43 CFR 3933.51 - Bond coverage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Bond coverage. 3933.51 Section 3933.51 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Assignments and Subleases § 3933.51 Bond coverage. Before the BLM will approve an assignment, the assignee...

43 CFR 3933.51 - Bond coverage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Bond coverage. 3933.51 Section 3933.51 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... and Subleases § 3933.51 Bond coverage. Before the BLM will approve an assignment, the assignee must...

43 CFR 3933.51 - Bond coverage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Bond coverage. 3933.51 Section 3933.51 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Assignments and Subleases § 3933.51 Bond coverage. Before the BLM will approve an assignment, the assignee...

High Coverages of Hydrogen on a (10,0) Carbon Nanotube

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Arnold, James (Technical Monitor)

2001-01-01

The binding energy of H to a (10,0) carbon nanotube is calculated at 24, 50, and 100% coverage. Several different bonding configurations are considered for the 50% coverage case. Using the ONIOM (our own n-layered integrated molecular orbital and molecular mechanics) approach, the average C-H bond energy for the most stable 50% coverage and for the 100% coverage are 57.3 and 38.6 kcal/mol, respectively. Considering the size of the bond energy of H2, these values suggest that it will be difficult to achieve 100% atomic H coverage on a (10,0) nanotube.

Generalized scaling relationships on transition metals: Influence of adsorbate-coadsorbate interactions

NASA Astrophysics Data System (ADS)

Majumdar, Paulami; Greeley, Jeffrey

2018-04-01

Linear scaling relations of adsorbate energies across a range of catalytic surfaces have emerged as a central interpretive paradigm in heterogeneous catalysis. They are, however, typically developed for low adsorbate coverages which are not always representative of realistic heterogeneous catalytic environments. Herein, we present generalized linear scaling relations on transition metals that explicitly consider adsorbate-coadsorbate interactions at variable coverages. The slopes of these scaling relations do not follow the simple bond counting principles that govern scaling on transition metals at lower coverages. The deviations from bond counting are explained using a pairwise interaction model wherein the interaction parameter determines the slope of the scaling relationship on a given metal at variable coadsorbate coverages, and the slope across different metals at fixed coadsorbate coverage is approximated by adding a coverage-dependent correction to the standard bond counting contribution. The analysis provides a compact explanation for coverage-dependent deviations from bond counting in scaling relationships and suggests a useful strategy for incorporation of coverage effects into catalytic trends studies.

Discrete and polymeric self-assembled dendrimers: Hydrogen bond-mediated assembly with high stability and high fidelity

PubMed Central

Corbin, Perry S.; Lawless, Laurence J.; Li, Zhanting; Ma, Yuguo; Witmer, Melissa J.; Zimmerman, Steven C.

2002-01-01

Hydrogen bond-mediated self-assembly is a powerful strategy for creating nanoscale structures. However, little is known about the fidelity of assembly processes that must occur when similar and potentially competing hydrogen-bonding motifs are present. Furthermore, there is a continuing need for new modules and strategies that can amplify the relatively weak strength of a hydrogen bond to give more stable assemblies. Herein we report quantitative complexation studies on a ureidodeazapterin-based module revealing an unprecedented stability for dimers of its self-complementary acceptoracceptor-donor-donor (AADD) array. Linking two such units together with a semirigid spacer that carries a first-, second-, or third-generation Fréchet-type dendron affords a ditopic structure programmed to self assemble. The specific structure that is formed depends both on the size of the dendron and the solvent, but all of the assemblies have exceptionally high stability. The largest discrete nanoscale assembly is a hexamer with a molecular mass of about 17.8 kDa. It is stabilized by 30 hydrogen bonds, including six AADD⋅DDAA contacts. The hexamer forms and is indefinitely stable in the presence of a hexamer containing six ADD⋅DAA hydrogen-bonding arrays. PMID:11917113

Bonding thermoplastic polymers

DOEpatents

Wallow, Thomas I [Fremont, CA; Hunter, Marion C [Livermore, CA; Krafcik, Karen Lee [Livermore, CA; Morales, Alfredo M [Livermore, CA; Simmons, Blake A [San Francisco, CA; Domeier, Linda A [Danville, CA

2008-06-24

We demonstrate a new method for joining patterned thermoplastic parts into layered structures. The method takes advantage of case-II permeant diffusion to generate dimensionally controlled, activated bonding layers at the surfaces being joined. It is capable of producing bonds characterized by cohesive failure while preserving the fidelity of patterned features in the bonding surfaces. This approach is uniquely suited to production of microfluidic multilayer structures, as it allows the bond-forming interface between plastic parts to be precisely manipulated at micrometer length scales. The bond enhancing procedure is easily integrated in standard process flows and requires no specialized equipment.

7 CFR 1788.49 - Contractors' bond requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE (CONTINUED) RUS FIDELITY AND INSURANCE REQUIREMENTS FOR ELECTRIC AND TELECOMMUNICATIONS BORROWERS Insurance for Contractors, Engineers, and Architects, Telecommunications Borrowers...

7 CFR 1788.49 - Contractors' bond requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF AGRICULTURE (CONTINUED) RUS FIDELITY AND INSURANCE REQUIREMENTS FOR ELECTRIC AND TELECOMMUNICATIONS BORROWERS Insurance for Contractors, Engineers, and Architects, Telecommunications Borrowers...

7 CFR 1788.49 - Contractors' bond requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF AGRICULTURE (CONTINUED) RUS FIDELITY AND INSURANCE REQUIREMENTS FOR ELECTRIC AND TELECOMMUNICATIONS BORROWERS Insurance for Contractors, Engineers, and Architects, Telecommunications Borrowers...

7 CFR 1788.49 - Contractors' bond requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF AGRICULTURE (CONTINUED) RUS FIDELITY AND INSURANCE REQUIREMENTS FOR ELECTRIC AND TELECOMMUNICATIONS BORROWERS Insurance for Contractors, Engineers, and Architects, Telecommunications Borrowers...

7 CFR 1788.49 - Contractors' bond requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF AGRICULTURE (CONTINUED) RUS FIDELITY AND INSURANCE REQUIREMENTS FOR ELECTRIC AND TELECOMMUNICATIONS BORROWERS Insurance for Contractors, Engineers, and Architects, Telecommunications Borrowers...

75 FR 37881 - Surety Companies Acceptable on Federal Bonds-Change in State of Incorporation United States...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-30

..., Financial Management Service, Financial Accounting and Services Division, Surety Bond Branch, 3700 East-West..., Financial Accounting and Services Division. [FR Doc. 2010-15614 Filed 6-29-10; 8:45 am] BILLING CODE 4810-35... State of Incorporation United States Fidelity and Guaranty Company AGENCY: Financial Management Service...

17 CFR 270.17g-1 - Bonding of officers and employees of registered management investment companies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... be issued by a reputable fidelity insurance company, authorized to do business in the place where the... this section shall provide that it shall not be cancelled, terminated or modified except after written... insured bond described in paragraph (b)(3) of this section shall provide, that (1) it shall not be...

7 CFR 1779.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... marriage, or within the same household, such as a spouse, parent, child, brother, sister, aunt, uncle..., liability, property damage, flood or mudslide, worker's compensation, fidelity bond, malpractice, or any...

7 CFR 1779.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... marriage, or within the same household, such as a spouse, parent, child, brother, sister, aunt, uncle..., liability, property damage, flood or mudslide, worker's compensation, fidelity bond, malpractice, or any...

7 CFR 1779.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... marriage, or within the same household, such as a spouse, parent, child, brother, sister, aunt, uncle..., liability, property damage, flood or mudslide, worker's compensation, fidelity bond, malpractice, or any...

27 CFR 19.231 - Accounting for bond coverage.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... If the balance of the bond account reaches zero, the proprietor may no longer defer tax payments for... coverage. 19.231 Section 19.231 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits Taxes Rules for...

27 CFR 19.167 - Increase of bond coverage.

Code of Federal Regulations, 2014 CFR

2014-04-01

... separate strengthening bond in accordance with paragraph (b) of this section. (b) Strengthening bonds. A strengthening bond is a second bond with the same surety as on the original bond which covers the increased liability. A strengthening bond must show both its execution date and its effective date. TTB will not...

27 CFR 19.167 - Increase of bond coverage.

Code of Federal Regulations, 2013 CFR

2013-04-01

... separate strengthening bond in accordance with paragraph (b) of this section. (b) Strengthening bonds. A strengthening bond is a second bond with the same surety as on the original bond which covers the increased liability. A strengthening bond must show both its execution date and its effective date. TTB will not...

27 CFR 19.167 - Increase of bond coverage.

Code of Federal Regulations, 2012 CFR

2012-04-01

... separate strengthening bond in accordance with paragraph (b) of this section. (b) Strengthening bonds. A strengthening bond is a second bond with the same surety as on the original bond which covers the increased liability. A strengthening bond must show both its execution date and its effective date. TTB will not...

27 CFR 19.167 - Increase of bond coverage.

Code of Federal Regulations, 2011 CFR

2011-04-01

... separate strengthening bond in accordance with paragraph (b) of this section. (b) Strengthening bonds. A strengthening bond is a second bond with the same surety as on the original bond which covers the increased liability. A strengthening bond must show both its execution date and its effective date. TTB will not...

27 CFR 40.135 - Strengthening bond.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2013-04-01 2013-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the bond...

27 CFR 40.135 - Strengthening bond.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the bond...

27 CFR 40.135 - Strengthening bond.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the bond...

27 CFR 40.135 - Strengthening bond.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2014-04-01 2014-04-01 false Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the bond...

27 CFR 40.135 - Strengthening bond.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Strengthening bond. 40.135... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.135 Strengthening bond. Where the amount of... immediately file a strengthening bond in an appropriate amount with the same surety as that on the bond...

Programming Recognition Arrays through Double Chalcogen-Bonding Interactions.

PubMed

Biot, Nicolas; Bonifazi, Davide

2018-04-11

In this work, we have programmed and synthesized a recognition motif constructed around a chalcogenazolo-pyridine scaffold (CGP) that, through the formation of frontal double chalcogen-bonding interactions, associates into dimeric EX-type complexes. The reliability of the double chalcogen-bonding interaction has been shown at the solid-state by X-ray analysis, depicting the strongest recognition persistence for a Te-congener. The high recognition fidelity, chemical and thermal stability and easy derivatization at the 2-position makes CGP a convenient motif for constructing supramolecular architectures through programmed chalcogen-bonding interactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

46 CFR 308.531 - Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 8 2014-10-01 2014-10-01 false Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Open Policy War Risk Cargo...

Recognition of Watson-Crick base pairs: constraints and limits due to geometric selection and tautomerism

PubMed Central

Yusupov, Marat; Yusupova, Gulnara

2014-01-01

The natural bases of nucleic acids have a strong preference for one tautomer form, guaranteeing fidelity in their hydrogen bonding potential. However, base pairs observed in recent crystal structures of polymerases and ribosomes are best explained by an alternative base tautomer, leading to the formation of base pairs with Watson-Crick-like geometries. These observations set limits to geometric selection in molecular recognition of complementary Watson-Crick pairs for fidelity in replication and translation processes. PMID:24765524

GIS management system of power plant staff based on wireless fidelity indoor location technology

NASA Astrophysics Data System (ADS)

Zhang, Ting

2017-05-01

The labor conditions and environment of electric power production are quite complicated. It is very difficult to realize the real-time supervision of the employees' working conditions and safety. Using the existing base stations in the power plant, the wireless fidelity network is established to realize the wireless coverage of the work site. We can use mobile phone to communicate and achieve positioning. The main content of this project is based on the special environment of the power plant, designed a suitable for ordinary Android mobile phone indoor wireless fidelity positioning system, real-time positioning and record the scene of each employee's movement trajectory, has achieved real-time staff check Gang, Staff in place, and for the safety of employees to provide a guarantee.

27 CFR 40.133 - Amount of individual bond.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Amount of individual bond. 40.133 Section 40.133 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU..., AND PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.133 Amount of individual bond...

Enhancing Protein Disulfide Bond Cleavage by UV Excitation and Electron Capture Dissociation for Top-Down Mass Spectrometry.

PubMed

Wongkongkathep, Piriya; Li, Huilin; Zhang, Xing; Loo, Rachel R Ogorzalek; Julian, Ryan R; Loo, Joseph A

2015-11-15

The application of ion pre-activation with 266 nm ultraviolet (UV) laser irradiation combined with electron capture dissociation (ECD) is demonstrated to enhance top-down mass spectrometry sequence coverage of disulfide bond containing proteins. UV-based activation can homolytically cleave a disulfide bond to yield two separated thiol radicals. Activated ECD experiments of insulin and ribonuclease A containing three and four disulfide bonds, respectively, were performed. UV-activation in combination with ECD allowed the three disulfide bonds of insulin to be cleaved and the overall sequence coverage to be increased. For the larger sized ribonuclease A with four disulfide bonds, irradiation from an infrared laser (10.6 µm) to disrupt non-covalent interactions was combined with UV-activation to facilitate the cleavage of up to three disulfide bonds. Preferences for disulfide bond cleavage are dependent on protein structure and sequence. Disulfide bonds can reform if the generated radicals remain in close proximity. By varying the time delay between the UV-activation and the ECD events, it was determined that disulfide bonds reform within 10-100 msec after their UV-homolytic cleavage.

7 CFR 906.31 - Duties.

Code of Federal Regulations, 2014 CFR

2014-01-01

... things, the duty of the committee: (a) At the beginning of each term of office, to meet and organize, to... fidelity bonds for all persons handling funds; (f) To investigate from time to time and to assemble data on...

Why CO bonds side-on at low coverage and both side-on and upright at high coverage on the Cr(110) surface

NASA Technical Reports Server (NTRS)

Mehandru, S. P.; Anderson, A. B.

1985-01-01

An atom superposition and electron delocalization molecular orbital study of CO adsorption on the Cr(110) surface shows a high coordinate lying down orientation is favored. This is a result of the large number of empty d-band energy levels in chromium, which allows the antibonding counterparts to sigma and pi donation bonds to the surface to be empty. When lying down, backbonding to CO pi sup * orbitals is enhanced. Repulsive interactions cause additional CO to stand upright at 1/4 monolyer coverage. The results confirm the recent experimental study of Shinn and Madey.

7 CFR 1484.55 - What expenditures may not be reimbursed under the Cooperator program?

Code of Federal Regulations, 2010 CFR

2010-01-01

...., displays lasting beyond one marketing plan year; (6) Office parking fees; (7) Coupon redemption or price... social organizations; (17) Indemnity and fidelity bonds; (18) Fees for participating in U.S. Government... conclusion of the marketing plan year. ...

7 CFR 906.31 - Duties.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... fidelity bonds for all persons handling funds; (f) To investigate from time to time and to assemble data on the growing, harvesting, shipping, and marketing conditions with respect to fruit; (g) To prepare a...

Adsorption of acrolein, propanal, and allyl alcohol on Pd(111): a combined infrared reflection–absorption spectroscopy and temperature programmed desorption study

PubMed Central

Dostert, Karl-Heinz; O'Brien, Casey P.; Mirabella, Francesca; Ivars-Barceló, Francisco

2016-01-01

Atomistic-level understanding of the interaction of α,β-unsaturated aldehydes and their derivatives with late transition metals is of fundamental importance for the rational design of new catalytic materials with the desired selectivity towards C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C vs. CO bond partial hydrogenation. In this study, we investigate the interaction of acrolein, and its partial hydrogenation products propanal and allyl alcohol, with Pd(111) as a prototypical system. A combination of infrared reflection–absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) experiments was applied under well-defined ultrahigh vacuum (UHV) conditions to obtain detailed information on the adsorption geometries of acrolein, propanal, and allyl alcohol as a function of coverage. We compare the IR spectra obtained for multilayer coverages, reflecting the molecular structure of unperturbed molecules, with the spectra acquired for sub-monolayer coverages, at which the chemical bonds of the molecules are strongly distorted. Coverage-dependent IR spectra of acrolein on Pd(111) point to the strong changes in the adsorption geometry with increasing acrolein coverage. Acrolein adsorbs with the CC and CO bonds lying parallel to the surface in the low coverage regime and changes its geometry to a more upright orientation with increasing coverage. TPD studies indicate decomposition of the species adsorbed in the sub-monolayer regime upon heating. Similar strong coverage dependence of the IR spectra were found for propanal and allyl alcohol. For all investigated molecules a detailed assignment of vibrational bands is reported. PMID:27149902

25 CFR 211.24 - Bonds.

Code of Federal Regulations, 2010 CFR

2010-04-01

... AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT...,000 bond for all geothermal, mining, or oil and gas leases, permits, or assignments in any one State...,000 bond for full nationwide coverage to cover all geothermal or oil and gas leases, permits, or...

40 CFR 280.98 - Surety bond.

Code of Federal Regulations, 2010 CFR

2010-07-01

...: Performance Bond Date bond executed: Period of coverage: Principal: [legal name and business address of owner... “corporation”] State of incorporation (if applicable): Surety(ies): [name(s) and business address(es)] Scope of...) shall not be discharged by any payment or succession of payments hereunder, unless and until such...

27 CFR 40.131 - Corporate surety.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Corporate surety. 40.131... PROCESSED TOBACCO Bonds and Extensions of Coverage of Bonds § 40.131 Corporate surety. (a) Surety bonds required under the provisions of this part may be given only with corporate sureties holding certificates...

25 CFR 225.30 - Bonds.

Code of Federal Regulations, 2010 CFR

2010-04-01

... AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS... Circular No. 570). (b) An operator may file a $75,000 bond for all geothermal, mining, or oil and gas... operator may file a $150,000 bond for full nationwide coverage to cover all geothermal or oil and gas...

25 CFR 225.30 - Bonds.

Code of Federal Regulations, 2011 CFR

2011-04-01

... AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS... Circular No. 570). (b) An operator may file a $75,000 bond for all geothermal, mining, or oil and gas... operator may file a $150,000 bond for full nationwide coverage to cover all geothermal or oil and gas...

27 CFR 25.98 - Surety or security.

Code of Federal Regulations, 2012 CFR

2012-04-01

... coverage. Bonds required by this part will be given with corporate surety or collateral security. (b... limitations set forth for corporate security by the Secretary which are set forth in the current revision of... penal sum of the bond. (e) Deposit of collateral securities in lieu of corporate surety. Bonds or notes...

27 CFR 25.98 - Surety or security.

Code of Federal Regulations, 2013 CFR

2013-04-01

... coverage. Bonds required by this part will be given with corporate surety or collateral security. (b... limitations set forth for corporate security by the Secretary which are set forth in the current revision of... penal sum of the bond. (e) Deposit of collateral securities in lieu of corporate surety. Bonds or notes...

27 CFR 25.98 - Surety or security.

Code of Federal Regulations, 2010 CFR

2010-04-01

... coverage. Bonds required by this part will be given with corporate surety or collateral security. (b... limitations set forth for corporate security by the Secretary which are set forth in the current revision of... penal sum of the bond. (e) Deposit of collateral securities in lieu of corporate surety. Bonds or notes...

27 CFR 25.98 - Surety or security.

Code of Federal Regulations, 2011 CFR

2011-04-01

... coverage. Bonds required by this part will be given with corporate surety or collateral security. (b... limitations set forth for corporate security by the Secretary which are set forth in the current revision of... penal sum of the bond. (e) Deposit of collateral securities in lieu of corporate surety. Bonds or notes...

27 CFR 25.98 - Surety or security.

Code of Federal Regulations, 2014 CFR

2014-04-01

... coverage. Bonds required by this part will be given with corporate surety or collateral security. (b... limitations set forth for corporate security by the Secretary which are set forth in the current revision of... penal sum of the bond. (e) Deposit of collateral securities in lieu of corporate surety. Bonds or notes...

Impact of coverage on the reliability of a fault tolerant computer

NASA Technical Reports Server (NTRS)

Bavuso, S. J.

1975-01-01

A mathematical reliability model is established for a reconfigurable fault tolerant avionic computer system utilizing state-of-the-art computers. System reliability is studied in light of the coverage probabilities associated with the first and second independent hardware failures. Coverage models are presented as a function of detection, isolation, and recovery probabilities. Upper and lower bonds are established for the coverage probabilities and the method for computing values for the coverage probabilities is investigated. Further, an architectural variation is proposed which is shown to enhance coverage.

A novel bonding method for large scale poly(methyl methacrylate) micro- and nanofluidic chip fabrication

NASA Astrophysics Data System (ADS)

Qu, Xingtian; Li, Jinlai; Yin, Zhifu

2018-04-01

Micro- and nanofluidic chips are becoming increasing significance for biological and medical applications. Future advances in micro- and nanofluidics and its utilization in commercial applications depend on the development and fabrication of low cost and high fidelity large scale plastic micro- and nanofluidic chips. However, the majority of the present fabrication methods suffer from a low bonding rate of the chip during thermal bonding process due to air trapping between the substrate and the cover plate. In the present work, a novel bonding technique based on Ar plasma and water treatment was proposed to fully bond the large scale micro- and nanofluidic chips. The influence of Ar plasma parameters on the water contact angle and the effect of bonding conditions on the bonding rate and the bonding strength of the chip were studied. The fluorescence tests demonstrate that the 5 × 5 cm2 poly(methyl methacrylate) chip with 180 nm wide and 180 nm deep nanochannels can be fabricated without any block and leakage by our newly developed method.

Structure and dynamics of water near the interface with oligo(ethylene oxide) self-assembled monolayers

NASA Astrophysics Data System (ADS)

Ismail, Ahmed E.; Grest, Gary S.; Stevens, Mark J.

2007-03-01

Oligo(ethylene oxide) self-assembled monolayers (OEO SAM's) deposited on Au are the prototypical materials used to study protein resistance. Recently, protein resistance has been shown to vary as a function of surface coverage and to be maximal at about two-thirds coverage, not complete coverage. We use molecular dynamics simulations to study the nature of the interface between water and the OEO SAM for a range of SAM coverages. As SAM coverage decreases, the amount of water within the OEO monolayer increases monotonically; however, the penetration depth of the water shows a maximum near the experimentally-found maximal coverage. As the water content increases, the SAM-water mixture becomes harder to distinguish from bulk water. Since the oxygen atoms of OEO are hydrogen bond acceptors, a hydrogen bond network forms within the SAM-water mixture. The water molecules diffuse freely within the monolayer and exchange with the bulk water. Because the monolayer becomes increasingly like bulk water as the coverage decreases, proteins stay in their bulk soluble conformation and do not adsorb. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract No. DE-AC04-94AL85000.

The reactions of thiophene on Mo(110) and Mo(110)-p(2×2)-S

NASA Astrophysics Data System (ADS)

Roberts, Jeffrey T.; Friend, C. M.

1987-07-01

The reactions of thiophene and 2,5-dideuterothiophene on Mo(110) and Mo(110)-p(2×2)-S have been investigated under ultrahigh vacuum conditions using temperature programmed reaction spectroscopy and Auger electron spectroscopy. Thiophene chemisorbed on Mo(110) decomposes during temperature programmed reaction to yield only gaseous dihydrogen, surface carbon, and surface sulfur. At low thiophene exposures, dihydrogen evolves from Mo(110) in a symmetric peak at 440 K. At saturation exposures, three dihydrogen peaks are detected at 360 K, at 420 K and at 565 K. Multilayers of thiophene desorb at 180 K. Temperature programmed reaction of 2,5-dideuterothiophene demonstrates that at high thiophene coverages, one of the α-C-H bonds (those nearest sulfur) breaks first. No bond breaking selectivity is observed at low thiophene exposures. The Mo(110)-p(2×2)-S surface is less active for thiophene decomposition. Thiophene adsorbed on Mo(110)-p(2×2)-S to low coverages decomposes to surface carbon surface sulfur, and hydrogen at 430 K. At reaction saturation, dihydrogen production is observed at 375 and 570 K. In addition, at moderate and high exposures, chemisorbed thiophene desorbs from Mo(110)-p(2×2)-S. At saturation the desorption temperature of the reversibly chemisorbed state is 215 K. Experiments with 2,5-dideuterothiophene demonstrate no surface selectivity for α-C-H bond breaking reactions on Mo(110)-p(2×2)-S. The decomposition mechanism and energetics of thiophene decomposition are proposed to be dependent on the coverage of thiophene. At low thiophene exposures, the ring is proposed to bond parallel to the surface. All C-H bonds in the parallel geometry are sterically available for activation by the surface, accounting for the lack of selectivity in C-H bond breaking. High thiophene coverages are suggested to result in perpendicularly bound thiophene which undergoes selective α-dehydrogenation to an α)-thiophenyl intermediate. The presence of sulfur leads to a high energy pathway for cleavage of C-H bonds in a thiophene derived intermediate. Carbon-hydrogen bonds survive on the surface up to temperatures of 650 K. Comparison of this study with work on Mo(100) demonstrates that the reaction of thiophene on molybdenum is relatively insensitive to the surface geometric structure.

Structure and energetics of hydrogen-bonded networks of methanol on close packed transition metal surfaces

NASA Astrophysics Data System (ADS)

Murphy, Colin J.; Carrasco, Javier; Lawton, Timothy J.; Liriano, Melissa L.; Baber, Ashleigh E.; Lewis, Emily A.; Michaelides, Angelos; Sykes, E. Charles H.

2014-07-01

Methanol is a versatile chemical feedstock, fuel source, and energy storage material. Many reactions involving methanol are catalyzed by transition metal surfaces, on which hydrogen-bonded methanol overlayers form. As with water, the structure of these overlayers is expected to depend on a delicate balance of hydrogen bonding and adsorbate-substrate bonding. In contrast to water, however, relatively little is known about the structures methanol overlayers form and how these vary from one substrate to another. To address this issue, herein we analyze the hydrogen bonded networks that methanol forms as a function of coverage on three catalytically important surfaces, Au(111), Cu(111), and Pt(111), using a combination of scanning tunneling microscopy and density functional theory. We investigate the effect of intermolecular interactions, surface coverage, and adsorption energies on molecular assembly and compare the results to more widely studied water networks on the same surfaces. Two main factors are shown to direct the structure of methanol on the surfaces studied: the surface coverage and the competition between the methanol-methanol and methanol-surface interactions. Additionally, we report a new chiral form of buckled hexamer formed by surface bound methanol that maximizes the interactions between methanol monomers by sacrificing interactions with the surface. These results serve as a direct comparison of interaction strength, assembly, and chirality of methanol networks on Au(111), Cu(111), and Pt(111) which are catalytically relevant for methanol oxidation, steam reforming, and direct methanol fuel cells.

Quantitative analysis of desorption and decomposition kinetics of formic acid on Cu(111): The importance of hydrogen bonding between adsorbed species

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

Shiozawa, Yuichiro; Koitaya, Takanori; Mukai, Kozo

2015-12-21

Quantitative analysis of desorption and decomposition kinetics of formic acid (HCOOH) on Cu(111) was performed by temperature programmed desorption (TPD), X-ray photoelectron spectroscopy, and time-resolved infrared reflection absorption spectroscopy. The activation energy for desorption is estimated to be 53–75 kJ/mol by the threshold TPD method as a function of coverage. Vibrational spectra of the first layer HCOOH at 155.3 K show that adsorbed molecules form a polymeric structure via the hydrogen bonding network. Adsorbed HCOOH molecules are dissociated gradually into monodentate formate species. The activation energy for the dissociation into monodentate formate species is estimated to be 65.0 kJ/mol atmore » a submonolayer coverage (0.26 molecules/surface Cu atom). The hydrogen bonding between adsorbed HCOOH species plays an important role in the stabilization of HCOOH on Cu(111). The monodentate formate species are stabilized at higher coverages, because of the lack of vacant sites for the bidentate formation.« less

20 CFR 418.2010 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... All-inclusive Care for the Elderly plan offering qualified prescription drug coverage, or a cost plan...) Tax-exempt interest income; (ii) Income from United States savings bonds used to pay higher education... Program of All-Inclusive Care for the Elderly Plan offering qualified prescription drug coverage, or a...

Adhesives in Building--Lamination of Structural Timber Beams, Bonding of Cementitious Materials, Bonding of Gypsum Drywall Construction. Proceedings of a Conference of the Building Research Institute, Division of Engineering and Industrial Research (Spring 1960).

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC.

The role of adhesives in building design is discussed. Three major areas are as follows--(1) lamination of structural timber beams, (2) bonding of cementitious materials, and (3) bonding of gypsum drywall construction. Topical coverage includes--(1) structural lamination today, (2) adhesives in use today, (3) new adhesives needed, (4) production…

12 CFR 747.311 - Relevant considerations.

Code of Federal Regulations, 2010 CFR

2010-01-01

....311 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS..., whether the bond is likely to be revoked, or whether coverage under the bond will be affected adversely as... specific case, appear relevant to the decision to continue in effect, rescind, terminate, or modify a...

Molecular effective coverage surface area of optical clearing agents for predicting optical clearing potential

NASA Astrophysics Data System (ADS)

Feng, Wei; Ma, Ning; Zhu, Dan

2015-03-01

The improvement of methods for optical clearing agent prediction exerts an important impact on tissue optical clearing technique. The molecular dynamic simulation is one of the most convincing and simplest approaches to predict the optical clearing potential of agents by analyzing the hydrogen bonds, hydrogen bridges and hydrogen bridges type forming between agents and collagen. However, the above analysis methods still suffer from some problem such as analysis of cyclic molecule by reason of molecular conformation. In this study, a molecular effective coverage surface area based on the molecular dynamic simulation was proposed to predict the potential of optical clearing agents. Several typical cyclic molecules, fructose, glucose and chain molecules, sorbitol, xylitol were analyzed by calculating their molecular effective coverage surface area, hydrogen bonds, hydrogen bridges and hydrogen bridges type, respectively. In order to verify this analysis methods, in vitro skin samples optical clearing efficacy were measured after 25 min immersing in the solutions, fructose, glucose, sorbitol and xylitol at concentration of 3.5 M using 1951 USAF resolution test target. The experimental results show accordance with prediction of molecular effective coverage surface area. Further to compare molecular effective coverage surface area with other parameters, it can show that molecular effective coverage surface area has a better performance in predicting OCP of agents.

On-Line Electrochemical Reduction of Disulfide Bonds: Improved FTICR-CID and -ETD Coverage of Oxytocin and Hepcidin

NASA Astrophysics Data System (ADS)

Nicolardi, Simone; Giera, Martin; Kooijman, Pieter; Kraj, Agnieszka; Chervet, Jean-Pierre; Deelder, André M.; van der Burgt, Yuri E. M.

2013-12-01

Particularly in the field of middle- and top-down peptide and protein analysis, disulfide bridges can severely hinder fragmentation and thus impede sequence analysis (coverage). Here we present an on-line/electrochemistry/ESI-FTICR-MS approach, which was applied to the analysis of the primary structure of oxytocin, containing one disulfide bridge, and of hepcidin, containing four disulfide bridges. The presented workflow provided up to 80 % (on-line) conversion of disulfide bonds in both peptides. With minimal sample preparation, such reduction resulted in a higher number of peptide backbone cleavages upon CID or ETD fragmentation, and thus yielded improved sequence coverage. The cycle times, including electrode recovery, were rapid and, therefore, might very well be coupled with liquid chromatography for protein or peptide separation, which has great potential for high-throughput analysis.

HyspIRI Low Latency Concept and Benchmarks

NASA Technical Reports Server (NTRS)

Mandl, Dan

2010-01-01

Topics include HyspIRI low latency data ops concept, HyspIRI data flow, ongoing efforts, experiment with Web Coverage Processing Service (WCPS) approach to injecting new algorithms into SensorWeb, low fidelity HyspIRI IPM testbed, compute cloud testbed, open cloud testbed environment, Global Lambda Integrated Facility (GLIF) and OCC collaboration with Starlight, delay tolerant network (DTN) protocol benchmarking, and EO-1 configuration for preliminary DTN prototype.

76 FR 11542 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Order Approving...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

... To Adopt FINRA Rule 4360 (Fidelity Bonds) in the Consolidated FINRA Rulebook February 24, 2011. I... Exchange Act of 1934 (``Exchange Act'') \\1\\ and Rule 19b-4 thereunder,\\2\\ a proposed rule change to adopt.... 31, 2010 (``Kramer''). II. Description of Proposed Rule Change A. Summary FINRA is proposing to adopt...

26 CFR 46.4371-2 - Imposition of tax on policies issued by foreign insurers; scope of tax.

Code of Federal Regulations, 2012 CFR

2012-04-01

... indemnity, fidelity, or surety bond is made, continued, or renewed, if issued: (1) By a nonresident alien... section 4372(c). (b) Life insurance, sickness, and accident policies, and annuity contracts. Unless the... contract is made, continued, or renewed, if issued: (1) By a nonresident alien individual, a foreign...

26 CFR 46.4371-2 - Imposition of tax on policies issued by foreign insurers; scope of tax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... indemnity, fidelity, or surety bond is made, continued, or renewed, if issued: (1) By a nonresident alien... section 4372(c). (b) Life insurance, sickness, and accident policies, and annuity contracts. Unless the... contract is made, continued, or renewed, if issued: (1) By a nonresident alien individual, a foreign...

26 CFR 46.4371-2 - Imposition of tax on policies issued by foreign insurers; scope of tax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... indemnity, fidelity, or surety bond is made, continued, or renewed, if issued: (1) By a nonresident alien... section 4372(c). (b) Life insurance, sickness, and accident policies, and annuity contracts. Unless the... contract is made, continued, or renewed, if issued: (1) By a nonresident alien individual, a foreign...

Picosecond Pulsed Laser Ablation for the Surface Preparation of Epoxy Composites

NASA Technical Reports Server (NTRS)

Palmieri, Frank; Ledesma, Rodolfo; Fulton, Tayler; Arthur, Alexandria; Eldridge, Keishara; Thibeault, Sheila; Lin, Yi; Wohl, Chris; Connell, John

2017-01-01

As part of a technical challenge under the Advanced Composites Program, methods for improving pre-bond process control for aerospace composite surface treatments and inspections, in conjunction with Federal Aviation Administration guidelines, are under investigation. The overall goal is to demonstrate high fidelity, rapid and reproducible surface treatment and surface characterization methods to reduce uncertainty associated with the bonding process. The desired outcomes are reliable bonded airframe structure, and reduced timeline to certification. In this work, laser ablation was conducted using a q-switched Nd:YVO4 laser capable of nominal pulse durations of 8 picoseconds (ps). Aerospace structural carbon fiber reinforced composites with an epoxy resin matrix were laser treated, characterized, processed into bonded assemblies and mechanically tested. The characterization of ablated surfaces were conducted using scanning electron microscopy (SEM), water contact angle (WCA) goniometry, micro laser induced breakdown spectroscopy (uLIBS), and electron spin resonance (ESR). The bond performance was assessed using a double cantilever beam (DCB) test with an epoxy adhesive. The surface characteristics and bond performance obtained from picosecond ablated carbon fiber reinforced plastics (CFRPs) are presented herein.

Association of bond, market, operational, and financial factors with multi-hospital system bond issues.

PubMed

Carpenter, C E; McCue, M J; Hossack, J B

2001-01-01

Despite the growth of multi-hospital systems in the 1990s, their performance in the tax-exempt bond market has not been adequately evaluated. The purpose of this study is to compare bonds issued by multi-hospital systems to those issued by individual hospitals in terms of bond, market, operational, and financial characteristics. The study sample includes 2,078 newly issued, tax-exempt, revenue bonds between 1991 and 1997. The findings indicate that multi-hospital systems issued larger amounts of debt at a lower cost, were more likely to be insured, had higher debt service coverage and higher operating margins.

Association of HMO penetration and other credit quality factors with tax-exempt bond yields.

PubMed

McCue, M J

1997-01-01

This paper evaluates the relationship of HMO penetration, as well as other credit quality measures of market, institutional, operational, and financial traits, to tax-exempt bond yields. The study analyzed more than 1,500 bond issues from 1990 through 1993 and corrected for simultaneous relationships between bond size and yield and selection bias. The study found lower bond yields for hospitals located in markets with no HMO penetration. Lower yields for bond issues also were found for facilities generating higher numbers of days cash on hand and greater debt service coverage. Finally, results show that hospitals with higher occupancy rates achieve a lower yield.

L-Tryptophan on Cu(111): engineering a molecular labyrinth driven by indole groups

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

Yitamben, E. N.; Clayborne, A.; Darling, Seth B.

2015-05-21

The present article investigates the adsorption and molecular orientation of L-Tryptophan, which is both an essential amino acid important for protein synthesis and of particular interest for the development of chiral molecular electronics and biocompatible processes and devices, on Cu(111) using scanning tunneling microscopy and spectroscopy at 55 K and at room temperature. The arrangement of chemisorbed L-Tryptophan on the copper surface varies with both temperature and surface coverage. At low coverage, small clusters form on the surface irrespective of temperature, while at high coverage an ordered chain structure emerges at room temperature, and a tightly packed structure forms amore » molecular labyrinth at low temperature. The dominating superstructure of the adsorbates arises from intermolecular hydrogen bonding, and pi-bonding interactions between the indole groups of neighboring molecules and the Cu surface.« less

Adsorption and reaction of propene on Ni(100)

NASA Astrophysics Data System (ADS)

Kleyna, R.; Borgmann, D.; Wedler, G.

1998-05-01

Photoelectron spectroscopy (UPS, XPS) and thermal desorption techniques were used to study the chemisorption and decomposition reactions of propene on Ni(100). Propene is molecularly adsorbed at temperatures below 150 K. At saturation coverage the TD spectrum shows two propene desorption peaks at 155 and 225 K and three hydrogen desorption peaks at 300, 330 and 380 K with a shoulder at 420 K. No other desorbing species could be detected. The amount of desorption of propene was determined by XPS to be 20% of the saturation coverage. The electronic structure of adsorbed propene and the chemical nature of its decomposition products were deduced from UP and XP spectra taken at saturation coverage. Adsorption at low temperatures results in a π-bonded species which is stable up to 150 K. At temperatures above 150 K the UP spectra point to a σ-bonded species which decomposes further at temperatures above 260 K.

Standard and inverse bond percolation of straight rigid rods on square lattices

NASA Astrophysics Data System (ADS)

Ramirez, L. S.; Centres, P. M.; Ramirez-Pastor, A. J.

2018-04-01

Numerical simulations and finite-size scaling analysis have been carried out to study standard and inverse bond percolation of straight rigid rods on square lattices. In the case of standard percolation, the lattice is initially empty. Then, linear bond k -mers (sets of k linear nearest-neighbor bonds) are randomly and sequentially deposited on the lattice. Jamming coverage pj ,k and percolation threshold pc ,k are determined for a wide range of k (1 ≤k ≤120 ). pj ,k and pc ,k exhibit a decreasing behavior with increasing k , pj ,k →∞=0.7476 (1 ) and pc ,k →∞=0.0033 (9 ) being the limit values for large k -mer sizes. pj ,k is always greater than pc ,k, and consequently, the percolation phase transition occurs for all values of k . In the case of inverse percolation, the process starts with an initial configuration where all lattice bonds are occupied and, given that periodic boundary conditions are used, the opposite sides of the lattice are connected by nearest-neighbor occupied bonds. Then, the system is diluted by randomly removing linear bond k -mers from the lattice. The central idea here is based on finding the maximum concentration of occupied bonds (minimum concentration of empty bonds) for which connectivity disappears. This particular value of concentration is called the inverse percolation threshold pc,k i, and determines a geometrical phase transition in the system. On the other hand, the inverse jamming coverage pj,k i is the coverage of the limit state, in which no more objects can be removed from the lattice due to the absence of linear clusters of nearest-neighbor bonds of appropriate size. It is easy to understand that pj,k i=1 -pj ,k . The obtained results for pc,k i show that the inverse percolation threshold is a decreasing function of k in the range 1 ≤k ≤18 . For k >18 , all jammed configurations are percolating states, and consequently, there is no nonpercolating phase. In other words, the lattice remains connected even when the highest allowed concentration of removed bonds pj,k i is reached. In terms of network attacks, this striking behavior indicates that random attacks on single nodes (k =1 ) are much more effective than correlated attacks on groups of close nodes (large k 's). Finally, the accurate determination of critical exponents reveals that standard and inverse bond percolation models on square lattices belong to the same universality class as the random percolation, regardless of the size k considered.

46 CFR 308.531 - Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311.

Code of Federal Regulations, 2011 CFR

2011-10-01

... amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo..., Form MA-311, may be obtained from the American War Risk Agency or MARAD. ...

46 CFR 308.531 - Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311.

Code of Federal Regulations, 2010 CFR

2010-10-01

... amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo..., Form MA-311, may be obtained from the American War Risk Agency or MARAD. ...

46 CFR 308.531 - Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311.

Code of Federal Regulations, 2013 CFR

2013-10-01

... amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo..., Form MA-311, may be obtained from the American War Risk Agency or MARAD. ...

46 CFR 308.531 - Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311.

Code of Federal Regulations, 2012 CFR

2012-10-01

... amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo..., Form MA-311, may be obtained from the American War Risk Agency or MARAD. ...

Simulating the fidelity and the three Mg mechanism of pol η and clarifying the validity of transition state theory in enzyme catalysis.

PubMed

Yoon, Hanwool; Warshel, Arieh

2017-08-01

Pol η belongs to the important Y family of DNA polymerases that can catalyze translesion synthesis across sites of damaged DNA. This activity involves the reduced fidelity of Pol η for 8-oxo-7,8-dhyedro-2'-deoxoguanosin(8-oxoG). The fundamental interest in Pol η has grown recently with the demonstration of the importance of a 3rd Mg2+ ion. The current work explores both the fidelity of Pol η and the role of the 3rd metal ion, by using empirical valence bond (EVB) simulations. The simulations reproduce the observed trend in fidelity and shed a new light on the role of the 3rd metal ion. It is found that this ion does not lead to a major catalytic effect, but most probably plays an important role in reducing the product release barrier. Furthermore, it is concluded, in contrast to some implications, that the effect of this metal does not violate transition state theory, and the evaluation of the catalytic effect must conserve the molecular composition upon moving from the reactant to the transition state. Proteins 2017; 85:1446-1453. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Structural and electronic properties of AlN(0001) surface under partial N coverage as determined by ab initio approach

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

Strak, Pawel; Sakowski, Konrad; Kempisty, Pawel

2015-09-07

Properties of bare and nitrogen-covered Al-terminated AlN(0001) surface were determined using density functional theory (DFT) calculations. At a low nitrogen coverage, the Fermi level is pinned by Al broken bond states located below conduction band minimum. Adsorption of nitrogen is dissociative with an energy gain of 6.05 eV/molecule at a H3 site creating an overlap with states of three neighboring Al surface atoms. During this adsorption, electrons are transferred from Al broken bond to topmost N adatom states. Accompanying charge transfer depends on the Fermi level. In accordance with electron counting rule (ECR), the DFT results confirm the Fermi levelmore » is not pinned at the critical value of nitrogen coverage θ{sub N}(1) = 1/4 monolayer (ML), but it is shifted from an Al-broken bond state to Np{sub z} state. The equilibrium thermodynamic potential of nitrogen in vapor depends drastically on the Fermi level pinning being shifted by about 4 eV for an ECR state at 1/4 ML coverage. For coverage above 1/4 ML, adsorption is molecular with an energy gain of 1.5 eV at a skewed on-top position above an Al surface atom. Electronic states of the admolecule are occupied as in the free molecule, no electron transfer occurs and adsorption of a N{sub 2} molecule does not depend on the Fermi level. The equilibrium pressure of molecular nitrogen above an AlN(0001) surface depends critically on the Fermi level position, being very low and very high for low and high coverage, respectively. From this fact, one can conclude that at typical growth conditions, the Fermi level is not pinned, and the adsorption and incorporation of impurities depend on the position of Fermi level in the bulk.« less

48 CFR 728.305-70 - Overseas worker's compensation and war-hazard insurance-waivers and USAID insurance coverage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Overseas worker's compensation and war-hazard insurance-waivers and USAID insurance coverage. 728.305-70 Section 728.305-70... REQUIREMENTS BONDS AND INSURANCE Insurance 728.305-70 Overseas worker's compensation and war-hazard insurance...

Avoiding Thiol Compound Interference: A Nanoplatform Based on High-Fidelity Au-Se Bonds for Biological Applications.

PubMed

Hu, Bo; Kong, Fanpeng; Gao, Xiaonan; Jiang, Lulu; Li, Xiaofeng; Gao, Wen; Xu, Kehua; Tang, Bo

2018-05-04

Gold nanoparticles (Au NPs) assembled through Au-S covalent bonds have been widely used in biomolecule-sensing technologies. However, during the process, detection distortions caused by high levels of thiol compounds can still significantly influence the result and this problem has not really been solved. Based on the higher stability of Au-Se bonds compared to Au-S bonds, we prepared selenol-modified Au NPs as an Au-Se nanoplatform (NPF). Compared with the Au-S NPF, the Au-Se NPF exhibits excellent anti-interference properties in the presence of millimolar levels of glutathione (GSH). Such an Au-Se NPF that can effectively avoid detection distortions caused by high levels of thiols thus offers a new perspective in future nanomaterial design, as well as a novel platform with higher stability and selectivity for the in vivo application of chemical sensing and clinical therapies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancing protein stability with extended disulfide bonds

DOE PAGES

Liu, Tao; Wang, Yan; Luo, Xiaozhou; ...

2016-05-09

Disulfide bonds play an important role in protein folding and stability. However, the cross-linking of sites within proteins by cysteine disulfides has significant distance and dihedral angle constraints. In this paper, we report the genetic encoding of noncanonical amino acids containing long side-chain thiols that are readily incorporated into both bacterial and mammalian proteins in good yields and with excellent fidelity. These amino acids can pair with cysteines to afford extended disulfide bonds and allow cross-linking of more distant sites and distinct domains of proteins. To demonstrate this notion, we preformed growth-based selection experiments at nonpermissive temperatures using a librarymore » of random β-lactamase mutants containing these noncanonical amino acids. A mutant enzyme that is cross-linked by one such extended disulfide bond and is stabilized by ~9 °C was identified. Finally, this result indicates that an expanded set of building blocks beyond the canonical 20 amino acids can lead to proteins with improved properties by unique mechanisms, distinct from those possible through conventional mutagenesis schemes.« less

9 CFR 201.30 - Amount of market agency, dealer and packer bonds.

Code of Federal Regulations, 2010 CFR

2010-01-01

... coverage, divide the dollar value of livestock sold during the preceding business year, or the substantial part of that business year, in which the market agency did business, by the actual number of days on... required to comply with any State law. (b) Market agency buying on commission or dealer. The amount of bond...

Allopreening in birds is associated with parental cooperation over offspring care and stable pair bonds across years.

PubMed

Kenny, Elspeth; Birkhead, Tim R; Green, Jonathan P

2017-01-01

Individuals of many species form bonds with their breeding partners, yet the mechanisms maintaining these bonds are poorly understood. In birds, allopreening is a conspicuous feature of interactions between breeding partners and has been hypothesized to play a role in strengthening and maintaining pair bonds within and across breeding attempts. Many avian species, however, do not allopreen and the relationship between allopreening and pair bonding across species remains unexplored. In a comparative analysis of allopreening and pair bond behavior, we found that allopreening between breeding partners was more common among species where parents cooperate to rear offspring. The occurrence of allopreening was also associated with an increased likelihood that partners would remain together over successive breeding seasons. However, there was no strong evidence for an association between allopreening and sexual fidelity within seasons or time spent together outside the breeding season. Allopreening between partners was also no more common in colonial or cooperatively breeding species than in solitary species. Analyses of evolutionary transitions indicated that allopreening evolved from an ancestral state of either high parental cooperation or high partner retention, and we discuss possible explanations for this. Overall, our results are consistent with an important role for allopreening in the maintenance of avian pair bonds.

From concept to content: assessing the implementation fidelity of a chronic care model for frail, older people who live at home.

PubMed

Muntinga, Maaike E; Van Leeuwen, Karen M; Schellevis, François G; Nijpels, Giel; Jansen, Aaltje P D

2015-01-22

Implementation fidelity, the degree to which a care program is implemented as intended, can influence program impact. Since results of trials that aim to implement comprehensive care programs for frail, older people have been conflicting, assessing implementation fidelity alongside these trials is essential to differentiate between flaws inherent to the program and implementation issues. This study demonstrates how a theory-based assessment of fidelity can increase insight in the implementation process of a complex intervention in primary elderly care. The Geriatric Care Model was implemented among 35 primary care practices in the Netherlands. During home visits, practice nurses conducted a comprehensive geriatric assessment and wrote a tailored care plan. Multidisciplinary team consultations were organized with the aim to enhance the coordination between professionals caring for a single patient with complex needs. To assess fidelity, we identified 5 key intervention components and formulated corresponding research questions using Carroll's framework for fidelity. Adherence (coverage, frequency, duration, content) was assessed per intervention component during and at the end of the intervention period. Two moderating factors (participant responsiveness and facilitation strategies) were assessed at the end of the intervention. Adherence to the geriatric assessments and care plans was high, but decreased over time. Adherence to multidisciplinary consultations was initially poor, but increased over time. We found that individual differences in adherence between practice nurses and primary care physicians were moderate, while differences in participant responsiveness (satisfaction, involvement) were more distinct. Nurses deviated from protocol due to contextual factors and personal work routines. Adherence to the Geriatric Care Model was high for most of the essential intervention components. Study limitations include the limited number of assessed moderating factors. We argue that a longitudinal investigation of adherence per intervention component is essential for a complete understanding of the implementation process, but that such investigations may be complicated by practical and methodological challenges. The Netherlands National Trial Register (NTR). 2160 .

Comparison of the Computational Efficiency of the Original Versus Reformulated High-Fidelity Generalized Method of Cells

NASA Technical Reports Server (NTRS)

Arnold, Steven M; Bednarcyk, Brett; Aboydi, Jacob

2004-01-01

The High-Fidelity Generalized Method of Cells (HFGMC) micromechanics model has recently been reformulated by Bansal and Pindera (in the context of elastic phases with perfect bonding) to maximize its computational efficiency. This reformulated version of HFGMC has now been extended to include both inelastic phases and imperfect fiber-matrix bonding. The present paper presents an overview of the HFGMC theory in both its original and reformulated forms and a comparison of the results of the two implementations. The objective is to establish the correlation between the two HFGMC formulations and document the improved efficiency offered by the reformulation. The results compare the macro and micro scale predictions of the continuous reinforcement (doubly-periodic) and discontinuous reinforcement (triply-periodic) versions of both formulations into the inelastic regime, and, in the case of the discontinuous reinforcement version, with both perfect and weak interfacial bonding. The results demonstrate that identical predictions are obtained using either the original or reformulated implementations of HFGMC aside from small numerical differences in the inelastic regime due to the different implementation schemes used for the inelastic terms present in the two formulations. Finally, a direct comparison of execution times is presented for the original formulation and reformulation code implementations. It is shown that as the discretization employed in representing the composite repeating unit cell becomes increasingly refined (requiring a larger number of sub-volumes), the reformulated implementation becomes significantly (approximately an order of magnitude at best) more computationally efficient in both the continuous reinforcement (doubly-periodic) and discontinuous reinforcement (triply-periodic) cases.

Developing Inhibitors of Translesion DNA Synthesis as Therapeutic Agents against Lung Cancer

DTIC Science & Technology

2015-12-01

normal DNA synthesis. In contrast, pol eta shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties...are consistent with a pro- mutagenic role for pol eta when replicating this DNA lesion under cellular conditions. Studies with modified nucleotide...analogs indicate that pol eta relies heavily on hydrogen-bonding interactions during normal and translesion synthesis. However, some nucleobase

Polymerase recognition of 2-thio-iso-guanine·5-methyl-4-pyrimidinone (iGs·P)--A new DD/AA base pair.

PubMed

Lee, Dong-Kye; Switzer, Christopher

2016-02-15

Polymerase specificity is reported for a previously unknown base pair with a non-standard DD/AA hydrogen bonding pattern: 2-thio-iso-guanine·5-methyl-4-pyrimidinone. Our findings suggest that atomic substitution may provide a solution for low fidelity previously associated with enzymatic copying of iso-guanine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reliability Criteria for Thick Bonding Wire.

PubMed

Dagdelen, Turker; Abdel-Rahman, Eihab; Yavuz, Mustafa

2018-04-17

Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

Reliability Criteria for Thick Bonding Wire

PubMed Central

Yavuz, Mustafa

2018-01-01

Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire. PMID:29673194

Enhanced surface modification engineering (H, F, Cl, Br, and NO{sub 2}) of CdS nanowires with and without surface dangling bonds

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

Zeng, Yijie; Xing, Huaizhong, E-mail: xinghz@dhu.edu.cn; Lu, Aijiang

2015-08-07

Semiconductor nanowires (NWs) can be applied in gas sensing and cell detection, but the sensing mechanism is not clearly understood. In this study, surface modification effect on the electronic properties of CdS NWs for different diameters with several species (H, F, Cl, Br, and NO{sub 2}) is investigated by first principles calculations. The surface dangling bonds and halogen elements are chosen to represent the environment of the surface. Halogen passivation drastically changes the band gaps due to the strong electronegativity and the energy level of halogen atoms. Density of states analysis indicates that valence band maximum (VBM) of halogen-passivated NWsmore » is formed by the p states of halogen atoms, while VBM of H-passivated NWs is originated from Cd 4d and S 3p orbitals. To illustrate that surface modification can be applied in gas sensing, NO{sub 2}-absorbed NWs with different coverage are calculated. Low coverage of NO{sub 2} introduces a deep p-type dopant-like level, while high coverage introduces a shallow n-type dopant-like level into the band structure. The transformation is due to that at low coverage the adsorption is chemical while at high coverage is physical. These findings might promote the understanding of surface modification effect and the sensing mechanism of NWs as gas sensors.« less

Field Test of Expedient Pavement Repairs (Test Items 16-35).

DTIC Science & Technology

1980-11-01

82 61 Surface Profiles After Repairs, Item 34 ............ ... 83 62 Cracking of Bond, Item 34 ..... ................. . 84 ix JI x LIST OF...Limestone Base Course .... ............... . 79 18 Summary of Test Results ...... .................. . 88 x ABBREVIATIONS AND NOMENCLATURE Abbreviations AFESC...coverage$ Lateral quarter X - M5 coverages -020- - 0.251 +0.10- centerline -0.05- 0 0 I> + o.IO_ quarter point -0.10 -0.20- - 0.25+ TRAFFIC ZONES . Lonituina

Adsorption and Structure of Chiral Epoxides on Pd(111): Propylene Oxide and Glycidol

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

Mahapatra, Mausumi; Tysoe, Wilfred T.

Here, the adsorption of enantiopure versus racemic propylene oxide (PO) on Pd(111) is studied by temperature-programmed desorption (TPD) to explore possible differences in their saturation coverage. It is found that that the saturation coverage of enantiopure PO on Pd(111) is identical to that of racemic PO, in contrast to results on Pt(111) where significant coverage differences were found. The surface structures of enantiopure PO on Pd(111) were characterized by scanning tunneling microscopy (STM), which shows the formation of linear chains and hexagonal structures proposed to be due to freely rotating PO, in contrast to the relatively disordered PO overlayers foundmore » on Pt(111). STM experiments were carried out for enantiopure glycidol, which contains the same epoxy ring as PO, but where the methyl group of propylene oxide is replaced by a -CH 2OH group to provide a hydrogen-bonding sites. Glycidol STM images show the formation of completely different surface structures; at low coverages, glycidol forms pseudohexagonal structures which assemble from glycidol dimers, while at high coverages the surface shows extensive hydrogen-bonded networks. Density functional theory (DFT) calculations were carried out to model the enantiopure PO linear chain and the glycidol dimers that are observed by STM. Similar calculations were carried out for racemic PO and glycidol structures. The calculated interaction energies for the enantiopure and the racemic pairs reveal that there is no difference for homochiral versus heterochiral structures for both PO and glycidol on Pd(111).« less

Adsorption and Structure of Chiral Epoxides on Pd(111): Propylene Oxide and Glycidol

DOE PAGES

Mahapatra, Mausumi; Tysoe, Wilfred T.

2018-01-03

Here, the adsorption of enantiopure versus racemic propylene oxide (PO) on Pd(111) is studied by temperature-programmed desorption (TPD) to explore possible differences in their saturation coverage. It is found that that the saturation coverage of enantiopure PO on Pd(111) is identical to that of racemic PO, in contrast to results on Pt(111) where significant coverage differences were found. The surface structures of enantiopure PO on Pd(111) were characterized by scanning tunneling microscopy (STM), which shows the formation of linear chains and hexagonal structures proposed to be due to freely rotating PO, in contrast to the relatively disordered PO overlayers foundmore » on Pt(111). STM experiments were carried out for enantiopure glycidol, which contains the same epoxy ring as PO, but where the methyl group of propylene oxide is replaced by a -CH 2OH group to provide a hydrogen-bonding sites. Glycidol STM images show the formation of completely different surface structures; at low coverages, glycidol forms pseudohexagonal structures which assemble from glycidol dimers, while at high coverages the surface shows extensive hydrogen-bonded networks. Density functional theory (DFT) calculations were carried out to model the enantiopure PO linear chain and the glycidol dimers that are observed by STM. Similar calculations were carried out for racemic PO and glycidol structures. The calculated interaction energies for the enantiopure and the racemic pairs reveal that there is no difference for homochiral versus heterochiral structures for both PO and glycidol on Pd(111).« less

Structure, bonding nature, and binding energy of alkanethiolate on As-rich GaAs (001) surface: a density functional theory study.

PubMed

Voznyy, Oleksandr; Dubowski, Jan J

2006-11-30

Chemisorption of alkanethiols on As-rich GaAs (001) surface under a low coverage condition was studied using first principles density functional calculations in a periodic supercell approach. The thiolate adsorption site, tilt angle and its direction are dictated by the high directionality of As dangling bond and sulfur 3p orbital participating in bonding and steric repulsion of the first three CH2 units from the surface. Small charge transfer between thiolate and surface, strong dependence of total energy on tilt angle, and a relatively short length of 2.28 A of the S-As bond indicate the highly covalent nature of the bonding. Calculated binding energy of 2.1 eV is consistent with the available experimental data.

Volumetrically-Derived Global Navigation Satellite System Performance Assessment from the Earths Surface through the Terrestrial Service Volume and the Space Service Volume

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2016-01-01

NASA is participating in the International Committee on Global Navigation Satellite Systems (GNSS) (ICG)'s efforts towards demonstrating the benefits to the space user from the Earth's surface through the Terrestrial Service Volume (TSV) to the edge of the Space Service Volume (SSV), when a multi-GNSS solution space approach is utilized. The ICG Working Group: Enhancement of GNSS Performance, New Services and Capabilities has started a three phase analysis initiative as an outcome of recommendations at the ICG-10 meeting, in preparation for the ICG-11 meeting. The first phase of that increasing complexity and fidelity analysis initiative was recently expanded to compare nadir-facing and zenith-facing user hemispherical antenna coverage with omnidirectional antenna coverage at different distances of 8,000 km altitude and 36,000 km altitude. This report summarizes the performance using these antenna coverage techniques at distances ranging from 100 km altitude to 36,000 km to be all encompassing, as well as the volumetrically-derived system availability metrics.

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

Liu, Tao; Wang, Yan; Luo, Xiaozhou

Disulfide bonds play an important role in protein folding and stability. However, the cross-linking of sites within proteins by cysteine disulfides has significant distance and dihedral angle constraints. In this paper, we report the genetic encoding of noncanonical amino acids containing long side-chain thiols that are readily incorporated into both bacterial and mammalian proteins in good yields and with excellent fidelity. These amino acids can pair with cysteines to afford extended disulfide bonds and allow cross-linking of more distant sites and distinct domains of proteins. To demonstrate this notion, we preformed growth-based selection experiments at nonpermissive temperatures using a librarymore » of random β-lactamase mutants containing these noncanonical amino acids. A mutant enzyme that is cross-linked by one such extended disulfide bond and is stabilized by ~9 °C was identified. Finally, this result indicates that an expanded set of building blocks beyond the canonical 20 amino acids can lead to proteins with improved properties by unique mechanisms, distinct from those possible through conventional mutagenesis schemes.« less

Identification of phases, symmetries and defects through local crystallography

DOE PAGES

Belianinov, Alex; He, Qian; Kravchenko, Mikhail; ...

2015-07-20

Here we report that advances in electron and probe microscopies allow 10 pm or higher precision in measurements of atomic positions. This level of fidelity is sufficient to correlate the length (and hence energy) of bonds, as well as bond angles to functional properties of materials. Traditionally, this relied on mapping locally measured parameters to macroscopic variables, for example, average unit cell. This description effectively ignores the information contained in the microscopic degrees of freedom available in a high-resolution image. Here we introduce an approach for local analysis of material structure based on statistical analysis of individual atomic neighbourhoods. Clusteringmore » and multivariate algorithms such as principal component analysis explore the connectivity of lattice and bond structure, as well as identify minute structural distortions, thus allowing for chemical description and identification of phases. This analysis lays the framework for building image genomes and structure–property libraries, based on conjoining structural and spectral realms through local atomic behaviour.« less

Planning Coverage Campaigns for Mission Design and Analysis: CLASP for DESDynl

NASA Technical Reports Server (NTRS)

Knight, Russell L.; McLaren, David A.; Hu, Steven

2013-01-01

Mission design and analysis presents challenges in that almost all variables are in constant flux, yet the goal is to achieve an acceptable level of performance against a concept of operations, which might also be in flux. To increase responsiveness, automated planning tools are used that allow for the continual modification of spacecraft, ground system, staffing, and concept of operations, while returning metrics that are important to mission evaluation, such as area covered, peak memory usage, and peak data throughput. This approach was applied to the DESDynl mission design using the CLASP planning system, but since this adaptation, many techniques have changed under the hood for CLASP, and the DESDynl mission concept has undergone drastic changes. The software produces mission evaluation products, such as memory highwater marks, coverage percentages, given a mission design in the form of coverage targets, concept of operations, spacecraft parameters, and orbital parameters. It tries to overcome the lack of fidelity and timeliness of mission requirements coverage analysis during mission design. Previous techniques primarily use Excel in ad hoc fashion to approximate key factors in mission performance, often falling victim to overgeneralizations necessary in such an adaptation. The new program allows designers to faithfully represent their mission designs quickly, and get more accurate results just as quickly.

Effect of hydrogen coverage on hydrogenation of o-cresol on Pt(111)

NASA Astrophysics Data System (ADS)

Li, Yaping; Liu, Zhimin; Crossley, Steven P.; Jentoft, Friederike C.; Wang, Sanwu

2018-06-01

The conversion of phenolics over metal catalysts is an important process for upgrading biofuels. With density functional calculations, hydrogenation of o-cresol on the hydrogen-covered Pt(111) surface was investigated. The results show that the coverage of hydrogen plays a significant role in the reaction rate while it does not affect the reaction selectivity. The reaction barriers of the hydrogenation process leading to the formation of both 2-methyl-cyclohexanone (the intermediate product) and 2-methyl-cyclohexanol (the final product) at high H coverages (∼1 ML) are found to be smaller by 0.14-0.69 eV than those at lower H coverages (∼1/25 ML). After both hydrogen and cresol are adsorbed on Pt(111) from their initial gas phase state, the reaction energy of each hydrogenation step on the surface is also dependent on the hydrogen coverage. On the H-covered Pt(111) surface, most steps of hydrogenation involve exothermic reactions when the hydrogen coverage is high while they are endothermic reactions at low hydrogen coverages. The differences in reaction rate and reaction energy between high and low H coverages can be understood with the coverage-dependent bonding strength and configurations.

Sequence-Selective Formation of Synthetic H-Bonded Duplexes

PubMed Central

2017-01-01

Oligomers equipped with a sequence of phenol and pyridine N-oxide groups form duplexes via H-bonding interactions between these recognition units. Reductive amination chemistry was used to synthesize all possible 3-mer sequences: AAA, AAD, ADA, DAA, ADD, DAD, DDA, and DDD. Pairwise interactions between the oligomers were investigated using NMR titration and dilution experiments in toluene. The measured association constants vary by 3 orders of magnitude (102 to 105 M–1). Antiparallel sequence-complementary oligomers generally form more stable complexes than mismatched duplexes. Mismatched duplexes that have an excess of H-bond donors are stabilized by the interaction of two phenol donors with one pyridine N-oxide acceptor. Oligomers that have a H-bond donor and acceptor on the ends of the chain can fold to form intramolecular H-bonds in the free state. The 1,3-folding equilibrium competes with duplex formation and lowers the stability of duplexes involving these sequences. As a result, some of the mismatch duplexes are more stable than some of the sequence-complementary duplexes. However, the most stable mismatch duplexes contain DDD and compete with the most stable sequence-complementary duplex, AAA·DDD, so in mixtures that contain all eight sequences, sequence-complementary duplexes dominate. Even higher fidelity sequence selectivity can be achieved if alternating donor–acceptor sequences are avoided. PMID:28857551

Fluorine atom abstraction by Si(100). I. Experimental

NASA Astrophysics Data System (ADS)

Tate, M. R.; Gosalvez-Blanco, D.; Pullman, D. P.; Tsekouras, A. A.; Li, Y. L.; Yang, J. J.; Laughlin, K. B.; Eckman, S. C.; Bertino, M. F.; Ceyer, S. T.

