShuJun; Song, Minghui; Matsumoto, Akiyoshi; Togano, Kazumasa; Takeguchi, Masaki; Ohmura, Takahito; Kumakura, Hiroaki

    2013-12-01

    MgB2 has a superconducting transition temperature (Tc) of 39 K, which is much higher than that for practical metallic superconductors. Thus, it is hoped that MgB2 can not only replace metallic superconductors, but can be used under liquid-helium-free conditions, for example, at temperatures of 10-20 K that can easily be achieved using cryocooling systems. However, to date, the reported critical current density (Jc) for MgB2 wires is not high enough for large-scale applications in liquid-helium-free conditions. In the present study, successful fabrication of high-performance MgB2 superconducting wires was carried out using an internal Mg diffusion (IMD) process, involving a p-dimethylbenzene (C8H10) pre-treatment of carbon-coated B powder with nanometer-sized particles. The resulting wires exhibited the highest ever Jc of 1.2 × 105 A cm-2 at 4.2 K and 10 T, and an engineering critical current density (Je) of about 1 × 104 A cm-2. Not only in 4.2 K, but also in 10 K, the Jc values for the wires fabricated in the present study are in fact higher than that for Nb-Ti wires at 4.2 K for the magnetic fields at which the measurements were carried out. At 20 K and 5 T, the Jc and Je were about 7.6 × 105 A cm-2 and 5.3 × 103 A cm-2, respectively, which are the highest values reported for MgB2 wires to date. The results of a detailed microstructural analysis suggested that the main reason for the superior electrical performance was the high density of the MgB2 layer rather than just the small grain size, and that the critical current could be further increased by suitable control of the microstructure. These high-performance IMD-processed MgB2 wires are thus promising superconductors for applications such as magnetic resonance imaging and maglev trains that can operate under liquid-helium-free conditions.

  19. Safety and tolerability of bilastine 10 mg administered for 12 weeks in children with allergic diseases.

    PubMed

    Novák, Zoltán; Yáñez, Anahí; Kiss, Ildikó; Kuna, Piotr; Tortajada-Girbés, Miguel; Valiente, Román

    2016-08-01

    Regulations on medicinal products for paediatric use require that pharmacokinetics and safety be characterized specifically in the paediatric population. A previous study established that a 10-mg dose of bilastine in children aged 2 to <12 years provided an equivalent systemic exposure as 20 mg in adults. The current study assessed the safety and tolerability of bilastine 10 mg in children with allergic rhinoconjunctivitis and chronic urticaria. In this phase III, multicentre, double-blind study, children were randomized to once-daily treatment with bilastine 10-mg oral dispersible table (n = 260) or placebo (n = 249) for 12 weeks. Safety evaluations included treatment-emergent adverse events (TEAEs), laboratory tests, cardiac safety (ECG recordings) and somnolence/sedation using the Pediatric Sleep Questionnaire (PSQ). The primary hypothesis of non-inferiority between bilastine 10 mg and placebo was demonstrated on the basis of a near-equivalent proportion of children in each treatment arm without TEAEs during 12 weeks' treatment (31.5 vs. 32.5%). No clinically relevant differences between bilastine 10 mg and placebo were observed from baseline to study end for TEAEs or related TEAEs, ECG parameters and PSQ scores. The majority of TEAEs were mild or moderate in intensity. TEAEs led to discontinuation of two patients treated with bilastine 10 mg and one patient treated with placebo. Bilastine 10 mg had a safety and tolerability profile similar to that of placebo in children aged 2 to <12 years with allergic rhinoconjunctivitis or chronic urticaria. © 2016 The Authors. Pediatric Allergy and Immunology Published by John Wiley & Sons Ltd.

  20. DFT and TD-DFT study of the adsorption and detection of sulfur mustard chemical warfare agent by the C24, C12Si12, Al12N12, Al12P12, Be12O12, B12N12 and Mg12O12 nanocages

    NASA Astrophysics Data System (ADS)

    Jouypazadeh, Hamidreza; Farrokhpour, Hossein

    2018-07-01

    In the present research, the interaction of sulfur mustard, a chemical warfare agent, with the surface of C24, C12Si12, Al12N12, Al12P12, Be12O12, B12N12 and Mg12O12 nanocages was studied using the dispersion corrected density function theory (DFT-D3) method. The calculated adsorption energies of sulfur mustard on the surface of the nanocages showed that the Al12N12, C12Si12 and Mg12O12 are useful for the adsorption of the sulfur mustard. The quantum theory atom in molecule (QTAIM) analysis was used to study the nature of interactions of sulfur mustard with the surface of the selected nanocages. Based on QTAIM analysis, the majority of interactions of sulfur and chlorine atoms of sulfur mustard with the surface of the considered nanocages are covalent and quasi covalent whereas the interactions of hydrogen atoms of sulfur mustard with the surface of the nanocages are generally non-covalent. The charge transfer between sulfur mustard and the nanocages as well as chemical quantum descriptors of complexes were calculated using natural bond orbital (NBO) method. The most electron charge transfers from the sulfur mustard to B12N12 nanocage where the S atom of sulfur mustard donor a chemical bond to B atom of the nanocage. The ability of the considered nanocages for detecting sulfur mustard was studied using time-dependent density function theory (TD-DFT) and density of state (DOS) diagram. It is found that the C24, Al12P12, Be12O12 and B12N12 nanocages are useful sensors for this chemical agent.

  1. 12 CFR 211.11 - Advisory opinions under Regulation K.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 2 2013-01-01 2013-01-01 false Advisory opinions under Regulation K. 211.11... INTERNATIONAL BANKING OPERATIONS (REGULATION K) International Operations of U.S. Banking Organizations § 211.11 Advisory opinions under Regulation K. (a) Request for advisory opinion. Any person may submit a request to...

  2. 12 CFR 211.11 - Advisory opinions under Regulation K.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Advisory opinions under Regulation K. 211.11... INTERNATIONAL BANKING OPERATIONS (REGULATION K) International Operations of U.S. Banking Organizations § 211.11 Advisory opinions under Regulation K. (a) Request for advisory opinion. Any person may submit a request to...

  3. 12 CFR 211.11 - Advisory opinions under Regulation K.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 2 2014-01-01 2014-01-01 false Advisory opinions under Regulation K. 211.11... INTERNATIONAL BANKING OPERATIONS (REGULATION K) International Operations of U.S. Banking Organizations § 211.11 Advisory opinions under Regulation K. (a) Request for advisory opinion. Any person may submit a request to...

  4. 12 CFR 211.11 - Advisory opinions under Regulation K.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 2 2011-01-01 2011-01-01 false Advisory opinions under Regulation K. 211.11... INTERNATIONAL BANKING OPERATIONS (REGULATION K) International Operations of U.S. Banking Organizations § 211.11 Advisory opinions under Regulation K. (a) Request for advisory opinion. Any person may submit a request to...

  5. 12 CFR 211.11 - Advisory opinions under Regulation K.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 2 2012-01-01 2012-01-01 false Advisory opinions under Regulation K. 211.11... INTERNATIONAL BANKING OPERATIONS (REGULATION K) International Operations of U.S. Banking Organizations § 211.11 Advisory opinions under Regulation K. (a) Request for advisory opinion. Any person may submit a request to...

  6. Interaction between a Mg17Al12 precipitate and { 10\\bar 12} < 10\\bar 12 > twin boundary in magnesium alloys

    NASA Astrophysics Data System (ADS)

    Li, B.; Mathaudhu, S. N.

    Interactions between Mg17Al12 precipitates and { 10\\bar 12} < 10\\bar 1\\bar 1 > twin boundaries (TBs) in magnesium were studied by molecular dynamics simulations. The results obtained agree well with experimental observations in which precipitates can be entirely engulfed by { 10\\bar 12} < 10\\bar 1\\bar 1 > twins without being sheared. Structural analysis of the TBs in the atomic scale shows that the TBs are extremely incoherent during twin growth and highly deviate from the { 10\\bar 12} twinning plane as previously observed in a number of experiments. The simulation studies indicate that { 10\\bar 12} < 10\\bar 1\\bar 1 > twinning was accomplished solely by atomic shuffling that converts the parent lattice to the twin lattice without involving twinning dislocations, resulting in zero shear strain at the TBs.

  7. An Escherichia coli Nissle 1917 Missense Mutant Colonizes the Streptomycin-Treated Mouse Intestine Better than the Wild Type but Is Not a Better Probiotic

    PubMed Central

    Adediran, Jimmy; Leatham-Jensen, Mary P.; Mokszycki, Matthew E.; Frimodt-Møller, Jakob; Krogfelt, Karen A.; Kazmierczak, Krystyna; Kenney, Linda J.; Conway, Tyrrell

    2014-01-01

    Previously we reported that the streptomycin-treated mouse intestine selected for two different Escherichia coli MG1655 mutants with improved colonizing ability: nonmotile E. coli MG1655 flhDC deletion mutants that grew 15% faster in vitro in mouse cecal mucus and motile E. coli MG1655 envZ missense mutants that grew slower in vitro in mouse cecal mucus yet were able to cocolonize with the faster-growing flhDC mutants. The E. coli MG1655 envZ gene encodes a histidine kinase that is a member of the envZ-ompR two-component signal transduction system, which regulates outer membrane protein profiles. In the present investigation, the envZP41L gene was transferred from the intestinally selected E. coli MG1655 mutant to E. coli Nissle 1917, a human probiotic strain used to treat gastrointestinal infections. Both the E. coli MG1655 and E. coli Nissle 1917 strains containing envZP41L produced more phosphorylated OmpR than their parents. The E. coli Nissle 1917 strain containing envZP41L also became more resistant to bile salts and colicin V and grew 50% slower in vitro in mucus and 15% to 30% slower on several sugars present in mucus, yet it was a 10-fold better colonizer than E. coli Nissle 1917. However, E. coli Nissle 1917 envZP41L was not better at preventing colonization by enterohemorrhagic E. coli EDL933. The data can be explained according to our “restaurant” hypothesis for commensal E. coli strains, i.e., that they colonize the intestine as sessile members of mixed biofilms, obtaining the sugars they need for growth locally, but compete for sugars with invading E. coli pathogens planktonically. PMID:24478082

  8. Single crystal growth and physical properties of the new ternary compound Eu2Mg4Si3

    NASA Astrophysics Data System (ADS)

    Numakura, Ryosuke; Iizuka, Ryosuke; Michimura, Shinji; Katano, Susumu; Kosaka, Masashi

    2018-05-01

    We have studied the magnetic and electrical properties of new ternary europium magnesium silicide Eu2Mg4Si3. The single crystalline Eu2Mg4Si3 has been prepared by the Mg self-flux method. The compound crystalizes in the hexagonal Hf2Co4P3-type structure with space group P 6 bar 2 m with unit cell parameters a = 14.78 (3) Å and c = 4.434 (6) Å . Magnetic, electrical, and thermal properties indicate that the system undergoes two successive phase transitions, occurring at TN1 = 9.6 K and TN2 = 8.4 K . The estimated effective magnetic moment is close to the moment of free Eu2+ ion. The electrical resistivity data ρ (T) for Eu2Mg4Si3 show a metallic-like behavior from room temperature down to about 100 K. However, the ρ (T) data exhibit a notable upturn below 80 K and a maximum around TN1 and then suddenly decrease with decreasing temperature. These features are strongly suppressed by applying magnetic fields and a metallic temperature dependence eventually exhibits over the whole temperature range in a magnetic field of 30 kOe. Such behavior is observed in some magnetoresistive compounds.

  9. Complete matrix properties of [001](c) and [011](c) poled 0.33Pb(In(1/2)Nb(1/2))O(3)-0.38Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) single crystals.

    PubMed

    Sun, Enwei; Zhang, Rui; Wu, Fengmin; Cao, Wenwu

    2013-03-15

    The elastic, piezoelectric, and dielectric properties of [001](c) and [011](c) poled 0.33Pb(In(1/2)Nb(1/2))O(3)-0.38Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) single crystals have been fully characterized at room temperature, and the temperature and frequency dependence of the dielectric susceptibility ε(33) were also measured. The depoling temperature of this crystal is more than 20 °C higher than that of the corresponding binary 0.71Pb(Mg(1/3)Nb(2/3))O(3)-0.29PbTiO(3) system. From the measured P-E hysteresis loops, the coercive fields along [001](c) and [011](c) directions have been determined to be 6.0 kV/cm and 6.6 kV/cm, respectively, which indicate that these domain engineered ternary relaxor-based ferroelectric single crystals are excellent candidates for high-power applications.

  10. Mg- and K-bearing borates and associated evaporites at Eagle Borax spring, Death Valley, California: A spectroscopic exploration

    USGS Publications Warehouse

    Crowley, J.K.

    1996-01-01

    Efflorescent crusts at the Eagle Borax spring in Death Valley, California, contain an array of rare Mg and K borate minerals, several of which are only known from one or two other localities. The Mg- and/or K-bearing borates include aristarainite, hydroboracite, kaliborite, mcallisterite, pinnoite, rivadavite, and santite. Ulexite and probertite also occur in the area, although their distribution is different from that of the Mg and K borates. Other evaporite minerals in the spring vicinity include halite, thenardite, eugsterite, gypsum-anhydrite, hexahydrite, and bloedite. Whereas the first five of these minerals are found throughout Death Valley, the last two Mg sulfates are more restricted in occurrence and are indicative of Mg-enriched ground water. Mineral associations observed at the Eagle Borax spring, and at many other borate deposits worldwide, can be explained by the chemical fractionation of borate-precipitating waters during the course of evaporative concentration. The Mg sulfate and Mg borate minerals in the Eagle Borax efflorescent crusts point to the fractionation of Ca by the operation of a chemical divide involving Ca carbonate and Na-Ca borate precipitation in the subsurface sediments. At many other borate mining localities, the occurrence of ulexite in both Na borate (borax-kernite) and Ca borate (ulexite-colemanite) deposits similarly reflects ulexite's coprecipitation with Ca carbonate at an early concentration stage. Such ulexite may perhaps be converted to colemanite by later reaction with the coexisting Ca carbonate - the latter providing the additional Ca2+ ions needed for the conversion. Mg and Ca-Mg borates are the expected late-stage concentration products of waters forming ulexite-colemanite deposits and are therefore most likely to occur in the marginal zones or nearby mud facies of ulexite-colemanite orebodies. Under some circumstances, Mg and Ca-Mg borates might provide a useful prospecting guide for ulexite-colemanite deposits

  11. Language Arts Resource Guide K-12.

    ERIC Educational Resources Information Center

    Pitman, John C.

    One of a series designed to help districts refine and upgrade their current curricular offerings, this resource guide deals with the development of a unified K-12 language arts curriculum that combines the four major language arts components of listening, speaking, reading, and writing. Following a brief foreword and list of acknowledgments, the…

  12. Guidelines for Communication Arts: K-12.

    ERIC Educational Resources Information Center

    1971

    These guidelines are part of a total curricular program K-12 developed for use in the elementary and secondary schools of the Diocese of Cleveland. Objectives for the study of the communication arts in these grades are listed as follows: (1) Listening with attention, discrimination, and empathy, (2) Viewing with perception, discrimination, and…

  13. Digital Learning in California's K-12 Schools. Just the Facts

    ERIC Educational Resources Information Center

    Gao, Niu

    2015-01-01

    This fact page briefly discusses the following facts on digital learning in California's K-12: (1) As California implements new tests in its K-12 schools, technology infrastructure is a key concern; (2) Many districts are confident that they had enough bandwidth for online field tests; (3) Digital learning will require significantly greater…

  14. Formulating Independent School K-12 Quality Physical Education Program Guidelines

    ERIC Educational Resources Information Center

    Currie, Stuart M.; Phillips, Michael B.; Jubenville, Colby B.

    2012-01-01

    The purpose of this study was to formulate Tennessee independent school K-12 quality physical education program guidelines. A panel of 18 physical education representatives from Tennessee independent schools K-12 participated in a three-phase Delphi study and completed three opinionnaires via e-mail. In Phase One, Opinionnaire One solicited panel…

  15. Investing in K-12 Technology Equipment: Strategies for State Policymakers.

    ERIC Educational Resources Information Center

    Good, Dixie Griffin

    This report examines decisions regarding investments in K-12 technology. The first section presents an overview of technology in K-12 public schools, including a sampling of how technology is being used to further education goals for teachers, students, and administrators. The second section establishes a set of figures that indicate the current…

  16. Interstellar absorption in the Mg II resonance line k2 and h2 emissions

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.

    1981-01-01

    High-resolution (0.2 A) IUE spectra for the long wavelength range (1800-3000 A) have been studied. It is shown that narrow interstellar Mg II lines are seen in the center of the k2 and h2 emissions from nearby stars with large rotational velocities. For all observed stars, the radial velocity of the central k3 absorption component in the rest system of the star is strongly correlated with the mirror image of the radial velocity of the stars; this shows that a major fraction if not all of the k3 absorption is due to interstellar absorption in the solar neighborhood. The violet to red asymmetry of the k2 emission also correlates with the radial velocities of the star; this shows that the shift of k3 is due to the velocity shift of the local interstellar cloud with respect to the star.

  17. Copyright Updates for K-12 Librarians

    ERIC Educational Resources Information Center

    Johnson, Wendell G.

    2016-01-01

    Copyright concerns continue to bedevil K-12 librarians, who are often called upon to act as the copyright officers in public schools. This article describes recent copyright developments of concern to these librarians in three areas: a recent court case involving a university library, pending legislation supported by ALA, and a regulatory update.…

  18. K-12 Bolsters Ties to Engineering

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2013-01-01

    When science, technology, engineering and mathematics (STEM) education is discussed in the K-12 sphere, it often seems like shorthand for mathematics and science, with perhaps a nod to technology and even less, if any, real attention to engineering. But recent developments signal that the "e" in STEM may be gaining a firmer foothold at…

  19. State of the Nation: K-12 Online Learning in Canada

    ERIC Educational Resources Information Center

    Barbour, Michael K.

    2010-01-01

    Two years ago, the then North American Council for Online Learning released the initial "Snapshot State of the Nation: K-12 Online Learning in Canada" report. This study was the first systematic examination of K-12 distance education policies and activities in each of the thirteen Canadian provinces and territories. One year ago, the…

  20. Escherichia coli K-12: a cooperatively developed annotation snapshot—2005

    PubMed Central

    Riley, Monica; Abe, Takashi; Arnaud, Martha B.; Berlyn, Mary K.B.; Blattner, Frederick R.; Chaudhuri, Roy R.; Glasner, Jeremy D.; Horiuchi, Takashi; Keseler, Ingrid M.; Kosuge, Takehide; Mori, Hirotada; Perna, Nicole T.; Plunkett, Guy; Rudd, Kenneth E.; Serres, Margrethe H.; Thomas, Gavin H.; Thomson, Nicholas R.; Wishart, David; Wanner, Barry L.

    2006-01-01

    The goal of this group project has been to coordinate and bring up-to-date information on all genes of Escherichia coli K-12. Annotation of the genome of an organism entails identification of genes, the boundaries of genes in terms of precise start and end sites, and description of the gene products. Known and predicted functions were assigned to each gene product on the basis of experimental evidence or sequence analysis. Since both kinds of evidence are constantly expanding, no annotation is complete at any moment in time. This is a snapshot analysis based on the most recent genome sequences of two E.coli K-12 bacteria. An accurate and up-to-date description of E.coli K-12 genes is of particular importance to the scientific community because experimentally determined properties of its gene products provide fundamental information for annotation of innumerable genes of other organisms. Availability of the complete genome sequence of two K-12 strains allows comparison of their genotypes and mutant status of alleles. PMID:16397293

  1. ISOLEUCINE AND VALINE METABOLISM IN ESCHERICHIA COLI XI. K-12

    PubMed Central

    Leavitt, Richard I.; Umbarger, H. E.

    1962-01-01

    Leavitt, Richard I. (Harvard Medical School, Boston, Mass.) and H. E. Umbarger. Isoleucine and valine metabolism in Escherichia coli. XI. Valine inhibition of the growth of Escherichia coli strain K-12. J. Bacteriol. 83:624–630. 1962.—The inhibition of the growth of Escherichia coli strain K-12 by valine was shown to be due to the sensitivity of the acetohydroxybutyrate-forming system to valine. It was demonstrated that both E. coli strain W, a strain whose growth is unaffected by valine, and a valine-resistant mutant of strain K-12 have acetolactate- and acetohydroxybutyrate-forming systems which are less sensitive to valine than that of strain K-12. It was further shown that α-aminobutyrate accumulates in the culture fluid of the valine-sensitive strain when incubated in the presence of valine. The levels of valine in the “free amino acid pool” were examined and found to be related to the differences in valine sensitivity of the acetolactate-forming systems of the three strains. PMID:14463257

  2. Investigating the Potential of MOOCs in K-12 Teaching and Learning Environments

    ERIC Educational Resources Information Center

    Nigh, Jennifer; Pytash, Kristine E.; Ferdig, Richard E.; Merchant, William

    2015-01-01

    The massive open online course (MOOC) is a relatively new concept in K-12 teaching and learning environments. Although significant work has been done with MOOCs since 2008, it has only been recently that MOOCs have been studied with K-12 populations. The purpose of this study was to further examine the motivation of K-12 students enrolled in a…

  3. Problem-Based Learning in the Life Science Classroom, K-12

    ERIC Educational Resources Information Center

    McConnell, Tom; Parker, Joyce; Eberhardt, Janet

    2016-01-01

    "Problem-Based Learning in the Life Science Classroom, K-12" offers a great new way to ignite your creativity. Authors Tom McConnell, Joyce Parker, and Janet Eberhardt show you how to engage students with scenarios that represent real-world science in all its messy, thought-provoking glory. The scenarios prompt K-12 learners to immerse…

  4. K-12 Issues Will Await President

    ERIC Educational Resources Information Center

    Hoff, David J.; Klein, Alyson

    2008-01-01

    At the end of a presidential campaign in which education received some attention but never emerged as a top-tier issue, analysts were trying to look beyond the week's election to the K-12 issues awaiting the next president and gauge where they might fit as a new administration prepares to grapple with a global economic crisis. While education…

  5. [Pharmacokinetics of flomoxef in children undergoing chronic hemodialysis].

    PubMed

    Sasagawa, F; Nakano, T; Mito, Y; Sekine, O

    1993-07-01

    The pharmacokinetics of flomoxef (FMOX), an oxacephem antibiotic, were investigated in pediatric patients undergoing chronic hemodialysis. The results are summarized as follows. 1. FMOX was given intravenously in a single dose of 10 mg/kg to 5 pediatric patients (ranging from 7 to 15 years of age) undergoing chronic hemodialysis. It was also given in a dose of 5 mg/kg to 2 of these patients. Its concentrations in serum and urine were determined using bioassay. Pharmacokinetic analyses were performed using a two compartment open model. 2. The serum concentrations of FMOX, administered in doses of 10 mg/kg or 5 mg/kg on non-hemodialysis days, were 33.3 +/- 4.09 micrograms/ml (mean +/- standard deviation) and 17.6 micrograms/ml (mean) at 30 minutes after injection, 29.6 +/- 3.51 micrograms/ml and 15.9 micrograms/ml at 1 hour, 27.2 +/- 2.14 micrograms/ml and 15.1 micrograms/ml at 2 hours, 23.5 +/- 1.90 micrograms/ml and 13.0 micrograms/ml at 4 hours, 20.8 +/- 2.44 micrograms/ml and 12.2 micrograms/ml at 6 hours, 18.9 +/- 1.86 micrograms/ml and 11.0 micrograms/ml at 8 hours, and 9.64 +/- 1.43 micrograms/ml and 6.16 micrograms/ml at 24 hours, respectively. 3. The urinary concentrations of FMOX, administered in a dose of 10 mg/kg, were 42.4-123 micrograms/ml between 0-6 hours after injection, 14.1-52.5 micrograms/ml between 6-24 hours, and 2.86-23.7 micrograms/ml between 24-48 hours. The urinary excretion rate in the first 48 hours after injection ranged from 9.1 to 10.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Can oral vitamin K before elective surgery substitute for preoperative heparin bridging in patients on vitamin K antagonists?

    PubMed

    Steib, A; Barre, J; Mertes, M; Morel, M H; Nathan, N; Ozier, Y; Treger, M; Samama, C M

    2010-03-01

    After a vitamin K antagonist (VKA) overdose, 1-2 mg of oral vitamin K can lower the International Normalized Ratio (INR) to the therapeutic range. To establish whether oral vitamin K can substitute for heparin bridging and decrease the INR to < or = 1.5 before elective surgery. Patients on long-term VKAs were randomized either to heparin bridging after the last VKA dose on day -5 before surgery (group H) or to VKA treatment until day -2, followed by 1 mg of oral vitamin K on the day before surgery (group K). Blood clotting variables were assessed on days -5/-2, 1 and 0, and postoperatively. If the target INR was not achieved 2 h before incision, surgery was deferred or performed after injection of prothrombin complex concentrate (PCC). In 30 of 94 included patients, baseline INR was outside the chosen range (18, INR < 2; 12, INR > 3.5), leaving 34 eligible patients in group H and 30 in group K. The groups were balanced in terms of body mass index, VKA treatment duration and indication, scheduled surgery, preoperative and postoperative hemoglobin, and blood loss. The INR was significantly higher in group K on days -1 and 0 than in group H. An INR < or = 1.5 was not achieved in 20 group K patients (66%). Surgery was postponed or performed after PCC injection in 12 of these 20 patients. Oral vitamin K (1 mg) cannot substitute for heparin bridging before surgery. In addition, one-third of patients on VKAs were exposed to a risk of bleeding (overdose) or thrombosis (underdose), thus highlighting the need for new oral anticoagulants.

  7. Computational prediction of Mg-isotope fractionation between aqueous [Mg(OH2)6]2+ and brucite

    NASA Astrophysics Data System (ADS)

    Colla, Christopher A.; Casey, William H.; Ohlin, C. André

    2018-04-01

    The fractionation factor in the magnesium-isotope fractionation between aqueous solutions of magnesium and brucite changes sign with increasing temperature, as uncovered by recent experiments. To understand this behavior, the Reduced Partition Function Ratios and isotopic fractionation factors (Δ26/24Mgbrucite-Mg(aq)) are calculated using molecular models of aqueous [Mg(OH2)6]2+ and the mineral brucite at increasing levels of density functional theory. The calculations were carried out on the [Mg(OH2)6]2+·12H2O cluster, along with different Pauling-bond-strength-conserving models of the mineral lattice of brucite. Three conclusions were reached: (i) all levels of theory overestimate bond distances in the aqua ion complex relative to Tutton's salts; (ii) the calculations predict that brucite at 298.15 K is always enriched in the heavy isotope, in contrast with experimental observations; (iii) the temperature dependencies of Wimpenny et al. (2014) and Li et al. (2014) could only be achieved by fixing the bond distances in the [Mg(OH2)6]2+·12H2O cluster to values close to those observed in crystals that trap the hydrated ion.

  8. Population pharmacokinetics of ϵ-aminocaproic acid in adolescents undergoing posterior spinal fusion surgery

    PubMed Central

    Stricker, P. A.; Gastonguay, M. R.; Singh, D.; Fiadjoe, J. E.; Sussman, E. M.; Pruitt, E. Y.; Goebel, T. K.; Zuppa, A. F.

    2015-01-01

    Background Despite demonstrated efficacy of ϵ-aminocaproic acid (EACA) in reducing blood loss in adolescents undergoing spinal fusion, there are no population-specific pharmacokinetic data to guide dosing. The aim of this study was to determine the pharmacokinetics of EACA in adolescents undergoing spinal fusion surgery and make dosing recommendations. Methods Twenty children ages 12–17 years were enrolled, with 10 children in each of two groups based on diagnosis (idiopathic scoliosis or non-idiopathic scoliosis). Previously reported data from infants undergoing craniofacial surgery were included in the model to enable dosing recommendations over a wide range of weights, ages, and diagnoses. A population non-linear mixed effects modelling approach was used to characterize EACA pharmacokinetics. Results Population pharmacokinetic parameters were estimated using a two-compartment disposition model with allometrically scaled weight and an age effect on clearance. Pharmacokinetic parameters for the typical patient were a plasma clearance of 153 ml min−1 70 kg−1 (6.32 ml min−1 kg−0.75), intercompartmental clearance of 200 ml min−1 70 kg−1 (8.26 ml min−1 kg−0.75), central volume of distribution of 8.78 litre 70 kg−1 (0.13 litre kg−1), and peripheral volume of distribution of 15.8 litre 70 kg−1 (0.23 litre kg−1). Scoliosis aetiology did not have a clinically significant effect on drug pharmacokinetics. Conclusions The following dosing schemes are recommended according to patient weight: weight <25 kg, 100 mg kg−1 loading dose and 40 mg kg−1 h−1 infusion; weight ≤25 kg–<50 kg, 100 mg kg−1 loading dose and 35 mg kg−1 h−1 infusion; and weight ≥50 kg, 100 mg kg−1 loading dose and 30 mg kg−1 h−1 infusion. An efficacy trial employing this dosing strategy is warranted. Clinical trial registration NCT01408823. PMID:25586726

  9. Phase dissolution of γ-Mg17Al12 during homogenization of as-cast AZ80 Magnesium alloy and its effect on room temperature mechanical properties

    NASA Astrophysics Data System (ADS)

    Kulkarni, Rahul R.; Prabhu, Nityanand; Hodgson, Peter D.; Kashyap, Bhagwati P.

    As-cast AZ80 Mg alloy contains α-Mg, partially divorce eutectic of α and γ (Mg17Al12), fully divorce eutectic of α and γ, and lamellar eutectic of α and γ phases. During homogenization, second phase (γ-Mg17Al12) gets dissolved can change the mechanical properties. Therefore, the aim of the present work is to bring out the kinetics of dissolution of γ phase and evaluate its effect on mechanical properties. Microstructure evolution during homogenization was investigated as a function of time for 0.5 to 100 h and at the temperatures of 400° and 439°C. In as-cast state, this material was found to contain 70% α-Mg and 30% eutectic phase. With increasing homogenization time, dissolution of lamellar eutectic occurs first which is followed by dissolution of fully divorce eutectic and partially divorce eutectic. The dissolution kinetics of γ phase was analyzed based on the decrease in its volume fraction as a function of time. The time exponent for dissolution was found to be 0.38 and the activation energy for the dissolution of γ phase was found to be 84.1 kJ/mol. This dissolution of γ phase leads to decrease in hardness and tensile strength with increase in homogenization time.

  10. A possible width-luminosity correlation of the Ca II K1 and Mg II k1 features. [of stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.; Shine, R. A.; Linsky, J. L.

    1975-01-01

    Existing high resolution stellar profiles of the Ca II and Mg II resonance lines suggest a possible width-luminosity correlation of the K1 minimum features. It is shown that such a correlation can be simply understood if the continuum optical depth of the stellar temperature minimum is relatively independent of surface gravity as suggested by three stars studied in detail.

  11. A Vision in Aeronautics: The K-12 Wind Tunnel Project

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A Vision in Aeronautics, a project within the NASA Lewis Research Center's Information Infrastructure Technologies and Applications (IITA) K-12 Program, employs small-scale, subsonic wind tunnels to inspire students to explore the world of aeronautics and computers. Recently, two educational K-12 wind tunnels were built in the Cleveland area. During the 1995-1996 school year, preliminary testing occurred in both tunnels.

  12. A Critique of the Brave New World of K-12

    ERIC Educational Resources Information Center

    Salmani-Nodoushan, Mohammad Ali

    2008-01-01

    Over the past few decades has changed so rapidly that remote areas of the Earth are now inhabited by human beings. Technology has also developed and people can stay at home and have access to virtual schools. This has stimulated the need for K-12 education. K-12 education has emerged from the no-child-left-behind concerns of governments for…

  13. Structure and temperature-dependent phase transitions of lead-free Bi 1/2Na 1/2TiO 3-Bi 1/2K 1/2TiO 3-K 0.5Na 0.5NbO 3 piezoceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anton, Eva-Maria; Schmitt, Ljubomira Ana; Hinterstein, Manuel

    2014-05-28

    Structure and phase transitions of (1-y)((1-x)Bi 1/2Na 1/2TiO 3-xBi 1/2K 1/2TiO 3)-yK 0.5Na 0.5NbO 3 (x; y) piezoceramics (0.1 ≤ x ≤ 0.4; 0 ≤ y ≤ 0.05) were investigated by transmission electron microscopy, neutron diffraction, temperature-dependent x-ray diffraction, and Raman spectroscopy. The local crystallographic structure at room temperature (RT) does not change by adding K 0.5Na 0.5NbO 3 to Bi 1/2Na 1/2TiO 3-xBi 1/2K 1/2TiO 3 for x = 0.2 and 0.4. The average crystal structure and microstructure on the other hand develop from mainly long-range polar order with ferroelectric domains to short-range order with polar nanoregions displaying amore » more pronounced relaxor character. The (0.1; 0) and (0.1; 0.02) compositions exhibit monoclinic Cc space group symmetry, which transform into Cc + P4bm at 185 and 130 °C, respectively. This high temperature phase is stable at RT for the morphotropic phase boundary compositions of (0.1; 0.05) and all compositions with x = 0.2. For the compositions of (0.1; 0) and (0.1; 0.02), local structural changes on heating are evidenced by Raman; for all other compositions, changes in the long-range average crystal structure were observed.« less

  14. Application of a relativistic accretion disc model to X-ray spectra of LMC X-1 and GRO J1655-40

    NASA Astrophysics Data System (ADS)

    Gierliński, Marek; Maciołek-Niedźwiecki, Andrzej; Ebisawa, Ken

    2001-08-01

    We present a general relativistic accretion disc model and its application to the soft-state X-ray spectra of black hole binaries. The model assumes a flat, optically thick disc around a rotating Kerr black hole. The disc locally radiates away the dissipated energy as a blackbody. Special and general relativistic effects influencing photons emitted by the disc are taken into account. The emerging spectrum, as seen by a distant observer, is parametrized by the black hole mass and spin, the accretion rate, the disc inclination angle and the inner disc radius. We fit the ASCA soft-state X-ray spectra of LMC X-1 and GRO J1655-40 by this model. We find that, having additional limits on the black hole mass and inclination angle from optical/UV observations, we can constrain the black hole spin from X-ray data. In LMC X-1 the constraint is weak, and we can only rule out the maximally rotating black hole. In GRO J1655-40 we can limit the spin much better, and we find 0.68<=a<=0.88. Accretion discs in both sources are radiation-pressure dominated. We do not find Compton reflection features in the spectra of any of these objects.

