Aerosol Direct Radiative Effects and Heating in the New Era of Active Satellite Observations

NASA Astrophysics Data System (ADS)

Matus, Alexander V.

Atmospheric aerosols impact the global energy budget by scattering and absorbing solar radiation. Despite their impacts, aerosols remain a significant source of uncertainty in our ability to predict future climate. Multi-sensor observations from the A-Train satellite constellation provide valuable observational constraints necessary to reduce uncertainties in model simulations of aerosol direct effects. This study will discuss recent efforts to quantify aerosol direct effects globally and regionally using CloudSat's radiative fluxes and heating rates product. Improving upon previous techniques, this approach leverages the capability of CloudSat and CALIPSO to retrieve vertically resolved estimates of cloud and aerosol properties critical for accurately evaluating the radiative impacts of aerosols. We estimate the global annual mean aerosol direct effect to be -1.9 +/- 0.6 W/m2, which is in better agreement with previously published estimates from global models than previous satellite-based estimates. Detailed comparisons against a fully coupled simulation of the Community Earth System Model, however, reveal that this agreement on the global annual mean masks large regional discrepancies between modeled and observed estimates of aerosol direct effects related to model biases in cloud cover. A low bias in stratocumulus cloud cover over the southeastern Pacific Ocean, for example, leads to an overestimate of the radiative effects of marine aerosols. Stratocumulus clouds over the southeastern Atlantic Ocean can enhance aerosol absorption by 50% allowing aerosol layers to remain self-lofted in an area of subsidence. Aerosol heating is found to peak at 0.6 +/- 0.3 K/day an altitude of 4 km in September when biomass burning reaches a maximum. Finally, the contributions of observed aerosols components are evaluated to estimate the direct radiative forcing of anthropogenic aerosols. Aerosol forcing is computed using satellite-based radiative kernels that describe the

Plasmon Surface Polariton Dispersion by Direct Optical Observation.

ERIC Educational Resources Information Center

Swalen, J. D.; And Others

1980-01-01

Describes several simple experiments that can be used to observe directly the dispersion curve of plasmon surface polaritons (PSP) on flat metal surfaces. A method is described of observing the increonental change in the wave vector of the PSP due to coatings that differ in thickness by a few nanometers. (Author/CS)

New Directions: Emerging Satellite Observations of Above-cloud Aerosols and Direct Radiative Forcing

NASA Technical Reports Server (NTRS)

Yu, Hongbin; Zhang, Zhibo

2013-01-01

Spaceborne lidar and passive sensors with multi-wavelength and polarization capabilities onboard the A-Train provide unprecedented opportunities of observing above-cloud aerosols and direct radiative forcing. Significant progress has been made in recent years in exploring these new aerosol remote sensing capabilities and generating unique datasets. The emerging observations will advance the understanding of aerosol climate forcing.

An Unroofing Method to Observe the Cytoskeleton Directly at Molecular Resolution Using Atomic Force Microscopy

PubMed Central

Usukura, Eiji; Narita, Akihiro; Yagi, Akira; Ito, Shuichi; Usukura, Jiro

2016-01-01

An improved unroofing method enabled the cantilever of an atomic force microscope (AFM) to reach directly into a cell to visualize the intracellular cytoskeletal actin filaments, microtubules, clathrin coats, and caveolae in phosphate-buffered saline (PBS) at a higher resolution than conventional electron microscopy. All of the actin filaments clearly exhibited a short periodicity of approximately 5–6 nm, which was derived from globular actins linked to each other to form filaments, as well as a long helical periodicity. The polarity of the actin filaments appeared to be determined by the shape of the periodic striations. Microtubules were identified based on their thickness. Clathrin coats and caveolae were observed on the cytoplasmic surface of cell membranes. The area containing clathrin molecules and their terminal domains was directly visualized. Characteristic ridge structures located at the surface of the caveolae were observed at high resolution, similar to those observed with electron microscopy (EM). Overall, unroofing allowed intracellular AFM imaging in a liquid environment with a level of quality equivalent or superior to that of EM. Thus, AFMs are anticipated to provide cutting-edge findings in cell biology and histology. PMID:27273367

Routine hand hygiene audit by direct observation: has nemesis arrived?

PubMed

Gould, D J; Drey, N S; Creedon, S

2011-04-01

Infection prevention and control experts have expended valuable health service time developing and implementing tools to audit health workers' hand hygiene compliance by direct observation. Although described as the 'gold standard' approach to hand hygiene audit, this method is labour intensive and may be inaccurate unless performed by trained personnel who are regularly monitored to ensure quality control. New technological devices have been developed to generate 'real time' data, but the cost of installing them and using them during routine patient care has not been evaluated. Moreover, they do not provide as much information about the hand hygiene episode or the context in which hand hygiene has been performed as direct observation. Uptake of hand hygiene products offers an inexpensive alternative to direct observation. Although product uptake would not provide detailed information about the hand hygiene episode or local barriers to compliance, it could be used as a continuous monitoring tool. Regular inspection of the data by infection prevention and control teams and clinical staff would indicate when and where direct investigation of practice by direct observation and questioning of staff should be targeted by highly trained personnel to identify local problems and improve practice. Copyright © 2011 the Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Direct Observation of Two Proton Radioactivity Using Digital Photography

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

Rykaczewski, Krzysztof Piotr; Pfutzner, M.; Dominik, Wojciech

2007-01-01

Recently the observation of a new type of spontaneous radioactive decay has been claimed in which two protons are simultaneously ejected by an atomic nucleus from the ground state1,2,3. Experimental data obtained for the extremely neutron-deficient nuclei 45Fe and 54Zn, were interpreted as the first evidence of such a decay mode which has been sought since 1960.4 However, the technique applied in those studies allowed only measurements of the decay time and the total energy released. Particles emitted in the decay were not identified and the conclusions had to be supported by theoretical arguments. Here we show for the firstmore » time, directly and unambiguously, that 45Fe indeed disintegrates by two-proton decay. Furthermore, we demonstrate that the decay branch of this isotope leads to various particle emission channels including two-proton and three-proton emission. To achieve this result we have developed a new type of detector V the Optical Time Projection Chamber (OTPC) in which digital photography is applied to nuclear physics for the first time. The detector records images of tracks from charged particles, allowing for their unambiguous identification and the reconstruction of decay events in three dimensions. This new and simple technique provides a powerful method to identify exotic decay channels involving emission of charged particles. It is expected that further studies with the OTPC device will yield important information on nuclei located at and beyond the proton drip-line, thus providing new material for testing and improving models of very unstable atomic nuclei.« less

Direct observation of shear piezoelectricity in poly-l-lactic acid nanowires

NASA Astrophysics Data System (ADS)

Smith, Michael; Calahorra, Yonatan; Jing, Qingshen; Kar-Narayan, Sohini

2017-07-01

Piezoelectric polymers are capable of interconverting mechanical and electrical energy, and are therefore candidate materials for biomedical applications such as sensors, actuators, and energy harvesters. In particular, nanowires of these materials are attractive as they can be unclamped, flexible and sensitive to small vibrations. Poly-l-lactic acid (PLLA) nanowires have been investigated for their use in biological applications, but their piezoelectric properties have never been fully characterised, even though macroscopic films and fibres have been shown to exhibit shear piezoelectricity. This piezoelectric mode is particularly interesting for in vivo applications where shear forces are especially relevant, and is similar to what has been observed in natural materials such as bone and DNA. Here, using piezo-response force microscopy (PFM), we report the first direct observation of shear piezoelectricity in highly crystalline and oriented PLLA nanowires grown by a novel template-wetting method. Our results are validated using finite-element simulations and numerical analysis, which importantly and more generally allow for accurate interpretation of PFM signals in soft nanostructured materials. Our work opens up the possibility for the development of biocompatible and sustainable piezoelectric nanogenerators and sensors based on polymer nanowires.

42 CFR 405.2468 - Allowable costs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to the limit on the all-inclusive rate for allowable costs. (3) Allowable graduate medical education.... (f) Graduate medical education. (1) Effective for that portion of cost reporting periods occurring on... receive direct graduate medical education payment for those residents. (2) Direct graduate medical...

10 CFR 26.115 - Collecting a urine specimen under direct observation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Collecting a urine specimen under direct observation. 26.115 Section 26.115 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.115 Collecting a urine specimen under direct observation. (a) Procedures for...

10 CFR 26.115 - Collecting a urine specimen under direct observation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Collecting a urine specimen under direct observation. 26.115 Section 26.115 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.115 Collecting a urine specimen under direct observation. (a) Procedures for...

10 CFR 26.115 - Collecting a urine specimen under direct observation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Collecting a urine specimen under direct observation. 26.115 Section 26.115 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.115 Collecting a urine specimen under direct observation. (a) Procedures for...

10 CFR 26.115 - Collecting a urine specimen under direct observation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Collecting a urine specimen under direct observation. 26.115 Section 26.115 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.115 Collecting a urine specimen under direct observation. (a) Procedures for...

10 CFR 26.115 - Collecting a urine specimen under direct observation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Collecting a urine specimen under direct observation. 26.115 Section 26.115 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.115 Collecting a urine specimen under direct observation. (a) Procedures for...

Direct Observations of Clouds on Brown Dwarfs: A Spitzer Study of Extreme Cases

NASA Astrophysics Data System (ADS)

Burgasser, Adam; Cruz, Kelle; Cushing, Michael; Kirkpatrick, J. Davy; Looper, Dagny; Lowrance, Patrick; Marley, Mark; Saumon, Didier

2008-03-01

Clouds play a fundamental role in the emergent spectral energy distributions and observed variability of very low mass stars and brown dwarfs, yet hey have only been studied indirectly thus far. Recent indications of a broad silicate grain absorption feature in the 8-11 micron spectra of mid-type L dwarfs, and evidence that the strength of this absorption varies according to broad-band near-infrared color, may finally allow the first direct studies of clouds and condensate grain properties in brown dwarf atmospheres. We propose to observe a sample of 18 ``extreme'' L dwarfs - objects with unusually blue and red near-infrared colors - with IRAC and IRS to study the 8-11 micron feature in detail (including grain size distributions and bulk compositions), and to constrain advanced condensate cloud atmosphere models currently in development. Our program provides a unique examination of the general processes of cloud formation by focusing on the relatively warm photospheres of late-type brown dwarfs.

The Tangle of Student Allowances.

ERIC Educational Resources Information Center

Thomson, Norman J.

1980-01-01

A discussion of the distribution of student financial aid in Australia focuses on these issues: direct vs. indirect payment to students; inequality in living allowances given to secondary and postsecondary students; and distribution of expense allowances by state government and living allowances by the Commonwealth. (MSE)

Direct observation of lubricant additives using tomography techniques

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

Chen, Yunyun; Sanchez, Carlos; Parkinson, Dilworth Y.

Lubricants play important roles in daily activities such as driving, walking, and cooking. The current understanding of mechanisms of lubrication, particularly in mechanical systems, has been limited by the lack of capability in direct observation. Here, we report an in situ approach to directly observe the motion of additive particles in grease under the influence of shear. Using the K-edge tomography technique, it is possible to detect particular additives in a grease and observe their distribution through 3D visualization. A commercial grease as a reference was studied with and without an inorganic additive of Fe{sub 3}O{sub 4} microparticles. The resultsmore » showed that it was possible to identify these particles and track their movement. Under a shear stress, Fe{sub 3}O{sub 4} particles were found to adhere to the edge of calcium complex thickeners commonly used in grease. Due to sliding, the grease formed a film with increased density. This approach enables in-line monitoring of a lubricant and future investigation in mechanisms of lubrication.« less

Assessing distractors and teamwork during surgery: developing an event-based method for direct observation.

PubMed

Seelandt, Julia C; Tschan, Franziska; Keller, Sandra; Beldi, Guido; Jenni, Nadja; Kurmann, Anita; Candinas, Daniel; Semmer, Norbert K

2014-11-01

To develop a behavioural observation method to simultaneously assess distractors and communication/teamwork during surgical procedures through direct, on-site observations; to establish the reliability of the method for long (>3 h) procedures. Observational categories for an event-based coding system were developed based on expert interviews, observations and a literature review. Using Cohen's κ and the intraclass correlation coefficient, interobserver agreement was assessed for 29 procedures. Agreement was calculated for the entire surgery, and for the 1st hour. In addition, interobserver agreement was assessed between two tired observers and between a tired and a non-tired observer after 3 h of surgery. The observational system has five codes for distractors (door openings, noise distractors, technical distractors, side conversations and interruptions), eight codes for communication/teamwork (case-relevant communication, teaching, leadership, problem solving, case-irrelevant communication, laughter, tension and communication with external visitors) and five contextual codes (incision, last stitch, personnel changes in the sterile team, location changes around the table and incidents). Based on 5-min intervals, Cohen's κ was good to excellent for distractors (0.74-0.98) and for communication/teamwork (0.70-1). Based on frequency counts, intraclass correlation coefficient was excellent for distractors (0.86-0.99) and good to excellent for communication/teamwork (0.45-0.99). After 3 h of surgery, Cohen's κ was 0.78-0.93 for distractors, and 0.79-1 for communication/teamwork. The observational method developed allows a single observer to simultaneously assess distractors and communication/teamwork. Even for long procedures, high interobserver agreement can be achieved. Data collected with this method allow for investigating separate or combined effects of distractions and communication/teamwork on surgical performance and patient outcomes. Published by the

Retinex Image Processing: Improved Fidelity To Direct Visual Observation

NASA Technical Reports Server (NTRS)

Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.

1996-01-01

Recorded color images differ from direct human viewing by the lack of dynamic range compression and color constancy. Research is summarized which develops the center/surround retinex concept originated by Edwin Land through a single scale design to a multi-scale design with color restoration (MSRCR). The MSRCR synthesizes dynamic range compression, color constancy, and color rendition and, thereby, approaches fidelity to direct observation.

Effects of walker gender and observer gender on biological motion walking direction discrimination.

PubMed

Yang, Xiaoying; Cai, Peng; Jiang, Yi

2014-09-01

The ability to recognize the movements of other biological entities, such as whether a person is walking toward you, is essential for survival and social interaction. Previous studies have shown that the visual system is particularly sensitive to approaching biological motion. In this study, we examined whether the gender of walkers and observers influenced the walking direction discrimination of approaching point-light walkers in fine granularity. The observers were presented a walker who walked in different directions and were asked to quickly judge the walking direction (left or right). The results showed that the observers demonstrated worse direction discrimination when the walker was depicted as male than when the walker was depicted as female, probably because the observers tended to perceive the male walkers as walking straight ahead. Intriguingly, male observers performed better than female observers at judging the walking directions of female walkers but not those of male walkers, a result indicating perceptual advantage with evolutionary significance. These findings provide strong evidence that the gender of walkers and observers modulates biological motion perception and that an adaptive perceptual mechanism exists in the visual system to facilitate the survival of social organisms. © 2014 The Institute of Psychology, Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Direct Observation of Virtual Electrode Formation Through a Novel Electrolyte-to-Electrode Transition

NASA Astrophysics Data System (ADS)

Siegel, David; El Gabaly, Farid; Bartelt, Norman; McCarty, Kevin

2014-03-01

Novel electrochemical solutions to problems in energy storage and transportation can drive renewable energy to become an economically viable alternative to fossil fuels. In many electrochemical systems, the behavior of a device can be fundamentally limited by the surface area of a triple phase boundary, the boundary region where a gas-phase species, electrode, and electrolyte coincide. When the electrode is an ionic insulator the triple phase boundary is typically a one-dimensional boundary with nanometer-scale thickness: ions cannot transport through the electrode, while electrons cannot be transported through the electrolyte. Here we present direct experimental measurements of a novel electrolyte-to-electrode transition with photoemission electron microscopy, and observe that the surface of an ionically conductive, electronically insulative solid oxide electrolyte undergoes a transition into a mixed electron-ion conductor in the vicinity of a metal electrode. Our direct experimental measurements allow us to characterize this system and address the mechanisms of ionic reactions and transport through comparisons with theoretical modeling to provide us with a physical picture of the processes involved. Our results provide insight into one of the mechanisms of ion transport in an electrochemical cell that may be generalizable to other systems.

Direct observation of multistep energy transfer in LHCII with fifth-order 3D electronic spectroscopy.

PubMed

Zhang, Zhengyang; Lambrev, Petar H; Wells, Kym L; Garab, Győző; Tan, Howe-Siang

2015-07-31

During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy is then funneled towards the reaction centre. These photosynthetic excitation energy transfer (EET) pathways are complex and proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) is an important tool to study EET processes in photosynthetic complexes. However, the multistep EET processes can only be indirectly inferred by correlating different cross peaks from a series of 2DES spectra. Here we directly observe multistep EET processes in LHCII using ultrafast fifth-order three-dimensional electronic spectroscopy (3DES). We measure cross peaks in 3DES spectra of LHCII that directly indicate energy transfer from excitons in the chlorophyll b (Chl b) manifold to the low-energy level chlorophyll a (Chl a) via mid-level Chl a energy states. This new spectroscopic technique allows scientists to move a step towards mapping the complete complex EET processes in photosynthetic systems.

Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules

NASA Astrophysics Data System (ADS)

Imai, Hiroshi; Shima, Tomohiro; Sutoh, Kazuo; Walker, Matthew L.; Knight, Peter J.; Kon, Takahide; Burgess, Stan A.

2015-09-01

Cytoplasmic dynein is a dimeric AAA+ motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA+ rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour.

Relation between Direct Observation of Relaxation and Self-Reported Mindfulness and Relaxation States

ERIC Educational Resources Information Center

Hites, Lacey S.; Lundervold, Duane A.

2013-01-01

Forty-four individuals, 18-47 (MN 21.8, SD 5.63) years of age, took part in a study examining the magnitude and direction of the relationship between self-report and direct observation measures of relaxation and mindfulness. The Behavioral Relaxation Scale (BRS), a valid direct observation measure of relaxation, was used to assess relaxed behavior…

Microcrack closure in rocks under stress - Direct observation

NASA Technical Reports Server (NTRS)

Batzle, M. L.; Simmons, G.; Siegfried, R. W.

1980-01-01

Direct observations of the closure of microcracks in rocks under increasing stress are reported. Uniaxial stresses up to 300 bars were applied to untreated and previously heated samples of Westerly granite and Frederick diabase by a small hydraulic press which fit entirely within a scanning electron microscope. Crack closure characteristics are found to depend on crack orientation, with cracks perpendicular to the applied stress closing and those parallel tending to open, as well as crack aspect ratio, crack intersection properties, stress concentrations and surface roughness. Uniaxial and hydrostatic stress measurements are found to be strongly dependent on fracture content as observed by SEM, and the observed hysteresis in strain measurements in the first stress cycles is also related to microscopic processes

Ethical aspects of directly observed treatment for tuberculosis: a cross-cultural comparison

PubMed Central

2013-01-01

Background Tuberculosis is a major global public health challenge, and a majority of countries have adopted a version of the global strategy to fight Tuberculosis, Directly Observed Treatment, Short Course (DOTS). Drawing on results from research in Ethiopia and Norway, the aim of this paper is to highlight and discuss ethical aspects of the practice of Directly Observed Treatment (DOT) in a cross-cultural perspective. Discussion Research from Ethiopia and Norway demonstrates that the rigid enforcement of directly observed treatment conflicts with patient autonomy, dignity and integrity. The treatment practices, especially when imposed in its strictest forms, expose those who have Tuberculosis to extra burdens and costs. Socially disadvantaged groups, such as the homeless, those employed as day labourers and those lacking rights as employees, face the highest burdens. Summary From an ethical standpoint, we argue that a rigid practice of directly observed treatment is difficult to justify, and that responsiveness to social determinants of Tuberculosis should become an integral part of the management of Tuberculosis. PMID:23819555

Direct observation of OH production from the ozonolysis of olefins

NASA Astrophysics Data System (ADS)

Donahue, Neil M.; Kroll, Jesse H.; Anderson, James G.; Demerjian, Kenneth L.

Ozone olefin reactions may be a significant source of OH in the urban atmosphere, but current evidence for OH production is indirect and contested. We report the first direct observation of OH radicals from the reaction of ozone with a series of olefins (ethene, isoprene, trans-2-butene and 2,3 dimethyl-2-butene) in 4-6 torr of nitrogen. Using LIF to directly observe the steady-state of OH produced by the initial ozone-olefin reaction and subsequently destroyed by the OH-olefin reaction, we are able to establish OH yields broadly consistent with indirect values. The identification of the OH is unequivocal, and there is no indication that it is produced by a secondary process. To support these observations, we present a complete ab-initio potential energy surface for the O3-ethene reaction, extending from the reactants to available products.

Direct observation of laser guided corona discharges

PubMed Central

Wang, Tie-Jun; Wei, Yingxia; Liu, Yaoxiang; Chen, Na; Liu, Yonghong; Ju, Jingjing; Sun, Haiyi; Wang, Cheng; Lu, Haihe; Liu, Jiansheng; Chin, See Leang; Li, Ruxin; Xu, Zhizhan

2015-01-01

Laser based lightning control holds a promising way to solve the problem of the long standing disaster of lightning strikes. But it is a challenging project due to insufficient understanding of the interaction between laser plasma channel and high voltage electric filed. In this work, a direct observation of laser guided corona discharge is reported. Laser filament guided streamer and leader types of corona discharges were observed. An enhanced ionization took place in the leader (filament) through the interaction with the high voltage discharging field. The fluorescence lifetime of laser filament guided corona discharge was measured to be several microseconds, which is 3 orders of magnitude longer than the fluorescence lifetime of laser filaments. This work could be advantageous towards a better understanding of laser assisted leader development in the atmosphere. PMID:26679271

A Springloaded Metal-Ligand Mesocate Allows Access to Trapped Intermediates of Self-Assembly.

PubMed

Bogie, Paul M; Holloway, Lauren R; Lyon, Yana; Onishi, Nicole C; Beran, Gregory J O; Julian, Ryan R; Hooley, Richard J

2018-04-02

A strained, "springloaded" Fe 2 L 3 iminopyridine mesocate shows highly variable reactivity upon postassembly reaction with competitive diamines. The strained assembly is reactive toward transimination in minutes at ambient temperature and allows observation of kinetically trapped intermediates in the self-assembly pathway. When diamines are used that can only form less favored cage products upon full equilibration, trapped ML 3 fragments with pendant, "hanging" NH 2 groups are selectively formed instead. Slight variations in diamine structure have large effects on the product outcome: less rigid diamines convert the mesocate to more favored self-assembled cage complexes under mild conditions and allow observation of heterocomplex intermediates in the displacement pathway. The mesocate allows control of equilibrium processes and direction of product outcomes via small, iterative changes in added subcomponent structure and provides a method of accessing metal-ligand cage structures not normally observed in multicomponent Fe-iminopyridine self-assembly.

Direct observation of the actin filament by tip-scan atomic force microscopy

PubMed Central

Narita, Akihiro; Usukura, Eiji; Yagi, Akira; Tateyama, Kiyohiko; Akizuki, Shogo; Kikumoto, Mahito; Matsumoto, Tomoharu; Maéda, Yuichiro; Ito, Shuichi; Usukura, Jiro

2016-01-01

Actin filaments, the actin–myosin complex and the actin–tropomyosin complex were observed by a tip-scan atomic force microscope (AFM), which was recently developed by Olympus as the AFM part of a correlative microscope. This newly developed AFM uses cantilevers of similar size as stage-scan AFMs to improve substantially the spatial and temporal resolution. Such an approach has previously never been possible by a tip-scan system, in which a cantilever moves in the x, y and z directions. We evaluated the performance of this developed tip-scan AFM by observing the molecular structure of actin filaments and the actin–tropomyosin complex. In the image of the actin filament, the molecular interval of the actin subunits (∼5.5 nm) was clearly observed as stripes. From the shape of the stripes, the polarity of the actin filament was directly determined and the results were consistent with the polarity determined by myosin binding. In the image of the actin–tropomyosin complex, each tropomyosin molecule (∼2 nm in diameter) on the actin filament was directly observed without averaging images of different molecules. Each tropomyosin molecule on the actin filament has never been directly observed by AFM or electron microscopy. Thus, our developed tip-scan AFM offers significant potential in observing purified proteins and cellular structures at nanometer resolution. Current results represent an important step in the development of a new correlative microscope to observe nm-order structures at an acceptable frame rate (∼10 s/frame) by AFM at the position indicated by the fluorescent dye observed under a light microscope. PMID:27242058

Emerging feed-forward inhibition allows the robust formation of direction selectivity in the developing ferret visual cortex

PubMed Central

Escobar, Gina M.; Maffei, Arianna; Miller, Paul

2014-01-01

The computation of direction selectivity requires that a cell respond to joint spatial and temporal characteristics of the stimulus that cannot be separated into independent components. Direction selectivity in ferret visual cortex is not present at the time of eye opening but instead develops in the days and weeks following eye opening in a process that requires visual experience with moving stimuli. Classic Hebbian or spike timing-dependent modification of excitatory feed-forward synaptic inputs is unable to produce direction-selective cells from unselective or weakly directionally biased initial conditions because inputs eventually grow so strong that they can independently drive cortical neurons, violating the joint spatial-temporal activation requirement. Furthermore, without some form of synaptic competition, cells cannot develop direction selectivity in response to training with bidirectional stimulation, as cells in ferret visual cortex do. We show that imposing a maximum lateral geniculate nucleus (LGN)-to-cortex synaptic weight allows neurons to develop direction-selective responses that maintain the requirement for joint spatial and temporal activation. We demonstrate that a novel form of inhibitory plasticity, postsynaptic activity-dependent long-term potentiation of inhibition (POSD-LTPi), which operates in the developing cortex at the time of eye opening, can provide synaptic competition and enables robust development of direction-selective receptive fields with unidirectional or bidirectional stimulation. We propose a general model of the development of spatiotemporal receptive fields that consists of two phases: an experience-independent establishment of initial biases, followed by an experience-dependent amplification or modification of these biases via correlation-based plasticity of excitatory inputs that compete against gradually increasing feed-forward inhibition. PMID:24598528

Instructional Interactions of Kindergarten Mathematics Classrooms: Validating a Direct Observation Instrument

ERIC Educational Resources Information Center

Doabler, Christian; Smolkowski, Keith; Fien, Hank; Kosty, Derek B.; Cary, Mari Strand

2010-01-01

In this paper, the authors report research focused directly on the validation of the Coding of Academic Teacher-Student interactions (CATS) direct observation instrument. They use classroom information gathered by the CATS instrument to better understand the potential mediating variables hypothesized to influence student achievement. Their study's…

Concordance of chart and billing data with direct observation in dental practice.

PubMed

Demko, Catherine A; Victoroff, Kristin Zakariasen; Wotman, Stephen

2008-10-01

The commonly used methods of chart review, billing data summaries and practitioner self-reporting have not been examined for their ability to validly and reliably represent time use and service delivery in routine dental practice. A more thorough investigation of these data sources would provide insight into the appropriateness of each approach for measuring various clinical behaviors. The aim of this study was to assess the validity of commonly used methods such as dental chart review, billing data, or practitioner self-report compared with a 'gold standard' of information derived from direct observation of routine dental visits. A team of trained dental hygienists directly observed 3751 patient visits in 120 dental practices and recorded the behaviors and procedures performed by dentists and hygienists during patient contact time. Following each visit, charts and billing records were reviewed for the performed and billed procedures. Dental providers characterized their frequency of preventive service delivery through self-administered surveys. We standardized the observation and abstraction methods to obtain optimal measures from each of the multiple data sources. Multi-rater kappa coefficients were computed to monitor standardization, while sensitivity, specificity, and kappa coefficients were calculated to compare the various data sources with direct observation. Chart audits were more sensitive than billing data for all observed procedures and demonstrated higher agreement with directly observed data. Chart and billing records were not sensitive for several prevention-related tasks (oral cancer screening and oral hygiene instruction). Provider self-reports of preventive behaviors were always over-estimated compared with direct observation. Inter-method reliability kappa coefficients for 13 procedures ranged from 0.197 to 0.952. These concordance findings suggest that strengths and weaknesses of data collection sources should be considered when investigating

29. WEST CONFEDERATE AVENUE, OBSERVATION TOWER, IRON BENCH AND DIRECTION ...

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

29. WEST CONFEDERATE AVENUE, OBSERVATION TOWER, IRON BENCH AND DIRECTION FINDER, VIEW ACROSS AGRICULTURAL LANDSCAPE TOWARDS THE "HIGHWATER MARK." VIEW NE. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

Automated Ecological Assessment of Physical Activity: Advancing Direct Observation

PubMed Central

Carlson, Jordan A.; Liu, Bo; Sallis, James F.; Kerr, Jacqueline; Papa, Amy; Dean, Kelsey; Vasconcelos, Nuno M.

2017-01-01

Technological advances provide opportunities for automating direct observations of physical activity, which allow for continuous monitoring and feedback. This pilot study evaluated the initial validity of computer vision algorithms for ecological assessment of physical activity. The sample comprised 6630 seconds per camera (three cameras in total) of video capturing up to nine participants engaged in sitting, standing, walking, and jogging in an open outdoor space while wearing accelerometers. Computer vision algorithms were developed to assess the number and proportion of people in sedentary, light, moderate, and vigorous activity, and group-based metabolic equivalents of tasks (MET)-minutes. Means and standard deviations (SD) of bias/difference values, and intraclass correlation coefficients (ICC) assessed the criterion validity compared to accelerometry separately for each camera. The number and proportion of participants sedentary and in moderate-to-vigorous physical activity (MVPA) had small biases (within 20% of the criterion mean) and the ICCs were excellent (0.82–0.98). Total MET-minutes were slightly underestimated by 9.3–17.1% and the ICCs were good (0.68–0.79). The standard deviations of the bias estimates were moderate-to-large relative to the means. The computer vision algorithms appeared to have acceptable sample-level validity (i.e., across a sample of time intervals) and are promising for automated ecological assessment of activity in open outdoor settings, but further development and testing is needed before such tools can be used in a diverse range of settings. PMID:29194358

Automated Ecological Assessment of Physical Activity: Advancing Direct Observation.

PubMed

Carlson, Jordan A; Liu, Bo; Sallis, James F; Kerr, Jacqueline; Hipp, J Aaron; Staggs, Vincent S; Papa, Amy; Dean, Kelsey; Vasconcelos, Nuno M

2017-12-01

Technological advances provide opportunities for automating direct observations of physical activity, which allow for continuous monitoring and feedback. This pilot study evaluated the initial validity of computer vision algorithms for ecological assessment of physical activity. The sample comprised 6630 seconds per camera (three cameras in total) of video capturing up to nine participants engaged in sitting, standing, walking, and jogging in an open outdoor space while wearing accelerometers. Computer vision algorithms were developed to assess the number and proportion of people in sedentary, light, moderate, and vigorous activity, and group-based metabolic equivalents of tasks (MET)-minutes. Means and standard deviations (SD) of bias/difference values, and intraclass correlation coefficients (ICC) assessed the criterion validity compared to accelerometry separately for each camera. The number and proportion of participants sedentary and in moderate-to-vigorous physical activity (MVPA) had small biases (within 20% of the criterion mean) and the ICCs were excellent (0.82-0.98). Total MET-minutes were slightly underestimated by 9.3-17.1% and the ICCs were good (0.68-0.79). The standard deviations of the bias estimates were moderate-to-large relative to the means. The computer vision algorithms appeared to have acceptable sample-level validity (i.e., across a sample of time intervals) and are promising for automated ecological assessment of activity in open outdoor settings, but further development and testing is needed before such tools can be used in a diverse range of settings.

Observer-based consensus of networked thrust-propelled vehicles with directed graphs.

PubMed

Cang, Weiye; Li, Zhongkui; Wang, Hanlei

2017-11-01

In this paper, we investigate the consensus problem for networked underactuated thrust-propelled vehicles (TPVs) interacting on directed graphs. We propose distributed observer-based consensus protocols, which avoid the reliance on the measurements of translational velocities and accelerations. Using the input-output analysis, we present necessary and sufficient conditions to ensure that the observer-based protocols can achieve consensus for both the cases without and with constant communication delays, provided that the communication graph contains a directed spanning tree. Simulation examples are finally provided to illustrate the effectiveness of the control schemes. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Direct Observation of Teacher and Student Behavior in School Settings: Trends, Issues and Future Directions

ERIC Educational Resources Information Center

Lewis, Timothy J.; Scott, Terrance M.; Wehby, Joseph H.; Wills, Howard P.

2014-01-01

Across the modern history of the field of special education and emotional/behavioral disorders (EBD), direct observation of student and educator behavior has been an essential component of the diagnostic process, student progress monitoring, and establishing functional and statistical relationships within research. This article provides an…

Direct microscopic observation of forward osmosis membrane fouling.

PubMed

Wang, Yining; Wicaksana, Filicia; Tang, Chuyang Y; Fane, Anthony G

2010-09-15

This study describes the application of a noninvasive direct microscopic observation method for characterizing fouling of a forward osmosis (FO) membrane. The effect of the draw solution concentration, membrane orientation, and feed spacer on FO fouling was systematically investigated in a cross-flow setup using latex particles as model foulant in the feedwater. Higher draw solution (DS) concentrations (and thus increased flux levels) resulted in dramatic increase in the surface coverage by latex particles, suggesting that the critical flux concept might be applicable even for the osmotically driven FO process. Under identical draw solution concentrations, the active-layer-facing-the-feed-solution orientation (AL-FS) experienced significantly less fouling compared to the alternative orientation. This may be explained by the lower water flux in AL-FS, which is consistent with the critical flux concept. The use of a feed spacer not only dramatically enhanced the initial flux of the FO membrane, but also significantly improved the flux stability during FO fouling. Despite such beneficial effects of using the feed spacer, a significant amount of particle accumulation was found near the spacer filament, suggesting further opportunities for improved spacer design. To the best of the authors' knowledge, this is the first direct microscopic observation study on FO fouling.

Quantifying the Hawthorne Effect in Hand Hygiene Compliance Through Comparing Direct Observation With Automated Hand Hygiene Monitoring.

PubMed

Hagel, Stefan; Reischke, Jana; Kesselmeier, Miriam; Winning, Johannes; Gastmeier, Petra; Brunkhorst, Frank M; Scherag, André; Pletz, Mathias W

2015-08-01

To quantify the Hawthorne effect of hand hygiene performance among healthcare workers using direct observation. Prospective observational study. Intensive care unit, university hospital. Direct observation of hand hygiene compliance over 48 audits of 2 hours each. Simultaneously, hand hygiene events (HHEs) were recorded using electronic alcohol-based handrub dispensers. Directly observed and electronically recorded HHEs during the 2 hours of direct observation were compared using Spearman correlations and Bland-Altman plots. To quantify the Hawthorne effect, we compared the number of electronically recorded HHEs during the direct observation periods with the re-scaled electronically recorded HHEs in the 6 remaining hours of the 8-hour working shift. A total of 3,978 opportunities for hand hygiene were observed during the 96 hours of direct observation. Hand hygiene compliance was 51% (95% CI, 49%-53%). There was a strong positive correlation between directly observed compliance and electronically recorded HHEs (ρ=0.68 [95% CI, 0.49-0.81], P<.0001). In the 384 hours under surveillance, 4,180 HHEs were recorded by the electronic dispensers. Of those, 2,029 HHEs were recorded during the 96 hours in which direct observation was also performed, and 2,151 HHEs were performed in the remaining 288 hours of the same working shift that were not under direct observation. Healthcare workers performed 8 HHEs per hour when not under observation compared with 21 HHEs per hour during observation. Directly and electronically observed HHEs were in agreement. We observed a marked influence of the Hawthorne effect on hand hygiene performance.

Controllability and observability analysis for vertex domination centrality in directed networks

NASA Astrophysics Data System (ADS)

Wang, Bingbo; Gao, Lin; Gao, Yong; Deng, Yue; Wang, Yu

2014-06-01

Topological centrality is a significant measure for characterising the relative importance of a node in a complex network. For directed networks that model dynamic processes, however, it is of more practical importance to quantify a vertex's ability to dominate (control or observe) the state of other vertices. In this paper, based on the determination of controllable and observable subspaces under the global minimum-cost condition, we introduce a novel direction-specific index, domination centrality, to assess the intervention capabilities of vertices in a directed network. Statistical studies demonstrate that the domination centrality is, to a great extent, encoded by the underlying network's degree distribution and that most network positions through which one can intervene in a system are vertices with high domination centrality rather than network hubs. To analyse the interaction and functional dependence between vertices when they are used to dominate a network, we define the domination similarity and detect significant functional modules in glossary and metabolic networks through clustering analysis. The experimental results provide strong evidence that our indices are effective and practical in accurately depicting the structure of directed networks.

Direct observation of the skyrmion Hall effect

DOE PAGES

Jiang, Wanjun; Zhang, Xichao; Yu, Guoqiang; ...

2016-09-19

The well-known Hall effect describes the transverse deflection of charged particles (electrons/holes) as a result of the Lorentz force. Similarly, it is intriguing to examine if quasi-particles without an electric charge, but with a topological charge, show related transverse motion. Magnetic skyrmions with a well-defined spin texture with a unit topological charge serve as good candidates to test this hypothesis. In spite of the recent progress made on investigating magnetic skyrmions, direct observation of the skyrmion Hall effect has remained elusive. Here, by using a current-induced spin Hall spin torque, we experimentally demonstrate the skyrmion Hall effect, and the resultantmore » skyrmion accumulation, by driving skyrmions from the creep-motion regime (where their dynamics are influenced by pinning defects) into the steady-flow-motion regime. Lastly, the experimental observation of transverse transport of skyrmions due to topological charge may potentially create many exciting opportunities, such as topological selection.« less

Direct observation of the skyrmion Hall effect

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

Jiang, Wanjun; Zhang, Xichao; Yu, Guoqiang

The well-known Hall effect describes the transverse deflection of charged particles (electrons/holes) as a result of the Lorentz force. Similarly, it is intriguing to examine if quasi-particles without an electric charge, but with a topological charge, show related transverse motion. Magnetic skyrmions with a well-defined spin texture with a unit topological charge serve as good candidates to test this hypothesis. In spite of the recent progress made on investigating magnetic skyrmions, direct observation of the skyrmion Hall effect has remained elusive. Here, by using a current-induced spin Hall spin torque, we experimentally demonstrate the skyrmion Hall effect, and the resultantmore » skyrmion accumulation, by driving skyrmions from the creep-motion regime (where their dynamics are influenced by pinning defects) into the steady-flow-motion regime. Lastly, the experimental observation of transverse transport of skyrmions due to topological charge may potentially create many exciting opportunities, such as topological selection.« less

Directed evolution of multiple genomic loci allows the prediction of antibiotic resistance.

PubMed

Nyerges, Ákos; Csörgő, Bálint; Draskovits, Gábor; Kintses, Bálint; Szili, Petra; Ferenc, Györgyi; Révész, Tamás; Ari, Eszter; Nagy, István; Bálint, Balázs; Vásárhelyi, Bálint Márk; Bihari, Péter; Számel, Mónika; Balogh, Dávid; Papp, Henrietta; Kalapis, Dorottya; Papp, Balázs; Pál, Csaba

2018-06-19

Antibiotic development is frequently plagued by the rapid emergence of drug resistance. However, assessing the risk of resistance development in the preclinical stage is difficult. Standard laboratory evolution approaches explore only a small fraction of the sequence space and fail to identify exceedingly rare resistance mutations and combinations thereof. Therefore, new rapid and exhaustive methods are needed to accurately assess the potential of resistance evolution and uncover the underlying mutational mechanisms. Here, we introduce directed evolution with random genomic mutations (DIvERGE), a method that allows an up to million-fold increase in mutation rate along the full lengths of multiple predefined loci in a range of bacterial species. In a single day, DIvERGE generated specific mutation combinations, yielding clinically significant resistance against trimethoprim and ciprofloxacin. Many of these mutations have remained previously undetected or provide resistance in a species-specific manner. These results indicate pathogen-specific resistance mechanisms and the necessity of future narrow-spectrum antibacterial treatments. In contrast to prior claims, we detected the rapid emergence of resistance against gepotidacin, a novel antibiotic currently in clinical trials. Based on these properties, DIvERGE could be applicable to identify less resistance-prone antibiotics at an early stage of drug development. Finally, we discuss potential future applications of DIvERGE in synthetic and evolutionary biology. Copyright © 2018 the Author(s). Published by PNAS.

Direct observation of safety belt use in Michigan : Fall 1997

DOT National Transportation Integrated Search

1997-10-01

The present survey reports the results of a direct observation survey of safety belt use conducted in the fall of 1997. In this study, 10,307 occupants traveling in four vehicle types (oassenger cars, sport-utility vehicles, vans, and pickup trucks) ...

Direct observation of safety belt use in Michigan : Fall 2000

DOT National Transportation Integrated Search

2000-11-01

Reported here are the results of a direct observation survey of safety belt use conducted in the fall of 2000. In this study, 14,366 occupants traveling in four vehicle types (passenger cars, sport-utility vehicles, vans/minivans, and pickup trucks) ...

Observations of a bi-directional lightning leader producing an M-component

NASA Astrophysics Data System (ADS)

Kotovsky, D. A.; Uman, M. A.; Wilkes, R.; Carvalho, F. L.; Jordan, D. M.

2017-12-01

Lightning discharges to ground often exhibit millisecond-scale surges in the continuing currents following return strokes, called M-components. Relatively little is known regarding the source of M-component charge and the mechanisms by which that charge is transferred to ground. In this work, we seek to directly address these questions by presenting correlated high-speed video and Lightning Mapping Array (LMA) observations of a bi-directional leader that resulted in an M-component occurring in a rocket-and-wire triggered lightning flash. The observed leader initiated in the decayed remnants of a positive leader channel that had traversed virgin air approximately 90 msec prior. Three-dimensional locations and speeds of the photographed bi-directional leader and M-component processes are calculated by mapping video images to the observed LMA channel geometry. Both ends of the bi-directional leader exhibited speeds on the order of 2 x106 m sec-1 over 570 meters of the visible channel. Propagation of the luminosity wave from the in-cloud leader to ground ( 8.8 km channel length) exhibited appreciable dispersion, with rise-times (10-90%) increasing from 330 to 410 μsec and pulse-widths (half-maximum) increasing from 380 to 810 μsec - the M-component current pulse measured at ground-level exhibited a rise-time of 290 μsec and a pulse-width of 770 μsec. Group velocities of the luminosity wave have been calculated as a function of frequency, increasing from 2 x107 to 6 x107 m sec-1 over the dominant signal bandwidth (DC to 2 kHz). Additionally, multiple waves of luminosity are observed within the in-cloud channel, indicating nuanced wave phenomena possibly associated with reflection from the end of the leader channel and attachment with the main lightning channel carrying continuing current to ground.

Controllability and observability analysis for vertex domination centrality in directed networks

PubMed Central

Wang, Bingbo; Gao, Lin; Gao, Yong; Deng, Yue; Wang, Yu

2014-01-01

Topological centrality is a significant measure for characterising the relative importance of a node in a complex network. For directed networks that model dynamic processes, however, it is of more practical importance to quantify a vertex's ability to dominate (control or observe) the state of other vertices. In this paper, based on the determination of controllable and observable subspaces under the global minimum-cost condition, we introduce a novel direction-specific index, domination centrality, to assess the intervention capabilities of vertices in a directed network. Statistical studies demonstrate that the domination centrality is, to a great extent, encoded by the underlying network's degree distribution and that most network positions through which one can intervene in a system are vertices with high domination centrality rather than network hubs. To analyse the interaction and functional dependence between vertices when they are used to dominate a network, we define the domination similarity and detect significant functional modules in glossary and metabolic networks through clustering analysis. The experimental results provide strong evidence that our indices are effective and practical in accurately depicting the structure of directed networks. PMID:24954137

Direct observation of safety belt use in Michigan : Fall 1998

DOT National Transportation Integrated Search

1998-10-01

Reported here are the results of a direct observation survey of safety belt use conducted in the fall of 1998. In this study, 11,413 occupants traveling in four vehicle types (passenger cars, sport utility vehicles, vans/minvans, and pickup trucks) w...

Direct observation of safety belt use in Michigan : Fall 1999

DOT National Transportation Integrated Search

1999-01-01

Reported here are the results of a direct observation survey of safety belt use conducted in the fall of 1999. In this study, 9,414 occupants traveling in four vehicle types (passenger cars, sport-utility vehicles, vans/minivans, and pickup trucks) w...

Cosmic curvature tested directly from observations

NASA Astrophysics Data System (ADS)

Denissenya, Mikhail; Linder, Eric V.; Shafieloo, Arman

2018-03-01

Cosmic spatial curvature is a fundamental geometric quantity of the Universe. We investigate a model independent, geometric approach to measure spatial curvature directly from observations, without any derivatives of data. This employs strong lensing time delays and supernova distance measurements to measure the curvature itself, rather than just testing consistency with flatness. We define two curvature estimators, with differing error propagation characteristics, that can crosscheck each other, and also show how they can be used to map the curvature in redshift slices, to test constancy of curvature as required by the Robertson-Walker metric. Simulating realizations of redshift distributions and distance measurements of lenses and sources, we estimate uncertainties on the curvature enabled by next generation measurements. The results indicate that the model independent methods, using only geometry without assuming forms for the energy density constituents, can determine the curvature at the ~6×10‑3 level.

Assessment of Interobserver Reliability in Nutrition Studies that Use Direct Observation of School Meals

PubMed Central

BAGLIO, MICHELLE L.; BAXTER, SUZANNE DOMEL; GUINN, CAROLINE H.; THOMPSON, WILLIAM O.; SHAFFER, NICOLE M.; FRYE, FRANCESCA H. A.

2005-01-01

This article (a) provides a general review of interobserver reliability (IOR) and (b) describes our method for assessing IOR for items and amounts consumed during school meals for a series of studies regarding the accuracy of fourth-grade children's dietary recalls validated with direct observation of school meals. A widely used validation method for dietary assessment is direct observation of meals. Although many studies utilize several people to conduct direct observations, few published studies indicate whether IOR was assessed. Assessment of IOR is necessary to determine that the information collected does not depend on who conducted the observation. Two strengths of our method for assessing IOR are that IOR was assessed regularly throughout the data collection period and that IOR was assessed for foods at the item and amount level instead of at the nutrient level. Adequate agreement among observers is essential to the reasoning behind using observation as a validation tool. Readers are encouraged to question the results of studies that fail to mention and/or to include the results for assessment of IOR when multiple people have conducted observations. PMID:15354155

Modelling 1-minute directional observations of the global irradiance.

NASA Astrophysics Data System (ADS)

Thejll, Peter; Pagh Nielsen, Kristian; Andersen, Elsa; Furbo, Simon

2016-04-01

Direct and diffuse irradiances from the sky has been collected at 1-minute intervals for about a year from the experimental station at the Technical University of Denmark for the IEA project "Solar Resource Assessment and Forecasting". These data were gathered by pyrheliometers tracking the Sun, as well as with apertured pyranometers gathering 1/8th and 1/16th of the light from the sky in 45 degree azimuthal ranges pointed around the compass. The data are gathered in order to develop detailed models of the potentially available solar energy and its variations at high temporal resolution in order to gain a more detailed understanding of the solar resource. This is important for a better understanding of the sub-grid scale cloud variation that cannot be resolved with climate and weather models. It is also important for optimizing the operation of active solar energy systems such as photovoltaic plants and thermal solar collector arrays, and for passive solar energy and lighting to buildings. We present regression-based modelling of the observed data, and focus, here, on the statistical properties of the model fits. Using models based on the one hand on what is found in the literature and on physical expectations, and on the other hand on purely statistical models, we find solutions that can explain up to 90% of the variance in global radiation. The models leaning on physical insights include terms for the direct solar radiation, a term for the circum-solar radiation, a diffuse term and a term for the horizon brightening/darkening. The purely statistical model is found using data- and formula-validation approaches picking model expressions from a general catalogue of possible formulae. The method allows nesting of expressions, and the results found are dependent on and heavily constrained by the cross-validation carried out on statistically independent testing and training data-sets. Slightly better fits -- in terms of variance explained -- is found using the purely

Direct observation of small cluster mobility and ripening

NASA Technical Reports Server (NTRS)

Heinemann, K.; Poppa, H.

1976-01-01

Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single-crystalline thin graphite substrates have been studied by in situ transmission electron microscopy (TEM) under controlled environmental conditions in the temperature range from 25 to 450 C. It was possible to monitor all stages of the experiments by TEM observation of the same specimen area. Slow Ostwald ripening was found to occur over the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility. This was concluded from in situ observations of individual particles during annealing and from measurements of cluster size distributions, cluster number densities, area coverages, and mean cluster diameters.

Three-Item Direct Observation Screen (TIDOS) for Autism Spectrum Disorder

ERIC Educational Resources Information Center

Oner, Pinar; Oner, Ozgur; Munir, Kerim

2014-01-01

We compared ratings on the Three-Item Direct Observation Screen test for autism spectrum disorders completed by pediatric residents with the Social Communication Questionnaire parent reports as an augmentative tool for improving autism spectrum disorder screening performance. We examined three groups of children (18-60 months) comparable in age…

DNA nanomechanics allows direct digital detection of complementary DNA and microRNA targets.

PubMed

Husale, Sudhir; Persson, Henrik H J; Sahin, Ozgur

2009-12-24

Techniques to detect and quantify DNA and RNA molecules in biological samples have had a central role in genomics research. Over the past decade, several techniques have been developed to improve detection performance and reduce the cost of genetic analysis. In particular, significant advances in label-free methods have been reported. Yet detection of DNA molecules at concentrations below the femtomolar level requires amplified detection schemes. Here we report a unique nanomechanical response of hybridized DNA and RNA molecules that serves as an intrinsic molecular label. Nanomechanical measurements on a microarray surface have sufficient background signal rejection to allow direct detection and counting of hybridized molecules. The digital response of the sensor provides a large dynamic range that is critical for gene expression profiling. We have measured differential expressions of microRNAs in tumour samples; such measurements have been shown to help discriminate between the tissue origins of metastatic tumours. Two hundred picograms of total RNA is found to be sufficient for this analysis. In addition, the limit of detection in pure samples is found to be one attomolar. These results suggest that nanomechanical read-out of microarrays promises attomolar-level sensitivity and large dynamic range for the analysis of gene expression, while eliminating biochemical manipulations, amplification and labelling.

Directly observable optical properties of sprites in Central Europe

NASA Astrophysics Data System (ADS)

Bór, József

2013-04-01

Luminous optical emissions accompanying streamer-based natural electric breakdown processes initiating in the mesosphere are called sprites. 489 sprite events have been observed with a TV frame rate video system in Central Europe from Sopron (47.68N, 16.58E, 230 m MSL), Hungary between 2007 and 2009. On the basis of these observations, characteristic morphological properties of sprites, i.e. basic forms (e.g. column, carrot, angel, etc.) as well as common morphological features (e.g. tendrils, glows, puffs, beads, etc.), have been identified. Probable time sequences of streamer propagation directions were associated with each of the basic sprite forms. It is speculated that different sequences of streamer propagation directions can result in very similar final sprite shapes. The number and type variety of sprite elements appearing in an event as well as the total optical duration of an event was analyzed statistically. Jellyfish and dancing sprite events were considered as special subsets of sprite clusters. It was found that more than 90% of the recorded sprite elements appeared in clusters rather than alone and more than half of the clusters contained more than one basic sprite forms. The analysis showed that jellyfish sprites and clusters of column sprites featuring glows and tendrils do not tend to have optical lifetimes longer than 80 ms. Such very long optical lifetimes have not been observed in sprite clusters containing more than 25 elements of any type, either. In contrast to clusters containing sprite entities of only one form, sprite events showing more sprite forms seem to have extended optical durations more likely. The need for further investigation and for finding theoretical concepts to link these observations to electric conditions ambient for sprite formation is emphasized.

Responses to the advanced notice of proposed rulemaking EPA published on June 6, 1996 regarding changes to the EPA allowance auctions and elimination of the direct sale

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

Critchfield, L.R.

1997-12-31

On June 6, 1996, EPA`s Acid Rain Program published an advance notice of proposed rulemaking (ANPRM) in the Federal Register seeking comment on: (1) whether to change the design of the annual sulfur dioxide (SO{sub 2}) allowance auctions; (2) whether to change the timing of the allowance auctions; (3) whether to change the requirement that the minimum price of offered allowances must be in whole dollars, and (4) whether EPA should propose the ability to submit allowance transfers electronically. EPA also published on that day a proposed and direct final rule on whether to eliminate the direct sale. This papermore » documents the issues addressed in the ANPRM, the comments EPA received, and EPA`s responses to those comments. EPA received comments from 14 separate commenters.« less

Analysis of multidimensional difference-of-Gaussians filters in terms of directly observable parameters.

PubMed

Cope, Davis; Blakeslee, Barbara; McCourt, Mark E

2013-05-01

The difference-of-Gaussians (DOG) filter is a widely used model for the receptive field of neurons in the retina and lateral geniculate nucleus (LGN) and is a potential model in general for responses modulated by an excitatory center with an inhibitory surrounding region. A DOG filter is defined by three standard parameters: the center and surround sigmas (which define the variance of the radially symmetric Gaussians) and the balance (which defines the linear combination of the two Gaussians). These parameters are not directly observable and are typically determined by nonlinear parameter estimation methods applied to the frequency response function. DOG filters show both low-pass (optimal response at zero frequency) and bandpass (optimal response at a nonzero frequency) behavior. This paper reformulates the DOG filter in terms of a directly observable parameter, the zero-crossing radius, and two new (but not directly observable) parameters. In the two-dimensional parameter space, the exact region corresponding to bandpass behavior is determined. A detailed description of the frequency response characteristics of the DOG filter is obtained. It is also found that the directly observable optimal frequency and optimal gain (the ratio of the response at optimal frequency to the response at zero frequency) provide an alternate coordinate system for the bandpass region. Altogether, the DOG filter and its three standard implicit parameters can be determined by three directly observable values. The two-dimensional bandpass region is a potential tool for the analysis of populations of DOG filters (for example, populations of neurons in the retina or LGN), because the clustering of points in this parameter space may indicate an underlying organizational principle. This paper concentrates on circular Gaussians, but the results generalize to multidimensional radially symmetric Gaussians and are given as an appendix.

Observations of the directional distribution of the wind energy input function over swell waves

NASA Astrophysics Data System (ADS)

Shabani, Behnam; Babanin, Alex V.; Baldock, Tom E.

