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Sample records for rate modulation rate

  1. NREL module energy rating methodology

    SciTech Connect

    Whitaker, C.; Newmiller, J.; Kroposki, B.

    1995-11-01

    The goals of this project were to develop a tool for: evaluating one module in different climates; comparing different modules; provide a Q&D method for estimating periodic energy production; provide an achievable module rating; provide an incentive for manufacturers to optimize modules to non-STC conditions; and to have a consensus-based, NREL-sponsored activity. The approach taken was to simulate module energy for five reference days of various weather conditions. A performance model was developed.

  2. Unified Technical Concepts. Module 3: Rate.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This concept module on rate is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each energy system. This…

  3. Photovoltaic module energy rating methodology development

    SciTech Connect

    Kroposki, B.; Myers, D.; Emery, K.; Mrig, L.; Whitaker, C.; Newmiller, J.

    1996-05-01

    A consensus-based methodology to calculate the energy output of a PV module will be described in this paper. The methodology develops a simple measure of PV module performance that provides for a realistic estimate of how a module will perform in specific applications. The approach makes use of the weather data profiles that describe conditions throughout the United States and emphasizes performance differences between various module types. An industry-representative Technical Review Committee has been assembled to provide feedback and guidance on the strawman and final approach used in developing the methodology.

  4. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    PubMed Central

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  5. Detection and rate discrimination of amplitude modulation in electrical hearing.

    PubMed

    Chatterjee, Monita; Oberzut, Cherish

    2011-09-01

    Three experiments were designed to examine temporal envelope processing by cochlear implant (CI) listeners. In experiment 1, the hypothesis that listeners' modulation sensitivity would in part determine their ability to discriminate between temporal modulation rates was examined. Temporal modulation transfer functions (TMTFs) obtained in an amplitude modulation detection (AMD) task were compared to threshold functions obtained in an amplitude modulation rate discrimination (AMRD) task. Statistically significant nonlinear correlations were observed between the two measures. In experiment 2, results of loudness-balancing showed small increases in the loudness of modulated over unmodulated stimuli beyond a modulation depth of 16%. Results of experiment 3 indicated small but statistically significant effects of level-roving on the overall gain of the TMTF, but no impact of level-roving on the average shape of the TMTF across subjects. This suggested that level-roving simply increased the task difficulty for most listeners, but did not indicate increased use of intensity cues under more challenging conditions. Data obtained with one subject, however, suggested that the most sensitive listeners may derive some benefit from intensity cues in these tasks. Overall, results indicated that intensity cues did not play an important role in temporal envelope processing by the average CI listener. PMID:21895095

  6. Symbol rate identification for auxiliary amplitude modulation optical signal

    NASA Astrophysics Data System (ADS)

    Wei, Junyu; Dong, Zhi; Huang, Zhiping; Zhang, Yimeng

    2016-09-01

    In this paper, we creatively propose and demonstrate a method for symbol rate identification (SRI) of auxiliary amplitude modulation (AAM) optical signal based on asynchronous delay-tap sampling (ADTS) and average magnitude difference function (AMDF). The method can accurately estimate symbol rate and has large transmission impairments tolerance. Furthermore, it can be realized in the digital signal processor (DSP) with low logical resources because of multiplication-free. In order to improve the accuracy of SRI, the peak to valley ratio (PTVR) of AMDF is introduced into our method for blind chromatic dispersion (CD) compensation. The results of the numerical simulations show that the overall maximum SRI error is smaller 0.079% for return-to-zero (RZ) on-off keying (OOK), RZ differential phase-shift keying (DPSK), RZ differential quadrature phase-shift keying (DQPSK) and RZ 16-ary quadrature amplitude modulation (QAM) with 50% duty cycles.

  7. Enhanced modulation rates via field modulation in spin torque nano-oscillators

    NASA Astrophysics Data System (ADS)

    Purbawati, A.; Garcia-Sanchez, F.; Buda-Prejbeanu, L. D.; Ebels, U.

    2016-03-01

    Spin Transfer Nano-Oscillators (STNOs) are promising candidates for telecommunications applications due to their frequency tuning capabilities via either a dc current or an applied field. This frequency tuning is of interest for Frequency Shift Keying concepts to be used in wireless communication schemes or in read head applications. For these technological applications, one important parameter is the characterization of the maximum achievable rate at which an STNO can respond to a modulating signal, such as current or field. Previous studies of in-plane magnetized STNOs on frequency modulation via an rf current revealed that the maximum achievable rate is limited by the amplitude relaxation rate Γp, which gives the time scale over which amplitude fluctuations are damped out. This might be a limitation for applications. Here, we demonstrate via numerical simulation that application of an additional rf field is an alternative way for modulation of the in-plane magnetized STNO configuration, which has the advantage that frequency modulation is not limited by the amplitude relaxation rate, so that higher modulation rates above GHz are achievable. This occurs when the modulating rf field is oriented along the easy axis (longitudinal rf field). Tilting the direction of the modulating rf field in-plane and perpendicularly with respect to the easy axis (transverse rf field), the modulation is again limited by the amplitude relaxation rate similar to the response observed in current modulation.

  8. Contact rate modulates foraging efficiency in leaf cutting ants

    PubMed Central

    Bouchebti, S.; Ferrere, S.; Vittori, K.; Latil, G.; Dussutour, A.; Fourcassié, V.

    2015-01-01

    Lane segregation is rarely observed in animals that move in bidirectional flows. Consequently, these animals generally experience a high rate of head-on collisions during their journeys. Although these collisions have a cost (each collision induces a delay resulting in a decrease of individual speed), they could also have a benefit by promoting information transfer between individuals. Here we explore the impact of head-on collisions in leaf-cutting ants moving on foraging trails by artificially decreasing the rate of head-on collisions between individuals. We show that head-on collisions do not influence the rate of recruitment in these ants but do influence foraging efficiency, i.e. the proportion of ants returning to the nest with a leaf fragment. Surprisingly, both unladen and laden ants returning to the nest participate in the modulation of foraging efficiency: foraging efficiency decreases when the rate of contacts with both nestbound laden or unladen ants decreases. These results suggest that outgoing ants are able to collect information from inbound ants even when these latter do not carry any leaf fragment and that this information can influence their foraging decisions when reaching the end of the trail. PMID:26686557

  9. Contact rate modulates foraging efficiency in leaf cutting ants.

    PubMed

    Bouchebti, S; Ferrere, S; Vittori, K; Latil, G; Dussutour, A; Fourcassié, V

    2015-01-01

    Lane segregation is rarely observed in animals that move in bidirectional flows. Consequently, these animals generally experience a high rate of head-on collisions during their journeys. Although these collisions have a cost (each collision induces a delay resulting in a decrease of individual speed), they could also have a benefit by promoting information transfer between individuals. Here we explore the impact of head-on collisions in leaf-cutting ants moving on foraging trails by artificially decreasing the rate of head-on collisions between individuals. We show that head-on collisions do not influence the rate of recruitment in these ants but do influence foraging efficiency, i.e. the proportion of ants returning to the nest with a leaf fragment. Surprisingly, both unladen and laden ants returning to the nest participate in the modulation of foraging efficiency: foraging efficiency decreases when the rate of contacts with both nestbound laden or unladen ants decreases. These results suggest that outgoing ants are able to collect information from inbound ants even when these latter do not carry any leaf fragment and that this information can influence their foraging decisions when reaching the end of the trail. PMID:26686557

  10. Heart Rate Variability and Autonomic Modulations in Preeclampsia

    PubMed Central

    Musa, Shaza M.; Adam, Ishag; Lutfi, Mohamed F.

    2016-01-01

    Background Although the exact pathophysiology of preeclampsia is not well understood, autonomic nervous system imbalance is suggested as one of the main factors. Aims To investigate heart rate variability (HRV) and autonomic modulations in Sudanese pregnant women with preeclampsia. Subjects and Methods A case-control study (60 women in each arm) was conducted at Omdurman Maternity Hospital—Sudan, during the period from June to August, 2014. Cases were women presented with preeclampsia and healthy pregnant women were the controls. Studied groups were matched for important determinants of HRV. Natural logarithm (Ln) of total power (TP), high frequency (HF), low frequency (LF) and very low frequency (VLF) were used to determine HRV. Normalized low and high frequencies (LF Norm and HF Norm) were used to evaluate sympathetic and parasympathetic autonomic modulations respectively. Results Patients with preeclampsia achieved significantly higher LF Norm [49.80 (16.25) vs. 44.55 (19.15), P = 0.044] and LnLF/HF [0.04 (0.68) vs. -0.28 (0.91), P = 0.023] readings, but lower HF Norm [49.08 (15.29) vs. 55.87 (19.56), P = 0.012], compared with healthy pregnant women. Although all other HRV measurements were higher in the patients with preeclampsia compared with the controls, only LnVLF [4.50 (1.19) vs. 4.01 (1.06), P = 0.017] and LnLF [4.01 (1.58) vs. 3.49 (1.23), P = 0.040] reached statistical significance. Conclusion The study adds further evidence for the dominant cardiac sympathetic modulations on patients with preeclampsia, probably secondary to parasympathetic withdrawal in this group. However, the higher LnVLF and LnLF readings achieved by preeclamptic women compared with the controls are unexpected in the view that augmented sympathetic modulations usually depresses all HRV parameters including these two measures. PMID:27043306

  11. Dominant Parasympathetic Modulation of Heart Rate and Heart Rate Variability in a Wild-Caught Seabird.

    PubMed

    Carravieri, Alice; Müller, Martina S; Yoda, Ken; Hayama, Shin-Ichi; Yamamoto, Maki

    2016-01-01

    Heart rate (HR) and heart rate variability (HRV) provide noninvasive measures of the relative activity of the parasympathetic nervous system (PNS), which promotes self-maintenance and restoration, and the sympathetic nervous system (SNS), which prepares an animal for danger. The PNS decreases HR, whereas the SNS increases HR. The PNS and SNS also contribute to oscillations in heartbeat intervals at different frequencies, producing HRV. HRV promotes resilience and adjustment capacity in the organism to intrinsic and extrinsic changes. Measuring HRV can reveal the condition and emotional state of animals, including aspects of their stress physiology. Until now, the functioning of the PNS and SNS and their relationship with other physiological systems have been studied almost exclusively in humans. In this study, we tested their influence on HR and HRV for the first time in a wild-caught seabird, the streaked shearwater (Calonectris leucomelas). We analyzed electrocardiograms collected from birds carrying externally attached HR loggers and that received injections that pharmacologically blocked the PNS, the SNS, or both, as well as those that received a saline (sham) injection or no injection (control). The PNS strongly dominated modulation of HR and also HRV across all frequencies, whereas the SNS contributed only slightly to low-frequency oscillations. The saline injection itself acted as a stressor, causing a dramatic drop in PNS activity in HRV and an increase in HR, though PNS activity continued to dominate even during acute stress. Dominant PNS activity is expected for long-lived species, which should employ physiological strategies that minimize somatic deterioration coming from stress. PMID:27327178

  12. Auditory Cortical Plasticity in Learning to Discriminate Modulation Rate

    PubMed Central

    van Wassenhove, Virginie; Nagarajan, Srikantan S.

    2014-01-01

    The discrimination of temporal information in acoustic inputs is a crucial aspect of auditory perception, yet very few studies have focused on auditory perceptual learning of timing properties and associated plasticity in adult auditory cortex. Here, we trained participants on a temporal discrimination task. The main task used a base stimulus (four tones separated by intervals of 200 ms) that had to be distinguished from a target stimulus (four tones with intervals down to ~180 ms). We show that participants’ auditory temporal sensitivity improves with a short amount of training (3 d, 1 h/d). Learning to discriminate temporal modulation rates was accompanied by a systematic amplitude increase of the early auditory evoked responses to trained stimuli, as measured by magnetoencephalography. Additionally, learning and auditory cortex plasticity partially generalized to interval discrimination but not to frequency discrimination. Auditory cortex plasticity associated with short-term perceptual learning was manifested as an enhancement of auditory cortical responses to trained acoustic features only in the trained task. Plasticity was also manifested as induced non-phase–locked high gamma-band power increases in inferior frontal cortex during performance in the trained task. Functional plasticity in auditory cortex is here interpreted as the product of bottom-up and top-down modulations. PMID:17344404

  13. High count rate gamma camera with independent modules

    NASA Astrophysics Data System (ADS)

    Massari, R.; Ucci, A.; Campisi, C.; Scopinaro, F.; Soluri, A.

    2015-11-01

    Advances in nuclear medical imaging are based on the improvements of the detector's performance. Generally the research is focussed on the spatial resolution improvement. However, another important parameter is the acquisition time that can significantly affect performance in some clinical investigation (e.g. first-pass cardiac studies). At present, there are several clinical imaging systems which are able to solve these diagnostic requirements, such as the D-SPECT Cardiac Imaging System (Spectrum Dynamics) or the Nucline Cardiodesk Medical Imaging System (Mediso). Actually, these solutions are organ-specific dedicated systems, while it would be preferable having general purpose planar detectors with high counting rate. Our group has recently introduced the use of scintillation matrices whose size is equal to the overall area of a position sensitive photomultiplier tube (PSPMT) in order to design a modular gamma camera. This study allowed optimising the overall pixel identification by improving and controlling the light collection efficiency of each PSPMT. Although we achieved a solution for the problems about the dead area at the junction of the PSPMTs when they are set side by side. In this paper, we propose a modular gamma camera design as the basis to build large area detectors. The modular detector design allows us to achieve better counting performance. In this approach, each module that is made of one or more PSPMTs, can actually acquire data independently and simultaneously, increasing the overall detection efficiency. To verify the improvement in count rate capability we have built two detectors with a field of view of ~ 5 × 5cm2, by using four R8900-C12 PSPMTs (Hamamatsu Photonics K.K.). Each PSPMT was coupled to a dedicated discrete scintillation structure designed to obtain a good homogeneity, high imaging performance and high efficiency. One of the detectors was designed as a standard gamma camera, while the other was composed by four independent

  14. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  15. Dopamine Modulates Metabolic Rate and Temperature Sensitivity in Drosophila melanogaster

    PubMed Central

    Ueno, Taro; Tomita, Jun; Kume, Shoen; Kume, Kazuhiko

    2012-01-01

    Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shits induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine), which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation. PMID:22347491

  16. Solar modulation of dose rate onboard the Mir station.

    PubMed

    Badhwar, G D; Shurshakov, V A; Tsetlin, V V

    1997-12-01

    Models of the radiation belts that are currently used to estimate exposure for astronauts describe the environment at times of either solar minimum or solar maximum. Static models, constructed using data acquired prior to 1970 during a solar cycle with relatively low solar radio flux, have flux uncertainties of a factor of two to live and dose-rate uncertainties of a factor of about two. The inability of these static models to provide a dynamic description of the radiation belt environment limits our ability to predict radiation exposures for long-duration missions in low earth orbits. In an attempt to add some predictive capability of these models, we studied the measured daily absorbed dose rate on the Mir orbital station over roughly the complete 22nd solar cycle that saw some of the highest solar flux values in the last 40 y. We show that the daily trapped particle dose rate is an approximate power law function of daily atmospheric density. Atmospheric density values are in turn obtained from standard correlation with observed solar radio noise flux. This correlation improves, particularly during periods of high solar activity, if the density at roughly 400 days earlier time is used. This study suggests the possibility of a dose- and flux-predictive trapped-belt model based on atmospheric density. PMID:11542263

  17. Conspecific density modulates the effect of predation on dispersal rates.

    PubMed

    Hammill, Edd; Fitzjohn, Richard G; Srivastava, Diane S

    2015-08-01

    Dispersal decisions underlie the spatial dynamics of metacommunities. Prey individuals may disperse to reduce the risk of either predation or starvation, and both of these risks may depend on conspecific density. Surprisingly, there is little theory examining how dispersal rates should change in response to the combined effects of predation and changes in conspecific density. We develop such a model and show that, under certain conditions, predators may induce dispersal at low prey densities but not high prey densities. We then experimentally manipulate the density of the ciliate Paramecium aurelia and the perceived presence of its predator, the flatworm Stenostomum virginiamum, in a two-patch metacommunity to parameterise the model. Paramecium dispersed in response to Stenostomum at low densities, but they reduced their dispersal in response to predation risk at high predator densities. By applying our model to the empirical data, we show that this switch in dispersal strategy, linked to increases in prey density, occurred because predators increased the difficulty or risk of dispersal. Together, the model and experiment reveal that the effects of predators on dispersal are contingent on prey density. Previous studies have sometimes reported an increase in dispersal rate when predation risk is elevated, and other times a decrease in dispersal rate. Our demonstration of a switch point, with predation risk increasing dispersal at low prey densities but reducing dispersal above a threshold of prey density, may reconcile the diversity of prey dispersal behaviours reported in these previous investigations and observed in nature. PMID:25820788

  18. Encoding of frequency-modulation (FM) rates in human auditory cortex

    PubMed Central

    Okamoto, Hidehiko; Kakigi, Ryusuke

    2015-01-01

    Frequency-modulated sounds play an important role in our daily social life. However, it currently remains unclear whether frequency modulation rates affect neural activity in the human auditory cortex. In the present study, using magnetoencephalography, we investigated the auditory evoked N1m and sustained field responses elicited by temporally repeated and superimposed frequency-modulated sweeps that were matched in the spectral domain, but differed in frequency modulation rates (1, 4, 16, and 64 octaves per sec). The results obtained demonstrated that the higher rate frequency-modulated sweeps elicited the smaller N1m and the larger sustained field responses. Frequency modulation rate had a significant impact on the human brain responses, thereby providing a key for disentangling a series of natural frequency-modulated sounds such as speech and music. PMID:26656920

  19. Constraints on variations in inflaton decay rate from modulated preheating

    NASA Astrophysics Data System (ADS)

    Mazumdar, Arindam; Prasad Modak, Kamakshya

    2016-06-01

    Modulated (p)reheating is thought to be an alternative mechanism for producing super-horizon curvature perturbations in CMB. But large non-gaussianity and iso-curvature perturbations produced by this mechanism rule out its acceptability as the sole process responsible for generating CMB perturbations. We explore the situation where CMB perturbations are mostly generated by usual quantum fluctuations of inflaton during inflation, but a modulated coupling constant between inflaton and a secondary scalar affects the preheating process and produces some extra curvature perturbations. If the modulating scalar field is considered to be a dark matter candidate, coupling constant between the fields has to be unnaturally fine tuned in order to keep the local-form non-gaussianity and the amplitude of iso-curvature perturbations within observational limit; otherwise parameters of the models have to be tightly constrained. Those constraints imply that the curvature perturbations generated by modulated preheating should be less than 15% of the total observed CMB perturbations. On the other hand if the modulating scalar field is not a dark matter candidate, parameters of the models could not be constrained, but the constraints on the maximum amount of the curvature perturbations coming from modulated preheating remain valid.

  20. Extending the data rate of non-line-of-sight UV communication with polarization modulation

    NASA Astrophysics Data System (ADS)

    Yin, Hongwei; Jia, Honghui; Zhang, Hailiang; Wang, Xiaofeng; Chang, Shengli; Yang, Juncai

    2012-10-01

    With low radiation background of solar-blind UV and strong scattering of UV photons by atmospheric particles, UV communication can be made use of to set up a non-line-of-sight (NLOS) free-space optical communication link. Polarization modulation, besides the traditional intensity modulation, is presented to enhance the data rate of the UV communication system. The configuration and the working process of the dually modulated UV communication system with intensity modulation and polarization, the theoretical evaluation of polarization modulation, and a numerical of the scattering matrix are presented, with the conclusion that polarization modulation is achievable. By adding the polarizing devices and changing the coding procedures, the existing singly-modulated UV communication systems with intensity modulation are easily modified to be dually-modulated ones with polarization modulation and intensity modulation. Ideally speaking, the data rate of the dually-modulated UV communication system is the product of the data rate of the singly modulated system and the number of polarization modulation.

  1. Ionospheric Modulation of Venus Express Lightning Detection Rates

    NASA Astrophysics Data System (ADS)

    Hart, Richard A.; Russell, Christopher T.; Zhang, Tielong

    2015-11-01

    Venus Express completed its nearly 9 year campaign at Earth’s sister planet in late 2014. During this period the onboard fluxgate magnetometer collected data up to 64 Hz in frequency while near periapsis. This is the expected frequency range for lightning-generated whistler-mode waves at Venus, between the local electron and ion gyrofrequencies. These waves are right-hand circularly polarized and are guided by the local magnetic field. When the Venusian ionopause is low enough in altitude to reside in the collisional region, the interplanetary magnetic field can get carried down with the ions and magnetize the lower ionosphere. As the field travels towards the terminator it gains a radial component, enabling whistlers to reach higher altitudes and be detected by the spacecraft. The mission covered almost an entire solar cycle and frequently observed a magnetized ionosphere during the solar minimum phase when the ionosphere was weak due to reduced incident EUV. Detection was most common at 250 km altitude where the waves travel more slowly due to reduced ionospheric density. In response they increase in amplitude in order to conserve magnetic energy flux. Here, we examine the changes in the ionospheric properties associated with the evolution of the solar cycle and the rate of detection of these lightning-generated signals.

  2. Combinatorial FSK modulation for power-efficient high-rate communications

    NASA Technical Reports Server (NTRS)

    Wagner, Paul K.; Budinger, James M.; Vanderaar, Mark J.

    1991-01-01

    Deep-space and satellite communications systems must be capable of conveying high-rate data accurately with low transmitter power, often through dispersive channels. A class of noncoherent Combinatorial Frequency Shift Keying (CFSK) modulation schemes is investigated which address these needs. The bit error rate performance of this class of modulation formats is analyzed and compared to the more traditional modulation types. Candidate modulator, demodulator, and digital signal processing (DSP) hardware structures are examined in detail. System-level issues are also discussed.

  3. Solar Modulation of Inner Trapped Belt Radiation Dose Rate

    NASA Astrophysics Data System (ADS)

    Diaz, Abel

    2002-03-01

    The two steady sources of radiation in low Earth orbit are the inner trapped-belt and galactic cosmic radiation (GCR), which present a very significant hazard to the astronauts and flight equipment electronics. The fluxes of GCR and inner trapped-belt particles at a fixed altitude are modulated by solar activity. They decrease with increasing solar activity in general. The mechanism of these two sources of radiation are, however, very different. In this project we shall be concerned with modeling the inner trapped-belt protons. The existing trapped-belt models, namely AP-8 is based on data acquired prior to 1970 during solar cycle 20 with relatively low solar flux. These models describe the environment at solar minimum and solar maximum only. Cycles 21 and 22 were much larger, but no valid radiation model exists for such large values. Moreover, the existing models like AP-8, CRRESPRO, and GOST describe the flux to an accuracy of a factor of two to five. There is clear need to accurately predict radiation exposure of astronauts and equipment at all times between the solar minimum and solar maximum, not only on the short duration Space Shuttle flights, but also the longer term stay onboard the International Space Station. In our approach we are taking into account some important parameters, which are responsible for energy losses of protons within the belts. These energy losses are primarily to electrons and by collisions to atmospheric nuclei. Accordingly the atmospheric density dependence at a certain altitude during a specific solar activity is an important parameter that needs to be accurately incorporated into a realistic model. We are involved in developing such a model, which would enable us to predict the radiation exposure for all occasions.

  4. The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

    2011-01-01

    The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…

  5. High Data Rate OFDM-Based Radio over FSO Communication System Using M-QAM Modulation

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Teixeira, Antonio Luis Jesus

    2015-12-01

    In this paper, we have presented analysis of OFDM-based Radio over FSO Communication System using M-QAM Modulation under different data rate and attenuation. A distance of 1,000 m was achieved at 10 Gbit/s data rate in OFDM-based Radio over FSO Communication System.

  6. Apollo experience report. Guidance and control systems: Orbital rate drive electronics for the Apollo command module and lunar module

    NASA Technical Reports Server (NTRS)

    Parker, R. B.; Sollock, P. E.

    1974-01-01

    A brief record of the development and use of the orbital-rate-drive assembly in the Apollo Program is presented. This device was procured as government-furnished equipment and was used on both the lunar module and the command module. Reviews of design, development, procurement, and flight experience are included.

  7. A Self Rating Scale as a Pre and Post Assessment Tool for Use with Instructional Modules.

    ERIC Educational Resources Information Center

    Gotts, Sandra Harris

    This article describes a self rating pre- and post-assessment instrument that has been developed at the Central Michigan University (CMU). Nine instructional modules have been developed and are being used in science methods courses at CMU. Each module focuses on an identified area of competency for elementary science teachers and contains a…

  8. International PV QA Task Force's Proposed Comparative Rating System for PV Modules: Preprint

    SciTech Connect

    Wohlgemuth, J.; Kurtz, S.

    2014-10-01

    The International PV Quality Assurance Task Force is developing a rating system that provides comparative information about the relative durability of PV modules. Development of accelerated stress tests that can provide such comparative information is seen as a major step toward being able to predict PV module service life. This paper will provide details of the ongoing effort to determine the format of such an overall module rating system. The latest proposal is based on using three distinct climate zones as defined in IEC 60721-2-1 for two different mounting systems. Specific stresses beyond those used in the qualification tests are being developed for each of the selected climate zones.

  9. Voluntary control of breathing does not alter vagal modulation of heart rate

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Evans, J. M.; Bruce, E. N.; Eckberg, D. L.; Knapp, C. F.

    1995-01-01

    Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.

  10. Variable-Rate Ring Convolutional Coded Continuous Phase Modulation Using Puncturing

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Wu, Jun; Zhu, Aiming

    2013-01-01

    In this paper, puncturing technique is used to establish variable-rate ring convolutional coded continuous phase modulation (CPM) systems. Maximum likelihood sequence detectors over both AWGN channels and Rayleigh flat-fading channels are considered. The suggested system provides us with different rates and performance when simple adjustment is taken to the puncturing matrix. Since the performance of the first error event of this system is represented by normalized minimum squared Euclidean distance (NMSED), some typical codes with maximum NMSED are searched and given. The performance of symbol error rate for the suggested system is simulated using computer software, and the results show that this system provides good performance of symbol error rate with variable-rate capabilities in time varying channels. Furthermore, simulation results also prove that the transmission efficiency increases when code rate is decreasing.

  11. Minimizing pattern effects in semiconductor lasers at high rate pulse modulation

    NASA Technical Reports Server (NTRS)

    Torphammar, P.; Tell, R.; Eklund, H.; Johnston, A. R.

    1979-01-01

    This paper deals with analytical and experimental work related to modulation of a semiconductor laser used in high bit rate communication. The approach is based upon minimizing the charge storage effect by a proper choice of the area of the modulating pulses and the bias current. The concept of using additional current pulses to probe for variations in electron density between pulses is investigated. The primary limitation on bit rate is found to be the ability to generate laser drive pulses free of ringing or similar transients. This and the 300 ps pulsewidth, an experimental constraint, limit the bit rate to about 1 Gbit/s. However, by using this approach it appears that bit rates considerably higher than 2 Gbits/s could be reached with sufficiently accurate control of drive pulse shape. It is found that the laser bias and the current pulse area had to be controlled within 1 percent and 10 percent, respectively.

  12. Role of climate and vegetation density in modulating denudation rates in the Himalaya

    NASA Astrophysics Data System (ADS)

    Olen, Stephanie M.; Bookhagen, Bodo; Strecker, Manfred R.

    2016-07-01

    Vegetation has long been hypothesized to influence the nature and rates of surface processes. We test the possible impact of vegetation and climate on denudation rates at orogen scale by taking advantage of a pronounced along-strike gradient in rainfall and vegetation density in the Himalaya. We combine 12 new 10Be denudation rates from the Sutlej Valley and 123 published denudation rates from fluvially-dominated catchments in the Himalaya with remotely-sensed measures of vegetation density and rainfall metrics, and with tectonic and lithologic constraints. In addition, we perform topographic analyses to assess the contribution of vegetation and climate in modulating denudation rates along strike. We observe variations in denudation rates and the relationship between denudation and topography along strike that are most strongly controlled by local rainfall amount and vegetation density, and cannot be explained by along-strike differences in tectonics or lithology. A W-E along-strike decrease in denudation rate variability positively correlates with the seasonality of vegetation density (R = 0.95, p < 0.05), and negatively correlates with mean vegetation density (R = - 0.84, p < 0.05). Vegetation density modulates the topographic response to changing denudation rates, such that the functional relationship between denudation rate and topographic steepness becomes increasingly linear as vegetation density increases. We suggest that while tectonic processes locally control the pattern of denudation rates across strike of the Himalaya (i.e., S-N), along strike of the orogen (i.e., E-W) climate exerts a measurable influence on how denudation rates scatter around long-term, tectonically-controlled erosion, and on the functional relationship between topography and denudation.