  15. Photoluminescence and thermoluminescence of K2 Mg(SO4 )2 :Eu and evaluation of its kinetic parameters.

    PubMed

    Deshpande, Archana; Dhoble, N S; Gedam, S C; Dhoble, S J

    2017-08-01

    The K 2 Mg(SO 4 ) 2 :Eu phosphor, synthesized by a solid-state diffusion method, was studied for its photoluminescence (PL) and thermoluminescence (TL) characteristics. The X-ray diffraction (XRD) pattern of the material was matched with the standard JCPDF No. 36-1499. For PL characteristics, K 2 Mg(SO 4 ) 2 :Eu 2 + showed an emission peak at 474 nm when excited at 340 nm, while it showed Eu 3 + emission at 580 nm, and 594 nm splitting at 613 nm and 618 nm for an excitation of 396 nm wavelength due to radiative transitions from 5 D 0 to 7 F j (j = 0, 1, 2, 3). The Commission International de I' Eclairage (CIE) chromaticity coordinates were also calculated for the K 2 Mg(SO 4 ) 2 :Eu phosphor, and were close to the NTSC standard values. For the TL study, the prepared sample was irradiated using a 60 Co source of γ-irradiation at the dose rate of 0.322 kGy/h for 2 min. The formation of traps in K 2 Mg (SO 4 ) 2 :Eu and the effects of γ-radiation dose on the glow curve are discussed. Well defined broad glow peaks were obtained at 186°C. With increasing γ-ray dose, the sample showed linearity in intensity. The presence of a single glow peak indicated that there was only one set of traps being activated within the particular temperature range. The presented phosphors were also studied for their fading, reusability and trapping parameters. There was just 2% fading during a period of 30 days, indicating no serious fading problem. Kinetic parameters were calculated using the initial rise method and Chen's half-width method. Activation energy and frequency factor were found to be 0.77 eV and 1.41 × 10 6  sec -1 . Copyright © 2016 John Wiley & Sons, Ltd.

  16. First-order ferromagnetic to helimagnetic transition in MgMn6Ge6

    NASA Astrophysics Data System (ADS)

    Mazet, T.; Ihou-Mouko, H.; Malaman, B.

    2008-02-01

    The magnetic and magnetocaloric properties of the new HfFe6Ge6-type (P6/mmm) MgMn6Ge6 compound have been studied by magnetic measurements and powder neutron diffraction experiments. MgMn6Ge6 magnetically orders at TC˜345 K in a ferromagnetic easy-plane arrangement. At TAF˜235 K, it undergoes a first-order transition to a helical structure, characterized by a temperature dependent propagation vector k =⟨0,0,qz⟩ (qz˜0.116 reciprocal lattice units at 1.4 K), without structural modification. The Mn atoms carry a magnetic moment of about 2 μB. A metamagnetic transition with a low critical field (Hcr<1 T) is observed below TAF. At low temperature, both magnetic and magnetocaloric data strongly suggest that some kinds of intermediate noncollinear ferromagnetic arrangements are stabilized above the critical field while the pure ferromagnetic state is obtained for significantly higher magnetic fields (H >5 T). The magnitude of the magnetic entropy change at TC (-ΔSM˜20.5 mJ cm-3 K-1 for ΔH =5 T) is about 25% that of Gd metal. The magnetocaloric effect at the order-order transition is of opposite sign and of lower magnitude.

  17. Hysteretic photochromic switching of Eu-Mg defects in GaN links the shallow transient and deep ground states of the Mg acceptor.

    PubMed

    Singh, A K; O'Donnell, K P; Edwards, P R; Lorenz, K; Kappers, M J; Boćkowski, M

    2017-02-03

    Although p-type activation of GaN by Mg underpins a mature commercial technology, the nature of the Mg acceptor in GaN is still controversial. Here, we use implanted Eu as a 'spectator ion' to probe the lattice location of Mg in doubly doped GaN(Mg):Eu. Photoluminescence spectroscopy of this material exemplifies hysteretic photochromic switching (HPS) between two configurations, Eu0 and Eu1(Mg), of the same Eu-Mg defect, with a hyperbolic time dependence on 'switchdown' from Eu0 to Eu1(Mg). The sample temperature and the incident light intensity at 355 nm tune the characteristic switching time over several orders of magnitude, from less than a second at 12.5 K, ~100 mW/cm 2 to (an estimated) several hours at 50 K, 1 mW/cm 2 . Linking the distinct Eu-Mg defect configurations with the shallow transient and deep ground states of the Mg acceptor in the Lany-Zunger model, we determine the energy barrier between the states to be 27.7(4) meV, in good agreement with the predictions of theory. The experimental results further suggest that at low temperatures holes in deep ground states are localized on N atoms axially bonded to Mg acceptors.

  18. Phase transition, crystal water and low thermal expansion behavior of Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Fang; Liu, Xiansheng; Song, Wenbo

    2014-10-15

    Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} for 0≤x≤1.0 are synthesized to reduce the phase transition temperature of Al{sub 2}W{sub 3}O{sub 12}. It is found that the incorporation of (ZrMg){sup 6+} into the lattice of Al{sub 2}W{sub 3}O{sub 12} not only reduces its orthorhombic-to-monoclinic phase transition temperature but also elevates its softening temperature, broadening its applicable temperature range considerably. Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} with x<0.5 exhibit low coefficients of thermal expansion (CTEs) and non-hygroscopicity, while those for x≥0.7 are obviously hygroscopic and the CETs decrease with increasing the content of (ZrMg){sup 6+} so that Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12} and ZrMgW{submore » 3}O{sub 12} exhibit negative thermal expansion. Temperature-dependent Raman spectroscopic study shows the hardening of W–O bonds above 373 K which is attributed to the release of crystal water. The effect of crystal water on the thermal expansion property is discussed based on the hydrogen bond between H in crystal water and electronegative O in Al(ZrMg)–O–W linkages. - Graphical abstract: (a and b) Temperature dependent Raman spectra of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12} (x=0.1, 0.2), (c and d) Building block of a unit cell of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O) and schematic showing the effect of crystal water on Al(Zr, Mg)–O–W linkages. - Highlights: • (ZrMg){sup 6+} reduces orthorhombic-to-monoclinic phase transition of Al{sub 2}W{sub 3}O{sub 12}. • The incorporation of (ZrMg){sup 6+} elevates the softening temperature of Al{sub 2}W{sub 3}O{sub 12}. • Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} (x<0.5) exhibit low CTEs and non-hygroscopicity. • Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12}·0.8H{sub 2}O and ZrMgW{sub 3}O{sub 12}·2H{sub 2}O present NTE. • Hydrogen bond between H in H{sub 2}O and O in Al(ZrMg)–O–W affects thermal expansion.« less

  19. Tetragonal Almandine, (Fe,Mg,Ca,Na)3(Al,Si,Mg)2Si3O12, a New High-Pressure Mineral from the Shergotty Impact on Mars: an Integrated FESEM-EPMA-Synchrotron Diffraction Investigation

    NASA Astrophysics Data System (ADS)

    Ma, C.; Tschauner, O. D.

    2016-12-01

    The combination of FESEM-EDS-EBSD, EPMA, and synchrotron microdiffraction is developing into a powerful tool for identification of micron-scale minerals in rocks such as high-pressure phases in shocked meteorites. During a nanomineralogy investigation of the Shergotty meteorite using this approach, we have identified a new shock-induced high-pressure silicate, majoritic almandine with a tetragonal I41/a structure, in an impact melt pocket. The Shergotty meteorite, which fell in the Gaya district, Bihar, India in 1865, is a Martian basaltic shergottite with shock features. Tetragonal almandine in Shergotty occurs as aggregates of subhedral crystals, 0.8 - 2.5 µm in diameter, along with stishovite in the central region of a shock melt pocket, showing an empirical formula of (Fe1.16Ca0.75Mg0.61Na0.42Mn0.03K0.01)(Al1.16Si0.63Mg0.19Ti0.02)Si3O12. Its general formula is (Fe,Mg,Ca,Na)3(Al,Si,Mg)2Si3O12. EBSD indicated this phase has a garnet-related structure. Synchrotron X-ray diffraction revealed that this garnet has actually a tetragonal structure (I41/a) with unit cell dimensions: a = 11.585(9) Å, c = 11.63(4) Å, V = 1561(7) Å3, and Z = 8. Tetragonal almandine is the polymorph of cubic almandine, a new high-pressure garnet mineral, formed by shock metamorphism via the Shergotty impact event on Mars. It apparently crystallized from Fe-rich shock-induced melt under high-pressure and high-temperature conditions.

  20. An Examination of Ideology among Selected K12 Christian School Superintendents

    ERIC Educational Resources Information Center

    Dolson, Jimmy L.

    2013-01-01

    This research project focused on explaining the decision making process of K12 Christian school superintendents whose schools belong to the Association of Christian Schools International (ACSI) organization. In spite of their similar religious and philosophical beliefs, ACSI K12 Christian school superintendents differed significantly in…

  1. Mathematics. Exceptional Child Education Curriculum K-12.

    ERIC Educational Resources Information Center

    Jordon, Thelma; And Others

    The mathematics curriculum provides a framework of instruction for exceptional child education in grades K-12. Content areas include: numeration, whole numbers, rational numbers, real/complex numbers, calculator literacy, measurement, geometry, statistics, functions/relations, computer literacy, and pre-algebra. The guide is organized by content…

  2. Structural, dielectric and magnetic studies of Mn doped Y-type barium hexaferrite (Ba2Mg2Fe12O22)

    NASA Astrophysics Data System (ADS)

    Abdullah, Md. F.; Pal, P.; Mohapatra, S. R.; Yadav, C. S.; Kaushik, S. D.; Singh, A. K.

    2018-04-01

    The polycrystalline single phase Ba2Mg2Fe12O22 (BMF) and Ba2Mg2Fe11.52Mn0.48O22 (BMFM) were prepared using conventional solid state reaction route. We report the modification in structural, dielectric and magnetic properties of BMF due to 4% Mn doping at Fe site. Phase purity of both sample are confirmed by the Reitveld refinement of XRD data. Temperature dependent dielectric study shows decrease in dielectric constant (ɛ') and dielectric loss (tan δ) due to 4% Mn doping in parent sample. The ferrimagnetic to paramagnetic transition temperature (Tc) in doped sample decreases from 277°C to 150°C. Room temperature magnetization measurement shows ferrimagnetic behavior for both the samples. We have fitted the saturation magnetization data at 300 K by using least square method which confirms the enhancement of saturation magnetization and magnetic anisotropy constant in doped sample.

  3. Social Networking for the K-12 Set

    ERIC Educational Resources Information Center

    Klein, Jim

    2008-01-01

    Education technology leaders are ever seeking new ways to eliminate the traditional social and geographic boundaries that hinder communication and collaboration for both K-12 students and educators. Larger districts with geographically dispersed schools often find that innovative ideas for technology use and integration are balkanized into…

  4. Effects of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in Wistar rats.

    PubMed

    Olatunji, Lawrence A; Usman, Taofeek O; Adebayo, Joseph O; Olatunji, Victoria A

    2012-09-01

    To investigate the effects of oral administration of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in rats. The 25 and 50 mg/(kg·d) of aqueous extracts of H. sabdariffa were respectively given to rats in the experimental groups for 28 d, and rats in the control group received an appropriate volume of distilled water as vehicle. Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in the kidney were assayed by spectrophotometric method. Administrations of 25 and 50 mg/(kg·d) of aqueous extract of H. sabdariffa significantly decreased the Ca(2+)-Mg(2+)-ATPase activity in the kidney of rats (P<0.05). However, the renal Na(+)-K(+)-ATPase activity of the experimental rats was not affected by either dose of the extract. And the plasma Na(+), K(+) and Ca(2+) levels of the experimental rats had no significant changes. Administration of either dose of the extract did not result in any significant changes in body and kidney weights, the concentrations of plasma albumin and total protein, and alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. However, concentrations of creatinine and urea were significantly reduced by 50 mg/kg of the extract (P<0.05). The present study indicates that oral administration of aqueous extract of H. sabdariffa may preserve the renal function despite a decreased renal Ca(2+)-Mg(2+)-ATPase activity.

  5. Analgesic effects of tramadol, carprofen or multimodal analgesia in rats undergoing ventral laparotomy.

    PubMed

    Zegre Cannon, Coralie; Kissling, Grace E; Goulding, David R; King-Herbert, Angela P; Blankenship-Paris, Terry

    2011-03-01

    In this study, the authors evaluated the analgesic efficacy of tramadol (an opioid-like analgesic), carprofen (a nonsteroidal anti-inflammatory drug) and a combination of both drugs (multimodal therapy) in a rat laparotomy model. The authors randomly assigned rats to undergo either surgery (abdominal laparotomy with visceral manipulation and anesthesia) or anesthesia only. Rats in each group were treated with tramadol (12.5 mg per kg body weight), carprofen (5 mg per kg body weight), a combination of tramadol and carprofen (12.5 mg per kg body weight and 5 mg per kg body weight, respectively) or saline (anesthesia control group only; 5 mg per kg body weight). The authors administered analgesia 10 min before anesthesia, 4 h after surgery or (for the rats that received anesthesia only) anesthesia and 24 h after surgery or anesthesia. They measured locomotor activity, running wheel activity, feed and water consumption, body weight and fecal corticosterone concentration of each animal before and after surgery. Clinical observations were made after surgery or anesthesia to evaluate signs of pain and distress. The authors found that carprofen, tramadol and a combination of carprofen and tramadol were all acceptable analgesia regimens for a rat laparotomy model.

  6. Magnesium and cadmium containing Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd

    NASA Astrophysics Data System (ADS)

    Johnscher, Michael; Stein, Sebastian; Niehaus, Oliver; Benndorf, Christopher; Heletta, Lukas; Kersting, Marcel; Höting, Christoph; Eckert, Hellmut; Pöttgen, Rainer

    2016-02-01

    Twenty-eight new Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd with different rare earth elements were synthesized from the elements in sealed niobium ampoules in a water-cooled sample chamber of an induction furnace. The samples were characterized by powder X-ray diffraction. The cell volumes show the expected lanthanide contraction. The structures of YPd2Cd, GdPd2Cd, GdAu2Cd, Y1.12Ag2Mg0.88 and GdAg2Mg were refined based on single crystal diffractometer data. The magnetic properties were determined for fifteen phase pure samples. LuAu2Mg is a weak Pauli paramagnet with a susceptibility of 1.0(2) × 10-5 emu mol-1 at room temperature. The remaining samples show stable trivalent rare earth ions and most of them order magnetically at low temperatures. The ferromagnet GdAg2Mg shows the highest ordering temperature of TC = 98.3 K. 113Cd and 89Y MAS NMR spectra of YAu2Cd and YPd2Cd confirm the presence of unique crystallographic sites. The resonances are characterized by large Knight shifts, whose magnitude can be correlated with electronegativity trends.

  7. Students with Special Health Care Needs in K-12 Virtual Schools

    ERIC Educational Resources Information Center

    Fernandez, Heidi; Ferdig, Richard E.; Thompson, Lindsay A.; Schottke, Katherine; Black, Erik W.

    2016-01-01

    This study sought to establish a baseline for understanding the epidemiology of online K-12 students with special health care needs, determine the prevalence in K-12 online schooling of students from certain racial/ethnic backgrounds, those with socioeconomic disadvantages, and determine how these students perform in online classes compared to…

  8. Framing K-12 partnerships in order to make a difference.

    PubMed

    Hamos, James E

    2006-06-01

    The Health Professions Partnership Initiative (HPPI) furthered the establishment of partnerships between academic health centers and K-12 school systems. The present article contends that partnerships in efforts such as the HPPI exist in varying degrees of depth with deeper partnerships being those based in a concept of mutuality even as partners continue to maintain institutional identity. In the context of K-12 schools, the article reinforces the view that K-12 students, teachers, and administrators can benefit through partnership contexts, but also suggests that institutions of higher education-including academic health centers-should enter into partnerships because they benefit when they commit as stakeholders in the outcomes, not principally as altruistic good neighbors to the schools. Partnerships can continue to grow when multiple stakeholders accept mutual dependence as a norm, with goals, processes, and outcomes impacting each partner.

  9. Neutron study of B 12 coenzyme at 15 K

    NASA Astrophysics Data System (ADS)

    Bouquiere, J. P.

    1992-06-01

    This high resolution and low temperature study, at 15 K, of the vitamin B 12 coenzyme ( C72H100N18O17PCo) was undertaken to confirm and clarify the water networks identified at 279 K by Savage [1]. Details of the data collection and refinement of the low temperature structure are described, a comparison of the coenzyme molecule structures at 15 and 279 K is made, and that of solvent structures outlined.

  10. Legitimizing Community Engagement with K-12 Schools

    ERIC Educational Resources Information Center

    Furco, Andrew

    2013-01-01

    This article examines the issue of internal legitimization and its importance in securing high-quality community engagement in K-12 schools. Drawing on the literature from the fields of community engagement, school reform, school-university partnerships, and school-community partnerships, this article describes some of the prevailing challenges…

  11. Developing an Environmental Education Program, K-12.

    ERIC Educational Resources Information Center

    Stapp, William B.; Visse, Ellen Vande

    Strategy for developing and implementing an environmental education program in grades K-12 is proposed in this booklet. Its goal is to help students become environmentally educated decision-makers; to understand the importance of relating ecological, economic, social, technological, and political information when working toward the solution of…

  12. Interview with Joe Freidhoff: A Bird's-Eye View of K-12 Online Learning

    ERIC Educational Resources Information Center

    Pourreau, Leslie

    2015-01-01

    The intent of this article is to introduce long-time "Online Learning" readership to the field of K-12 online learning while also providing direction for the K-12 online learning scholars about where the field is going or should be going in terms of meeting the needs of K-12 stakeholders. Recently an interview was conducted with Dr. Joe…

  13. Outstanding Science Trade Books for Students K-12.

    ERIC Educational Resources Information Center

    Science Teacher, 2003

    2003-01-01

    Presents outstanding science trade books published in 2002 for students in grades K-12. Sections include Archaeology, Anthropology, and Paleontology; Biography; Environment and Ecology; Life Science; Physical Science; and Science-Related Careers. (KHR)

  14. Teacher Perception of Barriers and Benefits in K-12 Technology Usage

    ERIC Educational Resources Information Center

    Carver, Lin B.

    2016-01-01

    This study explores K-12 teachers' perceptions of the benefits and barriers to technology integration by either teachers or students in K-12 instruction. The sample was composed of 68 students enrolled in online classes in the graduate studies in education department of a small private liberal arts institution in the southeast. Data was collected…

  15. Integrating Data Mining in Program Evaluation of K-12 Online Education

    ERIC Educational Resources Information Center

    Hung, Jui-Long; Hsu, Yu-Chang; Rice, Kerry

    2012-01-01

    This study investigated an innovative approach of program evaluation through analyses of student learning logs, demographic data, and end-of-course evaluation surveys in an online K-12 supplemental program. The results support the development of a program evaluation model for decision making on teaching and learning at the K-12 level. A case study…

  16. Predicting Maintenance Doses of Vancomycin for Hospitalized Patients Undergoing Hemodialysis.

    PubMed

    El Nekidy, Wasim S; El-Masri, Maher M; Umstead, Greg S; Dehoorne-Smith, Michelle

    2016-01-01

    Methicillin-resistant Staphylococcus aureus is a leading cause of death in patients undergoing hemodialysis. However, controversy exists about the optimal dose of vancomycin that will yield the recommended pre-hemodialysis serum concentration of 15-20 mg/L. To develop a data-driven model to optimize the accuracy of maintenance dosing of vancomycin for patients undergoing hemodialysis. A prospective observational cohort study was performed with 164 observations obtained from a convenience sample of 63 patients undergoing hemodialysis. All vancomycin doses were given on the floor after completion of a hemodialysis session. Multivariate linear generalized estimating equation analysis was used to examine independent predictors of pre-hemodialysis serum vancomycin concentration. Pre-hemodialysis serum vancomycin concentration was independently associated with maintenance dose ( B = 0.658, p < 0.001), baseline pre-hemodialysis serum concentration of the drug ( B = 0.492, p < 0.001), and interdialytic interval ( B = -2.133, p < 0.001). According to the best of 4 models that were developed, the maintenance dose of vancomycin required to achieve a pre-hemodialysis serum concentration of 15-20 mg/L, if the baseline serum concentration of the drug was also 15-20 mg/L, was 5.9 mg/kg with interdialytic interval of 48 h and 7.1 mg/kg with interdialytic interval of 72 h. However, if the baseline pre-hemodialysis serum concentration was 10-14.99 mg/L, the required dose increased to 9.2 mg/kg with an interdialytic interval of 48 h and 10.0 mg/kg with an interdialytic interval of 72 h. The maintenance dose of vancomycin varied according to baseline pre-hemodialysis serum concentration of the drug and interdialytic interval. The current practice of targeting a pre-hemodialysis concentration of 15-20 mg/L may be difficult to achieve for the majority of patients undergoing hemodialysis.

  17. Energy Retrofit for Aging K-12 Schools.

    ERIC Educational Resources Information Center

    3D/International, Houston, TX.

    Successfully retrofitting aging K-12 schools using energy conservation measures (ECM) that can improve the physical plant and reduce energy consumption are explored. Topics explore how certain ECM measures can benefit educational facilities, why retrofitting begun sooner rather than later is important, how to finance the retrofit program, and the…

  18. Student Success in Online K-12 Education

    ERIC Educational Resources Information Center

    Ronsisvalle, Tammy; Watkins, Ryan

    2005-01-01

    While online education has made great strides in recent years to become an accepted component of higher education, with many colleges now offering accredited online degree programs, the current opportunities and challenges of online K-12 education are still awash in the turbulent waters of regional politics, temperamental technologies, changing…

  19. Development of an Attitude Scale to Assess K-12 Teachers' Attitudes toward Nanotechnology

    NASA Astrophysics Data System (ADS)

    Lan, Yu-Ling

    2012-05-01

    To maximize the contributions of nanotechnology to this society, at least 60 countries have put efforts into this field. In Taiwan, a government-funded K-12 Nanotechnology Programme was established to train K-12 teachers with adequate nanotechnology literacy to foster the next generation of Taiwanese people with sufficient knowledge in nanotechnology. In the present study, the Nanotechnology Attitude Scale for K-12 teachers (NAS-T) was developed to assess K-12 teachers' attitudes toward nanotechnology. The NAS-T included 23 Likert-scale items that can be grouped into three components: importance of nanotechnology, affective tendencies in science teaching, and behavioural tendencies to teach nanotechnology. A sample of 233 K-12 teachers who have participated in the K-12 Nanotechnology Programme was included in the present study to investigate the psychometric properties of the NAS-T. The exploratory factor analysis of this teacher sample suggested that the NAS-T was a three-factor model that explained 64.11% of the total variances. This model was also confirmed by the confirmatory factor analysis to validate the factor structure of the NAS-T. The Cronbach's alpha values of three NAS-T subscales ranged from 0.89 to 0.95. Moderate to strong correlations among teachers' NAS-T domain scores, self-perception of own nanoscience knowledge, and their science-teaching efficacy demonstrated good convergent validity of the NAS-T. As a whole, psychometric properties of the NAS-T indicated that this instrument is an effective instrument for assessing K-12 teachers' attitudes toward nanotechnology. The NAS-T will serve as a valuable tool to evaluate teachers' attitude changes after participating in the K-12 Nanotechnology Programme.

  20. K-12 Students Flock To ToxTown In San Diego: Results of an SOT K-12 Education Outreach Workshop

    EPA Science Inventory

    Just prior to the start of the 2015 Annual Meeting in San Diego, hundreds of K-12 students, teachers, and science enthusiasts visited the ToxTown booth at the annual San Diego Festival of Science and Engineering grand finale event, EXPO Day. Over 20,000 attendees participated in ...

  1. Review of "Overcoming the Governance Challenge in K-12 Online Learning"

    ERIC Educational Resources Information Center

    Barbour, Michael

    2012-01-01

    This fifth and final paper in the Fordham Institute's series examining digital learning policy is "Overcoming the Governance Challenge in K-12 Online Learning". The purpose of this report is to outline the steps required to move the governance of K-12 online learning from the local district level to the less restrictive state level and to create a…

  2. A Framework for Quality K-12 Engineering Education: Research and Development

    ERIC Educational Resources Information Center

    Moore, Tamara J.; Glancy, Aran W.; Tank, Kristina M.; Kersten, Jennifer A.; Smith, Karl A.; Stohlmann, Micah S.

    2014-01-01

    Recent U.S. national documents have laid the foundation for highlighting the connection between science, technology, engineering and mathematics at the K-12 level. However, there is not a clear definition or a well-established tradition of what constitutes a quality engineering education at the K-12 level. The purpose of the current work has been…

  3. Policy Shop Casts Long K-12 Shadow

    ERIC Educational Resources Information Center

    Ujifusa, Andrew

    2012-01-01

    In nearly 40 years of legislative advocacy, the American Legislative Exchange Council (ALEC)--a free-market, limited-government group now drawing intense scrutiny for its support of a controversial self-defense law--has had a significant influence on K-12 education through its model legislation and work with state lawmakers to promote such…

  4. What Matters to Career K-12 Educators

    ERIC Educational Resources Information Center

    Harris, Mary M.

    2014-01-01

    Case studies about issues arising from education policy were written between 2003 and 2011 by doctoral candidates in Curriculum and Instruction who were career K-12 educators. Literary analysis was employed in grouping 57 case studies, which described primarily situations that occurred in school districts in one large metropolitan area, by topic…

  5. Inspiring the Next Generation: Astronomy Catalyzes K12 STEM Education

    NASA Astrophysics Data System (ADS)

    Borders, Kareen; Thaller, Michelle; Winglee, Robert; Borders, Kyla

    2017-06-01

    K-12 educators need effective and relevant astronomy professional development. NASA's Mission Science provides innovative and accessible opportunities for K-12 teachers. Science questions involve scale and distance, including Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers can gain an understanding of basic telescopes, the history of telescopes, ground and satellite based telescopes, and models of JWST Telescope. An in-depth explanation of JWST and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. During teacher training, we taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of lenticulars and diagramming of infrared data, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars.We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development.Funding was provided by Washington STEM, NASA, and the Washington Space Grant Consortium.

  6. Impact of a long-term fire retardant (Fire Trol 931) on the leaching of Ca, Mg, and K from a Mediterranean forest loamy soil.

    PubMed

    Michalopoulos, Charalampos; Koufopoulou, Sofia; Tzamtzis, Nikolaos; Pappa, Athina

    2016-03-01

    The present laboratory study was conducted in pot soil taken from forest. The leaching of calcium (Ca), magnesium (Mg), and potassium (K) (plant macronutrients) due to the application of a nitrogen phosphate-based long-term fire retardant (LTFR) (Fire Trol 931) was investigated. The concentrations of Ca(2+), Mg(2+), and K(+) were measured in the resulting leachates from pots with forest soil and pine tree alone and in combination with fire. Magnesium is a minor component of Fire Trol 931. The leaching of Ca(2+), Mg(2+), and K(+) from treated soils with the retardant pots was significantly greater than that from control pots. The leaching of Mg(2+) was found to be of small percentage of the initially applied Mg quantities. Fire Trol 931 application resulted in the leaching of Ca(2+), Mg(2+), and K(+) from a typical Mediterranean forest soil in pots, following the application of simulated annual precipitation probably due to ammonium (one of the major retardant components) soil deposition that mobilizes base cations from the soil. It seems that LTFR application may result in chemical leaching from the soil to the drainage water.

  7. The SERC K12 Educators Portal to Teaching Activities and Pedagogic Approaches

    NASA Astrophysics Data System (ADS)

    Larsen, K.; Kirk, K. B.; Manduca, C. A.; Ledley, T. S.; Schmitt, L.

    2013-12-01

    The Science Education Resource Center (SERC) has created a portal to information for K12 educators to provide high-quality grade level appropriate materials from a wide variety of projects and topics. These materials were compiled across the SERC site, showcasing materials that were created for, or easily adaptable to, K12 classrooms. This resource will help support implementation of Next Generation Science Standards by assisting educators in finding innovative resources to address areas of instruction that are conceptually different than previous national and state science standards. Specifically, the K12 portal assists educators in learning about approaches that address the cross-cutting nature of science concepts, increasing students quantitative reasoning and numeracy skills, incorporating technology such as GIS in the classroom, and by assisting educators of all levels of K12 instruction in using relevant and meaningful ways to teach science concepts. The K12 portal supports educators by providing access to hundreds of teaching activities covering a wide array of science topics and grade levels many of which have been rigorously reviewed for pedagogic quality and scientific accuracy. The portal also provides access to web pages that enhance teaching practices that help increase student's system thinking skills, make lectures interactive, assist instructors in conducting safe and effective indoor and outdoor labs, providing support for teaching energy and climate literacy principles, assisting educators in addressing controversial content, provide guidance in engaging students affective domain, and provides a collection of tools for making teaching relevant in 21st century classrooms including using GIS, Google Earth, videos, visualizations and simulations to model and describe scientific concepts. The portal also provides access to material for specific content and audiences by (1) Supporting AGIs 'Map your World' week to specifically highlight teaching

  8. [Carcinogenesis and its mechanism of mutant-type[12Asp]K-ras4B gene].

    PubMed

    Gui, Li-ming; Wei, Li-hui; Zhang, Ying-mei; Wang, Jian-liu; Wang, Ying; Chen, Ying; Ma, Da-long

    2002-01-01

    Ras gene plays an important role in the extra- and intra-cellular signal transduction pathway. It mediates series cascade reactions, and eventually actives transcriptional factors in nucleus. It is unknown on the mechanism of carcinogenesis of Ras gene in endometrial carcinoma, though K-ras mutant is very common in endometrial atypical hyperplasia and carcinoma. On basis of discovering the mutation in 12th codon of K-ras in endometrial carcinoma cell line, HEC-1A, we explored the carcinogenesis and molecular mechanism of mutant-type [12Asp] K-ras4B gene. (1) Full-length [12Asp]K-ras4B cDNA was amplified with RT-PCR, then inserted into pcDI eukaryotic expressive vector. (2) Morphological change, growth kinetics in vitro and tumorigencity in nude mice in vivo after-before transfection were observed. (3) To test the cell growth kinetics by methyl thiazolium tetrazolium (MTT) and [3H]thymidine incorporation method. (1) The authors have successfully constructed eukaryotic expression plasmid pcDI-[12Asp] K-ras4B; (2) To confirm that [12Asp] K-ras4B mutant can trigger the neoplastic transformation of NIH3T3 cells by test in vitro and in vivo. (3) After pMCV-RasN17 plasmid, a Ras mutant were transfected into pcDI-[12Asp] K-ras4B cells, the growth of this cell were restrained significantly in comparison with control group. (4) These findings indicate the expression of RafS621A resulted in remarkable inhibition in proliferation of pcDI-[12Asp]K-ras4B cell (P < 0.05). However, RafCAAX mutant can enhance pcDI-[12Asp]K-ras4B cell growth (P < 0.05). (1) [12Asp]K-ras4B gene alone is able to cause neoplastic transformation in NIH3T3 cells in vitro and in vivo. (2) [12Asp]K-ras4B-induced NIH3T3 cells neoplastic transformation required Raf signaling pathway.

