These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Genetic Evidence for a Molybdopterin-Containing Tellurate Reductase  

PubMed Central

The genetic identity and cofactor composition of the bacterial tellurate reductase are currently unknown. In this study, we examined the requirement of molybdopterin biosynthesis and molybdate transporter genes for tellurate reduction in Escherichia coli K-12. The results show that mutants deleted of the moaA, moaB, moaE, or mog gene in the molybdopterin biosynthesis pathway lost the ability to reduce tellurate. Deletion of the modB or modC gene in the molybdate transport pathway also resulted in complete loss of tellurate reduction activity. Genetic complementation by the wild-type sequences restored tellurate reduction activity in the mutant strains. These findings provide genetic evidence that tellurate reduction in E. coli involves a molybdoenzyme. PMID:23475618

Theisen, Joanne; Zylstra, Gerben J.

2013-01-01

2

EMT - Empirical-mode-decomposition-based Magneto-Telluric Processing  

NASA Astrophysics Data System (ADS)

We present a new Magneto-Telluric (MT) data processing scheme based on an emerging non linear, non stationary time series analysis tool, called the Empirical Mode Decomposition (EMD) or Hilbert-Huang Transform (HHT), to transform data into a non-stationary frequency domain and a robust principal component regression to estimate the most likely MT transfer functions from the data with the 2-? confidence intervals computed by a bootstrap algorithm. Optionally, data quality can be controlled by a physical coherence and a signal power filter. MT sources are assumed to be quasi stationary and therefore a (windowed) Fourier Transform is often applied to transform the time series into the frequency domain in which Transfer Functions (TF) are defined between the electromagnetic field components. This assumption can break down in the presence of noise or when the sources are non stationary, and then TF estimates can become unreliable when obtained through a stationary transform like the Fourier transform. Our TF estimation scheme naturally deals with non stationarity without introducing artifacts and, therefore, potentially can distinguish quasi-stationary sources and non-stationary noise. In contrast to previous works on using HHT for MT processing, we argue the necessity of a multivariate EMD to model the MT problem physically correctly and highlight the resulting possibility to use instantaneous parameters as independent and identically distributed variables. Furthermore, we define a homogenization between data channels of frequency discrepancies due to non stationarity and noise. The TF estimation in the frequency domain bases on a robust principal component analysis in order to find two source polarizations. These two principal components are used as predictor to regress robustly the data channels within a bootstrap algorithm to estimate the Earth's Transfer function with 2-? confidence interval supplied by the measured data.The scheme can be used with and without aid by any number of remote reference stations. The performance of this scheme will be demonstrated on MT data and compared with BIRRP, a widely used MT processing software by Alan Chave.

Neukirch, M.; Garcia, X.

2012-04-01

3

Mineralogical transformations controlling acid mine drainage1 T. Peretyazhko*1  

E-print Network

Mineralogical transformations controlling acid mine drainage1 chemistry2 3 4 5 T. Peretyazhko*1 , J drainage, schwertmannite, mineralogical transformations65 #12;4 1. Introduction66 Acid mine drainage (AMD tetyana.peretyazhko@pnl.gov.35 #12;2 Abstract36 The role of Fe(III) minerals in controlling acid mine

Burgos, William

4

Transformation of chenodeoxycholic acid by thermophilic Geobacillus stearothermophilus.  

PubMed

We performed a series of experiments with Geobacillus stearothermophilus, a thermophile isolated from oil-contaminated soil in the Kuwaiti desert. The organism has a good potential for the transformation of a broad spectrum of organic molecules such as steroids, amino acids, and aromatic hydrocarbons. In the present study, we tested its potential for the transformation of a bile component, chenodeoxycholic acid (CDCA). Five transformed products, namely, cholic acid, methylcholate, methylchenodeoxycholate, 3?-hydroxy-7-oxo-5?-cholanic acid, and 7?-hydroxy-3-oxo-5?-cholanic acid, were the major transformation products catalyzed by G. stearothermophilus. Under aerobic conditions, no evidence of side chain degradation, ring cleavage, or dehydrogenation was found among the metabolites of CDCA. CDCA transformation by a thermophile is reported for the first time. PMID:21838799

Afzal, Mohammad; Oommen, Sosamma; Al-Awadi, Samira

2011-01-01

5

Ultra-low temperature processing of barium tellurate dielectrics  

NASA Astrophysics Data System (ADS)

Ceramics, metals and polymers have unique electrical properties that are combined for electronic devices and systems. It necessitates lower processing temperatures for ceramics to be compatible with metal and polymer systems. In this thesis, the synthesis, crystal structure, and dielectric properties of barium tellurate are studied for temperatures between 500 and 900°C. Barium tellurate dielectric ceramics (BaTe4O9, BaTe 2O5, BaTe2O6, BaTeO3, BaTeO 4, and Ba2TeO5) are extensively investigated as new LTCC (Low-Temperature Cofired Ceramics) dielectric systems integrated with low resistivity metal electrodes such as silver and aluminum for microwave application. Studies on the phase formation and crystal structure through thermal analyses (Differential Scanning Calorimetry and Thermogravimetric Analysis, DSC-TGA) and X-ray diffraction phase analysis attest that barium tellurates are formed in the temperature range of 500 ˜ 900°C, through the sequential phase formations from Te-rich to Ba-rich phases. The oxygen coordination of the tellurium ion progresses from TeO4 to TeO6 via TeO 3+1 and TeO3 with increasing barium content as confirmed by structural analysis using infrared spectroscopy. High density barium tellurate ceramics are achieved at temperatures as low as 550°C, which provides the potential to be co-fired with low-melting aluminum metal electrodes in LTCC processing. Dielectric permittivity, loss, and temperature stability of barium tellurate dielectric ceramics were measured from 100 Hz to 13 GHz. Barium tellurate ceramics exhibit excellent microwave dielectric properties with intermediate dielectric permittivities and high quality factors (Q). The dielectric properties at microwave frequencies are epsilonr = 17.5, Qxf = 54700 GHz, TCf = -90 ppm/°C for BaTe4O9, epsilonr = 21, Qxf = 50300 GHz, TCf = -51 ppm/°C for BaTe2O6, epsilonr = 10, Qxf = 34000 GHz, TCf = -54 ppm/°C for BaTeO3, and epsilonr = 17, Qx f = 49600 GHz, TCf = -124 ppm/°C for Ba 2TeO5. Co-firing studies of barium tellurate ceramics with metal electrodes establish new LTCC systems for microwave devices. Chemical compatibility of barium tellurates with silver electrodes was achieved in the barium rich compositions. Ba2TeO5 was found to be covetable with silver electrodes at 850°C by adding CuO and B2O3 as fluxing agents. During the co-firing, a thin interfacial layer of AgTe is metastable according to the thermodynamic equilibrium between the Ba2TeO5-Ag/Ag 2O pseudo-binary system. A breakthrough LTCC technology with aluminum is based upon the ultra-low processing temperature and chemical compatibility of BaTe4O 9, which enables co-firing and fabrication of multilayer ceramic capacitors (MLCCs) with aluminum inner electrodes. The aluminum base metal electrode (BME) BaTe4O9 MLCCs provide good dielectric properties of epsilonr = 17.5, TCepsilon = 100 ppm/°C, and tan delta = 2.1 x 10-3 (Q ? 500) at 1 MHz, which are suitable for the class-1 MLCCs. Aluminum microstrip ring resonators on the BaTe4O9 substrates realized good electromagnetic performance of the new materials at microwave frequency exhibiting resonant frequency of 2.97 GHz and Q factor of 278.

Kwon, Do-Kyun

6

MICROBIAL TRANSFORMATION OF ESTERS OF CHLORINATED CARBOXYLIC ACIDS  

EPA Science Inventory

Two groups of compounds were selected for microbial transformation studies. In the first group were carboxylic acid esters having a fixed aromatic moiety and an increasing length of the alkyl component. Ethyl esters of chlorine-substituted carboxylic acids were in the second grou...

7

Chemical transformations of Populus trichocarpa during dilute acid pretreatment  

E-print Network

The structural complexity and unique chemical and physical properties of plant cell walls cause plant biomassChemical transformations of Populus trichocarpa during dilute acid pretreatment Shilin Cao and methoxyl group content and these changes were accompanied with an increase in condensed lignin. The dilute

California at Riverside, University of

8

Electrophilic transformations induced by heteropoly acids: applications and structural studies  

Microsoft Academic Search

The transformations of oxygen-containing compounds and hydrocarbons were studied in the presence of heteropoly acids (H4[SiMo12O40], H3[PMo12O40], H4[SiW12O40]and H3[PW12O40]), and a salt (Cs2.5H0.5[PW12O40]). First, the reactions of oxygen-containing compounds were studied including the transformations of monohydroxy compounds (dehydration, derivatization), aliphatic and diary]diols (dehydration, rearrangements), and epoxides (ring opening, isomerization). Reactions of hydrocarbons were also investigated, with emphasis on alkylation reactions.

Béla Török; Árpàd Molnár

1998-01-01

9

Analytical methods based on transformations with hydrochloric acid.  

PubMed

Ultraviolet spectrophotometric methods are described for alpha-ethyl benzhydrol derivatives, 3-trifluoromethyl-alpha-ethyl benzhydrol (flumecinol), 2,5-dimethyl-alpha-ethyl benzhydrol (RGH-3395) an impurity of the latter, (1,4-di-(2,5-dimethyl-phenyl)-1,4-diphenyl-butan-1,4-diol). The methods are based on dehydrations catalysed by hydrochloric acid yielding unsaturated aromatic chromophores. The determination of 2-acetyl-3-phenyl-tetrahydro-1,2,4-oxadiazin-5-one (RGH-4615) is also based on treatment with hydrochloric acid; the chromophoric compound is a benzaldoxime derivative. The hydrochloric acid-catalysed transformation of ethynodiol diacetate to its 3,5-diene derivative enables the parent compound to be determined by gas chromatography. PMID:16867832

Görog, S; Rényei, M; Laukó, A

1983-01-01

10

Atmospheric modelling for the removal of telluric features from infrared planetary spectra  

NASA Astrophysics Data System (ADS)

The effects of telluric absorption on infrared spectra present a problem for the observer. Strong molecular absorptions from species whose concentrations vary with time can be particularly challenging to remove precisely. Yet removing these effects is key to accurately determining the composition of many astronomical objects - planetary atmospheres in particular. Here, we present a method for removing telluric effects based on a modelling approach. The method relies only on observations usually made by the planetary astronomer, and so is directly comparable with current techniques. We use the modelling approach to process observations made of Jupiter, and Saturn's moon Titan and compare the results with those of the standard telluric division technique, finding the modelling approach to have distinct advantages even in conditions regarded as ideal for telluric division.

Cotton, Daniel V.; Bailey, Jeremy; Kedziora-Chudczer, Lucyna

2014-03-01

11

Production of rosmarinic acid and lithospermic acid B in Ti transformed Salvia miltiorrhiza cell suspension cultures  

Microsoft Academic Search

A Ti transformed cell culture of S.miltiorrhiza demonstrated the ability to produce rosmarinic acid (RA) and lithospermic acid B (LAB) as determined by HPLC. A time course of biomass accumulation, phenolic compound formation, medium pH and conductivity as well as sugar, nitrate, ammonium and phosphate uptake was examined both in flask and in bioreactor cultures using hormone free B5 medium

Hui Chen; Feng Chen; Yin-Lin Zhang; Jing-Yuan Song

1999-01-01

12

Iron Transformations Induced by an Acid-Tolerant Desulfosporosinus Species  

PubMed Central

The mineralogical transformations of Fe phases induced by an acid-tolerant, Fe(III)- and sulfate-reducing bacterium, Desulfosporosinus sp. strain GBSRB4.2 were evaluated under geochemical conditions associated with acid mine drainage-impacted systems (i.e., low pH and high Fe concentrations). X-ray powder diffractometry coupled with magnetic analysis by first-order reversal curve diagrams were used to evaluate mineral phases produced by GBSRB4.2 in media containing different ratios of Fe(II) and Fe(III). In medium containing Fe predominately in the +II oxidation state, ferrimagnetic, single-domain greigite (Fe3S4) was formed, but the addition of Fe(III) inhibited greigite formation. In media that contained abundant Fe(III) [as schwertmannite; Fe8O8(OH)6SO4 · nH2O], the activities of strain GBSRB4.2 enhanced the transformation of schwertmannite to goethite (?-FeOOH), due to the increased pH and Fe(II) concentrations that resulted from the activities of GBSRB4.2. PMID:22038606

Bertel, Doug; Peck, John; Quick, Thomas J.

2012-01-01

13

Telluric-line subtraction in high-accuracy velocimetry: a PCA-based approach  

NASA Astrophysics Data System (ADS)

Optical velocimetry has led to the detection of more than 500 planets to date and there is a strong effort to push m/s velocimetry to the near-infrared to access cooler and lighter stars. The presence of numerous telluric absorption lines in the nIR brings an important challenge. As the star's barycentric velocity varies through the year, the telluric absorption lines effectively varies in velocity relative to the star's spectrum by the same amount leading to important systematic RV offsets. We present a novel Principal component analysis-based approach for telluric line subtraction and demonstrated its effectiveness with archival HARPS data for GJ436 and ? Ceti, over parts of the R-band that contain strong telluric absorption lines. The main results are: 1) a better RV accuracy with excluding only a few percentage of the domain, 2) better use of the entire spectrum to measure RV and 3) a higher telescope time efficency by using A0V telluric standard from telescope archive.

Artigau, Étienne; Astudillo-Defru, Nicola; Delfosse, Xavier; Bouchy, François; Bonfils, Xavier; Lovis, Christophe; Pepe, Francesco; Moutou, Claire; Donati, Jean-François; Doyon, René; Malo, Lison

2014-07-01

14

Telluric-line subtraction in high-accuracy velocimetry: a PCA-based approach  

E-print Network

Optical velocimetry has led to the detection of more than 500 planets to date and there is a strong effort to push m/s velocimetry to the near-infrared to access cooler and lighter stars. The presence of numerous telluric absorption lines in the nIR brings an important challenge. As the star's barycentric velocity varies through the year, the telluric absorption lines effectively varies in velocity relative to the star's spectrum by the same amount leading to important systematic RV offsets. We present a novel principal component analysis-based approach for telluric line subtraction and demonstrated its effectiveness with archival HARPS data for GJ436 and {\\tau} Ceti, over parts of the R-band that contain strong telluric absorption lines. The main results are: 1) a better RV accuracy with excluding only a few percentage of the domain, 2) better use of the entire spectrum to measure RV and 3) a higher telescope time efficency by using A0V telluric standard from telescope archive.

Artigau, Étienne; Delfosse, Xavier; Bouchy, François; Moutou, Claire; Donati, Jean-François; Doyon, René; Malo, Lison

2014-01-01

15

Lassen Known Geothermal Resource Area, California: audio-magnetotelluric, telluric profiling, and self-potential studies  

SciTech Connect

During the summer of 1979, geophysical work was done in the Lassen KGRA in northeastern California to assess the geothermal potential of the area. As part of the study, 68 audio-magnetotelluric (AMT) soundings were made and 2 telluric and self-potential (SP) profiles were done. The AMT station locations are shown. The scalar resistivities were contoured for 7.5 and 27 hertz data at north-south and east-west E-line orientations. The contour maps are complex, reflecting both lateral changes in geology and geothermal activity. The locations of the telluric and self-potential traverses are given. The profiles for traverse 1 show varied SP and telluric responses. The variations are probably geologically related with the drop in SP voltage and telluric resistivity on the east end of the traverse caused by a lateral lithology change. The profiles for traverse 2 show a sharp drop in SP voltage combined with a sharp increase in telluric resistivity near station 6. This could be associated with large-scale intrusive features (a ring dike) which trend to the northwest.

Christopherson, K.R.; Hoover, D.B.; Lewis, V.; Radtke, B.; Senterfit, R.M.

1980-01-01

16

Preseismic anomalous telluric current signals observed in Kozu-shima Island, Japan  

PubMed Central

Monitoring of telluric current, which is practically a synonym for geoelectric potential difference, was conducted on Kozu-shima Island about 170 km south of Tokyo from May 14, 1997 to June 25, 2000. During the monitoring period, 19 anomalous telluric current changes (ATCs) were observed. Their possible correlation with nearby earthquakes was statistically examined by assuming various lead times for different ranges of magnitude and focal distance. The best correlation may be obtained for earthquakes with a magnitude greater than 3.0 occurring within 20 km of focal distance. There were 23 such earthquakes, of which 11 were preceded by ATCs within 30 d. Of these 11 earthquakes, preceding ATCs of 5 and 6 were positive and negative polarities of telluric current, respectively. Their epicenters were spatially well clustered in the east and west of the island. These facts were clearly beyond those expected by chance and led to a simple speculative model. PMID:23115337

Orihara, Yoshiaki; Kamogawa, Masashi; Nagao, Toshiyasu; Uyeda, Seiya

2012-01-01

17

Plants having modified response to ethylene by transformation with an ETR nucleic acid  

DOEpatents

The invention includes transformed plants having at least one cell transformed with a modified ETR nucleic acid. Such plants have a phenotype characterized by a decrease in the response of at least one transformed plant cell to ethylene as compared to a plant not containing the transformed plant cell. Tissue and/or temporal specificity for expression of the modified ETR nucleic acid is controlled by selecting appropriate expression regulation sequences to target the location and/or time of expression of the transformed nucleic acid. The plants are made by transforming at least one plant cell with an appropriate modified ETR nucleic acid, regenerating plants from one or more of the transformed plant cells and selecting at least one plant having the desired phenotype.

Meyerowitz, Elliott M. (Pasadena, CA); Chang, Caren (Pasadena, CA); Bleecker, Anthony B. (Madison, WI)

2001-01-01

18

A final report on computed magneto-telluric curves for hypothetical models of crustal structure  

USGS Publications Warehouse

Several mathematical models were investigated to determine the capa-bilities of the magneto-telluric method for determining the resistivity structure of the earth's crust. The model parameters were based on the crust model proposed by Keller (1963). The mathematical technique used was developed by Cagniard (1953). The investigations indicate that a three-layer model approximation of the crust and mantle is the most detailed model warranted in inter-preting the information provided by the magneto-telluric method about the lower crust. Only the thickness of the lower crust can be determined, and not the resistivity.

Pritchard, J.I.

1965-01-01

19

Dissimilatory reduction and transformation of ferrihydrite-humic acid coprecipitates.  

PubMed

Organic matter (OM) is present in most terrestrial environments and is often found coprecipitated with ferrihydrite (Fh). Sorption or coprecipitation of OM with Fe oxides has been proposed to be an important mechanism for long-term C preservation. However, little is known about the impact of coprecipitated OM on reductive dissolution and transformation of Fe(III) (oxyhydr)oxides. Thus, we study the effect of humic acid (HA) coprecipitation on Fh reduction and secondary mineral formation by the dissimilatory Fe(III)-reducing bacterium Shewanella putrefaciens strain CN32. Despite similar crystal structure for all coprecipitates investigated, resembling 2-line Fh, the presence of coprecipitated HA resulted in lower specific surface areas. In terms of reactivity, coprecipitated HA resulted in slower Fh bioreduction rates at low C/Fe ratios (i.e., C/Fe ? 0.8), while high C/Fe ratios (i.e., C/Fe ? 1.8) enhanced the extent of bioreduction compared to pure Fh. The coprecipitated HA also altered the secondary Fe mineralization pathway by inhibiting goethite formation, reducing the amount of magnetite formation, and increasing the formation of a green rust-like phase. This study indicates that coprecipitated OM may influence the rates, pathway, and mineralogy of biogeochemical Fe cycling and anaerobic Fe respiration within soils. PMID:24219167

Shimizu, Masayuki; Zhou, Jihai; Schröder, Christian; Obst, Martin; Kappler, Andreas; Borch, Thomas

2013-12-01

20

Transforming acidic coiled-coil proteins (TACCs) in human cancer.  

PubMed

Fine-tuned regulation of the centrosome/microtubule dynamics during mitosis is essential for faithful cell division. Thus, it is not surprising that deregulations in this dynamic network can contribute to genomic instability and tumorigenesis. Indeed, centrosome loss or amplification, spindle multipolarity and aneuploidy are often found in a majority of human malignancies, suggesting that defects in centrosome and associated microtubules may be directly or indirectly linked to cancer. Therefore, future research to identify and characterize genes required for the normal centrosome function and microtubule dynamics may help us gain insight into the complexity of cancer, and further provide new avenues for prognostic, diagnostics and therapeutic interventions. Members of the transforming acidic coiled-coil proteins (TACCs) family are emerging as important players of centrosome and microtubule-associated functions. Growing evidence indicates that TACCs are involved in the progression of certain solid tumors. Here, we will discuss our current understanding of the biological function of TACCs, their relevance to human cancer and possible implications for cancer management. PMID:23624299

Ha, Geun-Hyoung; Kim, Jung-Lye; Breuer, Eun-Kyoung Yim

2013-08-01

21

Differential Effects of Temperature on Natural Transformation to Erythromycin and Nalidixic Acid Resistance in Campylobacter coli  

Microsoft Academic Search

Campylobacter jejuni and Campylobacter coli are naturally competent, but limited information exists on the impact of environmental conditions on transformation. In this study, we investigated the impact of tempera- ture and microaerobic versus aerobic atmosphere on transformation of C. coli to erythromycin and nalidixic acid resistance. Frequency of transformation was not significantly different between microaerobic (5 to 10% CO2) and

Joo-Sung Kim; Jae-Won Kim; S. Kathariou

2008-01-01

22

Oleanolic acid and ursolic acid inhibit proliferation in transformed rat hepatic oval cells  

PubMed Central

AIM: To investigate H2O2-induced promotion proliferation and malignant transformation in WB-F344 cells and anti-tumor effects of ursolic acid (UA) and oleanolic acid (OA). METHODS: WB-F344 cells were continuously exposed to 7 x 10-7 mol/L H2O2 for 21 d. Observations of cell morphology, colony formation rates, flow cytometric analysis of cell cycle changes and aneuploidy formation indicated that H2O2 was able to induce malignant transformation of WB-F344 cells. We treated malignantly transformed WB-F344 cells with 4 ?mol/L OA or 8 ?mol/L UA for 72 h and analyzed the cell cycle distribution by flow cytometry. RESULTS: MTT assay showed that 7 x 10-7 mol/L H2O2 decreased G1 phase subpopulation from 73.8% to 49.6% compared with the control group, and increased S phase subpopulation from 14.5% to 31.8% (P < 0.05 vs control group). Cell morphology showed that nucleus to cytoplasm ratio increased, many mitotic cells, prokaryotes and even tumor giant cells were shown in H2O2-induced WB-F344 cells. Fluorescence activated cell sorting analysis showed that WB-F344 cell aneuploidy increased to 12% following H2O2 treatment. Flow cytometric analysis of the transformed WB-F344 cells following treatment with OA (4 ?mol/L) and UA (8 ?mol/L) showed that OA increased G1 subpopulation to 68.6%, compared to 49.7% in unexposed cells. UA increased G1 subpopulation to 67.4% compared to 49.7% in unexposed cells (P < 0.05 vs H2O2 model group). CONCLUSION: H2O2 causes the malignant transformation of WB-F344 cells. OA and UA exert anti-tumor effects by inhibiting the proliferation in malignantly transformed WB-F344 cells. PMID:24574810

Han, Yu-Ying; Xue, Xiao-Wei; Shi, Zheng-Ming; Wang, Peng-Yan; Wu, Xin-Rui; Wang, Xue-Jiang

2014-01-01

23

Formation and transformation of amino acids and amino acid precursors by high-velocity impacts  

NASA Astrophysics Data System (ADS)

A wide variety of organic compounds have been found in extraterrestrial bodies such as comets and carbonaceous chondrites. It is plausible that these extraterrestrial bodies carried organic compounds such as amino acids or their precursors to the early Earth. It is claimed, however, that these extraterrestrial organics were destroyed during impacts to the Earth. We therefore examined possible transformation of amino acids and their precursors during high-velocity impacts by using a rail gun "HYPAC" in ISAS. Starting materials used in the impact experiments were (i) aqueous solution of glycine (10 mM or 1.0 M), and (ii) a mixture of ammonia, methanol and water. The target materials were sealed in stainless steel capsules, and shocked by impact with a polycarbonate projectile accelerated with "HYPAC" to the velocities of 2.5 - 7.0 km/s. A part of the products was acid-hydrolyzed. Both hydrolyzed an unhydrolyzed products were analyzed by mass spectrometry, high performance liquid chromatography and capillary electrophoresis and chromatography. When an aqueous solution containing ammonia, methanol and water was shocked by impact at the velocity of 6.4 km/s, a number of amino acids (e.g., serine and glycine) were detected after hydrolysis. The present results suggest that amino acid precursors could be formed during cometary impacts. When glycine solution was used as a starting material, about 40 % of glycine was recovered even after 6 km/s impact. Methylamine and ammonia, which are known as pyrolytic products of glycine, were detected, besides them, diketopiperazine and an unidentified product whose molecular weight was 134, were detected, while no glycine peptides were identified in them. It was shown that the impact processes resulted in the formation of amino acid condensates. Thermal stability of glycine precursor is comparable with glycine. The present results suggest that organic material could survive and/or formed during an impact process. Most of organic compounds in comets and carbonaceous chondrites were complex organic compounds. Laboratory simulations suggest that they contain precursors of amino acids. We are examining possible alteration of such complex precursors of amino acids by high-velocity impacts.

Kaneko, T.; Kobayashi, K.; Yamori, A.

24

Microbial transformation of the anti-diabetic agent corosolic acid.  

PubMed

Biotransformation of corosolic acid (1) by Cochliobolus lunatus and Streptomyces asparaginoviolaceus afforded four metabolites, which were identified by using (1)H NMR, (13)C NMR, DEPT, HSQC, HMBC and NOESY spectral data. Biotransformation of corosolic acid by C. lunatus R.R. Nelson & Haasis CGMCC 3.4381 produced three metabolites: 2?,3?,21?-trihydroxyurs-12-en-28-oic acid (2), 2?,3?,7?,21?-tetrahydroxy-urs-12-en-28-oic acid (3) and 2?,3?-dihydroxy-21-oxours-12-en-28-oic acid (4). Incubation of corosolic acid with growing cultures of S. asparaginoviolaceus CGMCC 4.0175 afforded metabolite 2?,3?,30-trihydroxyurs-12-en-28-oic acid (5). All the metabolites were reported for the first time. The substrate and four metabolites, along with four products obtained previously, were evaluated for their inhibitory effects on ?-glucosidase; all the triterpenes tested showed potent inhibitory effects. PMID:25190540

Feng, Xu; Li, Dai-Ping; Zhang, Ze-Sheng; Chu, Zhi-Yong; Luan, Jie

2014-11-01

25

Estimation of water transport from oscillations of the on-shore telluric field generated by tides  

NASA Astrophysics Data System (ADS)

On-shore measurements of telluric field oscillations have been used together with electric field acquired in a submarine cable crossing a channel (in Aveiro area) to estimate the water transport through the channel. The on-shore N-S dipole was calibrated by correlating the lunar tidal water transport and the corresponding on-shore motionally tidal electric field. A calibration factor of 7350 m 3 s - 1for each mV/km, with motionally induced origin, was estimated. Theoretical polarization ellipses of the electric field with tidal origin and telluric field attenuation during inland propagation agreed very well with observed values. The results showed that it is possible to estimate the water transport from on-shore measurements.

Monteiro Santos, Fernando A.; Nolasco, Rita; Soares, António; Dias, João M.; Bernardo, Ivo

2007-11-01

26

Glass-free low-temperature cofired ceramics: calcium germanates, silicates and tellurates  

Microsoft Academic Search

To reduce the complexity of LTCC systems, and so accelerate the development of LTCC tapes with new functionalities, it is necessary to reduce the number of phases within a particular tape. This can best be done by using glass-free single-phase ceramic systems. We performed a basic characterization of several low-temperature-sintered calcium silicates, germanates and tellurates in order to evaluate their

Matjaz Valant; Danilo Suvorov

2004-01-01

27

Transformation of diols in the presence of heteropoly acids under homogeneous and heterogeneous conditions  

Microsoft Academic Search

1,2-Diols (1,2-propanediol, isomeric 2,3-butanediols and 2,3-dimethyl-2,3-butanediol) readily undergo the pinacol rearrangement to yield the corresponding carbonyl compounds (propanal, 2-butanone and 3,3-dimethyl-2-butanone, respectively) in the presence of heteropoly acids (H4[SiMo12O40], H3[PMo12O40], H4[SiW12O40] and H3[PW12O40]). The selectivity depends on the acid strength and the form of the heteropoly acid catalyst (transformation under homogeneous conditions or in the presence of heteropoly acid supported

Béla Török; Imre Bucsi; Tímea Beregszászi; Irén Kapocsi; Árpád Molnár

1996-01-01

28

The investigation of the dynamics of the phase transformation in triolein and oleic acid under pressure  

NASA Astrophysics Data System (ADS)

An aim of our work is the understanding of processes happening during phase transformations under the pressure in triglycerides and unsaturated fatty acids. Particles of investigated liquids possess the double bond between carbon atoms, which causes the bended shape of the particle and makes its free rotation impossible. This property causes low temperatures of melting point and high temperatures of boiling and also investigated by us phase transformations. For study of the dynamics of phase transformation in these liquids we measured light transmission and light scattering at 90 degrees angle, temperature, permittivity and internal pressure versus time. We applied pressure using computer controlled pump with a stepping motor, which makes increase of the pressure steady. The phase transformation in oleic acid lasts several seconds, in triolein it lasts several minutes. We think that the elongated time of phase transformation is caused by a hooked shape of particles of triolein and the dynamics of that process is determined by the tangling of particles. We checked the influence of smaller particles of oleic acid on the phase transformation by investigating the mixture of these liquids.

Tefelski, D. B.; Siegoczy?ski, R. M.; Rostocki, A. J.; Kos, A.; Ko?ciesza, R.; Wieja, K.

2008-07-01

29

Rapid quantitative determination of free fatty acids in fats and oils by fourier transform infrared spectroscopy  

Microsoft Academic Search

Rapid direct and indirect Fourier transform infrared (FTIR) spectroscopic methods were developed for the determination of\\u000a free fatty acids (FFA) in fats and oils based on both transmission and attenuated total reflectance approaches, covering an\\u000a analytical range of 0.2–8% FFA. Calibration curves were prepared by adding oleic acid to the oil chosen for analysis and measuring\\u000a the C=O band @

A. A. Ismail; F. R. van de Voort; G. Emo; J. Sedman

1993-01-01

30

Enhanced transformation of diphenylarsinic acid in soil under sulfate-reducing conditions.  

PubMed

Diphenylarsinic acid (DPAA) is known to be the major contaminant in soils where diphenylchloroarsine and diphenylcyanoarsine were abandoned after World Wars I and II. In this study, experimental model studies were performed to elucidate key factors regulating the transformation of DPAA under anaerobic soil conditions. The elimination of DPAA in Gleysol soils (Qiqihar and Shindori soils) was more rapid than in Mollisol and Regosol soils (Heihe and Ikarashi soils, respectively) during a 5-week incubation. No clear relationship between decreasing rates of DPAA concentrations and soil Eh values was found. The Ikarashi soil showed the slowest decrease in DPAA concentrations among the four soils, but the transformation of DPAA was notably enhanced by addition of exogenous sulfate together with acetate, cellulose or rice straw. Addition of molybdate, a specific inhibitor of sulfate reduction, resulted in the stagnation of DPAA transformation, suggesting that indigenous sulfate reducers play a role in DPAA transformation under anaerobic conditions. Arsenate, phenylarsonic acid, phenylmethylarsinic acid, diphenylmethylarsine oxide and three unknown compounds were detected as metabolites of DPAA. This is the first study to reveal enhancement of DPAA transformation under sulfate-reducing conditions. PMID:23069334

Guan, Ling; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

2012-11-30

31

Ge2Sb2Te5 Film Fabrication by Tellurization of Chemical Vapor Deposited GeSb  

NASA Astrophysics Data System (ADS)

This paper describes stoichiometric Ge2Sb2Te5 (GST) film fabrication by the process based on chemical vapor deposition (CVD). GST films were fabricated by tellurization after GeSb CVD. This two step process enabled to fill high aspect holes. By applying appropriate precursors and process temperature, the surface morphology of the GST film was significantly improved. The moderate tellurization reaction process might contribute GST formation with maintaining the amorphous structure of the CVD GeSb. We believe this technique is useful for phase change memory application.

Suda, Kohei; Uno, Tomohiro; Miyakawa, Tatsuya; Sawamoto, Naomi; Machida, Hideaki; Ishikawa, Masato; Sudoh, Hiroshi; Ohshita, Yoshio; Ogura, Atsushi

2013-12-01

32

Electrochemical technique and copper-promoted transformations: selective hydroxylation and amination of arylboronic acids.  

PubMed

An efficient and selective electrosynthesis of phenols and anilines from arylboronic acids in aqueous ammonia is achieved in an undivided cell. By simply changing the concentration of aqueous ammonia and the anode potential, good yields of phenols and anilines can be obtained chemoselectively with high reaction rates. We propose that anodic oxidation could have played an important role in these transformations. PMID:23808633

Qi, Hong-Lin; Chen, Dong-Song; Ye, Jian-Shan; Huang, Jing-Mei

2013-08-01

33

Heterogeneous catalysts for the transformation of fatty acid triglycerides and their derivatives to fuel hydrocarbons  

NASA Astrophysics Data System (ADS)

The results of studies devoted to the catalysts for transformation of fatty acid triglycerides and their derivatives to fuel hydrocarbons are presented and described systematically. Various approaches to the use of heterogeneous catalysts for the production of biofuel from these raw materials are considered. The bibliography includes 134 references.

Yakovlev, Vadim A.; Khromova, Sofia A.; Bukhtiyarov, Valerii I.

2011-10-01

34

Functional transformations of bile acid transporters induced by high-affinity macromolecules.  

PubMed

Apical sodium-dependent bile acid transporters (ASBT) are the intestinal transporters that form intermediate complexes with substrates and its conformational change drives the movement of substrates across the cell membrane. However, membrane-based intestinal transporters are confined to the transport of only small molecular substrates. Here, we propose a new strategy that uses high-affinity binding macromolecular substrates to functionally transform the membrane transporters so that they behave like receptors, ultimately allowing the apical-basal transport of bound macromolecules. Bile acid based macromolecular substrates were synthesized and allowed to interact with ASBT. ASBT/macromolecular substrate complexes were rapidly internalized in vesicles, localized in early endosomes, dissociated and escaped the vesicular transport while binding of cytoplasmic ileal bile acid binding proteins cause exocytosis of macromolecules and prevented entry into lysosomes. This newly found transformation process of ASBT suggests a new transport mechanism that could aid in further utilization of ASBT to mediate oral macromolecular drug delivery. PMID:24566561

Al-Hilal, Taslim A; Chung, Seung Woo; Alam, Farzana; Park, Jooho; Lee, Kyung Eun; Jeon, Hyesung; Kim, Kwangmeyung; Kwon, Ick Chan; Kim, In-San; Kim, Sang Yoon; Byun, Youngro

2014-01-01

35

Prevention of cultured rat stellate cell transformation and endothelin-B receptor upregulation by retinoic acid  

PubMed Central

Physiologically, perisinusoidal hepatic stellate cells (HSC) are quiescent and store retinoids. During liver injury and in cell culture, HSC transform into proliferating myofibroblast-like cells that express ?-smooth muscle actin (?-sma) and produce excessive amounts of extracellular matrix. During transformation (also known as activation), HSC are depleted of the retinoid stores, and their expression of the endothelin-1 (ET-1) system is increased. ET-1 causes contraction of transformed HSC and is implicated in their proliferation and fibrogenic activity. In order to understand the association between retinoids, ET-1 and the activation of HSC, we investigated the effect of 13-cis-retinoic acid on the transformation of cultured HSC and the expression of ET-1 system. HSC derived from normal rat liver were maintained for 10–12 days in a medium supplemented with 5% serum and containing 2.5 ?M retinoic acid without or with 50 nM ET-1 (ETA+ETB agonist) or sarafotoxin S6c (ETB agonist). In another set of experiments, cells treated for 10–12 days with vehicle (ethanol) or retinoic acid were challenged with ET-1 or sarafotoxin S6c, and various determinations were made at 24 h. Retinoic acid inhibited transformation and proliferation of HSC as assessed by morphological characteristics, expression of ?-sma, bromodeoxyuridine incorporation and cell count. Retinoic acid also prevented upregulation of ETB receptors without affecting ET-1 or ETA expression. Total protein synthesis ([3H]leucine incorporation), collagen ? types I mRNA expression and collagen synthesis ([3H]proline incorporation) were lower in retinoic acid-treated cells. Although ET-1-treated cells were morphologically similar to the control cells, their expression of ?-smooth muscle actin was significantly inhibited. The presence of retinoic acid in the medium during treatment with ET-1 caused further reduction in the expression of ?-smooth muscle actin. ET-1 and sarafotoxin S6c stimulated total protein synthesis in vehicle- and retinoic acid-treated cells, but collagen synthesis only in the latter. These results showing prevention of HSC activation and negative regulation of ETB receptor expression in them by retinoic acid may have important pathophysiologic implications. PMID:12813000

Chi, Xuedong; Anselmi, Kristin; Watkins, Simon; Gandhi, Chandrashekhar R

2003-01-01

36

Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells  

PubMed Central

Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

Gottlicher, Martin; Minucci, Saverio; Zhu, Ping; Kramer, Oliver H.; Schimpf, Annemarie; Giavara, Sabrina; Sleeman, Jonathan P.; Lo Coco, Francesco; Nervi, Clara; Pelicci, Pier Giuseppe; Heinzel, Thorsten

2001-01-01

37

TRANSFORMATION  

SciTech Connect

Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

LACKS,S.A.

2003-10-09

38

[Proteomic analysis of Bacillus subtilis 168 transforming cis-propenylphosphonic acid to fosfomycin].  

PubMed

In this study, we investigated the mechanism of transformation by Bacillus subtilis strain 168 by proteomic analysis. B. subtilis strain 168 was able to stereoselectively transform cis-propenylphosphonic acid (cPPA) to fosfomycin. The maximal fosfomycin production was 816.6 microg/mL after two days cultivation, with a conversion rate of 36.05%. We separated the whole cellular proteins by two-dimensional gel electrophoresis (2-DE) method, and 562 protein spots were detected in the presence of cPPA in the medium, while 527 protein spots were detected in the absence of cPPA. Of them, 98 differentially expressed protein spots were found. Among them, 52 proteins were up-regulated whereas 20 were down-regulated in the presence of cPPA in the medium, and 26 induced at the presence of cPPA. The differentially expressed proteins were analyzed by combined MS and MS/MS methods. Eighty protein spots, including 45 up-regulated proteins, 17 down-regulated proteins, and 18 induced by cPPA were identified. Based on the results of proteomic analysis, we postulated two steps of transformation: in the first step, cPPA was hydrated to 2-hydroxypropylphosphonic acid; in the second step, 2-hydroxypropylphosphonic acid was transformed to fosfomycin via a dehydrogenation reaction. PMID:24063234

Xie, Fuhong; Chao, Yapeng; Shi, Jiaji; Zhang, Guoqing; Yang, Jing; Qian, Shijun

2013-06-01

39

Anti-transforming nature of ascorbic acid and its derivatives examined by two-stage cell transformation using BALB/c 3T3 cells.  

PubMed

The anti-transforming effects of sodium ascorbate and its stable derivatives were examined in the two-stage transformation assay. When BALB/c 3T3 cells were treated with 0.2 microg/ml 20-methylcholanthrene as an initiator, and 100 ng/ml 12-O-tetradecanoylphorbol-13-acetate as a promoter, the addition at the promotion stage of L-ascorbic acid-2-phosphate ester magnesium (APM) was most marked in the inhibition of transformation. The inhibitory effects of sodium ascorbate and ascorbic acid-2-glucoside (AG) were comparable, but weaker than those of APM; L (+)-ascorbic acid-2-sulfate ester disodium 2H(2)O showed little effect. When phorbol 12, 13-didecanoate or tumor necrosis factor alpha (TNF-alpha) were used as promoters, APM also effectively suppressed transformation. PMID:11098084

Tsuchiya, T; Kato-Masatsuji, E; Tsuzuki, T; Umeda, M

2000-11-10

40

Retinoic acid induces transforming growth factor-beta 2 in cultured keratinocytes and mouse epidermis.  

PubMed Central

We have studied the functional interaction between retinoic acid and transforming growth factor-beta (TGF-beta), using the mouse epidermis as a model system. Treatment with retinoic acid increases expression of TGF-beta 2 in cultured keratinocytes in vitro, as well as in the epidermis in vivo. This TGF-beta 2 is secreted in a biologically active form that can bind to surface receptors, in contrast to most other conditions in which TGF-beta is secreted in a latent form. Specific antibodies to TGF-beta 2 partially reverse the ability of retinoic acid to inhibit DNA synthesis in cultured keratinocytes. The regulation of TGF-beta 2 expression by retinoic acid may have important physiological and pharmacological roles in the maintenance of epidermal homeostasis. Images PMID:2519621

Glick, A B; Flanders, K C; Danielpour, D; Yuspa, S H; Sporn, M B

1989-01-01

41

Inhibition of Myc-induced cell transformation by brain acid-soluble protein 1 (BASP1)  

PubMed Central

Cell transformation by the Myc oncoprotein involves transcriptional activation or suppression of specific target genes with intrinsic oncogenic or tumor-suppressive potential, respectively. We have identified the BASP1 (CAP-23, NAP-22) gene as a novel target suppressed by Myc. The acidic 25-kDa BASP1 protein was originally isolated as a cortical cytoskeleton-associated protein from rat and chicken brain, but has also been found in other tissues and subcellular locations. BASP1 mRNA and protein expression is specifically suppressed in fibroblasts transformed by the v-myc oncogene, but not in cells transformed by other oncogenic agents. The BASP1 gene encompasses 2 exons separated by a 58-kbp intron and a Myc-responsive regulatory region at the 5? boundary of untranslated exon 1. Bicistronic expression of BASP1 and v-myc from a retroviral vector blocks v-myc-induced cell transformation. Furthermore, ectopic expression of BASP1 renders fibroblasts resistant to subsequent cell transformation by v-myc, and exogenous delivery of the BASP1 gene into v-myc-transformed cells leads to significant attenuation of the transformed phenotype. The inhibition of v-myc-induced cell transformation by BASP1 also prevents the transcriptional activation or repression of known Myc target genes. Mutational analysis showed that the basic N-terminal domain containing a myristoylation site, a calmodulin binding domain, and a putative nuclear localization signal is essential for the inhibitory function of BASP1. Our results suggest that down-regulation of the BASP1 gene is a necessary event in myc-induced oncogenesis and define the BASP1 protein as a potential tumor suppressor. PMID:19297618

Hartl, Markus; Nist, Andrea; Khan, M. Imran; Valovka, Taras; Bister, Klaus

2009-01-01

42

Endonuclease from Micrococcus luteus which has activity toward ultraviolet-irradiated deoxyribonucleic acid: its action on transforming deoxyribonucleic acid.  

PubMed

An endonuclease purified from Micrococcus luteus makes single-strand breaks in ultraviolet (UV)-irradiated, native deoxyribonucleic acid (DNA). The purified endonuclease is able to reactivate UV-inactivated transforming DNA of Haemophilus influenzae, especially when the DNA is assayed on a UV-sensitive mutant of H. influenzae. After extensive endonuclease action, there is a loss of transforming DNA when assayed on both UV-sensitive and -resistant cells. The endonuclease does not affect unirradiated DNA. The results indicate that the endonuclease function is involved in the repair of biological damage resulting from UV irradiation and that the UV-sensitive mutant is deficient in this step. We interpret the data as indicating that the various steps in the repair of DNA must be well coordinated if repair is to be effective. PMID:4314478

Setlow, R B; Setlow, J K; Carrier, W L

1970-04-01

43

Transformers  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Transformers, is the ninth chapter in Volume II âÂÂAlternating Current (AC). A few of the topics covered in this chapter include: Mutual inductance and basic operation; Step-up and Step-down transformers; Electrical isolation; Phasing; Winding configurations; Voltage Regulation; and finally, Special transformers and applications.. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-03

44

Gallium(III) triflate: an efficient and a sustainable Lewis acid catalyst for organic synthetic transformations.  