1999-08-01

In the interaction of low energy F2 with Si(100) at 250 K, a dissociative chemisorption mechanism called atom abstraction is identified in which only one of the F atoms is adsorbed while the other F atom is scattered into the gas phase. The dynamics of atom abstraction are characterized via time-of-flight measurements of the scattered F atoms. The F atoms are translationally hyperthermal but only carry a small fraction (˜3%) of the tremendous exothermicity of the reaction. The angular distribution of F atoms is unusually broad for the product of an exothermic reaction. These results suggest an "attractive" interaction potential between F2 and the Si dangling bond with a transition state that is not constrained geometrically. These results are in disagreement with the results of theoretical investigations implying that the available potential energy surfaces are inadequate to describe the dynamics of this gas-surface interaction. In addition to single atom abstraction, two atom adsorption, a mechanism analogous to classic dissociative chemisorption in which both F atoms are adsorbed onto the surface, is also observed. The absolute probability of the three scattering channels (single atom abstraction, two atom adsorption, and unreactive scattering) for an incident F2 are determined as a function of F2 exposure. The fluorine coverage is determined by integrating the reaction probabilities over F2 exposure, and the reaction probabilities are recast as a function of fluorine coverage. Two atom adsorption is the dominant channel [P2=0.83±0.03(95%, N=9)] in the limit of zero coverage and decays monotonically to zero. Single atom abstraction is the minor channel (P1=0.13±0.03) at low coverage but increases to a maximum (P1=0.35±0.08) at about 0.5 monolayer (ML) coverage before decaying to zero. The reaction ceases at 0.94±0.11(95%, N=9) ML. Thermal desorption and helium diffraction confirm that the dangling bonds are the abstraction and adsorption sites. No Si lattice bonds are broken, in contrast to speculation by other investigators that the reaction exothermicity causes lattice disorder.

Linear modeling of steady-state behavioral dynamics.

PubMed Central

Palya, William L; Walter, Donald; Kessel, Robert; Lucke, Robert

2002-01-01

The observed steady-state behavioral dynamics supported by unsignaled periods of reinforcement within repeating 2,000-s trials were modeled with a linear transfer function. These experiments employed improved schedule forms and analytical methods to improve the precision of the measured transfer function, compared to previous work. The refinements include both the use of multiple reinforcement periods that improve spectral coverage and averaging of independently determined transfer functions. A linear analysis was then used to predict behavior observed for three different test schedules. The fidelity of these predictions was determined. PMID:11831782

Surface chemistry of PH 3, PF 3 and PCl 3 on Ru(0001)

NASA Astrophysics Data System (ADS)

Tao, H.-S.; Diebold, U.; Shinn, N. D.; Madey, T. E.

1994-06-01

The adsorption, desorption and decomposition of PH 3, PF 3 and PCl 3 on Ru(0001) have been studied by soft X-ray photoelectron spectroscopy (SXPS) using synchrotron radiation. Due to large chemical shifts in the P 2p core levels, different phosphorus containing surface species can be identified. We find that PF 3 adsorbs molecularly on Ru(0001) at 80 and 300 K. At 80 K, PH 3 saturates the surface with one layer of atomic hydrogen, elemental phosphorus, subhydride (i.e., PHx (0 < x < 3)) and PH 3, with a total phosphorus coverage of 0.4 ML. At 300 K, PH 3 decomposes into atomic hydrogen and elemental phosphorus with a phosphorus coverage of 0.8 ML. At 80 K, PCl 3 adsorbs dissociatively into atomic chlorine, elemental phosphorus, PCl and possibly PCl 2 and PCl 3 in the first monolayer. Formation of multilayers of PCl 3 is observed at 80 K. At 300 K, PCl 3 adsorbs dissociatively as atomic chlorine and elemental phosphorus with a saturation phosphorus coverage of 0.1 ML. The variation in total phosphorus uptake at 300 K from PX3 ( X = H, FandCl) adsorption is a result of competition between site blocking by dissociation fragments and displacement reactions. Annealing surfaces with adsorbed phosphorus to 1000 K results in formation of RuzP ( z = 1 or 2), which is manifested by the chemical shifts in the P2p core level, as well as the P LVV Auger transition. The recombination of adsorbed phosphorus and adsorbed X ( = H, FandCl) from decomposition is also observed, but is a minor reaction channel on the surface. Thermochemical data are used to analyze the different stabilities of PX 3 at 300 K, namely, PF 3 adsorbs molecularly and PH 3 and PCl 3 dissociate completely. First, we compare the heat of molecular adsorption and the heat of dissociative adsorption of PX 3 on Ru(0001), using an enthalpy approach, and find results consistent with experimental observations. Second, we compare the total bond energy difference between molecular adsorption and complete dissociation of PX 3 on Ru(0001). In particular, we apply Shustorovich's bond-order conservation-Morse potential (BOC-MP) method to estimate the heat of adsorption for PH 3 and PCl 3 and the bond energies of the relaxed P-X bonds of the adsorbed PX 3 on the surface. The bond strength difference among the relaxed P-X bonds (i.e., the relaxed P-F bond ( 475 {kJ}/{mol}) is much stronger than either the relaxed P-H bond ( 287 {kJ}/{mol}) or the relaxed P-Cl bond ( 288 {kJ}/{mol})) suggests that PF 3 is more stable than PH 3 and PCl 3 on Ru(0001) at 300 K. These values are used to evaluate the total bond energy differences between molecular adsorption and complete dissociation for each of the PX 3, and the results agree with the experimental trends.

The decision process used for hospital bond rating--and its implications.

PubMed Central

Cleverley, W O; Nutt, P C

1984-01-01

Investigation of the process of hospital bond rating related the ratings assigned by Moody's and Standard and Poors to indicators of hospital financial condition (such as debt per bed and peak debt coverage), institutional factors (including size, occupancy, and local market competition), indenture provisions (such as reserves), and contextual factors. The criteria used by Moody's and Standard and Poors to rate hospital bonds were revealed to be similar, but not identical. Criteria used in the bond rating process have several important implications: the rating approach provides strong financial incentives for increases in hospital size and complexity, for example, and hospitals that rely on extensive amounts of public financing appear to be penalized in the rating process. PMID:6500959

Site Fidelity, Associations and Long-Term Bonds of Short-Finned Pilot Whales off the Island of Hawai’i

DTIC Science & Technology

2012-01-01

matching was done visually using ACDSee 8.0 and 10 Photo Manager Software. Photographic encounters were processed using previously established protocols...1-4 (1=poor, 2=fair, 3=good, 4=excellent) using several criteria such as the focal clarity, size of animal in the frame, image contrast, and angle...the image needed to be of good to excellent focal clarity, positioned squarely with respect to 31 the photographer, etc. Similarly, the

Variation in social systems within Chaetodon butterflyfishes, with special reference to pair bonding

PubMed Central

O’Connell, Lauren A.; Cowman, Peter F.; Walker, Stefan P. W.; Coker, Darren J.; Pratchett, Morgan S.

2018-01-01

For many animals, affiliative relationships such as pair bonds form the foundation of society and are highly adaptive. Animal systems amenable for comparatively studying pair bonding are important for identifying underlying biological mechanisms, but mostly exist in mammals. Better establishing fish systems will enable comparison of pair bonding mechanisms across taxonomically distant lineages that may reveal general underlying mechanistic principles. We examined the utility of wild butterflyfishes (f: Chaetodontidae; g: Chaetodon) for comparatively studying pair bonding. Using stochastic character mapping, we provide the first analysis of the evolutionary history of butterflyfish sociality, revealing that pairing is ancestral, with at least seven independent transitions to gregarious grouping and solitary behavior since the late Miocene. We then formally verified social systems in six sympatric and wide-spread species representing a clade with one ancestrally reconstructed transition from paired to solitary grouping at Lizard Island, Australia. In situ observations of the size, selective affiliation and aggression, fidelity, and sex composition of social groups confirmed that Chaetodon baronessa, C. lunulatus, and C. vagabundus are predominantly pair bonding, whereas C. rainfordi, C. plebeius, and C. trifascialis are predominantly solitary. Even in the predominantly pair bonding species, C. lunulatus, a proportion of adults (15%) are solitary. Importantly, inter- and intra-specific differences in social systems do not co-vary with other previously established attributes, including parental care. Hence, the proposed butterflyfish populations are promising for inter- and intra-species comparative analyses of pair bonding and its mechanistic underpinnings. Avenues for further developing the system are proposed, including determining whether the aforementioned utility of these species applies across their geographic disruptions. PMID:29641529

Variation in social systems within Chaetodon butterflyfishes, with special reference to pair bonding.

PubMed

Nowicki, Jessica P; O'Connell, Lauren A; Cowman, Peter F; Walker, Stefan P W; Coker, Darren J; Pratchett, Morgan S

2018-01-01

For many animals, affiliative relationships such as pair bonds form the foundation of society and are highly adaptive. Animal systems amenable for comparatively studying pair bonding are important for identifying underlying biological mechanisms, but mostly exist in mammals. Better establishing fish systems will enable comparison of pair bonding mechanisms across taxonomically distant lineages that may reveal general underlying mechanistic principles. We examined the utility of wild butterflyfishes (f: Chaetodontidae; g: Chaetodon) for comparatively studying pair bonding. Using stochastic character mapping, we provide the first analysis of the evolutionary history of butterflyfish sociality, revealing that pairing is ancestral, with at least seven independent transitions to gregarious grouping and solitary behavior since the late Miocene. We then formally verified social systems in six sympatric and wide-spread species representing a clade with one ancestrally reconstructed transition from paired to solitary grouping at Lizard Island, Australia. In situ observations of the size, selective affiliation and aggression, fidelity, and sex composition of social groups confirmed that Chaetodon baronessa, C. lunulatus, and C. vagabundus are predominantly pair bonding, whereas C. rainfordi, C. plebeius, and C. trifascialis are predominantly solitary. Even in the predominantly pair bonding species, C. lunulatus, a proportion of adults (15%) are solitary. Importantly, inter- and intra-specific differences in social systems do not co-vary with other previously established attributes, including parental care. Hence, the proposed butterflyfish populations are promising for inter- and intra-species comparative analyses of pair bonding and its mechanistic underpinnings. Avenues for further developing the system are proposed, including determining whether the aforementioned utility of these species applies across their geographic disruptions.

Peierls instability as the insulating origin of the Na/Si(111)-(3 × 1) surface with a Na coverage of 2/3 monolayers

NASA Astrophysics Data System (ADS)

Kang, Myung Ho; Kwon, Se Gab; Jung, Sung Chul

2018-03-01

Density functional theory (DFT) calculations are used to investigate the insulating origin of the Na/Si(111)-(3 × 1) surface with a Na coverage of 2/3 monolayers. In the coverage definition, one monolayer refers to one Na atom per surface Si atom, so this surface contains an odd number of electrons (i.e., three Si dangling-bond electrons plus two Na electrons) per 3 × 1 unit cell. Interestingly, this odd-electron surface has been ascribed to a Mott-Hubbard insulator to account for the measured insulating band structure with a gap of about 0.8 eV. Here, we instead propose a Peierls instability as the origin of the experimental band gap. The concept of Peierls instability is fundamental in one-dimensional metal systems but has not been taken into account in previous studies of this surface. Our DFT calculations demonstrate that the linear chain structure of Si dangling bonds in this surface is energetically unstable with respect to a × 2 buckling modulation, and the buckling-induced band gap of 0.79 eV explains well the measured insulating nature.

Prediction of fracture toughness and durability of adhesively bonded composite joints with undesirable bonding conditions

NASA Astrophysics Data System (ADS)

Musaramthota, Vishal

Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ's). ABCJ's negate the introduction of stress risers that are associated with riveting or other classical techniques. In today's aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ's. Of particular interest are the short term strength, contamination and long term durability of ABCJ's. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft's service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ's comprising severe environmental conditioning, fatiguing in ambient air and a combination of both. The bonds produced were durable enough to sustain the tests cases mentioned above when conditioned for 8 weeks and did not experience any loss in strength. Specimens that were aged for 80 weeks showed a degradation of 10% in their fracture toughness when compared to their baseline datasets. The effect of various exposure times needs to be further evaluated to establish the relationship of durability that is associated with the fracture toughness of ABCJ's.

Hydrogen bonding and interparticle forces in platelet alpha-Al2O3 dispersions: yield stress and zeta potential.

PubMed

Khoo, Kay-Sen; Teh, E-Jen; Leong, Yee-Kwong; Ong, Ban Choon

2009-04-09

Adsorbed phosphate on smooth platelet alpha-Al2O3 particles at saturation surface coverage gives rise to strong interparticle attractive forces in dispersion. The maximum yield stress at the point of zero charge was increased by 2-fold. This was attributed to a high density of intermolecular hydrogen bonding between the adsorbed phosphate layers of the interacting particles. Adsorbed citrate at saturation surface coverage, however, reduced the maximum yield stress by 50%. It adsorbed to form a very effective steric barrier as intramolecular hydrogen bonding between -OH and the free terminal carboxylic group prevented strong interactions with other adsorbed citrate molecules residing on the second interacting particle. This steric barrier kept the interacting platelet particles further apart, thereby weakening the van der Waals attraction. The platelet alpha-Al2O3 dispersions were flocculated at all pH level. These dispersions displayed a maximum yield stress at the point of zero zeta potential at the pH approximately 8.0. They also obeyed the yield stress-DLVO force model as characterized by a linear decrease in the yield stress with the square of the zeta potential.

75 FR 48525 - Pennsylvania Regulatory Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

...OSM is announcing its partial approval of a program amendment submitted by the Commonwealth of Pennsylvania for the purpose of addressing the need for financial guarantees to cover the costs of treatment of post-mining pollutional discharges and land reclamation for those surface coal mining sites that were originally bonded under the Commonwealth's now defunct alternative bonding system (ABS). OSM is requiring that Pennsylvania ensure that its program provides suitable, enforceable funding mechanisms sufficient to guarantee coverage of land reclamation at all original ABS sites.

Long-distance entanglement and quantum teleportation in XX spin chains

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

Campos Venuti, L.; Giampaolo, S. M.; CNR-INFM Coherentia, Napoli

2007-11-15

Isotropic XX models of one-dimensional spin-1/2 chains are investigated with the aim to elucidate the formal structure and the physical properties that allow these systems to act as channels for long-distance, high-fidelity quantum teleportation. We introduce two types of models: (i) open, dimerized XX chains, and (ii) open XX chains with small end bonds. For both models we obtain the exact expressions for the end-to-end correlations and the scaling of the energy gap with the length of the chain. We determine the end-to-end concurrence and show that model (i) supports true long-distance entanglement at zero temperature, while model (ii) supportsmore » 'quasi-long-distance' entanglement that slowly falls off with the size of the chain. Due to the different scalings of the gaps, respectively exponential for model (i) and algebraic in model (ii), we demonstrate that the latter allows for efficient qubit teleportation with high fidelity in sufficiently long chains even at moderately low temperatures.« less

27 CFR 40.396 - Change in proprietorship.

Code of Federal Regulations, 2010 CFR

2010-04-01

... appropriate TTB officer, an administrator, executor, receiver, trustee, assignee, or other fiduciary successor... qualification of any administrator, executor, receiver, trustee, assignee, or other fiduciary, together with an extension of coverage of the predecessor's bond executed by the administrator, executor, receiver, trustee...

48 CFR 728.307-2 - Liability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Section 728.307-2 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 728.307-2 Liability. (a)-(b) [Reserved] (c) Automobile... an USAID contract are properly insured, USAID has established minimum required coverages as a...

48 CFR 728.307-2 - Liability.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Section 728.307-2 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 728.307-2 Liability. (a)-(b) [Reserved] (c) Automobile... an USAID contract are properly insured, USAID has established minimum required coverages as a...

Fractal-based wideband invisibility cloak

NASA Astrophysics Data System (ADS)

Cohen, Nathan; Okoro, Obinna; Earle, Dan; Salkind, Phil; Unger, Barry; Yen, Sean; McHugh, Daniel; Polterzycki, Stefan; Shelman-Cohen, A. J.

2015-03-01

A wideband invisibility cloak (IC) at microwave frequencies is described. Using fractal resonators in closely spaced (sub wavelength) arrays as a minimal number of cylindrical layers (rings), the IC demonstrates that it is physically possible to attain a `see through' cloaking device with: (a) wideband coverage; (b) simple and attainable fabrication; (c) high fidelity emulation of the free path; (d) minimal side scattering; (d) a near absence of shadowing in the scattering. Although not a practical device, this fractal-enabled technology demonstrator opens up new opportunities for diverted-image (DI) technology and use of fractals in wideband optical, infrared, and microwave applications.

Galaxies and cosmology with ALMA

NASA Astrophysics Data System (ADS)

Planesas, P.

2011-12-01

Intensive work is being carried out at the Joint ALMA Observatory in order to bring four bands of a 16-antenna mm/submm interferometer into scientific operation. Specific tests of the advertised capabilities for Early Science are being carried out as well as further tests in order to bring ALMA into full operation as planned. Some of the measurements were taken towards extragalactic objects. In fact, the high sensitivity, high angular resolution, high image fidelity, and high mapping speed, together with a large frequency coverage, will make ALMA the right instrument for high redshift studies, and detailed dynamical and chemical studies of nearby galaxies.

The use of modified and non-natural nucleotides provide unique insights into pro-mutagenic replication catalyzed by polymerase eta

PubMed Central

Choi, Jung-Suk; Dasari, Anvesh; Hu, Peter; Benkovic, Stephen J.; Berdis, Anthony J.

2016-01-01

This report evaluates the pro-mutagenic behavior of 8-oxo-guanine (8-oxo-G) by quantifying the ability of high-fidelity and specialized DNA polymerases to incorporate natural and modified nucleotides opposite this lesion. Although high-fidelity DNA polymerases such as pol δ and the bacteriophage T4 DNA polymerase replicating 8-oxo-G in an error-prone manner, they display remarkably low efficiencies for TLS compared to normal DNA synthesis. In contrast, pol η shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties are consistent with a pro-mutagenic role for pol η when replicating this DNA lesion. Studies using modified nucleotide analogs show that pol η relies heavily on hydrogen-bonding interactions during translesion DNA synthesis. However, nucleobase modifications such as alkylation to the N2 position of guanine significantly increase error-prone synthesis catalyzed by pol η when replicating 8-oxo-G. Molecular modeling studies demonstrate the existence of a hydrophobic pocket in pol η that participates in the increased utilization of certain hydrophobic nucleotides. A model is proposed for enhanced pro-mutagenic replication catalyzed by pol η that couples efficient incorporation of damaged nucleotides opposite oxidized DNA lesions created by reactive oxygen species. The biological implications of this model toward increasing mutagenic events in lung cancer are discussed. PMID:26717984

First-principle study of geometric stabilities, electronic and magnetic properties of low coverage vanadium adsorption on graphene

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

Abdullahi, Yusuf Zuntu; Rahman, Md. Mahmudur, E-mail: mahmudur@upm.edu.my; Zainuddin, H.

2014-03-05

Stable geometries, electronic and magnetic properties of low coverage vanadium (V) atoms adsorption on graphene sheet have been investigated by first principles calculations, using generalized gradient approximation. Calculation shows that center of the ring is energetically favorable for both V adatom and perpendicular dimer after relaxation. Moreover, the proportion of orbital contribution of C-V bonding are mainly dominated by 2p{sub z} orbital of C and partially occupied by the 3d like states of V. It is also found that the low coverage V atom adsorbed graphene system is metallic and magnetic, and has demonstrated additional hint on its usefulness inmore » magnetic devices.« less

Mechanical properties of highly defective graphene: from brittle rupture to ductile fracture.

PubMed

Xu, Lanqing; Wei, Ning; Zheng, Yongping

2013-12-20

Defects are generally believed to deteriorate the superlative performance of graphene-based devices but may also be useful when carefully engineered to tailor the local properties and achieve new functionalities. Central to most defect-associated applications is the defect coverage and arrangement. In this work, we investigate, by molecular dynamics simulations, the mechanical properties and fracture dynamics of graphene sheets with randomly distributed vacancies or Stone-Wales defects under tensile deformations over a wide defect coverage range. With defects presented, an sp-sp(2) bonding network and an sp-sp(2)-sp(3) bonding network are observed in vacancy-defected and Stone-Wales-defected graphene, respectively. The ultimate strength degrades gradually with increasing defect coverage and saturates in the high-ratio regime, whereas the fracture strain presents an unusual descending-saturating-improving trend. In the dense vacancy defect situation, the fracture becomes more plastic and super-ductility is observed. Further fracture dynamics analysis reveals that the crack trapping by sp-sp(2) and sp-sp(2)-sp(3) rings and the crack-tip blunting account for the ductile fracture, whereas geometric rearrangement on the entire sheet for vacancy defects and geometric rearrangement on the specific defect sites for Stone-Wales defects account for their distinctive rules of the evolution of the fracture strain.

The Sapphire (0001) Surface, Clean and with d-metal Overlayers: Density Functional - LDA Results

NASA Astrophysics Data System (ADS)

Verdozzi, C.; Jennison, D. R.; Schultz, P. A.; Sears, M. P.

1998-03-01

Previous theoretical work for the a-Al2O3(0001) surface mostly used very thin slabs, and limited theoretical information is available on the binding of metal overlayers. Also, no systematic information is available about the dependence of the metal-ceramic interaction on metal coverage. We present here results using the local density approximation for the structural and electronic properties of the a-Al2O3(0001) surface, with and without d-metal overlayers Pt, Ag, Cu, and with sufficiently thick slabs to find the bottom of the unusually large and deep surface relaxation in this material. Our thick slab site-optimized calculations are performed for 1, 2/3 and 1/3 monolayer (ML) coverage. The adhesion energy and the nature of the interfacial bond vary greatly with metal coverage and can be understood in terms of the relative roles of the surface Madelung potential and the strength of the lateral metal-metal bond. Our study should in principle succeed in bracketing the phenomenology of adhesion and wetting at least for the right-most part of the d-metal periodic table. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000. Corresponding author: claudio@sandia.gov.

Influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage restorations.

PubMed

Bakeman, E M; Rego, N; Chaiyabutr, Y; Kois, J C

2015-01-01

This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (p<0.001); however, the thickness of ceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (p<0.05). There was no significant difference in fracture resistance values between a lithium disilicate ceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

Dynamic Assessment of the Endothelialization of Tissue-Engineered Blood Vessels Using an Optical Coherence Tomography Catheter-Based Fluorescence Imaging System.

PubMed

Gurjarpadhye, Abhijit Achyut; DeWitt, Matthew R; Xu, Yong; Wang, Ge; Rylander, Marissa Nichole; Rylander, Christopher G

2015-07-01

Lumen endothelialization of bioengineered vascular scaffolds is essential to maintain small-diameter graft patency and prevent thrombosis postimplantation. Unfortunately, nondestructive imaging methods to visualize this dynamic process are lacking, thus slowing development and clinical translation of these potential tissue-engineering approaches. To meet this need, a fluorescence imaging system utilizing a commercial optical coherence tomography (OCT) catheter was designed to visualize graft endothelialization. C7 DragonFly™ intravascular OCT catheter was used as a channel for delivery and collection of excitation and emission spectra. Poly-dl-lactide (PDLLA) electrospun scaffolds were seeded with endothelial cells (ECs). Seeded cells were exposed to Calcein AM before imaging, causing the living cells to emit green fluorescence in response to blue laser. By positioning the catheter tip precisely over a specimen using high-fidelity electromechanical components, small regions of the specimen were excited selectively. The resulting fluorescence intensities were mapped on a two-dimensional digital grid to generate spatial distribution of fluorophores at single-cell-level resolution. Fluorescence imaging of endothelialization on glass and PDLLA scaffolds was performed using the OCT catheter-based imaging system as well as with a commercial fluorescence microscope. Cell coverage area was calculated for both image sets for quantitative comparison of imaging techniques. Tubular PDLLA scaffolds were maintained in a bioreactor on seeding with ECs, and endothelialization was monitored over 5 days using the OCT catheter-based imaging system. No significant difference was observed in images obtained using our imaging system to those acquired with the fluorescence microscope. Cell area coverage calculated using the images yielded similar values. Nondestructive imaging of endothelialization on tubular scaffolds showed cell proliferation with cell coverage area increasing from 15 ± 4% to 89 ± 6% over 5 days. In this study, we showed the capability of an OCT catheter-based imaging system to obtain single-cell resolution and to quantify endothelialization in tubular electrospun scaffolds. We also compared the resulting images with traditional microscopy, showing high fidelity in image capability. This imaging system, used in conjunction with OCT, could potentially be a powerful tool for in vitro optimization of scaffold cellularization, ensuring long-term graft patency postimplantation.

Characterization and reactivity of organic monolayers on gold and platinum surfaces

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

Wu, Chien-Ching

1995-12-06

Purpose is to understand how the mobilization, dielectric, orientation, composition, coverage, and structure of self-assembled organic monolayers on metal surfaces affects the surface reactivities and properties of these films in order to facilitate the construction of desired films. Two model systems were used: tiols at Au and aromatic acids at Pt. Surface analysis methods, including contact angle, electrochemistry, ellipsometry, infrared reflection absorption spectroscopy (IRRAS), and x-ray photospectroscopy, were used to study the self-assembled organic monolayers on Au and Pt. IRRAS, contact angle, and electrochemistry were used to determine the surface pK a of phenylcarboxylic acids and pyridylcarboxylic acids monolayers onmore » Pt. These techniques were also used to determine the orientation of polymethylene chain axis and the carboxylic follow the structural evolution of the chains and end group of the thiolate monolayers during formation. IRRAS was also used to assess the carboxylic acid group in terms of its possible existence as the non-hydrogen-bonded species, the hydrogen-bonded dimeric group, and the hydrogen-bonded polymeric group. These different forms of the end group were also followed vs coverage, as well as the reactivity vs solution pH. IRRAS and contact angle were used to calculate the rate constant of the esterification of carboxylic acid-terminated monolayers on Au.« less

Room-temperature activation of methane and dry re-forming with CO 2 on Ni-CeO 2 (111) surfaces: Effect of Ce 3+ sites and metal–support interactions on C–H bond cleavage

DOE PAGES

Lustemberg, Pablo G.; Ramírez, Pedro J.; Liu, Zongyuan; ...

2016-10-27

The results of core-level photoemission indicate that Ni-CeO 2(111) surfaces with small or medium coverages of nickel are able to activate methane at 300 K, producing adsorbed CH x and CO x (x = 2, 3) groups. Calculations based on density functional theory predict a relatively low activation energy of 0.6–0.7 eV for the cleavage of the first C–H bond in the adsorbed methane molecule. Ni and O centers of ceria work in a cooperative way in the dissociation of the C–H bond at room temperature, where a low Ni loading is crucial for the catalyst activity and stability. Themore » strong electronic perturbations in the Ni nanoparticles produced by the ceria supports of varying natures, such as stoichiometric and reduced, result in a drastic change in their chemical properties toward methane adsorption and dissociation as well as the dry reforming of methane reaction. Lastly, the coverage of Ni has a drastic effect on the ability of the system to dissociate methane and catalyze the dry re-forming process.« less

Dynamics of self-assembled cytosine nucleobases on graphene

NASA Astrophysics Data System (ADS)

Saikia, Nabanita; Johnson, Floyd; Waters, Kevin; Pandey, Ravindra

2018-05-01

Molecular self-assembly of cytosine (C n ) bases on graphene was investigated using molecular dynamics methods. For free-standing C n bases, simulation conditions (gas versus aqueous) determine the nature of self-assembly; the bases prefer to aggregate in the gas phase and are stabilized by intermolecular H-bonds, while in the aqueous phase, the water molecules disrupt base-base interactions, which facilitate the formation of π-stacked domains. The substrate-induced effects, on the other hand, find the polarity and donor-acceptor sites of the bases to govern the assembly process. For example, in the gas phase, the assembly of C n bases on graphene displays short-range ordered linear arrays stabilized by the intermolecular H-bonds. In the aqueous phase, however, there are two distinct configurations for the C n bases assembly on graphene. For the first case corresponding to low surface coverage, the bases are dispersed on graphene and are isolated. The second configuration archetype is disordered linear arrays assembled with medium and high surface coverage. The simulation results establish the role of H-bonding, vdW π-stacking, and the influence of graphene surface towards the self-assembly. The ability to regulate the assembly into well-defined patterns can aid in the design of self-assembled nanostructures for the next-generation DNA based biosensors and nanoelectronic devices.

Room-temperature activation of methane and dry re-forming with CO 2 on Ni-CeO 2 (111) surfaces: Effect of Ce 3+ sites and metal–support interactions on C–H bond cleavage

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

Lustemberg, Pablo G.; Ramírez, Pedro J.; Liu, Zongyuan

The results of core-level photoemission indicate that Ni-CeO 2(111) surfaces with small or medium coverages of nickel are able to activate methane at 300 K, producing adsorbed CH x and CO x (x = 2, 3) groups. Calculations based on density functional theory predict a relatively low activation energy of 0.6–0.7 eV for the cleavage of the first C–H bond in the adsorbed methane molecule. Ni and O centers of ceria work in a cooperative way in the dissociation of the C–H bond at room temperature, where a low Ni loading is crucial for the catalyst activity and stability. Themore » strong electronic perturbations in the Ni nanoparticles produced by the ceria supports of varying natures, such as stoichiometric and reduced, result in a drastic change in their chemical properties toward methane adsorption and dissociation as well as the dry reforming of methane reaction. Lastly, the coverage of Ni has a drastic effect on the ability of the system to dissociate methane and catalyze the dry re-forming process.« less

A study on the implementation fidelity of the performance-based financing policy in Burkina Faso after 12 months.

PubMed

Bodson, Oriane; Barro, Ahmed; Turcotte-Tremblay, Anne-Marie; Zanté, Nestor; Somé, Paul-André; Ridde, Valéry

2018-01-01

Performance-based financing (PBF) in the health sector has recently gained momentum in low- and middle-income countries (LMICs) as one of the ways forward for achieving Universal Health Coverage. The major principle underlying PBF is that health centers are remunerated based on the quantity and quality of services they provide. PBF has been operating in Burkina Faso since 2011, and as a pilot project since 2014 in 15 health districts randomly assigned into four different models, before an eventual scale-up. Despite the need for expeditious documentation of the impact of PBF, caution is advised to avoid adopting hasty conclusions. Above all, it is crucial to understand why and how an impact is produced or not. Our implementation fidelity study approached this inquiry by comparing, after 12 months of operation, the activities implemented against what was planned initially and will make it possible later to establish links with the policy's impacts. Our study compared, in 21 health centers from three health districts, the implementation of activities that were core to the process in terms of content, coverage, and temporality. Data were collected through document analysis, as well as from individual interviews and focus groups with key informants. In the first year of implementation, solid foundations were put in place for the intervention. Even so, implementation deficiencies and delays were observed with respect to certain performance auditing procedures, as well as in payments of PBF subsidies, which compromised the incentive-based rationale to some extent. Over next months, efforts should be made to adjust the intervention more closely to context and to the original planning.

Reactivity of chemisorbed oxygen atoms and their catalytic consequences during CH4-O2 catalysis on supported Pt clusters.

PubMed

Chin, Ya-Huei Cathy; Buda, Corneliu; Neurock, Matthew; Iglesia, Enrique

2011-10-12

Kinetic and isotopic data and density functional theory treatments provide evidence for the elementary steps and the active site requirements involved in the four distinct kinetic regimes observed during CH(4) oxidation reactions using O(2), H(2)O, or CO(2) as oxidants on Pt clusters. These four regimes exhibit distinct rate equations because of the involvement of different kinetically relevant steps, predominant adsorbed species, and rate and equilibrium constants for different elementary steps. Transitions among regimes occur as chemisorbed oxygen (O*) coverages change on Pt clusters. O* coverages are given, in turn, by a virtual O(2) pressure, which represents the pressure that would give the prevalent steady-state O* coverages if their adsorption-desorption equilibrium was maintained. The virtual O(2) pressure acts as a surrogate for oxygen chemical potentials at catalytic surfaces and reflects the kinetic coupling between C-H and O═O activation steps. O* coverages and virtual pressures depend on O(2) pressure when O(2) activation is equilibrated and on O(2)/CH(4) ratios when this step becomes irreversible as a result of fast scavenging of O* by CH(4)-derived intermediates. In three of these kinetic regimes, C-H bond activation is the sole kinetically relevant step, but occurs on different active sites, which evolve from oxygen-oxygen (O*-O*), to oxygen-oxygen vacancy (O*-*), and to vacancy-vacancy (*-*) site pairs as O* coverages decrease. On O*-saturated cluster surfaces, O*-O* site pairs activate C-H bonds in CH(4) via homolytic hydrogen abstraction steps that form CH(3) groups with significant radical character and weak interactions with the surface at the transition state. In this regime, rates depend linearly on CH(4) pressure but are independent of O(2) pressure. The observed normal CH(4)/CD(4) kinetic isotope effects are consistent with the kinetic-relevance of C-H bond activation; identical (16)O(2)-(18)O(2) isotopic exchange rates in the presence or absence of CH(4) show that O(2) activation steps are quasi-equilibrated during catalysis. Measured and DFT-derived C-H bond activation barriers are large, because of the weak stabilization of the CH(3) fragments at transition states, but are compensated by the high entropy of these radical-like species. Turnover rates in this regime decrease with increasing Pt dispersion, because low-coordination exposed Pt atoms on small clusters bind O* more strongly than those that reside at low-index facets on large clusters, thus making O* less effective in H-abstraction. As vacancies (*, also exposed Pt atoms) become available on O*-covered surfaces, O*-* site pairs activate C-H bonds via concerted oxidative addition and H-abstraction in transition states effectively stabilized by CH(3) interactions with the vacancies, which lead to much higher turnover rates than on O*-O* pairs. In this regime, O(2) activation becomes irreversible, because fast C-H bond activation steps scavenge O* as it forms. Thus, O* coverages are set by the prevalent O(2)/CH(4) ratios instead of the O(2) pressures. CH(4)/CD(4) kinetic isotope effects are much larger for turnovers mediated by O*-* than by O*-O* site pairs, because C-H (and C-D) activation steps are required to form the * sites involved in C-H bond activation. Turnover rates for CH(4)-O(2) reactions mediated by O*-* pairs decrease with increasing Pt dispersion, as in the case of O*-O* active structures, because stronger O* binding on small clusters leads not only to less reactive O* atoms, but also to lower vacancy concentrations at cluster surfaces. As O(2)/CH(4) ratios and O* coverages become smaller, O(2) activation on bare Pt clusters becomes the sole kinetically relevant step; turnover rates are proportional to O(2) pressures and independent of CH(4) pressure and no CH(4)/CD(4) kinetic isotope effects are observed. In this regime, turnover rates become nearly independent of Pt dispersion, because the O(2) activation step is essentially barrierless. In the absence of O(2), alternate weaker oxidants, such as H(2)O or CO(2), lead to a final kinetic regime in which C-H bond dissociation on *-* pairs at bare cluster surfaces limit CH(4) conversion rates. Rates become first-order in CH(4) and independent of coreactant and normal CH(4)/CD(4) kinetic isotope effects are observed. In this case, turnover rates increase with increasing dispersion, because low-coordination Pt atoms stabilize the C-H bond activation transition states more effectively via stronger binding to CH(3) and H fragments. These findings and their mechanistic interpretations are consistent with all rate and isotopic data and with theoretical estimates of activation barriers and of cluster size effects on transition states. They serve to demonstrate the essential role of the coverage and reactivity of chemisorbed oxygen in determining the type and effectiveness of surface structures in CH(4) oxidation reactions using O(2), H(2)O, or CO(2) as oxidants, as well as the diversity of rate dependencies, activation energies and entropies, and cluster size effects that prevail in these reactions. These results also show how theory and experiments can unravel complex surface chemistries on realistic catalysts under practical conditions and provide through the resulting mechanistic insights specific predictions for the effects of cluster size and surface coordination on turnover rates, the trends and magnitude of which depend sensitively on the nature of the predominant adsorbed intermediates and the kinetically relevant steps.

Navigation of autonomous vehicles for oil spill cleaning in dynamic and uncertain environments

NASA Astrophysics Data System (ADS)

Jin, Xin; Ray, Asok

2014-04-01

In the context of oil spill cleaning by autonomous vehicles in dynamic and uncertain environments, this paper presents a multi-resolution algorithm that seamlessly integrates the concepts of local navigation and global navigation based on the sensory information; the objective here is to enable adaptive decision making and online replanning of vehicle paths. The proposed algorithm provides a complete coverage of the search area for clean-up of the oil spills and does not suffer from the problem of having local minima, which is commonly encountered in potential-field-based methods. The efficacy of the algorithm is tested on a high-fidelity player/stage simulator for oil spill cleaning in a harbour, where the underlying oil weathering process is modelled as 2D random-walk particle tracking. A preliminary version of this paper was presented by X. Jin and A. Ray as 'Coverage Control of Autonomous Vehicles for Oil Spill Cleaning in Dynamic and Uncertain Environments', Proceedings of the American Control Conference, Washington, DC, June 2013, pp. 2600-2605.

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

Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.

Angle-resolved photon stimulated desorption (PSD) combined with infrared reflection-adsorption spectroscopy and temperature programmed desorption reveal two distinct channels in the photochemistry of acetone on rutile TiO₂(110) surface. During UV irradiation of co-adsorbed oxygen and acetone molecules, methyl radicals (CH₃) are ejected in two different directions: i) normal to the surface and ii) off-normal at ~±66° to the surface normal in the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti atoms). Both components are relatively narrow and non-cosine, indicating non-thermal evolution of CH₃ radicals. The direction of the “off-normal” PSD component is consistent with orientation of the C–CH₃more » bonds in the n²-acetone diolate—a photoactive form of acetone chemisorption on the oxidized TiO₂(110) surface proposed earlier from experimental and theoretical studies. The direction of the “normal” PSD component requires an orientation of a C–CH₃ bond which is not consistent with the n²-acetone diolate structure. The angular distribution of the CH₃ PSD depends on the acetone coverage. The “off-normal” PSD component dominates at lower acetone coverage (< 0.2 ML), but does not increase at higher coverages in accord with the acetone diolate peak intensity in the infrared reflection-absorption spectra. The “normal” PSD component grows with the acetone coverage up to 0.6 ML. The newly discovered “normal” PSD channel is tentatively assigned to a photo-produced n²- acetone enolate as a potential precursor based on the H/D exchange experiments« less

Effect of 3 cements on white spot lesion formation after full-coverage rapid maxillary expander: A comparative in-vivo study.

PubMed

Yagci, Ahmet; Korkmaz, Yasemin Nur; Yagci, Filiz; Atilla, Aykan Onur; Buyuk, Suleyman Kutalmiş

2016-12-01

The aim of this study was to assess the effects of 3 luting agents (glass ionomer cement, compomer, and polycarboxylate cement) on white spot lesion formation in patients with full-coverage bonded acrylic splint expanders. White spot lesion formation was assessed with quantitative light-induced fluorescence. Full-coverage rapid maxillary expanders were cemented with glass ionomer cement, compomer, and polycarboxylate cement in groups 1, 2, and 3, respectively. A control group comprised patients who never had orthodontic treatment. Quantitative light-induced fluorescence images taken before and after rapid maxillary expansion treatment were analyzed for these parameters: the percentages of fluorescence loss with respect to the fluorescence of sound tooth tissue (ΔF) and maximum loss of fluorescence intensity in the whole lesion; lesion area with ΔF equal to less than a -5% threshold; and the percentage of fluorescence loss with respect to the fluorescence of sound tissue times the area that indicated lesion volume. All 3 groups showed statistically significantly greater demineralization than the control group. The 3 experimental groups differed from each other in half of the parameters calculated. Teeth in the polycarboxylate group developed the most white spot lesions. With the highest rate of white spot lesion formation, polycarboxylate cements should not be used for full-coverage bonded acrylic splint expanders. Compomers may be preferred over glass ionomer cements, based on the findings of this study. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

29 CFR 2580.412-2 - Plans exempt from the coverage of section 13.

Code of Federal Regulations, 2010 CFR

2010-07-01

... whole or in part, of dealing with employers concerning an employee welfare or pension benefit plan, or... Section 2580.412-2 Labor Regulations Relating to Labor (Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY BONDING RULES UNDER THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF...

48 CFR 1328.310-70 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... DEPARTMENT OF COMMERCE GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Insurance 1328.310-70... work is required on the Government installation (e.g., a few brief visits per month); or (ii) All the..., Insurance Coverage, is used. (e) Insert clauses 1352.228-73 through 1352.228-75, unless otherwise indicated...

Molecular marriage through partner preferences in covalent cage formation and cage-to-cage transformation.

PubMed

Acharyya, Koushik; Mukherjee, Sandip; Mukherjee, Partha Sarathi

2013-01-16

Unprecedented self-sorting of three-dimensional purely organic cages driven by dynamic covalent bonds is described. Four different cages were first synthesized by condensation of two triamines and two dialdehydes separately. When a mixture of all the components was allowed to react, only two cages were formed, which suggests a high-fidelity self-recognition. The issue of the preference of one triamine for a particular dialdehyde was further probed by transforming a non-preferred combination to either of the two preferred combinations by reacting it with the appropriate triamine or dialdehyde.

The use of modified and non-natural nucleotides provide unique insights into pro-mutagenic replication catalyzed by polymerase eta.

PubMed

Choi, Jung-Suk; Dasari, Anvesh; Hu, Peter; Benkovic, Stephen J; Berdis, Anthony J

2016-02-18

This report evaluates the pro-mutagenic behavior of 8-oxo-guanine (8-oxo-G) by quantifying the ability of high-fidelity and specialized DNA polymerases to incorporate natural and modified nucleotides opposite this lesion. Although high-fidelity DNA polymerases such as pol δ and the bacteriophage T4 DNA polymerase replicating 8-oxo-G in an error-prone manner, they display remarkably low efficiencies for TLS compared to normal DNA synthesis. In contrast, pol η shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties are consistent with a pro-mutagenic role for pol η when replicating this DNA lesion. Studies using modified nucleotide analogs show that pol η relies heavily on hydrogen-bonding interactions during translesion DNA synthesis. However, nucleobase modifications such as alkylation to the N2 position of guanine significantly increase error-prone synthesis catalyzed by pol η when replicating 8-oxo-G. Molecular modeling studies demonstrate the existence of a hydrophobic pocket in pol η that participates in the increased utilization of certain hydrophobic nucleotides. A model is proposed for enhanced pro-mutagenic replication catalyzed by pol η that couples efficient incorporation of damaged nucleotides opposite oxidized DNA lesions created by reactive oxygen species. The biological implications of this model toward increasing mutagenic events in lung cancer are discussed. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Reentrant topological phase transition in a bridging model between Kitaev and Haldane chains

NASA Astrophysics Data System (ADS)

Sugimoto, Takanori; Ohtsu, Mitsuyoshi; Tohyama, Takami

2017-12-01

We present a reentrant phase transition in a bridging model between two different topological models: Kitaev and Haldane chains. This model is activated by introducing a bond alternation into the Kitaev chain [A. Y. Kitaev, Phys. Usp. 44, 131 (2001), 10.1070/1063-7869/44/10S/S29]. Without the bond alternation, the finite pairing potential induces a topological state defined by the zero-energy Majorana edge mode, while finite bond alternation without the pairing potential makes a different topological state similar to the Haldane state, which is defined by the local Berry phase in the bulk. The topologically ordered state corresponds to the Su-Schrieffer-Heeger state, which is classified as the same symmetry class. We thus find a phase transition between the two topological phases with a reentrant phenomenon, and extend the phase diagram in the plane of the pairing potential and the bond alternation by using three techniques: recursive equation, fidelity, and Pfaffian. In addition, we find that the phase transition is characterized by both the change of the position of Majorana zero-energy modes from one edge to the other edge and the emergence of a string order in the bulk, and that the reentrance is based on a sublattice U(1) rotation. Consequently, our paper and model not only open a direct way to discuss the bulk and edge topologies but demonstrate an example of the reentrant topologies.

Using an Android application to assess registration strategies in open hepatic procedures: a planning and simulation tool

NASA Astrophysics Data System (ADS)

Doss, Derek J.; Heiselman, Jon S.; Collins, Jarrod A.; Weis, Jared A.; Clements, Logan W.; Geevarghese, Sunil K.; Miga, Michael I.

2017-03-01

Sparse surface digitization with an optically tracked stylus for use in an organ surface-based image-to-physical registration is an established approach for image-guided open liver surgery procedures. However, variability in sparse data collections during open hepatic procedures can produce disparity in registration alignments. In part, this variability arises from inconsistencies with the patterns and fidelity of collected intraoperative data. The liver lacks distinct landmarks and experiences considerable soft tissue deformation. Furthermore, data coverage of the organ is often incomplete or unevenly distributed. While more robust feature-based registration methodologies have been developed for image-guided liver surgery, it is still unclear how variation in sparse intraoperative data affects registration. In this work, we have developed an application to allow surgeons to study the performance of surface digitization patterns on registration. Given the intrinsic nature of soft-tissue, we incorporate realistic organ deformation when assessing fidelity of a rigid registration methodology. We report the construction of our application and preliminary registration results using four participants. Our preliminary results indicate that registration quality improves as users acquire more experience selecting patterns of sparse intraoperative surface data.

40 CFR 264.147 - Liability requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... pursuant to a draft by the trustee of the standby trust will be deposited by the issuing institution into... operator may meet the requirements of this section by obtaining a trust fund for liability coverage as... bond, and trust fund, except that the owner or operator may not combine a financial test covering part...

Electronic theoretical study of the influences of O adsorption on the electronic structure and optical properties of graphene

NASA Astrophysics Data System (ADS)

Shuang, Zhou; Guili, Liu; Dazhi, Fan

2017-02-01

The electronic structure and optical properties of adsorbing O atoms on graphene with different O coverage are researched using the density functional theory based upon the first-principle study to obtain further insight into properties of graphene. The adsorption energies, band structures, the density of states, light absorption coefficient and reflectivity of each system are calculated theoretically after optimizing structures of each system with different O coverage. Our calculations show that adsorption of O atoms on graphene increases the bond length of C-C which adjacent to the O atoms. When the O coverage is 9.4%, the adsorption energy (3.91 eV) is the maximum, which only increases about 1.6% higher than that of 3.1% O coverage. We find that adsorbed O atoms on pristine graphene opens up indirect gap of about 0.493-0.952 eV. Adsorbing O atoms make pristine graphene from metal into a semiconductor. When the O coverage is 9.4%, the band gap (0.952 eV) is the maximum. Comparing with pristine graphene, we find the density of states at Fermi level of O atoms adsorbing on graphene with different coverage are significantly increased. We also find that light absorption coefficient and reflectivity peaks are significantly reduced, and the larger the coverage, the smaller the absorption coefficient and reflectivity peaks are. And the blue shift phenomenon appears.

Water Adsorption on Clean and Defective Anatase TiO2 (001) Nanotube Surfaces: A Surface Science Approach.

PubMed

Kenmoe, Stephane; Lisovski, Oleg; Piskunov, Sergei; Bocharov, Dmitry; Zhukovskii, Yuri F; Spohr, Eckhard

2018-05-31

We use ab initio molecular dynamics simulations to study the adsorption of thin water films with 1 and 2 ML coverage on anatase TiO 2 (001) nanotubes. The nanotubes are modeled as 2D slabs, which consist of partially constrained and partially relaxed structural motifs from nanotubes. The effect of anion doping on the adsorption is investigated by substituting O atoms with N and S impurities on the nanotube slab surface. Due to strain-induced curvature effects, water adsorbs molecularly on defect-free surfaces via weak bonds on Ti sites and H bonds to surface oxygens. While the introduction of an S atom weakens the interaction of the surface with water, which adsorbs molecularly, the presence of an N impurity renders the surface more reactive to water, with a proton transfer from the water film and the formation of an NH group at the N site. At 2 ML coverage, a further surface-assisted proton transfer takes place in the water film, resulting in the formation of an OH - group and an NH 2 + cationic site on the surface.

Sodium-induced ordering of the benzoate species on Si(100)-2×1: a combined HREELS, XPS and NEXAFS study

NASA Astrophysics Data System (ADS)

Bitzer, T.; Richardson, N. V.; Reiss, S.; Wühn, M.; Wöll, Ch.

2000-06-01

The structure of benzoate on Na/Si(100)-2×1 has been studied by high resolution electron energy loss spectroscopy, X-ray photoelectron spectroscopy and near edge X-ray adsorption fine structure spectroscopy. At room temperature, benzoic acid (C 6H 5COOH) chemisorbs on Na/Si(100)-2×1 through a cleavage of the OH bond in the carboxylic group. The benzoate molecules formed are bonded exclusively to the sodium atoms in a bidentate coordination, in which the oxygen atoms are equivalent. At room temperature, benzoate saturation on Na/Si(100)-2×1 is reached at a coverage of one benzoate species for each Na atom or silicon dimer. At this coverage, the molecules are tilted in polar direction by 62°±4° to the surface plane and azimuthally rotated by 41°±4° with respect to the [01 1] surface azimuth. We propose an adsorbate structure, in which the benzoate molecules are oriented parallel to each other in densely packed rows.

Therapeutic alliance in dietetic practice for weight loss: Insights from health coaching.

PubMed

Nagy, Annaliese; McMahon, Anne; Tapsell, Linda; Deane, Frank; Arenson, Danielle

2018-02-13

The psychological construct of 'therapeutic alliance' can be used to better understand the effectiveness of consultations, particularly goal setting for weight management. We analysed audio-recorded health coaching sessions during a weight loss trial to explore relationships between therapeutic alliance and various contextual factors. Audio recordings of 50 health coaching sessions were analysed. After assessing fidelity to the protocol, therapeutic alliance was measured using an adapted Working Alliance Inventory Observer-rated Short Version (WAI-O-S), and examined by (i) identifying relationships between contextual factors and WAI-O-S scores (Spearman's coefficients); (ii) testing the impact of preparatory exercises and body mass index on WAI-O-S scores (one-way analysis of variance and least-squared differences tests) and (iii) comparing differences in WAI-O-S scores based on relationship status, gender and follow-up session completion (independent samples t-tests). Fidelity was high (mean 88%). WAI-O-S total scores ranged from 55 to 70 (out of 84). Session duration was significantly correlated with WAI-O-S component of 'Bond' (r = 0.42, P = 0.002). Those who completed preparatory exercises had significantly higher total WAI-O-S scores, 'Goal' and 'Task' scores. Participants who completed the follow-up session scored significantly higher for 'Goal' compared to no follow-up. Spending more time in a session appears related to increased bonding, a key component of therapeutic alliance. Preparatory work may help build therapeutic alliance and agreement on goals appears to influence follow-up completion. These exploratory findings provide directions for research addressing the professional relationship in dietetic consultations for weight loss. © 2018 Dietitians Association of Australia.

Social pairing and female mating fidelity predicted by restriction fragment length polymorphism similarity at the major histocompatibility complex in a songbird.

PubMed

Freeman-Gallant, Corey R; Meguerdichian, Michael; Wheelwright, Nathaniel T; Sollecito, Suzanne V

2003-11-01

Female birds often copulate outside the pair-bond to produce broods of mixed paternity, but despite much recent attention the adaptive significance of this behaviour remains elusive. Although several studies support the idea that extra-pair copulations (EPCs) allow females to obtain 'good genes' for their offspring, many others have found no relationship between female mating fidelity and traits likely to reflect male quality. A corollary to the good genes hypothesis proposes that females do use EPCs to increase the quality of young, but it is the interaction between maternal and paternal genomes - and not male quality per se - that is the target of female choice. We tested this 'genetic compatibility' hypothesis in a free-living population of Savannah sparrows (Passerculus sandwichensis) by determining whether females mated nonrandomly with respect to the major histocompatibility complex (Mhc). During both the 1994 and 1995 breeding seasons, female yearlings (but not older birds) avoided pairing with Mhc-similar males (P < 0.005). The Mhc similarity between mates also predicted the occurrence of extra-pair young in first broods (P < 0.007) and covaried with estimates of genome-wide levels of similarity derived from multilocus DNA fingerprinting profiles (P = 0.007). The overall genetic similarity between adults tended to predict female mating fidelity, but with less precision than their Mhc similarity (P = 0.09). In contrast, females appeared insensitive to the size, weight or age of males, none of which explained variation in female mating fidelity. Taken together, these results are consistent with the hypothesis that females sought complementary genes for their offspring and suggest either that the benefits of heterozygosity (at the Mhc) drive female mating patterns or that the avoidance of inbreeding is an ultimate cause of social and genetic mate choice in Savannah sparrows.

A quantum mechanical study of water adsorption on the (110) surfaces of rutile SnO₂ and TiO₂: investigating the effects of intermolecular interactions using hybrid-exchange density functional theory.

PubMed

Patel, M; Sanches, F F; Mallia, G; Harrison, N M

2014-10-21

Periodic hybrid-exchange density functional theory calculations are used to explore the first layer of water at model oxide surfaces, which is an important step for understanding the photocatalytic reactions involved in solar water splitting. By comparing the structure and properties of SnO2(110) and TiO2(110) surfaces in contact with water, the effects of structural and electronic differences on the water chemistry are examined. The dissociative adsorption mode at low coverage (1/7 ML) up to monolayer coverage (1 ML) on both SnO2 and TiO2(110) surfaces is analysed. To investigate further the intermolecular interactions between adjacent adsorbates, monolayer adsorption on each surface is explored in terms of binding energies and bond lengths. Analysis of the water adsorption geometry and energetics shows that the relative stability of water adsorption on SnO2(110) is governed largely by the strength of the chemisorption and hydrogen bonds at the surface of the adsorbate-substrate system. However on TiO2(110), a more complicated scenario of the first layer of water on its surface arises in which there is an interplay between chemisorption, hydrogen bonding and adsorbate-induced atomic displacements in the surface. Furthermore the projected density of states of each surface in contact with a mixture of adsorbed water molecules and adsorbed hydroxyls is presented and sheds some light on the nature of the crystalline chemical bonds as well as on why adsorbed water has often been reported to be unstable on rutile SnO2(110).

Synergistic cooperation of PDI family members in peroxiredoxin 4-driven oxidative protein folding.

PubMed

Sato, Yoshimi; Kojima, Rieko; Okumura, Masaki; Hagiwara, Masatoshi; Masui, Shoji; Maegawa, Ken-ichi; Saiki, Masatoshi; Horibe, Tomohisa; Suzuki, Mamoru; Inaba, Kenji

2013-01-01

The mammalian endoplasmic reticulum (ER) harbors disulfide bond-generating enzymes, including Ero1α and peroxiredoxin 4 (Prx4), and nearly 20 members of the protein disulfide isomerase family (PDIs), which together constitute a suitable environment for oxidative protein folding. Here, we clarified the Prx4 preferential recognition of two PDI family proteins, P5 and ERp46, and the mode of interaction between Prx4 and P5 thioredoxin domain. Detailed analyses of oxidative folding catalyzed by the reconstituted Prx4-PDIs pathways demonstrated that, while P5 and ERp46 are dedicated to rapid, but promiscuous, disulfide introduction, PDI is an efficient proofreader of non-native disulfides. Remarkably, the Prx4-dependent formation of native disulfide bonds was accelerated when PDI was combined with ERp46 or P5, suggesting that PDIs work synergistically to increase the rate and fidelity of oxidative protein folding. Thus, the mammalian ER seems to contain highly systematized oxidative networks for the efficient production of large quantities of secretory proteins.

Market-implied spread for earthquake CAT bonds: financial implications of engineering decisions.

PubMed

Damnjanovic, Ivan; Aslan, Zafer; Mander, John

2010-12-01

In the event of natural and man-made disasters, owners of large-scale infrastructure facilities (assets) need contingency plans to effectively restore the operations within the acceptable timescales. Traditionally, the insurance sector provides the coverage against potential losses. However, there are many problems associated with this traditional approach to risk transfer including counterparty risk and litigation. Recently, a number of innovative risk mitigation methods, termed alternative risk transfer (ART) methods, have been introduced to address these problems. One of the most important ART methods is catastrophe (CAT) bonds. The objective of this article is to develop an integrative model that links engineering design parameters with financial indicators including spread and bond rating. The developed framework is based on a four-step structural loss model and transformed survival model to determine expected excess returns. We illustrate the framework for a seismically designed bridge using two unique CAT bond contracts. The results show a nonlinear relationship between engineering design parameters and market-implied spread. © 2010 Society for Risk Analysis.

A density functional theory for association of fluid molecules with a functionalized surface: fluid-wall single and double bonding.

PubMed

Haghmoradi, Amin; Wang, Le; Chapman, Walter G

2017-02-01

In this manuscript we extend Wertheim's two-density formalism beyond its first order to model a system of fluid molecules with a single association site close to a planar hard wall with association sites on its surface in a density functional theory framework. The association sites of the fluid molecules are small enough that they can form only one bond, while the wall association sites are large enough to bond with more than one fluid molecule. The effects of temperature and of bulk fluid and wall site densities on the fluid density profile, extent of association, and competition between single and double bonding of fluid segments at the wall sites versus distance from the wall are presented. The theory predictions are compared with new Monte Carlo simulation results and they are in good agreement. The theory captures the surface coverage over wide ranges of temperature and bulk density by introducing the effect of steric hindrance in fluid association at a wall site.

Film growth kinetics and electric field patterning during electrospray deposition of block copolymer thin films

NASA Astrophysics Data System (ADS)

Toth, Kristof; Hu, Hanqiong; Choo, Youngwoo; Loewenberg, Michael; Osuji, Chinedum

The delivery of sub-micron droplets of dilute polymer solutions to a heated substrate by electrospray deposition (ESD) enables precisely controlled and continuous growth of block copolymer (BCP) thin films. Here we explore patterned deposition of BCP films by spatially varying the electric field at the substrate using an underlying charged grid, as well as film growth kinetics. Numerical analysis was performed to examine pattern fidelity by considering the trajectories of charged droplets during flight through imposed periodic field variations in the vicinity of the substrate. Our work uncovered an unexpected modality for improving the resolution of the patterning process via stronger field focusing through the use of a second oppositely charged grid beneath a primary focusing array, with an increase in highly localized droplet deposition on the intersecting nodes of the grid. Substrate coverage kinetics are considered for homopolymer deposition in the context of simple kinetic models incorporating temperature and molecular weight dependence of diffusivity. By contrast, film coverage kinetics for block copolymer depositions are additionally convoluted with preferential wetting and thickness-periodicity commensurability effects. NSF GRFP.

Dynamic Assessment of the Endothelialization of Tissue-Engineered Blood Vessels Using an Optical Coherence Tomography Catheter-Based Fluorescence Imaging System

PubMed Central

Gurjarpadhye, Abhijit Achyut; DeWitt, Matthew R.; Xu, Yong; Wang, Ge; Rylander, Marissa Nichole

2015-01-01

Background: Lumen endothelialization of bioengineered vascular scaffolds is essential to maintain small-diameter graft patency and prevent thrombosis postimplantation. Unfortunately, nondestructive imaging methods to visualize this dynamic process are lacking, thus slowing development and clinical translation of these potential tissue-engineering approaches. To meet this need, a fluorescence imaging system utilizing a commercial optical coherence tomography (OCT) catheter was designed to visualize graft endothelialization. Methods: C7 DragonFly™ intravascular OCT catheter was used as a channel for delivery and collection of excitation and emission spectra. Poly-dl-lactide (PDLLA) electrospun scaffolds were seeded with endothelial cells (ECs). Seeded cells were exposed to Calcein AM before imaging, causing the living cells to emit green fluorescence in response to blue laser. By positioning the catheter tip precisely over a specimen using high-fidelity electromechanical components, small regions of the specimen were excited selectively. The resulting fluorescence intensities were mapped on a two-dimensional digital grid to generate spatial distribution of fluorophores at single-cell-level resolution. Fluorescence imaging of endothelialization on glass and PDLLA scaffolds was performed using the OCT catheter-based imaging system as well as with a commercial fluorescence microscope. Cell coverage area was calculated for both image sets for quantitative comparison of imaging techniques. Tubular PDLLA scaffolds were maintained in a bioreactor on seeding with ECs, and endothelialization was monitored over 5 days using the OCT catheter-based imaging system. Results: No significant difference was observed in images obtained using our imaging system to those acquired with the fluorescence microscope. Cell area coverage calculated using the images yielded similar values. Nondestructive imaging of endothelialization on tubular scaffolds showed cell proliferation with cell coverage area increasing from 15±4% to 89±6% over 5 days. Conclusion: In this study, we showed the capability of an OCT catheter-based imaging system to obtain single-cell resolution and to quantify endothelialization in tubular electrospun scaffolds. We also compared the resulting images with traditional microscopy, showing high fidelity in image capability. This imaging system, used in conjunction with OCT, could potentially be a powerful tool for in vitro optimization of scaffold cellularization, ensuring long-term graft patency postimplantation. PMID:25539889

Modified pulse laser deposition of Ag nanostructure as intermediate for low temperature Cu-Cu bonding

NASA Astrophysics Data System (ADS)

Liu, Ziyu; Cai, Jian; Wang, Qian; Liu, Lei; Zou, Guisheng

2018-07-01

To lower the Cu-Cu bonding temperature and save the time of the bonding process applied for 3D integration, the Ag nanostructure deposited by pulsed laser deposition (PLD) was designed and decorated on the Cu pads as intermediate. Influences of different PLD process parameters on the designed Ag nanostructure morphology were investigated in this work. The large nanoparticles (NP) defects, NPs coverage rate on the Cu pad, and NPs size distribution were adopted to evaluate the PLD parameters based on the NPs morphology observation and the Cu-Cu bonding quality. The medium laser power of 0.8 W, smaller distance between target and substrate, and protective container should be applied in the optimized PLD to obtain the Ag nanostructure. Then a loose 3D mesh Ag nanostructure consisted of the protrusions and grooves was formed and the morphology observation proved the nanostructure deposition mechanism was contributed to the block of nano-film nucleation and nanoparticles absorption. Finally, the relationship between the bonding temperature and pressure suitable for the Ag nanostructure had been determined based on shear strength and interface observation. The results revealed the combination of higher bonding temperature (250 °C) and lower pressure (20 MPa), or lower bonding temperature (180 °C) and higher pressure (50 MPa) can both achieve the bonding process with the short bonding time of 5 min and annealing at 200 °C for 25 min in vacuum furnace.

NDE of Fiber Reinforced Foam Composite Structures for Future Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Walker, james; Roth, Don; Hopkins, Dale

2010-01-01

This slide presentation reviews the complexities of non-destructive evaluation (NDE) of fiber reinforced foam composite structures to be used for aerospace vehicles in the future.Various views of fiber reinforced foam materials are shown and described. Conventional methods of NDE for composites are reviewed such as Micro-computed X-Ray Tomography, Thermography, Shearography, and Phased Array Ultrasonics (PAUT). These meth0ods appear to work well on the face sheet and face sheet ot core bond, they do not provide adequate coverage for the webs. There is a need for additional methods that will examine the webs and web to foam core bond.

Water adsorption on the Fe3O4(111) surface: dissociation and network formation.

PubMed

Zaki, Eman; Mirabella, Francesca; Ivars-Barceló, Francisco; Seifert, Jan; Carey, Spencer; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Li, Xiaoke; Paier, Joachim; Sauer, Joachim

2018-06-13

We monitored adsorption of water on a well-defined Fe3O4(111) film surface at different temperatures as a function of coverage using infrared reflection-absorption spectroscopy, temperature programmed desorption, and single crystal adsorption calorimetry. Additionally, density functional theory was employed using a Fe3O4(111)-(2 × 2) slab model to generate 15 energy minimum structures for various coverages. Corresponding vibrational properties of the adsorbed water species were also computed. The results show that water molecules readily dissociate on regular surface Fetet1-O ion pairs to form "monomers", i.e., terminal Fe-OH and surface OH groups. Further water molecules adsorb on the hydroxyl covered surface non-dissociatively and form "dimers" and larger oligomers, which ultimately assemble into an ordered (2 × 2) hydrogen-bonded network structure with increasing coverage prior to the formation of a solid water film.

Structural requirements and reaction pathways in dimethyl ether combustion catalyzed by supported Pt clusters.

PubMed

Ishikawa, Akio; Neurock, Matthew; Iglesia, Enrique

2007-10-31

The identity and reversibility of the elementary steps required for catalytic combustion of dimethyl ether (DME) on Pt clusters were determined by combining isotopic and kinetic analyses with density functional theory estimates of reaction energies and activation barriers to probe the lowest energy paths. Reaction rates are limited by C-H bond activation in DME molecules adsorbed on surfaces of Pt clusters containing chemisorbed oxygen atoms at near-saturation coverages. Reaction energies and activation barriers for C-H bond activation in DME to form methoxymethyl and hydroxyl surface intermediates show that this step is more favorable than the activation of C-O bonds to form two methoxides, consistent with measured rates and kinetic isotope effects. This kinetic preference is driven by the greater stability of the CH3OCH2* and OH* intermediates relative to chemisorbed methoxides. Experimental activation barriers on Pt clusters agree with density functional theory (DFT)-derived barriers on oxygen-covered Pt(111). Measured DME turnover rates increased with increasing DME pressure, but decreased as the O2 pressure increased, because vacancies (*) on Pt surfaces nearly saturated with chemisorbed oxygen are required for DME chemisorption. DFT calculations show that although these surface vacancies are required, higher oxygen coverages lead to lower C-H activation barriers, because the basicity of oxygen adatoms increases with coverage and they become more effective in hydrogen abstraction from DME. Water inhibits reaction rates via quasi-equilibrated adsorption on vacancy sites, consistent with DFT results indicating that water binds more strongly than DME on vacancies. These conclusions are consistent with the measured kinetic response of combustion rates to DME, O2, and H2O, with H/D kinetic isotope effects, and with the absence of isotopic scrambling in reactants containing isotopic mixtures of 18O2-16O2 or 12CH3O12CH3-13CH3O13CH3. Turnover rates increased with Pt cluster size, because small clusters, with more coordinatively unsaturated surface atoms, bind oxygen atoms more strongly than larger clusters and exhibit lower steady-state vacancy concentrations and a consequently smaller number of adsorbed DME intermediates involved in kinetically relevant steps. These effects of cluster size and metal-oxygen bond energies on reactivity are ubiquitous in oxidation reactions requiring vacancies on surfaces nearly saturated with intermediates derived from O2.

