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Sample records for achieve reproducible thin

  1. Thin sheets achieve optimal wrapping of liquids

    NASA Astrophysics Data System (ADS)

    Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Christian; Russell, Thomas; Menon, Narayanan

    2015-03-01

    A liquid drop can wrap itself in a sheet using capillary forces [Py et al., PRL 98, 2007]. However, the efficiency of ``capillary origami'' at covering the surface of a drop is hampered by the mechanical cost of bending the sheet. Thinner sheets deform more readily by forming small-scale wrinkles and stress-focussing patterns, but it is unclear how coverage efficiency competes with mechanical cost as thickness is decreased, and what wrapping shapes will emerge. We place a thin (~ 100 nm) polymer film on a drop whose volume is gradually decreased so that the sheet covers an increasing fraction of its surface. The sheet exhibits a complex sequence of axisymmetric and polygonal partially- and fully- wrapped shapes. Remarkably, the progression appears independent of mechanical properties. The gross shape, which neglects small-scale features, is correctly predicted by a simple geometric approach wherein the exposed area is minimized. Thus, simply using a thin enough sheet results in maximal coverage.

  2. Reproducibility and off-stoichiometry issues in nickelate thin films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Preziosi, Daniele; Sander, Anke; Barthélémy, Agnès; Bibes, Manuel

    2017-01-01

    Rare-earth nickelates are strongly correlated oxides displaying a metal-to-insulator transition at a temperature tunable by the rare-earth ionic radius. In PrNiO3 and NdNiO3, the transition is very sharp and shows an hysteretic behavior akin to a first-order transition. Both the temperature at which the transition occurs and the associated resistivity change are extremely sensitive to doping and therefore to off-stoichiometry issues that may arise during thin film growth. Here we report that strong deviations in the transport properties of NdNiO3 films can arise in films grown consecutively under nominally identical conditions by pulsed laser deposition; some samples show a well-developed transition with a resistivity change of up to five orders of magnitude while others are metallic down to low temperatures. Through a detailed analysis of in-situ X-ray photoelectron spectroscopy data, we relate this behavior to large levels of cationic off-stoichoimetry that also translate in changes in the Ni valence and bandwidth. Finally, we demonstrate that this lack of reproducibility can be remarkably alleviated by using single-phase NdNiO3 targets.

  3. Ion beam figuring of thin glass plates: achievements and perspectives

    NASA Astrophysics Data System (ADS)

    Civitani, M.; Ghigo, M.; Hołyszko, J.; Vecchi, G.; Basso, S.

    2016-07-01

    Different hot slumping techniques have been developed in the last decade to shape thin glass plates in Wolter-I configuration for high angular resolution x-ray telescopes. The required high quality surface characteristic, both in terms of figure error and of micro-roughness, is challenging and the best results achieved so far are compatible with an HEW of few arcseconds. In order to push forward the technology enabling x-ray optics with final HEW below 1 arcsec, we investigate the ion beam figuring as a deterministic technology which can correct the low frequency components of the residual error directly on thin glasses. In this paper we present the tests performed so far, giving a first assessment on the deterministic process definition. In particular, we report on the results achieved on flat samples of D263 and Eagle glass, focusing on the removal function characterization, the micro-roughness evolution and the plate shape variation.

  4. Achieving Zero Stress in Iridium, Chromium, and Nickle Thin Films

    NASA Technical Reports Server (NTRS)

    Broadway, David M.; Weimer, Jeffrey; Gurgew, Danielle; Lis, Tomasz; Ramsey, Brian D.; O'Dell, Stephen L.; Ames, A.; Bruni, R.

    2015-01-01

    We examine a method for achieving zero intrinsic stress in thin films of iridium, chromium, and nickel deposited by magnetron sputter deposition. The examination of the stress in these materials is motivated by efforts to advance the optical performance of light-weight x-ray space telescopes into the regime of sub-arc second resolution that rely on control of the film stress to values within 10-100 MPa. A characteristic feature of the intrinsic stress behavior in chromium and nickel is their sensitivity to the magnitude and sign of the intrinsic stress with argon gas pressure, including the existence of a critical pressure that results in zero film stress. This critical pressure scales linearly with the film's density. While the effect of stress reversal with argon pressure has been previously reported by Hoffman and others for nickel and chromium, we have discovered a similar behavior for iridium. Additionally, we have identified zero stress in iridium shortly after island coalescence. This feature of film growth is used for achieving a total internal stress of -2.89 MPa for a 15.8 nm thick iridium film. The surface roughness of this low-stress film was examined using scanning probe microscopy (SPM) and x-ray reflectivity (XRR) at CuKa and these results presented and discussed.

  5. Achieving 3-D Nanoparticle Assembly in Nanocomposite Thin Films via Kinetic Control

    DOE PAGES

    Huang, Jingyu; Xiao, Yihan; Xu, Ting

    2017-02-20

    Nanocomposite thin films containing well-ordered nanoparticle (NP) assemblies are ideal candidates for the fabrication of metamaterials. Achieving 3-D assembly of NPs in nanocomposite thin films is thermodynamically challenging as the particle size gets similar to that of a single polymer chain. The entropic penalties of polymeric matrix upon NP incorporation leads to NP aggregation on the film surface or within the defects in the film. Controlling the kinetic pathways of assembly process provides an alternative path forward by arresting the system in nonequilibrium states. Here, we report the thin film 3-D hierarchical assembly of 20 nm NPs in supramolecules withmore » a 30 nm periodicity. By mediating the NP diffusion kinetics in the supramolecular matrix, surface aggregation of NPs was suppressed and NPs coassemble with supramolecules to form new 3-D morphologies in thin films. Lastly, the present studies opened a viable route to achieve designer functional composite thin films via kinetic control.« less

  6. The rationale for patient-reported outcomes surveillance in cancer and a reproducible method for achieving it.

    PubMed

    Smith, Tenbroeck G; Castro, Kathleen M; Troeschel, Alyssa N; Arora, Neeraj K; Lipscomb, Joseph; Jones, Shelton M; Treiman, Katherine A; Hobbs, Connie; McCabe, Ryan M; Clauser, Steven B

    2016-02-01

    Patient-reported outcomes (PROs) measure quality of life, symptoms, patient functioning, and patient perceptions of care; they are essential for gaining a full understanding of cancer care and the impact of cancer on people's lives. Repeatedly captured facility-level and/or population-level PROs (PRO surveillance) could play an important role in quality monitoring and improvement, benchmarking, advocacy, policy making, and research. This article describes the rationale for PRO surveillance and the methods of the Patient Reported Outcomes Symptoms and Side Effects Study (PROSSES), which is the first PRO study to use the American College of Surgeons Commission on Cancer's Rapid Quality Reporting System to identify patients and manage study data flow. The American Cancer Society, the National Cancer Institute, the Commission on Cancer, and RTI International collaborated on PROSSES. PROSSES was conducted at 17 cancer programs that participated in the National Cancer Institute Community Cancer Centers Program among patients diagnosed with locoregional breast or colon cancer. The methods piloted in PROSSES were successful as demonstrated by high eligibility (93%) and response (61%) rates. Differences in clinical and demographic characteristics between respondents and nonrespondents were mostly negligible, with the exception that non-white individuals were somewhat less likely to respond. These methods were consistent across cancer centers and reproducible over time. If repeated and expanded, they could provide PRO surveillance data from patients with cancer on a national scale.

  7. The Need for Reproducibility

    SciTech Connect

    Robey, Robert W.

    2016-06-27

    The purpose of this presentation is to consider issues of reproducibility, specifically it determines whether bitwise reproducible computation is possible, if computational research in DOE improves its publication process, and if reproducible results can be achieved apart from the peer review process?

  8. Reproducibility blues.

    PubMed

    Pulverer, Bernd

    2015-11-12

    Research findings advance science only if they are significant, reliable and reproducible. Scientists and journals must publish robust data in a way that renders it optimally reproducible. Reproducibility has to be incentivized and supported by the research infrastructure but without dampening innovation.

  9. Tailoring the structure of thin film nanocomposite membranes to achieve seawater RO membrane performance.

    PubMed

    Lind, Mary Laura; Eumine Suk, Daniel; Nguyen, The-Vinh; Hoek, Eric M V

    2010-11-01

    Herein we report on the formation and characterization of pure polyamide thin film composite (TFC) and zeolite-polyamide thin film nanocomposite (TFN) reverse osmosis (RO) membranes. Four different physical-chemical post-treatment combinations were applied after the interfacial polymerization reaction to change the molecular structure of polyamide and zeolite-polyamide thin films. Both TFC and TFN hand-cast membranes were more permeable, hydrophilic, and rough than a commercial seawater RO membrane. Salt rejection by TFN membranes was consistently below that of hand-cast TFC membranes; however, two TFN membranes exhibited 32 g/L NaCl rejections above 99.4%, which was better than the commercial membrane under the test conditions employed. The nearly defect-free TFN films that produced such high rejections were achieved only with wet curing, regardless of other post-treatments. Polyamide films formed in the presence of zeolite nanoparticles were less cross-linked than similarly cast pure polyamide films. At the very low nanoparticle loadings evaluated, differences between pure polyamide and zeolite-polyamide membrane water and salt permeability correlated weakly with extent of cross-linking of the polyamide film, which suggests that defects and molecular-sieving largely govern transport through zeolite-polyamide thin film nanocomposite membranes.

  10. Thin-Layer Matrix Sublimation with Vapor-Sorption Induced Co-Crystallization for Sensitive and Reproducible SAMDI-TOF MS Analysis of Protein Biosensors

    NASA Astrophysics Data System (ADS)

    Roth, Michael J.; Kim, Jaekuk; Maresh, Erica M.; Plymire, Daniel A.; Corbett, John R.; Zhang, Junmei; Patrie, Steven M.

    2012-10-01

    Coupling immunoassays on self-assembled monolayers (SAMs) to matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) provides improved assay selectivity compared with traditional photometric detection techniques. We show that thin-layer-transfer (TLT) of α-cyano-4-hydroxycinnaminic acid (CHCA) MALDI matrix via vacuum sublimation followed by organic solvent-based vapor-sorption induced co-crystallization (VIC) results in unique matrix/analyte co-crystallization tendencies that optimizes assay reproducibility and sensitivity. Unique matrix crystal morphologies resulted from VIC solvent vapors, indicating nucleation and crystal growth characteristics depend upon VIC parameters. We observed that CHCA microcrystals generated by methanol VIC resulted in >10× better sensitivity, increased analyte charging, and improved precision compared with dried droplet measurements. The uniformity of matrix/analyte co-crystallization across planar immunoassays directed at intact proteins yielded low spectral variation for single shot replicates (18.5 % relative standard deviation, RSD) and signal averaged spectra (<10 % RSD). We envision that TLT and VIC for MALDI-TOF will enable high-throughput, reproducible array-based immunoassays for protein molecular diagnostic assays in diverse biochemical and clinical applications.

  11. Fundamental performance limits of carbon nanotube thin-film transistors achieved using hybrid molecular dielectrics.

    PubMed

    Sangwan, Vinod K; Ortiz, Rocio Ponce; Alaboson, Justice M P; Emery, Jonathan D; Bedzyk, Michael J; Lauhon, Lincoln J; Marks, Tobin J; Hersam, Mark C

    2012-08-28

    In the past decade, semiconducting carbon nanotube thin films have been recognized as contending materials for wide-ranging applications in electronics, energy, and sensing. In particular, improvements in large-area flexible electronics have been achieved through independent advances in postgrowth processing to resolve metallic versus semiconducting carbon nanotube heterogeneity, in improved gate dielectrics, and in self-assembly processes. Moreover, controlled tuning of specific device components has afforded fundamental probes of the trade-offs between materials properties and device performance metrics. Nevertheless, carbon nanotube transistor performance suitable for real-world applications awaits understanding-based progress in the integration of independently pioneered device components. We achieve this here by integrating high-purity semiconducting carbon nanotube films with a custom-designed hybrid inorganic-organic gate dielectric. This synergistic combination of materials circumvents conventional design trade-offs, resulting in concurrent advances in several transistor performance metrics such as transconductance (6.5 μS/μm), intrinsic field-effect mobility (147 cm(2)/(V s)), subthreshold swing (150 mV/decade), and on/off ratio (5 × 10(5)), while also achieving hysteresis-free operation in ambient conditions.

  12. Highly transparent and reproducible nanocrystalline ZnO and AZO thin films grown by room temperature pulsed-laser deposition on flexible Zeonor plastic substrates

    NASA Astrophysics Data System (ADS)

    Inguva, Saikumar; Vijayaraghavan, Rajani K.; McGlynn, Enda; Mosnier, Jean-Paul

    2015-09-01

    Zeonor plastics are highly versatile due to exceptional optical and mechanical properties which make them the choice material in many novel applications. For potential use in flexible transparent optoelectronic applications, we have investigated Zeonor plastics as flexible substrates for the deposition of highly transparent ZnO and AZO thin films. Films were prepared by pulsed laser deposition at room temperature in oxygen ambient pressures of 75, 150 and 300 mTorr. The growth rate, surface morphology, hydrophobicity and the structural, optical and electrical properties of as-grown films with thicknesses ˜65-420 nm were recorded for the three oxygen pressures. The growth rates were found to be highly linear both as a function of film thickness and oxygen pressure, indicating high reproducibility. All the films were optically smooth, hydrophobic and nanostructured with lateral grain shapes of ˜150 nm wide. This was found compatible with the deposition of condensed nanoclusters, formed in the ablation plume, on a cold and amorphous substrate. Films were nanocrystalline (wurtzite structure), c-axis oriented, with average crystallite size ˜22 nm for ZnO and ˜16 nm for AZO. In-plane compressive stress values of 2-3 GPa for ZnO films and 0.5 GPa for AZO films were found. Films also displayed high transmission greater than 95% in some cases, in the 400-800 nm wavelength range. The low temperature photoluminescence spectra of all the ZnO and AZO films showed intense near band edge emission. A considerable spread from semi-insulating to n-type conductive was observed for the films, with resistivity ˜103 Ω cm and Hall mobility in 4-14 cm2 V-1 s-1 range, showing marked dependences on film thickness and oxygen pressure. Applications in the fields of microfluidic devices and flexible electronics for these ZnO and AZO films are suggested.

  13. Techniques for Achieving Zero Stress in Thin Films of Iridium, Chromium, and Nickel

    NASA Technical Reports Server (NTRS)

    Broadway, David M.; O'Dell, Stephen L.; Ramsey, Brian D.; Weimer, Jeffrey

    2015-01-01

    We examine techniques for achieving zero intrinsic stress in thin films of iridium, chromium, and nickel deposited by magnetron sputter deposition. The intrinsic stress is further correlated to the microstructural features and physical properties such as surface roughness and optical density at a scale appropriate to soft X-ray wavelengths. The examination of the stress in these materials is motivated by efforts to advance the optical performance of light-weight X-ray space telescopes into the regime of sub-arcsecond resolution through various deposition techniques that rely on control of the film stress to values within 10-100 MPa. A characteristic feature of the intrinsic stress behavior in chromium and nickel is their sensitivity to the magnitude and sign of the intrinsic stress with argon gas pressure and deposition rate, including the existence of a critical argon process pressure that results in zero film stress which scales linearly with the atomic mass of the sputtered species. While the effect of stress reversal with argon pressure has been previously reported by Hoffman and others for nickel and chromium, we report this effect for iridium. In addition to stress reversal, we identify zero stress in the optical functioning iridium layer shortly after island coalescence for low process pressures at a film thickness of approximately 35nm. The measurement of the low values of stress during deposition was achieved with the aid of a sensitive in-situ instrument capable of a minimum detectable level of stress, assuming a 35nm thick film, in the range of 0.40-6.0 MPa for <111> oriented crystalline silicon substrate thicknesses of 70-280 microns, respectively.

  14. Glucose-assisted reduction achieved transparent p-type cuprous oxide thin film by a solution method

    NASA Astrophysics Data System (ADS)

    Nie, Sha; Sun, Jian; Gong, Hao; Chen, Zequn; Huang, Yifei; Xu, Jianmei; Zhao, Ling; Zhou, Wei; Wang, Qing

    2016-08-01

    The fabrication of p-type cuprous oxide thin film via a cheap and simple chemical method has been known as challenging. We first find that glucose can assist reduce Cu to a lower valence state in the preparation of cuprous oxide films by the sol-gel method. By first adding glucose in the sol as reducing agent, oxidation from the oxygen in the environment is limited and transparent p-type cuprous oxide films are eventually achieved under optimized experimental conditions. We have developed a p-type cuprous oxide thin film with an optimal Hall mobility of ∼8 cm2/Vs and an optical transmittance of 78%.

  15. Achieving Low-Electrical-Resistance WO3:Li Nanostructured Thin Films Using Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Asghari, Zahra; Eshghi, Hosein

    2017-03-01

    We have grown 1 wt.%, 5 wt.%, and 10 wt.% Li-doped tungsten oxide thin films on glass substrate using the spray pyrolysis technique and investigated their morphological, structural, optical, and electrical properties. In addition to formation of nanograin coverage, we found that the doped films grew with polycrystalline monoclinic structure having preferred orientation along (200) plane instead of the amorphous undoped structure. The 10 wt.%-doped sample showed the highest visible transmittance (˜95%) and lowest resistivity (˜7.5 Ω cm), together with relatively high ultraviolet (UV) photoluminescence emission at room temperature.

  16. Achieving Low-Electrical-Resistance WO3:Li Nanostructured Thin Films Using Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Asghari, Zahra; Eshghi, Hosein

    2016-12-01

    We have grown 1 wt.%, 5 wt.%, and 10 wt.% Li-doped tungsten oxide thin films on glass substrate using the spray pyrolysis technique and investigated their morphological, structural, optical, and electrical properties. In addition to formation of nanograin coverage, we found that the doped films grew with polycrystalline monoclinic structure having preferred orientation along (200) plane instead of the amorphous undoped structure. The 10 wt.%-doped sample showed the highest visible transmittance (˜95%) and lowest resistivity (˜7.5 Ω cm), together with relatively high ultraviolet (UV) photoluminescence emission at room temperature.

  17. Reproducible resistive switching in the super-thin Bi2FeCrO6 epitaxial film with SrRuO3 bottom electrode

    NASA Astrophysics Data System (ADS)

    Xu, Wenting; Sun, Jiao; Xu, Xijun; Yuan, Guoliang; Zhang, Yongjun; Liu, Junming; Liu, Zhiguo

    2016-10-01

    The reproducible and reliable resistive switching is observed in the ultrathin Bi2FeCrO6 (BFCO) epitaxial film on (001) SrTiO3 substrate with SrRuO3 as the bottom electrode. The as-grown BFCO film allows its ferroelectric polarization switching under external electric field. With a 100-nm-radius tip contacting film surface, a stable bipolar resistive switching was observed through the conductive atomic force microscope. Furthermore, the resistive switching at negative bias was observed and its high/low current ratio is above 15 among a thousand of current versus voltage curves measured by the scanning tunneling microscope with a non-contacting nm-scale tip. It is argued that this transport mechanism is due to quantum tunneling, and the resistive switching in these junctions is because of ferroelectric switching.

  18. Achievement of zero temperature coefficient of resistance with RuO{sub x} thin film resistors

    SciTech Connect

    Kim, Y.T.

    1997-01-01

    The temperature coefficient of resistance (TCR) for an as-deposited RuO{sub 2.2} thin film resistor changes from {minus}131.6 to 1007.95 ppm/{degree}C after the annealing at 600{degree}C for 30 min. Typically, a near zero TCR about 0{plus_minus}0.12 ppm/{degree}C can be obtained after annealing at 300{degree}C for 30 min in an Ar ambient. The changes of TCR from negative to positive is attributed to the grain growth of RuO{sub x} films from fine grain (30{endash}40 {Angstrom}) to a larger one (500{endash}800 {Angstrom}) during the annealing process. Rutherford backscattering spectroscopy and {ital in situ} x-ray photoemission spectroscopy show that the ratio of O/Ru in the RuO{sub x} film decreases from 2.2 to 2.0, due to the out diffusion of oxygen during the annealing process, which is independent of the changes in TCR. {copyright} {ital 1997 American Institute of Physics.}

  19. Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses

    SciTech Connect

    Semperlotti, F. Zhu, H.

    2014-08-07

    In this study, we present an approach to ultrasonic beam-forming and high resolution identification of acoustic sources having critical implications for applications such as structural health monitoring. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. Numerical results show that the ultrasonic beam can be steered by simply tuning the frequency of the excitation. Also, the embedded lens can be designed to achieve sub-wavelength resolution to clustered acoustic sources, which is a typical scenario encountered in incipient structural damage.

  20. Anion control as a strategy to achieve high-mobility and high-stability oxide thin-film transistors.

    PubMed

    Kim, Hyun-Suk; Jeon, Sang Ho; Park, Joon Seok; Kim, Tae Sang; Son, Kyoung Seok; Seon, Jong-Baek; Seo, Seok-Jun; Kim, Sun-Jae; Lee, Eunha; Chung, Jae Gwan; Lee, Hyungik; Han, Seungwu; Ryu, Myungkwan; Lee, Sang Yoon; Kim, Kinam

    2013-01-01

    Ultra-definition, large-area displays with three-dimensional visual effects represent megatrend in the current/future display industry. On the hardware level, such a "dream" display requires faster pixel switching and higher driving current, which in turn necessitate thin-film transistors (TFTs) with high mobility. Amorphous oxide semiconductors (AOS) such as In-Ga-Zn-O are poised to enable such TFTs, but the trade-off between device performance and stability under illumination critically limits their usability, which is related to the hampered electron-hole recombination caused by the oxygen vacancies. Here we have improved the illumination stability by substituting oxygen with nitrogen in ZnO, which may deactivate oxygen vacancies by raising valence bands above the defect levels. Indeed, the stability under illumination and electrical bias is superior to that of previous AOS-based TFTs. By achieving both mobility and stability, it is highly expected that the present ZnON TFTs will be extensively deployed in next-generation flat-panel displays.

  1. Anion control as a strategy to achieve high-mobility and high-stability oxide thin-film transistors

    PubMed Central

    Kim, Hyun-Suk; Jeon, Sang Ho; Park, Joon Seok; Kim, Tae Sang; Son, Kyoung Seok; Seon, Jong-Baek; Seo, Seok-Jun; Kim, Sun-Jae; Lee, Eunha; Chung, Jae Gwan; Lee, Hyungik; Han, Seungwu; Ryu, Myungkwan; Lee, Sang Yoon; Kim, Kinam

    2013-01-01

    Ultra-definition, large-area displays with three-dimensional visual effects represent megatrend in the current/future display industry. On the hardware level, such a “dream” display requires faster pixel switching and higher driving current, which in turn necessitate thin-film transistors (TFTs) with high mobility. Amorphous oxide semiconductors (AOS) such as In-Ga-Zn-O are poised to enable such TFTs, but the trade-off between device performance and stability under illumination critically limits their usability, which is related to the hampered electron-hole recombination caused by the oxygen vacancies. Here we have improved the illumination stability by substituting oxygen with nitrogen in ZnO, which may deactivate oxygen vacancies by raising valence bands above the defect levels. Indeed, the stability under illumination and electrical bias is superior to that of previous AOS-based TFTs. By achieving both mobility and stability, it is highly expected that the present ZnON TFTs will be extensively deployed in next-generation flat-panel displays. PMID:23492854

  2. In Situ Tuning of Magnetization and Magnetoresistance in Fe3O4 Thin Film Achieved with All-Solid-State Redox Device.

    PubMed

    Tsuchiya, Takashi; Terabe, Kazuya; Ochi, Masanori; Higuchi, Tohru; Osada, Minoru; Yamashita, Yoshiyuki; Ueda, Shigenori; Aono, Masakazu

    2016-01-26

    An all-solid-state redox device composed of Fe3O4 thin film and Li(+) ion conducting solid electrolyte was fabricated for use in tuning magnetization and magnetoresistance (MR), which are key factors in the creation of high-density magnetic storage devices. Electrical conductivity, magnetization, and MR were reversibly tuned by Li(+) insertion and removal. Tuning of the various Fe3O4 thin film properties was achieved by donation of an electron to the Fe(3+) ions. This technique should lead to the development of spintronics devices based on the reversible switching of magnetization and spin polarization (P). It should also improve the performance of conventional magnetic random access memory (MRAM) devices in which the ON/OFF ratio has been limited to a small value due to a decrease in P near the tunnel barrier.

  3. Fast Atomic-Scale Elemental Mapping of Crystalline Materials by STEM Energy-Dispersive X-Ray Spectroscopy Achieved with Thin Specimens.

    PubMed

    Lu, Ping; Yuan, Renliang; Zuo, Jian Min

    2017-02-01

    Elemental mapping at the atomic-scale by scanning transmission electron microscopy (STEM) using energy-dispersive X-ray spectroscopy (EDS) provides a powerful real-space approach to chemical characterization of crystal structures. However, applications of this powerful technique have been limited by inefficient X-ray emission and collection, which require long acquisition times. Recently, using a lattice-vector translation method, we have shown that rapid atomic-scale elemental mapping using STEM-EDS can be achieved. This method provides atomic-scale elemental maps averaged over crystal areas of ~few 10 nm2 with the acquisition time of ~2 s or less. Here we report the details of this method, and, in particular, investigate the experimental conditions necessary for achieving it. It shows, that in addition to usual conditions required for atomic-scale imaging, a thin specimen is essential for the technique to be successful. Phenomenological modeling shows that the localization of X-ray signals to atomic columns is a key reason. The effect of specimen thickness on the signal delocalization is studied by multislice image simulations. The results show that the X-ray localization can be achieved by choosing a thin specimen, and the thickness of less than about 22 nm is preferred for SrTiO3 in [001] projection for 200 keV electrons.

  4. Reproducibility in Chemical Research.

    PubMed

    Bergman, Robert G; Danheiser, Rick L

    2016-10-04

    "… To what extent is reproducibility a significant issue in chemical research? How can problems involving irreproducibility be minimized? … Researchers should be aware of the dangers of unconscious investigator bias, all papers should provide adequate experimental detail, and Reviewers have a responsibility to carefully examine papers for adequacy of experimental detail and support for the conclusions …" Read more in the Editorial by Robert G. Bergman and Rick L. Danheiser.

  5. Ultrahigh coercivity and core-shell microstructure achieved in oriented Nd-Fe-B thin films diffusion-processed with Dy-based alloys

    NASA Astrophysics Data System (ADS)

    Zhang, Tongbo; Zhou, Xiaoqian; Yu, Dedong; Fu, Yanqing; Li, Guojian; Cui, Weibin; Wang, Qiang

    2017-01-01

    Ultrahigh ambient coercivities of 4 T were achieved in Nd-Fe-B benchmark thin film with coercivity of 1.06 T by diffusion-processing with Dy, Dy70Cu30 and Dy80Ag20 alloy layer. High texture and good squareness were obtained. In triple-junction regions, Dy element was found to be immiscible with Nd element. Microstructure observation indicated the typical gradient elementary distribution. Unambiguous core/shell microstructure was characterized by transition electron microscopy. Due to the enhanced ambient coercivity, the coercivity temperature stability was also substantially increased.

  6. Achieving Small Structures in Thin NiTi Sheets for Medical Applications with Water Jet and Micro Machining: A Comparison

    NASA Astrophysics Data System (ADS)

    Frotscher, M.; Kahleyss, F.; Simon, T.; Biermann, D.; Eggeler, G.

    2011-07-01

    NiTi shape memory alloys (SMA) are used for a variety of applications including medical implants and tools as well as actuators, making use of their unique properties. However, due to the hardness and strength, in combination with the high elasticity of the material, the machining of components can be challenging. The most common machining techniques used today are laser cutting and electrical discharge machining (EDM). In this study, we report on the machining of small structures into binary NiTi sheets, applying alternative processing methods being well-established for other metallic materials. Our results indicate that water jet machining and micro milling can be used to machine delicate structures, even in very thin NiTi sheets. Further work is required to optimize the cut quality and the machining speed in order to increase the cost-effectiveness and to make both methods more competitive.

  7. Reproducible research in palaeomagnetism

    NASA Astrophysics Data System (ADS)

    Lurcock, Pontus; Florindo, Fabio

    2015-04-01

    The reproducibility of research findings is attracting increasing attention across all scientific disciplines. In palaeomagnetism as elsewhere, computer-based analysis techniques are becoming more commonplace, complex, and diverse. Analyses can often be difficult to reproduce from scratch, both for the original researchers and for others seeking to build on the work. We present a palaeomagnetic plotting and analysis program designed to make reproducibility easier. Part of the problem is the divide between interactive and scripted (batch) analysis programs. An interactive desktop program with a graphical interface is a powerful tool for exploring data and iteratively refining analyses, but usually cannot operate without human interaction. This makes it impossible to re-run an analysis automatically, or to integrate it into a larger automated scientific workflow - for example, a script to generate figures and tables for a paper. In some cases the parameters of the analysis process itself are not saved explicitly, making it hard to repeat or improve the analysis even with human interaction. Conversely, non-interactive batch tools can be controlled by pre-written scripts and configuration files, allowing an analysis to be 'replayed' automatically from the raw data. However, this advantage comes at the expense of exploratory capability: iteratively improving an analysis entails a time-consuming cycle of editing scripts, running them, and viewing the output. Batch tools also tend to require more computer expertise from their users. PuffinPlot is a palaeomagnetic plotting and analysis program which aims to bridge this gap. First released in 2012, it offers both an interactive, user-friendly desktop interface and a batch scripting interface, both making use of the same core library of palaeomagnetic functions. We present new improvements to the program that help to integrate the interactive and batch approaches, allowing an analysis to be interactively explored and refined

  8. Patent Law's Reproducibility Paradox.

    PubMed

    Sherkow, Jacob S

    2017-01-01

    Clinical research faces a reproducibility crisis. Many recent clinical and preclinical studies appear to be irreproducible--their results cannot be verified by outside researchers. This is problematic for not only scientific reasons but also legal ones: patents grounded in irreproducible research appear to fail their constitutional bargain of property rights in exchange for working disclosures of inventions. The culprit is likely patent law’s doctrine of enablement. Although the doctrine requires patents to enable others to make and use their claimed inventions, current difficulties in applying the doctrine hamper or even actively dissuade reproducible data in patents. This Article assesses the difficulties in reconciling these basic goals of scientific research and patent law. More concretely, it provides several examples of irreproducibility in patents on blockbuster drugs--Prempro, Xigris, Plavix, and Avastin--and discusses some of the social costs of the misalignment between good clinical practice and patent doctrine. Ultimately, this analysis illuminates several current debates concerning innovation policy. It strongly suggests that a proper conception of enablement should take into account after-arising evidence. It also sheds light on the true purpose--and limits--of patent disclosure. And lastly, it untangles the doctrines of enablement and utility.

  9. Opening Reproducible Research

    NASA Astrophysics Data System (ADS)

    Nüst, Daniel; Konkol, Markus; Pebesma, Edzer; Kray, Christian; Klötgen, Stephanie; Schutzeichel, Marc; Lorenz, Jörg; Przibytzin, Holger; Kussmann, Dirk

    2016-04-01

    Open access is not only a form of publishing such that research papers become available to the large public free of charge, it also refers to a trend in science that the act of doing research becomes more open and transparent. When science transforms to open access we not only mean access to papers, research data being collected, or data being generated, but also access to the data used and the procedures carried out in the research paper. Increasingly, scientific results are generated by numerical manipulation of data that were already collected, and may involve simulation experiments that are completely carried out computationally. Reproducibility of research findings, the ability to repeat experimental procedures and confirm previously found results, is at the heart of the scientific method (Pebesma, Nüst and Bivand, 2012). As opposed to the collection of experimental data in labs or nature, computational experiments lend themselves very well for reproduction. Some of the reasons why scientists do not publish data and computational procedures that allow reproduction will be hard to change, e.g. privacy concerns in the data, fear for embarrassment or of losing a competitive advantage. Others reasons however involve technical aspects, and include the lack of standard procedures to publish such information and the lack of benefits after publishing them. We aim to resolve these two technical aspects. We propose a system that supports the evolution of scientific publications from static papers into dynamic, executable research documents. The DFG-funded experimental project Opening Reproducible Research (ORR) aims for the main aspects of open access, by improving the exchange of, by facilitating productive access to, and by simplifying reuse of research results that are published over the Internet. Central to the project is a new form for creating and providing research results, the executable research compendium (ERC), which not only enables third parties to

  10. Surface characterization of an energetic material, pentaerythritoltetranitrate (PETN), having a thin coating achieved through a starved addition microencapsulation technique

    SciTech Connect

    Worley, C.M.

    1986-05-07

    The objective of this research was to: (1) determine the nature of a thin coating on an explosive material which was applied using a starved addition microencapsulation technique, (2) understand the coating/crystal bond, and (3) investigate the wettability/adhesion of plastic/solvent combinations using the coating process. The coating used in this work was a Firestone Plastic Company copolymer (FPC-461) of vinylchloride/trifluorochloroethylene in a 1.5/1.0 weight ratio. The energetic explosive examined was pentaerythritoltetranitrate (PETN). The coating process used was starved addition followed by a solvent evaporation technique. Surface analytical studies, completed for characterization of the coating process, show (1) evidence that the polymer coating is present, but not continuous, over the surface of PETN; (2) the average thickness of the polymer coating is between 16-32 A and greater than 44 A, respectively, for 0.5 and 20 wt % coated PETN; (3) no changes in surface chemistry of the polymer or the explosive material following microencapsulation; and (4) the presence of explosive material on the surface of 0.5 wt % FPC-461 coated explosives. 5 refs., 15 figs., 6 tabs.

  11. Statistical test of reproducibility and operator variance in thin-section modal analysis of textures and phenocrysts in the Topopah Spring member, drill hole USW VH-2, Crater Flat, Nye County, Nevada

    SciTech Connect

    Moore, L.M.; Byers, F.M. Jr.; Broxton, D.E.

    1989-06-01

    A thin-section operator-variance test was given to the 2 junior authors, petrographers, by the senior author, a statistician, using 16 thin sections cut from core plugs drilled by the US Geological Survey from drill hole USW VH-2 standard (HCQ) drill core. The thin sections are samples of Topopah Spring devitrified rhyolite tuff from four textural zones, in ascending order: (1) lower nonlithophysal, (2) lower lithopysal, (3) middle nonlithophysal, and (4) upper lithophysal. Drill hole USW-VH-2 is near the center of the Crater Flat, about 6 miles WSW of the Yucca Mountain in Exploration Block. The original thin-section labels were opaqued out with removable enamel and renumbered with alpha-numeric labels. The sliders were then given to the petrographer operators for quantitative thin-section modal (point-count) analysis of cryptocrystalline, spherulitic, granophyric, and void textures, as well as phenocryst minerals. Between operator variance was tested by giving the two petrographers the same slide, and within-operator variance was tested by the same operator the same slide to count in a second test set, administered at least three months after the first set. Both operators were unaware that they were receiving the same slide to recount. 14 figs., 6 tabs.

  12. Thou Shalt Be Reproducible! A Technology Perspective

    PubMed Central

    Mair, Patrick

    2016-01-01

    This article elaborates on reproducibility in psychology from a technological viewpoint. Modern open source computational environments are shown and explained that foster reproducibility throughout the whole research life cycle, and to which emerging psychology researchers should be sensitized, are shown and explained. First, data archiving platforms that make datasets publicly available are presented. Second, R is advocated as the data-analytic lingua franca in psychology for achieving reproducible statistical analysis. Third, dynamic report generation environments for writing reproducible manuscripts that integrate text, data analysis, and statistical outputs such as figures and tables in a single document are described. Supplementary materials are provided in order to get the reader started with these technologies. PMID:27471486

  13. Reproducibility in a multiprocessor system

    SciTech Connect

    Bellofatto, Ralph A; Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Gooding, Thomas M; Haring, Rudolf A; Heidelberger, Philip; Kopcsay, Gerard V; Liebsch, Thomas A; Ohmacht, Martin; Reed, Don D; Senger, Robert M; Steinmacher-Burow, Burkhard; Sugawara, Yutaka

    2013-11-26

    Fixing a problem is usually greatly aided if the problem is reproducible. To ensure reproducibility of a multiprocessor system, the following aspects are proposed; a deterministic system start state, a single system clock, phase alignment of clocks in the system, system-wide synchronization events, reproducible execution of system components, deterministic chip interfaces, zero-impact communication with the system, precise stop of the system and a scan of the system state.

  14. Contextual sensitivity in scientific reproducibility.

    PubMed

    Van Bavel, Jay J; Mende-Siedlecki, Peter; Brady, William J; Reinero, Diego A

    2016-06-07

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher's degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed "hidden moderators") between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility.

  15. Open Science and Research Reproducibility

    PubMed Central

    Munafò, Marcus

    2016-01-01

    Many scientists, journals and funders are concerned about the low reproducibility of many scientific findings. One approach that may serve to improve the reliability and robustness of research is open science. Here I argue that the process of pre-registering study protocols, sharing study materials and data, and posting preprints of manuscripts may serve to improve quality control procedures at every stage of the research pipeline, and in turn improve the reproducibility of published work. PMID:27350794

  16. Contextual sensitivity in scientific reproducibility

    PubMed Central

    Van Bavel, Jay J.; Mende-Siedlecki, Peter; Brady, William J.; Reinero, Diego A.

    2016-01-01

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher’s degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed “hidden moderators”) between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility. PMID:27217556

  17. Towards Reproducibility in Computational Hydrology

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher; Wagener, Thorsten; Freer, Jim; Han, Dawei

    2016-04-01

    The ability to reproduce published scientific findings is a foundational principle of scientific research. Independent observation helps to verify the legitimacy of individual findings; build upon sound observations so that we can evolve hypotheses (and models) of how catchments function; and move them from specific circumstances to more general theory. The rise of computational research has brought increased focus on the issue of reproducibility across the broader scientific literature. This is because publications based on computational research typically do not contain sufficient information to enable the results to be reproduced, and therefore verified. Given the rise of computational analysis in hydrology over the past 30 years, to what extent is reproducibility, or a lack thereof, a problem in hydrology? Whilst much hydrological code is accessible, the actual code and workflow that produced and therefore documents the provenance of published scientific findings, is rarely available. We argue that in order to advance and make more robust the process of hypothesis testing and knowledge creation within the computational hydrological community, we need to build on from existing open data initiatives and adopt common standards and infrastructures to: first make code re-useable and easy to find through consistent use of metadata; second, publish well documented workflows that combine re-useable code together with data to enable published scientific findings to be reproduced; finally, use unique persistent identifiers (e.g. DOIs) to reference re-useable and reproducible code, thereby clearly showing the provenance of published scientific findings. Whilst extra effort is require to make work reproducible, there are benefits to both the individual and the broader community in doing so, which will improve the credibility of the science in the face of the need for societies to adapt to changing hydrological environments.

  18. Rotary head type reproducing apparatus

    DOEpatents

    Takayama, Nobutoshi; Edakubo, Hiroo; Kozuki, Susumu; Takei, Masahiro; Nagasawa, Kenichi

    1986-01-01

    In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

  19. Reproducible Bioinformatics Research for Biologists

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter describes the current Big Data problem in Bioinformatics and the resulting issues with performing reproducible computational research. The core of the chapter provides guidelines and summaries of current tools/techniques that a noncomputational researcher would need to learn to pe...

  20. Reproducible research in computational science.

    PubMed

    Peng, Roger D

    2011-12-02

    Computational science has led to exciting new developments, but the nature of the work has exposed limitations in our ability to evaluate published findings. Reproducibility has the potential to serve as a minimum standard for judging scientific claims when full independent replication of a study is not possible.

  1. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  2. Reliability and reproducibility of Kienbock's disease staging.

    PubMed

    Goeminne, S; Degreef, I; De Smet, L

    2010-09-01

    We evaluated the interobserver reliability and intraobserver reproducibility of the Lichtman et al. classification for Kienböck's disease by getting four observers with different experience to look at 70 sets of wrist radiographs at different points in time. These observers staged each set of radiographs. Paired comparisons of the observations identified an agreement in 63% of cases and a mean weighted kappa coefficient of 0.64 confirming interobserver reliability. The stage of the involved lunate was reproduced in 78% of the observations with a mean weighted kappa coefficient of 0.81 showing intraobserver reproducibility. This classification for Kienböck's disease has good reliability and reproducibility.

  3. Quantifying reproducibility in computational biology: the case of the tuberculosis drugome.

    PubMed

    Garijo, Daniel; Kinnings, Sarah; Xie, Li; Xie, Lei; Zhang, Yinliang; Bourne, Philip E; Gil, Yolanda

    2013-01-01

    How easy is it to reproduce the results found in a typical computational biology paper? Either through experience or intuition the reader will already know that the answer is with difficulty or not at all. In this paper we attempt to quantify this difficulty by reproducing a previously published paper for different classes of users (ranging from users with little expertise to domain experts) and suggest ways in which the situation might be improved. Quantification is achieved by estimating the time required to reproduce each of the steps in the method described in the original paper and make them part of an explicit workflow that reproduces the original results. Reproducing the method took several months of effort, and required using new versions and new software that posed challenges to reconstructing and validating the results. The quantification leads to "reproducibility maps" that reveal that novice researchers would only be able to reproduce a few of the steps in the method, and that only expert researchers with advance knowledge of the domain would be able to reproduce the method in its entirety. The workflow itself is published as an online resource together with supporting software and data. The paper concludes with a brief discussion of the complexities of requiring reproducibility in terms of cost versus benefit, and a desiderata with our observations and guidelines for improving reproducibility. This has implications not only in reproducing the work of others from published papers, but reproducing work from one's own laboratory.

  4. Highly reproducible SERS arrays directly written by inkjet printing

    NASA Astrophysics Data System (ADS)

    Yang, Qiang; Deng, Mengmeng; Li, Huizeng; Li, Mingzhu; Zhang, Cong; Shen, Weizhi; Li, Yanan; Guo, Dan; Song, Yanlin

    2014-12-01

    SERS arrays with uniform gold nanoparticle distribution were fabricated by direct-writing with an inkjet printing method. Quantitative analysis based on Raman detection was achieved with a small standard statistical deviation of less than 4% for the reproducibility and less than 5% for the long-term stability for 12 weeks.SERS arrays with uniform gold nanoparticle distribution were fabricated by direct-writing with an inkjet printing method. Quantitative analysis based on Raman detection was achieved with a small standard statistical deviation of less than 4% for the reproducibility and less than 5% for the long-term stability for 12 weeks. Electronic supplementary information (ESI) available: Additional information on the experimental details, gold nanoparticle characterization, and theoretical calculation for the diameters of contact area of droplets on substrates with different contact angles. See DOI: 10.1039/c4nr04656k

  5. Explorations in statistics: statistical facets of reproducibility.

    PubMed

    Curran-Everett, Douglas

    2016-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eleventh installment of Explorations in Statistics explores statistical facets of reproducibility. If we obtain an experimental result that is scientifically meaningful and statistically unusual, we would like to know that our result reflects a general biological phenomenon that another researcher could reproduce if (s)he repeated our experiment. But more often than not, we may learn this researcher cannot replicate our result. The National Institutes of Health and the Federation of American Societies for Experimental Biology have created training modules and outlined strategies to help improve the reproducibility of research. These particular approaches are necessary, but they are not sufficient. The principles of hypothesis testing and estimation are inherent to the notion of reproducibility in science. If we want to improve the reproducibility of our research, then we need to rethink how we apply fundamental concepts of statistics to our science.

  6. Language-Agnostic Reproducible Data Analysis Using Literate Programming.

    PubMed

    Vassilev, Boris; Louhimo, Riku; Ikonen, Elina; Hautaniemi, Sampsa

    2016-01-01

    A modern biomedical research project can easily contain hundreds of analysis steps and lack of reproducibility of the analyses has been recognized as a severe issue. While thorough documentation enables reproducibility, the number of analysis programs used can be so large that in reality reproducibility cannot be easily achieved. Literate programming is an approach to present computer programs to human readers. The code is rearranged to follow the logic of the program, and to explain that logic in a natural language. The code executed by the computer is extracted from the literate source code. As such, literate programming is an ideal formalism for systematizing analysis steps in biomedical research. We have developed the reproducible computing tool Lir (literate, reproducible computing) that allows a tool-agnostic approach to biomedical data analysis. We demonstrate the utility of Lir by applying it to a case study. Our aim was to investigate the role of endosomal trafficking regulators to the progression of breast cancer. In this analysis, a variety of tools were combined to interpret the available data: a relational database, standard command-line tools, and a statistical computing environment. The analysis revealed that the lipid transport related genes LAPTM4B and NDRG1 are coamplified in breast cancer patients, and identified genes potentially cooperating with LAPTM4B in breast cancer progression. Our case study demonstrates that with Lir, an array of tools can be combined in the same data analysis to improve efficiency, reproducibility, and ease of understanding. Lir is an open-source software available at github.com/borisvassilev/lir.

  7. Language-Agnostic Reproducible Data Analysis Using Literate Programming

    PubMed Central

    Vassilev, Boris; Louhimo, Riku; Ikonen, Elina; Hautaniemi, Sampsa

    2016-01-01

    A modern biomedical research project can easily contain hundreds of analysis steps and lack of reproducibility of the analyses has been recognized as a severe issue. While thorough documentation enables reproducibility, the number of analysis programs used can be so large that in reality reproducibility cannot be easily achieved. Literate programming is an approach to present computer programs to human readers. The code is rearranged to follow the logic of the program, and to explain that logic in a natural language. The code executed by the computer is extracted from the literate source code. As such, literate programming is an ideal formalism for systematizing analysis steps in biomedical research. We have developed the reproducible computing tool Lir (literate, reproducible computing) that allows a tool-agnostic approach to biomedical data analysis. We demonstrate the utility of Lir by applying it to a case study. Our aim was to investigate the role of endosomal trafficking regulators to the progression of breast cancer. In this analysis, a variety of tools were combined to interpret the available data: a relational database, standard command-line tools, and a statistical computing environment. The analysis revealed that the lipid transport related genes LAPTM4B and NDRG1 are coamplified in breast cancer patients, and identified genes potentially cooperating with LAPTM4B in breast cancer progression. Our case study demonstrates that with Lir, an array of tools can be combined in the same data analysis to improve efficiency, reproducibility, and ease of understanding. Lir is an open-source software available at github.com/borisvassilev/lir. PMID:27711123

  8. The Economics of Reproducibility in Preclinical Research.

    PubMed

    Freedman, Leonard P; Cockburn, Iain M; Simcoe, Timothy S

    2015-06-01

    Low reproducibility rates within life science research undermine cumulative knowledge production and contribute to both delays and costs of therapeutic drug development. An analysis of past studies indicates that the cumulative (total) prevalence of irreproducible preclinical research exceeds 50%, resulting in approximately US$28,000,000,000 (US$28B)/year spent on preclinical research that is not reproducible-in the United States alone. We outline a framework for solutions and a plan for long-term improvements in reproducibility rates that will help to accelerate the discovery of life-saving therapies and cures.

  9. In Spite of Indeterminacy Many Common Factor Score Estimates Yield an Identical Reproduced Covariance Matrix

    ERIC Educational Resources Information Center

    Beauducel, Andre

    2007-01-01

    It was investigated whether commonly used factor score estimates lead to the same reproduced covariance matrix of observed variables. This was achieved by means of Schonemann and Steiger's (1976) regression component analysis, since it is possible to compute the reproduced covariance matrices of the regression components corresponding to different…

  10. Reproducible research in vadose zone sciences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A significant portion of present-day soil and Earth science research is computational, involving complex data analysis pipelines, advanced mathematical and statistical models, and sophisticated computer codes. Opportunities for scientific progress are greatly diminished if reproducing and building o...

  11. Planar heterojunction perovskite solar cells with superior reproducibility

    PubMed Central

    Jeon, Ye-Jin; Lee, Sehyun; Kang, Rira; Kim, Jueng-Eun; Yeo, Jun-Seok; Lee, Seung-Hoon; Kim, Seok-Soon; Yun, Jin-Mun; Kim, Dong-Yu

    2014-01-01

    Perovskite solar cells (PeSCs) have been considered one of the competitive next generation power sources. To date, light-to-electric conversion efficiencies have rapidly increased to over 10%, and further improvements are expected. However, the poor device reproducibility of PeSCs ascribed to their inhomogeneously covered film morphology has hindered their practical application. Here, we demonstrate high-performance PeSCs with superior reproducibility by introducing small amounts of N-cyclohexyl-2-pyrrolidone (CHP) as a morphology controller into N,N-dimethylformamide (DMF). As a result, highly homogeneous film morphology, similar to that achieved by vacuum-deposition methods, as well as a high PCE of 10% and an extremely small performance deviation within 0.14% were achieved. This study represents a method for realizing efficient and reproducible planar heterojunction (PHJ) PeSCs through morphology control, taking a major step forward in the low-cost and rapid production of PeSCs by solving one of the biggest problems of PHJ perovskite photovoltaic technology through a facile method. PMID:25377945

  12. Planar heterojunction perovskite solar cells with superior reproducibility

    NASA Astrophysics Data System (ADS)

    Jeon, Ye-Jin; Lee, Sehyun; Kang, Rira; Kim, Jueng-Eun; Yeo, Jun-Seok; Lee, Seung-Hoon; Kim, Seok-Soon; Yun, Jin-Mun; Kim, Dong-Yu

    2014-11-01

    Perovskite solar cells (PeSCs) have been considered one of the competitive next generation power sources. To date, light-to-electric conversion efficiencies have rapidly increased to over 10%, and further improvements are expected. However, the poor device reproducibility of PeSCs ascribed to their inhomogeneously covered film morphology has hindered their practical application. Here, we demonstrate high-performance PeSCs with superior reproducibility by introducing small amounts of N-cyclohexyl-2-pyrrolidone (CHP) as a morphology controller into N,N-dimethylformamide (DMF). As a result, highly homogeneous film morphology, similar to that achieved by vacuum-deposition methods, as well as a high PCE of 10% and an extremely small performance deviation within 0.14% were achieved. This study represents a method for realizing efficient and reproducible planar heterojunction (PHJ) PeSCs through morphology control, taking a major step forward in the low-cost and rapid production of PeSCs by solving one of the biggest problems of PHJ perovskite photovoltaic technology through a facile method.

  13. Planar heterojunction perovskite solar cells with superior reproducibility.

    PubMed

    Jeon, Ye-Jin; Lee, Sehyun; Kang, Rira; Kim, Jueng-Eun; Yeo, Jun-Seok; Lee, Seung-Hoon; Kim, Seok-Soon; Yun, Jin-Mun; Kim, Dong-Yu

    2014-11-07

    Perovskite solar cells (PeSCs) have been considered one of the competitive next generation power sources. To date, light-to-electric conversion efficiencies have rapidly increased to over 10%, and further improvements are expected. However, the poor device reproducibility of PeSCs ascribed to their inhomogeneously covered film morphology has hindered their practical application. Here, we demonstrate high-performance PeSCs with superior reproducibility by introducing small amounts of N-cyclohexyl-2-pyrrolidone (CHP) as a morphology controller into N,N-dimethylformamide (DMF). As a result, highly homogeneous film morphology, similar to that achieved by vacuum-deposition methods, as well as a high PCE of 10% and an extremely small performance deviation within 0.14% were achieved. This study represents a method for realizing efficient and reproducible planar heterojunction (PHJ) PeSCs through morphology control, taking a major step forward in the low-cost and rapid production of PeSCs by solving one of the biggest problems of PHJ perovskite photovoltaic technology through a facile method.

  14. Assessing the reproducibility of discriminant function analyses

    PubMed Central

    Andrew, Rose L.; Albert, Arianne Y.K.; Renaut, Sebastien; Rennison, Diana J.; Bock, Dan G.

    2015-01-01

    Data are the foundation of empirical research, yet all too often the datasets underlying published papers are unavailable, incorrect, or poorly curated. This is a serious issue, because future researchers are then unable to validate published results or reuse data to explore new ideas and hypotheses. Even if data files are securely stored and accessible, they must also be accompanied by accurate labels and identifiers. To assess how often problems with metadata or data curation affect the reproducibility of published results, we attempted to reproduce Discriminant Function Analyses (DFAs) from the field of organismal biology. DFA is a commonly used statistical analysis that has changed little since its inception almost eight decades ago, and therefore provides an opportunity to test reproducibility among datasets of varying ages. Out of 100 papers we initially surveyed, fourteen were excluded because they did not present the common types of quantitative result from their DFA or gave insufficient details of their DFA. Of the remaining 86 datasets, there were 15 cases for which we were unable to confidently relate the dataset we received to the one used in the published analysis. The reasons ranged from incomprehensible or absent variable labels, the DFA being performed on an unspecified subset of the data, or the dataset we received being incomplete. We focused on reproducing three common summary statistics from DFAs: the percent variance explained, the percentage correctly assigned and the largest discriminant function coefficient. The reproducibility of the first two was fairly high (20 of 26, and 44 of 60 datasets, respectively), whereas our success rate with the discriminant function coefficients was lower (15 of 26 datasets). When considering all three summary statistics, we were able to completely reproduce 46 (65%) of 71 datasets. While our results show that a majority of studies are reproducible, they highlight the fact that many studies still are not the

  15. Pressure Stabilizer for Reproducible Picoinjection in Droplet Microfluidic Systems

    PubMed Central

    Rhee, Minsoung; Light, Yooli K.; Yilmaz, Suzan; Adams, Paul D.; Saxena, Deepak

    2014-01-01

    Picoinjection is a promising technique to add reagents into pre-formed emulsion droplets on chip; however, it is sensitive to pressure fluctuation, making stable operation of the picoinjector challenging. We present a chip architecture using a simple pressure stabilizer for consistent and highly reproducible picoinjection in multi-step biochemical assays with droplets. Incorporation of the stabilizer immediately upstream of a picoinjector or a combination of injectors greatly reduces pressure fluctuations enabling reproducible and effective picoinjection in systems where the pressure varies actively during operation. We demonstrate the effectiveness of the pressure stabilizer for an integrated platform for on-demand encapsulation of bacterial cells followed by picoinjection of reagents for lysing the encapsulated cells. The pressure stabilizer was also used for picoinjection of multiple displacement amplification (MDA) reagents to achieve genomic DNA amplification of lysed bacterial cells. PMID:25270338

  16. Pressure stabilizer for reproducible picoinjection in droplet microfluidic systems.

    PubMed

    Rhee, Minsoung; Light, Yooli K; Yilmaz, Suzan; Adams, Paul D; Saxena, Deepak; Meagher, Robert J; Singh, Anup K

    2014-12-07

    Picoinjection is a promising technique to add reagents into pre-formed emulsion droplets on chip however, it is sensitive to pressure fluctuation, making stable operation of the picoinjector challenging. We present a chip architecture using a simple pressure stabilizer for consistent and highly reproducible picoinjection in multi-step biochemical assays with droplets. Incorporation of the stabilizer immediately upstream of a picoinjector or a combination of injectors greatly reduces pressure fluctuations enabling reproducible and effective picoinjection in systems where the pressure varies actively during operation. We demonstrate the effectiveness of the pressure stabilizer for an integrated platform for on-demand encapsulation of bacterial cells followed by picoinjection of reagents for lysing the encapsulated cells. The pressure stabilizer was also used for picoinjection of multiple displacement amplification (MDA) reagents to achieve genomic DNA amplification of lysed bacterial cells.

  17. Relevance relations for the concept of reproducibility

    PubMed Central

    Atmanspacher, H.; Bezzola Lambert, L.; Folkers, G.; Schubiger, P. A.

    2014-01-01

    The concept of reproducibility is widely considered a cornerstone of scientific methodology. However, recent problems with the reproducibility of empirical results in large-scale systems and in biomedical research have cast doubts on its universal and rigid applicability beyond the so-called basic sciences. Reproducibility is a particularly difficult issue in interdisciplinary work where the results to be reproduced typically refer to different levels of description of the system considered. In such cases, it is mandatory to distinguish between more and less relevant features, attributes or observables of the system, depending on the level at which they are described. For this reason, we propose a scheme for a general ‘relation of relevance’ between the level of complexity at which a system is considered and the granularity of its description. This relation implies relevance criteria for particular selected aspects of a system and its description, which can be operationally implemented by an interlevel relation called ‘contextual emergence’. It yields a formally sound and empirically applicable procedure to translate between descriptive levels and thus construct level-specific criteria for reproducibility in an overall consistent fashion. Relevance relations merged with contextual emergence challenge the old idea of one fundamental ontology from which everything else derives. At the same time, our proposal is specific enough to resist the backlash into a relativist patchwork of unconnected model fragments. PMID:24554574

  18. Optical thin film devices

    NASA Astrophysics Data System (ADS)

    Mao, Shuzheng

    1991-11-01

    Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when

  19. On the reproducibility of SSNTD track counting efficiency

    NASA Astrophysics Data System (ADS)

    Guedes O, S.; Hadler N, J. C.; Iunes, P. J.; Paulo, S. R.; Tello S, C. A.

    1998-12-01

    In this work, the influence of track density and chemical etching on the reproducibility of the track counting efficiency, ɛ0, in solid state nuclear track detectors (SSNTDs) is studied. This was performed by means of the analysis of CR-39 sheets that were attached to a thin film of natural uranium. Maintaining the chemical etching parameters constant and varying the exposition time, ɛ0 is observed to be constant for track densities varying between values approximately equal to the track background and those corresponding to the track overlapping limit, where track counting becomes difficult ( ˜10 5 cm-2 at our conditions). Otherwise, keeping constant the exposition time and varying the etching temperature, a variation in ɛ0 is found if a usual track counting criterion is employed. However, such a variation vanishes statistically when a more rigorous criterion is adopted.