PubMed

Green chemical processes play a crucial role in sustainable development, and efficient recyclable catalysts that can be conveniently applied in various chemical reactions are the key elements for the development of sustainable synthetic processes. Many organic transformations rely on Lewis and Brønsted acid catalysts, and such molecules have been widely studied in organic synthesis. Over the years, researchers have looked for Lewis acid catalysts that provide high selectivity and high turnover frequency but are also stable in aqueous media and recoverable. Since the first preparation of trifluoromethanesulfonic acid by Hazeldine (triflic acid, HOTf), researchers have synthesized and used numerous metal triflates in a variety of organic reactions. Even though the rare earth metal triflates have played a major role in these studies, the majority of rare earth triflates lack one or more of the primary properties of sustainable catalysts: low cost and easy availability of the metals, easy preparation of triflates, aqueous/thermal stability, recyclability, and catalytic efficiency. In this Account, we describe the synthetic applications of Ga(OTf)(3) and its advantages over similar catalysts. Ga(OTf)(3) can be conveniently prepared from gallium metal or gallium chloride in excess of trifluoromethanesulfonic acid (triflic acid) under reflux. Among many Lewis acid catalysts recently studied, Ga(OTf)(3) is water tolerant and soluble and requires very low catalyst loading to drive various acid-catalyzed reactions including Friedel-Crafts alkylation, hydroxyalkylation, and acylation selectively and efficiently. In many reactions Ga(OTf)(3) demonstrated high chemo- and regioselectivity, high yields, excellent stability, and recyclability. We successfully synthesized many biologically active heterocycles and their fluoroanalogs under mild conditions. Many challenging reactions such as the ketonic Strecker reactions proceed efficiently via Ga(OTf)(3) catalysis. Because it is stable in water, this catalyst provides the opportunity to study substrates and develop new synthetic protocols in aqueous media, significantly reducing the production of hazardous waste from organic solvents and toxic catalyst systems. PMID:22148160

Prakash, G K Surya; Mathew, Thomas; Olah, George A

2012-04-17

45

Production and transformation of dissolved neutral sugars and amino acids by bacteria in seawater  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) in the ocean consists of a heterogeneous mixture of molecules, most of which are of unknown origin. Neutral sugars and amino acids are among the few recognizable biomolecules in DOM, and the molecular composition of these biomolecules is shaped primarily by biological production and degradation processes. This study provides insight into the bioavailability of biomolecules as well as the chemical composition of DOM produced by bacteria. The molecular compositions of combined neutral sugars and amino acids were investigated in DOM produced by bacteria and in DOM remaining after 32 days of bacterial degradation. Results from bioassay incubations with natural seawater (sampled from water masses originating from the surface waters of the Arctic Ocean and the North Atlantic Ocean) and artificial seawater indicate that the molecular compositions following bacterial degradation are not strongly influenced by the initial substrate or bacterial community. The molecular composition of neutral sugars released by bacteria was characterized by a high glucose content (47 mol %) and heterogeneous contributions from other neutral sugars (3-14 mol %). DOM remaining after bacterial degradation was characterized by a high galactose content (33 mol %), followed by glucose (22 mol %) and the remaining neutral sugars (7-11 mol %). The ratio of D-amino acids to L-amino acids increased during the experiments as a response to bacterial degradation, and after 32 days, the D/L ratios of aspartic acid, glutamic acid, serine and alanine reached around 0.79, 0.32, 0.30 and 0.51 in all treatments, respectively. The striking similarity in neutral sugar and amino acid compositions between natural (representing marine semi-labile and refractory DOM) and artificial (representing bacterially produced DOM) seawater samples, suggests that microbes transform bioavailable neutral sugars and amino acids into a common, more persistent form.

Jørgensen, L.; Lechtenfeld, O. J.; Benner, R.; Middelboe, M.; Stedmon, C. A.

2014-10-01

46

1990-1996 Nucleic Acids Research, 1995, Vol. 23, No. 11 Transformation of Escherichia coli with large DNA  

E-print Network

1990-1996 Nucleic Acids Research, 1995, Vol. 23, No. 11 Transformation of Escherichia coli interest in thetransformation of large DNA, i.e. molecules >100 kb. We have used DNA from bacterial in their uptake of240 kb DNA byas much as 30-fold. Even with a host strain that transforms relatively well

Franks, Robert

47

Recovery of donor deoxyribonucleic acid marker activity from eclipse in pneumococcal transformation.  

PubMed

After the uptake of deoxyribonucleic acid (DNA), donor marker-transforming activity is temporarily lost. Restoration of the activity by annealing in vitro supports the idea that donor DNA is single-stranded at this stage. Kinetics of in vivo recovery from eclipse were examined for various markers at three temperatures. Sigmoidal recovery curves at lower temperatures indicate that the process consists of several steps. Rate of recovery was found to depend on the nature of the donor marker. Single-site markers recover much more rapidly than multisite markers corresponding to recipient deletions. Single-site markers vary somewhat in recovery rate, with rapidity of recovery inversely related to integration efficiency. Appearance of a recombinant-transforming activity lags only slightly behind recovery of its constituent donor marker. PMID:4381633

Ghei, O K; Lacks, S A

1967-03-01

48

Flux calibration of medium-resolution spectra from 300 nm to 2500 nm: Model reference spectra and telluric correction  

E-print Network

While the near-infrared wavelength regime is becoming more and more important for astrophysics there is a marked lack of spectrophotometric standard star data that would allow the flux calibration of such data. Furthermore, flux calibrating medium- to high-resolution \\'echelle spectroscopy data is challenging even in the optical wavelength range, because the available flux standard data are often too coarsely sampled. We will provide standard star reference data that allow users to derive response curves from 300nm to 2500nm for spectroscopic data of medium to high resolution, including those taken with \\'echelle spectrographs. In addition we describe a method to correct for moderate telluric absorption without the need of observing telluric standard stars. As reference data for the flux standard stars we use theoretical spectra derived from stellar model atmospheres. We verify that they provide an appropriate description of the observed standard star spectra by checking for residuals in line cores and line o...

Moehler, S; Freudling, W; Giammichele, N; Gianninas, A; Gonneau, A; Kausch, W; Lancon, A; Noll, S; Rauch, T; Vinther, J

2014-01-01

49

Complexation of chitosan with acetic acid according to Fourier transform Raman spectroscopy data  

NASA Astrophysics Data System (ADS)

The results of the interaction between the protonated chitosan (CHI) macromolecule and the acetate ion in dilute acetic acid solutions were studied by Fourier transform Raman spectroscopy and quantum-chemical modeling. The complexation of CHI with the acetate ion showed itself as the 934 cm-1 band in the Raman spectrum, which suggests the formation of [CHI+ · CH3COO-] type ion pairs. It was concluded that a comparative analysis of the integrated intensities of the Raman bands in the range 880-940 cm-1 makes it possible to judge about the relative content of hydrated acetate ions, CHI macromolecules of the [CHI+ · CH3COO-] complex, and acetic acid molecules not involved in CHI protonation.

Mikhailov, G. P.; Tuchkov, S. V.; Lazarev, V. V.; Kulish, E. I.

2014-06-01

50

Experimental dissolution vs. transformation of micas under acidic soil conditions: Clues from boron isotopes  

NASA Astrophysics Data System (ADS)

Minerals in soils evolve through contact with water and other weathering agents (protons, organic acids and ligands) from the atmosphere or released by the surrounding vegetation and associated fauna. Determining the respective contribution of these agents to weathering budgets and the mechanisms by which they interact with soil minerals is a key step toward obtaining refined models of soil development, plant/mineral interactions and, ultimately, soil sustainability. To test the influence of different chemical agents on the processes of mica weathering (dissolution and transformation), we conducted a series of laboratory flow-through experiments on biotite using three chemical groups of reactants found in forest soils: protons (HCl), organic acids (citric acid) and ligands (siderophores). These experiments were performed at two different pH values (pH 3 and pH 4.5) for 37 days at 20 °C. Biotite was chosen as a test-mineral because it is reactive with acids and water and because it is commonly found in granite soils. To investigate the weathering reactions, the chemical and isotopic compositions of B (?11B) and the concentrations of predominant cation (Si, Al, Mg, K and Fe) were monitored in the outflowing solutions. The choice of B as a proxy for weathering processes is based on the fact that B is located in different crystallographic sites in biotite (interlayers and structural sites, named I- and S-sites, respectively). We observed a large ?11B contrast between these sites (?11BS-I sites˜80‰), which allows for a precise quantification of the respective contribution of I- and S-sites to B released during biotite weathering. The individual reaction rates for these crystallographic sites were inferred from the B chemical and isotopic compositions of the outflowing solutions. A comparison with the major elements reveals that B is preferentially released to solution under all tested experimental conditions (up to 4 times more), particularly in the presence of siderophores. A major finding of the present work is that the dissolution of ?11B is shown to be highly dependent on the nature of the weathering agent: the presence of citric acid leads to a near-stoichiometric contribution of I- and S-sites to dissolved B, whereas the presence of siderophores results in an almost exclusive release of B from the I-sites, which indicates a mineral transformation without significant dissolution. The presence of HCl leads to an intermediate situation that shows a higher B reactivity from the I-sites than from the S-sites, indicating that biotite minerals transform faster than they dissolve. Because the dissolution reactions imply the destruction of the mineral structure, whereas transformation reactions are non-destructive, assessing the proportions in which minerals evolve by dissolution and transformation reactions has important implications for predicting plant/mineral interactions and soil sustainability.

Voinot, A.; Lemarchand, D.; Collignon, C.; Granet, M.; Chabaux, F.; Turpault, M.-P.

2013-09-01

51

Radiation-induced neoplastic transformation of C3H10T1/2 cells is suppressed by ascorbic acid  

SciTech Connect

X-ray induced transformation of C3H10T1/2 cells was suppressed in a concentration-dependent manner by administration of ascorbic acid after irradiation (0.1-20 micrograms/ml for the first week) in the culture medium. The dose-response curve was shifted about 60% downward and was slightly steeper in the presence of ascorbic acid (5 micrograms/ml for the first week) than in its absence. The 1-week treatment procedure revealed that cells initiated by radiation remained susceptible to ascorbic acid until the time of morphological phenotype expression. The neoplastically transformed phenotype expressed after incubation for 8 weeks could no longer be suppressed by ascorbic acid even after culture transfer. Similarly, the neoplastically transformed phenotype suppressed for 8 weeks by ascorbic acid treatment was not subsequently expressed in the absence of ascorbic acid. On the basis of the oxygen-detoxifying nature of ascorbic acid, we postulated that expression of the neoplastically transformed phenotype is promoted by reactive oxygen species and peroxy radicals generated in cells during the whole assay period. The data may be useful as a guide for chemopreventive efforts against radiation carcinogenesis.

Yasukawa, M.; Terasima, T.; Seki, M. (National Institute of Radiological Sciences, Chiba (Japan))

1989-12-01

52

A Rare Phaeodactylum tricornutum Cruciform Morphotype: Culture Conditions, Transformation and Unique Fatty Acid Characteristics  

PubMed Central

A rare Phaeodactylum tricornutum cruciform morphotype was obtained and stabilized with a proportion of more than 31.3% in L1 medium and is reported for the first time. Long-term culture and observation showed that the cruciform morphotype was capable of transforming to the oval form following the degeneration of arms by two processes. After three months of culture, four morphotypes existed in a relatively stable proportion in culture for six months (10.5% for oval, 11.3% for fusiform, 37.2% for triradiate and 41.0% for cruciform). Low temperature was particularly beneficial for cruciform cell formation. As the culture temperature decreased from 25°C to 10°C, the percentage of the cruciform morphotype increased from 39.1% to 55.3% approximately. The abundant cruciform cells endowed this strain with unique fatty acid characteristics. The strain cultured at 15°C showed both maximum content of neutral lipid in a single cell and total yield. The maximum content of fatty acid methyl esters was C16:1 for Phaeodactylum tricornutum cultured at four temperatures (43.82% to 50.82%), followed by C16:0 (20.47% to 22.65%). Unique fatty acid composition endowed this strain with excellent quality for biodiesel production. PMID:24710200

He, Liyan; Han, Xiaotian; Yu, Zhiming

2014-01-01

53

Determination of acid number and base number in lubricants by Fourier transform infrared spectroscopy.  

PubMed

This paper describes the development of practical Fourier transform infrared (FT-IR) methods for the determination of acid number (AN) and base number (BN) in lubricants through the combined use of signal transduction via stoichiometric reactions and differential spectroscopy to circumvent matrix effects. Trifluoroacetic acid and potassium phthalimide were used as stoichiometric reactants to provide infrared (IR) signals proportional to the basic and acidic constituents present in oils. Samples were initially diluted with 1-propanol, then split, with one half treated with the stoichiometric reactant and the other half with a blank reagent, their spectra collected, and a differential spectrum obtained to ratio out the invariant spectral contributions from the sample. Quantitation for AN and BN was based on measurement of the peak height of the v(C = O) or v(COO) absorptions, respectively, of the products of the corresponding stoichiometric reactions, yielding a standard error of calibration of < 0.1 mg KOH/g oil. The AN/BN FT-IR methods were validated by the analysis of a wide range of new and used oils supplied by third parties, which had been analyzed by ASTM methods. Good correlations were obtained between the chemical and FT-IR methods, indicating that the measures are on the whole comparable. From a practical perspective, these new FT-IR methods have significant advantages over ASTM titrimetric methods in terms of environmental considerations, sample size, and speed of analysis, as well as the variety of oil types that can be handled. FT-IR analysis combining stoichiometric signal transduction with differential spectroscopy may be of wider utility as an alternative to titration in the determination of acid or basic constituents in complex nonaqueous systems. PMID:14658158

van de Voort, F R; Sedman, J; Yaylayan, V; Saint Laurent, C

2003-11-01

54

Small interfering ribonucleic acid induces liquid-to-ripple phase transformation in a phospholipid membrane  

NASA Astrophysics Data System (ADS)

Small interfering ribonucleic acid (siRNA) molecules play a pivotal role in silencing gene expression via the RNA interference mechanism. A key limitation to the widespread implementation of siRNA therapeutics is the difficulty of delivering siRNA-based drugs to cells. Here, we examine changes in the structure and dynamics of a dipalmitoylphosphatidylcholine bilayer in the presence of a siRNA molecule and mechanical barriers to siRNA transfection in the bilayer. Our all-atom molecular dynamics simulation shows that siRNA induces a liquid crystalline-to-ripple phase transformation in the bilayer. The ripple phase consists of a major region of non-interdigitated and a minor region of interdigitated lipid molecules with an intervening kink. In the ripple phase, hydrocarbon chains of lipid molecules have large compressive stresses, which present a considerable barrier to siRNA transfection.

Choubey, Amit; Nomura, Ken-ichi; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

2014-09-01

55

Predicting subcellular location of apoptosis proteins with pseudo amino acid composition: approach from amino acid substitution matrix and auto covariance transformation  

Microsoft Academic Search

Apoptosis proteins are very important for understanding the mechanism of programmed cell death. Obtaining information on subcellular\\u000a location of apoptosis proteins is very helpful to understand the apoptosis mechanism. In this paper, based on amino acid substitution\\u000a matrix and auto covariance transformation, we introduce a new sequence-based model, which not only quantitatively describes\\u000a the differences between amino acids, but also

Xiaoqing Yu; Xiaoqi Zheng; Taigang Liu; Yongchao Dou; Jun Wang

56

Determination by fourier transform Raman spectroscopy of conjugated linoleic acid in I2-photoisomerized soybean oil.  

PubMed

The potential of Fourier transform (FT)-Raman spectroscopy to quantify the total conjugated linoleic acid (CLA) content was evaluated to find a technique for the routine control of CLA synthesis by chemical procedures. The calibration and validation samples were obtained by photoisomerization of linoleic acid contained in soybean oil. The catalyst was iodine (I(2)), and the light source was the green line (514.5 nm) of an argon ion laser. The criteria to select the best partial least-squares (PLS) calibration model were a low standard error of prediction (SEP), a high correlation coefficient (R), and the selection of relevant variables of the Raman spectrum to reduce spectral interferences. The total CLA content of the 22 samples ranged from 0.05 to 3.28% of total lipids. The best PLS calibration model was obtained with three optimal factors, a SEP of 0.22, and a R of 0.97. This calibration model was obtained after baseline correction of the CC stretching region (1642-1680 cm(-1)), which contained sufficient spectral information for reliable CLA quantification. PMID:19588975

Bernuy, Bruno; Meurens, Marc; Mignolet, Eric; Turu, Christine; Larondelle, Yvan

2009-08-12

57

Fourier transform infrared spectroscopy and differential scanning calorimetry studies of fatty acid homogeneous ceramide 2.  

PubMed

Ceramides provide a major component of the barrier function of skin. An understanding of barrier organization requires a detailed characterization of ceramide phase behavior and molecular interactions. Toward this end, Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) studies of ceramide 2 analogues (non-hydroxylated fatty acid N-acyl sphingosines) of specific chain lengths (C(14), C(16), C(18), C(20)) are presented. In addition, the molecular interactions of the individual chains in each molecule are elucidated through thermotropic FTIR studies of derivatives possessing perdeuterated fatty acid chains. DSC data showed a much smaller chain length variation (for the C(16), C(18), C(20) derivatives) in the main order-disorder transition temperature (approx. 93+/-1 degrees C) than is observed in the corresponding series of phosphatidylcholines, consistent with minimal ceramide hydration. The temperature dependence of the methylene stretching and scissoring modes revealed a solid-solid phase transition at 20-25 degrees C below the main order-disorder transition accompanied by chain packing alterations from orthorhombic-->hexagonal subcells. The chain packing transition was accompanied by enhanced penetration of water into the polar region. This was deduced from the temperature dependence of the amide I and II modes, which provide direct evidence for H-->D exchange. The CD(2) scissoring mode splitting of the deuterated fatty acid constituent of the C(16), C(18), C(20) chains revealed preferential segregation of microdomains (3-5 chains) of this species within the orthorhombic phase. In contrast, the sphingosine base chains appeared to be sufficiently separated so as to inhibit interchain vibrational coupling between them. FTIR spectroscopy provides a convenient means for characterizing domain formation, chain packing, and hydration sites of these phases, which are highly ordered under physiological conditions. PMID:11018673

Chen, H; Mendelsohn, R; Rerek, M E; Moore, D J

2000-09-29

58

Evaluation of an alternative D-amino acid\\/DAAO selection system for transformation in apple (Malusdomestica Borkh.)  

Microsoft Academic Search

SUMMARY The conventional selection system for apple transformation is based on the selectable marker gene, nptII, encoding antibiotic resistance against kanamycin. We tested an alternative selection system based on the use of D-amino acids using the gene, D-amino acid oxidase 1 (dao1) as the selectable marker, in order to avoid the presence of antibiotic resistance genes in the resulting transgenic

C. HÄTTASCH; H. FLACHOWSKY; M.-V. HANKE

59

Identify submitochondria and subchloroplast locations with pseudo amino acid composition: Approach from the strategy of discrete wavelet transform feature extraction  

Microsoft Academic Search

It is very challenging and complicated to predict protein locations at the sub-subcellular level. The key to enhancing the prediction quality for protein sub-subcellular locations is to grasp the core features of a protein that can discriminate among proteins with different subcompartment locations. In this study, a different formulation of pseudoamino acid composition by the approach of discrete wavelet transform

Shao-Ping Shi; Jian-Ding Qiu; Xing-Yu Sun; Jian-Hua Huang; Shu-Yun Huang; Sheng-Bao Suo; Ru-Ping Liang; Li Zhang

2011-01-01

60

Transformation of oil-producing fungus, Mortierella alpina 1S-4, using Zeocin, and application to arachidonic acid production.  

PubMed

The arachidonic acid-producing fungus Mortierella alpina 1S-4, an industrial strain, was endowed with Zeocin resistance by integration of the Zeocin-resistance gene at the rDNA locus of genomic DNA. Plasmid DNA was introduced into spores by microprojectile bombardment. Twenty mg/ml Zeocin completely inhibited the germination of M. alpina 1S-4 spores, and decreased the growth rate of fungal filaments to some extent. It was suggested that preincubation period and temperature had a great influence on transformation efficiency. Four out of 26 isolated transformants were selected. Molecular analysis of these stable transformants showed that the plasmid DNA was integrated into the rDNA locus of the genomic DNA. We expect that this system will be applied for useful oil production by gene manipulation of M. alpina 1S-4 and its derivative mutants. On the basis of the fundamental transformation system, we also tried to overexpress a homologous polyunsaturated fatty acid elongase gene, which has been reported to be included in the rate-limiting step for arachidonic acid production, thereby leading to increased arachidonic acid production. PMID:16473770

Takeno, Seiki; Sakuradani, Eiji; Tomi, Akiko; Inohara-Ochiai, Misa; Kawashima, Hiroshi; Shimizu, Sakayu

2005-12-01

61

Process Coupling Between Mineral Transformation and U Speciation in Acid Waste Weathered Sediments  

NASA Astrophysics Data System (ADS)

The need for better prediction of contaminant transport motivates multi-faceted lines of inquiry to build a strong bridge between molecular- and field-scale information. At Hanford (WA), millions of liters of U-containing acidic wastes have been discharged to the soil. In order to predict reactive contaminant migration in the soil, it is necessary to determine the process coupling that occurs between mineral transformation and uranium speciation in these acid-uranium waste weathered sediments. Furthermore, we seek to establish linkages between molecular-scale contaminant speciation and meso-scale contaminant lability, release and reactive transport. Unweathered Hanford sediments were reacted for 365 days with acidic (pH 3), uranium bearing waste solutions in batch experiments. The presence and absence of phosphate in the waste as a control on uranium speciation was also investigated. At dedicated reaction times (7, 14, 30, 90, 180 and 365 days) solid and solution chemistry were analyzed to determine weathering trajectories and contaminant speciation. As observed by XRD and U-EXAFS, when present, PO4 exerted a strong controls over uranium speciation at all pH with the rapid precipitation of meta-ankoleite [K(UO2PO4).3H2O] and near complete immobilization of U. Over prolonged reaction time, however, small fractions of boltwoodite [K(UO2)(HSiO4).3H2O] increased in PO4-high U systems. When PO4 was excluded from the reaction systems, U speciation was indirectly controlled by the pH of the reactant solution and its effect on primary mineral weathering. In this case, U immobilization remained limited with 25 to 50% of the uranium precipitated as becquerelite ([Ca(UO2)6O4(OH)6.3H2O] or the K equivalent - compreignacite) and suspected boltwoodite. Differences between the systems are attributed to process coupling between acid chemistry and U geochemistry. Carbonate weathering contributed to rapidly buffer the pH to pH 7-8 in the absence of PO4 and to 6-7 in its presence, promoting subsequent silicate weathering that makes aqueous Si available for boltwoodite precipitation. Comparison with homogeneous nucleation experiments and thermodynamic calculations confirmed the strong phosphate control over U speciation and the multispeciation of U in its absence.

Perdrial, N.; Kanematsu, M.; Wang, G.; Um, W.; O'Day, P. A.; Chorover, J.

2013-12-01

62

Main fatty acid classes in vegetable oils by SB-ATR-Fourier transform infrared (FTIR) spectroscopy.  

PubMed

The prospect of using single bounce attenuated total reflectance (SB-ATR)-Fourier transform infrared (FTIR) spectroscopy as a rapid quantitative tool to determine the main fatty acid groups present in different edible oils was investigated. Partial least squares (PLS) calibrations were developed using SB-ATR-FTIR spectra which were associated with fatty acid groups (saturated, trans, mono- and polyunsaturated) using quantitative data obtained by gas chromatography (GC). Good calibrations were obtained for all main four fat groups (saturated, mono, trans and polyunsaturated) with excellent precision. The coefficient of determination (R(2)), root mean square error of prediction (RMSEP) and bias for validation set were obtained as 0.999, 2.43 and 0.998 for saturated; 0.999, 1.850 and 0.003 for mono; 0.999, 0.625 and -0.001 for trans while for poly the values were 0.999, 1.170 and 0.003, respectively. The results of 13 validation samples for total saturated, mono, trans and polyunsaturated fats by FI-IR were found in the range of 8.16-55.16, 37.62-74.75, 0.20-18.16 and 1.36-62.35%, respectively. The present study shows that it may well be possible to expand the utility of SB-ATR-FTIR spectroscopy not only to provide isolated trans data, but also serve as a simple, rapid and quantitative means of categorizing the main groups present in the edible oils. The information obtained would be useful for meeting the new lipid nutritional labeling requirements. PMID:19836526

Sherazi, S T H; Talpur, M Younis; Mahesar, S A; Kandhro, Aftab A; Arain, Sarfraz

2009-12-15

63

Chemistry of fog waters in California's Central Valley: 2. Photochemical transformations of amino acids and alkyl amines  

NASA Astrophysics Data System (ADS)

Although amino compounds are seemingly ubiquitous in atmospheric particles and deposition, little is known of their fate in the troposphere. We report here on the fate of 21 amino acids and alkyl amines in fog waters from Davis, California, illuminated with simulated sunlight or monochromatic light. In all experiments four amino acids - histidine (His), methionine (Met), tryptophan (Trp), and tyrosine (Tyr) - consistently decayed, with half-lives that ranged from ˜1 h (Met) to ˜23 h (Tyr) in midday, winter-solstice sunlight at Davis, CA ( solar zenith angle =62°) . Half-lives for the remaining amino compounds examined were typically >45 h in our experiments. Reactions with photoformed hydroxyl radical ( ·OH) and singlet molecular oxygen (O 2( 1? g) or 1O2?) accounted for essentially all of the loss of His and Tyr, the less reactive of the four amino acids that consistently decayed, but were minor sinks for the more reactive compounds (Met and Trp). Additional experiments revealed that methionine sulfoxide (MetSO) was formed with a yield of 58-88% during the oxidation of methionine, suggesting that the ratio of MetSO to Met might be a useful chemical marker for the age of atmospheric particles and drops. Other products expected from the transformation of amino compounds include ammonia, organic acids, and possibly mutagenic nitrosoaromatics. To complement our laboratory experiments, we also calculated rates of transformations of amino acids in near-neutral pH fog drops under ambient conditions. These calculations reveal that ozone should be a major sink for amino acids and that half-lives for many amino acids in ambient fog drops will be much shorter than those determined in our photochemistry experiments. Overall, our results indicate that reactions in atmospheric condensed phases will transform amino nitrogen compounds (including free amino acids as well as proteins and peptides) and, consequently, increase the bioavailability of nitrogen in atmospheric deposition.

McGregor, Keith G.; Anastasio, Cort

64

Alpha lipoic acid selectively inhibits proliferation and adhesion to fibronectin of v-H-ras-transformed 3Y1 cells.  

PubMed

Here, we focused on the effects of racemic ?-lipoic acid on proliferation and adhesion properties of 3Y1 rat fibroblasts and the v-H-ras-transformed derivative, HR-3Y1-2 cells. Racemic ?-lipoic acid inhibited proliferation of HR-3Y1-2 but not 3Y1 cells at 0.3 and 1.0 mM. R-(+)-?-lipoic acid also inhibited proliferation of HR-3Y1-2 cells equivalent to that of racemic ?-lipoic acid. In addition, racemic ?-lipoic acid decreased intracellular reactive oxygen species levels in HR-3Y1 cells but not 3Y1 cells. Next, we evaluated the effects of racemic ?-lipoic acid on cell adhesion to fibronectin. The results indicated that racemic ?-lipoic acid decreased adhesive ability of HR-3Y1-2 cells to fibronectin-coated plates. As blocking antibody experiment revealed that ?1-integrin plays a key role in cell adhesion in this experimental system, the effects of racemic ?-lipoic acid on the expression of ?1-integrin were examined. The results indicated that racemic ?-lipoic acid selectively downregulated the expression of cell surface ?1-integrin expression in HR-3Y1-2 cells. Intriguingly, exogenous hydrogen peroxide upregulated cell surface ?1-integrin expression in 3Y1 cells. Taken together, these data suggest that reduction of intracellular reactive oxygen species levels by ?-lipoic acid could be an effective means of ameliorating abnormal growth and adhesive properties in v-H-ras transformed cells. PMID:22573927

Yamasaki, Masao; Iwase, Masahiro; Kawano, Kazuo; Sakakibara, Yoichi; Suiko, Masahito; Nishiyama, Kazuo

2012-05-01

65

Polarization-modulated Fourier transform infrared spectroscopy of a polylactic acid film.  

E-print Network

??Fourier-Transform Infrarotspektroskopie (FTIR) ist ein etabliertes Messverfahren in der industriellen Prozessanalyse, bei der derzeit noch weitestgehend auf die Messung der Änderung der Polarisation des Lichtes,… (more)

Kilgus, Jakob

2013-01-01

66

Specific amino acid substitutions are not required for transformation by v-myb of avian myeloblastosis virus.  

PubMed Central

The protein product of the v-myb oncogene of avian myeloblastosis virus, p48v-myb, differs structurally in several ways from its normal cellular homolog, p75c-myb. We demonstrated that the 11 specific amino acid substitutions found in two independent molecular clones of this virus were not required for the transformation of myeloblasts by v-myb. Images PMID:2828660

Stober-Grasser, U; Lipsick, J S

1988-01-01

67

Homogeneous catalysis by heteropoly acids: A redox transformation of H 4[SiMo 12O 40] in electrophilic reactions  

Microsoft Academic Search

The transformation of the silico-molybdic acid (H4[SiMo12O40]) used as catalyst in the dehydration of 1,4-butanediol was studied by IR, UV-VIS and ESR spectroscopies. During the reaction, the color of the catalyst changed gradually with the concomitant appearance of a broad new doublet in the 600–900 nm region in the electron spectra. At the beginning, ESR data indicate valence-state change of

Béla Török; Árpád Molnár; Nándor Balogh; Imre Kiricsi; István Pálinkó; László I. Horváth

1997-01-01

68

Deoxyribonucleic acid-mediated gene transfer in mammalian cells: Molecular analysis of unstable transformants and their progression to stability  

SciTech Connect

To elucidate mechanisms involved in deoxyribonucleic acid-mediated gene transfer, we transferred the herpes simplex virus thymidine kinase gene (TK) into mouse Ltk/sup -/ cells. Independent TK/sup +/ clones (transformants) and derivatives of each were tested for phenotypic expression and the presence and arrangement of TK sequences. Initially, transformants expressed viral TK unstably, with 10% of the cells in each generation losing both the TK/sup +/ phenotype and virally derived TK sequences. After a prolonged period in culture, stable subpopulations arose from which the TK/sup +/ phenotype and viral sequence were no longer lost at detectable frequency. Analysis of unstable cell populations indicated that individual viral deoxyribonucleic acid molecules were reduced in size, but were linked to other deoxyribonucleic acid to form molecules large enough to be precipitated in a Hirt fractionation. The authors term these molecules transgenomes. Analysis of independent unstable subclones derived from the primary transformants demonstrated that individual transgenomes could contain multiple copies of the viral TK sequences. Recipient cell lines frequently possesses more than one type of the transgenome and possibly multiple copies per cell of each type. Stable derivatives possesses only one of the transgenomes present in the unstable parent, and these sequences were associated with a recipient cell chromosome.

Scangos, G.A.; Huttner, K.M.; Juricek, D.K.; Ruddle, F.H.

1981-02-01

69

State of the art of Lewis acid-containing zeolites: lessons from fine chemistry to new biomass transformation processes.  

PubMed

The former synthesis of TS-1 opened new catalytic opportunities for zeolites, especially for their application as selective redox catalysts in several fine chemistry processes. Interestingly, isolated Ti species in the framework positions of hydrophobic zeolites, such as high silica zeolites, offer unique Lewis acid sites even in the presence of protic polar solvents (such as water). Following this discovery, other transition metals (such as Sn, Zr, V, Nb, among others) have been introduced in the framework positions of different hydrophobic zeolitic structures, allowing their application in new fine chemistry processes as very active and selective redox catalysts. Recently, these hydrophobic metallozeolites have been successfully applied as efficient catalysts for several biomass-transformation processes in bulk water. The acquired knowledge from the former catalytic descriptions in fine chemistry processes using hydrophobic Lewis acid-containing zeolites has been essential for their application in these novel biomass transformations. In the present review, I will describe the recent advances in the synthesis of new transition metal-containing zeolites presenting Lewis acid character, and their unique catalytic applications in both fine chemistry and novel biomass-transformations. PMID:24142026

Moliner, Manuel

2014-03-21

70

An empirical model of amino acid transformations in an alpine soil D.A. Lipson*, T.K. Raab, S.K. Schmidt, R.K. Monson  

E-print Network

ecosystems. This study estimates seasonal amino acid ¯uxes in an alpine tundra soil using three independent Science Ltd. All rights reserved. Keywords: Alpine tundra; Amino acids; Microbial degradation; NitrogenAn empirical model of amino acid transformations in an alpine soil D.A. Lipson*, T.K. Raab, S

Schmidt, Steven K.

71

Metformin and phenformin deplete tricarboxylic acid cycle and glycolytic intermediates during cell transformation and NTPs in cancer stem cells.  

PubMed

Metformin, a first-line diabetes drug linked to cancer prevention in retrospective clinical analyses, inhibits cellular transformation and selectively kills breast cancer stem cells (CSCs). Although a few metabolic effects of metformin and the related biguanide phenformin have been investigated in established cancer cell lines, the global metabolic impact of biguanides during the process of neoplastic transformation and in CSCs is unknown. Here, we use LC/MS/MS metabolomics (>200 metabolites) to assess metabolic changes induced by metformin and phenformin in an Src-inducible model of cellular transformation and in mammosphere-derived breast CSCs. Although phenformin is the more potent biguanide in both systems, the metabolic profiles of these drugs are remarkably similar, although not identical. During the process of cellular transformation, biguanide treatment prevents the boost in glycolytic intermediates at a specific stage of the pathway and coordinately decreases tricarboxylic acid (TCA) cycle intermediates. In contrast, in breast CSCs, biguanides have a modest effect on glycolytic and TCA cycle intermediates, but they strongly deplete nucleotide triphosphates and may impede nucleotide synthesis. These metabolic profiles are consistent with the idea that biguanides inhibit mitochondrial complex 1, but they indicate that their metabolic effects differ depending on the stage of cellular transformation. PMID:25002509

Janzer, Andreas; German, Natalie J; Gonzalez-Herrera, Karina N; Asara, John M; Haigis, Marcia C; Struhl, Kevin

2014-07-22

72

Amino acid-dependent transformations of citrate-coated silver nanoparticles: impact on morphology, stability and toxicity.  

PubMed

Humans face the risk of exposure to silver nanoparticles (AgNPs) due to their extensive application in consumer products. AgNPs can interact with many substances in the human body due to their chemically unstable nature and high activity properties, which might result in unknown hazards and even some serious diseases for humans. As the basic constituent element of human bodies, amino acids (AAs) differ in concentration and variety in different cells and tissues. Thus, understanding the transformation of citrate-coated AgNPs in the presence of AAs is crucial for determining their fate and toxicity in the human body. Our study focused on the transformation of the morphology, dissolution behavior and reaction product of AgNPs in different AA-containing systems and then evaluated the effect of these transformations on the cytotoxicity of AgNPs. The obtained results indicated that the addition of glycine with the lowest Ag(+) binding energy had little effect on the transformations and toxicity of AgNPs. While in the presence of histidine with higher Ag(+) binding energy, the Ag(+) release and particle size of AgNPs obviously increased. These transformations resulted in a decrease in the cytotoxicity of AgNPs due to the formation of Ag-His complex and the growth of AgNPs. Furthermore, l-cysteine with the highest Ag(+) binding energy could easily interact with AgNPs, transforming them completely to form [Ag(Cys)n](+) and Ag2S precipitates, which induced the largest decrease in AgNP toxicity. In summary, our results may provide useful information to understand the fate, transformation, and toxicity of citrate-coated AgNPs in the human body. PMID:24910988

Shi, Junpeng; Sun, Xia; Zou, Xiaoyan; Zhang, Hongwu

2014-08-17

73

Restriction of patching of bound concanavalin A after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts  

PubMed Central

Topographical distribution of concanavalin A binding sites (CABS) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. Fatty acid composition was manipulated by incubating cells in fatty acid, ATP, CoA, and delipidated fetal calf serum (FCS). VLM cells grown in medium containing 5% FCS have a clustered CABS distribution. Plasma membrane vesicles (PMVs) derived from these cells have an arachidonate content of 1.7%. Elevation of PMV arachidonate to 15.8% results in a marked restriction of CABS patching, while elevation to 6.8% is associated with intermediate restriction of patching. Restriction of patching is associated with increased microviscosity. CABS of Rous sarcoma virus-transformed chicken embryo fibroblasts (RSV-CEF) are also responsive to arachidonate enrichment medium. Whereas untreated cells have a clustered CABS distribution, cells incubated for 24 h in arachidonate enrichment medium have predominantly a dispersed CABS distribution. In both VLM cells and RSV- CEF, ATP, CoA, and delipidated FCS alone have no effect upon CABS mobility. Inhibition of CABS patching is also observed when aspirin is included in the arachidonate enrichment medium but not when the cells are incubated in prostaglandins, thus suggesting that the restriction of CABS mobility is not mediated by prostaglandins. Other fatty acids (palmitate, oleate, nonadecanoate) failed to restrict CABS movement. The inhibition of CABS mobility is independent of cell shape change. PMID:229111

1979-01-01

74

Metabolism of fatty acids and lipid hydroperoxides in human body monitoring with Fourier transform Infrared Spectroscopy  

Microsoft Academic Search

BACKGROUND: The metabolism of dietary fatty acids in human has been measured so far using human blood cells and stable-isotope labeled fatty acids, however, no direct data was available for human peripheral tissues and other major organs. To realize the role of dietary fatty acids in human health and diseases, it would be eager to develop convenient and suitable method

Satoshi Yoshida; Qin-Zeng Zhang; Shu Sakuyama; Satoshi Matsushima

2009-01-01

75

Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues.  

PubMed

Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and compositions of the oxidation products differed according to the oxidizing agent used. Main products of oxidation by 30% HNO(3) were acetic, glucaric, oxalic and glycolic acids. Applying H(2)O(2)/CuO in alkaline solution, the organic acid yields were remarkably lower with formic, acetic and threonic acids as main products. Gluconic acid was formed instead of glucaric acid throughout. Reaction of a 10% H(2)O(2) solution with sugar beet molasses generated formic and lactic acids mainly. Na(2)S(2)O(8) solutions were very inefficient at oxidizing the residues. Glucose, arabinose and galactose were formed during acidic hydrolysis of malt dust and apple marc. The glucose content reached 0.35 g per gram of residue. Important advantages of the microwave application were lower reaction times and reduced reagent demands. PMID:15607197

Fischer, Klaus; Bipp, Hans-Peter

2005-05-01

76

Rapid characterization and identification of fatty acids in margarines using horizontal attenuate total reflectance Fourier transform infrared spectroscopy (HATR-FTIR)  

Microsoft Academic Search

Fourier transform infrared spectroscopy (FTIR) with horizontal attenuated total reflectance (HATR) coupled to multivariate\\u000a analysis was used to predict chemical composition, fatty acid profile, nutritional relationships between fatty acids, and\\u000a to identify trans fatty acids (TFA) of margarines. For model building and validation, a set of 42 margarines samples were\\u000a analyzed in terms of fatty acid profile, total fat, moisture,

Maylet Hernández-Martínez; Tzayhri Gallardo-Velázquez; Guillermo Osorio-Revilla

2010-01-01

77

Thermal transformation of trans-5-O-caffeoylquinic acid (trans-5-CQA) in alcoholic solutions.  

PubMed

Chlorogenic acid (CQA), the ester of caffeic acid with quinic acid supplied to human organisms mainly with coffee, tea, fruit and vegetables, has been one of the most studied polyphenols. It is potentially useful in pharmaceuticals, food additives, and cosmetics due to its recently discovered biomedical activity, which revived interest in its properties, isomers and natural occurrence. We found that the heating of the alcoholic solution of trans-5-O-caffeoylquinic acid produced at least twenty compounds (chlorogenic acid derivatives and its reaction products with water and alcohol). The formation of three of them (methoxy, ethoxy and propoxy adducts) has not been reported yet. No reports exist either on methoxy adducts of 3- and 4-O-caffeoylquinic acid appearing in buffered methanol/water mixtures at pH exceeding 7. We observed that the amount of each formed component depended on the heating time, type of alcohol, its concentration in alcoholic/water mixture, and pH. PMID:25148959

Dawidowicz, Andrzej L; Typek, Rafal

2015-01-15

78

Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues  

Microsoft Academic Search

Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-\\/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and

Klaus Fischer; Hans-Peter Bipp

2005-01-01

79

Effect of Humic Acid on As Redox Transformation and Kinetic Adsorption onto Iron Oxide Based Adsorbent (IBA)  

PubMed Central

Due to the importance of adsorption kinetics and redox transformation of arsenic (As) during the adsorption process, the present study elucidated natural organic matter (NOM) effects on As adsorption-desorption kinetics and speciation transformation. The experimental procedures were conducted by examining interactions of arsenate and arsenite with different concentrations of humic acid (HA) as a model representative of NOM, in the presence of iron oxide based adsorbent (IBA), as a model solid surface in three environmentally relevant conditions, including the simultaneous adsorption of both As and HA onto IBA, HA adsorption onto As-presorbed IBA, and As adsorption onto HA-presorbed IBA. Experimental adsorption-desorption data were all fitted by original and modified Lagergren pseudo-first and -second order adsorption kinetic models, respectively. Weber’s intraparticle diffusion was also used to gain insight into the mechanisms and rate controlling steps, which the results suggested that intraparticle diffusion of As species onto IBA is the main rate-controlling step. Different concentrations of HA mediated the redox transformation of As species, with a higher oxidation ability than reduction. The overall results indicated the significant effect of organic matter on the adsorption kinetics and redox transformation of As species, and consequently, the fate, transport and mobility of As in different environmentally relevant conditions. PMID:25325357

Fakour, Hoda; Lin, Tsair-Fuh

2014-01-01

80

Effect of humic acid on as redox transformation and kinetic adsorption onto iron oxide based adsorbent (IBA).  

PubMed

Due to the importance of adsorption kinetics and redox transformation of arsenic (As) during the adsorption process, the present study elucidated natural organic matter (NOM) effects on As adsorption-desorption kinetics and speciation transformation. The experimental procedures were conducted by examining interactions of arsenate and arsenite with different concentrations of humic acid (HA) as a model representative of NOM, in the presence of iron oxide based adsorbent (IBA), as a model solid surface in three environmentally relevant conditions, including the simultaneous adsorption of both As and HA onto IBA, HA adsorption onto As-presorbed IBA, and As adsorption onto HA-presorbed IBA. Experimental adsorption-desorption data were all fitted by original and modified Lagergren pseudo-first and -second order adsorption kinetic models, respectively. Weber's intraparticle diffusion was also used to gain insight into the mechanisms and rate controlling steps, which the results suggested that intraparticle diffusion of As species onto IBA is the main rate-controlling step. Different concentrations of HA mediated the redox transformation of As species, with a higher oxidation ability than reduction. The overall results indicated the significant effect of organic matter on the adsorption kinetics and redox transformation of As species, and consequently, the fate, transport and mobility of As in different environmentally relevant conditions. PMID:25325357

Fakour, Hoda; Lin, Tsair-Fuh

2014-01-01

81

Establishment of Agrobacterium tumefaciens-Mediated Transformation of an Oleaginous Fungus, Mortierella alpina 1S-4, and Its Application for Eicosapentaenoic Acid Producer Breeding?  

PubMed Central

Gene manipulation tools for an arachidonic-producing filamentous fungus, Mortierella alpina 1S-4, have not been sufficiently developed. In this study, Agrobacterium tumefaciens-mediated transformation (ATMT) was investigated for M. alpina 1S-4 transformation, using the uracil-auxotrophic mutant (ura5? strain) of M. alpina 1S-4 as a host strain and the homologous ura5 gene as a selectable marker gene. Furthermore, the gene for ?3-desaturase, catalyzing the conversion of n-6 fatty acid to n-3 fatty acid, was overexpressed in M. alpina 1S-4 by employing the ATMT system. As a result, we revealed that the frequency of transformation surpassed 400 transformants/108 spores, most of the integrated T-DNA appeared as a single copy at a random position in chromosomal DNA, and most of the transformants (60 to 80%) showed mitotic stability. Moreover, the accumulation of n-3 fatty acid in transformants was observed under the conditions of optimal ?3-desaturase gene expression. In particular, eicosapentaenoic acid (20:5n-3), an end product of n-3 fatty acids synthesized in M. alpina 1S-4, reached a maximum of 40% of total fatty acids. In conclusion, the ATMT system was found to be effective and suitable for the industrial strain Mortierella alpina 1S-4 and will be a useful tool for basic mutagenesis research and for industrial breeding of this strain. PMID:19581481

Ando, Akinori; Sumida, Yosuke; Negoro, Hiroaki; Suroto, Dian Anggraini; Ogawa, Jun; Sakuradani, Eiji; Shimizu, Sakayu

2009-01-01

82

Establishment of Agrobacterium tumefaciens-mediated transformation of an oleaginous fungus, Mortierella alpina 1S-4, and its application for eicosapentaenoic acid producer breeding.  

