From Unresolved Anger to Sadness: Identifying Physiological Correlates

ERIC Educational Resources Information Center

Rochman, Daniel; Diamond, Gary M.

2008-01-01

This study was designed to identify physiological correlates of unresolved anger and sadness, and the shift between these emotions, in a context similar to that of emotion-focused, experiential psychotherapy. Twenty-seven university students reporting unresolved anger toward an attachment figure were induced to experience and express unresolved…

Three-step interferometric method with blind phase shifts by use of interframe correlation between interferograms

NASA Astrophysics Data System (ADS)

Muravsky, Leonid I.; Kmet', Arkady B.; Stasyshyn, Ihor V.; Voronyak, Taras I.; Bobitski, Yaroslav V.

2018-06-01

A new three-step interferometric method with blind phase shifts to retrieve phase maps (PMs) of smooth and low-roughness engineering surfaces is proposed. Evaluating of two unknown phase shifts is fulfilled by using the interframe correlation between interferograms. The method consists of two stages. The first stage provides recording of three interferograms of a test object and their processing including calculation of unknown phase shifts, and retrieval of a coarse PM. The second stage implements firstly separation of high-frequency and low-frequency PMs and secondly producing of a fine PM consisting of areal surface roughness and waviness PMs. Extraction of the areal surface roughness and waviness PMs is fulfilled by using a linear low-pass filter. The computer simulation and experiments fulfilled to retrieve a gauge block surface area and its areal surface roughness and waviness have confirmed the reliability of the proposed three-step method.

Relationship between subjective fatigue, physical activity, and sleep indices in nurses working 16-hour night shifts in a rotating two-shift system

PubMed Central

Kagamiyama, Hiromi; Yano, Rika

2018-01-01

Objective: We clarified the relationship between the degree of subjective fatigue, sleep, and physical activity among nurses working 16-hour night shifts in a rotating two-shift system. Materials and Methods: We investigated 15 nurses who were surveyed regarding their individual attributes, physical activity level (consumed calories), hours of sleep, sleep efficiency, sleep onset latency, sleep diary, and subjective symptoms. Nurses wore a Fitbit One (Fitbit Inc., San Francisco, CA, USA) for 7 consecutive days to measure sleep and physical activity. Results: Results were analyzed for nine participants, excluding those who withdrew or had missing data. The years of nursing experience, nurses’ age, and the length of nocturnal awakening time of the high fatigue group were significantly longer than of the low fatigue group (p < .05). Years of nursing experience in the affiliated department of the high fatigue group was significantly shorter than of low fatigue group (p < .05). The number of nightshifts during the survey period was significantly higher in the high fatigue group than in the low fatigue group. Fatigue after work and body mass index (r = 0.46, p < .001), consumed calories (r = 0.30, p < .05), bedtime (r = –0.36, p < .05), and hours of sleep (r = –0.37, p < .01) were significantly correlated; however, the sleep indices were not correlated. Conclusion: We clarified that the degree of fatigue in nurses working 16-hour night shifts in a rotating two-shift system was related to individual factors, such as age, years of nursing experience, years of nursing experience in the affiliated department, number of nightshifts, and length of nocturnal awakening time. Nurses with greater fatigue had significant differences in their bedtime on days off and work days, which suggests that sleep rhythm may also affect fatigue.

Context effects on tempo and pleasantness judgments for Beatles songs.

PubMed

Rashotte, Matthew A; Wedell, Douglas H

2012-04-01

Context effects on tempo and pleasantness judgments of different tempos were demonstrated in three experiments using Beatles songs. In Experiments 1 and 2, we explored how listening to versions of the same song that were played at different tempos affected tempo and pleasantness ratings. In both experiments, contrast effects were found on judgments of tempo, with target tempos rated faster when context tempos were slow than when they were fast. In both experiments, we also showed that the peak of the pleasantness rating function shifted toward the values of the context tempos, reflecting disordinal context effects on pleasantness relationships. Familiarity with the songs did not moderate these effects, and shifts in tempo ratings did not correlate with shifts in most pleasant target tempos when context was manipulated within subjects. In Experiment 3, we examined how manipulations of context tempos for one song affected judgments of the same song as compared with judgments of other more or less similar songs. For tempo ratings, contrast effects transferred to ratings of a similar song, but for pleasantness ratings, assimilative shifts of ideals were found only for the same song and not for similar songs. This pattern of results was supportive of independent bases for the two context effects.

The ALICE Glance Shift Accounting Management System (SAMS)

NASA Astrophysics Data System (ADS)

Martins Silva, H.; Abreu Da Silva, I.; Ronchetti, F.; Telesca, A.; Maidantchik, C.

2015-12-01

ALICE (A Large Ion Collider Experiment) is an experiment at the CERN LHC (Large Hadron Collider) studying the physics of strongly interacting matter and the quark-gluon plasma. The experiment operation requires a 24 hours a day and 7 days a week shift crew at the experimental site, composed by the ALICE collaboration members. Shift duties are calculated for each institute according to their correlated members. In order to ensure the full coverage of the experiment operation as well as its good quality, the ALICE Shift Accounting Management System (SAMS) is used to manage the shift bookings as well as the needed training. ALICE SAMS is the result of a joint effort between the Federal University of Rio de Janeiro (UFRJ) and the ALICE Collaboration. The Glance technology, developed by the UFRJ and the ATLAS experiment, sits at the basis of the system as an intermediate layer isolating the particularities of the databases. In this paper, we describe the ALICE SAMS development process and functionalities. The database has been modelled according to the collaboration needs and is fully integrated with the ALICE Collaboration repository to access members information and respectively roles and activities. Run, period and training coordinators can manage their subsystem operation and ensure an efficient personnel management. Members of the ALICE collaboration can book shifts and on-call according to pre-defined rights. ALICE SAMS features a user profile containing all the statistics and user contact information as well as the Institutes profile. Both the user and institute profiles are public (within the scope of the collaboration) and show the credit balance in real time. A shift calendar allows the Run Coordinator to plan data taking periods in terms of which subsystems shifts are enabled or disabled and on-call responsible people and slots. An overview display presents the shift crew present in the control room and allows the Run Coordination team to confirm the presence of both regular and trainees shift personnel, necessary for credit accounting.

Effects of asynchrony and ear of presentation on the pitch of mistuned partials in harmonic and frequency-shifted complex tones.

PubMed

Brunstrom, J M; Roberts, B

2001-07-01

When a partial of a periodic complex is mistuned, its change in pitch is greater than expected. Two experiments examined whether these partial-pitch shifts are related to the computation of global pitch. In experiment 1, stimuli were either harmonic or frequency-shifted (25% of F0) complexes. One partial was mistuned by +/- 4% and played with leading and lagging portions of 500 ms each, relative to the other components (1 s), in both monaural and dichotic contexts. Subjects indicated whether the mistuned partial was higher or lower in pitch when concurrent with the other components. Responses were positively correlated with the direction of mistuning in all conditions. In experiment 2, stimuli from each condition were compared with synchronous equivalents. Subjects matched a pure tone to the pitch of the mistuned partial (component 4). The results showed that partial-pitch shifts are not reduced in size by asynchrony. Similar asynchronies are known to produce a near-exclusion of a mistuned partial from the global-pitch computation. This mismatch indicates that global and partial pitch are derived from different processes. The similarity of the partial-pitch shifts observed for harmonic and frequency-shifted stimuli suggests that they arise from a grouping mechanism that is sensitive to spectral regularity.

Employing NMR Spectroscopy To Evaluate Transmission of Electronic Effects in 4-Substituted Chalcones

NASA Astrophysics Data System (ADS)

Wachter-Jurcsak, Nanette; Zamani, Hossein

1999-05-01

Described is an organic synthesis experiment that demonstrates the electronic transmission by substituents. The effect of substitution at the para-position of the styryl ring of 1,3-diphenyl-2-propenones (chalcones) by typical electron-donating or -accepting groups can be observed by proton and carbon-13 NMR spectroscopy. A linear correlation is observed when the differences in chemical shift measurements for H are plotted against the corresponding Hammett substituent constant values. Good correlation between carbon-13 chemical shifts of the alpha carbon are also observed. The syntheses of the 4-substituted chalcones is presented as well as a brief discussion of the theory.

A complete 1H and 13C NMR data assignment for the diterpene methyl (-)-zanzibarate by 2D spectroscopy and NOE experiments.

PubMed

Imamura, P M; Miranda, P C M L; Giacomini, R A

2004-06-01

The 1H and 13C NMR spectra of methyl (-)-zanzibarate (1), an ent-labdanic diterpene isolated from the epicarp of Hymenaea courbaril var. altissima (Leguminosaea, Cesalpinoideae, Detariae), was fully assigned by COSY experiments, 13C/1H shift correlation diagrams and NOE experiments. Copyright 2004 John Wiley & Sons, Ltd.

ERP Correlates of Language-Specific Processing of Auditory Pitch Feedback during Self-Vocalization

ERIC Educational Resources Information Center

Chen, Zhaocong; Liu, Peng; Wang, Emily Q.; Larson, Charles R.; Huang, Dongfeng; Liu, Hanjun

2012-01-01

The present study investigated whether the neural correlates for auditory feedback control of vocal pitch can be shaped by tone language experience. Event-related potentials (P2/N1) were recorded from adult native speakers of Mandarin and Cantonese who heard their voice auditory feedback shifted in pitch by -50, -100, -200, or -500 cents when they…

Spatially Resolved Sensitivity of Single-Particle Plasmon Sensors

PubMed Central

2018-01-01

The high sensitivity of localized surface plasmon resonance sensors to the local refractive index allows for the detection of single-molecule binding events. Though binding events of single objects can be detected by their induced plasmon shift, the broad distribution of observed shifts remains poorly understood. Here, we perform a single-particle study wherein single nanospheres bind to a gold nanorod, and relate the observed plasmon shift to the binding location using correlative microscopy. To achieve this we combine atomic force microscopy to determine the binding location, and single-particle spectroscopy to determine the corresponding plasmon shift. As expected, we find a larger plasmon shift for nanospheres binding at the tip of a rod compared to its sides, in good agreement with numerical calculations. However, we also find a broad distribution of shifts even for spheres that were bound at a similar location to the nanorod. Our correlative approach allows us to disentangle effects of nanoparticle dimensions and binding location, and by comparison to numerical calculations we find that the biggest contributor to this observed spread is the dispersion in nanosphere diameter. These experiments provide insight into the spatial sensitivity and signal-heterogeneity of single-particle plasmon sensors and provides a framework for signal interpretation in sensing applications. PMID:29520315

Differential Neural Correlates of Set-Shifting in the Bingeing-Purging and Restrictive Subtypes of Anorexia Nervosa: An fMRI Study.

PubMed

Van Autreve, Sara; De Baene, Wouter; Baeken, Chris; van Heeringen, Kees; Vancayseele, Nikita; Vervaet, Myriam

2016-07-01

In this study, possible differences in the neural correlates of set-shifting abilities between the restrictive (AN-R) and bingeing/purging (AN-BP) subtypes of anorexia nervosa have been explored. Three groups of participants performed a set-shifting task during functional magnetic resonance imaging: patients with AN-R (N = 16), AN-BP (N = 13) and healthy control participants (N = 15). As in a typical set-shifting experiment, participants had to switch between two easy tasks (i.e. 'Is the presented number odd/even' or 'Is the presented number smaller/larger than 5'). The trials in which the task was repeated (repeat trials) were compared with trials in which the task was switched (switch trials). With regards to the level of task performance, no significant group differences could be established. However, when comparing switch specific brain activity across study groups, a stronger activation was found in the insula and the precuneus in AN-R when compared to AN-BP and HC. These results suggest that the both subtypes of AN might have different neurobiological correlates, and thus, might benefit from different treatment approaches. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Stability of monitoring weak changes in multiply scattering media with ambient noise correlation: laboratory experiments.

PubMed

Hadziioannou, Céline; Larose, Eric; Coutant, Olivier; Roux, Philippe; Campillo, Michel

2009-06-01

Previous studies have shown that small changes can be monitored in a scattering medium by observing phase shifts in the coda. Passive monitoring of weak changes through ambient noise correlation has already been applied to seismology, acoustics, and engineering. Usually, this is done under the assumption that a properly reconstructed Green function (GF), as well as stable background noise sources, is necessary. In order to further develop this monitoring technique, a laboratory experiment was performed in the 2.5 MHz range in a gel with scattering inclusions, comparing an active (pulse-echo) form of monitoring to a passive (correlation) one. Present results show that temperature changes in the medium can be observed even if the GF of the medium is not reconstructed. Moreover, this article establishes that the GF reconstruction in the correlations is not a necessary condition: The only condition to monitoring with correlation (passive experiment) is the relative stability of the background noise structure.

Hybrid Theory of Electron-Hydrogenic Systems Elastic Scattering

NASA Technical Reports Server (NTRS)

Bhatia, A. K.

2007-01-01

Accurate electron-hydrogen and electron-hydrogenic cross sections are required to interpret fusion experiments, laboratory plasma physics and properties of the solar and astrophysical plasmas. We have developed a method in which the short-range and long-range correlations can be included at the same time in the scattering equations. The phase shifts have rigorous lower bounds and the scattering lengths have rigorous upper bounds. The phase shifts in the resonance region can be used to calculate very accurately the resonance parameters.

Rotational and translational dynamics and their relation to hydrogen bond lifetimes in an ionic liquid by means of NMR relaxation time experiments and molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Strate, Anne; Neumann, Jan; Overbeck, Viviane; Bonsa, Anne-Marie; Michalik, Dirk; Paschek, Dietmar; Ludwig, Ralf

2018-05-01

We report a concerted theoretical and experimental effort to determine the reorientational dynamics as well as hydrogen bond lifetimes for the doubly ionic hydrogen bond +OH⋯O- in the ionic liquid (2-hydroxyethyl)trimethylammonium bis(trifluoromethylsulfonyl)imide [Ch][NTf2] by using a combination of NMR relaxation time experiments, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations. Due to fast proton exchange, the determination of rotational correlation times is challenging. For molecular liquids, 17O-enhanced proton relaxation time experiments have been used to determine the rotational correlation times for the OH vectors in water or alcohols. As an alternative to those expensive isotopic substitution experiments, we employed a recently introduced approach which is providing access to the rotational dynamics from a single NMR deuteron quadrupolar relaxation time experiment. Here, the deuteron quadrupole coupling constants (DQCCs) are obtained from a relation between the DQCC and the δ1H proton chemical shifts determined from a set of DFT calculated clusters in combination with experimentally determined proton chemical shifts. The NMR-obtained rotational correlation times were compared to those obtained from MD simulations and then related to viscosities for testing the applicability of popular hydrodynamic models. In addition, hydrogen bond lifetimes were derived, using hydrogen bond population correlation functions computed from MD simulations. Here, two different time domains were observed: The short-time contributions to the hydrogen lifetimes and the reorientational correlation times have roughly the same size and are located in the picosecond range, whereas the long-time contributions decay with relaxation times in the nanosecond regime and are related to rather slow diffusion processes. The computed average hydrogen bond lifetime is dominated by the long-time process, highlighting the importance and longevity of hydrogen-bonded ion pairs in these ionic liquids.

Tensor network states in time-bin quantum optics

NASA Astrophysics Data System (ADS)

Lubasch, Michael; Valido, Antonio A.; Renema, Jelmer J.; Kolthammer, W. Steven; Jaksch, Dieter; Kim, M. S.; Walmsley, Ian; García-Patrón, Raúl

2018-06-01

The current shift in the quantum optics community towards experiments with many modes and photons necessitates new classical simulation techniques that efficiently encode many-body quantum correlations and go beyond the usual phase-space formulation. To address this pressing demand we formulate linear quantum optics in the language of tensor network states. We extensively analyze the quantum and classical correlations of time-bin interference in a single fiber loop. We then generalize our results to more complex time-bin quantum setups and identify different classes of architectures for high-complexity and low-overhead boson sampling experiments.

Adaptive Cross-correlation Algorithm and Experiment of Extended Scene Shack-Hartmann Wavefront Sensing

NASA Technical Reports Server (NTRS)

Sidick, Erkin; Morgan, Rhonda M.; Green, Joseph J.; Ohara, Catherine M.; Redding, David C.

2007-01-01

We have developed a new, adaptive cross-correlation (ACC) algorithm to estimate with high accuracy the shift as large as several pixels in two extended-scene images captured by a Shack-Hartmann wavefront sensor (SH-WFS). It determines the positions of all of the extended-scene image cells relative to a reference cell using an FFT-based iterative image shifting algorithm. It works with both point-source spot images as well as extended scene images. We have also set up a testbed for extended0scene SH-WFS, and tested the ACC algorithm with the measured data of both point-source and extended-scene images. In this paper we describe our algorithm and present out experimental results.

Natural Abundance 15 N and 13 C Solid-State NMR Chemical Shifts: High Sensitivity Probes of the Halogen Bond Geometry.

PubMed

Cerreia Vioglio, Paolo; Catalano, Luca; Vasylyeva, Vera; Nervi, Carlo; Chierotti, Michele R; Resnati, Giuseppe; Gobetto, Roberto; Metrangolo, Pierangelo

2016-11-14

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a versatile characterization technique that can provide a plethora of information complementary to single crystal X-ray diffraction (SCXRD) analysis. Herein, we present an experimental and computational investigation of the relationship between the geometry of a halogen bond (XB) and the SSNMR chemical shifts of the non-quadrupolar nuclei either directly involved in the interaction ( 15 N) or covalently bonded to the halogen atom ( 13 C). We have prepared two series of X-bonded co-crystals based upon two different dipyridyl modules, and several halobenzenes and diiodoalkanes, as XB-donors. SCXRD structures of three novel co-crystals between 1,2-bis(4-pyridyl)ethane, and 1,4-diiodobenzene, 1,6-diiodododecafluorohexane, and 1,8-diiodohexadecafluorooctane were obtained. For the first time, the change in the 15 N SSNMR chemical shifts upon XB formation is shown to experimentally correlate with the normalized distance parameter of the XB. The same overall trend is confirmed by density functional theory (DFT) calculations of the chemical shifts. 13 C NQS experiments show a positive, linear correlation between the chemical shifts and the C-I elongation, which is an indirect probe of the strength of the XB. These correlations can be of general utility to estimate the strength of the XB occurring in diverse adducts by using affordable SSNMR analysis. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of the effect of shift work on serum cholesterol and triglyceride levels.

PubMed

Akbari, Hamed; Mirzaei, Ramazan; Nasrabadi, Tahereh; Gholami-Fesharaki, Mohammad

2015-01-01

Working outside daylight hours (7 am to 7 pm) is called shift work. Shift work is a common practice in many industries and factories such as steel industries, petroleum industries, power plants, and in some services such as medicine and nursing and police forces, in which professionals provide services during day and night. Considering the contradictory reports of different studies, we decided to evaluate the effect of shift work on cholesterol and triglyceride (TG) levels through a historical cohort on steel industry workers. This retrospective cohort study was performed on all the staff of Isfahan's Mobarakeh Steel Company between years 2002 and 2011. There were 5773 participants in this study. Data were collected from the medical records of the staff using the census method. For analysis of data, generalized estimating equation (GEE) regression was used. The results showed a significant difference in cholesterol levels between shift workers and day workers on the first observation (P < 0.001), yet no such difference was observed for TG (P = 0.853). Moreover, the results showed that the variables of age, work experience and BMI were not similar between shift workers and day workers. Therefore, to remove the effect of such variables, we used GEE regression. Despite the borderline difference of cholesterol between regular shift workers and day workers, this correlation was not statistically significant (P = 0.051). The results for TG also showed no correlation with shift work. According to the findings of this study, there is no relationship between shift work and changes in serum TG and cholesterol. The lack of relationship can be due to shift plans for shift workers, nutrition, or the "Healthy Heart project" at Isfahan Mobarakeh Steel Company.

Theoretical NMR correlations based Structure Discussion.

PubMed

Junker, Jochen

2011-07-28

The constitutional assignment of natural products by NMR spectroscopy is usually based on 2D NMR experiments like COSY, HSQC, and HMBC. The actual difficulty of the structure elucidation problem depends more on the type of the investigated molecule than on its size. The moment HMBC data is involved in the process or a large number of heteroatoms is present, a possibility of multiple solutions fitting the same data set exists. A structure elucidation software can be used to find such alternative constitutional assignments and help in the discussion in order to find the correct solution. But this is rarely done. This article describes the use of theoretical NMR correlation data in the structure elucidation process with WEBCOCON, not for the initial constitutional assignments, but to define how well a suggested molecule could have been described by NMR correlation data. The results of this analysis can be used to decide on further steps needed to assure the correctness of the structural assignment. As first step the analysis of the deviation of carbon chemical shifts is performed, comparing chemical shifts predicted for each possible solution with the experimental data. The application of this technique to three well known compounds is shown. Using NMR correlation data alone for the description of the constitutions is not always enough, even when including 13C chemical shift prediction.

NMR crystallography of campho[2,3-c]pyrazole (Z' = 6): combining high-resolution 1H-13C solid-state MAS NMR spectroscopy and GIPAW chemical-shift calculations.

PubMed

Webber, Amy L; Emsley, Lyndon; Claramunt, Rosa M; Brown, Steven P

2010-09-30

(1)H-(13)C two-dimensional magic-angle spinning (MAS) solid-state NMR correlation spectra, recorded with the MAS-J-HMQC experiment, are presented for campho[2,3-c]pyrazole. For each (13)C moiety, there are six resonances associated with the six distinct molecules in the asymmetric unit cell (Z' = 6). The one-bond C-H correlations observed in the 2D (1)H-(13)C MAS-J-HMQC spectra allow the experimental determination of the (1)H and (13)C chemical shifts associated with the separate CH, CH(2), and CH(3) groups. (1)H and (13)C chemical shifts calculated by using the GIPAW (Gauge Including Projector Augmented Waves) plane-wave pseudopotential approach are presented. Calculations for the whole unit cell (12 × 29 = 348 atoms, with geometry optimization of all atoms) allow the assignment of the experimental (1)H and (13)C chemical shifts to the six distinct molecules. The calculated chemical shifts for the full crystal structure are compared with those for isolated molecules as extracted from the geometry-optimized crystal structure. In this way, the effect of intermolecular interactions on the observed chemical shifts is quantified. In particular, the calculations are sufficiently precise to differentiate the small (<1 ppm) differences between the (1)H chemical shifts of the six resonances associated with each distinct CH or CH(2) moiety.

Fast Face-Recognition Optical Parallel Correlator Using High Accuracy Correlation Filter

NASA Astrophysics Data System (ADS)

Watanabe, Eriko; Kodate, Kashiko

2005-11-01

We designed and fabricated a fully automatic fast face recognition optical parallel correlator [E. Watanabe and K. Kodate: Appl. Opt. 44 (2005) 5666] based on the VanderLugt principle. The implementation of an as-yet unattained ultra high-speed system was aided by reconfiguring the system to make it suitable for easier parallel processing, as well as by composing a higher accuracy correlation filter and high-speed ferroelectric liquid crystal-spatial light modulator (FLC-SLM). In running trial experiments using this system (dubbed FARCO), we succeeded in acquiring remarkably low error rates of 1.3% for false match rate (FMR) and 2.6% for false non-match rate (FNMR). Given the results of our experiments, the aim of this paper is to examine methods of designing correlation filters and arranging database image arrays for even faster parallel correlation, underlining the issues of calculation technique, quantization bit rate, pixel size and shift from optical axis. The correlation filter has proved its excellent performance and higher precision than classical correlation and joint transform correlator (JTC). Moreover, arrangement of multi-object reference images leads to 10-channel correlation signals, as sharply marked as those of a single channel. This experiment result demonstrates great potential for achieving the process speed of 10000 face/s.

Reaction monitoring using hyperpolarized NMR with scaling of heteronuclear couplings by optimal tracking

NASA Astrophysics Data System (ADS)

Zhang, Guannan; Schilling, Franz; Glaser, Steffen J.; Hilty, Christian

2016-11-01

Off-resonance decoupling using the method of Scaling of Heteronuclear Couplings by Optimal Tracking (SHOT) enables determination of heteronuclear correlations of chemical shifts in single scan NMR spectra. Through modulation of J-coupling evolution by shaped radio frequency pulses, off resonance decoupling using SHOT pulses causes a user-defined dependence of the observed J-splitting, such as the splitting of 13C peaks, on the chemical shift offset of coupled nuclei, such as 1H. Because a decoupling experiment requires only a single scan, this method is suitable for characterizing on-going chemical reactions using hyperpolarization by dissolution dynamic nuclear polarization (D-DNP). We demonstrate the calculation of [13C, 1H] chemical shift correlations of the carbanionic active sites from hyperpolarized styrene polymerized using sodium naphthalene as an initiator. While off resonance decoupling by SHOT pulses does not enhance the resolution in the same way as a 2D NMR spectrum would, the ability to obtain the correlations in single scans makes this method ideal for determination of chemical shifts in on-going reactions on the second time scale. In addition, we present a novel SHOT pulse that allows to scale J-splittings 50% larger than the respective J-coupling constant. This feature can be used to enhance the resolution of the indirectly detected chemical shift and reduce peak overlap, as demonstrated in a model reaction between p-anisaldehyde and isobutylamine. For both pulses, the accuracy is evaluated under changing signal-to-noise ratios (SNR) of the peaks from reactants and reaction products, with an overall standard deviation of chemical shift differences compared to reference spectra of 0.02 ppm when measured on a 400 MHz NMR spectrometer. Notably, the appearance of decoupling side-bands, which scale with peak intensity, appears to be of secondary importance.

Beauty in abstract paintings: perceptual contrast and statistical properties

PubMed Central

Mallon, Birgit; Redies, Christoph; Hayn-Leichsenring, Gregor U.

2014-01-01

In this study, we combined the behavioral and objective approach in the field of empirical aesthetics. First, we studied the perception of beauty by investigating shifts in evaluation on perceived beauty of abstract artworks (Experiment 1). Because the participants showed heterogeneous individual preferences for the paintings, we divided them into seven clusters for the test. The experiment revealed a clear pattern of perceptual contrast. The perceived beauty of abstract paintings increased after exposure to paintings that were rated as less beautiful, and it decreased after exposure to paintings that were rated as more beautiful. Next, we searched for correlations of beauty ratings and perceptual contrast with statistical properties of abstract artworks (Experiment 2). The participants showed significant preferences for particular image properties. These preferences differed between the clusters of participants. Strikingly, next to color measures like hue, saturation, value and lightness, the recently described Pyramid of Histograms of Orientation Gradients (PHOG) self-similarity value seems to be a predictor for aesthetic appreciation of abstract artworks. We speculate that the shift in evaluation in Experiment 1 was, at least in part, based on low-level adaptation to some of the statistical image properties analyzed in Experiment 2. In conclusion, our findings demonstrate that the perception of beauty in abstract artworks is altered after exposure to beautiful or non-beautiful images and correlates with particular image properties, especially color measures and self-similarity. PMID:24711791

Shift climate profiles and correlates in acute psychiatric inpatient units.

PubMed

Lewin, Terry J; Carr, Vaughan J; Conrad, Agatha M; Sly, Ketrina A; Tirupati, Srinivasan; Cohen, Martin; Ward, Philip B; Coombs, Tim

2012-09-01

Inpatient psychiatric units are dynamic in nature, potentially creating a different treatment experience for each person, which may be difficult to quantify. Among the goals of this multi-centre service evaluation project was an assessment of shift-to-shift changes in unit-level events and their impact on the social-emotional environment. Over 1 year, various nurse-completed logs were used within the 11 participating Australian psychiatric units (n = 5,546 admissions) to record patient- and unit-level events per shift, including ratings of the overall social-emotional climate using a novel shift climate ratings (SCR) scale (n = 8,176 shifts). These were combined with admission-level patient characteristics to investigate shift climate profiles and correlates. Occupancy rates averaged 88% and two-thirds of admissions were involuntary. The psychometric performance of the SCR scale was considered to be satisfactory (e.g., high internal consistency, unidimensional factor structure, and evidence of discriminant and predictive validity). A series of hierarchical regressions revealed considerable variation in SCR total scores, with poorer climates being significantly associated with: day/afternoon shifts; higher occupancy levels; higher proportions of experienced staff, and male, older, or involuntary patients; higher rates of less serious aggressive incidents; reporting of additional staffing demands; and unit location in a stand-alone psychiatric hospital. The day-to-day social-emotional climate can have important consequences for patient engagement and recovery. Improved understanding of the role played by unit, staff and patient characteristics, together with routine monitoring, should facilitate the development and evaluation of targeted interventions to reduce adverse incidents and improve the overall social-emotional climate.

Assessing age stereotypes in the German population in 1996 and 2011: socio-demographic correlates and shift over time.

PubMed

Spangenberg, Lena; Zenger, Markus; Glaesmer, Heide; Brähler, Elmar; Strauss, Bernhard

2018-03-01

The present study aimed to extend the knowledge regarding dimensionality, socio-demographic correlates and shifts in age stereotypes over the past 15 years using a time-sequential design. In 1996 and 2011, we assessed age stereotypes in two independent samples of the German population aged ≥ 45 years ( N  = 970 in sample 1, N  = 1545 in sample 2). Three scales with six items each were assessed. Two scales cover negative (i.e., rigidity/isolation, burden), and one scale covers positive age stereotypes (wisdom/experience). Dimensionality of the scale, associations with socio-demographic variables and whether the stereotypes have shifted were tested using confirmatory factor analyses, structural equation modeling and analyses of variances. Three dimensions were identified and replicated following an exploratory as well as a confirmatory approach. Age stereotypes did shift between 1996 and 2011 in the dimension burden (i.e., becoming more negative). Our results further underpin the finding that age stereotypes are multifaceted and suggest that dimensions do not change over time. Additionally, our data provide some evidence that societal age stereotypes partly change over time.

Gray matter correlates of set-shifting among neurodegenerative disease, mild cognitive impairment, and healthy older adults

PubMed Central

PA, JUDY; POSSIN, KATHERINE L.; WILSON, STEPHEN M.; QUITANIA, LOVINGLY C.; KRAMER, JOEL H.; BOXER, ADAM L.; WEINER, MICHAEL W.; JOHNSON, JULENE K.

2010-01-01

There is increasing recognition that set-shifting, a form of cognitive control, is mediated by different neural structures. However, these regions have not yet been carefully identified as many studies do not account for the influence of component processes (e.g., motor speed). We investigated gray matter correlates of set-shifting while controlling for component processes. Using the Design Fluency (DF), Trail Making Test (TMT), and Color Word Interference (CWI) subtests from the Delis-Kaplan Executive Function System (D-KEFS), we investigated the correlation between set-shifting performance and gray matter volume in 160 subjects with neurodegenerative disease, mild cognitive impairment, and healthy older adults using voxel-based morphometry. All three set-shifting tasks correlated with multiple, widespread gray matter regions. After controlling for the component processes, set-shifting performance correlated with focal regions in prefrontal and posterior parietal cortices. We also identified bilateral prefrontal cortex and the right posterior parietal lobe as common sites for set-shifting across the three tasks. There was a high degree of multicollinearity between the set-shifting conditions and the component processes of TMT and CWI, suggesting DF may better isolate set-shifting regions. Overall, these findings highlight the neuroanatomical correlates of set-shifting and the importance of controlling for component processes when investigating complex cognitive tasks. PMID:20374676

Log-polar mapping-based scale space tracking with adaptive target response

NASA Astrophysics Data System (ADS)

Li, Dongdong; Wen, Gongjian; Kuai, Yangliu; Zhang, Ximing

2017-05-01

Correlation filter-based tracking has exhibited impressive robustness and accuracy in recent years. Standard correlation filter-based trackers are restricted to translation estimation and equipped with fixed target response. These trackers produce an inferior performance when encountered with a significant scale variation or appearance change. We propose a log-polar mapping-based scale space tracker with an adaptive target response. This tracker transforms the scale variation of the target in the Cartesian space into a shift along the logarithmic axis in the log-polar space. A one-dimensional scale correlation filter is learned online to estimate the shift along the logarithmic axis. With the log-polar representation, scale estimation is achieved accurately without a multiresolution pyramid. To achieve an adaptive target response, a variance of the Gaussian function is computed from the response map and updated online with a learning rate parameter. Our log-polar mapping-based scale correlation filter and adaptive target response can be combined with any correlation filter-based trackers. In addition, the scale correlation filter can be extended to a two-dimensional correlation filter to achieve joint estimation of the scale variation and in-plane rotation. Experiments performed on an OTB50 benchmark demonstrate that our tracker achieves superior performance against state-of-the-art trackers.

Quality of life, job satisfaction and their related factors among nurses working in king Abdulaziz University Hospital, Jeddah, Saudi Arabia.

PubMed

Ibrahim, Nahla Khamis; Alzahrani, Nujood Abdulwahed; Batwie, Afnan Ateeg; Abushal, Razan Abdulaziz; Almogati, Ghazwa Ghazzay; Sattam, Munirah Abdulrahman; Hussin, Bodour Khalid

2016-08-01

To assess Quality of Life, job satisfaction and their related factors among nurses working in King Abdulaziz University Hospital, Jeddah, Saudi Arabia. A cross-sectional survey was conducted among 268 nurses, 2014/2015. A validated, confidential data collection sheet was utilized. It contained the World Health Organization Quality of Life-BREF (WHOQOL-BREF), and Job Descriptive Index/Job in General (JDI/JIG) scales. The majority of nurses (83.5%) perceived their general QOL as very good and good. Age, marital status, having children, nationality, income, education, residence, working experience, department and shift time were associated with QOL domains (p < 0.05). Similarly, working experience, income, shifts, working in inpatient and surgical departments were associated with job satisfaction. Positive correlations were found between job satisfaction and different QOL domains, and between different JDI/JIG subscales together. Improvement of the modifiable factors as nurses' income and shift time is needed for better QOL and job satisfaction.

Breast cancer and symptom clusters during radiotherapy.

PubMed

Matthews, Ellyn E; Schmiege, Sarah J; Cook, Paul F; Sousa, Karen H

2012-01-01

Symptom clusters assessment shifts the clinical focus from a specific symptom to the patient's experience as a whole. Few studies have examined breast cancer symptom clusters during treatment, and fewer studies have addressed symptom clusters during radiation therapy (RT). The theoretical underpinning of this study is the Symptoms Experience Model. Research is needed to identify antecedents and consequences of cancer-related symptom clusters. The present study was intended to determine the clustering of symptoms during RT in women with breast cancer and significant correlations among the symptoms, individual characteristics, and mood. A secondary data analysis from a descriptive correlational study of 93 women at weeks 3 to 7 of RT from centers in the mid-Atlantic region of the United States, Symptom Distress Scale, the subscales of the Positive and Negative Affect Scale, Life Orientation Test, and Self-transcendence Scale were completed. Confirmatory factor analysis revealed symptoms grouped into 3 distinct clusters: pain-insomnia-fatigue, cognitive disturbance-outlook, and gastrointestinal. The pain-insomnia-fatigue and cognitive disturbance-outlook clusters were associated with individual characteristics, optimism, self-transcendence, and positive and negative mood. The gastrointestinal cluster correlated significantly only with positive mood. This study provides insight into symptoms that group together and the relationship of symptom clusters to antecedents and mood. These findings underscore the need to define and standardize the measurement of symptom clusters and understand variability in concurrent symptoms. Attention to symptom clusters shifts the clinical focus from a specific symptom to the patient's experience as a whole and helps identify the most effective interventions.

Insight into hydrogen bonding of uranyl hydroxide layers and capsules by use of 1H magic-angle spinning NMR spectroscopy [Insight into the hydrogen bonding for uranyl hydroxides using 1H MAS NMR spectroscopy

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

Alam, Todd M.; Liao, Zuolei; Nyman, May

Solid-state 1H magic-angle spinning (MAS) NMR was used to investigate local proton environments in anhydrous [UO 2(OH) 2] (α-UOH) and hydrated uranyl hydroxide [(UO 2) 4O(OH) 6·5H 2O (metaschoepite). For the metaschoepite material, proton resonances of the μ 2-OH hydroxyl and interlayer waters were resolved, with two-dimensional (2D) double-quantum (DQ) 1H– 1H NMR correlation experiments revealing strong dipolar interactions between these different proton species. The experimental NMR results were combined with first-principles CASTEP GIPAW (gauge including projector-augmented wave) chemical shift calculations to develop correlations between hydrogen-bond strength and observed 1H NMR chemical shifts. Furthermore, these NMR correlations allowed characterization ofmore » local hydrogen-bond environments in uranyl U 24 capsules and of changes in hydrogen bonding that occurred during thermal dehydration of metaschoepite.« less

Insight into hydrogen bonding of uranyl hydroxide layers and capsules by use of 1H magic-angle spinning NMR spectroscopy [Insight into the hydrogen bonding for uranyl hydroxides using 1H MAS NMR spectroscopy

DOE PAGES

Alam, Todd M.; Liao, Zuolei; Nyman, May; ...

2016-04-27

Solid-state 1H magic-angle spinning (MAS) NMR was used to investigate local proton environments in anhydrous [UO 2(OH) 2] (α-UOH) and hydrated uranyl hydroxide [(UO 2) 4O(OH) 6·5H 2O (metaschoepite). For the metaschoepite material, proton resonances of the μ 2-OH hydroxyl and interlayer waters were resolved, with two-dimensional (2D) double-quantum (DQ) 1H– 1H NMR correlation experiments revealing strong dipolar interactions between these different proton species. The experimental NMR results were combined with first-principles CASTEP GIPAW (gauge including projector-augmented wave) chemical shift calculations to develop correlations between hydrogen-bond strength and observed 1H NMR chemical shifts. Furthermore, these NMR correlations allowed characterization ofmore » local hydrogen-bond environments in uranyl U 24 capsules and of changes in hydrogen bonding that occurred during thermal dehydration of metaschoepite.« less

Results from EDDAatCOSY: Spin Observables in Proton-Proton Elastic Scattering

NASA Astrophysics Data System (ADS)

Rohdjeß, Heiko

2003-07-01

Elastic proton-proton scattering as one of the fundamental hadronic reactions has been studied with the internal target experiment EDDA at the Cooler-Synchrotron COSY/Jülich. A precise measurement of differential cross section, analyzing power and three spin-correlation parameters over a large angular (θc.m. ≈ 35° - 90°) and energy (Tp ≈ 0.5 - 2.5 GeV) range has been carried out in the past years. By taking scattering data during the acceleration of the COSY beam, excitation functions were measured in small energy steps and consistent normalization with respect to luminosity and polarization. The experiment uses internal fiber targets and a polarized hydrogen atomic-beam target in conjunction with a double-layered, cylindrical scintillator hodoscope for particle detection. The results on differential cross sections and analyzing powers have been published and helped to improve phase shift solutions. Recently data taking with polarized beam and target has been completed. Preliminary results for the spin-correlation parameters A NN, ASS, and ASL are presented. The observable ASS has been measured the first time above 800 MeV and our results are in sharp contrast to phase-shift predictions at higher energies. Our analysis shows that some of the ambiguities in the direct reconstruction of scattering amplitudes which also show up as differences between available phase-shift solutions, will be reduced by these new measurements.

Combining multinuclear high-resolution solid-state MAS NMR and computational methods for resonance assignment of glutathione tripeptide.

PubMed

Sardo, Mariana; Siegel, Renée; Santos, Sérgio M; Rocha, João; Gomes, José R B; Mafra, Luis

2012-06-28

We present a complete set of experimental approaches for the NMR assignment of powdered tripeptide glutathione at natural isotopic abundance, based on J-coupling and dipolar NMR techniques combined with (1)H CRAMPS decoupling. To fully assign the spectra, two-dimensional (2D) high-resolution methods, such as (1)H-(13)C INEPT-HSQC/PRESTO heteronuclear correlations (HETCOR), (1)H-(1)H double-quantum (DQ), and (1)H-(14)N D-HMQC correlation experiments, have been used. To support the interpretation of the experimental data, periodic density functional theory calculations together with the GIPAW approach have been used to calculate the (1)H and (13)C chemical shifts. It is found that the shifts calculated with two popular plane wave codes (CASTEP and Quantum ESPRESSO) are in excellent agreement with the experimental results.

A sequential assignment procedure for proteins that have intermediate line widths in MAS NMR spectra: amyloid fibrils of human CA150.WW2.

PubMed

Becker, Johanna; Ferguson, Neil; Flinders, Jeremy; van Rossum, Barth-Jan; Fersht, Alan R; Oschkinat, Hartmut

2008-08-11

The second WW domain (WW2) of CA150, a human transcriptional activator, forms amyloid fibrils in vitro under physiological conditions. Based on experimental constraints from MAS NMR spectroscopy experiments, alanine scanning and electron microscopy, a structural model of CA150.WW2 amyloid fibrils was calculated earlier. Here, the assignment strategy is presented and suggested as a general approach for proteins that show intermediate line width. The (13)C,(13)C correlation experiments were recorded on fully or partially (13)C-labelled fibrils. The earlier (13)C assignment (26 residues) was extended to 34 of the 40 residues by direct (13)C-excitation experiments by using a deuterated sample that showed strongly improved line width. A 3D HNC-TEDOR (transferred-echo double-resonance) experiment with deuterated CA150.WW2 fibrils yielded 14 amide nitrogen and proton resonance assignments. The obtained chemical shifts were compared with the chemical shifts determined with the natively folded WW domain. TALOS (Torsion angle likelihood obtained from shift and sequence similarity) predictions confirmed that, under physiological conditions, the fibrillar form of CA150.WW2 adopts a significantly different beta structure than the native WW-domain fold.

Shift from bird to butterfly pollination in Clivia (Amaryllidaceae).

PubMed

Kiepiel, Ian; Johnson, Steven D

2014-01-01

Pollinator shifts have been implicated as a driver of divergence in angiosperms. We tested the hypothesis that there was a transition from bird- to butterfly pollination in the African genus Clivia (Amaryllidaceae) and investigated how floral traits may have been either modified or retained during this transition. We identified pollinators using field observations, correlations between lepidopteran wing scales and pollen on stigmas, and single-visit and selective exclusion experiments. We also quantified floral rewards and advertising traits. The upright trumpet-shaped flowers of C. miniata were found to be pollinated effectively by swallowtail butterflies during both nectar-feeding and brush visits. These butterflies transfer pollen on their wings, as evidenced by positive correlations between wing scales and pollen loads on stigmas. All other Clivia species have narrow pendulous flowers that are visited by sunbirds. Selective exclusion of birds and large butterflies from flowers of two Clivia species resulted in a significant decline in seed production. From the distribution of pollination systems on available phylogenies, it is apparent that a shift took place from bird- to butterfly pollination in Clivia. This shift was accompanied by the evolution of trumpet-shaped flowers, smaller nectar volume, and emission of scent, while flower color and nectar chemistry do not appear to have been substantially modified. These results are consistent with the idea that pollinator shifts can explain major floral modifications during plant diversification.

A comparison of methods to estimate seismic phase delays--Numerical examples for coda wave interferometry

USGS Publications Warehouse

Mikesell, T. Dylan; Malcolm, Alison E.; Yang, Di; Haney, Matthew M.

2015-01-01

Time-shift estimation between arrivals in two seismic traces before and after a velocity perturbation is a crucial step in many seismic methods. The accuracy of the estimated velocity perturbation location and amplitude depend on this time shift. Windowed cross correlation and trace stretching are two techniques commonly used to estimate local time shifts in seismic signals. In the work presented here, we implement Dynamic Time Warping (DTW) to estimate the warping function – a vector of local time shifts that globally minimizes the misfit between two seismic traces. We illustrate the differences of all three methods compared to one another using acoustic numerical experiments. We show that DTW is comparable to or better than the other two methods when the velocity perturbation is homogeneous and the signal-to-noise ratio is high. When the signal-to-noise ratio is low, we find that DTW and windowed cross correlation are more accurate than the stretching method. Finally, we show that the DTW algorithm has better time resolution when identifying small differences in the seismic traces for a model with an isolated velocity perturbation. These results impact current methods that utilize not only time shifts between (multiply) scattered waves, but also amplitude and decoherence measurements. DTW is a new tool that may find new applications in seismology and other geophysical methods (e.g., as a waveform inversion misfit function).

Repetition reveals ups and downs of hippocampal, thalamic, and neocortical engagement during mnemonic decisions

PubMed Central

Reagh, Zachariah M.; Murray, Elizabeth A.; Yassa, Michael A.

2017-01-01

The extent to which current information is consistent with past experiences and our capacity to recognize or discriminate accordingly are key factors in flexible memory-guided behavior. Despite a wealth of evidence linking hippocampal and neocortical computations to these phenomena, many important factors remain poorly understood. One such factor is repeated encoding of learned information. In this experiment, participants completed a task in which study stimuli were incidentally encoded either once or three separate times during high-resolution fMRI scanning. We asked how repetition influenced recognition and discrimination memory judgments, and how this affects engagement of hippocampal and neocortical regions. Repetition revealed shifts in engagement in an anterior (ventral) CA1-thalamic-medial prefrontal network related to true and false recognition. Conversely, repetition revealed shifts in a posterior (dorsal) dentate/CA3-parahippocampal-restrosplenial network related to accurate discrimination. These differences in engagement were accompanied by task-related correlations in respective anterior and posterior networks. In particular, the anterior thalamic region observed during recognition judgments is functionally and anatomically consistent with nucleus reuniens in humans, and was found to mediate correlations between the anterior CA1 and medial prefrontal cortex. These findings offer new insights into how repeated experience affects memory and its neural substrates in hippocampal-neocortical networks. PMID:27859884

Improving spectral resolution in spatial encoding dimension of single-scan nuclear magnetic resonance 2D spin echo correlated spectroscopy

NASA Astrophysics Data System (ADS)

Lin, Liangjie; Wei, Zhiliang; Yang, Jian; Lin, Yanqin; Chen, Zhong

2014-11-01

The spatial encoding technique can be used to accelerate the acquisition of multi-dimensional nuclear magnetic resonance spectra. However, with this technique, we have to make trade-offs between the spectral width and the resolution in the spatial encoding dimension (F1 dimension), resulting in the difficulty of covering large spectral widths while preserving acceptable resolutions for spatial encoding spectra. In this study, a selective shifting method is proposed to overcome the aforementioned drawback. This method is capable of narrowing spectral widths and improving spectral resolutions in spatial encoding dimensions by selectively shifting certain peaks in spectra of the ultrafast version of spin echo correlated spectroscopy (UFSECSY). This method can also serve as a powerful tool to obtain high-resolution correlated spectra in inhomogeneous magnetic fields for its resistance to any inhomogeneity in the F1 dimension inherited from UFSECSY. Theoretical derivations and experiments have been carried out to demonstrate performances of the proposed method. Results show that the spectral width in spatial encoding dimension can be reduced by shortening distances between cross peaks and axial peaks with the proposed method and the expected resolution improvement can be achieved. Finally, the shifting-absent spectrum can be recovered readily by post-processing.

Inconsistent Range Shifts within Species Highlight Idiosyncratic Responses to Climate Warming

PubMed Central

Gibson-Reinemer, Daniel K.; Rahel, Frank J.

2015-01-01

Climate in part determines species’ distributions, and species’ distributions are shifting in response to climate change. Strong correlations between the magnitude of temperature changes and the extent of range shifts point to warming temperatures as the single most influential factor causing shifts in species’ distributions species. However, other abiotic and biotic factors may alter or even reverse these patterns. The importance of temperature relative to these other factors can be evaluated by examining range shifts of the same species in different geographic areas. When the same species experience warming in different geographic areas, the extent to which they show range shifts that are similar in direction and magnitude is a measure of temperature’s importance. We analyzed published studies to identify species that have documented range shifts in separate areas. For 273 species of plants, birds, mammals, and marine invertebrates with range shifts measured in multiple geographic areas, 42-50% show inconsistency in the direction of their range shifts, despite experiencing similar warming trends. Inconsistency of within-species range shifts highlights how biotic interactions and local, non-thermal abiotic conditions may often supersede the direct physiological effects of temperature. Assemblages show consistent responses to climate change, but this predictability does not appear to extend to species considered individually. PMID:26162013

Study of nanometer-level precise phase-shift system used in electronic speckle shearography and phase-shift pattern interferometry

NASA Astrophysics Data System (ADS)

Jing, Chao; Liu, Zhongling; Zhou, Ge; Zhang, Yimo

2011-11-01

The nanometer-level precise phase-shift system is designed to realize the phase-shift interferometry in electronic speckle shearography pattern interferometry. The PZT is used as driving component of phase-shift system and translation component of flexure hinge is developed to realize micro displacement of non-friction and non-clearance. Closed-loop control system is designed for high-precision micro displacement, in which embedded digital control system is developed for completing control algorithm and capacitive sensor is used as feedback part for measuring micro displacement in real time. Dynamic model and control model of the nanometer-level precise phase-shift system is analyzed, and high-precision micro displacement is realized with digital PID control algorithm on this basis. It is proved with experiments that the location precision of the precise phase-shift system to step signal of displacement is less than 2nm and the location precision to continuous signal of displacement is less than 5nm, which is satisfied with the request of the electronic speckle shearography and phase-shift pattern interferometry. The stripe images of four-step phase-shift interferometry and the final phase distributed image correlated with distortion of objects are listed in this paper to prove the validity of nanometer-level precise phase-shift system.

Calculation of 125Te NMR Chemical Shifts at the Full Four-Component Relativistic Level with Taking into Account Solvent and Vibrational Corrections: A Gateway to Better Agreement with Experiment.

PubMed

Rusakova, Irina L; Rusakov, Yuriy Yu; Krivdin, Leonid B

2017-06-29

Four-component relativistic calculations of 125 Te NMR chemical shifts were performed in the series of 13 organotellurium compounds, potential precursors of the biologically active species, at the density functional theory level under the nonrelativistic and four-component fully relativistic conditions using locally dense basis set scheme derived from relativistic Dyall's basis sets. The relativistic effects in tellurium chemical shifts were found to be of as much as 20-25% of the total calculated values. The vibrational and solvent corrections to 125 Te NMR chemical shifts are about, accordingly, 6 and 8% of their total values. The PBE0 exchange-correlation functional turned out to give the best agreement of calculated tellurium shifts with their experimental values giving the mean absolute percentage error of 4% in the range of ∼1000 ppm, provided all corrections are taken into account.

Progress of a Cross-correlation Based Optical Strain Measurement Technique for Detecting Radial Growth on a Rotating Disk

NASA Technical Reports Server (NTRS)

Clem, Michelle M.; Woike, Mark; Abdul-Aziz, Ali

2013-01-01

The Aeronautical Sciences Project under NASAs Fundamental Aeronautics Program is extremely interested in the development of fault detection technologies, such as optical surface measurements in the internal parts of a flow path, for in situ health monitoring of gas turbine engines. In situ health monitoring has the potential to detect flaws, i.e. cracks in key components, such as engine turbine disks, before the flaws lead to catastrophic failure. In the present study, a cross-correlation imaging technique is investigated in a proof-of-concept study as a possible optical technique to measure the radial growth and strain field on an already cracked sub-scale turbine engine disk under loaded conditions in the NASA Glenn Research Centers High Precision Rotordynamics Laboratory. The optical strain measurement technique under investigation offers potential fault detection using an applied background consisting of a high-contrast random speckle pattern and imaging the background under unloaded and loaded conditions with a CCD camera. Spinning the cracked disk at high speeds induces an external load, resulting in a radial growth of the disk of approximately 50.8-m in the flawed region and hence, a localized strain field. When imaging the cracked disk under static conditions, the disk will appear shifted. The resulting background displacements between the two images will then be measured using the two-dimensional cross-correlation algorithms implemented in standard Particle Image Velocimetry (PIV) software to track the disk growth, which facilitates calculation of the localized strain field. In order to develop and validate this optical strain measurement technique an initial proof-of-concept experiment is carried out in a controlled environment. Using PIV optimization principles and guidelines, three potential backgrounds, for future use on the rotating disk, are developed and investigated in the controlled experiment. A range of known shifts are induced on the backgrounds; reference and data images are acquired before and after the induced shift, respectively, and the images are processed using the cross- correlation algorithms in order to determine the background displacements. The effectiveness of each background at resolving the known shift is evaluated and discussed in order to choose to the most suitable background to be implemented onto a rotating disk in the Rotordynamics Lab. Although testing on the rotating disk has not yet been performed, the driving principles behind the development of the present optical technique are based upon critical aspects of the future experiment, such as the amount of expected radial growth, disk analysis, and experimental design and are therefore addressed in the paper.

Shifting Pacific storm tracks as stressors to ecosystems of western North America.

PubMed

Dannenberg, Matthew P; Wise, Erika K

2017-11-01

Much of the precipitation delivered to western North America arrives during the cool season via midlatitude Pacific storm tracks, which may experience future shifts in response to climate change. Here, we assess the sensitivity of the hydroclimate and ecosystems of western North America to the latitudinal position of cool-season Pacific storm tracks. We calculated correlations between storm track variability and three hydroclimatic variables: gridded cool-season standardized precipitation-evapotranspiration index, April snow water equivalent, and water year streamflow from a network of USGS stream gauges. To assess how historical storm track variability affected ecosystem processes, we derived forest growth estimates from a large network of tree-ring widths and land surface phenology and wildfire estimates from remote sensing. From 1980 to 2014, cool-season storm tracks entered western North America between approximately 41°N and 53°N. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. Ecosystems of the western United States were greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern United States were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. These results suggest that projected shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern United States, where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks. © 2017 John Wiley & Sons Ltd.

Reaction monitoring using hyperpolarized NMR with scaling of heteronuclear couplings by optimal tracking.

PubMed

Zhang, Guannan; Schilling, Franz; Glaser, Steffen J; Hilty, Christian

2016-11-01

Off-resonance decoupling using the method of Scaling of Heteronuclear Couplings by Optimal Tracking (SHOT) enables determination of heteronuclear correlations of chemical shifts in single scan NMR spectra. Through modulation of J-coupling evolution by shaped radio frequency pulses, off resonance decoupling using SHOT pulses causes a user-defined dependence of the observed J-splitting, such as the splitting of 13 C peaks, on the chemical shift offset of coupled nuclei, such as 1 H. Because a decoupling experiment requires only a single scan, this method is suitable for characterizing on-going chemical reactions using hyperpolarization by dissolution dynamic nuclear polarization (D-DNP). We demonstrate the calculation of [ 13 C, 1 H] chemical shift correlations of the carbanionic active sites from hyperpolarized styrene polymerized using sodium naphthalene as an initiator. While off resonance decoupling by SHOT pulses does not enhance the resolution in the same way as a 2D NMR spectrum would, the ability to obtain the correlations in single scans makes this method ideal for determination of chemical shifts in on-going reactions on the second time scale. In addition, we present a novel SHOT pulse that allows to scale J-splittings 50% larger than the respective J-coupling constant. This feature can be used to enhance the resolution of the indirectly detected chemical shift and reduce peak overlap, as demonstrated in a model reaction between p-anisaldehyde and isobutylamine. For both pulses, the accuracy is evaluated under changing signal-to-noise ratios (SNR) of the peaks from reactants and reaction products, with an overall standard deviation of chemical shift differences compared to reference spectra of 0.02ppm when measured on a 400MHz NMR spectrometer. Notably, the appearance of decoupling side-bands, which scale with peak intensity, appears to be of secondary importance. Copyright © 2016 Elsevier Inc. All rights reserved.

Light-Induced resetting of the circadian pacemaker: quantitative analysis of transient versus steady-state phase shifts.

PubMed

Watanabe, K; Deboer, T; Meijer, J H

2001-12-01

The suprachiasmatic nuclei of the hypothalamus contain the major circadian pacemaker in mammals, driving circadian rhythms in behavioral and physiological functions. This circadian pacemaker's responsiveness to light allows synchronization to the light-dark cycle. Phase shifting by light often involves several transient cycles in which the behavioral activity rhythm gradually shifts to its steady-state position. In this article, the authors investigate in Syrian hamsters whether a phase-advancing light pulse results in immediate shifts of the PRC at the next circadian cycle. In a first series of experiments, the authors aimed a light pulse at CT 19 to induce a phase advance. It appeared that the steady-state phase advances were highly correlated with activity onset in the first and second transient cycle. This enabled them to make a reliable estimate of the steady-state phase shift induced by a phase-advancing light pulse on the basis of activity onset in the first transient cycle. In the next series of experiments, they presented a light pulse at CT 19, which was followed by a second light pulse aimed at the delay zone of the PRC on the next circadian cycle. The immediate and steady-state phase delays induced by the second light pulse were compared with data from a third experiment in which animals received a phase-delaying light pulse only. The authors observed that the waveform of the phase-delay part of the PRC (CT 12-16) obtained in Experiment 2 was virtually identical to the phase-delay part of the PRC for a single light pulse (obtained in Experiment 3). This finding allowed for a quantitative assessment of the data. The analysis indicates that the delay part of the PRC-between CT 12 and CT 16-is rapidly reset following a light pulse at CT 19. These findings complement earlier findings in the hamster showing that after a light pulse at CT 19, the phase-advancing part of the PRC is immediately shifted. Together, the data indicate that the basis for phase advancing involves rapid resetting of both advance and delay components of the PRC.

A computer-based measure of resultant achievement motivation.

PubMed

Blankenship, V

1987-08-01

Three experiments were conducted to develop a computer-based measure of individual differences in resultant achievement motivation (RAM) on the basis of level-of-aspiration, achievement motivation, and dynamics-of-action theories. In Experiment 1, the number of atypical shifts and greater responsiveness to incentives on 21 trials with choices among easy, intermediate, and difficult levels of an achievement-oriented game were positively correlated and were found to differentiate the 62 subjects (31 men, 31 women) on the amount of time they spent at a nonachievement task (watching a color design) 1 week later. In Experiment 2, test-retest reliability was established with the use of 67 subjects (15 men, 52 women). Point and no-point trials were offered in blocks, with point trials first for half the subjects and no-point trials first for the other half. Reliability was higher for the atypical-shift measure than for the incentive-responsiveness measure and was higher when points were offered first. In Experiment 3, computer anxiety was manipulated by creating a simulated computer breakdown in the experimental condition. Fifty-nine subjects (13 men, 46 women) were randomly assigned to the experimental condition or to one of two control conditions (an interruption condition and a no-interruption condition). Subjects with low RAM, as demonstrated by a low number of typical shifts, took longer to choose the achievement-oriented task, as predicted by the dynamics-of-action theory. The difference was evident in all conditions and most striking in the computer-breakdown condition. A change of focus from atypical to typical shifts is discussed.

Pupillary correlates of covert shifts of attention during working memory maintenance.

PubMed

Unsworth, Nash; Robison, Matthew K

2017-04-01

The pupillary light reflex (PLR) was used to track covert shifts of attention to items maintained in visual working memory (VWM). In three experiments, participants performed a change detection task in which rectangles appeared on either side of fixation and at test participants indicated if the cued rectangle changed its orientation. Prior to presentation or during the delay, participants were cued to the light or dark side of the screen. When cued to the light side, the pupil constricted, and when cued to the dark side, the pupil dilated, suggesting that the PLR tracked covert shifts of attention. Similar covert shifts of attention were seen when the target stimuli remained onscreen and during a blank delay period, suggesting similar effects for attention to perceptual stimuli and attention to stimuli maintained in VWM. Furthermore, similar effects were demonstrated when participants were pre-cued or retro-cued to the prioritized location, suggesting that shifts of covert attention can occur both before and after target presentation. These results are consistent with prior research, suggesting an important role of covert shifts of attention during VWM maintenance and that the PLR can be used to track these covert shifts of attention.

Neural correlates of cognitive processing in monolinguals and bilinguals

PubMed Central

Grundy, John G.; Anderson, John A.E.; Bialystok, Ellen

2017-01-01

Here we review the neural correlates of cognitive control associated with bilingualism. We demonstrate that lifelong practice managing two languages orchestrates global changes to both the structure and function of the brain. Compared with monolinguals, bilinguals generally show greater gray matter volume, especially in perceptual/motor regions, greater white matter integrity, and greater functional connectivity between gray matter regions. These changes complement electroencephalography findings showing that bilinguals devote neural resources earlier than monolinguals. Parallel functional findings emerge from the functional magnetic resonance imaging literature: bilinguals show reduced frontal activity, suggesting that they do not need to rely on top-down mechanisms to the same extent as monolinguals. This shift for bilinguals to rely more on subcortical/posterior regions, which we term the bilingual anterior-to-posterior and subcortical shift (BAPSS), fits with results from cognitive aging studies and helps to explain why bilinguals experience cognitive decline at later stages of development than monolinguals. PMID:28415142

ANGULAR DEPENDENCE OF THE POLARIZATION CORRELATION Cnn AND RECONSTRUCTION OF THE AMPLITUDE MODULI FOR pp SCATTERING AT 640 Mev. ESTIMATION OF THE SINGLET PHASE SHIFTS. PART II (in Russian)

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

Golovin, B.M.; Dzhelepov, V.P.; Zulkarneev, R.Ya.

1963-01-01

ABS>Experiments on triple scattering of protons are described, and the results of measurement of the spin correlation coefficients C/sub nn/ for 640-Mev protons elastically scattered by protons are presented for a number of angles in the cms which differ from 90 deg . On basis of the experimental data obtained in the presert work and available in the literature, the moduli of the pp-scattering amplitudes are qualitatively determined in a broad angular range 50 deg < yields < 130 deg and their relative contributions are given. The values of the singlet and triplet cross sections for some angles are alsomore » determined. The phase shifts for a pp-system at the indicated energy in singlet states are estimated. (auth)« less

Simultaneous acquisition of 2D and 3D solid-state NMR experiments for sequential assignment of oriented membrane protein samples.

PubMed

Gopinath, T; Mote, Kaustubh R; Veglia, Gianluigi

2015-05-01

We present a new method called DAISY (Dual Acquisition orIented ssNMR spectroScopY) for the simultaneous acquisition of 2D and 3D oriented solid-state NMR experiments for membrane proteins reconstituted in mechanically or magnetically aligned lipid bilayers. DAISY utilizes dual acquisition of sine and cosine dipolar or chemical shift coherences and long living (15)N longitudinal polarization to obtain two multi-dimensional spectra, simultaneously. In these new experiments, the first acquisition gives the polarization inversion spin exchange at the magic angle (PISEMA) or heteronuclear correlation (HETCOR) spectra, the second acquisition gives PISEMA-mixing or HETCOR-mixing spectra, where the mixing element enables inter-residue correlations through (15)N-(15)N homonuclear polarization transfer. The analysis of the two 2D spectra (first and second acquisitions) enables one to distinguish (15)N-(15)N inter-residue correlations for sequential assignment of membrane proteins. DAISY can be implemented in 3D experiments that include the polarization inversion spin exchange at magic angle via I spin coherence (PISEMAI) sequence, as we show for the simultaneous acquisition of 3D PISEMAI-HETCOR and 3D PISEMAI-HETCOR-mixing experiments.

Residual strain sensor using Al-packaged optical fiber and Brillouin optical correlation domain analysis.

PubMed

Choi, Bo-Hun; Kwon, Il-Bum

2015-03-09

We propose a distributed residual strain sensor that uses an Al-packaged optical fiber for the first time. The residual strain which causes Brillouin frequency shifts in the optical fiber was measured using Brillouin optical correlation domain analysis with 2 cm spatial resolution. We quantified the Brillouin frequency shifts in the Al-packaged optical fiber by the tensile stress and compared them for a varying number of Al layers in the optical fiber. The Brillouin frequency shift of an optical fiber with one Al layer had a slope of 0.038 MHz/με with respect to tensile stress, which corresponds to 78% of that for an optical fiber without Al layers. After removal of the stress, 87% of the strain remained as residual strain. When different tensile stresses were randomly applied, the strain caused by the highest stress was the only one detected as residual strain. The residual strain was repeatedly measured for a time span of nine months for the purpose of reliability testing, and there was no change in the strain except for a 4% reduction, which is within the error tolerance of the experiment. A composite material plate equipped with our proposed Al-packaged optical fiber sensor was hammered for impact experiment and the residual strain in the plate was successfully detected. We suggest that the Al-packaged optical fiber can be adapted as a distributed strain sensor for smart structures, including aerospace structures.

Visual attention shifting in autism spectrum disorders.

PubMed

Richard, Annette E; Lajiness-O'Neill, Renee

2015-01-01

Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be related to restricted and repetitive behaviors in these disorders.

Novel 2D Triple-Resonance NMR Experiments for Sequential Resonance Assignments of Proteins

NASA Astrophysics Data System (ADS)

Ding, Keyang; Gronenborn, Angela M.

2002-06-01

We present 2D versions of the popular triple resonance HN(CO) CACB, HN(COCA)CACB, HN(CO)CAHA, and HN(COCA) CAHA experiments, commonly used for sequential resonance assignments of proteins. These experiments provide information about correlations between amino proton and nitrogen chemical shifts and the α- and β-carbon and α-proton chemical shifts within and between amino acid residues. Using these 2D spectra, sequential resonance assignments of H N, N, C α, C β, and H α nuclei are easily achieved. The resolution of these spectra is identical to the well-resolved 2D 15N- 1H HSQC and H(NCO)CA spectra, with slightly reduced sensitivity compared to their 3D and 4D versions. These types of spectra are ideally suited for exploitation in automated assignment procedures and thereby constitute a fast and efficient means for NMR structural determination of small and medium-sized proteins in solution in structural genomics programs.

On the Dynamic Nature of Response Criterion in Recognition Memory: Effects of Base Rate, Awareness, and Feedback

ERIC Educational Resources Information Center

Rhodes, Matthew G.; Jacoby, Larry L.

2007-01-01

The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3…

Delay estimation in digital correlation interferometers with special consideration of the MK 2 system of the Max-Planck Institute of Radio Astronomy

NASA Astrophysics Data System (ADS)

Beyer, W. K. G.

The estimation accuracy of the group delay measured in a single video frequency band was analyzed as a function of the system bandwidth and the signal to noise ratio. Very long base interferometry (VLBI) measurements from geodetic experiments were used to check the geodetic applicability of the Mark 2 evaluation system. The geodetic observation quantities and the correlation geometry are introduced. The data flow in the VLBI experiment, the correlation analysis, the analyses and evaluation in the MK2 system, and the delay estimation procedure following the least squares method are presented. It is shown that the MK2 system is no longer up to date for geodetic applications. The superiority of the developed estimation method with respect to the interpolation algorithm is demonstrated. The numerical investigations show the deleterious influence of the distorting bit shift effects.

[Effects of water stress on red-edge parameters and yield in wheat cropping].

PubMed

He, Ke-Xun; Zaho, Shu-He; Lai, Jian-Bin; Luo, Yun-Xiao; Qin, Zhi-Hao

2013-08-01

The objective of the present paper is to study the influence of water stress on wheat spectrum red edge parameters by using field wheat spectrum data obtained from water stress experiment. Firstly, the authors analyzed the influence of water stress on wheat spectrum reflectance. Then the authors got the wheat red edge position and red edge peak through calculating wheat spectrum first-order differential and analyzed the influence of water stress on wheat red edge parameters. Finally the authors discussed the relationship between red peak and wheat yield. The results showed that the wheat red edge position shows "red shift" at the beginning of the wheat growth period and "blue shift" at the later period of the wheat growth period under the water stress experiment. Also, the red edge peak of the wheat showed that red edge peak increased with the water stress sharpening at the beginning of the wheat growth period, and then the red edge peak reduced with the water stress sharpening. The wheat red edge peak presented positive correlation with the wheat yield before the elongation period, and exhibited negative correlation after that period.

Calibration of visually guided reaching is driven by error-corrective learning and internal dynamics.

PubMed

Cheng, Sen; Sabes, Philip N

2007-04-01

The sensorimotor calibration of visually guided reaching changes on a trial-to-trial basis in response to random shifts in the visual feedback of the hand. We show that a simple linear dynamical system is sufficient to model the dynamics of this adaptive process. In this model, an internal variable represents the current state of sensorimotor calibration. Changes in this state are driven by error feedback signals, which consist of the visually perceived reach error, the artificial shift in visual feedback, or both. Subjects correct for > or =20% of the error observed on each movement, despite being unaware of the visual shift. The state of adaptation is also driven by internal dynamics, consisting of a decay back to a baseline state and a "state noise" process. State noise includes any source of variability that directly affects the state of adaptation, such as variability in sensory feedback processing, the computations that drive learning, or the maintenance of the state. This noise is accumulated in the state across trials, creating temporal correlations in the sequence of reach errors. These correlations allow us to distinguish state noise from sensorimotor performance noise, which arises independently on each trial from random fluctuations in the sensorimotor pathway. We show that these two noise sources contribute comparably to the overall magnitude of movement variability. Finally, the dynamics of adaptation measured with random feedback shifts generalizes to the case of constant feedback shifts, allowing for a direct comparison of our results with more traditional blocked-exposure experiments.

Compressive self-interference Fresnel digital holography with faithful reconstruction

NASA Astrophysics Data System (ADS)

Wan, Yuhong; Man, Tianlong; Han, Ying; Zhou, Hongqiang; Wang, Dayong

2017-05-01

We developed compressive self-interference digital holographic approach that allows retrieving three-dimensional information of the spatially incoherent objects from single-shot captured hologram. The Fresnel incoherent correlation holography is combined with parallel phase-shifting technique to instantaneously obtain spatial-multiplexed phase-shifting holograms. The recording scheme is regarded as compressive forward sensing model, thus the compressive-sensing-based reconstruction algorithm is implemented to reconstruct the original object from the under sampled demultiplexed sub-holograms. The concept was verified by simulations and experiments with simulating use of the polarizer array. The proposed technique has great potential to be applied in 3D tracking of spatially incoherent samples.

Measurements of relative chemical shift tensor orientations in solid-state NMR: new slow magic angle spinning dipolar recoupling experiments.

PubMed

Jurd, Andrew P S; Titman, Jeremy J

2009-08-28

Solid-state NMR experiments can be used to determine conformational parameters, such as interatomic distances and torsion angles. The latter can be obtained from measurements of the relative orientation of two chemical shift tensors, if the orientation of these with respect to the surrounding bonds is known. In this paper, a new rotor-synchronized magic angle spinning (MAS) dipolar correlation experiment is described which can be used in this way. Because the experiment requires slow MAS rates, a novel recoupling sequence, designed using symmetry principles, is incorporated into the mixing period. This recoupling sequence is based in turn on a new composite cyclic pulse referred to as COAST (for combined offset and anisotropy stabilization). The new COAST-C7(2)(1) sequence is shown to give good theoretical and experimental recoupling efficiency, even when the CSA far exceeds the MAS rate. In this regime, previous recoupling sequences, such as POST-C7(2)(1), exhibit poor recoupling performance. The effectiveness of the new method has been explored by a study of the dipeptide L-phenylalanyl-L-phenylalanine.

