Training Planning and Working Memory in Third Graders

ERIC Educational Resources Information Center

Goldin, Andrea Paula; Segretin, Maria Soledad; Hermida, Maria Julia; Paz, Luciano; Lipina, Sebastian Javier; Sigman, Mariano

2013-01-01

Working memory and planning are fundamental cognitive skills supporting fluid reasoning. We show that 2 games that train working memory and planning skills in school-aged children promote transfer to 2 different tasks: an attentional test and a fluid reasoning test. We also show long-term improvement of planning and memory capacities in…

Optimal lay-up design of variable stiffness laminated composite plates by a layer-wise optimization technique

NASA Astrophysics Data System (ADS)

Houmat, A.

2018-02-01

The optimal lay-up design for the maximum fundamental frequency of variable stiffness laminated composite plates is investigated using a layer-wise optimization technique. The design variables are two fibre orientation angles per ply. Thin plate theory is used in conjunction with a p-element to calculate the fundamental frequencies of symmetrically and antisymmetrically laminated composite plates. Comparisons with existing optimal solutions for constant stiffness symmetrically laminated composite plates show excellent agreement. It is observed that the maximum fundamental frequency can be increased considerably using variable stiffness design as compared to constant stiffness design. In addition, optimal lay-ups for the maximum fundamental frequency of variable stiffness symmetrically and antisymmetrically laminated composite plates with different aspect ratios and various combinations of free, simply supported and clamped edge conditions are presented. These should prove a useful benchmark for optimal lay-ups of variable stiffness laminated composite plates.

The Relationship between Gender and Heterosexual Attitudes toward Homosexuality at a Conservative Christian University

ERIC Educational Resources Information Center

LaFave, Adam D.; Helm, Herbert W., Jr.; Gomez, Omar

2014-01-01

This research looked at the relationships and differences between sex and race as it relates to religious fundamentalism, attitudes, and comfortability toward homosexuality. Patterns in previous research have shown that men and women do differ in their attitudes toward homosexuals. This study proposed that heterosexual men will show a…

Changing Perspectives on the Benefits of Newborn Screening

ERIC Educational Resources Information Center

Bailey, Donald B., Jr.; Beskow, Laura M.; Davis, Arlene M.; Skinner, Debra

2006-01-01

The likelihood of benefit is fundamental to decision making about newborn screening. But benefit is construed in different ways by different stakeholders. This article begins with a review of benefit as considered historically by various expert panels and organizations. We then show how 78 conditions fared when experts recently rated them on…

Cold-mode Accretion: Driving the Fundamental Mass-Metallicity Relation at z ~ 2

NASA Astrophysics Data System (ADS)

Kacprzak, Glenn G.; van de Voort, Freeke; Glazebrook, Karl; Tran, Kim-Vy H.; Yuan, Tiantian; Nanayakkara, Themiya; Allen, Rebecca J.; Alcorn, Leo; Cowley, Michael; Labbé, Ivo; Spitler, Lee; Straatman, Caroline; Tomczak, Adam

2016-07-01

We investigate the star formation rate (SFR) dependence on the stellar mass and gas-phase metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey. We have identified 117 galaxies (1.98 ≤ z ≤ 2.56), with 8.9 ≤ log(M/M ⊙) ≤ 11.0, for which we can measure gas-phase metallicities. For the first time, we show a discernible difference between the mass-metallicity relation, using individual galaxies, when dividing the sample by low (<10 M ⊙ yr-1) and high (>10 M ⊙ yr-1) SFRs. At fixed mass, low star-forming galaxies tend to have higher metallicity than high star-forming galaxies. Using a few basic assumptions, we further show that the gas masses and metallicities required to produce the fundamental mass-metallicity relation and its intrinsic scatter are consistent with cold-mode accretion predictions obtained from the OWLS hydrodynamical simulations. Our results from both simulations and observations are suggestive that cold-mode accretion is responsible for the fundamental mass-metallicity relation at z = 2 and it demonstrates the direct relationship between cosmological accretion and the fundamental properties of galaxies.

Fundamental differences between glassy dynamics in two and three dimensions

PubMed Central

Flenner, Elijah; Szamel, Grzegorz

2015-01-01

The two-dimensional freezing transition is very different from its three-dimensional counterpart. In contrast, the glass transition is usually assumed to have similar characteristics in two and three dimensions. Using computer simulations, here we show that glassy dynamics in supercooled two- and three-dimensional fluids are fundamentally different. Specifically, transient localization of particles on approaching the glass transition is absent in two dimensions, whereas it is very pronounced in three dimensions. Moreover, the temperature dependence of the relaxation time of orientational correlations is decoupled from that of the translational relaxation time in two dimensions but not in three dimensions. Last, the relationships between the characteristic size of dynamically heterogeneous regions and the relaxation time are very different in two and three dimensions. These results strongly suggest that the glass transition in two dimensions is different than in three dimensions. PMID:26067877

Presence of strong harmonics during visual entrainment: a magnetoencephalography study.

PubMed

Heinrichs-Graham, Elizabeth; Wilson, Tony W

2012-09-01

Visual neurons are known to synchronize their firing with stimuli that flicker at a constant rate (e.g. 12Hz). These so-called visual steady-state responses (VSSR) are a well-studied phenomenon, yet the underlying mechanisms are widely disagreed upon. Furthermore, there is limited evidence that visual neurons may simultaneously synchronize at harmonics of the stimulation frequency. We utilized magnetoencephalography (MEG) to examine synchronization at harmonics of the visual stimulation frequency (18Hz). MEG data were analyzed for event-related-synchronization (ERS) at the fundamental frequency, 36, 54, and 72Hz. We found strong ERS in all bands. Only 31% of participants showed maximum entrainment at the fundamental; others showed stronger entrainment at either 36 or 54Hz. The cortical foci of these responses indicated that the harmonics involved cortices that were partially distinct from the fundamental. These findings suggest that spatially-overlapping subpopulations of neurons are simultaneously entrained at different harmonics of the stimulus frequency. Copyright © 2012 Elsevier B.V. All rights reserved.

Improving Understanding of Emotional Speech Acoustic Content

NASA Astrophysics Data System (ADS)

Tinnemore, Anna

Children with cochlear implants show deficits in identifying emotional intent of utterances without facial or body language cues. A known limitation to cochlear implants is the inability to accurately portray the fundamental frequency contour of speech which carries the majority of information needed to identify emotional intent. Without reliable access to the fundamental frequency, other methods of identifying vocal emotion, if identifiable, could be used to guide therapies for training children with cochlear implants to better identify vocal emotion. The current study analyzed recordings of adults speaking neutral sentences with a set array of emotions in a child-directed and adult-directed manner. The goal was to identify acoustic cues that contribute to emotion identification that may be enhanced in child-directed speech, but are also present in adult-directed speech. Results of this study showed that there were significant differences in the variation of the fundamental frequency, the variation of intensity, and the rate of speech among emotions and between intended audiences.

Average State IQ, State Wealth and Racial Composition as Predictors of State Health Statistics: Partial Support for "g" as a Fundamental Cause of Health Disparities

ERIC Educational Resources Information Center

Reeve, Charlie L.; Basalik, Debra

2010-01-01

This study examined the degree to which differences in average IQ across the 50 states was associated with differences in health statistics independent of differences in wealth, health care expenditures and racial composition. Results show that even after controlling for differences in state wealth and health care expenditures, average IQ had…

Vertical coupling and transition energies in multilayer InAs/GaAs quantum-dot structures

NASA Astrophysics Data System (ADS)

Taddei, S.; Colocci, M.; Vinattieri, A.; Bogani, F.; Franchi, S.; Frigeri, P.; Lazzarini, L.; Salviati, G.

2000-10-01

Vertically ordered quantum dots in multilayer InAs/GaAs structures have attracted large interest in recent years for device application as light emitters. Contradictory claims on the dependence of the fundamental transition energy on the interlayer separation and number of dot layers have been reported in the literature. We show that either a blueshift or a redshift of the fundamental transition energy can be observed in different coupling conditions and straightforwardly explained by including strain, indium segregation, and electron-hole Coulomb interaction, in good agreement with experimental results.

Is Memory Search Governed by Universal Principles or Idiosyncratic Strategies?

PubMed Central

Healey, M. Karl; Kahana, Michael J.

2013-01-01

Laboratory paradigms have provided an empirical foundation for much of psychological science. Some have argued, however, that such paradigms are highly susceptible to idiosyncratic strategies and that rather than reflecting fundamental cognitive principles, many findings are artifacts of averaging across participants who employ different strategies. We develop a set of techniques to rigorously test the extent to which average data are distorted by such strategy differences and apply these techniques to free recall data from the Penn Electrophysiology of Encoding and Retrieval Study (PEERS). Recall initiation showed evidence of subgroups: the majority of participants initiate recall from the last item in the list, but one subgroup show elevated initiation probabilities for items 2–4 back from the end of the list and another showed elevated probabilities for the beginning of the list. By contrast, serial position curves and temporal and semantic clustering functions were remarkably consistent, with almost every participant exhibiting a recognizable version of the average function, suggesting that these functions reflect fundamental principles of the memory system. The approach taken here can serve as a model for evaluating the extent to which other laboratory paradigms are influenced by individual differences in strategy use. PMID:23957279

Fundamental gaps with approximate density functionals: The derivative discontinuity revealed from ensemble considerations

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

Kraisler, Eli; Kronik, Leeor

2014-05-14

The fundamental gap is a central quantity in the electronic structure of matter. Unfortunately, the fundamental gap is not generally equal to the Kohn-Sham gap of density functional theory (DFT), even in principle. The two gaps differ precisely by the derivative discontinuity, namely, an abrupt change in slope of the exchange-correlation energy as a function of electron number, expected across an integer-electron point. Popular approximate functionals are thought to be devoid of a derivative discontinuity, strongly compromising their performance for prediction of spectroscopic properties. Here we show that, in fact, all exchange-correlation functionals possess a derivative discontinuity, which arises naturallymore » from the application of ensemble considerations within DFT, without any empiricism. This derivative discontinuity can be expressed in closed form using only quantities obtained in the course of a standard DFT calculation of the neutral system. For small, finite systems, addition of this derivative discontinuity indeed results in a greatly improved prediction for the fundamental gap, even when based on the most simple approximate exchange-correlation density functional – the local density approximation (LDA). For solids, the same scheme is exact in principle, but when applied to LDA it results in a vanishing derivative discontinuity correction. This failure is shown to be directly related to the failure of LDA in predicting fundamental gaps from total energy differences in extended systems.« less

Visual field differences in visual word recognition can emerge purely from perceptual learning: evidence from modeling Chinese character pronunciation.

PubMed

Hsiao, Janet Hui-Wen

2011-11-01

In Chinese orthography, a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters); a minority opposite arrangement also exists (PS characters). As the number of phonetic radical types is much greater than semantic radical types, in SP characters the information is skewed to the right, whereas in PS characters it is skewed to the left. Through training a computational model for SP and PS character recognition that takes into account of the locations in which the characters appear in the visual field during learning, but does not assume any fundamental hemispheric processing difference, we show that visual field differences can emerge as a consequence of the fundamental structural differences in information between SP and PS characters, as opposed to the fundamental processing differences between the two hemispheres. This modeling result is also consistent with behavioral naming performance. This work provides strong evidence that perceptual learning, i.e., the information structure of word stimuli to which the readers have long been exposed, is one of the factors that accounts for hemispheric asymmetry effects in visual word recognition. Copyright © 2011 Elsevier Inc. All rights reserved.

Design and analysis for a bend-resistant and large-mode-area photonic crystal fiber with hybrid cladding.

PubMed

Qin, Yan; Yang, Huajun; Jiang, Ping; Gui, Fengji; Caiyang, Weinan; Cao, Biao

2018-05-10

In this paper, an asymmetric large-mode-area photonic crystal fiber (LMA-PCF) with low bending loss at a smaller bending radius is designed. The finite-element method with a perfectly matched layer boundary is used to analyze the performance of the PCF. To achieve LMA-PCF with low bending loss, the air holes with double lattice constants and different sizes at the core are designed. Numerical results show that this structure can achieve low bending loss and LMA with a smaller bending radius at the wavelength of 1.55 μm. The effective mode area of the fundamental mode is larger than 1000  μm 2 when the bending radius is ≥10  cm. The bending loss of the fundamental mode is just 0.0113 dB/m, and the difference between the fundamental and high-order modes of the bending loss is larger than 10 3 when the bending radius is 10 cm. Simulation results show this novel PCF can achieve LMA and have effective single-mode operation when the bending orientation angle ranges in ±110°. This novel photonic crystal has potential application in high-power fiber lasers.

Stimulus presentation order and the perception of lexical tones in Cantonese

NASA Astrophysics Data System (ADS)

Francis, Alexander L.; Ciocca, Valter

2003-09-01

Listeners' auditory discrimination of vowel sounds depends in part on the order in which stimuli are presented. Such presentation order effects have been argued to be language independent, and to result from psychophysical (not speech- or language-specific) factors such as the decay of memory traces over time or increased weighting of later-occurring stimuli. In the present study, native Cantonese speakers' discrimination of a linguistic tone continuum is shown to exhibit order of presentation effects similar to those shown for vowels in previous studies. When presented with two successive syllables differing in fundamental frequency by approximately 4 Hz, listeners were significantly more sensitive to this difference when the first syllable was higher in frequency than the second. However, American English-speaking listeners with no experience listening to Cantonese showed no such contrast effect when tested in the same manner using the same stimuli. Neither English nor Cantonese listeners showed any order of presentation effects in the discrimination of a nonspeech continuum in which tokens had the same fundamental frequencies as the Cantonese speech tokens but had a qualitatively non-speech-like timbre. These results suggest that tone presentation order effects, unlike vowel effects, may be language specific, possibly resulting from the need to compensate for utterance-related pitch declination when evaluating fundamental frequency for tone identification.

Face and Construct Validity of a Novel Virtual Reality-Based Bimanual Laparoscopic Force-Skills Trainer With Haptics Feedback.

PubMed

Prasad, Raghu; Muniyandi, Manivannan; Manoharan, Govindan; Chandramohan, Servarayan M

2018-05-01

The purpose of this study was to examine the face and construct validity of a custom-developed bimanual laparoscopic force-skills trainer with haptics feedback. The study also examined the effect of handedness on fundamental and complex tasks. Residents (n = 25) and surgeons (n = 25) performed virtual reality-based bimanual fundamental and complex tasks. Tool-tissue reaction forces were summed, recorded, and analysed. Seven different force-based measures and a 1-time measure were used as metrics. Subsequently, participants filled out face validity and demographic questionnaires. Residents and surgeons were positive on the design, workspace, and usefulness of the simulator. Construct validity results showed significant differences between residents and experts during the execution of fundamental and complex tasks. In both tasks, residents applied large forces with higher coefficient of variation and force jerks (P < .001). Experts, with their dominant hand, applied lower forces in complex tasks and higher forces in fundamental tasks (P < .001). The coefficients of force variation (CoV) of residents and experts were higher in complex tasks (P < .001). Strong correlations were observed between CoV and task time for fundamental (r = 0.70) and complex tasks (r = 0.85). Range of smoothness of force was higher for the non-dominant hand in both fundamental and complex tasks. The simulator was able to differentiate the force-skills of residents and surgeons, and objectively evaluate the effects of handedness on laparoscopic force-skills. Competency-based laparoscopic skills assessment curriculum should be updated to meet the requirements of bimanual force-based training.

The stability of H/V spectral ratios from noise measurements in Armutlu Peninsula (Turkey)

NASA Astrophysics Data System (ADS)

Livaoǧlu, Hamdullah; Irmak, T. Serkan; Caka, Deniz; Yavuz, Evrim; Lühr, B. G.; Woith, H.; Tunç, B.; Baris, S.

2016-04-01

The horizontal to vertical spectral ratio (H/V) method has been successfully using in order to estimate the fundamental resonance frequency of the sedimentary cover, its thickness and amplification factor since at least 3 decades. There are numerous studies have been carried out on the stability of the H/V spectral ratios. Almost all studies showed that fundamental frequency is stable even measurements are repeated at different times. From this point of view, the results will show us an approach whether the stations are suitable for accurate estimate of earthquake studies and engineering purposes or not. Also we want to see if any effects of the amplification factor changing on the seismograms for Armutlu Seismic Network (ARNET) even though seismic stations are established far away from cultural noise and located on hard rock sites. It has been selected one hour recorded data of all stations during the most stationary times. The amplification and resonant frequency variations of H/V ratio were calculated to investigate temporal stability in time. There is a total harmony in fundamental frequencies values and H/V spectral ratio values in time-lagged periods. Some stations shows secondary minor peaks in high frequency band due to a shallow formation effect or cultural noises around. In the east side of the area ILYS station shows amplitude peak in lower fundamental frequency band from expected. This could compose a high amplification in lower frequencies and so that yield less reliable results in local earthquakes studies. By the experimental results from ambient noise analysis, it could be worked up for relocation of one station.

Perception of the fundamental frequencies of children's voices by trained and untrained listeners.

PubMed

Wilson, F B; Wellen, C J; Kimbarow, M L

1983-10-01

This study was designed to determine if trained voice clinicians were better than untrained listeners in judging differences in the fundamental frequencies of children's voices. We also attempted to determine the degree of difference in fundamental frequency necessary for accurate judgments. Finally, ability to perceive pitch differences in speaking voices was correlated with ability to judge puretone stimuli. Results indicated that trained clinicians were no better at judging average fundamental frequency than were untrained listeners. Both groups performed at chance level until differences in vocal fundamental frequency exceeded 20 Hz. Finally, there was no correlation between subjects' success on standardized puretone pitch tests and ability to judge average pitch in the speaking voice.

COLD-MODE ACCRETION: DRIVING THE FUNDAMENTAL MASS–METALLICITY RELATION AT z ∼ 2

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

Kacprzak, Glenn G.; Glazebrook, Karl; Nanayakkara, Themiya

2016-07-20

We investigate the star formation rate (SFR) dependence on the stellar mass and gas-phase metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey. We have identified 117 galaxies (1.98 ≤ z ≤ 2.56), with 8.9 ≤ log( M / M {sub ⊙}) ≤ 11.0, for which we can measure gas-phase metallicities. For the first time, we show a discernible difference between the mass–metallicity relation, using individual galaxies, when dividing the sample by low (<10 M {sub ⊙} yr{sup −1}) and high (>10 M {sub ⊙} yr{sup −1}) SFRs. At fixed mass, low star-forming galaxies tendmore » to have higher metallicity than high star-forming galaxies. Using a few basic assumptions, we further show that the gas masses and metallicities required to produce the fundamental mass–metallicity relation and its intrinsic scatter are consistent with cold-mode accretion predictions obtained from the OWLS hydrodynamical simulations. Our results from both simulations and observations are suggestive that cold-mode accretion is responsible for the fundamental mass–metallicity relation at z = 2 and it demonstrates the direct relationship between cosmological accretion and the fundamental properties of galaxies.« less

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for fundamentally different factors. (a) Definition. The term Requester means an Industrial User or a... a certain Industrial User within an industrial category or subcategory. This will only be done if data specific to that Industrial User indicates it presents factors fundamentally different from those...

Mixing of two co-directional Rayleigh surface waves in a nonlinear elastic material.

PubMed

Morlock, Merlin B; Kim, Jin-Yeon; Jacobs, Laurence J; Qu, Jianmin

2015-01-01

The mixing of two co-directional, initially monochromatic Rayleigh surface waves in an isotropic, homogeneous, and nonlinear elastic solid is investigated using analytical, finite element method, and experimental approaches. The analytical investigations show that while the horizontal velocity component can form a shock wave, the vertical velocity component can form a pulse independent of the specific ratios of the fundamental frequencies and amplitudes that are mixed. This analytical model is then used to simulate the development of the fundamentals, second harmonics, and the sum and difference frequency components over the propagation distance. The analytical model is further extended to include diffraction effects in the parabolic approximation. Finally, the frequency and amplitude ratios of the fundamentals are identified which provide maximum amplitudes of the second harmonics as well as of the sum and difference frequency components, to help guide effective material characterization; this approach should make it possible to measure the acoustic nonlinearity of a solid not only with the second harmonics, but also with the sum and difference frequency components. Results of the analytical investigations are then confirmed using the finite element method and the experimental feasibility of the proposed technique is validated for an aluminum specimen.

Symmetry and Interculturality

ERIC Educational Resources Information Center

Marchis, Iuliana

2009-01-01

Symmetry is one of the fundamental concepts in Geometry. It is a Mathematical concept, which can be very well connected with Art and Ethnography. The aim of the article is to show how to link the geometrical concept symmetry with interculturality. For this mosaics from different countries are used.

Resveratrol Photoisomerization: An Integrative Guided-Inquiry Experiment

ERIC Educational Resources Information Center

Bernanrd, Elyse; Britz-McKibbin, Philip; Gernigon, Nicholas

2007-01-01

The recently introduced integrative guided-inquiry experiment explains various fundamental chemical concepts related to different biologically relevant molecules like resveratrol. The results of the photoisomerization of the molecule show that it is a very effective chemopreventative agent that can extend the lifespan in several organisms.

Subharmonic and fundamental high amplitude excitation of an axisymmetric jet

NASA Technical Reports Server (NTRS)

Raman, Ganesh; Rice, Edward J.

1989-01-01

A circular jet was excited simultaneously by two different harmonically related tones. Data for three pairs of Strouhal numbers (St(D) = f*D/U (sub j) = 0.2 and 0.4, 0.3 and 0.6, 0.4 and 0.8). For each case the initial phase difference between the two waves was varied in steps of 45 deg, for one full cycle and the level of the fundamental and subharmonic forcing were varied independently over the range of 0.1 to 7 percent of the jet exit velocity. Our initial findings concurred with published findings, such as a critical level of the fundamental is required for subharmonic augmentation, the initial phase difference is critical in determining whether the subharmonic is augmented or suppressed. The detailed documentation of several aspects of this phenomenon all measured in one and the same experimental facility in a controlled manner, bring out several important points that eluded previous researchers: (1) At high amplitudes of the fundamental and subharmonic forcing levels the subharmonic augmentation is independent of the initial phase difference. (2) Contrary to the earlier belief that stable pairing could be produced only with an initial laminar boundary layer, the present work shows that by the two-frequency excitation method this phenomenon can be induced over a range of conditions for a jet with an initially turbulent boundary layer. (3) It is seen that two-frequency excitation is indeed more effective than single frequency excitation in jet mixing enhancement. Higher spreading rates seem to go along with higher subharmonic levels.

Differences in Motivations between Fundamental Christians and Atheists on the Reiss Profile of Fundamental Goals and Motivational Sensitivities.

ERIC Educational Resources Information Center

Beasley, Amy; Rowell, Kevin

A study examined differences in motivations between fundamental Christians and atheists on the Reiss Profile of Fundamental Goals and Motivational Sensitivities. Only five of the 15 areas measured by the Reiss Profile were used in the study. The hypothesis was that (within these areas: (1) independence, (2) power, (3) vengeance, (4) status, and…

People both high and low on religious fundamentalism are prejudiced toward dissimilar groups.

PubMed

Brandt, Mark J; Van Tongeren, Daryl R

2017-01-01

[Correction Notice: An Erratum for this article was reported in Vol 112(1) of Journal of Personality and Social Psychology (see record 2016-61714-004). In the article, the sample size of N = 5,806 in the abstract is incorrect. The correct sample size is N = 6,047.] Research linking religion to prejudice suggests that highly religious individuals, and religious fundamentalists specifically, may be especially susceptible to expressing prejudice toward dissimilar others, whereas people who are less religious and fundamentalist do not show the same effect. The selective prejudice hypothesis predicts that this pattern of results occurs because the cognitive and motivational styles or particular values associated with fundamentalism exacerbate prejudice. In 3 studies, using 4 data sets (N = 6,047), we test this selective prejudice hypothesis against the religious values conflict hypothesis, which predicts that both people with high and low levels of fundamentalism will be prejudiced toward those with dissimilar beliefs to protect the validity and vitality of people's belief systems. Consistent with the religious values conflict hypothesis, we found that people both high and low in fundamentalism were prejudiced toward dissimilar others (Study 1) and these differences were primarily due to differences in the content of religious belief rather than the style of belief (Study 2). In Study 3, we expanded these findings to additional measures of prejudice, found that multiple measures of threat were potential mediators, and explored the possibility of an integrative perspective. In total, these results suggest that people with both relatively high and low levels of fundamentalism are susceptible to prejudice and in some cases the size of this religious intergroup bias may be higher among people with high levels of fundamentalism. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Rogue-wave solutions of the Zakharov equation

NASA Astrophysics Data System (ADS)

Rao, Jiguang; Wang, Lihong; Liu, Wei; He, Jingsong

2017-12-01

Using the bilinear transformation method, we derive general rogue-wave solutions of the Zakharov equation. We present these Nth-order rogue-wave solutions explicitly in terms of Nth-order determinants whose matrix elements have simple expressions. We show that the fundamental rogue wave is a line rogue wave with a line profile on the plane ( x, y) arising from a constant background at t ≪ 0 and then gradually tending to the constant background for t ≫ 0. Higher-order rogue waves arising from a constant background and later disappearing into it describe the interaction of several fundamental line rogue waves. We also consider different structures of higher-order rogue waves. We present differences between rogue waves of the Zakharov equation and of the first type of the Davey-Stewartson equation analytically and graphically.

The stability of H/V spectral ratios from noise measurements in Armutlu Peninsula (Turkey)

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

Livaoğlu, Hamdullah, E-mail: hamdullah.livaoglu@kocaeli.edu.tr; Irmak, T. Serkan; Caka, Deniz

The horizontal to vertical spectral ratio (H/V) method has been successfully using in order to estimate the fundamental resonance frequency of the sedimentary cover, its thickness and amplification factor since at least 3 decades. There are numerous studies have been carried out on the stability of the H/V spectral ratios. Almost all studies showed that fundamental frequency is stable even measurements are repeated at different times. From this point of view, the results will show us an approach whether the stations are suitable for accurate estimate of earthquake studies and engineering purposes or not. Also we want to see ifmore » any effects of the amplification factor changing on the seismograms for Armutlu Seismic Network (ARNET) even though seismic stations are established far away from cultural noise and located on hard rock sites. It has been selected one hour recorded data of all stations during the most stationary times. The amplification and resonant frequency variations of H/V ratio were calculated to investigate temporal stability in time. There is a total harmony in fundamental frequencies values and H/V spectral ratio values in time-lagged periods. Some stations shows secondary minor peaks in high frequency band due to a shallow formation effect or cultural noises around. In the east side of the area ILYS station shows amplitude peak in lower fundamental frequency band from expected. This could compose a high amplification in lower frequencies and so that yield less reliable results in local earthquakes studies. By the experimental results from ambient noise analysis, it could be worked up for relocation of one station.« less

Continuous monitoring of high-rise buildings using seismic interferometry

NASA Astrophysics Data System (ADS)

Mordret, A.; Sun, H.; Prieto, G. A.; Toksoz, M. N.; Buyukozturk, O.

2016-12-01

The linear seismic response of a building is commonly extracted from ambient vibration measurements. Seismic deconvolution interferometry performed on ambient vibration measurements can also be used to estimate the dynamic characteristics of a building, such as the velocity of shear-waves travelling inside the building as well as a damping parameter depending on the intrinsic attenuation of the building and the soil-structure coupling. The continuous nature of the ambient vibrations allows us to measure these parameters repeatedly and to observe their temporal variations. We used 2 weeks of ambient vibration recorded by 36 accelerometers installed in the Green Building on the Massachusetts Institute of Technology campus (Cambridge, MA) to continuously monitor the shear-wave speed and the attenuation factor of the building. Due to the low strain of the ambient vibrations, the observed changes are totally reversible. The relative velocity changes between a reference deconvolution function and the current deconvolution functions are measured with two different methods: 1) the Moving Window Cross-Spectral technique and 2) the stretching technique. Both methods show similar results. We show that measuring the stretching coefficient for the deconvolution functions filtered around the fundamental mode frequency is equivalent to measuring the wandering of the fundamental frequency in the raw ambient vibration data. By comparing these results with local weather parameters, we show that the relative air humidity is the factor dominating the relative seismic velocity variations in the Green Building, as well as the wandering of the fundamental mode. The one-day periodic variations are affected by both the temperature and the humidity. The attenuation factor, measured as the exponential decay of the fundamental mode waveforms, shows a more complex behaviour with respect to the weather measurements.

Mass sensing based on deterministic and stochastic responses of elastically coupled nanocantilevers.

PubMed

Gil-Santos, Eduardo; Ramos, Daniel; Jana, Anirban; Calleja, Montserrat; Raman, Arvind; Tamayo, Javier

2009-12-01

Coupled nanomechanical systems and their entangled eigenstates offer unique opportunities for the detection of ultrasmall masses. In this paper we show theoretically and experimentally that the stochastic and deterministic responses of a pair of coupled nanocantilevers provide different and complementary information about the added mass of an analyte and its location. This method allows the sensitive detection of minute quantities of mass even in the presence of large initial differences in the active masses of the two cantilevers. Finally, we show the fundamental limits in mass detection of this sensing paradigm.

"People both high and low on religious fundamentalism are prejudiced toward dissimilar groups": Correction to Brandt and Van Tongeren (2015).

PubMed

2017-01-01

Reports an error in "People Both High and Low on Religious Fundamentalism Are Prejudiced Toward Dissimilar Groups" by Mark J. Brandt and Daryl R. Van Tongeren ( Journal of Personality and Social Psychology , Advanced Online Publication, Nov 2, 2015, np). In the article, the sample size of N = 5,806 in the abstract is incorrect. The correct sample size is N = 6,047. (The following abstract of the original article appeared in record 2015-49839-001.) Research linking religion to prejudice suggests that highly religious individuals, and religious fundamentalists specifically, may be especially susceptible to expressing prejudice toward dissimilar others, whereas people who are less religious and fundamentalist do not show the same effect. The selective prejudice hypothesis predicts that this pattern of results occurs because the cognitive and motivational styles or particular values associated with fundamentalism exacerbate prejudice. In 3 studies, using 4 data sets (N = 5,806), we test this selective prejudice hypothesis against the religious values conflict hypothesis, which predicts that both people with high and low levels of fundamentalism will be prejudiced toward those with dissimilar beliefs to protect the validity and vitality of people's belief systems. Consistent with the religious values conflict hypothesis, we found that people both high and low in fundamentalism were prejudiced toward dissimilar others (Study 1) and these differences were primarily due to differences in the content of religious belief rather than the style of belief (Study 2). In Study 3, we expanded these findings to additional measures of prejudice, found that multiple measures of threat were potential mediators, and explored the possibility of an integrative perspective. In total, these results suggest that people with both relatively high and low levels of fundamentalism are susceptible to prejudice and in some cases the size of this religious intergroup bias may be higher among people with high levels of fundamentalism. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Using Questioning to Stimulate Mathematical Thinking

ERIC Educational Resources Information Center

Way, Jenni

2008-01-01

Good questioning techniques have long been regarded as a fundamental tool of effective teachers and research has found that "differences in students' thinking and reasoning could be attributed to the type of questions that teachers asked" (Wood, 2002). Past research shows that 93% of teacher questions were "lower order" knowledge-based questions…

Early Detection of Markers for Synaesthesia in Childhood Populations

ERIC Educational Resources Information Center

Simner, Julia; Harrold, Jenny; Creed, Harriet; Monro, Louise; Foulkes, Louise

2009-01-01

We show that the neurological condition of synaesthesia--which causes fundamental differences in perception and cognition throughout a lifetime--is significantly represented within the childhood population, and that it manifests behavioural markers as young as age 6 years. Synaesthesia gives rise to a merging of cognitive and/or sensory functions…

Auditory perception bias in speech imitation

PubMed Central

Postma-Nilsenová, Marie; Postma, Eric

2013-01-01

In an experimental study, we explored the role of auditory perception bias in vocal pitch imitation. Psychoacoustic tasks involving a missing fundamental indicate that some listeners are attuned to the relationship between all the higher harmonics present in the signal, which supports their perception of the fundamental frequency (the primary acoustic correlate of pitch). Other listeners focus on the lowest harmonic constituents of the complex sound signal which may hamper the perception of the fundamental. These two listener types are referred to as fundamental and spectral listeners, respectively. We hypothesized that the individual differences in speakers' capacity to imitate F0 found in earlier studies, may at least partly be due to the capacity to extract information about F0 from the speech signal. Participants' auditory perception bias was determined with a standard missing fundamental perceptual test. Subsequently, speech data were collected in a shadowing task with two conditions, one with a full speech signal and one with high-pass filtered speech above 300 Hz. The results showed that perception bias toward fundamental frequency was related to the degree of F0 imitation. The effect was stronger in the condition with high-pass filtered speech. The experimental outcomes suggest advantages for fundamental listeners in communicative situations where F0 imitation is used as a behavioral cue. Future research needs to determine to what extent auditory perception bias may be related to other individual properties known to improve imitation, such as phonetic talent. PMID:24204361

Networks’ Characteristics Matter for Systems Biology

PubMed Central

Rider, Andrew K.; Milenković, Tijana; Siwo, Geoffrey H.; Pinapati, Richard S.; Emrich, Scott J.; Ferdig, Michael T.; Chawla, Nitesh V.

2015-01-01

A fundamental goal of systems biology is to create models that describe relationships between biological components. Networks are an increasingly popular approach to this problem. However, a scientist interested in modeling biological (e.g., gene expression) data as a network is quickly confounded by the fundamental problem: how to construct the network? It is fairly easy to construct a network, but is it the network for the problem being considered? This is an important problem with three fundamental issues: How to weight edges in the network in order to capture actual biological interactions? What is the effect of the type of biological experiment used to collect the data from which the network is constructed? How to prune the weighted edges (or what cut-off to apply)? Differences in the construction of networks could lead to different biological interpretations. Indeed, we find that there are statistically significant dissimilarities in the functional content and topology between gene co-expression networks constructed using different edge weighting methods, data types, and edge cut-offs. We show that different types of known interactions, such as those found through Affinity Capture-Luminescence or Synthetic Lethality experiments, appear in significantly varying amounts in networks constructed in different ways. Hence, we demonstrate that different biological questions may be answered by the different networks. Consequently, we posit that the approach taken to build a network can be matched to biological questions to get targeted answers. More study is required to understand the implications of different network inference approaches and to draw reliable conclusions from networks used in the field of systems biology. PMID:26500772

Comparison of fundamental, second harmonic, and superharmonic imaging: a simulation study.

PubMed

van Neer, Paul L M J; Danilouchkine, Mikhail G; Verweij, Martin D; Demi, Libertario; Voormolen, Marco M; van der Steen, Anton F W; de Jong, Nico

2011-11-01

In medical ultrasound, fundamental imaging (FI) uses the reflected echoes from the same spectral band as that of the emitted pulse. The transmission frequency determines the trade-off between penetration depth and spatial resolution. Tissue harmonic imaging (THI) employs the second harmonic of the emitted frequency band to construct images. Recently, superharmonic imaging (SHI) has been introduced, which uses the third to the fifth (super) harmonics. The harmonic level is determined by two competing phenomena: nonlinear propagation and frequency dependent attenuation. Thus, the transmission frequency yielding the optimal trade-off between the spatial resolution and the penetration depth differs for THI and SHI. This paper quantitatively compares the concepts of fundamental, second harmonic, and superharmonic echocardiography at their optimal transmission frequencies. Forward propagation is modeled using a 3D-KZK implementation and the iterative nonlinear contrast source (INCS) method. Backpropagation is assumed to be linear. Results show that the fundamental lateral beamwidth is the narrowest at focus, while the superharmonic one is narrower outside the focus. The lateral superharmonic roll-off exceeds the fundamental and second harmonic roll-off. Also, the axial resolution of SHI exceeds that of FI and THI. The far-field pulse-echo superharmonic pressure is lower than that of the fundamental and second harmonic. SHI appears suited for echocardiography and is expected to improve its image quality at the cost of a slight reduction in depth-of-field.

Quantification of the level of crowdedness for pedestrian movements

NASA Astrophysics Data System (ADS)

Duives, Dorine C.; Daamen, Winnie; Hoogendoorn, Serge P.

2015-06-01

Within the realm of pedestrian research numerous measures have been proposed to estimate the level of crowdedness experienced by pedestrians. However, within the field of pedestrian traffic flow modelling there does not seem to be consensus on the question which of these measures performs best. This paper shows that the shape and scatter within the resulting fundamental diagrams differs a lot depending on the measure of crowdedness used. The main aim of the paper is to establish the advantages and disadvantages of the currently existing measures to quantify crowdedness in order to evaluate which measures provide both accurate and consistent results. The assessment is not only based on the theoretical differences, but also on the qualitative and quantitative differences between the resulting fundamental diagrams computed using the crowdedness measures on one and the same data set. The qualitative and quantitative functioning of the classical Grid-based measure is compared to with the X-T measure, an Exponentially Weighted Distance measure, and a Voronoi-Diagram measure. The consistency of relating these measures for crowdedness to the two macroscopic flow variables velocity and flow, the computational efficiency and the amount of scatter present within the fundamental diagrams produced by the implementation of the different measures are reviewed. It is found that the Voronoi-Diagram and X-T measure are the most efficient and consistent measures for crowdedness.

Exchange Rates and Fundamentals.

ERIC Educational Resources Information Center

Engel, Charles; West, Kenneth D.

2005-01-01

We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

Experts and Novices: Differences in Their Use of Mental Representation and Metacognition in Engineering Design

ERIC Educational Resources Information Center

Dixon, Raymond Anthony

2010-01-01

Research shows that mental representation such as analogical reasoning is a fundamental cognitive tool for design problem solving (Daugherty & Mentzer, 2008; Hey, Lensey, Agogino, & Wood, 2008; Lewis, 2008). Not much is known, however, about the way students and professional engineers actively generate and change their mental representation when…

Collapse events of two-color optical beams

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

Sukhinin, Alexey; Aceves, Alejandro B.; Diels, Jean-Claude

2017-03-08

Here in this work, we study optical self-focusing that leads to collapse events for the time-independent model of copropagating beams with different wavelengths. We show that collapse events depend on the combined critical power of two beams for fundamental, vortex, and mixed configurations as well as on the ratio of their individual powers.

Vowel selection and its effects on perturbation and nonlinear dynamic measures.

PubMed

Maccallum, Julia K; Zhang, Yu; Jiang, Jack J

2011-01-01

Acoustic analysis of voice is typically conducted on recordings of sustained vowel phonation. This study applied perturbation and nonlinear dynamic analyses to the vowels /a/, /i/, and /u/ in order to determine vowel selection effects on analysis. Forty subjects (20 males and 20 females) with normal voices participated in recording. Traditional parameters of fundamental frequency, signal-to-noise ratio, percent jitter, and percent shimmer were calculated for the signals using CSpeech. Nonlinear dynamic parameters of correlation dimension and second-order entropy were also calculated. Perturbation analysis results were largely incongruous in this study and in previous research. Fundamental frequency results corroborated previous work, indicating higher fundamental frequency for /i/ and /u/ and lower fundamental frequency for /a/. Signal-to-noise ratio results showed that /i/ and /u/ have greater harmonic levels than /a/. Results of nonlinear dynamic analysis suggested that more complex activity may be evident in /a/ than in /i/ or /u/. Percent jitter and percent shimmer may not be useful for description of acoustic differences between vowels. Fundamental frequency, signal-to-noise ratio, and nonlinear dynamic parameters may be applied to characterize /a/ as having lower frequency, higher noise, and greater nonlinear components than /i/ and /u/. Copyright © 2010 S. Karger AG, Basel.

Are sex differences in fundamental motor skills uniform throughout the entire preschool period?

PubMed

Kokštejn, Jakub; Musálek, Martin; Tufano, James J

2017-01-01

The aim of this study was to assess differences in fundamental motor skills (FMS) proficiency between boys and girls of each age group, independently, across the entire preschool period. Using the Movement Assessment Battery for Children-second edition, FMS proficiency was tested in 325 preschoolers (4.9 ± 1.1 y, range 3-6) using a cross-sectional design. Compared to boys of the same age, 3- and 4-year-old girls had greater total (p < .01), fine motor skill (p < .01), and balance scores (p < .05). There were no sex differences for total test or balance scores in 5- and 6-year-olds, but 6-year-old boys outperformed girls in aiming and catching (p < .001). These data not only agree with previous research in that sex differences in FMS proficiency exist in preschool children, but the data also show that differences may not be uniform throughout the whole preschool period when analyzing by age. To avoid under- or overestimating FMS proficiency and subsequently prescribing inaccurate motor intervention programs, FMS proficiency normative values should be age- and sex-specific throughout the entire preschool period.

A comparison of harmonic production in trained and untrained singers

NASA Astrophysics Data System (ADS)

Hildebrand, Jonathan H.; Caso, Hilary J.

2004-05-01

This study was designed to investigate the differences in the tone qualities of trained and untrained singers of both genders by measuring the ratio of energy found in the fundamental frequency to that found in the harmonics of the two groups. Forty trained and untrained male and female subjects (ten in each group) sang the vowels [a e i o u] in the words ``me cake father obey too.'' Each subject sang through the list of words in its entirety one time. They were also asked to produce each word at a constant pitch of their choosing. The intensity (dB) was then measured at the vowel midpoint in the intact vowel, and then again with the fundamental filtered out. These two measurements allowed for a comparison to be made by subtracting the results. This process produced results showing that the fundamental frequency was responsible for the majority of the trained singers', vocal productions, where harmonics were responsible for the majority of the untrained singers', vocal productions. The data also showed that these results were more prominent for the production of the high vowels in both genders, and for women overall.

Reduced adaptability, but no fundamental disruption, of norm-based face coding following early visual deprivation from congenital cataracts.

PubMed

Rhodes, Gillian; Nishimura, Mayu; de Heering, Adelaide; Jeffery, Linda; Maurer, Daphne

2017-05-01

Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in individuals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital cataracts in infancy. We measured adaptive coding using face identity aftereffects, where smaller aftereffects indicate less adaptive updating of face-coding mechanisms by experience. We also examined whether the aftereffects increase with adaptor identity strength, consistent with norm-based coding of identity, as in typical populations, or whether they show a different pattern indicating some more fundamental disruption of face-coding mechanisms. Cataract-reversal patients showed significantly smaller face identity aftereffects than did controls (Experiments 1 and 2). However, their aftereffects increased significantly with adaptor strength, consistent with norm-based coding (Experiment 2). Thus we found reduced adaptability but no fundamental disruption of norm-based face-coding mechanisms in cataract-reversal patients. Our results suggest that early visual experience is important for the normal development of adaptive face-coding mechanisms. © 2016 John Wiley & Sons Ltd.

Observations concerning the generation and propagation of Type III solar bursts

NASA Technical Reports Server (NTRS)

Kellogg, P. J.

1986-01-01

A number of Type III bursts were observed during the Helios missions in which the burst exciter passed over the spacecraft, as evidenced by strong electric field fluctuations near the plasma frequency. Six of these were suitable for detailed study. Of the six events, one was ambiguous, one showed what is interpreted as a switchover from harmonic to fundamental, and the rest all generated fundamental at onset. This would be expected if both fundamental and harmonic are generated, as, at a fixed frequency, the fundamental will be generated earlier. For the event which seems to show both fundamental and harmonic emission, the frequency ratio is not exactly 2. This is explained in terms of a time delay of the fundamental, due to scattering and diffusion in the source region. A time delay of the order of 600 seconds at 1 AU and 20 kHz, and inversely proportional to frequency, is required to explain the observations. Crude estimates show that delay times at least this long may be attributed to trapping and scattering.

Cause-effect relationship between vocal fold physiology and voice production in a three-dimensional phonation model

PubMed Central

Zhang, Zhaoyan

2016-01-01

The goal of this study is to better understand the cause-effect relation between vocal fold physiology and the resulting vibration pattern and voice acoustics. Using a three-dimensional continuum model of phonation, the effects of changes in vocal fold stiffness, medial surface thickness in the vertical direction, resting glottal opening, and subglottal pressure on vocal fold vibration and different acoustic measures are investigated. The results show that the medial surface thickness has dominant effects on the vertical phase difference between the upper and lower margins of the medial surface, closed quotient, H1-H2, and higher-order harmonics excitation. The main effects of vocal fold approximation or decreasing resting glottal opening are to lower the phonation threshold pressure, reduce noise production, and increase the fundamental frequency. Increasing subglottal pressure is primarily responsible for vocal intensity increase but also leads to significant increase in noise production and an increased fundamental frequency. Increasing AP stiffness significantly increases the fundamental frequency and slightly reduces noise production. The interaction among vocal fold thickness, stiffness, approximation, and subglottal pressure in the control of F0, vocal intensity, and voice quality is discussed. PMID:27106298

A review of recent theoretical studies in nonlinear crystals: towards the design of new materials

NASA Astrophysics Data System (ADS)

Luppi, Eleonora; Véniard, Valérie

2016-12-01

Nonlinear optics is an important and exciting field of fundamental and applied research, with applications in many different disciplines such as physics chemistry, material science and biology. In the recent years, nonlinear optical phenomena started to be also widely used in technological applications for optoelectronics and photovoltaics. This coincided with an important experimental and theoretical search for new materials with an efficient and exploitable nonlinear optical response. Here, starting from the discovery of nonlinear optics, we review the most important theoretical formalisms developed to understand, interpret and predict the nonlinear optical phenomena. We show the different level of approximation of the many-electrons interactions that these formalisms can describe which are fundamental in the interpretation of the experiments. The impact of the theory is then analyzed on different classes of new materials particularly studied in these years: silicon bulk to nano, compound semiconductors, graphene, transition metal dichalcogenide, hexagonal boron nitride and borate crystals.

Reconsidering earthquake scaling

USGS Publications Warehouse

Gomberg, Joan S.; Wech, Aaron G.; Creager, Kenneth; Obara, K.; Agnew, Duncan

2016-01-01

The relationship (scaling) between scalar moment, M0, and duration, T, potentially provides key constraints on the physics governing fault slip. The prevailing interpretation of M0-T observations proposes different scaling for fast (earthquakes) and slow (mostly aseismic) slip populations and thus fundamentally different driving mechanisms. We show that a single model of slip events within bounded slip zones may explain nearly all fast and slow slip M0-T observations, and both slip populations have a change in scaling, where the slip area growth changes from 2-D when too small to sense the boundaries to 1-D when large enough to be bounded. We present new fast and slow slip M0-T observations that sample the change in scaling in each population, which are consistent with our interpretation. We suggest that a continuous but bimodal distribution of slip modes exists and M0-T observations alone may not imply a fundamental difference between fast and slow slip.

Washing the patient: dignity and aesthetic values in nursing care.

PubMed

Pols, Jeannette

2013-07-01

Dignity is a fundamental concept, but its meaning is not clear. This paper attempts to clarify the term by analysing and reconnecting two meanings of dignity: humanitas and dignitas. Humanitas refers to citizen values that protect individuals as equal to one another. Dignitas refers to aesthetic values embedded in genres of sociality that relate to differences between people. The paper explores these values by way of an empirical ethical analysis of practices of washing psychiatric patients in nursing care. Nurses legitimate the washing of reluctant patients with reference to dignity. The analysis shows the intertwinement of humanitas and dignitas that gives dignity its fundamental meaning. © 2013 John Wiley & Sons Ltd.

Average speaking fundamental frequency in soprano singers with and without symptoms of vocal attrition.

PubMed

Drew, R; Sapir, S

1995-06-01

Nineteen trained soprano singers aged 18-30 years vocalized tasks designed to assess average speaking fundamental frequency (SFF) during spontaneous speaking and reading. Vocal range and perceptual characteristics while singing with low intensity and high frequency were also assessed, and subjects completed a survey of vocal habits/symptoms. Recorded signals were digitized prior to being analyzed for SFF using the Kay Computerized Speech Lab program. Subjects were assigned to a normal voice or impaired voice group based on ratings of perceptual tasks and survey results. Data analysis showed group differences in mean SFF, no differences in vocal range, higher mean SFF values for reading than speaking, and 58% ability to perceive speaking in low pitch. The role of speaking in too low pitch as causal for vocal symptoms and need for voice classification differentiation in vocal performance studies are discussed.

Hydrogen Embrittlement And Stacking-Fault Energies

NASA Technical Reports Server (NTRS)

Parr, R. A.; Johnson, M. H.; Davis, J. H.; Oh, T. K.

1988-01-01

Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

The Combination of Just-in-Time Teaching and Wikispaces in Physics Classrooms

ERIC Educational Resources Information Center

Mohottala, Hashini E.

2013-01-01

The general student population enrolled in today's physics classrooms is diverse. They come from a variety of different educational backgrounds. Some demonstrate a good knowledge of natural laws of physics with a better understanding of mathematical concepts, while others show a fair knowledge in fundamentals of physics with a minimum knowledge in…

On Processing Chinese Ideographs and English Words: Some Implications from Stroop-Test Results.

ERIC Educational Resources Information Center

Biederman, Irving; Tsao, Yao-Chung

1979-01-01

When Chinese adults tried to name the color of characters which represented conflicting color words, they showed greater interference than did English speaking readers of the same task in English. This effect cannot be attributed to bilingualism. There may be fundamental differences in the perceptual demands of reading Chinese and English.…

Influence of stacking sequence on scattering characteristics of the fundamental anti-symmetric Lamb wave at through holes in composite laminates.

PubMed

Veidt, Martin; Ng, Ching-Tai

2011-03-01

This paper investigates the scattering characteristics of the fundamental anti-symmetric (A(0)) Lamb wave at through holes in composite laminates. Three-dimensional (3D) finite element (FE) simulations and experimental measurements are used to study the physical phenomenon. Unidirectional, bidirectional, and quasi-isotropic composite laminates are considered in the study. The influence of different hole diameter to wavelength aspect ratios and different stacking sequences on wave scattering characteristics are investigated. The results show that amplitudes and directivity distribution of the scattered Lamb wave depend on these parameters. In the case of quasi-isotropic composite laminates, the scattering directivity patterns are dominated by the fiber orientation of the outer layers and are quite different for composite laminates with the same number of laminae but different stacking sequence. The study provides improved physical insight into the scattering phenomena at through holes in composite laminates, which is essential to develop, validate, and optimize guided wave damage detection and characterization techniques. © 2011 Acoustical Society of America

Harmonic Brain Modes: A Unifying Framework for Linking Space and Time in Brain Dynamics.

PubMed

Atasoy, Selen; Deco, Gustavo; Kringelbach, Morten L; Pearson, Joel

2018-06-01

A fundamental characteristic of spontaneous brain activity is coherent oscillations covering a wide range of frequencies. Interestingly, these temporal oscillations are highly correlated among spatially distributed cortical areas forming structured correlation patterns known as the resting state networks, although the brain is never truly at "rest." Here, we introduce the concept of harmonic brain modes-fundamental building blocks of complex spatiotemporal patterns of neural activity. We define these elementary harmonic brain modes as harmonic modes of structural connectivity; that is, connectome harmonics, yielding fully synchronous neural activity patterns with different frequency oscillations emerging on and constrained by the particular structure of the brain. Hence, this particular definition implicitly links the hitherto poorly understood dimensions of space and time in brain dynamics and its underlying anatomy. Further we show how harmonic brain modes can explain the relationship between neurophysiological, temporal, and network-level changes in the brain across different mental states ( wakefulness, sleep, anesthesia, psychedelic). Notably, when decoded as activation of connectome harmonics, spatial and temporal characteristics of neural activity naturally emerge from the interplay between excitation and inhibition and this critical relation fits the spatial, temporal, and neurophysiological changes associated with different mental states. Thus, the introduced framework of harmonic brain modes not only establishes a relation between the spatial structure of correlation patterns and temporal oscillations (linking space and time in brain dynamics), but also enables a new dimension of tools for understanding fundamental principles underlying brain dynamics in different states of consciousness.

Vector dissipative soliton resonance in a fiber laser.

PubMed

Luo, Zhi-Chao; Ning, Qiu-Yi; Mo, Hai-Lan; Cui, Hu; Liu, Jin; Wu, Li-Jun; Luo, Ai-Ping; Xu, Wen-Cheng

2013-04-22

We report on the vector nature of rectangular pulse operating in dissipative soliton resonance (DSR) region in a passively mode-locked fiber laser. Apart from the typical signatures of DSR, the rectangular pulse trapping of two polarization components centered at different wavelengths was observed and they propagated as a group-velocity locked vector soliton. Moreover, the polarization resolved soliton spectra show different spectral distributions. The observed results will enhance the understanding of fundamental physics of DSR phenomenon.

Internal character dictates transition dynamics between isolation and cohesive grouping

NASA Astrophysics Data System (ADS)

Manrique, Pedro D.; Hui, Pak Ming; Johnson, Neil F.

2015-12-01

We show that accounting for internal character among interacting heterogeneous entities generates rich transition behavior between isolation and cohesive dynamical grouping. Our analytical and numerical calculations reveal different critical points arising for different character-dependent grouping mechanisms. These critical points move in opposite directions as the population's diversity decreases. Our analytical theory may help explain why a particular class of universality is so common in the real world, despite the fundamental differences in the underlying entities. It also correctly predicts the nonmonotonic temporal variation in connectivity observed recently in one such system.

Vibrational spectra, NLO analysis, and HOMO-LUMO studies of 2-chloro-6-fluorobenzoic acid and 3,4-dichlorobenzoic acid by density functional method

NASA Astrophysics Data System (ADS)

Senthil kumar, J.; Arivazhagan, M.; Thangaraju, P.

2015-08-01

The FTIR and FT-Raman spectra of 2-chloro-6-fluorobenzoic acid and 3,4-dichlorobenzoic acid have been recorded in the region 4000-400 cm-1 and 3500-50 cm-1, respectively. Utilizing the observed FTIR and FT-Raman data, a complete vibrational assignment and analysis of fundamental modes of the compounds were carried out. The optimized molecular geometries, vibrational frequencies, thermodynamic properties and atomic charge of the compounds were calculated by using density functional theory (B3LYP) method with 6-311+G and 6-311++G basis sets. The difference between the observed and scaled wave number values of most of fundamentals is very small. Unambiguous vibration assignment of all the fundamentals is made up the total energy distribution (TED). The calculated HOMO and LUMO energies show that charge transfer occurs within the molecules. Besides, molecular electro static potential (MESP), Mulliken's charge analysis, first order hyper polarizability and several thermodynamic properties were performed by the DFT method.

The Method of Fundamental Solutions using the Vector Magnetic Dipoles for Calculation of the Magnetic Fields in the Diagnostic Problems Based on Full-Scale Modelling Experiment

NASA Astrophysics Data System (ADS)

Bakhvalov, Yu A.; Grechikhin, V. V.; Yufanova, A. L.

2016-04-01

The article describes the calculation of the magnetic fields in the problems diagnostic of technical systems based on the full-scale modeling experiment. Use of gridless fundamental solution method and its variants in combination with grid methods (finite differences and finite elements) are allowed to considerably reduce the dimensionality task of the field calculation and hence to reduce calculation time. When implementing the method are used fictitious magnetic charges. In addition, much attention is given to the calculation accuracy. Error occurs when wrong choice of the distance between the charges. The authors are proposing to use vector magnetic dipoles to improve the accuracy of magnetic fields calculation. Examples of this approacharegiven. The article shows the results of research. They are allowed to recommend the use of this approach in the method of fundamental solutions for the full-scale modeling tests of technical systems.

Fundamental monogamy relation between contextuality and nonlocality.

PubMed

Kurzyński, Paweł; Cabello, Adán; Kaszlikowski, Dagomir

2014-03-14

We show that the no-disturbance principle imposes a tradeoff between locally contextual correlations violating the Klyachko-Can-Biniciogˇlu-Shumovski inequality and spatially separated correlations violating the Clauser-Horne-Shimony-Holt inequality. The violation of one inequality forbids the violation of the other. We also obtain the corresponding monogamy relation imposed by quantum theory for a qutrit-qubit system. Our results show the existence of fundamental monogamy relations between contextuality and nonlocality that suggest that entanglement might be a particular form of a more fundamental resource.

Are sex differences in fundamental motor skills uniform throughout the entire preschool period?

PubMed Central

2017-01-01

The aim of this study was to assess differences in fundamental motor skills (FMS) proficiency between boys and girls of each age group, independently, across the entire preschool period. Using the Movement Assessment Battery for Children–second edition, FMS proficiency was tested in 325 preschoolers (4.9 ± 1.1 y, range 3–6) using a cross-sectional design. Compared to boys of the same age, 3- and 4-year-old girls had greater total (p < .01), fine motor skill (p < .01), and balance scores (p < .05). There were no sex differences for total test or balance scores in 5- and 6-year-olds, but 6-year-old boys outperformed girls in aiming and catching (p < .001). These data not only agree with previous research in that sex differences in FMS proficiency exist in preschool children, but the data also show that differences may not be uniform throughout the whole preschool period when analyzing by age. To avoid under- or overestimating FMS proficiency and subsequently prescribing inaccurate motor intervention programs, FMS proficiency normative values should be age- and sex-specific throughout the entire preschool period. PMID:28448557

Different Paths to Some Fundamental Physical Laws: Relativistic Polarization of a Moving Magnetic Dipole

ERIC Educational Resources Information Center

Kholmetskii, Alexander L.; Yarman, T.

2010-01-01

In this paper we consider the relativistic polarization of a moving magnetic dipole and show that this effect can be understood via the relativistic generalization of Kirchhoff's first law to a moving closed circuit with a steady current. This approach allows us to better understand the law of relativistic transformation of four-current density…

Right Temporal Cortex is Critical for Utilization of Melodic Contextual Cues in a Pitch Constancy Task

ERIC Educational Resources Information Center

Warrier, Catherine M.; Zatorre, Robert J.