PubMed

Gene manipulation tools for an arachidonic-producing filamentous fungus, Mortierella alpina 1S-4, have not been sufficiently developed. In this study, Agrobacterium tumefaciens-mediated transformation (ATMT) was investigated for M. alpina 1S-4 transformation, using the uracil-auxotrophic mutant (ura5(-) strain) of M. alpina 1S-4 as a host strain and the homologous ura5 gene as a selectable marker gene. Furthermore, the gene for omega3-desaturase, catalyzing the conversion of n-6 fatty acid to n-3 fatty acid, was overexpressed in M. alpina 1S-4 by employing the ATMT system. As a result, we revealed that the frequency of transformation surpassed 400 transformants/10(8) spores, most of the integrated T-DNA appeared as a single copy at a random position in chromosomal DNA, and most of the transformants (60 to 80%) showed mitotic stability. Moreover, the accumulation of n-3 fatty acid in transformants was observed under the conditions of optimal omega3-desaturase gene expression. In particular, eicosapentaenoic acid (20:5n-3), an end product of n-3 fatty acids synthesized in M. alpina 1S-4, reached a maximum of 40% of total fatty acids. In conclusion, the ATMT system was found to be effective and suitable for the industrial strain Mortierella alpina 1S-4 and will be a useful tool for basic mutagenesis research and for industrial breeding of this strain. PMID:19581481

Ando, Akinori; Sumida, Yosuke; Negoro, Hiroaki; Suroto, Dian Anggraini; Ogawa, Jun; Sakuradani, Eiji; Shimizu, Sakayu

2009-09-01

83

Absence de transformation bactrienne des acides biliaires chez la truite arc-en-ciel, Saimo gairdneri,  

E-print Network

gairdneri, raised at 16 °c. The fecal bile acids of the rainbow trout, Salmo gairdneri, raised at 16 o gairdneri, élevée à 16°C E. SACQUET R. LESEL C. MEJEAN M. RIOTTOT C. LEPRINCE Laboratoire des Animaux sans Nivelle, 64310 Ascain. Summary. Absence of bacterial conversion of bile acids in the rainbow trout, Salmo

Paris-Sud XI, Université de

84

Telomerase inhibition by peptide nucleic acids reverses `immortality' of transformed human cells  

Microsoft Academic Search

Telomerase activity, the ability to add telomeric repeats to the ends of chromosomes, has been detected in most immortal cell lines including tumor cells, but is low or absent in most diploid, mortal cells such as those of somatic tissues. Peptide nucleic acids (PNAs), analogs of DNA or RNA which bind to complementary nucleic acids with very high affinity, were

Masood A Shammas; Carla G Simmons; David R Corey; Robert J Shmookler Reis; RJS Reis

1999-01-01

85

Linking photochemical transformation of an Antarctica Fulvic Acid to diminished bioavailability and oxidation of organic electron shuttles  

NASA Astrophysics Data System (ADS)

Photolysis of fulvic acid isolated from Pony Lake, Antarctica, a hypereutrophic coastal pond located on Ross Island, was evaluated for transformation kinetics and photo-bleaching mechanisms by spectroscopy, as well as changes in bioavailability. The fulvic acid fraction of Pony Lake was isolated by sorption to non-ionic XAD-8 resin, and represents the fraction of the dissolved organic matter considered to be the most photo-reactive fraction. Spectroscopic and electrochemical analysis during Pony Lake fulvic acid photolysis reveals three fundamental alterations to the natural organic matter isolate: decreased molar absorptivity, decreased fluorescence, and a loss of reduced organic functional groups (potential electron shuttles). Surprisingly we observed no carbon loss to mineralization. Evaluation of the light absorbance decay kinetics in the presence/absence of oxygen indicate that approximately 70% of photo-bleaching occurs via direct pathways and 30% is due to reaction with photochemically generated reactive oxygen species (ROS). Of the ROS mediated pathways approximately 70% of the reactivity is attributable to hydroxyl-radical oxidation. Molecular level changes in fulvic acid showed a loss of electron-rich (reduced) components during photolysis, specifically redox active N/S functional groups. Reduced forms of organic nitrogen (amines) decrease in concentration, while sulfur moieties (thiols) are essentially eliminated during photolysis. Furthermore, as the suite of reduced fulvic acid components are photochemically oxidized, we observe a concomitant production of hydrogen peroxide, presumably due to the photo-reduction of dissolved oxygen coupled to organic matter oxidation. Decay kinetics of fluorescent components identified in the fulvic acid isolate were evaluated using parallel factor component analysis (PARAFAC) of excitation-emission matrices (EEMs), and further illustrate a loss of overall fluorescence and a decrease in the redox-active (electron- shuttling) components of the fulvic acid. These molecular-scale changes in photo-chemically altered fulvic acid illustrate a general trend towards broad-scale oxidation of chromophores, fluorophores, and reduced organic N/S functionalities. The loss of electron-donating capacity was correlated to decreases in relative concentrations of redox-active moieties in microbially-derived fulvic acid and suggests that photolysis attacks the electron shuttling properties of the fulvic acid. Photochemical oxidation of electron-rich functional groups and chemical degradation of organic electron shuttles may be related to the decreased bioavailability of photolyzed fulvic acid.

Fimmen, R. L.; Guerard, J. J.; Miller, P. L.; Cory, R. M.; Chin, Y.; Foreman, C. M.; McKnight, D. M.

2007-12-01

86

Fourier transform infrared studies of model polar stratospheric cloud surfaces - Growth and evaporation of ice and nitric acid/ice  

NASA Technical Reports Server (NTRS)

Fourier-transform infrared surface studies are used to probe the microphysical properties of nitric acid trihydrate (NAT) and ice films representative of type I and II polar stratospheric clouds (PSC). Experiments indicate that, on initial exposure to 1.8 microtorr of HNO3, a layer of ice is quantitatively converted to NAT. However, conversion of ice to NAT does not proceed indefinitely, but rather the system reaches saturation. For longer exposures or higher HNO3 pressures, NAM becomes the dominant nitric acid containing species on the surface. Evaporation studies were performed to test the feasibility of a recent denitrification mechanism. The results indicate that ice coated with 0.20 micron of NAT evaporates at a temperature of about 4 C higher than uncoated ice.

Tolbert, Margaret A.; Middlebrook, Ann M.

1990-01-01

87

Adsorption of Amino Acids (Ala, Cys, His, Met) on Zeolites: Fourier Transform Infrared and Raman Spectroscopy Investigations  

NASA Astrophysics Data System (ADS)

Minerals adsorb more amino acids with charged R-groups than amino acids with uncharged R-groups. Thus, the peptides that form from the condensation of amino acids on the surface of minerals should be composed of amino acid residues that are more charged than uncharged. However, most of the amino acids (74%) in today's proteins have an uncharged R-group. One mechanism with which to solve this paradox is the use of organophilic minerals such as zeolites. Over the range of pH (pH 2.66-4.50) used in these experiments, the R-group of histidine (His) is positively charged and neutral for alanine (Ala), cysteine (Cys), and methionine (Met). In acidic hydrothermal environments, the pH could be even lower than those used in this study. For the pH range studied, the zeolites were negatively charged, and the overall charge of all amino acids was positive. The conditions used here approximate those of prebiotic Earth. The most important finding of this work is that the relative concentrations of each amino acid (X=His, Met, Cys) to alanine (X/Ala) are close to 1.00. This is an important result with regard to prebiotic chemistry because it could be a solution for the paradox stated above. Pore size did not affect the adsorption of Cys and Met on zeolites, and the Si/Al ratio did not affect the adsorption of Cys, His, and Met. ZSM-5 could be used for the purification of Cys from other amino acids (Student-Newman-Keuls test, p<0.05), and mordenite could be used for separation of amino acids from each other (Student-Newman-Keuls test, p<0.05). As shown by Fourier transform infrared (FT-IR) spectra, Ala interacts with zeolites through the group, and methionine-zeolite interactions involve the COO, , and CH3 groups. FT-IR spectra show that the interaction between the zeolites and His is weak. Cys showed higher adsorption on all zeolites; however, the hydrophobic Van der Waals interaction between zeolites and Cys is too weak to produce any structural changes in the Cys groups (amine, carboxylic, sulfhydryl, etc.); thus, the FT-IR and Raman spectra are the same as those of solid Cys.

Carneiro, Cristine E. A.; de Santana, Henrique; Casado, Clara; Coronas, Joaquin; Zaia, Dimas A. M.

2011-06-01

88

Bacterial production and transformation of dissolved neutral sugars and amino acids in seawater  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) in the ocean consists of a heterogeneous mixture of molecules, most of which are of unknown origin. Neutral sugars and amino acids are among the few recognizable biomolecules in DOM, and the molecular composition of these biomolecules is shaped primarily by biological production and degradation processes. This study provides insight into the bioavailability of biomolecules as well as the chemical composition of DOM produced by bacteria. The molecular compositions of neutral sugars and amino acids were investigated in DOM produced by bacteria and in DOM remaining after long-term bacterial degradation. Results from bioassay incubations (32 days) with natural and artificial seawater, indicate that the molecular compositions following bacterial degradation are not strongly influenced by the initial substrate or bacterial community. The molecular composition of neutral sugars released by bacteria was characterized by a high glucose content (47 mol%) and heterogeneous contributions from other neutral sugars (3-14 mol%). DOM remaining after bacterial degradation was characterized by a high galactose content (33 mol%), followed by glucose (22 mol%) and the remaining neutral sugars (7-11 mol%). The ratio of D-amino acids to L-amino acids increased during the experiments as a response to bacterial degradation, and after 32 days the D/L ratios of aspartic acid, glutamic acid, serine and alanine reached around 0.79, 0.32, 0.30 and 0.51 in all treatments, respectively. The striking similarity in neutral sugar and amino acid compositions between natural and artificial seawater samples, suggests that the microbial carbon pump also applies for neutral sugars and amino acids and that bacterially-produced biomolecules persist for long periods in the ocean.

Jørgensen, L.; Lechtenfeld, O.; Benner, R.; Middelboe, M.; Stedmon, C. A.

2014-04-01

89

Transformation of fatty acids catalyzed by cytochrome P450 monooxygenase enzymes of Candida tropicalis  

Microsoft Academic Search

Candida tropicalis ATCC 20336 can grow on fatty acids or alkanes as its sole source of carbon and energy, but strains blocked in -oxidation convert these substrates to long-chain ,-dicarboxylic acids (diacids), compounds of potential commercial value (Picataggio et al., Biotechnology 10:894-898, 1992). The initial step in the formation of these diacids, which is thought to be rate limiting, is

William H. Eschenfeldt; Yeyan Zhang; Hend Samaha; Lucy Stols; L. Dudley Eirich; C. Ronald Wilson; Mark I. Donnelly

2003-01-01

90

Role of Oxalic Acid Overexcretion in Transformations of Toxic Metal Minerals by Beauveria caledonica  

Microsoft Academic Search

Received 9 June 2004\\/Accepted 29 August 2004 The fungus Beauveria caledonica was highly tolerant to toxic metals and solubilized cadmium, copper, lead, and zinc minerals, converting them into oxalates. This fungus was found to overexcrete organic acids with strong metal-chelating properties (oxalic and citric acids), suggesting that a ligand-promoted mechanism was the main mechanism of mineral dissolution. Our data also

M. Fomina; S. Hillier; J. M. Charnock; K. Melville; I. J. Alexander; G. M. Gadd

2005-01-01

91

Structural transformation induced by locked nucleic acid or 2?-O-methyl nucleic acid site-specific modifications on thrombin binding aptamer  

PubMed Central

Background Locked nucleic acid (LNA) and 2'–O-methyl nucleic acid (OMeNA) are two of the most extensively studied nucleotide derivatives in the last decades. However, how they affect DNA quadruplex structures remains largely unknown. To explore their possible biological affinities for quadruplexes, we investigated how LNA- or OMeNA-substitutions affect G-quadruplex structure formation using a thrombin binding aptamer (TBA), the most studied extracorporal G-quadruplex-forming DNA sequence, which is frequently modified to increase its analytical performance. Results The experimental results showed that when two or more nucleotides were substituted with LNA or OMeNA, the anti-parallel TBA structure was transformed into an unstructured random conformation in a 50 mM K+ environment; OMeNA appeared to have greater power to induce this transformation. However, the native TBA was unstructured in a 50 mM Ca2+ environment, whereas four or more LNA- or OMeNA- substitutions could convert this unstructured TBA into a parallel quadruplex structure. PAGE mobility measurements suggested that these TBAs might be a dimeric form. Conclusion LNA or 2'-OMeNA site-specific modifications induced G-quadruplex structural transformation of TBA, which enriched our understanding of the intrinsic G-quadrupex forming property and affinity of LNA and OMeNA modifications. This study demonstrates possible applications in the regulation of gene expression (i.e. manual intervention of gene therapy), genetic analyses, molecular diagnosis and the construction of nano-scale biostructures. PMID:24642032

2014-01-01

92

[Determination of chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near infrared spectroscopy].  

PubMed

The objective of the present study was to investigate the feasibility of predicting chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near-infrared (FT-NIR) spectroscopy. The partial least squares(PLS) regression method, second derivative and Norris derivative filter were applied in the NIR spectroscopy prediction of chlorogenic acid, rutin, scopoletin and total polyphenol in the range of 7 500 to 4 000 cm(-1). For chlorogenic acid, rutin, scopoletin and total polyphenol, the determination coefficients were 0.976 6, 0.941 9, 0.957 1 and 0.966 6, respectively. The SEP/SEC values for them were < 1.2, and the SD/SEP values for them were > 2. The root mean square error of cross validation (RMSECV) of the four calibration models were 1.938 9, 1.046 2, 0.047 9 and 2.745 2, respectively. NIR spectroscopy was compared with the conventional methods. The results show that the two methods showed no significant difference at the significant level of 0.05. NIR spectroscopy technology can accurately analyze chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco. PMID:24059178

Leng, Hong-Qiong; Guo, Ya-Dong; Liu, Wei; Zhang, Tao; Deng, Liang; Shen, Zhi-Qiang

2013-07-01

93

Effect of pH and organic acids on nitrogen transformations and metal dissolution in soils  

SciTech Connect

The effect of pH (4, 6, and 8) on nitrogen mineralization was evaluated in three Iowa surface soils treated with crop residues (corn (Zea mays L.), soybean (Glycine max (L.) Merr.), and sorghum (Sorghum vulgare Pers.), or alfalfa (Medicago sativa L.)) and incubated in leaching columns under aerobic conditions at 30C for 20 weeks. In general, N mineralization was significantly depressed at soil pH 4, compared with pH 6 or 8. The types of crop residues added influenced the pattern and amount of N mineralization. A study on the effect of 19 trace elements on the nitrate red activity of four Iowa surface soils showed that most trace elements inhibited this enzyme in acid and neutral soils. The trace elements Ag(I), Cd(II), Se(IV), As(V), and W(VI) were the most effective inhibitors, with >75% inhibition. Mn(II) was the least effective inhibitor, with <10% inhibition. Other trace elements included Cu(I), Co(II), Cu(II), Fe(II), Ni(II), Pb(II), Zn(II), Al(III), As(III), Cr(III), Fe(III), V(IV), Mo(VI), and Se(VI). The application of high-performance liquid chromatography (HPLC) showed that, when coupled to a refractive index detector, it is a rapid, sensitive, and accurate method for determining organic acids in soils. Three organic acids, acetic (2-20 mM), propionic (0-3 mM), and n-butyric (0-1.4 mM), were identified with HPLC and confirmed by gas chromatography in crop-residue-treated soils incubated under waterlogged conditions at 25C for 72 h. No organic acids were detected under aerobic conditions. Four mineral acids and 29 organic acids were studied for their effect on N mineralization and metal dissolution in soils incubated under waterlogged conditions at 30C for 10 days.

Fu, Minhong.

1989-01-01

94

Synthesis and transformation of (N-substituted 2-methyl-5-methoxy-3-indolyl)succinic acids  

Microsoft Academic Search

The reaction of N-substituted 2-methyl-5-methoxyindoles with maleic anhydride gave the corresponding (2-methyl-5-methoxy-3-indolyl)succinic anhydrides, which were hydrolyzed to acids and converted to monoamides by reaction with primary or secondary amines.

S. G. Agbalyan; G. V. Grigoryan

1972-01-01

95

CHEMICAL TRANSFORMATION MODULES FOR EULERIAN ACID DEPOSITION MODELS. VOLUME 2. THE AQUEOUS-PHASE CHEMISTRY  

EPA Science Inventory

This study focuses on the review and evaluation of mechanistic and kinetic data for aqueous-phase reactions that lead to the production of acidic substances in the environment. The intent of this research is to provide a framework that can be used to develop a state-of-the-art aq...

96

Leaching behavior of heavy metals and transformation of their speciation in polluted soil receiving simulated acid rain.  

PubMed

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

2012-01-01

97

Inhibitory effect of the Agrobacterium rhizogenes rolC gene on rabdosiin and rosmarinic acid production in Eritrichium sericeum and Lithospermum erythrorhizon transformed cell cultures  

Microsoft Academic Search

Rabdosiin and related caffeic acid metabolites have been proposed as active pharmacological agents demonstrating potent anti-HIV and antiallergic activities. We transformed Eritrichium sericeum and Lithospermum erythrorhizon seedlings by the rolC gene, which has been recently described as an activator of plant secondary metabolism. Surprisingly, the rolC-transformed cell cultures of both plants yielded two- to threefold less levels of rabdosiin and

Victor P. Bulgakov; M. V. Veselova; G. K. Tchernoded; K. V. Kiselev; S. A. Fedoreyev; Yu. N. Zhuravlev

2005-01-01

98

No activation of new initiation points for deoxyribonucleic acid replication in BALB/c 3T3 cells transformed by Kirsten sarcoma virus  

SciTech Connect

BALB/c 3T3 cells were transformed by Kirsten sarcoma virus, and five clones were isolated in soft agar. Average replicon sizes of the transformed cell lines were stimated by the method of fiber-autoradiography and found to be the same size as the nontransformed 3T3 cells, analyzed in parallel. The results indicate that, unlike simian virus 40 and Epstein-Barr virus, Kirsten sarcoma virus does not activate new initiation points for cellular deoxyribonucleic acid replication in murine sarcome virus-transformed BALB/c 3T3 cells.

Oppenheim, A.; Horowitz, A.T.

1981-08-01

99

Automated Acid and base number determination of mineral-based lubricants by fourier transform infrared spectroscopy: commercial laboratory evaluation.  

PubMed

The Fluid Life Corporation assessed and implemented Fourier transform infrared spectroscopy (FTIR)-based methods using American Society for Testing and Materials (ASTM)-like stoichiometric reactions for determination of acid and base number for in-service mineral-based oils. The basic protocols, quality control procedures, calibration, validation, and performance of these new quantitative methods are assessed. ASTM correspondence is attained using a mixed-mode calibration, using primary reference standards to anchor the calibration, supplemented by representative sample lubricants analyzed by ASTM procedures. A partial least squares calibration is devised by combining primary acid/base reference standards and representative samples, focusing on the main spectral stoichiometric response with chemometrics assisting in accounting for matrix variability. FTIRAN/BN methodology is precise, accurate, and free of most interference that affects ASTM D664 and D4739 results. Extensive side-by-side operational runs produced normally distributed differences with mean differences close to zero and standard deviations of 0.18 and 0.26 mg KOH/g, respectively. Statistically, the FTIR methods are a direct match to the ASTM methods, with superior performance in terms of analytical throughput, preparation time, and solvent use. FTIRAN/BN analysis is a viable, significant advance for in-service lubricant analysis, providing an economic means of trending samples instead of tedious and expensive conventional ASTMAN/BN procedures. PMID:25271046

Winterfield, Craig; van de Voort, F R

2014-12-01

100

Changes in the acid-base properties of cultivated light-textured soddy-podzolic soils in the course of postagrogenic transformation  

Microsoft Academic Search

The rates of changes in the acid-base properties of the sandy-loamy soddy-podzolic soils of fallow lands abandoned for 5,\\u000a 10, 30, and 63 years were determined. The transformation of the vegetation related to the fallow age has been analyzed. The\\u000a density of the human-induced topsoil compaction was found to be gradually restored. Mathematical models describing the changes\\u000a in the acid-base

A. V. Litvinovich; V. F. Drichko; O. Yu. Pavlova; D. V. Chernov; M. V. Shabanov

2009-01-01

101

Arachidonic acid metabolism in normal and transformed rat tracheal epithelial cells and its possible role in the regulation of cell proliferation.  

PubMed

The objectives of our investigations were to characterize the profile of arachidonic acid metabolites produced by cultured rat tracheal epithelial cells, and to determine whether or not transformation of these cells causes major qualitative or quantitative changes in arachidonic acid metabolism and whether arachidonic acid metabolites play an important role in the regulation of proliferation of rat tracheal cells. Our studies showed that prostaglandin E2 was the only major prostanoid produced by normal and transformed rat tracheal epithelial cells. When stimulated with calcium ionophore A23187, 12-O-tetradecanoylphorbol 13-acetate, arachidonic acid, or serum, the cultures produced small amounts of thromboxane B2, prostaglandin F2 alpha, and hydroxyeicosatetraenoic acid(s) in addition to prostaglandin E2. Mitogenesis studies showed that none of the peptide growth factors tested stimulated either prostaglandin E2 production or DNA synthesis. Fetal bovine serum, on the other hand, stimulated both. 12-O-Tetradecanoylphorbol 13-acetate and arachidonic acid stimulated prostaglandin E2 production but caused no increase in DNA synthesis. Dexamethasone and indomethacin, inhibitors of phospholipase A2 and cyclooxygenase, respectively, significantly inhibited prostaglandin E2 production at concentrations as low as 10(-8) and 10(-9) M but did not inhibit DNA synthesis. It is concluded (1) that prostaglandin E2 is the major arachidonic acid metabolite of rat tracheal epithelial cells, (2) that transformation does not significantly alter arachidonic acid metabolism in these cells, and (3) that neither prostaglandin E2 nor other arachidonic acid metabolites play a significant role in mitogenic stimulation of rat tracheal epithelial cells. PMID:2501081

Duniec, Z M; Eling, T E; Jetten, A M; Gray, T E; Nettesheim, P

1989-05-01

102

Single-stranded regions in transforming deoxyribonucleic acid after uptake by competent Haemophilus influenzae.  

PubMed

About 15% of donor deoxyribonucleic acid (DNA) is single stranded immediately after uptake into competent Haemophilus influenzae wild-type cells, as judged by its sensitivity to S1 endonuclease. This amount decreases to 4 to 5% by 30 min after uptake. Mutants which are defective in the covalent association of recipient and donor DNA form little or no S1 endonuclease-sensitive donor. At 17 C donor DNA taken up by the wild type contains single-stranded regions although there is no observable association, either covalent or noncovalent. The single-stranded regions are at the ends of donor DNA molecules, as judged by the unchanged sedimentation velocity after S1 endonuclease digestion. The amount of single-stranded donor remains constant at 17 C for more than 60 min after uptake, suggesting that the decrease observed at 37 C is the result of association of single-stranded ends with single-stranded regions of recipient cell DNA. Three sequential steps necessary for the integration of donor DNA into recipient DNA are proposed: the synthesis of single-stranded regions in recipient DNA, the interaction of donor DNA with recipient DNA resulting in the production of single-stranded ends on donor DNA, and the stable pairing of homologous single-stranded regions. PMID:1081987

Sedgwick, B; Setlow, J K

1976-02-01

103

Phase transformations in sulfuric acid aerosols: Implications for stratospheric ozone depletion  

SciTech Connect

Activation reactions of benign chlorine species (HCl, CIONO{sub 2}) on aerosols in the winter polar stratosphere set the stage for the spring-time catalytic destruction of ozone leading to the Antarctic ozone hole. Field observations have demonstrated the existence of both solid and liquid particles consisting of H{sub 2}SO{sub 4}, HNO{sub 3}, and H{sub 2}O. The exact freezing conditions and final composition of the solid aerosols remain the subject of investigations. We present laboratory observations of isolated individual sulfuric acid/water particles under stratospheric temperatures and water vapor pressures. Our experiments demonstrate that this binary system would not freeze unless temperatures were below the water-ice frost point. Upon freezing, we observe H{sub 2}SO{sub 4}{minus}8H{sub 2}O, not the generally invoked H{sub 2}SO{sub 4}{minus}4H{sub 2}O. We suggest that the water-rich octahydrate phase is likely to be one of the high relative humidity forms which is efficient in chlorine activation.{copyright} 1997 American Geophysical Union

Imre, D.G. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)] [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States); Xu, J. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)] [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States); [Institute of Terrestrial and Planetary Atmospheres, State University of , New York 11794 (United States); Tridico, A.C. [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)] [Environmental Chemistry Division, Department of Applied Science, Brookhaven National Laboratory, Upton, New York (United States)

1997-01-01

104

Unprecedented in situ oxidative ring cleavage of isoxazolidines: diastereoselective transformation of nitronic acids and derivatives into 3-hydroxymethyl 4-nitro tetrahydrofurans and pyrrolidines.  

PubMed

[reaction: see text] Nitronic acids undergo an intramolecular 1,3-dipolar cycloaddition to unactivated double bonds, and the resulting isoxazolidines spontaneously evolve by an unprecedented in situ oxidative ring cleavage. The extension of this transformation to silyl nitronates results in a general diastereoselective construction of hydroxymethyl nitro functionalized tetrahydro-furans and -pyrrolidine having up to four consecutive stereogenic centers. PMID:15176810

Roger, Pierre-Yves; Durand, Anne-Catherine; Rodriguez, Jean; Dulcère, Jean-Pierre

2004-06-10

105

Detailed compositional comparison of acidic NSO compounds in biodegraded reservoir and surface crude oils by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry  

Microsoft Academic Search

Traditional hydrocarbon biomarker analyses determined the degree of biodegradation in two reservoir and two surface oils. These data were then correlated to the distribution and type (rings plus double bonds) of acidic NSO species selectively ionized and mass resolved by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to determine if oxygenated polars could be

Christine A. Hughey; Samantha A. Galasso; John E. Zumberge

2007-01-01

106

Generation and function of immunosuppressive human and murine CD8+ T cells by transforming growth factor-? and retinoic acid.  

PubMed

The intestinal immune system is constantly challenged by foreign antigens and commensal bacteria. Therefore, proper control of the intestinal microenvironment is required. One important arm of this regulatory network consists of regulatory T cells. In contrast to CD4(+) Foxp3(+) regulatory T cells, which have been well characterized, immunomodulatory CD8(+) T cells that express Foxp3 are less well defined in terms of their generation and function. Failures of these regulatory mechanisms contribute to the development of inflammatory bowel disease. In this study we demonstrate that the frequency of CD8(+) Foxp3(+) T cells is reduced in the peripheral blood of patients with ulcerative colitis. As these cells might play a currently underestimated role in the maintenance of intestinal homeostasis, we have investigated human and murine CD8(+) Foxp3(+) T cells generated by stimulating naive CD8(+) T cells in the presence of transforming growth factor-? and retinoic acid, mediators that are abundantly produced in the intestinal mucosa. These CD8(+) Foxp3(+) fully competent regulatory T cells show strong expression of regulatory molecules CD25, Gpr83 and CTLA-4 and exhibit cell-cell contact-dependent immunosuppressive activity in vitro. Our study illustrates a previously unappreciated critical role of CD8(+) Foxp3(+) T cells in controlling potentially dangerous T cells and in the maintenance of intestinal homeostasis. PMID:21711349

Fleissner, Diana; Frede, Annika; Knott, Markus; Knuschke, Torben; Geffers, Robert; Hansen, Wiebke; Dobos, Gustav; Langhorst, Jost; Buer, Jan; Westendorf, Astrid M

2011-09-01

107

Generation and function of immunosuppressive human and murine CD8+ T cells by transforming growth factor-? and retinoic acid  

PubMed Central

The intestinal immune system is constantly challenged by foreign antigens and commensal bacteria. Therefore, proper control of the intestinal microenvironment is required. One important arm of this regulatory network consists of regulatory T cells. In contrast to CD4+ Foxp3+ regulatory T cells, which have been well characterized, immunomodulatory CD8+ T cells that express Foxp3 are less well defined in terms of their generation and function. Failures of these regulatory mechanisms contribute to the development of inflammatory bowel disease. In this study we demonstrate that the frequency of CD8+ Foxp3+ T cells is reduced in the peripheral blood of patients with ulcerative colitis. As these cells might play a currently underestimated role in the maintenance of intestinal homeostasis, we have investigated human and murine CD8+ Foxp3+ T cells generated by stimulating naive CD8+ T cells in the presence of transforming growth factor-? and retinoic acid, mediators that are abundantly produced in the intestinal mucosa. These CD8+ Foxp3+ fully competent regulatory T cells show strong expression of regulatory molecules CD25, Gpr83 and CTLA-4 and exhibit cell–cell contact-dependent immunosuppressive activity in vitro. Our study illustrates a previously unappreciated critical role of CD8+ Foxp3+ T cells in controlling potentially dangerous T cells and in the maintenance of intestinal homeostasis. PMID:21711349

Fleissner, Diana; Frede, Annika; Knott, Markus; Knuschke, Torben; Geffers, Robert; Hansen, Wiebke; Dobos, Gustav; Langhorst, Jost; Buer, Jan; Westendorf, Astrid M

2011-01-01

108

Decreased expression of retinoic acid receptors, transforming growth factor beta, involucrin, and cornifin in cervical intraepithelial neoplasia.  

PubMed

Cervical intraepithelial neoplasia (CIN) I, II, and III represent a spectrum of premalignant epithelial changes and are ideal targets for application of chemoprevention strategies. Intermediate end point biomarkers are increasingly being used as surrogate end points to monitor clinical chemoprevention trials. To identify potential biomarkers in cervical epithelium, we analyzed the expression of nuclear retinoic acid receptor (RAR) mRNA by in situ hybridization, involucrin, cornifin, and transforming growth factors (TGFs) beta1 and beta2 by immunohistochemistry in cervical specimens, which contained adjacent normal epithelium and CIN lesions from 52 patients. These biomarkers were expressed in all adjacent normal cervical epithelia, whereas all CIN lesions including CIN I, CIN II, and CIN III exhibited decreased expression of RAR-alpha by 55.8%, RAR-beta by 64.7%, RAR-gamma by 54.9%, involucrin by 80.8%, cornifin by 88.5%, TGF-beta1 by 89.7%, and TGF-beta2 by 85.7%. Viewed as a whole, these biomarkers were down-regulated in 100% of the CIN lesions. Because all of these biomarkers can be modulated in vitro by retinoids, they may serve as intermediate biomarkers for retinoid chemoprevention trials in the patients with CIN lesions. PMID:10389939

Xu, X C; Mitchell, M F; Silva, E; Jetten, A; Lotan, R

1999-06-01

109

Effects of short-term acid and aluminum exposure on the parr-smolt transformation in Atlantic salmon (Salmo salar): Disruption of seawater tolerance and endocrine status  

USGS Publications Warehouse

Episodic acidification resulting in increased acidity and inorganic aluminum (Ali) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either control (pH 6.7-6.9) or acid/Al (pH 5.4-6.3, 28-64 ??g l-1 Ali) conditions for 2 and 5 days, and impacts on freshwater (FW) ion regulation, seawater (SW) tolerance, plasma hormone levels and stress response were examined. Gill Al concentrations were elevated in all smolts exposed to acid/Al relative to controls confirming exposure to increased Ali. There was no effect of acid/Al on plasma ion concentrations in FW however, smolts exposed to acid/Al followed by a 24 h SW challenge exhibited greater plasma Cl- levels than controls, indicating reduced SW tolerance. Loss of SW tolerance was accompanied by reductions in gill Na+,K+-ATPase (NKA) activity and Na+,K+,2Cl- (NKCC) cotransporter protein abundance. Acid/Al exposure resulted in decreased plasma insulin-like growth factor (IGF-I) and 3,3???,5???-triiodo-l-thyronine (T3) levels, whereas no effect of treatment was seen on plasma cortisol, growth hormone (GH), or thyroxine (T4) levels. Acid/Al exposure resulted in increased hematocrit and plasma glucose levels in FW, but both returned to control levels after 24 h in SW. The results indicate that smolt development and SW tolerance are compromised by short-term exposure to acid/Al in the absence of detectable impacts on FW ion regulation. Loss of SW tolerance during short-term acid/Al exposure likely results from reductions in gill NKA and NKCC, possibly mediated by decreases in plasma IGF-I and T3. ?? 2008 Elsevier Inc.

Monette, M. Y.; Bjornsson, B. T.; McCormick, S. D.

2008-01-01

110

Determination of thermally induced trans-fatty acids in soybean oil by attenuated total reflectance fourier transform infrared spectroscopy and gas chromatography analysis.  

PubMed

The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 °C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm(-1) of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 °C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment. PMID:23025355

Li, An; Ha, Yiming; Wang, Feng; Li, Weiming; Li, Qingpeng

2012-10-24

111

Prolonged exposure to acid and bile induces chromosome abnormalities that precede malignant transformation of benign Barrett's epithelium  

PubMed Central

Abstract Barrett’s esophagus (BE) is an asymptomatic, pre-malignant condition of the esophagus that can progress to esophageal adenocarcinoma (EAC). BE arises typically in individuals with long-standing gastroesophageal reflux disease (GERD). The neoplastic progression of BE has been extensively studied histologically and defined as a metaplasia- dyplasia- carcinoma sequence. However the genetic basis of this process is poorly understood. It is conceived that preclinical models of BE may facilitate discovery of molecular markers due to ease of longitudinal sampling. Clinical markers to stratify the patients at higher risk are vital to institute appropriate therapeutic intervention since EAC has very poor prognosis. We developed a dynamic in-vitro BE carcinogenesis (BEC) model by exposing naïve Barrett’s epithelium cell line (BAR-T) to acid and bile at pH4 (B4), 5min/day for a year. The BEC model acquired malignant characteristics after chronic repeated exposure to B4 similar to the sequential progression of BE to EAC in vivo. Aim To study cytogenetic changes during progressive transformation in the BEC model. Results We observed that the BAR-T cells progressively acquired several chromosomal abnormalities in the BEC model. Evidence of chromosomal loss (-Y) rearrangements [t(10;16) and dup (11q)] and clonal selection appeared during the early stages of the BEC model. Clonal selection resulted in a stabilized monoclonal population of cells that had a changed morphology and formed colony in soft agar. BAR-T cells grown in parallel without any exposure did not show any of these abnormalities. Conclusions Prolonged acid and bile exposure induced chromosomal aberrations and clonal selection in benign BAR-T cells. Since aneuploidy preceded morphological/dysplastic changes in the BEC model, chromosomal aberrations may be an early predictor of BE progression. The [t(10;16) and dup(11q)] aberrations identified in this study harbor several genes associated with cancer and may be responsible for neoplastic behavior of cells. After further validation, in-vivo, they may be clinically useful for diagnosis of BE, progressing to dysplasia/esophageal adenocarcinoma. PMID:23194200

2012-01-01

112

Quantification of hydroxycinnamic acids and lignin in perennial forage and energy grasses by Fourier-transform infrared spectroscopy and partial least squares regression.  

PubMed

Levels of lignin and hydroxycinnamic acid wall components in three genera of forage grasses (Lolium,Festuca and Dactylis) have been accurately predicted by Fourier-transform infrared spectroscopy using partial least squares models correlated to analytical measurements. Different models were derived that predicted the concentrations of acid detergent lignin, total hydroxycinnamic acids, total ferulate monomers plus dimers, p-coumarate and ferulate dimers in independent spectral test data from methanol extracted samples of perennial forage grass with accuracies of 92.8%, 86.5%, 86.1%, 59.7% and 84.7% respectively, and analysis of model projection scores showed that the models relied generally on spectral features that are known absorptions of these compounds. Acid detergent lignin was predicted in samples of two species of energy grass, (Phalaris arundinacea and Pancium virgatum) with an accuracy of 84.5%. PMID:18796351

Allison, Gordon G; Thain, Simon C; Morris, Phillip; Morris, Catherine; Hawkins, Sarah; Hauck, Barbara; Barraclough, Tim; Yates, Nicola; Shield, Ian; Bridgwater, Anthony V; Donnison, Iain S

2009-02-01

113

Determination of uronic acids in isolated hemicelluloses from kenaf using diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and the curve-fitting deconvolution method.  

PubMed

Hemicellulose samples were isolated from kenaf (Hibiscus cannabinus L.). Hemicellulosic fractions usually contain a variable percentage of uronic acids. The uronic acid content (expressed in polygalacturonic acid) of the isolated hemicelluloses was determined by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and the curve-fitting deconvolution method. A linear relationship between uronic acids content and the sum of the peak areas at 1745, 1715, and 1600 cm(-1) was established with a high correlation coefficient (0.98). The deconvolution analysis using the curve-fitting method allowed the elimination of spectral interferences from other cell wall components. The above method was compared with an established spectrophotometric method and was found equivalent for accuracy and repeatability (t-test, F-test). This method is applicable in analysis of natural or synthetic mixtures and/or crude substances. The proposed method is simple, rapid, and nondestructive for the samples. PMID:17140480

Batsoulis, A N; Nacos, M K; Pappas, C S; Tarantilis, P A; Mavromoustakos, T; Polissiou, M G

2004-02-01

114

Ambient formic acid in southern California air: A comparison of two methods, Fourier transform infrared spectroscopy and alkaline trap-liquid chromatography with UV detection  

SciTech Connect

Formic acid is an ubiquitous component of urban smog. Sources of formic acid in urban air include direct emissions from vehicles and in situ reaction of ozone with olefins. Ambient levels of formic acid in southern California air were first measured some 15 years ago by Hanst et al. using long-path Fourier transform infrared spectroscopy (FTIR). All subsequent studies of formic acid in the Los Angeles area have involved the use of two methods, either FTIR or collection on alkaline traps followed by gas chromatography, ion chromatography, or liquid chromatography analysis with UV detection, ATLC-UV. The Carbon Species Methods Comparison Study (CSMCS), a multilaboratory air quality study carried out in August 1986 at a southern California smog receptor site, provided an opportunity for direct field comparison of the FTIR and alkaline trap methods. The results of the comparison are presented in this brief report.

Grosjean, D. (DGA, Inc., Ventura, CA (USA)); Tuazon, E.C. (Univ. of California, Riverside (USA)); Fujita, E. (California Air Resources Board, Sacramento (USA))

1990-01-01

115

Decreased Rubisco activity leads to dramatic changes of nitrate metabolism, amino acid metabolism and the levels of phenylpropanoids and nicotine in tobacco antisense RBCS transformants.  

PubMed

Tobacco transformants that express an antisense RBCS construct were used to investigate the consequences of a lesion in photosynthetic carbon metabolism for nitrogen metabolism and secondary metabolism. The results show that an inhibition of photosynthesis and decrease in sugar levels leads to a general inhibition of nitrogen metabolism, and dramatic changes in the levels of secondary metabolites. The response was particularly clear in plants that received excess nitrogen. In these conditions, a decrease of Rubisco activity led to an inhibition of nitrate reductase activity, accumulation of nitrate, a decrease of amino acid levels that was larger than the decrease of sugars, and a large decrease of chlorogenic acid and of nicotine, which are the major carbon- and nitrogen-rich secondary metabolites in tobacco leaves, respectively. Similar changes were seen when nitrogen-replete wild-type tobacco was grown in low light. The inhibition of nitrogen metabolism was partly masked when wild-type plants and antisense RBCS transformants were compared in marginal or in limiting nitrogen, because the lower growth rate of the transformants alleviated the nitrogen deficiency, leading to an increase of amino acids. In these conditions, chlorogenic acid always decreased but the decrease of nicotine was ameliorated or reversed. When the changes in internal pools are compared across all the genotypes and growth conditions, two conclusions emerge. First, decreased levels of primary metabolites lead to a dramatic decrease in the levels of secondary metabolites. Second, changes of the amino acid : sugar ratio are accompanied by changes of the nicotine:chlorogenic acid ratio. PMID:12061898

Matt, Petra; Krapp, Anne; Haake, Volker; Mock, Hans-Peter; Stitt, Mark

2002-06-01

116

Determination of omega-6 and omega-3 fatty acids in pork adipose tissue with nondestructive Raman and fourier transform infrared spectroscopy.  

PubMed

In order to predict omega-6 and omega-3 fatty acids in the diet of humans, seventy-three pork back fat adipose tissue samples were measured with Raman spectroscopy directly on adipose tissue and on melted fat. Melted fat samples were, in addition, measured with Fourier transform infrared (FT-IR) spectroscopy. Gas chromatography analyses were conducted as the reference analysis. Partial least squares regression (PLSR) was used to calibrate and validate all models predicting omega-3 and omega-6 fatty acids contents from spectra. Omega-6 fatty acids in melted fat measured with FT-IR was predicted with a correlation coefficient (R) of 0.93 and a root mean square error of cross-validation (RMSECV) of 1.61% of the total amount of fatty acids. Raman spectra measured on melted fat gave a prediction of omega-6 fatty acids with R=0.97, and RMSECV=0.99% of total amount of fatty acids. Omega-6 fatty acids were predicted with R=0.94, and RMSECV=1.50% of the total amount of fatty acids using Raman spectra recorded on adipose tissue. For omega-3 fatty acids, the highest R=0.91, and lowest RMSECV=0.23% of the total amount of fatty acids were obtained from Raman spectra acquired on melted fat. FT-IR and Raman spectroscopy may be used as rapid, nondestructive methods to determine omega-6 and omega-3 fatty acids in melted fat. Raman spectroscopy can also be used directly on adipose tissue. PMID:18801235

Olsen, Elisabeth Fjaervoll; Rukke, Elling-Olav; Egelandsdal, Bjørg; Isaksson, Tomas

2008-09-01

117

Long-chain polyunsaturated fatty acids interact with nitric oxide, superoxide anion, and transforming growth factor-? to prevent human essential hypertension  

Microsoft Academic Search

Patients with uncontrolled essential hypertension have elevated concentrations of superoxide anion (O2?•), hydrogen peroxide (H2O2), lipid peroxides, endothelin, and transforming growth factor-? (TGF-?) with a simultaneous decrease in endothelial nitric oxide (eNO), superoxide dismutase (SOD), vitamin E, and long-chain polyunsaturated fatty acids (LCPUFAs). Physiological concentrations of angiotensin II activate NAD(P)H oxidase and trigger free radical generation (especially that of O2?•).

U N Das

2004-01-01

118

Effects of methyl jasmonate and salicylic acid on cell growth and cryptotanshinone formation in Ti transformed Salvia miltiorrhiza cell suspension cultures  

Microsoft Academic Search

Exogenous methyl jasmonate (MJ) or salicylic acid (SA) when applied alone failed to induce cryptotanshinone (a phytoalexin) formation in Ti-transformed Salvia miltiorrhiza cell suspension cultures. However, when applied in combination with yeast elicitor, SA at 50–500 µM enhanced the yeast elicitor-induced cryptotanshinone formation while MJ reduced the yeast elicitor-induced cryptotanshinone formation. Ibuprofen at 100 µM did not inhibit the yeast elicitor-induced cryptotanshinone

Hui Chen; Feng Chen

1999-01-01

119

Fatty acid composition of spanish shortenings with special emphasis on trans unsaturation content as determined by fourier transform infrared spectroscopy and gas chromatography  

Microsoft Academic Search

A Fourier transform infrared spectroscopic procedure was used to analyze 34 edible fats (22 shortenings and 12 vegetable margarines)\\u000a as neat fats (IRNF) to determine their total trans fatty acid (TFA) content. The sloping baseline was corrected with a reference spectrum based on a nonprocessed olive oil.\\u000a The calibration was done using seven partially hydrogenated fats with an individual TFA

L. Alonso; M. J. Fraga; M. Juárez; P. Carmona

2002-01-01

120

Transformed and immortalized cellular uptake of oligodeoxynucleoside phosphorothioates, 3?-Alkylamino oligodeoxynucleotides, 2?- o-methyl oligoribonucleotides, oligodeoxynucleoside methylphosphonates, and peptide nucleic acids  

Microsoft Academic Search

Direct quantitative comparisons of cellular uptake across a wide variety of analogs and cell types are necessary for the design of oligonucleotide diagnostic and therapeutic applications. This work reports quantitative cellular uptake and nuclear localization of [14C]oligodeoxynucleoside phosphorothioates (PS), 3?-alkylamino Oligodeoxynucleoside phosphodiesters (PO-NH2), 2?-O-methyl oligoribonucleoside phosphodiesters (2OM), peptide nucleic acids (PNA), and oligodeoxynucleoside methylphosphonates (MP) in several transformed or immortalized

Gary D. Gray; Soumitra Basu; Eric Wickstrom

1997-01-01

121

Development of a nuclear transformation system for Oleaginous Green Alga Lobosphaera (Parietochloris) incisa and genetic complementation of a mutant strain, deficient in arachidonic acid biosynthesis.  

PubMed

Microalgae are considered a promising source for various high value products, such as carotenoids, ?-3 and ?-6 polyunsaturated fatty acids (PUFA). The unicellular green alga Lobosphaera (Parietochloris) incisa is an outstanding candidate for the efficient phototrophic production of arachidonic acid (AA), an essential ?-6 PUFA for infant brain development and a widely used ingredient in the baby formula industry. Although phototrophic production of such algal products has not yet been established, estimated costs are considered to be 2-5 times higher than competing heterotrophic production costs. This alga accumulates unprecedented amounts of AA within triacylglycerols and the molecular pathway of AA biosynthesis in L. incisa has been previously elucidated. Thus, progress in transformation and metabolic engineering of this high value alga could be exploited for increasing the efficient production of AA at competitive prices. We describe here the first successful transformation of L. incisa using the ble gene as a selection marker, under the control of the endogenous RBCS promoter. Furthermore, we have succeeded in the functional complementation of the L. incisa mutant strain P127, containing a mutated, inactive version of the delta-5 (?5) fatty acid desaturase gene. A copy of the functional ?5 desaturase gene, linked to the ble selection marker, was transformed into the P127 mutant. The resulting transformants selected for zeocine resistant, had AA biosynthesis partially restored, indicating the functional complementation of the mutant strain with the wild-type gene. The results of this study present a platform for the successful genetic engineering of L. incisa and its long-chain PUFA metabolism. PMID:25133787

Zorin, Boris; Grundman, Omer; Khozin-Goldberg, Inna; Leu, Stefan; Shapira, Michal; Kaye, Yuval; Tourasse, Nicolas; Vallon, Olivier; Boussiba, Sammy

2014-01-01

122

Analysis of chromosomes, nucleic acids, and polypeptides in hamster cells transformed by herpes simplex virus type 2.  