Effect of pH on the Misincorporation Rate of DNA Polymerase η.

PubMed

Nishimoto, Naomi; Suzuki, Motoshi; Izuta, Shunji

2016-01-01

The many known eukaryotic DNA polymerases are classified into four families; A, B, X, and Y. Among them, DNA polymerase η, a Y family polymerase, is a low fidelity enzyme that contributes to translesional synthesis and somatic hypermutation. Although a high mutation frequency is observed in immunoglobulin genes, translesional synthesis occurs with a high accuracy. We determined whether the misincorporation rate of DNA polymerase η varies with ambient conditions. It has been reported that DNA polymerase η is unable to exclude water molecules from the active site. This finding suggests that some ions affect hydrogen bond formation at the active site. We focused on the effect of pH and evaluated the misincorporation rate of deoxyguanosine triphosphate (dGTP) opposite template T by DNA polymerase η at various pH levels with a synthetic template-primer. The misincorporation rate of dGTP by DNA polymerase η drastically increased at pH 8.0-9.0 compared with that at pH 6.5-7.5. Kinetic analysis revealed that the Km value for dGTP on the misincorporation opposite template T was markedly affected by pH. However, this drastic change was not seen with the low fidelity DNA polymerase α.

Microwave-assisted acid and base hydrolysis of intact proteins containing disulfide bonds for protein sequence analysis by mass spectrometry.

PubMed

Reiz, Bela; Li, Liang

2010-09-01

Controlled hydrolysis of proteins to generate peptide ladders combined with mass spectrometric analysis of the resultant peptides can be used for protein sequencing. In this paper, two methods of improving the microwave-assisted protein hydrolysis process are described to enable rapid sequencing of proteins containing disulfide bonds and increase sequence coverage, respectively. It was demonstrated that proteins containing disulfide bonds could be sequenced by MS analysis by first performing hydrolysis for less than 2 min, followed by 1 h of reduction to release the peptides originally linked by disulfide bonds. It was shown that a strong base could be used as a catalyst for microwave-assisted protein hydrolysis, producing complementary sequence information to that generated by microwave-assisted acid hydrolysis. However, using either acid or base hydrolysis, amide bond breakages in small regions of the polypeptide chains of the model proteins (e.g., cytochrome c and lysozyme) were not detected. Dynamic light scattering measurement of the proteins solubilized in an acid or base indicated that protein-protein interaction or aggregation was not the cause of the failure to hydrolyze certain amide bonds. It was speculated that there were some unknown local structures that might play a role in preventing an acid or base from reacting with the peptide bonds therein. 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

Morphological effects of MMPs inhibitors on the dentin bonding

PubMed Central

Li, He; Li, Tianbo; Li, Xiuying; Zhang, Zhimin; Li, Penglian; Li, Zhenling

2015-01-01

Matrix metalloproteinases (MMPs) have been studied extensively, and MMP inhibitors have been used as dental pretreatment agents prior to dentin bonding because they reduce collagen fiber degradation and improve bonding strength. However, morphologic characteristics of the collagen network after etching and of the post-adhesive dentin hybrid layers (DHL) after MMP inhibitors pretreatment have not been evaluated. Thus, we investigated demineralized dentin pretreated with chlorhexidine (CHX) and minocycline (MI) in an etch- and -rinse adhesive system with field emission scanning electron microscopy (FESEM) and immuno-gold labeling markers to observe the collagen network and DHL. FESEM revealed after CHX and MI, a demineralized dentin surface and improved collagen network formation, reduced collagen degradation, and distinct gold-labeling signals. Applying adhesive after either MMP inhibitor created a better dentin interface as evidenced by immuno-gold staining, better adhesive penetration, and higher DHL quality. With microtensile bond strength tests (µTBS) we estimated bonding strength using µTBS data. Immediate µTBS was enhanced with MMP inhibitor application to the bonding surface, and the CHX group was significantly different than non-treated etched surfaces, but no significant change was detected in the MI group. Surface micromorphology of the fractured dentin resin restoration showed that the CHX group had a better resin and dentin tube combination. Both MMP inhibitors created uniform resin coverage. Thus, morphologic results and µTBS data suggest that CHX and MI can inhibit MMP activity, improve immediate bonding strength, and enhance dentin bonding stability with an etch- and -rinse adhesive system. PMID:26379873

Laser Ablation Surface Preparation of Ti-6A1-4V for Adhesive Bonding

NASA Technical Reports Server (NTRS)

Palmieri, Frank L.; Watson, Kent A.; Morales, Guillermo; Williams, Thomas; Hicks, Robert; Wohl, Christopher J.; Hopkins, John W.; Connell, John W.

2012-01-01

Adhesive bonding offers many advantages over mechanical fastening, but requires certification before it can be incorporated in primary structures for commercial aviation without disbond-arrestment features or redundant load paths. Surface preparation is widely recognized as the key step to producing robust and predictable bonds. Laser ablation imparts both topographical and chemical changes to a surface which can lead to increased bond durability. A laser based process provides an alternative to chemical-dip, manual abrasion and grit blast treatments which are expensive, hazardous, polluting, and less precise. This report documents preliminary testing of a surface preparation technique using laser ablation as a replacement for the chemical etch and abrasive processes currently applied to Ti-6Al-4V alloy adherends. Failure mode, surface roughness, and chemical makeup were analyzed using fluorescence enhanced visualization, microscopy, and X-ray photoelectron spectroscopy, respectively. Single lap shear tests were conducted on bonded and aged specimens to observe bond strength retention and failure mode. Some promising results showed increasing strength and durability of lap shear specimens as laser ablation coverage area and beam intensity increased. Chemical analyses showed trends for surface chemical species which correlated with improved bond strength and durability. Combined, these results suggest that laser ablation is a viable process for inclusion with or/and replacement of one or more currently used titanium surface treatments. On-going work will focus on additional mechanical tests to further demonstrate improved bond durability.

Direct bonded HOPG - Analyzer support without background source

NASA Astrophysics Data System (ADS)

Groitl, Felix; Kitaura, Hidetoshi; Nishiki, Naomi; Rønnow, Henrik M.

2018-04-01

A new production process allows a direct bonding of HOPG crystals on Si wafers. This new method facilitates the production of analyzer crystals with support structure without the use of additional, background inducing fixation material, e.g. glue, wax and screws. This new method is especially interesting for the upcoming generation of CAMEA-type multiplexing spectrometers. These instruments allow for a drastic performance increase due to the increased angular coverage and multiple energy analysis. Exploiting the transparency of multiple HOPG for cold neutrons, a consecutive arrangement of HOPG analyzer crystals per Q-channel can be achieved. This implies that neutrons travel through up to 10 arrays of analyzer crystals before reaching the analyzer corresponding to their energy. Hence, a careful choice of the fixation method for the analyzer crystals in regards to transparency and background is necessary. Here, we present first results on the diffraction and mechanical performance of direct bonded analyzer crystals.

Kriging and local polynomial methods for blending satellite-derived and gauge precipitation estimates to support hydrologic early warning systems

USGS Publications Warehouse

Verdin, Andrew; Funk, Christopher C.; Rajagopalan, Balaji; Kleiber, William

2016-01-01

Robust estimates of precipitation in space and time are important for efficient natural resource management and for mitigating natural hazards. This is particularly true in regions with developing infrastructure and regions that are frequently exposed to extreme events. Gauge observations of rainfall are sparse but capture the precipitation process with high fidelity. Due to its high resolution and complete spatial coverage, satellite-derived rainfall data are an attractive alternative in data-sparse regions and are often used to support hydrometeorological early warning systems. Satellite-derived precipitation data, however, tend to underrepresent extreme precipitation events. Thus, it is often desirable to blend spatially extensive satellite-derived rainfall estimates with high-fidelity rain gauge observations to obtain more accurate precipitation estimates. In this research, we use two different methods, namely, ordinary kriging and κ-nearest neighbor local polynomials, to blend rain gauge observations with the Climate Hazards Group Infrared Precipitation satellite-derived precipitation estimates in data-sparse Central America and Colombia. The utility of these methods in producing blended precipitation estimates at pentadal (five-day) and monthly time scales is demonstrated. We find that these blending methods significantly improve the satellite-derived estimates and are competitive in their ability to capture extreme precipitation.

Determination of a Screening Metric for High Diversity DNA Libraries.

PubMed

Guido, Nicholas J; Handerson, Steven; Joseph, Elaine M; Leake, Devin; Kung, Li A

2016-01-01

The fields of antibody engineering, enzyme optimization and pathway construction rely increasingly on screening complex variant DNA libraries. These highly diverse libraries allow researchers to sample a maximized sequence space; and therefore, more rapidly identify proteins with significantly improved activity. The current state of the art in synthetic biology allows for libraries with billions of variants, pushing the limits of researchers' ability to qualify libraries for screening by measuring the traditional quality metrics of fidelity and diversity of variants. Instead, when screening variant libraries, researchers typically use a generic, and often insufficient, oversampling rate based on a common rule-of-thumb. We have developed methods to calculate a library-specific oversampling metric, based on fidelity, diversity, and representation of variants, which informs researchers, prior to screening the library, of the amount of oversampling required to ensure that the desired fraction of variant molecules will be sampled. To derive this oversampling metric, we developed a novel alignment tool to efficiently measure frequency counts of individual nucleotide variant positions using next-generation sequencing data. Next, we apply a method based on the "coupon collector" probability theory to construct a curve of upper bound estimates of the sampling size required for any desired variant coverage. The calculated oversampling metric will guide researchers to maximize their efficiency in using highly variant libraries.

Nursing challenges for universal health coverage: a systematic review1

PubMed Central

Schveitzer, Mariana Cabral; Zoboli, Elma Lourdes Campos Pavone; Vieira, Margarida Maria da Silva

2016-01-01

Objectives to identify nursing challenges for universal health coverage, based on the findings of a systematic review focused on the health workforce' understanding of the role of humanization practices in Primary Health Care. Method systematic review and meta-synthesis, from the following information sources: PubMed, CINAHL, Scielo, Web of Science, PsycInfo, SCOPUS, DEDALUS and Proquest, using the keyword Primary Health Care associated, separately, with the following keywords: humanization of assistance, holistic care/health, patient centred care, user embracement, personal autonomy, holism, attitude of health personnel. Results thirty studies between 1999-2011. Primary Health Care work processes are complex and present difficulties for conducting integrative care, especially for nursing, but humanizing practices have showed an important role towards the development of positive work environments, quality of care and people-centered care by promoting access and universal health coverage. Conclusions nursing challenges for universal health coverage are related to education and training, to better working conditions and clear definition of nursing role in primary health care. It is necessary to overcome difficulties such as fragmented concepts of health and care and invest in multidisciplinary teamwork, community empowerment, professional-patient bond, user embracement, soft technologies, to promote quality of life, holistic care and universal health coverage. PMID:27143536

The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data

NASA Technical Reports Server (NTRS)

Pearl, J. C.; Conrath, B. J.; Hanel, R. A.; Pirraglia, J. A.; Coustenis, A.

1990-01-01

The albedo, T(eff), and energy balance of Uranus are presently derived from Voyager IR Spectrometer and Radiometer data. By obtaining the absolute phase curve of Uranus, it has become possible to evaluate the Bond albedo without making separate determinations of the geometric albedo and phase integral. An orbital mean value for the bolometric Bond albedo of 0.3 + or - 0.049 yields an equilibrium temperature of 58.2 + or - 1.0 K. Thermal spectra from pole-to-pole latitude coverage establish a T(eff) of 59.1 + or - 0.3 K, leading to an energy balance of 1.06 + or - 0.08 for Uranus.

Coronal Heating and the Need for High-Resolution Observations

NASA Technical Reports Server (NTRS)

Klimchuk, James A.

2008-01-01

Despite excellent progress in recent years in understanding coronal heating, there remain many crucial questions that are still unanswered. Limitations in the observations are one important reason. Both theoretical and observational considerations point to the importance of small spatial scales, impulsive energy release, strong dynamics, and extreme plasma nonuniformity. As a consequence, high spatial resolution, broad temperature coverage, high temperature fidelity, and sensitivity to velocities and densities are all critical observational parameters. Current instruments lack one or more of these properties, and this has led to considerable ambiguity and confusion. In this talk, I will discuss recent ideas about coronal heating and emphasize that high spatial resolution observations, especially spectroscopic observations, are needed to make major progress on this important problem.

Charge transfer photodissociation of phenol on Ag(111)

NASA Astrophysics Data System (ADS)

Lee, Junseok; Ryu, Sunmin; Ku, Jong Seok; Kim, Seong Keun

2001-12-01

The photochemistry of phenol on Ag(111) has been investigated by post-irradiation temperature programmed desorption (TPD). Ultraviolet (UV) irradiation at 355 and 266 nm was found to affect only the chemisorption layer in direct contact with the metal surface, while leaving the multilayer virtually intact. The main photoinduced reaction was found to be photodissociation of the O-H bond of phenol. Two new peaks were observed at the mass of phenol in the post-irradiation TPD spectrum at 335 K and 455 K. These peaks were assigned to the recombinative desorption of phenoxy with the hydrogen from O-H bond photodissociation and from thermal C-H bond fission, respectively. The photodissociation cross section was measured at different wavelengths and coverages. A charge transfer type photodissociation mechanism was proposed, where hot electrons generated in the substrate by UV photons attach to the affinity level of the adsorbed phenol. The transition to the transient anionic potential then leads to facile dissociation of O-H bond. The affinity level of phenol has been estimated to lie at 3.2-3.5 eV above the Fermi level for the 1 ML case.

Predicting growth of graphene nanostructures using high-fidelity atomistic simulations

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

McCarty, Keven F.; Zhou, Xiaowang; Ward, Donald K.

2015-09-01

In this project we developed t he atomistic models needed to predict how graphene grows when carbon is deposited on metal and semiconductor surfaces. We first calculated energies of many carbon configurations using first principles electronic structure calculations and then used these energies to construct an empirical bond order potentials that enable s comprehensive molecular dynamics simulation of growth. We validated our approach by comparing our predictions to experiments of graphene growth on Ir, Cu and Ge. The robustness of ou r understanding of graphene growth will enable high quality graphene to be grown on novel substrates which will expandmore » the number of potential types of graphene electronic devices.« less

Bridge-bonded formate: active intermediate or spectator species in formic acid oxidation on a Pt film electrode?

PubMed

Chen, Y-X; Heinen, M; Jusys, Z; Behm, R J

2006-12-05

We present and discuss the results of an in situ IR study on the mechanism and kinetics of formic acid oxidation on a Pt film/Si electrode, performed in an attenuated total reflection (ATR) flow cell configuration under controlled mass transport conditions, which specifically aimed at elucidating the role of the adsorbed bridge-bonded formates in this reaction. Potentiodynamic measurements show a complex interplay between formation and desorption/oxidation of COad and formate species and the total Faradaic current. The notably faster increase of the Faradaic current compared to the coverage of bridge-bonded formate in transient measurements at constant potential, but with different formic acid concentrations, reveals that adsorbed formate decomposition is not rate-limiting in the dominant reaction pathway. If being reactive intermediate at all, the contribution of formate adsorption/decomposition to the reaction current decreases with increasing formic acid concentration, accounting for at most 15% for 0.2 M DCOOH at 0.7 VRHE. The rapid build-up/removal of the formate adlayer and its similarity with acetate or (bi-)sulfate adsorption/desorption indicate that the formate adlayer coverage is dominated by a fast dynamic adsorption-desorption equilibrium with the electrolyte, and that formate desorption is much faster than its decomposition. The results corroborate the proposal of a triple pathway reaction mechanism including an indirect pathway, a formate pathway, and a dominant direct pathway, as presented previously (Chen, Y. X.; et al. Angew. Chem. Int. Ed. 2006, 45, 981), in which adsorbed formates act as a site-blocking spectator in the dominant pathway rather than as an active intermediate.

Effects of resistance form on attachment strength of resin-retained castings.

PubMed

Wilkes, P W; Shillingburg, H T; Johnson, D L

2000-01-01

This study evaluated the effects of tooth preparation design on resistance to dislodgment of a resin-bonded fixed partial denture (RBFPD). The variations of tooth preparation tested included axial coverage, retentive grooves, and an occlusal rest. Patterns of the tooth preparation designs were prepared and cast in a base metal alloy. Retainer patterns were waxed to refractory casts of metal dies, cast, finished and then bonded to the dies. The complete assemblies were loaded to failure on an Instron mechanical testing machine, and analysis indicated that retainers with occlusal rests were the most resistant. Grooves provided no statistically significant increase in resistance to failure of the cement. Increased axial coverage did not increase resistance to dislodgment. Successful fixed partial dentures (FPDs) depend on cast retainers to resist displacement of the restoration during function. Introduction of resin-bonded restorations opened the possibility of FPDs with minimal reduction of abutments. Specific questions concerning long term success and tooth preparation designs were prominent concerns. The influence of resistance form on overall stability of a restoration was also of particular interest. Buonocore established the foundation for retention of composite resins to acid-pitted enamel. Rochette used this technology to bond perforated cast metal splints to periodontally compromised teeth. A mechanical interlock was created as composite resin engaged these perforations and sustained the cast splint to acid-etched enamel. Howe adapted this design for replacement of anterior teeth by adding porcelain to a metal ceramic framework and then bonding the framework to abutments without tooth preparations. The advantages of these procedures were their conservative nature, esthetics, and ease of rebonding after dislodgment. Livaditis and Thompson adapted the procedure proposed by Tanaka of corrosion-pitting the bonding surface of a base metal alloy. They increased the surface area to be bonded, eliminated the perforations to improve rigidity of the framework, and described tooth preparation modifications of the abutments. They suggested an occlusal rest, establishment of guide planes through axial reduction, and a proximal extension to the facial surface to resist lingual displacement. Simonson, et al., based their anterior tooth preparation design on the configuration suggested by Livaditis which included a slight chamfer finish line plus reduction of the lingual surface to provide a thicker metal framework. Barrack introduced an inlay type tooth preparation for the occlusal rest plus shallow vertical proximal grooves, and Meiers used grooves as an esthetic alternative to proximal extensions. Clinical studies and surveys have identified specific variables involved with success and failure, while in vitro studies have evaluated framework designs, bonding agents, and methods for pitting the metal surface. This study evaluated resistance of RBFPDs to dislodgment of different tooth preparation designs.

Exploring the effect of oxygen coverage on the electronic, magnetic and chemical properties of Ni(111) supported h-BN sheet: A density functional study

NASA Astrophysics Data System (ADS)

Wasey, A. H. M. Abdul; Das, G. P.; Majumder, C.

2017-05-01

Traditionally, h-BN is used as coating material to prevent corrosion on the metal surface. In sharp contrast to this, here we show catalytic behavior of h-BN monolayer deposited on Ni(111) surface, clearly demonstrating the influence of the support in modulation of h-BN electronic structure. Using first principles density functional theory we have studied the interaction of O2 molecules with the h-BN/Ni(111) surface. The activation of Osbnd O bond, which is the most important step for oxidative catalysis, showed dependence on the O2 coverage. Thus this study is extremely important to predict the optimum O2 pressure in reaction chamber for efficient catalysis.

Hydrogen-bond landscapes, geometry and energetics of squaric acid and its mono- and dianions: a Cambridge Structural Database, IsoStar and computational study.

PubMed

Allen, Frank H; Cruz-Cabeza, Aurora J; Wood, Peter A; Bardwell, David A

2013-10-01

As part of a programme of work to extend central-group coverage in the Cambridge Crystallographic Data Centre's (CCDC) IsoStar knowledge base of intermolecular interactions, we have studied the hydrogen-bonding abilities of squaric acid (H2SQ) and its mono- and dianions (HSQ(-) and SQ(2-)) using the Cambridge Structural Database (CSD) along with dispersion-corrected density functional theory (DFT-D) calculations for a range of hydrogen-bonded dimers. The -OH and -C=O groups of H2SQ, HSQ(-) and SQ(2-) are potent donors and acceptors, as indicated by their hydrogen-bond geometries in available crystal structures in the CSD, and by the attractive energies calculated for their dimers with acetone and methanol, which were used as model acceptors and donors. The two anions have sufficient examples in the CSD for their addition as new central groups in IsoStar. It is also shown that charge- and resonance-assisted hydrogen bonds involving H2SQ and HSQ(-) are similar in strength to those made by carboxylate COO(-) acceptors, while hydrogen bonds made by the dianion SQ(2-) are somewhat stronger. The study reinforces the value of squaric acid and its anions as cocrystal formers and their actual and potential importance as isosteric replacements for carboxylic acid and carboxylate functions.

Using Amphiphilic Copolymers and Nanoparticles to Organize Charged Biopolymers

NASA Astrophysics Data System (ADS)

Park, Jung Hyun; McConnell, Marla; Sun, Yujie; Goldman, Yale; Composto, Russell

2009-03-01

Nanoparticles (NPs) on amphiphilic random copolymers control filamentous actin (F-actin) attachment. 3-aminopropyltriethoxysilane (APTES) coated silica NPs are selectively bonded to acrylic acid groups on the surface of a poly(styrene-r-acrylic acid) (PS-r-PAA) film. By changing the concentration of NPs in the medium, the surface density of positively charged anchors is tuned. Using total internal reflection fluorescence (TIRF) microscopy, immobilization of F-actin is observed via electrostatic interaction with NPs at high NP coverages. Below a critical coverage, F-actin is weakly attached and undergoes thermal fluctuations near the surface. Another method to tune F-actin attachment is to use APTES to cross-link and create positive charge in PAA films. Here, the surface coverage of F-actin decreases as APTES concentration increases. This observation is attributed to an increase in surface roughness and hydrophobicity that reduces the effective surface sites that attract F-actin. In addition, in-situ G-actin polymerization to F-actin is observed on both the NP and cross-linked PAA templates.

Electron solvation and localization at interfaces

NASA Astrophysics Data System (ADS)

Harris, Charles B.; Szymanski, Paul; Garrett-Roe, Sean; Miller, Andre D.; Gaffney, Kelly J.; Liu, Simon H.; Bezel, Ilya

2003-12-01

Two-photon photoemission of thiolate/Ag(111), nitrile/Ag(111), and alcohol/Ag(111) interfaces elucidates electron solvation and localization in two dimensions. For low coverages of thiolates on Ag(111), the occupied (HOMO) and unoccupied (LUMO) electronic states of the sulfer-silver bond are localized due to the lattice gas structure of the adsorbate. As the coverage saturates and the adsorbate-adsorbate nearest neighbor distance decreases, the HOMO and LUMO delocalize across many adsorbate molecules. Alcohol- and nitrile-covered Ag(111) surfaces solvate excess image potential state (IPS) electrons. In the case of alcohol-covered surfaces, this solvation is due to a shift in the local workfunction of the surface. For two-monolayer coverages of nitriles/Ag(111), localization accompanies solvation of the IPS. The size of the localized electron can be estimated by Fourier transformation of the wavefunction from momentum- to position-space. The IPS electron localizes to 15 +/- 4 angstroms full-width at half maximum in the plane of the surface, i.e., to a single lattice site.

Covalent Coupling of Nanoparticles with Low-Density Functional Ligands to Surfaces via Click Chemistry

PubMed Central

Rianasari, Ina; de Jong, Michel P.; Huskens, Jurriaan; van der Wiel, Wilfred G.

2013-01-01

We demonstrate the application of the 1,3-dipolar cycloaddition (“click” reaction) to couple gold nanoparticles (Au NPs) functionalized with low densities of functional ligands. The ligand coverage on the citrate-stabilized Au NPs was adjusted by the ligand:Au surface atom ratio, while maintaining the colloidal stability of the Au NPs in aqueous solution. A procedure was developed to determine the driving forces governing the selectivity and reactivity of citrate-stabilized and ligand-functionalized Au NPs on patterned self-assembled monolayers. We observed selective and remarkably stable chemical bonding of the Au NPs to the complimentarily functionalized substrate areas, even when estimating that only 1–2 chemical bonds are formed between the particles and the substrate. PMID:23434666

Reality TV positions heart center as cardiac care leader.

PubMed

Rees, T

2001-01-01

Saint Thomas Heart Institute, Nashville, Tenn., has a long history of successful cardiac care. More than 200,000 patients have been treated at Saint Thomas. Earlier this year the hospital launched a new branding campaign that features former patients who have bonded with the institution. These former patients were provided MiniDV video cameras to record their stories. The campaign has attracted considerable attention, including newspaper and TV news coverage.

Mutual medication in capuchin monkeys – Social anointing improves coverage of topically applied anti-parasite medicines

PubMed Central

Bowler, Mark; Messer, Emily J. E.; Claidière, Nicolas; Whiten, Andrew

2015-01-01

Wild and captive capuchin monkeys will anoint themselves with a range of strong smelling substances including millipedes, ants, limes and onions. Hypotheses for the function of the behaviour range from medicinal to social. However, capuchin monkeys may anoint in contact with other individuals, as well as individually. The function of social anointing has also been explained as either medicinal or to enhance social bonding. By manipulating the abundance of an anointing resource given to two groups of tufted capuchins, we tested predictions derived from the main hypotheses for the functions of anointing and in particular, social anointing. Monkeys engaged in individual and social anointing in similar proportions when resources were rare or common, and monkeys holding resources continued to join anointing groups, indicating that social anointing has functions beyond that of gaining access to resources. The distribution of individual and social anointing actions on the monkeys’ bodies supports a medicinal function for both individual and social anointing, that requires no additional social bonding hypotheses. Individual anointing targets hard-to-see body parts that are harder to groom, whilst social anointing targets hard-to-reach body parts. Social anointing in capuchins is a form of mutual medication that improves coverage of topically applied anti-parasite medicines. PMID:26456539

Mutual medication in capuchin monkeys - Social anointing improves coverage of topically applied anti-parasite medicines.

PubMed

Bowler, Mark; Messer, Emily J E; Claidière, Nicolas; Whiten, Andrew

2015-10-12

Wild and captive capuchin monkeys will anoint themselves with a range of strong smelling substances including millipedes, ants, limes and onions. Hypotheses for the function of the behaviour range from medicinal to social. However, capuchin monkeys may anoint in contact with other individuals, as well as individually. The function of social anointing has also been explained as either medicinal or to enhance social bonding. By manipulating the abundance of an anointing resource given to two groups of tufted capuchins, we tested predictions derived from the main hypotheses for the functions of anointing and in particular, social anointing. Monkeys engaged in individual and social anointing in similar proportions when resources were rare or common, and monkeys holding resources continued to join anointing groups, indicating that social anointing has functions beyond that of gaining access to resources. The distribution of individual and social anointing actions on the monkeys' bodies supports a medicinal function for both individual and social anointing, that requires no additional social bonding hypotheses. Individual anointing targets hard-to-see body parts that are harder to groom, whilst social anointing targets hard-to-reach body parts. Social anointing in capuchins is a form of mutual medication that improves coverage of topically applied anti-parasite medicines.

Model-Based Testability Assessment and Directed Troubleshooting of Shuttle Wiring Systems

NASA Technical Reports Server (NTRS)

Deb, Somnath; Domagala, Chuck; Shrestha, Roshan; Malepati, Venkatesh; Cavanaugh, Kevin; Patterson-Hine, Ann; Sanderfer, Dwight; Cockrell, Jim; Norvig, Peter (Technical Monitor)

2000-01-01

We have recently completed a pilot study on the Space shuttle wiring system commissioned by the Wiring Integrity Research (WIRe) team at NASA Ames Research Center, As the space shuttle ages, it is experiencing wiring degradation problems including arcing, chaffing insulation breakdown and broken conductors. A systematic and comprehensive test process is required to thoroughly test and quality assure (QA) the wiring systems. The NASA WIRe team recognized the value of a formal model based analysis for risk-assessment and fault coverage analysis. However. wiring systems are complex and involve over 50,000 wire segments. Therefore, NASA commissioned this pilot study with Qualtech Systems. Inc. (QSI) to explore means of automatically extracting high fidelity multi-signal models from wiring information database for use with QSI's Testability Engineering and Maintenance System (TEAMS) tool.

Development of a VOR/DME model for an advanced concepts simulator

NASA Technical Reports Server (NTRS)

Steinmetz, G. G.; Bowles, R. L.

1984-01-01

The report presents a definition of a VOR/DME, airborne and ground systems simulation model. This description was drafted in response to a need in the creation of an advanced concepts simulation in which flight station design for the 1980 era can be postulated and examined. The simulation model described herein provides a reasonable representation of VOR/DME station in the continental United States including area coverage by type and noise errors. The detail in which the model has been cast provides the interested researcher with a moderate fidelity level simulator tool for conducting research and evaluation of navigator algorithms. Assumptions made within the development are listed and place certain responsibilities (data bases, communication with other simulation modules, uniform round earth, etc.) upon the researcher.

78 FR 53168 - Agency Information Collection Activities: Submission to OMB for Reinstatement, Without Change, of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-28

...The NCUA intends to submit the following information collection to the Office of Management and Budget (OMB) for review and clearance under the Paperwork Reduction Act of 1995. This information collection relates to NCUA rules and regulations, which require a federal credit union (FCU) to monitor its eligibility to qualify for a higher fidelity coverage deductible and to notify the NCUA if its financial condition changes resulting in the loss of that eligibility for the higher deductible. This information collection notice is published to obtain comments from the public. This requirement enables NCUA to monitor the FCU's financial condition for safety and soundness purposes and helps to assure that FCUs are properly and adequately protected against potential losses due to insider abuse such as fraud and embezzlement.

Selective adsorption of a supramolecular structure on flat and stepped gold surfaces

NASA Astrophysics Data System (ADS)

Peköz, Rengin; Donadio, Davide

2018-04-01

Halogenated aromatic molecules assemble on surfaces forming both hydrogen and halogen bonds. Even though these systems have been intensively studied on flat metal surfaces, high-index vicinal surfaces remain challenging, as they may induce complex adsorbate structures. The adsorption of 2,6-dibromoanthraquinone (2,6-DBAQ) on flat and stepped gold surfaces is studied by means of van der Waals corrected density functional theory. Equilibrium geometries and corresponding adsorption energies are systematically investigated for various different adsorption configurations. It is shown that bridge sites and step edges are the preferred adsorption sites for single molecules on flat and stepped surfaces, respectively. The role of van der Waals interactions, halogen bonds and hydrogen bonds are explored for a monolayer coverage of 2,6-DBAQ molecules, revealing that molecular flexibility and intermolecular interactions stabilize two-dimensional networks on both flat and stepped surfaces. Our results provide a rationale for experimental observation of molecular carpeting on high-index vicinal surfaces of transition metals.

Electrochemistry-Assisted Top-Down Characterization of Disulfide-Containing Proteins

PubMed Central

Zhang, Yun; Cui, Weidong; Zhang, Hao; Dewald, Howard D.; Chen, Hao

2013-01-01

Covalent disulfide bond linkage in a protein represents an important challenge for mass spectrometry (MS)-based top-down protein structure analysis as it reduces the backbone cleavage efficiency for MS/MS dissociation. This study presents a strategy for solving this critical issue via integrating electrochemistry (EC) online with top-down MS approach. In this approach, proteins undergo electrolytic reduction in an electrochemical cell to break disulfide bonds and then online ionized into gaseous ions for analysis by electron-capture dissociation (ECD) and collision-induced dissociation (CID). The electrochemical reduction of proteins allows to remove disulfide bond constraints and also leads to increased charge numbers of the resulting protein ions. As a result, sequence coverage was significantly enhanced, as exemplified by β-lactoglobulin A (24 vs. 73 backbone cleavages before and after electrolytic reduction, respectively) and lysozyme (5 vs. 66 backbone cleavages before and after electrolytic reduction, respectively). This methodology is fast and does not need chemical reductants, which would have an important impact in high-throughput proteomics research. PMID:22448817

Electrochemistry-assisted top-down characterization of disulfide-containing proteins.

PubMed

Zhang, Yun; Cui, Weidong; Zhang, Hao; Dewald, Howard D; Chen, Hao

2012-04-17

Covalent disulfide bond linkage in a protein represents an important challenge for mass spectrometry (MS)-based top-down protein structure analysis as it reduces the backbone cleavage efficiency for MS/MS dissociation. This study presents a strategy for solving this critical issue via integrating electrochemistry (EC) online with a top-down MS approach. In this approach, proteins undergo electrolytic reduction in an electrochemical cell to break disulfide bonds and then undergo online ionization into gaseous ions for analysis by electron-capture dissociation (ECD) and collision-induced dissociation (CID). The electrochemical reduction of proteins allows one to remove disulfide bond constraints and also leads to increased charge numbers of the resulting protein ions. As a result, sequence coverage was significantly enhanced, as exemplified by β-lactoglobulin A (24 vs 75 backbone cleavages before and after electrolytic reduction, respectively) and lysozyme (5 vs 66 backbone cleavages before and after electrolytic reduction, respectively). This methodology is fast and does not need chemical reductants, which would have an important impact in high-throughput proteomics research.

First-Order Model Management With Variable-Fidelity Physics Applied to Multi-Element Airfoil Optimization

NASA Technical Reports Server (NTRS)

Alexandrov, N. M.; Nielsen, E. J.; Lewis, R. M.; Anderson, W. K.

2000-01-01

First-order approximation and model management is a methodology for a systematic use of variable-fidelity models or approximations in optimization. The intent of model management is to attain convergence to high-fidelity solutions with minimal expense in high-fidelity computations. The savings in terms of computationally intensive evaluations depends on the ability of the available lower-fidelity model or a suite of models to predict the improvement trends for the high-fidelity problem, Variable-fidelity models can be represented by data-fitting approximations, variable-resolution models. variable-convergence models. or variable physical fidelity models. The present work considers the use of variable-fidelity physics models. We demonstrate the performance of model management on an aerodynamic optimization of a multi-element airfoil designed to operate in the transonic regime. Reynolds-averaged Navier-Stokes equations represent the high-fidelity model, while the Euler equations represent the low-fidelity model. An unstructured mesh-based analysis code FUN2D evaluates functions and sensitivity derivatives for both models. Model management for the present demonstration problem yields fivefold savings in terms of high-fidelity evaluations compared to optimization done with high-fidelity computations alone.

QCM-D and ToF-SIMS Investigation to Deconvolute the Relationship between Lipid Adsorption and Orientation on Lipase Activity.

PubMed

Joyce, Paul; Kempson, Ivan; Prestidge, Clive A

2015-09-22

Quartz crystal microbalance with dissipation (QCM-D) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to provide insights into the relationship between lipid adsorption kinetics and molecular behavior in porous silica particles of varying hydrophobicities on lipase activity. Lipase (an interfacial enzyme that cleaves ester bonds to break down lipids to fatty acids and monoglycerides) activity was controlled by loading triglycerides at different surface coverages in hydrophilic and hydrophobic porous silica particles. The rate of lipid adsorption increased 2-fold for the hydrophobic surface compared to the hydrophilic surface. However, for submonolayer lipid coverage, the hydrophilic surface enhanced lipase activity 4-fold, whereas the hydrophobic surface inhibited lipase activity 16-fold, compared to lipid droplets in water. A difference in lipid orientation for low surface coverage, evidenced by ToF-SIMS, indicated that lipid adsorbs to hydrophilic silica in a conformation promoting hydrolysis. Multilayer coverage on hydrophobic and hydrophilic surfaces was indistinguishable with ToF-SIMS analysis. Increased lipid adsorption for both substrates facilitated digestion kinetics comparable to a conventional emulsion. Improved understanding of the interfacial adsorption and orientation of lipid and its digestibility in porous silica has implications in improving the uptake of pharmaceuticals and nutrients from lipid-based delivery systems.

Enhanced Ge/Si(001) island areal density and self-organization due to P predeposition

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

Cho, B.; Bareno, J.; Petrov, I.

The predeposition of P, with coverages {theta}{sub P} ranging from 0 to 1 ML, on Si(001) significantly increases both the areal density and spatial self-organization of Ge islands grown by gas-source molecular beam epitaxy from hydride precursors. The Ge island density {rho}{sub Ge} initially increases with {theta}{sub P}, reaching a maximum of 1.4 x 10{sup 10} cm{sup -2} at {theta}{sub P} = 0.7 ML, a factor of four times higher than on bare Si(001) under the same deposition conditions, before decreasing at higher P coverages. The increase in {rho}{sub Ge}({theta}{sub P}) is due to a corresponding decrease in Ge adatommore » mean free paths resulting from passivation of surface dangling bonds by adsorbed pentavalent P atoms which, in addition, leads to surface roughening and, therefore, higher Ge coverages at constant Ge{sub 2}H{sub 6} dose. As {theta}{sub P} (and hence, {rho}{sub Ge}) increases, so does the degree of Ge island ordering along <100> directions due to the anisotropic strain field surrounding individual islands. Similar results are obtained for Ge island growth on P-doped Si(001) layers where strong P surface segregation provides partial monolayer coverage prior to Ge deposition.« less

Helicity moduli of three-dimensional dilute XY models

NASA Astrophysics Data System (ADS)

Garg, Anupam; Pandit, Rahul; Solla, Sara A.; Ebner, C.

1984-07-01

The helicity moduli of various dilute, classical XY models on three-dimensional lattices are studied with a view to understanding some aspects of the superfluidity of 4He in Vycor glass. A spinwave calculation is used to obtain the low-temperature helicity modulus of a regularly-diluted XY model. A similar calculation is performed for the randomly bond-diluted and site-diluted XY models in the limit of low dilution. A Monte Carlo simulation is used to obtain the helicity modulus of the randomly bond-diluted XY model over a wide range of temperature and dilution. It is found that the randomly diluted models do agree and the regularly diluted model does not agree with certain experimentally found features of the variation in superfluid fraction with coverage of 4He in Vycor glass.

Laboratory Investigations of Mesospheric Ice Surfaces: Absence of Dangling Bonds in the Presence of Atomic Oxygen

NASA Astrophysics Data System (ADS)

Boulter, J. E.; Morgan, C. G.; Marschall, J.

2006-05-01

Remote observations of PMCs have become more sophisticated and have increased in geographic and temporal coverage, while numerical models have advanced in detail and predictive power. Together, these advances enable new questions of PMC morphology, optical properties, and microphysical processes in their formation and dissipation. Laboratory investigations also advance this understanding, simulating physical and chemical processes unique to this atmospheric region under comparable conditions. In this work, ice deposition experiments in the presence of microwave discharge-dissociated molecular oxygen suggest heterogeneous interactions between dangling OH bonds on the ice surface and atomic oxygen. Ice films deposited on a gold substrate at temperatures of 115, 130, and 140 K from oxygen/water gas mixtures representative of the summertime polar mesosphere exhibit infrared absorption features characteristic of dangling bonds, whereas films grown in the presence of atomic oxygen do not. Dangling bond spectral features are shown to diminish rapidly when the microwave discharge is activated during ice deposition. Similar decreases were not seen when the gas stream was heated or when the ice film was slowly annealed from 130 to 160 K. One interpretation of these results is that atomic oxygen binds to dangling bond sites during ice growth, a phenomenon that may also occur during the formation of ice particles observed just below the cold summertime mesopause.

Multi-fidelity stochastic collocation method for computation of statistical moments

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

Zhu, Xueyu, E-mail: xueyu-zhu@uiowa.edu; Linebarger, Erin M., E-mail: aerinline@sci.utah.edu; Xiu, Dongbin, E-mail: xiu.16@osu.edu

We present an efficient numerical algorithm to approximate the statistical moments of stochastic problems, in the presence of models with different fidelities. The method extends the multi-fidelity approximation method developed in . By combining the efficiency of low-fidelity models and the accuracy of high-fidelity models, our method exhibits fast convergence with a limited number of high-fidelity simulations. We establish an error bound of the method and present several numerical examples to demonstrate the efficiency and applicability of the multi-fidelity algorithm.

Iron phthalocyanine on Cu(111): Coverage-dependent assembly and symmetry breaking, temperature-induced homocoupling, and modification of the adsorbate-surface interaction by annealing.

PubMed

Snezhkova, Olesia; Bischoff, Felix; He, Yuanqin; Wiengarten, Alissa; Chaudhary, Shilpi; Johansson, Niclas; Schulte, Karina; Knudsen, Jan; Barth, Johannes V; Seufert, Knud; Auwärter, Willi; Schnadt, Joachim

2016-03-07

We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 °C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The symmetry breaking observed in scanning tunneling microscopy images is found to be coverage dependent and to persist upon annealing. Further, we find that annealing to temperatures between 300 and 320 °C leads to both desorption of iron phthalocyanine molecules from the surface and their agglomeration. We see clear evidence of temperature-induced homocoupling reactions of the iron phthalocyanine molecules following dehydrogenation of their isoindole rings, similar to what has been observed for related tetrapyrroles on transition metal surfaces. Finally, spectroscopy indicates a modified substrate-adsorbate interaction upon annealing with a shortened bond distance. This finding could potentially explain a changed reactivity of Cu-supported iron phthalocyanine in comparison to that of the pristine compound.

Understanding the pseudocapacitance of RuO2 from joint density functional theory

NASA Astrophysics Data System (ADS)

Zhan, Cheng; Jiang, De-en

2016-11-01

Pseudocapacitors have been experimentally studied for many years in electric energy storage. However, first principles understanding of the pseudocapacitive behavior is still not satisfactory due to the complexity involved in modeling electrochemistry. In this paper, we applied joint density functional theory (JDFT) to simulate the pseudocapacitive behavior of RuO2, a prototypical material, in a model electrolyte. We obtained from JDFT a capacitive curve which showed a redox peak position comparable to that in the experimental cyclic voltammetry (CV) curve. We found that the experimental turning point from double-layer to pseudocapacitive charge storage at low scan rates could be explained by the hydrogen adsorption at low coverage. As the electrode voltage becomes more negative, H coverage increases and causes the surface-structure change, leading to bended -OH bonds at the on-top oxygen atoms and large capacitance. This H coverage-dependent capacitance can explain the high pseudocapacitance of hydrous RuO2. Our work here provides a first principles understanding of the pseudocapacitance for RuO2 in particular and for transition-metal oxides in general.

Nature of water and hydrogen reactions on transition metal surfaces studied by scanning tunneling microscopy

NASA Astrophysics Data System (ADS)

Tatarkhanov, Mouslim Magomedovich

Scanning Tunneling Microscopy (STM) has already been established as a tool for the investigation of simple reaction mechanisms. In this work I present results of two parallel studies using STM: first, hydrogen on Ru(0001) surface and second, water on Ru(0001) and Pd(111). In both studies initial stages of adsorption up to saturation monolayer coverage were investigated by variable temperature scanning tunneling microscopy (VT STM). The first step of the hydrogen adsorption study was the identification and characterization of the various coverage structures on clean Ru(0001). Hydrogen was found to adsorb dissociatively forming ( 3x3 )R30°, 3 domains of (2x1), (2x2)-3H and (1x1) for increasing coverages of theta=0.3 ML, 0.5 ML, 0.75 ML and 0.1 ML respectively. Some of these structures were observed to coexist at intermediate coverage values. In addition effects of impurities such as oxygen and carbon on hydrogen adsorption has been discussed. Next, near saturation coverage the interesting mechanism of how H 2 dissociates and binds to the surface of Ru(0001) has been observed. We found that the H2 dissociation takes place only on Ru sites where the metal atom is not bound to any H atom. Such active sites are formed when at least 3 H-vacancies aggregate by thermal diffusion. Sites formed by single H-vacancies (i.e. unoccupied Ru sites) or pairs of adjoining vacancies were found to be unreactive toward H2. H-vacancies were observed as single entities diffusing on the surface at 50 K and able to form transient triangular shaped aggregations where H2 molecules dissociated. It was found that the diffusion and aggregation of the H-vacancies is essential in creation of active sites where dissociative adsorption of hydrogen occurs. The first step of water studies was the initial stages of growth of water on the hexagonal surfaces of Pd(111) and Ru(0001) in the temperature range between 40 K and 130 K. In addition, DFT calculations and STM image simulations were used to validate the models. Below 130 K water dissociation does not occur at any appreciable rate and only molecular films are formed. At these temperatures the kinetics of water growth leads to structures where the molecules bind to the metal substrate through the O-lone pair while making 3 H-bonds with neighboring molecules and form clusters of hexagonal units with a honeycomb structure. This bonding geometry imposes limitations to the size of the clusters, with unsaturated H-bonds confined to the cluster periphery. It is found that growth proceeds by attachement of water molecules to the edge of the clusters by H-bonds. These molecules bind only weakly to the metal substrate and can hop around the edges. Comparison of DFT and STM image calculations with experiments shows that on Pd the edge-attached molecules form two different structures, a metastable one where the molecule is elevated by 2.7 A with respect to the cluster molecules, and another where they are elevated by only 0.4 A. On Ru only the less elevated (0.4 A higher) edge-attached molecules are observed. In next final step, water structures on Ru(0001) were studied at temperatures above 140K. STM findings were backed by x-ray absorption spectroscopy. Additional DFT calculations and STM simulations provided validation of proposed models. It was found that while undissociated water layers are metastable below 140 K, heating above this temperature produces drastic transformations whereby a fraction of the water molecules partially dissociate and form mixed H 2O-OH structures. XPS and XAS revealed the presence of hydroxyl groups with their O-H bond essentiallymostly parallel to the surface. STM images show that the mixed H2O-OH structures consist of long narrow stripes aligned with the three crystallographic directions perpendicular to the close-packed atomic rows of the Ru(0001) substrate. The internal structure of the stripes is a honeycomb network of H-bonded water and hydroxyl species. We found that the metastable low temperature molecular phase can also be converted to a mixed H2O-OH phase through excitation by the tunneling electrons when their energy is 0.5 eV or higher above the Fermi level. Structural models based on the STM images were used for Density Functional Theory optimizations of the stripes geometry. The optimized geometry was then utilized to calculate STM images for comparison with the experiment.

Nonlinear information fusion algorithms for data-efficient multi-fidelity modelling.

PubMed

Perdikaris, P; Raissi, M; Damianou, A; Lawrence, N D; Karniadakis, G E

2017-02-01

Multi-fidelity modelling enables accurate inference of quantities of interest by synergistically combining realizations of low-cost/low-fidelity models with a small set of high-fidelity observations. This is particularly effective when the low- and high-fidelity models exhibit strong correlations, and can lead to significant computational gains over approaches that solely rely on high-fidelity models. However, in many cases of practical interest, low-fidelity models can only be well correlated to their high-fidelity counterparts for a specific range of input parameters, and potentially return wrong trends and erroneous predictions if probed outside of their validity regime. Here we put forth a probabilistic framework based on Gaussian process regression and nonlinear autoregressive schemes that is capable of learning complex nonlinear and space-dependent cross-correlations between models of variable fidelity, and can effectively safeguard against low-fidelity models that provide wrong trends. This introduces a new class of multi-fidelity information fusion algorithms that provide a fundamental extension to the existing linear autoregressive methodologies, while still maintaining the same algorithmic complexity and overall computational cost. The performance of the proposed methods is tested in several benchmark problems involving both synthetic and real multi-fidelity datasets from computational fluid dynamics simulations.

The pre-Argo ocean reanalyses may be seriously affected by the spatial coverage of moored buoys

PubMed Central

Sivareddy, S.; Paul, Arya; Sluka, Travis; Ravichandran, M.; Kalnay, Eugenia

2017-01-01

Assimilation methods, meant to constrain divergence of model trajectory from reality using observations, do not exactly satisfy the physical laws governing the model state variables. This allows mismatches in the analysis in the vicinity of observation locations where the effect of assimilation is most prominent. These mismatches are usually mitigated either by the model dynamics in between the analysis cycles and/or by assimilation at the next analysis cycle. However, if the observations coverage is limited in space, as it was in the ocean before the Argo era, these mechanisms may be insufficient to dampen the mismatches, which we call shocks, and they may remain and grow. Here we show through controlled experiments, using real and simulated observations in two different ocean models and assimilation systems, that such shocks are generated in the ocean at the lateral boundaries of the moored buoy network. They thrive and propagate westward as Rossby waves along these boundaries. However, these shocks are essentially eliminated by the assimilation of near-homogenous global Argo distribution. These findings question the fidelity of ocean reanalysis products in the pre-Argo era. For example, a reanalysis that ignores Argo floats and assimilates only moored buoys, wrongly represents 2008 as a negative Indian Ocean Dipole year. PMID:28429748

Digital droplet multiple displacement amplification (ddMDA) for whole genome sequencing of limited DNA samples

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

Rhee, Minsoung; Light, Yooli K.; Meagher, Robert J.

Here, multiple displacement amplification (MDA) is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples) before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA) technique where partitioning of the template DNA into thousands of sub-nanoliter droplets, each containing a small number of DNA fragments, greatly reduces the competition among DNA fragments for primers and polymerase thereby greatly reducing amplification bias. Consequently,more » the ddMDA approach enabled a more uniform coverage of amplification over the entire length of the genome, with significantly lower bias and non-specific amplification than conventional MDA. For a sample containing 0.1 pg/μL of E. coli DNA (equivalent of ~3/1000 of an E. coli genome per droplet), ddMDA achieves a 65-fold increase in coverage in de novo assembly, and more than 20-fold increase in specificity (percentage of reads mapping to E. coli) compared to the conventional tube MDA. ddMDA offers a powerful method useful for many applications including medical diagnostics, forensics, and environmental microbiology.« less

Digital droplet multiple displacement amplification (ddMDA) for whole genome sequencing of limited DNA samples

DOE PAGES

Rhee, Minsoung; Light, Yooli K.; Meagher, Robert J.; ...

2016-05-04

Here, multiple displacement amplification (MDA) is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples) before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA) technique where partitioning of the template DNA into thousands of sub-nanoliter droplets, each containing a small number of DNA fragments, greatly reduces the competition among DNA fragments for primers and polymerase thereby greatly reducing amplification bias. Consequently,more » the ddMDA approach enabled a more uniform coverage of amplification over the entire length of the genome, with significantly lower bias and non-specific amplification than conventional MDA. For a sample containing 0.1 pg/μL of E. coli DNA (equivalent of ~3/1000 of an E. coli genome per droplet), ddMDA achieves a 65-fold increase in coverage in de novo assembly, and more than 20-fold increase in specificity (percentage of reads mapping to E. coli) compared to the conventional tube MDA. ddMDA offers a powerful method useful for many applications including medical diagnostics, forensics, and environmental microbiology.« less

Evaluating display fidelity and interaction fidelity in a virtual reality game.

PubMed

McMahan, Ryan P; Bowman, Doug A; Zielinski, David J; Brady, Rachael B

2012-04-01

In recent years, consumers have witnessed a technological revolution that has delivered more-realistic experiences in their own homes through high-definition, stereoscopic televisions and natural, gesture-based video game consoles. Although these experiences are more realistic, offering higher levels of fidelity, it is not clear how the increased display and interaction aspects of fidelity impact the user experience. Since immersive virtual reality (VR) allows us to achieve very high levels of fidelity, we designed and conducted a study that used a six-sided CAVE to evaluate display fidelity and interaction fidelity independently, at extremely high and low levels, for a VR first-person shooter (FPS) game. Our goal was to gain a better understanding of the effects of fidelity on the user in a complex, performance-intensive context. The results of our study indicate that both display and interaction fidelity significantly affect strategy and performance, as well as subjective judgments of presence, engagement, and usability. In particular, performance results were strongly in favor of two conditions: low-display, low-interaction fidelity (representative of traditional FPS games) and high-display, high-interaction fidelity (similar to the real world).

Adaptive Shape Functions and Internal Mesh Adaptation for Modelling Progressive Failure in Adhesively Bonded Joints

NASA Technical Reports Server (NTRS)

Stapleton, Scott; Gries, Thomas; Waas, Anthony M.; Pineda, Evan J.

2014-01-01

Enhanced finite elements are elements with an embedded analytical solution that can capture detailed local fields, enabling more efficient, mesh independent finite element analysis. The shape functions are determined based on the analytical model rather than prescribed. This method was applied to adhesively bonded joints to model joint behavior with one element through the thickness. This study demonstrates two methods of maintaining the fidelity of such elements during adhesive non-linearity and cracking without increasing the mesh needed for an accurate solution. The first method uses adaptive shape functions, where the shape functions are recalculated at each load step based on the softening of the adhesive. The second method is internal mesh adaption, where cracking of the adhesive within an element is captured by further discretizing the element internally to represent the partially cracked geometry. By keeping mesh adaptations within an element, a finer mesh can be used during the analysis without affecting the global finite element model mesh. Examples are shown which highlight when each method is most effective in reducing the number of elements needed to capture adhesive nonlinearity and cracking. These methods are validated against analogous finite element models utilizing cohesive zone elements.

Formation of Au nano-patterns on various substrates using simplified nano-transfer printing method

NASA Astrophysics Data System (ADS)

Kim, Jong-Woo; Yang, Ki-Yeon; Hong, Sung-Hoon; Lee, Heon

2008-06-01

For future device applications, fabrication of the metal nano-patterns on various substrates, such as Si wafer, non-planar glass lens and flexible plastic films become important. Among various nano-patterning technologies, nano-transfer print method is one of the simplest techniques to fabricate metal nano-patterns. In nano-transfer printing process, thin Au layer is deposited on flexible PDMS mold, containing surface protrusion patterns, and the Au layer is transferred from PDMS mold to various substrates due to the difference of bonding strength of Au layer to PDMS mold and to the substrate. For effective transfer of Au layer, self-assembled monolayer, which has strong bonding to Au, is deposited on the substrate as a glue layer. In this study, complicated SAM layer coating process was replaced to simple UV/ozone treatment, which can activates the surface and form the -OH radicals. Using simple UV/ozone treatments on both Au and substrate, Au nano-pattern can be successfully transferred to as large as 6 in. diameter Si wafer, without SAM coating process. High fidelity transfer of Au nano-patterns to non-planar glass lens and flexible PET film was also demonstrated.

3D Bioprinting of Highly Thixotropic Alginate/Methylcellulose Hydrogel with Strong Interface Bonding.

PubMed

Li, Huijun; Tan, Yu Jun; Leong, Kah Fai; Li, Lin

2017-06-14

A robust alginate/methylcellulose (Alg/MC) blend hydrogel, with a strategy to improve adhesion between printed layers, has been fabricated for the first time for three-dimensional (3D) bioprinting. The optimized Alg/MC blend hydrogel exhibits a highly thixotropic property, great extrudability, and stackability. With treatment by a trisodium citrate (TSC) solution, the interfacial bonding between the printed layers is significantly improved. The TSC solution acts as a chelating agent to remove the superficial calcium ions at each layer. Post-cross-linking in a CaCl 2 bath after 3D printing further enhances the adhesion strength between the layers. The key parameters affecting the interfacial strength of the Alg/MC hydrogel are found to be the concentration of TSC, the volume of TSC, and the concentration of CaCl 2 in the bath. The Alg/MC hydrogel with the aid of TSC demonstrates superior printability, high stackability (150 layers can be printed), and high shape fidelity. A good cell viability of >95% is obtained for a freshly 3D-bioprinted Alg/MC construct. The novel Alg/MC hydrogel with the aid of TSC has been shown to have a great potential as an advanced 3D bioprinting material.

Molecular Engineering for Enhanced Charge Transfer in Thin-Film Photoanode.

PubMed

Kim, Jeong Soo; Kim, Byung-Man; Kim, Un-Young; Shin, HyeonOh; Nam, Jung Seung; Roh, Deok-Ho; Park, Jun-Hyeok; Kwon, Tae-Hyuk

2017-10-11

We developed three types of dithieno[3,2-b;2',3'-d]thiophene (DTT)-based organic sensitizers for high-performance thin photoactive TiO 2 films and investigated the simple but powerful molecular engineering of different types of bonding between the triarylamine electron donor and the conjugated DTT π-bridge by the introduction of single, double, and triple bonds. As a result, with only 1.3 μm transparent and 2.5-μm TiO 2 scattering layers, the triple-bond sensitizer (T-DAHTDTT) shows the highest power conversion efficiency (η = 8.4%; V OC = 0.73 V, J SC = 15.4 mA·cm -2 , and FF = 0.75) in an iodine electrolyte system under one solar illumination (AM 1.5, 1000 W·m -2 ), followed by the single-bond sensitizer (S-DAHTDTT) (η = 7.6%) and the double-bond sensitizer (D-DAHTDTT) (η = 6.4%). We suggest that the superior performance of T-DAHTDTT comes from enhanced intramolecular charge transfer (ICT) induced by the triple bond. Consequently, T-DAHTDTT exhibits the most active photoelectron injection and charge transport on a TiO 2 film during operation, which leads to the highest photocurrent density among the systems studied. We analyzed these correlations mainly in terms of charge injection efficiency, level of photocharge storage, and charge-transport kinetics. This study suggests that the molecular engineering of a triple bond between the electron donor and the π-bridge of a sensitizer increases the performance of dye-sensitized solar cell (DSC) with a thin photoactive film by enhancing not only J SC through improved ICT but also V OC through the evenly distributed sensitizer surface coverage.

Film growth, adsorption and desorption kinetics of indigo on SiO2

PubMed Central

Scherwitzl, Boris; Resel, Roland; Winkler, Adolf

2015-01-01

Organic dyes have recently been discovered as promising semiconducting materials, attributable to the formation of hydrogen bonds. In this work, the adsorption and desorption behavior, as well as thin film growth was studied in detail for indigo molecules on silicon dioxide with different substrate treatments. The material was evaporated onto the substrate by means of physical vapor deposition under ultra-high vacuum conditions and was subsequently studied by Thermal Desorption Spectroscopy (TDS), Auger Electron Spectroscopy, X-Ray Diffraction, and Atomic Force Microscopy. TDS revealed initially adsorbed molecules to be strongly bonded on a sputter cleaned surface. After further deposition a formation of dimers is suggested, which de-stabilizes the bonding mechanism to the substrate and leads to a weakly bonded adsorbate. The dimers are highly mobile on the surface until they get incorporated into energetically favourable three-dimensional islands in a dewetting process. The stronger bonding of molecules within those islands could be shown by a higher desorption temperature. On a carbon contaminated surface no strongly bonded molecules appeared initially, weakly bonded monomers rather rearrange into islands at a surface coverage that is equivalent to one third of a monolayer of flat-lying molecules. The sticking coefficient was found to be unity on both substrates. The desorption energies from carbon covered silicon dioxide calculated to 1.67 ± 0.05 eV for multilayer desorption from the islands and 0.84 ± 0.05 eV for monolayer des orption. Corresponding values for desorption from a sputter cleaned surface are 1.53 ± 0.05 eV for multilayer and 0.83 ± 0.05 eV for monolayer desorption. PMID:24832297

Film growth, adsorption and desorption kinetics of indigo on SiO{sub 2}

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

Scherwitzl, Boris, E-mail: b.scherwitzl@tugraz.at; Resel, Roland; Winkler, Adolf

2014-05-14

Organic dyes have recently been discovered as promising semiconducting materials, attributable to the formation of hydrogen bonds. In this work, the adsorption and desorption behavior, as well as thin film growth was studied in detail for indigo molecules on silicon dioxide with different substrate treatments. The material was evaporated onto the substrate by means of physical vapor deposition under ultra-high vacuum conditions and was subsequently studied by Thermal Desorption Spectroscopy (TDS), Auger Electron Spectroscopy, X-Ray Diffraction, and Atomic Force Microscopy. TDS revealed initially adsorbed molecules to be strongly bonded on a sputter cleaned surface. After further deposition a formation ofmore » dimers is suggested, which de-stabilizes the bonding mechanism to the substrate and leads to a weakly bonded adsorbate. The dimers are highly mobile on the surface until they get incorporated into energetically favourable three-dimensional islands in a dewetting process. The stronger bonding of molecules within those islands could be shown by a higher desorption temperature. On a carbon contaminated surface no strongly bonded molecules appeared initially, weakly bonded monomers rather rearrange into islands at a surface coverage that is equivalent to one third of a monolayer of flat-lying molecules. The sticking coefficient was found to be unity on both substrates. The desorption energies from carbon covered silicon dioxide calculated to 1.67 ± 0.05 eV for multilayer desorption from the islands and 0.84 ± 0.05 eV for monolayer desorption. Corresponding values for desorption from a sputter cleaned surface are 1.53 ± 0.05 eV for multilayer and 0.83 ± 0.05 eV for monolayer desorption.« less

Film growth, adsorption and desorption kinetics of indigo on SiO2.

PubMed

Scherwitzl, Boris; Resel, Roland; Winkler, Adolf

2014-05-14

Organic dyes have recently been discovered as promising semiconducting materials, attributable to the formation of hydrogen bonds. In this work, the adsorption and desorption behavior, as well as thin film growth was studied in detail for indigo molecules on silicon dioxide with different substrate treatments. The material was evaporated onto the substrate by means of physical vapor deposition under ultra-high vacuum conditions and was subsequently studied by Thermal Desorption Spectroscopy (TDS), Auger Electron Spectroscopy, X-Ray Diffraction, and Atomic Force Microscopy. TDS revealed initially adsorbed molecules to be strongly bonded on a sputter cleaned surface. After further deposition a formation of dimers is suggested, which de-stabilizes the bonding mechanism to the substrate and leads to a weakly bonded adsorbate. The dimers are highly mobile on the surface until they get incorporated into energetically favourable three-dimensional islands in a dewetting process. The stronger bonding of molecules within those islands could be shown by a higher desorption temperature. On a carbon contaminated surface no strongly bonded molecules appeared initially, weakly bonded monomers rather rearrange into islands at a surface coverage that is equivalent to one third of a monolayer of flat-lying molecules. The sticking coefficient was found to be unity on both substrates. The desorption energies from carbon covered silicon dioxide calculated to 1.67 ± 0.05 eV for multilayer desorption from the islands and 0.84 ± 0.05 eV for monolayer desorption. Corresponding values for desorption from a sputter cleaned surface are 1.53 ± 0.05 eV for multilayer and 0.83 ± 0.05 eV for monolayer desorption.

Formation and hydrolysis of amide bonds by lipase A from Candida antarctica; exceptional features.

PubMed

Liljeblad, Arto; Kallio, Pauli; Vainio, Marita; Niemi, Jarmo; Kanerva, Liisa T

2010-02-21

Various commercial lyophilized and immobilized preparations of lipase A from Candida antarctica (CAL-A) were studied for their ability to catalyze the hydrolysis of amide bonds in N-acylated alpha-amino acids, 3-butanamidobutanoic acid (beta-amino acid) and its ethyl ester. The activity toward amide bonds is highly untypical of lipases, despite the close mechanistic analogy to amidases which normally catalyze the corresponding reactions. Most CAL-A preparations cleaved amide bonds of various substrates with high enantioselectivity, although high variations in substrate selectivity and catalytic rates were detected. The possible role of contaminant protein species on the hydrolytic activity toward these bonds was studied by fractionation and analysis of the commercial lyophilized preparation of CAL-A (Cat#ICR-112, Codexis). In addition to minor impurities, two equally abundant proteins were detected, migrating on SDS-PAGE a few kDa apart around the calculated size of CAL-A. Based on peptide fragment analysis and sequence comparison both bands shared substantial sequence coverage with CAL-A. However, peptides at the C-terminal end constituting a motile domain described as an active-site flap were not identified in the smaller fragment. Separated gel filtration fractions of the two forms of CAL-A both catalyzed the amide bond hydrolysis of ethyl 3-butanamidobutanoate as well as the N-acylation of methyl pipecolinate. Hydrolytic activity towards N-acetylmethionine was, however, solely confined to the fractions containing the truncated form of CAL-A. These fractions were also found to contain a trace enzyme impurity identified in sequence analysis as a serine carboxypeptidase. The possible role of catalytic impurities versus the function of CAL-A in amide bond hydrolysis is further discussed in the paper.

Learning nursing procedures: the influence of simulator fidelity and student gender on teaching effectiveness.

PubMed

Grady, Janet L; Kehrer, Rosemary G; Trusty, Carole E; Entin, Eileen B; Entin, Elliot E; Brunye, Tad T

2008-09-01

Simulation technologies are gaining widespread acceptance across a variety of educational domains and applications. The current research examines whether basic nursing procedure training with high-fidelity versus low-fidelity mannequins results in differential skill acquisition and perceptions of simulator utility. Fifty-two first-year students were taught nasogastric tube and indwelling urinary catheter insertion in one of two ways. The first group learned nasogastric tube and urinary catheter insertion using high-fidelity and low-fidelity mannequins, respectively, and the second group learned nasogastric tube and urinary catheter insertion using low-fidelity and high-fidelity mannequins, respectively. The dependent measures included student performance on nasogastric tube and urinary catheter insertion testing, as measured by observer-based instruments, and self-report questionnaires probing student attitudes about the use of simulation in nursing education. Results demonstrated higher performance with high-fidelity than with low-fidelity mannequin training. In response to a self-report posttraining questionnaire, participants expressed a more positive attitude toward the high-fidelity mannequin, especially regarding its responsiveness and realism.

Estimating debt capacity of New York State Health facilities.

PubMed

Hogan, A J

1985-01-01

A measure of the capacity to take on new debt is developed for health facilities. This measure is a function of the current financial position of the facility, future financial market conditions (interest rates and bond/loan maturities), and a policy variable (the debt service coverage ratio) to be set by state health policy makers. The quality of this measure was shown to depend on the quality of current health facility financial accounting data, on the quality of forecasts of interest rates and future cashflow, and on the appropriateness of the criterion debt service coverage ratio. Some of the limitations of the estimate are discussed. Consideration of the debt capacity estimate serves to highlight some crucial issues in imposing capital expenditure limits, namely the interrelationships between financial viability, interest rates and access to capital markets.