2016-02-01

Field measurements of wind stress over shallow water swell traveling in different directions relative to the wind are presented. The directional distribution of the measured stresses is used to confirm the previously proposed but unverified directional distribution of the wind energy input function. The observed wind energy input function is found to follow a much narrower distribution (β∝cos⁡3.6θ) than the Plant (1982) cosine distribution. The observation of negative stress angles at large wind-wave angles, however, indicates that the onset of negative wind shearing occurs at about θ≈ 50°, and supports the use of the Snyder et al. (1981) directional distribution. Taking into account the reverse momentum transfer from swell to the wind, Snyder's proposed parameterization is found to perform exceptionally well in explaining the observed narrow directional distribution of the wind energy input function, and predicting the wind drag coefficients. The empirical coefficient (ɛ) in Snyder's parameterization is hypothesised to be a function of the wave shape parameter, with ɛ value increasing as the wave shape changes between sinusoidal, sawtooth, and sharp-crested shoaling waves.

Feasibility of tuberculosis treatment monitoring by video directly observed therapy: a binational pilot study.

PubMed

Garfein, R S; Collins, K; Muñoz, F; Moser, K; Cerecer-Callu, P; Raab, F; Rios, P; Flick, A; Zúñiga, M L; Cuevas-Mota, J; Liang, K; Rangel, G; Burgos, J L; Rodwell, T C; Patrick, K

2015-09-01

Although directly observed therapy (DOT) is recommended worldwide for monitoring anti-tuberculosis treatment, transportation and personnel requirements limit its use. To evaluate the feasibility and acceptability of 'video DOT' (VDOT), which allows patients to record and transmit medication ingestion via videos watched remotely by health care providers to document adherence. We conducted a single-arm trial among tuberculosis (TB) patients in San Diego, California, USA, (n = 43) and Tijuana, Mexico (n = 9) to represent high- and low-resource settings. Pre-/post-treatment interviews assessed participant characteristics and experiences. Adherence was defined as the proportion of observed doses to expected doses. The mean age was 37 years (range 18-86), 50% were male, and 88% were non-Caucasian. The mean duration of VDOT use was 5.5 months (range 1-11). Adherence was similar in San Diego (93%) and Tijuana (96%). Compared to time on in-person DOT, 92% preferred VDOT, 81% thought VDOT was more confidential, 89% never/rarely had problems recording videos, and 100% would recommend VDOT to others. Seven (13%) participants were returned to in-person DOT and six (12%) additional participants had their phones lost, broken or stolen. VDOT was feasible and acceptable, with high adherence in both high- and low-resource settings. Efficacy and cost-effectiveness studies are needed.

Establishing the feasibility of direct observation in the assessment of tics in children with chronic tic disorders.

PubMed

Himle, Michael B; Chang, Susanna; Woods, Douglas W; Pearlman, Amanda; Buzzella, Brian; Bunaciu, Liviu; Piacentini, John C

2006-01-01

Behavior analysis has been at the forefront in establishing effective treatments for children and adults with chronic tic disorders. As is customary in behavior analysis, the efficacy of these treatments has been established using direct-observation assessment methods. Although behavior-analytic treatments have enjoyed acceptance and integration into mainstream health care practices for tic disorders (e.g., psychiatry and neurology), the use of direct observation as a primary assessment tool has been neglected in favor of less objective methods. Hesitation to use direct observation appears to stem largely from concerns about the generalizability of clinic observations to other settings (e.g., home) and a lack of consensus regarding the most appropriate and feasible techniques for conducting and scoring direct observation. The purpose of the current study was to evaluate and establish a reliable, valid, and feasible direct-observation protocol capable of being transported to research and clinical settings. A total of 43 children with tic disorders, collected from two outpatient specialty clinics, were assessed using direct (videotape samples) and indirect (Yale Global Tic Severity Scale; YGTSS) methods. Videotaped observation samples were collected across 3 consecutive weeks and two different settings (clinic and home), were scored using both exact frequency counts and partial-interval coding, and were compared to data from a common indirect measure of tic severity (the YGTSS). In addition, various lengths of videotaped segments were scored to determine the optimal observation length. Results show that (a) clinic-based observations correspond well to home-based observations, (b) brief direct-observation segments scored with time-sampling methods reliably quantified tics, and (c) indirect methods did not consistently correspond with the direct methods.

Directing visual attention during action observation modulates corticospinal excitability

PubMed Central

Wood, Greg; Franklin, Zoe C.; Marshall, Ben; Riach, Martin; Holmes, Paul S.

2018-01-01

Transcranial magnetic stimulation (TMS) research has shown that corticospinal excitability is facilitated during the observation of human movement. However, the relationship between corticospinal excitability and participants’ visual attention during action observation is rarely considered. Nineteen participants took part in four conditions: (i) a static hand condition, involving observation of a right hand holding a ball between the thumb and index finger; (ii) a free observation condition, involving observation of the ball being pinched between thumb and index finger; and (iii and iv) finger-focused and ball-focused conditions, involving observation of the same ball pinch action with instructions to focus visual attention on either the index finger or the ball. Single-pulse TMS was delivered to the left motor cortex and motor evoked potentials (MEPs) were recorded from the first dorsal interosseous (FDI) and abductor digiti minimi muscles of the right hand. Eye movements were recorded simultaneously throughout each condition. The ball-focused condition produced MEPs of significantly larger amplitude in the FDI muscle, compared to the free observation or static hand conditions. Furthermore, regression analysis indicated that the number of fixations on the ball was a significant predictor of MEP amplitude in the ball-focused condition. These results have important implications for the design and delivery of action observation interventions in motor (re)learning settings. Specifically, providing viewing instructions that direct participants to focus visual attention on task-relevant objects affected by the observed movement promotes activity in the motor system in a more optimal manner than free observation or no instructions. PMID:29304044

Home Videophones Improve Direct Observation in Tuberculosis Treatment: A Mixed Methods Evaluation

PubMed Central

Wade, Victoria A.; Karnon, Jonathan; Eliott, Jaklin A.; Hiller, Janet E.

2012-01-01

Background The use of direct observation to monitor tuberculosis treatment is controversial: cost, practical difficulties, and lack of patient acceptability limit effectiveness. Telehealth is a promising alternative delivery method for improving implementation. This study aimed to evaluate the clinical and cost-effectiveness of a telehealth service delivering direct observation, compared to an in-person drive-around service. Methodology/Principal Findings The study was conducted within a community nursing service in South Australia. Telehealth patients received daily video calls at home on a desktop videophone provided by the nursing call center. A retrospective cohort study assessed the effectiveness of the telehealth and traditional forms of observation, defined by the proportion of missed observations recorded in case notes. This data was inputted to a model, estimating the incremental cost-effectiveness ratio (ICER) of telehealth. Semi-structured interviews were conducted with current patients, community nursing and Chest Clinic staff, concerning service acceptability, usability and sustainability. The percentage of missed observations for the telehealth service was 12.1 (n = 58), compared to 31.1 for the in-person service (n = 70). Most of the difference of 18.9% (95% CI: 12.2 – 25.4) was due to fewer pre-arranged absences. The economic analysis calculated the ICER to be AUD$1.32 (95% CI: $0.51 – $2.26) per extra day of successful observation. The video service used less staff time, and became dominant if implemented on a larger scale and/or with decreased technology costs. Qualitative analysis found enabling factors of flexible timing, high patient acceptance, staff efficiency, and Chest Clinic support. Substantial technical problems were manageable, and improved liaison between the nursing service and Chest Clinic was an unexpected side-benefit. Conclusions/Significance Home video observation is a patient-centered, resource efficient way of

Direct observation of a photochemical activation energy: a case study of acetone photodissociation

NASA Astrophysics Data System (ADS)

Koch, Markus; Heim, Pascal; Thaler, Bernhard; Kitzler, Markus; Ernst, Wolfgang E.

2017-06-01

The ability to observe and quantify the conversion of electronic potential energy to vibrational kinetic energy in a molecule after photoexcitation is essential to understand and control the outcome of photoinduced molecular fragmentation. We exploit the high selectivity of photoelectron-photoion coincidence detection to distinguish different relaxation channels and observe the fragmentation behavior of each channel. We demonstrate the concept by investigating the fragmentation of gas-phase acetone molecules initiated by three-photon excitation to high lying Rydberg states between 9.0 and 9.5 eV above the ground state. By applying variations of the photon energy, pulse duration (100-200 fs) and pulse energy, we are able to fully characterize the fragmentation process. Rydberg states between 5s and 8s are populated, which undergo ultrafast internal conversion to lower states. The corresponding non-adiabatic dynamics in the neutral molecule cause the conversion of electronic to vibrational energy, leading to fragmentation. Our scheme allows us to directly measure the activation energy for fragmentation of acetone to an acetyl ion and a methyl radical, which we determine to be (0.79 ± 0.04) eV. Longer laser pulses result in an increased fragment-to-parent ratio, representing a higher probability for relaxation because the relaxation time constants are comparable to the pulse duration. Upon excitation to Rydberg states at 9.5 eV we surprisingly observe reduced fragmentation, although ˜2 eV are coupled into vibrational energy, indicating that different relaxation pathways become active, which results in a change of the redistribution of vibrational energy within the molecule. Fragmentation due to subsequent excitation of the cation is found to play a minor role.

'Sometimes the work just needs to be done': socio-cultural influences on direct observation in medical training.

PubMed

Watling, Christopher; LaDonna, Kori A; Lingard, Lorelei; Voyer, Stephane; Hatala, Rose

2016-10-01

Direct observation promises to strengthen both coaching and assessment, and calls for its increased use in medical training abound. Despite its apparent potential, the uptake of direct observation in medical training remains surprisingly limited outside the formal assessment setting. The limited uptake of observation raises questions about cultural barriers to its use. In this study, we explore the influence of professional culture on the use of direct observation within medical training. Using a constructivist grounded theory approach, we interviewed 22 residents or fellows (10 male, 12 female) about their experiences of being observed during training. Participants represented a range of specialties and training levels. Data collection and analysis were conducted iteratively. Themes were identified using constant comparative analysis. Observation was used selectively; specialties tended to observe the clinical acts that they valued most. Despite these differences, we found two cultural values that consistently challenged the ready implementation of direct observation across specialties: (i) autonomy in learning and (ii) efficiency in health care provision. Furthermore, we found that direct observation was a primarily learner-driven activity, which left learners caught in the middle, wanting observation but also wanting to appear independent and efficient. The cultural values of autonomy in learning and practice and efficiency in health care provision challenge the integration of direct observation into clinical training. Medical learners are often expected to ask for observation, but such requests are socially and culturally fraught, and likely to constrain the wider uptake of direct observation. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Feasibility of Tuberculosis Treatment Monitoring by Video Directly Observed Therapy: A Binational Pilot Study

PubMed Central

Garfein, Richard S.; Collins, Kelly; Muñoz, Fátima; Moser, Kathleen; Cerecer-Callu, Paris; Raab, Fredrick; Rios, Phillip; Flick, Allison; Zúñiga, María Luisa; Cuevas-Mota, Jazmine; Liang, Krystal; Rangel, Gudelia; Burgos, José Luis; Rodwell, Timothy; Patrick, Kevin

2017-01-01

Objective Directly observed therapy is recommended worldwide for monitoring tuberculosis (TB) treatment; yet transportation and personnel requirements limit its use. We evaluated the feasibility and acceptability of “Video DOT” (VDOT), which allowed patients to record and transmit medication ingestion videos that were watched remotely by healthcare providers to document adherence. Methods We conducted a single-arm trial among TB patients in San Diego, CA (n=43) and Tijuana, B.C., Mexico (n=9) to represent high- and low-resources settings. Pre/post treatment interviews assessed participant characteristics and experiences. Adherence was defined as the proportion of observed doses to expected doses. Results Mean age was 34 years (range: 18–86), 54% were male, and 77% were non-Caucasian. Mean duration of VDOT use was 5.5 months (range: 1–11). Adherence was similar in San Diego (93%) and Tijuana (96%). Compared to time on in-person DOT, 92% preferred VDOT; 81% thought VDOT was more confidential; 89% never/rarely had problems recording videos; and 100% would recommend VDOT to others. Overall, 7 (13%) participants were returned to in-person DOT and 6 (12%) separate participants had their phone lost, broken or stolen. Conclusions VDOT was feasible and acceptable with high adherence in high- and low-resource settings. Efficacy and cost-effectiveness studies are needed. PMID:26260824

An Observation Knowledgebase for Hinode Data

NASA Astrophysics Data System (ADS)

Hurlburt, Neal E.; Freeland, S.; Green, S.; Schiff, D.; Seguin, R.; Slater, G.; Cirtain, J.

2007-05-01

We have developed a standards-based system for the Solar Optical and X Ray Telescopes on the Hinode orbiting solar observatory which can serve as part of a developing Heliophysics informatics system. Our goal is to make the scientific data acquired by Hinode more accessible and useful to scientists by allowing them to do reasoning and flexible searches on observation metadata and to ask higher-level questions of the system than previously allowed. The Hinode Observation Knowledgebase relates the intentions and goals of the observation planners (as-planned metadata) with actual observational data (as-run metadata), along with connections to related models, data products and identified features (follow-up metadata) through a citation system. Summaries of the data (both as image thumbnails and short "film strips") serve to guide researchers to the observations appropriate for their research, and these are linked directly to the data catalog for easy extraction and delivery. The semantic information of the observation (Field of view, wavelength, type of observable, average cadence etc.) is captured through simple user interfaces and encoded using the VOEvent XML standard (with the addition of some solar-related extensions). These interfaces merge metadata acquired automatically during both mission planning and an data analysis (see Seguin et. al. 2007 at this meeting) phases with that obtained directly from the planner/analyst and send them to be incorporated into the knowledgebase. The resulting information is automatically rendered into standard categories based on planned and recent observations, as well as by popularity and recommendations by the science team. They are also directly searchable through both and web-based searches and direct calls to the API. Observations details can also be rendered as RSS, iTunes and Google Earth interfaces. The resulting system provides a useful tool to researchers and can act as a demonstration for larger, more complex systems.

Increasing Reliability of Direct Observation Measurement Approaches in Emotional and/or Behavioral Disorders Research Using Generalizability Theory

ERIC Educational Resources Information Center

Gage, Nicholas A.; Prykanowski, Debra; Hirn, Regina

2014-01-01

Reliability of direct observation outcomes ensures the results are consistent, dependable, and trustworthy. Typically, reliability of direct observation measurement approaches is assessed using interobserver agreement (IOA) and the calculation of observer agreement (e.g., percentage of agreement). However, IOA does not address intraobserver…

Warming experiments elucidate the drivers of observed directional changes in tundra vegetation

PubMed Central

Hollister, Robert D; May, Jeremy L; Kremers, Kelseyann S; Tweedie, Craig E; Oberbauer, Steven F; Liebig, Jennifer A; Botting, Timothy F; Barrett, Robert T; Gregory, Jessica L

2015-01-01

Few studies have clearly linked long-term monitoring with in situ experiments to clarify potential drivers of observed change at a given site. This is especially necessary when findings from a site are applied to a much broader geographic area. Here, we document vegetation change at Barrow and Atqasuk, Alaska, occurring naturally and due to experimental warming over nearly two decades. An examination of plant cover, canopy height, and community indices showed more significant differences between years than due to experimental warming. However, changes with warming were more consistent than changes between years and were cumulative in many cases. Most cases of directional change observed in the control plots over time corresponded with a directional change in response to experimental warming. These included increases in canopy height and decreases in lichen cover. Experimental warming resulted in additional increases in evergreen shrub cover and decreases in diversity and bryophyte cover. This study suggests that the directional changes occurring at the sites are primarily due to warming and indicates that further changes are likely in the next two decades if the regional warming trend continues. These findings provide an example of the utility of coupling in situ experiments with long-term monitoring to accurately document vegetation change in response to global change and to identify the underlying mechanisms driving observed changes. PMID:26140204

Attainment of students’ conception in magnetic fields by using of direct observation and symbolic language ability

NASA Astrophysics Data System (ADS)

Desy Fatmaryanti, Siska; Suparmi; Sarwanto; Ashadi

2017-11-01

This study focuses on description attainment of students’ conception in the magnetic field. The conception was based by using of direct observation and symbolic language ability. The method used is descriptive quantitative research. The subject of study was about 86 students from 3 senior high school at Purworejo. The learning process was done by guided inquiry model. During the learning, students were required to actively investigate the concept of a magnetic field around a straight wire electrical current Data retrieval was performed using an instrument in the form of a multiple choice test reasoned and observation during the learning process. There was four indicator of direct observation ability and four indicators of symbolic language ability to grouping category of students conception. The results of average score showed that students conception about the magnitude more better than the direction of magnetic fields in view of symbolic language. From the observation, we found that students could draw the magnetic fields line not from a text book but their direct observation results. They used various way to get a good accuracy of observation results. Explicit recommendations are presented in the discussion section at the end of this paper.

The implementation of a mobile problem-specific electronic CEX for assessing directly observed student-patient encounters.

PubMed

Ferenchick, Gary S; Foreback, Jami; Towfiq, Basim; Kavanaugh, Kevin; Solomon, David; Mohmand, Asad

2010-01-29

Facilitating direct observation of medical students' clinical competencies is a pressing need. We developed an electronic problem-specific Clinical Evaluation Exercise (eCEX) based on a national curriculum. We assessed its feasibility in monitoring and recording students' competencies and the impact of a grading incentive on the frequency of direct observations in an internal medicine clerkship. Students (n = 56) at three clinical sites used the eCEX and comparison students (n = 56) at three other clinical sites did not. Students in the eCEX group were required to arrange 10 evaluations with faculty preceptors. Students in the second group were required to document a single, faculty observed 'Full History and Physical' encounter with a patient. Students and preceptors were surveyed at the end of each rotation. eCEX increased students' and evaluators' understanding of direct-observation objectives and had a positive impact on the evaluators' ability to provide feedback and assessments. The grading incentive increased the number of times a student reported direct observation by a resident preceptor. eCEX appears to be an effective means of enhancing student evaluation.

Direct Observation of Twisted Surface skyrmions in Bulk Crystals

NASA Astrophysics Data System (ADS)

Zhang, S. L.; van der Laan, G.; Wang, W. W.; Haghighirad, A. A.; Hesjedal, T.

2018-06-01

Magnetic skyrmions in noncentrosymmetric helimagnets with Dn symmetry are Bloch-type magnetization swirls with a helicity angle of ±9 0 ° . At the surface of helimagnetic thin films below a critical thickness, a twisted skyrmion state with an arbitrary helicity angle has been proposed; however, its direct experimental observation has remained elusive. Here, we show that circularly polarized resonant elastic x-ray scattering is able to unambiguously measure the helicity angle of surface skyrmions, providing direct experimental evidence that a twisted skyrmion surface state also exists in bulk systems. The exact surface helicity angles of twisted skyrmions for both left- and right-handed chiral bulk Cu2 OSeO3 , in the single as well as in the multidomain skyrmion lattice state, are determined, revealing their detailed internal structure. Our findings suggest that a skyrmion surface reconstruction is a universal phenomenon, stemming from the breaking of translational symmetry at the interface.

Direct Observation of Quantum Coherence in Single-Molecule Magnets

NASA Astrophysics Data System (ADS)

Schlegel, C.; van Slageren, J.; Manoli, M.; Brechin, E. K.; Dressel, M.

2008-10-01

Direct evidence of quantum coherence in a single-molecule magnet in a frozen solution is reported with coherence times as long as T2=630±30ns. We can strongly increase the coherence time by modifying the matrix in which the single-molecule magnets are embedded. The electron spins are coupled to the proton nuclear spins of both the molecule itself and, interestingly, also to those of the solvent. The clear observation of Rabi oscillations indicates that we can manipulate the spin coherently, an essential prerequisite for performing quantum computations.

Prediction of direct band gap silicon superlattices with dipole-allowed optical transition

NASA Astrophysics Data System (ADS)

Kim, Sunghyun; Oh, Young Jun; Lee, In-Ho; Lee, Jooyoung; Chang, K. J.

While cubic diamond silicon (c-Si) is an important element in electronic devices, it has poor optical properties owing to its indirect gap nature, thereby limiting its applications to optoelectronic devices. Here, we report Si superlattice structures which are computationally designed to possess direct band gaps and excellent optical properties. The computational approach adopts density functional calculations and conformational space annealing for global optimization. The Si superlattices, which consist of alternating stacks of Si(111) layers and a defective layer with Seiwatz chains, have either direct or quasi-direct band gaps depending on the details of attacking layers. The photovoltaic efficiencies are calculated by solving Bethe-Salpeter equation together with quasiparticle G0W0 calculations. The strong direct optical transition is attributed to the overlap of the valence and conduction band edge states in the interface region. Our Si superlattices exhibit high thermal stability, with the energies lower by an order of magnitude than those of the previously reported Si allotropes. We discuss a possible route to the synthesis of the superlattices through wafer bonding. This work is supported by Samsung Science and Technology Foundation under Grant No. SSTF-BA1401-08.

Self-administered Versus Directly Observed Once-Weekly Isoniazid and Rifapentine Treatment of Latent Tuberculosis Infection

PubMed Central

Belknap, Robert; Holland, David; Feng, Pei-Jean; Millet, Joan-Pau; Caylà, Joan A.; Martinson, Neil A.; Wright, Alicia; Chen, Michael P.; Moro, Ruth N.; Scott, Nigel A.; Arevalo, Bert; Miró, José M.; Villarino, Margarita E.; Weiner, Marc; Borisov, Andrey S.

2017-01-01

Background Expanding latent tuberculosis treatment is important to decrease active disease globally. Once-weekly isoniazid and rifapentine for 12 doses is effective but limited by requiring direct observation. Objective To compare treatment completion and safety of once-weekly isoniazid and rifapentine by self-administration versus direct observation. Design An open-label, phase 4 randomized clinical trial designed as a noninferiority study with a 15% margin. Seventy-five percent or more of study patients were enrolled from the United States for a prespecified subgroup analysis. (ClinicalTrials.gov: NCT01582711) Setting Outpatient tuberculosis clinics in the United States, Spain, Hong Kong, and South Africa. Participants 1002 adults (aged ≥18 years) recommended for treatment of latent tuberculosis infection. Intervention Participants received once-weekly isoniazid and rifapentine by direct observation, self-administration with monthly monitoring, or self-administration with weekly text message reminders and monthly monitoring. Measurements The primary outcome was treatment completion, defined as 11 or more doses within 16 weeks and measured using clinical documentation and pill counts for direct observation, and self-reports, pill counts, and medication event–monitoring devices for self-administration. The main secondary outcome was adverse events. Results Median age was 36 years, 48% of participants were women, and 77% were enrolled at the U.S. sites. Treatment completion was 87.2% (95% CI, 83.1% to 90.5%) in the direct-observation group, 74.0% (CI, 68.9% to 78.6%) in the self-administration group, and 76.4% (CI, 71.3% to 80.8%) in the self-administration–with–reminders group. In the United States, treatment completion was 85.4% (CI, 80.4% to 89.4%), 77.9% (CI, 72.7% to 82.6%), and 76.7% (CI, 70.9% to 81.7%), respectively. Self-administered therapy without reminders was noninferior to direct observation in the United States; no other comparisons met

Modified directly observed treatment for tuberculosis versus self-administered therapy: an observational study in rural Greece.

PubMed

Charokopos, N; Tsiros, G; Foka, A; Voila, P; Chrysanthopoulos, K; Spiliopoulou, I; Jelastopulu, E

2013-01-01

Directly Observed Treatment (DOT) is the key element of DOTS (directly observed treatment, short course), part of the internationally recommended control strategy for tuberculosis (TB). The evaluation of DOT has not been widely evaluated in rural areas in developed settings. The aim of this pilot study was to evaluate a modified DOT program (MDOT) by a general practitioner (GP) in a rural area of southwest Greece, where there is substantial underreporting of TB cases. Thirteen new TB cases with 30 close contacts were compared with 41 past-treated TB subjects (controls) with 111 close contacts in this observational, case-control study. Home visits by a GP were conducted and comparison of various data (laboratory findings, treatment outcomes, questionnaire-based parameters, on-site recorded conditions) was performed in both newly detected pulmonary TB cases and previously treated TB cases managed without DOT intervention. MDOT by GP implementation revealed that 11 cases (84.6%) were successfully treated, one (7.7%) case died, and one (7.7%) was lost to follow up. None of the close contacts of new TB cases was infected with active TB, while 6.3% of previously-treated TB subjects were infected with active TB and had to receive a complete anti-TB regimen. Chemoprophylaxis was administered to 13.3% of close contacts of new cases; whereas 12.6% of close contacts of previously-treated patients received chemoprophylaxis. This pilot study revealed that a GP is able to implement a program based on DOT resulting in high treatment adherence and prevention of TB compared with the conventional self-administration of treatment.

Feedback in formative OSCEs: comparison between direct observation and video-based formats

PubMed Central

Junod Perron, Noëlle; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

2016-01-01

Introduction Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Results Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational

Feedback in formative OSCEs: comparison between direct observation and video-based formats.

PubMed

Junod Perron, Noëlle; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

2016-01-01

Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p= 0.002 and 3.71 vs. 2.04, p= 0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p= 0.007; active problem-solving: 3.92 vs. 3.42, p= 0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational goal.

Direct observation of fast protein conformational switching.

PubMed

Ishikawa, Haruto; Kwak, Kyungwon; Chung, Jean K; Kim, Seongheun; Fayer, Michael D

2008-06-24

Folded proteins can exist in multiple conformational substates. Each substate reflects a local minimum on the free-energy landscape with a distinct structure. By using ultrafast 2D-IR vibrational echo chemical-exchange spectroscopy, conformational switching between two well defined substates of a myoglobin mutant is observed on the approximately 50-ps time scale. The conformational dynamics are directly measured through the growth of cross peaks in the 2D-IR spectra of CO bound to the heme active site. The conformational switching involves motion of the distal histidine/E helix that changes the location of the imidazole side group of the histidine. The exchange between substates changes the frequency of the CO, which is detected by the time dependence of the 2D-IR vibrational echo spectrum. These results demonstrate that interconversion between protein conformational substates can occur on very fast time scales. The implications for larger structural changes that occur on much longer time scales are discussed.

A comparison of in situ and airborne radar observations of ocean wave directionality

NASA Technical Reports Server (NTRS)

Jackson, F. C.; Walton, W. T.; Peng, C. Y.

1985-01-01

The directional spectrum of a fully arisen, about 3 m sea as measured by an experimental airborne radar, the NASA K(u)-band radar ocean wave spectrometer (ROWS), is compared to reference pitch-roll buoy data and to the classical SWOP (stereo wave observations project) spectrum for fully developed conditions. The ROWS spectrum, inferred indirectly from backscattered power measurements at 5-km altitude, is shown to be in excellent agreement with the buoy spectrum. Specifically, excellent agreement is found between the two nondirectional height spectra, and mean wave directions and directional spreads as functions of frequency. A comparison of the ROWS and SWOP spectra shows the two spectra to be very similar, in detailed shape as well as in terms of the gross spreading characteristics. Both spectra are seen to exhibit bimodal structures which accord with the Phillips' (1958) resonance mechanism. This observation is thus seen to support Phillips' contention that the SWOP modes were indeed resonance modes, not statistical artifacts.

Direct estimation of tidally induced Earth rotation variations observed by VLBI

NASA Astrophysics Data System (ADS)

Englich, S.; Heinkelmann, R.; BOHM, J.; Schuh, H.

2009-09-01

The subject of our study is the investigation of periodical variations induced by solid Earth tides and ocean tides in Earth rotation parameters (ERP: polar motion, UT1)observed by VLBI. There are two strategies to determine the amplitudes and phases of Earth rotation variations from observations of space geodetic techniques. The common way is to derive time series of Earth rotation parameters first and to estimate amplitudes and phases in a second step. Results obtained by this means were shown in previous studies for zonal tidal variations (Englich et al.; 2008a) and variations caused by ocean tides (Englich et al.; 2008b). The alternative method is to estimate the tidal parameters directly within the VLBI data analysis procedure together with other parameters such as station coordinates, tropospheric delays, clocks etc. The purpose of this work was the application of this direct method to a combined VLBI data analysis using the software packages OCCAM (Version 6.1, Gauss-Markov-Model) and DOGSCS (Gerstl et al.; 2001). The theoretical basis and the preparatory steps for the implementation of this approach are presented here.

Direct Observation of Accretion onto a Hypernova's Newly Formed Black Hole

NASA Astrophysics Data System (ADS)

Milisavljevic, Dan

2017-09-01

Models of energetic core-collapse supernovae and long-duration gamma-ray bursts often invoke engine-driven scenarios associated with the formation of compact objects that input energy into the explosion. To date, only indirect evidence of black holes or magnetars formed in these events exists from observations obtained when the explosions are most luminous. Here we request a modest 15 ks Chandra pilot observation of the exceptionally important nearby hypernova SN2002ap to test models that predict X-ray emission associated with its remnant black hole to be detectable after 15 yr of ejecta expansion. Direct observation a newly formed "baby" black hole would be a landmark discovery capable of opening up new ways to investigate fundamental aspects of the core collapse process.

The Hawthorne effect in direct observation research with physicians and patients.

PubMed

Goodwin, Meredith A; Stange, Kurt C; Zyzanski, Stephen J; Crabtree, Benjamin F; Borawski, Elaine A; Flocke, Susan A

2017-12-01

This study examines the degree to which a "Hawthorne effect" alters outpatient-visit content. Trained research nurses directly observed 4454 visits to 138 family physicians. Multiple data sources were used to examine the Hawthorne effect including differences in medical record documentation for observed visits and the prior visit by the same patient, time use during visits on the first versus the second observation day of each physician, and report by the patient, physician, and observer of the effect of observation. Visits on the first versus the second observation day were longer by an average of 1 minute (P < .001); there were time-use differences for 4 of 20 behaviour categories evaluated. No effect of the observer on the interaction was reported by 74% of patients and 55% of physicians. Most of those that reported an affect indicated it was slight. Patients with non-White race, lower-educational level, and poorer health were more likely to report being affected by the observer. In a study that was designed to minimize the Hawthorne effect, the presence of an observer had little effect on most patient-physician visits but appeared to at least slightly effect a subgroup of vulnerable patients. © 2017 John Wiley & Sons, Ltd.

Direct Observation of Spatiotemporal Dynamics of Short Electron Bunches in Storage Rings

NASA Astrophysics Data System (ADS)

Evain, C.; Roussel, E.; Le Parquier, M.; Szwaj, C.; Tordeux, M.-A.; Brubach, J.-B.; Manceron, L.; Roy, P.; Bielawski, S.

2017-02-01

In recent synchrotron radiation facilities, the use of short (picosecond) electron bunches is a powerful method for producing giant pulses of terahertz coherent synchrotron radiation. Here we report on the first direct observation of these pulse shapes with a few picoseconds resolution, and of their dynamics over a long time. We thus confirm in a very direct way the theories predicting an interplay between two physical processes. Below a critical bunch charge, we observe a train of identical THz pulses (a broadband Terahertz comb) stemming from the shortness of the electron bunches. Above this threshold, a large part of the emission is dominated by drifting structures, which appear through spontaneous self-organization. These challenging single-shot THz recordings are made possible by using a recently developed photonic time stretch detector with a high sensitivity. The experiment has been realized at the SOLEIL storage ring.

Direct observation of void evolution during cement hydration

DOE PAGES

Moradian, Masoud; Hu, Qinang; Aboustait, Mohammed; ...

2017-09-28

This study follows the hydration of both portland cement and tricalcium silicate pastes between 30 min and 16 h of hydration. In-situ fast X-ray Computed Tomography (fCT) was used to make direct observations of the air-filled void formation in w/s of 0.40 to 0.70 with a micron resolution. The results show that over the first hour of the acceleration period the volume of air-filled voids reaches a maximum value and then decreases during the acceleration period and stays constant. The void distribution changes from a few coarse voids to a large number of smaller and more uniformly distributed voids. Thismore » behavior is suggested to be controlled by changes in the ionic strength that cause exsolution of dissolved air from the pore solution.« less

Direct observation of void evolution during cement hydration

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

Moradian, Masoud; Hu, Qinang; Aboustait, Mohammed

This study follows the hydration of both portland cement and tricalcium silicate pastes between 30 min and 16 h of hydration. In-situ fast X-ray Computed Tomography (fCT) was used to make direct observations of the air-filled void formation in w/s of 0.40 to 0.70 with a micron resolution. The results show that over the first hour of the acceleration period the volume of air-filled voids reaches a maximum value and then decreases during the acceleration period and stays constant. The void distribution changes from a few coarse voids to a large number of smaller and more uniformly distributed voids. Thismore » behavior is suggested to be controlled by changes in the ionic strength that cause exsolution of dissolved air from the pore solution.« less

Observational Learning of Academic and Social Behaviors during Small-Group Direct Instruction

ERIC Educational Resources Information Center

Ledford, Jennifer R.; Wolery, Mark

2015-01-01

Many studies have shown that small-group direct instruction is effective and efficient for teaching students with and without disabilities, although relatively few studies have been conducted with heterogeneous groups of preschool participants. In addition, previous studies have primarily assessed whether observational learning occurred for…

Anna Freud: the Hampstead War Nurseries and the role of the direct observation of children for psychoanalysis.

PubMed

Midgley, Nick

2007-08-01

The psychoanalytic tradition of direct observation of children has a long history, going back to the early 20th century, when psychoanalysis and the emerging field of 'child studies' came into fruitful contact in Freud's Vienna. As a leading figure in the attempted integration of direct observation with the new psychoanalytic knowledge emerging from the consulting room, Anna Freud played a crucial role in the emergence of this field. But her major contribution to the theory and practice of observing children came during the Second World War, when she founded the Hampstead War Nurseries. The author describes in detail this important period of Anna Freud's career, and discusses the impact it had on later work. He explores the theoretical contribution that Anna Freud made in the post-war years to the debate about the place of direct observation in psychoanalysis, and concludes that Anna Freud's 'double approach' (direct observation plus analytic reconstruction) still has a great deal to offer as a method of both psychoanalytic research and education.

Taxing sulfur dioxide emission allowances

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

Nelson, G.L.

1993-09-15

The acid rain control program authorized by Title IV of the Clean Air Act Amendments of 1990 (CAAA) was designed to reduce the adverse effects of acid rain by limiting emissions of sulfur dioxide (SO[sub 2]) into the atmosphere. The program is a complex scheme involving the issuance, consumption, holding, and trading of emission allowances for SO[sub 2]. Not surprisingly, electric utilities will face federal income tax issues in connection with the program. Under the emission allowance program, the U.S. Environmental Protection Agency (EPA) will issue emission allowance to owners or operators of certain utility power plants at no costmore » to the recipients. An emission allowance is an authorization to emit one ton of SO[sub 2] during or after the calendar year for which it is issued. If a utility power plant subject to the program emits SO[sub 2] in excess of its allowances, the owner or operator will be subject to a penalty of $2,000 a ton, and must offset the excess emissions with allowances in the subsequent year. Allowances may be bought and sold. Phase I of the program begins January 1, 1995, and will apply to 110 utility generating units. Phase II takes effect January 1, 2000, and will include most electric utility generating units. EPA will withhold a specified number of allowances for direct sale and auction. The resulting proceeds will be paid to the utilities from which the allowances were withheld. The Internal Revenue Service (IRS) has provided somewhat limited guidance on several tax issues raised by the program. Significant tax issues and the positions articulated by the IRS (if any) are discussed in this article.« less

An accuracy measurement method for star trackers based on direct astronomic observation

PubMed Central

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-01-01

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

An accuracy measurement method for star trackers based on direct astronomic observation.

PubMed

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-03-07

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

Capturing the complexity of first opinion small animal consultations using direct observation

PubMed Central

Robinson, N. J.; Brennan, M. L.; Cobb, M.; Dean, R. S.

2015-01-01

Various different methods are currently being used to capture data from small animal consultations. The aim of this study was to develop a tool to record detailed data from consultations by direct observation. A second aim was to investigate the complexity of the consultation by examining the number of problems discussed per patient. A data collection tool was developed and used during direct observation of small animal consultations in eight practices. Data were recorded on consultation type, patient signalment and number of problems discussed. During 16 weeks of data collection, 1901 patients were presented. Up to eight problems were discussed for some patients; more problems were discussed during preventive medicine consultations than during first consultations (P<0.001) or revisits (P<0.001). Fewer problems were discussed for rabbits than cats (P<0.001) or dogs (P<0.001). Age was positively correlated with discussion of specific health problems and negatively correlated with discussion of preventive medicine. Consultations are complex with multiple problems frequently discussed, suggesting comorbidity may be common. Future research utilising practice data should consider how much of this complexity needs to be captured, and use appropriate methods accordingly. The findings here have implications for directing research and education as well as application in veterinary practice. PMID:25262057

Direct observations of galactic cosmic rays

NASA Astrophysics Data System (ADS)

Müller, Dietrich

2012-08-01

The mysterious " radiation ... entering our atmosphere from above" discovered by Hess in 1912 is now known to be dominated by relativistic charged particles, mostly with energies in the GeV-range, but extending to energies higher by many orders of magnitude. As none of these particles can penetrate the earth's atmosphere without interaction, detailed studies of their composition and energy spectra require observations with high-altitude balloons or spacecraft. This became possible only towards the middle of the 20th century. The direct measurements have now revealed much detail about the Galactic cosmic rays below 1015eV, but do not yet provide much overlap with the air-shower region of energies. A historic overview of the measurements is given, beginning with the realization that the majority of the cosmic rays are protons. The discovery and astrophysical significance of the heavier nuclei, and of the ultra-heavy nuclei beyond iron and up to the actinides, are then described, and measurements of the isotopic composition are discussed. Observations of the individual energy spectra are reviewed, and finally, the detection of electrons, positrons, and anti-protons in the cosmic rays, and the searches for exotic or unusual phenomena are summarized. Emphasis is given to the fact that all of these discoveries have become possible through the evolution of increasingly sophisticated detection techniques, a process that is continuing through the present time. The precise knowledge of the abundance distributions of the elements in the cosmic rays and of their isotopic composition permits a comparison with the "universal abundance scale" and provides strong constraints on the origin of the cosmic-ray material in the interstellar medium. "Clock-isotopes" reveal the time history of the particles. The shapes of the energy spectra of the individual cosmic-ray components are related to evolving ideas about particle acceleration and propagation in the Galaxy. In conclusion

Direct observations of a flare related coronal and solar wind disturbance

NASA Technical Reports Server (NTRS)

Gosling, J. T.; Hildner, E.; Macqueen, R. M.; Munro, R. H.; Poland, A. I.; Ross, C. L.

1975-01-01

Numerous mass ejections from the sun have been detected with orbiting coronagraphs. Here for the first time we document and discuss the direct association of a coronagraph observed mass ejection, which followed a 2B flare, with a large interplanetary shock wave disturbance observed at 1 AU. Estimates of the mass and energy content of the coronal disturbance are in reasonably good agreement with estimates of the mass and energy content of the solar wind disturbance at 1 AU. The energy estimates as well as the transit time of the disturbance are also in good agreement with numerical models of shock wave propagation in the solar wind.

Catalytic carbene transfer allows the direct customization of cyclic purine dinucleotides.

PubMed

Fei, Na; Häussinger, Daniel; Blümli, Seraina; Laventie, Benoît-Joseph; Bizzini, Lorenzo D; Zimmermann, Kaspar; Jenal, Urs; Gillingham, Dennis

2014-08-11

We describe a simple method for the direct modification of nucleobases in cyclic purine dinucleotides, important signalling molecules in both prokaryotes and eukaryotes. The method tolerates all members of the cyclic dinucleotide family and could be used to modulate their function or introduce useful side-chains such as fluorophores and photo-crosslinking groups.

Participant observation of time allocation, direct patient contact and simultaneous activities in hospital physicians.

PubMed

Weigl, Matthias; Müller, Andreas; Zupanc, Andrea; Angerer, Peter

2009-06-29

Hospital physicians' time is a critical resource in medical care. Two aspects are of interest. First, the time spent in direct patient contact - a key principle of effective medical care. Second, simultaneous task performance ('multitasking') which may contribute to medical error, impaired safety behaviour, and stress. There is a call for instruments to assess these aspects. A preliminary study to gain insight into activity patterns, time allocation and simultaneous activities of hospital physicians was carried out. Therefore an observation instrument for time-motion-studies in hospital settings was developed and tested. 35 participant observations of internists and surgeons of a German municipal 300-bed hospital were conducted. Complete day shifts of hospital physicians on wards, emergency ward, intensive care unit, and operating room were continuously observed. Assessed variables of interest were time allocation, share of direct patient contact, and simultaneous activities. Inter-rater agreement of Kappa = .71 points to good reliability of the instrument. Hospital physicians spent 25.5% of their time at work in direct contact with patients. Most time was allocated to documentation and conversation with colleagues and nursing staff. Physicians performed parallel simultaneous activities for 17-20% of their work time. Communication with patients, documentation, and conversation with colleagues and nursing staff were the most frequently observed simultaneous activities. Applying logit-linear analyses, specific primary activities increase the probability of particular simultaneous activities. Patient-related working time in hospitals is limited. The potential detrimental effects of frequently observed simultaneous activities on performance outcomes need further consideration.

Direct observation of organic contaminant uptake, storage, and metabolism within plant roots.

PubMed

Wild, Edward; Dent, John; Thomas, Gareth O; Jones, Kevin C

2005-05-15

Two-photon excitation microscopy (TPEM) is used to visualize and track the uptake and movement of anthracene and phenanthrene from a contaminated growth medium into living unmodified roots of maize and wheat over a 56-day period. The degradation of anthracene was also directly observed within the cortex cells of both species. The power of this technique is that neither the plant nor the compound require altering (staining or sectioning) to visualize them, meaning they are in their natural form throughout the experiment. Initially both compounds bound to the epidermis along the zone of elongation, passing through the epidermal cells to reach the cortex within the root hair, and branching zones of the root. The PAHs entered the epidermis radially; however, once within the cortex cells this movement was dominated by slow lateral movement of both compounds toward the shoot. Highly focused "streams" of compound were observed to form over time; zones where phenanthrene concentrated extended up to 1500 microm in length over a 56-day period, for example, passing through several adjoining cells, and were detectable in cell walls and cell vacuoles. Radial movement was not observed to extend beyond the cortex cells to reach the vascular tissues of the plant. The longitudinal movement of both compounds was not observed to extend beyond the root base into the stem or vegetative parts of the plant. The lateral movement of both compounds within the cortex cells was dominated by movement within the cell walls, suggesting apoplastic flow through multiple cell walls, but with a low level of symplastic movement to transport compound into the cellular vacuoles. Degradation of anthracene to the partial breakdown products anthrone, anthraquinone, and hydroxyanthraquinone was observed directly in the zones of root elongation and branching. The technique and observations have important applications to the fields of agrochemistry and phytoremediation.

First direct observation of runaway electron-driven whistler waves in tokamaks

NASA Astrophysics Data System (ADS)

Spong, Donald A.

2017-10-01

Whistlers are electromagnetic waves that can be driven unstable by energetic electrons and are observed in natural plasmas, such as the ionosphere and Van Allen belts. Recent DIII-D experiments at low density demonstrate the first direct observation of whistlers in tokamaks, with 100-200 MHz waves excited by runaway electrons (REs) in the multi-MeV range. Whistler activity is correlated with RE intensity and the frequencies scale with magnetic field strength and electron density consistent with a whistler dispersion relation. Fluctuations occur in discrete frequency bands, and not a continuum as would be expected from plane wave analysis, suggesting the important role of toroidicity. An MHD model including the bounded/periodic nature of the plasma identifies multiple eigenmode branches. For a toroidal mode number n = 10, the predicted frequencies and spacing are similar to observations. The instabilities are stabilized with increasing magnetic field, as expected from the anomalous Doppler resonance. The whistler amplitudes show intermittent time variations. Predator-prey cycles with electron cyclotron emission (ECE) signals are observed, which can be interpreted as wave-induced pitch angle scattering of moderate energy REs. Such nonlinear dynamics are supported by quasi-linear simulations indicating that REs are scattered both by whistlers and high frequency magnetized plasma waves. The whistler wave predominantly scatters the high energy REs, while the magnetized plasma wave scatters the low energy REs, abruptly enhancing the ECE signal. Amplitude variations are also associated with sawtooth activity, indicating that the REs sample the q = 1 surface. These features of the RE-driven whistler have connections to ionospheric plasmas and open up new directions for the modeling and active control of tokamak REs. Work supported by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-FG02-07ER54917, DE-SC00-16268, and DE-AC05-00OR22725.

Direct observation of macrostructure formation of hierarchically structured meso-macroporous aluminosilicates with 3D interconnectivity by optical microscope.

PubMed

Lemaire, Arnaud; Rooke, Joanna Claire; Chen, Li-Hua; Su, Bao-Lian

2011-03-15

Hierarchically structured spongy meso-macroporous aluminosilicates with high tetrahedral aluminum content were synthesized from a mixture of single molecular alkoxide precursor, (sec-BuO)2-Al-O-Si(OEt)3, already containing Si-O-Al bonds, and a silica coreactant, tetramethoxysilane (TMOS). The spontaneous byproduct templated macroporous structure formation has been directly visualized using in situ high-resolution optical microscopy (OM), allowing the crucial observation of a microbubble dispersion which is directly correlated to the macrostructure observed by electronic microscopies (SEM and TEM). This discovery leads to a comparative study with meso-macroporous pure metal oxide and to a proposal of the formation mechanism of meso-macroporous aluminosilicates with 3D interconnectivity. The aluminosilicate phase/microbubbles emulsion is produced by a phase separation process occurring between the aluminosilicate nanoparticles and the liquid hydrolysis-condensation reaction byproducts (water, methanol, ethanol, and butanol). The use of alkoxysilane improves the heterocondensation rates between the highly reactive aluminum alkoxide part of the single precursor and added silica species but, above all, leads to the spontaneous generation of an unusual meso-macroporosity in alkaline media. The particles obtained at pH = 13.0 featured regular micrometer-sized macrospheres separated by very thin mesoporous walls and connected by submicrometric openings, providing a 3D interconnectivity. The slight increase in pH value to 13.5 induced significant modifications in morphology and textural properties due to the slower gelification process of the aluminosilicate phase, resulting in the formation of an aluminosilicate material constituted of 1-2 µm large independent hollow mesoporous spheres.

Direct observation of resonance scattering patterns in single silicon nanoparticles

NASA Astrophysics Data System (ADS)

Valuckas, Vytautas; Paniagua-Domínguez, Ramón; Fu, Yuan Hsing; Luk'yanchuk, Boris; Kuznetsov, Arseniy I.

2017-02-01

We present the first direct observation of the scattering patterns of electric and magnetic dipole resonances excited in a single silicon nanosphere. Almost perfectly spherical silicon nanoparticles were fabricated and deposited on a 30 nm-thick silicon nitride membrane in an attempt to minimize particle—substrate interaction. Measurements were carried out at visible wavelengths by means of the Fourier microscopy in a dark-field illumination setup. The obtained back-focal plane images clearly reveal the characteristic scattering patterns associated with each resonance and are found to be in a good agreement with the simulated results.

Consistency Between Convection Allowing Model Output and Passive Microwave Satellite Observations

NASA Astrophysics Data System (ADS)

Bytheway, J. L.; Kummerow, C. D.

2018-01-01

Observations from the Global Precipitation Measurement (GPM) core satellite were used along with precipitation forecasts from the High Resolution Rapid Refresh (HRRR) model to assess and interpret differences between observed and modeled storms. Using a feature-based approach, precipitating objects were identified in both the National Centers for Environmental Prediction Stage IV multisensor precipitation product and HRRR forecast at lead times of 1, 2, and 3 h at valid times corresponding to GPM overpasses. Precipitating objects were selected for further study if (a) the observed feature occurred entirely within the swath of the GPM Microwave Imager (GMI) and (b) the HRRR model predicted it at all three forecast lead times. Output from the HRRR model was used to simulate microwave brightness temperatures (Tbs), which were compared to those observed by the GMI. Simulated Tbs were found to have biases at both the warm and cold ends of the distribution, corresponding to the stratiform/anvil and convective areas of the storms, respectively. Several experiments altered both the simulation microphysics and hydrometeor classification in order to evaluate potential shortcomings in the model's representation of precipitating clouds. In general, inconsistencies between observed and simulated brightness temperatures were most improved when transferring snow water content to supercooled liquid hydrometeor classes.

Objectively Optimized Observation Direction System Providing Situational Awareness for a Sensor Web

NASA Astrophysics Data System (ADS)

Aulov, O.; Lary, D. J.

2010-12-01

There is great utility in having a flexible and automated objective observation direction system for the decadal survey missions and beyond. Such a system allows us to optimize the observations made by suite of sensors to address specific goals from long term monitoring to rapid response. We have developed such a prototype using a network of communicating software elements to control a heterogeneous network of sensor systems, which can have multiple modes and flexible viewing geometries. Our system makes sensor systems intelligent and situationally aware. Together they form a sensor web of multiple sensors working together and capable of automated target selection, i.e. the sensors “know” where they are, what they are able to observe, what targets and with what priorities they should observe. This system is implemented in three components. The first component is a Sensor Web simulator. The Sensor Web simulator describes the capabilities and locations of each sensor as a function of time, whether they are orbital, sub-orbital, or ground based. The simulator has been implemented using AGIs Satellite Tool Kit (STK). STK makes it easy to analyze and visualize optimal solutions for complex space scenarios, and perform complex analysis of land, sea, air, space assets, and shares results in one integrated solution. The second component is target scheduler that was implemented with STK Scheduler. STK Scheduler is powered by a scheduling engine that finds better solutions in a shorter amount of time than traditional heuristic algorithms. The global search algorithm within this engine is based on neural network technology that is capable of finding solutions to larger and more complex problems and maximizing the value of limited resources. The third component is a modeling and data assimilation system. It provides situational awareness by supplying the time evolution of uncertainty and information content metrics that are used to tell us what we need to observe and the

49 CFR 40.67 - When and how is a directly observed collection conducted?

Code of Federal Regulations, 2010 CFR

2010-10-01

...(e)); or (3) The temperature on the original specimen was out of range (see § 40.65(b)(5)); or (4... refusal to test. (n) As the collector, when you learn that a directly observed collection should have been...

Costs and cost-effectiveness of different DOT strategies for the treatment of tuberculosis in Pakistan. Directly Observed Treatment.

PubMed

Khan, M A; Walley, J D; Witter, S N; Imran, A; Safdar, N

2002-06-01

An economic study was conducted alongside a clinical trial at three sites in Pakistan to establish the costs and effectiveness of different strategies for implementing directly observed treatment (DOT) for tuberculosis. Patients were randomly allocated to one of three arms: DOTS with direct observation by health workers (at health centres or by community health workers); DOTS with direct observation by family members; and DOTS without direct observation. The clinical trial found no statistically significant difference in cure rate for the different arms. The economic study collected data on the full range of health service costs and patient costs of the different treatment arms. Data were also disaggregated by gender, rural and urban patients, by treatment site and by economic categories, to investigate the costs of the different strategies, their cost-effectiveness and the impact that they might have on patient compliance with treatment. The study found that direct observation by health centre-based health workers was the least cost-effective of the strategies tested (US dollars 310 per case cured). This is an interesting result, as this is the model recommended by the World Health Organization and International Union against Tuberculosis and Lung Disease. Attending health centres daily during the first 2 months generated high patient costs (direct and in terms of time lost), yet cure rates for this group fell below those of the non-observed group (58%, compared with 62%). One factor suggested by this study is that the high costs of attending may be deterring patients, and in particular, economically active patients who have most to lose from the time taken by direct observation. Without stronger evidence of benefits, it is hard to justify the costs to health services and patients that this type of direct observation imposes. The self-administered group came out as most cost-effective (164 dollars per case cured). The community health worker sub-group achieved the

A Comparison of Assessment Tools: Is Direct Observation an Improvement Over Objective Structured Clinical Examinations for Communications Skills Evaluation?

PubMed

Goch, Abraham M; Karia, Raj; Taormina, David; Kalet, Adina; Zuckerman, Joseph; Egol, Kenneth A; Phillips, Donna

2018-04-01

Evaluation of resident physicians' communications skills is a challenging task and is increasingly accomplished with standardized examinations. There exists a need to identify the effective, efficient methods for assessment of communications skills. We compared objective structured clinical examination (OSCE) and direct observation as approaches for assessing resident communications skills. We conducted a retrospective cohort analysis of orthopaedic surgery resident physicians at a single tertiary care academic institution, using the Institute for Healthcare Communication "4 Es" model for effective communication. Data were collected between 2011 and 2015. A total of 28 residents, each with OSCE and complete direct observation assessment checklists, were included in the analysis. Residents were included if they had 1 OSCE assessment and 2 or more complete direct observation assessments. There were 28 of a possible 59 residents (47%) included. A total of 89% (25 of 28) of residents passed the communications skills OSCE; only 54% (15 of 28) of residents passed the direct observation communications assessment. There was a positive, moderate correlation between OSCE and direct observation scores overall ( r  = 0.415, P  = .028). There was no agreement between OSCE and direct observation in categorizing residents into passing and failing scores (κ = 0.205, P  = .16), after adjusting for chance agreement. Our results suggest that OSCE and direct observation tools provide different insights into resident communications skills (simulation of rare and challenging situations versus real-life daily encounters), and may provide useful perspectives on resident communications skills in different contexts.

Mid-Cretaceous charred fossil flowers reveal direct observation of arthropod feeding strategies

PubMed Central

Hartkopf-Fröder, Christoph; Rust, Jes; Wappler, Torsten; Friis, Else Marie; Viehofen, Agnes

2012-01-01

Although plant–arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role in decomposition. PMID:21900310

Processing Doppler Lidar and Cloud Radar Observations for Analysis of Convective Mass Flux Parameterizations Using DYNAMO Direct Observations

DTIC Science & Technology

2014-09-30

for Analysis of Convective Mass Flux Parameterizations Using DYNAMO Direct Observations R. Michael Hardesty CIRES/University of Colorado/NOAA 325...the RV-Revell during legs 2 & 3 of the DYNAMO experiement to help characterize vertical transport through the boundary layer and to build statistics...obtained during DYNAMO , and to investigate whether cold pools that emanate from convection organize the interplay between humidity and convection and

A New Method to Directly Observe Tuberculosis Treatment: Skype Observed Therapy, a Patient-Centered Approach.