J-GFT NMR for precise measurement of mutually correlated nuclear spin-spin couplings.

PubMed

Atreya, Hanudatta S; Garcia, Erwin; Shen, Yang; Szyperski, Thomas

2007-01-24

G-matrix Fourier transform (GFT) NMR spectroscopy is presented for accurate and precise measurement of chemical shifts and nuclear spin-spin couplings correlated according to spin system. The new approach, named "J-GFT NMR", is based on a largely extended GFT NMR formalism and promises to have a broad impact on projection NMR spectroscopy. Specifically, constant-time J-GFT (6,2)D (HA-CA-CO)-N-HN was implemented for simultaneous measurement of five mutually correlated NMR parameters, that is, 15N backbone chemical shifts and the four one-bond spin-spin couplings 13Calpha-1Halpha, 13Calpha-13C', 15N-13C', and 15N-1HNu. The experiment was applied for measuring residual dipolar couplings (RDCs) in an 8 kDa protein Z-domain aligned with Pf1 phages. Comparison with RDC values extracted from conventional NMR experiments reveals that RDCs are measured with high precision and accuracy, which is attributable to the facts that (i) the use of constant time evolution ensures that signals do not broaden whenever multiple RDCs are jointly measured in a single dimension and (ii) RDCs are multiply encoded in the multiplets arising from the joint sampling. This corresponds to measuring the couplings multiple times in a statistically independent manner. A key feature of J-GFT NMR, i.e., the correlation of couplings according to spin systems without reference to sequential resonance assignments, promises to be particularly valuable for rapid identification of backbone conformation and classification of protein fold families on the basis of statistical analysis of dipolar couplings.

Universal Knight shift anomaly in the periodic Anderson model

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

Jiang, M.; Curro, N. J.; Scalettar, R. T.

Here, we report a Determinant Quantum Monte Carlo investigation which quantifies the behavior of the susceptibility and the entropy in the framework of the periodic Anderson model (PAM), focussing on the evolution with different degree of conduction electron (c) -local moment (f) hybridization. These results capture the behavior observed in several experiments, including the universal behavior of the NMR Knight shift anomaly below the crossover temperature, T*. We find that T* is a measure of the onset of c-f correlations and grows with increasing hybridization. Our results suggest that the NMR Knight shift and spin-lattice relaxation rate measurements in non-Fermimore » liquid materials are strongly influenced by temperature-dependent hybridization processes. Furthermore, our results provide a microscopic basis for the phenomenological two-fluid model of Kondo lattice behavior, and its evolution with pressure and temperature.« less

Progress of a Cross-Correlation Based Optical Strain Measurement Technique for Detecting Radial Growth on a Rotating Disk

NASA Technical Reports Server (NTRS)

Clem, Michelle M.; Woike, Mark R.; Abdul-Aziz, Ali

2014-01-01

The Aeronautical Sciences Project under NASA's Fundamental Aeronautics Program is interested in the development of novel measurement technologies, such as optical surface measurements for the in situ health monitoring of critical constituents of the internal flow path. In situ health monitoring has the potential to detect flaws, i.e. cracks in key components, such as engine turbine disks, before the flaws lead to catastrophic failure. The present study, aims to further validate and develop an optical strain measurement technique to measure the radial growth and strain field of an already cracked disk, mimicking the geometry of a sub-scale turbine engine disk, under loaded conditions in the NASA Glenn Research Center's High Precision Rotordynamics Laboratory. The technique offers potential fault detection by imaging an applied high-contrast random speckle pattern under unloaded and loaded conditions with a CCD camera. Spinning the cracked disk at high speeds (loaded conditions) induces an external load, resulting in a radial growth of the disk of approximately 50.0-µm in the flawed region and hence, a localized strain field. When imaging the cracked disk under static conditions, the disk will be undistorted; however, during rotation the cracked region will grow radially, thus causing the applied particle pattern to be 'shifted'. The resulting particle displacements between the two images is measured using the two-dimensional cross-correlation algorithms implemented in standard Particle Image Velocimetry (PIV) software to track the disk growth, which facilitates calculation of the localized strain field. A random particle distribution is adhered onto the surface of the cracked disk and two bench top experiments are carried out to evaluate the technique's ability to measure the induced particle displacements. The disk is shifted manually using a translation stage equipped with a fine micrometer and a hotplate is used to induce thermal growth of the disk, causing the particles to become shifted. For both experiments, reference and test images are acquired before and after the induced shifts, respectively, and then processed using PIV software. The controlled manual translation of the disk resulted in detection of the particle displacements accurate to 1.75% of full scale and the thermal expansion experiment resulted in successful detection of the disk's thermal growth as compared to the calculated thermal expansion results. After validation of the technique through the induced shift experiments, the technique is implemented in the Rotordynamics Lab for preliminary assessment in a simulated engine environment. The discussion of the findings and plans for future work to improve upon the results are addressed in the paper.

SU-E-T-62: A Preliminary Experience of Using EPID Transit Dosimetry for Monitoring Daily Dose Variations in Radiation Treatment Delivery

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

Yao, R; Chisela, W

2015-06-15

Purpose: To investigate the use of EPID transit dosimetry for monitoring daily dose variations in radiation treatment delivery. Methods: A patient with head and neck cancer treated using nine field IMRT beams was used in this study. The prescription was 45 Gy in 25 fractions. A KV CBCT was acquired before each treatment on a Varian NTX linear accelerator. Integrated images using MV EPID were acquired for each treatment beam. Planning CT images, treatment plan, and daily integrated images were imported into a commercial QA software Dosimetry Check (v4r4 Math Resolutions, LLC, Columbia, MD) to calculate 3D dose of themore » day assuming 25 fractions treatment. Planning CT images were deformed and registered to each daily CBCT using Varian SmartAdapt (v11.MR2). ROIs were then propagated from planning CT to daily CBCT. The correlation between maximum, average dose of ROIs and ROI volume, center of mass shift, Dice Similarity Coefficient (DSC) were investigated. Results: Not all parameters investigated showed strong correlations. For PTV and CTV, the average dose has inverse correlation with their volume change (correlation coefficient −0.52, −0.50, respectively) and DSC (−0.59, −0.59, respectively). The average dose of right parotid has correlation with its volume change (0.56). The maximum dose of spinal cord has correlation with the center of mass superior-inferior shift (0.52) and inverse correlation with the center of mass anterior-posterior shift (−0.73). Conclusion: Transit dosimetry using EPID images collected during treatment delivery offers great potential to monitor daily dose variations due to patient anatomy change, motion, and setup errors in radiation treatment delivery. It can provide a patient-specific QA tool valuable for adaptive radiation therapy. Further work is needed to validate the technique.« less

Quantitative two-dimensional HSQC experiment for high magnetic field NMR spectrometers

NASA Astrophysics Data System (ADS)

Koskela, Harri; Heikkilä, Outi; Kilpeläinen, Ilkka; Heikkinen, Sami

2010-01-01

The finite RF power available on carbon channel in proton-carbon correlation experiments leads to non-uniform cross peak intensity response across carbon chemical shift range. Several classes of broadband pulses are available that alleviate this problem. Adiabatic pulses provide an excellent magnetization inversion over a large bandwidth, and very recently, novel phase-modulated pulses have been proposed that perform 90° and 180° magnetization rotations with good offset tolerance. Here, we present a study how these broadband pulses (adiabatic and phase-modulated) can improve quantitative application of the heteronuclear single quantum coherence (HSQC) experiment on high magnetic field strength NMR spectrometers. Theoretical and experimental examinations of the quantitative, offset-compensated, CPMG-adjusted HSQC (Q-OCCAHSQC) experiment are presented. The proposed experiment offers a formidable improvement to the offset performance; 13C offset-dependent standard deviation of the peak intensity was below 6% in range of ±20 kHz. This covers the carbon chemical shift range of 150 ppm, which contains the protonated carbons excluding the aldehydes, for 22.3 T NMR magnets. A demonstration of the quantitative analysis of a fasting blood plasma sample obtained from a healthy volunteer is given.

Paradigm shift in consciousness research: the child's self-awareness and abnormalities in autism, ADHD and schizophrenia.

PubMed

Lou, Hans C

2012-02-01

Self-awareness is a pivotal component of any conscious experience and conscious self-regulation of behaviour. A paralimbic network is active, specific and causal in self-awareness. Its regions interact by gamma synchrony. Gamma synchrony develops throughout infancy, childhood and adolescence into adulthood and is regulated by dopamine and other neurotransmitters via GABA interneurons. Major derailments of this network and self-awareness occur in developmental disorders of conscious self-regulation like autism, attention deficit hyperactivity disorder (ADHD) and schizophrenia. Recent research on conscious experience is no longer limited to the study of neural 'correlations' but is increasingly lending itself to the study of causality. This paradigm shift opens new perspectives for understanding the neural mechanisms of the developing self and the causal effects of their disturbance in developmental disorders. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

Probing the independence of formant control using altered auditory feedback

PubMed Central

MacDonald, Ewen N.; Purcell, David W.; Munhall, Kevin G.

2011-01-01

Two auditory feedback perturbation experiments were conducted to examine the nature of control of the first two formants in vowels. In the first experiment, talkers heard their auditory feedback with either F1 or F2 shifted in frequency. Talkers altered production of the perturbed formant by changing its frequency in the opposite direction to the perturbation but did not produce a correlated alteration of the unperturbed formant. Thus, the motor control system is capable of fine-grained independent control of F1 and F2. In the second experiment, a large meta-analysis was conducted on data from talkers who received feedback where both F1 and F2 had been perturbed. A moderate correlation was found between individual compensations in F1 and F2 suggesting that the control of F1 and F2 is processed in a common manner at some level. While a wide range of individual compensation magnitudes were observed, no significant correlations were found between individuals’ compensations and vowel space differences. Similarly, no significant correlations were found between individuals’ compensations and variability in normal vowel production. Further, when receiving normal auditory feedback, most of the population exhibited no significant correlation between the natural variation in production of F1 and F2. PMID:21361452

Regime shifts driven by dynamic correlations in gene expression noise

NASA Astrophysics Data System (ADS)

Sharma, Yogita; Dutta, Partha Sharathi

2017-08-01

Gene expression is a noisy process that leads to regime shifts between alternative steady states among individual living cells, inducing phenotypic variability. The effects of white noise on the regime shift in bistable systems have been well characterized, however little is known about such effects of colored noise (noise with nonzero correlation time). Here, we show that noise correlation time, by considering a genetic circuit of autoactivation, can have a significant effect on the regime shift between distinct phenotypic states in gene expression. We demonstrate this theoretically, using stochastic potential, stationary probability density function, and first-passage time based on the Fokker-Planck description, where the Ornstein-Uhlenbeck process is used to model colored noise. We find that an increase in noise correlation time in the degradation rate can induce a regime shift from a low to a high protein concentration state and enhance the bistable regime, while an increase in noise correlation time in the basal rate retains the bimodal distribution. We then show how cross-correlated colored noises in basal and degradation rates can induce regime shifts from a low to a high protein concentration state, but reduce the bistable regime. We also validate these results through direct numerical simulations of the stochastic differential equation. In gene expression understanding the causes of regime shift to a harmful phenotype could improve early therapeutic intervention in complex human diseases.

Investigation of a Cross-Correlation Based Optical Strain Measurement Technique for Detecting radial Growth on a Rotating Disk

NASA Technical Reports Server (NTRS)

Clem, Michelle M.; Woike, Mark R.

2013-01-01

The Aeronautical Sciences Project under NASA`s Fundamental Aeronautics Program is extremely interested in the development of novel measurement technologies, such as optical surface measurements in the internal parts of a flow path, for in situ health monitoring of gas turbine engines. In situ health monitoring has the potential to detect flaws, i.e. cracks in key components, such as engine turbine disks, before the flaws lead to catastrophic failure. In the present study, a cross-correlation imaging technique is investigated in a proof-of-concept study as a possible optical technique to measure the radial growth and strain field on an already cracked sub-scale turbine engine disk under loaded conditions in the NASA Glenn Research Center`s High Precision Rotordynamics Laboratory. The optical strain measurement technique under investigation offers potential fault detection using an applied high-contrast random speckle pattern and imaging the pattern under unloaded and loaded conditions with a CCD camera. Spinning the cracked disk at high speeds induces an external load, resulting in a radial growth of the disk of approximately 50.0-im in the flawed region and hence, a localized strain field. When imaging the cracked disk under static conditions, the disk will be undistorted; however, during rotation the cracked region will grow radially, thus causing the applied particle pattern to be .shifted`. The resulting particle displacements between the two images will then be measured using the two-dimensional cross-correlation algorithms implemented in standard Particle Image Velocimetry (PIV) software to track the disk growth, which facilitates calculation of the localized strain field. In order to develop and validate this optical strain measurement technique an initial proof-of-concept experiment is carried out in a controlled environment. Using PIV optimization principles and guidelines, three potential speckle patterns, for future use on the rotating disk, are developed and investigated in the controlled experiment. A range of known shifts are induced on the patterns; reference and data images are acquired before and after the induced shift, respectively, and the images are processed using the cross-correlation algorithms in order to determine the particle displacements. The effectiveness of each pattern at resolving the known shift is evaluated and discussed in order to choose the most suitable pattern to be implemented onto a rotating disk in the Rotordynamics Lab. Although testing on the rotating disk has not yet been performed, the driving principles behind the development of the present optical technique are based upon critical aspects of the future experiment, such as the amount of expected radial growth, disk analysis, and experimental design and are therefore addressed in the paper.

A theoretical case study of type I and type II beta-turns.

PubMed

Czinki, Eszter; Császár, Attila G; Perczel, András

2003-03-03

NMR chemical shielding anisotropy tensors have been computed by employing a medium size basis set and the GIAO-DFT(B3LYP) formalism of electronic structure theory for all of the atoms of type I and type II beta-turn models. The models contain all possible combinations of the amino acid residues Gly, Ala, Val, and Ser, with all possible side-chain orientations where applicable in a dipeptide. The several hundred structures investigated contain either constrained or optimized phi, psi, and chi dihedral angles. A statistical analysis of the resulting large database was performed and multidimensional (2D and 3D) chemical-shift/chemical-shift plots were generated. The (1)H(alpha-13)C(alpha), (13)C(alpha-1)H(alpha-13)C(beta), and (13)C(alpha-1)H(alpha-13)C' 2D and 3D plots have the notable feature that the conformers clearly cluster in distinct regions. This allows straightforward identification of the backbone and side-chain conformations of the residues forming beta-turns. Chemical shift calculations on larger For-(L-Ala)(n)-NH(2) (n=4, 6, 8) models, containing a single type I or type II beta-turn, prove that the simple models employed are adequate. A limited number of chemical shift calculations performed at the highly correlated CCSD(T) level prove the adequacy of the computational method chosen. For all nuclei, statistically averaged theoretical and experimental shifts taken from the BioMagnetic Resonance Bank (BMRB) exhibit good correlation. These results confirm and extend our previous findings that chemical shift information from selected multiple-pulse NMR experiments could be employed directly to extract folding information for polypeptides and proteins.

Importance of correlation effects in hcp iron revealed by a pressure-induced electronic topological transition.

PubMed

Glazyrin, K; Pourovskii, L V; Dubrovinsky, L; Narygina, O; McCammon, C; Hewener, B; Schünemann, V; Wolny, J; Muffler, K; Chumakov, A I; Crichton, W; Hanfland, M; Prakapenka, V B; Tasnádi, F; Ekholm, M; Aichhorn, M; Vildosola, V; Ruban, A V; Katsnelson, M I; Abrikosov, I A

2013-03-15

We discover that hcp phases of Fe and Fe(0.9)Ni(0.1) undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mössbauer center shift observed in our experiments. First-principles simulations within the dynamic mean field approach demonstrate that the transition is induced by many-electron effects. It is absent in one-electron calculations and represents a clear signature of correlation effects in hcp Fe.

Complete (1)H resonance assignment of beta-maltose from (1)H-(1)H DQ-SQ CRAMPS and (1)H (DQ-DUMBO)-(13)C SQ refocused INEPT 2D solid-state NMR spectra and first principles GIPAW calculations.

PubMed

Webber, Amy L; Elena, Bénédicte; Griffin, John M; Yates, Jonathan R; Pham, Tran N; Mauri, Francesco; Pickard, Chris J; Gil, Ana M; Stein, Robin; Lesage, Anne; Emsley, Lyndon; Brown, Steven P

2010-07-14

A disaccharide is a challenging case for high-resolution (1)H solid-state NMR because of the 24 distinct protons (14 aliphatic and 10 OH) having (1)H chemical shifts that all fall within a narrow range of approximately 3 to 7 ppm. High-resolution (1)H (500 MHz) double-quantum (DQ) combined rotation and multiple pulse sequence (CRAMPS) solid-state NMR spectra of beta-maltose monohydrate are presented. (1)H-(1)H DQ-SQ CRAMPS spectra are presented together with (1)H (DQ)-(13)C correlation spectra obtained with a new pulse sequence that correlates a high-resolution (1)H DQ dimension with a (13)C single quantum (SQ) dimension using the refocused INEPT pulse-sequence element to transfer magnetization via one-bond (13)C-(1)H J couplings. Compared to the observation of only a single broad peak in a (1)H DQ spectrum recorded at 30 kHz magic-angle spinning (MAS), the use of DUMBO (1)H homonuclear decoupling in the (1)H DQ CRAMPS experiment allows the resolution of distinct DQ correlation peaks which, in combination with first-principles chemical shift calculations based on the GIPAW (Gauge Including Projector Augmented Waves) plane-wave pseudopotential approach, enables the assignment of the (1)H resonances to the 24 distinct protons. We believe this to be the first experimental solid-state NMR determination of the hydroxyl OH (1)H chemical shifts for a simple sugar. Variable-temperature (1)H-(1)H DQ CRAMPS spectra reveal small increases in the (1)H chemical shifts of the OH resonances upon decreasing the temperature from 348 K to 248 K.

A canonical correlation analysis based EMG classification algorithm for eliminating electrode shift effect.

PubMed

Zhe Fan; Zhong Wang; Guanglin Li; Ruomei Wang

2016-08-01

Motion classification system based on surface Electromyography (sEMG) pattern recognition has achieved good results in experimental condition. But it is still a challenge for clinical implement and practical application. Many factors contribute to the difficulty of clinical use of the EMG based dexterous control. The most obvious and important is the noise in the EMG signal caused by electrode shift, muscle fatigue, motion artifact, inherent instability of signal and biological signals such as Electrocardiogram. In this paper, a novel method based on Canonical Correlation Analysis (CCA) was developed to eliminate the reduction of classification accuracy caused by electrode shift. The average classification accuracy of our method were above 95% for the healthy subjects. In the process, we validated the influence of electrode shift on motion classification accuracy and discovered the strong correlation with correlation coefficient of >0.9 between shift position data and normal position data.

Understanding the NMR properties and conformational behavior of indole vs. azaindole group in protoberberines: NICS and NCS analysis

NASA Astrophysics Data System (ADS)

Kadam, Shivaji S.; Toušek, Jaromír; Maier, Lukáš; Pipíška, Matej; Sklenář, Vladimír; Marek, Radek

2012-11-01

We report here the preparation and the structural investigation into a series of 8-(indol-1-yl)-7,8-dihydroprotoberberine derivatives derived from berberine, palmatine, and coptisine. Structures of these new compounds were characterized mainly by 2D NMR spectroscopy and the conformational behavior was investigated by using methods of density-functional theory (DFT). PBE0/6-311+G** calculated NMR chemical shifts for selected derivatives correlate excellently with the experimental NMR data and support the structural conclusions drawn from the NMR experiments. An interesting role of the nitrogen atom in position N7' of the indole moiety in 8-(7-azaindol-1-yl)-7,8-dihydroprotoberberines as compared to other 8-indolyl derivatives is investigated in detail. The experimentally observed trends in NMR chemical shifts are rationalized by DFT calculations and analysis based on the nucleus-independent chemical shifts (NICS) and natural localized molecular orbitals (NLMOs).

Nuclear magnetic resonance spectroscopy in the structure elucidation and biosynthesis of natural products

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

Meksuriyen, D.

1988-01-01

Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclearmore » multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of protonated and nonprotonated carbons, respectively. S. Staurosporeus was found to utilize endogenous and exogenous D- and L-isomers of trytophan in the production of staurosporine. The biosynthesis of staurosporine was examined by employing carbon-14, tritium, and carbon-13 labeled precursors.« less

Search for New and Better High Temperature Superconductors

DTIC Science & Technology

2014-03-30

agreement with experiment [23]. Importantly, their calculations demonstrated that the correlations shift oscillator strength in the real part of the...well as the insulating behavior can hardly be altered. They also discovered a new Fe pnictide compound with tetragonal FeAs stripes , CaFe4As3 [60...various (uncontrolled) heat treatments by application of very high current densities through the Cu layer. Our approach was not to try to replicate

Frequency-Modulation Correlation Spectrometer

NASA Technical Reports Server (NTRS)

Margolis, J. S.; Martonchik, J. V.

1985-01-01

New type of correlation spectrometer eliminates need to shift between two cells, one empty and one containing reference gas. Electrooptical phase modulator sinusoidally shift frequencies of sample transmission spectrum.

Pollinator shifts and the evolution of spur length in the moth-pollinated orchid Platanthera bifolia.

PubMed

Boberg, Elin; Alexandersson, Ronny; Jonsson, Magdalena; Maad, Johanne; Ågren, Jon; Nilsson, L Anders

2014-01-01

Plant-pollinator interactions are thought to have shaped much of floral evolution. Yet the relative importance of pollinator shifts and coevolutionary interactions for among-population variation in floral traits in animal-pollinated species is poorly known. This study examined the adaptive significance of spur length in the moth-pollinated orchid Platanthera bifolia. Geographical variation in the length of the floral spur of P. bifolia was documented in relation to variation in the pollinator fauna across Scandinavia, and a reciprocal translocation experiment was conducted in south-east Sweden between a long-spurred woodland population and a short-spurred grassland population. Spur length and pollinator fauna varied among regions and habitats, and spur length was positively correlated with the proboscis length of local pollinators. In the reciprocal translocation experiment, long-spurred woodland plants had higher pollination success than short-spurred grassland plants at the woodland site, while no significant difference was observed at the grassland site. The results are consistent with the hypothesis that optimal floral phenotype varies with the morphology of the local pollinators, and that the evolution of spur length in P. bifolia has been largely driven by pollinator shifts.

Pollinator shifts and the evolution of spur length in the moth-pollinated orchid Platanthera bifolia

PubMed Central

Boberg, Elin; Alexandersson, Ronny; Jonsson, Magdalena; Maad, Johanne; Ågren, Jon; Nilsson, L. Anders

2014-01-01

Background and Aims Plant–pollinator interactions are thought to have shaped much of floral evolution. Yet the relative importance of pollinator shifts and coevolutionary interactions for among-population variation in floral traits in animal-pollinated species is poorly known. This study examined the adaptive significance of spur length in the moth-pollinated orchid Platanthera bifolia. Methods Geographical variation in the length of the floral spur of P. bifolia was documented in relation to variation in the pollinator fauna across Scandinavia, and a reciprocal translocation experiment was conducted in south-east Sweden between a long-spurred woodland population and a short-spurred grassland population. Key Results Spur length and pollinator fauna varied among regions and habitats, and spur length was positively correlated with the proboscis length of local pollinators. In the reciprocal translocation experiment, long-spurred woodland plants had higher pollination success than short-spurred grassland plants at the woodland site, while no significant difference was observed at the grassland site. Conclusions The results are consistent with the hypothesis that optimal floral phenotype varies with the morphology of the local pollinators, and that the evolution of spur length in P. bifolia has been largely driven by pollinator shifts. PMID:24169591

Dimension-Based Statistical Learning Affects Both Speech Perception and Production.

PubMed

Lehet, Matthew; Holt, Lori L

2017-04-01

Multiple acoustic dimensions signal speech categories. However, dimensions vary in their informativeness; some are more diagnostic of category membership than others. Speech categorization reflects these dimensional regularities such that diagnostic dimensions carry more "perceptual weight" and more effectively signal category membership to native listeners. Yet perceptual weights are malleable. When short-term experience deviates from long-term language norms, such as in a foreign accent, the perceptual weight of acoustic dimensions in signaling speech category membership rapidly adjusts. The present study investigated whether rapid adjustments in listeners' perceptual weights in response to speech that deviates from the norms also affects listeners' own speech productions. In a word recognition task, the correlation between two acoustic dimensions signaling consonant categories, fundamental frequency (F0) and voice onset time (VOT), matched the correlation typical of English, and then shifted to an "artificial accent" that reversed the relationship, and then shifted back. Brief, incidental exposure to the artificial accent caused participants to down-weight perceptual reliance on F0, consistent with previous research. Throughout the task, participants were intermittently prompted with pictures to produce these same words. In the block in which listeners heard the artificial accent with a reversed F0 × VOT correlation, F0 was a less robust cue to voicing in listeners' own speech productions. The statistical regularities of short-term speech input affect both speech perception and production, as evidenced via shifts in how acoustic dimensions are weighted. Copyright © 2016 Cognitive Science Society, Inc.

Dimension-based statistical learning affects both speech perception and production

PubMed Central

Lehet, Matthew; Holt, Lori L.

2016-01-01

Multiple acoustic dimensions signal speech categories. However, dimensions vary in their informativeness; some are more diagnostic of category membership than others. Speech categorization reflects these dimensional regularities such that diagnostic dimensions carry more “perceptual weight” and more effectively signal category membership to native listeners. Yet, perceptual weights are malleable. When short-term experience deviates from long-term language norms, such as in a foreign accent, the perceptual weight of acoustic dimensions in signaling speech category membership rapidly adjusts. The present study investigated whether rapid adjustments in listeners’ perceptual weights in response to speech that deviates from the norms also affects listeners’ own speech productions. In a word recognition task, the correlation between two acoustic dimensions signaling consonant categories, fundamental frequency (F0) and voice onset time (VOT), matched the correlation typical of English, then shifted to an “artificial accent” that reversed the relationship, and then shifted back. Brief, incidental exposure to the artificial accent caused participants to down-weight perceptual reliance on F0, consistent with previous research. Throughout the task, participants were intermittently prompted with pictures to produce these same words. In the block in which listeners heard the artificial accent with a reversed F0 x VOT correlation, F0 was a less robust cue to voicing in listeners’ own speech productions. The statistical regularities of short-term speech input affect both speech perception and production, as evidenced via shifts in how acoustic dimensions are weighted. PMID:27666146

Shift in community structure in an early-successional Mediterranean shrubland driven by long-term experimental warming and drought and natural extreme droughts.

PubMed

Liu, Daijun; Estiarte, Marc; Ogaya, Romà; Yang, Xiaohong; Peñuelas, Josep

2017-10-01

Global warming and recurring drought are expected to accelerate water limitation for plant communities in semiarid Mediterranean ecosystems and produce directional shifts in structure and composition that are not easily detected, and supporting evidence is scarce. We conducted a long-term (17 years) nocturnal-warming (+0.6°C) and drought (-40% rainfall) experiments in an early-successional Mediterranean shrubland to study the changes in community structure and composition, contrasting functional groups and dominant species, and the superimposed effects of natural extreme drought. Species richness decreased in both the warming and drought treatments. Responses to the moderate warming were associated with decreases in herb abundance, and responses to the drought were associated with decreases in both herb and shrub abundances. The drought also significantly decreased community diversity and evenness. Changes in abundance differed between herbs (decreases) and shrubs (increases or no changes). Both warming and drought, especially drought, increased the relative species richness and abundance of shrubs, favoring the establishment of shrubs. Both warming and drought produced significant shifts in plant community composition. Experimental warming shifted the community composition from Erica multiflora toward Rosmarinus officinalis, and drought consistently shifted the composition toward Globularia alypum. The responses in biodiversity (e.g., community biodiversity, changes of functional groups and compositional shifts) were also strongly correlated with atmospheric drought (SPEI) in winter-spring and/or summer, indicating sensitivity to water limitation in this early-successional Mediterranean ecosystem, especially to natural extreme droughts. Our results suggest that the shifts in species assembles and community diversity and composition are accelerated by the long-term nocturnal-warming and drought, combined with natural severe droughts, and that the magnitude of the impacts of climate change is also correlated with the successional status of ecosystem. The results thus highlight the necessity for assessing the impacts on ecosystemic functioning and services and developing effective measures for conserving biodiversity. © 2017 John Wiley & Sons Ltd.

First principles NMR calculations of phenylphosphinic acid C 6H 5HPO(OH): Assignments, orientation of tensors by local field experiments and effect of molecular motion

NASA Astrophysics Data System (ADS)

Gervais, C.; Coelho, C.; Azaı¨s, T.; Maquet, J.; Laurent, G.; Pourpoint, F.; Bonhomme, C.; Florian, P.; Alonso, B.; Guerrero, G.; Mutin, P. H.; Mauri, F.

2007-07-01

The complete set of NMR parameters for 17O enriched phenylphosphinic acid C 6H 5HP ∗O( ∗OH) is calculated from first principles by using the Gauge Including Projected Augmented Wave (GIPAW) approach [C.J. Pickard, F. Mauri, All-electron magnetic response with pseudopotentials: NMR chemical shifts, Phys. Rev. B 63 (2001) 245101/1-245101/13]. The analysis goes beyond the successful assignment of the spectra for all nuclei ( 1H, 13C, 17O, 31P), as: (i) the 1H CSA (chemical shift anisotropy) tensors (magnitude and orientation) have been interpreted in terms of H bonding and internuclear distances. (ii) CSA/dipolar local field correlation experiments have allowed the orientation of the direct P-H bond direction in the 31P CSA tensor to be determined. Experimental and calculated data were compared. (iii) The overestimation of the calculated 31P CSA has been explained by local molecular reorientation and confirmed by low temperature static 1H → 31P CP experiments.

Robust alignment of chromatograms by statistically analyzing the shifts matrix generated by moving window fast Fourier transform cross-correlation.

PubMed

Zhang, Mingjing; Wen, Ming; Zhang, Zhi-Min; Lu, Hongmei; Liang, Yizeng; Zhan, Dejian

2015-03-01

Retention time shift is one of the most challenging problems during the preprocessing of massive chromatographic datasets. Here, an improved version of the moving window fast Fourier transform cross-correlation algorithm is presented to perform nonlinear and robust alignment of chromatograms by analyzing the shifts matrix generated by moving window procedure. The shifts matrix in retention time can be estimated by fast Fourier transform cross-correlation with a moving window procedure. The refined shift of each scan point can be obtained by calculating the mode of corresponding column of the shifts matrix. This version is simple, but more effective and robust than the previously published moving window fast Fourier transform cross-correlation method. It can handle nonlinear retention time shift robustly if proper window size has been selected. The window size is the only one parameter needed to adjust and optimize. The properties of the proposed method are investigated by comparison with the previous moving window fast Fourier transform cross-correlation and recursive alignment by fast Fourier transform using chromatographic datasets. The pattern recognition results of a gas chromatography mass spectrometry dataset of metabolic syndrome can be improved significantly after preprocessing by this method. Furthermore, the proposed method is available as an open source package at https://github.com/zmzhang/MWFFT2. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Workplace Violence against Health Care Workers in North Chinese Hospitals: A Cross-Sectional Survey.

PubMed

Sun, Peihang; Zhang, Xue; Sun, Yihua; Ma, Hongkun; Jiao, Mingli; Xing, Kai; Kang, Zheng; Ning, Ning; Fu, Yapeng; Wu, Qunhong; Yin, Mei

2017-01-19

This research aimed to determine the prevalence of workplace violence (WPV) against healthcare workers, explore the frequency distribution of violence in different occupational groups, and determine which healthcare occupation suffers from WPV most frequently. Furthermore, the current study aimed to compare risk factors affecting different types of WPV in Chinese hospitals. A cross-sectional design was utilized. A total of 1899 healthcare workers from Heilongjiang, a province in Northeastern China, completed the questionnaire. Of the respondents, 83.3% reported exposure to workplace violence, and 68.9% reported non-physical violence. Gender, education, shift work, anxiety level, and occupation were significantly correlated with physical violence ( p < 0.05 for all correlations). Additionally, age, professional title, and occupation were correlated with non-physical violence, which critically affected doctors. Thus, gender, age, profession, anxiety, and shift work were predictive of workplace violence toward healthcare workers. Doctors appeared to experience non-physical workplace violence with particularly higher frequency when compared to nurses and other workers in hospitals. For healthcare workers, interventions aimed at WPV reduction should be enacted according to the types of violence, profession, and other factors underlying the various types of WPV in hospitals.

Workplace Violence against Health Care Workers in North Chinese Hospitals: A Cross-Sectional Survey

PubMed Central

Sun, Peihang; Zhang, Xue; Sun, Yihua; Ma, Hongkun; Jiao, Mingli; Xing, Kai; Kang, Zheng; Ning, Ning; Fu, Yapeng; Wu, Qunhong; Yin, Mei

2017-01-01

This research aimed to determine the prevalence of workplace violence (WPV) against healthcare workers, explore the frequency distribution of violence in different occupational groups, and determine which healthcare occupation suffers from WPV most frequently. Furthermore, the current study aimed to compare risk factors affecting different types of WPV in Chinese hospitals. A cross-sectional design was utilized. A total of 1899 healthcare workers from Heilongjiang, a province in Northeastern China, completed the questionnaire. Of the respondents, 83.3% reported exposure to workplace violence, and 68.9% reported non-physical violence. Gender, education, shift work, anxiety level, and occupation were significantly correlated with physical violence (p < 0.05 for all correlations). Additionally, age, professional title, and occupation were correlated with non-physical violence, which critically affected doctors. Thus, gender, age, profession, anxiety, and shift work were predictive of workplace violence toward healthcare workers. Doctors appeared to experience non-physical workplace violence with particularly higher frequency when compared to nurses and other workers in hospitals. For healthcare workers, interventions aimed at WPV reduction should be enacted according to the types of violence, profession, and other factors underlying the various types of WPV in hospitals. PMID:28106851

Volumetric blood flow via time-domain correlation: experimental verification.

PubMed

Embree, P M; O'Brien, W R

1990-01-01

A novel ultrasonic volumetric flow measurement method using time-domain correlation of consecutive pairs of echoes has been developed. An ultrasonic data acquisition system determined the time shift between a pair of range gated echoes by searching for the time shift with the maximum correlation between the RF sampled waveforms. Experiments with a 5-MHz transducer indicate that the standard deviation of the estimate of steady fluid velocity through 6-mm-diameter tubes is less than 10% of the mean. Experimentally, Sephadex (G-50; 20-80 mum dia.) particles in water and fresh porcine blood have been used as ultrasound scattering fluids. Two-dimensional (2-D) flow velocity can be estimated by slowly sweeping the ultrasonic beam across the blood vessel phantom. Volumetric flow through the vessel is estimated by integrating the 2-D flow velocity field and then is compared to hydrodynamic flow measurements to assess the overall experimental accuracy of the time-domain method. Flow rates from 50-500 ml/min have been estimated with an accuracy better than 10% under the idealized characteristics used in this study, which include straight circular thin-walled tubes, laminar axially-symmetric steady flow, and no intervening tissues.

Intentional gaze shift to neglected space: a compensatory strategy during recovery after unilateral spatial neglect.

PubMed

Takamura, Yusaku; Imanishi, Maho; Osaka, Madoka; Ohmatsu, Satoko; Tominaga, Takanori; Yamanaka, Kentaro; Morioka, Shu; Kawashima, Noritaka

2016-11-01

Unilateral spatial neglect is a common neurological syndrome following predominantly right hemispheric stroke. While most patients lack insight into their neglect behaviour and do not initiate compensatory behaviours in the early recovery phase, some patients recognize it and start to pay attention towards the neglected space. We aimed to characterize visual attention capacity in patients with unilateral spatial neglect with specific focus on cortical processes underlying compensatory gaze shift towards the neglected space during the recovery process. Based on the Behavioural Inattention Test score and presence or absence of experience of neglect in their daily life from stroke onset to the enrolment date, participants were divided into USN+‰‰+ (do not compensate, n = 15), USN+ (compensate, n = 10), and right hemisphere damage groups (no neglect, n = 24). The patients participated in eye pursuit-based choice reaction tasks and were asked to pursue one of five horizontally located circular objects flashed on a computer display. The task consisted of 25 trials with 4-s intervals, and the order of highlighted objects was randomly determined. From the recorded eye tracking data, eye movement onset and gaze shift were calculated. To elucidate the cortical mechanism underlying behavioural results, electroencephalagram activities were recorded in three USN+‰‰+, 13 USN+ and eight patients with right hemisphere damage. We found that while lower Behavioural Inattention Test scoring patients (USN+‰‰+) showed gaze shift to non-neglected space, some higher scoring patients (USN+) showed clear leftward gaze shift at visual stimuli onset. Moreover, we found a significant correlation between Behavioural Inattention Test score and gaze shift extent in the unilateral spatial neglect group (r = -0.62, P < 0.01). Electroencephalography data clearly demonstrated that the extent of increase in theta power in the frontal cortex strongly correlated with the leftward gaze shift extent in the USN+‰‰+ and USN+ groups. Our results revealed a compensatory strategy (continuous attention to the neglected space) and its neural correlates in patients with unilateral spatial neglect. In conclusion, patients with unilateral spatial neglect who recognized their own neglect behaviour intentionally focused on the neglected space as a compensatory strategy to avoid careless oversight. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Temperature dependent structural and dynamical properties of liquid Cu80Si20 binary alloy

NASA Astrophysics Data System (ADS)

Suthar, P. H.; Shah, A. K.; Gajjar, P. N.

2018-05-01

Ashcroft and Langreth binary structure factor have been used to study for pair correlation function and the study of dynamical variable: velocity auto correlation functions, power spectrum and mean square displacement calculated based on the static harmonic well approximation in liquid Cu80Si20 binary alloy at wide temperature range (1140K, 1175K, 1210K, 1250K, 1373K, 1473K.). The effective interaction for the binary alloy is computed by our well established local pseudopotential along with the exchange and correction functions Sarkar et al(S). The negative dip in velocity auto correlation decreases as the various temperature is increases. For power spectrum as temperature increases, the peak of power spectrum shifts toward lower ω. Good agreement with the experiment is observed for the pair correlation functions. Velocity auto correlation showing the transferability of the local pseudopotential used for metallic liquid environment in the case of copper based binary alloys.

Analyzing neural responses with vector fields.

PubMed

Buneo, Christopher A

2011-04-15

Analyzing changes in the shape and scale of single cell response fields is a key component of many neurophysiological studies. Typical analyses of shape change involve correlating firing rates between experimental conditions or "cross-correlating" single cell tuning curves by shifting them with respect to one another and correlating the overlapping data. Such shifting results in a loss of data, making interpretation of the resulting correlation coefficients problematic. The problem is particularly acute for two dimensional response fields, which require shifting along two axes. Here, an alternative method for quantifying response field shape and scale based on correlation of vector field representations is introduced. The merits and limitations of the methods are illustrated using both simulated and experimental data. It is shown that vector correlation provides more information on response field changes than scalar correlation without requiring field shifting and concomitant data loss. An extension of this vector field approach is also demonstrated which can be used to identify the manner in which experimental variables are encoded in studies of neural reference frames. Copyright © 2011 Elsevier B.V. All rights reserved.

On the correlation between bond-length change and vibrational frequency shift in halogen-bonded complexes

NASA Astrophysics Data System (ADS)

Wang, Weizhou; Zhang, Yu; Ji, Baoming; Tian, Anmin

2011-06-01

The C-Hal (Hal = Cl, Br, or I) bond-length change and the corresponding vibrational frequency shift of the C-Hal stretch upon the C-Hal ⋯Y (Y is the electron donor) halogen bond formation have been determined by using density functional theory computations. Plots of the C-Hal bond-length change versus the corresponding vibrational frequency shift of the C-Hal stretch all give straight lines. The coefficients of determination range from 0.94366 to 0.99219, showing that the correlation between the C-Hal bond-length change and the corresponding frequency shift is very good in the halogen-bonded complexes. The possible effects of vibrational coupling, computational method, and anharmonicity on the bond-length change-frequency shift correlation are discussed in detail.

Hypothesis testing for differentially correlated features.

PubMed

Sheng, Elisa; Witten, Daniela; Zhou, Xiao-Hua

2016-10-01

In a multivariate setting, we consider the task of identifying features whose correlations with the other features differ across conditions. Such correlation shifts may occur independently of mean shifts, or differences in the means of the individual features across conditions. Previous approaches for detecting correlation shifts consider features simultaneously, by computing a correlation-based test statistic for each feature. However, since correlations involve two features, such approaches do not lend themselves to identifying which feature is the culprit. In this article, we instead consider a serial testing approach, by comparing columns of the sample correlation matrix across two conditions, and removing one feature at a time. Our method provides a novel perspective and favorable empirical results compared with competing approaches. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of shallow-layer reverberation on measurement of teleseismic P-wave travel times for ocean bottom seismograph data

NASA Astrophysics Data System (ADS)

Obayashi, Masayuki; Ishihara, Yasushi; Suetsugu, Daisuke

2017-03-01

We conducted synthetic experiments to evaluate the effects of shallow-layer reverberation in oceanic regions on P-wave travel times measured by waveform cross-correlation. Time shift due to waveform distortion by the reverberation was estimated as a function of period. Reverberations in the crystalline crust advance the P-waves by a frequency-independent time shift of about 0.3 s in oceans. Sediment does not affect the time shifts in the mid-ocean regions, but effects as large as -0.8 s or more occur where sediment thickness is greater than 600 m for periods longer than 15 s. The water layer causes time delays (+0.3 s) in the relatively shallow (<3500 m) water region for periods longer than 20 s. The time shift may influence mantle images obtained if the reverberation effects are not accounted for in seismic tomography. We propose a simple method to correct relative P-wave travel times at two sites for shallow-layer reverberation by the cross-convolution of the crustal responses at the two sites. [Figure not available: see fulltext. Caption: .

Sex differences in the neural correlates of affective experience

PubMed Central

Moriguchi, Yoshiya; Touroutoglou, Alexandra; Dickerson, Bradford C.

2014-01-01

People believe that women are more emotionally intense than men, but the scientific evidence is equivocal. In this study, we tested the novel hypothesis that men and women differ in the neural correlates of affective experience, rather than in the intensity of neural activity, with women being more internally (interoceptively) focused and men being more externally (visually) focused. Adult men (n = 17) and women (n = 17) completed a functional magnetic resonance imaging study while viewing affectively potent images and rating their moment-to-moment feelings of subjective arousal. We found that men and women do not differ overall in their intensity of moment-to-moment affective experiences when viewing evocative images, but instead, as predicted, women showed a greater association between the momentary arousal ratings and neural responses in the anterior insula cortex, which represents bodily sensations, whereas men showed stronger correlations between their momentary arousal ratings and neural responses in the visual cortex. Men also showed enhanced functional connectivity between the dorsal anterior insula cortex and the dorsal anterior cingulate cortex, which constitutes the circuitry involved with regulating shifts of attention to the world. These results demonstrate that the same affective experience is realized differently in different people, such that women’s feelings are relatively more self-focused, whereas men’s feelings are relatively more world-focused. PMID:23596188

Fatal accidents following changes in daylight savings time: the American experience.

PubMed

Varughese; Allen

2001-01-01

Objective: This study examines specific hypotheses that both sleep loss and behavioral changes occurring with the time shifts for Daylight Savings Time (DST) significantly effect the number of fatal traffic accidents in the United States of America.Background: It has been reported that there is a significant increase in the number of automobile accidents in the spring shift to DST due to the loss of 1 h of sleep. But the extra hour gained at night with the shift from DST in the fall has been variably reported to be associated with increases and decreases in the number of automobile accidents which may reflect either behavioral anticipation with an extended late night prior to the change or the benefit of extra sleep after the change.Methods: Data from 21 years of United States' fatal automobile accidents were gathered. The mean number of accidents on the days at the time of the shifts (Saturday, Sunday and Monday) was compared to the average of the corresponding mean number of accidents on the matching day of the weeks preceding and following the shift. This was repeated for each DST shift. The number of accidents for a particular shift was also correlated with the year of the accidents.Results: There was a significant increase in accidents for the Monday immediately following the spring shift to DST (t=1.92, P=0.034). There was also a significant increase in number of accidents on the Sunday of the fall shift from DST (P<0.002). No significant changes were observed for the other days. A significant negative correlation with the year was found between the number of accidents on the Saturdays and Sundays but not Mondays.Conclusions: The sleep deprivation on the Monday following shift to DST in the spring results in a small increase in fatal accidents. The behavioral adaptation anticipating the longer day on Sunday of the shift from DST in the fall leads to an increased number of accidents suggesting an increase in late night (early Sunday morning) driving when traffic related fatalities are high possibly related to alcohol consumption and driving while sleepy. Public health educators should probably consider issuing warnings both about the effects of sleep loss in the spring shift and possible behaviors such as staying out later, particularly when consuming alcohol in the fall shift. Sleep clinicians should be aware that health consequences from forced changes in the circadian patterns resulting from DST come not only from physiological adjustments but also from behavioral responses to forced circadian changes.

Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer.

PubMed

Hanni, Matti; Lantto, Perttu; Ilias, Miroslav; Jensen, Hans Jorgen Aagaard; Vaara, Juha

2007-10-28

Relativistic effects on the (129)Xe nuclear magnetic resonance shielding and (131)Xe nuclear quadrupole coupling (NQC) tensors are examined in the weakly bound Xe(2) system at different levels of theory including the relativistic four-component Dirac-Hartree-Fock (DHF) method. The intermolecular interaction-induced binary chemical shift delta, the anisotropy of the shielding tensor Deltasigma, and the NQC constant along the internuclear axis chi( parallel) are calculated as a function of the internuclear distance. DHF shielding calculations are carried out using gauge-including atomic orbitals. For comparison, the full leading-order one-electron Breit-Pauli perturbation theory (BPPT) is applied using a common gauge origin. Electron correlation effects are studied at the nonrelativistic (NR) coupled-cluster singles and doubles with perturbational triples [CCSD(T)] level of theory. The fully relativistic second-order Moller-Plesset many-body perturbation (DMP2) theory is used to examine the cross coupling between correlation and relativity on NQC. The same is investigated for delta and Deltasigma by BPPT with a density functional theory model. A semiquantitative agreement between the BPPT and DHF binary property curves is obtained for delta and Deltasigma in Xe(2). For these properties, the currently most complete theoretical description is obtained by a piecewise approximation where the uncorrelated relativistic DHF results obtained close to the basis-set limit are corrected, on the one hand, for NR correlation effects and, on the other hand, for the BPPT-based cross coupling of relativity and correlation. For chi( parallel), the fully relativistic DMP2 results obtain a correction for NR correlation effects beyond MP2. The computed temperature dependence of the second virial coefficient of the (129)Xe nuclear shielding is compared to experiment in Xe gas. Our best results, obtained with the piecewise approximation for the binary chemical shift combined with the previously published state of the art theoretical potential energy curve for Xe(2), are in excellent agreement with the experiment for the first time.

The fluid events model: Predicting continuous task action change.

PubMed

Radvansky, Gabriel A; D'Mello, Sidney; Abbott, Robert G; Morgan, Brent; Fike, Karl; Tamplin, Andrea K

2015-01-01

The fluid events model is a behavioural model aimed at predicting the likelihood that people will change their actions in ongoing, interactive events. From this view, not only are people responding to aspects of the environment, but they are also basing responses on prior experiences. The fluid events model is an attempt to predict the likelihood that people will shift the type of actions taken within an event on a trial-by-trial basis, taking into account both event structure and experience-based factors. The event-structure factors are: (a) changes in event structure, (b) suitability of the current action to the event, and (c) time on task. The experience-based factors are: (a) whether a person has recently shifted actions, (b) how often a person has shifted actions, (c) whether there has been a dip in performance, and (d) a person's propensity to switch actions within the current task. The model was assessed using data from a series of tasks in which a person was producing responses to events. These were two stimulus-driven figure-drawing studies, a conceptually driven decision-making study, and a probability matching study using a standard laboratory task. This analysis predicted trial-by-trial action switching in a person-independent manner with an average accuracy of 70%, which reflects a 34% improvement above chance. In addition, correlations between overall switch rates and actual switch rates were remarkably high (mean r = .98). The experience-based factors played a more major role than the event-structure factors, but this might be attributable to the nature of the tasks.

Spatiotemporal patterns of duck nest density and predation risk: a multi-scale analysis of 18 years and more than 10,000 nests

USGS Publications Warehouse

Ringelman, Kevin M.; Eadie, John M.; Ackerman, Joshua T.; Sih, Andrew; Loughman, Daniel L.; Yarris, Gregory S.; Oldenburger, Shaun L.; McLandress, M. Robert

2017-01-01

Many avian species are behaviorally-plastic in selecting nest sites, and may shift to new locations or habitats following an unsuccessful breeding attempt. If there is predictable spatial variation in predation risk, the process of many individuals using prior experience to adaptively change nest sites may scale up to create shifting patterns of nest density at a population level. We used 18 years of waterfowl nesting data to assess whether there were areas of consistently high or low predation risk, and whether low-risk areas increased, and high-risk areas decreased in nest density the following year. We created kernel density maps of successful and unsuccessful nests in consecutive years and found no correlation in predation risk and no evidence for adaptive shifts, although nest density was correlated between years. We also examined between-year correlations in nest density and nest success at three smaller spatial scales: individual nesting fields (10–28 ha), 16-ha grid cells and 4-ha grid cells. Here, results were similar across all scales: we found no evidence for year-to-year correlation in nest success but found strong evidence that nest density was correlated between years, and areas of high nest success increased in nest density the following year. Prior research in this system has demonstrated that areas of high nest density have higher nest success, and taken together, our results suggest that ducks may adaptively select nest sites based on the local density of conspecifics, rather than the physical location of last year's nest. In unpredictable environments, current cues, such as the presence of active conspecific nests, may be especially useful in selecting nest sites. The cues birds use to select breeding locations and successfully avoid predators deserve continued attention, especially in systems of conservation concern.

New graduate nurses adaptation to shift work: can we help?

PubMed

West, Sandra H; Ahern, Maureen; Byrnes, Margot; Kwanten, Lloyd

2007-01-01

Shift work's desynchronisation of physiologically determined circadian rhythms has a major effect on the psychobiology of every shift worker. It is also commonly perceived that the effects of shift work contribute to the current New Graduate Nurses (NGNs) attrition rate. NGNs must also adjust to work within the health care system as they adapt to shift work, but do the initial effects of shift work as experienced by NGNs get better with time? This study aimed to describe the adaptation of NGNs to shiftwork. Levels of general health, sleep, fatigue, circadian type, job satisfaction, levels of burnout and the coping processes of 150 final year undergraduate students were investigated in a questionnaire based longitudinal study conducted over their initial twelve months of clinical practice as NGNs. Correlational analysis indicates that whilst shift work initially seriously disturbs sleep and other variables associated with individual and situational differences some adaptation was evident by twelve months. Social dysfunction scores (GHQ28) remained significantly related with variables associated with burnout, job satisfaction, sleep disturbance and life disruption at the twelve month point. The presence of depression on pre-shift work scales was also significantly related to continuing experience of sleep disruption and increased levels of emotional exhaustion throughout the twelve month period. Further investigation is required to establish the effect of shiftwork on outcome measures such as levels of burnout and job satisfaction for NGNs. However, although it is possible that improved preparation for shift work may assist the adaptation of NGNs to shift work during their first year of practice it is clear that attention to the organisation of nursing shift work would also be timely.

Cosmic ray modulation

NASA Astrophysics Data System (ADS)

Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

2016-07-01

Propagation of cosmic rays to and inside the heliosphere, encounter an outward moving solar wind with cyclic magnetic field fluctuation and turbulence, causing convection and diffusion in the heliosphere. Cosmic ray counts from the ground ground-based neutron monitors at different cut of rigidity show intensity changes, which are anti-correlated with sunspot numbers. They also lose energy as they propagate towards the Earth and experience various types of modulations due to different solar activity indices. In this work, we study the first three harmonics of cosmic ray intensity on geo-magnetically quiet days over the period 1965-2014 for Beijing, Moscow and Tokyo neutron monitoring stations located at different cut off rigidity. The amplitude of first harmonic remains high for low cutoff rigidity as compared to high cutoff rigidity on quiet days. The diurnal amplitude significantly decreases during solar activity minimum years. The diurnal time of maximum significantly shifts to an earlier time as compared to the corotational direction having different cutoff rigidities. The time of maximum for first harmonic significantly shifts towards later hours and for second harmonic it shifts towards earlier hours at low cutoff rigidity station as compared to the high cut off rigidity station on quiet days. The amplitude of second/third harmonics shows a good positive correlation with solar wind velocity, while the others (i.e. amplitude and phase) have no significant correlation on quiet days. The amplitude and direction of the anisotropy on quiet days does not show any significant dependence on high-speed solar wind streams for these neutron monitoring stations of different cutoff rigidity threshold. Keywords: cosmic ray, cut off rigidity, quiet days, harmonics, amplitude, phase.

Construction and Initial Validation of the Multiracial Experiences Measure (MEM)

PubMed Central

Yoo, Hyung Chol; Jackson, Kelly; Guevarra, Rudy P.; Miller, Matthew J.; Harrington, Blair

2015-01-01

This article describes the development and validation of the Multiracial Experiences Measure (MEM): a new measure that assesses uniquely racialized risks and resiliencies experienced by individuals of mixed racial heritage. Across two studies, there was evidence for the validation of the 25-item MEM with 5 subscales including Shifting Expressions, Perceived Racial Ambiguity, Creating Third Space, Multicultural Engagement, and Multiracial Discrimination. The 5-subscale structure of the MEM was supported by a combination of exploratory and confirmatory factor analyses. Evidence of criterion-related validity was partially supported with MEM subscales correlating with measures of racial diversity in one’s social network, color-blind racial attitude, psychological distress, and identity conflict. Evidence of discriminant validity was supported with MEM subscales not correlating with impression management. Implications for future research and suggestions for utilization of the MEM in clinical practice with multiracial adults are discussed. PMID:26460977

Construction and initial validation of the Multiracial Experiences Measure (MEM).

PubMed

Yoo, Hyung Chol; Jackson, Kelly F; Guevarra, Rudy P; Miller, Matthew J; Harrington, Blair

2016-03-01

This article describes the development and validation of the Multiracial Experiences Measure (MEM): a new measure that assesses uniquely racialized risks and resiliencies experienced by individuals of mixed racial heritage. Across 2 studies, there was evidence for the validation of the 25-item MEM with 5 subscales including Shifting Expressions, Perceived Racial Ambiguity, Creating Third Space, Multicultural Engagement, and Multiracial Discrimination. The 5-subscale structure of the MEM was supported by a combination of exploratory and confirmatory factor analyses. Evidence of criterion-related validity was partially supported with MEM subscales correlating with measures of racial diversity in one's social network, color-blind racial attitude, psychological distress, and identity conflict. Evidence of discriminant validity was supported with MEM subscales not correlating with impression management. Implications for future research and suggestions for utilization of the MEM in clinical practice with multiracial adults are discussed. (c) 2016 APA, all rights reserved).

HN(α/β-COCA-J) Experiment for Measurement of 1JC‧Cα Couplings from Two-Dimensional [15N, 1H] Correlation Spectrum

NASA Astrophysics Data System (ADS)

Permi, Perttu; Sorsa, Tia; Kilpeläinen, Ilkka; Annila, Arto

1999-11-01

Anew method for measurement of one-bond 13C‧-13Cα scalar and dipolar couplings from a two-dimensional [15N, 1H] correlation spectrum is presented. The experiment is based on multiple-quantum coherence, which is created between nitrogen and carbonyl carbon for simultaneous evolution of 15N chemical shift and coupling between 13C‧ and 13Cα. Optional subspectral editing is provided by the spin-state-selective filters. The residual dipolar dipolar contribution to the 13C‧-13Cα coupling can be measured from these simplified [15N, 1H]-HSQC-like spectra. In this way, without explicit knowledge of carbon assignments, conformational changes of proteins dissolved in dilute liquid crystals can be probed conveniently, e.g., in structure activity relationship by NMR studies. The method is demonstrated with human cardiac troponin C.

Citronellal assumes a folded conformation in solution due to dispersion interactions: A joint NMR-DFT analysis

NASA Astrophysics Data System (ADS)

Nardini, Viviani; Dias, Luis Gustavo; Palaretti, Vinicius; da Silva, Gil Valdo José

2018-04-01

Citronellal, an acyclic monoterpenoid, is a small molecule suitable for systematic scanning of its conformational geometric parameters in solution or in the gas phase. We have studied the conformational distribution of citronellal by correlating its structure and theoretical chemical shifts with nuclear magnetic resonance data. Interestingly, folded conformations were the most relevant, as confirmed by NOE experiments. We concluded that the conformational distribution is due to intramolecular dispersion interactions.

Drifty shifty deluxe.m

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

Josh Sugar, Dave Robinson

2014-01-24

Performs a cross-correlation calculation to align images. This is particularly useful for aligning frames of a movie so that an object of interest does not spatially drift. For in situ microscopy experiments. Movies are collected where an object changes with time. At the same time, the object usually drifts too. This shifts the movie frames so that the object is aligned from frame to frame. Then it is easy to see the object changes without the added complication of it moving too.

The Correlation Between Cognitive and Movement Shifting and Brain Activity in Children With ADHD.

PubMed

Kang, Kyoung Doo; Han, Doug Hyun; Kim, Sun Mi; Bae, Sujin; Renshaw, Perry F

2018-05-01

We assessed the correlation between the deficits of cognition, movement, and brain activity in children with Attention Deficit Hyperactvity Disorder (ADHD). We recruited 15 children with ADHD and 15 age- and sex-matched healthy control participants. Clinical symptoms, cognitive shifting, movement shifting, and brain activity were assessed using the Korean ADHD Rating Scale, the Wisconsin Card Sorting Test (WCST), the 7- and 14-ring drill test with hop jumps (7 HJ and 14 HJ), and 3.0 Tesla functional magnetic resonance imaging scanner, respectively. ADHD children showed an increased distance traveled and decreased speed on the 14 HJ task. In response to the WCST task, ADHD children showed decreased activation within right gyrus. Total distance on the 14 HJ task was negatively correlated with the mean β value of Cluster 2 in ADHD children. These results suggested that children with ADHD showed difficulty with attention shifting as well as with movement shifting.

Correlations between the resonant frequency shifts and the thermodynamic quantities for the α-β transition in quartz

NASA Astrophysics Data System (ADS)

Lider, M. C.; Yurtseven, H.

2018-05-01

The resonant frequency shifts are related to the thermodynamic quantities (compressibility, order parameter and susceptibility) for the α-β transition in quartz. The experimental data for the resonant frequencies and the bulk modulus from the literature are used for those correlations. By calculating the order parameter from the mean field theory, correlation between the resonant frequencies of various modes and the order parameter is examined according to the quasi-harmonic phonon theory for the α-β transition in quartz. Also, correlation between the bulk modulus in relation to the resonant frequency shifts and the order parameter susceptibility is constructed for the α-β transition in this crystalline system.

Assessment of Thematic Mapper Band-to-band Registration by the Block Correlation Method

NASA Technical Reports Server (NTRS)

Card, D. H.; Wrigley, R. C.; Mertz, F. C.; Hall, J. R.

1984-01-01

The design of the Thematic Mapper (TM) multispectral radiometer makes it susceptible to band-to-band misregistration. To estimate band-to-band misregistration a block correlation method is employed. This method is chosen over other possible techniques (band differencing and flickering) because quantitative results are produced. The method correlates rectangular blocks of pixels from one band against blocks centered on identical pixels from a second band. The block pairs are shifted in pixel increments both vertically and horizontally with respect to each other and the correlation coefficient for each shift position is computed. The displacement corresponding to the maximum correlation is taken as the best estimate of registration error for each block pair. Subpixel shifts are estimated by a bi-quadratic interpolation of the correlation values surrounding the maximum correlation. To obtain statistical summaries for each band combination post processing of the block correlation results performed. The method results in estimates of registration error that are consistent with expectations.

Plasma /Na+/, /Ca++/, and volume shifts and thermoregulation during exercise in man

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Convertino, V. A.; Stremel, R. W.; Bernauer, E. M.; Adams, W. C.; Vignau, S. R.; Brock, P. J.

1977-01-01

Graded-exercise experiments are conducted on six trained male runners (19-23 yr) subjected to ergometer exercise in a program consisting of 30-min resting control period, 60 min of rest or exercise at work loads that resulted in a maximal oxygen uptake equivalent to 6% (resting), 23%, 43%, and 62% of maximal oxygen uptake, followed by 30 min of recovery. The parameters measured and discussed are rectal temperature (T-re), skin temperatures at different spots, maximal oxygen uptake, plasma volume (PV), and various plasma electrolyte and protein concentrations. The objectives are to determine whether the increased T-re during progressively greater work loads are related to plasma sodium ion and calcium ion concentrations, as well as to evaluate the influence of PV shifts on the electrolyte and osmotic concentrations. The results suggest that the shift (loss) in PV accounts for the increases in the plasma constituent concentrations that result in significant correlations with T-re.

Pressure-Induced Structural Evolution and Band Gap Shifts of Organometal Halide Perovskite-Based Methylammonium Lead Chloride.

PubMed

Wang, Lingrui; Wang, Kai; Xiao, Guanjun; Zeng, Qiaoshi; Zou, Bo

2016-12-15

Organometal halide perovskites are promising materials for optoelectronic devices. Further development of these devices requires a deep understanding of their fundamental structure-property relationships. The effect of pressure on the structural evolution and band gap shifts of methylammonium lead chloride (MAPbCl 3 ) was investigated systematically. Synchrotron X-ray diffraction and Raman experiments provided structural information on the shrinkage, tilting distortion, and amorphization of the primitive cubic unit cell. In situ high pressure optical absorption and photoluminescence spectra manifested that the band gap of MAPbCl 3 could be fine-tuned to the ultraviolet region by pressure. The optical changes are correlated with pressure-induced structural evolution of MAPbCl 3 , as evidenced by band gap shifts. Comparisons between Pb-hybrid perovskites and inorganic octahedra provided insights on the effects of halogens on pressure-induced transition sequences of these compounds. Our results improve the understanding of the structural and optical properties of organometal halide perovskites.

Localization length and intraband scattering of excitons in linear aggregates

NASA Astrophysics Data System (ADS)

Lemaistre, J. P.

1999-07-01

A theoretical model to describe the intraband scattering of excitons in linear aggregates of finite size which exhibit strong intermolecular interactions is presented. From the calculation of the aggregate eigenstates, the localization length of excitons is evaluated for various configurations featuring physical situations like trapping, edge effects, inclusion of diagonal and/or orientational disorders. The intraband scattering is studied by considering the exciton-phonon stochastic coupling induced by the thermal bath. This coupling creates local dynamical fluctuations in the site energies which are characterized by their amplitude ( Δ) and their correlation time ( τc). Expressions of scattering rates are provided and used in a Pauli master equation to calculate the time dependence of the eigenstates populations after initial excitation of the quasi exciton-band. It is shown that the time evolution of the lowest state population as well as the Stokes shift strongly depend on τc. Comparison of the theoretical results to time-resolved experiments performed on triaryl pyrylium salts allows us to interpret the observed Stokes shift and to derive an average value of the exciton-phonon correlation time.

How well do Radiologic Assessments of Truncal and Shoulder Balance Correlate With Cosmetic Assessment Indices in Lenke 1C Adolescent Idiopathic Scoliosis?

PubMed

Sharma, Shallu; Andersen, Thomas; Wu, Chunsen; Sun, Haolin; Wang, Yu; Hansen, Ebbe S; Bünger, Cody E

2016-10-01

A correlation study. The primary objective was to determine the correlation between radiologic and cosmetic indices of trunk and shoulder balance before and after scoliosis surgery in Lenke 1C adolescent idiopathic scoliosis and to determine whether postoperative trunk shift is affiliated with worsening of the patients' cosmesis. Achieving a symmetrical appearance with truncal and shoulder balance is of prime importance to adolescent idiopathic scoliosis patients and their surgeons. However, surgeons prefer radiographic indices rather than measures of patients' clinical appearance. If radiographic indices are to be considered accurate depictions of the patient's cosmesis, radiologic and cosmetic indices must necessarily exhibit high association. Radiographic and cosmetic indices of trunk and shoulder balance, along with posterior trunk symmetry index, were measured preoperatively and 3 months postoperatively in 33 Lenke 1C scoliosis patients. Pearson correlation analysis was performed. Paired t test was used to determine significant changes in radiographic and cosmetic indices after surgery. Independent-sample t test was used for all intergroup analyses in trunk shift and no-trunk-shift groups. Correlation coefficients between radiologic and cosmetic indices ranged between -0.63 and 0.70 with thoracic apical vertebra-central sacral vertical line (AV-CSVL) distance and first rib angle showing consistent correlations with cosmetic trunk and cosmetic shoulder balance indices. Trunk shift, a postoperative iatrogenic phenomenon, was seen in 19 (58%) patients. These patients had higher preoperative thoracic AV-CSVL translation, thoracic apical vertebra-first thoracic vertebra (AV-T1) translation, thoracic deformity correction rate, AV-T1 correction rates, and shorter fusions compared with the no-trunk-shift group. Posterior trunk symmetry index worsened in trunk shift group and improved significantly (-7.94 vs. 16.53) in no-trunk-shift group. Significant association (P=0.004) was seen between radiographic and cosmetic trunk shift. Radiographic indices can only minisculely (r≤0.7) reflect cosmetic deformity in Lenke 1C scoliosis, which emphasizes not only the vulnerability of overreliance on radiographic indices but also the vital importance of clinical cosmetic evaluations. In particular, cosmetic shoulder height and angle are not represented by radiographic indices. However, radiograph trunk shift was significantly associated with cosmetic trunk shift in cosmetic pictures.

Preliminary evaluation of the Environmental Research Institute of Michigan crop calendar shift algorithm for estimation of spring wheat development stage. [North Dakota, South Dakota, Montana, and Minnesota

NASA Technical Reports Server (NTRS)

Phinney, D. E. (Principal Investigator)

1980-01-01

An algorithm for estimating spectral crop calendar shifts of spring small grains was applied to 1978 spring wheat fields. The algorithm provides estimates of the date of peak spectral response by maximizing the cross correlation between a reference profile and the observed multitemporal pattern of Kauth-Thomas greenness for a field. A methodology was developed for estimation of crop development stage from the date of peak spectral response. Evaluation studies showed that the algorithm provided stable estimates with no geographical bias. Crop development stage estimates had a root mean square error near 10 days. The algorithm was recommended for comparative testing against other models which are candidates for use in AgRISTARS experiments.

Phylogeny-based comparative methods question the adaptive nature of sporophytic specializations in mosses.

PubMed

Huttunen, Sanna; Olsson, Sanna; Buchbender, Volker; Enroth, Johannes; Hedenäs, Lars; Quandt, Dietmar

2012-01-01

Adaptive evolution has often been proposed to explain correlations between habitats and certain phenotypes. In mosses, a high frequency of species with specialized sporophytic traits in exposed or epiphytic habitats was, already 100 years ago, suggested as due to adaptation. We tested this hypothesis by contrasting phylogenetic and morphological data from two moss families, Neckeraceae and Lembophyllaceae, both of which show parallel shifts to a specialized morphology and to exposed epiphytic or epilithic habitats. Phylogeny-based tests for correlated evolution revealed that evolution of four sporophytic traits is correlated with a habitat shift. For three of them, evolutionary rates of dual character-state changes suggest that habitat shifts appear prior to changes in morphology. This suggests that they could have evolved as adaptations to new habitats. Regarding the fourth correlated trait the specialized morphology had already evolved before the habitat shift. In addition, several other specialized "epiphytic" traits show no correlation with a habitat shift. Besides adaptive diversification, other processes thus also affect the match between phenotype and environment. Several potential factors such as complex genetic and developmental pathways yielding the same phenotypes, differences in strength of selection, or constraints in phenotypic evolution may lead to an inability of phylogeny-based comparative methods to detect potential adaptations.

Theoretical study of the hyperfine-interaction constants and the isotope-shift factors for the 3 s21S0-3 s 3 p 3,1P1o transitions in Al+

NASA Astrophysics Data System (ADS)

Zhang, Tingxian; Xie, Luyou; Li, Jiguang; Lu, Zehuang

2017-07-01

We calculated the magnetic dipole and the electric quadrupole hyperfine interaction constants of 3 s 3 p 3,1P1o states and the isotope shift, including mass and field shift, factors for transitions from these two states to the ground state 3 s 2 1S0 in Al+ ions using the multiconfiguration Dirac-Hartree-Fock method. The effects of the electron correlations and the Breit interaction on these physical quantities were investigated in detail based on the active space approach. It is found that the core-core and the higher order correlations are considerable for evaluating the uncertainties of the atomic parameters concerned. The uncertainties of the hyperfine interaction constants in this work are less than 1.6%. Although the isotope shift factors are highly sensitive to the electron correlations, reasonable uncertainties were obtained by exploring the effects of the electron correlations. Moreover, we found that the relativistic nuclear recoil corrections to the mass shift factors are very small and insensitive to the electron correlations for Al+. These atomic parameters present in this work are valuable for extracting the nuclear electric quadrupole moments and the mean-square charge radii of Al isotopes.

