Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non-Heme Iron(III) Complexes

Science.gov (United States)

Jastrzebski, Robin; Quesne, Matthew G; Weckhuysen, Bert M; de Visser, Sam P; Bruijnincx, Pieter C A

2014-01-01

Catechol intradiol dioxygenation is a unique reaction catalyzed by iron-dependent enzymes and non-heme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational modelling of multiple iron(III) catecholato complexes, we have elucidated the catechol cleavage mechanism and show that oxygen binds the iron center by partial dissociation of the substrate from the iron complex. The iron(III) superoxide complex that is formed subsequently attacks the carbon atom of the substrate by a rate-determining C=O bond formation step. PMID:25322920

Structural and Functional Models of Non-Heme Iron Enzymes : A Study of the 2-His-1-Carboxylate Facial Triad Structural Motif

NARCIS (Netherlands)

Bruijnincx, P.C.A.

2007-01-01

The structural and functional modeling of a specific group of non-heme iron enzymes by the synthesis of small synthetic analogues is the topic of this thesis. The group of non-heme iron enzymes with the 2-His-1-carboxylate facial triad has recently been established as a common platform for the

A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol

NARCIS (Netherlands)

Chen, Juan; Stepanovic, Stepan; Draksharapu, Apparao; Gruden, Maja; Browne, Wesley R

2018-01-01

Non-heme (L)FeIIIand (L)FeIII-O-FeIII(L) complexes (L=1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)ethan-1-amine) underwent reduction under irradiation to the FeIIstate with concomitant oxidation of methanol to methanal, without the need for a secondary photosensitizer. Spectroscopic and DFT

Near-IR MCD of the nonheme ferrous active site in naphthalene 1,2-dioxygenase: correlation to crystallography and structural insight into the mechanism of Rieske dioxygenases.

Science.gov (United States)

Ohta, Takehiro; Chakrabarty, Sarmistha; Lipscomb, John D; Solomon, Edward I

2008-02-06

Near-IR MCD and variable temperature, variable field (VTVH) MCD have been applied to naphthalene 1,2-dioxygenase (NDO) to describe the coordination geometry and electronic structure of the mononuclear nonheme ferrous catalytic site in the resting and substrate-bound forms with the Rieske 2Fe2S cluster oxidized and reduced. The structural results are correlated with the crystallographic studies of NDO and other related Rieske nonheme iron oxygenases to develop molecular level insights into the structure/function correlation for this class of enzymes. The MCD data for resting NDO with the Rieske center oxidized indicate the presence of a six-coordinate high-spin ferrous site with a weak axial ligand which becomes more tightly coordinated when the Rieske center is reduced. Binding of naphthalene to resting NDO (Rieske oxidized and reduced) converts the six-coordinate sites into five-coordinate (5c) sites with elimination of a water ligand. In the Rieske oxidized form the 5c sites are square pyramidal but transform to a 1:2 mixture of trigonal bipyramial/square pyramidal sites when the Rieske center is reduced. Thus the geometric and electronic structure of the catalytic site in the presence of substrate can be significantly affected by the redox state of the Rieske center. The catalytic ferrous site is primed for the O2 reaction when substrate is bound in the active site in the presence of the reduced Rieske site. These structural changes ensure that two electrons and the substrate are present before the binding and activation of O2, which avoids the uncontrolled formation and release of reactive oxygen species.

Peroxide Activation for Electrophilic Reactivity by the Binuclear Non-heme Iron Enzyme AurF

International Nuclear Information System (INIS)

Park, Kiyoung; Li, Ning; Kwak, Yeonju; Srnec, Martin

2017-01-01

Binuclear non-heme iron enzymes activate O 2 for diverse chemistries that include oxygenation of organic substrates and hydrogen atom abstraction. This process often involves the formation of peroxo-bridged biferric intermediates, only some of which can perform electrophilic reactions. To elucidate the geometric and electronic structural requirements to activate peroxo reactivity, the active peroxo intermediate in 4-aminobenzoate N-oxygenase (AurF) has been characterized spectroscopically and computationally. A magnetic circular dichroism study of reduced AurF shows that its electronic and geometric structures are poised to react rapidly with O 2 . Nuclear resonance vibrational spectroscopic definition of the peroxo intermediate formed in this reaction shows that the active intermediate has a protonated peroxo bridge. Density functional theory computations on the structure established here show that the protonation activates peroxide for electrophilic/single-electron-transfer reactivity. As a result, this activation of peroxide by protonation is likely also relevant to the reactive peroxo intermediates in other binuclear non-heme iron enzymes.

Mono- and binuclear non-heme iron chemistry from a theoretical perspective

Czech Academy of Sciences Publication Activity Database

Rokob, T. A.; Chalupský, Jakub; Bím, Daniel; Andrikopoulos, Prokopis C.; Srnec, Martin; Rulíšek, Lubomír

2016-01-01

Roč. 21, 5/6 (2016), s. 619-644 ISSN 0949-8257 R&D Projects: GA ČR(CZ) GJ15-10279Y; GA ČR(CZ) GA14-31419S; GA ČR GA15-19143S Grant - others:COST(XE) CM1305 Institutional support: RVO:61388963 ; RVO:61388955 Keywords : non-heme iron * density functional theory * multireference methods * dioxygen activation * reactivity Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.894, year: 2016

Effects of illumination and packaging on non-heme iron and color attributes of sliced ham.

Science.gov (United States)

Li, H; Li, C B; Xu, X L; Zhou, G H

2012-08-01

This study was designed to investigate effects of illumination and packaging on color of cooked cured sliced ham during refrigeration, and the possibility of decomposition of nitrosylheme under light and oxygen exposure. Three illumination levels and three packaging films with different oxygen transmission rates (OTRs) were used in two separate experiments during 35 days storage, and pH value, a* value, nitrosylheme, residual nitrite and non-heme iron were evaluated. Packaging OTRs had significant effects (P0.05) nitrosylheme concentration during storage. For both groups, storage time had a significant effect (P<0.01) on a* value and nitrosylheme. Negative relationships between nitrosylheme and nitrite in the illumination group, and between nitrosylheme and non-heme iron in the packaging group were observed. Therefore, illumination level and packaging OTR had limited effects on overall pigment stability, but more discoloration and loss of redness occurred on the surface of products. Copyright © 2012 Elsevier Ltd. All rights reserved.

Moessbauer spectroscopy on the reaction center of Rhodopseudomonas viridis

International Nuclear Information System (INIS)

Frolov, E.; Goldanskii, V.I.; Birk, A.; Parak, F.; Fritzsch, G.; Sinning, I.; Michel, H.

1992-01-01

Proteins called 'reaction centers' (RC) can be isolated from many photosynthetic bacteria. They have one non-heme iron in a quinone acceptor region. The RC of Rhodopseudomonas viridis contains an additional tightly bound tetra-heme cytochrome c subunit. The electronic configuration of both cytochrome and the non-heme iron has been studied in the crystallized protein by Moessbauer spectroscopy at different redox potentials, pH-values, and with an addition of o-phenanthroline. At high potentials (E h =+500 mV) all heme irons are in the low spin Fe 3+ -state, and at low potential (E h = 1 50 mV) they are low spin Fe 2+ with the same Moessbauer parameters for all hemes independent of pH. Redox titrations change the relative area of the reduced and oxidized states in agreement with other methods. The non-heme iron shows a high spin Fe 2+ configuration independent of E h and pH with parameters comparable to those of Rhodopseudomonas sphaeroides. Surprisingly, there is strong evidence for another non-heme iron species in part of the molecules with a Fe 2+ low spin configuration. Incubation with o-phenanthroline decreases the relative Fe 2+ hs-area and increases the contribution of Fe 2+ ls-area. Above 210 K the mean square displacement, 2 >, of the RC-crystals increases more than linearly with temperature. This may be correlated with the increase of the electron transfer rate and indicates that intramolecular mobility influences the functional activity of a protein. (orig.)

A Mononuclear Non-Heme Manganese(IV)-Oxo Complex Binding Redox-Inactive Metal Ions

Energy Technology Data Exchange (ETDEWEB)

Chen, Junying; Lee, Yong-Min; Davis, Katherine M.; Wu, Xiujuan; Seo, Mi Sook; Cho, Kyung-Bin; Yoon, Heejung; Park, Young Jun; Fukuzumi, Shunichi; Pushkar, Yulia N.; Nam, Wonwoo [Ewha; (Purdue); (Osaka)

2013-05-29

Redox-inactive metal ions play pivotal roles in regulating the reactivities of high-valent metal–oxo species in a variety of enzymatic and chemical reactions. A mononuclear non-heme Mn(IV)–oxo complex bearing a pentadentate N₅ ligand has been synthesized and used in the synthesis of a Mn(IV)–oxo complex binding scandium ions. The Mn(IV)–oxo complexes were characterized with various spectroscopic methods. The reactivities of the Mn(IV)–oxo complex are markedly influenced by binding of Sc³⁺ ions in oxidation reactions, such as a ~2200-fold increase in the rate of oxidation of thioanisole (i.e., oxygen atom transfer) but a ~180-fold decrease in the rate of C–H bond activation of 1,4-cyclohexadiene (i.e., hydrogen atom transfer). The present results provide the first example of a non-heme Mn(IV)–oxo complex binding redox-inactive metal ions that shows a contrasting effect of the redox-inactive metal ions on the reactivities of metal–oxo species in the oxygen atom transfer and hydrogen atom transfer reactions.

Multiple Bistability in Quinonoid-Bridged Diiron(II) Complexes: Influence of Bridge Symmetry on Bistable Properties.

Science.gov (United States)

van der Meer, Margarethe; Rechkemmer, Yvonne; Breitgoff, Frauke D; Marx, Raphael; Neugebauer, Petr; Frank, Uta; van Slageren, Joris; Sarkar, Biprajit

2016-11-21

Quinonoid bridges are well-suited for generating dinuclear assemblies that might display various bistable properties. In this contribution we present two diiron(II) complexes where the iron(II) centers are either bridged by the doubly deprotonated form of a symmetrically substituted quinonoid bridge, 2,5-bis[4-(isopropyl)anilino]-1,4-benzoquinone (H 2 L2') with a [O,N,O,N] donor set, or with the doubly deprotonated form of an unsymmetrically substituted quinonoid bridge, 2-[4-(isopropyl)anilino]-5-hydroxy-1,4-benzoquinone (H 2 L5') with a [O,O,O,N] donor set. Both complexes display temperature-induced spin crossover (SCO). The nature of the SCO is strongly dependent on the bridging ligand, with only the complex with the [O,O,O,N] donor set displaying a prominent hysteresis loop of about 55 K. Importantly, only the latter complex also shows a pronounced light-induced spin state change. Furthermore, both complexes can be oxidized to the mixed-valent iron(II)-iron(III) form, and the nature of the bridge determines the Robin and Day classification of these forms. Both complexes have been probed by a battery of electrochemical, spectroscopic, and magnetic methods, and this combined approach is used to shed light on the electronic structures of the complexes and on bistability. The results presented here thus show the potential of using the relatively new class of unsymmetrically substituted bridging quinonoid ligands for generating intriguing bistable properties and for performing site-specific magnetic switching.

Electron Transport in a Dioxygenase-Ferredoxin Complex: Long Range Charge Coupling between the Rieske and Non-Heme Iron Center.

Directory of Open Access Journals (Sweden)

Wayne K Dawson

Full Text Available Dioxygenase (dOx utilizes stereospecific oxidation on aromatic molecules; consequently, dOx has potential applications in bioremediation and stereospecific oxidation synthesis. The reactive components of dOx comprise a Rieske structure Cys2[2Fe-2S]His2 and a non-heme reactive oxygen center (ROC. Between the Rieske structure and the ROC, a universally conserved Asp residue appears to bridge the two structures forming a Rieske-Asp-ROC triad, where the Asp is known to be essential for electron transfer processes. The Rieske and ROC share hydrogen bonds with Asp through their His ligands; suggesting an ideal network for electron transfer via the carboxyl side chain of Asp. Associated with the dOx is an itinerant charge carrying protein Ferredoxin (Fdx. Depending on the specific cognate, Fdx may also possess either the Rieske structure or a related structure known as 4-Cys-[2Fe-2S] (4-Cys. In this study, we extensively explore, at different levels of theory, the behavior of the individual components (Rieske and ROC and their interaction together via the Asp using a variety of density function methods, basis sets, and a method known as Generalized Ionic Fragment Approach (GIFA that permits setting up spin configurations manually. We also report results on the 4-Cys structure for comparison. The individual optimized structures are compared with observed spectroscopic data from the Rieske, 4-Cys and ROC structures (where information is available. The separate pieces are then combined together into a large Rieske-Asp-ROC (donor/bridge/acceptor complex to estimate the overall coupling between individual components, based on changes to the partial charges. The results suggest that the partial charges are significantly altered when Asp bridges the Rieske and the ROC; hence, long range coupling through hydrogen bonding effects via the intercalated Asp bridge can drastically affect the partial charge distributions compared to the individual isolated

Rieske non-heme iron-dependent oxygenases catalyse diverse reactions in natural product biosynthesis.

Science.gov (United States)

Perry, Christopher; de Los Santos, Emmanuel L C; Alkhalaf, Lona M; Challis, Gregory L

2018-04-13

Covering: up to the end of 2017The roles played by Rieske non-heme iron-dependent oxygenases in natural product biosynthesis are reviewed, with particular focus on experimentally characterised examples. Enzymes belonging to this class are known to catalyse a range of transformations, including oxidative carbocyclisation, N-oxygenation, C-hydroxylation and C-C desaturation. Examples of such enzymes that have yet to be experimentally investigated are also briefly described and their likely functions are discussed.

Determination of Spin Inversion Probability, H-Tunneling Correction, and Regioselectivity in the Two-State Reactivity of Nonheme Iron(IV)-Oxo Complexes.

Science.gov (United States)

Kwon, Yoon Hye; Mai, Binh Khanh; Lee, Yong-Min; Dhuri, Sunder N; Mandal, Debasish; Cho, Kyung-Bin; Kim, Yongho; Shaik, Sason; Nam, Wonwoo

2015-04-16

We show by experiments that nonheme Fe(IV)O species react with cyclohexene to yield selective hydrogen atom transfer (HAT) reactions with virtually no C═C epoxidation. Straightforward DFT calculations reveal, however, that C═C epoxidation on the S = 2 state possesses a low-energy barrier and should contribute substantially to the oxidation of cyclohexene by the nonheme Fe(IV)O species. By modeling the selectivity of this two-site reactivity, we show that an interplay of tunneling and spin inversion probability (SIP) reverses the apparent barriers and prefers exclusive S = 1 HAT over mixed HAT and C═C epoxidation on S = 2. The model enables us to derive a SIP value by combining experimental and theoretical results.

A functional mimic of natural peroxidases : synthesis and catalytic activity of a non-heme iron peptide hydroperoxide complex

NARCIS (Netherlands)

Choma, CT; Schudde, EP; Kellogg, RM; Robillard, GT; Feringa, BL

1998-01-01

Site-selective attachment of unprotected peptides to a non-heme iron complex is achieved by displacing two halides on the catalyst by peptide caesium thiolates, This coupling approach should be compatible with any peptide sequence provided there is only a single reduced cysteine. The oxidation

Ammonia formation by a thiolate-bridged diiron amide complex as a nitrogenase mimic

Science.gov (United States)

Li, Yang; Li, Ying; Wang, Baomin; Luo, Yi; Yang, Dawei; Tong, Peng; Zhao, Jinfeng; Luo, Lun; Zhou, Yuhan; Chen, Si; Cheng, Fang; Qu, Jingping

2013-04-01

Although nitrogenase enzymes routinely convert molecular nitrogen into ammonia under ambient temperature and pressure, this reaction is currently carried out industrially using the Haber-Bosch process, which requires extreme temperatures and pressures to activate dinitrogen. Biological fixation occurs through dinitrogen and reduced NxHy species at multi-iron centres of compounds bearing sulfur ligands, but it is difficult to elucidate the mechanistic details and to obtain stable model intermediate complexes for further investigation. Metal-based synthetic models have been applied to reveal partial details, although most models involve a mononuclear system. Here, we report a diiron complex bridged by a bidentate thiolate ligand that can accommodate HN=NH. Following reductions and protonations, HN=NH is converted to NH3 through pivotal intermediate complexes bridged by N2H3- and NH2- species. Notably, the final ammonia release was effected with water as the proton source. Density functional theory calculations were carried out, and a pathway of biological nitrogen fixation is proposed.

An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion.

Science.gov (United States)

Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D; Nam, Wonwoo

2014-02-18

Reaction of a nonheme iron(III)-peroxo complex, [Fe(III)(14-TMC)(O2)](+), with NO(+), a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2˙(-)) + NO], affords an iron(IV)-oxo complex, [Fe(IV)(14-TMC)(O)](2+), and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [Fe(III)(14-TMC)(NO3)(F)](+).

Kinetic and CD/MCD spectroscopic studies of the atypical, three-His-ligated, non-heme Fe2+ center in diketone dioxygenase: the role of hydrophilic outer shell residues in catalysis.

Science.gov (United States)

Straganz, Grit D; Diebold, Adrienne R; Egger, Sigrid; Nidetzky, Bernd; Solomon, Edward I

2010-02-09

Diketone cleaving enzyme (Dke1) is a dioxygenase with an atypical, three-histidine-ligated, mononuclear non-heme Fe(2+) center. To assess the role in enzyme catalysis of the hydrophilic residues in the active site pocket, residues Glu98, Arg80, Tyr70, and Thr107 were subjected to mutational analysis. Steady state and pre-steady state kinetics indicated a role for Glu98 in promoting both substrate binding and O(2) reduction. Additionally, the Glu98 substitution eliminated the pH dependence of substrate binding (k(cat)(app)/K(M)(app)-pH profile) present in wild-type Dke1 (pK(a) = 6.3 +/- 0.4 and 8.4 +/- 0.4). MCD spectroscopy revealed that the Glu98 --> Gln mutation leads to the conversion of the six-coordinate (6C) resting Fe(2+) center present in the wild-type enzyme at pH 7.0 to a mixture of five-coordinate (5C) and 6C sites. The 6C geometry was restored with a pH shift to 9.5 which also resulted in ligand field (LF) energy splittings identical to that found for wild-type (WT) Dke1 at pH 9.5. In WT Dke1, these LF transitions are shifted up in energy by approximately 300 cm(-1) at pH 9.5 relative to pH 7.0. These data, combined with CD pH titrations which reveal a pK(a) of approximately 8.2 for resting WT Dke1 and the Glu98 --> Gln variant, indicate the deprotonation of a metal-ligated water. Together, the kinetic and spectroscopic data reveal a stabilizing effect of Glu98 on the 6C geometry of the metal center, priming it for substrate ligation. Arg80 and Tyr70 are shown to promote O(2) reduction, while Thr107 stabilizes the Fe(II) cofactor.

Synthesis of a Non-Heme Template for Attaching Four Peptides : An Approach to Artificial Iron(II)-Containing Peroxidases

NARCIS (Netherlands)

Heuvel, Marco van den; Berg, Tieme A. van den; Kellogg, Richard M.; Choma, Christin T.; Feringa, Bernard

2004-01-01

We are developing all-synthetic model cofactor-protein complexes in order to define the parameters controlling non-natural cofactor activity. The long-term objective is to establish the theoretical and practical basis for designing novel enzymes. A non-heme pentadentate ligand (N4Py) is being

An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion†

Science.gov (United States)

Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D.; Nam, Wonwoo

2014-01-01

Reaction of a nonheme iron(III)-peroxo complex, [FeIII(14-TMC)(O2)]+, with NO+, a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2•−) + NO], affords an iron(IV)-oxo complex, [FeIV(14-TMC)(O)]2+, and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [FeIII(14-TMC)(NO3)(F)]+. PMID:24394960

An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion†

OpenAIRE

Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D.; Nam, Wonwoo

2014-01-01

Reaction of a nonheme iron(III)-peroxo complex, [FeIII(14-TMC)(O2)]+, with NO+, a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2•−) + NO], affords an iron(IV)-oxo complex, [FeIV(14-TMC)(O)]2+, and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [FeIII(14-TMC)(NO3)(F)]+.

Increasing the cooking temperature of meat does not affect nonheme iron absorption from a phytate-rich meal in women

DEFF Research Database (Denmark)

Baech, S.B.; Hansen, M.; Bukhave, Klaus

2003-01-01

The effect of increasing cooking temperatures of meat on nonheme iron absorption from a composite meal was investigated. Cysteine-containing peptides may have a role in the iron absorption enhancing effect of muscle proteins. Heat treatment can change the content of sulfhydryl groups produced from...... cysteine and thereby affect iron absorption. Twenty-one women (25 +/- 3 y) were served a basic meal without meat and two other meals consisting of the basic meal plus 75 g of pork meat cooked at 70, 95 or 120degreesC. The meals were extrinsically labeled with Fe-55 or Fe-59. Iron absorption was determined...... from measurements of wholebody Fe-59 retention and the activity of Fe-55 and Fe-59 in blood samples. Nonheme iron absorptions were 0.9 (0.5-4.0)% (P = 0.06), 0.7 (0.4-3.9)% (P = 0.1) and 2.0 (1.3-3.1)% (P cooked at 70, 95 or 120degreesC, respectively, was added to the basic...

Nonheme oxoiron(IV) complexes of pentadentate N5 ligands: spectroscopy, electrochemistry, and oxidative reactivity

OpenAIRE

Wang, Dong; Ray, Kallol; Collins, Michael J.; Farquhar, Erik R.; Frisch, Jonathan R.; Gomez, Laura; Jackson, Timothy A.; Kerscher, Marion; Waleska, Arkadius; Comba, Peter; Costas, Miquel; Que, Lawrence, Jr.

2013-01-01

Oxoiron(IV) species have been found to act as the oxidants in the catalytic cycles of several mononuclear nonheme iron enzymes that activate dioxygen. To gain insight into the factors that govern the oxidative reactivity of such complexes, a series of five synthetic S = 1 [FeIV(O)(LN5)]2+ complexes has been characterized with respect to their spectroscopic and electrochemical properties as well as their relative abilities to carry out oxo transfer and hydrogen atom abstraction. The Fe=O units...

Structures of the multicomponent Rieske non-heme iron toluene 2, 3-dioxygenase enzyme system

Energy Technology Data Exchange (ETDEWEB)

Friemann, Rosmarie [Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden); Lee, Kyoung [Department of Microbiology, Changwon National University, Changwon, Kyoungnam 641-773 (Korea, Republic of); Department of Microbiology, The University of Iowa, Iowa City, Iowa 52242 (United States); Brown, Eric N. [Department of Biochemistry, The University of Iowa, Iowa City, Iowa 52242 (United States); Gibson, David T. [Department of Microbiology, The University of Iowa, Iowa City, Iowa 52242 (United States); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden); Ramaswamy, S., E-mail: s-ramaswamy@uiowa.edu [Department of Biochemistry, The University of Iowa, Iowa City, Iowa 52242 (United States); Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden)

2009-01-01

The crystal structures of the three-component toluene 2, 3-dioxygenase system provide a model for electron transfer among bacterial Rieske non-heme iron dioxygenases. Bacterial Rieske non-heme iron oxygenases catalyze the initial hydroxylation of aromatic hydrocarbon substrates. The structures of all three components of one such system, the toluene 2, 3-dioxygenase system, have now been determined. This system consists of a reductase, a ferredoxin and a terminal dioxygenase. The dioxygenase, which was cocrystallized with toluene, is a heterohexamer containing a catalytic and a structural subunit. The catalytic subunit contains a Rieske [2Fe–2S] cluster and mononuclear iron at the active site. This iron is not strongly bound and is easily removed during enzyme purification. The structures of the enzyme with and without mononuclear iron demonstrate that part of the structure is flexible in the absence of iron. The orientation of the toluene substrate in the active site is consistent with the regiospecificity of oxygen incorporation seen in the product formed. The ferredoxin is Rieske type and contains a [2Fe–2S] cluster close to the protein surface. The reductase belongs to the glutathione reductase family of flavoenzymes and consists of three domains: an FAD-binding domain, an NADH-binding domain and a C-terminal domain. A model for electron transfer from NADH via FAD in the reductase and the ferredoxin to the terminal active-site mononuclear iron of the dioxygenase is proposed.

Engineering Non-Heme Mono- and Dioxygenases for Biocatalysis

Directory of Open Access Journals (Sweden)

Adi Dror

2012-09-01

Full Text Available Oxygenases are ubiquitous enzymes that catalyze the introduction of one or two oxygen atoms to unreactive chemical compounds. They require reduction equivalents from NADH or NADPH and comprise metal ions, metal ion complexes, or coenzymes in their active site. Thus, for industrial purposes, oxygenases are most commonly employed using whole cell catalysis, to alleviate the need for co-factor regeneration. Biotechnological applications include bioremediation, chiral synthesis, biosensors, fine chemicals, biofuels, pharmaceuticals, food ingredients and polymers. Controlling activity and selectivity of oxygenases is therefore of great importance and of growing interest to the scientific community. This review focuses on protein engineering of non-heme monooxygenases and dioxygenases for generating improved or novel functionalities. Rational mutagenesis based on x-ray structures and sequence alignment, as well as random methods such as directed evolution, have been utilized. It is concluded that knowledge-based protein engineering accompanied with targeted libraries, is most efficient for the design and tuning of biocatalysts towards novel substrates and enhanced catalytic activity while minimizing the screening efforts.

Nonheme-iron absorption from a phytate-rich meal is increased by the addition of small amounts of pork meat

DEFF Research Database (Denmark)

Boech, S.B.; Hansen, M.; Bukhave, Klaus

2003-01-01

of small amounts of meat on nonheme-iron absorption from a meal presumed to have low iron bioavailability. Design: Forty-five healthy women with a mean (+/-SD) age of 24 +/- 3 y were randomly assigned to I of 3 groups, each of which was served (A) a basic meal (rice, tomato sauce, pea puree, and a wheat...

Arene activation by a nonheme iron(III)-hydroperoxo complex: pathways leading to phenol and ketone products.

Science.gov (United States)

Faponle, Abayomi S; Banse, Frédéric; de Visser, Sam P

2016-07-01

Iron(III)-hydroperoxo complexes are found in various nonheme iron enzymes as catalytic cycle intermediates; however, little is known on their catalytic properties. The recent work of Banse and co-workers on a biomimetic nonheme iron(III)-hydroperoxo complex provided evidence of its involvement in reactivity with arenes. This contrasts the behavior of heme iron(III)-hydroperoxo complexes that are known to be sluggish oxidants. To gain insight into the reaction mechanism of the biomimetic iron(III)-hydroperoxo complex with arenes, we performed a computational (density functional theory) study. The calculations show that iron(III)-hydroperoxo reacts with substrates via low free energies of activation that should be accessible at room temperature. Moreover, a dominant ketone reaction product is observed as primary products rather than the thermodynamically more stable phenols. These product distributions are analyzed and the calculations show that charge interaction between the iron(III)-hydroxo group and the substrate in the intermediate state pushes the transferring proton to the meta-carbon atom of the substrate and guides the selectivity of ketone formation. These studies show that the relative ratio of ketone versus phenol as primary products can be affected by external interactions of the oxidant with the substrate. Moreover, iron(III)-hydroperoxo complexes are shown to selectively give ketone products, whereas iron(IV)-oxo complexes will react with arenes to form phenols instead.

Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates**

Science.gov (United States)

Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G; Padamati, Sandeep K; Gómez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R; de Visser, Sam P

2015-01-01

FeIII–hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII–hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases. PMID:25663379

The FTO (fat mass and obesity associated gene codes for a novel member of the non-heme dioxygenase superfamily

Directory of Open Access Journals (Sweden)

Andrade-Navarro Miguel A

2007-11-01

Full Text Available Abstract Background Genetic variants in the FTO (fat mass and obesity associated gene have been associated with an increased risk of obesity. However, the function of its protein product has not been experimentally studied and previously reported sequence similarity analyses suggested the absence of homologs in existing protein databases. Here, we present the first detailed computational analysis of the sequence and predicted structure of the protein encoded by FTO. Results We performed a sequence similarity search using the human FTO protein as query and then generated a profile using the multiple sequence alignment of the homologous sequences. Profile-to-sequence and profile-to-profile based comparisons identified remote homologs of the non-heme dioxygenase family. Conclusion Our analysis suggests that human FTO is a member of the non-heme dioxygenase (Fe(II- and 2-oxoglutarate-dependent dioxygenases superfamily. Amino acid conservation patterns support this hypothesis and indicate that both 2-oxoglutarate and iron should be important for FTO function. This computational prediction of the function of FTO should suggest further steps for its experimental characterization and help to formulate hypothesis about the mechanisms by which it relates to obesity in humans.

The Stable Diiron (2.5) Complex Ion [(NC).sub.5./sub.Fe(ć-tz)Fe(CN).sub.5./sub.].sup.5-./sup., tz=1,2,4,5-Tetrazine, and Its Neighboring Oxidation States

Czech Academy of Sciences Publication Activity Database

Glöckle, M.; Kaim, W.; Klein, A.; Roduner, E.; Hübner, G.; Záliš, Stanislav; Slageren van, J.; Renz, F.; Gütlich, P.

2001-01-01

Roč. 40, č. 10 (2001), s. 2256-2262 ISSN 0020-1669 R&D Projects: GA MŠk OC D14.20; GA MŠk OC D15.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : mixed valent compound * diiron tetrazine complex * spectroelectrochemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.946, year: 2001

VTVH-MCD and DFT studies of thiolate bonding to [FeNO]7/[FeO2]8 complexes of isopenicillin N synthase: substrate determination of oxidase versus oxygenase activity in nonheme Fe enzymes.

Science.gov (United States)

Brown, Christina D; Neidig, Michael L; Neibergall, Matthew B; Lipscomb, John D; Solomon, Edward I

2007-06-13

Isopenicillin N synthase (IPNS) is a unique mononuclear nonheme Fe enzyme that catalyzes the four-electron oxidative double ring closure of its substrate ACV. A combination of spectroscopic techniques including EPR, absorbance, circular dichroism (CD), magnetic CD, and variable-temperature, variable-field MCD (VTVH-MCD) were used to evaluate the geometric and electronic structure of the [FeNO]7 complex of IPNS coordinated with the ACV thiolate ligand. Density Function Theory (DFT) calculations correlated to the spectroscopic data were used to generate an experimentally calibrated bonding description of the Fe-IPNS-ACV-NO complex. New spectroscopic features introduced by the binding of the ACV thiolate at 13 100 and 19 800 cm-1 are assigned as the NO pi*(ip) --> Fe dx2-y2 and S pi--> Fe dx2-y2 charge transfer (CT) transitions, respectively. Configuration interaction mixes S CT character into the NO pi*(ip) --> Fe dx2-y2 CT transition, which is observed experimentally from the VTVH-MCD data from this transition. Calculations on the hypothetical {FeO2}8 complex of Fe-IPNS-ACV reveal that the configuration interaction present in the [FeNO]7 complex results in an unoccupied frontier molecular orbital (FMO) with correct orientation and distal O character for H-atom abstraction from the ACV substrate. The energetics of NO/O2 binding to Fe-IPNS-ACV were evaluated and demonstrate that charge donation from the ACV thiolate ligand renders the formation of the FeIII-superoxide complex energetically favorable, driving the reaction at the Fe center. This single center reaction allows IPNS to avoid the O2 bridged binding generally invoked in other nonheme Fe enzymes that leads to oxygen insertion (i.e., oxygenase function) and determines the oxidase activity of IPNS.

A single mutation in the castor Δ9-18:0-desaturase changes reaction partitioning from desaturation to oxidase chemistry

Science.gov (United States)

Guy, Jodie E.; Abreu, Isabel A.; Moche, Martin; Lindqvist, Ylva; Whittle, Edward; Shanklin, John

2006-01-01

Sequence analysis of the diiron cluster-containing soluble desaturases suggests they are unrelated to other diiron enzymes; however, structural alignment of the core four-helix bundle of desaturases to other diiron enzymes reveals a conserved iron binding motif with similar spacing in all enzymes of this structural class, implying a common evolutionary ancestry. Detailed structural comparison of the castor desaturase with that of a peroxidase, rubrerythrin, shows remarkable conservation of both identity and geometry of residues surrounding the diiron center, with the exception of residue 199. Position 199 is occupied by a threonine in the castor desaturase, but the equivalent position in rubrerythrin contains a glutamic acid. We previously hypothesized that a carboxylate in this location facilitates oxidase chemistry in rubrerythrin by the close apposition of a residue capable of facilitating proton transfer to the activated oxygen (in a hydrophobic cavity adjacent to the diiron center based on the crystal structure of the oxygen-binding mimic azide). Here we report that desaturase mutant T199D binds substrate but its desaturase activity decreases by ≈2 × 103-fold. However, it shows a >31-fold increase in peroxide-dependent oxidase activity with respect to WT desaturase, as monitored by single-turnover stopped-flow spectrometry. A 2.65-Å crystal structure of T199D reveals active-site geometry remarkably similar to that of rubrerythrin, consistent with its enhanced function as an oxidase enzyme. That a single amino acid substitution can switch reactivity from desaturation to oxidation provides experimental support for the hypothesis that the desaturase evolved from an ancestral oxidase enzyme. PMID:17088542

Heme and non-heme iron transporters in non-polarized and polarized cells

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Yasui Yumiko

2010-06-01

Full Text Available Abstract Background Heme and non-heme iron from diet, and recycled iron from hemoglobin are important products of the synthesis of iron-containing molecules. In excess, iron is potentially toxic because it can produce reactive oxygen species through the Fenton reaction. Humans can absorb, transport, store, and recycle iron without an excretory system to remove excess iron. Two candidate heme transporters and two iron transporters have been reported thus far. Heme incorporated into cells is degraded by heme oxygenases (HOs, and the iron product is reutilized by the body. To specify the processes of heme uptake and degradation, and the reutilization of iron, we determined the subcellular localizations of these transporters and HOs. Results In this study, we analyzed the subcellular localizations of 2 isoenzymes of HOs, 4 isoforms of divalent metal transporter 1 (DMT1, and 2 candidate heme transporters--heme carrier protein 1 (HCP1 and heme responsive gene-1 (HRG-1--in non-polarized and polarized cells. In non-polarized cells, HCP1, HRG-1, and DMT1A-I are located in the plasma membrane. In polarized cells, they show distinct localizations: HCP1 and DMT1A-I are located in the apical membrane, whereas HRG-1 is located in the basolateral membrane and lysosome. 16Leu at DMT1A-I N-terminal cytosolic domain was found to be crucial for plasma membrane localization. HOs are located in smooth endoplasmic reticulum and colocalize with NADPH-cytochrome P450 reductase. Conclusions HCP1 and DMT1A-I are localized to the apical membrane, and HRG-1 to the basolateral membrane and lysosome. These findings suggest that HCP1 and DMT1A-I have functions in the uptake of dietary heme and non-heme iron. HRG-1 can transport endocytosed heme from the lysosome into the cytosol. These localization studies support a model in which cytosolic heme can be degraded by HOs, and the resulting iron is exported into tissue fluids via the iron transporter ferroportin 1, which is

X-ray absorption spectroscopy of soybean lipoxygenase-1 : Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site

NARCIS (Netherlands)

Vliegenthart, J.F.G.; Heijdt, L.M. van der; Feiters, M.C.; Navaratnam, S.; Nolting, H.-F.; Hermes, C.; Veldink, G.A.

1992-01-01

X-ray absorption spectra at the Fe K-edge of the non-heme iron site in Fe(II) as well as Fe(III) soybean lipoxygenase-1, in frozen solution or lyophilized, are presented; the latter spectra were obtained by incubation of the Fe(II) enzyme with its product hydroperoxide. An edge shift of about 23 eV

Expression and functional analysis of citrus carotene hydroxylases: unravelling the xanthophyll biosynthesis in citrus fruits.

Science.gov (United States)

Ma, Gang; Zhang, Lancui; Yungyuen, Witchulada; Tsukamoto, Issei; Iijima, Natsumi; Oikawa, Michiru; Yamawaki, Kazuki; Yahata, Masaki; Kato, Masaya

2016-06-29

Xanthophylls are oxygenated carotenoids and fulfill critical roles in plant growth and development. In plants, two different types of carotene hydroxylases, non-heme di-iron and heme-containing cytochrome P450, were reported to be involved in the biosynthesis of xanthophyll. Citrus fruits accumulate a high amount of xanthophylls, especially β,β-xanthophylls. To date, however, the roles of carotene hydroxylases in regulating xanthophyll content and composition have not been elucidated. In the present study, the roles of four carotene hydroxylase genes (CitHYb, CitCYP97A, CitCYP97B, and CitCYP97C) in the biosynthesis of xanthophyll in citrus fruits were investigated. Phylogenetic analysis showed that the four citrus carotene hydroxylases presented in four distinct clusters which have been identified in higher plants. CitHYb was a non-heme di-iron carotene hydroxylase, while CitCYP97A, CitCYP97B, and CitCYP97C were heme-containing cytochrome P450-type carotene hydroxylases. Gene expression results showed that the expression of CitHYb increased in the flavedo and juice sacs during the ripening process, which was well consistent with the accumulation of β,β-xanthophyll in citrus fruits. The expression of CitCYP97A and CitCYP97C increased with a peak in November, which might lead to an increase of lutein in the juice sacs during the ripening process. The expression level of CitCYP97B was much lower than that of CitHYb, CitCYP97A, and CitCYP97C in the juice sacs during the ripening process. Functional analysis showed that the CitHYb was able to catalyze the hydroxylation of the β-rings of β-carotene and α-carotene in Escherichia coli BL21 (DE3) cells. Meanwhile, when CitHYb was co-expressed with CitCYP97C, α-carotene was hydroxylated on the β-ring and ε-ring sequentially to produce lutein. CitHYb was a key gene for β,β-xanthophyll biosynthesis in citrus fruits. CitCYP97C functioned as an ε-ring hydroxylase to produce lutein using zeinoxanthin as a substrate

Alkali Metal Variation and Twisting of the FeNNFe Core in Bridging Diiron Dinitrogen Complexes.

Science.gov (United States)

McWilliams, Sean F; Rodgers, Kenton R; Lukat-Rodgers, Gudrun; Mercado, Brandon Q; Grubel, Katarzyna; Holland, Patrick L

2016-03-21

Alkali metal cations can interact with Fe-N2 complexes, potentially enhancing back-bonding or influencing the geometry of the iron atom. These influences are relevant to large-scale N2 reduction by iron, such as in the FeMoco of nitrogenase and the alkali-promoted Haber-Bosch process. However, to our knowledge there have been no systematic studies of a large range of alkali metals regarding their influence on transition metal-dinitrogen complexes. In this work, we varied the alkali metal in [alkali cation]2[LFeNNFeL] complexes (L = bulky β-diketiminate ligand) through the size range from Na(+) to K(+), Rb(+), and Cs(+). The FeNNFe cores have similar Fe-N and N-N distances and N-N stretching frequencies despite the drastic change in alkali metal cation size. The two diketiminates twist relative to one another, with larger dihedral angles accommodating the larger cations. In order to explain why the twisting has so little influence on the core, we performed density functional theory calculations on a simplified LFeNNFeL model, which show that the two metals surprisingly do not compete for back-bonding to the same π* orbital of N2, even when the ligand planes are parallel. This diiron system can tolerate distortion of the ligand planes through compensating orbital energy changes, and thus, a range of ligand orientations can give very similar energies.

Dinitrosyl non-heme iron complexes at the gamma radiation treatment of animals

International Nuclear Information System (INIS)

Aliev, D.I.; Alieva, I.N.; Abilov, Z.G.; Gurbanov, I.S.

2003-01-01

Full text: At the present time there are a great number investigations dedicated to revealing of mechanism formation of 2,03 complexes at the some pathologies in an organism. These complexes are represented weakly bounded form of non-heme iron, including into beside iron two nitrogen oxide molecules (NO) and two paired RS- groups of proteins or low-molecular compounds. 2,03 complexes are characterized by an axial symmetrical tensory of the g-factor with g=2,037, g=2,012 and g=2,03. In this study the data testifying 2,03 complexes formation into liver of animal treated by the fatal dose of gamma-radiation are reported. The changing of the ESR signal form was observed. It was shown that the form and intensity of the 2,03 signal in healthy and irradiated animals are differ from each other. The analysis of the 2,03 signal parameters is confirm this fact, too. The conclusion was made that 2,03 complexes ESR signal may be considered as an indicator of integrity of intracellular membranes of the gamma-irradiated animals

Mononuclear non-heme iron enzymes with the 2-His-1-carboxylate facial triad: recent developments in enzymology and modeling studies.

Science.gov (United States)

Bruijnincx, Pieter C A; van Koten, Gerard; Klein Gebbink, Robertus J M

2008-12-01

Iron-containing enzymes are one of Nature's main means of effecting key biological transformations. The mononuclear non-heme iron oxygenases and oxidases have received the most attention recently, primarily because of the recent availability of crystal structures of many different enzymes and the stunningly diverse oxidative transformations that these enzymes catalyze. The wealth of available structural data has furthermore established the so-called 2-His-1-carboxylate facial triad as a new common structural motif for the activation of dioxygen. This superfamily of mononuclear iron(ii) enzymes catalyzes a wide range of oxidative transformations, ranging from the cis-dihydroxylation of arenes to the biosynthesis of antibiotics such as isopenicillin and fosfomycin. The remarkable scope of oxidative transformations seems to be even broader than that associated with oxidative heme enzymes. Not only are many of these oxidative transformations of key biological importance, many of these selective oxidations are also unprecedented in synthetic organic chemistry. In this critical review, we wish to provide a concise background on the chemistry of the mononuclear non-heme iron enzymes characterized by the 2-His-1-carboxylate facial triad and to discuss the many recent developments in the field. New examples of enzymes with unique reactivities belonging to the superfamily have been reported. Furthermore, key insights into the intricate mechanistic details and reactive intermediates have been obtained from both enzyme and modeling studies. Sections of this review are devoted to each of these subjects, i.e. the enzymes, biomimetic models, and reactive intermediates (225 references).

Diverse bacteria isolated from microtherm oil-production water.

Science.gov (United States)

Sun, Ji-Quan; Xu, Lian; Zhang, Zhao; Li, Yan; Tang, Yue-Qin; Wu, Xiao-Lei

2014-02-01

In total, 435 pure bacterial strains were isolated from microtherm oil-production water from the Karamay Oilfield, Xinjiang, China, by using four media: oil-production water medium (Cai medium), oil-production water supplemented with mineral salt medium (CW medium), oil-production water supplemented with yeast extract medium (CY medium), and blood agar medium (X medium). The bacterial isolates were affiliated with 61 phylogenetic groups that belong to 32 genera in the phyla Actinobacteria, Firmicutes, and Proteobacteria. Except for the Rhizobium, Dietzia, and Pseudomonas strains that were isolated using all the four media, using different media led to the isolation of bacteria with different functions. Similarly, nonheme diiron alkane monooxygenase genes (alkB/alkM) also clustered according to the isolation medium. Among the bacterial strains, more than 24 % of the isolates could use n-hexadecane as the sole carbon source for growth. For the first time, the alkane-degrading ability and alkB/alkM were detected in Rhizobium, Rhodobacter, Trichococcus, Micrococcus, Enterococcus, and Bavariicoccus strains, and the alkM gene was detected in Firmicutes strains.

Oxygen Atom Exchange between H2O and Non-Heme Oxoiron(IV) Complexes: Ligand Dependence and Mechanism.