PubMed

Buchman, Tavora; Cabello, Celina

Tuberculosis (TB) treatment completion is in part determined by patient's adherence to long-term drug regimens. To best ensure compliance, directly observed therapy (DOT) is considered the standard of practice. Nassau County Department of Health TB Control is responsible for providing DOT to patients with TB. Tuberculosis Control sought to use and evaluate Skype Observed Therapy (SOT) as an alternative to DOT for eligible patients. The evaluation included analysis of patient's acceptance and adherence to drug regimen using SOT. Tuberculosis Control assessed staff efficiency and cost savings for this program. Percentages of SOT of patients and successful SOT visits, mileage, and travel time savings. Twenty percent of the caseload used SOT and 100% of patients who were eligible opted in. Average SOT success was 79%. Total mileage savings and time saved were $9,929.07 and 614 hours. Because SOT saves cost and time and is a suitable alternative to DOT for patients, it should be considered as part of new policies and practices in TB control programs.

Observing the epoch of galaxy formation

PubMed Central

Steidel, Charles C.

1999-01-01

Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the observations, but rapid improvement in the data will provide much more critical tests of theory in the coming years. PMID:10200244

Observing the epoch of galaxy formation.

PubMed

Steidel, C C

1999-04-13

Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the observations, but rapid improvement in the data will provide much more critical tests of theory in the coming years.

Direct observation of molecular cooperativity near the glass transition.

PubMed

Russell, E V; Israeloff, N E

2000-12-07

The increasingly sluggish response of a supercooled liquid as it nears its glass transition (for example, refrigerated honey) is prototypical of glassy dynamics found in proteins, neural networks and superconductors. The notion that molecules rearrange cooperatively has long been postulated to explain diverging relaxation times and broadened (non-exponential) response functions near the glass transition. Recently, cooperativity was observed and analysed in colloid glasses and in simulations of binary liquids well above the glass transition. But nanometre-scale studies of cooperativity at the molecular glass transition are lacking. Important issues to be resolved include the precise form of the cooperativity and its length scale, and whether the broadened response is intrinsic to individual cooperative regions, or arises only from heterogeneity in an ensemble of such regions. Here we describe direct observations of molecular cooperativity near the glass transition in polyvinylacetate (PVAc), using nanometre-scale probing of dielectric fluctuations. Molecular clusters switched spontaneously among two to four distinct configurations, producing random telegraph noise. Our analysis of these noise signals and their power spectra reveals that individual clusters exhibit transient dynamical heterogeneity and non-exponential kinetics.

Direct Observation of Markovian Behavior of the Mechanical Unfolding of Individual Proteins

PubMed Central

Cao, Yi; Kuske, Rachel; Li, Hongbin

2008-01-01

Single-molecule force-clamp spectroscopy is a valuable tool to analyze unfolding kinetics of proteins. Previous force-clamp spectroscopy experiments have demonstrated that the mechanical unfolding of ubiquitin deviates from the generally assumed Markovian behavior and involves the features of glassy dynamics. Here we use single molecule force-clamp spectroscopy to study the unfolding kinetics of a computationally designed fast-folding mutant of the small protein GB1, which shares a similar β-grasp fold as ubiquitin. By treating the mechanical unfolding of polyproteins as the superposition of multiple identical Poisson processes, we developed a simple stochastic analysis approach to analyze the dwell time distribution of individual unfolding events in polyprotein unfolding trajectories. Our results unambiguously demonstrate that the mechanical unfolding of NuG2 fulfills all criteria of a memoryless Markovian process. This result, in contrast with the complex mechanical unfolding behaviors observed for ubiquitin, serves as a direct experimental demonstration of the Markovian behavior for the mechanical unfolding of a protein and reveals the complexity of the unfolding dynamics among structurally similar proteins. Furthermore, we extended our method into a robust and efficient pseudo-dwell-time analysis method, which allows one to make full use of all the unfolding events obtained in force-clamp experiments without categorizing the unfolding events. This method enabled us to measure the key parameters characterizing the mechanical unfolding energy landscape of NuG2 with improved precision. We anticipate that the methods demonstrated here will find broad applications in single-molecule force-clamp spectroscopy studies for a wide range of proteins. PMID:18375518

Directly Observing Micelle Fusion and Growth in Solution by Liquid-Cell Transmission Electron Microscopy

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

Parent, Lucas R.; Bakalis, Evangelos; Ramírez-Hernández, Abelardo

Amphiphilic small molecules and polymers form commonplace nanoscale macromolecular compartments and bilayers, and as such are truly essential components in all cells and in many cellular processes. The nature of these architectures, including their formation, phase changes, and stimuli-response behaviors, is necessary for the most basic functions of life, and over the past half-century, these natural micellar structures have inspired a vast diversity of industrial products, from biomedicines to detergents, lubricants, and coatings. The importance of these materials and their ubiquity have made them the subject of intense investigation regarding their nanoscale dynamics with increasing interest in obtaining sufficient temporalmore » and spatial resolution to directly observe nanoscale processes. However, the vast majority of experimental methods involve either bulk-averaging techniques including light, neutron, and X-ray scattering, or are static in nature including even the most advanced cryogenic transmission electron microscopy techniques. Here, we employ in situ liquid-cell transmission electron microscopy (LCTEM) to directly observe the evolution of individual amphiphilic block copolymer micellar nanoparticles in solution, in real time with nanometer spatial resolution. These observations, made on a proof-of-concept bioconjugate polymer amphiphile, revealed growth and evolution occurring by unimer addition processes and by particle-particle collision-and-fusion events. The experimental approach, combining direct LCTEM observation, quantitative analysis of LCTEM data, and correlated in silico simulations, provides a unique view of solvated soft matter nanoassemblies as they morph and evolve in time and space, enabling us to capture these phenomena in solution.« less

Wide-field direct CCD observations supporting the Astro-1 Space Shuttle mission's Ultraviolet Imaging Telescope

NASA Technical Reports Server (NTRS)

Hintzen, Paul; Angione, Ron; Talbert, Freddie; Cheng, K.-P.; Smith, Eric; Stecher, Theodore P.

1993-01-01

Wide field direct CCD observations are being obtained to support and complement the vacuum-ultraviolet (VUV) images provided by Astro's Ultraviolet Imaging Telescope (UIT) during a Space Shuttle flight in December 1990. Because of the wide variety of projects addressed by UIT, the fields observed include (1) galactic supernova remnants such as the Cygnus Loop and globular clusters such as Omega Cen and M79; (2) the Magellanic Clouds, M33, M81, and other galaxies in the Local Group; and (3) rich clusters of galaxies, principally the Perseus cluster and Abell 1367. Ground-based observations have been obtained for virtually all of the Astro-1 UIT fields. The optical images allow identification of individual UV sources in each field and provide the long baseline in wavelength necessary for accurate analysis of UV-bright sources. To facilitate use of our optical images for analysis of UIT data and other projects, we plan to archive them, with the UIT images, at the National Space Science Data Center (NSSDC), where they will be universally accessible via anonymous FTP. The UIT, one of three telescopes comprising the Astro spacecraft, is a 38-cm f/9 Ritchey-Chretien telescope on which high quantum efficiency, solar-blind image tubes are used to record VUV images on photographic film. Five filters with passbands centered between 1250A and 2500A provide both VUV colors and a measurement of extinction via the 2200A dust feature. The resulting calibrated VUV pictures are 40 arcminutes in diameter at 2.5 arcseconds resolution. The capabilities of UIT, therefore, complement HST's WFPC: the latter has 40 times greater collecting area, while UIT's usable field has 170 times WFPC's field area.

Direct observation of students during clerkship rotations: a multiyear descriptive study.

PubMed

Howley, Lisa D; Wilson, William G

2004-03-01

To determine how often students report that they are observed while performing physical examinations and taking histories during clerkship rotations. From 1999-2001, 397 students at the University of Virginia School of Medicine were asked at the end of their third year to report the number of times they had been observed by a resident or faculty member while taking histories and performing physical examinations on six rotations. Three hundred and forty-five students (87%) returned the survey instrument; of these, 322 (81%) returned instruments with complete information. On average, the majority reported that they had never been observed by a faculty member while taking a history (51%), performing a focused physical examination (54%), or a complete physical examination (81%). The majority (60%) reported that they had never been observed by a resident while performing a complete physical examination. Faculty observations occurred most frequently during the four-week family medicine rotation and least frequently during the 12-week surgery rotation. The length of the clerkship rotation was inversely related to the number of reported observations, chi(2) (5, n = 295) = 127.85, p <.000. Although alternative assessments of clinical skills are becoming more common in medical education, faculty ratings based on direct observation are still prominent. The data in this study reflect that these observations may actually be occurring quite infrequently, if at all. Decreasing the evaluative weight of faculty and resident ratings during the clerkship rotation may be necessary. Otherwise, efforts should be made to increase the validity of these ratings.

40 CFR 35.2025 - Allowance and advance of allowance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... advance of allowance. (a) Allowance. Step 2+3 and Step 3 grant agreements will include an allowance for facilities planning and design of the project and Step 7 agreements will include an allowance for facility... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allowance and advance of allowance. 35...

Direct TEM observations of growth mechanisms of two-dimensional MoS2 flakes

PubMed Central

Fei, Linfeng; Lei, Shuijin; Zhang, Wei-Bing; Lu, Wei; Lin, Ziyuan; Lam, Chi Hang; Chai, Yang; Wang, Yu

2016-01-01

A microscopic understanding of the growth mechanism of two-dimensional materials is of particular importance for controllable synthesis of functional nanostructures. Because of the lack of direct and insightful observations, how to control the orientation and the size of two-dimensional material grains is still under debate. Here we discern distinct formation stages for MoS2 flakes from the thermolysis of ammonium thiomolybdates using in situ transmission electron microscopy. In the initial stage (400 °C), vertically aligned MoS2 structures grow in a layer-by-layer mode. With the increasing temperature of up to 780 °C, the orientation of MoS2 structures becomes horizontal. When the growth temperature reaches 850 °C, the crystalline size of MoS2 increases by merging adjacent flakes. Our study shows direct observations of MoS2 growth as the temperature evolves, and sheds light on the controllable orientation and grain size of two-dimensional materials. PMID:27412892

20170308 - Higher Throughput Toxicokinetics to Allow ...

EPA Pesticide Factsheets

As part of "Ongoing EDSP Directions & Activities" I will present CSS research on high throughput toxicokinetics, including in vitro data and models to allow rapid determination of the real world doses that may cause endocrine disruption. This is a presentation as part of the U.S. Environmental Protection Agency – Japan Ministry of the Environment 12th Bilateral Meeting on Endocrine Disruption Test Methods Development.

Direct observation of weight-related communication in primary care: a systematic review.

PubMed

McHale, Calum T; Laidlaw, Anita H; Cecil, Joanne E

2016-08-01

Primary care is ideally placed to play an effective role in patient weight management; however, patient weight is seldom discussed in this context. A synthesis of studies that directly observe weight discussion in primary care is required to more comprehensively understand and improve primary care weight-related communication. To systematically identify and examine primary care observational research that investigates weight-related communication and its relationship to patient weight outcomes. A systematic review of literature published up to August 2015, using seven electronic databases (including MEDLINE, Scopus and PsycINFO), was conducted using search terms such as overweight, obese and/or doctor-patient communication. Twenty papers were included in the final review. Communication analysis focused predominantly on 'practitioner' use of specific patient-centred communication. Practitioner use of motivational interviewing was associated with improved patient weight-related outcomes, including patient weight loss and increased patient readiness to lose weight; however, few studies measured patient weight-related outcomes. Studies directly observing weight-related communication in primary care are scarce and limited by a lack of focus on patient communication and patient weight-related outcomes. Future research should measure practitioner and patient communications during weight discussion and their impact on patient weight-related outcomes. This knowledge may inform the development of a communication intervention to assist practitioners to more effectively discuss weight with their overweight and/or obese patients. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Affective Evaluations of Objects Are Influenced by Observed Gaze Direction and Emotional Expression

ERIC Educational Resources Information Center

Bayliss, Andrew P.; Frischen, Alexandra; Fenske, Mark J.; Tipper, Steven P.

2007-01-01

Gaze direction signals another person's focus of interest. Facial expressions convey information about their mental state. Appropriate responses to these signals should reflect their combined influence, yet current evidence suggests that gaze-cueing effects for objects near an observed face are not modulated by its emotional expression. Here, we…

Notes From the Field: Direct Observation Versus Rating by Videos for the Assessment of Central Venous Catheterization Skills.

PubMed

Ma, Irene W Y; Zalunardo, Nadia; Brindle, Mary E; Hatala, Rose; McLaughlin, Kevin

2015-09-01

Blinded assessments of technical skills using video-recordings may offer more objective assessments than direct observations. This study seeks to compare these two modalities. Two trained assessors independently assessed 18 central venous catheterization performances by direct observation and video-recorded assessments using two tools. Although sound quality was deemed adequate in all videos, portions of the video for wire handling and drape handling were frequently out of view (n = 13, 72% for wire-handling; n = 17, 94% for drape-handling). There were no differences in summary global rating scores, checklist scores, or pass/fail decisions for either modality (p > 0.05). Inter-rater reliability was acceptable for both modalities. Of the 26 discrepancies identified between direct observation and video-recorded assessments, three discrepancies (12%) were due to inattention during video review, while one (4%) discrepancy was due to inattention during direct observation. In conclusion, although scores did not differ between the two assessment modalities, techniques of video-recording may significantly impact individual items of assessments. © The Author(s) 2014.

Advancing Patient-Centered Care in Tuberculosis Management: A Mixed-Methods Appraisal of Video Directly Observed Therapy

PubMed Central

Holzman, Samuel B; Zenilman, Avi; Shah, Maunank

2018-01-01

Abstract Background Directly observed therapy (DOT) remains an integral component of treatment support and adherence monitoring in tuberculosis care. In-person DOT is resource intensive and often burdensome for patients. Video DOT (vDOT) has been proposed as an alternative to increase treatment flexibility and better meet patient-specific needs. Methods We conducted a pragmatic, prospective pilot implementation of vDOT at 3 TB clinics in Maryland. A mixed-methods approach was implemented to assess (1) effectiveness, (2) acceptability, and (3) cost. Medication adherence on vDOT was compared with that of in-person DOT. Interviews and surveys were conducted with patients and providers before and after implementation, with framework analysis utilized to extract salient themes. Last, a cost analysis assessed the economic impacts of vDOT implementation across heterogeneous clinic structures. Results Medication adherence on vDOT was comparable to that of in-person DOT (94% vs 98%, P = .17), with a higher percentage of total treatment doses (inclusive of weekend/holiday self-administration) ultimately observed during the vDOT period (72% vs 66%, P = .03). Video DOT was well received by staff and patients alike, who cited increased treatment flexibility, convenience, and patient privacy. Our cost analysis estimated a savings with vDOT of $1391 per patient for a standard 6-month treatment course. Conclusions Video DOT is an acceptable and important option for measurement of TB treatment adherence and may allow a higher proportion of prescribed treatment doses to be observed, compared with in-person DOT. Video DOT may be cost-saving and should be considered as a component of individualized, patient-centered case management plans. PMID:29732378

Advancing Patient-Centered Care in Tuberculosis Management: A Mixed-Methods Appraisal of Video Directly Observed Therapy.

PubMed

Holzman, Samuel B; Zenilman, Avi; Shah, Maunank

2018-04-01

Directly observed therapy (DOT) remains an integral component of treatment support and adherence monitoring in tuberculosis care. In-person DOT is resource intensive and often burdensome for patients. Video DOT (vDOT) has been proposed as an alternative to increase treatment flexibility and better meet patient-specific needs. We conducted a pragmatic, prospective pilot implementation of vDOT at 3 TB clinics in Maryland. A mixed-methods approach was implemented to assess (1) effectiveness, (2) acceptability, and (3) cost. Medication adherence on vDOT was compared with that of in-person DOT. Interviews and surveys were conducted with patients and providers before and after implementation, with framework analysis utilized to extract salient themes. Last, a cost analysis assessed the economic impacts of vDOT implementation across heterogeneous clinic structures. Medication adherence on vDOT was comparable to that of in-person DOT (94% vs 98%, P = .17), with a higher percentage of total treatment doses (inclusive of weekend/holiday self-administration) ultimately observed during the vDOT period (72% vs 66%, P = .03). Video DOT was well received by staff and patients alike, who cited increased treatment flexibility, convenience, and patient privacy. Our cost analysis estimated a savings with vDOT of $1391 per patient for a standard 6-month treatment course. Video DOT is an acceptable and important option for measurement of TB treatment adherence and may allow a higher proportion of prescribed treatment doses to be observed, compared with in-person DOT. Video DOT may be cost-saving and should be considered as a component of individualized, patient-centered case management plans.

Combined use of leaf size and economics traits allows direct comparison of hydrophyte and terrestrial herbaceous adaptive strategies.

PubMed

Pierce, Simon; Brusa, Guido; Sartori, Matteo; Cerabolini, Bruno E L

2012-04-01

Hydrophytes generally exhibit highly acquisitive leaf economics. However, a range of growth forms is evident, from small, free-floating and rapidly growing Lemniden to large, broad-leaved Nymphaeiden, denoting variability in adaptive strategies. Traits used to classify adaptive strategies in terrestrial species, such as canopy height, are not applicable to hydrophytes. We hypothesize that hydrophyte leaf size traits and economics exhibit sufficient overlap with terrestrial species to allow a common classification of plant functional types, sensu Grime's CSR theory. Leaf morpho-functional traits were measured for 61 species from 47 water bodies in lowland continental, sub-alpine and alpine bioclimatic zones in southern Europe and compared against the full leaf economics spectrum and leaf size range of terrestrial herbs, and between hydrophyte growth forms. Hydrophytes differed in the ranges and mean values of traits compared with herbs, but principal components analysis (PCA) demonstrated that both groups shared axes of trait variability: PCA1 encompassed size variation (area and mass), and PCA2 ranged from relatively dense, carbon-rich leaves to nitrogen-rich leaves of high specific leaf area (SLA). Most growth forms exhibited trait syndromes directly equivalent to herbs classified as R adapted, although Nymphaeiden ranged between C and SR adaptation. Our findings support the hypothesis that hydrophyte adaptive strategy variation reflects fundamental trade-offs in economics and size that govern all plants, and that hydrophyte adaptive strategies can be directly compared with terrestrial species by combining leaf economics and size traits.

Direct retrieval of ocean surface evaporation and latent heat flux from the spacebased observations

NASA Technical Reports Server (NTRS)

Liu, W. T.; Tang, W.

2000-01-01

The Tropical Rain Measuring Mission (TRMM) provides the opportunity to improve the spacebased estimation of evaporation. An algorithm for retrieving evaporation directly from the radiances observed by the TRMM Microwave Imager and its validation results are described.

Direct observation of aqueous secondary organic aerosol from biomass-burning emissions

PubMed Central

Massoli, Paola; Paglione, Marco; Giulianelli, Lara; Carbone, Claudio; Rinaldi, Matteo; Decesari, Stefano; Sandrini, Silvia; Costabile, Francesca; Gobbi, Gian Paolo; Pietrogrande, Maria Chiara; Visentin, Marco; Scotto, Fabiana; Fuzzi, Sandro; Facchini, Maria Cristina

2016-01-01

The mechanisms leading to the formation of secondary organic aerosol (SOA) are an important subject of ongoing research for both air quality and climate. Recent laboratory experiments suggest that reactions taking place in the atmospheric liquid phase represent a potentially significant source of SOA mass. Here, we report direct ambient observations of SOA mass formation from processing of biomass-burning emissions in the aqueous phase. Aqueous SOA (aqSOA) formation is observed both in fog water and in wet aerosol. The aqSOA from biomass burning contributes to the “brown” carbon (BrC) budget and exhibits light absorption wavelength dependence close to the upper bound of the values observed in laboratory experiments for fresh and processed biomass-burning emissions. We estimate that the aqSOA from residential wood combustion can account for up to 0.1–0.5 Tg of organic aerosol (OA) per y in Europe, equivalent to 4–20% of the total OA emissions. Our findings highlight the importance of aqSOA from anthropogenic emissions on air quality and climate. PMID:27551086

Time-gated luminescence microscopy allowing direct visual inspection of lanthanide-stained microorganisms in background-free condition.

PubMed

Jin, Dayong; Piper, James A

2011-03-15

Application of standard immuno-fluorescence microscopy techniques for detection of rare-event microorganisms in dirty samples is severely limited by autofluorescence of nontarget organisms or other debris. Time-gated detection using gateable array detectors in combination with microsecond-lifetime luminescent bioprobes (usually lanthanide-based) is highly effective in suppression of (nanosecond-lifetime) autofluorescence background; however, the complexity and cost of the instrumentation is a major barrier to application of these techniques to routine diagnostics. We report a practical, low-cost implementation of time-gated luminescence detection in a standard epifluorescence microscope which has been modified to include a high-power pulsed UV light-emitting diode (LED) illumination source and a standard fast chopper inserted in the focal plane behind a microscope eyepiece. Synchronization of the pulsed illumination/gated detection cycle is driven from the clock signal from the chopper. To achieve time-gated luminescence intensities sufficient for direct visual observation, we use high cycle rates, up to 2.5 kHz, taking advantage of the fast switching capabilities of the LED source. We have demonstrated real-time direct-visual inspection of europium-labeled Giardia lamblia cysts in dirty samples and Cryptosporidium parvum oocysts in fruit juice concentrate. The signal-to-background ratio has been enhanced by a factor of 18 in time-gated mode. The availability of low-cost, robust time-gated microscopes will aid development of long-lifetime luminescence bioprobes and accelerate their application in routine laboratory diagnostics.

Direct observation of interface instability during crystal growth

NASA Technical Reports Server (NTRS)

Tiller, W. A.; Feigelson, R. S.; Elwell, D.

1982-01-01

The general aim of this investigation was to study interface stability and solute segregation phenomena during crystallization of a model system. Emphasis was to be placed on direct observational studies partly because this offered the possibility at a later stage of performing related experiments under substantially convection-free conditions in the space shuttle. The major achievements described in this report are: (1) the development of a new model system for fundamental studies of crystal growth from the melt and the measurement of a range of material parameters necessary for comparison of experiment with theory. (2) The introduction of a new method of measuring segregation coefficient using absorption of a laser beam by the liquid phase. (3) The comparison of segregation in crystals grown by gradient freezing and by pulling from the melt. (4) The introduction into the theory of solute segregation of an interface field term and comparison with experiment. (5) The introduction of the interface field term into the theories of constitutional supercooling and morphological stability and assessment of its importance.

First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks

DOE PAGES

Spong, D. A.; Heidbrink, W. W.; Paz-Soldan, C.; ...

2018-04-11

DIII-D experiments at low density (n e ~10 19 m -3) have directly measured whistler waves in the 100– 200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limitcycle- like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission thatmore » follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.« less

First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks

NASA Astrophysics Data System (ADS)

Spong, D. A.; Heidbrink, W. W.; Paz-Soldan, C.; Du, X. D.; Thome, K. E.; Van Zeeland, M. A.; Collins, C.; Lvovskiy, A.; Moyer, R. A.; Austin, M. E.; Brennan, D. P.; Liu, C.; Jaeger, E. F.; Lau, C.

2018-04-01

DIII-D experiments at low density (ne˜1019 m-3 ) have directly measured whistler waves in the 100-200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limit-cycle-like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission that follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.

First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks.

PubMed

Spong, D A; Heidbrink, W W; Paz-Soldan, C; Du, X D; Thome, K E; Van Zeeland, M A; Collins, C; Lvovskiy, A; Moyer, R A; Austin, M E; Brennan, D P; Liu, C; Jaeger, E F; Lau, C

2018-04-13

DIII-D experiments at low density (n_{e}∼10^{19}  m^{-3}) have directly measured whistler waves in the 100-200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limit-cycle-like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission that follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.

First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks

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

Spong, D. A.; Heidbrink, W. W.; Paz-Soldan, C.

DIII-D experiments at low density (n e ~10 19 m -3) have directly measured whistler waves in the 100– 200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limitcycle- like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission thatmore » follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.« less

Direct observation of episodic growth in an abyssal xenophyophore (Protista)

NASA Astrophysics Data System (ADS)

Gooday, A. J.; Bett, B. J.; Pratt, D. N.

1993-11-01

Three specimens of the xenophyophore Reticulammina labyrinthica were photographed on the Madeira Abyssal Plain (31°6.1'N, 21°10.9'W; 4944 m) using the Bathysnap time-lapse camera system. During the 8 month observation period, the specimens underwent an estimated 3-10 fold increase in volume. Growth occurred episodically in several distinct phases, each lasting 2-3 days, during which sediment was collected and incorporated into the test. These phases were separated by fairly regular periods of about 2 months when the organisms showed little obvious activity. The growth phases were approximately synchronous between specimens. However, it is not clear whether the periodicity and apparent synchronization of these events resulted from an external (environmental) cue or whether growth is internally controlled and the synchronization arose by chance. These unique observations, which represent the first direct measurement of growth in any abyssal organism living outside a hydrothermal vent field, suggest that xenophyophores combine test growth with deposit feeding. The tests appear to grow more quickly, and to be more active, dynamic structures, than previously believed.

Apparatus for Direct Optical Fiber Through-Lens Illumination of Microscopy or Observational Objects

NASA Technical Reports Server (NTRS)

Kadogawa, Hiroshi (Inventor)

2001-01-01

In one embodiment of the invention, a microscope or other observational apparatus, comprises a hollow tube, a lens mounted to the tube, a light source and at least one flexible optical fiber having an input end and an output end. The input end is positioned to receive light from the light source, and the output end is positioned within the tube so as to directly project light along a straight path to the lens to illuminate an object to be viewed. The path of projected light is uninterrupted and free of light deflecting elements. By passing the light through the lens, the light can be diffused or otherwise defocused to provide more uniform illumination across the surface of the object, increasing the quality of the image of the object seen by the viewer. The direct undeflected and uninterrupted projection of light, without change of direction, eliminates the need for light-deflecting elements, such as beam-splitters, mirrors, prisms, or the like, to direct the projected light towards the object.

The 'not-so-strange' body in the mirror: A principal components analysis of direct and mirror self-observation.

PubMed

Jenkinson, Paul M; Preston, Catherine

2017-02-01

In this study we adopted a psychometric approach to examine how the body is subjectively experienced in a mirror. One hundred and twenty-four healthy participants viewed their body for five minutes directly or via a mirror, and then completed a 20-item questionnaire designed to capture subjective experiences of the body. PCA revealed a two-component structure for both direct and mirror conditions, comprising body evaluations (and alienation) and unusual feelings and perceptions. The relationship between these components and pre-existing tendencies for appearance anxiety, body dysmorphic-type beliefs, dissociative symptomatology, self-objectification and delusion ideation further supported the similarity between direct and mirror conditions; however, the occurrence of strange experiences like those reported to occur during prolonged face viewing was not confirmed. These results suggest that, despite obvious differences in visual feedback, observing the body via a mirror (as an outside observer) is subjectively equivalent to observing the body directly (from our own viewpoint). Copyright © 2016 Elsevier Inc. All rights reserved.

29 CFR 779.260 - Trade-in allowances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 3 2013-07-01 2013-07-01 false Trade-in allowances. 779.260 Section 779.260 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to...

29 CFR 779.260 - Trade-in allowances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 3 2012-07-01 2012-07-01 false Trade-in allowances. 779.260 Section 779.260 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to...

29 CFR 779.260 - Trade-in allowances.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 3 2014-07-01 2014-07-01 false Trade-in allowances. 779.260 Section 779.260 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to...

Direct observation of the orbital spin Kondo effect in gallium arsenide quantum dots

NASA Astrophysics Data System (ADS)

Shang, Ru-Nan; Zhang, Ting; Cao, Gang; Li, Hai-Ou; Xiao, Ming; Guo, Guang-Can; Guo, Guo-Ping

2018-02-01

Besides the spin Kondo effect, other degrees of freedom can give rise to the pseudospin Kondo effect. We report a direct observation of the orbital spin Kondo effect in a series-coupled gallium arsenide (GaAs) double quantum dot device where orbital degrees act as pseudospin. Electron occupation in both dots induces a pseudospin Kondo effect. In a region of one net spin impurity, complete spectra with three resonance peaks are observed. Furthermore, we observe a pseudo-Zeeman effect and demonstrate its electrical controllability for the artificial pseudospin in this orbital spin Kondo process via gate voltage control. The fourfold degeneracy point is realized at a specific value supplemented by spin degeneracy, indicating a transition from the SU(2) to the SU(4) Kondo effect.

Ovarian fluid allows directional cryptic female choice despite external fertilization

PubMed Central

Alonzo, Suzanne H.; Stiver, Kelly A.; Marsh-Rollo, Susan E.

2016-01-01

In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female's reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible. PMID:27529581

Directional Wave Spectra Observed During Intense Tropical Cyclones

NASA Astrophysics Data System (ADS)

Collins, C. O.; Potter, H.; Lund, B.; Tamura, H.; Graber, H. C.

2018-02-01

Two deep-sea moorings were deployed 780 km off the coast of southern Taiwan for 4-5 months during the 2010 typhoon season. Directional wave spectra, wind speed and direction, and momentum fluxes were recorded on two Extreme Air-Sea Interaction buoys during the close passage of Severe Tropical Storm Dianmu and three tropical cyclones (TCs): Typhoon Fanapi, Super Typhoon Megi, and Typhoon Chaba. Conditions sampled include significant wave heights up to 11 m and wind speeds up to 26 m s-1. Details varied for large-scale spectral structure in frequency and direction but were mostly bimodal. The modes were generally composed of a swell system emanating from the most intense storm region and local wind-seas. The peak systems were consistently young, meaning actively forced by winds, when the storms were close. During the peaks of the most intense passages—Chaba at the northern mooring and Megi at the southern—the bimodal seas coalesced. During Chaba, the swell and wind-sea coupling directed the high frequency waves and the wind stress away from the wind direction. A spectral wave model was able reproduce many of the macrofeatures of the directional spectra.

Combined use of leaf size and economics traits allows direct comparison of hydrophyte and terrestrial herbaceous adaptive strategies

PubMed Central

Pierce, Simon; Brusa, Guido; Sartori, Matteo; Cerabolini, Bruno E. L.

2012-01-01

Background and Aims Hydrophytes generally exhibit highly acquisitive leaf economics. However, a range of growth forms is evident, from small, free-floating and rapidly growing Lemniden to large, broad-leaved Nymphaeiden, denoting variability in adaptive strategies. Traits used to classify adaptive strategies in terrestrial species, such as canopy height, are not applicable to hydrophytes. We hypothesize that hydrophyte leaf size traits and economics exhibit sufficient overlap with terrestrial species to allow a common classification of plant functional types, sensu Grime's CSR theory. Methods Leaf morpho-functional traits were measured for 61 species from 47 water bodies in lowland continental, sub-alpine and alpine bioclimatic zones in southern Europe and compared against the full leaf economics spectrum and leaf size range of terrestrial herbs, and between hydrophyte growth forms. Key Results Hydrophytes differed in the ranges and mean values of traits compared with herbs, but principal components analysis (PCA) demonstrated that both groups shared axes of trait variability: PCA1 encompassed size variation (area and mass), and PCA2 ranged from relatively dense, carbon-rich leaves to nitrogen-rich leaves of high specific leaf area (SLA). Most growth forms exhibited trait syndromes directly equivalent to herbs classified as R adapted, although Nymphaeiden ranged between C and SR adaptation. Conclusions Our findings support the hypothesis that hydrophyte adaptive strategy variation reflects fundamental trade-offs in economics and size that govern all plants, and that hydrophyte adaptive strategies can be directly compared with terrestrial species by combining leaf economics and size traits. PMID:22337079

Observed Arctic sea-ice loss directly follows anthropogenic CO2 emission.

PubMed

Notz, Dirk; Stroeve, Julienne

2016-11-11

Arctic sea ice is retreating rapidly, raising prospects of a future ice-free Arctic Ocean during summer. Because climate-model simulations of the sea-ice loss differ substantially, we used a robust linear relationship between monthly-mean September sea-ice area and cumulative carbon dioxide (CO 2 ) emissions to infer the future evolution of Arctic summer sea ice directly from the observational record. The observed linear relationship implies a sustained loss of 3 ± 0.3 square meters of September sea-ice area per metric ton of CO 2 emission. On the basis of this sensitivity, Arctic sea ice will be lost throughout September for an additional 1000 gigatons of CO 2 emissions. Most models show a lower sensitivity, which is possibly linked to an underestimation of the modeled increase in incoming longwave radiation and of the modeled transient climate response. Copyright © 2016, American Association for the Advancement of Science.

Associations between informant ratings of personality disorder traits, self-reports of personality, and directly observed behavior.

PubMed

Kaurin, Aleksandra; Sauerberger, Kyle S; Funder, David C

2018-03-02

Diagnoses of personality disorders (PD) must rely on judgments of observers-either clinicians or acquaintances-because personality disorders are primarily defined in terms of maladaptive interpersonal behavior. Little is known, however, about how closely acquaintances' judgments of PD traits relate to self-reports of theoretically relevant Big Five traits or directly observed behavioral outcomes in interpersonal situations. The present study examines associations between judgments of the 10 PD traits provided by close acquaintances, self-reports of PD-relevant Big Five personality traits, and observed interpersonal behaviors across three different three-person laboratory interactions (i.e., unstructured chat, cooperative task, competitive game). The sample consisted of 256 undergraduate students (130 females; M age  = 19.83, SD = 1.25). Four unacquainted observers independently rated participants' behaviors from video recordings. In line with previous work, informant reports of PD traits demonstrate strong convergent validity with relevant self-reported Big Five traits (as identified by Lynam & Widiger, 2001). Directly observed behavior is meaningfully associated with acquaintances' judgments and self-reports of PD-relevant traits, and the associations between these judgments and behavior are strongest for traits associated with histrionic and schizoid PD. Vector correlations between behavioral profiles associated with informant and self-reports show that both assessments have similar behavioral correlates. Associations between PD trait ratings and behavior appeared to differ as a function of gender, with males showing more and stronger correlations. Informants' ratings of PD traits are impressively accurate, converging both with self-reports of relevant traits and directly observed interpersonal behavior. Therefore, a comprehensive understanding of PDs and associated traits can be augmented by information from multiple acquaintances who have the

Observations and Simulations of the Impact of Wave-Current Interaction on Wave Direction in the Surf Zone

NASA Astrophysics Data System (ADS)

Hopkins, Julia; Elgar, Steve; Raubenheimer, Britt

2017-04-01

Accurately characterizing the interaction of waves and currents can improve predictions of wave propagation and subsequent sediment transport in the nearshore. Along the southern shoreline of Martha's Vineyard, MA, waves propagate across strong tidal currents as they shoal, providing an ideal environment for investigating wave-current interaction. Wave directions and mean currents observed for two 1-month-long periods in 7- and 2-m water depths along 11 km of the Martha's Vineyard shoreline have strong tidal modulations. Wave directions shift by as much as 70 degrees over a tidal cycle in 7 m depth, and by as much as 25 degrees in 2 m depth. The magnitude of the tidal modulations in the wave field decreases alongshore to the west, consistent with the observed decrease in tidal currents from 2.1 to 0.2 m/s. The observations are reproduced accurately by a numerical model (SWAN and Deflt3D-FLOW) that simulates waves and currents over the observed bathymetry. Model simulations with and without wave-current interaction and tidal depth changes demonstrate that the observed tidal modulations of the wave field primarily are caused by wave-current interaction and not by tidal changes to water depths over the nearby complex shoals. Sediment transport estimates from simulated wave conditions using a range of tidal currents and offshore wave fields indicate that the modulation of the wave field at Martha's Vineyard can impact the direction of wave-induced alongshore sediment transport, sometimes driving transport opposing the direction of the offshore incident wave field. As such, the observations and model simulations suggest the importance of wave-current interaction to tidally averaged transport in mixed-energy wave-and-current nearshore environments. Supported by ASD(R&E), NSF, NOAA (Sea Grant), and ONR.

Direct observation of hole transfer from semiconducting polymer to carbon nanotubes.

PubMed

Lan, Fei; Li, Guangyong

2013-05-08

Carbon nanotubes have been proven to play significant roles in polymer-based solar cells. However, there is intensive debate on whether carbon nanotube behaves as a donor or acceptor in the semiconducting polymer:carbon nanotube composite. In this paper, we report a direct observation via Kelvin probe force microscopy (KPFM) that single walled carbon nanotubes (SWNTs) behave as hole transporting channels in poly(3-hexylthiophene-2,5-diyl) (P3HT)/SWNT heterojunctions. By comparing the surface potential (SP) change of SWNT in dark and under illumination, we observed that electrons are blocked from SWNT while holes are transferred to SWNT. This observation can be well-explained by our proposed band alignment model of P3HT/SWNT heterojunction. The finding is further verified by hole mobility measurement using the space charge limited current (SCLC) method. SCLC results indicate that the existence of small amount of SWNT (wt 0.5%) promotes device hole mobility to around 15-fold, indicating SWNT act as hole transfer channel. Our finding of hole transporting behavior of SWNT in P3HT/SWNT blend will provide a useful guidance for enhancing the performance of polymer solar cells by carbon nanotubes.

Direct observation of feedout-related areal mass oscillations in planar plastic targets.

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Metzler, N.; Velikovich, A. L.; Karasik, M.; Serlin, V.; Pawley, C.; Mostovych, A. N.; Schmitt, A. J.; Obenschain, S. P.; Gardner, J. H.

2001-10-01

"Feedout" means the transfer of mass perturbations from the rear to the front surface of a driven target. The oscillations are expected if the perturbation wavelength λ is not large compared to 2π L_s, where Ls is the shock-compressed target thickness. We report the first direct experimental observation of areal mass oscillation associated with feedout, followed by the onset of exponential RT growth. Our experiments were performed with the Nike KrF laser at irradiation 50 TW/cm^2. The mass redistribution in the target was observed with the aid of monochromatic x-ray imaging coupled to a streak camera. We used 40 to 60 μm thick CH targets rippled on the rear side with wavelengths of either 30 or 45 μm, the ratio 2π L_s/λ thus being close to 2. Two phase reversals of mass variation predicted by the theory and simulations were consistently observed both on the original images and on the time histories of Fourier amplitudes.

Direct and simultaneous observation of ultrafast electron and hole dynamics in germanium.

PubMed

Zürch, Michael; Chang, Hung-Tzu; Borja, Lauren J; Kraus, Peter M; Cushing, Scott K; Gandman, Andrey; Kaplan, Christopher J; Oh, Myoung Hwan; Prell, James S; Prendergast, David; Pemmaraju, Chaitanya D; Neumark, Daniel M; Leone, Stephen R

2017-06-01

Understanding excited carrier dynamics in semiconductors is crucial for the development of photovoltaics and efficient photonic devices. However, overlapping spectral features in optical pump-probe spectroscopy often render assignments of separate electron and hole carrier dynamics ambiguous. Here, ultrafast electron and hole dynamics in germanium nanocrystalline thin films are directly and simultaneously observed by ultrafast transient absorption spectroscopy in the extreme ultraviolet at the germanium M 4,5 edge. We decompose the spectra into contributions of electronic state blocking and photo-induced band shifts at a carrier density of 8 × 10 20  cm -3 . Separate electron and hole relaxation times are observed as a function of hot carrier energies. A first-order electron and hole decay of ∼1 ps suggests a Shockley-Read-Hall recombination mechanism. The simultaneous observation of electrons and holes with extreme ultraviolet transient absorption spectroscopy paves the way for investigating few- to sub-femtosecond dynamics of both holes and electrons in complex semiconductor materials and across junctions.

Direct and simultaneous observation of ultrafast electron and hole dynamics in germanium

PubMed Central

Zürch, Michael; Chang, Hung-Tzu; Borja, Lauren J.; Kraus, Peter M.; Cushing, Scott K.; Gandman, Andrey; Kaplan, Christopher J.; Oh, Myoung Hwan; Prell, James S.; Prendergast, David; Pemmaraju, Chaitanya D.; Neumark, Daniel M.; Leone, Stephen R.

2017-01-01

Understanding excited carrier dynamics in semiconductors is crucial for the development of photovoltaics and efficient photonic devices. However, overlapping spectral features in optical pump-probe spectroscopy often render assignments of separate electron and hole carrier dynamics ambiguous. Here, ultrafast electron and hole dynamics in germanium nanocrystalline thin films are directly and simultaneously observed by ultrafast transient absorption spectroscopy in the extreme ultraviolet at the germanium M4,5 edge. We decompose the spectra into contributions of electronic state blocking and photo-induced band shifts at a carrier density of 8 × 1020 cm−3. Separate electron and hole relaxation times are observed as a function of hot carrier energies. A first-order electron and hole decay of ∼1 ps suggests a Shockley–Read–Hall recombination mechanism. The simultaneous observation of electrons and holes with extreme ultraviolet transient absorption spectroscopy paves the way for investigating few- to sub-femtosecond dynamics of both holes and electrons in complex semiconductor materials and across junctions. PMID:28569752

Direct Observation of Insulin Association Dynamics with Time-Resolved X-ray Scattering

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

Rimmerman, Dolev; Leshchev, Denis; Hsu, Darren J.

Biological functions frequently require protein-protein interactions that involve secondary and tertiary structural perturbation. Here we study protein-protein dissociation and reassociation dynamics in insulin, a model system for protein oligomerization. Insulin dimer dissociation into monomers was induced by a nanosecond temperature-jump (T-jump) of ~8 °C in aqueous solution, and the resulting protein and solvent dynamics were tracked by time-resolved X-ray solution scattering (TRXSS) on time scales of 10 ns to 100 ms. The protein scattering signals revealed the formation of five distinguishable transient species during the association process that deviate from simple two state kinetics. Our results show that the combinationmore » of T-jump pump coupled to TRXSS probe allows for direct tracking of structural dynamics in nonphotoactive proteins.« less

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

Photocrystallographic observation of halide-bridged intermediates in halogen photoeliminations.

PubMed

Powers, David C; Anderson, Bryce L; Hwang, Seung Jun; Powers, Tamara M; Pérez, Lisa M; Hall, Michael B; Zheng, Shao-Liang; Chen, Yu-Sheng; Nocera, Daniel G

2014-10-29

Polynuclear transition metal complexes, which frequently constitute the active sites of both biological and chemical catalysts, provide access to unique chemical transformations that are derived from metal-metal cooperation. Reductive elimination via ligand-bridged binuclear intermediates from bimetallic cores is one mechanism by which metals may cooperate during catalysis. We have established families of Rh2 complexes that participate in HX-splitting photocatalysis in which metal-metal cooperation is credited with the ability to achieve multielectron photochemical reactions in preference to single-electron transformations. Nanosecond-resolved transient absorption spectroscopy, steady-state photocrystallography, and computational modeling have allowed direct observation and characterization of Cl-bridged intermediates (intramolecular analogues of classical ligand-bridged intermediates in binuclear eliminations) in halogen elimination reactions. On the basis of these observations, a new class of Rh2 complexes, supported by CO ligands, has been prepared, allowing for the isolation and independent characterization of the proposed halide-bridged intermediates. Direct observation of halide-bridged structures establishes binuclear reductive elimination as a viable mechanism for photogenerating energetic bonds.

Direct observation of multiple rotational stacking faults coexisting in freestanding bilayer MoS2.

PubMed

Li, Zuocheng; Yan, Xingxu; Tang, Zhenkun; Huo, Ziyang; Li, Guoliang; Jiao, Liying; Liu, Li-Min; Zhang, Miao; Luo, Jun; Zhu, Jing

2017-08-16

Electronic properties of two-dimensional (2D) MoS 2 semiconductors can be modulated by introducing specific defects. One important type of defect in 2D layered materials is known as rotational stacking fault (RSF), but the coexistence of multiple RSFs with different rotational angles was not directly observed in freestanding 2D MoS 2 before. In this report, we demonstrate the coexistence of three RSFs with three different rotational angles in a freestanding bilayer MoS 2 sheet as directly observed using an aberration-corrected transmission electron microscope (TEM). Our analyses show that these RSFs originate from cracks and dislocations within the bilayer MoS 2 . First-principles calculations indicate that RSFs with different rotational angles change the electronic structures of bilayer MoS 2 and produce two new symmetries in their bandgaps and offset crystal momentums. Therefore, employing RSFs and their coexistence is a promising route in defect engineering of MoS 2 to fabricate suitable devices for electronics, optoelectronics, and energy conversion.

Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH) 2 Nanoparticle Hybrid

DOE PAGES

Tang, Yu; Pattengale, Brian A.; Ludwig, John M.; ...

2015-12-17

We report that Ni(OH) 2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH) 2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer frommore » Ru complex to Ni(OH) 2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (>>50 ns). These results not only suggest the possibility of developing Ni(OH) 2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA.« less

The influence of program acceptability on the effectiveness of public health policy: a study of directly observed therapy for tuberculosis.

PubMed Central

Heymann, S J; Sell, R; Brewer, T F

1998-01-01

OBJECTIVES: This study examined how patient acceptability influences the effectiveness of directly observed therapy for tuberculosis. METHODS: Decision and sensitivity analyses were used in assessing influences. RESULTS: If mandatory directly observed therapy discourages 6% of initial tuberculosis patients (range: 4% to 10%) from seeking care, then such therapy will be less effective than self-administered therapy. Directly observed therapy is more effective than repeated self-administered therapy for patients failing to complete initial treatment unless 32% (range: 27% to 38%) of patients avoid seeking care. CONCLUSIONS: Patient acceptability must be taken into consideration before selecting public health strategies. PMID:9518978

Gravity Waves Generated by Convection: A New Idealized Model Tool and Direct Validation with Satellite Observations

NASA Astrophysics Data System (ADS)

Alexander, M. Joan; Stephan, Claudia

2015-04-01

In climate models, gravity waves remain too poorly resolved to be directly modelled. Instead, simplified parameterizations are used to include gravity wave effects on model winds. A few climate models link some of the parameterized waves to convective sources, providing a mechanism for feedback between changes in convection and gravity wave-driven changes in circulation in the tropics and above high-latitude storms. These convective wave parameterizations are based on limited case studies with cloud-resolving models, but they are poorly constrained by observational validation, and tuning parameters have large uncertainties. Our new work distills results from complex, full-physics cloud-resolving model studies to essential variables for gravity wave generation. We use the Weather Research Forecast (WRF) model to study relationships between precipitation, latent heating/cooling and other cloud properties to the spectrum of gravity wave momentum flux above midlatitude storm systems. Results show the gravity wave spectrum is surprisingly insensitive to the representation of microphysics in WRF. This is good news for use of these models for gravity wave parameterization development since microphysical properties are a key uncertainty. We further use the full-physics cloud-resolving model as a tool to directly link observed precipitation variability to gravity wave generation. We show that waves in an idealized model forced with radar-observed precipitation can quantitatively reproduce instantaneous satellite-observed features of the gravity wave field above storms, which is a powerful validation of our understanding of waves generated by convection. The idealized model directly links observations of surface precipitation to observed waves in the stratosphere, and the simplicity of the model permits deep/large-area domains for studies of wave-mean flow interactions. This unique validated model tool permits quantitative studies of gravity wave driving of regional

Direct Observation of the Growth of Au-Pd Core-Shell Nanoparticles Using in situ Low-Dose Liquid Cell STEM imaging

DOE PAGES

Bhattarai, Nabraj; Prozorov, Tanya

2016-07-25

Bimetallic core-shell nanoparticles are widely used as catalysts in several industrial reactions, with core-shell structures permitting facile surface modification and allowing increased stability and durability, and cost-effectiveness of the catalysts. We report, for the first time, on observing the early stages of the formation of Au-Pd core-shell bimetallic nanoparticles via the seed-mediated growth in the presence of reducing agent, while employing the low-dose scanning transmission electron microscopy imaging with the fluid cell in situ. Use of the continuous flow in situ fluid cell platform allows for delivery of reagent solutions and generation of near-native reaction environment in the reaction chamber,more » and permits direct visualization of the early stages of formation of Au-Pd core-shell structures at low dose rate (0.1 e -/(Å 2s)) in the presence of ascorbic acid. No core-shell structures were detected in the absence of reducing agent at the electron dose of 32.6 e -/Å 2. While the core-shell structures formed in situ under the low-dose imaging closely resemble those obtained in solution synthesis, the reaction kinetics in the fluid cell is affected by the radiolysis of liquid reagents induced by electron beam, altering the rate-determining reaction steps. The enhanced reduction of Pd ions leads to initial rapid growth of the nascent Pd shell along the <111> direction at the Au interface, followed by a slower rearrangement of the outer Pd layer. The latter becomes the rate-determining step in the in situ reaction and appears to follow the oriented attachment-like movement to yield a remodeled, compact and stable Au-Pd core-shell nanostructure. Our findings highlight the differences between the two reaction pathways and aid in understanding the mechanism of formation of the core-shell nanostructure in situ.« less

Social communication with virtual agents: The effects of body and gaze direction on attention and emotional responding in human observers.

PubMed

Marschner, Linda; Pannasch, Sebastian; Schulz, Johannes; Graupner, Sven-Thomas

2015-08-01

In social communication, the gaze direction of other persons provides important information to perceive and interpret their emotional response. Previous research investigated the influence of gaze by manipulating mutual eye contact. Therefore, gaze and body direction have been changed as a whole, resulting in only congruent gaze and body directions (averted or directed) of another person. Here, we aimed to disentangle these effects by using short animated sequences of virtual agents posing with either direct or averted body or gaze. Attention allocation by means of eye movements, facial muscle response, and emotional experience to agents of different gender and facial expressions were investigated. Eye movement data revealed longer fixation durations, i.e., a stronger allocation of attention, when gaze and body direction were not congruent with each other or when both were directed towards the observer. This suggests that direct interaction as well as incongruous signals increase the demands of attentional resources in the observer. For the facial muscle response, only the reaction of muscle zygomaticus major revealed an effect of body direction, expressed by stronger activity in response to happy expressions for direct compared to averted gaze when the virtual character's body was directed towards the observer. Finally, body direction also influenced the emotional experience ratings towards happy expressions. While earlier findings suggested that mutual eye contact is the main source for increased emotional responding and attentional allocation, the present results indicate that direction of the virtual agent's body and head also plays a minor but significant role. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct Observations of ULF and Whistler-Mode Chorus Modulation of 500eV EDI Electrons by MMS

NASA Astrophysics Data System (ADS)

Paulson, K. W.; Argall, M. R.; Ahmadi, N.; Torbert, R. B.; Le Contel, O.; Ergun, R.; Khotyaintsev, Y. V.; Strangeway, R. J.; Magnes, W.; Russell, C. T.

2016-12-01

We present here direct observations of chorus-wave modulated field-aligned 500 eV electrons using the Electron Drift Instrument (EDI) on board the Magnetospheric Multiscale mission. These periods of wave activity were additionally observed to be modulated by Pc5-frequency magnetic perturbations, some of which have been identified as drifting mirror-mode structures. The spacecraft encountered these mirror-mode structures just inside of the duskside magnetopause. Using the high sampling rate provided by EDI in burst sampling mode, we are able to observe the individual count fluctuations of field-aligned electrons in this region up to 512 Hz. We use the multiple look directions of EDI to generate both pitch angle and gyrophase plots of the fluctuating counts. Our observations often show unidirectional flow of these modulated electrons along the background field, and in some cases demonstrate gyrophase bunching in the wave region.

Direct observation of MoO 2 crystal growth from amorphous MoO 3 film

NASA Astrophysics Data System (ADS)

Nina, Kenji; Kimura, Yuki; Yokoyama, Kaori; Kido, Osamu; Binyo, Gong; Kaito, Chihiro

2008-08-01

The formation process of MoO 2 crystal from amorphous MoO 3 film has been imaged by in situ observation with a transmission electron microscope. Selective growth of flower-shaped MoO 2 crystals by heating above 673 K in vacuum was directly observed. Since the MoO 2 crystal has metallic conductivity of the order of indium oxide film containing tin (ITO film), the thin film growth of the MoO 2 phase has been discussed on the basis of a new substitute for ITO film.

Direct Observation of the Strange b Baryon {xi}{sub b}{sup -}

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

Abazov, V. M.; Alexeev, G. D.; Kalinin, A. M.

We report the first direct observation of the strange b baryon {xi}{sub b}{sup -}({xi}{sub b}{sup +}). We reconstruct the decay {xi}{sub b}{sup -}{yields}J/{psi}{xi}{sup -}, with J/{psi}{yields}{mu}{sup +}{mu}{sup -}, and {xi}{sup -}{yields}{lambda}{pi}{sup -}{yields}p{pi}{sup -}{pi}{sup -} in pp collisions at {radical}(s)=1.96 TeV. Using 1.3 fb{sup -1} of data collected by the D0 detector, we observe 15.2{+-}4.4(stat){sub -0.4}{sup +1.9}(syst) {xi}{sub b}{sup -} candidates at a mass of 5.774{+-}0.011(stat){+-}0.015(syst) GeV. The significance of the observed signal is 5.5{sigma}, equivalent to a probability of 3.3x10{sup -8} of it arising from a background fluctuation. Normalizing to the decay {lambda}{sub b}{yields}J/{psi}{lambda}, we measure the relative rate ({sigma}({xi}{submore » b}{sup -})xB({xi}{sub b}{sup -}{yields}J/{psi}{xi}{sup -})/{sigma}({lambda}{sub b})xB({lambda}{sub b}{yields}J/{psi}{lambda}))=0.28{+-}0.09(stat){sub -0.08}{sup +0.09}(syst)« less

Direct three-dimensional observation of the microstructure and chemistry of C{sub 3}S hydration

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

Hu, Qinang; Aboustait, Mohammed; Kim, Taehwan

Disagreements about the mechanisms of cement hydration remain despite the fact that portland cement has been studied extensively for over 100 years. One reason for this is that direct observation of the change in microstructure and chemistry are challenging for many experimental techniques. This paper presents results from synchrotron nano X-ray tomography and fluorescence imaging. The data show unprecedented direct observations of small collections of C{sub 3}S particles before and after different periods of hydration in 15 mmol/L lime solution. X-ray absorption contrast is used to make three dimensional maps of the changes of these materials with time. The chemicalmore » compositions of hydration products are then identified with X-ray fluorescence mapping and scanning electron microscopy. These experiments are used to provide insight into the rate and morphology of the microstructure formation.« less

Direct Observation of Clinical Skills Feedback Scale: Development and Validity Evidence.