2004-01-01

Pitch constancy, perceiving the same pitch from tones with differing spectral shapes, requires one to extract the fundamental frequency from two sets of harmonics and compare them. We previously showed this difficult task to be easier when tonal context is present, presumably because the context creates a tonal reference point from which to judge…

Universal spin-momentum locked optical forces

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

Kalhor, Farid; Thundat, Thomas; Jacob, Zubin, E-mail: zjacob@purdue.edu

2016-02-08

Evanescent electromagnetic waves possess spin-momentum locking, where the direction of propagation (momentum) is locked to the inherent polarization of the wave (transverse spin). We study the optical forces arising from this universal phenomenon and show that the fundamental origin of recently reported non-trivial optical chiral forces is spin-momentum locking. For evanescent waves, we show that the direction of energy flow, the direction of decay, and the direction of spin follow a right hand rule for three different cases of total internal reflection, surface plasmon polaritons, and HE{sub 11} mode of an optical fiber. Furthermore, we explain how the recently reportedmore » phenomena of lateral optical force on chiral and achiral particles are caused by the transverse spin of the evanescent field and the spin-momentum locking phenomenon. Finally, we propose an experiment to identify the unique lateral forces arising from the transverse spin in the optical fiber and point to fundamental differences of the spin density from the well-known orbital angular momentum of light. Our work presents a unified view on spin-momentum locking and how it affects optical forces on chiral and achiral particles.« less

Tungstate adsorption onto Italian soils with different characteristics.

PubMed

Petruzzelli, Gianniantonio; Pedron, Francesca

2017-08-01

The study of tungsten in the environment is currently of considerable interest because of the growing concerns resulting from its possible toxicity and carcinogenicity. Adsorption reactions are some of the fundamental processes governing the fate and transport of tungsten compounds in soil. This paper reports data on the adsorption of tungstate ions in three different Italian soils, which are characteristic of the Mediterranean region. The results show that pH is the most important factor governing the adsorption of tungstate in these soils. The data interpreted according to the Langmuir equation show that the maximum value of adsorption is approximately 30 mmol kg -1 for the most acidic soil (pH = 4.50) and approximately 9 mmol kg -1 for the most basic soil (pH = 7.40). In addition, soil organic matter is shown to play a fundamental role in adsorption processes, which are favored in soils with a higher organic matter content. The data could contribute to a better understanding of the behavior of tungsten compounds in Italian soils for which current knowledge is very scarce, also in view of environmental regulations, which are currently lacking.

The Role for an Evaluator: A Fundamental Issue for Evaluation of Education and Social Programs

ERIC Educational Resources Information Center

Luo, Heng

2010-01-01

This paper discusses one of the fundamental issues in education and social program evaluation: the proper role for an evaluator. Based on respective and comparative analysis of five theorists' positions on this fundamental issue, this paper reveals how different perspectives on other fundamental issues in evaluation such as value, methods, use and…

A Channel Network Evolution Model with Subsurface Saturation Mechanism and Analysis of the Chaotic Behavior of the Model

DTIC Science & Technology

1990-09-01

between basin shapes and hydrologic responses is fundamental for the purpose of hydrologic predictions , especially in ungaged basins. Another goal is...47] studied this model and showed analitically how very small differences in the c field generated completely different leaf vein network structures... predictability impossible. Complexity is by no means a requirement in order for a system to exhibit SIC. A system as simple as the logistic equation x,,,,=ax,,(l

Mutual information based feature selection for medical image retrieval

NASA Astrophysics Data System (ADS)

Zhi, Lijia; Zhang, Shaomin; Li, Yan

2018-04-01

In this paper, authors propose a mutual information based method for lung CT image retrieval. This method is designed to adapt to different datasets and different retrieval task. For practical applying consideration, this method avoids using a large amount of training data. Instead, with a well-designed training process and robust fundamental features and measurements, the method in this paper can get promising performance and maintain economic training computation. Experimental results show that the method has potential practical values for clinical routine application.

Palatini actions and quantum gravity phenomenology

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

Olmo, Gonzalo J., E-mail: gonzalo.olmo@csic.es

2011-10-01

We show that an invariant an universal length scale can be consistently introduced in a generally covariant theory through the gravitational sector using the Palatini approach. The resulting theory is able to capture different aspects of quantum gravity phenomenology in a single framework. In particular, it is found that in this theory field excitations propagating with different energy-densities perceive different background metrics, which is a fundamental characteristic of the DSR and Rainbow Gravity approaches. We illustrate these properties with a particular gravitational model and explicitly show how the soccer ball problem is avoided in this framework. The isotropic and anisotropicmore » cosmologies of this model also avoid the big bang singularity by means of a big bounce.« less

Form and function in gene regulatory networks: the structure of network motifs determines fundamental properties of their dynamical state space.

PubMed

Ahnert, S E; Fink, T M A

2016-07-01

Network motifs have been studied extensively over the past decade, and certain motifs, such as the feed-forward loop, play an important role in regulatory networks. Recent studies have used Boolean network motifs to explore the link between form and function in gene regulatory networks and have found that the structure of a motif does not strongly determine its function, if this is defined in terms of the gene expression patterns the motif can produce. Here, we offer a different, higher-level definition of the 'function' of a motif, in terms of two fundamental properties of its dynamical state space as a Boolean network. One is the basin entropy, which is a complexity measure of the dynamics of Boolean networks. The other is the diversity of cyclic attractor lengths that a given motif can produce. Using these two measures, we examine all 104 topologically distinct three-node motifs and show that the structural properties of a motif, such as the presence of feedback loops and feed-forward loops, predict fundamental characteristics of its dynamical state space, which in turn determine aspects of its functional versatility. We also show that these higher-level properties have a direct bearing on real regulatory networks, as both basin entropy and cycle length diversity show a close correspondence with the prevalence, in neural and genetic regulatory networks, of the 13 connected motifs without self-interactions that have been studied extensively in the literature. © 2016 The Authors.

Sex-linked inheritance of host-plant specialization in a polyphagous butterfly

PubMed Central

Janz, N.

1998-01-01

I investigated the genetic background of intraspecific variation in oviposition specificity in the generalist butterfly Polygonia c-album. Using reciprocal crosses between two populations that differ in their degree of specialization, I show that specificity is strongly sex-linked. This indicates that genes determining this difference are located primarily on the paternally inherited X-chromosome. The results suggest that intraspecific differences in specificity are caused by the same genetic mechanisms that have been shown to determine interspecific differences in host-plant ranking in other butterflies. Accordingly, the common assumption that specialization and ranking are determined by fundamentally different mechanisms was not supported.

Integrating fundamental movement skills in late childhood.

PubMed

Gimenez, Roberto; Manoel, Edison de J; de Oliveira, Dalton Lustosa; Dantas, Luiz; Marques, Inara

2012-04-01

The study examined how children of different ages integrate fundamental movement skills, such as running and throwing, and whether their developmental status was related to the combination of these skills. Thirty children were divided into three groups (G1 = 6-year-olds, G2 = 9-year-olds, and G3 = 12-year-olds) and filmed performing three tasks: running, overarm throwing, and the combined task. Patterns were identified and described, and the efficiency of integration was calculated (distance differences of the ball thrown in two tasks, overarm throwing and combined task). Differences in integration were related to age: the 6-year-olds were less efficient in combining the two skills than the 9- and 12-year-olds. These differences may be indicative of a phase of integrating fundamental movement skills in the developmental sequence. This developmental status, particularly throwing, seems to be related to the competence to integrate skills, which suggests that fundamental movement skills may be developmental modules.

Irreconcilable difference between quantum walks and adiabatic quantum computing

NASA Astrophysics Data System (ADS)

Wong, Thomas G.; Meyer, David A.

2016-06-01

Continuous-time quantum walks and adiabatic quantum evolution are two general techniques for quantum computing, both of which are described by Hamiltonians that govern their evolutions by Schrödinger's equation. In the former, the Hamiltonian is fixed, while in the latter, the Hamiltonian varies with time. As a result, their formulations of Grover's algorithm evolve differently through Hilbert space. We show that this difference is fundamental; they cannot be made to evolve along each other's path without introducing structure more powerful than the standard oracle for unstructured search. For an adiabatic quantum evolution to evolve like the quantum walk search algorithm, it must interpolate between three fixed Hamiltonians, one of which is complex and introduces structure that is stronger than the oracle for unstructured search. Conversely, for a quantum walk to evolve along the path of the adiabatic search algorithm, it must be a chiral quantum walk on a weighted, directed star graph with structure that is also stronger than the oracle for unstructured search. Thus, the two techniques, although similar in being described by Hamiltonians that govern their evolution, compute by fundamentally irreconcilable means.

Single electron relativistic clock interferometer

NASA Astrophysics Data System (ADS)

Bushev, P. A.; Cole, J. H.; Sholokhov, D.; Kukharchyk, N.; Zych, M.

2016-09-01

Although time is one of the fundamental notions in physics, it does not have a unique description. In quantum theory time is a parameter ordering the succession of the probability amplitudes of a quantum system, while according to relativity theory each system experiences in general a different proper time, depending on the system's world line, due to time dilation. It is therefore of fundamental interest to test the notion of time in the regime where both quantum and relativistic effects play a role, for example, when different amplitudes of a single quantum clock experience different magnitudes of time dilation. Here we propose a realization of such an experiment with a single electron in a Penning trap. The clock can be implemented in the electronic spin precession and its time dilation then depends on the radial (cyclotron) state of the electron. We show that coherent manipulation and detection of the electron can be achieved already with present day technology. A single electron in a Penning trap is a technologically ready platform where the notion of time can be probed in a hitherto untested regime, where it requires a relativistic as well as quantum description.

Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

PubMed

Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

2016-03-29

Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

Alternative splicing modulates Kv channel clustering through a molecular ball and chain mechanism

NASA Astrophysics Data System (ADS)

Zandany, Nitzan; Marciano, Shir; Magidovich, Elhanan; Frimerman, Teddy; Yehezkel, Rinat; Shem-Ad, Tzilhav; Lewin, Limor; Abdu, Uri; Orr, Irit; Yifrach, Ofer

2015-03-01

Ion channel clustering at the post-synaptic density serves a fundamental role in action potential generation and transmission. Here, we show that interaction between the Shaker Kv channel and the PSD-95 scaffold protein underlying channel clustering is modulated by the length of the intrinsically disordered C terminal channel tail. We further show that this tail functions as an entropic clock that times PSD-95 binding. We thus propose a ‘ball and chain’ mechanism to explain Kv channel binding to scaffold proteins, analogous to the mechanism describing channel fast inactivation. The physiological relevance of this mechanism is demonstrated in that alternative splicing of the Shaker channel gene to produce variants of distinct tail lengths resulted in differential channel cell surface expression levels and clustering metrics that correlate with differences in affinity of the variants for PSD-95. We suggest that modulating channel clustering by specific spatial-temporal spliced variant targeting serves a fundamental role in nervous system development and tuning.

Sexual selection on male vocal fundamental frequency in humans and other anthropoids.

PubMed

Puts, David A; Hill, Alexander K; Bailey, Drew H; Walker, Robert S; Rendall, Drew; Wheatley, John R; Welling, Lisa L M; Dawood, Khytam; Cárdenas, Rodrigo; Burriss, Robert P; Jablonski, Nina G; Shriver, Mark D; Weiss, Daniel; Lameira, Adriano R; Apicella, Coren L; Owren, Michael J; Barelli, Claudia; Glenn, Mary E; Ramos-Fernandez, Gabriel

2016-04-27

In many primates, including humans, the vocalizations of males and females differ dramatically, with male vocalizations and vocal anatomy often seeming to exaggerate apparent body size. These traits may be favoured by sexual selection because low-frequency male vocalizations intimidate rivals and/or attract females, but this hypothesis has not been systematically tested across primates, nor is it clear why competitors and potential mates should attend to vocalization frequencies. Here we show across anthropoids that sexual dimorphism in fundamental frequency (F0) increased during evolutionary transitions towards polygyny, and decreased during transitions towards monogamy. Surprisingly, humans exhibit greater F0 sexual dimorphism than any other ape. We also show that low-F0 vocalizations predict perceptions of men's dominance and attractiveness, and predict hormone profiles (low cortisol and high testosterone) related to immune function. These results suggest that low male F0 signals condition to competitors and mates, and evolved in male anthropoids in response to the intensity of mating competition. © 2016 The Author(s).

Body mass index and acoustic voice parameters: is there a relationship.

PubMed

Souza, Lourdes Bernadete Rocha de; Santos, Marquiony Marques Dos

2017-05-06

Specific elements such as weight and body volume can interfere in voice production and consequently in its acoustic parameters, which is why it is important for the clinician to be aware of these relationships. To investigate the relationship between body mass index and the average acoustic voice parameters. Observational, cross-sectional descriptive study. The sample consisted of 84 women, aged between 18 and 40years, an average of 26.83 (±6.88). The subjects were grouped according to body mass index: 19 underweight; 23 normal ranges, 20 overweight and 22 obese and evaluated the fundamental frequency of the sustained vowel [a] and the maximum phonation time of the vowels [a], [i], [u], using PRAAT software. The data were submitted to the Kruskal-Wallis test to verify if there were differences between the groups regarding the study variables. All variables showed statistically significant results and were subjected to non-parametric test Mann-Whitney. Regarding to the average of the fundamental frequency, there was statistically significant difference between groups with underweight and overweight and obese; normal range and overweight and obese. The average maximum phonation time revealed statistically significant difference between underweight and obese individuals; normal range and obese; overweight and obese. Body mass index influenced the average fundamental frequency of overweight and obese individuals evaluated in this study. Obesity influenced in reducing maximum phonation time average. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Different methods and metaphysics in early molecular genetics--a case of disparity of research?

PubMed

Deichmann, Ute

2008-01-01

The encounter between two fundamentally different approaches in seminal research in molecular biology--the problems, aims, methods and metaphysics--is delineated and analyzed. They are exemplified by the microbiologist Oswald T. Avery who, in line with the reductionist mechanistic metaphysics of Jacques Loeb, attempted to explain basic life phenomena through chemistry; and the theoretical physicist Max Delbrück who, influenced by Bohr's antimechanistic views, preferred to explain these phenomena without chemistry. Avery's and Delbrück's most important studies took place concurrently. Thus analysis of their contrasting approaches lends itself to examination of the Weltanschauungen view concerning the role of fundamental (metaphysical) assumptions in scientific change, that is, the view that empirical research cannot be neutral in regard to the worldviews of the researchers. This study shows that the initial ostensible disparity (non-integratibility) of the two approaches lasted for just a short time. Ironically it was a student of Delbrück's school, James Watson, who (with Crick) proposed a chemical model, the DNA double helix, as a solution to Delbrück's problem. The structure of DNA has not been seriously challenged over the past half century Moreover, Watson's and Crick's work did not call into question the validity of Delbrück's research, but opened it up to entirely new approaches. The case of Avery and Delbrück demonstrates that after initial obstacles were overcome the different fundamental attitudes and the resulting research practices were capable of integration.

Hardware-based Artificial Neural Networks for Size, Weight, and Power Constrained Platforms (Preprint)

DTIC Science & Technology

2012-11-01

few sensors/complex computations, and many sensors/simple computation. II. CHALLENGES WITH NANO-ENABLED NEUROMORPHIC CHIPS A wide variety of...scenarios. Neuromorphic processors, which are based on the highly parallelized computing architecture of the mammalian brain, show great promise in...in the brain. This fundamentally different approach, frequently referred to as neuromorphic computing, is thought to be better able to solve fuzzy

If All You Have Is a Hammer, Everything Begins to Look Like a Nail--How Wicked Is the Problem of Measuring Productivity in Higher Education?

ERIC Educational Resources Information Center

Drengenberg, Nicholas; Bain, Alan

2017-01-01

This paper addresses the wicked problem of measuring the productivity of learning and teaching in higher education. We show how fundamental validity issues and difficulties identified in educational productivity research point to the need for a qualitatively different framework when considering the entire question. We describe the work that needs…

Type 3 Fimbriae Encoded on Plasmids Are Expressed from a Unique Promoter without Affecting Host Motility, Facilitating an Exceptional Phenotype That Enhances Conjugal Plasmid Transfer

PubMed Central

Madsen, Jonas Stenløkke; Riber, Leise; Kot, Witold; Basfeld, Alrun; Burmølle, Mette; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

2016-01-01

Horizontal gene transfer (HGT), the transmission of genetic material to a recipient that is not the progeny of the donor, is fundamental in bacterial evolution. HGT is often mediated by mobile genetic elements such as conjugative plasmids, which may be in conflict with the chromosomal elements of the genome because they are independent replicons that may petition their own evolutionary strategy. Here we study differences between type 3 fimbriae encoded on wild type plasmids and in chromosomes. Using known and newly characterized plasmids we show that the expression of type 3 fimbriae encoded on plasmids is systematically different, as MrkH, a c-di-GMP dependent transcriptional activator is not needed for strong expression of the fimbriae. MrkH is required for expression of type 3 fimbriae of the Klebsiella pneumoniae chromosome, wherefrom the fimbriae operon (mrkABCDF) of plasmids is believed to have originated. We find that mrkABCDFs of plasmids are highly expressed via a unique promoter that differs from the original Klebsiella promoter resulting in fundamental behavioral consequences. Plasmid associated mrkABCDFs did not influence the swimming behavior of the host, that hereby acquired an exceptional phenotype being able to both actively swim (planktonic behavior) and express biofilm associated fimbriae (sessile behavior). We show that this exceptional phenotype enhances the conjugal transfer of the plasmid. PMID:27627107

Fundamental Tactical Principles of Soccer: A Comparison of Different Age Groups

PubMed Central

Guilherme, José; Rechenchosky, Leandro; da Costa, Luciane Cristina Arantes; Rinadi, Wilson

2017-01-01

Abstract The fundamental tactical principles of the game of soccer represent a set of action rules that guide behaviours related to the management of game space. The aim of this study was to compare the performance of fundamental offensive and defensive tactical principles among youth soccer players from 12 to 17 years old. The sample consisted of 3689 tactical actions performed by 48 soccer players in three age categories: under 13 (U-13), under 15 (U-15), and under 17 (U-17). Tactical performance was measured using the System of Tactical Assessment in Soccer (FUT-SAT). The Kruskal Wallis, Mann-Whitney U, Friedman, Wilcoxon, and Cohen’s Kappa tests were used in the study analysis. The results showed that the principles of “offensive coverage” (p = 0.01) and “concentration” (p = 0.04) were performed more frequently by the U-17 players than the U-13 players. The tactical principles “width and length” (p < 0.05) and “defensive unit” (p < 0.05) were executed more frequently by younger soccer players. It can be concluded that the frequency with which fundamental tactical principles are performed varies between the gaming categories, which implies that there is valuation of defensive security and a progressive increase in “offensive coverage” caused by increased confidence and security in offensive actions. PMID:28828091

Fundamental Tactical Principles of Soccer: A Comparison of Different Age Groups.

PubMed

Borges, Paulo Henrique; Guilherme, José; Rechenchosky, Leandro; da Costa, Luciane Cristina Arantes; Rinadi, Wilson

2017-09-01

The fundamental tactical principles of the game of soccer represent a set of action rules that guide behaviours related to the management of game space. The aim of this study was to compare the performance of fundamental offensive and defensive tactical principles among youth soccer players from 12 to 17 years old. The sample consisted of 3689 tactical actions performed by 48 soccer players in three age categories: under 13 (U-13), under 15 (U-15), and under 17 (U-17). Tactical performance was measured using the System of Tactical Assessment in Soccer (FUT-SAT). The Kruskal Wallis, Mann-Whitney U, Friedman, Wilcoxon, and Cohen's Kappa tests were used in the study analysis. The results showed that the principles of "offensive coverage" (p = 0.01) and "concentration" (p = 0.04) were performed more frequently by the U-17 players than the U-13 players. The tactical principles "width and length" (p < 0.05) and "defensive unit" (p < 0.05) were executed more frequently by younger soccer players. It can be concluded that the frequency with which fundamental tactical principles are performed varies between the gaming categories, which implies that there is valuation of defensive security and a progressive increase in "offensive coverage" caused by increased confidence and security in offensive actions.

Piezoelectric Lead Zirconate Titanate (PZT) Ring Shaped Contour-Mode MEMS Resonators

NASA Astrophysics Data System (ADS)

Kasambe, P. V.; Asgaonkar, V. V.; Bangera, A. D.; Lokre, A. S.; Rathod, S. S.; Bhoir, D. V.

2018-02-01

Flexibility in setting fundamental frequency of resonator independent of its motional resistance is one of the desired criteria in micro-electromechanical (MEMS) resonator design. It is observed that ring-shaped piezoelectric contour-mode MEMS resonators satisfy this design criterion than in case of rectangular plate MEMS resonators. Also ring-shaped contour-mode piezoelectric MEMS resonator has an advantage that its fundamental frequency is defined by in-plane dimensions, but they show variation of fundamental frequency with different Platinum (Pt) thickness referred as change in ratio of fNEW /fO . This paper presents the effects of variation in geometrical parameters and change in piezoelectric material on the resonant frequencies of Platinum piezoelectric-Aluminium ring-shaped contour-mode MEMS resonators and its electrical parameters. The proposed structure with Lead Zirconate Titanate (PZT) as the piezoelectric material was observed to be a piezoelectric material with minimal change in fundamental resonant frequency due to Platinum thickness variation. This structure was also found to exhibit extremely low motional resistance of 0.03 Ω as compared to the 31-35 Ω range obtained when using AlN as the piezoelectric material. CoventorWare 10 is used for the design, simulation and corresponding analysis of resonators which is Finite Element Method (FEM) analysis and design tool for MEMS devices.

Behaviour of mathematics and physics students in solving problem of Vector-Physics context

NASA Astrophysics Data System (ADS)

Sardi; Rizal, M.; Mansyur, J.

2018-04-01

This research aimed to describe behaviors of mathematics and physics students in solving problem of the vector concept in physics context. The subjects of the research were students who enrolled in Mathematics Education Study Program and Physics Education Study Program of FKIP Universitas Tadulako. The selected participants were students who received the highest score in vector fundamental concept test in each study program. The data were collected through thinking-aloud activity followed by an interview. The steps of data analysis included data reduction, display, and conclusion drawing. The credibility of the data was tested using a triangulation method. Based on the data analysis, it can be concluded that the two groups of students did not show fundamental differences in problem-solving behavior, especially in the steps of understanding the problem (identifying, collecting and analyzing facts and information), planning (looking for alternative strategies) and conducting the alternative strategy. The two groups were differ only in the evaluation aspect. In contrast to Physics students who evaluated their answer, mathematics students did not conducted an evaluation activity on their work. However, the difference was not caused by the differences in background knowledge.

The relative entropy is fundamental to adaptive resolution simulations

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

Kreis, Karsten; Graduate School Materials Science in Mainz, Staudingerweg 9, 55128 Mainz; Potestio, Raffaello, E-mail: potestio@mpip-mainz.mpg.de

Adaptive resolution techniques are powerful methods for the efficient simulation of soft matter systems in which they simultaneously employ atomistic and coarse-grained (CG) force fields. In such simulations, two regions with different resolutions are coupled with each other via a hybrid transition region, and particles change their description on the fly when crossing this boundary. Here we show that the relative entropy, which provides a fundamental basis for many approaches in systematic coarse-graining, is also an effective instrument for the understanding of adaptive resolution simulation methodologies. We demonstrate that the use of coarse-grained potentials which minimize the relative entropy withmore » respect to the atomistic system can help achieve a smoother transition between the different regions within the adaptive setup. Furthermore, we derive a quantitative relation between the width of the hybrid region and the seamlessness of the coupling. Our results do not only shed light on the what and how of adaptive resolution techniques but will also help setting up such simulations in an optimal manner.« less

Piezo-Hall effect and fundamental piezo-Hall coefficients of single crystal n-type 3C-SiC(100) with low carrier concentration

NASA Astrophysics Data System (ADS)

Qamar, Afzaal; Dao, Dzung Viet; Dinh, Toan; Iacopi, Alan; Walker, Glenn; Phan, Hoang-Phuong; Hold, Leonie; Dimitrijev, Sima

2017-04-01

This article reports the results on the piezo-Hall effect in single crystal n-type 3C-SiC(100) having a low carrier concentration. The effect of the crystallographic orientation on the piezo-Hall effect has been investigated by applying stress to the Hall devices fabricated in different crystallographic directions. Single crystal n-type 3C-SiC(100) and 3C-SiC(111) were grown by low pressure chemical vapor deposition at 1250 °C. Fundamental piezo-Hall coefficients were obtained using the piezo-Hall effect measurements as P11 = (-29 ± 1.3) × 10-11 Pa-1, P12 = (11.06 ± 0.5)× 10-11 Pa-1, and P44 = (-3.4 ± 0.7) × 10-11 Pa-1. It has been observed that the piezo-Hall coefficients of n-type 3C-SiC(100) show a completely different behavior as compared to that of p-type 3C-SiC.

Unconventional Current Scaling and Edge Effects for Charge Transport through Molecular Clusters

PubMed Central

2017-01-01

Metal–molecule–metal junctions are the key components of molecular electronics circuits. Gaining a microscopic understanding of their conducting properties is central to advancing the field. In the present contribution, we highlight the fundamental differences between single-molecule and ensemble junctions focusing on the fundamentals of transport through molecular clusters. In this way, we elucidate the collective behavior of parallel molecular wires, bridging the gap between single molecule and large-area monolayer electronics, where even in the latter case transport is usually dominated by finite-size islands. On the basis of first-principles charge-transport simulations, we explain why the scaling of the conductivity of a junction has to be distinctly nonlinear in the number of molecules it contains. Moreover, transport through molecular clusters is found to be highly inhomogeneous with pronounced edge effects determined by molecules in locally different electrostatic environments. These effects are most pronounced for comparably small clusters, but electrostatic considerations show that they prevail also for more extended systems. PMID:29043825

Statistical Physics Approaches to Microbial Ecology

NASA Astrophysics Data System (ADS)

Mehta, Pankaj

The unprecedented ability to quantitatively measure and probe complex microbial communities has renewed interest in identifying the fundamental ecological principles governing community ecology in microbial ecosystems. Here, we present work from our group and others showing how ideas from statistical physics can help us uncover these ecological principles. Two major lessons emerge from this work. First, large, ecosystems with many species often display new, emergent ecological behaviors that are absent in small ecosystems with just a few species. To paraphrase Nobel laureate Phil Anderson, ''More is Different'', especially in community ecology. Second, the lack of trophic layer separation in microbial ecology fundamentally distinguishes microbial ecology from classical paradigms of community ecology and leads to qualitative different rules for community assembly in microbes. I illustrate these ideas using both theoretical modeling and novel new experiments on large microbial ecosystems performed by our collaborators (Joshua Goldford and Alvaro Sanchez). Work supported by Simons Investigator in MMLS and NIH R35 R35 GM119461.

The relative entropy is fundamental to adaptive resolution simulations

NASA Astrophysics Data System (ADS)

Kreis, Karsten; Potestio, Raffaello

2016-07-01

Adaptive resolution techniques are powerful methods for the efficient simulation of soft matter systems in which they simultaneously employ atomistic and coarse-grained (CG) force fields. In such simulations, two regions with different resolutions are coupled with each other via a hybrid transition region, and particles change their description on the fly when crossing this boundary. Here we show that the relative entropy, which provides a fundamental basis for many approaches in systematic coarse-graining, is also an effective instrument for the understanding of adaptive resolution simulation methodologies. We demonstrate that the use of coarse-grained potentials which minimize the relative entropy with respect to the atomistic system can help achieve a smoother transition between the different regions within the adaptive setup. Furthermore, we derive a quantitative relation between the width of the hybrid region and the seamlessness of the coupling. Our results do not only shed light on the what and how of adaptive resolution techniques but will also help setting up such simulations in an optimal manner.

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

Stoynov, Y.

Functionally graded materials (FGM) are extensively used in modern industry. They are composite materials with continuously varying properties in one or more special dimensions, according to the specific purpose. In view of the wide range of applications of FGM, stress analysis is important for their structural integrity and reliable service life. In this study we will consider functionally graded magneto-electro-elastic materials with one or more cracks subjected to SH waves. We assume that the material properties vary in one and the same way, described by an inhomogeneity function. The boundary value problem is reduced to a system of integro-differential equationsmore » based on the existence of fundamental solutions. Different inhomogeneity classes are used to obtain a wave equation with constant coefficients. Radon transform is applied to derive the fundamental solution in a closed form. Program code in FORTRAN 77 is developed and validated using available examples from literature. Simulations show the dependence of stress field concentration near the crack tips on the frequency of the applied time-harmonic load for different types of material inhomogeneity.« less

Some Effects of Compressibility on the Flow Through Fans and Turbines

NASA Technical Reports Server (NTRS)

Perl, W.; Epstein, H. T.

1946-01-01

The laws of conservation of mass, momentum, and energy are applied to the compressible flow through a two-dimensional cascade of airfoils. A fundamental relation between the ultimate upstream and downstream flow angles, the inlet Mach number, and the pressure ratio across the cascade is derived. Comparison with the corresponding relation for incompressible flow shows large differences. The fundamental relation reveals two ranges of flow angles and inlet Mach numbers, for which no ideal pressure ratio exists. One of these nonideal operating ranges is analogous to a similar type in incompressible flow. The other is characteristic only of compressible flow. The effect of variable axial-flow area is treated. Some implications of the basic conservation laws in the case of nonideal flow through cascades are discussed.

Fractal growth of platinum electrodeposits revealed by in situ electron microscopy.

PubMed

Wang, Lifen; Wen, Jianguo; Sheng, Huaping; Miller, Dean J

2016-10-06

Fractals are commonly observed in nature and elucidating the mechanisms of fractal-related growth is a compelling issue for both fundamental science and technology. Here we report an in situ electron microscopy study of dynamic fractal growth of platinum during electrodeposition in a miniaturized electrochemical cell at varying growth conditions. Highly dendritic growth - either dense branching or ramified islands - are formed at the solid-electrolyte interface. We show how the diffusion length of ions in the electrolyte influences morphology selection and how instability induced by initial surface roughness, combined with local enhancement of electric field, gives rise to non-uniform branched deposition as a result of nucleation/growth at preferred locations. Comparing the growth behavior under these different conditions provides new insight into the fundamental mechanisms of platinum nucleation.

A stable systemic risk ranking in China's banking sector: Based on principal component analysis

NASA Astrophysics Data System (ADS)

Fang, Libing; Xiao, Binqing; Yu, Honghai; You, Qixing

2018-02-01

In this paper, we compare five popular systemic risk rankings, and apply principal component analysis (PCA) model to provide a stable systemic risk ranking for the Chinese banking sector. Our empirical results indicate that five methods suggest vastly different systemic risk rankings for the same bank, while the combined systemic risk measure based on PCA provides a reliable ranking. Furthermore, according to factor loadings of the first component, PCA combined ranking is mainly based on fundamentals instead of market price data. We clearly find that price-based rankings are not as practical a method as fundamentals-based ones. This PCA combined ranking directly shows systemic risk contributions of each bank for banking supervision purpose and reminds banks to prevent and cope with the financial crisis in advance.

Thermalization and prethermalization in isolated quantum systems: a theoretical overview

NASA Astrophysics Data System (ADS)

Mori, Takashi; Ikeda, Tatsuhiko N.; Kaminishi, Eriko; Ueda, Masahito

2018-06-01

The approach to thermal equilibrium, or thermalization, in isolated quantum systems is among the most fundamental problems in statistical physics. Recent theoretical studies have revealed that thermalization in isolated quantum systems has several remarkable features, which emerge from quantum entanglement and are quite distinct from those in classical systems. Experimentally, well isolated and highly controllable ultracold quantum gases offer an ideal testbed to study the nonequilibrium dynamics in isolated quantum systems, promoting intensive recent theoretical endeavors on this fundamental subject. Besides thermalization, many isolated quantum systems show intriguing behavior in relaxation processes, especially prethermalization. Prethermalization occurs when there is a clear separation of relevant time scales and has several different physical origins depending on individual systems. In this review, we overview theoretical approaches to the problems of thermalization and prethermalization.

Stress Energy tensor in LCFT and the Logarithmic Sugawara construction

NASA Astrophysics Data System (ADS)

Kogan, Ian I.; Nichols, Alexander

2002-01-01

We discuss the partners of the stress energy tensor and their structure in Logarithmic conformal field theories. In particular we draw attention to the fundamental differences between theories with zero and non-zero central charge. However they are both characterised by at least two independent parameters. We show how, by using a generalised Sugawara construction, one can calculate the logarithmic partner of T. We show that such a construction works in the c = -2 theory using the conformal dimension one primary currents which generate a logarithmic extension of the Kac-Moody algebra.

Galileo, measurement of the velocity of light, and the reaction times.

PubMed

Foschi, Renato; Leone, Matteo

2009-01-01

According to the commonly accepted view, Galileo Galilei devised in 1638 an experiment that seemed able to show that the velocity of light is finite. An analysis of archival material shows that two decades later members of the Florence scientific society Accademia del Cimento followed Galileo guidelines by actually attempting to measure the velocity of light and suggesting improvements. This analysis also reveals a fundamental difference between Galileo's and Florence academy's methodologies and that Galileo's experiment was, in some respects, a pioneering work affecting also the history of the psychology of perception.

Differences in fundamental and functional properties of HPMC co-processed fillers prepared by fluid-bed coating and spray drying.

PubMed

Dong, QianQian; Zhou, MiaoMiao; Lin, Xiao; Shen, Lan; Feng, Yi

2018-07-01

This study aimed to develop novel co-processed tablet fillers based on the principle of particle engineering for direct compaction and to compare the characteristics of co-processed products obtained by fluid-bed coating and co-spray drying, respectively. Water-soluble mannitol and water-insoluble calcium carbonate were selected as representative fillers for this study. Hydroxypropyl methylcellulose (HPMC), serving as a surface property modifier, was distributed on the surface of primary filler particles via the two co-processing methods. Both fundamental and functional properties of the products were comparatively investigated. The results showed that functional properties of the fillers, like flowability, compactibility, and drug-loading capacity, were effectively improved by both co-processing methods. However, fluid-bed coating showed greater advantages over co-spray drying in some aspects, which was mainly attributed to the remarkable differences in some fundamental properties of co-processed powders, like particle size, surface topology, and particle structure. For example, the more irregular surface and porous structure induced by fluid-bed coating could contribute to better compaction properties and lower lubricant sensitivity due to the increasing contact area and mechanical interlocking between particles under pressure. More effective surface distribution of HPMC during fluid-bed coating was also a contributor. In addition, such a porous agglomerate structure could also reduce the separation of drug and excipients after mixing, resulting in the improvement in drug loading capacity and tablet uniformity. In summary, fluid-bed coating appears to be more promising for co-processing than spray drying in some aspects, and co-processed excipients produced by it have a great prospect for further investigations and development. Copyright © 2018 Elsevier B.V. All rights reserved.

An injection-locked OEO based frequency doubler independent of electrical doubler phase noise deteriorating rule

NASA Astrophysics Data System (ADS)

Xie, Zhengyang; Zheng, Xiaoping; Li, Shangyuan; Yan, Haozhe; Xiao, Xuedi; Xue, Xiaoxiao

2018-06-01

We propose an injection-locked optoelectronic oscillator (OEO) based wide-band frequency doubler, which is free from phase noise deterioration in electrical doubler, by using a dual-parallel Mach-Zehnder modulator (DPMZM). Through adjusting the optical phase shifts in different arms of the DPMZM, the doubling signal oscillates in the OEO loop while the fundamental signal takes on phase modulation over the light and vanishes at photo-detector (PD) output. By controlling power of fundamental signal the restriction of phase-noise deterioration rule in electrical doubler is totally canceled. Experimental results show that the doubler output has a better phase noise value of, for example, -117 dBc/Hz @ 10 kHz at 6 GHz with an improvement more than 17 dB and 23 dB compared with that of fundamental input and electrical doubler, respectively. Besides, the stability of this doubler output can reach to 1 . 5 × 10-14 at 1000 s averaging time. The frequency range of doubling signal is limited by the bandwidth of electrical amplifier in OEO loop.

Commissioning of the new AGS MMPS transformers

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

Bajon,E.; Badea, V. S.; Bannon, M.

The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps. +/-9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. During rectify and invert operation the P Bank power supplies are used. During the flattops the F Bank power supplies are used. The P Bank power supplies are fed from two 23 MVA transformers and the F Bank power supplies are fed from two 5.3 MYA transformers. The fundamental frequency of the F Bank power supplies is 1440 Hz, however the fundamental frequencymore » of the P banks was 720 Hz. It was very important to reduce the ripple during rectify to improve polarized proton operations. For this reason and also because the original transformers were 45 years old we replaced these transformers with new ones and we made the fundamental frequency of both P and F banks 1440 Hz. This paper will highlight the major hurdles that were involved during the installation of the new transformers. It will present waveforms while running at different power levels up to 6MW full load. It will show the transition from the F-Bank power supplies to the P-Banks and also show the improvements in ripple made on the P-Bank power supplies.« less

Concurrent visual and tactile steady-state evoked potentials index allocation of inter-modal attention: a frequency-tagging study.

PubMed

Porcu, Emanuele; Keitel, Christian; Müller, Matthias M

2013-11-27

We investigated effects of inter-modal attention on concurrent visual and tactile stimulus processing by means of stimulus-driven oscillatory brain responses, so-called steady-state evoked potentials (SSEPs). To this end, we frequency-tagged a visual (7.5Hz) and a tactile stimulus (20Hz) and participants were cued, on a trial-by-trial basis, to attend to either vision or touch to perform a detection task in the cued modality. SSEPs driven by the stimulation comprised stimulus frequency-following (i.e. fundamental frequency) as well as frequency-doubling (i.e. second harmonic) responses. We observed that inter-modal attention to vision increased amplitude and phase synchrony of the fundamental frequency component of the visual SSEP while the second harmonic component showed an increase in phase synchrony, only. In contrast, inter-modal attention to touch increased SSEP amplitude of the second harmonic but not of the fundamental frequency, while leaving phase synchrony unaffected in both responses. Our results show that inter-modal attention generally influences concurrent stimulus processing in vision and touch, thus, extending earlier audio-visual findings to a visuo-tactile stimulus situation. The pattern of results, however, suggests differences in the neural implementation of inter-modal attentional influences on visual vs. tactile stimulus processing. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of differential habitat warming on complex communities.

PubMed

Tunney, Tyler D; McCann, Kevin S; Lester, Nigel P; Shuter, Brian J

2014-06-03

Food webs unfold across a mosaic of micro and macro habitats, with each habitat coupled by mobile consumers that behave in response to local environmental conditions. Despite this fundamental characteristic of nature, research on how climate change will affect whole ecosystems has overlooked (i) that climate warming will generally affect habitats differently and (ii) that mobile consumers may respond to this differential change in a manner that may fundamentally alter the energy pathways that sustain ecosystems. This reasoning suggests a powerful, but largely unexplored, avenue for studying the impacts of climate change on ecosystem functioning. Here, we use lake ecosystems to show that predictable behavioral adjustments to local temperature differentials govern a fundamental structural shift across 54 food webs. Data show that the trophic pathways from basal resources to a cold-adapted predator shift toward greater reliance on a cold-water refuge habitat, and food chain length increases, as air temperatures rise. Notably, cold-adapted predator behavior may substantially drive this decoupling effect across the climatic range in our study independent of warmer-adapted species responses (for example, changes in near-shore species abundance and predator absence). Such modifications reflect a flexible food web architecture that requires more attention from climate change research. The trophic pathway restructuring documented here is expected to alter biomass accumulation, through the regulation of energy fluxes to predators, and thus potentially threatens ecosystem sustainability in times of rapid environmental change.

A Valid Demonstration of the Missing Fundamental Illusion.

ERIC Educational Resources Information Center

Larsen, Janet D.; Fritsch, Klaus

1998-01-01

Identifies the "missing fundamental illusion" as that which occurs when two tones are heard together and the listener hears a third tone with a pitch corresponding to the difference in their frequencies. Describes an inexpensive and valid demonstration of the missing fundamental using a British police whistle. (MJP)

An Initial Study of the Fundamentals of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory

NASA Technical Reports Server (NTRS)

Struk, Peter; Bartkus, Tadas; Tsao, Jen-Ching; Bencic, Timothy; King, Michael; Ratvasky, Thomas; Van Zante, Judith

2017-01-01

This presentation shows results from an initial study of the fundamental physics of ice-crystal ice accretion using the NASA Propulsion Systems Lab (PSL). Ice accretion due to the ingestion of ice-crystals is being attributed to numerous jet-engine power-loss events. The NASA PSL is an altitude jet-engine test facility which has recently added a capability to inject ice particles into the flow. NASA is evaluating whether this facility, in addition to full-engine and motor-driven-rig tests, can be used for more fundamental ice-accretion studies that simulate the different mixed-phase icing conditions along the core flow passage of a turbo-fan engine compressor. The data from such fundamental accretion tests will be used to help develop and validate models of the accretion process. The present study utilized a NACA0012 airfoil. The mixed-phase conditions were generated by partially freezing the liquid-water droplets ejected from the spray bars. This presentation shows data regarding (1) the freeze out characteristics of the cloud, (2) changes in aerothermal conditions due to the presence of the cloud, and (3) the ice accretion characteristics observed on the airfoil model. The primary variable in this test was the PSL plenum humidity which was systematically varied for two duct-exit-plane velocities (85 and 135 ms) as well as two particle size clouds (15 and 50 m MVDi). The observed clouds ranged from fully glaciated to fully liquid, where the liquid clouds were at least partially supercooled. The air total temperature decreased at the test section when the cloud was activated due to evaporation. The ice accretions observed ranged from sharp arrow-like accretions, characteristic of ice-crystal erosion, to cases with double-horn shapes, characteristic of supercooled water accretions.

Testing the Definition of the ESC Envelope

NASA Technical Reports Server (NTRS)

Vincent, Mark A.

2017-01-01

The previous effort, including a successful Change Control Request, addressed shrinking the size of the Earth Science Constellations' (ESC) Envelope by reducing the Margin. Fundamental to the purpose of the Envelope is the case where the argument of perigee of the secondary object circulates from 90 degrees to 270 degrees. This ("outside of the envelope, always outside the envelope") case was tested both numerically in a spreadsheet and analytically. Results showed how it is important to include the fact that a secondary with a different semi-major axis has a different frozen eccentricity value.

Whose drag is it anyway? Drag kings and monarchy in the UK.

PubMed

Willox, Annabelle

2002-01-01

This chapter will show that the term "drag" in drag queen has a different meaning, history and value to the term "drag" in drag king. By exposing this basic, yet fundamental, difference this paper will expose the problems inherent in the assumption of parity between the two forms of drag. An exposition of how camp has been used to comprehend and theorise drag queens will facilitating an understanding of the parasitic interrelationship between camp and drag queen performances, while a critique of "Towards a Butch-Femme Aesthetic," by Sue Ellen Case, will point out the problematic assumptions made about camp when attributed to a cultural location different to the drag queen. By interrogating the historical, cultural and theoretical similarities and differences between drag kings, butches, drag queens and femmes this paper will expose the flawed assumption that camp can be attributed to all of the above without proviso, and hence expose why drag has a fundamentally different contextual meaning for kings and queens. This chapter will conclude by examining the work of both Judith Halberstam and Biddy Martin and the practical examples of drag king and queen performances provided at the UK drag contest held at The Fridge in Brixton, London on 23 June 1999.

Racial Differences in Stage at Diagnosis and Survival from Epithelial Ovarian Cancer: A Fundamental Cause of Disease Approach

PubMed Central

Dolecek, Therese A; Davis, Faith G

2011-01-01

Associations between race, socioeconomic status (SES) and health outcomes have been well established. One of the ways in which race and SES affect health is by influencing one’s access to resources, which confers ability to avoid or mitigate adverse outcomes. The fundamental cause of disease approach argues that when a new screening tool is introduced, individuals with greater resources tend to have better access to the innovation, thus benefiting from early detection and leading to better survival. Conversely, when there is no established screening tool, racial and SES differences in early detection may be less pronounced. Most ovarian cancer is diagnosed at advanced stages, because of the lack of an effective screening tool and few early symptoms. However, once detected, racial differences may still be observed in mortality and survival outcomes. We examined the racial differences in diagnosis and survival among ovarian cancer cases diagnosed during 1994–1998, in Cook County, Illinois (N=351). There were no racial differences in the stage at diagnosis: 51.7% of white and 52.9% of black women were diagnosed at later stages (III and IV). Only age was associated with the stage at diagnosis. Tumor characteristics also did not differ between white and black women. Compared to white women, black women were less likely to be married, less educated, more frequently used genital powder, had tubal ligation, and resided in higher poverty census tracts. As of December 31, 2005, 44.3% of white and 54.5% of black women had died of ovarian cancer. Controlling for known confounding variables, the hazard ratio for ovarian cancer death between black and white women was 2.2. The findings show that fundamental cause perspective provides a potential framework to explore subtleties in racial disparities, with which broader social causes may be accounted for in explaining post diagnosis racial differences. PMID:20483517

What determines the morphological fractions in clusters of galaxies?

NASA Technical Reports Server (NTRS)

Whitmore, Bradley C.

1993-01-01

A reexamination of Dressler's (1980) sample of nearly 6000 galaxies in 55 clusters shows that the morphology-clustercentric radius relation is more fundamental than the morphology-local density relation. This conclusion is supported by improved correlations when the projected clustercentric radius is used as the independent parameter, and by a comparison of galaxies with the same normalized clustercentric radii by different values of the projected local density.

The Computational Complexity of Valuation and Motivational Forces in Decision-Making Processes.

PubMed

Redish, A David; Schultheiss, Nathan W; Carter, Evan C

2016-01-01

The concept of value is fundamental to most theories of motivation and decision making. However, value has to be measured experimentally. Different methods of measuring value produce incompatible valuation hierarchies. Taking the agent's perspective (rather than the experimenter's), we interpret the different valuation measurement methods as accessing different decision-making systems and show how these different systems depend on different information processing algorithms. This identifies the translation from these multiple decision-making systems into a single action taken by a given agent as one of the most important open questions in decision making today. We conclude by looking at how these different valuation measures accessing different decision-making systems can be used to understand and treat decision dysfunction such as in addiction.

Multi-scale compositionality: identifying the compositional structures of social dynamics using deep learning.

PubMed

Peng, Huan-Kai; Marculescu, Radu

2015-01-01

Social media exhibit rich yet distinct temporal dynamics which cover a wide range of different scales. In order to study this complex dynamics, two fundamental questions revolve around (1) the signatures of social dynamics at different time scales, and (2) the way in which these signatures interact and form higher-level meanings. In this paper, we propose the Recursive Convolutional Bayesian Model (RCBM) to address both of these fundamental questions. The key idea behind our approach consists of constructing a deep-learning framework using specialized convolution operators that are designed to exploit the inherent heterogeneity of social dynamics. RCBM's runtime and convergence properties are guaranteed by formal analyses. Experimental results show that the proposed method outperforms the state-of-the-art approaches both in terms of solution quality and computational efficiency. Indeed, by applying the proposed method on two social network datasets, Twitter and Yelp, we are able to identify the compositional structures that can accurately characterize the complex social dynamics from these two social media. We further show that identifying these patterns can enable new applications such as anomaly detection and improved social dynamics forecasting. Finally, our analysis offers new insights on understanding and engineering social media dynamics, with direct applications to opinion spreading and online content promotion.

Multi-Scale Compositionality: Identifying the Compositional Structures of Social Dynamics Using Deep Learning

PubMed Central

Peng, Huan-Kai; Marculescu, Radu

2015-01-01

Objective Social media exhibit rich yet distinct temporal dynamics which cover a wide range of different scales. In order to study this complex dynamics, two fundamental questions revolve around (1) the signatures of social dynamics at different time scales, and (2) the way in which these signatures interact and form higher-level meanings. Method In this paper, we propose the Recursive Convolutional Bayesian Model (RCBM) to address both of these fundamental questions. The key idea behind our approach consists of constructing a deep-learning framework using specialized convolution operators that are designed to exploit the inherent heterogeneity of social dynamics. RCBM’s runtime and convergence properties are guaranteed by formal analyses. Results Experimental results show that the proposed method outperforms the state-of-the-art approaches both in terms of solution quality and computational efficiency. Indeed, by applying the proposed method on two social network datasets, Twitter and Yelp, we are able to identify the compositional structures that can accurately characterize the complex social dynamics from these two social media. We further show that identifying these patterns can enable new applications such as anomaly detection and improved social dynamics forecasting. Finally, our analysis offers new insights on understanding and engineering social media dynamics, with direct applications to opinion spreading and online content promotion. PMID:25830775

Photonic quantum state transfer between a cold atomic gas and a crystal.

PubMed

Maring, Nicolas; Farrera, Pau; Kutluer, Kutlu; Mazzera, Margherita; Heinze, Georg; de Riedmatten, Hugues

2017-11-22

Interfacing fundamentally different quantum systems is key to building future hybrid quantum networks. Such heterogeneous networks offer capabilities superior to those of their homogeneous counterparts, as they merge the individual advantages of disparate quantum nodes in a single network architecture. However, few investigations of optical hybrid interconnections have been carried out, owing to fundamental and technological challenges such as wavelength and bandwidth matching of the interfacing photons. Here we report optical quantum interconnection of two disparate matter quantum systems with photon storage capabilities. We show that a quantum state can be transferred faithfully between a cold atomic ensemble and a rare-earth-doped crystal by means of a single photon at 1,552  nanometre telecommunication wavelength, using cascaded quantum frequency conversion. We demonstrate that quantum correlations between a photon and a single collective spin excitation in the cold atomic ensemble can be transferred to the solid-state system. We also show that single-photon time-bin qubits generated in the cold atomic ensemble can be converted, stored and retrieved from the crystal with a conditional qubit fidelity of more than 85 per cent. Our results open up the prospect of optically connecting quantum nodes with different capabilities and represent an important step towards the realization of large-scale hybrid quantum networks.

Proposed experiment to test fundamentally binary theories

NASA Astrophysics Data System (ADS)

Kleinmann, Matthias; Vértesi, Tamás; Cabello, Adán

2017-09-01

Fundamentally binary theories are nonsignaling theories in which measurements of many outcomes are constructed by selecting from binary measurements. They constitute a sensible alternative to quantum theory and have never been directly falsified by any experiment. Here we show that fundamentally binary theories are experimentally testable with current technology. For that, we identify a feasible Bell-type experiment on pairs of entangled qutrits. In addition, we prove that, for any n , quantum n -ary correlations are not fundamentally (n -1 ) -ary. For that, we introduce a family of inequalities that hold for fundamentally (n -1 ) -ary theories but are violated by quantum n -ary correlations.

Mesoscopic model for filament orientation in growing actin networks: the role of obstacle geometry

NASA Astrophysics Data System (ADS)

Weichsel, Julian; Schwarz, Ulrich S.

2013-03-01

Propulsion by growing actin networks is a universal mechanism used in many different biological systems, ranging from the sheet-like lamellipodium of crawling animal cells to the actin comet tails induced by certain bacteria and viruses in order to move within their host cells. Although the core molecular machinery for actin network growth is well preserved in all of these cases, the geometry of the propelled obstacle varies considerably. During recent years, filament orientation distribution has emerged as an important observable characterizing the structure and dynamical state of the growing network. Here we derive several continuum equations for the orientation distribution of filaments growing behind stiff obstacles of various shapes and validate the predicted steady state orientation patterns by stochastic computer simulations based on discrete filaments. We use an ordinary differential equation approach to demonstrate that for flat obstacles of finite size, two fundamentally different orientation patterns peaked at either ±35° or +70°/0°/ - 70° exhibit mutually exclusive stability, in agreement with earlier results for flat obstacles of very large lateral extension. We calculate and validate phase diagrams as a function of model parameters and show how this approach can be extended to obstacles with piecewise straight contours. For curved obstacles, we arrive at a partial differential equation in the continuum limit, which again is in good agreement with the computer simulations. In all cases, we can identify the same two fundamentally different orientation patterns, but only within an appropriate reference frame, which is adjusted to the local orientation of the obstacle contour. Our results suggest that two fundamentally different network architectures compete with each other in growing actin networks, irrespective of obstacle geometry, and clarify how simulated and electron tomography data have to be analyzed for non-flat obstacle geometries.

Determining the importance of fundamental hearing aid attributes.

PubMed

Meister, Hartmut; Lausberg, Isabel; Kiessling, Juergen; Walger, Martin; von Wedel, Hasso

2002-07-01

To determine the importance of fundamental hearing aid attributes and to elicit measures of satisfaction and dissatisfaction. A prospective study based on a survey using a decompositional approach of preference measurement (conjoint analysis). Ear, nose, and throat university hospitals in Cologne and Giessen; various branches of hearing aid dispensers. A random sample of 175 experienced hearing aid users aged 20 to 91 years (mean age, 61 yr) recruited at two different sites. Relative importance of different hearing aid attributes, satisfaction and dissatisfaction with hearing aid attributes. Of the six fundamental hearing aid attributes assessed by the hearing aid users, the two features concerning speech perception attained the highest relative importance (25% speech in quiet, 27% speech in noise). The remaining four attributes (sound quality, handling, feedback, localization) had significantly lower values in a narrow range of 10 to 12%. Comparison of different subgroups of hearing aid wearers based on sociodemographic and user-specific data revealed a large interindividual scatter of the preferences for the attributes. A similar examination with 25 clinicians revealed overestimation of the importance of the attributes commonly associated with problems. Moreover, examination of satisfaction showed that speech in noise was the most frequent source of dissatisfaction (30% of all statements), whereas the subjects were satisfied with speech in quiet. The results emphasize the high importance of attributes related to speech perception. Speech discrimination in noise was the most important but also the most frequent source of negative statements. This attribute will be the outstanding parameter of future developments. Appropriate handling becomes an important factor for elderly subjects. However, because of the large interindividual scatter of data, the preferences of different hearing aid users were hardly predictable, giving evidence of multifactorial influences.

Thinking about Fantasy: Are Children Fundamentally Different Thinkers and Believers from Adults?

ERIC Educational Resources Information Center

Woolley, Jacqueline D.

1997-01-01

Reviews research on children's and adults' beliefs about fantasy and their tendency to engage in "magical thinking." Suggests that children are not fundamentally different from adults in their ability to distinguish fantasy from reality. Both entertain fantastical beliefs and engage in magical thinking. Offers suggestions regarding age…

Cross-Linguistic Differences in Bilinguals' Fundamental Frequency Ranges

ERIC Educational Resources Information Center

Ordin, Mikhail; Mennen, Ineke

2017-01-01

Purpose: We investigated cross-linguistic differences in fundamental frequency range (FFR) in Welsh-English bilingual speech. This is the first study that reports gender-specific behavior in switching FFRs across languages in bilingual speech. Method: FFR was conceptualized as a behavioral pattern using measures of span (range of fundamental…

Instructor Special Report: RIF (Reading Is FUNdamental)

ERIC Educational Resources Information Center

Instructor, 1976

1976-01-01

At a time when innovative programs of the sixties are quickly falling out of the picture, Reading Is FUNdamental, after ten years and five million free paperbacks, continues to expand and show results. (Editor)

Dynamics and asymptotics of correlations in a many-body localized system

NASA Astrophysics Data System (ADS)

Campbell, Steve; Power, Matthew J. M.; De Chiara, Gabriele

2017-08-01

We examine the dynamics of nearest-neighbor bipartite concurrence and total correlations in the spin-1/2 XXZ model with random fields. We show, starting from factorized random initial states, that the concurrence can suffer entanglement sudden death in the long time limit and therefore may not be a useful indicator of the properties of the system. In contrast, we show that the total correlations capture the dynamics more succinctly, and further reveal a fundamental difference in the dynamics governed by the ergodic versus many-body localized phases, with the latter exhibiting dynamical oscillations. Finally, we consider an initial state composed of several singlet pairs and show that by fixing the correlation properties, while the dynamics do not reveal noticeable differences between the phases, the long-time values of the correlation measures appear to indicate the critical region.

Study of the Variability of the Reflection Component in Seyfert 1 Galaxies: Connecting the Fe K Variability with the Compton Hump

NASA Astrophysics Data System (ADS)

Ponti, G.; Miniutti, G.; Malaguti, G.; Gallo, L.; Goldwurm, A.

2009-05-01

We present preliminary results of an ongoing project devoted to the study of the continuum and Fe K band variability in a sample of bright AGNs. These kind of studies may break the spectral degeneracy between the different absorption/emission models, allowing ``safe'' measurements of the disc and black hole properties from the broad line shapes. In fact, the Fe K band, alone, allows a first separation between the different components. Here we show the case of NGC 3783 which shows both a constant and a variable reflection component as well as strong ionized absorption. We show that a fundamental contribution will be given by Simbol-X that will allow to simultaneously measure not only the Fe K variability, but also the connected reflection hump variations.

Investigating the Effects of the Interaction Intensity in a Weak Measurement.

PubMed

Piacentini, Fabrizio; Avella, Alessio; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Brida, Giorgio; Degiovanni, Ivo Pietro; Genovese, Marco

2018-05-03

Measurements are crucial in quantum mechanics, for fundamental research as well as for applicative fields like quantum metrology, quantum-enhanced measurements and other quantum technologies. In the recent years, weak-interaction-based protocols like Weak Measurements and Protective Measurements have been experimentally realized, showing peculiar features leading to surprising advantages in several different applications. In this work we analyze the validity range for such measurement protocols, that is, how the interaction strength affects the weak value extraction, by measuring different polarization weak values on heralded single photons. We show that, even in the weak interaction regime, the coupling intensity limits the range of weak values achievable, setting a threshold on the signal amplification effect exploited in many weak measurement based experiments.

Improving the performance of computer color matching procedures.

PubMed

Karbasi, A; Moradian, S; Asiaban, S

2008-09-01

A premise was set up entailing the possibility of a synergistical combination of advantages of spectrophotometric and colorimetric matching procedures. Attempts were therefore made to test the performances of fifteen matching procedures, all based on the Kubelka-Munk theory, including two procedures utilizing the fundamental color stimulus R(FCS) of the spectral decomposition theory. Color differences CIE DeltaE(00) as well as concentration differences DeltaC(AVE) were used to theoretically rank the fifteen color matching procedures. Results showed that procedures based on R(FCS) were superior in accurately predicting colors and concentrations. Additionally, the metameric black component R(MB) of the decomposition theory also showed promise in predicting degrees of metamerism. This preliminary study, therefore, provides evidence for the premise of this investigation.