Science.gov (United States)

Puri, Mayank; Company, Anna; Sabenya, Gerard; Costas, Miquel; Que, Lawrence

2016-06-20

Detailed studies of oxygen atom exchange (OAE) between H2(18)O and synthetic non-heme oxoiron(IV) complexes supported by tetradentate and pentadentate ligands provide evidence that they proceed by a common mechanism but within two different kinetic regimes, with OAE rates that span 2 orders of magnitude. The first kinetic regime involves initial reversible water association to the Fe(IV) complex, which is evidenced by OAE rates that are linearly dependent on [H2(18)O] and H2O/D2O KIEs of 1.6, while the second kinetic regime involves a subsequent rate determining proton-transfer step between the bound aqua and oxo ligands that is associated with saturation behavior with [H2(18)O] and much larger H2O/D2O KIEs of 5-6. [Fe(IV)(O)(TMC)(MeCN)](2+) (1) and [Fe(IV)(O)(MePy2TACN)](2+) (9) are examples of complexes that exhibit kinetic behavior in the first regime, while [Fe(IV)(O)(N4Py)](2+) (3), [Fe(IV)(O)(BnTPEN)](2+) (4), [Fe(IV)(O)(1Py-BnTPEN)](2+) (5), [Fe(IV)(O)(3Py-BnTPEN)](2+) (6), and [Fe(IV)(O)(Me2Py2TACN)](2+) (8) represent complexes that fall in the second kinetic regime. Interestingly, [Fe(IV)(O)(PyTACN)(MeCN)](2+) (7) exhibits a linear [H2(18)O] dependence below 0.6 M and saturation above 0.6 M. Analysis of the temperature dependence of the OAE rates shows that most of these complexes exhibit large and negative activation entropies, consistent with the proposed mechanism. One exception is complex 9, which has a near-zero activation entropy and is proposed to undergo ligand-arm dissociation during the RDS to accommodate H2(18)O binding. These results show that the observed OAE kinetic behavior is highly dependent on the nature of the supporting ligand and are of relevance to studies of non-heme oxoiron(IV) complexes in water or acetonitrile/water mixtures for applications in photocatalysis and water oxidation chemistry.

Sugars increase non-heme iron bioavailability in human epithelial intestinal and liver cells.

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Tatiana Christides

Full Text Available Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55 increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions.

Synthesis of 5-hydroxyectoine from ectoine: crystal structure of the non-heme iron(II and 2-oxoglutarate-dependent dioxygenase EctD.

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Klaus Reuter

2010-05-01

Full Text Available As a response to high osmolality, many microorganisms synthesize various types of compatible solutes. These organic osmolytes aid in offsetting the detrimental effects of low water activity on cell physiology. One of these compatible solutes is ectoine. A sub-group of the ectoine producer's enzymatically convert this tetrahydropyrimidine into a hydroxylated derivative, 5-hydroxyectoine. This compound also functions as an effective osmostress protectant and compatible solute but it possesses properties that differ in several aspects from those of ectoine. The enzyme responsible for ectoine hydroxylation (EctD is a member of the non-heme iron(II-containing and 2-oxoglutarate-dependent dioxygenases (EC 1.14.11. These enzymes couple the decarboxylation of 2-oxoglutarate with the formation of a high-energy ferryl-oxo intermediate to catalyze the oxidation of the bound organic substrate. We report here the crystal structure of the ectoine hydroxylase EctD from the moderate halophile Virgibacillus salexigens in complex with Fe(3+ at a resolution of 1.85 A. Like other non-heme iron(II and 2-oxoglutarate dependent dioxygenases, the core of the EctD structure consists of a double-stranded beta-helix forming the main portion of the active-site of the enzyme. The positioning of the iron ligand in the active-site of EctD is mediated by an evolutionarily conserved 2-His-1-carboxylate iron-binding motif. The side chains of the three residues forming this iron-binding site protrude into a deep cavity in the EctD structure that also harbours the 2-oxoglutarate co-substrate-binding site. Database searches revealed a widespread occurrence of EctD-type proteins in members of the Bacteria but only in a single representative of the Archaea, the marine crenarchaeon Nitrosopumilus maritimus. The EctD crystal structure reported here can serve as a template to guide further biochemical and structural studies of this biotechnologically interesting enzyme family.

Production of a Heterologous Nonheme Catalase by Lactobacillus casei: an Efficient Tool for Removal of H2O2 and Protection of Lactobacillus bulgaricus from Oxidative Stress in Milk

OpenAIRE

Rochat, Tatiana; Gratadoux, Jean-Jacques; Gruss, Alexandra; Corthier, Gérard; Maguin, Emmanuelle; Langella, Philippe; van de Guchte, Maarten

2006-01-01

Lactic acid bacteria (LAB) are generally sensitive to H2O2, a compound that they can paradoxically produce themselves, as is the case for Lactobacillus bulgaricus. Lactobacillus plantarum ATCC 14431 is one of the very few LAB strains able to degrade H2O2 through the action of a nonheme, manganese-dependent catalase (hereafter called MnKat). The MnKat gene was expressed in three catalase-deficient LAB species: L. bulgaricus ATCC 11842, Lactobacillus casei BL23, and Lactococcus lactis MG1363. W...

CD and MCD studies of the effects of component B variant binding on the biferrous active site of methane monooxygenase.

Science.gov (United States)

Mitić, Natasa; Schwartz, Jennifer K; Brazeau, Brian J; Lipscomb, John D; Solomon, Edward I

2008-08-12

The multicomponent soluble form of methane monooxygenase (sMMO) catalyzes the oxidation of methane through the activation of O 2 at a nonheme biferrous center in the hydroxylase component, MMOH. Reactivity is limited without binding of the sMMO effector protein, MMOB. Past studies show that mutations of specific MMOB surface residues cause large changes in the rates of individual steps in the MMOH reaction cycle. To define the structural and mechanistic bases for these observations, CD, MCD, and VTVH MCD spectroscopies coupled with ligand-field (LF) calculations are used to elucidate changes occurring near and at the MMOH biferrous cluster upon binding of MMOB and the MMOB variants. Perturbations to both the CD and MCD are observed upon binding wild-type MMOB and the MMOB variant that similarly increases O 2 reactivity. MMOB variants that do not greatly increase O 2 reactivity fail to cause one or both of these changes. LF calculations indicate that reorientation of the terminal glutamate on Fe2 reproduces the spectral perturbations in MCD. Although this structural change allows O 2 to bridge the diiron site and shifts the redox active orbitals for good overlap, it is not sufficient for enhanced O 2 reactivity of the enzyme. Binding of the T111Y-MMOB variant to MMOH induces the MCD, but not CD changes, and causes only a small increase in reactivity. Thus, both the geometric rearrangement at Fe2 (observed in MCD) coupled with a more global conformational change that may control O 2 access (probed by CD), induced by MMOB binding, are critical factors in the reactivity of sMMO.

A study of the mechanism of action of pyridoxal isonicotinoyl hydrazone at the cellular level using reticulocytes loaded with non-heme 59Fe

International Nuclear Information System (INIS)

Huang, A.R.; Ponka, P.; McGill Univ., Montreal, Quebec; Jewish General Hospital, Montreal, Quebec

1983-01-01

Pyridoxal isonicotinoyl hydrazone (PIH) has recently been identified as a new iron chelating agent with a high degree of iron mobilizing activity in vitro and in vivo which makes this compound a candidate drug in the treatment of iron overload. This study was undertaken to elucidate the mechanism of action of the iron mobilizing activity of PIH at the cellular level. An in vitro system of rabbit reticulocytes with a high level of non-heme 59 Fe was used as a model of iron overload. The effects of various biochemical and physiological manoeuvers on the mobilization of 59 Fe by PIH from the cells were studied. The fate of [ 14 C]-PIH in the in vitro system was also studied. Studies were also carried out using a crude mitochondrial fraction. (orig./AJ)

Desaturation reactions catalyzed by soluble methane monooxygenase.

Science.gov (United States)

Jin, Y; Lipscomb, J D

2001-09-01

Soluble methane monooxygenase (MMO) is shown to be capable of catalyzing desaturation reactions in addition to the usual hydroxylation and epoxidation reactions. Dehydrogenated products are generated from MMO-catalyzed oxidation of certain substrates including ethylbenzene and cyclohexadienes. In the reaction of ethylbenzene, desaturation of ethyl C-H occurred along with the conventional hydroxvlations of ethyl and phenyl C-Hs. As a result, styrene is formed together with ethylphenols and phenylethanols. Similarly, when 1,3- and 1,4-cyclohexadienes were used as substrates, benzene was detected as a product in addition to the corresponding alcohols and epoxides. In all cases, reaction conditions were found to significantly affect the distribution among the different products. This new activity of MMO is postulated to be associated with the chemical properties of the substrates rather than fundamental changes in the nature of the oxygen and C-H activation chemistries. The formation of the desaturated products is rationalized by formation of a substrate cationic intermediate, possibly via a radical precursor. The cationic species is then proposed to partition between recombination (alcohol formation) and elimination (alkene production) pathways. This novel function of MMO indicates close mechanistic kinship between the hydroxylation and desaturation reactions catalyzed by the nonheme diiron clusters.

Moessbauer, electron paramagnetic resonance and magnetic susceptibility studies of photosensitive nitrile hydratase from Rhodococcus sp. N-771

International Nuclear Information System (INIS)

Nagamune, Teruyuki; Honda, Jun; Kobayashi, Yoshio; Sasabe, Hiroyuki; Endo, Isao; Ambe, Fumitoshi; Teratani, Yoshitaka; Hirata, Akira

1992-01-01

Moessbauer, magnetic susceptibility and electron paramagnetic resonance (EPR) studies of inactive and photoactivated NHase enzymes were performed to elucidate the electronic change of non-heme two-iron atom center of the enzyme by photoactivation. These spectroscopic investigations revealed that both the two iron atoms of the active NHase could be assigned to low-spin ferric state, and those of the inactive NHase could each be assigned to low-spin ferric and low-spin ferrous ones. From these results, it was concluded that one of the non-heme iron atoms is oxidized in the inactive NHase during photoactivation. (orig.)

Aerobic lineage of the oxidative stress response protein rubrerythrin emerged in an ancient microaerobic, (hyperthermophilic environment

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Juan Pablo Cardenas

2016-11-01

Full Text Available Rubrerythrins (RBRs are non-heme di-iron proteins belonging to the ferritin-like superfamily (FLSF. They are involved in oxidative stress defense as peroxide scavengers in a wide range of organisms. The vast majority of RBRs, including classical forms of this protein, contain a C-terminal rubredoxin-like domain involved in electron transport that is used during catalysis in anaerobic conditions. Rubredoxin is an ancient and large protein family of short length (<100 residues that contains a Fe-S center involved in electron transfer. However, functional forms of the enzyme lacking the rubredoxin-like domain have been reported (e.g., sulerythrin and ferriperoxin. In this study, phylogenomic evidence is presented that suggests that a complete lineage of rubrerythrins, lacking the rubredoxin-like domain, arose in an ancient microaerobic and (hyperthermophilic environments in the ancestors of the Archaea Thermoproteales and Sulfolobales. This lineage (termed the aerobic-type lineage subsequently evolved to become adapted to environments with progressively lower temperatures and higher oxygen concentrations via the acquisition of two co-localized genes, termed DUF3501 and RFO, encoding a conserved protein of unknown function and a predicted Fe-S oxidoreductase respectively. Proposed Horizontal Gene Transfer (HGT events from these archaeal ancestors to Bacteria expanded the opportunities for further evolution of this RBR including adaption to lower temperatures. The second lineage (termed the cyanobacterial lineage is proposed to have evolved in cyanobacterial ancestors, maybe in direct response to the production of oxygen via oxygenic photosynthesis during the Great Oxygen Event (GOE. It is hypothesized that both lineages of RBR emerged in a largely anaerobic world with whiffs of oxygen and that their subsequent independent evolutionary trajectories allowed microorganisms to transition from this anaerobic world to an aerobic one.

Alkyl Chain Growth on a Transition Metal Center: How Does Iron Compare to Ruthenium and Osmium?

Science.gov (United States)

Sainna, Mala A.; de Visser, Sam P.

2015-01-01

Industrial Fischer-Tropsch processes involve the synthesis of hydrocarbons usually on metal surface catalysts. On the other hand, very few homogeneous catalysts are known to perform a Fischer-Tropsch style of reaction. In recent work, we established the catalytic properties of a diruthenium-platinum carbene complex, [(CpRu)2(μ2-H)(μ2-NHCH3)(μ3-C)PtCH3(P(CH3)3)2](CO)n+ with n = 0, 2 and Cp = η5-C5(CH3)5, and showed it to react efficiently by initial hydrogen atom transfer followed by methyl transfer to form an alkyl chain on the Ru-center. In particular, the catalytic efficiency was shown to increase after the addition of two CO molecules. As such, this system could be viewed as a potential homogeneous Fischer-Tropsch catalyst. Herein, we have engineered the catalytic center of the catalyst and investigated the reactivity of trimetal carbene complexes of the same type using iron, ruthenium and osmium at the central metal scaffold. The work shows that the reactivity should increase from diosmium to diruthenium to diiron; however, a non-linear trend is observed due to multiple factors contributing to the individual barrier heights. We identified all individual components of these reaction steps in detail and established the difference in reactivity of the various complexes. PMID:26426009

Alkyl Chain Growth on a Transition Metal Center: How Does Iron Compare to Ruthenium and Osmium?

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Mala A. Sainna

2015-09-01

Full Text Available Industrial Fischer-Tropsch processes involve the synthesis of hydrocarbons usually on metal surface catalysts. On the other hand, very few homogeneous catalysts are known to perform a Fischer-Tropsch style of reaction. In recent work, we established the catalytic properties of a diruthenium-platinum carbene complex, [(CpRu2(μ2-H (μ2-NHCH3(μ3-CPtCH3(P(CH332](COn+ with n = 0, 2 and Cp = η5-C5(CH35, and showed it to react efficiently by initial hydrogen atom transfer followed by methyl transfer to form an alkyl chain on the Ru-center. In particular, the catalytic efficiency was shown to increase after the addition of two CO molecules. As such, this system could be viewed as a potential homogeneous Fischer-Tropsch catalyst. Herein, we have engineered the catalytic center of the catalyst and investigated the reactivity of trimetal carbene complexes of the same type using iron, ruthenium and osmium at the central metal scaffold. The work shows that the reactivity should increase from diosmium to diruthenium to diiron; however, a non-linear trend is observed due to multiple factors contributing to the individual barrier heights. We identified all individual components of these reaction steps in detail and established the difference in reactivity of the various complexes.

DFT studies of the substituent effects of dimethylamino on non-heme active oxidizing species: iron(V)-oxo species or iron(IV)-oxo acetate aminopyridine cation radical species?

Science.gov (United States)

Wang, Fang; Sun, Wei; Xia, Chungu; Wang, Yong

2017-10-01

Through the introduction of dimethylamino (Me 2 N) substituent at the pyridine ring of 2-((R)-2-[(R)-1-(pyridine-2-ylmethyl)pyrrolidin-2-yl]pyrrolidin-1-ylmethyl)pyridine (PDP) ligand, the non-heme Fe II ( Me2N PDP)/H 2 O 2 /AcOH catalyst system was found to exhibit significant higher catalytic activity and enantioselectivity than the non-substituent one in the asymmetric epoxidation experiments. The mechanistic origin of the remarkable substituent effects in these oxidation reactions has not been well established. To ascertain the potent oxidant and the related reaction mechanism, a detailed DFT calculation was performed. Interestingly, a novel Fe(IV)-oxo Me2N PDP cation radical species, [( Me2N PDP) + · Fe IV (O)(OAc)] 2+ ( Me2N 5), with about one spin spreading over the non-heme Me2N PDP ligand was formed via a carboxylic-acid-assisted O-O bond heterolysis, which is reminiscent of Compound I (an Fe(IV)(O)(porphyrin cation radical) species) in cytochrome P450 chemistry. Me2N 5 is energetically comparable with the cyclic ferric peracetate species Me2N 6, while in the pristine Fe(PDP) catalyst system, H 6 is more stable than H 5. Comparison of the activation energy for the ethylene epoxidation promoted by Me2N 5 and Me2N 6, Me2N 5 is supposed as the true oxidant triggering the epoxidation of olefins. In addition, a systematic research on the substituent effects varied from the electron-donating substituent (dMM, the substituents at sites 3, 4, and 5 of the pyridine ring: methyl, methoxyl, and methyl) to the electron-withdrawing one (CF 3 , 2,6-bis(trifluoromethyl)phenyl) on the electronic structure of the reaction intermediates has also been investigated. An alternative cyclic ferric peracetate complex is obtained, indicating that the substituents at the pyridine ring of PDP ligands have significant impacts on the electronic structure of the oxidants.

Iron and Zinc Complexes of Bulky Bis-Imidazole Ligands : Enzyme Mimicry and Ligand-Centered Redox Activity

NARCIS (Netherlands)

Folkertsma, E.

2016-01-01

The research described in this thesis is directed to the development of cheap and non-toxic iron-based homogeneous catalysts, using enzyme models and redox non-innocent ligands. Inspired by nature, the first approach focuses on the synthesis of structural models of the active site of non-heme iron

Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

Science.gov (United States)

Cappelletti, Martina; Presentato, Alessandro; Milazzo, Giorgio; Turner, Raymond J.; Fedi, Stefano; Frascari, Dario; Zannoni, Davide

2015-01-01

Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD—coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation—were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria–Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step. PMID:26029173

Design and synthesis of a tetradentate '3-amine-1-carboxylate' ligand to mimic the metal binding environment at the non-heme iron(II) oxidase active site.

Science.gov (United States)

Dungan, Victoria J; Ortin, Yannick; Mueller-Bunz, Helge; Rutledge, Peter J

2010-04-07

Non-heme iron(II) oxidases (NHIOs) catalyse a diverse array of oxidative chemistry in Nature. As part of ongoing efforts to realize biomimetic, iron-mediated C-H activation, we report the synthesis of a new 'three-amine-one-carboxylate' ligand designed to complex with iron(II) and mimic the NHIO active site. The tetradentate ligand has been prepared as a single enantiomer in nine synthetic steps from N-Cbz-L-alanine, pyridine-2,6-dimethanol and diphenylamine, using Seebach oxazolidinone chemistry to control the stereochemistry. X-Ray crystal structures are reported for two important intermediates, along with variable temperature NMR experiments to probe the hindered interconversion of conformational isomers of several key intermediates, 2,6-disubstituted pyridine derivatives. The target ligand and an N-Cbz-protected precursor were each then complexed with iron(II) and tested for their ability to promote alkene dihydroxylation, using hydrogen peroxide as the oxidant.

Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

Directory of Open Access Journals (Sweden)

Martina eCappelletti

2015-05-01

Full Text Available Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from butane metabolism. Two gene clusters, prmABCD and smoABCD – coding for soluble di-iron monooxgenases (SDIMOs involved in gaseous n-alkanes oxidation – were detected in the BCP1 genome. By means of reverse transcriptase-quantitative PCR (RT-qPCR analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids or during the cell growth on rich medium (Luria Bertani broth. The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane and/or liquid (n-hexane short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step.

Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review

OpenAIRE

Delimont, Nicole M.; Rosenkranz, Sara K.; Haub, Mark D.; Lindshield, Brian L.

2017-01-01

Background Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. Aim To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme ir...

How does tunneling contribute to counterintuitive H-abstraction reactivity of nonheme Fe(IV)O oxidants with alkanes?

Science.gov (United States)

Mandal, Debasish; Ramanan, Rajeev; Usharani, Dandamudi; Janardanan, Deepa; Wang, Binju; Shaik, Sason

2015-01-21

This article addresses the intriguing hydrogen-abstraction (H-abstraction) and oxygen-transfer (O-transfer) reactivity of a series of nonheme [Fe(IV)(O)(TMC)(Lax)](z+) complexes, with a tetramethyl cyclam ligand and a variable axial ligand (Lax), toward three substrates: 1,4-cyclohexadiene, 9,10-dihydroanthracene, and triphenyl phosphine. Experimentally, O-transfer-reactivity follows the relative electrophilicity of the complexes, whereas the corresponding H-abstraction-reactivity generally increases as the axial ligand becomes a better electron donor, hence exhibiting an antielectrophilic trend. Our theoretical results show that the antielectrophilic trend in H-abstraction is affected by tunneling contributions. Room-temperature tunneling increases with increase of the electron donation power of the axial-ligand, and this reverses the natural electrophilic trend, as revealed through calculations without tunneling, and leads to the observed antielectrophilic trend. By contrast, O-transfer-reactivity, not being subject to tunneling, retains an electrophilic-dependent reactivity trend, as revealed experimentally and computationally. Tunneling-corrected kinetic-isotope effect (KIE) calculations matched the experimental KIE values only if all of the H-abstraction reactions proceeded on the quintet state (S = 2) surface. As such, the present results corroborate the initially predicted two-state reactivity (TSR) scenario for these reactions. The increase of tunneling with the electron-releasing power of the axial ligand, and the reversal of the "natural" reactivity pattern, support the "tunneling control" hypothesis (Schreiner et al., ref 19). Should these predictions be corroborated, the entire field of C-H bond activation in bioinorganic chemistry would lay open to reinvestigation.

A non-heme iron-mediated chemical demethylation in DNA and RNA.

Science.gov (United States)

Yi, Chengqi; Yang, Cai-Guang; He, Chuan

2009-04-21

DNA methylation is arguably one of the most important chemical signals in biology. However, aberrant DNA methylation can lead to cytotoxic or mutagenic consequences. A DNA repair protein in Escherichia coli, AlkB, corrects some of the unwanted methylations of DNA bases by a unique oxidative demethylation in which the methyl carbon is liberated as formaldehyde. The enzyme also repairs exocyclic DNA lesions--that is, derivatives in which the base is augmented with an additional heterocyclic subunit--by a similar mechanism. Two proteins in humans that are homologous to AlkB, ABH2 and ABH3, repair the same spectrum of lesions; another human homologue of AlkB, FTO, is linked to obesity. In this Account, we describe our studies of AlkB, ABH2, and ABH3, including our development of a general strategy to trap homogeneous protein-DNA complexes through active-site disulfide cross-linking. AlkB uses a non-heme mononuclear iron(II) and the cofactors 2-ketoglutarate (2KG) and dioxygen to effect oxidative demethylation of the DNA base lesions 1-methyladenine (1-meA), 3-methylcytosine (3-meC), 1-methylguanine (1-meG), and 3-methylthymine (3-meT). ABH3, like AlkB, works better on single-stranded DNA (ssDNA) and is capable of repairing damaged bases in RNA. Conversely, ABH2 primarily repairs lesions in double-stranded DNA (dsDNA); it is the main housekeeping enzyme that protects the mammalian genome from 1-meA base damage. The AlkB-family proteins have moderate affinities for their substrates and bind DNA in a non-sequence-specific manner. Knowing that these proteins flip the damaged base out from the duplex DNA and insert it into the active site for further processing, we first engineered a disulfide cross-link in the active site to stabilize the Michaelis complex. Based on the detailed structural information afforded by the active-site cross-linked structures, we can readily install a cross-link away from the active site to obtain the native-like structures of these complexes

Water oxidation catalysis with nonheme iron complexes under acidic and basic conditions: homogeneous or heterogeneous?

Science.gov (United States)

Hong, Dachao; Mandal, Sukanta; Yamada, Yusuke; Lee, Yong-Min; Nam, Wonwoo; Llobet, Antoni; Fukuzumi, Shunichi

2013-08-19

Thermal water oxidation by cerium(IV) ammonium nitrate (CAN) was catalyzed by nonheme iron complexes, such as Fe(BQEN)(OTf)2 (1) and Fe(BQCN)(OTf)2 (2) (BQEN = N,N'-dimethyl-N,N'-bis(8-quinolyl)ethane-1,2-diamine, BQCN = N,N'-dimethyl-N,N'-bis(8-quinolyl)cyclohexanediamine, OTf = CF3SO3(-)) in a nonbuffered aqueous solution; turnover numbers of 80 ± 10 and 20 ± 5 were obtained in the O2 evolution reaction by 1 and 2, respectively. The ligand dissociation of the iron complexes was observed under acidic conditions, and the dissociated ligands were oxidized by CAN to yield CO2. We also observed that 1 was converted to an iron(IV)-oxo complex during the water oxidation in competition with the ligand oxidation. In addition, oxygen exchange between the iron(IV)-oxo complex and H2(18)O was found to occur at a much faster rate than the oxygen evolution. These results indicate that the iron complexes act as the true homogeneous catalyst for water oxidation by CAN at low pHs. In contrast, light-driven water oxidation using [Ru(bpy)3](2+) (bpy = 2,2'-bipyridine) as a photosensitizer and S2O8(2-) as a sacrificial electron acceptor was catalyzed by iron hydroxide nanoparticles derived from the iron complexes under basic conditions as the result of the ligand dissociation. In a buffer solution (initial pH 9.0) formation of the iron hydroxide nanoparticles with a size of around 100 nm at the end of the reaction was monitored by dynamic light scattering (DLS) in situ and characterized by X-ray photoelectron spectra (XPS) and transmission electron microscope (TEM) measurements. We thus conclude that the water oxidation by CAN was catalyzed by short-lived homogeneous iron complexes under acidic conditions, whereas iron hydroxide nanoparticles derived from iron complexes act as a heterogeneous catalyst in the light-driven water oxidation reaction under basic conditions.

Fragment molecular orbital study on electron tunneling mechanisms in bacterial photosynthetic reaction center.

Science.gov (United States)

Kitoh-Nishioka, Hirotaka; Ando, Koji

2012-11-01

The tunneling mechanisms of electron transfers (ETs) in photosynthetic reaction center of Blastochloris viridis are studied by the ab initio fragment molecular orbital (FMO) method combined with the generalized Mulliken-Hush (GMH) and the bridge Green function (GF) calculations of the electronic coupling T(DA) and the tunneling current method for the ET pathway analysis at the fragment-based resolution. For the ET from batctriopheophytin (H(L)) to menaquinone (MQ), a major tunneling current through Trp M250 and a minor back flow via Ala M215, Ala M216, and His M217 are quantified. For the ET from MQ to ubiquinone, the major tunneling pathway via the nonheme Fe(2+) and His L190 is identified as well as minor pathway via His M217 and small back flows involving His L230, Glu M232, and His M264. At the given molecular structure from X-ray experiment, the spin state of the Fe(2+) ion, its replacement by Zn(2+), or its removal are found to affect the T(DA) value by factors within 2.2. The calculated T(DA) values, together with experimentally estimated values of the driving force and the reorganization energy, give the ET rates in reasonable agreement with experiments.

Characterization and two-dimensional crystallization of membrane component AlkB of the medium-chain alkane hydroxylase system from Pseudomonas putida GPo1.

Science.gov (United States)

Alonso, Hernan; Roujeinikova, Anna

2012-11-01

The alkane hydroxylase system of Pseudomonas putida GPo1 allows it to use alkanes as the sole source of carbon and energy. Bacterial alkane hydroxylases have tremendous potential as biocatalysts for the stereo- and regioselective transformation of a wide range of chemically inert unreactive alkanes into valuable reactive chemical precursors. We have produced and characterized the first 2-dimensional crystals of the integral membrane component of the P. putida alkane hydroxylase system, the nonheme di-iron alkane monooxygenase AlkB. Our analysis reveals for the first time that AlkB reconstituted into a lipid bilayer forms trimers. Addition of detergents that do not disrupt the AlkB oligomeric state (decyl maltose neopentyl glycol [DMNG], lauryl maltose neopentyl glycol [LMNG], and octaethylene glycol monododecyl ether [C(12)E(8)]) preserved its activity at a level close to that of the detergent-free control sample. In contrast, the monomeric form of AlkB produced by purification in n-decyl-β-D-maltopyranoside (DM), n-dodecyl-β-D-maltopyranoside (DDM), octyl glucose neopentyl glycol (OGNG), and n-dodecyl-N,N-dimethylamine-N-oxide (LDAO) was largely inactive. This is the first indication that the physiologically active form of membrane-embedded AlkB may be a multimer. We present for the first time experimental evidence that 1-octyne acts as a mechanism-based inhibitor of AlkB. Therefore, despite the lack of any significant full-length sequence similarity with members of other monooxygenase classes that catalyze the terminal oxidation of alkanes, AlkB is likely to share a similar catalytic mechanism.

Redox reactions of [FeFe]-hydrogenase models containing an internal amine and a pendant phosphine.

Science.gov (United States)

Zheng, Dehua; Wang, Mei; Chen, Lin; Wang, Ning; Sun, Licheng

2014-02-03

A diiron dithiolate complex with a pendant phosphine coordinated to one of the iron centers, [(μ-SCH2)2N(CH2C6H4-o-PPh2){Fe2(CO)5}] (1), was prepared and structurally characterized. The pendant phosphine is dissociated together with a CO ligand in the presence of excess PMe3, to afford [(μ-SCH2)2N(CH2C6H4-o-PPh2){Fe(CO)2(PMe3)}2] (2). Redox reactions of 2 and related complexes were studied in detail by in situ IR spectroscopy. A series of new Fe(II)Fe(I) ([3](+) and [6](+)), Fe(II)Fe(II) ([4](2+)), and Fe(I)Fe(I) (5) complexes relevant to Hox, Hox(CO), and Hred states of the [FeFe]-hydrogenase active site were detected. Among these complexes, the molecular structures of the diferrous complex [4](2+) with the internal amine and the pendant phosphine co-coordinated to the same iron center and the triphosphine diiron complex 5 were determined by X-ray crystallography. To make a comparison, the redox reactions of an analogous complex, [(μ-SCH2)2N(CH2C6H5){Fe(CO)2(PMe3)}2] (7), were also investigated by in situ IR spectroscopy in the absence or presence of extrinsic PPh3, which has no influence on the oxidation reaction of 7. The pendant phosphine in the second coordination sphere makes the redox reaction of 2 different from that of its analogue 7.

The catalase activity of diiron adenine deaminase

Energy Technology Data Exchange (ETDEWEB)

Kamat S. S.; Swaminathan S.; Holmes-Hampton, G. P.; Bagaria, A.; Kumaran, D.; Tichy, S. E.; Gheyi, T.; Zheng, X.; Bain, K.; Groshong, C.; Emtage, S.; Sauder, J. M.; Burley, S. K.; Lindahl, P. A.; Raushel, F. M.

2011-12-01

Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron was sequestered with a metal chelator and the growth medium supplemented with Mn{sup 2+} before induction, the post-translational modifications disappeared. Enzyme expressed and purified under these conditions was substantially more active for adenine deamination. Apo-enzyme was prepared and reconstituted with two equivalents of FeSO{sub 4}. Inductively coupled plasma mass spectrometry and Moessbauer spectroscopy demonstrated that this protein contained two high-spin ferrous ions per monomer of ADE. In addition to the adenine deaminase activity, [Fe{sup II}/Fe{sup II}]-ADE catalyzed the conversion of H{sub 2}O{sub 2} to O{sub 2} and H{sub 2}O. The values of k{sub cat} and k{sub cat}/K{sub m} for the catalase activity are 200 s{sup -1} and 2.4 x 10{sup 4} M{sup -1} s{sup -1}, respectively. [Fe{sup II}/Fe{sup II}]-ADE underwent more than 100 turnovers with H{sub 2}O{sub 2} before the enzyme was inactivated due to oxygenation of histidine residues critical for metal binding. The iron in the inactive enzyme was high-spin ferric with g{sub ave} = 4.3 EPR signal and no evidence of anti-ferromagnetic spin-coupling. A model is proposed for the disproportionation of H{sub 2}O{sub 2} by [Fe{sup II}/Fe{sup II}]-ADE that involves the cycling of the binuclear metal center between the di-ferric and di-ferrous oxidation states. Oxygenation of active site residues occurs via release of hydroxyl radicals. These findings represent the first report of redox reaction catalysis by any member of the AHS.

2 : 2 Fe(III): ligand and "adamantane core" 4 : 2 Fe(III): ligand (hydr)oxo complexes of an acyclic ditopic ligand

DEFF Research Database (Denmark)

Ghiladi, Morten; Larsen, Frank B.; McKenzie, Christine J.

2005-01-01

A bis-hydroxo-bridged diiron(III) complex and a bis-mu-oxo-bis-mu-hydroxo-bridged tetrairon( III) complex are isolated from the reaction of 2,6-bis((N, N'-bis-(2-picolyl) amino) methyl)-4-tert-butylphenol (Hbpbp) with iron perchlorate in acidic and neutral solutions respectively. The X-ray struct......A bis-hydroxo-bridged diiron(III) complex and a bis-mu-oxo-bis-mu-hydroxo-bridged tetrairon( III) complex are isolated from the reaction of 2,6-bis((N, N'-bis-(2-picolyl) amino) methyl)-4-tert-butylphenol (Hbpbp) with iron perchlorate in acidic and neutral solutions respectively. The X...

Deficiency of α-1-antitrypsin influences systemic iron homeostasis

Directory of Open Access Journals (Sweden)

Ghio AJ

2013-01-01

Full Text Available Andrew J Ghio,1 Joleen M Soukup,1 Judy H Richards,1 Bernard M Fischer,2 Judith A Voynow,2 Donald E Schmechel31US Environmental Protection Agency, Chapel Hill, NC, USA; 2Division of Pediatric Pulmonary Medicine, Department of Pediatrics,3Joseph and Kathleen Bryan Alzheimer Disease Research Center, Department of Medicine (Neurology, Duke University Medical Center, Durham, NC, USAAbstract: There is evidence that proteases and antiproteases participate in the iron homeostasis of cells and living systems. We tested the postulate that α-1 antitrypsin (A1AT polymorphism and the consequent deficiency of this antiprotease in humans are associated with a systemic disruption in iron homeostasis. Archived plasma samples from Alpha-1 Foundation (30 MM, 30 MZ, and 30 ZZ individuals were analyzed for A1AT, ferritin, transferrin, and C-reactive protein (CRP. Plasma samples were also assayed for metals using inductively coupled plasma atomic emission spectroscopy (ICPAES. Plasma levels of A1AT in MZ and ZZ individuals were approximately 60% and 20% of those for MM individuals respectively. Plasma ferritin concentrations in those with the ZZ genotype were greater relative to those individuals with either MM or MZ genotype. Plasma transferrin for MM, MZ, and ZZ genotypes showed no significant differences. Linear regression analysis revealed a significant (negative relationship between plasma concentrations of A1AT and ferritin while that between A1AT and transferrin levels was not significant. Plasma CRP concentrations were not significantly different between MM, MZ, and ZZ individuals. ICPAES measurement of metals confirmed elevated plasma concentrations of nonheme iron among ZZ individuals. Nonheme iron concentrations correlated (negatively with levels of A1AT. A1AT deficiency is associated with evidence of a disruption in iron homeostasis with plasma ferritin and nonheme iron concentrations being elevated among those with the ZZ genotype.Keywords: α-1

Production of a heterologous nonheme catalase by Lactobacillus casei: an efficient tool for removal of H2O2 and protection of Lactobacillus bulgaricus from oxidative stress in milk.

Science.gov (United States)

Rochat, Tatiana; Gratadoux, Jean-Jacques; Gruss, Alexandra; Corthier, Gérard; Maguin, Emmanuelle; Langella, Philippe; van de Guchte, Maarten

2006-08-01

Lactic acid bacteria (LAB) are generally sensitive to H2O2, a compound that they can paradoxically produce themselves, as is the case for Lactobacillus bulgaricus. Lactobacillus plantarum ATCC 14431 is one of the very few LAB strains able to degrade H2O2 through the action of a nonheme, manganese-dependent catalase (hereafter called MnKat). The MnKat gene was expressed in three catalase-deficient LAB species: L. bulgaricus ATCC 11842, Lactobacillus casei BL23, and Lactococcus lactis MG1363. While the protein could be detected in all heterologous hosts, enzyme activity was observed only in L. casei. This is probably due to the differences in the Mn contents of the cells, which are reportedly similar in L. plantarum and L. casei but at least 10- and 100-fold lower in Lactococcus lactis and L. bulgaricus, respectively. The expression of the MnKat gene in L. casei conferred enhanced oxidative stress resistance, as measured by an increase in the survival rate after exposure to H2O2, and improved long-term survival in aerated cultures. In mixtures of L. casei producing MnKat and L. bulgaricus, L. casei can eliminate H2O2 from the culture medium, thereby protecting both L. casei and L. bulgaricus from its deleterious effects.

Protonation/reduction dynamics at the [4Fe-4S] cluster of the hydrogen-forming cofactor in [FeFe]-hydrogenases.

Science.gov (United States)

Senger, Moritz; Mebs, Stefan; Duan, Jifu; Shulenina, Olga; Laun, Konstantin; Kertess, Leonie; Wittkamp, Florian; Apfel, Ulf-Peter; Happe, Thomas; Winkler, Martin; Haumann, Michael; Stripp, Sven T

2018-01-31

The [FeFe]-hydrogenases of bacteria and algae are the most efficient hydrogen conversion catalysts in nature. Their active-site cofactor (H-cluster) comprises a [4Fe-4S] cluster linked to a unique diiron site that binds three carbon monoxide (CO) and two cyanide (CN - ) ligands. Understanding microbial hydrogen conversion requires elucidation of the interplay of proton and electron transfer events at the H-cluster. We performed real-time spectroscopy on [FeFe]-hydrogenase protein films under controlled variation of atmospheric gas composition, sample pH, and reductant concentration. Attenuated total reflection Fourier-transform infrared spectroscopy was used to monitor shifts of the CO/CN - vibrational bands in response to redox and protonation changes. Three different [FeFe]-hydrogenases and several protein and cofactor variants were compared, including element and isotopic exchange studies. A protonated equivalent (HoxH) of the oxidized state (Hox) was found, which preferentially accumulated at acidic pH and under reducing conditions. We show that the one-electron reduced state Hred' represents an intrinsically protonated species. Interestingly, the formation of HoxH and Hred' was independent of the established proton pathway to the diiron site. Quantum chemical calculations of the respective CO/CN - infrared band patterns favored a cysteine ligand of the [4Fe-4S] cluster as the protonation site in HoxH and Hred'. We propose that proton-coupled electron transfer facilitates reduction of the [4Fe-4S] cluster and prevents premature formation of a hydride at the catalytic diiron site. Our findings imply that protonation events both at the [4Fe-4S] cluster and at the diiron site of the H-cluster are important in the hydrogen conversion reaction of [FeFe]-hydrogenases.

Alteration by irradiation and storage at amount of heme iron in poultry meat; Alteracoes provocadas pela irradiacao e armazenamento nos teores de ferro heme em carne de frango

Energy Technology Data Exchange (ETDEWEB)

Souza, Adriana Regia Marques de; Arthur, Valter Arthur [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia; Canniatti-Brazaca, Solange Guidolin [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao]. E-mail: sgcbraza@esalq.usp.br

2007-04-15

Studies of irradiation and storage effects in chicken were carried out to discover the influence in iron heme, non-heme amount, color and total pigments. Chicken thighs and chicken breast were studied. These were irradiated to 0, 1 and 2 kGy stored by 14 days to 4 deg C in refrigerator. Determining the heme content and non-heme of meat was done using the colorimeter method and the Ferrozine reagent. The values of iron heme were influenced both by the irradiation and the storage, reducing the amount throughout the course of time. The iron non-heme was also influenced by the doses and the storage time, however the values increased throughout the course of time, because of the conversion of iron heme in non-heme. The color did not show that it was influenced by the studied doses, except for the storage, and the total number of pigments was affected by the irradiation and the time, reducing the values with the increase of storage. Irradiation was shown to be a good method to conserve iron. (author)

Alteration by irradiation and storage at amount of heme iron in poultry meat

International Nuclear Information System (INIS)

Souza, A.R.M. de; Arthur, V.; Canniatti-Brazaca, S.G.

2007-01-01

Studies of irradiation and storage effects in chicken were carried out to discover the influence in iron heme, non-heme amount, color and total pigments. Chicken thighs and chicken breast were studied. These were irradiated to 0, 1 and 2 kGy stored by 14 days to 4 °C in refrigerator. Determining the heme content and non-heme of meat was done using the colorimeter method and the Ferrozine reagent. The values of iron heme were influenced both by the irradiation and the storage, reducing the amount throughout the course of time. The iron non-heme was also influenced by the doses and the storage time, however the values increased throughout the course of time, because of the conversion of iron heme in non-heme. The color did not show that it was influenced by the studied doses, except for the storage, and the total number of pigments was affected by the irradiation and the time, reducing the values with the increase of storage. Irradiation was shown to be a good method to conserve iron. (author) [pt

Alteration by irradiation and storage at amount of heme iron in poultry meat

International Nuclear Information System (INIS)

Souza, Adriana Regia Marques de; Arthur, Valter Arthur; Canniatti-Brazaca, Solange Guidolin

2007-01-01

Studies of irradiation and storage effects in chicken were carried out to discover the influence in iron heme, non-heme amount, color and total pigments. Chicken thighs and chicken breast were studied. These were irradiated to 0, 1 and 2 kGy stored by 14 days to 4 deg C in refrigerator. Determining the heme content and non-heme of meat was done using the colorimeter method and the Ferrozine reagent. The values of iron heme were influenced both by the irradiation and the storage, reducing the amount throughout the course of time. The iron non-heme was also influenced by the doses and the storage time, however the values increased throughout the course of time, because of the conversion of iron heme in non-heme. The color did not show that it was influenced by the studied doses, except for the storage, and the total number of pigments was affected by the irradiation and the time, reducing the values with the increase of storage. Irradiation was shown to be a good method to conserve iron. (author)

Differences and Comparisons of the Properties and Reactivities of Iron(III)–hydroperoxo Complexes with Saturated Coordination Sphere

Science.gov (United States)

Faponle, Abayomi S; Quesne, Matthew G; Sastri, Chivukula V; Banse, Frédéric; de Visser, Sam P

2015-01-01

Heme and nonheme monoxygenases and dioxygenases catalyze important oxygen atom transfer reactions to substrates in the body. It is now well established that the cytochrome P450 enzymes react through the formation of a high-valent iron(IV)–oxo heme cation radical. Its precursor in the catalytic cycle, the iron(III)–hydroperoxo complex, was tested for catalytic activity and found to be a sluggish oxidant of hydroxylation, epoxidation and sulfoxidation reactions. In a recent twist of events, evidence has emerged of several nonheme iron(III)–hydroperoxo complexes that appear to react with substrates via oxygen atom transfer processes. Although it was not clear from these studies whether the iron(III)–hydroperoxo reacted directly with substrates or that an initial O–O bond cleavage preceded the reaction. Clearly, the catalytic activity of heme and nonheme iron(III)–hydroperoxo complexes is substantially different, but the origins of this are still poorly understood and warrant a detailed analysis. In this work, an extensive computational analysis of aromatic hydroxylation by biomimetic nonheme and heme iron systems is presented, starting from an iron(III)–hydroperoxo complex with pentadentate ligand system (L52). Direct C–O bond formation by an iron(III)–hydroperoxo complex is investigated, as well as the initial heterolytic and homolytic bond cleavage of the hydroperoxo group. The calculations show that [(L52)FeIII(OOH)]2+ should be able to initiate an aromatic hydroxylation process, although a low-energy homolytic cleavage pathway is only slightly higher in energy. A detailed valence bond and thermochemical analysis rationalizes the differences in chemical reactivity of heme and nonheme iron(III)–hydroperoxo and show that the main reason for this particular nonheme complex to be reactive comes from the fact that they homolytically split the O–O bond, whereas a heterolytic O–O bond breaking in heme iron(III)–hydroperoxo is found. PMID:25399782

Enhanced photocatalytic hydrogen production from an MCM-41-immobilized photosensitizer-[Fe-Fe] hydrogenase mimic dyad.

Science.gov (United States)

Wang, Wen; Yu, Tianjun; Zeng, Yi; Chen, Jinping; Yang, Guoqiang; Li, Yi

2014-11-01

A covalently linked photosensitizer-catalytic center dyad Ps-Hy, consisting of two bis(2-phenylpyridine)(2,2'-bipyridine)iridium(iii) chromophores (Ps) and a diiron hydrogenase mimic (Hy) was constructed by using click reaction. Ps-Hy was incorporated into K(+)-exchanged molecular sieve MCM-41 to form a composite (Ps-Hy@MCM-41), which has been successfully applied to the photochemical production of hydrogen. The catalytic activity of Ps-Hy@MCM-41 is ∼3-fold higher as compared with that of Ps-Hy in the absence of MCM-41. The incorporation of Ps-Hy into MCM-41 stabilizes the catalyst, and consequently, advances the photocatalysis. The present study provides a potential strategy for improving catalytic efficiency of artificial photosynthesis systems using mesoporous molecular sieves.

Improvement of bioavailability for iron from vegetarian meals by ascorbic acid

International Nuclear Information System (INIS)

Sritongkul, N.; Tuntawiroon, M.; Pleehachinda, R.; Suwanik, R.