PubMed

Halman, Samantha; Dudek, Nancy; Wood, Timothy; Pugh, Debra; Touchie, Claire; McAleer, Sean; Humphrey-Murto, Susan

2016-01-01

Construct: This article describes the development and validity evidence behind a new rating scale to assess feedback quality in the clinical workplace. Competency-based medical education has mandated a shift to learner-centeredness, authentic observation, and frequent formative assessments with a focus on the delivery of effective feedback. Because feedback has been shown to be of variable quality and effectiveness, an assessment of feedback quality in the workplace is important to ensure we are providing trainees with optimal learning opportunities. The purposes of this project were to develop a rating scale for the quality of verbal feedback in the workplace (the Direct Observation of Clinical Skills Feedback Scale [DOCS-FBS]) and to gather validity evidence for its use. Two panels of experts (local and national) took part in a nominal group technique to identify features of high-quality feedback. Through multiple iterations and review, 9 features were developed into the DOCS-FBS. Four rater types (residents n = 21, medical students n = 8, faculty n = 12, and educators n = 12) used the DOCS-FBS to rate videotaped feedback encounters of variable quality. The psychometric properties of the scale were determined using a generalizability analysis. Participants also completed a survey to gather data on a 5-point Likert scale to inform the ease of use, clarity, knowledge acquisition, and acceptability of the scale. Mean video ratings ranged from 1.38 to 2.96 out of 3 and followed the intended pattern suggesting that the tool allowed raters to distinguish between examples of higher and lower quality feedback. There were no significant differences between rater type (range = 2.36-2.49), suggesting that all groups of raters used the tool in the same way. The generalizability coefficients for the scale ranged from 0.97 to 0.99. Item-total correlations were all above 0.80, suggesting some redundancy in items. Participants found the scale easy to use (M = 4.31/5) and clear

In-situ temperature field measurements and direct observation of crystal/melt at vertical Bridgman growth of lead chloride under stationary and dynamic arrangement

NASA Astrophysics Data System (ADS)

Král, Robert; Nitsch, Karel

2015-10-01

Influence of growth conditions, i.e. temperature gradient in the furnace and the pulling rate, on the position and the shape of the crystal/melt interface during vertical Bridgman growth was studied. The position and the shape of the crystal/melt interface are a key factor for describing the final quality of growing crystal. Following two methods for characterization of its position and shape were used: (i) direct observation and (ii) direct temperature field measurement during simulated vertical Bridgman growth. As a model compound a lead chloride is used. Three different ampoule positions in two different temperature gradients in the furnace and two experimental arrangements - stationary (0 mm/h pulling rate) and dynamic (3 mm/h pulling rate) were analyzed. Obtained temperature data were projected as 2D planar cut under radial symmetry and denoted as isolevels. Their further conversion by linear approximation into isotherms allowed detail analysis of heat conditions in the system during simulated growth by comparison of isotherms 500 °C (m.p. of lead chloride) at different growth conditions.

Nature of Fluctuations on Directional Discontinuities Inside a Solar Ejection: Wind and IMP 8 Observations

NASA Technical Reports Server (NTRS)

Vasquez, Bernard J.; Farrugia, Charles J.; Markovskii, Sergei A.; Hollweg, Joseph V.; Richardson, Ian G.; Ogilvie, Keith W.; Lepping, Ronald P.; Lin, Robert P.; Larson, Davin; White, Nicholas E. (Technical Monitor)

2001-01-01

A solar ejection passed the Wind spacecraft between December 23 and 26, 1996. On closer examination, we find a sequence of ejecta material, as identified by abnormally low proton temperatures, separated by plasmas with typical solar wind temperatures at 1 AU. Large and abrupt changes in field and plasma properties occurred near the separation boundaries of these regions. At the one boundary we examine here, a series of directional discontinuities was observed. We argue that Alfvenic fluctuations in the immediate vicinity of these discontinuities distort minimum variance normals, introducing uncertainty into the identification of the discontinuities as either rotational or tangential. Carrying out a series of tests on plasma and field data including minimum variance, velocity and magnetic field correlations, and jump conditions, we conclude that the discontinuities are tangential. Furthermore, we find waves superposed on these tangential discontinuities (TDs). The presence of discontinuities allows the existence of both surface waves and ducted body waves. Both probably form in the solar atmosphere where many transverse nonuniformities exist and where theoretically they have been expected. We add to prior speculation that waves on discontinuities may in fact be a common occurrence. In the solar wind, these waves can attain large amplitudes and low frequencies. We argue that such waves can generate dynamical changes at TDs through advection or forced reconnection. The dynamics might so extensively alter the internal structure that the discontinuity would no longer be identified as tangential. Such processes could help explain why the occurrence frequency of TDs observed throughout the solar wind falls off with increasing heliocentric distance. The presence of waves may also alter the nature of the interactions of TDs with the Earth's bow shock in so-called hot flow anomalies.

Evaluation of the Maximum Allowable Cost Program

PubMed Central

Lee, A. James; Hefner, Dennis; Dobson, Allen; Hardy, Ralph

1983-01-01

This article summarizes an evaluation of the Maximum Allowable Cost (MAC)-Estimated Acquisition Cost (EAC) program, the Federal Government's cost-containment program for prescription drugs.1 The MAC-EAC regulations which became effective on August 26, 1976, have four major components: (1) Maximum Allowable Cost reimbursement limits for selected multisource or generically available drugs; (2) Estimated Acquisition Cost reimbursement limits for all drugs; (3) “usual and customary” reimbursement limits for all drugs; and (4) a directive that professional fee studies be performed by each State. The study examines the benefits and costs of the MAC reimbursement limits for 15 dosage forms of five multisource drugs and EAC reimbursement limits for all drugs for five selected States as of 1979. PMID:10309857

A direct observation method for auditing large urban centers using stratified sampling, mobile GIS technology and virtual environments.

PubMed

Lafontaine, Sean J V; Sawada, M; Kristjansson, Elizabeth

2017-02-16

With the expansion and growth of research on neighbourhood characteristics, there is an increased need for direct observational field audits. Herein, we introduce a novel direct observational audit method and systematic social observation instrument (SSOI) for efficiently assessing neighbourhood aesthetics over large urban areas. Our audit method uses spatial random sampling stratified by residential zoning and incorporates both mobile geographic information systems technology and virtual environments. The reliability of our method was tested in two ways: first, in 15 Ottawa neighbourhoods, we compared results at audited locations over two subsequent years, and second; we audited every residential block (167 blocks) in one neighbourhood and compared the distribution of SSOI aesthetics index scores with results from the randomly audited locations. Finally, we present interrater reliability and consistency results on all observed items. The observed neighbourhood average aesthetics index score estimated from four or five stratified random audit locations is sufficient to characterize the average neighbourhood aesthetics. The SSOI was internally consistent and demonstrated good to excellent interrater reliability. At the neighbourhood level, aesthetics is positively related to SES and physical activity and negatively correlated with BMI. The proposed approach to direct neighbourhood auditing performs sufficiently and has the advantage of financial and temporal efficiency when auditing a large city.

Trehalose glycopolymer resists allow direct writing of protein patterns by electron-beam lithography

NASA Astrophysics Data System (ADS)

Bat, Erhan; Lee, Juneyoung; Lau, Uland Y.; Maynard, Heather D.

2015-03-01

Direct-write patterning of multiple proteins on surfaces is of tremendous interest for a myriad of applications. Precise arrangement of different proteins at increasingly smaller dimensions is a fundamental challenge to apply the materials in tissue engineering, diagnostics, proteomics and biosensors. Herein, we present a new resist that protects proteins during electron-beam exposure and its application in direct-write patterning of multiple proteins. Polymers with pendant trehalose units are shown to effectively crosslink to surfaces as negative resists, while at the same time providing stabilization to proteins during the vacuum and electron-beam irradiation steps. In this manner, arbitrary patterns of several different classes of proteins such as enzymes, growth factors and immunoglobulins are realized. Utilizing the high-precision alignment capability of electron-beam lithography, surfaces with complex patterns of multiple proteins are successfully generated at the micrometre and nanometre scale without requiring cleanroom conditions.

Direct observation of keyhole characteristics in deep penetration laser welding with a 10 kW fiber laser.

PubMed

Zhang, Mingjun; Chen, Genyu; Zhou, Yu; Li, Shichun

2013-08-26

Keyhole formation is a prerequisite for deep penetration laser welding. Understanding of the keyhole dynamics is essential to improve the stability of the keyhole. Direct observation of the keyhole during deep penetration laser welding of a modified "sandwich" specimen with a 10 kW fiber laser is presented. A distinct keyhole wall and liquid motion along the wall are observed directly for the first time. The moving liquid "shelf" on the front keyhole wall and the accompanying hydrodynamic and vapor phenomena are observed simultaneously. Micro-droplets torn off the keyhole wall and the resultant bursts of vapor are also visualized. The hydrodynamics on the keyhole wall has a dominant effect on the weld defects. The emission spectrum inside the keyhole is captured accurately using a spectrometer to calculate the characteristics of the keyhole plasma plume.

Considering Systematic Direct Observation after a Century of Research--Commentary on the Special Issue

ERIC Educational Resources Information Center

Stichter, Janine P.; Riley-Tillman, T. Chris

2014-01-01

Systematic Direct Observation (SDO) has played a pivotal role in the field of Emotional and/or Behavioral Disorders (EBD) since its inception as a key part of understanding more about the behaviors, contexts that impact them, and the effective supports necessary for this population. This methodology is an ongoing charge for everyone. The authors…

In Situ Observation of Directed Nanoparticle Aggregation During the Synthesis of Ordered Nanoporous Metal in Soft Templates

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

Parent, Lucas R.; Robinson, David B.; Cappillino, Patrick J.

2014-02-11

The prevalent approach to developing new nanomaterials is a trial and error process of iteratively altering synthesis procedures and then characterizing the resulting nanostructures. This is fundamentally limited in that the growth processes that occur during synthesis can only be inferred from the final synthetic structure. Directly observing real-time nanomaterial growth provides unprecedented insight into the relationship between synthesis conditions and product evolution, and facilitates a mechanistic approach to nanomaterial development. Here we use in situ liquid stage scanning transmission electron microscopy to observe the growth of mesoporous palladium in a solvated block copolymer (BCP) template under various synthesis conditions,more » and ultimately determine a refined synthesis procedure that yields ordered pores. We find that at low organic solvent (tetrahydrofuran, THF) content, the BCP assembles into a rigid, cylindrical micelle array with a high degree of short-range order, but poor long-range order. Upon slowing the THF evaporation rate using a solvent-vapor anneal step, the long-range order is greatly improved. The electron beam induces nucleation of small particles in the aqueous phase around the micelles. The small particles then flocculate and grow into denser structures that surround the micelles, forming an ordered mesoporous structure. The microscope observations revealed that template disorder can be addressed prior to reaction, and is not invariably induced by the growth process itself, allowing us to more quickly optimize the synthetic method. This work was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy under contract DE-AC05-76RL01830. This

48 CFR 52.216-7 - Allowable Cost and Payment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... last disclosure of internal audit reports to the Government. (J) Annual internal audit plan of...-contract cost allowability limitations, and billing limitations. (v) The Contractor shall update the billings on all contracts to reflect the final settled rates and update the schedule of cumulative direct...

7 CFR 3560.202 - Establishing rents and utility allowances.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Establishing rents and utility allowances. 3560.202 Section 3560.202 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Rents § 3560.202...

42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel. Such...

42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel. Such...

42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel. Such...

42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel. Such...

42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel. Such...

Direct Observation of a Majorana Quasiparticle Heat Capacity in 3He

NASA Astrophysics Data System (ADS)

Bunkov, Y. M.

2014-04-01

The Majorana fermion, which acts as its own antiparticle, was suggested by Majorana in 1937 (Nuovo Cimento 14:171). While no stable particle with Majorana properties has yet been observed, Majorana quasiparticles (QP) may exist at the boundaries of topological insulators. Here we report the preliminary results of direct observation of Majorana QPs by a precise measurements of superfluid 3He heat capacity. The bulk superfluid 3He heat capacity falls exponentially with cooling at the temperatures significantly below the energy gap. Owing to the zero energy gap mode the Majorana heat capacity falls in a power law. The Majorana heat capacity can be larger than bulk one at some temperature, which depends on surface to volume ratio of the experimental cell. Some times ago we developed the Dark matter particles detector (DMD) on a basis of superfluid 3He which is working at the frontier of extremely low temperatures (Winkelmann et al., Nucl. Instrum. Meth. A 559:384-386, 2006). Here we report the observation of zero gap mode of Majorana, follows from the new analyses of DMD heat capacity, published early. We have found a 10 % deviation from the bulk superfluid 3He heat capacity at the temperature of 135 μK. This deviation corresponds well to the theoretical value for Majorana heat capacity at such low temperature. (Note, there were no fitting parameters).

Directional Statistics for Polarization Observations of Individual Pulses from Radio Pulsars

NASA Astrophysics Data System (ADS)

McKinnon, M. M.

2010-10-01

Radio polarimetry is a three-dimensional statistical problem. The three-dimensional aspect of the problem arises from the Stokes parameters Q, U, and V, which completely describe the polarization of electromagnetic radiation and conceptually define the orientation of a polarization vector in the Poincaré sphere. The statistical aspect of the problem arises from the random fluctuations in the source-intrinsic polarization and the instrumental noise. A simple model for the polarization of pulsar radio emission has been used to derive the three-dimensional statistics of radio polarimetry. The model is based upon the proposition that the observed polarization is due to the incoherent superposition of two, highly polarized, orthogonal modes. The directional statistics derived from the model follow the Bingham-Mardia and Fisher family of distributions. The model assumptions are supported by the qualitative agreement between the statistics derived from it and those measured with polarization observations of the individual pulses from pulsars. The orthogonal modes are thought to be the natural modes of radio wave propagation in the pulsar magnetosphere. The intensities of the modes become statistically independent when generalized Faraday rotation (GFR) in the magnetosphere causes the difference in their phases to be large. A stochastic version of GFR occurs when fluctuations in the phase difference are also large, and may be responsible for the more complicated polarization patterns observed in pulsar radio emission.

40 CFR 73.72 - Direct sales.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

40 CFR 73.72 - Direct sales.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

40 CFR 73.72 - Direct sales.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

40 CFR 73.72 - Direct sales.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

40 CFR 73.72 - Direct sales.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

Direct Observations of the Charge States of Low Energy Solar Particles

NASA Technical Reports Server (NTRS)

Gloeckler, G.; Fan, C. Y.; Hovestadt, D.

1973-01-01

The charge states of carbon and oxygen of solar origin were measured directly in interplanetary space. At 100 keV per nucleon the C(+5)/C(+6) and O(+7)/O(+8) ratios are 1.8 and 1.6 respectively. It was found that the abundance ratios of low energy heavy nuclei to He is significantly larger than corresponding photospheric values: the enhancement of O/He is 35 and both Si/He and Fe/He are overabundant by a factor of 100. To explain these observations a mechanism is proposed which first preferentially accelerates heavy ions and is followed by either storage of these ions in the coronal regions or strong adiabatic deceleration.

Direct observations of the charge states of low energy solar particles

NASA Technical Reports Server (NTRS)

Gloeckler, G.; Fan, C. Y.; Hovestadt, D.

1974-01-01

The charge states of carbon and oxygen of solar origin have been measured directly in interplanetary space. At 100 keV per nucleon the C(+5)/C(+6) and O(+7)/O(+8) ratios are 1.8 and 1.6, respectively. Abundance ratios of low energy heavy nuclei to He are found which are significantly larger than the corresponding photospheric values. The enhancement of O/He is 35, and both Si/He and Fe/He are overabundant by a factor of 100. To explain these observations a mechanism is proposed which first preferentially accelerates heavy ions and is followed by either storage of these ions in the coronal regions or strong adiabatic deceleration.

Direct observation of TALE protein dynamics reveals a two-state search mechanism.

PubMed

Cuculis, Luke; Abil, Zhanar; Zhao, Huimin; Schroeder, Charles M

2015-06-01

Transcription activator-like effector (TALE) proteins are a class of programmable DNA-binding proteins for which the fundamental mechanisms governing the search process are not fully understood. Here we use single-molecule techniques to directly observe TALE search dynamics along DNA templates. We find that TALE proteins are capable of rapid diffusion along DNA using a combination of sliding and hopping behaviour, which suggests that the TALE search process is governed in part by facilitated diffusion. We also observe that TALE proteins exhibit two distinct modes of action during the search process-a search state and a recognition state-facilitated by different subdomains in monomeric TALE proteins. Using TALE truncation mutants, we further demonstrate that the N-terminal region of TALEs is required for the initial non-specific binding and subsequent rapid search along DNA, whereas the central repeat domain is required for transitioning into the site-specific recognition state.

Interplanetary and Interstellar Dust Observed by the Wind/WAVES Electric Field Instrument

NASA Technical Reports Server (NTRS)

Malaspina, David; Horanyi, M.; Zaslavsky, A.; Goetz, K.; Wilson, L. B., III; Kersten, K.

2014-01-01

Observations of hypervelocity dust particles impacting the Wind spacecraft are reported here for the first time using data from the WindWAVES electric field instrument. A unique combination of rotating spacecraft, amplitude-triggered high-cadence waveform collection, and electric field antenna configuration allow the first direct determination of dust impact direction by any spacecraft using electric field data. Dust flux and impact direction data indicate that the observed dust is approximately micron-sized with both interplanetary and interstellar populations. Nanometer radius dust is not detected by Wind during times when nanometer dust is observed on the STEREO spacecraft and both spacecraft are in close proximity. Determined impact directions suggest that interplanetary dust detected by electric field instruments at 1 AU is dominated by particles on bound trajectories crossing Earths orbit, rather than dust with hyperbolic orbits.

Intense deformation field at oceanic front inferred from directional sea surface roughness observations

NASA Astrophysics Data System (ADS)

Rascle, Nicolas; Molemaker, Jeroen; Marié, Louis; Nouguier, Frédéric; Chapron, Bertrand; Lund, Björn; Mouche, Alexis

2017-06-01

Fine-scale current gradients at the ocean surface can be observed by sea surface roughness. More specifically, directional surface roughness anomalies are related to the different horizontal current gradient components. This paper reports results from a dedicated experiment during the Lagrangian Submesoscale Experiment (LASER) drifter deployment. A very sharp front, 50 m wide, is detected simultaneously in drifter trajectories, sea surface temperature, and sea surface roughness. A new observational method is applied, using Sun glitter reflections during multiple airplane passes to reconstruct the multiangle roughness anomaly. This multiangle anomaly is consistent with wave-current interactions over a front, including both cross-front convergence and along-front shear with cyclonic vorticity. Qualitatively, results agree with drifters and X-band radar observations. Quantitatively, the sharpness of roughness anomaly suggests intense current gradients, 0.3 m s-1 over the 50 m wide front. This work opens new perspectives for monitoring intense oceanic fronts using drones or satellite constellations.

Department of Defense Environmental Cleanup Cost Allowability Policy.

DTIC Science & Technology

1994-12-01

The environment is directly affected by the industrial requirements and manufacturing processes necessary to provide those goods and services. As...and the industrial base. To begin the process , DCMC initiated the Environmental Initiatives Task Force Pilot Cost Allowance Program at five locations...policy covering environmental cleanup costs. Information will be provided to assist in the decision making process regarding the factors affecting the

The cost-effectiveness of directly observed highly-active antiretroviral therapy in the third trimester in HIV-infected pregnant women.

PubMed

McCabe, Caitlin J; Goldie, Sue J; Fisman, David N

2010-04-13

In HIV-infected pregnant women, viral suppression prevents mother-to-child HIV transmission. Directly observed highly-active antiretroviral therapy (HAART) enhances virological suppression, and could prevent transmission. Our objective was to project the effectiveness and cost-effectiveness of directly observed administration of antiretroviral drugs in pregnancy. A mathematical model was created to simulate cohorts of one million asymptomatic HIV-infected pregnant women on HAART, with women randomly assigned self-administered or directly observed antiretroviral therapy (DOT), or no HAART, in a series of Monte Carlo simulations. Our primary outcome was the quality-adjusted life expectancy in years (QALY) of infants born to HIV-infected women, with the rates of Caesarean section and HIV-transmission after DOT use as intermediate outcomes. Both self-administered HAART and DOT were associated with decreased costs and increased life-expectancy relative to no HAART. The use of DOT was associated with a relative risk of HIV transmission of 0.39 relative to conventional HAART; was highly cost-effective in the cohort as a whole (cost-utility ratio $14,233 per QALY); and was cost-saving in women whose viral loads on self-administered HAART would have exceeded 1000 copies/ml. Results were stable in wide-ranging sensitivity analyses, with directly observed therapy cost-saving or highly cost-effective in almost all cases. Based on the best available data, programs that optimize adherence to HAART through direct observation in pregnancy have the potential to diminish mother-to-child HIV transmission in a highly cost-effective manner. Targeted use of DOT in pregnant women with high viral loads, who could otherwise receive self-administered HAART would be a cost-saving intervention. These projections should be tested with randomized clinical trials.

Standardizing the Pre-Licensure Supervision Process: A Commentary on Advocating for Direct Observation of Skills

ERIC Educational Resources Information Center

Gray, Neal D.; Erickson, Paul

2013-01-01

The present paper advocates for standardized regulations and laws for supervision of pre-licensed counselors in the United States, particularly for direct observation of clinical skills. A review of regulations by the American Counseling Association (ACA) Office of Professional Affairs (2012) reveals that only two states (Arizona and North…

Cloud-edge mixing: Direct numerical simulation and observations in Indian Monsoon clouds

NASA Astrophysics Data System (ADS)

Kumar, Bipin; Bera, Sudarsan; Prabha, Thara V.; Grabowski, Wojceich W.

2017-03-01

A direct numerical simulation (DNS) with the decaying turbulence setup has been carried out to study cloud-edge mixing and its impact on the droplet size distribution (DSD) applying thermodynamic conditions observed in monsoon convective clouds over Indian subcontinent during the Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX). Evaporation at the cloud-edges initiates mixing at small scale and gradually introduces larger-scale fluctuations of the temperature, moisture, and vertical velocity due to droplet evaporation. Our focus is on early evolution of simulated fields that show intriguing similarities to the CAIPEEX cloud observations. A strong dilution at the cloud edge, accompanied by significant spatial variations of the droplet concentration, mean radius, and spectral width, are found in both the DNS and in observations. In DNS, fluctuations of the mean radius and spectral width come from the impact of small-scale turbulence on the motion and evaporation of inertial droplets. These fluctuations decrease with the increase of the volume over which DNS data are averaged, as one might expect. In cloud observations, these fluctuations also come from other processes, such as entrainment/mixing below the observation level, secondary CCN activation, or variations of CCN activation at the cloud base. Despite large differences in the spatial and temporal scales, the mixing diagram often used in entrainment/mixing studies with aircraft data is remarkably similar for both DNS and cloud observations. We argue that the similarity questions applicability of heuristic ideas based on mixing between two air parcels (that the mixing diagram is designed to properly represent) to the evolution of microphysical properties during turbulent mixing between a cloud and its environment.

A multimethod investigation including direct observation of 3751 patient visits to 120 dental offices

PubMed Central

Wotman, Stephen; Demko, Catherine A; Victoroff, Kristin; Sudano, Joseph J; Lalumandier, James A

2010-01-01

This report defines verbal interactions between practitioners and patients as core activities of dental practice. Trained teams spent four days in 120 Ohio dental practices observing 3751 patient encounters with dentists and hygienists. Direct observation of practice characteristics, procedures performed, and how procedure and nonprocedure time was utilized during patient visits was recorded using a modified Davis Observation Code that classified patient contact time into 24 behavioral categories. Dentist, hygienist, and patient characteristics were gathered by questionnaire. The most common nonprocedure behaviors observed for dentists were chatting, evaluation feedback, history taking, and answering patient questions. Hygienists added preventive counseling. We distinguish between preventive procedures and counseling in actual dental offices that are members of a practice-based research network. Almost a third of the dentist’s and half of the hygienist’s patient contact time is utilized for nonprocedure behaviors during patient encounters. These interactions may be linked to patient and practitioner satisfaction and effectiveness of self-care instruction. PMID:23662080

The FluxCompensator: Making Radiative Transfer Models of Hydrodynamical Simulations Directly Comparable to Real Observations

NASA Astrophysics Data System (ADS)

Koepferl, Christine M.; Robitaille, Thomas P.

2017-11-01

When modeling astronomical objects throughout the universe, it is important to correctly treat the limitations of the data, for instance finite resolution and sensitivity. In order to simulate these effects, and to make radiative transfer models directly comparable to real observations, we have developed an open-source Python package called the FluxCompensator that enables the post-processing of the output of 3D Monte Carlo radiative transfer codes, such as Hyperion. With the FluxCompensator, realistic synthetic observations can be generated by modeling the effects of convolution with arbitrary point-spread functions, transmission curves, finite pixel resolution, noise, and reddening. Pipelines can be applied to compute synthetic observations that simulate observatories, such as the Spitzer Space Telescope or the Herschel Space Observatory. Additionally, this tool can read in existing observations (e.g., FITS format) and use the same settings for the synthetic observations. In this paper, we describe the package as well as present examples of such synthetic observations.

The FluxCompensator: Making Radiative Transfer Models of Hydrodynamical Simulations Directly Comparable to Real Observations

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

Koepferl, Christine M.; Robitaille, Thomas P., E-mail: koepferl@usm.lmu.de

When modeling astronomical objects throughout the universe, it is important to correctly treat the limitations of the data, for instance finite resolution and sensitivity. In order to simulate these effects, and to make radiative transfer models directly comparable to real observations, we have developed an open-source Python package called the FluxCompensator that enables the post-processing of the output of 3D Monte Carlo radiative transfer codes, such as Hyperion. With the FluxCompensator, realistic synthetic observations can be generated by modeling the effects of convolution with arbitrary point-spread functions, transmission curves, finite pixel resolution, noise, and reddening. Pipelines can be applied tomore » compute synthetic observations that simulate observatories, such as the Spitzer Space Telescope or the Herschel Space Observatory . Additionally, this tool can read in existing observations (e.g., FITS format) and use the same settings for the synthetic observations. In this paper, we describe the package as well as present examples of such synthetic observations.« less

Detecting frontal ablation processes from direct observations of submarine terminus morphology

NASA Astrophysics Data System (ADS)

Fried, M.; Carroll, D.; Catania, G. A.; Sutherland, D. A.; Stearns, L. A.; Bartholomaus, T. C.; Shroyer, E.; Nash, J. D.

2017-12-01

Tidewater glacier termini couple glacier and ocean systems. Subglacial discharge emerging from the terminus produces buoyant plumes that modulate submarine melting, calving, fjord circulation and, in turn, changes in ice dynamics from back-stress perturbations. However, the absence of critical observational data at the ice-ocean interface limits plume and, by extension, melt models from incorporating realistic submarine terminus face morphologies and assessing their impact on terminus behavior at tidewater glaciers. Here we present a comprehensive inventory and characterization of submarine terminus face shapes from a side-looking, multibeam echo sounding campaign across Kangerdlugssuaq Sermerssua glacier, central-west Greenland. We combine these observations with in-situ measurements of ocean stratification and remotely sensed subglacial discharge, terminus positions, ice velocity, and ice surface datasets to infer the spectrum of processes sculpting the submarine terminus face. Subglacial discharge outlet locations are confirmed through observations of sediment plumes, localized melt-driven undercutting of the terminus face, and bathymetry of the adjacent seafloor. From our analysis, we differentiate terminus morphologies resulting from submarine melt and calving and assess the contribution of each process to the net frontal ablation budget. Finally, we constrain a plume model using direct observations of the submarine terminus face and conduit geometry. Plume model simulations demonstrate that the majority of discharge outlets are fed by small discharge fluxes, suggestive of a distributed subglacial hydrologic system. Outlets with the largest, concentrated discharge fluxes are morphologically unique and strongly control seasonal terminus position. At these locations, we show that the spatiotemporal pattern of terminus retreat is well correlated with time periods when local melt rate exceeds ice velocity.

Direct observation of interfacial Au atoms on TiO₂ in three dimensions.

PubMed

Gao, Wenpei; Sivaramakrishnan, Shankar; Wen, Jianguo; Zuo, Jian-Min

2015-04-08

Interfacial atoms, which result from interactions between the metal nanoparticles and support, have a large impact on the physical and chemical properties of nanoparticles. However, they are difficult to observe; the lack of knowledge has been a major obstacle toward unraveling their role in chemical transformations. Here we report conclusive evidence of interfacial Au atoms formed on the rutile (TiO2) (110) surfaces by activation using high-temperature (∼500 °C) annealing in air. Three-dimensional imaging was performed using depth-sectioning enabled by aberration-corrected scanning transmission electron microscopy. Results show that the interface between Au nanocrystals and TiO2 (110) surfaces consists of a single atomic layer with Au atoms embedded inside Ti-O. The number of interfacial Au atoms is estimated from ∼1-8 in an interfacial atomic column. Direct impact of interfacial Au atoms is observed on an enhanced Au-TiO2 interaction and the reduction of surface TiO2; both are critical to Au catalysis.

Direct observation of TALE protein dynamics reveals a two-state search mechanism

PubMed Central

Cuculis, Luke; Abil, Zhanar; Zhao, Huimin; Schroeder, Charles M.

2015-01-01

Transcription activator-like effector (TALE) proteins are a class of programmable DNA-binding proteins for which the fundamental mechanisms governing the search process are not fully understood. Here we use single-molecule techniques to directly observe TALE search dynamics along DNA templates. We find that TALE proteins are capable of rapid diffusion along DNA using a combination of sliding and hopping behaviour, which suggests that the TALE search process is governed in part by facilitated diffusion. We also observe that TALE proteins exhibit two distinct modes of action during the search process—a search state and a recognition state—facilitated by different subdomains in monomeric TALE proteins. Using TALE truncation mutants, we further demonstrate that the N-terminal region of TALEs is required for the initial non-specific binding and subsequent rapid search along DNA, whereas the central repeat domain is required for transitioning into the site-specific recognition state. PMID:26027871

Multi-GNSS high-rate RTK, PPP and novel direct phase observation processing method: application to precise dynamic displacement detection

NASA Astrophysics Data System (ADS)

Paziewski, Jacek; Sieradzki, Rafal; Baryla, Radoslaw

2018-03-01

This paper provides the methodology and performance assessment of multi-GNSS signal processing for the detection of small-scale high-rate dynamic displacements. For this purpose, we used methods of relative (RTK) and absolute positioning (PPP), and a novel direct signal processing approach. The first two methods are recognized as providing accurate information on position in many navigation and surveying applications. The latter is an innovative method for dynamic displacement determination with the use of GNSS phase signal processing. This method is based on the developed functional model with parametrized epoch-wise topocentric relative coordinates derived from filtered GNSS observations. Current regular kinematic PPP positioning, as well as medium/long range RTK, may not offer coordinate estimates with subcentimeter precision. Thus, extended processing strategies of absolute and relative GNSS positioning have been developed and applied for displacement detection. The study also aimed to comparatively analyze the developed methods as well as to analyze the impact of combined GPS and BDS processing and the dependence of the results of the relative methods on the baseline length. All the methods were implemented with in-house developed software allowing for high-rate precise GNSS positioning and signal processing. The phase and pseudorange observations collected with a rate of 50 Hz during the field test served as the experiment’s data set. The displacements at the rover station were triggered in the horizontal plane using a device which was designed and constructed to ensure a periodic motion of GNSS antenna with an amplitude of ~3 cm and a frequency of ~4.5 Hz. Finally, a medium range RTK, PPP, and direct phase observation processing method demonstrated the capability of providing reliable and consistent results with the precision of the determined dynamic displacements at the millimeter level. Specifically, the research shows that the standard deviation of

Direct observation of resistive heating at graphene wrinkles and grain boundaries

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

Grosse, Kyle L.; Dorgan, Vincent E.; Estrada, David

We directly measure the nanometer-scale temperature rise at wrinkles and grain boundaries (GBs) in functioning graphene devices by scanning Joule expansion microscopy with 50 nm spatial and 0.2K temperature resolution. We observe a small temperature increase at select wrinkles and a large (100 K) temperature increase at GBs between coalesced hexagonal grains. Comparisons of measurements with device simulations estimate the GB resistivity (8 150 X lm) among the lowest reported for graphene grown by chemical vapor deposition. An analytical model is developed, showing that GBs can experience highly localized resistive heating and temperature rise, most likely affecting the reliability ofmore » graphene devices. Our studies provide an unprecedented view of thermal effects surrounding nanoscale defects in nanomaterials such as graphene.« less

Direct observation and imaging of a spin-wave soliton with p-like symmetry

NASA Astrophysics Data System (ADS)

Bonetti, S.; Kukreja, R.; Chen, Z.; Macià, F.; Hernàndez, J. M.; Eklund, A.; Backes, D.; Frisch, J.; Katine, J.; Malm, G.; Urazhdin, S.; Kent, A. D.; Stöhr, J.; Ohldag, H.; Dürr, H. A.

2015-11-01

Spin waves, the collective excitations of spins, can emerge as nonlinear solitons at the nanoscale when excited by an electrical current from a nanocontact. These solitons are expected to have essentially cylindrical symmetry (that is, s-like), but no direct experimental observation exists to confirm this picture. Using a high-sensitivity time-resolved magnetic X-ray microscopy with 50 ps temporal resolution and 35 nm spatial resolution, we are able to create a real-space spin-wave movie and observe the emergence of a localized soliton with a nodal line, that is, with p-like symmetry. Micromagnetic simulations explain the measurements and reveal that the symmetry of the soliton can be controlled by magnetic fields. Our results broaden the understanding of spin-wave dynamics at the nanoscale, with implications for the design of magnetic nanodevices.

Direct observation of nucleation in the bulk of an opaque sample.

PubMed

Xu, Chaoling; Zhang, Yubin; Godfrey, Andrew; Wu, Guilin; Liu, Wenjun; Tischler, Jonathan Z; Liu, Qing; Juul Jensen, Dorte

2017-02-14

Remarkably little is known about the physical phenomena leading to nucleation of new perfect crystals within deformed metals during annealing, in particular how and where volumes with nearly perfect lattices evolve from structures filled with dislocations, and how local variations at the micrometer length scale affect this nucleation process. We present here the first experimental measurements that relate directly nucleation of recrystallization to the local deformation microstructure in the bulk of a sample of cold rolled aluminum, further deformed locally by a hardness indentation. White beam differential aperture X-ray microscopy is used for the measurements, allowing us to map a selected gauge volume in the bulk of the sample in the deformed state, then anneal the sample and map the exact same gauge volume in the annealed state. It is found that nuclei develop at sites of high stored energy and they have crystallographic orientations from those present in the deformed state. Accordingly we suggest that for each nucleus the embryonic volume arises from a structural element contained within the voxels identified with the same orientation. Possible nucleation mechanisms are discussed and the growth potentials of the nuclei are also analyzed and discussed.

Observer's Interface for Solar System Target Specification

NASA Astrophysics Data System (ADS)

Roman, Anthony; Link, Miranda; Moriarty, Christopher; Stansberry, John A.

2016-10-01

When observing an asteroid or comet with HST, it has been necessary for the observer to manually enter the target's orbital elements into the Astronomer's Proposal Tool (APT). This allowed possible copy/paste transcription errors from the observer's source of orbital elements data. In order to address this issue, APT has now been improved with the capability to identify targets in and then download orbital elements from JPL Horizons. The observer will first use a target name resolver to choose the intended target from the Horizons database, and then download the orbital elements from Horizons directly into APT. A manual entry option is also still retained if the observer does not wish to use elements from Horizons. This new capability is available for HST observing, and it will also be supported for JWST observing. The poster shows examples of this new interface.

Observer's Interface for Solar System Target Specification

NASA Astrophysics Data System (ADS)

Roman, Anthony; Link, Miranda; Moriarty, Christopher; Stansberry, John A.

2016-01-01

When observing an asteroid or comet with HST, it has been necessary for the observer to manually enter the target's orbital elements into the Astronomer's Proposal Tool (APT). This allowed possible copy/paste transcription errors from the observer's source of orbital elements data. In order to address this issue, APT has now been improved with the capability to identify targets in and then download orbital elements from JPL Horizons. The observer will first use a target name resolver to choose the intended target from the Horizons database, and then download the orbital elements from Horizons directly into APT. A manual entry option is also still retained if the observer does not wish to use elements from Horizons. This new capability is available for HST observing, and it will also be supported for JWST observing. The poster shows examples of this new interface.

Reduction of uncertainty in global black carbon direct radiative forcing constrained by observations

NASA Astrophysics Data System (ADS)

Wang, R.; Balkanski, Y.; Boucher, O.; Ciais, P.; Schuster, G. L.; Chevallier, F.; Samset, B. H.; Valari, M.; Liu, J.; Tao, S.

2017-12-01

Black carbon (BC) absorbs sunlight and contributes to global warming. However, the size of this effect, namely the direct radiative forcing (DRF), ranges from +0.1 to +1.0 W m-2, largely due to discrepancies between modeled and observed BC radiation absorption. Studies that adjusted emissions to correct biases of models resulted in a revised upward estimate of the BC DRF. However, the observation-based BC RF was not optimized against observations in a rigorous mathematical manner, because uncertainties in emissions and the representativeness errors due to use of coarse-resolution models were not fully assessed. Here we simulated the absorption of solar radiation by BC from all sources at the 10-km resolution by combining a nested aerosol model with a downscaling method. The normalized mean bias in BC radiation absorption was reduced from -51% to -24% in Asia and from -57% to -50% elsewhere. We applied a Bayesian method that account for model, representativeness and observational uncertainties to estimate the BC RF and its uncertainty. Using the high-resolution model reduces uncertainty in BC DRF from -101%/+152% to -70%/+71% over Asia and from -83%/+108% to -64%/+68% over other continental regions. We derived an observation-based BC DRF of 0.61 Wm-2 (0.16 to 1.40 as 90% confidence) as our best estimate.

Motion of single wandering diblock-macromolecules directed by a PTFE nano-fence: real time SFM observations.

PubMed

Gallyamov, Marat O; Qin, Shuhui; Matyjaszewski, Krzysztof; Khokhlov, Alexei; Möller, Martin

2009-07-21

Using SFM we have observed a peculiar twisting motion of diblock macromolecules pre-collapsed in ethanol vapour during their subsequent spreading in water vapour. The intrinsic asymmetry of the diblock macromolecules has been considered to be the reason for such twisting. Further, friction-deposited PTFE nano-stripes have been employed as nano-trails with the purpose of inducing lateral directed motion of the asymmetric diblock macromolecules under cyclic impact from the changing vapour surroundings. Indeed, some of the macromolecules have demonstrated a certain tendency to orient along the PTFE stripes, and some of the oriented ones have moved occasionally in a directed manner along the trail. However, it has been difficult to reliably record such directed motion at the single molecule level due to some mobility of the PTFE nano-trails themselves in the changing vapour environment. In vapours, the PTFE stripes have demonstrated a distinct tendency towards conjunction. This tendency has manifested itself in efficient expelling of groups of the mobile brush-like molecules from the areas between two PTFE stripes joining in a zip-fastener manner. This different kind of vapour-induced cooperative macromolecular motion has been reliably observed as being directed. The PTFE nano-frame experiences some deformation when constraining the spreading macromolecules. We have estimated the possible force causing such deformation of the PTFE fence. The force has been found to be a few pN as calculated by a partial contribution from every single molecule of the constrained group.

Ultrafast observation of lattice dynamics in laser-irradiated gold foils

DOE PAGES

Hartley, N. J.; Ozaki, Norimasa; Matsuoka, T.; ...

2017-02-13

Here, we have observed the lattice expansion before the onset of compression in an optical-laser-driven target, using diffraction of femtosecond X-ray beams generated by the SPring-8 Angstrom Compact Free-electron Laser. The change in diffraction angle provides a direct measure of the lattice spacing, allowing the density to be calculated with a precision of ±1%. From the known equation of state relations, this allows an estimation of the temperature responsible for the expansion as <1000 K. The subsequent ablation-driven compression was observed with a clear rise in density at later times. This demonstrates the feasibility of studying the dynamics of preheatingmore » and shock formation with unprecedented detail.« less

Ultrafast observation of lattice dynamics in laser-irradiated gold foils

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

Hartley, N. J.; Ozaki, Norimasa; Matsuoka, T.

Here, we have observed the lattice expansion before the onset of compression in an optical-laser-driven target, using diffraction of femtosecond X-ray beams generated by the SPring-8 Angstrom Compact Free-electron Laser. The change in diffraction angle provides a direct measure of the lattice spacing, allowing the density to be calculated with a precision of ±1%. From the known equation of state relations, this allows an estimation of the temperature responsible for the expansion as <1000 K. The subsequent ablation-driven compression was observed with a clear rise in density at later times. This demonstrates the feasibility of studying the dynamics of preheatingmore » and shock formation with unprecedented detail.« less

ARCADO - Adding random case analysis to direct observation in workplace-based formative assessment of general practice registrars.

PubMed

Ingham, Gerard; Fry, Jennifer; Morgan, Simon; Ward, Bernadette

2015-12-10

Workplace-based formative assessments using consultation observation are currently conducted during the Australian general practice training program. Assessment reliability is improved by using multiple assessment methods. The aim of this study was to explore experiences of general practice medical educator assessors and registrars (trainees) when adding random case analysis to direct observation (ARCADO) during formative workplace-based assessments. A sample of general practice medical educators and matched registrars were recruited. Following the ARCADO workplace assessment, semi-structured qualitative interviews were conducted. The data was analysed thematically. Ten registrars and eight medical educators participated. Four major themes emerged - formative versus summative assessment; strengths (acceptability, flexibility, time efficiency, complementarity and authenticity); weaknesses (reduced observation and integrity risks); and contextual factors (variation in assessment content, assessment timing, registrar-medical educator relationship, medical educator's approach and registrar ability). ARCADO is a well-accepted workplace-based formative assessment perceived by registrars and assessors to be valid and flexible. The use of ARCADO enabled complementary insights that would not have been achieved with direct observation alone. Whilst there are some contextual factors to be considered in its implementation, ARCADO appears to have utility as formative assessment and, subject to further evaluation, high-stakes assessment.

High Spectral Resolution Observation of the Soft Diffuse X-ray Background in the Direction of the Galactic Anti-Center

NASA Astrophysics Data System (ADS)

Wulf, Dallas; Eckart, Mega E.; Galeazzi, Massimiliano; Jaeckel, Felix; Kelley, Richard L.; Kilbourne, Caroline A.; McCammon, Dan; Morgan, Kelsey M.; Porter, Frederick S.; Szymkowiak, Andrew E.

2018-01-01

High spectral resolution observations in the soft x-rays are necessary for understanding and modelling the hot component of the interstellar medium and its contribution to the Soft X-ray Background (SXRB). This extended source emission cannot be resolved with most wavelength dispersive spectrometers, making energy dispersive microcalorimeters the ideal choice for these observations. We present here the analysis of the most recent sounding rocket flight of the University of Wisconsin-Madison/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC), a large area silicon thermistor microcalorimeter. This 111 second observation integrates a nearly 1 steradian field of view in the direction of the galactic anti-center (l, b = 165°, -5°) and features ~5 eV spectral resolution below 1 keV. Direct comparison will also be made to the previous, high-latitude observations.

Direct observation and imaging of a spin-wave soliton with p-like symmetry

DOE PAGES

Bonetti, S.; Kukreja, R.; Chen, Z.; ...

2015-11-16

Spin waves, the collective excitations of spins, can emerge as nonlinear solitons at the nanoscale when excited by an electrical current from a nanocontact. These solitons are expected to have essentially cylindrical symmetry (that is, s-like), but no direct experimental observation exists to confirm this picture. Using a high-sensitivity time-resolved magnetic X-ray microscopy with 50 ps temporal resolution and 35 nm spatial resolution, we are able to create a real-space spin-wave movie and observe the emergence of a localized soliton with a nodal line, that is, with p-like symmetry. Moreover, micromagnetic simulations explain the measurements and reveal that the symmetrymore » of the soliton can be controlled by magnetic fields. Our results broaden the understanding of spin-wave dynamics at the nanoscale, with implications for the design of magnetic nanodevices.« less

Performing Gram stain directly on catheter tips: assessment of the quality of the observation process.

PubMed

Guembe, M; Pérez-Granda, M J; Rivera, M L; Martín-Rabadán, P; Bouza, E

2015-06-01

A previous study performed in our institution showed that catheter tip (CT) staining by combining acridine orange and Gram stain (GS) before culture anticipated catheter colonization with exhaustive and careful observation by a highly trained technician. Our objective was to assess the validity values of GS without acridine orange on an external smear of CT for predicting catheter colonization and catheter-related bloodstream infection (C-RBSI). We compared different periods of observation and the results of two technicians with different levels of professional experience. Over a 5-month period, the roll-plate technique was preceded by direct GS of all CTs sent to the microbiology laboratory. The reading was taken at ×100 by two observers with different skill levels. Each observer performed a routine examination (3 min along three longitudinal lines) and an exhaustive examination (5 min along five longitudinal lines). The presence of at least one cell was considered positive. All slides were read before culture results were known. We included a total of 271 CTs from 209 patients. The prevalence of catheter colonization and C-RBSI was 16.2 % and 5.1 %, respectively. Routine and exhaustive examinations revealed only 29.5 % and 40.9 % of colonized catheters, respectively (p < 0.001). In contrast, they revealed high negative predictive values for C-RBSI (96.5 % and 96.3 %, respectively). Our study shows that the yield of GS performed directly on CTs is greater when staining is performed exhaustively. However, the decision to implement this approach in daily routine will depend on the prevalence rate of catheter colonization at each institution.

Direct Observation of Domain-Wall Surface Tension by Deflating or Inflating a Magnetic Bubble

NASA Astrophysics Data System (ADS)

Zhang, Xueying; Vernier, Nicolas; Zhao, Weisheng; Yu, Haiming; Vila, Laurent; Zhang, Yue; Ravelosona, Dafiné

2018-02-01

The surface energy of a magnetic domain wall (DW) strongly affects its static and dynamic behaviors. However, this effect is seldom directly observed, and some of the related phenomena are not well understood. Moreover, a reliable method to quantify the DW surface energy is still absent. Here, we report a series of experiments in which the DW surface energy becomes a dominant parameter. We observe that a semicircular magnetic domain bubble can spontaneously collapse under the Laplace pressure induced by DW surface energy. We further demonstrate that the surface energy can lead to a geometrically induced pinning when the DW propagates in a Hall cross or from a nanowire into a nucleation pad. Based on these observations, we develop two methods to quantify the DW surface energy, which can be very helpful in the estimation of intrinsic parameters such as Dzyaloshinskii-Moriya interactions or exchange stiffness in magnetic ultrathin films.

a Direct Observation of the Asteroid's Structure from Deep Interior to Regolith: Two Radars on the Aim Mission

NASA Astrophysics Data System (ADS)

Herique, A.; Ciarletti, V.; Plettemeier, D.; Grygorczuk, J.

2016-12-01

Our knowledge of the internal structure of asteroids entirely relies on inferences from remote sensing observations of the surface and theoretical modeling. Is the body a monolithic piece of rock or a rubble-pile, how high is the porosity? What is the typical size of the constituent blocs? Are these blocs homogeneous or heterogeneous? The body is covered by a regolith whose properties remain largely unknown in term of depth, size distribution and spatial variability. Is it resulting from fine particles re-accretion or from thermal fracturing? After several asteroid orbiting missions, theses crucial and yet basic questions remain open. Direct measurements of asteroid deep interior and regolith structure are needed to better understand the asteroid accretion and dynamical evolution and to provide answers that will directly improve our ability to understand the formation and evolution of the Near Earth Asteroids (NEA), that will allow us to model the mechanisms driving NEA deflection and other risk mitigation techniques. Radars operating at distance from a spacecraft are the only instruments capable of achieving this science objective of characterizing the internal structure and heterogeneity from submetric to global scale for the benefit of science as well as for planetary defense or exploration. The AIM mission will have two complementary radars on-board, operating at different frequencies in order to meet the objectives requirements. The deep interior structure tomography requires a low-frequency radar (LFR) in order to propagate throughout the complete body and characterize the deep interior: this LFR will be a direct heritage of the CONSERT radar designed for the Rosetta mission. Ihe characterization of the first ten meters of the subsurface with a metric resolution to identify layering and to reconnect surface measurements to internal structure will be achieved with a higher frequency radar (HFR). The design of HFR is based on the WISDOM radar developed for the

Direct observation of forward-scattering oscillations in the H+HD→H2+D reaction

NASA Astrophysics Data System (ADS)

Yuan, Daofu; Yu, Shengrui; Chen, Wentao; Sang, Jiwei; Luo, Chang; Wang, Tao; Xu, Xin; Casavecchia, Piergiorgio; Wang, Xingan; Sun, Zhigang; Zhang, Dong H.; Yang, Xueming

2018-06-01

Accurate measurements of product state-resolved angular distributions are central to fundamental studies of chemical reaction dynamics. Yet, fine quantum-mechanical structures in product angular distributions of a reactive scattering process, such as the fast oscillations in the forward-scattering direction, have never been observed experimentally and the nature of these oscillations has not been fully explored. Here we report the crossed-molecular-beam experimental observation of these fast forward-scattering oscillations in the product angular distribution of the benchmark chemical reaction, H + HD → H2 + D. Clear oscillatory structures are observed for the H2(v' = 0, j' = 1, 3) product states at a collision energy of 1.35 eV, in excellent agreement with the quantum-mechanical dynamics calculations. Our analysis reveals that the oscillatory forward-scattering components are mainly contributed by the total angular momentum J around 28. The partial waves and impact parameters responsible for the forward scatterings are also determined from these observed oscillations, providing crucial dynamics information on the transient reaction process.

Direct observation of forward-scattering oscillations in the H+HD→H2+D reaction.

PubMed

Yuan, Daofu; Yu, Shengrui; Chen, Wentao; Sang, Jiwei; Luo, Chang; Wang, Tao; Xu, Xin; Casavecchia, Piergiorgio; Wang, Xingan; Sun, Zhigang; Zhang, Dong H; Yang, Xueming

2018-06-01

Accurate measurements of product state-resolved angular distributions are central to fundamental studies of chemical reaction dynamics. Yet, fine quantum-mechanical structures in product angular distributions of a reactive scattering process, such as the fast oscillations in the forward-scattering direction, have never been observed experimentally and the nature of these oscillations has not been fully explored. Here we report the crossed-molecular-beam experimental observation of these fast forward-scattering oscillations in the product angular distribution of the benchmark chemical reaction, H + HD → H 2  + D. Clear oscillatory structures are observed for the H 2 (v' = 0, j' = 1, 3) product states at a collision energy of 1.35 eV, in excellent agreement with the quantum-mechanical dynamics calculations. Our analysis reveals that the oscillatory forward-scattering components are mainly contributed by the total angular momentum J around 28. The partial waves and impact parameters responsible for the forward scatterings are also determined from these observed oscillations, providing crucial dynamics information on the transient reaction process.

The Myth of Spatial Reuse with Directional Antennas in Indoor Wireless Networks

NASA Astrophysics Data System (ADS)

Lakshmanan, Sriram; Sundaresan, Karthikeyan; Rangarajan, Sampath; Sivakumar, Raghupathy

Interference among co-channel users is a fundamental problem in wireless networks, which prevents nearby links from operating concurrently. Directional antennas allow the radiation patterns of wireless transmitters to be shaped to form directed beams. Conventionally, such beams are assumed to improve the spatial reuse (i.e. concurrency) in indoor wireless networks. In this paper, we use experiments in an indoor office setting of Wifi Access points equipped with directional antennas, to study their potential for interference mitigation and spatial reuse. In contrast to conventional wisdom, we observe that the interference mitigation benefits of directional antennas are minimal. On analyzing our experimental traces we observe that directional links do not reduce interference to nearby links due to the lack of signal confinement due to indoor multipath fading. We then use the insights derived from our study to develop an alternative approach that provides better interference reduction in indoor networks compared to directional links.

Direct observation of slow intersystem crossing in an aromatic ketone, fluorenone.

PubMed

Soep, Benoît; Mestdagh, Jean-Michel; Briant, Marc; Gaveau, Marc-André; Poisson, Lionel

2016-08-17

Direct measurements of Single vibronic Level InterSystem Crossing (SLISC) have been performed on the fluorenone molecule in the gas phase, by time resolved photoelectron and photoion spectroscopy. Vibronic transitions above the S1 nπ* origin were excited in the 432-420 nm region and the decay of S1 and growth of T1(3)ππ* could be observed within a 10 ns time domain. The ionization potential is measured as 8.33 ± 0.04 eV. The energy of the first excited triplet state of fluorenone, T1 has been characterized directly at 18 640 ± 250 cm(-1). The internal conversion of S1 to S0 is found to amount to ∼15% of the population decay, thus ISC is the dominant electronic relaxation process. ISC, although favored by the S1(1)nπ*-T1(3)ππ* coupling scheme, is 3 orders of magnitude less efficient than in the similar molecule benzophenone. Thus, the planarity of the fluorenone molecule disfavors the exploration of the configuration space where surface crossings would create high ISC probability, which occurs in benzophenone through surface crossings. The time evolution of S1 fluorenone is well accounted for by the statistical decay of individual levels into a quasi-continuum of T1 vibronic levels.

Direct AFM observation of an opening event of a DNA cuboid constructed via a prism structure.

PubMed

Endo, Masayuki; Hidaka, Kumi; Sugiyama, Hiroshi

2011-04-07

A cuboid structure was constructed using a DNA origami design based on a square prism structure. The structure was characterized by atomic force microscopy (AFM) and dynamic light scattering. The real-time opening event of the cuboid was directly observed by high-speed AFM.

Direct observation and control of hydrogen-bond dynamics using low-temperature scanning tunneling microscopy

NASA Astrophysics Data System (ADS)

Kumagai, Takashi

2015-08-01

Hydrogen(H)-bond dynamics are involved in many elementary processes in chemistry and biology. Because of its fundamental importance, a variety of experimental and theoretical approaches have been employed to study the dynamics in gas, liquid, solid phases, and their interfaces. This review describes the recent progress of direct observation and control of H-bond dynamics in several model systems on a metal surface by using low-temperature scanning tunneling microscopy (STM). General aspects of H-bond dynamics and the experimental methods are briefly described in chapter 1 and 2. In the subsequent four chapters, I present direct observation of an H-bond exchange reaction within a single water dimer (chapter 3), a symmetric H bond (chapter 4) and H-atom relay reactions (chapter 5) within water-hydroxyl complexes, and an intramolecular H-atom transfer reaction (tautomerization) within a single porphycene molecule (chapter 6). These results provide novel microscopic insights into H-bond dynamics at the single-molecule level, and highlight significant impact on the process from quantum effects, namely tunneling and zero-point vibration, resulting from the small mass of H atom. Additionally, local environmental effect on H-bond dynamics is also examined by using atom/molecule manipulation with the STM.