Relativities of fundamentality

NASA Astrophysics Data System (ADS)

McKenzie, Kerry

2017-08-01

S-dualities have been held to have radical implications for our metaphysics of fundamentality. In particular, it has been claimed that they make the fundamentality status of a physical object theory-relative in an important new way. But what physicists have had to say on the issue has not been clear or consistent, and in particular seems to be ambiguous between whether S-dualities demand an anti-realist interpretation of fundamentality talk or merely a revised realism. This paper is an attempt to bring some clarity to the matter. After showing that even antecedently familiar fundamentality claims are true only relative to a raft of metaphysical, physical, and mathematical assumptions, I argue that the relativity of fundamentality inherent in S-duality nevertheless represents something new, and that part of the reason for this is that it has both realist and anti-realist implications for fundamentality talk. I close by discussing the broader significance that S-dualities have for structuralist metaphysics and for fundamentality metaphysics more generally.

Survey of shock-wave structures of smooth-particle granular flows.

PubMed

Padgett, D A; Mazzoleni, A P; Faw, S D

2015-12-01

We show the effects of simulated supersonic granular flow made up of smooth particles passing over two prototypical bodies: a wedge and a disk. We describe a way of computationally identifying shock wave locations in granular flows and tabulate the shock wave locations for flow over wedges and disks. We quantify the shock structure in terms of oblique shock angle for wedge impediments and shock standoff distance for disk impediments. We vary granular flow parameters including upstream volume fraction, average upstream velocity, granular temperature, and the collision coefficient of restitution. Both wedges and disks have been used in the aerospace community as prototypical impediments to flowing air in order to investigate the fundamentally different shock structures emanating from sharp and blunt bodies, and we present these results in order to increase the understanding of the fundamental behavior of supersonic granular flow.

A subjective utilitarian theory of moral judgment.

PubMed

Cohen, Dale J; Ahn, Minwoo

2016-10-01

Current theories hypothesize that moral judgments are difficult because rational and emotional decision processes compete. We present a fundamentally different theory of moral judgment: the Subjective Utilitarian Theory of moral judgment. The Subjective Utilitarian Theory posits that people try to identify and save the competing item with the greatest "personal value." Moral judgments become difficult only when the competing items have similar personal values. In Experiment 1, we estimate the personal values of 104 items. In Experiments 2-5, we show that the distributional overlaps of the estimated personal values account for over 90% of the variance in reaction times (RTs) and response choices in a moral judgment task. Our model fundamentally restructures our understanding of moral judgments from a competition between decision processes to a competition between similarly valued items. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Toward Paradoxical Inconsistency in Electrostatics of Metallic Conductors

DTIC Science & Technology

Naturally, when dealing with fundamental problems, the V and V effort should include careful exploration and, if necessary, revision of the fundamentals...Current developments show a clear trend toward more serious efforts in validation and verification (V and V) of physical and engineering models...underlying the physics. With this understanding in mind, we review some fundamentals of the models of crystalline electric conductors and find a

Response of a hypersonic boundary layer to freestream pulse acoustic disturbance.

PubMed

Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing

2014-01-01

The response of hypersonic boundary layer over a blunt wedge to freestream pulse acoustic disturbance was investigated. The stability characteristics of boundary layer for freestream pulse wave and continuous wave were analyzed comparatively. Results show that freestream pulse disturbance changes the thermal conductivity characteristics of boundary layer. For pulse wave, the number of main disturbance clusters decreases and the frequency band narrows along streamwise. There are competition and disturbance energy transfer among different modes in boundary layer. The dominant mode of boundary layer has an inhibitory action on other modes. Under continuous wave, the disturbance modes are mainly distributed near fundamental and harmonic frequencies, while under pulse wave, the disturbance modes are widely distributed in different modes. For both pulse and continuous waves, most of disturbance modes slide into a lower-growth or decay state in downstream, which is tending towards stability. The amplitude of disturbance modes in boundary layer under continuous wave is considerably larger than pulse wave. The growth rate for the former is also considerably larger than the later the disturbance modes with higher growth are mainly distributed near fundamental and harmonic frequencies for the former, while the disturbance modes are widely distributed in different frequencies for the latter.

Response of a Hypersonic Boundary Layer to Freestream Pulse Acoustic Disturbance

PubMed Central

Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing

2014-01-01

The response of hypersonic boundary layer over a blunt wedge to freestream pulse acoustic disturbance was investigated. The stability characteristics of boundary layer for freestream pulse wave and continuous wave were analyzed comparatively. Results show that freestream pulse disturbance changes the thermal conductivity characteristics of boundary layer. For pulse wave, the number of main disturbance clusters decreases and the frequency band narrows along streamwise. There are competition and disturbance energy transfer among different modes in boundary layer. The dominant mode of boundary layer has an inhibitory action on other modes. Under continuous wave, the disturbance modes are mainly distributed near fundamental and harmonic frequencies, while under pulse wave, the disturbance modes are widely distributed in different modes. For both pulse and continuous waves, most of disturbance modes slide into a lower-growth or decay state in downstream, which is tending towards stability. The amplitude of disturbance modes in boundary layer under continuous wave is considerably larger than pulse wave. The growth rate for the former is also considerably larger than the later the disturbance modes with higher growth are mainly distributed near fundamental and harmonic frequencies for the former, while the disturbance modes are widely distributed in different frequencies for the latter. PMID:24737993

Predicting Achievable Fundamental Frequency Ranges in Vocalization Across Species

PubMed Central

Titze, Ingo; Riede, Tobias; Mau, Ted

2016-01-01

Vocal folds are used as sound sources in various species, but it is unknown how vocal fold morphologies are optimized for different acoustic objectives. Here we identify two main variables affecting range of vocal fold vibration frequency, namely vocal fold elongation and tissue fiber stress. A simple vibrating string model is used to predict fundamental frequency ranges across species of different vocal fold sizes. While average fundamental frequency is predominantly determined by vocal fold length (larynx size), range of fundamental frequency is facilitated by (1) laryngeal muscles that control elongation and by (2) nonlinearity in tissue fiber tension. One adaptation that would increase fundamental frequency range is greater freedom in joint rotation or gliding of two cartilages (thyroid and cricoid), so that vocal fold length change is maximized. Alternatively, tissue layers can develop to bear a disproportionate fiber tension (i.e., a ligament with high density collagen fibers), increasing the fundamental frequency range and thereby vocal versatility. The range of fundamental frequency across species is thus not simply one-dimensional, but can be conceptualized as the dependent variable in a multi-dimensional morphospace. In humans, this could allow for variations that could be clinically important for voice therapy and vocal fold repair. Alternative solutions could also have importance in vocal training for singing and other highly-skilled vocalizations. PMID:27309543

ERP Correlates of Pitch Error Detection in Complex Tone and Voice Auditory Feedback with Missing Fundamental

PubMed Central

Behroozmand, Roozbeh; Korzyukov, Oleg; Larson, Charles R.

2012-01-01

Previous studies have shown that the pitch of a sound is perceived in the absence of its fundamental frequency (F0), suggesting that a distinct mechanism may resolve pitch based on a pattern that exists between harmonic frequencies. The present study investigated whether such a mechanism is active during voice pitch control. ERPs were recorded in response to +200 cents pitch shifts in the auditory feedback of self-vocalizations and complex tones with and without the F0. The absence of the fundamental induced no difference in ERP latencies. However, a right-hemisphere difference was found in the N1 amplitudes with larger responses to complex tones that included the fundamental compared to when it was missing. The P1 and N1 latencies were shorter in the left hemisphere, and the N1 and P2 amplitudes were larger bilaterally for pitch shifts in voice and complex tones compared with pure tones. These findings suggest hemispheric differences in neural encoding of pitch in sounds with missing fundamental. Data from the present study suggest that the right cortical auditory areas, thought to be specialized for spectral processing, may utilize different mechanisms to resolve pitch in sounds with missing fundamental. The left hemisphere seems to perform faster processing to resolve pitch based on the rate of temporal variations in complex sounds compared with pure tones. These effects indicate that the differential neural processing of pitch in the left and right hemispheres may enable the audio-vocal system to detect temporal and spectral variations in the auditory feedback for vocal pitch control. PMID:22386045

Effects of amphipathic profile regularization on structural order and interaction with membrane models of two highly cationic branched peptides with β-sheet propensity.

PubMed

Serra, Ilaria; Casu, Mariano; Ceccarelli, Matteo; Gameiro, Paula; Rinaldi, Andrea C; Scorciapino, Mariano Andrea

2018-07-01

Antimicrobial peptides attracted increasing interest in last decades due to the rising concern of multi-drug resistant pathogens. Dendrimeric peptides are branched molecules with multiple copies of one peptide functional unit bound to the central core. Compared to linear analogues, they usually show improved activity and lower susceptibility to proteases. Knowledge of structure-function relationship is fundamental to tailor their properties. This work is focused on SB056, the smallest example of dendrimeric peptide, whose amino acid sequence is WKKIRVRLSA. Two copies are bound to the α- and ε- nitrogen of one lysine core. An 8-aminooctanamide was added at the C-terminus to improve membrane affinity. Its propensity for β-type structures is also interesting, since helical peptides were already thoroughly studied. Moreover, SB056 maintains activity at physiological osmolarity, a typical limitation of natural peptides. An optimized analogue with improved performance was designed, β-SB056, which differs only in the relative position of the first two residues (KWKIRVRLSA). This produced remarkable differences. Structure order and aggregation behavior were characterized by using complementary techniques and membrane models with different negative charge. Infrared spectroscopy showed different propensity for ordered β-sheets. Lipid monolayers' surface pressure was measured to estimate the area/peptide and the ability to perturb lipid packing. Fluorescence spectroscopy was applied to compare peptide insertion into the lipid bilayer. Such small change in primary structure produced fundamental differences in their aggregation behavior. A regular amphipathic peptide's primary structure was responsible for ordered β-sheets in a charge independent fashion, in contrast to unordered aggregates formed by the former analogue. Copyright © 2018 Elsevier Inc. All rights reserved.

Testing Our Fundamental Assumptions

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-06-01

Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these fundamental assumptions.A recent focus set in the Astrophysical Journal Letters, titled Focus on Exploring Fundamental Physics with Extragalactic Transients, consists of multiple published studies doing just that.Testing General RelativitySeveral of the articles focus on the 4th point above. By assuming that the delay in photon arrival times is only due to the gravitational potential of the Milky Way, these studies set constraints on the deviation of our galaxys gravitational potential from what GR would predict. The study by He Gao et al. uses the different photon arrival times from gamma-ray bursts to set constraints at eVGeV energies, and the study by Jun-Jie Wei et al. complements this by setting constraints at keV-TeV energies using photons from high-energy blazar emission.Photons or neutrinos from different extragalactic transients each set different upper limits on delta gamma, the post-Newtonian parameter, vs. particle energy or frequency. This is a test of Einsteins equivalence principle: if the principle is correct, delta gamma would be exactly zero, meaning that photons of different energies move at the same velocity through a vacuum. [Tingay Kaplan 2016]S.J. Tingay D.L. Kaplan make the case that measuring the time delay of photons from fast radio bursts (FRBs; transient radio pulses that last only a few milliseconds) will provide even tighter constraints if we are able to accurately determine distances to these FRBs.And Adi Musser argues that the large-scale structure of the universe plays an even greater role than the Milky Way gravitational potential, allowing for even stricter testing of Einsteins equivalence principle.The ever-narrower constraints from these studies all support GR as a correct set of rules through which to interpret our universe.Other Tests of Fundamental PhysicsIn addition to the above tests, Xue-Feng Wu et al. show that FRBs can be used to provide severe constraints on the rest mass of the photon, and S. Croft et al. even touches on what we might learn from transients using multi-messenger astrophysics (astrophysics involving observations of particles besides photons, such as neutrinos or gravitational waves).In general, extragalactic transients provide a rich prospect for better understanding the laws that govern the universe. Check out the entire focus set below to learn more about the tests of fundamental physics that can be done with observations of extragalactic transients!CitationFocus Set: Focus on Exploring Fundamental Physics With Extragalactic TransientsHe Gao et al. 2015 ApJ 810 121. doi:10.1088/0004-637X/810/2/121Jun-Jie Wei et al. 2016 ApJ 818 L2. doi:10.3847/2041-8205/818/1/L2S. Croft et al. 2016 ApJ 820 L24. doi:10.3847/2041-8205/820/2/L24S. J. Tingay and D. L. Kaplan 2016 ApJ 820 L31. doi:10.3847/2041-8205/820/2/L31Adi Nusser 2016 ApJ 821 L2. doi:10.3847/2041-8205/821/1/L2Xue-Feng Wu et al. 2016 ApJ 822 L15. doi:10.3847/2041-8205/822/1/L15

Students' Perceptions of Dynamics Concept Pairs and Correlation with Their Problem-Solving Performance

ERIC Educational Resources Information Center

Fang, Ning

2012-01-01

A concept pair is a pair of concepts that are fundamentally different but closely related. To develop a solid conceptual understanding in dynamics (a foundational engineering science course) and physics, students must understand the fundamental difference and relationship between two concepts that are included in each concept pair. However, all…

Predicting fundamental frequency from mel-frequency cepstral coefficients to enable speech reconstruction.

PubMed

Shao, Xu; Milner, Ben

2005-08-01

This work proposes a method to reconstruct an acoustic speech signal solely from a stream of mel-frequency cepstral coefficients (MFCCs) as may be encountered in a distributed speech recognition (DSR) system. Previous methods for speech reconstruction have required, in addition to the MFCC vectors, fundamental frequency and voicing components. In this work the voicing classification and fundamental frequency are predicted from the MFCC vectors themselves using two maximum a posteriori (MAP) methods. The first method enables fundamental frequency prediction by modeling the joint density of MFCCs and fundamental frequency using a single Gaussian mixture model (GMM). The second scheme uses a set of hidden Markov models (HMMs) to link together a set of state-dependent GMMs, which enables a more localized modeling of the joint density of MFCCs and fundamental frequency. Experimental results on speaker-independent male and female speech show that accurate voicing classification and fundamental frequency prediction is attained when compared to hand-corrected reference fundamental frequency measurements. The use of the predicted fundamental frequency and voicing for speech reconstruction is shown to give very similar speech quality to that obtained using the reference fundamental frequency and voicing.

Difference between the vocalizations of two sister species of pigeons explained in dynamical terms.

PubMed

Alonso, R Gogui; Kopuchian, Cecilia; Amador, Ana; Suarez, Maria de Los Angeles; Tubaro, Pablo L; Mindlin, Gabriel B

2016-05-01

Vocal communication is an unique example, where the nonlinear nature of the periphery can give rise to complex sounds even when driven by simple neural instructions. In this work we studied the case of two close-related bird species, Patagioenas maculosa and Patagioenas picazuro, whose vocalizations differ only in the timbre. The temporal modulation of the fundamental frequency is similar in both cases, differing only in the existence of sidebands around the fundamental frequency in the P. maculosa. We tested the hypothesis that the qualitative difference between these vocalizations lies in the nonlinear nature of the syrinx. In particular, we propose that the roughness of maculosa's vocalizations is due to an asymmetry between the right and left vibratory membranes, whose nonlinear dynamics generate the sound. To test the hypothesis, we generated a biomechanical model for vocal production with an asymmetric parameter Q with which we can control the level of asymmetry between these membranes. Using this model we generated synthetic vocalizations with the principal acoustic features of both species. In addition, we confirmed the anatomical predictions by making post mortem inspection of the syrinxes, showing that the species with tonal song (picazuro) has a more symmetrical pair of membranes compared to maculosa.

Difference between the vocalizations of two sister species of pigeons explained in dynamical terms

PubMed Central

Alonso, R. Gogui; Kopuchian, Cecilia; Amador, Ana; de los Angeles Suarez, Maria; Tubaro, Pablo L.; Mindlin, Gabriel B.

2016-01-01

Vocal communication is a unique example where the nonlinear nature of the periphery can give rise to complex sounds even when driven by simple neural instructions. In this work we studied the case of two close-related bird species, Patagioenas maculosa and Patagioenas picazuro, whose vocalizations differ only in the timbre. The temporal modulation of the fundamental frequency is similar in both cases, differing only in the existence of sidebands around the fundamental frequency in the Patagioenas maculosa. We tested the hypothesis that the qualitative difference between these vocalizations lies in the nonlinear nature of the syrinx. In particular, we propose that the roughness of maculosa's vocalizations is due to an asymmetry between the right and left vibratory membranes, whose nonlinear dynamics generate the sound. To test the hypothesis, we generated a biomechanical model for vocal production with an asymmetric parameter Q with which we can control the level of asymmetry between these membranes. Using this model we generated synthetic vocalizations with the principal acoustic features of both species. In addition, we confirmed the anatomical predictions by making post-mortem inspection of the syrinxes, showing that the species with tonal song (picazuro) has a more symmetrical pair of membranes compared to maculosa. PMID:27033354

Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity.

PubMed

Koyluoglu, Onur Ozan; Pertzov, Yoni; Manohar, Sanjay; Husain, Masud; Fiete, Ila R

2017-09-07

It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain.

Detecting gravitational decoherence with clocks: Limits on temporal resolution from a classical-channel model of gravity

NASA Astrophysics Data System (ADS)

Khosla, Kiran E.; Altamirano, Natacha

2017-05-01

The notion of time is given a different footing in quantum mechanics and general relativity, treated as a parameter in the former and being an observer-dependent property in the latter. From an operational point of view time is simply the correlation between a system and a clock, where an idealized clock can be modeled as a two-level system. We investigate the dynamics of clocks interacting gravitationally by treating the gravitational interaction as a classical information channel. This model, known as the classical-channel gravity (CCG), postulates that gravity is mediated by a fundamentally classical force carrier and is therefore unable to entangle particles gravitationally. In particular, we focus on the decoherence rates and temporal resolution of arrays of N clocks, showing how the minimum dephasing rate scales with N , and the spatial configuration. Furthermore, we consider the gravitational redshift between a clock and a massive particle and show that a classical-channel model of gravity predicts a finite-dephasing rate from the nonlocal interaction. In our model we obtain a fundamental limitation in time accuracy that is intrinsic to each clock.

Fundamental bound on the persistence and capacity of short-term memory stored as graded persistent activity

PubMed Central

Pertzov, Yoni; Manohar, Sanjay; Husain, Masud; Fiete, Ila R

2017-01-01

It is widely believed that persistent neural activity underlies short-term memory. Yet, as we show, the degradation of information stored directly in such networks behaves differently from human short-term memory performance. We build a more general framework where memory is viewed as a problem of passing information through noisy channels whose degradation characteristics resemble those of persistent activity networks. If the brain first encoded the information appropriately before passing the information into such networks, the information can be stored substantially more faithfully. Within this framework, we derive a fundamental lower-bound on recall precision, which declines with storage duration and number of stored items. We show that human performance, though inconsistent with models involving direct (uncoded) storage in persistent activity networks, can be well-fit by the theoretical bound. This finding is consistent with the view that if the brain stores information in patterns of persistent activity, it might use codes that minimize the effects of noise, motivating the search for such codes in the brain. PMID:28879851

Temporal Changes in Education Gradients of ‘Preventable’ Mortality: A Test of Fundamental Cause Theory

PubMed Central

Masters, Ryan K.; Link, Bruce G.; Phelan, Jo C.

2015-01-01

Fundamental cause theory explains persisting associations between socioeconomic status and mortality in terms of personal resources such as knowledge, money, power, prestige, and social connections, as well as disparate social contexts related to these resources. We review evidence concerning fundamental cause theory and test three central claims using the National Health Interview Survey Linked Mortality Files 1986-2004. We then examine cohort-based variation in the associations between a fundamental social cause of disease, educational attainment, and mortality rates from heart disease, other “preventable” causes of death, and less preventable causes of death. We further explore race/ethnic and gender variation in these associations. Overall, findings are consistent with nearly all features of fundamental cause theory. Results show, first, larger education gradients in mortality risk for causes of death that are under greater human control than for less preventable causes of death, and, second, that these gradients grew more rapidly across successive cohorts than gradients for less preventable causes. Results also show that relative sizes and cohort-based changes in the education gradients vary substantially by race/ethnicity and gender. PMID:25556675

The Computational Complexity of Valuation and Motivational Forces in Decision-Making Processes

PubMed Central

Schultheiss, Nathan W.; Carter, Evan C.

2015-01-01

The concept of value is fundamental to most theories of motivation and decision making. However, value has to be measured experimentally. Different methods of measuring value produce incompatible valuation hierarchies. Taking the agent’s perspective (rather than the experimenter’s), we interpret the different valuation measurement methods as accessing different decision-making systems and show how these different systems depend on different information processing algorithms. This identifies the translation from these multiple decision-making systems into a single action taken by a given agent as one of the most important open questions in decision making today. We conclude by looking at how these different valuation measures accessing different decision-making systems can be used to understand and treat decision dysfunction such as in addiction. PMID:25981912

Cost, Time, and Risk Assessment of Different Wave Energy Converter Technology Development Trajectories: Preprint

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

Weber, Jochem W; Laird, Daniel; Costello, Ronan

This paper presents a comparative assessment of three fundamentally different wave energy converter technology development trajectories. The three technology development trajectories are expressed and visualised as a function of technology readiness levels and technology performance levels. The assessment shows that development trajectories that initially prioritize technology readiness over technology performance are likely to require twice the development time, consume a threefold of the development cost, and are prone to a risk of technical or commercial failure of one order of magnitude higher than those development trajectories that initially prioritize technology performance over technology readiness.

Observations on the interaction of nanomaterials with bacteria

NASA Astrophysics Data System (ADS)

Raja, P. M.; Ajayan, P. M.; Nalamasu, O.; Sharma, A.

2006-05-01

Large scale commercial manufacturing of nanomaterials raises the important issue of their environmental fate. With increased production (estimated to be in million gallon range) the nanomaterial interactions with environmental microbial ecology would be significant. However, there are scant studies that have addressed this concern. It is therefore essential to experimentally determine some fundamental parameters to ascertain any environmental stresses related to microbiological interactions of nanomaterials. There are concerns that such an interaction may be similar to the biogeochemical interactions of asbestos fibers, which continues to be an alarming environmental issue. Carbon nanotubes (CNTs) are newly emerging nanomaterials, with a wide range of potential electronic and medical applications. Though CNTs are dimensionally similar to the mineral fibers, they differ morphologically, and can possess different surface chemistries, capable of complex and varied biological interactions within the environment. In this study, we present experimental data that show discernible effects on microbial morphology, biofilm formation, substrate consumption rates and growth of Escherichia coli in the presence of carbon nanotubes with the aim of developing a fundamental understanding of the environmental implications of CNT-microbial interactions.

Origin of long-lived oscillations in 2D-spectra of a quantum vibronic model: Electronic versus vibrational coherence

NASA Astrophysics Data System (ADS)

Plenio, M. B.; Almeida, J.; Huelga, S. F.

2013-12-01

We demonstrate that the coupling of excitonic and vibrational motion in biological complexes can provide mechanisms to explain the long-lived oscillations that have been obtained in nonlinear spectroscopic signals of different photosynthetic pigment protein complexes and we discuss the contributions of excitonic versus purely vibrational components to these oscillatory features. Considering a dimer model coupled to a structured spectral density we exemplify the fundamental aspects of the electron-phonon dynamics, and by analyzing separately the different contributions to the nonlinear signal, we show that for realistic parameter regimes purely electronic coherence is of the same order as purely vibrational coherence in the electronic ground state. Moreover, we demonstrate how the latter relies upon the excitonic interaction to manifest. These results link recently proposed microscopic, non-equilibrium mechanisms to support long lived coherence at ambient temperatures with actual experimental observations of oscillatory behaviour using 2D photon echo techniques to corroborate the fundamental importance of the interplay of electronic and vibrational degrees of freedom in the dynamics of light harvesting aggregates.

A high definition Mueller polarimetric endoscope for tissue characterisation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Qi, Ji; Elson, Daniel

2016-03-01

The mechanism of most medical endoscopes is based on the interaction between light and biological tissue, inclusive of absorption, elastic scattering and fluorescence. In essence, the metrics of those interactions are obtained from the fundamental properties of light as an electro-magnetic waves, namely, the radiation intensity and wavelength. As another fundamental property of light, polarisation can not only reveal tissue scattering and absorption information from a different perspective, but is also able to provide a fresh insight into directional tissue birefringence properties induced by birefringent compositions and anisotropic fibrous structures, such as collagen, elastin, muscle fibre, etc at the same time. Here we demonstrate a low cost high definition Muller polarimetric endoscope with minimal alteration of a rigid endoscope. By imaging birefringent tissue mimicking phantoms and a porcine bladder, we show that this novel endoscopic imaging modality is able to provide different information of interest from unpolarised endoscopic imaging, including linear depolarization, circular depolarization, birefringence, optic axis orientation and dichroism. This endoscope can potentially be employed for better tissue visualisation and benefit endoscopic investigations and intra-operative guidance.

Volumetric data analysis using Morse-Smale complexes

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

Natarajan, V; Pascucci, V

2005-10-13

The 3D Morse-Smale complex is a fundamental topological construct that partitions the domain of a real-valued function into regions having uniform gradient flow behavior. In this paper, we consider the construction and selective presentation of cells of the Morse-Smale complex and their use in the analysis and visualization of scientific datasets. We take advantage of the fact that cells of different dimension often characterize different types of features present in the data. For example, critical points pinpoint changes in topology by showing where components of the level sets are created, destroyed or modified in genus. Edges of the Morse-Smale complexmore » extract filament-like features that are not explicitly modeled in the original data. Interactive selection and rendering of portions of the Morse-Smale complex introduces fundamental data management challenges due to the unstructured nature of the complex even for structured inputs. We describe a data structure that stores the Morse-Smale complex and allows efficient selective traversal of regions of interest. Finally, we illustrate the practical use of this approach by applying it to cryo-electron microscopy data of protein molecules.« less

Removal of Verrucaria nigrescens from Carrara marble artefacts using Nd:YAG lasers: comparison among different pulse durations and wavelengths

NASA Astrophysics Data System (ADS)

Osticioli, I.; Mascalchi, M.; Pinna, D.; Siano, S.

2015-03-01

The periodical removal of biodeteriogens is a fundamental need for the preservation of outdoor stone cultural heritage, which is stimulating significant efforts toward the development of low-impact conservation strategies. In the present work, the potential of laser removal of Verrucaria nigrescens Pers. from Carrara marble and the evaluation of the associated biocide effect on the organism residues embedded in the surface texture and through the outer porosities of the stone substrate were investigated. The fundamental wavelength of Nd:YAG laser (1,064 nm), commonly used in stone cleaning, and its second harmonic (532 nm) were comparatively tested. The phenomenology of laser treatments carried out in different irradiation conditions was characterized using optical, epifluorescence, and electron microscopes along with chlorophyll fluorescence with pulsed amplitude-modulated imaging. The results achieved show that 532 nm can provide significant advantages with respect to 1,064 nm. The potential of the latter against the biodeteriogens appears rather limited because of the low optical absorption, whereas the former can allow effective and practicable laser treatments, which disclose a significant application perspective.

Audio-vocal responses of vocal fundamental frequency and formant during sustained vowel vocalizations in different noises.

PubMed

Lee, Shao-Hsuan; Hsiao, Tzu-Yu; Lee, Guo-She

2015-06-01

Sustained vocalizations of vowels [a], [i], and syllable [mə] were collected in twenty normal-hearing individuals. On vocalizations, five conditions of different audio-vocal feedback were introduced separately to the speakers including no masking, wearing supra-aural headphones only, speech-noise masking, high-pass noise masking, and broad-band-noise masking. Power spectral analysis of vocal fundamental frequency (F0) was used to evaluate the modulations of F0 and linear-predictive-coding was used to acquire first two formants. The results showed that while the formant frequencies were not significantly shifted, low-frequency modulations (<3 Hz) of F0 significantly increased with reduced audio-vocal feedback across speech sounds and were significantly correlated with auditory awareness of speakers' own voices. For sustained speech production, the motor speech controls on F0 may depend on a feedback mechanism while articulation should rely more on a feedforward mechanism. Power spectral analysis of F0 might be applied to evaluate audio-vocal control for various hearing and neurological disorders in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

Fundamental differences in promoter CpG island DNA hypermethylation between human cancer and genetically engineered mouse models of cancer.

PubMed

Diede, Scott J; Yao, Zizhen; Keyes, C Chip; Tyler, Ashlee E; Dey, Joyoti; Hackett, Christopher S; Elsaesser, Katrina; Kemp, Christopher J; Neiman, Paul E; Weiss, William A; Olson, James M; Tapscott, Stephen J

2013-12-01

Genetic and epigenetic alterations are essential for the initiation and progression of human cancer. We previously reported that primary human medulloblastomas showed extensive cancer-specific CpG island DNA hypermethylation in critical developmental pathways. To determine whether genetically engineered mouse models (GEMMs) of medulloblastoma have comparable epigenetic changes, we assessed genome-wide DNA methylation in three mouse models of medulloblastoma. In contrast to human samples, very few loci with cancer-specific DNA hypermethylation were detected, and in almost all cases the degree of methylation was relatively modest compared with the dense hypermethylation in the human cancers. To determine if this finding was common to other GEMMs, we examined a Burkitt lymphoma and breast cancer model and did not detect promoter CpG island DNA hypermethylation, suggesting that human cancers and at least some GEMMs are fundamentally different with respect to this epigenetic modification. These findings provide an opportunity to both better understand the mechanism of aberrant DNA methylation in human cancer and construct better GEMMs to serve as preclinical platforms for therapy development.

The representation of multiplication and division facts in memory.

PubMed

De Brauwer, Jolien; Fias, Wim

2011-01-01

Recently, using a training paradigm, Campbell and Agnew (2009) observed cross-operation response time savings with nonidentical elements (e.g., practice 3 + 2, test 5 - 2) for addition and subtraction, showing that a single memory representation underlies addition and subtraction performance. Evidence for cross-operation savings between multiplication and division have been described frequently (e.g., Campbell, Fuchs-Lacelle, & Phenix, 2006) but they have always been attributed to a mediation strategy (reformulating a division problem as a multiplication problem, e.g., Campbell et al., 2006). Campbell and Agnew (2009) therefore concluded that there exists a fundamental difference between addition and subtraction on the one hand and multiplication and division on the other hand. However, our results suggest that retrieval savings between inverse multiplication and division problems can be observed. Even for small problems (solved by direct retrieval) practicing a division problem facilitated the corresponding multiplication problem and vice versa. These findings indicate that shared memory representations underlie multiplication and division retrieval. Hence, memory and learning processes do not seem to differ fundamentally between addition-subtraction and multiplication-division.

Evidence for the Fundamental Difference Hypothesis or Not?: Island Constraints Revisited

ERIC Educational Resources Information Center

Belikova, Alyona; White, Lydia

2009-01-01

This article examines how changes in linguistic theory affect the debate between the fundamental difference hypothesis and the access-to-Universal Grammar (UG) approach to SLA. With a focus on subjacency (Chomsky, 1973), a principle of UG that places constraints on "wh"-movement and that has frequently been taken as a test case for verifying…

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... fundamentally different factors. (a) Definition. The term Requester means an Industrial User or a POTW or other... Pretreatment Standards, making them either more or less stringent, as they apply to a certain Industrial User within an industrial category or subcategory. This will only be done if data specific to that Industrial...

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.

Code of Federal Regulations, 2013 CFR

2013-07-01

... fundamentally different factors. (a) Definition. The term Requester means an Industrial User or a POTW or other... Pretreatment Standards, making them either more or less stringent, as they apply to a certain Industrial User within an industrial category or subcategory. This will only be done if data specific to that Industrial...

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... fundamentally different factors. (a) Definition. The term Requester means an Industrial User or a POTW or other... Pretreatment Standards, making them either more or less stringent, as they apply to a certain Industrial User within an industrial category or subcategory. This will only be done if data specific to that Industrial...

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... fundamentally different factors. (a) Definition. The term Requester means an Industrial User or a POTW or other... Pretreatment Standards, making them either more or less stringent, as they apply to a certain Industrial User within an industrial category or subcategory. This will only be done if data specific to that Industrial...

The Particle Adventure | What is fundamental? | Fundamental

Science.gov Websites

Quiz - What particles are made of The four interactions How does matter interact? The unseen effect Half life Missing mass Particle decay mediators Virtual particles Different interactions Annihilations

Correlates of homophobia, transphobia, and internalized homophobia in gay or lesbian and heterosexual samples.

PubMed

Warriner, Katrina; Nagoshi, Craig T; Nagoshi, Julie L

2013-01-01

This research assessed the correlates of homophobia and transphobia in heterosexual and homosexual individuals, based on a theory of different sources of perceived symbolic threat to social status. Compared to 310 heterosexual college students, a sample of 30 gay male and 30 lesbian college students scored lower on homophobia, transphobia, and religious fundamentalism. Mean gender differences were smaller for gay men and lesbians for homophobia, aggressiveness, benevolent sexism, masculinity, and femininity. Fundamentalism, right-wing authoritarianism, and hostile and benevolent sexism were correlated only with homophobia in lesbians, whereas fundamentalism and authoritarianism were correlated only with transphobia in gay men. Correlates of internalized homophobia were different than those found for homophobia and transphobia, which was discussed in terms of gender differences in threats to status based on sexual orientation versus gender identity.

How to choose methods for lake greenhouse gas flux measurements?

NASA Astrophysics Data System (ADS)

Bastviken, David

2017-04-01

Lake greenhouse gas (GHG) fluxes are increasingly recognized as important for lake ecosystems as well as for large scale carbon and GHG budgets. However, many of our flux estimates are uncertain and it can be discussed if the presently available data is representative for the systems studied or not. Data are also very limited for some important flux pathways. Hence, many ongoing efforts try to better constrain fluxes and understand flux regulation. A fundamental challenge towards improved knowledge and when starting new studies is what methods to choose. A variety of approaches to measure aquatic GHG exchange is used and data from different methods and methodological approaches have often been treated as equally valid to create large datasets for extrapolations and syntheses. However, data from different approaches may cover different flux pathways or spatio-temporal domains and are thus not always comparable. Method inter-comparisons and critical method evaluations addressing these issues are rare. Emerging efforts to organize systematic multi-lake monitoring networks for GHG fluxes leads to method choices that may set the foundation for decades of data generation and therefore require fundamental evaluation of different approaches. The method choices do not only regard the equipment but also for example consideration of overall measurement design and field approaches, relevant spatial and temporal resolution for different flux components, and accessory variables to measure. In addition, consideration of how to design monitoring approaches being affordable, suitable for widespread (global) use, and comparable across regions is needed. Inspired by discussions with Prof. Dr. Cristian Blodau during the EGU General Assembly 2016, this presentation aims to (1) illustrate fundamental pros and cons for a number of common methods, (2) show how common methodological approaches originally adapted for other environments can be improved for lake flux measurements, (3) suggest how consideration of spatio-temporal dimensions of flux variability can lead to more optimized approaches, and (4) highlight possibilities of efficient ways forward including low-cost technologies that has potential for world-wide use.

Socioeconomic determinants of childhood overweight and obesity in China: the long arm of institutional power

PubMed Central

Fu, Qiang; George, Linda K.

2018-01-01

Abstract Previous studies have widely reported that the association between socioeconomic status (SES) and childhood overweight and obesity in China is significant and positive, which lends little support to the fundamental-cause perspective. Using multiple waves (1997, 2000, 2004 and 2006) of the China Health and Nutrition Survey (CHNS) (N = 2,556, 2,063, 1,431 and 1,242, respectively) and continuous BMI cut-points obtained from a polynomial method, (mixed-effect) logistic regression analyses show that parental state-sector employment, an important, yet overlooked, indicator of political power during the market transformation has changed from a risk factor for childhood overweight/obesity in 1997 to a protective factor for childhood overweight/obesity in 2006. Results from quantile regression analyses generate the same conclusions and demonstrate that the protective effect of parental state sector employment at high percentiles of BMI is robust under different estimation strategies. By bridging the fundamental causes perspective and theories of market transformation, this research not only documents the effect of political power on childhood overweight/obesity but also calls for the use of multifaceted, culturally-relevant stratification measures in testing the fundamental cause perspective across time and space. PMID:26178452

Nonlinear ultrasonic imaging with X wave

NASA Astrophysics Data System (ADS)

Du, Hongwei; Lu, Wei; Feng, Huanqing

2009-10-01

X wave has a large depth of field and may have important application in ultrasonic imaging to provide high frame rate (HFR). However, the HFR system suffers from lower spatial resolution. In this paper, a study of nonlinear imaging with X wave is presented to improve the resolution. A theoretical description of realizable nonlinear X wave is reported. The nonlinear field is simulated by solving the KZK nonlinear wave equation with a time-domain difference method. The results show that the second harmonic field of X wave has narrower mainlobe and lower sidelobes than the fundamental field. In order to evaluate the imaging effect with X wave, an imaging model involving numerical calculation of the KZK equation, Rayleigh-Sommerfeld integral, band-pass filtering and envelope detection is constructed to obtain 2D fundamental and second harmonic images of scatters in tissue-like medium. The results indicate that if X wave is used, the harmonic image has higher spatial resolution throughout the entire imaging region than the fundamental image, but higher sidelobes occur as compared to conventional focus imaging. A HFR imaging method with higher spatial resolution is thus feasible provided an apodization method is used to suppress sidelobes.

Auditory biological marker of concussion in children

PubMed Central

Kraus, Nina; Thompson, Elaine C.; Krizman, Jennifer; Cook, Katherine; White-Schwoch, Travis; LaBella, Cynthia R.

2016-01-01

Concussions carry devastating potential for cognitive, neurologic, and socio-emotional disease, but no objective test reliably identifies a concussion and its severity. A variety of neurological insults compromise sound processing, particularly in complex listening environments that place high demands on brain processing. The frequency-following response captures the high computational demands of sound processing with extreme granularity and reliably reveals individual differences. We hypothesize that concussions disrupt these auditory processes, and that the frequency-following response indicates concussion occurrence and severity. Specifically, we hypothesize that concussions disrupt the processing of the fundamental frequency, a key acoustic cue for identifying and tracking sounds and talkers, and, consequently, understanding speech in noise. Here we show that children who sustained a concussion exhibit a signature neural profile. They have worse representation of the fundamental frequency, and smaller and more sluggish neural responses. Neurophysiological responses to the fundamental frequency partially recover to control levels as concussion symptoms abate, suggesting a gain in biological processing following partial recovery. Neural processing of sound correctly identifies 90% of concussion cases and clears 95% of control cases, suggesting this approach has practical potential as a scalable biological marker for sports-related concussion and other types of mild traumatic brain injuries. PMID:28005070

An Interpolation Method for Obtaining Thermodynamic Properties Near Saturated Liquid and Saturated Vapor Lines

NASA Technical Reports Server (NTRS)

Nguyen, Huy H.; Martin, Michael A.

2003-01-01

The availability and proper utilization of fluid properties is of fundamental importance in the process of mathematical modeling of propulsion systems. Real fluid properties provide the bridge between the realm of pure analytiis and empirical reality. The two most common approaches used to formulate thermodynamic properties of pure substances are fundamental (or characteristic) equations of state (Helmholtz and Gibbs functions) and a piecemeal approach that is described, for example, in Adebiyi and Russell (1992). This paper neither presents a different method to formulate thermodynamic properties of pure substances nor validates the aforementioned approaches. Rather its purpose is to present a method to be used to facilitate the accurate interpretation of fluid thermodynamic property data generated by existing property packages. There are two parts to this paper. The first part of the paper shows how efficient and usable property tables were generated, with the minimum number of data points, using an aerospace industry standard property package (based on fundamental equations of state approach). The second part describes an innovative interpolation technique that has been developed to properly obtain thermodynamic properties near the saturated liquid and saturated vapor lines.

From the Kohn-Sham band gap to the fundamental gap in solids. An integer electron approach.

PubMed

Baerends, E J

2017-06-21

It is often stated that the Kohn-Sham occupied-unoccupied gap in both molecules and solids is "wrong". We argue that this is not a correct statement. The KS theory does not allow to interpret the exact KS HOMO-LUMO gap as the fundamental gap (difference (I - A) of electron affinity (A) and ionization energy (I), twice the chemical hardness), from which it indeed differs, strongly in molecules and moderately in solids. The exact Kohn-Sham HOMO-LUMO gap in molecules is much below the fundamental gap and very close to the much smaller optical gap (first excitation energy), and LDA/GGA yield very similar gaps. In solids the situation is different: the excitation energy to delocalized excited states and the fundamental gap (I - A) are very similar, not so disparate as in molecules. Again the Kohn-Sham and LDA/GGA band gaps do not represent (I - A) but are significantly smaller. However, the special properties of an extended system like a solid make it very easy to calculate the fundamental gap from the ground state (neutral system) band structure calculations entirely within a density functional framework. The correction Δ from the KS gap to the fundamental gap originates from the response part v resp of the exchange-correlation potential and can be calculated very simply using an approximation to v resp . This affords a calculation of the fundamental gap at the same level of accuracy as other properties of crystals at little extra cost beyond the ground state bandstructure calculation. The method is based on integer electron systems, fractional electron systems (an ensemble of N- and (N + 1)-electron systems) and the derivative discontinuity are not invoked.

Photoacoustic spectroscopy of man infecting protozoans

NASA Astrophysics Data System (ADS)

Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.

1998-08-01

In this paper the fundamentals of photothermal spectroscopy are presented, special emphasis is done in the obtention of the optical absorption spectra. It is shown that this spectroscopy can be used successfully for the monitoring of protozoans that could infect the human. The usefulness of the technique is illustrated in the special case of Leishmania, where it is possible to find that the stage when the protozoan infect vertebrate cells show important differences in relation to the protozoans infecting insects.

Study of Transition Mechanism in a Wake Behind an Airfoil with a Small Angle of Attack by Using a Towing Wind Tunnel

NASA Astrophysics Data System (ADS)

Morita, Toshiyuki; Maekawa, Hiroshi

This paper describes an experimental investigation of the transitional mechanism of a wake generated behind a thin airfoil with a small angle of attack in a towing wind tunnel. A linear stability analysis shows that the wake is characterized by a region of absolute instability in the near wake (x=30mm) and one of convective instability further downstream. When the airfoil starts to run in the tunnel, boundary layers develop on the upper/lower airfoil surfaces with different thickness. Since the asymmetric wake is generated, starting vortices of a single row are observed first in the wake, which is different from the Karman vortex street. The experimental results show that time-harmonic fluctuations of the starting vortex sustain in the natural transition process due to a self sustained resonance in the absolutely unstable region behind the trailing edge. The wake profile in the saturation steady state yields the vortex street structure, where the fluctuation frequency defined as the fundamental unstable mode is found in the final saturation steady state. The growth of the fundamental unstable mode in the convectively unstable region suppresses the high frequency fluctuations associated with the starting vortex generation. On the other hand, low-frequency fluctuations in the quasi-steady state sustaining in the saturation state grow gradually during the vortex street formation, which lead to the vortex deformation downstream.

Embedding fundamental care in the pre-registration nursing curriculum: Results from a pilot study.

PubMed

Feo, Rebecca; Donnelly, Frank; Frensham, Lauren; Conroy, Tiffany; Kitson, Alison

2018-05-01

International evidence suggests nursing is not providing fundamental care consistently or adequately, resulting in poor outcomes for patients and healthcare systems. One possible reason for this inadequate care delivery is nursing education, with fundamental care often implicit or invisible in nursing curricula. To understand how best to teach fundamental care to pre-registration (pre-licensure) students, we developed and piloted a six-week intervention that incorporated into the first-year curriculum a more explicit focus on fundamental care. A conceptual fundamental care framework was used to guide students' learning, and clinical skills sessions were structured to reinforce the framework's conceptual understanding and enable students to practice delivering fundamental care in an integrated manner. The intervention's impact was explored via a pre-post survey and focus groups. The survey demonstrated that the intervention did not affect students' ability to identify patients' fundamental care needs; however, focus groups showed the intervention assisted students in understanding the complexity of fundamental care and its importance to patients' experiences. The pilot provides preliminary evidence on the importance of embedding fundamental care into nursing curricula early and explicitly, and emphasising the integrated nature of such care, particularly through structured debriefs, consistent terminology, and opportunities for students to experience care as a patient. Copyright © 2018 Elsevier Ltd. All rights reserved.

Subglottal pressure, tracheal airflow, and intrinsic laryngeal muscle activity during rat ultrasound vocalization

PubMed Central

2011-01-01

Vocal production requires complex planning and coordination of respiratory, laryngeal, and vocal tract movements, which are incompletely understood in most mammals. Rats produce a variety of whistles in the ultrasonic range that are of communicative relevance and of importance as a model system, but the sources of acoustic variability were mostly unknown. The goal was to identify sources of fundamental frequency variability. Subglottal pressure, tracheal airflow, and electromyographic (EMG) data from two intrinsic laryngeal muscles were measured during 22-kHz and 50-kHz call production in awake, spontaneously behaving adult male rats. During ultrasound vocalization, subglottal pressure ranged between 0.8 and 1.9 kPa. Pressure differences between call types were not significant. The relation between fundamental frequency and subglottal pressure within call types was inconsistent. Experimental manipulations of subglottal pressure had only small effects on fundamental frequency. Tracheal airflow patterns were also inconsistently associated with frequency. Pressure and flow seem to play a small role in regulation of fundamental frequency. Muscle activity, however, is precisely regulated and very sensitive to alterations, presumably because of effects on resonance properties in the vocal tract. EMG activity of cricothyroid and thyroarytenoid muscle was tonic in calls with slow or no fundamental frequency modulations, like 22-kHz and flat 50-kHz calls. Both muscles showed brief high-amplitude, alternating bursts at rates up to 150 Hz during production of frequency-modulated 50-kHz calls. A differentiated and fine regulation of intrinsic laryngeal muscles is critical for normal ultrasound vocalization. Many features of the laryngeal muscle activation pattern during ultrasound vocalization in rats are shared with other mammals. PMID:21832032

Maxwell's demon in biochemical signal transduction with feedback loop

PubMed Central

Ito, Sosuke; Sagawa, Takahiro

2015-01-01

Signal transduction in living cells is vital to maintain life itself, where information transfer in noisy environment plays a significant role. In a rather different context, the recent intensive research on ‘Maxwell's demon'—a feedback controller that utilizes information of individual molecules—have led to a unified theory of information and thermodynamics. Here we combine these two streams of research, and show that the second law of thermodynamics with information reveals the fundamental limit of the robustness of signal transduction against environmental fluctuations. Especially, we find that the degree of robustness is quantitatively characterized by an informational quantity called transfer entropy. Our information-thermodynamic approach is applicable to biological communication inside cells, in which there is no explicit channel coding in contrast to artificial communication. Our result could open up a novel biophysical approach to understand information processing in living systems on the basis of the fundamental information–thermodynamics link. PMID:26099556

The fundamental downscaling limit of field effect transistors

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

Mamaluy, Denis, E-mail: mamaluy@sandia.gov; Gao, Xujiao

2015-05-11

We predict that within next 15 years a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs) will be reached. Specifically, we show that at room temperatures all FETs, irrespective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths. These findings were confirmed by performing quantum mechanical transport simulations for a variety of 6-, 5-, and 4-nm gate length Si devices, optimized to satisfy high-performance logic specifications by ITRS. Different channel materials and wafer/channel orientations have also been studied; it is found that altering channel-source-drain materials achieves only insignificant increasemore » in switching energy, which overall cannot sufficiently delay the approaching downscaling limit. Alternative possibilities are discussed to continue the increase of logic element densities for room temperature operation below the said limit.« less

[Influence of human personal features on acoustic correlates of speech emotional intonation characteristics].

PubMed

Dmitrieva, E S; Gel'man, V Ia; Zaĭtseva, K A; Orlov, A M

2009-01-01

Comparative study of acoustic correlates of emotional intonation was conducted on two types of speech material: sensible speech utterances and short meaningless words. The corpus of speech signals of different emotional intonations (happy, angry, frightened, sad and neutral) was created using the actor's method of simulation of emotions. Native Russian 20-70-year-old speakers (both professional actors and non-actors) participated in the study. In the corpus, the following characteristics were analyzed: mean values and standard deviations of the power, fundamental frequency, frequencies of the first and second formants, and utterance duration. Comparison of each emotional intonation with "neutral" utterances showed the greatest deviations of the fundamental frequency and frequencies of the first formant. The direction of these deviations was independent of the semantic content of speech utterance and its duration, age, gender, and being actor or non-actor, though the personal features of the speakers affected the absolute values of these frequencies.

Liquid metal enabled pump

PubMed Central

Tang, Shi-Yang; Khoshmanesh, Khashayar; Sivan, Vijay; Petersen, Phred; O’Mullane, Anthony P.; Abbott, Derek; Mitchell, Arnan; Kalantar-zadeh, Kourosh

2014-01-01

Small-scale pumps will be the heartbeat of many future micro/nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics. PMID:24550485

The fundamental downscaling limit of field effect transistors

DOE PAGES

Mamaluy, Denis; Gao, Xujiao

2015-05-12

We predict that within next 15 years a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs) will be reached. Specifically, we show that at room temperatures all FETs, irrespective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths. These findings were confirmed by performing quantum mechanical transport simulations for a variety of 6-, 5-, and 4-nm gate length Si devices, optimized to satisfy high-performance logic specifications by ITRS. Different channel materials and wafer/channel orientations have also been studied; it is found that altering channel-source-drain materials achieves only insignificant increasemore » in switching energy, which overall cannot sufficiently delay the approaching downscaling limit. Alternative possibilities are discussed to continue the increase of logic element densities for room temperature operation below the said limit.« less

Recombination in polymer-fullerene bulk heterojunction solar cells

NASA Astrophysics Data System (ADS)

Cowan, Sarah R.; Roy, Anshuman; Heeger, Alan J.

2010-12-01

Recombination of photogenerated charge carriers in polymer bulk heterojunction (BHJ) solar cells reduces the short circuit current (Jsc) and the fill factor (FF). Identifying the mechanism of recombination is, therefore, fundamentally important for increasing the power conversion efficiency. Light intensity and temperature-dependent current-voltage measurements on polymer BHJ cells made from a variety of different semiconducting polymers and fullerenes show that the recombination kinetics are voltage dependent and evolve from first-order recombination at short circuit to bimolecular recombination at open circuit as a result of increasing the voltage-dependent charge carrier density in the cell. The “missing 0.3 V” inferred from comparison of the band gaps of the bulk heterojunction materials and the measured open-circuit voltage at room-temperature results from the temperature dependence of the quasi-Fermi levels in the polymer and fullerene domains—a conclusion based on the fundamental statistics of fermions.

Experimental determination of the x-ray atomic fundamental parameters of nickel

NASA Astrophysics Data System (ADS)

Ménesguen, Y.; Lépy, M.-C.; Hönicke, P.; Müller, M.; Unterumsberger, R.; Beckhoff, B.; Hoszowska, J.; Dousse, J.-Cl; Błachucki, W.; Ito, Y.; Yamashita, M.; Fukushima, S.

2018-02-01

The x-ray atomic properties of nickel (Ni) were investigated in a unique approach combining different experimental techniques to obtain new, useful and reliable values of atomic fundamental parameters for x-ray spectrometric purposes and for comparison with theoretical predictions. We determined the mass attenuation coefficients in an energy range covering the L- and K-absorption edges, the K-shell fluorescence yield and the Kβ/Kα and Kβ1, 3/Kα1, 2 transition probability ratios. The obtained line profiles and linewidths of the Kα and Kβ transitions in Ni can be considered as the contribution of the satellite lines arising from the [KM] shake processes suggested by Deutsch et al (1995 Phys. Rev. A 51 283) and Ito et al (2016 Phys. Rev. A 94 042506). Comparison of the new data with several databases showed good agreement, but also discrepancies were found with existing tabulated values.

Topologically Nontrivial Magnon Bands in Artificial Square Spin Ices with Dzyaloshinskii-Moriya Interaction

NASA Astrophysics Data System (ADS)

Iacocca, Ezio; Heinonen, Olle

2017-09-01

Systems that exhibit topologically protected edge states are interesting both from a fundamental point of view as well as for potential applications, the latter because of the absence of backscattering and robustness to perturbations. It is desirable to be able to control and manipulate such edge states. Here, we show that artificial square ices can incorporate both features: an interfacial Dzyaloshinskii-Moriya interaction gives rise to topologically nontrivial magnon bands, and the equilibrium state of the spin ice is reconfigurable with different configurations having different magnon dispersions and topology. The topology is found to develop as odd-symmetry bulk and edge magnon bands approach each other so that constructive band inversion occurs in reciprocal space. Our results show that topologically protected bands are supported in square spin ices.

Why anthropic reasoning cannot predict Lambda.

PubMed

Starkman, Glenn D; Trotta, Roberto

2006-11-17

We revisit anthropic arguments purporting to explain the measured value of the cosmological constant. We argue that different ways of assigning probabilities to candidate universes lead to totally different anthropic predictions. As an explicit example, we show that weighting different universes by the total number of possible observations leads to an extremely small probability for observing a value of Lambda equal to or greater than what we now measure. We conclude that anthropic reasoning within the framework of probability as frequency is ill-defined and that in the absence of a fundamental motivation for selecting one weighting scheme over another the anthropic principle cannot be used to explain the value of Lambda, nor, likely, any other physical parameters.

Comparison of intersecting pedestrian flows based on experiments

NASA Astrophysics Data System (ADS)

Zhang, J.; Seyfried, A.

2014-07-01

Intersections of pedestrian flows feature multiple types, varying in the numbers of flow directions as well as intersecting angles. In this article results from intersecting flow experiments with two different intersecting angles are compared. To analyze the transport capabilities the Voronoi method is used to resolve the fine structure of the resulting velocity-density relations and spatial dependence of the measurements. The fundamental diagrams of various flow types are compared and show no apparent difference with respect to the intersecting angle 90° and 180°. This result indicates that head-on conflicts of different types of flow have the same influence on the transport properties of the system, which demonstrates the high self-organization capabilities of pedestrians.

Optical properties of graphene nanoflakes: Shape matters.

PubMed

Mansilla Wettstein, Candela; Bonafé, Franco P; Oviedo, M Belén; Sánchez, Cristián G

2016-06-14

In recent years there has been significant debate on whether the edge type of graphene nanoflakes (GNFs) or graphene quantum dots (GQDs) are relevant for their electronic structure, thermal stability, and optical properties. Using computer simulations, we have proven that there is a fundamental difference in the absorption spectra between samples of the same shape, similar size but different edge type, namely, armchair or zigzag edges. These can be explained by the presence of electronic structures near the Fermi level which are localized on the edges. These features are also evident from the dependence of band gap on the GNF size, which shows three very distinct trends for different shapes and edge geometries.

Optical properties of graphene nanoflakes: Shape matters

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

Mansilla Wettstein, Candela; Bonafé, Franco P.; Sánchez, Cristián G., E-mail: cgsanchez@fcq.unc.edu.ar

In recent years there has been significant debate on whether the edge type of graphene nanoflakes (GNFs) or graphene quantum dots (GQDs) are relevant for their electronic structure, thermal stability, and optical properties. Using computer simulations, we have proven that there is a fundamental difference in the absorption spectra between samples of the same shape, similar size but different edge type, namely, armchair or zigzag edges. These can be explained by the presence of electronic structures near the Fermi level which are localized on the edges. These features are also evident from the dependence of band gap on the GNFmore » size, which shows three very distinct trends for different shapes and edge geometries.« less

Acoustical study of classical Peking Opera singing.

PubMed

Sundberg, Johan; Gu, Lide; Huang, Qiang; Huang, Ping

2012-03-01

Acoustic characteristics of classical opera singing differ considerably between the Western and the Chinese cultures. Singers in the classical Peking opera tradition specialize on one out of a limited number of standard roles. Audio and electroglottograph signals were recorded for four performers of the Old Man role and three performers of the Colorful Face role. Recordings were made of the singers' speech and when they sang recitatives and songs from their roles. Sound pressure level, fundamental frequency, and spectrum characteristics were analyzed. Histograms showing the distribution of fundamental frequency showed marked peaks for the songs, suggesting a scale tone structure. Some of the intervals between these peaks were similar to those used in Western music. Vibrato rate was about 3.5Hz, that is, considerably slower than in Western classical singing. Spectra of vibrato-free tones contained unbroken series of harmonic partials sometimes reaching up to 17 000Hz. Long-term-average spectrum (LTAS) curves showed no trace of a singer's formant cluster. However, the Colorful Face role singers' LTAS showed a marked peak near 3300Hz, somewhat similar to that found in Western pop music singers. The mean LTAS spectrum slope between 700 and 6000Hz decreased by about 0.2dB/octave per dB of equivalent sound level. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Distributed and Dynamic Neural Encoding of Multiple Motion Directions of Transparently Moving Stimuli in Cortical Area MT

PubMed Central

Xiao, Jianbo

2015-01-01

Segmenting visual scenes into distinct objects and surfaces is a fundamental visual function. To better understand the underlying neural mechanism, we investigated how neurons in the middle temporal cortex (MT) of macaque monkeys represent overlapping random-dot stimuli moving transparently in slightly different directions. It has been shown that the neuronal response elicited by two stimuli approximately follows the average of the responses elicited by the constituent stimulus components presented alone. In this scheme of response pooling, the ability to segment two simultaneously presented motion directions is limited by the width of the tuning curve to motion in a single direction. We found that, although the population-averaged neuronal tuning showed response averaging, subgroups of neurons showed distinct patterns of response tuning and were capable of representing component directions that were separated by a small angle—less than the tuning width to unidirectional stimuli. One group of neurons preferentially represented the component direction at a specific side of the bidirectional stimuli, weighting one stimulus component more strongly than the other. Another group of neurons pooled the component responses nonlinearly and showed two separate peaks in their tuning curves even when the average of the component responses was unimodal. We also show for the first time that the direction tuning of MT neurons evolved from initially representing the vector-averaged direction of slightly different stimuli to gradually representing the component directions. Our results reveal important neural processes underlying image segmentation and suggest that information about slightly different stimulus components is computed dynamically and distributed across neurons. SIGNIFICANCE STATEMENT Natural scenes often contain multiple entities. The ability to segment visual scenes into distinct objects and surfaces is fundamental to sensory processing and is crucial for generating the perception of our environment. Because cortical neurons are broadly tuned to a given visual feature, segmenting two stimuli that differ only slightly is a challenge for the visual system. In this study, we discovered that many neurons in the visual cortex are capable of representing individual components of slightly different stimuli by selectively and nonlinearly pooling the responses elicited by the stimulus components. We also show for the first time that the neural representation of individual stimulus components developed over a period of ∼70–100 ms, revealing a dynamic process of image segmentation. PMID:26658869

DIRECT SIMULATION OF A-C MACHINERY.