PubMed

Syrian hamster embryo fibroblasts were oncogenically transformed by UV-inactivated Herpes simplex type 2. Eighteen clones were isolated shortly after transformation occurred. Two clones and their tumor derivatives were studied using several techniques. The karyotype analysis revealed different chromosome patterns in the two clones and a tendency toward hypodiploidy in the tumor derivatives. All of these cell lines were shown by molecular hybridization to contain 40% of the HSV-genome in several copies. The viral DNA sequence complexity was retained in the tumor derivatives, but a decrease in the copy number was observed. Viral RNA's were detected by in situ hybridization in all the lines that were tested. Viral antigens could be observed in these transformed cells by immunofluorescence. Finally, polypeptide analysis showed three differences between normal and transformed cells. PMID:222446

Kessous, A; Bibor-Hardy, V; Suh, M; Simard, R

1979-08-01

123

Lactic Acid is Elevated in Idiopathic Pulmonary Fibrosis and Induces Myofibroblast Differentiation Via pH-Dependent Activation of Transforming Growth Factor-?  

SciTech Connect

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex disease for which the pathogenesis is poorly understood. In this study, we identified lactic acid as a metabolite that is elevated in the lung tissue of patients with IPF. Objectives: This study examines the effect of lactic acid on myofibroblast differentiation and pulmonary fibrosis. Methods:We used metabolomic analysis to examine cellular metabolism in lung tissuefrom patients with IPFanddeterminedthe effects of lactic acid and lactate dehydrogenase-5 (LDH5) overexpression on myofibroblast differentiation and transforming growth factor (TGF)-b activation in vitro. Measurements and Main Results: Lactic acid concentrations from healthy and IPF lung tissue were determined by nuclear magnetic resonance spectroscopy; a-smooth muscle actin, calponin, and LDH5 expression were assessed by Western blot of cell culture lysates. Lactic acid and LDH5 were significantly elevated in IPF lung tissue compared with controls. Physiologic concentrations of lactic acid induced myofibroblast differentiation via activation of TGF-b. TGF-b induced expression of LDH5 via hypoxia-inducible factor 1a (HIF1a). Importantly, overexpression of both HIF1a and LDH5 in human lung fibroblasts induced myofibroblast differentiation and synergized with low dose TGF-b to induce differentiation. Furthermore, inhibition of both HIF1a and LDH5 inhibited TGF-b–induced myofibroblast differentiation. Conclusions: We have identified the metabolite lactic acid as an important mediator of myofibroblast differentiation via a pHdependent activation of TGF-b. We propose that the metabolic milieu of the lung, and potentially other tissues, is an important driving force behind myofibroblast differentiation and potentially the initiation and progression of fibrotic disorders.

Kottman, R. M.; Kulkarni, Ajit A.; Smolnycki, Katie A.; Lyda, Elizabeth; Dahanayake, Thinesh; Salibi, Rami; Honnons, Sylvie; Jones, Carolyn; Isern, Nancy G.; Hu, Jian Z.; Nathan, Steven D.; Grant, Geraldine; Phipps, Richard P.; Sime, Patricia J.

2012-10-15

124

Chemical and physical transformations of aluminosilicate clay minerals due to Acid treatment and consequences for heterogeneous ice nucleation.  

PubMed

Mineral dust aerosol is one of the largest contributors to global ice nuclei, but physical and chemical processing of dust during atmospheric transport can alter its ice nucleation activity. In particular, several recent studies have noted that sulfuric and nitric acids inhibit heterogeneous ice nucleation in the regime below liquid water saturation in aluminosilicate clay minerals. We have exposed kaolinite, KGa-1b and KGa-2, and montmorillonite, STx-1b and SWy-2, to aqueous sulfuric and nitric acid to determine the physical and chemical changes that are responsible for the observed deactivation. To characterize the changes to the samples upon acid treatment, we use X-ray diffraction, transmission electron microscopy, and inductively coupled plasma-atomic emission spectroscopy. We find that the reaction of kaolinite and montmorillonite with aqueous sulfuric acid results in the formation of hydrated aluminum sulfate. In addition, sulfuric and nitric acids induce large structural changes in montmorillonite. We additionally report the supersaturation with respect to ice required for the onset of ice nucleation for these acid-treated species. On the basis of lattice spacing arguments, we explain how the chemical and physical changes observed upon acid treatment could lead to the observed reduction in ice nucleation activity. PMID:25211030

Sihvonen, Sarah K; Schill, Gregory P; Lyktey, Nicholas A; Veghte, Daniel P; Tolbert, Margaret A; Freedman, Miriam Arak

2014-09-25

125

The Effect of Y-zeolite Acidity on m-Xylene Transformation Reactions S. Al-Khattaf*  

E-print Network

as compared to disproportionation reaction. The p-xylene/o-xylene (P/O) was established to be independent-xylene. A convenient way to upgrade the low-valued m-xylene consists of its transformation to o- and p-xylene

Al-Khattaf, Sulaiman

126

A Simple and Efficient Synthesis of an Acid-labile Polyphosphoramidate by Organobase-catalyzed Ring-Opening Polymerization and Transformation to Polyphosphoester Ionomers by Acid Treatment  

PubMed Central

The direct synthesis of an acid-labile polyphosphoramidate by organobase-catalyzed ring-opening polymerization and an overall two-step preparation of polyphosphodiester ionomers (PPEI) by acid-assisted cleavage of the phosphoramidate bonds along the backbone of the polyphosphoramidate were developed in this study. The ultrafast organobase-catalyzed ring-opening polymerization of a cyclic phospholane methoxyethyl amidate monomer initiated by benzyl alcohol allowed for the preparation of well-defined polyphosphoramidates (PPA) with predictable molecular weights, narrow molecular weight distributions (PDI<1.10), and well-defined chain ends. Cleavage of the acid-labile phosphoramidate bonds on the polyphosphoramidate repeat units was evaluated under acidic conditions over a pH range of 1–5, and the complete hydrolysis produced polyphosphodiesters. The thermal properties of the resulting polyphosphoester ionomer acid and polyphosphoester ionomer sodium salt exhibited significant thermal stability. The parent PPA and both forms of the PPEIs showed low cytotoxicities toward HeLa cells and RAW 264.7 mouse macrophage cells. The synthetic methodology developed here has enriched the family of water-soluble polymers prepared by rapid and convenient organobase-catalyzed ring-opening polymerizations and straightforward chemical medication reactions, which are designed to be hydrolytically degradable and have promise for numerous biomedical and other applications. PMID:23997276

Zhang, Shiyi; Wang, Hai; Shen, Yuefei; Zhang, Fuwu; Seetho, Kellie; Zou, Jiong; Taylor, John-Stephen A.; Dove, Andrew P.; Wooley, Karen L.

2013-01-01

127

Transformational Learners: Transformational Teachers  

ERIC Educational Resources Information Center

Transformational learning, according to Mezirow (1981), involves transforming taken-for-granted frames of reference into more discriminating, flexible "habits of mind". In teacher education, transformative learning impacts on the development of students' action theories, self-efficacy and professional attributes. Although considered imperative to…

Jones, Marguerite

2009-01-01

128

The Transformations of Transformations.  

ERIC Educational Resources Information Center

Harris's original idea of transformations has been changed several times in Chomsky's work. This article explicates these transformations, arguing that though their motivations are highly understandable, these transformations are not necessary for understanding the workings of natural languages. (Author/VWL)

Lin, Francis Y.

2000-01-01

129

Hydrothermal syntheses and structures of the uranyl tellurates AgUO{sub 2}(HTeO{sub 5}) and Pb{sub 2}UO{sub 2}(TeO{sub 6})  

SciTech Connect

Two uranyl tellurates, AgUO{sub 2}(HTeO{sub 5}) (1) and Pb{sub 2}UO{sub 2}(TeO{sub 6}) (2), were synthesized under hydrothermal conditions and were structurally, chemically, and spectroscopically characterized. 1 crystallizes in space group Pbca, a=7.085(2) A, b=11.986(3) A, c=13.913(4) A, V=1181.5(5) A{sup 3}, Z=8; 2 is in P2(1)/c, a=5.742(1) A, b=7.789(2) A, c=7.928(2) A, V=90.703(2) A{sup 3}, and Z=2. These are the first structures reported for uranyl compounds containing tellurate. The U{sup 6+} cations are present as (UO{sub 2}){sup 2+} uranyl ions that are coordinated by O atoms to give pentagonal and square bipyramids in compounds 1 and 2, respectively. The structural unit in 1 is a sheet consisting of chains of edge-sharing uranyl pentagonal bipyramids that are one bipyramid wide, linked through the dimers of TeO{sub 6} octahedra. In 2, uranyl square bipyramids share each of their equatorial vertices with different TeO{sub 6} octahedra, giving a sheet with the autunite-type topology. Sheets in 1 and 2 are connected through the low-valence cations that are located in the interlayer region. The structures of 1 and 2 are compared to those of uranyl compounds containing octahedrally coordinated cations. -- Graphical abstract: Two hydrothermally synthesized uranyl tellurates, AgUO{sub 2}(HTeO{sub 5}) and Pb{sub 2}UO{sub 2}(TeO{sub 6}), contain sheets built from uranyl pentagonal or square bipyramids, as well as tellurate octahedra. Display Omitted Research highlights: > Compounds AgUO{sub 2}(HTeO{sub 5}) and Pb{sub 2}UO{sub 2}(TeO{sub 6}) are the first uranyl tellurate compounds. > The structure of AgUO{sub 2}(HTeO{sub 5}) consists of sheets of uranyl pentagonal bipyramids and TeO{sub 6} octahedra. > The structure of Pb{sub 2}UO{sub 2}(TeO{sub 6}) contains sheets of TeO{sub 6} octahedra and uranyl square bipyramids.

Ling, Jie; Ward, Matthew [Department of Civil Engineering and Geological Science, University of Notre Dame, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.ed [Department of Civil Engineering and Geological Science, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

2011-02-15

130

Stability of fatty acid monolayers and the relationship between equilibrium spreading pressure, phase transformations, and polymorphic crystal forms  

Microsoft Academic Search

Force-area isotherms were obtained for hexa- decanoic, octadecanoic, eicosanoic, and docosanoic acid mono- layers at different compression rates. Equilibrium spreading pressures were determined both by monolayer collapse and by spreading from the bulk phase. Monolayers formed metastable phases at all pressures above their equilibrium spreading pressures and at all surface areas smaller than the surface areas at their equilibrium spreading

RICHARD E. HEIKKILA; CHUI N. KWONG; DAVID G. CORNWELL

131

CHEMISTRY OF FOG WATER IN CALIFORNIA'S CENTRAL VALLEY: 2. PHOTOCHEMICAL TRANSFORMATIONS OF AMINO ACIDS AND ALKYL AMINES. (R825433)  

EPA Science Inventory

Although amino compounds are seemingly ubiquitous in atmospheric particles and deposition, little is known of their fate in the troposphere. We report here on the fate of 21 amino acids and alkyl amines in fog waters from Davis, California, illuminated with simulated sunlight ...

132

Fourier Transform Infrared Spectroscopy and Multivariate Analysis for Online Monitoring of Dibutyl Phosphate Degradation Product in Tributyl Phosphate /n-Dodecane/Nitric Acid Solvent  

SciTech Connect

In liquid-liquid extraction separation processes, accumulation of organic solvent degradation products is detrimental to the process robustness and frequent solvent analysis is warranted. Our research explores feasibility of online monitoring of the organic solvents relevant to used nuclear fuel reprocessing. This paper describes the first phase of developing a system for monitoring the tributyl phosphate (TBP)/n-dodecane solvent commonly used to separate used nuclear fuel. In this investigation, the effect of extraction of nitric acid from aqueous solutions of variable concentrations on the quantification of TBP and its major degradation product dibutyl phosphoric acid (HDBP) was assessed. Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy was used to discriminate between HDBP and TBP in the nitric acid-containing TBP/n-dodecane solvent. Multivariate analysis of the spectral data facilitated the development of regression models for HDBP and TBP quantification in real time, enabling online implementation of the monitoring system. The predictive regression models were validated using TBP/n-dodecane solvent samples subjected to the high dose external gamma irradiation. The predictive models were translated to flow conditions using a hollow fiber FTIR probe installed in a centrifugal contactor extraction apparatus demonstrating the applicability of the FTIR technique coupled with multivariate analysis for the online monitoring of the organic solvent degradation products.

Levitskaia, Tatiana G.; Peterson, James M.; Campbell, Emily L.; Casella, Amanda J.; Peterman, Dean; Bryan, Samuel A.

2013-11-05

133

Fourier Transform Infrared Spectroscopy and Multivariate Analysis for Online Monitoring of Dibutyl Phosphate Degradation Product in Tributyl Phosphate/n-Dodecane/Nitric Acid Solvent  

SciTech Connect

In liquid–liquid extraction separation processes, accumulation of organic solvent degradation products is detrimental to the process robustness, and frequent solvent analysis is warranted. Our research explores the feasibility of online monitoring of the organic solvents relevant to used nuclear fuel reprocessing. This paper describes the first phase of developing a system for monitoring the tributyl phosphate (TBP)/n-dodecane solvent commonly used to separate used nuclear fuel. In this investigation, the effect of extraction of nitric acid from aqueous solutions of variable concentrations on the quantification of TBP and its major degradation product dibutylphosphoric acid (HDBP) was assessed. Fourier transform infrared (FTIR) spectroscopy was used to discriminate between HDBP and TBP in the nitric acid-containing TBP/n-dodecane solvent. Multivariate analysis of the spectral data facilitated the development of regression models for HDBP and TBP quantification in real time, enabling online implementation of the monitoring system. The predictive regression models were validated using TBP/n-dodecane solvent samples subjected to high-dose external ?-irradiation. The predictive models were translated to flow conditions using a hollow fiber FTIR probe installed in a centrifugal contactor extraction apparatus, demonstrating the applicability of the FTIR technique coupled with multivariate analysis for the online monitoring of the organic solvent degradation products.

Tatiana G. Levitskaia; James M. Peterson; Emily L. Campbell; Amanda J. Casella; Dean R. Peterman; Samuel A. Bryan

2013-12-01

134

Retinoic acid alters hindbrain Hox code and induces transformation of rhombomeres 2\\/3 into a 4\\/5 identity  

Microsoft Academic Search

IT has been suggested that Hox genes play an important part in the patterning of limbs1-3, vertebrae4-6 and craniofacial structures5,7-9 by providing an ordered molecular system of positional values, termed the Hox code10,11. Little is known about the nature of the signals that govern the establishment and regulation of Hox genes, but retinoic acid can affect the expression of these

Heather Marshall; Stefan Nonchev; Mai Har Sham; Ian Muchamore; Andrew Lumsden; Robb Krumlauf

1992-01-01

135

Measurement of conjugated linoleic acid (CLA) in CLA-rich soy oil by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR).  

PubMed

Conjugated linoleic acid (CLA) isomers in oils are currently measured as fatty acid methyl esters by a gas chromatography-flame ionization detector (GC-FID) technique, which requires approximately 2 h to complete the analysis. Hence, we aim to develop a method to rapidly determine CLA isomers in CLA-rich soy oil. Soy oil with 0.38-25.11% total CLA was obtained by photo-isomerization of 96 soy oil samples for 24 h. A sample was withdrawn at 30 min intervals with repeated processing using a second batch of oil. Six replicates of GC-FID fatty acid analysis were conducted for each oil sample. The oil samples were scanned using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the spectrum was collected. Calibration models were developed using partial least-squares (PLS-1) regression using Unscrambler software. Models were validated using a full cross-validation technique and tested using samples that were not included in the calibration sample set. Measured and predicted total CLA, trans,trans CLA isomers, total mono trans CLA isomers, trans-10,cis-12 CLA, trans-9,cis-11 CLA and cis-10,trans-12 CLA, and cis-9,trans-11 CLA had cross-validated coefficients of determinations (R2v) of 0.97, 0.98, 0.97, 0.98, 0.97, and 0.99 and corresponding root-mean-square error of validation (RMSEV) of 1.14, 0.69, 0.27, 0.07, 0.14, and 0.07% CLA, respectively. The ATR-FTIR technique is a rapid and less expensive method for determining CLA isomers in linoleic acid photo-isomerized soy oil than GC-FID. PMID:19860450

Kadamne, Jeta V; Jain, Vishal P; Saleh, Mohammed; Proctor, Andrew

2009-11-25

136

The evolution of self-assemblies in the mixed system of oleic acid-diethylenetriamine based on the transformation of electrostatic interactions and hydrogen bonds.  

PubMed

With the aid of pH variation, the fine control of the electrostatic interaction and hydrogen bond was realised in the mixed system of oleic acid and diethylenetriamine. Owing to the transformation of the intermolecular interactions, the corresponding building blocks changed from DETA(2+)@2OA(-)via the coexistence of DETA@2OA(-) and DETA(+)@OA(-) to DETA@2OA(-). Therefore, diverse microstructures and phase behaviors in this mixed surfactant system were obtained at the different pH values. It is found that the fine control of the electrostatic interaction and hydrogen bond is efficient for tailoring the self-assembled structures in this cationic-anionic surfactant system, including vesicles, bilayers, networks formed by aggregated vesicles and fibers. PMID:25159624

Zhou, Chengcheng; Cheng, Xinhao; Zhao, Oudi; Liu, Shuai; Liu, Chenjiang; Wang, Jide; Huang, Jianbin

2014-09-24

137

Altered sensitivity of system A amino acid transport to ouabain in normal and transformed C3H-10T1/2 cells during the cell cycle.  

PubMed

Quiescent C3H-10T1/2 mouse fibroblasts that have not undergone any type of stress have a relatively low rate of 2-aminoisobutyrate (Aib) uptake by means of system A, which is primarily energized by the transmembrane Na+ chemical gradient potential. System A activity in these cells is not sensitive to ouabain or proton ionophores. In contrast, methylcholanthrene-transformed and confluent C3H-10T1/2 cells treated with 0.4 mM ouabain for 16-20 hr utilize the membrane potential generated by the Na+, K+-ATPase pump to drive Aib transport by means of system A as shown by the sensitivity of transport activity to ouabain and proton ionophores. Since glucose is present during the assay, the proton ionophores do not affect the availability of ATP, as indicated by the undiminished uptake of 86Rb+ by the Na+, K+-ATPase pump. As cells progress through the G1 phase of the cell cycle, they show an increased system A activity prior to entry into the S phase, which is also dependent on the electrogenicity of the Na+, K+-ATPase pump. There appears to be in all these cases a qualitative shift in the bioenergetic mechanism for the uptake of Aib as well as a marked quantitative increase in Aib uptake. The high activity after ouabain treatment was sustained in the transformed cells after removal of the ouabain, whereas in the confluent 10T1/2 cells the rate of uptake decayed rapidly, suggesting a difference in the mode of regulation. We conclude that transformed cells and normal cells in late G1 or under stress make use of the membrane potential generated by the Na+, K+-ATPase pump to drive amino acid uptake by means of system A. PMID:2536932

Leister, K J; Schenerman, M A; Racker, E

1989-02-01

138

A 16-amino acid peptide from human alpha2-macroglobulin binds transforming growth factor-beta and platelet-derived growth factor-BB.  

PubMed

Alpha2-macroglobulin (alpha2M) is a major carrier of transforming growth factor-beta (TGF-beta) in vitro and in vivo. By screening glutathione S-transferase (GST) fusion proteins with overlapping sequences, we localized the TGFbeta-binding site to aa 700-738 of the mature human alpha2M subunit. In separate experiments, we screened overlapping synthetic peptides corresponding to aa 696-777 of alpha2M and identified a single 16-mer (718-733) that binds TGF-beta1. Platelet-derived growth factor-BB (PDGF-BB) bound to the same peptide, even though TGF-beta and PDGF-BB share almost no sequence identity. The sequence of the growth factor-binding peptide, WDLVVVNSAGVAEVGV, included a high proportion of hydrophobic amino acids. The analogous peptide from murinoglobulin, a human alpha2M homologue that does not bind growth factors, contained only three nonconservative amino acid substitutions; however, the MUG peptide failed to bind TGF-beta1 and PDGF-BB. These results demonstrate that a distinct and highly-restricted site in alpha2M, positioned near the C-terminal flank of the bait region, mediates growth factor binding. At least part of the growth factor-binding site is encoded by exon 18 of the alpha2M gene, which is notable for a 5' splice site polymorphism that has been implicated in Alzheimer's Disease. PMID:11106172

Webb, D J; Roadcap, D W; Dhakephalkar, A; Gonias, S L

2000-10-01

139

A 16-amino acid peptide from human alpha2-macroglobulin binds transforming growth factor-beta and platelet-derived growth factor-BB.  

PubMed Central

Alpha2-macroglobulin (alpha2M) is a major carrier of transforming growth factor-beta (TGF-beta) in vitro and in vivo. By screening glutathione S-transferase (GST) fusion proteins with overlapping sequences, we localized the TGFbeta-binding site to aa 700-738 of the mature human alpha2M subunit. In separate experiments, we screened overlapping synthetic peptides corresponding to aa 696-777 of alpha2M and identified a single 16-mer (718-733) that binds TGF-beta1. Platelet-derived growth factor-BB (PDGF-BB) bound to the same peptide, even though TGF-beta and PDGF-BB share almost no sequence identity. The sequence of the growth factor-binding peptide, WDLVVVNSAGVAEVGV, included a high proportion of hydrophobic amino acids. The analogous peptide from murinoglobulin, a human alpha2M homologue that does not bind growth factors, contained only three nonconservative amino acid substitutions; however, the MUG peptide failed to bind TGF-beta1 and PDGF-BB. These results demonstrate that a distinct and highly-restricted site in alpha2M, positioned near the C-terminal flank of the bait region, mediates growth factor binding. At least part of the growth factor-binding site is encoded by exon 18 of the alpha2M gene, which is notable for a 5' splice site polymorphism that has been implicated in Alzheimer's Disease. PMID:11106172

Webb, D. J.; Roadcap, D. W.; Dhakephalkar, A.; Gonias, S. L.

2000-01-01

140

Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s as high-efficiency catalysts for carbonyl-group transformation reactions.  

PubMed

Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s [M(Cp)(2)][OSO(2)C(8)F(17)](2)?nH(2)O?THF (M = Zr (2?a?3?H(2)O?THF), M = Ti (2?b?2?H(2)O?THF)) were synthesized by the reaction of [M(Cp)(2)]Cl(2) (M = Zr (1?a), M = Ti (1?b)) with nBuLi and C(8)F(17)SO(3)H (2?equiv) or with C(8)F(17)SO(3)Ag (2?equiv). The hydrate numbers (n) of these complexes were variable, changing from 0 to 4 depending on conditions. In contrast to well-known metallocene triflates, these complexes suffered no change in open air for a year. thermogravimetry-differential scanning calorimetry (TG-DSC) analysis showed that 2?a and 2?b were thermally stable at 300 and 180?°C, respectively. These complexes exhibited unusually high solubility in polar organic solvents. Conductivity measurement showed that the complexes (2?a and 2?b) were ionic dissociation in CH(3)CN solution. X-ray analysis result confirmed 2?a?3?H(2)O?THF was a cationic organometallic Lewis acid. UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2?a. Fluorescence spectra showed that the Lewis acidity of 2?a fell between those of Sc(3+) (?(em)=474?nm) and Fe(3+) (?(em)=478?nm). ESR spectra showed the Lewis acidity of 2?a (0.91?eV) was at the same level as that of Sc(3+) (1.00?eV) and Y(3+) (0.85?eV), while the Lewis acidity of 2?b (1.06?eV) was larger than that of Sc(3+) (1.00?eV) and Y(3+) (0.85?eV). They showed high catalytic ability in carbonyl-compound transformation reactions, such as the Mannich reaction, the Mukaiyama aldol reaction, allylation of aldehydes, the Friedel-Crafts acylation of alkyl aromatic ethers, and cyclotrimerization of ketones. Moreover, the complexes possessed good reusability. On account of their excellent catalytic efficiency, stability, and reusability, the complexes will find broad catalytic applications in organic synthesis. PMID:22504964

Qiu, Renhua; Xu, Xinhua; Peng, Lifeng; Zhao, Yalei; Li, Ningbo; Yin, Shuangfeng

2012-05-14

141

Reaction mechanism and metal ion transformation in photocatalytic ozonation of phenol and oxalic acid with Ag(+)/TiO2.  

PubMed

Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag(+)/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag(+) greatly promoted the photocatalytic degradation of contaminants due to its role as an electron scavenger. It also accelerated the removal rate of OA in ozonation and the simultaneous process for its complex reaction with oxalate. Phenol could be degraded both in direct ozonation and photolysis, but the TOC removal rates were much higher in the simultaneous processes due to the oxidation of hydroxyl radicals resulting from synergetic effects. The sequence of photo-illumination and ozone exposure in the combined process showed quite different effects in phenol degradation and TOC removal. The synergetic effects in different combined processes were found to be highly related to the properties of the target pollutants. The color change of the solution and TEM result confirmed that Ag(+) was easily reduced and deposited on the surface of TiO2 under photo-illumination, and dissolved again into solution in the presence of ozone. This simple cycle of enrichment and distribution of Ag(+) can greatly benefit the design of advanced oxidation processes, in which the sequences of ozone and photo-illumination can be varied according to the needs for catalyst recycling and the different properties of pollutants. PMID:25079280

Chen, Yingying; Xie, Yongbing; Yang, Jun; Cao, Hongbin; Zhang, Yi

2014-03-01

142

Retinoic acid resistance at late stages of human papillomavirus type 16-mediated transformation of human keratinocytes arises despite intact retinoid signaling and is due to a loss of sensitivity to transforming growth factor-beta.  

PubMed

In our in vitro model of human cell carcinogenesis, normal human foreskin keratinocytes (HKc) transfected with human papillomavirus type 16 DNA (HKc/HPV16) progress toward malignancy through several phenotypically defined and reproducible "steps" that include immortalization, growth factor independence (HKc/GFI), differentiation resistance (HKc/DR), and ultimately malignant conversion. While HKc/HPV16 are very sensitive to growth inhibition by all-trans-retinoic acid (RA) at early passages, they lose their sensitivity to RA during progression in culture. However, gel mobility shift assays using the retinoid response elements DR1 and DR5 showed no changes in binding activity of nuclear extracts obtained from HKc/HPV16 at different stages of in vitro progression. Similarly, Western blot analyses for retinoic acid receptor gamma-1 and the retinoid X receptors failed to reveal any decreases in the levels of these retinoid receptors throughout progression. In addition, luciferase activity driven by the SV40 promoter with a DR5 enhancer element was activated following RA treatment of HKc/DR that were resistant to growth inhibition by RA. Since RA induces transforming growth factor-beta2 (TGF-beta2) in normal HKc and HKc/HPV16, we investigated whether this response changed during progression. Again, RA induced TGF-beta2 mRNA in early and late passage HKc/HPV16, HKc/GFI, and HKc/DR approximately to the same extent, confirming that the RA signaling pathways remained intact during in vitro progression despite the fact that the cells become resistant to growth inhibition by RA. We then investigated the sensitivity of HKc/HPV16 to growth inhibition by TGF-beta. While early passage HKc/HPV16 were as sensitive as normal HKc to growth inhibition by TGF-beta1 and TGF-beta2, the cells became increasingly resistant to both TGF-beta isotypes during in vitro progression. In addition, while both RA and TGF-beta produced a decrease in the levels of mRNA for the HPV16 oncogenes E6 and E7 in early passage HKc/HPV16, this effect was also lost at later stages of progression. Finally, blocking anti-TGF-beta antibodies partially prevented RA inhibition of growth and E6/E7 expression in early passage HKc/HPV16. Taken together, these data strongly suggest that inhibition of growth and HPV16 early gene expression in HKc/HPV16 by RA is mediated by TGF-beta and that a loss of RA sensitivity is linked to TGF-beta resistance rather than alterations in RA signaling. PMID:10792999

Borger, D R; Mi, Y; Geslani, G; Zyzak, L L; Batova, A; Engin, T S; Pirisi, L; Creek, K E

2000-05-10

143

Localization of transforming growth factor alpha and its receptor in gastric mucosal cells. Implications for a regulatory role in acid secretion and mucosal renewal.  

PubMed Central

Transforming growth factor alpha (TGF alpha) shares with epidermal growth factor (EGF) structural homology (35%), a common cell-surface membrane receptor (TGF alpha/EGF receptor), and a nearly identical spectrum of biological activity, including inhibition of gastric acid secretion. Herein, we report expression of TGF alpha mRNA in normal gastric mucosa of the adult guinea pig, rat, and dog. TGF alpha mRNA was also detected in matched surgically resected gastric mucosa and adjacent gastric carcinoma from 10 patients, and in gastric mucosa adjacent to a benign ulcer from an additional patient. TGF alpha protein was quantitated by radioimmunoassay and was present in tumor and adjacent mucosa. TGF alpha/EGF receptor mRNA was also detected in gastric mucosa from all species studied. Localization of TGF alpha and TGF alpha/EGF receptor mRNA expression was examined in samples of unfractionated guinea pig gastric mucosa and from chief cell-enriched and parietal cell-enriched fractions. All samples exhibited TGF alpha and TGF alpha/EGF receptor expression. The TGF alpha signal was greatest in the parietal cell fraction (5.8-fold increase), but was also enhanced in the chief cell fraction (1.9-fold increase) relative to the unfractionated gastric mucosa. Like TGF alpha expression, TGF alpha/EGF receptor mRNA expression was most intense in the parietal cell-enriched fraction (7.8-fold increase), but was also increased in the chief cell-enriched fraction (2.7-fold increase) relative to the unfractionated guinea pig gastric mucosa. We conclude that TGF alpha and TGF alpha/EGF receptor genes are expressed in normal adult mammalian gastric mucosa. These findings, when interpreted in light of described actions of TGF alpha and EGF, provide evidence that local production of TGF alpha could play an important role in the regulation of acid secretion and mucosal renewal in the stomach. Images PMID:2760208

Beauchamp, R D; Barnard, J A; McCutchen, C M; Cherner, J A; Coffey, R J

1989-01-01

144

Sulindac sulfide and caffeic acid phenethyl ester suppress the motility of lung adenocarcinoma cells promoted by transforming growth factor-beta through Akt inhibition.  

PubMed

Cell migration is essential for invasive and metastatic phenotypes of cancer cells. Potential chemopreventive agents of cancer-sulindac sulfide, caffeic acid phenethyl ester (CAPE), curcumin, and (+)-catechin-have been reported to interfere with several types of intracellular signaling. In this study, we examined the effects of these agents on transforming growth factor-beta(TGF-beta)-induced motility and Akt phosphorylation in A549 cells. Judged by gold particle phagokinesis assay, sulindac sulfide, CAPE, and curcumin suppressed the motility of A549 cells promoted by TGF-beta. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase(PI3K)/Akt signaling, also suppressed TGF-beta-induced motility and Akt phosphorylation. Sulindac sulfide and CAPE, but not curcumin, suppressed TGF-beta-induced Akt phosphorylation. We conclude that sulindac sulfide and CAPE suppress the motility promoted by TGF-beta in lung adenocarcinoma cells through the suppression of Akt. Our observations raise the possibility that these agents, except for (+)-catechin, can be applied not only as chemopreventive agents but also as anti-metastatic therapy. PMID:14691717

Shigeoka, Yasushi; Igishi, Tadashi; Matsumoto, Shingo; Nakanishi, Hirofumi; Kodani, Masahiro; Yasuda, Kazuhito; Hitsuda, Yutaka; Shimizu, Eiji

2004-03-01

145

Morphology transformations in tetrabutyl titanate-acetic acid system and sub-micron/micron hierarchical TiO2 for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

The concentration of tetrabutyl titanate (TBT) and H2O influence on the reaction kinetics of TBT and acetic acid (AcOH) solvothermal system are systematically studied. It is found that TBT and H2O have greatly accelerated the hydrolysis-condensation process of the TBT-AcOH system. By adjusting those concentrations with reaction time, we prepare five kinds of sub-micron/micron precursors, which are hierarchical structures consisting of different primary building blocks. The morphology of these precursors varies from noninterlaced structures composed of flower-like microsphere and ellipsoid sphere to interlaced structures composed of flower-like microsphere interlaced nanofibers, ellipsoid spheres interlaced flower-like microsphere and nanoparticles interlaced flower-like microsphere. These interlaced structures are synthesized for the first time and are not ordinary mixtures of the noninterlaced structures. After heat treatment, these precursors are transformed to anatase TiO2. Shape-dependent photovoltaic performances of dye-sensitized solar cells (DSSCs) are also discussed. DSSCs based on these hierarchical sub-micron/micron TiO2 show 7.3%-7.9% energy conversion efficiencies, and the devices based on interlaced structures have higher efficiencies (7.4%-7.9%) than those of the devices based on noninterlaced structures (7.3%-7.6%).

Huang, Niu; Xie, Yanan; Sebo, Bobby; Liu, Yumin; Sun, Xiaohua; Peng, Tao; Sun, Weiwei; Bu, Chenghao; Guo, Shishang; Zhao, Xingzhong

2013-11-01

146

Modeling Transformation  

E-print Network

Modeling Transformation What does each step do? #12;Transformation Procedure #12;Transformation Procedure #12;Building Your Model Yarn = chromosomal DNA Beads = ribosomes Black velcro = plasmid DNA Green velcro = GFP gene Pink velcro

Rose, Michael R.

147

Acid rain  

Microsoft Academic Search

The causes and effects of acid rain are detailed. Sulfur dioxide and nitrogen dioxide emissions from anthropogenic sources are the primary causative agents. These emissions are transported over long distances and transformed into sulfates and nitrates and washed out of the atmosphere. Trends in acidity in precipitation water are reviewed for eastern portions of Canada and the U.S. Adverse effects

R. E. Ghelardi; B. L. Murphy

2009-01-01

148

All-trans retinoic acid attenuates the renal interstitial fibrosis lesion in rats but not by transforming growth factor-?1/Smad3 signaling pathway.  

PubMed

All-trans retinoic acid (ATRA) is an important therapeutic agent for prevention of the renal diseases. Transforming growth factor-?1 (TGF-?1)/Smad3 signaling pathway is a key signaling pathway which takes part in the progression of renal interstitial fibrosis (RIF). This investigation was performed to study the effect of ATRA in RIF rats and its effect on the TGF-?1/Smad3 signaling pathway. Sixty Wistar male rats were divided into three groups at random: sham operation group (SHO), model group subjected to unilateral ureteral obstruction (GU), model group treated with ATRA (GA), n = 20, respectively. RIF index, protein expression of TGF-?1, collagen-IV (Col-IV) and fibronectin (FN) in renal interstitium, and mRNA and protein expressions of Smad3 in renal tissue were detected at 14-day and 28-day after surgery. The RIF index was markedly elevated in group GU than in SHO group (p < 0.01), and the RIF index of GA group was alleviated when compared with that in GU group (p < 0.01). Compared with in group SHO, the mRNA/protein expression of Smad3 in renal tissue was significantly increased in group GU (p < 0.01). However, the mRNA and protein expressions of Smad3 in renal tissue in GA group were not markedly alleviated by ATRA treatment when compared with those in GU (each p > 0.05). Protein expressions of TGF-?1, Col-IV, and FN in GU group were markedly increased than those in SHO group (each p < 0.01), and their expressions in GA group were markedly down-regulated by ATRA treatment than those of GU group (all p < 0.01). The protein expression of Smad3 was positively correlated with RIF index, protein expression of TGF-?1, Col-IV or FN (each p < 0.01). In conclusion, ATRA treatment can alleviate the RIF progression in UUO rats. However, ATRA cannot affect the signaling pathway of TGF-?1/Smad3 in the progression of RIF. PMID:23176567

Li, Zheng-Yi; Zhou, Tian-Biao; Qin, Yuan-Han; Su, Li-Na; Xu, Hui-Ling; Lei, Feng-Ying

2013-01-01

149

Fate of transforming deoxyribonucleic acid after uptake by competent Bacillus subtilis: phenotypic characterization of radiation-sensitive recombination-deficient mutants.  

PubMed

A collection of 16 isogenic recombination-deficient strains of Bacillus subtilis isolated on the basis of sensitivity to methyl methane sulfonate (MMS) or mitomycin C (MC) were characterized phenotypically. All were found to be somewhat sensitive to ultraviolet irradiation, MC, and MMS. The mutants were all blocked in "late" steps in the transformation process and were provisionally grouped into four categories on the basis of the various properties examined. Class I mutants were deficient in transformation and heterologous transduction with phage PBS1 but were transducible with homologous donors at nearly the wild-type frequency. They were blocked in donor-recipient complex (DRC) formation but formed essentially normal amounts of double-strand fragments (DSF) and single-strand fragments (SSF). The class IIa strain was deficient in transformation and PBS1 transduction, and formed DRC which was normal by all available physical and biological criteria. Class IIb mutants were deficient in transformation and PBS1 transduction, and failed to form DRC. They did produce DSF and SSF. Class III mutants were deficient in transformation, were normal in PBS1 transduction, and formed DRC which was physically indistinguishable from that of the Rec(+) parent although with slightly lowered donor-type transforming activity. Class IV strains were deficient in PBS1 transduction but were transformed at nearly the wild-type efficiency. None of the mutant strains was deficient in the adenosine triphosphate-dependent deoxyribonuclease. PMID:4349031

Dubnau, D; Davidoff-Abelson, R; Scher, B; Cirigliano, C

1973-04-01

150

Wavelet transforms versus Fourier transforms  

Microsoft Academic Search

This note is a very basic introduction to wavelets. It starts with an orthogonal basis of piecewise constant functions, constructed by dilation and translation. The ``wavelet transform'' maps each $f(x)$ to its coefficients with respect to this basis. The mathematics is simple and the transform is fast (faster than the Fast Fourier Transform, which we briefly explain), but approximation by

Gilbert Strang

1993-01-01

151

Biosynthesis of phenylalanine, tyrosine, 3-(3-carbocyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine in higher plants. Examples of the transformation possibilities for chorismic acid.  

PubMed

14C-labelled shikimic acid and double labelled shikimic acid tritiated stereospicifically at C-6 are incorporated into 3-(3-carboxyphenyl) alanine, 3-(3-carboxy-4-hydroxyphenyl) alanine, phenylalanine, and tyrosine in Reseda lutea L., Reseda odorata L., Iris x Hollandica cv. Prof. Blauw, and Iris x hollandica cv. Wedgwood. The experiments with 14C-labelled shikimic acid confirm that the aromatic carboxyl groups and rings in 3-(3-carboxyphenyl) alanine and 3-(3-carbocy-4-hydroxyphenyl) alanine derive from the carbocyl group and ring in shikimic acid whereas the experiments with double labelled shikimic acid demonstrate that the pro-6S-hydrogen atom is retained and the pro-6R-hydrogen atom lost in the biosynthesis of 3-(3-carboxyphenyl) alanine, phenylalanine, and tyrosine in the plants used. 3H was located in the ortho-position in the aromatic rings of phenylalanine and tyrosine but in a position para to the alanine side chain of 3- (3-carboxyphenly) alanine. No 3H was found in 3- (3-carboxy-4-hydroxyphenyl) alanine. This supports a derivation of the last two compounds from chorismic acid via isochorismic acid, isoprephenic acid, and 3'-carboxyphenylpyruvic acid and 3'-carbocy-4'-hydroxyphenylphruvic acid. The 3H/14C ratio in 3-(3-carboxyphenyl) alanine was found higher than in the precursor used. This isotope effect must operate by competition between the pathways from isoprephenic acid to 3'-carbocyphenylpyruvic acid and to 3'-carbocy-4'- hydroxyphenylpyruvic acic. The proposed biosynthetic pathways for the two carboxy-substituted amino acids are in agreement with their distribution patterns in the plant kingdom and suggest that they may derive from minor changes of enzymes involved in the general pathways of aromatic biosynthesis. PMID:1120151

Larsen, P O; Onderka, D K; Floss, H G

1975-02-13

152

Agrobacterium -mediated Transformation of Brassica juncea with a Cyanobacterial ( Synechocystis PCC6803) Delta6 Desaturase Gene Leads to Production of Gamma-linolenic Acid  

Microsoft Academic Search

Genetic manipulation of the oil-yielding crop plants for better oil quality through biotechnological methods is an important aspect of crop improvement. Due to the inherent absence of the ?6-desaturase (d6D) function, Brassica juncea, an oil-yielding crop plant, is unable to synthesize ?-linolenic acid (GLA), a nutritionally important fatty acid although the crop plant synthesizes the precursor fatty acids required for

Biswajit Das; Lily Goswami; Sudipta Ray; Shilpi Ghosh; Sanghamitra Bhattacharyya; Sampa Das; Arun Lahiri Majumder

2006-01-01

153

The Epstein-Barr virus LMP1 amino acid sequence that engages tumor necrosis factor receptor associated factors is critical for primary B lymphocyte growth transformation.  

PubMed

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) is essential for transforming primary B lymphocytes into lymphoblastoid cell lines. EBV recombinants with LMP1 genes truncated after the proximal 45 codons of the LMP1 carboxyl terminus are adequate for transformation. The proximal 45 residues include a domain that engages the tumor necrosis factor receptor associated factors (TRAFs). We investigated the importance of the TRAF binding domain by assaying the transforming ability of recombinant EBV genomes with a deletion of LMP1 codons 185-211. This mutation eliminates TRAF association in yeast and in lymphoblasts but does not affect LMP1 stability or localization. Specifically mutated recombinant EBV genomes were generated by transfecting P3HR-1 cells with overlapping EBV cosmids. Infection of primary B lymphocytes resulted in cell lines that were coinfected with an LMP1 delta185-211 EBV recombinant and P3HR-1 EBV, which has a wild-type LMP1 gene but is transformation defective due to another deletion. Despite the equimolar mixture of wild-type and mutated LMP1 genes in virus preparations from five coinfected cell lines, only the wild-type LMP1 gene was found in 412 cell lines obtained after transformation of primary B lymphocytes. No transformed cell line had only the LMP1 delta185-211 gene. An EBV recombinant with a Flag-tagged LMP1 gene passaged in parallel segregated from the coinfecting P3HR-1. These data indicate that the LMP1 TRAF binding domain is critical for primary B lymphocyte growth transformation. PMID:9037073

Izumi, K M; Kaye, K M; Kieff, E D

1997-02-18

154

Differentiation of diastereomeric cyclic beta-amino acids by varying the neutral reagent in ion/molecule reactions studied by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Stereochemical differentiation of diasteromeric pairs of cis- and trans-2-aminocyclohexane-, -2-amino-4-cyclohexene-, and -2-aminocyclopentanecarboxylic acids was investigated with host-guest complexes where tetraethyl resorcarene was the host molecule. Diastereoselectivity was evaluated by ion/molecule reactions and collision-induced dissociation with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS). The effect of varying the neutral reagent (n-propylamine, i-propylamine, diethylamine, and triethylamine) in ion/molecule reactions was evaluated. Both steric interactions and proton affinity of the neutral reagents influenced the reaction rates. High proton affinity of the neutral reagent apparently had a twofold effect. If the proton affinity of the neutral reagent was too high, the reaction tended to become too exothermic and part of the host-guest complex decomposed instead of transforming to a new host-guest complex, effecting a decrease in the reaction rate. The remaining portion of the host-guest complexes meanwhile reacted very fast with the neutral reagent due to high proton affinity causing an increase in the reaction rate. n-Propylamine and i-propylamine proved to be the best neutral reagents, providing clear diastereoselectivity for beta-amino acids in ion/molecule reactions. Interestingly, diastereoselectivity was better for flexible cyclohexane beta-amino acids (2 and 3) than for more rigid cyclopentane beta-amino acids (6 and 7). The results of ab initio and hybrid density functional theory calculations on the structures of the host-guest complexes of saturated beta-amino acids were in good agreement with the experimental results. PMID:18181235

Hyyryläinen, Anna R M; Pakarinen, Jaana M H; Vainiotalo, Pirjo; Fülöp, Ferenc

2008-01-01

155

Animating Transformations  

NSDL National Science Digital Library

In most introductory linear algebra courses, prominent applications of transformations or mappings are moving (rotating, reflecting, translating), resizing (contracting, expanding), changing the shape (shearing, projecting) objects in the plane. A typical problem in such courses is to write the matrix of a transformation that changes points in such prescribed ways. The goal of this demo is to help students more easily visualize such transformations on a wide class of plane objects.

Roberts, Lila F.; Hill, David R.

2003-01-24

156

Solids modeled by ab initio crystal field methods, part 22: the Fock matrix transformed supermolecule model and the structure determination of D-erythronic acid-3,4-carbonate.  

PubMed

To eliminate the cutoff effects in the supermolecule model (SM), the Fock matrix transformed supermolecule model (FTSM) is developed. In this model a cyclization of the cluster is performed by means of transformations of elements of the Fock matrix, thereby restoring the translational symmetry. Besides this fundamental enhancement, significant CPU time savings are realized because, in this new procedure, not all Fock matrix elements need to be calculated. The method is applied in a study of the structure of D-erythronic acid-3,4-carbonate in the crystal phase, where the new model is compared to the supermolecule model as well as the XRD experiment. The results are found to be in good agreement with experimental data. PMID:15484183

van Droogenbroeck, Joris; Swerts, Ben; Schäfer, Lothar; van Alsenoy, Christian

2004-12-01

157

Transformational Events  

ERIC Educational Resources Information Center

Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

Denning, Peter J.; Hiles, John E.