1996-01-01

There are two kinds of iron in the diet with respect to the mechanism of absorption, heme-iron which is present as haemoglobin or myoglobin in meat and blood products, and, non-heme iron which is the main source of dietary iron. The bioavailability of the non-heme food iron is much lower than heme-iron. Vegetarian diets contain only non-heme iron. Iron intake from vegetarian meals are generally satisfied with the requirements, however, the bioavailabilities for non-heme iron is determined not only by iron content byt also the balance between different dietary factors enhancing and inhibiting iron absorption. The main enhancing factor in vegetarian meals is ascorbic acid in fruits and vegetables, inhibitors are phytate in cereals and grains, and tannins in some spices and vegetables. It has been reported that iron deficiency is one of the common micronutrient problems associated with unplanned vegetarian diets. In the present study the absorption of non-heme iron was measured from 2 vegetarian meals containing considerable amounts of phytate and tannin. The extrinsic tay method ( 59 Fe/ 55 Fe) was used to labelled the non-heme iron. The mean percentage absorption of non-heme iron from both meals was slightly different due to differences in their dietary contents. Their initial percentages iron absorption were apparent low (3.5% and 4.1%), however, the absorption progressively increased with increase in the level of ascorbic acid, 2-3 times with 100 mg and 4-5 times with 200 mg of ascorbic acid. The average amount of iron absorbed per 2000 kcal increased from 0.37 mg to 0.86 mg and 1.45 mg with the addition of 100 mg and 200 mg ascorbic acid respectively (p < 0.001). Considering the limited caloric intakes and the iron content in the meals, the amount of iron absorbed from vegetarian meals without ascorbic acid was not able to meet certain requirements for children, adolescents and menstruating women. The minimal requirement for dietary iron needed to be absorbed is

Improvement of bioavailability for iron from vegetarian meals by ascorbic acid

Energy Technology Data Exchange (ETDEWEB)

Sritongkul, N; Tuntawiroon, M; Pleehachinda, R; Suwanik, R [Siriraj Hospital Medical School, Bangkok (Thailand). Section of Nuclear Medicine

1996-12-01

There are two kinds of iron in the diet with respect to the mechanism of absorption, heme-iron which is present as haemoglobin or myoglobin in meat and blood products, and, non-heme iron which is the main source of dietary iron. The bioavailability of the non-heme food iron is much lower than heme-iron. Vegetarian diets contain only non-heme iron. Iron intake from vegetarian meals are generally satisfied with the requirements, however, the bioavailabilities for non-heme iron is determined not only by iron content byt also the balance between different dietary factors enhancing and inhibiting iron absorption. The main enhancing factor in vegetarian meals is ascorbic acid in fruits and vegetables, inhibitors are phytate in cereals and grains, and tannins in some spices and vegetables. It has been reported that iron deficiency is one of the common micronutrient problems associated with unplanned vegetarian diets. In the present study the absorption of non-heme iron was measured from 2 vegetarian meals containing considerable amounts of phytate and tannin. The extrinsic tay method ({sup 59}Fe/ {sup 55}Fe) was used to labelled the non-heme iron. The mean percentage absorption of non-heme iron from both meals was slightly different due to differences in their dietary contents. Their initial percentages iron absorption were apparent low (3.5% and 4.1%), however, the absorption progressively increased with increase in the level of ascorbic acid, 2-3 times with 100 mg and 4-5 times with 200 mg of ascorbic acid. The average amount of iron absorbed per 2000 kcal increased from 0.37 mg to 0.86 mg and 1.45 mg with the addition of 100 mg and 200 mg ascorbic acid respectively (p < 0.001). Considering the limited caloric intakes and the iron content in the meals, the amount of iron absorbed from vegetarian meals without ascorbic acid was not able to meet certain requirements for children, adolescents and menstruating women. The minimal requirement for dietary iron needed to be

Duodenal Cytochrome b (DCYTB in Iron Metabolism: An Update on Function and Regulation

Directory of Open Access Journals (Sweden)

Darius J. R. Lane

2015-03-01

Full Text Available Iron and ascorbate are vital cellular constituents in mammalian systems. The bulk-requirement for iron is during erythropoiesis leading to the generation of hemoglobin-containing erythrocytes. Additionally; both iron and ascorbate are required as co-factors in numerous metabolic reactions. Iron homeostasis is controlled at the level of uptake; rather than excretion. Accumulating evidence strongly suggests that in addition to the known ability of dietary ascorbate to enhance non-heme iron absorption in the gut; ascorbate regulates iron homeostasis. The involvement of ascorbate in dietary iron absorption extends beyond the direct chemical reduction of non-heme iron by dietary ascorbate. Among other activities; intra-enterocyte ascorbate appears to be involved in the provision of electrons to a family of trans-membrane redox enzymes; namely those of the cytochrome b561 class. These hemoproteins oxidize a pool of ascorbate on one side of the membrane in order to reduce an electron acceptor (e.g., non-heme iron on the opposite side of the membrane. One member of this family; duodenal cytochrome b (DCYTB; may play an important role in ascorbate-dependent reduction of non-heme iron in the gut prior to uptake by ferrous-iron transporters. This review discusses the emerging relationship between cellular iron homeostasis; the emergent “IRP1-HIF2α axis”; DCYTB and ascorbate in relation to iron metabolism.

Bio-inspired Iron Catalysts for Hydrocarbon Oxidations

Energy Technology Data Exchange (ETDEWEB)

Que, Jr., Lawrence [Univ. of Minnesota, Minneapolis, MN (United States)

2016-03-22

Stereoselective oxidation of C–H and C=C bonds are catalyzed by nonheme iron enzymes. Inspired by these bioinorganic systems, our group has been exploring the use of nonheme iron complexes as catalysts for the oxidation of hydrocarbons using H2O2 as an environmentally friendly and atom-efficient oxidant in order to gain mechanistic insights into these novel transformations. In particular, we have focused on clarifying the nature of the high-valent iron oxidants likely to be involved in these transformations.

Remote control of regioselectivity in acyl-acyl carrier protein-desaturases.

Science.gov (United States)

Guy, Jodie E; Whittle, Edward; Moche, Martin; Lengqvist, Johan; Lindqvist, Ylva; Shanklin, John

2011-10-04

Regiospecific desaturation of long-chain saturated fatty acids has been described as approaching the limits of the discriminatory power of enzymes because the substrate entirely lacks distinguishing features close to the site of dehydrogenation. To identify the elusive mechanism underlying regioselectivity, we have determined two crystal structures of the archetypal Δ9 desaturase from castor in complex with acyl carrier protein (ACP), which show the bound ACP ideally situated to position C9 and C10 of the acyl chain adjacent to the diiron active site for Δ9 desaturation. Analysis of the structures and modeling of the complex between the highly homologous ivy Δ4 desaturase and ACP, identified a residue located at the entrance to the binding cavity, Asp280 in the castor desaturase (Lys275 in the ivy desaturase), which is strictly conserved within Δ9 and Δ4 enzymes but differs between them. We hypothesized that interaction between Lys275 and the phosphate of the pantetheine, seen in the ivy model, is key to positioning C4 and C5 adjacent to the diiron center for Δ4 desaturation. Mutating castor Asp280 to Lys resulted in a major shift from Δ9 to Δ4 desaturation. Thus, interaction between desaturase side-chain 280 and phospho-serine 38 of ACP, approximately 27 Å from the site of double-bond formation, predisposes ACP binding that favors either Δ9 or Δ4 desaturation via repulsion (acidic side chain) or attraction (positively charged side chain), respectively. Understanding the mechanism underlying remote control of regioselectivity provides the foundation for reengineering desaturase enzymes to create designer chemical feedstocks that would provide alternatives to those currently obtained from petrochemicals.

Bis(diphenylphosphino)ferrocene substituted diiron complexes

Indian Academy of Sciences (India)

sources. However, the wide application of hydrogen as a fuel is limited owing to the high cost associated with its production. Hence, scientists have been look- .... Å) at 150(2) K. The structure was solved and refined. Table 1. Crystallographic data for 4. 4. Formula. C46H34Fe3O6P2S2. Mr. 976.34 crystal system triclinic.

Hydrogen Activation by Biomimetic Diiron Dithiolates

Science.gov (United States)

Olsen, Matthew T.; Barton, Bryan E.; Rauchfuss, Thomas B.

2009-01-01

Using the thermally stable salts of [Fe2(SR)2(CO)3(PMe3)(dppv)]BArF4, we found that the azadithiolates [Fe2(adtR)(CO)3(PMe3)(dppv)]+ react with high pressures of H2 to give the hydride [(μ-H)Fe2(adt)(CO)3(PMe3)(dppv)]BArF4. The related oxadithiolate and propanedithiolate complexes are unreactive toward H2. Molecular hydrogen is proposed to undergo heterolysis assisted by the amine followed by isomerization of an initially formed terminal hydride. Use of H2 and D2O gave the deuteride as well as the hydride, implicating protic intermediates. PMID:19603776

Iron accumulation with age, oxidative stress and functional decline.

Directory of Open Access Journals (Sweden)

Jinze Xu

2008-08-01

Full Text Available Identification of biological mediators in sarcopenia is pertinent to the development of targeted interventions to alleviate this condition. Iron is recognized as a potent pro-oxidant and a catalyst for the formation of reactive oxygen species in biological systems. It is well accepted that iron accumulates with senescence in several organs, but little is known about iron accumulation in muscle and how it may affect muscle function. In addition, it is unclear if interventions which reduced age-related loss of muscle quality, such as calorie restriction, impact iron accumulation. We investigated non-heme iron concentration, oxidative stress to nucleic acids in gastrocnemius muscle and key indices of sarcopenia (muscle mass and grip strength in male Fischer 344 X Brown Norway rats fed ad libitum (AL or a calorie restricted diet (60% of ad libitum food intake starting at 4 months of age at 8, 18, 29 and 37 months of age. Total non-heme iron levels in the gastrocnemius muscle of AL rats increased progressively with age. Between 29 and 37 months of age, the non-heme iron concentration increased by approximately 200% in AL-fed rats. Most importantly, the levels of oxidized RNA in gastrocnemius muscle of AL rats were significantly increased as well. The striking age-associated increase in non-heme iron and oxidized RNA levels and decrease in sarcopenia indices were all attenuated in the calorie restriction (CR rats. These findings strongly suggest that the age-related iron accumulation in muscle contributes to increased oxidative damage and sarcopenia, and that CR effectively attenuates these negative effects.

Identification of residues important for the activity of aldehyde-deformylating oxygenase through investigation into the structure-activity relationship.

Science.gov (United States)

Wang, Qing; Bao, Luyao; Jia, Chenjun; Li, Mei; Li, Jian-Jun; Lu, Xuefeng

2017-03-16

Aldehyde-deformylating oxygenase (ADO) is a key enzyme involved in the biosynthetic pathway of fatty alk(a/e)nes in cyanobacteria. However, cADO (cyanobacterial ADO) showed extreme low activity with the k cat value below 1 min -1 , which would limit its application in biofuel production. To identify the activity related key residues of cADO is urgently required. The amino acid residues which might affect cADO activity were identified based on the crystal structures and sequence alignment of cADOs, including the residues close to the di-iron center (Tyr39, Arg62, Gln110, Tyr122, Asp143 of cADO-1593), the protein surface (Trp 178 of cADO-1593), and those involved in two important hydrogen bonds (Gln49, Asn123 of cADO-1593, and Asp49, Asn123 of cADO-sll0208) and in the oligopeptide whose conformation changed in the absence of the di-iron center (Leu146, Asn149, Phe150 of cADO-1593, and Thr146, Leu148, Tyr150 of cADO-sll0208). The variants of cADO-1593 from Synechococcus elongatus PCC7942 and cADO-sll0208 from Synechocystis sp. PCC6803 were constructed, overexpressed, purified and kinetically characterized. The k cat values of L146T, Q49H/N123H/F150Y and W178R of cADO-1593 and L148R of cADO-sll0208 were increased by more than two-fold, whereas that of R62A dropped by 91.1%. N123H, Y39F and D143A of cADO-1593, and Y150F of cADO-sll0208 reduced activities by ≤ 20%. Some important amino acids, which exerted some effects on cADO activity, were identified. Several enzyme variants exhibited greatly reduced activity, while the k cat values of several mutants are more than two-fold higher than the wild type. This study presents the report on the relationship between amino acid residues and enzyme activity of cADOs, and the information will provide a guide for enhancement of cADO activity through protein engineering.

Stern-Center Potsdam; Stern-Center Potsdam

Energy Technology Data Exchange (ETDEWEB)

Anon.

1999-07-01

The ''Stern-Center Potsdam'' is a star-shaped shopping mall in the city center. [German] Das Stern-Center in Potsdam bietet als Einkaufszentrum vor den Toren Berlins Platz fuer eine Vielzahl von Geschaeften. Die sternfoermige Gebaeudestruktur des Centers bildet den Mittelpunkt des Stadtviertels 'Am Stern'. (orig.)

Information sharing guidebook for transportation management centers, emergency operations centers, and fusion centers

Science.gov (United States)

2010-06-01

This guidebook provides an overview of the mission and functions of transportation management centers, emergency operations centers, and fusion centers. The guidebook focuses on the types of information these centers produce and manage and how the sh...

Information sharing guidebook for transportation management centers, emergency operations centers, and fusion centers.

Science.gov (United States)

2010-06-01

This guidebook provides an overview of the mission and functions of transportation management centers, emergency operations centers, and fusion centers. The guidebook focuses on the types of information these centers produce and manage and how the sh...

Iowa Water Center | Iowa Water Center

Science.gov (United States)

Home Iowa State University Extension Iowa Water Center Submitted by mollyd on April 24, 2012 - 09 :42 Advancing the state of water knowledge and management The Iowa Water Center is a part of a nationwide network of university-based water centers created to encourage interdisciplinary water research

User-Centered Design through Learner-Centered Instruction

Science.gov (United States)

Altay, Burçak

2014-01-01

This article initially demonstrates the parallels between the learner-centered approach in education and the user-centered approach in design disciplines. Afterward, a course on human factors that applies learner-centered methods to teach user-centered design is introduced. The focus is on three tasks to identify the application of theoretical and…

Recombination luminescence from H centers and conversion of H centers into I centers in alkali iodides

International Nuclear Information System (INIS)

Berzina, B.J.

1981-01-01

The study is aimed at the search for H-plus-electron centers of luminescence and the investigation of the conversion of H- into I centers by the luminescence of H-plus-electron centers in alkali iodide crystals. KI, RbI and NaI crystals were studied at 12 K. H and F centers were created by irradiation with ultraviolet light corresponding to the absorption band of anion excitons. Then the excitation of electron centers by red light irradiation was followed. The spectra of stimulated recombination luminescence were studied. The luminescence of H-plus- electron centers had been observed and the conclusion was made that this center was formed on immobile H centers. In case of stable H centers the optically stimulated conversion of H centers into I centers occurs. The assumption is advanced on the spontaneous annihilation of near placed unstable F, H centers which leads to the creation of H-plus-electron luminescence centers and to the spontaneous H-I-centers conversion [ru

Detection of organic free radicals in irradiated pepper by electron spin resonance

International Nuclear Information System (INIS)

Ukai, Mitsuko; Shimoyama, Yuhei

2002-01-01

Using electron spin resonance (ESR) spectroscopy, we revealed various free radicals in a Japanese commercially available black pepper before and after γ-irradiation. The representative ESR spectrum of the pepper is composed of a sextet centered at g=2.0, a singlet at the same g-value and a singlet at g=4.0. The first one is attributable to a signal with hyperfine interactions of Mn 2+ ion (7.4 mT). The second one is due to an organic free radical. The third one may be originated from Fe 3+ ion of the non-hem Fe in proteins. A pair of signals appeared in the black pepper after γ-irradiation. The progressive saturation behavior reconfirmed the signal identification for the radicals in the black pepper. (author)

Changes in the Conformational State of Hemoglobin in Hemodialysed Patients with Chronic Renal Failure

Directory of Open Access Journals (Sweden)

Anna Pieniazek

2015-01-01

Full Text Available The aim of this study was to evaluate the properties of internal components of erythrocytes in chronic renal failure (CRF patients undergoing hemodialysis (HD in comparison to control subjects. For investigation of conformational state of hemoglobin and nonheme proteins (NHP the maleimide spin label (MSL in electron paramagnetic resonance (EPR was applied. The studies were performed using MSL in whole cells and hemolysate as well as proteins separated by ion exchange chromatography and checked by electrophoresis. Additionally the level of –SH groups in hemolysate and isolated internal proteins of CRF erythrocytes was determined using 4,4′-dithiodipyridine. All measurements were performed before and after hemodialysis. Oxidative stress accompanying CRF/hemodialysed patients caused a significant decrease in the mobility of internal components inside erythrocytes indicated by MSL (P < 0.02. The significant decrease in mobility of spin labeled HbA1c and HbA both before and after HD (P < 0.0002 as well as in nonheme proteins before hemodialysis (P < 0.05 versus control was indicated. Decrease in mobility of internal components of erythrocytes was accompanied by loss of thiols before and after hemodialysis versus control in NHP (P < 0.05, HbA1c (P < 0.0002, and HbA (P < 0.0005. These findings showed oxidative influence of hemodialysis on hemoglobins and internal nonheme proteins in erythrocytes of CRF patients.

Changes in the Conformational State of Hemoglobin in Hemodialysed Patients with Chronic Renal Failure

Science.gov (United States)

Pieniazek, Anna; Gwozdzinski, Krzysztof

2015-01-01

The aim of this study was to evaluate the properties of internal components of erythrocytes in chronic renal failure (CRF) patients undergoing hemodialysis (HD) in comparison to control subjects. For investigation of conformational state of hemoglobin and nonheme proteins (NHP) the maleimide spin label (MSL) in electron paramagnetic resonance (EPR) was applied. The studies were performed using MSL in whole cells and hemolysate as well as proteins separated by ion exchange chromatography and checked by electrophoresis. Additionally the level of –SH groups in hemolysate and isolated internal proteins of CRF erythrocytes was determined using 4,4′-dithiodipyridine. All measurements were performed before and after hemodialysis. Oxidative stress accompanying CRF/hemodialysed patients caused a significant decrease in the mobility of internal components inside erythrocytes indicated by MSL (P < 0.02). The significant decrease in mobility of spin labeled HbA1c and HbA both before and after HD (P < 0.0002) as well as in nonheme proteins before hemodialysis (P < 0.05) versus control was indicated. Decrease in mobility of internal components of erythrocytes was accompanied by loss of thiols before and after hemodialysis versus control in NHP (P < 0.05), HbA1c (P < 0.0002), and HbA (P < 0.0005). These findings showed oxidative influence of hemodialysis on hemoglobins and internal nonheme proteins in erythrocytes of CRF patients. PMID:25866600

The crystal structure of tryptophan hydroxylase with bound amino acid substrate

DEFF Research Database (Denmark)

Windahl, Michael Skovbo; Petersen, Charlotte Rode; Christensen, Hans Erik Mølager

2008-01-01

Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O2, and tetrahydrobiopterin (BH4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis of the neurotransmi......Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O2, and tetrahydrobiopterin (BH4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis...... acid hydroxylase with bound natural amino acid substrate. The iron coordination can be described as distorted trigonal bipyramidal coordination with His273, His278, and Glu318 (partially bidentate) and one imidazole as ligands. The tryptophan stacks against Pro269 with a distance of 3.9 Å between...

Mechanism of Oxidation of Ethane to Ethanol at Iron(IV)-Oxo Sites in Magnesium-Diluted Fe2(dobdc).

Science.gov (United States)

Verma, Pragya; Vogiatzis, Konstantinos D; Planas, Nora; Borycz, Joshua; Xiao, Dianne J; Long, Jeffrey R; Gagliardi, Laura; Truhlar, Donald G

2015-05-06

The catalytic properties of the metal-organic framework Fe2(dobdc), containing open Fe(II) sites, include hydroxylation of phenol by pure Fe2(dobdc) and hydroxylation of ethane by its magnesium-diluted analogue, Fe0.1Mg1.9(dobdc). In earlier work, the latter reaction was proposed to occur through a redox mechanism involving the generation of an iron(IV)-oxo species, which is an intermediate that is also observed or postulated (depending on the case) in some heme and nonheme enzymes and their model complexes. In the present work, we present a detailed mechanism by which the catalytic material, Fe0.1Mg1.9(dobdc), activates the strong C-H bonds of ethane. Kohn-Sham density functional and multireference wave function calculations have been performed to characterize the electronic structure of key species. We show that the catalytic nonheme-Fe hydroxylation of the strong C-H bond of ethane proceeds by a quintet single-state σ-attack pathway after the formation of highly reactive iron-oxo intermediate. The mechanistic pathway involves three key transition states, with the highest activation barrier for the transfer of oxygen from N2O to the Fe(II) center. The uncatalyzed reaction, where nitrous oxide directly oxidizes ethane to ethanol is found to have an activation barrier of 280 kJ/mol, in contrast to 82 kJ/mol for the slowest step in the iron(IV)-oxo catalytic mechanism. The energetics of the C-H bond activation steps of ethane and methane are also compared. Dehydrogenation and dissociation pathways that can compete with the formation of ethanol were shown to involve higher barriers than the hydroxylation pathway.

Diet and iron status of nonpregnant women in rural Central Mexico.

Science.gov (United States)

Backstrand, Jeffrey R; Allen, Lindsay H; Black, Anne K; de Mata, Margarita; Pelto, Gretel H

2002-07-01

Few studies have examined the relation of iron status to diet in populations from developing countries with high levels of iron deficiency and diets of poor quality. The objective was to identify nutrients, dietary constituents, and foods that are associated with better iron status in a rural Mexican population. A prospective cohort study was conducted in rural central Mexico. The subjects were 125 nonpregnant women aged 16-44 y. During the 12 mo before blood collection, food intakes were assessed repeatedly by a combination of dietary recalls, food weighing, and food diaries [mean (+/-SD) days of food intake data: 18.8 +/- 5.9 d]. Hemoglobin, hematocrit, and plasma ferritin were measured at the end of the study. Higher plasma ferritin concentrations were associated with greater intakes of nonheme iron and ascorbic acid after control for age, BMI, breast-feeding, season, and the time since the birth of the last child. Higher ascorbic acid intakes, but not higher intakes of heme and nonheme iron, predicted a lower risk of low hemoglobin and hematocrit values after control for the background variables. Consumption of the alcoholic beverage pulque predicted a lower risk of low ferritin and low hemoglobin values. Seasonal variation in ferritin, hemoglobin, and hematocrit values was observed. Better iron status was associated with greater intakes of foods containing nonheme iron and ascorbic acid. PULQUE:a beverage containing iron, ascorbic acid, and alcohol-may influence the iron status of women in rural central Mexico.

Overview of Minerals

Science.gov (United States)

... content of local soil) Required for the formation of thyroid hormones 150 micrograms 1,100 micrograms Iron As heme iron: Beef, poultry, fish, kidneys, and liver As nonheme iron: Soybean flour, beans, molasses, spinach, clams, and fortified grains and ...

Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non- Heme Iron(III) Complexes

NARCIS (Netherlands)

Jastrzebski, Robin; Quesne, Matthew G.; Weckhuysen, Bert M.; de Visser, Sam P.; Bruijnincx, Pieter C. A.

2014-01-01

Catechol intradiol dioxygenation is a unique reaction catalyzed by iron-dependent enzymes and nonheme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational

The Precarious Question of Black Cultural Centers Versus Multicultural Centers.

Science.gov (United States)

Princes, Carolyn D. W.

This paper discusses the role of black cultural centers on university campuses, focusing on whether black cultural centers or multicultural centers best meet the needs of an increasingly diverse student body and society. It examines the historical role of black cultural centers as vehicles to promote educational opportunity, student retention, and…

A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope.

Science.gov (United States)

Ahmad Fuzi, Salma F; Koller, Dagmar; Bruggraber, Sylvaine; Pereira, Dora Ia; Dainty, Jack R; Mushtaq, Sohail

2017-12-01

Background: Tea has been shown to be a potent inhibitor of nonheme iron absorption, but it remains unclear whether the timing of tea consumption relative to a meal influences iron bioavailability. Objective: The aim of the study was to investigate the effect of a 1-h time interval of tea consumption on nonheme iron absorption in an iron-containing meal in a cohort of iron-replete, nonanemic female subjects with the use of a stable isotope ( 57 Fe). Design: Twelve women (mean ± SD age: 24.8 ± 6.9 y) were administered a standardized porridge meal extrinsically labeled with 4 mg 57 Fe as FeSO 4 on 3 separate occasions, with a 14-d time interval between each test meal (TM). The TM was administered with water (TM-1), with tea administered simultaneously (TM-2), and with tea administered 1 h postmeal (TM-3). Fasted venous blood samples were collected for iron isotopic analysis and measurement of iron status biomarkers. Fractional iron absorption was estimated by the erythrocyte iron incorporation method. Results: Iron absorption was 5.7% ± 8.5% (TM-1), 3.6% ± 4.2% (TM-2), and 5.7% ± 5.4% (TM-3). Mean fractional iron absorption was found to be significantly higher (2.2%) when tea was administered 1 h postmeal (TM-3) than when tea was administered simultaneously with the meal (TM-2) ( P = 0.046). An ∼50% reduction in the inhibitory effect of tea (relative to water) was observed, from 37.2% (TM-2) to 18.1% (TM-3). Conclusions: This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency. This trial was registered at clinicaltrials.gov as NCT02365103. © 2017 American Society for

NRVS Studies of the Peroxide Shunt Intermediate in a Rieske Dioxygenase and Its Relation to the Native FesupII/supOinf2/infReaction

Czech Academy of Sciences Publication Activity Database

Sutherlin, K. D.; Rivard, B. S.; Böttger, L. H.; Liu, L. V.; Rogers, M. S.; Srnec, Martin; Park, K.; Yoda, Y.; Kitao, S.; Kobayashi, Y.; Saito, M.; Seto, M.; Hu, M.; Zhao, J.; Lipscomb, J. D.; Solomon, E. I.

2018-01-01

Roč. 140, č. 16 (2018), s. 5544-5559 ISSN 0002-7863 Institutional support: RVO:61388955 Keywords : NRVS studies * Rieske dioxygenase * mononuclear nonheme iron enzymes Subject RIV: CF - Physical ; The oretical Chemistry OBOR OECD: Physical chemistry Impact factor: 13.858, year: 2016

CD and MCD spectroscopic studies of the two Dps miniferritin proteins from Bacillus anthracis: role of O2 and H2O2 substrates in reactivity of the diiron catalytic centers.

Science.gov (United States)

Schwartz, Jennifer K; Liu, Xiaofeng S; Tosha, Takehiko; Diebold, Adrienne; Theil, Elizabeth C; Solomon, Edward I

2010-12-14

DNA protection during starvation (Dps) proteins are miniferritins found in bacteria and archaea that provide protection from uncontrolled Fe(II)/O radical chemistry; thus the catalytic sites are targets for antibiotics against pathogens, such as anthrax. Ferritin protein cages synthesize ferric oxymineral from Fe(II) and O(2)/H(2)O(2), which accumulates in the large central cavity; for Dps, H(2)O(2) is the more common Fe(II) oxidant contrasting with eukaryotic maxiferritins that often prefer dioxygen. To better understand the differences in the catalytic sites of maxi- versus miniferritins, we used a combination of NIR circular dichroism (CD), magnetic circular dichroism (MCD), and variable-temperature, variable-field MCD (VTVH MCD) to study Fe(II) binding to the catalytic sites of the two Bacillus anthracis miniferritins: one in which two Fe(II) react with O(2) exclusively (Dps1) and a second in which both O(2) or H(2)O(2) can react with two Fe(II) (Dps2). Both result in the formation of iron oxybiomineral. The data show a single 5- or 6-coordinate Fe(II) in the absence of oxidant; Fe(II) binding to Dps2 is 30× more stable than Dps1; and the lower limit of K(D) for binding a second Fe(II), in the absence of oxidant, is 2-3 orders of magnitude weaker than for the binding of the single Fe(II). The data fit an equilibrium model where binding of oxidant facilitates formation of the catalytic site, in sharp contrast to eukaryotic M-ferritins where the binuclear Fe(II) centers are preformed before binding of O(2). The two different binding sequences illustrate the mechanistic range possible for catalytic sites of the family of ferritins.

Quantum chemical study of hydroxylation of alkanes by hypofluorous acid

Czech Academy of Sciences Publication Activity Database

Ončák, Milan; Srnec, Martin; Zahradník, Rudolf

2008-01-01

Roč. 82, č. 4 (2008), s. 649-659 ISSN 0137-5083 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506 Keywords : electronic structure * nonheme iron * basis-set Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.518, year: 2008

Resistance to Fusarium oxysporum f. sp. gladioli in transgenic Gladiolus plants expressing either a bacterial chloroperoxidase or fungal chitinase genes

Science.gov (United States)

Three antifungal genes, a non-heme chloroperoxidase from Pseudomonas pyrrocinia, and an exochitinase and endochitinase from Fusarium venetanum under regulation by the CaMV 35S promoter, were used to transform Gladiolus for resistance to Fusarium oxysporum f. sp. gladioli. Gladiolus plants were conf...

An electron spin resonance study of γ-ray irradiated pepper

International Nuclear Information System (INIS)

Ukai, Mitsuko; Hamaya, Naruki; Ichii, Akane; Abe, Aika

2003-01-01

Using electron spin resonance (ESR) spectroscopy, we revealed four radical species in the irradiated pepper. The representative ESR spectrum of the pepper is composed of a sextet centered at g=2.0, a singlet at the same g-value, a singlet at g=4.0 and side peaks near g=2.0. The first one is attributable to a signal with hyperfine (hf) interactions of Mn 2+ ion (hf constant=7.4 mT). The second one is due to an organic free radical that may be induced by the (γ-ray irradiation. The third one may be originated from Fe 3+ ion in the non-hem proteins. Those three signals were found in the pepper sample before irradiation. The fourth signals were found at the symmetric position of the organic free radical, i.e., the second signal. The progressive saturation method of the ESR microwave power indicated quite different relaxation behaviors of those radicals. The method reflects four independent radical species in the irradiated pepper. Relaxation time for the singlet signal centered at g=2.0 revealed that the signal is due to the typical organic free radical. (author)

Stephenson Cancer Center

Science.gov (United States)

Stephenson Cancer Center at the University of Oklahoma in Oklahoma City is an NCI-designated cancer center at the forefront of NCI-supported cancer research. Learn more about the Stephenson Cancer Center's mission.

Engineer Research and Development Center's Materials Testing Center (MTC)

Data.gov (United States)

Federal Laboratory Consortium — The Engineer Research and Development Center's Materials Testing Center (MTC) is committed to quality testing and inspection services that are delivered on time and...

Perilaku Kreatif Pekerja Call Center: Peran Komunikasi dan Dukungan Training Center

Directory of Open Access Journals (Sweden)

Nugroho J. Setiadi

2013-11-01

Full Text Available Call center business in Indonesia is growing rapidly worldwide. This condition has had repercussions for a growing number of call center workers needed. They are forced to be more creative in performing their duties. This study aims to determine the role of communication and training center in supporting the creative performance of workers in call centers. The survey was conducted by distributing questionnaires to 100 respondents (employees of the 3 major companies in the field of telecommunication services in Indonesia. Regression analysis was used to analyze the data to examine the role of communication and training support center on creative performance. The results indicated that communication and training support center significantly influence the creative behavior in call center workers. Communication quality shown in the telecommunication service provider companies, such as the media quality, simplicity of information, dissemination of information, loads of information, and accuracy of messages, has shown good quality. In addition, the training program has shown its support for call center workers in the form of program effectiveness through research and data collection, determining the materials, training methods, choosing a coach, preparing facilities, selecting and implementing the program.

Trauma Center Staffing, Infrastructure, and Patient Characteristics that Influence Trauma Center Need

Directory of Open Access Journals (Sweden)

Faul, Mark

2014-11-01

Full Text Available Introduction: The most effective use of trauma center resources helps reduce morbidity and mortality, while saving costs. Identifying critical infrastructure characteristics, patient characteristics and staffing components of a trauma center associated with the proportion of patients needing major trauma care will help planners create better systems for patient care.   Methods: We used the 2009 National Trauma Data Bank-Research Dataset to determine the proportion of critically injured patients requiring the resources of a trauma center within each Level I-IV trauma center (n=443. The outcome variable was defined as the portion of treated patients who were critically injured. We defined the need for critical trauma resources and interventions (“trauma center need” as death prior to hospital discharge, admission to the intensive care unit, or admission to the operating room from the emergency department as a result of acute traumatic injury. Generalized Linear Modeling (GLM was used to determine how hospital infrastructure, staffing Levels, and patient characteristics contributed to trauma center need.     Results: Nonprofit Level I and II trauma centers were significantly associated with higher levels of trauma center need. Trauma centers that had a higher percentage of transferred patients or a lower percentage of insured patients were associated with a higher proportion of trauma center need.  Hospital infrastructure characteristics, such as bed capacity and intensive care unit capacity, were not associated with trauma center need. A GLM for Level III and IV trauma centers showed that the number of trauma surgeons on staff was associated with trauma center need. Conclusion: Because the proportion of trauma center need is predominantly influenced by hospital type, transfer frequency, and insurance status, it is important for administrators to consider patient population characteristics of the catchment area when planning the

Radioisotope investigation of iron absorption in humans. Part of a WHO/IAEA coordinated programme on iron nutrition

International Nuclear Information System (INIS)

Bothwell, T.H.

1975-08-01

The gastrointestinal absorption of iron was investigated in a number of multiparous women living under low socio-economic conditions which are known to lead commonly to iron deficiency. The percentage absorption was deduced by comparing the concentration of 55 Fe and/or 59 Fe in blood with the activity of the corresponding isotope(s) administered orally about two weeks earlier. It was confirmed or established that: (1) food or supplemental iron, if available at all, tends to be absorbed from the intestines as if present there in one of two alternative pools: heme and non-heme, (2) vitamin C substantially increases absorption of food or supplemental non-heme iron, (3) it is technically possible to use common salt or sugar as a carrier for supplemental iron and vitamin C, but practical difficulties of using such systems in a public health prophylactic programme are severe, and (4) tea, presumably because of its tannin content, inhibits absorption of accompanying iron

User-centered design

International Nuclear Information System (INIS)

Baik, Joo Hyun; Kim, Hyeong Heon

2008-01-01

The simplification philosophy, as an example, that both of EPRI-URD and EUR emphasize is treated mostly for the cost reduction of the nuclear power plants, but not for the simplification of the structure of user's tasks, which is one of the principles of user-centered design. A user-centered design is a philosophy based on the needs and interests of the user, with an emphasis on making products usable and understandable. However, the nuclear power plants offered these days by which the predominant reactor vendors are hardly user-centered but still designer-centered or technology-centered in viewpoint of fulfilling user requirements. The main goal of user-centered design is that user requirements are elicited correctly, reflected properly into the system requirements, and verified thoroughly by the tests. Starting from the user requirements throughout to the final test, each requirement should be traceable. That's why requirement traceability is a key to the user-centered design, and main theme of a requirement management program, which is suggested to be added into EPRI-URD and EUR in the section of Design Process. (author)

Aerial view of the Kennedy Space Center Visitor Center

Science.gov (United States)

1998-01-01

The Kennedy Space Center Visitor Center, shown in this aerial view looking south, sprawls across 70 acres on Florida's Space Coast , and is located off State Road 405, NASA Parkway, six miles inside the Space Center entrance. SR 405 can be seen at the bottom of the photo. Just above the roadway, from left can be seen the Shuttle/Gantry mockup; the Post Show Dome; the Astronaut Memorial; and to the far right, the Center for Space Education. Behind the Memorial are a cluster of buildings that include the Theater Complex, Cafeteria, Space Flight Exhibit Building, Souvenir Sales Building, Spaceport Central, and Ticket Pavilion. At the upper right are various rockets that have played a significant role in the growth of the space program.

Wound care centers

Science.gov (United States)

Pressure ulcer - wound care center; Decubitus ulcer - wound care center; Diabetic ulcer - wound care center; Surgical wound - wound ... Common types of non-healing wounds include: Pressure sores Surgical ... flow, or swollen legs Certain wounds may not heal well due to: ...

Reactions of diiron m-aminocarbyne complexes containing nitrile ligands

Directory of Open Access Journals (Sweden)

Busetto Luigi

2003-01-01

Full Text Available The acetonitrile ligand in the mu-aminocarbyne complexes [Fe2{mu-CN(MeR}(mu-CO(CO(NCMe(Cp2][SO 3CF3] (R = Me, 2a, CH2Ph, 2b, Xyl, 2c (Xyl = 2,6-Me2C6H3 is readily displaced by halides and cyanide anions affording the corresponding neutral species [Fe2{mu-CN(MeR}(mu-CO(CO(X(Cp2 ] (X = Br, I, CN. Complexes 2 undergo deprotonation and rearrangement of the coordinated MeCN upon treatment with organolithium reagents. Trimethylacetonitrile, that does not contain acidic alpha hydrogens has been used in place of MeCN to form the complexes [Fe2{mu-CN(MeR}(mu-CO(CO(NCCMe3 (Cp2][SO3CF3] (7a-c. Attempts to replace the nitrile ligand in 3 with carbon nucleophiles (by reaction with RLi failed, resulting in decomposition products. However the reaction of 7c with LiCºCTol (Tol = C6H4Me, followed by treatment with HSO3CF3, yielded the imino complex [Fe2{mu-CN(MeXyl}(mu-CO(CO {N(HC(CºCC6H4Me-4CMe3}(Cp 2][SO3CF3 ] (8, obtained via acetilyde addition at the coordinated NCCMe3.

Data Center Tasking.

Science.gov (United States)

Temares, M. Lewis; Lutheran, Joseph A.

Operations tasking for data center management is discussed. The original and revised organizational structures of the data center at the University of Miami are also described. The organizational strategy addresses the functions that should be performed by the data center, anticipates the specialized skills required, and addresses personnel…

Usage Center

DEFF Research Database (Denmark)

Kleinaltenkamp, Michael; Plewa, Carolin; Gudergan, Siegfried

2017-01-01

Purpose: The purpose of this paper is to advance extant theorizing around resourceintegration by conceptualizing and delineating the notion of a usage center. Ausage center consists of a combination of interdependent actors that draw onresources across their individual usage processes to create v...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Catechol 1,2-dioxygenase (CTD) and protocatechuate 3,4-dioxygenase (PCD) are bacterial non-heme iron enzymes, which catalyse the oxidative cleavage of catechols to cis, cis-muconic acids with the incorporation of molecular oxygen via a mechanism involving a high-spin ferric centre. The iron(III) complexes of tripodal ...

Serum hepcidin is significantly associated with iron absorption from food and supplemental sources in healthy young woman

Science.gov (United States)

Hepcidin is a key regulator of iron homeostasis, but to date no studies have examined the effect of hepcidin on iron absorption in humans. Our objective was to assess relations between both serum hepcidin and serum prohepcidin with nonheme-iron absorption in the presence and absence of food with the...

ENERGY RESOURCES CENTER

Energy Technology Data Exchange (ETDEWEB)

Sternberg, Virginia

1979-11-01

First I will give a short history of this Center which has had three names and three moves (and one more in the offing) in three years. Then I will tell you about the accomplishments made in the past year. And last, I will discuss what has been learned and what is planned for the future. The Energy and Environment Information Center (EEIC), as it was first known, was organized in August 1975 in San Francisco as a cooperative venture by the Federal Energy Administration (FEA), Energy Research and Development Administration (ERDA) and the Environmental Protection Agency (EPA). These three agencies planned this effort to assist the public in obtaining information about energy and the environmental aspects of energy. The Public Affairs Offices of FEA, ERDA and EPA initiated the idea of the Center. One member from each agency worked at the Center, with assistance from the Lawrence Berkeley Laboratory Information Research Group (LBL IRG) and with on-site help from the EPA Library. The Center was set up in a corner of the EPA Library. FEA and ERDA each contributed one staff member on a rotating basis to cover the daily operation of the Center and money for books and periodicals. EPA contributed space, staff time for ordering, processing and indexing publications, and additional money for acquisitions. The LBL Information Research Group received funds from ERDA on a 189 FY 1976 research project to assist in the development of the Center as a model for future energy centers.

The Comparison between Teacher Centered and Student Centered Educational Methods

Directory of Open Access Journals (Sweden)

M Anvar

2009-02-01

Full Text Available Background and Purpose: Various approaches to learning are suggested & practiced. The traditional medical education were more teacher centered oriented . In this method the students’ involvement in the process of learning is not remarkable, but the new approach to medical education supports the students involvement. This study evaluated the various method of lecturing considering students involvements.Methods: One hundred two first year medical and nursing students involved in this study and their opinion about these two methods of learning were obtained by filling of a questionnaire. The subject of the lectures was “general psychology” which was carried out 50% by the students and 50% by the teacher. The statistical analysis was carried out by SPSS program.Results: Considering students opinion in student-centered method the various aspect of learning such as mutual understanding, use of textbooks and references were significantly increased , whereasother aspects of learning such as self esteem, study time, innovation, and study attitude though were improved, but were not significant as compared with teacher centered method. In teacher-centeredmethod the understanding of the subjects was significantly increased .Other aspects of learning such as motivation and concentration were improved but not significantly as compared with studentcentered method.Conclusion: As the result showed student centered method was favored in several aspects of learning while in teacher centered method only understanding of the subject was better . Careful choice of teaching method to provide a comprehensive learning experience should take into account these differences.Key words: TEACHER CENTERED, STUDENT CENTERED, LEARNING

On The Center Sets and Center Numbers of Some Graph Classes

OpenAIRE

R, Ram Kumar.; Balakrishnan, Kannan; Changat, Manoj; Sreekumar, A.; Narasimha-Shenoi, Prasanth G.

2013-01-01

For a set $S$ of vertices and the vertex $v$ in a connected graph $G$, $\\displaystyle\\max_{x \\in S}d(x,v)$ is called the $S$-eccentricity of $v$ in $G$. The set of vertices with minimum $S$-eccentricity is called the $S$-center of $G$. Any set $A$ of vertices of $G$ such that $A$ is an $S$-center for some set $S$ of vertices of $G$ is called a center set. We identify the center sets of certain classes of graphs namely, Block graphs, $K_{m,n}$, $K_n-e$, wheel graphs, odd cycles and symmetric e...

How oxygen attacks [FeFe] hydrogenases from photosynthetic organisms

Science.gov (United States)

Stripp, Sven T.; Goldet, Gabrielle; Brandmayr, Caterina; Sanganas, Oliver; Vincent, Kylie A.; Haumann, Michael; Armstrong, Fraser A.; Happe, Thomas

2009-01-01

Green algae such as Chlamydomonas reinhardtii synthesize an [FeFe] hydrogenase that is highly active in hydrogen evolution. However, the extreme sensitivity of [FeFe] hydrogenases to oxygen presents a major challenge for exploiting these organisms to achieve sustainable photosynthetic hydrogen production. In this study, the mechanism of oxygen inactivation of the [FeFe] hydrogenase CrHydA1 from C. reinhardtii has been investigated. X-ray absorption spectroscopy shows that reaction with oxygen results in destruction of the [4Fe-4S] domain of the active site H-cluster while leaving the di-iron domain (2FeH) essentially intact. By protein film electrochemistry we were able to determine the order of events leading up to this destruction. Carbon monoxide, a competitive inhibitor of CrHydA1 which binds to an Fe atom of the 2FeH domain and is otherwise not known to attack FeS clusters in proteins, reacts nearly two orders of magnitude faster than oxygen and protects the enzyme against oxygen damage. These results therefore show that destruction of the [4Fe-4S] cluster is initiated by binding and reduction of oxygen at the di-iron domain—a key step that is blocked by carbon monoxide. The relatively slow attack by oxygen compared to carbon monoxide suggests that a very high level of discrimination can be achieved by subtle factors such as electronic effects (specific orbital overlap requirements) and steric constraints at the active site. PMID:19805068

Iron(III) complexes of certain tetradentate phenolate ligands as ...

Indian Academy of Sciences (India)

non-heme iron enzymes, which catalyse the oxidative cleavage of catechols to cis, cis-muconic acids with the incorporation of ... nature of heterocyclic rings of the ligands and the methyl substituents on them regulate the electronic spectral features .... and simple substitution reactions.19,21 The complexes of [H2(L5)] and ...