DTIC Science & Technology

show the application of the simulation to both induction and synchronous machines. The fundamental space harmonic only, the fundamental and third ... space harmonic only, or all the space harmonics are considered. The report concludes that: (1) Successful direct simulation of the 2-phase induction

Combinatorial evaluation of systems including decomposition of a system representation into fundamental cycles

DOEpatents

Oliveira, Joseph S [Richland, WA; Jones-Oliveira, Janet B [Richland, WA; Bailey, Colin G [Wellington, NZ; Gull, Dean W [Seattle, WA

2008-07-01

One embodiment of the present invention includes a computer operable to represent a physical system with a graphical data structure corresponding to a matroid. The graphical data structure corresponds to a number of vertices and a number of edges that each correspond to two of the vertices. The computer is further operable to define a closed pathway arrangement with the graphical data structure and identify each different one of a number of fundamental cycles by evaluating a different respective one of the edges with a spanning tree representation. The fundamental cycles each include three or more of the vertices.

Assessment of The Stability of The H/v Spectral Ratio of Ambient Noise and Comparison With Earthquake Data In The Cologne Area (germany)

NASA Astrophysics Data System (ADS)

Parolai, S.; Richwalski, S. M.; Milkereit, C.; Bormann, P.

Situated in an active tectonic region the highly industrialised Cologne area (Germany) suffers from moderate sized earthquakes. The mitigation of earthquake risk included a microzonation study with ambient seismic noise and earthquake recordings in two field campaigns. The analysis of the ambient noise data using the horizontal-to-vertical (H/V) spectral ratio allowed for mapping the fundamental resonance frequency of soils in this area. Furthermore, adding independent geological information we calculated new relationships between shear-wave velocity, sediment thickness, and resonance frequency. The stability of the H/V ratio of ambient noise was checked with repeated measurements and the following observations and conclusions can be drawn: (1) The fundamental resonance frequency estimated from the peak in the H/V ratio is stable in time but the amplification factor is not. (2) Therefore, the relative amplification vari- ation in the area should be checked systematically with repeated measurements. (3) The thickness of the sediments is reliably retrieved from the fundamental resonance frequency. The H/V ratio of ambient noise recordings was compared with the H/V ratio of earth- quake recordings as well as with the curves obtained by applying the classical spectral ratio technique (using a reference site). The shapes of the spectral ratios obtained by the different methods are generally in good agreement.In addition, the analysis of earthquake data shows that significant amplifications of the ground motion may also occur at frequencies higher than the fundamental one.

Trends in education gradients of 'preventable' mortality: a test of fundamental cause theory.

PubMed

Masters, Ryan K; Link, Bruce G; Phelan, Jo C

2015-02-01

Fundamental cause theory explains persisting associations between socioeconomic status and mortality in terms of personal resources such as knowledge, money, power, prestige, and social connections, as well as disparate social contexts related to these resources. We review evidence concerning fundamental cause theory and test three central claims using the National Health Interview Survey Linked Mortality Files 1986-2004. We then examine cohort-based variation in the associations between a fundamental social cause of disease, educational attainment, and mortality rates from heart disease, other "preventable" causes of death, and less preventable causes of death. We further explore race/ethnic and gender variation in these associations. Overall, findings are consistent with nearly all features of fundamental cause theory. Results show, first, larger education gradients in mortality risk for causes of death that are under greater human control than for less preventable causes of death, and, second, that these gradients grew more rapidly across successive cohorts than gradients for less preventable causes. Results also show that relative sizes and cohort-based changes in the education gradients vary substantially by race/ethnicity and gender. Copyright © 2014 Elsevier Ltd. All rights reserved.

Failing to learn from negative prediction errors: Obesity is associated with alterations in a fundamental neural learning mechanism.

PubMed

Mathar, David; Neumann, Jane; Villringer, Arno; Horstmann, Annette

2017-10-01

Prediction errors (PEs) encode the difference between expected and actual action outcomes in the brain via dopaminergic modulation. Integration of these learning signals ensures efficient behavioral adaptation. Obesity has recently been linked to altered dopaminergic fronto-striatal circuits, thus implying impairments in cognitive domains that rely on its integrity. 28 obese and 30 lean human participants performed an implicit stimulus-response learning paradigm inside an fMRI scanner. Computational modeling and psycho-physiological interaction (PPI) analysis was utilized for assessing PE-related learning and associated functional connectivity. We show that human obesity is associated with insufficient incorporation of negative PEs into behavioral adaptation even in a non-food context, suggesting differences in a fundamental neural learning mechanism. Obese subjects were less efficient in using negative PEs to improve implicit learning performance, despite proper coding of PEs in striatum. We further observed lower functional coupling between ventral striatum and supplementary motor area in obese subjects subsequent to negative PEs. Importantly, strength of functional coupling predicted task performance and negative PE utilization. These findings show that obesity is linked to insufficient behavioral adaptation specifically in response to negative PEs, and to associated alterations in function and connectivity within the fronto-striatal system. Recognition of neural differences as a central characteristic of obesity hopefully paves the way to rethink established intervention strategies: Differential behavioral sensitivity to negative and positive PEs should be considered when designing intervention programs. Measures relying on penalization of unwanted behavior may prove less effective in obese subjects than alternative approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

The role of environment in the observed Fundamental Plane of radio Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Shabala, Stanislav S.

2018-05-01

The optical Fundamental Plane of black hole activity relates radio continuum luminosity of Active Galactic Nuclei to [O III] luminosity and black hole mass. We examine the environments of low redshift (z < 0.2) radio-selected AGN, quantified through galaxy clustering, and find that halo mass provides similar mass scalings to black hole mass in the Fundamental Plane relations. AGN properties are strongly environment-dependent: massive haloes are more likely to host radiatively inefficient (low-excitation) radio AGN, as well as a higher fraction of radio luminous, extended sources. These AGN populations have different radio - optical luminosity scaling relations, and the observed mass scalings in the parent AGN sample are built up by combining populations preferentially residing in different environments. Accounting for environment-driven selection effects, the optical Fundamental Plane of supermassive black holes is likely to be mass-independent, as predicted by models.

Immunotherapy is different: Implications for vaccine clinical trial design.

PubMed

Simon, Richard

2017-09-02

Cancer Immunotherapetics differ fundamentally from most cancer therapies in that they involve manipulation of the immune system to induce an anti-tumor response. This fundamental difference results in differences in the pre-clinical and clinical development of immunotherapeutics. Even the regulatory culture of developing one drug at a time and demonstrating that it, when added to standard therapy, prolongs patient survival, is often not suitable for the development of effective immunotherapy regimens. In this commentary, we explore some of these differences and describe novel clinical trial designs which may be useful in immunotherapeutics regimen development.

Fundamentals and commercial aspects of nanobiosensors in point-of-care clinical diagnostics.

PubMed

Mahato, Kuldeep; Maurya, Pawan Kumar; Chandra, Pranjal

2018-03-01

Among various problems faced by mankind, health-related concerns are prevailing since long which are commonly found in the form of infectious diseases and different metabolic disorders. The clinical cure and management of such abnormalities are greatly dependent on the availability of their diagnoses. The conventional diagnostics used for such purposes are extremely powerful; however, most of these are limited by time-consuming protocols and require higher volume of test sample, etc. A new evolving technology called "biosensor" in this context shows an enormous potential for an alternative diagnostic device, which constantly compliments the conventional diagnoses. In this review, we have summarized different kinds of biosensors and their fundamental understanding with various state-of-the-art examples. A critical examination of different types of biosensing mechanisms is also reported highlighting the advantages of electrochemical biosensors for its great potentials in next-generation commercially viable modules. In recent years, a number of nanomaterials are extensively used to enhance not only the performance of biosensing mechanism, but also obtain robust, cheap, and fabrication-friendly durable mechanism. Herein, we have summarized the importance of nanomaterials in biosensing mechanism, their syntheses as well as characterization techniques. Subsequently, we have discussed the probe fabrication processes along with various techniques for assessing its analytical performances and potentials for commercial viability.

Uncertainty about fundamentals and herding behavior in the FOREX market

NASA Astrophysics Data System (ADS)

Kaltwasser, Pablo Rovira

2010-03-01

It is traditionally assumed in finance models that the fundamental value of assets is known with certainty. Although this is an appealing simplifying assumption it is by no means based on empirical evidence. A simple heterogeneous agent model of the exchange rate is presented. In the model, traders do not observe the true underlying fundamental exchange rate and as a consequence they base their trades on beliefs about this variable. Despite the fact that only fundamentalist traders operate in the market, the model belongs to the heterogeneous agent literature, as traders have different beliefs about the fundamental rate.

The influence of fundamental frequency on perceived duration in spectrally comparable sounds

PubMed Central

Aalto, Daniel; Simko, Juraj; Vainio, Martti

2017-01-01

The perceived duration of a sound is affected by its fundamental frequency and intensity: higher sounds are judged to be longer, as are sounds with greater intensity. Since increasing intensity lengthens the perceived duration of the auditory object, and increasing the fundamental frequency increases the sound’s perceived loudness (up to ca. 3 kHz), frequency modulation of duration could be potentially explained by a confounding effect where the primary cause of the modulation would be variations in intensity. Here, a series of experiments are described that were designed to disentangle the contributions of fundamental frequency, intensity, and duration to perceived loudness and duration. In two forced-choice tasks, participants judged duration and intensity differences between two sounds varying simultaneously in intensity, fundamental frequency, fundamental frequency gliding range, and duration. The results suggest that fundamental frequency and intensity each have an impact on duration judgments, while frequency gliding range did not influence the present results. We also demonstrate that the modulation of perceived duration by sound fundamental frequency cannot be fully explained by the confounding relationship between frequency and intensity. PMID:28879063

The influence of fundamental frequency on perceived duration in spectrally comparable sounds.

PubMed

Dawson, Caitlin; Aalto, Daniel; Simko, Juraj; Vainio, Martti

2017-01-01

The perceived duration of a sound is affected by its fundamental frequency and intensity: higher sounds are judged to be longer, as are sounds with greater intensity. Since increasing intensity lengthens the perceived duration of the auditory object, and increasing the fundamental frequency increases the sound's perceived loudness (up to ca. 3 kHz), frequency modulation of duration could be potentially explained by a confounding effect where the primary cause of the modulation would be variations in intensity. Here, a series of experiments are described that were designed to disentangle the contributions of fundamental frequency, intensity, and duration to perceived loudness and duration. In two forced-choice tasks, participants judged duration and intensity differences between two sounds varying simultaneously in intensity, fundamental frequency, fundamental frequency gliding range, and duration. The results suggest that fundamental frequency and intensity each have an impact on duration judgments, while frequency gliding range did not influence the present results. We also demonstrate that the modulation of perceived duration by sound fundamental frequency cannot be fully explained by the confounding relationship between frequency and intensity.

Nonlinear hybridization of the fundamental eigenmodes of microscopic ferromagnetic ellipses.

PubMed

Demidov, V E; Buchmeier, M; Rott, K; Krzysteczko, P; Münchenberger, J; Reiss, G; Demokritov, S O

2010-05-28

We have studied experimentally with high spatial resolution the nonlinear eigenmodes of microscopic Permalloy elliptical elements. We show that the nonlinearity affects the frequencies of the edge and the center modes in an essentially different way. This leads to repulsion of corresponding resonances and to nonlinear mode hybridization resulting in qualitative modifications of the spatial characteristics of the modes. We find that the nonlinear counterparts of the edge and the center modes simultaneously exhibit features specific for both their linear analogues.

Relative entropy as a universal metric for multiscale errors

NASA Astrophysics Data System (ADS)

Chaimovich, Aviel; Shell, M. Scott

2010-06-01

We show that the relative entropy, Srel , suggests a fundamental indicator of the success of multiscale studies, in which coarse-grained (CG) models are linked to first-principles (FP) ones. We demonstrate that Srel inherently measures fluctuations in the differences between CG and FP potential energy landscapes, and develop a theory that tightly and generally links it to errors associated with coarse graining. We consider two simple case studies substantiating these results, and suggest that Srel has important ramifications for evaluating and designing coarse-grained models.

Relative entropy as a universal metric for multiscale errors.

PubMed

Chaimovich, Aviel; Shell, M Scott

2010-06-01

We show that the relative entropy, Srel, suggests a fundamental indicator of the success of multiscale studies, in which coarse-grained (CG) models are linked to first-principles (FP) ones. We demonstrate that Srel inherently measures fluctuations in the differences between CG and FP potential energy landscapes, and develop a theory that tightly and generally links it to errors associated with coarse graining. We consider two simple case studies substantiating these results, and suggest that Srel has important ramifications for evaluating and designing coarse-grained models.

Similarity analysis between quantum images

NASA Astrophysics Data System (ADS)

Zhou, Ri-Gui; Liu, XingAo; Zhu, Changming; Wei, Lai; Zhang, Xiafen; Ian, Hou

2018-06-01

Similarity analyses between quantum images are so essential in quantum image processing that it provides fundamental research for the other fields, such as quantum image matching, quantum pattern recognition. In this paper, a quantum scheme based on a novel quantum image representation and quantum amplitude amplification algorithm is proposed. At the end of the paper, three examples and simulation experiments show that the measurement result must be 0 when two images are same, and the measurement result has high probability of being 1 when two images are different.

Particles, Cutoffs and Inequivalent Representations

NASA Astrophysics Data System (ADS)

Egg, Matthias; Lam, Vincent; Oldofredi, Andrea

2017-03-01

We critically review the recent debate between Doreen Fraser and David Wallace on the interpretation of quantum field theory, with the aim of identifying where the core of the disagreement lies. We show that, despite appearances, their conflict does not concern the existence of particles or the occurrence of unitarily inequivalent representations. Instead, the dispute ultimately turns on the very definition of what a quantum field theory is. We further illustrate the fundamental differences between the two approaches by comparing them both to the Bohmian program in quantum field theory.

Elastic Instability of Slender Rods in Steady Shear Flow Yields Positive First Normal Stress Differences

NASA Astrophysics Data System (ADS)

Becker, Leif E.; Shelley, Michael J.

2000-11-01

First normal stress differences in shear flow are a fundamental property of Non-Newtonian fluids. Experiments involving dilute suspensions of slender fibers exhibit a sharp transition to non-zero normal stress differences beyond a critical shear rate, but existing continuum theories for rigid rods predict neither this transition nor the corresponding magnitude of this effect. We present the first conclusive evidence that elastic instabilities are predominantly responsible for observed deviations from the dilute suspension theory of rigid rods. Our analysis is based on slender body theory and the equilibrium equations of elastica. A straight slender body executing its Jeffery orbit in Couette flow is subject to axial fluid forcing, alternating between compression and tension. We present a stability analysis showing that elastic instabilities are possible for strong flows. Simulations give the fully non-linear evolution of this shape instability, and show that flexibility of the fibers alone is sufficient to cause both shear-thinning and significant first normal stress differences.

Characterization of direct-current atmospheric-pressure discharges useful for ambient desorption/ionization mass spectrometry.

PubMed

Shelley, Jacob T; Wiley, Joshua S; Chan, George C Y; Schilling, Gregory D; Ray, Steven J; Hieftje, Gary M

2009-05-01

Two relatively new ambient ionization sources, direct analysis in real time (DART) and the flowing atmospheric-pressure afterglow (FAPA), use direct current, atmospheric-pressure discharges to produce reagent ions for the direct ionization of a sample. Although at a first glance these two sources appear similar, a fundamental study reveals otherwise. Specifically, DART was found to operate with a corona-to-glow transition (C-G) discharge whereas the FAPA was found to operate with a glow-to-arc transition (G-A) discharge. The characteristics of both discharges were evaluated on the basis of four factors: reagent-ion production, response to a model analyte (ferrocene), infrared (IR) thermography of the gas used for desorption and ionization, and spatial emission characteristics. The G-A discharge produced a greater abundance and a wider variety of reagent ions than the C-G discharge. In addition, the discharges yielded different adducts and signal strengths for ferrocene. It was also found that the gas exiting the discharge chamber reached a maximum of 235 degrees C and 55 degrees C for the G-A and C-G discharges, respectively. Finally, spatially resolved emission maps of both discharges showed clear differences for N(2)(+) and O(I). These findings demonstrate that the discharges used by FAPA and DART are fundamentally different and should have different optimal applications for ambient desorption/ionization mass spectrometry (ADI-MS).

Children's Use of the Prosodic Characteristics of Infant-Directed Speech.

ERIC Educational Resources Information Center

Weppelman, Tammy L.; Bostow, Angela; Schiffer, Ryan; Elbert-Perez, Evelyn; Newman, Rochelle S.

2003-01-01

Examined whether young children (4 years of age) show prosodic changes when speaking to infants. Measured children's word duration in infant-directed speech compared to adult-directed speech, examined amplitude variability, and examined both average fundamental frequency and fundamental frequency standard deviation. Results indicate that…

Thermodynamics of statistical inference by cells.

PubMed

Lang, Alex H; Fisher, Charles K; Mora, Thierry; Mehta, Pankaj

2014-10-03

The deep connection between thermodynamics, computation, and information is now well established both theoretically and experimentally. Here, we extend these ideas to show that thermodynamics also places fundamental constraints on statistical estimation and learning. To do so, we investigate the constraints placed by (nonequilibrium) thermodynamics on the ability of biochemical signaling networks to estimate the concentration of an external signal. We show that accuracy is limited by energy consumption, suggesting that there are fundamental thermodynamic constraints on statistical inference.

Water beetle tolerance to salinity and anionic composition and its relationship to habitat occupancy.

PubMed

Céspedes, V; Pallarés, S; Arribas, P; Millán, A; Velasco, J

2013-10-01

Water salinity and ionic composition are among the main environmental variables that constrain the fundamental niches of aquatic species, and accordingly, physiological tolerance to these factors constitutes a crucial part of the evolution, ecology, and biogeography of these organisms. The present study experimentally estimated the fundamental saline and anionic niches of adults of two pairs of congeneric saline beetle species that differ in habitat preference (lotic and lentic) in order to test the habitat constraint hypothesis. Osmotic and anionic realised niches were also estimated based on the field occurrences of adult beetle species using Outlying Mean Index analysis and their relationship with experimental tolerances. In the laboratory, all of the studied species showed a threshold response to increased salinity, displaying high survival times when exposed to low and intermediate conductivity levels. These results suggest that these species are not strictly halophilic, but that they are able to regulate both hyperosmotically and hypoosmotically. Anionic water composition had a significant effect on salinity tolerance at conductivity levels near their upper tolerance limits, with decreased species survival at elevated sulphate concentrations. Species occupying lentic habitats demonstrated higher salinity tolerance than their lotic congeners in agreement with the habitat constraint hypothesis. As expected, realised salinity niches were narrower than fundamental niches and corresponded to conditions near the upper tolerance limits of the species. These species are uncommon on freshwater-low conductivity habitats despite the fact that these conditions might be physiologically suitable for the adult life stage. Other factors, such as biotic interactions, could prevent their establishment at low salinities. Differences in the realised anionic niches of congeneric species could be partially explained by the varying habitat availability in the study area. Combining the experimental estimation of fundamental niches with realised field data niche estimates is a powerful method for understanding the main factors constraining species' distribution at multiple scales, which is a key issue when predicting species' ability to cope with global change. Copyright © 2013 Elsevier Ltd. All rights reserved.

a Comparative Analysis of Fluent and Cerebral Palsied Speech.

NASA Astrophysics Data System (ADS)

van Doorn, Janis Lee

Several features of the acoustic waveforms of fluent and cerebral palsied speech were compared, using six fluent and seven cerebral palsied subjects, with a major emphasis being placed on an investigation of the trajectories of the first three formants (vocal tract resonances). To provide an overall picture which included other acoustic features, fundamental frequency, intensity, speech timing (speech rate and syllable duration), and prevocalization (vocalization prior to initial stop consonants found in cerebral palsied speech) were also investigated. Measurements were made using repetitions of a test sentence which was chosen because it required large excursions of the speech articulators (lips, tongue and jaw), so that differences in the formant trajectories for the fluent and cerebral palsied speakers would be emphasized. The acoustic features were all extracted from the digitized speech waveform (10 kHz sampling rate): the fundamental frequency contours were derived manually, the intensity contours were measured using the signal covariance, speech rate and syllable durations were measured manually, as were the prevocalization durations, while the formant trajectories were derived from short time spectra which were calculated for each 10 ms of speech using linear prediction analysis. Differences which were found in the acoustic features can be summarized as follows. For cerebral palsied speakers, the fundamental frequency contours generally showed inappropriate exaggerated fluctuations, as did some of the intensity contours; the mean fundamental frequencies were either higher or the same as for the fluent subjects; speech rates were reduced, and syllable durations were longer; prevocalization was consistently present at the beginning of the test sentence; formant trajectories were found to have overall reduced frequency ranges, and to contain anomalous transitional features, but it is noteworthy that for any one cerebral palsied subject, the inappropriate trajectory pattern was generally reproducible. The anomalous transitional features took the form of (a) inappropriate transition patterns, (b) reduced frequency excursions, (c) increased transition durations, and (d) decreased maximum rates of frequency change.

Species differences in unlocking B-side electron transfer in bacterial reaction centers

DOE PAGES

Dylla, Nicholas P.; Faries, Kaitlyn M.; Wyllie, Ryan M.; ...

2016-06-21

The structure of the bacterial photosynthetic reaction center (RC) reveals symmetry-related electron transfer (ET) pathways, but only one path is used in native RCs. Analogous mutations have been made in two Rhodobacter (R.) species. A glutamic acid at position 133 in the M subunit increases transmembrane charge separation via the naturally inactive (B-side) path through impacts on primary ET in mutant R. sphaeroidesRCs. Prior work showed that the analogous substitution in the R. capsulatusRC also increases B-side activity, but mainly affects secondary ET. Finally, the overall yields of transmembrane ET are similar, but enabled in fundamentally different ways.

Species differences in unlocking B-side electron transfer in bacterial reaction centers

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

Dylla, Nicholas P.; Faries, Kaitlyn M.; Wyllie, Ryan M.

The structure of the bacterial photosynthetic reaction center (RC) reveals symmetry-related electron transfer (ET) pathways, but only one path is used in native RCs. Analogous mutations have been made in two Rhodobacter (R.) species. A glutamic acid at position 133 in the M subunit increases transmembrane charge separation via the naturally inactive (B-side) path through impacts on primary ET in mutant R. sphaeroidesRCs. Prior work showed that the analogous substitution in the R. capsulatusRC also increases B-side activity, but mainly affects secondary ET. Finally, the overall yields of transmembrane ET are similar, but enabled in fundamentally different ways.

Epitaxial lateral overgrowth of GaAs: effect of doping on LPE growth behaviour

NASA Astrophysics Data System (ADS)

Zytkiewicz, Z. R.; Dobosz, D.; Pawlowska, M.

1999-05-01

Results of epitaxial lateral overgrowth (ELO) of GaAs on (001) GaAs substrates by liquid phase epitaxy are reported. We show that by introducing Si, Sn or Te impurities to the Ga-As solution the vertical growth rate is reduced while the lateral growth rate is significantly enhanced, which leads to a growth habit modification. Furthermore, the impurity incorporation into the growing layer is different on the upper and side surfaces of the ELO, reflecting the fundamental differences between the lateral and vertical growth modes. This phenomenon can be applied for studying the temporal development of ELO layers.

Linking Carbon Flux Dynamics and Soil Structure in Dryland Soils

NASA Astrophysics Data System (ADS)

DeCarlo, K. F.; Caylor, K. K.

2016-12-01

Biological sources in the form of microbes and plants play a fundamental role in determining the magnitude of carbon flux. However, the geophysical structure of the soil (which the carbon must pass through before entering the atmosphere) often serves as a constraining entity, which has the potential to serve as instigators or mitigators of those carbon and hydrologic flux processes. We characterized soil carbon dynamics in three dryland soil systems: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer (IRGA). Structure of the soil systems, with a focus on the macro-crack structure, were characterized using a combined resin-casting/X-ray imaging technique. Results show fundamental differences in carbon dynamics between the different soil systems/structures: control soils have gaussian distributions of carbon flux that decrease with progressive drying of the soil, while biocompacted soils exhibit exponentially distributed fluxes that do not regularly decrease with increased drying of the soil. Bioturbated soils also exhibit an exponential distribution of carbon flux, though at a much higher magnitude. These differences are evaluated in the context of the underlying soil structure: while the control soils exhibit a shallow and narrow crack structure, the biocompacted soils exhibit a "systematic" crack network with moderate cracking intensity and large depth. The deep crack networks of the biocompacted soils may serve to physically enhance an otherwise weak source of carbon via advection and/or convection, inducing fluxes that are equal or greater than an otherwise carbon-rich soil. The bioturbated soils exhibit a "surficial" crack network that is shallow but extensive, but additionally have deep holes known to convectively vent carbon, which may explain their periodically large carbon fluxes. Our results suggest that variability in soil structure, as well as carbon source, plays a fundamental role in carbon flux dynamics, and the importance of evaluating biological carbon source and geophysical soil structure in a dryland environment.

Restraint: Recalibrating American Strategy

DTIC Science & Technology

2010-06-01

paper considers the implications of America’s diminishing resources and increasing commitments, and considers fundamental ways in which America...focus on essential commitments. | 7 I I . T W O H I S TO R I C I M P U L S e S Despite fundamental differences between President Obama and...ask whether this was the best focus or just another example of overstretch and failure to accomplish America’s most fundamental goals by trying to

Determination of Reference Catalogs for Meridian Observations Using Statistical Method

NASA Astrophysics Data System (ADS)

Li, Z. Y.

2014-09-01

The meridian observational data are useful for developing high-precision planetary ephemerides of the solar system. These historical data are provided by the jet propulsion laboratory (JPL) or the Institut De Mecanique Celeste Et De Calcul Des Ephemerides (IMCCE). However, we find that the reference systems (realized by the fundamental catalogs FK3 (Third Fundamental Catalogue), FK4 (Fourth Fundamental Catalogue), and FK5 (Fifth Fundamental Catalogue), or Hipparcos), to which the observations are referred, are not given explicitly for some sets of data. The incompleteness of information prevents us from eliminating the systematic effects due to the different fundamental catalogs. The purpose of this paper is to specify clearly the reference catalogs of these observations with the problems in their records by using the JPL DE421 ephemeris. The data for the corresponding planets in the geocentric celestial reference system (GCRS) obtained from the DE421 are transformed to the apparent places with different hypothesis regarding the reference catalogs. Then the validations of the hypothesis are tested by two kinds of statistical quantities which are used to indicate the significance of difference between the original and transformed data series. As a result, this method is proved to be effective for specifying the reference catalogs, and the missed information is determined unambiguously. Finally these meridian data are transformed to the GCRS for further applications in the development of planetary ephemerides.

Suppressive mechanisms in visual motion processing: from perception to intelligence

PubMed Central

Tadin, Duje

2015-01-01

Perception operates on an immense amount of incoming information that greatly exceeds the brain's processing capacity. Because of this fundamental limitation, the ability to suppress irrelevant information is a key determinant of perceptual efficiency. Here, I will review a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. These spatial suppression mechanisms are adaptive, operating only when sensory inputs are sufficiently robust to guarantee visibility. Converging correlational and causal evidence links these behavioral results with inhibitory center-surround mechanisms, namely those in cortical area MT. Spatial suppression is abnormally weak in several special populations, including the elderly and those with schizophrenia—a deficit that is evidenced by better-than-normal direction discriminations of large moving stimuli. Theoretical work shows that this abnormal weakening of spatial suppression should result in motion segregation deficits, but direct behavioral support of this hypothesis is lacking. Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, I will discuss recent research that shows individual differences in spatial suppression of motion signals strongly predict individual variations in IQ scores. PMID:26299386

Kinetic features revealed by top-hat electrostatic analysers: numerical simulations and instrument response results

NASA Astrophysics Data System (ADS)

De Marco, Rossana; Marcucci, Maria Federica; Brienza, Daniele; Bruno, Roberto; Consolini, Giuseppe; Perrone, Denise; Valentini, Franceso; Servidio, Sergio; Stabile, Sara; Pezzi, Oreste; Sorriso-Valvo, Luca; Lavraud, Benoit; De Keyser, Johan; Retinò, Alessandro; Fazakerley, Andrew; Wicks, Robert; Vaivads, Andris; Salatti, Mario; Veltri, Pierliugi

2017-04-01

Turbulence Heating ObserveR (THOR) is the first mission devoted to study energization, acceleration and heating of turbulent space plasmas, and designed to perform field and particle measurements at kinetic scales in different near-Earth regions and in the solar wind. Solar Orbiter (SolO), together with Solar Probe Plus, will provide the first comprehensive remote and in situ measurements which are critical to establish the fundamental physical links between the Sun's dynamic atmosphere and the turbulent solar wind. The fundamental process of turbulent dissipation is mediated by physical mechanism that occur at a variety of temporal and spatial scales, and most efficiently at the kinetics scales. Hybrid Vlasov-Maxwell simulations of solar-wind turbulence show that kinetic effects manifest as particle beams, production of temperature anisotropies and ring-like modulations, preferential heating of heavy ions. We use a numerical code able to reproduce the response of a typical electrostatic analyzer of top-hat type starting from velocity distribution functions (VDFs) generated by Hybrid Vlasov-Maxwell (HVM) numerical simulations. Here, we show how optimized particle measurements by top-hat analysers can capture the kinetic features injected by turbulence in the VDFs.

Scaling in Transportation Networks

PubMed Central

Louf, Rémi; Roth, Camille; Barthelemy, Marc

2014-01-01

Subway systems span most large cities, and railway networks most countries in the world. These networks are fundamental in the development of countries and their cities, and it is therefore crucial to understand their formation and evolution. However, if the topological properties of these networks are fairly well understood, how they relate to population and socio-economical properties remains an open question. We propose here a general coarse-grained approach, based on a cost-benefit analysis that accounts for the scaling properties of the main quantities characterizing these systems (the number of stations, the total length, and the ridership) with the substrate's population, area and wealth. More precisely, we show that the length, number of stations and ridership of subways and rail networks can be estimated knowing the area, population and wealth of the underlying region. These predictions are in good agreement with data gathered for about subway systems and more than railway networks in the world. We also show that train networks and subway systems can be described within the same framework, but with a fundamental difference: while the interstation distance seems to be constant and determined by the typical walking distance for subways, the interstation distance for railways scales with the number of stations. PMID:25029528

A Note for Graphing Calculators in the Fundamental Finance Course

ERIC Educational Resources Information Center

Chen, Jeng-Hong

2011-01-01

The financial calculator is incorporated in finance education. In class, the instructor shows students how to use the financial calculator's function keys to solve time value of money (TVM) related problems efficiently. The fundamental finance course is required for all majors in the business school. Some students, especially…

Disease spread in age structured populations with maternal age effects.

PubMed

Clark, Jessica; Garbutt, Jennie S; McNally, Luke; Little, Tom J

2017-04-01

Fundamental ecological processes, such as extrinsic mortality, determine population age structure. This influences disease spread when individuals of different ages differ in susceptibility or when maternal age determines offspring susceptibility. We show that Daphnia magna offspring born to young mothers are more susceptible than those born to older mothers, and consider this alongside previous observations that susceptibility declines with age in this system. We used a susceptible-infected compartmental model to investigate how age-specific susceptibility and maternal age effects on offspring susceptibility interact with demographic factors affecting disease spread. Our results show a scenario where an increase in extrinsic mortality drives an increase in transmission potential. Thus, we identify a realistic context in which age effects and maternal effects produce conditions favouring disease transmission. © 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Relationship of physical activity to fundamental movement skills among adolescents.

PubMed

Okely, A D; Booth, M L; Patterson, J W

2001-11-01

To determine the relationship of participation in organized and nonorganized physical activity with fundamental movement skills among adolescents. Male and female children in Grade 8 (mean age, 13.3 yr) and Grade 10 (mean age, 15.3 yr) were assessed on six fundamental movement skills (run, vertical jump, catch, overhand throw, forehand strike, and kick). Physical activity was assessed using a self-report recall measure where students reported the type, duration, and frequency of participation in organized physical activity and nonorganized physical activity during a usual week. Multiple regression analysis indicated that fundamental movement skills significantly predicted time in organized physical activity, although the percentage of variance it could explain was small. This prediction was stronger for girls than for boys. Multiple regression analysis showed no relationship between time in nonorganized physical activity and fundamental movement skills. Fundamental movement skills are significantly associated with adolescents' participation in organized physical activity, but predict only a small portion of it.

Maintaining Genome Stability: The Role of Helicases and Deaminases

DTIC Science & Technology

2008-07-01

deaminases. The cells response to different forms of damage is fundamental to its ability to repair itself when challenged by environmental or...Page 4 of 12 INTRODUCTION Genomic DNA stores all the information for living organisms. The faithful duplication the maintanance of DNA are...maturation of the immune system by modifying enzymes called deaminases. The cells response to different forms of damage is fundamental to its ability to

Gender differences in children's voice use in a day care environment.

PubMed

Nygren, Mariana; Tyboni, Mikaela; Lindström, Fredric; McAllister, Anita; van Doorn, Jan

2012-11-01

The prevalence of dysphonia is higher in boys than in girls before puberty. This could be because of the differences in boys' and girls' voice use. Previous research on gender differences in prepubescent children's voice parameters has been contradictory. Most studies have focused on examining fundamental frequency. The purpose of this study was to investigate voice use in boys and girls in a day care environment based on the voice parameters fundamental frequency (Hz), vocal intensity (dB SPL), and phonation time (%) and to ascertain whether there were any significant gender differences. Prospective comparative design. The study was conducted in a day care environment where 30 children (17 boys and 13 girls aged 4-5 years) participated. The participants' voices were measured continuously for 4 hours with a voice accumulator that registered fundamental frequency, vocal intensity level, phonation time, and background noise. Mean (standard deviation) fundamental frequency was 310 (22) and 321 (16) Hz, vocal intensity was 93 (4) and 91 (3) dB SPL, and phonation time was 7.7 (2.0)% and 7.6 (2.5)% for boys and girls, respectively. No differences between genders were statistically significant. The finding of no statistically significant gender differences for measurements of voice parameters in a group of children aged 4-5 years in a day care environment is an important finding that contributes to increased knowledge about young boys' and girls' voice use. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Fundamental period of Italian reinforced concrete buildings: comparison between numerical, experimental and Italian code simplified values

NASA Astrophysics Data System (ADS)

Ditommaso, Rocco; Carlo Ponzo, Felice; Auletta, Gianluca; Iacovino, Chiara; Nigro, Antonella

2015-04-01

Aim of this study is a comparison among the fundamental period of reinforced concrete buildings evaluated using the simplified approach proposed by the Italian Seismic code (NTC 2008), numerical models and real values retrieved from an experimental campaign performed on several buildings located in Basilicata region (Italy). With the intention of proposing simplified relationships to evaluate the fundamental period of reinforced concrete buildings, scientists and engineers performed several numerical and experimental campaigns, on different structures all around the world, to calibrate different kind of formulas. Most of formulas retrieved from both numerical and experimental analyses provides vibration periods smaller than those suggested by the Italian seismic code. However, it is well known that the fundamental period of a structure play a key role in the correct evaluation of the spectral acceleration for seismic static analyses. Generally, simplified approaches impose the use of safety factors greater than those related to in depth nonlinear analyses with the aim to cover possible unexpected uncertainties. Using the simplified formula proposed by the Italian seismic code the fundamental period is quite higher than fundamental periods experimentally evaluated on real structures, with the consequence that the spectral acceleration adopted in the seismic static analysis may be significantly different than real spectral acceleration. This approach could produces a decreasing in safety factors obtained using linear and nonlinear seismic static analyses. Finally, the authors suggest a possible update of the Italian seismic code formula for the simplified estimation of the fundamental period of vibration of existing RC buildings, taking into account both elastic and inelastic structural behaviour and the interaction between structural and non-structural elements. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2014 - RS4 ''Seismic observatory of structures and health monitoring''. References R. Ditommaso, M. Vona, M. R. Gallipoli and M. Mucciarelli (2013). Evaluation and considerations about fundamental periods of damaged reinforced concrete buildings. Nat. Hazards Earth Syst. Sci., 13, 1903-1912, 2013. www.nat-hazards-earth-syst-sci.net/13/1903/2013. doi:10.5194/nhess-13-1903-2013

Study on Effects of the Stochastic Delay Probability for 1d CA Model of Traffic Flow

NASA Astrophysics Data System (ADS)

Xue, Yu; Chen, Yan-Hong; Kong, Ling-Jiang

Considering the effects of different factors on the stochastic delay probability, the delay probability has been classified into three cases. The first case corresponding to the brake state has a large delay probability if the anticipant velocity is larger than the gap between the successive cars. The second one corresponding to the following-the-leader rule has intermediate delay probability if the anticipant velocity is equal to the gap. Finally, the third case is the acceleration, which has minimum delay probability. The fundamental diagram obtained by numerical simulation shows the different properties compared to that by the NaSch model, in which there exist two different regions, corresponding to the coexistence state, and jamming state respectively.

Structural and vibrational investigations of a neurotransmitter molecule: Serotonin (5-hydroxy tryptamine)

NASA Astrophysics Data System (ADS)

Jha, Omkant; Yadav, R. A.

2016-11-01

Structural and vibrational studies have been carried out for the most stable conformer of serotonin (5-HT) at the DFT/B3LYP/6-311++G** level using the Gaussian 09 software. In light of the computed vibrational parameters the observed IR and Raman frequencies have been analyzed. To help assign the vibrational fundamentals the GAR2PED software has been used to compute PEDs. Several of the fundamentals are drastically changed in going from indole to serotonin. The two NH bonds of the NH2 group are slightly different possibly due to bonding of the two H atoms of the NH2 group with different atoms. The rocking and wagging modes of the NH2 groups show mixing with the other modes while the remaining four modes are pure group modes. The Kekule phenyl ring stretching mode is found to remain almost unchanged. The HOMO-LUMO energy gap supports to pharmacological active property of the serotonin molecule. The HOMO and LUMO study suggests the existence of charge transfer within the molecule. The NBO analysis has been carried out to gather information regarding the proper and improper hydrogen bonds.

Phonon Surface Scattering and Thermal Energy Distribution in Superlattices.

PubMed

Kothari, Kartik; Maldovan, Martin

2017-07-17

Thermal transport at small length scales has attracted significant attention in recent years and various experimental and theoretical methods have been developed to establish the reduced thermal conductivity. The fundamental understanding of how phonons move and the physical mechanisms behind nanoscale thermal transport, however, remains poorly understood. Here we move beyond thermal conductivity calculations and provide a rigorous and comprehensive physical description of thermal phonon transport in superlattices by solving the Boltzmann transport equation and using the Beckman-Kirchhoff surface scattering theory with shadowing to precisely describe phonon-surface interactions. We show that thermal transport in superlattices can be divided in two different heat transport modes having different physical properties at small length scales: layer-restricted and extended heat modes. We study how interface conditions, periodicity, and composition can be used to manipulate the distribution of thermal energy flow among such layer-restricted and extended heat modes. From predicted frequency and mean free path spectra of superlattices, we also investigate the existence of wave effects. The results and insights in this paper advance the fundamental understanding of heat transport in superlattices and the prospects of rationally designing thermal systems with tailored phonon transport properties.

Impact of branching on the elasticity of actin networks

PubMed Central

Pujol, Thomas; du Roure, Olivia; Fermigier, Marc; Heuvingh, Julien

2012-01-01

Actin filaments play a fundamental role in cell mechanics: assembled into networks by a large number of partners, they ensure cell integrity, deformability, and migration. Here we focus on the mechanics of the dense branched network found at the leading edge of a crawling cell. We develop a new technique based on the dipolar attraction between magnetic colloids to measure mechanical properties of branched actin gels assembled around the colloids. This technique allows us to probe a large number of gels and, through the study of different networks, to access fundamental relationships between their microscopic structure and their mechanical properties. We show that the architecture does regulate the elasticity of the network: increasing both capping and branching concentrations strongly stiffens the networks. These effects occur at protein concentrations that can be regulated by the cell. In addition, the dependence of the elastic modulus on the filaments’ flexibility and on increasing internal stress has been studied. Our overall results point toward an elastic regime dominated by enthalpic rather than entropic deformations. This result strongly differs from the elasticity of diluted cross-linked actin networks and can be explained by the dense dendritic structure of lamellipodium-like networks. PMID:22689953

Beyond illusion: Psychoanalysis and the question of religious truth.

PubMed

Blass, Rachel B

2004-06-01

In this paper the author critically examines the nature of the positive, reconciliatory attitude towards religion that has become increasingly prevalent within psychoanalytic thinking and writing over the past 20 years. She shows how this positive attitude rests on a change in the nature of the prototype of religion and its reassignment to the realm of illusion, thus making irrelevant an issue most central both to psychoanalysis and to traditional Judeo-Christian belief--the passionate search for truth. The author demonstrates how the concern with truth, and specifically with the truth of religious claims, lies at the basis of the opposition between psychoanalysis and religion but, paradoxically, also provides the common ground for dialogue between the two. She argues that, as Freud developed his ideas regarding the origin of conviction in religious claims in his Moses and monotheism (1939), the nature of this common ground was expanded and the dialogue became potentially more meaningful. The author concludes that meaningful dialogue emerges through recognition of fundamental differences rather than through harmonisation within a realm of illusion. In this light, the present study may also be seen as an attempt to recognise fundamental differences that have been evolving within psychoanalysis itself.

Probing atomic Higgs-like forces at the precision frontier

NASA Astrophysics Data System (ADS)

Delaunay, Cédric; Ozeri, Roee; Perez, Gilad; Soreq, Yotam

2017-11-01

We propose a novel approach to probe new fundamental interactions using isotope shift spectroscopy in atomic clock transitions. As a concrete toy example we focus on the Higgs boson couplings to the building blocks of matter: the electron and the up and down quarks. We show that the attractive Higgs force between nuclei and their bound electrons, which is poorly constrained, might induce effects that are larger than the current experimental sensitivities. More generically, we discuss how new interactions between the electron and the neutrons, mediated via light new degrees of freedom, may lead to measurable nonlinearities in a King plot comparison between isotope shifts of two different transitions. Given state-of-the-art accuracy in frequency comparison, isotope shifts have the potential to be measured with sub-Hz accuracy, thus potentially enabling the improvement of current limits on new fundamental interactions. A candidate atomic system for this measurement requires two different clock transitions and four zero nuclear spin isotopes. We identify several systems that satisfy this requirement and also briefly discuss existing measurements. We consider the size of the effect related to the Higgs force and the requirements for it to produce an observable signal.

Near-Field Sound Localization Based on the Small Profile Monaural Structure

PubMed Central

Kim, Youngwoong; Kim, Keonwook

2015-01-01

The acoustic wave around a sound source in the near-field area presents unconventional properties in the temporal, spectral, and spatial domains due to the propagation mechanism. This paper investigates a near-field sound localizer in a small profile structure with a single microphone. The asymmetric structure around the microphone provides a distinctive spectral variation that can be recognized by the dedicated algorithm for directional localization. The physical structure consists of ten pipes of different lengths in a vertical fashion and rectangular wings positioned between the pipes in radial directions. The sound from an individual direction travels through the nearest open pipe, which generates the particular fundamental frequency according to the acoustic resonance. The Cepstral parameter is modified to evaluate the fundamental frequency. Once the system estimates the fundamental frequency of the received signal, the length of arrival and angle of arrival (AoA) are derived by the designed model. From an azimuthal distance of 3–15 cm from the outer body of the pipes, the extensive acoustic experiments with a 3D-printed structure show that the direct and side directions deliver average hit rates of 89% and 73%, respectively. The closer positions to the system demonstrate higher accuracy, and the overall hit rate performance is 78% up to 15 cm away from the structure body. PMID:26580618

Pneumatic oscillator circuits for timing and control of integrated microfluidics.

PubMed

Duncan, Philip N; Nguyen, Transon V; Hui, Elliot E

2013-11-05

Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices.

Measurement of attenuation coefficients of the fundamental and second harmonic waves in water

NASA Astrophysics Data System (ADS)

Zhang, Shuzeng; Jeong, Hyunjo; Cho, Sungjong; Li, Xiongbing

2016-02-01

Attenuation corrections in nonlinear acoustics play an important role in the study of nonlinear fluids, biomedical imaging, or solid material characterization. The measurement of attenuation coefficients in a nonlinear regime is not easy because they depend on the source pressure and requires accurate diffraction corrections. In this work, the attenuation coefficients of the fundamental and second harmonic waves which come from the absorption of water are measured in nonlinear ultrasonic experiments. Based on the quasilinear theory of the KZK equation, the nonlinear sound field equations are derived and the diffraction correction terms are extracted. The measured sound pressure amplitudes are adjusted first for diffraction corrections in order to reduce the impact on the measurement of attenuation coefficients from diffractions. The attenuation coefficients of the fundamental and second harmonics are calculated precisely from a nonlinear least squares curve-fitting process of the experiment data. The results show that attenuation coefficients in a nonlinear condition depend on both frequency and source pressure, which are much different from a linear regime. In a relatively lower drive pressure, the attenuation coefficients increase linearly with frequency. However, they present the characteristic of nonlinear growth in a high drive pressure. As the diffraction corrections are obtained based on the quasilinear theory, it is important to use an appropriate source pressure for accurate attenuation measurements.

Reduced adaptability, but no fundamental disruption, of norm-based face-coding mechanisms in cognitively able children and adolescents with autism.

PubMed

Rhodes, Gillian; Ewing, Louise; Jeffery, Linda; Avard, Eleni; Taylor, Libby

2014-09-01

Faces are adaptively coded relative to visual norms that are updated by experience. This coding is compromised in autism and the broader autism phenotype, suggesting that atypical adaptive coding of faces may be an endophenotype for autism. Here we investigate the nature of this atypicality, asking whether adaptive face-coding mechanisms are fundamentally altered, or simply less responsive to experience, in autism. We measured adaptive coding, using face identity aftereffects, in cognitively able children and adolescents with autism and neurotypical age- and ability-matched participants. We asked whether these aftereffects increase with adaptor identity strength as in neurotypical populations, or whether they show a different pattern indicating a more fundamental alteration in face-coding mechanisms. As expected, face identity aftereffects were reduced in the autism group, but they nevertheless increased with adaptor strength, like those of our neurotypical participants, consistent with norm-based coding of face identity. Moreover, their aftereffects correlated positively with face recognition ability, consistent with an intact functional role for adaptive coding in face recognition ability. We conclude that adaptive norm-based face-coding mechanisms are basically intact in autism, but are less readily calibrated by experience. Copyright © 2014 Elsevier Ltd. All rights reserved.

Socioeconomic determinants of childhood overweight and obesity in China: the long arm of institutional power.

PubMed

Fu, Qiang; George, Linda K

2015-07-01

Previous studies have widely reported that the association between socioeconomic status (SES) and childhood overweight and obesity in China is significant and positive, which lends little support to the fundamental-cause perspective. Using multiple waves (1997, 2000, 2004 and 2006) of the China Health and Nutrition Survey (CHNS) (N = 2,556, 2,063, 1,431 and 1,242, respectively) and continuous BMI cut-points obtained from a polynomial method, (mixed-effect) logistic regression analyses show that parental state-sector employment, an important, yet overlooked, indicator of political power during the market transformation has changed from a risk factor for childhood overweight/obesity in 1997 to a protective factor for childhood overweight/obesity in 2006. Results from quantile regression analyses generate the same conclusions and demonstrate that the protective effect of parental state sector employment at high percentiles of BMI is robust under different estimation strategies. By bridging the fundamental causes perspective and theories of market transformation, this research not only documents the effect of political power on childhood overweight/obesity but also calls for the use of multifaceted, culturally-relevant stratification measures in testing the fundamental cause perspective across time and space. © 2015 Foundation for the Sociology of Health & Illness.

Fundamental-mode MMF transmission enabled by mode conversion

NASA Astrophysics Data System (ADS)

Wu, Zhongying; Li, Juhao; Tian, Yu; Ge, Dawei; Zhu, Jinglong; Ren, Fang; Mo, Qi; Yu, Jinyi; Li, Zhengbin; Chen, Zhangyuan; He, Yongqi

2018-03-01

Modal dispersion in conventional multi-mode fiber (MMF) will cause serious signal degradation and an effective solution is to restrict the signal transmission in the fundamental mode of MMF. In this paper, unlike previous methods by filtering out higher-order modes, we propose to adopt low-modal-crosstalk mode converters to realize fundamental-mode MMF transmission. We design and fabricate all-fiber mode-selective couplers (MSC), which perform mode conversion between the fundamental mode in single-mode fiber (SMF) and fundamental mode in MMF. The proposed scheme is experimentally compared with center launching method under different MMF links and then its wavelength division multiplexing (WDM) transmission performance is investigated. Experimental results indicate that the proposed mode conversion scheme could achieve better transmission performance and works well for the whole C-band.

Fundamental movement skills and physical fitness as predictors of physical activity: A 6-year follow-up study.

PubMed

Jaakkola, T; Yli-Piipari, S; Huotari, P; Watt, A; Liukkonen, J

2016-01-01

The purpose of this study was to examine the extent to which fundamental movement skills and physical fitness scores assessed in early adolescence predict self-reported physical activity assessed 6 years later. The sample comprised 333 (200 girls, 133 boys; M age = 12.41) students. The effects of previous physical activity, sex, and body mass index (BMI) were controlled in the main analyses. Adolescents' fundamental movement skills, physical fitness, self-report physical activity, and BMI were collected at baseline, and their self-report energy expenditure (metabolic equivalents: METs) and intensity of physical activity were collected using the International Physical Activity Questionnaire 6 years later. Results showed that fundamental movement skills predicted METs, light, moderate, and vigorous intensity physical activity levels, whereas fitness predicted METs, moderate, and vigorous physical activity levels. Hierarchical regression analyses also showed that after controlling for previous levels of physical activity, sex, and BMI, the size of the effect of fundamental movement skills and physical fitness on energy expenditure and physical activity intensity was moderate (R(2) change between 0.06 and 0.15), with the effect being stronger for high intensity physical activity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nanoscale Subsurface Imaging via Resonant Difference-Frequency Atomic Force Ultrasonic Microscopy

NASA Technical Reports Server (NTRS)

Cantrell, Sean A.; Cantrell, John H.; Lilehei, Peter T.

2007-01-01

A novel scanning probe microscope methodology has been developed that employs an ultrasonic wave launched from the bottom of a sample while the cantilever of an atomic force microscope, driven at a frequency differing from the ultrasonic frequency by the fundamental resonance frequency of the cantilever, engages the sample top surface. The nonlinear mixing of the oscillating cantilever and the ultrasonic wave in the region defined by the cantilever tip-sample surface interaction force generates difference-frequency oscillations at the cantilever fundamental resonance. The resonance-enhanced difference-frequency signals are used to create images of embedded nanoscale features.

Physics architecture

NASA Astrophysics Data System (ADS)

Konopleva, Nelly

2017-03-01

Fundamental physical theory axiomatics is closely connected with methods of experimental measurements. The difference between the theories using global and local symmetries is explained. It is shown that symmetry group localization leads not only to the change of the relativity principle, but to the fundamental modification of experimental programs testing physical theory predictions. It is noticed that any fundamental physical theory must be consistent with the measurement procedures employed for its testing. These ideas are illustrated by events of my biography connected with Yang-Mills theory transformation from an ordinary phenomenological model to a fundamental physical theory based on local symmetry principles like the Einsteinian General Relativity. Baldin position in this situation is demonstrated.

Aligning the Measurement of Microbial Diversity with Macroecological Theory

DOE PAGES

Stegen, James C.; Hurlbert, Allen H.; Bond-Lamberty, Ben; ...

2016-09-23

The number of microbial operational taxonomic units (OTUs) within a community is akin to species richness within plant/animal (‘macrobial’) systems. A large literature documents OTU richness patterns, drawing comparisons to macrobial theory. There is, however, an unrecognized fundamental disconnect between OTU richness and macrobial theory: OTU richness is commonly estimated on a per-individual basis, while macrobial richness is estimated per-area. Furthermore, the range or extent of sampled environmental conditions can strongly influence a study’s outcomes and conclusions, but this is not commonly addressed when studying OTU richness. Here we (i) propose a new sampling approach that estimates OTU richness per-massmore » of soil, which results in strong support for species energy theory, (ii) use data reduction to show how support for niche conservatism emerges when sampling across a restricted range of environmental conditions, and (iii) show how additional insights into drivers of OTU richness can be generated by combining different sampling methods while simultaneously considering patterns that emerge by restricting the range of environmental conditions. We propose that a more rigorous connection between microbial ecology and macrobial theory can be facilitated by exploring how changes in OTU richness units and environmental extent influence outcomes of data analysis. While fundamental differences between microbial and macrobial systems persist (e.g., species concepts), we suggest that closer attention to units and scale provide tangible and immediate improvements to our understanding of the processes governing OTU richness and how those processes relate to drivers of macrobial species richness.« less

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

Stegen, James C.; Hurlbert, Allen H.; Bond-Lamberty, Ben

The number of microbial operational taxonomic units (OTUs) within a community is akin to species richness within plant/animal (‘macrobial’) systems. A large literature documents OTU richness patterns, drawing comparisons to macrobial theory. There is, however, an unrecognized fundamental disconnect between OTU richness and macrobial theory: OTU richness is commonly estimated on a per-individual basis, while macrobial richness is estimated per-area. Furthermore, the range or extent of sampled environmental conditions can strongly influence a study’s outcomes and conclusions, but this is not commonly addressed when studying OTU richness. Here we (i) propose a new sampling approach that estimates OTU richness per-massmore » of soil, which results in strong support for species energy theory, (ii) use data reduction to show how support for niche conservatism emerges when sampling across a restricted range of environmental conditions, and (iii) show how additional insights into drivers of OTU richness can be generated by combining different sampling methods while simultaneously considering patterns that emerge by restricting the range of environmental conditions. We propose that a more rigorous connection between microbial ecology and macrobial theory can be facilitated by exploring how changes in OTU richness units and environmental extent influence outcomes of data analysis. While fundamental differences between microbial and macrobial systems persist (e.g., species concepts), we suggest that closer attention to units and scale provide tangible and immediate improvements to our understanding of the processes governing OTU richness and how those processes relate to drivers of macrobial species richness.« less

Acoustic characteristics of different target vowels during the laryngeal telescopy.

PubMed

Shu, Min-Tsan; Lee, Kuo-Shen; Chang, Chin-Wen; Hsieh, Li-Chun; Yang, Cheng-Chien

2014-10-01

The aim of this study was to investigate the acoustic characteristics of target vowels phonated in normal voice persons while performing laryngeal telescopy. The acoustic characteristics are compared to show the extent of possible difference to speculate their impact on phonation function. Thirty-four male subjects aged 20-39 years with normal voice were included in this study. The target vowels were /i/ and /ɛ/. Recording of voice samples was done under natural phonation and during laryngeal telescopy. The acoustic analysis included the parameters of fundamental frequency, jitter, shimmer and noise-to-harmonic ratio. The sound of a target vowel /ɛ/ was perceived identical in more than 90% of the subjects by the examiner and speech language pathologist during the telescopy. Both /i/ and /ɛ/ sounds showed significant difference when compared with the results under natural phonation. There was no significant difference between /i/ and /ɛ/ during the telescopy. The present study showed that change in target vowels during laryngeal telescopy makes no significant difference in the acoustic characteristics. The results may lead to the speculation that the phonation mechanism was not affected significantly by different vowels during the telescopy. This study may suggest that in the principle of comfortable phonation, introduction of the target vowels /i/ and /ɛ/ is practical. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Plain fundamentals of Fundamental Planes: analytics and algorithms

NASA Astrophysics Data System (ADS)

Sheth, Ravi K.; Bernardi, Mariangela

2012-05-01

Estimates of the coefficients a and b of the Fundamental Plane relation R∝σa Ib depend on whether one minimizes the scatter in the R direction, or orthogonal to the plane. We provide explicit expressions for a and b (and confidence limits) in terms of the covariances between log R, log σ and log I. Our expressions quantify the origin of the difference between the direct, inverse and orthogonal fit coefficients. They also show how to account for correlated errors, how to quantify the difference between the plane in a magnitude-limited survey and one which is volume limited, how to determine whether a scaling relation will be biased when using an apparent magnitude-limited survey, how to remove this bias and why some forms of the z≈ 0 plane appear to be less affected by selection effects, but that this does not imply that they will remain unaffected at high redshift. Finally, they show why, to a good approximation, the three vectors associated with the plane, one orthogonal to and the other two in it, can all be written as simple combinations of a and b. Essentially, this is a consequence of the fact that the distribution of surface brightness is much broader than that of velocity dispersions, and velocity dispersion and surface brightness are only weakly correlated. Why this should be so for galaxies is a fundamental open question about the physics of early-type galaxy formation. We argue that if luminosity evolution is differential, and sizes and velocity dispersions do not evolve, then this is just an accident: velocity dispersion and surface brightness must have been correlated in the past. On the other hand, if the (lack of) correlation is similar to that at the present time, then differential luminosity evolution must have been accompanied by structural evolution. A model in which the luminosities of low-luminosity galaxies evolve more rapidly than do those of higher luminosity galaxies is able to produce the observed decrease in a (by a factor of 2 at z˜ 1) while having b decrease by only about 20 per cent. In such a model, the dynamical mass-to-light ratio is a steeper function of mass at higher z. Our analysis is more generally applicable to any other correlations between three variables: e.g. the colour-magnitude-σ relation, the luminosity and velocity dispersion of a galaxy and the mass of its black hole or the relation between the X-ray luminosity, Sunyaev-Zeldovich decrement and optical richness of a cluster. Furthermore, for completeness, we show how our analysis generalizes further to correlations between more than three variables.

Influence Of Momentum Excess On The Pattern And Dynamics Of Intermediate-Range Stratified Wakes

DTIC Science & Technology

2016-06-01

excess in order to model the fundamental differences between signatures generated by towed and self- propelled bodies in various ocean states. In cases...which can be used on the operational level for developing and improving algorithms for non- acoustic signature prediction and detection. 14. SUBJECT...order to model the fundamental differences between signatures generated by towed and self- propelled bodies in various ocean states. In cases where

Pattern Analyses Reveal Separate Experience-Based Fear Memories in the Human Right Amygdala.