DISCO: Distance and Spectrum Correlation Optimization Alignment for Two Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry-based Metabolomics

PubMed Central

Wang, Bing; Fang, Aiqin; Heim, John; Bogdanov, Bogdan; Pugh, Scott; Libardoni, Mark; Zhang, Xiang

2010-01-01

A novel peak alignment algorithm using a distance and spectrum correlation optimization (DISCO) method has been developed for two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOF-MS) based metabolomics. This algorithm uses the output of the instrument control software, ChromaTOF, as its input data. It detects and merges multiple peak entries of the same metabolite into one peak entry in each input peak list. After a z-score transformation of metabolite retention times, DISCO selects landmark peaks from all samples based on both two-dimensional retention times and mass spectrum similarity of fragment ions measured by Pearson’s correlation coefficient. A local linear fitting method is employed in the original two-dimensional retention time space to correct retention time shifts. A progressive retention time map searching method is used to align metabolite peaks in all samples together based on optimization of the Euclidean distance and mass spectrum similarity. The effectiveness of the DISCO algorithm is demonstrated using data sets acquired under different experiment conditions and a spiked-in experiment. PMID:20476746

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

Xing, Y; Macq, B; Bondar, L

Purpose: To quantify the accuracy in predicting the Bragg peak position using simulated in-room measurements of prompt gamma (PG) emissions for realistic treatment error scenarios that combine several sources of errors. Methods: Prompt gamma measurements by a knife-edge slit camera were simulated using an experimentally validated analytical simulation tool. Simulations were performed, for 143 treatment error scenarios, on an anthropomorphic phantom and a pencil beam scanning plan for nasal cavity. Three types of errors were considered: translation along each axis, rotation around each axis, and CT-calibration errors with magnitude ranging respectively, between −3 and 3 mm, −5 and 5 degrees,more » and between −5 and +5%. We investigated the correlation between the Bragg peak (BP) shift and the horizontal shift of PG profiles. The shifts were calculated between the planned (reference) position and the position by the error scenario. The prediction error for one spot was calculated as the absolute difference between the PG profile shift and the BP shift. Results: The PG shift was significantly and strongly correlated with the BP shift for 92% of the cases (p<0.0001, Pearson correlation coefficient R>0.8). Moderate but significant correlations were obtained for all cases that considered only CT-calibration errors and for 1 case that combined translation and CT-errors (p<0.0001, R ranged between 0.61 and 0.8). The average prediction errors for the simulated scenarios ranged between 0.08±0.07 and 1.67±1.3 mm (grand mean 0.66±0.76 mm). The prediction error was moderately correlated with the value of the BP shift (p=0, R=0.64). For the simulated scenarios the average BP shift ranged between −8±6.5 mm and 3±1.1 mm. Scenarios that considered combinations of the largest treatment errors were associated with large BP shifts. Conclusion: Simulations of in-room measurements demonstrate that prompt gamma profiles provide reliable estimation of the Bragg peak position for complex error scenarios. Yafei Xing and Luiza Bondar are funded by BEWARE grants from the Walloon Region. The work presents simulations results for a prompt gamma camera prototype developed by IBA.« less

17O NMR studies on 4- and 4'-substituted chalcones and p-substituted β-nitrostyrenes

NASA Astrophysics Data System (ADS)

Boykin, D. W.; Baumstark, A. L.; Balakrishnan, P.; Perjéssy, A.; Hrnc˜iar, P.

The 17O NMR chemical shift data for 17O-enriched 4- and 4'-chalcones in toluene at 90°C and for p-substituted β-nitrostyrenes (natural abundance) in acetonitrile at 70°C are reported. The SCS (substituent chemical shift) range for the 4-chalcones p-CH 3O to p-NO 2 is 16.3 ppm; the range for the 4'-chalcones p-CH 3O to p-NO 2 is 32.4 ppm. The SCS range for the p-substituted-β-nitrostyrenes p-CH 3O to p-NO 2 is 13.2 ppm. The data for the three series gave good correlations with σ + constants, while the Dual Substitutent Parameter treatment only slightly improved the correlations using σ R+ constants. Plots of the 17O chemical shifts for both 4- and 4'-chalcones with 17O data for acetophenones and correlation of 17O chemical shift data for the β-nitrostyrenes with that of nitrobenzenes gave good correlations. Plots of the 17O data for all the three series with their respective functional group stretching frequencies gave fair correlations.

Further Evidence That Cannabis Moderates Familial Correlation of Psychosis-Related Experiences

PubMed Central

van Winkel, Ruud

2015-01-01

Background Familial correlations underlie heritability estimates of psychosis. If gene-environment interactions are important, familial correlation will vary as a function of environmental exposure. Methods Associations between sibling and parental schizotypy (n = 669 pairs, n = 1222 observations), and between sibling schizotypy and patient CAPE psychosis (n = 978 pairs, n = 1723 observations) were examined as a function of sibling cannabis use. This design is based on the prediction that in unaffected siblings who are not exposed, vulnerability for psychosis will remain latent, whereas in case of exposure, latent psychosis vulnerability may become expressed, at the level of schizotypal symptoms, causing the phenotypic correlation between relatives to become “visible” under the influence of cannabis. Results Siblings exposed to recent cannabis use resembled their patient-relative more closely in terms of positive schizotypy (urinalysis(+):B = 0.30, P<.001; urinalysis(-):B = 0.10, p<0.001; p-interaction = 0.0135). Similarly, the familial correlation in positive schizotypy between parent and sibling was significantly greater in siblings recently exposed to cannabis (urinalysis(+):B = 0.78, P<.001; urinalysis(-):B = 0.43, p<0.001; p interaction = 0.0017). Results were comparable when using lifetime cannabis frequency of use as exposure instead of recent use. Parental schizotypy did not predict cannabis use in the healthy sibling, nor in the patient. Similarly, parental cannabis use was not associated with level of schizotypy in the sibling, nor with psychotic symptoms in the patient, making gene-environment correlation unlikely. Conclusion Familial correlation of psychosis-related experiences varies considerably as a function of exposure to cannabis, confirming the importance of gene-cannabis interaction in shifts of expression of psychosis-related experiences. PMID:26384217

Win-stay and win-shift lever-press strategies in an appetitively reinforced task for rats.

PubMed

Reed, Phil

2016-12-01

Two experiments examined acquisition of win-stay, win-shift, lose-stay, and lose-shift rules by which hungry rats could earn food reinforcement. In Experiment 1, two groups of rats were trained in a two-lever operant task that required them to follow either a win-stay/lose-shift or a win-shift/lose-stay contingency. The rates of acquisition of the individual rules within each contingency differed: lose-shift and lose-stay rules were acquired faster than win-stay and win-shift rules. Contrary to a number of previous reports, the win-shift rule was acquired less rapidly than any of the other rules. In Experiment 2, the four rules were taught separately, but subjects still acquired the win-shift rule more slowly than any of the other rules.

Randic and Schultz molecular topological indices and their correlation with some X-ray absorption parameters

NASA Astrophysics Data System (ADS)

Khatri, Sunil; Kekre, Pravin A.; Mishra, Ashutosh

2016-10-01

The properties of a molecular system are affected by the topology of molecule. Therefore many studies have been made where the various physic-chemical properties are correlated with the topological indices. These studies have shown a very good correlation demonstrating the utility of the graph theoretical approach. It is, therefore, very natural to expect that the various physical properties obtained by the X-ray absorption spectra may also show correlation with the topological indices. Some complexes were used to establish correlation between topological indices and some X-ray absorption parameters like chemical shift. The chemical shift is on the higher energy side of the metal edge in these complexes. The result obtained in these studies shows that the topological indices of organic molecule acting as a legands can be used for estimating edge shift theoretically.

Students' educational experiences and interaction with residents on night shifts.

PubMed

Schiller, Jocelyn; Sokoloff, Max; Tendhar, Chosang; Schmidt, John; Christner, Jennifer

2017-08-01

The purpose of this mixed-methods study was to investigate whether increased night shifts for students on paediatric rotations had any negative impact on their overall quality of educational experiences in light of the implementation of duty-hour restrictions. Both quantitative and qualitative data were collected from 30 students on paediatric rotations during the academic year 2011/12. Students completed two questionnaires, one in response to their experiences during the day shifts and another in response to their experiences during the night shifts. Only 25 cases were retained for the final analyses. The non-parametric Wilcoxon signed-rank test was used to analyse the quantitative data, and constant comparative thematic analyses, as described by Creswell, were used to analyse the qualitative data. [Do] increased nights shifts for students … [have] any negative impact on their overall quality of educational experiences[?] RESULTS: The results indicated that students' perceived quality of experiences during the night shifts was greater, compared with their day shifts. Students reported having more time to socialise during the night shifts. They further reported that informal ways of learning, such as impromptu teaching and spontaneous discussions on clinical problems, were more beneficial, and these often occurred in abundance during the night shifts as opposed to the scheduled didactic teaching sessions that occur during the day shifts. This study documented many unanticipated benefits of night shifts. The feeling of cohesiveness of the night team deserves further exploration, as this can be linked to better performance outcomes. More consideration should be given to implementing night shifts as a regular feature of clerkships. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Intelligence, previous convictions and interrogative suggestibility: a path analysis of alleged false-confession cases.

PubMed

Sharrock, R; Gudjonsson, G H

1993-05-01

The main purpose of this study was to investigate the relationship between interrogative suggestibility and previous convictions among 108 defendants in criminal trials, using a path analysis technique. It was hypothesized that previous convictions, which may provide defendants with interrogative experiences, would correlate negatively with 'shift' as measured by the Gudjonsson Suggestibility Scale (Gudjonsson, 1984a), after intelligence and memory had been controlled for. The hypothesis was partially confirmed and the theoretical and practical implications of the findings are discussed.

Rapid jamming avoidance in biosonar.

PubMed

Gillam, Erin H; Ulanovsky, Nachum; McCracken, Gary F

2007-03-07

The sonar systems of bats and dolphins are in many ways superior to man-made sonar and radar systems, and considerable effort has been devoted to understanding the signal-processing strategies underlying these capabilities. A major feature determining the efficiency of sonar systems is the sensitivity to noise and jamming signals. Previous studies indicated that echolocating bats may adjust their signal structure to avoid jamming ('jamming avoidance response'; JAR). However, these studies relied on behavioural correlations and not controlled experiments. Here, we provide the first experimental evidence for JAR in bats. We presented bats (Tadarida brasiliensis) with 'playback stimuli' consisting of recorded echolocation calls at one of six frequencies. The bats exhibited a JAR by shifting their call frequency away from the presented playback frequency. When the approaching bats were challenged by an abrupt change in the playback stimulus, they responded by shifting their call frequencies upwards, away from the playback. Interestingly, even bats initially calling below the playback's frequency shifted their frequencies upwards, 'jumping' over the playback frequency. These spectral shifts in the bats' calls occurred often within less than 200 ms, in the first echolocation call emitted after the stimulus switch-suggesting that rapid jamming avoidance is important for the bat.

Visual Attention during Spatial Language Comprehension

PubMed Central

Burigo, Michele; Knoeferle, Pia

2015-01-01

Spatial terms such as “above”, “in front of”, and “on the left of” are all essential for describing the location of one object relative to another object in everyday communication. Apprehending such spatial relations involves relating linguistic to object representations by means of attention. This requires at least one attentional shift, and models such as the Attentional Vector Sum (AVS) predict the direction of that attention shift, from the sausage to the box for spatial utterances such as “The box is above the sausage”. To the extent that this prediction generalizes to overt gaze shifts, a listener’s visual attention should shift from the sausage to the box. However, listeners tend to rapidly look at referents in their order of mention and even anticipate them based on linguistic cues, a behavior that predicts a converse attentional shift from the box to the sausage. Four eye-tracking experiments assessed the role of overt attention in spatial language comprehension by examining to which extent visual attention is guided by words in the utterance and to which extent it also shifts “against the grain” of the unfolding sentence. The outcome suggests that comprehenders’ visual attention is predominantly guided by their interpretation of the spatial description. Visual shifts against the grain occurred only when comprehenders had some extra time, and their absence did not affect comprehension accuracy. However, the timing of this reverse gaze shift on a trial correlated with that trial’s verification time. Thus, while the timing of these gaze shifts is subtly related to the verification time, their presence is not necessary for successful verification of spatial relations. PMID:25607540

Organizational culture associated with provider satisfaction.

PubMed

Scammon, Debra L; Tabler, Jennifer; Brunisholz, Kimberly; Gren, Lisa H; Kim, Jaewhan; Tomoaia-Cotisel, Andrada; Day, Julie; Farrell, Timothy W; Waitzman, Norman J; Magill, Michael K

2014-01-01

Organizational culture is key to the successful implementation of major improvement strategies. Transformation to a patient-centered medical home (PCHM) is such an improvement strategy, requiring a shift from provider-centric care to team-based care. Because this shift may impact provider satisfaction, it is important to understand the relationship between provider satisfaction and organizational culture, specifically in the context of practices that have transformed to a PCMH model. This was a cross-sectional study of surveys conducted in 2011 among providers and staff in 10 primary care clinics implementing their version of a PCMH: Care by Design. Measures included the Organizational Culture Assessment Instrument and the American Medical Group Association provider satisfaction survey. Providers were most satisfied with quality of care (mean, 4.14; scale of 1-5) and interactions with patients (mean, 4.12) and were least satisfied with time spent working (mean, 3.47), paperwork (mean, 3.45), and compensation (mean, 3.35). Culture profiles differed across clinics, with family/clan and hierarchical cultures the most common. Significant correlations (P ≤ .05) between provider satisfaction and clinic culture archetypes included family/clan culture negatively correlated with administrative work; entrepreneurial culture positively correlated with the Time Spent Working dimension; market/rational culture positively correlated with how practices were facing economic and strategic challenges; and hierarchical culture negatively correlated with the Relationships with Staff and Resource dimensions. Provider satisfaction is an important metric for assessing experiences with features of a PCMH model. Identification of clinic-specific culture archetypes and archetype associations with provider satisfaction can help inform practice redesign. Attention to effective methods for changing organizational culture is recommended.

New experiments on the effect of clock shifts on homing in pigeons

NASA Technical Reports Server (NTRS)

Schmidt-Koenig, K.

1972-01-01

The effect of clock shifts as an experimental tool for predictably interfering with the homing ability of birds is discussed. Clock shifts introduce specific errors in the birds' sun azimuth compass, resulting in corresponding errors during initial orientation and possibly during orientation enroute. The effects of 6 hour and 12 hour clock shifts resulted in a 90 degree deviation and a 180 degree deviation from the initial orientation, respectively. The method for conducting the clock shift experiments and results obtained from previous experiments are described.

Mechanism of stimulated Hawking radiation in a laboratory Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Jacobson, Ted; Wang, Yi-Hsieh; Edwards, Mark; Clark, Charles W.

2017-01-01

Analog black/white hole pairs have been achieved in recent experiment by J. Steinhauer, using an elongated Bose-Einstein condensate. He reported observations of self-amplifying Hawking radiation, via a lasing mechanism operating between the black and white hole horizons. Through the simulations using the 1D Gross-Pitaevskii equation, we find that the experimental observations should be attributed not to the black hole laser effect, but rather to a growing zero-frequency bow wave, generated at the white-hole horizon. The relative motion of the black and white hole horizons produces a Doppler shift of the bow wave at the black hole, where it stimulates the emission of monochromatic Hawking radiation. This mechanism is confirmed using temporal and spatial windowed Fourier spectra of the condensate. We also find that shot-to-shot atom number variations, of the type normally realized in ultracold-atom experiments, and quantum fluctuations of condensates, as computed in the Bogoliubov-De Gennes approximation, give density-density correlations consistent with those reported in the experiments. In particular, atom number variations can produce a spurious correlation signal.

How Will Climate Change Affect Explosive Cyclones in the Extratropics of the Northern Hemisphere?

NASA Astrophysics Data System (ADS)

Seiler, C.; Zwiers, F. W.

2015-12-01

Explosive cyclones are rapidly intensifying low pressure systems generating severe wind speeds and heavy precipitation primarily in coastal and marine environments, such as the March 2014 nor'easter which developed along the United States coastline, with hurricane force winds in eastern Maine and the Maritimes. This study presents the first analysis on how explosive cyclones respond to climate change in the extratropics of the Northern Hemisphere. An objective-feature tracking algorithm is used to identify and track cyclones from 23 CMIP5 climate models for the recent past (1981-1999) and future (2081-2099). Explosive cyclones are projected to shift northwards by about 2.2° latitude on average in the northern Pacific, with fewer and weaker events south of 45°N, and more frequent and stronger events north of this latitude. This shift is correlated with a poleward shift of the jet stream in the inter-model spread (R = 0.56). In the Atlantic, the total number of explosive cyclones is projected to decrease by about 17% when averaging across models, with the largest changes occurring along North America's East Coast. This reduction is correlated with a decline in the lower-tropospheric Eady growth rate (R = 0.51), and is stronger for models with smaller frequency biases (R = -0.65). The same region is also projected to experience a small intensification of explosive cyclones, with larger vorticity values for models that predict stronger increases in the speed of the jet stream (R = 0.58). This strengthening of the jet stream is correlated with an enhanced sea surface temperature gradient in the North Atlantic (R = -0.63). The inverse relationship between model bias and projection, and the role of model resolution are discussed.

Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

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

Zlateva, Y.; El Naqa, I.; Quitoriano, N.

2014-08-15

We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs),more » emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.« less

In vivo two-dimensional NMR correlation spectroscopy

NASA Astrophysics Data System (ADS)

Kraft, Robert A.

1999-10-01

The poor resolution of in-vivo one- dimensional nuclear magnetic resonance spectroscopy (NMR) has limited its clinical potential. Currently, only the large singlet methyl resonances arising from N-acetyl aspartate (NAA), choline, and creatine are quantitated in a clinical setting. Other metabolites such as myo- inositol, glutamine, glutamate, lactate, and γ- amino butyric acid (GABA) are of clinical interest but quantitation is difficult due to the overlapping resonances and limited spectral resolution. To improve the spectral resolution and distinguish between overlapping resonances, a series of two- dimensional chemical shift correlation spectroscopy experiments were developed for a 1.5 Tesla clinical imaging magnet. Two-dimensional methods are attractive for in vivo spectroscopy due to their ability to unravel overlapping resonances with the second dimension, simplifying the interpretation and quantitation of low field NMR spectra. Two-dimensional experiments acquired with mix-mode line shape negate the advantages of the second dimension. For this reason, a new experiment, REVOLT, was developed to achieve absorptive mode line shape in both dimensions. Absorptive mode experiments were compared to mixed mode experiments with respect to sensitivity, resolution, and water suppression. Detailed theoretical and experimental calculations of the optimum spin lock and radio frequency power deposition were performed. Two-dimensional spectra were acquired from human bone marrow and human brain tissue. The human brain tissue spectra clearly reveal correlations among the coupled spins of NAA, glutamine, glutamate, lactate, GABA, aspartate and myo-inositol obtained from a single experiment of 23 minutes from a volume of 59 mL. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska

USGS Publications Warehouse

Alexeev, Vladimir; Arp, Christopher D.; Jones, Benjamin M.; Cai, Lei

2016-01-01

Field measurements, satellite observations, and models document a thinning trend in seasonal Arctic lake ice growth, causing a shift from bedfast to floating ice conditions. September sea ice concentrations in the Arctic Ocean since 1991 correlate well (r = +0.69,p < 0.001) to this lake regime shift. To understand how and to what extent sea ice affects lakes, we conducted model experiments to simulate winters with years of high (1991/92) and low (2007/08) sea ice extent for which we also had field measurements and satellite imagery characterizing lake ice conditions. A lake ice growth model forced with Weather Research and Forecasting model output produced a 7% decrease in lake ice growth when 2007/08 sea ice was imposed on 1991/92 climatology and a 9% increase in lake ice growth for the opposing experiment. Here, we clearly link early winter 'ocean-effect' snowfall and warming to reduced lake ice growth. Future reductions in sea ice extent will alter hydrological, biogeochemical, and habitat functioning of Arctic lakes and cause sub-lake permafrost thaw.

Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees

PubMed Central

LaZerte, Stefanie E.; Slabbekoorn, Hans; Otter, Ken A.

2016-01-01

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees (Poecile atricapillus) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher-frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city. PMID:27358372

Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees.

PubMed

LaZerte, Stefanie E; Slabbekoorn, Hans; Otter, Ken A

2016-06-29

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees (Poecile atricapillus) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher-frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city. © 2016 The Author(s).

Isotopically Enriched C-13 Diamond Anvil as a Stress Sensor in High Pressure Experiments

NASA Astrophysics Data System (ADS)

Vohra, Yogesh; Qiu, Wei; Kondratyev, Andreiy; Velisavljevic, Nenad; Baker, Paul

2004-03-01

The conventional high pressure diamond anvils were modified by growing an isotopically pure C-13 diamond layer by microwave plasma chemical vapor deposition using methane/hydrogen/oxygen chemistry. The isotopically pure C-13 nature of the culet of the diamond anvil was confirmed by the Raman spectroscopy measurements. This isotopically engineered diamond anvil was used against a natural abundance diamond anvil for high pressure experiments in a diamond anvil cell. Spatial resolved Raman spectroscopy was used to measure the stress induced shift in the C-13 layer as well as the undelying C-12 layer to ultra high pressures. The observed shift and splitiing of the diamond first order Raman spectrum was correlated with the stress distribution in the diamond anvil cell. The experimental results will be compared with the finite element modeling results using NIKE-2D software in order to create a mathematical relationship between sets of the following parameters: vertical (z axis) distance; horizontal (r axis) distance; max shear stress, and pressure. The isotopically enriched diamond anvils offer unique opportunities to measure stress distribution in the diamond anvil cell devices.

Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C, 15N-labeled peptides and proteins

NASA Astrophysics Data System (ADS)

Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

2010-03-01

In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly 13C, 15N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22 kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600 MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i - 2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed.

Surface enhanced Raman spectroscopy of the silver/KCl, triethylenediamine (DABCO), water system

NASA Astrophysics Data System (ADS)

Irish, D. E.; Guzonas, D.; Atkinson, G. F.

1985-07-01

1,4-Diazabicyclo[2.2.2]octane, (N(CH 2CH 2) 3N), usually abbreviated DABCO or DBO, is a symmetric top molecule of point group D 3h. SERS experiments have been carried out in an optical electrochemical cell using a silver electrode roughened by a single oxidation-reduction cycle (ORC). The observed SERS spectra contained four strong bands at 624, 798, 990 and 1351 cm -1, all A' 1 totally symmetric modes. The same bands were also observed in SERS spectra of DABCO adsorbed on colloidal gold. In the electrochemical experiments, the maximum of SERS-intensity versus electrode potential plots was observed to shift to less negative potentials as the wavelength of the exciting line was shifted to the red. The radically-altered, relative intensities of the observed bands, as well as observed changes in relative intensity as a function of electrode potential, have been interpreted as a selective enhancement of those normal modes which have as a major component of vibrational motion the C-C stretch. These observations are correlated with current theories concerning the SERS mechanism, especially those involving charge transfer (CT).

Double resonance calibration of g factor standards: Carbon fibers as a high precision standard

NASA Astrophysics Data System (ADS)

Herb, Konstantin; Tschaggelar, Rene; Denninger, Gert; Jeschke, Gunnar

2018-04-01

The g factor of paramagnetic defects in commercial high performance carbon fibers was determined by a double resonance experiment based on the Overhauser shift due to hyperfine coupled protons. Our carbon fibers exhibit a single, narrow and perfectly Lorentzian shaped ESR line and a g factor slightly higher than gfree with g = 2.002644 =gfree · (1 + 162ppm) with a relative uncertainty of 15ppm . This precisely known g factor and their inertness qualify them as a high precision g factor standard for general purposes. The double resonance experiment for calibration is applicable to other potential standards with a hyperfine interaction averaged by a process with very short correlation time.

Progress in high temperature speckle-shift strain measurement system

NASA Technical Reports Server (NTRS)

Lant, Christian T.; Barranger, John P.

1990-01-01

A fast, easy to use speckle tracking system is under development for the speckle-shift strain measurement technique. Preliminary correlation tests on wire specimens show strong correlations of well-developed speckle patterns. Stable cross-correlations were obtained from a tungsten filament at 2480 C. An analysis of the optical system determines the minimum required sampling frequency of the speckle pattern to be 2.55 pixels per speckle.

Digital Holographic Interferometry and Speckle Correlation

NASA Astrophysics Data System (ADS)

Yamaguchi, Ichirou

2010-04-01

Relations and combinations between holographic interferometry and speckle correlation in contouring by phase-shifting digital holography are discussed. Three-dimensional distributions of correlations of the complex amplitudes and intensities before and after the laser wavelength shift are calculated in numerical simulations where a rough surface is modeled with random numbers. Fringe localization related to speckle displacement as well as speckle suppression in phase analysis are demonstrated for general surface shape and recording conditions.

Exploring Initiative as a Signal of Knowledge Co-Construction During Collaborative Problem Solving.

PubMed

Howard, Cynthia; Di Eugenio, Barbara; Jordan, Pamela; Katz, Sandra

2017-08-01

Peer interaction has been found to be conducive to learning in many settings. Knowledge co-construction (KCC) has been proposed as one explanatory mechanism. However, KCC is a theoretical construct that is too abstract to guide the development of instructional software that can support peer interaction. In this study, we present an extensive analysis of a corpus of peer dialogs that we collected in the domain of introductory Computer Science. We show that the notion of task initiative shifts correlates with both KCC and learning. Speakers take task initiative when they contribute new content that advances problem solving and that is not invited by their partner; if initiative shifts between the partners, it indicates they both contribute to problem solving. We found that task initiative shifts occur more frequently within KCC episodes than outside. In addition, task initiative shifts within KCC episodes correlate with learning for low pre-testers, and total task initiative shifts correlate with learning for high pre-testers. As recognizing task initiative shifts does not require as much deep knowledge as recognizing KCC, task initiative shifts as an indicator of productive collaboration are potentially easier to model in instructional software that simulates a peer. Copyright © 2016 Cognitive Science Society, Inc.

Examining Event-Related Potential (ERP) Correlates of Decision Bias in Recognition Memory Judgments

PubMed Central

Hill, Holger; Windmann, Sabine

2014-01-01

Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500–700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions. PMID:25264982

Examining Event-Related Potential (ERP) correlates of decision bias in recognition memory judgments.

PubMed

Hill, Holger; Windmann, Sabine

2014-01-01

Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500-700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions.

Effects of protein-pheromone complexation on correlated chemical shift modulations.

PubMed

Perazzolo, Chiara; Wist, Julien; Loth, Karine; Poggi, Luisa; Homans, Steve; Bodenhausen, Geoffrey

2005-12-01

Major urinary protein (MUP) is a pheromone-carrying protein of the lipocalin family. Previous studies by isothermal titration calorimetry (ITC) show that the affinity of MUP for the pheromone 2-methoxy-3-isobutylpyrazine (IBMP) is mainly driven by enthalpy, with a small unfavourable entropic contribution. Entropic terms can be attributed in part to changes in internal motions of the protein upon binding. Slow internal motions can lead to correlated or anti-correlated modulations of the isotropic chemical shifts of carbonyl C' and amide N nuclei. Correlated chemical shift modulations (CSM/CSM) in MUP have been determined by measuring differences of the transverse relaxation rates of zero- and double-quantum coherences ZQC{C'N} and DQC{C'N}, and by accounting for the effects of correlated fluctuations of dipole-dipole couplings (DD/DD) and chemical shift anisotropies (CSA/CSA). The latter can be predicted from tensor parameters of C' and N nuclei that have been determined in earlier work. The effects of complexation on slow time-scale protein dynamics can be determined by comparing the temperature dependence of the relaxation rates of APO-MUP (i.e., without ligand) and HOLO-MUP (i.e., with IBMP as a ligand).

Causal Correlation Functions and Fourier Transforms: Application in Calculating Pressure Induced Shifts

NASA Technical Reports Server (NTRS)

Ma, Q.; Tipping, R. H.; Lavrentieva, N. N.

2012-01-01

By adopting a concept from signal processing, instead of starting from the correlation functions which are even, one considers the causal correlation functions whose Fourier transforms become complex. Their real and imaginary parts multiplied by 2 are the Fourier transforms of the original correlations and the subsequent Hilbert transforms, respectively. Thus, by taking this step one can complete the two previously needed transforms. However, to obviate performing the Cauchy principal integrations required in the Hilbert transforms is the greatest advantage. Meanwhile, because the causal correlations are well-bounded within the time domain and band limited in the frequency domain, one can replace their Fourier transforms by the discrete Fourier transforms and the latter can be carried out with the FFT algorithm. This replacement is justified by sampling theory because the Fourier transforms can be derived from the discrete Fourier transforms with the Nyquis rate without any distortions. We apply this method in calculating pressure induced shifts of H2O lines and obtain more reliable values. By comparing the calculated shifts with those in HITRAN 2008 and by screening both of them with the pair identity and the smooth variation rules, one can conclude many of shift values in HITRAN are not correct.

Noise, stress, and annoyance in a pediatric intensive care unit.

PubMed

Morrison, Wynne E; Haas, Ellen C; Shaffner, Donald H; Garrett, Elizabeth S; Fackler, James C

2003-01-01

To measure and describe hospital noise and determine whether noise can be correlated with nursing stress measured by questionnaire, salivary amylase, and heart rate. Cohort observational study. Tertiary care center pediatric intensive care unit. Registered nurses working in the unit. None. Eleven nurse volunteers were recruited. An audiogram, questionnaire data, salivary amylase, and heart rate were collected in a quiet room. Each nurse was observed for a 3-hr period during patient care. Heart rate and sound level were recorded continuously; saliva samples and stress/annoyance ratings were collected every 30 mins. Variables assessed as potential confounders were years of nursing experience, caffeine intake, patients' Pediatric Risk of Mortality Score, shift assignment, and room assignment. Data were analyzed by random effects multiple linear regression using Stata 6.0. The average daytime sound level was 61 dB(A), nighttime 59 dB(A). Higher average sound levels significantly predicted higher heart rates (p =.014). Other significant predictors of tachycardia were higher caffeine intake, less nursing experience, and daytime shift. Ninety percent of the variability in heart rate was explained by the regression equation. Amylase measurements showed a large variability and were not significantly affected by noise levels. Higher average sound levels were also predictive of greater subjective stress (p =.021) and annoyance (p =.016). In this small study, noise was shown to correlate with several measures of stress including tachycardia and annoyance ratings. Further studies of interventions to reduce noise are essential.

Analysis of the Electronic Structure of the Special Pair of a Bacterial Photosynthetic Reaction Center by 13 C Photochemically Induced Dynamic Nuclear Polarization Magic-Angle Spinning NMR Using a Double-Quantum Axis.

PubMed

Najdanova, Marija; Gräsing, Daniel; Alia, A; Matysik, Jörg

2018-01-01

The origin of the functional symmetry break in bacterial photosynthesis challenges since several decades. Although structurally very similar, the two branches of cofactors in the reaction center (RC) protein complex act very differently. Upon photochemical excitation, an electron is transported along one branch, while the other remains inactive. Photochemically induced dynamic nuclear polarization (photo-CIDNP) magic-angle spinning (MAS) 13 C NMR revealed that the two bacteriochlorophyll cofactors forming the "Special Pair" donor dimer are already well distinguished in the electronic ground state. These previous studies are relying solely on 13 C- 13 C correlation experiments as radio-frequency-driven recoupling (RFDR) and dipolar-assisted rotational resonance (DARR). Obviously, the chemical-shift assignment is difficult in a dimer of tetrapyrrole macrocycles, having eight pyrrole rings of similar chemical shifts. To overcome this problem, an INADEQUATE type of experiment using a POST C7 symmetry-based approach is applied to selectively isotope-labeled bacterial RC of Rhodobacter (R.) sphaeroides wild type (WT). We, therefore, were able to distinguish unresolved sites of the macromolecular dimer. The obtained chemical-shift pattern is in-line with a concentric assembly of negative charge within the common center of the Special Pair supermolecule in the electronic ground state. © 2017 The American Society of Photobiology.

[Comparison of red edge parameters of winter wheat canopy under late frost stress].

PubMed

Wu, Yong-feng; Hu, Xin; Lü, Guo-hua; Ren, De-chao; Jiang, Wei-guo; Song, Ji-qing

2014-08-01

In the present study, late frost experiments were implemented under a range of subfreezing temperatures (-1 - -9 degrees C) by using a field movable climate chamber (FMCC) and a cold climate chamber, respectively. Based on the spectra of winter wheat canopy measured at noon on the first day after the frost experiments, red edge parameters REP, Dr, SDr, Dr(min), Dr/Dr(min) and Dr/SDr were extracted using maximum first derivative spectrum method (FD), linear four-point interpolation method (FPI), polynomial fitting method (POLY), inverted Gaussian fitting method (IG) and linear extrapolation technique (LE), respectively. The capacity of the red edge parameters to detect late frost stress was explicated from the aspects of the early, sensitivity and stability through correlation analysis, linear regression modeling and fluctuation analysis. The result indicates that except for REP calculated from FPI and IG method in Experiment 1, REP from the other methods was correlated with frost temperatures (P < 0.05). Thereinto, significant levels (P) of POLY and LE methods all reached 0.01. Except for POLY method in Experiment 2, Dr/SDr from the other methods were all significantly correlated with frost temperatures (P < 0.01). REP showed a trend to shift to short-wave band with decreasing temperatures. The lower the temperature, the more obvious the trend is. Of all the REP, REP calculated by LE method had the highest correlation with frost temperatures which indicated that LE method is the best for REP extraction. In Experiment 1 and 2, only Dr(min) and Dr/Dr(min), calculated by FD method simultaneously achieved the requirements for the early (their correlations with frost temperatures showed a significant level P < 0.01), sensitivity (abso- lute value of the slope of fluctuation coefficient is greater than 2.0) and stability (their correlations with frost temperatures al- ways keep a consistent direction). Dr/SDr calculated from FD and IG methods always had a low sensitivity in Experiment 2. In Experiment 1, the sensitivity of Dr/SDr from FD was moderate and IG was high. REP calculated from LE method had a lowest sensitivity in the two experiments. Totally, Dr(min) and Dr/Dr(min) calculated by FD method have the strongest detection capacity for frost temperature, which will be helpful to conducting the research on early diagnosis of late frost injury to winter wheat.

An analysis of clock-shift experiments: is scatter increased and deflection reduced in clock-shifted homing pigeons?

PubMed

Chappell

1997-01-01

Clock-shifting (altering the phase of the internal clock) in homing pigeons leads to a deflection in the vanishing bearing of the clock-shifted group relative to controls. However, two unexplained phenomena are common in clock-shift experiments: the vanishing bearings of the clock-shifted group are often more scattered (with a shorter vector length) than those of the control group, and the deflection of the mean bearing of the clock-shifted group from that of the controls is often smaller than expected theoretically. Here, an analysis of 55 clock-shift experiments performed in four countries over 21 years is reported. The bearings of the clock-shifted groups were significantly more scattered than those of controls and less deflected than expected, but these effects were not significantly different at familiar and unfamiliar sites. The possible causes of the effects are discussed and evaluated with reference to this analysis and other experiments. The most likely causes appear to be conflict between the directions indicated by the sun compass and either unshifted familiar visual landmarks (at familiar sites only) or the unshifted magnetic compass (possible at both familiar and unfamiliar sites).

A meta-analysis including dose-response relationship between night shift work and the risk of colorectal cancer.

PubMed

Wang, Xiao; Ji, Alin; Zhu, Yi; Liang, Zhen; Wu, Jian; Li, Shiqi; Meng, Shuai; Zheng, Xiangyi; Xie, Liping

2015-09-22

A meta-analysis was conducted to quantitatively evaluate the correlation between night shift work and the risk of colorectal cancer. We searched for publications up to March 2015 using PubMed, Web of Science, Cochrane Library, EMBASE and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles and relevant reviews were also checked. OR and 95% CI were used to assess the degree of the correlation between night shift work and risk of colorectal cancer via fixed- or random-effect models. A dose-response meta-analysis was performed as well. The pooled OR estimates of the included studies illustrated that night shift work was correlated with an increased risk of colorectal cancer (OR = 1.318, 95% CI 1.121-1.551). No evidence of publication bias was detected. In the dose-response analysis, the rate of colorectal cancer increased by 11% for every 5 years increased in night shift work (OR = 1.11, 95% CI 1.03-1.20). In conclusion, this meta-analysis indicated that night shift work was associated with an increased risk of colorectal cancer. Further researches should be conducted to confirm our findings and clarify the potential biological mechanisms.

A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

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

Feister, S., E-mail: feister.7@osu.edu; Orban, C.; Innovative Scientific Solutions, Inc., Dayton, Ohio 45459

Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiersmore » synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements with instantaneous plasma profiles and for enabling realistic Particle-in-Cell simulations of the ultra-intense laser-matter interaction.« less

Influence of Fiber Bragg Grating Spectrum Degradation on the Performance of Sensor Interrogation Algorithms

PubMed Central

Lamberti, Alfredo; Vanlanduit, Steve; De Pauw, Ben; Berghmans, Francis

2014-01-01

The working principle of fiber Bragg grating (FBG) sensors is mostly based on the tracking of the Bragg wavelength shift. To accomplish this task, different algorithms have been proposed, from conventional maximum and centroid detection algorithms to more recently-developed correlation-based techniques. Several studies regarding the performance of these algorithms have been conducted, but they did not take into account spectral distortions, which appear in many practical applications. This paper addresses this issue and analyzes the performance of four different wavelength tracking algorithms (maximum detection, centroid detection, cross-correlation and fast phase-correlation) when applied to distorted FBG spectra used for measuring dynamic loads. Both simulations and experiments are used for the analyses. The dynamic behavior of distorted FBG spectra is simulated using the transfer-matrix approach, and the amount of distortion of the spectra is quantified using dedicated distortion indices. The algorithms are compared in terms of achievable precision and accuracy. To corroborate the simulation results, experiments were conducted using three FBG sensors glued on a steel plate and subjected to a combination of transverse force and vibration loads. The analysis of the results showed that the fast phase-correlation algorithm guarantees the best combination of versatility, precision and accuracy. PMID:25521386

An Evaluation of the Relationship among Urine, Air, and Hand Measures of Exposure to Bisphenol A (BPA) in US Manufacturing Workers.

PubMed

Hines, Cynthia J; Christianson, Annette L; Jackson, Matthew V; Ye, Xiaoyun; Pretty, Jack R; Arnold, James E; Calafat, Antonia M

2018-06-13

Exposure to bisphenol A (BPA) can be assessed using external and internal exposure measures. We examined the relationship between two measures of external BPA exposure (air and hand-wipe samples) and one of internal exposure (total BPA in urine) for a group of US manufacturing workers. During 2013-2014, we recruited 78 workers from six US companies that made BPA or made products with BPA. We quantified BPA in seven urine samples, two full-shift air samples and in pre- and end-shift hand-wipe samples collected from workers over 2 consecutive days. We examined correlations between creatinine-corrected urinary concentrations of total BPA (total BPACR) and BPA levels in air and hand wipes using Pearson's correlation coefficient. We also applied mixed-effects regression models to examine the relationship between total BPACR with BPA in air (urine~air model) and with BPA in end-shift hand wipes (urine~hand model), separately and together (urine~air+hand model), after adjusting for covariates. End-shift total BPACR strongly correlated with BPA in air (rp = 0.79, P < 0.0001) and nearly as strongly with BPA in end-shift hand wipes (rp = 0.75, P < 0.0001). In mixed-effect models, BPA air concentration and end-shift hand-wipe BPA level were significantly and positively associated with end-shift total BPACR (P < 0.0001 each). We found a significant effect of the Day 1 BPA air concentration on Day 2 total BPACR (P = 0.0104). When BPA air concentration and end-shift hand-wipe BPA level were in the same model, the air concentration (P < 0.0001) was more significant than the hand-wipe level (P = 0.0106). BPA levels in air and end-shift hand wipes strongly correlated with total BPACR, suggesting that both inhalation and dermal contract were likely exposure routes; however, inhalation, on average, appeared to be a more dominant exposure route than dermal contact for these manufacturing workers.

Reduced dimensionality tailored HN(C)N experiments for facile backbone resonance assignment of proteins through unambiguous identification of sequential HSQC peaks

NASA Astrophysics Data System (ADS)

Kumar, Dinesh

2013-12-01

Two novel reduced dimensionality (RD) tailored HN(C)N [S.C. Panchal, N.S. Bhavesh, R.V. Hosur, Improved 3D triple resonance experiments, HNN and HN(C)N, for HN and 15N sequential correlations in (13C, 15N) labeled proteins: application to unfolded proteins, J. Biomol. NMR 20 (2001) 135-147] experiments are proposed to facilitate the backbone resonance assignment of proteins both in terms of its accuracy and speed. These experiments - referred here as (4,3)D-hNCOcaNH and (4,3)D-hNcoCANH - exploit the linear combination of backbone 15N and 13C‧/13Cα chemical shifts simultaneously to achieve higher peak dispersion and randomness along their respective F1 dimensions. Simply, this has been achieved by modulating the backbone 15N(i) chemical shifts with that of 13C‧ (i - 1)/13Cα (i - 1) spins following the established reduced dimensionality NMR approach [T. Szyperski, D.C. Yeh, D.K. Sukumaran, H.N. Moseley, G.T. Montelione, Reduced-dimensionality NMR spectroscopy for high-throughput protein resonance assignment, Proc. Natl. Acad. Sci. USA 99 (2002) 8009-8014]. Though the modification is simple it has resulted an ingenious improvement of HN(C)N both in terms of peak dispersion and easiness of establishing the sequential connectivities. The increased dispersion along F1 dimension solves two purposes here: (i) resolves the ambiguities arising because of degenerate 15N chemical shifts and (ii) reduces the signal overlap in F2(15N)-F3(1H) planes (an important requisite in HN(C)N based assignment protocol for facile and unambiguous identification of sequentially connected HSQC peaks). The performance of both these experiments and the assignment protocol has been demonstrated using bovine apo Calbindin-d9k (75 aa) and urea denatured UNC60B (a 152 amino acid ADF/cofilin family protein of Caenorhabditis elegans), as representatives of folded and unfolded protein systems, respectively.

Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation

USGS Publications Warehouse

McCabe, G.J.; Clark, M.P.

2006-01-01

Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.

Incubation rhythm in the Fulmar Fulmarus glacialis: Annual variation and sex roles

USGS Publications Warehouse

Hatch, Scott A.

1990-01-01

I monitored the incubation schedules of Fulmars Fulmarus glacialis in an Alaskan colony by observing nests where the male and female were of different colour phases. Complete shifts of up to 16 days were recorded; the average shift in mid-incubation was 4–6 days. Mean shift length was inversely correlated with hatching success in 5 years, suggesting that Fulmars adjusted their foraging patterns to annual differences in food availability. Males assumed the larger share (55%) of incubation on average, and a larger share in years with lower hatching success. Serial correlation in the length of incubation shifts had two components - the influence of prior shift lengths on time spent foraging and individual variation. Failure of the male to relieve the female soon after laying resulted in a few breeding failures and egg losses were associated with exceptionally long shifts throughout incubation.

Mixed pyruvate labeling enables backbone resonance assignment of large proteins using a single experiment.

PubMed

Robson, Scott A; Takeuchi, Koh; Boeszoermenyi, Andras; Coote, Paul W; Dubey, Abhinav; Hyberts, Sven; Wagner, Gerhard; Arthanari, Haribabu

2018-01-24

Backbone resonance assignment is a critical first step in the investigation of proteins by NMR. This is traditionally achieved with a standard set of experiments, most of which are not optimal for large proteins. Of these, HNCA is the most sensitive experiment that provides sequential correlations. However, this experiment suffers from chemical shift degeneracy problems during the assignment procedure. We present a strategy that increases the effective resolution of HNCA and enables near-complete resonance assignment using this single HNCA experiment. We utilize a combination of 2- 13 C and 3- 13 C pyruvate as the carbon source for isotope labeling, which suppresses the one bond ( 1 J αβ ) coupling providing enhanced resolution for the Cα resonance and amino acid-specific peak shapes that arise from the residual coupling. Using this approach, we can obtain near-complete (>85%) backbone resonance assignment of a 42 kDa protein using a single HNCA experiment.

Correlates to sleepiness on night shift among male workers engaged in three-shift work in a chemical plant: its association with sleep practice and job stress.

PubMed

Kageyama, Takayuki; Kobayashi, Toshio; Abe-Gotoh, Ayano

2011-01-01

The purpose of this study was to examine the correlation of sleepiness during night shift (SNS) in male shiftworkers with nonpharmacological self-management (nPSM) practices to facilitate good day sleep, and also with job stress. Sleepiness on the job and possible correlates to SNS among 157 male shiftworkers in a rotating three-shift schedule at a chemical plant were cross-sectionally investigated using a self-administered questionnaire. Multivariate analyses revealed that SNS was positively associated with drinking alcoholic beverages before day sleep, but inversely associated with subjective health status, being of the evening type, abstaining from caffeine before day sleep, having a bath before day sleep, job control, reward from work, feeling suited to the job, and support from colleagues. SNS correlated with certain nPSM practices and also with possible modifiers of job stress. These findings provide clues to developing countermeasures against SNS among shiftworkers. The effects of nPSM practices and job stress management on their day sleep and SNS should be examined in detail.

Cognitive Inflexibility and Frontal-Cortical Activation in Pediatric Obsessive-Compulsive Disorder

PubMed Central

Britton, Jennifer C.; Rauch, Scott L.; Rosso, Isabelle M.; Killgore, William D.S.; Price, Lauren M.; Ragan, Jennifer; Chosak, Anne; Hezel, Dianne M.; Pine, Daniel S.; Leibenluft, Ellen; Pauls, David L.; Jenike, Michael A.; Stewart, S. Evelyn

2014-01-01

Objective Deficits in cognitive flexibility and response inhibition have been linked to perturbations in cortico-striatal-thalamic circuitry in adult obsessive-compulsive disorder (OCD). Although similar cognitive deficits have been identified in pediatric OCD, few neuroimaging studies have been conducted to examine its neural correlates in the developing brain. In this study, we tested hypotheses regarding group differences in the behavioral and neural correlates of cognitive flexibility in a pediatric OCD and a healthy comparison (HC) sample. Method In this functional magnetic resonance imaging (fMRI) study, a pediatric sample of 10- to 17-year-old subjects, 15 with OCD and 20 HC, completed a set-shifting task. The task, requiring an extradimensional shift to identify a target, examines cognitive flexibility. Within each block, the dimension (color or shape) that identified the target either alternated (i.e., mixed) or remained unchanged (i.e., repeated). Results Compared with the HC group, the OCD group tended to be slower to respond to trials within mixed blocks. Compared with the HC group, the OCD group exhibited less left inferior frontal gyrus/BA47 activation in the set-shifting contrast (i.e., HC > OCD, mixed versus repeated); only the HC group exhibited significant activation in this region. The correlation between set shifting-induced right caudate activation and shift cost (i.e., reaction time differential in response to mixed versus repeated trials) was significantly different between HC and OCD groups, in that we found a positive correlation in HC and a negative correlation in OCD. Conclusions In pediatric OCD, less fronto-striatal activation may explain previously identified deficits in shifting cognitive sets. PMID:20732630

Communication: Direct comparison between theory and experiment for correlated angular and product-state distributions of the ground-state and stretching-excited O(3P) + CH4 reactions

NASA Astrophysics Data System (ADS)

Czakó, Gábor

2014-06-01

Motivated by a recent experiment [H. Pan and K. Liu, J. Chem. Phys. 140, 191101 (2014)], we report a quasiclassical trajectory study of the O(3P) + CH4(vk = 0, 1) → OH + CH3 [k = 1 and 3] reactions on an ab initio potential energy surface. The computed angular distributions and cross sections correlated to the OH(v = 0, 1) + CH3(v = 0) coincident product states can be directly compared to experiment for O + CH4(v3 = 0, 1). Both theory and experiment show that the ground-state reaction is backward scattered, whereas the angular distributions shift toward sideways and forward directions upon antisymmetric stretching (v3) excitation of the reactant. Theory predicts similar behavior for the O + CH4(v1 = 1) reaction. The simulations show that stretching excitation enhances the reaction up to about 15 kcal/mol collision energy, whereas the O + CH4(vk = 1) reactions produce smaller cross sections for OH(v = 1) + CH3(v = 0) than those of O + CH4(v = 0) → OH(v = 0) + CH3(v = 0). The former finding agrees with experiment and the latter awaits for confirmation. The computed cold OH rotational distributions of O + CH4(v = 0) are in good agreement with experiment.

Communication: direct comparison between theory and experiment for correlated angular and product-state distributions of the ground-state and stretching-excited O((3)P) + CH4 reactions.

PubMed

Czakó, Gábor

2014-06-21

Motivated by a recent experiment [H. Pan and K. Liu, J. Chem. Phys. 140, 191101 (2014)], we report a quasiclassical trajectory study of the O((3)P) + CH4(vk = 0, 1) → OH + CH3 [k = 1 and 3] reactions on an ab initio potential energy surface. The computed angular distributions and cross sections correlated to the OH(v = 0, 1) + CH3(v = 0) coincident product states can be directly compared to experiment for O + CH4(v3 = 0, 1). Both theory and experiment show that the ground-state reaction is backward scattered, whereas the angular distributions shift toward sideways and forward directions upon antisymmetric stretching (v3) excitation of the reactant. Theory predicts similar behavior for the O + CH4(v1 = 1) reaction. The simulations show that stretching excitation enhances the reaction up to about 15 kcal/mol collision energy, whereas the O + CH4(vk = 1) reactions produce smaller cross sections for OH(v = 1) + CH3(v = 0) than those of O + CH4(v = 0) → OH(v = 0) + CH3(v = 0). The former finding agrees with experiment and the latter awaits for confirmation. The computed cold OH rotational distributions of O + CH4(v = 0) are in good agreement with experiment.

Overnight fluid shifts in subjects with and without obstructive sleep apnea

PubMed Central

Ding, Ning; Lin, Wei; Zhang, Xi-Long; Ding, Wen-Xiao; Gu, Bing; Ni, Bu-Qing; Zhang, Wei; Zhang, Shi-Jiang

2014-01-01

Objective To investigate the characteristics of baseline body fluid content and overnight fluid shifts between non-obstructive sleep apnea (non-OSA) and obstructive sleep apnea (OSA) subjects. Methods A case-controlled study was performed between February 2013 and January 2014, with 36 (18 OSA and 18 non-OSA) outpatients enrolled in this study. Polysomnographic parameters and results of body fluid were compared between the two groups. Results There were no differences in age, weight, and body mass index (BMI) between groups. Compared with the non-OSA group, OSA group had significantly higher neck circumference (NC) and fluid volume shift in the legs. OSA patients had higher left and right leg fluid indices than non-OSA subjects. There were significant correlations between apnoea-hypopnoea index and baseline fluid indices in both legs as well as the reduction in overnight change in both legs fluid volume. The increase in NC was also significantly correlated with the reduction in overnight change in both legs fluid volume, but not with the change in head and neck fluid volume. There were significant correlations between change in NC and increased fluid shifts in head and neck volume. Conclusions OSA patients had a higher baseline fluid content in both legs as compared with non-OSA subjects, which may be the basic factor with regards to fluid shifts in OSA patients. The increase in head and neck fluid shift volume did not directly correlate with the severity of OSA. PMID:25589967

Potential for Higher Treatment Failure in Obese Patients: Correlation of Elevated Body Mass Index and Increased Daily Prostate Deviations From the Radiation Beam Isocenters in an Analysis of 1,465 Computed Tomographic Images

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

Wong, James R.; Gao Zhanrong; Merrick, Scott

2009-09-01

Purpose: Recent clinical outcome studies on prostate cancer have reported the influence of patient's obesity on the biochemical failure rates after various treatment modalities. In this study, we investigated the effect of patient's physical characteristics on prostate shift in external beam radiotherapy (EBRT) and hypothesized that there maybe a correlation between patient physique and tumor shift. Methods and Materials: A retrospective analysis was performed using data for 117 patients who received image-guided radiation therapy (IGRT) for prostate cancer between January 2005 and April 2007. A total of 1,465 CT scans were analyzed. The standard deviations (SDs) of prostate shifts formore » all patients, along with patient weight, body mass index (BMI), and subcutaneous adipose-tissue thickness (SAT), were determined. Spearman rank correlation analysis was performed. Results: Of the 117 patients, 26.5% were considered normal weight, 48.7% were overweight, 17.9% were mildly obese, and 6.9% were moderately to severely obese. Notably 1.3%, 1.5%, 2.0%, and 21.2% of the respective shifts were greater than 10 mm in the left-right (LR) direction for the four patient groups, whereas in the anterior-posterior direction the shifts are 18.2%, 12.6%, 6.7%, and 21.0%, respectively. Strong correlations were observed between SAT, BMI, patient weight, and SDs of daily shifts in the LR direction (p < 0.01). Conclusions: The strong correlation between obesity and shift indicates that without image-guided radiation therapy, the target volume (prostate with or without seminal vesicles) may not receive the intended dose for patients who are moderate to severely obese. This may explain the higher recurrence rate with conventional external beam radiation therapy.« less

Theoretical study of the NMR chemical shift of Xe in supercritical condition.

PubMed

Lacerda, Evanildo G; Sauer, Stephan P A; Mikkelsen, Kurt V; Coutinho, Kaline; Canuto, Sylvio

2018-02-20

In this work we investigate the level of theory necessary for reproducing the non-linear variation of the 129 Xe nuclear magnetic resonance (NMR) chemical shift with the density of Xe in supercritical conditions. In detail we study how the 129 Xe chemical shift depends under supercritical conditions on electron correlation, relativistic and many-body effects. The latter are included using a sequential-QM/MM methodology, in which a classical MD simulation is performed first and the chemical shift is then obtained as an average of quantum calculations of 250 MD snapshots conformations carried out for Xe n clusters (n = 2 - 8 depending on the density). The analysis of the relativistic effects is made at the level of 4-component Hartree-Fock calculations (4c-HF) and electron correlation effects are considered using second order Møller-Plesset perturbation theory (MP2). To simplify the calculations of the relativistic and electron correlation effects we adopted an additive scheme, where the calculations on the Xe n clusters are carried out at the non-relativistic Hartree-Fock (HF) level, while electron correlation and relativistic corrections are added for all the pairs of Xe atoms in the clusters. Using this approach we obtain very good agreement with the experimental data, showing that the chemical shift of 129 Xe in supercritical conditions is very well described by cluster calculations at the HF level, with small contributions from relativistic and electron correlation effects.

Neural correlates of set-shifting in children with autism

PubMed Central

Yerys, Benjamin E.; Antezana, Ligia; Weinblatt, Rachel; Jankowski, Kathryn F.; Strang, John; Vaidya, Chandan J.; Schultz, Robert T.; Gaillard, William D.; Kenworthy, Lauren

2015-01-01

Autism spectrum disorder (ASD) is often associated with high levels of inflexible thinking and rigid behavior. The neural correlates of these behaviors have been investigated in adults and older adolescents, but not children. Prior studies utilized set-shifting tasks that engaged multiple levels of shifting, and depended on learning abstract rules and establishing a strong prepotent bias. These additional demands complicate simple interpretations of the results. We used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of set-shifting in 20 children (ages 7-14) with ASD and 19 typically developing, matched, control children. Participants completed a set-shifting task that minimized non-shifting task demands through the use of concrete instructions that provide spatial mapping of stimuli-responses. The shift/stay sets were given an equal number of trials to limit the prepotent bias. Both groups showed an equivalent ‘switch cost’, responding less accurately and slower to Switch stimuli than Stay stimuli, although the ASD group was less accurate overall. Both groups showed activation in prefrontal, striatal, parietal, and cerebellum regions known to govern effective set-shifts. Compared to controls, children with ASD demonstrated decreased activation of the right middle temporal gyrus across all trials, but increased activation in the mid-dorsal cingulate cortex/superior frontal gyrus, left middle frontal and right inferior frontal gyri during the Switch vs. Stay contrast. The successful behavioral switching performance of children with ASD comes at the cost of requiring greater engagement of frontal regions, suggesting less efficiency at this lowest level of shifting. PMID:25599972

Development of a Simulink Library for the Design, Testing and Simulation of Software Defined GPS Radios. With Application to the Development of Parallel Correlator Structures

DTIC Science & Technology

2014-05-01

function Value = Select_Element(Index,Signal) %# eml Value = Signal(Index); Code Listing 1 Code for Selector Block 12 | P a g e 4.3...code for the Simulink function shiftedSignal = fcn(signal,Shift) %# eml shiftedSignal = circshift(signal,Shift); Code Listing 2 Code for CircShift

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest ServiceFSavannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribedburn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relating changes inmore » urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.« less

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.« less

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.« less

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest ServiceFSavannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relating changesmore » in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.« less

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2008-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample size, this pilot study demonstrates that urinary MP concentrations may be effective biomarkers of occupational exposure to wood smoke among wildland firefighters.« less

Self-perceived origins of attitudes toward homosexuality.

PubMed

Hans, Jason D; Kersey, Megan; Kimberly, Claire

2012-01-01

Undergraduate students (N = 417) at a large southern university responded to open-ended questions designed to assess self-perceived origins of attitudes toward homosexuality and circumstances that may prompt a shift in attitudes. Inductively coded responses pointed to a positive correlation between attitudes toward homosexuality and experience interacting with gay men or lesbians; this is discussed in the context of Allport's (1954 ) contact hypothesis and Herek's (1984 , 1986 ) theory of functional attitudes. Implications are discussed for education and intervention efforts aimed at facilitating understanding and tolerance of gay men and lesbians.

Stuttering adults' lack of pre-speech auditory modulation normalizes when speaking with delayed auditory feedback.

PubMed

Daliri, Ayoub; Max, Ludo

2018-02-01

Auditory modulation during speech movement planning is limited in adults who stutter (AWS), but the functional relevance of the phenomenon itself remains unknown. We investigated for AWS and adults who do not stutter (AWNS) (a) a potential relationship between pre-speech auditory modulation and auditory feedback contributions to speech motor learning and (b) the effect on pre-speech auditory modulation of real-time versus delayed auditory feedback. Experiment I used a sensorimotor adaptation paradigm to estimate auditory-motor speech learning. Using acoustic speech recordings, we quantified subjects' formant frequency adjustments across trials when continually exposed to formant-shifted auditory feedback. In Experiment II, we used electroencephalography to determine the same subjects' extent of pre-speech auditory modulation (reductions in auditory evoked potential N1 amplitude) when probe tones were delivered prior to speaking versus not speaking. To manipulate subjects' ability to monitor real-time feedback, we included speaking conditions with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF). Experiment I showed that auditory-motor learning was limited for AWS versus AWNS, and the extent of learning was negatively correlated with stuttering frequency. Experiment II yielded several key findings: (a) our prior finding of limited pre-speech auditory modulation in AWS was replicated; (b) DAF caused a decrease in auditory modulation for most AWNS but an increase for most AWS; and (c) for AWS, the amount of auditory modulation when speaking with DAF was positively correlated with stuttering frequency. Lastly, AWNS showed no correlation between pre-speech auditory modulation (Experiment II) and extent of auditory-motor learning (Experiment I) whereas AWS showed a negative correlation between these measures. Thus, findings suggest that AWS show deficits in both pre-speech auditory modulation and auditory-motor learning; however, limited pre-speech modulation is not directly related to limited auditory-motor adaptation; and in AWS, DAF paradoxically tends to normalize their otherwise limited pre-speech auditory modulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides.

PubMed

Barnwal, Ravi Pratap; Rout, Ashok K; Chary, Kandala V R; Atreya, Hanudatta S

2007-12-01

We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides.

Ab initio calculation of the electronic absorption spectrum of liquid water

NASA Astrophysics Data System (ADS)

Martiniano, Hugo F. M. C.; Galamba, Nuno; Cabral, Benedito J. Costa

2014-04-01

The electronic absorption spectrum of liquid water was investigated by coupling a one-body energy decomposition scheme to configurations generated by classical and Born-Oppenheimer Molecular Dynamics (BOMD). A Frenkel exciton Hamiltonian formalism was adopted and the excitation energies in the liquid phase were calculated with the equation of motion coupled cluster with single and double excitations method. Molecular dynamics configurations were generated by different approaches. Classical MD were carried out with the TIP4P-Ew and AMOEBA force fields. The BLYP and BLYP-D3 exchange-correlation functionals were used in BOMD. Theoretical and experimental results for the electronic absorption spectrum of liquid water are in good agreement. Emphasis is placed on the relationship between the structure of liquid water predicted by the different models and the electronic absorption spectrum. The theoretical gas to liquid phase blue-shift of the peak positions of the electronic absorption spectrum is in good agreement with experiment. The overall shift is determined by a competition between the O-H stretching of the water monomer in liquid water that leads to a red-shift and polarization effects that induce a blue-shift. The results illustrate the importance of coupling many-body energy decomposition schemes to molecular dynamics configurations to carry out ab initio calculations of the electronic properties in liquid phase.

Narrative event boundaries, reading times, and expectation.

PubMed

Pettijohn, Kyle A; Radvansky, Gabriel A

2016-10-01

During text comprehension, readers create mental representations of the described events, called situation models. When new information is encountered, these models must be updated or new ones created. Consistent with the event indexing model, previous studies have shown that when readers encounter an event shift, reading times often increase. However, such increases are not consistently observed. This paper addresses this inconsistency by examining the extent to which reading-time differences observed at event shifts reflect an unexpectedness in the narrative rather than processes involved in model updating. In two reassessments of prior work, event shifts known to increase reading time were rated as less expected, and expectedness ratings significantly predicted reading time. In three new experiments, participants read stories in which an event shift was or was not foreshadowed, thereby influencing expectedness of the shift. Experiment 1 revealed that readers do not expect event shifts, but foreshadowing eliminates this. Experiment 2 showed that foreshadowing does not affect identification of event shifts. Finally, Experiment 3 found that, although reading times increased when an event shift was not foreshadowed, they were not different from controls when it was. Moreover, responses to memory probes were slower following an event shift regardless of foreshadowing, suggesting that situation model updating had taken place. Overall, the results support the idea that previously observed reading time increases at event shifts reflect, at least in part, a reader's unexpected encounter with a shift rather than an increase in processing effort required to update a situation model.

Wavelet filtered shifted phase-encoded joint transform correlation for face recognition

NASA Astrophysics Data System (ADS)

Moniruzzaman, Md.; Alam, Mohammad S.

2017-05-01

A new wavelet-filtered-based Shifted- phase-encoded Joint Transform Correlation (WPJTC) technique has been proposed for efficient face recognition. The proposed technique uses discrete wavelet decomposition for preprocessing and can effectively accommodate various 3D facial distortions, effects of noise, and illumination variations. After analyzing different forms of wavelet basis functions, an optimal method has been proposed by considering the discrimination capability and processing speed as performance trade-offs. The proposed technique yields better correlation discrimination compared to alternate pattern recognition techniques such as phase-shifted phase-encoded fringe-adjusted joint transform correlator. The performance of the proposed WPJTC has been tested using the Yale facial database and extended Yale facial database under different environments such as illumination variation, noise, and 3D changes in facial expressions. Test results show that the proposed WPJTC yields better performance compared to alternate JTC based face recognition techniques.

Visitor perceptions and the shifting social carrying capacity of South Sinai's coral reefs.

PubMed

Leujak, Wera; Ormond, Rupert F G

2007-04-01

To investigate how the perceptions and behaviour of visitors to coral reefs are influenced by their prior experience and knowledge of marine life, a questionnaire-based study was undertaken at sites in the Ras Mohammed National Park and at Sharm El Sheikh, South Sinai, Egypt. It was evident that over the 10-20 years during which these reefs have deteriorated (mainly due to reef-flat trampling), there have been interrelated shifts in the nature of visitors making use of them. First, there has been a shift from experienced divers and snorkellers to inexperienced snorkellers and non-snorkellers with a poorer knowledge of reef biology. Second, there has been a shift in the predominant nationalities of visitors, from German and British, through Italian, to Russian. More recent user groups both stated and showed that they had less experience of snorkelling; they also showed less knowledge of marine life and less interest in learning about it. Visitor perceptions of both the state of the marine life on the reefs and the acceptability of current visitor numbers also varied between groups. More recent visitor groups and visitors with less knowledge were more satisfied with reef health. In general, however, visitor perceptions of reef health did not correlate well with actual reef conditions, probably because more experienced visitors preferred less impacted sites with which they were nevertheless less satisfied than inexperienced visitors at heavily impacted sites. More recent visitor groups were also less bothered by crowding on the shore or in the water. Consequently, the apparent "social carrying capacity" of sites seems to be increasing to a level well above the likely "ecological carrying capacity".

Visitor Perceptions and the Shifting Social Carrying Capacity of South Sinai's Coral Reefs

NASA Astrophysics Data System (ADS)

Leujak, Wera; Ormond, Rupert F. G.

2007-04-01

To investigate how the perceptions and behaviour of visitors to coral reefs are influenced by their prior experience and knowledge of marine life, a questionnaire-based study was undertaken at sites in the Ras Mohammed National Park and at Sharm El Sheikh, South Sinai, Egypt. It was evident that over the 10-20 years during which these reefs have deteriorated (mainly due to reef-flat trampling), there have been interrelated shifts in the nature of visitors making use of them. First, there has been a shift from experienced divers and snorkellers to inexperienced snorkellers and non-snorkellers with a poorer knowledge of reef biology. Second, there has been a shift in the predominant nationalities of visitors, from German and British, through Italian, to Russian. More recent user groups both stated and showed that they had less experience of snorkelling; they also showed less knowledge of marine life and less interest in learning about it. Visitor perceptions of both the state of the marine life on the reefs and the acceptability of current visitor numbers also varied between groups. More recent visitor groups and visitors with less knowledge were more satisfied with reef health. In general, however, visitor perceptions of reef health did not correlate well with actual reef conditions, probably because more experienced visitors preferred less impacted sites with which they were nevertheless less satisfied than inexperienced visitors at heavily impacted sites. More recent visitor groups were also less bothered by crowding on the shore or in the water. Consequently, the apparent “social carrying capacity” of sites seems to be increasing to a level well above the likely “ecological carrying capacity”.

Event Boundaries Trigger Rapid Memory Reinstatement of the Prior Events to Promote Their Representation in Long-Term Memory.

PubMed

Sols, Ignasi; DuBrow, Sarah; Davachi, Lila; Fuentemilla, Lluís

2017-11-20

Although everyday experiences unfold continuously over time, shifts in context, or event boundaries, can influence how those events come to be represented in memory [1-4]. Specifically, mnemonic binding across sequential representations is more challenging at context shifts, such that successful temporal associations are more likely to be formed within than across contexts [1, 2, 5-9]. However, in order to preserve a subjective sense of continuity, it is important that the memory system bridge temporally adjacent events, even if they occur in seemingly distinct contexts. Here, we used pattern similarity analysis to scalp electroencephalographic (EEG) recordings during a sequential learning task [2, 3] in humans and showed that the detection of event boundaries triggered a rapid memory reinstatement of the just-encoded sequence episode. Memory reactivation was detected rapidly (∼200-800 ms from the onset of the event boundary) and was specific to context shifts that were preceded by an event sequence with episodic content. Memory reinstatement was not observed during the sequential encoding of events within an episode, indicating that memory reactivation was induced specifically upon context shifts. Finally, the degree of neural similarity between neural responses elicited during sequence encoding and at event boundaries correlated positively with participants' ability to later link across sequences of events, suggesting a critical role in binding temporally adjacent events in long-term memory. Current results shed light onto the neural mechanisms that promote episodic encoding not only for information within the event, but also, importantly, in the ability to link across events to create a memory representation of continuous experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

A meta-analysis including dose-response relationship between night shift work and the risk of colorectal cancer

PubMed Central

Wang, Xiao; Ji, Alin; Zhu, Yi; Liang, Zhen; Wu, Jian; Li, Shiqi; Meng, Shuai; Zheng, Xiangyi; Xie, Liping

2015-01-01

A meta-analysis was conducted to quantitatively evaluate the correlation between night shift work and the risk of colorectal cancer. We searched for publications up to March 2015 using PubMed, Web of Science, Cochrane Library, EMBASE and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles and relevant reviews were also checked. OR and 95% CI were used to assess the degree of the correlation between night shift work and risk of colorectal cancer via fixed- or random-effect models. A dose-response meta-analysis was performed as well. The pooled OR estimates of the included studies illustrated that night shift work was correlated with an increased risk of colorectal cancer (OR = 1.318, 95% CI 1.121–1.551). No evidence of publication bias was detected. In the dose-response analysis, the rate of colorectal cancer increased by 11% for every 5 years increased in night shift work (OR = 1.11, 95% CI 1.03–1.20). In conclusion, this meta-analysis indicated that night shift work was associated with an increased risk of colorectal cancer. Further researches should be conducted to confirm our findings and clarify the potential biological mechanisms. PMID:26208480

Normal mode and experimental analysis of TNT Raman spectrum

NASA Astrophysics Data System (ADS)

Liu, Yuemin; Perkins, Richard; Liu, Yucheng; Tzeng, Nianfeng

2017-04-01

In this study, a Raman spectrum of TNT was characterized through experiments and simulated using 22 hybrid density functional theory (DFT) methods. Among the different hybrid DFT methods, it was found that the most accurate simulation results of the Raman shift frequency were calculated by the O3LYP method. However, the deviations of the calculated Raman frequencies from the experimental value showed no dependency on the abilities of the DFT methods in recovering the correlation energy. The accuracies of the DFT methods in predicting the Raman bands are probably determined by the numerical grid and convergence criteria for optimizations of each DFT method. It was also decided that the prominent Raman shift 1362 cm-1 is mainly caused by symmetric stretching of the 4-nitro groups. Findings of this study can facilitate futuristic development of more effective surface enhanced Raman spectroscopy/scattering (SERS) substrates for explosive characterization and detection.

A comparison of the bonding in organoiron clusters

NASA Astrophysics Data System (ADS)

Buhl, Margaret L.; Long, Gary J.

1994-12-01

The Mössbauer effect hyperfine parameters and the results of the Fenske-Hall molecular orbit (mo) calculations have been used to study the electronic properties of trinuclear iron, tetranuclear iron butterfly, Fe-Co, and Fe-Cu carbonyl clusters. The more negative Fe charge and the larger Fe 4s population in an Fe(CO)4 fragment as compared with that in an Fe(CO)3 or an Fe(CO)2 fragment is a result of the CO ligands rather than the near-neighbor metals. The clusters which contain heterometals have more negative isomer shifts. The isomer shift correlated well with the sum of the Fe 4s orbital population and the Zeff these electrons experience. The mo wave functions and the atomic charges generally give a larger calculated Δ E Q than is observed, indicating the need to include Sternheimer factors in the calculation. The valence contribution dominates the EFG.