Metal/silicon Interfaces and Their Oxidation Behavior - Photoemission Spectroscopy Analysis.

NASA Astrophysics Data System (ADS)

Yeh, Jyh-Jye

Synchrotron radiation photoemission spectroscopy was used to study Ni/Si and Au/Si interface properties on the atomic scale at room temperature, after high temperature annealing and after oxygen exposures. Room temperature studies of metal/Si interfaces provide background for an understanding of the interface structure after elevated temperature annealing. Oxidation studies of Si surfaces covered with metal overlayers yield insight about the effect of metal atoms in the Si oxidation mechanisms and are useful in the identification of subtle differences in bonding relations between atoms at the metal/Si interfaces. Core level and valence band spectra with variable surface sensitivities were used to study the interactions between metal, Si, and oxygen for metal coverages and oxide thickness in the monolayer region. Interface morphology at the initial stage of metal/Si interface formation and after oxidation was modeled on the basis of the evolutions of metal and Si signals at different probing depths in the photoemission experiment. Both Ni/Si and Au/Si interfaces formed at room temperature have a diffusive region at the interface. This is composed of a layer of metal-Si alloy, formed by Si outdiffusion into the metal overlayer, above a layer of interstitial metal atoms in the Si substrate. Different atomic structures of these two regions at Ni/Si interface can account for the two different growth orientations of epitaxial Ni disilicides on the Si(111) surface after thermal annealing. Annealing the Au/Si interface at high temperature depletes all the Au atoms except for one monolayer of Au on the Si(111) surface. These phenomena are attributed to differences in the metal-Si chemical bonding relations associated with specific atomic structures. After oxygen exposures, both the Ni disilicide surface and Au covered Si surfaces (with different coverages and surface orderings) show silicon in higher oxidation states, in comparison to oxidized silicon on a clean surface. Preferential Si dioxide growth on the Au/Si surface is related to the strong distortion of the Si lattice when Au-Si bonds are formed. In comparison, a monolayer of Ni on a Si surface, with its weaker Ni-Si bond, does not enhance oxide formation.

Conversion of 1,3-Propylene Glycol on Rutile TiO2(110)

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

Chen, Long; Li, Zhenjun; Smith, R. Scott

2014-10-09

The adsorption of 1,3-propylene glycol (1,3-PG) on partially reduced TiO2(110) and its conversion to products have been studied by a combination of molecular beam dosing and temperature programmed desorption (TPD). When the Ti surface sites are saturated by 1,3-PG, ~80% of the molecules undergo further reactions to yield products that are liberated during the TPD ramp. In contrast to ethylene glycol (EG) and 1,2- propylene glycol (1,2-PG) that yield only alkenes and water at very low coverages (< 0.05 ML), two additional products, HCHO and C2H4, along with propylene (CH3CHCH2) and water are observed for 1,3-PG. Identical TPD line shapesmore » and desorption yields for HCHO and C2H4 suggest that these products result from C-C bond cleavage and are coupled. At higher 1,3-PG coverages (> 0.1 ML), propanal (CH3CH2CHO) and two additional products, 1-propanol (CH3CH2CH2OH) and acrolein (CH2CHCHO), are observed. The desorption of 1-propanol is found to be coupled with the desorption of acrolein, suggesting that these products are formed by the disproportionation of two 1,3-PG molecules. The coverage dependent TPD results further show that propylene formation dominates at low coverages (< 0.3 ML), while the decomposition and disproportionation channels increase rapidly at higher coverages and reach yields comparable to that of propylene at the 1,3-PG saturation coverage of 0.5 ML. The observed surface chemistry clearly shows how the molecular structure of glycols influences their reaction pathways on oxide surfaces.« less

Identification of Critical Residues for the Tight Binding of Both Correct and Incorrect Nucleotides to Human DNA Polymerase λ

PubMed Central

Brown, Jessica A.; Pack, Lindsey R.; Sherrer, Shanen M.; Kshetry, Ajay K.; Newmister, Sean A.; Fowler, Jason D.; Taylor, John-Stephen; Suo, Zucai

2010-01-01

DNA polymerase λ (Pol λ) is a novel X-family DNA polymerase that shares 34% sequence identity with DNA polymerase β (Pol β). Pre-steady state kinetic studies have shown that the Pol λ•DNA complex binds both correct and incorrect nucleotides 130-fold tighter on average than the Pol β•DNA complex, although, the base substitution fidelity of both polymerases is 10−4 to 10−5. To better understand Pol λ’s tight nucleotide binding affinity, we created single- and double-substitution mutants of Pol λ to disrupt interactions between active site residues and an incoming nucleotide or a template base. Single-turnover kinetic assays showed that Pol λ binds to an incoming nucleotide via cooperative interactions with active site residues (R386, R420, K422, Y505, F506, A510, and R514). Disrupting protein interactions with an incoming correct or incorrect nucleotide impacted binding with each of the common structural moieties in the following order: triphosphate ≫ base > ribose. In addition, the loss of Watson-Crick hydrogen bonding between the nucleotide and template base led to a moderate increase in the Kd. The fidelity of Pol λ was maintained predominantly by a single residue, R517, which has minor groove interactions with the DNA template. PMID:20851705

Modeling Charge Collection in Detector Arrays

NASA Technical Reports Server (NTRS)

Hardage, Donna (Technical Monitor); Pickel, J. C.

2003-01-01

A detector array charge collection model has been developed for use as an engineering tool to aid in the design of optical sensor missions for operation in the space radiation environment. This model is an enhancement of the prototype array charge collection model that was developed for the Next Generation Space Telescope (NGST) program. The primary enhancements were accounting for drift-assisted diffusion by Monte Carlo modeling techniques and implementing the modeling approaches in a windows-based code. The modeling is concerned with integrated charge collection within discrete pixels in the focal plane array (FPA), with high fidelity spatial resolution. It is applicable to all detector geometries including monolithc charge coupled devices (CCDs), Active Pixel Sensors (APS) and hybrid FPA geometries based on a detector array bump-bonded to a readout integrated circuit (ROIC).

Implementation fidelity trajectories of a health promotion program in multidisciplinary settings: managing tensions in rehabilitation care.

PubMed

Hoekstra, Femke; van Offenbeek, Marjolein A G; Dekker, Rienk; Hettinga, Florentina J; Hoekstra, Trynke; van der Woude, Lucas H V; van der Schans, Cees P

2017-12-01

Although the importance of evaluating implementation fidelity is acknowledged, little is known about heterogeneity in fidelity over time. This study aims to generate insight into the heterogeneity in implementation fidelity trajectories of a health promotion program in multidisciplinary settings and the relationship with changes in patients' health behavior. This study used longitudinal data from the nationwide implementation of an evidence-informed physical activity promotion program in Dutch rehabilitation care. Fidelity scores were calculated based on annual surveys filled in by involved professionals (n = ± 70). Higher fidelity scores indicate a more complete implementation of the program's core components. A hierarchical cluster analysis was conducted on the implementation fidelity scores of 17 organizations at three different time points. Quantitative and qualitative data were used to explore organizational and professional differences between identified trajectories. Regression analyses were conducted to determine differences in patient outcomes. Three trajectories were identified as the following: 'stable high fidelity' (n = 9), 'moderate and improving fidelity' (n = 6), and 'unstable fidelity' (n = 2). The stable high fidelity organizations were generally smaller, started earlier, and implemented the program in a more structured way compared to moderate and improving fidelity organizations. At the implementation period's start and end, support from physicians and physiotherapists, professionals' appreciation, and program compatibility were rated more positively by professionals working in stable high fidelity organizations as compared to the moderate and improving fidelity organizations (p < .05). Qualitative data showed that the stable high fidelity organizations had often an explicit vision and strategy about the implementation of the program. Intriguingly, the trajectories were not associated with patients' self-reported physical activity outcomes (adjusted model β = - 651.6, t(613) = - 1032, p = .303). Differences in organizational-level implementation fidelity trajectories did not result in outcome differences at patient-level. This suggests that an effective implementation fidelity trajectory is contingent on the local organization's conditions. More specifically, achieving stable high implementation fidelity required the management of tensions: realizing a localized change vision, while safeguarding the program's standardized core components and engaging the scarce physicians throughout the process. When scaling up evidence-informed health promotion programs, we propose to tailor the management of implementation tensions to local organizations' starting position, size, and circumstances. The Netherlands National Trial Register NTR3961 . Registered 18 April 2013.

Multilayer Dye Aggregation at Dye/TiO2 Interface via π…π Stacking and Hydrogen Bond and Its Impact on Solar Cell Performance: A DFT Analysis.

PubMed

Zhang, Lei; Liu, Xiaogang; Rao, Weifeng; Li, Jingfa

2016-10-21

Multilayer dye aggregation at the dye/TiO 2 interface of dye-sensitized solar cells is probed via first principles calculations, using p-methyl red azo dye as an example. Our calculations suggest that the multilayer dye aggregates at the TiO 2 surface can be stabilized by π…π stacking and hydrogen bond interactions. Compared with previous two-dimensional monolayer dye/TiO 2 model, the multilayer dye aggregation model proposed in this study constructs a three-dimensional multilayer dye/TiO 2 interfacial structure, and provides a better agreement between experimental and computational results in dye coverage and dye adsorption energy. In particular, a dimer forms by π…π stacking interactions between two neighboring azo molecules, while one of them chemisorbs on the TiO 2 surface; a trimer may form by introducing one additional azo molecule on the dimer through a hydrogen bond between two carboxylic acid groups. Different forms of multilayer dye aggregates, either stabilized by π…π stacking or hydrogen bond, exhibit varied optical absorption spectra and electronic properties. Such variations could have a critical impact on the performance of dye sensitized solar cells.

Multilayer Dye Aggregation at Dye/TiO2 Interface via π…π Stacking and Hydrogen Bond and Its Impact on Solar Cell Performance: A DFT Analysis

PubMed Central

Zhang, Lei; Liu, Xiaogang; Rao, Weifeng; Li, Jingfa

2016-01-01

Multilayer dye aggregation at the dye/TiO2 interface of dye-sensitized solar cells is probed via first principles calculations, using p-methyl red azo dye as an example. Our calculations suggest that the multilayer dye aggregates at the TiO2 surface can be stabilized by π…π stacking and hydrogen bond interactions. Compared with previous two-dimensional monolayer dye/TiO2 model, the multilayer dye aggregation model proposed in this study constructs a three-dimensional multilayer dye/TiO2 interfacial structure, and provides a better agreement between experimental and computational results in dye coverage and dye adsorption energy. In particular, a dimer forms by π…π stacking interactions between two neighboring azo molecules, while one of them chemisorbs on the TiO2 surface; a trimer may form by introducing one additional azo molecule on the dimer through a hydrogen bond between two carboxylic acid groups. Different forms of multilayer dye aggregates, either stabilized by π…π stacking or hydrogen bond, exhibit varied optical absorption spectra and electronic properties. Such variations could have a critical impact on the performance of dye sensitized solar cells. PMID:27767196

The effects of chain length, embedded polar groups, pressure, and pore shape on structure and retention in reversed-phase liquid chromatography: molecular-level insights from Monte Carlo simulations.

PubMed

Rafferty, Jake L; Siepmann, J Ilja; Schure, Mark R

2009-03-20

Particle-based simulations using the configurational-bias and Gibbs ensemble Monte Carlo techniques are carried out to probe the effects of various chromatographic parameters on bonded-phase chain conformation, solvent penetration, and retention in reversed-phase liquid chromatography (RPLC). Specifically, we investigate the effects due to the length of the bonded-phase chains (C(18), C(8), and C(1)), the inclusion of embedded polar groups (amide and ether) near the base of the bonded-phase chains, the column pressure (1, 400, and 1000 atm), and the pore shape (planar slit pore versus cylindrical pore with a 60A diameter). These simulations utilize a bonded-phase coverage of 2.9 micromol/m(2)and a mobile phase containing methanol at a molfraction of 33% (about 50% by volume). The simulations show that chain length, embedded polar groups, and pore shape significantly alter structural and retentive properties of the model RPLC system, whereas the column pressure has a relatively small effect. The simulation results are extensively compared to retention measurements. A molecular view of the RPLC retention mechanism emerges that is more complex than can be inferred from thermodynamic measurements.

The effect of bench model fidelity on fluoroscopy-guided transforaminal epidural injection training: a randomized control study.

PubMed

Gonzalez-Cota, Alan; Chiravuri, Srinivas; Stansfield, R Brent; Brummett, Chad M; Hamstra, Stanley J

2013-01-01

The purpose of this study was to determine whether high-fidelity simulators provide greater benefit than low-fidelity models in training fluoroscopy-guided transforaminal epidural injection. This educational study was a single-center, prospective, randomized 3-arm pretest-posttest design with a control arm. Eighteen anesthesia and physical medicine and rehabilitation residents were instructed how to perform a fluoroscopy-guided transforaminal epidural injection and assessed by experts on a reusable injectable phantom cadaver. The high- and low-fidelity groups received 30 minutes of supervised hands-on practice according to group assignment, and the control group received 30 minutes of didactic instruction from an expert. We found no differences at posttest between the high- and low-fidelity groups on global ratings of performance (P = 0.17) or checklist scores (P = 0.81). Participants who received either form of hands-on training significantly outperformed the control group on both the global rating of performance (control vs low-fidelity, P = 0.0048; control vs high-fidelity, P = 0.0047) and the checklist (control vs low-fidelity, P = 0.0047; control vs high-fidelity, P = 0.0047). Training an epidural procedure using a low-fidelity model may be equally effective as training on a high-fidelity model. These results are consistent with previous research on a variety of interventional procedures and further demonstrate the potential impact of simple, low-fidelity training models.

Synthesis and characterization of a novel long-alkyl-chain ester-substituted benzimidazole gelator and its octan-1-ol solvate.

PubMed

Geiger, H Cristina; Zick, Patricia L; Roberts, William R; Geiger, David K

2017-04-01

The synthesis of a novel benzimidazole derivative with a long-chain-ester substituent, namely methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan-1-ol solvate, methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate octan-1-ol monosolvate, C 22 H 26 N 2 O 3 ·C 8 H 18 O, (4), exhibits a four-molecule hydrogen-bonded motif in the solid state, with N-H...O hydrogen bonds between benzimidazole molecules and O-H...N hydrogen bonds between the octan-1-ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan-1-ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H...C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C-H...π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed.

Testing the Feasibility of Fidelity Evaluation in a Multisite, Multiprogram Initiative

ERIC Educational Resources Information Center

Cornish, Disa Lubker; Losch, Mary E.; Avery, Mitchell

2016-01-01

Monitoring fidelity of implementation is a critical task when initiating evidence-based programs. This pilot study sought to identify best practices in a fidelity monitoring process and determine the feasibility of continuing a fidelity monitoring process with a multisite, multiprogram initiative. A fidelity log was created for each of 11…

Testing the Relation between Fidelity of Implementation and Student Outcomes in Math

ERIC Educational Resources Information Center

Crawford, Lindy; Carpenter, Dick M., II; Wilson, Mary T.; Schmeister, Megan; McDonald, Marilee

2012-01-01

The relation between fidelity of implementation and student outcomes in a computer-based middle school mathematics curriculum was measured empirically. Participants included 485 students and 23 teachers from 11 public middle schools across seven states. Implementation fidelity was defined using two constructs: fidelity to structure and fidelity to…

An information theoretic approach to use high-fidelity codes to calibrate low-fidelity codes

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

Lewis, Allison, E-mail: lewis.allison10@gmail.com; Smith, Ralph; Williams, Brian

For many simulation models, it can be prohibitively expensive or physically infeasible to obtain a complete set of experimental data to calibrate model parameters. In such cases, one can alternatively employ validated higher-fidelity codes to generate simulated data, which can be used to calibrate the lower-fidelity code. In this paper, we employ an information-theoretic framework to determine the reduction in parameter uncertainty that is obtained by evaluating the high-fidelity code at a specific set of design conditions. These conditions are chosen sequentially, based on the amount of information that they contribute to the low-fidelity model parameters. The goal is tomore » employ Bayesian experimental design techniques to minimize the number of high-fidelity code evaluations required to accurately calibrate the low-fidelity model. We illustrate the performance of this framework using heat and diffusion examples, a 1-D kinetic neutron diffusion equation, and a particle transport model, and include initial results from the integration of the high-fidelity thermal-hydraulics code Hydra-TH with a low-fidelity exponential model for the friction correlation factor.« less

All-Systolic Non-ECG-gated Myocardial Perfusion MRI: Feasibility of Multi-Slice Continuous First-Pass Imaging

PubMed Central

Sharif, Behzad; Arsanjani, Reza; Dharmakumar, Rohan; Bairey Merz, C. Noel; Berman, Daniel S.; Li, Debiao

2015-01-01

Purpose To develop and test the feasibility of a new method for non-ECG-gated first-pass perfusion (FPP) cardiac MR capable of imaging multiple short-axis slices at the same systolic cardiac phase. Methods A magnetization-driven pulse sequence was developed for non-ECG-gated FPP imaging without saturation-recovery preparation using continuous slice-interleaved radial sampling. The image reconstruction method, dubbed TRACE, employed self-gating based on reconstruction of a real-time image-based navigator combined with reference-constrained compressed sensing. Data from ischemic animal studies (n=5) was used in a simulation framework to evaluate temporal fidelity. Healthy subjects (n=5) were studied using both the proposed and conventional method to compare the myocardial contrast-to-noise ratio (CNR). Patients (n=2) underwent adenosine stress studies using the proposed method. Results Temporal fidelity of the developed method was shown to be sufficient at high heart-rates. The healthy volunteers studies demonstrated normal perfusion and no artifacts. Compared to the conventional scheme, myocardial CNR for the proposed method was slightly higher (8.6±0.6 vs. 8.0±0.7). Patient studies showed stress-induced perfusion defects consistent with invasive angiography. Conclusions The presented methods and results demonstrate feasibility of the proposed approach for high-resolution non-ECG-gated FPP imaging and indicate its potential for achieving desirable image quality (high CNR, no dark-rim artifacts) with a 3-slice spatial coverage, all imaged at the same systolic phase. PMID:26052843

Vibrational Studies of Adsorbate-Induced Reconstruction on Molybdenum Surfaces.

NASA Astrophysics Data System (ADS)

Lopinski, Gregory Peter

Adsorbate-induced rearrangement of the substrate structure strongly modifies the adsorbate-substrate and adsorbate-adsorbate interactions, leading to the complex behavior observed in many chemisorption systems. In this thesis the H/Mo(211), O/Mo(211) and Na/Mo(100) systems have been studied using high resolution electron energy loss spectroscopy (HREELS) to observe vibrations of the adsorbed atoms. The vibrational data is correlated with observations of the long-range order probed by LEED as well as the work function changes induced by adsorption. Adsorbate -induced substrate reconstruction plays an important role in all three of these systems. Studies of the coadsorption systems O+H/Mo(211) and Na+O/Mo(100) indicate how these effects can influence interactions between adsorbates. For H/Mo(211), above 1ML a (1 x 1) to (1 x 2) transition is observed and attributed to modification of the substrate periodicity. Below 1ML, H atoms are bridge bonded and induce local distortions of the substrate. The transition to the (1 x 2) phase involves the ordering of these displacements and occupation of three-fold sites partially populated by conversion of the bridge bonded species. This conversion accounts for the sawtooth-like coverage dependence of the work function. The structural model proposed for this system is also supported by the desorption parameters and partial molar entropy extracted from adsorption isobars. Oxygen adsorption on Mo(211) involves the occupation of multiple binding sites, with both the long-range order and the local geometry of the adsorbate phases strongly temperature dependent. Coadsorption of low coverages of oxygen and hydrogen leads to segregation of the two adsorbates which can be understood in terms of a substrate-mediated repulsive interaction between O and H. For Na/Mo(100), the frequency of the Na-Mo symmetric stretch mode does not shift with coverage although the mode intensity is strongly coverage dependent. The absence of a frequency shift as well as the form of the observed coverage dependence differ from the predictions of the traditional charge transfer model of alkali adsorption. The relevance of the vibrational results to the Na-induced structural changes observed on this surface are also discussed. Na adsorption has been found to dramatically alter the interaction of oxygen with this surface, due to the presence of a strong attractive interaction between Na and O that forces O atoms to occupy a different binding site than on a clean surface.

Development of Adaptive Model Refinement (AMoR) for Multiphysics and Multifidelity Problems

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

Turinsky, Paul

This project investigated the development and utilization of Adaptive Model Refinement (AMoR) for nuclear systems simulation applications. AMoR refers to utilization of several models of physical phenomena which differ in prediction fidelity. If the highest fidelity model is judged to always provide or exceeded the desired fidelity, than if one can determine the difference in a Quantity of Interest (QoI) between the highest fidelity model and lower fidelity models, one could utilize the fidelity model that would just provide the magnitude of the QoI desired. Assuming lower fidelity models require less computational resources, in this manner computational efficiency can bemore » realized provided the QoI value can be accurately and efficiently evaluated. This work utilized Generalized Perturbation Theory (GPT) to evaluate the QoI, by convoluting the GPT solution with the residual of the highest fidelity model determined using the solution from lower fidelity models. Specifically, a reactor core neutronics problem and thermal-hydraulics problem were studied to develop and utilize AMoR. The highest fidelity neutronics model was based upon the 3D space-time, two-group, nodal diffusion equations as solved in the NESTLE computer code. Added to the NESTLE code was the ability to determine the time-dependent GPT neutron flux. The lower fidelity neutronics model was based upon the point kinetics equations along with utilization of a prolongation operator to determine the 3D space-time, two-group flux. The highest fidelity thermal-hydraulics model was based upon the space-time equations governing fluid flow in a closed channel around a heat generating fuel rod. The Homogenous Equilibrium Mixture (HEM) model was used for the fluid and Finite Difference Method was applied to both the coolant and fuel pin energy conservation equations. The lower fidelity thermal-hydraulic model was based upon the same equations as used for the highest fidelity model but now with coarse spatial meshing, corrected somewhat by employing effective fuel heat conduction values. The effectiveness of switching between the highest fidelity model and lower fidelity model as a function of time was assessed using the neutronics problem. Based upon work completed to date, one concludes that the time switching is effective in annealing out differences between the highest and lower fidelity solutions. The effectiveness of using a lower fidelity GPT solution, along with a prolongation operator, to estimate the QoI was also assessed. The utilization of a lower fidelity GPT solution was done in an attempt to avoid the high computational burden associated with solving for the highest fidelity GPT solution. Based upon work completed to date, one concludes that the lower fidelity adjoint solution is not sufficiently accurate with regard to estimating the QoI; however, a formulation has been revealed that may provide a path for addressing this shortcoming.« less

Complete tomography of a high-fidelity solid-state entangled spin-photon qubit pair.

PubMed

De Greve, Kristiaan; McMahon, Peter L; Yu, Leo; Pelc, Jason S; Jones, Cody; Natarajan, Chandra M; Kim, Na Young; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Hadfield, Robert H; Forchel, Alfred; Fejer, M M; Yamamoto, Yoshihisa

2013-01-01

Entanglement between stationary quantum memories and photonic qubits is crucial for future quantum communication networks. Although high-fidelity spin-photon entanglement was demonstrated in well-isolated atomic and ionic systems, in the solid-state, where massively parallel, scalable networks are most realistically conceivable, entanglement fidelities are typically limited due to intrinsic environmental interactions. Distilling high-fidelity entangled pairs from lower-fidelity precursors can act as a remedy, but the required overhead scales unfavourably with the initial entanglement fidelity. With spin-photon entanglement as a crucial building block for entangling quantum network nodes, obtaining high-fidelity entangled pairs becomes imperative for practical realization of such networks. Here we report the first results of complete state tomography of a solid-state spin-photon-polarization-entangled qubit pair, using a single electron-charged indium arsenide quantum dot. We demonstrate record-high fidelity in the solid-state of well over 90%, and the first (99.9%-confidence) achievement of a fidelity that will unambiguously allow for entanglement distribution in solid-state quantum repeater networks.

Gaussian functional regression for output prediction: Model assimilation and experimental design

NASA Astrophysics Data System (ADS)

Nguyen, N. C.; Peraire, J.

2016-03-01

In this paper, we introduce a Gaussian functional regression (GFR) technique that integrates multi-fidelity models with model reduction to efficiently predict the input-output relationship of a high-fidelity model. The GFR method combines the high-fidelity model with a low-fidelity model to provide an estimate of the output of the high-fidelity model in the form of a posterior distribution that can characterize uncertainty in the prediction. A reduced basis approximation is constructed upon the low-fidelity model and incorporated into the GFR method to yield an inexpensive posterior distribution of the output estimate. As this posterior distribution depends crucially on a set of training inputs at which the high-fidelity models are simulated, we develop a greedy sampling algorithm to select the training inputs. Our approach results in an output prediction model that inherits the fidelity of the high-fidelity model and has the computational complexity of the reduced basis approximation. Numerical results are presented to demonstrate the proposed approach.

Deep whole-genome sequencing of 100 southeast Asian Malays.

PubMed

Wong, Lai-Ping; Ong, Rick Twee-Hee; Poh, Wan-Ting; Liu, Xuanyao; Chen, Peng; Li, Ruoying; Lam, Kevin Koi-Yau; Pillai, Nisha Esakimuthu; Sim, Kar-Seng; Xu, Haiyan; Sim, Ngak-Leng; Teo, Shu-Mei; Foo, Jia-Nee; Tan, Linda Wei-Lin; Lim, Yenly; Koo, Seok-Hwee; Gan, Linda Seo-Hwee; Cheng, Ching-Yu; Wee, Sharon; Yap, Eric Peng-Huat; Ng, Pauline Crystal; Lim, Wei-Yen; Soong, Richie; Wenk, Markus Rene; Aung, Tin; Wong, Tien-Yin; Khor, Chiea-Chuen; Little, Peter; Chia, Kee-Seng; Teo, Yik-Ying

2013-01-10

Whole-genome sequencing across multiple samples in a population provides an unprecedented opportunity for comprehensively characterizing the polymorphic variants in the population. Although the 1000 Genomes Project (1KGP) has offered brief insights into the value of population-level sequencing, the low coverage has compromised the ability to confidently detect rare and low-frequency variants. In addition, the composition of populations in the 1KGP is not complete, despite the fact that the study design has been extended to more than 2,500 samples from more than 20 population groups. The Malays are one of the Austronesian groups predominantly present in Southeast Asia and Oceania, and the Singapore Sequencing Malay Project (SSMP) aims to perform deep whole-genome sequencing of 100 healthy Malays. By sequencing at a minimum of 30× coverage, we have illustrated the higher sensitivity at detecting low-frequency and rare variants and the ability to investigate the presence of hotspots of functional mutations. Compared to the low-pass sequencing in the 1KGP, the deeper coverage allows more functional variants to be identified for each person. A comparison of the fidelity of genotype imputation of Malays indicated that a population-specific reference panel, such as the SSMP, outperforms a cosmopolitan panel with larger number of individuals for common SNPs. For lower-frequency (<5%) markers, a larger number of individuals might have to be whole-genome sequenced so that the accuracy currently afforded by the 1KGP can be achieved. The SSMP data are expected to be the benchmark for evaluating the value of deep population-level sequencing versus low-pass sequencing, especially in populations that are poorly represented in population-genetics studies. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Deep Whole-Genome Sequencing of 100 Southeast Asian Malays

PubMed Central

Wong, Lai-Ping; Ong, Rick Twee-Hee; Poh, Wan-Ting; Liu, Xuanyao; Chen, Peng; Li, Ruoying; Lam, Kevin Koi-Yau; Pillai, Nisha Esakimuthu; Sim, Kar-Seng; Xu, Haiyan; Sim, Ngak-Leng; Teo, Shu-Mei; Foo, Jia-Nee; Tan, Linda Wei-Lin; Lim, Yenly; Koo, Seok-Hwee; Gan, Linda Seo-Hwee; Cheng, Ching-Yu; Wee, Sharon; Yap, Eric Peng-Huat; Ng, Pauline Crystal; Lim, Wei-Yen; Soong, Richie; Wenk, Markus Rene; Aung, Tin; Wong, Tien-Yin; Khor, Chiea-Chuen; Little, Peter; Chia, Kee-Seng; Teo, Yik-Ying

2013-01-01

Whole-genome sequencing across multiple samples in a population provides an unprecedented opportunity for comprehensively characterizing the polymorphic variants in the population. Although the 1000 Genomes Project (1KGP) has offered brief insights into the value of population-level sequencing, the low coverage has compromised the ability to confidently detect rare and low-frequency variants. In addition, the composition of populations in the 1KGP is not complete, despite the fact that the study design has been extended to more than 2,500 samples from more than 20 population groups. The Malays are one of the Austronesian groups predominantly present in Southeast Asia and Oceania, and the Singapore Sequencing Malay Project (SSMP) aims to perform deep whole-genome sequencing of 100 healthy Malays. By sequencing at a minimum of 30× coverage, we have illustrated the higher sensitivity at detecting low-frequency and rare variants and the ability to investigate the presence of hotspots of functional mutations. Compared to the low-pass sequencing in the 1KGP, the deeper coverage allows more functional variants to be identified for each person. A comparison of the fidelity of genotype imputation of Malays indicated that a population-specific reference panel, such as the SSMP, outperforms a cosmopolitan panel with larger number of individuals for common SNPs. For lower-frequency (<5%) markers, a larger number of individuals might have to be whole-genome sequenced so that the accuracy currently afforded by the 1KGP can be achieved. The SSMP data are expected to be the benchmark for evaluating the value of deep population-level sequencing versus low-pass sequencing, especially in populations that are poorly represented in population-genetics studies. PMID:23290073

Reducing the biases in simulated polar climate by incorporating realistic surface spectral emissivity into the global climate model

NASA Astrophysics Data System (ADS)

Huang, X.; Chen, X.; Flanner, M.; Yang, P.; Feldman, D.; Kuo, C.

2017-12-01

Surface longwave emissivity can be less than unity and vary significantly with frequency. The emissivities of water, ice, and bare land all exhibit different spectral dependence, for both the far-IR and mid-IR bands. However, most climate models still assume blackbody surface in the longwave (LW) radiation scheme of their atmospheric modules. This study incorporates realistic surface spectral emissivity into the RRTMG_LW, the LW radiation scheme in CAM, which is the atmospheric component of the NCAR Community Earth System Model (CESM) version 1.1.1. Then we evaluate its impact on simulated climatology, especially for the polar regions. By ensuring the consistency of the broadband longwave flux across different modules of the CESM, the TOA energy balance in the simulation can be attained without additional tuning of the model. While the impact on global mean surface temperature is small, the surface temperature differences in Polar Regions are statistically significant. The mean surface temperature in Arctic in the modified CESM is 1.5K warmer than that in the standard CESM, reducing the cold bias that the standard CESM has with respect to observations. Accordingly the sea ice fraction in the modified CESM simulation is less than that in the standard CESM simulation by as much as 0.1, which significantly reduces the positive biases in the simulated sea ice coverage by the CESM. The largest sea-ice coverage difference happens in August and September, when new sea ice starts to form. The similar changes can be seen for the simulated Antarctic surface climate as well. In a nutshell, incorporating realistic surface spectral emissivity helps improving the fidelity of simulated surface energy budget in the polar region, which leads to a better simulation of the surface temperature and sea ice coverage.

Project Catch: A space based solution to combat illegal, unreported and unregulated fishing. Part I: Vessel monitoring system

NASA Astrophysics Data System (ADS)

Detsis, Emmanouil; Brodsky, Yuval; Knudtson, Peter; Cuba, Manuel; Fuqua, Heidi; Szalai, Bianca

2012-11-01

Space assets have a unique opportunity to play a more active role in global resource management. There is a clear need to develop resource management tools in a global framework. Illegal, Unregulated and Unreported (IUU) fishing is placing pressure on the health and size of fishing stocks around the world. Earth observation systems can provide fishery management organizations with cost effective monitoring of large swaths of ocean. Project Catch is a fisheries management project based upon the complimentary, but independent Catch-VMS and Catch-GIS systems. Catch-VMS is a Vessel Monitoring System with increased fidelity over existing offerings. Catch-GIS is a Geographical Information System that combines VMS information with existing Earth Observation data and other data sources to identify Illegal, Unregulated and Unreported (IUU) fishing. Project Catch was undertaken by 19 Masters students from the 2010 class of the International Space University. In this paper, the space-based system architecture of Project Catch is presented and analyzed. The rationale for the creation of the system, as well as the engineering trade-off studies in its creation, are discussed. The Catch-VMS proposal was envisaged in order to address two specific problems: (1) the expansion of illegal fishing to high-latitude regions where existing satellite systems coverage is an issue and (2) the lack of coverage in remote oceanic regions due to reliance on coastal-based monitoring. Catch-VMS utilizes ship-borne transponders and hosted-payload receivers on a Global Navigation Satellite System in order to monitor the position and activity of compliant fishing vessels. Coverage is global and continuous with multiple satellites in view providing positional verification through multilateration techniques. The second part of the paper briefly describes the Catch-GIS system and investigates its cost of implementation.

Applications of fidelity measures to complex quantum systems

PubMed Central

2016-01-01

We revisit fidelity as a measure for the stability and the complexity of the quantum motion of single-and many-body systems. Within the context of cold atoms, we present an overview of applications of two fidelities, which we call static and dynamical fidelity, respectively. The static fidelity applies to quantum problems which can be diagonalized since it is defined via the eigenfunctions. In particular, we show that the static fidelity is a highly effective practical detector of avoided crossings characterizing the complexity of the systems and their evolutions. The dynamical fidelity is defined via the time-dependent wave functions. Focusing on the quantum kicked rotor system, we highlight a few practical applications of fidelity measurements in order to better understand the large variety of dynamical regimes of this paradigm of a low-dimensional system with mixed regular–chaotic phase space. PMID:27140967

Feasibility and fidelity of practising surgical fixation on a virtual ulna bone

PubMed Central

LeBlanc, Justin; Hutchison, Carol; Hu, Yaoping; Donnon, Tyrone

2013-01-01

Background Surgical simulators provide a safe environment to learn and practise psychomotor skills. A goal for these simulators is to achieve high levels of fidelity. The purpose of this study was to develop a reliable surgical simulator fidelity questionnaire and to assess whether a newly developed virtual haptic simulator for fixation of an ulna has comparable levels of fidelity as Sawbones. Methods Simulator fidelity questionnaires were developed. We performed a stratified randomized study with surgical trainees. They performed fixation of the ulna using a virtual simulator and Sawbones. They completed the fidelity questionnaires after each procedure. Results Twenty-two trainees participated in the study. The reliability of the fidelity questionnaire for each separate domain (environment, equipment, psychological) was Cronbach α greater than 0.70, except for virtual environment. The Sawbones had significantly higher levels of fidelity than the virtual simulator (p < 0.001) with a large effect size difference (Cohen d < 1.3). Conclusion The newly developed fidelity questionnaire is a reliable tool that can potentially be used to determine the fidelity of other surgical simulators. Increasing the fidelity of this virtual simulator is required before its use as a training tool for surgical fixation. The virtual simulator brings with it the added benefits of repeated, independent safe use with immediate, objective feedback and the potential to alter the complexity of the skill. PMID:23883510

Solid-state reaction of iron on β-SiC

NASA Astrophysics Data System (ADS)

Kaplan, R.; Klein, P. H.; Addamiano, A.

1985-07-01

The solid-state reaction between Fe and β-SiC has been studied using Auger-electron and electron-energy-loss spectroscopies and ion sputter profiling. Fe films from submonolayer coverage to 1000 Å thickness were grown in ultrahigh vacuum, and annealed at temperatures up to 550 °C. Auger line-shape changes occurred even for initial Fe coverage at 190 °C, indicating substantial bond alteration in the SiC substrate. A 1000-Å film was largely consumed by reaction with Si and C diffused from the substrate during a 500 °C anneal, and exhibited both Fe silicide and carbide throughout most of its original volume and free C present as graphite primarily at the surface. As an aid in identifying the reaction products studied in this work, Auger line shapes were first determined for the SiLVV peak in Fe silicide and for the CKLL transition in Fe carbide.

Fidelity to the housing first model and effectiveness of permanent supported housing programs in California.

PubMed

Gilmer, Todd P; Stefancic, Ana; Katz, Marian L; Sklar, Marisa; Tsemberis, Sam; Palinkas, Lawrence A

2014-11-01

Permanent supported housing programs are being implemented throughout the United States. This study examined the relationship between fidelity to the Housing First model and residential outcomes among clients of full service partnerships (FSPs) in California. This study had a mixed-methods design. Quantitative administrative and survey data were used to describe FSP practices and to examine the association between fidelity to Housing First and residential outcomes in the year before and after enrollment of 6,584 FSP clients in 86 programs. Focus groups at 20 FSPs provided qualitative data to enhance the understanding of these findings with actual accounts of housing-related experiences in high- and low-fidelity programs. Prior to enrollment, the mean days of homelessness were greater at high- versus low-fidelity (101 versus 46 days) FSPs. After adjustment for individual characteristics, the analysis found that days spent homeless after enrollment declined by 87 at high-fidelity programs and by 34 at low-fidelity programs. After adjustment for days spent homeless before enrollment, days spent homeless after enrollment declined by 63 at high-fidelity programs and by 53 at low-fidelity programs. After enrollment, clients at high-fidelity programs spent more than 60 additional days in apartments than clients at low-facility programs. Differences were found between high- and low-fidelity FSPs in client choice in housing and how much clients' goals were considered in housing placement. Programs with greater fidelity to the Housing First model enrolled clients with longer histories of homelessness and placed most of them in apartments.

Achieving Global Ocean Color Climate Data Records

NASA Technical Reports Server (NTRS)

Franz, Bryan

2010-01-01

Ocean color, or the spectral distribution of visible light upwelling from beneath the ocean surface, carries information on the composition and concentration of biological constituents within the water column. The CZCS mission in 1978 demonstrated that quantitative ocean color measurements could be. made from spaceborne sensors, given sufficient corrections for atmospheric effects and a rigorous calibration and validation program. The launch of SeaWiFS in 1997 represents the beginning of NASA's ongoing efforts to develop a continuous ocean color data record with sufficient coverage and fidelity for global change research. Achievements in establishing and maintaining the consistency of the time-series through multiple missions and varying instrument designs will be highlighted in this talk, including measurements from NASA'S MODIS instruments currently flying on the Terra and Aqua platforms, as well as the MERIS sensor flown by ESA and the OCM-2 sensor recently launched by ISRO.

78 FR 43231 - Agency Information Collection Activities: Submission to OMB for Reinstatement, Without Change, of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

...The NCUA intends to submit the following information collection to the Office of Management and Budget (OMB) for review and clearance under the Paperwork Reduction Act of 1995 (Pub. L. 104-13, 44 U.S.C. Chapter 35). This information collection relates to 12 CFR part 713 which requires a federal credit union (FCU) to monitor its eligibility to qualify for a higher fidelity coverage deductible and to notify the NCUA if its financial condition changes resulting in the loss of that eligibility for the higher deductible. This information collection notice is published to obtain comments from the public. This requirement enables NCUA to monitor the FCU's financial condition for safety and soundness purposes and helps to assure that FCUs are properly and adequately protected against potential losses due to insider abuse such as fraud and embezzlement.

Mechanical Properties of a vdW molecular monolayer at a metal surface: Structural Polymorphism leading to facile compression

NASA Astrophysics Data System (ADS)

Sun, Dezheng; Kim, Daeho; Le, Duy; Borck, Øyvind; Berland, Kristian; Kim, Kwangmoo; Lu, Wenhao; Zhu, Yeming; Luo, Miaomiao; Wyrick, Jon; Cheng, Zhihai; Einstein, T. L.; Rahman, Talat; Hyldgaard, Per; Bartels, Ludwig

2011-03-01

Intermolecular force plays an important role in self-assembly and surface pattern formation. Anthracene and similar unsubstituted arenes attach to a metallic substrate predominantly through van der Waals interaction leading. In this contribution we present images how anthracene on Cu(111) forms a large number of highly ordered patterns that feature a broad array of structural motifs. Density functional theory modeling including vdW interactions allows us to model the energetic of the pattern formation at high fidelity. Moreover, it allows us to deduce the strain energy associated with films of varying coverage. From this work, we obtain the Young's modulus and Poisson Ratio of a molecular monolayer, which resemble properties conventionally found for porous materials. These patterns are in marked contrast to those found after introduction of functional groups in the molecules, such as carbonyls or thiols.

Walking peptide on Au(110) surface: Origin and nature of interfacial process

NASA Astrophysics Data System (ADS)

Humblot, V.; Tejeda, A.; Landoulsi, J.; Vallée, A.; Naitabdi, A.; Taleb, A.; Pradier, C.-M.

2014-10-01

IGF tri-peptide adsorption on Au(110)-(1 × 2) under Ultra High Vacuum (UHV) conditions has been investigated using surface science techniques such as synchrotron based Angle Resolved X-ray Photoemission Spectroscopy (AR-PES or AR-XPS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM). The behaviour of IGF molecules has been revealed to be coverage dependent; at low coverage, there is formation of islands presenting a chiral self-organised molecular network with a (4 2, - 3 2) symmetry as shown by Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) on the unaltered Au(110)-(1 × 2) reconstruction, suggesting significant intermolecular interactions. When the coverage is increased, the islands grow bigger, and one can observe the disappearance of the self-organised network, along with a remarkable destruction of the (1 × 2) substrate reconstruction, as shown by STM. The effect of IGF on the surface gold atoms has been further confirmed by angle-resolved photoemission measurements which suggest a modification of the electronic states with the (1 × 2) symmetry. The resulting molecular organisation, and overall the gold surface disorganisation, prove a strong surface-molecule interaction, which may be probably be explained by a covalent bonding.

Surface hydrogenation regulated wrinkling and torque capability of hydrogenated graphene annulus under circular shearing.

PubMed

Li, Yinfeng; Liu, Silin; Datta, Dibakar; Li, Zhonghua

2015-11-12

Wrinkles as intrinsic topological feature have been expected to affect the electrical and mechanical properties of atomically thin graphene. Molecular dynamics simulations are adopted to investigate the wrinkling characteristics in hydrogenated graphene annulus under circular shearing at the inner edge. The amplitude of wrinkles induced by in-plane rotation around the inner edge is sensitive to hydrogenation, and increases quadratically with hydrogen coverage. The effect of hydrogenation on mechanical properties is investigated by calculating the torque capability of annular graphene with varying hydrogen coverage and inner radius. Hydrogenation-enhanced wrinkles cause the aggregation of carbon atoms towards the inner edge and contribute to the critical torque strength of annulus. Based on detailed stress distribution contours, a shear-to-tension conversion mechanism is proposed for the contribution of wrinkles on torque capacity. As a result, the graphane annulus anomalously has similar torque capacity to pristine graphene annulus. The competition between hydrogenation caused bond strength deterioration and wrinkling induced local stress state conversion leads to a U-shaped evolution of torque strength relative to the increase of hydrogen coverage from 0 to 100%. Such hydrogenation tailored topological and mechanical characteristics provides an innovative mean to develop novel graphene-based devices.

Tuning surface grafting density of CeO2 nanocrystals with near- and supercritical solvent characteristics.

PubMed

Giroire, B; Slostowski, C; Marre, S; Aymonier, C; Aida, T; Hojo, D; Aoki, N; Takami, S; Adschiri, T

2016-01-21

In this work, the solvent effect on the synthesis of CeO2 nanocrystals synthesized in near- and supercritical alcohols is discussed. The materials prepared displayed a unique morphology of small nanocrystals (<10 nm) aggregated into larger nanospheres (∼100-200 nm). In such syntheses, alcohol molecules directly interact with the nanocrystal surface through alkoxide and carboxylate bondings. The grafting density was quantified from the weight loss measured using thermogravimetric analysis. A direct correlation between the grafting density and the alcohol chain length can be established. It was demonstrated that the shorter the alcohol chain length (i.e. methanol), the higher the surface coverage is. This trend is independent of the synthesis mode (batch or continuous). Additionally, an influence of the grafting density on the resulting nanocrystal size was established. It is suggested that the surface coverage has a high influence on the early stages of the nucleation and growth. Indeed, when high surface coverages are reached, all surface active sites are blocked, limiting the growth step and therefore leading to smaller particles. This effect was noticed with the materials prepared in the continuous mode where shorter reaction time was performed.

Implementation Fidelity in Community-Based Interventions

PubMed Central

Breitenstein, Susan M.; Gross, Deborah; Garvey, Christine; Hill, Carri; Fogg, Louis; Resnick, Barbara

2012-01-01

Implementation fidelity is the degree to which an intervention is delivered as intended and is critical to successful translation of evidence-based interventions into practice. Diminished fidelity may be why interventions that work well in highly controlled trials may fail to yield the same outcomes when applied in real life contexts. The purpose of this paper is to define implementation fidelity and describe its importance for the larger science of implementation, discuss data collection methods and current efforts in measuring implementation fidelity in community-based prevention interventions, and present future research directions for measuring implementation fidelity that will advance implementation science. PMID:20198637

The effect of contextual sound cues on visual fidelity perception.

PubMed

Rojas, David; Cowan, Brent; Kapralos, Bill; Collins, Karen; Dubrowski, Adam

2014-01-01

Previous work has shown that sound can affect the perception of visual fidelity. Here we build upon this previous work by examining the effect of contextual sound cues (i.e., sounds that are related to the visuals) on visual fidelity perception. Results suggest that contextual sound cues do influence visual fidelity perception and, more specifically, our perception of visual fidelity increases with contextual sound cues. These results have implications for designers of multimodal virtual worlds and serious games that, with the appropriate use of contextual sounds, can reduce visual rendering requirements without a corresponding decrease in the perception of visual fidelity.

Monitoring intervention fidelity of a lifestyle behavioral intervention delivered through telehealth

PubMed Central

Sineath, Ashley; Lambert, Lauren; Verga, Catherine; Wagstaff, Miranda

2017-01-01

Background Technology-based lifestyle behavioral interventions (i.e., telehealth, mHealth, eHealth, and/or digital health) are becoming an alternative standard of care and possess several advantages over traditional clinical settings such as convenience, cost, and the ability to tailor plans and feedback to a participant’s individual needs. These technology-based interventions also present unique challenges to intervention fidelity due to extra elements involved in executing the intervention. Intervention fidelity monitoring is essential to ensure internal and external validity, yet the development and utilization of fidelity protocols is under-reported in the literature. The purpose of this paper is to describe the intervention fidelity protocol for the 24-START study, a behavior change intervention delivered through telephone and internet. This paper also discusses the results of a pilot audit conducted to determine the feasibility of monitoring adherence to the fidelity protocol. Methods The 24-START fidelity protocol was developed in accordance with the five fidelity areas outlined by the NIH Behavior Change Consortium (NIH BCC) including: design of study, provider training, delivery of treatment, receipt of treatment, and enactment of treatment. The fidelity strategies provided by the NIH BCC in each area were tailored to fit the specific design of the 24-START study. Twenty-six total fidelity strategies were developed in accordance with the five areas and a corresponding fidelity monitoring plan was created. Because these strategies are only beneficial if implemented, the fidelity monitoring plan was developed to ensure the fidelity strategies are consistently implemented over the course of the intervention. Results A pilot audit of nine participant files was conducted to test the feasibility of the fidelity protocol developed. Out of the nine participant files reviewed, 89% of scheduled phone calls between a telehealth coach and participant were successfully completed. Of the completed calls, telehealth coaches delivered the intervention as intended 85.3% of the time, and 74% of planned secondary contacts made through the internet were delivered successfully. Additionally, between treatment group dosing was found to be equal. Several weak areas in the fidelity protocol were identified for improvement. The results were satisfactory and the audit was deemed feasible for ongoing use. Conclusions The NIH BCC provides a valuable framework for telehealth interventions to develop fidelity protocols ultimately contributing to improved internal and external validity, better translation of results, increased transparency, and increased opportunities for replication within the field. The 24-START pilot audit found the fidelity protocol efficacious and feasible while also identifying areas of weakness in need of revision. The refined protocol will continue to be utilized throughout the data collection phase. Future telehealth interventions should develop and disclose fidelity protocols to improve the overall quality and standard of telehealth interventions. PMID:28894745

Monitoring intervention fidelity of a lifestyle behavioral intervention delivered through telehealth.

PubMed

Sineath, Ashley; Lambert, Lauren; Verga, Catherine; Wagstaff, Miranda; Wingo, Brooks C

2017-01-01

Technology-based lifestyle behavioral interventions (i.e., telehealth, mHealth, eHealth, and/or digital health) are becoming an alternative standard of care and possess several advantages over traditional clinical settings such as convenience, cost, and the ability to tailor plans and feedback to a participant's individual needs. These technology-based interventions also present unique challenges to intervention fidelity due to extra elements involved in executing the intervention. Intervention fidelity monitoring is essential to ensure internal and external validity, yet the development and utilization of fidelity protocols is under-reported in the literature. The purpose of this paper is to describe the intervention fidelity protocol for the 24-START study, a behavior change intervention delivered through telephone and internet. This paper also discusses the results of a pilot audit conducted to determine the feasibility of monitoring adherence to the fidelity protocol. The 24-START fidelity protocol was developed in accordance with the five fidelity areas outlined by the NIH Behavior Change Consortium (NIH BCC) including: design of study, provider training, delivery of treatment, receipt of treatment, and enactment of treatment. The fidelity strategies provided by the NIH BCC in each area were tailored to fit the specific design of the 24-START study. Twenty-six total fidelity strategies were developed in accordance with the five areas and a corresponding fidelity monitoring plan was created. Because these strategies are only beneficial if implemented, the fidelity monitoring plan was developed to ensure the fidelity strategies are consistently implemented over the course of the intervention. A pilot audit of nine participant files was conducted to test the feasibility of the fidelity protocol developed. Out of the nine participant files reviewed, 89% of scheduled phone calls between a telehealth coach and participant were successfully completed. Of the completed calls, telehealth coaches delivered the intervention as intended 85.3% of the time, and 74% of planned secondary contacts made through the internet were delivered successfully. Additionally, between treatment group dosing was found to be equal. Several weak areas in the fidelity protocol were identified for improvement. The results were satisfactory and the audit was deemed feasible for ongoing use. The NIH BCC provides a valuable framework for telehealth interventions to develop fidelity protocols ultimately contributing to improved internal and external validity, better translation of results, increased transparency, and increased opportunities for replication within the field. The 24-START pilot audit found the fidelity protocol efficacious and feasible while also identifying areas of weakness in need of revision. The refined protocol will continue to be utilized throughout the data collection phase. Future telehealth interventions should develop and disclose fidelity protocols to improve the overall quality and standard of telehealth interventions.

Interaction of acetonitrile with the surfaces of amorphous and crystalline ice

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

Schaff, J.E.; Roberts, J.T.

1999-10-12

The adsorption of acetonitrile (CH{sub 3}CN) on ultrathin films of ice under ultrahigh vacuum was investigated with temperature-programmed desorption ass spectrometry (TPD) and Fourier transform infrared reflection absorption spectroscopy (FTIRAS). Two types of film were studied, amorphous and crystalline. On the amorphous films, two sates of adsorbed acetonitrile were observed by TPD and FTIRAS. One of the states is attributed to acetonitrile that is hydrogen bonded to agree OH group at the ice surface; the other state is assigned to acetonitrile that is purely physiorbed. Evidence for the hydrogen-bonded state is two-fold. First, there is a large kinetic isotope effectmore » for desorption from H{sub 2}O-and D{sub 2}O-ice: the desorption temperatures from ice-h{sub 2} and ice-d{sub 2} are {approximately}161 and {approximately}176 K, respectively. Second, the C{triple{underscore}bond}N stretching frequency (2,265 cm{sup {minus}1}) is 16 cm{sup {minus}1} is greater than that of physisorbed acetonitrile, and it is roughly equal to that of acetonitrile which is hydrogen bonded to an OH group at the air-liquid water interface. On the crystalline films, there is no evidence for a hydrogen-bonded state in the TPD spectra. The FTIRAS spectra do show that some hydrogen-bonded acetonitrile is present but at a maximum coverage that is roughly one-sixth of that on the amorphous surface. The difference between the amorphous and crystalline surfaces cannot be attributed to a difference n surface areas. Rather, this work provides additional evidence that the surface chemical properties of amorphous ice are different from those of crystalline ice.« less

Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes

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

Rodriguez, J.A.; Liu, P.; Takahashi, Y.

2011-05-30

Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au andmore » the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.« less

Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes

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

J Rodriguez; P Liu; Y Takahashi

2011-12-31

Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au andmore » the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.« less

An intervention fidelity framework for technology-based behavioral interventions.

PubMed

Devito Dabbs, Annette; Song, Mi-Kyung; Hawkins, Robert; Aubrecht, Jill; Kovach, Karen; Terhorst, Lauren; Connolly, Mary; McNulty, Mary; Callan, Judith

2011-01-01

Despite the proliferation of health technologies, descriptions of the unique considerations and practical guidance for evaluating the intervention fidelity of technology-based behavioral interventions are lacking. The aims of this study were to (a) discuss how technology-based behavioral interventions challenge conventions about how intervention fidelity is conceptualized and evaluated, (b) propose an intervention fidelity framework that may be more appropriate for technology-based behavioral interventions, and (c) present a plan for operationalizing each concept in the framework using the intervention fidelity monitoring plan for Pocket PATH (Personal Assistant for Tracking Health), a mobile health technology designed to promote self-care behaviors after lung transplantation, as an exemplar. The literature related to intervention fidelity and technology acceptance was used to identify the issues that are unique to the fidelity of technology-based behavioral interventions and thus important to include in a proposed intervention fidelity framework. An intervention fidelity monitoring plan for technology-based behavioral interventions was developed as an example. The intervention fidelity monitoring plan was deemed feasible and practical to implement and showed utility in operationalizing the concepts such as assessing interventionists' delivery and participants' acceptance of the technology-based behavioral intervention. The framework has the potential to guide the development of implementation fidelity monitoring tools for other technology-based behavioral interventions. Further application and testing of this framework will allow for a better understanding of the role that technology acceptance plays in the adoption and enactment of the behaviors that technology-based behavioral interventions are intended to promote.

Intervention Fidelity and Facilitator Training.

PubMed

Rew, Lynn; Banner, Matthew; Johnson, Karen; Slesnick, Natasha

2018-01-01

Intervention fidelity is an ongoing concern for rigorous research, from the initial stages of planning and study design to the maintenance of internal validity. An added concern is the balance between fidelity and design accommodation to better suit varied populations and individuals. In this article, we describe our process for monitoring intervention fidelity during an individualized, yet standardized, strengths-based intervention with homeless youths, in which we include periodic training of our professional intervention facilitators. In our ongoing study, which is based on a Solomon four-group design with repeated measures, monitoring and training are essential to ensure intervention fidelity. Despite a rich literature about intervention fidelity, little guidance is available to help researchers and practitioners implement fidelity strategies in the real world with vulnerable populations. This article addresses this gap.

Fidelity Moderates the Association Between Negative Condom Attitudes and Outcome Behavior in an Evidence-Based Sexual Risk Reduction Intervention for Female Sex Workers.

PubMed

Pitpitan, Eileen V; Chavarin, Claudia V; Semple, Shirley J; Mendoza, Doroteo; Rodriguez, Carlos Magis; Staines, Hugo; Aarons, Gregory A; Patterson, Thomas L

2017-06-01

Intervention fidelity and participant-level variables, such as negative attitudes towards condoms, are important variables to consider in the successful implementation of evidence-based HIV prevention interventions. Mujer Segura is an intervention that has been shown to be efficacious at reducing condomless sex for female sex workers (FSWs) in Mexico [1]. We examined main effects of fidelity, negative condom attitudes, and their interaction on the effectiveness of the Mujer Segura intervention at reducing condomless sex at intervention follow-up. Of the FSWs recruited from 13 cities across Mexico, 528 participated in the Mujer Segura intervention. We measured negative condom attitudes at baseline (comprising of beliefs and outcome evaluations) and condomless sex with clients at baseline and 6-month follow-up. Fidelity was measured by a fidelity checklist completed by independent raters; the sum of potentially 43 total elements completed by the counselor constituted fidelity. Complete fidelity was found in only 15.1% (n = 73) of sessions. There was no significant main effect of intervention fidelity on condomless sex with clients at follow-up. There was a significant and positive main effect of negative condom attitudes and a significant two-way interaction. At lower levels of fidelity, negative condom attitudes predicted greater condomless sex acts, whereas at higher levels of fidelity, the effect of condom attitudes became weaker. The results also indicated that the interaction between negative condom attitudes and fidelity were driven primarily by negative condom beliefs, as opposed to negative condom outcome evaluations. Ensuring treatment fidelity in an HIV prevention intervention is particularly important when participants have negative attitudes towards condoms.

High Versus Low Theoretical Fidelity Pedometer Intervention Using Social-Cognitive Theory on Steps and Self-Efficacy.

PubMed

Raedeke, Thomas D; Dlugonski, Deirdre

2017-12-01

This study was designed to compare a low versus high theoretical fidelity pedometer intervention applying social-cognitive theory on step counts and self-efficacy. Fifty-six public university employees participated in a 10-week randomized controlled trial with 2 conditions that varied in theoretical fidelity. Participants in the high theoretical fidelity condition wore a pedometer and participated in a weekly group walk followed by a meeting to discuss cognitive-behavioral strategies targeting self-efficacy. Participants in the low theoretical fidelity condition met for a group walk and also used a pedometer as a motivational tool and to monitor steps. Step counts were assessed throughout the 10-week intervention and after a no-treatment follow-up (20 weeks and 30 weeks). Self-efficacy was measured preintervention and postintervention. Participants in the high theoretical fidelity condition increased daily steps by 2,283 from preintervention to postintervention, whereas participants in the low fidelity condition demonstrated minimal change during the same time period (p = .002). Individuals attending at least 80% of the sessions in the high theoretical fidelity condition showed an increase of 3,217 daily steps (d = 1.03), whereas low attenders increased by 925 (d = 0.40). Attendance had minimal impact in the low theoretical fidelity condition. Follow-up data revealed that step counts were at least somewhat maintained. For self-efficacy, participants in the high, compared with those in the low, theoretical fidelity condition showed greater improvements. Findings highlight the importance of basing activity promotion efforts on theory. The high theoretical fidelity intervention that included cognitive-behavioral strategies targeting self-efficacy was more effective than the low theoretical fidelity intervention, especially for those with high attendance.

Contra-Thermodynamic, Photocatalytic E→Z Isomerization of Styrenyl Boron Species: Vectors to Facilitate Exploration of Two-Dimensional Chemical Space.

PubMed

Molloy, John J; Metternich, Jan B; Daniliuc, Constantin G; Watson, Allan J B; Gilmour, Ryan

2018-03-12

Designing strategies to access stereodefined olefinic organoboron species is an important synthetic challenge. Despite significant advances, there is a striking paucity of routes to Z-α-substituted styrenyl organoborons. Herein, this strategic imbalance is redressed by exploiting the polarity of the C(sp 2 )-B bond to activate the neighboring π system, thus enabling a mild, traceless photocatalytic isomerization of readily accessible E-α-substituted styrenyl BPins to generate the corresponding Z-isomers with high fidelity. Preliminary validation of this contra-thermodynamic E→Z isomerization is demonstrated in a series of stereoretentive transformations to generate Z-configured trisubstituted alkenes, as well as in a concise synthesis of the anti-tumor agent Combretastatin A4. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monolithic solid-state lasers for spaceflight

NASA Astrophysics Data System (ADS)

Krainak, Michael A.; Yu, Anthony W.; Stephen, Mark A.; Merritt, Scott; Glebov, Leonid; Glebova, Larissa; Ryasnyanskiy, Aleksandr; Smirnov, Vadim; Mu, Xiaodong; Meissner, Stephanie; Meissner, Helmuth

2015-02-01

A new solution for building high power, solid state lasers for space flight is to fabricate the whole laser resonator in a single (monolithic) structure or alternatively to build a contiguous diffusion bonded or welded structure. Monolithic lasers provide numerous advantages for space flight solid-state lasers by minimizing misalignment concerns. The closed cavity is immune to contamination. The number of components is minimized thus increasing reliability. Bragg mirrors serve as the high reflector and output coupler thus minimizing optical coatings and coating damage. The Bragg mirrors also provide spectral and spatial mode selection for high fidelity. The monolithic structure allows short cavities resulting in short pulses. Passive saturable absorber Q-switches provide a soft aperture for spatial mode filtering and improved pointing stability. We will review our recent commercial and in-house developments toward fully monolithic solid-state lasers.

Validation of the Standard Mobility Application Programming Interface Fidelity 1 and 2

DTIC Science & Technology

2006-07-01

Cross-Country, Dry) 16000-fl 14000 12000- O- U 00 - ielt 0 0 Fidelity2 %0 10000 8000- 4000-zo-- Over Even Under N Fidelity 1 8151 14224 4553 0...Road, Snow) 90% 70% -j S60% > 50% ~40% E 30% S20% 1 0% - ielt 0% 0 5 10 15 20 STNDMob - NRMM (rriph) Figure 57. M923/M200A1 Fidelity 1 vs. Fidelity 2

Superconducting Vacuum-Gap Crossovers for High Performance Microwave Applications

NASA Technical Reports Server (NTRS)

Denis, Kevin L.; Brown, Ari D.; Chang, Meng-Ping; Hu, Ron; U-Yen, Kongpop; Wollack, Edward J.

2016-01-01

The design and fabrication of low-loss wide-bandwidth superconducting vacuum-gap crossovers for high performance millimeter wave applications are described. In order to reduce ohmic and parasitic losses at millimeter wavelengths a vacuum gap is preferred relative to dielectric spacer. Here, vacuum-gap crossovers were realized by using a sacrificial polymer layer followed by niobium sputter deposition optimized for coating coverage over an underlying niobium signal layer. Both coplanar waveguide and microstrip crossover topologies have been explored in detail. The resulting fabrication process is compatible with a bulk micro-machining process for realizing waveguide coupled detectors, which includes sacrificial wax bonding, and wafer backside deep reactive ion etching for creation of leg isolated silicon membrane structures. Release of the vacuum gap structures along with the wax bonded wafer after DRIE is implemented in the same process step used to complete the detector fabrication. ?

Automated Generation and Assessment of Autonomous Systems Test Cases

NASA Technical Reports Server (NTRS)

Barltrop, Kevin J.; Friberg, Kenneth H.; Horvath, Gregory A.

2008-01-01

This slide presentation reviews some of the issues concerning verification and validation testing of autonomous spacecraft routinely culminates in the exploration of anomalous or faulted mission-like scenarios using the work involved during the Dawn mission's tests as examples. Prioritizing which scenarios to develop usually comes down to focusing on the most vulnerable areas and ensuring the best return on investment of test time. Rules-of-thumb strategies often come into play, such as injecting applicable anomalies prior to, during, and after system state changes; or, creating cases that ensure good safety-net algorithm coverage. Although experience and judgment in test selection can lead to high levels of confidence about the majority of a system's autonomy, it's likely that important test cases are overlooked. One method to fill in potential test coverage gaps is to automatically generate and execute test cases using algorithms that ensure desirable properties about the coverage. For example, generate cases for all possible fault monitors, and across all state change boundaries. Of course, the scope of coverage is determined by the test environment capabilities, where a faster-than-real-time, high-fidelity, software-only simulation would allow the broadest coverage. Even real-time systems that can be replicated and run in parallel, and that have reliable set-up and operations features provide an excellent resource for automated testing. Making detailed predictions for the outcome of such tests can be difficult, and when algorithmic means are employed to produce hundreds or even thousands of cases, generating predicts individually is impractical, and generating predicts with tools requires executable models of the design and environment that themselves require a complete test program. Therefore, evaluating the results of large number of mission scenario tests poses special challenges. A good approach to address this problem is to automatically score the results based on a range of metrics. Although the specific means of scoring depends highly on the application, the use of formal scoring - metrics has high value in identifying and prioritizing anomalies, and in presenting an overall picture of the state of the test program. In this paper we present a case study based on automatic generation and assessment of faulted test runs for the Dawn mission, and discuss its role in optimizing the allocation of resources for completing the test program.

Further Validation of the Pathways Housing First Fidelity Scale.

PubMed

Goering, Paula; Veldhuizen, Scott; Nelson, Geoffrey B; Stefancic, Ana; Tsemberis, Sam; Adair, Carol E; Distasio, Jino; Aubry, Tim; Stergiopoulos, Vicky; Streiner, David L

2016-01-01

This study examined whether Housing First fidelity ratings correspond to program operation descriptions from administrative data and predict client outcomes. A multisite, randomized controlled trial (At Home/Chez Soi) in five Canadian cities included two assessments of 12 programs over two years. Outcomes for 1,158 clients were measured every six months. Associations between fidelity ratings and administrative data (Spearman correlations) and participant outcomes (mixed-effects modeling) were examined. Fidelity ratings were generally good (mean ± SD=136.6 ± 10.3 out of a possible range of 38-152; 87% of maximum value). Fidelity was significantly associated with three of four measures of program operation, with correlations between .55 and .60. Greater program fidelity was associated with improvement in housing stability, community functioning, and quality of life. Variation in program fidelity was associated with operations and outcomes, supporting scale validity and intervention effectiveness. These findings reinforced the value of using fidelity monitoring to conduct quality assurance and technical assistance activities.

Passivation of InGaAs(001)-(2 × 4) by Self-Limiting Chemical Vapor Deposition of a Silicon Hydride Control Layer.