  9. Enriching K-12 Science and Mathematics Education Using LEGOs

    ERIC Educational Resources Information Center

    Williams, Keeshan; Igel, Irina; Poveda, Ronald; Kapila, Vikram; Iskander, Magued

    2012-01-01

    This paper presents a series of illustrative LEGO Mindstorms-based science and math activities, developed under an NSF GK-12 Fellows project, for elementary, middle, and high school grades. The activities, developed by engineering and science graduate Fellows in partnership with K-12 teachers, are grade appropriate, address pertinent learning…

  10. A Critique of the Brave New World of K-12 Education

    ERIC Educational Resources Information Center

    Salmani Nodoushan, Mohammad Ali

    2008-01-01

    Over the past few decades life style has changed so rapidly that remote areas of the Earth are now inhabited by human beings. Technology has also developed and people can stay at home and have access to virtual schools. This has stimulated the need for K-12 Education. K-12 education has emerged from the no-child-left-behind concerns of governments…

  11. Approaching K-12 Online Education in Pennsylvania

    ERIC Educational Resources Information Center

    Vadell, Kathryn

    2013-01-01

    The purpose of this study is to determine how K-12 schools are addressing the need to accommodate online learners in Pennsylvania. It is built upon a review of literature focusing on educational legislation, the personalization of online learning and online learning solutions. The study posed 21 questions utilizing a mixed methods approach to…

  12. SENDIT: North Dakota's K-12 Telecommunications Network.

    ERIC Educational Resources Information Center

    Sackman, Gleason

    SENDIT is a telecommunications network for North Dakota educators and students in the K-12 environment. Through SENDIT, both teachers and students have access to the Internet, and some of the isolation associated with the rurality of North Dakota has been diminished. SENDIT was developed by the North Dakota State University School of Education and…

  13. Reading: Exceptional Child Education Curriculum K-12.

    ERIC Educational Resources Information Center

    Biddle, Candace Thornton; And Others

    This K-12 reading curriculum for exceptional child education is arranged in a format comparable to the general education curriculum, and is sequenced in the order in which most children learn. The curriculum begins with a list of 123 objectives of the reading program. The objectives cover the areas of perceptual skills, word attack, structural…

  14. Ballot Measures Reflect K-12 Funding Jitters

    ERIC Educational Resources Information Center

    Klein, Alyson

    2010-01-01

    In an election year dominated by the pitched battle for Congress and major governors' races, state ballot measures involving education are largely tied to a similar theme: the burden of funding K-12 programs when state finances are shaky. In some cases, initiatives, constitutional amendments, and other ballot measures seek to tap new sources of…

  15. Virtual K-12 Leadership: A Postmodern Paradigm

    ERIC Educational Resources Information Center

    Tucker, Tommy N.

    2014-01-01

    This phenomenological, mixed-method study compared and contrasted virtual K-12 school leadership with traditional face-to-face leadership. All 106 participants served for a minimum of two years in each setting. The study was conducted in two phases in order to reveal consensus and dissensus points of view. Conceptually, a postmodern framework was…

  16. Assessing the role of clay authigenesis in the seawater potassium cycle: A paired K and Mg isotope study of deep-sea pore fluids

    NASA Astrophysics Data System (ADS)

    Santiago Ramos, D. P.; Higgins, J. A.

    2017-12-01

    In situ formation of clays (clay authigenesis) in marine sediments and altered oceanic crust is an important sink of a number of seawater cations. In particular, clay authigenesis is a major, and yet unconstrained, flux in the global seawater potassium cycle. Potassium is the fourth most abundant cation in the ocean, which constitutes an isotopically enriched K reservoir (δ41K 0‰) compared to the solid Earth (δ41K -0.5‰). Understanding what processes control this isotopic offset is the main goal of this study. Here we use a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) to measure the K and Mg isotope ratios (41K/39K and 26Mg/24Mg) of deep-sea pore fluids in order to assess the effects of clay formation in the K isotope composition of seawater. Mg isotopes are used as an independent proxy for clay formation, since marine authigenic clays are isotopically distinct from their detrital counterpart, an abundant component of marine sediments. Our study sites (ODP/IODP 1052, U1378, U1395, U1403) vary in location, lithology, age and sedimentation rates; however, pore-fluids from all sites show decreasing K concentrations with depth, suggesting potassium uptake into the sediments. We find that although K concentration trends are similar across all sites, measured δ41K values vary significantly. Results from 1-D diffusion-advection-reaction models suggest that these differences in isotopic profiles arise from a complex interplay between sedimentation rate and K isotopic fractionation during clay formation, aqueous K diffusion and ion exchange reactions. Further, model simulations yield fractionation factors between 0.9980 and 1.0000 for clay formation in deep-sea sediments. Despite the minor contribution of these deep-sea pore-fluids as sinks of seawater K, the processes responsible for K isotope fractionation in our study sites (clay formation and aqueous K diffusion) are also observed at shallow marine systems (major K sinks) and are thus

  17. Scientists Involved in K-12 Education

    NASA Astrophysics Data System (ADS)

    Robigou, V.

    2004-12-01

    The publication of countless reports documenting the dismal state of science education in the 1980s, and the Third International Mathematics and Science Study (TIMMS) report (1996) called for a wider involvement of the scientific community in K-12 education and outreach. Improving science education will not happen without the collaboration of educators and scientists working in a coordinated manner and it requires a long-term, continuous effort. To contribute effectively to K-12 education all scientists should refer to the National Science Education Standards, a set of policies that guide the development of curriculum and assessment. Ocean scientists can also specifically refer to the COSEE recommendations (www.cosee.org) that led to the creation of seven regional Centers for Ocean Sciences Education Excellence. Scientists can get involved in K-12 education in a multitude of ways. They should select projects that will accommodate time away from their research and teaching obligations, their talent, and their interest but also contribute to the education reform. A few examples of effective involvement are: 1) collaborating with colleagues in a school of education that can lead to better education of all students and future teachers, 2) acting as a resource for a national program or a local science fair, 3) serving on the advisory board of a program that develops educational material, 4) speaking out at professional meetings about the value of scientists' involvement in education, 5) speaking enthusiastically about the teaching profession. Improving science education in addition to research can seem a large, overwhelming task for scientists. As a result, focusing on projects that will fit the scientist's needs as well as benefit the science reform is of prime importance. It takes an enormous amount of work and financial and personnel resources to start a new program with measurable impact on students. So, finding the right opportunity is a priority, and stepping

  18. Temperature-dependent elasticity of Pb [(Mg0.33Nb0.67 ) 1 -xT ix ] O3

    NASA Astrophysics Data System (ADS)

    Tennakoon, Sumudu; Gladden, Joseph; Mookherjee, Mainak; Besara, Tiglet; Siegrist, Theo

    2017-10-01

    Relaxor ferroelectric materials, such as Pb [(Mg0.33Nb0.67 ) 1 -xT ix ] O3 (PMN-PT) with generic stoichiometry, undergo a ferroelectric-to-paraelectric phase transition as a function of temperature. The exact transition characterized by Curie temperature (Tc) varies as a function of chemistry (x ), i.e., the concentration of Ti. In this study, we investigated the structural phase transition by exploring the temperature dependence of the single-crystal elastic properties of Pb [(Mg0.33Nb0.67 ) 0.7T i0.3 ] O3 , i.e., x ≈0.3 . We used resonant ultrasound spectroscopy to determine the elasticity at elevated temperatures, from which Tc=398 ±5 K for PMN-PT (x ≈0.3 ) was determined. We report the full elastic constant tensor (Ci j={ C11,C12,C44 }), acoustic attenuation (Q-1), longitudinal (VP) and shear (VS) sound velocities, and elastic anisotropy of PMN-PT as a function of temperature for 400 K . Temperature trends of the elastic constants C11,C44 and bulk modulus indicate that at T >Tc the material first stiffens and reaches maxima in the vicinity of the Burns temperature (Tb˜673 K ), followed by a more typical gradual softening of the elastic constants. Similar temperature-dependent anomalies are also observed with anisotropy and Q-1, with minima in the vicinity of Tb. We used the temperature dependence of Ci j, Q-1, VP,VS , and anisotropy to infer the evolution of polar nanoregions as the material evolved from T >Tc .

  19. Web Connects K-12 Students with Scientists

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2009-01-01

    This article reports that Derek Cummings and Justin Lessler, Johns Hopkins University epidemiologists, have come to the Johns Hopkins Center for Talented Youth (CTY) to give a live webinar on the spread of swine flu. This web-based audio and video presentation is one of many efforts by universities and science organizations to put K-12 students in…

  20. Population pharmacokinetics of ϵ-aminocaproic acid in adolescents undergoing posterior spinal fusion surgery.

    PubMed

    Stricker, P A; Gastonguay, M R; Singh, D; Fiadjoe, J E; Sussman, E M; Pruitt, E Y; Goebel, T K; Zuppa, A F

    2015-04-01

    Despite demonstrated efficacy of ϵ-aminocaproic acid (EACA) in reducing blood loss in adolescents undergoing spinal fusion, there are no population-specific pharmacokinetic data to guide dosing. The aim of this study was to determine the pharmacokinetics of EACA in adolescents undergoing spinal fusion surgery and make dosing recommendations. Twenty children ages 12-17 years were enrolled, with 10 children in each of two groups based on diagnosis (idiopathic scoliosis or non-idiopathic scoliosis). Previously reported data from infants undergoing craniofacial surgery were included in the model to enable dosing recommendations over a wide range of weights, ages, and diagnoses. A population non-linear mixed effects modelling approach was used to characterize EACA pharmacokinetics. Population pharmacokinetic parameters were estimated using a two-compartment disposition model with allometrically scaled weight and an age effect on clearance. Pharmacokinetic parameters for the typical patient were a plasma clearance of 153 ml min(-1) 70 kg(-1) (6.32 ml min(-1) kg(-0.75)), intercompartmental clearance of 200 ml min(-1) 70 kg(-1) (8.26 ml min(-1) kg(-0.75)), central volume of distribution of 8.78 litre 70 kg(-1) (0.13 litre kg(-1)), and peripheral volume of distribution of 15.8 litre 70 kg(-1) (0.23 litre kg(-1)). Scoliosis aetiology did not have a clinically significant effect on drug pharmacokinetics. The following dosing schemes are recommended according to patient weight: weight <25 kg, 100 mg kg(-1) loading dose and 40 mg kg(-1) h(-1) infusion; weight ≤25 kg-<50 kg, 100 mg kg(-1) loading dose and 35 mg kg(-1) h(-1) infusion; and weight ≥50 kg, 100 mg kg(-1) loading dose and 30 mg kg(-1) h(-1) infusion. An efficacy trial employing this dosing strategy is warranted. NCT01408823. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. 12 CFR Appendix K to Part 1022 - Summary of Consumer Rights

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 8 2012-01-01 2012-01-01 false Summary of Consumer Rights K Appendix K to Part 1022 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION FAIR CREDIT REPORTING (REGULATION V) Pt. 1022, App. K Appendix K to Part 1022—Summary of Consumer Rights The prescribed form for this summary is...

  2. 12 CFR Appendix K to Part 1022 - Summary of Consumer Rights

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Summary of Consumer Rights K Appendix K to Part 1022 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION FAIR CREDIT REPORTING (REGULATION V) Pt. 1022, App. K Appendix K to Part 1022—Summary of Consumer Rights The prescribed form for this summary is...

  3. 12 CFR Appendix K to Part 1022 - Summary of Consumer Rights

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 8 2013-01-01 2013-01-01 false Summary of Consumer Rights K Appendix K to Part 1022 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION FAIR CREDIT REPORTING (REGULATION V) Pt. 1022, App. K Appendix K to Part 1022—Summary of Consumer Rights The prescribed form for this summary is...

  4. The influence of excess K2O on the electrical properties of (K,Na)1/2Bi1/2TiO3 ceramics

    NASA Astrophysics Data System (ADS)

    Li, Linhao; Li, Ming; Sinclair, Derek C.

    2018-04-01

    The solid solution (KxNa0.50-x)Bi0.50TiO3 (KNBT) between Na1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 (KBT) has been extensively researched as a candidate lead-free piezoelectric material because of its relatively high Curie temperature and good piezoelectric properties, especially near the morphotropic phase boundary (MPB) at x ˜ 0.10 (20 mol. % KBT). Here, we show that low levels of excess K2O in the starting compositions, i.e., (Ky+0.03Na0.50-y)Bi0.50TiO3.015 (y-series), can significantly change the conduction mechanism and electrical properties compared to a nominally stoichiometric KNBT series (KxNa0.50-x)Bi0.50TiO3 (x-series). Impedance spectroscopy measurements reveal significantly higher bulk conductivity (σb) values for y ≥ 0.10 samples [activation energy (Ea) ≤ 0.95 eV] compared to the corresponding x-series samples which possess bandgap type electronic conduction (Ea ˜ 1.26-1.85 eV). The largest difference in electrical properties occurs close to the MPB composition (20 mol. % KBT) where y = 0.10 ceramics possess σb (at 300 °C) that is 4 orders of magnitude higher than that of x = 0.10 and the oxide-ion transport number in the former is ˜0.70-0.75 compared to <0.05 in the latter (between 600 and 800 °C). The effect of excess K2O can be rationalised on the basis of the (K + Na):Bi ratio in the starting composition prior to ceramic processing. This demonstrates the electrical properties of KNBT to be sensitive to low levels of A-site nonstoichiometry and indicates that excess K2O in KNBT starting compositions to compensate for volatilisation can lead to undesirable high dielectric loss and leakage currents at elevated temperatures.

  5. Surface reactivity and hydroxyapatite formation on Ca5MgSi3O12 ceramics in simulated body fluid

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Wang, Yaorong; Huang, Yanlin; Cheng, Han; Seo, Hyo Jin

    2017-11-01

    In this work, the new calcium-magnesium-silicate Ca5MgSi3O12 ceramic was made via traditional solid-state reaction. The bioactivities were investigated by immerging the as-made ceramics in simulated body fluid (SBF) for different time at body temperature (37 °C). Then the samples were taken to measure X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), X-ray energy-dispersive spectra (EDS), and Fourier transform infrared spectroscopy (FT-IR) measurements. The bone-like hydroxyapatite nanoparticles formation was observed on the ceramic surfaces after the immersion in SBF solutions. Ca5MgSi3O12 ceramics possess the Young's modulus and the bending strength and of 96.3 ± 1.2 GPa and 98.7 ± 2.3 MPa, respectively. The data suggest that Ca5MgSi3O12 ceramics can quickly induce HA new layers after soaking in SBF. Ca5MgSi3O12 ceramics are potential to be used as biomaterials for bone-tissue repair. The cell adherence and proliferation experiments are conducted confirming the reliability of the ceramics as a potential candidate.

  6. Multilayer MgB{sub 2} superconducting quantum interference filter magnetometers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Galan, Elias; Melbourne, Thomas; Davidson, Bruce A.

    2016-04-25

    We report two types of all-MgB{sub 2} superconductive quantum interference filter (SQIF) magnetometers that can measure absolute magnetic fields with high sensitivity. In one configuration, the SQIFs were made of 20 multilayer nonplanar all-MgB{sub 2} superconducting quantum interference devices (SQUIDs) connected in parallel with loop areas ranging in size from 0.4 to 3.6 μm{sup 2}. These devices are sensitive to magnetic fields parallel to the substrate and show a single antipeak from 3 to 16 K with a maximum transfer function of ∼16 V/T at 3 K and a field noise of ∼110 pT/Hz{sup 1/2} above 100 Hz at 10 K. In a second configuration, themore » SQIFs were made with 16 planar SQUIDs connected in parallel with loop areas ranging in size from 4 μm{sup 2} to 25 μm{sup 2} and are sensitive to the magnetic fields perpendicular to the substrate. The planar SQIF shows a single antipeak from 10 to 22 K with a maximum transfer function of 7800 V/T at 10 K and a field noise of ∼70 pT/Hz{sup 1/2} above 100 Hz at 20 K.« less

  7. Safety assessment of astaxanthin derived from engineered Escherichia coli K-12 using a 13-week repeated dose oral toxicity study and a prenatal developmental toxicity study in rats.

    PubMed

    Lin, Yin-Ju; Lin, Jian-Yu; Wang, Di-Sheng; Chen, Chien-Hao; Chiou, Ming-Hsi

    2017-07-01

    Astaxanthin is a natural carotenoid with strong antioxidant activity that has been used for decades as a nutrient/color additive and it has recently been marketed as a health supplement. Astaxanthin can be synthesized in a wide range of microalgae, yeast, and bacteria. As genes directing astaxanthin biosynthesis in various organisms have been cloned, this study assessed the safety of astaxanthin crystal produced by Escherichia coli K-12 harboring plasmids carrying astaxanthin biosynthetic genes. The astaxanthin crystal contains a total carotenoid content of 950 mg/g and an astaxanthin content of 795 mg/g. Subchronic oral toxicity and prenatal developmental toxicity of the astaxanthin in rats were conducted in accordance with the Guidelines of Health Food Safety Assessment promulgated by Food and Drug Administration of Taiwan which is based on OECD guidelines 408 and 414. Both male and female Sprague-Dawley (SD) rats (12 for each gender) receiving the astaxanthin crystal at 1.2, 240.0, or 750.0 mg/kg/day in olive oil via oral gavage for 90 days showed no changes in body weight gains, hematology and serum chemistry values and hepatic enzyme stability, organ integrity and organ weight. Except the higher food consumption observed in rats receiving 750.0 mg/g astaxanthin crystal, administration of the astaxanthin crystal to 25-27 pregnant female rats in each group throughout the period of organogenesis (G6-G15) produced no adverse effects on fetal organogenesis. Based on the results, we propose that the no-observable-adverse-effect level (NOAEL) of the astaxanthin crystal extracted from genetically modified E. coli K-12 is 750.0 mg/kg bw/day. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Outstanding Science Trade Books for Students K-12.

    ERIC Educational Resources Information Center

    Science and Children, 2002

    2002-01-01

    Introduces a list of outstanding science trade books for grade levels K-12 in the areas of Archaeology, Anthropology, Paleontology, Biography, Life Sciences, Integrated Science, Physical Science, Science Related Careers, and Technology and Engineering. Includes information on the selection process. (YDS)

  9. Green Power Partnership Top 30 K-12 Schools

    EPA Pesticide Factsheets

    The U.S. EPA's Green Power Partnership is a voluntary program designed to reduce the environmental impact of electricity generation by promoting renewable energy. On this list are the largest green power users among K-12 school partners within the GPP.

  10. Engaging Scientists in NASA Education and Public Outreach: K - 12 Formal Education

    NASA Astrophysics Data System (ADS)

    Bartolone, Lindsay; Smith, D. A.; Eisenhamer, B.; Lawton, B. L.; Universe Professional Development Collaborative, Multiwavelength; NASA Data Collaborative, Use of; SEPOF K-12 Formal Education Working Group; E/PO Community, SMD

    2014-01-01

    The NASA Science Education and Public Outreach Forums support the NASA Science Mission Directorate (SMD) and its education and public outreach (E/PO) community through a coordinated effort to enhance the coherence and efficiency of SMD-funded E/PO programs. The Forums foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present opportunities for the astronomy community to participate in collaborations supporting the NASA SMD efforts in the K - 12 Formal Education community. Members of the K - 12 Formal Education community include classroom educators, homeschool educators, students, and curriculum developers. The Forums’ efforts for the K - 12 Formal Education community include a literature review, appraisal of educators’ needs, coordination of audience-based NASA resources and opportunities, professional development, and support with the Next Generation Science Standards. Learn how to join in our collaborative efforts to support the K - 12 Formal Education community based upon mutual needs and interests.

  11. Evaluation of the National Science Foundation Graduate Teaching Fellows in K-12 Education (GK-12) Program.

    ERIC Educational Resources Information Center

    Mitchell, Julia; Levine, Roger; Gonzalez, Raquel; Bitter, Catherine; Webb, Norman; White, Paul

    The GK-12 program of the National Science Foundation is an innovative program for enriching the value of graduate and advanced undergraduate students' education while simultaneously enriching science and mathematics teaching at the K-12 level. GK-12 is a fellowship program that offers graduate students and advanced undergraduates the opportunity…

  12. Technical Feasibility Study for Zero Energy K-12 Schools

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pless, Shanti D.; Torcellini, Paul A.; Bonnema, Eric

    A simulation-based technical feasibility study was completed to show the types of technologies required to achieve ZEB status with this building type. These technologies are prioritized across the building's subsystem such that design teams can readily integrate the ideas. Energy use intensity (EUI) targets were established for U.S. climate zones such that K-12 schools can be zero-ready or can procure solar panels or other renewable energy production sources to meet the zero energy building definition. Results showed that it is possible for K-12 schools to achieve zero energy when the EUI is between 20 and 26 kBtu/ft2/yr. Temperate climates requiredmore » a smaller percentage of solar panel coverage than very hot or very cold climates. The paper provides a foundation for technically achieving zero energy schools with a vision of transforming the school construction market to mainstream zero energy buildings within typical construction budgets.« less

  13. Structure and Differentiated Electrical Characteristics of M1/2La1/2Cu3Ti4O12 (M = Li, Na, K) Ceramics Prepared by Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Liu, Zhanqing; Yang, Zupei

    2017-10-01

    New M1/2La1/2Cu3Ti4O12 (M = Li, Na, K) ceramics based on partial substitution of Li+, Na+, and K+ for La3+ in La2/3Cu3Ti4O12 (LCTO) have been prepared by a sol-gel method, and the effects of Li+, Na+, and K+ on the microstructure and electrical properties investigated in detail, revealing different results depending on the substituent. The cell parameter increased with increasing radius of the substituent ion (Li+, Na+, K+). Li1/2La1/2Cu3Ti4O12 (LLCTO) ceramic showed better frequency and temperature stability, but the dielectric constant decreased and the third abnormal dielectric peak disappeared from the dielectric temperature spectrum. Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramic exhibited higher dielectric constant and better frequency and temperature stability, and displayed the second dielectric relaxation in electric modulus plots. The performance of K1/2La1/2Cu3Ti4O12 (KLCTO) ceramic was deteriorated. These different microstructures and electrical properties may be due to the effect of different defect structures generated in the ceramic as well as grain size. This work represents the first analysis and comparison of these remarkable differences in the electrical behavior of ceramics obtained by partial substitution of Li+, Na+, and K+ for La3+ in LCTO.

  14. Isolation, crystallization in the macrogravitation field, preliminary X-ray investigation of uridine phosphorylase from Escherichia coli K-12.

    PubMed

    Mikhailov, A M; Smirnova, E A; Tsuprun, V L; Tagunova, I V; Vainshtein, B K; Linkova, E V; Komissarov, A A; Siprashvili, Z Z; Mironov, A S

    1992-03-01

    Uridine phosphorylase (UPH) from Escherichia coli K-12 has been purified to near homogeneity from a strain harbouring the udp gene, encoding UPH, on a multicopy plasmid. UPH was purified to electrophoretic homogeneity with the specific activity 230 units/mg with a recovery of 80%, yielding 120 mg of enzyme from 3g cells. Crystals of enzyme suitable for X-ray diffraction analysis were obtained in a preparative ultracentrifuge. The packing of the molecules in the crystals may be described by the space group P2(1)2(1)2(1) with the unit cell constants a = 90.4; b = 128.8; c = 136.8 A. There is one molecule per asymmetric unit, Vm = 2.4. These crystals diffract to at least 2.5-2.7 A resolution. The hexameric structure of UPH was directly demonstrated by electron microscopy study and image processing.

  15. Sol-gel synthesis of K{sub 3}InF{sub 6} and structural characterization of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Labeguerie, Jessica; Gredin, Patrick; Marrot, Jerome

    2005-10-15

    K{sub 3}InF{sub 6} is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. Themore » two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K{sub 3}InF{sub 6} by decomposition at high temperature. The crystal structure of K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} is characterized by complex anions [In(CF{sub 3}COO){sub 4}(OH{sub x}){sub 2}]{sup (5-2x)-} and isolated [CF{sub 3}COOH{sub 2-x}]{sup (x-1)-} molecules with x=2 or 1, surrounded by K{sup +} cations. The crystal structure of K{sub 3}InC{sub 12}O{sub 12}F{sub 18} is only constituted by complex anions [In(CF{sub 3}COO){sub 6}]{sup 3-} and K{sup +} cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18} were also performed at room temperature on pulverized crystals.« less

  16. K-12 Education Nonprofit Employees' Perceptions of Strategies for Recruiting and Retaining Employees

    ERIC Educational Resources Information Center

    Byrne, Tara Marie

    2013-01-01

    This qualitative study explored the key reasons individuals who work in K-12 education nonprofit organizations enter the field of K-12 nonprofit education and their motivations for doing so. The purpose of this study was to find new strategies for recruiting and retaining K-12 education nonprofit employees by examining the obstacles that exist to…

  17. Quantitative Analysis of Ca, Mg, and K in the Roots of Angelica pubescens f. biserrata by Laser-Induced Breakdown Spectroscopy Combined with Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Wang, J.; Shi, M.; Zheng, P.; Xue, Sh.; Peng, R.

    2018-03-01

    Laser-induced breakdown spectroscopy has been applied for the quantitative analysis of Ca, Mg, and K in the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan used in traditional Chinese medicine. Ca II 317.993 nm, Mg I 517.268 nm, and K I 769.896 nm spectral lines have been chosen to set up calibration models for the analysis using the external standard and artificial neural network methods. The linear correlation coefficients of the predicted concentrations versus the standard concentrations of six samples determined by the artificial neural network method are 0.9896, 0.9945, and 0.9911 for Ca, Mg, and K, respectively, which are better than for the external standard method. The artificial neural network method also gives better performance comparing with the external standard method for the average and maximum relative errors, average relative standard deviations, and most maximum relative standard deviations of the predicted concentrations of Ca, Mg, and K in the six samples. Finally, it is proved that the artificial neural network method gives better performance compared to the external standard method for the quantitative analysis of Ca, Mg, and K in the roots of Angelica pubescens.

  18. The Green Pages: Environmental Education Activities K-12.

    ERIC Educational Resources Information Center

    Clearing, 1990

    1990-01-01

    Presented are 20 science activities for students K-12. Topics include role playing, similarities between urban and forest communities, ecosystems, garbage, recycling, food production, habitats, insects, tidal zone, animals, diversity, interest groups, rivers, spaceship earth, ecological interactions, and the cost of recreation. (KR)

  19. Development of K-12 Engineering Outreach Materials

    NASA Technical Reports Server (NTRS)

    Jordan, William

    2003-01-01

    Six modules were created that can be used in K-12 classes to introduce students to what engineers can do at NASA.The purpose of this project was to create outreach materials for the classroom. To make it appealing to students, many color NASA photographs are used to illustrate NASA applications.Student experiments are described that can be performed to illustrate topics.

  20. Development of the Advanced Energy Design Guide for K-12 Schools -- 50% Energy Savings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bonnema, E.; Leach, M.; Pless, S.

    2013-02-01

    This Technical Support Document (TSD) describes the process and methodology for the development of the Advanced Energy Design Guide for K-12 School Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-K12) (ASHRAE et al. 2011a). The AEDG-K12 provides recommendations for achieving 50% whole-building energy savings in K-12 schools over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-K12 was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of Northmore » America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE).« less

  1. Development and Evaluation of Food Safety Modules for K-12 Science Education

    ERIC Educational Resources Information Center

    Chapin, Travis K.; Pfuntner, Rachel C.; Stasiewicz, Matthew J.; Wiedmann, Martin; Orta-Ramirez, Alicia

    2015-01-01

    Career and educational opportunities in food science and food safety are underrecognized by K-12 students and educators. Additionally, misperceptions regarding nature of science understanding persist in K-12 students despite being emphasized as an important component of science education for over 100 y. In an effort to increase awareness…

  2. Pyruvate kinase activity as an indicator of the level of K(+), Mg(2+), and Ca(2+) in leaves and fruits of the cucumber: the role of potassium fertilization.

    PubMed

    Ruiz, J M; Moreno, D A; Romero, L

    1999-03-01

    Little is known about the effects of K(+) fertilization on pyruvate kinase (PK) activities in cucumber (Cucumis sativus L. cv. Brunex) grown in the greenhouse on calcareous soils. Here, the effect of K rates on the concentrations of K(+), Mg(2+), and Ca(2+) and on the PK activity as a possible indicator of the levels of these cations in the leaves and fruits of cucumber plants has been studied. The treatments consisted of applications of three rates of K in the form of K(2)SO(4) (K1 = 0.075 mg mL(-)(1), K2 = 0.15 mg mL(-)(1), and K3 = 0.30 mg mL(-)(1)). In general, K(+) application in calcareous soils proved beneficial. The highest application of K(+) (K3) to the culture medium reduced, in both the leaves and fruits, the foliar concentrations of Mg(2+) and Ca(2+). These results are reflected by the lowest basal PK activities and the highest differences between the basal PK activity and activities stimulated by these two cations. The opposite effect resulted with K2, with maximal basal PK activity and minimal differences between this activity and activities stimulated by the cations, indicating a better balance in this treatment between the different cations under the experimental conditions. Finally, this trend might partly account for the highest commercial yield in plants treated with K2.

  3. Blue-wing enhancement of the chromospheric Mg II h and k lines in a solar flare

    NASA Astrophysics Data System (ADS)

    Tei, Akiko; Sakaue, Takahito; Okamoto, Takenori J.; Kawate, Tomoko; Heinzel, Petr; UeNo, Satoru; Asai, Ayumi; Ichimoto, Kiyoshi; Shibata, Kazunari

    2018-05-01

    We performed coordinated observations of AR 12205, which showed a C-class flare on 2014 November 11, with the Interface Region Imaging Spectrograph (IRIS) and the Domeless Solar Telescope (DST) at Hida Observatory. Using spectral data in the Si IV 1403 Å, C II 1335 Å, and Mg II h and k lines from IRIS and the Ca II K, Ca II 8542 Å, and Hα lines from DST, we investigated a moving flare kernel during the flare. In the Mg II h line, the leading edge of the flare kernel showed an intensity enhancement in the blue wing and a smaller intensity of the blue-side peak (h2v) than that of the red-side one (h2r). The blueshift lasted for 9-48 s with a typical speed of 10.1 ± 2.6 km s-1, which was followed by a high intensity and a large redshift with a speed of up to 51 km s-1 detected in the Mg II h line. The large redshift was a common property for all six lines, but the blueshift prior to it was found only in the Mg II lines. Cloud modeling of the Mg II h line suggests that the blue-wing enhancement with such a peak difference could have been caused by a chromospheric-temperature (cool) upflow. We discuss a scenario in which an upflow of cool plasma is lifted up by expanding hot plasma owing to the deep penetration of non-thermal electrons into the chromosphere. Furthermore, we found that the blueshift persisted without any subsequent redshift in the leading edge of the flare kernel during its decaying phase. The cause of such a long-lasting blueshift is also discussed.

  4. 5 CFR 1655.12 - Loan agreement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... information as appropriate, to the participant. (2) If the participant initiates a loan request on the TSP Web site, which cannot be completed on the Web site, the participant must print the partially completed loan agreement directly from the Web site, provide any missing information (including spouse's...

  5. 5 CFR 1655.12 - Loan agreement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... information as appropriate, to the participant. (2) If the participant initiates a loan request on the TSP Web site, which cannot be completed on the Web site, the participant must print the partially completed loan agreement directly from the Web site, provide any missing information (including spouse's...

  6. Deep-Ultraviolet Luminescence of Rocksalt-Structured Mg x Zn1-x O (x > 0.5) Films on MgO Substrates

    NASA Astrophysics Data System (ADS)

    Kaneko, Kentaro; Tsumura, Keiichi; Ishii, Kyohei; Onuma, Takayoshi; Honda, Tohru; Fujita, Shizuo

    2018-04-01

    Rocksalt-structured Mg x Zn1-x O films with Mg composition x of 0.47, 0.57, and 0.64 were grown on (100)-oriented MgO substrates using mist chemical vapor deposition. Cathodoluminescence measurements showed deep ultraviolet (DUV) emission peaking at 4.88 eV (254 nm), 5.15 eV (241 nm), and 5.21 eV (238 nm), respectively, at 12 K. The peak energies were lower than the band gap energies by ca. 1 eV, suggesting that the deep ultraviolet (DUV) emission may be recognized as near band edge luminescence but is associated with impurities, defects, or band fluctuations. The use of carbon-free precursors in the growth is suggested to eliminate carbon impurities and to improve the optical properties of Mg x Zn1-x O.

  7. The Green Pages: Environmental Education Activities K-12.

    ERIC Educational Resources Information Center

    Clearing, 1990

    1990-01-01

    Presented are 37 environmental science activities for students in grades K-12. Topics include water pollution, glaciers, protective coloration, shapes in nature, environmental impacts, recycling, creative writing, litter, shapes found in nature, color, rain cycle, waste management, plastics, energy, pH, landfills, runoff, watersheds,…

  8. The Green Pages: Environmental Education Activities K-12.

    ERIC Educational Resources Information Center

    Clearing, 1991

    1991-01-01

    Presented are 38 environmental education activities for grades K-12. Topics include seed dispersal, food chains, plant identification, sizes and shapes, trees, common names, air pollution, recycling, temperature, litter, water conservation, photography, insects, urban areas, diversity, natural cycles, rain, erosion, phosphates, human population,…

  9. Outstanding Science Trade Books for Students K-12

    ERIC Educational Resources Information Center

    Science Teacher, 2016

    2016-01-01

    Science teachers and mentors continue to be challenged to meet the high expectations of "A Framework for K-12 Science Education" and the "Next Generation Science Standards." Indeed the Framework urges teachers to help learners "[build] progressively more sophisticated explanations of natural phenomena..." while the…

  10. State P-20 Councils and Collaboration between K-12 and Higher Education

    ERIC Educational Resources Information Center

    Rippner, Jennifer A.