Effect of solvent hydrogen bonding on the photophysical properties of intramolecular charge transfer probe trans-ethyl p-(dimethylamino) cinamate and its derivative

NASA Astrophysics Data System (ADS)

Singh, T. Sanjoy; Moyon, N. S.; Mitra, Sivaprasad

2009-08-01

Intramolecular charge transfer (ICT) behavior of trans-ethyl p-(dimethylamino) cinamate (EDAC) and 4-(dimethylamino) cinnamic acid (DMACA) were studied by steady state absorption and emission, picosecond time-resolved fluorescence experiments in various pure and mixed solvent systems. The large fluorescence spectral shift in more polar solvents indicates an efficient charge transfer from the donor site to the acceptor moiety in the excited state compared to the ground state. The energy for 0,0 transition ( ν0,0) for EDAC shows very good linear correlation with static solvent dielectric property; however, fluorescence emission maximum, stokes shift and fluorescence quantum yield show significant deviation from linearity in polar protic solvents, indicating a large contribution of solvent hydrogen bonding on the excited state relaxation mechanism. A quantitative estimation of contribution from different solvatochromic parameters was made using linear free energy relationship based on Kamlet-Taft equation.

Spin-orbit effects on the (119)Sn magnetic-shielding tensor in solids: a ZORA/DFT investigation.

PubMed

Alkan, Fahri; Holmes, Sean T; Iuliucci, Robbie J; Mueller, Karl T; Dybowski, Cecil

2016-07-28

Periodic-boundary and cluster calculations of the magnetic-shielding tensors of (119)Sn sites in various co-ordination and stereochemical environments are reported. The results indicate a significant difference between the predicted NMR chemical shifts for tin(ii) sites that exhibit stereochemically-active lone pairs and tin(iv) sites that do not have stereochemically-active lone pairs. The predicted magnetic shieldings determined either with the cluster model treated with the ZORA/Scalar Hamiltonian or with the GIPAW formalism are dependent on the oxidation state and the co-ordination geometry of the tin atom. The inclusion of relativistic effects at the spin-orbit level removes systematic differences in computed magnetic-shielding parameters between tin sites of differing stereochemistries, and brings computed NMR shielding parameters into significant agreement with experimentally-determined chemical-shift principal values. Slight improvement in agreement with experiment is noted in calculations using hybrid exchange-correlation functionals.

UV-Vis absorption spectra and electronic structure of merocyanines in the gas phase

NASA Astrophysics Data System (ADS)

Ishchenko, Alexander A.; Kulinich, Andrii V.; Bondarev, Stanislav L.; Raichenok, Tamara F.

2018-02-01

Gas-phase absorption spectra of a merocyanine vinylogous series have been studied for the first time. In vapour, their long-wavelength absorption bands were found to be considerably shifted hypsochromically, broader, more symmetrical, less intense, and their vinylene shift much smaller than even in low-polarity n-hexane. This indicates that in the gas phase their electronic structure closely approaches the nonpolar polyene limiting structure. The TDDFT calculations of the long-wavelength electronic transitions in the studied merocyanines in vacuo demonstrated good-to-excellent correlation - depending on the functional used - with the obtained experimental data. For comparison, the solvent effects was accounted for using the polarizable continuum model (PCM) with n-hexane and ethanol as low-polarity and high-polarity media, and compared with the UV-Vis spectral data in these solvents. In this case, the discrepancy between theory and experiment was much greater, increasing at that with the polymethine chain length.

Momentum-resolved spectroscopy of a Fermi liquid

PubMed Central

Doggen, Elmer V. H.; Kinnunen, Jami J.

2015-01-01

We consider a recent momentum-resolved radio-frequency spectroscopy experiment, in which Fermi liquid properties of a strongly interacting atomic Fermi gas were studied. Here we show that by extending the Brueckner-Goldstone model, we can formulate a theory that goes beyond basic mean-field theories and that can be used for studying spectroscopies of dilute atomic gases in the strongly interacting regime. The model hosts well-defined quasiparticles and works across a wide range of temperatures and interaction strengths. The theory provides excellent qualitative agreement with the experiment. Comparing the predictions of the present theory with the mean-field Bardeen-Cooper-Schrieffer theory yields insights into the role of pair correlations, Tan's contact, and the Hartree mean-field energy shift. PMID:25941948

Estimation bias from using nonlinear Fourier plane correlators for sub-pixel image shift measurement and implications for the binary joint transform correlator

NASA Astrophysics Data System (ADS)

Grycewicz, Thomas J.; Florio, Christopher J.; Franz, Geoffrey A.; Robinson, Ross E.

2007-09-01

When using Fourier plane digital algorithms or an optical correlator to measure the correlation between digital images, interpolation by center-of-mass or quadratic estimation techniques can be used to estimate image displacement to the sub-pixel level. However, this can lead to a bias in the correlation measurement. This bias shifts the sub-pixel output measurement to be closer to the nearest pixel center than the actual location. The paper investigates the bias in the outputs of both digital and optical correlators, and proposes methods to minimize this effect. We use digital studies and optical implementations of the joint transform correlator to demonstrate optical registration with accuracies better than 0.1 pixels. We use both simulations of image shift and movies of a moving target as inputs. We demonstrate bias error for both center-of-mass and quadratic interpolation, and discuss the reasons that this bias is present. Finally, we suggest measures to reduce or eliminate the bias effects. We show that when sub-pixel bias is present, it can be eliminated by modifying the interpolation method. By removing the bias error, we improve registration accuracy by thirty percent.

Contribution of the frontal eye field to gaze shifts in the head-unrestrained rhesus monkey: neuronal activity.

PubMed

Knight, T A

2012-12-06

The frontal eye field (FEF) has a strong influence on saccadic eye movements with the head restrained. With the head unrestrained, eye saccades combine with head movements to produce large gaze shifts, and microstimulation of the FEF evokes both eye and head movements. To test whether the dorsomedial FEF provides commands for the entire gaze shift or its separate eye and head components, we recorded extracellular single-unit activity in monkeys trained to make large head-unrestrained gaze shifts. We recorded 80 units active during gaze shifts, and closely examined 26 of these that discharged a burst of action potentials that preceded horizontal gaze movements. These units were movement or visuomovement related and most exhibited open movement fields with respect to amplitude. To reveal the relations of burst parameters to gaze, eye, and/or head movement metrics, we used behavioral dissociations of gaze, eye, and head movements and linear regression analyses. The burst number of spikes (NOS) was strongly correlated with movement amplitude and burst temporal parameters were strongly correlated with movement temporal metrics for eight gaze-related burst neurons and five saccade-related burst neurons. For the remaining 13 neurons, the NOS was strongly correlated with the head movement amplitude, but burst temporal parameters were most strongly correlated with eye movement temporal metrics (head-eye-related burst neurons, HEBNs). These results suggest that FEF units do not encode a command for the unified gaze shift only; instead, different units may carry signals related to the overall gaze shift or its eye and/or head components. Moreover, the HEBNs exhibit bursts whose magnitude and timing may encode a head displacement signal and a signal that influences the timing of the eye saccade, thereby serving as a mechanism for coordinating the eye and head movements of a gaze shift. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

From sedentary to active school commute: Multi-level factors associated with travel mode shifts.

PubMed

Lee, Chanam; Yoon, Jeongjae; Zhu, Xuemei

2017-02-01

Previous research has examined personal, social, and environmental correlates of active commuting to school, but most were cross-sectional and mode choice studies. This exploratory case study utilized a retrospective natural experiment opportunity, where a group of students transferred to a new school, and therefore experienced changes in their home-to-school travel environments. It examined whether such changes led to mode shifts from sedentary (car or school bus) to active (walking and bicycling) and what factors were associated with those shifts. Retrospective parental survey data (n=165, response rate=46%) were collected in 2011 from a new elementary school that opened in 2010 in Austin, Texas. The survey asked about the child's school travel mode and parental perceptions of home-to-school travel environments before and after the transfer, as well as personal and social factors. Multivariate logistic regressions were used to predict the odds of shifting from sedentary to active modes, using personal, social, and physical environmental variables. Sixty-eight (41.2%) respondents reported a sedentary-to-active mode shift for school commuting. Such shifts were associated with changes in school travel environments (e.g., shorter travel distance, improved safety, and decreased availability of bike lanes/paths) and relevant programs/services (e.g., increase in walking-promotion programs, and decrease in school bus service due to shortened distances). Targeting the current sedentary mode users is important to bring health benefits through increased physical activity and environmental benefits from reduced automobile use. Sedentary-to-active mode shifts may be encouraged by providing walking-promotion programs and by reducing travel distances and safety threats en route to school. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C

NASA Astrophysics Data System (ADS)

Stefanikova, E.; Frassinetti, L.; Saarelma, S.; Loarte, A.; Nunes, I.; Garzotti, L.; Lomas, P.; Rimini, F.; Drewelow, P.; Kruezi, U.; Lomanowski, B.; de la Luna, E.; Meneses, L.; Peterka, M.; Viola, B.; Giroud, C.; Maggi, C.; contributors, JET

2018-05-01

The electron temperature and density pedestals tend to vary in their relative radial positions, as observed in DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) and ASDEX Upgrade (Dunne et al 2017 Plasma Phys. Control. Fusion 59 14017). This so-called relative shift has an impact on the pedestal magnetohydrodynamic (MHD) stability and hence on the pedestal height (Osborne et al 2015 Nucl. Fusion 55 063018). The present work studies the effect of the relative shift on pedestal stability of JET ITER-like wall (JET-ILW) baseline low triangularity (δ) unseeded plasmas, and similar JET-C discharges. As shown in this paper, the increase of the pedestal relative shift is correlated with the reduction of the normalized pressure gradient, therefore playing a strong role in pedestal stability. Furthermore, JET-ILW tends to have a larger relative shift compared to JET carbon wall (JET-C), suggesting a possible role of the plasma facing materials in affecting the density profile location. Experimental results are then compared with stability analysis performed in terms of the peeling-ballooning model and with pedestal predictive model EUROPED (Saarelma et al 2017 Plasma Phys. Control. Fusion). Stability analysis is consistent with the experimental findings, showing an improvement of the pedestal stability, when the relative shift is reduced. This has been ascribed mainly to the increase of the edge bootstrap current, and to minor effects related to the increase of the pedestal pressure gradient and narrowing of the pedestal pressure width. Pedestal predictive model EUROPED shows a qualitative agreement with experiment, especially for low values of the relative shift.

Optical-Correlator Neural Network Based On Neocognitron

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin; Stoner, William W.

1994-01-01

Multichannel optical correlator implements shift-invariant, high-discrimination pattern-recognizing neural network based on paradigm of neocognitron. Selected as basic building block of this neural network because invariance under shifts is inherent advantage of Fourier optics included in optical correlators in general. Neocognitron is conceptual electronic neural-network model for recognition of visual patterns. Multilayer processing achieved by iteratively feeding back output of feature correlator to input spatial light modulator and updating Fourier filters. Neural network trained by use of characteristic features extracted from target images. Multichannel implementation enables parallel processing of large number of selected features.

Spatial reorientation experiments for NMR of solids and partially oriented liquids.

PubMed

Martin, Rachel W; Kelly, John E; Collier, Kelsey A

2015-11-01

Motional reorientation experiments are extensions of Magic Angle Spinning (MAS) where the rotor axis is changed in order to average out, reintroduce, or scale anisotropic interactions (e.g. dipolar couplings, quadrupolar interactions or chemical shift anisotropies). This review focuses on Variable Angle Spinning (VAS), Switched Angle Spinning (SAS), and Dynamic Angle Spinning (DAS), all of which involve spinning at two or more different angles sequentially, either in successive experiments or during a multidimensional experiment. In all of these experiments, anisotropic terms in the Hamiltonian are scaled by changing the orientation of the spinning sample relative to the static magnetic field. These experiments vary in experimental complexity and instrumentation requirements. In VAS, many one-dimensional spectra are collected as a function of spinning angle. In SAS, dipolar couplings and/or chemical shift anisotropies are reintroduced by switching the sample between two different angles, often 0° or 90° and the magic angle, yielding a two-dimensional isotropic-anisotropic correlation spectrum. Dynamic Angle Spinning (DAS) is a related experiment that is used to simultaneously average out the first- and second-order quadrupolar interactions, which cannot be accomplished by spinning at any unique rotor angle in physical space. Although motional reorientation experiments generally require specialized instrumentation and data analysis schemes, some are accessible with only minor modification of standard MAS probes. In this review, the mechanics of each type of experiment are described, with representative examples. Current and historical probe and coil designs are discussed from the standpoint of how each one accomplishes the particular objectives of the experiment(s) it was designed to perform. Finally, applications to inorganic materials and liquid crystals, which present very different experimental challenges, are discussed. The review concludes with perspectives on how motional reorientation experiments can be applied to current problems in chemistry, molecular biology, and materials science, given the many advances in high-field NMR magnets, fast spinning, and sample preparation realized in recent years. Copyright © 2015 Elsevier B.V. All rights reserved.

Circadian type, chronic fatigue, and serum IgM in the shift workers of an industrial organization

PubMed Central

Khaleghipour, Shahnaz; Masjedi, Mohsen; Kelishadi, Roya

2015-01-01

Background: Night shift workers are more vulnerable to immune-related diseases. Immunoglobulin M (IgM) is a potent activator of complement, and complement has a crucial role in defense against bacterial infections. Circadian type is known as an effective agent on vulnerability and adaptation with shift work due to non-compliance with shift stress. The objective of this study was to investigate the correlation of circadian type and chronic fatigue with the serum concentration of IgM in a group of shift workers. Materials and Methods: This cross-sectional study was performed in an industrial organization in Isfahan, Iran. The study population consisted of 221 male employees working at night shifts who were selected by random cluster sampling. The following questionnaires were used: composite morningness (Torsvall and Akerstedt), circadian type (Folkard), and chronic fatigue (Barton and colleagues). The serum concentration of IgM was measured by the nephelometric method. The data were analyzed with the Pearson coefficient correlation and the path analysis for finding the pattern of the structural equations to evaluate the direct and indirect relationships between variables, using the SPSS 15 and LISREL 8.5 statistical software. Results: Significant correlation was documented between morningness, flexibility, languidness, and chronic fatigue with the serum concentration of IgM (P < 0.01). Conclusion: The results showed that the shift workers with morningness and languidness experienced more problems during the working hours due to more tiredness, and had decreased serum concentration of IgM. Correct management of shift work may attenuate fatigue in workers and also improve many health issues experienced by the shift workers. PMID:25802830

Relationships between the center of pressure and the movements of the ankle and knee joints during the stance phase in patients with severe medial knee osteoarthritis.

PubMed

Fukaya, Takashi; Mutsuzaki, Hirotaka; Okubo, Tomoyuki; Mori, Koichi; Wadano, Yasuyoshi

2016-08-01

The knee joint movement during the stance phase is affected by altered ankle movement and the center of pressure (COP). However the relationships between changes in the center of pressure (COP) and the altered kinematics and kinetics of the ankle and knee joints in patients with osteoarthritis (OA) of the knee are not well understood. The purpose of this study was to determine the relationships between changes in the COP and the altered kinematic and kinetic variables in ankle and knee joints during the stance phase in patients with medial knee OA. Fourteen patients with knee OA (21 knees) and healthy subjects were assessed by gait analysis using an eight-camera motion analysis system to record forward and lateral shifts in the COP and the angle and net internal moments of the knee and ankle joint. Spearman rank-correlation coefficients were used to determine the relationship between these results. In knees with medial OA, lateral shifts in the COP were correlated with knee flexion angle. Lateral shifts in the COP were correlated with the second peak of the knee extensor moment and correlated with the knee abductor moment. In patients with medial knee OA, lateral shifts in the COP were negatively correlated with the kinematic and kinetic variables in the sagittal plane of the knee joints. Controlling such lateral shifts in the COP may thus be an effective intervention for mechanical loads on the knee during the stance phase in patients with knee OA. Copyright © 2016 Elsevier B.V. All rights reserved.

Coral-macroalgal phase shifts or reef resilience: links with diversity and functional roles of herbivorous fishes on the Great Barrier Reef

NASA Astrophysics Data System (ADS)

Cheal, A. J.; MacNeil, M. Aaron; Cripps, E.; Emslie, M. J.; Jonker, M.; Schaffelke, B.; Sweatman, H.

2010-12-01

Changes from coral to macroalgal dominance following disturbances to corals symbolize the global degradation of coral reefs. The development of effective conservation measures depends on understanding the causes of such phase shifts. The prevailing view that coral-macroalgal phase shifts commonly occur due to insufficient grazing by fishes is based on correlation with overfishing and inferences from models and small-scale experiments rather than on long-term quantitative field studies of fish communities at affected and resilient sites. Consequently, the specific characteristics of herbivorous fish communities that most promote reef resilience under natural conditions are not known, though this information is critical for identifying vulnerable ecosystems. In this study, 11 years of field surveys recorded the development of the most persistent coral-macroalgal phase shift (>7 years) yet observed on Australia’s Great Barrier Reef (GBR). This shift followed extensive coral mortality caused by thermal stress (coral bleaching) and damaging storms. Comparisons with two similar reefs that suffered similar disturbances but recovered relatively rapidly demonstrated that the phase shift occurred despite high abundances of one herbivore functional group (scraping/excavating parrotfishes: Labridae). However, the shift was strongly associated with low fish herbivore diversity and low abundances of algal browsers (predominantly Siganidae) and grazers/detritivores (Acanthuridae), suggesting that one or more of these factors underpin reef resilience and so deserve particular protection. Herbivorous fishes are not harvested on the GBR, and the phase shift was not enhanced by unusually high nutrient levels. This shows that unexploited populations of herbivorous fishes cannot ensure reef resilience even under benign conditions and suggests that reefs could lose resilience under relatively low fishing pressure. Predictions of more severe and widespread coral mortality due to global climate change emphasize the need for more effective identification and protection of ecosystem components that are critical for the prevention of coral reef phase shifts.

Neural Correlates of Set-Shifting in Children With Autism.

PubMed

Yerys, Benjamin E; Antezana, Ligia; Weinblatt, Rachel; Jankowski, Kathryn F; Strang, John; Vaidya, Chandan J; Schultz, Robert T; Gaillard, William D; Kenworthy, Lauren

2015-08-01

Autism spectrum disorder (ASD) is often associated with high levels of inflexible thinking and rigid behavior. The neural correlates of these behaviors have been investigated in adults and older adolescents, but not children. Prior studies utilized set-shifting tasks that engaged multiple levels of shifting, and depended on learning abstract rules and establishing a strong prepotent bias. These additional demands complicate simple interpretations of the results. We used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of set-shifting in 20 children (ages 7-14) with ASD and 19 typically developing, matched, control children. Participants completed a set-shifting task that minimized nonshifting task demands through the use of concrete instructions that provide spatial mapping of stimuli-responses. The shift/stay sets were given an equal number of trials to limit the prepotent bias. Both groups showed an equivalent "switch cost," responding less accurately and slower to Switch stimuli than Stay stimuli, although the ASD group was less accurate overall. Both groups showed activation in prefrontal, striatal, parietal, and cerebellum regions known to govern effective set-shifts. Compared to controls, children with ASD demonstrated decreased activation of the right middle temporal gyrus across all trials, but increased activation in the mid-dorsal cingulate cortex/superior frontal gyrus, left middle frontal, and right inferior frontal gyri during the Switch vs. Stay contrast. The successful behavioral switching performance of children with ASD comes at the cost of requiring greater engagement of frontal regions, suggesting less efficiency at this lowest level of shifting. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Hybrid Theory of P-Wave Electron-Hydrogen Elastic Scattering

NASA Technical Reports Server (NTRS)

Bhatia, Anand

2012-01-01

We report on a study of electron-hydrogen scattering, using a combination of a modified method of polarized orbitals and the optical potential formalism. The calculation is restricted to P waves in the elastic region, where the correlation functions are of Hylleraas type. It is found that the phase shifts are not significantly affected by the modification of the target function by a method similar to the method of polarized orbitals and they are close to the phase shifts calculated earlier by Bhatia. This indicates that the correlation function is general enough to include the target distortion (polarization) in the presence of the incident electron. The important fact is that in the present calculation, to obtain similar results only 35-term correlation function is needed in the wave function compared to the 220-term wave function required in the above-mentioned previous calculation. Results for the phase shifts, obtained in the present hybrid formalism, are rigorous lower bounds to the exact phase shifts.

Approximating the Shifted Hartree-Exchange-Correlation Potential in Direct Energy Kohn-Sham Theory.

PubMed

Sharpe, Daniel J; Levy, Mel; Tozer, David J

2018-02-13

Levy and Zahariev [Phys. Rev. Lett. 113 113002 (2014)] have proposed a new approach for performing density functional theory calculations, termed direct energy Kohn-Sham (DEKS) theory. In this approach, the electronic energy equals the sum of orbital energies, obtained from Kohn-Sham-like orbital equations involving a shifted Hartree-exchange-correlation potential, which must be approximated. In the present study, density scaling homogeneity considerations are used to facilitate DEKS calculations on a series of atoms and molecules, leading to three nonlocal approximations to the shifted potential. The first two rely on preliminary Kohn-Sham calculations using a standard generalized gradient approximation (GGA) exchange-correlation functional and the results illustrate the benefit of describing the dominant Hartree component of the shift exactly. A uniform electron gas analysis is used to eliminate the need for these preliminary Kohn-Sham calculations, leading to a potential with an unconventional form that yields encouraging results, providing strong motivation for further research in DEKS theory.

Distribution of mean Doppler shift, spectral width, and skewness of coherent 50-MHz auroral radar backscatter

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

Watermann, J.; McNamara, A.G.; Sofko, G.J.

Some 7,700 radio aurora spectra obtained from a six link 50-MHz CW radar network set up on the Canadian prairies were analyzed with respect to the distributions of mean Doppler shift, spectral width and skewness. A comparison with recently published SABRE results obtained at 153 MHz shows substantial differences in the distributions which are probably due to different experimental and geophysical conditions. The spectra are mostly broad with mean Doppler shifts close to zero (type II spectra). The typical groupings of type I and type III spectra are clearly identified. All types appear to be in general much more symmetricmore » than those recorded with SABRE, and the skewness is only weakly dependent on the sign of the mean Doppler shift. Its distribution peaks near zero and shows a weak positive correlation with the type II Doppler shifts while the mostly positive type I Doppler shifts are slightly negatively correlated with the skewness.« less

Impact of missing data on the efficiency of homogenisation: experiments with ACMANTv3

NASA Astrophysics Data System (ADS)

Domonkos, Peter; Coll, John

2018-04-01

The impact of missing data on the efficiency of homogenisation with ACMANTv3 is examined with simulated monthly surface air temperature test datasets. The homogeneous database is derived from an earlier benchmarking of daily temperature data in the USA, and then outliers and inhomogeneities (IHs) are randomly inserted into the time series. Three inhomogeneous datasets are generated and used, one with relatively few and small IHs, another one with IHs of medium frequency and size, and a third one with large and frequent IHs. All of the inserted IHs are changes to the means. Most of the IHs are single sudden shifts or pair of shifts resulting in platform-shaped biases. Each test dataset consists of 158 time series of 100 years length, and their mean spatial correlation is 0.68-0.88. For examining the impacts of missing data, seven experiments are performed, in which 18 series are left complete, while variable quantities (10-70%) of the data of the other 140 series are removed. The results show that data gaps have a greater impact on the monthly root mean squared error (RMSE) than the annual RMSE and trend bias. When data with a large ratio of gaps is homogenised, the reduction of the upper 5% of the monthly RMSE is the least successful, but even there, the efficiency remains positive. In terms of reducing the annual RMSE and trend bias, the efficiency is 54-91%. The inclusion of short and incomplete series with sufficient spatial correlation in all cases improves the efficiency of homogenisation with ACMANTv3.

Posttraining intraamygdala infusions of oxotremorine and propranolol modulate storage of memory for reductions in reward magnitude.

PubMed

Salinas, J A; Introini-Collison, I B; Dalmaz, C; McGaugh, J L

1997-07-01

These experiments examined the effects of posttraining intraamygdala administration of the muscarinic agonist, oxotremorine, and the beta-noradrenergic antagonist, propranolol, on memory for reduction in reward magnitude. Male Sprague-Dawley rats (175-200 g) implanted with bilateral intraamygdala cannulae were food deprived (maintained at 80% of body weight) and trained to run a straight alley (six trials/day) for either ten 45-mg food pellets (high reward) or one 45-mg food pellet (low reward) for 10 days. In Experiment One, the animals in the high-reward group were than shifted to a one-pellet reward and immediately given intraamygdala infusions (0.5 microliter/side) of either oxotremorine (10 ng) or phosphate buffer. Shifted training continued for 4 more days and no further injections were given. Shifted animals given the buffer solution displayed an increase in runway latencies but returned to preshift latencies by the fifth day of shifted training. In contrast, animals given oxotremorine exhibited increased latencies through the fifth day. In Experiment Two, rats were trained as in Experiment. One but immediately following the shift received intraamygdala infusions of oxotremorine (10 ng), propranolol (0.3 microgram), both, or phosphate buffer. Shifted vehicle-injected rats returned to preshift performance by the fifth day of shifted training. Shifted propranolol rats returned to preshift latencies by the third day of shifted training. In contrast, the shifted oxotremorine and the shifted oxotremorine/propranolol rats displayed longer latencies than unshifted controls through 5 days of shifted training. The findings indicate that the muscarinic cholinergic and beta-noradrenergic systems within the amygdala interact in regulating memory and support the view that noradrenergic influences are mediated through cholinergic activation.

A Novel Multiple-Access Correlation-Delay-Shift-Keying

NASA Astrophysics Data System (ADS)

Duan, J. Y.; Jiang, G. P.; Yang, H.

In Correlation-Delay-Shift-Keying (CDSK), the reference signal and the information-bearing signal are added together during a certain time delay. Because the reference signal is not strictly orthogonal to the information-bearing signal, the cross-correlation between the adjacent chaotic signal (Intra-signal Interference, ISI) will be introduced into the demodulation at the receiver. Therefore, the Bit-Error Ratio (BER) of CDSK is higher than that of Differential-Chaos-Shift-Keying (DCSK). To avoid the ISI component and enhance the BER performance of CDSK in multiuser scenario, Multiple-Access CDSK with No Intra-signal Interference (MA-CDSK-NII) is proposed. By constructing the repeated chaotic generator and applying the Walsh code sequence to modulate the reference signal, in MA-CDSK-NII, the ISI component will be eliminated during the demodulation. Gaussian approximation method is adopted here to obtain the exact performance analysis of MA-CDSK-NII over additive white Gaussian noise (AWGN) channel and Rayleigh multipath fading channels. Results show that, due to no ISI component and lower transmitting power, the BER performance of MA-CDSK-NII can be better than that of multiple-access CDSK and Code-Shifted Differential-Chaos-Shift-Keying (CS-DCSK).

The effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses.

PubMed

Dehghan, Habibollah; Azmoon, Hiva; Souri, Shiva; Akbari, Jafar

2014-01-01

Psychological problems as state anxiety (SA) in the work environment has negative effect on the employees life especially shift work nurses, i.e. negative effect on mental and physical health (sleep quality, eye fatigue and comfort thermal). The purpose of this study was determination of effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses. This cross-sectional research conducted on 82 shift-work personnel of 18 nursing workstations of Isfahan hospitals in 2012. To measure the SA, sleep quality, visual fatigue and thermal comfort, Spielberger state-trait anxiety inventory, Pittsburg sleep quality index, eye fatigue questionnaire and thermal comfort questionnaire were used respectively. The data were analyzed with descriptive statistics, student test and correlation analysis. Correlation between SA and sleep quality was -0.664(P < 0001), Pearson correlation between SA and thermal comfort was -0.276(P = 0.016) and between SA and eye fatigue was 0.57 (P < 0001). Based on these results, it can be concluded that improvement of thermal conditions and reduce state anxiety level can be reduce eye fatigue and increase the sleep quality in shift work nurses.

The effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses

PubMed Central

Dehghan, Habibollah; Azmoon, Hiva; Souri, Shiva; Akbari, Jafar

2014-01-01

Psychological problems as state anxiety (SA) in the work environment has negative effect on the employees life especially shift work nurses, i.e. negative effect on mental and physical health (sleep quality, eye fatigue and comfort thermal). The purpose of this study was determination of effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses. Methods: This cross-sectional research conducted on 82 shift-work personnel of 18 nursing workstations of Isfahan hospitals in 2012. To measure the SA, sleep quality, visual fatigue and thermal comfort, Spielberger state-trait anxiety inventory, Pittsburg sleep quality index, eye fatigue questionnaire and thermal comfort questionnaire were used respectively. The data were analyzed with descriptive statistics, student test and correlation analysis. Results: Correlation between SA and sleep quality was −0.664(P < 0001), Pearson correlation between SA and thermal comfort was −0.276(P = 0.016) and between SA and eye fatigue was 0.57 (P < 0001). Conclusion: Based on these results, it can be concluded that improvement of thermal conditions and reduce state anxiety level can be reduce eye fatigue and increase the sleep quality in shift work nurses. PMID:25077165

Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C,15N-labeled peptides and proteins.

PubMed

Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

2010-03-01

In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly (13)C,(15)N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i-2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Accurate and fiducial-marker-free correction for three-dimensional chromatic shift in biological fluorescence microscopy.

PubMed

Matsuda, Atsushi; Schermelleh, Lothar; Hirano, Yasuhiro; Haraguchi, Tokuko; Hiraoka, Yasushi

2018-05-15

Correction of chromatic shift is necessary for precise registration of multicolor fluorescence images of biological specimens. New emerging technologies in fluorescence microscopy with increasing spatial resolution and penetration depth have prompted the need for more accurate methods to correct chromatic aberration. However, the amount of chromatic shift of the region of interest in biological samples often deviates from the theoretical prediction because of unknown dispersion in the biological samples. To measure and correct chromatic shift in biological samples, we developed a quadrisection phase correlation approach to computationally calculate translation, rotation, and magnification from reference images. Furthermore, to account for local chromatic shifts, images are split into smaller elements, for which the phase correlation between channels is measured individually and corrected accordingly. We implemented this method in an easy-to-use open-source software package, called Chromagnon, that is able to correct shifts with a 3D accuracy of approximately 15 nm. Applying this software, we quantified the level of uncertainty in chromatic shift correction, depending on the imaging modality used, and for different existing calibration methods, along with the proposed one. Finally, we provide guidelines to choose the optimal chromatic shift registration method for any given situation.

Correlation of 3D Shift and 3D Tilt of the Patella in Patients With Recurrent Dislocation of the Patella and Healthy Volunteers: An In Vivo Analysis Based on 3-Dimensional Computer Models.

PubMed

Yamada, Yuzo; Toritsuka, Yukiyoshi; Nakamura, Norimasa; Horibe, Shuji; Sugamoto, Kazuomi; Yoshikawa, Hideki; Shino, Konsei

2017-11-01

The concepts of lateral deviation and lateral inclination of the patella, characterized as shift and tilt, have been applied in combination to evaluate patellar malalignment in patients with patellar dislocation. It is not reasonable, however, to describe the 3-dimensional (3D) positional relation between the patella and the femur according to measurements made on 2-dimensional (2D) images. The current study sought to clarify the relation between lateral deviation and inclination of the patella in patients with recurrent dislocation of the patella (RDP) by redefining them via 3D computer models as 3D shift and 3D tilt. Descriptive laboratory study. Altogether, 60 knees from 56 patients with RDP and 15 knees from 10 healthy volunteers were evaluated. 3D shift and tilt of the patella were analyzed with 3D computer models created by magnetic resonance imaging scans obtained at 10° intervals of knee flexion (0°-50°). 3D shift was defined as the spatial distance between the patellar reference point and the midsagittal plane of the femur; it is expressed as a percentage of the interepicondylar width. 3D tilt was defined as the spatial angle between the patellar reference plane and the transepicondylar axis. Correlations between the 2 parameters were assessed with the Pearson correlation coefficient. The patients' mean Pearson correlation coefficient was 0.895 ± 0.186 (range, -0.073 to 0.997; median, 0.965). In all, 56 knees (93%) had coefficients >0.7 (strong correlation); 1 knee (2%), >0.4 (moderate correlation); 2 knees (3%), >0.2 (weak correlation); and 1 knee (2%), <0.2 (no correlation). The mean correlation coefficient of the healthy volunteers was 0.645 ± 0.448 (range, -0.445 to 0.982; median, 0.834). A statistically significant difference was found in the distribution of the correlation coefficients between the patients and the healthy volunteers ( P = .0034). When distribution of the correlation coefficients obtained by the 3D analyses was compared with that by the 2D (conventional) analyses, based on the bisect offset index and patellar tilt angle, the 3D analyses showed statistically higher correlations between the lateral deviation and inclination of the patella ( P < .01). 3D shift and 3D tilt of the patella were moderately or strongly correlated in 95% of patients with RDP at 0° to 50° of knee flexion. It is not always necessary to use both parameters when evaluating patellar alignment, at least for knees with RDP at 0° to 50° of flexion. Such a description may enable surgeons to describe patellar alignment more simply, leading to a better, easier understanding of the characteristics of each patient with RDP.

Phytoplankton Cell Size: Intra- and Interspecific Effects of Warming and Grazing

PubMed Central

Peter, Kalista Higini; Sommer, Ulrich

2012-01-01

Decreasing body size has been suggested as the third universal biological response to global warming after latitudinal/altitudinal range shifts and shifts in phenology. Size shifts in a community can be the composite result of intraspecific size shifts and of shifts between differently sized species. Metabolic explanations for the size shifts dominate in the literature but top down effects, i.e. intensified size-selective consumption at higher temperatures, have been proposed as alternative explanation. Therefore, we performed phytoplankton experiments with a factorial combination of warming and consumer type (protist feeding mainly on small algae vs. copepods mainly feeding on large algae). Natural phytoplankton was exposed to 3 (1st experiment) or 4 (2nd experiment) temperature levels and 3 (1st experiment: nano-, microzooplankton, copepods) or 2 (2nd experiment: microzooplankton, copepods) types of consumers. Size shifts of individual phytoplankton species and community mean size were analyzed. Both, mean cell size of most of the individual species and mean community cell size decreased with temperature under all grazing regimes. Grazing by copepods caused an additional reduction in cell size. Our results reject the hypothesis, that intensified size selective consumption at higher temperature would be the dominant explanation of decreasing body size. In this case, the size reduction would have taken place only in the copepod treatments but not in the treatments with protist grazing (nano- and microzooplankton). PMID:23226215

Strength-based criterion shifts in recognition memory.

PubMed

Singer, Murray

2009-10-01

In manipulations of stimulus strength between lists, a more lenient signal detection criterion is more frequently applied to a weak than to a strong stimulus class. However, with randomly intermixed weak and strong test probes, such a criterion shift often does not result. A procedure that has yielded delay-based within-list criterion shifts was applied to strength manipulations in recognition memory for categorized word lists. When participants made semantic ratings about each stimulus word, strength-based criterion shifts emerged regardless of whether words from pairs of categories were studied in separate blocks (Experiment 1) or in intermixed blocks (Experiment 2). In Experiment 3, the criterion shift persisted under the semantic-rating study task, but not under rote memorization. These findings suggest that continually adjusting the recognition decision criterion is cognitively feasible. They provide a technique for manipulating the criterion shift, and they identify competing theoretical accounts of these effects.

Unsupervised parameter optimization for automated retention time alignment of severely shifted gas chromatographic data using the piecework alignment algorithm.

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

Pierce, Karisa M.; Wright, Bob W.; Synovec, Robert E.

2007-02-02

First, simulated chromatographic separations with declining retention time precision were used to study the performance of the piecewise retention time alignment algorithm and to demonstrate an unsupervised parameter optimization method. The average correlation coefficient between the first chromatogram and every other chromatogram in the data set was used to optimize the alignment parameters. This correlation method does not require a training set, so it is unsupervised and automated. This frees the user from needing to provide class information and makes the alignment algorithm more generally applicable to classifying completely unknown data sets. For a data set of simulated chromatograms wheremore » the average chromatographic peak was shifted past two neighboring peaks between runs, the average correlation coefficient of the raw data was 0.46 ± 0.25. After automated, optimized piecewise alignment, the average correlation coefficient was 0.93 ± 0.02. Additionally, a relative shift metric and principal component analysis (PCA) were used to independently quantify and categorize the alignment performance, respectively. The relative shift metric was defined as four times the standard deviation of a given peak’s retention time in all of the chromatograms, divided by the peak-width-at-base. The raw simulated data sets that were studied contained peaks with average relative shifts ranging between 0.3 and 3.0. Second, a “real” data set of gasoline separations was gathered using three different GC methods to induce severe retention time shifting. In these gasoline separations, retention time precision improved ~8 fold following alignment. Finally, piecewise alignment and the unsupervised correlation optimization method were applied to severely shifted GC separations of reformate distillation fractions. The effect of piecewise alignment on peak heights and peak areas is also reported. Piecewise alignment either did not change the peak height, or caused it to slightly decrease. The average relative difference in peak height after piecewise alignment was –0.20%. Piecewise alignment caused the peak areas to either stay the same, slightly increase, or slightly decrease. The average absolute relative difference in area after piecewise alignment was 0.15%.« less

Stability of hypersonic boundary-layer flows with chemistry

NASA Technical Reports Server (NTRS)

Reed, Helen L.; Stuckert, Gregory K.; Haynes, Timothy S.

1993-01-01

The effects of nonequilibrium chemistry and three dimensionality on the stability characteristics of hypersonic flows are discussed. In two-dimensional (2-D) and axisymmetric flows, the inclusion of chemistry causes a shift of the second mode of Mack to lower frequencies. This is found to be due to the increase in size of the region of relative supersonic flow because of the lower speeds of sound in the relatively cooler boundary layers. Although this shift in frequency is present in both the equilibrium and nonequilibrium air results, the equilibrium approximation predicts modes which are not observed in the nonequilibrium calculations (for the flight conditions considered). These modes are superpositions of incoming and outgoing unstable disturbances which travel supersonically relative to the boundary-layer edge velocity. Such solutions are possible because of the finite shock stand-off distance. Their corresponding wall-normal profiles exhibit an oscillatory behavior in the inviscid region between the boundary-layer edge and the bow shock. For the examination of three-dimensional (3-D) effects, a rotating cone is used as a model of a swept wing. An increase of stagnation temperature is found to be only slightly stabilizing. The correlation of transition location (N = 9) with parameters describing the crossflow profile is discussed. Transition location does not correlate with the traditional crossflow Reynolds number. A new parameter that appears to correlate for boundary-layer flow was found. A verification with experiments on a yawed cone is provided.

High-precision Predictions for the Acoustic Scale in the Nonlinear Regime

NASA Astrophysics Data System (ADS)

Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Mehta, Kushal; Metchnik, Marc; Padmanabhan, Nikhil; Pinto, Phillip; Takahashi, Ryuichi; White, Martin; Xu, Xiaoying

2010-09-01

We measure shifts of the acoustic scale due to nonlinear growth and redshift distortions to a high precision using a very large volume of high-force-resolution simulations. We compare results from various sets of simulations that differ in their force, volume, and mass resolution. We find a consistency within 1.5σ for shift values from different simulations and derive shift α(z) - 1 = (0.300 ± 0.015) %[D(z)/D(0)]2 using our fiducial set. We find a strong correlation with a non-unity slope between shifts in real space and in redshift space and a weak correlation between the initial redshift and low redshift. Density-field reconstruction not only removes the mean shifts and reduces errors on the mean, but also tightens the correlations. After reconstruction, we recover a slope of near unity for the correlation between the real and redshift space and restore a strong correlation between the initial and the low redshifts. We derive propagators and mode-coupling terms from our N-body simulations and compare with the Zel'dovich approximation and the shifts measured from the χ2 fitting, respectively. We interpret the propagator and the mode-coupling term of a nonlinear density field in the context of an average and a dispersion of its complex Fourier coefficients relative to those of the linear density field; from these two terms, we derive a signal-to-noise ratio of the acoustic peak measurement. We attempt to improve our reconstruction method by implementing 2LPT and iterative operations, but we obtain little improvement. The Fisher matrix estimates of uncertainty in the acoustic scale is tested using 5000 h -3 Gpc3 of cosmological Particle-Mesh simulations from Takahashi et al. At an expected sample variance level of 1%, the agreement between the Fisher matrix estimates based on Seo and Eisenstein and the N-body results is better than 10%.

Toward calculations of the 129Xe chemical shift in Xe@C60 at experimental conditions: relativity, correlation, and dynamics.

PubMed

Straka, Michal; Lantto, Perttu; Vaara, Juha

2008-03-27

We calculate the 129Xe chemical shift in endohedral Xe@C60 with systematic inclusion of the contributing physical effects to model the real experimental conditions. These are relativistic effects, electron correlation, the temperature-dependent dynamics, and solvent effects. The ultimate task is to obtain the right result for the right reason and to develop a physically justified methodological model for calculations and simulations of endohedral Xe fullerenes and other confined Xe systems. We use the smaller Xe...C6H6 model to calibrate density functional theory approaches against accurate correlated wave function methods. Relativistic effects as well as the coupling of relativity and electron correlation are evaluated using the leading-order Breit-Pauli perturbation theory. The dynamic effects are treated in two ways. In the first approximation, quantum dynamics of the Xe atom in a rigid cage takes advantage of the centrosymmetric potential for Xe within the thermally accessible distance range from the center of the cage. This reduces the problem of obtaining the solution of a diatomic rovibrational problem. In the second approach, first-principles classical molecular dynamics on the density functional potential energy hypersurface is used to produce the dynamical trajectory for the whole system, including the dynamic cage. Snapshots from the trajectory are used for calculations of the dynamic contribution to the absorption 129Xe chemical shift. The calculated nonrelativistic Xe shift is found to be highly sensitive to the optimized molecular structure and to the choice of the exchange-correlation functional. Relativistic and dynamic effects are significant and represent each about 10% of the nonrelativistic static shift at the minimum structure. While the role of the Xe dynamics inside of the rigid cage is negligible, the cage dynamics turns out to be responsible for most of the dynamical correction to the 129Xe shift. Solvent effects evaluated with a polarized continuum model are found to be very small.

Origin of the monolayer Raman signature in hexagonal boron nitride: a first-principles analysis.

PubMed

Ontaneda, Jorge; Singh, Anjali; Waghmare, Umesh V; Grau-Crespo, Ricardo

2018-05-10

Monolayers of hexagonal boron nitride (h-BN) can in principle be identified by a Raman signature, consisting of an upshift in the frequency of the E 2g vibrational mode with respect to the bulk value, but the origin of this shift (intrinsic or support-induced) is still debated. Herein we use density functional theory calculations to investigate whether there is an intrinsic Raman shift in the h-BN monolayer in comparison with the bulk. There is universal agreement among all tested functionals in predicting the magnitude of the frequency shift upon a variation in the in-plane cell parameter. It is clear that a small in-plane contraction can explain the Raman peak upshift from bulk to monolayer. However, we show that the larger in-plane parameter in the bulk (compared to the monolayer) results from non-local correlation effects, which cannot be accounted for by local functionals or those with empirical dispersion corrections. Using a non-local-correlation functional, we then investigate the effect of finite temperatures on the Raman signature. We demonstrate that bulk h-BN thermally expands in the direction perpendicular to the layers, while the intralayer distances slightly contract, in agreement with observed experimental behavior. Interestingly, the difference in in-plane cell parameter between bulk and monolayer decreases with temperature, and becomes very small at room temperature. We conclude that the different thermal expansion of bulk and monolayer partially 'erases' the intrinsic Raman signature, accounting for its small magnitude in recent experiments on suspended samples.

Origin of the monolayer Raman signature in hexagonal boron nitride: a first-principles analysis

NASA Astrophysics Data System (ADS)

Ontaneda, Jorge; Singh, Anjali; Waghmare, Umesh V.; Grau-Crespo, Ricardo

2018-05-01

Monolayers of hexagonal boron nitride (h-BN) can in principle be identified by a Raman signature, consisting of an upshift in the frequency of the E2g vibrational mode with respect to the bulk value, but the origin of this shift (intrinsic or support-induced) is still debated. Herein we use density functional theory calculations to investigate whether there is an intrinsic Raman shift in the h-BN monolayer in comparison with the bulk. There is universal agreement among all tested functionals in predicting the magnitude of the frequency shift upon a variation in the in-plane cell parameter. It is clear that a small in-plane contraction can explain the Raman peak upshift from bulk to monolayer. However, we show that the larger in-plane parameter in the bulk (compared to the monolayer) results from non-local correlation effects, which cannot be accounted for by local functionals or those with empirical dispersion corrections. Using a non-local-correlation functional, we then investigate the effect of finite temperatures on the Raman signature. We demonstrate that bulk h-BN thermally expands in the direction perpendicular to the layers, while the intralayer distances slightly contract, in agreement with observed experimental behavior. Interestingly, the difference in in-plane cell parameter between bulk and monolayer decreases with temperature, and becomes very small at room temperature. We conclude that the different thermal expansion of bulk and monolayer partially ‘erases’ the intrinsic Raman signature, accounting for its small magnitude in recent experiments on suspended samples.

Immersion in altered experience: An investigation of the relationship between absorption and psychopathology

PubMed Central

Rosen, Cherise; Jones, Nev; Chase, Kayla A.; Melbourne, Jennifer K.; Grossman, Linda S.; Sharma, Rajiv P.

2017-01-01

Understanding alterations in perceptual experiences as a component of the basic symptom structure of psychosis may improve early detection and the identification of subtle shifts that can precede symptom exacerbation. We explored the phenomenological construct of absorption and psychotic experiences in both clinical (bipolar psychosis and schizophrenia spectrum) and non-clinical participants. Participants with psychosis endorsed significantly higher absorption compared to the non-clinical group. Absorption was positively correlated with all types of hallucinations and multiple types of delusions. The analysis yielded two distinct cluster groups that demarcated a distinction along the continuum of self-disturbance: on characterized by attenuated ego boundaries and the other stable ego boundaries. The study suggests that absorption is a potentially important but under-researched component of psychosis that overlaps with, but is not identical to the more heavily theorized constructs of aberrant salience and hyperreflexivity. PMID:28219788

Self-assessed quality of sleep, occupational health, working environment, illness experience and job satisfaction of female nurses working different combination of shifts.

PubMed

Sveinsdóttir, Herdis

2006-06-01

The aim of this study was to describe and compare the self-assessed quality of sleep, occupational health, working environment, illness experience and job satisfaction among female nurses working different combinations of shifts. Evidence from several studies indicates that there is an association between the disruption of the circadian cycle caused by shift work and adverse health effects. A cross-sectional design was used with a sample of 348 nurses drawn from the registry of the Icelandic Nurses' Association, representing 17% of the workforce of Icelandic nurses. A self-administered questionnaire, measuring occupational health, quality of sleep, the illness experience, job satisfaction and working environment was used. Data were analysed according to type of shift (days only, rotating days/evenings, rotating days/evenings/nights) by use of analysis of variance and chi-square. No difference was found between participants based on type of shift with regard to the illness experience, job satisfaction and quality of sleep. Nurses working rotating day/evening/night shifts reported a longer working day, more stressful environmental risk factors, more strenuous work and that they were less able to control their work-pace. In general, the nurses reported low severity of symptoms; however, nurses working rotating days/evenings shifts experienced more severe gastrointestinal and musculoskeletal symptoms when compared with others. This was explained by the short rest period provided for between evening and morning shifts. In general Icelandic nurses are satisfied with their work and their shift assignment does not seem to pathologically disrupt their circadian cycle. Nevertheless, nursing directors are advised to look more closely at the organization of nurses' work during night shifts, as well as the rest period for nurses changing from evening to day shifts.

Effect of angular velocity on sensors based on morphology dependent resonances.

PubMed

Ali, Amir R; Ioppolo, Tindaro

2014-04-22

We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning sensor based on MDR may experience sufficient shift in the optical resonances, therefore interfering with its desirable operational sensor design. Also the results show that angular velocity sensors could be designed using this principle.

The distribution shifts of Pinus armandii and its response to temperature and precipitation in China

PubMed Central

Zheng, Xiaofeng; Gao, Pengxiang

2017-01-01

Background The changing climate, particularly in regard to temperature and precipitation, is already affecting tree species’ distributions. Pinus armandii, which dominates on the Yungui Plateau and in the Qinba Mountains in China, is of economic, cultural and ecological value. We wish to test the correlations between the distribution shift of P. armandii and changing climate, and figure out how it tracks future climate change. Methods We sampled the surface soil at sites throughout the distribution of P. armandii to compare the relative abundance of pollen to the current percent cover of plant species. This was used to determine possible changes in the distribution P. armandii. Given the hilly terrain, elevation was considered together with temperature and precipitation as variables correlated with distribution shifts of P. armandii. Results We show that P. armandii is undergoing change in its geographic range, including retraction, a shift to more northern areas and from the upper high part of the mountains to a lower-altitude part in hilly areas. Temperature was the strongest correlate of this distribution shift. Elevation and precipitation were also both significantly correlated with distribution change of P. armandii, but to a lesser degree than temperature. Conclusion The geographic range of P. armandii has been gradually decreasing under the influence of climate change. This provides evidence of the effect of climate change on trees at the species level and suggests that at least some species will have a limited ability to track the changing climate. PMID:28929025

The relationship between thermal comfort and light intensity with sleep quality and eye tiredness in shift work nurses.

PubMed

Azmoon, Hiva; Dehghan, Habibollah; Akbari, Jafar; Souri, Shiva

2013-01-01

Environmental conditions such as lighting and thermal comfort are influencing factors on sleep quality and visual tiredness. The purpose of this study was the determination of the relationship between thermal comfort and light intensity with the sleep quality and eye fatigue in shift nurses. This cross-sectional research was conducted on 82 shift-work personnel of 18 nursing workstations in Isfahan Al-Zahra Hospital, Iran, in 2012. Heat stress monitoring (WBGT) and photometer (Hagner Model) were used for measuring the thermal conditions and illumination intensity, respectively. To measure the sleep quality, visual tiredness, and thermal comfort, Pittsburg sleep quality index, eye fatigue questionnaire, and thermal comfort questionnaire were used, respectively. The data were analyzed with descriptive statistics, Student's t-test, and Pearson correlation. Correlation between thermal comfort which was perceived from the self-reporting of people with eye tiredness was -0.38 (P = 0.002). Pearson correlation between thermal comfort and sleep quality showed a positive and direct relationship (r = 0.241, P = 0.33) but the correlation between thermal comfort, which was perceived from the self-reporting of shift nurses, and WBGT index was a weak relationship (r = 0.019). Based on the obtained findings, it can be concluded that a defect in environmental conditions such as thermal conditions and light intensity and also lack of appropriate managerial plan for night shift-work nurses are destructive and negative factors for the physical and mental health of this group of practitioners.

Carbon X-ray absorption spectra of fluoroethenes and acetone: A study at the coupled cluster, density functional, and static-exchange levels of theory

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

Fransson, Thomas; Norman, Patrick; Coriani, Sonia

2013-03-28

Near carbon K-edge X-ray absorption fine structure spectra of a series of fluorine-substituted ethenes and acetone have been studied using coupled cluster and density functional theory (DFT) polarization propagator methods, as well as the static-exchange (STEX) approach. With the complex polarization propagator (CPP) implemented in coupled cluster theory, relaxation effects following the excitation of core electrons are accounted for in terms of electron correlation, enabling a systematic convergence of these effects with respect to electron excitations in the cluster operator. Coupled cluster results have been used as benchmarks for the assessment of propagator methods in DFT as well as themore » state-specific static-exchange approach. Calculations on ethene and 1,1-difluoroethene illustrate the possibility of using nonrelativistic coupled cluster singles and doubles (CCSD) with additional effects of electron correlation and relativity added as scalar shifts in energetics. It has been demonstrated that CPP spectra obtained with coupled cluster singles and approximate doubles (CC2), CCSD, and DFT (with a Coulomb attenuated exchange-correlation functional) yield excellent predictions of chemical shifts for vinylfluoride, 1,1-difluoroethene, trifluoroethene, as well as good spectral features for acetone in the case of CCSD and DFT. Following this, CPP-DFT is considered to be a viable option for the calculation of X-ray absorption spectra of larger {pi}-conjugated systems, and CC2 is deemed applicable for chemical shifts but not for studies of fine structure features. The CCSD method as well as the more approximate CC2 method are shown to yield spectral features relating to {pi}*-resonances in good agreement with experiment, not only for the aforementioned molecules but also for ethene, cis-1,2-difluoroethene, and tetrafluoroethene. The STEX approach is shown to underestimate {pi}*-peak separations due to spectral compressions, a characteristic which is inherent to this method.« less

Carbon X-ray absorption spectra of fluoroethenes and acetone: a study at the coupled cluster, density functional, and static-exchange levels of theory.

PubMed

Fransson, Thomas; Coriani, Sonia; Christiansen, Ove; Norman, Patrick

2013-03-28

Near carbon K-edge X-ray absorption fine structure spectra of a series of fluorine-substituted ethenes and acetone have been studied using coupled cluster and density functional theory (DFT) polarization propagator methods, as well as the static-exchange (STEX) approach. With the complex polarization propagator (CPP) implemented in coupled cluster theory, relaxation effects following the excitation of core electrons are accounted for in terms of electron correlation, enabling a systematic convergence of these effects with respect to electron excitations in the cluster operator. Coupled cluster results have been used as benchmarks for the assessment of propagator methods in DFT as well as the state-specific static-exchange approach. Calculations on ethene and 1,1-difluoroethene illustrate the possibility of using nonrelativistic coupled cluster singles and doubles (CCSD) with additional effects of electron correlation and relativity added as scalar shifts in energetics. It has been demonstrated that CPP spectra obtained with coupled cluster singles and approximate doubles (CC2), CCSD, and DFT (with a Coulomb attenuated exchange-correlation functional) yield excellent predictions of chemical shifts for vinylfluoride, 1,1-difluoroethene, trifluoroethene, as well as good spectral features for acetone in the case of CCSD and DFT. Following this, CPP-DFT is considered to be a viable option for the calculation of X-ray absorption spectra of larger π-conjugated systems, and CC2 is deemed applicable for chemical shifts but not for studies of fine structure features. The CCSD method as well as the more approximate CC2 method are shown to yield spectral features relating to π∗-resonances in good agreement with experiment, not only for the aforementioned molecules but also for ethene, cis-1,2-difluoroethene, and tetrafluoroethene. The STEX approach is shown to underestimate π∗-peak separations due to spectral compressions, a characteristic which is inherent to this method.

3D Double-Quantum/Double-Quantum Exchange Spectroscopy of Protons under 100 kHz Magic Angle Spinning.

PubMed

Zhang, Rongchun; Duong, Nghia Tuan; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

2017-06-22

Solid-state 1 H NMR spectroscopy has attracted much attention in the recent years due to the remarkable spectral resolution improvement by ultrafast magic-angle-spinning (MAS) as well as due to the sensitivity enhancement rendered by proton detection. Although these developments have enabled the investigation of a variety of challenging chemical and biological solids, the proton spectral resolution is still poor for many rigid solid systems owing to the presence of conformational heterogeneity and the unsuppressed residual proton-proton dipolar couplings even with the use of the highest currently feasible sample spinning speed of ∼130 kHz. Although a further increase in the spinning speed of the sample could be beneficial to some extent, there is a need for alternate approaches to enhance the spectral resolution. Herein, by fully utilizing the benefits of double-quantum (DQ) coherences, we propose a single radio frequency channel proton-based 3D pulse sequence that correlates double-quantum (DQ), DQ, and single-quantum (SQ) chemical shifts of protons. In addition to the two-spin homonuclear proximity information, the proposed 3D DQ/DQ/SQ experiment also enables the extraction of three-spin and four-spin proximities, which could be beneficial for revealing the dipolar coupled proton network in the solid state. Besides, the 2D DQ/DQ spectrum sliced at different isotropic SQ chemical shift values of the 3D DQ/DQ/SQ spectrum will also facilitate the identification of DQ correlation peaks and improve the spectral resolution, as it only provides the local homonuclear correlation information associated with the specific protons selected by the SQ chemical shift frequency. The 3D pulse sequence and its efficiency are demonstrated experimentally on small molecular compounds in the solid state. We expect that this approach would create avenues for further developments by suitably combining the benefits of partial deuteration of samples, selective excitation/decoupling pulses, heteronuclear spins for spectral editing, and nonuniform sampling.

Inter-decadal change of the lagged inter-annual relationship between local sea surface temperature and tropical cyclone activity over the western North Pacific

NASA Astrophysics Data System (ADS)

Zhao, Haikun; Wu, Liguang; Raga, G. B.

2018-02-01

This study documents the inter-decadal change of the lagged inter-annual relationship between the TC frequency (TCF) and the local sea surface temperature (SST) in the western North Pacific (WNP) during 1979-2014. An abrupt shift of the lagged relationship between them is observed to occur in 1998. Before the shift (1979-1997), a moderately positive correlation (0.35) between previous-year local SST and TCF is found, while a significantly negative correlation (- 0.71) is found since the shift (1998-2014). The inter-decadal change of the lagged relationship between TCF and local SST over the WNP is also accompanied by an inter-decadal change in the lagged inter-annual relationship between large-scale factors affecting TCs and local SST over the WNP. During 1998-2014, the previous-year local SST shows a significant negative correlation with the mid-level moisture and a significant positive correlation with the vertical wind shear over the main development region of WNP TC genesis. Almost opposite relationships are seen during 1979-1997, with a smaller magnitude of the correlation coefficients. These changes are consistent with the changes of the lagged inter-annual relationship between upper- and lower-level winds and local SST over the WNP. Analyses further suggests that the inter-decadal shift of the lagged inter-annual relationship between WNP TCF and local SST may be closely linked to the inter-decadal change of inter-annual SST transition over the tropical central-eastern Pacific associated with the climate regime shift in the late 1990s. Details on the underlying physical process need further investigation using observations and simulations.

Surface Information Loss in Comprehension

PubMed Central

Gernsbacher, Morton Ann

2014-01-01

Shortly after a sentence has been comprehended, information about its exact surface form (e.g., its word order) becomes less available. The present research demonstrated this phenomenon during the comprehension of nonverbal stimuli (picture stories). In Experiment 1, significantly more surface (left/right orientation) information was lost after comprehending several picture stories than just one; in Experiment 2, more was lost after comprehending an entire picture story than half of one. In Experiment 3, subjects segmented the picture stories into their constituents; in Experiment 4, significantly more surface information was lost after crossing these constituents’ boundaries than before. The present research also investigated why surface information is lost. Four explanations were considered: Surface information loss is the result of performing grammatical transformations (the linguistic hypothesis), exceeding short-term memory limitations (the memory limitations hypothesis), integrating information into gist (the integration hypothesis), shifting from building one substructure to initiating another (the processing shift hypothesis). The linguistic and memory limitations hypotheses were considered inadequate; the integration and the processing shift hypotheses were tested in the last set of experiments. In Experiment 5 (using nonverbal stimuli), the predictions made by the processing shift hypothesis were confirmed; in Experiment 6 (using verbal stimuli), these results were replicated. Other implications of the processing shift hypothesis concerning surface information loss are discussed. PMID:25308975

13C-13C dipolar recoupling under very fast magic angle spinning in solid-state nuclear magnetic resonance: Applications to distance measurements, spectral assignments, and high-throughput secondary-structure determination

NASA Astrophysics Data System (ADS)

Ishii, Yoshitaka

2001-05-01

A technique is presented to recouple homonuclear dipolar couplings between dilute spin pairs such as 13C-13C systems under very fast magic angle spinning (MAS) in solid-state nuclear magnetic resonance (NMR) spectroscopy. The presented technique, finite pulse rf driven recoupling (fpRFDR), restores homonuclear dipolar interactions based on constructive usage of finite pulse-width effects in a phase- and symmetry-cycled π-pulse train in which a rotor-synchronous π pulse is applied every rotation period. The restored effective dipolar interaction has the form of a zero-quantum dipolar Hamiltonian for static solids, whose symmetry in spin space is different from that obtained by conventional rf driven recoupling (RFDR) techniques. It is demonstrated that the efficiency of recoupling by fpRFDR is not strongly dependent on chemical shift differences or resonance offsets in contrast to previous recoupling methods under very fast MAS. To realize distance measurements without effects of spin relaxation, a constant-time version of fpRFDR (CT-fpRFDR) is introduced, in which the effective evolution period is varied by refocusing dipolar evolution with a rotor-synchronized solid echo while the total recoupling period is kept constant. From CT-fpRFDR experiments at a spinning speed of 30.3 kHz in a field of 17.6 T, the 13C-13C distance of [1-13C]Ala-[1-13C]Gly-Gly was determined to be 3.27 Å, which agrees well with the value of 3.20 Å obtained by x-ray diffraction. Also, two-dimensional (2D) 13C/13C chemical-shift correlation NMR spectrum in a field of 9.4 T was obtained with fpRFDR for fibrils of the segmentally 13C- and 15N-labeled Alzheimer's β-Amyloid fragments, Aβ16-22 (residues 16-22 taken from the 40-residue Aβ peptide) in which Leu-17 through Ala-21 are uniformly 13C- and 15N-labeled. Most 13C resonances for the main chain as well as for the side chains are assigned based on 2D 13C/13C chemical-shift correlation patterns specific to amino-acid types. Examination of the obtained 13C chemical shifts revealed the formation of β-strand across the entire molecule of Aβ16-22. Possibility of high throughput determination of global main-chain structures based on 13C shifts obtained from 2D 13C/13C chemical-shift correlation under very fast MAS is also discussed for uniformly/segmentally 13C-labeled protein/peptide samples.

Digital Speckle Photography of Subpixel Displacements of Speckle Structures Based on Analysis of Their Spatial Spectra

NASA Astrophysics Data System (ADS)

Maksimova, L. A.; Ryabukho, P. V.; Mysina, N. Yu.; Lyakin, D. V.; Ryabukho, V. P.

2018-04-01

We have investigated the capabilities of the method of digital speckle interferometry for determining subpixel displacements of a speckle structure formed by a displaceable or deformable object with a scattering surface. An analysis of spatial spectra of speckle structures makes it possible to perform measurements with a subpixel accuracy and to extend the lower boundary of the range of measurements of displacements of speckle structures to the range of subpixel values. The method is realized on the basis of digital recording of the images of undisplaced and displaced speckle structures, their spatial frequency analysis using numerically specified constant phase shifts, and correlation analysis of spatial spectra of speckle structures. Transformation into the frequency range makes it possible to obtain quantities to be measured with a subpixel accuracy from the shift of the interference-pattern minimum in the diffraction halo by introducing an additional phase shift into the complex spatial spectrum of the speckle structure or from the slope of the linear plot of the function of accumulated phase difference in the field of the complex spatial spectrum of the displaced speckle structure. The capabilities of the method have been investigated in natural experiment.

On the relation between pitch and level.

PubMed

Zheng, Yi; Brette, Romain

2017-05-01

Pitch is the perceptual dimension along which musical notes are ordered from low to high. It is often described as the perceptual correlate of the periodicity of the sound's waveform. Previous reports have shown that pitch can depend slightly on sound level. We wanted to verify that these observations reflect genuine changes in perceived pitch, and were not due to procedural factors or confusion between dimensions of pitch and level. We first conducted a systematic pitch matching task and confirmed that the pitch of low frequency pure tones, but not complex tones, decreases by an amount equivalent to a change in frequency of more than half a semitone when level increases. We then showed that the structure of pitch shifts is anti-symmetric and transitive, as expected for changes in pitch. We also observed shifts in the same direction (although smaller) in an interval matching task. Finally, we observed that musicians are more precise in pitch matching tasks than non-musicians but show the same average shifts with level. These combined experiments confirm that the pitch of low frequency pure tones depends weakly but systematically on level. These observations pose a challenge to current theories of pitch. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantum Electrodynamical Shifts in Multivalent Heavy Ions.

PubMed

Tupitsyn, I I; Kozlov, M G; Safronova, M S; Shabaev, V M; Dzuba, V A

2016-12-16

The quantum electrodynamics (QED) corrections are directly incorporated into the most accurate treatment of the correlation corrections for ions with complex electronic structure of interest to metrology and tests of fundamental physics. We compared the performance of four different QED potentials for various systems to access the accuracy of QED calculations and to make a prediction of highly charged ion properties urgently needed for planning future experiments. We find that all four potentials give consistent and reliable results for ions of interest. For the strongly bound electrons, the nonlocal potentials are more accurate than the local potential.

Near-infrared absorption in symmetric squarylium and croconate dyes: a comparative study using symmetry-adapted cluster-configuration interaction methods.

PubMed

Prabhakar, Ch; Yesudas, K; Krishna Chaitanya, G; Sitha, Sanyasi; Bhanuprakash, K; Rao, V Jayathirtha

2005-09-29

Symmetric croconate (CR) and squarylium dyes (SQ) are well-known near-infrared (NIR) dyes and, in general, are considered to be donor-acceptor-donor type molecules. It is established in the literature that CR dyes absorb in a longer wavelength region than the corresponding SQ dyes. This has been attributed to the CR ring being a better acceptor than the SQ ring. Thus increasing the donor capacity should lead to a bathochromic shift in both SQ and CR. On the other hand, some experiments reported in the literature have revealed that increasing the conjugation in the donor part of the SQ molecule leads first to red shift, which upon a further increase of the conjugation changes to a blue shift. Hence, to understand the role of the central ring and the substitutions in the absorption of these dyes, we carried out high-level symmetry-adapted cluster-configuration interaction (SAC-CI) calculations of some substituted SQ and CR dyes and compare the absorption energy with the existing experimental data. We found that there is very good agreement. We also carried out SAC-CI calculations of some smaller model molecules, which contain the main oxyallyl substructure. We varied the geometry (angle) of the oxyallyl subgroup and the substitution in these model molecules to establish a correlation with the bathochromic shift. We found that the charge transfer is very small and does not play the key role in the red shift, but on the other hand, the perturbation of the HOMO-LUMO gap (HLG) from both the geometry and substitution seems to be responsible for this shift. We suggest as a design principle that increasing the donor capacity of the groups may not help in the red shift, but introducing groups which perturb the HLG and decrease it without changing the MO character should lead to a larger bathochromic shift.

Small-scale experimental study of vaporization flux of liquid nitrogen released on water.

PubMed

Gopalaswami, Nirupama; Olewski, Tomasz; Véchot, Luc N; Mannan, M Sam

2015-10-30

A small-scale experimental study was conducted using liquid nitrogen to investigate the convective heat transfer behavior of cryogenic liquids released on water. The experiment was performed by spilling five different amounts of liquid nitrogen at different release rates and initial water temperatures. The vaporization mass fluxes of liquid nitrogen were determined directly from the mass loss measured during the experiment. A variation of initial vaporization fluxes and a subsequent shift in heat transfer mechanism were observed with changes in initial water temperature. The initial vaporization fluxes were directly dependent on the liquid nitrogen spill rate. The heat flux from water to liquid nitrogen determined from experimental data was validated with two theoretical correlations for convective boiling. It was also observed from validation with correlations that liquid nitrogen was found to be predominantly in the film boiling regime. The substantial results provide a suitable procedure for predicting the heat flux from water to cryogenic liquids that is required for source term modeling. Copyright © 2015 Elsevier B.V. All rights reserved.

Physiological and neural correlates of worry and rumination: Support for the contrast avoidance model of worry.

PubMed

Steinfurth, Elisa C K; Alius, Manuela G; Wendt, Julia; Hamm, Alfons O

2017-02-01

The current experiments tested neural and physiological correlates of worry and rumination in comparison to thinking about neutral events. According to the avoidance model-stating that worry is a strategy to reduce intense emotions-physiological and neurobiological activity during worried thinking should not differ from activation during neutral thinking. According to the contrast avoidance model-stating that worry is a strategy to reduce abrupt shifts of emotions-activity should be increased. To test these competing models, we induced worry and neutral thinking in healthy participants using personal topics. A rumination condition was added to investigate the specificity of changes induced by the mental process. Two experiments were conducted assessing the effects on different response levels: (1) neural activation using fMRI, and (2) physiological response mobilization using startle and autonomic measures. During worry, participants showed a potentiated startle response and BOLD activity indicative of emotional network activation. These data partly support the contrast avoidance model of worry. Both mental processes showed elevated activity in a common network referred to as default network indicating self-referential activity. © 2016 Society for Psychophysiological Research.

The Modality Shift Experiment in Adults and Children with High Functioning Autism

ERIC Educational Resources Information Center

Williams, Diane L.; Goldstein, Gerald; Minshew, Nancy J.

2013-01-01

This study used the modality shift experiment, a relatively simple reaction time measure to visual and auditory stimuli, to examine attentional shifting within and across modalities in 33 children and 42 adults with high-functioning autism as compared to matched numbers of age- and ability-matched typical controls. An exaggerated "modality shift…

The Effect of Modality Shifts on Practive Interference in Long-Term Memory.

ERIC Educational Resources Information Center

Dean, Raymond S.; And Others

1983-01-01

In experiment one, subjects learned a word list in blocked or random forms of auditory/visual change. In experiment two, high- and low-conceptual rigid subjects read passages in shift conditions or nonshift, exclusively in auditory or visual modes. A shift in modality provided a powerful release from proactive interference. (Author/CM)

Double resonance calibration of g factor standards: Carbon fibers as a high precision standard.

PubMed

Herb, Konstantin; Tschaggelar, Rene; Denninger, Gert; Jeschke, Gunnar

2018-04-01

The g factor of paramagnetic defects in commercial high performance carbon fibers was determined by a double resonance experiment based on the Overhauser shift due to hyperfine coupled protons. Our carbon fibers exhibit a single, narrow and perfectly Lorentzian shaped ESR line and a g factor slightly higher than g free with g=2.002644=g free ·(1+162ppm) with a relative uncertainty of 15ppm. This precisely known g factor and their inertness qualify them as a high precision g factor standard for general purposes. The double resonance experiment for calibration is applicable to other potential standards with a hyperfine interaction averaged by a process with very short correlation time. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The target-to-foils shift in simultaneous and sequential lineups.

PubMed

Clark, Steven E; Davey, Sherrie L

2005-04-01

A theoretical cornerstone in eyewitness identification research is the proposition that witnesses, in making decisions from standard simultaneous lineups, make relative judgments. The present research considers two sources of support for this proposal. An experiment by G. L. Wells (1993) showed that if the target is removed from a lineup, witnesses shift their responses to pick foils, rather than rejecting the lineups, a result we will term a target-to-foils shift. Additional empirical support is provided by results from sequential lineups which typically show higher accuracy than simultaneous lineups, presumably because of a decrease in the use of relative judgments in making identification decisions. The combination of these two lines of research suggests that the target-to-foils shift should be reduced in sequential lineups relative to simultaneous lineups. Results of two experiments showed an overall advantage for sequential lineups, but also showed a target-to-foils shift equal in size for simultaneous and sequential lineups. Additional analyses indicated that the target-to-foils shift in sequential lineups was moderated in part by an order effect and was produced with (Experiment 2) or without (Experiment 1) a shift in decision criterion. This complex pattern of results suggests that more work is needed to understand the processes which underlie decisions in simultaneous and sequential lineups.