Direct Observation of Protein Microcrystals in Crystallization Buffer by Atmospheric Scanning Electron Microscopy

PubMed Central

Maruyama, Yuusuke; Ebihara, Tatsuhiko; Nishiyama, Hidetoshi; Konyuba, Yuji; Senda, Miki; Numaga-Tomita, Takuro; Senda, Toshiya; Suga, Mitsuo; Sato, Chikara

2012-01-01

X-ray crystallography requires high quality crystals above a given size. This requirement not only limits the proteins to be analyzed, but also reduces the speed of the structure determination. Indeed, the tertiary structures of many physiologically important proteins remain elusive because of the so-called “crystallization bottleneck”. Once microcrystals have been obtained, crystallization conditions can be optimized to produce bigger and better crystals. However, the identification of microcrystals can be difficult due to the resolution limit of optical microscopy. Electron microscopy has sometimes been utilized instead, with the disadvantage that the microcrystals usually must be observed in vacuum, which precludes the usage for crystal screening. The atmospheric scanning electron microscope (ASEM) allows samples to be observed in solution. Here, we report the use of this instrument in combination with a special thin-membrane dish with a crystallization well. It was possible to observe protein crystals of lysozyme, lipase B and a histone chaperone TAF-Iβ in crystallization buffers, without the use of staining procedures. The smallest crystals observed with ASEM were a few μm in width, and ASEM can be used with non-transparent solutions. Furthermore, the growth of salt crystals could be monitored in the ASEM, and the difference in contrast between salt and protein crystals made it easy to distinguish between these two types of microcrystals. These results indicate that the ASEM could be an important new tool for the screening of protein microcrystals. PMID:22949879

Direct observation of protein microcrystals in crystallization buffer by atmospheric scanning electron microscopy.

PubMed

Maruyama, Yuusuke; Ebihara, Tatsuhiko; Nishiyama, Hidetoshi; Konyuba, Yuji; Senda, Miki; Numaga-Tomita, Takuro; Senda, Toshiya; Suga, Mitsuo; Sato, Chikara

2012-01-01

X-ray crystallography requires high quality crystals above a given size. This requirement not only limits the proteins to be analyzed, but also reduces the speed of the structure determination. Indeed, the tertiary structures of many physiologically important proteins remain elusive because of the so-called "crystallization bottleneck". Once microcrystals have been obtained, crystallization conditions can be optimized to produce bigger and better crystals. However, the identification of microcrystals can be difficult due to the resolution limit of optical microscopy. Electron microscopy has sometimes been utilized instead, with the disadvantage that the microcrystals usually must be observed in vacuum, which precludes the usage for crystal screening. The atmospheric scanning electron microscope (ASEM) allows samples to be observed in solution. Here, we report the use of this instrument in combination with a special thin-membrane dish with a crystallization well. It was possible to observe protein crystals of lysozyme, lipase B and a histone chaperone TAF-Iβ in crystallization buffers, without the use of staining procedures. The smallest crystals observed with ASEM were a few μm in width, and ASEM can be used with non-transparent solutions. Furthermore, the growth of salt crystals could be monitored in the ASEM, and the difference in contrast between salt and protein crystals made it easy to distinguish between these two types of microcrystals. These results indicate that the ASEM could be an important new tool for the screening of protein microcrystals.

Increasing community capacity for participatory evaluation of healthy eating and active living strategies through direct observations and environmental audits.

PubMed

Kemner, Allison L; Stachecki, Jessica R; Bildner, Michele E; Brennan, Laura K

2015-01-01

Local partnerships from the Healthy Kids, Healthy Communities initiative elected to participate in enhanced evaluation trainings to collect data through environmental audits and direct observations as well as to build their evaluation capacity. Environmental audit and direct observation tools and protocols were adapted for the relevant healthy eating and active living policy and environmental change approaches being conducted by the Healthy Kids, Healthy Communities partnerships. Customized trainings were conducted by the evaluation team to increase capacity and understanding for evaluation activities. A total of 87 trainings were conducted by the evaluation team in 31 Healthy Kids, Healthy Communities community partnerships. Data were collected for a total of 41 environmental audits and 17 direct observations. Community case examples illustrate how these trainings developed evaluation capacity. For instance, youth from one community presented environmental audit findings to local elected officials. The 31 partnerships participating in the community-based evaluation efforts resulted in 164 individuals trained in collecting context-specific data to assess the impact of healthy eating and active living policy and environmental strategies designed to create community change.

Direct observation of the transition from calcite to aragonite growth as induced by abalone shell proteins.

PubMed Central

Thompson, J B; Paloczi, G T; Kindt, J H; Michenfelder, M; Smith, B L; Stucky, G; Morse, D E; Hansma, P K

2000-01-01

The mixture of EDTA-soluble proteins found in abalone nacre are known to cause the nucleation and growth of aragonite on calcite seed crystals in supersaturated solutions of calcium carbonate. Past atomic force microscope studies of the interaction of these proteins with calcite crystals did not observe this transition because no information about the crystal polymorph on the surface was obtained. Here we have used the atomic force microscope to directly observe changes in the atomic lattice on a calcite seed crystal after the introduction of abalone shell proteins. The observed changes are consistent with a transition to (001) aragonite growth on a (1014) calcite surface. PMID:11106633

Higher Throughput Toxicokinetics to Allow Extrapolation (EPA-Japan Bilateral EDSP meeting)

EPA Science Inventory

As part of "Ongoing EDSP Directions & Activities" I will present CSS research on high throughput toxicokinetics, including in vitro data and models to allow rapid determination of the real world doses that may cause endocrine disruption.

Direct and simultaneous observation of ultrafast electron and hole dynamics in germanium

DOE PAGES

Zurch, Michael; Chang, Hung -Tzu; Borja, Lauren J.; ...

2017-06-01

Understanding excited carrier dynamics in semiconductors is crucial for the development of photovoltaics and efficient photonic devices. However, overlapping spectral features in optical pump-probe spectroscopy often render assignments of separate electron and hole carrier dynamics ambiguous. Here, ultrafast electron and hole dynamics in germanium nanocrystalline thin films are directly and simultaneously observed by ultrafast transient absorption spectroscopy in the extreme ultraviolet at the germanium M 4,5 edge. We decompose the spectra into contributions of electronic state blocking and photo-induced band shifts at a carrier density of 8 × 10 20 cm –3. Separate electron and hole relaxation times are observedmore » as a function of hot carrier energies. A first-order electron and hole decay of ~1 ps suggests a Shockley–Read–Hall recombination mechanism. Furthermore, the simultaneous observation of electrons and holes with extreme ultraviolet transient absorption spectroscopy paves the way for investigating few- to sub-femtosecond dynamics of both holes and electrons in complex semiconductor materials and across junctions.« less

Direct and simultaneous observation of ultrafast electron and hole dynamics in germanium

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

Zurch, Michael; Chang, Hung -Tzu; Borja, Lauren J.

Understanding excited carrier dynamics in semiconductors is crucial for the development of photovoltaics and efficient photonic devices. However, overlapping spectral features in optical pump-probe spectroscopy often render assignments of separate electron and hole carrier dynamics ambiguous. Here, ultrafast electron and hole dynamics in germanium nanocrystalline thin films are directly and simultaneously observed by ultrafast transient absorption spectroscopy in the extreme ultraviolet at the germanium M 4,5 edge. We decompose the spectra into contributions of electronic state blocking and photo-induced band shifts at a carrier density of 8 × 10 20 cm –3. Separate electron and hole relaxation times are observedmore » as a function of hot carrier energies. A first-order electron and hole decay of ~1 ps suggests a Shockley–Read–Hall recombination mechanism. Furthermore, the simultaneous observation of electrons and holes with extreme ultraviolet transient absorption spectroscopy paves the way for investigating few- to sub-femtosecond dynamics of both holes and electrons in complex semiconductor materials and across junctions.« less

30 CFR 1220.011 - Schedule of allowable direct and allocable joint costs and credits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering design problems related to equipment or facilities required for NPSL operations. (4) The cost of any contract service related to research and development is specifically excluded, as are contract services calling for feasibility studies not directly related to specific engineering design problems or...

Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

DOE PAGES

Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; ...

2015-05-14

In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation andmore » streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.« less

Direct atomic force microscopy observation of DNA tile crystal growth at the single-molecule level.

PubMed

Evans, Constantine G; Hariadi, Rizal F; Winfree, Erik

2012-06-27

While the theoretical implications of models of DNA tile self-assembly have been extensively researched and such models have been used to design DNA tile systems for use in experiments, there has been little research testing the fundamental assumptions of those models. In this paper, we use direct observation of individual tile attachments and detachments of two DNA tile systems on a mica surface imaged with an atomic force microscope (AFM) to compile statistics of tile attachments and detachments. We show that these statistics fit the widely used kinetic Tile Assembly Model and demonstrate AFM movies as a viable technique for directly investigating DNA tile systems during growth rather than after assembly.

Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering.

PubMed

Follett, R K; Edgell, D H; Henchen, R J; Hu, S X; Katz, J; Michel, D T; Myatt, J F; Shaw, J; Froula, D H

2015-03-01

A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPD EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability.

Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering

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

Follett, R. K.; Edgell, D. H.; Henchen, R. J.

2015-03-26

A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPDmore » EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability.« less

Direct Imaging of Warm Extrasolar Planets

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

Macintosh, B

2005-04-11

One of the most exciting scientific discoveries in the last decade of the twentieth century was the first detection of planets orbiting a star other than our own. By now more than 130 extrasolar planets have been discovered indirectly, by observing the gravitational effects of the planet on the radial velocity of its parent star. This technique has fundamental limitations: it is most sensitive to planets close to their star, and it determines only a planet's orbital period and a lower limit on the planet's mass. As a result, all the planetary systems found so far are very different frommore » our own--they have giant Jupiter-sized planets orbiting close to their star, where the terrestrial planets are found in our solar system. Such systems have overturned the conventional paradigm of planet formation, but have no room in them for habitable Earth-like planets. A powerful complement to radial velocity detections of extrasolar planets will be direct imaging--seeing photons from the planet itself. Such a detection would allow photometric measurements to determine the temperature and radius of a planet. Also, direct detection is most sensitive to planets in wide orbits, and hence more capable of seeing solar systems resembling our own, since a giant planet in a wide orbit does not preclude the presence of an Earth-like planet closer to the star. Direct detection, however, is extremely challenging. Jupiter is roughly a billion times fainter than our sun. Two techniques allowed us to overcome this formidable contrast and attempt to see giant planets directly. The first is adaptive optics (AO) which allows giant earth-based telescopes, such as the 10 meter W.M. Keck telescope, to partially overcome the blurring effects of atmospheric turbulence. The second is looking for young planets: by searching in the infrared for companions to young stars, we can see thermal emission from planets that are still warm with the heat of their formation. Together with a UCLA team that

Direct Radiative Effect of Aerosols Based on PARASOL and OMI Satellite Observations

NASA Technical Reports Server (NTRS)

Lacagnina, Carlo; Hasekamp, Otto P.; Torres, Omar

2017-01-01

Accurate portrayal of the aerosol characteristics is crucial to determine aerosol contribution to the Earth's radiation budget. We employ novel satellite retrievals to make a new measurement-based estimate of the shortwave direct radiative effect of aerosols (DREA), both over land and ocean. Global satellite measurements of aerosol optical depth, single-scattering albedo (SSA), and phase function from PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) are used in synergy with OMI (Ozone Monitoring Instrument) SSA. Aerosol information is combined with land-surface bidirectional reflectance distribution function and cloud characteristics from MODIS (Moderate Resolution Imaging Spectroradiometer) satellite products. Eventual gaps in observations are filled with the state-of-the-art global aerosol model ECHAM5-HAM2. It is found that our estimate of DREA is largely insensitive to model choice. Radiative transfer calculations show that DREA at top-of-atmosphere is -4.6 +/- 1.5 W/sq m for cloud-free and -2.1 +/- 0.7 W/sq m for all-sky conditions, during year 2006. These fluxes are consistent with, albeit generally less negative over ocean than, former assessments. Unlike previous studies, our estimate is constrained by retrievals of global coverage SSA, which may justify different DREA values. Remarkable consistency is found in comparison with DREA based on CERES (Clouds and the Earth's Radiant Energy System) and MODIS observations.

Dislocation-pipe diffusion in nitride superlattices observed in direct atomic resolution.

PubMed

Garbrecht, Magnus; Saha, Bivas; Schroeder, Jeremy L; Hultman, Lars; Sands, Timothy D

2017-04-06

Device failure from diffusion short circuits in microelectronic components occurs via thermally induced migration of atoms along high-diffusivity paths: dislocations, grain boundaries, and free surfaces. Even well-annealed single-grain metallic films contain dislocation densities of about 10 14  m -2 ; hence dislocation-pipe diffusion (DPD) becomes a major contribution at working temperatures. While its theoretical concept was established already in the 1950s and its contribution is commonly measured using indirect tracer, spectroscopy, or electrical methods, no direct observation of DPD at the atomic level has been reported. We present atomically-resolved electron microscopy images of the onset and progression of diffusion along threading dislocations in sequentially annealed nitride metal/semiconductor superlattices, and show that this type of diffusion can be independent of concentration gradients in the system but governed by the reduction of strain fields in the lattice.

Direct observation of nucleation in the bulk of an opaque sample

DOE PAGES

Xu, Chaoling; Zhang, Yubin; Godfrey, Andrew; ...

2017-02-14

Remarkably little is known about the physical phenomena leading to nucleation of new perfect crystals within deformed metals during annealing, in particular how and where volumes with nearly perfect lattices evolve from structures filled with dislocations, and how local variations at the micrometer length scale affect this nucleation process. We present here the first experimental measurements that relate directly nucleation of recrystallization to the local deformation microstructure in the bulk of a sample of cold rolled aluminum, further deformed locally by a hardness indentation. White beam differential aperture X-ray microscopy is used for the measurements, allowing us to map amore » selected gauge volume in the bulk of the sample in the deformed state, then anneal the sample and map the exact same gauge volume in the annealed state. It is found that nuclei develop at sites of high stored energy and they have crystallographic orientations from those present in the deformed state. Accordingly we suggest that for each nucleus the embryonic volume arises from a structural element contained within the voxels identified with the same orientation. In conclusion, possible nucleation mechanisms are discussed and the growth potentials of the nuclei are also analyzed and discussed.« less

The breakup of large tabular icebergs - direct observations and theoretical considerations

NASA Astrophysics Data System (ADS)

Wadhams, P.

2013-12-01

Peter Wadhams and Till Wagner Dept. of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge. We review the factors governing the stability, dynamics and decay of icebergs and describe areas where current models are inadequate. These include questions such as draft changes in capsizing icebergs; iceberg trajectory modelling; the melt rate of the ice underside and ways of reducing it; and wave-induced flexure and its role in the break-up of tabular icebergs. In July 2012 the authors worked on a very large (42 sq km) tabular iceberg in Baffin Bay, which had calved from the Petermann Glacier in NW Greenland. We measured incoming swell spectrum and the iceberg response; also the role of buoyancy forces due to erosion of a waterline wave cut and the creation of an underwater ram. The iceberg broke up while we were on it, allowing an instrumental measurement of the calving event. The experiments were included in the BBC-2 film 'Operation Iceberg' shown on Nov 1 2012 and repeated on Nov 18. We conclude that two processes interacted in the break-up event: increased bending stress due to buoyancy of underwater rams; and direct flexural strain due to incidence of ocean swell. Implications for icebergs in the open sea are estimated.

Direct measurement of light waves.

PubMed

Goulielmakis, E; Uiberacker, M; Kienberger, R; Baltuska, A; Yakovlev, V; Scrinzi, A; Westerwalbesloh, Th; Kleineberg, U; Heinzmann, U; Drescher, M; Krausz, F

2004-08-27

The electromagnetic field of visible light performs approximately 10(15) oscillations per second. Although many instruments are sensitive to the amplitude and frequency (or wavelength) of these oscillations, they cannot access the light field itself. We directly observed how the field built up and disappeared in a short, few-cycle pulse of visible laser light by probing the variation of the field strength with a 250-attosecond electron burst. Our apparatus allows complete characterization of few-cycle waves of visible, ultraviolet, and/or infrared light, thereby providing the possibility for controlled and reproducible synthesis of ultrabroadband light waveforms.

Earth Science System of the Future: Observing, Processing, and Delivering Data Products Directly to Users

NASA Technical Reports Server (NTRS)

Crisp, David; Komar, George (Technical Monitor)

2001-01-01

Advancement of our predictive capabilities will require new scientific knowledge, improvement of our modeling capabilities, and new observation strategies to generate the complex data sets needed by coupled modeling networks. New observation strategies must support remote sensing from a variety of vantage points and will include "sensorwebs" of small satellites in low Earth orbit, large aperture sensors in Geostationary orbits, and sentinel satellites at L1 and L2 to provide day/night views of the entire globe. Onboard data processing and high speed computing and communications will enable near real-time tailoring and delivery of information products (i.e., predictions) directly to users.

Structured Parent-Child Observations Predict Development of Conduct Problems: the Importance of Parental Negative Attention in Child-Directed Play.

PubMed

Fleming, Andrew P; McMahon, Robert J; King, Kevin M

2017-04-01

Structured observations of parent-child interactions are commonly used in research and clinical settings, but require additional empirical support. The current study examined the capacity of child-directed play, parent-directed play, and parent-directed chore interaction analogs to uniquely predict the development of conduct problems across a 6-year follow-up period. Parent-child observations were collected from 338 families from high-risk neighborhoods during the summer following the child's first-grade year. Participating children were 49.2 % female, 54.4 % white, and 45.6 % black, and had an average age of 7.52 years at the first assessment. Conduct problems were assessed via parent report and teacher report at five assessment points between first grade and seventh grade. Latent growth curve modeling was used to analyze predictors of conduct problem trajectory across this 6-year follow-up period. When race, sex, socioeconomic status, and maternal depressive symptoms were controlled, parental negative attention during child-directed play predicted higher levels of parent-reported conduct problems concurrently and after a 6-year follow-up period. Parental negative attention during child-directed play also predicted higher teacher-reported conduct problems 6 years later. Findings support the use of child-directed play and parent-directed chore analogs in predicting longitudinal development of conduct problems. The presence of parental negative attention during child-directed play appears to be an especially important predictor of greater conduct problems over time and across multiple domains. Additionally, the potential importance of task-incongruent behavior is proposed for further study.

Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy

NASA Astrophysics Data System (ADS)

Tay, S. E. R.; Goode, A. E.; Nelson Weker, J.; Cruickshank, A. A.; Heutz, S.; Porter, A. E.; Ryan, M. P.; Toney, M. F.

2016-01-01

The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation.The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation. Electronic supplementary information (ESI) available: Methods and videos of nanoparticle growth. See DOI: 10.1039/c5nr07019h

Direct Observation Through In Situ Transmission Electron Microscope of Early States of Crystallization in Nanoscale Metallic Glasses

NASA Astrophysics Data System (ADS)

Xie, Y.; Sohn, S.; Schroers, J.; Cha, J. J.

2017-11-01

Crystallization is a complex process that involves multiscale physics such as diffusion of atomic species over multiple length scales, thermodynamic energy considerations, and multiple possible intermediate states. In situ crystallization experiments inside a transmission electron microscope (TEM) using nanostructured metallic glasses (MGs) provide a unique platform to study directly crystallization kinetics and pathways. Here, we study the embryonic state of eutectic growth using Pt-Ni-Cu-P MG nanorods under in situ TEM. We directly observe the nucleation and growth of a Ni-rich polymorphic phase, followed by the nucleation and slower growth of a Cu-rich phase. The suppressed growth kinetics of the Cu-rich phase is attributed to locally changing chemical compositions. In addition, we show that growth can be controlled by incorporation of an entire nucleus instead of individual atoms. Such a nucleus has to align with the crystallographic orientation of a larger grain before it can be incorporated into the crystal. By directly observing the crystallization processes, particularly the early stages of non-polymorphic growth, in situ TEM crystallization studies of MG nanostructures provide a wealth of information, some of which can be applied to typical bulk crystallization.

Assessing Preschool Children's Physical Activity: The Observational System for Recording Physical Activity in Children-Preschool Version

ERIC Educational Resources Information Center

Brown, William H.; Pfeiffer, Karin A.; McIver, Kerry L.; Dowda, Marsha; Almeida, M. Joao C. A.; Pate, Russell R.

2006-01-01

In this paper we present initial information concerning a new direct observation system--the Observational System for Recording Physical Activity in Children-Preschool Version. The system will allow researchers to record young children's physical activity levels while also coding the topography of their physical activity, as well as detailed…

Direct observation of mother-child communication in pediatric cancer: assessment of verbal and non-verbal behavior and emotion.

PubMed

Dunn, Madeleine J; Rodriguez, Erin M; Miller, Kimberly S; Gerhardt, Cynthia A; Vannatta, Kathryn; Saylor, Megan; Scheule, C Melanie; Compas, Bruce E

2011-06-01

To examine the acceptability and feasibility of coding observed verbal and nonverbal behavioral and emotional components of mother-child communication among families of children with cancer. Mother-child dyads (N=33, children ages 5-17 years) were asked to engage in a videotaped 15-min conversation about the child's cancer. Coding was done using the Iowa Family Interaction Rating Scale (IFIRS). Acceptability and feasibility of direct observation in this population were partially supported: 58% consented and 81% of those (47% of all eligible dyads) completed the task; trained raters achieved 78% agreement in ratings across codes. The construct validity of the IFIRS was demonstrated by expected associations within and between positive and negative behavioral/emotional code ratings and between mothers' and children's corresponding code ratings. Direct observation of mother-child communication about childhood cancer has the potential to be an acceptable and feasible method of assessing verbal and nonverbal behavior and emotion in this population.

A comparison of self-report and direct observation of booster seat use in Latino families.

PubMed

Quistberg, D Alex; Lozano, Paula; Mack, Christopher D; Schwartz, Rachel; Ebel, Beth E

2010-08-01

To develop a reliable self-report tool for measuring child booster seat use among Latino families. Cross-sectional and observational survey of a convenience sample. Five retail stores in King County, Washington. 50 parents of children 4-8 years old that self-identified as Latino or Hispanic. Parent-reported measures of how often the child uses a booster seat, if the child used a booster seat on the last trip, how often the child complains about using a booster seat, how often the child asks to not use a booster seat, and how often other families they know use a booster seat. Observed booster seat use by child. 26 children (52%) were observed using a booster seat. Parent-reported booster seat use was a poor predictor of observed booster seat use. Although 34 parents reported that their child 'always' uses a booster seat, 8 (24%) of these children were not using a booster seat. A logistic model to predict booster seat use had a sensitivity of 81% and a specificity of 71%, and misclassified 24% of the participants' observed use. Reliance on parent-reported booster seat use significantly overstated observed booster seat use in the study. Among this study population, accurate determination of booster seat use required direct observation.

Interactions between C and Cu atoms in single-layer graphene: direct observation and modelling.

PubMed

Kano, Emi; Hashimoto, Ayako; Kaneko, Tomoaki; Tajima, Nobuo; Ohno, Takahisa; Takeguchi, Masaki

2016-01-07

Metal doping into the graphene lattice has been studied recently to develop novel nanoelectronic devices and to gain an understanding of the catalytic activities of metals in nanocarbon structures. Here we report the direct observation of interactions between Cu atoms and single-layer graphene by transmission electron microscopy. We document stable configurations of Cu atoms in the graphene sheet and unique transformations of graphene promoted by Cu atoms. First-principles calculations based on density functional theory reveal a reduction of energy barrier that caused rotation of C-C bonds near Cu atoms. We discuss two driving forces, electron irradiation and in situ heating, and conclude that the observed transformations were mainly promoted by electron irradiation. Our results suggest that individual Cu atoms can promote reconstruction of single-layer graphene.

Land observation from geosynchronous earth orbit (LOGEO): Mission concept and preliminary engineering analysis

NASA Astrophysics Data System (ADS)

Román-Colón, Miguel O.; Strahler, Alan H.

2007-06-01

We propose an Earth-observation mission Land Observation from Geosynchronous Earth Orbit (LOGEO) to place two spin-scan-stabilized 500-m resolution 9-band VNIR-SWIR imagers in a near-geosynchronous inclined orbit, allowing 15 min observations with a full range of daily sun angles and 30∘ variations in view angle. LOGEO drifts westward at about 4∘ per day, providing geostationary-style coverage for all points on the globe eight times per year. This unique imaging geometry allows accurate retrievals of daily changes in surface bidirectional reflectance, which in turn enhances direct retrieval of biophysical properties, as well as long term and consistent land surface parameters for modeling studies that seek to understand the Earth system and its interactions. For studies of climate and environmental dynamics, LOGEO provides accurate observations of atmospheric aerosols, clouds, as well as other atmospheric constituents across a diverse number of spatial and temporal scales. This collection of land, atmospheric, and climate data products are directly applicable to seven of the nine GEOSS societal benefits areas, providing great opportunities for international collaboration. We also present an overview of LOGEO's systems architecture, as well as top-level design-trade studies and orbital scenarios.

CAN-DOO: The Climate Action Network through Direct Observations and Outreach

NASA Astrophysics Data System (ADS)

Taubman, B.; Sherman, J. P.; Perry, L. B.; Markham, J.; Kelly, G.

2011-12-01

The urgency of climate change demands a greater understanding of our climate system, not only by the leaders of today, but by the scientists, policy makers, and citizens of tomorrow. Unfortunately, a large segment of the population currently possesses inadequate knowledge of climate science. In direct response to a need for greater scientific literacy with respect to climate science, researchers from Appalachian State University's Appalachian Atmospheric Interdisciplinary Research (AppalAIR) group, with support from NASA, have developed CAN-DOO: the Climate Action Network through Direct Observations and Outreach. CAN-DOO addresses climate science literacy by 1) Developing the infrastructure for sustaining and expanding public outreach through long-term climate measurements capable of complementing existing NASA measurements, 2) Enhancing public awareness of climate science and NASA's role in advancing our understanding of the Earth System, and 3) Introducing Science, Technology, Engineering, and Mathematics principles to homeschooled, public school, and Appalachian State University students through applied climate science activities. Project partners include the Grandfather Mountain Stewardship Foundation, Pisgah Astronomical Research Institute, and local elementary schools. In partnership with Grandfather Mountain, climate science awareness is promoted through citizen science activities, interactive public displays, and staff training. CAN-DOO engages students by involving them in the entire scientific investigative process as applied to climate science. We introduce local elementary and middle school students, homeschooled students throughout North Carolina, and undergraduate students in a new Global Climate Change course and select other courses at Appalachian State University to instrument assembly, measurement techniques, data collection, hypothesis testing, and drawing conclusions. Results are placed in the proper context via comparisons with other student

Remote sensing of reconnection via ARTEMIS dual-spacecraft observations

NASA Astrophysics Data System (ADS)

Kiehas, Stefan; Angelopoulos, Vassilis; Runov, Andrei; Li, Shan-Shan

2013-04-01

Each month the two ARTEMIS probes spend about four days in the Earth's magnetotail near lunar orbit. Due to the near-equatorial orbit, the probes spend a considerable time near and inside the plasma sheet. This allows us to investigate large-scale effects of reconnection, such as flux ropes and high-speed flows, utilizing dual-probe observations on a regular basis. On August 31, 2012 around 03:00 UT, the ARTEMIS probes were separated by only 350 km in X_GSW and 0.6 (1) RE in Y_GSW (Z_GSW), where GSW denotes the Geocentric Solar Wind coordinate system, which x-axis is antiparallel to the solar wind flow direction. The two probes observe several TCRs and flux ropes. The inter-spacecraft separation allows us to determine the size of these structures to be not more than 6 RE in z. Counterstreaming beams observed by both probes indicate the simultaneous activity of two X-lines, earthward and tailward of the probes, respectively.

An observation related to directional attenuation of SKS waves propagating in anisotropic media

NASA Astrophysics Data System (ADS)

Zhao, Liang; Xue, Mei

2015-04-01

Azimuthal anisotropy of attenuation is a physical phenomenon related to the directional change of attenuation. This study examines the frequency properties and directional attenuation of SKS waves. The directional frequency-dependent characteristics of SKS waves are investigated in the frequency band of 0.02-0.5 Hz using data from 53 permanent seismic stations located throughout the northern Yangtze Craton, the southern North China Craton and adjacent areas. In addition to normal splitting behavior, the analysis reveals that many SKS splitting measurements exhibit a lemniscate shape, reflecting frequency differences along fast and slow polarization directions. Frequency analysis shows that spectral ratios between fast/slow components of the lemniscate-type splitting results fluctuate strongly in a higher frequency band of 0.2-0.5 Hz, and fluctuate less within the main frequency band of 0.02-0.2 Hz. For each station, the ratio of the peak amplitude of the fast/slow components can be represented as a cotangential function of event backazimuth multiplying with a constant = 0.42 ± 0.10. This transformation shows that the regional average angles consistently fall within the relatively narrow range of -46.5 ± 3° with respect to the north, suggesting that a regional tectonic controlling factor dictates the relatively uniform directional attenuation of SKS waves within the frequency band of 0.02-0.2 Hz. Further analysis is performed by projecting the SKS waves onto the components along and perpendicular to the regional average angles. The calculation also shows that, in the 0.02-0.2 Hz band, the relationship between amplitude ratio and event backazimuth matches a cotangential functions with the same best matching angles and constant a < 1. Synthetic calculations demonstrate that although different filters influence the splitting parameters, attenuation anisotropy cannot be explained by elastic anisotropic media, including multilayer anisotropy and anisotropy with a

Copernicus observations of interstellar matter in the direction of HR 1099

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Weiler, E. J.

1978-01-01

Results are reported for high-resolution Copernicus U1 and V2 scans of the bright RS CVn spectroscopic binary HR 1099. The observations reveal strong UV emission lines at L-alpha and Mg II h and k from the stars as well as interstellar H I and D I L-alpha absorption lines and interstellar Mg II h and k absorption in the direction of the binary system. Column densities, bulk velocities, and temperatures are derived for the interstellar features. A comparison of the derived number density of interstellar H I with data for the nearby star Epsilon Eri indicates an inhomogeneous distribution of interstellar hydrogen along the line of sight. The range of values obtained for the D/H ratio is shown to be consistent with results of other studies. A depletion factor of at least 5 with respect to the solar abundance is estimated for the interstellar magnesium.

Gossip as an alternative for direct observation in games of indirect reciprocity.

PubMed

Sommerfeld, Ralf D; Krambeck, Hans-Jürgen; Semmann, Dirk; Milinski, Manfred

2007-10-30

Communication about social topics is abundant in human societies, and many functions have been attributed to such gossiping. One of these proposed functions is the management of reputations. Reputation by itself has been shown to have a strong influence on cooperation dynamics in games of indirect reciprocity, and this notion helps to explain the observed high level of cooperation in humans. Here we designed a game to test a widespread assumption that gossip functions as a vector for the transmission of social information. This empirical study (with 14 groups of nine students each) focuses on the composition of gossip, information transfer by gossip, and the behavior based on gossip information. We show that gossip has a strong influence on the resulting behavior even when participants have access to the original information (i.e., direct observation) as well as gossip about the same information. Thus, it is evident that gossip has a strong manipulative potential. Furthermore, gossip about cooperative individuals is more positive than gossip about uncooperative individuals, gossip comments transmit social information successfully, and cooperation levels are higher when people encounter positive compared with negative gossip.

Gossip as an alternative for direct observation in games of indirect reciprocity

PubMed Central

Sommerfeld, Ralf D.; Krambeck, Hans-Jürgen; Semmann, Dirk; Milinski, Manfred

2007-01-01

Communication about social topics is abundant in human societies, and many functions have been attributed to such gossiping. One of these proposed functions is the management of reputations. Reputation by itself has been shown to have a strong influence on cooperation dynamics in games of indirect reciprocity, and this notion helps to explain the observed high level of cooperation in humans. Here we designed a game to test a widespread assumption that gossip functions as a vector for the transmission of social information. This empirical study (with 14 groups of nine students each) focuses on the composition of gossip, information transfer by gossip, and the behavior based on gossip information. We show that gossip has a strong influence on the resulting behavior even when participants have access to the original information (i.e., direct observation) as well as gossip about the same information. Thus, it is evident that gossip has a strong manipulative potential. Furthermore, gossip about cooperative individuals is more positive than gossip about uncooperative individuals, gossip comments transmit social information successfully, and cooperation levels are higher when people encounter positive compared with negative gossip. PMID:17947384

Tests for a disease-susceptibility locus allowing for an inbreeding coefficient (F).

PubMed

Song, Kijoung; Elston, Robert C

2003-11-01

We begin by discussing the false positive test results that arise because of cryptic relatedness and population substructure when testing a disease susceptibility locus. We extend and evaluate the Hardy-Weinberg disequilibrium (HWD) method, allowing for an inbreeding coefficient (F) in a similar way that Devlin and Roeder (1999) allowed for inbreeding in a case-control study. Then we compare the HWD measure and the common direct measure of linkage disequilibrium, both when there is no population substructure (F = 0) and when there is population substructure (F not = 0), for a single marker. The HWD test statistic gives rise to false positives caused by population stratification. These false positives can be controlled by adjusting the test statistic for the amount of variance inflation caused by the inbreeding coefficient (F). The power loss for the HWD test that arises when controlling for population structure is much less than that which arises for the common direct measure of linkage disequilibrium. However, in the multiplicative model, the HWD test has virtually no power even when allowing for non-zero F.

Evaluation of medical management during a mass casualty incident exercise: an objective assessment tool to enhance direct observation.

PubMed

Ingrassia, Pier Luigi; Prato, Federico; Geddo, Alessandro; Colombo, Davide; Tengattini, Marco; Calligaro, Sara; La Mura, Fabrizio; Franc, Jeffrey Michael; Della Corte, Francesco

2010-11-01

Functional exercises represent an important link between disaster planning and disaster response. Although these exercises are widely performed, no standardized method exists for their evaluation. To describe a simple and objective method to assess medical performance during functional exercise events. An evaluation tool comprising three data fields (triage, clinical maneuvers, and radio usage), accompanied by direct anecdotal observational methods, was used to evaluate a large functional mass casualty incident exercise. Seventeen medical responders managed 112 victims of a simulated building explosion. Although 81% of the patients were assigned the appropriate triage codes, evacuation from the site did not follow in priority. Required maneuvers were performed correctly in 85.2% of airway maneuvers and 78.7% of breathing maneuvers, however, significant under-treatment occurred, possibly due to equipment shortages. Extensive use of radio communication was documented. In evaluating this tool, the structured markers were informative, but further information provided by direct observation was invaluable. A three-part tool (triage, medical maneuvers, and radio usage) can provide a method to evaluate functional mass casualty incident exercises, and is easily implemented. For the best results, it should be used in conjunction with direct observation. The evaluation tool has great potential as a reproducible and internationally recognized tool for evaluating disaster management exercises. Copyright © 2010 Elsevier Inc. All rights reserved.

Biases and systematics in the observational derivation of galaxy properties: comparing different techniques on synthetic observations of simulated galaxies

NASA Astrophysics Data System (ADS)

Guidi, Giovanni; Scannapieco, Cecilia; Walcher, C. Jakob

2015-12-01

We study the sources of biases and systematics in the derivation of galaxy properties from observational studies, focusing on stellar masses, star formation rates, gas and stellar metallicities, stellar ages, magnitudes and colours. We use hydrodynamical cosmological simulations of galaxy formation, for which the real quantities are known, and apply observational techniques to derive the observables. We also analyse biases that are relevant for a proper comparison between simulations and observations. For our study, we post-process the simulation outputs to calculate the galaxies' spectral energy distributions (SEDs) using stellar population synthesis models and also generate the fully consistent far-UV-submillimetre wavelength SEDs with the radiative transfer code SUNRISE. We compared the direct results of simulations with the observationally derived quantities obtained in various ways, and found that systematic differences in all studied galaxy properties appear, which are caused by: (1) purely observational biases, (2) the use of mass-weighted and luminosity-weighted quantities, with preferential sampling of more massive and luminous regions, (3) the different ways of constructing the template of models when a fit to the spectra is performed, and (4) variations due to different calibrations, most notably for gas metallicities and star formation rates. Our results show that large differences can appear depending on the technique used to derive galaxy properties. Understanding these differences is of primary importance both for simulators, to allow a better judgement of similarities and differences with observations, and for observers, to allow a proper interpretation of the data.

Directed flux motor

NASA Technical Reports Server (NTRS)

Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

2011-01-01

A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

Remote and In Situ Observations of an Unusual Earth-Directed Coronal Mass Ejection from Multiple Viewpoints

NASA Technical Reports Server (NTRS)

Nieves-Chinchilla, T.; Colaninno, R.; Vourlidas, A.; Szabo, A.; Lepping, R. P.; Boardsen, S. A.; Anderson, B. J.; Korth, H.

2012-01-01

During June 16-21, 2010, an Earth-directed Coronal Mass Ejection (CME) event was observed by instruments onboard STEREO, SOHO, MESSENGER and Wind. This event was the first direct detection of a rotating CME in the middle and outer corona. Here, we carry out a comprehensive analysis of the evolution of the CME in the interplanetary medium comparing in-situ and remote observations, with analytical models and three-dimensional reconstructions. In particular, we investigate the parallel and perpendicular cross section expansion of the CME from the corona through the heliosphere up to 1 AU. We use height-time measurements and the Gradual Cylindrical Shell (GCS) technique to model the imaging observations, remove the projection effects, and derive the 3-dimensional extent of the event. Then, we compare the results with in-situ analytical Magnetic Cloud (MC) models, and with geometrical predictions from past works. We nd that the parallel (along the propagation plane) cross section expansion agrees well with the in-situ model and with the Bothmer & Schwenn [1998] empirical relationship based on in-situ observations between 0.3 and 1 AU. Our results effectively extend this empirical relationship to about 5 solar radii. The expansion of the perpendicular diameter agrees very well with the in-situ results at MESSENGER ( 0:5 AU) but not at 1 AU. We also find a slightly different, from Bothmer & Schwenn [1998], empirical relationship for the perpendicular expansion. More importantly, we find no evidence that the CME undergoes a significant latitudinal over-expansion as it is commonly assumed

Validity and feasibility of the EMG direct observation tool (EMG-DOT).

PubMed

Leep Hunderfund, Andrea N; Rubin, Devon I; Laughlin, Ruple S; Sorenson, Eric J; Watson, James C; Jones, Lyell K; Juul, Dorthea; Park, Yoon Soo

2016-04-26

To develop a new workplace-based EMG direct observation tool (EMG-DOT) and gather validity evidence supporting its use for assessing electrodiagnostic skills among postgraduate medical trainees. The EMG-DOT was developed by experts using an iterative process. Validity evidence from content, response process, internal structure, relations to other variables, and consequences of testing was collected during the 2013-2014 academic year. Of 3,412 studies performed by trainees during the study period, 299 (9%) were assessed using the EMG-DOT. Of these, 203 (68%) involved a physician rater and 96 (32%) involved a technician rater. The 14-item EMG-DOT had excellent internal-consistency reliability (Cronbach α 0.94). Correlations between individual items and criterion-referenced global ratings of performance ranged from 0.36 to 0.72 (all p < 0.001). Mean total scores increased from 70% to 80% over 4 months of the EMG rotation (p < 0.001) despite a corresponding significant increase in case complexity (0.21-0.74 on a 3-point rating scale; p < 0.001). Trainees reported that the observational assessment exercise improved their knowledge or skills in 82% of encounters (188/230) and that feedback generated by the EMG-DOT improved the quality of care provided to patients in 58% (133/230). Trainees were "satisfied" or "very satisfied" with the observational assessment exercise in 96% of encounters (234/243). This study provides validity evidence supporting the use of EMG-DOT scores to assess electrodiagnostic skills of residents and fellows. The EMG-DOT can be used to inform milestone-based assessments of trainee performance in neurology, child neurology, physical medicine and rehabilitation, neuromuscular, and clinical neurophysiology training programs. © 2016 American Academy of Neurology.

Development of a direct observation Measure of Environmental Qualities of Activity Settings.

PubMed

King, Gillian; Rigby, Patty; Batorowicz, Beata; McMain-Klein, Margot; Petrenchik, Theresa; Thompson, Laura; Gibson, Michelle

2014-08-01

The aim of this study was to develop an observer-rated measure of aesthetic, physical, social, and opportunity-related qualities of leisure activity settings for young people (with or without disabilities). Eighty questionnaires were completed by sets of raters who independently rated 22 community/home activity settings. The scales of the 32-item Measure of Environmental Qualities of Activity Settings (MEQAS; Opportunities for Social Activities, Opportunities for Physical Activities, Pleasant Physical Environment, Opportunities for Choice, Opportunities for Personal Growth, and Opportunities to Interact with Adults) were determined using principal components analyses. Test-retest reliability was determined for eight activity settings, rated twice (4-6wk interval) by a trained rater. The factor structure accounted for 80% of the variance. The Kaiser-Meyer-Olkin Measure of Sampling Adequacy was 0.73. Cronbach's alphas for the scales ranged from 0.76 to 0.96, and interrater reliabilities (ICCs) ranged from 0.60 to 0.93. Test-retest reliabilities ranged from 0.70 to 0.90. Results suggest that the MEQAS has a sound factor structure and preliminary evidence of internal consistency, interrater, and test-retest reliability. The MEQAS is the first observer-completed measure of environmental qualities of activity settings. The MEQAS allows researchers to assess comprehensively qualities and affordances of activity settings, and can be used to design and assess environmental qualities of programs for young people. © 2014 Mac Keith Press.

Establishing the Feasibility of Direct Observation in the Assessment of Tics in Children with Chronic Tic Disorders

ERIC Educational Resources Information Center

Himle, Michael B.; Chang, Susanna; Woods, Douglas W.; Pearlman, Amanda; Buzzella, Brian; Bunaciu, Liviu; Piacentini, John C.

2006-01-01

Behavior analysis has been at the forefront in establishing effective treatments for children and adults with chronic tic disorders. As is customary in behavior analysis, the efficacy of these treatments has been established using direct-observation assessment methods. Although behavior-analytic treatments have enjoyed acceptance and integration…

Direct Observation of Zhang-Li Torque Expansion of Magnetic Droplet Solitons

NASA Astrophysics Data System (ADS)

Chung, Sunjae; Le, Q. Tuan; Ahlberg, Martina; Awad, Ahmad A.; Weigand, Markus; Bykova, Iuliia; Khymyn, Roman; Dvornik, Mykola; Mazraati, Hamid; Houshang, Afshin; Jiang, Sheng; Nguyen, T. N. Anh; Goering, Eberhard; Schütz, Gisela; Gräfe, Joachim; Åkerman, Johan

2018-05-01

Magnetic droplets are nontopological dynamical solitons that can be nucleated in nanocontact based spin torque nano-oscillators (STNOs) with perpendicular magnetic anisotropy free layers. While theory predicts that the droplet should be of the same size as the nanocontact, its inherent drift instability has thwarted attempts at observing it directly using microscopy techniques. Here, we demonstrate highly stable magnetic droplets in all-perpendicular STNOs and present the first detailed droplet images using scanning transmission X-ray microscopy. In contrast to theoretical predictions, we find that the droplet diameter is about twice as large as the nanocontact. By extending the original droplet theory to properly account for the lateral current spread underneath the nanocontact, we show that the large discrepancy primarily arises from current-in-plane Zhang-Li torque adding an outward pressure on the droplet perimeter. Electrical measurements on droplets nucleated using a reversed current in the antiparallel state corroborate this picture.

Unveiling the hidden supernova population in local LIRGs with NIR/Radio observations

NASA Astrophysics Data System (ADS)

Herrero-Illana, R.; Pérez-Torres, M. A.; Alberdi, A.

2013-05-01

The dust enshrouded environments of Luminous Infrared Galaxies (LIRGs), and especially of their nuclear regions, prevents the direct detection of supernovae in the optical. Radio observations are unaffected by dust extinction, allowing for the detection of most of these supernovae, thus probing their massive star formation rate. In addition, complementary observations in the near IR can help us to understand the nature of these phenomena and derive properties of the regions where they occur.

Method for observing phase objects without halos and directional shadows

NASA Astrophysics Data System (ADS)

Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi

2015-03-01

A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.

Adjustable Parameter-Based Distributed Fault Estimation Observer Design for Multiagent Systems With Directed Graphs.

PubMed

Zhang, Ke; Jiang, Bin; Shi, Peng

2017-02-01

In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.

The bi-directional leader observation in positive cloud-to-ground lightning flashes during summer thunderstorm season

NASA Astrophysics Data System (ADS)

Nakamura, Y.; Manabu, A.; Morimoto, T.; Ushio, T.; Kawasaki, Z.; Miki, M.; Shimizu, M.

2009-12-01

In this paper, we present observations of positive cloud-to-ground (+CG) lightning flashes obtained with the VHF BDITF (VHF Broadband Digital InTerFerometer) and the ALPS (Automatic Lightning Discharge Progressing Feature Observation System). The VHF BDITF observed two- (2D) and three-dimensional (3D) developments of lightning flashes with high time resolution. The ALPS observed the luminous propagation of the local process at low altitudes within its observational range. At 2028:59 JST on 8 August, 2008, we observed the 3D spatiotemporal development channels of +CG lightning flash with the VHF BDITF and the RS with the lightning location and protection (LLP) system. This flash is divided before and after the RS. In the former stage, the in-cloud negative breakdown (NB) progress about 15 km horizontally between 6 and 10 km high. The LLP system detects the RS near the initiation point of that negative breakdown (NB) at the end of the former stage. In the latter stage, the new NB runs through the same path as the first NB before the RS. The luminous intensity of the RS near the ground obtained with the ALPS is synchronized with the development of the new NB. The time variation of luminous intensity by the ALPS has two peaks. The time difference of these peaks is corresponding to the blank of the VHF radiation. Since the new NB following the RS runs through the path of the first NB, the positive breakdown (PB), which is not visualized by the VHF BDITF, could be considered to progress from the starting point of the first NB and touches to the ground. The RS current propagates and penetrates in the opposite direction as visualized subsequent NB. This suggests the first NB and the PB progress together. This +CG lightning flash has the bi-directional leader. To assume the path of the PB is straight line, the velocity of the PB is about 4 × 104 m/s.

Direct observations of evolving subglacial drainage beneath the Greenland Ice Sheet.

PubMed

Andrews, Lauren C; Catania, Ginny A; Hoffman, Matthew J; Gulley, Jason D; Lüthi, Martin P; Ryser, Claudia; Hawley, Robert L; Neumann, Thomas A

2014-10-02

Seasonal acceleration of the Greenland Ice Sheet is influenced by the dynamic response of the subglacial hydrologic system to variability in meltwater delivery to the bed via crevasses and moulins (vertical conduits connecting supraglacial water to the bed of the ice sheet). As the melt season progresses, the subglacial hydrologic system drains supraglacial meltwater more efficiently, decreasing basal water pressure and moderating the ice velocity response to surface melting. However, limited direct observations of subglacial water pressure mean that the spatiotemporal evolution of the subglacial hydrologic system remains poorly understood. Here we show that ice velocity is well correlated with moulin hydraulic head but is out of phase with that of nearby (0.3-2 kilometres away) boreholes, indicating that moulins connect to an efficient, channelized component of the subglacial hydrologic system, which exerts the primary control on diurnal and multi-day changes in ice velocity. Our simultaneous measurements of moulin and borehole hydraulic head and ice velocity in the Paakitsoq region of western Greenland show that decreasing trends in ice velocity during the latter part of the melt season cannot be explained by changes in the ability of moulin-connected channels to convey supraglacial melt. Instead, these observations suggest that decreasing late-season ice velocity may be caused by changes in connectivity in unchannelized regions of the subglacial hydrologic system. Understanding this spatiotemporal variability in subglacial pressures is increasingly important because melt-season dynamics affect ice velocity beyond the conclusion of the melt season.

Direct quantum process tomography via measuring sequential weak values of incompatible observables.

PubMed

Kim, Yosep; Kim, Yong-Su; Lee, Sang-Yun; Han, Sang-Wook; Moon, Sung; Kim, Yoon-Ho; Cho, Young-Wook

2018-01-15

The weak value concept has enabled fundamental studies of quantum measurement and, recently, found potential applications in quantum and classical metrology. However, most weak value experiments reported to date do not require quantum mechanical descriptions, as they only exploit the classical wave nature of the physical systems. In this work, we demonstrate measurement of the sequential weak value of two incompatible observables by making use of two-photon quantum interference so that the results can only be explained quantum physically. We then demonstrate that the sequential weak value measurement can be used to perform direct quantum process tomography of a qubit channel. Our work not only demonstrates the quantum nature of weak values but also presents potential new applications of weak values in analyzing quantum channels and operations.

Treatment of tuberculosis in a rural area of Haiti: directly observed and non-observed regimens. The experience of H pital Albert Schweitzer.

PubMed

Ollé-Goig, J E; Alvarez, J

2001-02-01

Artibonite Valley, a rural area in Haiti. To evaluate a tuberculosis control program in rural Haiti and to compare two strategies for treatment implemented in two areas that were not chosen at random: treatment delivered at the patients' homes observed by former tuberculosis patients (DOT), and non observed treatment (non-DOT). Retrospective analysis of the clinical records of adult patients diagnosed with tuberculosis at H pital Albert Schweitzer in Deschapelles, Haiti, during 1994-1995. There were 143 patients in the non-DOT group and 138 patients in the DOT group. The results of treatment were significantly different: in the non-DOT group 29% defaulted, 12% died and 58% had a successful outcome; in the DOT group 7% defaulted (P < 0.01), 4% died (P = 0.01) and 87% had a successful outcome (P < 0.01). These differences are also significant when considering only human immunodeficiency virus (HIV) infected patients (defaulted P < 0.01; died P = 0.09; successful outcome P < 0.01). Delivering treatment in patients' homes with direct observation by former tuberculosis patients can achieve good results, even in an area of extreme poverty and high rates of HIV infection. In this population the number of patients who are able to complete their treatment without observed administration is far from optimal.

Direct-to-consumer advertising affects provider / patient relationship.

PubMed

1998-12-01

Family planning program clients are increasingly seeking oral contraceptive pills by brand name. Direct-to-consumer ads have spurred this recent increase in brand-specific requests for prescription drugs. While print consumer pitches for prescription drugs have been around for a long time, proposed guidance issued by the US Food and Drug Administration (FDA) in August 1997 allows pharmaceutical companies to more easily broadcast product claim commercials on television and radio. Now, half of all direct-to-consumer advertising dollars spent by pharmaceutical companies during January-February 1998 were directed to television ads, almost twice the share spent upon television last year. Last year, pharmaceutical companies spent more than $1 billion on direct-to-consumer advertising. The effects of this new policy are presenting in providers' offices. Before the FDA guidance, 41% of physicians participating in a national survey observed an increase in patients' requests for brand name drugs. However, since the change, 65% surveyed to date have observed an increase in such requests. With the increase in advertising comes a potential for violations of the US Food, Drug, and Cosmetic Act, which regulates provider and consumer prescription drug advertising. 125 companies were cited for violations in 1998, 6 specifically for violations connected with contraceptive information they disseminated.

Observing Mars with Schiaparelli's telescope

NASA Astrophysics Data System (ADS)

Bernagozzi, Andrea; Testa, Antonella; Tucci, Pasquale

2004-03-01

We have taken the occasion of the 2003 Mars' opposition to carry out observations of the red planet with the 218 mm Merz refractor, built in the 1863-1865, recently restored, used by Giovanni Virginio Schiaparelli to observe Mars from the opposition of August 1877 until that one of the 1883-'84. In the occasion we launched a 5 days initiative of dissemination of scientific culture addressed to students and public at large. We organized direct observations and adapted a webcam to the ancient instrument. The images were sent to Milanese Planetarium where about 300 people, every night, could participate to the manifestation. Moreover a big screen was arranged in the garden around the Planetarium in order to allow other people to participate. The projection of the images was part of a 2 hours program of short lectures on the historical and current aspects of Mars. This initiative was successful: but what about scientific culture? What kind of scientific information did the public perceive?

Observation of partial relaxation mechanisms via anisotropic strain relief on epitaxial islands using semiconductor nanomembranes

NASA Astrophysics Data System (ADS)

Rosa, Barbara L. T.; Marçal, Lucas A. B.; Ribeiro Andrade, Rodrigo; Dornellas Pinto, Luciana; Rodrigues, Wagner N.; Lustoza Souza, Patrícia; Pamplona Pires, Mauricio; Wagner Nunes, Ricardo; Malachias, Angelo

2017-07-01

In this work we attempt to directly observe anisotropic partial relaxation of epitaxial InAs islands using transmission electron microscopy (TEM) and synchrotron x-ray diffraction on a 15 nm thick InAs:GaAs nanomembrane. We show that under such conditions TEM provides improved real-space statistics, allowing the observation of partial relaxation processes that were not previously detected by other techniques or by usual TEM cross section images. Besides the fully coherent and fully relaxed islands that are known to exist above previously established critical thickness, we prove the existence of partially relaxed islands, where incomplete 60° half-loop misfit dislocations lead to a lattice relaxation along one of the <110> directions, keeping a strained lattice in the perpendicular direction. Although individual defects cannot be directly observed, their implications to the resulting island registry are identified and discussed within the frame of half-loops propagations.

Observation of partial relaxation mechanisms via anisotropic strain relief on epitaxial islands using semiconductor nanomembranes.

PubMed

Rosa, Barbara L T; Marçal, Lucas A B; Andrade, Rodrigo Ribeiro; Pinto, Luciana Dornellas; Rodrigues, Wagner N; Souza, Patrícia Lustoza; Pires, Mauricio Pamplona; Nunes, Ricardo Wagner; Malachias, Angelo

2017-07-28

In this work we attempt to directly observe anisotropic partial relaxation of epitaxial InAs islands using transmission electron microscopy (TEM) and synchrotron x-ray diffraction on a 15 nm thick InAs:GaAs nanomembrane. We show that under such conditions TEM provides improved real-space statistics, allowing the observation of partial relaxation processes that were not previously detected by other techniques or by usual TEM cross section images. Besides the fully coherent and fully relaxed islands that are known to exist above previously established critical thickness, we prove the existence of partially relaxed islands, where incomplete 60° half-loop misfit dislocations lead to a lattice relaxation along one of the 〈110〉 directions, keeping a strained lattice in the perpendicular direction. Although individual defects cannot be directly observed, their implications to the resulting island registry are identified and discussed within the frame of half-loops propagations.