    2017-01-01

    For decades, numerous observers have agreed on the value of collaboration between K-12 and higher education--especially as these sectors work toward increasing college readiness and success. While most states maintain separate agencies for K-12 and higher education, many states have worked to foster collaboration through state P-20 councils.…

  11. MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.

    2014-05-01

    Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority of our experiments showed smooth monotonic increases in MgO sound speed and shock temperature with pressure from 197 to 243 GPa. The measured temperatures as well as the slopes of the pressure dependences for both temperature and sound speed were in good agreement with those calculated numerically for the solid phase at our peak shock compression conditions. Most observed sound speeds, however, were ~800 m/s higher than those predicted by the model. A single unconfirmed data point at 239 GPa showed anomalously low temperature and sound speed, which could both be explained by partial melting in this experiment and could suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line just slightly above 240 GPa.

  12. K-Ras Populates Conformational States Differently from Its Isoform H-Ras and Oncogenic Mutant K-RasG12D.

    PubMed

    Parker, Jillian A; Volmar, Alicia Y; Pavlopoulos, Spiro; Mattos, Carla

    2018-06-05

    Structures of wild-type K-Ras from crystals obtained in the presence of guanosine triphosphate (GTP) or its analogs have remained elusive. Of the K-Ras mutants, only K-RasG12D and K-RasQ61H are available in the PDB representing the activated form of the GTPase not in complex with other proteins. We present the crystal structure of wild-type K-Ras bound to the GTP analog GppCH 2 p, with K-Ras in the state 1 conformation. Signatures of conformational states obtained by one-dimensional proton NMR confirm that K-Ras has a more substantial population of state 1 in solution than H-Ras, which predominantly favors state 2. The oncogenic mutant K-RasG12D favors state 2, changing the balance of conformational states in favor of interactions with effector proteins. Differences in the population of conformational states between K-Ras and H-Ras, as well as between K-Ras and its mutants, can provide a structural basis for focused targeting of the K-Ras isoform in cancer-specific strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Changes in K-12 Education: Implications for the BC Post-Secondary System

    ERIC Educational Resources Information Center

    McQuarrie, Fiona A. E.

    2016-01-01

    It is generally assumed by educators that the K-12 curriculum--the curriculum used in primary, elementary, and secondary education--will affect students' post-secondary educational experiences and their ability to enter the workforce. This report takes a multi-faceted approach to addressing the impact of changes in the K-12 curriculum on students'…

  14. Generic vs. Modality-Specific Competencies for K-12 Online and Blended Teaching

    ERIC Educational Resources Information Center

    Pulham, Emily B.; Graham, Charles R.; Short, Cecil R.

    2018-01-01

    Although research has explored teacher competencies in K-12 blended and online learning, it has not specified which competencies are appropriate to an online or digital medium, which refer to blending in-person with online experiences, or which are generic--applicable in any teaching modality. This article explores selected K-12 online and blended…

  15. Review of the National Research Council's Framework for K-12 Science Education

    ERIC Educational Resources Information Center

    Gross, Paul R.

    2011-01-01

    The new "Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas" is a big, comprehensive volume, carefully organized and heavily documented. It is the long-awaited product of the Committee on a Conceptual Framework for New K-12 Science Education Standards. As noted, it is a weighty document (more than 300…

  16. K-12 Online Learning and the Training Needs for School Psychology Practitioners

    ERIC Educational Resources Information Center

    Tysinger, P. Dawn; Tysinger, Jeff; Diamanduros, Terry; Kennedy, Kathryn

    2013-01-01

    K-12 online learning is growing at an exponential rate in the United States and around the world. Students and teachers are entering and embracing the K-12 online learning environment. Thus, it becomes imperative for school psychologists to follow. In order to offer the most productive learning environment for all students, the services provided…

  17. THE FORMATION OF IRIS DIAGNOSTICS. II. THE FORMATION OF THE Mg II h and k LINES IN THE SOLAR ATMOSPHERE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leenaarts, J.; Pereira, T. M. D.; Carlsson, M.

    NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h and k lines as well as a slit-jaw imager centered at Mg II k. Understanding the observations requires forward modeling of Mg II h and k line formation from three-dimensional (3D) radiation-magnetohydrodynamic (RMHD) models. This paper is the second in a series where we undertake this modeling. We compute the vertically emergent h and k intensity from a snapshot of a dynamic 3D RMHD model of the solar atmosphere, and investigate whichmore » diagnostic information about the atmosphere is contained in the synthetic line profiles. We find that the Doppler shift of the central line depression correlates strongly with the vertical velocity at optical depth unity, which is typically located less than 200 km below the transition region (TR). By combining the Doppler shifts of the h and k lines we can retrieve the sign of the velocity gradient just below the TR. The intensity in the central line depression is anti-correlated with the formation height, especially in subfields of a few square Mm. This intensity could thus be used to measure the spatial variation of the height of the TR. The intensity in the line-core emission peaks correlates with the temperature at its formation height, especially for strong emission peaks. The peaks can thus be exploited as a temperature diagnostic. The wavelength difference between the blue and red peaks provides a diagnostic of the velocity gradients in the upper chromosphere. The intensity ratio of the blue and red peaks correlates strongly with the average velocity in the upper chromosphere. We conclude that the Mg II h and k lines are excellent probes of the very upper chromosphere just below the TR, a height regime that is impossible to probe with other spectral lines. They also provide decent temperature and velocity diagnostics of the middle

  18. A Model Project in Career Education, K-12. Interim Report, December 1974.

    ERIC Educational Resources Information Center

    Wyoming State Dept. of Education, Cheyenne.

    The document presents an interim report of a project to establish career education programs for K-12 students in the Natrona County School District of Casper, Wyoming. Project activities were divided into: (1) career awareness, grades K-6; (2) career exploration, grades 7-9; (3) career preparation, grades 10-12; and (4) guidance. To meet the…

  19. K-12 Teachers' Perceptions of School Policy and Fear of School Violence

    ERIC Educational Resources Information Center

    Ricketts, Melissa L.

    2007-01-01

    Since the 1990s, schools have focused their attention on policies designed to improve school safety. Most researches on school violence policies have concentrated on the needs of students and administrators. This study investigated the impact of school violence policies on K-12 teachers' fear. Using self-report data from 447 K-12 teachers from a…

  20. Mapping the Terrain: Educational Leadership Field Experiences in K-12 Virtual Schools

    ERIC Educational Resources Information Center

    LaFrance, Jason A.; Beck, Dennis

    2014-01-01

    Opportunities for K-12 students to choose virtual and blended learning experiences continue to grow. All 50 states including Washington, D.C., now offer some virtual experience in K-12 education. Of these, 40 states have state virtual schools or state-led online learning initiatives. In addition, federal and state support for this type of learning…

  1. Structure, phonon properties, and order-disorder transition in the metal formate framework of [NH4][Mg(HCOO)3].

    PubMed

    Mączka, Mirosław; Pietraszko, Adam; Macalik, Bogusław; Hermanowicz, Krzysztof

    2014-01-21

    We report the synthesis, crystal structure, thermal, dielectric, IR, and Raman studies of [NH4][Mg(HCOO)3] formate. Single-crystal X-ray diffraction shows that it crystallizes in the hexagonal space group P6322, with orientationally disordered NH4(+) ions located in the cages of the network. Upon cooling, [NH4][Mg(HCOO)3] undergoes a phase transition at around 255 K to the ferroelectric P63 structure. Raman and IR spectra show a strong increase in intensity of the N-H stretching bands as well as narrowing of the bands related to the NH4(+) ions upon cooling. These changes indicate that the phase transition is due to orientational ordering of the NH4(+) ions. Analysis of the Raman data show, however, that the rotational and translational motions of NH4(+) do not freeze completely at the phase transition but exhibit further slowing down below 255 K, and the motional freezing becomes nearly complete below 140 K.

  2. Partnerships Between K-12 Schools and Universities: Who Benefits?

    NASA Astrophysics Data System (ADS)

    Regens, N.; Hall-Wallace, M. K.

    2001-05-01

    Collaborations between K-12 schools and universities for the purpose of improving science education are growing in number, but many question their effectiveness. After many years of outreach to local teachers, schools and districts, we have developed a collaboration that more effectively addresses school district goals and needs while providing university faculty and graduate students with real opportunities to contribute to science education in the schools. Funded by the NSF GK-12 program, we are working directly with school district curriculum specialists and classroom teachers to implement inquiry-based science investigations. Projects range from developing long-term research projects in middle and high school classrooms to assisting K-6 teachers in using kit-based science curriculum. As part of our program, we have gathered several types of data to document the impact of our efforts. Using surveys of knowledge and attitudes, we measured significant improvements in college student's knowledge and attitudes about inquiry teaching methods and the K-12 education system. Through analysis of the college student's journals, we have also documented critical elements of an effective collaboration. These journals, combined with evaluations by classroom teachers, provide evidence of how the program impacts the graduate students professionally. We have also surveyed classroom teachers to measure the impact of the college students on their attitudes about teaching science and the long-term impact of the collaboration on their classroom teaching.

  3. A Coordinated Development Program for K-12 Schools.

    ERIC Educational Resources Information Center

    White, George; Morgan, Nicholas

    1992-01-01

    Given the lean times in education today, a coordinated fund-raising effort could highly benefit public K-12 education. An office of development could coordinate grant writing, interaction with foundations, corporate partnerships, the development of endowed chairs, and individual fund raising and manage local fund raisers. Development follows three…

  4. West Bloomfield Schools Social Studies Curriculum K-12.

    ERIC Educational Resources Information Center

    Morse, James E.; And Others

    The curriculum guide outlines behavioral objectives, learning activities, evaluation methods, and resources to help K-12 classroom teachers develop and implement social studies programs. Major objectives are to extend knowledge, develop skills to make effective use of this knowledge, and to facilitate the socialization process. The first section…

  5. Foreign Language K-12. Program Evaluation 1991-92.

    ERIC Educational Resources Information Center

    Wadden, Jerry M.

    The Des Moines (Iowa) Public Schools foreign language program for K-12 is described and evaluated. The evaluation report focuses on six areas, including: (1) school district mission and philosophy of foreign language instruction; (2) context (state policies and standards, foreign language program overview and enrollment, fiber-optic communication…

  6. Outstanding Science Trade Books for Students K-12.

    ERIC Educational Resources Information Center

    Science Scope, 2002

    2002-01-01

    Presents a list of outstanding science trade books published in 2001 for use in the K-12 grade levels. Includes the areas of archaeology, anthropology, and paleontology; biography; life sciences; integrated science; physical sciences; science related careers; and technology and engineering. Provides information on the books and the selection…

  7. Note: High-power piezoelectric transformer fabricated with ternary relaxor ferroelectric Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3 single crystal.

    PubMed

    Wang, Qing; Ma, Chuanguo; Wang, Feifei; Liu, Bao; Chen, Jianwei; Luo, Haosu; Wang, Tao; Shi, Wangzhou

    2016-03-01

    A plate-shaped piezoelectric transformer was designed and fabricated using ternary relaxor ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3. Both the input and output sections utilized the transverse-extensional vibration mode. The frequency and load dependences of the electrical properties for the proposed transformer were systematically studied. Results indicated that under a matching load resistance of 14.9 kΩ, a maximum output power of 2.56 W was obtained with the temperature rise less than 5 °C. The corresponding power density reached up to 50 W/cm(3). This ternary single-crystal transformer had potential applications in compact-size converters requiring high power density.

  8. Seven gene deletions in seven days: Fast generation of Escherichia coli strains tolerant to acetate and osmotic stress

    PubMed Central

    Jensen, Sheila I.; Lennen, Rebecca M.; Herrgård, Markus J.; Nielsen, Alex T.

    2015-01-01

    Generation of multiple genomic alterations is currently a time consuming process. Here, a method was established that enables highly efficient and simultaneous deletion of multiple genes in Escherichia coli. A temperature sensitive plasmid containing arabinose inducible lambda Red recombineering genes and a rhamnose inducible flippase recombinase was constructed to facilitate fast marker-free deletions. To further speed up the procedure, we integrated the arabinose inducible lambda Red recombineering genes and the rhamnose inducible FLP into the genome of E. coli K-12 MG1655. This system enables growth at 37 °C, thereby facilitating removal of integrated antibiotic cassettes and deletion of additional genes in the same day. Phosphorothioated primers were demonstrated to enable simultaneous deletions during one round of electroporation. Utilizing these methods, we constructed strains in which four to seven genes were deleted in E. coli W and E. coli K-12. The growth rate of an E. coli K-12 quintuple deletion strain was significantly improved in the presence of high concentrations of acetate and NaCl. In conclusion, we have generated a method that enables efficient and simultaneous deletion of multiple genes in several E. coli variants. The method enables deletion of up to seven genes in as little as seven days. PMID:26643270

  9. Education Imperatives for Ohio: K-12 Policy Priorities for the Next Biennium

    ERIC Educational Resources Information Center

    Thomas B. Fordham Foundation, 2010

    2010-01-01

    For the past two decades, lawmakers from both parties in Ohio have invested heavily in the public education sector. As a consequence, total K-12 education funding, measured in constant dollars, has grown by over 60 percent since 1997, even as Ohio's K-12 student enrollment has shrunk by more than 24,000 students (1.4 percent) during that same…

  10. Motility of Escherichia coli in a quasi-two-dimensional porous medium.

    PubMed

    Sosa-Hernández, Juan Eduardo; Santillán, Moisés; Santana-Solano, Jesús

    2017-03-01

    Bacterial migration through confined spaces is critical for several phenomena, such as biofilm formation, bacterial transport in soils, and bacterial therapy against cancer. In the present work, E. coli (strain K12-MG1655 WT) motility was characterized by recording and analyzing individual bacterium trajectories in a simulated quasi-two-dimensional porous medium. The porous medium was simulated by enclosing, between slide and cover slip, a bacterial-culture sample mixed with uniform 2.98-μm-diameter spherical latex particles. The porosity of the medium was controlled by changing the latex particle concentration. By statistically analyzing several trajectory parameters (instantaneous velocity, turn angle, mean squared displacement, etc.), and contrasting with the results of a random-walk model developed ad hoc, we were able to quantify the effects that different obstacle concentrations have upon bacterial motility.

  11. Intergovernmental Approaches for Strengthening K-12 Accountability Systems

    ERIC Educational Resources Information Center

    Armour-Garb, Allison, Ed.

    2007-01-01

    This volume contains an edited transcript of the Rockefeller Institute's October 29, 2007 symposium (Chicago, IL) entitled "Intergovernmental Approaches to Strengthen K-12 Accountability Systems" as well as a framework paper circulated in preparation for the symposium. The transcript begins with a list of the forty state and federal education…

  12. Language Arts: Exceptional Child Education Curriculum K-12.

    ERIC Educational Resources Information Center

    Curran, Teresa; And Others

    The Exceptional Child Education (ECE) program of Jefferson County Public Schools in Louisville, Kentucky, presents this language arts curriculum for use with K-12 students who have learning problems. The ECE program uses the curriculum and materials of the general education program whenever appropriate, but has access to special instructional…

  13. Connecting K-12 Schools to the Information Superhighway.

    ERIC Educational Resources Information Center

    McKinsey & Co., Inc., Washington, DC.

    This report summarizes an analysis of options for connecting the nation's public K-12 schools to the national information infrastructure (NII)--or information superhighway. It incorporates insights drawn from visits to schools and interviews with educators, policymakers, and technology experts around the country, as well as from a review of the…

  14. K-Ras(G12D)-selective inhibitory peptides generated by random peptide T7 phage display technology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sakamoto, Kotaro; Kamada, Yusuke; Sameshima, Tomoya

    Amino-acid mutations of Gly{sup 12} (e.g. G12D, G12V, G12C) of V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras), the most promising drug target in cancer therapy, are major growth drivers in various cancers. Although over 30 years have passed since the discovery of these mutations in most cancer patients, effective mutated K-Ras inhibitors have not been marketed. Here, we report novel and selective inhibitory peptides to K-Ras(G12D). We screened random peptide libraries displayed on T7 phage against purified recombinant K-Ras(G12D), with thorough subtraction of phages bound to wild-type K-Ras, and obtained KRpep-2 (Ac-RRCPLYISYDPVCRR-NH{sub 2}) as a consensus sequence. KRpep-2 showedmore » more than 10-fold binding- and inhibition-selectivity to K-Ras(G12D), both in SPR analysis and GDP/GTP exchange enzyme assay. K{sub D} and IC{sub 50} values were 51 and 8.9 nM, respectively. After subsequent sequence optimization, we successfully generated KRpep-2d (Ac-RRRRCPLYISYDPVCRRRR-NH{sub 2}) that inhibited enzyme activity of K-Ras(G12D) with IC{sub 50} = 1.6 nM and significantly suppressed ERK-phosphorylation, downstream of K-Ras(G12D), along with A427 cancer cell proliferation at 30 μM peptide concentration. To our knowledge, this is the first report of a K-Ras(G12D)-selective inhibitor, contributing to the development and study of K-Ras(G12D)-targeting drugs. - Highlights: • The first K-Ras(G12D)-selective inhibitory peptides were generated. • These peptides showed more than 10-fold binding- and inhibition-selectivity to K-Ras(G12D) in compared to wild type K-Ras. • The peptide KRpep-2d suppressed downstream signal of K-Ras(G12D) and cell proliferations of cancer cell line A427.« less

  15. Identification and characterization of Escherichia coli RS218-derived islands in the pathogenesis of E. coli meningitis.

    PubMed

    Xie, Yi; Kolisnychenko, Vitaliy; Paul-Satyaseela, Maneesh; Elliott, Simon; Parthasarathy, Geetha; Yao, Yufeng; Plunkett, Guy; Blattner, Frederick R; Kim, Kwang Sik

    2006-08-01

    Escherichia coli K1 is the most common gram-negative bacterium causing neonatal meningitis, but the mechanisms by which E. coli K1 causes meningitis are not clear. We identified 22 E. coli RS218-derived genomic islands (RDIs), using a comparative genome analysis of meningitis-causing E. coli K1 strain RS218 (O18:K1:H7) and laboratory K-12 strain MG1655. Series of RDI deletion mutants were constructed and examined for phenotypes relevant to E. coli K1 meningitis. We identified 9 RDI deletion mutants (RDI 1, 4, 7, 12, 13, 16, 20, 21, and 22) that exhibited defects in meningitis development. RDI 16 and 21 mutants had profound defects in the induction of a high level of bacteremia in neonatal rats, and RDI 4 mutants exhibited a moderate defect in the induction of bacteremia. RDI 1 and 22 mutants showed defects in the ability to invade human brain microvascular endothelial cells (HBMECs), and RDI 12 mutants were defective in the ability to bind to HBMECs. RDI 13 and 20 mutants were defective in the ability to both bind to and invade HBMECs. RDI 7 mutants were defective in the induction of bacteremia and in the ability to both bind to and invade HBMECs. These results provide a framework for the future discovery and analysis of bacteremia and meningitis caused by E. coli K1 strain RS218.

  16. Efficient production of free fatty acids from ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate.

    PubMed

    Mi, Le; Qin, Dandan; Cheng, Jie; Wang, Dan; Li, Sha; Wei, Xuetuan

    2017-03-01

    Two engineered Escherichia coli strains, DQ101 (MG1655 fadD - )/pDQTES and DQ101 (MG1655 fadD - )/pDQTESZ were constructed to investigate the free fatty acid production using ionic liquid-based acid- or enzyme-catalyzed bamboo hydrolysate as carbon source in this study. The plasmid, pDQTES, carrying an acyl-ACP thioesterase 'TesA of E. coli in pTrc99A was constructed firstly, and then (3R)-hydroxyacyl-ACP dehydratase was ligated after the TesA to give the plasmid pDQTESZ. These two strains exhibited efficient fatty acid production when glucose was used as the sole carbon source, with a final concentration of 2.45 and 3.32 g/L, respectively. The free fatty acid production of the two strains on xylose is not as efficient as that on glucose, which was 2.32 and 2.96 g/L, respectively. For mixed sugars, DQ101 (MG1655 fadD - )-based strains utilized glucose and pentose sequentially under the carbon catabolite repression (CCR) regulation. The highest total FFAs concentration from the mixed sugar culture reached 2.81 g/L by DQ101 (MG1655 fadD - )/pDQTESZ. Furthermore, when ionic liquid-based enzyme-catalyzed bamboo hydrolysate was used as the carbon source, the strain DQ101 (MG1655 fadD - )/pDQTESZ could produce 1.23 g/L FFAs with a yield of 0.13 g/g, and while it just produced 0.65 g/L free fatty acid with the ionic liquid-based acid-catalyzed bamboo hydrolysate as the feedstock. The results suggested that enzymatic catalyzed bamboo hydrolysate with ionic liquid pretreatment could serve as an efficient feedstock for free fatty acid production.

  17. 17 CFR 201.550 - Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... to Exchange Act Section 12(k)(1)(A). 201.550 Section 201.550 Commodity and Securities Exchanges... Suspensions § 201.550 Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A). (a) Petition for termination of suspension. Any person adversely affected by a suspension pursuant to Section 12(k)(1)(A) of...

  18. 17 CFR 201.550 - Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... to Exchange Act Section 12(k)(1)(A). 201.550 Section 201.550 Commodity and Securities Exchanges... Suspensions § 201.550 Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A). (a) Petition for termination of suspension. Any person adversely affected by a suspension pursuant to Section 12(k)(1)(A) of...

  19. 17 CFR 201.550 - Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... to Exchange Act Section 12(k)(1)(A). 201.550 Section 201.550 Commodity and Securities Exchanges... Suspensions § 201.550 Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A). (a) Petition for termination of suspension. Any person adversely affected by a suspension pursuant to Section 12(k)(1)(A) of...

  20. 17 CFR 201.550 - Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... to Exchange Act Section 12(k)(1)(A). 201.550 Section 201.550 Commodity and Securities Exchanges... Suspensions § 201.550 Summary suspensions pursuant to Exchange Act Section 12(k)(1)(A). (a) Petition for termination of suspension. Any person adversely affected by a suspension pursuant to Section 12(k)(1)(A) of...

  1. K+ Transport by the OsHKT2;4 Transporter from Rice with Atypical Na+ Transport Properties and Competition in Permeation of K+ over Mg2+ and Ca2+ Ions1[C][W][OA

    PubMed Central

    Horie, Tomoaki; Brodsky, Dennis E.; Costa, Alex; Kaneko, Toshiyuki; Lo Schiavo, Fiorella; Katsuhara, Maki; Schroeder, Julian I.

    2011-01-01

    Members of class II of the HKT transporters, which have thus far only been isolated from grasses, were found to mediate Na+-K+ cotransport and at high Na+ concentrations preferred Na+-selective transport, depending on the ionic conditions. But the physiological functions of this K+-transporting class II of HKT transporters remain unknown in plants, with the exception of the unique class II Na+ transporter OsHKT2;1. The genetically tractable rice (Oryza sativa; background Nipponbare) possesses two predicted K+-transporting class II HKT transporter genes, OsHKT2;3 and OsHKT2;4. In this study, we have characterized the ion selectivity of the class II rice HKT transporter OsHKT2;4 in yeast and Xenopus laevis oocytes. OsHKT2;4 rescued the growth defect of a K+ uptake-deficient yeast mutant. Green fluorescent protein-OsHKT2;4 is targeted to the plasma membrane in transgenic plant cells. OsHKT2;4-expressing oocytes exhibited strong K+ permeability. Interestingly, however, K+ influx in OsHKT2;4-expressing oocytes did not require stimulation by extracellular Na+, in contrast to other class II HKT transporters. Furthermore, OsHKT2;4-mediated currents exhibited permeabilities to both Mg2+ and Ca2+ in the absence of competing K+ ions. Comparative analyses of Ca2+ and Mg2+ permeabilities in several HKT transporters, including Arabidopsis thaliana HKT1;1 (AtHKT1;1), Triticum aestivum HKT2;1 (TaHKT2;1), OsHKT2;1, OsHKT2;2, and OsHKT2;4, revealed that only OsHKT2;4 and to a lesser degree TaHKT2;1 mediate Mg2+ transport. Interestingly, cation competition analyses demonstrate that the selectivity of both of these class II HKT transporters for K+ is dominant over divalent cations, suggesting that Mg2+ and Ca2+ transport via OsHKT2;4 may be small and would depend on competing K+ concentrations in plants. PMID:21610181

  2. Atomic simulation of mechanical behavior of Mg in a super-lattice of nanocrystalline Mg and amorphous Mg-Al alloy

    NASA Astrophysics Data System (ADS)

    Song, H. Y.; An, M. R.; Li, Y. L.; Deng, Q.

    2014-12-01

    The mechanical properties of a super-lattice architecture composed of nanocrystalline Mg and Mg-Al amorphous alloy are investigated using molecular dynamics simulation. The results indicate that deformation mechanism of nanocrystalline Mg is obviously affected by the amorphous boundary spacing and temperature. The strength of the material increases with the decrease of amorphous boundary spacing, presenting a Hall-Petch effect at both 10 K and 300 K. A stress platform and following stiffness softening, as well as a linear strengthening in the plastic stage, are observed when the amorphous boundary spacing below 8.792 nm at 10 K. The implying reason may be that the amorphous boundary acts as the dislocations emission and absorption source. However, the second stress peak is not observed for the models at 300 K. Instead, the flow stress in plastic stage is a nearly constant value. The simulation demonstrates the emergence of the new grain, accompanied by the deformation twins and stacking faults associated with the plastic behaviors at 300 K. The general conclusions derived from this work may provide a guideline for the design of high-performance hexagonal close-packed metals.

  3. Evaluating the Performance of Online K-12 Schools

    ERIC Educational Resources Information Center

    Carpenter, Dick; Kafer, Krista; Reeser, Kelly; Shafer, Sheryl

    2015-01-01

    This article examines K-12 online student and school performance across an entire state (Colorado) in the United States through two comparisons. First, state assessment scores of students in online schools are compared to those in traditional brick and mortar schools. Second, the accountability scores of online schools are compared to those of…

  4. Supporting the K-12 Classroom through University Outreach

    ERIC Educational Resources Information Center

    Moskal, Barbara; Skokan, Catherine

    2011-01-01

    This article provides a field-based example of a series of outreach programs that have been designed in response to current recommendations found in the K-12 outreach literature. These programs begin with university mathematics and science faculty members teaching a 10-day summer workshop to elementary and middle school teachers. Following this…

  5. 2011 Census of Technology: Missouri Schools K-12

    ERIC Educational Resources Information Center

    Missouri Department of Elementary and Secondary Education, 2012

    2012-01-01

    The Census of Technology (COT) is designed to assess Missouri's continuing investment in K-12 education technologies. The COT provides important data for the Department of Elementary and Secondary Education (DESE) to share with state and national decision-makers to help advance public policy and increase public awareness and support for education…

  6. Designing GIS Learning Materials for K-12 Teachers

    ERIC Educational Resources Information Center

    Hong, Jung Eun

    2017-01-01

    Although previous studies have proven the usefulness and effectiveness of geographic information system (GIS) use in the K-12 classroom, the rate of teacher adoption remains low. The identified major barrier to its use is a lack of teachers' background and experience. To solve this limitation, many organisations have provided GIS-related teacher…

  7. Incorporating Skills into Social Studies Programs, K-12.

    ERIC Educational Resources Information Center

    Gregory, George, Ed.

    Designed to assist schools in implementing developmental skills in the social studies programs for grades K-12, this guide is divided into seven sections. The first section, a literature review, cites publications on social studies skills. Section 2 gives an interdisciplinary view of shared skills in the New York state curriculum. Three skill…

  8. A Guide to Networking for K-12 Schools.

    ERIC Educational Resources Information Center

    Northwest Regional Educational Lab., Portland, OR.

    The purpose of this guide is to provide basic networking information and planning assistance for technology coordinators and others involved in building networks for K-12 schools. The information in this guide focuses on the first few steps in the networking process. It reviews planning considerations and network design issues facing educators who…

  9. Effectiveness of barnidipine 10 or 20 mg plus losartan 50-mg combination versus losartan 100-mg monotherapy in patients with essential hypertension not controlled by losartan 50-mg monotherapy: A 12-week, multicenter, randomized, open-label, parallel-group study.

    PubMed

    Parati, Gianfranco; Giglio, Alessia; Lonati, Laura; Destro, Maurizio; Ricci, Alessandra Rossi; Cagnoni, Francesca; Pini, Claudio; Venco, Achille; Maresca, Andrea Maria; Monza, Michela; Grandi, Anna Maria; Omboni, Stefano

    2010-07-01

    Increasing the dose or adding a second antihypertensive agent are 2 possible therapeutic choices when blood pressure (BP) is poorly controlled with monotherapy. This study investigated the effectiveness and tolerability of barnidipine 10 or 20 mg added to losartan 50 mg versus losartan 100 mg alone in patients with mild to moderate essential hypertension whose BP was uncontrolled by losartan 50-mg monotherapy. This was a 12-week, multicenter, randomized, open-label, parallel-group study. Eligible patients (aged 30-74 years) had uncontrolled hypertension, defined as office sitting diastolic BP (DBP) > or =90 mm Hg and/or systolic BP (SBP) > or =140 mm Hg, and mean daytime DBP > or =85 mm Hg and/or SBP > or =135 mm Hg. All were being treated with losartan 50 mg at enrollment. After a 1-week run-in period while taking losartan 50 mg, patients were randomly assigned to 6 weeks of treatment with open-label barnidipine 10 mg plus losartan 50 mg or losartan 100-mg monotherapy. At the end of this period, patients with uncontrolled BP had barnidipine doubled to 20 mg and continued for an additional 6 weeks, whereas patients not achieving control on treatment with losartan 100 mg were discontinued. Office BP was measured at each visit, whereas 24-hour ambulatory BP monitoring (ABPM) was performed at randomization and at the final visit (ie, after 12 weeks of treatment, or at 6 weeks for patients not controlled on losartan 100 mg). The intent-to-treat population included all randomized patients who received at least one dose of study treatment and had valid ABPM recordings at baseline and the final visit. The primary end point was the change in daytime DBP between baseline and 12 weeks of treatment, compared between the combination treatment and monotherapy. Adverse events (AEs) were evaluated during each study visit. A total of 93 patients were enrolled (age range, 30-75 years; 60% [56/93] men). After the 1-week run-in period, 68 patients were randomly assigned to 6 weeks of

  10. Engineering design skills coverage in K-12 engineering program curriculum materials in the USA

    NASA Astrophysics Data System (ADS)

    Chabalengula, Vivien M.; Mumba, Frackson

    2017-11-01

    The current K-12 Science Education framework and Next Generation Science Standards (NGSS) in the United States emphasise the integration of engineering design in science instruction to promote scientific literacy and engineering design skills among students. As such, many engineering education programmes have developed curriculum materials that are being used in K-12 settings. However, little is known about the nature and extent to which engineering design skills outlined in NGSS are addressed in these K-12 engineering education programme curriculum materials. We analysed nine K-12 engineering education programmes for the nature and extent of engineering design skills coverage. Results show that developing possible solutions and actual designing of prototypes were the highly covered engineering design skills; specification of clear goals, criteria, and constraints received medium coverage; defining and identifying an engineering problem; optimising the design solution; and demonstrating how a prototype works, and making iterations to improve designs were lowly covered. These trends were similar across grade levels and across discipline-specific curriculum materials. These results have implications on engineering design-integrated science teaching and learning in K-12 settings.

  11. Prasugrel Results in Higher Decrease in High-Sensitivity C-Reactive Protein Level in Patients Undergoing Percutaneous Coronary Intervention Comparing to Clopidogrel.

    PubMed

    Hajsadeghi, Shokoufeh; Chitsazan, Mandana; Chitsazan, Mitra; Salehi, Negar; Amin, Ahmad; Bidokhti, Arash Amin; Babaali, Nima; Bordbar, Armin; Hejrati, Maral; Moghadami, Samar

    2016-01-01

    A growing body of clinical and laboratory evidence indicates that inflammation plays a crucial role in atherosclerosis. In the present study, we compared the effects of clopidogrel and prasugrel on high-sensitivity C-reactive protein (hs-CRP) in patients undergoing percutaneous coronary intervention (PCI). The present randomized, double-blind clinical trial included 120 patients who underwent PCI. Eligible patients were randomly assigned 2:1 to one of the two groups: 80 patients in the first group received clopidogrel (Plavix(®); loading dose and maintenance dose of 300 and 75 mg daily, respectively) and 40 patients in the second group received prasugrel (Effient(®); loading dose and maintenance dose of 60 and 10 mg, respectively) for 12 weeks. The hs-CRP levels between baseline and 12th week were compared. Of the 120 patients, 69 patients (57.5%) were male. Pretreatment hs-CRP level was statistically comparable in clopidogrel (median, 15.10 mg/dL; interquartile range [IQR], 9.62-23.75 mg/dL) and prasugrel groups (median, 18 mg/dL; IQR, 14.25-22 mg/dL; P = 0.06). Patients taking clopidogrel showed a significant reduction in hs-CRP level compared with the baseline values (P < 0.001). Prasugrel administration also resulted in a significant reduction in hs-CRP level (P < 0.001). A significant 73% overall reduction in the hs-CRP level was seen with prasugrel compared with 39% overall reduction in hs-CRP level with clopidogrel (P = 0.002). Prasugrel seems to be superior to clopidogrel in the reduction of hs-CRP in patients undergoing PCI.