  13. Rate-adaptive modulation and coding for optical fiber transmission systems

    NASA Astrophysics Data System (ADS)

    Gho, Gwang-Hyun; Kahn, Joseph M.

    2011-01-01

    Rate-adaptive optical transmission techniques adjust information bit rate based on transmission distance and other factors affecting signal quality. These techniques enable increased bit rates over shorter links, while enabling transmission over longer links when regeneration is not available. They are likely to become more important with increasing network traffic and a continuing evolution toward optically switched mesh networks, which make signal quality more variable. We propose a rate-adaptive scheme using variable-rate forward error correction (FEC) codes and variable constellations with a fixed symbol rate, quantifying how achievable bit rates vary with distance. The scheme uses serially concatenated Reed-Solomon codes and an inner repetition code to vary the code rate, combined with singlecarrier polarization-multiplexed M-ary quadrature amplitude modulation (PM-M-QAM) with variable M and digital coherent detection. A rate adaptation algorithm uses the signal-to-noise ratio (SNR) or the FEC decoder input bit-error ratio (BER) estimated by a receiver to determine the FEC code rate and constellation size that maximizes the information bit rate while satisfying a target FEC decoder output BER and an SNR margin, yielding a peak rate of 200 Gbit/s in a nominal 50-GHz channel bandwidth. We simulate single-channel transmission through a long-haul fiber system incorporating numerous optical switches, evaluating the impact of fiber nonlinearity and bandwidth narrowing. With zero SNR margin, we achieve bit rates of 200/100/50 Gbit/s over distances of 650/2000/3000 km. Compared to an ideal coding scheme, the proposed scheme exhibits a performance gap ranging from about 6.4 dB at 650 km to 7.5 dB at 5000 km.

  14. A Simple Approximation for the Symbol Error Rate of Triangular Quadrature Amplitude Modulation

    NASA Astrophysics Data System (ADS)

    Duy, Tran Trung; Kong, Hyung Yun

    In this paper, we consider the error performance of the regular triangular quadrature amplitude modulation (TQAM). In particular, using an accurate exponential bound of the complementary error function, we derive a simple approximation for the average symbol error rate (SER) of TQAM over Additive White Gaussian Noise (AWGN) and fading channels. The accuracy of our approach is verified by some simulation results.

  15. Model cerebellar granule cells can faithfully transmit modulated firing rate signals

    PubMed Central

    Rössert, Christian; Solinas, Sergio; D'Angelo, Egidio; Dean, Paul; Porrill, John

    2014-01-01

    A crucial assumption of many high-level system models of the cerebellum is that information in the granular layer is encoded in a linear manner. However, granule cells are known for their non-linear and resonant synaptic and intrinsic properties that could potentially impede linear signal transmission. In this modeling study we analyse how electrophysiological granule cell properties and spike sampling influence information coded by firing rate modulation, assuming no signal-related, i.e., uncorrelated inhibitory feedback (open-loop mode). A detailed one-compartment granule cell model was excited in simulation by either direct current or mossy-fiber synaptic inputs. Vestibular signals were represented as tonic inputs to the flocculus modulated at frequencies up to 20 Hz (approximate upper frequency limit of vestibular-ocular reflex, VOR). Model outputs were assessed using estimates of both the transfer function, and the fidelity of input-signal reconstruction measured as variance-accounted-for. The detailed granule cell model with realistic mossy-fiber synaptic inputs could transmit information faithfully and linearly in the frequency range of the vestibular-ocular reflex. This was achieved most simply if the model neurons had a firing rate at least twice the highest required frequency of modulation, but lower rates were also adequate provided a population of neurons was utilized, especially in combination with push-pull coding. The exact number of neurons required for faithful transmission depended on the precise values of firing rate and noise. The model neurons were also able to combine excitatory and inhibitory signals linearly, and could be replaced by a simpler (modified) integrate-and-fire neuron in the case of high tonic firing rates. These findings suggest that granule cells can in principle code modulated firing-rate inputs in a linear manner, and are thus consistent with the high-level adaptive-filter model of the cerebellar microcircuit. PMID:25352777

  16. 40-Gb/s FSK modulated WDM-PON with variable-rate multicast overlay.

    PubMed

    Xin, Xiangjun; Liu, Bo; Zhang, Lijia; Yu, Jianjun

    2011-06-20

    This paper proposes a novel conjugate-driven frequency shift keying (FSK) modulated wavelength division multiplexing passive network (WDM-PON) with variable-rate multicast services. Optical orthogonal frequency division multiplexing (OFDM) is adopted for multicast overlay services with different rate requirements. A differential detection is used for the demodulation of FSK signal, which can eliminate the crosstalk from the OFDM signal. A total 40-Gb/s FSK point to point (P2P) signal and 6.3-Gb/s OFDM overlay with three kinds of variable-rate multicast services are experimentally demonstrated. A physical-layer adaptive identification is proposed for the variable-rate multicast services. After 25 km single mode fiber (SMF) transmission, the power penalties of FSK P2P signal and OFDM multicast overlay are 1.3 dB and 1.7 dB respectively. PMID:21716492

  17. Synchronous-digitization for Video Rate Polarization Modulated Beam Scanning Second Harmonic Generation Microscopy

    PubMed Central

    Sullivan, Shane Z.; DeWalt, Emma L.; Schmitt, Paul D.; Muir, Ryan M.; Simpson, Garth J.

    2016-01-01

    Fast beam-scanning non-linear optical microscopy, coupled with fast (8 MHz) polarization modulation and analytical modeling have enabled simultaneous nonlinear optical Stokes ellipsometry (NOSE) and linear Stokes ellipsometry imaging at video rate (15 Hz). NOSE enables recovery of the complex-valued Jones tensor that describes the polarization-dependent observables, in contrast to polarimetry, in which the polarization stated of the exciting beam is recorded. Each data acquisition consists of 30 images (10 for each detector, with three detectors operating in parallel), each of which corresponds to polarization-dependent results. Processing of this image set by linear fitting contracts down each set of 10 images to a set of 5 parameters for each detector in second harmonic generation (SHG) and three parameters for the transmittance of the fundamental laser beam. Using these parameters, it is possible to recover the Jones tensor elements of the sample at video rate. Video rate imaging is enabled by performing synchronous digitization (SD), in which a PCIe digital oscilloscope card is synchronized to the laser (the laser is the master clock.) Fast polarization modulation was achieved by modulating an electro-optic modulator synchronously with the laser and digitizer, with a simple sine-wave at 1/10th the period of the laser, producing a repeating pattern of 10 polarization states. This approach was validated using Z-cut quartz, and NOSE microscopy was performed for micro-crystals of naproxen. PMID:27041788

  18. Synchronous-digitization for video rate polarization modulated beam scanning second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Sullivan, Shane Z.; DeWalt, Emma L.; Schmitt, Paul D.; Muir, Ryan D.; Simpson, Garth J.

    2015-03-01

    Fast beam-scanning non-linear optical microscopy, coupled with fast (8 MHz) polarization modulation and analytical modeling have enabled simultaneous nonlinear optical Stokes ellipsometry (NOSE) and linear Stokes ellipsometry imaging at video rate (15 Hz). NOSE enables recovery of the complex-valued Jones tensor that describes the polarization-dependent observables, in contrast to polarimetry, in which the polarization stated of the exciting beam is recorded. Each data acquisition consists of 30 images (10 for each detector, with three detectors operating in parallel), each of which corresponds to polarization-dependent results. Processing of this image set by linear fitting contracts down each set of 10 images to a set of 5 parameters for each detector in second harmonic generation (SHG) and three parameters for the transmittance of the fundamental laser beam. Using these parameters, it is possible to recover the Jones tensor elements of the sample at video rate. Video rate imaging is enabled by performing synchronous digitization (SD), in which a PCIe digital oscilloscope card is synchronized to the laser (the laser is the master clock.) Fast polarization modulation was achieved by modulating an electro-optic modulator synchronously with the laser and digitizer, with a simple sine-wave at 1/10th the period of the laser, producing a repeating pattern of 10 polarization states. This approach was validated using Z-cut quartz, and NOSE microscopy was performed for micro-crystals of naproxen.

  19. Search for Event Rate Modulation in XENON100 Electronic Recoil Data

    NASA Astrophysics Data System (ADS)

    Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Anthony, M.; Arazi, L.; Arisaka, K.; Arneodo, F.; Balan, C.; Barrow, P.; Baudis, L.; Bauermeister, B.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Cardoso, J. M. R.; Cervantes, M.; Coderre, D.; Colijn, A. P.; Contreras, H.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Giovanni, A.; Duchovni, E.; Fattori, S.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grignon, C.; Gross, E.; Hampel, W.; Hasterok, C.; Itay, R.; Kaether, F.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Le Calloch, M.; Lellouch, D.; Levinson, L.; Levy, C.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Lyashenko, A.; Macmullin, S.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Mayani, D.; Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Dos Santos, J. M. F.; Sartorelli, G.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen, H.; Teymourian, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Wall, R.; Wang, H.; Weber, M.; Weinheimer, C.; Zhang, Y.; Xenon Collaboration

    2015-08-01

    We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1 σ for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8 σ , the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8 σ .

  20. The radiobiological effect of intra-fraction dose-rate modulation in intensity modulated radiation therapy (IMRT)

    NASA Astrophysics Data System (ADS)

    Bewes, J. M.; Suchowerska, N.; Jackson, M.; Zhang, M.; McKenzie, D. R.

    2008-07-01

    Intensity-modulated radiation therapy (IMRT) achieves optimal dose conformity to the tumor through the use of spatially and temporally modulated radiation fields. In particular, average dose rate and instantaneous dose rate (pulse amplitude) are highly variable within a single IMRT fraction. In this study we isolate these variables and determine their impact on cell survival. Survival was assessed using a clonogenic assay. Two cell lines of differing radiosensitivity were examined: melanoma (MM576) and non-small cell lung cancer (NCI-H460). The survival fraction was observed to be independent of instantaneous dose rate. A statistically significant trend to increased survival was observed as the average dose rate was decreased, for a constant total dose. The results are relevant to IMRT practice, where average treatment times can be significantly extended to allow for movement of the multi-leaf collimator (MLC). Our in vitro study adds to the pool of theoretical evidence for the consequences of protracted treatments. We find that extended delivery times can substantially increase the cell survival. This also suggests that regional variation in the dose-rate history across a tumor, which is inherent to IMRT, will affect radiation dose efficacy.

  1. Reinforcement magnitude modulation of rate dependent effects in pigeons and rats.

    PubMed

    Ginsburg, Brett C; Pinkston, Jonathan W; Lamb, R J

    2011-08-01

    Response rate can influence the behavioral effects of many drugs. Reinforcement magnitude may also influence drug effects. Further, reinforcement magnitude can influence rate-dependent effects. For example, in an earlier report, we showed that rate-dependent effects of two antidepressants depended on reinforcement magnitude. The ability of reinforcement magnitude to interact with rate-dependency has not been well characterized. It is not known whether our previous results are specific to antidepressants or generalize to other drug classes. Here, we further examine rate-magnitude interactions by studying effects of two stimulants (d-amphetamine [0.32-5.6 mg/kg] and cocaine [0.32-10 mg/kg]) and two sedatives (chlordiazepoxide [1.78-32 mg/kg] and pentobarbital [1.0-17.8 mg/kg]) in pigeons responding under a 3-component multiple fixed-interval (FI) 300-s schedule maintained by 2-, 4-, or 8-s of food access. We also examine the effects of d-amphetamine [0.32-3.2 mg/kg] and pentobarbital [1.8-10 mg/kg] in rats responding under a similar multiple FI300-s schedule maintained by 2- or 10- food pellet (45 mg) delivery. In pigeons, cocaine and, to a lesser extent, chlordiazepoxide exerted rate-dependent effects that were diminished by increasing durations of food access. The relationship was less apparent for pentobarbital, and not present for d-amphetamine. In rats, rate-dependent effects of pentobarbital and d-amphetamine were not modulated by reinforcement magnitude. In conclusion, some drugs appear to exert rate-dependent effect which are diminished when reinforcement magnitude is relatively high. Subsequent analysis of the rate-dependency data suggest the effects of reinforcement magnitude may be due to a diminution of drug-induced increases in low-rate behavior that occurs early in the fixed-interval. PMID:21707192

  2. Digitally modulated bit error rate measurement system for microwave component evaluation

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Mary Jo W.; Budinger, James M.

    1989-01-01

    The NASA Lewis Research Center has developed a unique capability for evaluation of the microwave components of a digital communication system. This digitally modulated bit-error-rate (BER) measurement system (DMBERMS) features a continuous data digital BER test set, a data processor, a serial minimum shift keying (SMSK) modem, noise generation, and computer automation. Application of the DMBERMS has provided useful information for the evaluation of existing microwave components and of design goals for future components. The design and applications of this system for digitally modulated BER measurements are discussed.

  3. Dose rate observed on 19-21 October 1989 and its modulation by geophysical effects

    SciTech Connect

    Shea, M.A.; Smart, D.F.; Dachev, T.P.; Petrov, V.M.

    1994-12-31

    The Liulin dosimeter-radiometer on the MIR space station detected the 19 October 1989 high energy solar proton event. These results show the main particle increase contains protons with energies up to about 9 GeV. After the main particle onset the Liulin dosimeter observed a typical geomagnetic cutoff modulation of the dose rate from the solar particles as the MIR space station traversed magnetic latitude. When the interplanetary shock and associated solar plasma enveloped the earth on 20 October between 14 and 17 UT the radiation exposure increased significantly due to the lowering of the geomagnetic cutoff. The analysis of this event shows how various geophysical phenomena can significantly modulate the dose rate encountered by earth-orbiting spacecraft.

  4. Dose rate observed on 19-21 October 1989 and its modulation by geophysical effects

    SciTech Connect

    Smart, D.F.; Shea, M.A.; Bankov, N.G.; Petrov, V.M.; Bengin, V.V.

    1996-07-12

    The Liulin dosimeter radiometer on the MIR space station detected the 19 October 1989 high energy solar proton event. These results show that the main particle increase contains protons with energies up to about 9 GeV. After the main particle onset, the Liulin dosimeter observed a typical geomagnetic cut-off modulation of the dose rate from the solar particles as the MIR space station traversed magnetic latitudes. When the interplanetary shock and associated solar plasma enveloped the earth on 20 October between 14 and 17 UT, the radiation exposure increased significantly due to the lowering of the geomagnetic cutoff. The analysis of this event shows how various geophysical phenomena can significantly modulate the dose rate encountered by earth orbiting spacecraft.

  5. The modulation rate transfer function of a harbour porpoise (Phocoena phocoena).

    PubMed

    Linnenschmidt, Meike; Wahlberg, Magnus; Damsgaard Hansen, Janni

    2013-02-01

    During echolocation, toothed whales produce ultrasonic clicks at extremely rapid rates and listen for the returning echoes. The auditory brainstem response (ABR) duration was evaluated in terms of latency between single peaks: 5.5 ms (from peak I to VII), 3.4 ms (I-VI), and 1.4 ms (II-IV). In comparison to the killer whale and the bottlenose dolphin, the ABR of the harbour porpoise has shorter intervals between the peaks and consequently a shorter ABR duration. This indicates that the ABR duration and peak latencies are possibly related to the relative size of the auditory structures of the central nervous system and thus to the animal's size. The ABR to a sinusoidal amplitude modulated stimulus at 125 kHz (sensitivity threshold 63 dB re 1 μPa rms) was evaluated to determine the modulation rate transfer function of a harbour porpoise. The ABR showed distinct envelope following responses up to a modulation rate of 1,900 Hz. The corresponding calculated equivalent rectangular duration of 263 μs indicates a good temporal resolution in the harbour porpoise auditory system similar to the one for the bottlenose dolphin. The results explain how the harbour porpoise can follow clicks and echoes during echolocation with very short inter click intervals. PMID:23149551

  6. Interactive coding of visual spatial frequency and auditory amplitude-modulation rate.

    PubMed

    Guzman-Martinez, Emmanuel; Ortega, Laura; Grabowecky, Marcia; Mossbridge, Julia; Suzuki, Satoru

    2012-03-01

    Spatial frequency is a fundamental visual feature coded in primary visual cortex, relevant for perceiving textures, objects, hierarchical structures, and scenes, as well as for directing attention and eye movements. Temporal amplitude-modulation (AM) rate is a fundamental auditory feature coded in primary auditory cortex, relevant for perceiving auditory objects, scenes, and speech. Spatial frequency and temporal AM rate are thus fundamental building blocks of visual and auditory perception. Recent results suggest that crossmodal interactions are commonplace across the primary sensory cortices and that some of the underlying neural associations develop through consistent multisensory experience such as audio-visually perceiving speech, gender, and objects. We demonstrate that people consistently and absolutely (rather than relatively) match specific auditory AM rates to specific visual spatial frequencies. We further demonstrate that this crossmodal mapping allows amplitude-modulated sounds to guide attention to and modulate awareness of specific visual spatial frequencies. Additional results show that the crossmodal association is approximately linear, based on physical spatial frequency, and generalizes to tactile pulses, suggesting that the association develops through multisensory experience during manual exploration of surfaces. PMID:22326023

  7. Factors Modulating Recovery Rate after Intermittent Tetanic Fatigue in Atrophic Soleus

    NASA Astrophysics Data System (ADS)

    Li, Hui; Jiao, Bo; Yu, Zhibin

    2008-06-01

    To specify the factors modulating the recovery rate after intermittent tetanic fatigue in soleus, and to seek the reasons for the decrease of recovery rate in atrophic soleus, we observed the recovery time course of different types of fatigue in isolated muscle strips. A 10 % or 50 % decrease in maximal contraction tension of tetani was defined respectively as slight or moderate fatigue. Tetanic tension recovery rates after short-term and long-term of slight or moderate fatigue were observed, some pharmacological intervention were also used. The results showed that slight fatigue only induced an inhibition to myofibril, while moderate fatigue induced an inhibition in myofibril and sarcoplasmic reticulum Ca2+ release channels. There were significant decreases in all of the fatigue groups in one-week tail-suspended rats. These suggest that both slight and moderate fatigue inhibit the myofibrils and the sarcoplasmic reticulum Ca2+ release channels in one-week unloaded soleus.

  8. Serial-Turbo-Trellis-Coded Modulation with Rate-1 Inner Code

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Pollara, Fabrizio

    2004-01-01

    Serially concatenated turbo codes have been proposed to satisfy requirements for low bit- and word-error rates and for low (in comparison with related previous codes) complexity of coding and decoding algorithms and thus low complexity of coding and decoding circuitry. These codes are applicable to such high-level modulations as octonary phase-shift keying (8PSK) and 16-state quadrature amplitude modulation (16QAM); the signal product obtained by applying one of these codes to one of these modulations is denoted, generally, as serially concatenated trellis-coded modulation (SCTCM). These codes could be particularly beneficial for communication systems that must be designed and operated subject to limitations on bandwidth and power. Some background information is prerequisite to a meaningful summary of this development. Trellis-coded modulation (TCM) is now a well-established technique in digital communications. A turbo code combines binary component codes (which typically include trellis codes) with interleaving. A turbo code of the type that has been studied prior to this development is composed of parallel concatenated convolutional codes (PCCCs) implemented by two or more constituent systematic encoders joined through one or more interleavers. The input information bits feed the first encoder and, after having been scrambled by the interleaver, enter the second encoder. A code word of a parallel concatenated code consists of the input bits to the first encoder followed by the parity check bits of both encoders. The suboptimal iterative decoding structure for such a code is modular, and consists of a set of concatenated decoding modules one for each constituent code connected through an interleaver identical to the one in the encoder side. Each decoder performs weighted soft decoding of the input sequence. PCCCs yield very large coding gains at the cost of a reduction in the data rate and/or an increase in bandwidth.

  9. Density of Wild Prey Modulates Lynx Kill Rates on Free-Ranging Domestic Sheep

    PubMed Central

    Odden, John; Nilsen, Erlend B.; Linnell, John D. C.

    2013-01-01

    Understanding the factors shaping the dynamics of carnivore–livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed. PMID:24278123

  10. Feasibility study of volumetric modulated arc therapy with constant dose rate for endometrial cancer

    SciTech Connect

    Yang, Ruijie; Wang, Junjie; Xu, Feng; Li, Hua; Zhang, Xile

    2013-10-01

    To investigate the feasibility, efficiency, and delivery accuracy of volumetric modulated arc therapy with constant dose rate (VMAT-CDR) for whole-pelvic radiotherapy (WPRT) of endometrial cancer. The nine-field intensity-modulated radiotherapy (IMRT), VMAT with variable dose-rate (VMAT-VDR), and VMAT-CDR plans were created for 9 patients with endometrial cancer undergoing WPRT. The dose distribution of planning target volume (PTV), organs at risk (OARs), and normal tissue (NT) were compared. The monitor units (MUs) and treatment delivery time were also evaluated. For each VMAT-CDR plan, a dry run was performed to assess the dosimetric accuracy with MatriXX from IBA. Compared with IMRT, the VMAT-CDR plans delivered a slightly greater V{sub 20} of the bowel, bladder, pelvis bone, and NT, but significantly decreased the dose to the high-dose region of the rectum and pelvis bone. The MUs decreased from 1105 with IMRT to 628 with VMAT-CDR. The delivery time also decreased from 9.5 to 3.2 minutes. The average gamma pass rate was 95.6% at the 3%/3 mm criteria with MatriXX pretreatment verification for 9 patients. VMAT-CDR can achieve comparable plan quality with significant shorter delivery time and smaller number of MUs compared with IMRT for patients with endometrial cancer undergoing WPRT. It can be accurately delivered and be an alternative to IMRT on the linear accelerator without VDR capability.

  11. Feasibility study of volumetric modulated arc therapy with constant dose rate for endometrial cancer.

    PubMed

    Yang, Ruijie; Wang, Junjie; Xu, Feng; Li, Hua; Zhang, Xile

    2013-01-01

    To investigate the feasibility, efficiency, and delivery accuracy of volumetric modulated arc therapy with constant dose rate (VMAT-CDR) for whole-pelvic radiotherapy (WPRT) of endometrial cancer. The nine-field intensity-modulated radiotherapy (IMRT), VMAT with variable dose-rate (VMAT-VDR), and VMAT-CDR plans were created for 9 patients with endometrial cancer undergoing WPRT. The dose distribution of planning target volume (PTV), organs at risk (OARs), and normal tissue (NT) were compared. The monitor units (MUs) and treatment delivery time were also evaluated. For each VMAT-CDR plan, a dry run was performed to assess the dosimetric accuracy with MatriXX from IBA. Compared with IMRT, the VMAT-CDR plans delivered a slightly greater V20 of the bowel, bladder, pelvis bone, and NT, but significantly decreased the dose to the high-dose region of the rectum and pelvis bone. The MUs decreased from 1105 with IMRT to 628 with VMAT-CDR. The delivery time also decreased from 9.5 to 3.2 minutes. The average gamma pass rate was 95.6% at the 3%/3mm criteria with MatriXX pretreatment verification for 9 patients. VMAT-CDR can achieve comparable plan quality with significant shorter delivery time and smaller number of MUs compared with IMRT for patients with endometrial cancer undergoing WPRT. It can be accurately delivered and be an alternative to IMRT on the linear accelerator without VDR capability. PMID:23669454

  12. Oxytocin receptor gene polymorphism modulates the effects of social support on heart rate variability.

    PubMed

    Kanthak, Magdalena K; Chen, Frances S; Kumsta, Robert; Hill, LaBarron K; Thayer, Julian F; Heinrichs, Markus

    2016-05-01

    A large body of empirical research has demonstrated stress-buffering effects of social support. However, recent studies suggest that genetic variation of the oxytocin system (specifically, a common single nucleotide polymorphism, rs53576, of the oxytocin receptor gene) modulates the efficacy of social support. The timing and neurobiological basis of this genetic modulation were investigated using a standardized, laboratory-based psychological stress procedure (Trier Social Stress Test for Groups, TSST-G). To index potential stress buffering effects of social support mediated by the oxytocin system, heart rate variability (HRV) was obtained before and during the TSST-G from 40 healthy participants. Results indicate that social support is associated with higher HRV only in G allele carriers. Specifically, social support increased heart rate variability during direct social interaction and only in individuals with at least one copy of the G allele of rs53576. These findings support the idea that the stress-attenuating effects of social support are modulated by genetic variation of the oxytocin system. PMID:26903384

  13. A Pipelined IP Address Lookup Module for 100 Gbps Line Rates and beyond

    NASA Astrophysics Data System (ADS)

    Teuchert, Domenic; Hauger, Simon

    New Internet services and technologies call for higher packet switching capacities in the core network. Thus, a performance bottleneck arises at the backbone routers, as forwarding of Internet Protocol (IP) packets requires to search the most specific entry in a forwarding table that contains up to several hundred thousand address prefixes. The Tree Bitmap algorithm provides a well-balanced solution in respect of storage needs as well as of search and update complexity. In this paper, we present a pipelined lookup module based on this algorithm, which allows for an easy adaption to diverse protocol and hardware constraints. We determined the pipelining degree required to achieve the throughput for a 100 Gbps router line card by analyzing a representative sub-unit for various configured sizes. The module supports IPv4 and IPv6 configurations providing this throughput, as we determined the performance of our design to achieve a processing rate of 178 million packets per second.

  14. 60-GHz integrated-circuit high data rate quadriphase shift keying exciter and modulator

    NASA Technical Reports Server (NTRS)

    Grote, A.; Chang, K.

    1984-01-01

    An integrated-circuit quadriphase shift keying (QPSK) exciter and modulator have demonstrated excellent performance directly modulating a carrier frequency of 60 GHz with an output phase error of less than 3 degrees and maximum amplitude error of 0.5 dB. The circuit consists of a 60-GHz Gunn VCO phase-locked to a low-frequency reference source, a 4th subharmonic mixer, and a QPSK modlator packaged into a small volume of 1.8 x 2.5 x 0.35 in. The use of microstrip has the advantages of small size, light-weight, and low-cost fabrication. The unit has the potential for multigigabit data rate applications.

  15. High repetition rate optical switch using an electroabsorption modulator in TOAD configuration

    NASA Astrophysics Data System (ADS)

    Huo, Li; Yang, Yanfu; Lou, Caiyun; Gao, Yizhi

    2007-07-01

    A novel optical switch featured with high repetition rate, short switching window width, and high contrast ratio is proposed and demonstrated for the first time by placing an electroabsorption modulator (EAM) in a terahertz optical asymmetric demultiplexer (TOAD) configuration. The feasibility and main characteristics of the switch are investigated by numerical simulations and experiments. With this EAM-based TOAD, an error-free return-to-zero signal wavelength conversion with 0.62 dB power penalty at 20 Gbit/s is demonstrated.

  16. Development of high data readout rate pixel module and detector hybridization at Fermilab

    SciTech Connect

    Sergio Zimmermann et al.

    2001-03-20

    This paper describes the baseline design and a variation of the pixel module to handle the data rate required for the BTeV experiment at Fermilab. The present prototype has shown good electrical performance characteristics. Indium bump bonding is proven to be capable of successful fabrication at 50 micron pitch on real detectors. For solder bumps at 50 micron pitch, much better results have been obtained with the fluxless PADS processed detectors. The results are adequate for our needs and our tests have validated it as a viable technology.

  17. Rate-equation analysis for the frequency-chirp-to-modulated-power ratio of a semiconductor-diode laser

    SciTech Connect

    Welford, D.R.

    1985-11-01

    An expression for the frequency chirp to modulated power ratio (CPR) is derived from a rate-equation analysis of the small-signal, injection-current modulation in a semiconductor diode laser. The model includes the effect of lateral carrier diffusion across the active region of the laser diode. The modulation-frequency dependence of the CPR is flat from dc to a few hundred megahertz, beyond which it is proportional to the modulation frequency.

  18. A rate equation analysis for the frequency chirp to modulated power ratio of a semiconductor diode laser

    SciTech Connect

    Welford, D.

    1985-11-01

    An expression for the frequency chirp to modulated power ratio (CPR) is derived from a rate equation analysis of the small-signal, injection current modulation in a semiconductor diode laser. The model includes the effect of lateral carrier diffusion across the active region of the laser diode. The modulation frequency dependence of the CPR is flat from dc to a few hundred megahertz, beyond which it is proportional to the modulation frequency.