PubMed

Braem, Senne; De Houwer, Jan; Demanet, Jelle; Yuen, Kenneth S L; Kalisch, Raffael; Brass, Marcel

2017-08-23

Learning fear via the experience of contingencies between a conditioned stimulus (CS) and an aversive unconditioned stimulus (US) is often assumed to be fundamentally different from learning fear via instructions. An open question is whether fear-related brain areas respond differently to experienced CS-US contingencies than to merely instructed CS-US contingencies. Here, we contrasted two experimental conditions where subjects were instructed to expect the same CS-US contingencies while only one condition was characterized by prior experience with the CS-US contingency. Using multivoxel pattern analysis of fMRI data, we found CS-related neural activation patterns in the right amygdala (but not in other fear-related regions) that dissociated between whether a CS-US contingency had been instructed and experienced versus merely instructed. A second experiment further corroborated this finding by showing a category-independent neural response to instructed and experienced, but not merely instructed, CS presentations in the human right amygdala. Together, these findings are in line with previous studies showing that verbal fear instructions have a strong impact on both brain and behavior. However, even in the face of fear instructions, the human right amygdala still shows a separable neural pattern response to experience-based fear contingencies. SIGNIFICANCE STATEMENT In our study, we addressed a fundamental problem of the science of human fear learning and memory, namely whether fear learning via experience in humans relies on a neural pathway that can be separated from fear learning via verbal information. Using two new procedures and recent advances in the analysis of brain imaging data, we localized purely experience-based fear processing and memory in the right amygdala, thereby making a direct link between human and animal research. Copyright © 2017 the authors 0270-6474/17/378116-15$15.00/0.

Temporal Tuning of Word- and Face-selective Cortex.

PubMed

Yeatman, Jason D; Norcia, Anthony M

2016-11-01

Sensitivity to temporal change places fundamental limits on object processing in the visual system. An emerging consensus from the behavioral and neuroimaging literature suggests that temporal resolution differs substantially for stimuli of different complexity and for brain areas at different levels of the cortical hierarchy. Here, we used steady-state visually evoked potentials to directly measure three fundamental parameters that characterize the underlying neural response to text and face images: temporal resolution, peak temporal frequency, and response latency. We presented full-screen images of text or a human face, alternated with a scrambled image, at temporal frequencies between 1 and 12 Hz. These images elicited a robust response at the first harmonic that showed differential tuning, scalp topography, and delay for the text and face images. Face-selective responses were maximal at 4 Hz, but text-selective responses, by contrast, were maximal at 1 Hz. The topography of the text image response was strongly left-lateralized at higher stimulation rates, whereas the response to the face image was slightly right-lateralized but nearly bilateral at all frequencies. Both text and face images elicited steady-state activity at more than one apparent latency; we observed early (141-160 msec) and late (>250 msec) text- and face-selective responses. These differences in temporal tuning profiles are likely to reflect differences in the nature of the computations performed by word- and face-selective cortex. Despite the close proximity of word- and face-selective regions on the cortical surface, our measurements demonstrate substantial differences in the temporal dynamics of word- versus face-selective responses.

The Impact of Vocal Hyperfunction on Relative Fundamental Frequency during Voicing Offset and Onset

ERIC Educational Resources Information Center

Stepp, Cara E.; Hillman, Robert E.; Heaton, James T.

2010-01-01

Purpose: This study tested the hypothesis that individuals with vocal hyperfunction would show decreases in relative fundamental frequency (RFF) surrounding a voiceless consonant. Method: This retrospective study of 2 clinical databases used speech samples from 15 control participants and women with hyperfunction-related voice disorders: 82 prior…

Thermodynamics Fundamental Equation of a "Non-Ideal" Rubber Band from Experiments

ERIC Educational Resources Information Center

Ritacco, Herna´n A.; Fortunatti, Juan C.; Devoto, Walter; Ferna´ndez-Miconi, Eugenio; Dominguez, Claudia; Sanchez, Miguel D.

2014-01-01

In this paper, we describe laboratory and classroom exercises designed to obtain the "fundamental" equation of a rubber band by combining experiments and theory. The procedure shows students how classical thermodynamics formalism can help to obtain empirical equations of state by constraining and guiding in the construction of the…

Fundamental problems in provable security and cryptography.

PubMed

Dent, Alexander W

2006-12-15

This paper examines methods for formally proving the security of cryptographic schemes. We show that, despite many years of active research and dozens of significant results, there are fundamental problems which have yet to be solved. We also present a new approach to one of the more controversial aspects of provable security, the random oracle model.

Investigation of the Association Between Motor Stereotypy Behavior With Fundamental Movement Skills, Adaptive Functioning, and Autistic Spectrum Disorder Symptomology in Children With Intellectual Disabilities.

PubMed

Powell, Joanne L; Pringle, Lydia; Greig, Matt

2017-02-01

Motor stereotypy behaviors are patterned, coordinated, repetitive behaviors that are particularly evident in those with an autistic spectrum disorder and intellectual disabilities. The extent to which motor stereotypy behavior severity is associated with motor skills and maladaptive behavior, measures of adaptive functioning, along with fundamental movement skills and degree of autistic spectrum disorder symptomology is assessed in this preliminary report. Twelve participants, aged 7 to 16 years, with a reported motor stereotypy behavior and either mild or severe intellectual disability comprising developmental or global delay took part in the study. Spearman rho correlational analysis showed that severity of motor stereotypy behavior was significantly positively correlated with autistic spectrum disorder symptomology ( P = .008) and maladaptive behavior ( P = .008) but not fundamental movement skills ( P > .05). An increase in fundamental movement skills score was associated with a decrease in autistic spectrum disorder symptomology ( P = .01) and an increase in motor skills ( P = .002). This study provides evidence showing a significant relationship between motor stereotypy behavior severity with degree of autistic spectrum disorder symptomology and maladaptive behavior.

Novel Methods in Disease Biogeography: A Case Study with Heterosporosis

PubMed Central

Escobar, Luis E.; Qiao, Huijie; Lee, Christine; Phelps, Nicholas B. D.

2017-01-01

Disease biogeography is currently a promising field to complement epidemiology, and ecological niche modeling theory and methods are a key component. Therefore, applying the concepts and tools from ecological niche modeling to disease biogeography and epidemiology will provide biologically sound and analytically robust descriptive and predictive analyses of disease distributions. As a case study, we explored the ecologically important fish disease Heterosporosis, a relatively poorly understood disease caused by the intracellular microsporidian parasite Heterosporis sutherlandae. We explored two novel ecological niche modeling methods, the minimum-volume ellipsoid (MVE) and the Marble algorithm, which were used to reconstruct the fundamental and the realized ecological niche of H. sutherlandae, respectively. Additionally, we assessed how the management of occurrence reports can impact the output of the models. Ecological niche models were able to reconstruct a proxy of the fundamental and realized niche for this aquatic parasite, identifying specific areas suitable for Heterosporosis. We found that the conceptual and methodological advances in ecological niche modeling provide accessible tools to update the current practices of spatial epidemiology. However, careful data curation and a detailed understanding of the algorithm employed are critical for a clear definition of the assumptions implicit in the modeling process and to ensure biologically sound forecasts. In this paper, we show how sensitive MVE is to the input data, while Marble algorithm may provide detailed forecasts with a minimum of parameters. We showed that exploring algorithms of different natures such as environmental clusters, climatic envelopes, and logistic regressions (e.g., Marble, MVE, and Maxent) provide different scenarios of potential distribution. Thus, no single algorithm should be used for disease mapping. Instead, different algorithms should be employed for a more informed and complete understanding of the pathogen or parasite in question. PMID:28770215

Fundamentals of fluid sealing

NASA Technical Reports Server (NTRS)

Zuk, J.

1976-01-01

The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

Local pH at the surface of hen egg white lysozyme

NASA Astrophysics Data System (ADS)

Otosu, Takuhiro; Kobayashi, Kaito; Yamaguchi, Shoichi

2018-02-01

The microenvironment at the surface of hen-egg-white lysozyme (HEWL) was examined by analyzing the change in pKa of fluorescein isothiocyanate (FITC) upon binding to the N-terminus of HEWL. The result showed that the local pH at the HEWL surface is higher than the bulk pH. Furthermore, the data showed that the difference between the local and bulk pH becomes larger with decreasing pH, suggesting HEWL repels more protons at lower pH. Because the local pH affects the protonation states of functional amino-acids at the protein surface, the results provide the fundamental insight into the microenvironment at the protein surface.

Conformational Rigidity and Protein Dynamics at Distinct Timescales Regulate PTP1B Activity and Allostery.

PubMed

Choy, Meng S; Li, Yang; Machado, Luciana E S F; Kunze, Micha B A; Connors, Christopher R; Wei, Xingyu; Lindorff-Larsen, Kresten; Page, Rebecca; Peti, Wolfgang

2017-02-16

Protein function originates from a cooperation of structural rigidity, dynamics at different timescales, and allostery. However, how these three pillars of protein function are integrated is still only poorly understood. Here we show how these pillars are connected in Protein Tyrosine Phosphatase 1B (PTP1B), a drug target for diabetes and cancer that catalyzes the dephosphorylation of numerous substrates in essential signaling pathways. By combining new experimental and computational data on WT-PTP1B and ≥10 PTP1B variants in multiple states, we discovered a fundamental and evolutionarily conserved CH/π switch that is critical for positioning the catalytically important WPD loop. Furthermore, our data show that PTP1B uses conformational and dynamic allostery to regulate its activity. This shows that both conformational rigidity and dynamics are essential for controlling protein activity. This connection between rigidity and dynamics at different timescales is likely a hallmark of all enzyme function. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of the Rheology of Bauxite Residue Suspensions

NASA Astrophysics Data System (ADS)

Pashias, N.; Boger, D. V.; Summers, J.; Glenister, D. J.

The paper presents an overview on the rheology of bauxite residue suspensions. Comparative viscosity and yield stress data are presented for bauxite residues generated in Australia, Jamaica, Surinam, and the USA. A yield stress for optimum dry disposal is specified as is the concentration for minimum energy consumption for the pumping of the four different materials. The data show that bauxite residues can be characterised at two structural states: the initial and the equilibrium or time-independent state. Data can be collected and reproduced for different muds providing there is an understanding of the time dependent nature of the material. The four red mud samples obtained from around the world have been characterised in both the initial and final equilibrium state. A comparison shows that after the course particle fraction has been removed the US, Surinam, and three samples from Western Australia all show similar rheological characteristics in the reduced structural state. A fundamental understanding of the basic rheology of bauxite residue is necessary for establishing an optimal waste disposal strategy.

Low-latitude variability of ice cloud properties and cloud thermodynamic phase observed by the Atmospheric Infrared Sounder (AIRS)

NASA Astrophysics Data System (ADS)

Kahn, B. H.; Yue, Q.; Davis, S. M.; Fetzer, E. J.; Schreier, M. M.; Tian, B.; Wong, S.

2016-12-01

We will quantify the time and space dependence of ice cloud effective radius (CER), optical thickness (COT), cloud top temperature (CTT), effective cloud fraction (ECF), and cloud thermodynamic phase (ice, liquid, or unknown) with the Version 6 Atmospheric Infrared Sounder (AIRS) satellite observational data set from September 2002 until present. We show that cloud frequency, CTT, COT, and ECF have substantially different responses to ENSO variations. Large-scale changes in ice CER are also observed with a several micron tropics-wide increase during the 2015-2016 El Niño and similar decreases during the La Niña phase. We show that the ice CER variations reflect fundamental changes in the spatial distributions and relative frequencies of different ice cloud types. Lastly, the high spatial and temporal resolution variability of the cloud fields are explored and we show that these data capture a multitude of convectively coupled tropical waves such as Kelvin, westward and eastward intertio-gravity, equatorial Rossby, and mixed Rossby-gravity waves.

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

Binder, Tobias; Covi, Laura; Kamada, Ayuki

Dark Matter (DM) models providing possible alternative solutions to the small-scale crisis of the standard cosmology are nowadays of growing interest. We consider DM interacting with light hidden fermions via well-motivated fundamental operators showing the resultant matter power spectrum is suppressed on subgalactic scales within a plausible parameter region. Our basic description of the evolution of cosmological perturbations relies on a fully consistent first principles derivation of a perturbed Fokker-Planck type equation, generalizing existing literature. The cosmological perturbation of the Fokker-Planck equation is presented for the first time in two different gauges, where the results transform into each other accordingmore » to the rules of gauge transformation. Furthermore, our focus lies on a derivation of a broadly applicable and easily computable collision term showing important phenomenological differences to other existing approximations. As one of the main results and concerning the small-scale crisis, we show the equal importance of vector and scalar boson mediated interactions between the DM and the light fermions.« less

Acoustic analysis of speech variables during depression and after improvement.

PubMed

Nilsonne, A

1987-09-01

Speech recordings were made of 16 depressed patients during depression and after clinical improvement. The recordings were analyzed using a computer program which extracts acoustic parameters from the fundamental frequency contour of the voice. The percent pause time, the standard deviation of the voice fundamental frequency distribution, the standard deviation of the rate of change of the voice fundamental frequency and the average speed of voice change were found to correlate to the clinical state of the patient. The mean fundamental frequency, the total reading time and the average rate of change of the voice fundamental frequency did not differ between the depressed and the improved group. The acoustic measures were more strongly correlated to the clinical state of the patient as measured by global depression scores than to single depressive symptoms such as retardation or agitation.

Fundamentals of Chemical Processes.

ERIC Educational Resources Information Center

Moser, William R.

1985-01-01

Describes a course that provides students with a fundamental understanding of the chemical, catalytic, and engineering sciences related to the chemical reactions taking place in a variety of reactors of different configurations. Also describes the eight major lecture topics, course examinations, and term papers. The course schedule is included.…

Comparison of fundamental and simulative test methods for evaluating permanent deformation of hot mix asphalt

DOT National Transportation Integrated Search

2002-10-01

Rutting has long been a problem in hot mix asphalt (HMA) pavement. Through the years, researchers have used different kinds of fundamental and simulative test methods to estimate the rutting performance of HMA. It has been recognized that most fundam...

Unraveling hidden order in the dynamics of developed and emerging markets.

PubMed

Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

2014-01-01

The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development.

Unraveling Hidden Order in the Dynamics of Developed and Emerging Markets

PubMed Central

Berman, Yonatan; Shapira, Yoash; Ben-Jacob, Eshel

2014-01-01

The characterization of asset price returns is an important subject in modern finance. Traditionally, the dynamics of stock returns are assumed to lack any temporal order. Here we present an analysis of the autocovariance of stock market indices and unravel temporal order in several major stock markets. We also demonstrate a fundamental difference between developed and emerging markets in the past decade - emerging markets are marked by positive order in contrast to developed markets whose dynamics are marked by weakly negative order. In addition, the reaction to financial crises was found to be reversed among developed and emerging markets, presenting large positive/negative autocovariance spikes following the onset of these crises. Notably, the Chinese market shows neutral or no order while being regarded as an emerging market. These findings show that despite the coupling between international markets and global trading, major differences exist between different markets, and demonstrate that the autocovariance of markets is correlated with their stability, as well as with their state of development. PMID:25383630

Effects of forward velocity and acoustic treatment on inlet fan noise

NASA Technical Reports Server (NTRS)

Feiler, C. E.; Merriman, J. E.

1974-01-01

Flyover and static noise data from several engines are presented that show inlet fan noise measured in flight can be lower than that projected from static tests for some engines. The differences between flight and static measurements appear greatest when the fan fundamental tone due to rotor-stator interaction or to the rotor-alone field is below cutoff. Data from engine and fan tests involving inlet treatment on the walls only are presented that show the attenuation from this treatment is substantially larger than expected from previous theories or flow duct experience. Data showing noise shielding effects due to the location of the engine on the airplane are also presented. These observations suggest that multiringed inlets may not be necessary to achieve the desired noise reduction in many applications.

Two-Way Communication with a Single Quantum Particle.

PubMed

Del Santo, Flavio; Dakić, Borivoje

2018-02-09

In this Letter we show that communication when restricted to a single information carrier (i.e., single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass this limitation. We show that communication bounded to the exchange of a single quantum particle (in superposition of different spatial locations) can result in "two-way signaling," which is impossible in classical physics. We quantify the discrepancy between classical and quantum scenarios by the probability of winning a game played by distant players. We generalize our result to an arbitrary number of parties and we show that the probability of success is asymptotically decreasing to zero as the number of parties grows, for all classical strategies. In contrast, quantum strategy allows players to win the game with certainty.

Two-Way Communication with a Single Quantum Particle

NASA Astrophysics Data System (ADS)

Del Santo, Flavio; Dakić, Borivoje

2018-02-01

In this Letter we show that communication when restricted to a single information carrier (i.e., single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass this limitation. We show that communication bounded to the exchange of a single quantum particle (in superposition of different spatial locations) can result in "two-way signaling," which is impossible in classical physics. We quantify the discrepancy between classical and quantum scenarios by the probability of winning a game played by distant players. We generalize our result to an arbitrary number of parties and we show that the probability of success is asymptotically decreasing to zero as the number of parties grows, for all classical strategies. In contrast, quantum strategy allows players to win the game with certainty.

Organometallic neptunium(III) complexes.

PubMed

Dutkiewicz, Michał S; Farnaby, Joy H; Apostolidis, Christos; Colineau, Eric; Walter, Olaf; Magnani, Nicola; Gardiner, Michael G; Love, Jason B; Kaltsoyannis, Nikolas; Caciuffo, Roberto; Arnold, Polly L

2016-08-01

Studies of transuranic organometallic complexes provide a particularly valuable insight into covalent contributions to the metal-ligand bonding, in which the subtle differences between the transuranium actinide ions and their lighter lanthanide counterparts are of fundamental importance for the effective remediation of nuclear waste. Unlike the organometallic chemistry of uranium, which has focused strongly on U(III) and has seen some spectacular advances, that of the transuranics is significantly technically more challenging and has remained dormant. In the case of neptunium, it is limited mainly to Np(IV). Here we report the synthesis of three new Np(III) organometallic compounds and the characterization of their molecular and electronic structures. These studies suggest that Np(III) complexes could act as single-molecule magnets, and that the lower oxidation state of Np(II) is chemically accessible. In comparison with lanthanide analogues, significant d- and f-electron contributions to key Np(III) orbitals are observed, which shows that fundamental neptunium organometallic chemistry can provide new insights into the behaviour of f-elements.

Organometallic neptunium(III) complexes

NASA Astrophysics Data System (ADS)

Dutkiewicz, Michał S.; Farnaby, Joy H.; Apostolidis, Christos; Colineau, Eric; Walter, Olaf; Magnani, Nicola; Gardiner, Michael G.; Love, Jason B.; Kaltsoyannis, Nikolas; Caciuffo, Roberto; Arnold, Polly L.

2016-08-01

Studies of transuranic organometallic complexes provide a particularly valuable insight into covalent contributions to the metal-ligand bonding, in which the subtle differences between the transuranium actinide ions and their lighter lanthanide counterparts are of fundamental importance for the effective remediation of nuclear waste. Unlike the organometallic chemistry of uranium, which has focused strongly on UIII and has seen some spectacular advances, that of the transuranics is significantly technically more challenging and has remained dormant. In the case of neptunium, it is limited mainly to NpIV. Here we report the synthesis of three new NpIII organometallic compounds and the characterization of their molecular and electronic structures. These studies suggest that NpIII complexes could act as single-molecule magnets, and that the lower oxidation state of NpII is chemically accessible. In comparison with lanthanide analogues, significant d- and f-electron contributions to key NpIII orbitals are observed, which shows that fundamental neptunium organometallic chemistry can provide new insights into the behaviour of f-elements.

Near- and far-field investigation of dark and bright higher order resonances in square loop elements at mid-infrared wavelengths.

PubMed

Tucker, Eric; D'Archangel, Jeffrey; Boreman, Glenn

2017-03-06

Three different size gold square loop structures were fabricated as arrays on ZnS over a ground plane and designed to have absorptive fundamental, second order, and third order resonances at a wavelength of 10.6 µm and 60° off-normal. The angular dependent far-field spectral absorptivity was investigated over the mid-infrared for each size loop array. It was found that the second order modes were dark at normal incidence, but became excited at off-normal incidence, which is consistent with previous work for similar geometry structures. Furthermore, near-field measurements and simulations at a wavelength of 10.6 µm and 60° off-normal showed that the second order mode (quadrupolar) of the medium size loop yielded a near-field response similar in magnitude to the fundamental mode (dipolar) of the small size loop, which can be important for sensing related applications where both strong near-field enhancement and more uniform or less localized field is beneficial.

Low-Reynolds-number swimming at pycnoclines.

PubMed

Doostmohammadi, Amin; Stocker, Roman; Ardekani, Arezoo M

2012-03-06

Microorganisms play pivotal functions in the trophic dynamics and biogeochemistry of aquatic ecosystems. Their concentrations and activities often peak at localized hotspots, an important example of which are pycnoclines, where water density increases sharply with depth due to gradients in temperature or salinity. At pycnoclines organisms are exposed to different environmental conditions compared to the bulk water column, including reduced turbulence, slow mass transfer, and high particle and predator concentrations. Here we show that, at an even more fundamental level, the density stratification itself can affect microbial ecology at pycnoclines, by quenching the flow signature, increasing the energetic expenditure, and stifling the nutrient uptake of motile organisms. We demonstrate this through numerical simulations of an archetypal low-Reynolds-number swimmer, the "squirmer." We identify the Richardson number--the ratio of buoyancy forces to viscous forces--as the fundamental parameter that quantifies the effects of stratification. These results demonstrate an unexpected effect of buoyancy on low-Reynolds-number swimming, potentially affecting a broad range of abundant organisms living at pycnoclines in oceans and lakes.

Alarm signals of the Sichuan sika deer Cervus nippon sichuanicus.

PubMed

Yang, Chengzhong; Xiao, Zhen; Guo, Yanshu; Xiong, Yuanqing; Zhang, Xiuyue; Yue, Bisong

2012-07-01

Sichuan sika deer (Cervus nippon sichuanicus) is an endangered and endemic subspecies of sika deer to Sichuan Province, China. According to our observations in the wild, the Sichuan sika deer makes alarm signals in the presence of actual or potential predators. In order to test the variation of the rhythmic alarm calls in some sex/age classes and different risk contexts, we recorded alarm calls of Sichuan sika deer from 2 October to 30 November 2008 and from 4 April to 5 September 2009 in the Tiebu Nature Reserve, Zoige County, Sichuan Province, China, and made acoustic analysis of these alarm calls. The results showed that the fundamental frequencies of alarm signals of Sichuan sika deer tended to decrease with age, and were significantly higher for females than for males. Duration tended to increase with age, and was significantly longer for males than for females. The fundamental frequencies and duration of alarm calls in adults were significantly higher and shorter respectively in high-risk than in moderate-risk contexts.

Using Inspiration from Synaptic Plasticity Rules to Optimize Traffic Flow in Distributed Engineered Networks.

PubMed

Suen, Jonathan Y; Navlakha, Saket

2017-05-01

Controlling the flow and routing of data is a fundamental problem in many distributed networks, including transportation systems, integrated circuits, and the Internet. In the brain, synaptic plasticity rules have been discovered that regulate network activity in response to environmental inputs, which enable circuits to be stable yet flexible. Here, we develop a new neuro-inspired model for network flow control that depends only on modifying edge weights in an activity-dependent manner. We show how two fundamental plasticity rules, long-term potentiation and long-term depression, can be cast as a distributed gradient descent algorithm for regulating traffic flow in engineered networks. We then characterize, both by simulation and analytically, how different forms of edge-weight-update rules affect network routing efficiency and robustness. We find a close correspondence between certain classes of synaptic weight update rules derived experimentally in the brain and rules commonly used in engineering, suggesting common principles to both.

Effects of iterative learning based signal control strategies on macroscopic fundamental diagrams of urban road networks

NASA Astrophysics Data System (ADS)

Yan, Fei; Tian, Fuli; Shi, Zhongke

2016-10-01

Urban traffic flows are inherently repeated on a daily or weekly basis. This repeatability can help improve the traffic conditions if it is used properly by the control system. In this paper, we propose a novel iterative learning control (ILC) strategy for traffic signals of urban road networks using the repeatability feature of traffic flow. To improve the control robustness, the ILC strategy is further integrated with an error feedback control law in a complementary manner. Theoretical analysis indicates that the ILC-based traffic signal control methods can guarantee the asymptotic learning convergence, despite the presence of modeling uncertainties and exogenous disturbances. Finally, the impacts of the ILC-based signal control strategies on the network macroscopic fundamental diagram (MFD) are examined. The results show that the proposed ILC-based control strategies can homogenously distribute the network accumulation by controlling the vehicle numbers in each link to the desired levels under different traffic demands, which can result in the network with high capacity and mobility.

Fundamental frequencies and resonances from eccentric and precessing binary black hole inspirals

NASA Astrophysics Data System (ADS)

Lewis, Adam G. M.; Zimmerman, Aaron; Pfeiffer, Harald P.

2017-06-01

Binary black holes which are both eccentric and undergo precession remain unexplored in numerical simulations. We present simulations of such systems which cover about 50 orbits at comparatively high mass ratios 5 and 7. The configurations correspond to the generic motion of a nonspinning body in a Kerr spacetime, and are chosen to study the transition from finite mass-ratio inspirals to point particle motion in Kerr. We develop techniques to extract analogs of the three fundamental frequencies of Kerr geodesics, compare our frequencies to those of Kerr, and show that the differences are consistent with self-force corrections entering at first order in mass ratio. This analysis also locates orbital resonances where the ratios of our frequencies take rational values. At the considered mass ratios, the binaries pass through resonances in one to two resonant cycles, and we find no discernible effects on the orbital evolution. We also compute the decay of eccentricity during the inspiral and find good agreement with the leading order post-Newtonian prediction.

Global Analysis of Perovskite Photophysics Reveals Importance of Geminate Pathways

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

Manger, Lydia H.; Rowley, Matthew B.; Fu, Yongping

Hybrid organic-inorganic perovskites demonstrate desirable photophysical behaviors and promising applications from efficient photovoltaics to lasing, but the fundamental nature of excited state species is still under debate. We also collected time-resolved photoluminescence of single-crystal nanoplates of methylammonium lead iodide perovskite (MAPbI3), with excitation over a range of fluences and repetition rates, to provide a more complete photophysical picture. A fundamentally different way of simulating the photophysics is developed that relies on unnormalized decays, global analysis over a large array of conditions, and inclusion of steady-state behavior; these details are critical to capturing observed behaviors. These additional constraints require inclusion ofmore » spatially-correlated pairs, along with free carriers and traps, demonstrating the importance of our comprehensive analysis. Modeling geminate and non-geminate pathways shows geminate processes are dominant at high carrier densities and early times. This combination of data and simulation provides a detailed picture of perovskite photophysics across multiple excitation regimes that was not previously available.« less

Global Analysis of Perovskite Photophysics Reveals Importance of Geminate Pathways

DOE PAGES

Manger, Lydia H.; Rowley, Matthew B.; Fu, Yongping; ...

2016-12-20

Hybrid organic-inorganic perovskites demonstrate desirable photophysical behaviors and promising applications from efficient photovoltaics to lasing, but the fundamental nature of excited state species is still under debate. We also collected time-resolved photoluminescence of single-crystal nanoplates of methylammonium lead iodide perovskite (MAPbI3), with excitation over a range of fluences and repetition rates, to provide a more complete photophysical picture. A fundamentally different way of simulating the photophysics is developed that relies on unnormalized decays, global analysis over a large array of conditions, and inclusion of steady-state behavior; these details are critical to capturing observed behaviors. These additional constraints require inclusion ofmore » spatially-correlated pairs, along with free carriers and traps, demonstrating the importance of our comprehensive analysis. Modeling geminate and non-geminate pathways shows geminate processes are dominant at high carrier densities and early times. This combination of data and simulation provides a detailed picture of perovskite photophysics across multiple excitation regimes that was not previously available.« less

Giant moving vortex mass in thick magnetic nanodots

PubMed Central

Guslienko, K. Y.; Kakazei, G. N.; Ding, J.; Liu, X. M.; Adeyeye, A. O.

2015-01-01

Magnetic vortex is one of the simplest topologically non-trivial textures in condensed matter physics. It is the ground state of submicron magnetic elements (dots) of different shapes: cylindrical, square etc. So far, the vast majority of the vortex dynamics studies were focused on thin dots with thickness 5–50 nm and only uniform across the thickness vortex excitation modes were observed. Here we explore the fundamental vortex mode in relatively thick (50–100 nm) dots using broadband ferromagnetic resonance and show that dimensionality increase leads to qualitatively new excitation spectra. We demonstrate that the fundamental mode frequency cannot be explained without introducing a giant vortex mass, which is a result of the vortex distortion due to interaction with spin waves. The vortex mass depends on the system geometry and is non-local because of important role of the dipolar interaction. The mass is rather small for thin dots. However, its importance increases drastically with the dot thickness increasing. PMID:26355430

Giant moving vortex mass in thick magnetic nanodots.

PubMed

Guslienko, K Y; Kakazei, G N; Ding, J; Liu, X M; Adeyeye, A O

2015-09-10

Magnetic vortex is one of the simplest topologically non-trivial textures in condensed matter physics. It is the ground state of submicron magnetic elements (dots) of different shapes: cylindrical, square etc. So far, the vast majority of the vortex dynamics studies were focused on thin dots with thickness 5-50 nm and only uniform across the thickness vortex excitation modes were observed. Here we explore the fundamental vortex mode in relatively thick (50-100 nm) dots using broadband ferromagnetic resonance and show that dimensionality increase leads to qualitatively new excitation spectra. We demonstrate that the fundamental mode frequency cannot be explained without introducing a giant vortex mass, which is a result of the vortex distortion due to interaction with spin waves. The vortex mass depends on the system geometry and is non-local because of important role of the dipolar interaction. The mass is rather small for thin dots. However, its importance increases drastically with the dot thickness increasing.

Theoretical Study of tip apex electronic structure in Scanning Tunneling Microscope

NASA Astrophysics Data System (ADS)

Choi, Heesung; Huang, Min; Randall, John; Cho, Kyeongjae

2011-03-01

Scanning Tunneling Microscope (STM) has been widely used to explore diverse surface properties with an atomic resolution, and STM tip has played a critical role in controlling surface structures. However, detailed information of atomic and electronic structure of STM tip and the fundamental understanding of STM images are still incomplete. Therefore, it is important to develop a comprehensive understanding of the electronic structure of STM tip. We have studied the atomic and electronic structures of STM tip with various transition metals (TMs) by DFT method. The d-electrons of TM tip apex atoms show different orbital states near the Fermi level. We will present comprehensive data of STM tips from our DFT calculation. Verified quantification of the tip electronic structures will lead to fundamental understanding of STM tip structure-property relationship. This work is supported by the DARPA TBN Program and the Texas ETF. DARPA Tip Based Nanofabrication Program and the Emerging Technology Fund of the State of Texas.

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

PubMed

Kashuba, Corinna M; Benson, James D; Critser, John K

2014-04-01

The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. Copyright © 2014 Elsevier Inc. All rights reserved.

Culturomics meets random fractal theory: insights into long-range correlations of social and natural phenomena over the past two centuries

PubMed Central

Gao, Jianbo; Hu, Jing; Mao, Xiang; Perc, Matjaž

2012-01-01

Culturomics was recently introduced as the application of high-throughput data collection and analysis to the study of human culture. Here, we make use of these data by investigating fluctuations in yearly usage frequencies of specific words that describe social and natural phenomena, as derived from books that were published over the course of the past two centuries. We show that the determination of the Hurst parameter by means of fractal analysis provides fundamental insights into the nature of long-range correlations contained in the culturomic trajectories, and by doing so offers new interpretations as to what might be the main driving forces behind the examined phenomena. Quite remarkably, we find that social and natural phenomena are governed by fundamentally different processes. While natural phenomena have properties that are typical for processes with persistent long-range correlations, social phenomena are better described as non-stationary, on–off intermittent or Lévy walk processes. PMID:22337632

[Effects of fundamental frequency and speech rate on impression formation].

PubMed

Uchida, Teruhisa; Nakaune, Naoko

2004-12-01

This study investigated the systematic relationship between nonverbal features of speech and personality trait ratings of the speaker. In Study 1, fundamental frequency (F0) in original speech was converted into five levels from 64% to 156.25%. Then 132 undergraduates rated each of the converted speeches in terms of personality traits. In Study 2 134 undergraduates similarly rated the speech stimuli, which had five speech rate levels as well as two F0 levels. Results showed that listener ratings along Big Five dimensions were mostly independent. Each dimension had a slightly different change profile over the five levels of F0 and speech rate. A quadratic regression equation provided a good approximation for each rating as a function of F0 or speech rate. The quadratic regression equations put together would provide us with a rough estimate of personality trait impression as a function of prosodic features. The functional relationship among F0, speech rate, and trait ratings was shown as a curved surface in the three-dimensional space.

Early type galaxies: Mapping out the two-dimensional space of galaxy star formation histories

NASA Astrophysics Data System (ADS)

Graves, Genevieve J.

Early type galaxies form a multi-parameter family, as evidenced by the two- dimensional (2-D) Fundamental Plane relationship. However, their star formation histories are often treated as a one-dimensional mass sequence. This dissertation presents a systematic study of the relationship between the multi- parameter structural properties of early type galaxies and their star formation histoires. We demonstrate that the stellar populations of early type galaxies span a 2-D space, which means that their star formation histories form a two- parameter family. This 2-D family is then mapped onto several familiar early type galaxy scaling relations, including the color-magnitude relation, the Fundamental Plane, and a cross-section through the Fundamental Plane. We find that the stellar population properties, and therefore the star formation histories of early type galaxies depend most strongly on galaxy velocity dispersion (s), rather than on luminosity ( L ), stellar mass ( M [low *] ), or dynamical mass ( M dyn ). Interestingly, stellar populations are independent of the radius ( R e ) of the galaxies. At fixed s, they show correlated residuals through the thickness of the Fundamental Plane (FP) in the surface-brightness ( I e ) dimension, such that low-surface-brightness galaxies are older, less metal-enriched, and more enhanced in Mg relative to Fe than their counterparts at the same s and R e on the FP midplane. Similarly, high- surface-brightness galaxies are younger, more metal-rich, and less Mg-enhanced than their counterparts on the FP midplane. These differences suggest that the duration of star formation varies through the thickness of the FP. If the dynamical mass-to-light ratios of early type galaxies ( M dyn /L ) were constant for all such galaxies, the FP would be equivalent to the plane predicted by the virial relation. However, the observed FP does not exactly match the virial plane. The FP is tilted from the virial plane, indicating that M dyn /L varies systematically across it. Furthermore the FP relation, although relatively tight, shows more scatter in surface brightness (at fixed s and R e ) than is predicted by observational errors. This finite thickness indicates that M dyn /L also varies at a fixed point on the FP. We observe that the stellar populations of early type galaxies vary through the thickness of the FP. These differences translate into variations in the stellar mass-to-light ratio ( M [low *] /L ) that contribute to both the tilt and the thickness of the FP. However, the mass-to-light variations due to stellar population differences are too small to explain either the tilt of the FP or its thickness. This implies that the tilt and thickness of the FP are driven by systematic variations in either the central dark matter fraction in galaxies or in the IMF with which they form stars. Furthermore, because star formation histories can be mapped onto locations in FP-space, the variations in central dark matter fraction or IMF differences must be correlated with differences in the galaxies' star formation histories.

Different evolution dynamics of vector solitons depending on their polarization states

NASA Astrophysics Data System (ADS)

Chen, Wei-Cheng; Chen, Guo-Jie

2014-03-01

There are three types of temporal evolution dynamics of vector solitons observed in a ring fiber laser with a semiconductor saturable absorption mirror (SESAM) as a mode-locker. It is found that the polarization property of vector solitons is an important factor for achieving different evolution dynamics. The vector soliton with a uniform polarization state across the whole pulse profile and zero polarization extinction ratio operates at a fundamental repetition rate with a single pulse profile. The elliptically polarized vector soliton with a larger polarization extinction ratio exhibits a harmonic pulse train. The soliton bunching with multi-peak structures exists between the above two states and shows elliptical polarization with a small polarization extinction ratio.

HYDRODYNAMIC SIMULATION OF THE UPPER POTOMAC ESTUARY.

USGS Publications Warehouse

Schaffranck, Raymond W.

1986-01-01

Hydrodynamics of the upper extent of the Potomac Estuary between Indian Head and Morgantown, Md. , are simulated using a two-dimensional model. The model computes water-surface elevations and depth-averaged velocities by numerically integrating finite-difference forms of the equations of mass and momentum conservation using the alternating direction implicit method. The fundamental, non-linear, unsteady-flow equations, upon which the model is formulated, include additional terms to account for Coriolis acceleration and meteorological influences. Preliminary model/prototype data comparisons show agreement to within 9% for tidal flow volumes and phase differences within the measured-data-recording interval. Use of the model to investigate the hydrodynamics and certain aspects of transport within this Potomac Estuary reach is demonstrated. Refs.

Bound and free waves in non-collinear second harmonic generation.

PubMed

Larciprete, M C; Bovino, F A; Belardini, A; Sibilia, C; Bertolotti, M

2009-09-14

We analyze the relationship between the bound and the free waves in the noncollinear SHG scheme, along with the vectorial conservation law for the different components arising when there are two pump beams impinging on the sample with two different incidence angles. The generated power is systematically investigated, by varying the polarization state of both fundamental beams, while absorption is included via the Herman and Hayden correction terms. The theoretical simulations, obtained for samples which are some coherence length thick show that the resulting polarization mapping is an useful tool to put in evidence the interference between bound and free waves, as well as the effect of absorption on the interference pattern.

Biologically inspired emotion recognition from speech

NASA Astrophysics Data System (ADS)

Caponetti, Laura; Buscicchio, Cosimo Alessandro; Castellano, Giovanna

2011-12-01

Emotion recognition has become a fundamental task in human-computer interaction systems. In this article, we propose an emotion recognition approach based on biologically inspired methods. Specifically, emotion classification is performed using a long short-term memory (LSTM) recurrent neural network which is able to recognize long-range dependencies between successive temporal patterns. We propose to represent data using features derived from two different models: mel-frequency cepstral coefficients (MFCC) and the Lyon cochlear model. In the experimental phase, results obtained from the LSTM network and the two different feature sets are compared, showing that features derived from the Lyon cochlear model give better recognition results in comparison with those obtained with the traditional MFCC representation.

Growth and nonlinear response of driven water bells

NASA Astrophysics Data System (ADS)

Kolinski, John M.; Aharoni, Hillel; Fineberg, Jay; Sharon, Eran

2017-04-01

A water bell forms when a fluid jet impacts upon a target and separates into a two-dimensional sheet. Depending on the angle of separation from the target, the sheet can curve into a variety of different geometries. We show analytically that harmonic perturbations of water bells have linear wave solutions with geometry-dependent growth. We test the predictions of this model experimentally with a custom target system, and observe growth in agreement with the model below a critical forcing amplitude. Once the critical forcing amplitude is exceeded, a nonlinear transcritical bifurcation occurs; the response amplitude increases linearly with increasing forcing amplitude, albeit with a fundamentally different spatial form, and distinct nodes appear in the amplitude envelope.

On-chip optical diode based on silicon photonic crystal heterojunctions.

PubMed

Wang, Chen; Zhou, Chang-Zhu; Li, Zhi-Yuan

2011-12-19

Optical isolation is a long pursued object with fundamental difficulty in integrated photonics. As a step towards this goal, we demonstrate the design, fabrication, and characterization of on-chip wavelength-scale optical diodes that are made from the heterojunction between two different silicon two-dimensional square-lattice photonic crystal slabs with directional bandgap mismatch and different mode transitions. The measured transmission spectra show considerable unidirectional transmission behavior, in good agreement with numerical simulations. The experimental realization of on-chip optical diodes with wavelength-scale size using all-dielectric, passive, and linear silicon photonic crystal structures may help to construct on-chip optical logical devices without nonlinearity or magnetism, and would open up a road towards photonic computers.

Response to Comment on "Water harvesting from air with metal-organic frameworks powered by natural sunlight".

PubMed

Kim, Hyunho; Rao, Sameer R; Narayanan, Shankar; Kapustin, Eugene A; Yang, Sungwoo; Furukawa, Hiroyasu; Umans, Ari S; Yaghi, Omar M; Wang, Evelyn N

2017-12-01

In their comment, Bui et al argue that the approach we described in our report is vastly inferior in efficiency to alternative off-the-shelf technologies. Their conclusion is invalid, as they compare efficiencies in completely different operating conditions. Here, using heat transfer and thermodynamics principles, we show how Bui et al 's conclusions about the efficiencies of off-the-shelf technologies are fundamentally flawed and inaccurate for the operating conditions described in our study. Copyright © 2017, American Association for the Advancement of Science.

Structure functions in decomposing CuRh systems

NASA Astrophysics Data System (ADS)

Prem, M.; Blaschko, O.; Rosta, L.

1997-02-01

The time evolution of a CuRh alloy quenched within the miscibility gap is investigated by small and wide angle neutron scattering techniques. Near fundamental Bragg reflections diffuse satellites arising from a lattice parameter modulation induced by the precipitation pattern are investigated. The results show that in CuRh the precipitation morphology and its time evolution are quite different from decomposition characteristics recently observed in the system AuPt. The results are discussed and related to the larger lattice misfit present in CuRh in comparison to AuPt.

Acoustics-turbulence interaction

NASA Technical Reports Server (NTRS)

Hussain, A. K. M. F.; Zaman, K. B. M. O.

1977-01-01

An investigation of the instability frequency was undertaken. Measurements revealed that the hot wire probe induces and sustains stable upstream oscillation of the free shear layer. The characteristics of the free shear layer tone are found to be different from the slit jet wedge edgetone phenomenon. The shear tone induced by a plane wedge in a plane free shear layer was then examined in order to further document the phenomenon. The eigenvalues and eigenfunctions of the tone fundamental show agreement with the spatial stability theory. A comprehensive summary of the results is also included.

Coherence protection in coupled quantum systems

NASA Astrophysics Data System (ADS)

Cammack, H. M.; Kirton, P.; Stace, T. M.; Eastham, P. R.; Keeling, J.; Lovett, B. W.

2018-02-01

The interaction of a quantum system with its environment causes decoherence, setting a fundamental limit on its suitability for quantum information processing. However, we show that if the system consists of coupled parts with different internal energy scales then the interaction of one part with a thermal bath need not lead to loss of coherence from the other. Remarkably, we find that the protected part can remain coherent for longer when the coupling to the bath becomes stronger or the temperature is raised. Our theory will enable the design of decoherence-resistant hybrid quantum computers.

How Internally Coupled Ears Generate Temporal and Amplitude Cues for Sound Localization.

PubMed

Vedurmudi, A P; Goulet, J; Christensen-Dalsgaard, J; Young, B A; Williams, R; van Hemmen, J L

2016-01-15

In internally coupled ears, displacement of one eardrum creates pressure waves that propagate through air-filled passages in the skull and cause displacement of the opposing eardrum, and conversely. By modeling the membrane, passages, and propagating pressure waves, we show that internally coupled ears generate unique amplitude and temporal cues for sound localization. The magnitudes of both these cues are directionally dependent. The tympanic fundamental frequency segregates a low-frequency regime with constant time-difference magnification from a high-frequency domain with considerable amplitude magnification.

[IgG4-related disease].

PubMed

González-Moreno, Juan; Losada López, Inés; Ortego Centeno, Norberto

2015-12-21

IgG4-related disease is a recently described clinicopathological entity showing a wide spectrum of clinical manifestations that share a common pathology. Its most characteristic feature is the formation of inflammatory tumors in different organs, which makes differentiation mainly with neoplastic diseases fundamental. The inflammatory process is typically comprised of IgG4 lymphoplasmacytic cells. The pathophysiological role of the immunoglobulin is not clear. The treatment of choice is corticosteroids. This article aims to summarize the main features of the disease. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

The kinetic origin of delayed yielding in metallic glasses

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

Ye, Y. F.; Liu, X. D.; Wang, S.

2016-06-20

Recent experiments showed that irreversible structural change or plasticity could occur in metallic glasses (MGs) even within the apparent elastic limit after a sufficiently long waiting time. To explain this phenomenon, a stochastic shear transformation model is developed based on a unified rate theory to predict delayed yielding in MGs, which is validated afterwards through extensive atomistic simulations carried out on different MGs. On a fundamental level, an analytic framework is established in this work that links time, stress, and temperature altogether into a general yielding criterion for MGs.

Nanodiamonds: Their Structure and Optical Properties

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

Raty, J.-Y.; van Buuren, T.; Galli, G.

2002-05-14

Nanometer sized diamond is a constituent of diverse systems ranging from interstellar dusts and meteorites [1] to carbonaceous residues of detonations [2] and diamond-like films [3-5]. Many of the properties of bulk diamond have been well understood for decades, those of nanodiamond are mostly unexplored. We present a combined theoretical and experimental study showing that diamond has unique properties not only as a bulk material but also at the nanoscale, where size reduction and surface reconstruction effects are fundamentally different from those found, e.g. in Si and Ge.

A path model for Whittaker vectors

NASA Astrophysics Data System (ADS)

Di Francesco, Philippe; Kedem, Rinat; Turmunkh, Bolor

2017-06-01

In this paper we construct weighted path models to compute Whittaker vectors in the completion of Verma modules, as well as Whittaker functions of fundamental type, for all finite-dimensional simple Lie algebras, affine Lie algebras, and the quantum algebra U_q(slr+1) . This leads to series expressions for the Whittaker functions. We show how this construction leads directly to the quantum Toda equations satisfied by these functions, and to the q-difference equations in the quantum case. We investigate the critical limit of affine Whittaker functions computed in this way.

Time drawings: Spatial representation of temporal concepts.

PubMed

Leone, María Juliana; Salles, Alejo; Pulver, Alejandro; Golombek, Diego Andrés; Sigman, Mariano

2018-03-01

Time representation is a fundamental property of human cognition. Ample evidence shows that time (and numbers) are represented in space. However, how the conceptual mapping varies across individuals, scales, and temporal structures remains largely unknown. To investigate this issue, we conducted a large online study consisting in five experiments that addressed different time scales and topology: Zones of time, Seasons, Days of the week, Parts of the day and Timeline. Participants were asked to map different kinds of time events to a location in space and to determine their size and color. Results showed that time is organized in space in a hierarchical progression: some features appear to be universal (i.e. selection order), others are shaped by how time is organized in distinct cultures (i.e. location order) and, finally, some aspects vary depending on individual features such as age, gender, and chronotype (i.e. size and color). Copyright © 2018 Elsevier Inc. All rights reserved.

Acoustic analysis of speech under stress.

PubMed

Sondhi, Savita; Khan, Munna; Vijay, Ritu; Salhan, Ashok K; Chouhan, Satish

2015-01-01

When a person is emotionally charged, stress could be discerned in his voice. This paper presents a simplified and a non-invasive approach to detect psycho-physiological stress by monitoring the acoustic modifications during a stressful conversation. Voice database consists of audio clips from eight different popular FM broadcasts wherein the host of the show vexes the subjects who are otherwise unaware of the charade. The audio clips are obtained from real-life stressful conversations (no simulated emotions). Analysis is done using PRAAT software to evaluate mean fundamental frequency (F0) and formant frequencies (F1, F2, F3, F4) both in neutral and stressed state. Results suggest that F0 increases with stress; however, formant frequency decreases with stress. Comparison of Fourier and chirp spectra of short vowel segment shows that for relaxed speech, the two spectra are similar; however, for stressed speech, they differ in the high frequency range due to increased pitch modulation.

Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module

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

Silverman, T. J.; Deceglie, M. G.; Marion, B.

2013-06-01

We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitablemore » water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.« less

Seven and up: individual differences in male voice fundamental frequency emerge before puberty and remain stable throughout adulthood

NASA Astrophysics Data System (ADS)

Fouquet, Meddy; Pisanski, Katarzyna; Mathevon, Nicolas; Reby, David

2016-10-01

Voice pitch (the perceptual correlate of fundamental frequency, F0) varies considerably even among individuals of the same sex and age, communicating a host of socially and evolutionarily relevant information. However, due to the almost exclusive utilization of cross-sectional designs in previous studies, it remains unknown whether these individual differences in voice pitch emerge before, during or after sexual maturation, and whether voice pitch remains stable into adulthood. Here, we measured the F0 parameters of men who were recorded once every 7 years from age 7 to 56 as they participated in the British television documentary Up Series. Linear mixed models revealed significant effects of age on all F0 parameters, wherein F0 mean, minimum, maximum and the standard deviation of F0 showed sharp pubertal decreases between age 7 and 21, yet remained remarkably stable after age 28. Critically, men's pre-pubertal F0 at age 7 strongly predicted their F0 at every subsequent adult age, explaining up to 64% of the variance in post-pubertal F0. This finding suggests that between-individual differences in voice pitch that are known to play an important role in men's reproductive success are in fact largely determined by age 7, and may therefore be linked to prenatal and/or pre-pubertal androgen exposure.

78 FR 44619 - Aviation Rulemaking Advisory Committee (ARAC) Airman Testing Standards and Training Working Group...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... aviation accidents by incorporating task-specific risk management considerations into each Area of... the Fundamentals of Instructing (FOI) concepts listed in 14 CFR part 61. Consistent with its desire... the instrument rating ACS, its construction reflects fundamental differences between the family of...

Uncovering Racial Bias in Nursing Fundamentals Textbooks.

ERIC Educational Resources Information Center

Byrne, Michelle M.

2001-01-01

The portrayal of African Americans in nursing fundamentals textbooks was analyzed, resulting in 11 themes in the areas of history, culture, and physical assessment. Few African American leaders were included, and racial bias and stereotyping were apparent. Differences were often discussed using Eurocentric norms, and language tended to minimize…

Cosmology as Science: From Inflation to the Future

ScienceCinema

Krass, Lawrence

2018-01-11

Recent developments in cosmology bring to the forefront fundamental questions about our ability to falsify various fundamental assumptions about the universe.  I will discuss three issues that reflect different aspects of these questions:  (1) "Proving" Inflation (2) Anthropic "Explanations" (3) Cosmology of the far future.

New insights on emergence from the perspective of weak values and dynamical non-locality

NASA Astrophysics Data System (ADS)

Tollaksen, Jeff

2014-04-01

In this article, we will examine new fundamental aspects of "emergence" and "information" using novel approaches to quantum mechanics which originated from the group around Aharonov. The two-state vector formalism provides a complete description of pre- and post-selected quantum systems and has uncovered a host of new quantum phenomena which were previously hidden. The most important feature is that any weak coupling to a pre- and post-selected system is effectively a coupling to a "weak value" which is given by a simple expression depending on the two-state vector. In particular, weak values, are the outcomes of so called "weak measurements" which have recently become a very powerful tool for ultra-sensitive measurements. Using weak values, we will show how to separate a particle from its properties, not unlike the Cheshire cat story: "Well! I've often seen a cat without a grin," thought Alice; "but a grin without a cat! It's the most curious thing I ever saw in all my life!" Next, we address the question whether the physics on different scales "emerges" from quantum mechanics or whether the laws of physics at those scales are fundamental. We show that the classical limit of quantum mechanics is a far more complicated issue; it is in fact dramatically more involved and it requires a complete revision of all our intuitions. The revised intuitions can then serve as a guide to finding novel quantum effects. Next we show that novel experimental aspects of contextuality can be demonstrated with weak measurements and these suggest new restrictions on hidden variable approaches. Next we emphasize that the most important implication of the Aharonov-Bohm effect is the existence of non-local interactions which do not violate causality. Finally, we review some generalizations of quantum mechanics and their implications for "emergence" and "information." First, we review an alternative approach to quantum evolution in which each moment of time is viewed as a new "universe" and time evolution is given by correlations between different moments. Next, we present a new solution to the measurement problem involving future boundary conditions placed on the universe as a whole. Finally, we introduce another fundamental approach to quantum evolution which allows for tremendous richness in the types of allowable Hamiltonians.

3D Printed Potential and Free Energy Surfaces for Teaching Fundamental Concepts in Physical Chemistry

ERIC Educational Resources Information Center

Kaliakin, Danil S.; Zaari, Ryan R.; Varganov, Sergey A.

2015-01-01

Teaching fundamental physical chemistry concepts such as the potential energy surface, transition state, and reaction path is a challenging task. The traditionally used oversimplified 2D representation of potential and free energy surfaces makes this task even more difficult and often confuses students. We show how this 2D representation can be…

Evidence for a fundamental and pervasive shift away from nature-based recreation

PubMed Central

Pergams, Oliver R. W.; Zaradic, Patricia A.

2008-01-01

After 50 years of steady increase, per capita visits to U.S. National Parks have declined since 1987. To evaluate whether we are seeing a fundamental shift away from people's interest in nature, we tested for similar longitudinal declines in 16 time series representing four classes of nature participation variables: (i) visitation to various types of public lands in the U.S. and National Parks in Japan and Spain, (ii) number of various types of U.S. game licenses issued, (iii) indicators of time spent camping, and (iv) indicators of time spent backpacking or hiking. The four variables with the greatest per capita participation were visits to Japanese National Parks, U.S. State Parks, U.S. National Parks, and U.S. National Forests, with an average individual participating 0.74–2.75 times per year. All four time series are in downtrends, with linear regressions showing ongoing losses of −1.0% to −3.1% per year. The longest and most complete time series tested suggest that typical declines in per capita nature recreation began between 1981 and 1991, are proceeding at rates of −1.0% to −1.3% per year, and total to date −18% to −25%. Spearman correlation analyses were performed on untransformed time series and on transformed percentage year-to-year changes. Results showed very highly significant correlations between many of the highest per capita participation variables in both untransformed and in difference models, further corroborating the general downtrend in nature recreation. In conclusion, all major lines of evidence point to an ongoing and fundamental shift away from nature-based recreation. PMID:18250312

Amplitude and frequency modulation control of sound production in a mechanical model of the avian syrinx.

PubMed

Elemans, Coen P H; Muller, Mees; Larsen, Ole Naesbye; van Leeuwen, Johan L

2009-04-01

Birdsong has developed into one of the important models for motor control of learned behaviour and shows many parallels with speech acquisition in humans. However, there are several experimental limitations to studying the vocal organ - the syrinx - in vivo. The multidisciplinary approach of combining experimental data and mathematical modelling has greatly improved the understanding of neural control and peripheral motor dynamics of sound generation in birds. Here, we present a simple mechanical model of the syrinx that facilitates detailed study of vibrations and sound production. Our model resembles the 'starling resistor', a collapsible tube model, and consists of a tube with a single membrane in its casing, suspended in an external pressure chamber and driven by various pressure patterns. With this design, we can separately control 'bronchial' pressure and tension in the oscillating membrane and generate a wide variety of 'syllables' with simple sweeps of the control parameters. We show that the membrane exhibits high frequency, self-sustained oscillations in the audio range (>600 Hz fundamental frequency) using laser Doppler vibrometry, and systematically explore the conditions for sound production of the model in its control space. The fundamental frequency of the sound increases with tension in three membranes with different stiffness and mass. The lower-bound fundamental frequency increases with membrane mass. The membrane vibrations are strongly coupled to the resonance properties of the distal tube, most likely because of its reflective properties to sound waves. Our model is a gross simplification of the complex morphology found in birds, and more closely resembles mathematical models of the syrinx. Our results confirm several assumptions underlying existing mathematical models in a complex geometry.

A Multi-Stage Model for Fundamental Functional Properties in Primary Visual Cortex

PubMed Central

Hesam Shariati, Nastaran; Freeman, Alan W.

2012-01-01

Many neurons in mammalian primary visual cortex have properties such as sharp tuning for contour orientation, strong selectivity for motion direction, and insensitivity to stimulus polarity, that are not shared with their sub-cortical counterparts. Successful models have been developed for a number of these properties but in one case, direction selectivity, there is no consensus about underlying mechanisms. We here define a model that accounts for many of the empirical observations concerning direction selectivity. The model describes a single column of cat primary visual cortex and comprises a series of processing stages. Each neuron in the first cortical stage receives input from a small number of on-centre and off-centre relay cells in the lateral geniculate nucleus. Consistent with recent physiological evidence, the off-centre inputs to cortex precede the on-centre inputs by a small (∼4 ms) interval, and it is this difference that confers direction selectivity on model neurons. We show that the resulting model successfully matches the following empirical data: the proportion of cells that are direction selective; tilted spatiotemporal receptive fields; phase advance in the response to a stationary contrast-reversing grating stepped across the receptive field. The model also accounts for several other fundamental properties. Receptive fields have elongated subregions, orientation selectivity is strong, and the distribution of orientation tuning bandwidth across neurons is similar to that seen in the laboratory. Finally, neurons in the first stage have properties corresponding to simple cells, and more complex-like cells emerge in later stages. The results therefore show that a simple feed-forward model can account for a number of the fundamental properties of primary visual cortex. PMID:22496811

Similar but Different: Dynamic Social Network Analysis Highlights Fundamental Differences between the Fission-Fusion Societies of Two Equid Species, the Onager and Grevy’s Zebra

PubMed Central

Rubenstein, Daniel I.; Sundaresan, Siva R.; Fischhoff, Ilya R.; Tantipathananandh, Chayant; Berger-Wolf, Tanya Y.

2015-01-01

Understanding why animal societies take on the form that they do has benefited from insights gained by applying social network analysis to patterns of individual associations. Such analyses typically aggregate data over long time periods even though most selective forces that shape sociality have strong temporal elements. By explicitly incorporating the temporal signal in social interaction data we re-examine the network dynamics of the social systems of the evolutionarily closely-related Grevy’s zebras and wild asses that show broadly similar social organizations. By identifying dynamic communities, previously hidden differences emerge: Grevy’s zebras show more modularity than wild asses and in wild asses most communities consist of solitary individuals; and in Grevy’s zebras, lactating females show a greater propensity to switch communities than non-lactating females and males. Both patterns were missed by static network analyses and in general, adding a temporal dimension provides insights into differences associated with the size and persistence of communities as well as the frequency and synchrony of their formation. Dynamic network analysis provides insights into the functional significance of these social differences and highlights the way dynamic community analysis can be applied to other species. PMID:26488598

Full-wave generalizations of the fundamental Gaussian beam.