2006-01-01

158

Comparative study of lanostane-type triterpene acids in different parts of Poria cocos (Schw.) Wolf by UHPLC-Fourier transform MS and UHPLC-triple quadruple MS.  

PubMed

Poria cocos (Schw.) Wolf is widely used as a traditional Chinese medicine, and approximately 10% of traditional Chinese medicinal preparations contain this material, according to the Chinese Pharmacopoeia (2010 edition). Although the epidermis (fulingpi in Chinese, or FLP) and the inner parts (baifuling in Chinese, or BFL) of P. cocos had different therapeutic applications in history, studies pertaining to a comparative analysis of their chemical constituents have been scarce. UHPLC-DAD-FT/MS(n) has been used in the current study to identify the triterpene acids present in fungus based on a detailed analysis of the fragmentation behavior of 13 standard compounds. This analysis allowed for the identification of 27 triterpene acids, including five groups of isomers and four potential new compounds. Furthermore, a UHPLC-MS/MS method has been developed for quantifying the amounts of nine bioactive triterpene acids in samples of the FLP and BFL, including three 3,4-seco-lanostane-type triterpene acids. These results revealed significant differences in the amounts of these compounds in the FLP and BFL samples. Principal component analysis and partial least squares discriminant analysis of the results for the FLP and BFL samples clearly demonstrated that dehydrotumulosic acid, trametenolic acid, dehydrotrametenolic acid and poricoic acid A were the main compounds contributing to the clusters in FLP and BFL. The observed differences in the chemical compositions of FLP and BFL could provide some explanation of the differences in their clinic applications. This study represents the first reported comprehensive analysis of lanostane-type triterpene acids in FLP and BFL parts of P. cocos. PMID:25282601

Wang, Weihao; Dong, Hongjing; Yan, Renyi; Li, Hua; Li, Pengyue; Chen, Ping; Yang, Bin; Wang, Zhimin

2015-01-01

159

Transforming California  

NSDL National Science Digital Library

Transforming California is a PowerPoint presentation of digital images (60.7 Mb) exploring the landforms found along the San Andreas Fault. Designed for classroom use, this slideshow provides a complementing narrative for each slide.

Mcguire, Thomas

2001-01-01

160

Transformative copy  

E-print Network

The ability to create an unlimited number of identical copies is a privilege of digital documents. What if that would not be the case, if each copy of a digital file would go along with some sort of transformation? This ...

Offenhuber, Dietmar

2008-01-01

161

Triple transformation  

NASA Astrophysics Data System (ADS)

A new business plan that enables policy transformation and resource mobilization at the national and international level, while improving access to resources, will allow the Green Climate Fund to integrate development goals and action on climate change.

Khan, Farrukh I.; Schinn, Dustin S.

2013-08-01

162

Covariant Transform  

NASA Astrophysics Data System (ADS)

Dedicated to the memory of Cora Sadosky The paper develops theory of covariant transform, which is inspired by the wavelet construction. It was observed that many interesting types of wavelets (or coherent states) arise from group representations which are not square integrable or vacuum vectors which are not admissible. Covariant transform extends an applicability of the popular wavelets construction to classic examples like the Hardy space H2, Banach spaces, covariant functional calculus and many others.

Kisil, Vladimir V.

2011-03-01

163

Cotton Transformation  

Microsoft Academic Search

Cotton has been cultured in vitro for 37 years, yet even today, some of the culture difficulties that were seen when it was\\u000a first cultured, namely, a very long culture time and a limited number of cultivars that can be cultured, continue to pose\\u000a problems. These inherent tissue culture limitations have made transforming cotton an arduous process. Transforming embryogenic\\u000a callus

D. R. Duncan

164

Molecular distribution, seasonal variation, chemical transformation and sources of dicarboxylic acids and related compounds in atmospheric aerosols at remote marine Gosan site, Jeju Island  

NASA Astrophysics Data System (ADS)

: A homologous series of C2-C12 ?, ?-dicarboxylic acids, ?-oxocarboxylic acids (C2-C9), pyruvic acid and ?-dicarbonyls (C2-C3) were detected in atmospheric aerosols collected between April 2003 and April 2004 from remote marine Gosan site (33°29? N, 126°16? E) located in Jeju Island, South Korea. They were determined using a GC-FID and GC/MS. Total diacid concentration ranged from 130 to 1911 ng m-3 (av. 642 ng m-3), whereas total oxoacid concentration ranged from 7 to 155 ng m-3 (av. 43 ng m-3), and pyruvic acid and ?-dicarbonyls ranged from 0.5 to 15 ng m-3 (av. 5 ng m-3) and 2-108 ng m-3 (av. 17.3 ng m-3), respectively. Oxalic (C2) acid was the most abundant in all seasons followed by malonic (C3) or succinic (C4) acid, and phthalic (Ph) acid. The concentration of diacids decreased with an increase in carbon number except for azelaic (C9) acid, which was more abundant than suberic (C8) acid. Glyoxylic acid was predominant ?-oxoacid contributing to 92% of total ?-oxoacid. Total diacids, oxoacids and dicarbonyls showed maximum concentrations in spring and occasionally in winter, while minimum concentrations were observed in summer. Air mass trajectory analysis suggests that either spring or winter maxima can be explained by strong continental outflow associated with cold front passages, while summer minima are associated with warm southerly flows, which transport clean marine air from low latitudes to Jeju Island. The comparison between total diacid concentration level of this study and other study results of urban and remote sites of East Asia reveals that Gosan site is more heavily influenced by the continental outflow from China. The seasonal variation of malonic/succinic (C3/C4), malic/succinic (hC4/C4), fumaric/maleic (F/M), oxalic/pyruvic (C2/Py) and oxalic/Glyoxal (C2/Gly) ratios showed maxima in summer due to an enhanced photo-production and degradation of diacids and related compounds. Throughout all seasons C3/C4 ratio at Gosan site, located between Chinese cities and Chichi-jima Island in Japan was observed higher than those in Chinese cities and lower than that of the Chichi-jima Island, pointing to the formation of diacid during long range transport. The lowest values of adipic/azelaic (C6/C9) and phthalic/azelaic (Ph/C9) were observed as a result of the overwhelming biogenic emission of the precursors (e.g., unsaturated fatty acids) of azelaic acid in summer.In this study, we will also discuss the sources and transport pathways of diacids and related compounds resolved using a hybrid receptor model, potential source contribution function (PSCF) and model results will be compared with available in-situ observations in East Asia.

Kundu, S.; Kawamura, K.; Lee, M.

2009-12-01

165

Transformations of Toxic Metals and Metalloids by Pseudomonas stutzeri Strain KC and its Siderophore Pyridine2,6-bis(thiocarboxylic acid)  

Microsoft Academic Search

\\u000a Pyridine-2,6-bis(thiocarboxylic acid)Pyridine-2,6-bis(thiocarboxylic acid) (pdtc)(pdtc) is a siderophore produced by Pseudomonas stutzeri KCPseudomonas stutzeri KC that plays a role in conditioning the bacterial environment. It serves as a siderophore in solubilizing\\u000a ferric iron and other micronutrient metals, and as a thiol-containing compound, it reacts with toxic heavy metals and metalloids,\\u000a reducing metals like Cr(VI), Se(IV), and Te(IV) and precipitating metals as

Anna M. Zawadzka; Andrzej J. Paszczynski; Ronald L. Crawford

166

Fourier transform infrared spectroscopy for the prediction of fatty acid profiles in Mucor fungi grown in media with different carbon sources.  

PubMed

Fungal production of polyunsaturated fatty acids (PUFAs) is a highly potential approach in biotechnology. Currently the main focus is directed towards screening of hundreds strains in order to select of few potential ones. Thus, a reliable method for screening a high number of strains within a short period of time is needed. Here, we present a novel method for screening of PUFA-producing fungi by high-throughput microcultivation and FTIR spectroscopy. In the study selected Mucor fungi were grown in media with different carbon sources and fatty acid profiles were predicted on the basis of the obtained spectral data. FTIR spectra were calibrated against fatty acid analysis by GC-FD. The calibration models were cross-validated and correlation coefficients (R2) from 0.71 to 0.78 with RMSECV (root mean squared error) from 2.86% to 6.96% (percentage of total fat) were obtained. The FTIR results show a strong correlation to the results obtained by GC analysis, where high total contents of unsaturated fatty acids (both PUFA and MUFA) were achieved for Mucor plumbeus VI02019 cultivated in canola, olive and sunflower oil and Mucor hiemalis VI01993 cultivated in canola and olive oil. PMID:25208488

Shapaval, Volha; Afseth, Nils Kristian; Vogt, Gjermund; Kohler, Achim

2014-01-01

167

TERATOGENIC EFFECTS OF RETINOIC ACID ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR AND TRANSFORMING GROWTH FACTOR-ALPHA  

EPA Science Inventory

Background: EGF and TGF regulate cell proliferation and differentiation in the embryo. The induction of cleft palate (CP) by all trans retinoic acid (RA) was associated with altered expression of TGF, EGF receptor and binding of EGF. The present study uses knockout (KO) mice to e...

168

In situ monitoring of sulfuric acid decomposition by Fourier transform infrared (FT-IR) spectroscopy in the sulfur iodine thermochemical reaction for the production of hydrogen  

Microsoft Academic Search

A potential way to produce large amounts of hydrogen for energy needs is the thermal breakdown of sulfuric acid (H2SO4) to oxygen, water, and sulfur dioxide (SO2). The sulfur dioxide can then be reacted with iodide to produce hydrogen iodide and ultimately hydrogen. In order to maximize the efficiency of the process it would be ideal to make in situ

Dion Rivera

2005-01-01

169

SHARP transformation  

NASA Astrophysics Data System (ADS)

The U.S. Navy"s SHAred Reconnaissance Pod (SHARP) employs the Recon/Optical, Inc. (ROI) CA-279 dual spectral band (visible/IR) digital cameras operating from an F-18E/F aircraft to perform low-to-high altitude reconnaissance missions. SHARP has proven itself combat worthy, with a rapid transition from development to operational deployment culminating in a highly reliable and effective reconnaissance capability for joint forces operating in Operation Iraqi Freedom (OIF). The U.S. Navy"s intelligence, surveillance and reconnaissance (ISR) roadmap transforms the SHARP system from being solely an independent reconnaissance sensor to a node in the growing Joint ISR network. ROI and the U.S. Navy have combined their resources to ensure the system"s transformation continues to follow the ISR road map. Pre-planned product improvements (P3I) for the CA-270 camera systems will lead the way in that transformation.

Wyatt, Stephan

2004-08-01

170

Prediction of protein structural classes by Chou’s pseudo amino acid composition: approached using continuous wavelet transform and principal component analysis  

Microsoft Academic Search

A prior knowledge of protein structural classes can provide useful information about its overall structure, so it is very\\u000a important for quick and accurate determination of protein structural class with computation method in protein science. One\\u000a of the key for computation method is accurate protein sample representation. Here, based on the concept of Chou’s pseudo-amino\\u000a acid composition (AAC, Chou, Proteins:

Zhan-Chao Li; Xi-Bin Zhou; Zong Dai; Xiao-Yong Zou

2009-01-01

171

Dynamic kinetic resolution of 1,3-dihydro-2H-isoindole-1-carboxylic acid methyl ester: asymmetric transformations toward isoindoline carbamates.  

PubMed

Asymmetric syntheses of isoindoline carbamates have been successfully achieved through enzyme-mediated dynamic kinetic resolution processes and without requirement of metal or acid-base catalyst for the substrate racemization. Optically active carbamates were obtained in good yields and an excellent degree of stereoselectivity when Pseudomonas cepacia lipase (PSL) was used as biocatalyst, with diallyl or dibenzyl carbonates being both adequate reagents in alkoxycarbonylation reactions. PMID:22417293

Morán-Ramallal, Roberto; Gotor-Fernández, Vicente; Laborda, Pedro; Sayago, Francisco J; Cativiela, Carlos; Gotor, Vicente

2012-04-01

172

Transformation of inert PbSO 4 deposit on the negative electrode of a lead-acid battery into its active state  

Microsoft Academic Search

Different forms of lead sulfate (PbSO4) are produced in both the cathode and anode in the course of discharging of a lead-acid battery. However, their difference in reaction activity has not been well recognized up to now. From this work, it is shown the cathode product PbSO4(O) due to oxidation of Pb is rather inert and its accumulation could lead

Bo Zhang; Juhua Zhong; Wenjun Li; Zhongyi Dai; Zhenmin Cheng

2010-01-01

173

Fourier Transform Pairs The Fourier transform transforms a function of  

E-print Network

Fourier Transform Pairs The Fourier transform transforms a function of time, f(t), into a function of frequency, F(s): F {f(t)}(s) = F(s) = Z - f(t)e- j2st dt. The inverse Fourier transform transforms a func. The inverse Fourier transform of the Fourier trans- form is the identity transform: f(t) = Z - Z - f()e- j2s

Masci, Frank

174

8R-Lipoxygenase-catalyzed synthesis of a prominent cis-epoxyalcohol from dihomo-?-linolenic acid: a distinctive transformation compared with S-lipoxygenases[S  

PubMed Central

Conversion of fatty acid hydroperoxides to epoxyalcohols is a well known secondary reaction of lipoxygenases, described for S-specific lipoxygenases forming epoxyalcohols with a trans-epoxide configuration. Here we report on R-specific lipoxygenase synthesis of a cis-epoxyalcohol. Although arachidonic and dihomo-?-linolenic acids are metabolized by extracts of the Caribbean coral Plexaura homomalla via 8R-lipoxygenase and allene oxide synthase activities, 20:3?6 forms an additional prominent product, identified using UV, GC-MS, and NMR in comparison to synthetic standards as 8R,9S-cis-epoxy-10S-erythro-hydroxy-eicosa-11Z,14Z-dienoic acid. Both oxygens of 18O-labeled 8R-hydroperoxide are retained in the product, indicating a hydroperoxide isomerase activity. Recombinant allene oxide synthase formed only allene epoxide from 8R-hydroperoxy-20:3?6, whereas two different 8R-lipoxygenases selectively produced the epoxyalcohol.A biosynthetic scheme is proposed in which a partial rotation of the reacting intermediate is required to give the observed erythro epoxyalcohol product. This characteristic and the synthesis of cis-epoxy epoxyalcohol may be a feature of R-specific lipoxygenases. PMID:22158855

Jin, Jing; Boeglin, William E.; Cha, Jin K.; Brash, Alan R.

2012-01-01

175

Exploring Transformations  

NSDL National Science Digital Library

In this activity, students will explore transformations of an absolute value function. Step by step instructions guide students in using graphing calculators to examine the effect that stretching and translating has on the coordinates of the graph. Teacher notes and a worksheet are also included to aid in teaching this lesson.

2011-11-25

176

Transformation & Metamorphosis  

ERIC Educational Resources Information Center

The sculptures of Canadian artist Brian Jungen are a great inspiration for a lesson on creating new forms. Jungen transforms found objects into unique creations without fully concealing their original form or purpose. Frank Stella's sculpture series, including "K.132,2007" made of stainless steel and spray paint, is another great example of…

Lott, Debra

2009-01-01

177

Transforming Schools.  

ERIC Educational Resources Information Center

The authors in this book address the issues that relate to the crisis in American education and review some of the proposed solutions. To transform education, schools must be examined as social systems that are interrelated with families, communities, and the world of work. Following the introduction, section 1, "Conditions for Educational…

Cookson, Peter W., Jr., Ed.; Schneider, Barbara, Ed.

178

Transformation Optics  

NASA Astrophysics Data System (ADS)

Transformation optics applies ideas from Einstein's general theory of relativity in optical and electrical engineering for designing devices that can do the (almost) impossible: invisibility cloaking, perfect imaging, levitation, and the creation of analogues of the event horizon. This chapter gives an introduction to this field requiring minimal prerequisites.

Leonhardt, Ulf

179

Development of a multichannel Fourier-transform spectrometer to measure weak chemiluminescence: Application to the emission of singlet-oxygen dimol in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6  

NASA Astrophysics Data System (ADS)

A Fourier-transform spectrometer equipped with a Savart-plate polarization interferometer was developed for observation of weak chemiluminescence and applied to a measurement of emission spectra in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6]. The band appearing at ˜580 nm in the chemiluminescence spectrum was assigned to the emission of singlet-oxygen dimol, the peak wavelength being shifted from that observed in the reaction of hydrogen peroxide with sodium hypochlorite, ˜633 nm. The band intensity was increased with the increasing concentration of K 3[Fe(CN) 6] up to ˜100 mM, and thereafter the peak wavelength was shifted from 580 to 700 nm with a decrease in the intensity.

Tsukino, Kazuo; Satoh, Toshihiro; Ishii, Hiroshi; Nakata, Munetaka

2008-05-01

180

Transformations Journal  

NSDL National Science Digital Library

Different forms of communication have always had a tendency to transform interactions and everyday life in ways that have surprised people from many different backgrounds. Academics have long been interested in such dynamic transformations, and this electronic journal represents one of the responses to such processes. As their site notes, this journal is "dedicated to the exploration of ideas, issues and debates emerging out of contemporary global culture." Visitors to the site can read the complete version of every issue on the site, and they will be pleased to find such intriguing titles as "Rethinking Regionality", "Accidental Environments", and "Fleeing the City". Interested parties can also consult the site to learn about the journal's editorial board, their calls for papers, submission guidelines, and related links.

181

An experimental investigation of Lewis acid-base interactions of liquid carbon dioxide using Fourier Transform Infrared (FT-IR) spectroscopy  

NASA Astrophysics Data System (ADS)

Presented here is an investigation into the solvent properties of liquid carbon dioxide by means of FT-IR spectroscopy. A high-pressure, circulation-type apparatus was designed and built specifically for this study. The spectra for the combination bands for carbon dioxide show that there are interactions between methanol and carbon dioxide. However, the spectra of the fundamental O-D vibration of deuterated methanol in liquid carbon dioxide indicate that there is no hydrogen bonding. Therefore. we conclude that the interactions between carbon dioxide and methanol are Lewis acid-base interactions rather than hydrogen bonding. This conclusion is supported by experiments where acetone is introduced into the CO2/methanol- d binary system. FT-IR measurements show that acetone hydrogen bonds with deuterated methanol.

Reilly, J. T.; Bokis, C. P.; Donohue, M. D.

1995-05-01

182

Pulse transformers  

Microsoft Academic Search

Pulse transformers capable of transmitting substantially rectangular voltage pulses, with durations of less than one microsecond, were developed for radar applications during World War II. Their primary functions were to match the impedances of high-power microwave radio-frequency electron-tube generators to electronic pulse generators and coaxial transmission cables, and to provide polarity reversal and impedance matching functions within pulse generator circuitry.

H. Lord

1971-01-01

183

Organic additive, 5-methylsalicylic Acid induces spontaneous structural transformation of aqueous pluronic triblock copolymer solution: a spectroscopic investigation of interaction of curcumin with pluronic micellar and vesicular aggregates.  

PubMed

This article presents the interaction of curcumin in the microenvironments provided by aggregation of pluronic triblock copolymer P123 into micellar and vesicular assemblies. The formation of vesicles using triblock copolymer P123 and 5-methylsalicylic acid (5 mS) has been successfully characterized by optical spectroscopy, light scattering measurement, and eventually microscopic techniques. Besides, to make a comparative study between the polymeric micelles, we have also investigated the photophysical changes of curcumin in F127 triblock copolymer micelles having variation in poly(ethylene oxide) (PPO) and poly(propylene oxide) (PEO) unit of polymer chain to that of P123. Time-dependent UV-vis measurement suggests that these polymer micelles are able to stabilize poorly water-soluble curcumin by suppressing the degradation rate in micellar nanocavity. However, experimental observations suggest that P123 micelles are more efficient than F127 to perturb excited state intramolecular proton transfer (ESIPT)-related nonradiative decay of curcumin. We also observed that rigid and confined microenvironment of P123/5 mS vesicles enhances emission intensity and lifetime of curcumin more compared to P123 micelles. All the observations suggest that modulation of photophysics of curcumin is responsible due to its interaction with poly(ethylene oxide) or poly(propylene oxide) unit of triblock copolymer. PMID:25192258

Ghosh, Surajit; Kuchlyan, Jagannath; Banik, Debasis; Kundu, Niloy; Roy, Arpita; Banerjee, Chiranjib; Sarkar, Nilmoni

2014-10-01

184

Hamlet's Transformation.  

NASA Astrophysics Data System (ADS)

William Shakespeare's Hamlet has much evidence to suggest that the Bard was aware of the cosmological models of his time, specifically the geocentric bounded Ptolemaic and Tychonic models, and the infinite Diggesian. Moreover, Shakespeare describes how the Ptolemaic model is to be transformed to the Diggesian. Hamlet's "transformation" is the reason that Claudius, who personifies the Ptolemaic model, summons Rosencrantz and Guildenstern, who personify the Tychonic. Pantometria, written by Leonard Digges and his son Thomas in 1571, contains the first technical use of the word "transformation." At age thirty, Thomas Digges went on to propose his Perfit Description, as alluded to in Act Five where Hamlet's age is given as thirty. In Act Five as well, the words "bore" and "arms" refer to Thomas' vocation as muster-master and his scientific interest in ballistics. England's leading astronomer was also the father of the poet whose encomium introduced the First Folio of 1623. His oldest child Dudley became a member of the Virginia Company and facilitated the writing of The Tempest. Taken as a whole, such manifold connections to Thomas Digges support Hotson's contention that Shakespeare knew the Digges family. Rosencrantz and Guildenstern in Hamlet bear Danish names because they personify the Danish model, while the king's name is latinized like that of Claudius Ptolemaeus. The reason Shakespeare anglicized "Amleth" to "Hamlet" was because he saw a parallel between Book Three of Saxo Grammaticus and the eventual triumph of the Diggesian model. But Shakespeare eschewed Book Four, creating this particular ending from an infinity of other possibilities because it "suited his purpose," viz. to celebrate the concept of a boundless universe of stars like the Sun.

Usher, P. D.

1997-12-01

185

Rotary Transformer  

NASA Technical Reports Server (NTRS)

None given. From first Par: Many spacecraft (S/C) and surface rovers require the transfer of signals and power across rotating interfaces. Science instruments, antennas and solar arrays are elements needing rotary power transfer for certain (S/C) configurations. Delivery of signal and power has mainly been done by using the simplest means, the slip ring approach. This approach, although simple, leaves debris generating noise over a period of time...The rotary transformer is a good alternative to slip rings for signal and power transfer.

McLyman, Colonel Wm. T.

1996-01-01

186

Corn transformed  

SciTech Connect

Researchers have produced fertile corn transformed with a foreign gene that makes the plants resistant to the herbicide bialaphos. This achievement, is the first report of fertile transgenic corn in the reviewed literature, and it is the capstone of almost a decade's efforts to genetically engineer this country's most important crop. The only other major crop to be so manipulated is rice. The ability produce transgenic corn gives biologists a valuable tool to probe the whys and hows of gene expression and regulation. It may also give plant breeders a way to develop new corn varieties with a speed and predictability that would be impossible with classical breeding techniques.

Moffat, A.S.

1990-08-10

187

Transforming vulnerability.  

PubMed

Asian American immigrant women engaged in filial caregiving are at special risk for health problems due to complex contextual factors related to immigration, cultural traditions, and role transition. This study examines the experience of two groups of immigrant Asian American women who are caring for older parents. A total of 41 women (22 Chinese American and 19 Filipino American) were interviewed in a study based on Strauss and Corbin's grounded theory methodology. The women were determined to be loyal to their traditional culture, which included strong filial values, while adapting to a new culture. Through the struggle of meeting role expectations and coping with paradox, the women mobilized personal and family resources to transform vulnerability into strength and well-being. PMID:14596182

Jones, Patricia S; Zhang, Xinwei Esther; Meleis, Afaf I

2003-11-01

188

Practical example of the correction of Fourier-transform spectra for detector nonlinearity.  

PubMed

HgCdTe photoconductive detectors can display a nonlinear response when illuminated. In interferometric applications, this behavior must be accounted for in the data transformation process to avoid errors in the measurement of the spectral distribution of the incident radiation. A model for the distortion of the interferogram is proposed and applied to solar observations made by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier-transform spectrometer during orbital sunrise and sunset from the Space Shuttle. Empirical estimation of the dc current level is necessary for this instrument, and satisfactory nonlinearity correction is obtained for several of the primary ATMOS optical filters. For ATMOS broadband optical filters that cover more than one half the alias bandwidth, the model is inadequate because of the presence of antialiasing electronic filters within the instrument, and it is necessary to resort to estimation and subtraction of the residual baseline offset. In either case the remaining base line offsets are typically smaller than 1%, which is satisfactory, although offset remains a significant systematic source of error in the estimation of the abundance of telluric and solar constituents from the spectra. PMID:20941162

Abrams, M C; Toon, G C; Schindler, R A

1994-09-20

189

The Fission Yeast Transforming Acidic Coiled Coil-related Protein Mia1p/Alp7p Is Required for Formation and Maintenance of Persistent Microtubule-organizing Centers at the Nuclear EnvelopeD?V?  

PubMed Central

Microtubule-organizing centers (MTOCs) concentrate microtubule nucleation, attachment and bundling factors and thus restrict formation of microtubule arrays in spatial and temporal manner. How MTOCs occur remains an exciting question in cell biology. Here, we show that the transforming acidic coiled coil–related protein Mia1p/Alp7p functions in emergence of large MTOCs in interphase fission yeast cells. We found that Mia1p was a microtubule-binding protein that preferentially localized to the minus ends of microtubules and was associated with the sites of microtubule attachment to the nuclear envelope. Cells lacking Mia1p exhibited less microtubule bundles. Microtubules could be nucleated and bundled but were frequently released from the nucleation sites in mia1? cells. Mia1p was required for stability of microtubule bundles and persistent use of nucleation sites both in interphase and postanaphase array dynamics. The ?-tubulin–rich material was not organized in large perinuclear or microtubule-associated structures in mia1? cells. Interestingly, absence of microtubules in dividing wild-type cells prevented appearance of large ?-tubulin–rich MTOC structures in daughters. When microtubule polymerization was allowed, MTOCs were efficiently assembled de novo. We propose a model where MTOC emergence is a self-organizing process requiring the continuous association of microtubules with nucleation sites. PMID:16481403

Zheng, Liling; Schwartz, Cindi; Wee, Liangmeng; Oliferenko, Snezhana

2006-01-01

190

EDITORIAL: Transformation optics Transformation optics  

NASA Astrophysics Data System (ADS)

Metamaterials are artificial materials with versatile properties that can be tailored to fit almost any practical need and thus go well beyond what can be obtained with `natural' materials. Recent progress in developing optical metamaterials allows unprecedented extreme control over the flow of light at both the nano- and macroscopic scales. The innovative field of transformation optics, which is enabled by metamaterials, inspired researchers to take a fresh look at the very foundations of optics and helped to create a new paradigm for the science of light. Similar to general relativity, where time and space are curved, transformation optics shows that the space for light can also be bent in an almost arbitrary way. Most importantly, the optical space can be designed and engineered, opening up the fascinating possibility of controlling the flow of light with nanometer spatial precision. This new paradigm enables a number of novel optical devices guiding how, using metamaterials, the space for light can be curved in a pre-designed and well-controlled way. Metamaterials which incorporate the innovative theories of transformation optics are pertinent to the important areas of optical cloaking, optical black holes, super-resolution imaging, and other sci-fi-like devices. One such exciting device is an electromagnetic cloak that can bend light around itself, similar to the flow of water around a stone, making invisible both the cloak and the object hidden inside. Another important application is a flat hyperlens that can magnify the nanometer-scale features of an object that cannot be resolved with conventional optics. This could revolutionize the field of optical imaging, for instance, because such a meta-lens could become a standard add-on tool for microscopes. By enabling nanoscale resolution in optical microscopy, metamaterial-based transformation optics could allow one to literally see extremely small objects with the eye, including biological cells, viruses, and possibly even DNA molecules. Light-concentrating devices, such as the optical black hole, can be used for efficient solar light collection in photovoltaic elements for renewable energy. With the dramatic advances in micro- and nanofabrication methods, we are presented with the opportunity to control light in a way that was not possible with the materials provided to us by nature. In an artificial pattern of sub-wavelength elements, the propagation of electromagnetic energy can be defined by an equivalent spatial and spectral dispersion of effective dielectric and magnetic properties. These synthetic structures, which can be fabricated with a desired spatial distribution of effective permittivity epsilon(r) and permeability ?(r), offer a unique potential to guide and control the flow of electromagnetic energy in such an engineered optical space. No longer are we constrained by the electromagnetic response of natural materials and their chemical compounds. Instead, we can tailor the shape and size of the structural units of the metamaterials, or tune their composition and morphology to provide new functionality.

Shalaev, Vladimir M.; Pendry, John

2011-02-01

191

Martensitic transformation in zirconia  

Microsoft Academic Search

Main characteristics of martensitic transformations in metals and alloys ; are described, and available data on the monoclinic-tetragonal transformation in ; ZrOâ are critically evaluated. Kinetics, thermal hysteresis, tetragonal -- ; cubic transformation, metastable high-temperature phases, and pressure and ; irradiationinduced transformation are discussed. Transformation in HfOâ is ; also briefly examined. (9 tables, 22 figures, 108 references) (DLC);

E. C. Subbarao; H. S. Maiti; K. K. Srivastava

1974-01-01

192

Analyzing Signals Fourier transform  

E-print Network

Page 1 1 Analyzing Signals Fourier transform s frequency content s linear combination of sin frequency analysis s windowed Fourier transform 6 #12;Page 4 7 Gabor Transform function to analyze window Gabor Transform Spatial domain Gabor domain b #12;Page 5 9 Gabor Transform Problems s discrete version

Sweldens, Wim

193

Classification of transforms  

NASA Astrophysics Data System (ADS)

Lindsey and Suter have shown that for many transforms the transform of the convolution of two functions have the same functional form. We explain the origin of this result and derive the condition on the transformation kernel for when this should be the case. In addition we consider the general transform of the inverse and direct scale transform and obtain condition on the kernel so that the transform gives similar functional forms.

Cohen, Leon; Lindsey, Alan R.; Suter, Bruce W.

2000-12-01

194

Heterospecific transformation among cyanobacteria.  

PubMed Central

Heterospecific transformation occurred between cyanobacteria currently classified in either the genus Synechococcus or Synechocystis. Cyanobacterial strains 73109 and 6906 were capable of physiological transformation. PMID:3091578

Stevens, S E; Porter, R D

1986-01-01

195

Hadamard transform image coding  

Microsoft Academic Search

The introduction of the fast Fourier transform algorithm has led to the development of the Fourier transform image coding technique whereby the two-dimensional Fourier transform of an image is transmitted over a channel rather than the image itself. This devlopement has further led to a related image coding technique in which an image is transformed by a Hadamard matrix operator.

W. K. Pratt; J. Kane; H. C. Andrews

1969-01-01

196

Glowing Bacteria: Transformation Efficiency  

E-print Network

took up and expressed GFP after transformation. Background: Transformation efficiency is a quantitative1 Glowing Bacteria: Transformation Efficiency Purpose: To determine how well your E. coli cells. The number represents how many cells were transformed per microgram (µg) of plasmid DNA used

Rose, Michael R.

197

Discrete Cosine Transform  

Microsoft Academic Search

A discrete cosine transform (DCT) is defined and an algorithm to compute it using the fast Fourier transform is developed. It is shown that the discrete cosine transform can be used in the area of digital processing for the purposes of pattern recognition and Wiener filtering. Its performance is compared with that of a class of orthogonal transforms and is

N. Ahmed; T. Natarajan; K. R. Rao

1974-01-01

198

Research on Lead Acid Battery Electrodes.  

National Technical Information Service (NTIS)

The reactions and physical and molecular transformations that occur in lead acid battery plate active material during charge-discharge cycling have been studied under a DOE program to improve the lead acid battery for electric vehicle applications. Invest...

A. C. Simon, S. M. Caulder, C. P. Wales, R. L. Jones

1982-01-01

199

Hydroxylation of dehydroabietic acid by Fusarium species.  

PubMed

A novel compound, 1 beta-hydroxydehydroabietic acid has been obtained by the microbial transformation of dehydroabietic acid, using cultures of Fusarium oxysporum and F. moniliforme. Its antibacterial activity was also tested. PMID:9276983

Tapia, A A; Vallejo, M D; Gouiric, S C; Feresin, G E; Rossomando, P C; Bustos, D A

1997-09-01

200

Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants  

DOEpatents

The present invention relates to a process for producing lipids containing the fatty acid petroselinic acid in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a .omega.12 desaturase from another species which does normally accumulate petroselinic acid.

Ohlrogge, John B. (Okemos, MI); Cahoon, Edgar B. (Lansing, MI); Shanklin, John (Upton, NY); Somerville, Christopher R. (Okemos, MI)

1995-01-01

201

Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants  

DOEpatents

The present invention relates to a process for producing lipids containing the fatty acid, petroselinic acid, in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a {omega}12 desaturase from another species which does normally accumulate petroselinic acid. 19 figs.

Ohlrogge, J.B.; Cahoon, E.B.; Shanklin, J.; Somerville, C.R.

1995-07-04

202

Transforming America's Energy Economy Transforming America's  

E-print Network

to ensure our energy security and to mitigate the environmental consequences associated with our current outlined in this white paper are driven by energy security and climate change concerns. Energy security#12;Transforming America's Energy Economy Transforming America's Energy Economy This document

203

Ursodeoxycholic acid, 7-ketolithocholic acid, and chenodeoxycholic acid are primary bile acids of the nutria (Myocastor coypus).  

PubMed

Because ursodeoxycholic and chenodeoxycholic acids are interconverted in humans via 7-ketolithocholic acid, bile acid metabolism was studied in the nutria (Myocastor coypus), the bile of which is known to contain these three bile acids. Relative concentrations of ursodeoxycholic (37% +/- 20%), 7-ketolithocholic (33% +/- 17%), and chenodeoxycholic (17% +/- 9%) acids in gallbladder bile were unchanged by 5-20 h of complete biliary diversion (n = 7). Injection of either [14C]cholesterol, [14C]ursodeoxycholic, [14C]7-ketolithocholic acid, or a mixture of [7 beta-3H]chenodeoxycholic acid and [14C]chenodeoxycholic acid into bile fistula nutria demonstrated that all three bile acids can be synthesized hepatically from cholesterol, that they are interconverted sparingly (2%-5%) by the liver, but that 7-ketolithocholic acid is an intermediate in the hepatic transformation of chenodeoxycholic acid to ursodeoxycholic acid. An animal that had been fed antibiotics showed an unusually elevated concentration of ursodeoxycholic acid in gallbladder and hepatic bile, suggesting that bacterial transformation of ursodeoxycholic acid in the intestine may be a source of some biliary chenodeoxycholic acid and 7-ketolithocholic acid. PMID:3943698

Tint, G S; Bullock, J; Batta, A K; Shefer, S; Salen, G

1986-03-01

204

Equations For Rotary Transformers  

NASA Technical Reports Server (NTRS)

Equations derived for input impedance, input power, and ratio of secondary current to primary current of rotary transformer. Used for quick analysis of transformer designs. Circuit model commonly used in textbooks on theory of ac circuits.

Salomon, Phil M.; Wiktor, Peter J.; Marchetto, Carl A.

1988-01-01

205

Solid State Power Transformer.  

National Technical Information Service (NTIS)

Apparatus for providing the voltage transformation functions of a conventional electrical power transformer. An AC input signal is chopped in a solid state switching converter at a frequency very much larger than the frequency of the input signal and then...

J. L. Brooks, R. I. Staab, J. C. Bowers, H. A. Nienhaus

1980-01-01

206

Landscapes of transformation  

E-print Network

This thesis aims to examine the cultural effect of transformation through the lens of procedural techniques applied to the human body and architecture. The body and architecture both operate as landscapes of transformation. ...

Ambs, Emily (Emily Kiersten)

2007-01-01

207

Metrics for enterprise transformation  

E-print Network

The objective of this thesis is to depict the role of metrics in the evolving journey of enterprise transformation. To this end, three propositions are explored: (i) metrics and measurement systems drive transformation, ...

Blackburn, Craig D. (Craig David), S. M. Massachusetts Institute of Technology

2009-01-01

208

Power electronics traction transformer  

Microsoft Academic Search

With the new generation of full low floor passenger trains, the constraints of weight and size on the traction transformer are becoming stronger. The ultimate target weight for the transformer is 1 kg\\/kVA. The reliability and the efficiency are also becoming more important. To address these issues, a multilevel topology using medium frequency transformers has been developed. It permits to

Nicolas Hugo; Philippe Stefanutti; Marc Pellerin; Alper Akdag

2007-01-01

209

Review article Genetic transformation  

E-print Network

Review article Genetic transformation: a short review of methods and their applications, results of phenotypic traits has been examined. Agrobacterium I biotechnology I forest tree I genetic transformation Biotechnology includes tissue culture, mo- lecular biology and genetic transformation. This field of research

Paris-Sud XI, Université de

210

The pulse sorting transform  

Microsoft Academic Search

A modification of conventional Fourier transforms is presented. This modification is called the pulse sorting transform (PST) and is useful in extracting information from signals comprised of interleaved pulse trains. A brief derivation of the PST from the conventional transform is presented, followed by theorems that describe the PST's properties. Several examples of how the PST can be an effective

K. C. Overman; D. F. Mix; J. A. Lookadoo

1990-01-01

211

Transforming Anxiety into ENERGYTM  

E-print Network

Transforming Anxiety into ENERGYTM How to Prevent Panic and Promote Productivity in Turbulent Times By Wendy Mack with contributions from Meredith Kimbell and Myron Radio #12;Transforming Anxiety into Energy, consultants, and researchers who shared their stories and expertise. 1 #12;Transforming Anxiety into Energy

Maryland, Baltimore County, University of

212

Note: Tesla transformer damping.  

PubMed

Unexpected heavy damping in the two winding Tesla pulse transformer is shown to be due to small primary inductances. A small primary inductance is a necessary condition of operability, but is also a refractory inefficiency. A 30% performance loss is demonstrated using a typical "spiral strip" transformer. The loss is investigated by examining damping terms added to the transformer's governing equations. A significant alteration of the transformer's architecture is suggested to mitigate these losses. Experimental and simulated data comparing the 2 and 3 winding transformers are cited to support the suggestion. PMID:22852736

Reed, J L

2012-07-01

213

[Studies on interaction of acid-treated nanotube titanic acid and amino acids].  

PubMed

Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination. PMID:20649031

Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

2010-06-01

214

Acid rain: facts and fallacies  

Microsoft Academic Search

Acid rain is a complex environmental problem that is hard to define in terms of sources and effects. Major sources are thought to be atmospheric emissions, mostly from urban sources, although exact locations and the means by which emissions are transformed to acid rain are not entirely clear. Lack of long-term records has made it difficult to determine how fast

1981-01-01

215

[Natural transformation in bacteria].  

PubMed

Transformants may be formed by some bacterial species when the growing cultures are mixed. This phenomenon caused by the DNA release from bacterial cells is called natural transformation. DNA release is most likely to be mediated by cell autolysis. Both chromosomal markers and plasmids are transferred by natural transformation. The phenomenon is reproduced while growing bacteria together in sterile soil. The DNA adsorbed on sand and other soil solid particles was more resistant to DNAse action, than the free transforming DNA. Natural transformation seems to be one of the forms of the genetic exchange in bacteria in their habitats. An indirect argument for this suggestion is perfect coordination between the different steps of transformation process, at least, in some bacterial species. PMID:2185417

Kosovich, P V; Prozorov, A A

1990-01-01

216

Nanosecond Pulse Transformers  

Microsoft Academic Search

The transmission-line approach to the design of transformers yields a unit with no first-order rise-time limit since this approach uses distributed rather than lumped constants. The total time delay through the transmission-line-type transformer may exceed the rise time by a large factor, unlike conventional transformers. The extra winding length can be employed to improve the low-frequency response of the unit.

C. Norman Winningstad

1959-01-01

217

Magnetically Controlled Variable Transformer  

NASA Technical Reports Server (NTRS)

Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

Kleiner, Charles T.

1994-01-01

218

Program Transformation in HATS  

SciTech Connect

HATS is a general purpose syntax derivation tree based transformation system in which transformation sequences are described in special purpose language. A powerful feature of this language is that unification is an explicit operation. By making unification explicit, an elegant framework arises in which to express complex application conditions which in turn enables refined control strategies to be realized. This paper gives an overview of HATS, focusing especially on the framework provided by the transformation language and its potential with respect to control and general purpose transformation.

Winter, V.L.

1999-02-24

219

Transformation Market Transformation is based on  

E-print Network

and reducing high insurance costs. Strategies Market Transformation's primary goal is to accelerate-powered lift trucks. When compared to typical battery-powered units, fuel cell lift trucks provide 80% lower collection and analysis by the National Renewable Energy Laboratory.1 Fuel cell-powered lift trucks offer

220

Disc piezoelectric ceramic transformers.  

PubMed

In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 ? to 10 k?, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power. PMID:25004532

Erhart, Jirií; P?lpán, Petr; Dole?ek, Roman; Psota, Pavel; Lédl, Vít

2013-08-01

221

Biochemical transformation of coals  

DOEpatents

A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed. 7 figs.

Lin, M.S.; Premuzic, E.T.

1999-03-23

222

Biochemical transformation of coals  

DOEpatents

A method of biochemically transforming macromolecular compounds found in solid carbonaceous materials, such as coal is provided. The preparation of new microorganisms, metabolically weaned through challenge growth processes to biochemically transform solid carbonaceous materials at extreme temperatures, pressures, pH, salt and toxic metal concentrations is also disclosed.

Lin, Mow S. (Rocky Point, NY); Premuzic, Eugene T. (East Moriches, NY)

1999-03-23

223

Optical source transformations.  

PubMed

Transformation optics is a recently appreciated methodology for the design of complex media that control the propagation of electromagnetic and other types of waves. The transformation optical technique involves the use of coordinate transformations applied to some region of space, providing a conceptual means to redirect the flow of waves. Successfully designed devices to date have made use of transformations acting on passive space only; however, the technique can also be applied when source distributions (e.g., current and charge) are included within the space being transformed. In this paper we present examples of source transformations that illustrate the potential of these expanded transformation optical methods. In particular, using finite-element full-wave simulations, we confirm the restoration of dipole radiation patterns from both a distorted 'pin-wheel' antenna and a bent dipole partially occluded by a cylindrical scatterer. We propose the technique of source transformations as a powerful approach for antenna design, especially in relation to conformal antennas. PMID:19104551

Kundtz, N; Roberts, D A; Allen, J; Cummer, S; Smith, D R

2008-12-22

224

Fourier Transform Spectrometer  

NASA Technical Reports Server (NTRS)

Understanding the global atmospheric changes is difficult with today's current technology. However, with high resolution and nearly continuous observations from a satellite, it's possible to transform our understanding of the atmosphere. To enable the next generation of atmospheric science, a new class of orbiting atmospheric sensors is being developed. The foundation of this advanced concept is the Fourier Transform Spectrometer, or FTS.

1998-01-01

225

Transforming Dentistry through Innovation  

E-print Network

7 Transforming Dentistry through Innovation and Imagination Research Matters Faculty Highlights's practitioners and researchers through... DentistryF A C U L T Y O F TRANSFORMING DENTISTRY THROUGH INNOVATION a short time ago, were not possible. Naturally, these changes are influencing the teaching of dentistry

Barthelat, Francois

226

Deployment & Market Transformation (Brochure)  

SciTech Connect

NREL's deployment and market transformation (D and MT) activities encompass the laboratory's full range of technologies, which span the energy efficiency and renewable energy spectrum. NREL staff educates partners on how they can advance sustainable energy applications and also provides clients with best practices for reducing barriers to innovation and market transformation.

Not Available

2012-04-01

227

Transform picture coding  

Microsoft Academic Search

Picture coding by first dividing the picture into sub-pictures and then performing a linear transformation on each sub-picture cud quantizing and coding the resulting coefficients is introduced from a heuristic point of view. Various transformation, quantization, and coding strategies are discussed. A survey of all known applications of these techniques to monochromatic image coding is presented along with a summary

P. A. Wintz

1972-01-01

228

Transforming convolution and correlation  

NASA Astrophysics Data System (ADS)

We give an explicit expression for the transform of a signal in an arbitrary representation which has first been filtered in another representation. Using this formula we connect the work of Cohen for obtaining convolution and correlation theorems in arbitrary representations with the work of Lindsey and Suter for partitioning the space of integral transforms.

Cohen, Leon; Lindsey, Alan R.; Suter, Bruce W.

2001-12-01

229

Support Principals, Transform Schools  

ERIC Educational Resources Information Center

The Transformational Coaching Team in Oakland Unified School District provides differentiated, sustained, job-embedded support to the district's school leaders. In this article, members of the team describe how they work with principals to transform the culture of schools. Student achievement data show above-average improvement in schools in which…

Aguilar, Elena; Goldwasser, Davina; Tank-Crestetto, Kristina

2011-01-01

230

Transformations Using Technology  

NSDL National Science Digital Library

The teacher can introduce the website and demonstrate the use of commands to translate, rotate, or reflect. A series of transformations can be explored to result in a specified final image. Students can then access the site and use the tool to explore transformations.