  20. Reproducibility of graph metrics in FMRI networks.

    PubMed

    Telesford, Qawi K; Morgan, Ashley R; Hayasaka, Satoru; Simpson, Sean L; Barret, William; Kraft, Robert A; Mozolic, Jennifer L; Laurienti, Paul J

    2010-01-01

    The reliability of graph metrics calculated in network analysis is essential to the interpretation of complex network organization. These graph metrics are used to deduce the small-world properties in networks. In this study, we investigated the test-retest reliability of graph metrics from functional magnetic resonance imaging data collected for two runs in 45 healthy older adults. Graph metrics were calculated on data for both runs and compared using intraclass correlation coefficient (ICC) statistics and Bland-Altman (BA) plots. ICC scores describe the level of absolute agreement between two measurements and provide a measure of reproducibility. For mean graph metrics, ICC scores were high for clustering coefficient (ICC = 0.86), global efficiency (ICC = 0.83), path length (ICC = 0.79), and local efficiency (ICC = 0.75); the ICC score for degree was found to be low (ICC = 0.29). ICC scores were also used to generate reproducibility maps in brain space to test voxel-wise reproducibility for unsmoothed and smoothed data. Reproducibility was uniform across the brain for global efficiency and path length, but was only high in network hubs for clustering coefficient, local efficiency, and degree. BA plots were used to test the measurement repeatability of all graph metrics. All graph metrics fell within the limits for repeatability. Together, these results suggest that with exception of degree, mean graph metrics are reproducible and suitable for clinical studies. Further exploration is warranted to better understand reproducibility across the brain on a voxel-wise basis.

  1. Making Early Modern Medicine: Reproducing Swedish Bitters.

    PubMed

    Ahnfelt, Nils-Otto; Fors, Hjalmar

    2016-05-01

    Historians of science and medicine have rarely applied themselves to reproducing the experiments and practices of medicine and pharmacy. This paper delineates our efforts to reproduce "Swedish Bitters," an early modern composite medicine in wide European use from the 1730s to the present. In its original formulation, it was made from seven medicinal simples: aloe, rhubarb, saffron, myrrh, gentian, zedoary and agarikon. These were mixed in alcohol together with some theriac, a composite medicine of classical origin. The paper delineates the compositional history of Swedish Bitters and the medical rationale underlying its composition. It also describes how we go about to reproduce the medicine in a laboratory using early modern pharmaceutical methods, and analyse it using contemporary methods of pharmaceutical chemistry. Our aim is twofold: first, to show how reproducing medicines may provide a path towards a deeper understanding of the role of sensual and practical knowledge in the wider context of early modern medical culture; and second, how it may yield interesting results from the point of view of contemporary pharmaceutical science.

  2. Natural Disasters: Earth Science Readings. Reproducibles.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    Natural Disasters is a reproducible teacher book that explains what scientists believe to be the causes of a variety of natural disasters and suggests steps that teachers and students can take to be better prepared in the event of a natural disaster. It contains both student and teacher sections. Teacher sections include vocabulary, an answer key,…

  3. Europe Today: An Atlas of Reproducible Pages.

    ERIC Educational Resources Information Center

    World Eagle, Inc., Wellesley, MA.

    Illustrative black and white maps, tables, and graphs designed for clear reproducibility depict Europe's size, population, resources, commodities, trade, cities, schooling, jobs, energy, industry, demographic statistics, food, and agriculture. Also included are 33 United States Department of State individual country maps. This volume is intended…

  4. ITK: enabling reproducible research and open science

    PubMed Central

    McCormick, Matthew; Liu, Xiaoxiao; Jomier, Julien; Marion, Charles; Ibanez, Luis

    2014-01-01

    Reproducibility verification is essential to the practice of the scientific method. Researchers report their findings, which are strengthened as other independent groups in the scientific community share similar outcomes. In the many scientific fields where software has become a fundamental tool for capturing and analyzing data, this requirement of reproducibility implies that reliable and comprehensive software platforms and tools should be made available to the scientific community. The tools will empower them and the public to verify, through practice, the reproducibility of observations that are reported in the scientific literature. Medical image analysis is one of the fields in which the use of computational resources, both software and hardware, are an essential platform for performing experimental work. In this arena, the introduction of the Insight Toolkit (ITK) in 1999 has transformed the field and facilitates its progress by accelerating the rate at which algorithmic implementations are developed, tested, disseminated and improved. By building on the efficiency and quality of open source methodologies, ITK has provided the medical image community with an effective platform on which to build a daily workflow that incorporates the true scientific practices of reproducibility verification. This article describes the multiple tools, methodologies, and practices that the ITK community has adopted, refined, and followed during the past decade, in order to become one of the research communities with the most modern reproducibility verification infrastructure. For example, 207 contributors have created over 2400 unit tests that provide over 84% code line test coverage. The Insight Journal, an open publication journal associated with the toolkit, has seen over 360,000 publication downloads. The median normalized closeness centrality, a measure of knowledge flow, resulting from the distributed peer code review system was high, 0.46. PMID:24600387

  5. Thin silicon solar cells

    SciTech Connect

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Cotter, J.; Hughes-Lampros, T.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M.

    1992-12-01

    The silicon-film design achieves high performance by using a dun silicon layer and incorporating light trapping. Optimally designed thin crystalline solar cells (<50 microns thick) have performance advantages over conventional thick devices. The high-performance silicon-film design employs a metallurgical barrier between the low-cost substrate and the thin silicon layer. Light trapping properties of silicon-film on ceramic solar cells are presented and analyzed. Recent advances in process development are described here.

  6. Robust tissue classification for reproducible wound assessment in telemedicine environments

    NASA Astrophysics Data System (ADS)

    Wannous, Hazem; Treuillet, Sylvie; Lucas, Yves

    2010-04-01

    In telemedicine environments, a standardized and reproducible assessment of wounds, using a simple free-handled digital camera, is an essential requirement. However, to ensure robust tissue classification, particular attention must be paid to the complete design of the color processing chain. We introduce the key steps including color correction, merging of expert labeling, and segmentation-driven classification based on support vector machines. The tool thus developed ensures stability under lighting condition, viewpoint, and camera changes, to achieve accurate and robust classification of skin tissues. Clinical tests demonstrate that such an advanced tool, which forms part of a complete 3-D and color wound assessment system, significantly improves the monitoring of the healing process. It achieves an overlap score of 79.3 against 69.1% for a single expert, after mapping on the medical reference developed from the image labeling by a college of experts.

  7. Reproducibility of 3D chromatin configuration reconstructions

    PubMed Central

    Segal, Mark R.; Xiong, Hao; Capurso, Daniel; Vazquez, Mariel; Arsuaga, Javier

    2014-01-01

    It is widely recognized that the three-dimensional (3D) architecture of eukaryotic chromatin plays an important role in processes such as gene regulation and cancer-driving gene fusions. Observing or inferring this 3D structure at even modest resolutions had been problematic, since genomes are highly condensed and traditional assays are coarse. However, recently devised high-throughput molecular techniques have changed this situation. Notably, the development of a suite of chromatin conformation capture (CCC) assays has enabled elicitation of contacts—spatially close chromosomal loci—which have provided insights into chromatin architecture. Most analysis of CCC data has focused on the contact level, with less effort directed toward obtaining 3D reconstructions and evaluating the accuracy and reproducibility thereof. While questions of accuracy must be addressed experimentally, questions of reproducibility can be addressed statistically—the purpose of this paper. We use a constrained optimization technique to reconstruct chromatin configurations for a number of closely related yeast datasets and assess reproducibility using four metrics that measure the distance between 3D configurations. The first of these, Procrustes fitting, measures configuration closeness after applying reflection, rotation, translation, and scaling-based alignment of the structures. The others base comparisons on the within-configuration inter-point distance matrix. Inferential results for these metrics rely on suitable permutation approaches. Results indicate that distance matrix-based approaches are preferable to Procrustes analysis, not because of the metrics per se but rather on account of the ability to customize permutation schemes to handle within-chromosome contiguity. It has recently been emphasized that the use of constrained optimization approaches to 3D architecture reconstruction are prone to being trapped in local minima. Our methods of reproducibility assessment provide a

  8. Data Identifiers and Citations Enable Reproducible Science

    NASA Astrophysics Data System (ADS)

    Tilmes, C.

    2011-12-01

    Modern science often involves data processing with tremendous volumes of data. Keeping track of that data has been a growing challenge for data center. Researchers who access and use that data don't always reference and cite their data sources adequately for consumers of their research to follow their methodology or reproduce their analyses or experiments. Recent research has led to recommendations for good identifiers and citations that can help address this problem. This paper will describe some of the best practices in data identifiers, reference and citation. Using a simplified example scenario based on a long term remote sensing satellite mission, it will explore issues in identifying dynamic data sets and the importance of good data citations for reproducibility. It will describe the difference between granule and collection level identifiers, using UUIDs and DOIs to illustrate some recommendations for developing identifiers and assigning them during data processing. As data processors create data products, the provenance of the input products and precise steps that led to their creation are recorded and published for users of the data to see. As researchers access the data from an archive, they can use the provenance to help understand the genesis of the data, which could have effects on their usage of the data. By citing the data on publishing their research, others can retrieve the precise data used in their research and reproduce the analyses and experiments to confirm the results. Describing the experiment to a sufficient extent to reproduce the research enforces a formal approach that lends credibility to the results, and ultimately, to the policies of decision makers depending on that research.

  9. Tissue Doppler imaging reproducibility during exercise.

    PubMed

    Bougault, V; Nottin, S; Noltin, S; Doucende, G; Obert, P

    2008-05-01

    Tissue Doppler imaging (TDI) is an echocardiographic technique used during exercising to improve the accuracy of a cardiovascular diagnostic. The validity of TDI requires its reproducibility, which has never been challenged during moderate to maximal intensity exercising. The present study was specifically designed to assess the transmitral Doppler and pulsed TDI reproducibility in 19 healthy men, who had undergone two identical semi-supine maximal exercise tests on a cycle ergometer. Systolic (S') and diastolic (E') tissue velocities at the septal and lateral walls as well as early transmitral velocities (E) were assessed during exercise up to maximal effort. The data were compared between the two tests at 40 %, 60 %, 80 % and 100 % of maximal aerobic power. Despite upper body movements and hyperventilation, good quality echocardiographic images were obtained in each case. Regardless of exercise intensity, no differences were noticed between the two tests for all measurements. The variation coefficients for Doppler variables ranged from 3 % to 9 % over the transition from rest to maximal exercise. The random measurement error was, on average, 5.8 cm/s for E' and 4.4 cm/s for S'. Overall, the reproducibility of TDI was acceptable. Tissue Doppler imaging can be used to accurately evaluate LV diastolic and/or systolic function for this range of exercise intensity.

  10. A Framework for Reproducible Latent Fingerprint Enhancements.

    PubMed

    Carasso, Alfred S

    2014-01-01

    Photoshop processing of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology.

  11. Tools and techniques for computational reproducibility.

    PubMed

    Piccolo, Stephen R; Frampton, Michael B

    2016-07-11

    When reporting research findings, scientists document the steps they followed so that others can verify and build upon the research. When those steps have been described in sufficient detail that others can retrace the steps and obtain similar results, the research is said to be reproducible. Computers play a vital role in many research disciplines and present both opportunities and challenges for reproducibility. Computers can be programmed to execute analysis tasks, and those programs can be repeated and shared with others. The deterministic nature of most computer programs means that the same analysis tasks, applied to the same data, will often produce the same outputs. However, in practice, computational findings often cannot be reproduced because of complexities in how software is packaged, installed, and executed-and because of limitations associated with how scientists document analysis steps. Many tools and techniques are available to help overcome these challenges; here we describe seven such strategies. With a broad scientific audience in mind, we describe the strengths and limitations of each approach, as well as the circumstances under which each might be applied. No single strategy is sufficient for every scenario; thus we emphasize that it is often useful to combine approaches.

  12. Reproducibility and Validity of a Handheld Spirometer

    PubMed Central

    Barr, R Graham; Stemple, Kimberly J.; Mesia-Vela, Sonia; Basner, Robert C.; Derk, Susan; Henneberger, Paul; Milton, Donald K; Taveras, Brenda

    2013-01-01

    Background Handheld spirometers have several advantages over desktop spirometers but worries persist regarding their reproducibility and validity. We undertook an independent examination of an ultrasonic flow-sensing handheld spirometer. Methods Laboratory methods included reproducibility and validity testing using a waveform generator with standard American Thoracic Society (ATS) waveforms, in-line testing, calibration adaptor testing, and compression of the mouthpiece. Clinical testing involved repeated testing of 24 spirometry-naive volunteers and comparison to a volume-sensing dry rolling seal spirometer. Results The EasyOne Diagnostic spirometer exceeded standard thresholds of acceptability for ATS waveforms. In-line testing yielded valid results with relative differences (mean ± SD) between the EasyOne and the reference spirometer for the forced vital capacity (FVC) of 0.03±0.23 L and the forced expiratory volume in one second (FEV1) of −0.06±0.09 L. The calibration adaptor showed no appreciable problems, but extreme compression of the mouthpiece reduced measures. In clinical testing, coefficients of variation and limits of agreement were, respectively: 3.3% and 0.24 L for the FVC; 2.6% and 0.18 L for the FEV1; and 1.9% and 0.05 for the FEV1/FVC ratio. The EasyOne yielded lower values than the reference spirometry (FVC: −0.12 L; FEV1: −0.17 L; FEV1/FVC ratio: −0.02). Limits of agreement were within criteria for FVC but not for the FEV1, possibly due to a training effect. Conclusion The EasyOne spirometer yielded generally reproducible results that were generally valid compared to laboratory-based spirometry. The use of this handheld spirometer in clinical, occupational and research settings seems justified. PMID:18364054

  13. Queer nuclear families? Reproducing and transgressing heteronormativity.

    PubMed

    Folgerø, Tor

    2008-01-01

    During the past decade the public debate on gay and lesbian adoptive rights has been extensive in the Norwegian media. The debate illustrates how women and men planning to raise children in homosexual family constellations challenge prevailing cultural norms and existing concepts of kinship and family. The article discusses how lesbian mothers and gay fathers understand and redefine their own family practices. An essential point in this article is the fundamental ambiguity in these families' accounts of themselves-how they simultaneously transgress and reproduce heteronormative assumptions about childhood, fatherhood, motherhood, family and kinship.

  14. Towards reproducible, scalable lateral molecular electronic devices

    SciTech Connect

    Durkan, Colm Zhang, Qian

    2014-08-25

    An approach to reproducibly fabricate molecular electronic devices is presented. Lateral nanometer-scale gaps with high yield are formed in Au/Pd nanowires by a combination of electromigration and Joule-heating-induced thermomechanical stress. The resulting nanogap devices are used to measure the electrical properties of small numbers of two different molecular species with different end-groups, namely 1,4-butane dithiol and 1,5-diamino-2-methylpentane. Fluctuations in the current reveal that in the case of the dithiol molecule devices, individual molecules conduct intermittently, with the fluctuations becoming more pronounced at larger biases.

  15. Open and reproducible global land use classification

    NASA Astrophysics Data System (ADS)

    Nüst, Daniel; Václavík, Tomáš; Pross, Benjamin

    2015-04-01

    Researchers led by the Helmholtz Centre for Environmental research (UFZ) developed a new world map of land use systems based on over 30 diverse indicators (http://geoportal.glues.geo.tu-dresden.de/stories/landsystemarchetypes.html) of land use intensity, climate and environmental and socioeconomic factors. They identified twelve land system archetypes (LSA) using a data-driven classification algorithm (self-organizing maps) to assess global impacts of land use on the environment, and found unexpected similarities across global regions. We present how the algorithm behind this analysis can be published as an executable web process using 52°North WPS4R (https://wiki.52north.org/bin/view/Geostatistics/WPS4R) within the GLUES project (http://modul-a.nachhaltiges-landmanagement.de/en/scientific-coordination-glues/). WPS4R is an open source collaboration platform for researchers, analysts and software developers to publish R scripts (http://www.r-project.org/) as a geo-enabled OGC Web Processing Service (WPS) process. The interoperable interface to call the geoprocess allows both reproducibility of the analysis and integration of user data without knowledge about web services or classification algorithms. The open platform allows everybody to replicate the analysis in their own environments. The LSA WPS process has several input parameters, which can be changed via a simple web interface. The input parameters are used to configure both the WPS environment and the LSA algorithm itself. The encapsulation as a web process allows integration of non-public datasets, while at the same time the publication requires a well-defined documentation of the analysis. We demonstrate this platform specifically to domain scientists and show how reproducibility and open source publication of analyses can be enhanced. We also discuss future extensions of the reproducible land use classification, such as the possibility for users to enter their own areas of interest to the system and

  16. Thin film interference of colloidal thin films.

    PubMed

    Cong, Hailin; Cao, Weixiao

    2004-09-14

    A stairlike colloidal crystal thin film composed of poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) monodispersed colloids was fabricated on an inclined silicon substrate. Different bright colors were observed on the various parts of the film with different layers as white light irradiated perpendicularly on it. The relationship between the colors and layers of the film was investigated and discussed according to the principle of thin film interference. On the basis of the phenomenon of thin film interference, a one-layer colloidal film having uniform color was researched and it would display diverse colors before and after swollen by styrene (St). A circular stairlike colloidal film was achieved to mimic the colors of the peacock tail feather.

  17. Improved Reproducibility for Perovskite Solar Cells with 1 cm(2) Active Area by a Modified Two-Step Process.

    PubMed

    Shen, Heping; Wu, Yiliang; Peng, Jun; Duong, The; Fu, Xiao; Barugkin, Chog; White, Thomas P; Weber, Klaus; Catchpole, Kylie R

    2017-02-22

    With rapid progress in recent years, organohalide perovskite solar cells (PSC) are promising candidates for a new generation of highly efficient thin-film photovoltaic technologies, for which up-scaling is an essential step toward commercialization. In this work, we propose a modified two-step method to deposit the CH3NH3PbI3 (MAPbI3) perovskite film that improves the uniformity, photovoltaic performance, and repeatability of large-area perovskite solar cells. This method is based on the commonly used two-step method, with one additional process involving treating the perovskite film with concentrated methylammonium iodide (MAI) solution. This additional treatment is proved to be helpful for tailoring the residual PbI2 level to an optimal range that is favorable for both optical absorption and inhibition of recombination. Scanning electron microscopy and photoluminescence image analysis further reveal that, compared to the standard two-step and one-step methods, this method is very robust for achieving uniform and pinhole-free large-area films. This is validated by the photovoltaic performance of the prototype devices with an active area of 1 cm(2), where we achieved the champion efficiency of ∼14.5% and an average efficiency of ∼13.5%, with excellent reproducibility.

  18. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  19. Magnetochromatic thin-film microplates.

    PubMed

    He, Le; Janner, Michael; Lu, Qipeng; Wang, Mingsheng; Ma, Hua; Yin, Yadong

    2015-01-07

    A new type of magnetochromatic material is developed based on thin-film interference of microplates self-assembled from super-paramagnetic nanocrystals. Dynamic optical tuning can be achieved through orientational manipulation of free-standing super-paramagnetic thin-film microplates using external magnetic fields.

  20. Reproducibility and Transparency in Ocean-Climate Modeling

    NASA Astrophysics Data System (ADS)

    Hannah, N.; Adcroft, A.; Hallberg, R.; Griffies, S. M.

    2015-12-01

    Reproducibility is a cornerstone of the scientific method. Within geophysical modeling and simulation achieving reproducibility can be difficult, especially given the complexity of numerical codes, enormous and disparate data sets, and variety of supercomputing technology. We have made progress on this problem in the context of a large project - the development of new ocean and sea ice models, MOM6 and SIS2. Here we present useful techniques and experience.We use version control not only for code but the entire experiment working directory, including configuration (run-time parameters, component versions), input data and checksums on experiment output. This allows us to document when the solutions to experiments change, whether due to code updates or changes in input data. To avoid distributing large input datasets we provide the tools for generating these from the sources, rather than provide raw input data.Bugs can be a source of non-determinism and hence irreproducibility, e.g. reading from or branching on uninitialized memory. To expose these we routinely run system tests, using a memory debugger, multiple compilers and different machines. Additional confidence in the code comes from specialised tests, for example automated dimensional analysis and domain transformations. This has entailed adopting a code style where we deliberately restrict what a compiler can do when re-arranging mathematical expressions.In the spirit of open science, all development is in the public domain. This leads to a positive feedback, where increased transparency and reproducibility makes using the model easier for external collaborators, who in turn provide valuable contributions. To facilitate users installing and running the model we provide (version controlled) digital notebooks that illustrate and record analysis of output. This has the dual role of providing a gross, platform-independent, testing capability and a means to documents model output and analysis.

  1. Efficient and reproducible mammalian cell bioprocesses without probes and controllers?

    PubMed

    Tissot, Stéphanie; Oberbek, Agata; Reclari, Martino; Dreyer, Matthieu; Hacker, David L; Baldi, Lucia; Farhat, Mohamed; Wurm, Florian M

    2011-07-01

    Bioprocesses for recombinant protein production with mammalian cells are typically controlled for several physicochemical parameters including the pH and dissolved oxygen concentration (DO) of the culture medium. Here we studied whether these controls are necessary for efficient and reproducible bioprocesses in an orbitally shaken bioreactor (OSR). Mixing, gas transfer, and volumetric power consumption (P(V)) were determined in both a 5-L OSR and a 3-L stirred-tank bioreactor (STR). The two cultivation systems had a similar mixing intensity, but the STR had a lower volumetric mass transfer coefficient of oxygen (k(L)a) and a higher P(V) than the OSR. Recombinant CHO cell lines expressing either tumor necrosis factor receptor as an Fc fusion protein (TNFR:Fc) or an anti-RhesusD monoclonal antibody were cultivated in the two systems. The 5-L OSR was operated in an incubator shaker with 5% CO(2) in the gas environment but without pH and DO control whereas the STR was operated with or without pH and DO control. Higher cell densities and recombinant protein titers were obtained in the OSR as compared to both the controlled and the non-controlled STRs. To test the reproducibility of a bioprocess in a non-controlled OSR, the two CHO cell lines were each cultivated in parallel in six 5-L OSRs. Similar cell densities, cell viabilities, and recombinant protein titers along with similar pH and DO profiles were achieved in each group of replicates. Our study demonstrated that bioprocesses can be performed in OSRs without pH or DO control in a highly reproducible manner, at least at the scale of operation studied here.

  2. Paleomagnetic analysis of curved thrust belts reproduced by physical models

    NASA Astrophysics Data System (ADS)

    Costa, Elisabetta; Speranza, Fabio

    2003-12-01

    This paper presents a new methodology for studying the evolution of curved mountain belts by means of paleomagnetic analyses performed on analogue models. Eleven models were designed aimed at reproducing various tectonic settings in thin-skinned tectonics. Our models analyze in particular those features reported in the literature as possible causes for peculiar rotational patterns in the outermost as well as in the more internal fronts. In all the models the sedimentary cover was reproduced by frictional low-cohesion materials (sand and glass micro-beads), which detached either on frictional or on viscous layers. These latter were reproduced in the models by silicone. The sand forming the models has been previously mixed with magnetite-dominated powder. Before deformation, the models were magnetized by means of two permanent magnets generating within each model a quasi-linear magnetic field of intensity variable between 20 and 100 mT. After deformation, the models were cut into closely spaced vertical sections and sampled by means of 1×1-cm Plexiglas cylinders at several locations along curved fronts. Care was taken to collect paleomagnetic samples only within virtually undeformed thrust sheets, avoiding zones affected by pervasive shear. Afterwards, the natural remanent magnetization of these samples was measured, and alternating field demagnetization was used to isolate the principal components. The characteristic components of magnetization isolated were used to estimate the vertical-axis rotations occurring during model deformation. We find that indenters pushing into deforming belts from behind form non-rotational curved outer fronts. The more internal fronts show oroclinal-type rotations of a smaller magnitude than that expected for a perfect orocline. Lateral symmetrical obstacles in the foreland colliding with forward propagating belts produce non-rotational outer curved fronts as well, whereas in between and inside the obstacles a perfect orocline forms

  3. The flux qubit revisited to enhance coherence and reproducibility

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Gustavsson, Simon; Kamal, Archana; Birenbaum, Jeffrey; Sears, Adam P.; Hover, David; Gudmundsen, Ted J.; Rosenberg, Danna; Samach, Gabriel; Weber, S.; Yoder, Jonilyn L.; Orlando, Terry P.; Clarke, John; Kerman, Andrew J.; Oliver, William D.

    2016-11-01

    The scalable application of quantum information science will stand on reproducible and controllable high-coherence quantum bits (qubits). Here, we revisit the design and fabrication of the superconducting flux qubit, achieving a planar device with broad-frequency tunability, strong anharmonicity, high reproducibility and relaxation times in excess of 40 μs at its flux-insensitive point. Qubit relaxation times T1 across 22 qubits are consistently matched with a single model involving resonator loss, ohmic charge noise and 1/f-flux noise, a noise source previously considered primarily in the context of dephasing. We furthermore demonstrate that qubit dephasing at the flux-insensitive point is dominated by residual thermal-photons in the readout resonator. The resulting photon shot noise is mitigated using a dynamical decoupling protocol, resulting in T2~85 μs, approximately the 2T1 limit. In addition to realizing an improved flux qubit, our results uniquely identify photon shot noise as limiting T2 in contemporary qubits based on transverse qubit-resonator interaction.

  4. The flux qubit revisited to enhance coherence and reproducibility

    PubMed Central

    Yan, Fei; Gustavsson, Simon; Kamal, Archana; Birenbaum, Jeffrey; Sears, Adam P; Hover, David; Gudmundsen, Ted J.; Rosenberg, Danna; Samach, Gabriel; Weber, S; Yoder, Jonilyn L.; Orlando, Terry P.; Clarke, John; Kerman, Andrew J.; Oliver, William D.

    2016-01-01

    The scalable application of quantum information science will stand on reproducible and controllable high-coherence quantum bits (qubits). Here, we revisit the design and fabrication of the superconducting flux qubit, achieving a planar device with broad-frequency tunability, strong anharmonicity, high reproducibility and relaxation times in excess of 40 μs at its flux-insensitive point. Qubit relaxation times T1 across 22 qubits are consistently matched with a single model involving resonator loss, ohmic charge noise and 1/f-flux noise, a noise source previously considered primarily in the context of dephasing. We furthermore demonstrate that qubit dephasing at the flux-insensitive point is dominated by residual thermal-photons in the readout resonator. The resulting photon shot noise is mitigated using a dynamical decoupling protocol, resulting in T2≈85 μs, approximately the 2T1 limit. In addition to realizing an improved flux qubit, our results uniquely identify photon shot noise as limiting T2 in contemporary qubits based on transverse qubit–resonator interaction. PMID:27808092

  5. PSYCHOLOGY. Estimating the reproducibility of psychological science.

    PubMed

    2015-08-28

    Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams.

  6. Reproducibility and reusability of scientific software

    NASA Astrophysics Data System (ADS)

    Shamir, Lior

    2017-01-01

    Information science and technology has been becoming an integral part of astronomy research, and due to the consistent growth in the size and impact of astronomical databases, that trend is bound to continue. While software is a vital part information systems and data analysis processes, in many cases the importance of the software and the standards of reporting on the use of source code has not yet elevated in the scientific communication process to the same level as other parts of the research. The purpose of the discussion is to examine the role of software in the scientific communication process in the light of transparency, reproducibility, and reusability of the research, as well as discussing software in astronomy in comparison to other disciplines.

  7. Is Isolated Nocturnal Hypertension A Reproducible Phenotype?

    PubMed Central

    Goldsmith, Jeff; Muntner, Paul; Diaz, Keith M.; Reynolds, Kristi; Schwartz, Joseph E.; Shimbo, Daichi

    2016-01-01

    BACKGROUND Isolated nocturnal hypertension (INH), defined as nocturnal without daytime hypertension on ambulatory blood pressure (BP) monitoring (ABPM), has been observed to be associated with an increased risk of cardiovascular disease (CVD) events and mortality. The aim of this study was to determine the short-term reproducibility of INH. METHODS The Improving the Detection of Hypertension Study enrolled a community-based sample of adults (N = 282) in upper Manhattan without CVD, renal failure, or treated hypertension. Each participant completed two 24-hour ABPM recordings (ABPM1: first recording and ABPM2: second recording) with a mean ± SD time interval of 33±17 days between recordings. Daytime hypertension was defined as mean awake systolic/diastolic BP ≥ 135/85mm Hg; nocturnal hypertension as mean sleep systolic/diastolic BP ≥ 120/70mm Hg; INH as nocturnal without daytime hypertension; isolated daytime hypertension (IDH) as daytime without nocturnal hypertension; day and night hypertension (DNH) as daytime and nocturnal hypertension, and any ambulatory hypertension as having daytime and/or nocturnal hypertension. RESULTS On ABPM1, 26 (9.2%), 21 (7.4%), and 50 (17.7%) participants had INH, IDH, and DNH, respectively. On ABPM2, 24 (8.5%), 19 (6.7%), and 54 (19.1%) had INH, IDH, and DNH, respectively. The kappa statistics were 0.21 (95% confidence interval (CI) 0.04–0.38), 0.25 (95% CI 0.06–0.44), and 0.65 (95% CI 0.53–0.77) for INH, IDH, and DNH respectively; and 0.72 (95% CI 0.63–0.81) for having any ambulatory hypertension. CONCLUSIONS Our results suggest that INH and IDH are poorly reproducible phenotypes, and that ABPM should be primarily used to identify individuals with daytime hypertension and/or nocturnal hypertension. PMID:25904648

  8. Is Grannum grading of the placenta reproducible?

    NASA Astrophysics Data System (ADS)

    Moran, Mary; Ryan, John; Brennan, Patrick C.; Higgins, Mary; McAuliffe, Fionnuala M.

    2009-02-01

    Current ultrasound assessment of placental calcification relies on Grannum grading. The aim of this study was to assess if this method is reproducible by measuring inter- and intra-observer variation in grading placental images, under strictly controlled viewing conditions. Thirty placental images were acquired and digitally saved. Five experienced sonographers independently graded the images on two separate occasions. In order to eliminate any technological factors which could affect data reliability and consistency all observers reviewed images at the same time. To optimise viewing conditions ambient lighting was maintained between 25-40 lux, with monitors calibrated to the GSDF standard to ensure consistent brightness and contrast. Kappa (κ) analysis of the grades assigned was used to measure inter- and intra-observer reliability. Intra-observer agreement had a moderate mean κ-value of 0.55, with individual comparisons ranging from 0.30 to 0.86. Two images saved from the same patient, during the same scan, were each graded as I, II and III by the same observer. A mean κ-value of 0.30 (range from 0.13 to 0.55) indicated fair inter-observer agreement over the two occasions and only one image was graded consistently the same by all five observers. The study findings confirmed the lack of reproducibility associated with Grannum grading of the placenta despite optimal viewing conditions and highlight the need for new methods of assessing placental health in order to improve neonatal outcomes. Alternative methods for quantifying placental calcification such as a software based technique and 3D ultrasound assessment need to be explored.

  9. Datathons and Software to Promote Reproducible Research

    PubMed Central

    2016-01-01

    Background Datathons facilitate collaboration between clinicians, statisticians, and data scientists in order to answer important clinical questions. Previous datathons have resulted in numerous publications of interest to the critical care community and serve as a viable model for interdisciplinary collaboration. Objective We report on an open-source software called Chatto that was created by members of our group, in the context of the second international Critical Care Datathon, held in September 2015. Methods Datathon participants formed teams to discuss potential research questions and the methods required to address them. They were provided with the Chatto suite of tools to facilitate their teamwork. Each multidisciplinary team spent the next 2 days with clinicians working alongside data scientists to write code, extract and analyze data, and reformulate their queries in real time as needed. All projects were then presented on the last day of the datathon to a panel of judges that consisted of clinicians and scientists. Results Use of Chatto was particularly effective in the datathon setting, enabling teams to reduce the time spent configuring their research environments to just a few minutes—a process that would normally take hours to days. Chatto continued to serve as a useful research tool after the conclusion of the datathon. Conclusions This suite of tools fulfills two purposes: (1) facilitation of interdisciplinary teamwork through archiving and version control of datasets, analytical code, and team discussions, and (2) advancement of research reproducibility by functioning postpublication as an online environment in which independent investigators can rerun or modify analyses with relative ease. With the introduction of Chatto, we hope to solve a variety of challenges presented by collaborative data mining projects while improving research reproducibility. PMID:27558834

  10. Interlaboratory reproducibility of large-scale human protein-complex analysis by standardized AP-MS.

    PubMed

    Varjosalo, Markku; Sacco, Roberto; Stukalov, Alexey; van Drogen, Audrey; Planyavsky, Melanie; Hauri, Simon; Aebersold, Ruedi; Bennett, Keiryn L; Colinge, Jacques; Gstaiger, Matthias; Superti-Furga, Giulio

    2013-04-01

    The characterization of all protein complexes of human cells under defined physiological conditions using affinity purification-mass spectrometry (AP-MS) is a highly desirable step in the quest to understand the phenotypic effects of genomic information. However, such a challenging goal has not yet been achieved, as it requires reproducibility of the experimental workflow and high data consistency across different studies and laboratories. We systematically investigated the reproducibility of a standardized AP-MS workflow by performing a rigorous interlaboratory comparative analysis of the interactomes of 32 human kinases. We show that it is possible to achieve high interlaboratory reproducibility of this standardized workflow despite differences in mass spectrometry configurations and subtle sample preparation-related variations and that combination of independent data sets improves the approach sensitivity, resulting in even more-detailed networks. Our analysis demonstrates the feasibility of obtaining a high-quality map of the human protein interactome with a multilaboratory project.

  11. Reproducibility of neuroimaging analyses across operating systems.

    PubMed

    Glatard, Tristan; Lewis, Lindsay B; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed.

  12. REPRODUCIBLE AND SHAREABLE QUANTIFICATIONS OF PATHOGENICITY

    PubMed Central

    Manrai, Arjun K; Wang, Brice L; Patel, Chirag J; Kohane, Isaac S

    2016-01-01

    There are now hundreds of thousands of pathogenicity assertions that relate genetic variation to disease, but most of this clinically utilized variation has no accepted quantitative disease risk estimate. Recent disease-specific studies have used control sequence data to reclassify large amounts of prior pathogenic variation, but there is a critical need to scale up both the pace and feasibility of such pathogenicity reassessments across human disease. In this manuscript we develop a shareable computational framework to quantify pathogenicity assertions. We release a reproducible “digital notebook” that integrates executable code, text annotations, and mathematical expressions in a freely accessible statistical environment. We extend previous disease-specific pathogenicity assessments to over 6,000 diseases and 160,000 assertions in the ClinVar database. Investigators can use this platform to prioritize variants for reassessment and tailor genetic model parameters (such as prevalence and heterogeneity) to expose the uncertainty underlying pathogenicity-based risk assessments. Finally, we release a website that links users to pathogenic variation for a queried disease, supporting literature, and implied disease risk calculations subject to user-defined and disease-specific genetic risk models in order to facilitate variant reassessments. PMID:26776189

  13. TiO2 thin film based transparent flexible resistive switching random access memory

    NASA Astrophysics Data System (ADS)

    Pham, Kim Ngoc; Dung Hoang, Van; Tran, Cao Vinh; Thang Phan, Bach

    2016-03-01

    In our work we have fabricated TiO2 based resistive switching devices both on transparent substrates (ITO, IGZO/glass) and transparent flexible substrate (ITO/PET). All devices demonstrate the reproducibility of forming free bipolar resistive switching with high transparency in the visible light range (∼80% at the wavelength of 550 nm). Particularly, transparent and flexible device exhibits stable resistive switching performance at the initial state (flat) and even after bending state up to 500 times with curvature radius of 10% compared to flat state. The achieved characteristics of resistive switching of TiO2 thin films seem to be promising for transparent flexible random access memory.

  14. Specific and reproducible gas sensors utilizing gas-phase chemical reaction on organic transistors.

    PubMed

    Zang, Yaping; Zhang, Fengjiao; Huang, Dazhen; Di, Chong-an; Meng, Qing; Gao, Xike; Zhu, Daoben

    2014-05-01

    Utilizing a textbook reaction on the surface of an organic active channel, achieves sensitive detection of HCl, NH3 and NO2, with good selectivity, excellent reproducibility, and satisfactory stability. These results reveal gas-phase reaction assisted detection as a unique and promising approach to construct practical applicable gas sensors with typical organic transistors.

  15. Evaluation of Statistical Downscaling Skill at Reproducing Extreme Events

    NASA Astrophysics Data System (ADS)

    McGinnis, S. A.; Tye, M. R.; Nychka, D. W.; Mearns, L. O.

    2015-12-01

    Climate model outputs usually have much coarser spatial resolution than is needed by impacts models. Although higher resolution can be achieved using regional climate models for dynamical downscaling, further downscaling is often required. The final resolution gap is often closed with a combination of spatial interpolation and bias correction, which constitutes a form of statistical downscaling. We use this technique to downscale regional climate model data and evaluate its skill in reproducing extreme events. We downscale output from the North American Regional Climate Change Assessment Program (NARCCAP) dataset from its native 50-km spatial resolution to the 4-km resolution of University of Idaho's METDATA gridded surface meterological dataset, which derives from the PRISM and NLDAS-2 observational datasets. We operate on the major variables used in impacts analysis at a daily timescale: daily minimum and maximum temperature, precipitation, humidity, pressure, solar radiation, and winds. To interpolate the data, we use the patch recovery method from the Earth System Modeling Framework (ESMF) regridding package. We then bias correct the data using Kernel Density Distribution Mapping (KDDM), which has been shown to exhibit superior overall performance across multiple metrics. Finally, we evaluate the skill of this technique in reproducing extreme events by comparing raw and downscaled output with meterological station data in different bioclimatic regions according to the the skill scores defined by Perkins et al in 2013 for evaluation of AR4 climate models. We also investigate techniques for improving bias correction of values in the tails of the distributions. These techniques include binned kernel density estimation, logspline kernel density estimation, and transfer functions constructed by fitting the tails with a generalized pareto distribution.

  16. Reproducibility of pre-syncopal responses to repeated orthostatic challenge

    NASA Astrophysics Data System (ADS)

    Goswami, Nandu; Grasser, Erik; Roessler, Andreas; Hinghofer-Szalkay, Helmut

    Aims: To study individual patterns of hemodynamic adjustments in subjects reaching orthostatically induced presyncope and to observe whether these are reproducible across three runs. Procedures and methods: 10 healthy young males were subjected to extreme cardiovascular stress three times: Graded orthostatic stress (GOS), consisting of head-up tilt combined with lower body negative pressure, was used to achieve a pre-syncopal end-point. All test runs were separated by two week intervals. Orthostatic effects on cardiac and vascular function were continuously monitored and standing times noted. Results: Across the group, heart rate (HR) increased 112 percent, while mean arterial blood pressure dropped by 15 percent, pulse pressure by 36 percent, and stroke volume index by 51 percent on average from supine control to presyncope. Repetitions of the orthostatic protocols did not influence standing times of test persons from the 1st to the 3rd trial (15 plus minus 6 to 17 plus minus 7 min). Some individuals responded either with an increase in HR only, while the others with combined HR and total peripheral resistance increase, albeit shortly, and this individual specifc pattern was observed across the three runs of combined GOS. Conclusion: Strategies for maintaining blood pressure in response to central hypovolemia in subjects induced by orthostatic stress are different between subjects. However, the same individual specific hemodynamic mechanism is employed each time to maintain the blood pressure when reconfronted by this stress. Individual patterns of hemodynamic adjustments to orthostatic stress are highly reproducible when these subjects reach pre-syncope three times.

  17. Semiautomated, Reproducible Batch Processing of Soy

    NASA Technical Reports Server (NTRS)

    Thoerne, Mary; Byford, Ivan W.; Chastain, Jack W.; Swango, Beverly E.

    2005-01-01

    A computer-controlled apparatus processes batches of soybeans into one or more of a variety of food products, under conditions that can be chosen by the user and reproduced from batch to batch. Examples of products include soy milk, tofu, okara (an insoluble protein and fiber byproduct of soy milk), and whey. Most processing steps take place without intervention by the user. This apparatus was developed for use in research on processing of soy. It is also a prototype of other soy-processing apparatuses for research, industrial, and home use. Prior soy-processing equipment includes household devices that automatically produce soy milk but do not automatically produce tofu. The designs of prior soy-processing equipment require users to manually transfer intermediate solid soy products and to press them manually and, hence, under conditions that are not consistent from batch to batch. Prior designs do not afford choices of processing conditions: Users cannot use previously developed soy-processing equipment to investigate the effects of variations of techniques used to produce soy milk (e.g., cold grinding, hot grinding, and pre-cook blanching) and of such process parameters as cooking times and temperatures, grinding times, soaking times and temperatures, rinsing conditions, and sizes of particles generated by grinding. In contrast, the present apparatus is amenable to such investigations. The apparatus (see figure) includes a processing tank and a jacketed holding or coagulation tank. The processing tank can be capped by either of two different heads and can contain either of two different insertable mesh baskets. The first head includes a grinding blade and heating elements. The second head includes an automated press piston. One mesh basket, designated the okara basket, has oblong holes with a size equivalent to about 40 mesh [40 openings per inch (.16 openings per centimeter)]. The second mesh basket, designated the tofu basket, has holes of 70 mesh [70 openings

  18. Research Reproducibility in Geosciences: Current Landscape, Practices and Perspectives

    NASA Astrophysics Data System (ADS)

    Yan, An

    2016-04-01

    Reproducibility of research can gauge the validity of its findings. Yet currently we lack understanding of how much of a problem research reproducibility is in geosciences. We developed an online survey on faculty and graduate students in geosciences, and received 136 responses from research institutions and universities in Americas, Asia, Europe and other parts of the world. This survey examined (1) the current state of research reproducibility in geosciences by asking researchers' experiences with unsuccessful replication work, and what obstacles that lead to their replication failures; (2) the current reproducibility practices in community by asking what efforts researchers made to try to reproduce other's work and make their own work reproducible, and what the underlying factors that contribute to irreproducibility are; (3) the perspectives on reproducibility by collecting researcher's thoughts and opinions on this issue. The survey result indicated that nearly 80% of respondents who had ever reproduced a published study had failed at least one time in reproducing. Only one third of the respondents received helpful feedbacks when they contacted the authors of a published study for data, code, or other information. The primary factors that lead to unsuccessful replication attempts are insufficient details of instructions in published literature, and inaccessibility of data, code and tools needed in the study. Our findings suggest a remarkable lack of research reproducibility in geoscience. Changing the incentive mechanism in academia, as well as developing policies and tools that facilitate open data and code sharing are the promising ways for geosciences community to alleviate this reproducibility problem.

  19. Epitaxial thinning process

    NASA Technical Reports Server (NTRS)

    Siegel, C. M. (Inventor)

    1984-01-01

    A method is described for thinning an epitaxial layer of a wafer that is to be used in producing diodes having a specified breakdown voltage and which also facilitates the thinning process. Current is passed through the epitaxial layer, by connecting a current source between the substrate of the wafer and an electrolyte in which the wafer is immersed. When the wafer is initially immersed, the voltage across the wafer initially drops and then rises at a steep rate. When light is applied to the wafer the voltage drops, and when the light is interrupted the voltage rises again. These changes in voltage, each indicate the breakdown voltage of a Schottky diode that could be prepared from the wafer at that time. The epitaxial layer is thinned by continuing to apply current through the wafer while it is immersed and light is applied, to form an oxide film and when the oxide film is thick the wafer can then be cleaned of oxide and the testing and thinning continued. Uninterrupted thinning can be achieved by first forming an oxide film, and then using an electrolyte that dissolves the oxide about as fast as it is being formed, to limit the thickness of the oxide layer.

  20. A simple and reproducible capacitive electrode.

    PubMed

    Spinelli, Enrique; Guerrero, Federico; García, Pablo; Haberman, Marcelo

    2016-03-01

    Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed. When electrodes are placed on the skin; that is, with coupling capacitances C(S) of around 100 pF, they present a noise level of 3.3 µV(RMS) in a 0.5-100 Hz bandwidth, which is appropriate for electrocardiography (ECG) measurements. Construction details of the CE and the complete circuit, including a fast recovery feature, are presented.

  1. Large-area, reproducible and sensitive plasmonic MIM substrates for surface-enhanced Raman scattering

    NASA Astrophysics Data System (ADS)

    Li, Kuanguo; Wang, Yong; Jiang, Kang; Ren, Yuan; Dai, Yanqiu; Lu, Yonghua; Wang, Pei

    2016-12-01

    Vertically coupled plasmonic structure is of great interest for surface-enhanced Raman scattering (SERS). In this paper, a large-area reproducible SERS substrate is fabricated and demonstrated by a vertically coupled structure composed of Ag triangle arrays on Ag films separated by a nanometric dielectric layer. This metal-insulator-metal (MIM) nanostructure has broadband resonance covering both the laser excitation and Stokes frequencies. Thanks to the convenience of controlling the gap distance by thin dielectric film, the SERS substrate is optimized to yield the best enhancement. The SERS enhancement factor is estimated to be 5.8 × 106 for on-resonant pumping with a 532 nm laser. The uniformity and reproducibility of the SERS substrate are also demonstrated. Our results pave the way for rational design of sensitive SERS substrates and harmless exciting SERS signals.

  2. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Lan; Lin, Xianzhong; Ennaoui, Ahmed; Wolf, Christian; Lux-Steiner, Martha Ch.; Klenk, Reiner

    2016-02-01

    We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating and inkjet printing. Active area efficiencies of 12.8% and 12.2% have been achieved for In2S3-buffered solar cells respectively, matching the performance of CdS-buffered cells prepared with the same batch of absorbers.

  3. Device Engineering Towards Improved Tin Sulfide Solar Cell Performance and Performance Reproducibility

    SciTech Connect

    Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul; Siol, Sebastian; Martinot, Loic; Polizzotti, Alex; Yang, Chuanxi; Hartman, Katy; Gradecak, Silvija; Zakutayev, Andriy; Gordon, Roy G.; Buonassisi, Tonio

    2016-11-21

    As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to rapidly test promising candidates in high-performing PV devices. There is a need to engineer new compatible device architectures, including the development of novel transparent conductive oxides and buffer layers. Here, we consider the two approaches of a substrate-style and a superstrate-style device architecture for novel thin-film solar cells. We use tin sulfide as a test absorber material. Upon device engineering, we demonstrate new approaches to improve device performance and performance reproducibility.

  4. Surface enhanced Raman scattering activity of TiN thin film prepared via nitridation of sol-gel derived TiO2 film

    NASA Astrophysics Data System (ADS)

    Dong, Zhanliang; Wei, Hengyong; Chen, Ying; Wang, Ruisheng; Zhao, Junhong; Lin, Jian; Bu, Jinglong; Wei, Yingna; Cui, Yi; Yu, Yun

    2015-10-01

    Surface-enhanced Raman scattering (SERS) is a powerful and non-destructive analytical technique tool for chemical and biological sensing applications. Metal-free SERS substrates have recently been developed by using semiconductor nanostructures. The optical property of TiN film is similar to that of gold. Besides that, its good chemical inertness and thermodynamic stability make TiN thin film an excellent candidate for SERS. In order to investigate its SERS activity, the TiN thin film was successfully prepared via direct nitridation of the sol-gel derived TiO2 thin film on the quartz substrate using ammonia gas as reducing agent. The crystallite structures and morphology of TiN thin film were determined by XRD, RAMAN and FE-SEM. The results show that the thin film obtained is cubic titanium nitride with a lattice parameter of 4.2349 Å. The surface of TiN thin film is rough and with the particles of 50 nm in average sizes. The thickness of TiN thin film is about 130 nm. The TiN thin film displays a surface Plasmon resonance absorption peak at around 476 nm, which can lead to a strong enhancement of the EM field on the interface. The Raman signal of the probe molecule R6G was greatly enhanced through TiN thin film substrates. The enhancement factor is about 4.1×103 and the detection limit achieves 10-6 M for R6G. The TiN thin film substrate also shows a good reproducibility of SERS performance. The results indicate that TiN thin film is an attractive material with potential application in SERS substrates.

  5. Accuracy and reproducibility of cholesterol assay in the western Cape.

    PubMed

    Berger, G M; Christopher, K; Juritz, J M; Liesegang, F

    1988-11-19

    The accuracy and precision of cholesterol assay in the western Cape region is reported. The survey was carried out over 15 weeks utilising three human EDTA plasma pools with normal, borderline high and high cholesterol levels respectively. All 11 laboratories in the region providing a service to academic, provincial or military hospitals or to the private medical sector were included in the study. Ten of the 11 laboratories utilised automated enzymatic methods of cholesterol assay whereas 1 used a manual procedure based on the Liebermann-Burchard reaction. Methods were standardised by means of a variety of commercial calibrator material in all except 1 laboratory which used reference sera from the Centers for Disease Control, Atlanta. The performance of the 4 best laboratories met the standard of precision recommended for cholesterol assay, viz. total coefficient of variation of less than or equal to 2.5%. However, only 2 of the 11 laboratories achieved the optimum objective of an overall bias of less than 2.0% together with precision of less than or equal to 2.5%. Rational use of cholesterol assay for diagnosis and management will therefore require standardisation of cholesterol assay on a common reference material and greater attention to analytical factors influencing the reproducibility of results. Intrinsic biological variation also contributes uncertainty to the interpretation of a single value. Thus important clinical decisions must be based on two or more assays carried out using appropriate methodology.

  6. Method of producing thin cellulose nitrate film

    DOEpatents

    Lupica, S.B.

    1975-12-23

    An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent.

  7. Virtual Reference Environments: a simple way to make research reproducible

    PubMed Central

    Hurley, Daniel G.; Budden, David M.

    2015-01-01

    Reproducible research’ has received increasing attention over the past few years as bioinformatics and computational biology methodologies become more complex. Although reproducible research is progressing in several valuable ways, we suggest that recent increases in internet bandwidth and disk space, along with the availability of open-source and free-software licences for tools, enable another simple step to make research reproducible. In this article, we urge the creation of minimal virtual reference environments implementing all the tools necessary to reproduce a result, as a standard part of publication. We address potential problems with this approach, and show an example environment from our own work. PMID:25433467

  8. Virtual Reference Environments: a simple way to make research reproducible.

    PubMed

    Hurley, Daniel G; Budden, David M; Crampin, Edmund J

    2015-09-01

    'Reproducible research' has received increasing attention over the past few years as bioinformatics and computational biology methodologies become more complex. Although reproducible research is progressing in several valuable ways, we suggest that recent increases in internet bandwidth and disk space, along with the availability of open-source and free-software licences for tools, enable another simple step to make research reproducible. In this article, we urge the creation of minimal virtual reference environments implementing all the tools necessary to reproduce a result, as a standard part of publication. We address potential problems with this approach, and show an example environment from our own work.

  9. Integrating Epitaxial-Like Pb(Zr,Ti)O3 Thin-Film into Silicon for Next-Generation Ferroelectric Field-Effect Transistor

    PubMed Central

    Park, Jae Hyo; Kim, Hyung Yoon; Jang, Gil Su; Seok, Ki Hwan; Chae, Hee Jae; Lee, Sol Kyu; Kiaee, Zohreh; Joo, Seung Ki

    2016-01-01

    The development of ferroelectric random-access memory (FeRAM) technology with control of grain boundaries would result in a breakthrough for new nonvolatile memory devices. The excellent piezoelectric and electrical properties of bulk ferroelectrics are degraded when the ferroelectric is processed into thin films because the grain boundaries then form randomly. Controlling the nature of nucleation and growth are the keys to achieving a good crystalline thin-film. However, the sought after high-quality ferroelectric thin-film has so far been thought to be impossible to make, and research has been restricted to atomic-layer deposition which is extremely expensive and has poor reproducibility. Here we demonstrate a novel epitaxial-like growth technique to achieve extremely uniform and large rectangular-shaped grains in thin-film ferroelectrics by dividing the nucleation and growth phases. With this technique, it is possible to achieve 100-μm large uniform grains, even made available on Si, which is large enough to fabricate a field-effect transistor in each grain. The electrical and reliability test results, including endurance and retention test results, were superior to other FeRAMs reported so far and thus the results presented here constitute the first step toward the development of FeRAM using epitaxial-like ferroelectric thin-films. PMID:27005886

  10. Growth of oriented diamond on nickel wafers and thin films

    NASA Astrophysics Data System (ADS)

    Liu, Wei

    2000-10-01

    Growth of highly oriented diamond thin films on nickel was achieved by a multi-step process involving seeding, high temperature carbon dissolution, and growth. This process is very sensitive to the substrate temperature and requires accurate timing of both the nucleation and growth steps. It was observed that the surface morphology changed dramatically during the nucleation process and that in-situ monitoring of the surface morphology could provide valuable feedback for process control. An optical monitoring system developed under this study has significantly improved both the reproducibility and overall quality of the oriented diamond films grown on Ni substrates. However, since a significant fraction of carbon diffused into the bulk, as confirmed by Auger carbon depth profiling, the highest nucleation density on the bulk Ni substrate was 107 cm-2. To prevent carbon diffusion away from the surface and to maintain a supersaturated surface region, epitaxial nickel and iridium thin films were deposited by electron-beam evaporation on MgO which acted as a carbon diffusion barrier. A multi-layer structure with 100 A iridium and 1 mum nickel grown epitaxially on an MgO (100) wafer by electron-beam evaporation was used as a substrate. The 100 A thick Ir interlayer was used to overcome the delamination of Ni from the MgO substrate during processing. Oriented diamond was successfully deposited on these substrates and yielded nucleation densities of 3 x 108 cm-2, that resulted in faster coalescence of diamond particles. Coalesced diamond thin films on Ni/Ir/MgO substrates were grown in about six hours of growth, as compared to about 25 hours for the bulk Ni substrates. However, a much narrower process widow on Ni thin films made reproducible growth of oriented diamond more challenging. Cross-sectional high-resolution transmission electron microscopy (XHRTEM) was used to investigate the interfacial microstructure formed during hot filament chemical vapor deposition (HFCVD

  11. An Open Science and Reproducible Research Primer for Landscape Ecologists

    EPA Science Inventory

    In recent years many funding agencies, some publishers, and even the United States government have enacted policies that encourage open science and strive for reproducibility; however, the knowledge and skills to implement open science and enable reproducible research are not yet...

  12. 10 CFR 1016.35 - Authority to reproduce Restricted Data.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Authority to reproduce Restricted Data. 1016.35 Section 1016.35 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) SAFEGUARDING OF RESTRICTED DATA Control of... Restricted Data may be reproduced to the minimum extent necessary consistent with efficient operation...

  13. 10 CFR 1016.35 - Authority to reproduce Restricted Data.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Authority to reproduce Restricted Data. 1016.35 Section 1016.35 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) SAFEGUARDING OF RESTRICTED DATA Control of... Restricted Data may be reproduced to the minimum extent necessary consistent with efficient operation...

  14. Defect-free thin InAs nanowires grown using molecular beam epitaxy.

    PubMed

    Zhang, Zhi; Chen, Ping-Ping; Lu, Wei; Zou, Jin

    2016-01-21

    In this study, we designed a simple method to achieve the growth of defect-free thin InAs nanowires with a lateral dimension well below their Bohr radius on different substrate orientations. By depositing and annealing a thin layer of Au thin film on a (100) substrate surface, we have achieved the growth of defect-free uniform-sized thin InAs nanowires. This study provides a strategy to achieve the growth of pure defect-free thin nanowires.

  15. Precise interferometric length and phase-change measurement of gauge blocks based on reproducible wringing.

    PubMed

    Titov, A; Malinovsky, I; Belaïdi, H; França, R S; Massone, C A

    2000-02-01

    A modern fringe-pattern-analyzing interferometer with a resolution of 1 x 10(-9) and without exclusion of systematic uncertainties owing to optic effects of less than 1 nm was used to test a new method of interferometric length measurement based on a combination of the reproducible wringing and slave-block techniques. Measurements without excessive wringing film error are demonstrated for blocks with nominal lengths of 2-6 mm and with high surface flatness. The uncertainty achieved for these blocks is less than 1 nm. Deformations of steel gauge blocks and reference platens, caused by wringing forces, are investigated, and the necessary conditions for reproducible wringing are outlined. A subnanometer uncertainty level in phase-change-correction measurements has been achieved for gauge blocks as long as 100 mm. Limitations on the accuracy standard method of interferometric length measurements and shortcomings of the present definition of the length of the material artifact are emphasized.

  16. An open investigation of the reproducibility of cancer biology research.

    PubMed

    Errington, Timothy M; Iorns, Elizabeth; Gunn, William; Tan, Fraser Elisabeth; Lomax, Joelle; Nosek, Brian A

    2014-12-10

    It is widely believed that research that builds upon previously published findings has reproduced the original work. However, it is rare for researchers to perform or publish direct replications of existing results. The Reproducibility Project: Cancer Biology is an open investigation of reproducibility in preclinical cancer biology research. We have identified 50 high impact cancer biology articles published in the period 2010-2012, and plan to replicate a subset of experimental results from each article. A Registered Report detailing the proposed experimental designs and protocols for each subset of experiments will be peer reviewed and published prior to data collection. The results of these experiments will then be published in a Replication Study. The resulting open methodology and dataset will provide evidence about the reproducibility of high-impact results, and an opportunity to identify predictors of reproducibility.