PubMed

Seshadri, S R

2009-12-01

The basic full wave corresponding to the fundamental Gaussian beam was discovered for the outwardly propagating wave in a half-space by the introduction of a source in the complex space. There is a class of extended full waves all of which reduce to the same fundamental Gaussian beam in the appropriate limit. For the extended full Gaussian waves that include the basic full Gaussian wave as a special case, the sources are in the complex space on different planes transverse to the propagation direction. The sources are cylindrically symmetric Gaussian distributions centered at the origin of the transverse planes, the axis of symmetry being the propagation direction. For the special case of the basic full Gaussian wave, the source is a point source. The radiation intensity of the extended full Gaussian waves is determined and their characteristics are discussed and compared with those of the fundamental Gaussian beam. The extended full Gaussian waves are also obtained for the oppositely propagating outwardly directed waves in the second half-space. The radiation intensity distributions in the two half-spaces have reflection symmetry about the midplane. The radiation intensity distributions of the various extended full Gaussian waves are not significantly different. The power carried by the extended full Gaussian waves is evaluated and compared with that of the fundamental Gaussian beam.

Investigation of the difference between spin Hall magnetoresistance rectification and spin pumping from the viewpoint of magnetization dynamics

NASA Astrophysics Data System (ADS)

Zhang, Qihan; Fan, Xiaolong; Zhou, Hengan; Kong, Wenwen; Zhou, Shiming; Gui, Y. S.; Hu, C.-M.; Xue, Desheng

2018-02-01

Spin pumping (SP) and spin rectification due to spin Hall magnetoresistance (SMR) can result in a dc resonant voltage signal, when magnetization in ferromagnetic insulator/nonmagnetic structures experiences ferromagnetic resonance. Since the two effects are often interrelated, quantitative identification of them is important for studying the dynamic nonlocal spin transport through an interface. In this letter, the key difference between SP and SMR rectification was investigated from the viewpoint of spin dynamics. The phase-dependent nature of SMR rectification, which is the fundamental characteristic distinguishing it from SP, was tested by a well-designed experiment. In this experiment, two identical yttrium iron garnet/Pt strips with a π phase difference in dynamic magnetization show the same SP signals and inverse SMR signals.

Electronegativity determination of individual surface atoms by atomic force microscopy.

PubMed

Onoda, Jo; Ondráček, Martin; Jelínek, Pavel; Sugimoto, Yoshiaki

2017-04-26

Electronegativity is a fundamental concept in chemistry. Despite its importance, the experimental determination has been limited only to ensemble-averaged techniques. Here, we report a methodology to evaluate the electronegativity of individual surface atoms by atomic force microscopy. By measuring bond energies on the surface atoms using different tips, we find characteristic linear relations between the bond energies of different chemical species. We show that the linear relation can be rationalized by Pauling's equation for polar covalent bonds. This opens the possibility to characterize the electronegativity of individual surface atoms. Moreover, we demonstrate that the method is sensitive to variation of the electronegativity of given atomic species on a surface due to different chemical environments. Our findings open up ways of analysing surface chemical reactivity at the atomic scale.

Electronegativity determination of individual surface atoms by atomic force microscopy

PubMed Central

Onoda, Jo; Ondráček, Martin; Jelínek, Pavel; Sugimoto, Yoshiaki

2017-01-01

Electronegativity is a fundamental concept in chemistry. Despite its importance, the experimental determination has been limited only to ensemble-averaged techniques. Here, we report a methodology to evaluate the electronegativity of individual surface atoms by atomic force microscopy. By measuring bond energies on the surface atoms using different tips, we find characteristic linear relations between the bond energies of different chemical species. We show that the linear relation can be rationalized by Pauling's equation for polar covalent bonds. This opens the possibility to characterize the electronegativity of individual surface atoms. Moreover, we demonstrate that the method is sensitive to variation of the electronegativity of given atomic species on a surface due to different chemical environments. Our findings open up ways of analysing surface chemical reactivity at the atomic scale. PMID:28443645

[Empathic leadership: shaping positive change].

PubMed

Wetterauer, U; Ruhl, S

2011-12-01

This paper explains the concept of empathic leadership in the setting of fundamental organisational changes. It deals with the question of how you can establish a culture of leadership, which motivates employees positively and enthuses them for the upcoming changes. It discusses the basics of empathic leadership and considers the question of how handling of emotions influences change processes and how different management styles can be used supportively during changes. With the help of a practical example the different phases of change are presented from a management point of view. Thereby the theory of different levels of employee motivation is explained inter alia. The article shows that empathic leadership also has a lasting economic effect. This can be seen particularly in the power of motivation for change, in addition to recruitment and long-term employee retention.

On creating macroscopically identical granular systems with different numbers of particles

NASA Astrophysics Data System (ADS)

van der Meer, Devaraj; Rivas, Nicolas

2015-11-01

One of the fundamental differences between granular and molecular hydrodynamics is the enormous difference in the total number of constituents. The small number of particles implies that the role of fluctuations in granular dynamics is of paramount importance. To obtain more insight in these fluctuations, we investigate to what extent it is possible to create identical granular hydrodynamic states with different number of particles. A definition is given of macroscopically equivalent systems, and the dependency of the conservation equations on the particle size is studied. We show that, in certain cases, and by appropriately scaling the microscopic variables, we are able to compare systems with significantly different number of particles that present the same macroscopic phenomenology. We apply these scalings in simulations of a vertically vibrated system, namely the density inverted granular Leidenfrost state and its transition to a buoyancy-driven convective state.

Influence of Geometries on the Assembly of Snowman-Shaped Janus Nanoparticles.

PubMed

Kang, Chengjun; Honciuc, Andrei

2018-04-24

The self-assembly of micro/nanoparticles into suprastructures is a promising way to develop reconfigurable materials and to gain insights into the fundamental question of how matter organizes itself. The geometry of particles, especially those deviating from perfectly spherical shapes, is of significant importance in colloidal assembly because it influences the particle "recognition", determines the particle packing, and ultimately dictates the formation of assembled suprastructures. In order to organize particles into desired structures, it is of vital importance to understand the relationship between the shape of the colloidal building blocks and the assembled suprastructures. This fundamental issue is an enduring topic in the assembly of molecular surfactants, but it remained elusive in colloidal assembly. To address this issue, we use snowman-shaped Janus nanoparticles (JNPs) as a model to systematically study the effect of colloidal geometries on their assembled suprastructures. Ten types of JNPs with identical chemical compositions but with different geometries were synthesized. Specifically, the synthesized JNPs differ in their lobe size ratios, phase separation degrees, and overall sizes. We show that by altering these parameters, both finite suprastructures, such as capsules with different curvatures, and nonfinite suprastructures, including free-standing single-layered or double-layered JNPs sheets, can be obtained via self-assembly. All these different types of suprastructures are constituted by highly oriented and hexagonally packed JNPs. These findings demonstrate the significance of geometries in colloidal assembly, such that slightly changing the building block geometries could result in a large variety of very different assembled structures, without altering the chemistry of the particles.

A systematic analysis of the XMM-Newton background: III. Impact of the magnetospheric environment

NASA Astrophysics Data System (ADS)

Ghizzardi, Simona; Marelli, Martino; Salvetti, David; Gastaldello, Fabio; Molendi, Silvano; De Luca, Andrea; Moretti, Alberto; Rossetti, Mariachiara; Tiengo, Andrea

2017-12-01

A detailed characterization of the particle induced background is fundamental for many of the scientific objectives of the Athena X-ray telescope, thus an adequate knowledge of the background that will be encountered by Athena is desirable. Current X-ray telescopes have shown that the intensity of the particle induced background can be highly variable. Different regions of the magnetosphere can have very different environmental conditions, which can, in principle, differently affect the particle induced background detected by the instruments. We present results concerning the influence of the magnetospheric environment on the background detected by EPIC instrument onboard XMM-Newton through the estimate of the variation of the in-Field-of-View background excess along the XMM-Newton orbit. An important contribution to the XMM background, which may affect the Athena background as well, comes from soft proton flares. Along with the flaring component a low-intensity component is also present. We find that both show modest variations in the different magnetozones and that the soft proton component shows a strong trend with the distance from Earth.

Adiabatically tapered microstructured mode converter for selective excitation of the fundamental mode in a few mode fiber.

PubMed

Taher, Aymen Belhadj; Di Bin, Philippe; Bahloul, Faouzi; Tartaret-Josnière, Etienne; Jossent, Mathieu; Février, Sébastien; Attia, Rabah

2016-01-25

We propose a new technique to selectively excite the fundamental mode in a few mode fiber (FMF). This method of excitation is made from a single mode fiber (SMF) which is inserted facing the FMF into an air-silica microstructured cane before the assembly is adiabatically tapered. We study theoretically and numerically this method by calculating the effective indices of the propagated modes, their amplitudes along the taper and the adiabaticity criteria, showing the ability to achieve an excellent selective excitation of the fundamental mode in the FMF with negligible loss. We experimentally demonstrate that the proposed solution provides a successful mode conversion and allows an almost excellent fundamental mode excitation in the FMF (representing 99.8% of the total power).

Adiabatically tapered splice for selective excitation of the fundamental mode in a multimode fiber.

PubMed

Jung, Yongmin; Jeong, Yoonchan; Brambilla, Gilberto; Richardson, David J

2009-08-01

We propose a simple and effective method to selectively excite the fundamental mode of a multimode fiber by adiabatically tapering a fusion splice to a single-mode fiber. We experimentally demonstrate the method by adiabatically tapering splice (taper waist=15 microm, uniform length=40 mm) between single-mode and multimode fiber and show that it provides a successful mode conversion/connection and allows for almost perfect fundamental mode excitation in the multimode fiber. Excellent beam quality (M(2) approximately 1.08) was achieved with low loss and high environmental stability.

Scaling relations and the fundamental line of the local group dwarf galaxies

NASA Astrophysics Data System (ADS)

Woo, Joanna; Courteau, Stéphane; Dekel, Avishai

2008-11-01

We study the scaling relations between global properties of dwarf galaxies in the local group. In addition to quantifying the correlations between pairs of variables, we explore the `shape' of the distribution of galaxies in log parameter space using standardized principal component analysis, the analysis is performed first in the 3D structural parameter space of stellar mass M*, internal velocity V and characteristic radius R* (or surface brightness μ*). It is then extended to a 4D space that includes a stellar population parameter such as metallicity Z or star formation rate . We find that the local group dwarfs basically define a one-parameter `fundamental line' (FL), primarily driven by stellar mass, M*. A more detailed inspection reveals differences between the star formation properties of dwarf irregulars (dI's) and dwarf ellipticals (dE's), beyond the tendency of the latter to be more massive. In particular, the metallicities of dI's are typically lower by a factor of 3 at a given M* and they grow faster with increasing M*, showing a tighter FL in the 4D space for the dE's. The structural scaling relations of dI's resemble those of the more massive spirals, but the dI's have lower star formation rates for a given M* which also grow faster with increasing M*. On the other hand, the FL of the dE's departs from the fundamental plane of bigger ellipticals. While the one-parameter nature of the FL and the associated slopes of the scaling relations are consistent with the general predictions of supernova feedback from Dekel & Woo, the differences between the FL's of the dE's and the dI's remain a challenge and should serve as a guide for the secondary physical processes responsible for these two types.

Characterizing resonant component in speech: A different view of tracking fundamental frequency

NASA Astrophysics Data System (ADS)

Dong, Bin

2017-05-01

Inspired by the nonlinearity and nonstationarity and the modulations in speech, Hilbert-Huang Transform and cyclostationarity analysis are employed to investigate the speech resonance in vowel in sequence. Cyclostationarity analysis is not directly manipulated on the target vowel, but on its intrinsic mode functions one by one. Thanks to the equivalence between the fundamental frequency in speech and the cyclic frequency in cyclostationarity analysis, the modulation intensity distributions of the intrinsic mode functions provide much information for the estimation of the fundamental frequency. To highlight the relationship between frequency and time, the pseudo-Hilbert spectrum is proposed to replace the Hilbert spectrum here. After contrasting the pseudo-Hilbert spectra of and the modulation intensity distributions of the intrinsic mode functions, it finds that there is usually one intrinsic mode function which works as the fundamental component of the vowel. Furthermore, the fundamental frequency of the vowel can be determined by tracing the pseudo-Hilbert spectrum of its fundamental component along the time axis. The later method is more robust to estimate the fundamental frequency, when meeting nonlinear components. Two vowels [a] and [i], picked up from a speech database FAU Aibo Emotion Corpus, are applied to validate the above findings.

FUNDAMENTAL DIFFERENCES BETWEEN NATURAL ANTIBODIES AND POLYREACTIVE IMMUNOGLOBULINS.

PubMed

Bobrovnik, S A; Demchenko, M A; Komisarenko, S V

2015-01-01

A problem of similarity and differences between so-called polyreactive immunoglobulins (PRIGs) and natural antibodies (NAbs), capable of cross-reacting with some structurally dissimilar antigens, has been considered. The analysis of mechanisms of an unspecific interaction between PRIGs or NAbs and antigens evidences for the fact that essential differences exist between these substances. These differences permit classifying the abovementioned substances as different types of immunoglobulin molecules. The major difference between PRIGs and NAbs may include both the mechanisms of the above mentioned immunoglobulin molecules binding to antigens and their interaction affinity, as well as an absolutely different influence of some low-molecular substances on the efficiency of the interaction with antigens. Relying on the obtained data it can be assumed that, since PRIGs and NAbs have fundamental differences, they may perform not only similar but also different functions of the immune system.

Fundamental Limits:. Developing New Tools for a Better Understanding of Second-Order Molecular Nonlinear Optics

NASA Astrophysics Data System (ADS)

Pérez-Moreno, Javier; Clays, Koen

The generalized Thomas-Kuhn sum rules are used to characterize the nonlinear optical response of organic chromophores in terms of fundamental parameters that can be measured experimentally. The nonlinear optical performance of organic molecules is evaluated from the combination of hyper-Rayleigh scattering measurements and the analysis in terms of the fundamental limits. Different strategies for the enhancement of nonlinear optical behavior at the molecular and supramolecular level are evaluated and new paradigms for the design of more efficient nonlinear optical molecules are proposed and investigated.

Suppressive mechanisms in visual motion processing: From perception to intelligence.

PubMed

Tadin, Duje

2015-10-01

Perception operates on an immense amount of incoming information that greatly exceeds the brain's processing capacity. Because of this fundamental limitation, the ability to suppress irrelevant information is a key determinant of perceptual efficiency. Here, I will review a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. These spatial suppression mechanisms are adaptive, operating only when sensory inputs are sufficiently robust to guarantee visibility. Converging correlational and causal evidence links these behavioral results with inhibitory center-surround mechanisms, namely those in cortical area MT. Spatial suppression is abnormally weak in several special populations, including the elderly and individuals with schizophrenia-a deficit that is evidenced by better-than-normal direction discriminations of large moving stimuli. Theoretical work shows that this abnormal weakening of spatial suppression should result in motion segregation deficits, but direct behavioral support of this hypothesis is lacking. Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, I will discuss recent research that shows individual differences in spatial suppression of motion signals strongly predict individual variations in IQ scores. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Fundamental niche prediction of the pathogenic yeasts Cryptococcus neoformans and Cryptococcus gattii in Europe.

PubMed

Cogliati, Massimo; Puccianti, Erika; Montagna, Maria T; De Donno, Antonella; Susever, Serdar; Ergin, Cagri; Velegraki, Aristea; Ellabib, Mohamed S; Nardoni, Simona; Macci, Cristina; Trovato, Laura; Dipineto, Ludovico; Rickerts, Volker; Akcaglar, Sevim; Mlinaric-Missoni, Emilija; Bertout, Sebastien; Vencà, Ana C F; Sampaio, Ana C; Criseo, Giuseppe; Ranque, Stéphane; Çerikçioğlu, Nilgün; Marchese, Anna; Vezzulli, Luigi; Ilkit, Macit; Desnos-Ollivier, Marie; Pasquale, Vincenzo; Polacheck, Itzhack; Scopa, Antonio; Meyer, Wieland; Ferreira-Paim, Kennio; Hagen, Ferry; Boekhout, Teun; Dromer, Françoise; Varma, Ashok; Kwon-Chung, Kyung J; Inácio, Joäo; Colom, Maria F

2017-10-01

Fundamental niche prediction of Cryptococcus neoformans and Cryptococcus gattii in Europe is an important tool to understand where these pathogenic yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In this study, occurrence data for C. neoformans and C. gattii were compared by MaxEnt software with several bioclimatic conditions as well as with soil characteristics and land use. The results showed that C. gattii distribution can be predicted with high probability along the Mediterranean coast. The analysis of variables showed that its distribution is limited by low temperatures during the coldest season, and by heavy precipitations in the driest season. C. neoformans var. grubii is able to colonize the same areas of C. gattii but is more tolerant to cold winter temperatures and summer precipitations. In contrast, the C. neoformans var. neoformans map was completely different. The best conditions for its survival were displayed in sub-continental areas and not along the Mediterranean coasts. In conclusion, we produced for the first time detailed prediction maps of the species and varieties of the C. neoformans and C. gattii species complex in Europe and Mediterranean area. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Generation and evolution of mode-locked noise-like square-wave pulses in a large-anomalous-dispersion Er-doped ring fiber laser.

PubMed

Liu, Jun; Chen, Yu; Tang, Pinghua; Xu, Changwen; Zhao, Chujun; Zhang, Han; Wen, Shuangchun

2015-03-09

In a passively mode-locked Erbium-doped fiber laser with large anomalous-dispersion, we experimentally demonstrate the formation of noise-like square-wave pulse, which shows quite different features from conventional dissipative soliton resonance (DSR). The corresponding temporal and spectral characteristics of a variety of operation states, including Q-switched mode-locking, continuous-wave mode-locking and Raman-induced noise-like pulse near the lasing threshold, are also investigated. Stable noise-like square-wave mode-locked pulses can be obtained at a fundamental repetition frequency of 195 kHz, with pulse packet duration tunable from 15 ns to 306 ns and per-pulse energy up to 200 nJ. By reducing the linear cavity loss, stable higher-order harmonic mode-locking had also been observed, with pulse duration ranging from 37 ns at the 21st order harmonic wave to 320 ns at the fundamental order. After propagating along a piece of long telecom fiber, the generated square-wave pulses do not show any obvious change, indicating that the generated noise-like square-wave pulse can be considered as high-energy pulse packet for some promising applications. These experimental results should shed some light on the further understanding of the mechanism and characteristics of noise-like square-wave pulses.

Fundamental frequency discrimination and speech perception in noise in cochlear implant simulationsa)

PubMed Central

Carroll, Jeff; Zeng, Fan-Gang

2007-01-01

Increasing the number of channels at low frequencies improves discrimination of fundamental frequency (F0) in cochlear implants [Geurts and Wouters 2004]. We conducted three experiments to test whether improved F0 discrimination can be translated into increased speech intelligibility in noise in a cochlear implant simulation. The first experiment measured F0 discrimination and speech intelligibility in quiet as a function of channel density over different frequency regions. The results from this experiment showed a tradeoff in performance between F0 discrimination and speech intelligibility with a limited number of channels. The second experiment tested whether improved F0 discrimination and optimizing this tradeoff could improve speech performance with a competing talker. However, improved F0 discrimination did not improve speech intelligibility in noise. The third experiment identified the critical number of channels needed at low frequencies to improve speech intelligibility in noise. The result showed that, while 16 channels below 500 Hz were needed to observe any improvement in speech intelligibility in noise, even 32 channels did not achieve normal performance. Theoretically, these results suggest that without accurate spectral coding, F0 discrimination and speech perception in noise are two independent processes. Practically, the present results illustrate the need to increase the number of independent channels in cochlear implants. PMID:17604581

Contribution of the Multi Attribute Value Theory to conflict resolution in groundwater management. Application to the Mancha Oriental groundwater system, Spain

NASA Astrophysics Data System (ADS)

Apperl, B.; Andreu, J.; Karjalainen, T. P.; Pulido-Velazquez, M.

2014-09-01

The implementation of the EU Water Framework Directive demands participatory water resource management approaches. Decision making in groundwater quantity and quality management is complex because of the existence of many independent actors, heterogeneous stakeholder interests, multiple objectives, different potential policies, and uncertain outcomes. Conflicting stakeholder interests have been often identified as an impediment to the realization and success of water regulations and policies. The management of complex groundwater systems requires clarifying stakeholders' positions (identifying stakeholders preferences and values), improving transparency with respect to outcomes of alternatives, and moving the discussion from the selection of alternatives towards definition of fundamental objectives (value-thinking approach), what facilitates negotiation. The aims of the study are to analyse the potential of the multi attribute value theory for conflict resolution in groundwater management and to evaluate the benefit of stakeholder incorporation in the different stages of the planning process to find an overall satisfying solution for groundwater management. The research was conducted in the Mancha Oriental groundwater system (Spain), subject to an intensive use of groundwater for irrigation. A complex set of objectives and attributes were defined, and the management alternatives were created by a combination of different fundamental actions, considering different implementation stages and future changes in water resources availability. Interviews were conducted with representative stakeholder groups using an interactive platform, showing simultaneously the consequences of changes of preferences to the alternative ranking. Results show that the acceptation of alternatives depends strongly on the combination of measures and the implementation stages. Uncertainties of the results were notable but did not influence heavily on the alternative ranking. The expected reduction of future groundwater resources by climate change increases the conflict potential. The implementation of the method to a very complex case study, with many conflicting objectives and alternatives and uncertain outcomes, including future scenarios under water limiting conditions, illustrate the potential of the method for supporting management decisions.

Contribution of the multi-attribute value theory to conflict resolution in groundwater management - application to the Mancha Oriental groundwater system, Spain

NASA Astrophysics Data System (ADS)

Apperl, B.; Pulido-Velazquez, M.; Andreu, J.; Karjalainen, T. P.

2015-03-01

The implementation of the EU Water Framework Directive demands participatory water resource management approaches. Decision making in groundwater quantity and quality management is complex because of the existence of many independent actors, heterogeneous stakeholder interests, multiple objectives, different potential policies, and uncertain outcomes. Conflicting stakeholder interests have often been identified as an impediment to the realisation and success of water regulations and policies. The management of complex groundwater systems requires the clarification of stakeholders' positions (identifying stakeholder preferences and values), improving transparency with respect to outcomes of alternatives, and moving the discussion from the selection of alternatives towards the definition of fundamental objectives (value-thinking approach), which facilitates negotiation. The aims of the study are to analyse the potential of the multi-attribute value theory for conflict resolution in groundwater management and to evaluate the benefit of stakeholder incorporation into the different stages of the planning process, to find an overall satisfying solution for groundwater management. The research was conducted in the Mancha Oriental groundwater system (Spain), subject to intensive use of groundwater for irrigation. A complex set of objectives and attributes was defined, and the management alternatives were created by a combination of different fundamental actions, considering different implementation stages and future changes in water resource availability. Interviews were conducted with representative stakeholder groups using an interactive platform, showing simultaneously the consequences of changes in preferences to the alternative ranking. Results show that the approval of alternatives depends strongly on the combination of measures and the implementation stages. Uncertainties in the results were notable, but did not influence the alternative ranking heavily. The expected reduction in future groundwater resources by climate change increases the conflict potential. The implementation of the method in a very complex case study, with many conflicting objectives and alternatives and uncertain outcomes, including future scenarios under water limiting conditions, illustrates the potential of the method for supporting management decisions.

Fundamentals of Orthodox Culture (FOC): A New Subject in Russia's Schools

ERIC Educational Resources Information Center

Willems, Joachim

2007-01-01

The question of religious education is one of the most controversial questions in the current discussions on religion and politics in Russia. Most notably a new subject, Fundamentals of Orthodox Culture (FOC), is of interest because it differs markedly from Western European approaches to religious education. Referring to "Culturology"…

On-Line Syntax: Thoughts on the Temporality of Spoken Language

ERIC Educational Resources Information Center

Auer, Peter

2009-01-01

One fundamental difference between spoken and written language has to do with the "linearity" of speaking in time, in that the temporal structure of speaking is inherently the outcome of an interactive process between speaker and listener. But despite the status of "linearity" as one of Saussure's fundamental principles, in practice little more…

Unveiling MERCURY's Mysteries with Bepicolombo

NASA Astrophysics Data System (ADS)

Benkhoff, J.; Fujimoto, M.; Murakami, G.; Zender, J.

2017-09-01

NASA's MESSENGER mission has fundamentally changed our view of the innermost planet. Mercury is in many ways a very different planet from what we were expecting. Now BepiColombo has to follow up on answering the fundamental questions that MESSENGER raised and go beyond. The authors are the JAXA and ESA Project Scientists of this wonderful mission.

How fundamental are fundamental constants?

NASA Astrophysics Data System (ADS)

Duff, M. J.

2015-01-01

I argue that the laws of physics should be independent of one's choice of units or measuring apparatus. This is the case if they are framed in terms of dimensionless numbers such as the fine structure constant, ?. For example, the standard model of particle physics has 19 such dimensionless parameters whose values all observers can agree on, irrespective of what clock, rulers or scales? they use to measure them. Dimensional constants, on the other hand, such as ?, c, G, e and k ?, are merely human constructs whose number and values differ from one choice of units to the next. In this sense, only dimensionless constants are 'fundamental'. Similarly, the possible time variation of dimensionless fundamental 'constants' of nature is operationally well defined and a legitimate subject of physical enquiry. By contrast, the time variation of dimensional constants such as ? or ? on which a good many (in my opinion, confusing) papers have been written, is a unit-dependent phenomenon on which different observers might disagree depending on their apparatus. All these confusions disappear if one asks only unit-independent questions. We provide a selection of opposing opinions in the literature and respond accordingly.

Higher-order harmonics of limited diffraction Bessel beams

PubMed

Ding; Lu

2000-03-01

We investigate theoretically the nonlinear propagation of the limited diffraction Bessel beam in nonlinear media, under the successive approximation of the KZK equation. The result shows that the nth-order harmonic of the Bessel beam, like its fundamental component, is radially limited diffracting, and that the main beamwidth of the nth-order harmonic is exactly 1/n times that of the fundamental.

Optimized two- and three-colour laser pulses for the intense terahertz wave generation

NASA Astrophysics Data System (ADS)

Zhang, Lei; Wang, Guo-Li; Zhou, Xiao-Xin

2016-11-01

Based on the photocurrent model, we perform a theoretical study on the optimization of terahertz (THz) wave emission from argon gas irradiated by the two- and three-colour laser fields. To obtain stronger THz radiation for the given conditions, a genetic algorithm method is applied to search for the optimum laser parameters. For the two-colour field, our optimizations reveal two types of optimal scheme, and each one dominates the THz generation in different regions of intensity ratio for a given total laser intensity. One scheme is the combination of a fundamental laser pulse and its second harmonic, while the other is the fundamental pulse with its fourth harmonic. For each scheme, the optimal intensity ratio and phase delay are obtained. For the three-colour case, our optimization shows that the excellent waveform for the strongest THz radiation is composed of a fundamental laser pulse, and its second, third harmonics, with appropriate intensity ratio and carrier-envelope phase. Such a 3-colour field can generate strong THz radiation comparable with a 10-colour sawtooth wave [Martínez et al., Phys. Rev. Lett. 114, 183901 (2015)]. The physical mechanisms for the enhancement of THz wave emission in gases are also discussed in detail. Our results give helpful guidance for intense THz generation with tabletop femtosecond laser device in experiment.

CrossFit athletes exhibit high symmetry of fundamental movement patterns. A cross-sectional study

PubMed Central

Tafuri, Silvio; Notarnicola, Angela; Monno, Antonello; Ferretti, Francesco; Moretti, Biagio

2016-01-01

Summary Background even if CrossFit training programs accounted actually more than 7500 gyms affiliated in the USA and more than 2000 in Europe and involved today more than 1 million of people, actually there were not several studies about the effect of the CrossFit on the health and sport performance. The aim of these research was to evaluate the performance in 7 fundamental movement patterns using a standardized methods, the Functional Movement Screen (FMS). Methods we enrolled three groups of athletes (age 17–40 years; >6 months of training programs): CrossFitters, body builders and professional weightlifters. FMS test was performed to all people enrolled. Scores of FMS test was examined comparing three groups. Results no differences in the three groups were showed in the mean score values of each test and in total score, except for shoulder mobility test (higher among CrossFitters) and trunk stability push-up test (higher among weightlifter). Agreement between the test performed on the two sides was higher in CrossFit groups for hurdle step (93.2%), in line lung (86%), rotary stability test (95.3%) and shoulder mobility (90.7%; p<0.001). Conclusions CrossFitters seem to have a high level of concordance in the scores achieved in bilateral test. CrossFit seems to produce marked symmetry in some fundamental movements compared to weightlifting and bodybuilding. PMID:27331045

CrossFit athletes exhibit high symmetry of fundamental movement patterns. A cross-sectional study.

PubMed

Tafuri, Silvio; Notarnicola, Angela; Monno, Antonello; Ferretti, Francesco; Moretti, Biagio

2016-01-01

even if CrossFit training programs accounted actually more than 7500 gyms affiliated in the USA and more than 2000 in Europe and involved today more than 1 million of people, actually there were not several studies about the effect of the CrossFit on the health and sport performance. The aim of these research was to evaluate the performance in 7 fundamental movement patterns using a standardized methods, the Functional Movement Screen (FMS). we enrolled three groups of athletes (age 17-40 years; >6 months of training programs): CrossFitters, body builders and professional weightlifters. FMS test was performed to all people enrolled. Scores of FMS test was examined comparing three groups. no differences in the three groups were showed in the mean score values of each test and in total score, except for shoulder mobility test (higher among CrossFitters) and trunk stability push-up test (higher among weightlifter). Agreement between the test performed on the two sides was higher in CrossFit groups for hurdle step (93.2%), in line lung (86%), rotary stability test (95.3%) and shoulder mobility (90.7%; p<0.001). CrossFitters seem to have a high level of concordance in the scores achieved in bilateral test. CrossFit seems to produce marked symmetry in some fundamental movements compared to weightlifting and bodybuilding.

Long-term field study of sea kraits in New Caledonia: fundamental issues and conservation.

PubMed

Bonnet, Xavier

2012-08-01

This short review focuses on the findings associated with a long-term field study on two species of sea kraits in New Caledonia. Since 2002, more than 30 sites in the lagoon have been sampled, and in most places mark-recapture was implemented. We collected detailed data on more than 14,000 marked individuals (>6000 recaptures) and used different techniques (stable isotopes, bio-logging, analyses of diet). The objective was fundamental: to examine how amphibious snakes cope with both terrestrial and aquatic environments. As access to abundant food is likely the main evolutionary driver for the return transition toward the sea in marine tetrapods, foraging ecology was an important part of the research and novel information was obtained on this subject. Rapidly however, field observations revealed the potential interest of sea kraits for conservation issues. Our results show that these snakes are useful bio-indicators of marine biodiversity; they also provide a useful signal to monitor levels of contamination by heavy metals in the lagoon, and more generally as a means of studying the functioning of reef ecosystems. Importantly, anecdotal observations (e.g., a krait drinking during rain) provided unsuspected physiological insights of general importance to fundamental problems and conservation. One of the lessons of this long-term study is that key results emerged in an unexpected way, but all were dependent on intensive field work.

Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico.

PubMed

Lowe, Michael R; Wu, Wei; Peterson, Mark S; Brown-Peterson, Nancy J; Slack, William T; Schofield, Pamela J

2012-01-01

Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0-60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2-368%) and decreased during extremely dry years (86-92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

The emergence of time's arrows and special science laws from physics

PubMed Central

Loewer, Barry

2012-01-01

In this paper, I will argue that there is an important connection between two questions concerning how certain features of the macro world emerge from the laws and processes of fundamental microphysics and suggest an approach to answering these questions. The approach involves a kind of emergence but quite different from ‘top-down’ emergence discussed at the conference, for which an earlier version of this paper was written. The two questions are (i) How do ‘the arrows of time’ emerge from microphysics? (ii) How do macroscopic special science laws and causation emerge from microphysics? Answering these questions is especially urgent for those, who like myself, think that a certain version of physicalism, which I call ‘micro-physical completeness’ (MC), is true. According to MC, there are fundamental dynamical laws that completely govern (deterministically or probabilistically), the evolution of all micro-physical events and there are no additional ontologically independent dynamical or causal special science laws. In other words, there is no ontologically independent ‘top-down’ causation. Of course, MC does not imply that physicists now or ever will know or propose the complete laws of physics. Or even if the complete laws were known we would know how special science properties and laws reduce to laws and properties of fundamental physics. Rather, MC is a contingent metaphysical claim about the laws of our world. After a discussion of the two questions, I will argue the key to showing how it is possible for the arrows of time and the special science laws to emerge from microphysics and a certain account of how thermodynamics is related to fundamental dynamical laws. PMID:23386956

The emergence of time's arrows and special science laws from physics.

PubMed

Loewer, Barry

2012-02-06

In this paper, I will argue that there is an important connection between two questions concerning how certain features of the macro world emerge from the laws and processes of fundamental microphysics and suggest an approach to answering these questions. The approach involves a kind of emergence but quite different from 'top-down' emergence discussed at the conference, for which an earlier version of this paper was written. The two questions are (i) How do 'the arrows of time' emerge from microphysics? (ii) How do macroscopic special science laws and causation emerge from microphysics? Answering these questions is especially urgent for those, who like myself, think that a certain version of physicalism, which I call 'micro-physical completeness' (MC), is true. According to MC, there are fundamental dynamical laws that completely govern (deterministically or probabilistically), the evolution of all micro-physical events and there are no additional ontologically independent dynamical or causal special science laws. In other words, there is no ontologically independent 'top-down' causation. Of course, MC does not imply that physicists now or ever will know or propose the complete laws of physics. Or even if the complete laws were known we would know how special science properties and laws reduce to laws and properties of fundamental physics. Rather, MC is a contingent metaphysical claim about the laws of our world. After a discussion of the two questions, I will argue the key to showing how it is possible for the arrows of time and the special science laws to emerge from microphysics and a certain account of how thermodynamics is related to fundamental dynamical laws.

Survival, Growth and Reproduction of Non-Native Nile Tilapia II: Fundamental Niche Projections and Invasion Potential in the Northern Gulf of Mexico

PubMed Central

Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

2012-01-01

Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi. PMID:22848533

Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico

USGS Publications Warehouse

Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

2012-01-01

Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60 MHz phantom and ex vivo results

PubMed Central

Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K. Kirk

2013-01-01

The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than –60 dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 μm finer and –3 dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200 μm in diameter with 6 dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. PMID:22871273

Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.

PubMed

Monahan, William B; Tingley, Morgan W

2012-01-01

The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus). Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004) further shows that: (i) existing fundamental and occupied niche centroids did not undergo directional change, (ii) interannual changes in the two niche centroids were correlated, (iii) temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv) most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced changes to the realized environmental space. Such insights may be used to conceptualize mechanistic climatic niche models in birds and other taxa.

The Delta Connectome: A network-based framework for studying connectivity in river deltas

NASA Astrophysics Data System (ADS)

Passalacqua, Paola

2017-01-01

Many deltas, including the Mississippi River Delta, have been losing land at fast rates compromising the safety and sustainability of their ecosystems. Knowledge of delta vulnerability has raised global concern and stimulated active interdisciplinary research as deltas are densely populated landscapes, rich in agriculture, fisheries, oil and gas, and important means for navigation. There are many ways of looking at this problem which all contribute to a deeper understanding of the functioning of coastal systems. One aspect that has been overlooked thus far, yet fundamental for advancing delta science is connectivity, both physical (how different portions of the system interact with each other) as well as conceptual (pathways of process coupling). In this paper, I propose a framework called Delta Connectome for studying connectivity in river deltas based on different representations of a delta as a network. After analyzing the classic network representation as a set of nodes (e.g., bifurcations and junctions or regions with distinct physical or statistical behavior) and links (e.g., channels), I show that from connectivity considerations the delta emerges as a leaky network that continuously exchanges fluxes of matter, energy, and information with its surroundings and evolves over time. I explore each network representation and show through several examples how quantifying connectivity can bring to light aspects of deltaic systems so far unexplored and yet fundamental to understanding system functioning and informing coastal management and restoration. This paper serves both as an introduction to the Delta Connectome framework as well as a review of recent applications of the concepts of network and connectivity to deltaic systems within the Connectome framework.

Glottal flow through a two-mass model: comparison of Navier-Stokes solutions with simplified models.

PubMed

de Vries, M P; Schutte, H K; Veldman, A E P; Verkerke, G J

2002-04-01

A new numerical model of the vocal folds is presented based on the well-known two-mass models of the vocal folds. The two-mass model is coupled to a model of glottal airflow based on the incompressible Navier-Stokes equations. Glottal waves are produced using different initial glottal gaps and different subglottal pressures. Fundamental frequency, glottal peak flow, and closed phase of the glottal waves have been compared with values known from the literature. The phonation threshold pressure was determined for different initial glottal gaps. The phonation threshold pressure obtained using the flow model with Navier-Stokes equations corresponds better to values determined in normal phonation than the phonation threshold pressure obtained using the flow model based on the Bernoulli equation. Using the Navier-Stokes equations, an increase of the subglottal pressure causes the fundamental frequency and the glottal peak flow to increase, whereas the fundamental frequency in the Bernoulli-based model does not change with increasing pressure.

Influence of vibration on structure rheological properties of a highly concentrated suspension

NASA Astrophysics Data System (ADS)

Ouriev Uriev, Boris N.; Uriev, Naum B.

2005-08-01

The influence of mechanical vibration on the flow properties of a highly concentrated multiphase food system is explored in this work. An experimental set-up was designed and adapted to a conventional rotational rheometer with precise rheological characterization capability. A number of calibration tests were performed prior to fundamental experiments with a highly concentrated chocolate suspension. Also, the prediction of wall slippage in shear flow under vibration was evaluated. Analysis of the boundary conditions shows that no side effects such as wall slippage or the Taylor effect were present during the shear experiment under vibration. It was found that superposition of mechanical vibration and shear flow radically decreases the shear viscosity. Comparison between reference shear viscosities at specified shear rates and those measured under vibration shows considerable differences in flow properties. Conversion of the behaviour of the concentrated suspension from strongly shear-thinning to Newtonian flow is reported. Also, the appearance of vibration-induced dilatancy as a new phenomenon is described. It is suggested to relate such phenomena to the non-equilibrium between structure formation and disintegration under vibration and hydrodynamic forces of shear flow. The influence of vibration on structure formation can be well observed during measurement of the yield value of the chocolate suspension under vibration. Comparison with reference data shows how sensitive the structure of the concentrated suspension is to vibration in general. The effects and observations revealed provide a solid basis for further fundamental investigations of structure formation regularities in the flow of any highly concentrated system. The results also show the technological potential for non-conventional treatment of concentrated, multiphase systems.

A photometric analysis of Abell 1689: two-dimensional multistructure decomposition, morphological classification and the Fundamental Plane

NASA Astrophysics Data System (ADS)

Dalla Bontà, E.; Davies, R. L.; Houghton, R. C. W.; D'Eugenio, F.; Méndez-Abreu, J.

2018-02-01

We present a photometric analysis of 65 galaxies in the rich cluster Abell 1689 at z = 0.183, using the Hubble Space Telescope Advanced Camera for Surveys archive images in the rest-frame V band. We perform two-dimensional multicomponent photometric decomposition of each galaxy adopting different models of the surface-brightness distribution. We present an accurate morphological classification for each of the sample galaxies. For 50 early-type galaxies, we fit both a de Vaucouleurs law and a Sérsic law; S0s are modelled by also including a disc component described by an exponential law. Bars of SB0s are described by the profile of a Ferrers ellipsoid. For the 15 spirals, we model a Sérsic bulge, exponential disc and, when required, a Ferrers bar component. We derive the Fundamental Plane (FP) by fitting 40 early-type galaxies in the sample, using different surface-brightness distributions. We find that the tightest plane is that derived by Sérsic bulges. We find that bulges of spirals lie on the same relation. The FP is better defined by the bulges alone rather than the entire galaxies. Comparison with local samples shows both an offset and rotation in the FP of Abell 1689.

The role of fundamental frequency and formants in the perception of speaker sex

NASA Astrophysics Data System (ADS)

Hillenbrand, James M.

2005-09-01

The purpose of this study was to determine the relative contributions of fundamental frequency (F0) and formants in controlling the speaker-sex percept. A source-filter synthesizer was used to create four versions of 25 sentences spoken by men: (1) unmodified synthesis; (2) F0 only shifted up toward values typical of women; (3) formants only shifted up toward values typical of women; and (4) both F0 and formants shifted up. Identical methods were used to generate four comparable versions of 25 sentences spoken by women (e.g., unmodified synthesis, F0 only shifted down toward values typical of men, etc.). Listening tests showed: (1) perceived talker sex for the unmodified synthesis conditions was nearly always correct; (2) shifting both F0 and formants was usually effective (~82%) in changing the perceived sex of the utterance; (3) shifting either F0 or formants alone was usually ineffective in changing the perceived sex of the utterance. Both F0 and formants are apparently needed to specify speaker sex, though even together these cues are not entirely effective. Results also suggested that F0 is just slightly more important than formants, despite the fact that the male-female difference in F0 is proportionally much larger than the difference in formants. [Work supported by NIH.

Phenomenological modeling of nonlinear holograms based on metallic geometric metasurfaces.

PubMed

Ye, Weimin; Li, Xin; Liu, Juan; Zhang, Shuang

2016-10-31

Benefiting from efficient local phase and amplitude control at the subwavelength scale, metasurfaces offer a new platform for computer generated holography with high spatial resolution. Three-dimensional and high efficient holograms have been realized by metasurfaces constituted by subwavelength meta-atoms with spatially varying geometries or orientations. Metasurfaces have been recently extended to the nonlinear optical regime to generate holographic images in harmonic generation waves. Thus far, there has been no vector field simulation of nonlinear metasurface holograms because of the tremendous computational challenge in numerically calculating the collective nonlinear responses of the large number of different subwavelength meta-atoms in a hologram. Here, we propose a general phenomenological method to model nonlinear metasurface holograms based on the assumption that every meta-atom could be described by a localized nonlinear polarizability tensor. Applied to geometric nonlinear metasurfaces, we numerically model the holographic images formed by the second-harmonic waves of different spins. We show that, in contrast to the metasurface holograms operating in the linear optical regime, the wavelength of incident fundamental light should be slightly detuned from the fundamental resonant wavelength to optimize the efficiency and quality of nonlinear holographic images. The proposed modeling provides a general method to simulate nonlinear optical devices based on metallic metasurfaces.

Medial septal GABAergic projection neurons promote object exploration behavior and type 2 theta rhythm

PubMed Central

Gangadharan, Gireesh; Shin, Jonghan; Kim, Seong-Wook; Kim, Angela; Paydar, Afshin; Kim, Duk-Soo; Miyazaki, Taisuke; Watanabe, Masahiko; Yanagawa, Yuchio; Kim, Jinhyun; Kim, Yeon-Soo; Kim, Daesoo; Shin, Hee-Sup

2016-01-01

Exploratory drive is one of the most fundamental emotions, of all organisms, that are evoked by novelty stimulation. Exploratory behavior plays a fundamental role in motivation, learning, and well-being of organisms. Diverse exploratory behaviors have been described, although their heterogeneity is not certain because of the lack of solid experimental evidence for their distinction. Here we present results demonstrating that different neural mechanisms underlie different exploratory behaviors. Localized Cav3.1 knockdown in the medial septum (MS) selectively enhanced object exploration, whereas the null mutant (KO) mice showed enhanced-object exploration as well as open-field exploration. In MS knockdown mice, only type 2 hippocampal theta rhythm was enhanced, whereas both type 1 and type 2 theta rhythm were enhanced in KO mice. This selective effect was accompanied by markedly increased excitability of septo-hippocampal GABAergic projection neurons in the MS lacking T-type Ca2+ channels. Furthermore, optogenetic activation of the septo-hippocampal GABAergic pathway in WT mice also selectively enhanced object exploration behavior and type 2 theta rhythm, whereas inhibition of the same pathway decreased the behavior and the rhythm. These findings define object exploration distinguished from open-field exploration and reveal a critical role of T-type Ca2+ channels in the medial septal GABAergic projection neurons in this behavior. PMID:27208094

A comparison of spectral magnitude and phase-locking value analyses of the frequency-following response to complex tones

PubMed Central

Zhu, Li; Bharadwaj, Hari; Xia, Jing; Shinn-Cunningham, Barbara

2013-01-01

Two experiments, both presenting diotic, harmonic tone complexes (100 Hz fundamental), were conducted to explore the envelope-related component of the frequency-following response (FFRENV), a measure of synchronous, subcortical neural activity evoked by a periodic acoustic input. Experiment 1 directly compared two common analysis methods, computing the magnitude spectrum and the phase-locking value (PLV). Bootstrapping identified which FFRENV frequency components were statistically above the noise floor for each metric and quantified the statistical power of the approaches. Across listeners and conditions, the two methods produced highly correlated results. However, PLV analysis required fewer processing stages to produce readily interpretable results. Moreover, at the fundamental frequency of the input, PLVs were farther above the metric's noise floor than spectral magnitudes. Having established the advantages of PLV analysis, the efficacy of the approach was further demonstrated by investigating how different acoustic frequencies contribute to FFRENV, analyzing responses to complex tones composed of different acoustic harmonics of 100 Hz (Experiment 2). Results show that the FFRENV response is dominated by peripheral auditory channels responding to unresolved harmonics, although low-frequency channels driven by resolved harmonics also contribute. These results demonstrate the utility of the PLV for quantifying the strength of FFRENV across conditions. PMID:23862815

Electronic structure and metallization of cubic GdH{sub 3} under pressure: Ab initio many-body GW calculations

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

Kong, Bo, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn; Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018; Zhang, Yachao, E-mail: kong79@yeah.net, E-mail: yachao.zhang@pku.edu.cn

The electronic structures of the cubic GdH{sub 3} are extensively investigated using the ab initio many-body GW calculations treating the Gd 4f electrons either in the core (4f-core) or in the valence states (4f-val). Different degrees of quasiparticle (QP) self-consistent calculations with the different starting points are used to correct the failures of the GGA/GGA + U/HSE03 calculations. In the 4f-core case, GGA + G{sub 0}W{sub 0} calculations give a fundamental band gap of 1.72 eV, while GGA+ GW{sub 0} or GGA + GW calculations present a larger band gap. In the 4f-val case, the nonlocal exchange-correlation (xc) functional HSE03 can account much better for the strong localizationmore » of the 4f states than the semilocal or Hubbard U corrected xc functional in the Kohn–Sham equation. We show that the fundamental gap of the antiferromagnetic (AFM) or ferromagnetic (FM) GdH{sub 3} can be opened up by solving the QP equation with improved starting point of eigenvalues and wave functions given by HSE03. The HSE03 + G{sub 0}W{sub 0} calculations present a fundamental band gap of 2.73 eV in the AFM configuration, and the results of the corresponding GW{sub 0} and GW calculations are 2.89 and 3.03 eV, respectively. In general, for the cubic structure, the fundamental gap from G{sub 0}W{sub 0} calculations in the 4f-core case is the closest to the real result. By G{sub 0}W{sub 0} calculations in the 4f-core case, we find that H or Gd defects can strongly affect the band structure, especially the H defects. We explain the mechanism in terms of the possible electron correlation on the hydrogen site. Under compression, the insulator-to-metal transition in the cubic GdH{sub 3} occurs around 40 GPa, which might be a satisfied prediction.« less

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

Mohapi, N.; Hees, A.; Larena, J., E-mail: n.mohapi@gmail.com, E-mail: a.hees@ru.ac.za, E-mail: j.larena@ru.ac.za

The Einstein Equivalence Principle is a fundamental principle of the theory of General Relativity. While this principle has been thoroughly tested with standard matter, the question of its validity in the Dark sector remains open. In this paper, we consider a general tensor-scalar theory that allows to test the equivalence principle in the Dark sector by introducing two different conformal couplings to standard matter and to Dark matter. We constrain these couplings by considering galactic observations of strong lensing and of velocity dispersion. Our analysis shows that, in the case of a violation of the Einstein Equivalence Principle, data favourmore » violations through coupling strengths that are of opposite signs for ordinary and Dark matter. At the same time, our analysis does not show any significant deviations from General Relativity.« less

Stress Energy Tensor in LCFT and LOGARITHMIC Sugawara Construction

NASA Astrophysics Data System (ADS)

Kogan, Ian I.; Nichols, Alexander

We discuss the partners of the stress energy tensor and their structure in Logarithmic conformal field theories. In particular we draw attention to the fundamental differences between theories with zero and non-zero central charge. However they are both characterised by at least two independent parameters. We show how, by using a generalised Sugawara construction, one can calculate the logarithmic partner of T. We show that such a construction works in the c=-2 theory using the conformal dimension one primary currents which generate a logarithmic extension of the Kac-Moody algebra. This is an expanded version of a talk presented by A. Nichols at the conference on Logarithmic Conformal Field Theory and its Applications in Tehran Iran, 2001.

The relationship between social status and the components of agency.

PubMed

Louvet, Eva; Cambon, Laurent; Milhabet, Isabelle; Rohmer, Odile

2018-02-20

Building on the two fundamental dimensions of social judgment distinguishing communion from agency, the purpose of the present work was to show that the strength of the relationship between social status and agency depends on specific components at issue: assertiveness, competence, and effort. Four experimental studies were conducted using two complementary paradigms. In Studies 1 and 2, we manipulated social status, and participants had to rate the target on competence, assertiveness, and effort. In Studies 3 and 4, we reversed the design. Results consistently showed that social status was primarily related to assertiveness, somewhat related to competence, and only slightly related to effort. The present research provides a better understanding of how the dimensions of social judgment are used to explain differences in social status.

[The speaking fundamental frequency and the singing voice type].

PubMed

Chernobel'skiĭ, S I

2010-01-01

The objective of this study was to determine the speaking fundamental frequency (SFO) in professional opera singers and its dependence on their voice type, if any. A total of 75 persons were available for observation using a special computer clinical program. Male voices were categorized into three groups (viz, tenor, baritone, and bass), female ones into 2 groups (soprano and mezzo-soprano). It was shown that borderlines between SFO types varied within a wide range in all study groups. Significant differences in SFO were documented between tenors, baritones, and basses and between sopranos and mezzo-sopranos; the differences were insignificant between baritones and basses. It is concluded that the speaking fundamental frequency depends on the type of the singing voice; however this characteristic may serve only as an auxiliary tool but can not be used for the classification of singing voices.

Racial residential segregation: a fundamental cause of racial disparities in health.

PubMed

Williams, D R; Collins, C

2001-01-01

Racial residential segregation is a fundamental cause of racial disparities in health. The physical separation of the races by enforced residence in certain areas is an institutional mechanism of racism that was designed to protect whites from social interaction with blacks. Despite the absence of supportive legal statutes, the degree of residential segregation remains extremely high for most African Americans in the United States. The authors review evidence that suggests that segregation is a primary cause of racial differences in socioeconomic status (SES) by determining access to education and employment opportunities. SES in turn remains a fundamental cause of racial differences in health. Segregation also creates conditions inimical to health in the social and physical environment. The authors conclude that effective efforts to eliminate racial disparities in health must seriously confront segregation and its pervasive consequences.

Fundamental motor skills, nutritional status, perceived competence, and school performance of Brazilian children in social vulnerability: Gender comparison.

PubMed

Nobre, Glauber Carvalho; Valentini, Nadia Cristina; Nobre, Francisco Salviano Sales

2018-06-01

Being at risk or in social vulnerability situations can affect important aspects of child development. The aim of this study was to investigate fundamental motor skills (locomotor and object control) and school (writing, arithmetic, reading) performances, the perceived competence and the nutritional status of girls and boys living in social vulnerability in the poorest regions of Brazil. Two hundred eleven (211) children (87 girls, 41%), 7-10-year-old (M = 8.3, SD = 0.9), from public schools in Ceará (Brazil), living in social vulnerability, participated in the study. Children were assessed using the Test of Gross Motor Development - 2, the Body Mass Index (BMI), the Self-Perception Profile for Children, and the School Performance Test. Multivariate analysis of covariance (MANCOVA), adjusted for age, did not show any significant effect for locomotion. There was an effect of gender on the object control. Boys showed higher scores in striking, kicking, throwing, and rolling a ball. Quade's nonparametric analysis showed no difference in BMI between the genders. Most children presented healthy weight. The MANCOVA showed no effect of gender on children's scores on perceived competence on the subscales; moderate scores were found for most children. There were no gender effects on school performance; both boys and girls demonstrated inferior performance. Boys and girls in social vulnerability showed inferior performance in most motor skills, moderate perceived competence and inferior school performance. These results reveal that the appropriate development of these children is at risk and that intervention strategies should be implemented to compensate the difficulties presented. Copyright © 2018 Elsevier Ltd. All rights reserved.

Demography of SDSS Early-type Galaxies from the Perspective of Radial Color Gradients

NASA Astrophysics Data System (ADS)

Suh, Hyewon; Jeong, H.; Oh, K.; Yi, S. K.; Ferreras, I.; Schawinski, K.

2010-01-01

We have investigated the radial g-r color gradients of early-type galaxies in the Sloan Digital Sky Survey (SDSS) DR6 in the redshift range 0.00 < z < 0.06. The majority of massive early-type galaxies show a negative color gradient (centers being redder). On the other hand, roughly 30 percent of the galaxies in this sample show positive color gradients (centers being bluer). These positive-gradient galaxies often show strong Hβ absorption line strengths and/or emission line ratios that are consistent with containing young stellar populations. Combining the optical data with Galaxy Evolution Explorer (GALEX) UV photometry, we find that all positive-gradient galaxies show blue UV-optical colors. This implies that the residual star formation in early-type galaxies is centrally concentrated. These positive-gradient galaxies tend to live in lower density regions. They are also a bit more likely to have a late-type companion galaxy, hinting at a possible role of interactions with a gas-rich companion. A simplistic population analysis shows that these positive color gradients are visible only for half a billion years after a star burst. Moreover, the positive-gradient galaxies occupy different regions in the fundamental planes from the outnumbering negative-gradient galaxies. However, the positions of the positive-gradient galaxies on the fundamental planes cannot be attributed to any reasonable amount of recent star formation alone but require substantially lower velocity dispersions to begin with. Our results based on the optical data are consistent with the residual star formation interpretation which was based on the GALEX UV data. A low-level residual star formation seems continuing in most of the less-massive early-type galaxies in their centers.

Sex differences in how social networks and relationship quality influence experimental pain sensitivity.

PubMed

Vigil, Jacob M; Rowell, Lauren N; Chouteau, Simone; Chavez, Alexandre; Jaramillo, Elisa; Neal, Michael; Waid, David

2013-01-01

This is the first study to examine how both structural and functional components of individuals' social networks may moderate the association between biological sex and experimental pain sensitivity. One hundred and fifty-two healthy adults (mean age = 22yrs., 53% males) were measured for cold pressor task (CPT) pain sensitivity (i.e., intensity ratings) and core aspects of social networks (e.g., proportion of friends vs. family, affection, affirmation, and aid). Results showed consistent sex differences in how social network structures and intimate relationship functioning modulated pain sensitivity. Females showed higher pain sensitivity when their social networks consisted of a higher proportion of intimate types of relationship partners (e.g., kin vs. non kin), when they had known their network partners for a longer period of time, and when they reported higher levels of logistical support from their significant other (e.g., romantic partner). Conversely, males showed distinct patterns in the opposite direction, including an association between higher levels of logistical support from one's significant other and lower CPT pain intensity. These findings show for the first time that the direction of sex differences in exogenous pain sensitivity is likely dependent on fundamental components of the individual's social environment. The utility of a social-signaling perspective of pain behaviors for examining, comparing, and interpreting individual and group differences in experimental and clinical pain reports is discussed.

Sex Differences in How Social Networks and Relationship Quality Influence Experimental Pain Sensitivity

PubMed Central

Vigil, Jacob M.; Rowell, Lauren N.; Chouteau, Simone; Chavez, Alexandre; Jaramillo, Elisa; Neal, Michael; Waid, David

2013-01-01

This is the first study to examine how both structural and functional components of individuals’ social networks may moderate the association between biological sex and experimental pain sensitivity. One hundred and fifty-two healthy adults (mean age = 22yrs., 53% males) were measured for cold pressor task (CPT) pain sensitivity (i.e., intensity ratings) and core aspects of social networks (e.g., proportion of friends vs. family, affection, affirmation, and aid). Results showed consistent sex differences in how social network structures and intimate relationship functioning modulated pain sensitivity. Females showed higher pain sensitivity when their social networks consisted of a higher proportion of intimate types of relationship partners (e.g., kin vs. non kin), when they had known their network partners for a longer period of time, and when they reported higher levels of logistical support from their significant other (e.g., romantic partner). Conversely, males showed distinct patterns in the opposite direction, including an association between higher levels of logistical support from one’s significant other and lower CPT pain intensity. These findings show for the first time that the direction of sex differences in exogenous pain sensitivity is likely dependent on fundamental components of the individual’s social environment. The utility of a social-signaling perspective of pain behaviors for examining, comparing, and interpreting individual and group differences in experimental and clinical pain reports is discussed. PMID:24223836

Joint inversion of fundamental and higher mode Rayleigh waves

USGS Publications Warehouse

Luo, Y.-H.; Xia, J.-H.; Liu, J.-P.; Liu, Q.-S.

2008-01-01

In this paper, we analyze the characteristics of the phase velocity of fundamental and higher mode Rayleigh waves in a six-layer earth model. The results show that fundamental mode is more sensitive to the shear velocities of shallow layers (< 7 m) and concentrated in a very narrow band (around 18 Hz) while higher modes are more sensitive to the parameters of relatively deeper layers and distributed over a wider frequency band. These properties provide a foundation of using a multi-mode joint inversion to define S-wave velocity. Inversion results of both synthetic data and a real-world example demonstrate that joint inversion with the damped least squares method and the SVD (Singular Value Decomposition) technique to invert Rayleigh waves of fundamental and higher modes can effectively reduce the ambiguity and improve the accuracy of inverted S-wave velocities.