Interactivate (Shodor)

2010-03-04

231

Reconstructing finite radon transforms  

NASA Astrophysics Data System (ADS)

Reconstructing finite Radon transforms is equivalent to inverting incidence matrices, that is, matrices whose entries are zeroes or ones. We describe several methods of reconstructing Radon transforms on combinatorial structures which may be useful in statistical mechanics. Amongst these structures are experimental designs, translates of subsets in finite groups, nearest neighborhoods in grids, geometric lattices, matroids, and modular lattices.

Kung, Joseph P. S.

1988-09-01

232

Transformer ratio enhancement experiment  

Microsoft Academic Search

Recently, a multibunch scheme for efficient acceleration based on dielectric wakefield accelerator technology was outlined in ref.[1]. In this paper we present an experimental program for the design, development and demonstration of an Enhanced Transformer Ratio Dielectric Wakefield Accelerator (ETR-DWA). The principal goal is to increase the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the

A. Kanareykin; Wei Gai; J. G. Power; E. Nenasheva; A. Altmark

2003-01-01

233

CST: C state transformers  

Microsoft Academic Search

C State transformers (CST) is an expression ori- ented dialect of C designed to smoothly integrate functional programming into C based software. C State Transformers is an attempt to do for functional programming what C++ did for object oriented pro- gramming. It provides support for functional pro- gramming with a C like syntax.

John D. Ramsdell

1995-01-01

234

Transforming Health Research  

E-print Network

Transforming Health Research the first two years National Institute for Health Research Progress For Information R OCR R ef: 0 Gateway R ef: 9298 Title Transforming Health Research the first two years. Health Research Progress Report 2006-2008 National Institute for Author National Institute for Health Research

Diggle, Peter J.

235

Transformation of Anaplasma phagocytophilum  

Microsoft Academic Search

BACKGROUND: Tick-borne pathogens cause emerging zoonoses, and include fastidious organisms such as Anaplasma phagocytophilum. Because of their obligate intracellular nature, methods for mutagenesis and transformation have not been available. RESULTS: To facilitate genetic manipulation, we transformed A. phagocytophilum (Ap) to express a green fluorescent protein (GFP) with the Himar1 transposase system and selection with the clinically irrelevant antibiotic spectinomycin. CONCLUSION:

Roderick F Felsheim; Michael J Herron; Curtis M Nelson; Nicole Y Burkhardt; Anthony F Barbet; Timothy J Kurtti; Ulrike G Munderloh

2006-01-01

236

Genetic Transformation of Bacteria.  

ERIC Educational Resources Information Center

An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)

Moss, Robert.

1991-01-01

237

The Discrete Pulse Transform  

Microsoft Academic Search

We investigate a recent algorithm, here called a discrete pulse transform (DPT), for the multiresolution analysis of a sequence. A DPT represents a sequence as a sum of pulses, where a pulse is a sequence which is zero everywhere except for a certain number of consecutive elements which have a constant nonzero value. Unlike the discrete Fourier and wavelet transforms,

C. H. Rohwer; D. P. Laurie

2006-01-01

238

Transformation optics and metamaterials.  

PubMed

Underpinned by the advent of metamaterials, transformation optics offers great versatility for controlling electromagnetic waves to create materials with specially designed properties. Here we review the potential of transformation optics to create functionalities in which the optical properties can be designed almost at will. This approach can be used to engineer various optical illusion effects, such as the invisibility cloak. PMID:20414221

Chen, Huanyang; Chan, C T; Sheng, Ping

2010-05-01

239

Genetic transformation in citrus.  

PubMed

Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species. PMID:23983635

Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Kacar, Yildiz Aka; Mendi, Yesim Yalcin

2013-01-01

240

Genetic Transformation in Citrus  

PubMed Central

Citrus is one of the world's important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species. PMID:23983635

Donmez, Dicle; Simsek, Ozhan; Izgu, Tolga; Aka Kacar, Yildiz; Yalcin Mendi, Yesim

2013-01-01

241

The martensitic transformation in ceramics — its role in transformation toughening  

Microsoft Academic Search

This paper reviews the current knowledge and understanding of martensitic transformations in ceramics — the tetragonal to monoclinic transformation in zirconia in particular. This martensitic transformation is the key to transformation toughening in zirconia ceramics. A very considerable body of experimental data on the characteristics of this transformation is now available. In addition, theoretical predictions can be made using the phenomenological

Patrick M. Kelly; L. R. Francis Rose

2002-01-01

242

Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells  

PubMed Central

Background Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase) has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. Methods The present study is to examine the effect of 3-acetyl-11-keto-?-boswellic acids (AKBA), a potent boswellic acid, on acid SMase activity and expression in intestinal cells. Both transformed Caco-2 cells and non-transformed Int407 cells were incubated with AKBA. After incubation, the change of acid SMase activity was assayed biochemically, the enzyme protein was examined by Western blot, and acid SMase mRNA was quantified by qPCR. Results We found that AKBA decreased acid SMase activity in both intestinal cell lines in dose and time dependent manners without affecting the secretion of the enzyme to the cell culture medium. The effect of AKBA was more effective in the fetal bovine serum-free culture medium. Among different types of boswellic acid, AKBA was the most potent one. The inhibitory effect on acid SMase activity occurred only in the intact cells but not in cell-free extract in the test tubes. At low concentration, AKBA only decreased the acid SMase activity but not the quantity of the enzyme protein. However, at high concentration, AKBA decreased both the mass of acid SMase protein and the mRNA levels of acid SMase in the cells, as demonstrated by Western blot and qPCR, respectively. Under the concentrations decreasing acid SMase activity, AKBA significantly inhibited cell proliferation. Conclusion We identified a novel inhibitory effect of boswellic acids on acid SMase expression, which may have implications in human diseases and health. PMID:19951413

2009-01-01

243

Sonolysis of Short-Chain Organic Dicarboxylic Acid Solutions  

NASA Astrophysics Data System (ADS)

Sonolyses of C4 (carbon number 4) dicarboxylic acids (succinic acid, maleic acid, and fumaric acid) were performed in aqueous solution. They changed one into the other during sonication, affording carbon-number-conserving transformations. Maleic acid and fumaric acid were produced from saccinic acid by dehydrogenation. Furthermore, malic acid and tartaric acid were obtained by hydroxylation. The sonochemical reaction processes are discussed in terms of the time dependences of products and the addition of radical scavengers. In addition, mutual isomerization of fumaric acid and maleic acid was observed during sonication without the use of mediators.

Naruke, Yukio; Harada, Hisashi

2011-07-01

244

Special Relativity and Diagonal Transformations  

Microsoft Academic Search

We discuss the form of the special Lorentz transformation, and the corresponding transformation of the electromagnetic field, in which the transformation matrix is diagonal. We derive the diagonal form of the special Lorentz transformation directly, in a simple way, and show that it is sometimes more convenient to apply than the algebraically equivalent conventional form of the transformation. The convenience

Leonard Parker; Glenn M. Schmieg

1970-01-01

245

Properties of the Fourier Transform  

E-print Network

Properties of the Fourier Transform 24.2 Introduction ' & $ % Prerequisites Before starting to . . . #12;1. Linearity Properties of the Fourier Transform (i) If f(t), g(t) are functions with transforms F Transform of the resulting function is simply the sum of the individual Fourier Transforms. (ii) If k is any

Vickers, James

246

The Practice of Transformative Pedagogy  

ERIC Educational Resources Information Center

The author examined the practice of transformative pedagogy in an undergraduate teacher education program. The research was guided by two questions: What is the impact of transformative pedagogy on fostering preservice teachers' transformative learning? and What practices of transformative pedagogy impact student transformative learning?…

Ukpokodu, Omiunota

2009-01-01

247

Information under Lorentz transformation  

E-print Network

A general form of a two-qubit system is obtained under the effect of Lorentz transformation. We investigate extensively some important classes in the context of quantum information. It is shown Lorentz transformation causes a decay of entanglement and consequently information loses. On the other hand, it generates entangled states between systems prepared initially in a separable states. The partial entangled states are more robust under Lorentz transformation than maximally entangled states. Therefore the rate of information lose is larger for maximum entangled states compared with that for partially entangled states.

N. Metwally; H. Eleuch; M. Abdel-Aty

2014-02-11

248

A cascade of artificial neural networks to predict transformers oil parameters  

Microsoft Academic Search

In this paper artificial neural networks have been constructed to predict different transformers oil parameters. The prediction is performed through modeling the relationship between the insulation resistance measured between distribution transformers high voltage winding, low voltage winding and the ground and the breakdown strength, interfacial tension acidity and the water content of the transformers oil. The process of predicting these

Khaled Shaban; Ayman El-Hag; Andrei Matveev

2009-01-01

249

Imaging Fourier transform spectrometer  

SciTech Connect

This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.

Bennett, C.L.

1993-09-13

250

Applying Improved Efficiency Transformers  

E-print Network

Today's business and energy conscious environment affords both producers and consumers of electric energy an opportunity to reduce costs and conserve energy through the use of improved efficiency transformers. Various design techniques...

Haggerty, N. K.; Malone, T. P.

251

Technique for lymphocyte transformation  

PubMed Central

Current techniques for lymphocyte transformation are evaluated and criticised. A simple technique, designed to meet these criticisms, is described in detail, with particular reference to lymphocyte separation and scoring methods. PMID:5697050

Pentycross, C. R.

1968-01-01

252

Fourier Transform Mass Spectrometry  

PubMed Central

This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook. PMID:21742802

Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

2011-01-01

253

Transformation inverse design  

E-print Network

We present a new technique for the design of transformation-optics devices based on large-scale optimization to achieve the optimal effective isotropic dielectric materials within prescribed index bounds, which is ...

Liu, David

254

Transformation: Women and Mathematics.  

ERIC Educational Resources Information Center

Discusses the transformation of women and mathematics and the papers contained in this special issue. Questions whether women are changed by mathematics or if mathematics can and is being changed by them. (MKR)

John-Steiner, Vera

1996-01-01

255

Cloning a Plant Amino Acid Transporter by Functional Complementation of a Yeast Amino Acid Transport Mutant  

Microsoft Academic Search

Amino acids are transported across the plasma membrane of plant cells by proton-amino acid symports. We report here the successful cloning of a neutral amino acid carrier by functional complementation. A histidine transport deletion mutant of Saccharomyces cerevisiae was transformed with an Arabidopsis thaliana cDNA library constructed in a yeast expression vector. Forty transformants, out of 10^5, allowed growth on

Li-Chu Hsu; Tzyy-Jen Chiou; Lishan Chen; Daniel R. Bush

1993-01-01

256

Series Transmission Line Transformer  

SciTech Connect

A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

Buckles, Robert A. (Livermore, CA); Booth, Rex (Livermore, CA); Yen, Boris T. (El Cerrito, CA)

2004-06-29

257

Service Enterprise Transformation  

Microsoft Academic Search

\\u000a This chapter examines the challenges in transforming a complex multi-organisational service enterprise. It builds on a review\\u000a of relevant literature and an empirical analysis of the early experience and lessons learned by industry and MoD partners\\u000a in the ATTAC (ATTAC (Availability Transformation: Tornado Aircraft Contract) is a long-term, whole-aircraft availability contract\\u000a where BAE Systems take prime responsibility to provide Tornado

Valerie Purchase; Glenn Parry; John Mills

258

Finite-Field Wavelet Transforms  

Microsoft Academic Search

Cyclic wavelet transforms, analogous to cyclic Fourier transforms, are described. Among other things, this construction allows for the development of wavelet transforms over finite fields. Potential applications of this construct in algebraic coding are discussed.

H. Vincent Poor

1995-01-01

259

Floral Transformation of Wheat  

NASA Astrophysics Data System (ADS)

A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

260

Transformation superplasticity of zirconium  

SciTech Connect

A tensile strain of 270% was achieved for coarse-grained zirconium subjected to transformation superplasticity condition, where strain increments are accumulated upon repeated thermal cycling around the allotropic transformation temperature under the biasing effect of a uniaxial tensile stress. The strain increment per cycle was found to consist of two equal contributions from transformations on heating and cooling and to increase linearly with the applied stress. The measured strain increments are in good quantitative agreement with predictions based on the average internal stress during the transformation, which was determined independently from experimental transformation times. As the cycling frequency is raised, the average strain rate increases (a maximum value of 1.3 {times} 10{sup {minus}4} s{sup {minus}1} was measured), but the strain increment per cycle decreases above a critical cycling frequency, for which the sample gage section undergoes only a partial phase transformation. The resulting reduction in internal mismatch and increase in internal stress are modeled using the experimental observation that {beta}-Zr deforms by a mixture of diffusional and dislocation creep in the stress range of interest.

Zwigl, P. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering; Dunand, D.C. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering

1998-10-01

261

A FURTHER EVALUATION OF MICROCOULOMETRY FOR ATMOSPHERIC NITRIC ACID MONITORING  

EPA Science Inventory

A coulometric instrument for measuring gaseous nitric acid is modified to improve response time characteristics and simplify operation. Possible interferences were investigated and found minimal. Comparison measurements of nitric acid by long path Fourier Transform infrared analy...

262

Effect of the amino chain length and the transformation into citric acid salts of aryl-diphenyl-butenes and ferrocenyl-diphenyl-butenes bearing two dimethylaminoalkyl chains on their antimicrobial activities.  

PubMed

In a previous work we have demonstrated the antimicrobial activity of ferrocenyl or phenyl derivatives of diphenyl butene series. This finding has opened a new area of applications of organometallic compounds. In order to improve these activities, we have synthesized new organic and organometallic diaryl butene compounds with different lengths of their amino chains. These new compounds, and also their ammonium salts, were tested against man pathogenic microorganisms Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442), Staphylococcus aureus (ATCC 6538) and Enterococcus hirae (ATCC 10541). It emerged from the tests that the Gram+ bacteria are more sensitive to the compounds than Gram-, and the compounds with 3 carbon amino chains have a better antimicrobial activity than the one having a chain of 2 or 4 carbons. The transformation of compounds to citrate salts was accompanied by a significant regression of antibacterial activity against Pseudomonas aeruginosa, for both organic and ferrocenic molecules. This resistance problem has been solved using hydrochlorides salts rather than citrates one. PMID:24133651

Jellali, Karim; Pigeon, Pascal; Trigui, Fatma; Top, Siden; Aifa, Sami; Jaouen, Gérard; El Arbi, Mehdi

2013-01-01

263

Canonical Transformations in Quantum Mechanics  

E-print Network

Quantum canonical transformations are defined algebraically outside of a Hilbert space context. This generalizes the quantum canonical transformations of Weyl and Dirac to include non-unitary transformations. The importance of non-unitary transformations for constructing solutions of the Schr\\"odinger equation is discussed. Three elementary canonical transformations are shown both to have quantum implementations as finite transformations and to generate, classically and infinitesimally, the full canonical algebra. A general canonical transformation can be realized quantum mechanically as a product of these transformations. Each transformation corresponds to a familiar tool used in solving differential equations, and the procedure of solving a differential equation is systematized by the use of the canonical transformations. Several examples are done to illustrate the use of the canonical transformations. [This is an extensively revised version of hep-th-9205080: the first third of the paper is new material; the notation has been simplified, and further discussion has been added to the remainder.

Arlen Anderson

1993-05-13

264

Amide Bond Formation via Reversible, Carboxylic Acid-Promoted Lactone Aminolysis  

E-print Network

A rapid carboxylic acid-promoted lactone aminolysis is reported. A number of carboxylic acids were found to promote this amide bond-forming transformation, with aliphatic acids being the most efficient. This reaction is ...

Foley, Megan A.

265

Transformation Nets -A Runtime Model for Transformation Languages  

E-print Network

transformation languages relieve trans- formation designers from these burdens, specification of transformation to the information provided by the transformation engine, most often just consist- ing of variable values and logging messages, but missing important information e.g., why certain parts of a transformation are actually

Hochreiter, Sepp

266

TRANSFORMATIVE LEARNING THEORY: LEARNING BY TRANSFORMING AND CHANGING  

Microsoft Academic Search

In this manuscript, Mezirow’s transformative learning theory is studied. In this context, the definition, dimensions of transformative learning, the roles of teachers and learners in transformative learning and its curricular scopes are analyzed. In the study held as analyses of the literature, the following results are reached: Transformative learning theory is formed with a synthesis of critical reflection and hermeneutics.

Burhan Akpinar

2010-01-01

267

Dendrimer-enabled transformation of Chlamydia trachomatis.  

PubMed

Lack of a system for genetic manipulation of Chlamydia trachomatis has been a key challenge to advancing understanding the molecular genetic basis of virulence for this bacterial pathogen. We developed a non-viral, dendrimer-enabled system for transformation of this organism and used it to characterize the effects of inserting the common 7.5 kbp chlamydial plasmid into strain L2(25667R), a C. trachomatis isolate lacking it. The plasmid was cloned in pUC19 and the clone complexed to polyamidoamine dendrimers, producing ?83 nm spherical particles. Nearly confluent McCoy cell cultures were infected with L2(25667R) and reference strain L2(434). At 16 h post-infection, medium was replaced with dendrimer-plasmid complexes in medium lacking additives (L2(25667R)) or with additive-free medium alone (L2(434)). Three h later complexes/buffer were removed, and medium was replaced; cultures were harvested at various times post-transformation for analyses. Real time PCR and RT-PCR of nucleic acids from transformed cultures demonstrated plasmid replication and gene expression. A previous report indicated that one or more plasmid-encoded product govern(s) transcription of the glycogen synthase gene (glgA) in standard strains. In L2(25667R) the gene is not expressed, but transformants of that strain given the cloned chlamydial plasmid increase glgA expression, as does L2(434). The cloned plasmid is retained, replicated, and expressed in transformants over at least 5 passages, and GFP is expressed when transformed into growing L2(25667R). This transformation system will allow study of chlamydial gene function in pathogenesis. PMID:24075820

Kannan, Rangaramanujam M; Gérard, Hérve C; Mishra, Manoj K; Mao, Guangzhao; Wang, Sunxi; Hali, Mirabela; Whittum-Hudson, Judith A; Hudson, Alan P

2013-12-01

268

Indium(III)-catalyzed reductive bromination and iodination of carboxylic acids to alkyl bromides and iodides: scope, mechanism, and one-pot transformation to alkyl halides and amine derivatives.  

PubMed

Highly effective indium(III)-catalyzed reductive bromination or iodination of a variety of carboxylic acids with 1,1,3,3-tetramethyldisiloxane (TMDS) and a source of bromine or iodine is described. This functional group interconversion has high tolerance for several functional groups, such as halogens, a hydroxy group, a nitro group, an olefin part, and a sulfide moiety. This indium catalytic system is also applicable to the reductive iodination of aldehyded, acyl chlorides, and esters. Furthermore, this reducing system can be applied to the one-pot synthesis of alkyl halides and amine derivatives via the addition of nucleophiles. Insight into the reaction mechanism was gained via the time course of (1)H and (13)C NMR monitoring experiments and the corresponding stepwise reactions. PMID:24087920

Moriya, Toshimitsu; Yoneda, Shinichiro; Kawana, Keita; Ikeda, Reiko; Konakahara, Takeo; Sakai, Norio

2013-11-01

269

New graft copolymers of hyaluronic acid and polylactic acid: Synthesis and characterization  

Microsoft Academic Search

New graft copolymers have been synthesized, using hyaluronic acid (HA) as a hydrophilic backbone and polylactic acid (PLA) as an aliphatic polyester in order to obtain new polymeric derivatives of HA able to hydrophobically associate in an aqueous medium. Hyaluronic acid with low molecular weight was made soluble in organic solvent by transformation to its tetrabutylammonium (TBA) salt. Using the

Fabio Salvatore Palumbo; Giovanna Pitarresi; Delia Mandracchia; Giuseppe Tripodo; Gaetano Giammona

2006-01-01

270

Transformation inverse design.  

PubMed

We present a new technique for the design of transformation-optics devices based on large-scale optimization to achieve the optimal effective isotropic dielectric materials within prescribed index bounds, which is computationally cheap because transformation optics circumvents the need to solve Maxwell's equations at each step. We apply this technique to the design of multimode waveguide bends (realized experimentally in a previous paper) and mode squeezers, in which all modes are transported equally without scattering. In addition to the optimization, a key point is the identification of the correct boundary conditions to ensure reflectionless coupling to untransformed regions while allowing maximum flexibility in the optimization. Many previous authors in transformation optics used a certain kind of quasiconformal map which overconstrained the problem by requiring that the entire boundary shape be specified a priori while at the same time underconstraining the problem by employing "slipping" boundary conditions that permit unwanted interface reflections. PMID:23787612

Liu, David; Gabrielli, Lucas H; Lipson, Michal; Johnson, Steven G

2013-06-17

271

Plastid transformation in eggplant.  

PubMed

Eggplant (Solanum melongena L.) is an important vegetable crop of tropical and temperate regions of the world. Here we describe a procedure for eggplant plastid transformation, which involves preparation of explants, biolistic delivery of plastid transformation vector into green stem segments, selection procedure, and identification of the transplastomic plants. Shoot buds appear from cut ends of the stem explants following 5-6 weeks of spectinomycin selection after bombardment with the plastid transformation vector containing aadA gene as selectable marker. Transplastomic lines are obtained after the regenerated shoots are subjected to several rounds of spectinomycin selection over a period of 9 weeks. Homoplasmic transplastomic lines are further confirmed by spectinomycin and streptomycin double selection. The transplastomic technology development in this plant species will open up exciting possibilities for improving crop performance, metabolic engineering, and the use of plants as factories for producing biopharmaceuticals. PMID:24599862

Bansal, Kailash C; Singh, Ajay K

2014-01-01

272

The amino acid composition of mammalian and bacterial cells  

Microsoft Academic Search

Summary High performance liquid chromatography was used to analyze the amino acid composition of cells. A total of 17 amino acids was analyzed. This method was used to compare the amino acid compositions of the following combinations: primary culture and established cells, normal and transformed cells, mammalian and bacterial cells, andEscherichia coli andStaphylococcus aureus. The amino acid compositions of mammalian

T. Okayasu; M. Ikeda; K. Akimoto; K. Sorimachi

1997-01-01

273

Fourier Transform Infrared (FTIR) Spectroscopy  

E-print Network

Fourier Transform Infrared (FTIR) Spectroscopy Klaus Gerwert, Lehrstuhl fu¨r Biophysik, Ruhr Transform IR by Johannes Orphal. Fourier transform infrared (FTIR) spectroscopy is an experimental technique. Introduction The underlying principle of a Fourier transform infrared (FTIR) spectrometer is the separation

Gerwert, Klaus

274

The discrete fractional Fourier transform  

Microsoft Academic Search

We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes the continuous ordinary Fourier transform. This definition is based on a particular set of eigenvectors of the DFT matrix, which constitutes the discrete counterpart of the set of Hermite-Gaussian functions.

Çagatay Candan; M. Alper Kutay; Haldun M. Ozaktas

2000-01-01

275

Discrete Fourier Transform Javier Montoya  

E-print Network

Discrete Fourier Transform Javier Montoya Photogrammetry and Remote Sensing ETH Zurich March 16, 2012 1 Introduction The Discrete form of the Fourier transform is known as Discrete Fourier Transform domain using the Inverse Discrete Fourier Transform (IDFT): f(x) = 1 N N-1 x=0 F(u)ej 2 N ux for u = 0, 1

Giger, Christine

276

Building an evolution transformation library  

Microsoft Academic Search

We have been developing knowledge-based tools to support the evolutionary development of specifications. Evolution is accomplished by means of evolution transformations, which are meaning-changing transformations applied to formal specifications. A sizable library of evolution transformations has been developed for our specification language, Gist. This paper assesses the results of our previous work on evolution transformations. It then describes our current

W. Lewis Johnson; Martin S. Feather

1990-01-01

277

Microbial transformation of (+)-adrenosterone.  

PubMed

The microbial transformation of (+)-adrenosterone (1) by Cephalosporium aphidicola afforded three metabolites identified as androsta-1,4-diene-3,11,17-trione (2), 17beta-hydroxyandrost-4-ene-3,11-dione (3) and 17beta-hydroxyandrosta-1,4-diene-3,11-dione (4). The fermentation of 1 with Fusarium lini also produced metabolites 2 and 4, while the fermentation with Trichothecium roseum afforded metabolite 3. The structures of transformed products were determined by spectroscopic methods. PMID:12434991

Musharraf, S Ghulam; Atta-Ur-Rahman; Choudhary, M Iqbal; Sultan, Sadia

2002-10-01

278

Optical Haar wavelet transform  

NASA Astrophysics Data System (ADS)

An optical Haar mother wavelet is created with a SEMETEX 128 X 128 magneto-optic spatial light modulator. Two techniques for dilating the mother wavelet are explored: (1) aperture stopping and (2) operating the SLM in ternary phase-amplitude mode. Discrete resolution levels of a continuous wavelet transform are obtained by optically correlating a binarized image with multiple dilations of the mother wavelet. Frequency-plane masks for the correlation process are generated suing thermoplastic holography. Experimental results are compared with a digital simulation of the wavelet transform.

Burns, Thomas J.; Fielding, Kenneth H.; Rogers, Steven K.; Pinski, Steven D.; Ruck, Dennis W.

1992-09-01

279

Plastid transformation in soybean.  

PubMed

The biotechnological potential of plastid genetic engineering has been illustrated in a limited number of higher plant species. We have developed a reproducible method to generate plastid transformants in soybean (Glycine max), a crop of major agronomic importance. The transformation vectors are delivered to embryogenic cultures by the particle gun method and selection performed using the aadA antibiotic resistance gene. Homoplasmy is established rapidly in the selected events without the need for further selection or regeneration cycles, and genes of interest can be expressed at a high level in green tissues. This is a significant step toward the commercial application of this technology. PMID:24599865

Dubald, Manuel; Tissot, Ghislaine; Pelissier, Bernard

2014-01-01

280

Conjugated Fatty Acid Synthesis  

PubMed Central

Conjugated linolenic acids (CLNs), 18:3 ?9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 ?9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 ?9cis,11trans,13cis) or ?-eleostearic acid (18:3 ?9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly ?-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of ?-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

2012-01-01

281

Inhibition of invasion in vitro and stimulation of aggregation by 13-cis retinoic acid correlates with the clustering of N-CAM in c-Ha-ras transformed glial cells.  

PubMed

Invasion distinguishes malignant from benign primary brain tumors. The molecular mechanisms which permit malignant brain tumor cells to escape from the primary tumor mass and by which they can migrate through normal brain tissue are largely unknown. 13-cis retinoic acid (cRA) can induce morphological, biochemical and functional differentiation characteristics in various malignant tumors. Upon treatment of diffusely invasive hamster glial cells (CxT24neo3) with 30 mu M cRA, we found a significant reduction in cell proliferation in monolayer and spheroid cultures. cRA also inhibits invasion of CxT24neo3 through a reconstituted basement membrane (Matrigel(R)) in a dose dependent manner. Homotypic cell-cell adhesion, on the contrary, is stimulated in the absence of extracellular Ca++ by either treatment or pretreatment of CxT24neo3 with cRA. These phenotypic changes correlate with the induction of the clustering of the neural cell adhesion molecule: N-CAM at sites of cell-cell contact. This phenomenon is observed following immunohistochemical staining for N-CAM of CxT24neo3 cells that were treated with cRA in monolayer cultures. The relationship between reduction of proliferation and invasion in vitro and the increased homotypic cell-cell adhesion with clustering of N-CAM implicates N-CAM as a molecular effector molecule for reduction of malignancy by cRA. PMID:21541625

Boghaert, E; Murali, A; Robertson, D; Jacob, R; Zimmer, S

1996-12-01

282

Using Extensible Heterogeneous Database Transformers  

Microsoft Academic Search

\\u000a Transforming a heterogeneous data model to another heterogeneous data model involves mapping of structural information and\\u000a data layout. For performing the transformation processes this paper presents a flexible and extensible approach for heterogeneous\\u000a database transformation using XML. Basics steps involved are forward transformation and reverse transformation. Between these\\u000a two steps lie two XML documents; one representing the database structure; the

F. Furman Haddix; Kalyan Pydipati

2006-01-01

283

Growth of nitric acid hydrates on thin sulfuric acid films  

NASA Technical Reports Server (NTRS)

Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

1994-01-01

284

Migration by Fourier transform  

Microsoft Academic Search

Wave equation migration is known to be simpler in principle when the horizontal coordinate or coordinates are replaced by their Fourier conjugates. Two practical migration schemes utilizing this concept are developed. One scheme extends the Claerbout finite difference method, greatly reducing dispersion problems usually associated with this method at higher dips and frequencies. The second scheme effects a Fourier transform

R. H. Stolt

1978-01-01

285

BAM Transformations 1. Introduction  

E-print Network

into BAM code, a series of optimizing transforma­ tions is performed. The transformations performed are: (1) synonym optimization, (6) peephole optimization, and (7) determinism optimization. This chapter first definitions are useful: Definition DB: A distant branch is a branch that always transfers control

Bonaventure, Olivier

286

Teaching, Caring, and Transformation  

ERIC Educational Resources Information Center

Educator Bell Hooks acknowledged the fundamental truth that teaching, caring, and transformation are closely linked, that is, that true teaching must be accompanied by a deep level of care in order for learning to take place. No matter how young or old, no matter the subject matter, and no matter where teaching and learning take place--a…

Nieto, Sonia

2012-01-01

287

Transformative Mixed Methods Research  

ERIC Educational Resources Information Center

Paradigms serve as metaphysical frameworks that guide researchers in the identification and clarification of their beliefs with regard to ethics, reality, knowledge, and methodology. The transformative paradigm is explained and illustrated as a framework for researchers who place a priority on social justice and the furtherance of human rights.…

Mertens, Donna M.

2010-01-01

288

Probabilistic predicate transformers  

Microsoft Academic Search

Probabilistic predicates generalize standard predicates over a state space; with probabilistic predicate transformers one thus reasons about imperative programs in terms of probabilistic pre- and postconditions. Probabilistic healthiness conditions generalize the standard ones, characterizing “real” probabilistic programs, and are based on a connection with an underlying relational model for probabilistic execution; in both contexts demonic nondeterminism coexists with probabilistic choice.

Carroll Morgan; Annabelle McIver; Karen Seidel

1996-01-01

289

Fourier Transform I  

NSDL National Science Digital Library

Created by Lang Moore for the Connected Curriculum Project, the purpose of this module is to study the Fourier transform and use it to describe solutions of the heat equation on an infinite rod. This is one of a much larger set of learning modules hosted by Duke University.

Moore, Lang

2010-07-02

290

Optical Haar wavelet transform  

Microsoft Academic Search

An optical Haar mother wavelet is created with a SEMETEX 128 X 128 magneto-optic spatial light modulator. Two techniques for dilating the mother wavelet are explored: (1) aperture stopping and (2) operating the SLM in ternary phase-amplitude mode. Discrete resolution levels of a continuous wavelet transform are obtained by optically correlating a binarized image with multiple dilations of the mother

Thomas J. Burns; Kenneth H. Fielding; Steven K. Rogers; Steven D. Pinski; Dennis W. Ruck

1992-01-01

291

Transforming Education at Einstein  

E-print Network

of Albert Einstein College of Medicine of Yeshiva University #12;2 EinstEin : WintEr/spring 2012 Meet Our trANsfOrMiNg eDuCAtiON At eiNsteiN Education at Albert Einstein College of Medicine is undergoing the magazine for alumni, faculty, students, friends and supporters of Albert einstein College of Medicine

Yates, Andrew

292

Transforming projectile system  

Microsoft Academic Search

The objective of this research was to develop a framework to design a transforming projectile system that has the ability to convert from a simple projectile into a guided projectile that can perform multiple tasks depending on its payload and guiding keyboard. This projectile would be launched from existing standard platforms. Our objective is to determine which design alternative potentially

M. Chafac; K. Howell; C. Williams; J. Sexton

2010-01-01

293

Flexible Power Electronic Transformer  

Microsoft Academic Search

This paper proposes a new modular flexible power electronic transformer (FPET). The proposed FPET is flexible enough to meet future needs of power electronic centralized systems. The main feature of the FPET is the independent operation of modules each of which contains one port. Each port can be considered as input or output, because bidirectional power flow is provided. The

Mehran Sabahi; Ali Yazdanpanah Goharrizi; Seyed Hossein Hosseini; Mohammad Bagher Bana Sharifian; Gevorg B. Gharehpetian

2010-01-01

294

Program refinement by transformation  

Microsoft Academic Search

Program maintenance is simplified when the program to be modified can be viewed as an abstract algorithm to which clearly documented implementation decisions have been applied to produce an efficient realization. The Harvard Program Development System (PDS) [8] is a programming support environment that encourages users to take this view of programs. A user of the PDS creates transformations that

Thomas E. Cheatham Jr.; Glenn H. Holloway; Judy A. Townley

1981-01-01

295

Fourier Transform Mass Spectrometry.  

ERIC Educational Resources Information Center

Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

Gross, Michael L.; Rempel, Don L.

1984-01-01

296

Transforming American Education  

ERIC Educational Resources Information Center

In this article the authors accept as a given the National Education Technology Plan's vision of a transformed education system powered by technology such that learners receive personalized and engaging learning experiences, and where assessment, teaching, infrastructure, and productivity are redefined. The article analyzes this vision of a…

Horn, Michael B.; Mackey, Katherine

2011-01-01

297

Bacterial Transformation Lab  

NSDL National Science Digital Library

The "glowing genes" activity on this engaging website shows students the process of bacterial transformation, a specific type of genetic engineering. This online activity supplements a hands-on lab at the Dolan DNA Learning Center's Harlem DNA Lab, in which plasmids, or tiny loops of DNA that contain genes, are inserted into a harmless strain of E.coli.

Dolan DNA Learning Center * (Dolan DNA Learning Center;)

2010-05-27

298

Transforming Data into Knowledge  

ERIC Educational Resources Information Center

School systems can be data rich and information poor if they do not understand and manage their data effectively. The task for school leaders is to put existing data into a format that lends itself to answering questions and improving outcomes for the students. Common barriers to transforming data into knowledge in education settings often include…

Mills, Lane

2006-01-01

299

9 (extension) " (Z transform)"  

E-print Network

10 9 (extension) (CtFT) " (Z transform)" (discrete-time aperiodic signal) (Dt n r r [ ]x n " (ROC: region of convergence)" ROC ( )X z [ ]x n #12;10-3 { }Re z { }Im z 1 X z a u n z az - - =- = = = (10.8) ( )1 0 n n az - = ROC ( )X z 1 1az- 0 1 1 n

Kovintavewat, Piya

300

Transformations: Translation (NLVM)  

NSDL National Science Digital Library

This Java applet enables learners to explore the translation transformation (sliding) both informally and within a coordinate system. Students select and compose shapes and manipulate the ends of a translation vector to see the effect on a translated image. Links to instructions, activities and teacher/parent information are included.

2011-01-01

301

Transformer insulation life assessment  

Microsoft Academic Search

This paper presents novel techniques for life assessment of the insulation of the generator stepup units in power plants. Load and ambient temperatures are two important factors that influence the life of insulation in transformers. Hourly load and ambient temperatures obtained through condition monitoring are used to assess the operating profile of the equipment. Modeling techniques for estimating load factors

Kshira T. Muthanna; Abhinanda Sarkar; Kaushik Das; Kurt Waldner

2006-01-01

302

Transforming Nursery Education.  

ERIC Educational Resources Information Center

Reviews "Transforming Nursery Education" by Peter Moss and Helen Penn. Maintains that the book clarifies issues and options in child care policy in Great Britain, is highly applicable to the situation in Canada, articulates the importance of values as central to developing early childhood policy and programs, highlights the importance of learning…

Friendly, Martha

1998-01-01

303

Strongly Acidic Auxin Indole-3-Methanesulfonic Acid  

PubMed Central

A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

1985-01-01

304

Rainbow Fourier Transform  

NASA Technical Reports Server (NTRS)

We present a novel technique for remote sensing of cloud droplet size distributions. Polarized reflectances in the scattering angle range between 135deg and 165deg exhibit a sharply defined rainbow structure, the shape of which is determined mostly by single scattering properties of cloud particles, and therefore, can be modeled using the Mie theory. Fitting the observed rainbow with such a model (computed for a parameterized family of particle size distributions) has been used for cloud droplet size retrievals. We discovered that the relationship between the rainbow structures and the corresponding particle size distributions is deeper than it had been commonly understood. In fact, the Mie theory-derived polarized reflectance as a function of reduced scattering angle (in the rainbow angular range) and the (monodisperse) particle radius appears to be a proxy to a kernel of an integral transform (similar to the sine Fourier transform on the positive semi-axis). This approach, called the rainbow Fourier transform (RFT), allows us to accurately retrieve the shape of the droplet size distribution by the application of the corresponding inverse transform to the observed polarized rainbow. While the basis functions of the proxy-transform are not exactly orthogonal in the finite angular range, this procedure needs to be complemented by a simple regression technique, which removes the retrieval artifacts. This non-parametric approach does not require any a priori knowledge of the droplet size distribution functional shape and is computationally fast (no look-up tables, no fitting, computations are the same as for the forward modeling).

Alexandrov, Mikhail D.; Cairns, Brian; Mishchenko, Michael I.

2012-01-01

305

Acid rain  

Microsoft Academic Search

Acid precipitation is a global problem. The effects were first seen in Europe; it affects the Great Lakes and the Midwest because higher-than-normal levels of acidity in rain are found in these areas. Several bays of the Great Lakes are now known to receive substantial runoff from freshwater streams that have been made acidic by acid rains. These areas may

1979-01-01

306

Transformation of unsymmetrical dimethylhydrazine in soils  

NASA Astrophysics Data System (ADS)

The transformation of unsymmetrical dimethylhydrazine (UDMH, a propellant component) applied at a rate of 240 g/kg to different soils was studied. The kinetic regularities of a decrease in the UDMH concentration and the accumulation of its transformation products leached out from dry and wet soils were investigated 3, 10, 30, and 90 days after its application. As the UDMH enters the soil, it vaporizes, and the elevated moisture of the soils promotes an increase in the pollutant's concentration at the initial moment; then, the concentration differences become leveled to the end of observation. It was also shown that the higher the organic matter content in the soil, the higher the UDMH concentration. However, at the end of the observations, on the 90th day, the total UDMH concentration did not exceed 0.5% of its initial content. In order to explain the UDMH behavior in the soils, one should take into account the existence of different forms of this substance and the changes in their ratios with time. The main portion of UDMH retained by the soil in the free form is transformed during the first few days. The products of the UDMH transformation, such as 1-methyl-1,2,4-triazole, formic acid dimethylhydrazide, dimethylguanidine, and dimethylamine are formed in considerable amounts, and their concentrations should be controlled in places of UDMH spills on soils.

Rodin, I. A.; Smirnov, R. S.; Smolenkov, A. D.; Krechetov, P. P.; Shpigun, O. A.

2012-04-01

307

Canonical Transformations in Quantum Mechanics  

E-print Network

Three elementary canonical transformations are shown both to have quantum implementations as finite transformations and to generate, classically and infinitesimally, the full canonical algebra. A general canonical transformation can, in principle, be realized quantum mechanically as a product of these transformations. It is found that the intertwining of two super-Hamiltonians is equivalent to there being a canonical transformation between them. A consequence is that the procedure for solving a differential equation can be viewed as a sequence of elementary canonical transformations trivializing the super-Hamiltonian associated to the equation. It is proposed that the quantum integrability of a system is equivalent to the existence of such a sequence.

Arlen Anderson

1992-05-22

308

Polystyrene sulphonic acid resins with enhanced acid strength via macromolecular self-assembly within confined nanospace  

NASA Astrophysics Data System (ADS)

Tightening environmental legislation is driving the chemical industries to develop efficient solid acid catalysts to replace conventional mineral acids. Polystyrene sulphonic acid resins, as some of the most important solid acid catalysts, have been widely studied. However, the influence of the morphology on their acid strength—closely related to the catalytic activity—has seldom been reported. Herein, we demonstrate that the acid strength of polystyrene sulphonic acid resins can be adjusted through their reversible morphology transformation from aggregated to swelling state, mainly driven by the formation and breakage of hydrogen bond interactions among adjacent sulphonic acid groups within the confined nanospace of hollow silica nanospheres. The hybrid solid acid catalyst demonstrates high activity and selectivity in a series of important acid-catalysed reactions. This may offer an efficient strategy to fabricate hybrid solid acid catalysts for green chemical processes.

Zhang, Xiaomin; Zhao, Yaopeng; Xu, Shutao; Yang, Yan; Liu, Jia; Wei, Yingxu; Yang, Qihua

2014-01-01

309

Quantum Canonical Transformations and Integrability: Beyond Unitary Transformations  

E-print Network

Quantum canonical transformations are defined in analogy to classical canonical transformations as changes of the phase space variables which preserve the Dirac bracket structure. In themselves, they are neither unitary nor non-unitary. A definition of quantum integrability in terms of canonical transformations is proposed which includes systems which have fewer commuting integrals of motion than degrees of freedom. The important role of non-unitary transformations in integrability is discussed.

Arlen Anderson

1993-02-15

310

Liquid Metal Transformers  

E-print Network

The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series of complex transformation behaviors such as self-assembling of a sheet of liquid metal film into a single sphere, quick mergences of separate metal droplets, controlled self-rotation and planar locomotion of liquid metal objects can be realized. Meanwhile, it was also found that two accompanying water vortexes were induced and reliably swirled near the rotating liquid metal sphere. Further, effects of the shape, size, voltage, orientation and geometries of the electrodes to control the liquid metal transformers were clar...

Sheng, Lei; Liu, Jing

2014-01-01

311

Genetic transformation in bacteria  

Microsoft Academic Search

Certain species of bacteria can become competent to take up high molecular weight DNA from the surrounding medium. DNA homologous\\u000a to resident chromosomal DNA is transported, processed and recombined with the resident DNA. There are some variations in steps\\u000a leading to transformation between Gram-positive bacteria likebiplococcus pneumoniae and Gram-negative bacteria represented byHaemophilus influenzae but the integration is by single-strand displacement

N. K. Notani; V. P. Joshi; R. P. Kanade

1984-01-01

312

Laminated piezoelectric transformer  

NASA Technical Reports Server (NTRS)

A laminated piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. The input portions are polarized to deform in a longitudinal plane and are bonded to an output portion. The deformation of the input portions is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

Vazquez Carazo, Alfredo (Inventor)

2006-01-01

313

Transformer Impedance Reflection Demonstration  

NASA Astrophysics Data System (ADS)

Questions often arise as to how a device attached to a transformer can draw power from the electrical power grid since it seems that the primary and secondary are not connected to one another. However, a closer look at how the primary and secondary are linked together magnetically and a consideration of the role of Lenz's law in this linkage may help to clear up this confusion.

Layton, William

2014-10-01

314

Multipath Transformational Development of User Interfaces with Graph Transformations  

NASA Astrophysics Data System (ADS)

In software engineering, transformational development is aimed at developing computer systems by transforming a coarse-grained specification of a system to its final code through a series of transformation steps. Transformational development is known to bring benefits such as: correctness by construction, explicit mappings between development steps, and reversibility of transformations. No comparable piece exists in the literature that provides a formal system applying transformational development in the area of user interface engineering. This chapter defines such a system. For this purpose, a mathematical system for expressing specifications and transformation rules is introduced. This system is based on graph transformations. The problem of managing the transformation rules is detailed, e.g., how to enable a developer to access, define, extend, restrict or relax, test, verify, and apply appropriate transformations. A tool supporting this development paradigm is also described and exemplified. Transformational development, applied to the development of user interfaces of interactive systems, allows reusability of design knowledge used to develop user interfaces and fosters incremental development of user interfaces by applying alternative transformations.

Limbourg, Quentin; Vanderdonckt, Jean

315

Acid deposition. Environmental, economic, and policy issues  

Microsoft Academic Search

This book presents information on the following topics: Atmospheric acidification chemistry; SOâ oxidation in summertime cloud water at Whiteface Moutain; methods for diagnosing the sources of acid deposition; the use of long range transport models in determining emission control strategies for acid deposition; the sedimentary record of atmospheric pollution in Jerseyfield Lake, Adirondack Mountains, New York; transformation of nitric, sulfuric

D. P. Adams; W. P. Page

1985-01-01

316

Microbial transformation of styrene by anaerobic consortia.  

PubMed

Methanogenic microbial consortia, originally enriched from anaerobic sewage sludge with ferulic acid or styrene (vinylbenzene) as sole organic carbon and energy sources, were used to study transformation of styrene under strictly anaerobic conditions. Styrene, which was added as the substrate in a range of concentrations from 0.1 to 10 mmol/l, was extensively degraded but no methane production was observed during incubation for eight months. The addition of yeast extract during the enrichment stage completely inhibited degradation of styrene. Gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) analyses of the culture fluid, and GC analyses of the anaerobic headspace, indicated that the transformation of this arylalkene was initiated through an oxidation-reduction reaction and that the favoured mechanism was most likely the addition of water across the double bond in the alkenyl side-chain. The degradation proceeded through to carbon dioxide, the final product. Benzoic acid and phenol were transient compounds found in highest concentrations in the spent culture fluid and are suggested as the key intermediates of the transformation process. The tentative routes of anaerobic transformation partially overlap with those previously proposed for aromatic hydrocarbons such as toluene. Several pure cultures, which were tentatively identified as Clostridium spp. and Enterobacter spp., were isolated from the styrene-degrading consortia. Two of these cultures were demonstrated to grow on styrene as sole carbon and energy source. Additionally, a pure culture of Enterobacter cloacae DG-6 (ATCC 35929) which had been isolated previously from the ferulate-degrading consortium, was shown to degrade styrene through to carbon dioxide. PMID:2272946

Grbi?-Gali?, D; Churchman-Eisel, N; Mrakovi?, I

1990-08-01

317

Transformational Leadership, Integrity, and Power  

ERIC Educational Resources Information Center

Transformational leadership enjoys widespread appeal among student affairs professionals. National Association of Student Personnel Administrators (NASPA) and American College Personnel Association (ACPA) conferences frequently feature speakers who promote transformational leadership's two primary tenets: (1) change is the central purpose of…

Harrison, Laura M.