  17. An open investigation of the reproducibility of cancer biology research

    PubMed Central

    Errington, Timothy M; Iorns, Elizabeth; Gunn, William; Tan, Fraser Elisabeth; Lomax, Joelle; Nosek, Brian A

    2014-01-01

    It is widely believed that research that builds upon previously published findings has reproduced the original work. However, it is rare for researchers to perform or publish direct replications of existing results. The Reproducibility Project: Cancer Biology is an open investigation of reproducibility in preclinical cancer biology research. We have identified 50 high impact cancer biology articles published in the period 2010-2012, and plan to replicate a subset of experimental results from each article. A Registered Report detailing the proposed experimental designs and protocols for each subset of experiments will be peer reviewed and published prior to data collection. The results of these experiments will then be published in a Replication Study. The resulting open methodology and dataset will provide evidence about the reproducibility of high-impact results, and an opportunity to identify predictors of reproducibility. DOI: http://dx.doi.org/10.7554/eLife.04333.001 PMID:25490932

  18. Thin Clouds

    Atmospheric Science Data Center

    2013-04-18

    ... one of a new generation of instruments flying aboard the NASA Earth Observing System's Terra satellite, views Earth with nine cameras ... of thin cirrus minutes after MISR imaged the cloud from space. At the same time, another NASA high-altitude jet, the WB-57, flew right ...

  19. Block Copolymer Thin Films: Patterns and Patterning

    NASA Astrophysics Data System (ADS)

    Register, Richard A.

    2001-03-01

    The nanostructures ("microdomains") in thin block copolymer films make excellent contact masks for surface patterning on the nanoscale. Using these thin films as templates, we have developed techniques based on reactive ion etching to uniformly and completely pattern the underlying substrate with a dense periodic pattern of dots, holes, or lines, with widths of order 20 nm. In addition, we have fabricated arrays of metal dots by backfilling these holes, and GaAs quantum dots by regrowth onto patterned GaAs substrates. A key issue in this nanopatterning approach is controlling the pattern which forms within the mask. While the local structure of the pattern (e.g., spheres vs. cylinders) is easily controlled through block copolymer composition, the long-range order ("grain size") is more difficult to manipulate. For cylinder-forming diblocks, we find that the correlation length of the microdomains grows as a weak power of annealing time, approximately 1/4. The principal types of defects which destroy the long-range order of the microdomains are disclinations. Sequential AFM images taken on the same region of the film after varying annealing times can be strung together into "movies" (to be shown at the talk) which directly show that the principal mode of defect annihilation (and hence grain growth) is the annihilation of disclination quadrupoles (pairs of +1/2 and -1/2 disclinations). We propose a model for quadrupole annihilation which reproduces the 1/4 exponent. Preliminary results for sphere-forming systems suggest that the exponent there is even lower than 1/4, making it difficult to achieve a significant degree of coarsening by extending the annealing time. * in collaboration with D.H. Adamson, P.M. Chaikin, Z. Cheng, P.D. Dapkus (USC), C.K. Harrison, D.A. Huse, R.R. Li (USC), and M. Park.

  20. Graded Achievement, Tested Achievement, and Validity

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  1. Holocene thinning of the Greenland ice sheet.

    PubMed

    Vinther, B M; Buchardt, S L; Clausen, H B; Dahl-Jensen, D; Johnsen, S J; Fisher, D A; Koerner, R M; Raynaud, D; Lipenkov, V; Andersen, K K; Blunier, T; Rasmussen, S O; Steffensen, J P; Svensson, A M

    2009-09-17

    On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. The previous interpretation of evidence from stable isotopes (delta(18)O) in water from GIS ice cores was that Holocene climate variability on the GIS differed spatially and that a consistent Holocene climate optimum-the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records-did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing delta(18)O from GIS ice cores with delta(18)O from ice cores from small marginal icecaps. Contrary to the earlier interpretation of delta(18)O evidence from ice cores, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our delta(18)O-based results are corroborated by the air content of ice cores, a proxy for surface elevation. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate.

  2. Reproducible LTE uplink performance analysis using precomputed interference signals

    NASA Astrophysics Data System (ADS)

    Pauli, Volker; Nisar, Muhammad Danish; Seidel, Eiko

    2011-12-01

    The consideration of realistic uplink inter-cell interference is essential for the overall performance testing of future cellular systems, and in particular for the evaluation of the radio resource management (RRM) algorithms. Most beyond-3G communication systems employ orthogonal multiple access in uplink (SC-FDMA in LTE and OFDMA in WiMAX), and additionally rely on frequency-selective RRM (scheduling) algorithms. This makes the task of accurate modeling of uplink interference both crucial and non-trivial. Traditional methods for its modeling (e.g., via additive white Gaussian noise interference sources) are therefore proving to be ineffective to realistically model the uplink interference in the next generation cellular systems. In this article, we propose the use of realistic precomputed interference patterns for LTE uplink performance analysis and testing. The interference patterns are generated via an LTE system-level simulator for a given set of scenario parameters, such as cell configuration, user configurations, and traffic models. The generated interference patterns (some of which are made publicly available) can be employed to benchmark the performance of any LTE uplink system in both lab simulations and field trials for practical deployments. It is worth mentioning that the proposed approach can also be extended to other cellular communication systems employing OFDMA-like multiple access with frequency-selective RRM techniques. The proposed approach offers twofold advantages. First, it allows for repeatability and reproducibility of the performance analysis. This is of crucial significance not only for researchers and developers to analyze the behavior and performance of their systems, but also for the network operators to compare the performance of competing system vendors. Second, the proposed testing mechanism evades the need for deployment of multiple cells (with multiple active users in each) to achieve realistic field trials, thereby resulting in

  3. Thin Film?

    NASA Astrophysics Data System (ADS)

    Kariper, İ. Afşin

    2014-09-01

    This study focuses on the critical surface tension of lead sulfite (PbSO3) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO3 thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO3 thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.

  4. Photographic copy of reproduced photograph dated 1942. Exterior view, west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of reproduced photograph dated 1942. Exterior view, west elevation. Building camouflaged during World War II. - Grand Central Air Terminal, 1310 Air Way, Glendale, Los Angeles County, CA

  5. Reproducibility of computational workflows is automated using continuous analysis.

    PubMed

    Beaulieu-Jones, Brett K; Greene, Casey S

    2017-03-13

    Replication, validation and extension of experiments are crucial for scientific progress. Computational experiments are scriptable and should be easy to reproduce. However, computational analyses are designed and run in a specific computing environment, which may be difficult or impossible to match using written instructions. We report the development of continuous analysis, a workflow that enables reproducible computational analyses. Continuous analysis combines Docker, a container technology akin to virtual machines, with continuous integration, a software development technique, to automatically rerun a computational analysis whenever updates or improvements are made to source code or data. This enables researchers to reproduce results without contacting the study authors. Continuous analysis allows reviewers, editors or readers to verify reproducibility without manually downloading and rerunning code and can provide an audit trail for analyses of data that cannot be shared.

  6. Flexible thin film magnetoimpedance sensors

    NASA Astrophysics Data System (ADS)

    Kurlyandskaya, G. V.; Fernández, E.; Svalov, A.; Burgoa Beitia, A.; García-Arribas, A.; Larrañaga, A.

    2016-10-01

    Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz.

  7. Comment on "Estimating the reproducibility of psychological science".

    PubMed

    Gilbert, Daniel T; King, Gary; Pettigrew, Stephen; Wilson, Timothy D

    2016-03-04

    A paper from the Open Science Collaboration (Research Articles, 28 August 2015, aac4716) attempting to replicate 100 published studies suggests that the reproducibility of psychological science is surprisingly low. We show that this article contains three statistical errors and provides no support for such a conclusion. Indeed, the data are consistent with the opposite conclusion, namely, that the reproducibility of psychological science is quite high.

  8. Reproducibility with repeat CT in radiomics study for rectal cancer

    PubMed Central

    Hu, Panpan; Wang, Jiazhou; Zhong, Haoyu; Zhou, Zhen; Shen, Lijun; Hu, Weigang; Zhang, Zhen

    2016-01-01

    Purpose To evaluate the reproducibility of radiomics features by repeating computed tomographic (CT) scans in rectal cancer. To choose stable radiomics features for rectal cancer. Results Volume normalized features are much more reproducible than unnormalized features. The average value of all slices is the most reproducible feature type in rectal cancer. Different filters have little effect for the reproducibility of radiomics features. For the average type features, 496 out of 775 features showed high reproducibility (ICC ≥ 0.8), 225 out of 775 features showed medium reproducibility (0.8 > ICC ≥ 0.5) and 54 out of 775 features showed low reproducibility (ICC < 0.5). Methods 40 rectal cancer patients with stage II were enrolled in this study, each of whom underwent two CT scans within average 8.7 days. 775 radiomics features were defined in this study. For each features, five different values (value from the largest slice, maximum value, minimum value, average value of all slices and value from superposed intermediate matrix) were extracted. Meanwhile a LOG filter with different parameters was applied to these images to find stable filter value. Concordance correlation coefficients (CCC) and inter-class correlation coefficients (ICC) of two CT scans were calculated to assess the reproducibility, based on original features and volume normalized features. Conclusions Features are recommended to be normalized to volume in radiomics analysis. The average type radiomics features are the most stable features in rectal cancer. Further analysis of these features of rectal cancer can be warranted for treatment monitoring and prognosis prediction. PMID:27669756

  9. A new paradigm for reproducing and analyzing N-body simulations of planetary systems

    NASA Astrophysics Data System (ADS)

    Rein, Hanno; Tamayo, Daniel

    2017-01-01

    The reproducibility of experiments is one of the main principles of the scientific method. However, numerical N-body experiments, especially those of planetary systems, are currently not reproducible. In the most optimistic scenario, they can only be replicated in an approximate or statistical sense. Even if authors share their full source code and initial conditions, differences in compilers, libraries, operating systems or hardware often lead to qualitatively different results. We provide a new set of easy-to-use, open-source tools that address the above issues, allowing for exact (bit-by-bit) reproducibility of N-body experiments. In addition to generating completely reproducible integrations, we show that our framework also offers novel and innovative ways to analyze these simulations. As an example, we present a high-accuracy integration of the Solar System spanning 10 Gyrs, requiring several weeks to run on a modern CPU. In our framework we can not only easily access simulation data at predefined intervals for which we save snapshots, but at any time during the integration. We achieve this by integrating an on-demand reconstructed simulation forward in time from the nearest snapshot. This allows us to extract arbitrary quantities at any point in the saved simulation exactly (bit-by-bit), and within seconds rather than weeks. We believe that the tools we present in this paper offer a new paradigm for how N-body simulations are run, analyzed, and shared across the community.

  10. Bitwise identical compiling setup: prospective for reproducibility and reliability of Earth system modeling

    NASA Astrophysics Data System (ADS)

    Li, R.; Liu, L.; Yang, G.; Zhang, C.; Wang, B.

    2016-02-01

    Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is an essential technical support for Earth system modeling. With the fast development of computer software and hardware, a compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change in compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of code may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical) results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs in the codes of models and compilers and finally improve the reliability of Earth system modeling.

  11. Bitwise identical compiling setup: prospective for reproducibility and reliability of earth system modeling

    NASA Astrophysics Data System (ADS)

    Li, R.; Liu, L.; Yang, G.; Zhang, C.; Wang, B.

    2015-11-01

    Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is essential technical supports for Earth system modeling. With the fast development of computer software and hardware, compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change of compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of codes may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical) results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs or risks in the codes of models and compilers and finally improve the reliability of Earth system modeling.

  12. On The Reproducibility of Seasonal Land-surface Climate

    SciTech Connect

    Phillips, T J

    2004-10-22

    The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model land-surface variables in which the seasonal cycle is either included or excluded--the former case being pertinent to climate simulation, and the latter to seasonal anomaly prediction. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation. However, the overall degree of reproducibility depends strongly on the particular land-surface anomaly considered. It is also shown that the predictability of a land-surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability metrics. Implications of these results for climate model intercomparison projects and for operational forecasts of seasonal continental climate also are elaborated.

  13. Host thin films incorporating nanoparticles

    NASA Astrophysics Data System (ADS)

    Qureshi, Uzma

    The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

  14. Reproducing the hierarchy of disorder for Morpho-inspired, broad-angle color reflection

    PubMed Central

    Song, Bokwang; Johansen, Villads Egede; Sigmund, Ole; Shin, Jung H.

    2017-01-01

    The scales of Morpho butterflies are covered with intricate, hierarchical ridge structures that produce a bright, blue reflection that remains stable across wide viewing angles. This effect has been researched extensively, and much understanding has been achieved using modeling that has focused on the positional disorder among the identical, multilayered ridges as the critical factor for producing angular independent color. Realizing such positional disorder of identical nanostructures is difficult, which in turn has limited experimental verification of different physical mechanisms that have been proposed. In this paper, we suggest an alternative model of inter-structural disorder that can achieve the same broad-angle color reflection, and is applicable to wafer-scale fabrication using conventional thin film technologies. Fabrication of a thin film that produces pure, stable blue across a viewing angle of more than 120 ° is demonstrated, together with a robust, conformal color coating. PMID:28387328

  15. Corrections to the thin wall approximation in general relativity

    NASA Technical Reports Server (NTRS)

    Garfinkle, David; Gregory, Ruth

    1989-01-01

    The question is considered whether the thin wall formalism of Israel applies to the gravitating domain walls of a lambda phi(exp 4) theory. The coupled Einstein-scalar equations that describe the thick gravitating wall are expanded in powers of the thickness of the wall. The solutions of the zeroth order equations reproduce the results of the usual Israel thin wall approximation for domain walls. The solutions of the first order equations provide corrections to the expressions for the stress-energy of the wall and to the Israel thin wall equations. The modified thin wall equations are then used to treat the motion of spherical and planar domain walls.

  16. Shear Thinning of Noncolloidal Suspensions

    NASA Astrophysics Data System (ADS)

    Vázquez-Quesada, Adolfo; Tanner, Roger I.; Ellero, Marco

    2016-09-01

    Shear thinning—a reduction in suspension viscosity with increasing shear rates—is understood to arise in colloidal systems from a decrease in the relative contribution of entropic forces. The shear-thinning phenomenon has also been often reported in experiments with noncolloidal systems at high volume fractions. However its origin is an open theoretical question and the behavior is difficult to reproduce in numerical simulations where shear thickening is typically observed instead. In this letter we propose a non-Newtonian model of interparticle lubrication forces to explain shear thinning in noncolloidal suspensions. We show that hidden shear-thinning effects of the suspending medium, which occur at shear rates orders of magnitude larger than the range investigated experimentally, lead to significant shear thinning of the overall suspension at much smaller shear rates. At high particle volume fractions the local shear rates experienced by the fluid situated in the narrow gaps between particles are much larger than the averaged shear rate of the whole suspension. This allows the suspending medium to probe its high-shear non-Newtonian regime and it means that the matrix fluid rheology must be considered over a wide range of shear rates.

  17. Reproducible E. coli detection based on label-free SERS and mapping.

    PubMed

    Yang, Danting; Zhou, Haibo; Haisch, Christoph; Niessner, Reinhard; Ying, Yibin

    2016-01-01

    The biosensing for rapid detection of bacteria based on surface-enhanced Raman scattering (SERS) has been widely explored for recent years. It is still a challenge to achieve a high sensitive, reproducible label free detection method for bacteria. In this work, a label-free SERS detection method of Escherichia coli based on incubation with silver colloid was reported. Optimized incubation conditions including shaking speed, time and temperature were used to help construct a rapid SERS method for E. coli analysis. It was found that the enhancement of the Raman signal of E. coli could be achieved to 1.8×10(4) cps (counts per second) with high reproducibility. Three strains of E. coli DSM 1116/498/5695 could be successfully discriminated using such SERS method combining discriminant analysis. Finally, the lowest concentration of E. coli at 1×10(5) cell/mL can be detected by SERS mapping. Thus, our detection method offers higher sensitivity and reproducibility compared to previously reported label free simple-mixing methods, opening an avenue for developing various SERS-based biosensor.

  18. Reproducibility of parameters of postocclusive reactive hyperemia measured by diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Vidal-Rosas, Ernesto E.; Billings, Stephen A.; Chico, Timothy; Coca, Daniel

    2016-06-01

    The application of near-infrared spectroscopy (NIRS) to assess microvascular function has shown promising results. An important limitation when using a single source-detector pair, however, is the lack of depth sensitivity. Diffuse optical tomography (DOT) overcomes this limitation using an array of sources and detectors that allow the reconstruction of volumetric hemodynamic changes. This study compares the key parameters of postocclusive reactive hyperemia measured in the forearm using standard NIRS and DOT. We show that while the mean parameter values are similar for the two techniques, DOT achieves much better reproducibility, as measured by the intraclass correlation coefficient (ICC). We show that DOT achieves high reproducibility for muscle oxygen consumption (ICC: 0.99), time to maximal HbO2 (ICC: 0.94), maximal HbO2 (ICC: 0.99), and time to maximal HbT (ICC: 0.99). Absolute reproducibility as measured by the standard error of measurement is consistently smaller and close to zero (ideal value) across all parameters measured by DOT compared to NIRS. We conclude that DOT provides a more robust characterization of the reactive hyperemic response and show how the availability of volumetric hemodynamic changes allows the identification of areas of temporal consistency, which could help characterize more precisely the microvasculature.

  19. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    PubMed

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases.

  20. Rapid and reproducible determination of active gibberellins in citrus tissues by UPLC/ESI-MS/MS.

    PubMed

    Manzi, Matías; Gómez-Cadenas, Aurelio; Arbona, Vicent

    2015-09-01

    Phytohormone determination is crucial to explain the physiological mechanisms during growth and development. Therefore, rapid and precise methods are needed to achieve reproducible determination of phytohormones. Among many others, gibberellins (GAs) constitute a family of complex analytes as most of them share similar structure and chemical properties although only a few hold biological activity (namely GA1; GA3; GA4 and GA7). A method has been developed to extract GAs from plant tissues by mechanical disruption using ultrapure water as solvent and, in this way, ion suppression was reduced whereas sensitivity increased. Using this methodology, the four active GAs were separated and quantified by UPLC coupled to MS/MS using the isotope-labeled internal standards [(2)H2]-GA1 and [(2)H2]-GA4. To sum up, the new method provides a fast and reproducible protocol to determine bioactive GAs at low concentrations, using minimal amounts of sample and reducing the use of organic solvents.

  1. Reproducibility of Research Algorithms in GOES-R Operational Software

    NASA Astrophysics Data System (ADS)

    Kennelly, E.; Botos, C.; Snell, H. E.; Steinfelt, E.; Khanna, R.; Zaccheo, T.

    2012-12-01

    The research to operations transition for satellite observations is an area of active interest as identified by The National Research Council Committee on NASA-NOAA Transition from Research to Operations. Their report recommends improved transitional processes for bridging technology from research to operations. Assuring the accuracy of operational algorithm results as compared to research baselines, called reproducibility in this paper, is a critical step in the GOES-R transition process. This paper defines reproducibility methods and measurements for verifying that operationally implemented algorithms conform to research baselines, demonstrated with examples from GOES-R software development. The approach defines reproducibility for implemented algorithms that produce continuous data in terms of a traditional goodness-of-fit measure (i.e., correlation coefficient), while the reproducibility for discrete categorical data is measured using a classification matrix. These reproducibility metrics have been incorporated in a set of Test Tools developed for GOES-R and the software processes have been developed to include these metrics to validate both the scientific and numerical implementation of the GOES-R algorithms. In this work, we outline the test and validation processes and summarize the current results for GOES-R Level 2+ algorithms.

  2. Using prediction markets to estimate the reproducibility of scientific research

    PubMed Central

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A.; Johannesson, Magnus

    2015-01-01

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants’ individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a “statistically significant” finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications. PMID:26553988

  3. Reproducibility of the Structural Connectome Reconstruction across Diffusion Methods.

    PubMed

    Prčkovska, Vesna; Rodrigues, Paulo; Puigdellivol Sanchez, Ana; Ramos, Marc; Andorra, Magi; Martinez-Heras, Eloy; Falcon, Carles; Prats-Galino, Albert; Villoslada, Pablo

    2016-01-01

    Analysis of the structural connectomes can lead to powerful insights about the brain's organization and damage. However, the accuracy and reproducibility of constructing the structural connectome done with different acquisition and reconstruction techniques is not well defined. In this work, we evaluated the reproducibility of the structural connectome techniques by performing test-retest (same day) and longitudinal studies (after 1 month) as well as analyzing graph-based measures on the data acquired from 22 healthy volunteers (6 subjects were used for the longitudinal study). We compared connectivity matrices and tract reconstructions obtained with the most typical acquisition schemes used in clinical application: diffusion tensor imaging (DTI), high angular resolution diffusion imaging (HARDI), and diffusion spectrum imaging (DSI). We observed that all techniques showed high reproducibility in the test-retest analysis (correlation >.9). However, HARDI was the only technique with low variability (2%) in the longitudinal assessment (1-month interval). The intraclass coefficient analysis showed the highest reproducibility for the DTI connectome, however, with more sparse connections than HARDI and DSI. Qualitative (neuroanatomical) assessment of selected tracts confirmed the quantitative results showing that HARDI managed to detect most of the analyzed fiber groups and fanning fibers. In conclusion, we found that HARDI acquisition showed the most balanced trade-off between high reproducibility of the connectome, higher rate of path detection and of fanning fibers, and intermediate acquisition times (10-15 minutes), although at the cost of higher appearance of aberrant fibers.

  4. Validation and reproducibility of an Australian caffeine food frequency questionnaire.

    PubMed

    Watson, E J; Kohler, M; Banks, S; Coates, A M

    2017-01-05

    The aim of this study was to measure validity and reproducibility of a caffeine food frequency questionnaire (C-FFQ) developed for the Australian population. The C-FFQ was designed to assess average daily caffeine consumption using four categories of food and beverages including; energy drinks; soft drinks/soda; coffee and tea and chocolate (food and drink). Participants completed a seven-day food diary immediately followed by the C-FFQ on two consecutive days. The questionnaire was first piloted in 20 adults, and then, a validity/reproducibility study was conducted (n = 90 adults). The C-FFQ showed moderate correlations (r = .60), fair agreement (mean difference 63 mg) and reasonable quintile rankings indicating fair to moderate agreement with the seven-day food diary. To test reproducibility, the C-FFQ was compared to itself and showed strong correlations (r = .90), good quintile rankings and strong kappa values (κ = 0.65), indicating strong reproducibility. The C-FFQ shows adequate validity and reproducibility and will aid researchers in Australia to quantify caffeine consumption.

  5. Using prediction markets to estimate the reproducibility of scientific research.

    PubMed

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A; Johannesson, Magnus

    2015-12-15

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants' individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a "statistically significant" finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications.

  6. Reproducibility of radiomics for deciphering tumor phenotype with imaging

    PubMed Central

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H.

    2016-01-01

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research. PMID:27009765

  7. Making neurophysiological data analysis reproducible: why and how?

    PubMed

    Delescluse, Matthieu; Franconville, Romain; Joucla, Sébastien; Lieury, Tiffany; Pouzat, Christophe

    2012-01-01

    Reproducible data analysis is an approach aiming at complementing classical printed scientific articles with everything required to independently reproduce the results they present. "Everything" covers here: the data, the computer codes and a precise description of how the code was applied to the data. A brief history of this approach is presented first, starting with what economists have been calling replication since the early eighties to end with what is now called reproducible research in computational data analysis oriented fields like statistics and signal processing. Since efficient tools are instrumental for a routine implementation of these approaches, a description of some of the available ones is presented next. A toy example demonstrates then the use of two open source software programs for reproducible data analysis: the "Sweave family" and the org-mode of emacs. The former is bound to R while the latter can be used with R, Matlab, Python and many more "generalist" data processing software. Both solutions can be used with Unix-like, Windows and Mac families of operating systems. It is argued that neuroscientists could communicate much more efficiently their results by adopting the reproducible research paradigm from their lab books all the way to their articles, thesis and books.

  8. Reproducibility of radiomics for deciphering tumor phenotype with imaging.

    PubMed

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H

    2016-03-24

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research.

  9. Reproducibility of radiomics for deciphering tumor phenotype with imaging

    NASA Astrophysics Data System (ADS)

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H.

    2016-03-01

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research.

  10. Reproducibility of regional brain metabolic responses to lorazepam

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Overall, J. |

    1996-10-01

    Changes in regional brain glucose metabolism in response to benzodiazepine agonists have been used as indicators of benzodiazepine-GABA receptor function. The purpose of this study was to assess the reproducibility of these responses. Sixteen healthy right-handed men underwent scanning with PET and [{sup 18}F]fluorodeoxyglucose (FDG) twice: before placebo and before lorazepam (30 {mu}g/kg). The same double FDG procedure was repeated 6-8 wk later on the men to assess test-retest reproducibility. The regional absolute brain metabolic values obtained during the second evaluation were significantly lower than those obtained from the first evaluation regardless of condition (p {le} 0.001). Lorazepam significantly and consistently decreased both whole-brain metabolism and the magnitude. The regional pattern of the changes were comparable for both studies (12.3% {plus_minus} 6.9% and 13.7% {plus_minus} 7.4%). Lorazepam effects were the largest in the thalamus (22.2% {plus_minus} 8.6% and 22.4% {plus_minus} 6.9%) and occipital cortex (19% {plus_minus} 8.9% and 21.8% {plus_minus} 8.9%). Relative metabolic measures were highly reproducible both for pharmacolgic and replication condition. This study measured the test-retest reproducibility in regional brain metabolic responses, and although the global and regional metabolic values were significantly lower for the repeated evaluation, the response to lorazepam was highly reproducible. 1613 refs., 3 figs., 3 tabs.

  11. Reproducibility of thalamic segmentation based on probabilistic tractography.

    PubMed

    Traynor, Catherine; Heckemann, Rolf A; Hammers, Alexander; O'Muircheartaigh, Jonathan; Crum, William R; Barker, Gareth J; Richardson, Mark P

    2010-08-01

    Reliable identification of thalamic nuclei is required to improve targeting of electrodes used in Deep Brain Stimulation (DBS), and for exploring the role of thalamus in health and disease. A previously described method using probabilistic tractography to segment the thalamus based on connections to cortical target regions was implemented. Both within- and between-subject reproducibility were quantitatively assessed by the overlap of the resulting segmentations; the effect of two different numbers of target regions (6 and 31) on reproducibility of the segmentation results was also investigated. Very high reproducibility was observed when a single dataset was processed multiple times using different starting conditions. Thalamic segmentation was also very reproducible when multiple datasets from the same subject were processed using six cortical target regions. Within-subject reproducibility was reduced when the number of target regions was increased, particularly in medial and posterior regions of the thalamus. A large degree of overlap in segmentation results from different subjects was obtained, particularly in thalamic regions classified as connecting to frontal, parietal, temporal and pre-central cortical target regions.

  12. Relevant principal factors affecting the reproducibility of insect primary culture.

    PubMed

    Ogata, Norichika; Iwabuchi, Kikuo

    2017-02-22

    The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.

  13. Reproducibility of cephalometric measurements made by three radiology clinics.

    PubMed

    da Silveira, Heraldo Luis Dias; Silveira, Heloisa Emilia Dias

    2006-05-01

    The purpose of this study was to assess reproducibility of cephalometric measurements in cephalograms obtained by three dentomaxillofacial radiology clinics. Forty lateral cephalometric radiographs were selected and sent at different times to three different clinics for cephalometric analyses. Each clinic digitized the radiographs with the same resolution, and landmarks were located with the mouse pointer directly on the digitized radiographic image on the screen. Three cephalograms were obtained from each radiograph, totaling 120 analyses. Data were analyzed with analysis of variance. Of the 32 factors studied, reproducibility of results was satisfactory for only four factors: position of maxilla relative to anterior cranial base, inclination of occlusal plane relative to anterior cranial base, position of lower incisor relative to nasion-pogonion line, and soft-tissue profile of face (P < .05). Differences in cephalometric measurements were present and such differences were significant for most factors analyzed. The different cephalometric measurements obtained by the three dental radiology clinics were not reproducible.

  14. Leader as achiever.

    PubMed

    Dienemann, Jacqueline

    2002-01-01

    This article examines one outcome of leadership: productive achievement. Without achievement one is judged to not truly be a leader. Thus, the ideal leader must be a visionary, a critical thinker, an expert, a communicator, a mentor, and an achiever of organizational goals. This article explores the organizational context that supports achievement, measures of quality nursing care, fiscal accountability, leadership development, rewards and punishments, and the educational content and teaching strategies to prepare graduates to be achievers.

  15. Benchmarking contactless acquisition sensor reproducibility for latent fingerprint trace evidence

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Mario; Dittmann, Jana

    2015-03-01

    Optical, nano-meter range, contactless, non-destructive sensor devices are promising acquisition techniques in crime scene trace forensics, e.g. for digitizing latent fingerprint traces. Before new approaches are introduced in crime investigations, innovations need to be positively tested and quality ensured. In this paper we investigate sensor reproducibility by studying different scans from four sensors: two chromatic white light sensors (CWL600/CWL1mm), one confocal laser scanning microscope, and one NIR/VIS/UV reflection spectrometer. Firstly, we perform an intra-sensor reproducibility testing for CWL600 with a privacy conform test set of artificial-sweat printed, computer generated fingerprints. We use 24 different fingerprint patterns as original samples (printing samples/templates) for printing with artificial sweat (physical trace samples) and their acquisition with contactless sensory resulting in 96 sensor images, called scan or acquired samples. The second test set for inter-sensor reproducibility assessment consists of the first three patterns from the first test set, acquired in two consecutive scans using each device. We suggest using a simple feature space set in spatial and frequency domain known from signal processing and test its suitability for six different classifiers classifying scan data into small differences (reproducible) and large differences (non-reproducible). Furthermore, we suggest comparing the classification results with biometric verification scores (calculated with NBIS, with threshold of 40) as biometric reproducibility score. The Bagging classifier is nearly for all cases the most reliable classifier in our experiments and the results are also confirmed with the biometric matching rates.

  16. Effects of Thermochemical Treatment on CuSbS 2 Photovoltaic Absorber Quality and Solar Cell Reproducibility

    SciTech Connect

    de Souza Lucas, Francisco Willian; Welch, Adam W.; Baranowski, Lauryn L.; Dippo, Patricia C.; Hempel, Hannes; Unold, Thomas; Eichberger, Rainer; Blank, Beatrix; Rau, Uwe; Mascaro, Lucia H.; Zakutayev, Andriy

    2016-08-25

    CuSbS2 is a promising nontoxic and earth-abundant photovoltaic absorber that is chemically simpler than the widely studied Cu2ZnSnS4. However, CuSbS2 photovoltaic (PV) devices currently have relatively low efficiency and poor reproducibility, often due to suboptimal material quality and insufficient optoelectronic properties. To address these issues, here we develop a thermochemical treatment (TT) for CuSbS2 thin films, which consists of annealing in Sb2S3 vapor followed by a selective KOH surface chemical etch. The annealed CuSbS2 films show improved structural quality and optoelectronic properties, such as stronger band-edge photoluminescence and longer photoexcited carrier lifetime. These improvements also lead to more reproducible CuSbS2 PV devices, with performance currently limited by a large cliff-type interface band offset with CdS contact. Overall, these results point to the potential avenues to further increase the performance of CuSbS2 thin film solar cell, and the findings can be transferred to other thin film photovoltaic technologies.

  17. Measurement of Liver Iron Concentration by MRI Is Reproducible

    PubMed Central

    Alústiza, José María; Emparanza, José I.; Castiella, Agustín; Casado, Alfonso; Aldazábal, Pablo; San Vicente, Manuel; Garcia, Nerea; Asensio, Ana Belén; Banales, Jesús; Salvador, Emma; Moyua, Aranzazu; Arozena, Xabier; Zarco, Miguel; Jauregui, Lourdes; Vicente, Ohiana

    2015-01-01

    Purpose. The objectives were (i) construction of a phantom to reproduce the behavior of iron overload in the liver by MRI and (ii) assessment of the variability of a previously validated method to quantify liver iron concentration between different MRI devices using the phantom and patients. Materials and Methods. A phantom reproducing the liver/muscle ratios of two patients with intermediate and high iron overload. Nine patients with different levels of iron overload were studied in 4 multivendor devices and 8 of them were studied twice in the machine where the model was developed. The phantom was analysed in the same equipment and 14 times in the reference machine. Results. FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom. The average of the intramachine variability for patients was 10% and for the intermachines 8%. For the phantom the intramachine coefficient of variation was always below 0.1 and the average of intermachine variability was 10% for moderate and 5% for high iron overload. Conclusion. The phantom reproduces the behavior of patients with moderate or high iron overload. The proposed method of calculating liver iron concentration is reproducible in several different 1.5 T systems. PMID:25874207

  18. ReproPhylo: An Environment for Reproducible Phylogenomics.

    PubMed

    Szitenberg, Amir; John, Max; Blaxter, Mark L; Lunt, David H

    2015-09-01

    The reproducibility of experiments is key to the scientific process, and particularly necessary for accurate reporting of analyses in data-rich fields such as phylogenomics. We present ReproPhylo, a phylogenomic analysis environment developed to ensure experimental reproducibility, to facilitate the handling of large-scale data, and to assist methodological experimentation. Reproducibility, and instantaneous repeatability, is built in to the ReproPhylo system and does not require user intervention or configuration because it stores the experimental workflow as a single, serialized Python object containing explicit provenance and environment information. This 'single file' approach ensures the persistence of provenance across iterations of the analysis, with changes automatically managed by the version control program Git. This file, along with a Git repository, are the primary reproducibility outputs of the program. In addition, ReproPhylo produces an extensive human-readable report and generates a comprehensive experimental archive file, both of which are suitable for submission with publications. The system facilitates thorough experimental exploration of both parameters and data. ReproPhylo is a platform independent CC0 Python module and is easily installed as a Docker image or a WinPython self-sufficient package, with a Jupyter Notebook GUI, or as a slimmer version in a Galaxy distribution.

  19. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... joint tightness, mechanical strength and the nature of the fluid handled....

  20. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... joint tightness, mechanical strength and the nature of the fluid handled....

  1. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... joint tightness, mechanical strength and the nature of the fluid handled....

  2. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... joint tightness, mechanical strength and the nature of the fluid handled....

  3. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... joint tightness, mechanical strength and the nature of the fluid handled....

  4. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  5. Latin America Today: An Atlas of Reproducible Pages. Revised Edition.

    ERIC Educational Resources Information Center

    World Eagle, Inc., Wellesley, MA.

    This document contains reproducible maps, charts and graphs of Latin America for use by teachers and students. The maps are divided into five categories (1) the land; (2) peoples, countries, cities, and governments; (3) the national economies, product, trade, agriculture, and resources; (4) energy, education, employment, illicit drugs, consumer…

  6. Reproducibility of heart rate turbulence indexes in heart failure patients.

    PubMed

    D'Addio, Gianni; Cesarelli, Mario; Corbi, Graziamaria; Romano, Maria; Furgi, Giuseppe; Ferrara, Nicola; Rengo, Franco

    2010-01-01

    Cardiovascular oscillations following spontaneous ventricular premature complexes (VPC) are characterized by a short-term heart rate fluctuation known as heart rate turbulence (HRT) described by the so-called turbulence onset (TO) and slope (TS). Despite a recent written consensus on the standard of HRT measurement, reproducibility data are lacking. Aim of the paper was a reproducibility study of HRT indexes in heart failure patients (HF). Eleven HF patients underwent two 24h ECG Holter recordings, spaced 7 ± 5 days. A paired t test was used to assess the clinical stability of patients during the study period and the number of PVC in Holter recordings' couples. Both TO and TS indexes were calculated for each isolated VPC, and due to their skewed distribution, reproducibility of median and mean TO and TS was studied by Bland-Altman technique. Results showed that median HRT indexes might be preferred to commonly suggested mean values and that, although TO showed lower bias value than TS, TS can be considered much more reproducible than TO, comparing limits of agreements with normal values. This preliminary results suggest the use of medians instead of mean HRT indexes values and a reliability of the turbulence slope greater than the turbulence onset index.

  7. Reproducibility of Manual Platelet Estimation Following Automated Low Platelet Counts

    PubMed Central

    Al-Hosni, Zainab S; Al-Khabori, Murtadha; Al-Mamari, Sahimah; Al-Qasabi, Jamal; Davis, Hiedi; Al-Lawati, Hatim; Al-Riyami, Arwa Z

    2016-01-01

    Objectives Manual platelet estimation is one of the methods used when automated platelet estimates are very low. However, the reproducibility of manual platelet estimation has not been adequately studied. We sought to assess the reproducibility of manual platelet estimation following automated low platelet counts and to evaluate the impact of the level of experience of the person counting on the reproducibility of manual platelet estimates. Methods In this cross-sectional study, peripheral blood films of patients with platelet counts less than 100 × 109/L were retrieved and given to four raters to perform manual platelet estimation independently using a predefined method (average of platelet counts in 10 fields using 100× objective multiplied by 20). Data were analyzed using intraclass correlation coefficient (ICC) as a method of reproducibility assessment. Results The ICC across the four raters was 0.840, indicating excellent agreement. The median difference of the two most experienced raters was 0 (range: -64 to 78). The level of platelet estimate by the least-experienced rater predicted the disagreement (p = 0.037). When assessing the difference between pairs of raters, there was no significant difference in the ICC (p = 0.420). Conclusions The agreement between different raters using manual platelet estimation was excellent. Further confirmation is necessary, with a prospective study using a gold standard method of platelet counts. PMID:27974955

  8. ReproPhylo: An Environment for Reproducible Phylogenomics

    PubMed Central

    Szitenberg, Amir; John, Max; Blaxter, Mark L.; Lunt, David H.

    2015-01-01

    The reproducibility of experiments is key to the scientific process, and particularly necessary for accurate reporting of analyses in data-rich fields such as phylogenomics. We present ReproPhylo, a phylogenomic analysis environment developed to ensure experimental reproducibility, to facilitate the handling of large-scale data, and to assist methodological experimentation. Reproducibility, and instantaneous repeatability, is built in to the ReproPhylo system and does not require user intervention or configuration because it stores the experimental workflow as a single, serialized Python object containing explicit provenance and environment information. This ‘single file’ approach ensures the persistence of provenance across iterations of the analysis, with changes automatically managed by the version control program Git. This file, along with a Git repository, are the primary reproducibility outputs of the program. In addition, ReproPhylo produces an extensive human-readable report and generates a comprehensive experimental archive file, both of which are suitable for submission with publications. The system facilitates thorough experimental exploration of both parameters and data. ReproPhylo is a platform independent CC0 Python module and is easily installed as a Docker image or a WinPython self-sufficient package, with a Jupyter Notebook GUI, or as a slimmer version in a Galaxy distribution. PMID:26335558

  9. How reproducible is the acoustical characterization of porous media?

    PubMed

    Pompoli, Francesco; Bonfiglio, Paolo; Horoshenkov, Kirill V; Khan, Amir; Jaouen, Luc; Bécot, François-Xavier; Sgard, Franck; Asdrubali, Francesco; D'Alessandro, Francesco; Hübelt, Jörn; Atalla, Noureddine; Amédin, Celse K; Lauriks, Walter; Boeckx, Laurens

    2017-02-01

    There is a considerable number of research publications on the characterization of porous media that is carried out in accordance with ISO 10534-2 (International Standards Organization, Geneva, Switzerland, 2001) and/or ISO 9053 (International Standards Organization, Geneva, Switzerland, 1991). According to the Web of Science(TM) (last accessed 22 September 2016) there were 339 publications in the Journal of the Acoustical Society of America alone which deal with the acoustics of porous media. However, the reproducibility of these characterization procedures is not well understood. This paper deals with the reproducibility of some standard characterization procedures for acoustic porous materials. The paper is an extension of the work published by Horoshenkov, Khan, Bécot, Jaouen, Sgard, Renault, Amirouche, Pompoli, Prodi, Bonfiglio, Pispola, Asdrubali, Hübelt, Atalla, Amédin, Lauriks, and Boeckx [J. Acoust. Soc. Am. 122(1), 345-353 (2007)]. In this paper, independent laboratory measurements were performed on the same material specimens so that the naturally occurring inhomogeneity in materials was controlled. It also presented the reproducibility data for the characteristic impedance, complex wavenumber, and for some related pore structure properties. This work can be helpful to better understand the tolerances of these material characterization procedures so improvements can be developed to reduce experimental errors and improve the reproducibility between laboratories.

  10. Tractography of the optic radiation: a repeatability and reproducibility study.

    PubMed

    Dayan, Michael; Kreutzer, Sylvia; Clark, Chris A

    2015-04-01

    Our main objective was to evaluate the repeatability and reproducibility of optic radiation (OR) reconstruction from diffusion MRI (dMRI) data. 14 adults were scanned twice with the same 60-direction dMRI sequence. Peaks in the diffusion profile were estimated with the single tensor (ST), Q-ball (QSH) and persistent angular structure (PAS) methods. Segmentation of the OR was performed by two experimenters with probabilistic tractography based on a manually drawn region-of-interest (ROI) protocol typically employed for OR segmentation, with both standard and extended sets of ROIs. The repeatability and reproducibility were assessed by calculating the intra-class correlation coefficient (ICC) of intra- and inter-rater experiments, respectively. ICCs were calculated for commonly used dMRI metrics (FA, MD, AD, RD) and anatomical dimensions of the optic radiation (distance from Meyer's loop to the temporal pole, ML-TP), as well as the Dice similarity coefficient (DSC) between the raters' OR segmentation. Bland-Altman plots were also calculated to investigate bias and variability in the reproducibility measurements. The OR was successfully reconstructed in all subjects by both raters. The ICC was found to be in the good to excellent range for both repeatability and reproducibility of the dMRI metrics, DSC and ML-TP distance. The Bland-Altman plots did not show any apparent systematic bias for any quantities. Overall, higher ICC values were found for the multi-fiber methods, QSH and PAS, and for the standard set of ROIs. Considering the good to excellent repeatability and reproducibility of all the quantities investigated, these findings support the use of multi-fiber OR reconstruction with a limited number of manually drawn ROIs in clinical applications utilizing either OR microstructure characterization or OR dimensions, as is the case in neurosurgical planning for temporal lobectomy.

  11. Reproducibility of anthropometric measurements in children: a longitudinal study.

    PubMed

    Leppik, Aire; Jürimäe, Toivo; Jürimäe, Jaak

    2004-03-01

    The purpose of this study was to establish the reproducibility of a series of anthropometric measures performed twice during one week during a three year period in boys and girls. The subjects of this investigation were 39 children (21 boys and 18 girls), 9-10 year of age at the beginning of the study. Children were measured three times with one year interval. Children were classified by Tanner stage 1-2 during the first measurements, stage 1-3 during the second measurements and stage 1-4 during the third measurements. Body height and weight were measured and BMI calculated. All anthropometric parameters were measured according to the protocol recommended by the International Society for the Advancement of Kinanthropometry (Norton & Olds 1996). Nine skinfolds, 13 girths, eight lengths and eight breadths/lengths were measured. The reproducibility of body height (r = 0.995-0.999), body weight (r = 0.990-0.999) and BMI (r = 0.969-0.999) was very high in boys and girls. The intraclass correlations (ICC), technical errors (TE) and coefficients of variation (CV) were quite different depending on the measurement site of the skinfold thickness. It was surprising that the ICCs were highest and TEs and CVs were lowest during the second year of the measurement. The computed ICC was high, and TE and CV values were quite similar and relatively low in girth, length and breadth/length measurements. It was concluded that the reproducibility of girths, lengths and breadths/lengths in children is very high and the reproducibility of skinfolds is high. Specifically, the reproducibility is very high immediately before puberty in boys and girls.

  12. Nanosecond structural visualization of the reproducibility of polarization switching in ferroelectrics.

    SciTech Connect

    Grigoriev, A.; Do, D. H.; Kim, D. M.; Eom, C. B.; Evans, P. G.; Adams, B. W.; Dufresne, E. M.; Univ. of Wisconsin at Madison

    2006-01-01

    As the polarization of a ferroelectric thin film reverses in response to an applied electric field, concomitant structural changes can be visualized using time-resolved x-ray microdiffraction. We report the details of this visualization approach and discuss the structural signature of polarization switching measured by time-resolved x-ray diffraction. The dynamics associated with polarization switching in ferroelectric devices have received continuous theoretical and experimental attention since the discovery of the remnant polarization of ferroelectric oxides. Even though the basic phenomena of domain nucleation and domain wall motion are reasonably well parameterized by conventional models, several important questions remain. For example, the relative importance of domain wall motion and nucleation, the scaling of domain wall velocities with the applied electric field, and ultimately the speed at which devices can be switched are not well known. The degree of repeatability of the domain wall dynamics from cycle to cycle of the electric field depends on these phenomena, and can be used to understand which processes are relevant in switching. Here we address the homogeneity and reproducibility of polarization switching in thin ferroelectric Pb(Zr,Ti)O{sub 3} (PZT) films using time-resolved x-ray microdiffraction.

  13. Fabrication of highly reproducible polymer solar cells using ultrasonic substrate vibration posttreatment

    NASA Astrophysics Data System (ADS)

    Xie, Yu; Zabihi, Fatemeh; Eslamian, Morteza

    2016-10-01

    Organic solar cells are usually nonreproducible due to the presence of defects in the structure of their constituting thin films. To minimize the density of pinholes and defects in PEDOT:PSS, which is the hole transporting layer of a standard polymer solar cell, i.e., glass/ITO/PEDOT:PSS/P3HT:PCBM/Al, and to reduce scattering in device performance, wet spun-on PEDOT:PSS films are subjected to imposed ultrasonic substrate vibration posttreatment (SVPT). The imposed vibration improves the mixing and homogeneity of the wet spun-on films, and consequently the nanostructure of the ensuing thin solid films. For instance, our results show that by using the SVPT, which is a mechanical, single-step and low-cost process, the average power conversion efficiency of 14 identical cells increases by 25% and the standard deviation decreases by 22% indicating that the device photovoltaic performance becomes more consistent and significantly improved. This eliminates several tedious and expensive chemical and thermal treatments currently performed to improve the cell reproducibility.

  14. Reproducible magnetostrain behavior induced by structure transformation for Ni46Co4Mn39Sn11 Heusler alloy

    NASA Astrophysics Data System (ADS)

    Li, Z.; Xu, K.; Zhang, Y. L.; Jing, C.

    2015-01-01

    This paper presents the strain behavior associated with martensitic transformation for polycrystalline Ni46Co4Mn39Sn11. The unique reproducible magnetostrain in this alloy has been realized within a magnetic field change of 3 T, and its maximum value achieves about 0.012% at 225 K, which is almost ten times higher than that in Ni-Mn-Sn ternary alloy. Such a reproducible phenomenon could be attributed to the occurrence of the reversible transformation between multi-variant martensite and austenite under an applied isothermal magnetic field.

  15. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  16. Transparency, usability, and reproducibility: Guiding principles for improving comparative databases using primates as examples.

    PubMed

    Borries, Carola; Sandel, Aaron A; Koenig, Andreas; Fernandez-Duque, Eduardo; Kamilar, Jason M; Amoroso, Caroline R; Barton, Robert A; Bray, Joel; Di Fiore, Anthony; Gilby, Ian C; Gordon, Adam D; Mundry, Roger; Port, Markus; Powell, Lauren E; Pusey, Anne E; Spriggs, Amanda; Nunn, Charles L

    2016-09-01

    Recent decades have seen rapid development of new analytical methods to investigate patterns of interspecific variation. Yet these cutting-edge statistical analyses often rely on data of questionable origin, varying accuracy, and weak comparability, which seem to have reduced the reproducibility of studies. It is time to improve the transparency of comparative data while also making these improved data more widely available. We, the authors, met to discuss how transparency, usability, and reproducibility of comparative data can best be achieved. We propose four guiding principles: 1) data identification with explicit operational definitions and complete descriptions of methods; 2) inclusion of metadata that capture key characteristics of the data, such as sample size, geographic coordinates, and nutrient availability (for example, captive versus wild animals); 3) documentation of the original reference for each datum; and 4) facilitation of effective interactions with the data via user friendly and transparent interfaces. We urge reviewers, editors, publishers, database developers and users, funding agencies, researchers publishing their primary data, and those performing comparative analyses to embrace these standards to increase the transparency, usability, and reproducibility of comparative studies.

  17. Validity and reproducibility of a food frequency questionnaire to assess food group intake in adolescents.

    PubMed

    Martinez, Marcelle Flores; Philippi, Sonia Tucunduva; Estima, Camilla; Leal, Greisse

    2013-09-01

    The objective of this study was to assess the validity and reproducibility of a food frequency questionnaire to assess intake of the food groups included in the food guide pyramid for adolescents (FFQ-FP). The final version of the FFQ-FP consisted of 50 food items. The study was carried out with a sample of 109 adolescents over a period of four months. A 24hr recall (24hr) was conducted four times and the FFQ-FP was conducted twice. Validity was determined by comparing the second FFQ-FP and the mean of the four 24hrs, while reproducibility was verified by comparing the results of the two FFQ-FPs. Statistical analysis was carried out using medians, standard deviations, Pearson and intraclass correlations and Kappa statistics to assess concordance. Best results were achieved for the rice (including bread, grains and starches), meats and sugars groups. Weakest correlation was observed for the variable vitamin C. The validity and reproducibility of the FFQ-FP was satisfactory for most variables.

  18. Which Achievement Gap?

    ERIC Educational Resources Information Center

    Anderson, Sharon; Medrich, Elliott; Fowler, Donna

    2007-01-01

    From the halls of Congress to the local elementary school, conversations on education reform have tossed around the term "achievement gap" as though people all know precisely what that means. As it's commonly used, "achievement gap" refers to the differences in scores on state or national achievement tests between various…

  19. A mechanism to thin the continental lithosphere at magma-poor margins.

    PubMed

    Lavier, Luc L; Manatschal, Gianreto

    2006-03-16

    Where continental plates break apart, slip along multiple normal faults provides the required space for the Earth's crust to thin and subside. After initial rifting, however, the displacement on normal faults observed at the sea floor seems not to match the inferred extension. Here we show that crustal thinning can be accomplished in such extensional environments by a system of conjugate concave downward faults instead of multiple normal faults. Our model predicts that these concave faults accumulate large amounts of extension and form a very thin crust (< 10 km) by exhumation of mid-crustal and mantle material. This transitional crust is capped by sub-horizontal detachment surfaces over distances exceeding 100 km with little visible deformation. Our rift model is based on numerical experiments constrained by geological and geophysical observations from the Alpine Tethys and Iberia/Newfoundland margins. Furthermore, we suggest that the observed transition from broadly distributed and symmetric extension to localized and asymmetric rifting is directly controlled by the existence of a strong gabbroic lower crust. The presence of such lower crustal gabbros is well constrained for the Alpine Tethys system. Initial decoupling of upper crustal deformation from lower crustal and mantle deformation by progressive weakening of the middle crust is an essential requirement to reproduce the observed rift evolution. This is achieved in our models by the formation of weak ductile shear zones.

  20. Composting in small laboratory pilots: Performance and reproducibility

    SciTech Connect

    Lashermes, G.; Barriuso, E.; Le Villio-Poitrenaud, M.; Houot, S.

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer We design an innovative small-scale composting device including six 4-l reactors. Black-Right-Pointing-Pointer We investigate the performance and reproducibility of composting on a small scale. Black-Right-Pointing-Pointer Thermophilic conditions are established by self-heating in all replicates. Black-Right-Pointing-Pointer Biochemical transformations, organic matter losses and stabilisation are realistic. Black-Right-Pointing-Pointer The organic matter evolution exhibits good reproducibility for all six replicates. - Abstract: Small-scale reactors (<10 l) have been employed in composting research, but few attempts have assessed the performance of composting considering the transformations of organic matter. Moreover, composting at small scales is often performed by imposing a fixed temperature, thus creating artificial conditions, and the reproducibility of composting has rarely been reported. The objectives of this study are to design an innovative small-scale composting device safeguarding self-heating to drive the composting process and to assess the performance and reproducibility of composting in small-scale pilots. The experimental setup included six 4-l reactors used for composting a mixture of sewage sludge and green wastes. The performance of the process was assessed by monitoring the temperature, O{sub 2} consumption and CO{sub 2} emissions, and characterising the biochemical evolution of organic matter. A good reproducibility was found for the six replicates with coefficients of variation for all parameters generally lower than 19%. An intense self-heating ensured the existence of a spontaneous thermophilic phase in all reactors. The average loss of total organic matter (TOM) was 46% of the initial content. Compared to the initial mixture, the hot water soluble fraction decreased by 62%, the hemicellulose-like fraction by 68%, the cellulose-like fraction by 50% and the lignin-like fractions by 12% in the final

  1. Reproducibility and Comparability of Computational Models for Astrocyte Calcium Excitability

    PubMed Central

    Manninen, Tiina; Havela, Riikka; Linne, Marja-Leena

    2017-01-01

    The scientific community across all disciplines faces the same challenges of ensuring accessibility, reproducibility, and efficient comparability of scientific results. Computational neuroscience is a rapidly developing field, where reproducibility and comparability of research results have gained increasing interest over the past years. As the number of computational models of brain functions is increasing, we chose to address reproducibility using four previously published computational models of astrocyte excitability as an example. Although not conventionally taken into account when modeling neuronal systems, astrocytes have been shown to take part in a variety of in vitro and in vivo phenomena including synaptic transmission. Two of the selected astrocyte models describe spontaneous calcium excitability, and the other two neurotransmitter-evoked calcium excitability. We specifically addressed how well the original simulation results can be reproduced with a reimplementation of the models. Additionally, we studied how well the selected models can be reused and whether they are comparable in other stimulation conditions and research settings. Unexpectedly, we found out that three of the model publications did not give all the necessary information required to reimplement the models. In addition, we were able to reproduce the original results of only one of the models completely based on the information given in the original publications and in the errata. We actually found errors in the equations provided by two of the model publications; after modifying the equations accordingly, the original results were reproduced more accurately. Even though the selected models were developed to describe the same biological event, namely astrocyte calcium excitability, the models behaved quite differently compared to one another. Our findings on a specific set of published astrocyte models stress the importance of proper validation of the models against experimental wet

  2. Canine olfaction as an alternative to analytical instruments for disease diagnosis: understanding 'dog personality' to achieve reproducible results.

    PubMed

    Hackner, Klaus; Pleil, Joachim

    2017-01-09

    Recent literature has touted the use of canine olfaction as a diagnostic tool for identifying pre-clinical disease status, especially cancer and infection from biological media samples. Studies have shown a wide range of outcomes, ranging from almost perfect discrimination, all the way to essentially random results. This disparity is not likely to be a detection issue; dogs have been shown to have extremely sensitive noses as proven by their use for tracking, bomb detection and search and rescue. However, in contrast to analytical instruments, dogs are subject to boredom, fatigue, hunger and external distractions. These challenges are of particular importance in a clinical environment where task repetition is prized, but not as entertaining for a dog as chasing odours outdoors. The question addressed here is how to exploit the intrinsic sensitivity and simplicity of having a dog simply sniff out disease, in the face of variability in behavior and response.

  3. Additive Manufacturing of 17-4 PH Stainless Steel: Post-processing Heat Treatment to Achieve Uniform Reproducible Microstructure

    NASA Astrophysics Data System (ADS)

    Cheruvathur, Sudha; Lass, Eric A.; Campbell, Carelyn E.

    2016-03-01

    17-4 precipitation hardenable (PH) stainless steel is a useful material when a combination of high strength and good corrosion resistance up to about 315°C is required. In the wrought form, this steel has a fully martensitic structure that can be strengthened by precipitation of fine Cu-rich face-centered cubic phase upon aging. When fabricated via additive manufacturing (AM), specifically laser powder-bed fusion, 17-4 PH steel exhibits a dendritic structure containing a substantial fraction of nearly 50% of retained austenite along with body centered cubic/martensite and fine niobium carbides preferentially aligned along interdendritic boundaries. The effect of post-build thermal processing on the material microstructure is studied in comparison to that of conventionally produced wrought 17-4 PH with the intention of creating a more uniform, fully martensitic microstructure. The recommended stress relief heat treatment currently employed in industry for post-processing of AM 17-4 PH steel is found to have little effect on the as-built dendritic microstructure. It is found that, by implementing the recommended homogenization heat treatment regimen of Aerospace Materials Specification 5355 for CB7Cu-1, a casting alloy analog to 17-4 PH, the dendritic solidification structure is eliminated, resulting in a microstructure containing about 90% martensite with 10% retained austenite.

  4. Canine olfaction as an alternative to analytical instruments for disease diagnosis: understanding 'dog personality' to achieve reproducible results

    EPA Science Inventory

    Recent literature has touted the use of canine olfaction as a diagnostic tool for identifying pre-clinical disease status, especially cancer and infection from biological media samples. Studies have shown a wide range of outcomes, ranging from almost perfect discrimination, all t...

  5. Thin Sections

    PubMed Central

    Peachey, Lee D.