Fundamental Physics from Observations of White Dwarf Stars

NASA Astrophysics Data System (ADS)

Bainbridge, M. B.; Barstow, M. A.; Reindl, N.; Barrow, J. D.; Webb, J. K.; Hu, J.; Preval, S. P.; Holberg, J. B.; Nave, G.; Tchang-Brillet, L.; Ayres, T. R.

2017-03-01

Variation in fundamental constants provide an important test of theories of grand unification. Potentially, white dwarf spectra allow us to directly observe variation in fundamental constants at locations of high gravitational potential. We study hot, metal polluted white dwarf stars, combining far-UV spectroscopic observations, atomic physics, atmospheric modelling and fundamental physics, in the search for variation in the fine structure constant. This registers as small but measurable shifts in the observed wavelengths of highly ionized Fe and Ni lines when compared to laboratory wavelengths. Measurements of these shifts were performed by Berengut et al (2013) using high-resolution STIS spectra of G191-B2B, demonstrating the validity of the method. We have extended this work by; (a) using new (high precision) laboratory wavelengths, (b) refining the analysis methodology (incorporating robust techniques from previous studies towards quasars), and (c) enlarging the sample of white dwarf spectra. A successful detection would be the first direct measurement of a gravitational field effect on a bare constant of nature. We describe our approach and present preliminary results.

The New Worlds Observer: A New Approach to Observing Extrasolar Planets

NASA Astrophysics Data System (ADS)

Cash, W.; Wilkinson, E.; Green, J.; Kasdin, J.; Spergel, D.; Turner, E.; Vanderbei, R.; Seager, S.; Stern, A.; Kilston, S.; Leiber, J.

2003-12-01

Direct observation of planets around other stars has been hindered primarily by the spatial proximity of their parent stars. Diffraction and scattering swamp the signal from the planet, which is typically billions of times fainter. We present an approach which has the potential to sidestep these problems. The New Worlds Observer was proposed to NASA last summer for a concept study as a Life Finder Mission to perform spectroscopy of terrestrial planets at 10pc. It consists of two spacecraft separated by 180,00km. The first craft, the starshade, features a deployable dark sheet hundreds of meters across and an aperture approximately 10m in diameter, specially shaped to suppress diffraction. At the focal plane of this pinhole camera flies a 10m diameter, one arcsecond quality Cassegrain telescope. If the telescope is placed where the pinhole image of a planet falls, the diffracted light from the star is suppressed, so only planet light enters the telescope. This system will allow sensitive observations anywhere from the far ultraviolet to the near infrared. Accompanying posters at this meeting will present science simulations and more details on the starshade design.

Direct observations of the Antarctic Slope Current transport at 113°E

NASA Astrophysics Data System (ADS)

Peña-Molino, B.; McCartney, M. S.; Rintoul, S. R.

2016-10-01

The Antarctic Slope Current (ASC), defined here as the region of westward flow along the continental slope off Antarctica, forms the southern limb of the subpolar gyres. It regulates the exchange of water across the shelf break and provides a path for interbasin westward transport. Despite its significance, the ASC remains largely unobserved around most of the Antarctic continent. Here we present direct velocity observations from a 17 month current meter moored array deployed across the continental slope between the 1000 and the 4200 m isobaths, in the southeastern Indian Ocean near 113°E. The observed time-mean flow consists of a surface-intensified jet associated with the Antarctic Slope Front (ASF) and a broader bottom-intensified westward flow that extends out to approximately the 4000 m isobath and is strongest along the upper slope. The time-mean transport of the ASC is -29.2 Sv. Fluctuations in the transport are large, typically exceeding the mean by a factor of 2. They are mainly due to changes in the northward extent of the current over the lower slope. However, seasonal changes in the wind also drive variations in the transport of the ASF and the flow in the upper slope. Both mean and variability are largely barotropic, thus invisible to traditional geostrophic methods.

NGC 2024: Far-infrared and radio molecular observations

NASA Technical Reports Server (NTRS)

Thronson, H. A., Jr.; Lada, C. J.; Schwartz, P. R.; Smith, H. A.; Smith, J.; Glaccum, W.; Harper, D. A.; Loewenstein, R. F.

1984-01-01

Far infrared continuum and millimeter wave molecular observations are presented for the infrared and radio source NGC 2024. The measurements are obtained at relatively high angular resolution, enabling a description of the source energetics and mass distribution in greater detail than previously reported. The object appears to be dominated by a dense ridge of material, extended in the north/south direction and centered on the dark lane that is seen in visual photographs. Maps of the source using the high density molecules CS and HCN confirm this picture and allow a description of the core structure and molecular abundances. The radio molecular and infrared observations support the idea that an important exciting star in NGC 2024 has yet to be identified and is centered on the dense ridge about 1' south of the bright mid infrared source IRS 2. The data presented here allows a presentation of a model for the source.

Evolution of allowable stresses in shear for lumber

Treesearch

Robert L. Ethington; William L. Galligan; Henry M. Montrey; Alan D. Freas

1979-01-01

This paper surveys research leading to allowable shear stress parallel to grain for lumber. In early flexure tests of lumber, some pieces failed in shear. The estimated shear stress at time of failure was generally lower than shear strength measured on small, clear, straight-grained specimens. This and other engineering observations gave rise to adjustments that...

A Genetic Algorithm Method for Direct estimation of paleostress states from heterogeneous fault-slip observations

NASA Astrophysics Data System (ADS)

Srivastava, D. C.

2016-12-01

A Genetic Algorithm Method for Direct estimation of paleostress states from heterogeneous fault-slip observationsDeepak C. Srivastava, Prithvi Thakur and Pravin K. GuptaDepartment of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee 247667, India. Abstract Paleostress estimation from a group of heterogeneous fault-slip observations entails first the classification of the observations into homogeneous fault sets and then a separate inversion of each homogeneous set. This study combines these two issues into a nonlinear inverse problem and proposes a heuristic search method that inverts the heterogeneous fault-slip observations. The method estimates different paleostress states in a group of heterogeneous fault-slip observations and classifies it into homogeneous sets as a byproduct. It uses the genetic algorithm operators, elitism, selection, encoding, crossover and mutation. These processes translate into a guided search that finds successively fitter solutions and operate iteratively until the termination criteria is met and the globally fittest stress tensors are obtained. We explain the basic steps of the algorithm on a working example and demonstrate validity of the method on several synthetic and a natural group of heterogeneous fault-slip observations. The method is independent of any user-defined bias or any entrapment of solution in a local optimum. It succeeds even in the difficult situations where other classification methods are found to fail.

Characteristics of Interruptions During Medication Administration:An Integrative Review of Direct Observational Studies.

PubMed

Schroers, Ginger

2018-06-26

The purpose of this review was to synthesize and summarize data gathered by direct observation of the characteristics of interruptions in the context of nursing medication administration in hospital settings. Interruptions are prevalent during the medication administration process performed by nurses in hospital settings and have been found to be associated with an increase in frequency and severity of nursing medication administration errors. In addition, interruptions decrease task efficiency, leading to longer medication administration completion times. Integrative review. The electronic databases Cumulative Index of Nursing and Allied Health Literature (CINAHL), PubMED, PsyARTICLES, and Google Scholar were searched using the terms "interruptions" AND "medication administration" AND "direct observation". Nine articles met the inclusion criteria. Interruptions are likely to occur at least once during nursing medication administration processes in hospital settings. This finding applies to medication administered to one patient, termed a medication pass, and medication administered to multiple patients, termed a mediation round. Interruptions are most commonly caused by another nurse, staff member, or are self-initiated, and last approximately one minute in length. A raised awareness among staff of the most common sources of interruptions may encourage changes that lead to a decrease in the occurrence of interruptions. In addition, nurse leaders can apply an understanding of the common characteristics of interruptions to guide research, policies, and educational methods aimed at interruption management strategies. The findings from this review can be used to guide the identification and development of targeted interventions and strategies that would have the most substantial impact to reduce and manage interruptions during medication administration. Interruption management strategies have the potential to lead to a decrease in medication errors and an increase in

Statistical distribution of wind speeds and directions globally observed by NSCAT

NASA Astrophysics Data System (ADS)

Ebuchi, Naoto

1999-05-01

In order to validate wind vectors derived from the NASA scatterometer (NSCAT), statistical distributions of wind speeds and directions over the global oceans are investigated by comparing with European Centre for Medium-Range Weather Forecasts (ECMWF) wind data. Histograms of wind speeds and directions are calculated from the preliminary and reprocessed NSCAT data products for a period of 8 weeks. For wind speed of the preliminary data products, excessive low wind distribution is pointed out through comparison with ECMWF winds. A hump at the lower wind speed side of the peak in the wind speed histogram is discernible. The shape of the hump varies with incidence angle. Incompleteness of the prelaunch geophysical model function, SASS 2, tentatively used to retrieve wind vectors of the preliminary data products, is considered to cause the skew of the wind speed distribution. On the contrary, histograms of wind speeds of the reprocessed data products show consistent features over the whole range of incidence angles. Frequency distribution of wind directions relative to spacecraft flight direction is calculated to assess self-consistency of the wind directions. It is found that wind vectors of the preliminary data products exhibit systematic directional preference relative to antenna beams. This artificial directivity is also considered to be caused by imperfections in the geophysical model function. The directional distributions of the reprocessed wind vectors show less directivity and consistent features, except for very low wind cases.

A general ligand design for gold catalysis allowing ligand-directed anti-nucleophilic attack of alkynes.

PubMed

Wang, Yanzhao; Wang, Zhixun; Li, Yuxue; Wu, Gongde; Cao, Zheng; Zhang, Liming

2014-04-07

Most homogenous gold catalyses demand ≥ 0.5 mol% catalyst loading. Owing to the high cost of gold, these reactions are unlikely to be applicable in medium- or large-scale applications. Here we disclose a novel ligand design based on the privileged (1,1'-biphenyl)-2-ylphosphine framework that offers a potentially general approach to dramatically lowering catalyst loading. In this design, an amide group at the 3'-position of the ligand framework directs and promotes nucleophilic attack at the ligand gold complex-activated alkyne, which is unprecedented in homogenous gold catalysis considering the spatial challenge of using ligand to reach anti-approaching nucleophile in a linear P-Au-alkyne centroid structure. With such a ligand, the gold(I) complex becomes highly efficient in catalysing acid addition to alkynes, with a turnover number up to 99,000. Density functional theory calculations support the role of the amide moiety in directing the attack of carboxylic acid via hydrogen bonding.

A General Ligand Design for Gold Catalysis allowing Ligand-Directed Anti Nucleophilic Attack of Alkynes

PubMed Central

Wang, Yanzhao; Wang, Zhixun; Li, Yuxue; Wu, Gongde; Cao, Zheng; Zhang, Liming

2014-01-01

Most homogenous gold catalyses demand ≥0.5 mol % catalyst loading. Due to the high cost of gold, these reactions are unlikely to be applicable in medium or large scale applications. Here we disclose a novel ligand design based on the privileged biphenyl-2-phosphine framework that offers a potentially general approach to dramatically lowering catalyst loading. In this design, an amide group at the 3’ position of the ligand framework directs and promotes nucleophilic attack at the ligand gold complex-activated alkyne, which is unprecedented in homogeneous gold catalysis considering the spatial challenge of using ligand to reach antiapproaching nucleophile in a linear P-Au-alkyne centroid structure. With such a ligand, the gold(I) complex becomes highly efficient in catalyzing acid addition to alkynes, with a turnover number up to 99,000. Density functional theory calculations support the role of the amide moiety in directing the attack of carboxylic acid via hydrogen bonding. PMID:24704803

Two radars for AIM mission: A direct observation of the asteroid's structure from deep interior to regolith

NASA Astrophysics Data System (ADS)

Herique, A.; Ciarletti, V.

2015-10-01

Our knowledge of the internal structure of asteroids is, so far, indirect - relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape their internal structures? Direct measurements are needed to provide answers that will directly improve our ability to understand and model the mechanisms driving Near Earth Asteroids (NEA) for the benefit of science as well as for planetary defense or exploration. Radar tomography is the only technique to characterize internal structure from decimetric scale to global scale. This paper reviews the benefits of direct measurement of the asteroid interior. Then the radar concepts for both deep interior and shallow subsurface are presented and the radar payload proposed for the AIDA/AIM mission is outlined.

Direct Observation of the BCC (100) Plane in Thin Films of Sphere-forming Diblock Copolymers

NASA Astrophysics Data System (ADS)

Ji, Shengxiang; Nagpal, Umang; Liao, Wen; de Pablo, Juan; Nealey, Paul

2010-03-01

In sphere-forming diblock copolymers, periodic arrays of spheres are arranged in a body-centred cubic (BCC) lattice structure in bulk. However, in thin films different surface morphologies were observed as a function of the film thickness, and the transition from the hexagonal array to the BCC (110) arrangement of spheres on film surfaces was located with respect to the increase of the film thickness. Here we report the first direct observation of the BCC (100) plane in thin films of poly (styrene-b-methyl methacrylate) diblock copolymers on homogeneous substrates. By balancing the surface energies of both blocks, the lower energy BCC (100) plane corresponding to a square arrangement of half spheres, formed on film surfaces when the film thickness was commensurate with the spacing, L100, between (100) planes or greater than 2 L100. A hexagonal arrangement of spheres was only observed when the thickness was less than 2 L100 and incommensurate with 1 L100. Monte Carlo (MC) simulation confirmed our experimental observation and was used to investigate the transition of the arrangement of spheres as a function of the film thickness.

Phase matching considerations in second harmonic generation from tissues: Effects on emission directionality, conversion efficiency and observed morphology

NASA Astrophysics Data System (ADS)

LaComb, Ronald; Nadiarnykh, Oleg; Townsend, Sallie S.; Campagnola, Paul J.

2008-04-01

We present a heuristic treatment which relates SHG image intensities, signal directionality, and observed morphology to the physical structure of collagen and cellulose fibrillar tissues. The SHG creation model is based upon relaxed phase matching conditions which account for dispersion, randomness, and axial momentum contributions from the media, and includes a mathematical treatment which relates SHG conversion efficiency to fibril diameter and packing through the inclusion of potential intensity amplification resultant from quasi-phase matching (QPM). A direct consequence of this theory is that SHG in biological tissues is not strictly a coherent process, and that the forward directed SHG has a longer coherence length than the backward component, Through this treatment, we show that the emission directionality and also conversion efficiency do not arise solely from the fibril size but also depend on packing density and order of the inter-fibril structure. We demonstrate these principles in comparing the SHG response in normal and Osteogenesis Imperfecta (OI) skin. We show that the observed directionality and decreased relative intensity in the diseased state is consistent with phase matching conditions arising from the decreased fibril size and more random assembly. We further use this theory to explain the differences in morphology seen in forward and backward collected SHG in fibrillar tissues (e.g., collagenous and cellulosic). Specifically, we attribute segmented appearance to destructive interference between small fibrils separated by less than the coherence length. We suggest the approach based on relaxed phasematching conditions is general in predicting the SHG response in tissues and may be broadly applicable in interpreting the SHG contrast for diagnostic applications.

Cross-Scale Observational Signatures of Magnetic Reconnection

NASA Technical Reports Server (NTRS)

Savage, Sabrina; Malaspina, David

2014-01-01

Magnetic reconnection is a significant mechanism for energy release across many astrophysical applications. In the solar atmosphere, reconnection is considered a primary contributor of flare evolution and coronal heating. Directly observing reconnection occurring in the solar atmosphere, however, is not trivial considering that the scale size of the diffusion region is magnitudes smaller than the observational capabilities of current instrumentation, and coronal magnetic field measurements are not currently sufficient to capture the process. Meanwhile, reconnection occurring in the Earth's magnetosphere transfers energy from the solar wind through a comparable process, although on vastly different scales. Magnetospheric measurements are made in situ rather than remotely; ergo, comparison of observations between the two regimes allows for potentially significant insight into reconnection as a stochastic and possibly turbulent process. We will present a set of observations from long-duration solar events and compare them to in situ measurements from the magnetosphere.

Cross-scale Observational Signatures of Magnetic Reconnection

NASA Astrophysics Data System (ADS)

Savage, S. L.; Malaspina, D.

2014-12-01

Magnetic reconnection is a significant mechanism for energy release across many astrophysical applications. In the solar atmosphere, reconnection is considered a primary contributor of flare evolution and coronal heating. Directly observing reconnection occurring in the solar atmosphere, however, is not trivial considering that the scale size of the diffusion region is magnitudes smaller than the observational capabilities of current instrumentation, and coronal magnetic field measurements are not currently sufficient to capture the process. Meanwhile, reconnection occurring in the Earth's magnetosphere transfers energy from the solar wind through a comparable process, although on vastly different scales. Magnetospheric measurements are made in situ rather than remotely; ergo, comparison of observations between the two regimes allows for potentially significant insight into reconnection as a stochastic and possibly turbulent process. We will present a set of observations from long-duration solar events and compare them to in situ measurements from the magnetosphere.

Simulated Milky Way analogues: implications for dark matter direct searches

NASA Astrophysics Data System (ADS)

Bozorgnia, Nassim; Calore, Francesca; Schaller, Matthieu; Lovell, Mark; Bertone, Gianfranco; Frenk, Carlos S.; Crain, Robert A.; Navarro, Julio F.; Schaye, Joop; Theuns, Tom

2016-05-01

We study the implications of galaxy formation on dark matter direct detection using high resolution hydrodynamic simulations of Milky Way-like galaxies simulated within the EAGLE and APOSTLE projects. We identify Milky Way analogues that satisfy observational constraints on the Milky Way rotation curve and total stellar mass. We then extract the dark matter density and velocity distribution in the Solar neighbourhood for this set of Milky Way analogues, and use them to analyse the results of current direct detection experiments. For most Milky Way analogues, the event rates in direct detection experiments obtained from the best fit Maxwellian distribution (with peak speed of 223-289 km/s) are similar to those obtained directly from the simulations. As a consequence, the allowed regions and exclusion limits set by direct detection experiments in the dark matter mass and spin-independent cross section plane shift by a few GeV compared to the Standard Halo Model, at low dark matter masses. For each dark matter mass, the halo-to-halo variation of the local dark matter density results in an overall shift of the allowed regions and exclusion limits for the cross section. However, the compatibility of the possible hints for a dark matter signal from DAMA and CDMS-Si and null results from LUX and SuperCDMS is not improved.

Simulated Milky Way analogues: implications for dark matter direct searches

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

Bozorgnia, Nassim; Calore, Francesca; Lovell, Mark

2016-05-01

We study the implications of galaxy formation on dark matter direct detection using high resolution hydrodynamic simulations of Milky Way-like galaxies simulated within the EAGLE and APOSTLE projects. We identify Milky Way analogues that satisfy observational constraints on the Milky Way rotation curve and total stellar mass. We then extract the dark matter density and velocity distribution in the Solar neighbourhood for this set of Milky Way analogues, and use them to analyse the results of current direct detection experiments. For most Milky Way analogues, the event rates in direct detection experiments obtained from the best fit Maxwellian distribution (withmore » peak speed of 223–289 km/s) are similar to those obtained directly from the simulations. As a consequence, the allowed regions and exclusion limits set by direct detection experiments in the dark matter mass and spin-independent cross section plane shift by a few GeV compared to the Standard Halo Model, at low dark matter masses. For each dark matter mass, the halo-to-halo variation of the local dark matter density results in an overall shift of the allowed regions and exclusion limits for the cross section. However, the compatibility of the possible hints for a dark matter signal from DAMA and CDMS-Si and null results from LUX and SuperCDMS is not improved.« less

Influence of Observed Diurnal Cycles of Aerosol Optical Depth on Aerosol Direct Radiative Effect

NASA Technical Reports Server (NTRS)

Arola, A.; Eck, T. F.; Huttunen, J.; Lehtinen, K. E. J.; Lindfors, A. V.; Myhre, G.; Smirinov, A.; Tripathi, S. N.; Yu, H.

2013-01-01

The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally.We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was

Administrative complexities for a European observational study despite directives harmonising requirements.

PubMed

Gülmez, Sinem Ezgi; Lignot-Maleyran, Séverine; de Vries, Corinne S; Sturkenboom, Miriam; Micon, Sophie; Hamoud, Fatima; Blin, Patrick; Moore, Nicholas

2012-08-01

For pharmacoepidemiological studies in Europe, accessing data should require only authorisation by the relevant data protections committees, as expected from the 1995 Data Protection Directive (95/46/EC). Our experience from a multinational observational study across seven European countries shows that this is certainly not the case. The study was a multicentre, multinational, case-population study in European liver transplant centres in seven countries, retrospectively evaluating a 3-year period. Before data collection started, the procedures to obtain the necessary authorisations for the participating countries were defined. In France, a single opinion from a single data protection committee was enough to start the study. In Italy, Portugal, Greece and the UK, there was a national authority, but the hospitals requested the approval by their local committees/bodies irrespective of whether the authorisation of the national committee came after or before that of local ones. In Ireland, only one hospital participated, and the opinion of its ethics committee was sufficient. In the Netherlands, the opinion of the institutional review board of the local coordinating centre was necessary to obtain the opinions from the institutional review boards of the other hospitals. The information requested by the different committees and the time to obtain the approvals varied, even within the same country. This degree of complexity and disharmony, and resulting cost, was observed in a simple retrospective study. Regulators will need to be aware that these time-consuming, expensive and useless complexities must be factored in when estimating the time and cost of a study. Copyright © 2012 John Wiley & Sons, Ltd.

Direct observation of subunit exchange along mature vimentin intermediate filaments.

PubMed

Nöding, Bernd; Herrmann, Harald; Köster, Sarah

2014-12-16

Actin filaments, microtubules, and intermediate filaments (IFs) are central elements of the metazoan cytoskeleton. At the molecular level, the assembly mechanism for actin filaments and microtubules is fundamentally different from that of IFs. The former two types of filaments assemble from globular proteins. By contrast, IFs assemble from tetrameric complexes of extended, half-staggered, and antiparallel oriented coiled-coils. These tetramers laterally associate into unit-length filaments; subsequent longitudinal annealing of unit-length filaments yields mature IFs. In vitro, IFs form open structures without a fixed number of tetramers per cross-section along the filament. Therefore, a central question for the structural biology of IFs is whether individual subunits can dissociate from assembled filaments and rebind at other sites. Using the fluorescently labeled IF-protein vimentin for assembly, we directly observe and quantitatively determine subunit exchange events between filaments as well as with soluble vimentin pools. Thereby we demonstrate that the cross-sectional polymorphism of donor and acceptor filaments plays an important role. We propose that in segments of donor filaments with more than the standard 32 molecules per cross-section, subunits are not as tightly bound and are predisposed to be released from the filament. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Hands on the sun: Teaching SEC science through hands on inquiery and direct observation

NASA Astrophysics Data System (ADS)

Mayo, L.; Cline, T.; Lewis, E.

2003-04-01

Hands on the Sun is a model partnership between the NASA Sun Earth Connection Education Forum (SECEF), Coronado Instruments, Space Science Institute, NOAO/Kitt Peak, Flandrau Planetarium, Astronomical League, and professional astronomers. This joint venture uses experiential learning, provocative talks, and direct observation in both formal and informal education venues to teach participants (K-12 educators, amateur astronomers, and the general public) about the sun, its impact on the Earth, and the importance of understanding the sun-Earth system. The program consists of three days of workshops and activities including tours and observing sessions on Kitt Peak including the National Solar Observatory, planetarium shows, exhibits on space weather, and professional development workshops targeted primarily at Hispanic public school science teachers which are intended to provide hands on activities demonstrating solar and SEC science that can be integrated into the classroom science curriculum. This talk will describe the many facets of this program and discuss our plans for future events.

Bi-directional streaming of halo electrons in interplanetary plasma clouds observed between 0.3 and 1 AU

NASA Technical Reports Server (NTRS)

Ivory, K.; Schwenn, R.

1995-01-01

The solar wind data obtained from the two Helios solar probes in the years 1974 to 1986 were systematically searched for the occurrence of bi-directional electron events. Most often these events are found in conjunction with shock associated magnetic clouds. The implications of these observations for the topology of interplanetary plasma clouds are discussed.

Photoacoustics of single laser-trapped nanodroplets for the direct observation of nanofocusing in aerosol photokinetics

NASA Astrophysics Data System (ADS)

Cremer, Johannes W.; Thaler, Klemens M.; Haisch, Christoph; Signorell, Ruth

2016-03-01

Photochemistry taking place in atmospheric aerosol droplets has a significant impact on the Earth's climate. Nanofocusing of electromagnetic radiation inside aerosols plays a crucial role in their absorption behaviour, since the radiation flux inside the droplet strongly affects the activation rate of photochemically active species. However, size-dependent nanofocusing effects in the photokinetics of small aerosols have escaped direct observation due to the inability to measure absorption signatures from single droplets. Here we show that photoacoustic measurements on optically trapped single nanodroplets provide a direct, broadly applicable method to measure absorption with attolitre sensitivity. We demonstrate for a model aerosol that the photolysis is accelerated by an order of magnitude in the sub-micron to micron size range, compared with larger droplets. The versatility of our technique promises broad applicability to absorption studies of aerosol particles, such as atmospheric aerosols where quantitative photokinetic data are critical for climate predictions.

Photoacoustics of single laser-trapped nanodroplets for the direct observation of nanofocusing in aerosol photokinetics

PubMed Central

Cremer, Johannes W.; Thaler, Klemens M.; Haisch, Christoph; Signorell, Ruth

2016-01-01

Photochemistry taking place in atmospheric aerosol droplets has a significant impact on the Earth's climate. Nanofocusing of electromagnetic radiation inside aerosols plays a crucial role in their absorption behaviour, since the radiation flux inside the droplet strongly affects the activation rate of photochemically active species. However, size-dependent nanofocusing effects in the photokinetics of small aerosols have escaped direct observation due to the inability to measure absorption signatures from single droplets. Here we show that photoacoustic measurements on optically trapped single nanodroplets provide a direct, broadly applicable method to measure absorption with attolitre sensitivity. We demonstrate for a model aerosol that the photolysis is accelerated by an order of magnitude in the sub-micron to micron size range, compared with larger droplets. The versatility of our technique promises broad applicability to absorption studies of aerosol particles, such as atmospheric aerosols where quantitative photokinetic data are critical for climate predictions. PMID:26979973

Direct Observations of Graphene Dispersed in Solution by Twilight Fluorescence Microscopy.

PubMed

Matsuno, Yutaka; Sato, Yu-Uya; Sato, Hikaru; Sano, Masahito

2017-06-01

Graphene and graphene oxide (GO) in solution were directly observed by a newly developed twilight fluorescence (TwiF) microscopy. A nanocarbon dispersion was mixed with a highly concentrated fluorescent dye solution and placed in a cell with a viewing glass at the bottom. TwiF microscopy images the nanocarbon material floating within a few hundred μm of the glass surface by utilizing two optical processes to provide a faintly illuminating backlight and visualizes GO as either a dark image by absorption and energy transfer processes or a bright image by alternation of fluorophore chemistry and autofluorescence. Individual graphene and GO sheets ranging from submicron to submillimeter widths were clearly imaged at different wavelengths, which were selectable based on the dye used. Graphene could be differentiated from GO coexisting in the same solution. Partial transparency revealed layering and network structures. Motions in tumbling flow were recognized in real time. An effect of changing the solvent and the process of adhesion on the glass surface were followed in situ.

Numerical Analysis of the Effect of Active Wind Speed and Direction on Circulation of Sea of Azov Water with and without Allowance for the Water Exchange through the Kerch Strait

NASA Astrophysics Data System (ADS)

Cherkesov, L. V.; Shul'ga, T. Ya.

2018-01-01

The effect of seawater movement through the Kerch Strait for extreme deviations in the level and speed of currents in the Sea of Azov caused by the action of climate wind fields has been studied using the Princeton ocean model (POM), a general three-dimensional nonlinear model of ocean circulation. Formation of the water flow through the strait is caused by the long-term action of the same type of atmospheric processes. The features of the water dynamics under conditions of changing intensity and active wind direction have been studied. Numerical experiments were carried out for two versions of model Sea of Azov basins: closed (without the Kerch Strait) and with a fluid boundary located in the Black Sea. The simulation results have shown that allowance for the strait leads to a significant change in the velocities of steady currents and level deviations at wind speeds greater than 5 m/s. The most significant effect on the parameters of steady-state movements is exerted by the speed of the wind that generates them; allowance for water exchange through the strait is less important. Analysis of the directions of atmospheric circulation has revealed that the response generated by the movement of water through the strait is most pronounced when a southeast wind is acting.

Global Night-Time Lights for Observing Human Activity

NASA Technical Reports Server (NTRS)

Hipskind, Stephen R.; Elvidge, Chris; Gurney, K.; Imhoff, Mark; Bounoua, Lahouari; Sheffner, Edwin; Nemani, Ramakrishna R.; Pettit, Donald R.; Fischer, Marc

2011-01-01

We present a concept for a small satellite mission to make systematic, global observations of night-time lights with spatial resolution suitable for discerning the extent, type and density of human settlements. The observations will also allow better understanding of fine scale fossil fuel CO2 emission distribution. The NASA Earth Science Decadal Survey recommends more focus on direct observations of human influence on the Earth system. The most dramatic and compelling observations of human presence on the Earth are the night light observations taken by the Defence Meteorological System Program (DMSP) Operational Linescan System (OLS). Beyond delineating the footprint of human presence, night light data, when assembled and evaluated with complementary data sets, can determine the fine scale spatial distribution of global fossil fuel CO2 emissions. Understanding fossil fuel carbon emissions is critical to understanding the entire carbon cycle, and especially the carbon exchange between terrestrial and oceanic systems.

The total carbon column observing network.

PubMed

Wunch, Debra; Toon, Geoffrey C; Blavier, Jean-François L; Washenfelder, Rebecca A; Notholt, Justus; Connor, Brian J; Griffith, David W T; Sherlock, Vanessa; Wennberg, Paul O

2011-05-28

A global network of ground-based Fourier transform spectrometers has been founded to remotely measure column abundances of CO(2), CO, CH(4), N(2)O and other molecules that absorb in the near-infrared. These measurements are directly comparable with the near-infrared total column measurements from space-based instruments. With stringent requirements on the instrumentation, acquisition procedures, data processing and calibration, the Total Carbon Column Observing Network (TCCON) achieves an accuracy and precision in total column measurements that is unprecedented for remote-sensing observations (better than 0.25% for CO(2)). This has enabled carbon-cycle science investigations using the TCCON dataset, and allows the TCCON to provide a link between satellite measurements and the extensive ground-based in situ network. © 2011 The Royal Society

Multi-Wavelength Spectroscopic Observations of a White Light Flare Produced Directly by Non-thermal Electrons

NASA Astrophysics Data System (ADS)

Lee, Kyoung-Sun; Imada, Shinsuke; Watanabe, Kyoko; Bamba, Yumi; Brooks, David

2017-08-01

An X1.6 flare on 2014 October 22 was observed by multiple spectrometers in UV, EUV and X-ray (Hinode/EIS, IRIS, and RHESSI), and multi-wavelength imaging observations (SDO/AIA and HMI). We analyze a bright kernel that produces a white light (WL) flare with continuum enhancement and a hard X-ray (HXR) peak. Taking advantage of the spectroscopic observations of IRIS and Hinode/EIS, we measure the temporal variation of the plasma properties in the bright kernel in the chromosphere and corona. We find that explosive evaporation was observed when the WL emission occurred. The temporal correlation of the WL emission, HXR peak, and evaporation flows indicates that the WL emission was produced by accelerated electrons. We calculated the energy flux deposited by non-thermal electrons (observed by RHESSI) and compared it to the dissipated energy estimated from a chromospheric line (Mg II triplet) observed by IRIS. The deposited energy flux from the non-thermal electrons is about (3-7.7)x1010 erg cm-2 s-1 for a given low-energy cutoff of 30-40 keV, assuming the thick-target model. The energy flux estimated from the changes in temperature in the chromosphere measured using the Mg II subordinate line is about (4.6-6.7)×109 erg cm-2 s-1: ˜6%-22% of the deposited energy. This comparison of estimated energy fluxes implies that the continuum enhancement was directly produced by the non-thermal electrons.

HIGH-PRESSURE PHYSICS. Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium.

PubMed

Knudson, M D; Desjarlais, M P; Becker, A; Lemke, R W; Cochrane, K R; Savage, M E; Bliss, D E; Mattsson, T R; Redmer, R

2015-06-26

Eighty years ago, it was proposed that solid hydrogen would become metallic at sufficiently high density. Despite numerous investigations, this transition has not yet been experimentally observed. More recently, there has been much interest in the analog of this predicted metallic transition in the dense liquid, due to its relevance to planetary science. Here, we show direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium. Experimental determination of the location of this transition provides a much-needed benchmark for theory and may constrain the region of hydrogen-helium immiscibility and the boundary-layer pressure in standard models of the internal structure of gas-giant planets. Copyright © 2015, American Association for the Advancement of Science.

Stress Drop and Directivity Patterns Observed in Small-Magnitude (

NASA Astrophysics Data System (ADS)

Ruhl, C. J.; Hatch, R. L.; Abercrombie, R. E.; Smith, K.

2017-12-01

Recent improvements in seismic instrumentation and network coverage in the Reno, NV area have provided high-quality records of abundant microseismicity, including several swarms and clusters. Here, we discuss stress drop and directivity patterns of small-magnitude seismicity in the 2008 Mw4.9 Mogul earthquake swarm in Reno, NV and in the nearby region of an ML3.2 sequence near Virginia City, NV. In both sequences, double-difference relocated earthquakes cluster on multiple distinct structures consistent with focal mechanism and moment tensor fault plane solutions. Both sequences also show migration potentially related to fluid flow. We estimate corner frequency and stress drop using EGF-derived spectral ratios, convolving earthquake pairs (target*EGF) such that we preserve phase and recover source-time functions (STF) on a station-by-station basis. We then stack individual STFs per station for all EGF-target pairs per target earthquake, increasing the signal-to-noise of our results. By applying an azimuthal- and incidence-angle-dependent stretching factor to STFs in the time domain, we are able to invert for rupture directivity and velocity assuming both unilateral and bilateral rupture. Earthquakes in both sequences, some as low as ML2.1, show strong unilateral directivity consistent with independent fault plane solutions. We investigate and compare the relationship between rupture and migration directions on subfaults within each sequence. Average stress drops for both sequences are 4 MPa, but there is large variation in individual estimates for both sequences. Although this variation is not explained simply by any one parameter (e.g., depth), spatiotemporal variation in the Mogul swarm is distinct: coherent clusters of high and low stress drop earthquakes along the mainshock fault plane are seen, and high-stress-drop foreshocks correlate with an area of reduced aftershock productivity. These observations are best explained by a difference in rheology along the

Copernicus observations of neutral hydrogen and deuterium in the direction of HR 1099

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Weiler, E. J.

1979-01-01

High-resolution Copernicus U1 scans were obtained of the bright RS CVn binary HR 1099 (d = 33 pc, galactic longitude = 185 deg, galactic latitude = -41 deg) in October 1977. Strong emission at L-alpha was detected. The interstellar L-alpha absorption features of H I and D I were also observed. Analyses of these interstellar lines are reported in this paper. The average density of neutral H in the direction of this system is found to be 0.006-0.012 per cu cm, which, because the local density is higher, requires a marked inhomogeneity along this line of sight. This result, when combined with other recent studies of the local interstellar medium, suggests the sun is located within a moderate-density H I region.

Future direction of direct writing

NASA Astrophysics Data System (ADS)

Kim, Nam-Soo; Han, Kenneth N.

2010-11-01

Direct write technology using special inks consisting of finely dispersed metal nanoparticles in liquid is receiving an undivided attention in recent years for its wide range of applicability in modern electronic industry. The application of this technology covers radio frequency identification-tag (RFID-tag), flexible-electronics, organic light emitting diodes (OLED) display, e-paper, antenna, bumpers used in flip-chip, underfilling, frit, miniresistance applications and biological uses, artificial dental applications and many more. In this paper, the authors have reviewed various direct write technologies on the market and discussed their advantages and shortfalls. Emphasis has given on microdispensing deposition write (MDDW), maskless mesoscale materials deposition (M3D), and ink-jet technologies. All of these technologies allow printing various patterns without employing a mask or a resist with an enhanced speed with the aid of computer. MDDW and M3D are capable of drawing patterns in three-dimension and MDDW, in particular, is capable of writing nanoinks with high viscosity. However, it is still far away for direct write to be fully implemented in the commercial arena. One of the hurdles to overcome is in manufacturing conductive inks which are chemically and physically stable, capable of drawing patterns with acceptable conductivity, and also capable of drawing patterns with acceptable adhesiveness with the substrates. The authors have briefly discussed problems involved in manufacturing nanometal inks to be used in various writing devices. There are numerous factors to be considered in manufacturing such inks. They are reducing agents, concentrations, oxidation, compact ability allowing good conductivity, and stability in suspension.

Cognitive Correlates of Functional Abilities in Individuals with Mild Cognitive Impairment: Comparison of Questionnaire, Direct Observation and Performance-based Measures

PubMed Central

Schmitter-Edgecombe, Maureen; Parsey, Carolyn M.

2014-01-01

The relationship between and the cognitive correlates of several proxy measures of functional status were studied in a population with mild cognitive impairment (MCI). Participants were 51 individuals diagnosed with MCI and 51 cognitively healthy older adults (OA). Participants completed performance-based functional status tests, standardized neuropsychological tests, and performed eight activities of daily living (e.g., watered plants, filled medication dispenser) while under direct observation in a campus apartment. An informant interview about everyday functioning was also conducted. Compared to the OA control group, the MCI group performed more poorly on all proxy measures of everyday functioning. The informant-report of instrumental activities of daily living (IADL) did not correlate with the two performance-based measures; however, both the informant-report IADL and the performance-based everyday problem-solving test correlated with the direct observation measure. After controlling for age and education, cognitive predictors did not explain a significant amount of variance in the performance-based measures; however, performance on a delayed memory task was a unique predictor for the informant-report IADL, and processing speed predicted unique variance for the direct observation score. These findings indicate that differing methods for evaluating functional status are not assessing completely overlapping aspects of everyday functioning in the MCI population. PMID:24766574

Cognitive correlates of functional abilities in individuals with mild cognitive impairment: comparison of questionnaire, direct observation, and performance-based measures.

PubMed

Schmitter-Edgecombe, Maureen; Parsey, Carolyn M

2014-01-01

The relationship between, and the cognitive correlates of, several proxy measures of functional status were studied in a population with mild cognitive impairment (MCI). Participants were 51 individuals diagnosed with MCI and 51 cognitively healthy older adults (OA). Participants completed performance-based functional status tests and standardized neuropsychological tests, and performed eight activities of daily living (e.g., watered plants, filled medication dispenser) while under direct observation in a campus apartment. An informant interview about everyday functioning was also conducted. Compared to the OA control group, the MCI group performed more poorly on all proxy measures of everyday functioning. The informant report of instrumental activities of daily living (IADL) did not correlate with the two performance-based measures; however, both the informant-report IADL and the performance-based everyday problem-solving test correlated with the direct observation measure. After controlling for age and education, cognitive predictors did not explain a significant amount of variance in the performance-based measures; however, performance on a delayed memory task was a unique predictor for the informant-report IADL, and processing speed predicted unique variance for the direct observation score. These findings indicate that differing methods for evaluating functional status are not assessing completely overlapping aspects of everyday functioning in the MCI population.

[Nursing performance in the policy transfer of directly observed treatment of tuberculosis].

PubMed

Souza, Káren Mendes Jorge de; Sá, Lenilde Duarte de; Silva, Laís Mara Caetano da; Palha, Pedro Fredemir

2014-10-01

Analyzing the policy transfer of directly observed treatment of tuberculosis from the perspective of nursing. This is a descriptive study with qualitative approach, which had 10 nurses of the Family Health Strategy in São Paulo as subjects. The interviews were carried out between May and June 2013, and were adopted the technique of thematic content analysis and the referential of policy transfer. On the signification of this treatment, are related the senses of disciplinary monitoring, the bond and approximation to the context of patients' lives. Operationally, nurses, community health agents and nursing technicians stand out as agents of implementation of this policy, developing multiple actions of user embracement. The nurse is evidenced as an educator in health, leader in the family health team, and capable of creating emotional bond with users. It was found that the innovations proposed in the treatment are incipient in the daily work of nurses.

Jupiter Trojan's Shallow Subsurface: Direct Observation By Radar Sounding

NASA Astrophysics Data System (ADS)

Herique, A.; Plettemeier, D.; Beck, P.; Michel, P.; Kumamoto, A.; Kofman, W. W.

2017-12-01

Most of the Jupiter's Trojan are classified as spectral type P or D from visible and near-IR observations. Still, major question remain regarding theire origin and geological evolution: What ices are present in their interior, and in what amount? What is the abundance and the nature of the organic fraction? Did they experience some level of differentiation powered by 26Al? Answering theses question is the goal of the Solar-Power Sail JAXA mission [1, 2]. This mission plans to study the surface by remote sensing in the optical in IR domain. This probe will carry a large-sized lander with a drill to sample the constitutive material at meter depth in order to complement physical and chemical properties measured by on-board instruments. The sample return is an option under study.Radar sounding of the shallow subsurface would be envisaged in complement to this payload. Sounding radar could provide the structure of the first tens of meters of the Trojan surface. It will allow identifying layering, ice lens, and embedded block. It also will enable to reconnect the surface with the deep interior in order to identify exogenous / pristine material. For the surface package, the drilling and the sample return, radar sounding is a unique opportunity to support the selection of the landing site and to provide the greater geological context of the samples that will be returned to Earth.In this paper, we will detail the objective of this instrument and then we will outline the proposed instrument, which is inheriting from the radar developed for the AIDA/AIM mission.[1] Mori, O. et al., Science experiments on a Jupiter Trojan Asteroid in the solar powerd sail mission. LPSC 2016 - 1822.[2] Okada, T. et al., Science and Exploration of a Jupiter Trojan Asteroid in the solar-power sail mission. LPSC 2017 - 1828.

Tagging motor memories with transcranial direct current stimulation allows later artificially-controlled retrieval

PubMed Central

Nozaki, Daichi; Yokoi, Atsushi; Kimura, Takahiro; Hirashima, Masaya; Orban de Xivry, Jean-Jacques

2016-01-01

We demonstrate that human motor memories can be artificially tagged and later retrieved by noninvasive transcranial direct current stimulation (tDCS). Participants learned to adapt reaching movements to two conflicting dynamical environments that were each associated with a different tDCS polarity (anodal or cathodal tDCS) on the sensorimotor cortex. That is, we sought to determine whether divergent background activity levels within the sensorimotor cortex (anodal: higher activity; cathodal: lower activity) give rise to distinct motor memories. After a training session, application of each tDCS polarity automatically resulted in the retrieval of the motor memory corresponding to that polarity. These results reveal that artificial modulation of neural activity in the sensorimotor cortex through tDCS can act as a context for the formation and recollection of motor memories. DOI: http://dx.doi.org/10.7554/eLife.15378.001 PMID:27472899

Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water

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

University of California, Berkeley; Lawrence Berkeley National Laboratory; Raymond, Kenneth

2007-10-22

Understanding the solution behavior of supramolecular assemblies is essential for a full understanding of the formation and chemistry of synthetic host-guest systems. While the interaction between host and guest molecules is generally the focus of mechanistic studies of host-guest complexes, the interaction of the host-guest complex with other species in solution remains largely unknown, although in principle accessible by diffusion studies. Several NMR techniques are available to monitor diffusion and have recently been reviewed. Pulsed gradient spin-echo (PGSE) NMR methods have attracted increasing interest, since they allow diffusion coefficients to be measured with high accuracy; they have been successfully usedmore » with observation of {sup 7}Li and {sup 31}P nuclei as well as with {sup 1}H NMR. We report here the direct measurement of diffusion coefficients to observe ion-association interactions by counter cations with a highly-charged supramolecular assembly. Raymond and coworkers have described the design and chemistry of a class of metal-ligand supramolecular assemblies over the past decade. The [Ga{sub 4}L{sub 6}]{sup 12-} (L = 1,5-bis(2,3-dihydroxybenzamido)naphthalene) (1) (Figure 1) assembly has garnered the most attention, with the exploration of the dynamics and mechanism of guest exchange as well as the ability of 1 to achieve either stoichiometric or catalytic reactions inside its interior cavity. Recent studies have revealed the importance of counter cations in solution on the chemistry of 1. During the mechanistic study of the C-H bond activation of aldehydes by [Cp*Ir(PMe{sub 3})(olefin){sup +} {contained_in} 1]{sup 11-} a stepwise guest dissociation mechanism with an ion-paired intermediate was proposed. Similarly, in the mechanism for the hydrolysis of iminium cations generated from the 3-aza Cope rearrangement of enammonium cations in 1, the presence of an exterior ion association was part of the kinetic model. To further substantiate the

Direct observation of a surface resonance state and surface band inversion control in black phosphorus

NASA Astrophysics Data System (ADS)

Ehlen, N.; Sanna, A.; Senkovskiy, B. V.; Petaccia, L.; Fedorov, A. V.; Profeta, G.; Grüneis, A.

2018-01-01

We report a Cs-doping-induced band inversion and the direct observation of a surface resonance state with an elliptical Fermi surface in black phosphorus (BP) using angle-resolved photoemission spectroscopy. By selectively inducing a higher electron concentration (1.7 ×1014cm-2 ) in the topmost layer, the changes in the Coulomb potential are sufficiently large to cause surface band inversion between the parabolic valence band of BP and a parabolic surface state around the Γ point of the BP Brillouin zone. Tight-binding calculations reveal that band gap openings at the crossing points in the two high-symmetry directions of the Brillouin zone require out-of-plane hopping and breaking of the glide mirror symmetry. Ab initio calculations are in very good agreement with the experiment if a stacking fault on the BP surface is taken into account. The demonstrated level of control over the band structure suggests the potential application of few-layer phosphorene in topological field-effect transistors.

Implementation of a direct-imaging and FX correlator for the BEST-2 array

NASA Astrophysics Data System (ADS)

Foster, G.; Hickish, J.; Magro, A.; Price, D.; Zarb Adami, K.

2014-04-01

A new digital backend has been developed for the Basic Element for SKA Training II (BEST-2) array at Radiotelescopi di Medicina, INAF-IRA, Italy, which allows concurrent operation of an FX correlator, and a direct-imaging correlator and beamformer. This backend serves as a platform for testing some of the spatial Fourier transform concepts which have been proposed for use in computing correlations on regularly gridded arrays. While spatial Fourier transform-based beamformers have been implemented previously, this is, to our knowledge, the first time a direct-imaging correlator has been deployed on a radio astronomy array. Concurrent observations with the FX and direct-imaging correlator allow for direct comparison between the two architectures. Additionally, we show the potential of the direct-imaging correlator for time-domain astronomy, by passing a subset of beams though a pulsar and transient detection pipeline. These results provide a timely verification for spatial Fourier transform-based instruments that are currently in commissioning. These instruments aim to detect highly redshifted hydrogen from the epoch of reionization and/or to perform wide-field surveys for time-domain studies of the radio sky. We experimentally show the direct-imaging correlator architecture to be a viable solution for correlation and beamforming.

Stimulus learning and response learning by observation in the European starling, in a two-object/two-action test.

PubMed

Campbell; Heyes; Goldsmith

1999-07-01

Juvenile European starlings, Sturnus vulgaris, were allowed to observe a conspecific demonstrator using its beak to remove one of two distinctively coloured objects (i.e. a red or a black plug) from a hole in the lid of a plastic box. Both plugs could be removed by either pulling up on a loop of string inserted through the centre of the plug, or pushing down on the plug. When subsequently allowed access to the plugs, and rewarded with food for all removal responses, regardless of the object to which they were made and their direction, observer birds removed the same plug in the same direction as their demonstrator. These results suggest that the two-object/two-action paradigm is a valuable procedure for testing for the simultaneous effects of learning about a stimulus and a response, an object and an action, through conspecific observation. Copyright 1999 The Association for the Study of Animal Behaviour.

Direct observation of ballistic Andreev reflection

NASA Astrophysics Data System (ADS)

Klapwijk, T. M.; Ryabchun, S. A.

2014-12-01

An overview is presented of experiments on ballistic electrical transport in inhomogeneous superconducting systems which are controlled by the process of Andreev reflection. The initial experiments based on the coexistence of a normal phase and a superconducting phase in the intermediate state led to the concept itself. It was followed by a focus on geometrically inhomogeneous systems like point contacts, which provided a very clear manifestation of the energy and direction dependence of the Andreev reflection process. The point contacts have recently evolved towards the atomic scale owing to the use of mechanical break-junctions, revealing a very detailed dependence of Andreev reflection on the macroscopic phase of the superconducting state. In present-day research, the superconducting in homogeneity is constructed by clean room technology and combines superconducting materials, for example, with low-dimensional materials and topological insulators. Alternatively, the superconductor is combined with nano-objects, such as graphene, carbon nanotubes, or semiconducting nanowires. Each of these "inhomogeneous systems" provides a very interesting range of properties, all rooted in some manifestation of Andreev reflection.

Direct observation of ballistic Andreev reflection

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

Klapwijk, T. M., E-mail: t.m.klapwijk@tudelft.nl; Ryabchun, S. A.

2014-12-15

An overview is presented of experiments on ballistic electrical transport in inhomogeneous superconducting systems which are controlled by the process of Andreev reflection. The initial experiments based on the coexistence of a normal phase and a superconducting phase in the intermediate state led to the concept itself. It was followed by a focus on geometrically inhomogeneous systems like point contacts, which provided a very clear manifestation of the energy and direction dependence of the Andreev reflection process. The point contacts have recently evolved towards the atomic scale owing to the use of mechanical break-junctions, revealing a very detailed dependence ofmore » Andreev reflection on the macroscopic phase of the superconducting state. In present-day research, the superconducting in homogeneity is constructed by clean room technology and combines superconducting materials, for example, with low-dimensional materials and topological insulators. Alternatively, the superconductor is combined with nano-objects, such as graphene, carbon nanotubes, or semiconducting nanowires. Each of these “inhomogeneous systems” provides a very interesting range of properties, all rooted in some manifestation of Andreev reflection.« less

An Approach to Assess Observation Impact Based on Observation-Minus-Forecast Residuals

NASA Technical Reports Server (NTRS)

Todling, Ricardo

2009-01-01

Langland and Baker (2004) introduced an approach to assess the impact of observations on the forecasts. In that, a state-space aspect of the forecast is defined and a procedure is derived that relates changes in the aspect with changes in the initial conditions associated with the assimilation of observations) ultimately providing information about the impact of individual observations on the forecast. Some features of the approach are to be noted. The typical choice of forecast aspect employed in related works is rather arbitrary and leads to an incomplete assessment of the observing system. Furthermore, the state-space forecast aspect requires availability of a verification state that should ideally be uncorrelated with the forecast but in practice is not. Lastly, the approach involves the adjoint operator of the entire data assimilation system and as such it is constrained by the validity of this operator. In this presentation, an observation-space metric is used that, for a relatively time-homogeneous observing system, allows inferring observation impact on the forecast without some of the limitations above. Specifically, using observation-minus-forecast residuals leads to an approach with the following features: (i) it suggests a rather natural choice of forecast aspect, directly linked to the analysis system and providing full assessment of the observations; (ii) it naturally avoids introducing undesirable correlations in the forecast aspect by verifying against the observations; and (iii) it does not involve linearization and use of adjoints; therefore being applicable to any length of forecast. The state and observation-space approaches might be complementary to some degree, and involve different limitations and complexities. Illustrations are given using the NASA GEOS-5 data.

The 'semitorrid' gas observed in the direction of Gamma-2 Velorum and the Gum nebula

NASA Technical Reports Server (NTRS)

Bruhweiler, F. C.; Kondo, J.; Mccluskey, G. E., Jr.

1979-01-01

On the basis of recent IUE observations in the far-ultraviolet, the authors report the detection of a 'semitorrid' region of the interstellar medium in the direction of Gamma-2 Velorum and the Gum nebula. The characteristic temperature of this gas is in the 40,000 K range, between the warm (around 1000 K) and hot (roughly 100,000-1,000,000 K) regions reported by various investigators. This temperature is compatible with the theoretical temperature ascribed to the 'fossil Stromgren sphere' by Brandt et al. and Alexander et al.

Soil Moisture Controls on Rainfall and Temperature Variability: A Modeler Searches Through Observational Data

NASA Technical Reports Server (NTRS)

Koster, Randal

2010-01-01

The degree to which atmospheric processes respond to variations in soil moisture - a potentially important but largely untapped element of subseasonal to seasonal prediction - can be determined easily and directly for an atmospheric model but cannot be determined directly for nature through an analysis of observations. In atmospheric models) directions of causality can be artificially manipulated; we can avoid difficulties associated with the fact that atmospheric variations have a much larger impact on land state variations than vice-versa. In nature) on the other hand) the dominant direction of causality (the atmosphere forcing the ground) cannot be artificially "turned off") and the statistics associated with this dominant direction overwhelm those of the feedback signal. Observational data) however) do allow a number of indirect measures of landatmosphere feedback. This seminar reports on a series of joint analyses of observational and model data designed to illuminate the degree of land-atmosphere feedback present in the real world. The indirect measures do in fact suggest that feedback in nature, though small) is significant - enough to warrant the development of realistic land initialization strategies for subseasonal and seasonal forecasts.

Ion kinetic scale in the solar wind observed.

PubMed

Śafránková, Jana; Němeček, Zdeněk; Přech, Lubomír; Zastenker, Georgy N

2013-01-11

This Letter shows the first results from the solar wind monitor onboard the Spektr-R spacecraft which measures plasma moments with a time resolution of 31 ms. This high-time resolution allows us to make direct observations of solar wind turbulence below ion kinetic length scales. We present examples of the frequency spectra of the density, velocity, and thermal velocity. Our study reveals that although these parameters exhibit the same behavior at the magnetohydrodynamic scale, their spectra are remarkably different at the kinetic scale.

TDM Status Report: Transportation Allowances

DOT National Transportation Integrated Search

1992-08-01

The status report discusses the following travel allowance programs that provide subsidies to employees in one form or another: transit fare allowances or subsidies; vanpool fare allowances; parking allowances or free parking; and general travel allo...