Ab initio calculation of the electronic absorption spectrum of liquid water

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

Martiniano, Hugo F. M. C.; Galamba, Nuno; Cabral, Benedito J. Costa, E-mail: ben@cii.fc.ul.pt

2014-04-28

The electronic absorption spectrum of liquid water was investigated by coupling a one-body energy decomposition scheme to configurations generated by classical and Born-Oppenheimer Molecular Dynamics (BOMD). A Frenkel exciton Hamiltonian formalism was adopted and the excitation energies in the liquid phase were calculated with the equation of motion coupled cluster with single and double excitations method. Molecular dynamics configurations were generated by different approaches. Classical MD were carried out with the TIP4P-Ew and AMOEBA force fields. The BLYP and BLYP-D3 exchange-correlation functionals were used in BOMD. Theoretical and experimental results for the electronic absorption spectrum of liquid water are inmore » good agreement. Emphasis is placed on the relationship between the structure of liquid water predicted by the different models and the electronic absorption spectrum. The theoretical gas to liquid phase blue-shift of the peak positions of the electronic absorption spectrum is in good agreement with experiment. The overall shift is determined by a competition between the O–H stretching of the water monomer in liquid water that leads to a red-shift and polarization effects that induce a blue-shift. The results illustrate the importance of coupling many-body energy decomposition schemes to molecular dynamics configurations to carry out ab initio calculations of the electronic properties in liquid phase.« less

High speed thin plate fatigue crack monitor

NASA Technical Reports Server (NTRS)

Wincheski, Buzz A. (Inventor); Heyman, Joseph S. (Inventor); Namkung, Min (Inventor); Fulton, James P. (Inventor)

1996-01-01

A device and method are provided which non-destructively detect crack length and crack geometry in thin metallic plates. A non-contacting vibration apparatus produces resonant vibrations without introducing extraneous noise. Resulting resonant vibration shifts in cracked plates are correlated to known crack length in plates with similar resonant vibration shifts. In addition, acoustic emissions of cracks at resonance frequencies are correlated to acoustic emissions from known crack geometries.

Interactions among plants, bacteria, and fungi reduce extracellular enzyme activities under long-term N fertilization.

PubMed

Carrara, Joseph E; Walter, Christopher A; Hawkins, Jennifer S; Peterjohn, William T; Averill, Colin; Brzostek, Edward R

2018-06-01

Atmospheric nitrogen (N) deposition has enhanced soil carbon (C) stocks in temperate forests. Most research has posited that these soil C gains are driven primarily by shifts in fungal community composition with elevated N leading to declines in lignin degrading Basidiomycetes. Recent research, however, suggests that plants and soil microbes are dynamically intertwined, whereby plants send C subsidies to rhizosphere microbes to enhance enzyme production and the mobilization of N. Thus, under elevated N, trees may reduce belowground C allocation leading to cascading impacts on the ability of microbes to degrade soil organic matter through a shift in microbial species and/or a change in plant-microbe interactions. The objective of this study was to determine the extent to which couplings among plant, fungal, and bacterial responses to N fertilization alter the activity of enzymes that are the primary agents of soil decomposition. We measured fungal and bacterial community composition, root-microbial interactions, and extracellular enzyme activity in the rhizosphere, bulk, and organic horizon of soils sampled from a long-term (>25 years), whole-watershed, N fertilization experiment at the Fernow Experimental Forest in West Virginia, USA. We observed significant declines in plant C investment to fine root biomass (24.7%), root morphology, and arbuscular mycorrhizal (AM) colonization (55.9%). Moreover, we found that declines in extracellular enzyme activity were significantly correlated with a shift in bacterial community composition, but not fungal community composition. This bacterial community shift was also correlated with reduced AM fungal colonization indicating that declines in plant investment belowground drive the response of bacterial community structure and function to N fertilization. Collectively, we find that enzyme activity responses to N fertilization are not solely driven by fungi, but instead reflect a whole ecosystem response, whereby declines in the strength of belowground C investment to gain N cascade through the soil environment. © 2018 John Wiley & Sons Ltd.

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

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

Blasberger, Avi; Behar, Ehud; Perets, Hagai B.

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorptionmore » and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.« less

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

NASA Astrophysics Data System (ADS)

Blasberger, Avi; Behar, Ehud; Perets, Hagai B.; Brosch, Noah; Tielens, Alexander G. G. M.

2017-02-01

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μm IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μm IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ˜15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ˜15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

Application of ChemDraw NMR Tool: Correlation of Program-Generated 13C Chemical Shifts and pKa Values of para-Substituted Benzoic Acids

NASA Astrophysics Data System (ADS)

Wang, Hongyi

2005-09-01

An application of ChemDraw NMR Tool was demonstrated by correlation of program-generated 13 C NMR chemical shifts and p K a values of para-substituted benzoic acids. Experimental 13 C NMR chemical shifts were analyzed in the same way for comparison. The project can be used as an assignment at the end of the first-year organic chemistry course to review topics or explore new techniques: Hammett equation, acid base equilibrium theory, electronic nature of functional groups, inductive and resonance effects, structure reactivity relationship, NMR spectroscopy, literature search, database search, and ChemDraw software.

Latitudinal shifts of introduced species: possible causes and implications

Treesearch

Qinfeng Guo; Dov F. Sax; Hong Qian; Regan Early

2012-01-01

This study aims to document shifts in the latitudinal distributions of non-native species relative to their own native distributions and to discuss possible causes and implications of these shifts. We used published and newly compiled data on intercontinentally introduced birds, mammals and plants. We found strong correlations between the latitudinal distributions...

Experimental Investigation of Flow Condensation in Microgravity

NASA Technical Reports Server (NTRS)

Lee, Hyoungsoon; Park, Ilchung; Konishi, Christopher; Mudawar, Issam; May, Rochelle I.; Juergens, Jeffery R.; Wagner, James D.; Hall, Nancy R.; Nahra, Henry K.; Hasan, Mohammed M.;

Factors Influencing Patient Experience in Pediatric Neurology.

PubMed

Singh, Suprit C; Sheth, Raj D; Burrows, James F; Rosen, Paul

2016-07-01

Hospitals have begun to shift toward patient-centered care because of the pay-for-performance system that was established by the Patient Protection and Affordable Care Act. In pediatrics, the needs of both the caregiver and the pediatric patient have to be taken into account. Pediatric practices have been shifting toward a family-centered approach, although the primary drivers have not been well defined. Identifying the key patient experiences that lead to higher patient satisfaction would enable a more meaningful clinical encounter. To better understand patient experience, we examined waiting time and the elements of the physician-patient interaction in pediatric neurology. We predict that the determining factor in patient satisfaction is the physician-patient interaction. Patient satisfaction surveys were sent to families via mail or e-mail after their ambulatory pediatric neurology visit. The visits took place between January 1, 2012, and December 31, 2014, at one of multiple locations in a children's health system spanning four states. A Likert scale was used for these surveys, and a top-box method (measuring percent of survey questions were rated 5 out of 5) was used to filter data from this database. Statistical analysis using a Pearson correlation was used for data analysis, with likelihood to recommend practice as the dependent variable. The five survey questions that correlated most with overall likelihood to recommend the practice were cheerfulness of practice (r = 0.79); staff working together (r = 0.76); cleanliness of practice (r = 0.70); wait time at clinic, from entering to leaving (r = 0.66); and likelihood of recommending care provider (r = 0.65). Pediatric neurologists striving to enhance overall patient satisfaction in their practices should work toward providing an atmosphere that supports office staff cheerfulness, teamwork, and visit efficiency provided in a clean and friendly environment. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluating the traditional day and night shift in an acute care surgery fellowship: Is the swing shift a better choice?

PubMed

Chestovich, Paul J; McNicoll, Christopher F; Ingalls, Nichole K; Kuhls, Deborah A; Fraser, Douglas R; Morrissey, Shawna L; Fildes, John J

2018-01-01

Fellowship trainees in acute care surgery require experience in the management of complex and operative trauma cases. Trauma center staffing usually follows standard 12-hour or 24-hour shifts, with resident and fellow trainees following a similar schedule. Although trauma admissions can be generally unpredictable, we analyzed temporal trends of trauma patient arrival times to determine the best time frame to maximize trainee experience during each day. We reviewed 10 years (2007-2016) of trauma registry data for blunt and penetrating trauma activations. Hourly volumetric trends were observed, and three specific events were chosen for detailed analysis: (1) trauma activation with Injury Severity Score (ISS) greater than 15, (2) laparotomy for trauma, and (3) thoracotomy for trauma. A retrospective shift log was created, which included day (7:00 AM to 7:00 PM), night (7:00 PM to 7:00 AM), and swing (noon to midnight) shifts. A swing shift was chosen because it captures the peak volume for all three events. Means and 95% confidence intervals were calculated, and comparisons were made between shifts using the Wilcoxon matched-pairs signed rank test with Bonferroni correction, and p less than 0.05 considered significant. During the 10-year study period, 28,287 patients were treated at our trauma center. This included the evaluation and management of 7,874 patients with ISS greater than 15, performance of 1,766 laparotomies, and 392 thoracotomies for trauma. Swing shift was superior to both day and night shifts for ISS greater than 15 (p < 0.001). Both swing and night shifts were superior to day shift for laparotomies (p < 0.001). Swing shift was superior to both day shift (p < 0.001) and night shift (p = 0.031). Shifts with the highest yield of ISS greater than 15, laparotomies, and thoracotomies include night and swing shifts on Fridays and Saturdays. Projected experience of acute care surgery fellows in managing complex trauma patients increases with the integration of swing shifts into the schedule. Daily trauma volume follows a temporal pattern which, when used correctly, can increase trainee exposure to complex and operative trauma cases. We encourage other centers to analyze their volume and adjust trainee schedules accordingly to maximize their educational experience. Therapeutic study, level IV.

Oxidative stress and insulin resistance in policemen working shifts.

PubMed

Demir, Irfan; Toker, Aysun; Zengin, Selcuk; Laloglu, Esra; Aksoy, Hulya

2016-04-01

Shift work is a work schedule involving irregular or unusual hours, compared to those of a normal daytime work schedule. In developed countries, night shift work is very common. In several cities of our country, 12/24 shift system is implemented in police organization. While night shift work composes half of the 20 shift in a month, in ergonomic shift system, an alternative shift schedule, shift work can be performed in three shifts in a day. In this study, we aimed to investigate the effects of 12/24 shift work system on insulin resistance and oxidative stress and systemic inflammation. Two hundred and four 12/24 shift workers (age 44.3 ± 5.6 years) and 193 ergonomic shift workers (age 42.6 ± 5.5 years) were included to study. Serum oxidized LDL (ox-LDL), neutrophil gelatinase lipocalin-2 (NGAL) as oxidative stress markers, glucose, insulin, ferritin, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate values were measured. Homeostasis model assessment for insulin resistance (HOMA-IR) was calculated to evaluate insulin resistance. Serum ox-LDL, HOMA-IR, hsCRP and NGAL levels in 12/24 shift system were found to be significantly higher compared with ergonomic shift workers (p < 0.0001, p = 0.02, p = 0.03, p = 0.02, respectively). When evaluated all subjects, weak but significant correlation was found between HOMA-IR with ox-LDL (r = 0.12, p = 0.01), hsCRP (r = 0.17, p = 0.001) and ferritin (r = 0.15, r = 0.003). Also in 12/24 shift work group, there were significant correlations between HOMA-IR with hsCRP (r = 0.17, p = 0.01) and ferritin (r = 0.25, p = 0.0001). It may be concluded that 12/24 shift system might give rise to insulin resistance and oxidative stress. Additionally, workers in this system may under risk of systemic inflammatory response. Working hours must be arranged in accordance with the physiological rhythm.

Time-delay-induced dynamical behaviors for an ecological vegetation growth system driven by cross-correlated multiplicative and additive noises.

PubMed

Wang, Kang-Kang; Ye, Hui; Wang, Ya-Jun; Li, Sheng-Hong

2018-05-14

In this paper, the modified potential function, the stationary probability distribution function (SPDF), the mean growth time and the mean degeneration time for a vegetation growth system with time delay are investigated, where the vegetation system is assumed to be disturbed by cross-correlated multiplicative and additive noises. The results reveal some fact that the multiplicative and additive noises can both reduce the stability and speed up the decline of the vegetation system, while the strength of the noise correlation and time delay can both enhance the stability of the vegetation and slow down the depression process of the ecological system. On the other hand, with regard to the impacts of noises and time delay on the mean development and degeneration processes of the ecological system, it is discovered that 1) in the development process of the vegetation population, the increase of the noise correlation strength and time delay will restrain the regime shift from the barren state to the boom one, while the increase of the additive noise can lead to the fast regime shift from the barren state to the boom one. 2) Conversely, in the depression process of the ecological system, the increase of the strength of the correlation noise and time delay will prevent the regime shift from the boom state to the barren one. Comparatively, the increase of the additive and multiplicative noises can accelerate the regime shift from the boom state to the barren state.

The correlation between movement of the center of mass and the kinematics of the spine, pelvis, and hip joints during body rotation.

PubMed

Wada, Osamu; Tateuchi, Hiroshige; Ichihashi, Noriaki

2014-01-01

Body rotation is associated with many activities. The concomitant movement of the center of mass (COM) is essential for effective body rotation. This movement is considered to be influenced by kinematic changes in the spine, pelvis, and hip joints. However, there is no research on the association between COM movement and kinematic changes during body rotation. We aimed to investigate the association between COM movement and the kinematics of the spine, pelvis, and hip joints during body rotation in standing. Twenty-four healthy men were included in the study. COM movement during active body rotation in a standing position was measured. We evaluated pelvic shift and changes in the angles of the spine, pelvis, and hip joints. We calculated the Pearson correlation coefficients to analyze the relationship between COM movement and kinematic changes in the spine, pelvis, and hip joints. There were significant correlations between lateral COM movement to the rotational side and pelvic shift to the rotational side, and between posterior COM movement and pelvic shift to the posterior side. In addition, lateral COM movement to the rotational side showed significant and negative correlation with spinal flexion and was significantly and positively correlated with the change in anterior pelvic tilt. Clinicians need to take particular note of both spinal and pelvic motion in the sagittal plane, as well as the pelvic shift, to speculate COM movement during body rotation in standing. Copyright © 2013 Elsevier B.V. All rights reserved.

Exposure to hexavalent chromium in welders: Results of the WELDOX II field study.

PubMed

Pesch, Beate; Lehnert, Martin; Weiss, Tobias; Kendzia, Benjamin; Menne, Eleonore; Lotz, Anne; Heinze, Evelyn; Behrens, Thomas; Gabriel, Stefan; Schneider, Wolfgang; Brüning, Thomas

2018-03-12

Exposure to hexavalent chromium (Cr(VI)) has been primarily studied in chromate production. Here, we measured personal exposure to respirable Cr(VI) together with airborne and urinary Cr and Ni in welders to explore levels and associations between various measures of exposure. Shift concentrations of Cr(VI), Cr, and Ni were measured in respirable welding fumes in 50 men who used either gas metal arc welding (GMAW) (n = 24) or tungsten inert gas welding (TIG) (n = 19) as their major technique. Cr and Ni were determined in pre- and post-shift urine samples. Concentrations below the limit of quantification (LOQ) were multiply imputed. Spearman correlation coefficients (rs) were calculated with 95% confidence intervals (CIs) to explore associations between the exposure variables, and regression models were applied to estimate the effect of the parent metal on the urinary concentration. Regarding the respirable Cr(VI), 62% of the measurements were below the LOQ, the 75th percentile was 0.50 µg m-3, and 8 out of 50 (16%) welders exceeded 1 µg m-3. The highest shift concentration that occurred as a result of shielded metal arc welding (SMAW) was 180 µg m-3. The Cr(VI) content in total Cr ranged from 4 to 82% (median 20%), although the concentration correlated with total Cr (rs 0.55, 95% CI 0.46; 0.64). The correlation between Cr(VI) and Ni was weaker (rs 0.42, 95% CI 0.34; 0.51) than that between total Cr and Ni in welding fumes (rs 0.83, 95% CI 0.74; 0.92). Both Cr(VI) and total Cr influenced the urinary Cr concentrations in post-shift samples (P = 0.0008 and P ≤ 0.0001, respectively). The airborne shift exposure was a weaker determinant than the Cr content in pre-shift urine samples, which strongly correlated with post-shift urinary Cr (rs 0.78, 95% CI 0.69; 0.87). The Cr(VI) content in total Cr varied considerably in welding fumes. The majority of welders using GMAW or TIG presented with shift concentrations of respirable Cr(VI) below 1 µg m-3. However, very high Cr(VI) concentrations may occur, for example in SMAW. The urinary concentration of total Cr, cannot be used to precisely determine the shift concentration of respirable Cr(VI) in welders.

Adaptation to abrupt time shifts of the oscillator(s) controlling human circadian rhythms.

PubMed Central

Mills, J N; Minors, D S; Waterhouse, J M

1978-01-01

1. Thirty-six subjects in an isolation unit were subjected to time shifts of 12 hr, or of 8 hr in either direction. 2. The rhythms of body temperature and excretion of eight urinary constituents were studied before and after the shift, both on a usual nychthemeral routine and during 24 hr when they remained under constant conditions, awake, engaged in light, mainly sedentary activity, and consuming identical food and fluid every hour. 3. The rhythms on nychthemeral routine were defined by fitting cosine curves. On constant routine the rhythm after the shift was cross-correlated with the original rhythm, either with variable delay (or advance) or with an additive mixture between this variably shifted rhythm and the unshifted or a fully shifted rhythm. The process yielding the highest correlation coefficient was accepted as the best descriptor of the nature of adaptation. 4. A combination of two rhythms was observed more often for urinary sodium, chloride and phosphate than for other variables. 5. Adaptation appeared to have proceeded further after westward than eastward shifts, and this difference was particularly noticeable for urinary potassium, sodium and chloride. 6. Partial adaptation usually involved a phase delay, even after an eastward shift when a cumulative delay of 16 hr would be needed to achieve full adaptation and re-entrainment. 7. Observations under nychthemeral conditions often gave a false idea of the degree of adaptation. In particular, after an eastward shift the phase of the rhythms appeared to shift in the appropriate direction when studied under nychthemeral conditions whereas the endogenous oscillator either showed no consistent behaviour or, in the control of urate excretion, a shift in the wrong direction. 8. The implications for people undergoing time shifts, in the course of shift work or transmeridional flights, are indicated. PMID:745108

Comparison of Theory and Experiment on Aeroacoustic Loads and Deflections

NASA Astrophysics Data System (ADS)

Campos, L. M. B. C.; Bourgine, A.; Bonomi, B.

1999-01-01

The correlation of acoustic pressure loads induced by a turbulent wake on a nearby structural panel is considered: this problem is relevant to the acoustic fatigue of aircraft, rocket and satellite structures. Both the correlation of acoustic pressure loads and the panel deflections, were measured in an 8-m diameter transonic wind tunnel. Using the measured correlation of acoustic pressures, as an input to a finite-element aeroelastic code, the panel response was reproduced. The latter was also satisfactorily reproduced, using again the aeroelastic code, with input given by a theoretical formula for the correlation of acoustic pressures; the derivation of this formula, and the semi-empirical parameters which appear in it, are included in this paper. The comparison of acoustic responses in aeroacoustic wind tunnels (AWT) and progressive wave tubes (PWT) shows that much work needs to be done to bridge that gap; this is important since the PWT is the standard test means, whereas the AWT is more representative of real flight conditions but also more demanding in resources. Since this may be the first instance of successful modelling of acoustic fatigue, it may be appropriate to list briefly the essential ``positive'' features and associated physical phenomena: (i) a standard aeroelastic structural code can predict acoustic fatigue, provided that the correlation of pressure loads be adequately specified; (ii) the correlation of pressure loads is determined by the interference of acoustic waves, which depends on the exact evaluation of multiple scattering integrals, involving the statistics of random phase shifts; (iii) for the relatively low frequencies (one to a few hundred Hz) of aeroacoustic fatigue, the main cause of random phase effects is scattering by irregular wakes, which are thin on wavelength scale, and appear as partially reflecting rough interfaces. It may also be appropriate to mention some of the ``negative'' features, to which may be attached illusory importance; (iv) deterministic flow features, even conspicuous or of large scale, such as convection, are not relevant to aeroacoustic fatigue, because they do not produce random phase shifts; (v) local turbulence, of scale much smaller than the wavelength of sound, cannot produce significant random phase shifts, and is also of little consequence to aeroacoustic fatigue; (vi) the precise location of sound sources can become of little consequence, after multiple scattering gives rise to a diffuse sound field; and (vii) there is not much ground for distinction between unsteady flow and sound waves, since at transonic speeds they are both associated with pressures fluctuating in time and space.

Aeolian transport in the field: A comparison of the effects of different surface treatments

NASA Astrophysics Data System (ADS)

Dong, Zhibao; Lv, Ping; Zhang, Zhengcai; Qian, Guangqiang; Luo, Wanyin

2012-05-01

Aeolian transport represents the result of wind-surface interactions, and therefore depends strongly on variations in the characteristics of the sediment surface. We conducted field observations of aeolian transport of typical dune sand in three 80 m × 80 m plots with different surface treatments: gravel-covered sand, enclosed shifting sand, and open (unprotected) shifting sand. The study was performed at the Shapotou Aeolian Experiment Site in the southeastern part of China's Tengger Desert to compare the effects of these different surface treatments on aeolian transport. To do so, we analyzed the flux density profiles and transport rates above each surface. The flux density profiles for all three treatments followed the exponential decay law that was proposed by most previous researchers to describe the saltation flux density profiles. Coefficients of the exponential decay function were defined as a function of the surface and the wind velocity. The enclosed and open plots with shifting sand had similar flux density profiles, but the flux density above gravel-covered plots showed that transport decayed more slowly with increasing height, producing flux density profiles with a higher average saltation height. The transport rate above the three treatment plots tended to increase proportionally with the cube of the mean wind velocity and with the maximum wind velocity during the observation period, but was more strongly correlated with the square of drift potential. Transport rates above the plot with open shifting sand were greater than those above the plots with enclosed shifting sand and the gravel-covered plot.

Electrophysiological evidence for right frontal lobe dominance in spatial visuomotor learning.

PubMed

Lang, W; Lang, M; Kornhuber, A; Kornhuber, H H

1986-02-01

Slow negative potential shifts were recorded together with the error made in motor performance when two different groups of 14 students tracked visual stimuli with their right hand. Various visuomotor tasks were compared. A tracking task (T) in which subjects had to track the stimulus directly, showed no decrease of error in motor performance during the experiment. In a distorted tracking task (DT) a continuous horizontal distortion of the visual feedback had to be compensated. The additional demands of this task required visuomotor learning. Another learning condition was a mirrored-tracking task (horizontally inverted tracking, hIT), i.e. an elementary function, such as the concept of changing left and right was interposed between perception and action. In addition, subjects performed a no-tracking control task (NT) in which they started the visual stimulus without tracking it. A slow negative potential shift was associated with the visuomotor performance (TP: tracking potential). In the learning tasks (DT and hIT) this negativity was significantly enhanced over the anterior midline and in hIT frontally and precentrally over both hemispheres. Comparing hIT and T for every subject, the enhancement of the tracking potential in hIT was correlated with the success in motor learning in frontomedial and bilaterally in frontolateral recordings (r = 0.81-0.88). However, comparing DT and T, such a correlation was only found in frontomedial and right frontolateral electrodes (r = 0.5-0.61), but not at the left frontolateral electrode. These experiments are consistent with previous findings and give further neurophysiological evidence for frontal lobe activity in visuomotor learning. The hemispherical asymmetry is discussed in respect to hemispherical specialization (right frontal lobe dominance in spatial visuomotor learning).

The Relationship between Thermal Comfort and Light Intensity with Sleep Quality and Eye Tiredness in Shift Work Nurses

PubMed Central

Azmoon, Hiva; Dehghan, Habibollah; Akbari, Jafar; Souri, Shiva

2013-01-01

Environmental conditions such as lighting and thermal comfort are influencing factors on sleep quality and visual tiredness. The purpose of this study was the determination of the relationship between thermal comfort and light intensity with the sleep quality and eye fatigue in shift nurses. Method. This cross-sectional research was conducted on 82 shift-work personnel of 18 nursing workstations in Isfahan Al-Zahra Hospital, Iran, in 2012. Heat stress monitoring (WBGT) and photometer (Hagner Model) were used for measuring the thermal conditions and illumination intensity, respectively. To measure the sleep quality, visual tiredness, and thermal comfort, Pittsburg sleep quality index, eye fatigue questionnaire, and thermal comfort questionnaire were used, respectively. The data were analyzed with descriptive statistics, Student's t-test, and Pearson correlation. Results. Correlation between thermal comfort which was perceived from the self-reporting of people with eye tiredness was −0.38 (P = 0.002). Pearson correlation between thermal comfort and sleep quality showed a positive and direct relationship (r = 0.241, P = 0.33) but the correlation between thermal comfort, which was perceived from the self-reporting of shift nurses, and WBGT index was a weak relationship (r = 0.019). Conclusion. Based on the obtained findings, it can be concluded that a defect in environmental conditions such as thermal conditions and light intensity and also lack of appropriate managerial plan for night shift-work nurses are destructive and negative factors for the physical and mental health of this group of practitioners. PMID:23476674

NMR spectroscopy of the ligand binding core of ionotropic glutamate receptor 2 bound to 5-substituted willardiine partial agonists

PubMed Central

Fenwick, Michael K.; Oswald, Robert E.

2008-01-01

Glutamate receptors mediate neuronal intercommunication in the central nervous system by coupling extracellular neurotransmitter-receptor interactions to ion channel conductivity. To gain insight into structural and dynamical factors that underlie this coupling, solution NMR experiments were performed on the bi-lobed ligand-binding core of glutamate receptor 2 in complexes with a set of willardiine partial agonists. These agonists are valuable for studying structure-function relationships because their 5-position substituent size is correlated with ligand efficacy and extent of receptor desensitization whereas the substituent electronegativity is correlated with ligand potency. NMR results show that the protein backbone amide chemical shift deviations correlate mainly with efficacy and extent of desensitization. Pronounced deviations occur at specific residues in the ligand-binding site and in the two helical segments that join the lobes by a disulfide bond. Experiments detecting conformational exchange show that micro- to millisecond timescale motions also occur near the disulfide bond and vary largely with efficacy and extent of desensitization. These results thus identify regions displaying structural and dynamical dissimilarity arising from differences in ligand-protein interactions and lobe closure which may play a critical role in receptor response. Furthermore, measures of line broadening and conformational exchange for a portion of the ligand-binding site correlate with ligand EC50 data. These results do not have any correlate in the currently available crystal structures and thus provide a novel view of ligand-binding events that may be associated with agonist potency differences. PMID:18387631

Motor skill failure or flow-experience? Functional brain asymmetry and brain connectivity in elite and amateur table tennis players.

PubMed

Wolf, Sebastian; Brölz, Ellen; Keune, Philipp M; Wesa, Benjamin; Hautzinger, Martin; Birbaumer, Niels; Strehl, Ute

2015-02-01

Functional hemispheric asymmetry is assumed to constitute one underlying neurophysiological mechanism of flow-experience and skilled psycho-motor performance in table tennis athletes. We hypothesized that when initiating motor execution during motor imagery, elite table tennis players show higher right- than left-hemispheric temporal activity and stronger right temporal-premotor than left temporal-premotor theta coherence compared to amateurs. We additionally investigated, whether less pronounced left temporal cortical activity is associated with more world rank points and more flow-experience. To this aim, electroencephalographic data were recorded in 14 experts and 15 amateur table tennis players. Subjects watched videos of an opponent serving a ball and were instructed to imagine themselves responding with a specific table tennis stroke. Alpha asymmetry scores were calculated by subtracting left from right hemispheric 8-13 Hz alpha power. 4-7 Hz theta coherence was calculated between temporal (T3/T4) and premotor (Fz) cortex. Experts showed a significantly stronger shift towards lower relative left-temporal brain activity compared to amateurs and a significantly stronger right temporal-premotor coherence than amateurs. The shift towards lower relative left-temporal brain activity in experts was associated with more flow-experience and lower relative left temporal activity was correlated with more world rank points. The present findings suggest that skilled psycho-motor performance in elite table tennis players reflect less desynchronized brain activity at the left hemisphere and more coherent brain activity between fronto-temporal and premotor oscillations at the right hemisphere. This pattern probably reflect less interference of irrelevant communication of verbal-analytical with motor-control mechanisms which implies flow-experience and predict world rank in experts. Copyright © 2015 Elsevier B.V. All rights reserved.

Language Shift of Taiwan's Indigenous Peoples: A Case Study of Kanakanavu and Saaroa

ERIC Educational Resources Information Center

Liu, Dorinda Tsai-Hsiu; Chang, Ying-Hwa; Li, Paul Jen-Kuei; Lin, Ji-Ping

2015-01-01

This study covers two issues: (1) the language shift process relating to two highly endangered aboriginal languages of Taiwan and (2) the correlations between some variables and their language shift. Both Kanakanavu and Saaroa peoples underwent two waves of migration: (1) a massive in-migration of another Formosan ethnic group (Bunun people) in…

MBARI CANON Experiment Visualization and Analysis

NASA Astrophysics Data System (ADS)

Fatland, R.; Oscar, N.; Ryan, J. P.; Bellingham, J. G.

2013-12-01

We describe the task of understanding a marine drift experiment conducted by MBARI in Fall 2012 ('CANON'). Datasets were aggregated from a drifting ADCP, from the MBARI Environmental Sample Processor, from Long Range Autonomous Underwater Vehicles (LRAUVs), from other in situ sensors, from NASA and NOAA remote sensing platforms, from moorings, from shipboard CTD casts and from post-experiment metagenomic analysis. We seek to combine existing approaches to data synthesis -- visual inspection, cross correlation and co.-- with three new ideas. This approach has the purpose of differentiating biological signals into three causal categories: Microcurrent advection, physical factors and microbe metabolism. Respective examples are aberrance from Lagrangian frame drift due to windage, changes in solar flux over several days, and microbial population responses to shifts in nitrate concentration. The three ideas we implemented are as follows: First, we advect LRAUV data to look for patterns in time series data for conserved quanitities such as salinity. We investigate whether such patterns can be used to support or undermine the premise of Lagrangian motion of the experiment ensemble. Second we built a set of configurable filters that enable us to visually isolate segments of data: By type, value, time, anomaly and location. Third we associated data hypotheses with a Bayesian inferrence engine for the purpose of model validation, again across sections taken from within the complete data complex. The end result is towards a free-form exploration of experimental data with low latency: from question to view, from hypothesis to test (albeit with considerable preparatory effort.) Preliminary results show the three causal categories shifting in relative influence.

Linguistic attention control: attention shifting governed by grammaticized elements of language.

PubMed

Taube-Schiff, Marlene; Segalowitz, Norman

2005-05-01

In 2 experiments, the authors investigated attention control for tasks involving the processing of grammaticized linguistic stimuli (function words) contextualized in sentence fragments. Attention control was operationalized as shift costs obtained with adult speakers of English in an alternating-runs experimental design (R. D. Rogers & S. Monsell, 1995). Experiment 1 yielded significant attention shift costs between tasks involving judgments about the meanings of grammatical function words. The authors used a 3-stage experimental design (G. Wylie & A. Allport, 2000), and the emerging pattern of results implicated task set reconfiguration and not task set inertia in these shift costs. Experiment 2 further demonstrated that shift costs were lower when the tasks involved shared attentional resources (processing the same grammatical dimension) versus unshared resources (different grammatical dimensions). The authors discuss the results from a cognitive linguistic perspective and for their implications for the view that language itself can serve a special attention-directing function.

A novel fast phase correlation algorithm for peak wavelength detection of Fiber Bragg Grating sensors.

PubMed

Lamberti, A; Vanlanduit, S; De Pauw, B; Berghmans, F

2014-03-24

Fiber Bragg Gratings (FBGs) can be used as sensors for strain, temperature and pressure measurements. For this purpose, the ability to determine the Bragg peak wavelength with adequate wavelength resolution and accuracy is essential. However, conventional peak detection techniques, such as the maximum detection algorithm, can yield inaccurate and imprecise results, especially when the Signal to Noise Ratio (SNR) and the wavelength resolution are poor. Other techniques, such as the cross-correlation demodulation algorithm are more precise and accurate but require a considerable higher computational effort. To overcome these problems, we developed a novel fast phase correlation (FPC) peak detection algorithm, which computes the wavelength shift in the reflected spectrum of a FBG sensor. This paper analyzes the performance of the FPC algorithm for different values of the SNR and wavelength resolution. Using simulations and experiments, we compared the FPC with the maximum detection and cross-correlation algorithms. The FPC method demonstrated a detection precision and accuracy comparable with those of cross-correlation demodulation and considerably higher than those obtained with the maximum detection technique. Additionally, FPC showed to be about 50 times faster than the cross-correlation. It is therefore a promising tool for future implementation in real-time systems or in embedded hardware intended for FBG sensor interrogation.

Shifting from Production to Service to Experience-Based Operations

NASA Astrophysics Data System (ADS)

Angelis, Jannis; de Lima, Edson Pinheiro

This chapter covers the shift in focus of value added business operations from ­production to services, and in turn, to experience-based operations where customer involvement itself becomes part of the offering. The shift has significant implications for how businesses are managed. The greater service focus affects the firm's unique value proposition, which necessitates considerations on strategy, supplier relations, post-sale offerings and so on. Meanwhile, the inclusion of customer ­experiences affect the way operations are designed and employed so that these are structurally systematically captured and capitalised.

GPUs benchmarking in subpixel image registration algorithm

NASA Astrophysics Data System (ADS)

Sanz-Sabater, Martin; Picazo-Bueno, Jose Angel; Micó, Vicente; Ferrerira, Carlos; Granero, Luis; Garcia, Javier

2015-05-01

Image registration techniques are used among different scientific fields, like medical imaging or optical metrology. The straightest way to calculate shifting between two images is using the cross correlation, taking the highest value of this correlation image. Shifting resolution is given in whole pixels which cannot be enough for certain applications. Better results can be achieved interpolating both images, as much as the desired resolution we want to get, and applying the same technique described before, but the memory needed by the system is significantly higher. To avoid memory consuming we are implementing a subpixel shifting method based on FFT. With the original images, subpixel shifting can be achieved multiplying its discrete Fourier transform by a linear phase with different slopes. This method is high time consuming method because checking a concrete shifting means new calculations. The algorithm, highly parallelizable, is very suitable for high performance computing systems. GPU (Graphics Processing Unit) accelerated computing became very popular more than ten years ago because they have hundreds of computational cores in a reasonable cheap card. In our case, we are going to register the shifting between two images, doing the first approach by FFT based correlation, and later doing the subpixel approach using the technique described before. We consider it as `brute force' method. So we will present a benchmark of the algorithm consisting on a first approach (pixel resolution) and then do subpixel resolution approaching, decreasing the shifting step in every loop achieving a high resolution in few steps. This program will be executed in three different computers. At the end, we will present the results of the computation, with different kind of CPUs and GPUs, checking the accuracy of the method, and the time consumed in each computer, discussing the advantages, disadvantages of the use of GPUs.

Fourier-Domain Shift Matching: A Robust Time-of-Flight Approach for Shear Wave Speed Estimation.

PubMed

Rosen, David; Jiang, Jingfeng

2018-05-01

Our primary objective of this work was to design and test a new time-of-flight (TOF) method that allows measurements of shear wave speed (SWS) following impulsive excitation in soft tissues. Particularly, under the assumption of the local plane shear wave, this work named the Fourier-domain shift matching (FDSM) method, estimates SWS by aligning a series of shear waveforms either temporally or spatially using a solution space deduced by characteristic curves of the well-known 1-D wave equation. The proposed SWS estimation method was tested using computer-simulated data, and tissue-mimicking phantom and ex vivo tissue experiments. Its performance was then compared with three other known TOF methods: lateral time-to-peak (TTP) method with robust random sampling consensus (RANSAC) fitting method, Radon sum transformation method, and a modified cross correlation method. Hereafter, these three TOF methods are referred to as the TTP-RANSAC, Radon sum, and X-corr methods, respectively. In addition to an adapted form of the 2-D Fourier transform (2-D FT)-based method in which the (group) SWS was approximated by averaging phase SWS values was considered for comparison. Based on data evaluated, we found that the overall performance of the above-mentioned temporal implementation of the proposed FDSM method was most similar to the established Radon sum method (correlation = 0.99, scale factor = 1.03, and mean difference = 0.07 m/s), and the 2-D FT (correlation = 0.98, scale factor = 1.00, and mean difference = 0.10 m/s) at high signal quality. However, results obtained from the 2-D FT method diverged (correlation = 0.201) from these of the proposed temporal implementation in the presence of diminished signal quality, whereas the agreement between the Radon sum approach and the proposed temporal implementation largely remained the same (correlation = 0.98).

Black carbon aerosol-induced Northern Hemisphere tropical expansion

DOE PAGES

Kovilakam, Mahesh; Mahajan, Salil

2015-06-23

Global climate models (GCMs) underestimate the observed trend in tropical expansion. Recent studies partly attribute it to black carbon (BC) aerosols, which are poorly represented in GCMs. In this paper, we conduct a suite of idealized experiments with the Community Atmosphere Model version 4 coupled to a slab ocean model forced with increasing BC concentrations covering a large swath of the estimated range of current BC radiative forcing while maintaining their spatial distribution. The Northern Hemisphere (NH) tropics expand poleward nearly linearly as BC radiative forcing increases (0.7° W -1 m 2), indicating that a realistic representation of BC couldmore » reduce GCM biases. We find support for the mechanism where BC-induced midlatitude tropospheric heating shifts the maximum meridional tropospheric temperature gradient poleward resulting in tropical expansion. Finally, we also find that the NH poleward tropical edge is nearly linearly correlated with the location of the Intertropical Convergence Zone, which shifts northward in response to increasing BC.« less

Decadal covariability of Atlantic SSTs and western Amazon dry-season hydroclimate in observations and CMIP5 simulations

NASA Astrophysics Data System (ADS)

Fernandes, Katia; Giannini, Alessandra; Verchot, Louis; Baethgen, Walter; Pinedo-Vasquez, Miguel

2015-08-01

The unusual severity and return time of the 2005 and 2010 dry-season droughts in western Amazon is attributed partly to decadal climate fluctuations and a modest drying trend. Decadal variability of western Amazon hydroclimate is highly correlated to the Atlantic sea surface temperature (SST) north-south gradient (NSG). Shifts of dry and wet events frequencies are also related to the NSG phase, with a 66% chance of 3+ years of dry events per decade when NSG > 0 and 19% when NSG < 0. The western Amazon and NSG decadal covariability is well reproduced in general circulation models (GCMs) historical (HIST) and preindustrial control (PIC) experiments of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The HIST and PIC also reproduce the shifts in dry and wet events probabilities, indicating potential for decadal predictability based on GCMs. Persistence of the current NSG positive phase favors above normal frequency of western Amazon dry events in coming decades.

When the going gets tough...: Self-motivation is associated with invigoration and fun.

PubMed

Kazén, Miguel; Kuhl, Julius; Leicht, Eva-Maria

2015-11-01

Personality systems interaction (PSI) theory postulates two executive control modes in volitional action: Self-control and self-regulation (self-motivation). Self-control should deplete energy whereas self-motivation should maintain energy and result in invigoration. There were three groups of participants: Self-control, self-motivation, and pretend, who performed a resource-demanding Stroop-Shift and an anagram task. Performance and energy expenditure were examined in each task. Compared to the other groups, the self-motivation group showed increments in blood glucose throughout the experiment, indicating invigoration, and had better performance on the difficult Stroop-Shift task than the self-control group. Additionally, for the self-motivation group anagram performance correlated with less effort and ease of concentration and was moderated by fun in the task. These results are consonant with the predictions of PSI and self-determination theories. It is concluded that self-control depletes resources whereas self-motivation is associated with invigoration in carrying resource-demanding tasks.

Coherent 40-Hz Oscillation Characterizes Dream State in Humans

NASA Astrophysics Data System (ADS)

Llinas, Rodolfo; Ribary, Urs

1993-03-01

Magnetic recording from five normal human adults demonstrates large 40-Hz coherent magnetic activity in the awake and in rapid-eye-movement (REM) sleep states that is very reduced during delta sleep (deep sleep characterized by delta waves in the electroencephalogram). This 40-Hz magnetic oscillation has been shown to be reset by sensory stimuli in the awake state. Such resetting is not observed during REM or delta sleep. The 40 Hz in REM sleep is characterized, as is that in the awake state, by a fronto-occiptal phase shift over the head. This phase shift has a maximum duration of thickapprox12-13 msec. Because 40-Hz oscillation is seen in wakefulness and in dreaming, we propose it to be a correlate of cognition, probably resultant from coherent 40-Hz resonance between thalamocortical-specific and nonspecific loops. Moreover, we proposed that the specific loops give the content of cognition, and a nonspecific loop gives the temporal binding required for the unity of cognitive experience.

Gonadal morphogenesis and gene expression in reptiles with temperature-dependent sex determination.

PubMed

Merchant-Larios, H; Díaz-Hernández, V; Marmolejo-Valencia, A

2010-01-01

In reptiles with temperature-dependent sexual determination, the thermosensitive period (TSP) is the interval in which the sex is defined during gonadal morphogenesis. One-shift experiments in a group of eggs define the onset and the end of the TSP as all and none responses, respectively. Timing for sex-undetermined (UG) and -determined gonads (DG) differs at male- (MPT) or female-producing temperatures (FPT). During the TSP a decreasing number of embryos respond to temperature shifts indicating that in this period embryos with both UG and DG exist. Although most UG correspond to undifferentiated gonads, some embryos extend UG after the onset of histological differentiation. Thus, temperature affects gonadal cells during the process of morphogenesis, but timing of commitment depends on individual embryos. A correlation between gonadal morphogenesis, TSP, and gene expression suggests that determination of the molecular pathways modulated by temperature in epithelial cells (surface epithelium and medullary cords) holds the key for a unifying hypothesis on temperature-dependent sex determination. (c) 2010 S. Karger AG, Basel.

Computation of Chemical Shifts for Paramagnetic Molecules: A Laboratory Experiment for the Undergraduate Curriculum

ERIC Educational Resources Information Center

Pritchard, Benjamin P.; Simpson, Scott; Zurek, Eva; Autschbach, Jochen

2014-01-01

A computational experiment investigating the [superscript 1]H and [superscript 13]C nuclear magnetic resonance (NMR) chemical shifts of molecules with unpaired electrons has been developed and implemented. This experiment is appropriate for an upper-level undergraduate laboratory course in computational, physical, or inorganic chemistry. The…

Activity-based prospective memory in schizophrenia.

PubMed

Kumar, Devvarta; Nizamie, S Haque; Jahan, Masroor

2008-05-01

The study reports activity-based prospective memory as well as its clinical and neuropsychological correlates in schizophrenia. A total of 42 persons diagnosed with schizophrenia and 42 healthy controls were administered prospective memory, set-shifting, and verbal working memory tasks. The schizophrenia group was additionally administered various psychopathology rating scales. Group differences, with poorer performances of the schizophrenia group, were observed on the measures of prospective memory, working memory, and set shifting. The performance on prospective memory tasks correlated with the performance levels on verbal working memory and set-shifting tasks but not with the clinical measures. This study demonstrated impaired activity-based prospective memory in schizophrenia. The impairment can be due to deficits in various neuropsychological domains.

Frequency shifts in gravitational resonance spectroscopy

DOE PAGES

Baeßler, S.; Nesvizhevsky, V. V.; Pignol, G.; ...

2015-02-25

Quantum states of ultracold neutrons in a gravitational field are characterized through gravitational resonance spectroscopy. This paper discusses systematic effects that appear in the spectroscopic measurements. The discussed frequency shifts-which we call the Stern-Gerlach shift, interference shift, and spectator-state shift-appear in conceivable measurement schemes and have general importance. Lastly, these shifts have to be taken into account in precision experiments.

Implementing a night-shift clinical nurse specialist.

PubMed

Becker, Dawn Marie

2013-01-01

Night-shift nurses receive fewer educational opportunities and less administrative support than do day-shift staff, tend to be newer, with less experience and fewer resources, and experience greater turnover rates, stress, and procedural errors. In an attempt to bridge the gap between day- and night-shift nursing, a night-shift clinical nurse specialist (CNS) position was created in a midsized, community teaching hospital. The goal was to provide an advanced practice presence to improve patient outcomes, communication, education, and cost-effectiveness. The night-shift CNS participated in nursing education and skill certifications, communicated new procedures and information, and created a communication committee specifically for night-shift nurses. Through regular rounding and on-call notification, the CNS was available to every area of the hospital for consultation and clinical assistance and assisted with rapid responses, codes, and traumas. Providing education during night shift reduced overtime costs and increased morale, positively affecting turnover rates. The night-shift CNS position has improved morale and equalized support for night-shift nurses. More research, most notably in specific night-shift metrics, is necessary, and with the implementation of the role in additional facilities, more can be understood about improving patient care and nursing staff satisfaction during night shift.

Phase correction, phase resetting, and phase shifts after subliminal timing perturbations in sensorimotor synchronization.

PubMed

Repp, B H

2001-06-01

Recent studies of synchronized finger tapping have shown that perceptually subliminal phase shifts in an auditory sequence are rapidly compensated for in the motor activity (B. H. Repp, 2000a). Experiment 1 used a continuation-tapping task to confirm that this compensation is indeed a phase correction, not an adjustment of the central timekeeper period. Experiments 2-5 revealed that this phase correction occurs even when there is no ordinary sensorimotor asynchrony--when the finger taps are in antiphase or arbitrary phase relative to the auditory sequence (Experiments 2 and 3) or when the tap coinciding with the sequence phase shift is withheld (Experiments 4 and 5). The phase correction observed in the latter conditions was instantaneous, which suggests that phase resetting occurs when the motor activity is discontinuous. A prolonged phase shift suggestive of overcompensation was observed in some conditions, which poses a challenge to pure phase correction models.

The role of the cerebellum in sub- and supraliminal error correction during sensorimotor synchronization: evidence from fMRI and TMS.

PubMed

Bijsterbosch, Janine D; Lee, Kwang-Hyuk; Hunter, Michael D; Tsoi, Daniel T; Lankappa, Sudheer; Wilkinson, Iain D; Barker, Anthony T; Woodruff, Peter W R

2011-05-01

Our ability to interact physically with objects in the external world critically depends on temporal coupling between perception and movement (sensorimotor timing) and swift behavioral adjustment to changes in the environment (error correction). In this study, we investigated the neural correlates of the correction of subliminal and supraliminal phase shifts during a sensorimotor synchronization task. In particular, we focused on the role of the cerebellum because this structure has been shown to play a role in both motor timing and error correction. Experiment 1 used fMRI to show that the right cerebellar dentate nucleus and primary motor and sensory cortices were activated during regular timing and during the correction of subliminal errors. The correction of supraliminal phase shifts led to additional activations in the left cerebellum and right inferior parietal and frontal areas. Furthermore, a psychophysiological interaction analysis revealed that supraliminal error correction was associated with enhanced connectivity of the left cerebellum with frontal, auditory, and sensory cortices and with the right cerebellum. Experiment 2 showed that suppression of the left but not the right cerebellum with theta burst TMS significantly affected supraliminal error correction. These findings provide evidence that the left lateral cerebellum is essential for supraliminal error correction during sensorimotor synchronization.

Inorganic phosphorus and nitrogen modify composition and diversity of microbial communities in water of mesotrophic lake.

PubMed

Chróst, Ryszard J; Adamczewski, Tomasz; Kalinowska, Krystyna; Skowrońska, Agnieszka

2009-01-01

The effects of inorganic nutrients (N, P) enrichment of mesotrophic lake water on changes in bacterial and protistan (heterotrophic nanoflagellates and ciliates) communities compositions were studied in the mesocosm experiment. Phosphorus (PO4(3-)) and nitrogen (NH4+) alone and in combination were added to three types of experimental mesocosms. Mesocosms results suggested that simultaneous addition of P and N stimulated phytoplankton growth and production rates of bacterial biomass its turnover rate. Strong positive correlations between chlorophyll a and bacterial secondary production rates suggested that bacteria were mainly controlled by organic substrates released in course ofphytoplankton photosynthesis. Both nutrients increased distinctly protistan biomass and resulted in the shift in ciliate community composition from algivorous to large omnivorous species. The response of bacterial numbers and biomass to nutrients addition was less evident. However, intensive grazing caused their dynamic changes. Fluorescence in situ hybridization (FISH) revealed only small changes in bacterial taxonomic composition. There was an apparent shift in dominance from Cytophaga-Flavobacterium to the Alphaproteobacteria group in the mesocosm with simultaneous addition of P and N, which positively related to increased abundance of bacterivorous protists. Experiment demonstrated that inorganic N and P nutrients directly influenced the bottom-down control of microbial communities, which had a crucial effect on morphological diversity of bacteria.

Age differences in strategy shift: retrieval avoidance or general shift reluctance?

PubMed

Frank, David J; Touron, Dayna R; Hertzog, Christopher

2013-09-01

Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults' demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch's (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attending to only that part of the stimulus. We adapted the AVT to include conditions that promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults' strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits.

Age Differences in Strategy Shift: Retrieval Avoidance or General Shift Reluctance?

PubMed Central

Frank, David J.; Touron, Dayna R.; Hertzog, Christopher

2013-01-01

Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults’ demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch’s (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attend only to that part of the stimulus. We adapted the AVT to include conditions which promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults’ strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits. PMID:23088195

Anticipating regime shifts in gene expression: The case of an autoactivating positive feedback loop

NASA Astrophysics Data System (ADS)

Sharma, Yogita; Dutta, Partha Sharathi; Gupta, A. K.

2016-03-01

Considerable evidence suggests that anticipating sudden shifts from one state to another in bistable dynamical systems is a challenging task; examples include ecosystems, financial markets, and complex diseases. In this paper, we investigate the effects of additive, multiplicative, and cross-correlated stochastic perturbations on determining the regime shifts in a bistable gene regulatory system, which gives rise to two distinct states of low and high concentrations of protein. We obtain the stationary probability density and mean first-passage time of the system. We show that increasing the additive (multiplicative) noise intensity induces a regime shift from a low (high) to a high (low) protein concentration state. However, an increase in the cross-correlation intensity always induces regime shifts from a high to a low protein concentration state. For both bifurcation-induced (often called the tipping point) and noise-induced (called stochastic switching) regime shifts, we further explore the robustness of recently developed critical-down-based early warning signal (EWS) indicators (e.g., rising variance and lag-1 autocorrelation) on our simulated time-series data. We identify that using EWS indicators, prediction of an impending bifurcation-induced regime shift is relatively easier than that of a noise-induced regime shift in the considered system. Moreover, the success of EWS indicators also strongly depends upon the nature of the noise.

Development of 19F-NMR chemical shift detection of DNA B-Z equilibrium using 19F-NMR.

PubMed

Nakamura, S; Yang, H; Hirata, C; Kersaudy, F; Fujimoto, K

2017-06-28

Various DNA conformational changes are in correlation with biological events. In particular, DNA B-Z equilibrium showed a high correlation with translation and transcription. In this study, we developed a DNA probe containing 5-trifluoromethylcytidine or 5-trifluoromethylthymidine to detect DNA B-Z equilibrium using 19 F-NMR. Its probe enabled the quantitative detection of B-, Z-, and ss-DNA based on 19 F-NMR chemical shift change.

Late chronotype and high social jetlag are associated with burnout in evening-shift workers: Assessment using the Chinese-version MCTQshift.

PubMed

Cheng, Wan-Ju; Hang, Liang-Wen

2018-04-16

Chronotypes are associated with shift work tolerance and sleep in shift workers, and sleep mediates the impact of shift work on mental health. However, the role of chronotype in the association between shift work and mental health has not been clarified. In this study, we aimed to examine the association between chronotype and burnout in shift workers, using the validated Munich ChronoType Questionnaire for shift workers (MCTQ shift ). A total of 288 shift workers with irregular shift frequencies were recruited and completed the Chinese-version MCTQ shift and the Morningness-Eveningness Questionnaire (MEQ). Chronotypes were assessed by the calculation of corrected mid-sleep time (MSF SC ) from mid-sleep time on free days (MSF) based on their exact shift schedules. Another 26 evening-shift nurses were monitored with actigraphy for at least two consecutive evening shifts and the following two free days. Burnout was evaluated using the Copenhagen Burnout Inventory. We found that MSF E SC , MSF E and mid-sleep time on workdays (MSW E ) had normal distributions and correlated significantly with MEQ scores (r = - 0.47, -0.45 and -0.47, respectively; all p < 0.001). MSW was more closely correlated with actigraphy-derived mid-sleep time on the free day before workdays than that on workdays (r = 0.61 and 0.48, respectively, p < 0.05). Sleep duration was significantly longer on workdays among evening-shift workers who slept late on workdays than those who slept early (β = 0.59, p < 0.001). After demographic and work characteristics were adjusted for in linear regression models, late chronotype and high social jetlag were associated with burnout scores in evening-shift workers. In conclusion, the Chinese-version MCTQ shift is a valid tool for chronotype assessment. Interventions to improve sleep in shift workers should be tailored to chronotype due to variations in sleep behavior. Late chronotype may be an inherent feature of mental health problems, because the association with burnout was significant in both day workers in previous studies and shift workers.

Walk, Look, Remember: The Influence of the Gallery's Spatial Layout on Human Memory for an Art Exhibition.

PubMed

Krukar, Jakub

2014-09-01

The spatial organisation of museums and its influence on the visitor experience has been the subject of numerous studies. Previous research, despite reporting some actual behavioural correlates, rarely had the possibility to investigate the cognitive processes of the art viewers. In the museum context, where spatial layout is one of the most powerful curatorial tools available, attention and memory can be measured as a means of establishing whether or not the gallery fulfils its function as a space for contemplating art. In this exploratory experiment, 32 participants split into two groups explored an experimental, non-public exhibition and completed two unanticipated memory tests afterwards. The results show that some spatial characteristics of an exhibition can inhibit the recall of pictures and shift the focus to perceptual salience of the artworks.

Walk, Look, Remember: The Influence of the Gallery’s Spatial Layout on Human Memory for an Art Exhibition

PubMed Central

Krukar, Jakub

2014-01-01

The spatial organisation of museums and its influence on the visitor experience has been the subject of numerous studies. Previous research, despite reporting some actual behavioural correlates, rarely had the possibility to investigate the cognitive processes of the art viewers. In the museum context, where spatial layout is one of the most powerful curatorial tools available, attention and memory can be measured as a means of establishing whether or not the gallery fulfils its function as a space for contemplating art. In this exploratory experiment, 32 participants split into two groups explored an experimental, non-public exhibition and completed two unanticipated memory tests afterwards. The results show that some spatial characteristics of an exhibition can inhibit the recall of pictures and shift the focus to perceptual salience of the artworks. PMID:25379276

Time dependent density functional theory study of the near-edge x-ray absorption fine structure of benzene in gas phase and on metal surfaces.

PubMed

Asmuruf, Frans A; Besley, Nicholas A

2008-08-14

The near-edge x-ray absorption fine structure of benzene in the gas phase and adsorbed on the Au(111) and Pt(111) surfaces is studied with time dependent density functional theory. Excitation energies computed with hybrid exchange-correlation functionals are too low compared to experiment. However, after applying a constant shift the spectra are in good agreement with experiment. For benzene on the Au(111) surface, two bands arising from excitation to the e(2u)(pi(*)) and b(2g)(pi(*)) orbitals of benzene are observed for photon incidence parallel to the surface. On Pt(111) surface, a broader band arises from excitation to benzene orbitals that are mixed with the surface and have both sigma(*)(Pt-C) and pi(*) characters.

Proton-Proton Elastic Scattering Excitation Functions at Intermediate Energies: Cross Sections and Analyzing Powers

NASA Astrophysics Data System (ADS)

Hinterberger, F.; Rohdjeß, H.; Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Büßer, K.; Busch, M.; Colberg, T.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Eversheim, P. D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Groß-Hardt, R.; Hinterberger, F.; Jahn, R.; Jonas, E.; Krause, H.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Meinerzhagen, A.; Nähle, O.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Trelle, H. J.; Weise, E.; Wellinghausen, A.; Woller, K.; Ziegler, R.

2000-01-01

The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power AN and the polarization correlation parameters ANN, ASS and ASL are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent dσ/dΩ and AN data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.

Correlation of Device Performance and Fermi Level Shift in the Emitting Layer of Organic Light-Emitting Diodes with Amine-Based Electron Injection Layers.

PubMed

Stolz, Sebastian; Lemmer, Uli; Hernandez-Sosa, Gerardo; Mankel, Eric

2018-03-14

We investigate three amine-based polymers, polyethylenimine and two amino-functionalized polyfluorenes, as electron injection layers (EILs) in organic light-emitting diodes (OLEDs) and find correlations between the molecular structure of the polymers, the electronic alignment at the emitter/EIL interface, and the resulting device performance. X-ray photoelectron spectroscopy measurements of the emitter/EIL interface indicate that all three EIL polymers induce an upward shift of the Fermi level in the emitting layer close to the interface similar to n-type doping. The absolute value of this Fermi level shift, which can be explained by an electron transfer from the EIL polymers into the emitting layer, correlates with the number of nitrogen-containing groups in the side chains of the polymers. Whereas polyethylenimine (PEI) and one of the investigated polyfluorenes (PFCON-C) have six such groups per monomer unit, the second investigated polyfluorene (PFN) only possesses two. Consequently, we measure Fermi level shifts of 0.5-0.7 eV for PEI and PFCON-C and only 0.2 eV for PFN. As a result of these Fermi level shifts, the energetic barrier for electron injection is significantly lowered and OLEDs which comprise PEI or PFCON-C as an EIL exhibit a more than twofold higher luminous efficacy than OLEDs with PFN.

A theoretical perspective of the nature of hydrogen-bond types - the atoms in molecules approach

NASA Astrophysics Data System (ADS)

Vijaya Pandiyan, B.; Kolandaivel, P.; Deepa, P.

2014-06-01

Hydrogen bonds and their strength were analysed based on their X-H proton-donor bond properties and the parameters of the H-Y distance (Y proton acceptor). Strong, moderate and weak interactions in hydrogen-bond types were verified through the proton affinities of bases (PA), deprotanation enthalpies of acids (DPE) and the chemical shift (σ). The aromaticity and anti-aromaticity were analysed by means of the NICS (0) (nucleus-independent chemical shift), NICS (1) and ΔNICS (0), ΔNICS (1) of hydrogen-bonded molecules. The strength of a hydrogen bond depends on the capacity of hydrogen atom engrossing into the electronegative acceptor atom. The correlation between the above parameters and their relations were discussed through curve fitting. Bader's theory of atoms in molecules has been applied to estimate the occurrence of hydrogen bonds through eight criteria reported by Popelier et al. The lengths and potential energy shifts have been found to have a strong negative linear correlation, whereas the lengths and Laplacian shifts have a strong positive linear correlation. This study illustrates the common factors responsible for strong, moderate and weak interactions in hydrogen-bond types.

Evaluation of the relation between evapotranspiration and normalized difference vegetation index for downscaling the simplified surface energy balance model

USGS Publications Warehouse

Haynes, Jonathan V.; Senay, Gabriel B.

2012-01-01

The Simplified Surface Energy Balance (SSEB) model uses satellite imagery to estimate actual evapotranspiration (ETa) at 1-kilometer resolution. SSEB ETa is useful for estimating irrigation water use; however, resolution limitations restrict its use to regional scale applications. The U.S. Geological Survey investigated the downscaling potential of SSEB ETa from 1 kilometer to 250 meters by correlating ETa with the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer instrument (MODIS). Correlations were studied in three arid to semiarid irrigated landscapes of the Western United States (Escalante Valley near Enterprise, Utah; Palo Verde Valley near Blythe, California; and part of the Columbia Plateau near Quincy, Washington) during several periods from 2002 to 2008. Irrigation season ETa-NDVI correlations were lower than expected, ranging from R2 of 0.20 to 0.61 because of an eastward 2–3 kilometer shift in ETadata. The shift is due to a similar shift identified in the land-surface temperature (LST) data from the MODIS Terra satellite, which is used in the SSEB model. Further study is needed to delineate the Terra LST shift, its effect on SSEB ETa, and the relation between ETa and NDVI.

Effect of Fuel Composition on Particulate Matter Emissions from a Gasoline Direct Injection Engine

NASA Astrophysics Data System (ADS)

Smallwood, Bryden Alexander

The effects of fuel composition on reducing PM emissions were investigated using a Ford Focus wall-guided gasoline direct injection engine (GDI). Initial results with a 65% isooctane and 35% toluene blend showed significant reductions in PM emissions. Further experiments determined that this decrease was due to a lack of light-end components in that fuel blend. Tests with pentane content lower than 15% were found to have PN concentrations 96% lower than tests with 20% pentane content. This indicates that there is a shift in mode of soot production. Pentane significantly increases the vapour pressure of the fuel blend, potentially resulting in surface boiling, less homogeneous mixtures, or decreased fuel rebound from the piston. PM mass measurements and PN Index values both showed strong correlations with the PN concentration emissions. In the gaseous exhaust, THC, pentane, and 1,3 butadiene showed strong correlations with the PM emissions.

Pressure response of protein backbone structure. Pressure-induced amide 15N chemical shifts in BPTI.

PubMed Central

Akasaka, K.; Li, H.; Yamada, H.; Li, R.; Thoresen, T.; Woodward, C. K.

1999-01-01

The effect of pressure on amide 15N chemical shifts was studied in uniformly 15N-labeled basic pancreatic trypsin inhibitor (BPTI) in 90%1H2O/10%2H2O, pH 4.6, by 1H-15N heteronuclear correlation spectroscopy between 1 and 2,000 bar. Most 15N signals were low field shifted linearly and reversibly with pressure (0.468 +/- 0.285 ppm/2 kbar), indicating that the entire polypeptide backbone structure is sensitive to pressure. A significant variation of shifts among different amide groups (0-1.5 ppm/2 kbar) indicates a heterogeneous response throughout within the three-dimensional structure of the protein. A tendency toward low field shifts is correlated with a decrease in hydrogen bond distance on the order of 0.03 A/2 kbar for the bond between the amide nitrogen atom and the oxygen atom of either carbonyl or water. The variation of 15N shifts is considered to reflect site-specific changes in phi, psi angles. For beta-sheet residues, a decrease in psi angles by 1-2 degrees/2 kbar is estimated. On average, shifts are larger for helical and loop regions (0.553 +/- 0.343 and 0.519 +/- 0.261 ppm/2 kbar, respectively) than for beta-sheet (0.295 +/- 0.195 ppm/2 kbar), suggesting that the pressure-induced structural changes (local compressibilities) are larger in helical and loop regions than in beta-sheet. Because compressibility is correlated with volume fluctuation, the result is taken to indicate that the volume fluctuation is larger in helical and loop regions than in beta-sheet. An important aspect of the volume fluctuation inferred from pressure shifts is that they include motions in slower time ranges (less than milliseconds) in which many biological processes may take place. PMID:10548039

The change in spatial distribution of upper trapezius muscle activity is correlated to contraction duration.

PubMed

Farina, Dario; Leclerc, Frédéric; Arendt-Nielsen, Lars; Buttelli, Olivier; Madeleine, Pascal

2008-02-01

The aim of the study was to confirm the hypothesis that the longer a contraction is sustained, the larger are the changes in the spatial distribution of muscle activity. For this purpose, surface electromyographic (EMG) signals were recorded with a 13 x 5 grid of electrodes from the upper trapezius muscle of 11 healthy male subjects during static contractions with shoulders 90 degrees abducted until endurance. The entropy (degree of uniformity) and center of gravity of the EMG root mean square map were computed to assess spatial inhomogeneity in muscle activation and changes over time in EMG amplitude spatial distribution. At the endurance time, entropy decreased (mean+/-SD, percent change 2.0+/-1.6%; P<0.0001) and the center of gravity moved in the cranial direction (shift 11.2+/-6.1mm; P<0.0001) with respect to the beginning of the contraction. The shift in the center of gravity was positively correlated with endurance time (R(2)=0.46, P<0.05), thus subjects with larger shift in the activity map showed longer endurance time. The percent variation in average (over the grid) root mean square was positively correlated with the shift in the center of gravity (R(2)=0.51, P<0.05). Moreover, the shift in the center of gravity was negatively correlated to both initial and final (at the endurance) entropy (R(2)=0.54 and R(2)=0.56, respectively; P<0.01 in both cases), indicating that subjects with less uniform root mean square maps had larger shift of the center of gravity over time. The spatial changes in root mean square EMG were likely due to spatially-dependent changes in motor unit activation during the sustained contraction. It was concluded that the changes in spatial muscle activity distribution play a role in the ability to maintain a static contraction.

Napping during night shift: practices, preferences, and perceptions of critical care and emergency department nurses.

PubMed

Fallis, Wendy M; McMillan, Diana E; Edwards, Marie P

2011-04-01

Nurses working night shifts are at risk for sleep deprivation, which threatens patient and nurse safety. Little nursing research has addressed napping, an effective strategy to improve performance, reduce fatigue, and increase vigilance. To explore nurses' perceptions, experiences, barriers, and safety issues related to napping/not napping during night shift. A convenience sample of critical care nurses working night shift were interviewed to explore demographics, work schedule and environment, and napping/ not napping experiences, perceptions, and barriers. Transcripts were constantly compared, and categories and themes were identified. Participants were 13 critical care nurses with an average of 17 years' experience. Ten nurses napped regularly; 2 avoided napping because of sleep inertia. The need for and benefits of napping or not during night shift break were linked to patient and nurse safety. Ability to nap was affected by the demands of patient care and safety, staffing needs, and organizational and environmental factors. Nurses identified personal health, safety, and patient care issues supporting the need for a restorative nap during night shift. Barriers to napping exist within the organization/work environment.

Pressure dependence of side chain 13C chemical shifts in model peptides Ac-Gly-Gly-Xxx-Ala-NH2.

PubMed

Beck Erlach, Markus; Koehler, Joerg; Crusca, Edson; Munte, Claudia E; Kainosho, Masatsune; Kremer, Werner; Kalbitzer, Hans Robert

2017-10-01

For evaluating the pressure responses of folded as well as intrinsically unfolded proteins detectable by NMR spectroscopy the availability of data from well-defined model systems is indispensable. In this work we report the pressure dependence of 13 C chemical shifts of the side chain atoms in the protected tetrapeptides Ac-Gly-Gly-Xxx-Ala-NH 2 (Xxx, one of the 20 canonical amino acids). Contrary to expectation the chemical shifts of a number of nuclei have a nonlinear dependence on pressure in the range from 0.1 to 200 MPa. The size of the polynomial pressure coefficients B 1 and B 2 is dependent on the type of atom and amino acid studied. For H N , N and C α the first order pressure coefficient B 1 is also correlated to the chemical shift at atmospheric pressure. The first and second order pressure coefficients of a given type of carbon atom show significant linear correlations suggesting that the NMR observable pressure effects in the different amino acids have at least partly the same physical cause. In line with this observation the magnitude of the second order coefficients of nuclei being direct neighbors in the chemical structure also are weakly correlated. The downfield shifts of the methyl resonances suggest that gauche conformers of the side chains are not preferred with pressure. The valine and leucine methyl groups in the model peptides were assigned using stereospecifically 13 C enriched amino acids with the pro-R carbons downfield shifted relative to the pro-S carbons.

Scanning-tunneling microscope imaging of single-electron solitons in a material with incommensurate charge-density waves.

PubMed

Brazovskii, Serguei; Brun, Christophe; Wang, Zhao-Zhong; Monceau, Pierre

2012-03-02

We report on scanning-tunneling microscopy experiments in a charge-density wave (CDW) system allowing visually capturing and studying in detail the individual solitons corresponding to the self-trapping of just one electron. This "Amplitude Soliton" is marked by vanishing of the CDW amplitude and by the π shift of its phase. It might be the realization of the spinon--the long-sought particle (along with the holon) in the study of science of strongly correlated electronic systems. As a distinct feature we also observe one-dimensional Friedel oscillations superimposed on the CDW which develop independently of solitons.

Attention and Gaze Control in Picture Naming, Word Reading, and Word Categorizing

ERIC Educational Resources Information Center

Roelofs, Ardi

2007-01-01

The trigger for shifting gaze between stimuli requiring vocal and manual responses was examined. Participants were presented with picture-word stimuli and left- or right-pointing arrows. They vocally named the picture (Experiment 1), read the word (Experiment 2), or categorized the word (Experiment 3) and shifted their gaze to the arrow to…

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

Baeßler, S.; Nesvizhevsky, V. V.; Pignol, G.

Quantum states of ultracold neutrons in a gravitational field are characterized through gravitational resonance spectroscopy. This paper discusses systematic effects that appear in the spectroscopic measurements. The discussed frequency shifts-which we call the Stern-Gerlach shift, interference shift, and spectator-state shift-appear in conceivable measurement schemes and have general importance. Lastly, these shifts have to be taken into account in precision experiments.

Identification of atmospheric structure by coherent microwave sounding

NASA Technical Reports Server (NTRS)

Birkemeier, W. P.

1969-01-01

Two atmospheric probing experiments involving beyond-the-horizon propagation of microwave signals are reported. In the first experiment, Doppler-shift caused by the cross path wind is measured by a phase lock receiver with the common volume displaced in azimuth from the great circle. Variations in the measured Doppler shift values are explained in terms of variations in atmospheric structure. The second experiment makes use of the pseudorandom sounding signal used in a RAKE communication system. Both multipath delay and Doppler shift are provided by the receiver, permitting the cross section of the atmospheric layer structure to be deduced.

Measurement of Critical Contact Angle in a Microgravity Space Experiment

NASA Technical Reports Server (NTRS)

Concus, P.; Finn, R.; Weislogel, M.

1998-01-01

Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

Measurement of Critical Contact Angle in a Microgravity Space Experiment

NASA Technical Reports Server (NTRS)

Concus, P.; Finn, R.; Weislogel, M.