    1958-01-01

    Knowledge of the thickness of sections is important for proper interpretation of electron micrographs. Therefore, the thicknesses of sections of n-butyl methacrylate polymer were determined by ellipsometry, and correlated with the color shown in reflected light. The results are: gray, thinner than 60 mµ; silver, 60 to 90 mµ; gold, 90 to 150 mµ; purple, 150 to 190 mµ; blue, 190 to 240 mµ; green, 240 to 280 mµ; and yellow, 280 to 320 mµ. These results agree well with optical theory and with previous published data for thin films. Sections, after cutting, are 30 to 40 per cent shorter than the face of the block from which they were cut. Only a small improvement results from allowing the sections to remain in the collecting trough at room temperature. Heating above room temperature, however, reduces this shortening, with a corresponding improvement in dimensions and spatial relationships in the sections. When the thickness of the section is considered in interpreting electron micrographs instead of considering the section to be two-dimensional, a more accurate interpretation is possible. The consideration of electron micrographs as arising from projections of many profiles from throughout the whole thickness of the section explains the apparent lack of continuity often observed in serial sections. It is believed that serial sections are actually continuous, but that the change in size of structure through the thickness of one section and the consideration of only the largest profile shown in the micrograph can account for the lack of continuity previously observed. PMID:13549493

  6. An exploration of graph metric reproducibility in complex brain networks

    PubMed Central

    Telesford, Qawi K.; Burdette, Jonathan H.; Laurienti, Paul J.

    2013-01-01

    The application of graph theory to brain networks has become increasingly popular in the neuroimaging community. These investigations and analyses have led to a greater understanding of the brain's complex organization. More importantly, it has become a useful tool for studying the brain under various states and conditions. With the ever expanding popularity of network science in the neuroimaging community, there is increasing interest to validate the measurements and calculations derived from brain networks. Underpinning these studies is the desire to use brain networks in longitudinal studies or as clinical biomarkers to understand changes in the brain. A highly reproducible tool for brain imaging could potentially prove useful as a clinical tool. In this review, we examine recent studies in network reproducibility and their implications for analysis of brain networks. PMID:23717257

  7. Utility, reliability and reproducibility of immunoassay multiplex kits.

    PubMed

    Tighe, Paddy; Negm, Ola; Todd, Ian; Fairclough, Lucy

    2013-05-15

    Multiplex technologies are becoming increasingly important in biomarker studies as they enable patterns of biomolecules to be examined, which provide a more comprehensive depiction of disease than individual biomarkers. They are crucial in deciphering these patterns, but it is essential that they are endorsed for reliability, reproducibility and precision. Here we outline the theoretical basis of a variety of multiplex technologies: Bead-based multiplex immunoassays (i.e. Cytometric Bead Arrays, Luminex™ and Bio-Plex Pro™), microtitre plate-based arrays (i.e. Mesoscale Discovery (MSD) and Quantsys BioSciences QPlex), Slide-based Arrays (i.e. FastQuant™) and reverse phase protein arrays. Their utility, reliability and reproducibility are discussed.

  8. Reproducibility of Mammography Units, Film Processing and Quality Imaging

    NASA Astrophysics Data System (ADS)

    Gaona, Enrique

    2003-09-01

    The purpose of this study was to carry out an exploratory survey of the problems of quality control in mammography and processors units as a diagnosis of the current situation of mammography facilities. Measurements of reproducibility, optical density, optical difference and gamma index are included. Breast cancer is the most frequently diagnosed cancer and is the second leading cause of cancer death among women in the Mexican Republic. Mammography is a radiographic examination specially designed for detecting breast pathology. We found that the problems of reproducibility of AEC are smaller than the problems of processors units because almost all processors fall outside of the acceptable variation limits and they can affect the mammography quality image and the dose to breast. Only four mammography units agree with the minimum score established by ACR and FDA for the phantom image.

  9. jicbioimage: a tool for automated and reproducible bioimage analysis

    PubMed Central

    Hartley, Matthew

    2016-01-01

    There has been steady improvement in methods for capturing bioimages. However analysing these images still remains a challenge. The Python programming language provides a powerful and flexible environment for scientific computation. It has a wide range of supporting libraries for image processing but lacks native support for common bioimage formats, and requires specific code to be written to ensure that suitable audit trails are generated and analyses are reproducible. Here we describe the development of a Python tool that: (1) allows users to quickly view and explore microscopy data; (2) generate reproducible analyses, encoding a complete history of image transformations from raw data to final result; and (3) scale up analyses from initial exploration to high throughput processing pipelines, with a minimal amount of extra effort. The tool, jicbioimage, is open source and freely available online at http://jicbioimage.readthedocs.io. PMID:27896026

  10. Reproducible analyses of microbial food for advanced life support systems

    NASA Technical Reports Server (NTRS)

    Petersen, Gene R.

    1988-01-01

    The use of yeasts in controlled ecological life support systems (CELSS) for microbial food regeneration in space required the accurate and reproducible analysis of intracellular carbohydrate and protein levels. The reproducible analysis of glycogen was a key element in estimating overall content of edibles in candidate yeast strains. Typical analytical methods for estimating glycogen in Saccharomyces were not found to be entirely aplicable to other candidate strains. Rigorous cell lysis coupled with acid/base fractionation followed by specific enzymatic glycogen analyses were required to obtain accurate results in two strains of Candida. A profile of edible fractions of these strains was then determined. The suitability of yeasts as food sources in CELSS food production processes is discussed.

  11. Reproducibility Issues: Avoiding Pitfalls in Animal Inflammation Models.

    PubMed

    Laman, Jon D; Kooistra, Susanne M; Clausen, Björn E

    2017-01-01

    In light of an enhanced awareness of ethical questions and ever increasing costs when working with animals in biomedical research, there is a dedicated and sometimes fierce debate concerning the (lack of) reproducibility of animal models and their relevance for human inflammatory diseases. Despite evident advancements in searching for alternatives, that is, replacing, reducing, and refining animal experiments-the three R's of Russel and Burch (1959)-understanding the complex interactions of the cells of the immune system, the nervous system and the affected tissue/organ during inflammation critically relies on in vivo models. Consequently, scientific advancement and ultimately novel therapeutic interventions depend on improving the reproducibility of animal inflammation models. As a prelude to the remaining hands-on protocols described in this volume, here, we summarize potential pitfalls of preclinical animal research and provide resources and background reading on how to avoid them.

  12. Data Sharing and Reproducible Clinical Genetic Testing: Successes and Challenges

    PubMed Central

    Yang, Shan; Cline, Melissa; Zhang, Can; Paten, Benedict; Lincoln, Stephen e.

    2016-01-01

    Open sharing of clinical genetic data promises to both monitor and eventually improve the reproducibility of variant interpretation among clinical testing laboratories. A significant public data resource has been developed by the NIH ClinVar initiative, which includes submissions from hundreds of laboratories and clinics worldwide. We analyzed a subset of ClinVar data focused on specific clinical areas and we find high reproducibility (>90% concordance) among labs, although challenges for the community are clearly identified in this dataset. We further review results for the commonly tested BRCA1 and BRCA2 genes, which show even higher concordance, although the significant fragmentation of data into different silos presents an ongoing challenge now being addressed by the BRCA Exchange. We encourage all laboratories and clinics to contribute to these important resources. PMID:27896972

  13. jicbioimage: a tool for automated and reproducible bioimage analysis.

    PubMed

    Olsson, Tjelvar S G; Hartley, Matthew

    2016-01-01

    There has been steady improvement in methods for capturing bioimages. However analysing these images still remains a challenge. The Python programming language provides a powerful and flexible environment for scientific computation. It has a wide range of supporting libraries for image processing but lacks native support for common bioimage formats, and requires specific code to be written to ensure that suitable audit trails are generated and analyses are reproducible. Here we describe the development of a Python tool that: (1) allows users to quickly view and explore microscopy data; (2) generate reproducible analyses, encoding a complete history of image transformations from raw data to final result; and (3) scale up analyses from initial exploration to high throughput processing pipelines, with a minimal amount of extra effort. The tool, jicbioimage, is open source and freely available online at http://jicbioimage.readthedocs.io.

  14. Properties of galaxies reproduced by a hydrodynamic simulation.

    PubMed

    Vogelsberger, M; Genel, S; Springel, V; Torrey, P; Sijacki, D; Xu, D; Snyder, G; Bird, S; Nelson, D; Hernquist, L

    2014-05-08

    Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the 'metal' and hydrogen content of galaxies on small scales.

  15. Implementation of a portable and reproducible parallel pseudorandom number generator

    SciTech Connect

    Pryor, D.V.; Cuccaro, S.A.; Mascagni, M.; Robinson, M.L.

    1994-12-31

    The authors describe in detail the parallel implementation of a family of additive lagged-Fibonacci pseudorandom number generators. The theoretical structure of these generators is exploited to preserve their well-known randomness properties and to provide a parallel system in of distinct cycles. The algorithm presented here solves the reproducibility problem for a far larger class of parallel Monte Carlo applications than has been previously possible. In particular, Monte Carlo applications that undergo ``splitting`` can be coded to be reproducible, independent both of the number of processors and the execution order of the parallel processes. A library of portable C routines (available from the authors) that implements these ideas is also described.

  16. Interobserver reproducibility of radiographic evaluation of lumbar spine instability

    PubMed Central

    Segundo, Saulo de Tarso de Sá Pereira; Valesin, Edgar Santiago; Lenza, Mario; Santos, Durval do Carmo Barros; Rosemberg, Laercio Alberto; Ferretti, Mario

    2016-01-01

    ABSTRACT Objective: To measure the interobserver reproducibility of the radiographic evaluation of lumbar spine instability. Methods: Measurements of the dynamic radiographs of the lumbar spine in lateral view were performed, evaluating the anterior translation and the angulation among the vertebral bodies. The tests were evaluated at workstations of the organization, through the Carestream Health Vue RIS (PACS), version 11.0.12.14 Inc. 2009© system. Results: Agreement in detecting cases of radiographic instability among the observers varied from 88.1 to 94.4%, and the agreement coefficients AC1 were all above 0.8, indicating excellent agreement. Conclusion: The interobserver analysis performed among orthopedic surgeons with different levels of training in dynamic radiographs of the spine obtained high reproducibility and agreement. However, some factors, such as the manual method of measurement and the presence of vertebral osteophytes, might have generated a few less accurate results in this comparative evaluation of measurements. PMID:27759827

  17. Empowering Multi-Cohort Gene Expression Analysis to Increase Reproducibility

    PubMed Central

    Haynes, Winston A; Vallania, Francesco; Liu, Charles; Bongen, Erika; Tomczak, Aurelie; Andres-Terrè, Marta; Lofgren, Shane; Tam, Andrew; Deisseroth, Cole A; Li, Matthew D; Sweeney, Timothy E

    2016-01-01

    A major contributor to the scientific reproducibility crisis has been that the results from homogeneous, single-center studies do not generalize to heterogeneous, real world populations. Multi-cohort gene expression analysis has helped to increase reproducibility by aggregating data from diverse populations into a single analysis. To make the multi-cohort analysis process more feasible, we have assembled an analysis pipeline which implements rigorously studied meta-analysis best practices. We have compiled and made publicly available the results of our own multi-cohort gene expression analysis of 103 diseases, spanning 615 studies and 36,915 samples, through a novel and interactive web application. As a result, we have made both the process of and the results from multi-cohort gene expression analysis more approachable for non-technical users. PMID:27896970

  18. MASSIVE DATA, THE DIGITIZATION OF SCIENCE, AND REPRODUCIBILITY OF RESULTS

    ScienceCinema

    None

    2016-07-12

    As the scientific enterprise becomes increasingly computational and data-driven, the nature of the information communicated must change. Without inclusion of the code and data with published computational results, we are engendering a credibility crisis in science. Controversies such as ClimateGate, the microarray-based drug sensitivity clinical trials under investigation at Duke University, and retractions from prominent journals due to unverified code suggest the need for greater transparency in our computational science. In this talk I argue that the scientific method be restored to (1) a focus on error control as central to scientific communication and (2) complete communication of the underlying methodology producing the results, ie. reproducibility. I outline barriers to these goals based on recent survey work (Stodden 2010), and suggest solutions such as the “Reproducible Research Standard” (Stodden 2009), giving open licensing options designed to create an intellectual property framework for scientists consonant with longstanding scientific norms.

  19. Thin EFG octagons

    NASA Astrophysics Data System (ADS)

    Kalejs, J. P.

    1994-03-01

    This report describes work to advance the manufacturing line capabilities in crystal growth and laser cutting of Mobil Solar's unique edge-defined film-fed growth (EFG) octagon technology and to reduce the manufacturing costs of 10 cm x 10 cm polycrystalline silicon EFG wafers. The report summarizes the significant technical improvements in EFG technology achieved in the first 6 months of the PVMaT Phase 2 and the success in meeting program milestones. Technical results are reported for each of the three main pregrain areas: Task 5 -- Thin octagon growth (crystal growth) to reduce the thickness of the octagon to 200 microns; Task 6 -- Laser cutting-to improve the laser cutting process so as to produce wafers with decreased laser cutting damage at increased wafer throughput rates; and Task 7 -- Process control and product specification to implement advanced strategies in crystal growth process control and productivity designed to increase wafer yields.

  20. Reproducibility of graph metrics of human brain structural networks.

    PubMed

    Duda, Jeffrey T; Cook, Philip A; Gee, James C

    2014-01-01

    Recent interest in human brain connectivity has led to the application of graph theoretical analysis to human brain structural networks, in particular white matter connectivity inferred from diffusion imaging and fiber tractography. While these methods have been used to study a variety of patient populations, there has been less examination of the reproducibility of these methods. A number of tractography algorithms exist and many of these are known to be sensitive to user-selected parameters. The methods used to derive a connectivity matrix from fiber tractography output may also influence the resulting graph metrics. Here we examine how these algorithm and parameter choices influence the reproducibility of proposed graph metrics on a publicly available test-retest dataset consisting of 21 healthy adults. The dice coefficient is used to examine topological similarity of constant density subgraphs both within and between subjects. Seven graph metrics are examined here: mean clustering coefficient, characteristic path length, largest connected component size, assortativity, global efficiency, local efficiency, and rich club coefficient. The reproducibility of these network summary measures is examined using the intraclass correlation coefficient (ICC). Graph curves are created by treating the graph metrics as functions of a parameter such as graph density. Functional data analysis techniques are used to examine differences in graph measures that result from the choice of fiber tracking algorithm. The graph metrics consistently showed good levels of reproducibility as measured with ICC, with the exception of some instability at low graph density levels. The global and local efficiency measures were the most robust to the choice of fiber tracking algorithm.

  1. Composting in small laboratory pilots: performance and reproducibility.

    PubMed

    Lashermes, G; Barriuso, E; Le Villio-Poitrenaud, M; Houot, S

    2012-02-01

    Small-scale reactors (<10 l) have been employed in composting research, but few attempts have assessed the performance of composting considering the transformations of organic matter. Moreover, composting at small scales is often performed by imposing a fixed temperature, thus creating artificial conditions, and the reproducibility of composting has rarely been reported. The objectives of this study are to design an innovative small-scale composting device safeguarding self-heating to drive the composting process and to assess the performance and reproducibility of composting in small-scale pilots. The experimental setup included six 4-l reactors used for composting a mixture of sewage sludge and green wastes. The performance of the process was assessed by monitoring the temperature, O(2) consumption and CO(2) emissions, and characterising the biochemical evolution of organic matter. A good reproducibility was found for the six replicates with coefficients of variation for all parameters generally lower than 19%. An intense self-heating ensured the existence of a spontaneous thermophilic phase in all reactors. The average loss of total organic matter (TOM) was 46% of the initial content. Compared to the initial mixture, the hot water soluble fraction decreased by 62%, the hemicellulose-like fraction by 68%, the cellulose-like fraction by 50% and the lignin-like fractions by 12% in the final compost. The TOM losses, compost stabilisation and evolution of the biochemical fractions were similar to observed in large reactors or on-site experiments, excluding the lignin degradation, which was less important than in full-scale systems. The reproducibility of the process and the quality of the final compost make it possible to propose the use of this experimental device for research requiring a mass reduction of the initial composted waste mixtures.

  2. Highly reproducible Bragg grating acousto-ultrasonic contact transducers

    NASA Astrophysics Data System (ADS)

    Saxena, Indu Fiesler; Guzman, Narciso; Lieberman, Robert A.

    2014-09-01

    Fiber optic acousto-ultrasonic transducers offer numerous applications as embedded sensors for impact and damage detection in industrial and aerospace applications as well as non-destructive evaluation. Superficial contact transducers with a sheet of fiber optic Bragg gratings has been demonstrated for guided wave ultrasound based measurements. It is reported here that this method of measurement provides highly reproducible guided ultrasound data of the test composite component, despite the optical fiber transducers not being permanently embedded in it.

  3. How reproducible are the measurements of leaf fluctuating asymmetry?

    PubMed Central

    2015-01-01

    Fluctuating asymmetry (FA) represents small, non-directional deviations from perfect symmetry in morphological characters. FA is generally assumed to increase in response to stress; therefore, FA is frequently used in ecological studies as an index of environmental or genetic stress experienced by an organism. The values of FA are usually small, and therefore the reliable detection of FA requires precise measurements. The reproducibility of fluctuating asymmetry (FA) was explored by comparing the results of measurements of scanned images of 100 leaves of downy birch (Betula pubescens) conducted by 31 volunteer scientists experienced in studying plant FA. The median values of FA varied significantly among the participants, from 0.000 to 0.074, and the coefficients of variation in FA for individual leaves ranged from 25% to 179%. The overall reproducibility of the results among the participants was rather low (0.074). Variation in instruments and methods used by the participants had little effect on the reported FA values, but the reproducibility of the measurements increased by 30% following exclusion of data provided by seven participants who had modified the suggested protocol for leaf measurements. The scientists working with plant FA are advised to pay utmost attention to adequate and detailed description of their data acquisition protocols in their forthcoming publications, because all characteristics of instruments and methods need to be controlled to increase the quality and reproducibility of the data. Whenever possible, the images of all measured objects and the results of primary measurements should be published as electronic appendices to scientific papers. PMID:26157612

  4. How reproducible are the measurements of leaf fluctuating asymmetry?

    PubMed

    Kozlov, Mikhail V

    2015-01-01

    Fluctuating asymmetry (FA) represents small, non-directional deviations from perfect symmetry in morphological characters. FA is generally assumed to increase in response to stress; therefore, FA is frequently used in ecological studies as an index of environmental or genetic stress experienced by an organism. The values of FA are usually small, and therefore the reliable detection of FA requires precise measurements. The reproducibility of fluctuating asymmetry (FA) was explored by comparing the results of measurements of scanned images of 100 leaves of downy birch (Betula pubescens) conducted by 31 volunteer scientists experienced in studying plant FA. The median values of FA varied significantly among the participants, from 0.000 to 0.074, and the coefficients of variation in FA for individual leaves ranged from 25% to 179%. The overall reproducibility of the results among the participants was rather low (0.074). Variation in instruments and methods used by the participants had little effect on the reported FA values, but the reproducibility of the measurements increased by 30% following exclusion of data provided by seven participants who had modified the suggested protocol for leaf measurements. The scientists working with plant FA are advised to pay utmost attention to adequate and detailed description of their data acquisition protocols in their forthcoming publications, because all characteristics of instruments and methods need to be controlled to increase the quality and reproducibility of the data. Whenever possible, the images of all measured objects and the results of primary measurements should be published as electronic appendices to scientific papers.

  5. Icy: an open bioimage informatics platform for extended reproducible research.

    PubMed

    de Chaumont, Fabrice; Dallongeville, Stéphane; Chenouard, Nicolas; Hervé, Nicolas; Pop, Sorin; Provoost, Thomas; Meas-Yedid, Vannary; Pankajakshan, Praveen; Lecomte, Timothée; Le Montagner, Yoann; Lagache, Thibault; Dufour, Alexandre; Olivo-Marin, Jean-Christophe

    2012-06-28

    Current research in biology uses evermore complex computational and imaging tools. Here we describe Icy, a collaborative bioimage informatics platform that combines a community website for contributing and sharing tools and material, and software with a high-end visual programming framework for seamless development of sophisticated imaging workflows. Icy extends the reproducible research principles, by encouraging and facilitating the reusability, modularity, standardization and management of algorithms and protocols. Icy is free, open-source and available at http://icy.bioimageanalysis.org/.

  6. Motivations for dieting: Drive for Thinness is different from Drive for Objective Thinness.

    PubMed

    Chernyak, Yelena; Lowe, Michael R

    2010-05-01

    Drive for thinness is a cardinal feature of bulimia nervosa. However, the widely used Drive for Thinness (DFT) subscale of the Eating Disorder Inventory (Garner, 2004; Garner, Olmstead, & Polivy, 1983) appears to measure a desire to be thinner, not a desire to be objectively thin. We developed the Drive for Objective Thinness (DFOT) Scale and compared unrestrained and restrained eaters and those with bulimia nervosa on the DFT subscale, Goldfarb's Fear of Fat Scale (GFFS; Goldfarb, Dykens, & Gerrard, 1983), and the DFOT Scale. Restrained eaters had higher scores than unrestrained eaters on the DFT subscale and the GFFS, but both groups had low scores on the DFOT Scale. Only the group with bulimia nervosa showed elevated scores on the DFOT Scale. We conclude that restrained eaters diet mostly to avoid weight gain, that individuals with bulimia nervosa diet to achieve thinness and avoid fatness, and that the drive for objective thinness is a unique feature of bulimia nervosa.

  7. CRKSPH - A Conservative Reproducing Kernel Smoothed Particle Hydrodynamics Scheme

    NASA Astrophysics Data System (ADS)

    Frontiere, Nicholas; Raskin, Cody D.; Owen, J. Michael

    2017-03-01

    We present a formulation of smoothed particle hydrodynamics (SPH) that utilizes a first-order consistent reproducing kernel, a smoothing function that exactly interpolates linear fields with particle tracers. Previous formulations using reproducing kernel (RK) interpolation have had difficulties maintaining conservation of momentum due to the fact the RK kernels are not, in general, spatially symmetric. Here, we utilize a reformulation of the fluid equations such that mass, linear momentum, and energy are all rigorously conserved without any assumption about kernel symmetries, while additionally maintaining approximate angular momentum conservation. Our approach starts from a rigorously consistent interpolation theory, where we derive the evolution equations to enforce the appropriate conservation properties, at the sacrifice of full consistency in the momentum equation. Additionally, by exploiting the increased accuracy of the RK method's gradient, we formulate a simple limiter for the artificial viscosity that reduces the excess diffusion normally incurred by the ordinary SPH artificial viscosity. Collectively, we call our suite of modifications to the traditional SPH scheme Conservative Reproducing Kernel SPH, or CRKSPH. CRKSPH retains many benefits of traditional SPH methods (such as preserving Galilean invariance and manifest conservation of mass, momentum, and energy) while improving on many of the shortcomings of SPH, particularly the overly aggressive artificial viscosity and zeroth-order inaccuracy. We compare CRKSPH to two different modern SPH formulations (pressure based SPH and compatibly differenced SPH), demonstrating the advantages of our new formulation when modeling fluid mixing, strong shock, and adiabatic phenomena.

  8. Dosimetric algorithm to reproduce isodose curves obtained from a LINAC.

    PubMed

    Estrada Espinosa, Julio Cesar; Martínez Ovalle, Segundo Agustín; Pereira Benavides, Cinthia Kotzian

    2014-01-01

    In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18 MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18 MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo.

  9. Dosimetric Algorithm to Reproduce Isodose Curves Obtained from a LINAC

    PubMed Central

    Estrada Espinosa, Julio Cesar; Martínez Ovalle, Segundo Agustín; Pereira Benavides, Cinthia Kotzian

    2014-01-01

    In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18 MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18 MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo. PMID:25045398

  10. Reproducibility of SELDI Spectra Across Time and Laboratories

    PubMed Central

    Diao, Lixia; Clarke, Charlotte H.; Coombes, Kevin R.; Hamilton, Stanley R.; Roth, Jack; Mao, Li; Czerniak, Bogdan; Baggerly, Keith A.; Morris, Jeffrey S.; Fung, Eric T.; Bast, Robert C.

    2011-01-01

    This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. The reproducibility of mass spectrometry (MS) data collected using surface enhanced laser desorption/ionization-time of flight (SELDI-TOF) has been questioned. This investigation was designed to test the reproducibility of SELDI data collected over time by multiple users and instruments. Five laboratories prepared arrays once every week for six weeks. Spectra were collected on separate instruments in the individual laboratories. Additionally, all of the arrays produced each week were rescanned on a single instrument in one laboratory. Lab-to-lab and array-to-array variability in alignment parameters were larger than the variability attributable to running samples during different weeks. The coefficient of variance (CV) in spectrum intensity ranged from 25% at baseline, to 80% in the matrix noise region, to about 50% during the exponential drop from the maximum matrix noise. Before normalization, the median CV of the peak heights was 72% and reduced to about 20% after normalization. Additionally, for the spectra from a common instrument, the CV ranged from 5% at baseline, to 50% in the matrix noise region, to 20% during the drop from the maximum matrix noise. Normalization reduced the variability in peak heights to about 18%. With proper processing methods, SELDI instruments produce spectra containing large numbers of reproducibly located peaks, with consistent heights. PMID:21552492

  11. A neural mechanism for sensing and reproducing a time interval

    PubMed Central

    Jazayeri, Mehrdad; Shadlen, Michael N.

    2015-01-01

    SUMMARY Timing plays a crucial role in sensorimotor function. The neural mechanisms that enable the brain to flexibly measure and reproduce time intervals are however not known. We recorded neural activity in parietal cortex of monkeys in a time reproduction task. Monkeys were trained to measure and immediately afterwards reproduce different sample intervals. While measuring an interval, neural responses had a nonlinear profile that increased with the duration of the sample interval. Activity was reset during the transition from measurement to production, and was followed by a ramping activity whose slope encoded the previously measured sample interval. We found that firing rates at the end of the measurement epoch were correlated with both the slope of the ramp and the monkey’s corresponding production interval on a trial-by-trial basis. Analysis of response dynamics further linked the rate of change of firing rates in the measurement epoch to the slope of the ramp in the production epoch. These observations suggest that, during time reproduction, an interval is measured prospectively in relation to the desired motor plan to reproduce that interval. PMID:26455307

  12. Reproducing Kernels in Harmonic Spaces and Their Numerical Implementation

    NASA Astrophysics Data System (ADS)

    Nesvadba, Otakar

    2010-05-01

    In harmonic analysis such as the modelling of the Earth's gravity field, the importance of Hilbert's space of harmonic functions with the reproducing kernel is often discussed. Moreover, in case of an unbounded domain given by the exterior of the sphere or an ellipsoid, the reproducing kernel K(x,y) can be expressed analytically by means of closed formulas or by infinite series. Nevertheless, the straightforward numerical implementation of these formulas leads to dozen of problems, which are mostly connected with the floating-point arithmetic and a number representation. The contribution discusses numerical instabilities in K(x,y) and gradK(x,y) that can be overcome by employing elementary functions, in particular expm1 and log1p. Suggested evaluation scheme for reproducing kernels offers uniform formulas within the whole solution domain as well as superior speed and near-perfect accuracy (10-16 for IEC 60559 double-precision numbers) when compared with the straightforward formulas. The formulas can be easily implemented on the majority of computer platforms, especially when C standard library ISO/IEC 9899:1999 is available.

  13. Indomethacin reproducibly induces metamorphosis in Cassiopea xamachana scyphistomae.

    PubMed

    Cabrales-Arellano, Patricia; Islas-Flores, Tania; Thomé, Patricia E; Villanueva, Marco A

    2017-01-01

    Cassiopea xamachana jellyfish are an attractive model system to study metamorphosis and/or cnidarian-dinoflagellate symbiosis due to the ease of cultivation of their planula larvae and scyphistomae through their asexual cycle, in which the latter can bud new larvae and continue the cycle without differentiation into ephyrae. Then, a subsequent induction of metamorphosis and full differentiation into ephyrae is believed to occur when the symbionts are acquired by the scyphistomae. Although strobilation induction and differentiation into ephyrae can be accomplished in various ways, a controlled, reproducible metamorphosis induction has not been reported. Such controlled metamorphosis induction is necessary for an ensured synchronicity and reproducibility of biological, biochemical, and molecular analyses. For this purpose, we tested if differentiation could be pharmacologically stimulated as in Aurelia aurita, by the metamorphic inducers thyroxine, KI, NaI, Lugol's iodine, H2O2, indomethacin, or retinol. We found reproducibly induced strobilation by 50 μM indomethacin after six days of exposure, and 10-25 μM after 7 days. Strobilation under optimal conditions reached 80-100% with subsequent ephyrae release after exposure. Thyroxine yielded inconsistent results as it caused strobilation occasionally, while all other chemicals had no effect. Thus, indomethacin can be used as a convenient tool for assessment of biological phenomena through a controlled metamorphic process in C. xamachana scyphistomae.

  14. Endoscopic Evaluation of Adenoids: Reproducibility Analysis of Current Methods

    PubMed Central

    Hermann, Juliana Sato; Sallum, Ana Carolina; Pignatari, Shirley Shizue Nagata

    2013-01-01

    Objectives To investigate intra- and interexaminers' reproducibility of usual adenoid hypertrophy assessment methods, according to nasofiberendoscopic examination. Methods Forty children of both sexes, ages ranging between 4 and 14 years, presenting with nasal obstruction and oral breathing suspected to be caused by adenoid hypertrophy, were enrolled in this study. Patients were evaluated by nasofiberendoscopy, and records were referred to and evaluated by two experienced otolaryngologists. Examiners analysed the records according to different evaluation methods; i.e., estimated, and measured percentage of choanal occlusion; as well as subjective and objective classificatory systems of adenoid hypertrophy. Results Data disclosed excellent intraexaminer reproducibility for both estimated and measured choanal occlusion. analysis revealed lower reproducibility rates of estimated in relation to measured choanal occlusion. Measured choanal occlusion also demonstrated less agreement among evaluations made through the right and left sides of the nasal cavity. Alternatively, intra- and interexaminers reliability analysis revealed higher agreement for subjective than objective classificatory system. Besides, subjective method demonstrated higher agreement than the objective classificatory system, when opposite sides were compared. Conclusion Our results suggest that measured is superior to estimated percentage of choanal occlusion, particularly if employed bilaterally, diminishing the lack of agreement between sides. When adenoid categorization is used instead, the authors recommend subjective rather than objective classificatory system of adenoid hypertrophy. PMID:23526477

  15. Indomethacin reproducibly induces metamorphosis in Cassiopea xamachana scyphistomae

    PubMed Central

    Cabrales-Arellano, Patricia; Islas-Flores, Tania; Thomé, Patricia E.

    2017-01-01

    Cassiopea xamachana jellyfish are an attractive model system to study metamorphosis and/or cnidarian–dinoflagellate symbiosis due to the ease of cultivation of their planula larvae and scyphistomae through their asexual cycle, in which the latter can bud new larvae and continue the cycle without differentiation into ephyrae. Then, a subsequent induction of metamorphosis and full differentiation into ephyrae is believed to occur when the symbionts are acquired by the scyphistomae. Although strobilation induction and differentiation into ephyrae can be accomplished in various ways, a controlled, reproducible metamorphosis induction has not been reported. Such controlled metamorphosis induction is necessary for an ensured synchronicity and reproducibility of biological, biochemical, and molecular analyses. For this purpose, we tested if differentiation could be pharmacologically stimulated as in Aurelia aurita, by the metamorphic inducers thyroxine, KI, NaI, Lugol’s iodine, H2O2, indomethacin, or retinol. We found reproducibly induced strobilation by 50 μM indomethacin after six days of exposure, and 10–25 μM after 7 days. Strobilation under optimal conditions reached 80–100% with subsequent ephyrae release after exposure. Thyroxine yielded inconsistent results as it caused strobilation occasionally, while all other chemicals had no effect. Thus, indomethacin can be used as a convenient tool for assessment of biological phenomena through a controlled metamorphic process in C. xamachana scyphistomae. PMID:28265497

  16. Reproducibility of LCA models of crude oil production.

    PubMed

    Vafi, Kourosh; Brandt, Adam R

    2014-11-04

    Scientific models are ideally reproducible, with results that converge despite varying methods. In practice, divergence between models often remains due to varied assumptions, incompleteness, or simply because of avoidable flaws. We examine LCA greenhouse gas (GHG) emissions models to test the reproducibility of their estimates for well-to-refinery inlet gate (WTR) GHG emissions. We use the Oil Production Greenhouse gas Emissions Estimator (OPGEE), an open source engineering-based life cycle assessment (LCA) model, as the reference model for this analysis. We study seven previous studies based on six models. We examine the reproducibility of prior results by successive experiments that align model assumptions and boundaries. The root-mean-square error (RMSE) between results varies between ∼1 and 8 g CO2 eq/MJ LHV when model inputs are not aligned. After model alignment, RMSE generally decreases only slightly. The proprietary nature of some of the models hinders explanations for divergence between the results. Because verification of the results of LCA GHG emissions is often not possible by direct measurement, we recommend the development of open source models for use in energy policy. Such practice will lead to iterative scientific review, improvement of models, and more reliable understanding of emissions.

  17. Establishing a reproducible protocol for measuring index active extension strength.

    PubMed

    Matter-Parrat, V; Hidalgo Diaz, J J; Collon, S; Salazar Botero, S; Prunières, G; Ichihara, S; Facca, S; Liverneaux, P

    2017-02-01

    The goal of this study was to establish a reproducible protocol to measure active extension strength in the index finger. The secondary objectives consisted in correlating the independent or associated index extension strength to the other fingers force of contraction of the extensor indicis propius with hand dominance. The population studied consisted of 24 healthy volunteers, including 19 women and 20 right-handed individuals. The independent and dependent index extension strength in each hand was measured three times with a dynamometer by three examiners at Day 0 and again at Day 7. Intra and inter-examiner reproducibility were, respectively, >0.90 and >0.75 in all cases. The independent extension strength was lower than the dependent one. There was no difference between the independent index extension strength on the dominant and non-dominant sides. The same was true for the dependent strength. Our results show that our protocol is reproducible in measuring independent and dependent index extension strength. Dominance did not come into account.

  18. Reproducibly estimating and evaluating supraglacial lake depth with Landsat 8 and other multispectral sensors

    NASA Astrophysics Data System (ADS)

    Pope, Allen

    2016-04-01

    Lakes which form on the surface of ice sheets (supraglacial lakes) play an important role in the ice sheet hydrological system, serving as temporary reservoirs for meltwater that can lead to ice fracture and associated ice flow speedups or ice shelf disintegration. Satellite imagery can be used to monitor the extent and volume of supraglacial lakes. In this study, we summarize and expand on methods for doing this that have been optimized for the multispectral imager aboard Landsat 8. This report fully documents the data and software (i.e., MATLAB and GDAL scripts) used in these analyses, linking citeable and freely accessible data (in ACADIS and Figshare) to published figures via shared (GitHub), described (OntoSoft), and citeable (Zenodo) code as described in a full provenance diagram. In addition, new water supraglacial volumes for the Sermeq Kujalleq (Jakobshavn) region for 2015 are presented and compared to results from 2014. Lakes in 2015 largely behaved similarly to 2014, with maxima and minima occurring in recurrent areas; disparate behavior is explained both by aliasing and interannual temperature variability. The challenges of achieving full openness, documentation, and reproducibility are discussed, as well as examples where higher standards of accessibility and provenance would have facilitated the original research. Still, the interdependence of documentation can make accessibility challenging to achieve. However, if best practice is integrated into research processes and workflow, as demonstrated here, it will facilitate more complete and more effective reproducibility and reuse of geoscience methods and results.

  19. Easy fabrication of thin membranes with through holes. Application to protein patterning.

    PubMed

    Masters, Thomas; Engl, Wilfried; Weng, Zhe L; Arasi, Bakya; Gauthier, Nils; Viasnoff, Virgile

    2012-01-01

    Since protein patterning on 2D surfaces has emerged as an important tool in cell biology, the development of easy patterning methods has gained importance in biology labs. In this paper we present a simple, rapid and reliable technique to fabricate thin layers of UV curable polymer with through holes. These membranes are as easy to fabricate as microcontact printing stamps and can be readily used for stencil patterning. We show how this microfabrication scheme allows highly reproducible and highly homogeneous protein patterning with micron sized resolution on surfaces as large as 10 cm(2). Using these stencils, fragile proteins were patterned without loss of function in a fully hydrated state. We further demonstrate how intricate patterns of multiple proteins can be achieved by stacking the stencil membranes. We termed this approach microserigraphy.

  20. Towards a universal product ion mass spectral library - reproducibility of product ion spectra across eleven different mass spectrometers.

    PubMed

    Hopley, Chris; Bristow, Tony; Lubben, Anneke; Simpson, Alec; Bull, Elaine; Klagkou, Katerina; Herniman, Julie; Langley, John

    2008-06-01

    Product ion spectra produced by collision-induced dissociation (CID) in tandem mass spectrometry experiments can differ markedly between instruments. There have been a number of attempts to standardise the production of product ion spectra; however, a consensus on the most appropriate approach to the reproducible production of spectra has yet to be reached. We have previously reported the comparison of product ion spectra on a number of different types of instruments - a triple quadrupole, two ion traps and a Fourier transform ion cyclotron resonance mass spectrometer (Bristow AWT, Webb KS, Lubben AT, Halket JM. Rapid Commun. Mass Spectrom. 2004; 18: 1). The study showed that a high degree of reproducibility was achievable. The goal of this study was to improve the comparability and reproducibility of CID product ion mass spectra produced in different laboratories and using different instruments. This was carried out experimentally by defining a spectral calibration point on each mass spectrometer for product ion formation. The long-term goal is the development of a universal (instrument independent) product ion mass spectral library for the identification of unknowns. The spectra of 48 compounds have been recorded on eleven mass spectrometers: six ion traps, two triple quadrupoles, a hybrid triple quadrupole, and two quadrupole time-of-flight instruments. Initially, 4371 spectral comparisons were carried out using the data from eleven instruments and the degree of reproducibility was evaluated. A blind trial has also been carried out to assess the reproducibility of spectra obtained during LC/MS/MS. The results suggest a degree of reproducibility across all instrument types using the tuning point technique. The reproducibility of the product ion spectra is increased when comparing the tandem in time type instruments and the tandem in space instruments as two separate groups. This may allow the production of a more limited, yet useful, screening library for LC

  1. Thin-film metal coated insulation barrier in a Josephson tunnel junction. [Patent application

    DOEpatents

    Hawkins, G.A.; Clarke, J.

    1975-10-31

    A highly stable, durable, and reproducible Josephson tunnel junction consists of a thin-film electrode of a hard superconductor, a thin oxide insulation layer over the electrode constituting a Josephson tunnel junction barrier, a thin-film layer of stabilizing metal over the barrier, and a second thin-film hard superconductive electrode over the stabilizing film. The thin stabilizing metal film is made only thick enough to limit penetration of the electrode material through the insulation layer so as to prevent a superconductive short.

  2. 'No delays achiever'.

    PubMed

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

  3. Vicarious Achievement Orientation.

    ERIC Educational Resources Information Center

    Leavitt, Harold J.; And Others

    This study tests hypotheses about achievement orientation, particularly vicarious achievement. Undergraduate students (N=437) completed multiple-choice questionnaires, indicating likely responses of one person to the success of another. The sex of succeeder and observer, closeness of relationship, and setting (medical school or graduate school of…

  4. Heritability of Creative Achievement

    ERIC Educational Resources Information Center

    Piffer, Davide; Hur, Yoon-Mi

    2014-01-01

    Although creative achievement is a subject of much attention to lay people, the origin of individual differences in creative accomplishments remain poorly understood. This study examined genetic and environmental influences on creative achievement in an adult sample of 338 twins (mean age = 26.3 years; SD = 6.6 years). Twins completed the Creative…

  5. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  6. Achievement-Based Resourcing.

    ERIC Educational Resources Information Center

    Fletcher, Mike; And Others

    1992-01-01

    This collection of seven articles examines achievement-based resourcing (ABR), the concept that the funding of educational institutions should be linked to their success in promoting student achievement, with a focus on the application of ABR to postsecondary education in the United Kingdom. The articles include: (1) "Introduction" (Mick…

  7. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  8. Venusian Polar Vortex reproduced by a general circulation model

    NASA Astrophysics Data System (ADS)

    Ando, Hiroki; Sugimoto, Norihiko; Takagi, Masahiro

    2016-10-01

    Unlike the polar vortices observed in the Earth, Mars and Titan atmospheres, the observed Venus polar vortex is warmer than the mid-latitudes at cloud-top levels (~65 km). This warm polar vortex is zonally surrounded by a cold latitude band located at ~60 degree latitude, which is a unique feature called 'cold collar' in the Venus atmosphere [e.g. Taylor et al. 1980; Piccioni et al. 2007]. Although these structures have been observed in numerous previous observations, the formation mechanism is still unknown. In addition, an axi-asymmetric feature is always seen in the warm polar vortex. It changes temporally and sometimes shows a hot polar dipole or S-shaped structure as shown by a lot of infrared measurements [e.g. Garate-Lopez et al. 2013; 2015]. However, its vertical structure has not been investigated. To solve these problems, we performed a numerical simulation of the Venus atmospheric circulation using a general circulation model named AFES for Venus [Sugimoto et al. 2014] and reproduced these puzzling features.And then, the reproduced structures of the atmosphere and the axi-asymmetirc feature are compared with some previous observational results.In addition, the quasi-periodical zonal-mean zonal wind fluctuation is also seen in the Venus polar vortex reproduced in our model. This might be able to explain some observational results [e.g. Luz et al. 2007] and implies that the polar vacillation might also occur in the Venus atmosphere, which is silimar to the Earth's polar atmosphere. We will also show some initial results about this point in this presentation.

  9. Validity and Reproducibility of a Spanish Dietary History

    PubMed Central

    Guallar-Castillón, Pilar; Sagardui-Villamor, Jon; Balboa-Castillo, Teresa; Sala-Vila, Aleix; Ariza Astolfi, Mª José; Sarrión Pelous, Mª Dolores; León-Muñoz, Luz María; Graciani, Auxiliadora; Laclaustra, Martín; Benito, Cristina; Banegas, José Ramón; Artalejo, Fernando Rodríguez

    2014-01-01

    Objective To assess the validity and reproducibility of food and nutrient intake estimated with the electronic diet history of ENRICA (DH-E), which collects information on numerous aspects of the Spanish diet. Methods The validity of food and nutrient intake was estimated using Pearson correlation coefficients between the DH-E and the mean of seven 24-hour recalls collected every 2 months over the previous year. The reproducibility was estimated using intraclass correlation coefficients between two DH-E made one year apart. Results The correlations coefficients between the DH-E and the mean of seven 24-hour recalls for the main food groups were cereals (r = 0.66), meat (r = 0.66), fish (r = 0.42), vegetables (r = 0.62) and fruits (r = 0.44). The mean correlation coefficient for all 15 food groups considered was 0.53. The correlations for macronutrients were: energy (r = 0.76), proteins (r = 0.58), lipids (r = 0.73), saturated fat (r = 0.73), monounsaturated fat (r = 0.59), polyunsaturated fat (r = 0.57), and carbohydrates (r = 0.66). The mean correlation coefficient for all 41 nutrients studied was 0.55. The intraclass correlation coefficient between the two DH-E was greater than 0.40 for most foods and nutrients. Conclusions The DH-E shows good validity and reproducibility for estimating usual intake of foods and nutrients. PMID:24465878

  10. Emergence of reproducible spatiotemporal activity during motor learning.

    PubMed

    Peters, Andrew J; Chen, Simon X; Komiyama, Takaki

    2014-06-12

    The motor cortex is capable of reliably driving complex movements yet exhibits considerable plasticity during motor learning. These observations suggest that the fundamental relationship between motor cortex activity and movement may not be fixed but is instead shaped by learning; however, to what extent and how motor learning shapes this relationship are not fully understood. Here we addressed this issue by using in vivo two-photon calcium imaging to monitor the activity of the same population of hundreds of layer 2/3 neurons while mice learned a forelimb lever-press task over two weeks. Excitatory and inhibitory neurons were identified by transgenic labelling. Inhibitory neuron activity was relatively stable and balanced local excitatory neuron activity on a movement-by-movement basis, whereas excitatory neuron activity showed higher dynamism during the initial phase of learning. The dynamics of excitatory neurons during the initial phase involved the expansion of the movement-related population which explored various activity patterns even during similar movements. This was followed by a refinement into a smaller population exhibiting reproducible spatiotemporal sequences of activity. This pattern of activity associated with the learned movement was unique to expert animals and not observed during similar movements made during the naive phase, and the relationship between neuronal activity and individual movements became more consistent with learning. These changes in population activity coincided with a transient increase in dendritic spine turnover in these neurons. Our results indicate that a novel and reproducible activity-movement relationship develops as a result of motor learning, and we speculate that synaptic plasticity within the motor cortex underlies the emergence of reproducible spatiotemporal activity patterns for learned movements. These results underscore the profound influence of learning on the way that the cortex produces movements.

  11. Psychophysiological responses to pain identify reproducible human clusters.

    PubMed

    Farmer, Adam D; Coen, Steven J; Kano, Michiko; Paine, Peter A; Shwahdi, Mustafa; Jafari, Jafar; Kishor, Jessin; Worthen, Sian F; Rossiter, Holly E; Kumari, Veena; Williams, Steven C R; Brammer, Michael; Giampietro, Vincent P; Droney, Joanne; Riley, Julia; Furlong, Paul L; Knowles, Charles H; Lightman, Stafford L; Aziz, Qasim

    2013-11-01

    Pain is a ubiquitous yet highly variable experience. The psychophysiological and genetic factors responsible for this variability remain unresolved. We hypothesised the existence of distinct human pain clusters (PCs) composed of distinct psychophysiological and genetic profiles coupled with differences in the perception and the brain processing of pain. We studied 120 healthy subjects in whom the baseline personality and anxiety traits and the serotonin transporter-linked polymorphic region (5-HTTLPR) genotype were measured. Real-time autonomic nervous system parameters and serum cortisol were measured at baseline and after standardised visceral and somatic pain stimuli. Brain processing reactions to visceral pain were studied in 29 subjects using functional magnetic resonance imaging (fMRI). The reproducibility of the psychophysiological responses to pain was assessed at year. In group analysis, visceral and somatic pain caused an expected increase in sympathetic and cortisol responses and activated the pain matrix according to fMRI studies. However, using cluster analysis, we found 2 reproducible PCs: at baseline, PC1 had higher neuroticism/anxiety scores (P ≤ 0.01); greater sympathetic tone (P<0.05); and higher cortisol levels (P ≤ 0.001). During pain, less stimulus was tolerated (P ≤ 0.01), and there was an increase in parasympathetic tone (P ≤ 0.05). The 5-HTTLPR short allele was over-represented (P ≤ 0.005). PC2 had the converse profile at baseline and during pain. Brain activity differed (P ≤ 0.001); greater activity occurred in the left frontal cortex in PC1, whereas PC2 showed greater activity in the right medial/frontal cortex and right anterior insula. In health, 2 distinct reproducible PCs exist in humans. In the future, PC characterization may help to identify subjects at risk for developing chronic pain and may reduce variability in brain imaging studies.

  12. Brugada phenocopy clinical reproducibility demonstrated by recurrent hypokalemia.

    PubMed

    Genaro, Natalia R; Anselm, Daniel D; Cervino, Nahuel; Estevez, Ariel O; Perona, Carlos; Villamil, Alejandro M; Kervorkian, Ruben; Baranchuk, Adrian

    2014-07-01

    Brugada phenocopies (BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome (BrS). BrP are characterized by type 1 or type 2 Brugada electrocardiogram (ECG) patterns in precordial leads V1 -V3 ; however, BrP are elicited by various underlying clinical conditions such as electrolyte disturbances, myocardial ischemia, or poor ECG filters. In this report, we describe the first case of clinically reproducible BrP which is important to the conceptual evolution of BrP.

  13. INFRARED IMAGING OF CARBON AND CERAMIC COMPOSITES: DATA REPRODUCIBILITY

    SciTech Connect

    Knight, B.; Howard, D. R.; Ringermacher, H. I.; Hudson, L. D.

    2010-02-22

    Infrared NDE techniques have proven to be superior for imaging of flaws in ceramic matrix composites (CMC) and carbon silicon carbide composites (C/SiC). Not only can one obtain accurate depth gauging of flaws such as delaminations and layered porosity in complex-shaped components such as airfoils and other aeronautical components, but also excellent reproducibility of image data is obtainable using the STTOF (Synthetic Thermal Time-of-Flight) methodology. The imaging of large complex shapes is fast and reliable. This methodology as applied to large C/SiC flight components at the NASA Dryden Flight Research Center will be described.

  14. Reproducing continuous radio blackout using glow discharge plasma

    SciTech Connect

    Xie, Kai; Li, Xiaoping; Liu, Donglin; Shao, Mingxu; Zhang, Hanlu

    2013-10-15

    A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 10{sup 9} to 2.5 × 10{sup 11} cm{sup −3}. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths.

  15. Data quality in predictive toxicology: reproducibility of rodent carcinogenicity experiments.

    PubMed Central

    Gottmann, E; Kramer, S; Pfahringer, B; Helma, C

    2001-01-01

    We compared 121 replicate rodent carcinogenicity assays from the two parts (National Cancer Institute/National Toxicology Program and literature) of the Carcinogenic Potency Database (CPDB) to estimate the reliability of these experiments. We estimated a concordance of 57% between the overall rodent carcinogenicity classifications from both sources. This value did not improve substantially when additional biologic information (species, sex, strain, target organs) was considered. These results indicate that rodent carcinogenicity assays are much less reproducible than previously expected, an effect that should be considered in the development of structure-activity relationship models and the risk assessment process. PMID:11401763

  16. Achievability for telerobotic systems

    NASA Astrophysics Data System (ADS)

    Kress, Reid L.; Draper, John V.; Hamel, William R.

    2001-02-01

    Methods are needed to improve the capabilities of autonomous robots to perform tasks that are difficult for contemporary robots, and to identify those tasks that robots cannot perform. Additionally, in the realm of remote handling, methods are needed to assess which tasks and/or subtasks are candidates for automation. We are developing a new approach to understanding the capability of autonomous robotic systems. This approach uses formalized methods for determining the achievability of tasks for robots, that is, the likelihood that an autonomous robot or telerobot can successfully complete a particular task. Any autonomous system may be represented in achievability space by the volume describing that system's capabilities within the 3-axis space delineated by perception, cognition, and action. This volume may be thought of as a probability density with achievability decreasing as the distance from the centroid of the volume increases. Similarly, any task may be represented within achievability space. However, as tasks have more finite requirements for perception, cognition, and action, each may be represented as a point (or, more accurately, as a small sphere) within achievability space. Analysis of achievability can serve to identify, a priori, the survivability of robotic systems and the likelihood of mission success; it can be used to plan a mission or portions of a mission; it can be used to modify a mission plan to accommodate unpredicted occurrences; it can also serve to identify needs for modifications to robotic systems or tasks to improve achievability. .

  17. Novel simple templates for reproducible positioning of skin applicators in brachytherapy

    PubMed Central

    Pérez-Calatayud, Maria Jose; Bautista, Juan Antonio; Carmona, Vicente; Celada, Francisco; Tormo, Alejandro; García-Martinez, Teresa; Richart Sancho, José; Santos Ortega, Manuel; Silla, Magda; Ballester, Facundo; Pérez-Calatayud, Jose

    2016-01-01

    Purpose Esteya and Valencia surface applicators are designed to treat skin tumors using brachytherapy. In clinical practice, in order to avoid errors that may affect the treatment outcome, there are two issues that need to be carefully addressed. First, the selected applicator for the treatment should provide adequate margin for the target, and second, the applicator has to be precisely positioned before each treatment fraction. In this work, we describe the development and use of a new acrylic templates named Template La Fe-ITIC. They have been designed specifically to help the clinical user in the selection of the correct applicator, and to assist the medical staff in reproducing the positioning of the applicator. These templates are freely available upon request. Material and methods Templates that were developed by University and Polytechnic Hospital La Fe (La Fe) and Hospital Clínica Benidorm (ITIC) in cooperation with Elekta, consist of a thin sheet made of transparent acrylic. For each applicator, a crosshair and two different circles are drawn on these templates: the inner one corresponds to the useful beam, while the outer one represents the external perimeter of the applicator. The outer circle contains slits that facilitate to draw a circle on the skin of the patient for exact positioning of the applicator. In addition, there are two perpendicular rulers to define the adequate margin. For each applicator size, a specific template was developed. Results The templates have been used successfully in our institutions for more than 50 patients’ brachytherapy treatments. They are currently being used for Esteya and Valencia applicators. Conclusions The template La Fe-ITIC is simple and practical. It improves both the set-up time and reproducibility. It helps to establish the adequate margins, an essential point in the clinical outcome. PMID:27648089

  18. Percolating silicon nanowire networks with highly reproducible electrical properties.

    PubMed

    Serre, Pauline; Mongillo, Massimo; Periwal, Priyanka; Baron, Thierry; Ternon, Céline

    2015-01-09

    Here, we report the morphological and electrical properties of self-assembled silicon nanowires networks, also called Si nanonets. At the macroscopic scale, the nanonets involve several millions of nanowires. So, the observed properties should result from large scale statistical averaging, minimizing thus the discrepancies that occur from one nanowire to another. Using a standard filtration procedure, the so-obtained Si nanonets are highly reproducible in terms of their morphology, with a Si nanowire density precisely controlled during the nanonet elaboration. In contrast to individual Si nanowires, the electrical properties of Si nanonets are highly consistent, as demonstrated here by the similar electrical properties obtained in hundreds of Si nanonet-based devices. The evolution of the Si nanonet conductance with Si nanowire density demonstrates that Si nanonets behave like standard percolating media despite the presence of numerous nanowire-nanowire intersecting junctions into the nanonets and the native oxide shell surrounding the Si nanowires. Moreover, when silicon oxidation is prevented or controlled, the electrical properties of Si nanonets are stable over many months. As a consequence, Si nanowire-based nanonets constitute a promising flexible material with stable and reproducible electrical properties at the macroscopic scale while being composed of nanoscale components, which confirms the Si nanonet potential for a wide range of applications including flexible electronic, sensing and photovoltaic applications.

  19. Ranking and averaging independent component analysis by reproducibility (RAICAR).

    PubMed

    Yang, Zhi; LaConte, Stephen; Weng, Xuchu; Hu, Xiaoping

    2008-06-01

    Independent component analysis (ICA) is a data-driven approach that has exhibited great utility for functional magnetic resonance imaging (fMRI). Standard ICA implementations, however, do not provide the number and relative importance of the resulting components. In addition, ICA algorithms utilizing gradient-based optimization give decompositions that are dependent on initialization values, which can lead to dramatically different results. In this work, a new method, RAICAR (Ranking and Averaging Independent Component Analysis by Reproducibility), is introduced to address these issues for spatial ICA applied to fMRI. RAICAR utilizes repeated ICA realizations and relies on the reproducibility between them to rank and select components. Different realizations are aligned based on correlations, leading to aligned components. Each component is ranked and thresholded based on between-realization correlations. Furthermore, different realizations of each aligned component are selectively averaged to generate the final estimate of the given component. Reliability and accuracy of this method are demonstrated with both simulated and experimental fMRI data.

  20. Reproducibility of the measurement of sweet taste preferences.

    PubMed

    Asao, Keiko; Luo, Wendy; Herman, William H

    2012-12-01

    Developing interventions to prevent and treat obesity are medical and public health imperatives. Taste is a major determinant of food intake and reliable methods to measure taste preferences need to be established. This study aimed to establish the short-term reproducibility of sweet taste preference measurements using 5-level sucrose concentrations in healthy adult volunteers. We defined sweet taste preference as the geometric mean of the preferred sucrose concentration determined from two series of two-alternative, forced-choice staircase procedures administered 10min apart on a single day. We repeated the same procedures at a second visit 3-7days later. Twenty-six adults (13 men and 13 women, age 33.2±12.2years) completed the measurements. The median number of pairs presented for each series was three (25th and 75th percentiles: 3, 4). The intraclass correlation coefficients between the measurements was 0.82 (95% confidence interval [CI]: 0.63-0.92) within a few days. This study showed high short-term reproducibility of a simple, 5-level procedure for measuring sweet taste preferences. This method may be useful for assessing sweet taste preferences and the risks resulting from those preferences.