2011-01-01

318

Transformer Abdullah Al-Otaibi  

E-print Network

induces a changing voltage in the secondary. II. HISTORY Michael Faraday demonstrated the principle of the transformer in 1831. The transformer is used by Faraday only to demonstrate the principle of electromagnetic

Masoudi, Husain M.

319

Transformation method and wave control  

NASA Astrophysics Data System (ADS)

Transformation method provides an efficient way to control wave propagation by materials. The transformed relations for field and material during a transformation are essential to fulfill this method. We propose a systematic method to derive the transformed relations for a general physic process, the constraint conditions are obtained by considering geometrical and physical constraint during a mapping. The proposed method is applied to Navier's equation for elastodynamics, Helmholtz's equation for acoustic wave and Maxwell's equation for electromagnetic wave, the corresponding transformed relations are derived, which can be used in the framework of transformation method for wave control. We show that contrary to electromagnetic wave, the transformed relations are not uniquely determined for elastic wave and acoustic wave, so we have a freedom to choose them differently. Using the obtained transformed relations, we also provide some examples for device design, a concentrator for elastic wave, devices for illusion acoustic and illusion optics are conceived and validated by numerical simulations.

Chang, Zheng; Hu, Jin; Hu, Geng-Kai

2010-12-01

320

Transforming Content into Effective Composition.  

ERIC Educational Resources Information Center

Demonstrates key concepts of transformational generative grammar that can be applied to a discussion of the composing process. Discusses relevant linguistic concepts and selected transformational processes to illustrate how writers achieve certain effects. (RL)

Esau, Helmut

1980-01-01

321

Distinctive transforming genes in x-ray-transformed mammalian cells.  

PubMed Central

DNAs from hamster embryo cells and mouse C3H/10T1/2 cells transformed in vitro by x-irradiation into malignant cells transmit the radiation transformation phenotype by producing transformed colonies (transfectants) in two mouse recipient lines, the NIH 3T3 and C3H/101/2 cells, and in a rat cell line, the Rat-2 cells. DNAs from unirradiated cells or irradiated and visibly untransformed cells do not produce transformed colonies. The transfectants grow in agar and form tumors in nude mice. Treatment of the DNAs with restriction endonucleases prior to transfection indicates that the same transforming gene (oncogene) is present in each of the transformed mouse cells and is the same in each of the transformed hamster cells. Southern blot analysis of 3T3 or Rat-2 transfectants carrying oncogenes from radiation-transformed C3H/10T1/2 or hamster cells indicates that the oncogenes responsible for the transformation of 3T3 cells are not the Ki-ras, Ha-ras, or N-ras genes, nor are they neu, trk, raf, abl, or fms, although quick blot analysis using 11 oncogene probes detected increased transcripts of c-abl and c-fms in the 3T3 transformants containing oncogenic sequences from the x-ray-transformed C3H/10T1/2 cells. The work demonstrates that DNAs from mammalian cells transformed into malignancy by direct exposure in vitro to radiation contain genetic sequences with detectable transforming activity in three recipient cell lines. The results provide evidence that DNA is the target of radiation carcinogenesis induced at a cellular level in vitro. The experiments indicate that malignant radiogenic transformation in vitro of hamster embryo and mouse C3H/10T1/2 cells involves the activation of unique non-ras transforming genes, which heretofore have not been described. Images PMID:3027705

Borek, C; Ong, A; Mason, H

1987-01-01

322

Transformation of Catalpa ovata by Agrobacterium rhizogenes and phenylethanoid glycosides production in transformed root cultures.  

PubMed

Transformed root cultures of Catalpa ovata were established following shoots infection with four agropine strains of Agrobacterium rhizogenes. Frequency of root formation was dependent on the bacterial strain and the presence of acetosyringone in the incubation medium. It is the first report concerning the possibility of transforming Catalpa ovata by A. rhizogenes. Both transformed and untransformed root cultures of C. ovata were studied for their growth and phenylethanoid glycoside production. As with the roots of intact plants, cis- and trans-verbascoside as well as martynoside were produced in transformed and untransformed root cultures of C. ovata. In hairy roots, total (cis + trans) verbascoside production could be stimulated up to three-fold of that of roots of 6-month-old plants grown in a greenhouse, by using an appropriate root line cultured in liquid 1/2 B5 Gamborg medium containing indole-3-butyric acid (0.1 mg/l) in the dark but not light conditions. Transformed and untransformed root cultures of C. ovata were also found to have 10 times higher martynoside production than roots of intact plants. PMID:11421453

Wysoki?ska, H; Lisowska, K; Floryanowicz-Czekalska, K

2001-01-01

323

Thin-Film Power Transformers  

NASA Technical Reports Server (NTRS)

Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

Katti, Romney R.

1995-01-01

324

Reducing losses in distribution transformers  

Microsoft Academic Search

This paper examines three methods of reducing distribution transformer losses. The first method analyzes the effects of using aluminum electromagnetic shields in a distribution transformer. The goal of placing electromagnetic shields in the distribution-transformer tank walls is to reduce the stray losses. A 500 kVA shell-type transformer was used in the experiments. The overall results presented indicate that stray losses

Juan Carlos Olivares; Yilu Liu; Jose M. Cañedo; Rafael Escarela-Pérez; Johan Driesen; Pablo Moreno

2003-01-01

325

Adaptive wavelet transforms via lifting  

Microsoft Academic Search

This paper develops two new adaptive wavelet transforms based on the lifting scheme. The lifting construction exploits a spatial-domain, prediction-error interpretation of the wavelet transform and provides a powerful framework for designing customized transforms. We use the lifting construction to adaptively tune a wavelet transform to a desired signal by optimizing data-based prediction error criteria. The performances of the new

Roger L. Claypoole; Richard G. Baraniuk; Robert D. Nowak

1998-01-01

326

Nonlocal conservation laws and related Bäcklund transformations via reciprocal transformations  

E-print Network

A set of infinitely many nonlocal conservation laws are revealed for (1+1)-dimensional evolution equations. For some special known integrable systems, say, the KdV and Dym equations, it is found that different nonlocal conservation laws can lead to same new integrable systems via reciprocal transformation. On the other hand, it can be considered as one solution of the new model obtained via reciprocal transformation(s) can be changed to different solutions of the original model. The fact indicates also that two or more different (local and nonlocal) conservation laws can be used to find implicit auto-B\\"acklund transformations via reciprocal transformation to other systems.

Sen-Yue Lou

2014-02-28

327

TRANSFORMATION REACTIONS BETWEEN PNEUMOCOCCUS AND THREE STRAINS OF STREPTOCOCCI  

PubMed Central

Reciprocal transformation reactions to streptomycin resistance have been demonstrated between pneumococcus and 2 strains of viridans streptococci, which by the usual bacteriological criteria are distantly related to pneumococcus. Desoxyribonucleic acid (DNA) extracts of a strain of streptomycin-resistant Streptococcus salivarius have been found capable of transforming pneumococcus and two strains of viridans streptococci but the strain itself was not transformed by autologous or heterologous DNA extracts. The two strains of viridans streptococci were more efficient than pneumococcus as receptors of both autologous and heterologous transforming principles. It is inferred, therefore, that efficiency of transformation does not necessarily indicate closeness of relationship among bacteria. The efficiency of transforming principles (TP's) from three streptococcal strains to induce streptomycin resistance in pneumococcus increased following their reduplication in pneumococcus. At the same time the efficiency of two of these TP's to transform streptococcus was reduced. Resistance to optochin (ethylhydrocupreine), a characteristic of most streptococci, can be transferred to pneumococcus, a naturally susceptible species, by transformation reactions. PMID:13449235

Bracco, Richard M.; Krauss, Marjorie R.; Roe, Amy S.; MacLeod, Colin M.

1957-01-01

328

Enhancing Understanding of Transformation Matrices  

ERIC Educational Resources Information Center

With the Common Core State Standards' emphasis on transformations, teachers need a variety of approaches to increase student understanding. Teaching matrix transformations by focusing on row vectors gives students tools to create matrices to perform transformations. This empowerment opens many doors: Students are able to create the matrices for…

Dick, Jonathan; Childrey, Maria

2012-01-01

329

Lightning Protection for Distribution Transformers  

Microsoft Academic Search

Usual methods of connecting arresters for the protection of distribution transformers are often inadequate. In service some transformers still flash over although the arrester, in itself, is capable of protecting the transformer with a large margin of safety. Surge current flowing to ground through the ground lead of the arrester gives rise to inductive drop and resistance drop voltages. These

A. M. Opsahl; A. S. Brookes; R. N. Southgate

1932-01-01

330

Some Special Fourier Transform Pairs  

E-print Network

Some Special Fourier Transform Pairs 24.3 Introduction ' & $ % Prerequisites Before starting period. For a non-periodic real signal f(t) with Fourier Transform F() the corresponding result is - f2): Workbook Level 2 24.3: Some Special Fourier Transform Pairs 2 #12;Wehave F()=F{e-t u(t)}= 1 1+i , so |F()|2

Vickers, James

331

Mineral insulating oil in transformers  

Microsoft Academic Search

Nearly all load bearing transformers in electric power delivery systems around the world are filled with liquid. The liquid functions both as an electrical insulation and as a heat transfer fluid. The liquid in almost all of these units is transformer oil, petroleum-based insulating oil refined specifically to meet the requirements of this application. Transformers in electric power distribution and

T. O. Rouse

1998-01-01

332

Transformational leadership and team performance  

Microsoft Academic Search

Despite transformational leadership enjoying success and attention as an exceptional leadership theory, few scholars have investigated a specific link between transformational leadership theory and team performance. As such, we discuss how transformational leadership theory can provide a framework in which to investigate a leader's impact on team performance. We posit that idealized influence\\/inspirational motivation, intellectual stimulation and individualized consideration could

Shelley D. Dionne; Francis J. Yammarino; Leanne E. Atwater; William D. Spangler

2004-01-01

333

Rosmarinic acid  

Microsoft Academic Search

Rosmarinic acid is an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. It is commonly found in species of the Boraginaceae and the subfamily Nepetoideae of the Lamiaceae. However, it is also found in species of other higher plant families and in some fern and hornwort species. Rosmarinic acid has a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and

Maike Petersen; Monique S. J Simmonds

2003-01-01

334

Chemical Transformations of Nanosilver in Biological Environments  

PubMed Central

The widespread use of silver nanoparticles (Ag-NPs) in consumer and medical products provides strong motivation for a careful assessment of their environmental and human health risks. Recent studies have shown that Ag-NPs released to the natural environment undergo profound chemical transformations that can affect silver bioavailability, toxicity, and risk. Less is known about Ag-NP chemical transformations in biological systems, though the medical literature clearly reports that chronic silver ingestion produces argyrial deposits consisting of silver-, sulfur-, and selenium-containing particulate phases. Here we show that Ag-NPs undergo a rich set of biochemical transformations, including accelerated oxidative dissolution in gastric acid, thiol binding and exchange, photoreduction of thiol- or protein-bound silver to secondary zero-valent Ag-NPs, and rapid reactions between silver surfaces and reduced selenium species. Selenide is also observed to rapidly exchange with sulfide in preformed Ag2S solid phases. The combined results allow us to propose a conceptual model for Ag-NP transformation pathways in the human body. In this model, argyrial silver deposits are not translocated engineered Ag-NPs, but rather secondary particles formed by partial dissolution in the GI tract followed by ion uptake, systemic circulation as organo-Ag complexes and immobilization as zero-valent Ag-NPs by photoreduction in light affected skin regions. The secondary Ag-NPs then undergo detoxifying transformations into sulfides, and further into selenides or Se/S mixed phases through exchange reactions. The formation of secondary particles in biological environments implies that Ag-NPs are not only a product of industrial nanotechnology, but have long been present in the human body following exposure to more traditional chemical forms of silver. PMID:23046098

Liu, Jingyu; Wang, Zhongying; Liu, Frances D.; Kane, Agnes B.; Hurt, Robert H.

2012-01-01

335

Acid deposition. Environmental, economic, and policy issues  

SciTech Connect

This book presents information on the following topics: Atmospheric acidification chemistry; SO/sub 2/ oxidation in summertime cloud water at Whiteface Moutain; methods for diagnosing the sources of acid deposition; the use of long range transport models in determining emission control strategies for acid deposition; the sedimentary record of atmospheric pollution in Jerseyfield Lake, Adirondack Mountains, New York; transformation of nitric, sulfuric and organic acids on the Bickford Reservoir watershed; and acidification impacts on fish populations, forest soils and leaf surfaces. The effect of acidity and metal ions on water movement through red spruce is discussed as well as the economic impacts and policy issues associated with acid rain in different countries.

Adams, D.P.; Page, W.P.

1985-01-01

336

Shikimic Acid  

NSDL National Science Digital Library

The molecule for this month comes from the article Isolation of Shikimic Acid from Star Aniseed by Richard Payne and Michael Edmonds. Shikimic acid plays a key role in the biosynthesis of many important natural products including aromatic amino acids, alkaloids, phenolics, and phenylpropanoids. It plays such an important role that one of the key biosynthetic pathways is referred to as the shikimate pathway.

337

Acid rain  

Microsoft Academic Search

For the past five years, scientists at the Univ. of Colorado have been measuring acid precipitation in a subalpine watershed of the Colorado Rockies. Their measurements of snow and rain and creek water show a strong trend of increasing acidity that is traceable to the chemical reactions of burning fossil fuels. Possible effects of acid precipitation on the watershed's aquatic

Caile

2009-01-01

338

Secoiridoids and antifungal aromatic acids from Gentiana algida  

Microsoft Academic Search

Fractionation of an aqueous acetone extract of the whole herb of Gentiana algida gave one new [2?-(o,m-dihydroxybenzyl)sweroside] and five known secoiridoids, together with anofinic acid, fomannoxin acid, sitosterol, daucosterol, stigmasterol, oleanolic acid, orientin and gentianose. The structures were determined by spectral methods and a few chemical transformations. Anofinic acid and fomannoxin acid were found to be active against Cladosporium cucumerinum,

R. X. Tan; J.-L. Wolfender; W. G. Ma; L. X. Zhang; K. Hostettmann

1996-01-01

339

Anthranilic acid derivatives and other components from Ononis pusilla.  

PubMed

Three new anthranilic acid derivatives: N-(R)-3'-hydroxydocosanoylanthranilic acid (1), N-(R)-3'-hydroxytricosanoylanthranilic acid (2) and N-(R)-3'-hydroxytetracosanoylanthranilic acid (3), in addition to one knownanthranilic acid and six known flavonoids, were isolated from the ethyl acetate extract of Ononis pusilla L. The structures of the isolated compounds were assigned by spectroscopic methods, including 1D and 2D homo and heteronuclear NMR experiments, ESI-MS, chemical transformation and comparison with literature data. PMID:25233597

Khouni, Lyes; Long, Christophe; Haba, Hamada; Molinier, Nicolas; Benkhaled, Mohammed

2014-08-01

340

Microbial transformation of cycloastragenol.  

PubMed

The microbial transformation of cycloastragenol by the fungi Cunninghamella blakesleeana NRRL 1369 and Glomerella fusarioides ATCC 9552, and the bacterium Mycobacterium sp. NRRL 3805 were investigated. Both fungi mainly provided hydroxylated metabolites together with products formed by cyclization, dehydrogenation and Baeyer-Villiger oxidation resulting in a ring cleavage. The bacteria yielded only a single oxidation product, namely, 3-oxo-cycloastragenol. Structures of the metabolites were elucidated by 1-D ((1)H,(13)C), 2-D NMR (COSY, HMBC, HMQC) and HRMS analyses. PMID:23357596

Kuban, Melis; Öngen, Gaye; Khan, Ikhlas A; Bedir, Erdal

2013-04-01

341

Thermal energy transformer  

NASA Technical Reports Server (NTRS)

For use in combination with a heat engine, a thermal energy transformer is presented. It is comprised of a flux receiver having a first wall defining therein a radiation absorption cavity for converting solar flux to thermal energy, and a second wall defining an energy transfer wall for the heat engine. There is a heat pipe chamber interposed between the first and second walls having a working fluid disposed within the chamber and a wick lining the chamber for conducting the working fluid from the second wall to the first wall. Thermal energy is transferred from the radiation absorption cavity to the heat engine.

Berdahl, C. M.; Thiele, C. L. (inventors)

1979-01-01

342

A Fast Hermite Transform?  

PubMed Central

We present algorithms for fast and stable approximation of the Hermite transform of a compactly supported function on the real line, attainable via an application of a fast algebraic algorithm for computing sums associated with a three-term relation. Trade-offs between approximation in bandlimit (in the Hermite sense) and size of the support region are addressed. Numerical experiments are presented that show the feasibility and utility of our approach. Generalizations to any family of orthogonal polynomials are outlined. Applications to various problems in tomographic reconstruction, including the determination of protein structure, are discussed. PMID:20027202

Leibon, Gregory; Rockmore, Daniel N.; Park, Wooram; Taintor, Robert; Chirikjian, Gregory S.

2008-01-01

343

Bacterial Transformation Lab  

NSDL National Science Digital Library

This PDF, part of the classroom activities site by Biotechnology Education and Training Sequence Investment (BETSI), introduces the concept of recombinant DNA and a process called transformation. Here, instructors will find detailed lab instructions/diagrams that trace out the introduction of a recombinant plasmid into a foreign bacteria resulting in the "change of the bacteria's genetic make-up and traits." With the end result of the lab being a product that "glow[s] bright green," this will be a fun lab for any chemistry or biochemistry classroom. The site even playfully boasts, "[that] you will all be genetics engineers" by the end of this experiment!

2008-12-10

344

DE MAGNO MAGNETE TELLURE O VELIK EM MAGNETU ZEMSK EM  

E-print Network

´ansk´ym plavb´am Od staroveku k zaoce´ansk´ym plavb´am 12. stol. kompas pronikl do Evropy (zminuj´i napr´ansk´ym plavb´am od 13. stol. vyuzit´i v n´amorn´i navigaci (V. da Gama, K. Kolumbus, F. Magellan) J. Vel

Cerveny, Vlastislav

345

LETTRES A LA RDACTION REDRESSEMENT PAR CONTACT SUR LE TELLURE  

E-print Network

'extraction et revêtus d'une couche d'oxyde : Mg, Ca, Ba, Sr, Li, Na, K; les métaux Zn, Be, Al sont dans un cas, débitanti mA redressé sous I V maximum; on favorise le redressement par Zif en l'oxydant en surface par NO3H couche d'oxyde recouvrant le métal; ces oxydes, comme BaO, MgO, ZnO, peuvent devenir de type n par excès

Boyer, Edmond

346

MICROBIAL TRANSFORMATION KINETICS OF XENOBIOTICS IN AQUATIC ENVIRONMENT  

EPA Science Inventory

The microbiological transformation rates of four organic compounds, the butoxy-ethylester of 2,4-dichlorophenoxyacetic acid (2,4-DBE), p-cresol, alpha-naphthol and quinoline, added to natural water samplers were examined in laboratory experiments. Graphical analysis of the data w...

347

Transformation of the Plant Growth Regulator Daminozide (Alar) and  

E-print Network

Transformation of the Plant Growth Regulator Daminozide (Alar) and Structurally Related Compounds,N- Dimethylsuccinamic acid (SA), in contrast, breaks down via a hydrolytic mechanism. Introduction The plant growth heavily used plant growth regulators in the U.S. (5). In addition to daminozide, the hydrazide moiety

Huang, Ching-Hua

348

Recent advances in plant transformation.  

PubMed

Plant genetic engineering has become one of the most important molecular tools in the modern molecular breeding of crops. Over the last decade, significant progress has been made in the development of new and efficient transformation methods in plants. Despite a variety of available DNA delivery methods, Agrobacterium- and biolistic-mediated transformation remain the two predominantly employed approaches. In particular, progress in Agrobacterium-mediated transformation of cereals and other recalcitrant dicot species has been quite remarkable. In the meantime, other transgenic-enabling technologies have emerged, including generation of marker-free transgenics, gene targeting, and chromosomal engineering. Although transformation of some plant species or elite germplasm remains a challenge, further advancement in transformation technology is expected because the mechanisms of governing the regeneration and transformation processes are now better understood and are being creatively applied to designing improved transformation methods or to developing new enabling technologies. PMID:21181522

Barampuram, Shyamkumar; Zhang, Zhanyuan J

2011-01-01

349

Image Transformations-Montserrat  

NASA Technical Reports Server (NTRS)

A slightly oblique digital photograph of Montserrat taken from the International Space Station was posted to Earth Observatory in December 2001. An Earth Observatory reader used widely available software to correct the oblique perspective and adjust the color. The story of how he modified the image includes step-by-step instructions that can be applied to other photographs. Photographs of Earth taken by astronauts have shaped our view of the Earth and are part of our popular culture because NASA makes them easily accessible to the public. Read the Transformations Story for more information. The original image was digital photograph number ISS002-E-9309, taken on July 9, 2001, from the International Space Station and was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth. Bill Innanen provided the transformed image and the story of how he did it.

2002-01-01

350

Energy: Energy Transformations  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Energy SciPack. It provides a conceptual and real-world understanding of how energy is transferred, from object to object and from one form of energy to another. Although the various forms of energy appear different, each can be measured in a closed system. This makes it possible to keep track of how much of one form of energy is converted into another form. Most of what goes on in the universe--from exploding stars and biological growth to the operation of machines and the motion of people--involves some form of energy being transformed into another form. The law of conservation of energy states that whenever the amount of energy in one place (or form) decreases, the amount of energy in other places (or forms) increases by the same amount. Learning Outcomes:� Recognize that there are ways to measure the amount of different kinds of energy that allow us to track how much of one form is changed into another.� Recognize that energy is conserved, meaning it is not "used up" and does not appear out of nowhere.� Give examples of transformation of energy, including recognizing the forms of energy involved.� Construct an argument against an example that claims to be a perpetual motion machine.

National Science Teachers Association (NSTA)

2006-11-01

351

Liquid Metal Transformers  

E-print Network

The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series of complex transformation behaviors such as self-assembling of a sheet of liquid metal film into a single sphere, quick mergences of separate metal droplets, controlled self-rotation and planar locomotion of liquid metal objects can be realized. Meanwhile, it was also found that two accompanying water vortexes were induced and reliably swirled near the rotating liquid metal sphere. Further, effects of the shape, size, voltage, orientation and geometries of the electrodes to control the liquid metal transformers were clarified. Such events are hard to achieve otherwise on rigid metal or conventional liquid spheres. This finding has both fundamental and practical significances which suggest a generalized way of making smart soft machine, collecting discrete metal fluids, as well as flexibly manipulating liquid metal objects including accompanying devices.

Lei Sheng; Jie Zhang; Jing Liu

2014-01-30

352

Transformational silicon electronics.  

PubMed

In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 ?m), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry's most advanced high-?/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. PMID:24476361

Rojas, Jhonathan Prieto; Torres Sevilla, Galo Andres; Ghoneim, Mohamed Tarek; Inayat, Salman Bin; Ahmed, Sally M; Hussain, Aftab Mustansir; Hussain, Muhammad Mustafa

2014-02-25

353

EFFECTS OF MICROBIAL COMMUNITY INTERACTIONS ON TRANSFORMATION RATES OF XENOBIOTIC CHEMICALS  

EPA Science Inventory

The effects of culture filtrates, mixed populations, and common microbial exudates on bacterial transformations of three agricultural and industrial chemicals were investigated. Test chemicals included methyl parathion, diethyl phthalate, and 2,4-dichlorophenoxyacetic acid butoxy...

354

Advanced concepts for transformers pressboard dielectric constant and mechanical strength  

NASA Astrophysics Data System (ADS)

Of the numerous electrical considerations in a material, the value of the dielectric constant serves as an important criterion in designing proper insulation systems. Ways to reduce the dielectric constant of solid (fibrous) insulating materials were investigated. A literature search was made on cellulosic and synthetic fibers and also additives which offered the potential for dielectric constant reduction of the solid insulation. Sample board structures were produced in the laboratory and tested for electrical, mechanical and chemical characteristics. Electrical tests determined the suitability of the material at transformer test and operating conditions. The mechanical tests established the physical characteristics of the modified board structures. Chemical tests checked the conductivity of the aqueous extract, acidity, and ash content. Further, compatibility with transformer oil and some aging tests were performed. An actual computer transformer design was made based on one of the modified board structures and the reduction in core steel and transformer losses were shown.

1982-03-01

355

Lorentz-transformation and Galileo-transformation windows  

NASA Astrophysics Data System (ADS)

We define Lorentz-transformation windows as windows that change the direction of transmitted light rays like a Lorentz transformation. Similarly, Galileo-transformation windows change the direction of transmitted light rays like a Galileo transformation. This light-ray-direction change distorts the scene seen through such a window in the same way in which the scene would be distorted in a photo taken with a camera moving through the scene. Lorentz-transformation windows can also undo the distortion of the scene when moving at relativistic velocity relative to it. For small angles between the direction of the light rays and the direction of the velocity, Galileo-transformation windows can be realised with relatively simple telescope windows, which consist of arrays of identical micro-telescopes.

Oxburgh, Stephen; Gray, Norman; Hendry, Martin; Courtial, Johannes

2014-09-01

356

Identification of Lactic Acid Bacteria in Michigan Cherry Wines  

Microsoft Academic Search

Many factors contribute to the final flavor of wine. One factor is malolactic fermentation, during which lactic acid bacteria (LAB) transform the harsh tasting malic acid into a more drinkable lactic acid in grape wine. The role of LAB in the production of cherry wine is completely unknown. The goal of this study is to identify the species of LAB

Emily Henk; Margaret Dietrich; Terri Weese

2008-01-01

357

Clifford Algebra and Space-Time Transformations: Lorentz Transformation and Inertial Transformation  

E-print Network

We review the Inertial transformation and Lorentz transformation under a new context, by using Clifford Algebra or Geometric Algebra. The apparent contradiction between theses two approach is simply stems from different procedures for clock synchronization associated with different choices of the coordinates used to describe the physical world. We find the physical and coordinates components of both transformations. A important result is that in the case of Inertial transformation the physical components are exactly the Galilean transformations, but the speed of light is not c. Another interesting result is due to the fact the Lorentz transformations lead directly to physical components, and this case the speed of light is c. Finally e show that both scenarios, de-synchronization Einstein theory and synchronized theory, are all mathematically equivalent by means of Clifford Algebra Transformations.

R. de Oliveira; S. J. da Silva; V. H. G. de Campos

2013-11-25

358

LU transformation invariant operators and LU transformation invariant  

E-print Network

We proposed a concept of LU transformation invariant operators. By using this operator, arbitrary multi-qubit states LU transformation invariant and SLOCC invariant could be easily obtained. And we find that presences two kinds of invariant operators and corresponding invariants. One kind of operators yields LU invariants and the other operators results in SLOCC invariants. For three-qubit states, all independence LU transformation invariant are obtained. Furthermore, by this system method, arbitrary multi-qubit states invariants can be given.

Xin-wei Zha; Chun-min Zhang

2007-02-06

359

Genetic transformation of Ascochyta rabiei using Agrobacterium -mediated transformation  

Microsoft Academic Search

In order to study pathogenic mechanisms of the plant pathogen Ascochyta rabiei, conditions for efficient transformation using Agrobacterium-mediated transformation were investigated. Hygromycin B resistance (hph) was superior to geneticin resistance (nptII) for selecting transformants, and the hph gene was more efficiently expressed by the Aspergillus nidulans\\u000a trpC promoter than by the Cauliflower mosaic virus 35S promoter CaMV35S. Co-cultivation on solid

David White; Weidong Chen

2006-01-01

360

Transformation of Endomyces fibuliger based on its gene for orotidine-5?-phosphate decarboxylase  

Microsoft Academic Search

Endomyces fibuliger is a yeast used in the production of Chinese rice wine. It secretes enzymes such as glucoamylase, ?-amylase and acid protease. Very little is known of the genetics of E. fibuliger. In order to develop a transformation system for this yeast, orotidine-5?-phosphate decarboxylase mutant strains were obtained and characterized. Transformation of the E. fibuliger ura3 mutant F1 with

W. Y Ngan; B. H Nga; D Pridmore; B Mollet; H. M Tan

2000-01-01

361

Rosmarinic acid.  

PubMed

Rosmarinic acid is an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. It is commonly found in species of the Boraginaceae and the subfamily Nepetoideae of the Lamiaceae. However, it is also found in species of other higher plant families and in some fern and hornwort species. Rosmarinic acid has a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The presence of rosmarinic acid in medicinal plants, herbs and spices has beneficial and health promoting effects. In plants, rosmarinic acid is supposed to act as a preformed constitutively accumulated defence compound. The biosynthesis of rosmarinic acid starts with the amino acids L-phenylalanine and L-tyrosine. All eight enzymes involved in the biosynthesis are known and characterised and cDNAs of several of the involved genes have been isolated. Plant cell cultures, e.g. from Coleus blumei or Salvia officinalis, accumulate rosmarinic acid in amounts much higher than in the plant itself (up to 36% of the cell dry weight). For this reason a biotechnological production of rosmarinic acid with plant cell cultures has been proposed. PMID:12482446

Petersen, Maike; Simmonds, Monique S J

2003-01-01

362

Fourier transform and related integral transforms in superspace  

E-print Network

In this paper extensions of the classical Fourier, fractional Fourier and Radon transforms to superspace are studied. Previously, a Fourier transform in superspace was already studied, but with a different kernel. In this work, the fermionic part of the Fourier kernel has a natural symplectic structure, derived using a Clifford analysis approach. Several basic properties of these three transforms are studied. Using suitable generalizations of the Hermite polynomials to superspace (see [H. De Bie, F. Sommen, Hermite and Gegenbauer polynomials in superspace using Clifford analysis, J. Phys. A 40 (2007) 10441-10456]) an eigenfunction basis for the Fourier transform is constructed.

Hendrik De Bie

2008-05-13

363

Imaging Fourier Transform Spectrometer  

SciTech Connect

The operating principles of an Imaging Fourier Transform Spectrometer (IFTS) are discussed. The advantages and disadvantages of such instruments with respect to alternative imaging spectrometers are discussed. The primary advantages of the IFTS are the capacity to acquire more than an order of magnitude more spectral channels than alternative systems with more than an order of magnitude greater etendue than for alternative systems. The primary disadvantage of IFTS, or FTS in general, is the sensitivity to temporal fluctuations, either random or periodic. Data from the IRIFTS (ir IFTS) prototype instrument, sensitive in the infrared, are presented having a spectral sensitivity of 0.01 absorbance units, a spectral resolution of 6 cm{sup {minus}1} over the range 0 to 7899 cm{sup {minus}1}, and a spatial resolution of 2.5 mr.

Bennett, C.L.; Carter, M.R.; Fields, D.J.; Hernandez, J.

1993-04-14

364

Transforming Cities With Transit  

NSDL National Science Digital Library

How are cities transformed by the creation of new transit lines? How can existing transit lines be modified to create new land use opportunities for housing and commercial properties? These subjects are covered by a 172-page conference edition of a forthcoming paper from the World Bank. The paper was authored by Hiroaki Suzuki, Robert Cervero, and Kanako Iuchi. Visitors will note that the work focuses on "identifying barriers to and opportunities for effective coordination of transport infrastructure and urban development." The work takes on a number of global best practices of transit-oriented metropolises that have direct relevance to cities in developing countries and offers both analysis and suggestions for future projects. Sections here include "Lessons from Sustainable Transit-Oriented Cities," "Integrating Transit and Urban Development in Cities in the Developing World," and "Toward Sustainable Urban Futures."

Cervero, Robert.; Iuchi, Kanako; Suzuki, Hiroaki

365

Improving facilities, transforming attitudes.  

PubMed

Providing an effective healing environment for patients facing a wide range of mental health issues, while balancing their needs with security, safety, and affordability considerations, will be key area of focus at this year's Design in Mental Health (DIMH) conference and exhibition, taking place from 13-14 May at the National Motorcycle Museum in Bickenhill near Solihull. As HEJ editor, Jonathan Baillie, reports, conference speakers will include the director of estates and new business at the Priory Group; the chief executive of mental health charity, Mind; architects and designers with substantial mental healthcare experience; top academics, and service-users--all with their own perspective on the 2014 conference theme, 'Improving facilities, transforming attitudes'. PMID:24783329

Baillie, Jonathan

2014-04-01

366

Infrared transform spectral imager  

NASA Astrophysics Data System (ADS)

A dispersive transform spectral imager named FAROS (FAst Reconfigurable Optical Sensor) has been developed for high frame rate, moderate-to-high resolution hyperspectral imaging. A programmable digital micromirror array (DMA) modulator makes it possible to adjust spectral, temporal and spatial resolution in real time to achieve optimum tradeoff for dynamic monitoring requirements. The system's F/2.8 collection optics produces diffraction-limited images in the mid-wave infrared (MWIR) spectral region. The optical system is based on a proprietary dual-pass Offner configuration with a single spherical mirror and a confocal spherical diffraction grating. FAROS fulfills two functions simultaneously: one output produces two-dimensional polychromatic imagery at the full focal plane array (FPA) frame rate for fast object acquisition and tracking, while the other output operates in parallel and produces variable-resolution spectral images via Hadamard transform encoding to assist in object discrimination and classification. The current version of the FAROS spectral imager is a multispectral technology demonstrator that operates in the MWIR with a 320 x 256 pixel InSb FPA running at 478 frames per second resulting in time resolution of several tens of milliseconds per hypercube. The instrument has been tested by monitoring small-scale rocket engine firings in outdoor environments. The instrument has no macro-scale moving parts, and conforms to a robust, small-volume and lightweight package, suitable for integration with small surveillance vehicles. The technology is also applicable to multispectral/hyperspectral imaging applications in diverse areas such as atmospheric contamination monitoring, agriculture, process control, and biomedical imaging, and can be adapted for use in any spectral domain from the ultraviolet (UV) to the LWIR region.

Vujkovic-Cvijin, Pajo; Lee, Jamine; Gregor, Brian; Goldstein, Neil; Panfili, Raphael; Fox, Marsha

2012-10-01

367

Electrolytic phase transformation actuators  

NASA Astrophysics Data System (ADS)

The emerging field of materials-based actuation continues to be the focus of considerable research due to its inherent scalability and its promise to drive devices in ways that cannot be realized with conventional mechanical actuator strategies. Current approaches include electrochemically responsive conducting polymers, capacitance-driven carbon nanotubes actuators, pH responsive hydrogels, ionic polymer metal composites, electric field responsive elastomers, and field-driven electrostrictive polymers. However, simple electrochemical processes that lead to phase transformations, particularly from liquid to gas, have been virtually ignored. Although a few specialized applications have been proposed, the nature of the reactions and their implication for design, performance, and widespread applicability have not been addressed. Herein we report an electrolytic phase transformation (EPT) actuator, a device capable of producing strains surpassing 136,000% and stresses beyond 200 MPa. These performance characteristics are several orders of magnitude greater than those reported for other materials and could potentially compete with existing commercial hydraulic systems. Furthermore, unlike other materials-based systems that rely on bimorph structures to translate infinitesimally small volume changes into observable deflections, this device can direct all of its output towards linear motion. We show here that an unoptimized actuator prototype can produce volume and pressure changes close to the theoretically predicted values, with maximum stress (70 kPa) limited only by the mechanical strength of the apparatus. Expansion is very rapid and scales with applied current density. Retraction depends on the catalytic nature of the electrode, and state-of-the-art commercial fuel cell electrodes should allow rates surpassing 0.9 mL's-1.cm-2 and 370 kPa's-1.cm-2. We anticipate that this approach will provide a new direction for producing scalable, low-weight, high performance actuators that will be useful in a broad range of applications.

Cameron, Colin G.; Freund, Michael S.

2003-07-01

368

7 transformations of leadership.  

PubMed

Most developmental psychologists agree that what differentiates one leader from another is not so much philosophy of leadership, personality, or style of management. Rather, it's internal "action logic"--how a leader interprets the surroundings and reacts when his or her power or safety is challenged. Relatively few leaders, however, try to understand their action logic, and fewer still have explored the possibility of changing it. They should, because leaders who undertake this voyage of personal understanding and development can transform not only their own capabilities but also those of their companies. The authors draw on 25 years of consulting experience and collaboration with psychologist Susanne Cook-Greuter to present a typology of leadership based on the way managers personally make sense of the world around them. Rooke and Torbert classify leaders into seven distinct actionlogic categories: Opportunists, Diplomats, Experts, Achievers, Individualists, Strategists, and Alchemists-the first three associated with below-average performance, the latter four with medium to high performance. These leadership styles are not fixed, the authors say, and executives who are willing to work at developing themselves and becoming more self-aware can almost certainly move toward one of the more effective action logics. A Diplomat, for instance, can succeed through hard work and self-reflection at transforming himself into a Strategist. Few people may become Alchemists, but many will have the desire and potential to become Individualists and Strategists. Corporations that help their executives and leadership teams to examine their action logics can reap rich rewards. PMID:15807040

Rooke, David; Torbert, William R

2005-04-01

369

Transformation plasticity in ductile solids  

SciTech Connect

Research has addressed the role of martensitic transformation plasticity in the enhancement of toughness in high-strength austenitic steels, and the enhancement of formability in multiphase low-alloy sheet steels. In the austenitic steels, optimal processing conditions have been established to achieve a significant increase in strength level, in order to investigate the interaction of strain-induced transformation with the microvoid nucleation and shear localization mechanisms operating at ultrahigh strength levels. The stress-state dependence of transformation and fracture mechanisms has been investigated in model alloys, comparing behavior in uniaxial tension and blunt-notch tension specimens. A numerical constitutive model for transformation plasticity has been reformulated to allow a more thorough analysis of transformation/fracture interactions. Processing of a new low alloy steel composition has been optimized to stabilize retained austenite by isothermal bainitic transformation after intercritical annealing. Preliminary results show a good correlation of uniform ductility with the austenite amount and stability.

Olson, G.B.

1993-02-01

370

Alchemical attention: Shaw's transformational matrix  

E-print Network

ideas. I argue for the thesis that Shaw dramatically bodies forth the idea that a human being may be transformed through the agency of an inner female principle, a principle that itself bridges the chasm between the lower nature and the higher nature... sacred idea, intended not to explain transformation but rather to catalyze, guide, and support it. Concluding thoughts concerning the nature of this transformation are presented in chapter nine. TABLE OF CONTENTS Page ABSTRACT TABLE OF CONTENTS...

Bryant, Gary Richard

2012-06-07

371

Cereal transformation through particle bombardment  

NASA Technical Reports Server (NTRS)

The review focuses on experiments that lead to stable transformation in cereals using microprojectile bombardment. The discussion of biological factors that affect transformation examines target tissues and vector systems for gene transfer. The vector systems include reporter genes, selectable markers, genes of agronomic interest, and vector constructions. Other topics include physical parameters that affect DNA delivery, selection of stably transformed cells and plant regeneration, and analysis of gene expression and transmission to the progeny.

Casas, A. M.; Kononowicz, A. K.; Bressan, R. A.; Hasegawa, P. M.; Mitchell, C. A. (Principal Investigator)

1995-01-01

372

Genetic transformation of Vitreoscilla sp  

Microsoft Academic Search

Of all the methods customarily used to transform E. coli we found only electroporation to be effective for transformation of the Gram-negative bacterium Vitreoscilla, yielding 5.105 transformants\\/?g of plasmid DNA. The conditions used were close to those described for E. coli. E. coli plasmids are stably maintained in Vitreoscilla. This is the first report of exogenous DNA transfer in Vitreoscilla

Naveen K. Navani; Meenal A. Joshi; Kanak L. Dikshit

1996-01-01

373

Discrete Pulse Transform of Images  

Microsoft Academic Search

\\u000a The Discrete Pulse Transform (DPT) of images is defined by using a new class of LULU operators on multidimensional arrays.\\u000a This transform generalizes the DPT of sequences and replicates its essential properties, e.g. total variation preservation.\\u000a Furthermore, the discrete pulses in the transform capture the contrast in the original image on the boundary of their supports.\\u000a Since images are perceived

Roumen Anguelov; Inger Fabris-rotelli

2008-01-01

374

Continuous boundary local Fourier transform  

NASA Astrophysics Data System (ADS)

The Local Fourier Transform (LFT) provides a nice tool for concentrating both a signal and its Fourier transform. But there are certain properties of this algorithm that make it unattractive for various applications. In this paper, some of these disadvantages are explored, and a new approach to localized Fourier analysis is proposed, the continuous boundary local Fourier transform (CBLFT), which attempts to correct some of these shortcomings. Results ranging from segmentation to representation cost to compression are also presented.

Larson, Brons M.; Saito, Naoki

2001-12-01

375

Tree Transducer Composition Program Transformation  

E-print Network

a specific transformation for the elimination of inter� mediate results (for so called deforestation . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Deforestation and accumulating parameters . . . . . . . . . . . . . .

Eckmiller, Rolf

376

Algorithm For Integer Cosine Transforms  

NASA Technical Reports Server (NTRS)

Algorithm computes coefficients of integer cosine transforms, containing only integer coefficients approximately proportional to floating-point coefficients of discrete cosine transforms. Used in compression of image data in blocks of N x N pixels, discrete cosine transforms involve large amounts of computation, typically amounting to 80 percent of computational load in data-compression scheme. In constructing integer approximations, competing requirements are to obtain data-compression and data-decompression performances comparable to those of corresponding descrete cosine transforms while taking advantage of simplicity afforded by integer arithmetic to reduce complexity and amount of computation.

Pollara, Fabrizio; Cheung, Kar-Ming; Shahshahani, Mehrdad

1994-01-01

377

Versatile Transformation System That Is Applicable to both Multiple Transgene Expression and Gene Targeting for Thraustochytrids  

PubMed Central

A versatile transformation system for thraustochytrids, a promising producer for polyunsaturated fatty acids and fatty acid-derived fuels, was established. G418, hygromycin B, blasticidin, and zeocin inhibited the growth of thraustochytrids, indicating that multiple selectable marker genes could be used in the transformation system. A neomycin resistance gene (neor), driven with an ubiquitin or an EF-1? promoter-terminator from Thraustochytrium aureum ATCC 34304, was introduced into representatives of two thraustochytrid genera, Aurantiochytrium and Thraustochytrium. The neor marker was integrated into the chromosomal DNA by random recombination and then functionally translated into neor mRNA. Additionally, we confirmed that another two genera, Parietichytrium and Schizochytrium, could be transformed by the same method. By this method, the enhanced green fluorescent protein was functionally expressed in thraustochytrids. Meanwhile, T. aureum ATCC 34304 could be transformed by two 18S ribosomal DNA-targeting vectors, designed to cause single- or double-crossover homologous recombination. Finally, the fatty acid ?5 desaturase gene was disrupted by double-crossover homologous recombination in T. aureum ATCC 34304, resulting in an increase of dihomo-?-linolenic acid (C20:3n-6) and eicosatetraenoic acid (C20:4n-3), substrates for ?5 desaturase, and a decrease of arachidonic acid (C20:4n-6) and eicosapentaenoic acid (C20:5n-3), products for the enzyme. These results clearly indicate that a versatile transformation system which could be applicable to both multiple transgene expression and gene targeting was established for thraustochytrids. PMID:22344656

Sakaguchi, Keishi; Matsuda, Takanori; Kobayashi, Takumi; Ohara, Jun-ichiro; Hamaguchi, Rie; Abe, Eriko; Nagano, Naoki; Hayashi, Masahiro; Ueda, Mayumi; Honda, Daiske; Okita, Yuji; Taoka, Yousuke; Sugimoto, Shinichi; Okino, Nozomu

2012-01-01

378

Spectrophotometric, Fourier transform infrared spectroscopic and theoretical studies of the charge-transfer complexes between methyldopa [(S)-2 amino-3-(3,4-dihydroxyphenyl)-2-methyl propanoic acid] and the acceptors (chloranilic acid, o-chloranil and dichlorodicyanobenzoquinone) in acetonitrile and their thermodynamic properties  

NASA Astrophysics Data System (ADS)

Methyldopa is a much used antihypertensive drug. It is the subject matter of study mostly for the determination and estimation of methyldopa in pharmaceutical properties. These considerations led us to study the charge-transfer interactions between methyldopa, a centrally acting antihypertensive agent of limited use with the known acceptors like o-chloranil (o-ClN), chloranilic acid (ClA) and dichlorodicyanobenzoquinone (DDQ). Methyldopa (MDP) formed beautifully colored complexes (having absorption maxima at 581 nm and 368 nm; 519 nm; 583.5 nm, 547 nm and 346 nm, respectively) with the acceptors mentioned before. The physico-chemical properties of the complexes were studied using UV-visible spectrophotometry and FTIR measurements. The composition, the accurate association constants and thermodynamics of the complexes were determined spectrophotometrically. Attempts were made to interpret the thermodynamics of complexes in terms of IDV, EAV and h?CT. Solid CT complexes between MDP + o-ClN, MDP + ClA and MDP + DDQ were prepared and FTIR spectra of the complexes were studied. The energies h?CT of the charge-transfer complexes and vertical ionization potential IDV of methyldopa were compared with the theoretical values of h?CT obtained from HOMO and LUMO of the donors and acceptors calculated using Density Function Theory utilizing different basis sets. The agreement between the results can be regarded to be reasonable. Oscillator strengths and dipole strengths of the complexes were determined theoretically and experimentally and the limitations of the calculations were outlined.