PubMed

Edmonds, Mary; Kent, Tyler; Chagarov, Evgueni; Sardashti, Kasra; Droopad, Ravi; Chang, Mei; Kachian, Jessica; Park, Jun Hong; Kummel, Andrew

2015-07-08

A saturated Si-Hx seed layer for gate oxide or contact conductor ALD has been deposited via two separate self-limiting and saturating CVD processes on InGaAs(001)-(2 × 4) at substrate temperatures of 250 and 350 °C. For the first self-limiting process, a single silicon precursor, Si3H8, was dosed at a substrate temperature of 250 °C, and XPS results show the deposited silicon hydride layer saturated at about 4 monolayers of silicon coverage with hydrogen termination. STS results show the surface Fermi level remains unpinned following the deposition of the saturated silicon hydride layer, indicating the InGaAs surface dangling bonds are electrically passivated by Si-Hx. For the second self-limiting process, Si2Cl6 was dosed at a substrate temperature of 350 °C, and XPS results show the deposited silicon chloride layer saturated at about 2.5 monolayers of silicon coverage with chlorine termination. Atomic hydrogen produced by a thermal gas cracker was subsequently dosed at 350 °C to remove the Si-Cl termination by replacing with Si-H termination as confirmed by XPS, and STS results confirm the saturated Si-Hx bilayer leaves the InGaAs(001)-(2 × 4) surface Fermi level unpinned. Density function theory modeling of silicon hydride surface passivation shows an Si-Hx monolayer can remove all the dangling bonds and leave a charge balanced surface on InGaAs.

Early stages of epitaxial CoSi 2 formation on Si(111) surface as investigated by ARUPS, XPS, LEED and work function variation

NASA Astrophysics Data System (ADS)

Pirri, C.; Peruchetti, J. C.; Gewinner, G.; Derrien, J.

1985-04-01

We performed the CoSi 2 formation on a clean (7 × 7) Si(111) surface under UHV conditions. The used techniques were angle resolved UV photoemission, X-ray photoemission, work function change and low energy electron diffraction in order to study the electronic and structural properties of the interface during its formation. At room temperature, a small amount of Co reacts strongly with Si to form an interfacial and very thin cobalt suicide. The ultraviolet photoelectron spectrum displays already two features corresponding respectively to the Co 3d and Si 3p electron bonding states and the Co 3d non-bonding states. With increasing coverage ( θ ≳ 4 ML) it seems that the interfacial suicide prevents further Co-Si interdiffusion to achieve the suicide reaction and a metal rich film is found. At high temperature (˜ 600°C) and in the first monolayer range, several superstructures are found (√7 × √7, and 2 × 2). They are induced by a Co-Si bidimensional compound where the Co atoms are not yet completely surrounded by Si atoms as in their bulk CoSi 2 structure. With increasing coverage, a CoSi 2-like photoemission spectrum is observed reflecting the formation of the disilicide. The LEED pattern testifies an epitaxial growth displaying a (1 × 1) CoSi 2 diagram. The work function change technique also reflects faithfully this growth.

Using mixed methods to assess fidelity of delivery and its influencing factors in a complex self-management intervention for people with osteoarthritis and low back pain.

PubMed

Toomey, Elaine; Matthews, James; Hurley, Deirdre A

2017-08-04

Despite an increasing awareness of the importance of fidelity of delivery within complex behaviour change interventions, it is often poorly assessed. This mixed methods study aimed to establish the fidelity of delivery of a complex self-management intervention and explore the reasons for these findings using a convergent/triangulation design. Feasibility trial of the Self-management of Osteoarthritis and Low back pain through Activity and Skills (SOLAS) intervention (ISRCTN49875385), delivered in primary care physiotherapy. 60 SOLAS sessions were delivered across seven sites by nine physiotherapists. Fidelity of delivery of prespecified intervention components was evaluated using (1) audio-recordings (n=60), direct observations (n=24) and self-report checklists (n=60) and (2) individual interviews with physiotherapists (n=9). Quantitatively, fidelity scores were calculated using percentage means and SD of components delivered. Associations between fidelity scores and physiotherapist variables were analysed using Spearman's correlations. Interviews were analysed using thematic analysis to explore potential reasons for fidelity scores. Integration of quantitative and qualitative data occurred at an interpretation level using triangulation. Quantitatively, fidelity scores were high for all assessment methods; with self-report (92.7%) consistently higher than direct observations (82.7%) or audio-recordings (81.7%). There was significant variation between physiotherapists' individual scores (69.8% - 100%). Both qualitative and quantitative data (from physiotherapist variables) found that physiotherapists' knowledge (Spearman's association at p=0.003) and previous experience (p=0.008) were factors that influenced their fidelity. The qualitative data also postulated participant-level (eg, individual needs) and programme-level factors (eg, resources) as additional elements that influenced fidelity. The intervention was delivered with high fidelity. This study contributes to the limited evidence regarding fidelity assessment methods within complex behaviour change interventions. The findings suggest a combination of quantitative methods is suitable for the assessment of fidelity of delivery. A mixed methods approach provided a more insightful understanding of fidelity and its influencing factors. ISRCTN49875385; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Site fidelity, territory fidelity, and natal philopatry in Willow Flycatchers (Empidonax traillii)

USGS Publications Warehouse

Sedgwick, James A.

2004-01-01

I investigated the causes and consequences of adult breeding-site fidelity, territory fidelity, and natal philopatry in Willow Flycatchers (Empidonax traillii) in southeastern Oregon over a 10-year period, testing the general hypothesis that fidelity and dispersal distances are influenced by previous breeding performance. Willow Flycatchers adhered to the generally observed tendencies of passerine birds for low natal philopatry and high breedingsite fidelity. Site fidelity (return to the study area) of adult males (52.0%) and females (51.3%), and median dispersal distances between seasons (16 m vs. 19 m) were similar. Previous breeding performance and residency (age-experience), but not study-site quality, explained site fidelity in females. Site fidelity of females rearing 4–5 young (64.4%) exceeded that of unsuccessful females (40.0%), breeding dispersal was less (successful: 15 m; unsuccessful: 33 m), and novice residents were more site-faithful than former residents. Probability of site fidelity was higher for previously successful females (odds ratio = 4.76), those with greater seasonal fecundity (odds ratio = 1.58), novice residents (odds ratio = 1.41), and unparasitized females (odds ratio = 2.76). Male site fidelity was not related to residency, site quality, or previous breeding performance. Territory fidelity (return to the previous territory) in females was best explained by previous breeding performance, but not by site quality or residency. Previously successful females were more likely to return to their territory of the previous season than either unsuccessful (odds ratio = 14.35) or parasitized birds (odds ratio = 6.38). Male territory fidelity was not related to residency, site quality, or previous breeding performance. Natal philopatry was low (7.8%) and similar for males and females. Site quality appeared to influence philopatry, given that no birds reared at a low-quality study site returned there to breed, and birds reared there dispersed farther than birds reared at two other study sites. My results partially support the hypothesis that site fidelity is an adaptive response: (1) previously successful females that switched territories underperformed those that did not switch (P = 0.01); and (2) previously unsuccessful females that switched territories outperformed those that did not switch, but not significantly (P = 0.22).

Using mixed methods to assess fidelity of delivery and its influencing factors in a complex self-management intervention for people with osteoarthritis and low back pain

PubMed Central

Toomey, Elaine; Matthews, James; Hurley, Deirdre A

2017-01-01

Objectives and design Despite an increasing awareness of the importance of fidelity of delivery within complex behaviour change interventions, it is often poorly assessed. This mixed methods study aimed to establish the fidelity of delivery of a complex self-management intervention and explore the reasons for these findings using a convergent/triangulation design. Setting Feasibility trial of the Self-management of Osteoarthritis and Low back pain through Activity and Skills (SOLAS) intervention (ISRCTN49875385), delivered in primary care physiotherapy. Methods and outcomes 60 SOLAS sessions were delivered across seven sites by nine physiotherapists. Fidelity of delivery of prespecified intervention components was evaluated using (1) audio-recordings (n=60), direct observations (n=24) and self-report checklists (n=60) and (2) individual interviews with physiotherapists (n=9). Quantitatively, fidelity scores were calculated using percentage means and SD of components delivered. Associations between fidelity scores and physiotherapist variables were analysed using Spearman’s correlations. Interviews were analysed using thematic analysis to explore potential reasons for fidelity scores. Integration of quantitative and qualitative data occurred at an interpretation level using triangulation. Results Quantitatively, fidelity scores were high for all assessment methods; with self-report (92.7%) consistently higher than direct observations (82.7%) or audio-recordings (81.7%). There was significant variation between physiotherapists’ individual scores (69.8% - 100%). Both qualitative and quantitative data (from physiotherapist variables) found that physiotherapists’ knowledge (Spearman’s association at p=0.003) and previous experience (p=0.008) were factors that influenced their fidelity. The qualitative data also postulated participant-level (eg, individual needs) and programme-level factors (eg, resources) as additional elements that influenced fidelity. Conclusion The intervention was delivered with high fidelity. This study contributes to the limited evidence regarding fidelity assessment methods within complex behaviour change interventions. The findings suggest a combination of quantitative methods is suitable for the assessment of fidelity of delivery. A mixed methods approach provided a more insightful understanding of fidelity and its influencing factors. Trial registration number ISRCTN49875385; Pre-results. PMID:28780544

A unified, multifidelity quasi-newton optimization method with application to aero-structural designa

NASA Astrophysics Data System (ADS)

Bryson, Dean Edward

A model's level of fidelity may be defined as its accuracy in faithfully reproducing a quantity or behavior of interest of a real system. Increasing the fidelity of a model often goes hand in hand with increasing its cost in terms of time, money, or computing resources. The traditional aircraft design process relies upon low-fidelity models for expedience and resource savings. However, the reduced accuracy and reliability of low-fidelity tools often lead to the discovery of design defects or inadequacies late in the design process. These deficiencies result either in costly changes or the acceptance of a configuration that does not meet expectations. The unknown opportunity cost is the discovery of superior vehicles that leverage phenomena unknown to the designer and not illuminated by low-fidelity tools. Multifidelity methods attempt to blend the increased accuracy and reliability of high-fidelity models with the reduced cost of low-fidelity models. In building surrogate models, where mathematical expressions are used to cheaply approximate the behavior of costly data, low-fidelity models may be sampled extensively to resolve the underlying trend, while high-fidelity data are reserved to correct inaccuracies at key locations. Similarly, in design optimization a low-fidelity model may be queried many times in the search for new, better designs, with a high-fidelity model being exercised only once per iteration to evaluate the candidate design. In this dissertation, a new multifidelity, gradient-based optimization algorithm is proposed. It differs from the standard trust region approach in several ways, stemming from the new method maintaining an approximation of the inverse Hessian, that is the underlying curvature of the design problem. Whereas the typical trust region approach performs a full sub-optimization using the low-fidelity model at every iteration, the new technique finds a suitable descent direction and focuses the search along it, reducing the number of low-fidelity evaluations required. This narrowing of the search domain also alleviates the burden on the surrogate model corrections between the low- and high-fidelity data. Rather than requiring the surrogate to be accurate in a hyper-volume bounded by the trust region, the model needs only to be accurate along the forward-looking search direction. Maintaining the approximate inverse Hessian also allows the multifidelity algorithm to revert to high-fidelity optimization at any time. In contrast, the standard approach has no memory of the previously-computed high-fidelity data. The primary disadvantage of the proposed algorithm is that it may require modifications to the optimization software, whereas standard optimizers may be used as black-box drivers in the typical trust region method. A multifidelity, multidisciplinary simulation of aeroelastic vehicle performance is developed to demonstrate the optimization method. The numerical physics models include body-fitted Euler computational fluid dynamics; linear, panel aerodynamics; linear, finite-element computational structural mechanics; and reduced, modal structural bases. A central element of the multifidelity, multidisciplinary framework is a shared parametric, attributed geometric representation that ensures the analysis inputs are consistent between disciplines and fidelities. The attributed geometry also enables the transfer of data between disciplines. The new optimization algorithm, a standard trust region approach, and a single-fidelity quasi-Newton method are compared for a series of analytic test functions, using both polynomial chaos expansions and kriging to correct discrepancies between fidelity levels of data. In the aggregate, the new method requires fewer high-fidelity evaluations than the trust region approach in 51% of cases, and the same number of evaluations in 18%. The new approach also requires fewer low-fidelity evaluations, by up to an order of magnitude, in almost all cases. The efficacy of both multifidelity methods compared to single-fidelity optimization depends significantly on the behavior of the high-fidelity model and the quality of the low-fidelity approximation, though savings are realized in a large number of cases. The multifidelity algorithm is also compared to the single-fidelity quasi-Newton method for complex aeroelastic simulations. The vehicle design problem includes variables for planform shape, structural sizing, and cruise condition with constraints on trim and structural stresses. Considering the objective function reduction versus computational expenditure, the multifidelity process performs better in three of four cases in early iterations. However, the enforcement of a contracting trust region slows the multifidelity progress. Even so, leveraging the approximate inverse Hessian, the optimization can be seamlessly continued using high-fidelity data alone. Ultimately, the proposed new algorithm produced better designs in all four cases. Investigating the return on investment in terms of design improvement per computational hour confirms that the multifidelity advantage is greatest in early iterations, and managing the transition to high-fidelity optimization is critical.

78 FR 2456 - Fidelity Commonwealth Trust, et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-11

...] Fidelity Commonwealth Trust, et al.; Notice of Application January 7, 2013. AGENCY: Securities and Exchange... companies and unit investment trusts outside of the same group of investment companies as the series to...-feeder structure. Applicants: Fidelity Commonwealth Trust (the ``Trust''), Fidelity Management & Research...

Population genetic analysis of Mountain Plover using mitochondrial DNA sequence data

USGS Publications Warehouse

Oyler-McCance, S.J.; St. John, J.; Knopf, F.L.; Quinn, T.W.

2005-01-01

Mountain Plover (Charadrius montanus) distribution and abundance have been reduced drastically in the past 30 years and the conversion of shortgrass prairie to agriculture has caused breeding populations to become geographically isolated. This, coupled with the fact that Mountain Plovers are thought to show fidelity to breeding grounds, leads to the prediction that the isolated breeding populations would be genetically distinct. This pattern, if observed, would have important management implications for a species at risk of extinction. Our study examined genetic variation at two mitochondrial regions for 20–30 individuals from each of four breeding sites. We found no evidence of significant population differentiation in the data from the control region or the ATPase 6/8 region. Nested-clade analysis revealed no relationship between haplotype phylogeny, and geography among the 47 control region haplotypes. In the ATPase 6/8 region, however, one of the two clades provided information suggesting that, historically, there has been continuous range expansion. Analysis of mismatch distributions and Tajima's D suggest that the Mountain Plover underwent a population expansion, following the Pleistocene glacial period. To explain the lack of detectable genetic differentiation among populations, despite their geographic isolation and fidelity to breeding locations, we speculate that there is sufficient female-mediated gene flow to homogenize gene pools among populations. Such gene flow might ensue if pair bonds are formed in mixed flocks on wintering grounds rather than on the summer breeding grounds.

Methanol Oxidation on Pt3Sn(111) for Direct Methanol Fuel Cells: Methanol Decomposition.

PubMed

Lu, Xiaoqing; Deng, Zhigang; Guo, Chen; Wang, Weili; Wei, Shuxian; Ng, Siu-Pang; Chen, Xiangfeng; Ding, Ning; Guo, Wenyue; Wu, Chi-Man Lawrence

2016-05-18

PtSn alloy, which is a potential material for use in direct methanol fuel cells, can efficiently promote methanol oxidation and alleviate the CO poisoning problem. Herein, methanol decomposition on Pt3Sn(111) was systematically investigated using periodic density functional theory and microkinetic modeling. The geometries and energies of all of the involved species were analyzed, and the decomposition network was mapped out to elaborate the reaction mechanisms. Our results indicated that methanol and formaldehyde were weakly adsorbed, and the other derivatives (CHxOHy, x = 1-3, y = 0-1) were strongly adsorbed and preferred decomposition rather than desorption on Pt3Sn(111). The competitive methanol decomposition started with the initial O-H bond scission followed by successive C-H bond scissions, (i.e., CH3OH → CH3O → CH2O → CHO → CO). The Brønsted-Evans-Polanyi relations and energy barrier decomposition analyses identified the C-H and O-H bond scissions as being more competitive than the C-O bond scission. Microkinetic modeling confirmed that the vast majority of the intermediates and products from methanol decomposition would escape from the Pt3Sn(111) surface at a relatively low temperature, and the coverage of the CO residue decreased with an increase in the temperature and decrease in partial methanol pressure.

Fidelity and outcomes in six integrated dual disorders treatment programs.

PubMed

Chandler, Daniel W

2011-02-01

Fidelity scores and outcomes were measured in six outpatient programs in California which implemented Integrated Dual Disorders Treatment (IDDT). Outcomes were measured for 1 year in four sites and 2 years in two sites; fidelity was assessed at 6 month intervals. Three of the six sites achieved high fidelity (at least a 4 on a 5 point fidelity scale) and three moderate fidelity (at least a 3). Retention in treatment, mental health functioning, stage of substance abuse treatment, abstinence, and psychiatric hospitalization were measured. Outcomes for individual programs were generally positive but not consistent within programs or across programs. Using pooled data in a longitudinal regression model with random effects at person level and adjustment of standard errors for clustering by site, change over time was not statistically significant for the primary outcomes. Fidelity scores had limited association with positive outcomes.

Sustaining Fidelity Following the Nationwide PMTO™ Implementation in Norway

PubMed Central

Forgatch, Marion S.; DeGarmo, David S.

2011-01-01

This report describes three studies from the nationwide Norwegian implementation of Parent Management Training – Oregon Model (PMTO™), an empirically supported treatment for families of children with behavior problems (Forgatch and Patterson 2010). Separate stages of the implementation were evaluated using a fidelity measure based on direct observation of intervention sessions. Study 1 assessed growth in fidelity observed early, mid, and late in the training of a group of practitioners. We hypothesized increased fidelity and decreased variability in practice. Study 2 evaluated method fidelity over the course of three generations of practitioners trained in PMTO. Generation 1 (G1) was trained by the PMTO developer/purveyors; Generation 2 (G2) was trained by selected G1 Norwegian trainers; and Generation 3 (G3) was trained by G1 and G2 trainers. We hypothesized decrease in fidelity with each generation. Study 3 tested the predictive validity of fidelity in a cross-cultural replication, hypothesizing that higher fidelity scores would correlate with improved parenting practices observed in parent-child interactions before and after treatment. In Study 1, trainees' performance improved and became more homogeneous as predicted. In Study 2, a small decline in fidelity followed the transfer from the purveyor trainers to Norwegian trainers in G2, but G3 scores were equivalent to those attained by G1. Thus, the hypothesis was not fully supported. Finally, the FIMP validity model replicated; PMTO fidelity significantly contributed to improvements in parenting practices from pre- to post-treatment. The data indicate that PMTO was transferred successfully to Norwegian implementation with sustained fidelity and cross-cultural generalization. PMID:21671090

Creation of a Rapid High-Fidelity Aerodynamics Module for a Multidisciplinary Design Environment

NASA Technical Reports Server (NTRS)

Srinivasan, Muktha; Whittecar, William; Edwards, Stephen; Mavris, Dimitri N.

2012-01-01

In the traditional aerospace vehicle design process, each successive design phase is accompanied by an increment in the modeling fidelity of the disciplinary analyses being performed. This trend follows a corresponding shrinking of the design space as more and more design decisions are locked in. The correlated increase in knowledge about the design and decrease in design freedom occurs partly because increases in modeling fidelity are usually accompanied by significant increases in the computational expense of performing the analyses. When running high fidelity analyses, it is not usually feasible to explore a large number of variations, and so design space exploration is reserved for conceptual design, and higher fidelity analyses are run only once a specific point design has been selected to carry forward. The designs produced by this traditional process have been recognized as being limited by the uncertainty that is present early on due to the use of lower fidelity analyses. For example, uncertainty in aerodynamics predictions produces uncertainty in trajectory optimization, which can impact overall vehicle sizing. This effect can become more significant when trajectories are being shaped by active constraints. For example, if an optimal trajectory is running up against a normal load factor constraint, inaccuracies in the aerodynamic coefficient predictions can cause a feasible trajectory to be considered infeasible, or vice versa. For this reason, a trade must always be performed between the desired fidelity and the resources available. Apart from this trade between fidelity and computational expense, it is very desirable to use higher fidelity analyses earlier in the design process. A large body of work has been performed to this end, led by efforts in the area of surrogate modeling. In surrogate modeling, an up-front investment is made by running a high fidelity code over a Design of Experiments (DOE); once completed, the DOE data is used to create a surrogate model, which captures the relationships between input variables and responses into regression equations. Depending on the dimensionality of the problem and the fidelity of the code for which a surrogate model is being created, the initial DOE can itself be computationally prohibitive to run. Cokriging, a modeling approach from the field of geostatistics, provides a desirable compromise between computational expense and fidelity. To do this, cokriging leverages a large body of data generated by a low fidelity analysis, combines it with a smaller set of data from a higher fidelity analysis, and creates a kriging surrogate model with prediction fidelity approaching that of the higher fidelity analysis. When integrated into a multidisciplinary environment, a disciplinary analysis module employing cokriging can raise the analysis fidelity without drastically impacting the expense of design iterations. This is demonstrated through the creation of an aerodynamics analysis module in NASA s OpenMDAO framework. Aerodynamic analyses including Missile DATCOM, APAS, and USM3D are leveraged to create high fidelity aerodynamics decks for parametric vehicle geometries, which are created in NASA s Vehicle Sketch Pad (VSP). Several trade studies are performed to examine the achieved level of model fidelity, and the overall impact to vehicle design is quantified.

Enhancing Fidelity in Adventure Education and Adventure Therapy

ERIC Educational Resources Information Center

Tucker, Anita R.; Rheingold, Alison

2010-01-01

Although the importance of addressing and evaluating treatment and program fidelity is clearly emphasized in the literature on psychology, education, and health, little attention has been given to fidelity in adventure literature or research. Program fidelity refers to whether or not, and how well, a specific intervention or program was…

Examining How Treatment Fidelity Is Supported, Measured, and Reported in K-3 Reading Intervention Research

ERIC Educational Resources Information Center

Capin, Philip; Walker, Melodee A.; Vaughn, Sharon; Wanzek, Jeanne

2017-01-01

Treatment fidelity data (descriptive and statistical) are critical to interpreting and generalizing outcomes of intervention research. Despite recommendations for treatment fidelity reporting from funding agencies and researchers, past syntheses have found treatment fidelity is frequently unreported (e.g., Swanson, "The Journal of Special…

Direct NMR Evidence that Transient Tautomeric and Anionic States in dG·dT Form Watson-Crick-like Base Pairs.

PubMed

Szymanski, Eric S; Kimsey, Isaac J; Al-Hashimi, Hashim M

2017-03-29

The replicative and translational machinery utilizes the unique geometry of canonical G·C and A·T/U Watson-Crick base pairs to discriminate against DNA and RNA mismatches in order to ensure high fidelity replication, transcription, and translation. There is growing evidence that spontaneous errors occur when mismatches adopt a Watson-Crick-like geometry through tautomerization and/or ionization of the bases. Studies employing NMR relaxation dispersion recently showed that wobble dG·dT and rG·rU mismatches in DNA and RNA duplexes transiently form tautomeric and anionic species with probabilities (≈0.01-0.40%) that are in concordance with replicative and translational errors. Although computational studies indicate that these exceptionally short-lived and low-abundance species form Watson-Crick-like base pairs, their conformation could not be directly deduced from the experimental data, and alternative pairing geometries could not be ruled out. Here, we report direct NMR evidence that the transient tautomeric and anionic species form hydrogen-bonded Watson-Crick-like base pairs. A guanine-to-inosine substitution, which selectively knocks out a Watson-Crick-type (G)N2H 2 ···O2(T) hydrogen bond, significantly destabilized the transient tautomeric and anionic species, as assessed by lack of any detectable chemical exchange by imino nitrogen rotating frame spin relaxation (R 1ρ ) experiments. An 15 N R 1ρ NMR experiment targeting the amino nitrogen of guanine (dG-N2) provides direct evidence for Watson-Crick (G)N2H 2 ···O2(T) hydrogen bonding in the transient tautomeric state. The strategy presented in this work can be generally applied to examine hydrogen-bonding patterns in nucleic acid transient states including in other tautomeric and anionic species that are postulated to play roles in replication and translational errors.

Assigning Peptide Disulfide Linkage Pattern Among Regio-Isomers via Methoxy Addition to Disulfide and Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Durand, Kirt L.; Tan, Lei; Stinson, Craig A.; Love-Nkansah, Chasity B.; Ma, Xiaoxiao; Xia, Yu

2017-06-01

Pinpointing disulfide linkage pattern is critical in the characterization of proteins and peptides consisting of multiple disulfide bonds. Herein, we report a method based on coupling online disulfide modification and tandem mass spectrometry (MS/MS) to distinguish peptide disulfide regio-isomers. Such a method relies on a new disulfide bond cleavage reaction in solution, involving methanol as a reactant and 254 nm ultraviolet (UV) irradiation. This reaction leads to selective cleavage of a disulfide bond and formation of sulfenic methyl ester (-SOCH3) at one cysteine residue and a thiol (-SH) at the other. Under low energy collision-induced dissociation (CID), cysteine sulfenic methyl ester motif produces a signature methanol loss (-32 Da), allowing its identification from other possible isomeric structures such as S-hydroxylmethyl (-SCH2OH) and methyl sulfoxide (-S(O)-CH3). Since disulfide bond can be selectively cleaved and modified upon methoxy addition, subsequent MS2 CID of the methoxy addition product provides enhanced sequence coverage as demonstrated by the analysis of bovine insulin. More importantly, this reaction does not induce disulfide scrambling, likely due to the fact that radical intermediates are not involved in the process. An approach based on methoxy addition followed by MS3 CID has been developed for assigning disulfide linkage patterns in peptide disulfide regio-isomers. This methodology was successfully applied to characterizing peptide systems having two disulfide bonds and three disulfide linkage isomers: side-by-side, overlapped, and looped-within-a-loop configurations. [Figure not available: see fulltext.

Adsorbate-induced reconstruction in the phase 1 × 2-3H/Rh(110)

NASA Astrophysics Data System (ADS)

Michl, M.; Nichtl-Pecher, W.; Oed, W.; Landskron, H.; Heinz, K.; Müller, K.

1989-10-01

The 1 × 2-3H superstructure of hydrogen on Rh(110) at coverage θ = {3}/{2} is analysed by low energy electron diffraction at 90 K. The spectra of eight beams are recorded with a computer-controlled TV measurement technique which yields low noise data even for weak superstructure spots by multiple averaging. Comparison to full dynamical calculations shows that a kinematic treatment of the hydrogen layer diffraction coupled to the full dynamical diffraction of the substrate is a very good approximation. Spectra computed in this way are compared with experimental data by R-factor evaluation. The three non-equivalent hydrogen atoms are found to adsorb in quasi-three-fold coordinated adsorption sites with slightly different local configurations and with H-Rh bond lengths between 1.87 and 1.93 Å to the first-layer rhodium atoms. Interaction between the adatoms seems to weaken the bonding to the adjacent atom in the second layer, so that H-Rh bond lengths larger than 2.17 Å result. A slight reconstruction of the substrate is necessary to bring superstructure spot intensities near the experimentally observed level. Rhodium atoms bonded to two hydrogen atoms are moved out of the surface by 0.03 ± 0.02 Å relative to Rh atoms bonded to only a single H atom. The relaxation of the first Rh layer spacing is determined to be {d 12}/{d 0} = -3.8 ± 1% and {d 22}/{d 0} = 0 ± 1% . The best fit Pendry R-factor is 0.33.

Spider: Probing the Early Universe with a Large-Scale CMB Polarization Survey

NASA Astrophysics Data System (ADS)

Jones, William

The standard dark-matter and dark-energy dominated cosmological model (LCDM) has proven to be remarkably successful in describing the current state and past evolution of the Universe. However, there remain significant uncertainties regarding the physical mechanisms that established the initial conditions upon which the LCDM predictions rely. Theories of cosmic genesis - the extremely high energy mechanisms that established these conditions - should be expected to provide a natural description of the nearly flat geometry of the Universe, the existence of super-horizon density correlations, and the adiabatic, Gaussian and nearly scale-invariant nature of the observed primordial density perturbations. The primary objective of Spider is to subject models of the early Universe to observational test, probing fundamental physics at energy scales far beyond the reach of terrestrial particle accelerators. The main scientific result will be to characterize, or place stringent upper limits on the level of the odd-parity polarization of the CMB. In the context of the inflationary paradigm, Spider will confirm or exclude the predictions of the simplest single-field inflationary models near the Lyth bound, characterized by tensor to scalar ratios r 0.03. While viable alternatives to the inflationary paradigm are an active and important area of investigation, including string cosmologies and cyclic models, early Universe models described by inflationary periods are now widely accepted as the underlying cause behind much of what we observe in cosmology today. Nevertheless, we know very little about the mechanism that would drive inflation or the energy scale at which it occurred, and the paradigm faces significant questions about the viability of the framework as a scientific theory. Fortunately, inflationary paradigms and alternative theories offer distinct predictions regarding the statistical properties of the Cosmic Microwave Background radiation. Spider will use measurements of the polarization of the CMB to search for the signature of primordial gravitational waves that are predicted within the currently favored theories of inflation. A definitive detection of this signal would provide the first direct insight into the underlying physics of inflation as well as a measurement of its energy scale. A stringent limit on the amplitude of this signal would exclude the currently favored class of inflationary models, bolstering the case for alternative theories. Spider is a suborbital Long-Duration Balloon payload housing six cryogenic smallaperture (half-degree resolution) millimeter-wave polarimeters. The frequency bands of the individual polarimeters are chosen to optimize overall sensitivity to the inflationary CMB polarization signal in the presence of Galactic foregrounds. By making extremely deep, high fidelity measurements of the entire portion of the southern sky that is relatively free of Galactic emission, the Spider data complement those of Planck (in sensitivity and control of systematics) PIPER (in frequency coverage) and EBEX (in sky coverage and angular scale). The data from Spider's inaugural flight in 2015 has resulted in high signal-to-noise maps of the southern Galactic hemisphere covering 10% of the full sky at each of 94 and 150 GHz. The payload is now being fabricated and fitted with a suite of 285 GHz cameras to extend our frequency coverage, improving our ability to disentangle the Galactic and cosmological signals. If its signature is present in the CMB, Spider's frequency coverage and fidelity to a broad range of angular scales enable the experiment to take a step beyond detection, toward the characterization of the gravitational wave induced signature in the CMB. Additionally Spider serves as a training ground for young scientists, including 16 graduate students (9 female, 7 male).

Influence of different cusp coverage methods for the extension of ceramic inlays on marginal integrity and enamel crack formation in vitro.

PubMed

Krifka, Stephanie; Stangl, Martin; Wiesbauer, Sarah; Hiller, Karl-Anton; Schmalz, Gottfried; Federlin, Marianne

2009-09-01

No information is available to date about cusp design of thin (1.0 mm) non-functional cusps and its influence upon (1) marginal integrity of ceramic inlays (CI) and partial ceramic crowns (PCC) and (2) crack formation of dental tissues. The aim of this in vitro study was to investigate the effect of cusp coverage of thin non-functional cusps on marginal integrity and enamel crack formation. CI and PCC preparations were performed on extracted human molars. Non-functional cusps were adjusted to 1.0-mm wall thickness and 1.0-mm wall thickness with horizontal reduction of about 2.0 mm. Ceramic restorations (Vita Mark II, Cerec3 System) were adhesively luted with Excite/Variolink II. The specimens were exposed to thermocycling and central mechanical loading. Marginal integrity was assessed by evaluating dye penetration after thermal cycling and mechanical loading. Enamel cracks were documented under a reflective-light microscope. The data were statistically analysed with the Mann-Whitney U test, the Fishers exact test (alpha = 0.05) and the error rates method. PCC with horizontal reduction of non-functional cusps showed statistically significant less microleakage than PCC without such a cusp coverage. Preparation designs with horizontal reduction of non-functional cusps showed a tendency to less enamel crack formation than preparation designs without cusp coverage. Thin non-functional cusp walls of adhesively bonded restorations should be completely covered or reduced to avoid enamel cracks and marginal deficiency.

Extending the Conceptualization of Listening Fidelity

ERIC Educational Resources Information Center

Fitch-Hauser, Margaret; Powers, William G.; O'Brien, Kelley; Hanson, Scott

2007-01-01

An exploration of variables potentially related to Listening Fidelity (LF) was conducted through two separate studies. Study 1 indicated that when the potential fidelity of the stimulus message was varied as a function of the number of words and time length, the message with lowest potential fidelity produced significantly lower LF than either the…

Assessing the Implementation Fidelity of Check-In Check-Out Behavioral Interventions in Elementary and Middle Schools

ERIC Educational Resources Information Center

Ruiz, María Isolina; Smith, Traci N.; Naquin, Gale M.; Morgan-D'Atrio, Cynthia; Dellinger, Amy B.

2014-01-01

Implementation fidelity is crucial to the success of behavioral interventions. However, measuring and maintaining intervention implementation fidelity in schools' natural settings can be challenging. This article reports findings from a study examining the implementation fidelity of check-in check-out interventions at an urban school district…

Procedural Fidelity: An Analysis of Measurement and Reporting Practices

ERIC Educational Resources Information Center

Ledford, Jennifer R.; Wolery, Mark

2013-01-01

A systematic analysis was conducted of measurement and reporting practices related to procedural fidelity in single-case research for the past 30 years. Previous reviews of fidelity primarily reported whether fidelity data were collected by authors; these reviews reported that collection was variable, but low across journals and over time. Results…

Beyond teacher training: the critical role of professional development in maintaining curriculum fidelity.

PubMed

LaChausse, Robert G; Clark, Kim R; Chapple, Sabrina

2014-03-01

To examine how teacher characteristics affected program fidelity in an impact evaluation study of the Positive Prevention PLUS program, and to propose a comprehensive teacher training and professional development structure to increase program fidelity. Curriculum fidelity logs, lesson observations, and teacher surveys were used to measure teacher characteristics and implementation fidelity including adherence, adaptation, and lesson quality. Compared with non-health credentialed teachers, credential health education teachers had greater comfort and self-efficacy regarding sex-related instruction. Teacher self-efficacy and comfort were significant predictors of adherence. Implementation fidelity may be linked to teacher characteristics that can be enhanced during curriculum training. A 2-day teacher training may not adequately address teacher facilitation skills or the maintenance of institutional supports for implementing a program with fidelity and quality. A new model of comprehensive teacher training and support is offered. This new training infrastructure is intended to contribute to the school district's institutionalization of higher-quality comprehensive sexual health education and increase program fidelity. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.

Sources of variation in breeding-ground fidelity of mallards (Anas platyrhynchos)

USGS Publications Warehouse

Doherty, P.F.; Nichols, J.D.; Tautin, J.; Voelzer, J.E.; Smith, G.W.; Benning, D.S.; Bentley, V.R.; Bidwell, J.K.; Bollinger, K.S.; Brazda, A.R.; Buelna, E.K.; Goldsberry, J.R.; King, R.J.; Roetker, F.H.; Solberg, J.W.; Thorpe, P.P.; Wortham, J.S.

2002-01-01

Generalizations used to support hypotheses about the evolution of fidelity to breeding areas in birds include the tendency for fidelity to be greater in adult birds than in yearlings. In ducks, in contrast to most bird species, fidelity is thought to be greater among females than males. Researchers have suggested that fidelity in ducks is positively correlated with pond availability. However, most estimates of fidelity on which these inferences have been based represent functions of survival and recapture-resighting probabilities in addition to fidelity. We applied the modeling approach developed by Burnham to recapture and band recovery data of mallard ducks to test the above hypotheses about fidelity. We found little evidence of sex differences in adult philopatry, with females being slightly more philopatric than males in one study area, but not in a second study area. However, yearling females were more philopatric than yearling males in both study areas. We found that adults were generally more philopatric than yearlings. We could find no relationship between fidelity and pond availability. Our results, while partially supporting current theory concerning sex and age differences in philopatry, suggest that adult male mallards are more philopatric than once thought, and we recommend that other generalizations about philopatry be revisited with proper estimation techniques.

High fidelity quantum gates with vibrational qubits.

PubMed

Berrios, Eduardo; Gruebele, Martin; Shyshlov, Dmytro; Wang, Lei; Babikov, Dmitri

2012-11-26

Physical implementation of quantum gates acting on qubits does not achieve a perfect fidelity of 1. The actual output qubit may not match the targeted output of the desired gate. According to theoretical estimates, intrinsic gate fidelities >99.99% are necessary so that error correction codes can be used to achieve perfect fidelity. Here we test what fidelity can be accomplished for a CNOT gate executed by a shaped ultrafast laser pulse interacting with vibrational states of the molecule SCCl(2). This molecule has been used as a test system for low-fidelity calculations before. To make our test more stringent, we include vibrational levels that do not encode the desired qubits but are close enough in energy to interfere with population transfer by the laser pulse. We use two complementary approaches: optimal control theory determines what the best possible pulse can do; a more constrained physical model calculates what an experiment likely can do. Optimal control theory finds pulses with fidelity >0.9999, in excess of the quantum error correction threshold with 8 × 10(4) iterations. On the other hand, the physical model achieves only 0.9992 after 8 × 10(4) iterations. Both calculations converge as an inverse power law toward unit fidelity after >10(2) iterations/generations. In principle, the fidelities necessary for quantum error correction are reachable with qubits encoded by molecular vibrations. In practice, it will be challenging with current laboratory instrumentation because of slow convergence past fidelities of 0.99.

A method for assessing fidelity of delivery of telephone behavioral support for smoking cessation.

PubMed

Lorencatto, Fabiana; West, Robert; Bruguera, Carla; Michie, Susan

2014-06-01

Behavioral support for smoking cessation is delivered through different modalities, often guided by treatment manuals. Recently developed methods for assessing fidelity of delivery have shown that face-to-face behavioral support is often not delivered as specified in the service treatment manual. This study aimed to extend this method to evaluate fidelity of telephone-delivered behavioral support. A treatment manual and transcripts of 75 audio-recorded behavioral support sessions were obtained from the United Kingdom's national Quitline service and coded into component behavior change techniques (BCTs) using a taxonomy of 45 smoking cessation BCTs. Interrater reliability was assessed using percentage agreement. Fidelity was assessed by comparing the number of BCTs identified in the manual with those delivered in telephone sessions by 4 counselors. Fidelity was assessed according to session type, duration, counselor, and BCT. Differences between self-reported and actual BCT use were examined. Average coding reliability was high (81%). On average, 41.8% of manual-specified BCTs were delivered per session (SD = 16.2), with fidelity varying by counselor from 32% to 49%. Fidelity was highest in pre-quit sessions (46%) and for BCT "give options for additional support" (95%). Fidelity was lowest for quit-day sessions (35%) and BCT "set graded tasks" (0%). Session duration was positively correlated with fidelity (r = .585; p < .01). Significantly fewer BCTs were used than were reported as being used, t(15) = -5.52, p < .001. The content of telephone-delivered behavioral support can be reliably coded in terms of BCTs. This can be used to assess fidelity to treatment manuals and to in turn identify training needs. The observed low fidelity underlines the need to establish routine procedures for monitoring delivery of behavioral support. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Fidelity and moderating factors in complex interventions: a case study of a continuum of care program for frail elderly people in health and social care

PubMed Central

2012-01-01

Background Prior studies measuring fidelity of complex interventions have mainly evaluated adherence, and not taken factors affecting adherence into consideration. A need for studies that clarify the concept of fidelity and the function of factors moderating fidelity has been emphasized. The aim of the study was to systematically evaluate implementation fidelity and possible factors influencing fidelity of a complex care continuum intervention for frail elderly people. Methods The intervention was a systematization of the collaboration between a nurse with geriatric expertise situated at the emergency department, the hospital ward staff, and a multi-professional team with a case manager in the municipal care services for older people. Implementation was evaluated between September 2008 and May 2010 with observations of work practices, stakeholder interviews, and document analysis according to a modified version of The Conceptual Framework for Implementation Fidelity. Results A total of 16 of the 18 intervention components were to a great extent delivered as planned, while some new components were added to the model. No changes in the frequency or duration of the 18 components were observed, but the dose of the added components varied over time. Changes in fidelity were caused in a complex, interrelated fashion by all the moderating factors in the framework, i.e., context, staff and participant responsiveness, facilitation, recruitment, and complexity. Discussion The Conceptual Framework for Implementation Fidelity was empirically useful and included comprehensive measures of factors affecting fidelity. Future studies should focus on developing the framework with regard to how to investigate relationships between the moderating factors and fidelity over time. Trial registration ClinicalTrials.gov, NCT01260493. PMID:22436121

Enhanced fidelity of an educational intervention on skin self-examination through surveillance and standardization

PubMed Central

Gaber, Rikki; Mallett, Kimberly A.; Hultgren, Brittney; Turrisi, Rob; Gilbertsen, Margaret L.; Martini, Mary C.; Robinson, June K.

2014-01-01

Background Melanoma can metastasize but is often successfully treated when discovered in an early stage. Melanoma patients and their skin check partners can learn skin self-examination (SSE) skills and these skills can be improved by practice. The purpose of this study is to determine the degree of fidelity with which educational in-person SSE intervention can be delivered by trained research coordinators to patients at risk of developing another melanoma and their skin check partners. Methods The in-person intervention was performed in two iterations. In phase 1 (2006-2008), the research coordinators were trained to perform the intervention using a written script. In phase 2 (2011-2013), the research coordinators were trained to perform the intervention with a PowerPoint aid. Each research coordinator was individually counseled by one of the authors (KM) to insure standardization and enhance fidelity of intervention delivery. Phase 1 and Phase 2 were compared on 16 fidelity components. Further, Phase 2 fidelity was assessed by comparing mean scores of fidelity across the five research coordinators who delivered the intervention. Results Phase 2, which utilized a PowerPoint aid, was delivered with a higher degree of fidelity compared to phase 1with four fidelity components with significantly higher fidelity than Phase 1: 1) Explained details of melanoma, χ2 (1, n = 199)= 96.31, p < .001, 2) Discussed when to call doctor, χ2 (1, n = 199) = 53.68, p < .001 3) Explained assessment at month 1, χ2 (1, n = 199)= 12.39, p < .01, and 4) Explained assessment at month 2, χ2 (1, n = 199) = 117.75, p < .001. Further, no significant differences on mean fidelity were found across research coordinators in Phase 2. Discussion When using the PowerPoint aide, the research coordinators delivered the intervention with high fidelity (all scores >14) and there were no mean differences in fidelity across research coordinators, indicating consistency in fidelity. This can be attributed to the standardization and cueing that the PowerPoint program offered. Supervision was also a key component in establishing and maintaining fidelity of the patient educational process. This method of intervention delivery enables trained healthcare professionals to deliver an educational intervention in an effective, consistent manner. PMID:25414761

Enhanced fidelity of an educational intervention on skin self-examination through surveillance and standardization.

PubMed

Gaber, Rikki; Mallett, Kimberly A; Hultgren, Brittney; Turrisi, Rob; Gilbertsen, Margaret L; Martini, Mary C; Robinson, June K

2014-01-01

Melanoma can metastasize but is often successfully treated when discovered in an early stage. Melanoma patients and their skin check partners can learn skin self-examination (SSE) skills and these skills can be improved by practice. The purpose of this study is to determine the degree of fidelity with which educational in-person SSE intervention can be delivered by trained research coordinators to patients at risk of developing another melanoma and their skin check partners. The in-person intervention was performed in two iterations. In phase 1 (2006-2008), the research coordinators were trained to perform the intervention using a written script. In phase 2 (2011-2013), the research coordinators were trained to perform the intervention with a PowerPoint aid. Each research coordinator was individually counseled by one of the authors (KM) to insure standardization and enhance fidelity of intervention delivery. Phase 1 and Phase 2 were compared on 16 fidelity components. Further, Phase 2 fidelity was assessed by comparing mean scores of fidelity across the five research coordinators who delivered the intervention. Phase 2, which utilized a PowerPoint aid, was delivered with a higher degree of fidelity compared to phase 1with four fidelity components with significantly higher fidelity than Phase 1: 1) Explained details of melanoma, χ 2 (1, n = 199)= 96.31, p < .001, 2) Discussed when to call doctor, χ 2 (1, n = 199) = 53.68, p < .001 3) Explained assessment at month 1, χ 2 (1, n = 199)= 12.39, p < .01, and 4) Explained assessment at month 2, χ 2 (1, n = 199) = 117.75, p < .001. Further, no significant differences on mean fidelity were found across research coordinators in Phase 2. When using the PowerPoint aide, the research coordinators delivered the intervention with high fidelity (all scores >14) and there were no mean differences in fidelity across research coordinators, indicating consistency in fidelity. This can be attributed to the standardization and cueing that the PowerPoint program offered. Supervision was also a key component in establishing and maintaining fidelity of the patient educational process. This method of intervention delivery enables trained healthcare professionals to deliver an educational intervention in an effective, consistent manner.

A multi-fidelity framework for physics based rotor blade simulation and optimization

NASA Astrophysics Data System (ADS)

Collins, Kyle Brian

New helicopter rotor designs are desired that offer increased efficiency, reduced vibration, and reduced noise. Rotor Designers in industry need methods that allow them to use the most accurate simulation tools available to search for these optimal designs. Computer based rotor analysis and optimization have been advanced by the development of industry standard codes known as "comprehensive" rotorcraft analysis tools. These tools typically use table look-up aerodynamics, simplified inflow models and perform aeroelastic analysis using Computational Structural Dynamics (CSD). Due to the simplified aerodynamics, most design studies are performed varying structural related design variables like sectional mass and stiffness. The optimization of shape related variables in forward flight using these tools is complicated and results are viewed with skepticism because rotor blade loads are not accurately predicted. The most accurate methods of rotor simulation utilize Computational Fluid Dynamics (CFD) but have historically been considered too computationally intensive to be used in computer based optimization, where numerous simulations are required. An approach is needed where high fidelity CFD rotor analysis can be utilized in a shape variable optimization problem with multiple objectives. Any approach should be capable of working in forward flight in addition to hover. An alternative is proposed and founded on the idea that efficient hybrid CFD methods of rotor analysis are ready to be used in preliminary design. In addition, the proposed approach recognizes the usefulness of lower fidelity physics based analysis and surrogate modeling. Together, they are used with high fidelity analysis in an intelligent process of surrogate model building of parameters in the high fidelity domain. Closing the loop between high and low fidelity analysis is a key aspect of the proposed approach. This is done by using information from higher fidelity analysis to improve predictions made with lower fidelity models. This thesis documents the development of automated low and high fidelity physics based rotor simulation frameworks. The low fidelity framework uses a comprehensive code with simplified aerodynamics. The high fidelity model uses a parallel processor capable CFD/CSD methodology. Both low and high fidelity frameworks include an aeroacoustic simulation for prediction of noise. A synergistic process is developed that uses both the low and high fidelity frameworks together to build approximate models of important high fidelity metrics as functions of certain design variables. To test the process, a 4-bladed hingeless rotor model is used as a baseline. The design variables investigated include tip geometry and spanwise twist distribution. Approximation models are built for metrics related to rotor efficiency and vibration using the results from 60+ high fidelity (CFD/CSD) experiments and 400+ low fidelity experiments. Optimization using the approximation models found the Pareto Frontier anchor points, or the design having maximum rotor efficiency and the design having minimum vibration. Various Pareto generation methods are used to find designs on the frontier between these two anchor designs. When tested in the high fidelity framework, the Pareto anchor designs are shown to be very good designs when compared with other designs from the high fidelity database. This provides evidence that the process proposed has merit. Ultimately, this process can be utilized by industry rotor designers with their existing tools to bring high fidelity analysis into the preliminary design stage of rotors. In conclusion, the methods developed and documented in this thesis have made several novel contributions. First, an automated high fidelity CFD based forward flight simulation framework has been built for use in preliminary design optimization. The framework was built around an integrated, parallel processor capable CFD/CSD/AA process. Second, a novel method of building approximate models of high fidelity parameters has been developed. The method uses a combination of low and high fidelity results and combines Design of Experiments, statistical effects analysis, and aspects of approximation model management. And third, the determination of rotor blade shape variables through optimization using CFD based analysis in forward flight has been performed. This was done using the high fidelity CFD/CSD/AA framework and method mentioned above. While the low and high fidelity predictions methods used in the work still have inaccuracies that can affect the absolute levels of the results, a framework has been successfully developed and demonstrated that allows for an efficient process to improve rotor blade designs in terms of a selected choice of objective function(s). Using engineering judgment, this methodology could be applied today to investigate opportunities to improve existing designs. With improvements in the low and high fidelity prediction components that will certainly occur, this framework could become a powerful tool for future rotorcraft design work. (Abstract shortened by UMI.)

Increasing the Rigor of Procedural Fidelity Assessment: An Empirical Comparison of Direct Observation and Permanent Product Review Methods

ERIC Educational Resources Information Center

Sanetti, Lisa M. Hagermoser; Collier-Meek, Melissa A.

2014-01-01

Although it is widely accepted that procedural fidelity data are important for making valid decisions about intervention effectiveness, there is little empirical guidance for researchers and practitioners regarding how to assess procedural fidelity. A first step in moving procedural fidelity assessment research forward is to develop a…

A Method of Surrogate Model Construction which Leverages Lower-Fidelity Information using Space Mapping Techniques

DTIC Science & Technology

2014-03-27

fidelity. This pairing is accomplished through the use of a space mapping technique, which is a process where the design space of a lower fidelity model...is aligned a higher fidelity model. The intent of applying space mapping techniques to the field of surrogate construction is to leverage the

A Comprehensive Examination of Preschool Teachers' Implementation Fidelity When Using a Supplemental Language and Literacy Curriculum

ERIC Educational Resources Information Center

Piasta, Shayne B.; Justice, Laura M.; McGinty, Anita; Mashburn, Andrew; Slocum, Laura

2015-01-01

Background: Recent curriculum studies raise a number of questions concerning teachers' implementation fidelity, including the extent to which fidelity to multiple curriculum components is achieved and measured and the extent to which fidelity serves as a mechanism for impacting children's learning. Objective: Within the context of a language and…

Physiological Based Simulator Fidelity Design Guidance

NASA Technical Reports Server (NTRS)

Schnell, Thomas; Hamel, Nancy; Postnikov, Alex; Hoke, Jaclyn; McLean, Angus L. M. Thom, III

2012-01-01

The evolution of the role of flight simulation has reinforced assumptions in aviation that the degree of realism in a simulation system directly correlates to the training benefit, i.e., more fidelity is always better. The construct of fidelity has several dimensions, including physical fidelity, functional fidelity, and cognitive fidelity. Interaction of different fidelity dimensions has an impact on trainee immersion, presence, and transfer of training. This paper discusses research results of a recent study that investigated if physiological-based methods could be used to determine the required level of simulator fidelity. Pilots performed a relatively complex flight task consisting of mission task elements of various levels of difficulty in a fixed base flight simulator and a real fighter jet trainer aircraft. Flight runs were performed using one forward visual channel of 40 deg. field of view for the lowest level of fidelity, 120 deg. field of view for the middle level of fidelity, and unrestricted field of view and full dynamic acceleration in the real airplane. Neuro-cognitive and physiological measures were collected under these conditions using the Cognitive Avionics Tool Set (CATS) and nonlinear closed form models for workload prediction were generated based on these data for the various mission task elements. One finding of the work described herein is that simple heart rate is a relatively good predictor of cognitive workload, even for short tasks with dynamic changes in cognitive loading. Additionally, we found that models that used a wide range of physiological and neuro-cognitive measures can further boost the accuracy of the workload prediction.

Investigating variations in implementation fidelity of an organizational-level occupational health intervention.

PubMed

Augustsson, Hanna; von Thiele Schwarz, Ulrica; Stenfors-Hayes, Terese; Hasson, Henna

2015-06-01

The workplace has been suggested as an important arena for health promotion, but little is known about how the organizational setting influences the implementation of interventions. The aims of this study are to evaluate implementation fidelity in an organizational-level occupational health intervention and to investigate possible explanations for variations in fidelity between intervention units. The intervention consisted of an integration of health promotion, occupational health and safety, and a system for continuous improvements (Kaizen) and was conducted in a quasi-experimental design at a Swedish hospital. Implementation fidelity was evaluated with the Conceptual Framework for Implementation Fidelity and implementation factors used to investigate variations in fidelity with the Framework for Evaluating Organizational-level Interventions. A multi-method approach including interviews, Kaizen notes, and questionnaires was applied. Implementation fidelity differed between units even though the intervention was introduced and supported in the same way. Important differences in all elements proposed in the model for evaluating organizational-level interventions, i.e., context, intervention, and mental models, were found to explain the differences in fidelity. Implementation strategies may need to be adapted depending on the local context. Implementation fidelity, as well as pre-intervention implementation elements, is likely to affect the implementation success and needs to be assessed in intervention research. The high variation in fidelity across the units indicates the need for adjustments to the type of designs used to assess the effects of interventions. Thus, rather than using designs that aim to control variation, it may be necessary to use those that aim at exploring and explaining variation, such as adapted study designs.

Methods for Streamlining Intervention Fidelity Checklists: An Example from the Chronic Disease Self-Management Program

PubMed Central

Ahn, SangNam; Smith, Matthew Lee; Altpeter, Mary; Belza, Basia; Post, Lindsey; Ory, Marcia G.

2015-01-01

Maintaining intervention fidelity should be part of any programmatic quality assurance (QA) plan and is often a licensure requirement. However, fidelity checklists designed by original program developers are often lengthy, which makes compliance difficult once programs become widely disseminated in the field. As a case example, we used Stanford’s original Chronic Disease Self-Management Program (CDSMP) fidelity checklist of 157 items to demonstrate heuristic procedures for generating shorter fidelity checklists. Using an expert consensus approach, we sought feedback from active master trainers registered with the Stanford University Patient Education Research Center about which items were most essential to, and also feasible for, assessing fidelity. We conducted three sequential surveys and one expert group-teleconference call. Three versions of the fidelity checklist were created using different statistical and methodological criteria. In a final group-teleconference call with seven national experts, there was unanimous agreement that all three final versions (e.g., a 34-item version, a 20-item version, and a 12-item version) should be made available because the purpose and resources for administering a checklist might vary from one setting to another. This study highlights the methodology used to generate shorter versions of a fidelity checklist, which has potential to inform future QA efforts for this and other evidence-based programs (EBP) for older adults delivered in community settings. With CDSMP and other EBP, it is important to differentiate between program fidelity as mandated by program developers for licensure, and intervention fidelity tools for providing an “at-a-glance” snapshot of the level of compliance to selected program indicators. PMID:25964941

Blending Qualitative and Computational Linguistics Methods for Fidelity Assessment: Experience with the Familias Unidas Preventive Intervention.

PubMed

Gallo, Carlos; Pantin, Hilda; Villamar, Juan; Prado, Guillermo; Tapia, Maria; Ogihara, Mitsunori; Cruden, Gracelyn; Brown, C Hendricks

2015-09-01

Careful fidelity monitoring and feedback are critical to implementing effective interventions. A wide range of procedures exist to assess fidelity; most are derived from observational assessments (Schoenwald and Garland, Psycholog Assess 25:146-156, 2013). However, these fidelity measures are resource intensive for research teams in efficacy/effectiveness trials, and are often unattainable or unmanageable for the host organization to rate when the program is implemented on a large scale. We present a first step towards automated processing of linguistic patterns in fidelity monitoring of a behavioral intervention using an innovative mixed methods approach to fidelity assessment that uses rule-based, computational linguistics to overcome major resource burdens. Data come from an effectiveness trial of the Familias Unidas intervention, an evidence-based, family-centered preventive intervention found to be efficacious in reducing conduct problems, substance use and HIV sexual risk behaviors among Hispanic youth. This computational approach focuses on "joining," which measures the quality of the working alliance of the facilitator with the family. Quantitative assessments of reliability are provided. Kappa scores between a human rater and a machine rater for the new method for measuring joining reached 0.83. Early findings suggest that this approach can reduce the high cost of fidelity measurement and the time delay between fidelity assessment and feedback to facilitators; it also has the potential for improving the quality of intervention fidelity ratings.

Blending Qualitative and Computational Linguistics Methods for Fidelity Assessment: Experience with the Familias Unidas Preventive Intervention

PubMed Central

Gallo, Carlos; Pantin, Hilda; Villamar, Juan; Prado, Guillermo; Tapia, Maria; Ogihara, Mitsunori; Cruden, Gracelyn; Brown, C Hendricks

2014-01-01

Careful fidelity monitoring and feedback are critical to implementing effective interventions. A wide range of procedures exist to assess fidelity; most are derived from observational assessments (Schoenwald et al, 2013). However, these fidelity measures are resource intensive for research teams in efficacy/effectiveness trials, and are often unattainable or unmanageable for the host organization to rate when the program is implemented on a large scale. We present a first step towards automated processing of linguistic patterns in fidelity monitoring of a behavioral intervention using an innovative mixed methods approach to fidelity assessment that uses rule-based, computational linguistics to overcome major resource burdens. Data come from an effectiveness trial of the Familias Unidas intervention, an evidence-based, family-centered preventive intervention found to be efficacious in reducing conduct problems, substance use and HIV sexual risk behaviors among Hispanic youth. This computational approach focuses on “joining,” which measures the quality of the working alliance of the facilitator with the family. Quantitative assessments of reliability are provided. Kappa scores between a human rater and a machine rater for the new method for measuring joining reached .83. Early findings suggest that this approach can reduce the high cost of fidelity measurement and the time delay between fidelity assessment and feedback to facilitators; it also has the potential for improving the quality of intervention fidelity ratings. PMID:24500022

The Validity and Incremental Validity of Knowledge Tests, Low-Fidelity Simulations, and High-Fidelity Simulations for Predicting Job Performance in Advanced-Level High-Stakes Selection

ERIC Educational Resources Information Center

Lievens, Filip; Patterson, Fiona

2011-01-01

In high-stakes selection among candidates with considerable domain-specific knowledge and experience, investigations of whether high-fidelity simulations (assessment centers; ACs) have incremental validity over low-fidelity simulations (situational judgment tests; SJTs) are lacking. Therefore, this article integrates research on the validity of…

Evaluation of Intervention Fidelity in a Multisite Clinical Trial in Persons With Multiple Sclerosis.

PubMed

Morrison, Janet D; Becker, Heather; Stuifbergen, Alexa K

2017-12-01

Careful consideration of intervention fidelity is critical to establishing the validity and reliability of research findings, yet such reports are often lacking in the research literature. It is imperative that intervention fidelity be methodically evaluated and reported to promote the translation of effective interventions into sound evidence-based practice. The purpose of this article is to explore strategies used to promote intervention fidelity, incorporating examples from a multisite clinical trial, that illustrate the National Institutes of Health Behavior Change Consortium's 5 domains for recommended treatment practices: (1) study design, (2) facilitator training, (3) intervention delivery, (4) intervention receipt, and (5) intervention enactment. A multisite randomized clinical trial testing the efficacy of a computer-assisted cognitive rehabilitation intervention for adults with multiple sclerosis is used to illustrate strategies promoting intervention fidelity. Data derived from audiotapes of intervention classes, audits of computer exercises completed by participants, participant class attendance, and goal attainment scaling suggested relatively high fidelity to the intervention protocol. This study illustrates how to report intervention fidelity in the literature guided by best practice strategies, which may serve to promote fidelity monitoring and reporting in future studies.

Fiscal loss and program fidelity: impact of the economic downturn on HIV/STI prevention program fidelity.

PubMed

Catania, Joseph A; Dolcini, M Margaret; Gandelman, Alice A; Narayanan, Vasudha; McKay, Virginia R

2014-03-01

The economic downturn of 2007 created significant fiscal losses for public and private agencies conducting behavioral prevention. Such macro-economic changes may influence program implementation and sustainability. We examined how public and private agencies conducting RESPECT, a brief HIV/STI (sexually transmitted infection) counseling and testing intervention, adapted to fiscal loss and how these adaptations impacted program fidelity. We collected qualitative and quantitative data in a national sample of 15 agencies experiencing fiscal loss. Using qualitative analyses, we examined how program fidelity varied with different types of adaptations. Agencies reported three levels of adaptation: agency-level, program-level, and direct fiscal remedies. Private agencies tended to use direct fiscal remedies, which were associated with higher fidelity. Some agency-level adaptations contributed to reductions in procedural fit, leading to negative staff morale and decreased confidence in program effectiveness, which in turn, contributed to poor fidelity. Findings describe a "work stress pathway" that links program fiscal losses to poor staff morale and low program fidelity.

Engagement in Training as a Mechanism to Understanding Fidelity of Implementation of the Responsive Classroom Approach.

PubMed

Wanless, Shannon B; Rimm-Kaufman, Sara E; Abry, Tashia; Larsen, Ross A; Patton, Christine L

2015-11-01

Fidelity of implementation of classroom interventions varies greatly, a reality that is concerning because higher fidelity of implementation relates to greater effectiveness of the intervention. We analyzed 126 fourth and fifth grade teachers from the treatment group of a randomized controlled trial of the Responsive Classroom® (RC) approach. Prior to training in the intervention, we assessed factors that had the potential to represent a teacher's readiness to implement with fidelity. These included teachers' observed emotional support, teacher-rated use of intervention practices, teacher-rated self-efficacy, teacher-rated collective responsibility, education level, and years of experience, and they were not directly related to observed fidelity of implementation 2 years later. Further analyses indicated, however, that RC trainers' ratings of teachers' engagement in the initial weeklong RC training mediated the relation between initial observed emotional support and later observed fidelity of implementation. We discuss these findings as a way to advance understanding of teachers' readiness to implement new interventions with fidelity.

Fidelity deviation in quantum teleportation

NASA Astrophysics Data System (ADS)

Bang, Jeongho; Ryu, Junghee; Kaszlikowski, Dagomir

2018-04-01

We analyze the performance of quantum teleportation in terms of average fidelity and fidelity deviation. The average fidelity is defined as the average value of the fidelities over all possible input states and the fidelity deviation is their standard deviation, which is referred to as a concept of fluctuation or universality. In the analysis, we find the condition to optimize both measures under a noisy quantum channel—we here consider the so-called Werner channel. To characterize our results, we introduce a 2D space defined by the aforementioned measures, in which the performance of the teleportation is represented as a point with the channel noise parameter. Through further analysis, we specify some regions drawn for different channel conditions, establishing the connection to the dissimilar contributions of the entanglement to the teleportation and the Bell inequality violation.

The Effect of Tow Shearing on Reinforcement Positional Fidelity in the Manufacture of a Continuous Fiber Reinforced Thermoplastic Matrix Composite via Pultrusion-Like Processing of Commingled Feedstock

NASA Astrophysics Data System (ADS)

Warlick, Kent M.

While the addition of short fiber to 3D printed articles has increased structural performance, ultimate gains will only be realized through the introduction of continuous reinforcement placed along pre-planned load paths. Most additive manufacturing research focusing on the addition of continuous reinforcement has revolved around utilization of a prefrabricated composite filament or a fiber and matrix mixed within a hot end prior to deposition on a printing surface such that conventional extrusion based FDM can be applied. Although stronger 3D printed parts can be made in this manner, high quality homogenous composites are not possible due to fiber dominated regions, matrix dominated regions, and voids present between adjacent filaments. Conventional composite manufacturing processes are much better at creating homogeneous composites; however, the layer by layer approach in which they are made is inhibiting the alignment of reinforcement with loads. Automated Fiber Placement techniques utilize in plane bending deformation of the tow to facilitate tow steering. Due to buckling fibers on the inner radius of curves, manufacturers recommend a minimum curvature for path placement with this technique. A method called continuous tow shearing has shown promise to enable the placement of tows in complex patterns without tow buckling, spreading, and separation inherent in conventional forms of automated reinforcement positioning. The current work employs fused deposition modeling hardware and the continuous tow shearing technique to manufacture high quality fiber reinforced composites with high positional fidelity, varying continuous reinforcement orientations within a layer, and plastic elements incorporated enabling the ultimate gains in structural performance possible. A mechanical system combining concepts of additive manufacturing with fiber placement via filament winding was developed. Paths with and without tension inherent in filament winding were analyzed through microscopy in order to examine best and worst case scenarios. High quality fiber reinforced composite materials, in terms of low void content, high fiber volume fractions and homogeneity in microstructure, were manufactured in both of these scenarios. In order to improve fidelity and quality in fiber path transition regions, a forced air cooling manifold was designed, printed, and implemented into the current system. To better understand the composite performance that results from varying pertinent manufacturing parameters, the effect of feed rate, hot end temperature, forced air cooling, and deposition surface (polypropylene and previously deposited glass polypropylene commingled tow) on interply performance, microstructure, and positional fidelity were analyzed. Interply performance, in terms of average maximum load and average peel strength, was quantified through a t-peel test of the bonding quality between two surfaces. With use of forced air cooling, minor decreases in average peel strength were present due to a reduction in tow deposition temperature which was found to be the variable most indicative of performance. Average maximum load was comparable between the forced air cooled and non-air cooled samples. Microstructure was evaluated through characterization of composite area, void content, and flash percentage. Low void contents mostly between five to seven percent were attained. Further reduction of this void content to two percent is possible through higher processing temperatures; however, reduced composite area, low average peel strength performance, and the presence of smoke during manufacturing implied thermal degradation of the polypropylene matrix occurred in these samples with higher processing temperatures. Positional fidelity was measured through calculations of shear angle, shift width, and error of a predefined path. While positional fidelity variation was low with a polypropylene deposition surface, forced air cooling is necessary to achieve fidelity on top of an already deposited tow surface as evident by the fifty-six percent reduction in error tolerance profile achieved. Lastly, proof of concept articles with unique fiber paths and neat plastic elements incorporated were produced to demonstrate fiber placement along pre-planned load paths and the ability to achieve greater structural efficiency through the use of less material. The results show that high positional fidelity and high quality composites can be produced through the use of the tow shearing technique implemented in the developed mechanical system. The implementation of forced air cooling was critical in achieving fidelity and quality in transition regions. Alignment of continuous reinforcement with pre-planned load paths was demonstrated in the proof of concept article with varying fiber orientations within a layer. Combining fused deposition modeling of plastic with the placement of continuous reinforcement enabled a honeycomb composite to be produced with higher specific properties than traditional composites. Thus, the current system demonstrated a greater capability of achieving ultimate gains in structural performance than previously possible.