Center-Specific Factors Associated with Peritonitis Risk-A Multi-Center Registry Analysis.

Science.gov (United States)

Nadeau-Fredette, Annie-Claire; Johnson, David W; Hawley, Carmel M; Pascoe, Elaine M; Cho, Yeoungjee; Clayton, Philip A; Borlace, Monique; Badve, Sunil V; Sud, Kamal; Boudville, Neil; McDonald, Stephen P

♦ Previous studies have reported significant variation in peritonitis rates across dialysis centers. Limited evidence is available to explain this variability. The aim of this study was to assess center-level predictors of peritonitis and their relationship with peritonitis rate variations. ♦ All incident peritoneal dialysis (PD) patients treated in Australia between October 2003 and December 2013 were included. Data were accessed through the Australia and New Zealand Dialysis and Transplant Registry. The primary outcome was peritonitis rate, evaluated in a mixed effects negative binomial regression model. Peritonitis-free survival was assessed as a secondary outcome in a Cox proportional hazards model. ♦ Overall, 8,711 incident PD patients from 51 dialysis centers were included in the study. Center-level predictors of lower peritonitis rates included smaller center size, high proportion of PD, low peritoneal equilibration test use at PD start, and low proportion of hospitalization for peritonitis. In contrast, a low proportion of automated PD exposure, high icodextrin exposure and low or high use of antifungal prophylaxis at the time of peritonitis were associated with a higher peritonitis rate. Similar results were obtained for peritonitis-free survival. Overall, accounting for center-level characteristics appreciably decreased peritonitis variability among dialysis centers (p = 0.02). ♦ This study identified specific center-level characteristics associated with the variation in peritonitis risk. Whether these factors are directly related to peritonitis risk or surrogate markers for other center characteristics is uncertain and should be validated in further studies. Copyright © 2016 International Society for Peritoneal Dialysis.

Carbon Monoxide Information Center

Medline Plus

Full Text Available ... Education Safety Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as CO, is called the " ...

Womens Business Center

Data.gov (United States)

Small Business Administration — Women's Business Centers (WBCs) represent a national network of nearly 100 educational centers throughout the United States and its territories, which are designed...

Self-Access Centers: Maximizing Learners’ Access to Center Resources

Directory of Open Access Journals (Sweden)

Mark W. Tanner

2010-09-01

Full Text Available Originally published in TESL-EJ March 2009, Volume 12, Number 4 (http://tesl-ej.org/ej48/a2.html. Reprinted with permission from the authors.Although some students have discovered how to use self-access centers effectively, the majority appear to be unaware of available resources. A website and database of materials were created to help students locate materials and use the Self-Access Study Center (SASC at Brigham Young University’s English Language Center (ELC more effectively. Students took two surveys regarding their use of the SASC. The first survey was given before the website and database were made available. A second survey was administered 12 weeks after students had been introduced to the resource. An analysis of the data shows that students tend to use SASC resources more autonomously as a result of having a web-based database. The survey results suggest that SAC managers can encourage more autonomous use of center materials by provided a website and database to help students find appropriate materials to use to learn English.

78 FR 14549 - National Contact Center; Information Collection; National Contact Center Customer Evaluation Survey

Science.gov (United States)

2013-03-06

...] National Contact Center; Information Collection; National Contact Center Customer Evaluation Survey AGENCY... National Contact Center customer evaluation surveys. In this request, the previously approved surveys have... several months. These temporary surveys will allow the National Contact Center to compare its customer...

MARYLAND ROBOTICS CENTER

Data.gov (United States)

Federal Laboratory Consortium — The Maryland Robotics Center is an interdisciplinary research center housed in the Institute for Systems Research (link is external)within the A. James Clark School...

NIH Clinical Centers

Data.gov (United States)

Federal Laboratory Consortium — The NIH Clinical Center consists of two main facilities: The Mark O. Hatfield Clinical Research Center, which opened in 2005, houses inpatient units, day hospitals,...

Hydrologic Engineering Center

Data.gov (United States)

Federal Laboratory Consortium — The Hydrologic Engineering Center (HEC), an organization within the Institute for Water Resources, is the designated Center of Expertise for the U.S. Army Corps of...

Call Center Capacity Planning

DEFF Research Database (Denmark)

Nielsen, Thomas Bang

in order to relate the results to the service levels used in call centers. Furthermore, the generic nature of the approximation is demonstrated by applying it to a system incorporating a dynamic priority scheme. In the last paper Optimization of overflow policies in call centers, overflows between agent......The main topics of the thesis are theoretical and applied queueing theory within a call center setting. Call centers have in recent years become the main means of communication between customers and companies, and between citizens and public institutions. The extensively computerized infrastructure...... in modern call centers allows for a high level of customization, but also induces complicated operational processes. The size of the industry together with the complex and labor intensive nature of large call centers motivates the research carried out to understand the underlying processes. The customizable...

Carbon Monoxide Information Center

Medline Plus

Full Text Available ... Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, ... Install one and check its batteries regularly. View Information About CO Alarms Other CO Topics Safety Tips ...

Funding Opportunity: Genomic Data Centers

Science.gov (United States)

Funding Opportunity CCG, Funding Opportunity Center for Cancer Genomics, CCG, Center for Cancer Genomics, CCG RFA, Center for cancer genomics rfa, genomic data analysis network, genomic data analysis network centers,

Design, Preparation, and Characterization of Zn and Cu Metallopeptides Based On Tetradentate Aminopyridine Ligands Showing Enhanced DNA Cleavage Activity

Czech Academy of Sciences Publication Activity Database

Soler, M.; Figueras, E.; Serrano-Plana, J.; Gonzalez-Bartulos, M.; Massaguer, A.; Company, A.; Martinez, M.A.; Malina, Jaroslav; Brabec, Viktor; Feliu, L.; Planas, M.; Ribas, X.; Costas, M.

2015-01-01

Roč. 54, č. 22 (2015), s. 10542-10558 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GAP205/11/0856; GA ČR(CZ) GA14-21053S Institutional support: RVO:68081707 Keywords : SOLID-PHASE SYNTHESIS * NONHEME IRON CATALYSTS * METAL-COMPLEXES Subject RIV: BO - Biophysics Impact factor: 4.820, year: 2015

Structural and Spectroscopic Properties of the Peroxodiferric Intermediate of Ricinus communis Soluble Delta(9) Desaturase

Czech Academy of Sciences Publication Activity Database

Srnec, Martin; Rokob, Tibor András; Schwartz, J. K.; Kwak, Y.; Rulíšek, Lubomír; Solomon, E. I.

2012-01-01

Roč. 51, č. 5 (2012), s. 2806-2820 ISSN 0020-1669 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : diferrous non-heme iron enzyme * QM/MM calculations * delta-9 * desaturase * reaction mechanism Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.593, year: 2012

Day Care Centers

Data.gov (United States)

Department of Homeland Security — This database contains locations of day care centers for 50 states and Washington D.C. and Puerto Rico. The dataset only includes center based day care locations...

Evaluate Data Center Network Performance

DEFF Research Database (Denmark)

Pilimon, Artur

through a data center network, which is usually built with layer 2 switches and layer 3 routers. The topology of the data center network is crucial for latency in the data communication to and from the data center and between servers in the data center. Tests can be conducted to measure latency and other...... Engineering, scientists evaluate data center network topologies with an SDN-based (Software-Defined Networking) control framework measuring network performance – primarily latency. This can be used to plan data center scaling by testing how a new topology will function before changes are made. Data center...... performance parameters for different data center network topologies. It is however important that tests can be repeated and reproduced to have comparable information from the tests. There are, of course, many topologies that can be used for data center networks. At DTU Fotonik, Department of Photonics...

Center for Adaptive Optics | Center

Science.gov (United States)

Astronomy, UCSC's CfAO and ISEE, and Maui Community College, runs education and internship programs in / Jacobs Retina Center Department of Psychology University of California, San Francisco Department of University School of Optometry Maui Community College Maui Community College Space Grant Program Montana

Energy efficient data centers

Energy Technology Data Exchange (ETDEWEB)

Tschudi, William; Xu, Tengfang; Sartor, Dale; Koomey, Jon; Nordman, Bruce; Sezgen, Osman

2004-03-30

Data Center facilities, prevalent in many industries and institutions are essential to California's economy. Energy intensive data centers are crucial to California's industries, and many other institutions (such as universities) in the state, and they play an important role in the constantly evolving communications industry. To better understand the impact of the energy requirements and energy efficiency improvement potential in these facilities, the California Energy Commission's PIER Industrial Program initiated this project with two primary focus areas: First, to characterize current data center electricity use; and secondly, to develop a research ''roadmap'' defining and prioritizing possible future public interest research and deployment efforts that would improve energy efficiency. Although there are many opinions concerning the energy intensity of data centers and the aggregate effect on California's electrical power systems, there is very little publicly available information. Through this project, actual energy consumption at its end use was measured in a number of data centers. This benchmark data was documented in case study reports, along with site-specific energy efficiency recommendations. Additionally, other data center energy benchmarks were obtained through synergistic projects, prior PG&E studies, and industry contacts. In total, energy benchmarks for sixteen data centers were obtained. For this project, a broad definition of ''data center'' was adopted which included internet hosting, corporate, institutional, governmental, educational and other miscellaneous data centers. Typically these facilities require specialized infrastructure to provide high quality power and cooling for IT equipment. All of these data center types were considered in the development of an estimate of the total power consumption in California. Finally, a research ''roadmap'' was developed

Antioxidant Activities of Achyranthes japonica Nakai Extract and Its Application to the Pork Sausages

Science.gov (United States)

Park, J. H.; Kang, S. N.; Shin, D.; Hur, I. C.; Kim, I. S.; Jin, S. K.

2013-01-01

Influence of Achyranthes japonica Nakai Extract (AJNE) on properties of pork sausages were studied in the present investigation. AJNE was added to sausages alone or in combination with ascorbic acid to obtain a comparative analysis on properties of control and ascorbic acid added-sausages. Results showed that addition of 0.05% AJNE led to a decrease in color L* and whiteness (W), and an increase in color b* of pork sausage samples (psausages containing AJNE was not significantly different, ascorbic acid added-sausages were highest amongst other treatments (pSausages containing AJNE had lower non-heme iron values and peroxide value (POV) than control sausages (psausages (psausages (psausages. Free radical scavenging analysis showed that AJNE did not affect 1,1-diphenyl -2-picrylhydrazyl (DPPH) activity of sausages, whereas ascorbic acid added-sausages showed relatively higher activity among the samples (psausages. In sensory evaluation, AJNE treatment had significant effects on color (psausages, and appears to be particularly effective in inducing changes in non-heme iron concentration, POV value and nitrosomyglobin content. PMID:25049789

Handbook on data centers

CERN Document Server

Khan, Samee Ullah

2015-01-01

This handbook offers a comprehensive review of the state-of-the-art research achievements in the field of data centers. Contributions from international, leading researchers and scholars offer topics in cloud computing, virtualization in data centers, energy efficient data centers, and next generation data center architecture.  It also comprises current research trends in emerging areas, such as data security, data protection management, and network resource management in data centers. Specific attention is devoted to industry needs associated with the challenges faced by data centers, such as various power, cooling, floor space, and associated environmental health and safety issues, while still working to support growth without disrupting quality of service. The contributions cut across various IT data technology domains as a single source to discuss the interdependencies that need to be supported to enable a virtualized, next-generation, energy efficient, economical, and environmentally friendly data cente...

Actions Needed to Ensure Scientific and Technical Information is Adequately Reviewed at Goddard Space Flight Center, Johnson Space Center, Langley Research Center, and Marshall Space Flight Center

Science.gov (United States)

2008-01-01

This audit was initiated in response to a hotline complaint regarding the review, approval, and release of scientific and technical information (STI) at Johnson Space Center. The complainant alleged that Johnson personnel conducting export control reviews of STI were not fully qualified to conduct those reviews and that the reviews often did not occur until after the STI had been publicly released. NASA guidance requires that STI, defined as the results of basic and applied scientific, technical, and related engineering research and development, undergo certain reviews prior to being released outside of NASA or to audiences that include foreign nationals. The process includes technical, national security, export control, copyright, and trade secret (e.g., proprietary data) reviews. The review process was designed to preclude the inappropriate dissemination of sensitive information while ensuring that NASA complies with a requirement of the National Aeronautics and Space Act of 1958 (the Space Act)1 to provide for the widest practicable and appropriate dissemination of information resulting from NASA research activities. We focused our audit on evaluating the STI review process: specifically, determining whether the roles and responsibilities for the review, approval, and release of STI were adequately defined and documented in NASA and Center-level guidance and whether that guidance was effectively implemented at Goddard Space Flight Center, Johnson Space Center, Langley Research Center, and Marshall Space Flight Center. Johnson was included in the review because it was the source of the initial complaint, and Goddard, Langley, and Marshall were included because those Centers consistently produce significant amounts of STI.

Poison Control Centers

Science.gov (United States)

... 1222 immediately. Name State American Association of Poison Control Centers Address AAPCC Central Office NOT A POISON ... not for emergency use. Arkansas ASPCA Animal Poison Control Center Address 1717 S. Philo Road, Suite 36 Urbana, ...

Relative Lyapunov Center Bifurcations

DEFF Research Database (Denmark)

Wulff, Claudia; Schilder, Frank

2014-01-01

Relative equilibria (REs) and relative periodic orbits (RPOs) are ubiquitous in symmetric Hamiltonian systems and occur, for example, in celestial mechanics, molecular dynamics, and rigid body motion. REs are equilibria, and RPOs are periodic orbits of the symmetry reduced system. Relative Lyapunov...... center bifurcations are bifurcations of RPOs from REs corresponding to Lyapunov center bifurcations of the symmetry reduced dynamics. In this paper we first prove a relative Lyapunov center theorem by combining recent results on the persistence of RPOs in Hamiltonian systems with a symmetric Lyapunov...... center theorem of Montaldi, Roberts, and Stewart. We then develop numerical methods for the detection of relative Lyapunov center bifurcations along branches of RPOs and for their computation. We apply our methods to Lagrangian REs of the N-body problem....

Center of buoyancy definition

International Nuclear Information System (INIS)

Sandberg, V.

1988-12-01

The center of buoyancy of an arbitrary shaped body is defined in analogy to the center of gravity. The definitions of the buoyant force and center of buoyancy in terms of integrals over the area of the body are converted to volume integrals and shown to have simple intuitive interpretations

NREL's Education Center Programs | NREL

Science.gov (United States)

NREL's Education Center Programs NREL's Education Center Programs There are a variety of educational programs offered through NREL's education center to inspire our community to explore the science neighbors, campus and trail maps, and more. A photo of the NREL Education Center exterior. Programs for

Alternative Fuels Data Center: Biodiesel

Science.gov (United States)

Biodiesel Printable Version Share this resource Send a link to Alternative Fuels Data Center : Biodiesel to someone by E-mail Share Alternative Fuels Data Center: Biodiesel on Facebook Tweet about Alternative Fuels Data Center: Biodiesel on Twitter Bookmark Alternative Fuels Data Center: Biodiesel on

Accredited Birth Centers

Science.gov (United States)

... Danbury, CT 06810 203-748-6000 Accredited Since March 1998 Corvallis Birth & Women's Health Center Accredited 2314 NW Kings Blvd, Suite ... Washington, DC 20002 202-398-5520 Accredited Since March 2001 Flagstaff Birth and Women's Center Accredited 401 West Aspen Avenue Flagstaff, AZ ...

78 FR 30303 - National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation...

Science.gov (United States)

2013-05-22

...] National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation Survey... regarding the National Contact Center customer evaluation surveys. In this request, the previously approved... customer service levels to those of private industry contact centers. A notice was published in the Federal...

"Infotonics Technology Center"

Energy Technology Data Exchange (ETDEWEB)

Fritzemeier, L. [Infotonics Technology Center Inc., Canandaigua, NY (United States); Boysel, M. B. [Infotonics Technology Center Inc., Canandaigua, NY (United States); Smith, D. R. [Infotonics Technology Center Inc., Canandaigua, NY (United States)

2004-09-30

During this grant period July 15, 2002 thru September 30, 2004, the Infotonics Technology Center developed the critical infrastructure and technical expertise necessary to accelerate the development of sensors, alternative lighting and power sources, and other specific subtopics of interest to Department of Energy. Infotonics fosters collaboration among industry, universities and government and operates as a national center of excellence to drive photonics and microsystems development and commercialization. A main goal of the Center is to establish a unique, world-class research and development facility. A state-of-the-art microsystems prototype and pilot fabrication facility was established to enable rapid commercialization of new products of particular interest to DOE. The Center has three primary areas of photonics and microsystems competency: device research and engineering, packaging and assembly, and prototype and pilot-scale fabrication. Center activities focused on next generation optical communication networks, advanced imaging and information sensors and systems, micro-fluidic systems, assembly and packaging technologies, and biochemical sensors. With targeted research programs guided by the wealth of expertise of Infotonics business and scientific staff, the fabrication and packaging facility supports and accelerates innovative technology development of special interest to DOE in support of its mission and strategic defense, energy, and science goals.

Launch Vehicle Control Center Architectures

Science.gov (United States)

Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Williams, Randall; McLaughlin, Tom

2014-01-01

This analysis is a survey of control center architectures of the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures have similarities in basic structure, and differences in functional distribution of responsibilities for the phases of operations: (a) Launch vehicles in the international community vary greatly in configuration and process; (b) Each launch site has a unique processing flow based on the specific configurations; (c) Launch and flight operations are managed through a set of control centers associated with each launch site, however the flight operations may be a different control center than the launch center; and (d) The engineering support centers are primarily located at the design center with a small engineering support team at the launch site.

The role of metals in production and scavenging of reactive oxygen species in photosystem II.

Science.gov (United States)

Pospíšil, Pavel

2014-07-01

Metal ions play a crucial role in enzymatic reactions in all photosynthetic organisms such as cyanobacteria, algae and plants. It well known that metal ions maintain the binding of substrate in the active site of the metalloenzymes and control the redox activity of the metalloenzyme in the enzymatic reaction. A large pigment-protein complex, PSII, known to serve as a water-plastoquinone oxidoreductase, contains three metal centers comprising non-heme iron, heme iron of Cyt b559 and the water-splitting manganese complex. Metal ions bound to PSII proteins maintain the electron transport from water to plastoquinone and regulate the pro-oxidant and antioxidant activity in PSII. In this review, attention is focused on the role of PSII metal centers in (i) the formation of superoxide anion and hydroxyl radicals by sequential one-electron reduction of molecular oxygen and the formation of hydrogen peroxide by incomplete two-electron oxidation of water; and (ii) the elimination of superoxide anion radical by one-electron oxidation and reduction (superoxide dismutase activity) and of hydrogen peroxide by two-electron oxidation and reduction (catalase activity). The balance between the formation and elimination of reactive oxygen species by PSII metal centers is discussed as an important aspect in the prevention of photo-oxidative damage of PSII proteins and lipids. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Nuclear Reaction Data Centers

International Nuclear Information System (INIS)

McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

1988-01-01

The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

A novel patient-centered "intention-to-treat" metric of U.S. lung transplant center performance.

Science.gov (United States)

Maldonado, Dawn A; RoyChoudhury, Arindam; Lederer, David J

2018-01-01

Despite the importance of pretransplantation outcomes, 1-year posttransplantation survival is typically considered the primary metric of lung transplant center performance in the United States. We designed a novel lung transplant center performance metric that incorporates both pre- and posttransplantation survival time. We performed an ecologic study of 12 187 lung transplant candidates listed at 56 U.S. lung transplant centers between 2006 and 2012. We calculated an "intention-to-treat" survival (ITTS) metric as the percentage of waiting list candidates surviving at least 1 year after transplantation. The median center-level 1-year posttransplantation survival rate was 84.1%, and the median center-level ITTS was 66.9% (mean absolute difference 19.6%, 95% limits of agreement 4.3 to 35.1%). All but 10 centers had ITTS values that were significantly lower than 1-year posttransplantation survival rates. Observed ITTS was significantly lower than expected ITTS for 7 centers. These data show that one third of lung transplant candidates do not survive 1 year after transplantation, and that 12% of centers have lower than expected ITTS. An "intention-to-treat" survival metric may provide a more realistic expectation of patient outcomes at transplant centers and may be of value to transplant centers and policymakers. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

The Lathrop Wells volcanic center

International Nuclear Information System (INIS)

Crowe, B.; Morley, R.

1992-01-01

The Lathrop Wells volcanic center is located 20 km south of the potential Yucca Mountain site, at the south end of the Yucca Mountain range. This paper discusses a detailed Study Plan which was prepared describing planned geochronology and field studies to assess the chronology of the Lathrop Wells volcanic center and other Quaternary volcanic centers in the region. A paper was published discussing the geomorphic and soil evidence for a late Pleistocene or Holoceno age for the main cone of the center. The purpose of this paper was to expose the ideas concerning the age of the Lathrop Wells center to scientific scrutiny. Additionally, field evidence was described suggesting the Lathrop Wells center may have formed from multiple eruptive events with significant intervals of no activity between events. This interpretation breaks with established convention in the volcanological literature that small volume basalt centers are monogenetic

Family Care Map: Sustaining family-centered care in Polytrauma Rehabilitation Centers

Science.gov (United States)

Ford, James H.; Wise, Meg; Krahn, Dean; Oliver, Karen Anderson; Hall, Carmen; Sayer, Nina

2015-01-01

The study assessed sustainability of the Family Care Map, a family-centered approach to providing care for Veterans with polytrauma-related injuries, in four Department of Veterans Affairs Polytrauma Rehabilitation Centers. We applied a mixed-methods approach. Staff surveys used standardized measures of sustainability, commitment to change, information, and participation during implementation. Qualitative inquiry assessed Family Care Map implementation and facilitators and barriers to sustainability. Staff sustainability perceptions had a significant positive correlation with affective commitment to change, participation, and information received about the change process. Family Care Map integration into standard practices and use of its concepts with patients and families related to staff perceptions about sustainability. The degree of use and integration of the Family Care Map in traumatic brain injury/polytrauma care varied among the Polytrauma Rehabilitation Centers. Some successful sustainability strategies included integration into daily workflow and organizational culture. Examples of sustainability barriers included staff awareness and use and outdated information. Some practices, such as measuring and documenting the use of the Family Care Map in treatment plans, may not routinely occur. The focus on family-centered care will require further evaluation of organization-, staff-, and innovation-level attributes that influence sustainability of changes designed to improve family-centered care. PMID:25671632

PACS for imaging centers.

Science.gov (United States)

Farnsworth, T J

2003-01-01

PACS can be a difficult and confusing decision for any radiology provider, but it can be an even more dynamic question for an outpatient imaging center. Every center represents a unique situation and requires a specialized solution. Typically, most of what is said and discussed about PACS concentrates on solutions and requirements for hospital radiology facilities. Administrators of imaging centers have different problems from hospital administrators, and they need different answers. For imaging centers, the financial justification for PACS may be less immediate than for hospitals. The first thing that must be understood is that no PAC system can make a typical imaging center completely filmless, at least not for quite a while. A hospital has the ability to dictate to its internal referring physicians how a radiological study is delivered, whereas in an imaging center environment, the roles are very much reversed. Once the justification are made for the financial viability of PACS in an imaging center, the next question is how to finance the acquisition of PACS. The decision will depend on how you cost justify your PACS, as well as the shape of your business model, and it will come to a decision between capital purchase or contracting with an application service provider, or ASP. Historically, in the hospital-dominated marketplace, PAC systems have been treated as capital acquisitions. However, for most imaging center, owning the system is more of a problem than a benefit. ASPs increasingly represent a successful alternative for imaging centers. One of the biggest things to consider with PACS is how to store all of those images. There are typically two options, on-site and off-site, with a new "hybrid" option surfacing more recently. Each option has benefits for the user, but the benefits of off-site storage are increasing as the technology advances. Some of the benefits are data security and access. Other issues to address are HIPAA compliance, standardized

INFINITY at NASA Stennis Space Center

Science.gov (United States)

2010-01-01

Flags are planted on the roof of the new INFINITY at NASA Stennis Space Center facility under construction just west of the Mississippi Welcome Center at exit 2 on Interstate 10. Stennis and community leaders celebrated the 'topping out' of the new science center Nov. 17, marking a construction milestone for the center. The 72,000-square-foot science and education center will feature space and Earth galleries to showcase the science that underpins the missions of the agencies at Stennis Space Center. The center is targeted to open in 2012.

The guiding center Lagrangian

International Nuclear Information System (INIS)

Larsson, J.

1986-01-01

Recursion relations determining the guiding center Langrangian Λ and the associated guiding center variables to all orders are derived. We consider some particularly simple forms of Λ obtainable by specific choices of certain arbitrary functions appearing as free parameters in the theory. It is, for example, possible to locally define the guiding center variables so that the expression for the corresponding Langrangian is unchanged by all higher order terms. (orig.)

Large-scale fuel cycle centers

International Nuclear Information System (INIS)

Smiley, S.H.; Black, K.M.

1977-01-01

The United States Nuclear Regulatory Commission (NRC) has considered the nuclear energy center concept for fuel cycle plants in the Nuclear Energy Center Site Survey - 1975 (NECSS-75) -- an important study mandated by the U.S. Congress in the Energy Reorganization Act of 1974 which created the NRC. For the study, NRC defined fuel cycle centers to consist of fuel reprocessing and mixed oxide fuel fabrication plants, and optional high-level waste and transuranic waste management facilities. A range of fuel cycle center sizes corresponded to the fuel throughput of power plants with a total capacity of 50,000 - 300,000 MWe. The types of fuel cycle facilities located at the fuel cycle center permit the assessment of the role of fuel cycle centers in enhancing safeguarding of strategic special nuclear materials -- plutonium and mixed oxides. Siting of fuel cycle centers presents a considerably smaller problem than the siting of reactors. A single reprocessing plant of the scale projected for use in the United States (1500-2000 MT/yr) can reprocess the fuel from reactors producing 50,000-65,000 MWe. Only two or three fuel cycle centers of the upper limit size considered in the NECSS-75 would be required in the United States by the year 2000 . The NECSS-75 fuel cycle center evaluations showed that large scale fuel cycle centers present no real technical difficulties in siting from a radiological effluent and safety standpoint. Some construction economies may be attainable with fuel cycle centers; such centers offer opportunities for improved waste management systems. Combined centers consisting of reactors and fuel reprocessing and mixed oxide fuel fabrication plants were also studied in the NECSS. Such centers can eliminate not only shipment of plutonium, but also mixed oxide fuel. Increased fuel cycle costs result from implementation of combined centers unless the fuel reprocessing plants are commercial-sized. Development of plutonium-burning reactors could reduce any

76 FR 39811 - International Center for Technology Assessment and the Center for Food Safety; Noxious Weed...

Science.gov (United States)

2011-07-07

... dated July 18, 2002, the International Center for Technology Assessment and the Center for Food Safety... Inspection Service [Docket No. APHIS-2011-0081] International Center for Technology Assessment and the Center for Food Safety; Noxious Weed Status of Kentucky Bluegrass Genetically Engineered for Herbicide...

PTSD: National Center for PTSD

Medline Plus

Full Text Available ... Budget, & Performance VA Center for Innovation (VACI) Agency Financial Report (AFR) Budget Submission Recovery Act Resources Business ... Community Providers and Clergy Co-Occurring Conditions Continuing Education Publications List of Center Publications Articles by Center ...

PTSD: National Center for PTSD

Medline Plus

Full Text Available ... Centers Regional Benefits Offices Regional Loan Centers Cemetery Locations Get help from Veterans Crisis Line Search Enter ... Experience (TEE) Tournament Wheelchair Games Winter Sports Clinic Locations Hospitals & Clinics Vet Centers Regional Benefits Offices Regional ...

PTSD: National Center for PTSD

Medline Plus

Full Text Available ... Performance VA Plans, Budget, & Performance VA Center for Innovation (VACI) Agency Financial Report (AFR) Budget Submission Recovery ... Community Providers and Clergy Co-Occurring Conditions Continuing Education Publications List of Center Publications Articles by Center ...

Technology Information Center

International Nuclear Information System (INIS)

Emerson, E.L.; Shepherd, E.W.; Minor, E.E.

1980-01-01

A Transportation Technology Center (TTC) has been established at Sandia to address the transportation of nuclear waste and spent fuel. The Technology Information Center (TIC) acts as TTC's clearing house for nuclear material transportation information. TIC's activities are divided into three activities: public information, policy information, and technical information. Some of the uses of TIC's activities are briefly outlined

Center for Functional Nanomaterials

Data.gov (United States)

Federal Laboratory Consortium — The Center for Functional Nanomaterials (CFN) explores the unique properties of materials and processes at the nanoscale. The CFN is a user-oriented research center...

PTSD: National Center for PTSD

Medline Plus

Full Text Available ... TEE) Tournament Wheelchair Games Winter Sports Clinic Locations Hospitals & Clinics Vet Centers Regional Benefits Offices Regional Loan Centers ... Prevention / Wellness Public Health Weight Management (MOVE!) Locations Hospitals & Clinics Vet Centers Veterans Canteen Service (VCS) Research Research ...

42 CFR 124.515 - Compliance alternative for community health centers, migrant health centers and certain National...

Science.gov (United States)

2010-10-01

..., migrant health centers and certain National Health Service Corps sites. 124.515 Section 124.515 Public... Unable To Pay § 124.515 Compliance alternative for community health centers, migrant health centers and... migrant health center under section 329 of the Act is in substantial compliance with the terms and...

Human-Centered Design Capability

Science.gov (United States)

Fitts, David J.; Howard, Robert

2009-01-01

For NASA, human-centered design (HCD) seeks opportunities to mitigate the challenges of living and working in space in order to enhance human productivity and well-being. Direct design participation during the development stage is difficult, however, during project formulation, a HCD approach can lead to better more cost-effective products. HCD can also help a program enter the development stage with a clear vision for product acquisition. HCD tools for clarifying design intent are listed. To infuse HCD into the spaceflight lifecycle the Space and Life Sciences Directorate developed the Habitability Design Center. The Center has collaborated successfully with program and project design teams and with JSC's Engineering Directorate. This presentation discusses HCD capabilities and depicts the Center's design examples and capabilities.

To center or not to center? Investigating inertia with a multilevel autoregressive model

Directory of Open Access Journals (Sweden)

Ellen L. Hamaker

2015-01-01

Full Text Available Whether level 1 predictors should be centered per cluster has received considerable attention in the multilevel literature. While most agree that there is no one preferred approach, it has also been argued that cluster mean centering is desirable when the within-cluster slope and the between-cluster slope are expected to deviate, and the main interest is in the within-cluster slope. However, we show in a series of simulations that if one has a multilevel autoregressive model in which the level 1 predictor is the lagged outcome variable (i.e., the outcome variable at the previous occasion, cluster mean centering will in general lead to a downward bias in the parameter estimate of the within-cluster slope (i.e., the autoregressive relationship. This is particularly relevant if the main question is whether there is on average an autoregressive effect. Nonetheless, we show that if the main interest is in estimating the effect of a level 2 predictor on the autoregressive parameter (i.e., a cross-level interaction, cluster mean centering should be preferred over other forms of centering. Hence, researchers should be clear on what is considered the main goal of their study, and base their choice of centering method on this when using a multilevel autoregressive model.

Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers

Science.gov (United States)

Zhao, Dengwu; Duan, Haoze; Yu, Shengtao; Zhang, Yao; He, Jiaqing; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2015-01-01

This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems. PMID:26606898

PSI-Center Final Progress Report

Energy Technology Data Exchange (ETDEWEB)

Jarboe, Thomas R. [Univ. of Washington, Seattle, WA (United States); Shumlak, Uri [Univ. of Washington, Seattle, WA (United States); Sovinec, Carl [Univ. of Washington, Seattle, WA (United States); Hansen, Chris [Univ. of Washington, Seattle, WA (United States); Ji, Jeong-Young [Utah State Univ., Logan, UT (United States); Nelson, Brian [Univ. of Wisconsin, Madison, WI (United States)

2017-04-20

This is the Final Progress Report of the Plasma Science and Innovation Center (PSI-Center) covering March 2014 through February 2017. The Center has accomplished a great deal during this period. The PSI-Center is organized into four groups: Edge and Dynamic Neutrals; Transport and Kinetic Effects; Equilibrium, Stability, and Kinetic Effects in 3D Topologies; and Interface for Validation. Each group has made good progress and the results from each group are given in detail.

Allegheny County Kane Regional Center Census

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Total number of residents in each Kane Regional Center facility by race and gender. The Kane Regional Centers are skilled nursing and rehabilitation centers run by...

Pengembangan Model Manajemen ICT Center

Directory of Open Access Journals (Sweden)

Hakkun Elmunsyah

2013-01-01

Full Text Available Abstrak: Pengembangan Model Manajemen ICT Center. Kemendiknas telah melakukan investasi  cukup besar berupa pembangunan Jejaring komputer pendidikan nasional yang disebut Jaringan Pendidikan Nasional (Jardiknas, pada sekolah menengah kejuruan (SMK di seluruh Indonesia yang dikenal dengan nama ICT center. Penelitian ini bertujuan untuk menemukan model manajemen ICT center sesuai karakteristik SMK sehingga dapat memberikan kontribusi mutu pada SMK tersebut. Penelitian ini merupakan penelitian pengembangan atau Research and Development yang dikembangkan oleh Borg and Gall. Hasil secara keseluruhan penelitian menunjukkan berdasarkan uji coba keefektivan kinerja manajemen pada skala terbatas dan lebih luas menunjukkan bahwa model manajemen ICT center memenuhi kriteria sangat efektif. Kata-kata kunci: Jardiknas, SMK, model manajemen ICT center, kontribusi mutu

75 FR 6032 - National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation...

Science.gov (United States)

2010-02-05

... for OMB Review; National Contact Center Customer Evaluation Survey AGENCY: Citizen Services and Communications, Federal Consumer Information Center, GSA. ACTION: Notice of request for comments regarding a... collection requirement regarding the National Contact Center customer evaluation survey. A request for public...

Tornadoes: A Center Approach.

Science.gov (United States)

Christman-Rothlein, Liz; Meinbach, Anita M.

1981-01-01

Information is given on how to put together a learning center. Discusses information and activity packets for a complete learning center on tornadoes including objectives, directions, materials, photographs of physical arrangements, and posttest. (DC)

School-Based Health Centers

Science.gov (United States)

... care group, such as a community health center, hospital, or health department. A few are run by the school district itself. Centers often get money from charities and the government so they can give care ...

REGIONAL LOGISTICS CENTER: FORMATION AND FUNCTIONING SPESIFIC

Directory of Open Access Journals (Sweden)

Oleg Tkach

2017-08-01

Full Text Available In this article the essence of the definition of logistics centers is defined, the main provisions concerning the formation of the logistics center are defined. The formation of a logistic hub is analyzed. The structure of the transport-logistic center is proposed. The basic requirements for the location of the regional logistics center and the principles of its operation are determined. The financial and financial mechanism of a typical logistics center and their effective functioning are presented. It is proved that the most important component of the logistics center is transport. Key words: logistics centers, logistics, hub, distribution centers, transport and logistics centers, regional logistic centers, logistics complex, transport, transport-logistic system.

Heme iron content in lamb meat is differentially altered upon boiling, grilling, or frying as assessed by four distinct analytical methods.

Science.gov (United States)

Pourkhalili, Azin; Mirlohi, Maryam; Rahimi, Ebrahim

2013-01-01

Lamb meat is regarded as an important source of highly bioavailable iron (heme iron) in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC) were used for proximate analysis. For measuring heme iron, the results of four experimental methods were compared regarding their compliance to Ferrozine method which was used for the determination of nonheme iron. Among three cooking methods, the lowest total iron and heme iron were found in boiling method. The heme iron proportions to the total iron in raw, boiled lamb meat and grilled, were counted as 65.70%, 67.75%, and 76.01%, receptively. Measuring the heme iron, the comparison of the methods in use showed that the method in which heme extraction solution was composed of 90% acetone, 18% water, and 2% hydrochloric acid was more appropriate and more correlated with the heme iron content calculated by the difference between total iron and nonheme iron.

Heme Iron Content in Lamb Meat Is Differentially Altered upon Boiling, Grilling, or Frying as Assessed by Four Distinct Analytical Methods

Directory of Open Access Journals (Sweden)

Azin Pourkhalili

2013-01-01

Full Text Available Lamb meat is regarded as an important source of highly bioavailable iron (heme iron in the Iranians diet. The main objective of this study is to evaluate the effect of traditional cooking methods on the iron changes in lamb meat. Four published experimental methods for the determination of heme iron were assessed analytically and statistically. Samples were selected from lambs' loin. Standard methods (AOAC were used for proximate analysis. For measuring heme iron, the results of four experimental methods were compared regarding their compliance to Ferrozine method which was used for the determination of nonheme iron. Among three cooking methods, the lowest total iron and heme iron were found in boiling method. The heme iron proportions to the total iron in raw, boiled lamb meat and grilled, were counted as 65.70%, 67.75%, and 76.01%, receptively. Measuring the heme iron, the comparison of the methods in use showed that the method in which heme extraction solution was composed of 90% acetone, 18% water, and 2% hydrochloric acid was more appropriate and more correlated with the heme iron content calculated by the difference between total iron and nonheme iron.

Find a Health Center

Data.gov (United States)

U.S. Department of Health & Human Services — HRSA Health Centers care for you, even if you have no health insurance – you pay what you can afford based on your income. Health centers provide services that...

Potential energy center site investigations

International Nuclear Information System (INIS)

Savage, W.F.

1977-01-01

Past studies by the AEC, NRC, NSF and others have indicated that energy centers have certain advantages over dispersed siting. There is the need, however, to investigate such areas as possible weather modifications due to major heat releases, possible changes in Federal/state/local laws and institutional arrangements to facilitate implementation of energy centers, and to assess methods of easing social and economic pressures on a surrounding community due to center construction. All of these areas are under study by ERDA, but there remains the major requirement for the study of a potential site to yield a true assessment of the energy center concept. In this regard the Division of Nuclear Research and Applications of ERDA is supporting studies by the Southern and Western Interstate Nuclear Boards to establish state and utility interest in the concept and to carry out screening studies of possible sites. After selection of a final site for center study , an analysis will be made of the center including technical areas such as heat dissipation methods, water resource management, transmission methods, construction methods and schedules, co-located fuel cycle facilities, possible mix of reactor types, etc. Additionally, studies of safeguards, the interaction of all effected entities in the siting, construction, licensing and regulation of a center, labor force considerations in terms of local impact, social and economic changes, and financing of a center will be conducted. It is estimated that the potential site study will require approximately two years

Tehran Nuclear Research Center

International Nuclear Information System (INIS)

Taherzadeh, M.

1977-01-01

The Tehran Nuclear Research Center was formerly managed by the University of Tehran. This Center, after its transformation to the AEOI, has now become a focal point for basic research in the area of Nuclear Energy in Iran

Carbon Monoxide Information Center

Medline Plus

Full Text Available ... OnSafety Blog Safety Education Centers Neighborhood Safety Network Community Outreach Resource Center Toy Recall Statistics CO Poster ... Sitemap RSS E-mail Inside CPSC Accessibility Privacy Policy Budget, Performances & Finance Open Government Freedom of Information ( ...

Genetic Science Learning Center

Science.gov (United States)

Genetic Science Learning Center Making science and health easy for everyone to understand Home News Our Team What We Do ... Collaboration Conferences Current Projects Publications Contact The Genetic Science Learning Center at The University of Utah is a ...

Correlations between Abelian monopoles and center vortices

Energy Technology Data Exchange (ETDEWEB)

Hosseini Nejad, Seyed Mohsen, E-mail: smhosseininejad@ut.ac.ir; Deldar, Sedigheh, E-mail: sdeldar@ut.ac.ir

2017-04-15

We study the correlations between center vortices and Abelian monopoles for SU(3) gauge group. Combining fractional fluxes of monopoles, center vortex fluxes are constructed in the thick center vortex model. Calculating the potentials induced by fractional fluxes constructing the center vortex flux in a thick center vortex-like model and comparing with the potential induced by center vortices, we observe an attraction between fractional fluxes of monopoles constructing the center vortex flux. We conclude that the center vortex flux is stable, as expected. In addition, we show that adding a contribution of the monopole-antimonopole pairs in the potentials induced by center vortices ruins the Casimir scaling at intermediate regime.

Techniques for evaluating optimum data center operation

Science.gov (United States)

Hamann, Hendrik F.; Rodriguez, Sergio Adolfo Bermudez; Wehle, Hans-Dieter

2017-06-14

Techniques for modeling a data center are provided. In one aspect, a method for determining data center efficiency is provided. The method includes the following steps. Target parameters for the data center are obtained. Technology pre-requisite parameters for the data center are obtained. An optimum data center efficiency is determined given the target parameters for the data center and the technology pre-requisite parameters for the data center.

Alternative Fuels Data Center: Natural Gas

Science.gov (United States)

Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Natural Gas on

Determinants of U.S. poison center utilization.

Science.gov (United States)

Litovitz, Toby; Benson, Blaine E; Youniss, Jessica; Metz, Edward

2010-06-01

High poison center utilization has been associated with decreased emergency department usage and hospitalization rates. However, utilization requires awareness of the poison center. Penetrance, defined as the number of human poison exposures reported to a poison center per 1,000 population, has been used as a marker of poison center awareness. To identify factors that influence poison center penetrance to optimize the life- and cost-saving benefits of poison control centers. Human poison exposures that were reported to the National Poison Data System in 2001 were analyzed to identify and rank factors affecting poison center penetrance. Overall penetrance correlated with pediatric penetrance (R(2) = 0.75, p poison center that were already in or en route to a healthcare facility at the time of the call to the poison center (R(2) = 0.41, p poison center service populations were associated with lower penetrance (R(2) = 0.23, p poison center (multiple regression). Positive predictors included the percentage of the population younger than 5 years, the percentage of the adult population with a bachelor's degree, poison center certification, poison center educator FTEs (full time equivalents), Asian population percentage, and population density. The inverse correlation between pediatric penetrance and healthcare facility utilization supports prior observations of excessive healthcare utilization when a poison center is not called. Since race, language and distance are barriers to poison center utilization, and since healthcare utilization increases when poison center penetrance declines, low penetrance suggests a lack of awareness of the poison center rather than a low incidence of poisonings. Strategies to raise penetrance should be informed by an understanding of the barriers to utilization - language, Black/African American race, distance from the poison center, poverty, and lower education levels.

The Soviet center of astronomical data

International Nuclear Information System (INIS)

Dluzhnevskaya, O.B.

1982-01-01

On the basis of the current French-Soviet cooperation in science and technology, the Astronomical Council of the U.S.S.R. Academy of Sciences and the Strasbourg Center signed in 1977 an agreement on setting up the Soviet Center of Astronomical Data as its filial branch. The Soviet Center was created on the basis of a computation center at the Zvenigorod station of the Astronomical Council of the U.S.S.R. Academy of Sciences, which had already had considerable experience of working with stellar catalogues. In 1979 the Center was equipped with a EC-1033 computer. In 1978-1979 the Soviet Center of Astronomical Data (C.A.D.) received from Strasbourg 96 of the most important catalogues. By September 1981 the list of catalogues available at the Soviet Center has reached 140 catalogues some of which are described. (Auth.)

Spatial Distribution of Market Centers

Directory of Open Access Journals (Sweden)

Md. Morshedul Islam

2018-03-01

Full Text Available The present study is an attempt to find the location pattern, distribution and their sphere of influences of market centers in Rangpur City Corporation, Bangladesh. Rangpur is facing some problems like a traffic jam, noisy environment, population pressure etc due to the over population in full day long in the center of this city, all of the whole sale and retail sale markets are located in the middle. Location of Market is always influencing the daily life of the city population who are directly or indirectly connected with the market. If the market strategically distributed in an area they don’t face such kind of problems. Analysis or investigation shows that at about all of the market centers are located in the center of Rangpur and in the residential area of Rangpur. The maximum 67% market centers are found in the high-income residential area. Rangpur City Corporation, Bangladesh Bureau of Statistics and survey of Bangladesh provided the maps, reports and relevant documents of the study. The spatial dispersion pattern of market centers is clustered together at one place 0.33(Nearest Neighbor Index value, R found in the study area. Geographical Information System (GIS and other software also used to analyze the maps and diagrams. Investigation refers that, the market of Rangpur city have a clustered pattern and different levels of market centers found on the bases of centrality scores. By this centrality scores or levels, found the variation of influencing spheres of market centers in Rangpur City.