1998-01-01

Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USMT,2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

Recovered vs. not-recovered from post-stroke aphasia: The contributions from the dominant and non-dominant hemispheres

PubMed Central

Szaflarski, Jerzy P.; Allendorfer, Jane B.; Banks, Christi; Vannest, Jennifer; Holland, Scott K.

2013-01-01

Purpose Several adult studies have documented the importance of the peri-stroke areas to aphasia recovery. But, studies examining the differences in patterns of cortical participation in language comprehension in patients who have (LMCA-R) or have not recovered (LMCA-NR) from left middle cerebral artery infarction have not been performed up to date. Methods In this study, we compare cortical correlates of language comprehension using fMRI and semantic decision/tone decision task in 9 LMCA-R and 18 LMCA-NR patients matched at the time of stroke for age and handedness. We examine the cortical correlates of language performance by correlating intra- and extra-scanner measures of linguistic performance with fMRI activation and stroke volumes. Results Our analyses show that LMCA-R at least 1 year after stroke show a return to typical fMRI language activation patterns and that there is a compensatory reorganization of language function in LMCA-NR patients with shifts to the right hemispheric brain regions. Further, with increasing strength of the left-hemispheric fMRI signal shift there are associated improvements in performance as tested with standardized linguistic measures. A negative correlation between the size of the stroke and performance on some of the linguistic tests is also observed. Conclusions This right-hemispheric shift as a mechanism of post-stroke recovery in adults appears to be an ineffective mode of language function recovery with increasing right-hemispheric shift associated with lower language performance. Thus, normalization of the post-stroke language activation patterns is needed for better language performance while shifts of the activation patterns to the non-dominant (right) hemisphere and/or large stroke size are associated with decreased linguistic abilities after stroke. PMID:23482065

De-educate to re-educate: aging and low back pain.

PubMed

Louw, Adriaan; Zimney, Kory; Johnson, Eldon A; Kraemer, Chris; Fesler, Justin; Burcham, Tyler

2017-12-01

Patients' beliefs about their condition have been shown to play a significant role in their pain experience and response to treatment, especially when a patient sees their tissue health as vulnerable or aged. Educational can alter these beliefs. Prior to new information, patients often have to be de-educated regarding common misbeliefs to undergo re-education. To determine if a brief de-education session regarding aging and low back pain (LBP) can shift pain ratings, fear-avoidance beliefs, beliefs regarding aging and LBP, and limited active trunk flexion. Fifty adults ranging from 50 to 93 years of age (SD = 10.73) with a 15.1 years of LBP were education on the poor correlation between aging and LBP. Prior to and immediately after the education pain ratings for LBP and leg pain (numeric pain rating scale-NPRS), fear-avoidance (fear avoidance beliefs questionnaire-FABQ), beliefs regarding aging and LBP (Likert scale) and active trunk flexion were measured. Significant changes were found in positive shifts with LBP (p = 0.002), leg pain (p = 0.042), FABQ-physical activity subscale (p = 0.004) and active trunk forward flexion (p < 0.001). The results show that education aimed at altering beliefs regarding LBP and aging result in a positive shift in pain, fear avoidance related to physical activity and active trunk flexion. Prior to providing patients with new healthcare information, de-educating them regarding poor beliefs may be helpful in shifting them towards new, healthier paradigms associated with their condition.

Determination of size and sign of hetero-nuclear coupling constants from 2D 19F-13C correlation spectra.

PubMed

Ampt, Kirsten A M; Aspers, Ruud L E G; Dvortsak, Peter; van der Werf, Ramon M; Wijmenga, Sybren S; Jaeger, Martin

2012-02-01

Fluorinated organic compounds have become increasingly important within the polymer and the pharmaceutical industry as well as for clinical applications. For the structural elucidation of such compounds, NMR experiments with fluorine detection are of great value due to the favorable NMR properties of the fluorine nucleus. For the investigation of three fluorinated compounds, triple resonance 2D HSQC and HMBC experiments were adopted to fluorine detection with carbon and/or proton decoupling to yield F-C, F-C{H}, F-C{C(acq)} and F-C{H,C(acq)} variants. Analysis of E.COSY type cross-peak patterns in the F-C correlation spectra led, apart from the chemical shift assignments, to determination of size and signs of the J(CH), J(CF), and J(HF) coupling constants. In addition, the fully coupled F-C HMQC spectrum of steroid 1 was interpreted in terms of E.COSY type patterns. This example shows how coupling constants due to different nuclei can be determined together with their relative signs from a single spectrum. The analysis of cross-peak patterns, as presented here, not only provides relatively straightforward routes to the determination of size and sign of hetero-nuclear J-couplings in fluorinated compounds, it also provides new and easy ways for the determination of residual dipolar couplings and thus for structure elucidation. The examples and results presented in this study may contribute to a better interpretation and understanding of various F-C correlation experiments and thereby stimulate their utilization. Copyright © 2011 Elsevier Inc. All rights reserved.

Complex conductivity response to microbial growth and biofilm formation on phenanthrene spiked medium

NASA Astrophysics Data System (ADS)

Albrecht, Remy; Gourry, Jean Christophe; Simonnot, Marie-Odile; Leyval, Corinne

2011-11-01

Several laboratory studies have recently demonstrated the utility of geophysical methods for the investigation of microbial-induced changes over contaminated sites. However, it remains difficult to distinguish the effects due to the new physical properties imparted by microbial processes, to bacterial growth, or to the development of bacterial biofilm. We chose to study the influence of biofilm formation on geophysical response using complex conductivity measurements (0.1-1000 Hz) in phenanthrene-contaminated media. Biotic assays were conducted with two phenanthrene (PHE) degrading bacterial strains: Burkholderia sp (NAH1), which produced biofilm and Stenophomonas maltophilia (MATE10), which did not, and an abiotic control. Results showed that bacterial densities for NAH1 and MATE10 strains continuously increased at the same rate during the experiment. However, the complex conductivity signature showed noticeable differences between the two bacteria, with a phase shift of 50 mrad at 4 Hz for NAH1, which produced biofilm. Biofilm volume was quantified by Scanning Confocal Laser Microscopy (SCLM). Significant correlations were established between phase shift decrease and biofilm volume for NAH1 assays. Results suggest that complex conductivity measurements, specifically phase shift, can be a useful indicator of biofilm formation inside the overall signal of microbial activity on contaminated sites.

clubber: removing the bioinformatics bottleneck in big data analyses.

PubMed

Miller, Maximilian; Zhu, Chengsheng; Bromberg, Yana

2017-06-13

With the advent of modern day high-throughput technologies, the bottleneck in biological discovery has shifted from the cost of doing experiments to that of analyzing results. clubber is our automated cluster-load balancing system developed for optimizing these "big data" analyses. Its plug-and-play framework encourages re-use of existing solutions for bioinformatics problems. clubber's goals are to reduce computation times and to facilitate use of cluster computing. The first goal is achieved by automating the balance of parallel submissions across available high performance computing (HPC) resources. Notably, the latter can be added on demand, including cloud-based resources, and/or featuring heterogeneous environments. The second goal of making HPCs user-friendly is facilitated by an interactive web interface and a RESTful API, allowing for job monitoring and result retrieval. We used clubber to speed up our pipeline for annotating molecular functionality of metagenomes. Here, we analyzed the Deepwater Horizon oil-spill study data to quantitatively show that the beach sands have not yet entirely recovered. Further, our analysis of the CAMI-challenge data revealed that microbiome taxonomic shifts do not necessarily correlate with functional shifts. These examples (21 metagenomes processed in 172 min) clearly illustrate the importance of clubber in the everyday computational biology environment.

clubber: removing the bioinformatics bottleneck in big data analyses

PubMed Central

Miller, Maximilian; Zhu, Chengsheng; Bromberg, Yana

2018-01-01

With the advent of modern day high-throughput technologies, the bottleneck in biological discovery has shifted from the cost of doing experiments to that of analyzing results. clubber is our automated cluster-load balancing system developed for optimizing these “big data” analyses. Its plug-and-play framework encourages re-use of existing solutions for bioinformatics problems. clubber’s goals are to reduce computation times and to facilitate use of cluster computing. The first goal is achieved by automating the balance of parallel submissions across available high performance computing (HPC) resources. Notably, the latter can be added on demand, including cloud-based resources, and/or featuring heterogeneous environments. The second goal of making HPCs user-friendly is facilitated by an interactive web interface and a RESTful API, allowing for job monitoring and result retrieval. We used clubber to speed up our pipeline for annotating molecular functionality of metagenomes. Here, we analyzed the Deepwater Horizon oil-spill study data to quantitatively show that the beach sands have not yet entirely recovered. Further, our analysis of the CAMI-challenge data revealed that microbiome taxonomic shifts do not necessarily correlate with functional shifts. These examples (21 metagenomes processed in 172 min) clearly illustrate the importance of clubber in the everyday computational biology environment. PMID:28609295

Multiconfiguration calculations of electronic isotope shift factors in Al i

NASA Astrophysics Data System (ADS)

Filippin, Livio; Beerwerth, Randolf; Ekman, Jörgen; Fritzsche, Stephan; Godefroid, Michel; Jönsson, Per

2016-12-01

The present work reports results from systematic multiconfiguration Dirac-Hartree-Fock calculations of electronic isotope shift factors for a set of transitions between low-lying levels of neutral aluminium. These electronic quantities together with observed isotope shifts between different pairs of isotopes provide the changes in mean-square charge radii of the atomic nuclei. Two computational approaches are adopted for the estimation of the mass- and field-shift factors. Within these approaches, different models for electron correlation are explored in a systematic way to determine a reliable computational strategy and to estimate theoretical error bars of the isotope shift factors.

Servomechanism for Doppler shift compensation in optical correlator for synthetic aperture radar

NASA Technical Reports Server (NTRS)

Constaninides, N. J.; Bicknell, T. J. (Inventor)

1980-01-01

A method and apparatus for correcting Doppler shifts in synthetic aperture radar data is described. An optical correlator for synthetic aperture radar data has a means for directing a laser beam at a signal film having radar return pulse intensity information recorded on it. A resultant laser beam passes through a range telescope, an azimuth telescope, and a Fourier transform filter located between the range and azimuth telescopes, and forms an image for recording on an image film. A compensation means for Doppler shift in the radar return pulse intensity information includes a beam splitter for reflecting the modulated laser beam, after having passed through the Fourier transform filter, to a detection screen having two photodiodes mounted on it.

Analysis of digital communication signals and extraction of parameters

NASA Astrophysics Data System (ADS)

Al-Jowder, Anwar

1994-12-01

The signal classification performance of four types of electronics support measure (ESM) communications detection systems is compared from the standpoint of the unintended receiver (interceptor). Typical digital communication signals considered include binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), frequency shift keying (FSK), and on-off keying (OOK). The analysis emphasizes the use of available signal processing software. Detection methods compared include broadband energy detection, FFT-based narrowband energy detection, and two correlation methods which employ the fast Fourier transform (FFT). The correlation methods utilize modified time-frequency distributions, where one of these is based on the Wigner-Ville distribution (WVD). Gaussian white noise is added to the signal to simulate various signal-to-noise ratios (SNR's).

From Nothing to Something II: Nonlinear Systems via Consistent Correlated Bang

NASA Astrophysics Data System (ADS)

Lou, Sen-Yue

2017-06-01

Chinese ancient sage Laozi said everything comes from \\emph{\\bf \\em "nothing"}. \\rm In the first letter (Chin. Phys. Lett. 30 (2013) 080202), infinitely many discrete integrable systems have been obtained from "nothing" via simple principles (Dao). In this second letter, a new idea, the consistent correlated bang, is introduced to obtain nonlinear dynamic systems including some integrable ones such as the continuous nonlinear Schr\\"odinger equation (NLS), the (potential) Korteweg de Vries (KdV) equation, the (potential) Kadomtsev-Petviashvili (KP) equation and the sine-Gordon (sG) equation. These nonlinear systems are derived from nothing via suitable "Dao", the shifted parity, the charge conjugate, the delayed time reversal, the shifted exchange, the shifted-parity-rotation and so on.

The correlation structure of several popular pseudorandom number generators

NASA Technical Reports Server (NTRS)

Neuman, F.; Merrick, R.; Martin, C. F.

1973-01-01

One of the desirable properties of a pseudorandom number generator is that the sequence of numbers it generates should have very low autocorrelation for all shifts except for zero shift and those that are multiples of its cycle length. Due to the simple methods of constructing random numbers, the ideal is often not quite fulfilled. A simple method of examining any random generator for previously unsuspected regularities is discussed. Once they are discovered it is often easy to derive the mathematical relationships, which describe the mathematical relationships, which describe the regular behavior. As examples, it is shown that high correlation exists in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle lengths.

Can you see me? Experiences of nurses working night shift in Australian regional hospitals: a qualitative case study.

PubMed

Powell, Idona

2013-10-01

To report a study that explored the experiences of night-shift nurses, focusing on employee interrelationships and work satisfaction. Night-shift nurses are a critical component in hospital care making it essential to understand the experiences that give meaning to their work and understand how these nurses and the organization can benefit from their contribution to hospital care. A literature review revealed minimal research in this area. Qualitative case study. A qualitative case study using semi-structured interviews and self-completed diaries was conducted in 2010 in regional public hospitals in Australia. Participants were 14 nurses working nights half or more of their shifts in medical or surgical wards. Thematic analysis identified four major areas of concern: work relationships, work environment, work practices and lifestyle impact. Notably, work relationships were most meaningful for nurses on the same shift; night-shift nurses experienced working conditions inferior to their daytime counterparts including a perception of minimal leadership. Despite limited education opportunities, night shift provided opportunity for professional growth for some nurses with a slippage in skills for others; night shift provided flexibility for family and social activities, yet impeded these same activities, primarily due to pervasive fatigue. Night-shift nurses considered their role critical, yet believed that they were poorly regarded. The strong interpersonal relationships developed between night-shift workers need to be capitalized on whilst developing a more effective leadership model, improved work environment, more equitable professional development, and genuine recognition of the critical role of night nurses. © 2013 Blackwell Publishing Ltd.

Electrostatics determine vibrational frequency shifts in hydrogen bonded complexes.

PubMed

Dey, Arghya; Mondal, Sohidul Islam; Sen, Saumik; Ghosh, Debashree; Patwari, G Naresh

2014-12-14

The red-shifts in the acetylenic C-H stretching vibration of C-H∙∙∙X (X = O, N) hydrogen-bonded complexes increase with an increase in the basicity of the Lewis base. Analysis of various components of stabilization energy suggests that the observed red-shifts are correlated with the electrostatic component of the stabilization energy, while the dispersion modulates the stabilization energy.

Preparation of a Cobalt(II) Cage: An Undergraduate Laboratory Experiment That Produces a ParaSHIFT Agent for Magnetic Resonance Spectroscopy

ERIC Educational Resources Information Center

Burns, Patrick J.; Tsitovich, Pavel B.; Morrow, Janet R.

2016-01-01

Laboratory experiments that demonstrate the effect of paramagnetic complexes on chemical shifts and relaxation times of protons are a useful way to introduce magnetic resonance spectroscopy (MRS) probes or magnetic resonance imaging (MRI) contrast agents. In this undergraduate inorganic chemistry experiment, a paramagnetic Co(II) cage complex is…

SeaQuest/E906 Shift Alarm System

NASA Astrophysics Data System (ADS)

Kitts, Noah

2014-09-01

SeaQuest, Fermilab E906, is a fixed target experiment that measures the Drell-Yan cross-section ratio of proton-proton to proton-deuterium collisions in order to extract the sea anti-quark structure of the proton. SeaQuest will extend the measurements made by E866/NuSea with greater precision at higher Bjorken-x. The continuously running experiment is always being monitored. Those on shift must keep track of all of the detector readouts in order to make sure the experiment is running correctly. As an experiment that is still in its early stages of running, an alarm system for people on shift is being created to provide warnings, such as a plot showing a detector's performance is sufficiently different to need attention. This plan involves python scripts that track live data. When the data shows a problem within the experiment, a corresponding alarm ID is sent to the MySQL database which then sets off an alarm. These alarms, which will alert the person on shift through both an audible and visual response, are important for ensuring that issues do not go unnoticed, and to help make sure the experiment is recording good data.

Augmented potential, energy densities, and virial relations in the weak- and strong-interaction limits of DFT

NASA Astrophysics Data System (ADS)

Vuckovic, Stefan; Levy, Mel; Gori-Giorgi, Paola

2017-12-01

The augmented potential introduced by Levy and Zahariev [Phys. Rev. Lett. 113, 113002 (2014)] is shifted with respect to the standard exchange-correlation potential of the Kohn-Sham density functional theory by a density-dependent constant that makes the total energy become equal to the sum of the occupied orbital energies. In this work, we analyze several features of this approach, focusing on the limit of infinite coupling strength and studying the shift and the corresponding energy density at different correlation regimes. We present and discuss coordinate scaling properties of the augmented potential, study its connection to the response potential, and use the shift to analyze the classical jellium and uniform gas models. We also study other definitions of the energy densities in relation to the functional construction by local interpolations along the adiabatic connection. Our findings indicate that the energy density that is defined in terms of the electrostatic potential of the exchange-correlation hole is particularly well suited for this purpose.

Body position-dependent shift in odor percept present only for perithreshold odors.

PubMed

Lundström, Johan N; Boyle, Julie A; Jones-Gotman, Marilyn

2008-01-01

We recently demonstrated that a supine position causes a decrease in olfactory sensitivity compared with an upright position. We pursued that initial finding in 3 separate experiments in which we explored the extent of, and mechanism underlying, this phenomenon. In Experiment 1, we replicated the decrease in olfactory sensitivity when in a supine compared with an upright position. In Experiment 2, we measured body position-dependent shifts in physiological variables and sniff measures while smelling suprathreshold odorants and performing a perithreshold odor intensity discrimination task. Olfactory performances were reduced while supine. However, no relationships between the shift in olfactory performances and either the physiological variables or sniff measures were found. In Experiment 3, we determined that there were no position-dependent shifts in ability to discriminate or identify suprathreshold odors or rate them for pleasantness, intensity, or familiarity. However, a drop in scores was observed, and performance was slowed, on a cognitive skill while supine. These results demonstrate a body position-dependent shift in olfactory sensitivity only for perithreshold odors that appears to be mediated by cognitive rather than physiological factors. Implications for olfactory imaging studies are discussed.

Nurses aged over 50 years and their experiences of shift work.

PubMed

Clendon, Jill; Walker, Leonie

2013-10-01

The Late Career Nurse project examined views and characteristics of nurses working in New Zealand who were born before 1960. This paper focuses on the experiences of such nurses who undertake shift work. The mean age of registered nurses in New Zealand has been rising steadily, and 40% are now aged 50 years or over. While there is substantial literature on the phenomenon and consequences of the ageing nursing workforce, little is known of the particular experiences of nurses aged over 50 years who work shifts. An anonymous online survey was emailed to eligible nurse New Zealand Nurses Organisation members aged over 50 years in February 2012. Quantitative and qualitative analyses of the 3273 responses received were undertaken. Over 45% of respondents worked shifts or flexible hours. While shift work suited many, others noted deleterious effects on family and social relationships, physical and mental health (notably sleep patterns and fatigue), and decreasing tolerance for shift work as they age. Poor scheduling practices were particularly detrimental. Worldwide, workforce ageing means strategies are required to retain older nurses in the workforce. Improved scheduling practices including increasing access to flexible and part time work hours, and development of resources on coping with shift work are recommended. © 2013 John Wiley & Sons Ltd.

A Simple Ultrasonic Experiment Using a Phase Shift Detection Technique.

ERIC Educational Resources Information Center

Yunus, W. Mahmood Mat; Ahmad, Maulana

1996-01-01

Describes a simple ultrasonic experiment that can be used to measure the purity of liquid samples by detecting variations in the velocity of sound. Uses a phase shift detection technique that incorporates the use of logic gates and a piezoelectric transducer. (JRH)

Handling the influence of chemical shift in amplitude-modulated heteronuclear dipolar recoupling solid-state NMR

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

Basse, Kristoffer; Shankar, Ravi; Bjerring, Morten

We present a theoretical analysis of the influence of chemical shifts on amplitude-modulated heteronuclear dipolar recoupling experiments in solid-state NMR spectroscopy. The method is demonstrated using the Rotor Echo Short Pulse IRrAdiaTION mediated Cross-Polarization ({sup RESPIRATION}CP) experiment as an example. By going into the pulse sequence rf interaction frame and employing a quintuple-mode operator-based Floquet approach, we describe how chemical shift offset and anisotropic chemical shift affect the efficiency of heteronuclear polarization transfer. In this description, it becomes transparent that the main attribute leading to non-ideal performance is a fictitious field along the rf field axis, which is generated frommore » second-order cross terms arising mainly between chemical shift tensors and themselves. This insight is useful for the development of improved recoupling experiments. We discuss the validity of this approach and present quaternion calculations to determine the effective resonance conditions in a combined rf field and chemical shift offset interaction frame transformation. Based on this, we derive a broad-banded version of the {sup RESPIRATION}CP experiment. The new sequence is experimentally verified using SNNFGAILSS amyloid fibrils where simultaneous {sup 15}N → {sup 13}CO and {sup 15}N → {sup 13}C{sub α} coherence transfer is demonstrated on high-field NMR instrumentation, requiring great offset stability.« less

Dopamine and executive function: Increased spontaneous eye blink rates correlate with better set-shifting and inhibition, but poorer updating.

PubMed

Zhang, Ting; Mou, Di; Wang, Cuicui; Tan, Fengping; Jiang, Yan; Lijun, Zheng; Li, Hong

2015-06-01

The central dopamine system (DA) has a significant role in the executive function (EF). The spontaneous eye blink rate (EBR) is an effective clinical and non-invasive measure, which is strongly related to the activity of the central dopaminergic system. Previous studies show significant relationships between the two main dimensions of EF (i.e., shifting and inhibition) and the central DA system as measured by EBR. However, most of these studies involve only one EF task for shifting or inhibition; whether or not these relationships are replicated by other EF tasks remains unclear. Besides, the relationship between EBR and another important EF dimension-updating-also remains unknown. The present study examined the correlation between EBR and several EF tasks that captured all the three EF dimensions: shifting, inhibition, and updating. A total of 61 healthy participants were subjected to EBR testing and EF tasks. Results showed that EBR had a different relationship with each of the three tested EF dimensions. An increase in EBR levels was related to an increase in accuracy in shifting and inhibition tasks, a decrease in shifting and inhibition cost, and a decrease in accuracy in updating tasks. These results imply that the role of the central DA system in shifting and inhibition differs from its role in updating. Copyright © 2015 Elsevier B.V. All rights reserved.

Realized niche shift during a global biological invasion

PubMed Central

Tingley, Reid; Vallinoto, Marcelo; Sequeira, Fernando; Kearney, Michael R.

2014-01-01

Accurate forecasts of biological invasions are crucial for managing invasion risk but are hampered by niche shifts resulting from evolved environmental tolerances (fundamental niche shifts) or the presence of novel biotic and abiotic conditions in the invaded range (realized niche shifts). Distinguishing between these kinds of niche shifts is impossible with traditional, correlative approaches to invasion forecasts, which exclusively consider the realized niche. Here we overcome this challenge by combining a physiologically mechanistic model of the fundamental niche with correlative models based on the realized niche to study the global invasion of the cane toad Rhinella marina. We find strong evidence that the success of R. marina in Australia reflects a shift in the species’ realized niche, as opposed to evolutionary shifts in range-limiting traits. Our results demonstrate that R. marina does not fill its fundamental niche in its native South American range and that areas of niche unfilling coincide with the presence of a closely related species with which R. marina hybridizes. Conversely, in Australia, where coevolved taxa are absent, R. marina largely fills its fundamental niche in areas behind the invasion front. The general approach taken here of contrasting fundamental and realized niche models provides key insights into the role of biotic interactions in shaping range limits and can inform effective management strategies not only for invasive species but also for assisted colonization under climate change. PMID:24982155

Clinical investigation of set-shifting subtypes in anorexia nervosa.

PubMed

Abbate-Daga, Giovanni; Buzzichelli, Sara; Marzola, Enrica; Amianto, Federico; Fassino, Secondo

2014-11-30

While evidence continues to accumulate on the relevance of cognitive inflexibility in anorexia nervosa (AN), its clinical correlates remain unclear. We aimed at examining the relationship between set-shifting and clinical variables (i.e., eating psychopathology, depression, and personality) in AN. Ninety-four individuals affected by AN and 59 healthy controls (HC) were recruited. All participants were assessed using: Eating Disorders Inventory-2 (EDI-2), Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI), and Wisconsin Card Sorting Test (WCST). The AN group scored worse than HCs on set-shifting. According to their neuropsychological performances, AN patients were split into two groups corresponding to poor (N=30) and intact (N=64) set-shifting subtypes. Interoceptive awareness, impulse regulation, and maturity fears on the EDI-2 and depression on the BDI differed across all groups (HC, intact, and poor set-shifting subtype). Self-directedness on the TCI differed significantly among all groups. Cooperativeness and reward dependence differed instead only between HC and AN poor set-shifting subtype. After controlling for depression, only interoceptive awareness remained significant with reward dependence showing a trend towards statistical significance. These findings suggest that multiple clinical variables may be correlated with set-shifting performances in AN. The factors contributing to impaired cognitive inflexibility could be more complex than heretofore generally considered. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

On the relation between activity-related frequency shifts and the sunspot distribution over the solar cycle 23

NASA Astrophysics Data System (ADS)

Santos, Ângela R. G.; Cunha, Margarida S.; Avelino, Pedro P.; Chaplin, William J.; Campante, Tiago L.

2017-10-01

The activity-related variations in the solar acoustic frequencies have been known for 30 years. However, the importance of the different contributions is still not well established. With this in mind, we developed an empirical model to estimate the spot-induced frequency shifts, which takes into account the sunspot properties, such as area and latitude. The comparison between the model frequency shifts obtained from the daily sunspot records and those observed suggests that the contribution from a stochastic component to the total frequency shifts is about 30%. The remaining 70% is related to a global, long-term variation. We also propose a new observable to investigate the short-and mid-term variations of the frequency shifts, which is insensitive to the long-term variations contained in the data. On the shortest time scales the variations in the frequency shifts are strongly correlated with the variations in the total area covered by sunspots. However, a significant loss of correlation is still found, which cannot be fully explained by ignoring the invisible side of the Sun when accounting for the total sunspot area. We also verify that the times when the frequency shifts and the sunspot areas do not vary in a similar way tend to coincide with the times of the maximum amplitude of the quasi-biennial variations found in the seismic data.

Mass-independent isotope fractionation of Mo, Ru, Cd, and Te

NASA Astrophysics Data System (ADS)

Fujii, T.; Moynier, F.; Albarède, F.

2006-12-01

The variation of the mean charge distribution in the nucleus with the neutron number of different isotopes induces a tenuous shift of the nuclear field. The mass fractionation induced during phase changes is irregular, notably with 'staggering' between odd and even masses, and becomes increasingly non-linear for neutron-rich isotopes. A strong correlation is observed between the deviation of the isotopic effects from the linear dependence with mass and the corresponding nuclear charge radii. We first demonstrated on a number of elements the existence of such mass-independent isotope fractionation in laboratory experiments of solvent extraction with a macrocyclic compound. The isotope ratios were analyzed by multiple-collector inductively coupled plasma mass spectrometry with a typical precision of <100 ppm. The isotopes of odd and even atomic masses are enriched in the solvent to an extent that closely follows the variation of their nuclear charge radii. The present results fit Bigeleisen's (1996) model, which is the standard mass-dependent theory modified to include a correction term named the nuclear field shift effect. For heavy elements like uranium, the mass-independent effect is important enough to dominate the mass-dependent effect. We subsequently set out to compare the predictions of Bigeleisen's theory with the isotopic anomalies found in meteorites. Some of these anomalies are clearly inconsistent with nucleosynthetic effects (either s- or r-processes). Isotopic variations of Mo and Ru in meteorites, especially in Allende (CV3), show a clear indication of nucleosynthetic components. However, the mass-independent anomaly of Ru observed in Murchison (CM2) is a remarkable exception which cannot be explained by the nucleosynthetic model, but fits the nuclear field shift theory extremely well. The abundances of the even atomic mass Te isotopes in the leachates of carbonaceous chondrites, Allende, Murchison, and Orgueil, fit a mass-dependent law well, but the odd atomic mass isotope ^{125}Te clearly deviates from this correlation. The nuclear field shift theory shows that there is no effect on ^{130}Te but that the ^{125}Te anomaly is real. Carbonaceous chondrites do not reveal significant isotope fractionation of Cd isotopes, but a nuclear field shift effect is clearly present in type-3 (unequilibrated) ordinary chondrites. The nuclear field shift effect is temperature dependent and is probably more frequent in nature than commonly thought. It remains, together with nucleosynthetric anomalies, perfectly visible through the normalization of isotopic ratios to a reference value. In meteorites, this effect may originate both during condensation/evaporation processes in the nebular gas and during the metamorphism of the meteorite parent bodies.

Dependence of the correlated-momentum patterns in double ionization on the carrier-envelope phase and intensity of a few-cycle laser pulse

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

Xin, G. G.; Ye, D. F.; Graduate School, China Academy of Engineering Physics, Beijing 100088

2010-12-15

In the present paper, we investigate the correlated electron emission of atoms irradiated by a few-cycle laser pulse, with emphasis on the correlated longitudinal momentum spectra. We find that the spectra show clear v-shaped structures, in analogy to what was observed recently in long-pulse experiments. Moreover, the patterns of the spectra depend sensitively on the carrier-envelope phase as well as the laser intensity. The v-shaped structure is more pronounced at lower and higher intensities and becomes obscure at medium intensity. At a lower intensity, upon change of the phase from 0 to {pi}/2, the v-shaped structure shifts from the firstmore » quadrant to the third quadrant and the ratios between the double ionization yields in the first and third quadrants are found to increase by a few orders of magnitude. The semiclassical rescattering model is exploited in the preceding calculations and the underlying mechanisms are uncovered by analyzing the subcycle dynamics of classical trajectories.« less

Distributioin, orientation and scales of the field-aligned currents measured by Swarm

NASA Astrophysics Data System (ADS)

Yang, J.; Dunlop, M. W.

2016-12-01

We have statistically studied the R1, R2 and net field aligned currents using the FAC data of the Swarm satellites. We also have investigated the statistical, dual-spacecraft correlations of field-aligned current signatures between two Swarm spacecraft (A and C). For the first time we have inferred the orientations of the current sheets of FACs directly, using the maximum correlations, obtained from sliding data segments, which show clear trends in magnetic local time (MLT). To compare with this we also check the MVAB method. To explore the scale and variability of the current sheet supposition, we investigate the MLT dependence of the maximum correlations in different time shift or longitude shift bins.

Spontaneous cortical DC-potential shifts: modulation stereotypy; relationships to higher EEG-frequencies.

PubMed

Etlinger, S C; Guttmann, G; Bauer, H

1986-07-01

A description of scalp-recorded, spontaneous, cerebral DC-potential shifts is given independent of other variables (shift stereotypy), in relationship to higher frequencies (theta, alpha 1, alpha 2: 4-13 Hz) and as analyzed pairwise across the median sagittal line (Fz, Cz, Pz) separately according to frequency and condition (relaxation and moderate mental load). Spontaneous DC-shifts are shown to behave unpredictably. Whether measured jointly (up to triads) or as dyad and triad context entropy, the frontal DC-shifts are calculated as being random, whereby their definition as such within the context of the Principle Component Analysis is supported by the analysis of longitudinal registrations. Cross-correlation analysis of the cerebral slow potential's relationship to each of the higher frequencies (theta, alpha 1, alpha 2) reveals it to be highly independent, the highest correlation accounting for merely 11% of the common variance, the average being 9% (R congruent to 0.3). By matching the conjoint activity of the DC-potential between Fz-Cz, Cz-Pz, and Fz-Pz to that of theta, alpha 1, alpha 2 at the same paired sites, the DC-activity is shown to be operating at higher levels of synchronous activity than the higher frequencies, regardless of pairing and/or condition, although the general level of synchronous activity (DC, theta, alpha 1, alpha 2) is remarkably high along the median sagittal line, 75% of the correlation averages of all analysis-pairings being above 0.60.

ON AN ALLEGED TRUTH/FALSITY ASYMMETRY IN CONTEXT SHIFTING EXPERIMENTS

PubMed Central

Hansen, Nat

2012-01-01

Keith DeRose has argued that context shifting experiments should be designed in a specific way in order to accommodate what he calls a ‘truth/falsity asymmetry’. I explain and critique DeRose's reasons for proposing this modification to contextualist methodology, drawing on recent experimental studies of DeRose's bank cases as well as experimental findings about the verification of affirmative and negative statements. While DeRose's arguments for his particular modification to contextualist methodology fail, the lesson of his proposal is that there is good reason to pay close attention to several subtle aspects of the design of context shifting experiments. PMID:25821248

Connecting optical and X-ray tracers of galaxy cluster relaxation

NASA Astrophysics Data System (ADS)

Roberts, Ian D.; Parker, Laura C.; Hlavacek-Larrondo, Julie

2018-04-01

Substantial effort has been devoted in determining the ideal proxy for quantifying the morphology of the hot intracluster medium in clusters of galaxies. These proxies, based on X-ray emission, typically require expensive, high-quality X-ray observations making them difficult to apply to large surveys of groups and clusters. Here, we compare optical relaxation proxies with X-ray asymmetries and centroid shifts for a sample of Sloan Digital Sky Survey clusters with high-quality, archival X-ray data from Chandra and XMM-Newton. The three optical relaxation measures considered are the shape of the member-galaxy projected velocity distribution - measured by the Anderson-Darling (AD) statistic, the stellar mass gap between the most-massive and second-most-massive cluster galaxy, and the offset between the most-massive galaxy (MMG) position and the luminosity-weighted cluster centre. The AD statistic and stellar mass gap correlate significantly with X-ray relaxation proxies, with the AD statistic being the stronger correlator. Conversely, we find no evidence for a correlation between X-ray asymmetry or centroid shift and the MMG offset. High-mass clusters (Mhalo > 1014.5 M⊙) in this sample have X-ray asymmetries, centroid shifts, and Anderson-Darling statistics which are systematically larger than for low-mass systems. Finally, considering the dichotomy of Gaussian and non-Gaussian clusters (measured by the AD test), we show that the probability of being a non-Gaussian cluster correlates significantly with X-ray asymmetry but only shows a marginal correlation with centroid shift. These results confirm the shape of the radial velocity distribution as a useful proxy for cluster relaxation, which can then be applied to large redshift surveys lacking extensive X-ray coverage.

Poster — Thur Eve — 13: Inter-Fraction Target Movement in Image-Guided Radiation Therapy of Prostate Cancer

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

Cui, Congwu; Zeng, Grace G.; Department of Radiation Oncology, University of Toronto, Toronto, ON

2014-08-15

We investigated the setup variations over the treatment courses of 113 patients with intact prostate treated with 78Gy/39fx. Institutional standard bladder and bowel preparation and image guidance protocols were used in CT simulation and treatment. The RapidArc treatment plans were optimized in Varian Eclipse treatment planning system and delivered on Varian 2100X Clinacs equipped with On-Board Imager to localize the target before beam-on. The setup variations were calculated in terms of mean and standard deviation of couch shifts. No correlation was observed between the mean shift and standard deviation over the treatment course and patient age, initial prostate volume andmore » rectum size. The mean shifts in the first and last 5 fractions are highly correlated (P < 10{sup −10}) while the correlation of the standard deviations cannot be determined. The Mann-Kendall tests indicate trends of the mean daily Ant-Post and Sup-Inf shifts of the group. The target is inferior by ∼1mm to the planned position when the treatment starts and moves superiorly, approaching the planned position at 10th fraction, and then gradually moves back inferiorly by ∼1mm in the remain fractions. In the Ant-Post direction, the prostate gradually moves posteriorly during the treatment course from a mean shift of ∼2.5mm in the first fraction to ∼1mm in the last fraction. It may be related to a systematic rectum size change in the progress of treatment. The biased mean shifts in Ant-Post and Sup-Inf direction of most patients suggest systematically larger rectum and smaller bladder during the treatment than at CT simulation.« less

Investigation of the Frequency Shift of a SAD Circuit Loop and the Internal Micro-Cantilever in a Gas Sensor

PubMed Central

Guan, Liu; Zhao, Jiahao; Yu, Shijie; Li, Peng; You, Zheng

2010-01-01

Micro-cantilever sensors for mass detection using resonance frequency have attracted considerable attention over the last decade in the field of gas sensing. For such a sensing system, an oscillator circuit loop is conventionally used to actuate the micro-cantilever, and trace the frequency shifts. In this paper, gas experiments are introduced to investigate the mechanical resonance frequency shifts of the micro-cantilever within the circuit loop(mechanical resonance frequency, MRF) and resonating frequency shifts of the electric signal in the oscillator circuit (system working frequency, SWF). A silicon beam with a piezoelectric zinc oxide layer is employed in the experiment, and a Self-Actuating-Detecting (SAD) circuit loop is built to drive the micro-cantilever and to follow the frequency shifts. The differences between the two resonating frequencies and their shifts are discussed and analyzed, and a coefficient α related to the two frequency shifts is confirmed. PMID:22163588

The influence of context boundaries on memory for the sequential order of events.

PubMed

DuBrow, Sarah; Davachi, Lila

2013-11-01

Episodic memory allows people to reexperience the past by recovering the sequences of events that characterize those prior experiences. Although experience is continuous, people are able to selectively retrieve and reexperience more discrete episodes from their past, raising the possibility that some elements become tightly related to each other in memory, whereas others do not. The current series of experiments was designed to ask how shifts in context during an experience influence how people remember the past. Specifically, we asked how context shifts influence the ability to remember the relative order of past events, a hallmark of episodic memory. We found that memory for the order of events was enhanced within, rather than across, context shifts, or boundaries (Experiment 1). Next, we showed that this relative enhancement in order memory was eliminated when across-item associative processing was disrupted (Experiment 2), suggesting that context shifts have a selective effect on sequential binding. Finally, we provide evidence that the act of making order memory judgments involves the reactivation of representations that bridged the tested items (Experiment 3). Together, these data suggest that boundaries may serve to parse continuous experience into sequences of contextually related events and that this organization facilitates remembering the temporal order of events that share the same context. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Retrieval-Induced vs. Context-Induced Forgetting: Does Retrieval-Induced Forgetting Depend on Context Shifts?

PubMed Central

Soares, Julia S.; Polack, Cody W.; Miller, Ralph R.

2015-01-01

Retrieval-induced forgetting (RIF) is the observation that retrieval of target information causes forgetting of related non-target information. A number of accounts of this phenomenon have been proposed, including a context-shift based account (Jonker, Seli, & Macleod, 2013). This account proposes that RIF occurs due to the context shift from study to retrieval practice, provided there is little context shift between retrieval practice and test phases. We tested both claims put forth by this context account. In Experiment 1, we degraded the context shift between study and retrieval practice by implementing a generative study condition that was highly similar to retrieval practice. We observed no degradation of RIF for these generated exemplars relative to a conventional study control. In Experiment 2, we conceptually replicated the finding of RIF following generative study, and tested whether context differences between each of the three phases affected the size of RIF. Our findings were again contrary to the predictions of the context account. Conjointly, the two experiments refute arguments about the potential inadequacy of our context shifts that could be used to explain either result alone. Overall, our results are most consistent with an inhibitory account of RIF (e.g., Anderson, 2003). PMID:26389628

Registration uncertainties between 3D cone beam computed tomography and different reference CT datasets in lung stereotactic body radiation therapy.

PubMed

Oechsner, Markus; Chizzali, Barbara; Devecka, Michal; Combs, Stephanie Elisabeth; Wilkens, Jan Jakob; Duma, Marciana Nona

2016-10-26

The aim of this study was to analyze differences in couch shifts (setup errors) resulting from image registration of different CT datasets with free breathing cone beam CTs (FB-CBCT). As well automatic as manual image registrations were performed and registration results were correlated to tumor characteristics. FB-CBCT image registration was performed for 49 patients with lung lesions using slow planning CT (PCT), average intensity projection (AIP), maximum intensity projection (MIP) and mid-ventilation CTs (MidV) as reference images. Both, automatic and manual image registrations were applied. Shift differences were evaluated between the registered CT datasets for automatic and manual registration, respectively. Furthermore, differences between automatic and manual registration were analyzed for the same CT datasets. The registration results were statistically analyzed and correlated to tumor characteristics (3D tumor motion, tumor volume, superior-inferior (SI) distance, tumor environment). Median 3D shift differences over all patients were between 0.5 mm (AIPvsMIP) and 1.9 mm (MIPvsPCT and MidVvsPCT) for the automatic registration and between 1.8 mm (AIPvsPCT) and 2.8 mm (MIPvsPCT and MidVvsPCT) for the manual registration. For some patients, large shift differences (>5.0 mm) were found (maximum 10.5 mm, automatic registration). Comparing automatic vs manual registrations for the same reference CTs, ∆AIP achieved the smallest (1.1 mm) and ∆MIP the largest (1.9 mm) median 3D shift differences. The standard deviation (variability) for the 3D shift differences was also the smallest for ∆AIP (1.1 mm). Significant correlations (p < 0.01) between 3D shift difference and 3D tumor motion (AIPvsMIP, MIPvsMidV) and SI distance (AIPvsMIP) (automatic) and also for 3D tumor motion (∆PCT, ∆MidV; automatic vs manual) were found. Using different CT datasets for image registration with FB-CBCTs can result in different 3D couch shifts. Manual registrations achieved partly different 3D shifts than automatic registrations. AIP CTs yielded the smallest shift differences and might be the most appropriate CT dataset for registration with 3D FB-CBCTs.

Slow potentials in a melody recognition task.

PubMed

Verleger, R; Schellberg, D

1990-01-01

In a previous study, slow negative shifts were found in the EEG of subjects listening to well-known melodies. The two experiments reported here were designed to investigate the variables to which these slow potentials are related. In the first experiment, two opposite hypotheses were tested: The slow shifts might express subjects' acquaintance with the melodies or, on the contrary, the effort invested to identify them. To this end, some of the melodies were presented in the rhythms of other melodies to make recognition more difficult. Further, melodies rated as very well-known and as very unknown were analysed separately. However, the slow shifts were not affected by these experimental variations. Therefore in the second experiment, on the one hand the purely physical parameters intensity and duration were varied, but this variation had no impact on the slow shifts either. On the other hand, recognition was made more difficult by monotonously repeating the pitch of the 4th tone for the rest of some melodies. The slow negative shifts were enhanced with these monotonous melodies. This enhancement supports the "effort" hypothesis. Accordingly, the ofter shifts obtained in both experiments might likewise reflect effort. But since the task was not demanding, it is suggested that these constant shifts reflect the effort invested for coping with the entire underarousing situation rather than with the task. Frequently, slow eye movements occurred in the same time range as the slow potentials, resulting in EOG potentials spreading to the EEG recording sites. Yet results did not change substantially when the EEG recordings were corrected for the influence of EOG potentials.

Benchmarking quantum mechanical calculations with experimental NMR chemical shifts of 2-HADNT

NASA Astrophysics Data System (ADS)

Liu, Yuemin; Junk, Thomas; Liu, Yucheng; Tzeng, Nianfeng; Perkins, Richard

2015-04-01

In this study, both GIAO-DFT and GIAO-MP2 calculations of nuclear magnetic resonance (NMR) spectra were benchmarked with experimental chemical shifts. The experimental chemical shifts were determined experimentally for carbon-13 (C-13) of seven carbon atoms for the TNT degradation product 2-hydroxylamino-4,6-dinitrotoluene (2-HADNT). Quantum mechanics GIAO calculations were implemented using Becke-3-Lee-Yang-Parr (B3LYP) and other six hybrid DFT methods (Becke-1-Lee-Yang-Parr (B1LYP), Becke-half-and-half-Lee-Yang-Parr (BH and HLYP), Cohen-Handy-3-Lee-Yang-Parr (O3LYP), Coulomb-attenuating-B3LYP (CAM-B3LYP), modified-Perdew-Wang-91-Lee-Yang-Parr (mPW1LYP), and Xu-3-Lee-Yang-Parr (X3LYP)) which use the same correlation functional LYP. Calculation results showed that the GIAO-MP2 method gives the most accurate chemical shift values, and O3LYP method provides the best prediction of chemical shifts among the B3LYP and other five DFT methods. Three types of atomic partial charges, Mulliken (MK), electrostatic potential (ESP), and natural bond orbital (NBO), were also calculated using MP2/aug-cc-pVDZ method. A reasonable correlation was discovered between NBO partial charges and experimental chemical shifts of carbon-13 (C-13).

Dependence of Adaptive Cross-correlation Algorithm Performance on the Extended Scene Image Quality

NASA Technical Reports Server (NTRS)

Sidick, Erkin

2008-01-01

Recently, we reported an adaptive cross-correlation (ACC) algorithm to estimate with high accuracy the shift as large as several pixels between two extended-scene sub-images captured by a Shack-Hartmann wavefront sensor. It determines the positions of all extended-scene image cells relative to a reference cell in the same frame using an FFT-based iterative image-shifting algorithm. It works with both point-source spot images as well as extended scene images. We have demonstrated previously based on some measured images that the ACC algorithm can determine image shifts with as high an accuracy as 0.01 pixel for shifts as large 3 pixels, and yield similar results for both point source spot images and extended scene images. The shift estimate accuracy of the ACC algorithm depends on illumination level, background, and scene content in addition to the amount of the shift between two image cells. In this paper we investigate how the performance of the ACC algorithm depends on the quality and the frequency content of extended scene images captured by a Shack-Hatmann camera. We also compare the performance of the ACC algorithm with those of several other approaches, and introduce a failsafe criterion for the ACC algorithm-based extended scene Shack-Hatmann sensors.

Experimental studies of toroidal correlations of plasma density fluctuations along the magnetic field lines in the T-10 tokamak and first results of numerical modeling

NASA Astrophysics Data System (ADS)

Buldakov, M. A.; Vershkov, V. A.; Isaev, M. Yu; Shelukhin, D. A.

2017-10-01

The antenna system of reflectometry diagnostics at the T-10 tokamak allows to study long-range toroidal correlations of plasma density fluctuations along the magnetic field lines. The antenna systems are installed in two poloidal cross-sections of the vacuum chamber separated by a 90° angle in the toroidal direction. The experiments, which were conducted at the low field side, showed that the high level of toroidal correlations is observed only for quasi-coherent fluctuations. However, broadband and stochastic low frequency fluctuations are not correlated. Numerical modeling of the plasma turbulence structure in the T-10 tokamak was conducted to interpret the experimental results and take into account non-locality of reflectometry measurements. In the model used, it was assumed that the magnitudes of density fluctuations are constant along the magnetic field lines. The 2D full-wave Tamic-RTH code was used to model the reflectometry signals. High level of correlations for quasi-coherent fluctuations was obtained during the modeling, which agrees with the experimental observations. However, the performed modeling also predicts high level of correlations for broadband fluctuations, which contradicts the experimental data. The modeling showed that the effective reflection radius, from which the information on quasi-coherent plasma turbulence is obtained, is shifted outwards from the reflection radius by approximately 7 mm.

Dynamics of the bleaching of tail states in CdS1- x Se x mixed crystals

NASA Astrophysics Data System (ADS)

Breitkopf, T.; Kalt, H.; Klingshirn, C.; Reznitsky, A.

1996-06-01

The kinetics of excitons localized by statistic potential fluctuations have been studied in CdS 1-xSex ternary alloys under quasi-stationary excitation conditions and have been time resolved after picosecond-pulse excitation. In luminescence experiments we observe the filling of the band tail with rising excitation intensity. The reduction of carrier density with time by recombination leads to a red shift of the luminescence band after picosecond-pulse excitation. Bleaching of absorption of the localized states is found in pump-probe experiments. Its dynamics depend on the localization depth of the excitons and on the pump-pulse energy. Using higher excitation intensities, we observe stimulated emission in luminescence, correlated with significant changes in the behavior of the absorption bleaching. The possible origin of the stimulated emission situated in the spectral region of localized states is discussed.

Magneto-optical Kerr effect in L1{sub 0} FePdPt ternary alloys: Experiments and first-principles calculations

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

Ma, L.; Shi, Z.; Zhou, S. M., E-mail: wur@uci.edu, E-mail: shiming@tongji.edu.cn

2014-05-14

We have studied the magneto-optical Kerr effect (MOKE) of L1{sub 0} Fe{sub 0.5}(Pd{sub 1−x}Pt{sub x}){sub 0.5} alloy films with both experiments and first-principles calculations. In the visible region, negative Kerr rotation and ellipticity peaks are, respectively, observed in the regions of 1.5–2.0 eV and 1.7–2.6 eV. These peaks are shifted towards higher energies, and their magnitudes are enhanced for larger x. The MOKE evolution is mainly ascribed to the anomalous Hall conductivity contributed by the spin-down d{sub ↓,x{sup 2}−y{sup 2}} bands from Pd and Pt. We established a close correlation among the MOKE spectra, the spin orbit coupling strength, andmore » the band feature for this prototypical system.« less

Characterization and correction of charge-induced pixel shifts in DECam

DOE PAGES

Gruen, D.; Bernstein, G. M.; Jarvis, M.; ...

2015-05-28

Interaction of charges in CCDs with the already accumulated charge distribution causes both a flux dependence of the point-spread function (an increase of observed size with flux, also known as the brighter/fatter effect) and pixel-to-pixel correlations of the Poissonian noise in flat fields. We describe these effects in the Dark Energy Camera (DECam) with charge dependent shifts of effective pixel borders, i.e. the Antilogus et al. (2014) model, which we fit to measurements of flat-field Poissonian noise correlations. The latter fall off approximately as a power-law r -2.5 with pixel separation r, are isotropic except for an asymmetry in themore » direct neighbors along rows and columns, are stable in time, and are weakly dependent on wavelength. They show variations from chip to chip at the 20% level that correlate with the silicon resistivity. The charge shifts predicted by the model cause biased shape measurements, primarily due to their effect on bright stars, at levels exceeding weak lensing science requirements. We measure the flux dependence of star images and show that the effect can be mitigated by applying the reverse charge shifts at the pixel level during image processing. Differences in stellar size, however, remain significant due to residuals at larger distance from the centroid.« less

Experimental and theoretical study of substituent effect on 13C NMR chemical shifts of 5-arylidene-2,4-thiazolidinediones

NASA Astrophysics Data System (ADS)

Rančić, Milica P.; Trišović, Nemanja P.; Milčić, Miloš K.; Ajaj, Ismail A.; Marinković, Aleksandar D.

2013-10-01

The electronic structure of 5-arylidene-2,4-thiazolidinediones has been studied by using experimental and theoretical methodology. The theoretical calculations of the investigated 5-arylidene-2,4-thiazolidinediones have been performed by the use of quantum chemical methods. The calculated 13C NMR chemical shifts and NBO atomic charges provide an insight into the influence of such a structure on the transmission of electronic substituent effects. Linear free energy relationships (LFERs) have been further applied to their 13C NMR chemical shifts. The correlation analyses for the substituent-induced chemical shifts (SCS) have been performed with σ using SSP (single substituent parameter), field (σF) and resonance (σR) parameters using DSP (dual substituent parameter), as well as the Yukawa-Tsuno model. The presented correlations account satisfactorily for the polar and resonance substituent effects operative at Cβ, and C7 carbons, while reverse substituent effect was found for Cα. The comparison of correlation results for the investigated molecules with those obtained for seven structurally related styrene series has indicated that specific cross-interaction of phenyl substituent and groups attached at Cβ carbon causes increased sensitivity of SCS Cβ to the resonance effect with increasing of electron-accepting capabilities of the group present at Cβ.

Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand.

PubMed

Loutit, T S; Kennett, J P

1979-06-15

A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.

Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review.

PubMed

Booker, Lauren A; Magee, Michelle; Rajaratnam, Shantha M W; Sletten, Tracey L; Howard, Mark E

2018-03-27

Shift workers often experience reduced sleep quality, duration and/or excessive sleepiness due to the imposed conflict between work and their circadian system. About 20-30% of shift workers experience prominent insomnia symptoms and excessive daytime sleepiness consistent with the circadian rhythm sleep disorder known as shift work disorder. Individual factors may influence this vulnerability to shift work disorder or sleep-related impairment associated with shift work. This paper was registered with Prospero and was conducted using recommended standards for systematic reviews and meta-analyses. Published literature that measured sleep-related impairment associated with shift work including reduced sleep quality and duration and increased daytime sleepiness amongst healthcare shift workers and explored characteristics associated with individual variability were reviewed. Fifty-eight studies were included. Older age, morning-type, circadian flexibility, being married or having children, increased caffeine intake, higher scores on neuroticism and lower on hardiness were related to a higher risk of sleep-related impairment in response to shift work, whereas physical activity was a protective factor. The review highlights the diverse range of measurement tools used to evaluate the impact of shift work on sleep. Use of standardised and validated tools would enable cross-study comparisons. Longitudinal studies are required to establish causal relationships between individual factors and the development of shift work disorder. Copyright © 2018 Elsevier Ltd. All rights reserved.

Serial, Covert, Shifts of Attention during Visual Search are Reflected by the Frontal Eye Fields and Correlated with Population Oscillations

PubMed Central

Buschman, Timothy J.; Miller, Earl K.

2009-01-01

Attention regulates the flood of sensory information into a manageable stream, and so understanding how attention is controlled is central to understanding cognition. Competing theories suggest visual search involves serial and/or parallel allocation of attention, but there is little direct, neural, evidence for either mechanism. Two monkeys were trained to covertly search an array for a target stimulus under visual search (endogenous) and pop-out (exogenous) conditions. Here we present neural evidence in the frontal eye fields (FEF) for serial, covert shifts of attention during search but not pop-out. Furthermore, attention shifts reflected in FEF spiking activity were correlated with 18–34 Hz oscillations in the local field potential, suggesting a ‘clocking’ signal. This provides direct neural evidence that primates can spontaneously adopt a serial search strategy and that these serial covert shifts of attention are directed by the FEF. It also suggests that neuron population oscillations may regulate the timing of cognitive processing. PMID:19679077

Measurements of ultrasonic backscattered spectral centroid shift from spine in vivo: methodology and preliminary results.

PubMed

Garra, Brian S; Locher, Melanie; Felker, Steven; Wear, Keith A

2009-01-01

Ultrasonic backscatter measurements from vertebral bodies (L3 and L4) in nine women were performed using a clinical ultrasonic imaging system. Measurements were made through the abdomen. The location of a vertebra was identified from the bright specular reflection from the vertebral anterior surface. Backscattered signals were gated to isolate signal emanating from the cancellous interiors of vertebrae. The spectral centroid shift of the backscattered signal, which has previously been shown to correlate highly with bone mineral density (BMD) in human calcaneus in vitro, was measured. BMD was also measured in the nine subjects' vertebrae using a clinical bone densitometer. The correlation coefficient between centroid shift and BMD was r = -0.61. The slope of the linear fit was -160 kHz / (g/cm(2)). The negative slope was expected because the attenuation coefficient (and therefore magnitude of the centroid downshift) is known from previous studies to increase with BMD. The centroid shift may be a useful parameter for characterizing bone in vivo.

Dynamic Frequency Shifts of Complexed Ligands: An NMR Study of D-[1- 13C,1- 2H]Glucose Complexed to the Escherichia coliPeriplasmic Glucose/Galactose Receptor

NASA Astrophysics Data System (ADS)

Gabel, Scott A.; Luck, Linda A.; Werbelow, Lawrence G.; London, Robert E.

1997-10-01

The13C multiplet structure ofD-[1-13C,1-2H]glucose complexed to theEscherichia coliperiplasmic glucose/galactose receptor has been studied as a function of temperature. Asymmetric multiplet patterns observed are shown to arise from dynamic frequency shifts. Multiplet asymmetry contributions resulting from shift anisotropy-dipolar cross correlations were found to be small, with optimal fits of the data corresponding to small, negative values of the correlation factor, χCD-CSA. Additional broadening at higher temperatures most probably results from ligand exchange between free and complexed states. Effects of internal motion are also considered theoretically, and indicate that the order parameter for the bound glucose is ≥0.9.

Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

NASA Astrophysics Data System (ADS)

Zhang, Rongchun; Ramamoorthy, Ayyalusamy

2015-05-01

Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90° RF pulses) to selectively measure the correlation of 1H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90° pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1H/1H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials.

Survival of the Partial Reinforcement Extinction Effect after Contextual Shifts

ERIC Educational Resources Information Center

Boughner, Robert L.; Papini, Mauricio R.

2006-01-01

The effects of contextual shifts on the partial reinforcement extinction effect (PREE) were studied in autoshaping with rats. Experiment 1 established that the two contexts used subsequently were easily discriminable and equally salient. In Experiment 2, independent groups of rats received acquisition training under partial reinforcement (PRF) or…

Feedback shift register sequences versus uniformly distributed random sequences for correlation chromatography

NASA Technical Reports Server (NTRS)

Kaljurand, M.; Valentin, J. R.; Shao, M.

1996-01-01

Two alternative input sequences are commonly employed in correlation chromatography (CC). They are sequences derived according to the algorithm of the feedback shift register (i.e., pseudo random binary sequences (PRBS)) and sequences derived by using the uniform random binary sequences (URBS). These two sequences are compared. By applying the "cleaning" data processing technique to the correlograms that result from these sequences, we show that when the PRBS is used the S/N of the correlogram is much higher than the one resulting from using URBS.

Shape shifting: Local landmarks interfere with navigation by, and recognition of, global shape.

PubMed

Buckley, Matthew G; Smith, Alastair D; Haselgrove, Mark

2014-03-01

An influential theory of spatial navigation states that the boundary shape of an environment is preferentially encoded over and above other spatial cues, such that it is impervious to interference from alternative sources of information. We explored this claim with 3 intradimensional-extradimensional shift experiments, designed to examine the interaction of landmark and geometric features of the environment in a virtual navigation task. In Experiments 1 and 2, participants were first required to find a hidden goal using information provided by the shape of the arena or landmarks integrated into the arena boundary (Experiment 1) or within the arena itself (Experiment 2). Participants were then transferred to a different-shaped arena that contained novel landmarks and were again required to find a hidden goal. In both experiments, participants who were navigating on the basis of cues that were from the same dimension that was previously relevant (intradimensional shift) learned to find the goal significantly faster than participants who were navigating on the basis of cues that were from a dimension that was previously irrelevant (extradimensional shift). This suggests that shape information does not hold special status when learning about an environment. Experiment 3 replicated Experiment 2 and also assessed participants' recognition of the global shape of the navigated arenas. Recognition was attenuated when landmarks were relevant to navigation throughout the experiment. The results of these experiments are discussed in terms of associative and non-associative theories of spatial learning.

Lensing corrections to features in the angular two-point correlation function and power spectrum

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

LoVerde, Marilena; Department of Physics, Columbia University, New York, New York 10027; Hui, Lam

2008-01-15

It is well known that magnification bias, the modulation of galaxy or quasar source counts by gravitational lensing, can change the observed angular correlation function. We investigate magnification-induced changes to the shape of the observed correlation function w({theta}), and the angular power spectrum C{sub l}, paying special attention to the matter-radiation equality peak and the baryon wiggles. Lensing effectively mixes the correlation function of the source galaxies with that of the matter correlation at the lower redshifts of the lenses distorting the observed correlation function. We quantify how the lensing corrections depend on the width of the selection function, themore » galaxy bias b, and the number count slope s. The lensing correction increases with redshift and larger corrections are present for sources with steep number count slopes and/or broad redshift distributions. The most drastic changes to C{sub l} occur for measurements at high redshifts (z > or approx. 1.5) and low multipole moment (l < or approx. 100). For the source distributions we consider, magnification bias can shift the location of the matter-radiation equality scale by 1%-6% at z{approx}1.5 and by z{approx}3.5 the shift can be as large as 30%. The baryon bump in {theta}{sup 2}w({theta}) is shifted by < or approx. 1% and the width is typically increased by {approx}10%. Shifts of > or approx. 0.5% and broadening > or approx. 20% occur only for very broad selection functions and/or galaxies with (5s-2)/b > or approx. 2. However, near the baryon bump the magnification correction is not constant but is a gently varying function which depends on the source population. Depending on how the w({theta}) data is fitted, this correction may need to be accounted for when using the baryon acoustic scale for precision cosmology.« less

Triage level assignment and nurse characteristics and experience.

PubMed

Gómez-Angelats, Elisenda; Miró, Òscar; Bragulat Baur, Ernesto; Antolín Santaliestra, Alberto; Sánchez Sánchez, Miquel

2018-06-01

To study the relation between nursing staff demographics and experience and their assignment of triage level in the emergency department. One-year retrospective observational study in the triage area of a tertiary care urban university hospital that applies the Andorran-Spanish triage model. Variables studied were age, gender, nursing experience, triage experience, shift, usual level of emergency work the nurse undertakes, number of triage decisions made, and percentage of patients assigned to each level. Fifty nurses (5 men, 45 women) with a mean (SD) age of 45 (9) years triaged 67 803 patients during the year. Nurses classified more patients in level 5 on the morning shift (7.9%) than on the afternoon shift (5.5%) (P=.003). The difference in the rate of level-5 triage classification became significant when nurses were older (β = 0.092, P=.037) and experience was greater (β = 0.103, P=.017). The number of triages recorded by a nurse was significantly and directly related to the percentage of patients assigned to level 3 (β = 0.003, P=.006) and inversely related to the percentages assigned to level 4 (β = -0.002, P=.008) and level 5 (β = -0.001, P=.017). We found that triage level assignments were related to age, experience, shift, and total number of patients triaged by a nurse.

Cross-scale interactions drive ecosystem responses to precipitation in the Chihuahuan Desert

USDA-ARS?s Scientific Manuscript database

Regime shifts from grass- to shrub-dominated states are widespread in arid and semiarid regions globally. These patterns of grass production and shifts to shrub dominance are spatially variable and correlate weakly with precipitation, suggesting that processes at different spatial and temporal scale...

Object-based attention in chimpanzees (Pan troglodytes).

PubMed

Ushitani, Tomokazu; Imura, Tomoko; Tomonaga, Masaki

2010-03-17

We conducted three experiments to investigate how object-based components contribute to the attentional processes of chimpanzees and to examine how such processes operate with regard to perceptually structured objects. In Experiment 1, chimpanzees responded to a spatial cueing task that required them to touch a target appearing at either end of two parallel rectangles. We compared the time involved in shifting attention (cost of attentional shift) when the locations of targets were cued and non cued. Results showed that the cost of the attentional shift within one rectangle was smaller than that beyond the object's boundary, demonstrating object-based attention in chimpanzees. The results of Experiment 2, conducted with different stimulus configurations, replicated the results of Experiment 1, supporting that object-based attention operates in chimpanzees. In Experiment 3, the cost of attentional shift within a cued but partly occluded rectangle was shorter than that within a rectangle that was cued but divided in the middle. The results suggest that the attention of chimpanzees is activated not only by an explicit object but also by fragmented patches represented as an object at a higher-order perceptual level. Chimpanzees' object-based attention may be similar to that of humans. Copyright 2010 Elsevier Ltd. All rights reserved.

Species selection under long-term experimental warming and drought explained by climatic distributions.

PubMed

Liu, Daijun; Peñuelas, Josep; Ogaya, Romà; Estiarte, Marc; Tielbörger, Katja; Slowik, Fabian; Yang, Xiaohong; Bilton, Mark C

2018-03-01

Global warming and reduced precipitation may trigger large-scale species losses and vegetation shifts in ecosystems around the world. However, currently lacking are practical ways to quantify the sensitivity of species and community composition to these often-confounded climatic forces. Here we conducted long-term (16 yr) nocturnal-warming (+0.6°C) and reduced precipitation (-20% soil moisture) experiments in a Mediterranean shrubland. Climatic niche groups (CNGs) - species ranked or classified by similar temperature or precipitation distributions - informatively described community responses under experimental manipulations. Under warming, CNGs revealed that only those species distributed in cooler regions decreased. Correspondingly, under reduced precipitation, a U-shaped treatment effect observed in the total community was the result of an abrupt decrease in wet-distributed species, followed by a delayed increase in dry-distributed species. Notably, while partially correlated, CNG explanations of community response were stronger for their respective climate parameter, suggesting some species possess specific adaptations to either warming or drought that may lead to independent selection to the two climatic variables. Our findings indicate that when climatic distributions are combined with experiments, the resulting incorporation of local plant evolutionary strategies and their changing dynamics over time leads to predictable and informative shifts in community structure under independent climate change scenarios. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Phase-Shift Interferometry with a Digital Photocamera

ERIC Educational Resources Information Center

Vannoni, Maurizio; Trivi, Marcelo; Molesini, Giuseppe

2007-01-01

A phase-shift interferometry experiment is proposed, working on a Twyman-Green optical configuration with additional polarization components. A guideline is provided to modern phase-shift interferometry, using concepts and laboratory equipment at the level of undergraduate optics courses. (Contains 5 figures.)

Relationship Between Audio-Vestibular Functional Tests and Inner Ear MRI in Meniere's Disease.

PubMed

Quatre, Raphaële; Attyé, Arnaud; Karkas, Alexandre; Job, Agnès; Dumas, Georges; Schmerber, Sébastien

2018-04-25

Meniere's disease is an inner ear disorder generally attributed to an endolymphatic hydrops. Different electrophysiological tests and imaging techniques have been developed to improve endolymphatic hydrops diagnosis. The goal of our study was to compare the sensitivity and the specificity of delayed inner ear magnetic resonance imaging (MRI) after intravenous injection of gadolinium with extratympanic clicks electrocochleography (EcochG), phase shift of distortion product otoacoustic emissions (shift-DPOAEs), and cervical vestibular-evoked myogenic potentials (cVEMP) for the diagnosis of Meniere's disease. Forty-one patients, with a total of 50 affected ears, were included prospectively from April 2015 to April 2016 in our institution. Patients included had definite or possible Meniere's disease based on the latest American Academy of Otolaryngology-Head and Neck Surgery guidelines revised in 2015. All patients went through delayed inner ear MRI after intravenous injection of gadolinium (three dimension-fluid attenuated inversion recovery sequences), pure-tone audiometry, extratympanic clicks EcochG, shift-DPOAEs, and cVEMP on the same day. Endolymphatic hydrops was graded on MRI using the saccule to utricle ratio inversion defined as when the saccule appeared equal or larger than the utricle. Abnormal EcochG and shift-DPOAEs in patients with definite Meniere's disease (DMD) were found in 68 and 64.5%, respectively. The two methods were significantly associated in DMD group. In DMD group, 25.7% had a positive MRI. The correlation between MRI versus EcochG and MRI versus shift-DPOAEs was not significant. MRI hydrops detection was correlated with hearing loss. Finally, 22.9% of DMD group had positive cVEMP. EcochG and shift-DPOAEs were both well correlated with clinical criteria of Meniere's disease. Inner ear MRI showed hydrops when hearing loss was higher than 35 dB. The shift-DPOAEs presented the advantage of a rapid and easy measurement if DPOAEs could be recorded (i.e., hearing threshold <60dB). In contrast, EcochG can be performed regardless of hearing loss. In combination with shift-DPOAEs, it enhances the chances to confirm the diagnosis with a better confidence.

Revealing Nanostructures through Plasmon Polarimetry.

PubMed

Kleemann, Marie-Elena; Mertens, Jan; Zheng, Xuezhi; Cormier, Sean; Turek, Vladimir; Benz, Felix; Chikkaraddy, Rohit; Deacon, William; Lombardi, Anna; Moshchalkov, Victor V; Vandenbosch, Guy A E; Baumberg, Jeremy J

2017-01-24

Polarized optical dark-field spectroscopy is shown to be a versatile noninvasive probe of plasmonic structures that trap light to the nanoscale. Clear spectral polarization splittings are found to be directly related to the asymmetric morphology of nanocavities formed between faceted gold nanoparticles and an underlying gold substrate. Both experiment and simulation show the influence of geometry on the coupled system, with spectral shifts Δλ = 3 nm from single atoms. Analytical models allow us to identify the split resonances as transverse cavity modes, tightly confined to the nanogap. The direct correlation of resonance splitting with atomistic morphology allows mapping of subnanometre structures, which is crucial for progress in extreme nano-optics involving chemistry, nanophotonics, and quantum devices.

Motion detection using extended fractional Fourier transform and digital speckle photography.

PubMed

Bhaduri, Basanta; Tay, C J; Quan, C; Sheppard, Colin J R

2010-05-24

Digital speckle photography is a useful tool for measuring the motion of optically rough surfaces from the speckle shift that takes place at the recording plane. A simple correlation based digital speckle photographic system has been proposed that implements two simultaneous optical extended fractional Fourier transforms (EFRTs) of different orders using only a single lens and detector to simultaneously detect both the magnitude and direction of translation and tilt by capturing only two frames: one before and another after the object motion. The dynamic range and sensitivity of the measurement can be varied readily by altering the position of the mirror/s used in the optical setup. Theoretical analysis and experiment results are presented.

Quench dynamics in strongly correlated Bose-Hubbard chains

NASA Astrophysics Data System (ADS)

Naegerl, Hanns-Christoph

2013-05-01

We present a series of experiments in the context of 1D physics with ultracold atoms, combining optical lattice potentials with the capability to tune the strength of the onsite particle interaction U. For an array of tilted 1D chains with site-to-site tilt E and initial unity occupation we record the dynamics after a quench to the phase transition point U ~E by monitoring the number of doublons created as a function of time after the quench. We observe characteristic oscillations from which we deduce a shift of the resonance condition as time progresses. For U/2 ~E and U/3 ~E we observe coupling to next-nearest neighbors and beyond.

Automated electroencephalography system and electroencephalographic correlates of space motion sickness, part 3

NASA Technical Reports Server (NTRS)

Frost, J. D., Jr.

1977-01-01

Computer quantification methods were used to analyze the Skylab electroencephalographic data obtained during the course of the M133 series of experiments. This undertaking was prompted by initial observations made during visual analysis of the tape-recorded sleep records where there appeared to be an increase of the alpha-rhythm frequency during some inflight recording sessions, as compared to preflight baseline observations. A number of potential etiological factors are identified and their various possible influences discussed. The presence of the zero-g state is thought to be an important factor, possibly influencing EEG through alteration of vestibular function and/or by producing fluid shifts secondary to loss of hydrostatic pressure.

The interprofessional learning experience: Findings from a qualitative study based in an outpatient setting.