Directional topographic site response at Tarzana observed in aftershocks of the 1994 Northridge, California, earthquake: Implications for mainshock motions

USGS Publications Warehouse

Spudich, P.; Hellweg, M.; Lee, W.H.K.

1996-01-01

The Northridge earthquake caused 1.78 g acceleration in the east-west direction at a site in Tarzana, California, located about 6 km south of the mainshock epicenter. The accelerograph was located atop a hill about 15-m high, 500-m long, and 130-m wide, striking about N78??E. During the aftershock sequence, a temporary array of 21 three-component geophones was deployed in six radial lines centered on the accelerograph, with an average sensor spacing of 35 m. Station COO was located about 2 m from the accelerograph. We inverted aftershock spectra to obtain average relative site response at each station as a function of direction of ground motion. We identified a 3.2-Hz resonance that is a transverse oscillation of the hill (a directional topographic effect). The top/base amplification ratio at 3.2 Hz is about 4.5 for horizontal ground motions oriented approximately perpendicular to the long axis of the hill and about 2 for motions parallel to the hill. This resonance is seen most strongly within 50 m of COO. Other resonant frequencies were also observed. A strong lateral variation in attenuation, probably associated with a fault, caused substantially lower motion at frequencies above 6 Hz at the east end of the hill. There may be some additional scattered waves associated with the fault zone and seen at both the base and top of the hill, causing particle motions (not spectral ratios) at the top of the hill to be rotated about 20?? away from the direction transverse to the hill. The resonant frequency, but not the amplitude, of our observed topographic resonance agrees well with theory, even for such a low hill. Comparisons of our observations with theoretical results indicate that the 3D shape of the hill and its internal structure are important factors affecting its response. The strong transverse resonance of the hill does not account for the large east-west mainshock motions. Assuming linear soil response, mainshock east-west motions at the Tarzana accelerograph

Direct Observation of 2D Electrostatics and Ohmic Contacts in Template-Grown Graphene/WS2 Heterostructures.

PubMed

Zheng, Changxi; Zhang, Qianhui; Weber, Bent; Ilatikhameneh, Hesameddin; Chen, Fan; Sahasrabudhe, Harshad; Rahman, Rajib; Li, Shiqiang; Chen, Zhen; Hellerstedt, Jack; Zhang, Yupeng; Duan, Wen Hui; Bao, Qiaoliang; Fuhrer, Michael S

2017-03-28

Large-area two-dimensional (2D) heterojunctions are promising building blocks of 2D circuits. Understanding their intriguing electrostatics is pivotal but largely hindered by the lack of direct observations. Here graphene-WS 2 heterojunctions are prepared over large areas using a seedless ambient-pressure chemical vapor deposition technique. Kelvin probe force microscopy, photoluminescence spectroscopy, and scanning tunneling microscopy characterize the doping in graphene-WS 2 heterojunctions as-grown on sapphire and transferred to SiO 2 with and without thermal annealing. Both p-n and n-n junctions are observed, and a flat-band condition (zero Schottky barrier height) is found for lightly n-doped WS 2 , promising low-resistance ohmic contacts. This indicates a more favorable band alignment for graphene-WS 2 than has been predicted, likely explaining the low barriers observed in transport experiments on similar heterojunctions. Electrostatic modeling demonstrates that the large depletion width of the graphene-WS 2 junction reflects the electrostatics of the one-dimensional junction between two-dimensional materials.

Cost and cost-effectiveness of community based and health facility based directly observed treatment of tuberculosis in Dar es Salaam, Tanzania

PubMed Central

Wandwalo, Eliud; Robberstad, Bjarne; Morkve, Odd

2005-01-01

Background Identifying new approaches to tuberculosis treatment that are effective and put less demand to meagre health resources is important. One such approach is community based direct observed treatment (DOT). The purpose of the study was to determine the cost and cost effectiveness of health facility and community based directly observed treatment of tuberculosis in an urban setting in Tanzania. Methods Two alternative strategies were compared: health facility based directly observed treatment by health personnel and community based directly observed treatment by treatment supervisors. Costs were analysed from the perspective of health services, patients and community in the year 2002 in US $ using standard methods. Treatment outcomes were obtained from a randomised-controlled trial which was conducted alongside the cost study. Smear positive, smear negative and extra-pulmonary TB patients were included. Cost-effectiveness was calculated as the cost per patient successfully treated. Results The total cost of treating a patient with conventional health facility based DOT and community based DOT were $ 145 and $ 94 respectively. Community based DOT reduced cost by 35%. Cost fell by 27% for health services and 72% for patients. When smear positive and smear negative patients were considered separately, community DOT was associated with 45% and 19% reduction of the costs respectively. Patients used about $ 43 to follow their medication to health facility which is equivalent to their monthly income. Indirect costs were as important as direct costs, contributing to about 49% of the total patient's cost. The main reason for reduced cost was fewer number of visits to the TB clinic. Community based DOT was more cost-effective at $ 128 per patient successfully treated compared to $ 203 for a patient successfully treated with health facility based DOT. Conclusion Community based DOT presents an economically attractive option to complement health facility based DOT. This

Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries

DOE PAGES

Wang, Qiang; Zheng, Jianming; Walter, Eric; ...

2015-01-09

Lithium sulfur (Li-S) battery has been regaining tremendous interest in recent years because of its attractive attributes such as high gravimetric energy, low cost and environmental benignity. However, it is still not conclusively known how polysulfide ring/chain participates in the whole cycling and whether the discharge and charge processes follow the same pathway. Herein, we demonstrate the direct observation of sulfur radicals by using in situ electron paramagnetic resonance (EPR) technique. Based on the concentration changes of sulfur radicals at different potentials and the electrochemical characteristics of the cell, it is revealed that the chemical and electrochemical reactions in Li-Smore » cell are driving each other to proceed through sulfur radicals, leading to two completely different reaction pathways during discharge and charge. The proposed radical mechanism may provide new perspectives to investigate the interactions between sulfur species and the electrolyte, inspiring novel strategies to develop Li-S battery technology.« less

Satellite observations of type III solar radio bursts at low frequencies

NASA Technical Reports Server (NTRS)

Fainberg, J.; Stone, R. G.

1974-01-01

Type III solar radio bursts have been observed from 10 MHz to 10 kHz by satellite experiments above the terrestrial plasmasphere. Solar radio emission in this frequency range results from excitation of the interplanetary plasma by energetic particles propagating outward along open field lines over distances from 5 earth radii to at least 1 AU from the sun. This review summarizes the morphology, characteristics, and analysis of individual as well as storms of bursts. Substantial evidence is available to show that the radio emission is observed at the second harmonic instead of the fundamental of the plasma frequency. This brings the density scale derived by radio observations into better agreement with direct solar wind density measurements at 1 AU and relaxes the requirement for type III propagation along large density-enhanced regions. This density scale with the measured direction of arrival of the radio burst allows the trajectory of the exciter path to be determined from 10 earth radii to 1 AU.

Magnetospheric Multiscale Observations of Magnetic Reconnection Associated with Kelvin-Helmholtz Waves

NASA Technical Reports Server (NTRS)

Eriksson, S.; Lavraud, B.; Wilder, F. D.; Stawarz, J. E.; Giles, B. L.; Burch, J. L.; Baumjohann, W.; Ergun, R. E.; Lindqvist, P.-A.; Magnes, W.;

Stool frequency recording in severe acute malnutrition ('StoolSAM'); an agreement study comparing maternal recall versus direct observation using diapers.

PubMed

Voskuijl, Wieger; Potani, Isabel; Bandsma, Robert; Baan, Anne; White, Sarah; Bourdon, Celine; Kerac, Marko

2017-06-07

Approximately 50% of the deaths of children under the age of 5 can be attributed to undernutrition, which also encompasses severe acute malnutrition (SAM). Diarrhoea is strongly associated with these deaths and is commonly diagnosed solely based on stool frequency and consistency obtained through maternal recall. This trial aims to determine whether this approach is equivalent to a 'directly observed method' in which a health care worker directly observed stool frequency using diapers in hospitalised children with complicated SAM. This study was conducted at 'Moyo' Nutritional Rehabilitation Unit, Queen Elizabeth Central Hospital, Malawi. Participants were children aged 5-59 months admitted with SAM. We compared 2 days of stool frequency data obtained with next-day maternal-recall versus a 'gold standard' in which a health care worker observed stool frequency every 2 h using diapers. After study completion, guardians were asked their preferred method and their level of education. We found poor agreement between maternal recall and the 'gold standard' of directly observed diapers. The sensitivity to detect diarrhoea based on maternal recall was poor, with only 75 and 56% of diarrhoea cases identified on days 1 and 2, respectively. However, the specificity was higher with more than 80% of children correctly classified as not having diarrhoea. On day 1, the mean stool frequency difference between the two methods was -0.17 (SD; 1.68) with limits of agreement (of stool frequency) of -3.55 and 3.20 and, similarly on day 2, the mean difference was -0.2 (SD; 1.59) with limits of agreement of -3.38 and 2.98. These limits extend beyond the pre-specified 'acceptable' limits of agreement (±1.5 stool per day) and indicate that the 2 methods are non-equivalent. The higher the stool frequency, the more discrepant the two methods were. Most primary care givers strongly preferred using diapers. This study shows lack of agreement between the assessment of stool frequency in SAM

Population genetic structure and direct observations reveal sex-reversed patterns of dispersal in a cooperative bird.

PubMed

Harrison, Xavier A; York, Jennifer E; Young, Andrew J

2014-12-01

Sex-biased dispersal is pervasive and has diverse evolutionary implications, but the fundamental drivers of dispersal sex biases remain unresolved. This is due in part to limited diversity within taxonomic groups in the direction of dispersal sex biases, which leaves hypothesis testing critically dependent upon identifying rare reversals of taxonomic norms. Here, we use a combination of observational and genetic data to demonstrate a rare reversal of the avian sex bias in dispersal in the cooperatively breeding white-browed sparrow weaver (Plocepasser mahali). Direct observations revealed that (i) natal philopatry was rare, with both sexes typically dispersing locally to breed, and (ii), unusually for birds, males bred at significantly greater distances from their natal group than females. Population genetic analyses confirmed these patterns, as (i) corrected Assignment index (AIc), FST tests and isolation-by-distance metrics were all indicative of longer dispersal distances among males than females, and (ii) spatial autocorrelation analysis indicated stronger within-group genetic structure among females than males. Examining the spatial scale of extra-group mating highlighted that the resulting 'sperm dispersal' could have acted in concert with individual dispersal to generate these genetic patterns, but gamete dispersal alone cannot account entirely for the sex differences in genetic structure observed. That leading hypotheses for the evolution of dispersal sex biases cannot readily account for these sex-reversed patterns of dispersal in white-browed sparrow weavers highlights the continued need for attention to alternative explanations for this enigmatic phenomenon. We highlight the potential importance of sex differences in the distances over which dispersal opportunities can be detected. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Surveillance or support: The experience of direct observation during tuberculosis treatment

PubMed Central

Salazar, Irais; Garfein, Richard; Cerecer, Paris; Rodwell, Timothy

2016-01-01

Directly observed therapy (DOT) is a cornerstone of tuberculosis control. DOT has been criticized as paternalistic, but it has also been argued that the interaction with health workers can be a source of support for patients. We explored the experience of patients in antituberculosis treatment, with the aim of understanding the balance between surveillance and support from the recipient’s point of view. We interviewed 27 patients in Tijuana, Mexico, employing narrative analysis to understand how participants made sense of their illness and their experience of DOT. We found a core narrative of biographic disruption and self-reconstruction, in which health care workers helped participants to attribute a less negative meaning to tuberculosis. Interviewees accepted DOT’s as necessary for other people to avoid treatment abandonment, but felt that in their case it was unnecessary. Only a few felt that DOT represented mistrust on the part of the health workers. We conclude that DOT can be a source of support when it is enacted in a patient-centered way. We discuss whether participants’ lack of criticism of DOT is a case of adaptive preference, in the context of a power differential between patient and health system. PMID:27748157

Direct Observation of a Carbon Filament in Water-Resistant Organic Memory.

PubMed

Lee, Byung-Hyun; Bae, Hagyoul; Seong, Hyejeong; Lee, Dong-Il; Park, Hongkeun; Choi, Young Joo; Im, Sung-Gap; Kim, Sang Ouk; Choi, Yang-Kyu

2015-07-28

The memory for the Internet of Things (IoT) requires versatile characteristics such as flexibility, wearability, and stability in outdoor environments. Resistive random access memory (RRAM) to harness a simple structure and organic material with good flexibility can be an attractive candidate for IoT memory. However, its solution-oriented process and unclear switching mechanism are critical problems. Here we demonstrate iCVD polymer-intercalated RRAM (i-RRAM). i-RRAM exhibits robust flexibility and versatile wearability on any substrate. Stable operation of i-RRAM, even in water, is demonstrated, which is the first experimental presentation of water-resistant organic memory without any waterproof protection package. Moreover, the direct observation of a carbon filament is also reported for the first time using transmission electron microscopy, which puts an end to the controversy surrounding the switching mechanism. Therefore, reproducibility is feasible through comprehensive modeling. Furthermore, a carbon filament is superior to a metal filament in terms of the design window and selection of the electrode material. These results suggest an alternative to solve the critical issues of organic RRAM and an optimized memory type suitable for the IoT era.

Ground-Based Observations of Terrestrial Gamma Ray Flashes Associated with Downward-Directed Lightning Leaders

NASA Astrophysics Data System (ADS)

Belz, J.; Abbasi, R.; Krehbiel, P. R.; LeVon, R.; Remington, J.; Rison, W.; Thomas, R. J.

2017-12-01

and energy measurement, simulation studies indicate that the fluxes and forward-beaming observed are consistent with production in processes such as the relativistic runaway electron avalanche. We conclude that the anomalous triggers observed by TA are most likely downward-directed Terrestrial Gamma Flashes.

Unimolecular thermal decomposition of phenol and d5-phenol: Direct observation of cyclopentadiene formation via cyclohexadienone

NASA Astrophysics Data System (ADS)

Scheer, Adam M.; Mukarakate, Calvin; Robichaud, David J.; Nimlos, Mark R.; Carstensen, Hans-Heinrich; Barney Ellison, G.

2012-01-01

The pyrolyses of phenol and d5-phenol (C6H5OH and C6D5OH) have been studied using a high temperature, microtubular (μtubular) SiC reactor. Product detection is via both photon ionization (10.487 eV) time-of-flight mass spectrometry and matrix isolation infrared spectroscopy. Gas exiting the heated reactor (375 K-1575 K) is subject to a free expansion after a residence time in the μtubular reactor of approximately 50-100 μs. The expansion from the reactor into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. We find that the initial decomposition steps at the onset of phenol pyrolysis are enol/keto tautomerization to form cyclohexadienone followed by decarbonylation to produce cyclopentadiene; C6H5OH → c-C6H6 = O → c-C5H6 + CO. The cyclopentadiene loses a H atom to generate the cyclopentadienyl radical which further decomposes to acetylene and propargyl radical; c-C5H6 → c-C5H5 + H → HC≡CH + HCCCH2. At higher temperatures, hydrogen loss from the PhO-H group to form phenoxy radical followed by CO ejection to generate the cyclopentadienyl radical likely contributes to the product distribution; C6H5O-H → C6H5O + H → c-C5H5 + CO. The direct decarbonylation reaction remains an important channel in the thermal decomposition mechanisms of the dihydroxybenzenes. Both catechol (o-HO-C6H4-OH) and hydroquinone (p-HO-C6H4-OH) are shown to undergo decarbonylation at the onset of pyrolysis to form hydroxycyclopentadiene. In the case of catechol, we observe that water loss is also an important decomposition channel at the onset of pyrolysis.

Direct observation of the ferroelectric polarization in the layered perovskite Bi{sub 4}Ti{sub 3}O{sub 12}

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

Urushihara, Daisuke; Asaka, Toru, E-mail: asaka.toru@nitech.ac.jp; Frontier Research Institute for Materials Science, Nagoya Institute of Technology, Nagoya 466-8555

We investigated the crystal structure and ferroelectric domains of Bi{sub 4}Ti{sub 3}O{sub 12} (BTO) by means of transmission electron microscopy (TEM) and single-crystal X-ray diffractometry. From the extinction rule, we determined that the space group in the ferroelectric phase of BTO is P1a1 rather than B2cb and B1a1 which have been proposed previously. We successfully refined the crystal structure based on the space group P1a1. The 180° and 90° ferroelectric domain structures were observed by the [001]-zone dark-field TEM imaging. In the 180° domain structure, we determined that one component of the polarization vector is parallel to the a-axis. Anmore » annular bright-field scanning transmission electron microscopy (ABF-STEM) was performed for the direct observation of the crystal structures. The ABF-STEM images displayed the contrasts with respect to every atomic position in spite of the highly distorted structure of BTO. We could evaluate the tilting and distortion of the [TiO{sub 6}] octahedra relatively. Therefore, we directly observed the ferroelectric displacements of Bi and Ti ions.« less

The exit interview as a proxy measure of malaria case management practice: sensitivity and specificity relative to direct observation.

PubMed

Pulford, Justin; Siba, Peter M; Mueller, Ivo; Hetzel, Manuel W

2014-12-03

This paper aims to assess the sensitivity and specificity of exit interviews as a measure of malaria case management practice as compared to direct observation. The malaria case management of 1654 febrile patients attending 110 health facilities from across Papua New Guinea was directly observed by a trained research officer as part of a repeat cross sectional survey. Patient recall of 5 forms of clinical advice and 5 forms of clinical action were then assessed at service exit and statistical analyses on matched observation/exit interview data conducted. The sensitivity of exit interviews with respect to clinical advice ranged from 36.2% to 96.4% and specificity from 53.5% to 98.6%. With respect to clinical actions, sensitivity of the exit interviews ranged from 83.9% to 98.3% and specificity from 70.6% to 98.1%. The exit interview appears to be a valid measure of objective malaria case management practices such as the completion of a diagnostic test or the provision of antimalarial medication, but may be a less valid measure of low frequency, subjective practices such as the provision of malaria prevention advice.

Direct observations of gas-hydrate formation in natural porous media on the micro-scale

NASA Astrophysics Data System (ADS)

Chaouachi, M.; Sell, K.; Falenty, A.; Enzmann, F.; Kersten, M.; Pinzer, B.; Saenger, E. H.; Kuhs, W. F.

2013-12-01

Gas hydrates (GH) are crystalline, inclusion compounds consisting of hydrogen-bonded water network encaging small gas molecules such as methane, ethane, CO2, etc (Sloan and Koh 2008). Natural gas hydrates are found worldwide in marine sediments and permafrost regions as a result of a reaction of biogenic or thermogenic gas with water under elevated pressure. Although a large amount of research on GH has been carried out over the years, the micro-structural aspects of GH growth, and in particular the contacts with the sedimentary matrix as well as the details of the distribution remain largely speculative. The present study was undertaken to shed light onto the well-established but not fully understood seismic anomalies, in particular the unusual attenuation of seismic waves in GH-bearing sediments, which may well be linked to micro-structural features. Observations of in-situ GH growth have been performed in a custom-build pressure cell (operating pressures up to several bar) mounted at the TOMCAT beam line of SLS/ PSI. In order to provide sufficient absorption contrast between phases and reduce pressure requirements for the cell we have used Xe instead of CH4. To the best of our knowledge this represents the first direct observation of GH growth in natural porous media with sub-micron spatial resolution and gives insight into the nucleation location and growth process of GH. The progress of the formation of sI Xe-hydrate in natural quartz sand was observed with a time-resolution of several minutes; the runs were conducted with an excess of a free-gas phase and show that the nucleation starts at the gas-water interface. Initially, a GH film is formed at this interface with a typical thickness of several μm; this film may well be permeable to gas as suggested in the past - which would explain the rapid transport of gas molecules for further conversion of water to hydrate, completed in less than 20 min. Clearly, initially the growth is directed mainly into the

Observing the operational significance of discord consumption

NASA Astrophysics Data System (ADS)

Gu, Mile; Chrzanowski, Helen M.; Assad, Syed M.; Symul, Thomas; Modi, Kavan; Ralph, Timothy C.; Vedral, Vlatko; Lam, Ping Koy

2012-09-01

Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this information by any other means allows us to use discord to directly quantify this `quantum advantage'. We experimentally encode information within the discordant correlations of two separable Gaussian states. The amount of extra information recovered by coherent interaction is quantified and directly linked with the discord consumed during encoding. No entanglement exists at any point of this experiment. Thus we introduce and demonstrate an operational method to use discord as a physical resource.

Statistical study of muons counts rates in differents directions, observed at the Brazilian Southern Space Observatory

NASA Astrophysics Data System (ADS)

Grams, Guilherme; Schuch, Nelson Jorge; Braga, Carlos Roberto; Purushottam Kane, Rajaram; Echer, Ezequiel; Ronan Coelho Stekel, Tardelli

Cosmic ray are charged particles, at the most time protons, that reach the earth's magne-tosphere from interplanetary space with velocities greater than the solar wind. When these impinge the atmosphere, they interact with atmosphere constituents and decay into sub-particles forming an atmospheric shower. The muons are the sub-particles which normally maintain the originated direction of the primary cosmic ray. A multi-directional muon detec-tor (MMD) was installed in 2001 and upgraded in 2005, through an international cooperation between Brazil, Japan and USA, and operated since then at the Southern Space Observatory -SSO/CRS/CCR/INPE -MCT, (29,4° S, 53,8° W, 480m a.s.l.), São Martinho da Serra, RS, a Brazil. The main objetive of this work is to present a statistical analysis of the intensity of muons, with energy between 50 and 170 GeV, in differents directions, measured by the SSO's multi-directional muon detector. The analysis was performed with data from 2006 and 2007 collected by the SSO's MMD. The MMD consists of two layers of 4x7 detectors with a total observation area of 28 m2 . The counting of muons in each directional channel is made by a coincidence of pulses pair, one from a detector in the upper layer and the other from a detector in the lower layer. The SSO's MMD is equipped with 119 directional channels for muon count rate measurement and is capable of detecting muons incident with zenithal angle between 0° and 75,53° . A statistical analysis was made with the MMD muon count rate for all the di-rectional channels. The average and the standard deviation of the muon count rate in each directional component were calculated. The results show lower cont rate for the channels with larger zenith, and higher cont rate with smaller zenith, as expected from the production and propagation of muons in the atmosphere. It is also possible to identify the Stormer cone. The SSO's MMD is also a detector component of the Global Muon Detector Network (GMDN

Allowance market pricing indicators

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

Miller, R.W.

1995-12-31

Regardless of whether buyers and sellers rely on one allowance price indicator or a combination of several, the publication of price indicators has facilitated trading in the SO{sub 2} allowance market. Buyers and sellers feel more comfortable with a price benchmark against which to measure their actions; liquidity has increased; and transactions are easier to conclude. At this market`s present stage of development, five price indicators are worthy of discussion: EPA Allowance Auctions; Compliance Strategies Review`s EATX; Utility Environment Report`s price range; Cantor Fitzgerald`s Allowance Price Indicators; and Emissions Exchange Corporation`s Exchange Values. But experience in other markets indicates thatmore » (1) others will be created as the market develops, and (2) all published price indicators will tend to converge as time passes.« less

Observer-based perturbation extremum seeking control with input constraints for direct-contact membrane distillation process

NASA Astrophysics Data System (ADS)

Eleiwi, Fadi; Laleg-Kirati, Taous Meriem

2018-06-01

An observer-based perturbation extremum seeking control is proposed for a direct-contact membrane distillation (DCMD) process. The process is described with a dynamic model that is based on a 2D advection-diffusion equation model which has pump flow rates as process inputs. The objective of the controller is to optimise the trade-off between the permeate mass flux and the energy consumption by the pumps inside the process. Cases of single and multiple control inputs are considered through the use of only the feed pump flow rate or both the feed and the permeate pump flow rates. A nonlinear Lyapunov-based observer is designed to provide an estimation for the temperature distribution all over the designated domain of the DCMD process. Moreover, control inputs are constrained with an anti-windup technique to be within feasible and physical ranges. Performance of the proposed structure is analysed, and simulations based on real DCMD process parameters for each control input are provided.

Chandra Observation of an X-ray Flare at Saturn: Evidence for Direct Solar Control on Saturn's Disk X-ray Emissions

NASA Technical Reports Server (NTRS)

Bhardwaj, Anil; Elsner, Ronald F.; Waite, J. Hunter, Jr.; Gladstone, G. Randall; Cravens, Thomas E.; Ford, Peter G.

2005-01-01

Saturn was observed by Chandra ACIS-S on 20 and 26-27 January 2004 for one full Saturn rotation (10.7 hr) at each epoch. We report here the first observation of an X-ray flare from Saturn s non-auroral (low-latitude) disk, which is seen in direct response to an M6-class flare emanating from a sunspot that was clearly visible from both Saturn and Earth. Saturn s X-ray emissions are found to be highly variable on time scales of tens of minutes to weeks. Unlike Jupiter, X-rays from Saturn s polar (auroral) region have characteristics similar to those from its disk and varies in brightness inversely to the FUV auroral emissions observed by the Hubble Space Telescope. This report establishes that disk X-ray emissions of the giant planets Saturn and Jupiter are directly regulated by processes happening on the Sun. We suggest that these emissions could be monitored to study X-ray flaring from solar active regions when they are on the far side and not visible to Near-Earth space weather satellites.

Chemotaxis study using optical tweezers to observe the strength and directionality of forces of Leishmania amazonensis

NASA Astrophysics Data System (ADS)

Pozzo, Liliana d. Y.; Fontes, Adriana; de Thomaz, André A.; Barbosa, Luiz C.; Ayres, Diana C.; Giorgio, Selma; Cesar, Carlos L.

2006-08-01

The displacements of a dielectric microspheres trapped by an optical tweezers (OT) can be used as a force transducer for mechanical measurements in life sciences. This system can measure forces on the 50 femto Newtons to 200 pico Newtons range, of the same order of magnitude of a typical forces induced by flagellar motion. The process in which living microorganisms search for food and run away from poison chemicals is known is chemotaxy. Optical tweezers can be used to obtain a better understanding of chemotaxy by observing the force response of the microorganism when placed in a gradient of attractors and or repelling chemicals. This report shows such observations for the protozoa Leishmania amazomenzis, responsible for the leishmaniasis, a serious tropical disease. We used a quadrant detector to monitor the movement of the protozoa for different chemicals gradient. This way we have been able to observe both the force strength and its directionality. The characterization of the chemotaxis of these parasites can help to understand the infection mechanics and improve the diagnosis and the treatments employed for this disease.

Direct radiative effects of aerosols over South Asia from observations and modeling

NASA Astrophysics Data System (ADS)

Nair, Vijayakumar S.; Babu, S. Suresh; Manoj, M. R.; Moorthy, K. Krishna; Chin, Mian

2017-08-01

Quantitative assessment of the seasonal variations in the direct radiative effect (DRE) of composite aerosols as well as the constituent species over the Indian sub continent has been carried out using a synergy of observations from a dense network of ground based aerosol observatories and modeling based on chemical transport model simulations. Seasonal variation of aerosol constituents depict significant influence of anthropogenic aerosol sources in winter and the dominance of natural sources in spring, even though the aerosol optical depth doesn't change significantly between these two seasons. A significant increase in the surface cooling and atmospheric warming has been observed as season changes from winter (DRESUR = -28 ± 12 W m-2 and DREATM = +19.6 ± 9 W m-2) to spring (DRESUR = -33.7 ± 12 W m-2 and DREATM = +27 ± 9 W m-2). Interestingly, springtime aerosols are more absorptive in nature compared to winter and consequently the aerosol induced diabatic heating of the atmosphere goes as high as 1 K day-1 during spring, especially over eastern India. The atmospheric DRE due to dust aerosols (+14 ± 7 W m-2) during spring overwhelms that of black carbon DRE (+11.8 ± 6 W m-2) during winter. The DRE at the top of the atmosphere is mostly governed by the anthropogenic aerosols during all the seasons. The columnar aerosol loading, its anthropogenic fraction and radiative effects shows a steady increase with latitude across Indian mainland leading to a larger aerosol-induced atmospheric warming during spring than in winter.

Direct single-molecule observation of calcium-dependent misfolding in human neuronal calcium sensor-1.

PubMed

Heidarsson, Pétur O; Naqvi, Mohsin M; Otazo, Mariela R; Mossa, Alessandro; Kragelund, Birthe B; Cecconi, Ciro

2014-09-09

Neurodegenerative disorders are strongly linked to protein misfolding, and crucial to their explication is a detailed understanding of the underlying structural rearrangements and pathways that govern the formation of misfolded states. Here we use single-molecule optical tweezers to monitor misfolding reactions of the human neuronal calcium sensor-1, a multispecific EF-hand protein involved in neurotransmitter release and linked to severe neurological diseases. We directly observed two misfolding trajectories leading to distinct kinetically trapped misfolded conformations. Both trajectories originate from an on-pathway intermediate state and compete with native folding in a calcium-dependent manner. The relative probability of the different trajectories could be affected by modulating the relaxation rate of applied force, demonstrating an unprecedented real-time control over the free-energy landscape of a protein. Constant-force experiments in combination with hidden Markov analysis revealed the free-energy landscape of the misfolding transitions under both physiological and pathological calcium concentrations. Remarkably for a calcium sensor, we found that higher calcium concentrations increased the lifetimes of the misfolded conformations, slowing productive folding to the native state. We propose a rugged, multidimensional energy landscape for neuronal calcium sensor-1 and speculate on a direct link between protein misfolding and calcium dysregulation that could play a role in neurodegeneration.

Direct Single-Molecule Observation of Mode and Geometry of RecA-Mediated Homology Search.

PubMed

Lee, Andrew J; Endo, Masayuki; Hobbs, Jamie K; Wälti, Christoph

2018-01-23

Genomic integrity, when compromised by accrued DNA lesions, is maintained through efficient repair via homologous recombination. For this process the ubiquitous recombinase A (RecA), and its homologues such as the human Rad51, are of central importance, able to align and exchange homologous sequences within single-stranded and double-stranded DNA in order to swap out defective regions. Here, we directly observe the widely debated mechanism of RecA homology searching at a single-molecule level using high-speed atomic force microscopy (HS-AFM) in combination with tailored DNA origami frames to present the reaction targets in a way suitable for AFM-imaging. We show that RecA nucleoprotein filaments move along DNA substrates via short-distance facilitated diffusions, or slides, interspersed with longer-distance random moves, or hops. Importantly, from the specific interaction geometry, we find that the double-stranded substrate DNA resides in the secondary DNA binding-site within the RecA nucleoprotein filament helical groove during the homology search. This work demonstrates that tailored DNA origami, in conjunction with HS-AFM, can be employed to reveal directly conformational and geometrical information on dynamic protein-DNA interactions which was previously inaccessible at an individual single-molecule level.

ALMA observations of molecular absorption in four directions toward the Galactic bulge

NASA Astrophysics Data System (ADS)

Liszt, H.; Gerin, M.

2018-02-01

Context. Alma Cycle 3 observations serendipitously showed strong absorption from diffuse molecular gas in the Galactic bulge at -200 km s-1 < v < -140 km s-1 toward the compact extragalactic continuum source J1744-3116 at (l, b) = -2.13∘, - 1.00∘. Aims: We aimed to test whether molecular gas in the bulge could also be detected toward the three other, sufficiently strong mm-wave continuum sources seen toward the bulge at |b| < 3∘. Methods: We took absorption profiles of HCO+ (1-0), HCN(1-0), C2H(1-0), CS(2-1) and H13CO+(1-0) in ALMA Cycle 4 toward J1713-3418, J1717-3341, J1733-3722 and J1744-3116. Results: Strong molecular absorption from disk gas at |ν| ≲ 30 km s-1 was detected in all directions, and absorption from the 3 kpc arm was newly detected toward J1717 and J1744. However, only the sightline toward J1744 is dominated by molecular gas overall and no other sightlines showed molecular absorption from gas deep inside the bulge. No molecular absorption was detected toward J1717 where H I emission from the bulge was previously known. As observed in HCO+, HCN, C2H and CS, the bulge gas toward J1744 at v < -135 km s-1 has chemistry and kinematics like that seen near the Sun and in the Milky Way disk generally. We measured isotopologic ratios N(HCO+)/N(H13CO+) > 51(3σ) for the bulge gas toward J1744 and 58 ± 9 and 64 ± 4 for the disk gas toward J1717 and J1744, respectively, all well above the value of 20-25 typical of the central molecular zone. Conclusions: The kinematics and chemistry of the bulge gas observed toward J1744 more nearly resemble that of gas in the Milky Way disk than in the central molecular zone.

Direct observation of the discrete energy spectrum of two lanthanide-based single-chain magnets by far-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Haas, Sabrina; Heintze, Eric; Zapf, Sina; Gorshunov, Boris; Dressel, Martin; Bogani, Lapo

2014-05-01

The far-infrared optical transmission has been studied for two lanthanide-based single-chain magnets DyPhOPh and TbPhOPh in the frequency range between 3 and 80 cm-1. The spectra were acquired at temperatures between 2 and 80 K and magnetic fields up to 6 T. Based on their magnetic field dependence in DyPhOPh two of the observed absorption lines are identified as transitions inside the crystal field split Dy3+ ground multiplet 6H15/2, coupled to the neighboring spins. In TbPhOPh one transition was observed inside the crystal-field-split Tb3+ ground multiplet 7F6. The results allow a spectroscopic investigation of the role of single-ion anisotropy and exchange in Glauber dynamics.

The allowance exchange - ALEX

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

Mangis, J.K.; Miller, C.; Nicholas, J.

1997-12-31

The success of market approaches to pollution control in reducing the cost of compliance with environmental regulation, has insured the inclusion of emissions trading programs in current and future regulatory programs. As these environmental trading programs multiply, (SO{sub 2}, NO{sub x}, Ozone Precursors, Wetlands, CO{sub 2} and others), utility companies will need a central location to buy, sell, and trade these allowances to meet regulatory needs. In response, SAIC has designed and prototyped an electronic trading system that can provide a common forum for the location and exchange of environmental allowances, marketable permits, and other market based instruments for environmentalmore » management. SAIC intends to open and operate the Allowance Exchange (ALEX) for the trading of all environmental allowances, associated with the operation of electric utilities, as a service to the nation, the industry, and the environmental community.« less

Direct observation of growth and collapse of a Bose-Einstein condensate with attractive interactions

NASA Astrophysics Data System (ADS)

Gerton, Jordan M.; Strekalov, Dmitry; Prodan, Ionut; Hulet, Randall G.

2000-12-01

Quantum theory predicts that Bose-Einstein condensation of a spatially homogeneous gas with attractive interactions is precluded by a conventional phase transition into either a liquid or solid. When confined to a trap, however, such a condensate can form, provided that its occupation number does not exceed a limiting value. The stability limit is determined by a balance between the self-attractive forces and a repulsion that arises from position-momentum uncertainty under conditions of spatial confinement. Near the stability limit, self-attraction can overwhelm the repulsion, causing the condensate to collapse. Growth of the condensate is therefore punctuated by intermittent collapses that are triggered by either macroscopic quantum tunnelling or thermal fluctuation. Previous observations of growth and collapse dynamics have been hampered by the stochastic nature of these mechanisms. Here we report direct observations of the growth and subsequent collapse of a 7Li condensate with attractive interactions, using phase-contrast imaging. The success of the measurement lies in our ability to reduce the stochasticity in the dynamics by controlling the initial number of condensate atoms using a two-photon transition to a diatomic molecular state.

Direct Observation of Quark-Hadron Duality in the Free Neutron {ital F}{sub 2} Structure Function

DOE PAGES

Niculescu, I.; Niculescu, G.; Melnitchouk, W.; ...

2015-05-21

Using the recently published data from the BONuS(Barely Off-shell Nucleon Structure) experiment at Jefferson Lab, which utilized a spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F-2 structure function. The data are used to reconstruct the lowest few (N = 2, 4, and 6) moments of F-2 in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark-hadron duality holds locally for themore » neutron in the second and third resonance regions down to Q(2) approximate to 1 GeV2, with violations possibly up to 20% observed in the first resonance region.« less

Optimization study of direct morphology observation by cold field emission SEM without gold coating.

PubMed

He, Dan; Fu, Cheng; Xue, Zhigang

2018-06-01

Gold coating is a general operation that is generally applied on non-conductive or low conductive materials, during which the morphology of the materials can be examined by scanning electron microscopy (SEM). However, fatal deficiencies in the materials can result in irreversible distortion and damage. The present study directly characterized different low conductive materials such as hydroxyapatite, modified poly(vinylidene fluoride) (PVDF) fiber, and zinc oxide nanopillar by cold field emission scanning electron microscopy (FE-SEM) without a gold coating. According to the characteristics of the low conductive materials, various test conditions, such as different working signal modes, accelerating voltages, electron beam spots, and working distances, were characterized to determine the best morphological observations of each sample. Copyright © 2018 Elsevier Ltd. All rights reserved.

Direct Manipulation in Virtual Reality

NASA Technical Reports Server (NTRS)

Bryson, Steve

2003-01-01

Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

Overseas Cost of Living Allowances (COLA)

Science.gov Websites

) Government Meal Rate Meal Tickets Mileage Rates Overseas Cost of Living Allowances (COLA) Calculation of Reporting Procedures Station Allowance Changes Programs & Services > Allowances > Overseas Cost of Allowances Submit Questions Overseas Cost of Living Allowances (COLA) The Overseas Cost of Living Allowance

7 CFR 205.601 - Synthetic substances allowed for use in organic crop production.

Code of Federal Regulations, 2010 CFR

2010-01-01

... or soil. (2) Boric acid—structural pest control, no direct contact with organic food or crops. (3... 7 Agriculture 3 2010-01-01 2010-01-01 false Synthetic substances allowed for use in organic crop... (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Administrative The National List...

[Preliminary study on detox in outpatient care units with 18 alcoholic patients in Directly Observed Treatment].

PubMed

Lloréns Martínez, Ramón; Calatayud Francés, María; Morales Gallús, Esperanza; Añó Cervera, Consol; Adriá Caballero, Librada

2008-01-01

Directly Observed Treatment (TOD-DOT) has been tested in different conditions. The objective of this work is to check whether a UCA-CAB (Centre for Addictive Behaviour) can achieve detox and reduce the risk of early relapse (up to 12 weeks) in alcoholic patients. All patients had an established organic addiction and serious withdrawal syndrome, and had undergone multiple previous treatments. Furthermore, they had not managed to abstain for a 3-month consecutive period over the previous 2 years. The aim of the Directly Observed Treatment was to attain detox and reduce relapse by following a multi-method approach: medical, psychological and personal care, based on a brief daily consultation and pharmacological supervision. The results were as follows: Of the 18 patients included in the study, after 12 weeks, 13 (72 %) were still abstinent and 4 (22 %) had relapsed. Thus, 17 (94 %) were still following the treatment, with just one drop-out. We analysed the profiles of the patients abstaining, of those who relapsed (4) and of the one who dropped out. The average CIWA-Ar was 27.05 (21-36). Any value over 20 is considered to indicate serious withdrawal syndrome, though there were no negative events leading to hospitalization. Level of adherence to the treatment (94 %) meant that the most seriously affected patients and those with fewest financial resources could benefit, not only from any auxiliary social schemes, but also from basic health services, permitting them to improve the quality of their everyday life.

DIRECT OBSERVATION OF SOLAR CORONAL MAGNETIC FIELDS BY VECTOR TOMOGRAPHY OF THE CORONAL EMISSION LINE POLARIZATIONS

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

Kramar, M.; Lin, H.; Tomczyk, S., E-mail: kramar@cua.edu, E-mail: lin@ifa.hawaii.edu, E-mail: tomczyk@ucar.edu

We present the first direct “observation” of the global-scale, 3D coronal magnetic fields of Carrington Rotation (CR) Cycle 2112 using vector tomographic inversion techniques. The vector tomographic inversion uses measurements of the Fe xiii 10747 Å Hanle effect polarization signals by the Coronal Multichannel Polarimeter (CoMP) and 3D coronal density and temperature derived from scalar tomographic inversion of Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) coronal emission lines (CELs) intensity images as inputs to derive a coronal magnetic field model that best reproduces the observed polarization signals. While independent verifications of the vector tomography results cannot be performed, wemore » compared the tomography inverted coronal magnetic fields with those constructed by magnetohydrodynamic (MHD) simulations based on observed photospheric magnetic fields of CR 2112 and 2113. We found that the MHD model for CR 2112 is qualitatively consistent with the tomography inverted result for most of the reconstruction domain except for several regions. Particularly, for one of the most noticeable regions, we found that the MHD simulation for CR 2113 predicted a model that more closely resembles the vector tomography inverted magnetic fields. In another case, our tomographic reconstruction predicted an open magnetic field at a region where a coronal hole can be seen directly from a STEREO-B/EUVI image. We discuss the utilities and limitations of the tomographic inversion technique, and present ideas for future developments.« less

Direct measurements on imaging riometer antenna array beam directivities

NASA Astrophysics Data System (ADS)

Wilson, A.; Nel, J. J.; Mathews, M. J.; Stoker, P. H.

2001-01-01

Spatial structures in enhanced ionization of the ionosphere are observed by absorption of cosmic radio waves. These structures are resolved by using theoretically derived imaging riometer antenna array directivities. These directivities are calculated from beam phasing of 64 crossed dipole elements of the 38.2-MHz antenna array at SANAE IV, Antarctica. In order to ensure that these derived directivities are representative of the actual viewing directions of the 64-beams, a radio transmitter was flown by helicopter across the antenna array. In this paper variations in the receiver signal strengths, recorded when flying across beam-viewing directions, are compared with the spatial and angular-dependent profiles of expected receiver output responses, derived theoretically from the directivities of the antenna array. A Global Positioning System (GPS) device on board the helicopter was used for positional recording. The derived and recorded profiles did coincide occasionally, but at other instances relative displacements and differences in magnitude of responses were observed. These displacements and differences could be attributed to degradation in position fixes imposed deliberately by selective availability on the GPS system. Excellent coincidence for a number of beam crossings proved that the viewing directions are accurate in all the beam directions, since the multi-dimensional Butler matrix produces 64 simultaneous beams.

JEOS. The JANUS earth observation satellite

NASA Astrophysics Data System (ADS)

Molette, P.; Jouan, J.

The JANUS multimission platform has been designed to minimize the cost of the satellite (by a maximum reuse of equipment from other proprogrammes) and of its associated launch by Aŕiane (by a piggy-back configuration optimized for Ariane 4). The paper describes the application of the JANUS platform to an Earth observation mission with the objective to provide a given country with a permanent monitoring of its earth resources by exploitation of spaceborne imagery. According to this objective, and to minimize the overall system and operational cost, the JANUS Earth Observation Satellite (JEOS) will provide a limited coverage with real time transmission of image data, thus avoiding need for on-board storage and simplifying operations. The JEOS operates on a low earth, near polar sun synchronous orbit. Launched in a piggy-back configuration on Ariane 4, with a SPOT or ERS spacecraft, it reaches its operational orbit after a drift orbit of a few weeks maximum. In its operational mode, the JEOS is 3-axis stabilised, earth pointed. After presentation of the platform, the paper describes the solid state push-broom camera which is composed of four optical lenses mounted on a highly stable optical bench. Each lens includes an optics system, reused from an on-going development, and two CCD linear arrays of detectors. The camera provides four registered channels in visible and near IR bands. The whole optical bench is supported by a rotating mechanism which allows rotation of the optical axis in the across-track direction. The JEOS typical performance for a 700 km altitude is then summarized: spatial resolution 30 m, swath width 120 km, off-track capability 325 km,… The payload data handling and transmission electronics, derived from the French SPOT satellite, realizes the processing, formatting, and transmission to the ground; this allows reuse of the standard SPOT receiving stations. The camera is only operated when the spacecraft is within the visibility of the ground

EarthObserver: Bringing the world to your fingertips

NASA Astrophysics Data System (ADS)

Ryan, W. B.; Goodwillie, A. M.; Coplan, J.; Carbotte, S. M.; Arko, R. A.; Ferrini, V.; O'hara, S. H.; Chan, S.; Bonczkowski, J.; Nitsche, F. O.; Morton, J. J.; McLain, K.; Weissel, R.

2011-12-01

EarthObserver (http://www.earth-observer.org/), developed by the Lamont-Doherty Earth Observatory of Columbia University, brings a wealth of geoscience data to Apple iPad, iPhone and iPod Touch mobile devices. Built around an easy-to-use interface, EarthObserver allows users to explore and visualise a wide range of data sets superimposed upon a detailed base map of land elevations and ocean depths - tapping the screen will instantly return the height or depth at that point. A simple transparency function allows direct comparison of built-in content. Data sets include high-resolution coastal bathymetry of bays, sounds, estuaries, harbors and rivers; geological maps of the US states and world - tapping the screen displays the rock type, and full legends can be viewed; US Topo sheets; and, geophysical content including seafloor crustal age and sediment thickness, earthquake and volcano data, gravity and magnetic anomalies, and plate boundary descriptions. The names of physiographic features are automatically displayed. NASA Visible Earth images along with ocean temperature, salinity and productivity maps and precipitation information expose data sets of interest to the atmospheric, oceanic and biological communities. Natural hazard maps, population information and political boundaries allow users to explore impacts upon society. EarthObserver, so far downloaded by more than 55,000 users, offers myriad ways for educators at all levels to bring research-quality geoscience data into the learning environment, whether for use as an in-class illustration or for extensive exploration of earth sciences data. By using cutting-edge mobile app technology, EarthObserver boosts access to relevant earth science content. The EarthObserver base map is the Global Multi-Resolution Topography digital elevation model (GMRT; http://www.marine-geo.org/portals/gmrt/), also developed at LDEO and updated regularly. It provides land elevations with horizontal resolution as high as 10m for

Anisotropy in Fracking: A Percolation Model for Observed Microseismicity

NASA Astrophysics Data System (ADS)

Norris, J. Quinn; Turcotte, Donald L.; Rundle, John B.

2015-01-01

Hydraulic fracturing (fracking), using high pressures and a low viscosity fluid, allow the extraction of large quantiles of oil and gas from very low permeability shale formations. The initial production of oil and gas at depth leads to high pressures and an extensive distribution of natural fractures which reduce the pressures. With time these fractures heal, sealing the remaining oil and gas in place. High volume fracking opens the healed fractures allowing the oil and gas to flow to horizontal production wells. We model the injection process using invasion percolation. We use a 2D square lattice of bonds to model the sealed natural fractures. The bonds are assigned random strengths and the fluid, injected at a point, opens the weakest bond adjacent to the growing cluster of opened bonds. Our model exhibits burst dynamics in which the clusters extend rapidly into regions with weak bonds. We associate these bursts with the microseismic activity generated by fracking injections. A principal object of this paper is to study the role of anisotropic stress distributions. Bonds in the y-direction are assigned higher random strengths than bonds in the x-direction. We illustrate the spatial distribution of clusters and the spatial distribution of bursts (small earthquakes) for several degrees of anisotropy. The results are compared with observed distributions of microseismicity in a fracking injection. Both our bursts and the observed microseismicity satisfy Gutenberg-Richter frequency-size statistics.

Direct observation of nanowire growth and decomposition.

PubMed

Rackauskas, Simas; Shandakov, Sergey D; Jiang, Hua; Wagner, Jakob B; Nasibulin, Albert G

2017-09-26

Fundamental concepts of the crystal formation suggest that the growth and decomposition are determined by simultaneous embedding and removal of the atoms. Apparently, by changing the crystal formation conditions one can switch the regimes from the growth to decomposition. To the best of our knowledge, so far this has been only postulated, but never observed at the atomic level. By means of in situ environmental transmission electron microscopy we monitored and examined the atomic layer transformation at the conditions of the crystal growth and its decomposition using CuO nanowires selected as a model object. The atomic layer growth/decomposition was studied by varying an O 2 partial pressure. Three distinct regimes of the atomic layer evolution were experimentally observed: growth, transition and decomposition. The transition regime, at which atomic layer growth/decomposition switch takes place, is characterised by random nucleation of the atomic layers on the growing {111} surface. The decomposition starts on the side of the nanowire by removing the atomic layers without altering the overall crystal structure, which besides the fundamental importance offers new possibilities for the nanowire manipulation. Understanding of the crystal growth kinetics and nucleation at the atomic level is essential for the precise control of 1D crystal formation.

Direct Radiative Effects of Aerosols Over South Asia From Observations and Modeling

NASA Technical Reports Server (NTRS)

Nair, Vijayakumar S.; Babu, S. Suresh; Manoj, M. R.; Moorthy, Krishna K.; Chin, Mian

2016-01-01

Quantitative assessment of the seasonal variations in the direct radiative effect (DRE) of composite aerosols as well as the constituent species over the Indian sub continent has been carried out using a synergy of observations from a dense network of ground based aerosol observatories and modeling based on chemical transport model simulations. Seasonal variation of aerosol constituents depict significant influence of anthropogenic aerosol sources in winter and the dominance of natural sources in spring, even though the aerosol optical depth doesn't change significantly between these two seasons. A significant increase in the surface cooling and atmospheric warming has been observed as season changes from winter DRE(sub SUR) = -28 +/- 12 W m(exp -2) and DRE(sub ATM) = +19.6 +/- 9 W m(exp -2) to spring DRE(sub SUR) = -33.7 +/- 12 W m(exp -2) and DRE(sub ATM) = +27 +/- 9 W m(exp-2). Interestingly, springtime aerosols are more absorptive in nature compared to winter and consequently the aerosol induced diabatic heating of the atmosphere goes as high as approximately 1 K day(exp -1) during spring, especially over eastern India. The atmospheric DRE due to dust aerosols (+14 +/- 7 W m(exp 2) during spring overwhelms that of black carbon DRE (+11.8 +/- 6 W m(exp -2) during winter. The DRE at the top of the atmosphere is mostly governed by the anthropogenic aerosols during all the seasons. The columnar aerosol loading, its anthropogenic fraction and radiative effects shows a steady increase with latitude across Indian mainland leading to a larger aerosol-induced atmospheric warming during spring than in winter.

The Photochemical Reflectance Index from Directional Cornfield Reflectances: Observations and Simulations

NASA Technical Reports Server (NTRS)

Cheng, Yen-Ben; Middleton, Elizabeth M.; Zhang, Qingyuan; Corp, Lawrence A.; Dandois, Jonathan; Kustas, William P.

2012-01-01

The two-layer Markov chain Analytical Canopy Reflectance Model (ACRM) was linked with in situ hyperspectral leaf optical properties to simulate the Photochemical Reflectance Index (PRI) for a corn crop canopy at three different growth stages. This is an extended study after a successful demonstration of PRI simulations for a cornfield previously conducted at an early vegetative growth stage. Consistent with previous in situ studies, sunlit leaves exhibited lower PRI values than shaded leaves. Since sunlit (shaded) foliage dominates the canopy in the reflectance hotspot (coldspot), the canopy PRI derived from field hyperspectral observations displayed sensitivity to both view zenith angle and relative azimuth angle at all growth stages. Consequently, sunlit and shaded canopy sectors were most differentiated when viewed along the azimuth matching the solar principal plane. These directional PRI responses associated with sunlit/shaded foliage were successfully reproduced by the ACRM. As before, the simulated PRI values from the current study were closer to in situ values when both sunlit and shaded leaves were utilized as model input data in a two-layer mode, instead of a one-layer mode with sunlit leaves only. Model performance as judged by correlation between in situ and simulated values was strongest for the mature corn crop (r = 0.87, RMSE = 0.0048), followed by the early vegetative stage (r = 0.78; RMSE = 0.0051) and the early senescent stage (r = 0.65; RMSE = 0.0104). Since the benefit of including shaded leaves in the scheme varied across different growth stages, a further analysis was conducted to investigate how variable fractions of sunlit/shaded leaves affect the canopy PRI values expected for a cornfield, with implications for 20 remote sensing monitoring options. Simulations of the sunlit to shaded canopy ratio near 50/50 +/- 10 (e.g., 60/40) matching field observations at all growth stages were examined. Our results suggest in the importance of the

Parameter estimation method that directly compares gravitational wave observations to numerical relativity

NASA Astrophysics Data System (ADS)

Lange, J.; O'Shaughnessy, R.; Boyle, M.; Calderón Bustillo, J.; Campanelli, M.; Chu, T.; Clark, J. A.; Demos, N.; Fong, H.; Healy, J.; Hemberger, D. A.; Hinder, I.; Jani, K.; Khamesra, B.; Kidder, L. E.; Kumar, P.; Laguna, P.; Lousto, C. O.; Lovelace, G.; Ossokine, S.; Pfeiffer, H.; Scheel, M. A.; Shoemaker, D. M.; Szilagyi, B.; Teukolsky, S.; Zlochower, Y.

2017-11-01

We present and assess a Bayesian method to interpret gravitational wave signals from binary black holes. Our method directly compares gravitational wave data to numerical relativity (NR) simulations. In this study, we present a detailed investigation of the systematic and statistical parameter estimation errors of this method. This procedure bypasses approximations used in semianalytical models for compact binary coalescence. In this work, we use the full posterior parameter distribution for only generic nonprecessing binaries, drawing inferences away from the set of NR simulations used, via interpolation of a single scalar quantity (the marginalized log likelihood, ln L ) evaluated by comparing data to nonprecessing binary black hole simulations. We also compare the data to generic simulations, and discuss the effectiveness of this procedure for generic sources. We specifically assess the impact of higher order modes, repeating our interpretation with both l ≤2 as well as l ≤3 harmonic modes. Using the l ≤3 higher modes, we gain more information from the signal and can better constrain the parameters of the gravitational wave signal. We assess and quantify several sources of systematic error that our procedure could introduce, including simulation resolution and duration; most are negligible. We show through examples that our method can recover the parameters for equal mass, zero spin, GW150914-like, and unequal mass, precessing spin sources. Our study of this new parameter estimation method demonstrates that we can quantify and understand the systematic and statistical error. This method allows us to use higher order modes from numerical relativity simulations to better constrain the black hole binary parameters.

Knocking Combustion Observed in a Spark-Ignition Engine with Simultaneous Direct and Schlieren High-Speed Motion Pictures and Pressure Records

NASA Technical Reports Server (NTRS)

Osterstrom, Gordon E

1948-01-01

Simultaneous direct and Schlieren photographs at 40,000 frames per second and correlated pressure records were taken of knocking combustion in a special spark-ignition engine to ascertain the intensity of certain end-zone reactions previously noted from Schlieren photography alone. A violent propagated homogeneous autoignition, or a similar phenomenon, previously observed, was again observed. The pressure records show autoignition of varying violence before the passage of a probable detonation wave. Extensive autoignition without occurrence of gas vibrations was seen in one explosion.