  1. Reproducibility of Neonate Ocular Circulation Measurements Using Laser Speckle Flowgraphy

    PubMed Central

    Matsumoto, Tadashi; Itokawa, Takashi; Shiba, Tomoaki; Katayama, Yuji; Arimura, Tetsushi; Mizukaki, Norio; Yoda, Hitoshi; Hori, Yuichi

    2015-01-01

    Measuring the ocular blood flow in neonates may clarify the relationships between eye diseases and ocular circulation abnormalities. However, no method for noninvasively measuring ocular circulation in neonates is established. We used laser speckle flowgraphy (LSFG) modified for neonates to measure their ocular circulation and investigated whether this method is reproducible. During their normal sleep, we studied 16 subjects (adjusted age of 34–48 weeks) whose blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR) values of the optic nerve head (ONH) were obtained: the MBR-A (mean of all values), MBR-V (vessel mean), and MBR-T (tissue mean), and nine blood flow pulse waveform parameters in the ONH were examined. We analyzed the coefficient of variation (COV) and the intraclass correlation coefficient (ICC) for each parameter. The COVs of the MBR values were all ≤10%. The ICCs of the MBR values were all >0.8. Good COVs were observed for the blowout score, blowout time, rising rate, falling rate, and acceleration time index. Although the measurement of ocular circulation in the neonates was difficult, our results exhibited reproducibility, suggesting that this method could be used in clinical research. PMID:26557689

  2. Reproducibility in Nerve Morphometry: Comparison between Methods and among Observers

    PubMed Central

    Bilego Neto, Antônio Paulo da Costa; Silveira, Fernando Braga Cassiano; Rodrigues da Silva, Greice Anne; Sanada, Luciana Sayuri; Fazan, Valéria Paula Sassoli

    2013-01-01

    We investigated the reproducibility of a semiautomated method (computerized with manual intervention) for nerve morphometry (counting and measuring myelinated fibers) between three observers with different levels of expertise and experience with the method. Comparisons between automatic (fully computerized) and semiautomated morphometric methods performed by the same computer software using the same nerve images were also performed. Sural nerves of normal adult rats were used. Automatic and semiautomated morphometry of the myelinated fibers were made through the computer software KS-400. Semiautomated morphometry was conducted by three independent observers on the same images, using the semiautomated method. Automatic morphometry overestimated the myelin sheath area, thus overestimating the myelinated fiber size and underestimating the axon size. Fiber distributions overestimation was of 0.5 μm. For the semiautomated morphometry, no differences were found between observers for myelinated fiber and axon size distributions. Overestimation of the myelin sheath size of normal fibers by the fully automatic method might have an impact when morphometry is used for diagnostic purposes. We suggest that not only semiautomated morphometry results can be compared between different centers in clinical trials but it can also be performed by more than one investigator in one single experiment, being a reliable and reproducible method. PMID:23841086

  3. Assessment of Modeling Capability for Reproducing Storm Impacts on TEC

    NASA Astrophysics Data System (ADS)

    Shim, J. S.; Kuznetsova, M. M.; Rastaetter, L.; Bilitza, D.; Codrescu, M.; Coster, A. J.; Emery, B. A.; Foerster, M.; Foster, B.; Fuller-Rowell, T. J.; Huba, J. D.; Goncharenko, L. P.; Mannucci, A. J.; Namgaladze, A. A.; Pi, X.; Prokhorov, B. E.; Ridley, A. J.; Scherliess, L.; Schunk, R. W.; Sojka, J. J.; Zhu, L.

    2014-12-01

    During geomagnetic storm, the energy transfer from solar wind to magnetosphere-ionosphere system adversely affects the communication and navigation systems. Quantifying storm impacts on TEC (Total Electron Content) and assessment of modeling capability of reproducing storm impacts on TEC are of importance to specifying and forecasting space weather. In order to quantify storm impacts on TEC, we considered several parameters: TEC changes compared to quiet time (the day before storm), TEC difference between 24-hour intervals, and maximum increase/decrease during the storm. We investigated the spatial and temporal variations of the parameters during the 2006 AGU storm event (14-15 Dec. 2006) using ground-based GPS TEC measurements in the selected 5 degree eight longitude sectors. The latitudinal variations were also studied in two longitude sectors among the eight sectors where data coverage is relatively better. We obtained modeled TEC from various ionosphere/thermosphere (IT) models. The parameters from the models were compared with each other and with the observed values. We quantified performance of the models in reproducing the TEC variations during the storm using skill scores. This study has been supported by the Community Coordinated Modeling Center (CCMC) at the Goddard Space Flight Center. Model outputs and observational data used for the study will be permanently posted at the CCMC website (http://ccmc.gsfc.nasa.gov) for the space science communities to use.

  4. Reproducible quantitative proteotype data matrices for systems biology

    PubMed Central

    Röst, Hannes L.; Malmström, Lars; Aebersold, Ruedi

    2015-01-01

    Historically, many mass spectrometry–based proteomic studies have aimed at compiling an inventory of protein compounds present in a biological sample, with the long-term objective of creating a proteome map of a species. However, to answer fundamental questions about the behavior of biological systems at the protein level, accurate and unbiased quantitative data are required in addition to a list of all protein components. Fueled by advances in mass spectrometry, the proteomics field has thus recently shifted focus toward the reproducible quantification of proteins across a large number of biological samples. This provides the foundation to move away from pure enumeration of identified proteins toward quantitative matrices of many proteins measured across multiple samples. It is argued here that data matrices consisting of highly reproducible, quantitative, and unbiased proteomic measurements across a high number of conditions, referred to here as quantitative proteotype maps, will become the fundamental currency in the field and provide the starting point for downstream biological analysis. Such proteotype data matrices, for example, are generated by the measurement of large patient cohorts, time series, or multiple experimental perturbations. They are expected to have a large effect on systems biology and personalized medicine approaches that investigate the dynamic behavior of biological systems across multiple perturbations, time points, and individuals. PMID:26543201

  5. Reproducible Research Practices and Transparency across the Biomedical Literature

    PubMed Central

    Khoury, Muin J.; Schully, Sheri D.; Ioannidis, John P. A.

    2016-01-01

    There is a growing movement to encourage reproducibility and transparency practices in the scientific community, including public access to raw data and protocols, the conduct of replication studies, systematic integration of evidence in systematic reviews, and the documentation of funding and potential conflicts of interest. In this survey, we assessed the current status of reproducibility and transparency addressing these indicators in a random sample of 441 biomedical journal articles published in 2000–2014. Only one study provided a full protocol and none made all raw data directly available. Replication studies were rare (n = 4), and only 16 studies had their data included in a subsequent systematic review or meta-analysis. The majority of studies did not mention anything about funding or conflicts of interest. The percentage of articles with no statement of conflict decreased substantially between 2000 and 2014 (94.4% in 2000 to 34.6% in 2014); the percentage of articles reporting statements of conflicts (0% in 2000, 15.4% in 2014) or no conflicts (5.6% in 2000, 50.0% in 2014) increased. Articles published in journals in the clinical medicine category versus other fields were almost twice as likely to not include any information on funding and to have private funding. This study provides baseline data to compare future progress in improving these indicators in the scientific literature. PMID:26726926

  6. Reproducibility of Variant Calls in Replicate Next Generation Sequencing Experiments

    PubMed Central

    Qi, Yuan; Liu, Xiuping; Liu, Chang-gong; Wang, Bailing; Hess, Kenneth R.; Symmans, W. Fraser; Shi, Weiwei; Pusztai, Lajos

    2015-01-01

    Nucleotide alterations detected by next generation sequencing are not always true biological changes but could represent sequencing errors. Even highly accurate methods can yield substantial error rates when applied to millions of nucleotides. In this study, we examined the reproducibility of nucleotide variant calls in replicate sequencing experiments of the same genomic DNA. We performed targeted sequencing of all known human protein kinase genes (kinome) (~3.2 Mb) using the SOLiD v4 platform. Seventeen breast cancer samples were sequenced in duplicate (n=14) or triplicate (n=3) to assess concordance of all calls and single nucleotide variant (SNV) calls. The concordance rates over the entire sequenced region were >99.99%, while the concordance rates for SNVs were 54.3-75.5%. There was substantial variation in basic sequencing metrics from experiment to experiment. The type of nucleotide substitution and genomic location of the variant had little impact on concordance but concordance increased with coverage level, variant allele count (VAC), variant allele frequency (VAF), variant allele quality and p-value of SNV-call. The most important determinants of concordance were VAC and VAF. Even using the highest stringency of QC metrics the reproducibility of SNV calls was around 80% suggesting that erroneous variant calling can be as high as 20-40% in a single experiment. The sequence data have been deposited into the European Genome-phenome Archive (EGA) with accession number EGAS00001000826. PMID:26136146

  7. [Study of the validity and reproducibility of passive ozone monitors].

    PubMed

    Cortez-Lugo, M; Romieu, I; Palazuelos-Rendón, E; Hernández-Avila, M

    1995-01-01

    The aim of this study was to evaluate the validity and reproducibility between ozone measurements obtained with passive ozone monitors and those registered with a continuous ozone monitor, to determine the applicability of passive monitors in epidemiological research. The study was carried out during November and December 1992. Indoor and outdoor classroom air ozone concentrations were analyzed using 28 passive monitors and using a continuous monitor. The correlation between both measurements was highly significant (r = 0.089, p < 0.001), indicating a very good validity. Also, the correlation between the measurements obtained with two different passive monitors exposed concurrently was very high (r = 0.97, p < 0.001), indicating a good reproducibility in the measurements of the passive monitors. The relative error between the concentrations measured by the passive monitors and those from the continuous monitor tended to decrease with increasing ozone concentrations. The results suggest that passive monitors should be used to determine cumulative exposure of ozone exceeding 100 ppb, corresponding to an exposure period greater than five days, if used to analyze indoor air.

  8. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns

    PubMed Central

    Cruchet, Steeve; Gustafson, Kyle; Benton, Richard; Floreano, Dario

    2015-01-01

    The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs—locomotor bouts—matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior. PMID:26600381

  9. A Bayesian Perspective on the Reproducibility Project: Psychology.

    PubMed

    Etz, Alexander; Vandekerckhove, Joachim

    2016-01-01

    We revisit the results of the recent Reproducibility Project: Psychology by the Open Science Collaboration. We compute Bayes factors-a quantity that can be used to express comparative evidence for an hypothesis but also for the null hypothesis-for a large subset (N = 72) of the original papers and their corresponding replication attempts. In our computation, we take into account the likely scenario that publication bias had distorted the originally published results. Overall, 75% of studies gave qualitatively similar results in terms of the amount of evidence provided. However, the evidence was often weak (i.e., Bayes factor < 10). The majority of the studies (64%) did not provide strong evidence for either the null or the alternative hypothesis in either the original or the replication, and no replication attempts provided strong evidence in favor of the null. In all cases where the original paper provided strong evidence but the replication did not (15%), the sample size in the replication was smaller than the original. Where the replication provided strong evidence but the original did not (10%), the replication sample size was larger. We conclude that the apparent failure of the Reproducibility Project to replicate many target effects can be adequately explained by overestimation of effect sizes (or overestimation of evidence against the null hypothesis) due to small sample sizes and publication bias in the psychological literature. We further conclude that traditional sample sizes are insufficient and that a more widespread adoption of Bayesian methods is desirable.

  10. Data reproducibility of pace strategy in a laboratory test run

    PubMed Central

    de França, Elias; Xavier, Ana Paula; Hirota, Vinicius Barroso; Côrrea, Sônia Cavalcanti; Caperuto, Érico Chagas

    2016-01-01

    This data paper contains data related to a reproducibility test for running pacing strategy in an intermittent running test until exhaustion. Ten participants underwent a crossover study (test and retest) with an intermittent running test. The test was composed of three-minute sets (at 1 km/h above Onset Blood Lactate Accumulation) until volitional exhaustion. To assess pace strategy change, in the first test participants chose the rest time interval (RTI) between sets (ranging from 30 to 60 s) and in the second test the maximum RTI values were either the RTI chosen in the first test (maximum RTI value), or less if desired. To verify the reproducibility of the test, rating perceived exertion (RPE), heart rate (HR) and blood plasma lactate concentration ([La]p) were collected at rest, immediately after each set and at the end of the tests. As results, RTI, RPE, HR, [La]p and time to exhaustion were not statistically different (p>0.05) between test and retest, as well as they demonstrated good intraclass correlation. PMID:27081672

  11. Towards reproducible MRM based biomarker discovery using dried blood spots.

    PubMed

    Ozcan, Sureyya; Cooper, Jason D; Lago, Santiago G; Kenny, Diarmuid; Rustogi, Nitin; Stocki, Pawel; Bahn, Sabine

    2017-03-27

    There is an increasing interest in the use of dried blood spot (DBS) sampling and multiple reaction monitoring in proteomics. Although several groups have explored the utility of DBS by focusing on protein detection, the reproducibility of the approach and whether it can be used for biomarker discovery in high throughput studies is yet to be determined. We assessed the reproducibility of multiplexed targeted protein measurements in DBS compared to serum. Eighty-two medium to high abundance proteins were monitored in a number of technical and biological replicates. Importantly, as part of the data analysis, several statistical quality control approaches were evaluated to detect inaccurate transitions. After implementing statistical quality control measures, the median CV on the original scale for all detected peptides in DBS was 13.2% and in Serum 8.8%. We also found a strong correlation (r = 0.72) between relative peptide abundance measured in DBS and serum. The combination of minimally invasive sample collection with a highly specific and sensitive mass spectrometry (MS) technique allows for targeted quantification of multiple proteins in a single MS run. This approach has the potential to fundamentally change clinical proteomics and personalized medicine by facilitating large-scale studies.

  12. A Telescope Inventor's Spyglass Possibly Reproduced in a Brueghel's Painting

    NASA Astrophysics Data System (ADS)

    Molaro, P.; Selvelli, P.

    2011-06-01

    Jan Brueghel the Elder depicted spyglasses belonging to the Archduke Albert VII of Habsburg in at least five paintings in the period between 1608 and 1625. Albert VII was fascinated by art and science and he obtained spyglasses directly from Lipperhey and Sacharias Janssen approximately at the time when the telescope was first shown at The Hague at the end of 1608. In the Extensive Landscape with View of the Castle of Mariemont, dated 1608-1612, the Archduke is looking at his Mariemont castle through an optical tube and this is the first time a spyglass was painted whatsoever. It is quite possible that the painting reproduces one of the first telescopes ever made. Two other Albert VII's telescopes are prominently reproduced in two Allegories of Sight painted a few years later (1617-1618). They are sophisticated instruments and their structure, in particular the shape of the eyepiece, suggests that they are composed by two convex lenses in a Keplerian optical configuration which became of common use only more than two decades later. If this is the case, these paintings are the first available record of a Keplerian telescope.

  13. Reproducibility of UAV-based photogrammetric surface models

    NASA Astrophysics Data System (ADS)

    Anders, Niels; Smith, Mike; Cammeraat, Erik; Keesstra, Saskia

    2016-04-01

    Soil erosion, rapid geomorphological change and vegetation degradation are major threats to the human and natural environment in many regions. Unmanned Aerial Vehicles (UAVs) and Structure-from-Motion (SfM) photogrammetry are invaluable tools for the collection of highly detailed aerial imagery and subsequent low cost production of 3D landscapes for an assessment of landscape change. Despite the widespread use of UAVs for image acquisition in monitoring applications, the reproducibility of UAV data products has not been explored in detail. This paper investigates this reproducibility by comparing the surface models and orthophotos derived from different UAV flights that vary in flight direction and altitude. The study area is located near Lorca, Murcia, SE Spain, which is a semi-arid medium-relief locale. The area is comprised of terraced agricultural fields that have been abandoned for about 40 years and have suffered subsequent damage through piping and gully erosion. In this work we focused upon variation in cell size, vertical and horizontal accuracy, and horizontal positioning of recognizable landscape features. The results suggest that flight altitude has a significant impact on reconstructed point density and related cell size, whilst flight direction affects the spatial distribution of vertical accuracy. The horizontal positioning of landscape features is relatively consistent between the different flights. We conclude that UAV data products are suitable for monitoring campaigns for land cover purposes or geomorphological mapping, but special care is required when used for monitoring changes in elevation.

  14. Towards reproducible MRM based biomarker discovery using dried blood spots

    PubMed Central

    Ozcan, Sureyya; Cooper, Jason D.; Lago, Santiago G.; Kenny, Diarmuid; Rustogi, Nitin; Stocki, Pawel; Bahn, Sabine

    2017-01-01

    There is an increasing interest in the use of dried blood spot (DBS) sampling and multiple reaction monitoring in proteomics. Although several groups have explored the utility of DBS by focusing on protein detection, the reproducibility of the approach and whether it can be used for biomarker discovery in high throughput studies is yet to be determined. We assessed the reproducibility of multiplexed targeted protein measurements in DBS compared to serum. Eighty-two medium to high abundance proteins were monitored in a number of technical and biological replicates. Importantly, as part of the data analysis, several statistical quality control approaches were evaluated to detect inaccurate transitions. After implementing statistical quality control measures, the median CV on the original scale for all detected peptides in DBS was 13.2% and in Serum 8.8%. We also found a strong correlation (r = 0.72) between relative peptide abundance measured in DBS and serum. The combination of minimally invasive sample collection with a highly specific and sensitive mass spectrometry (MS) technique allows for targeted quantification of multiple proteins in a single MS run. This approach has the potential to fundamentally change clinical proteomics and personalized medicine by facilitating large-scale studies. PMID:28345601

  15. Reproducible and inexpensive probe preparation for oligonucleotide arrays.

    PubMed

    Zhang, Y; Price, B D; Tetradis, S; Chakrabarti, S; Maulik, G; Makrigiorgos, G M

    2001-07-01

    We present a new protocol for the preparation of nucleic acids for microarray hybridization. DNA is fragmented quantitatively and reproducibly by using a hydroxyl radical-based reaction, which is initiated by hydrogen peroxide, iron(II)-EDTA and ascorbic acid. Following fragmentation, the nucleic acid fragments are densely biotinylated using a biotinylated psoralen analog plus UVA light and hybridized on microarrays. This non-enzymatic protocol circumvents several practical difficulties associated with DNA preparation for microarrays: the lack of reproducible fragmentation patterns associated with enzymatic methods; the large amount of labeled nucleic acids required by some array designs, which is often combined with a limited amount of starting material; and the high cost associated with currently used biotinylation methods. The method is applicable to any form of nucleic acid, but is particularly useful when applying double-stranded DNA on oligonucleotide arrays. Validation of this protocol is demonstrated by hybridizing PCR products with oligonucleotide-coated microspheres and PCR amplified cDNA with Affymetrix Cancer GeneChip microarrays.

  16. Culture and Achievement Motivation

    ERIC Educational Resources Information Center

    Maehr, Martin L.

    1974-01-01

    A framework is suggested for the cross-cultural study of motivation that stresses the importance of contextual conditions in eliciting achievement motivation and emphasizes cultural relativity in the definition of the concept. (EH)

  17. Achieving Salary Equity

    ERIC Educational Resources Information Center

    Nevill, Dorothy D.

    1975-01-01

    Three techniques are outlined for use by higher education institutions to achieve salary equity: salary prediction (using various statistical procedures), counterparting (comparing salaries of persons of similar rank), and grievance procedures. (JT)

  18. Vapor Pressure of Aqueous Solutions of Electrolytes Reproduced with Coarse-Grained Models without Electrostatics.

    PubMed

    Perez Sirkin, Yamila A; Factorovich, Matías H; Molinero, Valeria; Scherlis, Damian A

    2016-06-14

    The vapor pressure of water is a key property in a large class of applications from the design of membranes for fuel cells and separations to the prediction of the mixing state of atmospheric aerosols. Molecular simulations have been used to compute vapor pressures, and a few studies on liquid mixtures and solutions have been reported on the basis of the Gibbs Ensemble Monte Carlo method in combination with atomistic force fields. These simulations are costly, making them impractical for the prediction of the vapor pressure of complex materials. The goal of the present work is twofold: (1) to demonstrate the use of the grand canonical screening approach ( Factorovich , M. H. J. Chem. Phys. 2014 , 140 , 064111 ) to compute the vapor pressure of solutions and to extend the methodology for the treatment of systems without a liquid-vapor interface and (2) to investigate the ability of computationally efficient high-resolution coarse-grained models based on the mW monatomic water potential and ions described exclusively with short-range interactions to reproduce the relative vapor pressure of aqueous solutions. We find that coarse-grained models of LiCl and NaCl solutions faithfully reproduce the experimental relative pressures up to high salt concentrations, despite the inability of these models to predict cohesive energies of the solutions or the salts. A thermodynamic analysis reveals that the coarse-grained models achieve the experimental activity coefficients of water in solution through a compensation of severely underestimated hydration and vaporization free energies of the salts. Our results suggest that coarse-grained models developed to replicate the hydration structure and the effective ion-ion attraction in solution may lead to this compensation. Moreover, they suggest an avenue for the design of coarse-grained models that accurately reproduce the activity coefficients of solutions.

  19. Microstructure of Thin Films

    DTIC Science & Technology

    1990-02-07

    optical properties ." (Final text in preparation). John Lehan, "Microstructural analysis of thin films by Rutherford Backscattering...correlation of optical properties and micro- Ion assisted deposition (IAD) is known to produce structure of IAD thin films with ion beam parameters thin films ...1.5-eV interband absorption. P (eV) R (%) P (, -V) R %) Optical properties of metal thin films in the spectral 0 98.3 0 88.8 range of

  20. Reproducibility of an aerobic endurance test for nonexpert swimmers

    PubMed Central

    Veronese da Costa, Adalberto; Costa, Manoel da Cunha; Carlos, Daniel Medeiros; Guerra, Luis Marcos de Medeiros; Silva, Antônio José; Barbosa, Tiago Manoel Cabral dos Santos

    2012-01-01

    Background: This study aimed to verify the reproduction of an aerobic test to determine nonexpert swimmers’ resistance. Methods: The sample consisted of 24 male swimmers (age: 22.79 ± 3.90 years; weight: 74.72 ± 11.44 kg; height: 172.58 ± 4.99 cm; and fat percentage: 15.19% ± 3.21%), who swim for 1 hour three times a week. A new instrument was used in this study (a Progressive Swim Test): the swimmer wore an underwater MP3 player and increased their swimming speed on hearing a beep after every 25 meters. Each swimmer’s heart rate was recorded before the test (BHR) and again after the test (AHR). The rate of perceived exertion (RPE) and the number of laps performed (NLP) were also recorded. The sample size was estimated using G*Power software (v 3.0.10; Franz Faul, Kiel University, Kiel, Germany). The descriptive values were expressed as mean and standard deviation. After confirming the normality of the data using both the Shapiro–Wilk and Levene tests, a paired t-test was performed to compare the data. The Pearson’s linear correlation (r) and intraclass coefficient correlation (ICC) tests were used to determine relative reproducibility. The standard error of measurement (SEM) and the coefficient of variation (CV) were used to determine absolute reproducibility. The limits of agreement and the bias of the absolute and relative values between days were determined by Bland–Altman plots. All values had a significance level of P < 0.05. Results: There were significant differences in AHR (P = 0.03) and NLP (P = 0.01) between the 2 days of testing. The obtained values were r > 0.50 and ICC > 0.66. The SEM had a variation of ±2% and the CV was <10%. Most cases were within the upper and lower limits of Bland–Altman plots, suggesting correlation of the results. The applicability of NLP showed greater robustness (r and ICC > 0.90; SEM < 1%; CV < 3%), indicating that the other variables can be used to predict incremental changes in the physiological condition

  1. Building Consensus on Community Standards for Reproducible Science

    NASA Astrophysics Data System (ADS)

    Lehnert, K. A.; Nielsen, R. L.

    2015-12-01

    As geochemists, the traditional model by which standard methods for generating, presenting, and using data have been generated relied on input from the community, the results of seminal studies, a variety of authoritative bodies, and has required a great deal of time. The rate of technological and related policy change has accelerated to the point that this historical model does not satisfy the needs of the community, publishers, or funders. The development of a new mechanism for building consensus raises a number of questions: Which aspects of our data are the focus of reproducibility standards? Who sets the standards? How do we subdivide the development of the consensus? We propose an open, transparent, and inclusive approach to the development of data and reproducibility standards that is organized around specific sub-disciplines and driven by the community of practitioners in those sub-disciplines. It should involve editors, program managers, and representatives of domain data facilities as well as professional societies, but avoid any single group to be the final authority. A successful example of this model is the Editors Roundtable, a cross section of editors, funders, and data facility managers that discussed and agreed on leading practices for the reporting of geochemical data in publications, including accessibility and format of the data, data quality information, and metadata and identifiers for samples (Goldstein et al., 2014). We argue that development of data and reproducibility standards needs to heavily rely on representatives from the community of practitioners to set priorities and provide perspective. Groups of editors, practicing scientists, and other stakeholders would be assigned the task of reviewing existing practices and recommending changes as deemed necessary. They would weigh the costs and benefits of changing the standards for that community, propose appropriate tools to facilitate those changes, work through the professional societies

  2. A Highly Reproducible Bolus Immobilization Technique for the Treatment of Scalp Malignancies

    SciTech Connect

    Lin, Steven H.; Latronico, Diane; Teslow, Terrance; Bajaj, Gopal K.

    2008-04-01

    Radiation treatment of scalp malignancies can be a challenge due to the multiple curved surfaces to which homogenous dose must be delivered. The most readily available techniques utilize linear accelerator-based technique of opposed lateral electron field abutting opposed lateral photon field with central blocking. Bolus material is used to achieve adequate skin dose. Although plans to add bolus material often occur in the virtual setting during treatment planning, the practical aspects of reproducibly maintain the bolus material along curved surfaces during the day-to-day patient setup can be a challenge. We present a case of a patient with squamous cell carcinoma of the scalp with neck node involvement treated with surgery followed by adjuvant radiotherapy. We demonstrate a unique immobilization technique that maintains the bolus material on the aquaplast mesh adherent to the patient's scalp as well as the neck. TomoTherapy with daily megavoltage computed tomography (CT) scan was utilized to verify the daily bolus position. We were able to maintain a 95% reproducibility rate. This technique reliably maintains the bolus material on the desired locations with minimum adjustments and manipulation by the therapist and is a technique that can be universally adapatable for conventional radiotherapy or intensity modulated radiation therapy (IMRT) techniques.

  3. Exchange Energy Density Functionals that reproduce the Linear Response Function of the Free Electron Gas

    NASA Astrophysics Data System (ADS)

    García-Aldea, David; Alvarellos, J. E.

    2009-03-01

    We present several nonlocal exchange energy density functionals that reproduce the linear response function of the free electron gas. These nonlocal functionals are constructed following a similar procedure used previously for nonlocal kinetic energy density functionals by Chac'on-Alvarellos-Tarazona, Garc'ia-Gonz'alez et al., Wang-Govind-Carter and Garc'ia-Aldea-Alvarellos. The exchange response function is not known but we have used the approximate response function developed by Utsumi and Ichimaru, even we must remark that the same ansatz can be used to reproduce any other response function with the same scaling properties. We have developed two families of new nonlocal functionals: one is constructed with a mathematical structure based on the LDA approximation -- the Dirac functional for the exchange - and for the second one the structure of the second order gradient expansion approximation is took as a model. The functionals are constructed is such a way that they can be used in localized systems (using real space calculations) and in extended systems (using the momentum space, and achieving a quasilinear scaling with the system size if a constant reference electron density is defined).

  4. PH Tester Gauge Repeatability and Reproducibility Study for WO3 Nanostructure Hydrothermal Growth Process

    NASA Astrophysics Data System (ADS)

    Abd Rashid, Amirul; Hayati Saad, Nor; Bien Chia Sheng, Daniel; Yee, Lee Wai

    2014-06-01

    PH value is one of the important variables for tungsten trioxide (WO3) nanostructure hydrothermal synthesis process. The morphology of the synthesized nanostructure can be properly controlled by measuring and controlling the pH value of the solution used in this facile synthesis route. Therefore, it is very crucial to ensure the gauge used for pH measurement is reliable in order to achieve the expected result. In this study, gauge repeatability and reproducibility (GR&R) method was used to assess the repeatability and reproducibility of the pH tester. Based on ANOVA method, the design of experimental metrics as well as the result of the experiment was analyzed using Minitab software. It was found that the initial GR&R value for the tester was at 17.55 % which considered as acceptable. To further improve the GR&R level, a new pH measuring procedure was introduced. With the new procedure, the GR&R value was able to be reduced to 2.05%, which means the tester is statistically very ideal to measure the pH of the solution prepared for WO3 hydrothermal synthesis process.

  5. Consecutive Morphology Controlling Operations for Highly Reproducible Mesostructured Perovskite Solar Cells.

    PubMed

    Wu, Yongzhen; Chen, Wei; Yue, Youfeng; Liu, Jian; Bi, Enbing; Yang, Xudong; Islam, Ashraful; Han, Liyuan

    2015-09-23

    Perovskite solar cells have shown high photovoltaic performance but suffer from low reproducibility, which is mainly caused by low uniformity of the active perovskite layer in the devices. The nonuniform perovskites further limit the fabrication of large size solar cells. In this work, we control the morphology of CH3NH3PbI3 on a mesoporous TiO2 substrate by employing consecutive antisolvent dripping and solvent-vapor fumigation during spin coating of the precursor solution. The solvent-vapor treatment is found to enhance the perovskite pore filling and increase the uniformity of CH3NH3PbI3 in the porous scaffold layer but slightly decrease the uniformity of the perovskite capping layer. An additional antisolvent dripping is employed to recover the uniform perovskite capping layer. Such consecutive morphology controlling operations lead to highly uniform perovskite in both porous and capping layers. By using the optimized perovskite deposition procedure, the reproducibility of mesostructured solar cells was greatly improved such that a total of 40 devices showed an average efficiency of 15.3% with a very small standard deviation of 0.32. Moreover, a high efficiency of 14.9% was achieved on a large-size cell with a working area of 1.02 cm(2).

  6. SNaPP: Simplified Nanoproteomics Platform for Reproducible Global Proteomic Analysis of Nanogram Protein Quantities

    SciTech Connect

    Huang, Eric L.; Piehowski, Paul D.; Orton, Daniel J.; Moore, Ronald J.; Qian, Wei-Jun; Casey, Cameron P.; Sun, Xiaofei; Dey, Sudhansu K.; Burnum-Johnson, Kristin E.; Smith, Richard D.

    2016-03-01

    Global proteomic analyses are now widely applied across biological research to study changes in an organism(s) proteome correlated with a perturbation, phenotype and/or time series of interest.[1-3] Further, it has been broadly established that efficient and reproducible sample preparation workflows are crucial to successful quantitative proteome comparisons, especially when applying label free methods.[4-8] However, clinical samples are often severely limited in quantity and can preclude the application of more robust bulk sample processing workflows due to e.g. contamination, carry-over, or sample losses.[9] This has limited the effective application of global proteomics for many sample types of great interest, e.g. LCM dissected tissues, FACS sorted cells, circulating tumor cells (CTC), and early embryos. In a typical proteomics experiment, bulk homogenization is applied to generate sufficient protein for processing (> 10 µg protein), and can blend the proteomes of many different cell types and disparate tissue regions. The resulting “average” proteome, can effectively render unobservable proteome changes of interest, and preclude important applications. Global proteomic analyses of complex protein samples in nanogram quantities require a fastidious approach to achieve in-depth protein coverage and quantitative reproducibility.

  7. FAST TRACK COMMUNICATION: Reproducible room temperature giant magnetocaloric effect in Fe-Rh

    NASA Astrophysics Data System (ADS)

    Manekar, Meghmalhar; Roy, S. B.

    2008-10-01

    We present the results of magnetocaloric effect (MCE) studies in polycrystalline Fe-Rh alloy over a temperature range of 250-345 K across the first order antiferromagnetic to ferromagnetic transition. By measuring the MCE under various thermomagnetic histories, contrary to the long held belief, we show here explicitly that the giant MCE in Fe-Rh near room temperature does not vanish after the first field cycle. In spite of the fact that the virgin magnetization curve is lost after the first field cycle near room temperature, reproducibility in the MCE under multiple field cycles can be achieved by properly choosing a combination of isothermal and adiabatic field variation cycles in the field-temperature phase space. This reproducible MCE leads to a large effective refrigerant capacity of 324.42 J kg-1, which is larger than that of the well-known magnetocaloric material Gd5Si2Ge2. This information could be important as Fe-Rh has the advantage of having a working temperature of around 300 K, which can be used for room temperature magnetic refrigeration.

  8. Reproducible, rugged, and inexpensive photocathode x-ray diode

    SciTech Connect

    Idzorek, G. C.; Tierney, T. E.; Lockard, T. E.; Moy, K. J.; Keister, J. W.

    2008-10-15

    The photoemissive cathode type of x-ray diode (XRD) is popular for measuring time and spectrally resolved output of pulsed power experiments. Vitreous carbon XRDs currently used on the Sandia National Laboratories Z-machine were designed in the early 1980s and use materials and processes no longer available. Additionally cathodes used in the high x-ray flux and dirty vacuum environment of a machine such as Z suffer from response changes requiring recalibration. In searching for a suitable replacement cathode, we discovered very high purity vitreous-carbon planchets are commercially available for use as biological substrates in scanning electron microscope (SEM) work. After simplifying the photocathode mounting to use commercially available components, we constructed a set of 20 XRDs using SEM planchets that were then calibrated at the National Synchrotron Light Source at Brookhaven National Laboratory. We present comparisons of the reproducibility and absolute calibrations between the current vitreous-carbon XRDs and our new design.

  9. New model for datasets citation and extraction reproducibility in VAMDC

    NASA Astrophysics Data System (ADS)

    Zwölf, Carlo Maria; Moreau, Nicolas; Dubernet, Marie-Lise

    2016-09-01

    In this paper we present a new paradigm for the identification of datasets extracted from the Virtual Atomic and Molecular Data Centre (VAMDC) e-science infrastructure. Such identification includes information on the origin and version of the datasets, references associated to individual data in the datasets, as well as timestamps linked to the extraction procedure. This paradigm is described through the modifications of the language used to exchange data within the VAMDC and through the services that will implement those modifications. This new paradigm should enforce traceability of datasets, favor reproducibility of datasets extraction, and facilitate the systematic citation of the authors having originally measured and/or calculated the extracted atomic and molecular data.

  10. Reproducible surface-enhanced Raman spectroscopy of small molecular anions

    NASA Astrophysics Data System (ADS)

    Owens, F. J.

    2011-03-01

    A gold-coated silicon substrate having an array of pyramidal shaped holes is shown to provide a reproducible surface-enhanced Raman spectra (SERS) in a number of inorganic ions such as ? , ? , ? , and ? deposited on the substrate as 10-3 to10-4 molar aqueous solutions of their salts. Of particular interest is the observation of a SERS effect in ? , the anion of ammonium nitrate, a commonly used terrorist explosive, suggesting the potential for sensitive detection of this material. An unusual increase in the frequency of the ? bending mode frequency is observed in the SERS spectra of KNO2. Density Functional Theory calculations of the frequencies of the normal modes of vibration of ? bonded to gold predict an upward shift of the frequencies compared with the calculated results for a free ? , suggesting a possible explanation for the shifts.

  11. A reproducible method for determination of nitrocellulose in soil.

    PubMed

    Macmillan, Denise K; Majerus, Chelsea R; Laubscher, Randy D; Shannon, John P

    2008-01-15

    A reproducible analytical method for determination of nitrocellulose in soil is described. The new method provides the precision and accuracy needed for quantitation of nitrocellulose in soils to enable worker safety on contaminated sites. The method utilizes water and ethanol washes to remove co-contaminants, acetone extraction of nitrocellulose, and base hydrolysis of the extract to reduce nitrate groups. The hydrolysate is then neutralized and analyzed by ion chromatography for determination of free nitrate and nitrite. A variety of bases for hydrolysis and acids for neutralization were evaluated, with 5N sodium hydroxide and carbon dioxide giving the most complete hydrolysis and interference-free neutralization, respectively. The concentration of nitrocellulose in the soil is calculated from the concentrations of nitrate and nitrite and the weight percentage of nitrogen content in nitrocellulose. The laboratory detection limit for the analysis is 10mg/kg. The method acceptance range for recovery of nitrocellulose from control samples is 78-105%.

  12. GigaDB: promoting data dissemination and reproducibility

    PubMed Central

    Sneddon, Tam P.; Si Zhe, Xiao; Edmunds, Scott C.; Li, Peter; Goodman, Laurie; Hunter, Christopher I.

    2014-01-01

    Often papers are published where the underlying data supporting the research are not made available because of the limitations of making such large data sets publicly and permanently accessible. Even if the raw data are deposited in public archives, the essential analysis intermediaries, scripts or software are frequently not made available, meaning the science is not reproducible. The GigaScience journal is attempting to address this issue with the associated data storage and dissemination portal, the GigaScience database (GigaDB). Here we present the current version of GigaDB and reveal plans for the next generation of improvements. However, most importantly, we are soliciting responses from you, the users, to ensure that future developments are focused on the data storage and dissemination issues that still need resolving. Database URL: http://www.gigadb.org PMID:24622612

  13. geoknife: Reproducible web-processing of large gridded datasets

    USGS Publications Warehouse

    Read, Jordan S.; Walker, Jordan I.; Appling, Alison P.; Blodgett, David L.; Read, Emily K.; Winslow, Luke A.

    2016-01-01

    Geoprocessing of large gridded data according to overlap with irregular landscape features is common to many large-scale ecological analyses. The geoknife R package was created to facilitate reproducible analyses of gridded datasets found on the U.S. Geological Survey Geo Data Portal web application or elsewhere, using a web-enabled workflow that eliminates the need to download and store large datasets that are reliably hosted on the Internet. The package provides access to several data subset and summarization algorithms that are available on remote web processing servers. Outputs from geoknife include spatial and temporal data subsets, spatially-averaged time series values filtered by user-specified areas of interest, and categorical coverage fractions for various land-use types.

  14. Reproducibility in density functional theory calculations of solids.

    PubMed

    Lejaeghere, Kurt; Bihlmayer, Gustav; Björkman, Torbjörn; Blaha, Peter; Blügel, Stefan; Blum, Volker; Caliste, Damien; Castelli, Ivano E; Clark, Stewart J; Dal Corso, Andrea; de Gironcoli, Stefano; Deutsch, Thierry; Dewhurst, John Kay; Di Marco, Igor; Draxl, Claudia; Dułak, Marcin; Eriksson, Olle; Flores-Livas, José A; Garrity, Kevin F; Genovese, Luigi; Giannozzi, Paolo; Giantomassi, Matteo; Goedecker, Stefan; Gonze, Xavier; Grånäs, Oscar; Gross, E K U; Gulans, Andris; Gygi, François; Hamann, D R; Hasnip, Phil J; Holzwarth, N A W; Iuşan, Diana; Jochym, Dominik B; Jollet, François; Jones, Daniel; Kresse, Georg; Koepernik, Klaus; Küçükbenli, Emine; Kvashnin, Yaroslav O; Locht, Inka L M; Lubeck, Sven; Marsman, Martijn; Marzari, Nicola; Nitzsche, Ulrike; Nordström, Lars; Ozaki, Taisuke; Paulatto, Lorenzo; Pickard, Chris J; Poelmans, Ward; Probert, Matt I J; Refson, Keith; Richter, Manuel; Rignanese, Gian-Marco; Saha, Santanu; Scheffler, Matthias; Schlipf, Martin; Schwarz, Karlheinz; Sharma, Sangeeta; Tavazza, Francesca; Thunström, Patrik; Tkatchenko, Alexandre; Torrent, Marc; Vanderbilt, David; van Setten, Michiel J; Van Speybroeck, Veronique; Wills, John M; Yates, Jonathan R; Zhang, Guo-Xu; Cottenier, Stefaan

    2016-03-25

    The widespread popularity of density functional theory has given rise to an extensive range of dedicated codes for predicting molecular and crystalline properties. However, each code implements the formalism in a different way, raising questions about the reproducibility of such predictions. We report the results of a community-wide effort that compared 15 solid-state codes, using 40 different potentials or basis set types, to assess the quality of the Perdew-Burke-Ernzerhof equations of state for 71 elemental crystals. We conclude that predictions from recent codes and pseudopotentials agree very well, with pairwise differences that are comparable to those between different high-precision experiments. Older methods, however, have less precise agreement. Our benchmark provides a framework for users and developers to document the precision of new applications and methodological improvements.

  15. Chimie douce preparation of reproducible silver coatings for SERS applications

    NASA Astrophysics Data System (ADS)

    Sidorov, Alexander V.; Grigorieva, Anastasia V.; Goldt, Anastasia E.; Eremina, Olga E.; Veselova, Irina A.; Savilov, Sergey V.; Goodilin, Eugene A.

    2016-12-01

    A new soft chemistry preparation method of submicron — thick porous coatings of metallic silver is suggested for possible surface enhanced Raman spectroscopy (SERS) applications. The method is based on facile deposition of diamminesilver (I) aerosols forming instantly a nanostructured layer by fast decomposition and self-reduction of [Ag(NH3)2]+ aqueous solutions onto surfaces of inorganic substrates under mild conditions of 280-300∘C in air. A strong difference in overall microstructures and related SERS signals of model analytes is found for substrates with different deposition time and in comparison with a standard magnetron deposition technique. It is demonstrated that the suggested method is predominant for formation of robust SERS substrates with a stable and reproducible SERS enhancement.

  16. Elimination of phase singularity to achieve superresolution in lossy metamaterials.

    PubMed

    Lee, Kwangchil; Jung, Youngjean; Padilla, Willie J; Kim, Kyoungsik

    2010-06-07

    The presence of absorption losses softens the singular behavior of transmission resonances and leads to a good image in spite of limited effective spatial frequency range. Nonetheless, we found that the phase singularity does not disappear despite the considerably reduced retardation effects by softening the transmission resonances. Because the phase singularity severely deteriorates the ideal image reconstruction, broad transmission bandwidth in spatial frequency domain is not sufficient enough to achieve superresolution in TiO(2) thin film lens. The present work predicts successful elimination of the phase singularity and the achievement of approximately lambda /12.9 superresolution in TiO(2) thin film lens through the phase correction method.

  17. A workflow for reproducing mean benthic gas fluxes

    NASA Astrophysics Data System (ADS)

    Fulweiler, Robinson W.; Emery, Hollie E.; Maguire, Timothy J.

    2016-08-01

    Long-term data sets provide unique opportunities to examine temporal variability of key ecosystem processes. The need for such data sets is becoming increasingly important as we try to quantify the impact of human activities across various scales and in some cases, as we try to determine the success of management interventions. Unfortunately, long-term benthic flux data sets for coastal ecosystems are rare and curating them is a challenge. If we wish to make our data available to others now and into the future, however, then we need to provide mechanisms that allow others to understand our methods, access the data, reproduce the results, and see updates as they become available. Here we use techniques, learned through the EarthCube Ontosoft Geoscience Paper of the Future project, to develop best practices to allow us to share a long-term data set of directly measured net sediment N2 fluxes and sediment oxygen demand at two sites in Narragansett Bay, Rhode Island (USA). This technical report describes the process we used, the challenges we faced, and the steps we will take in the future to ensure transparency and reproducibility. By developing these data and software sharing tools we hope to help disseminate well-curated data with provenance as well as products from these data, so that the community can better assess how this temperate estuary has changed over time. We also hope to provide a data sharing model for others to follow so that long-term estuarine data are more easily shared and not lost over time.

  18. Technique for the efficient and reproducible fabrication of electromagnetic levitation coils

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Curreri, P. A.; Theiss, J.; Abbaschian, G. J.

    1984-01-01

    A technique has been developed for fabricating electromagnetic induction coils in a reproducible manner. The process utilizes a split mandrel that can be disassembled to remove the mandrel from the coil. The technique has increased coil production rates by a factor of 8 over the freehand winding method. The success rate for producing a functional levitation coil has been increased from 50 percent to 95 percent. The levitation coil designed during this work has successfully levitated and melted a variety of alloys including Cu, Ag, Ag-Ni, Cu-Fe, Fe-C, and Nb-Ge. W was also levitated but not melted at temperatures as high as 2700 C. The highest sample melt temperature achieved was 2400 C for the Nb-Ge samples.

  19. High speed and reproducible analysis of nitrosamines by capillary electrophoresis with a sulfonated capillary.

    PubMed

    Taga, Atsushi; Nishi, Tomoko; Honda, Yoshitaka; Sato, Atsushi; Terashima, Hiroyuki; Suzuki, Kentaro; Kodama, Shuji; Boki, Keito

    2007-01-01

    Recently environmental control is regarded as important for good human health conditions, and toxic substances, including carcinogens and endocrine disruptors should be eliminated from our living environment. Hence easy quantitative methods are expected for a high level of environmental control. Our previous paper describes an easy quantitative analysis of nitrosamines (NAs) by capillary electrophoresis with an untreated fused silica capillary installed in an ordinary apparatus. In this paper, utilizing a novel type capillary column having sulfonated inner wall was investigated for improvements of separation performance and reproducibility. A sulfonated capillary causes fast and stabile electroosmotic flow because its inner wall is strongly negative charged. On a performance comparison of a sulfonated capillary with an untreated fused silica, analysis time reduction of c.a. forty percent was achieved, and relative standard deviations of migration times and peak responses were less than one third. In addition sample concentrations giving detection and quantitation limits were also reduced to a half.

  20. Regional cerebral blood flow utilizing the gamma camera and xenon inhalation: reproducibility and clinical applications

    SciTech Connect

    Fox, R.A.; Knuckey, N.W.; Fleay, R.F.; Stokes, B.A.; Van der Schaaf, A.; Surveyor, I.

    1985-11-01

    A modified collimator and standard gamma camera have been used to measure regional cerebral blood flow following inhalation of radioactive xenon. The collimator and a simplified analysis technique enables excellent statistical accuracy to be achieved with acceptable precision in the measurement of grey matter blood flow. The validity of the analysis was supported by computer modelling and patient measurements. Sixty-one patients with subarachnoid hemorrhage, cerebrovascular disease or dementia were retested to determine the reproducibility of our method. The measured coefficient of variation was 6.5%. Of forty-six patients who had a proven subarachnoid hemorrhage, 15 subsequently developed cerebral ischaemia. These showed a CBF of 42 +/- 6 ml X minute-1 X 100 g brain-1 compared with 49 +/- 11 ml X minute-1 X 100 g brain-1 for the remainder. There is evidence that decreasing blood flow and low initial flow correlate with the subsequent onset of cerebral ischemia.

  1. Development of an air-knife system for highly reproducible fabrication of polydimethylsiloxane microstencils

    NASA Astrophysics Data System (ADS)

    Choi, Jin Ho; Kim, Gyu Man

    2015-08-01

    In this study, an air-knife system was developed for the automated fabrication of polymer microstencils with microscale perforated patterns. Blowing compressed N2 gas through the air knife provided a uniform laminar gas flow of high intensity suitable for perforating holes in the stencil. The polydimethylsiloxane (PDMS) stencil was replicated from a master mold prepared by photolithography. When the prepolymer of PDMS was spin-coated onto the master mold, a thin layer of the prepolymer remained on top of the master's structure and consequently prevented the formation of the perforated patterns. This residual layer was easily removed by the presented air knife. The air-knife system controlled the flow rate of N2 gas and the conveying speed of the master mold; therefore, the system possessed high reproducibility compared to manual gas blowing. Its use reduced the fabrication time for perforated biocompatible polymer microstencils, allowing for their mass production via an automated system. The validity of this suggested method was proven through experiments and was evaluated by application in various fields.

  2. Polycrystalline Thin-Film Photovoltaic Technologies: Progress and Technical Issues

    SciTech Connect

    Ullal, H. S.

    2004-08-01

    Polycrystalline thin-film materials based on copper indium diselenide (CuInSe2, CIS) and cadmium telluride (CdTe) are promising thin-film solar cells for various power and specialty applications. Impressive results have been obtained in the past few years for both thin-film copper indium gallium diselenide (CIGS) solar cells and thin-film CdTe solar cells. NCPV/NREL scientists have achieved world-record, total-area efficiencies of 19.3% for a thin-film CIGS solar cell and 16.5% for thin-film CdTe solar cell. A number of technical R&D issues related to CIS and CdTe have been identified. Thin-film power module efficiencies up to 13.4% has been achieved thus far. Tremendous progress has been made in the technology development for module fabrication, and multi-megawatt manufacturing facilities are coming on line with expansion plans in the next few years. Several 40-480 kW polycrystalline thin-film, grid-connected PV arrays have been deployed worldwide. Hot and humid testing is also under way to validate the long-term reliability of these emerging thin-film power products. The U.S. thin-film production (amorphous silicon[a-Si], CIS, CdTe) is expected to exceed 50 MW by the end of 2005.

  3. SALT and Spelling Achievement.

    ERIC Educational Resources Information Center

    Nelson, Joan

    A study investigated the effects of suggestopedic accelerative learning and teaching (SALT) on the spelling achievement, attitudes toward school, and memory skills of fourth-grade students. Subjects were 20 male and 28 female students from two self-contained classrooms at Kennedy Elementary School in Rexburg, Idaho. The control classroom and the…

  4. Iowa Women of Achievement.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

  5. Schools Achieving Gender Equity.

    ERIC Educational Resources Information Center

    Revis, Emma

    This guide is designed to assist teachers presenting the Schools Achieving Gender Equity (SAGE) curriculum for vocational education students, which was developed to align gender equity concepts with the Kentucky Education Reform Act (KERA). Included in the guide are lesson plans for classes on the following topics: legal issues of gender equity,…

  6. Achieving Peace through Education.

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

  7. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  8. Increasing Male Academic Achievement

    ERIC Educational Resources Information Center

    Jackson, Barbara Talbert

    2008-01-01

    The No Child Left Behind legislation has brought greater attention to the academic performance of American youth. Its emphasis on student achievement requires a closer analysis of assessment data by school districts. To address the findings, educators must seek strategies to remedy failing results. In a mid-Atlantic district of the Unites States,…

  9. Appraising Reading Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    To determine quality sequence in pupil progress, evaluation approaches need to be used which guide the teacher to assist learners to attain optimally. Teachers must use a variety of procedures to appraise student achievement in reading, because no one approach is adequate. Appraisal approaches might include: (1) observation and subsequent…

  10. Cognitive Processes and Achievement.

    ERIC Educational Resources Information Center

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  11. Graders' Mathematics Achievement

    ERIC Educational Resources Information Center

    Bond, John B.; Ellis, Arthur K.

    2013-01-01

    The purpose of this experimental study was to investigate the effects of metacognitive reflective assessment instruction on student achievement in mathematics. The study compared the performance of 141 students who practiced reflective assessment strategies with students who did not. A posttest-only control group design was employed, and results…

  12. Achieving All Our Ambitions

    ERIC Educational Resources Information Center

    Hartley, Tricia

    2009-01-01

    National learning and skills policy aims both to build economic prosperity and to achieve social justice. Participation in higher education (HE) has the potential to contribute substantially to both aims. That is why the Campaign for Learning has supported the ambition to increase the proportion of the working-age population with a Level 4…

  13. Improving Educational Achievement.

    ERIC Educational Resources Information Center

    New York University Education Quarterly, 1979

    1979-01-01

    This is a slightly abridged version of the report of the National Academy of Education panel, convened at the request of HEW Secretary Joseph Califano and Assistant Secretary for Education Mary F. Berry, to study recent declines in student achievement and methods of educational improvement. (SJL)

  14. The Achievement Club

    ERIC Educational Resources Information Center

    Rogers, Ibram

    2009-01-01

    When Gabrielle Carpenter became a guidance counselor in Northern Virginia nine years ago, she focused on the academic achievement gap and furiously tried to close it. At first, she was compelled by tremendous professional interest. However, after seeing her son lose his zeal for school, Carpenter joined forces with other parents to form an…

  15. Achievement in Problem Solving

    ERIC Educational Resources Information Center

    Friebele, David

    2010-01-01

    This Action Research Project is meant to investigate the effects of incorporating research-based instructional strategies into instruction and their subsequent effect on student achievement in the area of problem-solving. The two specific strategies utilized are the integration of manipulatives and increased social interaction on a regular basis.…

  16. Essays on Educational Achievement

    ERIC Educational Resources Information Center

    Ampaabeng, Samuel Kofi

    2013-01-01

    This dissertation examines the determinants of student outcomes--achievement, attainment, occupational choices and earnings--in three different contexts. The first two chapters focus on Ghana while the final chapter focuses on the US state of Massachusetts. In the first chapter, I exploit the incidence of famine and malnutrition that resulted to…

  17. Advancing Student Achievement

    ERIC Educational Resources Information Center

    Walberg, Herbert J.

    2010-01-01

    For the last half century, higher spending and many modern reforms have failed to raise the achievement of students in the United States to the levels of other economically advanced countries. A possible explanation, says Herbert Walberg, is that much current education theory is ill informed about scientific psychology, often drawing on fads and…

  18. NCLB: Achievement Robin Hood?

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  19. Thin EFG octagons

    NASA Astrophysics Data System (ADS)

    Kalejs, J. P.

    1994-01-01

    Mobil Solar Energy Corporation currently practices a unique crystal growth technology for producing crystalline silicon sheet, which is then cut with lasers into wafers. The wafers are processed into solar cells and incorporated into modules for photovoltaic applications. The silicon sheet is produced using a method known as Edge-defined Film-fed growth (EFG), in the form of hollow eight-sided polygons (octagons) with 10 cm faces. These are grown to lengths of 5 meters and thickness of 300 microns, with continuous melt replenishment, in compact furnaces designed to operate at a high sheet area production area of 135 sq cm/min. The present Photovoltaic Manufacturing Technology (PVMaT) three-year program seeks to advance the manufacturing line capabilities of the Mobil Solar crystal growth and cutting technologies. If successful, these advancements will provide significant reductions in already low silicon raw material usage, improve process productivity, laser cutting throughput and yield, and so lower both individual wafer cost and the cost of module production. This report summarizes the significant technical improvements in EFG technology achieved in Phase 1 of this program. Technical results are reported for each of the three main program areas: (1) thin octagon growth (crystal growth) -- to reduce the thickness of the octagon to an interim goal of 250 microns during Phase 1, with an ultimate goal of achieving 200 micron thicknesses; (2) laser cutting -- to improve the laser cutting process, so as to produce wafers with decreased laser cutting damage at increased wafer throughput rates; and (3) process control and product specification -- to implement advanced strategies in crystal growth process control and productivity designed to increase wafer yields.

  20. Magnetization reversal in ferromagnetic thin films induced by spin-orbit interaction with Slonczewski-like spin transfer torque

    SciTech Connect

    Li, Jia

    2014-10-07

    We theoretically investigate the dynamics of magnetization in ferromagnetic thin films induced by spin-orbit interaction with Slonczewski-like spin transfer torque. We reproduce the experimental results of perpendicular magnetic anisotropy films by micromagnetic simulation. Due to the spin-orbit interaction, the magnetization can be switched by changing the direction of the current with the assistant of magnetic field. By increasing the current amplitude, wider range of switching events can be achieved. Time evolution of magnetization has provided us a clear view of the process, and explained the role of minimum external field. Slonczewski-like spin transfer torque modifies the magnetization when current is present. The magnitude of the minimum external field is determined by the strength of the Slonczewski-like spin transfer torque. The investigations may provide potential applications in magnetic memories.

  1. Faculty achievement tracking tool.

    PubMed

    Pettus, Sarah; Reifschneider, Ellen; Burruss, Nancy

    2009-03-01

    Faculty development and scholarship is an expectation of nurse educators. Accrediting institutions, such as the Commission on Collegiate Nursing Education, the National League for Nursing Accrediting Commission, and the Higher Learning Commission, all have criteria regarding faculty achievement. A faculty achievement tracking tool (FATT) was developed to facilitate documentation of accreditation criteria attainment. Based on criteria from accrediting organizations, the roles that are addressed include scholarship, service, and practice. Definitions and benchmarks for the faculty as an aggregate are included. Undergoing reviews from different accrediting organizations, the FATT has been used once for accreditation of the undergraduate program and once for accreditation of the graduate program. The FATT is easy to use and has become an excellent adjunct for the preparation for accreditation reports. In addition, the FATT may be used for yearly evaluations, advancement, and merit.

  2. Project ACHIEVE final report

    SciTech Connect

    1997-06-13

    Project ACHIEVE was a math/science academic enhancement program aimed at first year high school Hispanic American students. Four high schools -- two in El Paso, Texas and two in Bakersfield, California -- participated in this Department of Energy-funded program during the spring and summer of 1996. Over 50 students, many of whom felt they were facing a nightmare future, were given the opportunity to work closely with personal computers and software, sophisticated calculators, and computer-based laboratories -- an experience which their regular academic curriculum did not provide. Math and science projects, exercises, and experiments were completed that emphasized independent and creative applications of scientific and mathematical theories to real world problems. The most important outcome was the exposure Project ACHIEVE provided to students concerning the college and technical-field career possibilities available to them.

  3. Diet rapidly and reproducibly alters the human gut microbiome

    PubMed Central

    David, Lawrence A.; Maurice, Corinne F.; Carmody, Rachel N.; Gootenberg, David B.; Button, Julie E.; Wolfe, Benjamin E.; Ling, Alisha V.; Devlin, A. Sloan; Varma, Yug; Fischbach, Michael A.; Biddinger, Sudha B.; Dutton, Rachel J.; Turnbaugh, Peter J.

    2013-01-01

    Long-term diet influences the structure and activity of the trillions of microorganisms residing in the human gut1–5, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here, we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila, and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale, and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals2, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi, and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids, and the outgrowth of microorganisms capable of triggering inflammatory bowel disease6. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. PMID:24336217

  4. Resting Functional Connectivity of Language Networks: Characterization and Reproducibility

    PubMed Central

    Tomasi, Dardo; Volkow, Nora D.