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

Wang, Weina; Hellinga, Homme W.; Beese, Lorena S.

Even though high-fidelity polymerases copy DNA with remarkable accuracy, some base-pair mismatches are incorporated at low frequency, leading to spontaneous mutagenesis. Using high-resolution X-ray crystallographic analysis of a DNA polymerase that catalyzes replication in crystals, we observe that a C {center_dot} A mismatch can mimic the shape of cognate base pairs at the site of incorporation. This shape mimicry enables the mismatch to evade the error detection mechanisms of the polymerase, which would normally either prevent mismatch incorporation or promote its nucleolytic excision. Movement of a single proton on one of the mismatched bases alters the hydrogen-bonding pattern such thatmore » a base pair forms with an overall shape that is virtually indistinguishable from a canonical, Watson-Crick base pair in double-stranded DNA. These observations provide structural evidence for the rare tautomer hypothesis of spontaneous mutagenesis, a long-standing concept that has been difficult to demonstrate directly.« less

Melt-growth dynamics in CdTe crystals

DOE PAGES

Zhou, X. W.; Ward, D. K.; Wong, B. M.; ...

2012-06-01

We use a new, quantum-mechanics-based bond-order potential (BOP) to reveal melt growth dynamics and fine scale defect formation mechanisms in CdTe crystals. Previous molecular dynamics simulations of semiconductors have shown qualitatively incorrect behavior due to the lack of an interatomic potential capable of predicting both crystalline growth and property trends of many transitional structures encountered during the melt → crystal transformation. Here, we demonstrate successful molecular dynamics simulations of melt growth in CdTe using a BOP that significantly improves over other potentials on property trends of different phases. Our simulations result in a detailed understanding of defect formation during themore » melt growth process. Equally important, we show that the new BOP enables defect formation mechanisms to be studied at a scale level comparable to empirical molecular dynamics simulation methods with a fidelity level approaching quantum-mechanical methods.« less

Development and characteristics of Mechanical Porous Ambient Comet Simulants as comet surface analogs

NASA Astrophysics Data System (ADS)

Carey, Elizabeth M.; Peters, Gregory H.; Choukroun, Mathieu; Chu, Lauren; Carpenter, Emma; Cohen, Brooklin; Panossian, Lara; Zhou, Yu Meng; Sarkissian, Ani; Moreland, Scott; Shiraishi, Lori R.; Backes, Paul; Zacny, Kris; Green, Jacklyn R.; Raymond, Carol

2017-11-01

Comets are icy remnants of the Solar System formation, and as such contain some of the most primitive volatiles and organic materials. Sampling the surface of a comet is a high priority for the New Frontiers program. Planetary simulants are crucial to the development of adequate in situ instruments and sample acquisition systems. A high-fidelity comet surface simulant has been developed to support hardware design and development for one Comet Surface Sample Return tool, the BiBlade Comet Sampler. Mechanical Porous Ambient Comet Simulants (MPACS) can be manufactured to cover a wide range of desired physical properties, such as density and cone penetration resistance, and exhibit a brittle fracture mode. The structure of the MPACS materials is an aggregated composite structure of weakly-bonded grains of very small size (diameter ≤ 40 μm) that are most relevant to the structure of the surface of a comet nucleus.

Information theory-based algorithm for in silico prediction of PCR products with whole genomic sequences as templates.

PubMed

Cao, Youfang; Wang, Lianjie; Xu, Kexue; Kou, Chunhai; Zhang, Yulei; Wei, Guifang; He, Junjian; Wang, Yunfang; Zhao, Liping

2005-07-26

A new algorithm for assessing similarity between primer and template has been developed based on the hypothesis that annealing of primer to template is an information transfer process. Primer sequence is converted to a vector of the full potential hydrogen numbers (3 for G or C, 2 for A or T), while template sequence is converted to a vector of the actual hydrogen bond numbers formed after primer annealing. The former is considered as source information and the latter destination information. An information coefficient is calculated as a measure for fidelity of this information transfer process and thus a measure of similarity between primer and potential annealing site on template. Successful prediction of PCR products from whole genomic sequences with a computer program based on the algorithm demonstrated the potential of this new algorithm in areas like in silico PCR and gene finding.

Micromechanics of Composite Materials Governed by Vector Constitutive Laws

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Aboudi, Jacob; Arnold, Steven M.

2017-01-01

The high-fidelity generalized method of cells micromechanics theory has been extended for the prediction of the effective property tensor and the corresponding local field distributions for composites whose constituents are governed by vector constitutive laws. As shown, the shear analogy, which can predict effective transverse properties, is not valid in the general three-dimensional case. Consequently, a general derivation is presented that is applicable to both continuously and discontinuously reinforced composites with arbitrary vector constitutive laws and periodic microstructures. Results are given for thermal and electric problems, effective properties and local field distributions, ordered and random microstructures, as well as complex geometries including woven composites. Comparisons of the theory's predictions are made to test data, numerical analysis, and classical expressions from the literature. Further, classical methods cannot provide the local field distributions in the composite, and it is demonstrated that, as the percolation threshold is approached, their predictions are increasingly unreliable. XXXX It has been observed that the bonding between the fibers and matrix in composite materials can be imperfect. In the context of thermal conductivity, such imperfect interfaces have been investigated in micromechanical models by Dunn and Taya (1993), Duan and Karihaloo (2007), Nan et al. (1997) and Hashin (2001). The present HFGMC micromechanical method, derived for perfectly bonded composite materials governed by vector constitutive laws, can be easily generalized to include the effects of weak bonding between the constituents. Such generalizations, in the context of the mechanical micromechanics problem, involve introduction of a traction-separation law at the fiber/matrix interface and have been presented by Aboudi (1987), Bednarcyk and Arnold (2002), Bednarcyk et al. (2004) and Aboudi et al. (2013) and will be addressed in the future.

Leveraging routine clinical materials and mobile technology to assess CBT fidelity: the Innovative Methods to Assess Psychotherapy Practices (imAPP) study.

PubMed

Wiltsey Stirman, Shannon; Marques, Luana; Creed, Torrey A; Gutner, Cassidy A; DeRubeis, Robert; Barnett, Paul G; Kuhn, Eric; Suvak, Michael; Owen, Jason; Vogt, Dawne; Jo, Booil; Schoenwald, Sonja; Johnson, Clara; Mallard, Kera; Beristianos, Matthew; La Bash, Heidi

2018-05-22

Identifying scalable strategies for assessing fidelity is a key challenge in implementation science. However, for psychosocial interventions, the existing, reliable ways to test treatment fidelity quality are often labor intensive, and less burdensome strategies may not reflect actual clinical practice. Cognitive behavioral therapies (CBTs) provide clinicians with a set of effective core elements to help treat a multitude of disorders, which, evidence suggests, need to be delivered with fidelity to maximize potential client impact. The current "gold standard" for rating CBTs is rating recordings of therapy sessions, which is extremely time-consuming and requires a substantial amount of initial training. Although CBTs can vary based on the target disorder, one common element employed in most CBTs is the use of worksheets to identify specific behaviors and thoughts that affect a client's ability to recover. The present study will develop and evaluate an innovative new approach to rate CBT fidelity, by developing a universal CBT scoring system based on worksheets completed in therapy sessions. To develop a scoring system for CBT worksheets, we will compile common CBT elements from a variety of CBT worksheets for a range of psychiatric disorders and create adherence and competence measures. We will collect archival worksheets from past studies to test the scoring system and assess test-retest reliability. To evaluate whether CBT worksheet scoring accurately reflects clinician fidelity, we will recruit clinicians who are engaged in a CBT for depression, anxiety, and/or posttraumatic stress disorder. Clinicians and clients will transmit routine therapy materials produced in session (e.g., worksheets, clinical notes, session recordings) to the study team after each session. We will compare observer-rated fidelity, clinical notes, and fidelity-rated worksheets to identify the most effective and efficient method to assess clinician fidelity. Clients will also be randomly assigned to either complete the CBT worksheets on paper forms or on a mobile application (app) to learn if worksheet format influences clinician and client experience or differs in terms of reflecting fidelity. Scoring fidelity using CBT worksheets may allow clinics to test fidelity in a short and effective manner, enhancing continuous quality improvement in the workplace. Clinicians and clinics can use such data to improve clinician fidelity in real time, leading to improved patient outcomes. ClinicalTrials.gov NCT03479398 . Retrospectively registered March 20, 2018.

A modified theoretical framework to assess implementation fidelity of adaptive public health interventions.

PubMed

Pérez, Dennis; Van der Stuyft, Patrick; Zabala, Maríadel Carmen; Castro, Marta; Lefèvre, Pierre

2016-07-08

One of the major debates in implementation research turns around fidelity and adaptation. Fidelity is the degree to which an intervention is implemented as intended by its developers. It is meant to ensure that the intervention maintains its intended effects. Adaptation is the process of implementers or users bringing changes to the original design of an intervention. Depending on the nature of the modifications brought, adaptation could either be potentially positive or could carry the risk of threatening the theoretical basis of the intervention, resulting in a negative effect on expected outcomes. Adaptive interventions are those for which adaptation is allowed or even encouraged. Classical fidelity dimensions and conceptual frameworks do not address the issue of how to adapt an intervention while still maintaining its effectiveness. We support the idea that fidelity and adaptation co-exist and that adaptations can impact either positively or negatively on the intervention's effectiveness. For adaptive interventions, research should answer the question how an adequate fidelity-adaptation balance can be reached. One way to address this issue is by looking systematically at the aspects of an intervention that are being adapted. We conducted fidelity research on the implementation of an empowerment strategy for dengue prevention in Cuba. In view of the adaptive nature of the strategy, we anticipated that the classical fidelity dimensions would be of limited use for assessing adaptations. The typology we used in the assessment-implemented, not-implemented, modified, or added components of the strategy-also had limitations. It did not allow us to answer the question which of the modifications introduced in the strategy contributed to or distracted from outcomes. We confronted our empirical research with existing literature on fidelity, and as a result, considered that the framework for implementation fidelity proposed by Carroll et al. in 2007 could potentially meet our concerns. We propose modifications to the framework to assess both fidelity and adaptation. The modified Carroll et al.'s framework we propose may permit a comprehensive assessment of the implementation fidelity-adaptation balance required when implementing adaptive interventions, but more empirical research is needed to validate it.

First-Principles Study of Mo Segregation in MoNi(111): Effects of Chemisorbed Atomic Oxygen

PubMed Central

Yu, Yanlin; Xiao, Wei; Wang, Jianwei; Wang, Ligen

2015-01-01

Segregation at metal alloy surfaces is an important issue because many electrochemical and catalytic properties are directly correlated to the surface composition. We have performed density functional theory calculations for Mo segregation in MoNi(111) in the presence of chemisorbed atomic oxygen. In particular, the coverage dependence and possible adsorption-induced segregation phenomena are addressed by investigating segregation energies of the Mo atom in MoNi(111). The theoretical calculated results show that the Mo atom prefers to be embedded in the bulk for the clean MoNi(111), while it segregates to the top-most layer when the oxygen coverage is thicker than 1/9 monolayer (ML). Furthermore, we analyze the densities of states for the clean and oxygen-chemisorbed MoNi(111), and see a strong covalent bonding between Mo d-band states and O p-states. The present study provides valuable insight for exploring practical applications of Ni-based alloys as hydrogen evolution electrodes. PMID:28787811

Fullerene-derivative PC61BM forms three types of phase-pure monolayer on the surface of Au(111)

NASA Astrophysics Data System (ADS)

Li, Wen-Jie; Du, Ying-Ying; Zhang, Han-Jie; Chen, Guang-Hua; Sheng, Chun-Qi; Wu, Rui; Wang, Jia-Ou; Qian, Hai-Jie; Ibrahim, Kurash; He, Pi-Mo; Li, Hong-Nian

2016-12-01

We have studied the packing structures of C60-derivative PC61BM on the surface of Au(111) in ultrahigh vacuum using scanning tunneling microscopy. The Au(111) has a triangle-like reconstructed surface, which results in some packing structures different from those reported for low coverages. PC61BM can form three types of phase-pure monolayer, namely, the compact straight molecular double-row monolayer, the hexagonal-packing monolayer and the glassy monolayer. The different types of monolayer form for different molecular densities and different annealing temperatures. In addition to the already known inter-molecular interactions (Van de Waals interaction and hydrogen bond), the steric effect of the phenyl-butyric-acid-methyl-ester side tail plays conspicuous role in the molecular self-assembly at high coverages. The steric effect makes it difficult to prepare a hexagonal-packing monolayer at room temperature and decides the instability of the hexagonal-packing monolayer prepared by thermal annealing.

Doping reaction of PH3 and B2H6 with Si(100)

NASA Astrophysics Data System (ADS)

Yu, Ming L.; Vitkavage, D. J.; Meyerson, B. S.

1986-06-01

The reaction of phosphine PH3 and diborane B2H6 on Si(100) surfaces was studied by surface analytical techniques in relation to the in situ doping process in the chemical vapor deposition of silicon. Phosphine chemisorbs readily either nondissociatively at room temperature or dissociatively with the formation of silicon-hydrogen bonds at higher temperatures. Hydrogen can be desorbed at temperatures above 400 °C to generate a phosphorus layer. Phosphorus is not effective in shifting the Fermi level until the coverage reaches 2×1014/cm2. A maximum shift of 0.45 eV toward the conduction band was observed. In contrast, diborane has a very small sticking coefficient and the way to deposit boron is to decompose diborane directly on the silicon surface at temperatures above 600 °C. Boron at coverages less than 2×1014/cm2 is very effective in shifting the Fermi level toward the valence band and a maximum change of 0.4 eV was observed.

Hindered rotation and nuclear spin isomers separation of molecularly chemisorbed H2 on Pd(210)

NASA Astrophysics Data System (ADS)

Arguelles, Elvis F.; Kasai, Hideaki

2018-03-01

We investigated the hindered rotation and nuclear spin isomer separation of H2 on Pd(210) for various pre-adsorbed atomic hydrogen coverages (Θ), by total energy calculations based on density functional theory. Our results revealed that H2 is in the molecularly chemisorbed state and the adsorption is characterized by a highly anisotropic potential energy surface. Further, we found that J = 1 degenerate level splitting is insensitive to the increase in Θ from 1 to 2 ML. This is due to the comparable potential strengths hindering/restricting the polar rotations in both coverages. On a fully H passivated (3 ML) Pd(210), H2 is in a weakly physisorbed state with a negligible potential anisotropy. Our findings suggest that the activation barrier for polar rotational motion does not strongly depend on the adsorption energy but rather on the surface-molecule bond. The estimated rotational state desorption energies show a separation of ortho and para isomers by around 7.0 meV.

Tantalum induced butterfly-like clusters on Si (111)-7 × 7 surface: STM/STS study at low coverage

NASA Astrophysics Data System (ADS)

Shukrynau, Pavel; Mutombo, Pingo; Švec, Martin; Hietschold, Michael; Cháb, Vladimír

2012-02-01

The adsorption of the small amounts of tantalum on Si (111)-7 × 7 reconstructed surface is investigated systematically using scanning tunneling microscopy and tunneling spectroscopy combined with first-principles density functional theory calculations. We find out that the moderate annealing of the Ta covered surface results in the formation of clusters of the butterfly-like shape. The clusters are sporadically distributed over the surface and their density is metal coverage dependent. Filled and empty state STM images of the clusters differ strongly suggesting the existence of covalent bonds within the cluster. Tunneling spectroscopy measurements reveal small energy gap, showing semiconductor-like behavior of the constituent atoms. The cluster model based on experimental images and theoretical calculations has been proposed and discussed. Presented results show that Ta joins the family of adsorbates, that are known to form magic clusters on Si (111)-7 × 7, but its magic cluster has the structural and electronic properties that are different from those reported before.

Ru sub 3 (CO) sub 12 and Mo(CO) sub 6 adsorbed on Ru(001) and Au/Ru: An infrared reflection-absorption study

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

Malik, I.J.; Hrbek, J.

1990-01-01

The authors obtained infrared reflection absorption (IRAS) and thermal desorption spectroscopy (TDS) data for Ru{sub 3}(CO){sub 12}/Ru(001) and Mo(CO){sub 6}/Au/Ru systems for metal carbonyl coverages between submonolayer and approximately 20 monolayers. They characterized the C-O stretching mode of both systems (4cm{sup {minus}1}FWHM) and a deformation mode of Mo(CO){sub 6} at 608cm{sup {minus}1} (1 cm{sup {minus}1}FWHM). Both IRAS and TDS data suggest adsorption and desorption of metal carbonyls as molecular species with a preferential orientation in the overlayers. The IR intensity of the C-O stretch per a C-O bond projected onto the surface normal is approximately twice (five times) larger formore » Ru{sub 3}(CO){sub 12} (Mo(CO){sub 6}) at submonolayer coverages than for CO/Ru(001) at {theta}{sub CO}=0.68.« less

Ru sub 3 (CO) sub 12 and Mo(CO) sub 6 adsorbed on Ru(001) and Au/Ru: An infrared reflection-absorption study

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

Malik, I.J.; Hrbek, J.

1990-01-01

We obtained IRAS and TDS data for Ru{sub 3}(CO){sub 12}/Ru(001) and Mo(CO){sub 6}/Au/Ru systems for metal carbonyl coverages between submonolayer and approximately 20 monolayers. We characterized the C-O stretching mode of both systems (4 cm{sup {minus}1} FWHM) and a deformation mode of Mo(CO){sub 6} at 608 cm{sup {minus}1} (1 cm{sup {minus}1} FWHM). Both IRAS and TDS data suggest adsorption and desorption of metal carbonyls as molecular species with a preferential orientation in the overlayers. The IR intensity of the C-O stretch per a C-O bond projected onto the surface normal is approximately twice (five times) larger for Ru{sub 3}(CO){sub 12}more » (Mo(CO){sub 6}) at submonolayer coverages than for CO/Ru(001) at {theta}{sub CO}=0.68. 31 refs., 4 figs.« less

Measuring Implementation Fidelity in a Community-Based Parenting Intervention

PubMed Central

Breitenstein, Susan M.; Fogg, Louis; Garvey, Christine; Hill, Carri; Resnick, Barbara; Gross, Deborah

2012-01-01

Background Establishing the feasibility and validity of implementation fidelity monitoring strategies is an important methodological step in implementing evidence-based interventions on a large scale. Objectives The objective of the study was to examine the reliability and validity of the Fidelity Checklist, a measure designed to assess group leader adherence and competence delivering a parent training intervention (the Chicago Parent Program) in child care centers serving low-income families. Method The sample included 9 parent groups (12 group sessions each), 12 group leaders, and 103 parents. Independent raters reviewed 106 audiotaped parent group sessions and coded group leaders’ fidelity on the Adherence and Competence Scales of the Fidelity Checklist. Group leaders completed self-report adherence checklists and a measure of parent engagement in the intervention. Parents completed measures of consumer satisfaction and child behavior. Results High interrater agreement (Adherence Scale = 94%, Competence Scale = 85%) and adequate intraclass correlation coefficients (Adherence Scale = .69, Competence Scale = .91) were achieved for the Fidelity Checklist. Group leader adherence changed over time, but competence remained stable. Agreement between group leader self-report and independent ratings on the Adherence Scale was 85%; disagreements were more frequently due to positive bias in group leader self-report. Positive correlations were found between group leader adherence and parent attendance and engagement in the intervention and between group leader competence and parent satisfaction. Although child behavior problems improved, improvements were not related to fidelity. Discussion The results suggest that the Fidelity Checklist is a feasible, reliable, and valid measure of group leader implementation fidelity in a group-based parenting intervention. Future research will be focused on testing the Fidelity Checklist with diverse and larger samples and generalizing to other group-based interventions using a similar intervention model. PMID:20404777

The interface of SrTiO3 and H2O from density functional theory molecular dynamics

PubMed Central

Spijker, P.; Foster, A. S.

2016-01-01

We use dispersion-corrected density functional theory molecular dynamics simulations to predict the ionic, electronic and vibrational properties of the SrTiO3/H2O solid–liquid interface. Approximately 50% of surface oxygens on the planar SrO termination are hydroxylated at all studied levels of water coverage, the corresponding number being 15% for the planar TiO2 termination and 5% on the stepped TiO2-terminated surface. The lateral ordering of the hydration structure is largely controlled by covalent-like surface cation to H2O bonding and surface corrugation. We find a featureless electronic density of states in and around the band gap energy region at the solid–liquid interface. The vibrational spectrum indicates redshifting of the O–H stretching band due to surface-to-liquid hydrogen bonding and blueshifting due to high-frequency stretching vibrations of OH fragments within the liquid, as well as strong suppression of the OH stretching band on the stepped surface. We find highly varying rates of proton transfer above different SrTiO3 surfaces, owing to differences in hydrogen bond strength and the degree of dissociation of incident water. Trends in proton dynamics and the mode of H2O adsorption among studied surfaces can be explained by the differential ionicity of the Ti–O and Sr–O bonds in the SrTiO3 crystal. PMID:27713660

Treatment Fidelity Among Family Health Promoters Delivering a Physical Activity and Nutrition Intervention to Immigrant and Refugee Families.

PubMed

Bronars, Carrie A; Hanza, Marcelo M; Meiers, Sonja J; Patten, Christi A; Clark, Matthew M; Nigon, Julie A; Weis, Jennifer A; Wieland, Mark L; Sia, Irene G

2017-04-01

Lack of treatment fidelity can be an important source of variation affecting the credibility and utility of outcomes from behavioral intervention research. Development and implementation of a well-designed treatment fidelity plan, especially with research involving underserved populations, requires careful conceptualization of study needs in conjunction with what is feasible in the population. The purpose of this article is to review a fidelity-monitoring plan consistent with the National Institutes of Health Behavior Change Consortium guidelines (e.g., design, training, delivery, receipt, and enactment) for an intervention trial designed to improve physical activity and nutrition among immigrant and refugee families. Description of the fidelity monitoring plan is provided and challenges related to monitoring treatment fidelity in a community-based participatory intervention for immigrant and refugee families are discussed.

Time to unravel the conceptual confusion of authenticity and fidelity and their contribution to learning within simulation-based nurse education. A discussion paper.

PubMed

Bland, Andrew J; Topping, Annie; Tobbell, Jane

2014-07-01

High-fidelity patient simulation is a method of education increasingly utilised by educators of nursing to provide authentic learning experiences. Fidelity and authenticity, however, are not conceptually equivalent. Whilst fidelity is important when striving to replicate a life experience such as clinical practice, authenticity can be produced with low fidelity. A challenge for educators of undergraduate nursing is to ensure authentic representation of the clinical situation which is a core component for potential success. What is less clear is the relationship between fidelity and authenticity in the context of simulation based learning. Authenticity does not automatically follow fidelity and as a result, educators of nursing cannot assume that embracing the latest technology-based educational tools will in isolation provide a learning environment perceived authentic by the learner. As nursing education programmes increasingly adopt simulators that offer the possibility of representing authentic real world situations, there is an urgency to better articulate and understand the terms fidelity and authenticity. Without such understanding there is a real danger that simulation as a teaching and learning resource in nurse education will never reach its potential and be misunderstood, creating a potential barrier to learning. This paper examines current literature to promote discussion within nurse education, concluding that authenticity in the context of simulation-based learning is complex, relying on far more than engineered fidelity. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Effect of Interfacial Chemical Bonding in TiO2-SiO2 Composites on Their Photocatalytic NOx Abatement Performance

PubMed Central

Hakki, Amer; Yang, Lu; Wang, Fazhou; Macphee, Donald E.

2017-01-01

The chemical bonding of particulate photocatalysts to supporting material surfaces is of great importance in engineering more efficient and practical photocatalytic structures. However, the influence of such chemical bonding on the optical and surface properties of the photocatalyst and thus its photocatalytic activity/reaction selectivity behavior has not been systematically studied. In this investigation, TiO2 has been supported on the surface of SiO2 by means of two different methods: (i) by the in situ formation of TiO2 in the presence of sand quartz via a sol-gel method employing tetrabutyl orthotitanium (TBOT); and (ii) by binding the commercial TiO2 powder to quartz on a surface silica gel layer formed from the reaction of quartz with tetraethylorthosilicate (TEOS). For comparison, TiO2 nanoparticles were also deposited on the surfaces of a more reactive SiO2 prepared by a hydrolysis-controlled sol-gel technique as well as through a sol-gel route from TiO2 and SiO2 precursors. The combination of TiO2 and SiO2, through interfacial Ti-O-Si bonds, was confirmed by FTIR spectroscopy and the photocatalytic activities of the obtained composites were tested for photocatalytic degradation of NO according to the ISO standard method (ISO 22197−1). The electron microscope images of the obtained materials showed that variable photocatalyst coverage of the support surface can successfully be achieved but the photocatalytic activity towards NO removal was found to be affected by the preparation method and the nitrate selectivity is adversely affected by Ti-O-Si bonding. PMID:28715384

High-Fidelity Simulations of Electromagnetic Propagation and RF Communication Systems

DTIC Science & Technology

2017-05-01

addition to high -fidelity RF propagation modeling, lower-fidelity mod- els, which are less computationally burdensome, are available via a C++ API...expensive to perform, requiring roughly one hour of computer time with 36 available cores and ray tracing per- formed by a single high -end GPU...ER D C TR -1 7- 2 Military Engineering Applied Research High -Fidelity Simulations of Electromagnetic Propagation and RF Communication

Fidelity decay of the two-level bosonic embedded ensembles of random matrices

NASA Astrophysics Data System (ADS)

Benet, Luis; Hernández-Quiroz, Saúl; Seligman, Thomas H.

2010-12-01

We study the fidelity decay of the k-body embedded ensembles of random matrices for bosons distributed over two single-particle states. Fidelity is defined in terms of a reference Hamiltonian, which is a purely diagonal matrix consisting of a fixed one-body term and includes the diagonal of the perturbing k-body embedded ensemble matrix, and the perturbed Hamiltonian which includes the residual off-diagonal elements of the k-body interaction. This choice mimics the typical mean-field basis used in many calculations. We study separately the cases k = 2 and 3. We compute the ensemble-averaged fidelity decay as well as the fidelity of typical members with respect to an initial random state. Average fidelity displays a revival at the Heisenberg time, t = tH = 1, and a freeze in the fidelity decay, during which periodic revivals of period tH are observed. We obtain the relevant scaling properties with respect to the number of bosons and the strength of the perturbation. For certain members of the ensemble, we find that the period of the revivals during the freeze of fidelity occurs at fractional times of tH. These fractional periodic revivals are related to the dominance of specific k-body terms in the perturbation.

Enhancing treatment fidelity in psychotherapy research: novel approach to measure the components of cognitive behavioural therapy for relapse prevention in first-episode psychosis.

PubMed

Alvarez-Jimenez, Mario; Wade, Darryl; Cotton, Sue; Gee, Donna; Pearce, Tracey; Crisp, Kingsley; McGorry, Patrick D; Gleeson, John F

2008-12-01

Establishing treatment fidelity is one of the most important aspects of psychotherapy research. Treatment fidelity refers to the methodological strategies used to examine and enhance the reliability and validity of psychotherapy. This study sought to develop and evaluate a measure specifically designed to assess fidelity to the different therapeutic components (i.e. therapy phases) of the individual intervention of a psychotherapy clinical trial (the EPISODE II trial). A representative sample of sessions stratified by therapy phase was assessed using a specifically developed fidelity measure (Relapse Prevention Therapy-Fidelity Scale, RPT-FS). Each RPT-FS subscale was designed to include a different component/phase of therapy and its major therapeutic ingredients. The measure was found to be reliable and had good internal consistency. The RPT-FS discriminated, almost perfectly, between therapy phases. The analysis of the therapeutic strategies implemented during the intervention indicated that treatment fidelity was good throughout therapy phases. While therapists primarily engaged in interventions from the appropriate therapeutic phase, flexibility in therapy was evident. This study described the development of a brief, reliable and internally consistent measure to determine both treatment fidelity and the therapy components implemented throughout the intervention. This methodology can be potentially useful to determine those components related to therapeutic change.

Measuring trainer fidelity in the transfer of suicide prevention training

PubMed Central

Cross, Wendi F.; Pisani, Anthony R.; Schmeelk-Cone, Karen; Xia, Yinglin; Tu, Xin; McMahon, Marcie; Munfakh, Jimmie Lou; Gould, Madelyn S.

2014-01-01

Background Finding effective and efficient models to train large numbers of suicide prevention interventionists, including ‘hotline’ crisis counselors, is a high priority. Train-the-trainer (TTT) models are widely used but understudied. Aims To assess the extent to which trainers following TTT delivered the Applied Suicide Intervention Skills Training (ASIST) program with fidelity, and to examine fidelity across two trainings and seven training segments. Methods We recorded and reliably rated trainer fidelity, defined as adherence to program content and competence of program delivery, for 34 newly trained ASIST trainers delivering the program to crisis center staff on two separate occasions. A total of 324 observations were coded. Trainer demographics were also collected. Results On average, trainers delivered two-thirds of the program. Previous training was associated with lower levels of trainer adherence to the program. 18% of trainers' observations were rated as solidly competent. Trainers did not improve fidelity from their first to second training. Significantly higher fidelity was found for lectures and lower fidelity was found for interactive training activities including asking about suicide and creating a safe plan. Conclusions We found wide variability in trainer fidelity to the ASIST program following TTT and few trainers had high levels of both adherence and competence. More research is needed to examine the cost-effectiveness of TTT models. PMID:24901061

Systematic evaluation of implementation fidelity of complex interventions in health and social care

PubMed Central

2010-01-01

Background Evaluation of an implementation process and its fidelity can give insight into the 'black box' of interventions. However, a lack of standardized methods for studying fidelity and implementation process have been reported, which might be one reason for the fact that few prior studies in the field of health service research have systematically evaluated interventions' implementation processes. The aim of this project is to systematically evaluate implementation fidelity and possible factors influencing fidelity of complex interventions in health and social care. Methods A modified version of The Conceptual Framework for Implementation Fidelity will be used as a conceptual model for the evaluation. The modification implies two additional moderating factors: context and recruitment. A systematic evaluation process was developed. Multiple case study method is used to investigate implementation of three complex health service interventions. Each case will be investigated in depth and longitudinally, using both quantitative and qualitative methods. Discussion This study is the first attempt to empirically test The Conceptual Framework for Implementation Fidelity. The study can highlight mechanism and factors of importance when implementing complex interventions. Especially the role of the moderating factors on implementation fidelity can be clarified. Trial Registration Supported Employment, SE, among people with severe mental illness -- a randomized controlled trial: NCT00960024. PMID:20815872

Quantum state tomography and fidelity estimation via Phaselift

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

Lu, Yiping; Liu, Huan; Zhao, Qing, E-mail: qzhaoyuping@bit.edu.cn

Experiments of multi-photon entanglement have been performed by several groups. Obviously, an increase on the photon number for fidelity estimation and quantum state tomography causes a dramatic increase in the elements of the positive operator valued measures (POVMs), which results in a great consumption of time in measurements. In practice, we wish to obtain a good estimation of fidelity and quantum states through as few measurements as possible for multi-photon entanglement. Phaselift provides such a chance to estimate fidelity for entangling states based on less data. In this paper, we would like to show how the Phaselift works for sixmore » qubits in comparison to the data given by Pan’s group, i.e., we use a fraction of the data as input to estimate the rest of the data through the obtained density matrix, and thus goes beyond the simple fidelity analysis. The fidelity bound is also provided for general Schrödinger Cat state. Based on the fidelity bound, we propose an optimal measurement approach which could both reduce the copies and keep the fidelity bound gap small. The results demonstrate that the Phaselift can help decrease the measured elements of POVMs for six qubits. Our conclusion is based on the prior knowledge that a pure state is the target state prepared by experiments.« less

The Need for High Fidelity Lunar Regolith Simulants

NASA Technical Reports Server (NTRS)

Gaier, James R.

2007-01-01

The case is made for the need to have high fidelity lunar regolith simulants to verify the performance of structures and mechanisms to be used on the lunar surface. Minor constituents will in some cases have major consequences. Small amounts of sulfur in the regolith can poison catalysts, and metallic iron on the surface of nano-sized dust particles may cause a dramatic increase in its toxicity. So the definition of a high fidelity simulant is application dependent. For example, in situ resource utilization will require high fidelity in chemistry, meaning careful attention to the minor components and phases; but some other applications, such as the abrasive effects on suit fabrics, might be relatively insensitive to minor component chemistry. The lunar environment itself will change the surface chemistry of the simulant, so to have a high fidelity simulant at must be used in a high fidelity simulated environment to get a high fidelity simulation. Research must be conducted to determine how sensitive technologies will be to minor components and environmental factors before they can be dismissed as unimportant.

The Relationship Between Fidelity and Learning in Aviation Training and Assessment

NASA Technical Reports Server (NTRS)

Noble, Cliff

2002-01-01

Flight simulators can be designed to train pilots or assess their flight performance. Low-Fidelity simulators maximize the initial learning rate of novice pilots and minimize initial costs; whereas, expensive, high-fidelity simulators predict the realworld in-flight performance of expert pilots (Fink & Shriver, 1978 Hays & Singer 1989; Kinkade & Wheaton. 1972). Although intuitively appealing and intellectually convenient to generalize concepts of learning and assessment, what holds true for the role of fidelity in assessment may not always hold true for learning, and vice versa. To bring clarity to this issue, the author distinguishes the role of fidelity in learning from its role in assessment as a function of skill level by applying the hypothesis of Alessi (1988) and reviewing the Laughery, Ditzian, and Houtman (1982) study on simulator validity. Alessi hypothesized that there is it point beyond which one additional unit of flight-simulator fidelity results in a diminished rate of learning. The author of this current paper also suggests the existence of an optimal point beyond which one additional unit of flight-simulator fidelity results in a diminished rate of practical assessment of nonexpert pilot performance.

Foot-and-mouth disease virus type O specific mutations determine RNA-dependent RNA polymerase fidelity and virus attenuation.

PubMed

Li, Chen; Wang, Haiwei; Yuan, Tiangang; Woodman, Andrew; Yang, Decheng; Zhou, Guohui; Cameron, Craig E; Yu, Li

2018-05-01

Previous studies have shown that the FMDV Asia1/YS/CHA/05 high-fidelity mutagen-resistant variants are attenuated (Zeng et al., 2014). Here, we introduced the same single or multiple-amino-acid substitutions responsible for increased 3D pol fidelity of type Asia1 FMDV into the type O FMDV O/YS/CHA/05 infectious clone. The rescued viruses O-DA and O-DAMM are lower replication fidelity mutants and showed an attenuated phenotype. These results demonstrated that the same amino acid substitution of 3D pol in different serotypes of FMDV strains had different effects on viral fidelity. In addition, nucleoside analogues were used to select high-fidelity mutagen-resistant type O FMDV variants. The rescued mutagen-resistant type O FMDV high-fidelity variants exhibited significantly attenuated fitness and a reduced virulence phenotype. These results have important implications for understanding the molecular mechanism of FMDV evolution and pathogenicity, especially in developing a safer modified live-attenuated vaccine against FMDV. Copyright © 2018 Elsevier Inc. All rights reserved.

Within-subjects comparison of the HiRes and Fidelity120 speech processing strategies: speech perception and its relation to place-pitch sensitivity.

PubMed

Donaldson, Gail S; Dawson, Patricia K; Borden, Lamar Z

2011-01-01

Previous studies have confirmed that current steering can increase the number of discriminable pitches available to many cochlear implant (CI) users; however, the ability to perceive additional pitches has not been linked to improved speech perception. The primary goals of this study were to determine (1) whether adult CI users can achieve higher levels of spectral cue transmission with a speech processing strategy that implements current steering (Fidelity120) than with a predecessor strategy (HiRes) and, if so, (2) whether the magnitude of improvement can be predicted from individual differences in place-pitch sensitivity. A secondary goal was to determine whether Fidelity120 supports higher levels of speech recognition in noise than HiRes. A within-subjects repeated measures design evaluated speech perception performance with Fidelity120 relative to HiRes in 10 adult CI users. Subjects used the novel strategy (either HiRes or Fidelity120) for 8 wks during the main study; a subset of five subjects used Fidelity120 for three additional months after the main study. Speech perception was assessed for the spectral cues related to vowel F1 frequency, vowel F2 frequency, and consonant place of articulation; overall transmitted information for vowels and consonants; and sentence recognition in noise. Place-pitch sensitivity was measured for electrode pairs in the apical, middle, and basal regions of the implanted array using a psychophysical pitch-ranking task. With one exception, there was no effect of strategy (HiRes versus Fidelity120) on the speech measures tested, either during the main study (N = 10) or after extended use of Fidelity120 (N = 5). The exception was a small but significant advantage for HiRes over Fidelity120 for consonant perception during the main study. Examination of individual subjects' data revealed that 3 of 10 subjects demonstrated improved perception of one or more spectral cues with Fidelity120 relative to HiRes after 8 wks or longer experience with Fidelity120. Another three subjects exhibited initial decrements in spectral cue perception with Fidelity120 at the 8-wk time point; however, evidence from one subject suggested that such decrements may resolve with additional experience. Place-pitch thresholds were inversely related to improvements in vowel F2 frequency perception with Fidelity120 relative to HiRes. However, no relationship was observed between place-pitch thresholds and the other spectral measures (vowel F1 frequency or consonant place of articulation). Findings suggest that Fidelity120 supports small improvements in the perception of spectral speech cues in some Advanced Bionics CI users; however, many users show no clear benefit. Benefits are more likely to occur for vowel spectral cues (related to F1 and F2 frequency) than for consonant spectral cues (related to place of articulation). There was an inconsistent relationship between place-pitch sensitivity and improvements in spectral cue perception with Fidelity120 relative to HiRes. This may partly reflect the small number of sites at which place-pitch thresholds were measured. Contrary to some previous reports, there was no clear evidence that Fidelity120 supports improved sentence recognition in noise.

Molecular dynamics and mutational analysis of the catalytic and translocation cycle of RNA polymerase

PubMed Central

2012-01-01

Background During elongation, multi-subunit RNA polymerases (RNAPs) cycle between phosphodiester bond formation and nucleic acid translocation. In the conformation associated with catalysis, the mobile “trigger loop” of the catalytic subunit closes on the nucleoside triphosphate (NTP) substrate. Closing of the trigger loop is expected to exclude water from the active site, and dehydration may contribute to catalysis and fidelity. In the absence of a NTP substrate in the active site, the trigger loop opens, which may enable translocation. Another notable structural element of the RNAP catalytic center is the “bridge helix” that separates the active site from downstream DNA. The bridge helix may participate in translocation by bending against the RNA/DNA hybrid to induce RNAP forward movement and to vacate the active site for the next NTP loading. The transition between catalytic and translocation conformations of RNAP is not evident from static crystallographic snapshots in which macromolecular motions may be restrained by crystal packing. Results All atom molecular dynamics simulations of Thermus thermophilus (Tt) RNAP reveal flexible hinges, located within the two helices at the base of the trigger loop, and two glycine hinges clustered near the N-terminal end of the bridge helix. As simulation progresses, these hinges adopt distinct conformations in the closed and open trigger loop structures. A number of residues (described as “switch” residues) trade atomic contacts (ion pairs or hydrogen bonds) in response to changes in hinge orientation. In vivo phenotypes and in vitro activities rendered by mutations in the hinge and switch residues in Saccharomyces cerevisiae (Sc) RNAP II support the importance of conformational changes predicted from simulations in catalysis and translocation. During simulation, the elongation complex with an open trigger loop spontaneously translocates forward relative to the elongation complex with a closed trigger loop. Conclusions Switching between catalytic and translocating RNAP forms involves closing and opening of the trigger loop and long-range conformational changes in the atomic contacts of amino acid side chains, some located at a considerable distance from the trigger loop and active site. Trigger loop closing appears to support chemistry and the fidelity of RNA synthesis. Trigger loop opening and limited bridge helix bending appears to promote forward nucleic acid translocation. PMID:22676913

From ab Initio Potential Energy Surfaces to State-Resolved Reactivities: X + H 2O ↔ HX + OH [X = F, Cl, and O( 3P)] Reactions

DOE PAGES

Li, Jun; Jiang, Bin; Song, Hongwei; ...

2015-04-17

Here, we survey the recent advances in theoretical understanding of quantum state resolved dynamics, using the title reactions as examples. It is shown that the progress was made possible by major developments in two areas. First, an accurate analytical representation of many high-level ab initio points over a large configuration space can now be made with high fidelity and the necessary permutation symmetry. The resulting full-dimensional global potential energy surfaces enable dynamical calculations using either quasi-classical trajectory or more importantly quantum mechanical methods. The second advance is the development of accurate and efficient quantum dynamical methods, which are necessary formore » providing a reliable treatment of quantum effects in reaction dynamics such as tunneling, resonances, and zero-point energy. The powerful combination of the two advances has allowed us to achieve a quantitatively accurate characterization of the reaction dynamics, which unveiled rich dynamical features such as steric steering, strong mode specificity, and bond selectivity. The dependence of reactivity on reactant modes can be rationalized by the recently proposed sudden vector projection model, which attributes the mode specificity and bond selectivity to the coupling of reactant modes with the reaction coordinate at the relevant transition state. The deeper insights provided by these theoretical studies have advanced our understanding of reaction dynamics to a new level.« less

Fidelity of Simulation for Pilot Training

DTIC Science & Technology

1980-12-01

is worthwhile emphasizing at this point that the study is focused on fidelity of simulators for pilot training. It does not consider simulation for...significantly higher cost than low fidelity. Motivation for 0~is study is to obtain background information on the effect of simulator fidel- ity on ...bottom of the diagram is the recom- mended approach. In practice, however, it is often the case that emphasis is placed on work in the bottom segment of

Application of the no-signaling principle to obtain quantum cloners for any allowed value of fidelity

NASA Astrophysics Data System (ADS)

Gedik, Z.; Çakmak, B.

2013-04-01

Special relativity forbids superluminal influences. Using only the no-signaling principle and an assumption about the form of the Schmidt decomposition, we show that for any allowed fidelity there is a unique approximate qubit cloner which can be written explicitly. We introduce the prime cloners whose fidelities have multiplicative property and show that the fidelity of the prime cloners for the infinite copy limit is 1/2.

An empirical study of multidimensional fidelity of COMPASS consultation.

PubMed

Wong, Venus; Ruble, Lisa A; McGrew, John H; Yu, Yue

2018-06-01

Consultation is essential to the daily practice of school psychologists (National Association of School Psychologist, 2010). Successful consultation requires fidelity at both the consultant (implementation) and consultee (intervention) levels. We applied a multidimensional, multilevel conception of fidelity (Dunst, Trivette, & Raab, 2013) to a consultative intervention called the Collaborative Model for Promoting Competence and Success (COMPASS) for students with autism. The study provided 3 main findings. First, multidimensional, multilevel fidelity is a stable construct and increases over time with consultation support. Second, mediation analyses revealed that implementation-level fidelity components had distant, indirect effects on student Individualized Education Program (IEP) outcomes. Third, 3 fidelity components correlated with IEP outcomes: teacher coaching responsiveness at the implementation level, and teacher quality of delivery and student responsiveness at the intervention levels. Implications and future directions are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Generation and applications of an ultrahigh-fidelity four-photon Greenberger-Horne-Zeilinger state.

PubMed

Zhang, Chao; Huang, Yun-Feng; Zhang, Cheng-Jie; Wang, Jian; Liu, Bi-Heng; Li, Chuan-Feng; Guo, Guang-Can

2016-11-28

High-quality entangled photon pairs generated via spontaneous parametric down-conversion have made great contributions to the modern quantum information science and the fundamental tests of quantum mechanics. However, the quality of the entangled states decreases sharply when moving from biphoton to multiphoton experiments, mainly due to the lack of interactions between photons. Here, for the first time, we generate a four-photon Greenberger-Horne-Zeilinger state with a fidelity of 98%, which is even comparable to the best fidelity of biphoton entangled states. Thus, it enables us to demonstrate an ultrahigh-fidelity entanglement swapping-the key ingredient in various quantum information tasks. Our results push the fidelity of multiphoton entanglement generation to a new level and would be useful in some demanding tasks, e.g., we successfully demonstrate the genuine multipartite nonlocality of the observed state in the nonsignaling scenario by violating a novel Hardy-like inequality, which requires very high state-fidelity.

Challenges of Applying a Comprehensive Model of Intervention Fidelity

PubMed Central

Bosak, Kelly; Pozehl, Bunny; Yates, Bernice

2014-01-01

Applying a comprehensive model of fidelity to interventions delivered by Information and Communication Technology (ICT) has multiple challenges. Fidelity must be considered in the design, implementation, evaluation, and reporting of the intervention. The fidelity strategies must address the unique aspects of the technology, including training providers to instruct participants to use the technology and to provide standardized feedback, rather than deliver the intervention in-person. Other challenges include the nonspecific effects resulting from participants accessing unintended content in interventions delivered by the Internet. ICT allows participant receipt and enactment of intervention skills to be assessed by electronic evidence, rather than in-person observation. Interventions using ICT, such as the Internet are unique, and there is less control of participant interaction with various electronic components. Monitoring participant use and providing standardized feedback for receipt and enactment of intervention skills is key to ensuring intervention fidelity. The final challenges involve evaluating and reporting fidelity. PMID:21474676

Collisional entanglement fidelities in quantum plasmas including strong quantum recoil and oscillation effects

NASA Astrophysics Data System (ADS)

Lee, Myoung-Jae; Jung, Young-Dae

2017-10-01

The quantum recoil and oscillation effects on the entanglement fidelity and the electron-exchange function for the electron-ion collision are investigated in a semiconductor plasma by using the partial wave analysis and effective interaction potential in strong quantum recoil regime. The magnitude of the electron-exchange function is found to increase as the collision energy increases, but it decreases with an increase in the exchange parameter. It is also found that the collisional entanglement fidelity in strong quantum recoil plasmas is enhanced by the quantum-mechanical and shielding effects. The collisional entanglement fidelity in a semiconductor plasma is also enhanced by the collective plasmon oscillation and electron-exchange effect. However, the electron-exchange effect on the fidelity ratio function is reduced as the plasmon energy increases. Moreover, the electron-exchange influence on the fidelity ratio function is found to increase as the Fermi energy in the semiconductor plasma increases.

Competitive interactions and controlled release of a natural antioxidant from halloysite nanotubes.

PubMed

Hári, József; Gyürki, Ádám; Sárközi, Márk; Földes, Enikő; Pukánszky, Béla

2016-01-15

Halloysite nanotubes used as potential carrier material for a controlled release stabilizer in polyethylene were thoroughly characterized with several techniques including the measurement of specific surface area, pore volume and surface energy. The high surface energy of the halloysite results in the strong bonding of the additive to the surface. Dissolution experiments carried out with eight different solvents for the determination of the effect of solvent characteristics on the amount of irreversibly bonded quercetin proved that adsorption and dissolution depend on competitive interactions prevailing in the system. Solvents with low polarity dissolve only surplus quercetin adsorbed in multilayers. Polyethylene is a very apolar polymer forming weak interactions with every substance; quercetin dissolves into it from the halloysite surface only above a critical surface coverage. Stabilization experiments confirmed that strong adhesion prevents dissolution and results in limited stabilization efficiency. At larger adsorbed amounts better stability and extended effect were measured indicating dissolution and controlled release. Copyright © 2015 Elsevier Inc. All rights reserved.

Measures of fidelity of delivery of, and engagement with, complex, face-to-face health behaviour change interventions: A systematic review of measure quality.

PubMed

Walton, Holly; Spector, Aimee; Tombor, Ildiko; Michie, Susan

2017-11-01

Understanding the effectiveness of complex, face-to-face health behaviour change interventions requires high-quality measures to assess fidelity of delivery and engagement. This systematic review aimed to (1) identify the types of measures used to monitor fidelity of delivery of, and engagement with, complex, face-to-face health behaviour change interventions and (2) describe the reporting of psychometric and implementation qualities. Electronic databases were searched, systematic reviews and reference lists were hand-searched, and 21 experts were contacted to identify articles. Studies that quantitatively measured fidelity of delivery of, and/or engagement with, a complex, face-to-face health behaviour change intervention for adults were included. Data on interventions, measures, and psychometric and implementation qualities were extracted and synthesized using narrative analysis. Sixty-six studies were included: 24 measured both fidelity of delivery and engagement, 20 measured fidelity of delivery, and 22 measured engagement. Measures of fidelity of delivery included observation (n = 17; 38.6%), self-report (n = 15; 34%), quantitatively rated qualitative interviews (n = 1; 2.3%), or multiple measures (n = 11; 25%). Measures of engagement included self-report (n = 18; 39.1%), intervention records (n = 11; 24%), or multiple measures (n = 17; 37%). Fifty-one studies (77%) reported at least one psychometric or implementation quality; 49 studies (74.2%) reported at least one psychometric quality, and 17 studies (25.8%) reported at least one implementation quality. Fewer than half of the reviewed studies measured both fidelity of delivery of, and engagement with complex, face-to-face health behaviour change interventions. More studies reported psychometric qualities than implementation qualities. Interpretation of intervention outcomes from fidelity of delivery and engagement measurements may be limited due to a lack of reporting of psychometric and implementation qualities. Statement of contribution What is already known on this subject? Evidence of fidelity and engagement is needed to understand effectiveness of complex interventions Evidence of fidelity and engagement are rarely reported High-quality measures are needed to measure fidelity and engagement What does this study add? Evidence that indicators of quality of measures are reported in some studies Evidence that psychometric qualities are reported more frequently than implementation qualities A recommendation for intervention evaluations to report indicators of quality of fidelity and engagement measures. © 2017 The Authors. British Journal of Health Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Assessment of Fidelity in Interventions to Improve Hand Hygiene of Healthcare Workers: A Systematic Review

PubMed Central

Musuuza, Jackson S.; Barker, Anna; Ngam, Caitlyn; Vellardita, Lia; Safdar, Nasia

2016-01-01

OBJECTIVE Compliance with hand hygiene in healthcare workers is fundamental to infection prevention yet remains a challenge to sustain. We examined fidelity reporting in interventions to improve hand hygiene compliance, and we assessed 5 measures of intervention fidelity: (1) adherence, (2) exposure or dose, (3) quality of intervention delivery, (4) participant responsiveness, and (5) program differentiation. DESIGN Systematic review METHODS A librarian performed searches of the literature in PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), Cochrane Library, and Web of Science of material published prior to June 19, 2015. The review protocol was registered in PROSPERO International Prospective Register of Systematic Reviews, and assessment of study quality was conducted for each study reviewed. RESULTS A total of 100 studies met the inclusion criteria. Only 8 of these 100 studies reported all 5 measures of intervention fidelity. In addition, 39 of 100 (39%) failed to include at least 3 fidelity measures; 20 of 100 (20%) failed to include 4 measures; 17 of 100 (17%) failed to include 2 measures, while 16 of 100 (16%) of the studies failed to include at least 1 measure of fidelity. Participant responsiveness and adherence to the intervention were the most frequently unreported fidelity measures, while quality of the delivery was the most frequently reported measure. CONCLUSIONS Almost all hand hygiene intervention studies failed to report at least 1 fidelity measurement. To facilitate replication and effective implementation, reporting fidelity should be standard practice when describing results of complex behavioral interventions such as hand hygiene. PMID:26861117

A randomized controlled study of manikin simulator fidelity on neonatal resuscitation program learning outcomes.

PubMed

Curran, Vernon; Fleet, Lisa; White, Susan; Bessell, Clare; Deshpandey, Akhil; Drover, Anne; Hayward, Mark; Valcour, James

2015-03-01

The neonatal resuscitation program (NRP) has been developed to educate physicians and other health care providers about newborn resuscitation and has been shown to improve neonatal resuscitation skills. Simulation-based training is recommended as an effective modality for instructing neonatal resuscitation and both low and high-fidelity manikin simulators are used. There is limited research that has compared the effect of low and high-fidelity manikin simulators for NRP learning outcomes, and more specifically on teamwork performance and confidence. The purpose of this study was to examine the effect of using low versus high-fidelity manikin simulators in NRP instruction. A randomized posttest-only control group study design was conducted. Third year undergraduate medical students participated in NRP instruction and were assigned to an experimental group (high-fidelity manikin simulator) or control group (low-fidelity manikin simulator). Integrated skills station (megacode) performance, participant satisfaction, confidence and teamwork behaviour scores were compared between the study groups. Participants in the high-fidelity manikin simulator instructional group reported significantly higher total scores in overall satisfaction (p = 0.001) and confidence (p = 0.001). There were no significant differences in teamwork behaviour scores, as observed by two independent raters, nor differences on mandatory integrated skills station performance items at the p < 0.05 level. Medical students' reported greater satisfaction and confidence with high-fidelity manikin simulators, but did not demonstrate overall significantly improved teamwork or integrated skills station performance. Low and high-fidelity manikin simulators facilitate similar levels of objectively measured NRP outcomes for integrated skills station and teamwork performance.

Mechanisms of deep benzene oxidation on the Pt(1 1 1) surface using temperature-programmed reaction methods

NASA Astrophysics Data System (ADS)

Marsh, Anderson L.; Gland, John L.

2003-06-01

The catalytic oxidation of benzene on the Pt(1 1 1) surface has been characterized using temperature-programmed reaction spectroscopy (TPRS) over a wide range of benzene and oxygen coverages. Coadsorbed atomic oxygen and benzene are the primary reactants on the surface during the initial oxidation step. Benzene is oxidized over the 300-500 K range to produce carbon dioxide and water. Carbon-hydrogen and carbon-carbon bond activation are clearly rate-limiting steps for these reactions. Preferential oxidation causes depletion of bridge-bonded benzene, suggesting enhanced reactivity in this bonding configuration. When oxygen is in excess on the surface, all of the surface carbon and hydrogen is oxidized. When benzene is in excess on the surface, hydrogen produced by dehydrogenation is desorbed after all of the surface oxygen has been consumed. Repulsive interactions between benzene and molecular oxygen dominate at low temperatures. Preadsorption of oxygen inhibits adsorption of less reactive benzene in threefold hollow sites. The desorption temperature of this non-reactive chemisorbed benzene decreases and overlaps with the multilayer desorption peak with increasing oxygen exposure. The results presented here provide a clear picture of rate-limiting steps during deep oxidation of benzene on the Pt(1 1 1) surface.

Whole-Brain In-vivo Measurements of the Axonal G-Ratio in a Group of 37 Healthy Volunteers

PubMed Central

Mohammadi, Siawoosh; Carey, Daniel; Dick, Fred; Diedrichsen, Joern; Sereno, Martin I.; Reisert, Marco; Callaghan, Martina F.; Weiskopf, Nikolaus

2015-01-01

The g-ratio, quantifying the ratio between the inner and outer diameters of a fiber, is an important microstructural characteristic of fiber pathways and is functionally related to conduction velocity. We introduce a novel method for estimating the MR g-ratio non-invasively across the whole brain using high-fidelity magnetization transfer (MT) imaging and single-shell diffusion MRI. These methods enabled us to map the MR g-ratio in vivo across the brain's prominent fiber pathways in a group of 37 healthy volunteers and to estimate the inter-subject variability. Effective correction of susceptibility-related distortion artifacts was essential before combining the MT and diffusion data, in order to reduce partial volume and edge artifacts. The MR g-ratio is in good qualitative agreement with histological findings despite the different resolution and spatial coverage of MRI and histology. The MR g-ratio holds promise as an important non-invasive biomarker due to its microstructural and functional relevance in neurodegeneration. PMID:26640427

Prolongation of SMAP to Spatiotemporally Seamless Coverage of Continental U.S. Using a Deep Learning Neural Network

NASA Astrophysics Data System (ADS)

Fang, Kuai; Shen, Chaopeng; Kifer, Daniel; Yang, Xiao

2017-11-01

The Soil Moisture Active Passive (SMAP) mission has delivered valuable sensing of surface soil moisture since 2015. However, it has a short time span and irregular revisit schedules. Utilizing a state-of-the-art time series deep learning neural network, Long Short-Term Memory (LSTM), we created a system that predicts SMAP level-3 moisture product with atmospheric forcings, model-simulated moisture, and static physiographic attributes as inputs. The system removes most of the bias with model simulations and improves predicted moisture climatology, achieving small test root-mean-square errors (<0.035) and high-correlation coefficients >0.87 for over 75% of Continental United States, including the forested southeast. As the first application of LSTM in hydrology, we show the proposed network avoids overfitting and is robust for both temporal and spatial extrapolation tests. LSTM generalizes well across regions with distinct climates and environmental settings. With high fidelity to SMAP, LSTM shows great potential for hindcasting, data assimilation, and weather forecasting.

Bishop plays down report on condoms / AIDS in France.

PubMed

1996-02-26

Individual bishops in France and other European countries have argued that condom use can save lives by preventing the spread of HIV. The French Bishops' Conference social commission published a 200-page report which in which agreement was expressed with widespread medical opinion that condom use is the sole and necessary barrier against the sexual spread of HIV. Extensive media coverage ensued and led to Bishop Albert Rouet, the bishop of Poitiers and chairman of the French Bishops' Conference, being interviewed by the Holy See's official radio. In the interview, Bishop Rouet distanced the Roman Catholic Church in France from the report, claiming that the media had exaggerated the issue and that his commission was not bound by the reference. The Vatican remains staunchly opposed to condom use against HIV infection and preaches abstinence outside of marriage and fidelity within marriage as the only true ways to avoid HIV infection. In 1995, the Vatican fired Jacques Gaillot, the former bishop of Evreux in Normandy, for his outspoken endorsement of condom use against HIV.

Spatio-Temporal Dynamics of Field Cricket Calling Behaviour: Implications for Female Mate Search and Mate Choice.

PubMed

Nandi, Diptarup; Balakrishnan, Rohini

2016-01-01

Amount of calling activity (calling effort) is a strong determinant of male mating success in species such as orthopterans and anurans that use acoustic communication in the context of mating behaviour. While many studies in crickets have investigated the determinants of calling effort, patterns of variability in male calling effort in natural choruses remain largely unexplored. Within-individual variability in calling activity across multiple nights of calling can influence female mate search and mate choice strategies. Moreover, calling site fidelity across multiple nights of calling can also affect the female mate sampling strategy. We therefore investigated the spatio-temporal dynamics of acoustic signaling behaviour in a wild population of the field cricket species Plebeiogryllus guttiventris. We first studied the consistency of calling activity by quantifying variation in male calling effort across multiple nights of calling using repeatability analysis. Callers were inconsistent in their calling effort across nights and did not optimize nightly calling effort to increase their total number of nights spent calling. We also estimated calling site fidelity of males across multiple nights by quantifying movement of callers. Callers frequently changed their calling sites across calling nights with substantial displacement but without any significant directionality. Finally, we investigated trade-offs between within-night calling effort and energetically expensive calling song features such as call intensity and chirp rate. Calling effort was not correlated with any of the calling song features, suggesting that energetically expensive song features do not constrain male calling effort. The two key features of signaling behaviour, calling effort and call intensity, which determine the duration and spatial coverage of the sexual signal, are therefore uncorrelated and function independently.

Multi-fidelity methods for uncertainty quantification in transport problems

NASA Astrophysics Data System (ADS)

Tartakovsky, G.; Yang, X.; Tartakovsky, A. M.; Barajas-Solano, D. A.; Scheibe, T. D.; Dai, H.; Chen, X.

2016-12-01

We compare several multi-fidelity approaches for uncertainty quantification in flow and transport simulations that have a lower computational cost than the standard Monte Carlo method. The cost reduction is achieved by combining a small number of high-resolution (high-fidelity) simulations with a large number of low-resolution (low-fidelity) simulations. We propose a new method, a re-scaled Multi Level Monte Carlo (rMLMC) method. The rMLMC is based on the idea that the statistics of quantities of interest depends on scale/resolution. We compare rMLMC with existing multi-fidelity methods such as Multi Level Monte Carlo (MLMC) and reduced basis methods and discuss advantages of each approach.

Fidelity for kicked atoms with gravity near a quantum resonance.

PubMed

Dubertrand, Rémy; Guarneri, Italo; Wimberger, Sandro

2012-03-01

Kicked atoms under a constant Stark or gravity field are investigated for experimental setups with cold and ultracold atoms. The parametric stability of the quantum dynamics is studied using the fidelity. In the case of a quantum resonance, it is shown that the behavior of the fidelity depends on arithmetic properties of the gravity parameter. Close to a quantum resonance, the long-time asymptotics of the fidelity is studied by means of a pseudoclassical approximation introduced by Fishman et al. [J. Stat. Phys. 110, 911 (2003)]. The long-time decay of fidelity arises from the tunneling out of pseudoclassical stable islands, and a simple ansatz is proposed which satisfactorily reproduces the main features observed in numerical simulations.

Assessing fidelity of delivery of smoking cessation behavioural support in practice.

PubMed

Lorencatto, Fabiana; West, Robert; Christopherson, Charlotte; Michie, Susan

2013-04-04

Effectiveness of evidence-based behaviour change interventions is likely to be undermined by failure to deliver interventions as planned. Behavioural support for smoking cessation can be a highly cost-effective, life-saving intervention. However, in practice, outcomes are highly variable. Part of this may be due to variability in fidelity of intervention implementation. To date, there have been no published studies on this. The present study aimed to: evaluate a method for assessing fidelity of behavioural support; assess fidelity of delivery in two English Stop-Smoking Services; and compare the extent of fidelity according to session types, duration, individual practitioners, and component behaviour change techniques (BCTs). Treatment manuals and transcripts of 34 audio-recorded behavioural support sessions were obtained from two Stop-Smoking Services and coded into component BCTs using a taxonomy of 43 BCTs. Inter-rater reliability was assessed using percentage agreement. Fidelity was assessed by examining the proportion of BCTs specified in the manuals that were delivered in individual sessions. This was assessed by session type (i.e., pre-quit, quit, post-quit), duration, individual practitioner, and BCT. Inter-coder reliability was high (87.1%). On average, 66% of manual-specified BCTs were delivered per session (SD 15.3, range: 35% to 90%). In Service 1, average fidelity was highest for post-quit sessions (69%) and lowest for pre-quit (58%). In Service 2, fidelity was highest for quit-day (81%) and lowest for post-quit sessions (56%). Session duration was not significantly correlated with fidelity. Individual practitioner fidelity ranged from 55% to 78%. Individual manual-specified BCTs were delivered on average 63% of the time (SD 28.5, range: 0 to 100%). The extent to which smoking cessation behavioural support is delivered as specified in treatment manuals can be reliably assessed using transcripts of audiotaped sessions. This allows the investigation of the implementation of evidence-based practice in relation to smoking cessation, a first step in designing interventions to improve it. There are grounds for believing that fidelity in the English Stop-Smoking Services may be low and that routine monitoring is warranted.

Development of a measure of model fidelity for mental health Crisis Resolution Teams.

PubMed

Lloyd-Evans, Brynmor; Bond, Gary R; Ruud, Torleif; Ivanecka, Ada; Gray, Richard; Osborn, David; Nolan, Fiona; Henderson, Claire; Mason, Oliver; Goater, Nicky; Kelly, Kathleen; Ambler, Gareth; Morant, Nicola; Onyett, Steve; Lamb, Danielle; Fahmy, Sarah; Brown, Ellie; Paterson, Beth; Sweeney, Angela; Hindle, David; Fullarton, Kate; Frerichs, Johanna; Johnson, Sonia

2016-12-01

Crisis Resolution Teams (CRTs) provide short-term intensive home treatment to people experiencing mental health crisis. Trial evidence suggests CRTs can be effective at reducing hospital admissions and increasing satisfaction with acute care. When scaled up to national level however, CRT implementation and outcomes have been variable. We aimed to develop and test a fidelity scale to assess adherence to a model of best practice for CRTs, based on best available evidence. A concept mapping process was used to develop a CRT fidelity scale. Participants (n = 68) from a range of stakeholder groups prioritised and grouped statements (n = 72) about important components of the CRT model, generated from a literature review, national survey and qualitative interviews. These data were analysed using Ariadne software and the resultant cluster solution informed item selection for a CRT fidelity scale. Operational criteria and scoring anchor points were developed for each item. The CORE CRT fidelity scale was then piloted in 75 CRTs in the UK to assess the range of scores achieved and feasibility for use in a 1-day fidelity review process. Trained reviewers (n = 16) rated CRT service fidelity in a vignette exercise to test the scale's inter-rater reliability. There were high levels of agreement within and between stakeholder groups regarding the most important components of the CRT model. A 39-item measure of CRT model fidelity was developed. Piloting indicated that the scale was feasible for use to assess CRT model fidelity and had good face validity. The wide range of item scores and total scores across CRT services in the pilot demonstrate the measure can distinguish lower and higher fidelity services. Moderately good inter-rater reliability was found, with an estimated correlation between individual ratings of 0.65 (95% CI: 0.54 to 0.76). The CORE CRT Fidelity Scale has been developed through a rigorous and systematic process. Promising initial testing indicates its value in assessing adherence to a model of CRT best practice and to support service improvement monitoring and planning. Further research is required to establish its psychometric properties and international applicability.