  19. High-rate-long-distance fiber-optic communication based on advanced modulation techniques.

    PubMed

    Ivankovski, Y; Mendlovic, D

    1999-09-10

    The presence of fiber attenuation and chromatic dispersion is one of the major design aspects of fiber-optic communication systems when one addresses high-rate and long-distance digital data transmission. Conventional digital communication systems implement a modulation technique that generates light pulses at the fiber input end and tries to detect them at the fiber output end. Here an advanced modulation transmission system is developed based on knowledge of the exact dispersion parameters of the fiber and the principles of space-time mathematical analogy. The information encodes the phase of the input light beam (a continuous laser beam). This phase is designed such that, when the signal is transmitted through a fiber with a given chromatic dispersion, high peak pulses emerge at the output, which follows a desired bit pattern. Thus the continuous input energy is concentrated into short time intervals in which the information needs to be represented at the output. The proposed method provides a high rate-distance product even for fibers with high dispersion parameters, high power at the output, and also unique protection properties. Theoretical analysis of the proposed method, computer simulations, and some design aspects are given. PMID:18324062

  20. Experimental study on trace chemical contaminant generation rates of human metabolism in spacecraft crew module

    NASA Astrophysics Data System (ADS)

    Lihua, Guo; Xinxing, He; Guoxin, Xu; Xin, Qi

    2012-12-01

    Trace chemical contaminants generated by human metabolism is a major source of contamination in spacecraft crew module. In this research, types and generation rates of pollutants from human metabolism were determined in the Chinese diets. Expired air, skin gas, and sweat of 20 subjects were analyzed at different exercise states in a simulated module. The exercise states were designed according to the basic activities in the orbit of astronauts. Qualitative and quantitative analyses of contaminants generated by human metabolic were performed with gas chromatography/mass spectrometry, gas chromatography and UV spectrophotometer. Sixteen chemical compounds from metabolic sources were found. With the increase in physical load, the concentrations of chemical compounds from human skin and expired air correspondingly increased. The species and the offgassing rates of pollutants from human metabolism are different among the Chinese, Americans and the Russians due to differences in ethnicity and dietary customs. This research provides data to aid in the design, development and operation of China's long duration space mission.

  1. Augmenting data rate performance for higher order modulation in triangular index profile multicore fiber interconnect

    NASA Astrophysics Data System (ADS)

    Mishra, Jitendra K.; Priye, Vishnu; Rahman, B. M. A.

    2016-07-01

    A triangular profile multicore fiber (MCF) optical interconnect (OI) is investigated to augment performance that typically degrades at high data rates for higher order modulation in a short reach transmission system. Firstly, probability density functions (PDFs) variation with inter-core crosstalk is calculated for 8-core MCF OI with different index profile in the core and it was observed that the triangular profile MCF OI is the most crosstalk tolerant. Next, symbol error probability (SEP) for higher order quadrature phase shift keying (QPSK) modulated signal due to inter-core crosstalk is analytically obtained and their dependence on typical characteristic parameters are examined. Further, numerical simulations are carried out to compare the error performance of QPSK for step index and triangular index MCF OI by generating eye diagram at 40 Gbps per channel. Finally, it is shown that MCF OI with triangular index profile supporting QPSK has double spectral efficiency with tolerable trade off in SEP as compared with those of binary phase shift keying (BPSK) at high data rates which is scalable up to 5 Tbps.

  2. Increasing the information rates of optical communications via coded modulation: a study of transceiver performance

    NASA Astrophysics Data System (ADS)

    Maher, Robert; Alvarado, Alex; Lavery, Domaniç; Bayvel, Polina

    2016-02-01

    Optical fibre underpins the global communications infrastructure and has experienced an astonishing evolution over the past four decades, with current commercial systems transmitting data rates in excess of 10 Tb/s over a single fibre core. The continuation of this dramatic growth in throughput has become constrained due to a power dependent nonlinear distortion arising from a phenomenon known as the Kerr effect. The mitigation of fibre nonlinearities is an area of intense research. However, even in the absence of nonlinear distortion, the practical limit on the transmission throughput of a single fibre core is dominated by the finite signal-to-noise ratio (SNR) afforded by current state-of-the-art coherent optical transceivers. Therefore, the key to maximising the number of information bits that can be reliably transmitted over a fibre channel hinges on the simultaneous optimisation of the modulation format and code rate, based on the SNR achieved at the receiver. In this work, we use an information theoretic approach based on the mutual information and the generalised mutual information to characterise a state-of-the-art dual polarisation m-ary quadrature amplitude modulation transceiver and subsequently apply this methodology to a 15-carrier super-channel to achieve the highest throughput (1.125 Tb/s) ever recorded using a single coherent receiver.

  3. Reliable, high repetition rate thyratron grid driver used with a magnetic modulator

    SciTech Connect

    Hill, J.V.; Ball, D.G.; Garrett, D.N.

    1991-06-14

    The Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory uses a magnetic modulator switched by a high voltage thyratron to drive a gas discharge laser. The thyratron trigger source must provide an extremely reliable, low jitter, high- rep-rate grid pulse. This paper describes a thyratron grid driver which delivers a 1.2 kV, 80 ns rise time grid pulse into a 50 ohm load at up to 4.5 kHz repetition rate and has demonstrated approximately 10,000 hours MTBF. Since the thyratron is used with a magnetic compression circuit having a delay time of 1.4 ms this grid driver incorporates a jitter compensation circuit to adjust the trigger timing of the thyratron to provide overall modulator/laser jitter of less than {plus minus} 2 ns. The specific grid driver requirements will be discussed followed by a description of the circuit design and theory of operation. Construction comments will be followed by performance data (for a specific thyratron and magnetic compression circuit), including pulse shape, jitter, and lifetime. 1 ref., 10 figs.

  4. Reliable, high repetition rate thyratron grid driver used with a magnetic modulator

    NASA Astrophysics Data System (ADS)

    Hill, J. V.; Ball, D. G.; Garrett, D. N.

    1991-06-01

    The Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory uses a magnetic modulator switched by a high voltage thyratron to drive a gas discharge laser. The thyratron trigger source must provide an extremely reliable, low jitter, high-rep-rate grid pulse. This paper describes a thyratron grid driver which delivers a 1.2 kV, 80 ns rise time grid pulse into a 50 ohm load at up to 4.5 kHz repetition rate and has demonstrated approximately 10,000 hours MTBF. Since the thyratron is used with a magnetic compression circuit having a delay time of 1.4 ms, this grid driver incorporates a jitter compensation circuit to adjust the trigger timing of the thyratron to provide overall modulator/laser jitter of less than +/- 2 ns. The specific grid driver requirements will be discussed followed by a description of the circuit design and theory of operation. Construction comments will be followed by performance data (for a specific thyratron and magnetic compression circuit), including pulse shape, jitter, and lifetime.

  5. Increasing the information rates of optical communications via coded modulation: a study of transceiver performance

    PubMed Central

    Maher, Robert; Alvarado, Alex; Lavery, Domaniç; Bayvel, Polina

    2016-01-01

    Optical fibre underpins the global communications infrastructure and has experienced an astonishing evolution over the past four decades, with current commercial systems transmitting data rates in excess of 10 Tb/s over a single fibre core. The continuation of this dramatic growth in throughput has become constrained due to a power dependent nonlinear distortion arising from a phenomenon known as the Kerr effect. The mitigation of fibre nonlinearities is an area of intense research. However, even in the absence of nonlinear distortion, the practical limit on the transmission throughput of a single fibre core is dominated by the finite signal-to-noise ratio (SNR) afforded by current state-of-the-art coherent optical transceivers. Therefore, the key to maximising the number of information bits that can be reliably transmitted over a fibre channel hinges on the simultaneous optimisation of the modulation format and code rate, based on the SNR achieved at the receiver. In this work, we use an information theoretic approach based on the mutual information and the generalised mutual information to characterise a state-of-the-art dual polarisation m-ary quadrature amplitude modulation transceiver and subsequently apply this methodology to a 15-carrier super-channel to achieve the highest throughput (1.125 Tb/s) ever recorded using a single coherent receiver. PMID:26864633

  6. The cellular growth rate controls overall mRNA turnover, and modulates either transcription or degradation rates of particular gene regulons

    PubMed Central

    García-Martínez, José; Delgado-Ramos, Lidia; Ayala, Guillermo; Pelechano, Vicent; Medina, Daniel A.; Carrasco, Fany; González, Ramón; Andrés-León, Eduardo; Steinmetz, Lars; Warringer, Jonas; Chávez, Sebastián; Pérez-Ortín, José E.

    2016-01-01

    We analyzed 80 different genomic experiments, and found a positive correlation between both RNA polymerase II transcription and mRNA degradation with growth rates in yeast. Thus, in spite of the marked variation in mRNA turnover, the total mRNA concentration remained approximately constant. Some genes, however, regulated their mRNA concentration by uncoupling mRNA stability from the transcription rate. Ribosome-related genes modulated their transcription rates to increase mRNA levels under fast growth. In contrast, mitochondria-related and stress-induced genes lowered mRNA levels by reducing mRNA stability or the transcription rate, respectively. We also detected these regulations within the heterogeneity of a wild-type cell population growing in optimal conditions. The transcriptomic analysis of sorted microcolonies confirmed that the growth rate dictates alternative expression programs by modulating transcription and mRNA decay. The regulation of overall mRNA turnover keeps a constant ratio between mRNA decay and the dilution of [mRNA] caused by cellular growth. This regulation minimizes the indiscriminate transmission of mRNAs from mother to daughter cells, and favors the response capacity of the latter to physiological signals and environmental changes. We also conclude that, by uncoupling mRNA synthesis from decay, cells control the mRNA abundance of those gene regulons that characterize fast and slow growth. PMID:26717982

  7. The cellular growth rate controls overall mRNA turnover, and modulates either transcription or degradation rates of particular gene regulons.

    PubMed

    García-Martínez, José; Delgado-Ramos, Lidia; Ayala, Guillermo; Pelechano, Vicent; Medina, Daniel A; Carrasco, Fany; González, Ramón; Andrés-León, Eduardo; Steinmetz, Lars; Warringer, Jonas; Chávez, Sebastián; Pérez-Ortín, José E

    2016-05-01

    We analyzed 80 different genomic experiments, and found a positive correlation between both RNA polymerase II transcription and mRNA degradation with growth rates in yeast. Thus, in spite of the marked variation in mRNA turnover, the total mRNA concentration remained approximately constant. Some genes, however, regulated their mRNA concentration by uncoupling mRNA stability from the transcription rate. Ribosome-related genes modulated their transcription rates to increase mRNA levels under fast growth. In contrast, mitochondria-related and stress-induced genes lowered mRNA levels by reducing mRNA stability or the transcription rate, respectively. We also detected these regulations within the heterogeneity of a wild-type cell population growing in optimal conditions. The transcriptomic analysis of sorted microcolonies confirmed that the growth rate dictates alternative expression programs by modulating transcription and mRNA decay.The regulation of overall mRNA turnover keeps a constant ratio between mRNA decay and the dilution of [mRNA] caused by cellular growth. This regulation minimizes the indiscriminate transmission of mRNAs from mother to daughter cells, and favors the response capacity of the latter to physiological signals and environmental changes. We also conclude that, by uncoupling mRNA synthesis from decay, cells control the mRNA abundance of those gene regulons that characterize fast and slow growth. PMID:26717982

  8. Modulation of heart rate by temporally patterned vagus nerve stimulation in the anesthetized dog.

    PubMed

    Yoo, Paul B; Liu, Haoran; Hincapie, Juan G; Ruble, Stephen B; Hamann, Jason J; Grill, Warren M

    2016-02-01

    Despite current knowledge of the myriad physiological effects of vagus nerve stimulation (VNS) in various mammalian species (including humans), the impact of varying stimulation parameters on nerve recruitment and physiological responses is not well understood. We investigated nerve recruitment, cardiovascular responses, and skeletal muscle responses to different temporal patterns of VNS across 39 combinations of stimulation amplitude, frequency, and number of pulses per burst. Anesthetized dogs were implanted with stimulating and recording cuff electrodes around the cervical vagus nerve, whereas laryngeal electromyogram (EMG) and heart rate were recorded. In seven of eight dogs, VNS-evoked bradycardia (defined as ≥10% decrease in heart rate) was achieved by applying stimuli at amplitudes equal to or greater than the threshold for activating slow B-fibers. Temporally patterned VNS (minimum 5 pulses per burst) was sufficient to elicit bradycardia while reducing the concomitant activation of laryngeal muscles by more than 50%. Temporal patterns of VNS can be used to modulate heart rate while minimizing laryngeal motor fiber activation, and this is a novel approach to reduce the side effects produced by VNS. PMID:26811057

  9. Polarization-modulated second harmonic generation ellipsometric microscopy at video rate.

    PubMed

    DeWalt, Emma L; Sullivan, Shane Z; Schmitt, Paul D; Muir, Ryan D; Simpson, Garth J

    2014-08-19

    Fast 8 MHz polarization modulation coupled with analytical modeling, fast beam-scanning, and synchronous digitization (SD) have enabled simultaneous nonlinear optical Stokes ellipsometry (NOSE) and polarized laser transmittance imaging with image acquisition rates up to video rate. In contrast to polarimetry, in which the polarization state of the exiting beam is recorded, NOSE enables recovery of the complex-valued Jones tensor of the sample that describes all polarization-dependent observables of the measurement. Every video-rate scan produces a set of 30 images (10 for each detector with three detectors operating in parallel), each of which corresponds to a different polarization-dependent result. Linear fitting of this image set contracts it down to a set of five parameters for each detector in second harmonic generation (SHG) and three parameters for the transmittance of the incident beam. These parameters can in turn be used to recover the Jones tensor elements of the sample. Following validation of the approach using z-cut quartz, NOSE microscopy was performed for microcrystals of both naproxen and glucose isomerase. When weighted by the measurement time, NOSE microscopy was found to provide a substantial (>7 decades) improvement in the signal-to-noise ratio relative to our previous measurements based on the rotation of optical elements and a 3-fold improvement relative to previous single-point NOSE approaches. PMID:25050448

  10. Structural modulation of silicon nanowires by combining a high gas flow rate with metal catalysts

    NASA Astrophysics Data System (ADS)

    Seo, Dongjea; Lee, Jaejun; Kim, Sung Wook; Kim, Ilsoo; Na, Jukwan; Hong, Min-Ho; Choi, Heon-Jin

    2015-04-01

    We grew silicon nanowires (SiNWs) by a vapor-liquid-solid (VLS) mechanism using metal catalysts of gold (Au), titanium (Ti), manganese (Mn), and iron (Fe) under a high flow rate of hydrogen (H2). This combination of catalyst types and high gas flow rate revealed the potential for growing various SiNWs, including kinked SiNWs (with Au), ultra-thin SiNWs having diameters about 5 nm (with Ti), rough-surfaced SiNWs (with Mn), and ribbon-shaped SiNWs tens of microns in width (with Fe). The high flow rate of gas affects the VLS mechanism differently for each combination; for example, it induces an unstable solid-liquid interfaces (with Au), active etching of the catalyst (with Ti), sidewall deposition by a vapor-solid (VS) mechanism, and an asymmetric precipitation of Si in the catalyst (with Fe). Our combinatorial approach may provide a new path for the structural modulation of SiNWs via the VLS mechanism.

  11. Rate modulated pacing based on right ventricular dP/dt: quantitative analysis of chronotropic response.

    PubMed

    Kay, G N; Philippon, F; Bubien, R S; Plumb, V J

    1994-08-01

    Right ventricular contractility increases in response to catecholamine stimulation and greater ventricular preload, factors that increase with exercise workload. Thus, the maximum systolic dP/dt may be a potentially useful sensor to control the pacing rate of a permanent pacing system. The present study was designed to test the long-term performance of a permanent pacemaker that modulates pacing rate based on right ventricular dP/dt and to quantitatively analyze the chronotropic response characteristics of this sensor in a group of patients with widely varying structural heart diseases and degrees of hemodynamic impairment. A permanent pacing system incorporating a high fidelity pressure sensor in the lead for measurement of right ventricular dP/dt was implanted in 13 patients with atrial arrhythmias and AV block, including individuals with coronary artery disease, hypertension, severe obstructive pulmonary disease with prior pneumonectomy, atrial septal defect, dilated cardiomyopathy, restrictive cardiomyopathy, and mitral stenosis. Patients underwent paired treadmill exercise testing in the VVI and VVIR pacing modes with measurement of expired gas exchange and quantitative analysis of chronotropic response using the concept of metabolic reserve. The peak right ventricular dP/dt ranged from 238-891 mmHg/sec with a pulse pressure that ranged from 19-41 mmHg. There was a positive correlation between the right ventricular dP/dt and pulse pressure (r = 0.70, P = 0.012). The maximum pacing rate and VO2max were 72 +/- 6 beats/min and 12.61 +/- 4.0 cc O2/kg per minute during VVI pacing and increased to 124 +/- 18 beats/min and 15.89 +/- 5.9 cc O2/kg per minute in the VVIR pacing mode (P < 0.0003 and P < 0.002, respectively). The integrated area under the normalized rate response curve was 96.7 +/- 45.7% of expected during exercise and 100.1 +/- 43.4% of expected during recovery. One patient demonstrated an anomalous increase in pacing rate in response to a change in

  12. Theta, beta and gamma rate modulations in the developing auditory system.

    PubMed

    Vanvooren, Sophie; Hofmann, Michael; Poelmans, Hanne; Ghesquière, Pol; Wouters, Jan

    2015-09-01

    In the brain, the temporal analysis of many important auditory features relies on the synchronized firing of neurons to the auditory input rhythm. These so-called neural oscillations play a crucial role in sensory and cognitive processing and deviances in oscillatory activity have shown to be associated with neurodevelopmental disorders. Given the importance of neural auditory oscillations in normal and impaired sensory and cognitive functioning, there has been growing interest in their developmental trajectory from early childhood on. In the present study, neural auditory processing was investigated in typically developing young children (n = 40) and adults (n = 27). In all participants, auditory evoked theta, beta and gamma responses were recorded. The results of this study show maturational differences between children and adults in neural auditory processing at cortical as well as at brainstem level. Neural background noise at cortical level was shown to be higher in children compared to adults. In addition, higher theta response amplitudes were measured in children compared to adults. For beta and gamma rate modulations, different processing asymmetry patterns were observed between both age groups. The mean response phase was also shown to differ significantly between children and adults for all rates. Results suggest that cortical auditory processing of beta develops from a general processing pattern into a more specialized asymmetric processing preference over age. Moreover, the results indicate an enhancement of bilateral representation of monaural sound input at brainstem with age. A dissimilar efficiency of auditory signal transmission from brainstem to cortex along the auditory pathway between children and adults is suggested. These developmental differences might be due to both functional experience-dependent as well as anatomical changes. The findings of the present study offer important information about maturational differences between children

  13. Study of the optimal duty cycle and pumping rate for square-wave amplitude-modulated Bell–Bloom magnetometers

    NASA Astrophysics Data System (ADS)

    Mei-Ling, Wang; Meng-Bing, Wang; Gui-Ying, Zhang; Kai-Feng, Zhao

    2016-06-01

    We theoretically and experimentally study the optimal duty cycle and pumping rate for square-wave amplitude-modulated Bell–Bloom magnetometers. The theoretical and the experimental results are in good agreement for duty cycles and corresponding pumping rates ranging over 2 orders of magnitude. Our study gives the maximum field response as a function of duty cycle and pumping rate. Especially, for a fixed duty cycle, the maximum field response is obtained when the time averaged pumping rate, which is the product of pumping rate and duty cycle, is equal to the transverse relaxation rate in the dark. By using a combination of small duty cycle and large pumping rate, one can increase the maximum field response by up to a factor of 2 or π/2, relative to that of the sinusoidal modulation or the 50% duty cycle square-wave modulation respectively. We further show that the same pumping condition is also practically optimal for the sensitivity due to the fact that the signal at resonance is insensitive to the fluctuations of pumping rate and duty cycle. Project supported by the National Natural Science Foundation of China (Grant No. 11074050).

  14. Application of a binary polymer system in drug release rate modulation. 1. Characterization of release mechanism.

    PubMed

    Kim, H; Fassihi, R

    1997-03-01

    A new binary polymer matrix tablet for oral administration was developed. The system will deliver drug at variable rates according to zero-order kinetics for total drug content and is manufactured by direct compression technology. Highly methoxylated pectin and hydroxypropyl methylcellulose (HPMC) at different ratios were used as major formulation components, and prednisolone was used as the drug model. The results indicate that by increasing pectin:HPMC ratios, release rates are increased, but zero-order kinetics prevail throughout the dissolution period (e.g., 3-22 h). Different pectin:HPMC ratios provide a range of viscosities that modulates drug release and results in rapid hydration/gelation in both axial and radial directions, as evidenced by photomicrographic pictures. This hydration-gelation contributes to the development of swelling/erosion boundaries and consequently to constant drug release. Combination of these particular polymers facilitates rapid formation of necessary boundaries (i.e., gel layer and solid core boundaries) to control overall mass transfer processes. The drug fraction released (Mt/M infinity), release kinetics, and mechanism of release were analyzed by applying the simple power law expression Mt/M infinity = kt(n), where k is a kinetic constant and the exponent n is indicative of the release mechanism. The calculated n values for pectin:HPMC ratios of 4:5, 3:6, and 2:7 were >0.95, which is indicative of a Case II transport mechanism (polymer relaxation/dissolution). The achievement of total zero-order kinetics is due to the predictable swelling/erosion and final polymer chain deaggregation and dissolution that is regulated by the gelling characteristics of polymers in the formulation. PMID:9050799

  15. PGR5-PGRL1-Dependent Cyclic Electron Transport Modulates Linear Electron Transport Rate in Arabidopsis thaliana.

    PubMed

    Suorsa, Marjaana; Rossi, Fabio; Tadini, Luca; Labs, Mathias; Colombo, Monica; Jahns, Peter; Kater, Martin M; Leister, Dario; Finazzi, Giovanni; Aro, Eva-Mari; Barbato, Roberto; Pesaresi, Paolo

    2016-02-01

    Plants need tight regulation of photosynthetic electron transport for survival and growth under environmental and metabolic conditions. For this purpose, the linear electron transport (LET) pathway is supplemented by a number of alternative electron transfer pathways and valves. In Arabidopsis, cyclic electron transport (CET) around photosystem I (PSI), which recycles electrons from ferrodoxin to plastoquinone, is the most investigated alternative route. However, the interdependence of LET and CET and the relative importance of CET remain unclear, largely due to the difficulties in precise assessment of the contribution of CET in the presence of LET, which dominates electron flow under physiological conditions. We therefore generated Arabidopsis mutants with a minimal water-splitting activity, and thus a low rate of LET, by combining knockout mutations in PsbO1, PsbP2, PsbQ1, PsbQ2, and PsbR loci. The resulting Δ5 mutant is viable, although mature leaves contain only ∼ 20% of wild-type naturally less abundant PsbO2 protein. Δ5 plants compensate for the reduction in LET by increasing the rate of CET, and inducing a strong non-photochemical quenching (NPQ) response during dark-to-light transitions. To identify the molecular origin of such a high-capacity CET, we constructed three sextuple mutants lacking the qE component of NPQ (Δ5 npq4-1), NDH-mediated CET (Δ5 crr4-3), or PGR5-PGRL1-mediated CET (Δ5 pgr5). Their analysis revealed that PGR5-PGRL1-mediated CET plays a major role in ΔpH formation and induction of NPQ in C3 plants. Moreover, while pgr5 dies at the seedling stage under fluctuating light conditions, Δ5 pgr5 plants are able to survive, which underlines the importance of PGR5 in modulating the intersystem electron transfer. PMID:26687812

  16. Origin of Heart Rate Variability and Turbulence: An Appraisal of Autonomic Modulation of Cardiovascular Function

    PubMed Central

    Lombardi, Federico; Stein, Phyllis K.

    2011-01-01

    Heart period constantly changes on a beat to beat basis, due to autonomic influences on the sinoatrial node, and changes can be quantified as heart rate variability (HRV). In addition, after a premature ventricular beat, there are reproducible variations in RR interval, also due to baroreflex mediated autonomic influences on the sinoatrial node, that can be measured as heart rate turbulence (HRT). Impaired autonomic function as measured by HRV and HRT has proven to predict adverse outcomes in clinical settings. The ability of reduced HRV and HRT to predict adverse outcomes has been explained by their dependency on vagal mechanisms that could reflect an increased sympathetic and a reduced vagal modulation of sinus node, thus favoring cardiac electrical instability. Analysis of non-linear dynamics of HRV has also been utilized to describe the fractal like characteristic of the variability signal and proven effective in identify patients at risk for sudden cardiac death. Despite the clinical validity of these measures, it has also been evident that the relationship between neural input and sinus node responsiveness is extremely complex and variable in different clinical conditions. Thus, abnormal HRV or HRT on a clinical Holter recordings may reflect non-neural as well as autonomic mechanisms, and this also needs to be taken into account when interpreting any findings. However, under controlled conditions, the computation of the low and high frequency components of HRV and of their normalized powers or ratio seems capable of providing valid information on sympatho-vagal balance in normal subjects, as well as in most patients with a preserved left ventricular function. Thus, analysis of HRV does provide a unique tool to specifically assess autonomic control mechanisms in association with various perturbations. In conclusion, HRV measures are of substantial utility to identify patients with an increased cardiac mortality and to evaluate autonomic control mechanisms, but

  17. Origin of heart rate variability and turbulence: an appraisal of autonomic modulation of cardiovascular function.

    PubMed

    Lombardi, Federico; Stein, Phyllis K

    2011-01-01

    Heart period constantly changes on a beat to beat basis, due to autonomic influences on the sinoatrial node, and changes can be quantified as heart rate variability (HRV). In addition, after a premature ventricular beat, there are reproducible variations in RR interval, also due to baroreflex mediated autonomic influences on the sinoatrial node, that can be measured as heart rate turbulence (HRT). Impaired autonomic function as measured by HRV and HRT has proven to predict adverse outcomes in clinical settings. The ability of reduced HRV and HRT to predict adverse outcomes has been explained by their dependency on vagal mechanisms that could reflect an increased sympathetic and a reduced vagal modulation of sinus node, thus favoring cardiac electrical instability. Analysis of non-linear dynamics of HRV has also been utilized to describe the fractal like characteristic of the variability signal and proven effective in identify patients at risk for sudden cardiac death. Despite the clinical validity of these measures, it has also been evident that the relationship between neural input and sinus node responsiveness is extremely complex and variable in different clinical conditions. Thus, abnormal HRV or HRT on a clinical Holter recordings may reflect non-neural as well as autonomic mechanisms, and this also needs to be taken into account when interpreting any findings. However, under controlled conditions, the computation of the low and high frequency components of HRV and of their normalized powers or ratio seems capable of providing valid information on sympatho-vagal balance in normal subjects, as well as in most patients with a preserved left ventricular function. Thus, analysis of HRV does provide a unique tool to specifically assess autonomic control mechanisms in association with various perturbations. In conclusion, HRV measures are of substantial utility to identify patients with an increased cardiac mortality and to evaluate autonomic control mechanisms, but

  18. Heart Rate and Extracellular Sodium and Potassium Modulation of Gap Junction Mediated Conduction in Guinea Pigs

    PubMed Central

    Entz, Michael; George, Sharon A.; Zeitz, Michael J.; Raisch, Tristan; Smyth, James W.; Poelzing, Steven

    2016-01-01

    Background: Recent studies suggested that cardiac conduction in murine hearts with narrow perinexi and 50% reduced connexin43 (Cx43) expression is more sensitive to relatively physiological changes of extracellular potassium ([K+]o) and sodium ([Na+]o). Purpose: Determine whether similar [K+]o and [Na+]o changes alter conduction velocity (CV) sensitivity to pharmacologic gap junction (GJ) uncoupling in guinea pigs. Methods: [K+]o and [Na+]o were varied in Langendorff perfused guinea pig ventricles (Solution A: [K+]o = 4.56 and [Na+]o = 153.3 mM. Solution B: [K+]o = 6.95 and [Na+]o = 145.5 mM). Gap junctions were inhibited with carbenoxolone (CBX) (15 and 30 μM). Epicardial CV was quantified by optical mapping. Perinexal width was measured with transmission electron microscopy. Total and phosphorylated Cx43 were evaluated by western blotting. Results: Solution composition did not alter CV under control conditions or with 15μM CBX. Decreasing the basic cycle length (BCL) of pacing from 300 to 160 ms decreased CV uniformly with both solutions. At 30 μM CBX, a change in solution did not alter CV either longitudinally or transversely at BCL = 300 ms. However, reducing BCL to 160 ms caused CV to decrease more in hearts perfused with Solution B than A. Solution composition did not alter perinexal width, nor did it change total or phosphorylated serine 368 Cx43 expression. These data suggest that the solution dependent CV changes were independent of altered perinexal width or GJ coupling. Action potential duration was always shorter in hearts perfused with Solution B than A, independent of pacing rate and/or CBX concentration. Conclusions: Increased heart rate and GJ uncoupling can unmask small CV differences caused by changing [K+]o and [Na+]o. These data suggest that modulating extracellular ionic composition may be a novel anti-arrhythmic target in diseases with abnormal GJ coupling, particularly when heart rate cannot be controlled. PMID:26869934

  19. Chaos-induced modulation of reliability boosts output firing rate in downstream cortical areas

    NASA Astrophysics Data System (ADS)

    Tiesinga, P. H.