  12. Outreach to Space Scientists Interested in K-12 Education

    NASA Technical Reports Server (NTRS)

    Morrow, Cherilynn A

    1998-01-01

    This is the final report for work on outreach to space scientists interested in k-12 education. It outlines what was accomplished during the two years of support and one year no-cost extension (October 1995-September 1998).

  13. Online System Adoption and K-12 Academic Outcomes

    ERIC Educational Resources Information Center

    Kimmons, R.

    2015-01-01

    This study seeks to understand the relationship between K-12 online system adoption (e.g., Blackboard, Edmodo, WordPress) and school-level academic achievement ratings. Utilizing a novel approach to data collection via website data extraction and indexing of all school websites in a target state in the United States (n?=?732) and merging these…

  14. Florida's Opinion on K-12 Public Education Spending

    ERIC Educational Resources Information Center

    Forster, Greg

    2006-01-01

    This scientifically representative poll of 1,200 Floridians finds that public opinion about K-12 public education spending is seriously misinformed. Floridians think public schools need more money, but the main reason is that they are badly mistaken about how much money the public schools actually get. Key findings of the study include: (1) Half…

  15. Defining Social Studies Education in Michigan (K-12).

    ERIC Educational Resources Information Center

    Michigan State Board of Education, Lansing.

    This document begins by providing some introductory guidelines on constructing a K-12 social studies program and conducting a curriculum program review and then goes on to focus on the goals and objectives for social studies education in Michigan. These are divided into three groups: knowledge; democratic values; and skills. For each of these…

  16. Using Cue Cards throughout the K-12 Curriculum

    ERIC Educational Resources Information Center

    Conderman, Greg; Hedin, Laura R.

    2015-01-01

    As a flexible instructional tool, cue cards offer support for students with and without disabilities. By providing different amounts of support, they also can be used to differentiate instruction in a variety of subject areas and grade levels. This article describes various strategies for using cue cards and includes examples from K-12 classrooms.

  17. Integrating Technology into the K-12 Music Curriculum.

    ERIC Educational Resources Information Center

    Washington Office of the State Superintendent of Public Instruction, Olympia.

    This guide is intended to provide resources for integrating technology into the K-12 music curriculum. The focus of the guide is on computer software and the use of MIDI (Musical Instrument Digital Interface) in the music classroom. The guide gives two examples of commercially available curricula that integrate technology as well as lesson plans…

  18. Designer Librarian: Embedded in K12 Online Learning

    ERIC Educational Resources Information Center

    Boyer, Brenda

    2015-01-01

    Over the past two decades, shifts in technology have altered the roles of school librarians in a multitude of ways. New rigorous standards, proliferation of devices, and steady growth of online and blended learning for the K12 market now demand librarians engage with learners in online environments. Taking an instructional design approach is the…

  19. Novel taspine derivative 12k inhibits cell growth and induces apoptosis in lung cell carcinoma.

    PubMed

    Dai, Bingling; Wang, Wenjie; Liu, Rui; Wang, Hongying; Zhang, Yanmin

    2015-03-01

    Taspine is an active compound in anticancer agent development. 12k was synthesized with taspine as lead compound bearing biphenyl scaffold and showed potent anticancer activity. Here, we investigated the effect of taspine derivative 12k on A549 lung cells. We showed that 12k not only decreased significantly A549 cell viability, A549 cell colony formation but also impaired A549 cell migration. Moreover, 12k treatment blocked cell cycle progression by increasing cell number in S phase to 42.80% for 6 μmol/L vs. 28.86% for control while decreasing cell number in G1 phase. Accordingly, this was associated with an increase protein expression of cyclin E and a decrease protein expression of cyclin D1, cyclin B1 and its associated CDK1 (cdc2). Meanwhile, we found that 12k induced A549 cell apoptosis, which was closely associated with the effect of the Bcl-2 family. Increase of Bad, Bak and Bax expression levels, decrease of Bcl-2 and Mcl-1 expression levels were observed. SiRNA knockdown of c-myc in A549 cells significantly attenuated tumor inhibition effects of 12k. In conclusion, our results demonstrate that 12k has an inhibitory effect on growth of A549 cell by inducing cell cycle arrest and apoptosis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Influence of wood-derived biochar on the compactibility and strength of silt loam soil

    NASA Astrophysics Data System (ADS)

    Ahmed, Ahmed; Gariepy, Yvan; Raghavan, Vijaya

    2017-04-01

    Biochar is proven to enhance soil fertility and increase crop productivity. Given that the influence of biochar on soil compaction remains unclear, selected physico-mechanical properties of soil amended with wood-derived biochar were assessed. For unamended silt loam, the bulk density, maximum bulk density, optimum moisture content, plastic limit, liquid limit, and plasticity index were 1.05 Mg m-3, 1.69 Mg m-3, 16.55, 17.1, 29.3, and 12.2%, respectively. The penetration resistance and shear strength of the unamended silt loam compacted in the standard compaction Proctor mold and at its optimum moisture content were 1800 kPa and 850 kPa, respectively. Results from amending the silt loam with 10% particle size ranges (0.5-212 μm) led to relative decreases of 18.1, 17.75, 66.66, and 97.4% in bulk density, maximum bulk density, penetration resistance, and shear strength, respectively; a 26.8% relative increase in optimum moisture content; along with absolute increases in plastic limit, liquid limit, and plasticity index of 5.3, 13.7, and 8.4%, respectively. While the biochar-amended silt loam soil was more susceptible to compaction, however, soil mechanical impedance enhanced.

  1. Use of tailored loading-dose clopidogrel in patients undergoing selected percutaneous coronary intervention based on adenosine diphosphate-mediated platelet aggregation.

    PubMed

    Meng, Kang; Lü, Shu-Zheng; Zhu, Hua-Gang; Chen, Xin; Ge, Chang-Jiang; Song, Xian-Tao

    2010-12-01

    Adenosine phosphate-mediated platelet aggregation is a prognostic factor for major adverse cardiac events in patients who have undergone selective percutaneous coronary interventions. This study aimed to assess whether an adjusted loading dose of clopidogrel could more effectively inhibit platelet aggregation in patients undergoing selected percutaneous coronary intervention. A total of 205 patients undergoing selected percutaneous coronary intervention were enrolled in this multicenter, prospective, randomized study. Patients receiving domestic clopidogrel (n = 104) served as the Talcom (Taijia) group; others (n = 101) received Plavix, the Plavix group. Patients received up to 3 additional 300-mg loading doses of clopidogrel to decrease the adenosine phosphate-mediated platelet aggregation index by more than 50% (the primary endpoint) compared with the baseline. The secondary endpoint was major adverse cardiovascular events at 12 months. Compared with the rational loading dosage, the tailored loading dosage better inhibited platelet aggregation based on a > 50% decrease in adenosine phosphate-mediated platelet aggregation (rational loading dosage vs. tailored loading dosage, 48% vs. 73%, P = 0.028). There was no significant difference in the eligible index between the Talcom and Plavix groups (47% vs. 49% at 300 mg; 62% vs. 59% at 600 mg; 74% vs. 72% at 900 mg; P > 0.05) based on a standard adenosine diphosphate-mediated platelet aggregation decrease of > 50%. After 12 months of follow-up, there were no significant differences in major adverse cardiac events (2.5% vs. 2.9%, P = 5.43). No acute or subacute stent thrombosis events occurred. An adjusted loading dose of clopidogrel could have significant effects on antiplatelet aggregation compared with a rational dose, decreasing 1-year major adverse cardiac events in patients undergoing percutaneous coronary interventions based on adenosine phosphate-mediated platelet aggregation with no increase in bleeding.

  2. K-12 education sector desk reference. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1998-01-01

    K-12 schools are a major energy customer. To help utility managers better analyze their business relationships with this important market segment, this reference provides background information, statistics, and other useful information. This is a reference. It is a compilation of figures, charts, and tables taken from many existing sources representing some of the best information available about K-12 schools. Analysts reviews over 2,500 pages of government and private sector documents (listed in Appendix A) to select the 100 pages included here. They made every effort to select documents likely to be useful to utility planning staff and program managers. Wherevermore » possible, specific state data have been included to help utility staff compute impacts within a service territory. Both a phone number and e-mail address have been included wherever available for each document listed in Appendix A. The report includes data on the following: energy use; federal mandates; deferred maintenance; indoor air quality; and technology in education. 21 figs., 49 tabs.« less

  3. Formability of a wrought Mg alloy evaluated by impression testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohamed, Walid; Gollapudi, Srikant; Charit, Indrajit

    This study is focused on furthering our understanding of the different factors that influence the formability of Magnesium alloys. Towards this end, formability studies were undertaken on a wrought Mg-2Zn-1Mn (ZM21) alloy. In contrast to conventional formability studies, the impression testing method was adopted here to evaluate the formability parameter, B, at temperatures ranging from 298 to 473 K. The variation of B of ZM21 with temperature and its rather limited values were discussed in the light of different deformation mechanisms such as activation of twinning, slip, grain boundary sliding (GBS) and dynamic recrystallization (DRX). It was found that themore » material characteristics such as grain size, texture and testing conditions such as temperature and strain rate, were key determinants of the mechanism of plastic deformation. A by-product of this analysis was the observation of an interesting correlation between the Zener-Hollomon parameter, Z, and the ability of Mg alloys to undergo DRX.« less

  4. Effect of phylloquinone (vitamin K1) supplementation for 12 months on the indices of vitamin K status and bone health in adult patients with Crohn's disease.

    PubMed

    O'Connor, Eibhlís M; Grealy, Geraldine; McCarthy, Jane; Desmond, Alan; Craig, Orla; Shanahan, Fergus; Cashman, Kevin D

    2014-10-14

    Although epidemiological findings support a role for vitamin K status in the improvement of bone indices in adult patients with Crohn's disease (CD), this needs to be confirmed in double-blind, randomised controlled trials (RCT) with phylloquinone (vitamin K1). By conducting two RCT, the present study aimed to first establish whether supplementation with 1000 μg of phylloquinone daily near-maximally suppresses the percentage of undercarboxylated osteocalcin in serum (%ucOC; marker of vitamin K status) in adult patients with CD currently in remission as it does in healthy adults and second determine the effect of supplementation with phylloquinone at this dose for 12 months on the indices of bone turnover and bone mass. The initial dose-ranging RCT was conducted in adult patients with CD (n 10 per group) using 0 (placebo), 1000 or 2000 μg of phylloquinone daily for 2 weeks. In the main RCT, the effect of placebo v. 1000 μg vitamin K/d (both co-administered with Ca (500 mg/d) and vitamin D3 (10 μg/d)) for 12 months (n 43 per group) on the biochemical indices of bone turnover (determined by enzyme immunoassay) and bone mass (determined by dual-energy X-ray absorptiometry) were investigated. At baseline, the mean %ucOC was 47 %, and this was suppressed upon supplementation with 1000 μg of phylloquinone daily ( - 81 %; P< 0·01) and not suppressed further by 2000 μg of phylloquinone daily. Compared with the placebo, supplementation with 1000 μg of phylloquinone daily for 12 months had no significant effect (P>0·1) on bone turnover markers or on the bone mass of the lumbar spine or femur, but modestly increased (P< 0·05) the bone mass of the total radius. Despite near maximal suppression of serum %ucOC, supplementation with 1000 μg of phylloquinone daily (with Ca and vitamin D3) had no effect on the indices of bone health in adult CD patients with likely vitamin K insufficiency.

  5. Hydrogen Storage Characteristics of Nanocrystalline and Amorphous Nd-Mg-Ni-Based NdMg12-Type Alloys Synthesized via Mechanical Milling

    NASA Astrophysics Data System (ADS)

    Zhang, Yanghuan; Shang, Hongwei; Hou, Zhonghui; Yuan, Zeming; Yang, Tai; Qi, Yan

    2016-12-01

    In this study, Mg was partially substituted by Ni with the intent of improving the hydrogen storage kinetics performance of NdMg12-type alloy. Mechanical milling technology was adopted to fabricate the nanocrystalline and amorphous NdMg11Ni + x wt pct Ni ( x = 100, 200) alloys. The effects of Ni content and milling duration on the microstructures and hydrogen storage kinetics of as-milled alloys have been systematically investigated. The structures were characterized by XRD and HRTEM. The electrochemical hydrogen storage properties were tested by an automatic galvanostatic system. Moreover, the gaseous hydrogen storage properties were investigated by Sievert apparatus and a differential scanning calorimeter connected with a H2 detector. Hydrogen desorption activation energy of alloy hydrides was estimated by using Arrhenius and Kissinger methods. The results reveal that the increase of Ni content dramatically ameliorates the gaseous and electrochemical hydrogen storage kinetics performance of the as-milled alloys. Furthermore, high rate discharge ability (HRD) reach the maximum value with the variation of milling time. The maximum HRDs of the NdMg11Ni + x wt pct Ni ( x = 100, 200) alloys are 80.24 and 85.17 pct. The improved gaseous hydrogen storage kinetics of alloys via increasing Ni content and milling time can be attributed to a decrease in the hydrogen desorption activation energy.

  6. Development of an Attitude Scale to Assess K-12 Teachers' Attitudes toward Nanotechnology

    ERIC Educational Resources Information Center

    Lan, Yu-Ling

    2012-01-01

    To maximize the contributions of nanotechnology to this society, at least 60 countries have put efforts into this field. In Taiwan, a government-funded K-12 Nanotechnology Programme was established to train K-12 teachers with adequate nanotechnology literacy to foster the next generation of Taiwanese people with sufficient knowledge in…

  7. STEM Integration in K-12 Education: Status, Prospects, and an Agenda for Research

    ERIC Educational Resources Information Center

    Honey, Margaret; Pearson, Greg; Schweingruber, Heidi

    2014-01-01

    "STEM Integration in K-12 Education" examines current efforts to connect the STEM disciplines in K-12 education. This report identifies and characterizes existing approaches to integrated STEM education, both in formal and after- and out-of-school settings. The report reviews the evidence for the impact of integrated approaches on…

  8. Diffusion coefficients of Mg isotopes in MgSiO3 and Mg2SiO4 melts calculated by first-principles molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohui; Qi, Yuhan; Zheng, Daye; Zhou, Chen; He, Lixin; Huang, Fang

    2018-02-01

    The mass dependence of diffusion coefficient (D) can be described in the form of Di/Dj = (mj/mi)β, where m denotes masses of isotope i and j, and β is an empirical parameter as used to quantify the diffusive transport of isotopes. Recent advances in computation techniques allow theoretically calculation of β values. Here, we apply first-principles Born-Oppenheimer molecular dynamics (MD) and pseudo-isotope method (taking mj/mi = 1/24, 6/24, 48/24, 120/24) to estimate β for MgSiO3 and Mg2SiO4 melts. Our calculation shows that β values for Mg calculated with 24Mg and different pseudo Mg isotopes are identical, indicating the reliability of the pseudo-isotope method. For MgSiO3 melt, β is 0.272 ± 0.005 at 4000 K and 0 GPa, higher than the value calculated using classical MD simulations (0.135). For Mg2SiO4 melt, β is 0.184 ± 0.006 at 2300 K, 0.245 ± 0.007 at 3000 K, and 0.257 ± 0.012 at 4000 K. Notably, β values of MgSiO3 and Mg2SiO4 melts are significantly higher than the value in basalt-rhyolite melts determined by chemical diffusion experiments (0.05). Our results suggest that β values are not sensitive to the temperature if it is well above the liquidus, but can be significantly smaller when the temperature is close to the liquidus. The small difference of β between silicate liquids with simple compositions of MgSiO3 and Mg2SiO4 suggests that the β value may depend on the chemical composition of the melts. This study shows that first-principles MD provide a promising tool to estimate β of silicate melts.

  9. Mechanical Properties of Mg-Gd and Mg-Y Solid Solutions

    NASA Astrophysics Data System (ADS)

    Kula, Anna; Jia, Xiaohui; Mishra, Raj K.; Niewczas, Marek

    2016-12-01

    The mechanical properties of Mg-Gd and Mg-Y solid solutions have been studied under uniaxial tension and compression between 4 K and 298 K (-269 °C and 25 °C). The results reveal that Mg-Gd alloys exhibit higher strength and ductility under tension and compression attributed to the more effective solid solution strengthening and grain-boundary strengthening effects. Profuse twinning has been observed under compression, resulting in a material texture with strong dominance of basal component parallel to compression axis. Under tension, twining is less active and the texture evolution is controlled mostly by slip. The alloys exhibit pronounced yield stress asymmetry and significantly different work-hardening behavior under tension and compression. Increasing of Gd and/or Y concentration leads to the reduction of the tension-compression asymmetry due to the weakening of the recrystallization texture and more balanced twinning and slip activity during plastic deformation. The results suggest that under compression of Mg-Y alloys slip is more active than twinning in comparison to Mg-Gd alloys.

  10. Mineralogical studies of the nitrate deposits of Chile. V. Iquiqueite, Na4K3Mg(CrO4)B24O39(OH).12H2O, a new saline mineral.

    USGS Publications Warehouse

    Ericksen, G.E.; Mrose, M.E.; Marinenko, J.W.; McGee, J.J.

    1986-01-01

    Iquiqueite (Na4K3Mg(CrO4)B24O39(OH).12H2O, a 11.6369(14), c 30.158(7) A, P31c, Z = 3) occurs as a widespread minor constituent in the nitrate fields of northern Chile. It is particularly abundant in the vicinity of Zapiga, Tarapaca province. Associated minerals include nitratite, halite, nitre, darapskite, blodite, glauberite, dietzeite, bruggenite, ulexite and gypsum. Iquiqueite forms thin, yellow, hexagonal platelets (5-50 mu m in diameter, <5 mu m in thickness) that are disseminated singly or in vermiform aggregates in nitrate ore. Observed forms are c(0001) and m(1010). Cleavage is perfect on (0001) and imperfect on (1010); H. = or <2. D(calc.) 2.05 g/cm3 and measured sp. gr. 2.05 + or - 0.09. The mineral is uniaxial negative, epsilon 1.447(2), omega 1.502(2). The XRD pattern has the six strongest lines 3.02(100), 2.856(100), 10.11(85), 6.04(85), 3.28(85), 3.22(85) A. The name is for the city of Iquique, Chile.-J.A.Z.

  11. A placebo-controlled trial of dextromethorphan as an adjunct in opioid-dependent patients undergoing methadone maintenance treatment.

    PubMed

    Lee, Sheng-Yu; Chen, Shiou-Lan; Chang, Yun-Hsuan; Chu, Chun-Hsien; Chen, Shih-Heng; Chen, Po See; Huang, San-Yuan; Tzeng, Nian-Sheng; Wang, Liang-Jen; Lee, I Hui; Wang, Tzu-Yun; Chen, Kao Chin; Yang, Yen Kuang; Hong, Jau-Shyong; Lu, Ru-Band

    2015-02-25

    Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT). Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor-β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect. After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different. We provide evidence-decreased concomitant heroin use-of low-dose add-on DM's efficacy for treating opioid-dependent patients undergoing MMT. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  12. A Placebo-Controlled Trial of Dextromethorphan as an Adjunct in Opioid-Dependent Patients Undergoing Methadone Maintenance Treatment

    PubMed Central

    Lee, Sheng-Yu; Chen, Shiou-Lan; Chang, Yun-Hsuan; Chu, Chun-Hsien; Chen, Shih-Heng; Chen, Po See; Huang, San-Yuan; Tzeng, Nian-Sheng; Wang, Liang-Jen; Lee, I Hui; Wang, Tzu-Yun; Chen, Kao Chin; Yang, Yen Kuang; Hong, Jau-Shyong

    2015-01-01

    Background: Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT). Methods: Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor–β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect. Results: After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different. Conclusions: We provide evidence—decreased concomitant heroin use—of low-dose add-on DM’s efficacy for treating opioid-dependent patients undergoing MMT. PMID:25716777

  13. Project WILD K-12 Curriculum and Activity Guide

    ERIC Educational Resources Information Center

    Council for Environmental Education, 2011

    2011-01-01

    The "Project WILD K-12 Curriculum and Activity Guide" focuses on wildlife and habitat. It is organized in topic units and is based on the Project WILD conceptual framework. Because these activities are designed for integration into existing courses of study, instructors may use one or many Project WILD activities or the entire set of activities…

  14. Skyline Gathers K-12 Together Under One Roof.

    ERIC Educational Resources Information Center

    American School Board Journal, 1968

    1968-01-01

    Skyline School is a flexible and economical elementary and high school design for 400 pupils. The library, a large resource center serving all ages, and the administration offices are accented by landscaped courts. There are two instructional material centers per grade grouping of K-6 and 7-12. Grades 1-6 surround the kindergarten, which has…

  15. Federal Support for Technology in K-12 Education

    ERIC Educational Resources Information Center

    Chapman, Gary

    2000-01-01

    The federal government has, on the whole, has done an excellent job, especially since 1996, in fostering the use of technology in K-12 public schools in the United States. The Department of Education's focus on getting computers and Internet access to low-income schools and communities is the right approach. This paper measures the impact of the…

  16. Engaging K-12 Language Learners in Media Literacy

    ERIC Educational Resources Information Center

    Egbert, Joy; Neville, Chon

    2015-01-01

    Calls to integrate media literacy into K-12 language classrooms appear to have gone largely unheeded. However, media literacy skills are seen as crucial for 21st-century learners. This article answers the calls for a focus on media literacy in the language classroom by addressing both why and how systematic attention might be brought to this issue…

  17. The shock wave equation of state of brucite Mg(OH)2

    NASA Technical Reports Server (NTRS)

    Duffy, Thomas S.; Ahrens, Thomas J.; Lange, Manfred A.

    1991-01-01

    New shock equation of state (EOS) data on magnesium hydroxide between 12 and 60 GPa is presented. It is found that the brucite EOS data between 12 and 97 GPa can be fit with a single linear U(s) - u(p) relationship: U(s) = 4.76(0.11) + 1.35(0.05)u(p). The third order Birch-Murnaghan equation parameters are K(os) = 51 + or - 4 GPa and K(os)prime = 5.0 + or - 0.4. The first partial release states measured for brucite Mg(OH)2 are reported. Calculated phase boundaries using the EOS data are found to be consistent with the experimental data and indicate that brucite is unlikely to be stable under lower mantle conditions. At high pressure, bulk sound velocities calculated for MgO and Mg(OH)2 are very similar, indicating that the presence of hydrous assemblages in the lower mantle may not produce anomalous bulk seismic velocities. A comparison of densities in brucite and other high-pressure phases under mantle conditions shows that the water content of the lower mantle is between 0 and 3 wt pct.

  18. The role of genomic islands in Escherichia coli K1 interactions with intestinal and kidney epithelial cells.

    PubMed

    Yousuf, Farzana Abubakar; Rafiq, Sahar; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2016-04-01

    The completion of Escherichia coli K1 genome has identified several genomic islands that are present in meningitis-causing E. coli RS218 but absent in the non-pathogenic E. coli MG1655. In this study, the role of various genomic islands in E. coli K1 interactions with intestinal epithelial cells (Caco-2) and kidney epithelial cells (MA104) was determined. Using association assays, invasion assays, and intracellular survival assays, the findings revealed that the genomic island deletion mutants of RS218 related to P fimbriae, S fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, protein secretion system (T1SS for hemolysin; T2SS; T5SS for antigen 43), Iro system and hmu system), invasins (CNF1, IbeA), toxins (α-hemolysin), K1 capsule biosynthesis, metabolism (d-serine catabolism, dihydroxyacetone, glycerol, and glyoxylate metabolism), prophage genes, showed reduced interactions with both cell types. Next, we determined the role of various genomic islands in E. coli K1 resistance to serum. When exposed to the normal human serum, the viability of the genomic island deletion mutants related to adhesins such as S fimbriae, P fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, antigen 43 and T5SS for antigen 43, T2SS, and T1SS for hemolysin, Iro system and hmu system, prophage genes, metabolism (sugar metabolism and d-serine catabolism), K1 capsule biosynthesis, and invasins such as CNF1 was affected, suggesting their role in bacteremia. The characterization of these genomic islands should reveal mechanisms of E. coli K1 pathogenicity that could be of value as therapeutic targets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Exploring Arizona K-12 Virtual Educator Experiences and Perspectives Developing Collaborative Learning Communities

    ERIC Educational Resources Information Center

    Cross, Deborah Iyron

    2015-01-01

    Arizona Online Instruction (AOI) provided an instructional alternative to nearly fifty thousand K-12 students in Arizona during the 2012-2013 school year. Growth in online education underscores the importance of evolving the role of the K-12 virtual teacher as the human agent (Turvey, 2008) demonstrating social learning theory (Bandura, 1977) by…

  20. In Search of the Active Site of PMMO Enzyme: Partnership between a K-12 Teacher, a Graduate K-12 Teaching Fellow, and a Research Mentor

    ERIC Educational Resources Information Center

    Bearden, Katherine K.; Mainardi, Daniela S.; Culligan, Tanya

    2009-01-01

    The partnership between a K-12 teacher (Culligan), an NSF GK-12 Teaching Fellow graduate student (Bearden), and a Louisiana Tech faculty member (Mainardi) collaborating in a research and education project is described in this work. The unique grouping of these three researchers allows for maximum dissemination of developed modules. By the end of…

  1. Finished Genome Sequence of the Laboratory Strain Escherichia coli K-12 RV308 (ATCC 31608).

    PubMed

    Krempl, Peter M; Mairhofer, Juergen; Striedner, Gerald; Thallinger, Gerhard G

    2014-11-20

    Escherichia coli strain K-12 substrain RV308 is an engineered descendant of the K-12 wild-type strain. Like its ancestor, it is an important organism in biotechnological research and is heavily used for the expression of single-chain variable fragments. Here, we report the complete genome sequence of E. coli K-12 RV308 (ATCC 31608). Copyright © 2014 Krempl et al.

  2. K-Ras(G12D)-selective inhibitory peptides generated by random peptide T7 phage display technology.

    PubMed

    Sakamoto, Kotaro; Kamada, Yusuke; Sameshima, Tomoya; Yaguchi, Masahiro; Niida, Ayumu; Sasaki, Shigekazu; Miwa, Masanori; Ohkubo, Shoichi; Sakamoto, Jun-Ichi; Kamaura, Masahiro; Cho, Nobuo; Tani, Akiyoshi

    2017-03-11

    Amino-acid mutations of Gly 12 (e.g. G12D, G12V, G12C) of V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras), the most promising drug target in cancer therapy, are major growth drivers in various cancers. Although over 30 years have passed since the discovery of these mutations in most cancer patients, effective mutated K-Ras inhibitors have not been marketed. Here, we report novel and selective inhibitory peptides to K-Ras(G12D). We screened random peptide libraries displayed on T7 phage against purified recombinant K-Ras(G12D), with thorough subtraction of phages bound to wild-type K-Ras, and obtained KRpep-2 (Ac-RRCPLYISYDPVCRR-NH 2 ) as a consensus sequence. KRpep-2 showed more than 10-fold binding- and inhibition-selectivity to K-Ras(G12D), both in SPR analysis and GDP/GTP exchange enzyme assay. K D and IC 50 values were 51 and 8.9 nM, respectively. After subsequent sequence optimization, we successfully generated KRpep-2d (Ac-RRRRCPLYISYDPVCRRRR-NH 2 ) that inhibited enzyme activity of K-Ras(G12D) with IC 50  = 1.6 nM and significantly suppressed ERK-phosphorylation, downstream of K-Ras(G12D), along with A427 cancer cell proliferation at 30 μM peptide concentration. To our knowledge, this is the first report of a K-Ras(G12D)-selective inhibitor, contributing to the development and study of K-Ras(G12D)-targeting drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The Engaged Microbiologist: Bringing the Microbiological Sciences to the K-12 Community.

    PubMed

    Westenberg, David J

    2016-03-01

    Exposing K-12 students to cutting edge science that impacts their daily lives can bring classroom lessons to life. Citizen-science projects are an excellent way to bring high-level science to the classroom and help satisfy one of the cornerstone concepts of the Next Generation Science Standards (NGSS), "engaging in practices that scientists and engineers actually use." This can be a daunting task for teachers who may lack the background or resources to integrate these projects into the classroom. This is where scientific societies such as the American Society for Microbiology (ASM) can play a critical role. ASM encourages its members to engage with the K-12 community by providing networking opportunities and resources for ASM members and K-12 teachers to work together to bring microbiology into the classroom. Journal of Microbiology & Biology Education.

  4. Involving Practicing Scientists in K-12 Science Teacher Professional Development

    NASA Astrophysics Data System (ADS)

    Bertram, K. B.

    2011-12-01

    The Science Teacher Education Program (STEP) offered a unique framework for creating professional development courses focused on Arctic research from 2006-2009. Under the STEP framework, science, technology, engineering, and math (STEM) training was delivered by teams of practicing Arctic researchers in partnership with master teachers with 20+ years experience teaching STEM content in K-12 classrooms. Courses based on the framework were offered to educators across Alaska. STEP offered in-person summer-intensive institutes and follow-on audio-conferenced field-test courses during the academic year, supplemented by online scientist mentorship for teachers. During STEP courses, teams of scientists offered in-depth STEM content instruction at the graduate level for teachers of all grade levels. STEP graduate-level training culminated in the translation of information and data learned from Arctic scientists into standard-aligned lessons designed for immediate use in K-12 classrooms. This presentation will focus on research that explored the question: To what degree was scientist involvement beneficial to teacher training and to what degree was STEP scientist involvement beneficial to scientist instructors? Data sources reveal consistently high levels of ongoing (4 year) scientist and teacher participation; high STEM content learning outcomes for teachers; high STEM content learning outcomes for students; high ratings of STEP courses by scientists and teachers; and a discussion of the reasons scientists indicate they benefited from STEP involvement. Analyses of open-ended comments by teachers and scientists support and clarify these findings. A grounded theory approach was used to analyze teacher and scientist qualitative feedback. Comments were coded and patterns analyzed in three databases. The vast majority of teacher open-ended comments indicate that STEP involvement improved K-12 STEM classroom instruction, and the vast majority of scientist open-ended comments

  5. Perspectives on...Special Collections at ARL Libraries and K-12 Outreach: Current Trends

    ERIC Educational Resources Information Center

    Visser, Michelle

    2006-01-01

    This article examines the results of a survey sent to Association of Research Libraries (ARL) Special Collections requesting information on outreach to K-12 students. Over half of the respondents work with K-12 and many of those who currently do not are planning to. New pressures and changing philosophies contribute to this trend.

  6. K-12 Teacher Perceptions Regarding the Flipped Classroom Model for Teaching and Learning

    ERIC Educational Resources Information Center

    Gough, Evan; DeJong, David; Grundmeyer, Trent; Baron, Mark

    2017-01-01

    A great deal of evidence can be cited from higher education literature on the effectiveness of the flipped classroom; however, very little research was discovered on the flipped classroom at the K-12 level. This study examined K-12 teachers' perceptions regarding the flipped classroom and differences in teachers' perceptions based on grade level…

  7. Effects of paraquat on Escherichia coli: Differences between B and K-12 strains

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kitzler, J.W.; Minakami, H.; Fridovich, I.

    1990-02-01

    Escherichia coli B and K-12 are equally susceptible to the bacteriostatic effects of aerobic paraquat, but they differed strikingly when the lethality of paraquat was evaluated. E. coli B suffered an apparent loss of viability when briefly exposed to paraquat, whereas E. coli K-12 did not. This difference depended on the ability of the B-strain, but not the K-12 strain, to retain internalized paraquat; the B strain was killed on aerobic tryptic soy-yeast extract plates during the incubation which preceded the counting of colonies. This difference in retention of paraquat between strains was demonstrated by delayed loss of viability, bymore » growth inhibition, and by cyanide-resistant respiration after brief exposure to paraquat, washing, and testing in fresh medium. This difference was also shown by using ({sup 14}C)paraquat. This previously unrecognized difference between E. coli B and K-12 has been the cause of apparently contradictory reports and should lead to some reevaluation of the pertinent literature.« less

  8. KSC-02pd1655

    NASA Image and Video Library

    2002-10-26

    KENNEDY SPACE CENTER, FLA. -- A truck containing the Solar Radiation and Climate Experiment (SORCE) spacecraft arrives at KSC. The spacecraft will undergo final processing for launch. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

  9. The dehydrogenation mechanism during the incubation period in nanocrystalline MgH2.

    PubMed

    Shantilal Gangrade, Apurva; Aditya Varma, Akhil; Kishor Gor, Nikhil; Shriniwasan, Sweta; Tatiparti, Sankara Sarma V

    2017-03-01

    The dehydrogenation mechanism during the incubation period in nanocrystalline MgH 2 (low α: converted metal fraction and dα/dt) and the reasons for the occurrence of the incubation period at 320, 350, and 400 °C were investigated. Pre-existing Mg crystallites can enhance Mg nucleation during the incubation period, as suggested by the estimated activation energy for nucleation (12 ± 2 kJ per mol H). The released H-atoms enter MgH 2 as interstitials, as indicated by the MgH 2 unit-cell contraction, resulting in increased equatorial Mg-H bond length, decreased charge-density distribution in the interstitial region, as observed from the charge-density maps, and decreased H-H distance in the {001} plane up to the midway of the incubation period. Eventually, hydrogen vacancies are created, as indicated by the red shift in the E g and A 1g peaks of Raman spectra. The high estimated activation energy for the growth of Mg (209 ± 8 kJ per mol H) renders it difficult and explains the reason for the presence of an incubation period.