Multifractal analyis of soil invertebrates along a transect under different land uses

NASA Astrophysics Data System (ADS)

Machado Siqueira, Glécio; Alves Silva, Raimunda; Vidal-Vázquez, Eva; Paz-González, Antonio

2017-04-01

Soil fauna play a central role in many essential ecosystem processes. Land use and management can have a dramatic effect upon soil invertebrate community. Indices based on soil invertebrates abundance and diversity are fundamental for soil quality assessment. Many soil properties and attributes have been shown to exhibit spatial variabilityThe aim of this study was to analyze the scaling heterogeneity of the soil invertebrate community sampled using pitfall traps across a transect. The field study was conducted at Mata Roma municipality, Maranhão State, Brazil. Transects were marked under seven different agricultural/forestry land uses (millet, soybean, maize, eucalyptus, pasture, secondary savannah and native savannah). Native vegetation was considered as a reference, whereas the agricultural fields showed a range of soil use intensities. Along these transects 130 pitfall per land use were installed. First, differences in community assemblages and composition under different land use systems were evaluated using classical indices. Then, the spatial distribution of soil fauna trapped by pitfall techniques, characterized through generalized dimension, Dq, and singularity spectra, f(α) - α, showed a well-defined multifractal structure. Differences in scaling heterogeneity and other multifractal characteristics were examined in relation to land use intensification.

Comparative Analysis of the Tour Jete and Aerial with Detailed Analysis of Aerial Takeoff Mechanics

NASA Astrophysics Data System (ADS)

Pierson, Mimi; Coplin, Kim

2006-10-01

Whether internally as muscle tension or from external sources, forces are necessary for all motion. This research focused on athletic rotations where conditions of flight are established during takeoff. By studying reaction forces that produce torques, moments of inertia, and linear and angular differences between distinct rotations around different principle axes of the body (tour jete in ballet - longitudinal axis; aerial in gymnastics - anteroposterior axis), and by looking at the values of angular momentum in the specific mechanics of aerial takeoff, we can gain insight into possible causes of injury, flaws in technique and limitations of athletes. Results showed significant differences in the horizontal and vertical components of takeoff between the tour jete and the aerial, and a realization that torque was produced in different biomechanical planes. Both rotations showed braking forces before takeoff to counteract forward momentum and increase vertical lift, but the angle of applied force varied, and the horizontal components of velocity and force and vertical velocity as well as moment of inertia throughout flight were consistently greater for the aerial. Breakdown of aerial takeoff highlighted the relative importance of the takeoff phases, showing that completion depends fundamentally upon the rotation of the rear foot and torso twisting during takeoff rather than the last foot in contact with the ground.

The Identity-Location Binding Problem.

PubMed

Howe, Piers D L; Ferguson, Adam

2015-09-01

The binding problem is fundamental to visual perception. It is the problem of associating an object's visual properties with itself and not with some other object. The problem is made particular difficult because different properties of an object, such as its color, shape, size, and motion, are often processed independently, sometimes in different cortical areas. The results of these separate analyses have to be combined before the object can be seen as a single coherent entity as opposed to a collection of unconnected features. Visual bindings are typically initiated and updated in a serial fashion, one object at a time. Here, we show that one type of binding, location-identity bindings, can be updated in parallel. We do this by using two complementary techniques, the simultaneous-sequential paradigm and systems factorial technology. These techniques make different assumptions and rely on different behavioral measures, yet both came to the same conclusion. Copyright © 2014 Cognitive Science Society, Inc.

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

Medeiros, Brian; Williamson, David L.; Olson, Jerry G.

In this study, fundamental characteristics of the aquaplanet climate simulated by the Community Atmosphere Model, Version 5.3 (CAM5.3) are presented. The assumptions and simplifications of the configuration are described. A 16 year long, perpetual equinox integration with prescribed SST using the model’s standard 18 grid spacing is presented as a reference simulation. Statistical analysis is presented that shows similar aquaplanet configurations can be run for about 2 years to obtain robust climatological structures, including global and zonal means, eddy statistics, and precipitation distributions. Such a simulation can be compared to the reference simulation to discern differences in the climate, includingmore » an assessment of confidence in the differences. To aid such comparisons, the reference simulation has been made available via earthsystemgrid.org. Examples are shown comparing the reference simulation with simulations from the CAM5 series that make different microphysical assumptions and use a different dynamical core.« less

Reference aquaplanet climate in the Community Atmosphere Model, Version 5

DOE PAGES

Medeiros, Brian; Williamson, David L.; Olson, Jerry G.

2016-03-18

In this study, fundamental characteristics of the aquaplanet climate simulated by the Community Atmosphere Model, Version 5.3 (CAM5.3) are presented. The assumptions and simplifications of the configuration are described. A 16 year long, perpetual equinox integration with prescribed SST using the model’s standard 18 grid spacing is presented as a reference simulation. Statistical analysis is presented that shows similar aquaplanet configurations can be run for about 2 years to obtain robust climatological structures, including global and zonal means, eddy statistics, and precipitation distributions. Such a simulation can be compared to the reference simulation to discern differences in the climate, includingmore » an assessment of confidence in the differences. To aid such comparisons, the reference simulation has been made available via earthsystemgrid.org. Examples are shown comparing the reference simulation with simulations from the CAM5 series that make different microphysical assumptions and use a different dynamical core.« less

Acoustic Analyses of the Singing Vibrato in Traditional Peking Opera.

PubMed

Han, Qichao; Zhang, Ruifeng

2017-07-01

China's traditional Peking Opera has four standard categories of roles: Sheng, Dan, Jing, and Chou, the singing vibrato of each displaying a different auditory effect. The audio and respiratory signals were recorded for two performers of the Qing Yi role, one of the Jing role, one of the Chou role, one of the Lao Sheng role, one of the Xiao Sheng role, and one of the Lao Dan role. The recordings gained eventually consisted of 24 representative songs from six roles. The rates and extents of vibrato, fundamental frequency, and rib cage signals were analyzed. Two findings were obtained: (1) the classical opera singing vibratos of China and Western countries are acoustically different from each other; and (2) in Peking Opera, the singing vibratos of different roles show significant acoustic differences. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Voice Register in Mon: Acoustics and Electroglottography

PubMed Central

Abramson, Arthur S.; Tiede, Mark K.; Luangthongkum, Theraphan

2016-01-01

Mon is spoken in villages in Thailand and Myanmar. The dialect of Ban Nakhonchum, Thailand has two voice registers, modal and breathy; these phonation types, along with other phonetic properties, distinguish minimal pairs. Four native speakers of this dialect recorded repetitions of 14 randomized words (seven minimal pairs) for acoustic analysis. We used a subset of these pairs in a listening test to verify the perceptual robustness of the register distinction. Acoustic analysis found significant differences in noise component, spectral slope, and fundamental frequency. In a subsequent session four speakers were also recorded using electroglottography (EGG), which showed systematic differences in the contact quotient (CQ). The salience of these properties in maintaining the register distinction is discussed in the context of possible tonogenesis for this language. PMID:26636544

Thermodynamical effects and high resolution methods for compressible fluid flows

NASA Astrophysics Data System (ADS)

Li, Jiequan; Wang, Yue

2017-08-01

One of the fundamental differences of compressible fluid flows from incompressible fluid flows is the involvement of thermodynamics. This difference should be manifested in the design of numerical schemes. Unfortunately, the role of entropy, expressing irreversibility, is often neglected even though the entropy inequality, as a conceptual derivative, is verified for some first order schemes. In this paper, we refine the GRP solver to illustrate how the thermodynamical variation is integrated into the design of high resolution methods for compressible fluid flows and demonstrate numerically the importance of thermodynamic effects in the resolution of strong waves. As a by-product, we show that the GRP solver works for generic equations of state, and is independent of technical arguments.

Laughter differs in children with autism: an acoustic analysis of laughs produced by children with and without the disorder.

PubMed

Hudenko, William J; Stone, Wendy; Bachorowski, Jo-Anne

2009-10-01

Few studies have examined vocal expressions of emotion in children with autism. We tested the hypothesis that during social interactions, children diagnosed with autism would exhibit less extreme laugh acoustics than their nonautistic peers. Laughter was recorded during a series of playful interactions with an examiner. Results showed that children with autism exhibited only one type of laughter, whereas comparison participants exhibited two types. No group differences were found for laugh duration, mean fundamental frequency (F(0)) values, change in F(0), or number of laughs per bout. Findings are interpreted to suggest that children with autism express laughter primarily in response to positive internal states, rather than using laughter to negotiate social interactions.

Changing the Spatial Scope of Attention Alters Patterns of Neural Gain in Human Cortex

PubMed Central

Garcia, Javier O.; Rungratsameetaweemana, Nuttida; Sprague, Thomas C.

2014-01-01

Over the last several decades, spatial attention has been shown to influence the activity of neurons in visual cortex in various ways. These conflicting observations have inspired competing models to account for the influence of attention on perception and behavior. Here, we used electroencephalography (EEG) to assess steady-state visual evoked potentials (SSVEP) in human subjects and showed that highly focused spatial attention primarily enhanced neural responses to high-contrast stimuli (response gain), whereas distributed attention primarily enhanced responses to medium-contrast stimuli (contrast gain). Together, these data suggest that different patterns of neural modulation do not reflect fundamentally different neural mechanisms, but instead reflect changes in the spatial extent of attention. PMID:24381272

Quantification of network structural dissimilarities.

PubMed

Schieber, Tiago A; Carpi, Laura; Díaz-Guilera, Albert; Pardalos, Panos M; Masoller, Cristina; Ravetti, Martín G

2017-01-09

Identifying and quantifying dissimilarities among graphs is a fundamental and challenging problem of practical importance in many fields of science. Current methods of network comparison are limited to extract only partial information or are computationally very demanding. Here we propose an efficient and precise measure for network comparison, which is based on quantifying differences among distance probability distributions extracted from the networks. Extensive experiments on synthetic and real-world networks show that this measure returns non-zero values only when the graphs are non-isomorphic. Most importantly, the measure proposed here can identify and quantify structural topological differences that have a practical impact on the information flow through the network, such as the presence or absence of critical links that connect or disconnect connected components.

Entanglement dynamics in itinerant fermionic and bosonic systems

NASA Astrophysics Data System (ADS)

Pillarishetty, Durganandini

2017-04-01

The concept of quantum entanglement of identical particles is fundamental in a wide variety of quantum information contexts involving composite quantum systems. However, the role played by particle indistinguishabilty in entanglement determination is being still debated. In this work, we study, theoretically, the entanglement dynamics in some itinerant bosonic and fermionic systems. We show that the dynamical behaviour of particle entanglement and spatial or mode entanglement are in general different. We also discuss the effect of fermionic and bosonic statistics on the dynamical behaviour. We suggest that the different dynamical behaviour can be used to distinguish between particle and mode entanglement in identical particle systems and discuss possible experimental realizations for such studies. I acknowledge financial support from DST, India through research Grant.

A comparison between space-time video descriptors

NASA Astrophysics Data System (ADS)

Costantini, Luca; Capodiferro, Licia; Neri, Alessandro

2013-02-01

The description of space-time patches is a fundamental task in many applications such as video retrieval or classification. Each space-time patch can be described by using a set of orthogonal functions that represent a subspace, for example a sphere or a cylinder, within the patch. In this work, our aim is to investigate the differences between the spherical descriptors and the cylindrical descriptors. In order to compute the descriptors, the 3D spherical and cylindrical Zernike polynomials are employed. This is important because both the functions are based on the same family of polynomials, and only the symmetry is different. Our experimental results show that the cylindrical descriptor outperforms the spherical descriptor. However, the performances of the two descriptors are similar.

Schools Need Leaders--Not Managers: It's Time for a Paradigm Shift

ERIC Educational Resources Information Center

Stein, Les

2016-01-01

In the world of public school education everything depends on good leadership. Sadly, many of our schools administrators can't differentiate the difference between leading and managing; far too many of them don't know the first thing about fundamental leadership principles. In short, they don't understand the fundamentals of Mission Oriented…

Educational Influences on Young People's Support for Fundamental British Values

ERIC Educational Resources Information Center

Janmaat, Jan Germen

2018-01-01

In 2014 the British government called on schools to actively promote fundamental British values (FBVs), seeing this as an effective way to prevent the radicalisation of young people. The government considers these values to include democracy, individual liberty, the rule of law and respect for people of different backgrounds and religions. Rather…

Stem cell biobanks.

PubMed

Bardelli, Silvana

2010-04-01

Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

Sex Differences in Fundamental Movement Skills of a Selected Group of 6-Year-Old South African Children

ERIC Educational Resources Information Center

Pienaar, Anita E.; van Reenen, Irma; Weber, Angelique M.

2016-01-01

Background: Motor competence is emerging as an important marker of health, while adequate basic movement patterns, body control and body awareness are important building blocks of more specialized body movements and scholastic adjustment during early childhood. This study examined fundamental movement skill competency and explored sex differences…

Education of Women in Islam: A Critical Islamic Interpretation of the Quran

ERIC Educational Resources Information Center

Abukari, Abdulai

2014-01-01

In Islam, knowledge, its acquisition and application is a fundamental requirement for all Muslims to enable them to believe, think, and act according to the principles of the religion. However, differences in style of interpretation of the Qur'an have led to text being interpreted against its own fundamental worldview; an example is the…

A fundamental residue pitch perception bias for tone language speakers

NASA Astrophysics Data System (ADS)

Petitti, Elizabeth

A complex tone composed of only higher-order harmonics typically elicits a pitch percept equivalent to the tone's missing fundamental frequency (f0). When judging the direction of residue pitch change between two such tones, however, listeners may have completely opposite perceptual experiences depending on whether they are biased to perceive changes based on the overall spectrum or the missing f0 (harmonic spacing). Individual differences in residue pitch change judgments are reliable and have been associated with musical experience and functional neuroanatomy. Tone languages put greater pitch processing demands on their speakers than non-tone languages, and we investigated whether these lifelong differences in linguistic pitch processing affect listeners' bias for residue pitch. We asked native tone language speakers and native English speakers to perform a pitch judgment task for two tones with missing fundamental frequencies. Given tone pairs with ambiguous pitch changes, listeners were asked to judge the direction of pitch change, where the direction of their response indicated whether they attended to the overall spectrum (exhibiting a spectral bias) or the missing f0 (exhibiting a fundamental bias). We found that tone language speakers are significantly more likely to perceive pitch changes based on the missing f0 than English speakers. These results suggest that tone-language speakers' privileged experience with linguistic pitch fundamentally tunes their basic auditory processing.

Fundamentals of Adaptive Intelligent Tutoring Systems for Self-Regulated Learning

DTIC Science & Technology

2015-03-01

has 4 fundamental elements: a learner model, a pedagogical (instructional) model, a domain model, and a communication model. Figure 5 shows a...The TUI has been discussed in detail, so now the learner, pedagogical , and domain modules will be reviewed:  Learner module. In addition to...shared states, which are provided to the pedagogical module.  Pedagogical module. The pedagogical module models the instructional techniques

Continuity or Discontinuity? Scientific Governance in the Pre-History of the 1977 Law of Higher Education and Research in Sweden

ERIC Educational Resources Information Center

Bragesjo, Fredrik; Elzinga, Aant; Kasperowski, Dick

2012-01-01

The objective of this paper is to balance two major conceptual tendencies in science policy studies, continuity and discontinuity theory. While the latter argue for fundamental and distinct changes in science policy in the late 20th century, continuity theorists show how changes do occur but not as abrupt and fundamental as discontinuity theorists…

Anharmonic calculations of frequencies and intensities of Osbnd H stretching vibrations of (R)-1,3-butanediol conformers in the fundamentals and first overtones by density functional theory

NASA Astrophysics Data System (ADS)

Futami, Yoshisuke; Minamoto, Chihiro; Kudoh, Satoshi

2018-05-01

The frequencies and absorption intensities of the five kinds of conformers of 1,3-butanediol with the same carbon skeleton (GG‧) were calculated by anharmonic calculation for the fundamentals and first overtones of OH stretching vibrations. The four kinds of conformers form intramolecular hydrogen bonds and one conformer did not. Intramolecular hydrogen bond formation shifted the frequency of fundamental and first overtone of H-bonding OH stretching vibration to the lower frequency. The absorption intensities of the fundamentals as well as the vibrational anharmonicities increased upon hydrogen bond formation, while the intensities of first overtones decreased. The differences of conformers were clearly seen in the frequencies of the first overtones of free OH.

Plans and Preliminary Results of Fundamental Studies of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory

NASA Technical Reports Server (NTRS)

Struk, Peter; Tsao, Jen-Ching; Bartkus, Tadas

2017-01-01

This paper describes plans and preliminary results for using the NASA Propulsion Systems Lab (PSL) to experimentally study the fundamental physics of ice-crystal ice accretion. NASA is evaluating whether this facility, in addition to full-engine and motor-driven-rig tests, can be used for more fundamental ice-accretion studies that simulate the different mixed-phase icing conditions along the core flow passage of a turbo-fan engine compressor. The data from such fundamental accretion tests will be used to help develop and validate models of the accretion process. This paper presents data from some preliminary testing performed in May 2015 which examined how a mixed-phase cloud could be generated at PSL using evaporative cooling in a warmer-than-freezing environment.

Plans and Preliminary Results of Fundamental Studies of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory

NASA Technical Reports Server (NTRS)

Struk, Peter; Tsao, Jen-Ching; Bartkus, Tadas

2016-01-01

This presentation accompanies the paper titled Plans and Preliminary Results of Fundamental Studies of Ice Crystal Icing Physics in the NASA Propulsion Systems Laboratory. NASA is evaluating whether PSL, in addition to full-engine and motor-driven-rig tests, can be used for more fundamental ice-accretion studies that simulate the different mixed-phase icing conditions along the core flow passage of a turbo-fan engine compressor. The data from such fundamental accretion tests will be used to help develop and validate models of the accretion process. This presentation (and accompanying paper) presents data from some preliminary testing performed in May 2015 which examined how a mixed-phase cloud could be generated at PSL using evaporative cooling in a warmer-than-freezing environment.

Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning

PubMed Central

Carl Aberg, Kristoffer; Doell, Kimberly C.; Schwartz, Sophie

2016-01-01

Learning how to gain rewards (approach learning) and avoid punishments (avoidance learning) is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance) learning scored higher on measures of approach (vs. avoidance) trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative) outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits. PMID:27851807

Social curiosity and gossip: related but different drives of social functioning.

PubMed

Hartung, Freda-Marie; Renner, Britta

2013-01-01

The present online-questionnaire study examined two fundamental social behaviors, social curiosity and gossip, and their interrelations in an English (n = 218) and a German sample (n = 152). Analyses showed that both samples believed that they are less gossipy but more curious than their peers. Multidimensional SEM of self and trait conceptions indicated that social curiosity and gossip are related constructs but with different patterns of social functions. Gossip appears to serve predominantly entertainment purposes whereas social curiosity appears to be more driven by a general interest in gathering information about how other people feel, think, and behave and the need to belong. Relationships to other personality traits (N, E, O) provided additional evidence for divergent validity. The needs for gathering and disseminating social information might represent two interlinked but different drives of cultural learning.

Social Curiosity and Gossip: Related but Different Drives of Social Functioning

PubMed Central

Hartung, Freda-Marie; Renner, Britta

2013-01-01

The present online-questionnaire study examined two fundamental social behaviors, social curiosity and gossip, and their interrelations in an English (n = 218) and a German sample (n = 152). Analyses showed that both samples believed that they are less gossipy but more curious than their peers. Multidimensional SEM of self and trait conceptions indicated that social curiosity and gossip are related constructs but with different patterns of social functions. Gossip appears to serve predominantly entertainment purposes whereas social curiosity appears to be more driven by a general interest in gathering information about how other people feel, think, and behave and the need to belong. Relationships to other personality traits (N, E, O) provided additional evidence for divergent validity. The needs for gathering and disseminating social information might represent two interlinked but different drives of cultural learning. PMID:23936130

From High Intellectual Potential to Asperger Syndrome: Evidence for Differences and a Fundamental Overlap-A Systematic Review.

PubMed

Boschi, Aurélie; Planche, Pascale; Hemimou, Cherhazad; Demily, Caroline; Vaivre-Douret, Laurence

2016-01-01

Background: An increasing number of clinicians point to similar clinical features between some children with High Intellectual Potential (HIP or "Giftedness" = Total IQ > 2 SD ), and children with Autism Spectrum Disorder (ASD) without intellectual or language delay, formerly diagnosed with Asperger Syndrome. Some of these common features are social interaction impairments, special interests, and in some cases high-verbal abilities. The aim of this article is to determine whether these similarities exist at more fundamental levels, other than clinical, and to explore the literature in order to provide empirical support for an overlap between ASD and HIP. Method: First, comparative studies between ASD and HIP children were sought. Because of a lack of data, the respective characteristics of ASD and HIP subjects were explored by a cross-sectional review of different areas of research. Emphasis was placed on psychometric and cognitive evaluations, experimental and developmental assessments, and neurobiological research, following a "bottom-up" procedure. Results: This review highlights the existence of similarities in the neurocognitive, developmental and neurobiological domains between these profiles, which require further study. In addition, the conclusions of several studies show that there are differences between HIP children with a homogeneous Intellectual Quotient profile and children with a heterogeneous Intellectual Quotient profile. Conclusion: HIP seems to cover different developmental profiles, one of which might share features with ASD. A new line of investigation providing a possible starting-point for future research is proposed. Its implications, interesting from both clinical and research perspectives, are discussed.

From High Intellectual Potential to Asperger Syndrome: Evidence for Differences and a Fundamental Overlap—A Systematic Review

PubMed Central

Boschi, Aurélie; Planche, Pascale; Hemimou, Cherhazad; Demily, Caroline; Vaivre-Douret, Laurence

2016-01-01

Background: An increasing number of clinicians point to similar clinical features between some children with High Intellectual Potential (HIP or “Giftedness” = Total IQ > 2 SD), and children with Autism Spectrum Disorder (ASD) without intellectual or language delay, formerly diagnosed with Asperger Syndrome. Some of these common features are social interaction impairments, special interests, and in some cases high-verbal abilities. The aim of this article is to determine whether these similarities exist at more fundamental levels, other than clinical, and to explore the literature in order to provide empirical support for an overlap between ASD and HIP. Method: First, comparative studies between ASD and HIP children were sought. Because of a lack of data, the respective characteristics of ASD and HIP subjects were explored by a cross-sectional review of different areas of research. Emphasis was placed on psychometric and cognitive evaluations, experimental and developmental assessments, and neurobiological research, following a “bottom-up” procedure. Results: This review highlights the existence of similarities in the neurocognitive, developmental and neurobiological domains between these profiles, which require further study. In addition, the conclusions of several studies show that there are differences between HIP children with a homogeneous Intellectual Quotient profile and children with a heterogeneous Intellectual Quotient profile. Conclusion: HIP seems to cover different developmental profiles, one of which might share features with ASD. A new line of investigation providing a possible starting-point for future research is proposed. Its implications, interesting from both clinical and research perspectives, are discussed. PMID:27812341

Diffusion-controlled reference material for VOC emissions testing: proof of concept.

PubMed

Cox, S S; Liu, Z; Little, J C; Howard-Reed, C; Nabinger, S J; Persily, A

2010-10-01

Because of concerns about indoor air quality, there is growing awareness of the need to reduce the rate at which indoor materials and products emit volatile organic compounds (VOCs). To meet consumer demand for low emitting products, manufacturers are increasingly submitting materials to independent laboratories for emissions testing. However, the same product tested by different laboratories can result in very different emissions profiles because of a general lack of test validation procedures. There is a need for a reference material that can be used as a known emissions source and that will have the same emission rate when tested by different laboratories under the same conditions. A reference material was created by loading toluene into a polymethyl pentene film. A fundamental emissions model was used to predict the toluene emissions profile. Measured VOC emissions profiles using small-chamber emissions tests compared reasonably well to the emissions profile predicted using the emissions model, demonstrating the feasibility of the proposed approach to create a diffusion-controlled reference material. To calibrate emissions test chambers and improve the reproducibility of VOC emission measurements among different laboratories, a reference material has been created using a polymer film loaded with a representative VOC. Initial results show that the film's VOC emission profile measured in a conventional test chamber compares well to predictions based on independently determined material/chemical properties and a fundamental emissions model. The use of such reference materials has the potential to build consensus and confidence in emissions testing as well as 'level the playing field' for product testing laboratories and manufacturers.

Fault-related clay authigenesis along the Moab Fault: Implications for calculations of fault rock composition and mechanical and hydrologic fault zone properties

USGS Publications Warehouse

Solum, J.G.; Davatzes, N.C.; Lockner, D.A.

2010-01-01

The presence of clays in fault rocks influences both the mechanical and hydrologic properties of clay-bearing faults, and therefore it is critical to understand the origin of clays in fault rocks and their distributions is of great importance for defining fundamental properties of faults in the shallow crust. Field mapping shows that layers of clay gouge and shale smear are common along the Moab Fault, from exposures with throws ranging from 10 to ???1000 m. Elemental analyses of four locations along the Moab Fault show that fault rocks are enriched in clays at R191 and Bartlett Wash, but that this clay enrichment occurred at different times and was associated with different fluids. Fault rocks at Corral and Courthouse Canyons show little difference in elemental composition from adjacent protolith, suggesting that formation of fault rocks at those locations is governed by mechanical processes. Friction tests show that these authigenic clays result in fault zone weakening, and potentially influence the style of failure along the fault (seismogenic vs. aseismic) and potentially influence the amount of fluid loss associated with coseismic dilation. Scanning electron microscopy shows that authigenesis promotes that continuity of slip surfaces, thereby enhancing seal capacity. The occurrence of the authigenesis, and its influence on the sealing properties of faults, highlights the importance of determining the processes that control this phenomenon. ?? 2010 Elsevier Ltd.

Surface hydration amplifies single-well protein atom diffusion propagating into the macromolecular core

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

Hong, Liang; Cheng, Xiaolin; Glass, Dennis C.

2012-06-05

The effect of surface hydration water on internal protein motion is of fundamental interest in molecular biophysics. Here, by decomposing the picosecond to nanosecond atomic motion in molecular dynamics simulations of lysozyme at different hydration levels into three components localized single-well diffusion, methyl group rotation, and nonmethyl jumps we show that the effect of surface hydration is mainly to increase the volume of the localized single-well diffusion. As a result, these diffusive motions are coupled in such a way that the hydration effect propagates from the protein surface into the dry core.

A scaling law derived from optimal dendritic wiring

PubMed Central

Cuntz, Hermann; Mathy, Alexandre; Häusser, Michael

2012-01-01

The wide diversity of dendritic trees is one of the most striking features of neural circuits. Here we develop a general quantitative theory relating the total length of dendritic wiring to the number of branch points and synapses. We show that optimal wiring predicts a 2/3 power law between these measures. We demonstrate that the theory is consistent with data from a wide variety of neurons across many different species and helps define the computational compartments in dendritic trees. Our results imply fundamentally distinct design principles for dendritic arbors compared with vascular, bronchial, and botanical trees. PMID:22715290

[Analysis of expectations on the nurse's leadership in the light of Grid's theories].

PubMed

Trevizan, M A; Mendes, I A; Hayashida, M; Galvão, C M; Cury, S R

2001-01-01

Based on the understanding that leadership is a fundamental resource for nurses in health institutions, the aim of the authors was to analyze, under the light of Blake & Mouton's Grid Theories, the expectations of the Nursing team regarding nurse's leadership. The analysis was based on four investigations performed in different contexts of Brazilian Nursing and data were collected through the application of the "Grid & Leadership in Nursing Instrument" developed by Trevizan. Results show that the subjects prefer the Grid style 9.9. The authors discuss the results and emphasize the need for the development of leadership in Nursing.

Targeting gender: A content analysis of alcohol advertising in magazines.

PubMed

Jung, A-Reum; Hovland, Roxanne

2016-01-01

Creating target specific advertising is fundamental to maximizing advertising effectiveness. When crafting an advertisement, message and creative strategies are considered important because they affect target audiences' attitudes toward advertised products. This study endeavored to find advertising strategies that are likely to have special appeal for men or women by examining alcohol advertising in magazines. The results show that the substance of the messages is the same for men and women, but they only differ in terms of presentation. However, regardless of gender group, the most commonly used strategies in alcohol advertising are appeals to the target audience's emotions.

Topological defects in two-dimensional liquid crystals confined by a box

NASA Astrophysics Data System (ADS)

Yao, Xiaomei; Zhang, Hui; Chen, Jeff Z. Y.

2018-05-01

When a spatially uniform system that displays a liquid-crystal ordering on a two-dimensional surface is confined inside a rectangular box, the liquid crystal direction field develops inhomogeneous textures accompanied by topological defects because of the geometric frustrations. We show that the rich variety of nematic textures and defect patterns found in recent experimental and theoretical studies can be classified by the solutions of the rather fundamental, extended Onsager model. This is critically examined based on the determined free energies of different defect states, as functions of a few relevant, dimensionless geometric parameters.

Sibling species in Montastraea annularis, coral bleaching, and the coral climate record

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

Knowlton, N.; Weil, E.; Weigt, L.A.

1992-01-17

Measures of growth and skeletal isotopic ratios in the Caribbean coral Montastraea annularis are fundamental to many studies of paleoceanography, environmental degradation, and global climate change. This taxon is shown to consist of at least three sibling species in shallow water. The two most commonly studied of these show highly significant differences in growth rate and oxygen isotopic ratios, parameters routinely used to estimate past climatic conditions; unusual coloration in the third may have confused research on coral bleaching. Interpretation or comparison of past and current studies can be jeopardized by ignoring these species boundaries.

Biomarkers and Targeted Therapy in Pancreatic Cancer.

PubMed

Karandish, Fataneh; Mallik, Sanku

2016-01-01

Pancreatic ductal adenocarcinoma (PDAC) constitutes 90% of pancreatic cancers. PDAC is a complex and devastating disease with only 1%-3% survival rate in five years after the second stage. Treatment of PDAC is complicated due to the tumor microenvironment, changing cell behaviors to the mesenchymal type, altered drug delivery, and drug resistance. Considering that pancreatic cancer shows early invasion and metastasis, critical research is needed to explore different aspects of the disease, such as elaboration of biomarkers, specific signaling pathways, and gene aberration. In this review, we highlight the biomarkers, the fundamental signaling pathways, and their importance in targeted drug delivery for pancreatic cancers.

Do focal colors look particularly "colorful"?

PubMed

Witzel, Christoph; Franklin, Anna

2014-04-01

If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

Non-Standard Gearing as the Possibility of Increasing Resistance to Pitting

NASA Astrophysics Data System (ADS)

Kopiláková, Beáta; Bošanský, Miroslav

2014-12-01

In this article are shown the influence of the type non-standard gearing to reduce damage to the pitting. The introduction of the article describes a fundamental difference between the involute and non-involute gearing and the influence of some parameters, especially of the slip ratio to damage of gearing. The paper describes the principle of evaluation pitting by makrofoto graphical method, too and also shows the basic results of the experiment, which was executed on two types of gearing (HCR gearing and C-C gearing) on the Niemanńs stend in term of the damage to pitting.

Observation of orbital angular momentum transfer between acoustic and optical vortices in optical fiber.

PubMed

Dashti, Pedram Z; Alhassen, Fares; Lee, Henry P

2006-02-03

Acousto-optic interaction in optical fiber is examined from the perspective of copropagating optical and acoustic vortex modes. Calculation of the acousto-optic coupling coefficient between different optical modes leads to independent conservation of spin and orbital angular momentum of the interacting photons and phonons. We show that the orbital angular momentum of the acoustic vortex can be transferred to a circularly polarized fundamental optical mode to form a stable optical vortex in the fiber carrying orbital angular momentum. The technique provides a useful way of generating stable optical vortices in the fiber medium.

Ethical principles in health research and review process.

PubMed

Tangwa, Godfrey B

2009-11-01

In this paper I want to reflect on the fundamental ethical principles and their application in different particular contexts, especially in health research and the ethics review process. Four fundamental ethical principles have been identified and widely discussed in bioethical literature. These principles namely are: autonomy or respect for others, beneficence, non-maleficence and justice. These principles have cross-cultural validity, relevance and applicability. Every real-life situation and every concrete particular case in which ethical decision-making is called-for is unique and different from all others; but the same fundamental ethical principles are relevant and used in addressing all such cases and situations. Very often ethical problems will present themselves in the form of dilemmas and it is then necessary to use the same fundamental principles to analyze the situations, to argue persuasively and cogently with competence for the best options or choices in such situations. The issues I will be dealing with in this paper are necessarily more abstract and theoretical, but we will be discussing them from a very practical viewpoint and impulse, with a view to application in concrete real-life situations. The paper ends with some sample practical examples of cases that the reader can use to test his/her grasp of the principles, how to apply them, how to balance them in differing situations and contexts and how to adjudicate between them when they seem to be in conflict.

Stereotypic Laryngeal and Respiratory Motor Patterns Generate Different Call Types in Rat Ultrasound Vocalization

PubMed Central

RIEDE, TOBIAS

2014-01-01

Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The role of larynx muscles in controlling sound features across different call types in ultrasound vocalization (USV) was investigated using laryngeal muscle electromyographic (EMG) activity, subglottal pressure measurements and vocal sound output in awake and spontaneously behaving Sprague–Dawley rats. Results support the hypothesis that glottal shape determines fundamental frequency. EMG activities of thyroarytenoid and cricothyroid muscles were aligned with call duration. EMG intensity increased with fundamental frequency. Phasic activities of both muscles were aligned with fast changing fundamental frequency contours, for example in trills. Activities of the sternothyroid and sternohyoid muscles, two muscles involved in vocal production in other mammals, are not critical for the production of rat USV. To test how stereotypic laryngeal and respiratory activity are across call types and individuals, sets of ten EMG and subglottal pressure parameters were measured in six different call types from six rats. Using discriminant function analysis, on average 80% of parameter sets were correctly assigned to their respective call type. This was significantly higher than the chance level. Since fundamental frequency features of USV are tightly associated with stereotypic activity of intrinsic laryngeal muscles and muscles contributing to build-up of subglottal pressure, USV provide insight into the neurophysiological control of peripheral vocal motor patterns. PMID:23423862

Exploring Fold Space Preferences of New-born and Ancient Protein Superfamilies

PubMed Central

Edwards, Hannah; Abeln, Sanne; Deane, Charlotte M.

2013-01-01

The evolution of proteins is one of the fundamental processes that has delivered the diversity and complexity of life we see around ourselves today. While we tend to define protein evolution in terms of sequence level mutations, insertions and deletions, it is hard to translate these processes to a more complete picture incorporating a polypeptide's structure and function. By considering how protein structures change over time we can gain an entirely new appreciation of their long-term evolutionary dynamics. In this work we seek to identify how populations of proteins at different stages of evolution explore their possible structure space. We use an annotation of superfamily age to this space and explore the relationship between these ages and a diverse set of properties pertaining to a superfamily's sequence, structure and function. We note several marked differences between the populations of newly evolved and ancient structures, such as in their length distributions, secondary structure content and tertiary packing arrangements. In particular, many of these differences suggest a less elaborate structure for newly evolved superfamilies when compared with their ancient counterparts. We show that the structural preferences we report are not a residual effect of a more fundamental relationship with function. Furthermore, we demonstrate the robustness of our results, using significant variation in the algorithm used to estimate the ages. We present these age estimates as a useful tool to analyse protein populations. In particularly, we apply this in a comparison of domains containing greek key or jelly roll motifs. PMID:24244135

Applying tribology to teeth of hoofed mammals.

PubMed

Schulz, Ellen; Calandra, Ivan; Kaiser, Thomas M

2010-01-01

Mammals inhabit all types of environments and have evolved chewing systems capable of processing a huge variety of structurally diverse food components. Surface textures of cheek teeth should thus reflect the mechanisms of wear as well as the functional traits involved. We employed surface textures parameters from ISO/DIS 25178 and scale-sensitive fractal analysis (SSFA) to quantify dental wear in herbivorous mammals at the level of an individual wear enamel facet. We evaluated cheek dentitions of two grazing ungulates: the Blue Wildebeest (Connochaetes taurinus) and the Grevy's Zebra (Equus grevyi). Both inhabit the east African grassland savanna habitat, but they belong to fundamentally different taxonomic units. We tested the hypothesis that the foregut fermenting wildebeest and the hindgut fermenting zebra show functional traits in their dentitions that relate to their specific mode of food-composition processing and digestion. In general, surface texture parameters from SSFA as well as ISO/DIS 25178 indicated that individual enamel ridges acting as crushing blades and individual wear facets of upper cheek teeth are significantly different in surface textures in the zebra when compared with the wildebeest. We interpreted the complexity and anisotropy signals to be clearly related to the brittle, dry grass component in the diet of the zebra, unlike the wildebeest, which ingests a more heterogeneous diet including fresh grass and herbs. Thus, SSFA and ISO parameters allow distinctions within the subtle dietary strategies that evolved in herbivorous ungulates with fundamentally different systematic affinities but which exploit a similar dietary niche. © 2010 Wiley Periodicals, Inc.

Somatic copy number alterations in gastric adenocarcinomas among Asian and Western patients

PubMed Central

Corso, Giovanni; Ryu, Min-Hee; Kang, Yoon-Koo; Roviello, Franco; Saksena, Gordon; Peng, Shouyong; Shivdasani, Ramesh A.; Bass, Adam J.; Beroukhim, Rameen

2017-01-01

Gastric cancer, a leading worldwide cause of cancer mortality, shows high geographic and ethnic variation in incidence rates, which are highest in East Asia. The anatomic locations and clinical behavior also differ by geography, leading to the controversial idea that Eastern and Western forms of the disease are distinct. In view of these differences, we investigated whether gastric cancers from Eastern and Western patients show distinct genomic profiles. We used high-density profiling of somatic copy-number aberrations to analyze the largest collection to date of gastric adenocarcinomas and utilized genotyping data to rigorously annotate ethnic status. The size of this collection allowed us to accurately identify regions of significant copy-number alteration and separately to evaluate tumors arising in Eastern and Western patients. Among molecular subtypes classified by The Cancer Genome Atlas, the frequency of gastric cancers showing chromosomal instability was modestly higher in Western patients. After accounting for this difference, however, gastric cancers arising in Easterners and Westerners have highly similar somatic copy-number patterns. Only one genomic event, focal deletion of the phosphatase gene PTPRD, was significantly enriched in Western cases, though also detected in Eastern cases. Thus, despite the different risk factors and clinical features, gastric cancer appears to be a fundamentally similar disease in both populations and the divergent clinical outcomes cannot be ascribed to different underlying structural somatic genetic aberrations. PMID:28426752

Fundamental Frequency of Crying in Two-month-old Boys and Girls: Do Sex Hormones During Mini-puberty Mediate Differences?

PubMed

Borysiak, Anja; Hesse, Volker; Wermke, Peter; Hain, Johannes; Robb, Michael; Wermke, Kathleen

2017-01-01

To evaluate whether the puberty-like sex hormone surge during the first months of life (mini-puberty) affects fundamental frequency (fo) in infant crying as one would derive from hormone influences on voice in adults. Populational prospective study. Twenty healthy normal-hearing infants (nine boys) were recruited for participation. Spontaneously uttered cries were collected from each infant at 8 weeks of age. The cries were acoustically analyzed for mean fo and fo range. The fo properties were correlated to the average serum levels of bioavailable estradiol (E2) (mean E2/sex hormone-binding globulin [SHBG]) and testosterone (T) (mean T/SHBG) across the second month of life. Whereas no significant hormone effect was found for mean fo, a significant negative correlation (r = -0.55) was found between fo range and mean E2/SHBG. No indication for a T influence on fo features was found at this age. Although girls showed a slightly higher mean E2 concentration than boys did, the observed differences in cry fo range were judged to be reflective of an infant's serum concentration of E2 rather than a sex-based difference. In the absence of laryngeal size differences between female and male infants, the result was interpreted as indicative of an E2 influence on viscoelastic properties of the vocal folds. In our opinion, the investigation of young infants' vocalizations during the early postnatal surge of sex steroids (mini-puberty) may advance our understanding of the mechanisms mediating average sex differences in vocal development and early communication. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Standardized laryngeal videostroboscopic rating: differences between untrained and trained male and female subjects, and effects of varying sound intensity, fundamental frequency, and age.

PubMed

Sulter, A M; Schutte, H K; Miller, D G

1996-06-01

To determine the influence of the factors gender, vocal training, sound intensity, pitch, and aging on vocal function, videolaryngostroboscopic images of 214 subjects, subdivided according to gender and status of vocal training, were evaluated by three judges with standardized rating scales, comprising aspects of laryngeal appearance (larynx/pharynx ratio; epiglottal shape; asymmetry arytenoid region; compensatory adjustments; thickness, width, length, and elasticity of vocal folds) and glottal functioning (amplitudes of excursion; duration, percentage, and type of vocal fold closure; phase differences; location of glottal chink). The video registrations were made while the subjects performed a set of phonatory tasks, comprising the utterance of the vowel /i/ at three levels of both fundamental frequency and sound intensity. Analysis of the rating scales showed generally sufficient agreement among judges. With the exception of more frequently observed complete closure and lateral phase differences of vocal fold excursions in trained subjects, no further differences were established between untrained and trained subjects. With an alpha level of p = 0.005, men differed from women with respect to laryngeal appearance (larynx/pharynx ratio, compensatory adjustments, and the presence of omega and deviant-shaped epiglottises), and their vocal folds were rated thicker in the vertical dimension, smaller in the lateral dimension, longer, and more tense, with smaller amplitudes of excursion during vibration. Glottal closure in male subjects was rated more complete, but briefer in duration. Significant effects of the factors pitch, sound intensity, and age on vocal fold appearance and glottal functioning were ascertained. Awareness of the influence of these factors, as well as the factor gender, on the rated scales is essential for an adequate evaluation of laryngostroboscopic images.

Studying emotion theories through connectivity analysis: Evidence from generalized psychophysiological interactions and graph theory.

PubMed

Huang, Yun-An; Jastorff, Jan; Van den Stock, Jan; Van de Vliet, Laura; Dupont, Patrick; Vandenbulcke, Mathieu

2018-05-15

Psychological construction models of emotion state that emotions are variable concepts constructed by fundamental psychological processes, whereas according to basic emotion theory, emotions cannot be divided into more fundamental units and each basic emotion is represented by a unique and innate neural circuitry. In a previous study, we found evidence for the psychological construction account by showing that several brain regions were commonly activated when perceiving different emotions (i.e. a general emotion network). Moreover, this set of brain regions included areas associated with core affect, conceptualization and executive control, as predicted by psychological construction models. Here we investigate directed functional brain connectivity in the same dataset to address two questions: 1) is there a common pathway within the general emotion network for the perception of different emotions and 2) if so, does this common pathway contain information to distinguish between different emotions? We used generalized psychophysiological interactions and information flow indices to examine the connectivity within the general emotion network. The results revealed a general emotion pathway that connects neural nodes involved in core affect, conceptualization, language and executive control. Perception of different emotions could not be accurately classified based on the connectivity patterns from the nodes of the general emotion pathway. Successful classification was achieved when connections outside the general emotion pathway were included. We propose that the general emotion pathway functions as a common pathway within the general emotion network and is involved in shared basic psychological processes across emotions. However, additional connections within the general emotion network are required to classify different emotions, consistent with a constructionist account. Copyright © 2018 Elsevier Inc. All rights reserved.

A general transformation to canonical form for potentials in pairwise interatomic interactions.

PubMed

Walton, Jay R; Rivera-Rivera, Luis A; Lucchese, Robert R; Bevan, John W

2015-06-14

A generalized formulation of explicit force-based transformations is introduced to investigate the concept of a canonical potential in both fundamental chemical and intermolecular bonding. Different classes of representative ground electronic state pairwise interatomic interactions are referenced to a chosen canonical potential illustrating application of such transformations. Specifically, accurately determined potentials of the diatomic molecules H2, H2(+), HF, LiH, argon dimer, and one-dimensional dissociative coordinates in Ar-HBr, OC-HF, and OC-Cl2 are investigated throughout their bound potentials. Advantages of the current formulation for accurately evaluating equilibrium dissociation energies and a fundamentally different unified perspective on nature of intermolecular interactions will be emphasized. In particular, this canonical approach has significance to previous assertions that there is no very fundamental distinction between van der Waals bonding and covalent bonding or for that matter hydrogen and halogen bonds.

Grain Boundary Plane Orientation Fundamental Zones and Structure-Property Relationships

PubMed Central

Homer, Eric R.; Patala, Srikanth; Priedeman, Jonathan L.

2015-01-01

Grain boundary plane orientation is a profoundly important determinant of character in polycrystalline materials that is not well understood. This work demonstrates how boundary plane orientation fundamental zones, which capture the natural crystallographic symmetries of a grain boundary, can be used to establish structure-property relationships. Using the fundamental zone representation, trends in computed energy, excess volume at the grain boundary, and temperature-dependent mobility naturally emerge and show a strong dependence on the boundary plane orientation. Analysis of common misorientation axes even suggests broader trends of grain boundary energy as a function of misorientation angle and plane orientation. Due to the strong structure-property relationships that naturally emerge from this work, boundary plane fundamental zones are expected to simplify analysis of both computational and experimental data. This standardized representation has the potential to significantly accelerate research in the topologically complex and vast five-dimensional phase space of grain boundaries. PMID:26498715

Grain boundary plane orientation fundamental zones and structure-property relationships

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

Homer, Eric R.; Patala, Srikanth; Priedeman, Jonathan L.

2015-10-26

Grain boundary plane orientation is a profoundly important determinant of character in polycrystalline materials that is not well understood. This work demonstrates how boundary plane orientation fundamental zones, which capture the natural crystallographic symmetries of a grain boundary, can be used to establish structure-property relationships. Using the fundamental zone representation, trends in computed energy, excess volume at the grain boundary, and temperature-dependent mobility naturally emerge and show a strong dependence on the boundary plane orientation. Analysis of common misorientation axes even suggests broader trends of grain boundary energy as a function of misorientation angle and plane orientation. Due to themore » strong structure-property relationships that naturally emerge from this work, boundary plane fundamental zones are expected to simplify analysis of both computational and experimental data. This standardized representation has the potential to significantly accelerate research in the topologically complex and vast five-dimensional phase space of grain boundaries.« less

Is Education a Fundamental Right? People's Lay Theories About Intellectual Potential Drive Their Positions on Education.

PubMed

Savani, Krishna; Rattan, Aneeta; Dweck, Carol S

2017-09-01

Does every child have a fundamental right to receive a high-quality education? We propose that people's beliefs about whether "nearly everyone" or "only some people" have high intellectual potential drive their positions on education. Three studies found that the more people believed that nearly everyone has high potential, the more they viewed education as a fundamental human right. Furthermore, people who viewed education as a fundamental right, in turn (a) were more likely to support the institution of free public education, (b) were more concerned upon learning that students in the country were not performing well academically compared with students in peer nations, and (c) were more likely to support redistributing educational funds more equitably across wealthier and poorer school districts. The studies show that people's beliefs about intellectual potential can influence their positions on education, which can affect the future quality of life for countless students.

Secondary instability in boundary-layer flows

NASA Technical Reports Server (NTRS)

Nayfeh, A. H.; Bozatli, A. N.

1979-01-01

The stability of a secondary Tollmien-Schlichting wave, whose wavenumber and frequency are nearly one half those of a fundamental Tollmien-Schlichting instability wave is analyzed using the method of multiple scales. Under these conditions, the fundamental wave acts as a parametric exciter for the secondary wave. The results show that the amplitude of the fundamental wave must exceed a critical value to trigger this parametric instability. This value is proportional to a detuning parameter which is the real part of k - 2K, where k and K are the wavenumbers of the fundamental and its subharmonic, respectively. For Blasius flow, the critical amplitude is approximately 29% of the mean flow, and hence many other secondary instabilities take place before this parametric instability becomes significant. For other flows where the detuning parameter is small, such as free-shear layer flows, the critical amplitude can be small, thus the parametric instability might play a greater role.

Properties of experimental titanium cast investment mixing with water reducing agent solution.

PubMed

Zhang, Zutai; Ding, Ning; Tamaki, Yukimichi; Hotta, Yasuhiro; Han-Cheol, Cho; Miyazaki, Takashi

2012-01-01

This study aimed to develop a dental investment for titanium casting. ZrO(2) and Al(2)O(3) were selected as refractory materials to prepare three investments (Codes: A-C) according to the quantity of Zr. Al(2)O(3) cement was used as a binder at a ratio of 15%, they were mixed with special mixing liquid. B1 was used as a control mixed with water. Fundamental examinations were statistically evaluated. A casting test was performed with investment B. Fluidities, setting times, and green strengths showed no remarkable differences; however, they were significantly different from those of B1. Expansion values for A, B, C, and B1 at 850°C were 1.03%±0.08%, 1.96%±0.17%, 4.35%±0.23%, and 1.50%±0.28%, respectively. Castings were covered by only small amounts of mold materials. The hardness test showed no significant differences between castings from B and the ones from commercial investments. The experimental special mixing liquid effectively reduced the water/powder ratio and improved the strength and thermal expansion.

Evolutionary dynamics of language systems

PubMed Central

Wu, Chieh-Hsi; Hua, Xia; Dunn, Michael; Levinson, Stephen C.; Gray, Russell D.

2017-01-01

Understanding how and why language subsystems differ in their evolutionary dynamics is a fundamental question for historical and comparative linguistics. One key dynamic is the rate of language change. While it is commonly thought that the rapid rate of change hampers the reconstruction of deep language relationships beyond 6,000–10,000 y, there are suggestions that grammatical structures might retain more signal over time than other subsystems, such as basic vocabulary. In this study, we use a Dirichlet process mixture model to infer the rates of change in lexical and grammatical data from 81 Austronesian languages. We show that, on average, most grammatical features actually change faster than items of basic vocabulary. The grammatical data show less schismogenesis, higher rates of homoplasy, and more bursts of contact-induced change than the basic vocabulary data. However, there is a core of grammatical and lexical features that are highly stable. These findings suggest that different subsystems of language have differing dynamics and that careful, nuanced models of language change will be needed to extract deeper signal from the noise of parallel evolution, areal readaptation, and contact. PMID:29073028

Superhydrophobic surfaces fabricated by femtosecond laser with tunable water adhesion: from lotus leaf to rose petal.

PubMed

Long, Jiangyou; Fan, Peixun; Gong, Dingwei; Jiang, Dafa; Zhang, Hongjun; Li, Lin; Zhong, Minlin

2015-05-13

Superhydrophobic surfaces with tunable water adhesion have attracted much interest in fundamental research and practical applications. In this paper, we used a simple method to fabricate superhydrophobic surfaces with tunable water adhesion. Periodic microstructures with different topographies were fabricated on copper surface via femtosecond (fs) laser irradiation. The topography of these microstructures can be controlled by simply changing the scanning speed of the laser beam. After surface chemical modification, these as-prepared surfaces showed superhydrophobicity combined with different adhesion to water. Surfaces with deep microstructures showed self-cleaning properties with extremely low water adhesion, and the water adhesion increased when the surface microstructures became flat. The changes in surface water adhesion are attributed to the transition from Cassie state to Wenzel state. We also demonstrated that these superhydrophobic surfaces with different adhesion can be used for transferring small water droplets without any loss. We demonstrate that our approach provides a novel but simple way to tune the surface adhesion of superhydrophobic metallic surfaces for good potential applications in related areas.

The Effect of Microphone Type on Acoustical Measures of Synthesized Vowels.

PubMed

Kisenwether, Jessica Sofranko; Sataloff, Robert T

2015-09-01

The purpose of this study was to compare microphones of different directionality, transducer type, and cost, with attention to their effects on acoustical measurements of period perturbation, amplitude perturbation, and noise using synthesized sustained vowel samples. This was a repeated measures design. Synthesized sustained vowel stimuli (with known acoustic characteristics and systematic changes in jitter, shimmer, and noise-to-harmonics ratio) were recorded by a variety of dynamic and condenser microphones. Files were then analyzed for mean fundamental frequency (fo), fo standard deviation, absolute jitter, shimmer in dB, peak-to-peak amplitude variation, and noise-to-harmonics ratio. Acoustical measures following recording were compared with the synthesized, known acoustical measures before recording. Although informal analyses showed some differences among microphones, and analyses of variance showed that type of microphone is a significant predictor, t-tests revealed that none of the microphones generated different means compared with the generated acoustical measures. In this sample, microphone type, directionality, and cost did not have a significant effect on the validity of acoustic measures. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Qualitatively different coding of symbolic and nonsymbolic numbers in the human brain.

PubMed

Lyons, Ian M; Ansari, Daniel; Beilock, Sian L

2015-02-01

Are symbolic and nonsymbolic numbers coded differently in the brain? Neuronal data indicate that overlap in numerical tuning curves is a hallmark of the approximate, analogue nature of nonsymbolic number representation. Consequently, patterns of fMRI activity should be more correlated when the representational overlap between two numbers is relatively high. In bilateral intraparietal sulci (IPS), for nonsymbolic numbers, the pattern of voxelwise correlations between pairs of numbers mirrored the amount of overlap in their tuning curves under the assumption of approximate, analogue coding. In contrast, symbolic numbers showed a flat field of modest correlations more consistent with discrete, categorical representation (no systematic overlap between numbers). Directly correlating activity patterns for a given number across formats (e.g., the numeral "6" with six dots) showed no evidence of shared symbolic and nonsymbolic number-specific representations. Overall (univariate) activity in bilateral IPS was well fit by the log of the number being processed for both nonsymbolic and symbolic numbers. IPS activity is thus sensitive to numerosity regardless of format; however, the nature in which symbolic and nonsymbolic numbers are encoded is fundamentally different. © 2014 Wiley Periodicals, Inc.

Physical Education Teacher Training in Fundamental Movement Skills Makes a Difference to Instruction and Assessment Practices

ERIC Educational Resources Information Center

Lander, Natalie Jayne; Barnett, Lisa M.; Brown, Helen; Telford, Amanda

2015-01-01

The purpose of this study was to investigate instruction and assessment of fundamental movement skills (FMSs) by Physical Education (PE) teachers of Year 7 girls. Of 168 secondary school PE teachers, many had received little FMSs professional development, and although most assessed student FMSs proficiency, the quality of assessment was variable.…

Photocatalysis of Modified Transition Metal Oxide Surfaces

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

Batzill, Matthias

The goal of this project has been to establish a cause-effect relationship for photocatalytic activity variations of different structures of the same material; and furthermore gain fundamental understanding on modification of photocatalysts by compositional or surface modifications. The reasoning is that gaining atomic scale understanding of how surface and bulk modifications alter the photo reactivity will lead to design principles for next generation photocatalysts. As a prototypical photocatalyst the research focused on TiO 2 synthesized in well-defined single crystalline form to enable fundamental characterizations.We have obtained results in the following areas: (a) Preparation of epitaxial anatase TiO 2 samples bymore » pulsed laser deposition. (b) Comparison of hydrogen diffusion on different crystallographic surface. (c) Determining the stability of the TiO 2(011)-2x1 reconstruction upon interactions with adsorbates. (d) Characterization of adsorption and (thermal and photo) reaction of molecules with nitro-endgroups, (e) Exploring the possibility of modifying planar model photocatalyst surfaces with graphene to enable fundamental studies on reported enhanced photocatalytic activities of graphene modified transition metal oxides, (f) gained fundamental understanding on the role of crystallographic polymorphs of the same material for their photocatalytic activities.« less

Convexities move because they contain matter.

PubMed

Barenholtz, Elan

2010-09-22

Figure-ground assignment to a contour is a fundamental stage in visual processing. The current paper introduces a novel, highly general dynamic cue to figure-ground assignment: "Convex Motion." Across six experiments, subjects showed a strong preference to assign figure and ground to a dynamically deforming contour such that the moving contour segment was convex rather than concave. Experiments 1 and 2 established the preference across two different kinds of deformational motion. Additional experiments determined that this preference was not due to fixation (Experiment 3) or attentional mechanisms (Experiment 4). Experiment 5 found a similar, but reduced bias for rigid-as opposed to deformational-motion, and Experiment 6 demonstrated that the phenomenon depends on the global motion of the effected contour. An explanation of this phenomenon is presented on the basis of typical natural deformational motion, which tends to involve convex contour projections that contain regions consisting of physical "matter," as opposed to concave contour indentations that contain empty space. These results highlight the fundamental relationship between figure and ground, perceived shape, and the inferred physical properties of an object.

An experimental test of a fundamental food web motif.

PubMed

Rip, Jason M K; McCann, Kevin S; Lynn, Denis H; Fawcett, Sonia

2010-06-07

Large-scale changes to the world's ecosystem are resulting in the deterioration of biostructure-the complex web of species interactions that make up ecological communities. A difficult, yet crucial task is to identify food web structures, or food web motifs, that are the building blocks of this baroque network of interactions. Once identified, these food web motifs can then be examined through experiments and theory to provide mechanistic explanations for how structure governs ecosystem stability. Here, we synthesize recent ecological research to show that generalist consumers coupling resources with different interaction strengths, is one such motif. This motif amazingly occurs across an enormous range of spatial scales, and so acts to distribute coupled weak and strong interactions throughout food webs. We then perform an experiment that illustrates the importance of this motif to ecological stability. We find that weak interactions coupled to strong interactions by generalist consumers dampen strong interaction strengths and increase community stability. This study takes a critical step by isolating a common food web motif and through clear, experimental manipulation, identifies the fundamental stabilizing consequences of this structure for ecological communities.

Shifts in growth strategies reflect tradeoffs in cellular economics

PubMed Central

Molenaar, Douwe; van Berlo, Rogier; de Ridder, Dick; Teusink, Bas

2009-01-01

The growth rate-dependent regulation of cell size, ribosomal content, and metabolic efficiency follows a common pattern in unicellular organisms: with increasing growth rates, cell size and ribosomal content increase and a shift to energetically inefficient metabolism takes place. The latter two phenomena are also observed in fast growing tumour cells and cell lines. These patterns suggest a fundamental principle of design. In biology such designs can often be understood as the result of the optimization of fitness. Here we show that in basic models of self-replicating systems these patterns are the consequence of maximizing the growth rate. Whereas most models of cellular growth consider a part of physiology, for instance only metabolism, the approach presented here integrates several subsystems to a complete self-replicating system. Such models can yield fundamentally different optimal strategies. In particular, it is shown how the shift in metabolic efficiency originates from a tradeoff between investments in enzyme synthesis and metabolic yields for alternative catabolic pathways. The models elucidate how the optimization of growth by natural selection shapes growth strategies. PMID:19888218

An alternative approach based on artificial neural networks to study controlled drug release.