    2004-03-01

    The reproducibility of neural spike train responses to an identical stimulus across different presentations (trials) has been studied extensively. Reliability, the degree of reproducibility of spike trains, was found to depend in part on the amplitude and frequency content of the stimulus [J. Hunter and J. Milton, J. Neurophysiol. 90, 387 (2003)]. The responses across different trials can sometimes be interpreted as the response of an ensemble of similar neurons to a single stimulus presentation. How does the reliability of the activity of neural ensembles affect information transmission between different cortical areas? We studied a model neural system consisting of two ensembles of neurons with Hodgkin-Huxley-type channels. The first ensemble was driven by an injected sinusoidal current that oscillated in the gamma-frequency range (40 Hz) and its output spike trains in turn drove the second ensemble by fast excitatory synaptic potentials with short term depression. We determined the relationship between the reliability of the first ensemble and the response of the second ensemble. In our paradigm the neurons in the first ensemble were initially in a chaotic state with unreliable and imprecise spike trains. The neurons became entrained to the oscillation and responded reliably when the stimulus power was increased by less than 10%. The firing rate of the first ensemble increased by 30%, whereas that of the second ensemble could increase by an order of magnitude. We also determined the response of the second ensemble when its input spike trains, which had non-Poisson statistics, were replaced by an equivalent ensemble of Poisson spike trains. The resulting output spike trains were significantly different from the original response, as assessed by the metric introduced by Victor and Purpura [J. Neurophysiol. 76, 1310 (1996)]. These results are a proof of principle that weak temporal modulations in the power of gamma-frequency oscillations in a given cortical area

  20. The role of α7 nicotinic acetylcholine receptor in modulation of heart rate dynamics in endotoxemic rats.

    PubMed

    Mazloom, Roham; Eftekhari, Golnar; Rahimi-Balaei, Maryam; Rahimi, Maryam; Khori, Vahid; Hajizadeh, Sohrab; Dehpour, Ahmad R; Mani, Ali R

    2013-01-01

    Previous reports have indicated that artificial stimulation of the vagus nerve reduces systemic inflammation in experimental models of sepsis. This phenomenon is a part of a broader cholinergic anti-inflammatory pathway which activates the vagus nerve to modulate inflammation through activation of alpha7 nicotinic acetylcholine receptors (α7nACHR). Heart rate variability represents the complex interplay between autonomic nervous system and cardiac pacemaker cells. Reduced heart rate variability and increased cardiac cycle regularity is a hallmark of clinical conditions that are associated with systemic inflammation (e.g. endotoxemia and sepsis). The present study was aimed to assess the role of α7nACHR in modulation of heart rate dynamics during systemic inflammation. Systemic inflammation was induced by injection of endotoxin (lipopolysaccharide) in rats. Electrocardiogram and body temperature were recorded in conscious animals using a telemetric system. Linear and non-linear indices of heart rate variability (e.g. sample entropy and fractal-like temporal structure) were assessed. RT-PCR and immunohistochemistry studies showed that α7nACHR is expressed in rat atrium and is mainly localized at the endothelial layer. Systemic administration of an α7nACHR antagonist (methyllycaconitine) did not show a significant effect on body temperature or heart rate dynamics in naïve rats. However, α7nACHR blockade could further reduce heart rate variability and elicit a febrile response in endotoxemic rats. Pre-treatment of endotoxemic animals with an α7nACHR agonist (PHA-543613) was unable to modulate heart rate dynamics in endotoxemic rats but could prevent the effect of endotoxin on body temperature within 24 h experiment. Neither methyllycaconitine nor PHA-543613 could affect cardiac beating variability of isolated perfused hearts taken from control or endotoxemic rats. Based on our observations we suggest a tonic role for nicotinic acetylcholine receptors in

  1. Modulation of post-movement beta rebound by contraction force and rate of force development.

    PubMed

    Fry, Adam; Mullinger, Karen J; O'Neill, George C; Barratt, Eleanor L; Morris, Peter G; Bauer, Markus; Folland, Jonathan P; Brookes, Matthew J

    2016-07-01

    Movement induced modulation of the beta rhythm is one of the most robust neural oscillatory phenomena in the brain. In the preparation and execution phases of movement, a loss in beta amplitude is observed [movement related beta decrease (MRBD)]. This is followed by a rebound above baseline on movement cessation [post movement beta rebound (PMBR)]. These effects have been measured widely, and recent work suggests that they may have significant importance. Specifically, they have potential to form the basis of biomarkers for disease, and have been used in neuroscience applications ranging from brain computer interfaces to markers of neural plasticity. However, despite the robust nature of both MRBD and PMBR, the phenomena themselves are poorly understood. In this study, we characterise MRBD and PMBR during a carefully controlled isometric wrist flexion paradigm, isolating two fundamental movement parameters; force output, and the rate of force development (RFD). Our results show that neither altered force output nor RFD has a significant effect on MRBD. In contrast, PMBR was altered by both parameters. Higher force output results in greater PMBR amplitude, and greater RFD results in a PMBR which is higher in amplitude and shorter in duration. These findings demonstrate that careful control of movement parameters can systematically change PMBR. Further, for temporally protracted movements, the PMBR can be over 7 s in duration. This means accurate control of movement and judicious selection of paradigm parameters are critical in future clinical and basic neuroscientific studies of sensorimotor beta oscillations. Hum Brain Mapp 37:2493-2511, 2016. © 2016 Wiley Periodicals, Inc. PMID:27061243

  2. Modulation of post‐movement beta rebound by contraction force and rate of force development

    PubMed Central

    Fry, Adam; Mullinger, Karen J.; O'Neill, George C.; Barratt, Eleanor L.; Morris, Peter G.; Bauer, Markus; Folland, Jonathan P.

    2016-01-01

    Abstract Movement induced modulation of the beta rhythm is one of the most robust neural oscillatory phenomena in the brain. In the preparation and execution phases of movement, a loss in beta amplitude is observed [movement related beta decrease (MRBD)]. This is followed by a rebound above baseline on movement cessation [post movement beta rebound (PMBR)]. These effects have been measured widely, and recent work suggests that they may have significant importance. Specifically, they have potential to form the basis of biomarkers for disease, and have been used in neuroscience applications ranging from brain computer interfaces to markers of neural plasticity. However, despite the robust nature of both MRBD and PMBR, the phenomena themselves are poorly understood. In this study, we characterise MRBD and PMBR during a carefully controlled isometric wrist flexion paradigm, isolating two fundamental movement parameters; force output, and the rate of force development (RFD). Our results show that neither altered force output nor RFD has a significant effect on MRBD. In contrast, PMBR was altered by both parameters. Higher force output results in greater PMBR amplitude, and greater RFD results in a PMBR which is higher in amplitude and shorter in duration. These findings demonstrate that careful control of movement parameters can systematically change PMBR. Further, for temporally protracted movements, the PMBR can be over 7 s in duration. This means accurate control of movement and judicious selection of paradigm parameters are critical in future clinical and basic neuroscientific studies of sensorimotor beta oscillations. Hum Brain Mapp 37:2493–2511, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc PMID:27061243

  3. Target Selection Signals Influence Perceptual Decisions by Modulating the Onset and Rate of Evidence Accumulation.

    PubMed

    Loughnane, Gerard M; Newman, Daniel P; Bellgrove, Mark A; Lalor, Edmund C; Kelly, Simon P; O'Connell, Redmond G

    2016-02-22

    Computational and neurophysiological research has highlighted neural processes that accumulate sensory evidence for perceptual decisions [1]. These processes have been studied in the context of highly simplified perceptual discrimination paradigms in which the physical evidence appears at times and locations that are either entirely predictable or exogenously cued (e.g., by the onset of the stimulus itself). Yet, we are rarely afforded such certainty in everyday life. For example, when driving along a busy motorway, we must continually monitor the movements of surrounding vehicles for events that call for a lane change. In such scenarios, it is unknown which of the continuously present information sources will become relevant or when. Although it is well established that evidence integration provides an effective mechanism for countering the impact of noise [2], the question of how this mechanism is implemented in the face of uncertain evidence onsets has yet to be answered. Here, we show that when monitoring two potential sources of information for evidence occurring unpredictably in both time and space, the human brain employs discrete, early target selection signals that significantly modulate the onset and rate of neural evidence accumulation, and thereby the timing and accuracy of perceptual reports. These selection signals share many of the key characteristics of the N2pc component highlighted in the literature on visual search [3, 4] yet are present even in the absence of distractors and under situations of low temporal and spatial uncertainty. These data provide novel insights into how target selection supports decision making in uncertain environments. PMID:26853360

  4. Ability of primary auditory cortical neurons to detect amplitude modulation with rate and temporal codes: neurometric analysis

    PubMed Central

    Johnson, Jeffrey S.; Yin, Pingbo; O'Connor, Kevin N.

    2012-01-01

    Amplitude modulation (AM) is a common feature of natural sounds, and its detection is biologically important. Even though most sounds are not fully modulated, the majority of physiological studies have focused on fully modulated (100% modulation depth) sounds. We presented AM noise at a range of modulation depths to awake macaque monkeys while recording from neurons in primary auditory cortex (A1). The ability of neurons to detect partial AM with rate and temporal codes was assessed with signal detection methods. On average, single-cell synchrony was as or more sensitive than spike count in modulation detection. Cells are less sensitive to modulation depth if tested away from their best modulation frequency, particularly for temporal measures. Mean neural modulation detection thresholds in A1 are not as sensitive as behavioral thresholds, but with phase locking the most sensitive neurons are more sensitive, suggesting that for temporal measures the lower-envelope principle cannot account for thresholds. Three methods of preanalysis pooling of spike trains (multiunit, similar to convergence from a cortical column; within cell, similar to convergence of cells with matched response properties; across cell, similar to indiscriminate convergence of cells) all result in an increase in neural sensitivity to modulation depth for both temporal and rate codes. For the across-cell method, pooling of a few dozen cells can result in detection thresholds that approximate those of the behaving animal. With synchrony measures, indiscriminate pooling results in sensitive detection of modulation frequencies between 20 and 60 Hz, suggesting that differences in AM response phase are minor in A1. PMID:22422997

  5. Divergent microtubule assembly rates after short- versus long-term loss of end-modulating kinesins

    PubMed Central

    Wordeman, Linda; Decarreau, Justin; Vicente, Juan Jesus; Wagenbach, Michael

    2016-01-01

    Depletion of microtubule (MT) regulators can initiate stable alterations in MT assembly rates that affect chromosome instability and mitotic spindle function, but the manner by which cellular MT assembly rates can stably increase or decrease is not understood. To investigate this phenomenon, we measured the response of microtubule assembly to both rapid and long-term loss of MT regulators MCAK/Kif2C and Kif18A. Depletion of MCAK/Kif2C by siRNA stably decreases MT assembly rates in mitotic spindles, whereas depletion of Kif18A stably increases rates of assembly. Surprisingly, this is not phenocopied by rapid rapamycin-dependent relocalization of MCAK/Kif2C and Kif18A to the plasma membrane. Instead, this treatment yields opposite affects on MT assembly. Rapidly increased MT assembly rates are balanced by a decrease in nucleated microtubules, whereas nucleation appears to be maximal and limiting for decreased MT assembly rates and also for long-term treatments. We measured amplified tubulin synthesis during long-term depletion of MT regulators and hypothesize that this is the basis for different phenotypes arising from long-term versus rapid depletion of MT regulators. PMID:26912793

  6. A compact 7-cell Si-drift detector module for high-count rate X-ray spectroscopy

    PubMed Central

    Hansen, K.; Reckleben, C.; Diehl, I.; Klär, H.

    2015-01-01

    A new Si-drift detector module for fast X-ray spectroscopy experiments was developed and realized. The Peltier-cooled module comprises a sensor with 7 × 7-mm2 active area, an integrated circuit for amplification, shaping and detection, storage, and derandomized readout of signal pulses in parallel, and amplifiers for line driving. The compactness and hexagonal shape of the module with a wrench size of 16mm allow very short distances to the specimen and multi-module arrangements. The power dissipation is 186mW. At a shaper peaking time of 190 ns and an integration time of 450 ns an electronic rms noise of ~11 electrons was achieved. When operated at 7 °C, FWHM line widths around 260 and 460 eV (Cu-Kα) were obtained at low rates and at sum-count rates of 1.7 MHz, respectively. The peak shift is below 1% for a broad range of count rates. At 1.7-MHz sum-count rate the throughput loss amounts to 30%. PMID:26366028

  7. Reinforcement Magnitude Modulates the Rate-Dependent Effects of Fluvoxamine and Desipramine on Fixed-Interval Responding in the Pigeon

    PubMed Central

    Lamb, R.J.; Ginsburg, Brett C.

    2013-01-01

    Some doses of fluvoxamine can decrease ethanol-maintained behavior more than food-maintained behavior. This might be explained by differences in reinforcement magnitude. In a previous study, fluvoxamine’s effects on Fixed-Ratio responding did not depend upon reinforcement magnitude. However, response rates differed with reinforcement magnitude. These differences in response rate might explain the failure to observe differences in the potency of fluvoxamine with changes in reinforcement magnitude. Methods We examined if the effects of fluvoxamine and desipramine depend on reinforcement magnitude and response rate by administering these drugs to pigeons responding under a multiple Fixed-Interval schedule in which responding in three components was maintained by differing durations of food presentation (2-, 4-, & 8-sec). Results Fluvoxamine and desipramine’s effects depended jointly on control rate, reinforcement magnitude, and dose. Low fluvoxamine doses had rate-dependent effects in all three components, --increasing lower rates more than higher rates; as dose increased these rate-dependent effects became greater for components maintained by 2- or 4-sec of food presentation, while declining in the component maintained by 8-sec. Low desipramine doses had rate-dependent effects only in the component maintained by 2-sec; whereas higher doses had rate-dependent effects in components maintained by 2- or 4-sec. Still higher doses had rate-dependent effects in all three components. Conclusions While the effects of fluvoxamine and desipramine may not depend upon reinforcement magnitude when studied under Fixed-Ratio schedules, reinforcement magnitude can modulate their effects when studied over a wider range of control response rates. PMID:18195594

  8. Utilization of multi-band OFDM modulation to increase traffic rate of phosphor-LED wireless VLC.

    PubMed

    Yeh, Chien-Hung; Chen, Hsing-Yu; Chow, Chi-Wai; Liu, Yen-Liang

    2015-01-26

    To increase the traffic rate in phosphor-LED visible light communication (VLC), a multi-band orthogonal frequency division multiplexed (OFDM) modulation is first proposed and demonstrated. In the measurement, we do not utilize optical blue filter to increase modulation bandwidth of phosphor-LED in the VLC system. In this proposed scheme, different bands of OFDM signals are applied to different LED chips in a LED lamp, this can avoid the power fading and nonlinearity issue by applying the same OFDM signal to all the LED chips in a LED lamp. Here, the maximum increase percentages of traffic rates are 41.1%, 17.8% and 17.8% under received illuminations of 200, 500 and 1000 Lux, respectively, when the proposed three-band OFDM modulation is used in the VLC system. In addition, the analysis and verification by experiments are also performed. PMID:25835873

  9. Direction-Modulated Brachytherapy for High-Dose-Rate Treatment of Cervical Cancer. I: Theoretical Design

    SciTech Connect

    Han, Dae Yup; Webster, Matthew J.; Scanderbeg, Daniel J.; Yashar, Catheryn; Choi, Dongju; Song, Bongyong; Devic, Slobodan; Ravi, Ananth; Song, William Y.

    2014-07-01

    Purpose: To demonstrate that utilization of the direction-modulated brachytherapy (DMBT) concept can significantly improve treatment plan quality in the setting of high-dose-rate (HDR) brachytherapy for cervical cancer. Methods and Materials: The new, MRI-compatible, tandem design has 6 peripheral holes of 1.3-mm diameter, grooved along a nonmagnetic tungsten-alloy rod (ρ = 18.0 g/cm{sup 3}), enclosed in Delrin tubing (polyoxymethylene, ρ = 1.41 g/cm{sup 3}), with a total thickness of 6.4 mm. The Monte Carlo N-Particle code was used to calculate the anisotropic {sup 192}Ir dose distributions. An in-house-developed inverse planning platform, geared with simulated annealing and constrained-gradient optimization algorithms, was used to replan 15 patient cases (total 75 plans) treated with a conventional tandem and ovoids (T and O) applicator. Prescription dose was 6 Gy. For replanning, we replaced the conventional tandem with that of the new DMBT tandem for optimization but left the ovoids in place and kept the dwell positions as originally planned. All DMBT plans were normalized to match the high-risk clinical target volume V100 coverage of the T and O plans. Results: In general there were marked improvements in plan quality for the DMBT plans. On average, D2cc for the bladder, rectum, and sigmoid were reduced by 0.59 ± 0.87 Gy (8.5% ± 28.7%), 0.48 ± 0.55 Gy (21.1% ± 27.2%), and 0.10 ± 0.38 Gy (40.6% ± 214.9%) among the 75 plans, with best single-plan reductions of 3.20 Gy (40.8%), 2.38 Gy (40.07%), and 1.26 Gy (27.5%), respectively. The high-risk clinical target volume D90 was similar, with 6.55 ± 0.96 Gy and 6.59 ± 1.06 Gy for T and O and DMBT, respectively. Conclusions: Application of the DMBT concept to cervical cancer allowed for improved organ at risk sparing while achieving similar target coverage on a sizeable patient population, as intended, by maximally utilizing the anatomic information contained in 3-dimensional

  10. Generation of tunable, high repetition rate frequency combs with equalized spectra using carrier injection based silicon modulators

    NASA Astrophysics Data System (ADS)

    Nagarjun, K. P.; Selvaraja, Shankar Kumar; Supradeepa, V. R.

    2016-03-01

    High repetition-rate frequency combs with tunable repetition rate and carrier frequency are extensively used in areas like Optical communications, Microwave Photonics and Metrology. A common technique for their generation is strong phase modulation of a CW-laser. This is commonly implemented using Lithium-Niobate based modulators. With phase modulation alone, the combs have poor spectral flatness and significant number of missing lines. To overcome this, a complex cascade of multiple intensity and phase modulators are used. A comb generator on Silicon based on these principles is desirable to enable on-chip integration with other functionalities while reducing power consumption and footprint. In this work, we analyse frequency comb generation in carrier injection based Silicon modulators. We observe an interesting effect in these comb generators. Enhanced absorption accompanying carrier injection, an undesirable effect in data modulators, shapes the amplitude here to enable high quality combs from a single modulator. Thus, along with reduced power consumption to generate a specific number of lines, the complexity has also been significantly reduced. We use a drift-diffusion solver and mode solver (Silvaco TCAD) along with Soref-Bennett relations to calculate the variations in refractive indices and absorption of an optimized Silicon PIN - waveguide modulator driven by an unbiased high frequency (10 Ghz) voltage signal. Our simulations demonstrate that with a device length of 1 cm, a driving voltage of 2V and minor shaping with a passive ring-resonator filter, we obtain 37 lines with a flatness better than 5-dB across the band and power consumption an order of magnitude smaller than Lithium-Niobate modulators.

  11. Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

    NASA Technical Reports Server (NTRS)

    Wilson, T. E.; Cui, J.; Crandall, C. G.

    2001-01-01

    1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P < 0.001) during bolus sodium nitroprusside-induced reductions in blood pressure, and significantly reduced (from 92 +/- 4 to 68 +/- 4 beats x min(-1); P < 0.001) during bolus phenylephrine-induced elevations in blood pressure, thereby demonstrating normal baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

  12. Identification of Rhipicephalus microplus Genes That Modulate the Infection Rate of the Rickettsia Anaplasma marginale

    PubMed Central

    Mercado-Curiel, Ricardo F.; Ávila-Ramírez, María L.; Palmer, Guy H.; Brayton, Kelly A.

    2014-01-01

    Arthropod vectors transmit a diversity of animal and human pathogens, ranging from RNA viruses to protozoal parasites. Chemotherapeutic control of pathogens has classically focused either on insecticides that kill the vector itself or antimicrobials for infected patients. The limitation of the former is that it targets both infected and uninfected vectors and selects for resistant populations while the latter requires prompt and accurate diagnosis. An alternative strategy is to target vector molecules that permit the pathogen to establish itself, replicate, and/or develop within the vector. Using the rickettsial pathogen Anaplasma marginale and its tropical tick vector, Rhipicephalus microplus, as a model, we tested whether silencing specific gene targets would affect tick infection rates (the % of fed ticks that are infected with the pathogen) and pathogen levels within infected ticks. Silencing of three R. microplus genes, CK187220, CV437619 and TC18492, significantly decreased the A. marginale infection rate in salivary glands, whereas gene silencing of TC22382, TC17129 and TC16059 significantly increased the infection rate in salivary glands. However in all cases of significant difference in the infection rate, the pathogen levels in the ticks that did become infected, were not significantly different. These results are consistent with the targeted genes affecting the pathogen at early steps in infection of the vector rather than in replication efficiency. Identifying vector genes and subsequent determination of the encoded functions are initial steps in discovery of new targets for inhibiting pathogen development and subsequent transmission. PMID:24608654

  13. Solar-cycle modulation of event rates in the chlorine solar neutrino experiment

    NASA Astrophysics Data System (ADS)

    Bahcall, John N.; Press, William H.

    1991-04-01

    The time dependence of the event rates in the Homestake chlorine solar neutrino experiment are reexamined using new Ar-37 production data covering the period from late 1986 to mid-1989. The data span almost two complete solar cycles. A careful statistical analysis using nonparametric rank-order statistics is used to calculate quantitative significance levels that do not depend on experimental errors. The results show that the Ar-37 production rate in the experiment is anticorrelated with solar activity for approximately 1977-1989. The shape of the Ar-37 production rate is different from the inverted sunspot activity curve. The Ar-37 production rate is better descrbed by a skewed sawtooth function than by the sunspot number. The best-fitting sawtooth function with sunspot period has a slow rise and a rapid decline. The Ar-37 maximum occurs about 12.5 yr after the solar sunspot minimum, while minimum Ar-37 production is more nearly simultaneous with the sunspot maximum.

  14. A dual-input nonlinear system analysis of autonomic modulation of heart rate

    NASA Technical Reports Server (NTRS)

    Chon, K. H.; Mullen, T. J.; Cohen, R. J.

    1996-01-01

    Linear analyses of fluctuations in heart rate and other hemodynamic variables have been used to elucidate cardiovascular regulatory mechanisms. The role of nonlinear contributions to fluctuations in hemodynamic variables has not been fully explored. This paper presents a nonlinear system analysis of the effect of fluctuations in instantaneous lung volume (ILV) and arterial blood pressure (ABP) on heart rate (HR) fluctuations. To successfully employ a nonlinear analysis based on the Laguerre expansion technique (LET), we introduce an efficient procedure for broadening the spectral content of the ILV and ABP inputs to the model by adding white noise. Results from computer simulations demonstrate the effectiveness of broadening the spectral band of input signals to obtain consistent and stable kernel estimates with the use of the LET. Without broadening the band of the ILV and ABP inputs, the LET did not provide stable kernel estimates. Moreover, we extend the LET to the case of multiple inputs in order to accommodate the analysis of the combined effect of ILV and ABP effect on heart rate. Analyzes of data based on the second-order Volterra-Wiener model reveal an important contribution of the second-order kernels to the description of the effect of lung volume and arterial blood pressure on heart rate. Furthermore, physiological effects of the autonomic blocking agents propranolol and atropine on changes in the first- and second-order kernels are also discussed.

  15. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer.

    PubMed

    Yang, Ruijie; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-01-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D90 of 34Gy in 8.5Gy per fraction, and 145Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2Gy per fraction, EQD2) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The Dmean (EQD2) of rectum decreased 22.36Gy in HDR and 17.01Gy in LDR from 30.24Gy in VMAT, respectively. The Dmean (EQD2) of bladder decreased 6.91Gy in HDR and 2.53Gy in LDR from 13.46Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD2) was 80.26, 70.23, and 104.91Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR. PMID:27400663

  16. Determinants in 3Dpol modulate the rate of growth of hepatitis A virus.

    PubMed

    Konduru, Krishnamurthy; Kaplan, Gerardo G

    2010-08-01

    Hepatitis A virus (HAV), an atypical member of the Picornaviridae, grows poorly in cell culture. To define determinants of HAV growth, we introduced a blasticidin (Bsd) resistance gene into the virus genome and selected variants that grew at high concentrations of Bsd. The mutants grew fast and had increased rates of RNA replication and translation but did not produce significantly higher virus yields. Nucleotide sequence analysis and reverse genetic studies revealed that a T6069G change resulting in a F42L amino acid substitution in the viral polymerase (3D(pol)) was required for growth at high Bsd concentrations whereas a silent C7027T mutation enhanced the growth rate. Here, we identified a novel determinant(s) in 3D(pol) that controls the kinetics of HAV growth. PMID:20534860

  17. An updated computational model of rabbit sinoatrial action potential to investigate the mechanisms of heart rate modulation

    PubMed Central

    Severi, Stefano; Fantini, Matteo; Charawi, Lara A; DiFrancesco, Dario

    2012-01-01

    The cellular basis of cardiac pacemaking is still debated. Reliable computational models of the sinoatrial node (SAN) action potential (AP) may help gain a deeper understanding of the phenomenon. Recently, novel models incorporating detailed Ca2+-handling dynamics have been proposed, but they fail to reproduce a number of experimental data, and more specifically effects of ‘funny’ (If) current modifications. We therefore developed a SAN AP model, based on available experimental data, in an attempt to reproduce physiological and pharmacological heart rate modulation. Cell compartmentalization and intracellular Ca2+-handling mechanisms were formulated as in the Maltsev–Lakatta model, focusing on Ca2+-cycling processes. Membrane current equations were revised on the basis of published experimental data. Modifications of the formulation of currents/pumps/exchangers to simulate If blockers, autonomic modulators and Ca2+-dependent mechanisms (ivabradine, caesium, acetylcholine, isoprenaline, BAPTA) were derived from experimental data. The model generates AP waveforms typical of rabbit SAN cells, whose parameters fall within the experimental ranges: 352 ms cycle length, 80 mV AP amplitude, −58 mV maximum diastolic potential (MDP), 108 ms APD50, and 7.1 V s−1 maximum upstroke velocity. Rate modulation by If-blocking drugs agrees with experimental findings: 20% and 22% caesium-induced (5 mm) and ivabradine-induced (3 μm) rate reductions, respectively, due to changes in diastolic depolarization (DD) slope, with no changes in either MDP or take-off potential (TOP). The model consistently reproduces the effects of autonomic modulation: 20% rate decrease with 10 nm acetylcholine and 28% increase with 1 μm isoprenaline, again entirely due to increase in the DD slope, with no changes in either MDP or TOP. Model testing of BAPTA effects showed slowing of rate, −26%, without cessation of beating. Our up-to-date model describes satisfactorily experimental data

  18. Low-Complexity, Digital Encoder/Modulator Developed for High-Data-Rate Satellite B-ISDN Applications

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Space Electronics Division at the NASA Lewis Research Center is developing advanced electronic technologies for the space communications and remote sensing systems of tomorrow. As part of the continuing effort to advance the state-of-the-art in satellite communications and remote sensing systems, Lewis developed a low-cost, modular, programmable, and reconfigurable all-digital encoder-modulator (DEM) for medium- to high-data-rate radiofrequency communication links. The DEM is particularly well suited to high-data-rate downlinks to ground terminals or direct data downlinks from near-Earth science platforms. It can support data rates up to 250 megabits per second (Mbps) and several modulation schemes, including the traditional binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modes, as well as higher order schemes such as 8 phase-shift keying (8PSK) and 16 quadrature amplitude modulation (16QAM). The DEM architecture also can precompensate for channel disturbances and alleviate amplitude degradations caused by nonlinear transponder characteristics.

  19. Time Modulation of the {beta}{sup +}-Decay Rate of H-Like {sup 140}Pr{sup 58+} Ions

    SciTech Connect

    Ivanov, A. N.; Kryshen, E. L.; Pitschmann, M.; Kienle, P.

    2008-10-31

    Recent experimental data at GSI on the rates of the number of daughter ions, produced by the nuclear K-shell electron capture (EC) decays of the H-like ions {sup 140}Pr{sup 58+} and {sup 142}Pm{sup 60+}, suggest that they are modulated in time with periods T{sub EC}{approx_equal}7 sec and amplitudes a{sub EC}{approx_equal}0.20. Since it is known that these ions are unstable also under the nuclear positron ({beta}{sup +}) decays, we study a possible time dependence of the nuclear {beta}{sup +}-decay rate of the H-like {sup 140}Pr{sup 58+} ion. We show that the time dependence of the {beta}{sup +}-decay rate of the H-like {sup 140}Pr{sup 58+} ion as well as any H-like heavy ions cannot be observed.