  10. Reprogramming of Escherichia coli K-12 metabolism during the initial phase of transition from an anaerobic to a micro-aerobic environment.

    PubMed

    Trotter, Eleanor W; Rolfe, Matthew D; Hounslow, Andrea M; Craven, C Jeremy; Williamson, Michael P; Sanguinetti, Guido; Poole, Robert K; Green, Jeffrey

    2011-01-01

    Many bacteria undergo transitions between environments with differing O₂ availabilities as part of their natural lifestyles and during biotechnological processes. However, the dynamics of adaptation when bacteria experience changes in O₂ availability are understudied. The model bacterium and facultative anaerobe Escherichia coli K-12 provides an ideal system for exploring this process. Time-resolved transcript profiles of E. coli K-12 during the initial phase of transition from anaerobic to micro-aerobic conditions revealed a reprogramming of gene expression consistent with a switch from fermentative to respiratory metabolism. The changes in transcript abundance were matched by changes in the abundances of selected central metabolic proteins. A probabilistic state space model was used to infer the activities of two key regulators, FNR (O₂ sensing) and PdhR (pyruvate sensing). The model implied that both regulators were rapidly inactivated during the transition from an anaerobic to a micro-aerobic environment. Analysis of the external metabolome and protein levels suggested that the cultures transit through different physiological states during the process of adaptation, characterized by the rapid inactivation of pyruvate formate-lyase (PFL), a slower induction of pyruvate dehydrogenase complex (PDHC) activity and transient excretion of pyruvate, consistent with the predicted inactivation of PdhR and FNR. Perturbation of anaerobic steady-state cultures by introduction of a limited supply of O₂ combined with time-resolved transcript, protein and metabolite profiling, and probabilistic modeling has revealed that pyruvate (sensed by PdhR) is a key metabolic signal in coordinating the reprogramming of E. coli K-12 gene expression by working alongside the O₂ sensor FNR during transition from anaerobic to micro-aerobic conditions.

  11. Evaluation of beta-lactose, PVP K12 and PVP K90 as excipients to prepare piroxicam granules using two wet granulation techniques.

    PubMed

    Albertini, Beatrice; Cavallari, Cristina; Passerini, Nadia; González-Rodríguez, M L; Rodriguez, Lorenzo

    2003-11-01

    The present investigation aimed at evaluating the use of different excipients, beta-lactose and polyvinylpyrrolidone of two molecular weights (PVP K12 and PVP K90), in the production of improved release piroxicam granules, by wet granulation using both water and steam as granulation liquid. The formulations examined were: piroxicam (Px)/beta-lactose; Px/PVP K12 and Px/PVP K90, each one at a 1:9 weight ratio. The most significant difference between beta-lactose and PVP is that, using the first excipient, both steam and water granules were produced while, when PVP were employed, only steam granules were obtained. Image analysis revealed that beta-lactose steam granules had a larger surface area with respect to water granules, whereas lower values of this parameter were observed in PVP-s granules, confirming the Scanning Electron Microscopy micrographs and the fractal analysis results. As regards the enhancement of the dissolution profiles, the best result was obtained using beta-lactose steam granules followed by PVP K12 ones, even if the reactive dimension values indicated that during the dissolution process PVP K12 granules modified the surface more than beta-lactose granules. As regards PVP K90, this excipient was the one less influencing the granule morphology and the dissolution behaviour. Differential Scanning Calorimetry analysis suggested the partial amorphisation of the drug in the granules containing the three excipients. This result was then confirmed by X-ray powder diffraction analysis. Therefore, beta-lactose and PVP K12 could be proposed as useful excipients to enhance the dissolution rate of Px from granules prepared using the steam granulation technique.

  12. Virtual Schools: The Changing Landscape of K-12 Education in the U.S.

    ERIC Educational Resources Information Center

    Toppin, Ian N.; Toppin, Sheila M.

    2016-01-01

    Virtual schools are a growing phenomenon in k-12 education. School systems in almost every state in the United States offer some version of fully online or blended education. It is no longer far-fetched to conclude that if the current trend continues, virtual school enrollments will eclipse those of traditional brick-and-mortar k-12 institutions…

  13. Leadership Analysis in K-12 Case Study: "Divided Loyalties"

    ERIC Educational Resources Information Center

    Alsubaie, Merfat Ayesh

    2016-01-01

    This report mainly aims to provide a critical and in-depth analysis of the K-12 Case, "Divided Loyalty" by Holy and Tartar (2004). The case recounts how the manifestation of inadequate leadership skills in a school setting could affect negatively the performance of students.

  14. Information Security Management Practices of K-12 School Districts

    ERIC Educational Resources Information Center

    Nyachwaya, Samson

    2013-01-01

    The research problem addressed in this quantitative correlational study was the inadequacy of sound information security management (ISM) practices in K-12 school districts, despite their increasing ownership of information assets. Researchers have linked organizational and sociotechnical factors to the implementation of information security…

  15. Modern & Classical Languages: K-12 Program EValuation 1988-89.

    ERIC Educational Resources Information Center

    Martinez, Margaret Perea

    This evaluation of the modern and classical languages programs, K-12, in the Albuquerque (New Mexico) public school system provides general information on the program's history, philosophy, recognition, curriculum development, teachers, and activities. Specific information is offered on the different program components, namely, the elementary…

  16. Connecting with Teachers and Students through K-12 Outreach Activities

    NASA Astrophysics Data System (ADS)

    Chapman, Susan; Lindbo, David; Robinson, Clay

    2014-05-01

    The Soil Science Society of America has invested heavily in a significant outreach effort to reach teachers and students in the primary/secondary grades (K-12 grades in US/Canada) to raise awareness of soil as a critical resource. The SSSA K-12 committee has been charged with increasing interest and awareness of soil science as a scientific pursuit and career choice, and providing resources that integrate more information on soil science into biology, chemistry, physics, and earth science areas taught at multiple grade levels. Activities center around five main areas: assessment and standards, learning modules/lesson plans, website development, and books and materials, and partnership activities. Members (professionals and students) of SSSA are involved through committee participation, local events, materials review, and project development.

  17. Educators in Industry: An Exploratory Study to Determine How Teacher Externships Influence K-12 Classroom Practices

    ERIC Educational Resources Information Center

    Bowen, Bradley; Shume, Teresa

    2018-01-01

    This exploratory study investigates the impacts of industry-based externships for K-12 teachers, and reports teachers' perspectives on how these experiences influenced K-12 classroom practices. The program of focus in this research study is the Educators in Industry: K-12 Externship Program. For four weeks in the summer, teacher-participants are…

  18. The minor spliceosomal protein U11/U12-31K is an RNA chaperone crucial for U12 intron splicing and the development of dicot and monocot plants.

    PubMed

    Kwak, Kyung Jin; Jung, Hyun Ju; Lee, Kwang Ho; Kim, Young Soon; Kim, Won Yong; Ahn, Sung Ju; Kang, Hunseung

    2012-01-01

    U12 intron-specific spliceosomes contain U11 and U12 small nuclear ribonucleoproteins and mediate the removal of U12 introns from precursor-mRNAs. Among the several proteins unique to the U12-type spliceosomes, an Arabidopsis thaliana AtU11/U12-31K protein has been shown to be indispensible for proper U12 intron splicing and for normal growth and development of Arabidopsis plants. Here, we assessed the functional roles of the rice (Oryza sativa) OsU11/U12-31K protein in U12 intron splicing and development of plants. The U11/U12-31K transcripts were abundantly expressed in the shoot apical meristems (SAMs) of Arabidopsis and rice. Ectopic expression of OsU11/U12-31K in AtU11/U12-31K-defecient Arabidopsis mutant complemented the incorrect U12 intron splicing and abnormal development phenotypes of the Arabidopsis mutant plants. Impaired cell division activity in the SAMs and inflorescence stems observed in the AtU11/U12-31K-deficient mutant was completely recovered to normal by the expression of OsU11/U12-31K. Similar to Arabidopsis AtU11/U12-31K, rice OsU11/U12-31K was determined to harbor RNA chaperone activity. Collectively, the present findings provide evidence for the emerging idea that the U11/U12-31K protein is an indispensible RNA chaperone that functions in U12 intron splicing and is necessary for normal development of monocotyledonous plants as well as dicotyledonous plants.

  19. Serum concentration of Na, K, Ca, Mg, P, Zn and Cu in patients with essential arterial hypertension.

    PubMed

    Uza, G; Pavel, O; Kovacs, A; Uza, D; Vlaicu, R

    1984-01-01

    Serum concentration of Na, K, Ca, Mg and inorganic phosphate as well as serum levels of Zn and Cu were determined in control subjects and in patients with essential arterial hypertension (EAH) divided according to the stage of the disease. No significant differences were found between the serum mean levels of Na, K, Ca, Mg, Zn and Cu in controls and in patients with EAH. A significant decrease of the serum Zn was noted in the third stage of EAH. A number of cases with hypomagnesemia and/or hypopotassemia probably caused by a long term uncontrolled therapy was also detected. The concentration of inorganic phosphate was significantly lower in patients with EAH associated with overweight than in hypertensive patients with normal body weight and in controls. It is considered that a sustained study of the complex interrelationship between electrolyte interaction and the functional aspects of the arterial wall could still contribute to a better understanding of pathogenic aspects of EAH and of its complications including those subsequent to modern diuretic therapy.

  20. Overcoming Constraints of Building Successful Partnerships Incorporating STEM Research Into K-12 Classrooms

    NASA Astrophysics Data System (ADS)

    Radencic, S.; McNeal, K. S.; Pierce, D.; Hare, D.

    2011-12-01

    The Initiating New Science Partnerships in Rural Education (INSPIRE) program at Mississippi State University (MSU), funded by the NSF Graduate STEM Fellows in K-12 Education (GK12) program, focuses on the advancement of Earth and Space science education in K-12 classrooms. INSPIRE is currently in its second year of partnering ten graduate students from the STEM fields of Geosciences, Engineering and Chemistry at MSU with five teachers from local, rural school districts. The five year project serves to increase inquiry and technology experiences in science and math while enhancing graduate student's communication skills as they create interactive lessons linking their STEM research focus to the state and national standards covered in the classrooms. Each graduate student is responsible for the development of two lessons each month of the school year that are then published on the INSPIRE project webpage, www.gk12.msstate.edu, where they are a free resource for any K-12 classroom teacher seeking innovative activities for their classrooms. Many of the participating teachers and graduate students share activities developed with non-participating teachers, expanding INSPIRE's outreach throughout the local community. Numerous challenges were met during the formation of the program as well as throughout the first year in which the project management team worked together to find solutions ensuring that INSPIRE maintained successful partnerships for all involved. Proposed solutions of the following key components were identified by INSPIRE through the development, implementation, and continuous evaluation (internal and external) of the first year of the program as areas that can pose challenges to the construction of strong relationships between STEM research and K-12 classrooms: initializing the partnerships with the K-12 classrooms and STEM graduate fields at the university; maintaining strong partnerships; providing appropriate training and support; developing sound

  1. Crystal structure of κ-Ag2Mg5

    NASA Astrophysics Data System (ADS)

    Castro, Facundo J.; Primo, Gastón A.; Urretavizcaya, Guillermina

    2018-02-01

    The structure of κ-Ag2Mg5 has been refined based on X-ray powder diffraction measurements (Rwp = 0.083). The compound has been prepared by combining mechanical alloying techniques and thermal treatments. The intermetallic presents the prototypical structure of Co2Al5, an hexagonal crystal with the symmetries of space group P63/mmc, and belongs to the family of kappa-phase structure compounds. The unit cell dimensions are a=8.630(1) Å and c=8.914(1) Å. Five crystallographically independent sites are occupied, Wyckoff positions 12k, 6h and 2a are filled with Mg, another 6h site is occupied with Ag, and the 2c site presents mixed Ag/Mg occupancy. The crystal chemistry of the structure and bonding are briefly discussed in the paper.

  2. Comprehension Across the Curriculum: Perspectives and Practices K-12

    ERIC Educational Resources Information Center

    Ganske, Kathy, Ed.; Fisher, Douglas, Ed.

    2009-01-01

    Successful students use comprehension skills and strategies throughout the school day. In this timely book, leading scholars present innovative ways to support reading comprehension across content areas and the full K-12 grade range. Chapters provide specific, practical guidance for selecting rewarding texts and promoting engagement and…

  3. AIAA Educator Academy: Enriching STEM Education for K-12 Students

    NASA Astrophysics Data System (ADS)

    Slagle, E.; Bering, E. A.; Longmier, B. W.; Henriquez, E.; Milnes, T.; Wiedorn, P.; Bacon, L.

    2012-12-01

    Educator Academy is a K-12 STEM curriculum developed by the STEM K-12 Outreach Committee of the American Institute of Aeronautics and Astronautics (AIAA). Consisting of three independent curriculum modules, K-12 students participate in inquiry-based engineering challenges to improve critical thinking skills and enhance problem solving skills. The Mars Rover Celebration Curriculum Module is designed for students in grades 3-8. Throughout this module, students learn about Mars and the solar system. Working with given design criteria, students work in teams to do basic research about Mars that will determine the operational objectives and structural features of their rover. Then, students participate in the design and construction of a model of a mock-up Mars Rover to carry out a specific science mission on the surface of Mars. At the end of this project, students have the opportunity to participate in a regional capstone event where students share their rover designs and what they have learned. The Electric Cargo Plan Curriculum Module is designed for students in grades 6-12. Throughout this module, students learn about aerodynamics and the four forces of flight. Working individually or in teams, students design and construct an electrically-powered model aircraft to fly a tethered flight of at least one lap without cargo, followed by a second tethered flight of one lap carrying as much cargo as possible. At the end of this project, students have the opportunity to participate in a regional capstone event where students share what they have learned and compete with their different cargo plane designs. The Space Weather Balloon Curriculum Module is designed for students in grades 9-12. Throughout this module, students learn and refine physics concepts as well as experimental research skills. Students participate in project-based learning that is experimental in nature. Students are engaged with the world around them as they collaborate to launch a high altitude

  4. Zero Energy Schools: Designing for the Future: Zero Energy Ready K-12 Schools

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Torcellini, Paul A

    Designing, building, and operating zero energy ready K-12 schools provides benefits for districts, students, and teachers. Optimizing energy efficiency is important in any building, but it's particularly important in K-12 schools. Many U.S. school districts struggle for funding, and improving a school building's energy efficiency can free up operational funds that may then be available for educational and other purposes.

  5. High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-δ perovskites as prospective electrode materials for symmetrical SOFC

    NASA Astrophysics Data System (ADS)

    Istomin, S. Ya.; Morozov, A. V.; Abdullayev, M. M.; Batuk, M.; Hadermann, J.; Kazakov, S. M.; Sobolev, A. V.; Presniakov, I. A.; Antipov, E. V.

    2018-02-01

    La1-yCayFe0.5+x(Mg,Mo)0.5-xO3-δ oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mössbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-δ and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-δ) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-δ is oxygen deficient with δ ≈ 0.15. Oxides are stable in reducing atmosphere (Ar/H2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1-xGdxO2-x/2 electrolyte mixtures treated at 1173-1373K, while Fe-rich compositions (x≥0.1) react with Zr1-xYxO2-x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4-12.7 ppm K-1. In reducing atmosphere their TECs were found to increase up to 12.1-15.4 ppm K-1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell.

  6. The Oligo-Acyl Lysyl Antimicrobial Peptide C12K-2β12 Exhibits a Dual Mechanism of Action and Demonstrates Strong In Vivo Efficacy against Helicobacter pylori

    PubMed Central

    Makobongo, Morris O.; Gancz, Hanan; Carpenter, Beth M.; McDaniel, Dennis P.

    2012-01-01

    Helicobacter pylori has developed antimicrobial resistance to virtually all current antibiotics. Thus, there is a pressing need to develop new anti-H. pylori therapies. We recently described a novel oligo-acyl-lysyl (OAK) antimicrobial peptidomimetic, C12K-2β12, that shows potent in vitro bactericidal activity against H. pylori. Herein, we define the mechanism of action and evaluate the in vivo efficacy of C12K-2β12 against H. pylori after experimental infection of Mongolian gerbils. We demonstrate using a 1-N-phenylnaphthylamine (fluorescent probe) uptake assay and electron microscopy that C12K-2β12 rapidly permeabilizes the bacterial membrane and creates pores that cause bacterial cell lysis. Furthermore, using nucleic acid binding assays, Western blots, and confocal microscopy, we show that C12K-2β12 can cross the bacterial membranes into the cytoplasm and tightly bind to bacterial DNA, RNA, and proteins, a property that may result in inhibition of enzymatic activities and macromolecule synthesis. To define the in vivo efficacy of C12K-2β12, H. pylori-infected gerbils were orogastrically treated with increasing doses and concentrations of C12K-2β12 1 day or 1 week postinfection. The efficacy of C12K-2β12 was strongest in animals that received the largest number of doses at the highest concentration, indicating dose-dependent activity of the peptide (P < 0.001 by analysis of variance [ANOVA]) regardless of the timing of the treatment with C12K-2β12. Overall, our results demonstrate a dual mode of action of C12K-2β12 against the H. pylori membrane and cytoplasmic components. Moreover, and consistent with the previously reported in vitro efficacy, C12K-2β12 shows significant in vivo efficacy against H. pylori when used as monotherapy. Therefore, OAK peptides may be a valuable resource for therapeutic treatment of H. pylori infection. PMID:22064541

  7. A bronze matryoshka: the discrete intermetalloid cluster [Sn@Cu12@Sn20](12-) in the ternary phases A12Cu12Sn21 (A = Na, K).

    PubMed

    Stegmaier, Saskia; Fässler, Thomas F

    2011-12-14

    The synthesis and crystal structure of the first ternary A-Cu-Sn intermetallic phases for the heavier alkali metals A = Na to Cs is reported. The title compounds A(12)Cu(12)Sn(21) show discrete 33-atom intermetalloid Cu-Sn clusters {Sn@Cu(12)@Sn(20)}, which are composed of {Sn(20)} pentagonal dodecahedra surrounding {Cu(12)} icosahedra with single Sn atoms at the center. Na(12)Cu(12)Sn(21) and K(12)Cu(12)Sn(21) were characterized by single-crystal XRD studies, and the successful synthesis of analogous A-Cu-Sn compounds with A = Rb and Cs is deduced from powder XRD data. The isotypic A(12)Cu(12)Sn(21) phases crystallize in the cubic space group Pn ̅3m (No. 224), with the Cu-Sn clusters adopting a face centered cubic arrangement. A formal charge of 12- can be assigned to the {Sn@Cu(12)@Sn(20)} cluster unit, and the interpretation of the title compounds as salt-like intermetallic phases featuring discrete anionic intermetalloid [Sn@Cu(12)@Sn(20)](12-) clusters separated by alkali metal cations is supported by electronic structure calculations. For both Na(12)Cu(12)Sn(21) and K(12)Cu(12)Sn(21), DFT band structure calculations (TB-LMTO-ASA) reveal a band gap. The discrete [Sn@Cu(12)@Sn(20)](12-) cluster is analyzed in consideration of the molecular orbitals obtained from hybrid DFT calculations (Gaussian 09) for the cluster anion. The [Sn@Cu(12)@Sn(20)](12-) cluster MOs can be classified with labels indicating the numbers of radial and angular nodes, in the style of spherical shell models of cluster bonding. © 2011 American Chemical Society

  8. A Longitudinal Study of the Effectiveness of a K-12 Engagement Program on Graduate Student Learning Outcomes

    ERIC Educational Resources Information Center

    Weeks, Faith; Gong, Ruiyang; Harbor, Jon

    2015-01-01

    Programs that connect higher and K-12 education provide benefits to K-12 students, teachers, and higher education. The National Science Foundation (NSF) invested in programs connecting domestic STEM graduate students with K-12 education for over a decade (GK-12), intending that such engagement would help achieve graduate student learning outcomes…

  9. The molecular structure of the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 - A vibrational spectroscopic study

    NASA Astrophysics Data System (ADS)

    Frost, Ray L.; López, Andrés; Xi, Yunfei; Scholz, Ricardo; Souza, Larissa; Lana, Cristiano

    2014-07-01

    We have studied the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 using a combination of DEM with EDX and vibrational spectroscopic techniques. The mineral occurs as colorless, gray, yellow to white crystals in the triclinic crystal system. The studied sample is from the Antandrokomby Mine, Sahatany valley, Madagascar. The mineral is prized as a semi-precious jewel. Semi-quantitative chemical composition shows a Al, Ca, borate with minor amounts of K, Mg and Cs. The mineral has a characteristic borate Raman spectrum and bands are assigned to the stretching and bending modes of B, Be and Al. No Raman bands in the OH stretching region were observed.

  10. K-12 and University Partnerships: Bridging the Advocacy Gap

    ERIC Educational Resources Information Center

    Bryan, Charity; Sims, Sandra

    2011-01-01

    Research has cited numerous advantages and benefits of K-12 collaborations with the larger university community (Castle, Fox, & Souder, 2006; Crocco, Faithfull, & Schwartz, 2003). Departments of kinesiology across the country are well positioned to establish partnerships with local school systems in order to advocate for quality, daily physical…

  11. Best Practices in Administration of K-12 Dance Programs

    ERIC Educational Resources Information Center

    Henneman, Suzanne E.

    2013-01-01

    The role of administering K-12 dance education programs is both exciting and invigorating. Being part of the decision-making process, problem solving with teams of colleagues, establishing routines and initiatives, creating "something from nothing," and watching programs grow is appealing to dance teachers as creative and critical…

  12. Radiation-hydrodynamic simulations of thermally-driven disc winds in X-ray binaries: A direct comparison to GRO J1655-40

    NASA Astrophysics Data System (ADS)

    Higginbottom, Nick; Knigge, Christian; Long, Knox S.; Matthews, James H.; Sim, Stuart A.; Hewitt, Henrietta A.

    2018-06-01

    Essentially all low-mass X-ray binaries (LMXBs) in the soft state appear to drive powerful equatorial disc winds. A simple mechanism for driving such outflows involves X-ray heating of the top of the disc atmosphere to the Compton temperature. Beyond the Compton radius, the thermal speed exceeds the escape velocity, and mass loss is inevitable. Here, we present the first coupled radiation-hydrodynamic simulation of such thermally-driven disc winds. The main advance over previous modelling efforts is that the frequency-dependent attenuation of the irradiating SED is taken into account. We can therefore relax the approximation that the wind is optically thin throughout which is unlikely to hold in the crucial acceleration zone of the flow. The main remaining limitations of our simulations are connected to our treatment of optically thick regions. Adopting parameters representative of the wind-driving LMXB GRO J1655-40, our radiation-hydrodynamic model yields a mass-loss rate that is ≃ 5 × lower than that suggested by pure hydrodynamic, optically thin models. This outflow rate still represents more than twice the accretion rate and agrees well with the mass-loss rate inferred from Chandra/HETG observations of GRO J1655-40 at a time when the system had a similar luminosity to that adopted in our simulations. The Fe XXV and Fe XXVI Lyman {α } absorption line profiles observed in this state are slightly stronger than those predicted by our simulations but the qualitative agreement between observed and simulated outflow properties means that thermal driving is a viable mechanism for powering the disc winds seen in soft-state LMXBs.

  13. Nitrogen conservation in simulated food waste aerobic composting process with different Mg and P salt mixtures.

    PubMed

    Li, Yu; Su, Bensheng; Liu, Jianlin; Du, Xianyuan; Huang, Guohe

    2011-07-01

    To assess the effects of three types of Mg and P salt mixtures (potassium phosphate [K3PO4]/magnesium sulfate [MgSO4], potassium dihydrogen phosphate [K2HPO4]/MgSO4, KH2PO4/MgSO4) on the conservation of N and the biodegradation of organic materials in an aerobic food waste composting process, batch experiments were undertaken in four reactors (each with an effective volume of 30 L). The synthetic food waste was composted of potatoes, rice, carrots, leaves, meat, soybeans, and seed soil, and the ratio of C and N was 17:1. Runs R1-R3 were conducted with the addition of K3PO4/ MgSO4, K2HPO4/MgSO4, and KH2PO4/MgSO4 mixtures, respectively; run R0 was a blank performed without the addition of Mg and P salts. After composting for 25 days, the degrees of degradation of the organic materials in runs R0-R3 were 53.87, 62.58, 59.14, and 49.13%, respectively. X-ray diffraction indicated that struvite crystals were formed in runs R1-R3 but not in run R0; the gaseous ammonia nitrogen (NH3-N) losses in runs R0-R3 were 21.2, 32.8, 12.6, and 3.5% of the initial total N, respectively. Of the tested Mg/P salt mixtures, the K2HPO4/ MgSO4 system provided the best combination of conservation of N and biodegradation of organic materials in this food waste composting process.

  14. Intensive lowering of LDL cholesterol with 80 mg versus 20 mg simvastatin daily in 12,064 survivors of myocardial infarction: a double-blind randomised trial.

    PubMed

    Armitage, Jane; Bowman, Louise; Wallendszus, Karl; Bulbulia, Richard; Rahimi, Kazem; Haynes, Richard; Parish, Sarah; Peto, Richard; Collins, Rory

    2010-11-13

    Lowering of LDL cholesterol reduces major vascular events, but whether more intensive therapy safely produces extra benefits is uncertain. We aimed to establish efficacy and safety of more intensive statin treatment in patients at high cardiovascular risk. We undertook a double-blind randomised trial in 12,064 men and women aged 18-80 years with a history of myocardial infarction. Participants were either currently on or had clear indication for statin therapy, and had a total cholesterol concentration of at least 3·5 mmol/L if already on a statin or 4·5 mmol/L if not. Randomisation to either 80 mg or 20 mg simvastatin daily was done centrally using a minimisation algorithm. Participants were assessed at 2, 4, 8, and 12 months after randomisation and then every 6 months until final follow-up. The primary endpoint was major vascular events, defined as coronary death, myocardial infarction, stroke, or arterial revascularisation. Analysis was by intention to treat. This study is registered, number ISRCTN74348595. 6031 participants were allocated 80 mg simvastatin daily, and 6033 allocated 20 mg simvastatin daily. During a mean follow-up of 6·7 (SD 1·5) years, allocation to 80 mg simvastatin produced an average 0·35 (SE 0·01) mmol/L greater reduction in LDL cholesterol compared with allocation to 20 mg. Major vascular events occurred in 1477 (24·5%) participants allocated 80 mg simvastatin versus 1553 (25·7%) of those allocated 20 mg, corresponding to a 6% proportional reduction (risk ratio 0·94, 95% CI 0·88-1·01; p=0·10). There were no apparent differences in numbers of haemorrhagic strokes (24 [0·4%] vs 25 [0·4%]) or deaths attributed to vascular (565 [9·4%] vs 572 [9·5%]) or non-vascular (399 [6·6%] vs 398 [6·6%]) causes. Compared with two (0·03%) cases of myopathy in patients taking 20 mg simvastatin daily, there were 53 (0·9%) cases in the 80 mg group. The 6% (SE 3·5%) reduction in major vascular events with a further 0·35 mmol/L reduction in

  15. A randomized, double-blind, active-controlled phase 2 trial to evaluate a novel selective and reversible intravenous and oral P2Y12 inhibitor elinogrel versus clopidogrel in patients undergoing nonurgent percutaneous coronary intervention: the INNOVATE-PCI trial.

    PubMed

    Welsh, Robert C; Rao, Sunil V; Zeymer, Uwe; Thompson, Vivian P; Huber, Kurt; Kochman, Janusz; McClure, Matthew W; Gretler, Daniel D; Bhatt, Deepak L; Gibson, C Michael; Angiolillo, Dominick J; Gurbel, Paul A; Berdan, Lisa G; Paynter, Gayle; Leonardi, Sergio; Madan, Mina; French, William J; Harrington, Robert A

    2012-06-01

    We evaluated the safety, efficacy, and tolerability of elinogrel, a competitive, reversible intravenous and oral P2Y(12) inhibitor that does not require metabolic activation, in patients undergoing nonurgent percutaneous coronary intervention. In a randomized, double-blind, dose-ranging phase 2b trial, 652 patients received either 300 or 600 mg of clopidogrel pre-percutaneous coronary intervention followed by 75 mg daily or 80 or 120 mg of IV elinogrel followed by 50, 100, or 150 mg oral elinogrel twice daily. Numerous exploratory safety and efficacy end points were assessed and, as such, had no prespecified primary end point, and the study was not powered to conclusively evaluate its objectives. Thrombolysis in myocardial infarction combined bleeding was increased with elinogrel (hazard ratio, 1.98; 95% confidence interval, 1.10 to 3.57), related largely to increased bleeding requiring medical attention (elinogrel 47/408 [11.5%] versus clopidogrel 13/208 [6.3%]) and occurring primarily at the percutaneous coronary intervention access site. Efficacy end points and postprocedure cardiac enzyme were similar, but there was a nonsignificant higher frequency of periprocedural myocardial infarctions in the elinogrel arms (OR, 1.59; 95% confidence interval, 0.79 to 3.48). There was an increased incidence of dyspnea (elinogrel 50/408 [12.3%] versus clopidogrel 8/208 [3.8%]) and transaminase elevation (alanine transferase/aspartate transferase >3× the upper limit of normal; elinogrel 18/408 [4.4%] versus clopidogrel 2/208 [1.0%]) in the elinogrel arms, but there were no cases of heart block, bradycardia, hypotension, or liver failure. In patients undergoing nonurgent percutaneous coronary intervention and in comparison with clopidogrel, intravenous and oral elinogrel therapy did not significantly increase thrombolysis in myocardial infarction major or minor bleeding, although bleeding requiring medical attention was more common. The significance of these findings will need

  16. Music and ambient operating room noise in patients undergoing spinal anesthesia.

    PubMed

    Ayoub, Chakib M; Rizk, Laudi B; Yaacoub, Chadi I; Gaal, Dorothy; Kain, Zeev N

    2005-05-01

    Previous studies have indicated that music decreases intraoperative sedative requirements in patients undergoing surgical procedures under regional anesthesia. In this study we sought to determine whether this decrease in sedative requirements results from music or from eliminating operating room (OR) noise. A secondary aim of the study was to examine the relationship of response to intraoperative music and participants' culture (i.e., American versus Lebanese). Eighty adults (36 American and 54 Lebanese) undergoing urological procedures with spinal anesthesia and patient-controlled IV propofol sedation were randomly assigned to intraoperative music, white noise, or OR noise. We found that, controlling for ambient OR noise, intraoperative music decreases propofol requirements (0.004 +/- 0.002 mg . kg(-1) . min(-1) versus 0.014 +/- 0.004 mg . kg(-1) . min(-1) versus 0.012 +/- 0.002 mg . kg(-1) . min(-1); P = 0.026). We also found that, regardless of group assignment, Lebanese patients used less propofol as compared with American patients (0.005 +/- 0.001 mg . kg(-1) . min(-1) versus 0.017 +/- 0.003 mg . kg(-1) . min(-1); P = 0.001) and that, in both sites, patients in the music group required less propofol (P < 0.05). We conclude that when controlling for ambient OR noise, intraoperative music decreases propofol requirements of both Lebanese and American patients who undergo urological surgery under spinal anesthesia.

  17. Finished Genome Sequence of Escherichia coli K-12 Strain HMS174 (ATCC 47011).

    PubMed

    Mairhofer, Juergen; Krempl, Peter M; Thallinger, Gerhard G; Striedner, Gerald

    2014-11-20

    Escherichia coli strain K-12 substrain HMS174 is an engineered descendant of the E. coli K-12 wild-type strain. Like its ancestor, it is an important organism in biotechnological research and is used in fermentation processes for heterologous protein production. Here, we report the complete genome sequence of E. coli HMS174 (ATCC 47011). Copyright © 2014 Mairhofer et al.

  18. Spacemakers: A Leadership Perspective on Curriculum and the Purpose of K-12 Educational Makerspaces

    ERIC Educational Resources Information Center

    Harron, Jason R.; Hughes, Joan E.