PubMed

Reis, Marcus A A; Sinisterra, Rubén D; Belchior, Jadson C

2004-02-01

An alternative methodology based on artificial neural networks is proposed to be a complementary tool to other conventional methods to study controlled drug release. Two systems are used to test the approach; namely, hydrocortisone in a biodegradable matrix and rhodium (II) butyrate complexes in a bioceramic matrix. Two well-established mathematical models are used to simulate different release profiles as a function of fundamental properties; namely, diffusion coefficient (D), saturation solubility (C(s)), drug loading (A), and the height of the device (h). The models were tested, and the results show that these fundamental properties can be predicted after learning the experimental or model data for controlled drug release systems. The neural network results obtained after the learning stage can be considered to quantitatively predict ideal experimental conditions. Overall, the proposed methodology was shown to be efficient for ideal experiments, with a relative average error of <1% in both tests. This approach can be useful for the experimental analysis to simulate and design efficient controlled drug-release systems. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association

Transmission of chirality through space and across length scales

NASA Astrophysics Data System (ADS)

Morrow, Sarah M.; Bissette, Andrew J.; Fletcher, Stephen P.

2017-05-01

Chirality is a fundamental property and vital to chemistry, biology, physics and materials science. The ability to use asymmetry to operate molecular-level machines or macroscopically functional devices, or to give novel properties to materials, may address key challenges at the heart of the physical sciences. However, how chirality at one length scale can be translated to asymmetry at a different scale is largely not well understood. In this Review, we discuss systems where chiral information is translated across length scales and through space. A variety of synthetic systems involve the transmission of chiral information between the molecular-, meso- and macroscales. We show how fundamental stereochemical principles may be used to design and understand nanoscale chiral phenomena and highlight important recent advances relevant to nanotechnology. The survey reveals that while the study of stereochemistry on the nanoscale is a rich and dynamic area, our understanding of how to control and harness it and dial-up specific properties is still in its infancy. The long-term goal of controlling nanoscale chirality promises to be an exciting journey, revealing insight into biological mechanisms and providing new technologies based on dynamic physical properties.

Variability in the relationships among voice quality, harmonic amplitudes, open quotient, and glottal area waveform shape in sustained phonationa

PubMed Central

Kreiman, Jody; Shue, Yen-Liang; Chen, Gang; Iseli, Markus; Gerratt, Bruce R.; Neubauer, Juergen; Alwan, Abeer

2012-01-01

Increases in open quotient are widely assumed to cause changes in the amplitude of the first harmonic relative to the second (H1*–H2*), which in turn correspond to increases in perceived vocal breathiness. Empirical support for these assumptions is rather limited, and reported relationships among these three descriptive levels have been variable. This study examined the empirical relationship among H1*–H2*, the glottal open quotient (OQ), and glottal area waveform skewness, measured synchronously from audio recordings and high-speed video images of the larynges of six phonetically knowledgeable, vocally healthy speakers who varied fundamental frequency and voice qualities quasi-orthogonally. Across speakers and voice qualities, OQ, the asymmetry coefficient, and fundamental frequency accounted for an average of 74% of the variance in H1*–H2*. However, analyses of individual speakers showed large differences in the strategies used to produce the same intended voice qualities. Thus, H1*–H2* can be predicted with good overall accuracy, but its relationship to phonatory characteristics appears to be speaker dependent. PMID:23039455

Fundamental study on reactivities of gluten protein types from wheat, rye and barley with five sandwich ELISA test kits.

PubMed

Lexhaller, Barbara; Tompos, Christine; Scherf, Katharina Anne

2017-12-15

Monitoring the compliance of gluten-free foods to the regulatory threshold of 20mg/kg of gluten is essential for celiac disease patients. The different enzyme-linked immunosorbent assays (ELISAs) for gluten detection each have specific characteristics, but there are only a few systematic comparisons. This fundamental study compared the specificities and sensitivities of the R5, G12 and Skerritt monoclonal and two polyclonal antibodies to well-defined gluten protein types (GPT) isolated from wheat, rye and barley flours. Quantitation of protein concentrations by reversed-phase high-performance liquid chromatography provided independent reference values. The ELISA responses showed high variability depending on the type of cereal, the GPT and the antibody used. Overall, ω1,2-gliadins and γ-75k-secalins were most reactive, whereas ω5-gliadins and γ-, B- and D-hordeins were detected with the lowest sensitivities. These results revealed which GPT each antibody is most sensitive to and provided novel insights that will be helpful for appropriate calibration of ELISAs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Constraining possible variations of the fine structure constant in strong gravitational fields with the Kα iron line

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

Bambi, Cosimo, E-mail: bambi@fudan.edu.cn

2014-03-01

In extensions of general relativity and in theories aiming at unifying gravity with the forces of the Standard Model, the value of the ''fundamental constants'' is often determined by the vacuum expectation value of new fields, which may thus change in different backgrounds. Variations of fundamental constants with respect to the values measured today in laboratories on Earth are expected to be more evident on cosmological timescales and/or in strong gravitational fields. In this paper, I show that the analysis of the Kα iron line observed in the X-ray spectrum of black holes can potentially be used to probe themore » fine structure constant α in gravitational potentials relative to Earth of Δφ ≈ 0.1. At present, systematic effects not fully under control prevent to get robust and stringent bounds on possible variations of the value of α with this technique, but the fact that current data can be fitted with models based on standard physics already rules out variations of the fine structure constant larger than some percent.« less

A comparative study of the vibrational spectra of the anticancer drug melphalan and its fundamental molecules 3-phenylpropionic acid and L-phenylalanine

NASA Astrophysics Data System (ADS)

Badawi, Hassan M.; Khan, Ibrahim

2016-04-01

The structural stability and the vibrational spectra of the anticancer drug melphalan and its parent compounds 3-phenylpropionic acid and L-phenylalanine were investigated by the DFT B3LYP/6-311G** calculations. Melphalan and its fundamental compounds were predicted to exist predominantly in non-planar structures. The vibrational frequencies of the low energy structures of melphalan, 3-phenylpropionic acid, and phenylalanine were computed at the DFT B3LYP level of theory. Complete vibrational assignments of the normal modes of melphalan, 3-phenylpropionic acid, and phenylalanine were provided by combined theoretical and experimental data of the molecules. The experimental infrared spectra of phenylalanine and melphalan show a significantly different pattern of the Cdbnd O stretching mode as compared to those of normal carboxylic acids. A comparison of the 3700-2000 cm-1 infrared spectral region of the three molecules suggests the presence of similar intermolecular H-bonding in their condensed phases. The observed infrared and Raman spectra are consistent with the presence of one predominant melphalan conformation at room temperature.

STELLAR ATMOSPHERES, ATMOSPHERIC EXTENSION, AND FUNDAMENTAL PARAMETERS: WEIGHING STARS USING THE STELLAR MASS INDEX

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

Neilson, Hilding R.; Lester, John B.; Baron, Fabien

2016-10-20

One of the great challenges of understanding stars is measuring their masses. The best methods for measuring stellar masses include binary interaction, asteroseismology, and stellar evolution models, but these methods are not ideal for red giant and supergiant stars. In this work, we propose a novel method for inferring stellar masses of evolved red giant and supergiant stars using interferometric and spectrophotometric observations combined with spherical model stellar atmospheres to measure what we call the stellar mass index, defined as the ratio between the stellar radius and mass. The method is based on the correlation between different measurements of angularmore » diameter, used as a proxy for atmospheric extension, and fundamental stellar parameters. For a given star, spectrophotometry measures the Rosseland angular diameter while interferometric observations generally probe a larger limb-darkened angular diameter. The ratio of these two angular diameters is proportional to the relative extension of the stellar atmosphere, which is strongly correlated to the star’s effective temperature, radius, and mass. We show that these correlations are strong and can lead to precise measurements of stellar masses.« less

Structural building principles of complex face-centered cubic intermetallics.

PubMed

Dshemuchadse, Julia; Jung, Daniel Y; Steurer, Walter

2011-08-01

Fundamental structural building principles are discussed for all 56 known intermetallic phases with approximately 400 or more atoms per unit cell and space-group symmetry F43m, Fd3m, Fd3, Fm3m or Fm3c. Despite fundamental differences in chemical composition, bonding and electronic band structure, their complex crystal structures show striking similarities indicating common building principles. We demonstrate that the structure-determining elements are flat and puckered atomic {110} layers stacked with periodicities 2p. The atoms on this set of layers, which intersect each other, form pentagon face-sharing endohedral fullerene-like clusters arranged in a face-centered cubic packing (f.c.c.). Due to their topological layer structure, all these crystal structures can be described as (p × p × p) = p(3)-fold superstructures of a common basic structure of the double-diamond type. The parameter p, with p = 3, 4, 7 or 11, is determined by the number of layers per repeat unit and the type of cluster packing, which in turn are controlled by chemical composition.

Theory and practice: How do we teach our students about light?

NASA Astrophysics Data System (ADS)

Creath, Katherine

2007-08-01

As optical scientists and engineers we have an educational paradigm that stresses passing knowledge from teacher to student. We are also taught to use inductive reasoning to solve problems. Yet many of the fundamental questions in optics such as the topic of this conference "What are photons?" require that we use retroductive reasoning to deduce the possible and probable cause of the observations and measurements we make. We can agree that we don't have all the answers for many fundamental questions in optics. The retroductive reasoning process requires a different way of thinking from our traditional classroom setting. Most of us learned to do this through working in a research lab or industry. With the amount of information and new discoveries to consider, it makes it difficult to cover everything in the classroom. This paper looks at transformational learning techniques and how they have been applied in science and engineering. These techniques show promise to prepare our students to learn how to learn and develop skills they can directly apply to research and industry.

Inversion of high frequency surface waves with fundamental and higher modes

USGS Publications Warehouse

Xia, J.; Miller, R.D.; Park, C.B.; Tian, G.

2003-01-01

The phase velocity of Rayleigh-waves of a layered earth model is a function of frequency and four groups of earth parameters: compressional (P)-wave velocity, shear (S)-wave velocity, density, and thickness of layers. For the fundamental mode of Rayleigh waves, analysis of the Jacobian matrix for high frequencies (2-40 Hz) provides a measure of dispersion curve sensitivity to earth model parameters. S-wave velocities are the dominant influence of the four earth model parameters. This thesis is true for higher modes of high frequency Rayleigh waves as well. Our numerical modeling by analysis of the Jacobian matrix supports at least two quite exciting higher mode properties. First, for fundamental and higher mode Rayleigh wave data with the same wavelength, higher modes can "see" deeper than the fundamental mode. Second, higher mode data can increase the resolution of the inverted S-wave velocities. Real world examples show that the inversion process can be stabilized and resolution of the S-wave velocity model can be improved when simultaneously inverting the fundamental and higher mode data. ?? 2002 Elsevier Science B.V. All rights reserved.

Characteristics of waste automotive glasses as silica resource in ferrosilicon synthesis.

PubMed

Farzana, Rifat; Rajarao, Ravindra; Sahajwalla, Veena

2016-02-01

This fundamental research on end-of-life automotive glasses, which are difficult to recycle, is aimed at understanding the chemical and physical characteristics of waste glasses as a resource of silica to produce ferrosilicon. Laboratory experiments at 1550°C were carried out using different automotive glasses and the results compared with those obtained with pure silica. In situ images of slag-metal separation showed similar behaviour for waste glasses and silica-bearing pellets. Though X-ray diffraction (XRD) showed different slag compositions for glass and silica-bearing pellets, formation of ferrosilicon was confirmed. Synthesized ferrosilicon alloy from waste glasses and silica were compared by Raman, X-ray photoelectron spectroscopy and scanning electron microscopy (SEM) analysis. Silicon concentration in the synthesized alloys showed almost 92% silicon recovery from the silica-bearing pellet and 74-92% silicon recoveries from various waste glass pellets. The polyvinyl butyral (PVB) plastic layer in the windshield glass decomposed at low temperature and did not show any detrimental effect on ferrosilicon synthesis. This innovative approach of using waste automotive glasses as a silica source for ferrosilicon production has the potential to create sustainable pathways, which will reduce specialty glass waste in landfill. © The Author(s) 2015.

Inclusive intervention to enhance the fundamental movement skills of children without hearing: a preliminary study.

PubMed

Gursel, Ferda

2014-02-01

The purpose of this study was to assess an intervention program on the fundamental movement skill of students with and without hearing impairment, using the Test of Gross Motor Development-2 (TGMD-2) standardized Turkish norm. Preschool children with and without hearing impairment participated in this study. At the beginning of the study, most of the children with hearing impairment demonstrated developmental delay on the Locomotor subscale (6/7), as did about one-third (4/11) of the children without hearing impairment. For the Object control subscale, 4/7 of children with hearing impairment and none without hearing impairment showed developmental delay prior to the intervention program. After the intervention program, 3/7 children with hearing impairment had developmental delay on the Locomotor subscale. On the Object control subscale, 2/7 children with hearing impairment and none without hearing impairment showed developmental delay. The six-week intervention program improved TGMD-2 scores of children with hearing impairment, yet did not yield statistically significant improvement of fundamental movement skills.

Dramatic genotypic difference in, and effect of genetic crossing on, tissue culture-induced mobility of retrotransposon Tos17 in rice.

PubMed

Lin, Chunjing; Lin, Xiuyun; Hu, Lanjuan; Yang, Jingjing; Zhou, Tianqi; Long, Likun; Xu, Chunming; Xing, Shaochen; Qi, Bao; Dong, Yingshan; Liu, Bao

2012-11-01

KEY MESSAGE : We show for the first time that intraspecific crossing may impact mobility of the prominent endogenous retrotransposon Tos17 under tissue culture conditions in rice. Tos17, an endogenous copia retrotransposon of rice, is transpositionally active in tissue culture. To study whether there exists fundamental genotypic difference in the tissue culture-induced mobility of Tos17, and if so, whether the difference is under genetic and/or epigenetic control, we conducted this investigation. We show that dramatic difference in tissue culture-induced Tos17 mobility exists among different rice pure-line cultivars sharing the same maternal parent: of the three lines studied that harbor Tos17, two showed mobilization of Tos17, which accrued in proportion to subculture duration, while the third line showed total quiescence (immobility) of the element and the fourth line did not contain the element. In reciprocal F1 hybrids between Tos17-mobile and -immobile (or absence) parental lines, immobility was dominant over mobility. In reciprocal F1 hybrids between both Tos17-mobile parental lines, an additive or synergistic effect on mobility of the element was noticed. In both types of reciprocal F1 hybrids, clear difference in the extent of Tos17 mobility was noted between crossing directions. Given that all lines share the same maternal parent, this observation indicates the existence of epigenetic parent-of-origin effect. We conclude that the tissue culture-induced mobility of Tos17 in rice is under complex genetic and epigenetic control, which can be either enhanced or repressed by intraspecific genetic crossing.

Numerical analysis of fundamental mode selection of a He-Ne laser by a circular aperture

NASA Astrophysics Data System (ADS)

He, Xin; Zhang, Bin

2011-11-01

In the He-Ne laser with an integrated cavity made of zerodur, the inner face performance of the gain tube is limited by the machining techniques, which tends to influence the beam propagation and transverse mode distribution. In order to improve the beam quality and select out the fundamental mode, an aperture is usually introduced in the cavity. In the process of laser design, the Fresnel-Kirchhoff diffraction integral equation is adopted to calculate the optical field distributions on each interface. The transit matrix is obtained based on self-reproducing principle and finite element method. Thus, optical field distribution on any interface and field loss of each transverse mode could be acquired by solving the eigenvalue and eigenvector of the transit matrix. For different-sized apertures in different positions, we could get different matrices and corresponding calculation results. By comparing these results, the optimal size and position of the aperture could be obtained. As a result, the feasibility of selecting fundamental mode in a zerodur He-Ne laser by a circular aperture has been verified theoretically.

Communication: "Position" does matter: The photofragmentation of the nitroimidazole isomers

NASA Astrophysics Data System (ADS)

Bolognesi, P.; Casavola, A. R.; Cartoni, A.; Richter, R.; Markus, P.; Borocci, S.; Chiarinelli, J.; Tošić, S.; Sa'adeh, H.; Masič, M.; Marinković, B. P.; Prince, K. C.; Avaldi, L.

2016-11-01

A combined experimental and theoretical approach has been used to disentangle the fundamental mechanisms of the fragmentation of the three isomers of nitroimidazole induced by vacuum ultra-violet (VUV) radiation, namely, 4-, 5-, and 2-nitroimidazole. The results of mass spectrometry as well as photoelectron-photoion coincidence spectroscopy display striking differences in the radiation-induced decomposition of the different nitroimidazole radical cations. Based on density functional theory (DFT) calculations, a model is proposed which fully explains such differences, and reveals the subtle fragmentation mechanisms leading to the release of neutral species like NO, CO, and HCN. Such species have a profound impact in biological media and may play a fundamental role in radiosensitising mechanisms during radiotherapy.

Empirical Examination of Fundamental Indexation in the German Market

NASA Astrophysics Data System (ADS)

Mihm, Max; Locarek-Junge, Hermann

Index Funds, Exchange Traded Funds and Derivatives give investors easy access to well diversified index portfolios. These index-based investment products exhibit low fees, which make them an attractive alternative to actively managed funds. Against this background, a new class of stock indices has been established based on the concept of “Fundamental Indexation”. The selection and weighting of index constituents is conducted by means of fundamental criteria like total assets, book value or number of employees. This paper examines the performance of fundamental indices in the German equity market. For this purpose, a backtest of five fundamental indices is conducted over the last 20 years. Furthermore the index returns are analysed under the assumption of an efficient as well as an inefficient market. Index returns in efficient markets are explained by applying the three factor model for stock returns of Fama and French (J Financ Econ 33(1):3-56, 1993). The results show that the outperformance of fundamental indices is partly due to a higher risk exposure, particularly to companies with a low price to book ratio. By relaxing the assumption of market efficiency, a return drag of capitalisation weighted indices can be deduced. Given a mean-reverting movement of prices, a direct connection between market capitalisation and index weighting leads to inferior returns.

Beyond network structure: How heterogeneous susceptibility modulates the spread of epidemics.

PubMed

Smilkov, Daniel; Hidalgo, Cesar A; Kocarev, Ljupco

2014-04-25

The compartmental models used to study epidemic spreading often assume the same susceptibility for all individuals, and are therefore, agnostic about the effects that differences in susceptibility can have on epidemic spreading. Here we show that-for the SIS model-differential susceptibility can make networks more vulnerable to the spread of diseases when the correlation between a node's degree and susceptibility are positive, and less vulnerable when this correlation is negative. Moreover, we show that networks become more likely to contain a pocket of infection when individuals are more likely to connect with others that have similar susceptibility (the network is segregated). These results show that the failure to include differential susceptibility to epidemic models can lead to a systematic over/under estimation of fundamental epidemic parameters when the structure of the networks is not independent from the susceptibility of the nodes or when there are correlations between the susceptibility of connected individuals.

Atypical prosody in Asperger syndrome: perceptual and acoustic measurements.

PubMed

Filipe, Marisa G; Frota, Sónia; Castro, São Luís; Vicente, Selene G

2014-08-01

It is known that individuals with Asperger syndrome (AS) may show no problems with regard to what is said (e.g., lexical content) but tend to have difficulties in how utterances are produced, i.e., they may show prosodic impairments. In the present study, we focus on the use of prosodic features to express grammatical meaning. Specifically, we explored the sentence type difference between statements and questions that is conveyed by intonation, using perceptual and acoustic measurements. Children aged 8 and 9 years with AS (n = 12) were matched according to age and nonverbal intelligence with typically developing peers (n = 17). Although children with AS could produce categorically accurate prosodic patterns, their prosodic contours were perceived as odd by adult listeners, and acoustic measurements showed alterations in duration and pitch. Additionally, children with AS had greater variability in fundamental frequency contours compared to typically developing peers.

ROC curve analyses of eyewitness identification decisions: An analysis of the recent debate.

PubMed

Rotello, Caren M; Chen, Tina

2016-01-01

How should the accuracy of eyewitness identification decisions be measured, so that best practices for identification can be determined? This fundamental question is under intense debate. One side advocates for continued use of a traditional measure of identification accuracy, known as the diagnosticity ratio , whereas the other side argues that receiver operating characteristic curves (ROCs) should be used instead because diagnosticity is confounded with response bias. Diagnosticity proponents have offered several criticisms of ROCs, which we show are either false or irrelevant to the assessment of eyewitness accuracy. We also show that, like diagnosticity, Bayesian measures of identification accuracy confound response bias with witnesses' ability to discriminate guilty from innocent suspects. ROCs are an essential tool for distinguishing memory-based processes from decisional aspects of a response; simulations of different possible identification tasks and response strategies show that they offer important constraints on theory development.

Beyond network structure: How heterogeneous susceptibility modulates the spread of epidemics

PubMed Central

Smilkov, Daniel; Hidalgo, Cesar A.; Kocarev, Ljupco

2014-01-01

The compartmental models used to study epidemic spreading often assume the same susceptibility for all individuals, and are therefore, agnostic about the effects that differences in susceptibility can have on epidemic spreading. Here we show that–for the SIS model–differential susceptibility can make networks more vulnerable to the spread of diseases when the correlation between a node's degree and susceptibility are positive, and less vulnerable when this correlation is negative. Moreover, we show that networks become more likely to contain a pocket of infection when individuals are more likely to connect with others that have similar susceptibility (the network is segregated). These results show that the failure to include differential susceptibility to epidemic models can lead to a systematic over/under estimation of fundamental epidemic parameters when the structure of the networks is not independent from the susceptibility of the nodes or when there are correlations between the susceptibility of connected individuals. PMID:24762621

Evidence from intrinsic activity that asymmetry of the human brain is controlled by multiple factors.

PubMed

Liu, Hesheng; Stufflebeam, Steven M; Sepulcre, Jorge; Hedden, Trey; Buckner, Randy L

2009-12-01

Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each accounted for significant variation across subjects. The factors were associated with brain systems involved in vision, internal thought (the default network), attention, and language. An independent sample of right- and left-handed individuals showed that hand dominance affects brain asymmetry but differentially across the 4 factors supporting their independence. These findings show the feasibility of measuring brain asymmetry using intrinsic activity fluctuations and suggest that multiple genetic or environmental mechanisms control cerebral lateralization.

Fundamental differences in axial and appendicular bone density in stress fractured and uninjured Royal Marine recruits--a matched case-control study.

PubMed

Davey, Trish; Lanham-New, Susan A; Shaw, Anneliese M; Cobley, Rosalyn; Allsopp, Adrian J; Hajjawi, Mark O R; Arnett, Timothy R; Taylor, Pat; Cooper, Cyrus; Fallowfield, Joanne L

2015-04-01

Stress fracture is a common overuse injury within military training, resulting in significant economic losses to the military worldwide. Studies to date have failed to fully identify the bone density and bone structural differences between stress fractured personnel and controls due to inadequate adjustment for key confounding factors; namely age, body size and physical fitness; and poor sample size. The aim of this study was to investigate bone differences between male Royal Marine recruits who suffered a stress fracture during the 32 weeks of training and uninjured control recruits, matched for age, body weight, height and aerobic fitness. A total of 1090 recruits were followed through training and 78 recruits suffered at least one stress fracture. Bone mineral density (BMD) was measured at the lumbar spine (LS), femoral neck (FN) and whole body (WB) using Dual X-ray Absorptiometry in 62 matched pairs; tibial bone parameters were measured using peripheral Quantitative Computer Tomography in 51 matched pairs. Serum C-terminal peptide concentration was measured as a marker of bone resorption at baseline, week-15 and week-32. ANCOVA was used to determine differences between stress fractured recruits and controls. BMD at the LS, WB and FN sites was consistently lower in the stress fracture group (P<0.001). Structural differences between the stress fracture recruits and controls were evident in all slices of the tibia, with the most prominent differences seen at the 38% tibial slice. There was a negative correlation between the bone cross-sectional area and BMD at the 38% tibial slice. There was no difference in serum CTx concentration between stress fracture recruits and matched controls at any stage of training. These results show evidence of fundamental differences in bone mass and structure in stress fracture recruits, and provide useful data on bone risk factor profiles for stress fracture within a healthy military population. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Differences in chemical doping matter: Superconductivity in Ti 1-xTa xSe 2 but not in Ti 1-xNb xSe 2

DOE PAGES

Luo, Huixia; Zhu, Yimei; Xie, Weiwei; ...

2016-02-21

We report that 1T-TiSe 2, an archetypical layered transition metal dichalcogenide, becomes superconducting when Ta is substituted for Ti but not when Nb is substituted for Ti. This is unexpected because Nb and Ta should be chemically equivalent electron donors. Superconductivity emerges near x = 0.02 for Ti 1–xTa xSe 2, while, for Ti 1–xNb xSe 2, no superconducting transitions are observed above 0.4 K. The equivalent chemical nature of the dopants is confirmed by X-ray photoelectron spectroscopy. ARPES and Raman scattering studies show similarities and differences between the two systems, but the fundamental reasons why the Nb and Tamore » dopants yield such different behavior are unknown. We present a comparison of the electronic phase diagrams of many electron-doped 1T-TiSe 2 systems, showing that they behave quite differently, which may have broad implications in the search for new superconductors. Here, we propose that superconducting Ti 0.8Ta 0.2Se 2 will be suitable for devices and other studies based on exfoliated crystal flakes.« less

Nurse managers' preferred and perceived leadership styles: a study at an Italian hospital.

PubMed

Zampieron, Alessandra; Spanio, Daniele; Bernardi, Paola; Milan, Rosalia; Buja, Alessandra

2013-04-01

The aim of this cross-sectional descriptive study was to compare the different leadership styles based on perceptions of nurse managers and their staff. Nurse managers' styles are fundamental to improving subordinates' performance and achieving goals at health-care institutions. This was a cross-sectional study. A questionnaire developed by Ekvall & Arvonen, considering three leadership domains (Change, Production and Employee relations), was administered to all nurse managers and to their subordinates at a city hospital in north-east Italy. The comparison between the leadership styles actually adopted and those preferred by the nurse managers showed that the preferred style always scored higher than the style adopted, the difference reaching statistical significance for Change and Production. The leadership styles preferred by subordinates always scored higher than the styles their nurse managers actually adopted; in the subordinates' opinion, the differences being statistically significant in all three leadership domains. The study showed that nurse managers' expectations in relation to their leadership differ from those of their subordinates. These findings should be borne in mind when selecting and training nurse managers and other personnel, and they should influence the hospital's strategic management of nurses. © 2012 Blackwell Publishing Ltd.

The Emergence of Relationship-based Cooperation.

PubMed

Xu, Bo; Wang, Jianwei

2015-11-16

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality.

Delay induced high order locking effects in semiconductor lasers

NASA Astrophysics Data System (ADS)

Kelleher, B.; Wishon, M. J.; Locquet, A.; Goulding, D.; Tykalewicz, B.; Huyet, G.; Viktorov, E. A.

2017-11-01

Multiple time scales appear in many nonlinear dynamical systems. Semiconductor lasers, in particular, provide a fertile testing ground for multiple time scale dynamics. For solitary semiconductor lasers, the two fundamental time scales are the cavity repetition rate and the relaxation oscillation frequency which is a characteristic of the field-matter interaction in the cavity. Typically, these two time scales are of very different orders, and mutual resonances do not occur. Optical feedback endows the system with a third time scale: the external cavity repetition rate. This is typically much longer than the device cavity repetition rate and suggests the possibility of resonances with the relaxation oscillations. We show that for lasers with highly damped relaxation oscillations, such resonances can be obtained and lead to spontaneous mode-locking. Two different laser types-—a quantum dot based device and a quantum well based device—are analysed experimentally yielding qualitatively identical dynamics. A rate equation model is also employed showing an excellent agreement with the experimental results.

Delay induced high order locking effects in semiconductor lasers.

PubMed

Kelleher, B; Wishon, M J; Locquet, A; Goulding, D; Tykalewicz, B; Huyet, G; Viktorov, E A

2017-11-01

Multiple time scales appear in many nonlinear dynamical systems. Semiconductor lasers, in particular, provide a fertile testing ground for multiple time scale dynamics. For solitary semiconductor lasers, the two fundamental time scales are the cavity repetition rate and the relaxation oscillation frequency which is a characteristic of the field-matter interaction in the cavity. Typically, these two time scales are of very different orders, and mutual resonances do not occur. Optical feedback endows the system with a third time scale: the external cavity repetition rate. This is typically much longer than the device cavity repetition rate and suggests the possibility of resonances with the relaxation oscillations. We show that for lasers with highly damped relaxation oscillations, such resonances can be obtained and lead to spontaneous mode-locking. Two different laser types--a quantum dot based device and a quantum well based device-are analysed experimentally yielding qualitatively identical dynamics. A rate equation model is also employed showing an excellent agreement with the experimental results.

Mspire-Simulator: LC-MS shotgun proteomic simulator for creating realistic gold standard data.

PubMed

Noyce, Andrew B; Smith, Rob; Dalgleish, James; Taylor, Ryan M; Erb, K C; Okuda, Nozomu; Prince, John T

2013-12-06

The most important step in any quantitative proteomic pipeline is feature detection (aka peak picking). However, generating quality hand-annotated data sets to validate the algorithms, especially for lower abundance peaks, is nearly impossible. An alternative for creating gold standard data is to simulate it with features closely mimicking real data. We present Mspire-Simulator, a free, open-source shotgun proteomic simulator that goes beyond previous simulation attempts by generating LC-MS features with realistic m/z and intensity variance along with other noise components. It also includes machine-learned models for retention time and peak intensity prediction and a genetic algorithm to custom fit model parameters for experimental data sets. We show that these methods are applicable to data from three different mass spectrometers, including two fundamentally different types, and show visually and analytically that simulated peaks are nearly indistinguishable from actual data. Researchers can use simulated data to rigorously test quantitation software, and proteomic researchers may benefit from overlaying simulated data on actual data sets.

Nutritional composition, bioactive compounds and volatile profile of cocoa beans from different regions of Cameroon.

PubMed

Caprioli, Giovanni; Fiorini, Dennis; Maggi, Filippo; Nicoletti, Marcello; Ricciutelli, Massimo; Toniolo, Chiara; Prosper, Biapa; Vittori, Sauro; Sagratini, Gianni

2016-06-01

Analysis of the complex composition of cocoa beans provides fundamental information for evaluating the quality and nutritional aspects of cocoa-based food products, nutraceuticals and supplements. Cameroon, the world's fourth largest producer of cocoa, has been defined as "Africa in miniature" because of the variety it habitats. In order to evaluate the nutritional characteristics of cocoa beans from five different regions of Cameroon, we studied their polyphenolic content, volatile compounds and fatty acids composition. The High Performance Thin Layer Chromatography (HPTLC) analysis showed that the Mbalmayo sample had the highest content of theobromine (11.6 mg/g) and caffeic acid (2.1 mg/g), while the Sanchou sample had the highest level of (-)-epicatechin (142.9 mg/g). Concerning fatty acids, the lowest level of stearic acid was found in the Mbalmayo sample while the Bertoua sample showed the highest content of oleic acid. Thus, we confirmed that geographical origin influences the quality and nutritional characteristics of cocoa from these regions of Cameroon.

Texture coarseness responsive neurons and their mapping in layer 2–3 of the rat barrel cortex in vivo

PubMed Central

Garion, Liora; Dubin, Uri; Rubin, Yoav; Khateb, Mohamed; Schiller, Yitzhak; Azouz, Rony; Schiller, Jackie

2014-01-01

Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2–3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered. Multi-contact single unit recordings showed a vertical columnar organization of texture coarseness preference in layer 2–3. These findings indicate that layer 2–3 neurons perform high hierarchical processing of tactile information, with surface coarseness embodied by distinct neuronal subpopulations that are spatially mapped onto the barrel cortex. DOI: http://dx.doi.org/10.7554/eLife.03405.001 PMID:25233151

Encoding sensory and motor patterns as time-invariant trajectories in recurrent neural networks

PubMed Central

2018-01-01

Much of the information the brain processes and stores is temporal in nature—a spoken word or a handwritten signature, for example, is defined by how it unfolds in time. However, it remains unclear how neural circuits encode complex time-varying patterns. We show that by tuning the weights of a recurrent neural network (RNN), it can recognize and then transcribe spoken digits. The model elucidates how neural dynamics in cortical networks may resolve three fundamental challenges: first, encode multiple time-varying sensory and motor patterns as stable neural trajectories; second, generalize across relevant spatial features; third, identify the same stimuli played at different speeds—we show that this temporal invariance emerges because the recurrent dynamics generate neural trajectories with appropriately modulated angular velocities. Together our results generate testable predictions as to how recurrent networks may use different mechanisms to generalize across the relevant spatial and temporal features of complex time-varying stimuli. PMID:29537963

Gaussian curvature directs the distribution of spontaneous curvature on bilayer membrane necks.

PubMed

Chabanon, Morgan; Rangamani, Padmini

2018-03-28

Formation of membrane necks is crucial for fission and fusion in lipid bilayers. In this work, we seek to answer the following fundamental question: what is the relationship between protein-induced spontaneous mean curvature and the Gaussian curvature at a membrane neck? Using an augmented Helfrich model for lipid bilayers to include membrane-protein interaction, we solve the shape equation on catenoids to find the field of spontaneous curvature that satisfies mechanical equilibrium of membrane necks. In this case, the shape equation reduces to a variable coefficient Helmholtz equation for spontaneous curvature, where the source term is proportional to the Gaussian curvature. We show how this latter quantity is responsible for non-uniform distribution of spontaneous curvature in minimal surfaces. We then explore the energetics of catenoids with different spontaneous curvature boundary conditions and geometric asymmetries to show how heterogeneities in spontaneous curvature distribution can couple with Gaussian curvature to result in membrane necks of different geometries.

Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour

PubMed Central

Vogel, David; Nicolis, Stamatios C.; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J. T.; Dussutour, Audrey

2015-01-01

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: ‘slow–regular–social’, ‘fast–regular–social’ and ‘fast–irregular–asocial’. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. PMID:26609088

The Emergence of Relationship-based Cooperation

NASA Astrophysics Data System (ADS)

Xu, Bo; Wang, Jianwei

2015-11-01

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality.

Encoding sensory and motor patterns as time-invariant trajectories in recurrent neural networks.

PubMed

Goudar, Vishwa; Buonomano, Dean V

2018-03-14

Much of the information the brain processes and stores is temporal in nature-a spoken word or a handwritten signature, for example, is defined by how it unfolds in time. However, it remains unclear how neural circuits encode complex time-varying patterns. We show that by tuning the weights of a recurrent neural network (RNN), it can recognize and then transcribe spoken digits. The model elucidates how neural dynamics in cortical networks may resolve three fundamental challenges: first, encode multiple time-varying sensory and motor patterns as stable neural trajectories; second, generalize across relevant spatial features; third, identify the same stimuli played at different speeds-we show that this temporal invariance emerges because the recurrent dynamics generate neural trajectories with appropriately modulated angular velocities. Together our results generate testable predictions as to how recurrent networks may use different mechanisms to generalize across the relevant spatial and temporal features of complex time-varying stimuli. © 2018, Goudar et al.

A new nonlinear model for pitch perception

NASA Astrophysics Data System (ADS)

Cartwright, Julyan H. E.; González, Diego L.; Piro, Oreste

The ability of the auditory system to perceive the fundamental frequency of a sound even when this frequency is removed from the stimulus is an interesting phenomenon related to the pitch of complex sounds. This capability is known as residue or virtual pitch perception and was first reported last century in the pioneering work of Seebeck. It is residue perception that allows one to listen to music with small transistor radios, which in general have a very poor and sometimes negligible response to low frequencies. The first attempt, due to von Helmholtz, to explain the residue as a nonlinear effect in the ear considered it to originate from difference combination tones. But later experiments showed that the residue does not coincide with a difference combination tone, and nonlinear theories were abandoned. However, in this paper we use recent results from the theory of nonlinear dynamical systems to show that physical frequencies produced by generic nonlinear oscillators acted upon by two independent periodic excitations can reproduce with great precision most of the experimental data about the residue.

Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour.

PubMed

Vogel, David; Nicolis, Stamatios C; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J T; Dussutour, Audrey

2015-11-22

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: 'slow-regular-social', 'fast-regular-social' and 'fast-irregular-asocial'. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. © 2015 The Author(s).

Isolation of Optically Targeted Single Bacteria by Application of Fluidic Force Microscopy to Aerobic Anoxygenic Phototrophs from the Phyllosphere

PubMed Central

Stiefel, Philipp; Zambelli, Tomaso

2013-01-01

In their natural environment, bacteria often behave differently than they do under laboratory conditions. To gain insight into the physiology of bacteria in situ, dedicated approaches are required to monitor their adaptations and specific behaviors under environmental conditions. Optical microscopy is crucial for the observation of fundamental characteristics of bacteria, such as cell shape, size, and marker gene expression. Here, fluidic force microscopy (FluidFM) was exploited to isolate optically selected bacteria for subsequent identification and characterization. In this study, bacteriochlorophyll-producing bacteria, which can be visualized due to their characteristic fluorescence in the infrared range, were isolated from leaf washes. Bacterial communities from the phyllosphere were investigated because they harbor genes indicative of aerobic anoxygenic photosynthesis. Our data show that different species of Methylobacterium express their photosystem in planta, and they show a distinct pattern of bacteriochlorophyll production under laboratory conditions that is dependent on supplied carbon sources. PMID:23770907

The Emergence of Relationship-based Cooperation

PubMed Central

Xu, Bo; Wang, Jianwei

2015-01-01

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality. PMID:26567904

Thermodynamics fundamentals of energy conversion

NASA Astrophysics Data System (ADS)

Dan, Nicolae

The work reported in the chapters 1-5 focuses on the fundamentals of heat transfer, fluid dynamics, thermodynamics and electrical phenomena related to the conversion of one form of energy to another. Chapter 6 is a re-examination of the fundamental heat transfer problem of how to connect a finite-size heat generating volume to a concentrated sink. Chapter 1 extends to electrical machines the combined thermodynamics and heat transfer optimization approach that has been developed for heat engines. The conversion efficiency at maximum power is 1/2. When, as in specific applications, the operating temperature of windings must not exceed a specified level, the power output is lower and efficiency higher. Chapter 2 addresses the fundamental problem of determining the optimal history (regime of operation) of a battery so that the work output is maximum. Chapters 3 and 4 report the energy conversion aspects of an expanding mixture of hot particles, steam and liquid water. At the elemental level, steam annuli develop around the spherical drops as time increases. At the mixture level, the density decreases while the pressure and velocity increases. Chapter 4 describes numerically, based on the finite element method, the time evolution of the expanding mixture of hot spherical particles, steam and water. The fluid particles are moved in time in a Lagrangian manner to simulate the change of the domain configuration. Chapter 5 describes the process of thermal interaction between the molten material and water. In the second part of the chapter the model accounts for the irreversibility due to the flow of the mixture through the cracks of the mixing vessel. The approach presented in this chapter is based on exergy analysis and represents a departure from the line of inquiry that was followed in chapters 3-4. Chapter 6 shows that the geometry of the heat flow path between a volume and one point can be optimized in two fundamentally different ways. In the "growth" method the structure is optimized starting from the smallest volume element of fixed size. In "design" method the overall volume is fixed, and the designer works "inward" by increasing the internal complexity of the paths for heat flow.

Robustness analysis of elastoplastic structure subjected to double impulse

NASA Astrophysics Data System (ADS)

Kanno, Yoshihiro; Takewaki, Izuru

2016-11-01

The double impulse has extensively been used to evaluate the critical response of an elastoplastic structure against a pulse-type input, including near-fault earthquake ground motions. In this paper, we propose a robustness assessment method for elastoplastic single-degree-of-freedom structures subjected to the double impulse input. Uncertainties in the initial velocity of the input, as well as the natural frequency and the strength of the structure, are considered. As fundamental properties of the structural robustness, we show monotonicity of the robustness measure with respect to the natural frequency. In contrast, we show that robustness is not necessarily improved even if the structural strength is increased. Moreover, the robustness preference between two structures with different values of structural strength can possibly reverse when the performance requirement is changed.

Rotor Hover Performance and Flowfield Measurements with Untwisted and Highly-Twisted Blades

NASA Technical Reports Server (NTRS)

Ramasamy, Manikandan; Gold, Nili P.; Bhagwat, Mahendra J.

2010-01-01

The flowfield and performance characteristics of highly-twisted blades were analyzed at various thrust conditions to improve the fundamental understanding relating the wake effects on rotor performance. Similar measurements made using untwisted blades served as the baseline case. Twisted blades are known to give better hover performance than untwisted blades at high thrust coefficients typical of those found in full-scale rotors. However, the present experiments were conducted at sufficiently low thrust (beginning from zero thrust), where the untwisted blades showed identical, if not better, performance when compared with the highly-twisted blades. The flowfield measurements showed some key wake differences between the two rotors, as well. These observations when combined with simple blade element momentum theory (also called annular disk momentum theory) helped further the understanding of rotor performance characteristics.

In Situ Neutron Diffraction of Rare-Earth Phosphate Proton Conductors Sr/Ca-doped LaPO4 at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Al-Wahish, Amal; Al-Binni, Usama; Bridges, C. A.; Huq, A.; Bi, Z.; Paranthaman, M. P.; Tang, S.; Kaiser, H.; Mandrus, D.

Acceptor-doped lanthanum orthophosphates are potential candidate electrolytes for proton ceramic fuel cells. We combined neutron powder diffraction (NPD) at elevated temperatures up to 800° C , X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) to investigate the crystal structure, defect structure, thermal stability and surface topography. NPD shows an average bond length distortion in the hydrated samples. We employed Quasi-Elastic Neutron Scattering (QENS) and electrochemical impedance spectroscopy (EIS) to study the proton dynamics of the rare-earth phosphate proton conductors 4.2% Sr/Ca-doped LaPO4. We determined the bulk diffusion and the self-diffusion coefficients. Our results show that QENS and EIS are probing fundamentally different proton diffusion processes. Supported by the U.S. Department of Energy.

Application of a range of turbulence energy models to the determination of M4 tidal current profiles

NASA Astrophysics Data System (ADS)

Xing, Jiuxing; Davies, Alan M.

1996-04-01

A fully nonlinear, three-dimensional hydrodynamic model of the Irish Sea, using a range of turbulence energy sub-models, is used to examine the influence of the turbulence closure method upon the vertical variation of the current profile of the fundamental and higher harmonics of the tide in the region. Computed tidal current profiles are compared with previous calculations using a spectral model with eddy viscosity related to the flow field. The model has a sufficiently fine grid to resolve the advection terms, in particular the advection of turbulence and momentum. Calculations show that the advection of turbulence energy does not have a significant influence upon the current profile of either the fundamental or higher harmonic of the tide, although the advection of momentum is important in the region of headlands. The simplification of the advective terms by only including them in their vertically integrated form does not appear to make a significant difference to current profiles, but does reduce the computational effort by a significant amount. Computed current profiles both for the fundamental and the higher harmonic determined with a prognostic equation for turbulence and an algebraic mixing length formula, are as accurate as those determined with a two prognostic equation model (the so called q2- q2l model), provided the mixing length is specified correctly. A simple, flow-dependent eddy viscosity with a parabolic variation of viscosity also performs equally well.

The converter mechanism of particle acceleration and the maximum energy of cosmic rays

NASA Astrophysics Data System (ADS)

Kocharovsky, Vl. V.; Aharonian, F. A.; Derishev, E. V.; Kocharovsky, V. V.

We consider the fundamental limits on the energy of particles accelerated by electromagnetic forces in various astrophysical objects [1]. We show that accelerator's parameters are strongly limited not only by the particle confinement in large-scale magnetic field or by the difference in electric potentials (generalized Hillas criterion) but also by the curvature and other types of radiative losses of accelerated particles. Optimization of these requirements in terms of accelerator's size and the magnetic field strength results in the ultimate lower limit on the overall source energy budget, which scales as the fifth power of attainable particle energy. It is demonstrated that the curvature gamma-rays accompanying the acceleration gives further restrictions for potential acceleration sites. We compare different acceleration mechanisms and show, that the converter mechanism, which we suggested earlier [2], is the least sensitive to the geometry of the magnetic field in accelerators and allows to reach cosmic-ray energies close to the fundamental limit. The converter mechanism works most efficiently in relativistic shocks or shear flows. It utilizes multiple conversions of charged particles into neutral ones (protons to neutrons and electrons/positrons to photons) and back by means of photon-induced reactions or inelastic nucleon- nucleon collisions. We discuss the properties of gamma-ray radiation, which accompanies acceleration of cosmic rays via the converter mechanism and can provide an evidence for the latter. 1. F.A. Aharonian, A.A. Belyanin, E.V. Derishev, V.V. Kocharovsky, and Vl.V. Kocharovsky, Phys. Rev. D 66, 023005 (2002). 2. E.V. Derishev, F.A. Aharonian, V.V. Kocharovsky, and Vl.V. Kocharovsky, Phys. Rev. D 68, 043003 (2003).

Multisensory object perception in infancy: 4-month-olds perceive a mistuned harmonic as a separate auditory and visual object

PubMed Central

A. Smith, Nicholas; A. Folland, Nicholas; Martinez, Diana M.; Trainor, Laurel J.

2017-01-01

Infants learn to use auditory and visual information to organize the sensory world into identifiable objects with particular locations. Here we use a behavioural method to examine infants' use of harmonicity cues to auditory object perception in a multisensory context. Sounds emitted by different objects sum in the air and the auditory system must figure out which parts of the complex waveform belong to different sources (auditory objects). One important cue to this source separation is that complex tones with pitch typically contain a fundamental frequency and harmonics at integer multiples of the fundamental. Consequently, adults hear a mistuned harmonic in a complex sound as a distinct auditory object (Alain et al., 2003). Previous work by our group demonstrated that 4-month-old infants are also sensitive to this cue. They behaviourally discriminate a complex tone with a mistuned harmonic from the same complex with in-tune harmonics, and show an object-related event-related potential (ERP) electrophysiological (EEG) response to the stimulus with mistuned harmonics. In the present study we use an audiovisual procedure to investigate whether infants perceive a complex tone with an 8% mistuned harmonic as emanating from two objects, rather than merely detecting the mistuned cue. We paired in-tune and mistuned complex tones with visual displays that contained either one or two bouncing balls. Four-month-old infants showed surprise at the incongruous pairings, looking longer at the display of two balls when paired with the in-tune complex and at the display of one ball when paired with the mistuned harmonic complex. We conclude that infants use harmonicity as a cue for source separation when integrating auditory and visual information in object perception. PMID:28346869

The implications of Big Five standing for the distribution of trait manifestation in behavior: fifteen experience-sampling studies and a meta-analysis.

PubMed

Fleeson, William; Gallagher, Patrick

2009-12-01

One of the fundamental questions in personality psychology is whether and how strongly trait standing relates to the traits that people actually manifest in their behavior when faced with real pressures and real consequences of their actions. One reason this question is fundamental is the common belief that traits do not predict how individuals behave, which leads to the reasonable conclusion that traits are not important to study. However, this conclusion is surprising given that there is almost no data on the ability of traits to predict distributions of naturally occurring, representative behaviors of individuals (and that there are many studies showing that traits do indeed predict specific behaviors). The authors describe a meta-analysis of 15 experience-sampling studies, conducted over the course of 8 years, amassing over 20,000 reports of trait manifestation in behavior. Participants reported traits on typical self-report questionnaires, then described their current behavior multiple times per day for several days as the behavior was occurring. Results show that traits, contrary to expectations, were strongly predictive of individual differences in trait manifestation in behavior, predicting average levels with correlations between .42 and .56 (approaching .60 for stringently restricted studies). Several other ways of summarizing trait manifestation in behavior were also predicted from traits. These studies provide evidence that traits are powerful predictors of actual manifestation of traits in behavior.

Fermi resonance in CO2: Mode assignment and quantum nuclear effects from first principles molecular dynamics

NASA Astrophysics Data System (ADS)

Basire, Marie; Mouhat, Félix; Fraux, Guillaume; Bordage, Amélie; Hazemann, Jean-Louis; Louvel, Marion; Spezia, Riccardo; Bonella, Sara; Vuilleumier, Rodolphe

2017-04-01

Vibrational spectroscopy is a fundamental tool to investigate local atomic arrangements and the effect of the environment, provided that the spectral features can be correctly assigned. This can be challenging in experiments and simulations when double peaks are present because they can have different origins. Fermi dyads are a common class of such doublets, stemming from the resonance of the fundamental excitation of a mode with the overtone of another. We present a new, efficient approach to unambiguously characterize Fermi resonances in density functional theory (DFT) based simulations of condensed phase systems. With it, the spectral features can be assigned and the two resonating modes identified. We also show how data from DFT simulations employing classical nuclear dynamics can be post-processed and combined with a perturbative quantum treatment at a finite temperature to include analytically thermal quantum nuclear effects. The inclusion of these effects is crucial to correct some of the qualitative failures of the Newtonian dynamics simulations at a low temperature such as, in particular, the behavior of the frequency splitting of the Fermi dyad. We show, by comparing with experimental data for the paradigmatic case of supercritical CO2, that these thermal quantum effects can be substantial even at ambient conditions and that our scheme provides an accurate and computationally convenient approach to account for them.

The siren song of vocal fundamental frequency for romantic relationships.

PubMed

Weusthoff, Sarah; Baucom, Brian R; Hahlweg, Kurt

2013-01-01

A multitude of factors contribute to why and how romantic relationships are formed as well as whether they ultimately succeed or fail. Drawing on evolutionary models of attraction and speech production as well as integrative models of relationship functioning, this review argues that paralinguistic cues (more specifically the fundamental frequency of the voice) that are initially a strong source of attraction also increase couples' risk for relationship failure. Conceptual similarities and differences between the multiple operationalizations and interpretations of vocal fundamental frequency are discussed and guidelines are presented for understanding both convergent and non-convergent findings. Implications for clinical practice and future research are discussed.

Fundamentals of Pharmacogenetics in Personalized, Precision Medicine.

PubMed

Valdes, Roland; Yin, DeLu Tyler

2016-09-01

This article introduces fundamental principles of pharmacogenetics as applied to personalized and precision medicine. Pharmacogenetics establishes relationships between pharmacology and genetics by connecting phenotypes and genotypes in predicting the response of therapeutics in individual patients. We describe differences between precision and personalized medicine and relate principles of pharmacokinetics and pharmacodynamics to applications in laboratory medicine. We also review basic principles of pharmacogenetics, including its evolution, how it enables the practice of personalized therapeutics, and the role of the clinical laboratory. These fundamentals are a segue for understanding specific clinical applications of pharmacogenetics described in subsequent articles in this issue. Copyright © 2016 Elsevier Inc. All rights reserved.

An Explanation for the Arctic Sea Ice Melt Pond Fractal Transition

NASA Astrophysics Data System (ADS)

Popovic, P.; Abbot, D. S.

2016-12-01

As Arctic sea ice melts during the summer, pools of melt water form on its surface. This decreases the ice's albedo, which signifcantly impacts its subsequent evolution. Understanding this process is essential for buiding accurate sea ice models in GCMs and using them to forecast future changes in sea ice. A feature of melt ponds that helps determine their impact on ice albedo is that they often form complex geometric shapes. One characteristic of their shape, the fractal dimension of the pond boundaries, D, has been shown to transition between the two fundamental limits of D = 1 and D = 2 at some critical pond size. Here, we provide an explanation for this behavior. First, using aerial photographs taken during the SHEBA mission, we show how this fractal transition curve changes with time, and show that there is a qualitative difference in the pond shape as ice transitions from impermeable to permeable. While ice is impermeable, the maximum fractal dimension is less than 2, whereas after it becomes permeable, the maximum fractal dimension becomes very close to 2. We then show how the fractal dimension of the boundary of a collection of overlapping circles placed randomly on a plane also transitions from D = 1 to D = 2 at a size equal to the average size of a single circle. We, therefore, conclude that this transition is a simple geometric consequence of regular shapes connecting. The one physical parameter that can be extracted from the fractal transition curve is the length scale at which transition occurs. Previously, this length scale has been associated with the typical size of snow dunes created on the ice surface during winter. We provide an alternative explanation by noting that the flexural wavelength of the ice poses a fundamental limit on the size of melt ponds on permeable ice. If this is true, melt ponds could be used as a proxy for ice thickness. Finally, we provide some remarks on how to observationally distinguish between the two ideas for what determines the fundamental length scale.

State Public Health Enabling Authorities: Results of a Fundamental Activities Assessment Examining Core and Essential Services

PubMed Central

Hoss, Aila; Menon, Akshara; Corso, Liza

2016-01-01

Context Public health enabling authorities establish the legal foundation for financing, organizing, and delivering public health services. State laws vary in terms of the content, depth, and breadth of these fundamental public health activities. Given this variance, the Institute of Medicine has identified state public health laws as an area that requires further examination. To respond to this call for further examination, the Centers for Disease Control and Prevention’s Public Health Law Program conducted a fundamental activities legal assessment on state public health laws. Objective The goal of the legal assessment was to examine state laws referencing frameworks representing public health department fundamental activities (ie, core and essential services) in an effort to identify, catalog, and describe enabling authorities of state governmental public health systems. Design In 2013, Public Health Law Program staff compiled a list of state statutes and regulations referencing different commonly-recognized public health frameworks of fundamental activities. The legal assessment included state fundamental activities laws available on WestlawNext as of July 2013. The results related to the 10 essential public health services and the 3 core public health functions were confirmed and updated in June 2016. Results Eighteen states reference commonly-recognized frameworks of fundamental activities in their laws. Thirteen states have listed the 10 essential public health services in their laws. Eight of these states have also referenced the 3 core public health functions in their laws. Five states reference only the core public health functions. Conclusions Several states reference fundamental activities in their state laws, particularly through use of the essential services framework. Further work is needed to capture the public health laws and practices of states that may be performing fundamental activities but without reference to a common framework. PMID:27682724

State Public Health Enabling Authorities: Results of a Fundamental Activities Assessment Examining Core and Essential Services.

PubMed

Hoss, Aila; Menon, Akshara; Corso, Liza

2016-01-01

Public health enabling authorities establish the legal foundation for financing, organizing, and delivering public health services. State laws vary in terms of the content, depth, and breadth of these fundamental public health activities. Given this variance, the Institute of Medicine has identified state public health laws as an area that requires further examination. To respond to this call for further examination, the Centers for Disease Control and Prevention's Public Health Law Program conducted a fundamental activities legal assessment on state public health laws. The goal of the legal assessment was to examine state laws referencing frameworks representing public health department fundamental activities (ie, core and essential services) in an effort to identify, catalog, and describe enabling authorities of state governmental public health systems. In 2013, Public Health Law Program staff compiled a list of state statutes and regulations referencing different commonly-recognized public health frameworks of fundamental activities. The legal assessment included state fundamental activities laws available on WestlawNext as of July 2013. The results related to the 10 essential public health services and the 3 core public health functions were confirmed and updated in June 2016. Eighteen states reference commonly-recognized frameworks of fundamental activities in their laws. Thirteen states have listed the 10 essential public health services in their laws. Eight of these states have also referenced the 3 core public health functions in their laws. Five states reference only the core public health functions. Several states reference fundamental activities in their state laws, particularly through use of the essential services framework. Further work is needed to capture the public health laws and practices of states that may be performing fundamental activities but without reference to a common framework.

What they say and what they do: comparing physical activity across the USA, England and the Netherlands.

PubMed

Kapteyn, Arie; Banks, James; Hamer, Mark; Smith, James P; Steptoe, Andrew; van Soest, Arthur; Koster, Annemarie; Htay Wah, Saw

2018-06-01

Physical activity (PA) is important for maintaining health, but there are fundamental unanswered questions on how best it should be measured. We measured PA in the Netherlands (n=748), the USA (n=540) and England (n=254), both by a 7 day wrist-worn accelerometer and by self-reports. The self-reports included a global self-report on PA and a report on the frequency of vigorous, moderate and mild activity. The self-reported data showed only minor differences across countries and across groups within countries (such as different age groups or working vs non-working respondents). The accelerometer data, however, showed large differences; the Dutch and English appeared to be much more physically active than Americans h (For instance, among respondents aged 50 years or older 38% of Americans are in the lowest activity quintile of the Dutch distribution). In addition, accelerometer data showed a sharp decline of PA with age, while no such pattern was observed in self-reports. The differences between objective measures and self-reports occurred for both types of self-reports. It is clear that self-reports and objective measures tell vastly different stories, suggesting that across countries people use different response scales when answering questions about how physically active they are. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A Morphological and Morphometric Study of Bite Marks Caused by Mice (Mus Musculus) on Different Baits for Forensic Purposes.

PubMed

Toledo, Víctor A; Fonseca, Gabriel M; González, Paula A; Ibarra, Luis; Torres, Francisco J; Sáez, Pedro L

2017-03-01

In animal bites, the dental attributes can be fundamental in identifying the marks made by various species on different matrices. Although rodent bite marks have been studied in the context of postmortem interference, little research has used different baits to analyze these marks linking not only specific behavior patterns but also the possibility of structural damage. Twenty mice (Mus musculus) were exposed to different baits to study their bite marks in a controlled model. The known pattern of parallel and multiple grooves has been seen in all baits, but polyvinyl chloride and fiber-optic cable were significantly different between each other and the other baits. Some baits showed patterns of anchorage of the upper incisors and space between the lower incisors when gnawing. This technical note represents a novel model of analysis where veterinarians and/or dentists may be asked to give an opinion on alleged animal bite marks. © 2016 American Academy of Forensic Sciences.

Lunar science - The Apollo legacy

NASA Technical Reports Server (NTRS)

Burnett, D. S.

1975-01-01

The progress made in answering a list of fundamental lunar problems is considered, taking into account the nature of the differences in highlands and mare materials, the chemical composition of the moon, the density and internal structure of the moon, and the state of evolution of the moon. Attention is also given to a number of unanticipated results provided by lunar science. Findings concerning an ancient paleomagnetic field are discussed along with the characteristics of exotic components in the regolith, fundamental material differences observed in lunar surface layers, microcraters, and questions regarding an enhanced iron emission in solar flares.