  20. FPGA-based rate-adaptive LDPC-coded modulation for the next generation of optical communication systems.

    PubMed

    Zou, Ding; Djordjevic, Ivan B

    2016-09-01

    In this paper, we propose a rate-adaptive FEC scheme based on LDPC codes together with its software reconfigurable unified FPGA architecture. By FPGA emulation, we demonstrate that the proposed class of rate-adaptive LDPC codes based on shortening with an overhead from 25% to 42.9% provides a coding gain ranging from 13.08 dB to 14.28 dB at a post-FEC BER of 10-15 for BPSK transmission. In addition, the proposed rate-adaptive LDPC coding combined with higher-order modulations have been demonstrated including QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM, which covers a wide range of signal-to-noise ratios. Furthermore, we apply the unequal error protection by employing different LDPC codes on different bits in 16-QAM and 64-QAM, which results in additional 0.5dB gain compared to conventional LDPC coded modulation with the same code rate of corresponding LDPC code. PMID:27607718

  1. Feeding Ecology Informs Parasite Epidemiology: Prey Selection Modulates Encounter Rate with Echinococcus multilocularis in Urban Coyotes

    PubMed Central

    Liccioli, Stefano; Bialowas, Carly; Ruckstuhl, Kathreen E.; Massolo, Alessandro

    2015-01-01

    We investigated the role of urban coyote feeding ecology in the transmission of Echinococcus multilocularis, the causative agent of Alveolar Echinococcosis in humans. As coyotes can play a main role in the maintenance of this zoonotic parasite within North American urban settings, such study can ultimately aid disease risk management. Between June 2012 and June 2013, we collected 251 coyote feces and conducted trapping of small mammals (n = 971) in five parks in the city of Calgary, Alberta, Canada. We investigated E. multilocularis epidemiology by assessing seasonal variations of coyote diet and the selective consumption of different rodent intermediate host species. Furthermore, accounting for small mammal digestibility and coyote defecation rates we estimated the number of small mammal preys ingested by coyote and consequently, coyote encounter rates with the parasite. Dominant food items included small mammals, fruit and vegetation, although hare and deer were seasonally relevant. The lowest frequency of occurrence per scat of small mammals was recorded in winter (39.4 %), when consumption of deer was highest (36.4 %). However, highest encounter rates (number of infected hosts predated/season) with E. multilocularis (95% CI: 1.0 - 22.4), combined with the lack of predation on non-competent small mammal species, suggest that winter is the critical season for transmission and control of this parasite. Within the small mammal assemblage, voles (Microtus pennsylvanicus and Myodes gapperi) were the selected preys of urban coyotes and likely played a key role for the maintenance of the urban sylvatic life-cycle of E. multilocularis in Calgary. PMID:25768437

  2. Feeding ecology informs parasite epidemiology: prey selection modulates encounter rate with Echinococcus multilocularis in urban coyotes.

    PubMed

    Liccioli, Stefano; Bialowas, Carly; Ruckstuhl, Kathreen E; Massolo, Alessandro

    2015-01-01

    We investigated the role of urban coyote feeding ecology in the transmission of Echinococcus multilocularis, the causative agent of Alveolar Echinococcosis in humans. As coyotes can play a main role in the maintenance of this zoonotic parasite within North American urban settings, such study can ultimately aid disease risk management. Between June 2012 and June 2013, we collected 251 coyote feces and conducted trapping of small mammals (n = 971) in five parks in the city of Calgary, Alberta, Canada. We investigated E. multilocularis epidemiology by assessing seasonal variations of coyote diet and the selective consumption of different rodent intermediate host species. Furthermore, accounting for small mammal digestibility and coyote defecation rates we estimated the number of small mammal preys ingested by coyote and consequently, coyote encounter rates with the parasite. Dominant food items included small mammals, fruit and vegetation, although hare and deer were seasonally relevant. The lowest frequency of occurrence per scat of small mammals was recorded in winter (39.4%), when consumption of deer was highest (36.4%). However, highest encounter rates (number of infected hosts predated/season) with E. multilocularis (95% CI: 1.0-22.4), combined with the lack of predation on non-competent small mammal species, suggest that winter is the critical season for transmission and control of this parasite. Within the small mammal assemblage, voles (Microtus pennsylvanicus and Myodes gapperi) were the selected preys of urban coyotes and likely played a key role for the maintenance of the urban sylvatic life-cycle of E. multilocularis in Calgary. PMID:25768437

  3. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    DOEpatents

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  4. Symbol error rate bound of DPSK modulation system in directional wave propagation

    NASA Astrophysics Data System (ADS)

    Hua, Jingyu; Zhuang, Changfei; Zhao, Xiaomin; Li, Gang; Meng, Qingmin

    This paper presents a new approach to determine the symbol error rate (SER) bound of differential phase shift keying (DPSK) systems in a directional fading channel, where the von Mises distribution is used to illustrate the non-isotropic angle of arrival (AOA). Our approach relies on the closed-form expression of the phase difference probability density function (pdf) in coherent fading channels and leads to expressions of the DPSK SER bound involving a single finite-range integral which can be readily evaluated numerically. Moreover, the simulation yields results consistent with numerical computation.

  5. European rain rate modulation enhanced by changes in the NAO and atmospheric circulation regimes

    NASA Astrophysics Data System (ADS)

    Pokrovsky, Oleg M.

    2009-05-01

    The aim of this study is to classify the circulation patterns in the Atlantic-European sector and to reveal linkages between anomalies in the pressure field over the North Atlantic (e.g. North Atlantic Oscillation (NAO)) and its respective circulation pattern occurrence over continents on the one hand and rain fields on the other hand. Changes in atmospheric circulation over Europe during the past 50 years were examined using both objective (modes of low-frequency variability inferred by regression analysis and objective cluster classification of circulation types—fuzzy logic) and subjective (Hess-Brezowsky classification of weather types) methods. The grid monthly geopotential (H700), wind zonal and meridional velocity components (U850 and V850) as well as the surface atmosphere pressure (SAP) and precipitation fields acquired from the NCEP/NCAR reanalysis dataset (for 1948-1998) were employed in this study. Joint regression analysis and fuzzy logic classification of these fields was a basic tool for finding major circulation regimes. The fuzzy set analysis of these fields revealed that the major circulation regimes over eastern North Atlantic and Europe were determined in summer by three vorticity poles: (1) North-western (Scandinavia), (2) Western Mediterranean and (3) Caucasian. It is worth noting that an anticyclone occurred in the western part of the North Atlantic for both seasons. The Scandinavia cyclone area explains rain rate maximums located in the 50-60° latitude European area and the lower rain rate in Southern Europe because of hot and dry African air inflow. In late fall and winter the vorticity system consists of three other poles: (1) North-western, (2) Northern Africa and (3) Northern Russia (Kara Sea). A zonal circulation type dominates in this case and more precipitation is delivered from the Atlantic. Rain rate is more uniformly distributed in the winter in various latitude belts across Europe than in summer, but more intensive precipitation

  6. Modulated dissolution rate from the inclusion complex of antichagasic benznidazole and cyclodextrin using hydrophilic polymer.

    PubMed

    Sá-Barreto, Lívia C L; Gustmann, Pricila C; Garcia, Felipe S; Maximiano, Flávia P; Novack, Kátia M; Cunha-Filho, Marcílio S S

    2013-01-01

    Benznidazole (BNZ) is the primary chemotherapeutic agent for treating Chagas' disease; however, its poor water solubility and irregular oral absorption lead to the treatment failure in the chronic phase. The aim of this work was to investigate the utility of the polymer hydroxypropyl methylcellulose (HPMC) in controlling the release of BNZ from solid inclusion complexes with cyclodextrin to overcome the problem of its bioavailability. Preliminary studies of solubility were conducted in solution using selected β-cyclodextrin derivatives according to an experimental mixture design. The best cyclodextrin composition was used to produce solid-state systems by kneading in the presence or absence of HPMC. The formulations were characterized by different physico-chemical techniques, including the dissolution rate. Hydroxypropyl-β-cyclodextrin (HPβCD) produced the greatest improvement in drug solubility and was selected for the development of solid systems. Assays confirmed the production of true inclusion complexes between BNZ and HPβCD. The dissolution rate of the BNZ-HPβCD system was markedly increased, while the presence of HPMC retarded drug release. An optimal formulation obtained by the combination of kneading systems developed in appropriate ratios could be a promising drug delivery system with a prolonged therapeutic effect coupled with more balanced bioavailability. The produced systems present interesting perspectives for Chagas' therapy. PMID:22200091

  7. Modulation of Leaf Economic Traits and Rates by Soil Properties, at Global Scale

    NASA Astrophysics Data System (ADS)

    Maire, V.; Wright, I. J.; Reich, P. B.; Batjes, N. H., Jr.; van Bodegom, P. M.; Bhaskar, R.; Santiago, L. S.; Ellsworth, D.; Niinemets, U.; Cornwell, W.

    2014-12-01

    Photosynthesis can be construed as an economic process that optimises the costs of acquisition, transport and utilisation of two substitutable photosynthetic resources: water and nitrogen. The influence of soil fertility on photosynthetic rates and leaf 'economic' traits related with H2O and N costs is poorly quantified in higher plants in comparison with the effects of climate. We set out to address this situation by quantifying the unique and shared contributions to global leaf-trait variation from soils and climate. Using a trait dataset comprising 1509 species from 288 sites, with climate and soil data derived from global datasets, we quantified the effects of soil and climate properties on photosynthetic traits: light-saturated photosynthetic rate (Aarea), stomatal conductance to water vapour (gs), leaf N and P (Narea and Parea) and specific leaf area (SLA). We used mixed regression models, multivariate analyses and variance partitioning. Along a first dimension of soil fertility, soil pH covaried positively with measures of base status and climatic aridity, and negatively with soil organic C content. Along this dimension from low to high soil pH, Narea, Parea and Aarea increased and SLA decreased. Along an independent dimension of soil fertility, gs declined and Parea increased with soil available P (Pavail). Overall, soil variables were stronger predictors of leaf traits than were climate variables, except for SLA. Importantly, soils and climate were not redundant information to explain leaf trait variation but were not additive either. Shared effects of soil and climate dominated over their independent effects on Narea and Parea, while unique effects of soils dominated for Aarea and gs. Three environmental variables were key for explaining variation in leaf traits: soil pH and Pavail, and climatic aridity. Although the reliability of global soils datasets lags behind that of climate datasets our results nonetheless provide compelling evidence that both can

  8. DEVELOPMENT OF A LOW COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

    SciTech Connect

    E. Kelner; D. George; T. Morrow; T. Owen; M. Nored; R. Burkey; A. Minachi

    2005-05-01

    In 1998, Southwest Research Institute began a multi-year project to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype energy meter in 2002-2003 included: (1) refinement of the algorithm used to infer properties of the natural gas stream, such as heating value; (2) evaluation of potential sensing technologies for nitrogen content, improvements in carbon dioxide measurements, and improvements in ultrasonic measurement technology and signal processing for improved speed of sound measurements; (3) design, fabrication and testing of a new prototype energy meter module incorporating these algorithm and sensor refinements; and (4) laboratory and field performance tests of the original and modified energy meter modules. Field tests of the original energy meter module have provided results in close agreement with an onsite gas chromatograph. The original algorithm has also been tested at a field site as a stand-alone application using measurements from in situ instruments, and has demonstrated its usefulness as a diagnostic tool. The algorithm has been revised to use measurement technologies existing in the module to measure the gas stream at multiple states and infer nitrogen content. The instrumentation module has also been modified to incorporate recent improvements in CO{sub 2} and sound speed sensing technology. Laboratory testing of the upgraded module has identified additional testing needed to attain the target accuracy in sound speed measurements and heating value.

  9. Characterization of pulse amplitude and pulse rate modulation for a human vestibular implant during acute electrical stimulation

    NASA Astrophysics Data System (ADS)

    Nguyen, T. A. K.; DiGiovanna, J.; Cavuscens, S.; Ranieri, M.; Guinand, N.; van de Berg, R.; Carpaneto, J.; Kingma, H.; Guyot, J.-P.; Micera, S.; Perez Fornos, A.

    2016-08-01

    Objective. The vestibular system provides essential information about balance and spatial orientation via the brain to other sensory and motor systems. Bilateral vestibular loss significantly reduces quality of life, but vestibular implants (VIs) have demonstrated potential to restore lost function. However, optimal electrical stimulation strategies have not yet been identified in patients. In this study, we compared the two most common strategies, pulse amplitude modulation (PAM) and pulse rate modulation (PRM), in patients. Approach. Four subjects with a modified cochlear implant including electrodes targeting the peripheral vestibular nerve branches were tested. Charge-equivalent PAM and PRM were applied after adaptation to baseline stimulation. Vestibulo-ocular reflex eye movement responses were recorded to evaluate stimulation efficacy during acute clinical testing sessions. Main results. PAM evoked larger amplitude eye movement responses than PRM. Eye movement response axes for lateral canal stimulation were marginally better aligned with PRM than with PAM. A neural network model was developed for the tested stimulation strategies to provide insights on possible neural mechanisms. This model suggested that PAM would consistently cause a larger ensemble firing rate of neurons and thus larger responses than PRM. Significance. Due to the larger magnitude of eye movement responses, our findings strongly suggest PAM as the preferred strategy for initial VI modulation.

  10. Cropping systems modulate the rate and magnitude of soil microbial autotrophic CO2 fixation in soil.

    PubMed

    Wu, Xiaohong; Ge, Tida; Wang, Wei; Yuan, Hongzhao; Wegner, Carl-Eric; Zhu, Zhenke; Whiteley, Andrew S; Wu, Jinshui

    2015-01-01

    The effect of different cropping systems on CO2 fixation by soil microorganisms was studied by comparing soils from three exemplary cropping systems after 10 years of agricultural practice. Studied cropping systems included: continuous cropping of paddy rice (rice-rice), rotation of paddy rice and rapeseed (rice-rapeseed), and rotated cropping of rapeseed and corn (rapeseed-corn). Soils from different cropping systems were incubated with continuous (14)C-CO2 labeling for 110 days. The CO2-fixing bacterial communities were investigated by analyzing the cbbL gene encoding ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO). Abundance, diversity and activity of cbbL-carrying bacteria were analyzed by quantitative PCR, cbbL clone libraries and enzyme assays. After 110 days incubation, substantial amounts of (14)C-CO2 were incorporated into soil organic carbon ((14)C-SOC) and microbial biomass carbon ((14)C-MBC). Rice-rice rotated soil showed stronger incorporation rates when looking at (14)C-SOC and (14)C-MBC contents. These differences in incorporation rates were also reflected by determined RubisCO activities. (14)C-MBC, cbbL gene abundances and RubisCO activity were found to correlate significantly with (14)C-SOC, indicating cbbL-carrying bacteria to be key players for CO2 fixation in these soils. The analysis of clone libraries revealed distinct cbbL-carrying bacterial communities for the individual soils analyzed. Most of the identified operational taxonomic units (OTU) were related to Nitrobacter hamburgensis, Methylibium petroleiphilum, Rhodoblastus acidophilus, Bradyrhizobium, Cupriavidus metallidurans, Rubrivivax, Burkholderia, Stappia, and Thiobacillus thiophilus. OTUs related to Rubrivivax gelatinosus were specific for rice-rice soil. OTUs linked to Methylibium petroleiphilum were exclusively found in rice-rapeseed soil. Observed differences could be linked to differences in soil parameters such as SOC. We conclude that the long-term application of

  11. Cropping systems modulate the rate and magnitude of soil microbial autotrophic CO2 fixation in soil

    PubMed Central

    Wu, Xiaohong; Ge, Tida; Wang, Wei; Yuan, Hongzhao; Wegner, Carl-Eric; Zhu, Zhenke; Whiteley, Andrew S.; Wu, Jinshui

    2015-01-01

    The effect of different cropping systems on CO2 fixation by soil microorganisms was studied by comparing soils from three exemplary cropping systems after 10 years of agricultural practice. Studied cropping systems included: continuous cropping of paddy rice (rice-rice), rotation of paddy rice and rapeseed (rice-rapeseed), and rotated cropping of rapeseed and corn (rapeseed-corn). Soils from different cropping systems were incubated with continuous 14C-CO2 labeling for 110 days. The CO2-fixing bacterial communities were investigated by analyzing the cbbL gene encoding ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO). Abundance, diversity and activity of cbbL-carrying bacteria were analyzed by quantitative PCR, cbbL clone libraries and enzyme assays. After 110 days incubation, substantial amounts of 14C-CO2 were incorporated into soil organic carbon (14C-SOC) and microbial biomass carbon (14C-MBC). Rice-rice rotated soil showed stronger incorporation rates when looking at 14C-SOC and 14C-MBC contents. These differences in incorporation rates were also reflected by determined RubisCO activities. 14C-MBC, cbbL gene abundances and RubisCO activity were found to correlate significantly with 14C-SOC, indicating cbbL-carrying bacteria to be key players for CO2 fixation in these soils. The analysis of clone libraries revealed distinct cbbL-carrying bacterial communities for the individual soils analyzed. Most of the identified operational taxonomic units (OTU) were related to Nitrobacter hamburgensis, Methylibium petroleiphilum, Rhodoblastus acidophilus, Bradyrhizobium, Cupriavidus metallidurans, Rubrivivax, Burkholderia, Stappia, and Thiobacillus thiophilus. OTUs related to Rubrivivax gelatinosus were specific for rice-rice soil. OTUs linked to Methylibium petroleiphilum were exclusively found in rice-rapeseed soil. Observed differences could be linked to differences in soil parameters such as SOC. We conclude that the long-term application of cropping systems

  12. Enhanced modulation rate in platinum-diffused resonant-cavity light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Chang, L. B.; Yeh, D. H.; Hsieh, L. Z.; Zeng, S. H.

    2005-11-01

    This study is focused on the modulation response of resonant-cavity light-emitting diodes (RCLEDs). Platinum (Pt) atoms are diffused into the 660 nm RCLED epitaxial layers to increase the concentration of recombination centers and to improve the modulation speed. The RCLED has an AlInGaP multi-quantum-well active layer which was embedded into AlGaAs-distributed Bragg reflectors to form a one-wavelength (1-λ) optical resonator. Afterwards, the deep-level Pt impurity was diffused into the RCLED and an improved average rise time, from 18.07 to 12.21 ns, was obtained. The corresponding modulation frequency can be increased from 19.54 to 30.21 MHz.

  13. Use of Melt Flow Rate Test in Reliability Study of Thermoplastic Encapsulation Materials in Photovoltaic Modules

    SciTech Connect

    Moseley, J.; Miller, D.; Shah, Q.-U.-A. S. J.; Sakurai, K.; Kempe, M.; Tamizhmani, G.; Kurtz, S.

    2011-10-01

    Use of thermoplastic materials as encapsulants in photovoltaic (PV) modules presents a potential concern in terms of high temperature creep, which should be evaluated before thermoplastics are qualified for use in the field. Historically, the issue of creep has been avoided by using thermosetting polymers as encapsulants, such as crosslinked ethylene-co-vinyl acetate (EVA). Because they lack crosslinked networks, however, thermoplastics may be subject to phase transitions and visco-elastic flow at the temperatures and mechanical stresses encountered by modules in the field, creating the potential for a number of reliability and safety issues. Thermoplastic materials investigated in this study include PV-grade uncured-EVA (without curing agents and therefore not crosslinked); polyvinyl butyral (PVB); thermoplastic polyurethane (TPU); and three polyolefins (PO), which have been proposed for use as PV encapsulation. Two approaches were used to evaluate the performance of these materials as encapsulants: module-level testing and a material-level testing.

  14. Exercise intensity modulates brachial artery retrograde blood flow and shear rate during leg cycling in hypoxia.

    PubMed

    Iwamoto, Erika; Katayama, Keisho; Ishida, Koji

    2015-06-01

    The purpose of this study was to elucidate the effect of exercise intensity on retrograde blood flow and shear rate (SR) in an inactive limb during exercise under normoxic and hypoxic conditions. The subjects performed two maximal exercise tests on a semi-recumbent cycle ergometer to estimate peak oxygen uptake (V˙O2peak) while breathing normoxic (inspired oxygen fraction [FIO2 = 0.21]) and hypoxic (FIO2 = 0.12 or 0.13) gas mixtures. Subjects then performed four exercise bouts at the same relative intensities (30 and 60% V˙O2peak) for 30 min under normoxic or hypoxic conditions. Brachial artery diameter and blood velocity were simultaneously recorded, using Doppler ultrasonography. Retrograde SR was enhanced with increasing exercise intensity under both conditions at 10 min of exercise. Thereafter, retrograde blood flow and SR in normoxia returned to pre-exercise levels, with no significant differences between the two exercise intensities. In contrast, retrograde blood flow and SR in hypoxia remained significantly elevated above baseline and was significantly greater at 60% than at 30% V˙O2peak. We conclude that differences in exercise intensity affect brachial artery retrograde blood flow and SR during prolonged exercise under hypoxic conditions. PMID:26038470

  15. Modulation of Intersystem Crossing Rate by Minor Ligand Modifications in Cyclometalated Platinum(II) Complexes.

    PubMed

    Shafikov, Marsel Z; Kozhevnikov, Dmitry N; Bodensteiner, Michael; Brandl, Fabian; Czerwieniec, Rafał

    2016-08-01

    Photophysical properties of four new platinum(II) complexes comprising extended ppy (Hppy = 2-phenylpyridine) and thpy (Hthpy = 2-(2'-thienyl)pyridine) cyclometalated ligands and acetylacetonate (acac) are reported. Substitution of the benzene ring of Pt-ppy complexes 1 and 2 with a more electron-rich thiophene of Pt-thpy complexes 3 and 4 leads to narrowing of the HOMO-LUMO gap and thus to a red shift of the lowest energy absorption band and phosphorescence band, as expected for low-energy excited states of the intraligand/metal-to-ligand charge transfer character. However, in addition to these conventional spectral shifts, another, at first unexpected, substitution effect occurs. Pt-thpy complexes 3 and 4 are dual emissive showing fluorescence about 6000 cm(-1) (∼0.75 eV) higher in energy relative to the phosphorescence band, while for Pt-ppy complexes 1 and 2 only phosphorescence is observed. For dual-emissive complexes 3 and 4, ISC rates kISC are estimated to be in order of 10(9)-10(10) s(-1), while kISC of Pt-ppy complexes 1 and 2 is much faster amounting to 10(12) s(-1) or more. The relative intensities of the fluorescence and phosphorescence signals of Pt-thpy complexes 3 and 4 depend on the excitation wavelength, showing that hyper-intersystem crossing (HISC) in these complexes is observably significant. PMID:27388146

  16. Tai Chi Chuan modulates heart rate variability during abdominal breathing in elderly adults.

    PubMed

    Wei, Gao-Xia; Li, You-Fa; Yue, Xiao-Lin; Ma, Xiao; Chang, Yu-Kai; Yi, Long-Yan; Li, Jing-Cheng; Zuo, Xi-Nian

    2016-03-01

    Tai Chi Chuan (TCC) practice is currently intentionally applied in clinical populations, especially those with cardiovascular diseases because of its potential benefits on the autonomic nervous system. The long-term effect of TCC practice on heart rate variability (HRV) remains largely unknown. In this study, we recruited 23 TCC practitioners whose experience averaged approximately 21 years and 19 controls matched by age, sex and education to examine the effect of TCC practice on the autonomic nervous system during a resting state and during an abdominal breathing state. HRV was measured by traditional electrocardiogram (ECG) recording. The results showed that the low frequency, total power frequency, and normalized low frequency components and the low-frequency/high-frequency ratio were significantly higher, whereas the normalized high frequency was significantly lower in the TCC practitioners relative to controls during the abdominal breathing state. However, we did not detect any significant difference in the HRV measures during the resting state between the two groups. Additionally, TCC experience did not correlate with HRV components either in the abdominal state or the resting state in the TCC group. Considering all of these findings, we suggest that TCC improves vagal activity and the balance between sympathetic and parasympathetic activity during the relaxation state. This study also provides direct physiological evidence for the role of TCC practice in relaxation. PMID:26377754

  17. Exercise intensity modulates brachial artery retrograde blood flow and shear rate during leg cycling in hypoxia

    PubMed Central

    Iwamoto, Erika; Katayama, Keisho; Ishida, Koji

    2015-01-01

    The purpose of this study was to elucidate the effect of exercise intensity on retrograde blood flow and shear rate (SR) in an inactive limb during exercise under normoxic and hypoxic conditions. The subjects performed two maximal exercise tests on a semi-recumbent cycle ergometer to estimate peak oxygen uptake (O2peak) while breathing normoxic (inspired oxygen fraction [FIO2 = 0.21]) and hypoxic (FIO2 = 0.12 or 0.13) gas mixtures. Subjects then performed four exercise bouts at the same relative intensities (30 and 60% O2peak) for 30 min under normoxic or hypoxic conditions. Brachial artery diameter and blood velocity were simultaneously recorded, using Doppler ultrasonography. Retrograde SR was enhanced with increasing exercise intensity under both conditions at 10 min of exercise. Thereafter, retrograde blood flow and SR in normoxia returned to pre-exercise levels, with no significant differences between the two exercise intensities. In contrast, retrograde blood flow and SR in hypoxia remained significantly elevated above baseline and was significantly greater at 60% than at 30% O2peak. We conclude that differences in exercise intensity affect brachial artery retrograde blood flow and SR during prolonged exercise under hypoxic conditions. PMID:26038470

  18. Heart rate modulation in bystanding geese watching social and non-social events

    PubMed Central

    Wascher, Claudia A.F; Scheiber, Isabella B.R; Kotrschal, Kurt

    2008-01-01

    Simply observing other individuals interacting has been shown to affect subsequent behaviour and also hormones in ‘bystander’ individuals. However, immediate physiological responses of an observer have been hardly investigated. Here we present results on individuals' heart rate (HR) responses during various situations, which occur regularly in a flock of greylag geese (Anser anser, e.g. agonistic encounters, vehicles passing by). We recorded simultaneously HR and behaviour of 21 semi-tame free-roaming geese, equipped with fully implanted transmitters. We considered 304 social and 81 non-social events during which the focal individuals did not respond behaviourally. Independent of the spatial distance to the event, these HR responses were significantly greater in social contexts (e.g. departing or landing geese, agonistic interactions) than in non-social situations (e.g. vehicles passing by, thunder). Focal individuals showed a significantly higher maximum HR as well as a greater HR increase in response to agonistic interactions, in which the pair partner or a family member was involved, as compared with a non-affiliated goose. Also, HR was significantly higher when the bystander watched non-affiliated geese interacting, which were higher ranking than the focal. We conclude that these differences are due to different relevance of the recorded events for the focal individual, depending on the individuals involved in the observed interaction. PMID:18430645

  19. High-repetition-rate Q-modulation in solid-state laser using fast saturable absorber V:YAG

    NASA Astrophysics Data System (ADS)

    Ma, Jia-Sai; Wang, Feng; Li, Pei-Xin; Hu, Wei-Wei; Yin, Chun-Hao; Xu, Jin-Long

    2015-07-01

    A high-repetition-rate Q-modulation operation in a solid-state Nd:GdVO4 laser with a V3+:YAG saturable absorber has been demonstrated in this paper. The V3+:YAG crystal behaves as a fast saturable absorber in this laser because of its very short lifetime of 22 ns. Taking advantage of such fast bleaching recovery and effective cooling of the V:YAG by a home-made copper holder, we realized a pulse repetition rate of 2.4 MHz, which is, to our best knowledge, the maximum among the reported passively Q-switched lasers. The corresponding average output power and pulse width were 1.28 W and 170 ns, respectively, giving a slope efficiency of 15.9% and a pulse energy of 0.53 µJ. This compact high-repetition-rate Q-switched laser offers a potential application in the construction of low-cost, integrated and portable sensing detection equipment which needs a high laser pulse repetition rate.

  20. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    SciTech Connect

    Buttafava, Mauro Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto; Dalla Mora, Alberto

    2014-08-15

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor.