    2018-01-01

    This qualitative research study investigated how educational makerspace leaders, whom we refer to as spacemakers, framed the purpose of the makerspace in K-12 education and how makerspaces support school curriculum. Using interviews with twelve K-12 spacemakers, the study found spacemakers were experienced, self-motivated educators. These leaders…

  19. Virtual K-12 Learning: New Learning Frontiers for State Education Agencies

    ERIC Educational Resources Information Center

    Natale, Catherine Fisk; Cook, Janet

    2012-01-01

    This article explores the role of state education agencies in three states that have embarked on ambitious kindergarten through Grade 12 (K-12) virtual learning initiatives: Alabama, Florida, and Idaho. Subject to a rapidly changing environment influenced by factors beyond the jurisdiction of many state departments of education, the world of…

  20. Reduction in postoperative high-density lipoprotein cholesterol levels in children undergoing the Fontan operation.

    PubMed

    Zyblewski, Sinai C; Argraves, W Scott; Graham, Eric M; Slate, Elizabeth H; Atz, Andrew M; Bradley, Scott M; McQuinn, Tim C; Wilkerson, Brent A; Wing, Shane B; Argraves, Kelley M

    2012-10-01

    Despite the emerging relevance of high-density lipoprotein (HDL) in the inflammatory cascade and vascular barrier integrity, HDL levels in children undergoing cardiac surgery are unexplored. As a measure of HDL levels, the HDL-cholesterol (HDL-C) in single-ventricle patients was quantified before and after the Fontan operation, and it was determined whether relationships existed between the duration and the type of postoperative pleural effusions. The study prospectively enrolled 12 children undergoing the Fontan operation. Plasma HDL-C levels were measured before and after cardiopulmonary bypass. The outcome variables of interest were the duration and type of chest tube drainage (chylous vs. nonchylous). The Kendall rank correlation coefficient and the Wilcoxon rank sum test were used. There were 11 complete observations. The median preoperative HDL-C level for all the subjects was 30 mg/dl (range, 24-53 mg/dl), and the median postcardiopulmonary bypass level was 21 mg/dl (range, 14-46 mg/dl) (p = 0.004). There was a tendency toward a moderate inverse correlation (-0.42) between the postcardiopulmonary bypass HDL-C level and the duration of chest tube drainage, but the result was not statistically significant (p = 0.07). In the chylous effusion group, the median postcardiopulmonary bypass HDL-C tended to be lower (16 vs. 23 mg/dl; p = 0.09). After the Fontan operation, the plasma HDL-C levels in children are significantly reduced. It is reasonable to conclude that the reduction in HDL-C reflects reduced plasma levels of HDL particles, which may have pertinent implications in postoperative pleural effusions given the antiinflammatory and endothelial barrier functions of HDL.

  1. A SUPER-EDDINGTON, COMPTON-THICK WIND IN GRO J1655–40?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Neilsen, J.; Homan, J.; Rahoui, F.

    2016-05-01

    During its 2005 outburst, GRO J1655–40 was observed at high spectral resolution with the Chandra High-Energy Transmission Grating Spectrometer, revealing a spectrum rich with blueshifted absorption lines indicative of an accretion disk wind—apparently too hot, too dense, and too close to the black hole to be driven by radiation pressure or thermal pressure (Miller et al.). However, this exotic wind represents just one piece of the puzzle in this outburst, as its presence coincides with an extremely soft and curved X-ray continuum spectrum, remarkable X-ray variability (Uttley and Klein-Wolt), and a bright, unexpected optical/infrared blackbody component that varies on themore » orbital period. Focusing on the X-ray continuum and the optical/infrared/UV spectral energy distribution, we argue that the unusual features of this “hypersoft state” are natural consequences of a super-Eddington Compton-thick wind from the disk: the optical/infrared blackbody represents the cool photosphere of a dense, extended outflow, while the X-ray emission is explained as Compton scattering by the relatively cool, optically thick wind. This wind obscures the intrinsic luminosity of the inner disk, which we suggest may have been at or above the Eddington limit.« less

  2. Evaluation of synergistic antimicrobial effect of vitamins (A, B1, B2, B6, B12, C, D, E and K) with antibiotics against resistant bacterial strains.

    PubMed

    Shahzad, Shakeel; Ashraf, M Adnan; Sajid, M; Shahzad, Aqeel; Rafique, Azhar; Mahmood, M Shahid

    2018-02-02

    Multiple drug resistant super bugs of Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) are becoming challenge for healthcare professionals. In this study, vitamins were evaluated for synergistic activity with the antibiotics. Synergistic effect between antibiotic and stock solutions of vitamins is evaluated by using Kirby-Bauer disc diffusion assay. Distilled water and propylene glycol were used as solvent for water soluble vitamins and fat-soluble vitamins respectively. The final concentration of 10mg/ml of each water-soluble vitamin B1 (Thiamine), B2 (Riboflavin), B6 (Pyridoxine) B12 (Methylcobalamin), C (Ascorbic acid) and 0.1mg/ml of each fat soluble vitamin A (retinol), D (cholecalciferol) E (αTocopherol) K (Menadione) were used with the antibiotics. The results depicted that vitamin K and E have better synergistic activity with piperacillin-tazobactam, imipenem and doripenem antibiotics against A. baumannii. While vitamin B1, B2 and B12 showed remarkable synergistic activity with linezolid against MRSA. Vitamin B1 was further tested to have better synergism with antibiotics oxacillin, tetracycline, rifampicin and linezolid against MRSA. The fat-soluble vitamins E and K were good in synergism against Gram negative A. baumannii while water soluble vitamins as B1, B2 and B12 were effective against MRSA but not against A. baumannii. This synergistic action of vitamins with the antibiotics can be used as a tool to treat multiple drug resistant super bugs with further evaluation at molecular level. Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  3. Structure of Escherichia coli AdhP (ethanol-inducible dehydrogenase) with bound NAD.

    PubMed

    Thomas, Leonard M; Harper, Angelica R; Miner, Whitney A; Ajufo, Helen O; Branscum, Katie M; Kao, Lydia; Sims, Paul A

    2013-07-01

    The crystal structure of AdhP, a recombinantly expressed alcohol dehydrogenase from Escherichia coli K-12 (substrain MG1655), was determined to 2.01 Å resolution. The structure, which was solved using molecular replacement, also included the structural and catalytic zinc ions and the cofactor nicotinamide adenine dinucleotide (NAD). The crystals belonged to space group P21, with unit-cell parameters a = 68.18, b = 118.92, c = 97.87 Å, β = 106.41°. The final R factor and Rfree were 0.138 and 0.184, respectively. The structure of the active site of AdhP suggested a number of residues that may participate in a proton relay, and the overall structure of AdhP, including the coordination to structural and active-site zinc ions, is similar to those of other tetrameric alcohol dehydrogenase enzymes.

  4. Trend Analysis of Indiana K-12 Library Services Since the School Library Printed Materials Grant

    ERIC Educational Resources Information Center

    Plucker, Jonathan; Humphrey, Jack; Simmons, Ada; Ravert, Russell; Kohler, Kristin; Hansen, John

    2004-01-01

    The Indiana General Assembly recognized the importance of updating school library book collections by appropriating $4 million for K-8 schools during the 1997-1999 school years, $6 million for K-12 schools during the 1999-2001 school years, and $6 million for K-12 schools for the 2001-2003 school years. However, due to state budgetary restraints,…

  5. The K-12 Educational Technology Value Chain: Apps for Kids, Tools for Teachers and Levers for Reform

    ERIC Educational Resources Information Center

    Pierce, Glenn L.; Cleary, Paul F.

    2016-01-01

    Historically implementing, maintaining and managing educational technology has been difficult for K-12 educational systems. Consequently, opportunities for significant advances in K-12 education have often gone unrealized. With the maturation of Internet delivered services along with K-12 institutional trends, educational technologies are poised…

  6. K-12 Urban Career Education Infusion Project. Final Evaluation

    ERIC Educational Resources Information Center

    Denton, William T.; Kleck, Wil

    The K-12 Urban Career Education Infusion Project of the Dallas (Texas) Independent School District focused on fourteen schools located in the East Oak Cliff Subdistrict, a predominantly (98%) black community. Conducted in two phases, the project attempted to demonstrate that through infusing career education into the existing curriculum, trained…

  7. Environmental Education: Food - The Coming Crisis (Grades K-12).

    ERIC Educational Resources Information Center

    New Jersey State Council for Environmental Education, Upper Montclair.

    This publication presents classroom activities for teaching about the world food shortage. These activities are organized by objectives, are multidisciplinary and cover the K-12 grade levels. The objectives listed include: (1) Describe some food chains; (2) Appraise the effect of soil conditions, geographic and climatic factors on the food…

  8. Teaching Engineering at the K-12 Level: Two Perspectives

    ERIC Educational Resources Information Center

    Smith, Kenneth L.; Burghardt, David

    2007-01-01

    In this article, the authors share their own perspectives regarding engineering education at the K-12 level. Smith believes that there must be a more direct infusion of appropriate mathematics and science with the unique technological content (tools, machines, materials, processes) for an effective engineering education program to exist. He thinks…

  9. Unified Science Approach K-12, Proficiency Levels 1-6.

    ERIC Educational Resources Information Center

    Oickle, Eileen M., Ed.

    Presented are first-revision materials of the K-12 unified science program implemented in the public schools of Anne Arundel County, Maryland. Detailed descriptions are given of the roles of students and teachers, purposes of bibliography, major concepts in unified science, processes of inquiry, scheme and model for scientific literacy, and…

  10. Applying the Quadratic Usage Framework to Research on K-12 STEM Digital Learning Resources

    ERIC Educational Resources Information Center

    Luetkemeyer, Jennifer R.

    2016-01-01

    Numerous policymakers have called for K-12 educators to increase their effectiveness by transforming science, technology, engineering, and mathematics (STEM) learning and teaching with digital resources and tools. In this study we outline the significance of studying pressing issues related to use of digital resources in the K-12 environment and…

  11. Problems Associated with a Lack of Cohesive Policy in K-12 Pre-College Engineering

    ERIC Educational Resources Information Center

    Chandler, John; Fontenot, A. Dean; Tate, Derrick

    2011-01-01

    This article identifies a number of issues associated with current STEM education reform efforts, especially with regard to efforts to integrate engineering education into the K-12 curriculum. Precollege engineering is especially problematic in STEM reform since there is no well-established tradition of engineering in the K-12 curriculum. This…

  12. Measuring the Level of Security in the K-12 IT Environment in Southern California

    ERIC Educational Resources Information Center

    Brown, Brandon R.

    2016-01-01

    Kindergartens through twelfth grade institutions (K-12) are susceptible to unauthorized breaches to the security of their networked systems. These systems house sensitive information for students and staff alike. K-12 organizations face a significant risk for loss of this information that can damage reputation and pose liability. Perpetrators have…

  13. Observations of the 12.3 micron Mg I emission line during a major solar flare

    NASA Technical Reports Server (NTRS)

    Deming, Drake; Jennings, Donald E.; Osherovich, Vladimir; Wiedemann, Gunter; Hewagama, Tilak

    1990-01-01

    The extremely Zeeman-sensitive 12.32 micron Mg I solar emission line was observed during a 3B/X5.7 solar flare on October 24, 1989. When compared to postflare values, Mg I emission-line intensity in the penumbral flare ribbon was 20 percent greater at the peak of the flare in soft X-rays, and the 12 micron continuum intensity was 7 percent greater. The flare also excited the emission line in the umbra where it is normally absent. The umbral flare emission exhibits a Zeeman splitting 200 G less than the adjacent penumbra, suggesting that it is excited at higher altitude. The absolute penumbral magnetic field strength did not change by more than 100 G between the flare peak and postflare period. However, a change in the inclination of the field lines, probably related to the formation and development of the flare loop system, was seen.

  14. Temperature-independent ferroelectric property and characterization of high-TC 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Linxing; Chen, Jun; Zhao, Hanqing; Fan, Longlong; Rong, Yangchun; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

    2013-08-01

    Ferroelectric property stability against elevated temperature is significant for ferroelectric film applications, such as non-volatile ferroelectric random access memories. The high-TC 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films show the temperature-independent ferroelectric properties, which were fabricated on Pt(111)/Ti/SiO2/Si substrates via sol-gel method. The present thin films were well crystallized in a phase-pure perovskite structure with a high (100) orientation and uniform texture. A remanent polarization (2Pr) of 77 μC cm-2 and a local effective piezoelectric coefficient d33* of 60 pm/V were observed in the 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films. It is interesting to observe a behavior of temperature-independent ferroelectric property in the temperature range of room temperature to 125 °C. The remanent polarization, coercive field, and polarization at the maximum field are almost constant in the investigated temperature range. Furthermore, the dielectric loss and fatigue properties of 0.2Bi(Mg1/2Ti1/2)O3-0.8PbTiO3 thin films have been effectively improved by the Mn-doping.

  15. Technological Collaborations: K-12 and Higher Education. Fastback 438.

    ERIC Educational Resources Information Center

    Ferguson, Kay McPherson; Kopp, O. W.

    This brief report examines various ways in which K-12 schools and institutions of higher education can collaborate to effect critical changes in teaching and learning through the use of computers. The first section briefly reviews the history of computer use in education, noting such critical needs as teacher training, and reviews the…

  16. Teachers' Curriculum Guide to the Hayward Shoreline, K-12.

    ERIC Educational Resources Information Center

    Bachle, Leo; And Others

    This teaching guide gives environmental education ideas for grades K-12. The field trips and activities all relate to the Hayward shoreline of the San Francisco, California, Bay. Included in the guide are 44 science activities, 15 social science activities, and 18 humanities activities. Each activity description gives the experience level, site…

  17. Tablets in K-12 Education: Integrated Experiences and Implications

    ERIC Educational Resources Information Center

    An, Heejung, Ed.; Alon, Sandra, Ed.; Fuentes, David, Ed.

    2015-01-01

    The inclusion of new and emerging technologies in the education sector has been a topic of interest to researchers, educators, and software developers alike in recent years. Utilizing the proper tools in a classroom setting is a critical factor in student success. "Tablets in K-12 Education: Integrated Experiences and Implications"…

  18. Project WILD Aquatic K-12 Curriculum and Activity Guide

    ERIC Educational Resources Information Center

    Council for Environmental Education, 2011

    2011-01-01

    The "Project WILD Aquatic K-12 Curriculum and Activity Guide" emphasizes aquatic wildlife and aquatic ecosystems. It is organized in topic units and is based on the Project WILD conceptual framework. Because these activities are designed for integration into existing courses of study, instructors may use one or many Project WILD Aquatic activities…

  19. Unifying K-12 Learning Processes: Integrating Curricula through Learning

    ERIC Educational Resources Information Center

    Bosse, Michael J.; Fogarty, Elizabeth A.

    2011-01-01

    This study was designed to examine whether a set of cross-curricular learning processes could be found in the respective K-12 US national standards for math, language arts, foreign language, science, social studies, fine arts, and technology. Using a qualitative research methodology, the standards from the national associations for these content…

  20. Reprogramming of Escherichia coli K-12 Metabolism during the Initial Phase of Transition from an Anaerobic to a Micro-Aerobic Environment

    PubMed Central

    Trotter, Eleanor W.; Rolfe, Matthew D.; Hounslow, Andrea M.; Craven, C. Jeremy; Williamson, Michael P.; Sanguinetti, Guido; Poole, Robert K.; Green, Jeffrey

    2011-01-01

    Background Many bacteria undergo transitions between environments with differing O2 availabilities as part of their natural lifestyles and during biotechnological processes. However, the dynamics of adaptation when bacteria experience changes in O2 availability are understudied. The model bacterium and facultative anaerobe Escherichia coli K-12 provides an ideal system for exploring this process. Methods and Findings Time-resolved transcript profiles of E. coli K-12 during the initial phase of transition from anaerobic to micro-aerobic conditions revealed a reprogramming of gene expression consistent with a switch from fermentative to respiratory metabolism. The changes in transcript abundance were matched by changes in the abundances of selected central metabolic proteins. A probabilistic state space model was used to infer the activities of two key regulators, FNR (O2 sensing) and PdhR (pyruvate sensing). The model implied that both regulators were rapidly inactivated during the transition from an anaerobic to a micro-aerobic environment. Analysis of the external metabolome and protein levels suggested that the cultures transit through different physiological states during the process of adaptation, characterized by the rapid inactivation of pyruvate formate-lyase (PFL), a slower induction of pyruvate dehydrogenase complex (PDHC) activity and transient excretion of pyruvate, consistent with the predicted inactivation of PdhR and FNR. Conclusion Perturbation of anaerobic steady-state cultures by introduction of a limited supply of O2 combined with time-resolved transcript, protein and metabolite profiling, and probabilistic modeling has revealed that pyruvate (sensed by PdhR) is a key metabolic signal in coordinating the reprogramming of E. coli K-12 gene expression by working alongside the O2 sensor FNR during transition from anaerobic to micro-aerobic conditions. PMID:21980479

  1. Bronchopulmonary pharmacokinetic and pharmacodynamic profiles of levofloxacin 750 mg once daily in adults undergoing treatment for acute exacerbation of chronic bronchitis.

    PubMed

    Nicolau, David P; Sutherland, Christina; Winget, Donna; Baughman, Robert P

    2012-02-01

    While previous reports have described the bronchopulmonary profile of the fluoroquinolones in healthy volunteers, limited data are available in infected patients. The purpose of this study was to determine the intrapulmonary profile of high-dose (750 mg) levofloxacin in patients during an acute exacerbation of chronic bronchitis (AECB). Twenty-four patients experiencing clinical signs and symptoms of AECB were enrolled. Once enrolled, patients received levofloxacin 750 mg once daily × 5 days. Bronchoalveolar lavage aspirates and simultaneous plasma samples were obtained at 4 h, 12 h or 24 h after the third dose. Concentrations in biologic matrixes were determined with a validated HPLC method. Epithelial lining fluid (ELF) concentrations were calculated using the urea dilution method. Five patients did not complete the trial, 19 patients underwent bronchoscopy, 18 (52 ± 13 yrs) had sufficient samples for analysis and confirmed medication compliance. Mean plasma concentrations at 4, 12, and 24 h were 8.0 ± 2.5, 5.8 ± 1.2, and 2.2 ± 1.2 μg/mL. Mean ELF values at 4, 12, and 24 h were 7.5 ± 3.0, 8.3 ± 6.0, and 1.2 ± 0.9 μg/mL. Mean alveolar macrophage (AM) concentrations at 4, 12, and 24 h were 38.5 ± 43.7, 13.4 ± 14.4, and 9.0 ± 7.5 μg/mL. The penetration (ELF/plasma ratio) into the infection site was 113%. In these subjects with AECB, levofloxacin 750 mg once daily reached adequate exposures in the plasma, ELF, and AMs for the most commonly associated pathogens. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. K-12 Online Learning and Students with Disabilities: Perspectives from State Special Education Directors

    ERIC Educational Resources Information Center

    Burdette, Paula J.; Greer, Diana L.; Woods, Kari L.

    2013-01-01

    K-12 special education policies and practices that ensure students with disabilities receive a free, appropriate public education in the least restrictive environment are coming under pressure from the rapid expansion of online learning. Forty-six state and non-state jurisdiction special education directors responded to a brief survey about K-12…

  3. Loss of protein phosphatase 6 in mouse keratinocytes enhances K-rasG12D -driven tumor promotion.

    PubMed

    Kurosawa, Koreyuki; Inoue, Yui; Kakugawa, Yoichiro; Yamashita, Yoji; Kanazawa, Kosuke; Kishimoto, Kazuhiro; Nomura, Miyuki; Momoi, Yuki; Sato, Ikuro; Chiba, Natsuko; Suzuki, Mai; Ogoh, Honami; Yamada, Hidekazu; Miura, Koh; Watanabe, Toshio; Tanuma, Nobuhiro; Tachi, Masahiro; Shima, Hiroshi

    2018-05-14

    Here, we address the function of protein phosphatase 6 (PP6) loss on K-ras-initiated tumorigenesis in keratinocytes. To do so, we developed tamoxifen-inducible double mutant (K-ras G12D -expressing and Ppp6c-deficient) mice in which K-ras G12D expression is driven by the cytokeratin 14 (K14) promoter. Doubly-mutant mice showed early onset tumor formation in lip, nipples, external genitalia, anus and palms, and had to be sacrificed by three weeks after induction by tamoxifen, while comparably-treated K-ras G12D -expressing mice did not. HE-staining of lip tumors before euthanasia revealed that all were papillomas, some containing focal squamous cell carcinoma. Immunohistochemical analysis of lip of doubly-mutant versus K-ras G12D mice revealed that cell proliferation and cell size increased approximately two-fold relative to K-ras G12D -expressing mutants, and epidermal thickness of lip tissue greatly increased relative to that seen in K-ras G12D only mice. Moreover, AKT phosphorylation increased in K-ras G12D -expressing/Ppp6c-deficient cells, as did phosphorylation of the downstream effectors 4EBP1, S6, and GSK3, suggesting that protein synthesis and survival signals are enhanced in lip tissues of doubly-mutant mice. Finally, increased numbers of K14-positive cells were present in the suprabasal layer of doubly-mutant mice, indicating abnormal keratinocyte differentiation, and γH2AX-positive cells accumulated, indicating perturbed DNA repair. Taken together, Ppp6c deficiency enhances K-ras G12D -dependent tumor promotion. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. Disorder effects in Mn(12)-acetate at 83 K.

    PubMed

    Cornia, Andrea; Fabretti, Antonio Costantino; Sessoli, Roberta; Sorace, Lorenzo; Gatteschi, Dante; Barra, Anne-Laure; Daiguebonne, Carole; Roisnel, Thierry

    2002-07-01

    The structure of hexadeca-mu-acetato-tetraaquadodeca-mu(3)-oxo-dodecamanganese bis(acetic acid) tetrahydrate, [Mn(12)O(12)(CH(3)COO)(16)(H(2)O)(4)] x 2CH(3)COOH x 4H(2)O, known as Mn(12)-acetate, has been determined at 83 (2) K by X-ray diffraction methods. The fourfold (S(4)) molecular symmetry is disrupted by a strong hydrogen-bonding interaction with the disordered acetic acid molecule of solvation, which displaces one of the acetate ligands in the cluster. Up to six Mn(12) isomers are potentially present in the crystal lattice, which differ in the number and arrangement of hydrogen-bonded acetic acid molecules. These results considerably improve the structural information available on this molecular nanomagnet, which was first synthesized and characterized by Lis [Acta Cryst. (1980), B36, 2042-2046].

  5. Escherichia coli EDL933 Requires Gluconeogenic Nutrients To Successfully Colonize the Intestines of Streptomycin-Treated Mice Precolonized with E. coli Nissle 1917

    PubMed Central

    Schinner, Silvia A. C.; Mokszycki, Matthew E.; Adediran, Jimmy; Leatham-Jensen, Mary; Conway, Tyrrell

    2015-01-01

    Escherichia coli MG1655, a K-12 strain, uses glycolytic nutrients exclusively to colonize the intestines of streptomycin-treated mice when it is the only E. coli strain present or when it is confronted with E. coli EDL933, an O157:H7 strain. In contrast, E. coli EDL933 uses glycolytic nutrients exclusively when it is the only E. coli strain in the intestine but switches in part to gluconeogenic nutrients when it colonizes mice precolonized with E. coli MG1655 (R. L. Miranda et al., Infect Immun 72:1666–1676, 2004, http://dx.doi.org/10.1128/IAI.72.3.1666-1676.2004). Recently, J. W. Njoroge et al. (mBio 3:e00280-12, 2012, http://dx.doi.org/10.1128/mBio.00280-12) reported that E. coli 86-24, an O157:H7 strain, activates the expression of virulence genes under gluconeogenic conditions, suggesting that colonization of the intestine with a probiotic E. coli strain that outcompetes O157:H7 strains for gluconeogenic nutrients could render them nonpathogenic. Here we report that E. coli Nissle 1917, a probiotic strain, uses both glycolytic and gluconeogenic nutrients to colonize the mouse intestine between 1 and 5 days postfeeding, appears to stop using gluconeogenic nutrients thereafter in a large, long-term colonization niche, but continues to use them in a smaller niche to compete with invading E. coli EDL933. Evidence is also presented suggesting that invading E. coli EDL933 uses both glycolytic and gluconeogenic nutrients and needs the ability to perform gluconeogenesis in order to colonize mice precolonized with E. coli Nissle 1917. The data presented here therefore rule out the possibility that E. coli Nissle 1917 can starve the O157:H7 E. coli strain EDL933 of gluconeogenic nutrients, even though E. coli Nissle 1917 uses such nutrients to compete with E. coli EDL933 in the mouse intestine. PMID:25733524

  6. Unravelling regolith material types using Mg/Al and K/Al plot to support field regolith identification in the savannah regions of NW Ghana, West Africa

    NASA Astrophysics Data System (ADS)

    Arhin, Emmanuel; Zango, Saeed M.

    2015-12-01

    The XRF analytical method was used to measure the weight % of the major oxides in regolith samples. The metal weight % of Mg, K and Al were calculated from their oxides and were normalised relative to immobile Al calculated from its oxide. The plot of Mg/Al and K/Al identified the regolith of the study area to consist of 137 transported clays, 4 ferruginous sediments or ferricrete, 2 lateritic duricrust and 4 saprolites. Surface regolith that had undergone secondary transformation and shows compositional overlaps were 4 transported clays with Fe-oxide impregnation may be referred to as nodular laterite and 5 ferruginous saprolites. The variable regolith materials features identified from the 154 samples enabled the characterisation and identification of the different sample materials because an overprint of bedrock geochemistry is reflected in the regolith. Plot of Mg/Al and K/Al highlighted the compositional variability of the regolith samples and refute the notion of the homogeneity of all the sampled materials in the area. The study thus recognized Mg/Al versus K/Al plots to be used in supporting field identification of regolith mapping units particularly in complex regolith terrains of savannah regions of Ghana and in similar areas where geochemical exploration surveys are being carried out under cover.

  7. Interactive Teaching as a Recruitment and Training Tool for K-12 Science Teachers

    NASA Astrophysics Data System (ADS)

    Rosenberg, J. L.

    2004-12-01

    The Science, Technology, Engineering, and Mathematics Teacher Preparation (STEMTP) program at the University of Colorado has been designed to recruit and train prospective K-12 science teachers while improving student learning through interactive teaching. The program has four key goals: (1) recruit undergraduate students into K-12 science education, (2) provide these prospective teachers with hands-on experience in an interactive teaching pedagogy, (3) create an intergrated program designed to support (educationally, socially, and financially) and engage these prospective science teachers up until they obtain liscensure and/or their masters degree in education, and (4) improve student learning in large introductory science classes. Currently there are 31 students involved in the program and a total of 72 students have been involved in the year and a half it has been in existence. I will discuss the design of the STEMTP program, the success in recruiting K-12 science teachers, and the affect on student learning in a large lecture class of implementing interactive learning pedagogies by involving these prospective K-12 science teachers. J. L. Rosenberg would like to acknowledge the NSF Astronomy and Astrophysics Fellowship for support for this work. The course transformation project is also supported by grants from the National Science Foundation.

  8. Physical Education Teacher Educator's Perceptions toward and Understanding of K-12 Online Physical Education

    ERIC Educational Resources Information Center

    Daum, David N.; Woods, Amelia M.

    2015-01-01

    K-12 online physical education (OLPE) is as an educational opportunity in at least 30 states in the US (NASPE, 2006; 2010; 2012). The purpose of this study was to examine physical education teacher educators' perceptions toward and understanding of K-12 OLPE. Bandura's Social Cognitive Theory (1986) served as the theoretical framework for this…

  9. Recognizing Warning Signs of K-12 Christian School Distress That Lead to School Closure

    ERIC Educational Resources Information Center

    Fellers, Ron

    2013-01-01

    The objective of this research was to identify statistically significant warning signs of K12 Christian school distress that can lead to school closure in the areas of leadership, homogeneity of vision and culture, finances, and competition, as described by Fitzpatrick (2002) and Nichols (2006). Twenty-four strong, declining, and closed K-12…

  10. Online Teaching in K-12: Models, Methods, and Best Practices for Teachers and Administrators

    ERIC Educational Resources Information Center

    Bryans-Bongey, Sarah, Ed.; Graziano, Kevin J., Ed.

    2016-01-01

    "Online Teaching in K-12" is the essential hands-on reference and textbook for education professionals seeking success in the planning, design, and teaching of K-12 online courses and programs. This skillfully edited book brings together more than two dozen experts and practitioners to present an array of innovative models and methods,…

  11. Synthetic water soluble di-/tritopic molecular receptors exhibiting Ca2+/Mg2+ exchange.

    PubMed

    Lavie-Cambot, Aurélie; Tron, Arnaud; Ducrot, Aurélien; Castet, Frédéric; Kauffmann, Brice; Beauté, Louis; Allouchi, Hassan; Pozzo, Jean-Luc; Bonnet, Célia S; McClenaghan, Nathan D

    2017-05-23

    Structural integration of two synthetic water soluble receptors for Ca 2+ and Mg 2+ , namely 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) and o-aminophenol-N,N,O-triacetic acid (APTRA), respectively, gave novel di- and tritopic ionophores (1 and 2). As Mg 2+ and Ca 2+ cannot be simultaneously complexed by the receptors, allosteric control of complexation results. Potentiometric measurements established stepwise protonation constants and showed high affinity for Ca 2+ (log K = 6.08 and 8.70 for 1 and 2, respectively) and an excellent selectivity over Mg 2+ (log K = 3.70 and 5.60 for 1 and 2, respectively), which is compatible with magnesium-calcium ion exchange. While ion-exchange of a single Mg 2+ for a single Ca 2+ is possible in both 1 and 2, the simultaneous binding of two Mg 2+ by 2 appears prohibitive for replacement of these two ions by a single Ca 2+ . Ion-binding and exchange was further rationalized by DFT calculations.

  12. Thermoluminescence responses of photon- and electron-irradiated lithium potassium borate co-doped with Cu+Mg or Ti+Mg.

    PubMed

    Alajerami, Y S M; Hashim, S; Ramli, A T; Saleh, M A; Saripan, M I; Alzimami, K; Min Ung, Ngie

    2013-08-01

    New glasses Li2CO3-K2CO3-H3BO3 (LKB) co-doped with CuO and MgO, or with TiO2 and MgO, were synthesized by the chemical quenching technique. The thermoluminescence (TL) responses of LKB:Cu,Mg and LKB:Ti,Mg irradiated with 6 MV photons or 6 MeV electrons were compared in the dose range 0.5-4.0 Gy. The standard commercial dosimeter LiF:Mg,Ti (TLD-100) was used to calibrate the TL reader and as a reference in comparison of the TL properties of the new materials. The dependence of the responses of the new materials on (60)Co dose is linear in the range of 1-1000 Gy. The TL yields of both of the co-doped glasses and TLD-100 are greater for electron irradiation than for photon irradiation. The TL sensitivity of LKB:Ti,Mg is 1.3 times higher than the sensitivity of LKB:Cu,Mg and 12 times less than the sensitivity of TLD-100. The new TL dosimetric materials have low effective atomic numbers, good linearity of the dose responses, excellent signal reproducibility, and a simple glow curve structure. This combination of properties makes them suitable for radiation dosimetry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Health Education Guide: A Design for Teaching K-12.

    ERIC Educational Resources Information Center

    Barrett, Morris

    This teaching guide to health education includes instruction units for grades K-12. Section 1 discusses the need for health education and includes a scope and sequence chart for each of the instruction units. Section 2 consists of instruction units in the areas of physical development, social and emotional development, chemicals and addiction, and…

  14. GOP Candidates Eye Scaling Back Federal K-12 Role

    ERIC Educational Resources Information Center

    Klein, Alyson

    2012-01-01

    Though education has played second fiddle so far to other domestic issues in the race for the Republican presidential nomination, the narrowing field includes GOP candidates with compatible views on scaling back the federal role in K-12, but big contrasts in policy specifics and experience. President Barack Obama, meanwhile, is expected to put a…

  15. Changes of High Sensitivity C-Reactive Protein During Clopidogrel Therapy in Patients Undergoing Percutaneous Coronary Intervention.