Fidelity Mechanisms of DNA Polymerase Alpha

DTIC Science & Technology

2008-07-23

significantly lowers fidelity. Analogously, adding the equivalent of N-3 to low-fidelity benzimidazole -derived bases (generating 1-deazapurines... benzimidazole or to 1-deazapurines significantly decreases the rate at which pol α polymerizes the resulting bases opposite A, C, and G, while simultaneously

Site-Specific Imaging of Elemental Steps in Dehydration of Diols on TiO 2(110)

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

Acharya, Danda P.; Yoon, Yeohoon; Li, Zhenjun

2013-11-26

The conversion of diols on partially reduced TiO 2(110) at low coverage was studied using variable-temperature scanning tunneling microscopy, temperature programmed desorption and density functional theory calculations. We find, that below ~230 K, ethane-1,2-diol and propane-1,3-diol molecules adsorb predominantly on five-fold coordinated Ti5c atoms. The dynamic equilibrium between molecularly bound and dissociated species resulting from O-H bond scission and reformation is observed. As the diols start to diffuse on the Ti5c rows above ~230 K, they dissociate irreversibly upon encountering bridging oxygen (O b) vacancy (VO’s) defects. Two dissociation pathways, one via O-H and the other via C-O bond scissionmore » leading to identical surface intermediates, hydroxyalkoxy, O b-(CH 2)n-OH (n = 2, 3) and bridging hydroxyl, HO b, are seen. For O-H bond scission, the O b-(CH 2)n-OH is found on the position of the original VO, while for C-O scission it is found on the adjacent Ob site. Theoretical calculations suggest that the observed mixture of C-O/O-H bond breaking processes are a result of the steric factors enforced upon the diols by the second OH group that is bound to a Ti5c site. At room temperature, rich dissociation/reformation dynamics of the second, Ti5c-bound O-H leads to the formation of dioxo, Ob-(CH 2)n-OTi, species. Above ~400 K, both O b-(CH 2)n-OH and Ob-(CH 2)n-OTi species convert into a new intermediate, that is centered on Ob row. Combined experimental and theoretical evidence shows that this intermediate is most likely a new dioxo, O b-(CH 2) 2-Ob, species. Further annealing leads to sequential C-Ob bond cleavage and alkene desorption above ~ 500 K. Simulations find that the sequential C-O bond breaking process follows a homolytic diradical pathway with the first C-O bond breaking event accompanied by a non-adiabatic electron transfer within the TiO 2(110) substrate.« less

The effect of nano-structured alumina coating on resin-bond strength to zirconia ceramics.

PubMed

Jevnikar, Peter; Krnel, Kristoffer; Kocjan, Andraz; Funduk, Nenad; Kosmac, Tomaz

2010-07-01

The aim of this study was to functionalize the surface of yttria partially stabilized tetragonal zirconia ceramics (Y-TZP) with a nano-structured alumina coating to improve resin bonding. A total of 120 densely sintered disc-shaped specimens (15.5+/-0.03 mm in diameter and 2.6+/-0.03 mm thick) were produced from biomedical-grade TZ-3YB-E zirconia powder (Tosoh, Tokyo, Japan), randomly divided into three groups of 40 and subjected to the following surface treatments: AS - as-sintered; APA - airborne-particle abraded; POL - polished. Half of the discs in each group received an alumina coating that was fabricated by exploiting the hydrolysis of aluminium nitride (AlN) powder (groups AS-C, APA-C, POL-C). The coating was characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The shear-bond strength of the self-etching composite resin (RelyX Unicem, 3M ESPE, USA) was then studied for the coated and uncoated surfaces of the as-sintered, polished and airborne-particle abraded specimens before and after thermocycling (TC). The SEM/TEM analyses revealed that the application of an alumina coating to Y-TZP ceramics created a highly retentive surface for resin penetration. The coating showed good surface coverage and a uniform thickness of 240 nm. The resin-bond strength to the groups AS-C, APA-C, POL-C was significantly higher than to the groups AS, APA and POL, both before and after TC (p< or =0.05). During TC all the specimens in the POL and AS groups debonded spontaneously. In contrast, the TC did not affect the bond strength of the AS-C, POL-C and APA-C groups. A non-invasive method has been developed that significantly improves resin-bond strength to Y-TZP ceramics. After surface functionalization the bond survives thermocycling without reduction in strength. The method is relatively simple and has the potential to become an effective conditioning method for zirconia ceramics. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Within-subjects comparison of the HiRes and Fidelity120 speech processing strategies: Speech perception and its relation to place-pitch sensitivity

PubMed Central

Donaldson, Gail S.; Dawson, Patricia K.; Borden, Lamar Z.

2010-01-01

Objectives Previous studies have confirmed that current steering can increase the number of discriminable pitches available to many CI users; however, the ability to perceive additional pitches has not been linked to improved speech perception. The primary goals of this study were to determine (1) whether adult CI users can achieve higher levels of spectral-cue transmission with a speech processing strategy that implements current steering (Fidelity120) than with a predecessor strategy (HiRes) and, if so, (2) whether the magnitude of improvement can be predicted from individual differences in place-pitch sensitivity. A secondary goal was to determine whether Fidelity120 supports higher levels of speech recognition in noise than HiRes. Design A within-subjects repeated measures design evaluated speech perception performance with Fidelity120 relative to HiRes in 10 adult CI users. Subjects used the novel strategy (either HiRes or Fidelity120) for 8 weeks during the main study; a subset of five subjects used Fidelity120 for 3 additional months following the main study. Speech perception was assessed for the spectral cues related to vowel F1 frequency (Vow F1), vowel F2 frequency (Vow F2) and consonant place of articulation (Con PLC); overall transmitted information for vowels (Vow STIM) and consonants (Con STIM); and sentence recognition in noise. Place-pitch sensitivity was measured for electrode pairs in the apical, middle and basal regions of the implanted array using a psychophysical pitch-ranking task. Results With one exception, there was no effect of strategy (HiRes vs. Fidelity120) on the speech measures tested, either during the main study (n=10) or after extended use of Fidelity120 (n=5). The exception was a small but significant advantage for HiRes over Fidelity120 for the Con STIM measure during the main study. Examination of individual subjects' data revealed that 3 of 10 subjects demonstrated improved perception of one or more spectral cues with Fidelity120 relative to HiRes after 8 weeks or longer experience with Fidelity120. Another 3 subjects exhibited initial decrements in spectral cue perception with Fidelity120 at the 8 week time point; however, evidence from one subject suggested that such decrements may resolve with additional experience. Place-pitch thresholds were inversely related to improvements in Vow F2 perception with Fidelity120 relative to HiRes. However, no relationship was observed between place-pitch thresholds and the other spectral measures (Vow F1 or Con PLC). Conclusions Findings suggest that Fidelity120 supports small improvements in the perception of spectral speech cues in some Advanced Bionics CI users; however, many users show no clear benefit. Benefits are more likely to occur for vowel spectral cues (related to F1 and F2 frequency) than for consonant spectral cues (related to place of articulation). There was an inconsistent relationship between place-pitch sensitivity and improvements in spectral cue perception with Fidelity120 relative to HiRes. This may partly reflect the small number of sites at which place-pitch thresholds were measured. Contrary to some previous reports, there was no clear evidence that Fidelity120 supports improved sentence recognition in noise. PMID:21084987

Human female orgasm as evolved signal: a test of two hypotheses.

PubMed

Ellsworth, Ryan M; Bailey, Drew H

2013-11-01

We present the results of a study designed to empirically test predictions derived from two hypotheses regarding human female orgasm behavior as an evolved communicative trait or signal. One hypothesis tested was the female fidelity hypothesis, which posits that human female orgasm signals a woman's sexual satisfaction and therefore her likelihood of future fidelity to a partner. The other was sire choice hypothesis, which posits that women's orgasm behavior signals increased chances of fertilization. To test the two hypotheses of human female orgasm, we administered a questionnaire to 138 females and 121 males who reported that they were currently in a romantic relationship. Key predictions of the female fidelity hypothesis were not supported. In particular, orgasm was not associated with female sexual fidelity nor was orgasm associated with male perceptions of partner sexual fidelity. However, faked orgasm was associated with female sexual infidelity and lower male relationship satisfaction. Overall, results were in greater support of the sire choice signaling hypothesis than the female fidelity hypothesis. Results also suggest that male satisfaction with, investment in, and sexual fidelity to a mate are benefits that favored the selection of orgasmic signaling in ancestral females.

Fidelity assessment of a UH-60A simulation on the NASA Ames vertical motion simulator

NASA Technical Reports Server (NTRS)

Atencio, Adolph, Jr.

1993-01-01

Helicopter handling qualities research requires that a ground-based simulation be a high-fidelity representation of the actual helicopter, especially over the frequency range of the investigation. This experiment was performed to assess the current capability to simulate the UH-60A Black Hawk helicopter on the Vertical Motion Simulator (VMS) at NASA Ames, to develop a methodology for assessing the fidelity of a simulation, and to find the causes for lack of fidelity. The approach used was to compare the simulation to the flight vehicle for a series of tasks performed in flight and in the simulator. The results show that subjective handling qualities ratings from flight to simulator overlap, and the mathematical model matches the UH-60A helicopter very well over the range of frequencies critical to handling qualities evaluation. Pilot comments, however, indicate a need for improvement in the perceptual fidelity of the simulation in the areas of motion and visual cuing. The methodology used to make the fidelity assessment proved useful in showing differences in pilot work load and strategy, but additional work is needed to refine objective methods for determining causes of lack of fidelity.

The tug-of-war: fidelity versus adaptation throughout the health promotion program life cycle.

PubMed

Bopp, Melissa; Saunders, Ruth P; Lattimore, Diana

2013-06-01

Researchers across multiple fields have described the iterative and nonlinear phases of the translational research process from program development to dissemination. This process can be conceptualized within a "program life cycle" framework that includes overlapping and nonlinear phases: development, adoption, implementation, maintenance, sustainability or termination, and dissemination or diffusion, characterized by tensions between fidelity to the original plan and adaptation for the setting and population. In this article, we describe the life cycle (phases) for research-based health promotion programs, the key influences at each phase, and the issues related to the tug-of-war between fidelity and adaptation throughout the process using a fictionalized case study based on our previous research. This article suggests the importance of reconceptualizing intervention design, involving stakeholders, and monitoring fidelity and adaptation throughout all phases to maintain implementation fidelity and completeness. Intervention fidelity should be based on causal mechanisms to ensure effectiveness, while allowing for appropriate adaption to ensure maximum implementation and sustainability. Recommendations for future interventions include considering the determinants of implementation including contextual factors at each phase, the roles of stakeholders, and the importance of developing a rigorous, adaptive, and flexible definition of implementation fidelity and completeness.

Unbiased multi-fidelity estimate of failure probability of a free plane jet

NASA Astrophysics Data System (ADS)

Marques, Alexandre; Kramer, Boris; Willcox, Karen; Peherstorfer, Benjamin

2017-11-01

Estimating failure probability related to fluid flows is a challenge because it requires a large number of evaluations of expensive models. We address this challenge by leveraging multiple low fidelity models of the flow dynamics to create an optimal unbiased estimator. In particular, we investigate the effects of uncertain inlet conditions in the width of a free plane jet. We classify a condition as failure when the corresponding jet width is below a small threshold, such that failure is a rare event (failure probability is smaller than 0.001). We estimate failure probability by combining the frameworks of multi-fidelity importance sampling and optimal fusion of estimators. Multi-fidelity importance sampling uses a low fidelity model to explore the parameter space and create a biasing distribution. An unbiased estimate is then computed with a relatively small number of evaluations of the high fidelity model. In the presence of multiple low fidelity models, this framework offers multiple competing estimators. Optimal fusion combines all competing estimators into a single estimator with minimal variance. We show that this combined framework can significantly reduce the cost of estimating failure probabilities, and thus can have a large impact in fluid flow applications. This work was funded by DARPA.

78 FR 23793 - Fidelity Merrimack Street Trust, et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

...''), Fidelity Management & Research Company (the ``Adviser'') and Fidelity Distributors Corporation (the ``Distributor''). Summary of Application: Applicants request an order that permits: (a) Actively-managed series... market prices; (c) certain series to pay redemption proceeds, under certain circumstances, more than...

Fidelity between Gaussian mixed states with quantum state quadrature variances

NASA Astrophysics Data System (ADS)

Hai-Long, Zhang; Chun, Zhou; Jian-Hong, Shi; Wan-Su, Bao

2016-04-01

In this paper, from the original definition of fidelity in a pure state, we first give a well-defined expansion fidelity between two Gaussian mixed states. It is related to the variances of output and input states in quantum information processing. It is convenient to quantify the quantum teleportation (quantum clone) experiment since the variances of the input (output) state are measurable. Furthermore, we also give a conclusion that the fidelity of a pure input state is smaller than the fidelity of a mixed input state in the same quantum information processing. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002) and the Foundation of Science and Technology on Information Assurance Laboratory (Grant No. KJ-14-001).

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

Jung, Young-Dae

The plasmon and screening effects on the entanglement fidelity for the elastic electron-ion collision are investigated in hot quantum plasmas. The partial wave analysis and effective interaction including the plasmon couplings are employed to obtain the entanglement fidelity function in hot quantum plasmas. It is shown that the plasmon effect enhances the entanglement fidelity in quantum plasmas for 0<{beta}({identical_to}({Dirac_h}/2{pi}){omega}{sub p}/k{sub B}T)<0.8 and, however, suppresses the entanglement fidelity for 0.8<{beta}<1, where {omega}{sub p} is the plasmon frequency, k{sub B} is the Boltzmann constant, and T is the plasma temperature. It is also found that the entanglement fidelity decreases with increasing Debyemore » length and collision energy.« less

A conceptual framework for implementation fidelity

PubMed Central

Carroll, Christopher; Patterson, Malcolm; Wood, Stephen; Booth, Andrew; Rick, Jo; Balain, Shashi

2007-01-01

Background Implementation fidelity refers to the degree to which an intervention or programme is delivered as intended. Only by understanding and measuring whether an intervention has been implemented with fidelity can researchers and practitioners gain a better understanding of how and why an intervention works, and the extent to which outcomes can be improved. Discussion The authors undertook a critical review of existing conceptualisations of implementation fidelity and developed a new conceptual framework for understanding and measuring the process. The resulting theoretical framework requires testing by empirical research. Summary Implementation fidelity is an important source of variation affecting the credibility and utility of research. The conceptual framework presented here offers a means for measuring this variable and understanding its place in the process of intervention implementation. PMID:18053122

Fidelity decay in interacting two-level boson systems: Freezing and revivals

NASA Astrophysics Data System (ADS)

Benet, Luis; Hernández-Quiroz, Saúl; Seligman, Thomas H.

2011-05-01

We study the fidelity decay in the k-body embedded ensembles of random matrices for bosons distributed in two single-particle states, considering the reference or unperturbed Hamiltonian as the one-body terms and the diagonal part of the k-body embedded ensemble of random matrices and the perturbation as the residual off-diagonal part of the interaction. We calculate the ensemble-averaged fidelity with respect to an initial random state within linear response theory to second order on the perturbation strength and demonstrate that it displays the freeze of the fidelity. During the freeze, the average fidelity exhibits periodic revivals at integer values of the Heisenberg time tH. By selecting specific k-body terms of the residual interaction, we find that the periodicity of the revivals during the freeze of fidelity is an integer fraction of tH, thus relating the period of the revivals with the range of the interaction k of the perturbing terms. Numerical calculations confirm the analytical results.

Preschool children's development in classic Montessori, supplemented Montessori, and conventional programs.

PubMed

Lillard, Angeline S

2012-06-01

Research on the outcomes of Montessori education is scarce and results are inconsistent. One possible reason for the inconsistency is variations in Montessori implementation fidelity. To test whether outcomes vary according to implementation fidelity, we examined preschool children enrolled in high fidelity classic Montessori programs, lower fidelity Montessori programs that supplemented the program with conventional school activities, and, for comparison, conventional programs. Children were tested at the start and end of the school year on a range of social and academic skills. Although they performed no better in the fall, children in Classic Montessori programs, as compared with children in Supplemented Montessori and Conventional programs, showed significantly greater school-year gains on outcome measures of executive function, reading, math, vocabulary, and social problem-solving, suggesting that high fidelity Montessori implementation is associated with better outcomes than lower fidelity Montessori programs or conventional programs. Copyright © 2012 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Early Influences and Later Outcomes Associated With Developmental Trajectories of Eriksonian Fidelity

PubMed Central

Brittian, Aerika S.; Lerner, Richard M.

2014-01-01

Although Eriksonian theory suggests that adolescents’ sense of fidelity is a key component of healthy development, research on this psychosocial construct has been limited. The current study developed an index of youth fidelity, examined the developmental course of this construct, explored the influence of contextual factors on different fidelity trajectories, and tested if trajectories were associated with later indicators of adolescents’ positive development. Participants included 1,941 ethnically diverse youth (61% female) participants in the 4-H Study of Positive Youth Development who were recruited from schools and youth development programs across the United States. Results suggested that three types of developmental trajectories existed among youth: high and increasing, moderate and increasing, and low and decreasing. Fidelity group membership varied in relation to social relationships and psychosocial and behavioral characteristics (i.e., contribution, substance use, and delinquency). Girls were more likely than boys to be in the highest fidelity trajectories. Directions for future research and implications for enhancing the thriving of adolescents are discussed. PMID:22545838

Construction of nested maximin designs based on successive local enumeration and modified novel global harmony search algorithm

NASA Astrophysics Data System (ADS)

Yi, Jin; Li, Xinyu; Xiao, Mi; Xu, Junnan; Zhang, Lin

2017-01-01

Engineering design often involves different types of simulation, which results in expensive computational costs. Variable fidelity approximation-based design optimization approaches can realize effective simulation and efficiency optimization of the design space using approximation models with different levels of fidelity and have been widely used in different fields. As the foundations of variable fidelity approximation models, the selection of sample points of variable-fidelity approximation, called nested designs, is essential. In this article a novel nested maximin Latin hypercube design is constructed based on successive local enumeration and a modified novel global harmony search algorithm. In the proposed nested designs, successive local enumeration is employed to select sample points for a low-fidelity model, whereas the modified novel global harmony search algorithm is employed to select sample points for a high-fidelity model. A comparative study with multiple criteria and an engineering application are employed to verify the efficiency of the proposed nested designs approach.

An Investigation of the Impact of Aerodynamic Model Fidelity on Close-In Combat Effectiveness Prediction in Piloted Simulation

NASA Technical Reports Server (NTRS)

Persing, T. Ray; Bellish, Christine A.; Brandon, Jay; Kenney, P. Sean; Carzoo, Susan; Buttrill, Catherine; Guenther, Arlene

2005-01-01

Several aircraft airframe modeling approaches are currently being used in the DoD community for acquisition, threat evaluation, training, and other purposes. To date there has been no clear empirical study of the impact of airframe simulation fidelity on piloted real-time aircraft simulation study results, or when use of a particular level of fidelity is indicated. This paper documents a series of piloted simulation studies using three different levels of airframe model fidelity. This study was conducted using the NASA Langley Differential Maneuvering Simulator. Evaluations were conducted with three pilots for scenarios requiring extensive maneuvering of the airplanes during air combat. In many cases, a low-fidelity modified point-mass model may be sufficient to evaluate the combat effectiveness of the aircraft. However, in cases where high angle-of-attack flying qualities and aerodynamic performance are a factor or when precision tracking ability of the aircraft must be represented, use of high-fidelity models is indicated.

A preliminary analysis of the effects of coaching feedback on teacher implementation fidelity of first step to success.

PubMed

Rodriguez, Billie Jo; Loman, Sheldon L; Horner, Robert H

2009-01-01

First Step to Success (FSS) is a "manualized" intervention with documented effectiveness in reducing problem behaviors for young children at risk for school failure. This study is a preliminary analysis focusing on the role of performance feedback from FSS coaches on the fidelity with which teachers implemented FSS. Three typically developing students (2 kindergarten and 1 first grade) and their respective teachers served as participants. Student behavior and teacher implementation fidelity were assessed using a nonconcurrent multiple baseline design across student/teacher dyads, in which a no coaching baseline was followed by a performance feedback condition. The baseline phase showed modest levels of implementation fidelity and initial low levels of problem behavior followed by gradually increasing trends. A relation was demonstrated between coaching feedback and improved implementation fidelity. In addition, improved fidelity was associated with improvements in student problem behavior. Implications are drawn for clinical application of FSS and other "manualized" interventions.

Adsorption of small hydrocarbons on rutile TiO2(110)

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

Chen, Long; Smith, R. Scott; Kay, Bruce D.

2016-08-01

Temperature programmed desorption and molecular beam scattering were used to study the adsorption and desorption of small hydrocarbons (n-alkanes, 1-alkenes and 1-alkynes with 1 - 4 carbon atoms of C1-C4) on rutile TiO2(110). We show that the sticking coefficients for all the hydrocarbons are close to unity (> 0.95) at an adsorption temperature of 60 K. The desorption energies for hydrocarbons of the same chain length increase from n-alkanes to 1-alkenes and to 1-alkynes. This trend is likely a consequence of an additional dative bonding of the alkene and alkyne π system to the coordinatively unsaturated Ti5c sites. Similar tomore » previous studies on the adsorption of n-alkanes on metal and metal oxide surfaces, we find the desorption energies within each group (n-alkanes vs. 1-alkenes vs. 1-alkynes) from Ti5c sites increase linearly with the chain length. The absolute saturation coverages of each hydrocarbon on Ti5c sites were also determined. The saturation coverage of CH4, is found to be ~ 2/3 monolayer (ML). The saturation coverages of C2-C4 hydrocarbons are found nearly independent of the chain length with values of ~1/2 ML for n-alkanes and 1-alkenes and 2/3 ML for 1-alkynes. This result is surprising considering their similar sizes.« less

Adsorption of small hydrocarbons on rutile TiO 2(110)

DOE PAGES

Chen, Long; Smith, R. Scott; Kay, Bruce D.; ...

2015-11-21

Here, temperature programmed desorption and molecular beam scattering were used to study the adsorption and desorption of small hydrocarbons (n-alkanes, 1-alkenes and 1-alkynes of C 1–C 4) on rutile TiO 2(110). We show that the sticking coefficients for all the hydrocarbons are close to unity (> 0.95) at an adsorption temperature of 60 K. The desorption energies for hydrocarbons of the same chain length increase from n-alkanes to 1-alkenes and to 1-alkynes. This trend is likely a consequence of additional dative bonding of the alkene and alkyne π system to the coordinatively unsaturated Ti 5c sites. Similar to previous studiesmore » on the adsorption of n-alkanes on metal and metal oxide surfaces, we find that the desorption energies within each group (n-alkanes vs. 1-alkenes vs. 1-alkynes) from Ti 5c sites increase linearly with the chain length. The absolute saturation coverages of each hydrocarbon on Ti 5c sites were also determined. The saturation coverage of CH 4, is found to be ~ 2/3 monolayer (ML). The saturation coverages of C 2–C 4 hydrocarbons are found nearly independent of the chain length with values of ~ 1/2 ML for n-alkanes and 1-alkenes and 2/3 ML for 1-alkynes. This result is surprising considering their similar sizes.« less

Sobriety Treatment and Recovery Teams: Implementation Fidelity and Related Outcomes.

PubMed

Huebner, Ruth A; Posze, Lynn; Willauer, Tina M; Hall, Martin T

2015-01-01

Although integrated programs between child welfare and substance abuse treatment are recommended for families with co-occurring child maltreatment and substance use disorders, implementing integrated service delivery strategies with fidelity is a challenging process. This study of the first five years of the Sobriety Treatment and Recovery Team (START) program examines implementation fidelity using a model proposed by Carroll et al. (2007). The study describes the process of strengthening moderators of implementation fidelity, trends in adherence to START service delivery standards, and trends in parent and child outcomes. Qualitative and quantitative measures were used to prospectively study three START sites serving 341 families with 550 parents and 717 children. To achieve implementation fidelity to service delivery standards required a pre-service year and two full years of operation, persistent leadership, and facilitative actions that challenged the existing paradigm. Over four years of service delivery, the time from the child protective services report to completion of five drug treatment sessions was reduced by an average of 75 days. This trend was associated with an increase in parent retention, parental sobriety, and parent retention of child custody. Conclusions/Importance: Understanding the implementation processes necessary to establish complex integrated programs may support realistic allocation of resources. Although implementation fidelity is a moderator of program outcome, complex inter-agency interventions may benefit from innovative measures of fidelity that promote improvement without extensive cost and data collection burden. The implementation framework applied in this study was useful in examining implementation processes, fidelity, and related outcomes.

Intervention fidelity in primary care complex intervention trials: qualitative study using telephone interviews of patients and practitioners.

PubMed

Dyas, Jane V; Togher, Fiona; Siriwardena, A Niroshan

2014-01-01

Treatment fidelity has previously been defined as the degree to which a treatment or intervention is delivered to participants as intended. Underreporting of fidelity in primary care randomised controlled trials (RCTs) of complex interventions reduces our confidence that findings are due to the treatment or intervention being investigated, rather than unknown confounders. We aimed to investigate treatment fidelity (for the purpose of this paper, hereafter referred to as intervention fidelity), of an educational intervention delivered to general practice teams and designed to improve the primary care management of insomnia. We conducted telephone interviews with patients and practitioners participating in the intervention arm of the trial to explore trial fidelity. Qualitative analysis was undertaken using constant comparison and a priori themes (categories): 'adherence to the delivery of the intervention', 'patients received and understood intervention' and 'patient enactment'. If the intervention protocol was not adhered to by the practitioner then patient receipt, understanding and enactment levels were reduced. Recruitment difficulties in terms of the gap between initially being recruited into the study and attending an intervention consultation also reduced the effectiveness of the intervention. Patient attributes such as motivation to learn and engage contributed to the success of the uptake of the intervention. Qualitative methods using brief telephone interviews are an effective way of collecting the depth of data required to assess intervention fidelity. Intervention fidelity monitoring should be an important element of definitive trial design. ClinicalTrials. gov id isrctn 55001433 - www.controlled-trials.com/isrctn55001433.

Actionable Steps for Engaging Assessment Practitioners and Faculty in Implementation Fidelity Research

ERIC Educational Resources Information Center

Smith, Kristen L.; Finney, Sara J.; Fulcher, Keston H.

2017-01-01

Implementation fidelity data indicate to what extent the delivered educational intervention (e.g., pedagogies, curricula) differs from the designed intervention (Gerstner & Finney, 2013; O'Donnell, 2008). Fidelity data help practitioners make more accurate inferences regarding program effectiveness (Dumas, Lynch, Laughlin, Smith, & Prinz,…

Evaluating the underlying factors behind variable rate debt.

PubMed

McCue, Michael J; Kim, Tae Hyun Tanny

2007-01-01

Recent trends show a greater usage of variable rate debt among health care bond issues. In 2004, 63.4% of the total health care bonds issued were variable rate compared with 30.6% in 1995 (Fitch Ratings, 2005). The purpose of this study is to gain a better understanding of the underlying factors, credit spread, issue characteristics, and issuer factors behind why hospitals and health system borrowers select variable rate debt compared with fixed rate debt. From 2000 to 2004, this study sampled 230 newly issued tax-exempt bonds issued by acute care hospitals and health care systems that included both variable and fixed rate debt issues. Using a logistic regression model, hospitals with variable rate debt issues were assigned a value of 1, whereas hospitals with fixed rate debt issues were assigned a value of 0. This study found a positive association between bond insurance and variable rate debt and a negative association between callable feature and variable rate debt. Facilities located in certificate-of-need states that possessed higher case mix acuity, earned higher profit margins, generated higher debt service coverage, and held less debt were more likely to issue variable rate debt. Overall, hospital managers and board members of hospitals possessing a strong financial performance have an interest in utilizing variable rate debt to lower their cost of capital. In addition, this outcome may also reflect that investment bankers are doing a better job in educating senior hospital management about the interest rate savings benefit of variable rate compared with fixed rate debt.

Fidelity in After-School Program Intervention Research: A Systematic Review

ERIC Educational Resources Information Center

Maynard, Brandy R.; Peters, Kristen E.; Vaughn, Michael G.; Sarteschi, Christine M.

2014-01-01

Over the past 2 decades, the number of after-school programs (ASP) and the number of students attending ASPs has markedly increased. Although several reviews and meta-analyses have examined the outcomes of ASPs, ASP intervention study reviews have not specifically examined intervention fidelity. Establishing intervention fidelity is critically…

Specification of Training Simulator Fidelity: A Research Plan. Technical Report 558.

ERIC Educational Resources Information Center

Baum, David R.; And Others

This report presents a research plan to guide the determination of the empirical relationship between level of maintenance training simulator fidelity and training effectiveness. Chapter I describes data collection and analysis activities undertaken to provide guidance for fidelity decision making by the training simulator development community.…

Commentary: Learning from Variations in Fidelity of Implementation

ERIC Educational Resources Information Center

Balu, Rekha; Doolittle, Fred

2016-01-01

The articles in this special issue discuss efforts to improve academic reading outcomes for students and ways to achieve high implementation fidelity of promising strategies. At times the authors discuss if--and how--strong fidelity is associated with strong outcomes and potentially even impacts (the difference between program and control group…

Investigating Predictors of Fidelity of Implementation for a Preschool Vocabulary and Language Curriculum

ERIC Educational Resources Information Center

Phillips, Beth M.; Ingrole, Smriti A.; Burris, Pamela W.; Tabulda, Galiya

2017-01-01

This study describes initial development, feasibility, and fidelity of implementation of a vocabulary and language curriculum supplement that combined explicit instruction and educational television programming to enhance children's vocabulary acquisition. Efficacy of an intervention relies in part on its fidelity of implementation, but little is…

Preschool Children's Development in Classic Montessori, Supplemented Montessori, and Conventional Programs

ERIC Educational Resources Information Center

Lillard, Angeline S.

2012-01-01

Research on the outcomes of Montessori education is scarce and results are inconsistent. One possible reason for the inconsistency is variations in Montessori implementation fidelity. To test whether outcomes vary according to implementation fidelity, we examined preschool children enrolled in high fidelity classic Montessori programs, lower…

Flight simulator fidelity assessment in a rotorcraft lateral translation maneuver

NASA Technical Reports Server (NTRS)

Hess, R. A.; Malsbury, T.; Atencio, A., Jr.

1992-01-01

A model-based methodology for assessing flight simulator fidelity in closed-loop fashion is exercised in analyzing a rotorcraft low-altitude maneuver for which flight test and simulation results were available. The addition of a handling qualities sensitivity function to a previously developed model-based assessment criteria allows an analytical comparison of both performance and handling qualities between simulation and flight test. Model predictions regarding the existence of simulator fidelity problems are corroborated by experiment. The modeling approach is used to assess analytically the effects of modifying simulator characteristics on simulator fidelity.

Recommendations on Model Fidelity for Wind Turbine Gearbox Simulations; NREL (National Renewable Energy Laboratory)

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

Keller, J.; Lacava, W.; Austin, J.

2015-02-01

This work investigates the minimum level of fidelity required to accurately simulate wind turbine gearboxes using state-of-the-art design tools. Excessive model fidelity including drivetrain complexity, gearbox complexity, excitation sources, and imperfections, significantly increases computational time, but may not provide a commensurate increase in the value of the results. Essential designparameters are evaluated, including the planetary load-sharing factor, gear tooth load distribution, and sun orbit motion. Based on the sensitivity study results, recommendations for the minimum model fidelities are provided.

Stimulated Brillouin scattering continuous wave phase conjugation in step-index fiber optics.

PubMed

Massey, Steven M; Spring, Justin B; Russell, Timothy H

2008-07-21

Continuous wave (CW) stimulated Brillouin scattering (SBS) phase conjugation in step-index optical fibers was studied experimentally and modeled as a function of fiber length. A phase conjugate fidelity over 80% was measured from SBS in a 40 m fiber using a pinhole technique. Fidelity decreases with fiber length, and a fiber with a numerical aperture (NA) of 0.06 was found to generate good phase conjugation fidelity over longer lengths than a fiber with 0.13 NA. Modeling and experiment support previous work showing the maximum interaction length which yields a high fidelity phase conjugate beam is inversely proportional to the fiber NA(2), but find that fidelity remains high over much longer fiber lengths than previous models calculated. Conditions for SBS beam cleanup in step-index fibers are discussed.

Comparison of intervention fidelity between COPE TEEN and an attention-control program in a randomized controlled trial

PubMed Central

Kelly, Stephanie A.; Oswalt, Krista; Melnyk, Bernadette Mazurek; Jacobson, Diana

2015-01-01

Fidelity in implementing an intervention is critical to accurately determine and interpret the effects of an intervention. It is important to monitor the manner in which the behavioral intervention is implemented (e.g. adaptations, delivery as intended and dose). Few interventions are implemented with 100% fidelity. In this study, high school health teachers implemented the intervention. To attribute study findings to the intervention, it was vital to know to what degree the intervention was implemented. Therefore, the purposes of this study were to evaluate intervention fidelity and to compare implementation fidelity between the creating opportunities for personal empowerment (COPE) Healthy Lifestyles TEEN (thinking, emotions, exercise, and nutrition) program, the experimental intervention and Healthy Teens, an attention-control intervention, in a randomized controlled trial with 779 adolescents from 11 high schools in the southwest region of the United States. Thirty teachers participated in this study. Findings indicated that the attention-control teachers implemented their intervention with greater fidelity than COPE TEEN teachers. It is possible due to the novel intervention and the teachers’ unfamiliarity with cognitive-behavioral skills building, COPE TEEN teachers had less fidelity. It is important to assess novel skill development prior to the commencement of experimental interventions and to provide corrective feedback during the course of implementation. PMID:25355179

Ensuring treatment fidelity in a multi-site behavioral intervention study: implementing NIH Behavior Change Consortium recommendations in the SMART trial.

PubMed

Robb, Sheri L; Burns, Debra S; Docherty, Sharron L; Haase, Joan E

2011-11-01

The Stories and Music for Adolescent/Young Adult Resilience during Transplant (SMART) study (R01NR008583; U10CA098543; U10CA095861) is an ongoing multi-site Children's Oncology Group randomized clinical trial testing the efficacy of a therapeutic music video intervention for adolescents/young adults (11-24 years of age) with cancer undergoing stem cell transplant. Treatment fidelity strategies from our trial are consistent with the National Institutes of Health (NIH) Behavior Change Consortium Treatment Fidelity Workgroup (BCC) recommendations and provide a successful working model for treatment fidelity implementation in a large, multi-site behavioral intervention study. In this paper, we summarize 20 specific treatment fidelity strategies used in the SMART trial and how these strategies correspond with NIH BCC recommendations in five specific areas: (1) study design, (2) training providers, (3) delivery of treatment, (4) receipt of treatment, and (5) enactment of treatment skills. Increased use and reporting of treatment fidelity procedures is essential in advancing the reliability and validity of behavioral intervention research. The SMART trial provides a strong model for the application of fidelity strategies to improve scientific findings and addresses the absence of published literature, illustrating the application of BCC recommendations in behavioral intervention studies. Copyright © 2010 John Wiley & Sons, Ltd.

High Fidelity System Simulation of Multiple Components in Support of the UEET Program

NASA Technical Reports Server (NTRS)

Plybon, Ronald C.; VanDeWall, Allan; Sampath, Rajiv; Balasubramaniam, Mahadevan; Mallina, Ramakrishna; Irani, Rohinton

2006-01-01

The High Fidelity System Simulation effort has addressed various important objectives to enable additional capability within the NPSS framework. The scope emphasized High Pressure Turbine and High Pressure Compressor components. Initial effort was directed at developing and validating intermediate fidelity NPSS model using PD geometry and extended to high-fidelity NPSS model by overlaying detailed geometry to validate CFD against rig data. Both "feedforward" and feedback" approaches of analysis zooming was employed to enable system simulation capability in NPSS. These approaches have certain benefits and applicability in terms of specific applications "feedback" zooming allows the flow-up of information from high-fidelity analysis to be used to update the NPSS model results by forcing the NPSS solver to converge to high-fidelity analysis predictions. This apporach is effective in improving the accuracy of the NPSS model; however, it can only be used in circumstances where there is a clear physics-based strategy to flow up the high-fidelity analysis results to update the NPSS system model. "Feed-forward" zooming approach is more broadly useful in terms of enabling detailed analysis at early stages of design for a specified set of critical operating points and using these analysis results to drive design decisions early in the development process.

Detection mechanism of perovskite BFO (1 1 1) membrane for FOX-7 and TATB gases: molecular-scale insight into sensing ultratrace explosives

NASA Astrophysics Data System (ADS)

Bian, Liang; Li, Hai-long; Song, Mian-Xin; Dong, Fa-Qin; Zhang, Xiao-yan; Hou, Wen-ping

2017-03-01

Perovskite bismuth ferrite-BFO (1 1 1) membranes, as potential-sensitive electrochemical sensors, are investigated for the detection of high-energy-density materials by molecular dynamics (MD) and density functional theory (DFT) calculations. For the detection mechanism of the sensitive 1, 1-diamino-2, 2-dinitroethylene (FOX-7) gases, both a cation bridge and electrostatic models can be used to explain the STM signatures as 0.02-0.04 V (single) and 0.03~0.05 V (coverage) over a wide range (0-0.1 V) of bias voltages. For insensitive 1, 3, 5-triamino-2, 4, 6-trinitrobenzene (TATB) gases interacting with the surface of a BFO (1 1 1) membrane, the charge signature can be as high as 0.08 V (coverage: 0.06 V). Analysis indicates a significant difference from the detection mechanism observed for FOX-7 gases; that is, the molecularly intact bidentate bridge configuration with only -\\text{NO}2- bonds binds to both Fe and Bi atoms. These differences are attributed so that the surface O2- of BFO will capture a part of the surface electron of the -NO2 group, creating a 2p-hole defect (h+) which annihilates a spinning upward (↑) Fe3+, forming a spinning downward (↓) Fe2+. The -NO2 electron decreases 0.35 e (single FOX-7; coverage FOX-7: 0.24 e) and 0.56 e (single TATB; coverage TATB: 0.06 e). Such a system could open up new ideas in the design and application of BFO-based sensors.

Assessing the link between implementation fidelity and health outcomes for a trial of intensive case management by community health workers: a mixed methods study protocol.

PubMed

Schmidt, Barbara; Watt, Kerrianne; McDermott, Robyn; Mills, Jane

2017-07-17

Better systems of care are required to address chronic disease in Indigenous people to ensure they can access all their care needs. Health research has produced evidence about effective models of care and chronic disease strategies to address Indigenous health, however the transfer of research findings into routine clinical practice has proven challenging. Complex interventions, such as those related to chronic disease, have many components that are often poorly implemented and hence rarely achieve implementation fidelity. Implementation fidelity is "the degree to which programs are implemented as intended by the program developer". Knowing if an intervention was implemented as planned is fundamental to knowing what has contributed to the success of an intervention. The aim of this study is to adapt the implementation fidelity framework developed by Keith et al. and apply it to the intervention implemented in phase 1 of the Getting Better at Chronic Care in North Queensland study. The objectives are to quantify the level of implementation fidelity achieved during phase 1 of the study, measure the association between implementation fidelity and health outcomes and to explore the features of the primary health care system that contributed to improved health outcomes. A convergent parallel mixed methods study design will be used to develop a process for assessing implementation fidelity. Information collected via a questionnaire and routine data generated during phase 1 of the study will be used to explain the context for the intervention in each site and develop an implementation fidelity score for each component of the intervention. A weighting will be applied to each component of the intervention to calculate the overall implementation score for each participating community. Statistical analysis will assess the level of association between implementation fidelity scores and health outcomes. Health services research seeks to find solutions to social and technical problems to improve health outcomes. The development of a tool and methodology for assessing implementation fidelity in the Indigenous primary health care context will help address some of the barriers to the translation of research into practice. ACTRN12610000812099 : 29.9.2010.

Value-based payment in implementing evidence-based care: the Mental Health Integration Program in Washington state.

PubMed

Bao, Yuhua; McGuire, Thomas G; Chan, Ya-Fen; Eggman, Ashley A; Ryan, Andrew M; Bruce, Martha L; Pincus, Harold Alan; Hafer, Erin; Unützer, Jürgen

2017-01-01

To assess the role of value-based payment (VBP) in improving fidelity and patient outcomes in community implementation of an evidence-based mental health intervention, the Collaborative Care Model (CCM). Retrospective study based on a natural experiment. We used the clinical tracking data of 1806 adult patients enrolled in a large implementation of the CCM in community health clinics in Washington state. VBP was initiated in year 2 of the program, creating a natural experiment. We compared implementation fidelity (measured by 3 process-of-care elements of the CCM) between patient-months exposed to VBP and patient-months not exposed to VBP. A series of regressions were estimated to check robustness of findings. We estimated a Cox proportional hazard model to assess the effect of VBP on time to achieving clinically significant improvement in depression (measured based on changes in depression symptom scores over time). Estimated marginal effects of VBP on fidelity ranged from 9% to 30% of the level of fidelity had there been no exposure to VBP (P <.05 for every fidelity measure). Improvement in fidelity in response to VBP was greater among providers with a larger patient panel and among providers with a lower level of fidelity at baseline. Exposure to VBP was associated with an adjusted hazard ratio of 1.45 (95% confidence interval, 1.04-2.03) for achieving clinically significant improvement in depression. VBP improved fidelity to key elements of the CCM, both directly incentivized and not explicitly incentivized by the VBP, and improved patient depression outcomes.

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

USGS Publications Warehouse

Hayden, Todd A.; Binder, Thomas; Holbrook, Christopher; Vandergoot, Christopher; Fielder, David G.; Cooke, Steven J.; Dettmers, John M.; Krueger, Charles C.

2018-01-01

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.

Fidelity Failures in Brief Strategic Family Therapy for Adolescent Drug Abuse: A Clinical Analysis.

PubMed

Lebensohn-Chialvo, Florencia; Rohrbaugh, Michael J; Hasler, Brant P

2018-04-30

As evidence-based family treatments for adolescent substance use and conduct problems gain traction, cutting edge research moves beyond randomized efficacy trials to address questions such as how these treatments work and how best to disseminate them to community settings. A key factor in effective dissemination is treatment fidelity, which refers to implementing an intervention in a manner consistent with an established manual. While most fidelity research is quantitative, this study offers a qualitative clinical analysis of fidelity failures in a large, multisite effectiveness trial of Brief Strategic Family Therapy (BSFT) for adolescent drug abuse, where BSFT developers trained community therapists to administer this intervention in their own agencies. Using case notes and video recordings of therapy sessions, an independent expert panel first rated 103 cases on quantitative fidelity scales grounded in the BSFT manual and the broader structural-strategic framework that informs BSFT intervention. Because fidelity was generally low, the panel reviewed all cases qualitatively to identify emergent types or categories of fidelity failure. Ten categories of failures emerged, characterized by therapist omissions (e.g., failure to engage key family members, failure to think in threes) and commissions (e.g., off-model, nonsystemic formulations/interventions). Of these, "failure to think in threes" appeared basic and particularly problematic, reflecting the central place of this idea in structural theory and therapy. Although subject to possible bias, our observations highlight likely stumbling blocks in exporting a complex family treatment like BSFT to community settings. These findings also underscore the importance of treatment fidelity in family therapy research. © 2018 Family Process Institute.

Teaching elliptical excision skills to novice medical students: a randomized controlled study comparing low- and high-fidelity bench models.

PubMed

Denadai, Rafael; Oshiiwa, Marie; Saad-Hossne, Rogério

2014-03-01

The search for alternative and effective forms of training simulation is needed due to ethical and medico-legal aspects involved in training surgical skills on living patients, human cadavers and living animals. To evaluate if the bench model fidelity interferes in the acquisition of elliptical excision skills by novice medical students. Forty novice medical students were randomly assigned to 5 practice conditions with instructor-directed elliptical excision skills' training (n = 8): didactic materials (control); organic bench model (low-fidelity); ethylene-vinyl acetate bench model (low-fidelity); chicken legs' skin bench model (high-fidelity); or pig foot skin bench model (high-fidelity). Pre- and post-tests were applied. Global rating scale, effect size, and self-perceived confidence based on Likert scale were used to evaluate all elliptical excision performances. The analysis showed that after training, the students practicing on bench models had better performance based on Global rating scale (all P < 0.0000) and felt more confident to perform elliptical excision skills (all P < 0.0000) when compared to the control. There was no significant difference (all P > 0.05) between the groups that trained on bench models. The magnitude of the effect (basic cutaneous surgery skills' training) was considered large (>0.80) in all measurements. The acquisition of elliptical excision skills after instructor-directed training on low-fidelity bench models was similar to the training on high-fidelity bench models; and there was a more substantial increase in elliptical excision performances of students that trained on all simulators compared to the learning on didactic materials.

The assessment of fidelity in a motor speech-treatment approach

PubMed Central

Hayden, Deborah; Namasivayam, Aravind Kumar; Ward, Roslyn

2015-01-01

Objective To demonstrate the application of the constructs of treatment fidelity for research and clinical practice for motor speech disorders, using the Prompts for Restructuring Oral Muscular Phonetic Targets (PROMPT) Fidelity Measure (PFM). Treatment fidelity refers to a set of procedures used to monitor and improve the validity and reliability of behavioral intervention. While the concept of treatment fidelity has been emphasized in medical and allied health sciences, documentation of procedures for the systematic evaluation of treatment fidelity in Speech-Language Pathology is sparse. Methods The development and iterative process to improve the PFM, is discussed. Further, the PFM is evaluated against recommended measurement strategies documented in the literature. This includes evaluating the appropriateness of goals and objectives; and the training of speech–language pathologists, using direct and indirect procedures. Three expert raters scored the PFM to examine inter-rater reliability. Results Three raters, blinded to each other's scores, completed fidelity ratings on three separate occasions. Inter-rater reliability, using Krippendorff's Alpha, was >80% for the PFM on the final scoring occasion. This indicates strong inter-rater reliability. Conclusion The development of fidelity measures for the training of service providers and treatment delivery is important in specialized treatment approaches where certain ‘active ingredients’ (e.g. specific treatment targets and therapeutic techniques) must be present in order for treatment to be effective. The PFM reflects evidence-based practice by integrating treatment delivery and clinical skill as a single quantifiable metric. PFM enables researchers and clinicians to objectively measure treatment outcomes within the PROMPT approach. PMID:26213623

Silicon incorporation in GaAs: From delta-doping to monolayer insertion

NASA Astrophysics Data System (ADS)

Wagner, J.; Newman, R. C.; Roberts, C.

1995-08-01

Raman spectroscopy was used to study the incorporation of Si into doping layers in GaAs, grown by molecular beam epitaxy at a temperature of 400 °C, for Si concentrations ranging from the δ-doping level to a ML coverage. The strength of the scattering by local vibrational modes of substitutional Si was almost constant for Si areal concentration [Si]A in the range 5×1012<[Si]A<5×1013 cm-2 but then decreased, dropping below the detection limit for [Si]A≳3×1014 cm-2. At these concentrations a new vibrational band emerged at a frequency close to 470 cm-1 and developed into the optic zone center phonon of a coherently strained epitaxial layer of Si embedded in GaAs when a coverage of ≊1.5 ML (9.3×1014 cm-2) was reached. These findings strongly indicate that the observed saturation and the eventual decrease of the concentration of substitutional silicon is caused by an increasing incorporation of deposited Si into two-dimensional islands of covalently bonded Si.

The Relationship between Fidelity and Learning in Aviation Training and Assessment.

ERIC Educational Resources Information Center

Noble, Cliff

2002-01-01

Distinguishes the role of fidelity in learning from its role in assessment as a function of skill level. Suggests that the existence of an optimal point beyond which one additional unit of flight-simulator fidelity results in a diminished rate of practical assessment of nonexpert pilot performance. (Contains 33 references.) (Author/JOW)

Using Indices of Fidelity to Intervention Core Components to Identify Program Active Ingredients

ERIC Educational Resources Information Center

Abry, Tashia; Hulleman, Chris S.; Rimm-Kaufman, Sara E.

2015-01-01

Identifying the active ingredients of an intervention--intervention-specific components serving as key levers of change--is crucial for unpacking the intervention black box. Measures of intervention fidelity can be used to identify specific active ingredients, yet such applications are rare. We illustrate how fidelity measures can be used to…

Treatment Fidelity in Social Work Intervention Research: A Review of Published Studies

ERIC Educational Resources Information Center

Naleppa, Matthias J.; Cagle, John G.

2010-01-01

Objectives: This study investigated treatment fidelity in social work research. Method: The authors systematically reviewed all articles published in five prominent social work journals over a 5- year period. Sixty-three outcome studies were identified and reviewed for how well treatment fidelity was monitored using eight review criteria. Results:…

Treatment Fidelity among Family Health Promoters Delivering a Physical Activity and Nutrition Intervention to Immigrant and Refugee Families

ERIC Educational Resources Information Center

Bronars, Carrie A.; Hanza, Marcelo M.; Meiers, Sonja J.; Patten, Christi A.; Clark, Matthew M.; Nigon, Julie A.; Weis, Jennifer A.; Wieland, Mark L.; Sia, Irene G.

2017-01-01

Lack of treatment fidelity can be an important source of variation affecting the credibility and utility of outcomes from behavioral intervention research. Development and implementation of a well-designed treatment fidelity plan, especially with research involving underserved populations, requires careful conceptualization of study needs in…

A Narrative Review of Generic Intervention Fidelity Measures

ERIC Educational Resources Information Center

Di Rezze, Briano; Law, Mary; Gorter, Jan Willem; Eva, Kevin; Pollock, Nancy

2012-01-01

To increase the rigor of pediatric rehabilitation research, there is a need to evaluate the degree to which an intervention is conducted as planned (i.e., fidelity). Generic fidelity measures evaluate more than one intervention and often include nonspecific attributes of the therapy process common to both interventions. The objective of this study…

Implementation Fidelity of a Voluntary Sector-Led Diabetes Education Programme

ERIC Educational Resources Information Center

Kok, Michele S. Y.; Jones, Mat; Solomon-Moore, Emma; Smith, Jane R.

2018-01-01

Purpose: The quality of voluntary sector-led community health programmes is an important concern for service users, providers and commissioners. Research on the fidelity of programme implementation offers a basis for assessing and further enhancing practice. The purpose of this paper is to report on the fidelity assessment of Living Well Taking…

Assessing Implementation Fidelity: Challenges as Seen through the Lens of Two Experimental Studies

ERIC Educational Resources Information Center

Vig, Rozy; Taylor, Megan W.; Star, Jon R.; Chao, Theodore

2014-01-01

The concept of "implementation fidelity" is broadly used to capture the extent to which an intervention is executed as intended by the designers of the intervention (Century, Rudnick, & Freeman, 2010; Huntley, 2005, McNaught, Tarr, & Sears, 2010, Munter, 2010). Though implementation fidelity instruments are often used to assess…

Assessing Fidelity of Implementation of an Unprescribed, Diagnostic Mathematics Intervention

ERIC Educational Resources Information Center

Munter, Charles; Wilhelm, Anne Garrison; Cobb, Paul; Cordray, David S.

2014-01-01

This article draws on previously employed methods for conducting fidelity studies and applies them to an evaluation of an unprescribed intervention. We document the process of assessing the fidelity of implementation of the Math Recovery first-grade tutoring program, an unprescribed, diagnostic intervention. We describe how we drew on recent…

75 FR 42749 - Fidelity National Financial, Inc.; Analysis of the Agreement Containing Consent Order to Aid...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-22

... FEDERAL TRADE COMMISSION [File No. 091 0032] Fidelity National Financial, Inc.; Analysis of the... prohibiting unfair or deceptive acts or practices or unfair methods of competition. The attached Analysis to... comments electronically or in paper form. Comments should refer to ``Fidelity National Financial, File No...

Evidence, Fidelity, and Organisational Rationales: Multiple Uses of Motivational Interviewing in a Social Services Agency

ERIC Educational Resources Information Center

Björk, Alexander

2016-01-01

In discussions and empirical investigations of the implementation of evidence-based interventions there is often a narrow focus on treatment fidelity. Studying a social services agency trying to incorporate Motivational Interviewing (MI), commonly regarded as evidence-based, this paper problematises a one-sided attention to treatment fidelity by…

Differences in Fidelity of Implementation Measures: What Videos and Surveys Reveal about Algebra Instruction

ERIC Educational Resources Information Center

Durkin, Kelley; Pollack, Courtney; Star, Jon R.; Rittle-Johnson, Bethany

2012-01-01

The current paper investigated the following research questions regarding measures of fidelity: (1) Is there a significant relationship between two different measures of fidelity of implementation: a survey of instructional practices and coded videos of classroom lessons? Does the strength of this relationship differ between treatment and control…

Economical Unsteady High-Fidelity Aerodynamics for Structural Optimization with a Flutter Constraint

NASA Technical Reports Server (NTRS)

Bartels, Robert E.; Stanford, Bret K.

2017-01-01

Structural optimization with a flutter constraint for a vehicle designed to fly in the transonic regime is a particularly difficult task. In this speed range, the flutter boundary is very sensitive to aerodynamic nonlinearities, typically requiring high-fidelity Navier-Stokes simulations. However, the repeated application of unsteady computational fluid dynamics to guide an aeroelastic optimization process is very computationally expensive. This expense has motivated the development of methods that incorporate aspects of the aerodynamic nonlinearity, classical tools of flutter analysis, and more recent methods of optimization. While it is possible to use doublet lattice method aerodynamics, this paper focuses on the use of an unsteady high-fidelity aerodynamic reduced order model combined with successive transformations that allows for an economical way of utilizing high-fidelity aerodynamics in the optimization process. This approach is applied to the common research model wing structural design. As might be expected, the high-fidelity aerodynamics produces a heavier wing than that optimized with doublet lattice aerodynamics. It is found that the optimized lower skin of the wing using high-fidelity aerodynamics differs significantly from that using doublet lattice aerodynamics.

Assessing intervention fidelity in a multi-level, multi-component, multi-site program: the Children's Healthy Living (CHL) program.

PubMed

Butel, Jean; Braun, Kathryn L; Novotny, Rachel; Acosta, Mark; Castro, Rose; Fleming, Travis; Powers, Julianne; Nigg, Claudio R

2015-12-01

Addressing complex chronic disease prevention, like childhood obesity, requires a multi-level, multi-component culturally relevant approach with broad reach. Models are lacking to guide fidelity monitoring across multiple levels, components, and sites engaged in such interventions. The aim of this study is to describe the fidelity-monitoring approach of The Children's Healthy Living (CHL) Program, a multi-level multi-component intervention in five Pacific jurisdictions. A fidelity-monitoring rubric was developed. About halfway during the intervention, community partners were randomly selected and interviewed independently by local CHL staff and by Coordinating Center representatives to assess treatment fidelity. Ratings were compared and discussed by local and Coordinating Center staff. There was good agreement between the teams (Kappa = 0.50, p < 0.001), and intervention improvement opportunities were identified through data review and group discussion. Fidelity for the multi-level, multi-component, multi-site CHL intervention was successfully assessed, identifying adaptations as well as ways to improve intervention delivery prior to the end of the intervention.

The Need for High Fidelity Lunar Regolith Simulants

NASA Technical Reports Server (NTRS)

Gaier, James R.

2008-01-01

The case is made for the need to have high fidelity lunar regolith simulants to verify the performance of structures, mechanisms, and processes to be used on the lunar surface. Minor constituents will in some cases have major consequences. Small amounts of sulfur in the regolith can poison catalysts, and metallic iron on the surface of nano-sized dust particles may cause a dramatic increase in its toxicity. So the definition of a high fidelity simulant is application-dependent. For example, in situ resource utilization will require high fidelity in chemistry, meaning careful attention to the minor components and phases; but some other applications, such as the abrasive effects on suit fabrics, might be relatively insensitive to minor component chemistry while abrasion of some metal components may be highly dependent on trace components. The lunar environment itself will change the surface chemistry of the simulant, so to have a high fidelity simulant it must be used in a high fidelity simulated environment to get an accurate simulation. Research must be conducted to determine how sensitive technologies will be to minor components and environmental factors before they can be dismissed as unimportant.

An Automatic Medium to High Fidelity Low-Thrust Global Trajectory Toolchain; EMTG-GMAT

NASA Technical Reports Server (NTRS)

Beeson, Ryne T.; Englander, Jacob A.; Hughes, Steven P.; Schadegg, Maximillian

2015-01-01

Solving the global optimization, low-thrust, multiple-flyby interplanetary trajectory problem with high-fidelity dynamical models requires an unreasonable amount of computational resources. A better approach, and one that is demonstrated in this paper, is a multi-step process whereby the solution of the aforementioned problem is solved at a lower-fidelity and this solution is used as an initial guess for a higher-fidelity solver. The framework presented in this work uses two tools developed by NASA Goddard Space Flight Center: the Evolutionary Mission Trajectory Generator (EMTG) and the General Mission Analysis Tool (GMAT). EMTG is a medium to medium-high fidelity low-thrust interplanetary global optimization solver, which now has the capability to automatically generate GMAT script files for seeding a high-fidelity solution using GMAT's local optimization capabilities. A discussion of the dynamical models as well as thruster and power modeling for both EMTG and GMAT are given in this paper. Current capabilities are demonstrated with examples that highlight the toolchains ability to efficiently solve the difficult low-thrust global optimization problem with little human intervention.

The Importance of Water for High Fidelity Information Processing and for Life

NASA Technical Reports Server (NTRS)

Hoehler, Tori M.; Pohorille, Andrew

2011-01-01

Is water an absolute prerequisite for life? Life depends on a variety of non-covalent interactions among molecules, the nature of which is determined as much by the solvent in which they occur as by the molecules themselves. Catalysis and information processing, two essential functions of life, require non-covalent molecular recognition with very high specificity. For example, to correctly reproduce a string consisting of 600,000 units of information (e.g ., 600 kilobases, equivalent to the genome of the smallest free living terrestrial organisms) with a 90% success rate requires specificity > 107 : 1 for the target molecule vs. incorrect alternatives. Such specificity requires (i) that the correct molecular association is energetically stabilized by at least 40 kJ/mol relative to alternatives, and (ii) that the system is able to sample among possible states (alternative molecular associations) rapidly enough to allow the system to fall under thermodynamic control and express the energetic stabilization. We argue that electrostatic interactions are required to confer the necessary energetic stabilization vs. a large library of molecular alternatives, and that a solvent with polarity and dielectric properties comparable to water is required for the system to sample among possible states and express thermodynamic control. Electrostatic associations can be made in non-polar solvents, but the resulting complexes are too stable to be "unmade" with sufficient frequency to confer thermodynamic control on the system. An electrostatic molecular complex representing 3 units of information (e.g., 3 base pairs) with specificity > 107 per unit has a stability in non-polar solvent comparable to that of a carbon-carbon bond at room temperature. These considerations suggest that water, or a solvent with properties very like water, is necessary to support high-fidelity information processing, and can therefore be considered a critical prerequisite for life.

How to teach emergency procedural skills in an outdoor environment using low-fidelity simulation.

PubMed

Saxon, Kathleen D; Kapadia, Alison P R; Juneja, Nadia S; Bassin, Benjamin S

2014-03-01

Teaching emergency procedural skills in a wilderness setting can be logistically challenging. To teach these skills as part of a wilderness medicine elective for medical students, we designed an outdoor simulation session with low-fidelity models. The session involved 6 stations in which procedural skills were taught using homemade low-fidelity simulators. At each station, the students encountered a "victim," who required an emergency procedure that was performed using the low-fidelity model. The models are easy and inexpensive to construct, and their design and implementation in the session is described here. Using low-fidelity simulation models in an outdoor setting is an effective teaching tool for emergency wilderness medicine procedures and can easily be reproduced in future wilderness medicine courses. © 2014 Wilderness Medical Society Published by Wilderness Medical Society All rights reserved.

Do Program Implementation Factors or Fidelity Affect Chronic Disease Self-Management Education Programs' Outcomes?

PubMed

Brady, Teresa J; Murphy, Louise B; O'Colmain, Benita J; Hobson, Reeti Desai

2017-09-01

To evaluate whether implementation factors or fidelity moderate chronic disease self-management education program outcomes. Meta-analysis of 34 Arthritis Self-Management Program and Chronic Disease Self-Management Program studies. Community. N = 10 792. Twelve implementation factors: program delivery fidelity and setting and leader and participant characteristics. Eighteen program outcomes: self-reported health behaviors, physical health status, psychological health status, and health-care utilization. Meta-analysis using pooled effect sizes. Modest to moderate statistically significant differences for 4 of 6 implementation factors; these findings were counterintuitive with better outcomes when leaders and participants were unpaid, leaders had less than minimum training, and implementation did not meet fidelity requirements. Exploratory study findings suggest that these interventions tolerate some variability in implementation factors. Further work is needed to identify key elements where fidelity is essential for intervention effectiveness.

Developing effective serious games: the effect of background sound on visual fidelity perception with varying texture resolution.

PubMed

Rojas, David; Kapralos, Bill; Cristancho, Sayra; Collins, Karen; Hogue, Andrew; Conati, Cristina; Dubrowski, Adam

2012-01-01

Despite the benefits associated with virtual learning environments and serious games, there are open, fundamental issues regarding simulation fidelity and multi-modal cue interaction and their effect on immersion, transfer of knowledge, and retention. Here we describe the results of a study that examined the effect of ambient (background) sound on the perception of visual fidelity (defined with respect to texture resolution). Results suggest that the perception of visual fidelity is dependent on ambient sound and more specifically, white noise can have detrimental effects on our perception of high quality visuals. The results of this study will guide future studies that will ultimately aid in developing an understanding of the role that fidelity, and multi-modal interactions play with respect to knowledge transfer and retention for users of virtual simulations and serious games.

Sci-Thur PM – Brachytherapy 05: Surface Collimation Applied to Superficial Flap High Dose-Rate Brachytherapy

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

Liu, Derek; Sabondjian, Eric; Lawrence, Kailin

Purpose: To apply surface collimation for superficial flap HDR skin brachytherapy utilizing common clinical resources and to demonstrate the potential for OAR dose reduction within a clinically relevant setting. Methods: Two phantom setups were used. 3 mm lead collimation was applied to a solid slab phantom to determine appropriate geometries relating to collimation and dwell activation. The same collimation was applied to the temple of an anthropomorphic head phantom to demonstrate lens dose reduction. Each setup was simulated and planned to deliver 400 cGy to a 3 cm circular target to 3 mm depth. The control and collimated irradiations weremore » sequentially measured using calibrated radiochromic films. Results: Collimation for the slab phantom attenuated the dose beyond the collimator opening, decreasing the fall-off distances by half and reducing the area of healthy skin irradiated. Target coverage can be negatively impacted by a tight collimation margin, with the required margin approximated by the primary beam geometric penumbra. Surface collimation applied to the head phantom similarly attenuated the surrounding normal tissue dose while reducing the lens dose from 84 to 68 cGy. To ensure consistent setup between simulation and treatment, additional QA was performed including collimator markup, accounting for collimator placement uncertainties, standoff distance verification, and in vivo dosimetry. Conclusions: Surface collimation was shown to reduce normal tissue dose without compromising target coverage. Lens dose reduction was demonstrated on an anthropomorphic phantom within a clinical setting. Additional QA is proposed to ensure treatment fidelity.« less

HF Propagation sensitivity study and system performance analysis with the Air Force Coverage Analysis Program (AFCAP)

NASA Astrophysics Data System (ADS)

Caton, R. G.; Colman, J. J.; Parris, R. T.; Nickish, L.; Bullock, G.

2017-12-01

The Air Force Research Laboratory, in collaboration with NorthWest Research Associates, is developing advanced software capabilities for high fidelity simulations of high frequency (HF) sky wave propagation and performance analysis of HF systems. Based on the HiCIRF (High-frequency Channel Impulse Response Function) platform [Nickisch et. al, doi:10.1029/2011RS004928], the new Air Force Coverage Analysis Program (AFCAP) provides the modular capabilities necessary for a comprehensive sensitivity study of the large number of variables which define simulations of HF propagation modes. In this paper, we report on an initial exercise of AFCAP to analyze the sensitivities of the tool to various environmental and geophysical parameters. Through examination of the channel scattering function and amplitude-range-Doppler output on two-way propagation paths with injected target signals, we will compare simulated returns over a range of geophysical conditions as well as varying definitions for environmental noise, meteor clutter, and sea state models for Bragg backscatter. We also investigate the impacts of including clutter effects due to field-aligned backscatter from small scale ionization structures at varied levels of severity as defined by the climatologically WideBand Model (WBMOD). In the absence of additional user provided information, AFCAP relies on International Reference Ionosphere (IRI) model to define the ionospheric state for use in 2D ray tracing algorithms. Because the AFCAP architecture includes the option for insertion of a user defined gridded ionospheric representation, we compare output from the tool using the IRI and ionospheric definitions from assimilative models such as GPSII (GPS Ionospheric Inversion).