    2011-01-01

    The neural basis of language comprehension and production has been associated with superior temporal (Wernicke’s) and inferior frontal (Broca’s) cortical areas respectively. However, recent resting state functional connectivity (RSFC) and lesion studies implicate a more extended network in language processing. Using a large RSFC dataset from 970 healthy subjects and seed regions in Broca’s and Wernicke’s we recapitulate this extended network that includes adjoining prefrontal, temporal and parietal regions but also bilateral caudate and left putamen/globus pallidus and subthalamic nucleus. We also show that the language network has predominance of short-range functional connectivity (except posterior Wernicke’s area that exhibited predominant long-range connectivity), which is consistent with reliance on local processing. Predominantly, the long-range connectivity was left lateralized (except anterior Wernicke’s area that exhibited rightward lateralization). The language network also exhibited anticorrelated activity with auditory (only for Wernickes’s area) and visual cortices that suggests integrated sequential activity with regions involved with listening or reading words. Assessment of the intra subject’s reproducibility of this network and its characterization in individuals with language dysfunction is needed to determine its potential as a biomarker for language disorders. PMID:22212597

  5. Virtual Raters for Reproducible and Objective Assessments in Radiology

    NASA Astrophysics Data System (ADS)

    Kleesiek, Jens; Petersen, Jens; Döring, Markus; Maier-Hein, Klaus; Köthe, Ullrich; Wick, Wolfgang; Hamprecht, Fred A.; Bendszus, Martin; Biller, Armin

    2016-04-01

    Volumetric measurements in radiologic images are important for monitoring tumor growth and treatment response. To make these more reproducible and objective we introduce the concept of virtual raters (VRs). A virtual rater is obtained by combining knowledge of machine-learning algorithms trained with past annotations of multiple human raters with the instantaneous rating of one human expert. Thus, he is virtually guided by several experts. To evaluate the approach we perform experiments with multi-channel magnetic resonance imaging (MRI) data sets. Next to gross tumor volume (GTV) we also investigate subcategories like edema, contrast-enhancing and non-enhancing tumor. The first data set consists of N = 71 longitudinal follow-up scans of 15 patients suffering from glioblastoma (GB). The second data set comprises N = 30 scans of low- and high-grade gliomas. For comparison we computed Pearson Correlation, Intra-class Correlation Coefficient (ICC) and Dice score. Virtual raters always lead to an improvement w.r.t. inter- and intra-rater agreement. Comparing the 2D Response Assessment in Neuro-Oncology (RANO) measurements to the volumetric measurements of the virtual raters results in one-third of the cases in a deviating rating. Hence, we believe that our approach will have an impact on the evaluation of clinical studies as well as on routine imaging diagnostics.

  6. Reproducing Natural Spider Silks' Copolymer Behavior in Synthetic Silk Mimics

    SciTech Connect

    An, Bo; Jenkins, Janelle E; Sampath, Sujatha; Holland, Gregory P; Hinman, Mike; Yarger, Jeffery L; Lewis, Randolph

    2012-10-30

    Dragline silk from orb-weaving spiders is a copolymer of two large proteins, major ampullate spidroin 1 (MaSp1) and 2 (MaSp2). The ratio of these proteins is known to have a large variation across different species of orb-weaving spiders. NMR results from gland material of two different species of spiders, N. clavipes and A. aurantia, indicates that MaSp1 proteins are more easily formed into β-sheet nanostructures, while MaSp2 proteins form random coil and helical structures. To test if this behavior of natural silk proteins could be reproduced by recombinantly produced spider silk mimic protein, recombinant MaSp1/MaSp2 mixed fibers as well as chimeric silk fibers from MaSp1 and MaSp2 sequences in a single protein were produced based on the variable ratio and conserved motifs of MaSp1 and MaSp2 in native silk fiber. Mechanical properties, solid-state NMR, and XRD results of tested synthetic fibers indicate the differing roles of MaSp1 and MaSp2 in the fiber and verify the importance of postspin stretching treatment in helping the fiber to form the proper spatial structure.

  7. Reproducibility of Differential Proteomic Technologies in CPTAC Fractionated Xenografts

    PubMed Central

    2015-01-01

    The NCI Clinical Proteomic Tumor Analysis Consortium (CPTAC) employed a pair of reference xenograft proteomes for initial platform validation and ongoing quality control of its data collection for The Cancer Genome Atlas (TCGA) tumors. These two xenografts, representing basal and luminal-B human breast cancer, were fractionated and analyzed on six mass spectrometers in a total of 46 replicates divided between iTRAQ and label-free technologies, spanning a total of 1095 LC–MS/MS experiments. These data represent a unique opportunity to evaluate the stability of proteomic differentiation by mass spectrometry over many months of time for individual instruments or across instruments running dissimilar workflows. We evaluated iTRAQ reporter ions, label-free spectral counts, and label-free extracted ion chromatograms as strategies for data interpretation (source code is available from http://homepages.uc.edu/~wang2x7/Research.htm). From these assessments, we found that differential genes from a single replicate were confirmed by other replicates on the same instrument from 61 to 93% of the time. When comparing across different instruments and quantitative technologies, using multiple replicates, differential genes were reproduced by other data sets from 67 to 99% of the time. Projecting gene differences to biological pathways and networks increased the degree of similarity. These overlaps send an encouraging message about the maturity of technologies for proteomic differentiation. PMID:26653538

  8. Reproducibility and reliability of fetal cardiac time intervals using magnetocardiography.

    PubMed

    van Leeuwen, P; Lange, S; Klein, A; Geue, D; Zhang, Y; Krause, H J; Grönemeyer, D

    2004-04-01

    We investigated several factors which may affect the accuracy of fetal cardiac time intervals (CTI) determined in magnetocardiographic (MCG) recordings: observer differences, the number of available recording sites and the type of sensor used in acquisition. In 253 fetal MCG recordings, acquired using different biomagnetometer devices between the 15th and 42nd weeks of gestation, P-wave, QRS complex and T-wave onsets and ends were identified in signal averaged data sets independently by different observers. Using a defined procedure for setting signal events, interobserver reliability was high. Increasing the number of registration sites led to more accurate identification of the events. The differences in wave morphology between magnetometer and gradiometer configurations led to deviations in timing whereas the differences between low and high temperature devices seemed to be primarily due to noise. Signal-to-noise ratio played an important overall role in the accurate determination of CTI and changes in signal amplitude associated with fetal maturation may largely explain the effects of gestational age on reproducibility. As fetal CTI may be of value in the identification of pathologies such as intrauterine growth retardation or fetal cardiac hypertrophy, their reliable estimation will be enhanced by strategies which take these factors into account.

  9. Direct, quantitative clinical assessment of hand function: usefulness and reproducibility.

    PubMed

    Goodson, Alexander; McGregor, Alison H; Douglas, Jane; Taylor, Peter

    2007-05-01

    Methods of assessing functional impairment in arthritic hands include pain assessments and disability scoring scales which are subjective, variable over time and fail to take account of the patients' need to adapt to deformities. The aim of this study was to evaluate measures of functional strength and joint motion in the assessment of the rheumatoid (RA) and osteoarthritic (OA) hand. Ten control subjects, ten RA and ten OA patients were recruited for the study. All underwent pain and disability scoring and functional assessment of the hand using measures of pinch/grip strength and range of joint motion (ROM). Functional assessments including ROM analyses at interphalangeal (IP), metacarpophalangeal (MCP) and wrist joints along with pinch/grip strength clearly discriminated between patient groups (RA vs. OA MCP ROM P<0.0001), pain and disability scales were unable to. In the RA there were demonstrable relationships between ROM measurements and disability (R2=0.31) as well as disease duration (R2=0.37). Intra-patient measures of strength were robust whereas inter-patient comparisons showed variability. In conclusion, pinch/grip strength and ROM are clinically reproducible assessments that may more accurately reflect functional impairment associated with arthritis.

  10. Numerically reproduced internal wave spectra in the deep ocean

    NASA Astrophysics Data System (ADS)

    Sugiyama, Yoshifumi; Niwa, Yoshihiro; Hibiya, Toshiyuki

    2009-04-01

    A vertically two-dimensional internal wave field is forced equally at the near-inertial frequency and the semidiurnal tidal frequency both at the lowest vertical wavenumber. These correspond to wind forcing and internal tide forcing, the main energy sources for the internal wave field. After 5 years of spin-up, a quasi-stationary internal wave field with characteristics of the Garrett-Munk-like spectrum is successfully reproduced. Furthermore, we carry out additional experiments by changing the strength of the semidiurnal tidal forcing relative to the near-inertial forcing. It is demonstrated that the Garrett-Munk-like spectrum is created and maintained only when energy is supplied both from the near-inertial forcing and the semidiurnal tidal forcing. So long as both energy sources are available, nonlinear interactions among internal waves occur such that the resulting internal wave spectrum becomes close to the Garrett-Munk-like spectrum irrespective of the ratio of the near-inertial forcing to the semidiurnal tidal forcing.

  11. Reproducing Natural Spider Silks’ Copolymer Behavior in Synthetic Silk Mimics

    PubMed Central

    An, Bo; Jenkins, Janelle E.; Sampath, Sujatha; Holland, Gregory P.; Hinman, Mike; Yarger, Jeffery L.; Lewis, Randolph

    2012-01-01

    Dragline silk from orb-weaving spiders is a copolymer of two large proteins, major ampullate spidroin 1 (MaSp1) and 2 (MaSp2). The ratio of these proteins is known to have a large variation across different species of orb-weaving spiders. NMR results from gland material of two different species of spiders, N. clavipes and A. aurantia, indicates that MaSp1 proteins are more easily formed into β-sheet nanostructures, while MaSp2 proteins form random coil and helical structures. To test if this behavior of natural silk proteins could be reproduced by recombinantly produced spider silk mimic protein, recombinant MaSp1/MaSp2 mixed fibers as well as chimeric silk fibers from MaSp1 and MaSp2 sequences in a single protein were produced based on the variable ratio and conserved motifs of MaSp1 and MaSp2 in native silk fiber. Mechanical properties, solid-state NMR, and XRD results of tested synthetic fibers indicate the differing roles of MaSp1 and MaSp2 in the fiber and verify the importance of postspin stretching treatment in helping the fiber to form the proper spatial structure. PMID:23110450

  12. Repeatability and reproducibility of aquatic testing with zinc dithiophosphate

    SciTech Connect

    Hooter, D.L.; Hoke, D.I.; Kraska, R.C.; Wojewodka, R.A.

    1994-12-31

    This testing program was designed to characterize the repeatability and reproducibility of aquatic screening studies with a water insoluble chemical substance. Zinc dithiophosphate was selected for its limited water solubility and moderate aquatic toxicity. Acute tests were conducted using fathead minnows and Daphnia magna, according to guidelines developed to minimize random sources of non-repeatability. Zinc dithiosphosphate was exposed to the organisms in static tests using an oil-water dispersion method for the fathead minnows, and a water-accommodated-fraction method for the Daphnia magna. Testing was conducted in moderately hard water with pre-determined nominal concentrations of 0. 1, 1.0, 10.0, 100.00, and 1000.0 ppm or ppm WAF. 24 studies were contracted among 3 separate commercial contract laboratories. The program results demonstrate the diverse range of intralaboratory and interlaboratory variability based on the organism type, and emphasize the need for further study and caution in the design, and implementation of aquatic testing for insoluble materials.

  13. Can a coupled meteorology–chemistry model reproduce the ...

    EPA Pesticide Factsheets

    The ability of a coupled meteorology–chemistry model, i.e., Weather Research and Forecast and Community Multiscale Air Quality (WRF-CMAQ), to reproduce the historical trend in aerosol optical depth (AOD) and clear-sky shortwave radiation (SWR) over the Northern Hemisphere has been evaluated through a comparison of 21-year simulated results with observation-derived records from 1990 to 2010. Six satellite-retrieved AOD products including AVHRR, TOMS, SeaWiFS, MISR, MODIS-Terra and MODIS-Aqua as well as long-term historical records from 11 AERONET sites were used for the comparison of AOD trends. Clear-sky SWR products derived by CERES at both the top of atmosphere (TOA) and surface as well as surface SWR data derived from seven SURFRAD sites were used for the comparison of trends in SWR. The model successfully captured increasing AOD trends along with the corresponding increased TOA SWR (upwelling) and decreased surface SWR (downwelling) in both eastern China and the northern Pacific. The model also captured declining AOD trends along with the corresponding decreased TOA SWR (upwelling) and increased surface SWR (downwelling) in the eastern US, Europe and the northern Atlantic for the period of 2000–2010. However, the model underestimated the AOD over regions with substantial natural dust aerosol contributions, such as the Sahara Desert, Arabian Desert, central Atlantic and northern Indian Ocean. Estimates of the aerosol direct radiative effect (DRE) at TOA a

  14. Highly reproducible thermocontrolled electrospun fiber based organic photovoltaic devices.

    PubMed

    Kim, Taehoon; Yang, Seung Jae; Sung, Sae Jin; Kim, Yern Seung; Chang, Mi Se; Jung, Haesol; Park, Chong Rae

    2015-03-04

    In this work, we examined the reasons underlying the humidity-induced morphological changes of electrospun fibers and suggest a method of controlling the electrospun fiber morphology under high humidity conditions. We fabricated OPV devices composed of electrospun fibers, and the performance of the OPV devices depends significantly on the fiber morphology. The evaporation rate of a solvent at various relative humidity was measured to investigate the effects of the relative humidity during electrospinning process. The beaded nanofiber morphology of electrospun fibers was originated due to slow solvent evaporation rate under high humidity conditions. To increase the evaporation rate under high humidity conditions, warm air was applied to the electrospinning system. The beads that would have formed on the electrospun fibers were completely avoided, and the power conversion efficiencies of OPV devices fabricated under high humidity conditions could be restored. These results highlight the simplicity and effectiveness of the proposed method for improving the reproducibility of electrospun nanofibers and performances of devices consisting of the electrospun nanofibers, regardless of the relative humidity.

  15. Virtual Raters for Reproducible and Objective Assessments in Radiology

    PubMed Central

    Kleesiek, Jens; Petersen, Jens; Döring, Markus; Maier-Hein, Klaus; Köthe, Ullrich; Wick, Wolfgang; Hamprecht, Fred A.; Bendszus, Martin; Biller, Armin

    2016-01-01

    Volumetric measurements in radiologic images are important for monitoring tumor growth and treatment response. To make these more reproducible and objective we introduce the concept of virtual raters (VRs). A virtual rater is obtained by combining knowledge of machine-learning algorithms trained with past annotations of multiple human raters with the instantaneous rating of one human expert. Thus, he is virtually guided by several experts. To evaluate the approach we perform experiments with multi-channel magnetic resonance imaging (MRI) data sets. Next to gross tumor volume (GTV) we also investigate subcategories like edema, contrast-enhancing and non-enhancing tumor. The first data set consists of N = 71 longitudinal follow-up scans of 15 patients suffering from glioblastoma (GB). The second data set comprises N = 30 scans of low- and high-grade gliomas. For comparison we computed Pearson Correlation, Intra-class Correlation Coefficient (ICC) and Dice score. Virtual raters always lead to an improvement w.r.t. inter- and intra-rater agreement. Comparing the 2D Response Assessment in Neuro-Oncology (RANO) measurements to the volumetric measurements of the virtual raters results in one-third of the cases in a deviating rating. Hence, we believe that our approach will have an impact on the evaluation of clinical studies as well as on routine imaging diagnostics. PMID:27118379

  16. The inter-observer reproducibility of Shafer's sign.

    PubMed

    Qureshi, F; Goble, R

    2009-03-01

    Pigment cells in the anterior vitreous (Shafer's sign) are known to be associated with retinal breaks. We sought to identify the reproducibility of Shafer's sign between different grades of ophthalmic staff. In all 47 patients were examined by a consultant vitreo-retinal surgeon, a senior house officer (SHO) and optician for Shafer's sign. Cohen's kappa for consultant vs SHO assessment of Shafer's sign was 0.55 while for consultant vs optician assessment, kappa was 0.28. Retinal tears were present in 63.8% of our series. Consultant assessment of Shafer's sign with fundoscopy findings, we found specificity to be 93.5% while sensitivity was 93.8%. Kappa for consultant assessment of Shafer's sign vs break presence was 0.86.Consultant and SHO assessment of Shafer's sign is of moderate agreement while optician assessment is fair. These results suggest a relationship between training and the assessment of Shafer's sign. We feel this study suggests caution in undue reliance on Shafer's sign particularly for inexperienced members of staff.

  17. A silicon retina that reproduces signals in the optic nerve

    NASA Astrophysics Data System (ADS)

    Zaghloul, Kareem A.; Boahen, Kwabena

    2006-12-01

    Prosthetic devices may someday be used to treat lesions of the central nervous system. Similar to neural circuits, these prosthetic devices should adapt their properties over time, independent of external control. Here we describe an artificial retina, constructed in silicon using single-transistor synaptic primitives, with two forms of locally controlled adaptation: luminance adaptation and contrast gain control. Both forms of adaptation rely on local modulation of synaptic strength, thus meeting the criteria of internal control. Our device is the first to reproduce the responses of the four major ganglion cell types that drive visual cortex, producing 3600 spiking outputs in total. We demonstrate how the responses of our device's ganglion cells compare to those measured from the mammalian retina. Replicating the retina's synaptic organization in our chip made it possible to perform these computations using a hundred times less energy than a microprocessor—and to match the mammalian retina in size and weight. With this level of efficiency and autonomy, it is now possible to develop fully implantable intraocular prostheses.

  18. Reproducibility of measurements of trace gas concentrations in expired air.

    PubMed

    Strocchi, A; Ellis, C; Levitt, M D

    1991-07-01

    Measurement of the pulmonary excretion of trace gases has been used as a simple means of assessing metabolic reactions. End alveolar trace gas concentration, rather than excretory rate, is usually measured. However, the reproducibility of this measurement has received little attention. In 17 healthy subjects, duplicate collections of alveolar air were obtained within 1 minute of each other using a commercially available alveolar air sampler. The concentrations of hydrogen, methane, carbon monoxide, and carbon dioxide were measured. When the subject received no instruction on how to expire into the device, a difference of 28% +/- 19% (1SD) was found between duplicate determinations of hydrogen. Instructing the subjects to avoid hyperventilation or to inspire maximally and exhale immediately resulted in only minor reduction in variability. However, a maximal inspiration held for 15 seconds before exhalation reduced the difference to a mean of 9.6% +/- 8.0%, less than half that observed with the other expiratory techniques. Percentage difference of methane measurements with the four different expiratory techniques yielded results comparable to those obtained for hydrogen. In contrast, percentage differences for carbon monoxide measurements were similar for all expiratory techniques. When normalized to a PCO2 of 5%, the variability of hydrogen measurements with the breath-holding technique was reduced to 6.8% +/- 4.7%, a value significantly lower than that obtained with the other expiratory methods. This study suggests that attention to the expiratory technique could improve the accuracy of tests using breath hydrogen measurements.

  19. Reproducibility of Differential Proteomic Technologies in CPTAC Fractionated Xenografts

    SciTech Connect

    Tabb, David L.; Wang, Xia; Carr, Steven A.; Clauser, Karl R.; Mertins, Philipp; Chambers, Matthew C.; Holman, Jerry D.; Wang, Jing; Zhang, Bing; Zimmerman, Lisa J.; Chen, Xian; Gunawardena, Harsha P.; Davies, Sherri R.; Ellis, Matthew J. C.; Li, Shunqiang; Townsend, R. Reid; Boja, Emily S.; Ketchum, Karen A.; Kinsinger, Christopher R.; Mesri, Mehdi; Rodriguez, Henry; Liu, Tao; Kim, Sangtae; McDermott, Jason E.; Payne, Samuel H.; Petyuk, Vladislav A.; Rodland, Karin D.; Smith, Richard D.; Yang, Feng; Chan, Daniel W.; Zhang, Bai; Zhang, Hui; Zhang, Zhen; Zhou, Jian-Ying; Liebler, Daniel C.

    2016-03-04

    The NCI Clinical Proteomic Tumor Analysis Consortium (CPTAC) employed a pair of reference xenograft proteomes for initial platform validation and ongoing quality control of its data collection for The Cancer Genome Atlas (TCGA) tumors. These two xenografts, representing basal and luminal-B human breast cancer, were fractionated and analyzed on six mass spectrometers in a total of 46 replicates divided between iTRAQ and label-free technologies, spanning a total of 1095 LC-MS/MS experiments. These data represent a unique opportunity to evaluate the stability of proteomic differentiation by mass spectrometry over many months of time for individual instruments or across instruments running dissimilar workflows. We evaluated iTRAQ reporter ions, label-free spectral counts, and label-free extracted ion chromatograms as strategies for data interpretation. From these assessments we found that differential genes from a single replicate were confirmed by other replicates on the same instrument from 61-93% of the time. When comparing across different instruments and quantitative technologies, differential genes were reproduced by other data sets from 67-99% of the time. Projecting gene differences to biological pathways and networks increased the similarities. These overlaps send an encouraging message about the maturity of technologies for proteomic differentiation.

  20. Histopathologic reproducibility of thyroid disease in an epidemiologic study

    SciTech Connect

    Ron, E.; Griffel, B.; Liban, E.; Modan, B.

    1986-03-01

    An investigation of the long-term effects of childhood scalp irradiation demonstrated a significantly increased risk of thyroid tumors in the irradiated population. Because of the complexity of thyroid cancer diagnosis, a histopathologic slide review of 59 of the 68 patients (irradiated and nonirradiated) with thyroid disease was undertaken. The review revealed 90% agreement (kappa = +0.85, P less than 0.01) between the original and review diagnosis. Four of 27 cases previously diagnosed as malignant were reclassified as benign, yielding a cancer misdiagnosis rate of 14.8%. All four of the misdiagnosed cancers were of follicular or mixed papillary-follicular type. As a result of the histologic review, the ratio of malignant to benign tumors decreased from 2.55 to 1.75. Since disagreement in diagnosis was similar in the irradiated and nonirradiated groups, the relative risk of radiation-associated neoplasms did not change substantially. The histopathologic review shows that although there were some problems in diagnostic reproducibility, they were not statistically significant and did not alter our previous conclusions regarding radiation exposure. However, a 15% reduction in the number of malignancies might affect epidemiologic studies with an external comparison as well as geographic or temporal comparisons.

  1. Developmental pesticide exposure reproduces features of attention deficit hyperactivity disorder

    PubMed Central

    Richardson, Jason R.; Taylor, Michele M.; Shalat, Stuart L.; Guillot, Thomas S.; Caudle, W. Michael; Hossain, Muhammad M.; Mathews, Tiffany A.; Jones, Sara R.; Cory-Slechta, Deborah A.; Miller, Gary W.

    2015-01-01

    Attention-deficit hyperactivity disorder (ADHD) is estimated to affect 8–12% of school-age children worldwide. ADHD is a complex disorder with significant genetic contributions. However, no single gene has been linked to a significant percentage of cases, suggesting that environmental factors may contribute to ADHD. Here, we used behavioral, molecular, and neurochemical techniques to characterize the effects of developmental exposure to the pyrethroid pesticide deltamethrin. We also used epidemiologic methods to determine whether there is an association between pyrethroid exposure and diagnosis of ADHD. Mice exposed to the pyrethroid pesticide deltamethrin during development exhibit several features reminiscent of ADHD, including elevated dopamine transporter (DAT) levels, hyperactivity, working memory and attention deficits, and impulsive-like behavior. Increased DAT and D1 dopamine receptor levels appear to be responsible for the behavioral deficits. Epidemiologic data reveal that children aged 6–15 with detectable levels of pyrethroid metabolites in their urine were more than twice as likely to be diagnosed with ADHD. Our epidemiologic finding, combined with the recapitulation of ADHD behavior in pesticide-treated mice, provides a mechanistic basis to suggest that developmental pyrethroid exposure is a risk factor for ADHD.—Richardson, J. R., Taylor, M. M., Shalat, S. L., Guillot III, T. S., Caudle, W. M., Hossain, M. M., Mathews, T. A., Jones, S. R., Cory-Slechta, D. A., Miller, G. W. Developmental pesticide exposure reproduces features of attention deficit hyperactivity disorder. PMID:25630971

  2. Structural characterization of impurified zinc oxide thin films

    SciTech Connect

    Trinca, L. M.; Galca, A. C. Stancu, V. Chirila, C. Pintilie, L.

    2014-11-05

    Europium doped zinc oxide (Eu:ZnO) thin films have been obtained by pulsed laser deposition (PLD). 002 textured thin films were achieved on glass and silicon substrates, while hetero-epilayers and homo-epilayers have been attained on single crystal SrTiO{sub 3} and ZnO, respectively. X-ray Diffraction (XRD) was employed to characterize the Eu:ZnO thin films. Extended XRD studies confirmed the different thin film structural properties as function of chosen substrates.

  3. A highly reproducible quantitative viral outgrowth assay for the measurement of the replication-competent latent HIV-1 reservoir.

    PubMed

    Fun, Axel; Mok, Hoi Ping; Wills, Mark R; Lever, Andrew M

    2017-02-24

    Cure of Human Immunodeficiency Virus (HIV) infection remains elusive due to the persistence of HIV in a latent reservoir. Strategies to eradicate latent infection can only be evaluated with robust, sensitive and specific assays to quantitate reactivatable latent virus. We have taken the standard peripheral blood mononuclear cell (PBMC) based viral outgrowth methodology and from it created a logistically simpler and more highly reproducible assay to quantify replication-competent latent HIV in resting CD4(+) T cells, both increasing accuracy and decreasing cost and labour. Purification of resting CD4(+) T cells from whole PBMC is expedited and achieved in 3 hours, less than half the time of conventional protocols. Our indicator cell line, SupT1-CCR5 cells (a clonal cell line expressing CD4, CXCR4 and CCR5) provides a readily available standardised readout. Reproducibility compares favourably to other published assays but with reduced cost, labour and assay heterogeneity without compromising sensitivity.

  4. Reproducible preparation of nanospray tips for capillary electrophoresis coupled to mass spectrometry using 3D printed grinding device.

    PubMed

    Tycova, Anna; Prikryl, Jan; Foret, Frantisek

    2016-04-01

    The use of high quality fused silica capillary nanospray tips is critical for obtaining reliable and reproducible electrospray/MS data; however, reproducible laboratory preparation of such tips is a challenging task. In this work, we report on the design and construction of low-cost grinding device assembled from 3D printed and commercially easily available components. Detailed description and characterization of the grinding device is complemented by freely accessible files in stl and skp format allowing easy laboratory replication of the device. The process of sharpening is aimed at achieving maximal symmetricity, surface smoothness and repeatability of the conus shape. Moreover, the presented grinding device brings possibility to fabricate the nanospray tips of desired dimensions regardless of the commercial availability. On several samples of biological nature (reserpine, rabbit plasma, and the mixture of three aminoacids), performance of fabricated tips is shown on CE coupled to MS analysis. The special interest is paid to the effect of tip sharpness.

  5. A highly reproducible quantitative viral outgrowth assay for the measurement of the replication-competent latent HIV-1 reservoir

    PubMed Central

    Fun, Axel; Mok, Hoi Ping; Wills, Mark R.; Lever, Andrew M.

    2017-01-01

    Cure of Human Immunodeficiency Virus (HIV) infection remains elusive due to the persistence of HIV in a latent reservoir. Strategies to eradicate latent infection can only be evaluated with robust, sensitive and specific assays to quantitate reactivatable latent virus. We have taken the standard peripheral blood mononuclear cell (PBMC) based viral outgrowth methodology and from it created a logistically simpler and more highly reproducible assay to quantify replication-competent latent HIV in resting CD4+ T cells, both increasing accuracy and decreasing cost and labour. Purification of resting CD4+ T cells from whole PBMC is expedited and achieved in 3 hours, less than half the time of conventional protocols. Our indicator cell line, SupT1-CCR5 cells (a clonal cell line expressing CD4, CXCR4 and CCR5) provides a readily available standardised readout. Reproducibility compares favourably to other published assays but with reduced cost, labour and assay heterogeneity without compromising sensitivity. PMID:28233807

  6. Robust estimation of fractal measures for characterizing the structural complexity of the human brain: optimization and reproducibility.

    PubMed

    Goñi, Joaquín; Sporns, Olaf; Cheng, Hu; Aznárez-Sanado, Maite; Wang, Yang; Josa, Santiago; Arrondo, Gonzalo; Mathews, Vincent P; Hummer, Tom A; Kronenberger, William G; Avena-Koenigsberger, Andrea; Saykin, Andrew J; Pastor, María A

    2013-12-01

    High-resolution isotropic three-dimensional reconstructions of human brain gray and white matter structures can be characterized to quantify aspects of their shape, volume and topological complexity. In particular, methods based on fractal analysis have been applied in neuroimaging studies to quantify the structural complexity of the brain in both healthy and impaired conditions. The usefulness of such measures for characterizing individual differences in brain structure critically depends on their within-subject reproducibility in order to allow the robust detection of between-subject differences. This study analyzes key analytic parameters of three fractal-based methods that rely on the box-counting algorithm with the aim to maximize within-subject reproducibility of the fractal characterizations of different brain objects, including the pial surface, the cortical ribbon volume, the white matter volume and the gray matter/white matter boundary. Two separate datasets originating from different imaging centers were analyzed, comprising 50 subjects with three and 24 subjects with four successive scanning sessions per subject, respectively. The reproducibility of fractal measures was statistically assessed by computing their intra-class correlations. Results reveal differences between different fractal estimators and allow the identification of several parameters that are critical for high reproducibility. Highest reproducibility with intra-class correlations in the range of 0.9-0.95 is achieved with the correlation dimension. Further analyses of the fractal dimensions of parcellated cortical and subcortical gray matter regions suggest robustly estimated and region-specific patterns of individual variability. These results are valuable for defining appropriate parameter configurations when studying changes in fractal descriptors of human brain structure, for instance in studies of neurological diseases that do not allow repeated measurements or for disease

  7. Robust estimation of fractal measures for characterizing the structural complexity of the human brain: optimization and reproducibility

    PubMed Central

    Goñi, Joaquín; Sporns, Olaf; Cheng, Hu; Aznárez-Sanado, Maite; Wang, Yang; Josa, Santiago; Arrondo, Gonzalo; Mathews, Vincent P; Hummer, Tom A; Kronenberger, William G; Avena-Koenigsberger, Andrea; Saykin, Andrew J.; Pastor, María A.

    2013-01-01

    High-resolution isotropic three-dimensional reconstructions of human brain gray and white matter structures can be characterized to quantify aspects of their shape, volume and topological complexity. In particular, methods based on fractal analysis have been applied in neuroimaging studies to quantify the structural complexity of the brain in both healthy and impaired conditions. The usefulness of such measures for characterizing individual differences in brain structure critically depends on their within-subject reproducibility in order to allow the robust detection of between-subject differences. This study analyzes key analytic parameters of three fractal-based methods that rely on the box-counting algorithm with the aim to maximize within-subject reproducibility of the fractal characterizations of different brain objects, including the pial surface, the cortical ribbon volume, the white matter volume and the grey matter/white matter boundary. Two separate datasets originating from different imaging centers were analyzed, comprising, 50 subjects with three and 24 subjects with four successive scanning sessions per subject, respectively. The reproducibility of fractal measures was statistically assessed by computing their intra-class correlations. Results reveal differences between different fractal estimators and allow the identification of several parameters that are critical for high reproducibility. Highest reproducibility with intra-class correlations in the range of 0.9–0.95 is achieved with the correlation dimension. Further analyses of the fractal dimensions of parcellated cortical and subcortical gray matter regions suggest robustly estimated and region-specific patterns of individual variability. These results are valuable for defining appropriate parameter configurations when studying changes in fractal descriptors of human brain structure, for instance in studies of neurological diseases that do not allow repeated measurements or for disease

  8. Color accuracy and reproducibility in whole slide imaging scanners

    PubMed Central

    Shrestha, Prarthana; Hulsken, Bas

    2014-01-01

    Abstract We propose a workflow for color reproduction in whole slide imaging (WSI) scanners, such that the colors in the scanned images match to the actual slide color and the inter-scanner variation is minimum. We describe a new method of preparation and verification of the color phantom slide, consisting of a standard IT8-target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several International Color Consortium (ICC) compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color space. Based on the quality of the color reproduction in histopathology slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed workflow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We quantify color difference using the CIE-DeltaE2000 metric, where DeltaE values below 1 are considered imperceptible. Our evaluation on 14 phantom slides, manufactured according to the proposed method, shows an average inter-slide color difference below 1 DeltaE. The proposed workflow is implemented and evaluated in 35 WSI scanners developed at Philips, called the Ultra Fast Scanners (UFS). The color accuracy, measured as DeltaE between the scanner reproduced colors and the reference colorimetric values of the phantom patches, is improved on average to 3.5 DeltaE in calibrated scanners from 10 DeltaE in uncalibrated scanners. The average inter-scanner color difference is found to be 1.2 DeltaE. The improvement in color performance upon using the proposed method is apparent with the visual color quality of the tissue scans. PMID:26158041

  9. Development of a Consistent and Reproducible Porcine Scald Burn Model

    PubMed Central

    Kempf, Margit; Kimble, Roy; Cuttle, Leila

    2016-01-01

    There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. PMID:27612153

  10. Can atmospheric reanalysis datasets be used to reproduce flood characteristics?

    NASA Astrophysics Data System (ADS)

    Andreadis, K.; Schumann, G.; Stampoulis, D.

    2014-12-01

    Floods are one of the costliest natural disasters and the ability to understand their characteristics and their interactions with population, land cover and climate changes is of paramount importance. In order to accurately reproduce flood characteristics such as water inundation and heights both in the river channels and floodplains, hydrodynamic models are required. Most of these models operate at very high resolutions and are computationally very expensive, making their application over large areas very difficult. However, a need exists for such models to be applied at regional to global scales so that the effects of climate change with regards to flood risk can be examined. We use the LISFLOOD-FP hydrodynamic model to simulate a 40-year history of flood characteristics at the continental scale, particularly over Australia. LISFLOOD-FP is a 2-D hydrodynamic model that solves the approximate Saint-Venant equations at large scales (on the order of 1 km) using a sub-grid representation of the river channel. This implementation is part of an effort towards a global 1-km flood modeling framework that will allow the reconstruction of a long-term flood climatology. The components of this framework include a hydrologic model (the widely-used Variable Infiltration Capacity model) and a meteorological dataset that forces it. In order to extend the simulated flood climatology to 50-100 years in a consistent manner, reanalysis datasets have to be used. The objective of this study is the evaluation of multiple atmospheric reanalysis datasets (ERA, NCEP, MERRA, JRA) as inputs to the VIC/LISFLOOD-FP model. Comparisons of the simulated flood characteristics are made with both satellite observations of inundation and a benchmark simulation of LISFLOOD-FP being forced by observed flows. Finally, the implications of the availability of a global flood modeling framework for producing flood hazard maps and disseminating disaster information are discussed.

  11. A reproducible method to determine the meteoroid mass index

    NASA Astrophysics Data System (ADS)

    Pokorný, P.; Brown, P. G.

    2016-08-01

    Context. The determination of meteoroid mass indices is central to flux measurements and evolutionary studies of meteoroid populations. However, different authors use different approaches to fit observed data, making results difficult to reproduce and the resulting uncertainties difficult to justify. The real, physical, uncertainties are usually an order of magnitude higher than the reported values. Aims: We aim to develop a fully automated method that will measure meteoroid mass indices and associated uncertainty. We validate our method on large radar and optical datasets and compare results to obtain a best estimate of the true meteoroid mass index. Methods: Using MultiNest, a Bayesian inference tool that calculates the evidence and explores the parameter space, we search for the best fit of cumulative number vs. mass distributions in a four-dimensional space of variables (a,b,X1,X2). We explore biases in meteor echo distributions using optical meteor data as a calibration dataset to establish the systematic offset in measured mass index values. Results: Our best estimate for the average de-biased mass index for the sporadic meteoroid complex, as measured by radar appropriate to the mass range 10-3 > m > 10-5 g, was s = -2.10 ± 0.08. Optical data in the 10-1 > m > 10-3 g range, with the shower meteors removed, produced s = -2.08 ± 0.08. We find the mass index used by Grün et al. (1985) is substantially larger than we measure in the 10-4 < m < 10-1 g range. Our own code with a simple manual and a sample dataset can be found here: http://ftp://aquarid.physics.uwo.ca/pub/peter/MassIndexCode/

  12. Scan-rescan reproducibility of CT densitometric measures of emphysema

    NASA Astrophysics Data System (ADS)

    Chong, D.; van Rikxoort, E. M.; Kim, H. J.; Goldin, J. G.; Brown, M. S.

    2011-03-01

    This study investigated the reproducibility of HRCT densitometric measures of emphysema in patients scanned twice one week apart. 24 emphysema patients from a multicenter study were scanned at full inspiration (TLC) and expiration (RV), then again a week later for four scans total. Scans for each patient used the same scanner and protocol, except for tube current in three patients. Lung segmentation with gross airway removal was performed on the scans. Volume, weight, mean lung density (MLD), relative area under -950HU (RA-950), and 15th percentile (PD-15) were calculated for TLC, and volume and an airtrapping mask (RA-air) between -950 and -850HU for RV. For each measure, absolute differences were computed for each scan pair, and linear regression was performed against volume difference in a subgroup with volume difference <500mL. Two TLC scan pairs were excluded due to segmentation failure. The mean lung volumes were 5802 +/- 1420mL for TLC, 3878 +/- 1077mL for RV. The mean absolute differences were 169mL for TLC volume, 316mL for RV volume, 14.5g for weight, 5.0HU for MLD, 0.66p.p. for RA-950, 2.4HU for PD-15, and 3.1p.p. for RA-air. The <500mL subgroup had 20 scan pairs for TLC and RV. The R2 values were 0.8 for weight, 0.60 for MLD, 0.29 for RA-950, 0.31 for PD-15, and 0.64 for RA-air. Our results indicate that considerable variability exists in densitometric measures over one week that cannot be attributed to breathhold or physiology. This has implications for clinical trials relying on these measures to assess emphysema treatment efficacy.

  13. Crowdsourcing reproducible seizure forecasting in human and canine epilepsy

    PubMed Central

    Wagenaar, Joost; Abbot, Drew; Adkins, Phillip; Bosshard, Simone C.; Chen, Min; Tieng, Quang M.; He, Jialune; Muñoz-Almaraz, F. J.; Botella-Rocamora, Paloma; Pardo, Juan; Zamora-Martinez, Francisco; Hills, Michael; Wu, Wei; Korshunova, Iryna; Cukierski, Will; Vite, Charles; Patterson, Edward E.; Litt, Brian; Worrell, Gregory A.

    2016-01-01

    See Mormann and Andrzejak (doi:10.1093/brain/aww091) for a scientific commentary on this article.   Accurate forecasting of epileptic seizures has the potential to transform clinical epilepsy care. However, progress toward reliable seizure forecasting has been hampered by lack of open access to long duration recordings with an adequate number of seizures for investigators to rigorously compare algorithms and results. A seizure forecasting competition was conducted on kaggle.com using open access chronic ambulatory intracranial electroencephalography from five canines with naturally occurring epilepsy and two humans undergoing prolonged wide bandwidth intracranial electroencephalographic monitoring. Data were provided to participants as 10-min interictal and preictal clips, with approximately half of the 60 GB data bundle labelled (interictal/preictal) for algorithm training and half unlabelled for evaluation. The contestants developed custom algorithms and uploaded their classifications (interictal/preictal) for the unknown testing data, and a randomly selected 40% of data segments were scored and results broadcasted on a public leader board. The contest ran from August to November 2014, and 654 participants submitted 17 856 classifications of the unlabelled test data. The top performing entry scored 0.84 area under the classification curve. Following the contest, additional held-out unlabelled data clips were provided to the top 10 participants and they submitted classifications for the new unseen data. The resulting area under the classification curves were well above chance forecasting, but did show a mean 6.54 ± 2.45% (min, max: 0.30, 20.2) decline in performance. The kaggle.com model using open access data and algorithms generated reproducible research that advanced seizure forecasting. The overall performance from multiple contestants on unseen data was better than a random predictor, and demonstrates the feasibility of seizure forecasting in canine and

  14. Reproducing American Sign Language sentences: cognitive scaffolding in working memory

    PubMed Central

    Supalla, Ted; Hauser, Peter C.; Bavelier, Daphne

    2014-01-01

    The American Sign Language Sentence Reproduction Test (ASL-SRT) requires the precise reproduction of a series of ASL sentences increasing in complexity and length. Error analyses of such tasks provides insight into working memory and scaffolding processes. Data was collected from three groups expected to differ in fluency: deaf children, deaf adults and hearing adults, all users of ASL. Quantitative (correct/incorrect recall) and qualitative error analyses were performed. Percent correct on the reproduction task supports its sensitivity to fluency as test performance clearly differed across the three groups studied. A linguistic analysis of errors further documented differing strategies and bias across groups. Subjects' recall projected the affordance and constraints of deep linguistic representations to differing degrees, with subjects resorting to alternate processing strategies when they failed to recall the sentence correctly. A qualitative error analysis allows us to capture generalizations about the relationship between error pattern and the cognitive scaffolding, which governs the sentence reproduction process. Highly fluent signers and less-fluent signers share common chokepoints on particular words in sentences. However, they diverge in heuristic strategy. Fluent signers, when they make an error, tend to preserve semantic details while altering morpho-syntactic domains. They produce syntactically correct sentences with equivalent meaning to the to-be-reproduced one, but these are not verbatim reproductions of the original sentence. In contrast, less-fluent signers tend to use a more linear strategy, preserving lexical status and word ordering while omitting local inflections, and occasionally resorting to visuo-motoric imitation. Thus, whereas fluent signers readily use top-down scaffolding in their working memory, less fluent signers fail to do so. Implications for current models of working memory across spoken and signed modalities are considered. PMID

  15. [Our concept of defecography. Methods and reproducibility of results].

    PubMed

    Sutorý, M; Brhelová, H; Michek, J; Kubacák, J; Vasícková, J; Stursa, V; Sehnalová, H

    1999-06-01

    Defecography is used in the Czech Republic only exceptionally. Since 1988 the authors made 402 defecographic examinations. They submit a detailed description of hitherto assembled experience and their own modification of the examination. As contrast material they use at present Micropaque susp. thickened by means of wheat bran. They administer it by means of a modified press for dough preparation. The X-rays are taken on a modified ordinary stool made from soft timber. For screening of uncovered places in the visual field they use individually placed copper plates 2 mm thick. For better evaluation of the X-rays the authors place during examination an X-ray contrasting net behind the patient. Pictures are taken at rest, during contraction, during modified Valsalva's manoeuvre and during all stages of defecation. The authors mention the most interesting pathological pictures they encountered so far--internal prolapse, levator hernia, rectocele, sphincter defect, various forms of prolapses and dyskineses of the pelvic floor. In the authors opinion the basic quantifiable parameters are the magnitude of the anorectal angles. They used the assessment method described by Mahieu, as well as the mediorectal angle which in their opinion is a reflection of the patient's somatotype and levator function. More than the absolute values of the angles they emphasize the difference of the two angles and change of the latter during contraction and defecation. In their opinion enlargement of the difference during contraction and diminution to values close to zero is normal. Converse values are according to the authors evidence of dyssynergy of the pelvic floor. Independent assessment of the angles and magnitude of the lift of the pelvic floor by three subjects are subjected to statistical analysis. They provide evidence of complete reproducibility of results of anorectal angles according to the authors' definition. The results of assessment can be used to investigate relations with

  16. Carbon Nanotube Thin-Film Antennas.

    PubMed

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of <10 ohm/sq is needed to achieve a 10 dB return loss in the unbalanced antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

  17. A Multilayered Thin Film Insulator for Harsh Environments

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Blaha, Charles A.; Busfield, A. Rachel; Thomas, Valarie D.

    2002-01-01

    The status of work to develop a reliable high temperature dielectric thin film for use with thin film sensors is presented. The use of thin films to electrically insulate thin film sensors on engine components minimizes the intrusiveness of the sensor and allows a more accurate measurement of the environment. A variety of insulating films were investigated for preventing electrical shorting caused by insulator failure between the sensor and the component. By alternating layers of sputtered high temperature ceramics, a sequence of insulating layers was devised that prevents pinholes from forming completely through the insulator and maintains high electrical resistivity at high temperatures. The major technical challenge remaining is to optimize the fabrication of the insulator with respect to composition to achieve a reliable high temperature insulating film. Data from the testing of various potentially insulating thin film systems is presented and their application to thin film sensors is also discussed.

  18. Thin polymer film collectors as a contribution to the solar industry

    SciTech Connect

    Wilhelm, W.G.

    1984-06-01

    Achievements made in research on thin polymer film solar flat-plate collectors using monocoque construction techniques are briefly discussed. The significance of these achievements for cost reduction of flat-plate collectors without compromising performance is briefly discussed.

  19. Comparison and reproducibility of sEMG during manual muscle testing on land and in water.

    PubMed

    Silvers, W Matthew; Dolny, Dennis G

    2011-02-01

    The objectives of this study were to: (1) compare the sEMG recordings from maximal voluntary contractions (MVC), and (2) examine the reproducibility of sEMG recordings from MVCs for selected lower extremity muscles derived from manual muscle testing (MMT) on dry land, and in water prior to and following aquatic treadmill running. Twelve healthy recreational male runners participated. The selected muscles were: M. quadriceps-vastus medialis (VM) and rectus femoris (RF), M. biceps femoris (BF), M. tibialis anterior (TA) and the M. gastrocnemius caput mediale (GAS) of the right leg. The MVC testing conditions were: dry land, underwater prior to (Water 1) and following an aquatic exercise trial (Water 2). For each muscle, a one-way analysis of variance with repeated measures was used to compare MVC scores between testing conditions, and the intra-class correlation coefficient (ICC) and typical error (CV%) were calculated to determine the reproducibility and precision of MVC scores, respectively, between conditions. For all muscles, no significant differences were observed between land and water MVC scores (p=0.88-0.97), and high reliability (ICC=0.96-0.98) and precision (CV%=7.4-12.6%) were observed between MVC conditions. Under MMT conditions it appears that comparable MVC sEMG values were achieved on land and in water and the integrity of the EMG recordings were maintained during water immersion. Future studies using sEMG waterproofing procedures should conduct MVC testing in water for data normalization and perform post-exercise verification of sEMG signal integrity.

  20. Sharing meanings: developing interoperable semantic technologies to enhance reproducibility in earth and environmental science research

    NASA Astrophysics Data System (ADS)

    Schildhauer, M.

    2015-12-01

    Earth and environmental scientists are familiar with the entities, processes, and theories germane to their field of study, and comfortable collecting and analyzing data in their area of interest. Yet, while there appears to be consistency and agreement as to the scientific "terms" used to describe features in their data and analyses, aside from a few fundamental physical characteristics—such as mass or velocity-- there can be broad tolerances, if not considerable ambiguity, in how many earth science "terms" map to the underlying "concepts" that they actually represent. This ambiguity in meanings, or "semantics", creates major problems for scientific reproducibility. It greatly impedes the ability to replicate results—by making it difficult to determine the specifics of the intended meanings of terms such as deforestation or carbon flux -- as to scope, composition, magnitude, etc. In addition, semantic ambiguity complicates assemblage of comparable data for reproducing results, due to ambiguous or idiosyncratic labels for measurements, such as percent cover of forest, where the term "forest" is undefined; or where a reported output of "total carbon-emissions" might just include CO2 emissions, but not methane emissions. In this talk, we describe how the NSF-funded DataONE repository for earth and environmental science data (http://dataone.org), is using W3C-standard languages (RDF/OWL) to build an ontology for clarifying concepts embodied in heterogeneous data and model outputs. With an initial focus on carbon cycling concepts using terrestrial biospheric model outputs and LTER productivity data, we describe how we are achieving interoperability with "semantic vocabularies" (or ontologies) from aligned earth and life science domains, including OBO-foundry ontologies such as ENVO and BCO; the ISO/OGC O&M; and the NSF Earthcube GeoLink project. Our talk will also discuss best practices that may be helpful for other groups interested in constructing their own

  1. Elastohydrodynamic studies using thin film transducers

    NASA Astrophysics Data System (ADS)

    Safa, M. M. A.; MacPherson, P. B.

    1984-01-01

    Thin film microtransducers for application to the study of the variation of pressure, temperature, and oil film thickness in an elastohydrodynamically lubricated, nominal line contact were developed. Fabrication techniques were improved to enhance the useful life. Techniques to achieve higher resolution by reducing sensor size and improving the signal monitoring circuitry were developed. Material properties in thin film form used in fabricating the sensors were examined. Possible sources of errors in interpreting the results obtained from these devices were studied. Results under various operating conditions were compared with theoretical and experimental results, and reasonably good agreement is found.

  2. Thin glass processing with various laser sources

    NASA Astrophysics Data System (ADS)

    Collins, Adam R.; Milne, David; Prieto, Camilo; O'Connor, Gerard M.

    2015-03-01

    Laser processing of thin glass has proven problematic due to the inefficient coupling of optical energy into glass and the difficulty achieving an economical processing speed while maintaining cut quality. Laser glass processing is pertinent to touch screen display, microfluidic, microoptic and photovoltaic applications. The results of the laser scribing of 110 μm thick alkali free glass with various laser sources are presented. The laser sources include a CO₂ laser, nanosecond UV laser and femtosecond IR laser. The contrasting absorption mechanisms are discussed. Cut quality and processing speed are characterised using SEM and optical microscopy techniques. Alternative laser techniques for thin glass processing are also considered.

  3. Research Reproducibility in Longitudinal Multi-Center Studies Using Data from Electronic Health Records

    PubMed Central

    Zozus, Meredith N.; Richesson, Rachel L.; Walden, Anita; Tenenbaum, Jessie D.; Hammond, W.E.

    2016-01-01

    A fundamental premise of scientific research is that it should be reproducible. However, the specific requirements for reproducibility of research using electronic health record (EHR) data have not been sufficiently articulated. There is no guidance for researchers about how to assess a given project and identify provisions for reproducibility. We analyze three different clinical research initiatives that use EHR data in order to define a set of requirements to reproduce the research using the original or other datasets. We identify specific project features that drive these requirements. The resulting framework will support the much-needed discussion of strategies to ensure the reproducibility of research that uses data from EHRs. PMID:27570682

  4. Research Reproducibility in Longitudinal Multi-Center Studies Using Data from Electronic Health Records.

    PubMed

    Zozus, Meredith N; Richesson, Rachel L; Walden, Anita; Tenenbaum, Jessie D; Hammond, W E

    2016-01-01

    A fundamental premise of scientific research is that it should be reproducible. However, the specific requirements for reproducibility of research using electronic health record (EHR) data have not been sufficiently articulated. There is no guidance for researchers about how to assess a given project and identify provisions for reproducibility. We analyze three different clinical research initiatives that use EHR data in order to define a set of requirements to reproduce the research using the original or other datasets. We identify specific project features that drive these requirements. The resulting framework will support the much-needed discussion of strategies to ensure the reproducibility of research that uses data from EHRs.

  5. Achieving closure at Fernald

    SciTech Connect

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  6. Metal Induced Growth of Si Thin Films and NiSi Nanowires

    DTIC Science & Technology

    2010-02-25

    Zinc Oxide Over MIG Silicon- We have been studying the formation of ZnO films by RF sputtering. Part of this study deals with...about 50 nm. 15. SUBJECT TERMS Thin film silicon, solar cells, thin film transistors , nanowires, metal induced growth 16. SECURITY CLASSIFICATION...to achieve, µc-Si is more desirable than a-Si due to its increased mobility. Thin film µc-Si is also a popular material for thin film transistors

  7. Mechanics of Thin Films

    DTIC Science & Technology

    1992-02-06

    S. Hwang, Thermal conductivity of thin films: measurement and microstructural effects, in Thin- film heat transfer, properties and processing, ed...thermal, electrical, optical and magnetic properties . As typical examples we mention microelectronics, optical coatings and multilayers for use in optical...interplay between mechanical properties (elastic moduli), thermal properties (thermal conductivity, thermal expansion coefficient), and optical

  8. Evaluation of mammographic density patterns: reproducibility and concordance among scales

    PubMed Central

    2010-01-01

    this percentage was lower for the quantitative scales (21.89% for BI-RADS and 21.86% for Boyd). Conclusions Visual scales of mammographic density show a high reproducibility when appropriate training is provided. Their ability to distinguish between high and low risk render them useful for routine use by breast cancer screening programs. Quantitative-based scales are more specific than pattern-based scales in classifying populations in the high-risk group. PMID:20836850

  9. Assay Reproducibility in Clinical Studies of Plasma miRNA

    PubMed Central

    Rice, Jonathan; Roberts, Henry; Burton, James; Pan, Jianmin; States, Vanessa; Rai, Shesh N.; Galandiuk, Susan

    2015-01-01

    There are increasing reports of plasma miRNAs as biomarkers of human disease but few standards in methodologic reporting, leading to inconsistent data. We systematically reviewed plasma miRNA studies published between July 2013-June 2014 to assess methodology. Six parameters were investigated: time to plasma extraction, methods of RNA extraction, type of miRNA, quantification, cycle threshold (Ct) setting, and methods of statistical analysis. We compared these data with a proposed standard methodologic technique. Beginning with initial screening for 380 miRNAs using microfluidic array technology and validation in an additional cohort of patients, we compared 11 miRNAs that exhibited differential expression between 16 patients with benign colorectal neoplasms (advanced adenomas) and 16 patients without any neoplasm (controls). Plasma was isolated immediately, 12, 24, 48, or 72 h following phlebotomy. miRNA was extracted using two different techniques (Trizol LS with pre-amplification or modified miRNeasy). We performed Taqman-based RT-PCR assays for the 11 miRNAs with subsequent analyses using a variable Ct setting or a fixed Ct set at 0.01, 0.03, 0.05, or 0.5. Assays were performed in duplicate by two different operators. RNU6 was the internal reference. Systematic review yielded 74 manuscripts meeting inclusion criteria. One manuscript (1.4%) documented all 6 methodological parameters, while < 5% of studies listed Ct setting. In our proposed standard technique, plasma extraction ≤12 h provided consistent ΔCt. miRNeasy extraction yielded higher miRNA concentrations and fewer non-expressed miRNAs compared to Trizol LS (1/704 miRNAs [0.14%] vs 109/704 miRNAs [15%], not expressed, respectively). A fixed Ct bar setting of 0.03 yielded the most reproducible data, provided that <10% miRNA were non-expressed. There was no significant intra-operator variability. There was significant inter-operator variation using Trizol LS extraction, while this was negligible using

  10. Achievement Goals and Achievement Emotions: A Meta-Analysis

    ERIC Educational Resources Information Center

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  11. Performance Characterization of Monolithic Thin Film Resistors

    NASA Astrophysics Data System (ADS)

    Yin, Rong

    Thin film resistors have a large resistance range and stable performance under high temperature operating condition. Thin film resistors trimmed by laser beam are able to achieve very high precision on resistance value. As a result, thin film resistors have been widely used to improve the performance of integrated circuits such as operational amplifier, analog-to-digital (A/D) and digital -to-analog (D/A) converters, etc. In this dissertation, a new class of thin film resistors, silicon chrome (SiCr) thin film resistors, has been investigated at length. From thin film characterization to aging behavior modelling, we have carried out a series of engineering activities. The characteristics of the SiCr thin film incorporated into three bipolar processes were first determined. After laser trimming, we have measured a couple of physical parameters of the SiCr film in the heat affected zone (HAZ). This is the first time the sheet resistance and the temperature coefficient of resistance (TCR) of thin film in the HAZ have been characterized. Both thermal and d.c. load accelerated aging tests were performed. The test structures were subjected to the aging for 1000 hours. Based on the test data, we not only evaluated the classical thermal aging model for untrimmed thin film resistors, but also established several empirical thermal aging models for trimmed resistors and d.c. load aging models for both trimmed and untrimmed thin film resistors. All the experiments were carried out for both conventional bar resistors and our new Swiss Cheese (SC) resistors. For the first time, the performance of laser trimmed SC resistors, which was experimentally evaluated, shown a clear superiority over that of trimmed bar resistors. Besides these experiments, we have examined different die attach techniques and their effects on thin film resistors. Also, we have developed a number of hardware systems and software tools, such as a temperature controller, d.c. current source, temperature

  12. Reproducible Ultrahigh SERS Enhancement in Single Deterministic Hotspots Using Nanosphere-Plane Antennas Under Radially Polarized Excitation

    NASA Astrophysics Data System (ADS)

    Long, Jing; Yi, Hui; Li, Hongquan; Lei, Zeyu; Yang, Tian

    2016-09-01

    Surface enhanced Raman scattering (SERS) in a nanometer size hotspot has empowered the investigation of chemical structures and dynamic behaviors of one and a few molecules. However, further advancement is hindered by lack of large enough yet reproducible enhancement in single deterministic hotspots. To resolve this problem, here we introduce a nanosphere-plane antenna under radially polarized laser excitation experiment, which provides an electromagnetic enhancement of 109~10 at the gap of each individual nanosphere-plane antenna and a root-mean-square error down to 100.08 between them. The experiment also reveals a nonlinear SERS behavior with less than one plasmon, which is also observed within a single hotspot. The unprecedented simultaneous achievement of ultrahigh enhancement and reproducibility in deterministic individual hotspots is attributed to the combination of a well-controlled hotspot geometry, the efficient coupling between vertical antenna and laser which produces orders of magnitude higher enhancement than previous excitation methods, and low power operation which is critical for high reproducibility. Our method opens a path for systematic studies on single and few molecule SERS and their surface chemistry in an in-situ and well-controlled manner.