Implementing the patient-centered medical home in complex adaptive systems: Becoming a relationship-centered patient-centered medical home.

Science.gov (United States)

Flieger, Signe Peterson

This study explores the implementation experience of nine primary care practices becoming patient-centered medical homes (PCMH) as part of the New Hampshire Citizens Health Initiative Multi-Stakeholder Medical Home Pilot. The purpose of this study is to apply complex adaptive systems theory and relationship-centered organizations theory to explore how nine diverse primary care practices in New Hampshire implemented the PCMH model and to offer insights for how primary care practices can move from a structural PCMH to a relationship-centered PCMH. Eighty-three interviews were conducted with administrative and clinical staff at the nine pilot practices, payers, and conveners of the pilot between November and December 2011. The interviews were transcribed, coded, and analyzed using both a priori and emergent themes. Although there is value in the structural components of the PCMH (e.g., disease registries), these structures are not enough. Becoming a relationship-centered PCMH requires attention to reflection, sensemaking, learning, and collaboration. This can be facilitated by settings aside time for communication and relationship building through structured meetings about PCMH components as well as the implementation process itself. Moreover, team-based care offers a robust opportunity to move beyond the structures to focus on relationships and collaboration. (a) Recognize that PCMH implementation is not a linear process. (b) Implementing the PCMH from a structural perspective is not enough. Although the National Committee for Quality Assurance or other guidelines can offer guidance on the structural components of PCMH implementation, this should serve only as a starting point. (c) During implementation, set aside structured time for reflection and sensemaking. (d) Use team-based care as a cornerstone of transformation. Reflect on team structures and also interactions of the team members. Taking the time to reflect will facilitate greater sensemaking and learning and

Reliability Centered Maintenance - Methodologies

Science.gov (United States)

Kammerer, Catherine C.

2009-01-01

Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

Person-Centered Transition Planning.

Science.gov (United States)

Miner, Craig A.; Bates, Paul E.

1997-01-01

Describes a person-centered planning approach for involving students with disabilities and their families in the transition planning process. Components of person-centered planning are discussed, including development of a personal profile, identification of future lifestyle preferences, action steps and responsible parties, and necessary changes…

EXFOR Manual. Center-to-Center Exchange Format. Version 89-1

International Nuclear Information System (INIS)

McLane, V.

1989-09-01

EXFOR is the agreed exchange format for the transmission of nuclear reaction data between national and international nuclear data centers for the benefit of nuclear data users in all countries. EXFOR is a database with several million data records containing the world's experimental nuclear reaction data induced by neutrons, photons or charged particles. Data retrievals can be obtained from the IAEA Nuclear Data Section (NDS) or from one of the co-operating data centers whose names and addresses can be found inside the manual. Their contributions and co-operative efforts are gratefully acknowledged. (author). Refs

From Periphery To Center

DEFF Research Database (Denmark)

Carré, David

2014-01-01

the notions of Center/Periphery. As Hermans (2001) proposed, center and periphery are not fixed ‘I-positions’ of the self; in this vein, these notions are explored as relevant theoretical tools for addressing the developmental trajectories involved in the construction of scientific identities. In sum...

Models for non-heme iron containing oxidation enzymes

NARCIS (Netherlands)

Roelfes, Johannes Gerhardus

2000-01-01

IJzer is een van de essentiël elementen voor alle levende wezens. Heel veel belangrijke functies in organismen worden vervuld door ijzer bevattende eiwitten. De bekendste voorbeelden hiervan zijn ongetwijfeld hemoglobine en myoglobine, die het transport van zuurstof van de longen naar de rest van

15 CFR 290.8 - Reviews of centers.

Science.gov (United States)

2010-01-01

... TRANSFER OF MANUFACTURING TECHNOLOGY § 290.8 Reviews of centers. (a) Overview. Each Center will be reviewed... involved Center, and Federal officials. An official of NIST shall chair the panel. Each Merit Review Panel... Center be provided by the NIST Manufacturing Technology Centers Program after the sixth year of support...

Probability distribution of machining center failures

International Nuclear Information System (INIS)

Jia Yazhou; Wang Molin; Jia Zhixin

1995-01-01

Through field tracing research for 24 Chinese cutter-changeable CNC machine tools (machining centers) over a period of one year, a database of operation and maintenance for machining centers was built, the failure data was fitted to the Weibull distribution and the exponential distribution, the effectiveness was tested, and the failure distribution pattern of machining centers was found. Finally, the reliability characterizations for machining centers are proposed

Analysis of hypoxia and hypoxia-like states through metabolite profiling.

Directory of Open Access Journals (Sweden)

Julie E Gleason

Full Text Available In diverse organisms, adaptation to low oxygen (hypoxia is mediated through complex gene expression changes that can, in part, be mimicked by exposure to metals such as cobalt. Although much is known about the transcriptional response to hypoxia and cobalt, little is known about the all-important cell metabolism effects that trigger these responses.Herein we use a low molecular weight metabolome profiling approach to identify classes of metabolites in yeast cells that are altered as a consequence of hypoxia or cobalt exposures. Key findings on metabolites were followed-up by measuring expression of relevant proteins and enzyme activities. We find that both hypoxia and cobalt result in a loss of essential sterols and unsaturated fatty acids, but the basis for these changes are disparate. While hypoxia can affect a variety of enzymatic steps requiring oxygen and heme, cobalt specifically interferes with diiron-oxo enzymatic steps for sterol synthesis and fatty acid desaturation. In addition to diiron-oxo enzymes, cobalt but not hypoxia results in loss of labile 4Fe-4S dehydratases in the mitochondria, but has no effect on homologous 4Fe-4S dehydratases in the cytosol. Most striking, hypoxia but not cobalt affected cellular pools of amino acids. Amino acids such as aromatics were elevated whereas leucine and methionine, essential to the strain used here, dramatically decreased due to hypoxia induced down-regulation of amino acid permeases.These studies underscore the notion that cobalt targets a specific class of iron proteins and provide the first evidence for hypoxia effects on amino acid regulation. This research illustrates the power of metabolite profiling for uncovering new adaptations to environmental stress.

Precision Joining Center

Science.gov (United States)

Powell, J. W.; Westphal, D. A.

1991-08-01

A workshop to obtain input from industry on the establishment of the Precision Joining Center (PJC) was held on July 10-12, 1991. The PJC is a center for training Joining Technologists in advanced joining techniques and concepts in order to promote the competitiveness of U.S. industry. The center will be established as part of the DOE Defense Programs Technology Commercialization Initiative, and operated by EG&G Rocky Flats in cooperation with the American Welding Society and the Colorado School of Mines Center for Welding and Joining Research. The overall objectives of the workshop were to validate the need for a Joining Technologists to fill the gap between the welding operator and the welding engineer, and to assure that the PJC will train individuals to satisfy that need. The consensus of the workshop participants was that the Joining Technologist is a necessary position in industry, and is currently used, with some variation, by many companies. It was agreed that the PJC core curriculum, as presented, would produce a Joining Technologist of value to industries that use precision joining techniques. The advantage of the PJC would be to train the Joining Technologist much more quickly and more completely. The proposed emphasis of the PJC curriculum on equipment intensive and hands-on training was judged to be essential.

Are All Spatial Reference Frames Egocentric? Reinterpreting Evidence for Allocentric, Object-Centered, or World-Centered Reference Frames

OpenAIRE

Filimon, Flavia

2015-01-01

The use and neural representation of egocentric spatial reference frames is well-documented. In contrast, whether the brain represents spatial relationships between objects in allocentric, object-centered, or world-centered coordinates is debated. Here, I review behavioral, neuropsychological, neurophysiological (neuronal recording), and neuroimaging evidence for and against allocentric, object-centered, or world-centered spatial reference frames. Based on theoretical considerations, simulati...

Complex centers of polynomial differential equations

Directory of Open Access Journals (Sweden)

Mohamad Ali M. Alwash

2007-07-01

Full Text Available We present some results on the existence and nonexistence of centers for polynomial first order ordinary differential equations with complex coefficients. In particular, we show that binomial differential equations without linear terms do not have complex centers. Classes of polynomial differential equations, with more than two terms, are presented that do not have complex centers. We also study the relation between complex centers and the Pugh problem. An algorithm is described to solve the Pugh problem for equations without complex centers. The method of proof involves phase plane analysis of the polar equations and a local study of periodic solutions.

Center vortex properties in the Laplace center gauge of SU(2) Yang-Mills theory

OpenAIRE

Langfeld, K.; Reinhardt, H.; Schafke, A.

2001-01-01

Resorting to the the Laplace center gauge (LCG) and to the Maximal-center gauge (MCG), respectively, confining vortices are defined by center projection in either case. Vortex properties are investigated in the continuum limit of SU(2) lattice gauge theory. The vortex (area) density and the density of vortex crossing points are investigated. In the case of MCG, both densities are physical quantities in the continuum limit. By contrast, in the LCG the piercing as well as the crossing points li...

World data centers

Science.gov (United States)

Shapley, Alan H.; Hart, Pembroke J.

One of the lasting heritages of the International Geophysical Year (1957-58) is the system of world data centers (WDC) through which there has been international exchange of a wide variety of geophysical data on a continuing basis. This voluntary exchange mechanism has been remarkably successful. The basic operating costs of the centers are provided by the host country. The international exchanges are mainly by barter. The data providers number in the thousands and the users in the tens of thousands.

The Revitalized Tutoring Center

Science.gov (United States)

Koselak, Jeremy

2017-01-01

One high-leverage strategy rooted in a strong research base--the revitalized tutoring center--provides a wealth of opportunity to students who may be otherwise underserved. This embedded, open-all-day tutoring center supports collaborative teacher teams by using peer tutors and community volunteers. By centralizing resources and providing supports…

Electrolysis activities at FCH Test Center

DEFF Research Database (Denmark)

Ravn Nielsen, Eva; Nygaard, Frederik Berg

FCH Test Center for fuel cell and hydrogen technologies was established in 2010 at Risø DTU in Denmark. Today, the test center is part of DTU Energy Conversion. The center gives industry access to advanced testing and demonstration of components and systems. A number of national projects and EU...... projects regarding water electrolysis involve FCH Test Center as a partner. This presentation gives an overview of the activities....

Production and Distribution Research Center

Science.gov (United States)

1986-05-01

Steel, Coca Cola , Standard Oil of Ohio, and Martin Marietta have been involved in joint research with members of the Center. The number of Faculty...permitted the establishment of the Center and supports its continuing development. The Center has also received research sponsorship from the Joint...published relating to results developed within the PDRC under Offce of Naval Research sponsorship . These reports are listed in Appendix A. Many of these

What Are the Costs of Trauma Center Readiness? Defining and Standardizing Readiness Costs for Trauma Centers Statewide.

Science.gov (United States)

Ashley, Dennis W; Mullins, Robert F; Dente, Christopher J; Garlow, Laura; Medeiros, Regina S; Atkins, Elizabeth V; Solomon, Gina; Abston, Dena; Ferdinand, Colville H

2017-09-01

Trauma center readiness costs are incurred to maintain essential infrastructure and capacity to provide emergent services on a 24/7 basis. These costs are not captured by traditional hospital cost accounting, and no national consensus exists on appropriate definitions for each cost. Therefore, in 2010, stakeholders from all Level I and II trauma centers developed a survey tool standardizing and defining trauma center readiness costs. The survey tool underwent minor revisions to provide further clarity, and the survey was repeated in 2013. The purpose of this study was to provide a follow-up analysis of readiness costs for Georgia's Level I and Level II trauma centers. Using the American College of Surgeons Resources for Optimal Care of the Injured Patient guidelines, four readiness cost categories were identified: Administrative, Clinical Medical Staff, Operating Room, and Education/Outreach. Through conference calls, webinars and face-to-face meetings with financial officers, trauma medical directors, and program managers from all trauma centers, standardized definitions for reporting readiness costs within each category were developed. This resulted in a survey tool for centers to report their individual readiness costs for one year. The total readiness cost for all Level I trauma centers was $34,105,318 (avg $6,821,064) and all Level II trauma centers was $20,998,019 (avg $2,333,113). Methodology to standardize and define readiness costs for all trauma centers within the state was developed. Average costs for Level I and Level II trauma centers were identified. This model may be used to help other states define and standardize their trauma readiness costs.

International Water Center

Science.gov (United States)

The urban district of Nancy and the Town of Nancy, France, have taken the initiative of creating an International Center of Water (Centre International de l'Eau à Nancy—NAN.C.I.E.) in association with two universities, six engineering colleges, the Research Centers of Nancy, the Rhine-Meuse Basin Agency, and the Chamber of Commerce and Industry. The aim of this center is to promote research and technology transfer in the areas of water and sanitation. In 1985 it will initiate a research program drawing on the experience of 350 researchers and engineers of various disciplines who have already been assigned to research in these fields. The research themes, the majority of which will be multidisciplinary, concern aspects of hygiene and health, the engineering of industrial processes, water resources, and the environment and agriculture. A specialist training program offering five types of training aimed at university graduates, graduates of engineering colleges, or experts, will start in October 1984.

Bistable amphoteric centers in semiconductors

International Nuclear Information System (INIS)

Nikitina, A. G.; Zuev, V. V.

2008-01-01

It is shown that, at thermodynamic equilibrium, the release of charge carriers from the localized states of bistable amphoteric centers into quasi-free states depends on the degree of compensation. This brings about different functional dependences of the concentration of free charge carriers on temperature. It is found that, in uncompensated semiconductors, the concentration of free charge carriers follows the same dependence in the case of bistable amphoteric centers and bistable amphoteric U - centers, although the distributions of charge carriers over the charge states and configurations are different for these types of centers. The results can be used for interpreting various experimental data insufficiently explained in the context of the traditional approach

DEVELOPMENT OF SIMULATION CENTER AND TRAINING PROGRAMMES IN IVANO-FRANKIVSK PERINATAL CENTER

Directory of Open Access Journals (Sweden)

Zoryana Kocherga

2017-06-01

Full Text Available Current system of medical education in Ukraine needs improvement and reforms in order to enhance the proficiency of doctors and paramedics. Training of practical/technical skills, communication, as well as teamwork skills is considerably important.The use of simulation techniques and methods in medical education is called simulation training in medicine. Medical skills are acquired through cognitive (knowledge and psychomotor (practice skills. The first medical simulation centers appeared in Ukraine in 2006 according to the order of the Ministry of Health Care of Ukraine.On June 20, 2013, a new simulation training center was opened in Ivano-Frankivsk on the base of Regional Perinatal Center. Similar medical simulation centers were opened in the second half of 2013 in Volyn and Vinnytsia regions under the Ukrainian-Swiss Mother and Child Health Programme, which started in the area of perinatology. Their goal is to improve the teamwork of all specialists involved in the process of delivery and neonatal intensive care,as well as to engage internship doctors and senior medical students in clinical skills training programmes.The use of simulation techniques and training programs offers a powerful platform to study and practice clinical reasoning behaviors and patterns.

Daugherty Memorial Assessment Center (DMAC)

Data.gov (United States)

Federal Laboratory Consortium — Daugherty Memorial Assessment Center (DMAC) is a 39,000-square-foot facility that doubles the warfare center's high-secured performance assessment capabilities. DMAC...

PTSD: National Center for PTSD

Medline Plus

Full Text Available ... Topics For Veterans For Researchers Research Oversight Special Groups Caregivers Combat Veterans & their Families Readjustment Counseling (Vet Centers) War Related Illness & Injury Study Center ...

VT Designated Village Centers Boundary

Data.gov (United States)

Vermont Center for Geographic Information — This community revitalization program helps maintain or evolve small to medium-sized historic centers with existing civic and commercial buildings. The designation...

Lied Transplant Center

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

The Department of Energy has prepared an Environmental Assessment (DOE/EA-1143) evaluating the construction, equipping and operation of the proposed Lied Transplant Center at the University of Nebraska Medical Center in Omaha, Nebraska. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Statement in not required.

QUAD FAMILY CENTERING

International Nuclear Information System (INIS)

PINAYEV, I.

2005-01-01

It is well known that beam position monitors (BPM) utilizing signals from pickup electrodes (PUE) provide good resolution and relative accuracy. The absolute accuracy (i.e. position of the orbit in the vacuum chamber) is not very good due to the various reasons. To overcome the limitation it was suggested to use magnetic centers of quadrupoles for the calibration of the BPM [1]. The proposed method provides accuracy better then 200 microns for centering of the beam position monitors using modulation of the whole quadrupole family

Chemistry and the iron - only hydrogenase

International Nuclear Information System (INIS)

Tard, C.; Razavet, M.; Liu, X.; Ibrahim, S.; Pickett, Ch.

2005-01-01

Complete text of publication follows: Chemistry related to the hydrogenases is developing very rapidly and providing some informative insights into how the biological systems might function. Although still very much at a blue skies stage, there is some prospect for the design of artificial assemblies, materials and devices with technological application for hydrogen production/uptake provided robust system can be designed with low over potentials for hydrogen/proton interconversion (1). The iron-only hydrogenase possesses a peculiar di-iron unit coordinated by CO and CN, ligands which are normally associated with poisoning biological function. This sub-site unit is attached to a [4Fe4S] cubane center to form the catalytic site of the hydrogenase which is known as the 'H-cluster'. The synthesis of artificial sub-sites will first be described together with how their structures, spectroscopy and reactivity provides some key insights into the natural system viz. unprecedented bridging carbonyl and Fe(I) motifs in biology (2-4). How we have approached putting together the entire iron-sulfur framework of the H-cluster will then be described together with its electron-transfer and electrocatalytic properties (4). Finally, I will describe some early work on how we are beginning to incorporate structural motifs of the active-site into conducting polymer matrices, how they function as (albeit poor) electrocatalysts for hydrogen evolution, and where we see the way ahead. (1)The Chemistry and the Hydrogenases. D.J. Evans and C.J. Pickett, Chem. Soc. Rev., 32, 268-275, 2003; (2)Electron-Transfer at a Di-thiolate-Bridged Di-Iron Assembly; Electrocatalytic Hydrogen Evolution. S.J. Borg, T. Behrsing and S.P. Best, M. Ravazet, X. Liu and C.J. Pickett, J Amer. Chem. Soc., 2004, 126, 509-533; (3) Dissecting the intimate mechanism of cyanation of [Fe2S3] complexes related to the active site of all-iron hydrogenases by DFT analysis of energetics, transition states, intermediates and

Carbon Monoxide Information Center

Medline Plus

Full Text Available ... main content Languages 简体中文 English Bahasa Indonesia 한국어 Español ภาษาไทย Tiếng Việt Text Size: Decrease Font Increase ... Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as ...

Synthesis centers as critical research infrastructure

Science.gov (United States)

Baron, Jill S.; Specht, Alison; Garnier, Eric; Bishop, Pamela; Campbell, C. Andrew; Davis, Frank W.; Fady, Bruno; Field, Dawn; Gross, Louis J.; Guru, Siddeswara M.; Halpern, Benjamin S; Hampton, Stephanie E.; Leavitt, Peter R.; Meagher, Thomas R.; Ometto, Jean; Parker, John N.; Price, Richard; Rawson, Casey H.; Rodrigo, Allen; Sheble, Laura A.; Winter, Marten

2017-01-01

Demand for the opportunity to participate in a synthesis-center activity has increased in the years since the US National Science Foundation (NSF)–funded National Center for Ecological Analysis and Synthesis (NCEAS) opened its doors in 1995 and as more scientists across a diversity of scientific disciplines have become aware of what synthesis centers provide. The NSF has funded four synthesis centers, and more than a dozen new synthesis centers have been established around the world, some following the NSF model and others following different models suited to their national funding environment (http://synthesis-consortium.org).Scientific synthesis integrates diverse data and knowledge to increase the scope and applicability of results and yield novel insights or explanations within and across disciplines (Pickett et al. 2007, Carpenter et al. 2009). The demand for synthesis comes from the pressing societal need to address grand challenges related to global change and other issues that cut across multiple societal sectors and disciplines and from recognition that substantial added scientific value can be achieved through the synthesis-based analysis of existing data. Demand also comes from groups of scientists who see exciting opportunities to generate new knowledge from interdisciplinary and transdisciplinary collaboration, often capitalizing on the increasingly large volume and variety of available data (Kelling et al. 2009, Bishop et al. 2014, Specht et al. 2015b). The ever-changing nature of societal challenges and the availability of data with which to address them suggest there will be an expanding need for synthesis.However, we are now entering a phase in which government support for some existing synthesis centers has ended or will be ending soon, forcing those centers to close or develop new operational models, approaches, and funding streams. We argue here that synthesis centers play such a unique role in science that continued long-term public

Center for Beam Physics, 1992

International Nuclear Information System (INIS)

1993-06-01

This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities

Center for Beam Physics, 1992

Energy Technology Data Exchange (ETDEWEB)

1993-06-01

This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities.

Carolinas Energy Career Center

Energy Technology Data Exchange (ETDEWEB)

Classens, Anver; Hooper, Dick; Johnson, Bruce

2013-03-31

Central Piedmont Community College (CPCC), located in Charlotte, North Carolina, established the Carolinas Energy Career Center (Center) - a comprehensive training entity to meet the dynamic needs of the Charlotte region's energy workforce. The Center provides training for high-demand careers in both conventional energy (fossil) and renewable energy (nuclear and solar technologies/energy efficiency). CPCC completed four tasks that will position the Center as a leading resource for energy career training in the Southeast: • Development and Pilot of a New Advanced Welding Curriculum, • Program Enhancement of Non-Destructive Examination (NDE) Technology, • Student Support through implementation of a model targeted toward Energy and STEM Careers to support student learning, • Project Management and Reporting. As a result of DOE funding support, CPCC achieved the following outcomes: • Increased capacity to serve and train students in emerging energy industry careers; • Developed new courses and curricula to support emerging energy industry careers; • Established new training/laboratory resources; • Generated a pool of highly qualified, technically skilled workers to support the growing energy industry sector.

Starting a sleep center.

Science.gov (United States)

Epstein, Lawrence J; Valentine, Paul S

2010-05-01

The demand for sleep medicine services has grown tremendously during the last decade and will likely continue. To date, growth in demand has been met by growth in the number of new sleep centers. The need for more new centers will be dependent on market drivers that include increasing regulatory requirements, personnel shortages, integration of home sleep testing, changes in reimbursement, a shift in emphasis from diagnostics to treatment, and an increased consumer focus on sleep. The decision to open a new center should be based on understanding the market dynamics, completing a market analysis, and developing a business plan. The business plan should include an overview of the facility, a personnel and organizational structure, an evaluation of the business environment, a financial plan, a description of services provided, and a strategy for obtaining, managing, and extending a referral base. Implementation of the business plan and successful operation require ongoing planning and monitoring of operational parameters. The need for new sleep centers will likely continue, but the shifting market dynamics indicate a greater need for understanding the marketplace and careful planning.

Viewpoints of the members of the workers' retirement centers in Tehran about elderly day care centers (2012

Directory of Open Access Journals (Sweden)

Hosein Rohani

2014-02-01

Full Text Available Background: There is no documented evidence regarding elderly day care centers in Iran. This needs analysis study was conducted to investigate the demand for elderly day care centers in Tehran. Methods: This cross-sectional study was conducted recruiting 210 participants aged over 60 who were members of the elderly retirement centers in Tehran in 2012. Data were gathered by Kansas state university questionnaire and analyzed using Mann-Whitney and Kruskal-Wallis tests. Results: About 80% of participants were men with the mean age of 67.5±5.23 years. Results showed that male (P<0.001, married (P=0.01 and literate elderly (P<0.001, and those living in rental homes (P<0.001 expressed a greater need for elderly day care centers. There was no statistically significant relationship between the lifestyle (P=0.051 and income (P=0.08 of the participants and demand for elderly day care centers. Conclusion: Given the rising population of the elderly and their high demand for day care centers, it is necessary to establish well-equipped day care centers for this group of people. Also, these centers may reduce the burden of care for the aged people on public services and family care givers.

The USC Epigenome Center.

Science.gov (United States)

Laird, Peter W

2009-10-01

The University of Southern California (USC, CA, USA) has a long tradition of excellence in epigenetics. With the recent explosive growth and technological maturation of the field of epigenetics, it became clear that a dedicated high-throughput epigenomic data production facility would be needed to remain at the forefront of epigenetic research. To address this need, USC launched the USC Epigenome Center as the first large-scale center in academics dedicated to epigenomic research. The Center is providing high-throughput data production for large-scale genomic and epigenomic studies, and developing novel analysis tools for epigenomic research. This unique facility promises to be a valuable resource for multidisciplinary research, education and training in genomics, epigenomics, bioinformatics, and translational medicine.

77 FR 3242 - Comprehensive Centers Program

Science.gov (United States)

2012-01-23

... training, technical assistance, and professional development to SEAs, LEAs, regional educational agencies..., instruction, teacher quality, innovation and improvement, or high schools. The 16 Regional Centers focused... requirements for all Regional Centers do not support the development of new content. A Regional Center...

Center for Veterinary Medicine (CVM)

Data.gov (United States)

Federal Laboratory Consortium — As seen on the center's logo, the mission statement for FDA's Center for Veterinary Medicine (CVM) reads: "Protecting Human and Animal Health." To achieve this broad...

PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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A Randomized Phase 2 Trial of 177Lu Radiolabeled Anti-PSMA Monoclonal Antibody J591 in Patients with High-Risk Castrate, Biochemically Relapsed Prostate Cancer

Science.gov (United States)

2014-09-01

Irene Karpenko Lauren Tyrell Olivera Calukovic Gillian Hodes June Greenberg Jessica Campbell PATIENTS AND THEIR FAMILIES Biostatistics...myelosuppression or need for >2 platelet (plt) transfusions, febrile neutropenia , or grade >2 non-heme toxicity following 177Lu- J591. PSA was assessed prior to...toxicity • Grade 4 neutropenia or thrombocytopenia > 14 days • Need for > 2 platelet transfusions or hemorrhage • Febrile neutropenia • > 3 week delay for

[Medical centers--methods, purpose and benefits].

Science.gov (United States)

Schrappe, Matthias

2007-01-01

The German hospital sector is characterized by a profound deficit in organizational integration. The implementation of centers as one way to improve the situation is complicated by the heterogeneity of the concept and understanding of the term "center". The author proposes to distinguish between functional, divisional and process-oriented centers. In German hospitals where the transition from functional to divisional organization is under way matrix elements can be expected to be introduced into organizational practice. Process-oriented centers like breast centers represent matrix components by simultaneously applying functional and process-oriented perspectives. Matrix components map the complexity of clinical structures, but increase coordination and management load and should be applied only to a limited number of care processes.

VT Designated Growth Center Boundary

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Vermont Center for Geographic Information — Growth centers aim to align public infrastructure and private building investments with a local framework of policies and regulations to ensure that 20 years of...

Commission for the Accreditation of Birth Centers

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... Learning Login: Commissioners Birth Centers CABC Learning Place Home Accredited Birth Centers Find CABC Accredited Birth Centers What does ... In the Pursuit of Excellence You are here: Home In the ... for the Accreditation of Birth Centers (CABC) provides support, education, and accreditation to ...

PTSD: National Center for PTSD

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Alternative Fuels Data Center: Natural Gas Benefits

Science.gov (United States)

Benefits to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Benefits on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Benefits on Twitter Bookmark Alternative Fuels Data Center: Natural Gas Benefits on Google Bookmark Alternative Fuels Data Center: Natural Gas

Nuclear data services of the Nuclear Data Centers Network available at the National Nuclear Data Center

International Nuclear Information System (INIS)

McLane, V.

1997-01-01

The Nuclear Data Centers Network provides low and medium energy nuclear reaction data to users around the world. Online retrievals are available through the U.S. National Nuclear Data Center, the Nuclear Energy Agency Data Bank, and the IAEA Nuclear Data Section from these extensive bibliographic, experimental data, and evaluated data files. In addition to nuclear reaction data, the various databases also provide nuclear structure and decay data, and other information of interest to users. The WorldWideWeb sites at the National Nuclear Data Center and the NEA Data Bank provide access to some of the Centers' files. (orig.)

International nuclear data centers and the nuclear data center of Instituto de Estudos Avancados

International Nuclear Information System (INIS)

Corcuera, R.P.; Nair, R.P.K.; Santos, R. dos

1985-01-01

The nuclear data centers existent in the world and their areas, of responsability are presented. The efforts made by the Instituto de Estudos Avancados of Centro Tecnico Aeroespacial, in Brazil to create a local nuclear data center are presented. (M.C.K.) [pt

A Paradigm Shift in Law Enforcement Training in the Bahamas: Teacher-Centered to Learner-Centered

Directory of Open Access Journals (Sweden)

Hunter-Johnson, Yvonne

2012-10-01

Full Text Available This study focused on determining whether the learning preference of law enforcement officers in the Bahamas was either pedagogical (teacher-centered or andragogical (student-centered. Law enforcement personnel in a Bahamian police department were administered the Student Orientation Questionnaire (SOQ developed by Christian (1982. One hundred and sixty-eight individuals completed the SOQ. Chi square statistics were calculated on the variables of educational level and gender. The preferred learning orientation was primarily andragogical; those with higher education levels tended to have a higher andragogical orientation. There were no differences by gender. As a result of the findings, a three-step approach is proposed to transition the training environment from one that is teacher-centered to one that is learner-centered

PACS strategy for imaging centers.

Science.gov (United States)

Bedel, Victoria; Zdanowicz, Mark

2004-01-01

Picture archiving and communications systems (PACS) have been available in imaging centers for many years, but they often were less functional, were not well integrated into patient information systems, and lacked the network backbone to implement a system. As modalities are replaced and technology improves, the ability and time for an imaging center to acquire, integrate, and utilize PACS has arrived. However, each imaging center must determine why it should invest in PACS. A business plan is the fundamental need. Each imaging center must understand its target market, growth rate, and staffing plans. Additional considerations lie in current and future modality availability, the need for offsite delivery of images and reports, and the potential need for remote transmission of images. These issues must be identified and prioritized. A multidisciplinary team is essential. The most successful PACS implementation begins with complete involvement from all levels. The team should be comprised of people with complementary skills who are committed to a common purpose, set of performance goals, and approach for which they hold themselves mutually accountable. The team must jointly decide on the project's objectives. These objectives fall under 4 categories: clinical, service, financial, and performance. PACS must be considered a tool to help accomplish each objective. The imaging center must determine its top priorities, then translate them into a technology "wish list." The center can then list those pieces of technology that are most important and prioritize them. There are even more considerations for connecting multiple imaging centers. The team must create a comprehensive request for proposal (RFP) and determine the vendors that will receive the document. Once the RFP responses have been received and the vendor has been selected, an effective training plan must be executed. Training plans should be competency-based, ensuring comfort and competency among all staff. Upon

NASA's engineering research centers and interdisciplinary education

Science.gov (United States)

Johnston, Gordon I.

1990-01-01

A new program of interactive education between NASA and the academic community aims to improve research and education, provide long-term, stable funding, and support cross-disciplinary and multi-disciplinary research. The mission of NASA's Office of Aeronautics, Exploration and Technology (OAET) is discussed and it is pointed out that the OAET conducts about 10 percent of its total R&D program at U.S. universities. Other NASA university-based programs are listed including the Office of Commercial Programs Centers for the Commercial Development of Space (CCDS) and the National Space Grant program. The importance of university space engineering centers and the selection of the nine current centers are discussed. A detailed composite description is provided of the University Space Engineering Research Centers. Other specialized centers are described such as the Center for Space Construction, the Mars Mission Research Center, and the Center for Intelligent Robotic Systems for Space Exploration. Approaches to educational outreach are discussed.

Dialysis centers - what to expect

Science.gov (United States)

... kidneys - dialysis centers; Dialysis - what to expect; Renal replacement therapy - dialysis centers; End-stage renal disease - dialysis ... to a tube that connects to the dialysis machine. Your blood will flow through the tube, into ...

Center for Prostate Disease Research

Data.gov (United States)

Federal Laboratory Consortium — The Center for Prostate Disease Research is the only free-standing prostate cancer research center in the U.S. This 20,000 square foot state-of-the-art basic science...

National Center for Biotechnology Information

Science.gov (United States)

... to NCBI Sign Out NCBI National Center for Biotechnology Information Search database All Databases Assembly Biocollections BioProject ... Search Welcome to NCBI The National Center for Biotechnology Information advances science and health by providing access ...

Information on the Karlsruhe Nuclear Research Center

International Nuclear Information System (INIS)

Reuter, H.H.

1980-01-01

A short overview is given about the origins of Karlsruhe Nuclear Research Center. The historical development of the different companies operating the Center is shown. Because the original task assigned to the Center was the construction and testing of the first German reactor exclusively built by German companies, a detailed description of this reactor and the changes made afterwards is presented. Next, today's organizational structure of the Center is outlined and the development of the Center's financing since its foundation is shown. A short overview about the structure of employees from the Center's beginning up to now is also included as well as a short description of today's main activities. (orig.)

Italy INAF Data Center Report

Science.gov (United States)

Negusini, M.; Sarti, P.

2013-01-01

This report summarizes the activities of the Italian INAF VLBI Data Center. Our Data Center is located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the National Institute of Astrophysics.

Worldwide electricity used in data centers

International Nuclear Information System (INIS)

Koomey, Jonathan G

2008-01-01

The direct electricity used by data centers has become an important issue in recent years as demands for new Internet services (such as search, music downloads, video-on-demand, social networking, and telephony) have become more widespread. This study estimates historical electricity used by data centers worldwide and regionally on the basis of more detailed data than were available for previous assessments, including electricity used by servers, data center communications, and storage equipment. Aggregate electricity use for data centers doubled worldwide from 2000 to 2005. Three quarters of this growth was the result of growth in the number of the least expensive (volume) servers. Data center communications and storage equipment each contributed about 10% of the growth. Total electricity use grew at an average annual rate of 16.7% per year, with the Asia Pacific region (without Japan) being the only major world region with growth significantly exceeding that average. Direct electricity used by information technology equipment in data centers represented about 0.5% of total world electricity consumption in 2005. When electricity for cooling and power distribution is included, that figure is about 1%. Worldwide data center power demand in 2005 was equivalent (in capacity terms) to about seventeen 1000 MW power plants.

Worldwide electricity used in data centers

Science.gov (United States)

Koomey, Jonathan G.

2008-07-01

The direct electricity used by data centers has become an important issue in recent years as demands for new Internet services (such as search, music downloads, video-on-demand, social networking, and telephony) have become more widespread. This study estimates historical electricity used by data centers worldwide and regionally on the basis of more detailed data than were available for previous assessments, including electricity used by servers, data center communications, and storage equipment. Aggregate electricity use for data centers doubled worldwide from 2000 to 2005. Three quarters of this growth was the result of growth in the number of the least expensive (volume) servers. Data center communications and storage equipment each contributed about 10% of the growth. Total electricity use grew at an average annual rate of 16.7% per year, with the Asia Pacific region (without Japan) being the only major world region with growth significantly exceeding that average. Direct electricity used by information technology equipment in data centers represented about 0.5% of total world electricity consumption in 2005. When electricity for cooling and power distribution is included, that figure is about 1%. Worldwide data center power demand in 2005 was equivalent (in capacity terms) to about seventeen 1000 MW power plants.

PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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The Center for Aerospace Research: A NASA Center of Excellence at North Carolina Agricultural and Technical State University

Science.gov (United States)

Lai, Steven H.-Y.

1992-01-01

This report documents the efforts and outcomes of our research and educational programs at NASA-CORE in NCA&TSU. The goal of the center was to establish a quality aerospace research base and to develop an educational program to increase the participation of minority faculty and students in the areas of aerospace engineering. The major accomplishments of this center in the first year are summarized in terms of three different areas, namely, the center's research programs area, the center's educational programs area, and the center's management area. In the center's research programs area, we focus on developing capabilities needed to support the development of the aerospace plane and high speed civil transportation system technologies. In the educational programs area, we developed an aerospace engineering option program ready for university approval.

Center column design of the PLT

International Nuclear Information System (INIS)

Citrolo, J.; Frankenberg, J.

1975-01-01

The center column of the PLT machine is a secondary support member for the toroidal field coils. Its purpose is to decrease the bending moment at the nose of the coils. The center column design was to have been a stainless steel casting with the toroidal field coils grouped around the casting at installation, trapping it in place. However, the castings developed cracks during fabrication and were unsuitable for use. Installation of the coils proceeded without the center column. It then became necessary to redesign a center column which would be capable of installation with the toroidal field coils in place. The final design consists of three A-286 forgings. This paper discusses the final center column design and the influence that new knowledge, obtained during the power tests, had on the new design

PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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Oxygen Atom Transfer Using an Iron(IV)-Oxo Embedded in a Tetracyclic N-Heterocyclic Carbene System: How Does the Reactivity Compare to Cytochrome P450 Compound I?

Science.gov (United States)

Cantú Reinhard, Fabián G; de Visser, Sam P

2017-02-24

N-Heterocyclic carbenes (NHC) are commonly featured as ligands in transition metal catalysis. Recently, a cyclic system containing four NHC groups with a central iron atom was synthesized and its iron(IV)-oxo species, [Fe IV (O)(cNHC 4 )] 2+ , was characterized. This tetracyclic NHC ligand system may give the iron(IV)-oxo species unique catalytic properties as compared to traditional non-heme and heme iron ligand systems. Therefore, we performed a computational study on the structure and reactivity of the [Fe IV (O)(cNHC 4 )] 2+ complex in substrate hydroxylation and epoxidation reactions. The reactivity patterns are compared with cytochrome P450 Compound I and non-heme iron(IV)-oxo models and it is shown that the [Fe IV (O)(cNHC 4 )] 2+ system is an effective oxidant with oxidative power analogous to P450 Compound I. Unfortunately, in polar solvents, a solvent molecule will bind to the sixth ligand position and decrease the catalytic activity of the oxidant. A molecular orbital and valence bond analysis provides insight into the origin of the reactivity differences and makes predictions of how to further exploit these systems in chemical catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Omeprazole on Iron Absorption: Preliminary Study

Directory of Open Access Journals (Sweden)

Mahmut Yaşar Çeliker

2013-09-01

Full Text Available Objective: Increasing numbers of pediatric and adult patients are being treated with proton pump inhibitors (PPIs. PPIs are known to inhibit gastric acid secretion. Nonheme iron requires gastric acid for conversion to the ferrous form for absorption. Ninety percent of dietary and 100% of oral iron therapy is in the nonheme form. To the best of our knowledge, the effect of PPIs on iron absorption has not been studied in humans. Our study assessed the relationship between omeprazole therapy and iron absorption in healthy subjects. Materials and Methods: We recruited 9 healthy volunteers between June 2010 and March 2011. Subjects with chronic illness, anemia, or use of PPI therapy were excluded. Serum iron concentrations were measured 1, 2, and 3 h after the ingestion of iron (control group. The measurements were repeated on a subsequent visit after 4 daily oral administrations of omeprazole at a dose of 40 mg (treatment group. Results: One female and 8 male volunteers were enrolled in the study with a mean age of 33 years. There was no statistical difference detected between baseline, 1-h, 2-h, and 3-h iron levels between control and treatment groups. Conclusion: Administration of omeprazole for a short duration does not affect absorption of orally administered iron in healthy individuals.

The Poison Control Center--Its Role

Science.gov (United States)

Manoguerra, Anthony S.

1976-01-01

Poison Control Centers are being utilized by more schools of pharmacy each year as training sites for students. This paper discusses what such a center is, its services, changes anticipated in the poison center system in the next several years and how they may influence pharmacy education, specifically as it relates to clinical toxicology.…

Emergency Operations Center ribbon cutting

Science.gov (United States)

2009-01-01

Center Director Gene Goldman and special guests celebrate the opening of the site's new Emergency Operations Center on June 2. Participants included (l t r): Steven Cooper, deputy director of the National Weather Service Southern Region; Tom Luedtke, NASA associate administrator for institutions and management; Charles Scales, NASA associate deputy administrator; Mississippi Gov. Haley Barbour; Gene Goldman, director of Stennis Space Center; Jack Forsythe, NASA assistant administrator for the Office of Security and Program Protection; Dr. Richard Williams, NASA chief health and medical officer; and Weldon Starks, president of Starks Contracting Company Inc. of Biloxi.

PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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Are all spatial reference frames egocentric? Reinterpreting evidence for allocentric, object-centered, or world-centered reference frames

Directory of Open Access Journals (Sweden)

Flavia eFilimon

2015-12-01

Full Text Available The use and neural representation of egocentric spatial reference frames is well documented. In contrast, whether the brain represents spatial relationships between objects in allocentric, object-centered, or world-centered coordinates is debated. Here, I review behavioral, neuropsychological, neurophysiological (neuronal recording, and neuroimaging evidence for and against allocentric, object-centered, or world-centered spatial reference frames. Based on theoretical considerations, simulations, and empirical findings from spatial navigation, spatial judgments, and goal-directed movements, I suggest that all spatial representations may in fact be dependent on egocentric reference frames.

[NEURO-ONCOLOGY A NEW FIELD IN DAVIDOFF CANCER CENTER AT RABIN MEDICAL CENTER].

Science.gov (United States)

Yust-Katz, Shlomit; Limon, Dror; Abu-Shkara, Ramez; Siegal, Tali

2017-08-01

Neuro-oncology is a subspecialty attracting physicians from medical disciplines such as neurology, neurosurgery, pediatrics, oncology, and radiotherapy. It deals with diagnosis and management of primary brain tumors, as well as metastatic and non-metastatic neurological manifestations that frequently affect cancer patients including brain metastases, paraneoplastic syndromes and neurological complications of cancer treatment. A neuro-oncology unit was established in Davidoff Cancer Center at Rabin Medical Center. It provides a multidisciplinary team approach for management of brain tumors and services, such as expert outpatient clinics and inpatient consultations for the departments of oncology, hematology, bone marrow transplantation and other departments in the Rabin Medical Center. In addition, expert consultation is frequently provided to other hospitals that treat cancer patients with neurological manifestations. The medical disciplines that closely collaborate for the daily management of neuro-oncology patients include radiotherapy, hematology, oncology, neuro-surgery, neuro-radiology and neuro-pathology. The neuro-oncology center is also involved in clinical and laboratory research conducted in collaboration with researchers in Israel and abroad. The new service contributes substantially to the improved care of cancer patients and to the advance of research topics in the field of neuro-oncology.

PTSD: National Center for PTSD

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Universal centers in the cubic trigonometric Abel equation

Directory of Open Access Journals (Sweden)

Jaume Giné

2014-02-01

Full Text Available We study the center problem for the trigonometric Abel equation $d \\rho/ d \\theta= a_1 (\\theta \\rho^2 + a_2(\\theta \\rho^3,$ where $a_1(\\theta$ and $a_2(\\theta$ are cubic trigonometric polynomials in $\\theta$. This problem is closely connected with the classical Poincaré center problem for planar polynomial vector fields. A particular class of centers, the so-called universal centers or composition centers, is taken into account. An example of non-universal center and a characterization of all the universal centers for such equation are provided.

International Center for Gas Technology Information

International Nuclear Information System (INIS)

Gad, L.H.

1993-01-01

Based on an acknowledgement of the growing importance of natural gas, a number of European countries, USA, Japan and the Russian Federation have worked together in order to establish a common center of information on natural gas technology under the auspices of the International Energy Agency. Centers were to be established in Washington and in Denmark. The centers will concern themselves with establishing an international information center for gas technology, effecting natural gas technology transfer between global regions, carrying out analytical studies on the energy market and the development of technology within the field of natural gas. The structure of the decision-making processes that will be employed is explained in addition to the organization and economy. The centers should build up a global information network between the relevant countries, their gas companies, institutions etc. (AB)

Advertising by academic medical centers.