  1. Vagal modulation of resting heart rate in rats: the role of stress, psychosocial factors, and physical exercise

    PubMed Central

    Carnevali, Luca; Sgoifo, Andrea

    2014-01-01

    In humans, there are large individual differences in the levels of vagal modulation of resting heart rate (HR). High levels are a recognized index of cardiac health, whereas low levels are considered an important risk factor for cardiovascular morbidity and mortality. Several factors are thought to contribute significantly to this inter-individual variability. While regular physical exercise seems to induce an increase in resting vagal tone, chronic life stress, and psychosocial factors such as negative moods and personality traits appear associated with vagal withdrawal. Preclinical research has been attempting to clarify such relationships and to provide insights into the neurobiological mechanisms underlying vagal tone impairment/enhancement. This paper focuses on rat studies that have explored the effects of stress, psychosocial factors and physical exercise on vagal modulation of resting HR. Results are discussed with regard to: (i) individual differences in resting vagal tone, cardiac stress reactivity and arrhythmia vulnerability; (ii) elucidation of the neurobiological determinants of resting vagal tone. PMID:24715877

  2. DEVELOPMENT OF A LOW-COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE

    SciTech Connect

    E. Kelner; T.E. Owen; D.L. George; A. Minachi; M.G. Nored; C.J. Schwartz

    2004-03-01

    In 1998, Southwest Research Institute{reg_sign} began a multi-year project co-funded by the Gas Research Institute (GRI) and the U.S. Department of Energy. The project goal is to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype retrofit natural gas energy flow meter in 2000-2001 included: (1) evaluation of the inferential gas energy analysis algorithm using supplemental gas databases and anticipated worst-case gas mixtures; (2) identification and feasibility review of potential sensing technologies for nitrogen diluent content; (3) experimental performance evaluation of infrared absorption sensors for carbon dioxide diluent content; and (4) procurement of a custom ultrasonic transducer and redesign of the ultrasonic pulse reflection correlation sensor for precision speed-of-sound measurements. A prototype energy meter module containing improved carbon dioxide and speed-of-sound sensors was constructed and tested in the GRI Metering Research Facility at SwRI. Performance of this module using transmission-quality natural gas and gas containing supplemental carbon dioxide up to 9 mol% resulted in gas energy determinations well within the inferential algorithm worst-case tolerance of {+-}2.4 Btu/scf (nitrogen diluent gas measured by gas chromatograph). A two-week field test was performed at a gas-fired power plant to evaluate the inferential algorithm and the data acquisition requirements needed to adapt the prototype energy meter module to practical field site conditions.

  3. Effects of heart rate variability biofeedback on cardiovascular responses and autonomic sympathovagal modulation following stressor tasks in prehypertensives.

    PubMed

    Chen, S; Sun, P; Wang, S; Lin, G; Wang, T

    2016-02-01

    Autonomic dysfunction is implicated in prehypertension, and previous studies have suggested that therapies that improve modulation of sympathovagal balance, such as biofeedback and slow abdominal breathing, are effective in patients with prehypertension at rest. However, considering that psychophysiological stressors may be associated with greater cardiovascular risk in prehypertensives, it is important to investigate whether heart rate variability biofeedback (HRV-BF) results in equivalent effects on autonomic cardiovascular responses control during stressful conditions in prehypertensives. A total of 32 college students with prehypertension were enrolled and randomly assigned to HRV-BF (n=12), slow abdominal breathing (SAB, n=10) or no treatment (control, n=10) groups. Then, a training experiment consisting of 15 sessions was employed to compare the effect of each intervention on the following cardiovascular response indicators before and after intervention: heart rate (HR); heart rate variability (HRV) components; blood volume pulse amplitude (BVPamp); galvanic skin response; respiration rate (RSP); and blood pressure. In addition, the cold pressor test and the mental arithmetic challenge test were also performed over two successive days before and after the invention as well as after 3 months of follow-up. A significant decrease in HR and RSP and a significant increase in BVPamp were observed after the HRV-BF intervention (P<0.001). For the HRV analysis, HRV-BF significantly reduced the ratio of low-frequency power to high-frequency power (the LF/HF ratio, P<0.001) and increased the normalized high-frequency power (HFnm) (P<0.001) during the stress tests, and an added benefit over SAB by improving HRV was also observed. In the 3-month follow-up study, similar effects on RSP, BVPamp, LF/HF and HFnm were observed in the HRV-BF group compared with the SAB group. HRV-BF training contributes to the beneficial effect of reducing the stress-related cardiovascular

  4. Behavior-related pauses in simple-spike activity of mouse Purkinje cells are linked to spike rate modulation.

    PubMed

    Cao, Ying; Maran, Selva K; Dhamala, Mukesh; Jaeger, Dieter; Heck, Detlef H

    2012-06-20

    Purkinje cells (PCs) in the mammalian cerebellum express high-frequency spontaneous activity with average spike rates between 30 and 200 Hz. Cerebellar nuclear (CN) neurons receive converging input from many PCs, resulting in a continuous barrage of inhibitory inputs. It has been hypothesized that pauses in PC activity trigger increases in CN spiking activity. A prediction derived from this hypothesis is that pauses in PC simple-spike activity represent relevant behavioral or sensory events. Here, we asked whether pauses in the simple-spike activity of PCs related to either fluid licking or respiration, play a special role in representing information about behavior. Both behaviors are widely represented in cerebellar PC simple-spike activity. We recorded PC activity in the vermis and lobus simplex of head-fixed mice while monitoring licking and respiratory behavior. Using cross-correlation and Granger causality analysis, we examined whether short interspike intervals (ISIs) had a different temporal relationship to behavior than long ISIs or pauses. Behavior-related simple-spike pauses occurred during low-rate simple-spike activity in both licking- and breathing-related PCs. Granger causality analysis revealed causal relationships between simple-spike pauses and behavior. However, the same results were obtained from an analysis of surrogate spike trains with gamma ISI distributions constructed to match rate modulations of behavior-related Purkinje cells. Our results therefore suggest that the occurrence of pauses in simple-spike activity does not represent additional information about behavioral or sensory events that goes beyond the simple-spike rate modulations. PMID:22723707

  5. Metal-to-Insulator Transition in Anatase TiO2 Thin Films Induced by Growth Rate Modulation

    SciTech Connect

    Tachikawa, T; Minohara, M.; Nakanishi, Y.; Hikita, Y.; Yoshita, M.; Akiyama, H.; Bell, C.; Hwang, H.Y.

    2012-06-21

    We demonstrate control of the carrier density of single phase anatase TiO{sub 2} thin films by nearly two orders of magnitude by modulating the growth kinetics during pulsed laser deposition, under fixed thermodynamic conditions. The resistivity and the intensity of the photoluminescence spectra of these TiO{sub 2} samples, both of which correlate with the number of oxygen vacancies, are shown to depend strongly on the growth rate. A quantitative model is used to explain the carrier density changes.

  6. Rate modulation of human anconeus motor units during high-intensity dynamic elbow extensions.

    PubMed

    Cowling, Brianna L; Harwood, Brad; Copithorne, David B; Rice, Charles L

    2016-08-01

    Investigations of high-intensity isometric fatiguing protocols report decreases in motor unit firing rates (MUFRs), but little is known regarding changes in MUFRs following fatigue induced by high-intensity dynamic contractions. Our purpose was to evaluate MUFRs of the anconeus (an accessory elbow extensor) and elbow extension power production as a function of time to task failure (TTF) during high-velocity fatiguing concentric contractions against a moderately heavy resistance. Fine-wire intramuscular electrode pairs were inserted into the anconeus to record MUs in 12 male participants (25 ± 3 yr), over repeated sessions on separate days. MUs were tracked throughout a three-stage, varying load dynamic elbow extension protocol designed to extend the task duration for >1 min thereby inducing substantial fatigue. Mean MUFRs and peak power were calculated for three relative time ranges: 0-15% TTF (beginning), 45-60% TTF (middle) and 85-100% TTF (end). Mean duration of the overall fatigue protocol was ∼80 s. Following the protocol, isometric maximum voluntary contraction (MVC), highest velocity at 35% MVC load, and peak power decreased 37, 60, and 64% compared with baseline, respectively. Data from 20 anconeus MUs tracked successfully throughout the protocol indicated a reduction in MUFRs in relation to power loss from 36 Hz/160 W (0-15% TTF) to 28 Hz/97 W (45-60% TTF) to 23 Hz/43 W (85-100% TTF). During these high-intensity maximal effort concentric contractions, anconeus MUFRs decreased substantially (>35%). Although the absolute MUFRs were higher in the present study than those reported previously for other muscles during sustained high-intensity isometric tasks, the relative decrease in MUFRs was similar between the two tasks. PMID:27283910

  7. Efficient creation of maximally entangled states by modulation of tunneling rates

    SciTech Connect

    Watanabe, Gentaro

    2010-02-15

    For systems described by the two-site Bose-Hubbard Hamiltonian, I show that a sinusoidal modulation of the tunneling matrix element assists higher-order cotunneling processes. Using this mechanism, I propose an efficient scheme for creating a coherent superposition of states in which all particles are either on one site or all on the other site, the so-called NOON state. This scheme yields an almost perfect NOON state periodically. For larger numbers of particles, further reduction of the time to create the state is possible if more than one modulation frequency is employed. With this scheme, NOON states with a larger number of particles could be realized with state-of-the-art techniques for cold Bose gases in a double-well potential.

  8. A megawatt solid-state modulator for high repetition rate pulse generation.

    PubMed

    Wang, Y; Pribyl, P; Gekelman, W

    2016-02-01

    A novel solid-state modulator capable of generating rapid consecutive power pulses is constructed to facilitate experiments on plasma interaction with high power microwave pulses. The modulator is designed to output a 100 kHz tone burst, which consists of up to 10 pulses, each with 1 μs duration and 1 MW peak power. The pulses are formed by discharging a total of 480 μF capacitors through 24 synchronized MOSFETs and 6 step-up transformers. The highly modular design, as a replacement of an old single-pulse version used in earlier experiments which employs a pulse forming network, brings great flexibility and wide potential to its application. A systematic cost-effectiveness analysis is also presented. PMID:26931851

  9. A megawatt solid-state modulator for high repetition rate pulse generation

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Pribyl, P.; Gekelman, W.

    2016-02-01

    A novel solid-state modulator capable of generating rapid consecutive power pulses is constructed to facilitate experiments on plasma interaction with high power microwave pulses. The modulator is designed to output a 100 kHz tone burst, which consists of up to 10 pulses, each with 1 μs duration and 1 MW peak power. The pulses are formed by discharging a total of 480 μF capacitors through 24 synchronized MOSFETs and 6 step-up transformers. The highly modular design, as a replacement of an old single-pulse version used in earlier experiments which employs a pulse forming network, brings great flexibility and wide potential to its application. A systematic cost-effectiveness analysis is also presented.

  10. High repetition rate multi-channel source of high-power rf-modulated pulses

    NASA Astrophysics Data System (ADS)

    Ulmaskulov, M. R.; Pedos, M. S.; Rukin, S. N.; Sharypov, K. A.; Shpak, V. G.; Shunailov, S. A.; Yalandin, M. I.; Romanchenko, I. V.; Rostov, V. V.

    2015-07-01

    This paper presents the results of testing a high voltage pulse generator based on parallel gyromagnetic nonlinear transmission lines filled with saturable ferrite. The generator is capable of producing almost identical stable rf-modulated nanosecond high voltage pulses in each of the two, or four, parallel output channels. The output voltage amplitude in each channel can reach -285 or -180 kV, respectively, with a rf modulation depth of up to 60%. Drive pulses were produced as the packets of duration 1-5 s at a pulse repetition frequency of 800 Hz using a driver equipped with all-solid-state switches. Splitting the driver pulse provided electric field strengths in the channels which were below the breakdown field strength of the transmission lines. As a result, the use of nonlinear transmission lines of reduced diameter made it possible to increase the center frequency of the excited rf oscillations to ˜2 GHz.

  11. Gravitational focusing and substructure effects on the rate modulation in direct dark matter searches

    SciTech Connect

    Nobile, Eugenio Del; Gelmini, Graciela B.; Witte, Samuel J.

    2015-08-21

    We study how gravitational focusing (GF) of dark matter by the Sun affects the annual and biannual modulation of the expected signal in non-directional direct dark matter searches, in the presence of dark matter substructure in the local dark halo. We consider the Sagittarius stream and a possible dark disk, and show that GF suppresses some, but not all, of the distinguishing features that would characterize substructure of the dark halo were GF neglected.

  12. Light-Limited Growth Rate Modulates Nitrate Inhibition of Dinitrogen Fixation in the Marine Unicellular Cyanobacterium Crocosphaera watsonii

    PubMed Central

    Garcia, Nathan S.; Hutchins, David A.

    2014-01-01

    Biological N2 fixation is the dominant supply of new nitrogen (N) to the oceans, but is often inhibited in the presence of fixed N sources such as nitrate (NO3−). Anthropogenic fixed N inputs to the ocean are increasing, but their effect on marine N2 fixation is uncertain. Thus, global estimates of new oceanic N depend on a fundamental understanding of factors that modulate N source preferences by N2-fixing cyanobacteria. We examined the unicellular diazotroph Crocosphaera watsonii (strain WH0003) to determine how the light-limited growth rate influences the inhibitory effects of fixed N on N2 fixation. When growth (µ) was limited by low light (µ = 0.23 d−1), short-term experiments indicated that 0.4 µM NH4+ reduced N2-fixation by ∼90% relative to controls without added NH4+. In fast-growing, high-light-acclimated cultures (µ = 0.68 d−1), 2.0 µM NH4+ was needed to achieve the same effect. In long-term exposures to NO3−, inhibition of N2 fixation also varied with growth rate. In high-light-acclimated, fast-growing cultures, NO3− did not inhibit N2-fixation rates in comparison with cultures growing on N2 alone. Instead NO3− supported even faster growth, indicating that the cellular assimilation rate of N2 alone (i.e. dinitrogen reduction) could not support the light-specific maximum growth rate of Crocosphaera. When growth was severely light-limited, NO3− did not support faster growth rates but instead inhibited N2-fixation rates by 55% relative to controls. These data rest on the basic tenet that light energy is the driver of photoautotrophic growth while various nutrient substrates serve as supports. Our findings provide a novel conceptual framework to examine interactions between N source preferences and predict degrees of inhibition of N2 fixation by fixed N sources based on the growth rate as controlled by light. PMID:25503244

  13. Demodulator for binary-phase modulated signals having a variable clock rate

    NASA Technical Reports Server (NTRS)

    Wu, Ta Tzu (Inventor)

    1976-01-01

    Method and apparatus for demodulating binary-phase modulated signals recorded on a magnetic stripe on a card as the card is manually inserted into a card reader. Magnetic transitions are sensed as the card is read and the time interval between immediately preceeding basic transitions determines the duration of a data sampling pulse which detects the presence or absence of an intermediate transition pulse indicative of two respective logic states. The duration of the data sampling pulse is approximately 75 percent of the preceeding interval between basic transitions to permit tracking succeeding time differences in basic transition intervals of up to approximately 25 percent.

  14. Daily modulation as a smoking gun of dark matter with significant stopping rate

    NASA Astrophysics Data System (ADS)

    Kouvaris, Chris; Shoemaker, Ian M.

    2014-11-01

    We point out that for a range of parameters, the flux of DM may be stopped significantly by its interactions with the Earth. This can significantly degrade the sensitivity of direct detection experiments to DM candidates with large interactions with terrestrial nuclei. We find that a significant region of parameter space remains unconstrained for DM ≲ a few GeV. For DM candidates with moderate levels of stopping power, the flux of DM may be blocked from below but not above a detector, thereby producing a novel daily modulation. This can be explored by low threshold detectors placed on the surface or in shallow sites in the south hemisphere.

  15. Impact of small MU/segment and dose rate on delivery accuracy of volumetric-modulated arc therapy (VMAT).

    PubMed

    Huang, Long; Zhuang, Tingliang; Mastroianni, Anthony; Djemil, Toufik; Cui, Taoran; Xia, Ping

    2016-01-01

    Volumetric-modulated arc therapy (VMAT) plans may require more control points (or segments) than some of fixed-beam IMRT plans that are created with a limited number of segments. Increasing number of control points in a VMAT plan for a given prescription dose could create a large portion of the total number of segments with small number monitor units (MUs) per segment. The purpose of this study is to investigate the impact of the small number MU/segment on the delivery accuracy of VMAT delivered with various dose rates. Ten patient datasets were planned for hippocampus sparing for whole brain irradiation. For each dataset, two VMAT plans were created with maximum dose rates of 600 MU/min (the maximum field size of 21 × 40 cm2) and 1000 MU/min (the maximum field size of 15 × 15 cm2) for a daily dose of 3 Gy. Without reoptimization, the daily dose of these plans was purposely reduced to 1.5 Gy and 1.0 Gy while keeping the same total dose. Using the two dose rates and three different daily doses, six VMAT plans for each dataset were delivered to a physical phantom to investigate how the changes of dose rate and daily doses impact on delivery accuracy. Using the gamma index, we directly compared the delivered planar dose profiles with the reduced daily doses (1.5 Gy and 1.0 Gy) to the delivered planar dose at 3 Gy daily dose, delivered at dose rate of 600 MU/min and 1000 MU/min, respectively. The average numbers of segments with MU/segment ≤ 1 were 35 ± 8, 87 ± 6 for VMAT-600 1.5 Gy, VMAT-600 1 Gy plans, and 30 ± 7 and 42 ± 6 for VMAT-1000 1.5 Gy and VMAT-1000 1 Gy plans, respectively. When delivered at 600 MU/min dose rate, the average gamma index passing rates (1%/1 mm criteria) of comparing delivered 1.5 Gy VMAT planar dose profiles to 3.0 Gy VMAT delivered planar dose profiles was 98.28% ± 1.66%, and the average gamma index passing rate of comparing delivered 1.0 Gy VMAT planar dose to 3.0 Gy VMAT delivered planar dose was 83.75% ± 4.86%. If using 2%/2mm

  16. Pitch of amplitude-modulated irregular-rate stimuli in acoustic and electric hearing

    NASA Astrophysics Data System (ADS)

    van Wieringen, Astrid; Carlyon, Robert P.; Long, Christopher J.; Wouters, Jan

    2003-09-01

    The pitch of stimuli was studied under conditions where place-of-excitation was held constant, and where pitch was therefore derived from ``purely temporal'' cues. In experiment 1, the acoustical and electrical pulse trains consisted of pulses whose amplitudes alternated between a high and a low value, and whose interpulse intervals alternated between 4 and 6 ms. The attenuated pulses occurred after the 4-ms intervals in condition A, and after the 6-ms intervals in condition B. For both normal-hearing subjects and cochlear implantees, the period of an isochronous pulse train equal in pitch to this ``4-6'' stimulus increased from near 6 ms at the smallest modulation depth to nearly 10 ms at the largest depth. Additionally, the modulated pulse trains in condition A were perceived as being lower in pitch than those in condition B. Data are interpreted in terms of increased refractoriness in condition A, where the larger pulses are more closely followed by the smaller ones than in condition B. Consistent with this conclusion, the A-B difference was reduced at longer interpulse intervals. These findings provide a measure of supra-threshold effects of refractoriness on pitch perception, and increase our understanding of coding of temporal information in cochlear implant speech processing schemes.

  17. Effects of Patrol Operation on Hydration Status and Autonomic Modulation of Heart Rate of Brazilian Peacekeepers in Haiti.

    PubMed

    Duarte, Antonio F A; Morgado, Jairo J M

    2015-11-01

    The stress of operational missions may challenge the maintenance of body homeostasis, affecting soldiers' cardiac autonomic control, promoting dehydration, and compromising performance. Therefore, we aimed to determine the effects of peacekeeper patrol operation in Haiti on soldiers' hydration status and cardiac autonomic modulation, and to determine whether fluctuations in autonomic modulation were associated with changes in hydration status, energy expenditure (EE), and aerobic fitness (V[Combining Dot Above]O2max). A group of 20 soldiers (23.5 ± 4.7 years; V[Combining Dot Above]O2max 52.9 ± 4.5 ml·kg⁻¹·min⁻¹) completed an operational patrol mission with a mean duration of 160.6 ± 28.6 minutes. Before (Pre) and after (Post) the operation, the soldiers' body masses (BMs) were measured and 5-minute heart rate interbeat (R-R) intervals were recorded at rest to estimate heart rate variability (low-frequency [LF] and high-frequency [HF] power, and sympathovagal balance [LF/HF]). During the mission, EE was estimated using heart rate (HR) monitors. Changes from Pre to Post in BM (%BM loss) and LF/HF (ΔLF/HF) were used to evaluate the soldiers' dehydration levels and autonomic modulation, respectively. The mean EE was 711.0 ± 208.7 kcal. From pre to post, increases (p < 0.01) were noted in LF normalized units (n.u.) and LF/HF and decreases (p < 0.01) were noted in BM, R-R interval, and HF n.u. The variation in ΔLF/HF correlated with EE (r = 0.49; p = 0.02), V[Combining Dot Above]O2max (r = -0.42; p = 0.05), and %BM loss (r = 0.53; p = 0.02). The results demonstrated that an operational peacekeeper patrol with an approximate duration of 160 minutes promoted both dehydration and an imbalance in the autonomic modulation of soldiers' HR. The reduction in sympathovagal balance correlated with EE, dehydration, and aerobic conditioning. PMID:26506204

  18. SU-E-T-421: Feasibility Study of Volumetric Modulated Arc Therapy with Constant Dose Rate for Endometrial Cancer

    SciTech Connect

    Yang, R; Wang, J

    2014-06-01

    Purpose: To investigate the feasibility, efficiency, and delivery accuracy of volumetric modulated arc therapy with constant dose rate (VMAT-CDR) for whole-pelvic radiotherapy (WPRT) of endometrial cancer. Methods: The nine-Field intensity-modulated radiotherapy (IMRT), VMAT with variable dose-rate (VMAT-VDR), and VMAT-CDR plans were created for 9 patients with endometrial cancer undergoing WPRT. The dose distribution of planning target volume (PTV), organs at risk (OARs), and normal tissue (NT) were compared. The monitor units (MUs) and treatment delivery time were also evaluated. For each VMAT-CDR plan, a dry Run was performed to assess the dosimetric accuracy with MatriXX from IBA. Results: Compared with IMRT, the VMAT-CDR plans delivered a slightly greater V20 of the bowel, bladder, pelvis bone, and NT, but significantly decreased the dose to the high-dose region of the rectum and pelvis bone. The MUs Decreased from 1105 with IMRT to 628 with VMAT-CDR. The delivery time also decreased from 9.5 to 3.2 minutes. The average gamma pass rate was 95.6% at the 3%/3 mm criteria with MatriXX pretreatment verification for 9 patients. Conclusion: VMAT-CDR can achieve comparable plan quality with significant shorter delivery time and smaller number of MUs compared with IMRT for patients with endometrial cancer undergoing WPRT. It can be accurately delivered and be an alternative to IMRT on the linear accelerator without VDR capability. This work is supported by the grant project, National Natural; Science Foundation of China (No. 81071237)

  19. TCERG1 Regulates Alternative Splicing of the Bcl-x Gene by Modulating the Rate of RNA Polymerase II Transcription

    PubMed Central

    Montes, Marta; Cloutier, Alexandre; Sánchez-Hernández, Noemí; Michelle, Laetitia; Lemieux, Bruno; Blanchette, Marco; Hernández-Munain, Cristina; Chabot, Benoit

    2012-01-01

    Complex functional coupling exists between transcriptional elongation and pre-mRNA alternative splicing. Pausing sites and changes in the rate of transcription by RNA polymerase II (RNAPII) may therefore have fundamental impacts in the regulation of alternative splicing. Here, we show that the elongation and splicing-related factor TCERG1 regulates alternative splicing of the apoptosis gene Bcl-x in a promoter-dependent manner. TCERG1 promotes the splicing of the short isoform of Bcl-x (Bcl-xs) through the SB1 regulatory element located in the first half of exon 2. Consistent with these results, we show that TCERG1 associates with the Bcl-x pre-mRNA. A transcription profile analysis revealed that the RNA sequences required for the effect of TCERG1 on Bcl-x alternative splicing coincide with a putative polymerase pause site. Furthermore, TCERG1 modifies the impact of a slow polymerase on Bcl-x alternative splicing. In support of a role for an elongation mechanism in the transcriptional control of Bcl-x alternative splicing, we found that TCERG1 modifies the amount of pre-mRNAs generated at distal regions of the endogenous Bcl-x. Most importantly, TCERG1 affects the rate of RNAPII transcription of endogenous human Bcl-x. We propose that TCERG1 modulates the elongation rate of RNAPII to relieve pausing, thereby activating the proapoptotic Bcl-xS 5′ splice site. PMID:22158966

  20. Atomizing characteristics of swirl can combustor modules with swirl blast fuel injectors. [in terms of NOX emission rate

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1980-01-01

    Cold flow atomization tests of several different designs of swirl can combustor modules were conducted in a 7.6 cm diameter duct at airflow rates (per unit area) of 7.3 to 25.7 g/sq cm sec and water flow rates of 6.3 to 18.9 g/sec. The effect of air and water flow rates on the mean drop size of water sprays produced with the swirl blast fuel injectors were determined. Also, from these data it was possible to determine the effect of design modifications on the atomizing performance of various fuel injector and air swirler configurations. The trend in atomizing performance, as based on the mean drop size, was then compared with the trends in the production of nitrogen oxides obtained in combustion studues with the same swirl can combustors. It was found that the fuel injector design that gave the best combustor performance in terms of a low NOx emission index also gave the best atomizing performance as characterized by a spray of relatively small mean drop diameter. It was also demonstrated that at constant inlet air stream momentum the nitrogen oxides emission index was found to vary inversely with the square of the mean drop diameter of the spray produced by the different swirl blast fuel injectors. Test conditions were inlet air static pressures of 100,000 to 200,000 N/sq m at an inlet air temperature of 293 K.

  1. SSRI enhances sensitivity to background outcomes and modulates response rates: A randomized double blind study of instrumental action and depression.

    PubMed

    Msetfi, Rachel M; Kumar, Poornima; Harmer, Catherine J; Murphy, Robin A

    2016-05-01

    Serotonin reuptake inhibitors (SSRIs) have immediate effects on synaptic levels of serotonin but their therapeutic effects are often delayed. This delay has been suggested to reflect time required for new learning and therefore that SSRIs might be having effects on the learning process. We examined the effects of elevating serotonin levels, through short-term SSRI administration (escitalopram), on learning about perceptions of instrumental control. A randomised double blind procedure was used to allocate healthy people, categorised as mildly depressed (high BDI⩾10: n=76) or not depressed (low BDI⩽5: n=78) to either a drug (escitalopram, 10mg/7days) or placebo control group. Following treatment, participants were trained with a simple task that involved learning the effectiveness of an instrumental action (key press) and the background context at eliciting an outcome (auditory cue) where there was no programmed contingency. The effects of the drug were (i) to moderate response rates and (ii) to enhance sensitivity to the background or context rate of occurrence of the outcome. These findings suggest that serotonin modulates learning about the long-term rate of outcomes, which supports perception of instrumental control, and that this may provide a clue to the mechanism for supporting the development of the therapeutic effects of the drug. PMID:26976091

  2. Modulation of the effects of alveolar macrophages on lung fibroblast collagen production rate

    SciTech Connect

    Clark, J.G.; Greenberg, J.

    1987-01-01

    Alveolar macrophages (AM) may function as effector cells that can either stimulate or inhibit lung fibroblast collagen production. However, conditions that determine the predominant effect of AM on fibroblasts are not well understood. To delineate factors that modulate the effects of AM on lung fibroblasts, we studied the interaction of AM products and fibroblasts in vitro. The AM were obtained by bronchoalveolar lavage of hamsters with bleomycin-induced pulmonary fibrosis. Conditioned medium (CM) from the AM cultures was incubated in varying amounts with lung fibroblast (IMR-90) cultures. After metabolic labeling with (/sup 3/H)proline, fibroblast collagen production based on procollagen-specific radioactivity was determined. Macrophage CM in concentrations greater than 5% suppressed collagen production, an event attributed to the macrophage-derived suppressive factor that we have previously characterized. Macrophages were also determined to produce PGE2 in culture. Authentic PGE2 at concentrations found in CM was found to suppress fibroblast collagen production, indicating that AM-derived PGE2 contributes to the suppressive activity in CM. To examine possible stimulatory factors in CM, the fibroblasts were preincubated with indomethacin. This approach was based on our previous observation that AM-derived suppressive factor increases endogenous fibroblast PGE2 and that its activity can be blocked by indomethacin. Macrophage CM in a concentration of 20% did not suppress the collagen production of indomethacin-treated fibroblasts. However, CM concentrations of 5 and 10% increased collagen production (173 and 143% of control values, respectively), indicating the presence of stimulatory factor(s) in macrophage-conditioned medium.