CubeSat constellation design for air traffic monitoring

NASA Astrophysics Data System (ADS)

Nag, Sreeja; Rios, Joseph L.; Gerhardt, David; Pham, Camvu

2016-11-01

Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring. It thereby provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data were obtained from NASA's Future ATM Concepts Evaluation Tool, for the Alaskan airspace over one day. The results presented were driven by MATLAB and the satellites propagated and coverage calculated using AGI's Satellite Tool. While Ad-hoc and precession spread constellations have been quantitatively evaluated, Walker constellations show the best performance in simulation. Sixteen satellites in two perpendicular orbital planes are shown to provide more than 99% coverage over representative Alaskan airspace and the maximum time gap where any airplane in Alaska is not covered is six minutes, therefore meeting the standard set by the International Civil Aviation Organization to monitor every airplane at least once every fifteen minutes. In spite of the risk of signal collision when multiple packets arrive at the satellite receiver, the proposed constellation shows 99% cumulative probability of reception within four minutes when the airplanes are transmitting every minute, and at 100% reception probability if transmitting every second. Data downlink can be performed using any of the three ground stations of NASA Earth Network in Alaska.

Biochemical analysis of DNA polymerase η fidelity in the presence of replication protein A.

PubMed

Suarez, Samuel C; Toffton, Shannon M; McCulloch, Scott D

2014-01-01

DNA polymerase η (pol η) synthesizes across from damaged DNA templates in order to prevent deleterious consequences like replication fork collapse and double-strand breaks. This process, termed translesion synthesis (TLS), is an overall positive for the cell, as cells deficient in pol η display higher mutation rates. This outcome occurs despite the fact that the in vitro fidelity of bypass by pol η alone is moderate to low, depending on the lesion being copied. One possible means of increasing the fidelity of pol η is interaction with replication accessory proteins present at the replication fork. We have previously utilized a bacteriophage based screening system to measure the fidelity of bypass using purified proteins. Here we report on the fidelity effects of a single stranded binding protein, replication protein A (RPA), when copying the oxidative lesion 7,8-dihydro-8-oxo-guanine(8-oxoG) and the UV-induced cis-syn thymine-thymine cyclobutane pyrimidine dimer (T-T CPD). We observed no change in fidelity dependent on RPA when copying these damaged templates. This result is consistent in multiple position contexts. We previously identified single amino acid substitution mutants of pol η that have specific effects on fidelity when copying both damaged and undamaged templates. In order to confirm our results, we examined the Q38A and Y52E mutants in the same full-length construct. We again observed no difference when RPA was added to the bypass reaction, with the mutant forms of pol η displaying similar fidelity regardless of RPA status. We do, however, observe some slight effects when copying undamaged DNA, similar to those we have described previously. Our results indicate that RPA by itself does not affect pol η dependent lesion bypass fidelity when copying either 8-oxoG or T-T CPD lesions.

Roseate Tern breeding dispersal and fidelity: Responses to two newly restored colony sites

USGS Publications Warehouse

Spendelow, Jeffrey A.; Monticelli, David; Nichols, James D.; Hines, James; Nisbet, Ian; Cormons, Grace; Hays, Helen; Hatch, Jeremy; Mostello, Carolyn

2016-01-01

We used 22 yr of capture–mark–reencounter (CMR) data collected from 1988 to 2009 on about 12,500 birds at what went from three to five coastal colony sites in Massachusetts, New York, and Connecticut, United States, to examine spatial and temporal variation in breeding dispersal/fidelity rates of adult Roseate Terns (Sterna dougallii). At the start of our study, Roseate Terns nested at only one site (Bird Island) in Buzzards Bay, Massachusetts, but two more sites in this bay (Ram and Penikese Islands) were subsequently recolonized and became incorporated into our CMR metapopulation study. We examined four major hypotheses about factors we thought might influence colony-site fidelity and movement rates in the restructured system. We found some evidence that colony-site fidelity remained higher at long-established sites compared with newer ones and that breeding dispersal was more likely to occur among nearby sites than distant ones. Sustained predation at Falkner Island, Connecticut, did not result in a sustained drop in fidelity rates of breeders. Patterns of breeding dispersal differed substantially at the two restored sites. The fidelity of Roseate Terns at Bird dropped quickly after nearby Ram was recolonized in 1994, and fidelity rates for Ram soon approached those for Bird. After an oil spill in Buzzards Bay in April 2003, hazing (deliberate disturbance) of the terns at Ram prior to the start of egg-laying resulted in lowering of fidelity at this site, a decrease in immigration from Bird, and recolonization of Penikese by Roseate Terns. Annual fidelity rates at Penikese increased somewhat several years after the initial recolonization, but they remained much lower there than at all the other sites throughout the study period. The sustained high annual rates of emigration from Penikese resulted in the eventual failure of the restoration effort there, and in 2013, no Roseate Terns nested at this site.

Methodology development for evaluation of selective-fidelity rotorcraft simulation

NASA Technical Reports Server (NTRS)

Lewis, William D.; Schrage, D. P.; Prasad, J. V. R.; Wolfe, Daniel

1992-01-01

This paper addressed the initial step toward the goal of establishing performance and handling qualities acceptance criteria for realtime rotorcraft simulators through a planned research effort to quantify the system capabilities of 'selective fidelity' simulators. Within this framework the simulator is then classified based on the required task. The simulator is evaluated by separating the various subsystems (visual, motion, etc.) and applying corresponding fidelity constants based on the specific task. This methodology not only provides an assessment technique, but also provides a technique to determine the required levels of subsystem fidelity for a specific task.

RNA polymerase II transcriptional fidelity control and its functional interplay with DNA modifications

PubMed Central

Xu, Liang; Wang, Wei; Chong, Jenny; Shin, Ji Hyun; Xu, Jun; Wang, Dong

2016-01-01

Accurate genetic information transfer is essential for life. As a key enzyme involved in the first step of gene expression, RNA polymerase II (Pol II) must maintain high transcriptional fidelity while it reads along DNA template and synthesizes RNA transcript in a stepwise manner during transcription elongation. DNA lesions or modifications may lead to significant changes in transcriptional fidelity or transcription elongation dynamics. In this review, we will summarize recent progress towards understanding the molecular basis of RNA Pol II transcriptional fidelity control and impacts of DNA lesions and modifications on Pol II transcription elongation. PMID:26392149

Innovative Varied-Fidelity Simulation Mobile Teaching Cart and Education Project.

PubMed

Harding, Andrew D; Cullinane Whalen, Kathryn; Silverman, Bradley S

2015-09-01

The use of a varied-fidelity simulation mobile teaching cart is a teaching tool that offers unique advantages in the acute care setting. The cart is used to demonstrate the use of patient monitoring devices, and there are a variety of software tools available with the monitoring technology to ensure that the outputs, including electrocardiographic waves, are analyzed appropriately by nursing staff using this varied-fidelity simulation mobile teaching cart. Bringing varied-fidelity simulation to the nurses' work area is a unique application setting. Copyright © 2015 Emergency Nurses Association. Published by Elsevier Inc. All rights reserved.

Equivalence between entanglement and the optimal fidelity of continuous variable teleportation.

PubMed

Adesso, Gerardo; Illuminati, Fabrizio

2005-10-07

We devise the optimal form of Gaussian resource states enabling continuous-variable teleportation with maximal fidelity. We show that a nonclassical optimal fidelity of N-user teleportation networks is necessary and sufficient for N-party entangled Gaussian resources, yielding an estimator of multipartite entanglement. The entanglement of teleportation is equivalent to the entanglement of formation in a two-user protocol, and to the localizable entanglement in a multiuser one. Finally, we show that the continuous-variable tangle, quantifying entanglement sharing in three-mode Gaussian states, is defined operationally in terms of the optimal fidelity of a tripartite teleportation network.

Generation of high-fidelity four-photon cluster state and quantum-domain demonstration of one-way quantum computing.

PubMed

Tokunaga, Yuuki; Kuwashiro, Shin; Yamamoto, Takashi; Koashi, Masato; Imoto, Nobuyuki

2008-05-30

We experimentally demonstrate a simple scheme for generating a four-photon entangled cluster state with fidelity over 0.860+/-0.015. We show that the fidelity is high enough to guarantee that the produced state is distinguished from Greenberger-Horne-Zeilinger, W, and Dicke types of genuine four-qubit entanglement. We also demonstrate basic operations of one-way quantum computing using the produced state and show that the output state fidelities surpass classical bounds, which indicates that the entanglement in the produced state essentially contributes to the quantum operation.

Kinetics of protein unfolding at interfaces

NASA Astrophysics Data System (ADS)

Yano, Yohko F.

2012-12-01

The conformation of protein molecules is determined by a balance of various forces, including van der Waals attraction, electrostatic interaction, hydrogen bonding, and conformational entropy. When protein molecules encounter an interface, they are often adsorbed on the interface. The conformation of an adsorbed protein molecule strongly depends on the interaction between the protein and the interface. Recent time-resolved investigations have revealed that protein conformation changes during the adsorption process due to the protein-protein interaction increasing with increasing interface coverage. External conditions also affect the protein conformation. This review considers recent dynamic observations of protein adsorption at various interfaces and their implications for the kinetics of protein unfolding at interfaces.

Intervalence transfer of ferrocene moieties adsorbed on electrode surfaces by a conjugated linkage

NASA Astrophysics Data System (ADS)

Chen, Wei; Brown, Lauren E.; Konopelski, Joseph P.; Chen, Shaowei

2009-03-01

Effective intervalence transfer occurred between the metal centers of ferrocene moieties that were adsorbed onto a ruthenium thin film surface by ruthenium-carbene π bonds, a direct verification of Hush's four-decade-old prediction. Electrochemical measurements showed two pairs of voltammetric peaks where the separation of the formal potentials suggested a Class II behavior. Additionally, the potential spacing increased with increasing ferrocene surface coverage, most probably as a consequence of the enhanced contribution from through-space electronic interactions between the metal centers. In contrast, the incorporation of a sp 3 carbon spacer into the ferrocene-ruthenium linkage led to the diminishment of interfacial electronic communication.

Catalysis beyond frontier molecular orbitals: Selectivity in partial hydrogenation of multi-unsaturated hydrocarbons on metal catalysts

PubMed Central

Liu, Wei; Jiang, Yingda; Dostert, Karl-Heinz; O’Brien, Casey P.; Riedel, Wiebke; Savara, Aditya; Schauermann, Swetlana; Tkatchenko, Alexandre

2017-01-01

The mechanistic understanding and control over transformations of multi-unsaturated hydrocarbons on transition metal surfaces remains one of the major challenges of hydrogenation catalysis. To reveal the microscopic origins of hydrogenation chemoselectivity, we performed a comprehensive theoretical investigation on the reactivity of two α,β-unsaturated carbonyls—isophorone and acrolein—on seven (111) metal surfaces: Pd, Pt, Rh, Ir, Cu, Ag, and Au. In doing so, we uncover a general mechanism that goes beyond the celebrated frontier molecular orbital theory, rationalizing the C═C bond activation in isophorone and acrolein as a result of significant surface-induced broadening of high-energy inner molecular orbitals. By extending our calculations to hydrogen-precovered surface and higher adsorbate surface coverage, we further confirm the validity of the “inner orbital broadening mechanism” under realistic catalytic conditions. The proposed mechanism is fully supported by our experimental reaction studies for isophorone and acrolein over Pd nanoparticles terminated with (111) facets. Although the position of the frontier molecular orbitals in these molecules, which are commonly considered to be responsible for chemical interactions, suggests preferential hydrogenation of the C═O double bond, experiments show that hydrogenation occurs at the C═C bond on Pd catalysts. The extent of broadening of inner molecular orbitals might be used as a guiding principle to predict the chemoselectivity for a wide class of catalytic reactions at metal surfaces. PMID:28782033

Flow-induced detachment of red blood cells adhering to surfaces by specific antigen-antibody bonds.

PubMed

Xia, Z; Goldsmith, H L; van de Ven, T G

1994-04-01

Fixed spherical swollen human red blood cells of blood type B adhering on a glass surface through antigen-antibody bonds to monoclonal mouse antihuman IgM, adsorbed or covalently linked on the surface, were detached by known hydrodynamic forces created in an impinging jet. The dynamic process of detachment of the specifically bound cells was recorded and analyzed. The fraction of adherent cells remaining on the surface decreased with increasing hydrodynamic force. For an IgM coverage of 0.26%, a tangential force on the order of 100 pN was able to detach almost all of the cells from the surface within 20 min. After a given time of exposure to hydrodynamic force, the fraction of adherent cells remaining increased with time, reflecting an increase in adhesion strength. The characteristic time for effective aging was approximately 4 h. Results from experiments in which the adsorbed antibody molecules were immobilized through covalent coupling and from evanescent wave light scattering of adherent cells, imply that deformation of red cells at the contact area was the principal cause for aging, rather than local clustering of the antibody through surface diffusion. Experiments with latex beads specifically bound to red blood cells suggest that, instead of breaking the antigen-antibody bonds, antigen molecules were extracted from the cell membrane during detachment.

High-Fidelity Single-Shot Readout for a Spin Qubit via an Enhanced Latching Mechanism

NASA Astrophysics Data System (ADS)

Harvey-Collard, Patrick; D'Anjou, Benjamin; Rudolph, Martin; Jacobson, N. Tobias; Dominguez, Jason; Ten Eyck, Gregory A.; Wendt, Joel R.; Pluym, Tammy; Lilly, Michael P.; Coish, William A.; Pioro-Ladrière, Michel; Carroll, Malcolm S.

2018-04-01

The readout of semiconductor spin qubits based on spin blockade is fast but suffers from a small charge signal. Previous work suggested large benefits from additional charge mapping processes; however, uncertainties remain about the underlying mechanisms and achievable fidelity. In this work, we study the single-shot fidelity and limiting mechanisms for two variations of an enhanced latching readout. We achieve average single-shot readout fidelities greater than 99.3% and 99.86% for the conventional and enhanced readout, respectively, the latter being the highest to date for spin blockade. The signal amplitude is enhanced to a full one-electron signal while preserving the readout speed. Furthermore, layout constraints are relaxed because the charge sensor signal is no longer dependent on being aligned with the conventional (2,0)-(1,1) charge dipole. Silicon donor-quantum-dot qubits are used for this study, for which the dipole insensitivity substantially relaxes donor placement requirements. One of the readout variations also benefits from a parametric lifetime enhancement by replacing the spin-relaxation process with a charge-metastable one. This provides opportunities to further increase the fidelity. The relaxation mechanisms in the different regimes are investigated. This work demonstrates a readout that is fast, has a one-electron signal, and results in higher fidelity. It further predicts that going beyond 99.9% fidelity in a few microseconds of measurement time is within reach.

Oxytocin modulates social distance between males and females.

PubMed

Scheele, Dirk; Striepens, Nadine; Güntürkün, Onur; Deutschländer, Sandra; Maier, Wolfgang; Kendrick, Keith M; Hurlemann, René

2012-11-14

In humans, interpersonal romantic attraction and the subsequent development of monogamous pair-bonds is substantially predicted by influential impressions formed during first encounters. The prosocial neuropeptide oxytocin (OXT) has been identified as a key facilitator of both interpersonal attraction and the formation of parental attachment. However, whether OXT contributes to the maintenance of monogamous bonds after they have been formed is unclear. In this randomized placebo-controlled trial, we provide the first behavioral evidence that the intranasal administration of OXT stimulates men in a monogamous relationship, but not single ones, to keep a much greater distance (~10-15 cm) between themselves and an attractive woman during a first encounter. This avoidance of close personal proximity occurred in the physical presence of female but not male experimenters and was independent of gaze direction and whether the female experimenter or the subject was moving. We further confirmed this unexpected finding using a photograph-based approach/avoidance task that showed again that OXT only stimulated men in a monogamous relationship to approach pictures of attractive women more slowly. Importantly, these changes cannot be attributed to OXT altering the attitude of monogamous men toward attractive women or their judgments of and arousal by pictures of them. Together, our results suggest that where OXT release is stimulated during a monogamous relationship, it may additionally promote its maintenance by making men avoid signaling romantic interest to other women through close-approach behavior during social encounters. In this way, OXT may help to promote fidelity within monogamous human relationships.

An analytical bond-order potential for carbon

DOE PAGES

Zhou, Xiaowang; Ward, Donald K.; Foster, Michael E.

2015-05-27

Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, themore » potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. The potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. An unlimited number of structures not included in the potential parameterization are encountered, thus the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We also demonstrate that our potential reasonably captures the property trends of important carbon phases. As a result, stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure.« less

An analytical bond-order potential for carbon.

PubMed

Zhou, X W; Ward, D K; Foster, M E

2015-09-05

Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, the potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. Most importantly, the potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. Because an unlimited number of structures not included in the potential parameterization are encountered, the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We demonstrate that our potential reasonably captures the property trends of important carbon phases. Stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure. © 2015 Wiley Periodicals, Inc.

Atomistic calculations of dislocation core energy in aluminium

DOE PAGES

Zhou, X. W.; Sills, R. B.; Ward, D. K.; ...

2017-02-16

A robust molecular dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: it does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield highly converged results regardless of the atomistic system size. Utilizing a high-fidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and Burgers vector. These calculations show that, for the face-centred-cubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elasticmore » energy: Ec = A·sin 2β + B·cos 2β, and this dependence is independent of temperature between 100 and 300 K. By further analysing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and radius of a perfect versus extended dislocation. With our methodology, the dislocation core energy can be accurately accounted for in models of plastic deformation.« less

Atomistic calculations of dislocation core energy in aluminium

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

Zhou, X. W.; Sills, R. B.; Ward, D. K.

A robust molecular dynamics simulation method for calculating dislocation core energies has been developed. This method has unique advantages: it does not require artificial boundary conditions, is applicable for mixed dislocations, and can yield highly converged results regardless of the atomistic system size. Utilizing a high-fidelity bond order potential, we have applied this method in aluminium to calculate the dislocation core energy as a function of the angle β between the dislocation line and Burgers vector. These calculations show that, for the face-centred-cubic aluminium explored, the dislocation core energy follows the same functional dependence on β as the dislocation elasticmore » energy: Ec = A·sin 2β + B·cos 2β, and this dependence is independent of temperature between 100 and 300 K. By further analysing the energetics of an extended dislocation core, we elucidate the relationship between the core energy and radius of a perfect versus extended dislocation. With our methodology, the dislocation core energy can be accurately accounted for in models of plastic deformation.« less

Peridynamic Theory as a New Paradigm for Multiscale Modeling of Sintering

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

Silling, Stewart A.; Abdeljawad, Fadi; Ford, Kurtis Ross

2017-09-01

Sintering is a component fabrication process in which powder is compacted by pressing or some other means and then held at elevated temperature for a period of hours. The powder grains bond with each other, leading to the formation of a solid component with much lower porosity, and therefore higher density and higher strength, than the original powder compact. In this project, we investigated a new way of computationally modeling sintering at the length scale of grains. The model uses a high-fidelity, three-dimensional representation with a few hundred nodes per grain. The numerical model solves the peridynamic equations, in whichmore » nonlocal forces allow representation of the attraction, adhesion, and mass diffusion between grains. The deformation of the grains is represented through a viscoelastic material model. The project successfully demonstrated the use of this method to reproduce experimentally observed features of material behavior in sintering, including densification, the evolution of microstructure, and the occurrence of random defects in the sintered solid.« less

Affinity monolith-integrated poly(methyl methacrylate) microchips for on-line protein extraction and capillary electrophoresis.

PubMed

Sun, Xiuhua; Yang, Weichun; Pan, Tao; Woolley, Adam T

2008-07-01

Immunoaffinity monolith pretreatment columns have been coupled with capillary electrophoresis separation in poly(methyl methacrylate) (PMMA) microchips. Microdevices were designed with eight reservoirs to enable the electrically controlled transport of selected analytes and solutions to carry out integrated immunoaffinity extraction and electrophoretic separation. The PMMA microdevices were fabricated reproducibly and with high fidelity by solvent imprinting and thermal bonding methods. Monoliths with epoxy groups for antibody immobilization were prepared by direct in situ photopolymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in a porogenic solvent consisting of 70% 1-dodecanol and 30% cyclohexanol. Antifluorescein isothiocyanate was utilized as a model affinity group in the monoliths, and the immobilization process was optimized. A mean elution efficiency of 92% was achieved for the monolith-based extraction of fluorescein isothiocyanate (FITC)-tagged human serum albumin. FITC-tagged proteins were purified from a contaminant protein and then separated electrophoretically using these devices. The developed immunoaffinity column/capillary electrophoresis microdevices show great promise for combining sample pretreatment and separation in biomolecular analysis.

Affinity Monolith-Integrated Poly(methyl Methacrylate) Microchips for On-Line Protein Extraction and Capillary Electrophoresis

PubMed Central

Sun, Xiuhua; Yang, Weichun; Pan, Tao; Woolley, Adam T.

2008-01-01

Immunoaffinity monolith pretreatment columns have been coupled with capillary electrophoresis separation in poly(methyl methacrylate) (PMMA) microchips. Microdevices were designed with 8 reservoirs to enable the electrically controlled transport of selected analytes and solutions to carry out integrated immunoaffinity extraction and electrophoretic separation. The PMMA microdevices were fabricated reproducibly and with high fidelity by solvent imprinting and thermal bonding methods. Monoliths with epoxy groups for antibody immobilization were prepared by direct in-situ photopolymerization of glycidyl methacrylate and ethylene dimethacrylate in a porogenic solvent consisting of 70% dodecanol and 30% hexanol. Anti-fluorescein isothiocyanate (FITC) was utilized as a model affinity group in the monoliths, and the immobilization process was optimized. A mean elution efficiency of 92% was achieved for the monolith-based extraction of FITC-tagged human serum albumin. FITC-tagged proteins were purified from a contaminant protein and then separated electrophoretically using these devices. The developed immunoaffinity column/capillary electrophoresis microdevices show great promise for combining sample pretreatment and separation in biomolecular analysis. PMID:18479142

Wearable polyimide-PDMS electrodes for intrabody communication

NASA Astrophysics Data System (ADS)

Moon, Jin-Hee; Baek, Dong Hyun; Choi, Yoon Young; Lee, Kwang Ho; Kim, Hee Chan; Lee, Sang-Hoon

2010-02-01

In this paper, we introduce a novel wearable electrode for an intra-body area network (I-BAN) by employing the advantages of polyimide (PI) which is a well-known substrate material for flexible electrodes and polydimethylsiloxane (PDMS) which is a biocompatible and representative soft-lithography adaptable material. Electrodes were patterned onto thin and flexible PI substrates and encapsulated in PDMS to enhance skin compatibility. For this purpose, we developed an electrode fabrication process on thin PI substrates and a PDMS encapsulation technique by bonding two PDMS layers on the front and back surfaces of the PI electrode. The mechanical property and communication performance of electrodes were characterized through spectrum analysis to optimize the role as an I-BAN electrode. Skin-compatibility and cyto-toxicity tests using human mesenchymal stem cells (hMSCs) were carried out to demonstrate the non-toxicity of the electrode after continuous wearing. Sinusoidal signals of 45 MHz were successfully transmitted with high fidelity between electrodes separated by 30 cm.

Validating a Fidelity Scale to Understand Intervention Effects in Classroom-Based Studies

ERIC Educational Resources Information Center

Buckley, Pamela; Moore, Brooke; Boardman, Alison G.; Arya, Diana J.; Maul, Andrew

2017-01-01

K-12 intervention studies often include fidelity of implementation (FOI) as a mediating variable, though most do not report the validity of fidelity measures. This article discusses the critical need for validated FOI scales. To illustrate our point, we describe the development and validation of the Implementation Validity Checklist (IVC-R), an…

Response to Intervention: An Investigation of Training, Perceptions, and Fidelity of Implementation

ERIC Educational Resources Information Center

Latacha, Kathryn N.

2013-01-01

The authors investigated the extent to which the amount of training in Response to Intervention (RtI) impacts staff members' perceptions of RtI, how staff members' perceptions of RtI relate to their fidelity of implementation, and to what degree staff members' involvement in training influences their fidelity of implementation. A convenience…

Measuring Fidelity of Implementation--Methodological and Conceptual Issues and Challenges. CRESST Report 811

ERIC Educational Resources Information Center

Osmundson, Ellen; Herman, Joan; Ringstaff, Cathy; Dai, Yunyun; Timms, Mike

2012-01-01

A central challenge in efficacy studies centers on the issue of "fidelity of implementation," that is, the extent to which participants use the curriculum specified by curriculum developers. In this study, we describe and discuss a "fidelity of implementation" model using multiple methods and instruments to compare two versions of a science…

Perceptions of Fidelity to Family Group Decision-Making Principles: Examining the Impact of Race, Gender, and Relationship

ERIC Educational Resources Information Center

Rauktis, Mary E.; Huefner, Jonathan; Cahalane, Helen

2011-01-01

This study explored the perceptions of fidelity to family group principles using comparative information from family, friends, and professionals, taking into account race and gender. White respondents felt there was a greater degree of fidelity than did the African American respondents, with other race respondents sometimes rating similarly to…

Concept Maps: A Tool to Prepare for High Fidelity Simulation in Nursing

ERIC Educational Resources Information Center

Daley, Barbara J.; Beman, Sarah Black; Morgan, Sarah; Kennedy, Linda; Sheriff, Mandy

2017-01-01

In this study, the use of concept mapping as a method to prepare for high fidelity simulated learning experiences was investigated. Fourth year baccalaureate nursing students were taught how to use concept maps as a way to prepare for high fidelity simulated nursing experiences. Students prepared concept maps for two simulated experiences…

Applying the Five-Step Model of Fidelity Assessment to a Randomized Experiment of a High School STEM Intervention

ERIC Educational Resources Information Center

Kopp, Jason P.; Hulleman, Chris S.; Harackiewicz, Judith M.; Rozek, Chris

2012-01-01

Assessing fidelity of implementation is becoming increasingly important in education research, in particular as a tool for understanding variations in treatment effectiveness. Fidelity of implementation is defined as "the determination of how well an intervention is implemented in comparison with the original program design during an efficacy…

Enhancing Therapeutic Gains: Examination of Fidelity to the Model for the Intensive Mental Health Program

ERIC Educational Resources Information Center

Randall, Camille J.; Biggs, Bridget K.

2008-01-01

Given that the development of treatment fidelity assessment protocol is an integral but too frequently ignored aspect of clinical trials for psychological treatments, the Intensive Mental Health Program (IMHP) sought to build fidelity activities into training, program evaluation, and clinical recordkeeping from the outset of a 3 year study period.…

Relationship between Systems Coaching and Problem-Solving Implementation Fidelity in a Response-to-Intervention Model

ERIC Educational Resources Information Center

March, Amanda L.; Castillo, Jose M.; Batsche, George M.; Kincaid, Donald

2016-01-01

The literature on RTI has indicated that professional development and coaching are critical to facilitating problem-solving implementation with fidelity. This study examined the extent to which systems coaching related to the fidelity of problem-solving implementation in 31 schools from six districts. Schools participated in three years of a…

High versus Low Theoretical Fidelity Pedometer Intervention Using Social-Cognitive Theory on Steps and Self-Efficacy

ERIC Educational Resources Information Center

Raedeke, Thomas D.; Dlugonski, Deirdre

2017-01-01

Purpose: This study was designed to compare a low versus high theoretical fidelity pedometer intervention applying social-cognitive theory on step counts and self-efficacy. Method: Fifty-six public university employees participated in a 10-week randomized controlled trial with 2 conditions that varied in theoretical fidelity. Participants in the…

Academic Fidelity and Integrity as Attributes of University Online Degree Program Offerings

ERIC Educational Resources Information Center

Gambescia, Stephen F.; Paolucci, Rocco

2009-01-01

As stakeholders continue to discuss, debate, and advocate their positions related to the value of online learning at colleges and universities, one element that will continue to be discussed, regardless of the specific issue at hand, is "academic integrity and fidelity". Academic fidelity of online degree program offerings is defined in this study…

The Relationship between the Fidelity of Project-Based Curriculum Implementation and Foreign Language Teachers' Beliefs in Teaching and Learning

ERIC Educational Resources Information Center

de Fur, Karen

2009-01-01

The purpose of this correlational study was to examine the relationship between fidelity of project-based curriculum implementation and foreign language teachers' beliefs in teaching and learning as constructivist or behaviorist. Quantitative data on teachers' beliefs was collected using a self-administered survey. Quantitative data on fidelity of…

Attenuation of Foot-and-Mouth Disease Virus by Engineered Viral Polymerase Fidelity.

PubMed

Rai, Devendra K; Diaz-San Segundo, Fayna; Campagnola, Grace; Keith, Anna; Schafer, Elizabeth A; Kloc, Anna; de Los Santos, Teresa; Peersen, Olve; Rieder, Elizabeth

2017-08-01

Foot-and-mouth disease virus (FMDV) RNA-dependent RNA polymerase (RdRp) (3D pol ) catalyzes viral RNA synthesis. Its characteristic low fidelity and absence of proofreading activity allow FMDV to rapidly mutate and adapt to dynamic environments. In this study, we used the structure of FMDV 3D pol in combination with previously reported results from similar picornaviral polymerases to design point mutations that would alter replication fidelity. In particular, we targeted Trp237 within conserved polymerase motif A because of the low reversion potential inherent in the single UGG codon. Using biochemical and genetic tools, we show that the replacement of tryptophan 237 with phenylalanine imparts higher fidelity, but replacements with isoleucine and leucine resulted in lower-fidelity phenotypes. Viruses containing these W237 substitutions show in vitro growth kinetics and plaque morphologies similar to those of the wild-type (WT) A 24 Cruzeiro strain in BHK cells, and both high- and low-fidelity variants retained fitness during coinfection with the wild-type virus. The higher-fidelity W237F (W237F HF ) mutant virus was more resistant to the mutagenic nucleoside analogs ribavirin and 5-fluorouracil than the WT virus, whereas the lower-fidelity W237I (W237I LF ) and W237L LF mutant viruses exhibited lower ribavirin resistance. Interestingly, the variant viruses showed heterogeneous and slightly delayed growth kinetics in primary porcine kidney cells, and they were significantly attenuated in mouse infection experiments. These data demonstrate, for a single virus, that either increased or decreased RdRp fidelity attenuates virus growth in animals, which is a desirable feature for the development of safer and genetically more stable vaccine candidates. IMPORTANCE Foot-and-mouth disease (FMD) is the most devastating disease affecting livestock worldwide. Here, using structural and biochemical analyses, we have identified FMDV 3D pol mutations that affect polymerase fidelity. Recombinant FMDVs containing substitutions at 3D pol tryptophan residue 237 were genetically stable and displayed plaque phenotypes and growth kinetics similar to those of the wild-type virus in cell culture. We further demonstrate that viruses harboring either a W237F HF substitution or W237I LF and W237L LF mutations were highly attenuated in animals. Our study shows that obtaining 3D pol fidelity variants by protein engineering based on polymerase structure and function could be exploited for the development of attenuated FMDV vaccine candidates that are safer and more stable than strains obtained by selective pressure via mutagenic nucleotides or adaptation approaches. Copyright © 2017 American Society for Microbiology.

Attenuation of Foot-and-Mouth Disease Virus by Engineered Viral Polymerase Fidelity

PubMed Central

Rai, Devendra K.; Diaz-San Segundo, Fayna; Campagnola, Grace; Keith, Anna; Schafer, Elizabeth A.; Kloc, Anna; de los Santos, Teresa; Peersen, Olve

2017-01-01

ABSTRACT Foot-and-mouth disease virus (FMDV) RNA-dependent RNA polymerase (RdRp) (3Dpol) catalyzes viral RNA synthesis. Its characteristic low fidelity and absence of proofreading activity allow FMDV to rapidly mutate and adapt to dynamic environments. In this study, we used the structure of FMDV 3Dpol in combination with previously reported results from similar picornaviral polymerases to design point mutations that would alter replication fidelity. In particular, we targeted Trp237 within conserved polymerase motif A because of the low reversion potential inherent in the single UGG codon. Using biochemical and genetic tools, we show that the replacement of tryptophan 237 with phenylalanine imparts higher fidelity, but replacements with isoleucine and leucine resulted in lower-fidelity phenotypes. Viruses containing these W237 substitutions show in vitro growth kinetics and plaque morphologies similar to those of the wild-type (WT) A24 Cruzeiro strain in BHK cells, and both high- and low-fidelity variants retained fitness during coinfection with the wild-type virus. The higher-fidelity W237F (W237FHF) mutant virus was more resistant to the mutagenic nucleoside analogs ribavirin and 5-fluorouracil than the WT virus, whereas the lower-fidelity W237I (W237ILF) and W237LLF mutant viruses exhibited lower ribavirin resistance. Interestingly, the variant viruses showed heterogeneous and slightly delayed growth kinetics in primary porcine kidney cells, and they were significantly attenuated in mouse infection experiments. These data demonstrate, for a single virus, that either increased or decreased RdRp fidelity attenuates virus growth in animals, which is a desirable feature for the development of safer and genetically more stable vaccine candidates. IMPORTANCE Foot-and-mouth disease (FMD) is the most devastating disease affecting livestock worldwide. Here, using structural and biochemical analyses, we have identified FMDV 3Dpol mutations that affect polymerase fidelity. Recombinant FMDVs containing substitutions at 3Dpol tryptophan residue 237 were genetically stable and displayed plaque phenotypes and growth kinetics similar to those of the wild-type virus in cell culture. We further demonstrate that viruses harboring either a W237FHF substitution or W237ILF and W237LLF mutations were highly attenuated in animals. Our study shows that obtaining 3Dpol fidelity variants by protein engineering based on polymerase structure and function could be exploited for the development of attenuated FMDV vaccine candidates that are safer and more stable than strains obtained by selective pressure via mutagenic nucleotides or adaptation approaches. PMID:28515297

High Fidelity Virtual Environments: Does Shader Quality or Higher Polygon Count Models Increase Presence and Learning

NASA Astrophysics Data System (ADS)

Horton, Scott

This research study investigated the effects of high fidelity graphics on both learning and presence, or the "sense of being there," inside a Virtual Learning Environment (VLE). Four versions of a VLE on the subject of the element mercury were created, each with a different combination of high and low fidelity polygon models and high and low fidelity shaders. A total of 76 college age (18+ years of age) participants were randomly assigned to one of the four conditions. The participants interacted with the VLE and then completed several posttest measures on learning, presence, and attitudes towards the VLE experience. Demographic information was also collected, including age, computer gameplay experience, number of virtual environments interacted with, gender and time spent in this virtual environment. The data was analyzed as a 2 x 2 between subjects ANOVA. The main effects of shader fidelity and polygon fidelity were both non-significant for both learning and all presence subscales inside the VLE. In addition, there was no significant interaction between shader fidelity and model fidelity. However, there were two significant results on the supplementary variables. First, gender was found to have a significant main effect on all the presence subscales. Females reported higher average levels of presence than their male counterparts. Second, gameplay hours, or the number of hours a participant played computer games per week, also had a significant main effect on participant score on the learning measure. The participants who reported playing 15+ hours of computer games per week, the highest amount of time in the variable, had the highest score as a group on the mercury learning measure while those participants that played 1-5 hours per week had the lowest scores.

Teaching Elliptical Excision Skills to Novice Medical Students: A Randomized Controlled Study Comparing Low- and High-Fidelity Bench Models

PubMed Central

Denadai, Rafael; Oshiiwa, Marie; Saad-Hossne, Rogério

2014-01-01

Background: The search for alternative and effective forms of training simulation is needed due to ethical and medico-legal aspects involved in training surgical skills on living patients, human cadavers and living animals. Aims: To evaluate if the bench model fidelity interferes in the acquisition of elliptical excision skills by novice medical students. Materials and Methods: Forty novice medical students were randomly assigned to 5 practice conditions with instructor-directed elliptical excision skills’ training (n = 8): didactic materials (control); organic bench model (low-fidelity); ethylene-vinyl acetate bench model (low-fidelity); chicken legs’ skin bench model (high-fidelity); or pig foot skin bench model (high-fidelity). Pre- and post-tests were applied. Global rating scale, effect size, and self-perceived confidence based on Likert scale were used to evaluate all elliptical excision performances. Results: The analysis showed that after training, the students practicing on bench models had better performance based on Global rating scale (all P < 0.0000) and felt more confident to perform elliptical excision skills (all P < 0.0000) when compared to the control. There was no significant difference (all P > 0.05) between the groups that trained on bench models. The magnitude of the effect (basic cutaneous surgery skills’ training) was considered large (>0.80) in all measurements. Conclusion: The acquisition of elliptical excision skills after instructor-directed training on low-fidelity bench models was similar to the training on high-fidelity bench models; and there was a more substantial increase in elliptical excision performances of students that trained on all simulators compared to the learning on didactic materials. PMID:24700937

Entanglement entropy and fidelity susceptibility in the one-dimensional spin-1 XXZ chains with alternating single-site anisotropy.

PubMed

Ren, Jie; Liu, Guang-Hua; You, Wen-Long

2015-03-18

We study the fidelity susceptibility in an antiferromagnetic spin-1 XXZ chain numerically. By using the density-matrix renormalization group method, the effects of the alternating single-site anisotropy D on fidelity susceptibility are investigated. Its relation with the quantum phase transition is analyzed. It is found that the quantum phase transition from the Haldane spin liquid to periodic Néel spin solid can be well characterized by the fidelity. Finite size scaling of fidelity susceptibility shows a power-law divergence at criticality, which indicates the quantum phase transition is of second order. The results are confirmed by the second derivative of the ground-state energy. We also study the relationship between the entanglement entropy, the Schmidt gap and quantum phase transitions. Conclusions drawn from these quantum information observables agree well with each other.

The effect of high-fidelity patient simulation on the critical thinking and clinical decision-making skills of new graduate nurses.

PubMed

Maneval, Rhonda; Fowler, Kimberly A; Kays, John A; Boyd, Tiffany M; Shuey, Jennifer; Harne-Britner, Sarah; Mastrine, Cynthia

2012-03-01

This study was conducted to determine whether the addition of high-fidelity patient simulation to new nurse orientation enhanced critical thinking and clinical decision-making skills. A pretest-posttest design was used to assess critical thinking and clinical decision-making skills in two groups of graduate nurses. Compared with the control group, the high-fidelity patient simulation group did not show significant improvement in mean critical thinking or clinical decision-making scores. When mean scores were analyzed, both groups showed an increase in critical thinking scores from pretest to posttest, with the high-fidelity patient simulation group showing greater gains in overall scores. However, neither group showed a statistically significant increase in mean test scores. The effect of high-fidelity patient simulation on critical thinking and clinical decision-making skills remains unclear. Copyright 2012, SLACK Incorporated.

Electro-Optic Frequency Beam Splitters and Tritters for High-Fidelity Photonic Quantum Information Processing

DOE PAGES

Lu, Hsuan-Hao; Lukens, Joseph M.; Peters, Nicholas A.; ...

2018-01-18

In this paper, we report the experimental realization of high-fidelity photonic quantum gates for frequency-encoded qubits and qutrits based on electro-optic modulation and Fourier-transform pulse shaping. Our frequency version of the Hadamard gate offers near-unity fidelity (0.99998±0.00003), requires only a single microwave drive tone for near-ideal performance, functions across the entire C band (1530–1570 nm), and can operate concurrently on multiple qubits spaced as tightly as four frequency modes apart, with no observable degradation in the fidelity. For qutrits, we implement a 3×3 extension of the Hadamard gate: the balanced tritter. This tritter—the first ever demonstrated for frequency modes—attains fidelitymore » 0.9989±0.0004. Finally, these gates represent important building blocks toward scalable, high-fidelity quantum information processing based on frequency encoding.« less

Electro-Optic Frequency Beam Splitters and Tritters for High-Fidelity Photonic Quantum Information Processing

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

Lu, Hsuan-Hao; Lukens, Joseph M.; Peters, Nicholas A.

In this paper, we report the experimental realization of high-fidelity photonic quantum gates for frequency-encoded qubits and qutrits based on electro-optic modulation and Fourier-transform pulse shaping. Our frequency version of the Hadamard gate offers near-unity fidelity (0.99998±0.00003), requires only a single microwave drive tone for near-ideal performance, functions across the entire C band (1530–1570 nm), and can operate concurrently on multiple qubits spaced as tightly as four frequency modes apart, with no observable degradation in the fidelity. For qutrits, we implement a 3×3 extension of the Hadamard gate: the balanced tritter. This tritter—the first ever demonstrated for frequency modes—attains fidelitymore » 0.9989±0.0004. Finally, these gates represent important building blocks toward scalable, high-fidelity quantum information processing based on frequency encoding.« less

High-Fidelity Simulation for Neonatal Nursing Education: An Integrative Review of the Literature.

PubMed

Cooper, Allyson

2015-01-01

The lack of safe avenues to develop neonatal nursing competencies using human subjects leads to the notion that simulation education for neonatal nurses might be an ideal form of education. This integrative literature review compares traditional, teacher-centered education with high-fidelity simulation education for neonatal nurses. It examines the theoretical frameworks used in neonatal nursing education and outlines the advantages of this type of training, including improving communication and teamwork; providing an innovative pedagogical approach; and aiding in skill acquisition, confidence, and participant satisfaction. The importance of debriefing is also examined. High-fidelity simulation is not without disadvantages, including its significant cost, the time associated with training, the need for very complex technical equipment, and increased faculty resource requirements. Innovative uses of high-fidelity simulation in neonatal nursing education are suggested. High-fidelity simulation has great potential but requires additional research to fully prove its efficacy.

Rotorcraft Research at the NASA Vertical Motion Simulator

NASA Technical Reports Server (NTRS)

Aponso, Bimal Lalith; Tran, Duc T.; Schroeder, Jeffrey A.

2009-01-01

In the 1970 s the role of the military helicopter evolved to encompass more demanding missions including low-level nap-of-the-earth flight and operation in severely degraded visual environments. The Vertical Motion Simulator (VMS) at the NASA Ames Research Center was built to provide a high-fidelity simulation capability to research new rotorcraft concepts and technologies that could satisfy these mission requirements. The VMS combines a high-fidelity large amplitude motion system with an adaptable simulation environment including interchangeable and configurable cockpits. In almost 30 years of operation, rotorcraft research on the VMS has contributed significantly to the knowledge-base on rotorcraft performance, handling qualities, flight control, and guidance and displays. These contributions have directly benefited current rotorcraft programs and flight safety. The high fidelity motion system in the VMS was also used to research simulation fidelity. This research provided a fundamental understanding of pilot cueing modalities and their effect on simulation fidelity.

Comment on ``Teleportation of two-mode squeezed states''

NASA Astrophysics Data System (ADS)

He, Guangqiang; Zhang, Jingtao

2011-10-01

We investigate the teleportation scheme of two-mode squeezed states proposed by Adhikari [S. Adhikari , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.77.012337 77, 012337 (2008)]. It uses four-mode entangled states to teleport two-mode squeezed states. The fidelity between the original two-mode squeezed states and teleported ones is calculated. The maximal fidelity value of Adhikari's protocol is 0.38, which is incompatible with the fidelity definition with the maximal value 1. In our opinion, one reason is that they calculate the fidelity for multimodes Gaussian states using the fidelity formula for single-mode ones. Another reason is that the covariance matrix of output states should be what is obtained after applying the linear unitary Bogoliubov operations (two cascaded Fourier transformations) on the covariance matrix given in Eq. (12) in their paper. These two reasons result in the incomparable results. In addition, Adhikari's protocol can be simplified to be easily implemented.

Comment on ''Teleportation of two-mode squeezed states''

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

He Guangqiang; Zhang Jingtao

2011-10-15

We investigate the teleportation scheme of two-mode squeezed states proposed by Adhikari et al.[S. Adhikari et al., Phys. Rev. A 77, 012337 (2008)]. It uses four-mode entangled states to teleport two-mode squeezed states. The fidelity between the original two-mode squeezed states and teleported ones is calculated. The maximal fidelity value of Adhikari's protocol is 0.38, which is incompatible with the fidelity definition with the maximal value 1. In our opinion, one reason is that they calculate the fidelity for multimodes Gaussian states using the fidelity formula for single-mode ones. Another reason is that the covariance matrix of output states shouldmore » be what is obtained after applying the linear unitary Bogoliubov operations (two cascaded Fourier transformations) on the covariance matrix given in Eq. (12) in their paper. These two reasons result in the incomparable results. In addition, Adhikari's protocol can be simplified to be easily implemented.« less

Visual long-term memory has the same limit on fidelity as visual working memory.

PubMed

Brady, Timothy F; Konkle, Talia; Gill, Jonathan; Oliva, Aude; Alvarez, George A

2013-06-01

Visual long-term memory can store thousands of objects with surprising visual detail, but just how detailed are these representations, and how can one quantify this fidelity? Using the property of color as a case study, we estimated the precision of visual information in long-term memory, and compared this with the precision of the same information in working memory. Observers were shown real-world objects in random colors and were asked to recall the colors after a delay. We quantified two parameters of performance: the variability of internal representations of color (fidelity) and the probability of forgetting an object's color altogether. Surprisingly, the fidelity of color information in long-term memory was comparable to the asymptotic precision of working memory. These results suggest that long-term memory and working memory may be constrained by a common limit, such as a bound on the fidelity required to retrieve a memory representation.

Multi-fidelity machine learning models for accurate bandgap predictions of solids

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

Pilania, Ghanshyam; Gubernatis, James E.; Lookman, Turab

Here, we present a multi-fidelity co-kriging statistical learning framework that combines variable-fidelity quantum mechanical calculations of bandgaps to generate a machine-learned model that enables low-cost accurate predictions of the bandgaps at the highest fidelity level. Additionally, the adopted Gaussian process regression formulation allows us to predict the underlying uncertainties as a measure of our confidence in the predictions. In using a set of 600 elpasolite compounds as an example dataset and using semi-local and hybrid exchange correlation functionals within density functional theory as two levels of fidelities, we demonstrate the excellent learning performance of the method against actual high fidelitymore » quantum mechanical calculations of the bandgaps. The presented statistical learning method is not restricted to bandgaps or electronic structure methods and extends the utility of high throughput property predictions in a significant way.« less

Multi-fidelity machine learning models for accurate bandgap predictions of solids

DOE PAGES

Pilania, Ghanshyam; Gubernatis, James E.; Lookman, Turab

2016-12-28

Here, we present a multi-fidelity co-kriging statistical learning framework that combines variable-fidelity quantum mechanical calculations of bandgaps to generate a machine-learned model that enables low-cost accurate predictions of the bandgaps at the highest fidelity level. Additionally, the adopted Gaussian process regression formulation allows us to predict the underlying uncertainties as a measure of our confidence in the predictions. In using a set of 600 elpasolite compounds as an example dataset and using semi-local and hybrid exchange correlation functionals within density functional theory as two levels of fidelities, we demonstrate the excellent learning performance of the method against actual high fidelitymore » quantum mechanical calculations of the bandgaps. The presented statistical learning method is not restricted to bandgaps or electronic structure methods and extends the utility of high throughput property predictions in a significant way.« less

CO dissociation and CO hydrogenation on smooth and ion-bombarded Pd(1 1 1): SFG and XPS spectroscopy at mbar pressures

NASA Astrophysics Data System (ADS)

Rupprechter, G.; Kaichev, V. V.; Unterhalt, H.; Morkel, M.; Bukhtiyarov, V. I.

2004-07-01

The CO dissociation probability on transition metals is often invoked to explain the product distribution (selectivity) of catalytic CO hydrogenation. Along these lines, we have investigated CO adsorption and dissociation on smooth and ion-bombarded Pd(1 1 1) at pressures up to 1 mbar using vibrational sum frequency generation (SFG) and X-ray photoelectron spectroscopy (XPS). Under high pressure, CO adsorbate structures were observed that were identical to high-coverage structures in UHV. On ion-bombarded surfaces an additional species was detected which was attributed to CO bridge bonded to defect (low-coordinated) sites. On both surfaces, no indications of CO dissociation were found even after hours of 0.1 mbar CO exposure. However, exposing CO/H 2 mixtures to ion-bombarded Pd(1 1 1) produced carbonaceous deposits suggesting CH xO species as precursors for CO bond cleavage and that the formation of CH xO is facilitated by surface defects. The relevance of the observations for CO hydrogenation on Pd catalysts is discussed.

Simulation of the spatial frequency-dependent sensitivities of Acoustic Emission sensors

NASA Astrophysics Data System (ADS)

Boulay, N.; Lhémery, A.; Zhang, F.

2018-05-01

Typical configurations of nondestructive testing by Acoustic Emission (NDT/AE) make use of multiple sensors positioned on the tested structure for detecting evolving flaws and possibly locating them by triangulation. Sensors positions must be optimized for ensuring global coverage sensitivity to AE events and minimizing their number. A simulator of NDT/AE is under development to provide help with designing testing configurations and with interpreting measurements. A global model performs sub-models simulating the various phenomena taking place at different spatial and temporal scales (crack growth, AE source and radiation, wave propagation in the structure, reception by sensors). In this context, accurate modelling of sensors behaviour must be developed. These sensors generally consist of a cylindrical piezoelectric element of radius approximately equal to its thickness, without damping and bonded to its case. Sensors themselves are bonded to the structure being tested. Here, a multiphysics finite element simulation tool is used to study the complex behaviour of AE sensor. The simulated behaviour is shown to accurately reproduce the high-amplitude measured contributions used in the AE practice.

Surface Defect Passivation and Reaction of c-Si in H2S.

PubMed

Liu, Hsiang-Yu; Das, Ujjwal K; Birkmire, Robert W

2017-12-26

A unique passivation process of Si surface dangling bonds through reaction with hydrogen sulfide (H 2 S) is demonstrated in this paper. A high-level passivation quality with an effective minority carrier lifetime (τ eff ) of >2000 μs corresponding to a surface recombination velocity of <3 cm/s is achieved at a temperature range of 550-650 °C. X-ray photoelectron spectroscopy (XPS) confirmed the bonding states of Si and S and provides insights into the reaction pathway of Si with H 2 S and other impurity elements both during and after the reaction. Quantitative analysis of XPS spectra showed that the τ eff increases with an increase in the surface S content up to ∼3.5% and stabilizes thereafter, indicative of surface passivation by monolayer coverage of S on the Si surface. However, S passivation of the Si surface is highly unstable because of thermodynamically favorable reaction with atmospheric H 2 O and O 2 . This instability can be eliminated by capping the S-passivated Si surface with a protective thin film such as low-temperature-deposited amorphous silicon nitride.

Fidelity of bats to forest sites revealed from mist-netting recaptures

Treesearch

Roger W. Perry

2011-01-01

Although site fidelity to permanent roost structures by bats is generally known, long-term fidelity to areas such as foraging or drinking sites is unknown. Furthermore, mist-net recaptures of bats over multiple years are rarely reported. Extensive mist-net surveys were conducted over the course of 8 y in the Ouachita National Forest of central Arkansas, United States...

The Fidelity of ’Feel’: Emotional Affordance in Virtual Environments

DTIC Science & Technology

2005-07-01

The Fidelity of “Feel”: Emotional Affordance in Virtual Environments Jacquelyn Ford Morie, Josh Williams, Aimee Dozois, Donat-Pierre Luigi... environment but also the participant. We do this with the focus on what emotional affordances this manipulation will provide. Our first evaluation scenario...emotionally affective VEs. Keywords: Immersive Environments , Virtual Environments , VEs, Virtual Reality, emotion , affordance, fidelity, presence

What Is Essential in Developmental Evaluation? On Integrity, Fidelity, Adultery, Abstinence, Impotence, Long-Term Commitment, Integrity, and Sensitivity in Implementing Evaluation Models

ERIC Educational Resources Information Center

Patton, Michael Quinn

2016-01-01

Fidelity concerns the extent to which a specific evaluation sufficiently incorporates the core characteristics of the overall approach to justify labeling that evaluation by its designated name. Fidelity has traditionally meant implementing a model in exactly the same way each time following the prescribed steps and procedures. The essential…

A Qualitative Analysis of the Concepts of Fidelity and Adaptation in the Implementation of an Evidence-Based HIV Prevention Intervention

ERIC Educational Resources Information Center

Owczarzak, Jill; Broaddus, Michelle; Pinkerton, Steven

2016-01-01

Continued debate about the relative value of fidelity versus adaptation, and lack of clarity about the meaning of fidelity, raise concerns about how frontline service providers resolve similar issues in their daily practice. We use SISTA ("Sisters Informing Sisters on Topics about acquired immune deficiency syndrome"), an evidence-based…

Comparison of Intervention Fidelity between COPE TEEN and an Attention-Control Program in a Randomized Controlled Trial

ERIC Educational Resources Information Center

Kelly, Stephanie A.; Oswalt, Krista; Melnyk, Bernadette Mazurek; Jacobson, Diana

2015-01-01

Fidelity in implementing an intervention is critical to accurately determine and interpret the effects of an intervention. It is important to monitor the manner in which the behavioral intervention is implemented (e.g. adaptations, delivery as intended and dose). Few interventions are implemented with 100% fidelity. In this study, high school…

Summer-fall home-range fidelity of female elk in northwestern Colorado: Implications for aspen management

Treesearch

April M. Brough; R. Justin DeRose; Mary M. Conner; James N. Long

2017-01-01

Understanding the degree of spatial fidelity exhibited by individuals within a species increases our ability to manage for desired future outcomes. Elk (Cervus elaphus) is a closely managed species in the Western US, but there is little research evaluating their summer home-range fidelity. Elk summer-fall homeranges overlap considerably with aspen (Populus tremuloides...

Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

Treesearch

Kathleen Matthews; Haiganoush Preisler

2010-01-01

From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

EBT Fidelity Trajectories Across Training Cohorts Using the Interagency Collaborative Team Strategy

PubMed Central

Hecht, Debra; Aarons, Greg; Fettes, Danielle; Hurlburt, Michael; Ledesma, Karla

2015-01-01

The Interdisciplinary Collaborative Team (ICT) strategy uses front-line providers as adaptation, training and quality control agents for multi-agency EBT implementation. This study tests whether an ICT transmits fidelity to subsequent provider cohorts. SafeCare was implemented by home visitors from multiple community-based agencies contracting with child welfare. Client-reported fidelity trajectories for 5,769 visits, 957 clients and 45 providers were compared using three-level growth models. Provider cohorts trained and live-coached by the ICT attained benchmark fidelity after 12 weeks, and this was sustained. Hispanic clients reported high cultural competency, supporting a cultural adaptation crafted by the ICT. PMID:25586878

EBT Fidelity Trajectories Across Training Cohorts Using the Interagency Collaborative Team Strategy.

PubMed

Chaffin, Mark; Hecht, Debra; Aarons, Greg; Fettes, Danielle; Hurlburt, Michael; Ledesma, Karla

2016-03-01

The Interdisciplinary Collaborative Team (ICT) strategy uses front-line providers as adaptation, training and quality control agents for multi-agency EBT implementation. This study tests whether an ICT transmits fidelity to subsequent provider cohorts. SafeCare was implemented by home visitors from multiple community-based agencies contracting with child welfare. Client-reported fidelity trajectories for 5,769 visits, 957 clients and 45 providers were compared using three-level growth models. Provider cohorts trained and live-coached by the ICT attained benchmark fidelity after 12 weeks, and this was sustained. Hispanic clients reported high cultural competency, supporting a cultural adaptation crafted by the ICT.

How to Measure Motivational Interviewing Fidelity in Randomized Controlled Trials: Practical Recommendations.

PubMed

Jelsma, Judith G M; Mertens, Vera-Christina; Forsberg, Lisa; Forsberg, Lars

2015-07-01

Many randomized controlled trials in which motivational interviewing (MI) is a key intervention make no provision for the assessment of treatment fidelity. This methodological shortcoming makes it impossible to distinguish between high- and low-quality MI interventions, and, consequently, to know whether MI provision has contributed to any intervention effects. This article makes some practical recommendations for the collection, selection, coding and reporting of MI fidelity data, as measured using the Motivational Interviewing Treatment Integrity Code. We hope that researchers will consider these recommendations and include MI fidelity measures in future studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparison of Performance Predictions for New Low-Thrust Trajectory Tools

NASA Technical Reports Server (NTRS)

Polsgrove, Tara; Kos, Larry; Hopkins, Randall; Crane, Tracie

2006-01-01

Several low thrust trajectory optimization tools have been developed over the last 3% years by the Low Thrust Trajectory Tools development team. This toolset includes both low-medium fidelity and high fidelity tools which allow the analyst to quickly research a wide mission trade space and perform advanced mission design. These tools were tested using a set of reference trajectories that exercised each tool s unique capabilities. This paper compares the performance predictions of the various tools against several of the reference trajectories. The intent is to verify agreement between the high fidelity tools and to quantify the performance prediction differences between tools of different fidelity levels.

Commentary: Learning from Variations in Fidelity of Implementation.

PubMed

Balu, Rekha; Doolittle, Fred

2016-12-01

The articles in this special issue discuss efforts to improve academic reading outcomes for students and ways to achieve high implementation fidelity of promising strategies. At times the authors discuss if-and how-strong fidelity is associated with strong outcomes and potentially even impacts (the difference between program and control group outcomes). We want to explore this theme in two ways: (a) learning from the variation in fidelity to think about potential points of entry and levers for improvement in implementation, and (b) broadening the evaluation focus to include "service contrast" as a factor driving impacts on student outcomes. We conclude with suggestions for future research. © 2016 Wiley Periodicals, Inc.

Evaluating Fidelity to a Modified NIATx Process Improvement Strategy for Improving HIV Services in Correctional Facilities.

PubMed

Pankow, Jennifer; Willett, Jennifer; Yang, Yang; Swan, Holly; Dembo, Richard; Burdon, William M; Patterson, Yvonne; Pearson, Frank S; Belenko, Steven; Frisman, Linda K

2018-04-01

In a study aimed at improving the quality of HIV services for inmates, an organizational process improvement strategy using change teams was tested in 14 correctional facilities in 8 US states and Puerto Rico. Data to examine fidelity to the process improvement strategy consisted of quantitative ratings of the structural and process components of the strategy and qualitative notes that explicate challenges in maintaining fidelity to the strategy. Fidelity challenges included (1) lack of communication and leadership within change teams, (2) instability in team membership, and (3) issues with data utilization in decision-making to implement improvements to services delivery.

A high-throughput assay for the comprehensive profiling of DNA ligase fidelity

PubMed Central

Lohman, Gregory J. S.; Bauer, Robert J.; Nichols, Nicole M.; Mazzola, Laurie; Bybee, Joanna; Rivizzigno, Danielle; Cantin, Elizabeth; Evans, Thomas C.

2016-01-01

DNA ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. Ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. In order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates containing even one mismatched base pair. In the current study, we report the use of capillary electrophoresis to rapidly generate mismatch fidelity profiles that interrogate all 256 possible base-pair combinations at a ligation junction in a single experiment. Rapid screening of ligase fidelity in a 96-well plate format has allowed the study of ligase fidelity in unprecedented depth. As an example of this new method, herein we report the ligation fidelity of Thermus thermophilus DNA ligase at a range of temperatures, buffer pH and monovalent cation strength. This screen allows the selection of reaction conditions that maximize fidelity without sacrificing activity, while generating a profile of specific mismatches that ligate detectably under each set of conditions. PMID:26365241

A high-throughput assay for the comprehensive profiling of DNA ligase fidelity.

PubMed

Lohman, Gregory J S; Bauer, Robert J; Nichols, Nicole M; Mazzola, Laurie; Bybee, Joanna; Rivizzigno, Danielle; Cantin, Elizabeth; Evans, Thomas C

2016-01-29

DNA ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. Ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. In order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates containing even one mismatched base pair. In the current study, we report the use of capillary electrophoresis to rapidly generate mismatch fidelity profiles that interrogate all 256 possible base-pair combinations at a ligation junction in a single experiment. Rapid screening of ligase fidelity in a 96-well plate format has allowed the study of ligase fidelity in unprecedented depth. As an example of this new method, herein we report the ligation fidelity of Thermus thermophilus DNA ligase at a range of temperatures, buffer pH and monovalent cation strength. This screen allows the selection of reaction conditions that maximize fidelity without sacrificing activity, while generating a profile of specific mismatches that ligate detectably under each set of conditions. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Spawning site fidelity of wild and hatchery lake trout (Salvelinus namaycush) in northern Lake Huron

USGS Publications Warehouse

Binder, Thomas; Riley, Stephen C.; Holbrook, Christopher; Hansen, Michael J.; Bergstedt, Roger A.; Bronte, Charles R.; He, Ji; Krueger, Charles C.

2016-01-01

Fidelity to high-quality spawning sites helps ensure that adults repeatedly spawn at sites that maximize reproductive success. Fidelity is also an important behavioural characteristic to consider when hatchery-reared individuals are stocked for species restoration, because artificial rearing environments may interfere with cues that guide appropriate spawning site selection. Acoustic telemetry was used in conjunction with Cormack–Jolly–Seber capture–recapture models to compare degree of spawning site fidelity of wild and hatchery-reared lake trout (Salvelinus namaycush) in northern Lake Huron. Annual survival was estimated to be between 77% and 81% and did not differ among wild and hatchery males and females. Site fidelity estimates were high in both wild and hatchery-reared lake trout (ranging from 0.78 to 0.94, depending on group and time filter), but were slightly lower in hatchery-reared fish than in wild fish. The ecological implication of the small difference in site fidelity between wild and hatchery-reared lake trout is unclear, but similarities in estimates suggest that many hatchery-reared fish use similar spawning sites to wild fish and that most return to those sites annually for spawning.

The structural and electronic properties of cleaved silicon (111) surfaces following adsorption of silver

NASA Astrophysics Data System (ADS)

Le Lay, G.; Chauvet, A.; Manneville, M.; Kern, R.

Silver overlayers for coverages ranging from zero to several monolayers are evaporated on vacuum-cleaved (111) silicon surfaces and carefully examined using low-energy electron diffraction (diffraction patterns and I(v) curves), and Auger electron spectroscopy (condensation/desorption curves), with the aim of establishing a closer correlation between the adsorption process, the different superlattices observed (i.e. 7 × 7-R(±19°1), 3 × 3-R(30° ), 3 × 1 and 6 × 1), the growth mechanism of the deposit on the one hand and the electronic properties of the system recently probed using photoemission yield spectroscopy on the other hand. These new results basically confirm the direct relations we had previously shown between the growth mode as monitored with electron diffraction LEED, RHEED, TED and Auger spectroscopy, and the electronic structures as investigated by low energy electron spectroscopy, but permit a deeper insight into the adsorption process at low coverage. At room temperature on the 2 × 1 cleavage structure where the silver-silicon interaction is weak, the adsorbed phase is completed at about 6/7 of a monolayer (θ ≃ 6/7) and a local arrangement of vacancies in the adlayer yields the 7 superstructure, while little effect on the silicon dangling bonds is noticed, but when silver two-dimensional islands (θ > 6/7) growing in a quasi layer fashion have covered the substrate surface. At higher temperatures three-dimensional growth of crystallites occurs after completion of the 3 phase whose saturation coverage increases with condensation temperatures, maxima ranging from θ ˜ 0.7 to θ ˜ 1.0 ( T ˜ 500°C) for different cleaves. This Si(111) 3-Ag surface exhibits again the same dangling bond peak as a clean 2 × 1 Si surface, despite the fact that the interaction between Ag and Si is now rather strong, as is confirmed by desorption experiments ( T ˜ 600°C). We thus critically discuss the geometrical models of this 3 phase previously devised and tentatively propose a new one which accounts better for these recent results, along with models of the 3 × 1 and 6 × 1 structures observed in the course of the desorption process.

Mechanistic Insights on C-O and C-C Bond Activation and Hydrogen Insertion during Acetic Acid Hydrogenation Catalyzed by Ruthenium Clusters in Aqueous Medium

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

Shangguan, Junnan; Olarte, Mariefel V.; Chin, Ya-Huei

Catalytic pathways for acetic acid (CH3COOH) and hydrogen (H2) reactions on dispersed Ru clusters in the aqueous medium and the associated kinetic requirements for C-O and C-C bond cleavages and hydrogen insertion are established from rate and isotopic assessments. CH3COOH reacts with H2 in steps that either retain its carbon backbone and lead to ethanol, ethyl acetate, and ethane (47-95 %, 1-23 %, and 2-17 % carbon selectivities, respectively) or break its C-C bond and form methane (1-43 % carbon selectivities) at moderate temperatures (413-523 K) and H2 pressures (10-60 bar, 298 K). Initial CH3COOH activation is the kinetically relevantmore » step, during which CH3C(O)-OH bond cleaves on a metal site pair at Ru cluster surfaces nearly saturated with adsorbed hydroxyl (OH*) and acetate (CH3COO*) intermediates, forming an adsorbed acetyl (CH3CO*) and hydroxyl (OH*) species. Acetic acid turnover rates increase proportionally with both H2 (10-60 bar) and CH3COOH concentrations at low CH3COOH concentrations (<0.83 M), but decrease from first to zero order as the CH3COOH concentration and the CH3COO* coverages increase and the vacant Ru sites concomitantly decrease. Beyond the initial CH3C(O)-OH bond activation, sequential H-insertions on the surface acetyl species (CH3CO*) lead to C2 products and their derivative (ethanol, ethane, and ethyl acetate) and the competitive C-C bond cleavage of CH3CO* causes the eventual methane formation. The instantaneous carbon selectivities towards C2 species (ethanol, ethane, and ethyl acetate) increase linearly with the concentration of proton-type Hδ+ (derived from carboxylic acid dissociation) and chemisorbed H*. The selectivities towards C2 products decrease with increasing temperature, because of higher observed barriers for C-C bond cleavage than H-insertion. This study offers an interpretation of mechanism and energetics and provides kinetic evidence of carboxylic acid assisted proton-type hydrogen (Hδ+) shuffling during H-insertion steps in the aqueous phase, unlike those in the vapor phase, during the hydrogenation of acetic acid on Ru clusters.« less