PubMed

Jakobsen, Flemming; Mørcke, Anne Mette; Hansen, Torben Bæk

2017-09-01

Clinical interprofessional education has traditionally taken place in hospital wards, but much diagnosis and treatment have shifted to the outpatient setting. The logical consequence is to shift more students' clinical placements from the "bedside" to outpatient settings. However, it is unclear how we ensure that this shift maximises learning. The purpose of this article is to understand the authentic learning experience in an interprofessional outpatient clinic setting. We performed an exploratory case study with interviews of four nursing students, 13 medical students, and six staff members who worked in an interprofessional outpatient orthopaedic clinic from March 2015 to January 2016. The interviews were transcribed and analysed using systematic text condensation. The students' self-reported learning experience in this outpatient clinic was characterised by direct patient contact and by authentic, interprofessional, task-based learning, and a preference for indirect supervision when conducting uncomplicated patient consultations. The supervisors intended to create this interprofessional outpatient clinic experience by having a clear teaching approach based on adult learning principles in a safe and challenging learning environment. The shift to the outpatient setting was strongly and practically supported by the management. This study indicates that student learning can be shifted to the outpatient clinic setting if there is supportive management and dedicated supervisors who establish a challenging yet safe interprofessional learning environment.

Indirect detection of infinite-speed MAS solid-state NMR spectra

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

Perras, Frédéric A.; Venkatesh, Amrit; Hanrahan, Michael P.

Heavy spin-1/2 nuclides are known to possess very large chemical shift anisotropies that can challenge even the most advanced magic-angle-spinning (MAS) techniques. Wide manifolds of overlapping spinning sidebands and insufficient excitation bandwidths often obfuscate meaningful spectral information and force the use of static, low-resolution solid-state (SS)NMR methods for the characterization of materials. In order to address these issues, we have merged fast-magic-angle-turning (MAT) and dipolar heteronuclear multiple-quantum coherence (D-HMQC) experiments to obtain D-HMQC-MAT pulse sequences which enable the rapid acquisition of 2D SSNMR spectra that correlate isotropic 1H chemical shifts to the indirectly detected isotropic “infinite-MAS” spectra of heavy spin-1/2more » nuclides. Furthermore, for these nuclides, the combination of fast MAS and 1H detection provides a high sensitivity, which rivals the DNP-enhanced ultra-wideline SSNMR. The new pulse sequences were used to determine the Pt coordination environments in a complex mixture of decomposition products of transplatin and in a metal-organic framework with Pt ions coordinated to the linker ligands.« less

Theoretical Modeling of 99 Tc NMR Chemical Shifts

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

Hall, Gabriel B.; Andersen, Amity; Washton, Nancy M.

Technetium (Tc) displays a rich chemistry due to the wide range of oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and 99Tc NMR spec-troscopy is widely used to probe chemical environments of Tc in odd oxidation states. However interpretation of the 99Tc NMR data is hindered by the lack of reference compounds. DFT computations can help fill this gap, but to date few com-putational studies have focused on 99Tc NMR of compounds and complexes. This work systematically evaluates the inclu-sion small percentages of Hartree-Fock exchangemore » correlation and relativistic effects in DFT computations to support in-terpretation of the 99Tc NMR spectra. Hybrid functionals are found to perform better than their pure GGA counterparts, and non-relativistic calculations have been found to generally show a lower mean absolute deviation from experiment. Overall non-relativistic PBE0 and B3PW91 calculations are found to most accurately predict 99Tc NMR chemical shifts.« less

Indirect detection of infinite-speed MAS solid-state NMR spectra

DOE PAGES

Perras, Frédéric A.; Venkatesh, Amrit; Hanrahan, Michael P.; ...

2017-01-18

Heavy spin-1/2 nuclides are known to possess very large chemical shift anisotropies that can challenge even the most advanced magic-angle-spinning (MAS) techniques. Wide manifolds of overlapping spinning sidebands and insufficient excitation bandwidths often obfuscate meaningful spectral information and force the use of static, low-resolution solid-state (SS)NMR methods for the characterization of materials. In order to address these issues, we have merged fast-magic-angle-turning (MAT) and dipolar heteronuclear multiple-quantum coherence (D-HMQC) experiments to obtain D-HMQC-MAT pulse sequences which enable the rapid acquisition of 2D SSNMR spectra that correlate isotropic 1H chemical shifts to the indirectly detected isotropic “infinite-MAS” spectra of heavy spin-1/2more » nuclides. Furthermore, for these nuclides, the combination of fast MAS and 1H detection provides a high sensitivity, which rivals the DNP-enhanced ultra-wideline SSNMR. The new pulse sequences were used to determine the Pt coordination environments in a complex mixture of decomposition products of transplatin and in a metal-organic framework with Pt ions coordinated to the linker ligands.« less

Anticipating abrupt shifts in temporal evolution of probability of eruption

NASA Astrophysics Data System (ADS)

Rohmer, J.; Loschetter, A.

2016-04-01

Estimating the probability of eruption by jointly accounting for different sources of monitoring parameters over time is a key component for volcano risk management. In the present study, we are interested in the transition from a state of low-to-moderate probability value to a state of high probability value. By using the data of MESIMEX exercise at the Vesuvius volcano, we investigated the potential for time-varying indicators related to the correlation structure or to the variability of the probability time series for detecting in advance this critical transition. We found that changes in the power spectra and in the standard deviation estimated over a rolling time window both present an abrupt increase, which marks the approaching shift. Our numerical experiments revealed that the transition from an eruption probability of 10-15% to > 70% could be identified up to 1-3 h in advance. This additional lead time could be useful to place different key services (e.g., emergency services for vulnerable groups, commandeering additional transportation means, etc.) on a higher level of alert before the actual call for evacuation.

Indirect detection of infinite-speed MAS solid-state NMR spectra

NASA Astrophysics Data System (ADS)

Perras, Frédéric A.; Venkatesh, Amrit; Hanrahan, Michael P.; Goh, Tian Wei; Huang, Wenyu; Rossini, Aaron J.; Pruski, Marek

2017-03-01

Heavy spin-1/2 nuclides are known to possess very large chemical shift anisotropies that can challenge even the most advanced magic-angle-spinning (MAS) techniques. Wide manifolds of overlapping spinning sidebands and insufficient excitation bandwidths often obfuscate meaningful spectral information and force the use of static, low-resolution solid-state (SS)NMR methods for the characterization of materials. To address these issues, we have merged fast-magic-angle-turning (MAT) and dipolar heteronuclear multiple-quantum coherence (D-HMQC) experiments to obtain D-HMQC-MAT pulse sequences which enable the rapid acquisition of 2D SSNMR spectra that correlate isotropic 1H chemical shifts to the indirectly detected isotropic "infinite-MAS" spectra of heavy spin-1/2 nuclides. For these nuclides, the combination of fast MAS and 1H detection provides a high sensitivity, which rivals the DNP-enhanced ultra-wideline SSNMR. The new pulse sequences were used to determine the Pt coordination environments in a complex mixture of decomposition products of transplatin and in a metal-organic framework with Pt ions coordinated to the linker ligands.

Effect of the 1997 El Niño on the distribution of upper tropospheric cirrus

NASA Astrophysics Data System (ADS)

Massie, Steven; Lowe, Paul; Tie, Xuexi; Hervig, Mark; Thomas, Gary; Russell, James

2000-09-01

Geographical distributions of Halogen Occultation Experiment (HALOE) aerosol extinction data for 1993-1998 are analyzed in the troposphere and stratosphere at pressures between 121 and 46 hPa. The El Niño conditions of 1997 increased upper tropospheric cirrus over the mid-Pacific and decreased cirrus over Indonesia. Longitudinal centroids of cirrus in the Pacific and over Indonesia shifted eastward by 25° in the troposphere in 1997. Longitudinal centroids of aerosol in the lower stratosphere do not exhibit longitudinal shifts in 1997, indicating that the effects of El Niño upon equatorial particle distributions are confined to the troposphere. The correlation of the longitudinal centroids of outgoing longwave radiation and HALOE extinction confirms the spatial relationship between deep convective clouds and upper tropospheric cirrus. The number of cirrus events observed each year in 1993-1998 in the upper troposphere are quite similar for the region from the Indian Ocean to the mid-Pacific (30°S to 30°N, 50° to 240°E).

Fluid Shifts Before, During, and After Prolonged Space Flight and their Association with Intracranial Pressure and Visual Impairment

NASA Technical Reports Server (NTRS)

Stenger, M.; Lee, S.; Platts, S.; Macias, B.; Lui, J.; Ebert, D.; Sargsyan, A.; Dulchavsky, S.; Alferova, I.; Yarmanova, E.;

Elymus repens biomass allocation and acquisition as affected by light and nutrient supply and companion crop competition

PubMed Central

Ringselle, Björn; Prieto-Ruiz, Inés; Andersson, Lars; Aronsson, Helena; Bergkvist, Göran

2017-01-01

Background and Aims Competitive crops are a central component of resource-efficient weed control, especially for problematic perennial weeds such as Elymus repens. Competition not only reduces total weed biomass, but denial of resources can also change the allocation pattern – potentially away from the underground storage organs that make perennial weeds difficult to control. Thus, the competition mode of crops may be an important component in the design of resource-efficient cropping systems. Our aim was to determine how competition from companion crops with different modes of competition affect E. repens biomass acquisition and allocation and discuss that in relation to how E. repens responds to different levels of light and nutrient supply. Methods Greenhouse experiments were conducted with E. repens growing in interspecific competition with increasing density of perennial ryegrass or red clover, or growing at three levels of both light and nutrient supply. Key Results Elymus repens total biomass decreased with increasing biomass of the companion crop and the rate of decrease was higher with red clover than with perennial ryegrass, particularly for E. repens rhizome biomass. A reduced nutrient supply shifted E. repens allocation towards below-ground biomass while a reduced light supply shifted it towards shoot biomass. Red clover caused no change in E. repens allocation pattern, while ryegrass mostly shifted the allocation towards below-ground biomass, but the change was not correlated with ryegrass biomass. Conclusions The companion crop mode of competition influences both the suppression rate of E. repens biomass acquisition and the likelihood of shifts in E. repens biomass allocation. PMID:28025285

Gray matter regions statistically mediating the cross-sectional association of eotaxin and set-shifting among older adults with major depressive disorder.

PubMed

Smagula, Stephen F; Karim, Helmet T; Lenze, Eric J; Butters, Meryl A; Wu, Gregory F; Mulsant, Benoit H; Reynolds, Charles F; Aizenstein, Howard J

2017-12-01

Eotaxin is a chemokine that exerts negative effects on neurogenesis. We recently showed that peripheral eotaxin levels correlate with both lower gray matter volume and poorer executive performance in older adults with major depressive disorder. These findings suggest that the relationship between eotaxin and set-shifting may be accounted for by lower gray matter volume in specific regions. Prior studies have identified specific gray matter regions that correlate with set-shifting performance, but have not examined whether these specific gray matter regions mediate the cross-sectional association between eotaxin and set-shifting. In 27 older adults (mean age: 68 ± 5.2 years) with major depressive disorder, we performed a whole brain (voxel-wise) analysis testing whether/where gray matter density statistically mediates the cross-sectional association of eotaxin and set-shifting performance. We found the association between eotaxin and set-shifting performance was fully statistically mediated by lower gray matter density in left middle cingulate, right pre-/post-central, lingual, inferior/superior frontal, cuneus, and middle temporal regions. The regions identified above may be both susceptible to a potential neurodegenerative effect of eotaxin, and critical to preserving set-shifting function. Longitudinal and intervention studies are needed to further evaluate whether targeting eotaxin levels will prevent neurodegeneration and executive impairment in older adults with depression. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The integration of nonsimultaneous frequency components into a single virtual pitch.

PubMed

Ciocca, V; Darwin, C J

1999-04-01

The integration of nonsimultaneous frequency components into a single virtual pitch was investigated by using a pitch matching task in which a mistuned 4th harmonic (mistuned component) produced pitch shifts in a harmonic series (12 equal-amplitude harmonics of a 155-Hz F0). In experiment 1, the mistuned component could either be simultaneous, stop as the target started (pre-target component), or start as the target stopped (post-target component). Pitch shifts produced by the pre-target components were significantly smaller than those obtained with simultaneous components; in the post-target condition, the size of pitch shifts did not decrease relative to the simultaneous condition. In experiment 2, a silent gap of 20, 40, 80, or 160 ms was introduced between the nonsimultaneous components and the target sound. In the pre-target condition, pitch shifts were reduced to zero for silent gaps of 80 ms or longer; by contrast, a gap of 160 ms was required to eliminate pitch shifts in the post-target condition. The third experiment tested the hypothesis that, when post-target components were presented, the processing of the pitch of the target tone started at the onset of the target, and ended at the gap duration at which pitch shifts decreased to zero. This hypothesis was confirmed by the finding that pitch shifts could not be observed when the target tone had a duration of 410 ms. Taken together, the results of these experiments show that nonsimultaneous components that occur after the onset of the target sound make a larger contribution to the virtual pitch of the target, and over a longer period, than components that precede the onset of the target sound.

A source mechanism producing HF-induced plasma lines (HFPLS) with up-shifted frequencies

NASA Technical Reports Server (NTRS)

Kuo, S. P.; Lee, M. C.

1992-01-01

Attention is given to a nonlinear scattering process analyzed as a source mechanism producing the frequency up-shifted HFPLs observed in the Arecibo ionospheric heating experiments. A physical picture is offered to explain how Langmuir waves with frequencies greater than the HF heater wave frequency can be produced in the heating experiments and be detected by incoherent radars as frequency up-shifted HFPLs. Since the considered scattering process occurs in a region near the reflection height, it explains why the frequency up-shifted HFPLs should originate from the altitude near the reflection height as observed. The theory also shows that the amount of frequency up-shift is inversely proportional to the frequency of the HF heater and increases linearly with the electron temperature. The quantitative analysis of the theory shows a good agreement with the experimental results.

Structured teleconnections reveal the South American monsoon onset: A network approach

NASA Astrophysics Data System (ADS)

Ciemer, Catrin; Ekhtiari, Nikoo; Barbosa, Henrique; Boers, Niklas; Donner, Reik; Kurths, Jürgen; Rammig, Anja; Winkelmann, Ricarda

2017-04-01

The regional onset dates of the global monsoon systems are, to first order, determined by the seasonal shift of the intertropical convergence zone. However, precise onset dates vary substantially from year to year due to the complexity of the involved mechanisms. In this study, we investigate processes determining the onset of the South American monsoon system (SAMS). In recent years, a trend towards later onset dates of the SAMS has been observed. A later onset of the monsoon can have severe impacts on agriculture and infrastructure such as farming, water transport routes, and the stability of the Amazon rainforest in the long term. Possible reasons for this shift involve a multitude of climatic phenomena and variables relevant for the SAMS. To account for the highly interactive nature of the SAMS, we here investigate it with the help of complex networks. By studying the temporal changes of the correlation structure in spatial rainfall networks, we are able to determine coherent areas of similar precipitation patterns, spot teleconnections in terms of strongly correlated areas, detect key regions for precipitation correlations, and finally reveal the monsoon onset by an abrupt shift from an unordered to an ordered correlation structure of the network. To further evaluate the shift in the monsoon onset, we couple our rainfall network to a network of climate networks using sea surface temperature as a second variable. We are thereby able to emphasize oceanic regions that are particularly important for the SAMS and anticipate the influence of future changes of sea-surface temperature on the SAMS.

Developing Competency-Based Advising Practices in Response to Paradigm Shifts in Higher Education

ERIC Educational Resources Information Center

Walters, Giovanna

2016-01-01

Competency-based programs have gained prominence in recent years for two primary reasons. First, more students are seeking ways to apply nonclassroom learning experiences toward a degree. Second, a paradigm shift in higher education encourages postsecondary curriculum developers to accept nonclassroom experiences as demonstrations of skills and…

New Teachers' Identity Shifts at the Boundary of Teacher Education and Initial Practice

ERIC Educational Resources Information Center

Beauchamp, Catherine; Thomas, Lynn

2011-01-01

As teachers enter the school communities of their initial practice, they experience identity shifts that reflect their learning. Throughout teacher education they have constructed an identity informed by their previous school experiences, the ideas and approaches promoted by their teacher education programs, and an ideal of the teachers they hope…

The Instructor Experience of Fully Online Tertiary Mathematics: A Challenge and an Opportunity

ERIC Educational Resources Information Center

Trenholm, Sven; Alcock, Lara; Robinson, Carol

2016-01-01

As part of a dramatic recent shift in tertiary education, many undergraduate students now learn mathematics via fully online courses. At present, the mathematics education research community knows very little about this shift. The authors consider implications of an investigation into the instructor experience of fully online undergraduate…

Multiscale drivers of spatially variable grass production and loss in the Chihuahuan Desert

USDA-ARS?s Scientific Manuscript database

Historic regime shifts from grass- to shrub-dominated states have been widespread in the Chihuahuan Desert and other arid and semiarid regions globally. These patterns of grass production and shifts to shrub dominance are spatially variable, and show a weak correlation with precipitation, suggesting...

Predictive factors of life quality among packaging workers in Taiwan.

PubMed

Yang, Shang-Yu; Hsu, Der-Jen; Yen, Chun-Ming; Chang, Jer-Hao

2018-05-16

The semiconductor plants on the top of high-tech industrial chain hire many packaging workers to carry out miscellaneous packing tasks for various product orders from different companies and countries. Under tremendous workload the quality of life (QoL) of such packaging workers need to be concerned. The aim of this study was to explore factors influencing their QoL. This study recruited 247 packing workers (162 male and 85 female; mean age: 35.6 years old) in 2015 and 2016 from a semiconductor plant in Taiwan by convenience sampling. The questionnaire comprised four parts: demographics, the World Health Organization Quality of Life (WHOQOL-BREF), an occupational burnout inventory and the Nordic Musculoskeletal Questionnaire. The four domains of the WHOQOL-BREF were defined as outcome variables. Predictive factors included gender (reference: male), age (reference: ≤ 35), BMI (reference: ≤ 25), educational level (reference: below university), marital/partner status (reference: married/cohabiting), years of work (reference: ≤ 5), work shift (reference: day shift), personal burnout, work-related burnout, over-commitment to work and the number of body parts with discomfort (0-9). The findings showed that physical QoL was negatively correlated with night -shift work, personal burnout, and number of body parts with discomfort. Psychological QoL was negatively correlated with night shift work and personal burnout. Environment QoL was negatively correlated with being male, night shift work and personal burnout. The results showed that the QoL among the packaging workers could be improved by reducing musculoskeletal discomfort, personal burnout and by improving work schedules.

Analysis of the orbit distortion by the use of the wavelet transform

NASA Astrophysics Data System (ADS)

Matsushita, T.; Agui, A.; Yoshigoe, A.; Takao, M.; Aoyagi, H.; Takeuchi, M.; Nakatani, T.; Tanaka, H.

2004-05-01

We have adopted matching pursuit algorithm of discrete wavelet transform (DWT) for the analysis of the beam position shift correlated with the motion of insertion device(ID). The beam position data measured by the rf beam position monitors have included high-frequency `noises' and fluctuation of background level. Precise evaluation of the electron beam position shift correlated with the motion of the ID is required for estimation of the steering magnet currents in order to suppress the closed orbit distortion (COD). The DWT is a powerful tool for frequency analysis and data processing. The analysis of DWT was applied to the beam position shift correlated with the phase motion of APPLE-2 type undulator (ID23) in SPring-8. The result of the analysis indicated that `noises' are mainly composed of the components of 50 ˜ 6.25Hz and < 0.1Hz. We carried out the data processing to remove the `noises' by the matching pursuit algorithm. Then we have succeeded in suppressing the COD within 2 μm by the use of the steering magnet currents calculated from the processed data.

(13)C NMR substituent-induced chemical shifts in 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-ones (thiones).

PubMed

Kara, Yesim Saniye

2015-01-01

In the present, study mostly novel ten 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-ones and ten 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-thiones were synthesized. These oxadiazole derivatives were characterized by IR, (1)H NMR, (13)C NMR and elemental analyses. Their (13)C NMR spectra were measured in Deuterochloroform (CDCl3). The correlation analysis for the substituent-induced chemical shift (SCS) with Hammett substituent constants (σ), Brown Okamoto substituent constants (σ(+), σ(-)), inductive substituent constants (σI) and different of resonance substituent constants (σR, σR(o)) were performed using SSP (single substituent parameter), DSP (dual substituent parameter) and DSP-NLR (dual substituent parameter-non-linear resonance) methods, as well as single and multiple regression analysis. Negative ρ values were found for all correlations (reverse substituent effect). The results of all statistical analyses, (13)C NMR chemical shift of CN, CO and CS carbon of oxadiazole rings have shown satisfactory correlation. Copyright © 2015 Elsevier B.V. All rights reserved.

The link between impaired theory of mind and executive function in children with cerebral palsy.

PubMed

Li, Xiaoming; Wang, Kai; Wu, Jianxian; Hong, Yongfeng; Zhao, Jingpu; Feng, Xiaojun; Xu, Mei; Wang, Min; Ndasauka, Yamikani; Zhang, Xiaochu

2014-07-01

The aim of the study was to explore the relationship between theory of mind (ToM) deficits and executive function (EF) impairments in children with cerebral palsy (CP), 42 CP with children and 42 typically developing (TD) children, acting as controls, were assessed on the tasks of ToM (false belief and faux pas) and EF (inhibition, updating and shifting). Results showed that CP children had deficits both in ToM and EF tasks. The correlation analyses showed that two EF components (inhibition and updating) were strongly related to false belief and faux pas in both two groups. We also found correlation between shifting and false belief and faux pas. However, this correlation was only found in TD children and not in children with CP. These findings suggest that children with CP lag behind TD children in both ToM and EF. Further, the results reveal, interestingly, that ToM deficits in CP children might be related to their inhibition and updating impairments, but not to shifting impairments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Factor structure and validation of the Attentional Control Scale.

PubMed

Judah, Matt R; Grant, DeMond M; Mills, Adam C; Lechner, William V

2014-04-01

The Attentional Control Scale (ACS; Derryberry & Reed, 2002) has been used to assess executive control over attention in numerous studies, but no published data have examined the factor structure of the English version. The current studies addressed this need and tested the predictive and convergent validity of the ACS subscales. In Study 1, exploratory factor analysis yielded a two-factor model with Focusing and Shifting subscales. In Study 2, confirmatory factor analysis supported this model and suggested superior fit compared to the factor structure of the Icelandic version (Ólafsson et al., 2011). Study 3 examined correlations between the ACS subscales and measures of working memory, anxiety, and cognitive control. Study 4 examined correlations between the subscales and reaction times on a mixed-antisaccade task, revealing positive correlations for antisaccade performance and prosaccade latency with Focusing scores and between switch trial performance and Shifting scores. Additionally, the findings partially supported unique relationships between Focusing and trait anxiety and between Shifting and depression that have been noted in recent research. Although the results generally support the validity of the ACS, additional research using performance-based tasks is needed.

A centroid model of species distribution with applications to the Carolina wren Thryothorus ludovicianus and house finch Haemorhous mexicanus in the United States

USGS Publications Warehouse

Huang, Qiongyu; Sauer, John R.; Swatantran, Anu; Dubayah, Ralph

2016-01-01

Drastic shifts in species distributions are a cause of concern for ecologists. Such shifts pose great threat to biodiversity especially under unprecedented anthropogenic and natural disturbances. Many studies have documented recent shifts in species distributions. However, most of these studies are limited to regional scales, and do not consider the abundance structure within species ranges. Developing methods to detect systematic changes in species distributions over their full ranges is critical for understanding the impact of changing environments and for successful conservation planning. Here, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. Yearly abundance-weighted range centroids are estimated. As case studies, we derive annual centroids for the Carolina wren and house finch in their ranges in the U.S. We further evaluate the first-difference correlation between species’ centroid movement and changes in winter severity, total population abundance. We also examined associations of change in centroids from sub-ranges. Change in full-range centroid movements of Carolina wren significantly correlate with snow cover days (r = −0.58). For both species, the full-range centroid shifts also have strong correlation with total abundance (r = 0.65, and 0.51 respectively). The movements of the full-range centroids of the two species are correlated strongly (up to r = 0.76) with that of the sub-ranges with more drastic population changes. Our study demonstrates the usefulness of centroids for analyzing distribution changes in a two-dimensional spatial context. Particularly it highlights applications that associate the centroid with factors such as environmental stressors, population characteristics, and progression of invasive species. Routine monitoring of changes in centroid will provide useful insights into long-term avian responses to environmental changes.

Parallel phase-shifting self-interference digital holography with faithful reconstruction using compressive sensing

NASA Astrophysics Data System (ADS)

Wan, Yuhong; Man, Tianlong; Wu, Fan; Kim, Myung K.; Wang, Dayong

2016-11-01

We present a new self-interference digital holographic approach that allows single-shot capturing three-dimensional intensity distribution of the spatially incoherent objects. The Fresnel incoherent correlation holographic microscopy is combined with parallel phase-shifting technique to instantaneously obtain spatially multiplexed phase-shifting holograms. The compressive-sensing-based reconstruction algorithm is implemented to reconstruct the original object from the under sampled demultiplexed holograms. The scheme is verified with simulations. The validity of the proposed method is experimentally demonstrated in an indirectly way by simulating the use of specific parallel phase-shifting recording device.

Soft theorems for shift-symmetric cosmologies

NASA Astrophysics Data System (ADS)

Finelli, Bernardo; Goon, Garrett; Pajer, Enrico; Santoni, Luca

2018-03-01

We derive soft theorems for single-clock cosmologies that enjoy a shift symmetry. These so-called consistency conditions arise from a combination of a large diffeomorphism and the internal shift symmetry and fix the squeezed limit of all correlators with a soft scalar mode. As an application, we show that our results reproduce the squeezed bispectrum for ultra-slow-roll inflation, a particular shift-symmetric, nonattractor model which is known to violate Maldacena's consistency relation. Similar results have been previously obtained by Mooij and Palma using background-wave methods. Our results shed new light on the infrared structure of single-clock cosmological spacetimes.

Dimensions of Attention Associated With the Microstructure of Corona Radiata White Matter.

PubMed

Stave, Elise A; De Bellis, Michael D; Hooper, Steven R; Woolley, Donald P; Chang, Suk Ki; Chen, Steven D

2017-04-01

Mirsky proposed a model of attention that included these dimensions: focus/execute, sustain, stabilize, encode, and shift. The neural correlates of these dimensions were investigated within corona radiata subregions in healthy youth. Diffusion tensor imaging and neuropsychological assessments were conducted in 79 healthy, right-handed youth aged 4-17 years. Diffusion tensor imaging maps were analyzed using standardized parcellation methods. Partial Pearson correlations between neuropsychological standardized scores, representing these attention dimensions, and diffusion tensor imaging measures of corona radiata subregions were calculated after adjusting for gender and IQ. Significant correlations were found between the focus/execute, sustain, stabilize, and shift dimensions and imaging metrics in hypothesized corona radiata subregions. Results suggest that greater microstructural white matter integrity of the corona radiata is partly associated with attention across 4 attention dimensions. Findings suggest that white matter microstructure of the corona radiata is a neural correlate of several, but not all, attention dimensions.

Dimensions of Attention Associated with the Microstructure of Corona Radiata White Matter

PubMed Central

Stave, Elise A.; Hooper, Stephen R.; Woolley, Donald P.; Chang, Suk Ki; Chen, Steven D.

2016-01-01

Mirsky proposed a model of attention that included these dimensions: focus/execute, sustain, stabilize, encode, and shift. The neural correlates of these dimensions were investigated within corona radiate subregions in healthy youth. Diffusion tensor imaging and neuropsychological assessments were conducted in 79 healthy, right-handed youth aged 4–17 years. Diffusion tensor imaging maps were analyzed using standardized parcellation methods. Partial Pearson correlations between neuropsychological standardized scores, representing these attention dimensions, and diffusion tensor imaging measures of corona radiate subregions were calculated after adjusting for gender and IQ. Significant correlations were found between the focus/execute, sustain, stabilize and shift dimensions and imaging metrics in hypothesized corona radiate subregions. Results suggest that greater microstructural white matter integrity of the corona radiata is partly associated with attention across four attention dimensions. Findings suggest that white matter microstructure of the corona radiata is a neural correlate of several, but not all, attention dimensions. PMID:28090797

Consistently Sampled Correlation Filters with Space Anisotropic Regularization for Visual Tracking

PubMed Central

Shi, Guokai; Xu, Tingfa; Luo, Jiqiang; Li, Yuankun

2017-01-01

Most existing correlation filter-based tracking algorithms, which use fixed patches and cyclic shifts as training and detection measures, assume that the training samples are reliable and ignore the inconsistencies between training samples and detection samples. We propose to construct and study a consistently sampled correlation filter with space anisotropic regularization (CSSAR) to solve these two problems simultaneously. Our approach constructs a spatiotemporally consistent sample strategy to alleviate the redundancies in training samples caused by the cyclical shifts, eliminate the inconsistencies between training samples and detection samples, and introduce space anisotropic regularization to constrain the correlation filter for alleviating drift caused by occlusion. Moreover, an optimization strategy based on the Gauss-Seidel method was developed for obtaining robust and efficient online learning. Both qualitative and quantitative evaluations demonstrate that our tracker outperforms state-of-the-art trackers in object tracking benchmarks (OTBs). PMID:29231876

Set-shifting and its relation to clinical and personality variables in full recovery of anorexia nervosa.

PubMed

Lindner, Susanne E; Fichter, Manfred M; Quadflieg, Norbert

2014-07-01

First, this study aimed to explore whether set-shifting is inefficient after full recovery of anorexia nervosa (recAN). Second, this study wanted to explore the relation of set-shifting to clinical and personality variables. A total of 100 recAN women were compared with 100 healthy women. Set-shifting was assessed with Berg's Card Sorting Test. Expert interviews yielded assessments for the inclusion/exclusion criteria, self-ratings for clinical and personality variables. Compared with the healthy control group, the recAN participants achieved fewer categories, showed more perseverations and spent less time for shifting set. Perfectionism is correlated with set-shifting but in converse directions in the two groups. Our study supports the findings of inefficiencies in set-shifting after full recovery from AN. Higher perfectionism in the recAN group is associated with better set-shifting ability, whereas higher perfectionism in the healthy control group is related to worse set-shifting ability. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.

Toward structural dynamics: protein motions viewed by chemical shift modulations and direct detection of C'N multiple-quantum relaxation.

PubMed

Mori, Mirko; Kateb, Fatiha; Bodenhausen, Geoffrey; Piccioli, Mario; Abergel, Daniel

2010-03-17

Multiple quantum relaxation in proteins reveals unexpected relationships between correlated or anti-correlated conformational backbone dynamics in alpha-helices or beta-sheets. The contributions of conformational exchange to the relaxation rates of C'N coherences (i.e., double- and zero-quantum coherences involving backbone carbonyl (13)C' and neighboring amide (15)N nuclei) depend on the kinetics of slow exchange processes, as well as on the populations of the conformations and chemical shift differences of (13)C' and (15)N nuclei. The relaxation rates of C'N coherences, which reflect concerted fluctuations due to slow chemical shift modulations (CSMs), were determined by direct (13)C detection in diamagnetic and paramagnetic proteins. In well-folded proteins such as lanthanide-substituted calbindin (CaLnCb), copper,zinc superoxide dismutase (Cu,Zn SOD), and matrix metalloproteinase (MMP12), slow conformational exchange occurs along the entire backbone. Our observations demonstrate that relaxation rates of C'N coherences arising from slow backbone dynamics have positive signs (characteristic of correlated fluctuations) in beta-sheets and negative signs (characteristic of anti-correlated fluctuations) in alpha-helices. This extends the prospects of structure-dynamics relationships to slow time scales that are relevant for protein function and enzymatic activity.

VITAL NMR: Using Chemical Shift Derived Secondary Structure Information for a Limited Set of Amino Acids to Assess Homology Model Accuracy

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

Brothers, Michael C; Nesbitt, Anna E; Hallock, Michael J

2011-01-01

Homology modeling is a powerful tool for predicting protein structures, whose success depends on obtaining a reasonable alignment between a given structural template and the protein sequence being analyzed. In order to leverage greater predictive power for proteins with few structural templates, we have developed a method to rank homology models based upon their compliance to secondary structure derived from experimental solid-state NMR (SSNMR) data. Such data is obtainable in a rapid manner by simple SSNMR experiments (e.g., (13)C-(13)C 2D correlation spectra). To test our homology model scoring procedure for various amino acid labeling schemes, we generated a library ofmore » 7,474 homology models for 22 protein targets culled from the TALOS+/SPARTA+ training set of protein structures. Using subsets of amino acids that are plausibly assigned by SSNMR, we discovered that pairs of the residues Val, Ile, Thr, Ala and Leu (VITAL) emulate an ideal dataset where all residues are site specifically assigned. Scoring the models with a predicted VITAL site-specific dataset and calculating secondary structure with the Chemical Shift Index resulted in a Pearson correlation coefficient (-0.75) commensurate to the control (-0.77), where secondary structure was scored site specifically for all amino acids (ALL 20) using STRIDE. This method promises to accelerate structure procurement by SSNMR for proteins with unknown folds through guiding the selection of remotely homologous protein templates and assessing model quality.« less

Cognitive impact of social stress and coping strategy throughout development.

PubMed

Snyder, Kevin P; Barry, Mark; Valentino, Rita J

2015-01-01

Stress experience during adolescence has been linked to the development of psychiatric disorders in adulthood, many of which are associated with impairments in prefrontal cortex function. The current study was designed to determine the immediate and enduring effects of repeated social stress on a prefrontal cortex-dependent cognitive task. Early adolescent (P28), mid-adolescent (P42), and adult (P70) rats were exposed to resident-intruder stress for 5 days and tested in an operant strategy-shifting task (OSST) during the following week or several weeks later during adulthood. Engagement of prefrontal cortical neurons during the task was assessed by expression of the immediate early gene, c-fos. Social stress during adolescence had no immediate effects on task performance, but impaired strategy-shifting in adulthood, whereas social stress that occurred during adulthood had no effect. The cognitive impairment produced by adolescent social stress was most pronounced in rats with a passive coping strategy. Notably, strategy-shifting performance was positively correlated with medial prefrontal cortical c-fos in adulthood but not in adolescence, suggesting that the task engages different brain regions in adolescents compared to adults. Adolescent social stress produces a protracted impairment in prefrontal cortex-mediated cognition that is related to coping strategy. This impairment may be selectively expressed in adulthood because prefrontal cortical activity is integral to task performance at this age but not during adolescence.

The fine structure of Langmuir waves observed upstream of the bow shock at Venus

NASA Technical Reports Server (NTRS)

Hospodarsky, G. B.; Gurnett, D. A.; Kurth, W. S.; Kivelson, M. G.; Strangeway, R. J.; Bolton, S. J.

1994-01-01

Highly structured Langmuir waves, also known as electron plasma oscillations, have been observed in the foreshock of Venus using the plasma wave experiment on the Galileo spacecraft during the gravity assist flyby on February 10, 1990. The Galileo wideband sampling system provides digital electric field waveform measurements at sampling rates up to 201,600 samples per second, much higher than any previous instrument of this type. The main Langmuir wave emission band occurs near the local electron plasma frequency, which was approximately 43 kHz. The Langmuir waves are observed to shift above and below the plasma frequency, sometimes by as much as 20 kHz. The shifts in frequency are closely correlated with the downstream distance from the tangent field line, implying that the shifts are controlled by the electron beam velocity. Considerable fine structure is also evident, with time scales as short as 0.15 milliseconds, corresponding to spatial scales of a few tens of Debye lengths. The frequency spectrum often consists of beat-type waveforms, with beat frequencies ranging from 0.2 to 7 kHz, and in a few cases, isolated wavepackets. The peak electric field strengths are approximately 1 mV/m. These field strengths are too small for strongly nonlinear processes to be important. The beat-type waveforms are suggestive of a parametric decay process.

Application of electrochemically deposited nanostructured ZnO layers on quartz crystal microbalance for NO2 detection

NASA Astrophysics Data System (ADS)

Georgieva, B.; Petrov, M.; Lovchinov, K.; Ganchev, M.; Georgieva, V.; Dimova-Malinovska, D.

2014-11-01

The research was fixed on sensing behavior of ZnO nanostructured (NS) films to NO2 concentrations in the environment. The ZnO NS layers are deposited by electrochemical method on quartz resonators with Au electrodes. The sorption properties of ZnO layers were defined by measuring the resonant frequency shift (Δf) of the QCM-ZnO structure for different NO2 concentrations. The measurements were based on the correlation between the frequency shift of the QCM and additional mass loading (Δm) on the resonator calculated using Sauerbrey equation for the AT-cut quartz plate. Frequency - Time Characteristics (FTCs) of the samples were measured as a function of different NO2 concentrations in order to define the sorption abilities of ZnO layers. The experiments were carried out on a special set up in a dynamical regime. From FTCs the response and the recovery times of the QCM-ZnO structure were measured with varying NO2. Frequency shift changed from 23 Hz to 58Hz when NO2 was varied in the range of 250ppm - 5000ppm. The process of sorption was estimated as reversible and the sorption as physical. The obtained results demonstrated that QCM covered with the electrochemically deposited nanostructured ZnO films can be used as application in NO2 sensors.

[The prevalence of low back pain in hospital staff and its relationship with chronic fatigue syndrome and occupational factors].

PubMed

Terzi, Rabia; Altın, Firuzan

2015-01-01

This study aimed to investigate the occurrence of low back pain in hospital employees during the previous year and its correlation with demographic data, occupational factors and chronic fatigue syndrome. All participants provided information on their socio-demographic background, occupational characteristics, their experience of low back pain during the previous year, and chronic fatigue syndrome. The study included 365 volunteers (221 male and 144 female). The mean age was 33.1 ± 7.2. Of the 365 participants, 218 (59.7%) had experienced low back pain in the last year. No statistically significant difference was detected in age, height, weight, level of education, smoking habits, occupation, professional working hours, shift work or levels of income between the groups with and without low back pain. Low back pain was more frequent (p<0.05) in male workers. Chronic fatigue syndrome was statistically significant in the group suffering from low back pain (p<0.05), of whom 21.5% had chronic fatigue syndrome. We detected a statistically significant relationship (p<0.05) between chronic fatigue syndrome, occupational duration and shift work. To the best of our knowledge, this is the first to show the relationship between low back pain and chronic fatigue syndrome in hospital employees. Shift work and length of time in occupation are risk factors for chronic fatigue syndrome.

Three model space experiments on chemical reactions. [Gibbs adsorption, equilibrium shift and electrodeposition

NASA Technical Reports Server (NTRS)

Grodzka, P.; Facemire, B.

1977-01-01

Three investigations conducted aboard Skylab IV and Apollo-Soyuz involved phenomena that are of interest to the biochemistry community. The formaldehyde clock reaction and the equilibrium shift reaction experiments conducted aboard Apollo Soyuz demonstrate the effect of low-g foams or air/liquid dispersions on reaction rate and chemical equilibrium. The electrodeposition reaction experiment conducted aboard Skylab IV demonstrate the effect of a low-g environment on an electrochemical displacement reaction. The implications of the three space experiments for various applications are considered.

Hormonal, behavioral, and life-history traits exhibit correlated shifts in relation to population establishment in a novel environment.

PubMed

Atwell, Jonathan W; Cardoso, Gonçalo C; Whittaker, Danielle J; Price, Trevor D; Ketterson, Ellen D

2014-12-01

Climate change, habitat alteration, range expansions, and biological invasions are all predicted to require rapid shifts in multiple traits including behavior and life history, both for initial population establishment and subsequent adaptation. Hormonal mechanisms likely play a key role in facilitating or constraining plastic and genetic responses for suites of traits, but few studies have evaluated their role in shaping contemporary adaptation or diversification. We examined multiple phenotypic adjustments and associated hormonal changes following a recent (early 1980s) colonization event, in which a temperate-breeding songbird, the dark-eyed junco (Junco hyemalis), became established in the Mediterranean climate of San Diego, California. The milder climate has led to an extended breeding season and year-round residency, and we document shifts in multiple sexually selected behaviors and plumage traits. Testosterone titers in San Diego were elevated for longer but with a lower peak value compared to a nearby native-range population, and correlations between testosterone and related traits were similar within and among populations. A common garden study indicated that changes in testosterone likely represent plastic responses to the less seasonal environment of the city, providing the context against which subsequent genetic changes in morphology likely occurred. We argue that correlated shifts in multiple traits, organized by underlying physiology, may be a generally important element of many successful adjustments to changing environments.

Algorithms for calculating mass-velocity and Darwin relativistic corrections with n-electron explicitly correlated Gaussians with shifted centers

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

Stanke, Monika, E-mail: monika@fizyka.umk.pl; Palikot, Ewa, E-mail: epalikot@doktorant.umk.pl; Adamowicz, Ludwik, E-mail: ludwik@email.arizona.edu

2016-05-07

Algorithms for calculating the leading mass-velocity (MV) and Darwin (D) relativistic corrections are derived for electronic wave functions expanded in terms of n-electron explicitly correlated Gaussian functions with shifted centers and without pre-exponential angular factors. The algorithms are implemented and tested in calculations of MV and D corrections for several points on the ground-state potential energy curves of the H{sub 2} and LiH molecules. The algorithms are general and can be applied in calculations of systems with an arbitrary number of electrons.

Characterization of Silicon Nanocrystal Surfaces by Multidimensional Solid-State NMR Spectroscopy

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

Hanrahan, Michael P.; Fought, Ellie L.; Windus, Theresa L.

The chemical and photophysical properties of silicon nanocrystals (Si NCs) are strongly dependent on the chemical composition and structure of their surfaces. Here we use fast magic angle spinning (MAS) and proton detection to enable the rapid acquisition of dipolar and scalar 2D 1H– 29Si heteronuclear correlation (HETCOR) solid-state NMR spectra and reveal a molecular picture of hydride-terminated and alkyl-functionalized surfaces of Si NCs produced in a nonthermal plasma. 2D 1H– 29Si HETCOR and dipolar 2D 1H– 1H multiple-quantum correlation spectra illustrate that resonances from surface mono-, di-, and trihydride groups cannot be resolved, contrary to previous literature assignments. Insteadmore » the 2D NMR spectra illustrate that there is large distribution of 1H and 29Si chemical shifts for the surface hydride species in both the as-synthesized and functionalized Si NCs. However, proton-detected 1H– 29Si refocused INEPT experiments can be used to unambiguously differentiate NMR signals from the different surface hydrides. Varying the 29Si evolution time in refocused INEPT experiments and fitting the oscillation of the NMR signals allows for the relative populations of the different surface hydrides to be estimated. This analysis confirms that monohydride species are the predominant surface species on the as-synthesized Si NCs. A reduction in the populations of the di- and trihydrides is observed upon functionalization with alkyl groups, consistent with our previous hypothesis that the trihydride, or silyl (*SiH 3), group is primarily responsible for initiating surface functionalization reactions. Density functional theory (DFT) calculations were used to obtain quantum chemical structural models of the Si NC surface and reproduce the observed 1H and 29Si chemical shifts. Furthermore, the approaches outlined here will be useful to obtain a more detailed picture of surface structures for Si NCs and other hydride-passivated nanomaterials.« less

Characterization of Silicon Nanocrystal Surfaces by Multidimensional Solid-State NMR Spectroscopy

DOE PAGES

Hanrahan, Michael P.; Fought, Ellie L.; Windus, Theresa L.; ...

2017-11-22

The chemical and photophysical properties of silicon nanocrystals (Si NCs) are strongly dependent on the chemical composition and structure of their surfaces. Here we use fast magic angle spinning (MAS) and proton detection to enable the rapid acquisition of dipolar and scalar 2D 1H– 29Si heteronuclear correlation (HETCOR) solid-state NMR spectra and reveal a molecular picture of hydride-terminated and alkyl-functionalized surfaces of Si NCs produced in a nonthermal plasma. 2D 1H– 29Si HETCOR and dipolar 2D 1H– 1H multiple-quantum correlation spectra illustrate that resonances from surface mono-, di-, and trihydride groups cannot be resolved, contrary to previous literature assignments. Insteadmore » the 2D NMR spectra illustrate that there is large distribution of 1H and 29Si chemical shifts for the surface hydride species in both the as-synthesized and functionalized Si NCs. However, proton-detected 1H– 29Si refocused INEPT experiments can be used to unambiguously differentiate NMR signals from the different surface hydrides. Varying the 29Si evolution time in refocused INEPT experiments and fitting the oscillation of the NMR signals allows for the relative populations of the different surface hydrides to be estimated. This analysis confirms that monohydride species are the predominant surface species on the as-synthesized Si NCs. A reduction in the populations of the di- and trihydrides is observed upon functionalization with alkyl groups, consistent with our previous hypothesis that the trihydride, or silyl (*SiH 3), group is primarily responsible for initiating surface functionalization reactions. Density functional theory (DFT) calculations were used to obtain quantum chemical structural models of the Si NC surface and reproduce the observed 1H and 29Si chemical shifts. Furthermore, the approaches outlined here will be useful to obtain a more detailed picture of surface structures for Si NCs and other hydride-passivated nanomaterials.« less

Entry-Level Technical Skills that Agricultural Industry Experts Expected Students to Learn through Their Supervised Agricultural Experiences: A Modified Delphi Study

ERIC Educational Resources Information Center

Ramsey, Jon W.; Edwards, M. Craig

2011-01-01

The National Research Council's (NRC) Report (1988), Understanding Agriculture: New Directions for Education, called on secondary agricultural education to shift its scope and purpose, including students' supervised agricultural experiences (SAEs). The NRC asserted that this shift should create opportunities for students to acquire supervised…

Regional Homogeneity Predicts Creative Insight: A Resting-State fMRI Study.

PubMed

Lin, Jiabao; Cui, Xuan; Dai, Xiaoying; Mo, Lei

2018-01-01

Creative insight plays an important role in our daily life. Previous studies have investigated the neural correlates of creative insight by functional magnetic resonance imaging (fMRI), however, the intrinsic resting-state brain activity associated with creative insight is still unclear. In the present study, we used regional homogeneity (ReHo) as an index in resting-state fMRI (rs-fMRI) to identify brain regions involved in individual differences in creative insight, which was compued by the response time (RT) of creative Chinese character chunk decomposition. The findings indicated that ReHo in the anterior cingulate cortex (ACC)/caudate nucleus (CN) and angular gyrus (AG)/superior temporal gyrus (STG)/inferior parietal lobe (IPL) negatively predicted creative insight. Furthermore, these findings suggested that spontaneous brain activity in multiple regions related to breaking and establishing mental sets, goal-directed solutions exploring, shifting attention, forming new associations and emotion experience contributes to creative insight. In conclusion, the present study provides new evidence to further understand the cognitive processing and neural correlates of creative insight.

Signatures of four-particle correlations associated with exciton-carrier interactions in coherent spectroscopy on bulk GaAs

NASA Astrophysics Data System (ADS)

Webber, D.; Wilmer, B. L.; Liu, X.; Dobrowolska, M.; Furdyna, J. K.; Bristow, A. D.; Hall, K. C.

2016-10-01

Transient four-wave mixing studies of bulk GaAs under conditions of broad bandwidth excitation of primarily interband transitions have enabled four-particle correlations tied to degenerate (exciton-exciton) and nondegenerate (exciton-carrier) interactions to be studied. Real two-dimensional Fourier-transform spectroscopy (2DFTS) spectra reveal a complex response at the heavy-hole exciton emission energy that varies with the absorption energy, ranging from dispersive on the diagonal through absorptive for low-energy interband transitions to dispersive with the opposite sign for interband transitions high above band gap. Simulations using a multilevel model augmented by many-body effects provide excellent agreement with the 2DFTS experiments and indicate that excitation-induced dephasing (EID) and excitation-induced shift (EIS) affect degenerate and nondegenerate interactions equivalently, with stronger exciton-carrier coupling relative to exciton-exciton coupling by approximately an order of magnitude. These simulations also indicate that EID effects are three times stronger than EIS in contributing to the coherent response of the semiconductor.

Détermination assistée par ordinateur de la structure des molécules organiques

NASA Astrophysics Data System (ADS)

Nuzillard, J.-M.

1998-02-01

Nuclear Magnetic Resonance spectroscopy offers the unique possibility of accessing proximity relationships between atoms by means of chemical shift correlation experiments. Structure determination of small molecules has become thus much simpler. Computer programs can use directly correlation information for structure analysis. The use and operation mechanism of such a program, LSD (Logic for Structure Determination) are presented. The example compound is gibberellic acid, a natural product. La spectroscopie de Résonance Magnétique Nucléaire offre un moyen unique de déterminer des relations de proximité entre atomes par le biais des expériences de corrélation. L'analyse structurale de petites molécules organiques s'en trouve extrêmement facilitée. Des programmes informatiques peuvent utiliser directement les informations de corrélation pour déduire des structures. Le fonctionnement et l'usage d'un tel programme, LSD (Logic for Structure Determination), sont détaillés sur un exemple, l'acide gibberellique.

Short-term Memory as a Processing Shift

ERIC Educational Resources Information Center

Lewis-Smith, Marion Quinn

1975-01-01

The series of experiments described here examined the predictions for free recall from sequential models and the shift formulation, focusing on the roles of short- and long-term memory in the primacy/recency shift and on the effects of expectancies on short- and long-term memory. (Author/RK)

Spatial problem-solving strategies of middle school students: Wayfinding with geographic information systems

NASA Astrophysics Data System (ADS)

Wigglesworth, John C.

2000-06-01

Geographic Information Systems (GIS) is a powerful computer software package that emphasizes the use of maps and the management of spatially referenced environmental data archived in a systems data base. Professional applications of GIS have been in place since the 1980's, but only recently has GIS gained significant attention in the K--12 classroom. Students using GIS are able to manipulate and query data in order to solve all manners of spatial problems. Very few studies have examined how this technological innovation can support classroom learning. In particular, there has been little research on how experience in using the software correlates with a child's spatial cognition and his/her ability to understand spatial relationships. This study investigates the strategies used by middle school students to solve a wayfinding (route-finding) problem using the ArcView GIS software. The research design combined an individual background questionnaire, results from the Group Assessment of Logical Thinking (GALT) test, and analysis of reflective think-aloud sessions to define the characteristics of the strategies students' used to solve this particular class of spatial problem. Three uniquely different spatial problem solving strategies were identified. Visual/Concrete Wayfinders used a highly visual strategy; Logical/Abstract Wayfinders used GIS software tools to apply a more analytical and systematic approach; Transitional Wayfinders used an approach that showed evidence of one that was shifting from a visual strategy to one that was more analytical. The triangulation of data sources indicates that this progression of wayfinding strategy can be correlated both to Piagetian stages of logical thought and to experience with the use of maps. These findings suggest that GIS teachers must be aware that their students' performance will lie on a continuum that is based on cognitive development, spatial ability, and prior experience with maps. To be most effective, GIS teaching strategies and curriculum development should also represent a progression that correlates to the learners' current skills and experience.

GPs' experiences with out-of-hours GP cooperatives: a survey study from the Netherlands.

PubMed

Smits, Marleen; Keizer, Ellen; Huibers, Linda; Giesen, Paul

2014-09-01

Out-of-hours primary care has been provided by general practitioner (GP) cooperatives since the year 2000 in the Netherlands. Early studies in countries with similar organizational structures showed positive GP experiences. However, nowadays it is said that GPs experience a high workload at the cooperative and that they outsource a considerable part of their shifts. To examine positive and negative experiences of GPs providing out-of-hours primary care, and the frequency and reasons for outsourcing shifts. A cross-sectional observational survey among 688 GPs connected to six GP cooperatives in the Netherlands, using a web-based questionnaire. The response was 55% (n = 378). The main reasons for working in GP cooperatives were to retain registration as GP (79%) and remain experienced in acute care (74%). GPs considered the peak hours (81%) and the high number of patients (73%) as the most negative aspects. Most GPs chose to provide the out-of-hours shifts themselves: 85% outsourced maximally 25% of their shifts. The percentage of outsourced shifts increased with age. Main reasons for outsourcing were the desire to have more private time (76%); the high workload in daytime practice (71%); and less the workload during out-of-hours (46%). GPs are motivated to work in out-of-hours GP cooperatives, and they outsource few shifts. GPs consider the peak load and the large number of (non-urgent) help requests as the most negative aspects. To motivate and involve GPs for 7 × 24-h primary care, it is important to set limits on their workload.

Temporal recalibration of motor and visual potentials in lag adaptation in voluntary movement.

PubMed

Cai, Chang; Ogawa, Kenji; Kochiyama, Takanori; Tanaka, Hirokazu; Imamizu, Hiroshi

2018-05-15

Adaptively recalibrating motor-sensory asynchrony is critical for animals to perceive self-produced action consequences. It is controversial whether motor- or sensory-related neural circuits recalibrate this asynchrony. By combining magnetoencephalography (MEG) and functional MRI (fMRI), we investigate the temporal changes in brain activities caused by repeated exposure to a 150-ms delay inserted between a button-press action and a subsequent flash. We found that readiness potentials significantly shift later in the motor system, especially in parietal regions (average: 219.9 ms), while visually evoked potentials significantly shift earlier in occipital regions (average: 49.7 ms) in the delay condition compared to the no-delay condition. Moreover, the shift in readiness potentials, but not in visually evoked potentials, was significantly correlated with the psychophysical measure of motor-sensory adaptation. These results suggest that although both motor and sensory processes contribute to the recalibration, the motor process plays the major role, given the magnitudes of shift and the correlation with the psychophysical measure. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Estimation of Cyclic Shift with Delayed Correlation and Matched Filtering in Time Domain Cyclic-SLM for PAPR Reduction

PubMed Central

2016-01-01

Time domain cyclic-selective mapping (TDC-SLM) reduces the peak-to-average power ratio (PAPR) in OFDM systems while the amounts of cyclic shifts are required to recover the transmitted signal in a receiver. One of the critical issues of the SLM scheme is sending the side information (SI) which reduces the throughputs in wireless OFDM systems. The proposed scheme implements delayed correlation and matched filtering (DC-MF) to estimate the amounts of the cyclic shifts in the receiver. In the proposed scheme, the DC-MF is placed after the frequency domain equalization (FDE) to improve the accuracy of cyclic shift estimation. The accuracy rate of the propose scheme reaches 100% at E b/N 0 = 5 dB and the bit error rate (BER) improves by 0.2 dB as compared with the conventional TDC-SLM. The BER performance of the proposed scheme is also better than that of the conventional TDC-SLM even though a nonlinear high power amplifier is assumed. PMID:27752539

Efficient Solar Scene Wavefront Estimation with Reduced Systematic and RMS Errors: Summary

NASA Astrophysics Data System (ADS)

Anugu, N.; Garcia, P.

2016-04-01

Wave front sensing for solar telescopes is commonly implemented with the Shack-Hartmann sensors. Correlation algorithms are usually used to estimate the extended scene Shack-Hartmann sub-aperture image shifts or slopes. The image shift is computed by correlating a reference sub-aperture image with the target distorted sub-aperture image. The pixel position where the maximum correlation is located gives the image shift in integer pixel coordinates. Sub-pixel precision image shifts are computed by applying a peak-finding algorithm to the correlation peak Poyneer (2003); Löfdahl (2010). However, the peak-finding algorithm results are usually biased towards the integer pixels, these errors are called as systematic bias errors Sjödahl (1994). These errors are caused due to the low pixel sampling of the images. The amplitude of these errors depends on the type of correlation algorithm and the type of peak-finding algorithm being used. To study the systematic errors in detail, solar sub-aperture synthetic images are constructed by using a Swedish Solar Telescope solar granulation image1. The performance of cross-correlation algorithm in combination with different peak-finding algorithms is investigated. The studied peak-finding algorithms are: parabola Poyneer (2003); quadratic polynomial Löfdahl (2010); threshold center of gravity Bailey (2003); Gaussian Nobach & Honkanen (2005) and Pyramid Bailey (2003). The systematic error study reveals that that the pyramid fit is the most robust to pixel locking effects. The RMS error analysis study reveals that the threshold centre of gravity behaves better in low SNR, although the systematic errors in the measurement are large. It is found that no algorithm is best for both the systematic and the RMS error reduction. To overcome the above problem, a new solution is proposed. In this solution, the image sampling is increased prior to the actual correlation matching. The method is realized in two steps to improve its computational efficiency. In the first step, the cross-correlation is implemented at the original image spatial resolution grid (1 pixel). In the second step, the cross-correlation is performed using a sub-pixel level grid by limiting the field of search to 4 × 4 pixels centered at the first step delivered initial position. The generation of these sub-pixel grid based region of interest images is achieved with the bi-cubic interpolation. The correlation matching with sub-pixel grid technique was previously reported in electronic speckle photography Sjö'dahl (1994). This technique is applied here for the solar wavefront sensing. A large dynamic range and a better accuracy in the measurements are achieved with the combination of the original pixel grid based correlation matching in a large field of view and a sub-pixel interpolated image grid based correlation matching within a small field of view. The results revealed that the proposed method outperforms all the different peak-finding algorithms studied in the first approach. It reduces both the systematic error and the RMS error by a factor of 5 (i.e., 75% systematic error reduction), when 5 times improved image sampling was used. This measurement is achieved at the expense of twice the computational cost. With the 5 times improved image sampling, the wave front accuracy is increased by a factor of 5. The proposed solution is strongly recommended for wave front sensing in the solar telescopes, particularly, for measuring large dynamic image shifts involved open loop adaptive optics. Also, by choosing an appropriate increment of image sampling in trade-off between the computational speed limitation and the aimed sub-pixel image shift accuracy, it can be employed in closed loop adaptive optics. The study is extended to three other class of sub-aperture images (a point source; a laser guide star; a Galactic Center extended scene). The results are planned to submit for the Optical Express journal.

Mechanisms of action of (meth)acrylates in hemolytic activity, in vivo toxicity and dipalmitoylphosphatidylcholine (DPPC) liposomes determined using NMR spectroscopy.

PubMed

Fujisawa, Seiichiro; Kadoma, Yoshinori

2012-01-01

We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H(50)) or in vivo mouse intraperitoneal (ip) LD(50) using reported data for α,β-unsaturated carbonyl compounds such as (meth)acrylate monomers and their (13)C-NMR β-carbon chemical shift (δ). The log 1/H(50) value for methacrylates was linearly correlated with the δC(β) value. That for (meth)acrylates was linearly correlated with log P, an index of lipophilicity. The ipLD(50) for (meth)acrylates was linearly correlated with δC(β) but not with log P. For (meth)acrylates, the δC(β) value, which is dependent on the π-electron density on the β-carbon, was linearly correlated with PM3-based theoretical parameters (chemical hardness, η; electronegativity, χ; electrophilicity, ω), whereas log P was linearly correlated with heat of formation (HF). Also, the interaction between (meth)acrylates and DPPC liposomes in cell membrane molecular models was investigated using (1)H-NMR spectroscopy and differential scanning calorimetry (DSC). The log 1/H(50) value was related to the difference in chemical shift (ΔδHa) (Ha: H (trans) attached to the β-carbon) between the free monomer and the DPPC liposome-bound monomer. Monomer-induced DSC phase transition properties were related to HF for monomers. NMR chemical shifts may represent a valuable parameter for investigating the biological mechanisms of action of (meth)acrylates.

Mechanisms of Action of (Meth)acrylates in Hemolytic Activity, in Vivo Toxicity and Dipalmitoylphosphatidylcholine (DPPC) Liposomes Determined Using NMR Spectroscopy

PubMed Central

Fujisawa, Seiichiro; Kadoma, Yoshinori

2012-01-01

We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H50) or in vivo mouse intraperitoneal (ip) LD50 using reported data for α,β-unsaturated carbonyl compounds such as (meth)acrylate monomers and their 13C-NMR β-carbon chemical shift (δ). The log 1/H50 value for methacrylates was linearly correlated with the δCβ value. That for (meth)acrylates was linearly correlated with log P, an index of lipophilicity. The ipLD50 for (meth)acrylates was linearly correlated with δCβ but not with log P. For (meth)acrylates, the δCβ value, which is dependent on the π-electron density on the β-carbon, was linearly correlated with PM3-based theoretical parameters (chemical hardness, η; electronegativity, χ; electrophilicity, ω), whereas log P was linearly correlated with heat of formation (HF). Also, the interaction between (meth)acrylates and DPPC liposomes in cell membrane molecular models was investigated using 1H-NMR spectroscopy and differential scanning calorimetry (DSC). The log 1/H50 value was related to the difference in chemical shift (ΔδHa) (Ha: H (trans) attached to the β-carbon) between the free monomer and the DPPC liposome-bound monomer. Monomer-induced DSC phase transition properties were related to HF for monomers. NMR chemical shifts may represent a valuable parameter for investigating the biological mechanisms of action of (meth)acrylates. PMID:22312284

Correlation of MFOLD-predicted DNA secondary structures with separation patterns obtained by capillary electrophoresis single-strand conformation polymorphism (CE-SSCP) analysis.

PubMed

Glavac, Damjan; Potocnik, Uros; Podpecnik, Darja; Zizek, Teofil; Smerkolj, Sava; Ravnik-Glavac, Metka

2002-04-01

We have studied 57 different mutations within three beta-globin gene promoter fragments with sizes 52 bp, 77 bp, and 193 bp by fluorescent capillary electrophoresis CE-SSCP analysis. For each mutation and wild type, energetically most-favorable predicted secondary structures were calculated for sense and antisense strands using the MFOLD DNA-folding algorithm in order to investigate if any correlation exists between predicted DNA structures and actual CE migration time shifts. The overall CE-SSCP detection rate was 100% for all mutations in three studied DNA fragments. For shorter 52 bp and 77 bp DNA fragments we obtained a positive correlation between the migration time shifts and difference in free energy values of predicted secondary structures at all temperatures. For longer 193 bp beta-globin gene fragments with 46 mutations MFOLD predicted different secondary structures for 89% of mutated strands at 25 degrees C and 40 degrees C. However, the magnitude of the mobility shifts did not necessarily correlate with their secondary structures and free energy values except for the sense strand at 40 degrees C where this correlation was statistically significant (r = 0.312, p = 0.033). Results of this study provided more direct insight into the mechanism of CE-SSCP and showed that MFOLD prediction could be helpful in making decisions about the running temperatures and in prediction of CE-SSCP data patterns, especially for shorter (50-100 bp) DNA fragments. Copyright 2002 Wiley-Liss, Inc.

Integrating physiological threshold experiments with climate modeling to project mangrove species' range expansion.

PubMed

Cavanaugh, Kyle C; Parker, John D; Cook-Patton, Susan C; Feller, Ilka C; Williams, A Park; Kellner, James R

2015-05-01

Predictions of climate-related shifts in species ranges have largely been based on correlative models. Due to limitations of these models, there is a need for more integration of experimental approaches when studying impacts of climate change on species distributions. Here, we used controlled experiments to identify physiological thresholds that control poleward range limits of three species of mangroves found in North America. We found that all three species exhibited a threshold response to extreme cold, but freeze tolerance thresholds varied among species. From these experiments, we developed a climate metric, freeze degree days (FDD), which incorporates both the intensity and the frequency of freezes. When included in distribution models, FDD accurately predicted mangrove presence/absence. Using 28 years of satellite imagery, we linked FDD to observed changes in mangrove abundance in Florida, further exemplifying the importance of extreme cold. We then used downscaled climate projections of FDD to project that these range limits will move northward by 2.2-3.2 km yr(-1) over the next 50 years. © 2014 John Wiley & Sons Ltd.

Systematic Review and Meta-analysis of the Effects of Caffeine in Fatigued Shift Workers: Implications for Emergency Medical Services Personnel

DOT National Transportation Integrated Search

2018-01-11

Background: Emergency Medical Services (EMS) workers may experience fatigue as a consequence of shift work. We reviewed the literature to determine the impact of caffeine as a countermeasure to fatigue in EMS personnel and related shift workers. Meth...

The experience of being a shift-leader in a hospital ward.

PubMed

Goldblatt, Hadass; Granot, Michal; Admi, Hanna; Drach-Zahavy, Anat

2008-07-01

This paper is a report of a study to explore the experience of being a shift-leader, and how these nurses view the management of their shift. Professional demands on skilled and capable shift-leaders, who competently handle multi-disciplinary staff and patients, as well as operations and information, call for the development of efficient nursing leadership roles. Nevertheless, knowledge of shift-leaders' perspectives concerning their task management and leadership styles is relatively limited. Twenty-eight Registered Nurses working in an Israeli medical centre participated in this qualitative study. Data were gathered through in-depth interviews conducted in two phases between February and October 2005: three focus group interviews (phase 1) followed by seven individual interviews (phase 2). Content analysis revealed two major themes which constitute the essence of being a shift-leader: (1) a burden of responsibility, where the shift-leader moves between positions of maximum control and delegating some responsibility to other nurses; (2) the role's temporal dimension, expressed as a strong desire to reach the end of the shift safely, and taking managerial perspectives beyond the boundaries of the specific shift. The core of the shift-leader's position is an immense sense of responsibility. However, this managerial role is transient and therefore lacks an established authority. A two-dimensional taxonomy of these themes reveals four types of potential and actual coping among shift-leaders, indicating the need to train them in leadership skills and systemic thinking. Interventions to limit the potential stress hazards should be focused simultaneously on shift-leaders themselves and on job restructuring.

Galaxy Bias and its Effects on the Baryon Acoustic Oscillations Measurements

NASA Astrophysics Data System (ADS)

Mehta, Kushal; Seo, H.; Eckel, J.; Eisenstein, D.; Metchnik, M.; Pinto, P.; Xu, X.

2011-05-01

The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al (2010). For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07% - 0.15%.

Galaxy Bias and Its Effects on the Baryon Acoustic Oscillation Measurements

NASA Astrophysics Data System (ADS)

Mehta, Kushal T.; Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Metchnik, Marc; Pinto, Philip; Xu, Xiaoying

2011-06-01

The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the nonlinear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al. For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields, achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07%-0.15%.

Shape shifting predicts ontogenetic changes in metabolic scaling in diverse aquatic invertebrates

PubMed Central

Glazier, Douglas S.; Hirst, Andrew G.; Atkinson, David

2015-01-01

Metabolism fuels all biological activities, and thus understanding its variation is fundamentally important. Much of this variation is related to body size, which is commonly believed to follow a 3/4-power scaling law. However, during ontogeny, many kinds of animals and plants show marked shifts in metabolic scaling that deviate from 3/4-power scaling predicted by general models. Here, we show that in diverse aquatic invertebrates, ontogenetic shifts in the scaling of routine metabolic rate from near isometry (bR = scaling exponent approx. 1) to negative allometry (bR < 1), or the reverse, are associated with significant changes in body shape (indexed by bL = the scaling exponent of the relationship between body mass and body length). The observed inverse correlations between bR and bL are predicted by metabolic scaling theory that emphasizes resource/waste fluxes across external body surfaces, but contradict theory that emphasizes resource transport through internal networks. Geometric estimates of the scaling of surface area (SA) with body mass (bA) further show that ontogenetic shifts in bR and bA are positively correlated. These results support new metabolic scaling theory based on SA influences that may be applied to ontogenetic shifts in bR shown by many kinds of animals and plants. PMID:25652833

A Blue Spectral Shift of the Hemoglobin Soret Band Correlates with the Age (Time Since Deposition) of Dried Bloodstains

PubMed Central

Hanson, Erin K.; Ballantyne, Jack

2010-01-01

The ability to determine the time since deposition of a bloodstain found at a crime scene could prove invaluable to law enforcement investigators, defining the time frame in which the individual depositing the evidence was present. Although various methods of accomplishing this have been proposed, none has gained widespread use due to poor time resolution and weak age correlation. We have developed a method for the estimation of the time since deposition (TSD) of dried bloodstains using UV-VIS spectrophotometric analysis of hemoglobin (Hb) that is based upon its characteristic oxidation chemistry. A detailed study of the Hb Soret band (λmax = 412 nm) in aged bloodstains revealed a blue shift (shift to shorter wavelength) as the age of the stain increases. The extent of this shift permits, for the first time, a distinction to be made between bloodstains that were deposited minutes, hours, days and weeks prior to recovery and analysis. The extent of the blue shift was found to be a function of ambient relative humidity and temperature. The method is extremely sensitive, requiring as little as a 1 µl dried bloodstain for analysis. We demonstrate that it might be possible to perform TSD measurements at the crime scene using a portable low-sample-volume spectrophotometer. PMID:20877468

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

Tanabe, S; Utsunomiya, S; Abe, E

Purpose: To assess an accuracy of fiducial maker-based setup using ExacTrac (ExT-based setup) as compared with soft tissue-based setup using Cone-beam CT (CBCT-based setup) for patients with prostate cancer receiving intensity-modulated radiation therapy (IMRT) for the purpose of investigating whether ExT-based setup can be an alternative to CBCT-based setup. Methods: The setup accuracy was analyzed prospectively for 7 prostate cancer patients with implanted three fiducial markers received IMRT. All patients were treated after CBCT-based setup was performed and corresponding shifts were recorded. ExacTrac images were obtained before and after CBCT-based setup. The fiducial marker-based shifts were calculated based on thosemore » two images and recorded on the assumption that the setup correction was carried out by fiducial marker-based auto correction. Mean and standard deviation of absolute differences and the correlation between CBCT and ExT shifts were estimated. Results: A total of 178 image dataset were analyzed. On the differences between CBCT and ExT shifts, 133 (75%) of 178 image dataset resulted in smaller differences than 3 mm in all dimensions. Mean differences in the anterior-posterior (AP), superior-inferior (SI), and left-right (LR) dimensions were 1.8 ± 1.9 mm, 0.7 ± 1.9 mm, and 0.6 ± 0.8 mm, respectively. The percentages of shift agreements within ±3 mm were 76% for AP, 90% for SI, and 100% for LR. The Pearson coefficient of correlation for CBCT and ExT shifts were 0.80 for AP, 0.80 for SI, and 0.65 for LR. Conclusion: This work showed that the accuracy of ExT-based setup was correlated with that of CBCT-based setup, implying that ExT-based setup has a potential ability to be an alternative to CBCT-based setup. The further work is to specify the conditions that ExT-based setup can provide the accuracy comparable to CBCT-based setup.« less

Cellulose Structural Polymorphism in Plant Primary Cell Walls Investigated by High-Field 2D Solid-State NMR Spectroscopy and Density Functional Theory Calculations.