  3. Rating Movies and Rating the Raters Who Rate Them.

    PubMed

    Zhou, Hua; Lange, Kenneth

    2009-11-01

    The movie distribution company Netflix has generated considerable buzz in the statistics community by offering a million dollar prize for improvements to its movie rating system. Among the statisticians and computer scientists who have disclosed their techniques, the emphasis has been on machine learning approaches. This article has the modest goal of discussing a simple model for movie rating and other forms of democratic rating. Because the model involves a large number of parameters, it is nontrivial to carry out maximum likelihood estimation. Here we derive a straightforward EM algorithm from the perspective of the more general MM algorithm. The algorithm is capable of finding the global maximum on a likelihood landscape littered with inferior modes. We apply two variants of the model to a dataset from the MovieLens archive and compare their results. Our model identifies quirky raters, redefines the raw rankings, and permits imputation of missing ratings. The model is intended to stimulate discussion and development of better theory rather than to win the prize. It has the added benefit of introducing readers to some of the issues connected with analyzing high-dimensional data. PMID:20802818

  4. Rating Movies and Rating the Raters Who Rate Them

    PubMed Central

    Zhou, Hua; Lange, Kenneth

    2010-01-01

    The movie distribution company Netflix has generated considerable buzz in the statistics community by offering a million dollar prize for improvements to its movie rating system. Among the statisticians and computer scientists who have disclosed their techniques, the emphasis has been on machine learning approaches. This article has the modest goal of discussing a simple model for movie rating and other forms of democratic rating. Because the model involves a large number of parameters, it is nontrivial to carry out maximum likelihood estimation. Here we derive a straightforward EM algorithm from the perspective of the more general MM algorithm. The algorithm is capable of finding the global maximum on a likelihood landscape littered with inferior modes. We apply two variants of the model to a dataset from the MovieLens archive and compare their results. Our model identifies quirky raters, redefines the raw rankings, and permits imputation of missing ratings. The model is intended to stimulate discussion and development of better theory rather than to win the prize. It has the added benefit of introducing readers to some of the issues connected with analyzing high-dimensional data. PMID:20802818

  5. Pretreatment H2 receptor antagonists that differ in P450 modulation activity: comparative effects on paclitaxel clearance rates and neutropenia.

    PubMed

    Slichenmyer, W J; Donehower, R C; Chen, T L; Bowling, M K; McGuire, W P; Rowinsky, E K

    1995-01-01

    Histamine-2 receptor antagonists (H2RAs) are principal components of the premedication regimen used to prevent major hypersensitivity reactions in patients receiving paclitaxel. Several different H2RAs, including cimetidine, ranitidine and famotidine, have been used in clinical trials of paclitaxel, as well as by clinicians in different geographic regions and hospitals primarily because of differences in the availability of the various H2RAs. However, H2RAs have highly variable cytochrome P450-modulating capabilities, and the P450 system appears to play a major role in paclitaxel metabolism and disposition. Therefore, the use of different H2RAs may result in different pharmacologic, toxicologic and antitumor profiles due to differential effects on paclitaxel metabolism. This study evaluated whether cimetidine and famotidine, which possess disparate P450-modulating capabilities, differentially affect paclitaxel clearance rates and the agent's principal toxicity, neutropenia. Women with advanced, platinum-refractory ovarian carcinoma received two courses of treatment with 135 mg/m2 paclitaxel over 24 h while participating in the National Cancer Institute's Treatment Referral Center Protocol. A crossover design was employed in which consecutive patients received either 300 mg cimetidine i.v. or 20 mg famotidine i.v. before their first course of paclitaxel and the alternate H2RA before their second course. In order to evaluate the differential effects of cimetidine and famotidine on pertinent pharmacologic and toxicologic parameters in the same individual, paclitaxel concentrations at steady-state (Css), paclitaxel clearance rates, and absolute neutrophil counts (ANCs) were obtained during both courses. Paclitaxel Css values were not significantly different in individual patients when either cimetidine or famotidine preceded paclitaxel (p = 0.16). Mean paclitaxel clearance rates were 271 and 243 ml/min per m2 following cimetidine and famotidine, respectively. These

  6. A specialized layering module for high rep-rate production of free standing HiPER targets

    NASA Astrophysics Data System (ADS)

    Aleksandrova, I.; Belolipetskiy, A.; Koresheva, E.; Koshelev, E.; Malinina, E.; Mitina, L.; Panina, L.; Chtcherbakov, V.; Tolley, M.; Edwards, C.; Spindloe, C.

    2013-11-01

    The target supply system is a necessary requirement for fueling a future energy source (reactor) with a high rep-rate: 0.1-10 Hz. At the Lebedev Physical Institute (LPI), significant progress has been made in the technology based on rapid fuel layering inside moving free-standing targets that is referred to as FST (Free-Standing Targets) layering method. This allows creating a continuously or repeatable operating FST supply system, the development of which at LPI dates back to 1980s. Therefore, the LPI is in the position to propose the use of FST technologies for HiPER facility operation (conceptual design and prototype realization). Here we report on our most significant results on the development of a specialized layering module prototype for repeatable formation of HiPER free-standing cryogenic targets.

  7. Insights into the hierarchical structure and digestion rate of alkali-modulated starches with different amylose contents.

    PubMed

    Qiao, Dongling; Yu, Long; Liu, Hongsheng; Zou, Wei; Xie, Fengwei; Simon, George; Petinakis, Eustathios; Shen, Zhiqi; Chen, Ling

    2016-06-25

    Combined analytical techniques were used to explore the effects of alkali treatment on the multi-scale structure and digestion behavior of starches with different amylose/amylopectin ratios. Alkali treatment disrupted the amorphous matrix, and partial lamellae and crystallites, which weakened starch molecular packing and eventually enhanced the susceptibility of starch to alkali. Stronger alkali treatment (0.5% w/w) made this effect more prominent and even transformed the dual-phase digestion of starch into a triple-phase pattern. Compared with high-amylose starch, regular maize starch, which possesses some unique structure characteristics typically as pores and crystallite weak points, showed evident changes of hierarchical structure and in digestion rate. Thus, alkali treatment has been demonstrated as a simple method to modulate starch hierarchical structure and thus to realize the rational development of starch-based food products with desired digestibility. PMID:27083818

  8. Study of radial growth rate and size control of silicon nanocrystals in square-wave-modulated silane plasmas

    SciTech Connect

    Nguyen-Tran, Th.; Roca i Cabarrocas, P.; Patriarche, G.

    2007-09-10

    The growth of silicon nanocrystals in high pressure and high dilution silane plasmas is investigated by using the temporal evolution of the self-bias on the radio frequency electrode and transmission electron microscopy. A square-wave-modulated plasma was used in order to control the growth of monodispersed nanoparticles with sizes smaller than 12 nm. To this end, the plasma on time was kept below 1 s. The radial growth rate of nanoparticles was varied in the range from 7.5 to 75 nm/s by changing silane partial pressure. Nanoparticles grown in silane-helium discharges have been found amorphous while they are crystalline in silane-hydrogen-argon discharges. Surprisingly, the crystallization in the gaseous phase does not depend on how slow or fast the particles grow but on the presence of atomic hydrogen.

  9. Modulation of lead-induced performance deficit in children by varying signal rate in a serial choice reaction task

    SciTech Connect

    Winneke, G.; Brockhaus, A.; Collet, W.; Kraemer, U. )

    1989-11-01

    Evidence is presented showing that serial choice reaction performance is disrupted at low blood lead levels (PbB), and that parametric variation of task characteristics modulates the degree of disruption. This evidence is based on two independent studies in 6- to 9-year-old children living in two lead smelter areas in the cities of Nordenham (N = 114) and Stolberg (N = 109) in West Germany. Average PbB was 8.2 micrograms/100 ml (4.4-23.8 micrograms/100 ml) in the Nordenham sample and 7.4 micrograms/100 ml (4.2-18.0 micrograms/100 ml) in the Stolberg sample. Serial choice reaction performance was assessed by means of the Vienna reaction device in which a random sequence of light and tone signals has to be answered by pressing appropriate response buttons. Correct (hits) and false responses (errors) were evaluated as performance measures, and signal rate was varied in order to achieve easy and difficult task conditions. Exposure-related performance deficit was more pronounced for errors than for hits, more clearcut for high than for low signal rates, and proved significant in both studies after correction for confounding using confounder models of different complexities. Some features of the observed deficit resemble clinical observations in children presenting with attention deficit disorder.

  10. Grapevine Rootstocks Differentially Affect the Rate of Ripening and Modulate Auxin-Related Genes in Cabernet Sauvignon Berries.

    PubMed

    Corso, Massimiliano; Vannozzi, Alessandro; Ziliotto, Fiorenza; Zouine, Mohamed; Maza, Elie; Nicolato, Tommaso; Vitulo, Nicola; Meggio, Franco; Valle, Giorgio; Bouzayen, Mondher; Müller, Maren; Munné-Bosch, Sergi; Lucchin, Margherita; Bonghi, Claudio

    2016-01-01

    In modern viticulture, grafting commercial grapevine varieties on interspecific rootstocks is a common practice required for conferring resistance to many biotic and abiotic stresses. Nevertheless, the use of rootstocks to gain these essential traits is also known to impact grape berry development and quality, although the underlying mechanisms are still poorly understood. In grape berries, the onset of ripening (véraison) is regulated by a complex network of mobile signals including hormones such as auxins, ethylene, abscisic acid, and brassinosteroids. Recently, a new rootstock, designated M4, was selected based on its enhanced tolerance to water stress and medium vigor. This study investigates the effect of M4 on Cabernet Sauvignon (CS) berry development in comparison to the commercial 1103P rootstock. Physical and biochemical parameters showed that the ripening rate of CS berries is faster when grafted onto M4. A multifactorial analysis performed on mRNA-Seq data obtained from skin and pulp of berries grown in both graft combinations revealed that genes controlling auxin action (ARF and Aux/IAA) represent one of main categories affected by the rootstock genotype. Considering that the level of auxin tightly regulates the transcription of these genes, we investigated the behavior of the main gene families involved in auxin biosynthesis and conjugation. Molecular and biochemical analyses confirmed a link between the rate of berry development and the modulation of auxin metabolism. Moreover, the data indicate that this phenomenon appears to be particularly pronounced in skin tissue in comparison to the flesh. PMID:26904046

  11. Grapevine Rootstocks Differentially Affect the Rate of Ripening and Modulate Auxin-Related Genes in Cabernet Sauvignon Berries

    PubMed Central

    Corso, Massimiliano; Vannozzi, Alessandro; Ziliotto, Fiorenza; Zouine, Mohamed; Maza, Elie; Nicolato, Tommaso; Vitulo, Nicola; Meggio, Franco; Valle, Giorgio; Bouzayen, Mondher; Müller, Maren; Munné-Bosch, Sergi; Lucchin, Margherita; Bonghi, Claudio

    2016-01-01

    In modern viticulture, grafting commercial grapevine varieties on interspecific rootstocks is a common practice required for conferring resistance to many biotic and abiotic stresses. Nevertheless, the use of rootstocks to gain these essential traits is also known to impact grape berry development and quality, although the underlying mechanisms are still poorly understood. In grape berries, the onset of ripening (véraison) is regulated by a complex network of mobile signals including hormones such as auxins, ethylene, abscisic acid, and brassinosteroids. Recently, a new rootstock, designated M4, was selected based on its enhanced tolerance to water stress and medium vigor. This study investigates the effect of M4 on Cabernet Sauvignon (CS) berry development in comparison to the commercial 1103P rootstock. Physical and biochemical parameters showed that the ripening rate of CS berries is faster when grafted onto M4. A multifactorial analysis performed on mRNA-Seq data obtained from skin and pulp of berries grown in both graft combinations revealed that genes controlling auxin action (ARF and Aux/IAA) represent one of main categories affected by the rootstock genotype. Considering that the level of auxin tightly regulates the transcription of these genes, we investigated the behavior of the main gene families involved in auxin biosynthesis and conjugation. Molecular and biochemical analyses confirmed a link between the rate of berry development and the modulation of auxin metabolism. Moreover, the data indicate that this phenomenon appears to be particularly pronounced in skin tissue in comparison to the flesh. PMID:26904046

  12. Rotation Modulations and Distributions of the Flare Occurrence Rates on the Surface of Five UV Ceti Type Stars

    NASA Astrophysics Data System (ADS)

    Dal, Hasan Ali; Evren, Serdar

    2011-04-01

    In this study, we considered stellar spots, stellar flares, and also the relation between these two magnetic proccesses that take place on UV Cet stars. In addition, the hypothesis about slow flares described by Gurzadyan (1986 Ap&SS, 125, 127) was investigated. All of these discussions were based on the results of three years of observations of UV Cet-type stars: AD Leo, EV Lac, V1005 Ori, EQ Peg, and V1054 Oph. First of all, the results show that stellar spot activity occurs on the stellar surface of EV Lac, V1005 Ori, and EQ Peg, while AD Leo does not show any short-term variability and V1054 Oph does not exhibit any variability. We report on new ephemerides for EV Lac, V1005 Ori, and EQ Peg, obtained from time-series analyses. The phases, computed at intervals of 0.10 phase length, where the mean flare occurence rates to obtain maximum amplitude; also, the phases of rotational modulation were compared in order to investigate whether there is any longitudinal relation between stellar flares and spots. Although the results show that flare events are related with spotted areas on stellar surfaces during some of the observing seasons, we did not find any clear correlation among them. Finally, it was tested whether slow flares are fast flares occurring on the opposite side of the stars according to the direction of the observers, as mentioned in a hypothesis developed by Gurzadyan (1986). The flare occurence rates reveal that both slow and fast flares can occur in any rotational phases. The flare occurence rates of both fast and slow flares vary in the same way along the longitudes for all program stars. These results are not expected based on the case mentioned in the hypothesis.

  13. Changes in emotional state modulate neuronal firing rates of human speech motor cortex: a case study in long-term recording.

    PubMed

    Kennedy, Philip

    2011-10-01

    In many brain areas, modulations in neuronal firing rates are thought to code information. However, in electrophysiological recording experiments, especially recordings in human patients, the type of information that is coded by a neuron's discharge patterns is often not known, or difficult to determine. From our long experience with chronic recordings in humans, we have come to suspect that such unexplained modulations in firing rates are often due to state changes in the subject. We here present two case studies, with extensive data in one subject to illustrate the point that a change in the subject's emotions, such as sudden fear, surprise, or happiness, may trigger substantial changes in firing rates. PMID:21967282

  14. Fertility Clinic Success Rates

    MedlinePlus

    ... 2013 Assisted Reproductive Technology Fertility Clinic Success Rates Report Recommend on Facebook Tweet Share Compartir 2013 ART Fertility Clinic Success Rates Report [PDF - 1MB] Bookmarks and thumbnails are available within ...

  15. Glomerular filtration rate

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  16. Target Heart Rate Calculator

    MedlinePlus

    ... My Saved Articles » My ACS » + - Text Size Target Heart Rate Calculator Compute your best workout Enter your age ... is your age? years. How to Check Your Heart Rate Right after you stop exercising, take your pulse: ...

  17. Handbook of noise ratings

    NASA Technical Reports Server (NTRS)

    Pearsons, K. S.; Bennett, R. L.

    1974-01-01

    The handbook was compiled to provide information in a concise form, describing the multitude of noise rating schemes. It is hoped that by describing the noise rating methods in a single volume the user will have better access to the definitions, application and calculation procedures of the current noise rating methods.

  18. SU-E-T-185: Feasibility Study of Dose Rate Modulated Arc Therapy (DrMAT) for Lung SBRT

    SciTech Connect

    KO, Y; Cho, B; Yi, B; Kwak, J; Song, S; Je, H; Ahn, S; Noh, Y

    2014-06-01

    Purpose: To show the feasibility of clinical application of DrMAT for SBRT in lung cancer patients. DrMAT is a form of dynamic conformal arc therapy where MLC segments and dose rates are controlled through simple field weight optimization. Methods: To show feasibility a new treatment plan was created based on the CT of SBRT lung cancer patients. Static plans with 33 fields are made, which have 11deg in between each field and are acquired rotating gantry angle from 180deg to 188deg in CCW direction, total 352deg is rotated. MLC maintained static aperture for each field. To optimize 33 individual fields, field weight was adjusted accordingly using weight optimization algorithm. Keeping weights and MU of static plan, static MLC aperture was converted to multiple arc segments. Arc plan could be created with the fields in the intervals of 11deg. Static MLC should be converted to arc segment MLC. Dynamic conformal arc therapy plan consists of 33 arc fields, is converted to one dose rate modulated arc therapy (DrMAT) plan. DrMAT plan consists of 166 control points which becomes a single arc plan that changes the shape of MLC for every 2.2deg. The resulting DrMAT plan is not an inverse plan it is a simple form of dynamic conformal arc plan using field weight obtained from static plan. This is compared and evaluated with the VMAT plan. Results: DrMAT and VMAT plans have been compared based on the RTOG1021. Both DrMAT and VMAT plans satisfy 100% irradiation to 95% of PTV and critical organs did not exceed dose limit suggested in RTOG1021. DrMAT plan is almost similar with VMAT plan in Result. Conclusion: Field weight optimization method did not show better Resultcompared to VMAT optimization. However, considering simplicity, DrMAT satisfies the condition in RTOG1021. Therefore clinical application of DrMAT is feasible.

  19. Rate theories for biologists

    PubMed Central

    Zhou, Huan-Xiang

    2012-01-01

    Some of the rate theories that are most useful for modeling biological processes are reviewed. By delving into some of the details and subtleties in the development of the theories, the review will hopefully help the reader gain a more than superficial perspective. Examples are presented to illustrate how rate theories can be used to generate insight at the microscopic level into biomolecular behaviors. Attempt is made to clear up a number of misconceptions in the literature regarding popular rate theories, including the appearance of Planck’s constant in the transition-state theory and the Smoluchowski result as an upper limit for protein-protein and protein-DNA association rate constants. Future work in combining the implementation of rate theories through computer simulations with experimental probes of rate processes, and in modeling effects of intracellular environments so theories can be used for generating rate constants for systems biology studies is particularly exciting. PMID:20691138

  20. Time Modulation of the K-Shell Electron Capture Decay Rates of H-like Heavy Ions at GSI Experiments

    SciTech Connect

    Ivanov, A. N.; Kienle, P.

    2009-08-07

    According to experimental data at GSI, the rates of the number of daughter ions, produced by the nuclear K shell electron capture decays of the H-like heavy ions with one electron in the K shell, such as {sup 140}Pr{sup 58+}, {sup 142}Pm{sup 60+}, and {sup 122}I{sup 52+}, are modulated in time with periods T{sub EC} of the order of a few seconds, obeying an A scaling T{sub EC}=A/20 s, where A is the mass number of the mother nuclei, and with amplitudes a{sub d}{sup EC}approx0.21. We show that these data can be explained in terms of the interference of two massive neutrino mass eigenstates. The appearance of the interference term is due to overlap of massive neutrino mass eigenstate energies and of the wave functions of the daughter ions in two-body decay channels, caused by the energy and momentum uncertainties introduced by time differential detection of the daughter ions in GSI experiments.

  1. Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus.

    PubMed

    Viblanc, Vincent A; Smith, Andrew D; Gineste, Benoit; Kauffmann, Marion; Groscolas, René

    2015-06-01

    'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds. PMID:25883375

  2. Observed Barium Emission Rates

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.; Wescott, E. M.; Hallinan, T. J.

    1993-01-01

    The barium releases from the CRRES satellite have provided an opportunity for verifying theoretically calculated barium ion and neutral emission rates. Spectra of the five Caribbean releases in the summer of 1991 were taken with a spectrograph on board a U.S. Air Force jet aircraft. Because the line of sight release densities are not known, only relative rates could be obtained. The observed relative rates agree well with the theoretically calculated rates and, together with other observations, confirm the earlier detailed theoretical emission rates. The calculated emission rates can thus with good accuracy be used with photometric observations. It has been postulated that charge exchange between neutral barium and oxygen ions represents a significant source for ionization. If so. it should be associated with emissions at 4957.15 A and 5013.00 A, but these emissions were not detected.

  3. Utility of a Novel Biofeedback Device for Within-Breath Modulation of Heart Rate in Rats: A Quantitative Comparison of Vagus Nerve vs. Right Atrial Pacing.

    PubMed

    O'Callaghan, Erin L; Chauhan, Ashok S; Zhao, Le; Lataro, Renata M; Salgado, Helio C; Nogaret, Alain; Paton, Julian F R

    2016-01-01

    In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG) that uses cutting edge analog circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA), which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (HRV) (an indicator of cardiac health), we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anesthetized, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i) heart rate modulation in any phase of the respiratory cycle, (ii) control of the magnitude of heart rate modulation, and (iii) instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA. PMID:26869940

  4. Utility of a Novel Biofeedback Device for Within-Breath Modulation of Heart Rate in Rats: A Quantitative Comparison of Vagus Nerve vs. Right Atrial Pacing

    PubMed Central

    O'Callaghan, Erin L.; Chauhan, Ashok S.; Zhao, Le; Lataro, Renata M.; Salgado, Helio C.; Nogaret, Alain; Paton, Julian F. R.

    2016-01-01

    In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG) that uses cutting edge analog circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA), which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (HRV) (an indicator of cardiac health), we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anesthetized, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i) heart rate modulation in any phase of the respiratory cycle, (ii) control of the magnitude of heart rate modulation, and (iii) instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA. PMID:26869940

  5. High Rate Digital Demodulator ASIC

    NASA Technical Reports Server (NTRS)

    Ghuman, Parminder; Sheikh, Salman; Koubek, Steve; Hoy, Scott; Gray, Andrew

    1998-01-01

    The architecture of High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation in other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA's Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an over-view of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.

  6. Metabolic rate measurement system

    NASA Technical Reports Server (NTRS)

    Koester, K.; Crosier, W.

    1980-01-01

    The Metabolic Rate Measurement System (MRMS) is an uncomplicated and accurate apparatus for measuring oxygen consumption and carbon dioxide production of a test subject. From this one can determine the subject's metabolic rate for a variety of conditions, such as resting or light exercise. MRMS utilizes an LSI/11-03 microcomputer to monitor and control the experimental apparatus.

  7. Applications of Reaction Rate

    ERIC Educational Resources Information Center

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  8. Controlled Rate Cooling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controlled-rate cooling is one of several techniques available for the long-term storage of plants in liquid nitrogen. In this technique samples are slowly cooled to an intermediate temperature and then plunged in liquid nitrogen. Controlled rate cooling is based on osmotic regulation of cell conte...

  9. Scaling metabolic rate fluctuations.

    PubMed

    Labra, Fabio A; Marquet, Pablo A; Bozinovic, Francisco

    2007-06-26

    Complex ecological and economic systems show fluctuations in macroscopic quantities such as exchange rates, size of companies or populations that follow non-Gaussian tent-shaped probability distributions of growth rates with power-law decay, which suggests that fluctuations in complex systems may be governed by universal mechanisms, independent of particular details and idiosyncrasies. We propose here that metabolic rate within individual organisms may be considered as an example of an emergent property of a complex system and test the hypothesis that the probability distribution of fluctuations in the metabolic rate of individuals has a "universal" form regardless of body size or taxonomic affiliation. We examined data from 71 individuals belonging to 25 vertebrate species (birds, mammals, and lizards). We report three main results. First, for all these individuals and species, the distribution of metabolic rate fluctuations follows a tent-shaped distribution with power-law decay. Second, the standard deviation of metabolic rate fluctuations decays as a power-law function of both average metabolic rate and body mass, with exponents -0.352 and -1/4 respectively. Finally, we find that the distributions of metabolic rate fluctuations for different organisms can all be rescaled to a single parent distribution, supporting the existence of general principles underlying the structure and functioning of individual organisms. PMID:17578913

  10. Extended rate equations

    SciTech Connect

    Shore, B.W.

    1981-01-30

    The equations of motion are discussed which describe time dependent population flows in an N-level system, reviewing the relationship between incoherent (rate) equations, coherent (Schrodinger) equations, and more general partially coherent (Bloch) equations. Approximations are discussed which replace the elaborate Bloch equations by simpler rate equations whose coefficients incorporate long-time consequences of coherence.

  11. Interest rates mapping

    NASA Astrophysics Data System (ADS)

    Kanevski, M.; Maignan, M.; Pozdnoukhov, A.; Timonin, V.

    2008-06-01

    The present study deals with the analysis and mapping of Swiss franc interest rates. Interest rates depend on time and maturity, defining term structure of the interest rate curves (IRC). In the present study IRC are considered in a two-dimensional feature space-time and maturity. Exploratory data analysis includes a variety of tools widely used in econophysics and geostatistics. Geostatistical models and machine learning algorithms (multilayer perceptron and Support Vector Machines) were applied to produce interest rate maps. IR maps can be used for the visualisation and pattern perception purposes, to develop and to explore economical hypotheses, to produce dynamic asset-liability simulations and for financial risk assessments. The feasibility of an application of interest rates mapping approach for the IRC forecasting is considered as well.

  12. Optimal firing rate estimation

    NASA Technical Reports Server (NTRS)

    Paulin, M. G.; Hoffman, L. F.

    2001-01-01

    We define a measure for evaluating the quality of a predictive model of the behavior of a spiking neuron. This measure, information gain per spike (Is), indicates how much more information is provided by the model than if the prediction were made by specifying the neuron's average firing rate over the same time period. We apply a maximum Is criterion to optimize the performance of Gaussian smoothing filters for estimating neural firing rates. With data from bullfrog vestibular semicircular canal neurons and data from simulated integrate-and-fire neurons, the optimal bandwidth for firing rate estimation is typically similar to the average firing rate. Precise timing and average rate models are limiting cases that perform poorly. We estimate that bullfrog semicircular canal sensory neurons transmit in the order of 1 bit of stimulus-related information per spike.

  13. Mutation rates as adaptations.

    PubMed

    Maley, C

    1997-06-01

    In order to better understand life, it is helpful to look beyond the envelop of life as we know it. A simple model of coevolution was implemented with the addition of a gene for the mutation rate of the individual. This allowed the mutation rate itself to evolve in a lineage. The model shows that when the individuals interact in a sort of zero-sum game, the lineages maintain relatively high mutation rates. However, when individuals engage in interactions that have greater consequences for one individual in the interaction than the other, lineages tend to evolve relatively low mutation rates. This model suggests that one possible cause for differential mutation rates across genes may be the coevolutionary pressure of the various forms of interactions with other genes. PMID:9219670

  14. Changes in luminal flow rate modulate basal and bradykinin-stimulated cell [Ca2+] in aortic endothelium.

    PubMed

    Oliver, J A; Chase, H S

    1992-04-01

    Hemodynamic forces influence many endothelial cell functions. The coupling between hemodynamic forces and cell function could be mediated by mechano-sensitive ion channels present in the plasma membrane of endothelial cells. Because one of these channels is permeable to Ca2+, we tested whether hemodynamic forces influence endothelial cell Ca2+ ([Ca2+]i). Bovine aortic endothelial cells were grown inside cylindrical glass tubes, loaded with fura-2, and perfused at different pressures and flow rates on the stage of a fluorescence microscope. Decreasing flow from 110 to 2 ml.min-1 raised [Ca2+]i from 57 +/- 11 to 186 +/- 29 nM (mean +/- SEM, p less than 0.01) by increasing the entry of extracellular Ca2+ into the cytoplasm. Increasing flow from 2 to 110 ml.min-1 transiently decreased [Ca2+]i from 62 +/- 3 to 33 +/- 5 nM (p less than 0.01) apparently due to reduced Ca2+ entry and concomitant extrusion by the plasma membrane Ca(2+)-ATPase. The rise in [Ca2+]i induced by bradykinin was magnified during a decrease in flow; in control cells, 10(-7) M bradykinin increased [Ca2+]i by 162 +/- 26 nM, whereas [Ca2+]i increased 350 +/- 67 nM (p less than 0.05) in cells previously exposed to 110 ml.min-1. These observations suggest that flow-induced changes in [Ca2+]i might be a signal-transduction mechanism for endothelial functions responsive to hemodynamic forces and may also modulate the magnitude of hormonally mediated increases in [Ca2+]i. PMID:1313820

  15. Encoding of the amplitude modulation of pulsatile electrical stimulation in the feline cochlear nucleus by neurons in the inferior colliculus; effects of stimulus pulse rate

    NASA Astrophysics Data System (ADS)

    McCreery, Douglas; Han, Martin; Pikov, Victor; Yadav, Kamal; Pannu, Satinderpall

    2013-10-01

    Objectives. Persons without a functional auditory nerve cannot benefit from cochlear implants, but some hearing can be restored by an auditory brainstem implant (ABI) with stimulating electrodes implanted on the surface of the cochlear nucleus (CN). Most users benefit from their ABI, but speech recognition tends to be poorer than for users of cochlear implants. Psychophysical studies suggest that poor modulation detection may contribute to the limited performance of ABI users. In a cat model, we determined how the pulse rate of the electrical stimulus applied within or on the CN affects temporal and rate encoding of amplitude modulation (AM) by neurons in the central nucleus of the inferior colliculus (ICC). Approach. Stimulating microelectrodes were implanted chronically in and on the cats' CN, and multi-site recording microelectrodes were implanted chronically into the ICC. Encoding of AM pulse trains by neurons in the ICC was characterized as vector strength (VS), the synchrony of neural activity with the AM, and as the mean rate of neuronal action potentials (neuronal spike rate (NSR)). Main results. For intranuclear microstimulation, encoding of AM as VS was up to 3 dB greater when stimulus pulse rate was increased from 250 to 500 pps, but only for neuronal units with low best acoustic frequencies, and when the electrical stimulation was modulated at low frequencies (10-20 Hz). For stimulation on the surface of the CN, VS was similar at 250 and 500 pps, and the dynamic range of the VS was reduced for pulse rates greater than 250 pps. Modulation depth was encoded strongly as VS when the maximum stimulus amplitude was held constant across a range of modulation depth. This ‘constant maximum’ protocol allows enhancement of modulation depth while preserving overall dynamic range. However, modulation depth was not encoded as strongly as NSR. Significance. The findings have implications for improved sound processors for present and future ABIs. The performance of

  16. Growth rates made easy.

    PubMed

    Hall, Barry G; Acar, Hande; Nandipati, Anna; Barlow, Miriam

    2014-01-01

    In the 1960s-1980s, determination of bacterial growth rates was an important tool in microbial genetics, biochemistry, molecular biology, and microbial physiology. The exciting technical developments of the 1990s and the 2000s eclipsed that tool; as a result, many investigators today lack experience with growth rate measurements. Recently, investigators in a number of areas have started to use measurements of bacterial growth rates for a variety of purposes. Those measurements have been greatly facilitated by the availability of microwell plate readers that permit the simultaneous measurements on up to 384 different cultures. Only the exponential (logarithmic) portions of the resulting growth curves are useful for determining growth rates, and manual determination of that portion and calculation of growth rates can be tedious for high-throughput purposes. Here, we introduce the program GrowthRates that uses plate reader output files to automatically determine the exponential portion of the curve and to automatically calculate the growth rate, the maximum culture density, and the duration of the growth lag phase. GrowthRates is freely available for Macintosh, Windows, and Linux. We discuss the effects of culture volume, the classical bacterial growth curve, and the differences between determinations in rich media and minimal (mineral salts) media. This protocol covers calibration of the plate reader, growth of culture inocula for both rich and minimal media, and experimental setup. As a guide to reliability, we report typical day-to-day variation in growth rates and variation within experiments with respect to position of wells within the plates. PMID:24170494

  17. Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential

    PubMed Central

    Capel, Rebecca A.; Herring, Neil; Kalla, Manish; Yavari, Arash; Mirams, Gary R.; Douglas, Gillian; Bub, Gil; Channon, Keith; Paterson, David J.; Terrar, Derek A.; Burton, Rebecca-Ann B.