  13. Reproducible Ultrahigh SERS Enhancement in Single Deterministic Hotspots Using Nanosphere-Plane Antennas Under Radially Polarized Excitation

    PubMed Central

    Long, Jing; Yi, Hui; Li, Hongquan; Lei, Zeyu; Yang, Tian

    2016-01-01

    Surface enhanced Raman scattering (SERS) in a nanometer size hotspot has empowered the investigation of chemical structures and dynamic behaviors of one and a few molecules. However, further advancement is hindered by lack of large enough yet reproducible enhancement in single deterministic hotspots. To resolve this problem, here we introduce a nanosphere-plane antenna under radially polarized laser excitation experiment, which provides an electromagnetic enhancement of 109~10 at the gap of each individual nanosphere-plane antenna and a root-mean-square error down to 100.08 between them. The experiment also reveals a nonlinear SERS behavior with less than one plasmon, which is also observed within a single hotspot. The unprecedented simultaneous achievement of ultrahigh enhancement and reproducibility in deterministic individual hotspots is attributed to the combination of a well-controlled hotspot geometry, the efficient coupling between vertical antenna and laser which produces orders of magnitude higher enhancement than previous excitation methods, and low power operation which is critical for high reproducibility. Our method opens a path for systematic studies on single and few molecule SERS and their surface chemistry in an in-situ and well-controlled manner. PMID:27621109

  14. Method for synthesizing thin film electrodes

    DOEpatents

    Boyle, Timothy J.

    2007-03-13

    A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

  15. Prognostic Value and Reproducibility of Pretreatment CT Texture Features in Stage III Non-Small Cell Lung Cancer

    SciTech Connect

    Fried, David V.; Tucker, Susan L.; Zhou, Shouhao; Liao, Zhongxing; Mawlawi, Osama; Ibbott, Geoffrey; Court, Laurence E.

    2014-11-15

    .8% (±3.9% SD) classification reproducibility in terms of OS, LRC, and FFDM, respectively. Conclusions: Pretreatment tumor texture may provide prognostic information beyond that obtained from CPFs. Models incorporating feature reproducibility achieved classification rates of ∼80%. External validation would be required to establish texture as a prognostic factor.

  16. Optical diffraction analysis of petrographic thin sections.

    PubMed

    Power, P C; Pincus, H J

    1974-10-18

    Diffraction patterns that are highly reproducible, of useful quality, and consistent with the input generating them can be easily obtained with a microscope system. The input can be either a reduced photograph or a thin section. With two exceptions, the relationships between a thin section and its diffraction pattern produced by a petrographic microscope are the same as the relationships between a photographic input and its diffraction pattern produced by a conventional ODA system. The exceptions are that the diffraction patterns generated directly by the thin sections may be asymmetrical or, if the thin section is sufficiently heterogeneous, may be smeared. The microscope system is generally more useful than a conventional ODA system for the analysis of microfabric in thin sections. One can readily use the microscope system to analyze elements of widely varying spatial frequency simply by changing the objectives. The diffraction patterns can be magnified by changing to a higherpower ocular. In most cases the microscope-generated diffraction pattern transmits the useful spatial information in the thin section more completely than the conventionally produced diffraction pattern; the photographic inputs for the conventionally produced diffraction pattern emphasize lower-frequency spatial information. This property, combined with the microscope system's better response to twinning, makes the microscope more sensitive to commonly used microfabric elements. For the analysis of thin sections, a conventional ODA system is superior to the microscope system in only three cases. First, if one wants to analyze the entire thin section at one time, a conventional system must be used with a photographic input of the thin section. Second, if the thin section is extremely heterogeneous (crystallographically or mineralogically), the microscope-generated diffraction pattern may exhibit gross smearing even with the highestpower objectives available. Finally, the thin section may

  17. Reproducibility of 24-h post-exercise changes in energy intake in overweight and obese women using current methodology.

    PubMed

    Brown, Gemma L; Lean, Michael E; Hankey, Catherine R

    2012-07-01

    Direct observation(s) of energy intake (EI) via buffet meals served in the laboratory are often carried out within short-term exercise intervention studies. The reproducibility of values obtained has not been assessed either under resting control conditions or post-exercise, in overweight and obese females. A total of fourteen sedentary, pre-menopausal females (BMI 30.0 (SD 5.1) kg/m²) completed four trials; two exercise and two control. Each trial lasted 24 h spanning over 2 d; conducted from afternoon on day 1 and morning on day 2. An exercise session to expend 1.65 MJ was completed on day 1 of exercise trials, and three buffet meals were served during each trial. Reproducibility of post-exercise changes in energy and macronutrient intakes was assessed at each individual buffet meal by intraclass correlation coefficient (r(i)). Only the r(i) values for post-exercise changes in energy (r(i) 0.44 (95 % CI - 0.03, 0.77), P = 0.03) and fat intake (r(i) 0.51 (95 % CI 0.04, 0.81), P = 0.02) at the lunch buffet meal achieved statistical significance; however, these r i values were weak and had large associated 95 % CI, which indicates a large degree of variability associated with these measurements. Energy and macronutrient intakes at the breakfast and evening buffet meals were not reproducible. This study concludes that the frequently used laboratory-based buffet meal method of assessing EI does not produce reliable, reproducible post-exercise changes in EI in overweight and obese women.

  18. Electrochemical thinning of silicon

    DOEpatents

    Medernach, J.W.

    1994-01-11

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR). 14 figures.

  19. Electrochemical thinning of silicon

    DOEpatents

    Medernach, John W.

    1994-01-01

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR).

  20. Biomimetic thin film synthesis

    SciTech Connect

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  1. Thin film hydrogen sensor

    DOEpatents

    Cheng, Yang-Tse; Poli, Andrea A.; Meltser, Mark Alexander

    1999-01-01

    A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

  2. Thin film hydrogen sensor

    DOEpatents

    Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

    1999-03-23

    A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

  3. Quantum theory as the most robust description of reproducible experiments

    NASA Astrophysics Data System (ADS)

    De Raedt, Hans; Katsnelson, Mikhail I.; Michielsen, Kristel

    2014-08-01

    knowledge always starts from the middle, that is, from the world of macroscopic objects. According to Bohr, the quantum theoretical description crucially depends on the existence of macroscopic objects which can be used as measuring devices. For an extensive analysis of the quantum measurement process from a dynamical point of view see Ref. [51]. Most importantly, the description of the macroscopic level is robust, that is, essentially independent of the underlying "more fundamental" picture [2]. As will be seen later, formalizing the notion of "robustness" is key to derive the basic equations of quantum theory from the general framework of logical inference.Key assumptions of the deductive approach are that the mathematical description is a complete description of the experiment under consideration and that there is no uncertainty about the conditions under which the experiment is carried out. If the theory does not fully account for all the relevant aspects of the phenomenon that we wish to describe, the general rules by which we deduce whether a proposition is true or false can no longer be used. However, in these circumstances, we can still resort to logical inference [37-41] to find useful answers to unambiguous questions. Of course, in general it will no longer be possible to say whether a proposition is true or false, hence there will always remain a residue of doubt. However, as will be shown, the description obtained through logical inference may also be unambiguous and independent of the individual.In the present paper, we demonstrate that the basic equations of quantum theory directly follow from logical inference applied to experiments in which there is uncertainty about individual events, the stringent condition that certain properties of the collection of events are reproducible, meaning that they are robust with respect to small changes in the conditions under which the experiments are carried out.

  4. Repeatability and reproducibility of intracellular molar concentration assessed by synchrotron-based x-ray fluorescence microscopy

    SciTech Connect

    Merolle, L. Gianoncelli, A.; Malucelli, E. Cappadone, C.; Farruggia, G.; Sargenti, A.; Procopio, A.; Fratini, M.; Notargiacomo, A.; Lombardo, M.; Lagomarsino, S.; Iotti, S.

    2016-01-28

    Elemental analysis of biological sample can give information about content and distribution of elements essential for human life or trace elements whose absence is the cause of abnormal biological function or development. However, biological systems contain an ensemble of cells with heterogeneous chemistry and elemental content; therefore, accurate characterization of samples with high cellular heterogeneity may only be achieved by analyzing single cells. Powerful methods in molecular biology are abundant, among them X-Ray microscopy based on synchrotron light source has gaining increasing attention thanks to its extremely sensitivity. However, reproducibility and repeatability of these measurements is one of the major obstacles in achieving a statistical significance in single cells population analysis. In this study, we compared the elemental content of human colon adenocarcinoma cells obtained by three distinct accesses to synchrotron radiation light.

  5. Repeatability and reproducibility of intracellular molar concentration assessed by synchrotron-based x-ray fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Merolle, L.; Malucelli, E.; Fratini, M.; Gianoncelli, A.; Notargiacomo, A.; Cappadone, C.; Farruggia, G.; Sargenti, A.; Procopio, A.; Lombardo, M.; Lagomarsino, S.; Iotti, S.

    2016-01-01

    Elemental analysis of biological sample can give information about content and distribution of elements essential for human life or trace elements whose absence is the cause of abnormal biological function or development. However, biological systems contain an ensemble of cells with heterogeneous chemistry and elemental content; therefore, accurate characterization of samples with high cellular heterogeneity may only be achieved by analyzing single cells. Powerful methods in molecular biology are abundant, among them X-Ray microscopy based on synchrotron light source has gaining increasing attention thanks to its extremely sensitivity. However, reproducibility and repeatability of these measurements is one of the major obstacles in achieving a statistical significance in single cells population analysis. In this study, we compared the elemental content of human colon adenocarcinoma cells obtained by three distinct accesses to synchrotron radiation light.

  6. Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing

    PubMed Central

    Troia, Benedetto; Khokhar, Ali Z.; Nedeljkovic, Milos; Reynolds, Scott A.; Hu, Youfang; Mashanovich, Goran Z.; Passaro, Vittorio M. N.

    2015-01-01

    In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved. PMID:26067193

  7. On Quantile Regression in Reproducing Kernel Hilbert Spaces with Data Sparsity Constraint.

    PubMed

    Zhang, Chong; Liu, Yufeng; Wu, Yichao

    2016-04-01

    For spline regressions, it is well known that the choice of knots is crucial for the performance of the estimator. As a general learning framework covering the smoothing splines, learning in a Reproducing Kernel Hilbert Space (RKHS) has a similar issue. However, the selection of training data points for kernel functions in the RKHS representation has not been carefully studied in the literature. In this paper we study quantile regression as an example of learning in a RKHS. In this case, the regular squared norm penalty does not perform training data selection. We propose a data sparsity constraint that imposes thresholding on the kernel function coefficients to achieve a sparse kernel function representation. We demonstrate that the proposed data sparsity method can have competitive prediction performance for certain situations, and have comparable performance in other cases compared to that of the traditional squared norm penalty. Therefore, the data sparsity method can serve as a competitive alternative to the squared norm penalty method. Some theoretical properties of our proposed method using the data sparsity constraint are obtained. Both simulated and real data sets are used to demonstrate the usefulness of our data sparsity constraint.

  8. Using Make for Reproducible and Parallel Neuroimaging Workflow and Quality-Assurance

    PubMed Central

    Askren, Mary K.; McAllister-Day, Trevor K.; Koh, Natalie; Mestre, Zoé; Dines, Jennifer N.; Korman, Benjamin A.; Melhorn, Susan J.; Peterson, Daniel J.; Peverill, Matthew; Qin, Xiaoyan; Rane, Swati D.; Reilly, Melissa A.; Reiter, Maya A.; Sambrook, Kelly A.; Woelfer, Karl A.; Grabowski, Thomas J.; Madhyastha, Tara M.

    2016-01-01

    The contribution of this paper is to describe how we can program neuroimaging workflow using Make, a software development tool designed for describing how to build executables from source files. A makefile (or a file of instructions for Make) consists of a set of rules that create or update target files if they have not been modified since their dependencies were last modified. These rules are processed to create a directed acyclic dependency graph that allows multiple entry points from which to execute the workflow. We show that using Make we can achieve many of the features of more sophisticated neuroimaging pipeline systems, including reproducibility, parallelization, fault tolerance, and quality assurance reports. We suggest that Make permits a large step toward these features with only a modest increase in programming demands over shell scripts. This approach reduces the technical skill and time required to write, debug, and maintain neuroimaging workflows in a dynamic environment, where pipelines are often modified to accommodate new best practices or to study the effect of alternative preprocessing steps, and where the underlying packages change frequently. This paper has a comprehensive accompanying manual with lab practicals and examples (see Supplemental Materials) and all data, scripts, and makefiles necessary to run the practicals and examples are available in the “makepipelines” project at NITRC. PMID:26869916

  9. Highly sensitive and reproducible silicon-based surface-enhanced Raman scattering sensors for real applications.

    PubMed

    Wang, Houyu; Jiang, Xiangxu; He, Yao

    2016-08-15

    During the past few decades, thanks to silicon nanomaterials' outstanding electronic/optical/mechanical properties, large surface-to-volume ratio, abundant surface chemistry, facile tailorability and good compatibility with modern semiconductor industry, different dimensional silicon nanostructures have been widely employed for rationally designing and fabricating high-performance surface-enhanced Raman scattering (SERS) sensors for the detection of various chemical and biological species. Among these, two-dimensional silicon nanostructures made of metal nanoparticle-modified silicon wafers and three-dimensional silicon nanostructures made of metal nanoparticle-decorated SiNW arrays are of particular interest, and have been extensively exploited as promising silicon-based SERS-active substrates for the construction of high-performance SERS sensors. With an aim to retrospect these important and exciting achievements, we herein focus on reviewing recent representative studies on silicon-based SERS sensors for sensing applications from a broad perspective and possible future direction, promoting readers' awareness of these novel powerful silicon-based SERS sensing technologies. Firstly, we summarize the two unique merits of silicon-based SERS sensors, and those are high sensitivity and good reproducibility. Next, we present recent advances of two- and three-dimensional silicon-based SERS sensors, especially for real applications. Finally, we discuss the major challenges and prospects for the development of silicon-based SERS sensors.

  10. Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing.

    PubMed

    Troia, Benedetto; Khokhar, Ali Z; Nedeljkovic, Milos; Reynolds, Scott A; Hu, Youfang; Mashanovich, Goran Z; Passaro, Vittorio M N

    2015-06-10

    In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved.

  11. Expression microarray reproducibility is improved by optimising purification steps in RNA amplification and labelling

    PubMed Central

    Naderi, Ali; Ahmed, Ahmed A; Barbosa-Morais, Nuno L; Aparicio, Samuel; Brenton, James D; Caldas, Carlos

    2004-01-01

    Background Expression microarrays have evolved into a powerful tool with great potential for clinical application and therefore reliability of data is essential. RNA amplification is used when the amount of starting material is scarce, as is frequently the case with clinical samples. Purification steps are critical in RNA amplification and labelling protocols, and there is a lack of sufficient data to validate and optimise the process. Results Here the purification steps involved in the protocol for indirect labelling of amplified RNA are evaluated and the experimentally determined best method for each step with respect to yield, purity, size distribution of the transcripts, and dye coupling is used to generate targets tested in replicate hybridisations. DNase treatment of diluted total RNA samples followed by phenol extraction is the optimal way to remove genomic DNA contamination. Purification of double-stranded cDNA is best achieved by phenol extraction followed by isopropanol precipitation at room temperature. Extraction with guanidinium-phenol and Lithium Chloride precipitation are the optimal methods for purification of amplified RNA and labelled aRNA respectively. Conclusion This protocol provides targets that generate highly reproducible microarray data with good representation of transcripts across the size spectrum and a coefficient of repeatability significantly better than that reported previously. PMID:15005798

  12. On Quantile Regression in Reproducing Kernel Hilbert Spaces with Data Sparsity Constraint

    PubMed Central

    Zhang, Chong; Liu, Yufeng; Wu, Yichao

    2015-01-01

    For spline regressions, it is well known that the choice of knots is crucial for the performance of the estimator. As a general learning framework covering the smoothing splines, learning in a Reproducing Kernel Hilbert Space (RKHS) has a similar issue. However, the selection of training data points for kernel functions in the RKHS representation has not been carefully studied in the literature. In this paper we study quantile regression as an example of learning in a RKHS. In this case, the regular squared norm penalty does not perform training data selection. We propose a data sparsity constraint that imposes thresholding on the kernel function coefficients to achieve a sparse kernel function representation. We demonstrate that the proposed data sparsity method can have competitive prediction performance for certain situations, and have comparable performance in other cases compared to that of the traditional squared norm penalty. Therefore, the data sparsity method can serve as a competitive alternative to the squared norm penalty method. Some theoretical properties of our proposed method using the data sparsity constraint are obtained. Both simulated and real data sets are used to demonstrate the usefulness of our data sparsity constraint. PMID:27134575

  13. Ceramic Composite Thin Films

    NASA Technical Reports Server (NTRS)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  14. Super Thin Ceramic Coatings

    NASA Video Gallery

    New technology being developed at NASA's Glenn Research Center creates super thin ceramic coatings on engine components. The Plasma Spray – Physical Vapor Deposition (PS-PVD) rig uses a powerful ...

  15. Enrichment of the finite element method with reproducing kernel particle method

    SciTech Connect

    Chen, Y.; Liu, W.K.; Uras, R.A.

    1995-07-01

    Based on the reproducing kernel particle method on enrichment procedure is introduced to enhance the effectiveness of the finite element method. The basic concepts for the reproducing kernel particle method are briefly reviewed. By adopting the well-known completeness requirements, a generalized form of the reproducing kernel particle method is developed. Through a combination of these two methods their unique advantages can be utilized. An alternative approach, the multiple field method is also introduced.

  16. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  17. Multifunctional thin film surface

    DOEpatents

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  18. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  19. Plasma deposition of organic thin films: Control of film chemistry

    SciTech Connect

    Ratner, B.D.

    1993-12-31

    Plasma deposition of thin, polymeric films represent a versatile surface modification technology. Although these thin films are exploited for many applications, complaints heard about plasma deposited films are that their structures are uncharacterizable, that organic functionality is lost in their production and that reproducibility is difficult. Recently, new methods for film production, reactor control and surface characterization have led to well characterized plasma deposited thin polymeric films (PDTPF) with defined structure and organic functionality. Such PDTPF often closely resemble conventionally prepared homopolymers. Methods that can be used to control the chemistry of PDTPF are the minimization of the plasma power, pulsing the RF field to reduce the {open_quotes}plasma on{close_quotes} time, use of a Faraday cage to reduce electron bombardment, positioning the sample downfield from the glow zone, the use of monomers containing polymerizable double bonds and the use of a cold substrate to condense vapor simultaneously with plasma deposition.

  20. Magnetic Phases of Sputter Deposited Thin-Film Erbium

    PubMed Central

    Witt, J. D. S.; Cooper, J. F. K.; Satchell, N.; Kinane, C. J.; Curran, P. J.; Bending, S. J.; Langridge, S.; Heyderman, L. J.; Burnell, G.

    2016-01-01

    We present a detailed structural and magnetic characterization of sputter deposited thin film erbium, determined by x-ray diffraction, transport measurements, magnetometry and neutron diffraction. This provides information on the onset and change of the magnetic state as a function of temperature and applied magnetic field. Many of the features of bulk material are reproduced. Also of interest is the identification of a conical magnetic state which repeats with a wavevector parallel to the c axis τc = 4/17 in units of the reciprocal lattice parameter c*, which is a state not observed in any other thin film or bulk measurements. The data from the various techniques are combined to construct magnetic field, temperature (H, T)–phase diagrams for the 200 nm-thick Er sample that serves as a foundation for future exploitation of this complex magnetic thin film system. PMID:27966662

  1. Magnetic Phases of Sputter Deposited Thin-Film Erbium

    NASA Astrophysics Data System (ADS)

    Witt, J. D. S.; Cooper, J. F. K.; Satchell, N.; Kinane, C. J.; Curran, P. J.; Bending, S. J.; Langridge, S.; Heyderman, L. J.; Burnell, G.

    2016-12-01

    We present a detailed structural and magnetic characterization of sputter deposited thin film erbium, determined by x-ray diffraction, transport measurements, magnetometry and neutron diffraction. This provides information on the onset and change of the magnetic state as a function of temperature and applied magnetic field. Many of the features of bulk material are reproduced. Also of interest is the identification of a conical magnetic state which repeats with a wavevector parallel to the c axis τc = 4/17 in units of the reciprocal lattice parameter c*, which is a state not observed in any other thin film or bulk measurements. The data from the various techniques are combined to construct magnetic field, temperature (H, T)–phase diagrams for the 200 nm-thick Er sample that serves as a foundation for future exploitation of this complex magnetic thin film system.

  2. Lifting Minority Achievement: Complex Answers. The Achievement Gap.

    ERIC Educational Resources Information Center

    Viadero, Debra; Johnston, Robert C.

    2000-01-01

    This fourth in a four-part series on why academic achievement gaps exist describes the Minority Achievement Committee scholars program at Shaker Heights High School in Cleveland, Ohio, a powerful antidote to the achievement gap between minority and white and Asian American students. It explains the need to break down stereotypes about academic…

  3. Achievement Motivation of Women: Effects of Achievement and Affiliation Arousal.

    ERIC Educational Resources Information Center

    Gama, Elizabeth Maria Pinheiro

    1985-01-01

    Assigned 139 Brazilian women to neutral, affiliation arousal, and achievement arousal conditions based on their levels of achievement (Ach) and affiliative (Aff) needs. Results of story analyses revealed that achievement arousal increased scores of high Ach subjects and that high Aff subjects obtained higher scores than low Aff subjects. (BL)

  4. Attitude Towards Physics and Additional Mathematics Achievement Towards Physics Achievement

    ERIC Educational Resources Information Center

    Veloo, Arsaythamby; Nor, Rahimah; Khalid, Rozalina

    2015-01-01

    The purpose of this research is to identify the difference in students' attitude towards Physics and Additional Mathematics achievement based on gender and relationship between attitudinal variables towards Physics and Additional Mathematics achievement with achievement in Physics. This research focused on six variables, which is attitude towards…

  5. The Impact of Reading Achievement on Overall Academic Achievement

    ERIC Educational Resources Information Center

    Churchwell, Dawn Earheart

    2009-01-01

    This study examined the relationship between reading achievement and achievement in other subject areas. The purpose of this study was to determine if there was a correlation between reading scores as measured by the Standardized Test for the Assessment of Reading (STAR) and academic achievement in language arts, math, science, and social studies…

  6. Thin-Film Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Lowe, Roland A.

    1993-01-01

    Direct conversion of thermal energy into electrical energy using a photovoltaic cell is called thermophotovoltaic energy conversion. One way to make this an efficient process is to have the thermal energy source be an efficient selective emitter of radiation. The emission must be near the band-gap energy of the photovoltaic cell. One possible method to achieve an efficient selective emitter is the use of a thin film of rare-earth oxides. The determination of the efficiency of such an emitter requires analysis of the spectral emittance of the thin film including scattering and reflectance at the vacuum-film and film-substrate interfaces. Emitter efficiencies (power emitted in emission band/total emitted power) in the range 0.35-0.7 are predicted. There is an optimum optical depth to obtain maximum efficiency. High emitter efficiencies are attained only for low (less than 0.05) substrate emittance values, both with and without scattering. The low substrate emittance required for high efficiency limits the choice of substrate materials to highly reflective metals or high-transmission materials such as sapphire.

  7. Structures for dense, crack free thin films

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2011-03-08

    The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

  8. Visible light laser voltage probing on thinned substrates

    DOEpatents

    Beutler, Joshua; Clement, John Joseph; Miller, Mary A.; Stevens, Jeffrey; Cole, Jr., Edward I.

    2017-03-21

    The various technologies presented herein relate to utilizing visible light in conjunction with a thinned structure to enable characterization of operation of one or more features included in an integrated circuit (IC). Short wavelength illumination (e.g., visible light) is applied to thinned samples (e.g., ultra-thinned samples) to achieve a spatial resolution for laser voltage probing (LVP) analysis to be performed on smaller technology node silicon-on-insulator (SOI) and bulk devices. Thinning of a semiconductor material included in the IC (e.g., backside material) can be controlled such that the thinned semiconductor material has sufficient thickness to enable operation of one or more features comprising the IC during LVP investigation.

  9. Tailoring Thin Film-Lacquer Coatings for Space Application

    NASA Technical Reports Server (NTRS)

    Peters, Wanda C.; Harris, George; Miller, Grace; Petro, John

    1998-01-01

    Thin film coatings have the capability of obtaining a wide range of thermal radiative properties, but the development of thin film coatings can sometimes be difficult and costly when trying to achieve highly specular surfaces. Given any space mission's thermal control requirements, there is often a need for a variation of solar absorptance (Alpha(s)), emittance (epsilon) and/or highly specular surfaces. The utilization of thin film coatings is one process of choice for meeting challenging thermal control requirements because of its ability to provide a wide variety of Alpha(s)/epsilon ratios. Thin film coatings' radiative properties can be tailored to meet specific thermal control requirements through the use of different metals and the variation of dielectric layer thickness. Surface coatings can be spectrally selective to enhance radiative coupling and decoupling. The application of lacquer to a surface can also provide suitable specularity for thin film application without the cost and difficulty associated with polishing.

  10. Achievements in Stratospheric Ozone Protection

    EPA Pesticide Factsheets

    This report describes achievements in protecting the ozone layer, the benefits of these achievements, and strategies involved (e.g., using alternatives to ozone-depleting substances, phasing out harmful substances, and creating partnerships).

  11. Venusian Polar Vortex reproduced in an Atmospheric General Circulation Model

    NASA Astrophysics Data System (ADS)

    Ando, Hiroki; Imamura, Takeshi; Takagi, Masahiro; Sugimoto, Norihiko; Kashimura, Hiroki

    for the truncation wavenumber. The coefficient of the vertical eddy diffusion is 0.15 m (2) s (-1) . A fast zonal wind in a solid-body rotation and the temperature field that balances with the zonal wind (gradient wind balance) is given as the initial state. Time integrations are performed until the solution achieves a statistically steady state. In this study we analyzed the data of 300 days of the last from getting to the quasi-steady state. The temporal and zonal mean wind and temperature fields are almost consistent with those obtained in previous studies (e.g., Kouyama et al. 2012; Tellmann et al. 2009). Barotropic or baroclinic instability occurs at the polar region, and zonal wavenumber one component is the most dominant in the polar vortex, followed by wavenumber two. It rotates the pole with the period of 4-5 days. These features are almost consistent with recent measurements (e.g. Lopez et al. 2013). We also calculated the potential vorticity distribution and found that it sometimes shows the filament structure, which is similar to the cloud morphology observed in recent imaging measurements (e.g. Piccioni et al. 2006). The vertical structure of each zonal wavenumber component has the common feature that the phase stands upright within the polar vortex and seems to shift at the top of the neutral stable layer. In this presentation, we will also compare the vertical structure seen in our calculation with that examined by radio occultation measurements in Venus Express mission.

  12. Thin film adhesion by nanoindentation-induced superlayers. Final report

    SciTech Connect

    Gerberich, William W.; Volinsky, A.A.

    2001-06-01

    This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

  13. In vivo reproducibility of robotic probe placement for an integrated US-CT image-guided radiation therapy system

    NASA Astrophysics Data System (ADS)

    Lediju Bell, Muyinatu A.; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter; Wong, John

    2014-03-01

    Radiation therapy is used to treat cancer by delivering high-dose radiation to a pre-defined target volume. Ultrasound (US) has the potential to provide real-time, image-guidance of radiation therapy to identify when a target moves outside of the treatment volume (e.g. due to breathing), but the associated probe-induced tissue deformation causes local anatomical deviations from the treatment plan. If the US probe is placed to achieve similar tissue deformations in the CT images required for treatment planning, its presence causes streak artifacts that will interfere with treatment planning calculations. To overcome these challenges, we propose robot-assisted placement of a real ultrasound probe, followed by probe removal and replacement with a geometrically-identical, CT-compatible model probe. This work is the first to investigate in vivo deformation reproducibility with the proposed approach. A dog's prostate, liver, and pancreas were each implanted with three 2.38-mm spherical metallic markers, and the US probe was placed to visualize the implanted markers in each organ. The real and model probes were automatically removed and returned to the same position (i.e. position control), and CT images were acquired with each probe placement. The model probe was also removed and returned with the same normal force measured with the real US probe (i.e. force control). Marker positions in CT images were analyzed to determine reproducibility, and a corollary reproducibility study was performed on ex vivo tissue. In vivo results indicate that tissue deformations with the real probe were repeatable under position control for the prostate, liver, and pancreas, with median 3D reproducibility of 0.3 mm, 0.3 mm, and 1.6 mm, respectively, compared to 0.6 mm for the ex vivo tissue. For the prostate, the mean 3D tissue displacement errors between the real and model probes were 0.2 mm under position control and 0.6 mm under force control, which are both within acceptable

  14. SU-E-J-236: Audiovisual Biofeedback Improves Breath-Hold Lung Tumor Position Reproducibility Measured with 4D MRI

    SciTech Connect

    Lee, D; Pollock, S; Keall, P; Greer, P; Lapuz, C; Ludbrook, J; Kim, T

    2015-06-15

    Purpose: Audiovisual biofeedback breath-hold (AVBH) was employed to reproduce tumor position on inhale and exhale breath-holds for 4D tumor information. We hypothesize that lung tumor position will be more consistent using AVBH compared with conventional breath-hold (CBH). Methods: Lung tumor positions were determined for seven lung cancer patients (age: 25 – 74) during to two separate 3T MRI sessions. A breathhold training session was performed prior to the MRI sessions to allow patients to become comfortable with AVBH and their exhale and inhale target positions. CBH and AVBH 4D image datasets were obtained in the first MRI session (pre-treatment) and the second MRI session (midtreatment) within six weeks of the first session. Audio-instruction (MRI: Siemens Skyra) in CBH and verbal-instruction (radiographer) in AVBH were used. A radiation oncologist contoured the lung tumor using Eclipse (Varian Medical Systems); tumor position was quantified as the centroid of the contoured tumor after rigid registration based on vertebral anatomy across two MRI sessions. CBH and AVBH were compared in terms of the reproducibility assessed via (1) the difference between the two exhale positions for the two sessions and the two inhale positions for the sessions. (2) The difference in amplitude (exhale to inhale) between the two sessions. Results: Compared to CBH, AVBH improved the reproducibility of two exhale (or inhale) lung tumor positions relative to each other by 33%, from 6.4±5.3 mm to 4.3±3.0 mm (p=0.005). Compared to CBH, AVBH improved the reproducibility of exhale and inhale amplitude by 66%, from 5.6±5.9 mm to 1.9±1.4 mm (p=0.005). Conclusions: This study demonstrated that audiovisual biofeedback can be utilized for improving the reproducibility of breath-hold lung tumor position. These results are advantageous towards achieving more accurate emerging radiation treatment planning methods, in addition to imaging and treatment modalities utilizing breath

  15. Mechanics of precisely controlled thin film buckling on Elastomeric substrate.

    SciTech Connect

    Sun, Y.; Jiang, H.; Rogers, J.; Huang, Y.; Arizone State Univ.; Beckman Inst.; University of Illinois Urbana-Champaign

    2007-01-01

    Stretchable electronics has many important and emerging applications. Sun et al. [Nature Nanotech. 1, 201 (2006)] recently demonstrated stretchable electronics based on precisely controlled buckle geometries in GaAs and Si nanoribbons on elastomeric substrates. A nonlinear buckling model is presented in this letter to study the mechanics of this type of thin film/substrate system. An analytical solution is obtained for the buckling geometry (wavelength and amplitude) and the maximum strain in buckled thin film. This solution agrees very well with the experiments, and shows explicitly how buckling can significantly reduce the thin film strain to achieve the system stretchability.

  16. 46 CFR 56.80-10 - Forming (reproduces 129.2).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Forming (reproduces 129.2). 56.80-10 Section 56.80-10... APPURTENANCES Bending and Forming § 56.80-10 Forming (reproduces 129.2). (a) Piping components may be formed... method, providing such processes result in formed surfaces which are uniform and free of cracks or...

  17. 46 CFR 56.80-10 - Forming (reproduces 129.2).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Forming (reproduces 129.2). 56.80-10 Section 56.80-10... APPURTENANCES Bending and Forming § 56.80-10 Forming (reproduces 129.2). (a) Piping components may be formed... method, providing such processes result in formed surfaces which are uniform and free of cracks or...

  18. Reproducible, high performance patch antenna array apparatus and method of fabrication

    DOEpatents

    Strassner, II, Bernd H.

    2007-01-23

    A reproducible, high-performance patch antenna array apparatus includes a patch antenna array provided on a unitary dielectric substrate, and a feed network provided on the same unitary substrate and proximity coupled to the patch antenna array. The reproducibility is enhanced by using photolithographic patterning and etching to produce both the patch antenna array and the feed network.

  19. Reproducible Synthetic Method for the Topological Superconductor CuxBi2Se3

    NASA Astrophysics Data System (ADS)

    Kondo, Ryusuke; Yoshinaka, Taiki; Imai, Yoshinori; Maeda, Atsutaka

    2013-06-01

    We report a reproducible synthetic method for superconducting Cu-intercalated Bi2Se3 by an improved melt growth method. Avoiding the production of Cu2Se, which has a higher melting point than that of Bi2Se3, and quenching Cu--Bi--Se mixtures at the liquid phase are keys to obtaining good superconducting samples in a reproducible manner.

  20. Implementing reproducible research using the Madagascar open-source software package

    NASA Astrophysics Data System (ADS)

    Fomel, S.

    2015-12-01

    Reproducible research is a concept pioneered by Jon Claerbout. It refers to the discipline of attaching software code and data to scientific publications, which enables the reader to reproduce, verify, and extend published computational experiments. The Madagascar open-source software package provides an example of implementing the reproducible research discipline in geophysical publications. The package contains not only software tools for making geophysical computations but also research papers complete with links to data and reproducible data-analysis workflows. When researchers discover a research paper published on the Madagascar website and install Madagascar, they are able to follow the links and replicate all computations to verify the published computational results. Of course, reproducibility is not the goal in itself. The goal is to be able to extend previously published research by, for example, trying new computations on previously used data or previously used computations on new data. The Madagscar collection currently contains about 150 research papers and book chapters and about 900 reproducible scripts. More than 80 people from different organizations around the world have contributed to the development. This experience shows that, instead of being the responsibility of an individual author, computational reproducibility can become the responsibility of open-source scientific-software communities. Our experience shows how a dedicated community effort can keep a body of computational research alive by actively maintaining its reproducibility.

  1. Students’ Achievement Goals, Learning-Related Emotions and Academic Achievement

    PubMed Central

    Lüftenegger, Marko; Klug, Julia; Harrer, Katharina; Langer, Marie; Spiel, Christiane; Schober, Barbara

    2016-01-01

    In the present research, the recently proposed 3 × 2 model of achievement goals is tested and associations with achievement emotions and their joint influence on academic achievement are investigated. The study was conducted with 388 students using the 3 × 2 Achievement Goal Questionnaire including the six proposed goal constructs (task-approach, task-avoidance, self-approach, self-avoidance, other-approach, other-avoidance) and the enjoyment and boredom scales from the Achievement Emotion Questionnaire. Exam grades were used as an indicator of academic achievement. Findings from CFAs provided strong support for the proposed structure of the 3 × 2 achievement goal model. Self-based goals, other-based goals and task-approach goals predicted enjoyment. Task-approach goals negatively predicted boredom. Task-approach and other-approach predicted achievement. The indirect effects of achievement goals through emotion variables on achievement were assessed using bias-corrected bootstrapping. No mediation effects were found. Implications for educational practice are discussed. PMID:27199836

  2. Gold nanoparticles supported in zirconia-ceria mesoporous thin films: a highly active reusable heterogeneous nanocatalyst.

    PubMed

    Violi, Ianina L; Zelcer, Andrés; Bruno, Mariano M; Luca, Vittorio; Soler-Illia, Galo J A A

    2015-01-21

    Gold nanoparticles (NP) trapped in the mesopores of mixed zirconia-ceria thin films are prepared in a straightforward and reproducible way. The films exhibit enhanced stability and excellent catalytic activity in nitro-group reduction by borohydride and electrocatalytic activity in CO and ethanol oxidation and oxygen reduction.

  3. Germanium Lift-Off Masks for Thin Metal Film Patterning

    NASA Technical Reports Server (NTRS)

    Brown, Ari

    2012-01-01

    A technique has been developed for patterning thin metallic films that are, in turn, used to fabricate microelectronics circuitry and thin-film sensors. The technique uses germanium thin films as lift-off masks. This requires development of a technique to strip or undercut the germanium chemically without affecting the deposited metal. Unlike in the case of conventional polymeric lift-off masks, the substrate can be exposed to very high temperatures during processing (sputter deposition). The reason why polymeric liftoff masks cannot be exposed to very high temperatures (greater than 100 C) is because (a) they can become cross linked, making lift-off very difficult if not impossible, and (b) they can outgas nitrogen and oxygen, which then can react with the metal being deposited. Consequently, this innovation is expected to find use in the fabrication of transition edge sensors and microwave kinetic inductance detectors, which use thin superconducting films deposited at high temperature as their sensing elements. Transition edge sensors, microwave kinetic inductance detectors, and their circuitry are comprised of superconducting thin films, for example Nb and TiN. Reactive ion etching can be used to pattern these films; however, reactive ion etching also damages the underlying substrate, which is unwanted in many instances. Polymeric lift-off techniques permit thin-film patterning without any substrate damage, but they are difficult to remove and the polymer can outgas during thin-film deposition. The outgassed material can then react with the film with the consequence of altered and non-reproducible materials properties, which, in turn, is deleterious for sensors and their circuitry. The purpose of this innovation was to fabricate a germanium lift-off mask to be used for patterning thin metal films.

  4. Lithospheric and crustal thinning

    NASA Technical Reports Server (NTRS)

    Moretti, I.

    1985-01-01

    In rift zones, both the crust and the lithosphere get thinner. The amplitude and the mechanism of these two thinning situations are different. The lithospheric thinning is a thermal phenomenon produced by an asthenospherical uprising under the rift zone. In some regions its amplitude can exceed 200%. This is observed under the Baikal rift where the crust is directly underlaid by the mantellic asthenosphere. The presence of hot material under rift zones induces a large negative gravity anomaly. A low seismic velocity zone linked to this thermal anomaly is also observed. During the rifting, the magmatic chambers get progressively closer from the ground surface. Simultaneously, the Moho reflector is found at shallow depth under rift zones. This crustal thinning does not exceed 50%. Tectonic stresses and vertical movements result from the two competing effects of the lithospheric and crustal thinning. On the one hand, the deep thermal anomaly induces a large doming and is associated with extensive deviatoric stresses. On the other hand, the crustal thinning involves the formation of a central valley. This subsidence is increased by the sediment loading. The purpose here is to quantify these two phenomena in order to explain the morphological and thermal evolution of rift zones.

  5. Influence of polarity on the scalability and reproducibility of solvent-free microwave-assisted reactions.

    PubMed

    Díaz-Ortiz, Angel; de la Hoz, Antonio; Alcázar, Jesús; Carrillo, José R; Herrero, María A; Fontana, Alberto; Muñoz, Juan de M; Prieto, Pilar; de Cózar, Abel

    2011-02-01

    Organic reactions performed in the absence of solvent in domestic ovens without appropriate temperature control are generally considered as not reproducible, particularly when different instruments are used. For this reason, reproducibility has historically been one of the major issues associated with Microwave-Assisted Organic Synthesis (MAOS) especially when domestic ovens are involved. The lack of reproducibility limits the general applicability and the scale up of these reactions. In this work several solvent-free reactions previously carried out in domestic ovens have been translated into a single-mode microwave reactor and then scaled up in a multimode oven. The results show that most of these reactions, although not considered as reproducible, can be easily updated and applied in microwave reactors using temperature-controlled conditions. Furthermore, computational calculations can assist to explain and/or predict whether a reaction will be reproducible or not.

  6. Mesoscopic simulation of a thinning liquid bridge using the dissipative particle dynamics method

    NASA Astrophysics Data System (ADS)

    Mo, Chao-jie; Yang, Li-jun; Zhao, Fei; Cui, Kun-da

    2015-08-01

    In this research, the dissipative particle dynamics method was used to investigate the problem of thinning and breakup in a liquid bridge. It was found that both the inertial-force-dominated thinning process and the thermal-fluctuation-dominated thinning process can be reproduced with the dissipative particle dynamics (DPD) method by varying the simulation parameters. A highly suspect viscous thinning regime was also found, but the conclusion is not irrefutable because of the complication of the shear viscosity of DPD fluid. We show in this article that the DPD method can serve as a good candidate to elucidate crossover problem in liquid bridge thinning from being hydrodynamics dominated to being thermal fluctuation dominated.

  7. Thin film temperature sensor

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.

    1980-01-01

    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

  8. Biomimetic thin film deposition

    NASA Astrophysics Data System (ADS)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  9. Thin film photovoltaic device

    DOEpatents

    Catalano, Anthony W.; Bhushan, Manjul

    1982-01-01

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

  10. Shear Thinning in Xenon

    NASA Technical Reports Server (NTRS)

    Bergm Robert F.; Moldover, Michael R.; Yao, Minwu; Zimmerli, Gregory A.

    2009-01-01

    We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids such as molten plastics or ketchup, near the critical point of xenon. The data span a wide range of dimensionless shear rate: the product of the shear rate and the relaxation time of critical fluctuations was greater than 0.001 and was less than 700. As predicted by theory, shear thinning occurred when this product was greater than 1. The measurements were conducted aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity.

  11. Thin film ceramic thermocouples

    NASA Technical Reports Server (NTRS)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  12. Thin-film optical initiator

    DOEpatents

    Erickson, Kenneth L.

    2001-01-01

    A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

  13. Development of a protocol to quantify local bone adaptation over space and time: Quantification of reproducibility.

    PubMed

    Lu, Yongtao; Boudiffa, Maya; Dall'Ara, Enrico; Bellantuono, Ilaria; Viceconti, Marco

    2016-07-05

    In vivo micro-computed tomography (µCT) scanning of small rodents is a powerful method for longitudinal monitoring of bone adaptation. However, the life-time bone growth in small rodents makes it a challenge to quantify local bone adaptation. Therefore, the aim of this study was to develop a protocol, which can take into account large bone growth, to quantify local bone adaptations over space and time. The entire right tibiae of eight 14-week-old C57BL/6J female mice were consecutively scanned four times in an in vivo µCT scanner using a nominal isotropic image voxel size of 10.4µm. The repeated scan image datasets were aligned to the corresponding baseline (first) scan image dataset using rigid registration. 80% of tibia length (starting from the endpoint of the proximal growth plate) was selected as the volume of interest and partitioned into 40 regions along the tibial long axis (10 divisions) and in the cross-section (4 sectors). The bone mineral content (BMC) was used to quantify bone adaptation and was calculated in each region. All local BMCs have precision errors (PE%CV) of less than 3.5% (24 out of 40 regions have PE%CV of less than 2%), least significant changes (LSCs) of less than 3.8%, and 38 out of 40 regions have intraclass correlation coefficients (ICCs) of over 0.8. The proposed protocol allows to quantify local bone adaptations over an entire tibia in longitudinal studies, with a high reproducibility, an essential requirement to reduce the number of animals to achieve the necessary statistical power.

  14. The Mechanics of Human Achievement.

    PubMed

    Duckworth, Angela L; Eichstaedt, Johannes C; Ungar, Lyle H

    2015-07-01

    Countless studies have addressed why some individuals achieve more than others. Nevertheless, the psychology of achievement lacks a unifying conceptual framework for synthesizing these empirical insights. We propose organizing achievement-related traits by two possible mechanisms of action: Traits that determine the rate at which an individual learns a skill are talent variables and can be distinguished conceptually from traits that determine the effort an individual puts forth. This approach takes inspiration from Newtonian mechanics: achievement is akin to distance traveled, effort to time, skill to speed, and talent to acceleration. A novel prediction from this model is that individual differences in effort (but not talent) influence achievement (but not skill) more substantially over longer (rather than shorter) time intervals. Conceptualizing skill as the multiplicative product of talent and effort, and achievement as the multiplicative product of skill and effort, advances similar, but less formal, propositions by several important earlier thinkers.

  15. The Mechanics of Human Achievement

    PubMed Central

    Duckworth, Angela L.; Eichstaedt, Johannes C.; Ungar, Lyle H.

    2015-01-01

    Countless studies have addressed why some individuals achieve more than others. Nevertheless, the psychology of achievement lacks a unifying conceptual framework for synthesizing these empirical insights. We propose organizing achievement-related traits by two possible mechanisms of action: Traits that determine the rate at which an individual learns a skill are talent variables and can be distinguished conceptually from traits that determine the effort an individual puts forth. This approach takes inspiration from Newtonian mechanics: achievement is akin to distance traveled, effort to time, skill to speed, and talent to acceleration. A novel prediction from this model is that individual differences in effort (but not talent) influence achievement (but not skill) more substantially over longer (rather than shorter) time intervals. Conceptualizing skill as the multiplicative product of talent and effort, and achievement as the multiplicative product of skill and effort, advances similar, but less formal, propositions by several important earlier thinkers. PMID:26236393

  16. Repeatability and reproducibility of individual abutment impression, assessed with a blue light scanner

    PubMed Central

    Kim, Dong-Yeon; Lee, Jae-Jun; Kim, Ji-Hwan

    2016-01-01

    PURPOSE We assessed the repeatability and reproducibility of abutment teeth dental impressions, digitized with a blue light scanner, by comparing the discrepancies in repeatability and reproducibility values for different types of abutment teeth. MATERIALS AND METHODS To evaluate repeatability, impressions of the canine, first premolar, and first molar, prepared for ceramic crowns, were repeatedly scanned to acquire 5 sets of 3-dimensional data via stereolithography (STL) files. Point clouds were compared and the error sizes were measured (n=10, per type). To evaluate reproducibility, the impressions were rotated by 10-20° on the table and scanned. These data were compared to the first STL data and the error sizes were measured (n=5, per type). One-way analysis of variance was used to assess the repeatability and reproducibility of the 3 types of teeth, and Tukey honest significant differences (HSD) multiple comparison test was used for post hoc comparisons (α=.05). RESULTS The differences with regard to repeatability were 4.5, 2.7, and 3.1 µm for the canine, premolar, and molar, indicating the poorest repeatability for the canine (P<.001). For reproducibility, the differences were 6.6, 5.8, and 11.0 µm indicating the poorest reproducibility for the molar (P=.007). CONCLUSION Our results indicated that impressions of individual abutment teeth, digitized with a blue light scanner, had good repeatability and reproducibility. PMID:27350856

  17. Thin film thermocouples for thermoelectric characterization of nanostructured materials

    NASA Astrophysics Data System (ADS)

    Grayson, Matthew; Zhou, Chuanle; Varrenti, Andrew; Chyung, Seung Hye; Long, Jieyi; Memik, Seda

    2011-03-01

    The increased use of nanostructured materials as thermoelectrics requires reliable and accurate characterization of the anisotropic thermal coefficients of small structures, such as superlattices and quantum wire networks. Thin evaporated metal films can be used to create thermocouples with a very small thermal mass and low thermal conductivity, in order to measure thermal gradients on nanostructures and thereby measure the thermal conductivity and the Seebeck coefficient of the nanostructure. In this work we confirm the known result that thin metal films have lower Seebeck coefficients than bulk metals, and we also calibrate the Seebeck coefficient of a thin-film Ni/Cr thermocouple with 50 nm thickness, showing it to have about 1/4 the bulk value. We demonstrate reproducibility of this thin-filmSeebeck coefficient on multiple substrates, and we show that this coefficient does, in fact, change as a function of film thickness. We will discuss prototype measurement designs and preliminary work as to how these thin films can be used to study both Seebeck coefficients and thermal conductivities of superlattices in various geometries. The same technology can in principle be used on integrated circuits for thermal mapping, under the name ``Integrated On-Chip Thermocouple Array'' (IOTA).

  18. Body composition and feed intake of reproducing and growing mice divergently selected for heat loss.

    PubMed

    Bhatnagar, A S; Nielsen, M K

    2014-05-01

    Changes in maintenance energy requirements and in feed efficiency have been achieved by divergent selection for heat loss in mice in 3 replicates, creating high heat loss, high maintenance (MH) and low heat loss, low maintenance (ML) lines and an unselected control (MC). However, feed intake has mainly been measured in mature animals and not during growth or reproduction. Additionally, there is evidence that reducing maintenance energy will increase fat content, an undesirable result. To evaluate if selection has altered body composition and lifecycle feed intake, mating pairs were continuously mated and maintained for up to 1 yr unless culled. Offspring pairs were sampled from each line at each parity and maintained from 21 to 49 d of age. Feed intake was recorded for mating pairs throughout the year and on offspring pairs. Body weight was recorded on all animals at culling as well as percent fat, total fat, and total lean, measured by dual X-ray densitometry. Average daily gain was also recorded for offspring. Energy partitioning was achieved using 2 approaches: Approach I regressed energy intake of the pair on sum of daily metabolic weight and total gain to obtain maintenance (bm) and growth (bg) coefficients for each line, replicate, feeding period, and sex (offspring pairs only); Approach II calculated bm for each pair assuming constant energy values for lean and fat gain. Energy coefficients and body composition traits were evaluated for effect of selection (MH vs. ML) and asymmetry of selection ([MH + ML]/2 vs. MC). Both MC mating and offspring pairs tended to have greater BW than the average of the selection lines (P < 0.08). Males of offspring pairs weighed more than females (P < 0.01), while females of mating pairs weighed more than males (P < 0.01). Line was insignificant (P > 0.15) for body composition traits. Using Approach I, MH mice had a greater bm than ML mice for mating pairs (P = 0.03) but not offspring pairs (P = 0.50). For Approach II, MH had a

  19. Reproducibility of structural strength and stiffness for graphite-epoxy aircraft spoilers

    NASA Technical Reports Server (NTRS)

    Howell, W. E.; Reese, C. D.

    1978-01-01

    Structural strength reproducibility of graphite epoxy composite spoilers for the Boeing 737 aircraft was evaluated by statically loading fifteen spoilers to failure at conditions simulating aerodynamic loads. Spoiler strength and stiffness data were statistically modeled using a two parameter Weibull distribution function. Shape parameter values calculated for the composite spoiler strength and stiffness were within the range of corresponding shape parameter values calculated for material property data of composite laminates. This agreement showed that reproducibility of full scale component structural properties was within the reproducibility range of data from material property tests.

  20. Method for reproducibly preparing a low-melting high-carbon yield precursor

    DOEpatents

    Smith, Wesley E.; Napier, Jr., Bradley

    1978-01-01

    The present invention is directed to a method for preparing a reproducible synthetic carbon precursor by the autoclave polymerization of indene (C.sub.9 H.sub.8) at a temperature in the range of 470.degree.-485.degree. C, and at a pressure in the range of about 1000 to about 4300 psi. Volatiles in the resulting liquid indene polymer are removed by vacuum outgassing to form a solid carbon precursor characterized by having a relatively low melting temperature, high-carbon yield, and high reproducibility which provide for the fabrication of carbon and graphite composites having strict requirements for reproducible properties.

  1. Epitaxial thin films

    DOEpatents

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan

    2006-04-25

    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  2. Protein thin film machines.

    PubMed

    Federici, Stefania; Oliviero, Giulio; Hamad-Schifferli, Kimberly; Bergese, Paolo

    2010-12-01

    We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fueled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity stimulus the drive can be completely reversed in its direction by introducing a surface coating ligand. Experimental results are throughout discussed within a general yet simple thermodynamic model.

  3. Treading on Thin Water.

    ERIC Educational Resources Information Center

    Haley, Richard D.

    1985-01-01

    Provides a simple introduction to animals whose habitat is the thin surface film of water. Describes adaptive mechanisms of water striders, whirlygigs and riffle bugs and suggests ways to observe them in the wild or as aquarium animals. Includes basic demonstrations of the nature of surface tension. (JHZ)

  4. Thin Wall Iron Castings

    SciTech Connect

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  5. Thin Lens Ray Tracing.

    ERIC Educational Resources Information Center

    Gatland, Ian R.

    2002-01-01

    Proposes a ray tracing approach to thin lens analysis based on a vector form of Snell's law for paraxial rays as an alternative to the usual approach in introductory physics courses. The ray tracing approach accommodates skew rays and thus provides a complete analysis. (Author/KHR)

  6. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  7. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2014-02-01

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm-2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

  8. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers.

    PubMed

    Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2014-02-14

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10,000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm(-2). The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

  9. Reproducibility of expired breath hydrogen levels in the neonate: a comparison of two methods for sample collection.

    PubMed

    Broadbent, R; Robb, T A; Davidson, G P

    1983-02-07

    We have compared a nasopharyngeal catheter method for breath sampling and a valved collection device. Sample quality was assessed by simultaneous oxygen measurement and reproducibility was checked by the analysis of 50 pairs of samples from four premature neonates. Both collection methods produced samples of highly variable quality suggesting a variable mixture of alveolar and non-alveolar air as well as differences in expired oxygen levels between babies. The mean oxygen levels were similar for both sampling techniques. Linear regression analysis of paired hydrogen results showed a highly significant correlation coefficient r = 0.73. This was improved markedly to r = 0.94 by normalization of hydrogen values based on observed oxygen levels, and so supports the earlier article by Robb and Davidson [1]. All breath hydrogen analyses require a measure of sample quality. Reproducible results and meaningful changes in hydrogen concentration in breath samples can only be achieved by correction according to sample quality. Correction to a common oxygen value should allow quantitative comparisons between patients. Samples were best collected from neonates by the nasopharyngeal catheter method, which least disturbed the patient, allowed multiple sample collection and gave lower oxygen and higher hydrogen values where large differences between pairs occurred.

  10. Long-term reproducibility optimization of an x-ray process for bone architectural evaluation during osteoporosis.

    PubMed

    Fidouh, F; Harba, R; Jacquet, G; Loussot, T; Lespessailles, E

    1999-01-01

    Non-invasive and in vivo assessment of bone architectural changes at high resolution is of considerable interest in osteoporosis. In this note, the use of an x-ray acquisition system in the evaluation of the architectural quality of trabecular bone by radiographic texture analysis is optimized to achieve good long-term reproducibility. First, radiographic and digitization processes are modelled and defined. Procedures to make radiographs and their digital images are fixed. Then, measurements of the modulation transfer function (MTF) of the entire acquisition chain were completed. These measurements provide an MTF in excess of 30% at a spatial frequency of 2.5 lp/mm. Also, results of a fractal texture analysis made on digital images of calcaneus radiographs show a mean coefficient of variation of 2.07%. These data show that good long-term reproducibility can make the x-ray acquisition system efficient for patient follow-up, or evaluation of treatment regimes for osteoporosis. Finally, it is shown that fractal texture parameters are statistically different in an osteoporotic population and in a control group. Therefore, this system should also be of medical interest.

  11. Hot-Volumes as Uniform and Reproducible SERS-Detection Enhancers in Weakly-Coupled Metallic Nanohelices

    PubMed Central

    Caridad, José M.; Winters, Sinéad; McCloskey, David; Duesberg, Georg S.; Donegan, John F.; Krstić, Vojislav

    2017-01-01

    Reproducible and enhanced optical detection of molecules in low concentrations demands simultaneously intense and homogeneous electric fields acting as robust signal amplifiers. To generate such sophisticated optical near-fields, different plasmonic nanostructures were investigated in recent years. These, however, exhibit either high enhancement factor (EF) or spatial homogeneity but not both. Small interparticle gaps or sharp nanostructures show enormous EFs but no near-field homogeneity. Meanwhile, approaches using rounded and separated monomers create uniform near-fields with moderate EFs. Here, guided by numerical simulations, we show how arrays of weakly-coupled Ag nanohelices achieve both homogeneous and strong near-field enhancements, reaching even the limit forreproducible detection of individual molecules. The unique near-field distribution of a single nanohelix consists of broad hot-spots, merging with those from neighbouring nanohelices in specific array configurations and generating a wide and uniform detection zone (“hot-volume”). We experimentally assessed these nanostructures via surface-enhanced Raman spectroscopy, obtaining a corresponding EF of ~107 and a relative standard deviation <10%. These values demonstrate arrays of nanohelices as state-of-the-art substrates for reproducible optical detection as well as compelling nanostructures for related fields such as near-field imaging. PMID:28358022

  12. Hot-Volumes as Uniform and Reproducible SERS-Detection Enhancers in Weakly-Coupled Metallic Nanohelices.

    PubMed

    Caridad, José M; Winters, Sinéad; McCloskey, David; Duesberg, Georg S; Donegan, John F; Krstić, Vojislav

    2017-03-30

    Reproducible and enhanced optical detection of molecules in low concentrations demands simultaneously intense and homogeneous electric fields acting as robust signal amplifiers. To generate such sophisticated optical near-fields, different plasmonic nanostructures were investigated in recent years. These, however, exhibit either high enhancement factor (EF) or spatial homogeneity but not both. Small interparticle gaps or sharp nanostructures show enormous EFs but no near-field homogeneity. Meanwhile, approaches using rounded and separated monomers create uniform near-fields with moderate EFs. Here, guided by numerical simulations, we show how arrays of weakly-coupled Ag nanohelices achieve both homogeneous and strong near-field enhancements, reaching even the limit forreproducible detection of individual molecules. The unique near-field distribution of a single nanohelix consists of broad hot-spots, merging with those from neighbouring nanohelices in specific array configurations and generating a wide and uniform detection zone ("hot-volume"). We experimentally assessed these nanostructures via surface-enhanced Raman spectroscopy, obtaining a corresponding EF of ~10(7) and a relative standard deviation <10%. These values demonstrate arrays of nanohelices as state-of-the-art substrates for reproducible optical detection as well as compelling nanostructures for related fields such as near-field imaging.

  13. Improvement of Charge Collection and Performance Reproducibility in Inverted Organic Solar Cells by Suppression of ZnO Subgap States.