    PubMed

    Hajsadeghi, Shokoufeh; Chitsazan, Mandana; Chitsazan, Mitra; Salehi, Negar; Amin, Ahmad; Maleki, Majid; Babaali, Nima; Abdi, Seifollah; Mohsenian, Maryam

    2016-02-01

    The crucial role of inflammation in the development and progression of atherosclerosis has been previously described. However, there is insufficient data available to demonstrate the changes in high sensitivity C-reactive protein (hs-CRP) during clopidogrel therapy. In the present study, we aimed to assess the changes in the inflammatory marker of coronary heart disease, i.e., hs-CRP during clopidogrel therapy, in patients undergoing percutaneous coronary intervention (PCI). We also evaluated the anti-inflammatory effects of clopidogrel, if any, in different groups of patients. The study population included 650 consecutive patients who underwent elective, urgent, or emergent PCI. Patients received a 300-mg loading dose of clopidogrel (Plavix(®)) and aspirin either 24 hours before the planned PCI, or immediately before the procedure in patients with urgent or emergent PCI, followed by a 75-mg daily maintenance dose for up to 12 weeks. At the end of the 12(th) week, hs-CRP was re-assessed. Six hundred-fifty patients including 386 (59.4%) male and 264 (40.6%) female subjects were enrolled in the study. The mean hs-CRP level was 15.36 ± 9.83 mg/L with a median of 14 mg/L (interquartile range 8 to 19.6 mg/L). Female, hypertensive, diabetic, and non-smoking patients had higher reductions in hs-CRP in response to clopidogrel therapy compared to male, non-hypertensive, non-diabetic and smoker patients, respectively (all P < 0.005). The changes in the hs-CRP levels were also statistically different in patients with various index events before PCI (P < 0.001). No significant differences were observed in the mean reduction of hs-CRP between the patients without stent implantation and those with bare metal or drug-eluting stents (P = 0.07), respectively. We found that the use of clopidogrel in patients undergoing PCI had favorable effects on the suppression of hs-CRP. This effect appears to be heightened and more apparent in some group of patients with co-morbidities such as

  16. Soy food intake and treatment outcomes of women undergoing assisted reproductive technology.

    PubMed

    Vanegas, Jose C; Afeiche, Myriam C; Gaskins, Audrey J; Mínguez-Alarcón, Lidia; Williams, Paige L; Wright, Diane L; Toth, Thomas L; Hauser, Russ; Chavarro, Jorge E

    2015-03-01

    To study the relation of dietary phytoestrogens intake and clinical outcomes of women undergoing infertility treatment with the use of assisted reproductive technology (ART). Prospective cohort study. Fertility center. A total of 315 women who collectively underwent 520 ART cycles from 2007 to 2013. None. Implantation, clinical pregnancy, and live birth rates per initiated cycle. Soy isoflavones intake was positively related to live birth rates in ART. Compared with women who did not consume soy isoflavones, the multivariable-adjusted odds ratios of live birth (95% confidence interval) for women in increasing categories of soy isoflavones intake were 1.32 (0.76-2.27) for women consuming 0.54-2.63 mg/d, 1.87 (1.12-3.14) for women consuming 2.64-7.55 mg/d, and 1.77 (1.03-3.03) for women consuming 7.56-27.89 mg/d. Dietary soy intake was positively related to the probability of having a live birth during infertility treatment with ART. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  17. The University Scientist's Role in Promoting Collaborative K-12 Professional Development

    NASA Astrophysics Data System (ADS)

    Schuster, D.; Brown, L. L.; Carlsen, W. S.

    2004-12-01

    Comprehensive K-12 science teacher professional development is dependent upon the successful interaction between the university and K-12 communities (National Research Council, 2001), which can be realized through partnerships between university scientists and K-12 science teachers. This paper will identify some best practices of university scientists in the professional development of science teachers, first by citing the professional development and science education literature (Loucks-Horsley, Hewson, Love, & Stiles, 1998; National Research Council, 1996a, 1996b), and then by highlighting how these best practices were actualized in summer workshops for science educators offered at Penn State. Each summer the Pennsylvania Space Grant Consortium supports seven one-week courses for secondary science teachers taught by university scientists from disciplines representative of NASA's research interests. Approximately 100 teachers enroll in these two-credit, graduate-level workshops from a variety of locations and contexts throughout the United States. These summer courses share a number of important features (duration, general format, teacher recruitment and admission, location, number of participants, etc.), making them a unique dataset for comparative research on science teacher professional development. By recognizing the role of university scientists relating to both practice and standards of professional development, we identify areas in which teachers could be empowered to lead and, alternatively, where scientists and administrators should improve and continue to direct-- both supporting a culture of collaboration that builds K-12 science teacher capacity (Fullan, 2001, 2003; Hawley & Valli, 1999). In our observations and analysis of the evaluations, three best practices, as defined by the literature, appeared to distinguish the exceptional workshops: First, teachers give high marks and make affirmative comments about workshops with clearly presented curricular

  18. Microstructural, mechanical and corrosion characteristics of heat-treated Mg-1.2Zn-0.5Ca (wt%) alloy for use as resorbable bone fixation material.

    PubMed

    Ibrahim, Hamdy; Klarner, Andrew D; Poorganji, Behrang; Dean, David; Luo, Alan A; Elahinia, Mohammad

    2017-05-01

    Mg-Zn-Ca alloys have grabbed most of the recent attention in research attempting to develop an Mg alloy for bone fixation devices due to their superior biocompatibility. However, early resorption and insufficient strength remain the main problems that hinder their use. Heat treatment has previously been thoroughly studied as a post-shaping process, especially after the fabrication of complex parts (e.g. porous structures) by 3D-printing or powder metallurgy. In this work, the effect of heat treatment on Mg-1.2Zn-0.5Ca (wt%) alloy's microstructural, mechanical and corrosion properties was studied. The surface morphology of samples was characterized by optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD). Hardness, compression and tensile tests were conducted, while the in vitro corrosion characteristics of the prepared samples were determined using potentiodynamic polarization (PDP) and immersion tests. It was found that increasing the age hardening duration up to 2-5h increased the heat-treated Mg-1.2Zn-0.5Ca alloy's mechanical properties. Further increase in the age hardening duration did not result in further enhancement in mechanical properties. Similarly, heat treatment significantly altered the Mg-1.2Zn-0.5Ca alloy's in vitro corrosion properties. The corrosion rate of the Mg-1.2Zn-0.5Ca alloy after the heat treatment process was reduced to half of that for the as-cast alloy. XRD results showed the formation of biocompatible agglomerations of hydroxyapatite (HA) and magnesium hydroxide (Mg(OH) 2 ) on the corroded surface of the heat-treated Mg-1.2Zn-0.5Ca alloy samples. The performed heat treatment process had a significant effect on both mechanical and corrosion properties of the prepared Mg-1.2Zn-0.5Ca alloy. The age hardening duration which caused the greatest increase in mechanical and the most slowed corrosion rate for Mg-1.2Zn-0.5Ca alloy material was between 2 and 5h. Copyright © 2017

  19. Course Goals in Mathematics, Grades K-12. Critique Draft.

    ERIC Educational Resources Information Center

    Multnomah County Intermediate Education District, Portland, OR.

    This document is one part of a critique series that deals with the development and evaluation of course goals in six subject matter areas for grades K-12. The series provides an initial pool of course-level goals that are expected to be of considerable value in assisting educators with goal definition related to curriculum planning and…

  20. K-12 Marketplace Sees Major Flow of Venture Capital

    ERIC Educational Resources Information Center

    Ash, Katie

    2012-01-01

    The flow of venture capital into the K-12 education market has exploded over the past year, reaching its highest transaction values in a decade in 2011, industry observers say. They attribute that rise to such factors as a heightened interest in educational technology; the decreasing cost of electronic devices such as tablet computers, laptops,…

  1. Enhancing K-12 School Emergency Management through Community Partnerships

    ERIC Educational Resources Information Center

    Jones, Jay Richard

    2018-01-01

    The ideal school is a safe school. In recent years, the ability of K-12 school districts to mitigate, prepare, protect, respond, and recover from emergencies has gained national attention as a wide variety of manmade and non-manmade disasters have impacted school systems in the United States. An increased emphasis has been placed on how schools…

  2. Addressing Excellence Gaps in K-12 Education. Position Statement

    ERIC Educational Resources Information Center

    National Association for Gifted Children, 2015

    2015-01-01

    Since the passage of the No Child Left Behind Act in 2001, a major objective of federal and state education policy has been to narrow K-12 achievement gaps. This position statement notes that the available data suggest that the singular focus on the most struggling learners has resulted in meaningful progress in closing minimum-competency…

  3. The molecular structure of the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28--a vibrational spectroscopic study.

    PubMed

    Frost, Ray L; López, Andrés; Xi, Yunfei; Scholz, Ricardo; Souza, Larissa; Lana, Cristiano

    2014-07-15

    We have studied the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 using a combination of DEM with EDX and vibrational spectroscopic techniques. The mineral occurs as colorless, gray, yellow to white crystals in the triclinic crystal system. The studied sample is from the Antandrokomby Mine, Sahatany valley, Madagascar. The mineral is prized as a semi-precious jewel. Semi-quantitative chemical composition shows a Al, Ca, borate with minor amounts of K, Mg and Cs. The mineral has a characteristic borate Raman spectrum and bands are assigned to the stretching and bending modes of B, Be and Al. No Raman bands in the OH stretching region were observed. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Intensive lowering of LDL cholesterol with 80 mg versus 20 mg simvastatin daily in 12 064 survivors of myocardial infarction: a double-blind randomised trial

    PubMed Central

    Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) Collaborative Group

    2010-01-01

    Summary Background Lowering of LDL cholesterol reduces major vascular events, but whether more intensive therapy safely produces extra benefits is uncertain. We aimed to establish efficacy and safety of more intensive statin treatment in patients at high cardiovascular risk. Methods We undertook a double-blind randomised trial in 12 064 men and women aged 18–80 years with a history of myocardial infarction. Participants were either currently on or had clear indication for statin therapy, and had a total cholesterol concentration of at least 3·5 mmol/L if already on a statin or 4·5 mmol/L if not. Randomisation to either 80 mg or 20 mg simvastatin daily was done centrally using a minimisation algorithm. Participants were assessed at 2, 4, 8, and 12 months after randomisation and then every 6 months until final follow-up. The primary endpoint was major vascular events, defined as coronary death, myocardial infarction, stroke, or arterial revascularisation. Analysis was by intention to treat. This study is registered, number ISRCTN74348595. Findings 6031 participants were allocated 80 mg simvastatin daily, and 6033 allocated 20 mg simvastatin daily. During a mean follow-up of 6·7 (SD 1·5) years, allocation to 80 mg simvastatin produced an average 0·35 (SE 0·01) mmol/L greater reduction in LDL cholesterol compared with allocation to 20 mg. Major vascular events occurred in 1477 (24·5%) participants allocated 80 mg simvastatin versus 1553 (25·7%) of those allocated 20 mg, corresponding to a 6% proportional reduction (risk ratio 0·94, 95% CI 0·88–1·01; p=0·10). There were no apparent differences in numbers of haemorrhagic strokes (24 [0·4%] vs 25 [0·4%]) or deaths attributed to vascular (565 [9·4%] vs 572 [9·5%]) or non-vascular (399 [6·6%] vs 398 [6·6%]) causes. Compared with two (0·03%) cases of myopathy in patients taking 20 mg simvastatin daily, there were 53 (0·9%) cases in the 80 mg group. Interpretation The 6% (SE 3·5%) reduction in major

  5. Comparison of preoperative carprofen and postoperative butorphanol as postsurgical analgesics in cats undergoing ovariohysterectomy.

    PubMed

    Al-Gizawiy, Mona M; P Rudé, Elaine

    2004-07-01

    To compare carprofen to butorphanol, with regard to postsurgical analgesic effects, duration of analgesia, and adverse side effects. Blinded, randomized clinical study. Seventy-one cats, 0.5-5 years of age, weighing 3.24 +/- 0.61 kg, undergoing ovariohysterectomy (OHE). Cats were premedicated with subcutaneous atropine (0.04 mg kg(-1)), acepromazine (0.02 mg kg(-1)), and ketamine (5 mg kg(-1)). Anesthesia was induced with ketamine (5 mg kg(-1)) and diazepam (0.25 mg kg(-1)) given intravenously, and maintained with isoflurane. There were three treatment groups: group C (4 mg kg(-1) carprofen SC at induction), group B (0.4 mg kg(-1) butorphanol SC at end of surgery), and group S (0.08 mL kg(-1) of sterile saline SC at induction and end of surgery). Behavioral data were collected using a composite pain scale (CPS), prior to surgery (baseline) and 1, 2, 3, 4, 8, 12, 16, 20, and 24 hours post-surgery. Interaction scores were analyzed separately. Cats with CPS scores >12 received rescue analgesia (meperidine, 4 mg kg(-1), intramuscular). Sixty cats completed the study. The CPS scores did not differ significantly between groups C and B at any time period. CPS scores for groups B and C were significantly increased for 12 hours post-surgery, and in group S for 20 hours. Both group C and B CPS scores were significantly lower than group S in this 20-hour postoperative period, except at 4 hours (B and C) and at 3 and 8 hours (B alone). Interaction scores for group C returned to preoperative baseline 4 hours after surgery, while both groups B and S remained increased for at least 24 hours post-surgery. Nine cats required meperidine. In this study, carprofen provided better postsurgical analgesia than butorphanol. Clinical relevance Neither drug completely abolished pain, however preoperative carprofen provided better pain control compared with postoperative butorphanol in the 24-hour period following OHE surgery in cats.

  6. A comparison of epidural buprenorphine plus detomidine with morphine plus detomidine in horses undergoing bilateral stifle arthroscopy.

    PubMed

    Fischer, Berit L; Ludders, John W; Asakawa, Makoto; Fortier, Lisa A; Fubini, Susan L; Nixon, Alan J; Radcliffe, Rolfe M; Erb, Hollis N

    2009-01-01

    To compare the analgesic efficacy of buprenorphine plus detomidine with that of morphine plus detomidine when administered epidurally in horses undergoing bilateral stifle arthroscopy. Prospective, randomized, blinded clinical trial. Twelve healthy adult horses participating in an orthopedic research study. Group M (n = 6) received morphine (0.2 mg kg(-1)) and detomidine (0.15 mg kg(-1)) epidurally; group B (n = 6) received buprenorphine (0.005 mg kg(-1)) and detomidine (0.15 mg kg(-1)) epidurally. Horses received one of two epidural treatments following induction of general anesthesia for bilateral stifle arthroscopy. Heart rate (HR), mean arterial blood pressure (MAP), end-tidal CO(2) (Pe'CO(2)), and end-tidal isoflurane concentrations (E'Iso%) were recorded every 15 minutes following epidural administration. Post-operative assessment was performed at 1, 2, 3, 6, 9, 12, and 24 hours after standing; variables recorded included HR, respiratory rate (f(R)), abdominal borborygmi, defecation, and the presence of undesirable side effects. At the same times post-operatively, each horse was videotaped at a walk and subsequently assigned a lameness score (0-4) by three ACVS diplomates blinded to treatment and who followed previously published guidelines. Nonparametric data were analyzed using Wilcoxon's rank-sum test. Inter- and intra-rater agreement were determined using weighted kappa coefficients. Statistical significance was set at p 12-30), median (range)] breaths per minute was significantly higher than in group M [18 (15-20)] breaths per minute, p = 0.04. In horses undergoing bilateral stifle arthroscopy, these doses of buprenorphine plus detomidine injected epidurally produced analgesia similar in intensity and

  7. Released products of pathogenic bacteria stimulate biofilm formation by Escherichia coli K-12 strains.

    PubMed

    Vacheva, Anna; Ivanova, Radka; Paunova-Krasteva, Tsvetelina; Stoitsova, Stoyanka

    2012-06-01

    It has recently been shown that pathogens with a limited capacity for sessile growth (like some Escherichia coli O157 strains) can benefit from the presence of other bacteria and form mixed biofilms with companion strains. This study addresses the question whether pathogens may influence attached growth of E. coli non-pathogenic strains via secreted factors. We compared the biofilm-modulating effects of sterile stationary-phase culture media of a biofilm non-producing strain of E. coli O157:H, a laboratory biofilm-producing E. coli K-12 strain and a biofilm-forming strain of the pathogen Yersina enterocolitica O:3. Sessile growth was monitored as biomass (crystal violet assay), exopolysaccharide (ELLA) and morphology (scanning electron and confocal laser microscopy). With two of the E. coli K-12 strains stimulation of biofilm formation by all supernatants was achieved, but only the pathogens' secreted products induced biomass increase in some 'biofilm-deficient' K-12 strains. Lectin-peroxidase labeling indicated changes in colanic acid and poly-N-acetylglucosamine amounts in extracellular matrices. The contribution of indole, protein and polysaccharide to the biofilm-modulating activities of the supernatants was compared. Indole, in concentrations equal to those established in the supernatants, suppressed sessile growth in one K-12 strain. Proteinase K significantly reduced the stimulatory effects of all supernatants, indicating a prominent role of protein/peptide factor(s) in biofilm promotion. The amount of released polysaccharides (rPS) in the supernatants was quantitated then comparable quantities of isolated rPS were applied during biofilm growth. The three rPS had notable strain-specific effects with regard to both the strain-source of the rPS and the E. coli K-12 target strain.

  8. Intraperitoneal bupivacaine with or without incisional bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy.

    PubMed

    Kalchofner Guerrero, Karin S; Campagna, Ivo; Bruhl-Day, Rodolfo; Hegamin-Younger, Cecilia; Guerrero, Tomas G

    2016-09-01

    Intraperitoneal (IP) bupivacaine provides postoperative analgesia in dogs undergoing ovariohysterectomy (OHE) alone or in combination with incisional (INC) bupivacaine. This study investigated whether the combination of INC and IP bupivacaine is superior to IP bupivacaine alone. Prospective, randomized, blinded clinical study. Thirty-nine privately owned dogs undergoing OHE, aged 25 ± 23 months and weighing 11.8 ± 5.7 kg. Dogs were premedicated with acepromazine (0.05 mg kg(-1) ) and morphine (0.5 mg kg(-1) ) intramuscularly (IM); anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Carprofen (4 mg kg(-1) ) was administered subcutaneously (SC) after intubation. Bupivacaine (3 mg kg(-1) ) IP was administered before complete closure of the linea alba to all dogs. Dogs were randomly assigned into two groups: group B received bupivacaine (n = 20; 1 mg kg(-1) ) and group S received saline (n = 19; 0.2 mL kg(-1) ) INC as a subcutaneous 'splash' before skin closure. Postoperative analgesia was assessed with a dynamic interactive visual analogue scale, the short form of the Glasgow Composite Pain Scale, and mechanical nociceptive threshold (MNT) measurement at 0.5, 1, 2, 4, 6, 8, 12 and 20 hours after surgery by one blinded observer. Parametric data were tested using t-test; nonparametric data were analysed using the two-sample Wilcoxon test (p < 0.05). There was no significant difference between groups with regard to age, weight, surgical and anaesthetic duration, incision length, sedation and pain scores. MNT values decreased in both groups at all time points as compared with the baseline. No dog required rescue analgesia. No postoperative complications were observed. Bupivacaine IP and carprofen SC after morphine IM did provide satisfactory postoperative analgesia in dogs undergoing OHE with the anaesthetic protocol used. There appears to be no clinical advantage to adding bupivacaine INC. Neither protocol could

  9. Characteristics of Innovation in K12 International Schools in Asia

    ERIC Educational Resources Information Center

    Hale, Jessica A.

    2017-01-01

    This qualitative phenomenological study explored identifying characteristics and necessary components of educational innovation in K12 international schools in Asia. Two research questions guided the exploration of observed characteristics of innovation and global leader's perceptions of components of innovation. The findings suggested observed…

  10. Space Science Field Workshops for K-12 Teacher-Scientist Teams

    NASA Technical Reports Server (NTRS)

    Thompson, P. B.; Kiefer, W. S.; Treiman, A. H.; Irving, A. J.; Johnson, K. M.

    2002-01-01

    In collaboration with NASA Space Grant Consortia and other partners, we developed workshops for K-12 teachers that involve intensive, direct interaction with scientists. Field trips allow informal and spontaneous interaction, encouraging active participation. Additional information is contained in the original extended abstract.

  11. The pregnancy outcome of progestin-primed ovarian stimulation using 4 versus 10 mg of medroxyprogesterone acetate per day in infertile women undergoing in vitro fertilisation: a randomised controlled trial.

    PubMed

    Dong, J; Wang, Y; Chai, W R; Hong, Q Q; Wang, N L; Sun, L H; Long, H; Wang, L; Tian, H; Lyu, Q F; Lu, X F; Chen, Q J; Kuang, Y P

    2017-06-01

    To investigate the clinical outcome and endocrinological characteristics of progestin-primed ovarian stimulation (PPOS) using 4 versus 10 mg of medroxyprogesterone acetate (MPA) per day in infertile women with normal ovary reserve. A randomised parallel controlled trial. Tertiary-care academic medical centre. A cohort of 300 infertile women undergoing in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) treatment. Human menopausal gonadotropin (hMG; 225 iu per day) and MPA (group A, 10 mg per day; group B, 4 mg per day) were started simultaneously from cycle day 3 onwards. Ovulation was co-triggered by human chorionic gonadotropin (hCG; 1000 iu) and gonadotropin-releasing hormone agonist (GnRH agonist; 0.1 mg) when dominant follicles matured. Viable embryos were cryopreserved for later frozen embryo transfer (FET) in both groups. The primary outcome measure was the number of oocytes retrieved. Secondary outcomes included the incidence of a premature surge in luteinising hormone (LH), the number of viable embryos, and clinical pregnancy outcomes. The number of oocytes retrieved and viable embryos were similar between two groups (9.8 ± 6.3 versus 9.6 ± 5.9; 4.2 ± 2.6 versus 3.7 ± 3.0; P > 0.05). No significant difference was found in clinical pregnancy rate (58.0 versus 48.7%) and live birth rate per participant (48.7 versus 42.0%; P > 0.05). No premature LH surge and ovarian hyperstimulation syndrome (OHSS) occurred in either group. Progestin-primed ovarian stimulation (PPOS) using 4 or 10 mg of MPA per day was comparable in terms of the number of oocytes retrieved and pregnancy outcome after FET. The administration of 4 mg of MPA per day was sufficient to prevent an untimely LH rise in women undergoing IVF/ICSI treatment. An RCT confirmed similar pregnancy outcome in P-primed ovarian stimulation with a daily dose of 4 or 10 mg MPA. © 2017 Royal College of Obstetricians and Gynaecologists.

  12. Prophylactic vitamin K for the prevention of vitamin K deficiency bleeding in preterm neonates.

    PubMed

    Ardell, Stephanie; Offringa, Martin; Ovelman, Colleen; Soll, Roger

    2018-02-05

    Vitamin K is necessary for the synthesis of coagulation factors. Term infants, especially those who are exclusively breast fed, are deficient in vitamin K and consequently may have vitamin K deficiency bleeding (VKDB). Preterm infants are potentially at greater risk for VKDB because of delayed feeding and subsequent delay in the colonization of their gastrointestinal system with vitamin K producing microflora, as well as immature hepatic and hemostatic function.  OBJECTIVES: To determine the effect of vitamin K prophylaxis in the prevention of vitamin K deficiency bleeding (VKDB) in preterm infants. We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 11), MEDLINE via PubMed (1966 to 5 December 2016), Embase (1980 to 5 December 2016), and CINAHL (1982 to 5 December 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles. Randomized controlled trials (RCTs) or quasi-RCTs of any preparation of vitamin K given to preterm infants. We evaluated potential studies and extracted data in accordance with the recommendations of Cochrane Neonatal. We did not identify any eligible studies that compared vitamin K to no treatment.One study compared intravenous (IV) to intramuscular (IM) administration of vitamin K and compared various dosages of vitamin K. Three different prophylactic regimes of vitamin K (0.5 mg IM, 0.2 mg vitamin K 1 , or 0.2 mg IV) were given to infants less than 32 weeks' gestation. Given that only one small study met the inclusion criteria, we assessed the quality of the evidence for the outcomes evaluated as low.Intramuscular versus intravenousThere was no statistically significant difference in vitamin K levels in the 0.2 mg IV group when compared to the infants that received either 0.2 or 0.5 mg vitamin K IM (control) on day 5. By day 25, vitamin K 1 levels had declined in all of the groups, but infants

  13. Thermoelectric Properties of Mg2Si0.995Sb0.005 Prepared by the High-Pressure High-Temperature Method

    NASA Astrophysics Data System (ADS)

    Li, Jialiang; Chen, Gang; Duan, Bo; Zhu, Yaju; Hu, Xiaojun; Zhai, Pengcheng; Li, Peng

    2017-05-01

    Mg2Si0.995Sb0.005 compound was prepared by the high-pressure high-temperature (HPHT) method. The simultaneous synthesis and consolidation in one step could be completed in <15 min. The effects of pressure and temperature on the thermoelectric properties of Mg2Si0.995Sb0.005 were analyzed in this work. With the pressure and temperature increasing, the electrical conductivity rises markedly, while the Seebeck coefficient changes slightly, which results in significant enhancement of the power factor. The Mg2Si0.995Sb0.005 sample prepared under the condition of 1073 K and 2 GPa achieves the highest power factor of ˜2.12 × 10-3 W m-1 K-2 at 575 K. As the sample prepared at 973 K and 2 GPa retains a lower thermal conductivity, it obtains the highest thermoelectric figure-of-merit ZT ˜0.62 at 800 K. In conclusion, the HPHT method can serve as a route to prepare Sb-doped Mg2Si thermoelectric materials efficiently.

  14. Alfaxalone or ketamine-medetomidine in cats undergoing ovariohysterectomy: a comparison of intra-operative parameters and post-operative pain.

    PubMed

    Kalchofner Guerrero, Karin S; Reichler, Iris M; Schwarz, Andrea; Jud, Rahel S; Hässig, Michael; Bettschart-Wolfensberger, Regula

    2014-11-01

    To compare post-operative pain in cats after alfaxalone or ketamine- medetomidine anaesthesia for ovariohysterectomy (OHE) and physiologic parameters during and after surgery. Prospective 'blinded' randomized clinical study. Twenty-one healthy cats. Cats were assigned randomly into two groups: Group A, anaesthesia was induced and maintained with alfaxalone [5 mg kg(-1) intravenously (IV) followed by boli (2 mg kg(-1) IV); Group MK, induction with ketamine (5 mg kg(-1) IV) after medetomidine (30 μg kg(-1) intramuscularly (IM)], and maintenance with ketamine (2 mg kg(-1) IV). Meloxicam (0.2 mg kg(-1) IV) was administered after surgery. Basic physiological data were collected. At time T = -2, 0, 0.5, 1, 2, 4, 6, 8, 12, 16, 20, and 24 hours post-operatively pain was assessed by three methods, a composite pain scale (CPS; 0-24 points), a visual analogue scale (VAS 0-100 mm), and a mechanical wound threshold (MWT) device. Butorphanol (0.2 mg kg(-1) IM) was administered if CPS was scored ≥13. Data were analyzed using a general linear model, Kruskal-Wallis analyses, Bonferroni-Dunn test, unpaired t-test and Fisher's exact test as relevant. Significance was set at p < 0.05. VASs were significantly higher at 0.5, 1, 2, 4, and 20 hours in group A; MWT values were significantly higher at 8 and 12 hours in group MK. Post-operative MWT decreased significantly compared to baseline in both groups. There was no difference in CPS at any time point. Five cats required rescue analgesia (four in A; one in MK). Anaesthesia with ketamine-medetomidine was found to provide better post-surgical analgesia than alfaxalone in cats undergoing OHE; however, primary hyperalgesia developed in both groups. Alfaxalone is suitable for induction and maintenance of anaesthesia in cats undergoing OHE, but administration of additional sedative and analgesic drugs is highly recommended. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  15. First-principles investigation for some physical properties of some fluoroperovskites compounds ABF3 (A = K, Na; B = Mg, Zn)

    NASA Astrophysics Data System (ADS)

    Bakri, Badis; Driss, Zied; Berri, Saadi; Khenata, Rabah

    2017-12-01

    In this work, the structural, electronic and optical properties of fluoroperovskite ABF3 (A = K, Na; B = Mg, Zn) were studied using two different approaches: the full-potential linearized augmented plane wave method and the pseudo-potential plane wave scheme in the frame of generalized gradient approximation features such as the lattice constant, bulk modulus and its pressure derivative are reported. The ground state properties of these compounds such as the equilibrium lattice constant and the bulk modulus are in good agreement with the experimental results. The first principles calculations were performed to study the electronic structures of ABF3(A = K, Na; B = Mg, Zn) compounds and the results indicated that these four compounds are indirect band gap insulators. The optical properties are analysed and the source of some peaks in the spectra is discussed. Besides, the dielectric function, refractive index and extinction coefficient for radiation up to 25 eV have also been reported and discussed.

  16. Direct oxygen removal technique for recycling titanium using molten MgCl2 salt.

    PubMed

    Okabe, Toru H; Hamanaka, Yuki; Taninouchi, Yu-Ki

    2016-08-15

    Deoxidation of Ti, or direct removal of O dissolved in metallic Ti, is known to be extremely difficult when Mg is used as the deoxidizing agent. This difficulty arises because the chemical potential of O2, pO2, under Mg/MgO equilibrium is high (approximately 10(-41) atm at 1200 K) and is equivalent to that of Ti containing ∼2 mass% O at 1200 K. Therefore, when deoxidizing Ti to the commercial level of high-grade pure Ti (below 0.05 mass% O) using an Mg reductant at 1200 K, the activity of the reaction product MgO (aMgO) must be decreased to below ∼0.025, which is difficult in practice. In this study, the removal of O in Ti in molten MgCl2 salt using an electrochemical technique was examined at ∼1173 K with the objective of obtaining Ti containing less than 0.05 mass% O. Ti samples and graphite electrodes immersed in molten MgCl2 served as the cathode and anode, respectively. A constant voltage was applied between the electrodes using an external DC source. Molten MgCl2 was employed to produce the deoxidizing agent Mg and to facilitate deoxidation of Ti by decreasing the activity of the reaction product MgO. By applying a voltage of approximately 3.1 V between the electrodes, the chemical potential of Mg in the molten MgCl2 was increased at the surface of the Ti cathode, and the Ti samples were deoxidized. The resulting O species, mainly formed O(2-) dissolved in the molten MgCl2, was removed from the molten salt by reacting with the C anode to form CO (or CO2) gas. Ti wires containing 0.12 mass% O were deoxidized to less than 0.02 mass% O. In some cases, the O concentration in the Ti samples was reduced to the level of 0.01 mass%, which cannot be accomplished using the conventional Kroll process. The possible application of this deoxidation technique to practical industrial recycling processes is discussed.

  17. Are K-12 learners motivated in physical education? A meta-analysis.

    PubMed

    Chen, Senlin; Chen, Ang; Zhu, Xihe

    2012-03-01

    Previous studies devoted to K-12 learner motivation in physical education share a general assumption that students may lack motivation. This meta-analytic study examined published original studies (n = 79) to determine students' motivation level and the association between motivation and outcomes. Original means of motivation measures were converted and aggregated to determine motivation levels. Correlation effect sizes were calculated to determine the association between motivation and outcome measures. The analyses revealed that K-12 students are motivated regardless of the theoretical constructs used in the studies (M > 50). The correlation effect sizes (r = .20-.30, p < .05) indicate a weak association between motivation and outcome. The findings suggest a need to involve meaningful learning and pedagogy variables in motivation research.

  18. Changes in antioxidant status, protein concentration, acetylcholinesterase, (Na+,K+)-, and Mg2+ -ATPase activities in the brain of hyper- and hypothyroid adult rats.

    PubMed

    Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Mourouzis, Iordanis; Varonos, Dennis; Cokkinos, Dennis; Tsakiris, Stylianos

    2005-06-01

    It is a common knowledge that metabolic reactions increase in hyperthyroidism and decrease in hypothyroidism. The aim of this work was to investigate how the metabolic reactions could affect the total antioxidant status (TAS), protein concentration (PC) and the activities of acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+ -ATPase in the brain of hyper- and hypothyroid adult male rats. Hyperthyroidism was induced in rats by subcutaneous administration of thyroxine (25 microg/l00 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. TAS, PC, and enzyme activities were evaluated spectrophotometrically in the homogenated brain of each animal. TAS, PC, and Mg2+ -ATPase activity were found unaffected in hyperthyroidism, while AChE and Na+,K+ -ATPase activities were reduced by 25% (p < 0.01). In contrast, TAS, (Na+,K+)-ATPase and Mg2+-ATPase activities were found to be increased (approx. 23-30%, p < 0.001) in the hypothyroid brain, while AChE activity and PC were shown to be inhibited (approx. 23-30%, p < 0.001). These changes on brain enzyme activities may reflect the different metabolic effects of hyper- and hypothyroidism. Such changes of the enzyme activities may differentially modulate the brain intracellular Mg2+, neural excitability, as well as the uptake and release of biogenic amines.

  19. An Environmental Education Program (K-12), Based on Environmental Encounters

    ERIC Educational Resources Information Center

    Stapp, William B.

    1971-01-01

    Describes a strategy for development and implementation of a comprehensive environmental education program (K-12) which can be integrated into existing curriculum of a school. Environmental encounters" stressed as meaningful approaches to goal achievement. Philosophy of spaceship earth" is fundamental to the program. (LK)

  20. K-shell Photoionization of Na-like to Cl-like Ions of Mg, Si, S, Ar, and Ca

    NASA Technical Reports Server (NTRS)

    Witthoeft, M. C.; Garcia, J.; Kallman, T. R.; Bautista, M. A.; Mendoza, C.; Palmeri, P.; Quinet, P.

    2010-01-01

    We present R-matrix calculations of photoabsorption and photoionization cross sections across the K edge of Mg, Si, S, Ar, and Ca ions with more than 10 electrons. The calculations include the effects of radiative and Auger damping by means of an optical potential. The wave functions are constructed from single-electron. orbital bases obtained using a Thomas-Fermi-Dirac statistical model potential. Configuration interaction is considered among all states up to n = 3. The damping processes affect the resonances converging to the K-thresholds causing them to display symmetric profiles of constant width that smear the otherwise sharp edge at the photoionization threshold. These data are important for the modeling of features found in photoionized plasmas.

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