Science.gov (United States)

Larson, Robin J; Schwartz, Lisa M; Woloshin, Steven; Welch, H Gilbert

2005-03-28

Many academic medical centers have increased their use of advertising to attract patients. While the content of direct-to-consumer pharmaceutical advertisements (ads) has been studied, to our knowledge, advertising by academic medical centers has not. We aimed to characterize advertising by the nation's top academic medical centers. We contacted all 17 medical centers named to the US News & World Report 2002 honor roll of "America's Best Hospitals" for a semistructured interview regarding their advertising practices. In addition, we obtained and systematically analyzed all non-research-related print ads placed by these institutions in their 5 most widely circulating local newspapers during 2002. Of the 17 institutions, 16 reported advertising to attract patients; 1 stated, "We're just word of mouth." While all 17 centers confirmed the presence of an institutional review board process for approving advertising to attract research subjects, none reported a comparable process for advertising to attract patients. We identified 127 unique non-research-related print ads for the 17 institutions during 2002 (mean, 7.5; range, 0-39). Three ads promoted community events with institution sponsorship, 2 announced genuine public services, and 122 were aimed at attracting patients. Of the latter group, 36 ads (29.5%) promoted the medical center as a whole, while 65 (53.3%) promoted specific clinical departments and 21 (17.2%) promoted single therapeutic interventions or diagnostic tests. The most commonly used marketing strategies included appealing to emotions (61.5%), highlighting institution prestige (60.7%), mentioning a symptom or disease (53.3%), and promoting introductory lectures or special offers likely to lead to further business (47.5%). Of the 21 ads for single interventions, most were for unproved (38.1%) or cosmetic (28.6%) procedures. While more than half of these ads presented benefits, none quantified their positive claims and just 1 mentioned potential harms

Center for beam physics 1996-1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-02-01

The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center`s program include addressing R&D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R&D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R&D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997.

Acoustic Center or Time Origin?

DEFF Research Database (Denmark)

Staffeldt, Henrik

1999-01-01

The paper discusses the acoustic center in relation to measurements of loudspeaker polar data. Also, it presents the related concept time origin and discusses the deviation that appears between positions of the acoustic center found by wavefront based and time based measuring methods....

PTSD: National Center for PTSD

Science.gov (United States)

... Care » PTSD: National Center for PTSD » Public » Videos PTSD: National Center for PTSD Menu Menu PTSD PTSD Home For the Public ... Prescribing for PTSD, Know Your Options . × What is PTSD? Right Click here to download "What is PTSD?" ( ...

PTSD: National Center for PTSD

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The old is new again: asparagine oxidation in calcium-dependent antibiotic biosynthesis.

Science.gov (United States)

Worthington, Andrew S; Burkart, Michael D

2007-03-20

Non-ribosomal peptides are built from both proteinogenic and non-proteinogenic amino acids. The latter resemble amino acids but contain modifications not found in proteins. The recent characterization of a non-heme Fe(2+) and alpha-ketoglutarate-dependent oxygenase that stereospecifically generates beta-hydroxyasparagine, an unnatural amino acid building block for the biosynthesis of calcium-dependent antibiotic, a lipopeptide antibiotic. This work improves our understanding of how these non-proteinogenic amino acids are synthesized.

PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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PTSD: National Center for PTSD

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Carl Rogers: Body-Centered Counselor.

Science.gov (United States)

Fernald, Peter S.

2000-01-01

C. R. Rogers' approach is examined in the context of person-centered theories of personality and counseling. Identifies similarities between Rogers' thinking and W. Reich's theories in body-oriented psychotherapy. Discusses film-recorded interview conducted by Rogers, which demonstrates his body-centered approach. (Author/JDM)

Centers and homotopy centers in enriched monoidal categories

Czech Academy of Sciences Publication Activity Database

Batanin, M.; Markl, Martin

2012-01-01

Roč. 230, 4-6 (2012), s. 1811-1858 ISSN 0001-8708 R&D Projects: GA ČR GA201/08/0397 Institutional support: RVO:67985840 Keywords : monoidal categories * center * Hochschild complex Subject RIV: BA - General Mathematics Impact factor: 1.373, year: 2012 http://www.sciencedirect.com/science/article/pii/S0001870812001508

User-Centered Data Management

CERN Document Server

Catarci, Tiziana; Kimani, Stephen

2010-01-01

This lecture covers several core issues in user-centered data management, including how to design usable interfaces that suitably support database tasks, and relevant approaches to visual querying, information visualization, and visual data mining. Novel interaction paradigms, e.g., mobile and interfaces that go beyond the visual dimension, are also discussed. Table of Contents: Why User-Centered / The Early Days: Visual Query Systems / Beyond Querying / More Advanced Applications / Non-Visual Interfaces / Conclusions

Audio Visual Center

Data.gov (United States)

Federal Laboratory Consortium — The Audiovisual Services Center provides still photographic documentation with laboratory support, video documentation, video editing, video duplication, photo/video...

International nuclear service centers: a bibliography

International Nuclear Information System (INIS)

Petty, G.M.; Yokota, M.

1978-03-01

The literature relating specifically to international nuclear fuel service centers would appear to be relatively scarce, based on the results of searches of the Energy Data Base, the libraries of the University of California at Los Angeles, and The Rand Corporation, and other sources. Works specifically relating to international service centers are annotated in this bibliography. Also listed, without annotation, are studies of various kinds of multinational public enterprises. In addition, there are references to many of the studies of the one-nation nuclear energy center concept. Most of these resulted from the survey of possible sites for these centers mandated by the US Energy Reorganization Act of 1974

PTSD: National Center for PTSD

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Full Text Available skip to page content Attention A T users. To access the menus on this page please perform the following steps. 1. Please switch auto forms ... Conditions Continuing Education Publications List of Center Publications Articles by Center Staff Clinician’s Trauma Update PTSD Research ...

Elliptic genera from multi-centers

Energy Technology Data Exchange (ETDEWEB)

Gaddam, Nava [Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena,Utrecht University, 3508 TD Utrecht (Netherlands)

2016-05-13

I show how elliptic genera for various Calabi-Yau threefolds may be understood from supergravity localization using the quantization of the phase space of certain multi-center configurations. I present a simple procedure that allows for the enumeration of all multi-center configurations contributing to the polar sector of the elliptic genera — explicitly verifying this in the cases of the quintic in ℙ{sup 4}, the sextic in Wℙ{sub (2,1,1,1,1)}, the octic in Wℙ{sub (4,1,1,1,1)} and the dectic in Wℙ{sub (5,2,1,1,1)}. With an input of the corresponding ‘single-center’ indices (Donaldson-Thomas invariants), the polar terms have been known to determine the elliptic genera completely. I argue that this multi-center approach to the low-lying spectrum of the elliptic genera is a stepping stone towards an understanding of the exact microscopic states that contribute to supersymmetric single center black hole entropy in N=2 supergravity.

Single-center trials in neonatology: Issues to consider.

Science.gov (United States)

Sinha, Ian P; Sinha, Sunil K

2015-12-01

Single-center randomized controlled trials confer certain advantages over multi-center trials, in that they are cheaper and easier to design and conduct. However, recent research suggests that single-center trials are likely to overestimate treatment effects. There are notable examples in neonatology where results from multi-center trials have contradicted results of single-center studies. In this paper we discuss issues around external generalizability of single-center studies, and methodological issues that may cause bias. Copyright © 2015 Elsevier Ltd. All rights reserved.

Climate Prediction Center - Seasonal Outlook

Science.gov (United States)

Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Site Map News Forecast Discussion PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD INFLUENCE ON THE MONTHLY-AVERAGED CLIMATE. OUR MID-MONTH ASSESSMENT OF LOW-FREQUENCY CLIMATE VARIABILITY IS

Head Start Center Design Guide.

Science.gov (United States)

Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

This guide contains suggested criteria for planning, designing, and renovating Head Start centers so that they are safe, child-oriented, developmentally appropriate, beautiful, environmentally sensitive, and functional. The content is based on the U.S. General Services Administration's Child Care Center Design Guide, PBS-P140, which was intended…

Palliative care content on cancer center websites.

Science.gov (United States)

Vater, Laura B; Rebesco, Gina; Schenker, Yael; Torke, Alexia M; Gramelspacher, Gregory

2018-03-01

Professional guidelines recommend that palliative care begin early in advanced cancer management, yet integration of palliative and cancer care remains suboptimal. Cancer centers may miss opportunities to provide palliative care information online. In this study, we described the palliative care content on cancer center websites. We conducted a systematic content analysis of 62 National Cancer Institute- (NCI) designated cancer center websites. We assessed the content of center homepages and analyzed search results using the terms palliative care, supportive care, and hospice. For palliative and supportive care webpages, we assessed services offered and language used to describe care. Two researchers analyzed all websites using a standardized coding manual. Kappa values ranged from 0.78 to 1. NCI-designated cancer center homepages presented information about cancer-directed therapy (61%) more frequently than palliative care (5%). Ten percent of cancer centers had no webpage with palliative care information for patients. Among centers with information for patients, the majority (96%) defined palliative or supportive care, but 30% did not discuss delivery of palliative care alongside curative treatment, and 14% did not mention provision of care early in the disease process. Cancer center homepages rarely mention palliative care services. While the majority of centers have webpages with palliative care content, they sometimes omit information about early use of care. Improving accessibility of palliative care information and increasing emphasis on early provision of services may improve integration of palliative and cancer care.

Environmental Modeling Center

Data.gov (United States)

Federal Laboratory Consortium — The Environmental Modeling Center provides the computational tools to perform geostatistical analysis, to model ground water and atmospheric releases for comparison...

SRTR center-specific reporting tools: Posttransplant outcomes.

Science.gov (United States)

Dickinson, D M; Shearon, T H; O'Keefe, J; Wong, H-H; Berg, C L; Rosendale, J D; Delmonico, F L; Webb, R L; Wolfe, R A

2006-01-01

Measuring and monitoring performance--be it waiting list and posttransplant outcomes by a transplant center, or organ donation success by an organ procurement organization and its partnering hospitals--is an important component of ensuring good care for people with end-stage organ failure. Many parties have an interest in examining these outcomes, from patients and their families to payers such as insurance companies or the Centers for Medicare and Medicaid Services; from primary caregivers providing patient counseling to government agencies charged with protecting patients. The Scientific Registry of Transplant Recipients produces regular, public reports on the performance of transplant centers and organ procurement organizations. This article explains the statistical tools used to prepare these reports, with a focus on graft survival and patient survival rates of transplant centers--especially the methods used to fairly and usefully compare outcomes of centers that serve different populations. The article concludes with a practical application of these statistics--their use in screening transplant center performance to identify centers that may need remedial action by the OPTN/UNOS Membership and Professional Standards Committee.

The EPRI NDE center after five years

International Nuclear Information System (INIS)

Dau, G.J.; Nemzek, T.A.

1985-01-01

In 1979, the Electric Power Research Institute (EPRI) established a Nondestructive Evaluation (NDE) Center. The purpose of the Center is to provide the electric utility industry with a dedicated NDE development and field-use-qualification capability. Later, the scope of activities at the NDE Center was expanded. Beginning in 1980, the BWR Owners Group (IGSCC) provided funding necessary to operate the BWR Pipe Remedy Demonstration and Training Facility. In 1984, the Maintenance Equipment Applications Center was established by EPRI. Both functions are co-located within the NDE Center. All three functions share common objectives of providing the electric utility industry with a capability dedicated to assuring reduction to practice of new or improved technology, proof testing, qualification for field use, and obtaining code and regulatory acceptance of qualified methods and training. The purpose of this paper is to describe typical activities of the Center and some of the benefits that have accrued. The next section describes the Center organization, operation, and facility, while the remaining sections discuss the technology transfer thrust and benefits

Planning for the Mercy Center for Breast Health.

Science.gov (United States)

Olivares, V Ed

2002-01-01

During the last months of 2000, administrators at the Mercy San Juan Medical Center in Carmichael, Calif., convened a steering committee to plan the Mercy Center for Breast Health. The Steering Committee was composed of the director of ancillary and support services, the oncology clinical nurse specialist, the RN manager of the oncology nursing unit, the RN surgery center manager, and me, the manager of imaging services. The committee was responsible for creating a new business with five specific objectives: to position the Center as a comprehensive diagnostic and resource center for women; to generate physician referrals to the Breast Center through various vehicles; to create awareness of the Breast Center's capabilities among area radiologists; to create awareness of the Breast Center among employees of six sister facilities; to create "brand awareness" for the Mercy Center for Breast Health among referring physicians and patients who could use competing centers in the area. The Steering Committee's charter was to design a center with a feminine touch and ambience and to provide a "one-stop shopping" experience for patients. A major component of the Breast Center is the Dianne Haselwood Resource Center, which provides patients with educational support and information. The Steering Committee brought its diverse experience and interests to bear on arranging for equipment acquisition, information and clerical systems, staffing, clinic office design, patient care and marketing. Planning the Mercy Center for Breast Health has been a positive challenge that brought together many elements of the organization and people from different departments and specialties to create a new business venture. Our charge now is to grow and to live up to our vision of offering complete breast diagnostic, education and support services in one location.

Emergency control centers for nuclear power plants

International Nuclear Information System (INIS)

Anon.

1979-01-01

Guidance is provided for the development and implementation of emergency control centers for nuclear power plants, including nuclear plant control room, nuclear plant company headquarters, emergency control center, and nuclear plant alternate emergency control center. Requirements and recommendations are presented for the mission, communications, instrumentation and equipment associated with each type of control center. Decisional aids, manning requirements and resources are also given; the decision aids cover both the accident assessment and protective action areas. Both normal and alternate means of communications are considered. Off-site emergency control centers, although not covered in the strict sense by this standard, are considered in an appendix

Thermal behavior of organic free radicals in γ-ray irradiated pepper studied by electron spin resonance spectroscopy

International Nuclear Information System (INIS)

Ichii, Akane; Abe, Aika; Ukai, Mitsuko

2003-01-01

Using electron spin resonance (ESR) spectroscopy, we revealed heating effects on irradiated pepper. The representative ESR spectrum of the irradiated pepper is consisted of four components a sextet centered at g=2.0, a singlet at the same g-value, a singlet at g=4.0 and side peaks near g=2.0. The first one is attributable to a signal with hyperfine (hf) interactions of Mn 2+ (hf constant=7.4 mT). The second one is due to an organic free radical that is induced by the γ-ray irradiation. The third one may originated from Fe 3+ in the nonhem proteins. The fourth signal was found at the symmetric positions of the organic free radical, i.e., the second signal. Upon heating, the forth signals decreased monotonicaly. The ESR signal of the pepper heated for more than 10 min was essentially the same as that before the irradiation. On the other hand, the second signal increased and then leveled off at a constant value by further heating. This is indicative the occurrence of some biochemical reactions such as Maillard reaction during heating procedures. (author)

Probes of the catalytic site of cysteine dioxygenase.

Science.gov (United States)

Chai, Sergio C; Bruyere, John R; Maroney, Michael J

2006-06-09

The first major step of cysteine catabolism, the oxidation of cysteine to cysteine sulfinic acid, is catalyzed by cysteine dioxygenase (CDO). In the present work, we utilize recombinant rat liver CDO and cysteine derivatives to elucidate structural parameters involved in substrate recognition and x-ray absorption spectroscopy to probe the interaction of the active site iron center with cysteine. Kinetic studies using cysteine structural analogs show that most are inhibitors and that a terminal functional group bearing a negative charge (e.g. a carboxylate) is required for binding. The substrate-binding site has no stringent restrictions with respect to the size of the amino acid. Lack of the amino or carboxyl groups at the alpha-carbon does not prevent the molecules from interacting with the active site. In fact, cysteamine is shown to be a potent activator of the enzyme without being a substrate. CDO was also rendered inactive upon complexation with the metal-binding inhibitors azide and cyanide. Unlike many non-heme iron dioxygenases that employ alpha-keto acids as cofactors, CDO was shown to be the only dioxygenase known to be inhibited by alpha-ketoglutarate.

Nitrite and nitroso compounds can serve as specific catalase inhibitors.

Science.gov (United States)

Titov, Vladimir Yu; Osipov, Anatoly N

2017-03-01

We present evidence that nitrite and nitrosothiols, nitrosoamines and non-heme dinitrosyl iron complexes can reversibly inhibit catalase with equal effectiveness. Catalase activity was evaluated by the permanganatometric and calorimetric assays. This inhibition is not the result of chemical transformations of these compounds to a single inhibitor, as well as it is not the result of NO release from these substances (as NO traps have no effect on the extent of inhibition). It was found that chloride and bromide in concentration above 80 mM and thiocyanate in concentration above 20 μM enhance catalase inhibition by nitrite and the nitroso compounds more than 100 times. The inhibition degree in this case is comparable with that induced by azide. We propose that the direct catalase inhibitor is a positively charged NO-group. This group acquires a positive charge in the active center of enzyme by interaction of nitrite or nitroso compounds with some enzyme groups. Halides and thiocyanate protect the NO + group from hydration and thus increase its inhibition effect. It is probable that a comparatively low chloride concentration in many cells is the main factor to protect catalase from inhibition by nitrite and nitroso compounds.

Comparison of CDE data in phacoemulsification between an open hospital-based ambulatory surgical center and a free-standing ambulatory surgical center

Directory of Open Access Journals (Sweden)

Ming Chen

2010-11-01

Full Text Available Ming Chen1, Mindy Chen21University of Hawaii, Honolulu, HI, USA; 2University of California, Irvine, CA, USAAbstract: Mean CDE (cumulative dissipated energy values were compared for an open hospital-based surgical center and a free-standing surgical center. The same model of phacoemulsifier (Alcon Infiniti Ozil was used. Mean CDE values showed that surgeons (individual private practice at the free-standing surgical center were more efficient than surgeons (individual private practice at the open hospital-based surgical center (mean CDE at the hospital-based surgical center 18.96 seconds [SD = 12.51]; mean CDE at the free-standing surgical center 13.2 seconds [SD = 9.5]. CDE can be used to monitor the efficiency of a cataract surgeon and surgical center in phacoemulsification. The CDE value may be used by institutions as one of the indicators for quality control and audit in phacoemulsification.Keywords: CDE (cumulative dissipated energy, open hospital-based ambulatory surgical center, free-standing surgical center, phacoemulsification 

Euclidean supergravity and multi-centered solutions

Directory of Open Access Journals (Sweden)

W.A. Sabra

2017-04-01

Full Text Available In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein–Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D=5, N=2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein–Maxwell multi-centered solutions are also presented.

Alternative Fuels Data Center: Biodiesel Equipment Options

Science.gov (United States)

Equipment Options to someone by E-mail Share Alternative Fuels Data Center: Biodiesel Equipment Options on Facebook Tweet about Alternative Fuels Data Center: Biodiesel Equipment Options on Twitter Bookmark Alternative Fuels Data Center: Biodiesel Equipment Options on Google Bookmark Alternative Fuels

Advanced Simulation Center

Data.gov (United States)

Federal Laboratory Consortium — The Advanced Simulation Center consists of 10 individual facilities which provide missile and submunition hardware-in-the-loop simulation capabilities. The following...

Student-Centered Coaching: The Moves

Science.gov (United States)

Sweeney, Diane; Harris, Leanna S.

2017-01-01

Student-centered coaching is a highly-effective, evidence-based coaching model that shifts the focus from "fixing" teachers to collaborating with them to design instruction that targets student outcomes. But what does this look like in practice? "Student-Centered Coaching: The Moves" shows you the day-to-day coaching moves that…

Agriculture: About EPA's National Agriculture Center

Science.gov (United States)

EPA's National Agriculture Center (Ag Center), with the support of the United States Department of Agriculture, serves growers, livestock producers, other agribusinesses, and agricultural information/education providers.

VT Designated New Town Center Boundary

Data.gov (United States)

Vermont Center for Geographic Information — Municipalities that lack a historic downtown may obtain New Town Center designation, meeting requirements for planning, capital expenditures, and regulatory tools...

Improving Productivity via QWL Centers.

Science.gov (United States)

Bentley, Marion T.; Hansen, Gary B.

1980-01-01

Gives a brief history of productivity improvement legislation in the United States and of the development and demise of the National Center for Productivity and Quality of Working Life (QWL). Describes existing productivity and QWL centers, including their locations, scope, services, and activities, and urges greater support at the federal level.…

Patient-centered medical home model: do school-based health centers fit the model?

Science.gov (United States)

Larson, Satu A; Chapman, Susan A

2013-01-01

School-based health centers (SBHCs) are an important component of health care reform. The SBHC model of care offers accessible, continuous, comprehensive, family-centered, coordinated, and compassionate care to infants, children, and adolescents. These same elements comprise the patient-centered medical home (PCMH) model of care being promoted by the Affordable Care Act with the hope of lowering health care costs by rewarding clinicians for primary care services. PCMH survey tools have been developed to help payers determine whether a clinician/site serves as a PCMH. Our concern is that current survey tools will be unable to capture how a SBHC may provide a medical home and therefore be denied needed funding. This article describes how SBHCs might meet the requirements of one PCMH tool. SBHC stakeholders need to advocate for the creation or modification of existing survey tools that allow the unique characteristics of SBHCs to qualify as PCMHs.

Economic viability of geriatric hip fracture centers.

Science.gov (United States)

Clement, R Carter; Ahn, Jaimo; Mehta, Samir; Bernstein, Joseph

2013-12-01

Management of geriatric hip fractures in a protocol-driven center can improve outcomes and reduce costs. Nonetheless, this approach has not spread as broadly as the effectiveness data would imply. One possible explanation is that operating such a center is not perceived as financially worthwhile. To assess the economic viability of dedicated hip fracture centers, the authors built a financial model to estimate profit as a function of costs, reimbursement, and patient volume in 3 settings: an average US hip fracture program, a highly efficient center, and an academic hospital without a specific hip fracture program. Results were tested with sensitivity analysis. A local market analysis was conducted to assess the feasibility of supporting profitable hip fracture centers. The results demonstrate that hip fracture treatment only becomes profitable when the annual caseload exceeds approximately 72, assuming costs characteristic of a typical US hip fracture program. The threshold of profitability is 49 cases per year for high-efficiency hip fracture centers and 151 for the urban academic hospital under review. The largest determinant of profit is reimbursement, followed by costs and volume. In the authors’ home market, 168 hospitals offer hip fracture care, yet 85% fall below the 72-case threshold. Hip fracture centers can be highly profitable through low costs and, especially, high revenues. However, most hospitals likely lose money by offering hip fracture care due to inadequate volume. Thus, both large and small facilities would benefit financially from the consolidation of hip fracture care at dedicated hip fracture centers. Typical US cities have adequate volume to support several such centers.

Birthing Centers and Hospital Maternity Services

Science.gov (United States)

... Educators Search English Español Birthing Centers and Hospital Maternity Services KidsHealth / For Parents / Birthing Centers and Hospital Maternity Services What's in this article? Giving Birth at ...

Understanding wellness center loyalty through lifestyle analysis.

Science.gov (United States)

Suresh, Satya; Ravichandran, Swathi; P, Ganesan

2011-01-01

Many changes taking place at a macro-level in Indian society along with the popularity of services that are native to India, such as Yoga and Ayurveda, have generated significant interest in wellness services. To assist wellness centers in gaining loyal clients, the goal of this study was to understand the influence of customer lifestyle factors on wellness center loyalty. The activities, interests, and opinions model was used to understand the lifestyles of wellness center clients. Data were collected from clients of five wellness centers. Regression results indicate that overworked individuals and those seeking a balance between work and family life would be the most loyal to wellness centers. Managerial implications of results are discussed.

Mailman Segal Center for Human Development | NSU

Science.gov (United States)

rendition of the National Anthem sung by Jonathan Richard, a young man with an autism spectrum disorder (ASD Dean Jim & Jan Moran Family Center Village Collaborations Early Learning Programs About Early Learning Programs Family Center Preschool About Our Preschool Enrollment Family Center Infant & Toddler

Clean Energy Solutions Center Services (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2014-04-01

The Clean Energy Solutions Center (Solutions Center) helps governments, advisors and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center partners with international organizations to provide online training, expert assistance, and technical resources on clean energy policy.

Energy Frontier Research Center, Center for Materials Science of Nuclear Fuels

International Nuclear Information System (INIS)

Allen, Todd R.

2011-01-01

The Office of Science, Basic Energy Sciences, has funded the INL as one of the Energy Frontier Research Centers in the area of material science of nuclear fuels. This document is the required annual report to the Office of Science that outlines the accomplishments for the period of May 2010 through April 2011. The aim of the Center for Material Science of Nuclear Fuels (CMSNF) is to establish the foundation for predictive understanding of the effects of irradiation-induced defects on thermal transport in oxide nuclear fuels. The science driver of the center's investigation is to understand how complex defect and microstructures affect phonon mediated thermal transport in UO2, and achieve this understanding for the particular case of irradiation-induced defects and microstructures. The center's research thus includes modeling and measurement of thermal transport in oxide fuels with different levels of impurities, lattice disorder and irradiation-induced microstructure, as well as theoretical and experimental investigation of the evolution of disorder, stoichiometry and microstructure in nuclear fuel under irradiation. With the premise that thermal transport in irradiated UO2 is a phonon-mediated energy transport process in a crystalline material with defects and microstructure, a step-by-step approach will be utilized to understand the effects of types of defects and microstructures on the collective phonon dynamics in irradiated UO2. Our efforts under the thermal transport thrust involved both measurement of diffusive phonon transport (an approach that integrates over the entire phonon spectrum) and spectroscopic measurements of phonon attenuation/lifetime and phonon dispersion. Our distinct experimental efforts dovetail with our modeling effort involving atomistic simulation of phonon transport and prediction of lattice thermal conductivity using the Boltzmann transport framework.

Industrial Assessment Center (IAC) Operations Manual

Energy Technology Data Exchange (ETDEWEB)

Gopalakrishnan, Bhaskaran [West Virginia Univ., Morgantown, WV (United States); Nimbalkar, Sachin U. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wenning, Thomas J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thirumaran, Kiran [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-04-01

IAC Operations Manual describes organizational model and operations of the Industrial Assessment Center (IAC), Center management activities, typical process of energy assessment, and energy assessment data for specific industry sectors.

Remote Sensing/Geographic Information Systems Center

Data.gov (United States)

Federal Laboratory Consortium — The RS/GIS Center, located at ERDC's Cold Regions Research and Engineering Laboratory, in Hanover, New Hampshire, is the Corps of Engineers Center of Expertise for...

Motivation to volunteer among senior center participants.

Science.gov (United States)

Pardasani, Manoj

2018-04-01

Senior centers in the United States play a vital role in the aging continuum of care as the focal points of a community-based system of services targeting independent older adults to promote their social integration and civically engagement. Although several studies have evaluated the diversity of senior center programs, demographic characteristics of participants, and benefits of participation, very few have explored motivations to volunteer among participants. Many senior centers rely on a cadre of participants who volunteer there to assist with programs and meal services. However, a systematic examination of volunteering interests and the rationale for volunteering among senior center participants has been missing from the literature. This mixed-methods study, conducted at a large suburban senior center, explores the interests and motivations of volunteerism among the participants. The study found that there was limited interest in volunteering among senior center participants. Those who were motivated to volunteer wanted to do so in order to stay connected with their community. There was strong interest in volunteering for single events or projects rather than a long-term commitment. Implications for senior centers are discussed.

Centralized Outpatient Education Center for Patients with Diabetes at Walter Reed Army Medical Center

Science.gov (United States)

1984-05-16

rated into the study where appropriate. Interviews with education coordinators from nonmilitary diabetes treatment facilities were evaluated and...personnel were evaluated to determine the acceptance of the concept of an outpatient education center for diabetic patients. 12 The data from the...step was to evaluate the data from 100 outpatients to ascertain the degree of acceptance of an outpatient education center for diabetic patients. The

Viewer-centered and body-centered frames of reference in direct visuomotor transformations.

Science.gov (United States)

Carrozzo, M; McIntyre, J; Zago, M; Lacquaniti, F

1999-11-01

It has been hypothesized that the end-point position of reaching may be specified in an egocentric frame of reference. In most previous studies, however, reaching was toward a memorized target, rather than an actual target. Thus, the role played by sensorimotor transformation could not be disassociated from the role played by storage in short-term memory. In the present study the direct process of sensorimotor transformation was investigated in reaching toward continuously visible targets that need not be stored in memory. A virtual reality system was used to present visual targets in different three-dimensional (3D) locations in two different tasks, one with visual feedback of the hand and arm position (Seen Hand) and the other without such feedback (Unseen Hand). In the Seen Hand task, the axes of maximum variability and of maximum contraction converge toward the mid-point between the eyes. In the Unseen Hand task only the maximum contraction correlates with the sight-line and the axes of maximum variability are not viewer-centered but rotate anti-clockwise around the body and the effector arm during the move from the right to the left workspace. The bulk of findings from these and previous experiments support the hypothesis of a two-stage process, with a gradual transformation from viewer-centered to body-centered and arm-centered coordinates. Retinal, extra-retinal and arm-related signals appear to be progressively combined in superior and inferior parietal areas, giving rise to egocentric representations of the end-point position of reaching.

Alternative Fuels Data Center: Natural Gas Vehicles

Science.gov (United States)

Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas Vehicles to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Vehicles on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Vehicles on Twitter Bookmark Alternative

EPA Center for Corporate Climate Leadership

Science.gov (United States)

EPA's Center for Corporate Climate Leadership is a comprehensive resource to help organizations measure & manage GHG emissions. The Center provides technical tools, educational resources, opportunities for information sharing & highlights best practices.

Characterizing customers at medical center farmers' markets.

Science.gov (United States)

Kraschnewski, Jennifer L; George, Daniel R; Rovniak, Liza S; Monroe, Diana L; Fiordalis, Elizabeth; Bates, Erica

2014-08-01

Approximately 100 farmers' markets operate on medical center campuses. Although these venues can uniquely serve community health needs, little is known about customer characteristics and outreach efforts. Intercept survey of markets and market customers between August 2010 and October 2011 at three medical centers in different geographic regions of the US (Duke University Medical Center, Cleveland Clinic, and Penn State Hershey Medical Center) were conducted. Markets reported serving 180-2,000 customers per week and conducting preventive medicine education sessions and community health programs. Customers (n = 585) across markets were similar in sociodemographic characteristics--most were middle-aged, white, and female, who were employees of their respective medical center. Health behaviors of customers were similar to national data. The surveyed medical center farmers' markets currently serve mostly employees; however, markets have significant potential for community outreach efforts in preventive medicine. If farmers' markets can broaden their reach to more diverse populations, they may play an important role in contributing to community health.

Academic Medical Centers as digital health catalysts.

Science.gov (United States)

DePasse, Jacqueline W; Chen, Connie E; Sawyer, Aenor; Jethwani, Kamal; Sim, Ida

2014-09-01

Emerging digital technologies offer enormous potential to improve quality, reduce cost, and increase patient-centeredness in healthcare. Academic Medical Centers (AMCs) play a key role in advancing medical care through cutting-edge medical research, yet traditional models for invention, validation and commercialization at AMCs have been designed around biomedical initiatives, and are less well suited for new digital health technologies. Recently, two large bi-coastal Academic Medical Centers, the University of California, San Francisco (UCSF) through the Center for Digital Health Innovation (CDHI) and Partners Healthcare through the Center for Connected Health (CCH) have launched centers focused on digital health innovation. These centers show great promise but are also subject to significant financial, organizational, and visionary challenges. We explore these AMC initiatives, which share the following characteristics: a focus on academic research methodology; integration of digital technology in educational programming; evolving models to support "clinician innovators"; strategic academic-industry collaboration and emergence of novel revenue models. Copyright © 2014 Elsevier Inc. All rights reserved.

Building the Teraflops/Petabytes Production Computing Center

International Nuclear Information System (INIS)

Kramer, William T.C.; Lucas, Don; Simon, Horst D.

1999-01-01

In just one decade, the 1990s, supercomputer centers have undergone two fundamental transitions which require rethinking their operation and their role in high performance computing. The first transition in the early to mid-1990s resulted from a technology change in high performance computing architecture. Highly parallel distributed memory machines built from commodity parts increased the operational complexity of the supercomputer center, and required the introduction of intellectual services as equally important components of the center. The second transition is happening in the late 1990s as centers are introducing loosely coupled clusters of SMPs as their premier high performance computing platforms, while dealing with an ever-increasing volume of data. In addition, increasing network bandwidth enables new modes of use of a supercomputer center, in particular, computational grid applications. In this paper we describe what steps NERSC is taking to address these issues and stay at the leading edge of supercomputing centers.; N

Comparison of CDE data in phacoemulsification between an open hospital-based ambulatory surgical center and a free-standing ambulatory surgical center.

Science.gov (United States)

Chen, Ming; Chen, Mindy

2010-11-12

Mean CDE (cumulative dissipated energy) values were compared for an open hospital- based surgical center and a free-standing surgical center. The same model of phacoemulsifier (Alcon Infiniti Ozil) was used. Mean CDE values showed that surgeons (individual private practice) at the free-standing surgical center were more efficient than surgeons (individual private practice) at the open hospital-based surgical center (mean CDE at the hospital-based surgical center 18.96 seconds [SD = 12.51]; mean CDE at the free-standing surgical center 13.2 seconds [SD = 9.5]). CDE can be used to monitor the efficiency of a cataract surgeon and surgical center in phacoemulsification. The CDE value may be used by institutions as one of the indicators for quality control and audit in phacoemulsification.

M-center growth in alkali halides: computer simulation

International Nuclear Information System (INIS)

Aguilar, M.; Jaque, F.; Agullo-Lopez, F.

1983-01-01

The heterogeneous interstitial nucleation model previously proposed to explain F-center growth curves in irradiated alkali halides has been extended to account for M-center kinetics. The interstitials produced during the primary irradiation event are assumed to be trapped at impurities and interstitial clusters or recombine with F and M centers. For M-center formation two cases have been considered: (a) diffusion and aggregation of F centers, and (b) statistical generation and pairing of F centers. Process (b) is the only one consistent with the quadratic relationship between M and F center concentrations. However, to account for the F/M ratios experimentally observed as well as for the role of dose-rate, a modified statistical model involving random creation and association of F + -F pairs has been shown to be adequate. (author)

Benefits Analysis of Multi-Center Dynamic Weather Routes

Science.gov (United States)

Sheth, Kapil; McNally, David; Morando, Alexander; Clymer, Alexis; Lock, Jennifer; Petersen, Julien

2014-01-01

Dynamic weather routes are flight plan corrections that can provide airborne flights more than user-specified minutes of flying-time savings, compared to their current flight plan. These routes are computed from the aircraft's current location to a flight plan fix downstream (within a predefined limit region), while avoiding forecasted convective weather regions. The Dynamic Weather Routes automation has been continuously running with live air traffic data for a field evaluation at the American Airlines Integrated Operations Center in Fort Worth, TX since July 31, 2012, where flights within the Fort Worth Air Route Traffic Control Center are evaluated for time savings. This paper extends the methodology to all Centers in United States and presents benefits analysis of Dynamic Weather Routes automation, if it was implemented in multiple airspace Centers individually and concurrently. The current computation of dynamic weather routes requires a limit rectangle so that a downstream capture fix can be selected, preventing very large route changes spanning several Centers. In this paper, first, a method of computing a limit polygon (as opposed to a rectangle used for Fort Worth Center) is described for each of the 20 Centers in the National Airspace System. The Future ATM Concepts Evaluation Tool, a nationwide simulation and analysis tool, is used for this purpose. After a comparison of results with the Center-based Dynamic Weather Routes automation in Fort Worth Center, results are presented for 11 Centers in the contiguous United States. These Centers are generally most impacted by convective weather. A breakdown of individual Center and airline savings is presented and the results indicate an overall average savings of about 10 minutes of flying time are obtained per flight.

Center Innovation Fund: AFRC CIF Program

Data.gov (United States)

National Aeronautics and Space Administration — The Armstrong Flight Research Center is NASA’s primary center for atmospheric flight research and operations, with a vision “to fly what others only...

Radiation color and electron-hole centers of serpentines

International Nuclear Information System (INIS)

Lyutoev, V.P.; Yukhtanov, P.P.

1999-01-01

Radiation-induced coloring of serpentine (Mg 3 [Si 2 O 5 ](OH) 4 ), gamma radiation dose being 30 Mrad, is studied by the ESR and absorption spectroscopy methods. It is ascertained that ionizing radiation gives rise to formation of radiation centers on the mineral basic structural elements. paramagnetic centers and coloring centers, relating to radiation centers, stem from the same type of defects - O - oxygen centers, formed as a result of radiation-induced break of OH-bonds [ru

The Invention and Institutionalization of Volunteer Centers

DEFF Research Database (Denmark)

Lorentzen, Håkon; Henriksen, Lars Skov

2014-01-01

the Norwegian centers lacked a national coordinating unit. Third, an independent legal form in which local associations are members may have helped Danish centers bring about a sense of local ownership. In Norway, volunteer centers had weak ties to other local voluntary associations and were at times perceived...

Heart Information Center

Science.gov (United States)

... Rounds Seminar Series & Daily Conferences Fellowships and Residencies School of Perfusion Technology Education Resources Library & Learning Resource Center CME Resources THI Journal THI Cardiac Society Register for the Cardiac Society ...

HUD Homeownership Centers

Data.gov (United States)

Department of Housing and Urban Development — HUD Homeownership Centers (HOCs) insure single family Federal Housing Administration (FHA) mortgages and oversee the selling of HUD homes. FHA has four Homeownership...

14 CFR 29.27 - Center of gravity limits.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Center of gravity limits. 29.27 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.27 Center of gravity limits. The extreme forward and aft centers of gravity and, where critical, the extreme lateral centers of gravity...

Clinical quality performance in U.S. health centers.

Science.gov (United States)

Shi, Leiyu; Lebrun, Lydie A; Zhu, Jinsheng; Hayashi, Arthur S; Sharma, Ravi; Daly, Charles A; Sripipatana, Alek; Ngo-Metzger, Quyen

2012-12-01

To describe current clinical quality among the nation's community health centers and to examine health center characteristics associated with performance excellence. National data from the 2009 Uniform Data System. Health centers reviewed patient records and reported aggregate data to the Uniform Data System. Six measures were examined: first-trimester prenatal care, childhood immunization completion, Pap tests, low birth weight, controlled hypertension, and controlled diabetes. The top 25 percent performing centers were compared with lower performing (bottom 75 percent) centers on these measures. Logistic regressions were utilized to assess the impact of patient, provider, and institutional characteristics on health center performance. Clinical care and outcomes among health centers were generally comparable to national averages. For instance, 67 percent of pregnant patients received timely prenatal care (national = 68 percent), 69 percent of children achieved immunization completion (national = 67 percent), and 63 percent of hypertensive patients had blood pressure under control (national = 48 percent). Depending on the measure, centers with more uninsured patients were less likely to do well, while centers with more physicians and enabling service providers were more likely to do well. Health centers provide quality care at rates comparable to national averages. Performance may be improved by increasing insurance coverage among patients and increasing the ratios of physicians and enabling service providers to patients. © Health Research and Educational Trust.

INIS National Center in Syria

International Nuclear Information System (INIS)

Al-Hallack, R.

2006-01-01

International Nuclear Information System (INIS) is the world's leading information system on the peaceful uses of nuclear science and technology and it is operated by the International Atomic Energy Agency (IAEA) in Vienna, Austria. An overview of INIS products, services, philosophy and operation is given. INIS hold a database containing over 2.5 million references increasing at approximately 85,000 references per year and a collection of full text non-conventional, or grey literature that would be hard to obtain elsewhere. In addition, the PC-based software for inputs preparation (WinFIBRE) is demonstrated. INIS national center in Syria is considered as a regional center for INIS inputs preparation. The center is responsible for selecting the relevant nuclear literature produced and published in Syria and preparing the national inputs and send them to INIS Secretariat to be included in the INIS database. The center also provides INIS services and products to users within Syria. Availability of INIS Database on CD-ROMs, which updated monthly, and the internet version, which updated weekly, and the NCL collections are also presented. Finally, translation activity of the center, such as INIS Booklet entitled Presenting INIS, and the INIS Thesaurus into Arabic were mentioned. This was an in-kind contribution from the Atomic Energy Commission of Syria to support the valuable work of the INIS and Nuclear Knowledge Management (NKM) section and will contribute significantly the dissemination of information among the researchers and scientists in the Arab Countries. (author)

Academic Specialization and Contemporary University Humanities Centers

Science.gov (United States)

Brownley, Martine W.

2012-01-01

Given the academic specialization endemic today in humanities disciplines, some of the most important work of humanities centers has become promoting education about the humanities in general. After charting the rise of humanities centers in the US, three characteristics of centers that enable their advancement of larger concerns of the humanities…

Une maison de culture (A Culture Center).

Science.gov (United States)

Mourlevat, Alain

1980-01-01

Describes the "Culture Center" designed by Le Corbusier and located in Firminy, France. The role of the center in arousing intellectual curiosity in people living in a technological age is discussed. The audience of this culture center, young people, and the types of activities directed toward them are described. (AMH)

14 CFR 27.27 - Center of gravity limits.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Center of gravity limits. 27.27 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.27 Center of gravity limits. The extreme forward and aft centers of gravity and, where critical, the extreme lateral centers of gravity must be...

New Mexico Museums and Cultural Centers

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of museums and cultural centers in New Mexico, in point form, with limited attributes, compiled using...

Lunar phases and crisis center telephone calls.

Science.gov (United States)

Wilson, J E; Tobacyk, J J

1990-02-01

The lunar hypothesis, that is, the notion that lunar phases can directly affect human behavior, was tested by time-series analysis of 4,575 crisis center telephone calls (all calls recorded for a 6-month interval). As expected, the lunar hypothesis was not supported. The 28-day lunar cycle accounted for less than 1% of the variance of the frequency of crisis center calls. Also, as hypothesized from an attribution theory framework, crisis center workers reported significantly greater belief in lunar effects than a non-crisis-center-worker comparison group.

Starting an aphasia center?

Science.gov (United States)

Elman, Roberta J

2011-08-01

Starting an aphasia center can be an enormous challenge. This article provides initial issues to review and consider when deciding whether starting a new organization is right for you. Determining the need for the program in your community, the best size and possible affiliation for the organization, and available resources, as well as developing a business plan, marketing the program, and building awareness in the community, are some of the factors that are discussed. Specific examples related to starting the Aphasia Center of California are provided. © Thieme Medical Publishers.

Writing Center Administration and/as Emotional Labor

Science.gov (United States)

Jackson, Rebecca; McKinney, Jackie Grutsch; Caswell, Nicole I.

2016-01-01

Scholars have offered research and theory about emotional labor and the feeling of emotion in rhetoric and composition, but we have little if any such research on writing center work specifically. Drawing on data from a year-long qualitative study of writing center directors' labor, this article examines writing center directors' emotional labor…

TOP 01-1-011B Vehicle Test Facilities at Aberdeen Test Center and Yuma Test Center

Science.gov (United States)

2017-12-12

Test Center 400 Colleran Road Aberdeen Proving Ground, MD 21005-5059 U.S. Army Yuma Proving Ground Yuma Test Center 301 C. Street Yuma, AZ...22 2.6 Munson Test Area (MTA) ..................................................... 24 2.7 Land Vehicle Maintenance Facility...127 3.6 Maintenance Facilities ........................................................... 143

Spherical Torus Center Stack Design

International Nuclear Information System (INIS)

C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz

2002-01-01

The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device

Data center networks and network architecture

Science.gov (United States)

Esaki, Hiroshi

2014-02-01

This paper discusses and proposes the architectural framework, which is for data center networks. The data center networks require new technical challenges, and it would be good opportunity to change the functions, which are not need in current and future networks. Based on the observation and consideration on data center networks, this paper proposes; (i) Broadcast-free layer 2 network (i.e., emulation of broadcast at the end-node), (ii) Full-mesh point-to-point pipes, and (iii) IRIDES (Invitation Routing aDvertisement for path Engineering System).

Development and Demise of a Women's Center.

Science.gov (United States)

Liss, Lora

The formation, development, and demise of a women's center in suburban New York are described. The women's center resulted from a conference designed to assess problems confronting women and to mobilize resources to meet those problems. However, after the formation of the center, a struggle for leadership and conflicts over the values and beliefs…

21 CFR 862.1410 - Iron (non-heme) test system.

Science.gov (United States)

2010-04-01

... characterized by pigmentation of the skin), and chronic renal disease. (b) Classification. Class I. ... diagnosis and treatment of diseases such as iron deficiency anemia, hemochromatosis (a disease associated...