A Ratiometric Two-Photon Fluorescent Probe for Tracking the Lysosomal ATP Level: Direct in cellulo Observation of Lysosomal Membrane Fusion Processes.

PubMed

Jun, Yong Woong; Wang, Taejun; Hwang, Sekyu; Kim, Dokyoung; Ma, Donghee; Kim, Ki Hean; Kim, Sungjee; Jung, Junyang; Ahn, Kyo Han

2018-06-05

Vesicles exchange its contents through membrane fusion processes-kiss-and-run and full-collapse fusion. Indirect observation of these fusion processes using artificial vesicles enhanced our understanding on the molecular mechanisms involved. Direct observation of the fusion processes in a real biological system, however, remains a challenge owing to many technical obstacles. We disclose a ratiometric two-photon probe offering real-time tracking of lysosomal ATP with quantitative information for the first time. By applying the probe to two-photon live-cell imaging technique, lysosomal membrane fusion process in cells has been directly observed along with the concentration of its content-lysosomal ATP. Results show that the kiss-and-run process between lysosomes proceeds through repeating transient interactions with gradual content mixing, whereas the full-fusion process occurs at once. Furthermore, it is confirmed that both the fusion processes proceed with conservation of the content. Such a small-molecule probe exerts minimal disturbance and hence has potential for studying various biological processes associated with lysosomal ATP. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rubber friction directional asymmetry

NASA Astrophysics Data System (ADS)

Tiwari, A.; Dorogin, L.; Steenwyk, B.; Warhadpande, A.; Motamedi, M.; Fortunato, G.; Ciaravola, V.; Persson, B. N. J.

2016-12-01

In rubber friction studies it is usually assumed that the friction force does not depend on the sliding direction, unless the substrate has anisotropic properties, like a steel surface grinded in one direction. Here we will present experimental results for rubber friction, where we observe a strong asymmetry between forward and backward sliding, where forward and backward refer to the run-in direction of the rubber block. The observed effect could be very important in tire applications, where directional properties of the rubber friction could be induced during braking.

Direct Observation of Asphaltene Nanoparticles on Model Mineral Substrates.

PubMed

Raj, Gijo; Lesimple, Alain; Whelan, Jamie; Naumov, Panče

2017-06-27

The propensity for adherence to solid surfaces of asphaltenes, a complex solubility class of heteropolycyclic aromatic compounds from the heavy fraction of crude oil, has long been the root cause of scale deposition and remains an intractable problem in the petroleum industry. Although the adhesion is essential to understanding the process of asphaltene deposition, the relationship between the conformation of asphaltene molecules on mineral substrates and its impact on adhesion and mechanical properties of the deposits is not completely understood. To rationalize the primary processes in the process of organic scale deposition, here we use atomic force microscopy (AFM) to visualize the morphology of petroleum asphaltenes deposited on model mineral substrates. High imaging contrast was achieved by the differential adhesion of the tip between asphaltenes and the mineral substrate. While asphaltenes form smooth continuous films on all substrates at higher concentrations, they deposit as individual nanoparticles at lower concentrations. The size, shape, and spatial distribution of the nanoaggregates are strongly affected by the nature of the substrate; while uniformly distributed spherical particles are formed on highly polar and hydrophilic substrates (mica), irregular islands and thicker patches are observed with substrates of lower polarity (silica and calcite). Asphaltene nanoparticles flatten when adsorbed on highly oriented pyrolytic graphite due to π-π interactions with the polycyclic core. Force-distance profiles provide direct evidence of the conformational changes of asphaltene molecules on hydrophilic/hydrophobic substrates that result in dramatic changes in adhesion and mechanical properties of asphaltene deposits. Such an understanding of the nature of adhesion and mechanical properties tuned by surface properties, on the level of asphaltene nanoaggregates, would contribute to the design of efficient asphaltene inhibitors for preventing asphaltene

Simultaneous observation of chemomechanical coupling of a molecular motor.

PubMed

Nishizaka, Takayuki; Hasimoto, Yuh; Masaike, Tomoko

2011-01-01

F(1)-ATPase is the smallest rotary molecular motor ever found. Unidirectional rotation of the γ-shaft is driven by precisely coordinated sequential ATP hydrolysis reactions in three catalytic sites arranged 120° apart in the cylinder. Single-molecule observation allows us to directly watch the rotation of the shaft using micron-sized plastic beads. Additionally, an advanced version of "total internal reflection fluorescence microscope (TIRFM)" enables us to detect binding and release of energy currency through fluorescently labeled ATP. In this chapter, we describe how to set up the system for simultaneous observation of these two critical events. This specialized optical setup is applicable to a variety of research, not only molecular motors but also other single-molecule topics.

A software tool to analyze clinical workflows from direct observations.

PubMed

Schweitzer, Marco; Lasierra, Nelia; Hoerbst, Alexander

2015-01-01

Observational data of clinical processes need to be managed in a convenient way, so that process information is reliable, valid and viable for further analysis. However, existing tools for allocating observations fail in systematic data collection of specific workflow recordings. We present a software tool which was developed to facilitate the analysis of clinical process observations. The tool was successfully used in the project OntoHealth, to build, store and analyze observations of diabetes routine consultations.

Directly observed treatment is associated with reduced default among foreign tuberculosis patients in Thailand.

PubMed

Kapella, B K; Anuwatnonthakate, A; Komsakorn, S; Moolphate, S; Charusuntonsri, P; Limsomboon, P; Wattanaamornkiat, W; Nateniyom, S; Varma, J K

2009-02-01

Thailand's Tuberculosis (TB) Active Surveillance Network in four provinces in Thailand. As treatment default is common in mobile and foreign populations, we evaluated risk factors for default among non-Thai TB patients in Thailand. Observational cohort study using TB program data. Analysis was restricted to patients with an outcome categorized as cured, completed, failure or default. We used multivariate analysis to identify factors associated with default, including propensity score analysis, to adjust for factors associated with receiving directly observed treatment (DOT). During October 2004-September 2006, we recorded data for 14359 TB patients, of whom 995 (7%) were non-Thais. Of the 791 patients analyzed, 313 (40%) defaulted. In multivariate analysis, age>or=45 years (RR 1.47, 95%CI 1.25-1.74), mobility (RR 2.36, 95%CI 1.77-3.14) and lack of DOT (RR 2.29, 95%CI 1.45-3.61) were found to be significantly associated with default among non-Thais. When controlling for propensity to be assigned DOT, the risk of default remained increased in those not assigned DOT (RR 1.99, 95%CI 1.03-3.85). In non-Thai TB patients, DOT was the only modifiable factor associated with default. Using DOT may help improve TB treatment outcomes in non-Thai TB patients.

Observation of Spin-Polarons in a strongly interacting Fermi liquid

NASA Astrophysics Data System (ADS)

Zwierlein, Martin

2009-03-01

We have observed spin-polarons in a highly imbalanced mixture of fermionic atoms using tomographic RF spectroscopy. Feshbach resonances allow to freely tune the interactions between the two spin states involved. A single spin down atom immersed in a Fermi sea of spin up atoms can do one of two things: For strong attraction, it can form a molecule with exactly one spin up partner, but for weaker interaction it will spread its attraction and surround itself with a collection of majority atoms. This spin down atom ``dressed'' with a spin up cloud constitutes the spin-polaron. We have observed a striking spectroscopic signature of this quasi-particle for various interaction strengths, a narrow peak in the spin down spectrum that emerges above a broad background. The narrow width signals a long lifetime of the spin-polaron, much longer than the collision rate with spin up atoms, as it must be for a proper quasi-particle. The peak position allows to directly measure the polaron energy. The broad pedestal at high energies reveals physics at short distances and is thus ``molecule-like'': It is exactly matched by the spin up spectra. The comparison with the area under the polaron peak allows to directly obtain the quasi-particle weight Z. We observe a smooth transition from polarons to molecules. At a critical interaction strength of 1/kFa = 0.7, the polaron peak vanishes and spin up and spin down spectra exactly match, signalling the formation of molecules. This is the same critical interaction strength found earlier to separate a normal Fermi mixture from a superfluid molecular Bose-Einstein condensate. The spin-polarons determine the low-temperature phase diagram of imbalanced Fermi mixtures. In principle, polarons can interact with each other and should, at low enough temperatures, form a superfluid of p-wave pairs. We will present a first indication for interactions between polarons.

Allowable carbon emissions lowered by multiple climate targets.

PubMed

Steinacher, Marco; Joos, Fortunat; Stocker, Thomas F

2013-07-11

Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity and carbon cycle feedbacks along with a large set of observational constraints. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions.

Direct Observation of Very Large Zero-Field Splitting in a Tetrahedral Ni(II)Se4 Coordination Complex.

PubMed

Jiang, Shang-Da; Maganas, Dimitrios; Levesanos, Nikolaos; Ferentinos, Eleftherios; Haas, Sabrina; Thirunavukkuarasu, Komalavalli; Krzystek, J; Dressel, Martin; Bogani, Lapo; Neese, Frank; Kyritsis, Panayotis

2015-10-14

The high-spin (S = 1) tetrahedral Ni(II) complex [Ni{(i)Pr2P(Se)NP(Se)(i)Pr2}2] was investigated by magnetometry, spectroscopic, and quantum chemical methods. Angle-resolved magnetometry studies revealed the orientation of the magnetization principal axes. The very large zero-field splitting (zfs), D = 45.40(2) cm(-1), E = 1.91(2) cm(-1), of the complex was accurately determined by far-infrared magnetic spectroscopy, directly observing transitions between the spin sublevels of the triplet ground state. These are the largest zfs values ever determined--directly--for a high-spin Ni(II) complex. Ab initio calculations further probed the electronic structure of the system, elucidating the factors controlling the sign and magnitude of D. The latter is dominated by spin-orbit coupling contributions of the Ni ions, whereas the corresponding effects of the Se atoms are remarkably smaller.

Direct observation of vast off-stoichiometric defects in single crystalline SnSe

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

Wu, Di; Wu, Lijun; He, Dongsheng

Single crystalline tin selenide (SnSe) recently emerged as a very promising thermoelectric material for waste heat harvesting and thermoelectric cooling, due to its record high figure of merit ZT in mediate temperature range. The most striking feature of SnSe lies in its extremely low lattice thermal conductivity as ascribed to the anisotropic and highly distorted Sn-Se bonds as well as the giant bond anharmonicity by previous studies, yet no theoretical models so far can give a quantitative explanation to such low a lattice thermal conductivity. Here, we presented direct observation of an astonishingly vast number of off-stoichiometric Sn vacancies andmore » Se interstitials, using sophisticated aberration corrected scanning transmission electron microscope; and credited the previously reported ultralow thermal conductivity of the SnSe single crystalline samples partly to their off-stoichiometric feature. In order to further validate the conclusion, we also synthesized stoichiometric SnSe single crystalline samples, and illustrated that the lattice thermal conductivity is deed much higher as compared with the off-stoichiometric single crystals. Finally, the scattering efficiency of individual point defect on heat-carrying phonons was then discussed in the state-of-art Debye-Callaway model.« less

Observation of direct infrared multiphoton pumping of the triplet manifold of biacetyl

NASA Astrophysics Data System (ADS)

Tsao, Jeffrey Y.; Black, Jerry G.; Yablonovitch, Eli; Burak, Itamar

1980-09-01

Direct collisionless multiphoton (MP) excitation of the triplet vibronic manifold of biacetyl is reported. Following a dye laser pulse which prepares some of the biacetyl molecules in the triplet metastable state, the system is irradiated by an intense 20 ns 9.6μ CO2 pulse. The CO2 radiation induces fast quenching of the phosphorescence emission from the 3Au excited molecules. It also induces an emission signal in the fluorescence spectral region of biacetyl. This signal is related to an inverse electronic relaxation (IER) from excited triplet vibronic levels into isoenergetic singlet 1Au vibronic levels. Analysis of the induced luminescence signals provides information on the collisionless MP prompted vibrational distribution. Excitation with 10.6μ CO2 pulses leads to the simultaneous MP pumping of both the ground and triplet manifolds. The generation of blue emission signals in this experiment bears a close resemblance to recent observations of prompt visible emission due to MP pumping of ground state molecules. General expressions for the emission intensities are derived with special emphasis on the specific features of MP vibrational distributions. The detectability of MP induced emission signals is discussed.

Direct observation of vast off-stoichiometric defects in single crystalline SnSe

DOE PAGES

Wu, Di; Wu, Lijun; He, Dongsheng; ...

2017-04-06

Single crystalline tin selenide (SnSe) recently emerged as a very promising thermoelectric material for waste heat harvesting and thermoelectric cooling, due to its record high figure of merit ZT in mediate temperature range. The most striking feature of SnSe lies in its extremely low lattice thermal conductivity as ascribed to the anisotropic and highly distorted Sn-Se bonds as well as the giant bond anharmonicity by previous studies, yet no theoretical models so far can give a quantitative explanation to such low a lattice thermal conductivity. Here, we presented direct observation of an astonishingly vast number of off-stoichiometric Sn vacancies andmore » Se interstitials, using sophisticated aberration corrected scanning transmission electron microscope; and credited the previously reported ultralow thermal conductivity of the SnSe single crystalline samples partly to their off-stoichiometric feature. In order to further validate the conclusion, we also synthesized stoichiometric SnSe single crystalline samples, and illustrated that the lattice thermal conductivity is deed much higher as compared with the off-stoichiometric single crystals. Finally, the scattering efficiency of individual point defect on heat-carrying phonons was then discussed in the state-of-art Debye-Callaway model.« less

Dissecting the mechanism of martensitic transformation via atomic-scale observations.

PubMed

Yang, Xu-Sheng; Sun, Sheng; Wu, Xiao-Lei; Ma, Evan; Zhang, Tong-Yi

2014-08-21

Martensitic transformation plays a pivotal role in the microstructural evolution and plasticity of many engineering materials. However, so far the underlying atomic processes that accomplish the displacive transformation have been obscured by the difficulty in directly observing key microstructural signatures on atomic scale. To resolve this long-standing problem, here we examine an AISI 304 austenitic stainless steel that has a strain/microstructure-gradient induced by surface mechanical attrition, which allowed us to capture in one sample all the key interphase regions generated during the γ(fcc) → ε(hcp) → α'(bcc) transition, a prototypical case of deformation induced martensitic transformation (DIMT). High-resolution transmission electron microscopy (HRTEM) observations confirm the crucial role of partial dislocations, and reveal tell-tale features including the lattice rotation of the α' martensite inclusion, the transition lattices at the ε/α' interfaces that cater the shears, and the excess reverse shear-shuffling induced γ necks in the ε martensite plates. These direct observations verify for the first time the 50-year-old Bogers-Burgers-Olson-Cohen (BBOC) model, and enrich our understanding of DIMT mechanisms. Our findings have implications for improved microstructural control in metals and alloys.

Dissecting the Mechanism of Martensitic Transformation via Atomic-Scale Observations

PubMed Central

Yang, Xu-Sheng; Sun, Sheng; Wu, Xiao-Lei; Ma, Evan; Zhang, Tong-Yi

2014-01-01

Martensitic transformation plays a pivotal role in the microstructural evolution and plasticity of many engineering materials. However, so far the underlying atomic processes that accomplish the displacive transformation have been obscured by the difficulty in directly observing key microstructural signatures on atomic scale. To resolve this long-standing problem, here we examine an AISI 304 austenitic stainless steel that has a strain/microstructure-gradient induced by surface mechanical attrition, which allowed us to capture in one sample all the key interphase regions generated during the γ(fcc) → ε(hcp) → α′(bcc) transition, a prototypical case of deformation induced martensitic transformation (DIMT). High-resolution transmission electron microscopy (HRTEM) observations confirm the crucial role of partial dislocations, and reveal tell-tale features including the lattice rotation of the α′ martensite inclusion, the transition lattices at the ε/α′ interfaces that cater the shears, and the excess reverse shear-shuffling induced γ necks in the ε martensite plates. These direct observations verify for the first time the 50-year-old Bogers-Burgers-Olson-Cohen (BBOC) model, and enrich our understanding of DIMT mechanisms. Our findings have implications for improved microstructural control in metals and alloys. PMID:25142283

Direct observation of small cluster mobility and ripening. [during annealing of metal films on amorphous substrates

NASA Technical Reports Server (NTRS)

Heinemann, K.; Poppa, H.

1975-01-01

Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single crystalline thin graphite substrates were studied by in-situ transmission electron microscopy (TEM) under controlled environmental conditions (residual gas pressure of 10 to the minus 9th power torr) in the temperature range from 25 to 450 C. Sputter cleaning of the substrate surface, metal deposition, and annealing were monitored by TEM observation. Pseudostereographic presentation of micrographs in different annealing stages, the observation of the annealing behavior at cast shadow edges, and measurements with an electronic image analyzing system were employed to aid the visual perception and the analysis of changes in deposit structure recorded during annealing. Slow Ostwald ripening was found to occur in the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility.

Comparison of rumination activity measured using rumination collars against direct visual observations and analysis of video recordings of dairy cows in commercial farm environments.

PubMed

Ambriz-Vilchis, V; Jessop, N S; Fawcett, R H; Shaw, D J; Macrae, A I

2015-03-01

Automated systems for monitoring the behavior of cows have become increasingly important for management routines and for monitoring health and welfare. In the past few decades, various devices that record rumination have been developed. The aim of the present study was to compare rumination activity measured with a commercially available rumination collar (RC) against that obtained by direct visual observations and analysis of video recordings in commercial dairy cows. Rumination time from video recordings was recorded by a trained observer. To assess observer reliability, data were recorded twice, and the duration of recorded behaviors was very similar and highly correlated between these 2 measurements (mean=39±4 and 38±4 min/2 h). Measurements of rumination time obtained with RC when compared with analysis of video recordings and direct observations were variable: RC output was significantly positively related to observed rumination activity when dealing with animals housed indoors (trial 1 video recordings: slope=1.02, 95% CI=0.92-1.12), and the limits of agreement method (LoA) showed differences (in min per 2-h block) to be within -26.92 lower and 24.27 upper limits. Trial 1 direct observations: slope=1.08, 95% CI=0.62-1.55, and the LoA showed differences to be within -28.54 lower and 21.98 upper limits. Trial 2: slope=0.93, 95% CI=0.64-1.23, and the LoA showed differences to be within -32.56 lower and 19.84 upper limits. However, the results were poor when cows were outside grazing grass (trial 3: slope=0.57, 95% CI=0.13-1.02, and the LoA showed differences to be within wider limits -51.16 lower and 53.02 upper). Our results suggest that RC can determine rumination activity and are an alternative to visual observations when animals are housed indoors. However, they are not an alternative to direct observations with grazing animals on pasture and its use is not advisable until further research and validation are carried out. Copyright © 2015 American Dairy

Biannual birth pulses allow filoviruses to persist in bat populations

PubMed Central

Hayman, David T. S.

2015-01-01

Filoviruses Ebolavirus (EBOV) and Marburgvirus (MARV) cause haemorrhagic fevers with high mortality rates, posing significant threats to public health. To understand transmission into human populations, filovirus dynamics within reservoir host populations must be understood. Studies have directly linked filoviruses to bats, but the mechanisms allowing viral persistence within bat populations are poorly understood. Theory suggests seasonal birthing may decrease the probability of pathogen persistence within populations, but data suggest MARV may persist within colonies of seasonally breeding Egyptian fruit bats, Rousettus aegyptiacus. I synthesize available filovirus and bat data in a stochastic compartmental model to explore fundamental questions relating to filovirus ecology: can filoviruses persist within isolated bat colonies; do critical community sizes exist; and how do host–pathogen relationships affect spillover transmission potential? Synchronous annual breeding and shorter incubation periods did not allow filovirus persistence, whereas bi-annual breeding and longer incubation periods, such as reported for Egyptian fruit bats and EBOV in experimental studies, allowed persistence in colony sizes often found in nature. Serological data support the findings, with bats from species with two annual birth pulses more likely to be seropositive (odds ratio (OR) 4.4, 95% confidence interval (CI) 2.5–8.7) than those with one, suggesting that biannual birthing is necessary for filovirus persistence. PMID:25673678

Unimolecular Thermal Decomposition of Phenol and d5-Phenol: Direct Observation of Cyclopentadiene Formation via Cyclohexadienone

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

Scheer, A. M.; Mukarakate, C.; Robichaud, D. J.

The pyrolyses of phenol and d{sub 5}-phenol (C{sub 6}H{sub 5}OH and C{sub 6}D{sub 5}OH) have been studied using a high temperature, microtubular ({mu}tubular) SiC reactor. Product detection is via both photon ionization (10.487 eV) time-of-flight mass spectrometry and matrix isolation infrared spectroscopy. Gas exiting the heated reactor (375 K-1575 K) is subject to a free expansion after a residence time in the {mu}tubular reactor of approximately 50-100 {micro}s. The expansion from the reactor into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. We find that the initial decomposition steps at themore » onset of phenol pyrolysis are enol/keto tautomerization to form cyclohexadienone followed by decarbonylation to produce cyclopentadiene; C{sub 6}H{sub 5}OH {yields} c-C{sub 6}H{sub 6} = O {yields} c-C{sub 5}H{sub 6} + CO. The cyclopentadiene loses a H atom to generate the cyclopentadienyl radical which further decomposes to acetylene and propargyl radical; c-C{sub 5}H{sub 6} {yields} c-C{sub 5}H{sub 5} + H {yields} HC {triple_bond} CH + HCCCH{sub 2}. At higher temperatures, hydrogen loss from the PhO-H group to form phenoxy radical followed by CO ejection to generate the cyclopentadienyl radical likely contributes to the product distribution; C{sub 6}H{sub 5}O-H {yields} C{sub 6}H{sub 5}O + H {yields} c-C{sub 5}H{sub 5} + CO. The direct decarbonylation reaction remains an important channel in the thermal decomposition mechanisms of the dihydroxybenzenes. Both catechol (o-HO-C{sub 6}H{sub 4}-OH) and hydroquinone (p-HO-C{sub 6}H{sub 4}-OH) are shown to undergo decarbonylation at the onset of pyrolysis to form hydroxycyclopentadiene. In the case of catechol, we observe that water loss is also an important decomposition channel at the onset of pyrolysis.« less

Directly observed daily mouth care provided to care home residents in one area of Kent, UK.

PubMed

Zander, A; Boniface, D

2017-03-01

To gather accurate data on the daily mouth care provided in care homes including tooth brushing, oral health assessment, and recording of care provided. Direct observation and notes review. Both nursing and 'regular' care homes. 365 Residents living in 16 care homes and their carers underwent observation, notes review or data collection in some form. Provision of mouth morning care. Of 161 residents observed, most (93, 58%) did not have their teeth/dentures brushed. If performed, brushing was often carried out by the resident themselves (36 cases, 53%), rather than by a carer (32 cases, 44%). Carers used a toothbrush to clean inside a resident's mouth in just 7 cases (4.3% of all personal care routines observed). Smaller care homes were no more likely to brush residents teeth than larger care homes, and nursing homes were no more likely to brush teeth than other care homes. Of the 309 sets of notes available for review, 41 (13%) contained a dedicated oral health needs assessment, and 109 (35%) contained a daily oral care chart in some form. Mouth care was often recorded inaccurately (15% of cases). This is the first observational study in the UK to assess oral care actually provided to residents by carers in care homes. The findings reveal a substantially different picture of daily mouth care than was previously understood and suggest that many of the nation's care home residents may not be receiving adequate, or any, oral health care. Copyright© 2017 Dennis Barber Ltd

Predictability of action sub-steps modulates motor system activation during the observation of goal-directed actions.

PubMed

Braukmann, Ricarda; Bekkering, Harold; Hidding, Margreeth; Poljac, Edita; Buitelaar, Jan K; Hunnius, Sabine

2017-08-01

Action perception and execution are linked in the human motor system, and researchers have proposed that this action-observation matching system underlies our ability to predict observed behavior. If the motor system is indeed involved in the generation of action predictions, activation should be modulated by the degree of predictability of an observed action. This study used EEG and eye-tracking to investigate whether and how predictability of an observed action modulates motor system activation as well as behavioral predictions in the form of anticipatory eye-movements. Participants were presented with object-directed actions (e.g., making a cup of tea) consisting of three action steps which increased in their predictability. While the goal of the first step was ambiguous (e.g., when making tea, one can first grab the teabag or the cup), the goals of the following steps became predictable over the course of the action. Motor system activation was assessed by measuring attenuation of sensorimotor mu- and beta-oscillations. We found that mu- and beta-power were attenuated during observation, indicating general activation of the motor system. Importantly, predictive motor system activation, indexed by beta-band attenuation, increased for each action step, showing strongest activation prior to the final (i.e. most predictable) step. Sensorimotor activity was related to participants' predictive eye-movements which also showed a modulation by action step. Our results demonstrate that motor system activity and behavioral predictions become stronger for more predictable action steps. The functional roles of sensorimotor oscillations in predicting other's actions are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

IRIS, Hinode, SDO, and RHESSI Observations of a White Light Flare Produced Directly by Nonthermal Electrons

NASA Astrophysics Data System (ADS)

Lee, Kyoung-Sun; Imada, Shinsuke; Watanabe, Kyoko; Bamba, Yumi; Brooks, David H.

2017-02-01

An X1.6 flare occurred in active region AR 12192 on 2014 October 22 at 14:02 UT and was observed by Hinode, IRIS, SDO, and RHESSI. We analyze a bright kernel that produces a white light (WL) flare with continuum enhancement and a hard X-ray (HXR) peak. Taking advantage of the spectroscopic observations of IRIS and Hinode/EIS, we measure the temporal variation of the plasma properties in the bright kernel in the chromosphere and corona. We find that explosive evaporation was observed when the WL emission occurred, even though the intensity enhancement in hotter lines is quite weak. The temporal correlation of the WL emission, HXR peak, and evaporation flows indicates that the WL emission was produced by accelerated electrons. To understand the WL emission process, we calculated the energy flux deposited by non-thermal electrons (observed by RHESSI) and compared it to the dissipated energy estimated from a chromospheric line (Mg II triplet) observed by IRIS. The deposited energy flux from the non-thermal electrons is about (3-7.7) × 1010 erg cm-2 s-1 for a given low-energy cutoff of 30-40 keV, assuming the thick-target model. The energy flux estimated from the changes in temperature in the chromosphere measured using the Mg II subordinate line is about (4.6-6.7) × 109 erg cm-2 s-1: ˜6%-22% of the deposited energy. This comparison of estimated energy fluxes implies that the continuum enhancement was directly produced by the non-thermal electrons.

Community-based treatment of advanced HIV disease: introducing DOT-HAART (directly observed therapy with highly active antiretroviral therapy).

PubMed Central

Farmer, P.; Léandre, F.; Mukherjee, J.; Gupta, R.; Tarter, L.; Kim, J. Y.

2001-01-01

In 2000, acquired immunodeficiency syndrome (AIDS) overtook tuberculosis (TB) as the world's leading infectious cause of adult deaths. In affluent countries, however, AIDS mortality has dropped sharply, largely because of the use of highly active antiretroviral therapy (HAART). Antiretroviral agents are not yet considered essential medications by international public health experts and are not widely used in the poor countries where human immunodeficiency virus (HIV) takes its greatest toll. Arguments against the use of HAART have mainly been based on the high cost of medications and the lack of the infrastructure necessary for using them wisely. We re- examine these arguments in the setting of rising AIDS mortality in developing countries and falling drug prices, and describe a small community-based treatment programme based on lessons gained in TB control. With the collaboration of Haitian community health workers experienced in the delivery of home-based and directly observed treatment for TB, an AIDS-prevention project was expanded to deliver HAART to a subset of HIV patients deemed most likely to benefit. The inclusion criteria and preliminary results are presented. We conclude that directly observed therapy (DOT) with HAART, "DOT-HAART", can be delivered effectively in poor settings if there is an uninterrupted supply of high-quality drugs. PMID:11799447

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Ku??tzing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L-1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method. ?? Springer 2005.

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Kützing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L−1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method.

Direct estimation and correction of bias from temporally variable non-stationary noise in a channelized Hotelling model observer.

PubMed

Fetterly, Kenneth A; Favazza, Christopher P

2016-08-07

Channelized Hotelling model observer (CHO) methods were developed to assess performance of an x-ray angiography system. The analytical methods included correction for known bias error due to finite sampling. Detectability indices ([Formula: see text]) corresponding to disk-shaped objects with diameters in the range 0.5-4 mm were calculated. Application of the CHO for variable detector target dose (DTD) in the range 6-240 nGy frame(-1) resulted in [Formula: see text] estimates which were as much as 2.9×  greater than expected of a quantum limited system. Over-estimation of [Formula: see text] was presumed to be a result of bias error due to temporally variable non-stationary noise. Statistical theory which allows for independent contributions of 'signal' from a test object (o) and temporally variable non-stationary noise (ns) was developed. The theory demonstrates that the biased [Formula: see text] is the sum of the detectability indices associated with the test object [Formula: see text] and non-stationary noise ([Formula: see text]). Given the nature of the imaging system and the experimental methods, [Formula: see text] cannot be directly determined independent of [Formula: see text]. However, methods to estimate [Formula: see text] independent of [Formula: see text] were developed. In accordance with the theory, [Formula: see text] was subtracted from experimental estimates of [Formula: see text], providing an unbiased estimate of [Formula: see text]. Estimates of [Formula: see text] exhibited trends consistent with expectations of an angiography system that is quantum limited for high DTD and compromised by detector electronic readout noise for low DTD conditions. Results suggest that these methods provide [Formula: see text] estimates which are accurate and precise for [Formula: see text]. Further, results demonstrated that the source of bias was detector electronic readout noise. In summary, this work presents theory and methods to test for the

Clean Air Markets - Allowances Query Wizard

EPA Pesticide Factsheets

The Allowances Query Wizard is part of a suite of Clean Air Markets-related tools that are accessible at http://camddataandmaps.epa.gov/gdm/index.cfm. The Allowances module allows the user to view allowance data associated with EPA's emissions trading programs. Allowance data can be specified and organized using the Allowance Query Wizard to find allowances information associated with specific accounts, companies, transactions, programs, facilities, representatives, allowance type, or by date. Quick Reports and Prepackaged Datasets are also available for data that are commonly requested.EPA's Clean Air Markets Division (CAMD) includes several market-based regulatory programs designed to improve air quality and ecosystems. The most well-known of these programs are EPA's Acid Rain Program and the NOx Programs, which reduce emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx)-compounds that adversely affect air quality, the environment, and public health. CAMD also plays an integral role in the development and implementation of the Clean Air Interstate Rule (CAIR).

Long-duration planar direct-drive hydrodynamics experiments on the NIF

NASA Astrophysics Data System (ADS)

Casner, A.; Mailliet, C.; Khan, S. F.; Martinez, D.; Izumi, N.; Kalantar, D.; Di Nicola, P.; Di Nicola, J. M.; Le Bel, E.; Igumenshchev, I.; Tikhonchuk, V. T.; Remington, B. A.; Masse, L.; Smalyuk, V. A.

2018-01-01

The advent of high-power lasers facilities such as the National Ignition Facility (NIF) and the laser megajoule provide unique platforms to study the physics of turbulent mixing flows in high energy density plasmas. We report here on the commissioning of a novel planar direct-drive platform on the NIF, which allows the acceleration of targets during 30 ns. Planar plastic samples were directly irradiated by 300-450 kJ of UV laser light (351 nm) and a very good planarity of the laser drive is demonstrated. No detrimental effect of imprint is observed in the case of these thick plastic targets (300 μm), which is beneficial for future academic experiments requesting similar irradiation conditions. The long-duration direct-drive (DD) platform is thereafter harnessed to study the ablative Rayleigh-Taylor instability (RTI) in DD. The growth of two-dimensional pre-imposed perturbations is quantified through time-resolved face-on x-ray radiography and used as a benchmark for radiative hydrocode simulations. The ablative RTI is then quantified in its highly nonlinear stage starting from intentionally large 3D imprinted broadband modulations. Two generations of bubble mergers is observed for the first time in DD, as a result of the unprecedented long laser acceleration.

45 CFR 1630.3 - Standards governing allowability of costs under Corporation grants or contracts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Standards governing allowability of costs under Corporation grants or contracts. 1630.3 Section 1630.3 Public Welfare Regulations Relating to Public Welfare... accordance with the relative benefits received. Costs may be allocated to Corporation funds either as direct...

26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

Code of Federal Regulations, 2014 CFR

2014-04-01

... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such as...)(iv) of this paragraph: (i) Losses for damages to or destruction of property as a result of drought...

26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such as...)(iv) of this paragraph: (i) Losses for damages to or destruction of property as a result of drought...

26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

Code of Federal Regulations, 2012 CFR

2012-04-01

... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such as...)(iv) of this paragraph: (i) Losses for damages to or destruction of property as a result of drought...

26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

Code of Federal Regulations, 2013 CFR

2013-04-01

... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such as...)(iv) of this paragraph: (i) Losses for damages to or destruction of property as a result of drought...

Simulation of Channel Segregation During Directional Solidification of In—75 wt pct Ga. Qualitative Comparison with In Situ Observations

NASA Astrophysics Data System (ADS)

Saad, Ali; Gandin, Charles-André; Bellet, Michel; Shevchenko, Natalia; Eckert, Sven

2015-11-01

Freckles are common defects in industrial casting. They result from thermosolutal convection due to buoyancy forces generated from density variations in the liquid. The present paper proposes a numerical analysis for the formation of channel segregation using the three-dimensional (3D) cellular automaton (CA)—finite element (FE) model. The model integrates kinetics laws for the nucleation and growth of a microstructure with the solution of the conservation equations for the casting, while introducing an intermediate modeling scale for a direct representation of the envelope of the dendritic grains. Directional solidification of a cuboid cell is studied. Its geometry, the alloy chosen as well as the process parameters are inspired from experimental observations recently reported in the literature. Snapshots of the convective pattern, the solute distribution, and the morphology of the growth front are qualitatively compared. Similitudes are found when considering the coupled 3D CAFE simulations. Limitations of the model to reach direct simulation of the experiments are discussed.

Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 1018 eV.

PubMed

2017-09-22

Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Using 3 × 10 4 cosmic rays with energies above 8 × 10 18 electron volts, recorded with the Pierre Auger Observatory from a total exposure of 76,800 km 2 sr year, we determined the existence of anisotropy in arrival directions. The anisotropy, detected at more than a 5.2σ level of significance, can be described by a dipole with an amplitude of [Formula: see text] percent toward right ascension α d = 100 ± 10 degrees and declination δ d = [Formula: see text] degrees . That direction indicates an extragalactic origin for these ultrahigh-energy particles. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

49 CFR 266.11 - Allowable costs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TRANSPORTATION ACT § 266.11 Allowable costs. Allowable costs include only the following costs which are properly allocable to the work performed: Planning and program operation costs which are allowed under Federal... 49 Transportation 4 2010-10-01 2010-10-01 false Allowable costs. 266.11 Section 266.11...

Direct-heating solar-collector dump valve

NASA Technical Reports Server (NTRS)

Howikman, T. C.

1977-01-01

Five-port ganged valve isolates collector from primary load system pressure and drains collectors, allowing use of direct heating with all its advantages. Valve is opened and closed by same switch that controls pump or by temperature sensor set at O C, while providing direct dump option.

Direct observation of nanoparticle-cancer cell nucleus interactions.

PubMed

Dam, Duncan Hieu M; Lee, Jung Heon; Sisco, Patrick N; Co, Dick T; Zhang, Ming; Wasielewski, Michael R; Odom, Teri W

2012-04-24

We report the direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported to the nucleus and induced major changes to the nuclear phenotype via nuclear envelope invaginations near the site of the construct. The number of local deformations could be increased by ultrafast, light-triggered release of the aptamers from the surface of the gold nanostars. Cancer cells with more nuclear envelope folding showed increased caspase 3 and 7 activity (apoptosis) as well as decreased cell viability. This newly revealed correlation between drug-induced changes in nuclear phenotype and increased therapeutic efficacy could provide new insight for nuclear-targeted cancer therapy.

46 CFR 154.421 - Allowable stress.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

46 CFR 154.421 - Allowable stress.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

46 CFR 154.421 - Allowable stress.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

46 CFR 154.421 - Allowable stress.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

46 CFR 154.421 - Allowable stress.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...

20 CFR 617.46 - Travel allowance.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Travel allowance. 617.46 Section 617.46... FOR WORKERS UNDER THE TRADE ACT OF 1974 Relocation Allowances § 617.46 Travel allowance. (a) Computation. The amount of travel allowance (including lodging and meals) payable under § 617.45(a)(1) shall...

Observation of ultra high energy cosmic rays from space: Status and perspectives

NASA Astrophysics Data System (ADS)

Casolino, M.; Klimov, P.; Piotrowski, L.

2017-12-01

The study of ultra high energy cosmic rays (UHECRs) offers unique possibilities to probe the energies currently inaccessible by man-made accelerators. Recent years have shed light on several characteristics of these particles, but—due to their extremely low flux—their origin, nature, and acceleration mechanisms are still unclear. Space-based observations have the potential for an increase in statistics, up to several orders of magnitude, and would be able to cover the whole sky, allowing for a direct comparison of spectra and direction of arrival. A detector with the exposure of a few times that of the Pierre Auger Observatory would be able to clarify the observed differences between the northern and southern skies, confirm the existence of TA hot spot, and measure multipolar anisotropies with high precision. A number of novel technologies—from optics to sensors, front-end and read-out electronics—have been developed over the years to achieve this goal. In this paper we describe the progress and results obtained so far and discuss the perspectives of UHECR physics observation from space.

76 FR 32340 - Federal Travel Regulation; Temporary Duty (TDY) Travel Allowances (Taxes); Relocation Allowances...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-06

..., as taxable income. When you receive taxable benefits, you must pay income tax on the amount or value... Allowances (Taxes); Relocation Allowances (Taxes) AGENCY: Office of Governmentwide Policy (OGP), General...) concerning calculation of reimbursements for taxes on relocation expenses. In addition, this proposed rule...

CHIMERA: Top-down model for hierarchical, overlapping and directed cluster structures in directed and weighted complex networks

NASA Astrophysics Data System (ADS)

Franke, R.

2016-11-01

In many networks discovered in biology, medicine, neuroscience and other disciplines special properties like a certain degree distribution and hierarchical cluster structure (also called communities) can be observed as general organizing principles. Detecting the cluster structure of an unknown network promises to identify functional subdivisions, hierarchy and interactions on a mesoscale. It is not trivial choosing an appropriate detection algorithm because there are multiple network, cluster and algorithmic properties to be considered. Edges can be weighted and/or directed, clusters overlap or build a hierarchy in several ways. Algorithms differ not only in runtime, memory requirements but also in allowed network and cluster properties. They are based on a specific definition of what a cluster is, too. On the one hand, a comprehensive network creation model is needed to build a large variety of benchmark networks with different reasonable structures to compare algorithms. On the other hand, if a cluster structure is already known, it is desirable to separate effects of this structure from other network properties. This can be done with null model networks that mimic an observed cluster structure to improve statistics on other network features. A third important application is the general study of properties in networks with different cluster structures, possibly evolving over time. Currently there are good benchmark and creation models available. But what is left is a precise sandbox model to build hierarchical, overlapping and directed clusters for undirected or directed, binary or weighted complex random networks on basis of a sophisticated blueprint. This gap shall be closed by the model CHIMERA (Cluster Hierarchy Interconnection Model for Evaluation, Research and Analysis) which will be introduced and described here for the first time.

Anatomic observation of the running space of the suprascapular nerve at the suprascapular notch in the same direction as the nerve.

PubMed

Tasaki, Atsushi; Nimura, Akimoto; Mochizuki, Tomoyuki; Yamaguchi, Kumiko; Kato, Ryuichi; Sugaya, Hiroyuki; Akita, Keiichi

2015-09-01

The configuration of suprascapular notch was previously analysed from the anteroposterior viewing. However, the approach direction of the suprascapular nerve (SSN) to the inlet of the suprascapular notch is consistently craniocaudal and mediolateral. We propose a new method to observe the suprascapular notch according to the running course of the SSN. We reviewed the anatomic characteristics of the suprascapular notch in relation to the nerve. In 30 formalin-fixed cadaveric shoulders, the morphology of the suprascapular notch and the attachments of the superior transverse scapular ligament (STSL) were examined from both the anteroposterior and the nerve approach direction. The dimensions of the opening of the SSN passage were measured. By observing from the nerve approach direction, the inlet of the suprascapular notch was recognized to be a space-bordered by the medial wall of the coracoid process, the deep fascia of subscapularis, and the STSL. The STSL formed a sheet-like structure, which ran parallel to the nerve and also to the deep fascia of subscapularis. The attachment of the ligament to the coracoid process was located at the posteromedial corner rather than the medial side. Based on the present study, the space between the STSL and deep fascia of the subscapularis formed the space for the nerve to run through. As a clinical implication, this new method to assess the suprascapular notch in the nerve approach direction might develop the imaging techniques for evaluation of SSN entrapment.

Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 10 18 eV

DOE PAGES

Aab, Alexander; et al.

2017-09-22

We report that cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Usingmore » $$3 \\times 10^4$$ cosmic rays above $$8 \\times 10^{18}$$ electron volts, recorded with the Pierre Auger Observatory from a total exposure of 76,800 square kilometers steradian year, we report an anisotropy in the arrival directions. The anisotropy, detected at more than the 5.2$$\\sigma$$ level of significance, can be described by a dipole with an amplitude of $$6.5_{-0.9}^{+1.3}$$% towards right ascension $$\\alpha_{d} = 100 \\pm 10$$ degrees and declination $$\\delta_{d} = -24_{-13}^{+12}$$ degrees. Lastly, that direction indicates an extragalactic origin for these ultra-high energy particles.« less

Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 10 18 eV

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

Aab, Alexander; et al.

We report that cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Usingmore » $$3 \\times 10^4$$ cosmic rays above $$8 \\times 10^{18}$$ electron volts, recorded with the Pierre Auger Observatory from a total exposure of 76,800 square kilometers steradian year, we report an anisotropy in the arrival directions. The anisotropy, detected at more than the 5.2$$\\sigma$$ level of significance, can be described by a dipole with an amplitude of $$6.5_{-0.9}^{+1.3}$$% towards right ascension $$\\alpha_{d} = 100 \\pm 10$$ degrees and declination $$\\delta_{d} = -24_{-13}^{+12}$$ degrees. Lastly, that direction indicates an extragalactic origin for these ultra-high energy particles.« less

Direct observation of isolated Damon-Eshbach and backward volume spin-wave packets in ferromagnetic microstripes

PubMed Central

Wessels, Philipp; Vogel, Andreas; Tödt, Jan-Niklas; Wieland, Marek; Meier, Guido; Drescher, Markus

2016-01-01

The analysis of isolated spin-wave packets is crucial for the understanding of magnetic transport phenomena and is particularly interesting for applications in spintronic and magnonic devices, where isolated spin-wave packets implement an information processing scheme with negligible residual heat loss. We have captured microscale magnetization dynamics of single spin-wave packets in metallic ferromagnets in space and time. Using an optically driven high-current picosecond pulse source in combination with time-resolved scanning Kerr microscopy probed by femtosecond laser pulses, we demonstrate phase-sensitive real-space observation of spin-wave packets in confined permalloy (Ni80Fe20) microstripes. Impulsive excitation permits extraction of the dynamical parameters, i.e. phase- and group velocities, frequencies and wave vectors. In addition to well-established Damon-Eshbach modes our study reveals waves with counterpropagating group- and phase-velocities. Such unusual spin-wave motion is expected for backward volume modes where the phase fronts approach the excitation volume rather than emerging out of it due to the negative slope of the dispersion relation. These modes are difficult to excite and observe directly but feature analogies to negative refractive index materials, thus enabling model studies of wave propagation inside metamaterials. PMID:26906113

Evaluation of the implementation of the directly observed treatment strategy for tuberculosis in a large city.

PubMed

Lavôr, Débora Cristina Brasil da Silva; Pinheiro, Jair Dos Santos; Gonçalves, Maria Jacirema Ferreira

2016-04-01

To assess the degree of implementation of the Directly Observed Treatment, Short-course - DOTS for tuberculosis (TB) in a large city. Assessment of the implementation of the logic model, whose new cases of infectious pulmonary TB were recruited from specialized clinics and followed-up in basic health units. The judgment matrix covering the five components of the DOTS strategy were used. The result of the logic model indicates DOTS was partially implemented. In external, organizational and implementation contexts, the DOTS strategy was partially implemented; and, the effectiveness was not implemented. The partial implementation of the DOTS strategy in the city of Manaus did not reflect in TB control compliance, leading to low effectiveness of the program. Avaliar o grau de implantação da estratégia de tratamento diretamente observado (Directly Observed Treatment, Short-course - DOTS) para tuberculose (TB) em um município de grande porte. Avaliação de implantação por meio de modelo lógico, cujos casos novos de TB pulmonar bacilífera foram recrutados em ambulatórios especializados e acompanhados nas unidades básicas de saúde. Utilizou-se matriz de julgamento que abrange os cinco componentes da estratégia DOTS. O resultado do modelo lógico indica DOTS implantada parcialmente. Nos contextos externo, organizacional e de implantação, a estratégia DOTS está implantada parcialmente; e, na efetividade não está implantada. A implantação parcial da estratégia DOTS, na cidade de Manaus, reflete na não conformidade do controle da TB, levando à baixa efetividade do programa.

Direct Observation of Energy Detrapping in LH1-RC Complex by Two-Dimensional Electronic Spectroscopy.

PubMed

Ma, Fei; Yu, Long-Jiang; Hendrikx, Ruud; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

2017-01-18

The purple bacterial core light harvesting antenna-reaction center (LH1-RC) complex is the simplest system able to achieve the entire primary function of photosynthesis. During the past decade, a variety of photosynthetic proteins were studied by a powerful technique, two-dimensional electronic spectroscopy (2DES). However, little attention has been paid to LH1-RC, although its reversible uphill energy transfer, trapping, and backward detrapping processes, represent a crucial step in the early photosynthetic reaction dynamics. Thus, in this work, we employed 2DES to study two LH1-RC complexes of Thermochromatium (Tch.) tepidum. By direct observation of detrapping, the complex reversible process was clearly identified and an overall scheme of the excitation evolution in LH1-RC was obtained.

Open-access and multi-directional electroosmotic flow chip for positioning heterotypic cells.

PubMed

Terao, Kyohei; Kitazawa, Yuko; Yokokawa, Ryuji; Okonogi, Atsuhito; Kotera, Hidetoshi

2011-04-21

We propose a novel method of cell positioning using electroosmotic flow (EOF) to analyze cell-cell interactions. The EOF chip has an open-to-air configuration, is equipped with four electrodes to induce multi-directional EOF, and allows access of tools for liquid handling and of physical probes for cell measurements. Evaluation of the flow within this chip indicated that it controlled hydrodynamic transport of cells, in terms of both speed and direction. We also evaluated cell viability after EOF application and determined appropriate conditions for cell positioning. Two cells were successively positioned in pocket-like microstructures, one in each micropocket, by controlling the EOF direction. As an experimental demonstration, we observed contact interactions between two individual cells through gap junction channels. The EOF chip should provide ways to elucidate various cell-cell interactions between heterotypic cells.

The Radial Speed - Expansion Speed Relation for Earth-Directed CMEs

NASA Astrophysics Data System (ADS)

Makela, P. A.; Gopalswamy, N.; Yashiro, S.

2013-12-01

The propagation speed of Earth-directed coronal mass ejections (CMEs) is an essential parameter needed in space weather forecasting. However, the true propagation speed of Earth-directed CMEs cannot be measured accurately from coronagraph images taken from Earth's view. In order to circumvent the inaccuracies of speed measurements due to the projection effects, empirical relations expressing the radial speed (Vrad) of the CME as a function of the CME expansion speed (Vexp) have been suggested. Vexp is defined as the apparent speed the CME is spreading in the coronagraph's field of view. During 2010-2012 STEREO spacecraft provided a side view of Earth-directed CMEs, allowing measurements of true CME speeds and widths. In a case study of the 2011 February 15 CME Gopalswamy et al. (2012) compared three Vrad-Vexp relations (flat cone, full or shallow ice cream cone - Gopalswamy et al., 2009) and found the closest match with the observations for the (full ice cream cone) relation Vrad = 1/2(1 + cot w)Vexp, where w is the half width of the CME. Using the STEREO/SECCHI and SOHO/LASCO observations during this opportune period, we expand this analysis to a larger set of Earth-directed CMEs. We compare the computed CME speed estimates with the measured true speeds and estimate the accuracy of the Vrad-Vexp relations. References: Gopalswamy, N. et al. (2009), The expansion and radial speeds of coronal mass ejections, Cent. Eur. Astrophys. Bull., 33, 115. Gopalswamy, N. et al. (2012), The relationship between the expansion speed and radial speed of CMEs confirmed using quadrature observations of the 2011 February 15 CME, Sun and Geosphere, 7(1), 7.

46 CFR 154.440 - Allowable stress.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may be...

46 CFR 154.440 - Allowable stress.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may be...

INTEGRAL Observations of GW170104

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

Savchenko, V.; Ferrigno, C.; Bozzo, E.

2017-09-10

We used data from the International Gamma-Ray Astrophysics Laboratory ( INTEGRAL ) to set upper limits on the γ -ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration. The unique omnidirectional viewing capability of the instruments on board INTEGRAL allowed us to examine the full 90% confidence level localization region of the LIGO trigger. Depending on the particular spectral model assumed and the specific position within this region, the upper limits inferred from the INTEGRAL observations range from F {sub γ} = 1.9 × 10{sup −7} erg cm{supmore » −2} to F {sub γ} = 10{sup −6} erg cm{sup −2} (75 keV–2 MeV energy range). This translates into a ratio between the prompt energy released in γ -rays along the direction to the observer and the gravitational-wave energy of E {sub γ} / E {sub GW} < 2.6 × 10{sup −5}. Using the INTEGRAL results, we cannot confirm the γ -ray proposed counterpart to GW170104 by the Astro—Rivelatore Gamma a Immagini Leggero (AGILE) team with the mini-Calorimeter (MCAL) instrument. The reported flux of the AGILE/MCAL event, E2, is not compatible with the INTEGRAL upper limits within most of the 90% LIGO localization region. There is only a relatively limited portion of the sky where the sensitivity of the INTEGRAL instruments was not optimal and the lowest-allowed fluence estimated for E2 would still be compatible with the INTEGRAL results. This region was also observed independently by Fermi /Gamma-ray Burst Monitor and AstroSAT, from which, as far as we are aware, there are no reports of any significant detection of a prompt high-energy event.« less

Concurrent Activation of Striatal Direct and Indirect Pathways During Action Initiation

PubMed Central

Cui, Guohong; Jun, Sang Beom; Jin, Xin; Pham, Michael D.

2014-01-01

Summary The basal ganglia are subcortical nuclei that control voluntary actions, and are affected by a number of debilitating neurological disorders1–4. The prevailing model of basal ganglia function proposes that two orthogonal projection circuits originating from distinct populations of spiny projection neurons (SPNs) in the striatum5,6 - the so-called direct and indirect pathways - have opposing effects on movement: while activity of direct-pathway SPNs purportedly facilitates movement, activity of indirect-pathway SPNs inhibits movement1,2. This model has been difficult to test due to the lack of methods to selectively measure the activity of direct- and indirect-pathway SPNs in freely moving animals. We developed a novel in-vivo method that allowed us to specifically measure direct- and indirect-pathway SPN activity using Cre-dependent viral expression of the genetically encoded calcium indicator (GECI) GCAMP3 in the dorsal striatum of D1-Cre (direct-pathway specific6,7) and A2A-Cre (indirect-pathway specific8,9) mice10. Using fiber optics and time-correlated single photon counting (TCSPC) in mice performing an operant task, we observed transient increases in neural activity in both direct- and indirect-pathway SPNs when animals initiated actions, but not when they were inactive. Concurrent activation of SPNs from both pathways in one hemisphere preceded the initiation of contraversive movements, and predicted the occurrence of specific movements within 500 ms. These observations challenge the classical view of basal ganglia function, and may have implications for understanding the origin of motor symptoms in basal ganglia disorders. PMID:23354054

Disk Dispersal: Theoretical Understanding and Observational Constraints

NASA Astrophysics Data System (ADS)

Gorti, U.; Liseau, R.; Sándor, Z.; Clarke, C.

2016-12-01

Protoplanetary disks dissipate rapidly after the central star forms, on time-scales comparable to those inferred for planet formation. In order to allow the formation of planets, disks must survive the dispersive effects of UV and X-ray photoevaporation for at least a few Myr. Viscous accretion depletes significant amounts of the mass in gas and solids, while photoevaporative flows driven by internal and external irradiation remove most of the gas. A reasonably large fraction of the mass in solids and some gas get incorporated into planets. Here, we review our current understanding of disk evolution and dispersal, and discuss how these might affect planet formation. We also discuss existing observational constraints on dispersal mechanisms and future directions.

Direct to consumer advertising in pharmaceutical markets.

PubMed

Brekke, Kurt R; Kuhn, Michael

2006-01-01

We study effects of direct-to-consumer advertising (DTCA) in the prescription drug market. There are two pharmaceutical firms providing horizontally differentiated (branded) drugs. Patients differ in their susceptibility to the drugs. If DTCA is allowed, this can be employed to induce (additional) patient visits. Physicians perfectly observe the patients' type (of illness), but rely on information to prescribe the correct drug. Drug information is conveyed by marketing (detailing), creating a captive and a selective segment of physicians. First, we show that detailing, DTCA and price (if not regulated) are complementary strategies for the firms. Thus, allowing DTCA induces more detailing and higher prices. Second, firms benefit from DTCA if detailing competition is not too fierce, which is true if investing in detailing is sufficiently costly. Otherwise, firms are better off with a ban on DTCA. Finally, DTCA tends to lower welfare if insurance is generous (low copayments) and/or price regulation is lenient. The desirability of DTCA also depends on whether or not the regulator is concerned with firms' profit.

Flexibility in the HCFC Allowance System

EPA Pesticide Factsheets

The rule that established the HCFC allowance system also created an allowance transfer mechanism to provide flexibility. This fact sheet highlights the flexibilities incorporated into the HCFC allowance system.

Caregiver talk to young Spanish-English bilinguals: Comparing direct observation and parent-report measures of dual-language exposure