    PubMed

    Wu, Bo; Wu, Zhenghui; Yang, Qingyi; Zhu, Furong; Ng, Tsz-Wai; Lee, Chun-Sing; Cheung, Sin-Hang; So, Shu-Kong

    2016-06-15

    Organic solar cells (OSCs) with inverted structure usually exhibit higher power conversion efficiency (PCE) and are more stable than corresponding devices with regular configuration. Indium tin oxide (ITO) surface is often modified with solution-processed low work function metal oxides, such as ZnO, serving as the transparent cathode. However, the defect-induced subgap states in the ZnO interlayer hamper the efficient charge collection and the performance reproducibility of the OSCs. In this work, we demonstrate that suppression of the ZnO subgap states by modification of its surface with an ultrathin Al layer significantly improves the charge extraction and performance reproducibility, achieving PCE of 8.0%, which is ∼15% higher than that of a structurally identical control cell made with a pristine ZnO interlayer. Light intensity-dependent current density-voltage characteristic, photothermal deflection spectroscopy, and X-ray photoelectron spectroscopy measurements point out the enhancement of charge collection efficiency at the organic/cathode interface, due to the suppression of the subgap states in the ZnO interlayer.

  14. Highly reproducible near-field optical imaging with sub-20-nm resolution based on template-stripped gold pyramids.

    PubMed

    Johnson, Timothy W; Lapin, Zachary J; Beams, Ryan; Lindquist, Nathan C; Rodrigo, Sergio G; Novotny, Lukas; Oh, Sang-Hyun

    2012-10-23

    With a template-stripping fabrication technique, we demonstrate the mass fabrication of high-quality, uniform, ultrasharp (10 nm) metallic probes suitable for single-molecule fluorescence imaging, tip-enhanced Raman spectroscopy (TERS), and other near-field imaging techniques. We achieve reproducible single-molecule imaging with sub-20-nm spatial resolution and an enhancement in the detected fluorescence signal of up to 200. Similar results are obtained for TERS imaging of carbon nanotubes. We show that the large apex angle (70.5°) of our pyramidal tip is well suited to scatter the near-field optical signal into the far-field, leading to larger emission enhancement and hence to a larger quantum yield. Each gold or silver pyramidal probe is used on-demand, one at a time, and the unused tips can be stored for extended times without degradation or contamination. The high yield (>95%), reproducibility, durability, and massively parallel fabrication (1.5 million identical probes over a wafer) of the probes hold promise for reliable optical sensing and detection and for cementing near-field optical imaging and spectroscopy as a routine characterization technique.

  15. KIND Reproducibles.

    ERIC Educational Resources Information Center

    KIND Teacher, 1990

    1990-01-01

    Presented are 14 student worksheets for use in teaching about environmental conservation. Topics of these games, puzzles include pollution, rainforests, endangered species, habitat destruction, and solid waste. An answer sheet for teachers is included. (CW)

  16. KIND Reproducibles.

    ERIC Educational Resources Information Center

    KIND Teacher, 1989

    1989-01-01

    Presented are 14 student worksheets for use in teaching the care and humane treatment of animals. Topics of these games, puzzles include both domestic pets and wild animals. An answer sheet for teachers is included. (CW)

  17. KIND Reproducibles.

    ERIC Educational Resources Information Center

    KIND Teacher, 1990

    1990-01-01

    Presented are 14 student worksheets for use in teaching the care of and humane treatment of animals. Topics of these games and puzzles include state animal trivia, domestic pets and wild animals. An answer sheet for teachers is included. (CW)

  18. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

    A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

  19. Thin films for material engineering

    NASA Astrophysics Data System (ADS)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  20. Sequentially evaporated thin Y-Ba-Co-O superconducting films on microwave substrates

    NASA Technical Reports Server (NTRS)

    Valco, G. J.; Rohrer, N. J.; Warner, J. D.; Bhasin, K. B.

    1989-01-01

    The development of high T sub c superconducting thin films on various microwave substrates is of major interest in space electronic systems. Thin films of YBa2Cu3O(7-Delta) were formed on SrTiO3, MgO, ZrO2 coated Al2O3, and LaAlO3 substrates by multi-layer sequential evaporation and subsequent annealing in oxygen. The technique allows controlled deposition of Cu, BaF2 and Y layers, as well as the ZrO buffer layers, to achieve reproducibility for microwave circuit fabrication. The three layer structure of Cu/BaF2/Y is repeated a minimum of four times. The films were annealed in an ambient of oxygen bubbled through water at temperatures between 850 C and 900 C followed by slow cooling (-2 C/minute) to 450 C, a low temperature anneal, and slow cooling to room temperature. Annealing times ranged from 15 minutes to 5 hrs. at high temperature and 0 to 6 hr. at 450 C. Silver contacts for four probe electrical measurements were formed by evaporation followed with an anneal at 500 C. The films were characterized by resistance-temperature measurements, energy dispersive X-ray spectroscopy, X-ray diffraction, and scanning electron microscopy. Critical transition temperatures ranged from 30 K to 87 K as a function of the substrate, composition of the film, thicknesses of the layers, and annealing conditions. Microwave ring resonator circuits were also patterned on these MgO and LaAlO3 substrates.

  1. NMR characterization of thin films

    DOEpatents

    Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2010-06-15

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  2. VACUUM DEPOSITION OF THIN FILMS,

    DTIC Science & Technology

    The book deals with methods of obtaining and processing thin films , methods of measuring the deposition rate and thickness of thin-film layers, and...the main fields of application of thin films . Vacuum requirements and the requirements for the composition of the residual medium in thermal...evaporation and cathode sputtering are given, and modern methods of producing and measuring vacuums and the equipment used in obtaining thin films are described. (Author)

  3. EDUCATIONAL ACHIEVEMENT AND THE NAVAJO.

    ERIC Educational Resources Information Center

    HAAS, JOHN; MELVILLE, ROBERT

    A STUDY WAS DEVISED TO APPRAISE THE ACADEMIC ACHIEVEMENT OF NAVAJO STUDENTS LIVING IN DORMITORIES AWAY FROM THE INDIAN RESERVATION. THE FOLLOWING SEVEN FACTORS WERE CHOSEN TO BE INVESTIGATED AS BEING DIRECTLY RELATED TO ACHIEVEMENT--(1) INTELLIGENCE, (2) READING ABILITY, (3) ANXIETY, (4) SELF-CONCEPT, (5) MOTIVATION, (6) VERBAL DEVELOPMENT, (7)…

  4. Sociocultural Origins of Achievement Motivation

    ERIC Educational Resources Information Center

    Maehr, Martin L.

    1977-01-01

    Presents a theoretical review of work on sociocultural influences on achievement, focusing on a critical evaluation of the work of David McClellan. Offers an alternative conception of achievement motivation which stresses the role of contextual and situational factors in addition to personality factors. Available from: Transaction Periodicals…

  5. Raising Boys' Achievement in Schools.

    ERIC Educational Resources Information Center

    Bleach, Kevan, Ed.

    This book offers insights into the range of strategies and good practice being used to raise the achievement of boys. Case studies by school-based practitioners suggest ideas and measures to address the issue of achievement by boys. The contributions are: (1) "Why the Likely Lads Lag Behind" (Kevan Bleach); (2) "Helping Boys Do…

  6. Teaching the Low Level Achiever.

    ERIC Educational Resources Information Center

    Salomone, Ronald E., Ed.

    1986-01-01

    Intended for teachers of the English language arts, the articles in this issue offer suggestions and techniques for teaching the low level achiever. Titles and authors of the articles are as follows: (1) "A Point to Ponder" (Rachel Martin); (2) "Tracking: A Self-Fulfilling Prophecy of Failure for the Low Level Achiever" (James Christopher Davis);…

  7. Early Intervention and Student Achievement

    ERIC Educational Resources Information Center

    Hormes, Mridula T.

    2009-01-01

    The United States Department of Education has been rigorous in holding all states accountable with regard to student achievement. The No Child Left Behind Act of 2001 clearly laid out federal mandates for all schools to follow. K-12 leaders of public schools are very aware of the fact that results in terms of student achievement need to improve…

  8. Parental Involvement and Academic Achievement

    ERIC Educational Resources Information Center

    Goodwin, Sarah Christine

    2015-01-01

    This research study examined the correlation between student achievement and parent's perceptions of their involvement in their child's schooling. Parent participants completed the Parent Involvement Project Parent Questionnaire. Results slightly indicated parents of students with higher level of achievement perceived less demand or invitations…

  9. Asperger Syndrome and Academic Achievement.

    ERIC Educational Resources Information Center

    Griswold, Deborah E.; Barnhill, Gena P.; Myles, Brenda Smith; Hagiwara, Taku; Simpson, Richard L.

    2002-01-01

    A study focused on identifying the academic characteristics of 21 children and youth who have Asperger syndrome. Students had an extraordinary range of academic achievement scores, extending from significantly above average to far below grade level. Lowest achievement scores were shown for numerical operations, listening comprehension, and written…

  10. Perils of Standardized Achievement Testing

    ERIC Educational Resources Information Center

    Haladyna, Thomas M.

    2006-01-01

    This article argues that the validity of standardized achievement test-score interpretation and use is problematic; consequently, confidence and trust in such test scores may often be unwarranted. The problem is particularly severe in high-stakes situations. This essay provides a context for understanding standardized achievement testing, then…

  11. Stress Correlates and Academic Achievement.

    ERIC Educational Resources Information Center

    Bentley, Donna Anderson; And Others

    An ongoing concern for educators is the identification of factors that contribute to or are associated with academic achievement; one such group of variables that has received little attention are those involving stress. The relationship between perceived sources of stress and academic achievement was examined to determine if reactions to stress…

  12. School Size and Student Achievement

    ERIC Educational Resources Information Center

    Riggen, Vicki

    2013-01-01

    This study examined whether a relationship between high school size and student achievement exists in Illinois public high schools in reading and math, as measured by the Prairie State Achievement Exam (PSAE), which is administered to all Illinois 11th-grade students. This study also examined whether the factors of socioeconomic status, English…

  13. New crop/weed/soil discrimination uses only one wavelength to reproduce the near-infrared signature

    NASA Astrophysics Data System (ADS)

    Hahn, Federico

    1996-11-01

    Plant species discrimination by optical reflectance requires us to analyze reflectance spectral differences between two sampled broad band signatures making use of the discriminative integration index, DII. Crop/weed discrimination analyses of these indexes using a crop threshold introduces the discrimination efficiency of the entire vegetation population consisting of crop and weeds. Best discriminative efficiencies are spectral dependant and results for leek, cabbage, turnip and potato crops having competence with ten different weed species are presented. With the reflectance of an unique wavelength found iteratively, it was possible to reproduce the NIR spectrum of the crop or weed. This reflectance was multiplied by the crop reference spectrum, producing a pattern similar to the real crop signature and for the four crops tested the control wavelength corresponded to the one having the peak reflectance at the red region. This algorithm is the heart of a new model used to distinguish crops from weeds and the results achieved per group are presented.

  14. Automatic control of a robot camera for broadcasting based on cameramen's techniques and subjective evaluation and analysis of reproduced images.

    PubMed

    Kato, D; Katsuura, T; Koyama, H

    2000-03-01

    With the goal of achieving an intelligent robot camera system that can take dynamic images automatically through humanlike, natural camera work, we analyzed how images were shot, subjectively evaluated reproduced images, and examined effects of camerawork, using camera control technique as a parameter. It was found that (1) A high evaluation is obtained when human-based data are used for the position adjusting velocity curve of the target; (2) Evaluation scores are relatively high for images taken with feedback-feedforward camera control method for target movement in one direction; (3) Keeping the target within the image area using the control method that imitates human camera handling becomes increasingly difficult when the target changes both direction and velocity and becomes bigger and faster, and (4) The mechanical feedback method can cope with rapid changes in the target's direction and velocity, constantly keeping the target within the image area, though the viewer finds the image rather mechanical as opposed to humanlike.

  15. Propolis Standardized Extract (EPP-AF®), an Innovative Chemically and Biologically Reproducible Pharmaceutical Compound for Treating Wounds

    PubMed Central

    Berretta, Andresa Aparecida; Nascimento, Andresa Piacezzi; Bueno, Paula Carolina Pires; de Oliveira Lima Leite Vaz, Mirela Mara; Marchetti, Juliana Maldonado

    2012-01-01

    The aim of this study was to develop a formulation, containing the propolis standardized extract (EPP-AF®), which can assist in the healing of skin lesions. To achieve this objective the antimicrobial activity and chemical composition of the propolis extract was determined. The final product was subjected to in vitro and in vivo pre-clinical evaluation. The broth macrodilution method was used to determine the antimicrobial activity of the extracts and formulations against the microorganisms most commonly found in burns, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis. Wistar rats with puncture wounded skin were used to evaluate the wound healing properties of propolis. The results of chemical and biological characterization demonstrated the batch-to-batch reproducibility of the standardized extract which is an unprecedented result. The antimicrobial and wound healing activity of the pharmaceutical studied showed the best results when samples contain 3.6% propolis, suggesting that this is the most promising composition. PMID:22457606

  16. The Lhc Cryomagnet Supports in Glass-Fiber Reinforced Epoxy: a Large Scale Industrial Production with High Reproducibility in Performance

    NASA Astrophysics Data System (ADS)

    Poncet, A.; Struik, M.; Trigo, J.; Parma, V.

    2008-03-01

    The about 1700 LHC main ring super-conducting magnets are supported within their cryostats on 4700 low heat in leak column-type supports. The supports were designed to ensure a precise and stable positioning of the heavy dipole and quadrupole magnets while keeping thermal conduction heat loads within budget. A trade-off between mechanical and thermal properties, as well as cost considerations, led to the choice of glass fibre reinforced epoxy (GFRE). Resin Transfer Moulding (RTM), featuring a high level of automation and control, was the manufacturing process retained to ensure the reproducibility of the performance of the supports throughout the large production. The Spanish aerospace company EADS-CASA Espacio developed the specific RTM process, and produced the total quantity of supports between 2001 and 2004. This paper describes the development and the production of the supports, and presents the production experience and the achieved performance.

  17. Most computational hydrology is not reproducible, so is it really science?

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher; Wagener, Thorsten; Freer, Jim; Han, Dawei; Duffy, Chris; Arheimer, Berit

    2016-10-01

    Reproducibility is a foundational principle in scientific research. Yet in computational hydrology the code and data that actually produces published results are not regularly made available, inhibiting the ability of the community to reproduce and verify previous findings. In order to overcome this problem we recommend that reuseable code and formal workflows, which unambiguously reproduce published scientific results, are made available for the community alongside data, so that we can verify previous findings, and build directly from previous work. In cases where reproducing large-scale hydrologic studies is computationally very expensive and time-consuming, new processes are required to ensure scientific rigor. Such changes will strongly improve the transparency of hydrological research, and thus provide a more credible foundation for scientific advancement and policy support.

  18. A Modified Rule of Thumb for Evaluating Scale Reproducibilities Determined by Electronic Computers

    ERIC Educational Resources Information Center

    Hofmann, Richard J.

    1978-01-01

    The Goodenough technique for determining scale error is compared to the Guttman technique and demonstrated to be more conservative than the Guttman technique. Implications with regard to Guttman's evaluative rule of thumb for evaluating a reproducibility are noted. (Author)

  19. Temperature independent spherical potential which reproduces exactly the second virial coefficient of nonpolar molecules

    SciTech Connect

    Shaw, M.S.; Johnson, J.D.

    1984-10-01

    An expression is derived for a temperature independent spherical potential which reproduces exactly the second virial coefficient for nonpolar molecules given the full anisotropic potential. Comparison is made with the median average over angles and the arithmetic average.

  20. International Interlaboratory Digital PCR Study Demonstrating High Reproducibility for the Measurement of a Rare Sequence Variant.

    PubMed

    Whale, Alexandra S; Devonshire, Alison S; Karlin-Neumann, George; Regan, Jack; Javier, Leanne; Cowen, Simon; Fernandez-Gonzalez, Ana; Jones, Gerwyn M; Redshaw, Nicholas; Beck, Julia; Berger, Andreas W; Combaret, Valérie; Dahl Kjersgaard, Nina; Davis, Lisa; Fina, Frederic; Forshew, Tim; Fredslund Andersen, Rikke; Galbiati, Silvia; González Hernández, Álvaro; Haynes, Charles A; Janku, Filip; Lacave, Roger; Lee, Justin; Mistry, Vilas; Pender, Alexandra; Pradines, Anne; Proudhon, Charlotte; Saal, Lao H; Stieglitz, Elliot; Ulrich, Bryan; Foy, Carole A; Parkes, Helen; Tzonev, Svilen; Huggett, Jim F

    2017-02-07

    This study tested the claim that digital PCR (dPCR) can offer highly reproducible quantitative measurements in disparate laboratories. Twenty-one laboratories measured four blinded samples containing different quantities of a KRAS fragment encoding G12D, an important genetic marker for guiding therapy of certain cancers. This marker is challenging to quantify reproducibly using quantitative PCR (qPCR) or next generation sequencing (NGS) due to the presence of competing wild type sequences and the need for calibration. Using dPCR, 18 laboratories were able to quantify the G12D marker within 12% of each other in all samples. Three laboratories appeared to measure consistently outlying results; however, proper application of a follow-up analysis recommendation rectified their data. Our findings show that dPCR has demonstrable reproducibility across a large number of laboratories without calibration. This could enable the reproducible application of molecular stratification to guide therapy and, potentially, for molecular diagnostics.

  1. Reproducing pairs and the continuous nonstationary Gabor transform on LCA groups

    NASA Astrophysics Data System (ADS)

    Speckbacher, Michael; Balazs, Peter

    2015-10-01

    In this paper we introduce and investigate the concept of reproducing pairs as a generalization of continuous frames. Reproducing pairs yield a bounded analysis and synthesis process while the frame condition can be omitted at both stages. Moreover, we will investigate certain continuous frames (resp. reproducing pairs) on LCA groups, which can be described as a continuous version of nonstationary Gabor systems and state sufficient conditions for these systems to form a continuous frame (resp. reproducing pair). As a byproduct we identify the structure of the frame operator (resp. resolution operator). We will apply our results to systems generated by a unitary action of a subset of the affine Weyl-Heisenberg group in {L}2({{R}}). This setup will also serve as a nontrivial example of a system for which, whereas continuous frames exist, no dual system with the same structure exists even if we drop the frame property.

  2. Multilayered film microreactors fabricated by a one-step thermal bonding technique with high reproducibility and their applications.

    PubMed

    Min, Kyoung-Ik; Kim, Jin-Oh; Kim, Heejin; Im, Do Jin; Kim, Dong-Pyo

    2016-03-21

    We report the versatile uses of multilayered polyimide (PI) film microreactors with various functions including pressure tolerance, three-dimensional mixing and multistep membrane emulsification. Such PI film microreactors were fabricated by a simple one-step thermal bonding technique with high reproducibility. Upon bonding at 300 °C for 1 hour, the thin and flexible film microdevices could withstand pressure up to 8.6 MPa and 16.3 MPa with PI adhesive film or fluoropolymer adhesive, respectively, due to differences in wettability. The hydrophilic and hydrophobic microchannel devices were used to generate monodisperse oil-in-water (O/W) and water-in-oil (W/O) droplets, and polymer micro/nanoparticles at a high generation frequency. A monolithic and chemical resistant film microreactor with a three-dimensional serpentine microchannel was used for the selective reduction of ester to aldehyde by efficient mixing and quenching in a flash chemistry manner, within a several 10(1) millisecond time scale. Furthermore, a novel multilayered film microreactor for organic-aqueous biphasic interfacial reactions was devised by embedding a membrane layer to induce chaotic mixing in both the interface and emulsified phase by flowing through multiple numbers of meshed structures along the hydrophobic channel. This simple and economic fabrication technique significantly facilitates mass production of multilayered film devices that could be useful as a platform for various microfluidic applications in chemistry and biology.

  3. Electron quantization in arbitrarily shaped gold islands on MgO thin films

    NASA Astrophysics Data System (ADS)

    Stiehler, Christian; Pan, Yi; Schneider, Wolf-Dieter; Koskinen, Pekka; Häkkinen, Hannu; Nilius, Niklas; Freund, Hans-Joachim

    2013-09-01

    Low-temperature scanning tunneling microscopy has been employed to analyze the formation of quantum well states (QWS) in two-dimensional gold islands, containing between 50 and 200 atoms, on MgO thin films. The energy position and symmetry of the eigenstates are revealed from conductance spectroscopy and imaging. The majority of the QWS originates from overlapping Au 6p orbitals in the individual atoms and is unoccupied. Their characteristic is already reproduced with simple particle-in-a-box models that account for the symmetry of the islands (rectangular, triangular, or linear). However, better agreement is achieved when considering the true atomic structure of the aggregates via a density functional tight-binding approach. Based on a statistically relevant number of single-island data, we have established a correlation between the island geometry and the gap between the highest-occupied and the lowest-unoccupied molecular orbital in the finite-sized islands. The linear eccentricity is identified as a suitable descriptor for this relationship, as it combines information on both island size and island shape. Finally, the depth of the confinement potential is determined from the spatial extension of QWS beyond the physical boundaries of the Au islands. Our paper demonstrates how electron quantization effects can be analyzed in detail in metal nanostructures. The results may help elucidating the interplay between electronic and chemical properties of oxide-supported clusters as used in heterogeneous catalysis.

  4. Validated high-performance thin-layer chromatography method for steviol glycosides in Stevia rebaudiana.

    PubMed

    Jaitak, Vikas; Gupta, A P; Kaul, V K; Ahuja, P S

    2008-08-05

    A high-performance thin-layer chromatographic (HPTLC) method was developed and validated as per ICH (International Conferences on Harmonization) guidelines for simultaneous quantification of three steviol glycosides, i.e. steviolbioside, stevioside and rebaudioside-A in Stevia rebaudiana leaves. For achieving good separation, mobile phase of ethyl acetate-ethanol-water (80:20:12, v/v/v) on pre-coated silica gel 60 F254 HPTLC plates were used. The densitometric quantification of steviol glycosides was carried out at lambda=510 nm in reflection-absorption mode after spraying with acetic anhydride:sulphuric acid:ethanol reagent. The calibration curves were linear in the range of 160-960 ng/spot for steviolbioside, 1-6 microg/spot for stevioside and 0.5-3 microg/spot for rebaudioside-A with good correlation coefficients (0.998-0.999). The method was found to be reproducible for quantitative analysis of steviol glycosides in S. rebaudiana leaves collected from ten different locations and will serve as a quality control indicator to monitor the commercial production of stevioside and its allied molecules during different stages of its processing.

  5. Controlled synthesis of transition metal dichalcogenide thin films for electronic applications

    NASA Astrophysics Data System (ADS)

    Gatensby, Riley; McEvoy, Niall; Lee, Kangho; Hallam, Toby; Berner, Nina C.; Rezvani, Ehsan; Winters, Sinéad; O'Brien, Maria; Duesberg, Georg S.

    2014-04-01

    Two dimensional transition metal dichalcogenides (TMDs) are exciting materials for future applications in nanoelectronics, nanophotonics and sensing. In particular, sulfides and selenides of molybdenum (Mo) and tungsten (W) have attracted interest as they possess a band gap, which is important for integration into electronic device structures. However, the low throughput synthesis of high quality TMD thin films has thus far hindered the development of devices, and so a scalable method is required to fully exploit their exceptional properties. Within this work a facile route to the manufacture of devices from MoS2 and WS2, grown by vapour phase sulfurisation of pre-deposited metal layers, is presented. Highly homogenous TMD films are produced over large areas. Fine control over TMD film thickness, down to a few layers, is achieved by modifying the thickness of the pre-deposited metal layer. The films are characterised by Raman spectroscopy, electron microscopy and X-ray photoelectron spectroscopy. The thinnest films exhibit photoluminescence, as predicted for monolayer MoS2 films, due to confinement in two dimensions. By using shadow mask lithography, films with well-defined geometries were produced and subsequently integrated with standard microprocessing process flows and electrically characterised. In this way, MoS2 based sensors were produced, displaying sensitivity to NH3 down to 400 ppb. Our device manufacture is versatile, and is adaptable for future nanoscale (opto-) electronic devices as it is reproducible, cost effective and scalable up to wafer scale.

  6. Strong Influence of Humidity on Low-Temperature Thin-Film Fabrication via Metal Aqua Complex for High Performance Oxide Semiconductor Thin-Film Transistors.

    PubMed

    Lim, Keon-Hee; Huh, Jae-Eun; Lee, Jinwon; Cho, Nam-Kwang; Park, Jun-Woo; Nam, Bu-Il; Lee, Eungkyu; Kim, Youn Sang

    2017-01-11

    Oxide semiconductors thin film transistors (OS TFTs) with good transparency and electrical performance have great potential for future display technology. In particular, solution-processed OS TFTs have been attracted much attention due to many advantages such as continuous, large scale, and low cost processability. Recently, OS TFTs fabricated with a metal aqua complex have been focused because they have low temperature processability for deposition on flexible substrate as well as high field-effect mobility for application of advanced display. However, despite some remarkable results, important factors to optimize their electrical performance with reproducibility and uniformity have not yet been achieved. Here, we newly introduce the strong effects of humidity to enhance the electrical performance of OS TFTs fabricated with the metal aqua complex. Through humidity control during the spin-coating process and annealing process, we successfully demonstrate solution-processed InOx/SiO2 TFTs with a good electrical uniformity of ∼5% standard deviation, showing high average field-effect mobility of 2.76 cm(2)V(-1)s(-1) and 15.28 cm(2)V(-1)s(-1) fabricated at 200 and 250 °C, respectively. Also, on the basis of the systematic analyses, we demonstrate the mechanism for the change in electrical properties of InOx TFTs depending on the humidity control. Finally, on the basis of the mechanism, we extended the humidity control to the fabrication of the AlOx insulator. Subsequently, we successfully achieved humidity-controlled InOx/AlOx TFTs fabricated at 200 °C showing high average field-effect mobility of 9.5 cm(2)V(-1)s(-1).

  7. Thin film strain gage development program

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.

    1983-01-01

    Sputtered thin-film dynamic strain gages of 2 millimeter (0.08 in) gage length and 10 micrometer (0.0004 in) thickness were fabricated on turbojet engine blades and tested in a simulated compressor environment. Four designs were developed, two for service to 600 K (600 F) and two for service to 900 K (1200 F). The program included a detailed study of guidelines for formulating strain-gage alloys to achieve superior dynamic and static gage performance. The tests included gage factor, fatigue, temperature cycling, spin to 100,000 G, and erosion. Since the installations are 30 times thinner than conventional wire strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain measurement accuracy higher than that attained with conventional gages is expected. The low profile and good adherence of the thin film elements is expected to result in improved durability over conventional gage elements in engine tests.

  8. Achieving immortality in the C. elegans germline.

    PubMed

    Smelick, Chris; Ahmed, Shawn

    2005-01-01

    Germline immortality is a topic that has intrigued theoretical biologists interested in aging for over a century. The germ cell lineage can be passed from one generation to the next, indefinitely. In contrast, somatic cells are typically only needed for a single generation and are then discarded. Germ cells may, therefore, harbor rejuvenation mechanisms that enable them to proliferate for eons. Such processes are thought to be either absent from or down-regulated in somatic cells, although cell non-autonomous forms of rejuvenation are formally possible. A thorough description of mechanisms that foster eternal youth in germ cells is lacking. The mysteries of germline immortality are being addressed in the nematode Caenorhabditis elegans by studying mutants that reproduce normally for several generations but eventually become sterile. The mortal germline mutants probably become sterile as a consequence of accumulating various forms of heritable cellular damage. Such mutants are abundant, indicating that several different biochemical pathways are required to rejuvenate the germline. Thus, forward genetics should help to define mechanisms that enable the germline to achieve immortality.

  9. Tackling reproducibility in microcantilever biosensors: a statistical approach for sensitive and specific end-point detection of immunoreactions.

    PubMed

    Kosaka, Priscila M; Tamayo, Javier; Ruz, José J; Puertas, Sara; Polo, Ester; Grazu, Valeria; de la Fuente, Jesús M; Calleja, Montserrat

    2013-02-21

    In the last decade, microcantilever biosensors have shown enormous potential for highly sensitive label-free detection of nucleic acid and proteins. Despite the enormous advances, the promise of applications of this technology in the biomedical field has been frustrated because of its low reproducibility. Here we tackle the reproducibility issue in microcantilever biosensors and provide the guidelines to minimize the deviations in the biosensor response between different assays. We use as a model system the label-free end-point detection of horseradish peroxidase. We choose the end-point detection mode because of its suitability for implementation in the clinical field that requires simplicity and point-of-care capability. Our study comprises the analysis of 1012 cantilevers with different antibody surface densities, two blocking strategies based on polyethylene-glycol (PEG) and bovine serum albumin (BSA) and stringent controls. The study reveals that the performance of the assay critically depends on both antibody surface density and blocking strategies. We find that the optimal conditions involve antibody surface densities near but below saturation and blocking with PEG. We find that the surface stress induced by the antibody-antigen binding is significantly correlated with the surface stress generated during the antibody attachment and blocking steps. The statistical correlation is harnessed to identify immobilization failure or success, and thus enhancing the specificity and sensitivity of the assay. This procedure enables achieving rates of true positives and true negatives of 90% and 91% respectively. The detection limit is of 10 ng mL(-1) (250 pM) that is similar to the detection limit obtained in our enzyme-linked immunosorbent assay (ELISA) and at least two orders of magnitude smaller than that achieved with well-established label-free biosensors such as a quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) sensor.

  10. Formation of Thin-Films of CdTe, CdSe, and CdS by Electrochemical ALE

    DTIC Science & Technology

    1997-10-16

    deposition system. Previous reports of an automated system for forming ECALE deposits involved use of a small thin layer flow cell, which evidenced...several drawbacks. Conversion of the thin layer cell to a thick layer design resulted in greatly improved deposit quality and reproducibility. Deposits were...contained some excess chalcogenide, probably the result of less than ideal deposition parameters. Increasing amounts of particulates and surface roughening

  11. Synthesis and Screening of Thin Films in the CeCl3-CeBr3 System for Scintillator Applications

    SciTech Connect

    Matson, Dean W.; Graff, Gordon L.; Male, Jonathan L.; Johnson, Bradley R.; Nie, Zimin; Joly, Alan G.; Olsen, Larry C.

    2010-04-02

    Thin film samples of CeCl3, CeBr3, and combinatorial compositions along the CeCl3-CeBr3 join were produced using thermal evaporation, which is being evaluated as a method for rapid screening of new scintillator materials. The combinatorial thin films were shown to be compositionally reproducible from run-to-run within reasonable limitations. Analytical results suggest a continuous variation in the combinatorial samples in terms of their compositions, crystal structures, and luminescence characteristics.

  12. Improved reproducibility of high-resolution peripheral quantitative computed tomography for measurement of bone quality.

    PubMed

    MacNeil, Joshua A; Boyd, Steven K

    2008-07-01

    A human high-resolution peripheral quantitative computed tomography scanner (HR-pQCT) (XtremeCT, Scanco Medical, Switzerland) capable of measuring three important indicators of bone quality (micro-architectural morphology, mineralization and mechanical stiffness) has been developed. The goal of this study was to evaluate the reproducibility of male and female HR-pQCT in vivo measurements, and elucidate the causes of error in these measurements through a comparison with in vitro measurements. The best possible short-term reproducibility was found using a set of 10 in vitro measurements without repositioning, and a set of 10 with repositioning. Subsequently, in vivo measurements were performed on 15 male and 15 female subjects at baseline and follow-ups of 1 week and 4 months to determine the short- and long-term reproducibility of the system. In addition to the 2D area matching method used in the standard evaluation protocol, a custom developed 3D registration method was used to find the common region between repeated scans. The best possible reproducibility without movement artifacts and repositioning error was less than 0.5%, while the reproducibility with repositioning error was less than 1.5%. The in vivo reproducibility of density (<1%), morphological (<4.5%) and stiffness (<3.5) measurements was consistently poorer than the reproducibility of cadaver measurements, presumably due to small movement artifacts and repositioning errors. Using 3D image registration, repositioning error was reduced on average by 23% and 8% for measurements of the radius and tibia sites, respectively. This study has provided bounds for the reproducibility of HR-pQCT to monitor bone quality longitudinally, and a basis for clinical study design to determine detectable changes.

  13. Problems of reproducibility--does geologically ancient DNA survive in amber-preserved insects?

    PubMed Central

    Austin, J J; Ross, A J; Smith, A B; Fortey, R A; Thomas, R H

    1997-01-01

    Apparently ancient DNA has been reported from amber-preserved insects many millions of years old. Rigorous attempts to reproduce these DNA sequences from amber- and copal-preserved bees and flies have failed to detect any authentic ancient insect DNA. Lack of reproducibility suggests that DNA does not survive over millions of years even in amber, the most promising of fossil environments. PMID:9149422

  14. Reproducibility of Heart Rate Variability Indices in Children with Cystic Fibrosis

    PubMed Central

    2016-01-01

    Fundamental to the potential utilisation of heart rate variability (HRV) indices as a prognostic tool is the reproducibility of these measures. The purpose of the present study was therefore to investigate the reproducibility of 24-hour derived HRV indices in a clinical paediatric population. Eighteen children (10 boys; 12.4 ± 2.8 years) with mild to moderate Cystic Fibrosis (CF; FVC: 83 ± 12% predicted; FEV1: 80 ± 9% predicted) and eighteen age- and sex-matched controls (10 boys; 12.5 ± 2.7 years) wore a combined ECG and accelerometer for two consecutive days. Standard time and frequency domain indices of HRV were subsequently derived. Reproducibility was assessed by Bland-Altman plots, 95% limits of agreement and intra-class correlation coefficients (ICC). In both groups, there was no systematic difference between days, with the variables demonstrating a symmetrical, homoscedastic distribution around the zero line. The time domain parameters demonstrated a good to excellent reproducibility irrespective of the population considered (ICC: 0.56 to 0.86). In contrast, whilst the frequency domain parameters similarly showed excellent reproducibility in the healthy children (ICC: 0.70 to 0.96), the majority of the frequency domain parameters illustrated a poor to moderate reproducibility in those with CF (ICC: 0.22 to 0.43). The exceptions to this trend were the normalised LF and HF components which were associated with a good to excellent reproducibility. These findings thereby support the utilisation of time and relative frequency domain HRV indices as a prognostic tool in children with CF. Furthermore, the present results highlight the excellent reproducibility of HRV in healthy children, indicating that this may be a useful tool to assess intervention effectiveness in this population. PMID:26968039

  15. Voxel-level reproducibility assessment of modality independent elastography in a pre-clinical murine model

    NASA Astrophysics Data System (ADS)

    Flint, Katelyn M.; Weis, Jared A.; Yankeelov, Thomas E.; Miga, Michael I.

    2015-03-01

    Changes in tissue mechanical properties, measured non-invasively by elastography methods, have been shown to be an important diagnostic tool, particularly for cancer. Tissue elasticity information, tracked over the course of therapy, may be an important prognostic indicator of tumor response to treatment. While many elastography techniques exist, this work reports on the use of a novel form of elastography that uses image texture to reconstruct elastic property distributions in tissue (i.e., a modality independent elastography (MIE) method) within the context of a pre-clinical breast cancer system.1,2 The elasticity results have previously shown good correlation with independent mechanical testing.1 Furthermore, MIE has been successfully utilized to localize and characterize lesions in both phantom experiments and simulation experiments with clinical data.2,3 However, the reproducibility of this method has not been characterized in previous work. The goal of this study is to evaluate voxel-level reproducibility of MIE in a pre-clinical model of breast cancer. Bland-Altman analysis of co-registered repeat MIE scans in this preliminary study showed a reproducibility index of 24.7% (scaled to a percent of maximum stiffness) at the voxel level. As opposed to many reports in the magnetic resonance elastography (MRE) literature that speak to reproducibility measures of the bulk organ, these results establish MIE reproducibility at the voxel level; i.e., the reproducibility of locally-defined mechanical property measurements throughout the tumor volume.

  16. Reproducibility of techniques using Archimedes' principle in measuring cancellous bone volume.

    PubMed

    Zou, L; Bloebaum, R D; Bachus, K N

    1997-01-01

    Researchers have been interested in developing techniques to accurately and reproducibly measure the volume fraction of cancellous bone. Historically bone researchers have used Archimedes' principle with water to measure the volume fraction of cancellous bone. Preliminary results in our lab suggested that the calibrated water technique did not provide reproducible results. Because of this difficulty, it was decided to compare the conventional water method to a water with surfactant and a helium method using a micropycnometer. The water/surfactant and the helium methods were attempts to improve the fluid penetration into the small voids present in the cancellous bone structure. In order to compare the reproducibility of the new methods with the conventional water method, 16 cancellous bone specimens were obtained from femoral condyles of human and greyhound dog femora. The volume fraction measurements on each specimen were repeated three times with all three techniques. The results showed that the helium displacement method was more than an order of magnitudes more reproducible than the two other water methods (p < 0.05). Statistical analysis also showed that the conventional water method produced the lowest reproducibility (p < 0.05). The data from this study indicate that the helium displacement technique is a very useful, rapid and reproducible tool for quantitatively characterizing anisotropic porous tissue structures such as cancellous bone.

  17. Adverse Reactions to Foods and Food Allergy: Development and Reproducibility of a Questionnaire for Clinical Diagnosis

    PubMed Central

    Lyra, Nilza R. S.; Motta, Maria E. F. A.; Rocha, Luiz A. R.; Solé, Dirceu; Peixoto, Décio M.; Rizzo, José A.; Taborda-Barata, Luis; Sarinho, Emanuel S. C.

    2013-01-01

    Objective. To develop a questionnaire as a screening tool for adverse reactions to foods in children and to assess the technical reproducibility by test-retest. Methods. Reproducibility of the questionnaire was performed by the literature review, preparing the preliminary questionnaire, peer review, pretest, and retest analysis. The study of the test-retest reproducibility was cross-sectional and descriptive. Kappa coefficient was used to study the reproducibility of the questionnaire. The sample consisted of 125 2–4 year-old children from 15 daycare centers in Recife, Brazil, and interviews with parents or caregivers were used to collect data. Results. From the total children, sixty-three were boys (50.4%), forty-six were two years old (36.8%), forty-seven were three years old (37.6%), and thirty-two were four years old (25.6%). Forty caregivers reported that their child had health problems with food. Most frequently reported offending foods were milk, peanuts, shrimp, and chocolate. Nine questions showed a good Kappa index (≥0,6). Conclusions. The questionnaire used needs to be resized and reshaped on the basis of the issues with good internal consistency and reproducibility. The use of a validated and reproducible questionnaire in the children represents an important contribution towards assessing an eventual rise in overt food allergy. PMID:24198840

  18. Methods to increase reproducibility in differential gene expression via meta-analysis

    PubMed Central

    Sweeney, Timothy E.; Haynes, Winston A.; Vallania, Francesco; Ioannidis, John P.; Khatri, Purvesh

    2017-01-01

    Findings from clinical and biological studies are often not reproducible when tested in independent cohorts. Due to the testing of a large number of hypotheses and relatively small sample sizes, results from whole-genome expression studies in particular are often not reproducible. Compared to single-study analysis, gene expression meta-analysis can improve reproducibility by integrating data from multiple studies. However, there are multiple choices in designing and carrying out a meta-analysis. Yet, clear guidelines on best practices are scarce. Here, we hypothesized that studying subsets of very large meta-analyses would allow for systematic identification of best practices to improve reproducibility. We therefore constructed three very large gene expression meta-analyses from clinical samples, and then examined meta-analyses of subsets of the datasets (all combinations of datasets with up to N/2 samples and K/2 datasets) compared to a ‘silver standard’ of differentially expressed genes found in the entire cohort. We tested three random-effects meta-analysis models using this procedure. We showed relatively greater reproducibility with more-stringent effect size thresholds with relaxed significance thresholds; relatively lower reproducibility when imposing extraneous constraints on residual heterogeneity; and an underestimation of actual false positive rate by Benjamini–Hochberg correction. In addition, multivariate regression showed that the accuracy of a meta-analysis increased significantly with more included datasets even when controlling for sample size. PMID:27634930

  19. Modest validity and fair reproducibility of dietary patterns derived by cluster analysis.

    PubMed

    Funtikova, Anna N; Benítez-Arciniega, Alejandra A; Fitó, Montserrat; Schröder, Helmut

    2015-03-01

    Cluster analysis is widely used to analyze dietary patterns. We aimed to analyze the validity and reproducibility of the dietary patterns defined by cluster analysis derived from a food frequency questionnaire (FFQ). We hypothesized that the dietary patterns derived by cluster analysis have fair to modest reproducibility and validity. Dietary data were collected from 107 individuals from population-based survey, by an FFQ at baseline (FFQ1) and after 1 year (FFQ2), and by twelve 24-hour dietary recalls (24-HDR). Repeatability and validity were measured by comparing clusters obtained by the FFQ1 and FFQ2 and by the FFQ2 and 24-HDR (reference method), respectively. Cluster analysis identified a "fruits & vegetables" and a "meat" pattern in each dietary data source. Cluster membership was concordant for 66.7% of participants in FFQ1 and FFQ2 (reproducibility), and for 67.0% in FFQ2 and 24-HDR (validity). Spearman correlation analysis showed reasonable reproducibility, especially in the "fruits & vegetables" pattern, and lower validity also especially in the "fruits & vegetables" pattern. κ statistic revealed a fair validity and reproducibility of clusters. Our findings indicate a reasonable reproducibility and fair to modest validity of dietary patterns derived by cluster analysis.

  20. Inter-rater agreement in evaluation of disability: systematic review of reproducibility studies

    PubMed Central

    Barth, Jürgen; de Boer, Wout E L; Busse, Jason W; Hoving, Jan L; Kedzia, Sarah; Couban, Rachel; Fischer, Katrin; von Allmen, David Y; Spanjer, Jerry

    2017-01-01

    Objectives To explore agreement among healthcare professionals assessing eligibility for work disability benefits. Design Systematic review and narrative synthesis of reproducibility studies. Data sources Medline, Embase, and PsycINFO searched up to 16 March 2016, without language restrictions, and review of bibliographies of included studies. Eligibility criteria Observational studies investigating reproducibility among healthcare professionals performing disability evaluations using a global rating of working capacity and reporting inter-rater reliability by a statistical measure or descriptively. Studies could be conducted in insurance settings, where decisions on ability to work include normative judgments based on legal considerations, or in research settings, where decisions on ability to work disregard normative considerations.Teams of paired reviewers identified eligible studies, appraised their methodological quality and generalisability, and abstracted results with pretested forms. As heterogeneity of research designs and findings impeded a quantitative analysis, a descriptive synthesis stratified by setting (insurance or research) was performed. Results From 4562 references, 101 full text articles were reviewed. Of these, 16 studies conducted in an insurance setting and seven in a research setting, performed in 12 countries, met the inclusion criteria. Studies in the insurance setting were conducted with medical experts assessing claimants who were actual disability claimants or played by actors, hypothetical cases, or short written scenarios. Conditions were mental (n=6, 38%), musculoskeletal (n=4, 25%), or mixed (n=6, 38%). Applicability of findings from studies conducted in an insurance setting to real life evaluations ranged from generalisable (n=7, 44%) and probably generalisable (n=3, 19%) to probably not generalisable (n=6, 37%). Median inter-rater reliability among experts was 0.45 (range intraclass correlation coefficient 0.86 to κ−0

  1. [Thin-layer chromatographic demonstration of the herbicide zenkor].

    PubMed

    Tsvetkova, Ts; Sergeeva, D; Grigorova, D

    1976-01-01

    Established were the thin-layer chromatography conditions for the demonstration of the herbicide Zenkor as a pure substance and a preparation. Comparative experiments were carried out applying Thomson and Stanley's thin-layer chromatography conditions and the authors' personal ones. Most adequate proved to be the following conditions: sorbent-Kieselgel 60F 254 (Merck); solvent -- chloroform: 1,4-dioxan (9:1); developer -- ultraviolet light (authors' technique). Essential with this method is the preliminary (prior to apply the pure substances on the thin-layer chromatographic plaque) moving of the plaque in the indicated mobile phase (authors' technique). Under these thin-layer chromatography conditions work is made feasible and the method is fast and simple, achieving high sensitivity -- 0.5 mug Zenkor.

  2. Advanced thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Kreider, K. G.; Semancik, S.; Olson, C.

    1984-01-01

    The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

  3. Shear-thinning Fluid

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Whipped cream and the filling for pumpkin pie are two familiar materials that exhibit the shear-thinning effect seen in a range of industrial applications. It is thick enough to stand on its own atop a piece of pie, yet flows readily when pushed through a tube. This demonstrates the shear-thinning effect that was studied with the Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002. CVX observed the behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The principal investigator was Dr. Robert Berg of the National Institutes of Standards and Technology in Gaithersburg, MD.

  4. Gratings Fabricated on Flat Surfaces and Reproduced on Non-Flat Substrates

    NASA Technical Reports Server (NTRS)

    Content, David; Iazikov, Dmitri; Mossberg, Thomas W.; Greiner, Christopher M.

    2009-01-01

    A method has been developed for fabricating gratings on flat substrates, and then reproducing the groove pattern on a curved (concave or convex) substrate and a corresponding grating device. First, surface relief diffraction grating grooves are formed on flat substrates. For example, they may be fabricated using photolithography and reactive ion etching, maskless lithography, holography, or mechanical ruling. Then, an imprint of the grating is made on a deformable substrate, such as plastic, polymer, or other materials using thermoforming, hot or cold embossing, or other methods. Interim stamps using electroforming, or other methods, may be produced for the imprinting process or if the same polarity of the grating image is required. The imprinted, deformable substrate is then attached to a curved, rigid substrate using epoxy or other suitable adhesives. The imprinted surface is facing away from the curved rigid substrate. As an alternative fabrication method, after grating is imprinted on the deformable substrate as described above, the grating may be coated with thin conformal conductive layer (for example, using vacuum deposition of gold). Then the membrane may be mounted over an opening in a pressured vessel in a manner of a membrane on a drum, grating side out. The pressure inside of the vessel may be changed with respect to the ambient pressure to produce concave or convex membrane surface. The shape of the opening may control the type of the surface curvature (for example, a circular opening would create spherical surface, oval opening would create toroidal surface, etc.). After that, well-known electroforming methods may be used to create a replica of the grating on the concave or convex membrane. For example, the pressure vessel assembly may be submerged into an electro-forming solution and negative electric potential applied to the metal coated membrane using an insulated wire. Positive electric potential may be then applied to a nickel or other metal

  5. Thin film superconductor magnetic bearings

    DOEpatents

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  6. Childhood Obesity and Cognitive Achievement.

    PubMed

    Black, Nicole; Johnston, David W; Peeters, Anna

    2015-09-01

    Obese children tend to perform worse academically than normal-weight children. If poor cognitive achievement is truly a consequence of childhood obesity, this relationship has significant policy implications. Therefore, an important question is to what extent can this correlation be explained by other factors that jointly determine obesity and cognitive achievement in childhood? To answer this question, we exploit a rich longitudinal dataset of Australian children, which is linked to national assessments in math and literacy. Using a range of estimators, we find that obesity and body mass index are negatively related to cognitive achievement for boys but not girls. This effect cannot be explained by sociodemographic factors, past cognitive achievement or unobserved time-invariant characteristics and is robust to different measures of adiposity. Given the enormous importance of early human capital development for future well-being and prosperity, this negative effect for boys is concerning and warrants further investigation.

  7. Using Design To Achieve Sustainability

    EPA Science Inventory

    Sustainability is defined as meeting the needs of this generation without compromising the ability of future generations to meet their needs. This is a conditional statement that places the responsibility for achieving sustainability squarely in hands of designers and planners....

  8. Thin, Lightweight Solar Cell

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Weinberg, Irving

    1991-01-01

    Improved design for thin, lightweight solar photovoltaic cells with front contacts reduces degradation of electrical output under exposure to energetic charged particles (protons and electrons). Increases ability of cells to maintain structural integrity under exposure to ultraviolet radiation by eliminating ultraviolet-degradable adhesives used to retain cover glasses. Interdigitated front contacts and front junctions formed on semiconductor substrate. Mating contacts formed on back surface of cover glass. Cover glass and substrate electrostatically bonded together.

  9. Thin film composite electrolyte

    DOEpatents

    Schucker, Robert C.

    2007-08-14

    The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

  10. Achieving Efficiencies in Army Installations.

    DTIC Science & Technology

    2007-11-02

    34" ’■■"■" 1 USAWC STRATEGY RESEARCH PROJECT Achieving Efficiencies in Army Installations by Richard Fliss Col. Richard M. Meinhart Project...government agency. STRATEGY RESEARCH PROJECT ACHIEVING EFFICIENCIES IN ARMY INSTALLATIONS BY RICHARD FLISS DISTRIBUTION STATEMENT A: Approved...for public release. Distribution is unlimited. DTIC QUALITY INSPECTED & USAWC CLASS OF 1998 U.S. ARMY WAR COLLEGE, CARLISLE BARRACKS, PA 17013-5050

  11. Sputter deposition of metallic thin film and directpatterning

    SciTech Connect

    Ji, L.; Chen, Y.; Jiang, X.; Ji, Q.; Leung, K.-N.

    2005-09-09

    A compact apparatus is developed for deposition of metal thin film. The system employs an RF discharge plasma source with a straight RF antenna, which is made of or covered with deposition material, serving as sputtering target at the same time. The average deposition rate of copper thin film is as high as 450nm/min. By properly allocating the metal materials on the sputtering antenna, mixture deposition of multiple metal species is achieved. Using an ion beam imprinting scheme also taking advantage of ion beam focusing technique, two different schemes of direct patterning deposition process are developed: direct depositing patterned metallic thin film and resistless ion beam sputter patterning. Preliminary experiments have demonstrated direct pattern transfer from a template with feature size of micro scale; patterns with more than 10x reduction are achieved by sputtering patterning method.

  12. Development of an efficient high-performance thin layer chromatography method for determination of jasmonic acid in leaf tissue of Stevia rebaudiana (Bertoni) Bertoni.

    PubMed

    Kilam, Divya; Saifi, M; Agnihotri, A; Abdin, M Z

    2017-02-13

    Determination of endogenous levels of jasmonic acid (JA) is essential, as it plays a pivotal role in the physiological processes during a plant's life cycle. A high performance thin layer chromatography (HPTLC) method was developed for the detection and quantification of JA in leaf extracts of medicinal plant, Stevia rebaudiana (Bertoni) Bertoni. The separation was achieved using the solvents ethyl acetate-benzene (1:1, v/v) as the mobile phase, followed by scanning and quantification at 295 nm. Densitometric analysis of leaf extract resulted in compact spots for JA at Rf = 0.45 ± 0.02. The linear regression analysis showed good relationship with r value. The recovery rate of JA indicated good reproducibility and repeatability of the assay. The statistical analysis proved the reproducibility of the method; therefore, it can be employed for routine quantification of JA in different tissue samples of S. rebaudiana and may also be extrapolated to other biological samples.

  13. Role of Polycrystalline Thin-Film PV Technologies in Competitive PV Module Markets: Preprint

    SciTech Connect

    von Roedern, B.; Ullal, H. S.

    2008-05-01

    This paper discusses the developments in thin-film PV technologies and provides an outlook on future commercial module efficiencies achievable based on today's knowledge about champion cell performance.

  14. Near atomically smooth alkali antimonide photocathode thin films

    NASA Astrophysics Data System (ADS)

    Feng, Jun; Karkare, Siddharth; Nasiatka, James; Schubert, Susanne; Smedley, John; Padmore, Howard

    2017-01-01

    Nano-roughness is one of the major factors degrading the emittance of electron beams that can be generated by high efficiency photocathodes, such as the thermally reacted alkali antimonide thin films. In this paper, we demonstrate a co-deposition based method for producing alkali antimonide cathodes that produce near atomic smoothness with high reproducibility. We calculate the effect of the surface roughness on the emittance and show that such smooth cathode surfaces are essential for operation of alkali antimonide cathodes in high field, low emittance radio frequency electron guns and to obtain ultracold electrons for ultrafast electron diffraction applications.

  15. Method and apparatus for determining weldability of thin sheet metal

    DOEpatents

    Goodwin, Gene M.; Hudson, Joseph D.

    1988-01-01

    A fixture is provided for testing thin sheet metal specimens to evaluate hot-cracking sensitivity for determining metal weldability on a heat-to-heat basis or through varying welding parameters. A test specimen is stressed in a first direction with a load selectively adjustable over a wide range and then a weldment is passed along over the specimen in a direction transverse to the direction of strain to evaluate the hot-cracking characteristics of the sheet metal which are indicative of the weldability of the metal. The fixture provides evaluations of hot-cracking sensitivity for determining metal weldability in a highly reproducible manner with minimum human error.

  16. Organic Semiconducting Thin Films: Device Applications and Beyond

    NASA Astrophysics Data System (ADS)

    Stemer, Dominik

    Organic semiconductors show great promise for device applications, particularly as organic thin film transistors (OTFTs) and organic photovoltaics (OPVs), due to their potential for low cost, high volume fabrication when compared to traditional inorganic semiconductors. While the performance of organic devices generally lags behind the more established inorganic devices, significant growth in the field of organic semiconductors has led to rapid improvements. In this thesis, device operation and characterization of OTFT and OPV systems are explained, the dramatic effects of fabrication procedures on the charge transport performance of OTFTs are demonstrated, and the reproducibility issues inherent to OPVs are explored. The potential for self-healing behavior in organic semiconductors is also investigated.

  17. Banff Initiative for Quality Assurance in Transplantation (BIFQUIT): Reproducibility of Polyomavirus Immunohistochemistry in Kidney Allografts

    PubMed Central

    Adam, Benjamin; Randhawa, Parmjeet; Chan, Samantha; Zeng, Gang; Regele, Heinz; Kushner, Yael B.; Colvin, Robert B.; Reeve, Jeff; Mengel, Michael

    2014-01-01

    Immunohistochemistry is the gold standard for diagnosing (positive versus negative) polyomavirus BK (BKV) nephropathy and has the potential for disease staging based on staining intensity and quantification of infected cells. This multicenter trial evaluated the reproducibility of BKV immunohistochemistry among 81 pathologists at 60 institutions. Participants stained tissue microarray slides and scored them for staining intensity and percentage of positive nuclei. Staining protocol details and evaluation scores were collected online. Slides were returned for centralized panel re-evaluation and kappa statistics were calculated. Individual assessment of staining intensity and percentage was more reproducible than combined scoring. Inter-institutional reproducibility was moderate for staining intensity (κ=0.49) and percentage (κ=0.42), fair for combined (κ=0.25), and best for simple positive/negative scoring (κ=0.63). Inter-observer reproducibility was substantial for intensity (κ=0.74), percentage (κ=0.66), and positive/negative (κ=0.67), and moderate for combined scoring (κ=0.43). Inter-laboratory reproducibility was fair for intensity (κ=0.37), percentage (κ=0.40), and combined (κ=0.24), but substantial for positive/negative scoring (κ=0.78). BKV RNA copies/cell correlated with staining intensity (r=0.56) and percentage (r=0.62). These results indicate that BKV immunohistochemistry is reproducible between observers but scoring should be simplified to a single-feature schema. Standardization of tissue processing and staining protocols would further improve inter-laboratory reproducibility. PMID:25091177

  18. Practical applications of thin films nanostructured by shadowing growth

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi

    2012-10-01

    Even prior to the recent advent of advanced top-down processes, shadowing growth by oblique angle deposition (OAD) has long been providing self-assembled nanostructures over much larger areas for much lower costs. In the past two decades, significant progress has been made in the development of well-controlled three-dimensional nanomorphologies such as zigzags and helixes. Much effort has been put into theoretical and numerical understanding of the growth mechanism to improve morphology. Many researchers in academia have been investigating useful properties of nanocolumnar thin films in their laboratories. However, most companies seem hesitant to introduce OAD techniques into the factory owing to the prejudice that the OAD thin films are neither durable nor reproducible. In this review article, we discuss the progress in OAD technology for practical applications.

  19. Thin Film Nanomorphology Tailored by Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi

    Shadowing growth by glancing angle deposition (GLAD) has been providing self-assembled nanostructures over much larger area for much lower costs since much earlier than the recent advanced top down processes do. In these two decades, significant progress has been made in the development of the well-controlled 3D nanomorphologies such as zigzag and helix. Much effort for theoretical and numerical understanding of the growth mechanism has been also paid in order to improve the morphology. Many researches in academia have been investigating useful properties of nanocolumnar thin films in their laboratory. On the other hand, most companies seem hesitate to introduce GLAD technique into the factory due to the prejudice that the obliquely deposited thin films are not durable and reproducible. In this article, we discuss the progress in glancing angle deposition technology for the practical applications.

  20. Practical applications of thin films nanostructured by shadowing growth

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi

    2013-01-01

    Even prior to the recent advent of advanced top-down processes, shadowing growth by oblique angle deposition (OAD) has long been providing self-assembled nanostructures over much larger areas for much lower costs. In the past two decades, significant progress has been made in the development of well-controlled three-dimensional nanomorphologies such as zigzags and helixes. Much effort has been put into theoretical and numerical understanding of the growth mechanism to improve morphology. Many researchers in academia have been investigating useful properties of nanocolumnar thin films in their laboratories. However, most companies seem hesitant to introduce OAD techniques into the factory, owing to the prejudice that the OAD thin films are neither durable nor reproducible. The progress in OAD technology for practical applications is reviewed and discussed.