NV-centers in nanodiamonds: How good they are

Science.gov (United States)

Plakhotnik, Taras; Aman, Haroon

2018-02-01

This paper presents a method for determination of the size distribution for diamond nanocrystals containing luminescent nitrogen-vacancy (NV) centers using the luminescence intensity only. We also revise the basic photo physical properties of NV centers and conclude that the luminescence quantum yield of such centers is significantly smaller than the frequently stated 100\\%. The yield can be as low as 5\\% for centers embedded in nanocrystals and depends on their shape and the refractive index of the surrounding medium. The paper also addresses the value of the absorption cross-section of NV centers.

Competitive Intelligence and the Information Center.

Science.gov (United States)

Greene, H. Frances

1988-01-01

Examines the competitive intelligence approach to corporate information gathering, and discusses how it differs from the traditional library information center approach. Steps for developing a competitive intelligence system in the library information center are suggested. (33 references) (MES)

National Rehabilitation Hospital Assistive Technology Research Center

Science.gov (United States)

1995-10-01

Shoulder-Arm Orthoses Several years ago, the Rehabilitation Engineering Research Center (RERC) on Rehabilitation Robotics in Delaware1 identified a... exoskeletal applications for persons with disabilities. 2. Create a center of expertise in rehabilitation technology transfer that benefits persons with...AD COOPERATIVE AGREEMENT NUMBER: DAMD17-94-V-4036 TITLE: National Rehabilitation Hospital Assistive Technology- Research Center PRINCIPAL

MSU-Northern Bio-Energy Center of Excellence

Energy Technology Data Exchange (ETDEWEB)

Kegel, Greg [Montana State Univ., Bozeman, MT (United States); Alcorn-Windy Boy, Jessica [Montana State Univ., Bozeman, MT (United States); Abedin, Md. Joynal [Montana State Univ., Bozeman, MT (United States); Maglinao, Randy [Montana State Univ., Bozeman, MT (United States)

2014-09-30

MSU-Northern established the Bio-Energy Center (the Center) into a Regional Research Center of Excellence to address the obstacles concerning biofuels, feedstock, quality, conversion process, economic viability and public awareness. The Center built its laboratories and expertise in order to research and support product development and commercialization for the bio-energy industry in our region. The Center wanted to support the regional agricultural based economy by researching biofuels based on feedstock’s that can be grown in our region in an environmentally responsible manner. We were also interested in any technology that will improve the emissions and fuel economy performance of heavy duty diesel engines. The Center had a three step approach to accomplish these goals: 1. Enhance the Center’s research and testing capabilities 2. Develop advanced biofuels from locally grown agricultural crops. 3. Educate and outreach for public understanding and acceptance of new technology. The Center was very successful in completing the tasks as outlined in the project plan. Key successes include discovering and patenting a new chemical conversion process for converting camelina oil to jet fuel, as well as promise in developing a heterogeneous Grubs catalyst to support the new chemical conversion process. The Center also successfully fragmented and deoxygenated naturally occurring lignin with a Ni-NHC catalyst, showing promise for further exploration of using lignin for fuels and fuel additives. This would create another value-added product for lignin that can be sourced from beetle kill trees or waste products from cellulose ethanol fuel facilities.

Cortical Activation during Landmark-Centered vs. Gaze-Centered Memory of Saccade Targets in the Human: An FMRI Study

Directory of Open Access Journals (Sweden)

Ying Chen

2017-06-01

Full Text Available A remembered saccade target could be encoded in egocentric coordinates such as gaze-centered, or relative to some external allocentric landmark that is independent of the target or gaze (landmark-centered. In comparison to egocentric mechanisms, very little is known about such a landmark-centered representation. Here, we used an event-related fMRI design to identify brain areas supporting these two types of spatial coding (i.e., landmark-centered vs. gaze-centered for target memory during the Delay phase where only target location, not saccade direction, was specified. The paradigm included three tasks with identical display of visual stimuli but different auditory instructions: Landmark Saccade (remember target location relative to a visual landmark, independent of gaze, Control Saccade (remember original target location relative to gaze fixation, independent of the landmark, and a non-spatial control, Color Report (report target color. During the Delay phase, the Control and Landmark Saccade tasks activated overlapping areas in posterior parietal cortex (PPC and frontal cortex as compared to the color control, but with higher activation in PPC for target coding in the Control Saccade task and higher activation in temporal and occipital cortex for target coding in Landmark Saccade task. Gaze-centered directional selectivity was observed in superior occipital gyrus and inferior occipital gyrus, whereas landmark-centered directional selectivity was observed in precuneus and midposterior intraparietal sulcus. During the Response phase after saccade direction was specified, the parietofrontal network in the left hemisphere showed higher activation for rightward than leftward saccades. Our results suggest that cortical activation for coding saccade target direction relative to a visual landmark differs from gaze-centered directional selectivity for target memory, from the mechanisms for other types of allocentric tasks, and from the directionally

Person-Centered Gestalt Therapy: A Synthesis.

Science.gov (United States)

Herlihy, Barbara

1985-01-01

Highlights the similarities between the person-centered approach to counseling of Carl Rogers and the Gestalt therapy of Fritz Perls. Discusses implementation of the two approaches and suggests they may be synthesized into a person-centered Gestalt therapy. (MCF)

Center for Advanced Computational Technology

Science.gov (United States)

Noor, Ahmed K.

2000-01-01

The Center for Advanced Computational Technology (ACT) was established to serve as a focal point for diverse research activities pertaining to application of advanced computational technology to future aerospace systems. These activities include the use of numerical simulations, artificial intelligence methods, multimedia and synthetic environments, and computational intelligence, in the modeling, analysis, sensitivity studies, optimization, design and operation of future aerospace systems. The Center is located at NASA Langley and is an integral part of the School of Engineering and Applied Science of the University of Virginia. The Center has four specific objectives: 1) conduct innovative research on applications of advanced computational technology to aerospace systems; 2) act as pathfinder by demonstrating to the research community what can be done (high-potential, high-risk research); 3) help in identifying future directions of research in support of the aeronautical and space missions of the twenty-first century; and 4) help in the rapid transfer of research results to industry and in broadening awareness among researchers and engineers of the state-of-the-art in applications of advanced computational technology to the analysis, design prototyping and operations of aerospace and other high-performance engineering systems. In addition to research, Center activities include helping in the planning and coordination of the activities of a multi-center team of NASA and JPL researchers who are developing an intelligent synthesis environment for future aerospace systems; organizing workshops and national symposia; as well as writing state-of-the-art monographs and NASA special publications on timely topics.

Extensions of guiding center motion to higher order

International Nuclear Information System (INIS)

Northrop, T.G.; Rome, J.A.

1978-01-01

In a static magnetic field, some well-known guiding center equations maintain their form when extended to next order in gyroradius. In these cases, it is only necessary to include the next order term in the magnetic moment series. The differential equation for guiding center motion which describes both the parallel and perpendicular velocities correctly through first order in gyroradius is given. The question of how to define the guiding center position through second order arises and is discussed, and second order drifts are derived for one usual definition. The toroidal canonical angular momentum, P/sub phi/, of the guiding center in an axisymmetric field is shown to be conserved using the guiding center velocity correct through first order. When second-order motion is included, P/sub phi/ is no longer a constant. The above extensions of guiding center theory help to resolve the different tokamak orbits obtained either by using the guiding center equations of motion or by using conservation of P/sub phi/

Extensions of guiding center motion to higher order

International Nuclear Information System (INIS)

Northrop, T.G.; Rome, J.A.

1977-07-01

In a static magnetic field, some well-known guiding center equations maintain their form when extended to next order in gyroradius. In these cases, it is only necessary to include the next order term in the magnetic moment series. The differential equation for guiding center motion which describes both the parallel and perpendicular velocities correctly through first order in gyroradius is given. The question of how to define the guiding center position through second order arises and is discussed, and second order drifts are derived for one usual definition. The toroidal canonical angular momentum, P/sub phi/, of the guiding center in an axisymmetric field is shown to be conserved using the guiding center velocity correct through first order. When second order motion is included, P/sub phi/ is no longer a constant. The above extensions of guiding center theory help to resolve the different tokamak orbits obtained either by using the guiding center equations of motion or by using conservation of P/sub phi/

Center of mass detection via an active pixel sensor

Science.gov (United States)

Yadid-Pecht, Orly (Inventor); Minch, Brad (Inventor); Pain, Bedabrara (Inventor); Fossum, Eric (Inventor)

2006-01-01

An imaging system for identifying the location of the center of mass (COM) in an image. In one aspect, an imaging system includes a plurality of photosensitive elements arranged in a matrix. A center of mass circuit coupled to the photosensitive elements includes a resistive network and a normalization circuit including at least one bipolar transistor. The center of mass circuit identifies a center of mass location in the matrix and includes: a row circuit, where the row circuit identifies a center of mass row value in each row of the matrix and identifies a row intensity for each row; a horizontal circuit, where the horizontal circuit identifies a center of mass horizontal value; and a vertical circuit, where the vertical circuit identifies a center of mass vertical value. The horizontal and vertical center of mass values indicate the coordinates of the center of mass location for the image.

Centered On The Pole: NCEI Interdisciplinary Arctic Data Stewardship

Science.gov (United States)

Zweng, M.

2016-02-01

In 2014, NOAA's data centers (National Climatic Data Center, National Oceanographic Data Center, National Geophysical Data Center and its affiliated program within the National Snow and Ice Data Center, and the National Coastal Data Development Center) merged to form NCEI, the National Centers for Environmental Information- the largest repository of publicly accessible earth system science data in the world. The merger has forced a reconciling of different workflows, data types, and cultures. However, the Arctic has emerged as a common area where the different centers can integrate their expertise, data assets, and services, and use this information to better align the entire organization. The centers face a unique challenge as they move forward: how to archive, steward and provide access to environmental data to fulfil their mission of providing the best information to help protect life and property. A pressing national need for information that supports policy decisions drives our work.

76 FR 17139 - Health Center Program

Science.gov (United States)

2011-03-28

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Health Resources and Services Administration Health Center Program AGENCY: Health Resources and Services Administration, HHS. ACTION: Notice of Noncompetitive... Improvement Project (CIP) from Saint Vincent's Catholic Medical Centers (SVCMC) of New York, current grantee...

Implementing a Reliability Centered Maintenance Program at NASA's Kennedy Space Center

National Research Council Canada - National Science Library

Tuttle, Raymond

1998-01-01

.... A reliability centered maintenance (RCM) program seeks to offer equal or greater reliability at decreased cost by insuring only applicable, effective maintenance is performed and by in large part replacing time based maintenance...

Carbon dioxide Information Analysis Center and World Data Center: A for Atmospheric trace gases. Annual progress report, FY 1994

Energy Technology Data Exchange (ETDEWEB)

Burtis, M.D. [comp.] [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.R.; Stoss, F.W. [Oak Ridge National Lab., TN (United States)

1995-03-01

This report summarizes the activities and accomplishments made by the Carbon Dioxide Information Analysis Center and World Data Center-A for Atmospheric Trace Gases during the fiscal year 1994. Topics discussed in this report include; organization and staff, user services, systems, communications, Collaborative efforts with China, networking, ocean data and activities of the World Data Center-A.

A multipurpose radiation service center

International Nuclear Information System (INIS)

Hofmann, E.-G.

1977-01-01

In Germany, AEG-Telefunken has been working as a supplier of irradiation equipment for more than ten years. There is a close cooperation with Radiation Dynamics Inc., Westbury, N.Y. Radiation sources are available for most industrial applications. As a special service AEG is establishing a multipurpose radiation service center in Hamburg-Wedel, Germany. This center will be used by a host of companies to investigate the effects of radiation on a broad range of materials, to develop special processing equipment, to process customer supplied products and to perform R and D work and contracts. Initially this service center will be equipped with one research type High-Power X-ray Unit (200 kV/32 mA) and one industrial type Dynamitron accelerator (1500 kV/37.5 kW). (author)

Textile materials trading center formally launched online

Institute of Scientific and Technical Information of China (English)

无

2012-01-01

Textile materials trading center was formally launched online in Wuxi City,Jiangsu Province. This is the first third-party electronic trading platform for spot trading in China textile materials professional market. The project will strive to build the most influential textile materials trading center of East China,the whole country and even the whole world China textile materials trading center will be

Holistic Approach to Data Center Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

Hammond, Steven W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-18

This presentation discusses NREL's Energy System Integrations Facility and NREL's holistic design approach to sustainable data centers that led to the world's most energy-efficient data center. It describes Peregrine, a warm water liquid cooled supercomputer, waste heat reuse in the data center, demonstrated PUE and ERE, and lessons learned during four years of operation.

User-centered agile method

CERN Document Server

Deuff, Dominique

2013-01-01

Agile development methods began to emerge around 20 years ago. However, it was not until the early 2000s that they began to be widely used in industry. This growth was often due to the advent of Internet services requiring faster cycles of development in order to heighten the rate at which an ever-greater number of functionalities were made available. In parallel, user-centered design (UCD) methods were also becoming more and more widely used: hence, user-centered design and agile methods were bound to cross paths, at least in the telecoms industry! During this period, in the field of telec

75 FR 32169 - Comprehensive Centers Program

Science.gov (United States)

2010-06-07

... of proposed waivers were supportive of the Comprehensive Centers program and the proposed waivers... Department to continue promoting this shared oversight by involving OSERS leadership in deliberations about... identification of the valuable contribution of OSERS leadership in supporting the Comprehensive Centers program...

Alternative Fuels Data Center: Biodiesel Benefits

Science.gov (United States)

, and transport. Maps & Data U.S. Biodiesel Production, Exports, and Consumption U.S. Biodiesel Benefits to someone by E-mail Share Alternative Fuels Data Center: Biodiesel Benefits on Facebook Tweet about Alternative Fuels Data Center: Biodiesel Benefits on Twitter Bookmark Alternative Fuels Data

Forging successful academic-community partnerships with community health centers: the California statewide Area Health Education Center (AHEC) experience.

Science.gov (United States)

Fowkes, Virginia; Blossom, H John; Mitchell, Brenda; Herrera-Mata, Lydia

2014-01-01

Increased access to insurance under the Affordable Care Act will increase demands for clinical services in community health centers (CHCs). CHCs also have an increasingly important educational role to train clinicians who will remain to practice in community clinics. CHCs and Area Health Education Centers (AHECs) are logical partners to prepare the health workforce for the future. Both are sponsored by the Health Resources and Services Administration, and they share a mission to improve quality of care in medically underserved communities. AHECs emphasize the educational side of the mission, and CHCs the service side. Building stronger partnerships between them can facilitate a balance between education and service needs.From 2004 to 2011, the California Statewide AHEC program and its 12 community AHECs (centers) reorganized to align training with CHC workforce priorities. Eight centers merged into CHC consortia; others established close partnerships with CHCs in their respective regions. The authors discuss issues considered and approaches taken to make these changes. Collaborative innovative processes with program leadership, staff, and center directors revised the program mission, developed common training objectives with an evaluation plan, and defined organizational, functional, and impact characteristics for successful AHECs in California. During this planning, centers gained confidence as educational arms for the safety net and began collaborations with statewide programs as well as among themselves. The AHEC reorganization and the processes used to develop, strengthen, and identify standards for centers forged the development of new partnerships and established academic-community trust in planning and implementing programs with CHCs.

World Trade Center

Index Scriptorium Estoniae

2006-01-01

Esilinastus katastroofifilm "World Trade Center" : stsenarist Andrea Berloff : režissöör Oliver Stone : kunstnik Jan Roelfs : osades Nicholas Cage, Michael Pena, Stephen Dorff jpt : Ameerika Ühendriigid 2006. Ka filmi prototüüpidest

Design of Shanghai irradiation center

International Nuclear Information System (INIS)

Chen Fugen; Lu Zhongwen; Xue Xiangrong; Yao Zewu; Du Bende; Xu Zhicheng; Du Kangsen

1988-01-01

Shanghai Irradiation Center, situated in westrn suburb of Shanghai, was completed in August, 1986. At present, a 6.55 x 10 15 Bq 60 Co source has been loaded, though the designed activity of maximum loading is 18.5 x 10 10 Bq. the center is designed mainly for irradiation preservation of food and sterilization of medical devices and tools. Its processing ability is 10 t/h for potatoes

Distribution control centers in the Croatian power system with particular consideration on ZAgreb distribution control center

International Nuclear Information System (INIS)

Cupin, N.

2000-01-01

Discussion about control of Croatian Power system in the view of forthcoming free electricity market did not included do far distribution level. With this article we would like to clarify the role of distribution control centers pointing out importance of Zagreb Distribution control center, with controls one third of Croatian (HEP) consumption. (author)

75 FR 47301 - Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC...

Science.gov (United States)

2010-08-05

...- 000; EG10-34-000; EG10-34-000; EG10-35-000; EG10-36-000; EG10-37-000; EG10-38-000] Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC; Wessington Wind Energy Center, LLC; Juniper Canyon Wind Power LLC; Loraine Windpark Project, LLC; White Oak Energy LLC; Meadow...

Frequency of adoption of practice management guidelines at trauma centers

Science.gov (United States)

Sobrino, Justin; Barnes, Sunni A.; Dahr, Nadine; Kudyakov, Rustam; Berryman, Candice; Nathens, Avery B.; Hemmila, Mark R.; Neal, Melanie

2013-01-01

Evidence-based management guidelines have been shown to improve patient outcomes, yet their utilization by trauma centers remains unknown. This study measured adoption of practice management guidelines or protocols by trauma centers. A survey of 228 trauma centers was conducted over 1 year; 55 completed the survey. Centers were classified into three groups: noncompliant, partially compliant, and compliant with adoption of management protocols. Characteristics of compliant centers were compared with those of the other two groups. Most centers were Level I (58%) not-for-profit (67%) teaching hospitals (84%) with a surgical residency (74%). One-third of centers had an accredited fellowship in surgical critical care (37%). Only one center was compliant with all 32 management protocols. Half of the centers were compliant with 14 of 32 protocols studied (range, 4 to 32). Of the 21 trauma center characteristics studied, only two were independently associated with compliant centers: use of physician extenders and daily attending rounds (both P < .0001). Adoption of management guidelines by trauma centers is inconsistent, with wide variations in practices across centers. PMID:23814383

Outline of Toshiba Business Information Center

Science.gov (United States)

Nagata, Yoshihiro

Toshiba Business Information Center gathers and stores inhouse and external business information used in common within the Toshiba Corp., and provides companywide circulation, reference and other services. The Center established centralized information management system by employing decentralized computers, electronic file apparatus (30cm laser disc) and other office automation equipments. Online retrieval through LAN is available to search the stored documents and increasing copying requests are processed by electronic file. This paper describes the purpose of establishment of the Center, the facilities, management scheme, systematization of the files and the present situation and plan of each information service.

Bridgehead isomer effects in bis(phosphido)-bridged diiron hexacarbonyl proton reduction electrocatalysts.

Science.gov (United States)

Rahaman, Ahibur; Gimbert-Suriñach, Carolina; Ficks, Arne; Ball, Graham E; Bhadbhade, Mohan; Haukka, Matti; Higham, Lee; Nordlander, Ebbe; Colbran, Stephen B

2017-03-07

The influence of the substitution, orientation and structure of the phosphido bridges in [Fe 2 (CO) 6 (μ-PR 2 ) 2 ] electrocatalysts of proton reduction has been studied. The isomers e,a-[Fe 2 (CO) 6 {μ-P(Ar)H} 2 ] (1a(Ar): Ar = Ph, 2'-methoxy-1,1'-binaphthyl (bn')), e,e-[Fe 2 (CO) 6 {μ-P(Ar)H} 2 ] (1b(Ar): Ar = Ph, bn') were isolated from reactions of iron pentacarbonyl and the corresponding primary phosphine, syntheses that also afforded the phosphinidene-capped tri-iron clusters, [Fe 3 (CO) 9 (μ-CO)(μ 3 -Pbn')] (2) and [Fe 3 (CO) 9 (μ 3 -PAr) 2 ] (3(Ar), Ar = Ph, bn'). A ferrocenyl (Fc)-substituted dimer [Fe 2 (CO) 6 {μ:μ'-1,2-(P(CH 2 Fc)CH 2 ) 2 C 6 H 4 }] (4), in which the two phosphido bridges are linked by an o-xylyl group, was also prepared. The molecular structures of complexes 1a(Ph), 1b(Ph), 1b(bn'), 2 and 4 were established by X-ray crystallography. All complexes have been examined as electrocatalysts for proton reduction using p-toluene sulfonic acid in tetrahydrofuran. Cyclic voltammograms of the dimers with acid exhibit two catalysis waves for proton reduction. The first wave, which appears at the potential of the primary reduction, reaches maximum current (turnover) at moderate acid concentrations and is rapidly overtaken by the second wave, which appears at more negative potential. Both of these reductive waves show an initial first order dependence on acid. The electrochemistry and electrocatalyses of the [Fe 2 (CO) 6 (μ-PR 2 ) 2 ] dimers show subtle variations with the nature of the bridging phosphido group(s), including the orientation of bridgehead hydrogen atoms.

Medical Waste Management in Community Health Centers.

Science.gov (United States)

Tabrizi, Jafar Sadegh; Rezapour, Ramin; Saadati, Mohammad; Seifi, Samira; Amini, Behnam; Varmazyar, Farahnaz

2018-02-01

Non-standard management of medical waste leads to irreparable side effects. This issue is of double importance in health care centers in a city which are the most extensive system for providing Primary Health Care (PHC) across Iran cities. This study investigated the medical waste management standards observation in Tabriz community health care centers, northwestern Iran. In this triangulated cross-sectional study (qualitative-quantitative), data collecting tool was a valid checklist of waste management process developed based on Iranian medical waste management standards. The data were collected in 2015 through process observation and interviews with the health center's staff. The average rate of waste management standards observance in Tabriz community health centers, Tabriz, Iran was 29.8%. This case was 22.8% in dimension of management and training, 27.3% in separating and collecting, 31.2% in transport and temporary storage, and 42.9% in sterilization and disposal. Lack of principal separation of wastes, inappropriate collecting and disposal cycle of waste and disregarding safety tips (fertilizer device performance monitoring, microbial cultures and so on) were among the observed defects in health care centers supported by quantitative data. Medical waste management was not in a desirable situation in Tabriz community health centers. The expansion of community health centers in different regions and non-observance of standards could predispose to incidence the risks resulted from medical wastes. So it is necessary to adopt appropriate policies to promote waste management situation.

The Universe Observation Center: an educational center devoted to Astronomy in Catalonia

Science.gov (United States)

Fernández, D.

The Universe Observation Center (in Catalan language, Centre d'Observació de l'Univers, COU) is located in close proximity to the Montsec Astronomical Observatory (Observatori Astronòmic del Montsec, OAM), in eastern Catalonia (Spain). Both centers comprise the Montsec Astronomical Park (Parc Astronòmic Montsec, PAM), managed by the Consorci del Montsec. Montsec Mountain remains the finest location for astronomical observation in Catalonia, as demonstrated by a site-testing campaign conducted by the Astronomy and Meteorology Department of the University of Barcelona. The COU consists of a Central Building (including a permanent exhibition and three classrooms possessing broadband Internet access), the Telescope Park (two astronomical domes equipped with medium-size telescopes, a coelostat for solar observation, and a portable telescope park), the Eye of Montsec (a digital planetarium and, at the same time, an extremely innovative platform for sky observation) and the Garden of the Universe (a tour of the land surrounding the COU, visiting several areas within it). The COU will offer to the Spanish academic community a host of fascinating and unique activities in the fields of astronomy and geology. The Center is open not only to students (from primary school through university), but also to amateur astronomers, people interested in science and the general public.

Center for Beam Physics, 1993

International Nuclear Information System (INIS)

1994-05-01

The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center's mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993

A Comparative Analysis of Patient Access Modes at Wilford Hall United States Air Force Medical Center and Selected Civilian Medical Centers

Science.gov (United States)

1983-12-01

In A COMPARATIVE ANALYSIS OF PATIENT ACCESS MODES AT WILFORD HALL UNITED STATES AIR FORCE MEDICAL CENTER N AND SELECTED CIVILIAN MEDICAL CENTERS0 N...current patient access modes at WHMC and several civilian medical centers of comparable size. This project has pursued the subject of patient access in...selected civilian medical centers which are comparable to WHMC in size, specialty mix, workload, and mission, providing responsive and efficient patient

Patients' preferences for patient-centered communication

DEFF Research Database (Denmark)

Lau, Sofie Rosenlund; Christensen, Søren Troels; Andreasen T., Jesper

2013-01-01

To investigate patients' preferences for patient-centered communication (PCC) in the encounter with healthcare professionals in an outpatient department in rural Sierra Leone.......To investigate patients' preferences for patient-centered communication (PCC) in the encounter with healthcare professionals in an outpatient department in rural Sierra Leone....

[Patient-centered care. Improvement of communication between university medical centers and general practitioners for patients in neuro-oncology].

Science.gov (United States)

Renovanz, M; Keric, N; Richter, C; Gutenberg, A; Giese, A

2015-12-01

Communication between university medical centers and general practitioners (GP) is becoming increasingly more important in supportive patient care. A survey among GPs was performed with the primary objective to assess their opinion on current workflow and communication between GPs and the university medical center. The GPs were asked to score (grades 1-6) their opinion on the current interdisciplinary workflow in the care of patients with brain tumors, thereby rating communication between a university medical center in general and the neuro-oncology outpatient center in particular. Questionnaires were sent to1000 GPs and the response rate was 15 %. The mean scored evaluation of the university medical center in general was 2.62 and of the neuro-oncological outpatient clinic 2.28 (range 1-6). The most often mentioned issues to be improved were easier/early telephone information (44 %) and a constantly available contact person (49 %). Interestingly, > 60 % of the GPs indicated they would support web-based tumor boards for interdisciplinary and palliative neuro-oncological care. As interdisciplinary care for neuro-oncology patients is an essential part of therapy, improvement of communication between GPs and university medical centers is indispensable. Integrating currently available electronic platforms under data protection aspects into neuro-oncological palliative care could be an interesting tool in order to establish healthcare networks and could find acceptance with GPs.

Alternative Fuels Data Center: Conventional Natural Gas Production

Science.gov (United States)

Conventional Natural Gas Production to someone by E-mail Share Alternative Fuels Data Center : Conventional Natural Gas Production on Facebook Tweet about Alternative Fuels Data Center: Conventional Natural Gas Production on Twitter Bookmark Alternative Fuels Data Center: Conventional Natural Gas Production

Optical wireless communication in data centers

Science.gov (United States)

Arnon, Shlomi

2018-01-01

In the last decade data centers have become a crucial element in modern human society. However, to keep pace with internet data rate growth, new technologies supporting data center should develop. Integration of optical wireless communication (OWC) in data centers is one of the proposed technologies as augmented technology to the fiber network. One implementation of the OWC technology is deployment of optical wireless transceiver on top of the existing cable/fiber network as extension to the top of rack (TOR) switch; in this way, a dynamic and flexible network is created. Optical wireless communication could reduce energy consumption, increase the data rate, reduce the communication latency, increase flexibility and scalability, and reduce maintenance time and cost, in comparison to extra fiber network deployment. In this paper we review up to date literature in the field, propose an implementation scheme of OWC network, discuss ways to reduce energy consumption by parallel link communication and report preliminary measurement result of university data center environment.

United States Data Center Energy Usage Report

Energy Technology Data Exchange (ETDEWEB)

Shehabi, Arman [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Smith, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sartor, Dale [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Herrlin, Magnus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Koomey, Jonathan [Stanford Univ., CA (United States); Masanet, Eric [Northwestern Univ., Evanston, IL (United States); Horner, Nathaniel [Carnegie Mellon Univ., Pittsburgh, PA (United States); Azevedo, Inês [Carnegie Mellon Univ., Pittsburgh, PA (United States); Lintner, William [Dept. of Energy (DOE), Washington DC (United States)

2016-06-01

This report estimates historical data center electricity consumption back to 2000, relying on previous studies and historical shipment data, and forecasts consumption out to 2020 based on new trends and the most recent data available. Figure ES-1 provides an estimate of total U.S. data center electricity use (servers, storage, network equipment, and infrastructure) from 2000-2020. In 2014, data centers in the U.S. consumed an estimated 70 billion kWh, representing about 1.8% of total U.S. electricity consumption. Current study results show data center electricity consumption increased by about 4% from 2010-2014, a large shift from the 24% percent increase estimated from 2005-2010 and the nearly 90% increase estimated from 2000-2005. Energy use is expected to continue slightly increasing in the near future, increasing 4% from 2014-2020, the same rate as the past five years. Based on current trend estimates, U.S. data centers are projected to consume approximately 73 billion kWh in 2020.

Thermal reorientation of hydrogenic Pr3+ centers

International Nuclear Information System (INIS)

Jones, G. D.

1996-01-01

Sets of five multi-hydrogenic centers of both CaF 2 :Pr 3+ and SrF 2 :Pr 3 + show bleaching under selective polarized-light irradiation. Two forms of bleaching behaviour are observed. In reversible polarized bleaching, irradiation creates re-oriented equivalent centers, which can be restored to the original orientation by switching the laser polarization by 90 deg. Indefinite sequences of bleaching and recovery can be established. In photoproduct bleaching, inequivalent centers are produced, which can be reverted by subsequently selectively exciting their absorption lines. Thermal recovery of the bleached centers on warming the crystals occurs abruptly over a 5 K range around 100 K and is noteworthy in occurring at essentially identical temperatures for H - , D - and T - centers. The simplest model for this thermal recovery is thermal activation of the mobile hydrogenic ions over a double well potential barrier. An alternative model proposed by Universitaet Regensburg requires the involvement of high frequency excitations in scattering processes for surmounting the barrier

Louisiana Speaks Regional Plan Vision Reinvestment Centers, UTM Zone 15N NAD83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_reinvestment_centers

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates reinvestment centers included in the Louisiana Speaks Regional Plan Vision. Reinvestment centers highlight communities that...

Lower Savannah aging, disability & transportation resource center : regional travel management and coordination center (TMCC) model and demonstration project.

Science.gov (United States)

2014-10-01

This report details the deployed technology and implementation experiences of the Lower Savannah Aging, Disability & Transportation : Resource Center in Aiken, South Carolina, which served as the regional Travel Management and Coordination Center (TM...

DOE - BES Nanoscale Science Research Centers (NSRCs)

Energy Technology Data Exchange (ETDEWEB)

Beecher, Cathy Jo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-11-14

These are slides from a powerpoint shown to guests during tours of Center for Integrated Nanotechnologies (CINT) at Los Alamos National Laboratory. It shows the five DOE-BES nanoscale science research centers (NSRCs), which are located at different national laboratories throughout the country. Then it goes into detail specifically about the Center for Integrated Nanotechnologies at LANL, including statistics on its user community and CINT's New Mexico industrial users.

Climate Prediction Center - Atlantic Hurricane Outlook

Science.gov (United States)

Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Home Site Map News ; Seasonal Climate Summary Archive The 2018 Atlantic hurricane season outlook is an official product of the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC). The outlook is

Networking at NASA. Johnson Space Center

Science.gov (United States)

Garman, John R.

1991-01-01

A series of viewgraphs on computer networks at the Johnson Space Center (JSC) are given. Topics covered include information resource management (IRM) at JSC, the IRM budget by NASA center, networks evolution, networking as a strategic tool, the Information Services Directorate charter, and SSC network requirements, challenges, and status.

Marketing and Community Mental Health Centers.

Science.gov (United States)

Ferniany, Isaac W.; Garove, William E.

1983-01-01

Suggests that a marketing approach can be applied to community mental health centers. Marketing is a management orientation of providing services for, not to, patients in a systematic manner, which can help mental health centers improve services, strengthen community image, achieve financial independence and aid in staff recruitment. (Author)

Kennedy Space Center's NASA/Contractor Team-Centered Total Quality Management Seminar: Results, methods, and lessons learned

Science.gov (United States)

Kinlaw, Dennis C.; Eads, Jeannette

1992-01-01

It is apparent to everyone associated with the Nation's aeronautics and space programs that the challenge of continuous improvement can be reasonably addressed only if NASA and its contractors act together in a fully integrated and cooperative manner that transcends the traditional boundaries of proprietary interest. It is, however, one thing to assent to the need for such integration and cooperation; it is quite another thing to undertake the hard tasks of turning such a need into action. Whatever else total quality management is, it is fundamentally a team-centered and team-driven process of continuous improvement. The introduction of total quality management at KSC, therefore, has given the Center a special opportunity to translate the need for closer integration and cooperation among all its organizations into specific initiatives. One such initiative that NASA and its contractors have undertaken at KSC is a NASA/Contractor team-centered Total Quality Management Seminar. It is this seminar which is the subject of this paper. The specific purposes of this paper are to describe the following: Background, development, and evolution of Kennedy Space Center's Total Quality Management Seminar; Special characteristics of the seminar; Content of the seminar; Meaning and utility of a team-centered design for TQM training; Results of the seminar; Use that one KSC contractor, EG&G Florida, Inc. has made of the seminar in its Total Quality Management initiative; and Lessons learned.

Software package as an information center product

International Nuclear Information System (INIS)

Butler, M.K.

1977-01-01

The Argonne Code Center serves as a software exchange and information center for the U.S. Energy Research and Development Administration and the Nuclear Regulatory Commission. The goal of the Center's program is to provide a means for sharing of software among agency offices and contractors, and for transferring computing applications and technology, developed within the agencies, to the information-processing community. A major activity of the Code Center is the acquisition, review, testing, and maintenance of a collection of software--computer systems, applications programs, subroutines, modules, and data compilations--prepared by agency offices and contractors to meet programmatic needs. A brief review of the history of computer program libraries and software sharing is presented to place the Code Center activity in perspective. The state-of-the-art discussion starts off with an appropriate definition of the term software package, together with descriptions of recommended package contents and the Carter's package evaluation activity. An effort is made to identify the various users of the product, to enumerate their individual needs, to document the Center's efforts to meet these needs and the ongoing interaction with the user community. Desirable staff qualifications are considered, and packaging problems, reviewed. The paper closes with a brief look at recent developments and a forecast of things to come. 2 tables

Optical properties of T-centers under gamma irradiation

CERN Document Server

Polosan, S; Dragusin, M; Topa, V

2003-01-01

Electrolytic coloring of KCl:Pb crystals, leads to formation of negative metal ions with intense emission in the infrared region. These new color centers were named T centers; their most probable configuration could be Pb sub 2 sup 2 sup - , due to the lack of EPR or DCM signals. In order to destroy these structures, the crystals were irradiated with gamma-rays at high doses. The results were the detachment of the electrons from T centers and the appearance of Pb sup 2 sup + - ions. The possibility cannot be excluded of the existence of Pb sup + and Pb sup 0 centers in the samples, because these centers do not exhibit any optical properties on this spectral region. (authors)

Climate Prediction Center - Outlooks: Current UV Index Forecast Map

Science.gov (United States)

Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Home Site Map News Service NOAA Center for Weather and Climate Prediction Climate Prediction Center 5830 University Research Court College Park, Maryland 20740 Page Author: Climate Prediction Center Internet Team Disclaimer

Alternative Fuels Data Center: Diesel Vehicles Using Biodiesel

Science.gov (United States)

Biodiesel Printable Version Share this resource Send a link to Alternative Fuels Data Center : Diesel Vehicles Using Biodiesel to someone by E-mail Share Alternative Fuels Data Center: Diesel Vehicles Using Biodiesel on Facebook Tweet about Alternative Fuels Data Center: Diesel Vehicles Using Biodiesel

Cancer Centers: Their Relationship to the Academic Community

Science.gov (United States)

Yarbro, John W.; Newell, Guy R.

1976-01-01

Cancer centers have evolved several types of administrative structures, the most successful using some modification of a matrix system with delegation of significant administrative authority to the center. The author suggests implications for other multidisciplinary centers which find themselves in conflict with traditional discipline…

Radiation-induced centers in inorganic glasses

International Nuclear Information System (INIS)

Brekhovskikh, S.M.; Tyul'nin, V.A.

1988-01-01

The nature, structure and formation mechanisms of radiation-induced colour centers, EPR, luminescence, generated ionizing radiation in nonorganic oxide glasses are considered. Experimental material covering both fundamental aspects of radiation physics and glass chemistry, and aspects intimately connected with the creation of new materials with the given radiation-spectral characteristics, with possibilities to prepare radiation-stable and radiation-sensitive glasses is systematized and generalized. Considerable attention is paid to the detection of radiation-induced center binding with composition, glass structures redox conditions for their synthesis. Some new possibilities of practical application of glasses with radiation-induced centers, in particular, to record optical information are reflected in the paper

Human Centered Hardware Modeling and Collaboration

Science.gov (United States)

Stambolian Damon; Lawrence, Brad; Stelges, Katrine; Henderson, Gena

2013-01-01

In order to collaborate engineering designs among NASA Centers and customers, to in clude hardware and human activities from multiple remote locations, live human-centered modeling and collaboration across several sites has been successfully facilitated by Kennedy Space Center. The focus of this paper includes innovative a pproaches to engineering design analyses and training, along with research being conducted to apply new technologies for tracking, immersing, and evaluating humans as well as rocket, vehic le, component, or faci lity hardware utilizing high resolution cameras, motion tracking, ergonomic analysis, biomedical monitoring, wor k instruction integration, head-mounted displays, and other innovative human-system integration modeling, simulation, and collaboration applications.

Ocean Prediction Center

Science.gov (United States)

Social Media Facebook Twitter YouTube Search Search For Go NWS All NOAA Weather Analysis & Forecasts of Commerce Ocean Prediction Center National Oceanic and Atmospheric Administration Analysis & Unified Surface Analysis Ocean Ocean Products Ice & Icebergs NIC Ice Products NAIS Iceberg Analysis

Optical Multidimensional Switching for Data Center Networks

OpenAIRE

Kamchevska, Valerija; Galili, Michael; Oxenløwe, Leif Katsuo; Berger, Michael Stübert

2017-01-01

Optical switches are known for the ability to provide high bandwidth connectivity at a relatively low power consumption and low latency. Several recent demonstrations on optical data center architectures confirm the potential for introducing all-optical switching within the data center, thus avoiding power hungry optical-electrical-optical conversions at each node. This Ph.D. thesis focuses precisely on the application of optical technologies in data center networks where optics is not only u...

Nuclear Energy Center Site Survey, 1975. Part II. The U.S. electric power system and the potential role of nuclear energy centers

International Nuclear Information System (INIS)

1976-01-01

Information related to Nuclear Energy Centers (NEC) in the U.S. is presented concerning the U.S. electric power system today; electricity demand history and forecasts; history and forecasts of the electric utility industry; regional notes; the status, history, and forecasts of the nuclear role; power plant siting problems and practices; nuclear facilities siting problems and practices; origin and evolution of the nuclear energy center concept; conceptualized description of nuclear energy centers; potential role of nuclear energy centers; assumptions, criteria, and bases; typical evolution of a nuclear energy center; and the nuclear fuel cycle

ENERGY STAR Certified Data Center Storage

Science.gov (United States)

Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Data Center Storage that are effective as of December 2, 2013. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/certified-products/detail/data_center_storage

Global financial centers: shifting power balance

NARCIS (Netherlands)

Aalbers, M.B.

2009-01-01

London and New York are the most important global financial centers in the world. Tokyo used to be considered the third global financial center, but has lost its position in the last 20 years, partly as a result of a sustained recession and partly because both Japanese society and Japanese economy

Structure Biology of Membrane Bound Enzymes

Energy Technology Data Exchange (ETDEWEB)

Fu, Dax [Johns Hopkins Univ., Baltimore, MD (United States). School of Medicine. Dept. of Physiology

2016-11-30

The overall goal of the proposed research is to understand the membrane-associated active processes catalyzed by an alkane $\\square$-hydroxylase (AlkB) from eubacterium Pseudomonase oleovorans. AlkB performs oxygenation of unactivated hydrocarbons found in crude oils. The enzymatic reaction involves energy-demanding steps in the membrane with the uses of structurally unknown metal active sites featuring a diiron [FeFe] center. At present, a critical barrier to understanding the membrane-associated reaction mechanism is the lack of structural information. The structural biology efforts have been challenged by technical difficulties commonly encountered in crystallization and structural determination of membrane proteins. The specific aims of the current budget cycle are to crystalize AlkB and initiate X-ray analysis to set the stage for structural determination. The long-term goals of our structural biology efforts are to provide an atomic description of AlkB structure, and to uncover the mechanisms of selective modification of hydrocarbons. The structural information will help elucidating how the unactivated C-H bonds of saturated hydrocarbons are oxidized to initiate biodegradation and biotransformation processes. The knowledge gained will be fundamental to biotechnological applications to biofuel transformation of non-edible oil feedstock. Renewable biodiesel is a promising energy carry that can be used to reduce fossil fuel dependency. The proposed research capitalizes on prior BES-supported efforts on over-expression and purification of AlkB to explore the inner workings of a bioenergy-relevant membrane-bound enzyme.

FBR Plant Engineering Center annual report 2012

International Nuclear Information System (INIS)

2013-12-01

This annual report shows the last year's R and D activities of currently-reorganized FBR Plant Engineering Center, which was established on April 1, 2009. FBR Safety Technology Center was founded on April 1, 2013 by the consolidation of both the activities of 'former FBR Plant Engineering Center' and a portion of 'FBR Safety Evaluation Unit, Advanced Nuclear System Research and Development Directorate', especially concentrating on safety evaluations and analyses for severe accidents. As for FBR safety technology, it is necessary to continuously make an effort for compliance with new safety regulations in preparation for 'Monju' to restart, for safety enhancement evaluation and for safety technology upgrading. In this context, the new organization was founded in order to reinforce the safety evaluation capability, which will surely and steadily promote FBR safety-technology related activities. As a result, FBR Plant Engineering Center was abolished. This report summarizes the R and D activities at the former FBR Plant Engineering Center, aiming at contributing to the commercialization by using operation experiences and technology development results derived from the actual reactor 'Monju'. The activities are divided into five areas of operation-and-maintenance engineering, sodium engineering, reactor-core-and-fuel engineering, plant engineering, and safety engineering. This annual report is intended for a report of the activities of individual researcher in the center rather than that of the progress of the center as a whole. This will clarify the individual themes, progresses and problems of each researcher, which will, hopefully, facilitate communication with the outside researchers. (author)

Italy INAF Analysis Center Report

Science.gov (United States)

Negusini, M.; Sarti, P.

2013-01-01

This report summarizes the activity of the Italian INAF VLBI Analysis Center. Our Analysis Center is located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the National Institute of Astrophysics. IRA runs the observatories of Medicina and Noto, where two 32-m VLBI AZ-EL telescopes are situated. This report contains the AC's VLBI data analysis activities and shortly outlines the investigations into the co-locations of space geodetic instruments.

Subject-centered free-response ROC (FROC) analysis

OpenAIRE

Bandos, Andriy I.; Rockette, Howard E.; Gur, David

2013-01-01

Purpose: To develop an approach of estimating subject-centered free-response receiver operating characteristic (FROC) curve for providing patient-centered inferences regarding detection-localization characteristics of a diagnostic system.

Dynamic centering of liquid shells

International Nuclear Information System (INIS)

Tsamopoulos, J.A.; Brown, R.A.

1987-01-01

The moderate-amplitude axisymmetric oscillations of an inviscid liquid shell surrounding an incompressible gas bubble are calculated by a multiple-time-scale expansion for initial deformations composed of two-lobed perturbations of the shell and a displacement of the bubble from the center of mass of the liquid. Two types of small-amplitude motion are identified and lead to very different nonlinear dynamic interactions, as described by the results valid up to second order in the amplitude of the initial deformation. In the ''bubble mode,'' the oscillations of the captive bubble and the liquid shell are exactly in phase and the bubble vibrates about its initial eccentric location. The bubble moves toward the center of the drop when the shell is perturbed into a ''sloshing mode'' of oscillation where both interfaces move out of phase. These results explain the centering of liquid shells observed in several experiments

Multifunctional centers in rural areas

DEFF Research Database (Denmark)

Svendsen, Gunnar Lind Haase

2009-01-01

abandoned. One outcome has been closings of schools in remote rural areas. This evidently contributes to exacerbate depopulation in these areas. To stop this tendency, we need new models for high-quality, cost effective public services in rural areas as those as we find in Denmark. This chapter introduces...... ideological roots in history pointing at 19th c. national civic movements and an early 20th c. transnational Garden City movement within urban planning as crucial. Drawing on contemporary case studies of multifunctional centers in Holland and Denmark, I then suggest that public and private donors should...... invest in multifunctional centers in which the local public school is the dynamo. This in order to increase local levels of social as well as human capital. Ideally, such centers should contain both public services such as school, library and health care, private enterprises as hairdressers and banks...