PubMed

Wang, Tuo; Yang, Hui; Kubicki, James D; Hong, Mei

2016-06-13

The native cellulose of bacterial, algal, and animal origins has been well studied structurally using X-ray and neutron diffraction and solid-state NMR spectroscopy, and is known to consist of varying proportions of two allomorphs, Iα and Iβ, which differ in hydrogen bonding, chain packing, and local conformation. In comparison, cellulose structure in plant primary cell walls is much less understood because plant cellulose has lower crystallinity and extensive interactions with matrix polysaccharides. Here we have combined two-dimensional magic-angle-spinning (MAS) solid-state nuclear magnetic resonance (solid-state NMR) spectroscopy at high magnetic fields with density functional theory (DFT) calculations to obtain detailed information about the structural polymorphism and spatial distributions of plant primary-wall cellulose. 2D (13)C-(13)C correlation spectra of uniformly (13)C-labeled cell walls of several model plants resolved seven sets of cellulose chemical shifts. Among these, five sets (denoted a-e) belong to cellulose in the interior of the microfibril while two sets (f and g) can be assigned to surface cellulose. Importantly, most of the interior cellulose (13)C chemical shifts differ significantly from the (13)C chemical shifts of the Iα and Iβ allomorphs, indicating that plant primary-wall cellulose has different conformations, packing, and hydrogen bonding from celluloses of other organisms. 2D (13)C-(13)C correlation experiments with long mixing times and with water polarization transfer revealed the spatial distributions and matrix-polysaccharide interactions of these cellulose structures. Celluloses f and g are well mixed chains on the microfibril surface, celluloses a and b are interior chains that are in molecular contact with the surface chains, while cellulose c resides in the core of the microfibril, outside spin diffusion contact with the surface. Interestingly, cellulose d, whose chemical shifts differ most significantly from those of bacterial, algal, and animal cellulose, interacts with hemicellulose, is poorly hydrated, and is targeted by the protein expansin during wall loosening. To obtain information about the C6 hydroxymethyl conformation of these plant celluloses, we carried out DFT calculations of (13)C chemical shifts, using the Iα and Iβ crystal structures as templates and varying the C5-C6 torsion angle. Comparison with the experimental chemical shifts suggests that all interior cellulose favor the tg conformation, but cellulose d also has a similar propensity to adopt the gt conformation. These results indicate that cellulose in plant primary cell walls, due to their interactions with matrix polysaccharides, and has polymorphic structures that are not a simple superposition of the Iα and Iβ allomorphs, thus distinguishing them from bacterial and animal celluloses.

Cellulose Structural Polymorphism in Plant Primary Cell Walls Investigated by High-Field 2D Solid-State NMR Spectroscopy and Density Functional Theory Calculations

PubMed Central

Wang, Tuo; Yang, Hui; Kubicki, James D.; Hong, Mei

2017-01-01

The native cellulose of bacterial, algal, and animal origins has been well studied structurally using X-ray and neutron diffraction and solid-state NMR spectroscopy, and is known to consist of varying proportions of two allomorphs, Iα and Iβ, which differ in hydrogen bonding, chain packing, and local conformation. In comparison, cellulose structure in plant primary cell walls is much less understood because plant cellulose has lower crystallinity and extensive interactions with matrix polysaccharides. Here we have combined two-dimensional magic-angle-spinning (MAS) solid-state nuclear magnetic resonance (solid-state NMR) spectroscopy at high magnetic fields with density functional theory (DFT) calculations to obtain detailed information about the structural polymorphism and spatial distributions of plant primary-wall cellulose. 2D 13C-13C correlation spectra of uniformly 13C-labeled cell walls of several model plants resolved seven sets of cellulose chemical shifts. Among these, five sets (denoted a-e) belong to cellulose in the interior of the microfibril while two sets (f and g) can be assigned to surface cellulose. Importantly, most of the interior cellulose 13C chemical shifts differ significantly from the 13C chemical shifts of the Iα and Iβ allomorphs, indicating that plant primary-wall cellulose has different conformations, packing and hydrogen bonding from celluloses of other organisms. 2D 13C-13C correlation experiments with long mixing times and with water polarization transfer revealed the spatial distributions and matrix-polysaccharide interactions of these cellulose structures. Cellulose f and g are well mixed chains on the microfibril surface, cellulose a and b are interior chains that are in molecular contact with the surface chains, while cellulose c resides in the core of the microfibril, outside spin diffusion contact with the surface. Interestingly, cellulose d, whose chemical shifts differ most significantly from those of bacterial, algal and animal cellulose, interacts with hemicellulose, is poorly hydrated, and is targeted by the protein expansin during wall loosening. To obtain information about the C6 hydroxymethyl conformation of these plant celluloses, we carried out DFT calculations of 13C chemical shifts, using the Iα and Iβ crystal structures as templates and varying the C5-C6 torsion angle. Comparison with the experimental chemical shifts suggests that all interior cellulose favor the tg conformation, but cellulose d also has a similar propensity to adopt the gt conformation. These results indicate that cellulose in plant primary cell walls, due to their interactions with matrix polysaccharides, has polymorphic structures that are not a simple superposition of the Iα and Iβ allomorphs, thus distinguishing them from bacterial and animal celluloses. PMID:27192562

Vision based tunnel inspection using non-rigid registration

NASA Astrophysics Data System (ADS)

Badshah, Amir; Ullah, Shan; Shahzad, Danish

2015-04-01

Growing numbers of long tunnels across the globe has increased the need for safety measurements and inspections of tunnels in these days. To avoid serious damages, tunnel inspection is highly recommended at regular intervals of time to find any deformations or cracks at the right time. While following the stringent safety and tunnel accessibility standards, conventional geodetic surveying using techniques of civil engineering and other manual and mechanical methods are time consuming and results in troublesome of routine life. An automatic tunnel inspection by image processing techniques using non rigid registration has been proposed. There are many other image processing methods used for image registration purposes. Most of the processes are operation of images in its spatial domain like finding edges and corners by Harris edge detection method. These methods are quite time consuming and fail for some or other reasons like for blurred or images with noise. Due to use of image features directly by these methods in the process, are known by the group, correlation by image features. The other method is featureless correlation, in which the images are converted into its frequency domain and then correlated with each other. The shift in spatial domain is the same as in frequency domain, but the processing is order faster than in spatial domain. In the proposed method modified normalized phase correlation has been used to find any shift between two images. As pre pre-processing the tunnel images i.e. reference and template are divided into small patches. All these relative patches are registered by the proposed modified normalized phase correlation. By the application of the proposed algorithm we get the pixel movement of the images. And then these pixels shifts are converted to measuring units like mm, cm etc. After the complete process if there is any shift in the tunnel at described points are located.

Correlation of chemical shifts predicted by molecular dynamics simulations for partially disordered proteins.

PubMed

Karp, Jerome M; Eryilmaz, Ertan; Erylimaz, Ertan; Cowburn, David

2015-01-01

There has been a longstanding interest in being able to accurately predict NMR chemical shifts from structural data. Recent studies have focused on using molecular dynamics (MD) simulation data as input for improved prediction. Here we examine the accuracy of chemical shift prediction for intein systems, which have regions of intrinsic disorder. We find that using MD simulation data as input for chemical shift prediction does not consistently improve prediction accuracy over use of a static X-ray crystal structure. This appears to result from the complex conformational ensemble of the disordered protein segments. We show that using accelerated molecular dynamics (aMD) simulations improves chemical shift prediction, suggesting that methods which better sample the conformational ensemble like aMD are more appropriate tools for use in chemical shift prediction for proteins with disordered regions. Moreover, our study suggests that data accurately reflecting protein dynamics must be used as input for chemical shift prediction in order to correctly predict chemical shifts in systems with disorder.

Refinement of Global Phase-Shift Analysis for p+^3He Elastic Scattering Using Spin-Correlation Coefficients

NASA Astrophysics Data System (ADS)

Daniels, Tim; Arnold, Charles; Cesaratto, John; Clegg, Thomas; Couture, Alexander; Imig, Astrid; Karwowski, Hugon

2008-10-01

As part of an investigation of the A=4 system, we measured the spin-correlation coefficients Ayo, Aoy, Ayy, and Axx for p-^3He elastic scattering at Elab of 2.3, 2.7, 4.0, and 5.5 MeV and θlab between 30^o and 150^o. The data were taken using TUNL's atomic beam polarized ion source and our spin-exchange optical pumping polarized ^3He targetootnotetextT. Katabuchi et al., Rev. Sci. Instrum. 76, 033503 (2005). We aim to resolve ambiguities in the phase shifts of George and KnutsonootnotetextE.A. George and L.D. Knutson, Phys Rev C 67, 027001 (2003), which seem most sensitive to Axx and Ayy at the lowest of these energies. Our measurements will be shown with phase-shift-analysis solutions, as well as some discussion of systematic effects related to the steering of charged particles by the target's magnetic field.

Intelligence, creativity, and cognitive control: The common and differential involvement of executive functions in intelligence and creativity

PubMed Central

Benedek, Mathias; Jauk, Emanuel; Sommer, Markus; Arendasy, Martin; Neubauer, Aljoscha C.

2014-01-01

Intelligence and creativity are known to be correlated constructs suggesting that they share a common cognitive basis. The present study assessed three specific executive abilities – updating, shifting, and inhibition – and examined their common and differential relations to fluid intelligence and creativity (i.e., divergent thinking ability) within a latent variable model approach. Additionally, it was tested whether the correlation of fluid intelligence and creativity can be explained by a common executive involvement. As expected, fluid intelligence was strongly predicted by updating, but not by shifting or inhibition. Creativity was predicted by updating and inhibition, but not by shifting. Moreover, updating (and the personality factor openness) was found to explain a relevant part of the shared variance between intelligence and creativity. The findings provide direct support for the executive involvement in creative thought and shed further light on the functional relationship between intelligence and creativity. PMID:25278640

A Mössbauer effect study of the bonding in several organoiron carbonyl clusters

NASA Astrophysics Data System (ADS)

Long, Gary J.; O'Brien, James F.

1988-02-01

After a brief review of the applications of the Mössbauer effect to cyclopentadienyl containing compounds, the chemistry and spectral properties of the various iron carbonyl complexes are described. The electronic properties of a series of trinuclear and tetranuclear organoiron clusters have been investigated through Fenske-Hall self-consistent field molecular orbital calculations, and the results are compared with the Mössbauer effect isomer shifts. A linear correlation is found between the Slater effective nuclear charge, as calculated from the Fenske-Hall partial orbital occupancy factors, and the isomer shift. In these compounds the 4s orbital populations are rather constant. However, the cis and trans isomers of [CpFe(CO)2]2 have a significantly lower 4s orbital populations. In this case, the reduced 4s population must be accounted for by adding it to the effective nuclear charge to obtain a good correlation with the isomer shift.

Chemical Shift MR Imaging Methods for the Quantification of Transcatheter Lipiodol Delivery to the Liver: Preclinical Feasibility Studies in a Rodent Model

PubMed Central

Yin, Xiaoming; Guo, Yang; Li, Weiguo; Huo, Eugene; Zhang, Zhuoli; Nicolai, Jodi; Kleps, Robert A.; Hernando, Diego; Katsaggelos, Aggelos K.; Omary, Reed A.

2012-01-01

Purpose: To demonstrate the feasibility of using chemical shift magnetic resonance (MR) imaging fat-water separation methods for quantitative estimation of transcatheter lipiodol delivery to liver tissues. Materials and Methods: Studies were performed in accordance with institutional Animal Care and Use Committee guidelines. Proton nuclear MR spectroscopy was first performed to identify lipiodol spectral peaks and relative amplitudes. Next, phantoms were constructed with increasing lipiodol-water volume fractions. A multiecho chemical shift–based fat-water separation method was used to quantify lipiodol concentration within each phantom. Six rats served as controls; 18 rats underwent catheterization with digital subtraction angiography guidance for intraportal infusion of a 15%, 30%, or 50% by volume lipiodol-saline mixture. MR imaging measurements were used to quantify lipiodol delivery to each rat liver. Lipiodol concentration maps were reconstructed by using both single-peak and multipeak chemical shift models. Intraclass and Spearman correlation coefficients were calculated for statistical comparison of MR imaging–based lipiodol concentration and volume measurements to reference standards (known lipiodol phantom compositions and the infused lipiodol dose during rat studies). Results: Both single-peak and multipeak measurements were well correlated to phantom lipiodol concentrations (r2 > 0.99). Lipiodol volume measurements were progressively and significantly higher when comparing between animals receiving different doses (P < .05 for each comparison). MR imaging–based lipiodol volume measurements strongly correlated with infused dose (intraclass correlation coefficients > 0.93, P < .001) with both single- and multipeak approaches. Conclusion: Chemical shift MR imaging fat-water separation methods can be used for quantitative measurements of lipiodol delivery to liver tissues. © RSNA, 2012 PMID:22623693

Application of P-wave Hybrid Theory to the Scattering of Electrons from He+ and Resonances in He and H ion

NASA Technical Reports Server (NTRS)

Bhatia, A. K.

2012-01-01

The P-wave hybrid theory of electron-hydrogen elastic scattering [Phys. Rev. A 85, 052708 (2012)] is applied to the P-wave scattering from He ion. In this method, both short-range and long-range correlations are included in the Schroedinger equation at the same time, by using a combination of a modified method of polarized orbitals and the optical potential formalism. The short-correlation functions are of Hylleraas type. It is found that the phase shifts are not significantly affected by the modification of the target function by a method similar to the method of polarized orbitals and they are close to the phase shifts calculated earlier by Bhatia [Phys. Rev. A 69, 032714 (2004)]. This indicates that the correlation function is general enough to include the target distortion (polarization) in the presence of the incident electron. The important fact is that in the present calculation, to obtain similar results only a 20-term correlation function is needed in the wave function compared to the 220- term wave function required in the above-mentioned calculation. Results for the phase shifts, obtained in the present hybrid formalism, are rigorous lower bounds to the exact phase shifts. The lowest P-wave resonances in He atom and hydrogen ion have been calculated and compared with the results obtained using the Feshbach projection operator formalism [Phys. Rev. A, 11, 2018 (1975)]. It is concluded that accurate resonance parameters can be obtained by the present method, which has the advantage of including corrections due to neighboring resonances, bound states and the continuum in which these resonance are embedded.

Extrinsic regime shifts drive abrupt changes in regeneration dynamics at upper treeline in the Rocky Mountains, U.S.A.

PubMed

Elliott, Grant P

2012-07-01

Given the widespread and often dramatic influence of climate change on terrestrial ecosystems, it is increasingly common for abrupt threshold changes to occur, yet explicitly testing for climate and ecological regime shifts is lacking in climatically sensitive upper treeline ecotones. In this study, quantitative evidence based on empirical data is provided to support the key role of extrinsic, climate-induced thresholds in governing the spatial and temporal patterns of tree establishment in these high-elevation environments. Dendroecological techniques were used to reconstruct a 420-year history of regeneration dynamics within upper treeline ecotones along a latitudinal gradient (approximately 44-35 degrees N) in the Rocky Mountains. Correlation analysis was used to assess the possible influence of minimum and maximum temperature indices and cool-season (November-April) precipitation on regional age-structure data. Regime-shift analysis was used to detect thresholds in tree establishment during the entire period of record (1580-2000), temperature variables significantly Correlated with establishment during the 20th century, and cool-season precipitation. Tree establishment was significantly correlated with minimum temperature during the spring (March-May) and cool season. Regime-shift analysis identified an abrupt increase in regional tree establishment in 1950 (1950-1954 age class). Coincident with this period was a shift toward reduced cool-season precipitation. The alignment of these climate conditions apparently triggered an abrupt increase in establishment that was unprecedented during the period of record. Two main findings emerge from this research that underscore the critical role of climate in governing regeneration dynamics within upper treeline ecotones. (1) Regional climate variability is capable of exceeding bioclimatic thresholds, thereby initiating synchronous and abrupt changes in the spatial and temporal patterns of tree establishment at broad regional scales. (2) The importance of climate parameters exceeding critical threshold values and triggering a regime shift in tree establishment appears to be contingent on the alignment of favorable temperature and moisture regimes. This research suggests that threshold changes in the climate system can fundamentally alter regeneration dynamics within upper treeline ecotones and, through the use of regime-shift analysis, reveals important climate-vegetation linkages.

Associations of hypoosmotic swelling test, relative sperm volume shift, aquaporin7 mRNA abundance and bull fertility estimates.

PubMed

Kasimanickam, R K; Kasimanickam, V R; Arangasamy, A; Kastelic, J P

2017-02-01

Mammalian sperm are exposed to a natural hypoosmotic environment during male-to-female reproductive tract transition; although this activates sperm motility in vivo, excessive swelling can harm sperm structure and function. Aquaporins (AQPs) is a family of membrane-channel proteins implicated in sperm osmoregulation. The objective was to determine associations among relative sperm volume shift, hypoosmotic swelling test (HOST), sperm aquaporin (AQP) 7 mRNA abundances, and sire conception rate (SCR; fertility estimate) in Holstein bulls at a commercial artificial insemination center. Three or four sires for each full point SCR score from -4 to +4 were included. Each SCR estimate for study bulls (N = 30) was based on > 500 services (mean ± SEM) of 725 ± 13 services/sire). Sperm from a single collection day (two ejaculates) from these commercial Holstein bulls were used. Relative mRNA expression of AQP7 in sperm was determined by polymerase chain reaction. Mean relative sperm volume shift and percentage of sperm reacted in a HOST (% HOST) were determined (400 sperm per bull) after incubating in isoosmotic (300 mOsm/kg) and hypoosmotic (100 mOsm/kg) solutions for 30 min. There was no correlation between %HOST and SCR (r = 0.28 P > 0.1). However, there was a positive correlation between relative sperm volume shift and SCR (r = 0.65, P < 0.05). Furthermore, AQP7 mRNA abundance was positively correlated to both relative volume shift (r = 0.73; P < 0.05) and to SCR (r = 0.67; P < 0.05). The mRNA expressions of AQP7 and relative sperm volume shift differed (P < 0.05) among low- (<2 SCR), average- (-2 to +2) and high- (>2) fertility sire groups. In conclusion, bulls with higher SCR had significantly greater AQP7 mRNA abundance in frozen-thawed sperm. This plausibly contributed to greater regulation of sperm volume shift, which apparently conferred protection from detrimental swelling and impaired functions. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamics of a quantum spin liquid beyond integrability: The Kitaev-Heisenberg-Γ model in an augmented parton mean-field theory

NASA Astrophysics Data System (ADS)

Knolle, Johannes; Bhattacharjee, Subhro; Moessner, Roderich

2018-04-01

We present an augmented parton mean-field theory which (i) reproduces the exact ground state, spectrum, and dynamics of the quantum spin-liquid phase of Kitaev's honeycomb model, and (ii) is amenable to the inclusion of integrability breaking terms, allowing a perturbation theory from a controlled starting point. Thus, we exemplarily study dynamical spin correlations of the honeycomb Kitaev quantum spin liquid within the K -J -Γ model, which includes Heisenberg and symmetric-anisotropic (pseudodipolar) interactions. This allows us to trace changes of the correlations in the regime of slowly moving fluxes, where the theory captures the dominant deviations when integrability is lost. These include an asymmetric shift together with a broadening of the dominant peak in the response as a function of frequency, the generation of further-neighbor correlations and their structure in real and spin space, and a resulting loss of an approximate rotational symmetry of the structure factor in reciprocal space. We discuss the limitations of this approach and also view the neutron-scattering experiments on the putative proximate quantum spin-liquid material α -RuCl3 in the light of the results from this extended parton theory.

On the Mechanism for a Gravity Effect Using Type 2 Superconductors

NASA Technical Reports Server (NTRS)

Robertson, Glen A.

1999-01-01

In this paper, we formulate a percent mass change equation based on Woodward's transient mass shift and the Cavendish balance equations applied to superconductor Josephson junctions, A correction to the transient mass shift equation is presented due to the emission of the mass energy from the superconductor. The percentage of mass change predicted by the equation was estimated against the maximum percent mass change reported by Podkletnov in his gravity shielding experiments. An experiment is then discussed, which could shed light on the transient mass shift near superconductor and verify the corrected gravitational potential.

Optics in neural computation

NASA Astrophysics Data System (ADS)

Levene, Michael John

In all attempts to emulate the considerable powers of the brain, one is struck by both its immense size, parallelism, and complexity. While the fields of neural networks, artificial intelligence, and neuromorphic engineering have all attempted oversimplifications on the considerable complexity, all three can benefit from the inherent scalability and parallelism of optics. This thesis looks at specific aspects of three modes in which optics, and particularly volume holography, can play a part in neural computation. First, holography serves as the basis of highly-parallel correlators, which are the foundation of optical neural networks. The huge input capability of optical neural networks make them most useful for image processing and image recognition and tracking. These tasks benefit from the shift invariance of optical correlators. In this thesis, I analyze the capacity of correlators, and then present several techniques for controlling the amount of shift invariance. Of particular interest is the Fresnel correlator, in which the hologram is displaced from the Fourier plane. In this case, the amount of shift invariance is limited not just by the thickness of the hologram, but by the distance of the hologram from the Fourier plane. Second, volume holography can provide the huge storage capacity and high speed, parallel read-out necessary to support large artificial intelligence systems. However, previous methods for storing data in volume holograms have relied on awkward beam-steering or on as-yet non- existent cheap, wide-bandwidth, tunable laser sources. This thesis presents a new technique, shift multiplexing, which is capable of very high densities, but which has the advantage of a very simple implementation. In shift multiplexing, the reference wave consists of a focused spot a few millimeters in front of the hologram. Multiplexing is achieved by simply translating the hologram a few tens of microns or less. This thesis describes the theory for how shift multiplexing works based on an unconventional, but very intuitive, analysis of the optical far-field. A more detailed analysis based on a path-integral interpretation of the Born approximation is also derived. The capacity of shift multiplexing is compared with that of angle and wavelength multiplexing. The last part of this thesis deals with the role of optics in neuromorphic engineering. Up until now, most neuromorphic engineering has involved one or a few VLSI circuits emulating early sensory systems. However, optical interconnects will be required in order to push towards more ambitious goals, such as the simulation of early visual cortex. I describe a preliminary approach to designing such a system, and show how shift multiplexing can be used to simultaneously store and implement the immense interconnections required by such a project.

Effects of Phonological and Orthographic Shifts on Children's Processing of Written Morphology: A Time-Course Study

ERIC Educational Resources Information Center

Quémart, Pauline; Casalis, Séverine

2014-01-01

We report two experiments that investigated whether phonological and/or orthographic shifts in a base word interfere with morphological processing by French 3rd, 4th, and 5th graders and adults (as a control group) along the time course of visual word recognition. In both experiments, prime-target pairs shared four possible relationships:…

Effect of a Surprising Downward Shift in Reinforcer Value on Stimulus Over-Selectivity in a Simultaneous Discrimination Procedure

ERIC Educational Resources Information Center

Reynolds, Gemma; Reed, Phil

2013-01-01

Stimulus over-selectivity refers to the phenomenon whereby behavior is controlled by a subset of elements in the environment at the expense of other equally salient aspects of the environment. The experiments explored whether this cue interference effect was reduced following a surprising downward shift in reinforcer value. Experiment 1 revealed…

Heavy NP shift is the parser’s last resort: Evidence from eye movements ⋆

PubMed Central

Staub, Adrian; Clifton, Charles; Frazier, Lyn

2006-01-01

Two eye movement experiments explored the roles of verbal subcategorization possibilities and transitivity biases in the processing of heavy NP shift sentences in which the verb’s direct object appears to the right of a post-verbal phrase. In Experiment 1, participants read sentences in which a prepositional phrase immediately followed the verb, which was either obligatorily transitive or had a high transitivity bias (e.g., Jack praised/watched from the stands his daughter’s attempt to shoot a basket). Experiment 2 compared unshifted sentences to sentences in which an adverb intervened between the verb and its object, and obligatorily transitive verbs to optionally transitive verbs with widely varying transitivity biases. In both experiments, evidence of processing difficulty appeared on the material that intervened between the verb and its object when the verb was obligatorily transitive, and on the shifted direct object when the verb was optionally transitive, regardless of transitivity bias. We conclude that the parser adopts the heavy NP shift analysis only when it is forced to by the grammar, which we interpret in terms of a preference for immediate incremental interpretation. PMID:17047731

Automatic frequency and phase alignment of in vivo J-difference-edited MR spectra by frequency domain correlation.

PubMed

Wiegers, Evita C; Philips, Bart W J; Heerschap, Arend; van der Graaf, Marinette

2017-12-01

J-difference editing is often used to select resonances of compounds with coupled spins in 1 H-MR spectra. Accurate phase and frequency alignment prior to subtracting J-difference-edited MR spectra is important to avoid artefactual contributions to the edited resonance. In-vivo J-difference-edited MR spectra were aligned by maximizing the normalized scalar product between two spectra (i.e., the correlation over a spectral region). The performance of our correlation method was compared with alignment by spectral registration and by alignment of the highest point in two spectra. The correlation method was tested at different SNR levels and for a broad range of phase and frequency shifts. In-vivo application of the proposed correlation method showed reduced subtraction errors and increased fit reliability in difference spectra as compared with conventional peak alignment. The correlation method and the spectral registration method generally performed equally well. However, better alignment using the correlation method was obtained for spectra with a low SNR (down to ~2) and for relatively large frequency shifts. Our correlation method for simultaneously phase and frequency alignment is able to correct both small and large phase and frequency drifts and also performs well at low SNR levels.

Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.

PubMed

Postnova, Svetlana; Robinson, Peter A; Postnov, Dmitry D

2013-01-01

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

The relationship between quality of sleep and night shift rotation interval.

PubMed

Kim, Jae Youn; Chae, Chang Ho; Kim, Young Ouk; Son, Jun Seok; Kim, Ja Hyun; Kim, Chan Woo; Park, Hyoung Ouk; Lee, Jun Ho; Kwon, Soon Il; Kwon, Sun Il

2015-01-01

Shift work is closely related with workers' health. In particular, sleep is thought to be affected by shift work. In addition, shift work has been reported to be associated with the type or direction of shift rotation, number of consecutive night shifts, and number of off-duty days. We aimed to analyze the association between the night shift rotation interval and the quality of sleep reported by Korean female shift workers. In total, 2,818 female shift workers from the manufacturing industry who received an employee physical examination at a single university hospital from January to August in 2014 were included. Subjects were classified into three groups (A, B, and C) by their night shift rotation interval. The quality of sleep was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI). Descriptive analysis, univariate logistic regression, and multivariate logistic regression were performed. With group A as the reference, the odds ratio (OR) for having a seriously low quality of sleep was 1.456 (95% CI 1.171-1.811) and 2.348 (95% CI 1.852-2.977) for groups B and C, respectively. Thus, group C with the shortest night shift rotation interval was most likely to have a low quality of sleep. After adjustment for age, obesity, smoking status, alcohol consumption, exercise, being allowed to sleep during night shifts, work experience, and shift work experience, groups B and C had ORs of 1.419 (95% CI 1.134-1.777) and 2.238 (95% CI 1.737-2.882), respectively, compared to group A. Our data suggest that a shorter night shift rotation interval does not provide enough recovery time to adjust the circadian rhythm, resulting in a low quality of sleep. Because shift work is influenced by many different factors, future studies should aim to determine the most optimal shift work model and collect accurate, prospective data.

Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties

NASA Technical Reports Server (NTRS)

Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

1972-01-01

The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

Preliminary study of detection of buried landmines using a programmable hyperspectral imager

NASA Astrophysics Data System (ADS)

McFee, John E.; Ripley, Herb T.; Buxton, Roger; Thriscutt, Andrew M.

1996-05-01

Experiments were conducted to determine if buried mines could be detected by measuring the change in reflectance spectra of vegetation above mine burial sites. Mines were laid using hand methods and simulated mechanical methods and spectral images were obtained over a three month period using a casi hyperspectral imager scanned from a personnel lift. Mines were not detectable by measurement of the shift of the red edge of vegetative spectra. By calculating the linear correlation coefficient image, some mines in light vegetative cover (grass, grass/blueberries) were apparently detected, but mines buried in heavy vegetation cover (deep ferns) were not detectable. Due to problems with ground truthing, accurate probabilities of detection and false alarm rates were not obtained.

First-principles studies of PETN molecular crystal vibrational frequencies under high pressure

NASA Astrophysics Data System (ADS)

Perger, Warren; Zhao, Jijun

2005-07-01

The vibrational frequencies of the PETN molecular crystal were calculated using the first-principles CRYSTAL03 program which employs an all-electron LCAO approach and calculates analytic first derivatives of the total energy with respect to atomic displacements. Numerical second derivatives were used to enable calculation of the vibrational frequencies at ambient pressure and under various states of compression. Three different density functionals, B3LYP, PW91, and X3LYP were used to examine the effect of the exchange-correlation functional on the vibrational frequencies. The pressure-induced shift of the vibrational frequencies will be presented and compared with experiment. The average deviation with experimental results is shown to be on the order of 2-3%, depending on the functional used.

Proton-proton elastic scattering excitation functions at intermediate energies

NASA Astrophysics Data System (ADS)

Rohdjess, H.

1998-05-01

Polarized and unpolarized proton-proton elastic scattering is investigated with the EDDA-experiment at the Cooler Synchrotron COSY at Jülich to significantly improve the world data base in the beam energy range 500-2500 MeV. Measurements during beam acceleration with thin internal targets and a large acceptance detector provide excitation functions over a broad angular and energy range with unprecedented internal consistency. Data taking with an unpolarized CH2 fiber target and an unpolarized beam have been completed and the derived differential cross sections are presented and compared to a recent phase shift analysis. With a polarized atomic beam target newly installed in COSY and a polarized COSY beam—currently under development—the measurements will be extended to analyzing powers and spin correlation parameters.

Theory and observations of high frequency Alfvén eigenmodes in low aspect ratio plasmas

NASA Astrophysics Data System (ADS)

Gorelenkov, N. N.; Fredrickson, E.; Belova, E.; Cheng, C. Z.; Gates, D.; Kaye, S.; White, R.

2003-04-01

New observations of sub-cyclotron frequency instability in low aspect ratio plasmas in national spherical torus experiments are reported. The frequencies of observed instabilities correlate with the characteristic Alfvén velocity of the plasma. A theory of localized compressional Alfvén eigenmodes (CAE) and global shear Alfvén eigenmodes (GAE) in low aspect ratio plasmas is presented to explain the observed high frequency instabilities. CAEs/GAEs are driven by the velocity space gradient of energetic super-Alfvénic beam ions via Doppler shifted cyclotron resonances. One of the main damping mechanisms of GAEs, the continuum damping, is treated perturbatively within the framework of ideal MHD. Properties of these cyclotron instability ions are presented.

Chemical Mass Shifts in a Digital Linear Ion Trap as Analytical Identity of o-, m-, and p-Xylene.

PubMed

Sun, Lulu; Xue, Bing; Huang, Zhengxu; Cheng, Ping; Ma, Li; Ding, Li; Zhou, Zhen

2018-07-01

Chemical mass shifts between isomeric ions of o-, m-, and p-xylene were measured using a digital linear ion trap, and the directions and values of the shifts were found to be correlated to the collision cross sections of the isomers. Both forward and reverse scans were used and the chemical shifts for each pair of isomers in scans of opposite directions were in opposite signs. Using different voltage settings (namely the voltage dividing ratio-VDR) of the ion trap allows adding high order field components in the quadrupole field and results in larger chemical mass shifts. The differential chemical mass shift which combined the shifts from forward and reverse scans doubled the amount of chemical shift, e.g., 0.077 Th between o- and p-xylene, enough for identification of the type of isomer without using an additional ion mobility spectrometer. The feature of equal and opposite chemical mass shifts also allowed to null out the chemical mass shift by calculating the mean m/z value between the two opposite scans and remove or reduce the mass error caused by chemical mass shift. Graphical Abstract ᅟ.

Chemical Mass Shifts in a Digital Linear Ion Trap as Analytical Identity of o-, m-, and p-Xylene

NASA Astrophysics Data System (ADS)

Sun, Lulu; Xue, Bing; Huang, Zhengxu; Cheng, Ping; Ma, Li; Ding, Li; Zhou, Zhen

2018-04-01

Chemical mass shifts between isomeric ions of o-, m-, and p-xylene were measured using a digital linear ion trap, and the directions and values of the shifts were found to be correlated to the collision cross sections of the isomers. Both forward and reverse scans were used and the chemical shifts for each pair of isomers in scans of opposite directions were in opposite signs. Using different voltage settings (namely the voltage dividing ratio-VDR) of the ion trap allows adding high order field components in the quadrupole field and results in larger chemical mass shifts. The differential chemical mass shift which combined the shifts from forward and reverse scans doubled the amount of chemical shift, e.g., 0.077 Th between o- and p-xylene, enough for identification of the type of isomer without using an additional ion mobility spectrometer. The feature of equal and opposite chemical mass shifts also allowed to null out the chemical mass shift by calculating the mean m/z value between the two opposite scans and remove or reduce the mass error caused by chemical mass shift. [Figure not available: see fulltext.

Coping strategies and social support needs of experienced and inexperienced nurses performing shiftwork.

PubMed

Gifkins, Jane; Loudoun, Rebecca; Johnston, Amy

2017-12-01

The aim of this investigation was to compare perceptions of nurses exposed to short or longer term shift work and their experiences working under this type of scheduling. Shift work is a crucial component of nurses' working lives, ensuring continuous care for patients. This study fills a research gap around the personal experiences of shift working nurses and the strategies used to manage the impacts of shift work. Qualitative case study design. Constructivist methodology, including in-depth semi-structured interviews conducted in 2015, was used for the study. Iterative review and inductive analysis of transcripts from nine recently graduated nurses and twelve experienced nurses enabled identification and verification of key themes. Three main areas of difference between new and experienced nurses relating to shift work challenges in a nursing environment emerged: perceptions about the utility of working in shifts, coping strategies and social support at home and work. Most experienced nurses found shift work advantageous, especially those with dependents. Coping strategies included flexible shift arrangements in both groups. Experienced nurses detailed the importance of support from family and friends while inexperienced nurses described feeling disconnected from social supports. Experienced nurses cited a lack of support from nursing managers as problematic. Findings suggest shift selection mitigated challenges of shift work for both inexperienced and experienced nurses, indicating autonomous roster selection is critical. Similarly, social support at work from senior nurses and management and at home played an important role in nurses' coping. © 2017 John Wiley & Sons Ltd.

Experiments Using Cell Phones in Physics Classroom Education: The Computer-Aided g Determination

NASA Astrophysics Data System (ADS)

Vogt, Patrik; Kuhn, Jochen; Müller, Sebastian

2011-09-01

This paper continues the collection of experiments that describe the use of cell phones as experimental tools in physics classroom education.1-4 We describe a computer-aided determination of the free-fall acceleration g using the acoustical Doppler effect. The Doppler shift is a function of the speed of the source. Since a free-falling objects speed is changing linearly with time, the Doppler shift is also changing with time. It is possible to measure this shift using software that is both easy to use and readily available. Students will use the time-dependency of the Doppler shift to experimentally determine the acceleration due to gravity by using a cell phone as a freely falling object emitting a sound with constant frequency.

Influence of rate of change of frequency on the overall pitch of frequency-modulated tones.

PubMed

Gockel, H; Moore, B C; Carlyon, R P

2001-02-01

The mechanism(s) determining pitch may assign less weight to portions of a sound where the frequency is changing rapidly. The present experiments explored the possible effect of this on the overall pitch of frequency-modulated sounds. Pitch matches were obtained between an adjustable unmodulated sinusoid and a sinusoidal carrier that was frequency modulated using a highly asymmetric function with the form of a repeating U or inverted U shaped function. The amplitude was constant during the 400-ms presentation time of each stimulus, except for 10-ms raised-cosine onset and offset ramps. In experiment 1, the carrier level was 50 dB SPL and the geometric mean of the instantaneous frequency of the modulated carrier, fc, was either 0.5, 1, 2, or 8 kHz. The modulation rate (fm) was 5, 10, or 20 Hz. The overall depth (maximum to minimum) of the FM was 8% of fc. For all carrier frequencies, the matched frequency was shifted away from the mean carrier frequency, downwards for the U shaped function stimuli and upwards for the repeated inverted U shaped function stimuli. The shift was typically slightly greater than 1% of fc, and did not vary markedly with fc. The effect of fm was small, but there was a trend for the shifts to decrease with increasing fm for fc = 0.5 kHz and to increase with increasing fm for fc = 2 kHz. In experiment 2, the carrier level was reduced to 20 dB SL and matches were obtained only for fc = 2 kHz. Shifts in matched frequency of about 1% were still observed, but the trend for the shifts to increase with increasing fm no longer occurred. In experiment 3, matches were obtained for a 4-kHz carrier at 50 dB SPL. Shifts of about 1% again occurred, which did not vary markedly with fm. The shifts in matched frequency observed in all three experiments are not predicted by models based on the amplitude- or intensity-weighted average of instantaneous frequency (EWAIF or IWAIF). The shifts (and the pitch shifts observed earlier for two-tone complexes and for stimuli with simultaneous AM and FM) are consistent with a model based on the assumption that the overall pitch of a frequency-modulated sound is determined from a weighted average of period estimates, with the weight attached to a given estimate being inversely related to the short-term rate of change of period and directly related to a compressive function of the amplitude.

Applications of statistical and atomic physics to the spectral line broadening and stock markets

NASA Astrophysics Data System (ADS)

Volodko, Dmitriy

The purpose of this investigation is the application of time correlation function methodology on the theoretical research of the shift of hydrogen and hydrogen-like spectral lines due to electrons and ions interaction with the spectral line emitters-dipole ionic-electronic shift (DIES) and the describing a behavior of stock-market in terms of a simple physical model simulation which obeys Levy statistical distribution---the same as that of the real stock-market index. Using Generalized Theory of Stark broadening of electrons in plasma we discovered a new source of the shift of hydrogen and hydrogen-like spectral lines that we called a dipole ionic-electronic shift (DIES). This shift results from the indirect coupling of electron and ion microfields in plasmas which is facilitated by the radiating atom/ion. We have shown that the DIES, unlike all previously known shifts, is highly nonlinear and has a different sign for different ranges of plasma parameters. The most favorable conditions for observing the DIES correspond to plasmas of high densities, but of relatively low temperature. For the Balmer-alpha line of hydrogen with the most favorable observational conditions Ne > 1018 cm-3, T < 2 eV, the DIES has been already confirmed experimentally. Based on the study of the time correlations and of the probability distribution of fluctuations in the stock market, we developed a relatively simple physical model, which simulates the Dow Jones Industrials index and makes short-term (a couple of days) predictions of its trend.

Sources of Cognitive Inflexibility in Set-Shifting Tasks: Insights into Developmental Theories from Adult Data

ERIC Educational Resources Information Center

Dick, Anthony Steven

2012-01-01

Two experiments examined processes underlying cognitive inflexibility in set-shifting tasks typically used to assess the development of executive function in children. Adult participants performed a Flexible Item Selection Task (FIST) that requires shifting from categorizing by one dimension (e.g., color) to categorizing by a second orthogonal…

Neural Correlates of Stimulus Response and Stimulus Outcome Shifting in Healthy Participants and MS Patients

ERIC Educational Resources Information Center

Hildebrandt, Helmut; Fink, Frauke; Eling, Paul; Stuke, Heiner; Klein, Jan; Lentschig, Markus; Kastrup, Andreas; Thiel, Christiane; Breckel, Thomas

2013-01-01

Introduction: Adaptation to changing situations can be mediated by two strategies: (1) Evaluation of a "response" and (2) Evaluation of "outcome" values in relation to objects. Previous studies indicate that response shifting is associated with a network comprising the left frontal cortex and parietal cortex connected by the superior longitudinal…

Physiological and behavioral effects of tilt-induced body fluid shifts

NASA Technical Reports Server (NTRS)

Parker, D. E.; Tjernstrom, O.; Ivarsson, A.; Gulledge, W. L.; Poston, R. L.

1983-01-01

This paper addresses the 'fluid shift theory' of space motion sickness. The primary purpose of the research was the development of procedures to assess individual differences in response to rostral body fluid shifts on earth. Experiment I examined inner ear fluid pressure changes during head-down tilt in intact human beings. Tilt produced reliable changes. Differences among subjects and between ears within the same subject were observed. Experiment II examined auditory threshold changes during tilt. Tilt elicited increased auditory thresholds, suggesting that sensory depression may result from increased inner ear fluid pressure. Additional observations on rotation magnitude estimation during head-down tilt, which indicate that rostral fluid shifts may depress semicircular canal activity, are briefly described. The results of this research suggest that the inner ear pressure and auditory threshold shift procedures could be used to assess individual differences among astronauts prior to space flight. Results from the terrestrial observations could be related to reported incidence/severity of motion sickness in space and used to evaluate the fluid shift theory of space motion sickness.

Impact of 12h shift patterns in nursing: a scoping review.

PubMed

Harris, Ruth; Sims, Sarah; Parr, Jenny; Davies, Nigel

2015-02-01

To provide a comprehensive scoping review of evidence of the impact and effectiveness of 12h shifts in the international nursing literature, supplemented by a review of evidence in other, non-nursing related industries. A search of the academic literature was undertaken in electronic databases (AMED, MEDLINE, CINAHL, PsychInfo, Scopus, HMIC, the Cochrane Library, Business Source Premier, Econ Lit, ASSIA and Social Policy and Practice). A total of 158 potentially relevant nursing research papers and reviews were published between 1973 and 2014. Two reviewers independently reviewed the articles, leaving 85 primary research studies and 10 review papers in the nursing field to be included in the scoping review. Thirty-one relevant primary research papers and reviews were also identified in the non-nursing related industries literature. Research into 12h nursing shifts fell within five broad themes: 'risks to patients', 'patient experience', 'risks to staff', 'staff experience' and 'impact on the organisation of work'. There was inconclusive evidence of the effects of 12h shift patterns in all five themes, with some studies demonstrating positive impacts and others negative or no impacts. This also mirrors the evidence in other, non-nursing related industries. The quality of research reviewed is generally weak and most studies focus on the risks, experience and work/life balance for staff, with few addressing the impact on patient outcomes and experience of care or work productivity. There is insufficient evidence to justify the widespread implementation or withdrawal of 12h shifts in nursing. It is not clearly understood where there are real benefits and where there are real and unacceptable risks to patients and staff. More research focusing on the impact of 12h nursing shifts on patient safety and experience of care and on the long term impact on staff and work organisation is required. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of night-shift and napping at work on urinary melatonin, 17-β-estradiol and clock gene expression in pre-menopausal nurses.

PubMed

Bracci, M; Copertaro, A; Manzella, N; Staffolani, S; Strafella, E; Nocchi, L; Barbaresi, M; Copertaro, B; Rapisarda, V; Valentino, M; Santarelli, L

2013-01-01

Night-workers experience disruption of the sleep-wake cycle and light at night which may increase breast cancer risk by suppressing the nocturnal melatonin surge, resulting in higher levels of circulating estrogens. Night-work may also deregulate peripheral clock genes which have been found to be altered in breast cancer. This study investigated urinary 6-sulfatoxymelatonin (aMT6s), serum 17-beta-estradiol levels in premenopausal shift nurses at the end of the night-shift compared to a control group of daytime nurses. Peripheral clock gene expression in lymphocytes were also investigated. All participants were sampled in the follicular phase of the menstrual cycle. The effect of nurses’ ability to take a short nap during the night-shift was also explored. The shift-work group had significantly lower aMT6s levels than daytime nurses independently of a nap. Night-shift napping significantly influences 17-beta-estradiol levels resulting in higher outcomes in nurses who do not take a nap compared to napping group and daytime workers. Peripheral clock genes expression investigated was not significantly different among the groups. Our findings suggest that shift nurses experience changes in aMT6s levels after a night-shift. Napping habits influence 17-beta-estradiol levels at the end of a night-shift. These findings might be related to the increased cancer risk reported in night-shift workers and suggest that a short nap during night-shifts may exert a positive effect.

Northern range expansion of European populations of the wasp spider Argiope bruennichi is associated with global warming-correlated genetic admixture and population-specific temperature adaptations.

PubMed

Krehenwinkel, Henrik; Tautz, Diethard

2013-04-01

Poleward range expansions are observed for an increasing number of species, which may be an effect of global warming during the past decades. However, it is still not clear in how far these expansions reflect simple geographical shifts of species ranges, or whether new genetic adaptations play a role as well. Here, we analyse the expansion of the wasp spider Argiope bruennichi into Northern Europe during the last century. We have used a range-wide sampling of contemporary populations and historical specimens from museums to trace the phylogeography and genetic changes associated with the range shift. Based on the analysis of mitochondrial, microsatellite and SNP markers, we observe a higher level of genetic diversity in the expanding populations, apparently due to admixture of formerly isolated lineages. Using reciprocal transplant experiments for testing overwintering tolerance, as well as temperature preference and tolerance tests in the laboratory, we find that the invading spiders have possibly shifted their temperature niche. This may be a key adaptation for survival in Northern latitudes. The museum samples allow a reconstruction of the invasion's genetic history. A first, small-scale range shift started around 1930, in parallel with the onset of global warming. A more massive invasion of Northern Europe associated with genetic admixture and morphological changes occurred in later decades. We suggest that the latter range expansion into far Northern latitudes may be a consequence of the admixture that provided the genetic material for adaptations to new environmental regimes. Hence, global warming could have facilitated the initial admixture of populations and this resulted in genetic lineages with new habitat preferences. © 2013 Blackwell Publishing Ltd.

Spectroscopic study of trivalent praseodymium in barium yttrium fluoride

NASA Astrophysics Data System (ADS)

Bowlby, Brian Edward

1998-09-01

This work investigates the spectroscopic properties of trivalent praseodymium (Pr3+) in barium yttrium fluoride (BaY2F8). Two doping concentrations were studied: BaY2F8:Pr3+ (.3%) and BaY2F8:Pr3+ (1%). Absorption spectra were taken at 77K and 300K and these were then used to calculate the Judd-Ofelt coefficients for both samples. These coefficients were then used to calculate the theoretical lifetimes and radiative branching ratios for all manifolds. Continuous luminescence spectra and lifetime measurements were also performed, and from these, experimentally determined values for the branching ratio and lifetimes were determined. These were then compared to their theoretical counterparts. It was found that while the theory gave values that were qualitatively correct, the quantitative correlation between theory and experiment shows the complexity of the physical reality and the difficulty of synthesizing an encompassing theoretical model. Absorption spectra and continuous luminescence spectra were also used to determine the energy levels of all manifolds in both samples. A total of 59 energy levels in 11 manifolds were identified in the BaY2F8:Pr3+ (1%) sample, while 51 levels in 11 manifolds were identified in the BaY2F8:Pr3+ (.3%) sample. Finally, the effects of temperature on the line width and line position for several radiative transitions was studied. It was found that while most transitions exhibited the expected broadening and shifting towards longer wavelengths at higher temperatures (a 'red shift'), the transition from the 3P0 level to the 3H4 ground state showed a shift towards shorter wavelengths at higher temperature (a 'blue shift'). Again this highlights the complexity of the ion- host interaction.

Elymus repens biomass allocation and acquisition as affected by light and nutrient supply and companion crop competition.

PubMed

Ringselle, Björn; Prieto-Ruiz, Inés; Andersson, Lars; Aronsson, Helena; Bergkvist, Göran

2017-02-01

Competitive crops are a central component of resource-efficient weed control, especially for problematic perennial weeds such as Elymus repens Competition not only reduces total weed biomass, but denial of resources can also change the allocation pattern - potentially away from the underground storage organs that make perennial weeds difficult to control. Thus, the competition mode of crops may be an important component in the design of resource-efficient cropping systems. Our aim was to determine how competition from companion crops with different modes of competition affect E. repens biomass acquisition and allocation and discuss that in relation to how E. repens responds to different levels of light and nutrient supply. Greenhouse experiments were conducted with E. repens growing in interspecific competition with increasing density of perennial ryegrass or red clover, or growing at three levels of both light and nutrient supply. Elymus repens total biomass decreased with increasing biomass of the companion crop and the rate of decrease was higher with red clover than with perennial ryegrass, particularly for E. repens rhizome biomass. A reduced nutrient supply shifted E. repens allocation towards below-ground biomass while a reduced light supply shifted it towards shoot biomass. Red clover caused no change in E. repens allocation pattern, while ryegrass mostly shifted the allocation towards below-ground biomass, but the change was not correlated with ryegrass biomass. The companion crop mode of competition influences both the suppression rate of E. repens biomass acquisition and the likelihood of shifts in E. repens biomass allocation. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An investigation of care-based vs. rule-based morality in frontotemporal dementia, Alzheimer's disease, and healthy controls.

PubMed

Carr, Andrew R; Paholpak, Pongsatorn; Daianu, Madelaine; Fong, Sylvia S; Mather, Michelle; Jimenez, Elvira E; Thompson, Paul; Mendez, Mario F

2015-11-01

Behavioral changes in dementia, especially behavioral variant frontotemporal dementia (bvFTD), may result in alterations in moral reasoning. Investigators have not clarified whether these alterations reflect differential impairment of care-based vs. rule-based moral behavior. This study investigated 18 bvFTD patients, 22 early onset Alzheimer's disease (eAD) patients, and 20 healthy age-matched controls on care-based and rule-based items from the Moral Behavioral Inventory and the Social Norms Questionnaire, neuropsychological measures, and magnetic resonance imaging (MRI) regions of interest. There were significant group differences with the bvFTD patients rating care-based morality transgressions less severely than the eAD group and rule-based moral behavioral transgressions more severely than controls. Across groups, higher care-based morality ratings correlated with phonemic fluency on neuropsychological tests, whereas higher rule-based morality ratings correlated with increased difficulty set-shifting and learning new rules to tasks. On neuroimaging, severe care-based reasoning correlated with cortical volume in right anterior temporal lobe, and rule-based reasoning correlated with decreased cortical volume in the right orbitofrontal cortex. Together, these findings suggest that frontotemporal disease decreases care-based morality and facilitates rule-based morality possibly from disturbed contextual abstraction and set-shifting. Future research can examine whether frontal lobe disorders and bvFTD result in a shift from empathic morality to the strong adherence to conventional rules. Published by Elsevier Ltd.

An Investigation of Care-Based vs. Rule-Based Morality in Frontotemporal Dementia, Alzheimer’s Disease, and Healthy Controls

PubMed Central

Carr, Andrew R.; Paholpak, Pongsatorn; Daianu, Madelaine; Fong, Sylvia S.; Mather, Michelle; Jimenez, Elvira E.; Thompson, Paul; Mendez, Mario F.

2015-01-01

Behavioral changes in dementia, especially behavioral variant frontotemporal dementia (bvFTD), may result in alterations in moral reasoning. Investigators have not clarified whether these alterations reflect differential impairment of care-based vs. rule-based moral behavior. This study investigated 18 bvFTD patients, 22 early onset Alzheimer’s disease (eAD) patients, and 20 healthy age-matched controls on care-based and rule-based items from the Moral Behavioral Inventory and the Social Norms Questionnaire, neuropsychological measures, and magnetic resonance imaging (MRI) regions of interest. There were significant group differences with the bvFTD patients rating care-based morality transgressions less severely than the eAD group and rule-based moral behavioral transgressions more severely than controls. Across groups, higher care-based morality ratings correlated with phonemic fluency on neuropsychological tests, whereas higher rule-based morality ratings correlated with increased difficulty set-shifting and learning new rules to tasks. On neuroimaging, severe care-based reasoning correlated with cortical volume in right anterior temporal lobe, and rule-based reasoning correlated with decreased cortical volume in the right orbitofrontal cortex. Together, these findings suggest that frontotemporal disease decreases care-based morality and facilitates rule-based morality possibly from disturbed contextual abstraction and set-shifting. Future research can examine whether frontal lobe disorders and bvFTD result in a shift from empathic morality to the strong adherence to conventional rules. PMID:26432341

Effects of hydrogen bonding on amide-proton chemical shift anisotropy in a proline-containing model peptide

NASA Astrophysics Data System (ADS)

Pichumani, Kumar; George, Gijo; Hebbar, Sankeerth; Chatterjee, Bhaswati; Raghothama, Srinivasarao

2015-05-01

Longitudinal relaxation due to cross-correlation between dipolar (1HN-1Hα) and amide-proton chemical shift anisotropy (1HN CSA) has been measured in a model tripeptide Piv-LPro-LPro-LPhe-OMe. The peptide bond across diproline segment is known to undergo cis/trans isomerization and only in the cis form does the lone Phe amide-proton become involved in intramolecular hydrogen bonding. The strength of the cross correlated relaxation interference is found to be significantly different between cis and trans forms, and this difference is shown as an influence of intramolecular hydrogen bonding on the amide-proton CSA.

Cognitive flexibility correlates with gambling severity in young adults.

PubMed

Leppink, Eric W; Redden, Sarah A; Chamberlain, Samuel R; Grant, Jon E

2016-10-01

Although gambling disorder (GD) is often characterized as a problem of impulsivity, compulsivity has recently been proposed as a potentially important feature of addictive disorders. The present analysis assessed the neurocognitive and clinical relationship between compulsivity on gambling behavior. A sample of 552 non-treatment seeking gamblers age 18-29 was recruited from the community for a study on gambling in young adults. Gambling severity levels included both casual and disordered gamblers. All participants completed the Intra/Extra-Dimensional Set Shift (IED) task, from which the total adjusted errors were correlated with gambling severity measures, and linear regression modeling was used to assess three error measures from the task. The present analysis found significant positive correlations between problems with cognitive flexibility and gambling severity (reflected by the number of DSM-5 criteria, gambling frequency, amount of money lost in the past year, and gambling urge/behavior severity). IED errors also showed a positive correlation with self-reported compulsive behavior scores. A significant correlation was also found between IED errors and non-planning impulsivity from the BIS. Linear regression models based on total IED errors, extra-dimensional (ED) shift errors, or pre-ED shift errors indicated that these factors accounted for a significant portion of the variance noted in several variables. These findings suggest that cognitive flexibility may be an important consideration in the assessment of gamblers. Results from correlational and linear regression analyses support this possibility, but the exact contributions of both impulsivity and cognitive flexibility remain entangled. Future studies will ideally be able to assess the longitudinal relationships between gambling, compulsivity, and impulsivity, helping to clarify the relative contributions of both impulsive and compulsive features. Copyright © 2016 Elsevier Ltd. All rights reserved.

CE: Original Research: Napping on the Night Shift: A Two-Hospital Implementation Project.

PubMed

Geiger-Brown, Jeanne; Sagherian, Knar; Zhu, Shijun; Wieroniey, Margaret Ann; Blair, Lori; Warren, Joan; Hinds, Pamela S; Szeles, Rose

2016-05-01

: Nurses who work the night shift often experience high levels of sleepiness. Napping has been adopted as an effective countermeasure to sleepiness and fatigue in other safety-sensitive industries, but has not had widespread acceptance in nursing. To assess the barriers to successful implementation of night-shift naps and to describe the nap experiences of night-shift nurses who took naps. In this two-hospital pilot implementation project, napping on the night shift was offered to six nursing units for which the executive nursing leadership had given approval. Unit nurse managers' approval was sought, and where granted, further explanation was given to the unit's staff nurses. A nap experience form, which included the Karolinska Sleepiness Scale, was used to assess pre-nap sleepiness level, nap duration and perceived sleep experience, post-nap sleep inertia, and the perceived helpfulness of the nap. Nurse managers and staff nurses were also interviewed at the end of the three-month study period. Successful implementation occurred on only one of the six units, with partial success seen on a second unit. Barriers primarily occurred at the point of seeking the unit nurse managers' approval. On the successful unit, 153 30-minutes naps were taken during the study period. A high level of sleepiness was present at the beginning of 44% of the naps. For more than half the naps, nurses reported achieving either light (43%) or deep (14%) sleep. Sleep inertia was rare. The average score of helpfulness of napping was high (7.3 on a 1-to-10 scale). Nurses who napped reported being less drowsy while driving home after their shift. These data suggest that when barriers to napping are overcome, napping on the night shift is feasible and can reduce nurses' workplace sleepiness and drowsy driving on the way home. Addressing nurse managers' perceptions of and concerns about napping may be essential to successful implementation.

Differential effects of removing the glucose or saccharin components of a glucose-saccharin mixture in a successive negative contrast paradigm.

PubMed

Mitchell, Colin P; Flaherty, Charles F

2005-03-31

When rats experience an unexpected decrease in reward value, e.g., from 32% sucrose to 4% sucrose, consummatory behavior abruptly decreases to a level below control subjects that only experience the lesser reward, a phenomenon known as Successive Negative Contrast (SNC). In food deprived rats experiencing downshifts in sucrose concentration, SNC dissipates in 3-4 days, as consummatory behavior in shifted rats recovers to the level of unshifted controls. In Experiment 1 food deprived rats that were given 5 min daily access to a 2% glucose-0.15% saccharin mixture, and subsequently shifted to 2% glucose alone, displayed a dramatic SNC effect relative to rats that only received 2% glucose. This SNC effect was primarily manifested as a decrease in the number of consummatory bursts initiated. Interestingly, intake failed to recover to control levels during eight daily postshift sessions. However, in Experiment 2 subjects that were shifted from the same glucose-saccharin mixture to 0.15% saccharin alone failed to show SNC rather, intake fell to the level of control animals which only received 0.15% saccharin. The data from Experiment 1, in conjunction with previous studies utilizing non-deprived rats, quinine adulteration, or shifts from sucrose to saccharin, show that reductions in taste value can produce contrast effects, but suggest that a threshold caloric value is necessary for recovery. The data from Experiment 2 may suggest that saccharin and glucose do not contribute equally to the enhanced palatability of the mixture.

Adaptation to Shift Work: Physiologically Based Modeling of the Effects of Lighting and Shifts’ Start Time

PubMed Central

Postnova, Svetlana; Robinson, Peter A.; Postnov, Dmitry D.

2013-01-01

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers’ sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers’ adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21∶00 instead of 00∶00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters. PMID:23308206

A Three-Dimensional DOSY HMQC Experiment for the High-Resolution Analysis of Complex Mixtures

NASA Astrophysics Data System (ADS)

Barjat, Hervé; Morris, Gareth A.; Swanson, Alistair G.

1998-03-01

A three-dimensional experiment is described in which NMR signals are separated according to their proton chemical shift,13C chemical shift, and diffusion coefficient. The sequence is built up from a stimulated echo sequence with bipolar field gradient pulses and a conventional decoupled HMQC sequence. Results are presented for a model mixture of quinine, camphene, and geraniol in deuteriomethanol.

Do End-of-Rotation and End-of-Shift Assessments Inform Clinical Competency Committees’ (CCC) Decisions?

PubMed Central

Regan, Linda; Cope, Leslie; Omron, Rodney; Bright, Leah; Bayram, Jamil D.

2018-01-01

Introduction Clinical Competency Committees (CCC) require reliable, objective data to inform decisions regarding assignment of milestone proficiency levels, which must be reported to the Accreditation Council for Graduate Medical Education. After the development of two new assessment methods, the end-of-shift (EOS) assessment and the end-of-rotation (EOR) assessment, we sought to evaluate their performance. We report data on the concordance between these assessments, as well as how each informs the final proficiency level determined in biannual CCC meetings. We hypothesized that there would be a high concordance level between the two assessment methods, including concordance of both the EOS and EOR with the final proficiency level designation by the CCC. Methods The residency program is an urban academic four-year emergency medicine residency with 48 residents. After their shifts in the emergency department (ED), residents handed out EOS assessment forms asking about individual milestones from 15 subcompetencies to supervising physicians, as well as triggered electronic EOR-doctor (EORd) assessments to supervising doctors and EOR-nurse (EORn) to nurses they had worked with after each two-week ED block. EORd assessments contained the full proficiency level scale from 16 subcompetencies, while EORn assessments contained four subcompetencies. Data reports were generated after each six-month assessment period and data was aggregated. We calculated Spearman’s rank order correlations for correlations between assessment types and between assessments and final CCC proficiency levels. Results Over 24 months, 5,234 assessments were completed. The strongest correlations with CCC proficiency levels were the EORd for the immediate six-month assessment period prior (rs 0.71–0.84), and the CCC proficiency levels from the previous six-months (rs 0.83–0.92). EOS assessments had weaker correlations (rs 0.49 to 0.62), as did EORn (rs 0.4 to 0.73). Conclusion End-of-rotation assessments completed by supervising doctors are most highly correlated with final CCC proficiency level designations, while end-of-shift assessments and end-of-rotation assessments by nurses did not correlate strongly with final CCC proficiency levels, both with overestimation of levels noted. Every level of proficiency the CCC assigned appears to be highly correlated with the designated level in the immediate six-month period, perhaps implying CCC members are biased by previous level assignments. PMID:29383066

Do End-of-Rotation and End-of-Shift Assessments Inform Clinical Competency Committees' (CCC) Decisions?

PubMed

Regan, Linda; Cope, Leslie; Omron, Rodney; Bright, Leah; Bayram, Jamil D

2018-01-01

Clinical Competency Committees (CCC) require reliable, objective data to inform decisions regarding assignment of milestone proficiency levels, which must be reported to the Accreditation Council for Graduate Medical Education. After the development of two new assessment methods, the end-of-shift (EOS) assessment and the end-of-rotation (EOR) assessment, we sought to evaluate their performance. We report data on the concordance between these assessments, as well as how each informs the final proficiency level determined in biannual CCC meetings. We hypothesized that there would be a high concordance level between the two assessment methods, including concordance of both the EOS and EOR with the final proficiency level designation by the CCC. The residency program is an urban academic four-year emergency medicine residency with 48 residents. After their shifts in the emergency department (ED), residents handed out EOS assessment forms asking about individual milestones from 15 subcompetencies to supervising physicians, as well as triggered electronic EOR-doctor (EORd) assessments to supervising doctors and EOR-nurse (EORn) to nurses they had worked with after each two-week ED block. EORd assessments contained the full proficiency level scale from 16 subcompetencies, while EORn assessments contained four subcompetencies. Data reports were generated after each six-month assessment period and data was aggregated. We calculated Spearman's rank order correlations for correlations between assessment types and between assessments and final CCC proficiency levels. Over 24 months, 5,234 assessments were completed. The strongest correlations with CCC proficiency levels were the EORd for the immediate six-month assessment period prior (r s 0.71-0.84), and the CCC proficiency levels from the previous six-months (r s 0.83-0.92). EOS assessments had weaker correlations (r s 0.49 to 0.62), as did EORn (r s 0.4 to 0.73). End-of-rotation assessments completed by supervising doctors are most highly correlated with final CCC proficiency level designations, while end-of-shift assessments and end-of-rotation assessments by nurses did not correlate strongly with final CCC proficiency levels, both with overestimation of levels noted. Every level of proficiency the CCC assigned appears to be highly correlated with the designated level in the immediate six-month period, perhaps implying CCC members are biased by previous level assignments.

Comparison of methods applied in photoinduced transient spectroscopy to determining the defect center parameters: The correlation procedure and the signal analysis based on inverse Laplace transformation

NASA Astrophysics Data System (ADS)

Suproniuk, M.; Pawłowski, M.; Wierzbowski, M.; Majda-Zdancewicz, E.; Pawłowski, Ma.

2018-04-01

The procedure for determination of trap parameters by photo-induced transient spectroscopy is based on the Arrhenius plot that illustrates a thermal dependence of the emission rate. In this paper, we show that the Arrhenius plot obtained by the correlation method is shifted toward lower temperatures as compared to the one obtained with the inverse Laplace transformation. This shift is caused by the model adequacy error of the correlation method and introduces errors to a calculation procedure of defect center parameters. The effect is exemplified by comparing the results of the determination of trap parameters with both methods based on photocurrent transients for defect centers observed in tin-doped neutron-irradiated silicon crystals and in gallium arsenide grown with the Vertical Gradient Freeze method.

Development of multicomponent hybrid density functional theory with polarizable continuum model for the analysis of nuclear quantum effect and solvent effect on NMR chemical shift.

PubMed

Kanematsu, Yusuke; Tachikawa, Masanori

2014-04-28

We have developed the multicomponent hybrid density functional theory [MC_(HF+DFT)] method with polarizable continuum model (PCM) for the analysis of molecular properties including both nuclear quantum effect and solvent effect. The chemical shifts and H/D isotope shifts of the picolinic acid N-oxide (PANO) molecule in chloroform and acetonitrile solvents are applied by B3LYP electron exchange-correlation functional for our MC_(HF+DFT) method with PCM (MC_B3LYP/PCM). Our MC_B3LYP/PCM results for PANO are in reasonable agreement with the corresponding experimental chemical shifts and isotope shifts. We further investigated the applicability of our method for acetylacetone in several solvents.

Study of chemical shift in Kα, Kβ1,3 and Kβ// X-ray emission lines of 37Rb compounds with WDXRF

NASA Astrophysics Data System (ADS)

Kainth, Harpreet Singh; Singh, Ranjit; Singh, Tejbir; Mehta, D.; Shahi, J. S.; Kumar, Sanjeev

2018-05-01

The positive and negative chemical shifts in Kα, Kβ1,3 and Kβ// X-ray emission lines of rubidium compounds were measured with high resolution WDXRF spectrometer. The measured energy shifts in Kα emission lines ranges from -2.95 eV to -3.64 eV, Kβ1,3 emission lines ranges from 1.16 eV to 1.32 eV and Kβ// emission lines ranges from 1.31 eV to 4.36 eV respectively. In the present work, it has been found that chemical shift in Kβ// X-ray emission lines were found to be larger than Kα and Kβ1,3 X-ray emission lines. To find the cause of chemical shift, various factors like effective charge, line intensity ratio, bond length and electro-negativity were calculated and correlated with the chemical shift.

Midlatitude Cloud Shifts, Their Primary Link to the Hadley Cell, and Their Diverse Radiative Effects

NASA Technical Reports Server (NTRS)

Tselioudis, George; Lipat, Bernard R.; Konsta, Dimitra; Grise, Kevin M.; Polvani, Lorenzo M.

2016-01-01

We investigate the interannual relationship among clouds, their radiative effects, and two key indices of the atmospheric circulation: the latitudinal positions of the Hadley cell edge and the midlatitude jet. From reanalysis data and satellite observations, we find a clear and consistent relationship between the width of the Hadley cell and the high cloud field, statistically significant in nearly all regions and seasons. In contrast, shifts of the midlatitude jet correlate significantly with high cloud shifts only in the North Atlantic region during the winter season. While in that region and season poleward high cloud shifts are associated with shortwave radiative warming, over the Southern Oceans during all seasons they are associated with shortwave radiative cooling. Finally, a trend analysis reveals that poleward high cloud shifts observed over the 1983-2009 period are more likely related to Hadley cell expansion, rather than poleward shifts of the midlatitude jets.

Density Functional Calculations for Prediction of 57Fe Mössbauer Isomer Shifts and Quadrupole Splittings in β-Diketiminate Complexes

PubMed Central

2017-01-01

The relative ease of Mössbauer spectroscopy and of density functional theory (DFT) calculations encourages the use of Mössbauer parameters as a validation method for calculations, and the use of calculations as a double check on crystallographic structures. A number of studies have proposed correlations between the computationally determined electron density at the iron nucleus and the observed isomer shift, but deviations from these correlations in low-valent iron β-diketiminate complexes encouraged us to determine a new correlation for these compounds. The use of B3LYP/def2-TZVP in the ORCA platform provides an excellent balance of accuracy and speed. We provide here not only this new correlation and a clear guide to its use but also a systematic analysis of the limitations of this approach. We also highlight the impact of crystallographic inaccuracies, DFT model truncation, and spin states, with intent to assist experimentalists to use Mössbauer spectroscopy and calculations together. PMID:28691111

Geophysical variables and behavior: XXIII. Relations between UFO reports within the Uinta Basin and local seismicity.

PubMed

Persinger, M A; Derr, J S

1985-02-01

A strong temporal correlation was found between the numbers of reports of UFOs (unidentified flying objects) and nearby seismic activity within the Uinta Basin for the year 1967. The numbers of UFO reports per month during this classic UFO flap were correlated 0.80 with the sum of the earthquake magnitudes per month for events within 150 km of the report area. Numbers of UFO reports were not correlated significantly with earthquake activity at distances greater than 150 km but less than 250 km away. The strongest correlation occurred between UFO reports and nearby seismic activity within the same month but not for previous or consequent months. Close scrutiny of daily shifts in epicenters and reports of UFOs indicate that they occurred when the locus of successive epicenters shifted across the area. These analyses were interpreted as support for the existence of strain fields whose movements generate natural phenomena that are reported as UFOs.

Lead-lag cross-sectional structure and detection of correlated anticorrelated regime shifts: Application to the volatilities of inflation and economic growth rates

NASA Astrophysics Data System (ADS)

Zhou, Wei-Xing; Sornette, Didier

2007-07-01

We have recently introduced the “thermal optimal path” (TOP) method to investigate the real-time lead-lag structure between two time series. The TOP method consists in searching for a robust noise-averaged optimal path of the distance matrix along which the two time series have the greatest similarity. Here, we generalize the TOP method by introducing a more general definition of distance which takes into account possible regime shifts between positive and negative correlations. This generalization to track possible changes of correlation signs is able to identify possible transitions from one convention (or consensus) to another. Numerical simulations on synthetic time series verify that the new TOP method performs as expected even in the presence of substantial noise. We then apply it to investigate changes of convention in the dependence structure between the historical volatilities of the USA inflation rate and economic growth rate. Several measures show that the new TOP method significantly outperforms standard cross-correlation methods.

On the nature of a glassy state of matter in a hydrated protein: Relation to protein function.

PubMed

Teeter, M M; Yamano, A; Stec, B; Mohanty, U

2001-09-25

Diverse biochemical and biophysical experiments indicate that all proteins, regardless of size or origin, undergo a dynamic transition near 200 K. The cause of this shift in dynamic behavior, termed a "glass transition," and its relation to protein function are important open questions. One explanation postulated for the transition is solidification of correlated motions in proteins below the transition. We verified this conjecture by showing that crambin's radius of gyration (Rg) remains constant below approximately 180 K. We show that both atom position and dynamics of protein and solvent are physically coupled, leading to a novel cooperative state. This glassy state is identified by negative slopes of the Debye-Waller (B) factor vs. temperature. It is composed of multisubstate side chains and solvent. Based on generalization of Adam-Gibbs' notion of a cooperatively rearranging region and decrease of the total entropy with temperature, we calculate the slope of the Debye-Waller factor. The results are in accord with experiment.