Sharma, K.; Sharma, S. P.; Lahiri, S. C.

379

Characterizations of Iron Sulfides and Iron Oxides Associated with Acid Mine Drainage.  

E-print Network

??I evaluated mineralogical transformations of Fe induced by activities of an acid-tolerant sulfate reducing bacterium, Desulfosporosinus sp. GBSRB4.2 under geochemical conditions associated with acid mine… (more)

Bertel, Douglas E.

2011-01-01

380

Acid rain  

SciTech Connect

This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

White, J.C. (Cornell University, Ithaca, NY (US))

1988-01-01

381

Tranexamic Acid  

MedlinePLUS

Tranexamic acid comes as a tablet to take by mouth. It is usually taken with or without food three times a day for up to 5 days during monthly menstruation. You should begin taking this medication each month when your period starts. Do not take tranexamic acid when you do not have a period. Take ...

382

Acid Rain  

Microsoft Academic Search

Measurements of the acidity of rain and snow reveal that in parts of the eastern U.S. and of western Europe precipitation has changed from a nearly neutral solution 200 years ago to a dilute solution of sulfuric and nitric acids today. The trend is a result of the emission of sulfur and nitrogen oxides to the atmosphere accompanying the rise

Gene E. Likens; Richard F. Wright; James N. Galloway; Thomas J. Butler

1979-01-01

383

Acid test  

NSDL National Science Digital Library

Baking soda can be used as an indicator of how much acid a substance contains. Lemons and limes have more acid in them than grapefruits and oranges. Indophenol can be used as an indicator of how much vitamin C is in a substance.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-06

384

Domoic Acid  

NSDL National Science Digital Library

This online student report discusses the chemistry of domoic acid, a biotoxin that is produced by the diatom Psuedo-nitzschia and associated with Amnesiac Shellfish Poisoning (ASP). In addition to a descriptive summary and images, the report links to other areas of interest related to domoic acid poisoning including signs and symptoms, modes of action, and treatment.

Bailey, Christina; Kohlen, Corinne

2010-02-10

385

Spectrophotometric, Fourier transform infrared spectroscopic and theoretical studies of the charge-transfer complexes between methyldopa [(S)-2 amino-3-(3,4-dihydroxyphenyl)-2-methyl propanoic acid] and the acceptors (chloranilic acid, o-chloranil and dichlorodicyanobenzoquinone) in acetonitrile and their thermodynamic properties.  

PubMed

Methyldopa is a much used antihypertensive drug. It is the subject matter of study mostly for the determination and estimation of methyldopa in pharmaceutical properties. These considerations led us to study the charge-transfer interactions between methyldopa, a centrally acting antihypertensive agent of limited use with the known acceptors like o-chloranil (o-ClN), chloranilic acid (ClA) and dichlorodicyanobenzoquinone (DDQ). Methyldopa (MDP) formed beautifully colored complexes (having absorption maxima at 581 nm and 368 nm; 519 nm; 583.5 nm, 547 nm and 346 nm, respectively) with the acceptors mentioned before. The physico-chemical properties of the complexes were studied using UV-visible spectrophotometry and FTIR measurements. The composition, the accurate association constants and thermodynamics of the complexes were determined spectrophotometrically. Attempts were made to interpret the thermodynamics of complexes in terms of I(D)(V), E(A)(V) and h?(CT). Solid CT complexes between MDP+o-ClN, MDP+ClA and MDP+DDQ were prepared and FTIR spectra of the complexes were studied. The energies h?(CT) of the charge-transfer complexes and vertical ionization potential I(D)(V) of methyldopa were compared with the theoretical values of h?(CT) obtained from HOMO and LUMO of the donors and acceptors calculated using Density Function Theory utilizing different basis sets. The agreement between the results can be regarded to be reasonable. Oscillator strengths and dipole strengths of the complexes were determined theoretically and experimentally and the limitations of the calculations were outlined. PMID:22446770

Sharma, K; Sharma, S P; Lahiri, S C

2012-06-15

386

Asparagusic acid.  

PubMed

Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for ?-lipoic acid in ?-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

Mitchell, Stephen C; Waring, Rosemary H

2014-01-01

387

Amino Acid-Derived Enaminones  

PubMed Central

A new reaction for the preparation of enaminones has been discovered. This method employs ?-amino acids as starting materials to allow diversification as well as incorporation of chirality. The ?-amino acids, once converted to ynones, are readily cyclized to the desired six membered enaminone via a two-step, one pot protocol. Although disguised as a 6-endo-dig cyclization, the reagents employed in the transformation play a direct role in bond making and bond breaking, thus changing the mode of addition. PMID:16819843

Turunen, Brandon J.; Georg, Gunda I.

2008-01-01

388

Coordinate Transformations in Object Recognition  

ERIC Educational Resources Information Center

A basic problem of visual perception is how human beings recognize objects after spatial transformations. Three central classes of findings have to be accounted for: (a) Recognition performance varies systematically with orientation, size, and position; (b) recognition latencies are sequentially additive, suggesting analogue transformation

Graf, Markus

2006-01-01

389

Lightning Protection for Distribution Transformers  

Microsoft Academic Search

This paper presents a five year history of the results of lightning arrester protection for distribution transformers in New England where the normal ground electrode resistance is much higher than in most other parts of this country. The experience shows that the trouble rate of the protected transformers has consistently been materially less than that of those not protected, notwithstanding

T. H. Haines; C. A. Corney

1932-01-01

390

Conformal Transformations and Space Travel  

Microsoft Academic Search

Conformal transformations are applied to the motion of a space ship experiencing a constant acceleration. The role of proper time is interpreted in terms of atomic periods, and the relationship between the conformal transformations and the general theory of relativity is clarified.

Suraj N. Gupta

1961-01-01

391

Travel and Adult Transformative Learning  

ERIC Educational Resources Information Center

This phenomenological research study examines the lived experience of individual adult transformation in the context of travel. Adults throughout history have experienced profound personal and perception changes as a result of significant travel events. Transformative learning occurs through experience, crisis, and reflection, all of which are…

Lindstrom, Steven K.

2011-01-01

392

Transformative Learning: Mutinous Thoughts Revisited  

ERIC Educational Resources Information Center

The author finds himself rereading an article he wrote several years ago, in which he questioned transformative learning. He recalls some of his reasons for writing the article, and considers his present position. He reflects on the understanding of consciousness that underlies much of the literature on transformative learning, and compares it…

Newman, Michael

2014-01-01

393

Transformation of encapsulated Streptococcus pneumoniae.  

PubMed Central

We describe the high-efficiency transformation of several virulent, encapsulated isolates of Streptococcus pneumoniae. Transformation was effected by the induction of competence with competence factor and was apparently the result both of inducing noncompetent recipients and overcoming the inhibition imposed by the capsule. PMID:3782044

Yother, J; McDaniel, L S; Briles, D E

1986-01-01

394

Towards Transformative Leadership in Education  

ERIC Educational Resources Information Center

This article argues that an educational organization's type of leadership will to a very large extent determine the quality of personal transformation it instigates among its stakeholders. Focusing on the importance of transformative leadership, such leadership will be viewed as a critical and collaborative process in which school-based…

van Oord, Lodewijk

2013-01-01

395

Student Services Revitalization/Transformation  

ERIC Educational Resources Information Center

Over a two year period, a multidisciplinary team developed and implemented a plan to transform the delivery of student services at George Brown College in Toronto. It was a plan that called upon the College to fundamentally overhaul student services, but more importantly, to transform the service culture at the College through the students'…

Pipitone, Brenda; Poirer, Wayne

2011-01-01

396

Transformational Grammar and Cognitive Psycholinguistics.  

ERIC Educational Resources Information Center

An overview of Noam Chomsky's theories about transformational grammar and phonology is given. Since Chomsky was interested in characterizing what it is to know a language, the ways in which we demonstrate knowledge of our native language are discussed in detail. Particular emphasis is placed on describing how the transformational approach actually…

Lester, Mark

1973-01-01

397

Simplified Relativistic Force Transformation Equation.  

ERIC Educational Resources Information Center

A simplified relativistic force transformation equation is derived and then used to obtain the equation for the electromagnetic forces on a charged particle, calculate the electromagnetic fields due to a point charge with constant velocity, transform electromagnetic fields in general, derive the Biot-Savart law, and relate it to Coulomb's law.…

Stewart, Benjamin U.

1979-01-01

398

Real Time Pyramid Transform Architecture  

NASA Astrophysics Data System (ADS)

This paper describes an architecture for creating pyramid transforms of real time video images. A powerful preprocessor can be designed with this architecture by representing the image data in a form most suitable for the application. The Burt pyramid algorithm [1], an efficient method for transforming video images into hierarchical representation, is an example of an effective transform. A programmable version of such a preprocessor, occupying two Multibus* boards, was built at low cost using available hardware. This unit can perform the basic pyramid trans-form on 256 x 240 images in real time. More complex and/or multiple transforms can be performed at reduced data rate by passing data through the unit several times, or can be performed in real time by passing data through multiple units. Because the preprocessor is programmable, the system is easily configured to perform several different pyramid transforms, or the appropriate inverse transforms. Algorithms can be developed to reduce edge effects by modifying the edges of the image before applying the transform. The preprocessor can be programmed to insert time delays into the system, which is useful in the display of the results. Image processing system, design can be simplified by using the preprocessor to significantly reduce the computational requirements of the main processor. The proposed architecture, suitable for system integration, could lead to the availability of low cost, efficient image processing systems.

van der Wal, Gooitzen S.; Sinniger, Joseph O...

1985-12-01

399

Transformation of Wave Height Distribution  

Microsoft Academic Search

Earlier models of random wave transformation are reviewed in the first section. Then the transformation of waves, including dissipation due to breaking and bottom friction, is described by an energy flux balance model. The wave height pdf of all waves (broken and unbroken) is shown by the field data to be well described by the Rayleigh distribution everywhere. The observed

Edward B. Thornton; R. T. Guza

1983-01-01

400

Database Transformations for Biological Applications  

SciTech Connect

The goal of this project was to develop tools to facilitate data transformations between heterogeneous data sources found throughout biomedical applications. Such transformations are necessary when sharing data between different groups working on related problems as well as when querying data spread over different databases, files and software analysis packages.

Overton, C.; Davidson, S. B.; Buneman, P.; Tannen, V.

2001-04-11

401

Vinyl hydrogen acidities of two stereoisomers.  

PubMed

The gas-phase acidities of the vinyl hydrogens of cis- and trans-2-butene were measured by the silane kinetic method in a Fourier-transform ion cyclotron resonance spectrometer. The acidities of ethene and the secondary vinyl hydrogen of propene were measured by the same method. The method was calibrated using the known acidities of methane and benzene. The vinyl hydrogens of trans-2-butene are more acidic than the vinyl hydrogens of cis-2-butene by 4.5 kcal/mol; the acidities of ethene and the secondary vinyl hydrogen of propene are between those of the two butenes. The acidity of cis-2-butene is 409 +/- 2 kcal/mol, and the acidity of trans-2-butene is 405 +/- 2 kcal/mol. Density functional theory calculations are in good agreement with the experiments. The results are discussed in terms of steric interactions, polarizabilities, dipole-dipole interactions, and charge-dipole interactions. PMID:17256827

Walthall, David A; Brauman, John I

2007-02-22

402

Fast Numerical Nonlinear Fourier Transforms  

E-print Network

The nonlinear Fourier transform, which is also known as the forward scattering transform, decomposes a periodic signal into nonlinearly interacting waves. In contrast to the common Fourier transform, these waves no longer have to be sinusoidal. Physically relevant waveforms are often available for the analysis instead. The details of the transform depend on the waveforms underlying the analysis, which in turn are specified through the implicit assumption that the signal is governed by a certain evolution equation. For example, water waves generated by the Korteweg-de Vries equation can be expressed in terms of cnoidal waves. Light waves in optical fiber governed by the nonlinear Schr\\"dinger equation (NSE) are another example. Nonlinear analogs of classic problems such as spectral analysis and filtering arise in many applications, with information transmission in optical fiber, as proposed by Yousefi and Kschischang, being a very recent one. The nonlinear Fourier transform is eminently suited to address them ...

Wahls, Sander

2014-01-01

403

Inversion of the star transform  

NASA Astrophysics Data System (ADS)

We define the star transform as a generalization of the broken ray transform introduced by us in previous work. The advantages of using the star transform include the possibility to reconstruct the absorption and the scattering coefficients of the medium separately and simultaneously (from the same data) and the possibility to utilize scattered radiation which, in the case of conventional x-ray tomography, is discarded. In this paper, we derive the star transform from physical principles, discuss its mathematical properties and analyze numerical stability of inversion. In particular, it is shown that stable inversion of the star transform can be obtained only for configurations involving odd number of rays. Several computationally-efficient inversion algorithms are derived and tested numerically.

Zhao, Fan; Schotland, John C.; Markel, Vadim A.

2014-10-01

404

Optimal oscillation-center transformations  

SciTech Connect

A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed.

Dewar, R.L.

1984-08-01

405

MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform  

Microsoft Academic Search

A multiple sequence alignment program, MAFFT, has been developed. The CPU time is drastically reduced as compared with existing methods. MAFFT includes two novel techniques. (i) Homo- logous regions are rapidly identified by the fast Fourier transform (FFT), in which an amino acid sequence is converted to a sequence composed of volume and polarity values of each amino acid resi-

Kazutaka Katoh; Kazuharu Misawa; Kei-ichi Kum; Takashi Miyata

2002-01-01

406

para-hydroxybenzoate as an intermediate in the anaerobic transformation of phenol to benzoate.  

PubMed

Anaerobic phenol transformation was studied using a consortium which transformed phenol to benzoate without complete mineralization of benzoate. Products of monofluorophenol transformation indicated para-carboxylation. Phenol and benzoate were detected during para-hydroxybenzoate (p-OHB) degradation. p-OHB was detected in phenol-transforming cultures containing 6-hydroxynicotinic acid (6-OHNA), a structural analogue of p-OHB, or at elevated initial concentrations of phenol (greater than or equal to 5 mM), or benzoate (greater than or equal to 10 mM). PMID:2040433

Genthner, B R; Townsend, G T; Chapman, P J

1991-03-01

407

Acid Rain  

NSDL National Science Digital Library

Due to the presence of dissolved gases such as carbon dioxide, rainfall is naturally acidic. The release of other gases and chemicals such as sulfur dioxide during the combustion of coal and oil can cause rainfall to become even more acidic, sometimes to the point of toxicity. In this activity, students will measure the pH of local rainfall to see what effect these gases have in their region. They will also check an online resource to see how the releases of acid rain-causing chemicals have varied over the past 20 years, and answer questions about the information they uncover.

Fox, Chris

408

Acid fog  

SciTech Connect

Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

Hileman, B.

1983-03-01

409

Recombinant microorganisms for increased production of organic acids  

DOEpatents

Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

Yi, Jian (East Lansing, MI); Kleff, Susanne (East Lansing, MI); Guettler, Michael V. (Holt, MI)

2012-02-21

410

Recombinant microorganisms for increased production of organic acids  

DOEpatents

Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

Yi, Jian; Kleff, Susanne; Guettler, Michael V

2013-04-30

411

Stable transformation of petunia plastids.  

PubMed

Plastid transformation results in stably expressed foreign genes, which for most Angiosperms are largely excluded from sperm cells, thereby greatly reducing the risk of foreign gene spread through pollen. Prior to this work, fertile plastid transformants were restricted to tobacco, tomato and Lesquerella. Application of plastid engineering in the important floriculture industry requires the development of stable plastid transformation in a major ornamental plant species such as Petunia hybrida. Here we describe the successful isolation of fertile and stable plastid transformants in a commercial cultivar of P. hybrida (var. Pink Wave). Plastid targeting regions from tobacco were used to integrate aadA and gusA between the accD and rbcL genes of P. hybrida plastid DNA following particle bombardment of leaves. For three spectinomycin and streptomycin resistant lines, DNA blot analysis confirmed transgene integration into plastid DNA and homoplasmy. Maternal inheritance and homoplasmy resulted in 100% transmission of spectinomycin resistance to progeny after selfing. Plastid transformants expressed the gusA gene uniformly within leaves and to comparable levels in all three lines. Insertion of trait genes in place of gusA coding sequences enables immediate applications of our plastid transformation vector. Establishment of plastid transformation in P. hybrida facilitates a safe and reliable use of this important ornamental plant for research and plant biotechnology. PMID:15672833

Zubkot, Mikhajlo K; Zubkot, Elena I; van Zuilen, Karen; Meyer, Peter; Day, Anil

2004-12-01

412

Transform coding for space applications  

NASA Technical Reports Server (NTRS)

Data compression coding requirements for aerospace applications differ somewhat from the compression requirements for entertainment systems. On the one hand, entertainment applications are bit rate driven with the goal of getting the best quality possible with a given bandwidth. Science applications are quality driven with the goal of getting the lowest bit rate for a given level of reconstruction quality. In the past, the required quality level has been nothing less than perfect allowing only the use of lossless compression methods (if that). With the advent of better, faster, cheaper missions, an opportunity has arisen for lossy data compression methods to find a use in science applications as requirements for perfect quality reconstruction runs into cost constraints. This paper presents a review of the data compression problem from the space application perspective. Transform coding techniques are described and some simple, integer transforms are presented. The application of these transforms to space-based data compression problems is discussed. Integer transforms have an advantage over conventional transforms in computational complexity. Space applications are different from broadcast or entertainment in that it is desirable to have a simple encoder (in space) and tolerate a more complicated decoder (on the ground) rather than vice versa. Energy compaction with new transforms are compared with the Walsh-Hadamard (WHT), Discrete Cosine (DCT), and Integer Cosine (ICT) transforms.

Glover, Daniel

1993-01-01

413

ACID RAIN  

EPA Science Inventory

Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

414

Natural Transformation of Gallibacterium anatis  

PubMed Central

Gallibacterium anatis is a pathogen of poultry. Very little is known about its genetics and pathogenesis. To enable the study of gene function in G. anatis, we have established methods for transformation and targeted mutagenesis. The genus Gallibacterium belongs to the Pasteurellaceae, a group with several naturally transformable members, including Haemophilus influenzae. Bioinformatics analysis identified G. anatis homologs of the H. influenzae competence genes, and natural competence was induced in G. anatis by the procedure established for H. influenzae: transfer from rich medium to the starvation medium M-IV. This procedure gave reproducibly high transformation frequencies with G. anatis chromosomal DNA and with linearized plasmid DNA carrying G. anatis sequences. Both DNA types integrated into the G. anatis chromosome by homologous recombination. Targeted mutagenesis gave transformation frequencies of >2 × 10?4 transformants CFU?1. Transformation was also efficient with circular plasmid containing no G. anatis DNA; this resulted in the establishment of a self-replicating plasmid. Nine diverse G. anatis strains were found to be naturally transformable by this procedure, suggesting that natural competence is common and the M-IV transformation procedure widely applicable for this species. The G. anatis genome is only slightly enriched for the uptake signal sequences identified in other pasteurellaceaen genomes, but G. anatis did preferentially take up its own DNA over that of Escherichia coli. Transformation by electroporation was not effective for chromosomal integration but could be used to introduce self-replicating plasmids. The findings described here provide important tools for the genetic manipulation of G. anatis. PMID:22582057

Kristensen, Bodil M.; Sinha, Sunita; Boyce, John D.; Mell, Joshua C.; Redfield, Rosemary J.

2012-01-01

415

Natural transformation of Gallibacterium anatis.  

PubMed

Gallibacterium anatis is a pathogen of poultry. Very little is known about its genetics and pathogenesis. To enable the study of gene function in G. anatis, we have established methods for transformation and targeted mutagenesis. The genus Gallibacterium belongs to the Pasteurellaceae, a group with several naturally transformable members, including Haemophilus influenzae. Bioinformatics analysis identified G. anatis homologs of the H. influenzae competence genes, and natural competence was induced in G. anatis by the procedure established for H. influenzae: transfer from rich medium to the starvation medium M-IV. This procedure gave reproducibly high transformation frequencies with G. anatis chromosomal DNA and with linearized plasmid DNA carrying G. anatis sequences. Both DNA types integrated into the G. anatis chromosome by homologous recombination. Targeted mutagenesis gave transformation frequencies of >2 × 10(-4) transformants CFU(-1). Transformation was also efficient with circular plasmid containing no G. anatis DNA; this resulted in the establishment of a self-replicating plasmid. Nine diverse G. anatis strains were found to be naturally transformable by this procedure, suggesting that natural competence is common and the M-IV transformation procedure widely applicable for this species. The G. anatis genome is only slightly enriched for the uptake signal sequences identified in other pasteurellaceaen genomes, but G. anatis did preferentially take up its own DNA over that of Escherichia coli. Transformation by electroporation was not effective for chromosomal integration but could be used to introduce self-replicating plasmids. The findings described here provide important tools for the genetic manipulation of G. anatis. PMID:22582057

Kristensen, Bodil M; Sinha, Sunita; Boyce, John D; Bojesen, Anders M; Mell, Joshua C; Redfield, Rosemary J

2012-07-01

416

Acidic precipitation  

SciTech Connect

At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

Martin, H.C.

1987-01-01

417

Multi-dimensional real Fourier transform  

NASA Technical Reports Server (NTRS)

Four subroutines compute one-dimensional and multi-dimensional Fourier transforms for real data, multi-dimensional complex Fourier transforms, and multi-dimensional sine, cosine and sine-cosine transforms. Subroutines use Cooley-Tukey fast Fourier transform. In all but one-dimensional case, transforms are calculated in up to six dimensions.

Krogh, F. T.

1971-01-01

418

Materials and methods for efficient lactic acid production  

DOEpatents

The present invention provides derivatives of Escherichia coli constructed for the production of lactic acid. The transformed E. coli of the invention are prepared by deleting the genes that encode competing pathways followed by a growth-based selection for mutants with improved performance. These transformed E. coli are useful for providing an increased supply of lactic acid for use in food and industrial applications.

Zhou, Shengde; Ingram, Lonnie O'Neal; Shanmugam, Keelnatham T; Yomano, Lorraine; Grabar, Tammy B; Moore, Jonathan C

2013-04-23

419

DNA Uptake by Transformable Bacteria  

SciTech Connect

The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

Lacks, Sanford A.

1999-03-31

420

DNA UPTAKE BY TRANSFORMABLE BACTERIA  

SciTech Connect

The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

LACKS,S.A.

1999-09-07

421

Heat storage in alloy transformations  

NASA Technical Reports Server (NTRS)

The theory of eutectic transformation was examined to find guidelines to the best material combinations to examine. The heats of transformation were measured calorimetrically, and the volume changes of expanding solid mixtures and homogeneous liquid solutions, especially during the transformation between the two states at fixed temperature, were measured by changes in X-ray absorption. Heat flow models appropriate to storage in phase change materials were developed along with efficient calculating procedures so that the relative importance of the problems associated with energy storage density, heat conduction, and similar properties could be assessed.

Birchenall, C. E.; Gueceri, S. I.

1980-01-01

422

Spacecraft transformer and inductor design  

NASA Technical Reports Server (NTRS)

The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

Mclyman, W. T.

1977-01-01

423

Nucleic acid encoding TGF-. beta. and its uses  

SciTech Connect

This patent describes a method. It comprises: constructing a vector which includes nucleic acid encoding biologically active TGF-{beta}, transforming a host eukaryotic cell with the vector, culturing the transformed cell and recovering mature TGF-{beta} from the culture medium.

Derynck, R.M.A.; Goeddel, D.V.

1989-12-12

424

Calcium-based Lewis acid catalysts.  

PubMed

Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf?)?, Ca(OTf)?, CaF? and Ca[OCH(CF?)?]? have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids. PMID:23712417

Begouin, Jeanne-Marie; Niggemann, Meike

2013-06-17

425

Research on lead acid battery electrodes  

Microsoft Academic Search

The reactions and physical and molecular transformations that occur in lead acid battery plate active material during charge-discharge cycling have been studied under a DOE program to improve the lead acid battery for electric vehicle applications. Investigations included structural studies of PbO2 by X-ray\\/neutron diffraction, effects of cycling on capacity by pulsed vs unpulsed discharge, active material microstructure\\/plate capacity changes

A. C. Simon; S. M. Caulder; C. P. Wales; R. L. Jones

1982-01-01

426

Genetic transformation of oilseed rape ( Brassica napus ) by the Ri T-DNA of Agrobacterium rhizogenes and analysis of inheritance of the transformed phenotype  

Microsoft Academic Search

Genetically transformed repeseed (Brassica napus) roots were obtained by in vitro inoculation of excised stem segments with Agrobacterium rhizogenes. Axenic root organ clones were established and they exhibited a phenotype characteristic of transformed roots: rapid growth, reduced apical dominance and root plagiotropism. Stem regeneration was induced by exposing root fragments to 2,4-dichloroacetic acid (2,4-D) in liquid medium, followed by transfer

P. Guerche; L. Jouanin; D. Tepfer; G. Pelletier

1987-01-01

427

Anaerobic and aerobic transformation of TNT  

SciTech Connect

Most studies on the microbial metabolism of nitroaromatic compounds have used pure cultures of aerobic microorganisms. In many cases, attempts to degrade nitroaromatics under aerobic conditions by pure cultures result in no mineralization and only superficial modifications of the structure. However, mixed culture systems properly operated result in the transformation of 2,4,6-trinitrotoluene (TNT) and in some cases mineralization of TNT occurs. In this paper, the mixed culture system is described with emphasis on intermediates and the characteristics of the aerobic microbial process including the necessity for a co-substrate. The possibility of removing TNT under aerobic/anoxic conditions is described in detail. Another option for the biodegradation of TNT and nitroaromatics is under anaerobic, sulfate reducing conditions. In this instance, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. TNT under sulfate reducing conditions is reduced to triaminotoluene presumably by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of nitro groups from TNT is achieved by a series of reductive reactions with the formation of ammonia and toluene by Desulfovibrio sp. (B strain). These metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. The data supporting the anaerobic transformation of TNT under different growth condition are reviewed in this report.

Kulpa, C.F. [Univ. of Notre Dame, IN (United States). Dept. of Biological Sciences; Boopathy, R.; Manning, J. [Argonne National Lab., IL (United States). Environmental Research Div.

1996-12-31

428

Transforming a Community through Research.  

ERIC Educational Resources Information Center

In 1945, the Conrad (Montana) Study Group began a commitment to long-term community action that illustrates the principles of transformative research: awareness, active involvement, and social reconstruction. (SK)

Conti, Gary J.; And Others

1991-01-01

429

Reservoir characterization using wavelet transforms  

E-print Network

Automated detection of geological boundaries and determination of cyclic events controlling deposition can facilitate stratigraphic analysis and reservoir characterization. This study applies the wavelet transformation, a recent advance in signal...

Rivera Vega, Nestor

2004-09-30

430

Plant improvement Investigations on transforming  

E-print Network

markers were tested. Functionality of GUS expression vector was checked by particle gun experi- ments because the regeneration step is limiting when in vitro methods are used in transformation experi- ments

Paris-Sud XI, Université de

431

Distributional Chebli-Trimeche transforms  

NASA Astrophysics Data System (ADS)

In this paper we investigate the distributional Chebli-Trimeche transforms. We use the so-called kernel method and we are inspired by the papers of Dube and Pandey [L.S. Dube, J.N. Pandey, On the Hankel transform of distributions, Tohoku Math. J. 27 (1975) 337-354] and Koh and Zemanian [E.L. Koh, A.H. Zemanian, The complex Hankel and I-transformations of generalized functions, SIAM J. Appl. Math. 16 (1968) 945-957] about distributional Hankel transforms. We note that our procedure, supported in a representation of the elements in the corresponding dual spaces, is simpler than the methods described in the above mentioned papers. Some applications of our distributional theory are presented.

Betancor, J. J.; Betancor, J. D.; Mendez, J. M. R.

2006-01-01

432

Phase transformations in engineering materials  

SciTech Connect

Phase transformations in engineering materials are inevitably related to mechanical behavior and are often precursors to residual stress and distortion. Neutron scattering in general is a valuable tool for studying their effects, and pulsed neutrons are of special value, because of the inherently comprehensive crystallographic coverage they provide in each measurement. At the Manuel Lujan neutron scattering center several different research programs have addressed the relationships between phase transformation/mechanical behavior and residual strains. Three disparate examples are presented; (1) stress induced transformation in a NiTi shape memory alloy, (2) cryogenically induced transformation in a quenched 5180 steel, and (3) time resolved evolution of strain induced martensite in 304 stainless steel. In each case a brief description of the principle result will be discussed in the context of using neutrons for the measurement.

Bourke, M.A.M.; Lawson, A.C. [Los Alamos National Lab., NM (United States); Dunand, D.C. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering; Priesmeyer, H.G. [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

1996-06-01

433

The determination of peroxide value by fourier transform infrared spectroscopy  

Microsoft Academic Search

A rapid method for the quantitative determination of peroxide value (PV) of vegetable oils by Fourier transform infrared (FTIR)\\u000a transmission spectroscopy is described. Calibration standards were prepared by the addition oft-butyl hydroperoxide to a series of vegetable oils, along with random amounts of oleic acid and water. Additional standards\\u000a were derived through the addition of mono- and diglyceride spectral contributions,

F. R. van de Voort; A. A. Ismail; J. Sedman; J. Dubois; T. Nicodemo

1994-01-01

434

Shoot regeneration and Agrobacterium -mediated transformation of Fragaria vesca L  

Microsoft Academic Search

An efficient and reliable method for shoot regeneration from leaf disks of Fragaria vesca L. has been developed. This protocol has been successfully employed to obtain transformed plants using Agrobacterium tumefaciens as gene vector. Murashige and Skoog basal medium supplemented with benzyladenine (4 mg\\/l) and indole-3-butyric acid (0.25 mg\\/l) induced the maximum percentage of shoot regeneration (98%) and the highest

Iman Mansouri; José A. Mercado; Victoriano Valpuesta; José M. López-Aranda; Fernando Pliego-Alfaro; Miguel A. Quesada

1996-01-01

435

Rotary Transformer Seals Power In  

NASA Technical Reports Server (NTRS)

Rotary transformer originally developed for spacecraft transfers electrical power from stationary primary winding to rotating secondary without sliding contacts and very little leakage of electromagnetic radiation. Transformer has two stationary primary windings connected in parallel. Secondary, mounted on a shaft that extends out of housing, rotates between two windings of primary. Shaft of secondary is composed of electrically conducting inner and outer parts separated by an insulator. Electrical contact is made from secondary winding, through shaft, to external leads.

Studer, P. A.; Paulkovich, J.

1982-01-01

436

Inducing Transformational Energy Technological Change  

SciTech Connect

Reducing risks of severe climate change in the latter part of the 20th Century is likely to require not only incremental improvements in known energy technologies, but the discovery of transformational new energy technologies. This paper reviews current knowledge about both demand and supply aspects of the challenge of accelerating transformational change, considering both economic and policy incentives, including targeted government funding of research and development, and several other schools of thought about drivers of scientific discovery and innovation.

Wilbanks, Thomas J [ORNL

2011-01-01

437

Unitary Transformation in Probabilistic Teleportation  

E-print Network

We proposed a general transformation in probabilistic teleportation, which is based on different entanglement matching coefficients $K$ corresponding to different unitary evolution which provides one with more flexible evolution method experimentally. Through analysis based on the Bell basis and generalized Bell basis measurement for two probabilistic teleportation, we suggested a general probability of successful teleportation, which is not only determined by the entanglement degree of transmission channels and measurement methods, but also related to the unitary transformation in the teleportation process.

Xiu-Lao Tian; Wei Zhang; Xiao-Qiang Xi

2012-09-09

438

Volumetric Transformation of Brain Anatomy  

Microsoft Academic Search

This paper presents diffeomorphic transformations of three-dimensional (3-D) anatomical image data of the macaque occipital lobe and whole brain cryosection imagery and of deep brain structures in human brains as imaged via magnetic reso- nance imagery. These transformations are generated in a hierar- chical manner, accommodating both global and local anatomical detail. The initial low-dimensional registration is accomplished by constraining

Gary E. Christensen; Sarang C. Joshi; Michael I. Miller

1997-01-01

439

Macrolevel Traceability Via Media Transformations  

Microsoft Academic Search

This paper proposes an alternative approach to the examination of artifacts whose contents must be traceable to promote software\\u000a quality. The approach places emphasis on media use and media transformations. We suggest that one cannot begin to assign and\\u000a sustain traceability relations at a micro-level between units of content if the sign systems that have been created and transformed\\u000a to

Orlena C. Z. Gotel; Stephen J. Morris

2008-01-01

440

A system for transformational analysis  

Microsoft Academic Search

A system is proposed here for assigning a derived P-marker to a given transformed sentence and obtaining the corresponding base P-marker at the same time. Rules of analytical phrase-structure grammar for such a system have associated with them information pertaining to the transformational histories of their own derivation. When a phrase-structure analysis of the sentence is obtained, the set of

Susumu Kuno

1965-01-01

441

Acid rain report focuses on forests  

NASA Astrophysics Data System (ADS)

Recent research on acid precipitation yields “increasing general concern about possible effects on forests,” according to the second annual report of the National Acid Precipitation Assessment Program (NAPAP). Prepared by the Interagency Task Force on Acid Precipitation, the report outlines the accomplishments of the national program during fiscal 1983, summarizes the current state of scientific knowledge (including a change in the baseline acidity of precipitation), and describes the outlook for current progress by federally funded acid precipitation research. Chris Bernabo is the program's executive director.NAPAP's annual report agrees with the finding of a National Research Council (NRC) committee that a linear relationship exists between sulfur dioxide emissions and wet deposition of sulfate (Eos, July 26, 1983, p. 475). NRC's Committee on Atmospheric Transport and Chemical Transformation in Acid Precipitation, which issued its report last year, was chaired by Jack G. Calvert of the National Center for Atmospheric Research.

442

Martensitic Transformation in Austenitic Stainless Steels.  

E-print Network

?? Martensitic transformation is very important in austenitic stainless steels where the transformation induced plasticity phenomenon provides a combination of good mechanical properties, such as… (more)

Naraghi, Reza

2009-01-01

443

Acid sphingomyelinase.  

PubMed

The enzyme acid sphingomyelinase catalyzes the hydrolysis of sphingomyelin to ceramide. The importance of the enzyme for cell functions was first recognized in Niemann-Pick disease type A and B, the genetic disorders with a massive accumulation of sphingomyelin in many organs. Studies in the last years demonstrated that the enzyme also has an important role in cell signalling. Thus, the acid sphingomyelinase has a central function for the re-organization of molecules within the cell upon stimulation and thereby for the response of cells to stress and the induction of cell death but also proliferation and differentiation. Here, we discuss the current state of the art of the structure, regulation, and function of the acid sphingomyelinase. PMID:23579450

Henry, Brian; Ziobro, Regan; Becker, Katrin Anne; Kolesnick, Richard; Gulbins, Erich

2013-01-01

444

Salicylic acids  

PubMed Central

Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

2012-01-01

445

Acid Stomach  

NSDL National Science Digital Library

This Science NetLinks lesson is intended for a high-school, introductory chemistry class or health class. The lesson begins with an article on the history of the development of aspirin. Students will then complete a lab that compares the reaction of regular aspirin, buffered aspirin, and enteric aspirin in neutral, acidic, and basic solutions. They will then analyze the results of the experiment to gain insight into how this information was used by researchers to solve some of the problems associated with aspirin. To complete the lesson, students must understand acids and bases.

Science Netlinks;

2003-08-07

446

Identification of a novel fatty acid elongase with a wide substrate specificity from arachidonic acid-producing fungus Mortierella alpina 1S-4  

Microsoft Academic Search

The isolation and characterization of a gene (MALCE1) that encodes a fatty acid elongase from arachidonic acid-producing fungus Mortierella alpina 1S-4 are described. MALCE1 was confirmed to encode a fatty acid elongase by its expression in yeast Saccharomyces cerevisiae, resulting in the accumulation of 18-, 19-, and 20-carbon monounsaturated fatty acids and eicosanoic acid. Furthermore, the\\u000a MALCE1 yeast transformant efficiently

Eiji Sakuradani; Masutoshi Nojiri; Haruna Suzuki; Sakayu Shimizu

2009-01-01

447

Radiogenic cell transformation and carcinogenesis  

NASA Technical Reports Server (NTRS)

Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic mechanism(s) of radiogenic transformation of human epithelial cells.

Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

1995-01-01

448

A Brønsted acid catalyzed redox arylation.  

PubMed

A Brønsted acid catalyzed redox arylation of ynamides that employs aryl sulfoxides as the arylating agents is reported. This metal-free transformation proceeds at room temperature and efficiently affords ?-arylated oxazolidinones in a redox-neutral, atom-economic fashion. PMID:24590501

Peng, Bo; Huang, Xueliang; Xie, Lan-Gui; Maulide, Nuno

2014-08-11

449

The development of a heterologous transformation system for the cellulolytic fungus Trichoderma reesei based on a pyrG -negative mutant strain  

Microsoft Academic Search

Six uridine auxotroph mutants of Trichoderma reesei QM 9414 were isolated by resistance to 5-fluoroorotic acid and one strain was identified as OMP-decarboxylase negative (pyr-) by a radiometric enzyme assay. Transformation to uridine prototrophy was achieved with the pyr4 gene of Neurospora crassa (up to 1500 transformants\\/µg) and with pyrA of Aspergillus niger (700–800 transformants\\/µg). In many transformants the PYR+

F. Gruber; J. Visser; C. P. Kubicek; L. H. Graaff

1990-01-01

450

Acid rain  

Microsoft Academic Search

The book describes numerous environmental problems which are the result of emissions from coal combustion, petroleum products combustion, petroleum refining, and non-ferrous smelting. The effects of acid rain on soils, plants, water, aquatic ecosystems, and building materials are described. Studies are discussed which show that wind currents are carrying emissions to locations far from the source, with social, economic, and

Ostmann; R. Jr

1982-01-01

451

Acid rain  

SciTech Connect

An overview is presented of acid rain and the problems it causes to the environment worldwide. The acidification of lakes and streams is having a dramatic effect on aquatic life. Aluminum, present in virtually all forest soils, leaches out readily under acid conditions and interferes with the gills of all fish, some more seriously than others. There is evidence of major damage to forests in European countries. In the US, the most severe forest damage appears to be in New England, New York's Adirondacks, and the central Appalachians. This small region is part of a larger area of the Northeast and Canada that appears to have more acid rainfall than the rest of the country. It is downwind from major coal burning states, which produce about one quarter of US SO/sub 2/ emissions and one sixth of nitrogen oxide emissions. Uncertainties exist over the causes of forest damage and more research is needed before advocating expensive programs to reduce rain acidity. The President's current budget seeks an expansion of research funds from the current $30 million per year to $120 million.

Not Available

1984-06-01

452

Selective Inhibition by Benzaldehyde of the Uptake of Nucleosides and Sugar into Simian Virus 40-transformed Cells  

Microsoft Academic Search

The effects of benzaldehyde, which has been found in figs as a carcinostatic element, were studied on the uptake of nucleosides, 2-deoxy-D-glucose, and amino acids into simian virus 40-transformed rat fibroblast cells (SV40-transformed cells) and into the parent normal cells (normal cells). Benzal dehyde, at the concentrations of 25 to 100 jug\\/ml at which the selective growth inhibition against SV40-transformed

Masaaki Watanuki; Kenji Sakaguchi

453

Pseudocolor transformation of ERTS imagery  

NASA Technical Reports Server (NTRS)

One of the photographic techniques which shows great promise as an aid in interpreting ERTS imagery is pseudocolor transformation. It is a process where each shade of gray in an original black-and-white image is seen as a different color in the transformation. The well known ERTS-1 MSS image of the Monterey Bay-San Francisco area was transformed using a technique which requires only two intermediate separations. Possible faults were delineated on an overlay of the transformation before referring to geologic maps. The results were quite remarkable in that all large active or recently active faults shown on the latest geologic map of California were interpreted from the image for all, or much, of their length. Perhaps the most interesting result was the Reliz fault. The fault is shown as covered; however, a lineation corresponding to the position of the fault is visible on the image. The usefulness of ERTS image in identifying recently active faults is demonstrable. Although the faults are also visible in the unenhanced image, they are clearly accentuated and more easily mapped on the pseudocolor transformation.

Lamar, J. V.; Merifield, P. M.

1973-01-01

454

Transformation of Iopamidol during Chlorination.  

PubMed

The transformation of the iodinated X-ray contrast media (ICM) iopamidol, iopromide, iohexol, iomeprol, and diatrizoate was examined in purified water over the pH range from 6.5 to 8.5 in the presence of sodium hypochlorite, monochloramine, and chlorine dioxide. In the presence of aqueous chlorine, only iopamidol was transformed. All other ICM did not show significant reactivity, regardless of the oxidant used. Chlorination of iopamidol followed a second order reaction, with an observed rate constant of up to 0.87 M(-1) s(-1) (±0.021 M(-1) s(-1)) at pH 8.5. The hypochlorite anion was identified to be the reactive chlorine species. Iodine was released during the transformation of iopamidol, and was mainly oxidized to iodate. Only a small percentage (less than 2% after 24 h) was transformed to known organic iodinated disinfection byproducts (DBPs) of low molecular weight. Some of the iodine was still present in high-molecular weight DBPs. The chemical structures of these DBPs were elucidated via MS(n) fragmentation and NMR. Side chain cleavage was observed as well as the exchange of iodine by chlorine. An overall transformation pathway was proposed for the degradation of iopamidol. CHO cell chronic cytotoxicity tests indicate that chlorination of iopamidol generates a toxic mixture of high molecular weight DBPs (LC50 332 ng/?L). PMID:25325766

Wendel, Friedrich M; Lütke Eversloh, Christian; Machek, Edward J; Duirk, Stephen E; Plewa, Michael J; Richardson, Susan D; Ternes, Thomas A

2014-11-01

455

Choline Supplementation Inhibits Diethanolamine-Induced Morphological Transformation in Syrian Hamster Embryo Cells: Evidence for a Carcinogenic Mechanism  

Microsoft Academic Search

DEA, an amino alcohol, and its fatty acid condensates are widely used in commerce. DEA is hepatocarcinogenic in mice, but shows no evidence of mutagenicity or clastogenicity in a standard testing battery. However, it increased the number of morphologi- cally transformed colonies in the Syrian hamster embryo (SHE) cell morphologic transformation assay. The goal of this work was to test

L. D. Lehman-McKeeman

2000-01-01

456

Heat storage in alloy transformations  

NASA Astrophysics Data System (ADS)

The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase change media.

Birchenall, C. E.; Gueceri, S. I.; Farkas, D.; Labdon, M. B.; Nagaswami, N.; Pregger, B.

1981-03-01

457

Enhanced perturbative continuous unitary transformations  

NASA Astrophysics Data System (ADS)

Unitary transformations are an essential tool for the theoretical understanding of many systems by mapping them to simpler effective models. A systematically controlled variant to perform such a mapping is a perturbative continuous unitary transformation (pCUT) among others. So far, this approach required an equidistant unperturbed spectrum. Here, we pursue two goals: First, we extend its applicability to nonequidistant spectra with the particular focus on an efficient derivation of the differential flow equations, which define the enhanced perturbative continuous unitary transformation (epCUT). Second, we show that the numerical integration of the flow equations yields a robust scheme to extract data from the epCUT. The method is illustrated by the perturbation of the harmonic oscillator with a quartic term and of the two-leg spin ladders in the strong-rung-coupling limit for uniform and alternating rung couplings. The latter case provides an example of perturbation around a nonequidistant spectrum.

Krull, H.; Drescher, N. A.; Uhrig, G. S.

2012-09-01

458

Heat storage in alloy transformations  

NASA Technical Reports Server (NTRS)

The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase change media.

Birchenall, C. E.; Gueceri, S. I.; Farkas, D.; Labdon, M. B.; Nagaswami, N.; Pregger, B.

1981-01-01

459

Trace Driven Data Structure Transformations  

SciTech Connect

As the complexity of scientific codes and computational hardware increases it is increasingly important to study the effects of data-structure layouts on program memory behavior. Program structure layouts affect the memory performance differently, therefore we need the capability to effectively study such transformations without the need to rewrite application codes. Trace-driven simulations are an effective and convenient mechanism to simulate program behavior at various granularities. During an application s execution, a tool known as a tracer or profiler, collects program flow data and records program instructions. The trace-file consists of tuples that associate each program instruction with program internal variables. In this paper we outline a proof-of-concept mechanism to apply data-structure transformations during trace simulation and observe effects on memory without the need to manually transform an application s code.

Janjusic, Tomislav [University of North Texas; Kartsaklis, Christos [ORNL

2012-01-01

460

Industrial Signal Filter Base on Wavelet Transform  

Microsoft Academic Search

Since some industrial signals have very low sampling rate, it is impossible to remove the noise from this kind of signal via traditional filter method. This work carefully introduced the wavelet transform de-noise method, including the practical filter bank way to perform the wavelet transform and inverse wavelet transform. The programming work flows of doing signal filtering via wavelet transform

Yuwei Yu; Qingyin Jiang; Zhikai Cao

2009-01-01