Center for beam physics 1996-1997

International Nuclear Information System (INIS)

1997-02-01

The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center's mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center's program include addressing R ampersand D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R ampersand D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R ampersand D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP's outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997

Importance of Grid Center Arrangement

Science.gov (United States)

Pasaogullari, O.; Usul, N.

2012-12-01

In Digital Elevation Modeling, grid size is accepted to be the most important parameter. Despite the point density and/or scale of the source data, it is freely decided by the user. Most of the time, arrangement of the grid centers are ignored, even most GIS packages omit the choice of grid center coordinate selection. In our study; importance of the arrangement of grid centers is investigated. Using the analogy between "Raster Grid DEM" and "Bitmap Image", importance of placement of grid centers in DEMs are measured. The study has been conducted on four different grid DEMs obtained from a half ellipsoid. These grid DEMs are obtained in such a way that they are half grid size apart from each other. Resulting grid DEMs are investigated through similarity measures. Image processing scientists use different measures to investigate the dis/similarity between the images and the amount of different information they carry. Grid DEMs are projected to a finer grid in order to co-center. Similarity measures are then applied to each grid DEM pairs. These similarity measures are adapted to DEM with band reduction and real number operation. One of the measures gives function graph and the others give measure matrices. Application of similarity measures to six grid DEM pairs shows interesting results. These four different grid DEMs are created with the same method for the same area, surprisingly; thirteen out of 14 measures state that, the half grid size apart grid DEMs are different from each other. The results indicated that although grid DEMs carry mutual information, they have also additional individual information. In other words, half grid size apart constructed grid DEMs have non-redundant information.; Joint Probability Distributions Function Graphs

My Place or Yours: Theorizing Eclectic Writing Centers.

Science.gov (United States)

Rossini, Carol

None of the theories that inform writing center work--Freudian theory, cognitivism, feminism, postmodernism, current-traditionalism, expressivism, social constructionism, and family systems theory--offer an adequate basis for writing center work. Even when Stephen North proposed "The Idea of a Writing Center" in 1984 (still considered to…

Characterizing customers at medical center farmers’ markets1

Science.gov (United States)

Kraschnewski, Jennifer L.; George, Daniel R.; Rovniak, Liza S.; Monroe, Diana L.; Fiordalis, Elizabeth; Bates, Erica

2014-01-01

Approximately 100 farmers’ markets operate on medical center campuses. Although these venues can uniquely serve community health needs, little is known about customer characteristics and outreach efforts. Intercept survey of markets and market customers between August 2010-October 2011 at three medical centers in different geographic regions of the US: Duke University Medical Center, Cleveland Clinic, and Penn State Hershey Medical Center were conducted. Markets reported serving 180–2000 customers per week and conducting preventive medicine education sessions and community health programs. Customers (n=585) across markets were similar in sociodemographic characteristics – most were middle-aged, white, and female, who were employees of their respective medical center. Health behaviors of customers were similar to national data. The surveyed medical center farmers’ markets currently serve mostly employees; however, markets have significant potential for community outreach efforts in preventive medicine. If farmers’ markets can broaden their reach to more diverse populations, they may play an important role in contributing to community health. PMID:24421001

Optical Interconnects for Future Data Center Networks

CERN Document Server

Bergman, Keren; Tomkos, Ioannis

2013-01-01

Optical Interconnects for Future Data Center Networks covers optical networks and how they can provide high bandwidth, energy efficient interconnects with increased communication bandwidth. This volume, with contributions from leading researchers in the field, presents an integrated view of the expected future requirements of data centers and serves as a reference for some of the most advanced and promising solutions proposed by researchers from leading universities, research labs, and companies. The work also includes several novel architectures, each demonstrating different technologies such as optical circuits, optical switching, MIMO optical OFDM, and others. Additionally, Optical Interconnects for Future Data Center Networks provides invaluable insights into the benefits and advantages of optical interconnects and how they can be a promising alternative for future data center networks.

Small Business Development Center

Data.gov (United States)

Small Business Administration — Small Business Development Centers (SBDCs) provide assistance to small businesses and aspiring entrepreneurs throughout the United States and its territories. SBDCs...

Center for Women Veterans

Science.gov (United States)

... Business with VA Acquisition, Logistics, & Construction Small & Veteran Business Programs VetBiz.gov Financial & Asset Enterprise Management Security Investigation Center/Background Clearances Freedom of Information ...

Electron Microscopy Center (EMC)

Data.gov (United States)

Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

Test Control Center (TCC)

Data.gov (United States)

Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...

Student-Centered Instruction in a Theoretical Statistics Course

Science.gov (United States)

Bates Prins, Samantha C.

2009-01-01

This paper provides an example of how student-centered instruction can be used in a theoretical statistics class. The author taught a two-semester undergraduate probability and mathematical statistics sequence using primarily teacher-centered instruction in the first semester and primarily student-centered instruction in the second semester. A…

The Worker Center Movement and Traditional Labor Laws:

OpenAIRE

Naduris-Weissman, Eli

2007-01-01

A new crop of worker advocacy organizations has grown up in the last decade, and has coalesced into an organizational form known as the “worker center.” Just as worker centers have tended to shy away from utilizing NLRB processes to protect worker rights, the status of worker centers under the NLRA has remained cloudy and subject to debate. Specifically, the NLRB and the courts have not addressed whether organizations like worker centers, which seek to improve the lot of employees in margin...

Development and Testing of the Glenn Research Center Visitor's Center Grid-Tied Photovoltaic Power System

Science.gov (United States)

Eichenberg, Dennis J.

2009-01-01

The NASA Glenn Research Center (GRC) has developed, installed, and tested a 12 kW DC grid-tied photovoltaic (PV) power system at the GRC Visitor s Center. This system utilizes a unique ballast type roof mount for installing the photovoltaic panels on the roof of the Visitor s Center with no alterations or penetrations to the roof. The PV system has generated in excess of 15000 kWh since operation commenced in August 2008. The PV system is providing power to the GRC grid for use by all. Operation of the GRC Visitor s Center PV system has been completely trouble free. A grid-tied PV power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. The project transfers space technology to terrestrial use via nontraditional partners. GRC personnel glean valuable experience with PV power systems that are directly applicable to various space power systems, and provides valuable space program test data. PV power systems help to reduce harmful emissions and reduce the Nation s dependence on fossil fuels. Power generated by the PV system reduces the GRC utility demand, and the surplus power aids the community. Present global energy concerns reinforce the need for the development of alternative energy systems. Modern PV panels are readily available, reliable, efficient, and economical with a life expectancy of at least 25 years. Modern electronics has been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy of at least 25 years. Based upon the success of the GRC Visitor s Center PV system, additional PV power system expansion at GRC is under consideration. The GRC Visitor s Center grid-tied PV power system was successfully designed and developed which served to validate the basic principles

Cloud data centers and cost modeling a complete guide to planning, designing and building a cloud data center

CERN Document Server

Wu, Caesar

2015-01-01

Cloud Data Centers and Cost Modeling establishes a framework for strategic decision-makers to facilitate the development of cloud data centers. Just as building a house requires a clear understanding of the blueprints, architecture, and costs of the project; building a cloud-based data center requires similar knowledge. The authors take a theoretical and practical approach, starting with the key questions to help uncover needs and clarify project scope. They then demonstrate probability tools to test and support decisions, and provide processes that resolve key issues. After laying a foundati

Climate Prediction Center - The ENSO Cycle

Science.gov (United States)

Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Home Site Map News Web resources and services. HOME > El Niño/La Niña > The ENSO Cycle ENSO Cycle Banner Climate for Weather and Climate Prediction Climate Prediction Center 5830 University Research Court College

Color centers in KCN: a structural analysis of crystalline domains

International Nuclear Information System (INIS)

Carmo, L.C.S. do.

1976-03-01

Pure singlecrystals of KCN exposed to X-rays showed several color centers detected by EPR. The F center was identified through the correlation of its optical absorption band which satisfies the Ivey law for the KCN lattice parameter and the EPR spectrum typical of a center in an anionic site. Two other color centers were identified: N - 2 and HCN - . Two centers assigned to hydrogen atoms have their models proposed: U 2 and U 3 centers. Two other centers remain unidentified: an anionic and an extrinsic centers. The orthorhombic character of the N - 2 center EPR parameters allowed an structural analysis of the crystal line domains in the orthorhombic phase. The optical absorption spectrum of the HCN - center in KCl matrix was investigated and showed a set of resolved bands with a constant energy splitting; this splitting was associated to a vibrational mode of the excited state of this molecular ion. (author) [pt

Consistent guiding center drift theories

International Nuclear Information System (INIS)

Wimmel, H.K.

1982-04-01

Various guiding-center drift theories are presented that are optimized in respect of consistency. They satisfy exact energy conservation theorems (in time-independent fields), Liouville's theorems, and appropriate power balance equations. A theoretical framework is given that allows direct and exact derivation of associated drift-kinetic equations from the respective guiding-center drift-orbit theories. These drift-kinetic equations are listed. Northrop's non-optimized theory is discussed for reference, and internal consistency relations of G.C. drift theories are presented. (orig.)

Telework centers as local development

OpenAIRE

Lorentzen, Anne

2013-01-01

This paper discusses the establishment of distant work centers as an element in local development strategies in rural areas with a particular view on two new telework centers in Region North DenmarkDistant work is a phenomenon on the rise, due to the development of the internet on the one hand and new flexible work functions on the other hand. Not only the exchange of documents, but also meetings can be organized virtually by still better video conference equipment and programs. An implicatio...

The Aube Center evaluation 2002

International Nuclear Information System (INIS)

2003-01-01

During the meeting of the information local commission, organized the 7 may 2003, the ANDRA took stock on the Aube Center activities during the year 2002. These activities presented in the document concern: the stability of the wastes packages, the personnel safety, the environmental survey, the authorizations of releases, the public information, some data on the exploitation the environment and the radiation protection and a presentation of the storage Center of Morvilliers devoted to the storage of low activity wastes. (A.L.B.)

The 10th Anniversary Of Daejeon Environmental Technology Development Center

International Nuclear Information System (INIS)

2010-12-01

This book describes the Daejeon Environment Technology Development Center with pictures for ten years. It also introduces the purpose of the foundation and background of center, structure of the center, main project and role of the center, center logo, current situation of cost of project, research business for 10 years, business supporting the environmental corporate, environment education, public relations activity and vision and prospect of the Daejeon Environmental Technology Development Center.

14 CFR 25.27 - Center of gravity limits.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Center of gravity limits. 25.27 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.27 Center of gravity limits. The extreme forward and the extreme aft center of gravity limitations must be established for each practicably...

How To Pick a Special Day Care Center.

Science.gov (United States)

Colbert, Ronald P.

This paper outlines seven specific areas that parents should examine when visiting a prospective child care center for their child. Parents should examine: (1) the center's staff; (2) the center's parent relations; (3) the physical and teaching environment; (4) the curriculum; (5) staff-child interaction; (6) the administration; and (7) their…

Radioactive waste management centers: an approach

International Nuclear Information System (INIS)

Lotts, A.L.

1980-01-01

Radioactive waste management centers would satisfy the need for a cost-effective, sound management system for nuclear wastes by the industry and would provide a well integrated solution which could be understood by the public. The future demands for nuclear waste processing and disposal by industry and institutions outside the United States Government are such that a number of such facilities are required between now and the year 2000. Waste management centers can be organized around two general needs in the commercial sector: (1) the need for management of low-level waste generated by nuclear power plants, the once-through nuclear fuel cycle production facilities, from hospitals, and other institutions; and (2) more comprehensive centers handling all categories of nuclear wastes that would be generated by a nuclear fuel recycle industry. The basic technology for radioactive waste management will be available by the time such facilities can be deployed. This paper discusses the technical, economic, and social aspects of organizing radioactive waste managment centers and presents a strategy for stimulating their development

Barriers and facilitators to implementing a patient-centered model of contraceptive provision in community health centers.

Science.gov (United States)

Politi, Mary C; Estlund, Amy; Milne, Anne; Buckel, Christina M; Peipert, Jeffrey F; Madden, Tessa

2016-01-01

The Contraceptive CHOICE Project developed a patient-centered model for contraceptive provision including: (1) structured, evidence-based counseling; (2) staff and health care provider education; and (3) removal of barriers such as cost and multiple appointments to initiate contraception. In preparation for conducting a research study of the CHOICE model in three community health settings, we sought to identify potential barriers and facilitators to implementation. Using a semi-structured interview guide guided by a framework of implementation research, we conducted 31 qualitative interviews with female patients, staff, and health care providers assessing attitudes, beliefs, and barriers to receiving contraception. We also asked about current contraceptive provision and explored organizational practices relevant to implementing the CHOICE model. We used a grounded theory approach to identify major themes. Many participants felt that current contraceptive provision could be improved by the CHOICE model. Potential facilitators included agreement about the necessity for improved contraceptive knowledge among patients and staff; importance of patient-centered contraceptive counseling; and benefits to same-day insertion of long-acting reversible contraception (LARC). Potential barriers included misconceptions about contraception held by staff and providers; resistance to new practices; costs associated with LARC; and scheduling challenges required for same-day insertion of LARC. In addition to staff and provider training, implementing a patient-centered model of contraceptive provision needs to be supplemented by strategies to manage patient and system-level barriers. Community health center staff, providers, and patients support patient-centered contraceptive counseling to improve contraception provision if organizations can address these barriers.

Center for Food Safety and Applied Nutrition

Data.gov (United States)

Federal Laboratory Consortium — The Center for Food Safety and Applied Nutrition, known as CFSAN, is one of six product-oriented centers, in addition to a nationwide field force, that carry out the...

Slow recombination centers in cadmium selenide monocrystalline films

International Nuclear Information System (INIS)

Smyntyna, V.A.

1983-01-01

As a result of annealing when concentration of selenium Vacancies decreases due to their diffusion towards the surface, show recombination K-centers begin to influence the photoelectric properties of monocrystalline cadmium selenide layers. Energy levels of K-centers are located by 0.23-0.25 eV over the valent zone ceiling. The nature of K-centers is determined by the presence in the cadmium selenide layer structure of intrisic defects-cadmium vacancies in contrast to r-centers of slow recombination which are bound with impurities in a semiconductor material

NASA Langley Research Center outreach in astronautical education

Science.gov (United States)

Duberg, J. E.

1976-01-01

The Langley Research Center has traditionally maintained an active relationship with the academic community, especially at the graduate level, to promote the Center's research program and to make graduate education available to its staff. Two new institutes at the Center - the Joint Institute for Acoustics and Flight Sciences, and the Institute for Computer Applications - are discussed. Both provide for research activity at the Center by university faculties. The American Society of Engineering Education Summer Faculty Fellowship Program and the NASA-NRC Postdoctoral Resident Research Associateship Program are also discussed.

Clean Energy Solutions Center Services (Vietnamese Translation) (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2014-11-01

This is the Vietnamese language translation of the Clean Energy Solutions Center (Solutions Center) fact sheet. The Solutions Center helps governments, advisors and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center partners with international organizations to provide online training, expert assistance, and technical resources on clean energy policy.

Clean Energy Solutions Center Services (Arabic Translation) (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2014-06-01

This is the Arabic translation of the Clean Energy Solutions Center Services fact sheet. The Clean Energy Solutions Center (Solutions Center) helps governments, advisors and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center partners with international organizations to provide online training, expert assistance, and technical resources on clean energy policy.

Distribution of specialized care centers in the United States.

Science.gov (United States)

Wang, Henry E; Yealy, Donald M

2012-11-01

As a recommended strategy for optimally managing critical illness, regionalization of care involves matching the needs of the target population with available hospital resources. The national supply and characteristics of hospitals providing specialized critical care services is currently unknown. We seek to characterize the current distribution of specialized care centers in the United States. Using public data linked with the American Hospital Association directory and US Census, we identified US general acute hospitals providing specialized care for ST-segment elevation myocardial infarction (STEMI) (≥40 annual primary percutaneous coronary interventions reported in Medicare Hospital Compare), stroke (The Joint Commission certified stroke centers), trauma (American College of Surgeons or state-designated, adult or pediatric, level I or II), and pediatric critical care (presence of a pediatric ICU) services. We determined the characteristics and state-level distribution and density of specialized care centers (centers per state and centers per state population). Among 4,931 acute care hospitals in the United States, 1,325 (26.9%) provided one of the 4 defined specialized care services, including 574 STEMI, 763 stroke, 508 trauma, and 457 pediatric critical care centers. Approximately half of the 1,325 hospitals provided 2 or more specialized services, and one fifth provided 3 or 4 specialized services. There was variation in the number of each type of specialized care center in each state: STEMI median 7 interquartile range (IQR 2 to 14), stroke 8 (IQR 3 to 17), trauma 6 (IQR 3 to 11), pediatric specialized care 6 (IQR 3 to 11). Similarly, there was variation in the number of each type of specialized care center per population: STEMI median 1 center per 585,135 persons (IQR 418,729 to 696,143), stroke 1 center per 412,188 persons (IQR 321,604 to 572,387), trauma 1 center per 610,589 persons (IQR 406,192 to 917,588), and pediatric critical care 1 center per 665

Structural Analysis Peer Review for the Static Display of the Orbiter Atlantis at the Kennedy Space Center Visitors Center

Science.gov (United States)

Minute, Stephen A.

2013-01-01

Mr. Christopher Miller with the Kennedy Space Center (KSC) NASA Safety & Mission Assurance (S&MA) office requested the NASA Engineering and Safety Center's (NESC) technical support on March 15, 2012, to review and make recommendations on the structural analysis being performed for the Orbiter Atlantis static display at the KSC Visitor Center. The principal focus of the assessment was to review the engineering firm's structural analysis for lifting and aligning the orbiter and its static display configuration

Chemical Security Analysis Center

Data.gov (United States)

Federal Laboratory Consortium — In 2006, by Presidential Directive, DHS established the Chemical Security Analysis Center (CSAC) to identify and assess chemical threats and vulnerabilities in the...

Center for Deployment Psychology

Data.gov (United States)

Federal Laboratory Consortium — The Center for Deployment Psychology was developed to promote the education of psychologists and other behavioral health specialists about issues pertaining to the...

Facile and reversible formation of iron(III)-oxo-cerium(IV) adducts from nonheme oxoiron(IV) complexes and cerium(III)

Energy Technology Data Exchange (ETDEWEB)

Draksharapu, Apparao; Rasheed, Waqas; Klein, Johannes E.M.N.; Que, Lawrence Jr. [Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN (United States)

2017-07-24

Ceric ammonium nitrate (CAN) or Ce{sup IV}(NH{sub 4}){sub 2}(NO{sub 3}){sub 6} is often used in artificial water oxidation and generally considered to be an outer-sphere oxidant. Herein we report the spectroscopic and crystallographic characterization of [(N4Py)Fe{sup III}-O-Ce{sup IV}(OH{sub 2})(NO{sub 3}){sub 4}]{sup +} (3), a complex obtained from the reaction of [(N4Py)Fe{sup II}(NCMe)]{sup 2+} with 2 equiv CAN or [(N4Py)Fe{sup IV}=O]{sup 2+} (2) with Ce{sup III}(NO{sub 3}){sub 3} in MeCN. Surprisingly, the formation of 3 is reversible, the position of the equilibrium being dependent on the MeCN/water ratio of the solvent. These results suggest that the Fe{sup IV} and Ce{sup IV} centers have comparable reduction potentials. Moreover, the equilibrium entails a change in iron spin state, from S=1 Fe{sup IV} in 2 to S=5/2 in 3, which is found to be facile despite the formal spin-forbidden nature of this process. This observation suggests that Fe{sup IV}=O complexes may avail of reaction pathways involving multiple spin states having little or no barrier. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Nuclear Data Center International Standard Towards TSO Initiative

International Nuclear Information System (INIS)

Raja Murzaferi Raja Moktar; Mohd Fauzi Haris; Siti Nurbahyah Hamdan

2011-01-01

Nuclear Data Center is the main facility for Nuclear Malaysia Agency IT infrastructure comprising of main critical servers, research and operational data storage, HPC-clusters system and vital network core equipment. In recent years, international body such as TIA-Telecommunication Industry Association and Up time Institute have came out with proper international data center standards in order to ensure data center operation on achieving maximum operational up time and minimal downtime. The standard are currently being rated as tier level ranging from Data Center tier I up to tier IV, differentiate by facility standard and up time/ downtime percentage ratio. This paper will discuss Nuclear Data Center adopting international standards in supporting Nuclear Malaysia TSO initiative thus ensuring the critical core component of agency IT services availability and further more International standard recognitions. (author)

2011 Las Conchas Post Fire Center Index

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — This data set consists of photo centers of raw aerial images representing multi-spectral (red, green, blue, near-infrared) digital aerial imagery of the Las Conchas...

Strategic Project Management at the NASA Kennedy Space Center

Science.gov (United States)

Lavelle, Jerome P.

2000-01-01

This paper describes Project Management at NASA's Kennedy Space Center (KSC) from a strategic perspective. It develops the historical context of the agency and center's strategic planning process and illustrates how now is the time for KSC to become a center which has excellence in project management. The author describes project management activities at the center and details observations on those efforts. Finally the author describes the Strategic Project Management Process Model as a conceptual model which could assist KSC in defining an appropriate project management process system at the center.

Center for Contaminated Sediments

Data.gov (United States)

Federal Laboratory Consortium — The U.S. Army Corps of Engineers Center for Contaminated Sediments serves as a clearinghouse for technology and expertise concerned with contaminated sediments. The...

National Automotive Center - NAC

Data.gov (United States)

Federal Laboratory Consortium — Encouraged by the advantages of collaboration, the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC) worked with the Secretary of the...

Great Lakes Science Center

Data.gov (United States)

Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

Inside a Postpartum Nursing Center: Tradition and Change.

Science.gov (United States)

Yeh, Yueh-Chen; St John, Winsome; Venturato, Lorraine

2016-06-01

The purpose of this study was to explore how traditional ritual practices are incorporated into the context of contemporary healthcare. An ethnographic study was conducted, using observations and interviews with 27 first-time mothers and 3 nurses at a postpartum nursing center in Taipei, Taiwan. Nursing routines, policies and care provision at the center affected the way traditional ritual practices were conducted. New mothers in this study constructed their everyday activities at the center by incorporating and modifying the ritual practices inside and outside the postpartum nursing center setting. Social changes have an influence on traditional postpartum ritual practices so a postpartum nursing center becomes a choice for postpartum women. Thus, health care professionals should value their own functions and roles at the postpartum nursing center since the new mothers regard them as the primary support resource to help them recover from giving birth. Therefore, they need to re-examine their practices from the postpartum women's perspective to provide better support and sensitive care to postpartum women and their families. Copyright © 2016. Published by Elsevier B.V.

Analysis of Business Center Implementation in Banyumas Regency

Directory of Open Access Journals (Sweden)

Lina Rifda Naufalin

2017-06-01

Full Text Available The research aims to help the development of business center as an entrepreneurship laboratory for vocational students in order to increase the number of young entrepreneurs in Indonesia. This study is also  to find out how the implementation of the existing Business Center program in SMK Banyumas District viewed from the aspects of learning, economics, organizational, and capital. Research method used qualitative method and techniques of collecting data used observation and interview. The place of research is in Vocational School 1 Purwokerto and Vocational School 2 Purwokerto. The sampling technique was purposive sampling technique. Validity of data in this research used data triangulation.The result of the research shows that the learning aspect of the implementation of the business center is effective because it becomes the student training center. Economic aspect of the business center is effective to carry out the activities of selling goods, goods production and service, business because it is supported by qualified human resources and internal audits conducted regularly. The aspect of the capital of the business center can be managed effectively.

Study of black carbon levels in city centers and industrial centers in Jordan

International Nuclear Information System (INIS)

Hamasha, K.M.; Almomani, M.S.; Abu-Allaban, M.; Arnott, W. P.

2010-01-01

Light absorption coefficients of black carbon (B abc ) were measured at serveral urban and industrial locations in Jordan during summer of 2007 and winter of 2008 using the photoacoustic instrument at a wavelength of 870 nm. Black carbon mass concentration (BC) was calculated using B abc .Black carbon levels at urban locations in the summer of 2007 were higher than those obtained at industrial centers.Zarqa had the highest value of BC in summer (29.24μg/m 3 ) and in winter (13.27μg/m 3 ). Ibbeen and Irbid city center had relatively high values of BC in winter: 11.75μg/m 3 and 12.48μg/m 3 , respectively. (authors).

Human-centered incubator: beyond a design concept

OpenAIRE

Goossens, R H M; Willemsen, H

2013-01-01

We read with interest the paper by Ferris and Shepley1 on a human-centered design project with university students on neonatal incubators. It is interesting to see that in the design solutions and concepts as presented by Ferris and Shepley,1 human-centered design played an important role. In 2005, a master thesis project was carried out in the Delft University of Technology, following a similar human-centered design approach.2, 3 In that design project we also addressed the noise level insid...

Advanced Missile Signature Center

Data.gov (United States)

Federal Laboratory Consortium — The Advanced Missile Signature Center (AMSC) is a national facility supporting the Missile Defense Agency (MDA) and other DoD programs and customers with analysis,...

Nuclear energy center site survey reactor plant considerations

International Nuclear Information System (INIS)

1976-05-01

The Energy Reorganization Act of 1974 required the Nuclear Regulatory Commission (NRC) to make a nuclear energy center site survey (NECSS). Background information for the NECSS report was developed in a series of tasks which include: socioeconomic inpacts; environmental impact (reactor facilities); emergency response capability (reactor facilities); aging of nuclear energy centers; and dry cooled nuclear energy centers

A Cost Analysis of Day Care Centers in Pennsylvania. Center for Human Service Development Report No. 21.

Science.gov (United States)

Hu, Teh-Wei; Wise, Karl

The purpose of this study is to provide day care center management and government funding agencies with empirical estimates of the costs of day care centers in Pennsylvania. Based on cost data obtained from the Department of Public Welfare and survey information from the Pennsylvania Day Care Study Project, average and marginal costs of day care…

Centering mount for a gamma camera

International Nuclear Information System (INIS)

Mirkhodzhaev, A.Kh.; Kuznetsov, N.K.; Ostryj, Yu.E.

1988-01-01

A device for centering a γ-camera detector in case of radionuclide diagnosis is described. It permits the use of available medical coaches instead of a table with a transparent top. The device can be used for centering a detector (when it is fixed at the low end of a γ-camera) on a required area of the patient's body

Lactoferrin targets T cells in the small intestine

DEFF Research Database (Denmark)

Nielsen, Sanne Mie; Hansen, Gert Helge; Danielsen, E Michael

2010-01-01

BACKGROUND: Lactoferrin (Lf) belongs to the transferrin family of non-heme iron-binding proteins and is found in milk and mucosal secretions. Consequently, it is now considered a multifunctional protein mainly involved in both the innate and adaptive immune defenses of the organism against various...... explants of pig small intestine by immunofluorescence and immunogold microscopy. RESULTS: Lf rapidly bound to the brush border and subsequently appeared in punctae in the apical cytoplasm, indicating internalization into an endosomal compartment. Essentially, no labeling was detected elsewhere...

Electrochemically Generated cis-Carboxylato-Coordinated Iron(IV) Oxo Acid-Base Congeners as Promiscuous Oxidants of Water Pollutants

DEFF Research Database (Denmark)

de Sousa, David P; Miller, Christopher J; Chang, Yingyue

2017-01-01

The nonheme iron(IV) oxo complex [FeIV(O)(tpenaH)]2+ and its conjugate base [FeIV(O)(tpena)]+ [tpena- = N,N,N'-tris(2-pyridylmethyl)ethylenediamine-N'-acetate] have been prepared electrochemically in water by bulk electrolysis of solutions prepared from [FeIII2(μ-O)(tpenaH)2](ClO4)4 at potentials...... of the electrochemically generated iron(IV) oxo complexes, in terms of the broad range of substrates examined, represents an important step toward the goal of cost-effective electrocatalytic water purification....

Muonium centers in the alkali halides

International Nuclear Information System (INIS)

Baumeler, H.; Kiefl, R.F.; Keller, H.; Kuendig, W.; Odermatt, W.; Patterson, B.D.; Schneider, J.W.; Savic, I.M.

1986-01-01

Muonium centers (Mu) in single crystals and powdered alkali halides have been studied using the high-timing-resolution transverse field μSR technique. Mu has been observed and its hyperfine parameter (HF) determined in every alkali halide. For the rocksalt alkali halides, the HF parameter A μ shows a systematic dependence on the host lattice constant. A comparison of the Mu HF parameter with hydrogen ESR data suggests that the Mu center is the muonic analogue of the interstitial hydrogen H i 0 -center. The rate of Mu diffusion can be deduced from the motional narrowing of the nuclear hyperfine interaction. KBr shows two different Mu states, a low-temperature Mu I -state and a high-temperature Mu II -state. (orig.)

MacMillan Pier Transportation Center Feasibility Study.

Science.gov (United States)

2006-06-01

The MacMillan Pier Transportation Center Feasibility Study examines two potential sites (landside and waterside) for a transportation center that provides a range of tourist and traveler information. It would serve as a gateway for Provincetown and t...

Shopping Malls - ShoppingCenters

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — Collected from a variety of sources both commercial and internal, this layer represents shopping center locations within Volusia County and is maintained by the...

- Oklahoma Water Resources Center

Science.gov (United States)

Development Ag Business Community & Rural Development Crops Family & Consumer Sciences Gardening Family & Consumer Sciences Food & Ag Products Center Horticulture & Landscape Architecture & Landscape Architecture Natural Resource Ecology & Management Plant & Soil Sciences

User-Centered Evaluation of Visual Analytics

Energy Technology Data Exchange (ETDEWEB)

Scholtz, Jean C.

2017-10-01

Visual analytics systems are becoming very popular. More domains now use interactive visualizations to analyze the ever-increasing amount and heterogeneity of data. More novel visualizations are being developed for more tasks and users. We need to ensure that these systems can be evaluated to determine that they are both useful and usable. A user-centered evaluation for visual analytics needs to be developed for these systems. While many of the typical human-computer interaction (HCI) evaluation methodologies can be applied as is, others will need modification. Additionally, new functionality in visual analytics systems needs new evaluation methodologies. There is a difference between usability evaluations and user-centered evaluations. Usability looks at the efficiency, effectiveness, and user satisfaction of users carrying out tasks with software applications. User-centered evaluation looks more specifically at the utility provided to the users by the software. This is reflected in the evaluations done and in the metrics used. In the visual analytics domain this is very challenging as users are most likely experts in a particular domain, the tasks they do are often not well defined, the software they use needs to support large amounts of different kinds of data, and often the tasks last for months. These difficulties are discussed more in the section on User-centered Evaluation. Our goal is to provide a discussion of user-centered evaluation practices for visual analytics, including existing practices that can be carried out and new methodologies and metrics that need to be developed and agreed upon by the visual analytics community. The material provided here should be of use for both researchers and practitioners in the field of visual analytics. Researchers and practitioners in HCI and interested in visual analytics will find this information useful as well as a discussion on changes that need to be made to current HCI practices to make them more suitable to

Energy efficient thermal management of data centers

CERN Document Server

Kumar, Pramod

2012-01-01

Energy Efficient Thermal Management of Data Centers examines energy flow in today's data centers. Particular focus is given to the state-of-the-art thermal management and thermal design approaches now being implemented across the multiple length scales involved. The impact of future trends in information technology hardware, and emerging software paradigms such as cloud computing and virtualization, on thermal management are also addressed. The book explores computational and experimental characterization approaches for determining temperature and air flow patterns within data centers. Thermodynamic analyses using the second law to improve energy efficiency are introduced and used in proposing improvements in cooling methodologies. Reduced-order modeling and robust multi-objective design of next generation data centers are discussed. This book also: Provides in-depth treatment of energy efficiency ideas based on  fundamental heat transfer, fluid mechanics, thermodynamics, controls, and computer science Focus...

Mathematical Model of Synthesis Catalyst with Local Reaction Centers

Directory of Open Access Journals (Sweden)

I. V. Derevich

2017-01-01

Full Text Available The article considers a catalyst granule with a porous ceramic passive substrate and point active centers on which an exothermic synthesis reaction occurs. A rate of the chemical reaction depends on the temperature according to the Arrhenius law. Heat is removed from the pellet surface in products of synthesis due to heat transfer. In our work we first proposed a model for calculating the steady-state temperature of a catalyst pellet with local reaction centers. Calculation of active centers temperature is based on the idea of self-consistent field (mean-field theory. At first, it is considered that powers of the reaction heat release at the centers are known. On the basis of the found analytical solution, which describes temperature distribution inside the granule, the average temperature of the reaction centers is calculated, which then is inserted in the formula for heat release. The resulting system of transcendental algebraic equations is transformed into a system of ordinary differential equations of relaxation type and solved numerically to achieve a steady-state value. As a practical application, the article considers a Fischer-Tropsch synthesis catalyst granule with active cobalt metallic micro-particles. Cobalt micro-particles are the centers of the exothermic reaction of hydrocarbons macromolecular synthesis. Synthesis occurs as a result of absorption of the components of the synthesis gas on metallic cobalt. The temperature distribution inside the granule for a single local center and reaction centers located on the same granule diameter is found. It was found that there is a critical temperature of reactor exceeding of which leads to significant local overheating of the centers - thermal explosion. The temperature distribution with the local reaction centers is qualitatively different from the granule temperature, calculated in the homogeneous approximation. It is shown that, in contrast to the homogeneous approximation, the

Crib Information Center

Science.gov (United States)

... 한국어 Español ภาษาไทย Tiếng Việt Text Size: Decrease Font Increase Font Contact CPSC Consumers: Businesses: Report an Unsafe Product ... Department of Health (HRSA) NICHD text4baby ")); jQuery(".node-type-safety-education-center .region-sidebar-second").css('display', " ...

Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases, Fiscal Year 2002 Annual Report

Energy Technology Data Exchange (ETDEWEB)

Cushman, R.M.

2003-08-28

The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including atmospheric concentrations and atmospheric emissions of carbon dioxide (CO{sub 2}) and other radiatively active gases; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

Integrating heterogeneous healthcare call centers.

Science.gov (United States)

Peschel, K M; Reed, W C; Salter, K

1998-01-01

In a relatively short period, OHS has absorbed multiple call centers supporting different LOBs from various acquisitions, functioning with diverse standards, processes, and technologies. However, customer and employee satisfaction is predicated on OHS's ability to thoroughly integrate these heterogeneous call centers. The integration was initiated and has successfully progressed through a balanced program of focused leadership and a defined strategy which includes site consolidation, sound performance management philosophies, and enabling technology. Benefits have already been achieved with even more substantive ones to occur as the integration continues to evolve.

Financing of certified centers: a willingness-to-pay analysis.

Science.gov (United States)

Thiel, Falk C; Scharl, Anton; Hildebrandt, Thomas; Kotziabassis, Efstratios; Schrauder, Michael G; Bani, Mayada R; Müller, Andreas; Hauzenberger, Tanja; Loehberg, Christian R; Jud, Sebastian M; Fasching, Peter A; Hartmann, Arndt; Schulz-Wendtland, Rüdiger; Strnad, Vratislav; Beckmann, Matthias W; Lux, Michael Patrick

2013-03-01

Although care in certified breast centers is now established throughout Germany, numerous services are still not being reimbursed. This also affects other centers involved in the specialty of gynecology such as gynecological cancer centers, perinatal centers, and endometriosis centers. Although a certified center is entitled to charge additional fees, these are in most cases not reimbursed. Calculation of additional costs is limited by the fact that data from the Institute for the Hospital Reimbursement System (Institut für das Entgeltsystem im Krankenhaus, InEK) do not reflect interdisciplinary services and procedures. For decision-makers, society's willingness to pay is an important factor in guiding decisions on the basis of social priorities. A hypothetical maximum willingness to pay can be calculated using a willingness-to-pay analysis, making it possible to identify deficiencies in the arbitrary setting of health budgets at the macro-level. In a multicenter study conducted between November 2009 and December 2010, 2,469 patients at a university hospital and at a non-university hospital were asked about the extent of their awareness of certified centers, the influence of centers on hospital presentation, and about personal attitudes toward quality-oriented reimbursement. A subjective assessment of possible additional charges was calculated using a willingness-to-pay analysis. In the overall group, 53.4 % of the patients were aware of what a certified center is and 27.4 % had specific information (obstetrics 40.0/32.3 %; mastology 66.8/23.2 %; gynecological oncology 54.7/27.3 %; P < 0.001). For 43.8 %, a certified center was one reason or the major reason for presentation (obstetrics 26.2 %; mastology 66.8 %; gynecological oncology 46.6 %; P < 0.001). A total of 72.6 % were in favor of quality-oriented reimbursement and 69.7 % were in favor of an additional charge for a certified center amounting to €538.56 (mastology €643.65, obstetrics €474

Rehabilitation centers: marketing analysis and future challenges.

Science.gov (United States)

Chandra, Ashish; Stroube, William B; Willis, William K

2014-01-01

A rehabilitation center is another form of health care organization that specializes in providing care for particular conditions of patients. Patients admitted in rehab centers range from being accident victims to those suffering with a specific illness. These organizations are becoming extremely valuable in providing patient care services. However, they have not marketed themselves as aggressively as other health care organizations. This article provides an insight regarding rehab centers and examines marketing issues using a SWOT (strengths, weaknesses, opportunities, and threats) analysis. It further provides some future prospects and challenges for marketers of these organizations.

Issues at a university based FEL center

International Nuclear Information System (INIS)

Smith, T.I.; Schwettman, H.A.

1998-01-01

The Stanford FEL Center was established in September 1990. In this paper, the FEL itself, the Center infrastructure, the interaction with experimenters and the educational mission are described. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

A Comparison of Organization-Centered and Agent-Centered Multi-Agent Systems

DEFF Research Database (Denmark)

Jensen, Andreas Schmidt; Villadsen, Jørgen

2013-01-01

Whereas most classical multi-agent systems have the agent in center, there has recently been a development towards focusing more on the organization of the system, thereby allowing the designer to focus on what the system goals are, without considering how the goals should be fulfilled. We have d...

Advanced Cancer Detection Center

National Research Council Canada - National Science Library

Ruckdeschel, John

1999-01-01

... through screening, and the testing of methods to prevent cancer. In addition, the Center created and supports education programs to provide increased cancer awareness and established working collaborations with the James...

WomenÕs Advancement in the Accounting Profession: Consideration of Person-Centered and Organization-Centered Explanations

OpenAIRE

Janet S. Omundson; Richard G. Schroeder; Mary B. Stevens

1997-01-01

Today, communication skills are among the most popular content areas in employee training. This survey of training managers examined the status of communication training in businesDespite the entry of large numbers of women into the accounting profession over the last decade, few women have reached top management levels. Two alternative paradigms that attempt to explain this phenomenon are the person-centered explanation and the organization-centered explanation. This study explores the Type ...

Magnetic Monopoles, Center Vortices and Topology of Gauge Fields

OpenAIRE

Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schafke, A.

1999-01-01

The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed.

Magnetic monopoles, center vortices and topology of gauge fields

International Nuclear Information System (INIS)

Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schaefke, A.

2000-01-01

The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed

Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.

Directory of Open Access Journals (Sweden)

Maryse C Cnossen

Full Text Available The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI is low. Comparative effectiveness research (CER has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI study.We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions.All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%, designated as a level I trauma center (n = 48, 68% and situated in an urban location (n = 70, 99%. The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57% had a dedicated neuro-intensive care unit (ICU, 36 (51% had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45 of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers.Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches.

DX centers in indium aluminum arsenide heterostructures

Science.gov (United States)

Sari, Huseyin

DX centers are point defects observed in many n-type doped III-V compound semi conductors. They have unique properties, which include large differences between their optical and thermal ionization energies, and a temperature dependence of the capture cross-sections. As a result of these properties DX centers exhibit a reduction in free carrier concentration and a large persistent photoconductivity (PPC) effect. DX centers also lead to a shift in the threshold voltage of modulation doped field effect transistors (MODFET) structures, at low temperatures. Most of the studies on this defect have been carried out on the Ga xAl1-xAs material system. However, to date there is significantly less work on DX centers in InxAl1-xAs compounds. This is partly due to difficulties associated with the growth of defect free materials other than lattice matched In0.52Al 0.48As on InP and partly because the energy level of the DX center is in resonance with the conduction band in In0.52Al0.48As. The purpose of this dissertation is to extend the DX center investigation to InAlAs compounds, primarily in the indirect portion of the InAlAs bandgap. In this work the indium composition dependence of the DX centers in In xAl1-xAs/InyGa1-yAs-based heterostructure is studied experimentally. Different InxAl 1-xAs epitaxial layers with x = 0.10, x = 0.15, x = 0.20, and x = 0.34 in a MODFET-like heterostructure were grown by Molecular Beam Epitaxy (MBE) on (001) GaAs substrates. In order to compensate the lattice mismatch between epitaxial layers and their substrates, step-graded buffer layers with indium composition increments of x = 0.10, every 2000 A, were used. For the samples grown with different indium contents Hall measurements as a function of both temperature and different cooling biases were performed in order to determine their carrier concentrations. A self consistent Poisson-Schrodinger numerical software is used to model the heterostructures. With the help of this numerical model

Activity report of Computing Research Center

Energy Technology Data Exchange (ETDEWEB)

1997-07-01

On April 1997, National Laboratory for High Energy Physics (KEK), Institute of Nuclear Study, University of Tokyo (INS), and Meson Science Laboratory, Faculty of Science, University of Tokyo began to work newly as High Energy Accelerator Research Organization after reconstructing and converting their systems, under aiming at further development of a wide field of accelerator science using a high energy accelerator. In this Research Organization, Applied Research Laboratory is composed of four Centers to execute assistance of research actions common to one of the Research Organization and their relating research and development (R and D) by integrating the present four centers and their relating sections in Tanashi. What is expected for the assistance of research actions is not only its general assistance but also its preparation and R and D of a system required for promotion and future plan of the research. Computer technology is essential to development of the research and can communize for various researches in the Research Organization. On response to such expectation, new Computing Research Center is required for promoting its duty by coworking and cooperating with every researchers at a range from R and D on data analysis of various experiments to computation physics acting under driving powerful computer capacity such as supercomputer and so forth. Here were described on report of works and present state of Data Processing Center of KEK at the first chapter and of the computer room of INS at the second chapter and on future problems for the Computing Research Center. (G.K.)

[Health centers: history and future prospects.].

Science.gov (United States)

Colin, Marie-Pierre; Acker, Dominique

2009-03-29

Health houses and health centers are often hailed as specifically modern forms of medical practice in mobile healthcare provision. Yet the concept of health center emerged in the seventeenth century. The founding principles of these institutions were to promote access to good-quality universal healthcare and to practice a form of healthcare that treated patients in their globality (i.e. within their social and environmental context) based on public healthcare measures. Though they constitute a response to a specific healthcare project, healthcare centers face a number of specific difficulties that pose a challenge to their durability and development. Payment per consultation is ill-adapted to the remuneration of their services, and methods of remuneration that may be applicable to independent medical practitioners do not apply in the context of health centers, which may struggle to survive without the support of territorial collectivities (i.e. regional and local authorities) or associations. Health houses face similar difficulties in terms of their structural expenses. Expectations are high for trying out new methods of remuneration. The perspective and experience of healthcare centers will likely prove to be essential in this context. Their future needs to be envisaged alongside health houses and medical hubs. The growth of precarity and the increasing difficulties affecting access to healthcare provision need to be taken into account. The choice of the specific type of structure will depend on local realities, on the political will of regional authorities and on the specific projects of healthcare professionals. Yet whatever solution is envisaged, it will not be possible without public funding.

USU Patient Simulation Center

Data.gov (United States)

Federal Laboratory Consortium — he National Capital Area (NCA) Medical Simulation Center is a state-of-the-art training facility located near the main USU campus. It uses simulated patients (i.e.,...