    2015-01-01

    Background Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. Objectives The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. Methods We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the “funny” current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1–30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). Results In mouse atria, spontaneous beating rate was significantly (P < .05) reduced (by 9% ± 3% and 15% ± 2% at 3 and 10 µM HCQ, n = 7). In guinea pig isolated SAN cells, HCQ conferred a significant reduction in spontaneous action potential firing rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. Conclusions We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If. PMID:26025323

  18. Burning Rate Emulator

    NASA Video Gallery

    The Burning Rate Emulator is a gas fuel investigation attempting to emulate the burning of solids to improve our understanding of materials''flammability over a wide range of conditions. The approa...

  19. The ratings game

    NASA Astrophysics Data System (ADS)

    Braben, Donald W.

    2009-04-01

    How sad to read a supposedly serious debate among distinguished physicists (February p19) about which combinations of the latest Research Assessment Exercise (RAE) ratings represent a university physics department's true strengths.

  20. National ART Success Rates

    MedlinePlus

    ... ART and Birth Defects ART and Autism 2013 Assisted Reproductive Technology National Summary Report Recommend on Facebook Tweet Share ... live-birth rate? [PDF - 1.37MB] Section 2: ART Cycles using fresh nondonor eggs or embryos What ...

  1. Rating the Risks.

    ERIC Educational Resources Information Center

    Slovic, Paul; And Others

    1979-01-01

    Explains how people arrive at personal hazard assessments. Explores why people overestimate some hazards and underestimate others. Examines risk ratings for activities and technologies such as nuclear power, motor vehicles, pesticides, and vaccinations. (MA)

  2. Heart Rate Monitor

    NASA Technical Reports Server (NTRS)

    1984-01-01

    In the mid 70's, NASA saw a need for a long term electrocardiographic electrode suitable for use on astronauts. Heart Rate Inc.'s insulated capacitive electrode is constructed of thin dielectric film applied to stainless steel surface, originally developed under a grant by Texas Technical University. HRI, Inc. was awarded NASA license and continued development of heart rate monitor for use on exercise machines for physical fitness and medical markets.

  3. Hydration rate of obsidian.

    PubMed

    Friedman, I; Long, W

    1976-01-30

    The hydration rates of 12 obsidian samples of different chemical compositions were measured at temperatures from 95 degrees to 245 degrees C. An expression relating hydration rate to temperature was derived for each sample. The SiO(2) content and refractive index are related to the hydration rate, as are the CaO, MgO, and original water contents. With this information it is possible to calculate the hydration rate of a sample from its silica content, refractive index, or chemical index and a knowledge of the effective temperature at which the hydration occurred. The effective hydration temperature can be either measured or approximated from weather records. Rates have been calculated by both methods, and the results show that weather records can give a good approximation to the true EHT, particularly in tropical and subtropical climates. If one determines the EHT by any of the methods suggested, and also measures or knows the rate of hydration of the particular obsidian used, it should be possible to carry out absolute dating to +/- 10 percent of the true age over periods as short as several years and as long as millions of years. PMID:17782901

  4. Heart Rate Monitors

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded Heart Rate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heart rate is used to control the work intensity on the VersaClimber using the heart rate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEART RATE monitors that are used wherever people exercise to accurately monitor their heart rate. Company is developing a talking heart rate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.

  5. Intensity-modulated radiation therapy for pancreatic and prostate cancer using pulsed low–dose rate delivery techniques

    SciTech Connect

    Li, Jie; Lang, Jinyi; Wang, Pei; Kang, Shengwei; Lin, Mu-han; Chen, Xiaoming; Chen, Fu; Guo, Ming; Chen, Lili; Ma, Chang-Ming Charlie

    2014-01-01

    Reirradiation of patients who were previously treated with radiotherapy is vastly challenging. Pulsed low–dose rate (PLDR) external beam radiotherapy has the potential to reduce normal tissue toxicities while providing significant tumor control for recurrent cancers. This work investigates treatment planning techniques for intensity-modulated radiation therapy (IMRT)-based PLDR treatment of various sites, including cases with pancreatic and prostate cancer. A total of 20 patients with clinical recurrence were selected for this study, including 10 cases with pancreatic cancer and 10 with prostate cancer. Large variations in the target volume were included to test the ability of IMRT using the existing treatment planning system and optimization algorithm to deliver uniform doses in individual gantry angles/fields for PLDR treatments. Treatment plans were generated with 10 gantry angles using the step-and-shoot IMRT delivery technique, which can be delivered in 3-minute intervals to achieve an effective low dose rate of 6.7 cGy/min. Instead of dose constraints on critical structures, ring structures were mainly used in PLDR-IMRT optimization. In this study, the PLDR-IMRT plans were compared with the PLDR-3-dimensional conformal radiation therapy (3DCRT) plans and the PLDR-RapidArc plans. For the 10 cases with pancreatic cancer that were investigated, the mean planning target volume (PTV) dose for each gantry angle in the PLDR-IMRT plans ranged from 17.6 to 22.4 cGy. The maximum doses ranged between 22.9 and 34.8 cGy. The minimum doses ranged from 8.2 to 17.5 cGy. For the 10 cases with prostate cancer that were investigated, the mean PTV doses for individual gantry angles ranged from 18.8 to 22.6 cGy. The maximum doses per gantry angle were between 24.0 and 34.7 cGy. The minimum doses per gantry angle ranged from 4.4 to 17.4 cGy. A significant reduction in the organ at risk (OAR) dose was observed with the PLDR-IMRT plan when compared with that using the PLDR-3DCRT

  6. Turnover Rate of NS3 Proteins Modulates Bluetongue Virus Replication Kinetics in a Host-Specific Manner

    PubMed Central

    Ftaich, Najate; Ciancia, Claire; Viarouge, Cyril; Barry, Gerald; Ratinier, Maxime; van Rijn, Piet A.; Breard, Emmanuel; Vitour, Damien; Zientara, Stephan; Palmarini, Massimo; Terzian, Christophe

    2015-01-01

    ABSTRACT Bluetongue virus (BTV) is an arbovirus transmitted to livestock by midges of the Culicoides family and is the etiological agent of a hemorrhagic disease in sheep and other ruminants. In mammalian cells, BTV particles are released primarily by virus-induced cell lysis, while in insect cells they bud from the plasma membrane and establish a persistent infection. BTV possesses a ten-segmented double-stranded RNA genome, and NS3 proteins are encoded by segment 10 (Seg-10). The viral nonstructural protein 3 (NS3) plays a key role in mediating BTV egress as well as in impeding the in vitro synthesis of type I interferon in mammalian cells. In this study, we asked whether genetically distant NS3 proteins can alter BTV-host interactions. Using a reverse genetics approach, we showed that, depending on the NS3 considered, BTV replication kinetics varied in mammals but not in insects. In particular, one of the NS3 proteins analyzed harbored a proline at position 24 that leads to its rapid intracellular decay in ovine but not in Culicoides cells and to the attenuation of BTV virulence in a mouse model of disease. Overall, our data reveal that the genetic variability of Seg-10/NS3 differentially modulates BTV replication kinetics in a host-specific manner and highlight the role of the host-specific variation in NS3 protein turnover rate. IMPORTANCE BTV is the causative agent of a severe disease transmitted between ruminants by biting midges of Culicoides species. NS3, encoded by Seg-10 of the BTV genome, fulfills key roles in BTV infection. As Seg-10 sequences from various BTV strains display genetic variability, we assessed the impact of different Seg-10 and NS3 proteins on BTV infection and host interactions. In this study, we revealed that various Seg-10/NS3 proteins alter BTV replication kinetics in mammals but not in insects. Notably, we found that NS3 protein turnover may vary in ovine but not in Culicoides cells due to a single amino acid residue that, most

  7. SU-E-P-15: Technique Factor Modulation and Reference Plane Air Kerma Rates in Response to Simulated Patient Thickness Variations for a Sample of Current Generation Fluoroscopes

    SciTech Connect

    Wunderle, K; Rakowski, J; Dong, F

    2015-06-15

    Purpose: To evaluate and compare approaches to technique factor modulation and air kerma rates in response to simulated patient thickness variations for four state-of-the-art and one previous-generation interventional fluoroscopes. Methods: A polymethyl methacrylate (PMMA) phantom was used as a tissue surrogate for the purposes of determining fluoroscopic reference plane air kerma rates, kVp, mA, and spectral filtration over a wide range of simulated tissue thicknesses. Data were acquired for each fluoroscopic and acquisition dose curve within a default abdomen or body imaging protocol. Results: The data obtained indicated vendor- and model-specific variations in the approach to technique factor modulation and reference plane air kerma rates across a range of tissue thicknesses. Some vendors have made hardware advances increasing the radiation output capabilities of their fluoroscopes; this was evident in the acquisition air kerma rates. However, in the imaging protocol evaluated, all of the state-of-the-art systems had relatively low air kerma rates in the fluoroscopic low-dose imaging mode as compared to the previous-generation unit. Each of the newest-generation systems also employ copper filtration in the selected protocol in the acquisition mode of imaging; this is a substantial benefit, reducing the skin entrance dose to the patient in the highest dose-rate mode of fluoroscope operation. Conclusion: Understanding how fluoroscopic technique factors are modulated provides insight into the vendor-specific image acquisition approach and provides opportunities to optimize the imaging protocols for clinical practice. The enhanced radiation output capabilities of some of the fluoroscopes may, under specific conditions, may be beneficial; however, these higher output capabilities also have the potential to lead to unnecessarily high dose rates. Therefore, all parties involved in imaging, including the clinical team, medical physicists, and imaging vendors, must work

  8. Transcription rates in DNA brushes.

    PubMed

    Yamamoto, Tetsuya; Safran, S A

    2015-04-21

    We theoretically predict the rate of transcription (TX) in DNA brushes by introducing the concept of TX dipoles that takes into account the unidirectional motion of enzymes (RNAP) along DNA during transcription as correlated pairs of sources and sinks in the relevant diffusion equation. Our theory predicts that the TX rates dramatically change upon the inversion of the orientation of the TX dipoles relative to the substrate because TX dipoles modulate the concentrations of RNAP in the solution. Comparing our theory with experiments suggests that, in some cases, DNA chain segments are relatively uniformly distributed in the brush, in contrast to the parabolic profile expected for flexible polymer brushes. PMID:25736601

  9. Modelling Heart Rate Kinetics

    PubMed Central

    Zakynthinaki, Maria S.

    2015-01-01

    The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual’s cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstrate examples of successful numerical fit of the model, constant intensity experimental heart rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women). PMID:25876164

  10. Modelling heart rate kinetics.

    PubMed

    Zakynthinaki, Maria S

    2015-01-01

    The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart rate kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the rate of change of heart rate and the rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual's cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstrate examples of successful numerical fit of the model, constant intensity experimental heart rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women). PMID:25876164

  11. Heart rate turbulence.

    PubMed

    Cygankiewicz, Iwona

    2013-01-01

    Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. PMID:24215748

  12. Neutron monitors and muon detectors for solar modulation studies: Interstellar flux, yield function, and assessment of critical parameters in count rate calculations

    NASA Astrophysics Data System (ADS)

    Maurin, D.; Cheminet, A.; Derome, L.; Ghelfi, A.; Hubert, G.

    2015-01-01

    Particles count rates at given Earth location and altitude result from the convolution of (i) the interstellar (IS) cosmic-ray fluxes outside the solar cavity, (ii) the time-dependent modulation of IS into Top-of-Atmosphere (TOA) fluxes, (iii) the rigidity cut-off (or geomagnetic transmission function) and grammage at the counter location, (iv) the atmosphere response to incoming TOA cosmic rays (shower development), and (v) the counter response to the various particles/energies in the shower. Count rates from neutron monitors or muon counters are therefore a proxy to solar activity. In this paper, we review all ingredients, discuss how their uncertainties impact count rate calculations, and how they translate into variation/uncertainties on the level of solar modulation ϕ (in the simple Force-Field approximation). The main uncertainty for neutron monitors is related to the yield function. However, many other effects have a significant impact, at the 5-10% level on ϕ values. We find no clear ranking of the dominant effects, as some depend on the station position and/or the weather and/or the season. An abacus to translate any variation of count rates (for neutron and μ detectors) to a variation of the solar modulation ϕ is provided.

  13. Asn-150 of Murine Erythroid 5-Aminolevulinate Synthase Modulates the Catalytic Balance between the Rates of the Reversible Reaction.

    PubMed

    Stojanovski, Bosko M; Ferreira, Gloria C

    2015-12-25

    5-Aminolevulinate synthase (ALAS) catalyzes the first step in mammalian heme biosynthesis, the pyridoxal 5'-phosphate (PLP)-dependent and reversible reaction between glycine and succinyl-CoA to generate CoA, CO2, and 5-aminolevulinate (ALA). Apart from coordinating the positioning of succinyl-CoA, Rhodobacter capsulatus ALAS Asn-85 has a proposed role in regulating the opening of an active site channel. Here, we constructed a library of murine erythroid ALAS variants with substitutions at the position occupied by the analogous bacterial asparagine, screened for ALAS function, and characterized the catalytic properties of the N150H and N150F variants. Quinonoid intermediate formation occurred with a significantly reduced rate for either the N150H- or N150F-catalyzed condensation of glycine with succinyl-CoA during a single turnover. The introduced mutations caused modifications in the ALAS active site such that the resulting variants tipped the balance between the forward- and reverse-catalyzed reactions. Although wild-type ALAS catalyzes the conversion of ALA into the quinonoid intermediate at a rate 6.3-fold slower than the formation of the same quinonoid intermediate from glycine and succinyl-CoA, the N150F variant catalyzes the forward reaction at a mere 1.2-fold faster rate than that of the reverse reaction, and the N150H variant reverses the rate values with a 1.7-fold faster rate for the reverse reaction than that for the forward reaction. We conclude that the evolutionary selection of Asn-150 was significant for optimizing the forward enzymatic reaction at the expense of the reverse, thus ensuring that ALA is predominantly available for heme biosynthesis. PMID:26511319

  14. Optical rate sensor algorithms

    NASA Technical Reports Server (NTRS)

    Uhde-Lacovara, Jo A.

    1989-01-01

    Optical sensors, in particular Charge Coupled Device (CCD) arrays, will be used on Space Station to track stars in order to provide inertial attitude reference. Algorithms are presented to derive attitude rate from the optical sensors. The first algorithm is a recursive differentiator. A variance reduction factor (VRF) of 0.0228 was achieved with a rise time of 10 samples. A VRF of 0.2522 gives a rise time of 4 samples. The second algorithm is based on the direct manipulation of the pixel intensity outputs of the sensor. In 1-dimensional simulations, the derived rate was with 0.07 percent of the actual rate in the presence of additive Gaussian noise with a signal to noise ratio of 60 dB.

  15. Time rate collision matrix

    SciTech Connect

    Stoenescu, M.L.; Smith, T.M.

    1980-02-01

    The collision integral terms in Boltzmann equation are reformulated numerically leading to the substitution of the multiple integrals with a multiplicative matrix of the two colliding species velocity distribution functions which varies with the differential collision cross section. A matrix of lower rank may be constructed when one of the distribution functions is specified, in which case the matrix elements represent kinetic transition probabilities in the velocity space and the multiplication of the time rate collision matrix with the unknown velocity distribution function expresses the time rate of change of the distribution. The collision matrix may be used to describe the time evolution of systems in nonequilibrium conditions, to evaluate the rate of momentum and energy transfer between given species, or to generate validity criteria for linearized kinetic equations.

  16. Weather Balloon Ascent Rate

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2016-05-01

    The physics of a weather balloon is analyzed. The surprising aspect of the motion of these balloons is that they ascend to great altitudes (typically 35 km) at a more or less constant rate. Such behavior is not surprising near the ground—say for a helium-filled party balloon rising from street level to the top of the Empire State building—but it is unexpected for a balloon that rises to altitudes where the air is rarefied. We show from elementary physical laws why the ascent rate is approximately constant.

  17. Inertial wave beams and inertial wave modes in a rotating cylinder with time-modulated rotation rate

    NASA Astrophysics Data System (ADS)

    Borcia, Ion D.; Ghasemi V., Abouzar; Harlander, Uwe

    2014-05-01

    Inertial gravity waves play an crucial role in atmospheres, oceans, and the fluid inside of planets and moons. In the atmosphere, the effect of rotation is neglected for small wavelength and the waves bear the character of internal gravity waves. For long waves, the hydrostatic assumption is made which in turn makes the atmosphere inelastic with respect to inertial motion. In contrast, in the Earth's interior, pure inertial waves are considered as an important fundamental part of the motion. Moreover, as the deep ocean is nearly homogeneous, there the inertial gravity waves bear the character of inertial waves. Excited at the oceans surface mainly due to weather systems the waves can propagate downward and influence the deep oceans motion. In the light of the aforesaid it is important to understand better fundamental inertial wave dynamics. We investigate inertial wave modes by experimental and numerical methods. Inertial modes are excited in a fluid filled rotating annulus by modulating the rotation rate of the outer cylinder and the upper and lower lids. This forcing leads to inertial wave beams emitted from the corner regions of the annulus due to periodic motions in the boundary layers (Klein et al., 2013). When the forcing frequency matches with the eigenfrequency of the rotating annulus the beam pattern amplitude is increasing, the beams broaden and mode structures can be observed (Borcia et al., 2013a). The eigenmodes are compared with analytical solutions of the corresponding inviscid problem (Borcia et al, 2013b). In particular for the pressure field a good agreement can be found. However, shear layers related to the excited wave beams are present for all frequencies. This becomes obvious in particular in the experimental visualizations that are done by using Kalliroscope particles, highlighting relative motion in the fluid. Comparing the eigenfrequencies we find that relative to the analytical frequencies, the experimental and numerical ones show a small

  18. A comparison of the rate of space closure using a nickel-titanium spring and an elastic module: a clinical study.

    PubMed

    Samuels, R H; Rudge, S J; Mair, L H

    1993-05-01

    A study of the efficiency of space closure after premolar extraction was undertaken, comparing a nickel-titanium closed coil spring and an elastic retraction module by using sliding mechanics along an 0.019 x 0.025-inch stainless steel arch wire in 0.022 x 0.028-inch preadjusted stainless steel brackets. The rate of space closure in 17 subjects was analyzed from study models and was found to be significantly greater and more consistent with the nickel-titanium closed coil springs than with the elastic modules, in both arches. There were no clinically observable differences in the tooth positions between the respective techniques. PMID:8480716

  19. Spectra of data sampled at frequency-modulated rates in application to cardiovascular signals: Part 2. Evaluation of Fourier transform algorithms.

    PubMed

    TenVoorde, B J; Faes, T J; Rompelman, O

    1994-01-01

    For three direct Fourier transform algorithms we quantified the influence of pulse frequency modulation (PFM) on the spectral estimation of pulse amplitude modulation (PAM). The simulation study is based on sinusoid functions sampled according to a pulse sequence which is the output of an integral pulse frequency modulator (IPFM). One algorithm exactly reproduces the theoretical spectrum derived in Part 1. The other two, including the classical FFT, scale all PFM-induced components in a different way, and in addition, generate higher modulating frequency harmonics. For a PFM depth below 30%, the sum of spurious PFM components is almost linearly dependent on this modulation depth, for all three algorithms. Dividing the effect of PFM in a 'harmonic' and 'aliasing' distortion, we found that the FFT has a relatively high harmonic distortion, compared to an algorithm that takes into account the non-uniform character of the data. In the cardiovascular (worst) case of 30% modulation in heart rate (PFM) at a frequency of 0.1 Hz, the FFT spectrum of beat-to-beat systolic blood pressure variations contains approximately 20% of spurious components caused solely by the modulation in time occurrences of the blood pressure samples. The 'non-uniform' algorithm performs twice as well in this case. PMID:8182965

  20. Controlling Your Utility Rates.

    ERIC Educational Resources Information Center

    Lucht, Ray; Dembowski, Frederick L.

    1985-01-01

    A cost-effective alternative to high utility bills for middle-sized and smaller utility users is the service of utility rate consultants. The consultants analyze utility invoices for the previous 12 months to locate available refunds or credits. (MLF)

  1. Currency Exchange Rates.

    ERIC Educational Resources Information Center

    Siler, Carl R.

    This curriculum unit of the Muncie (Indiana) Southside High School is to simulate the dynamics of foreign currency exchange rates from the perspectives of: (1) a major U.S. corporation, ABB Power T & D Company, Inc., of Muncie, Indiana, a manufacturer of large power transformers for the domestic and foreign markets; and (2) individual consumers…

  2. Paradoxes in Film Ratings

    ERIC Educational Resources Information Center

    Moore, Thomas L.

    2006-01-01

    The author selected a simple random sample of 100 movies from the "Movie and Video Guide" (1996), by Leonard Maltin. The author's intent was to obtain some basic information on the population of roughly 19,000 movies through a small sample. The "Movie and Video Guide" by Leonard Maltin is an annual ratings guide to movies. While not all films ever…

  3. DATA ATTRIBUTE RATING SYSTEM

    EPA Science Inventory

    The paper discusses a data attribute rating system (DARS), developed by EPA to assist in evaluating data associated with emission inventories. he paper presents DARS for evaluation by the potential user community. ARS was originally conceived as a method for evaluating country-sp...

  4. Variable rate irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systems are available to producers to make variable-rate applications of defoliants, fertilizer, lime, pesticides, plant growth regulators, and seed. These systems could potentially offer cost savings to a producer; however, the full potential of the benefits and savings cannot be realized if water ...

  5. Variable Rate Irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systems are available to producers with the ability to make variable-rate applications of defoliants, fertilizer, lime, pesticides, plant growth regulators, and seed. These systems could potentially offer a producer great cost savings; however, the full potential of these benefits and savings cannot...

  6. Toy Stories: Modeling Rates

    ERIC Educational Resources Information Center

    Swanson, Patricia E.

    2015-01-01

    Elementary school mathematics is increasingly recognized for its crucial role in developing the foundational skills and understandings for algebra. In this article, the author uses a lesson to introduce the concept of "rates"--comparing two different types and units of measure--and how to graph them. Described is the lesson and shared…

  7. Understanding Rates of Change.

    ERIC Educational Resources Information Center

    Weil, Aurelia; Russell, Larry

    This paper presents three activities on how to analyze rates of change in real-life situations using TI-83 calculators and computer-based laboratories. Activities include 24 hour temperature data, the temperature of a light bulb, and an M&M toss. Each section contains descriptions of equipment/materials, data collection, and data analysis. The…

  8. 78 FR 18664 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to the average SBA direct loan. This rate may be used as a base rate...

  9. Prolonged Adaptation to a Low or High Protein Diet Does Not Modulate Basal Muscle Protein Synthesis Rates – A Substudy

    PubMed Central

    Hursel, Rick; Martens, Eveline A. P.; Gonnissen, Hanne K. J.; Hamer, Henrike M.; Senden, Joan M. G.; van Loon, Luc J. C.; Westerterp-Plantenga, Margriet S.

    2015-01-01

    Background Based on controlled 36 h experiments a higher dietary protein intake causes a positive protein balance and a negative fat balance. A positive net protein balance may support fat free mass accrual. However, few data are available on the impact of more prolonged changes in habitual protein intake on whole-body protein metabolism and basal muscle protein synthesis rates. Objective To assess changes in whole-body protein turnover and basal muscle protein synthesis rates following 12 weeks of adaptation to a low versus high dietary protein intake. Methods A randomized parallel study was performed in 40 subjects who followed either a high protein (2.4 g protein/kg/d) or low protein (0.4 g protein/kg/d) energy-balanced diet (30/35/35% or 5/60/35% energy from protein/carbohydrate/fat) for a period of 12 weeks. A subgroup of 7 men and 8 women (body mass index: 22.8±2.3 kg/m2, age: 24.3±4.9 y) were selected to evaluate the impact of prolonged adaptation to either a high or low protein intake on whole body protein metabolism and basal muscle protein synthesis rates. After the diet, subjects received continuous infusions with L-[ring-2H5]phenylalanine and L-[ring-2H2]tyrosine in an overnight fasted state, with blood samples and muscle biopsies being collected to assess post-absorptive whole-body protein turnover and muscle protein synthesis rates in vivo in humans. Results After 12 weeks of intervention, whole-body protein balance in the fasted state was more negative in the high protein treatment when compared with the low protein treatment (-4.1±0.5 vs -2.7±0.6 μmol phenylalanine/kg/h;P<0.001). Whole-body protein breakdown (43.0±4.4 vs 37.8±3.8 μmol phenylalanine/kg/h;P<0.03), synthesis (38.9±4.2 vs 35.1±3.6 μmol phenylalanine/kg/h;P<0.01) and phenylalanine hydroxylation rates (4.1±0.6 vs 2.7±0.6 μmol phenylalanine/kg/h;P<0.001) were significantly higher in the high vs low protein group. Basal muscle protein synthesis rates were maintained on a low

  10. Radiation dose rate meter

    SciTech Connect

    Kronenberg, S.; Siebentritt, C.R.

    1981-07-28

    A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts.

  11. Sequoia Messaging Rate Benchmark

    SciTech Connect

    Friedley, Andrew

    2008-01-22

    The purpose of this benchmark is to measure the maximal message rate of a single compute node. The first num_cores ranks are expected to reside on the 'core' compute node for which message rate is being tested. After that, the next num_nbors ranks are neighbors for the first core rank, the next set of num_nbors ranks are neighbors for the second core rank, and so on. For example, testing an 8-core node (num_cores = 8) with 4 neighbors (num_nbors = 4) requires 8 + 8 * 4 - 40 ranks. The first 8 of those 40 ranks are expected to be on the 'core' node being benchmarked, while the rest of the ranks are on separate nodes.

  12. Sequoia Messaging Rate Benchmark

    Energy Science and Technology Software Center (ESTSC)

    2008-01-22

    The purpose of this benchmark is to measure the maximal message rate of a single compute node. The first num_cores ranks are expected to reside on the 'core' compute node for which message rate is being tested. After that, the next num_nbors ranks are neighbors for the first core rank, the next set of num_nbors ranks are neighbors for the second core rank, and so on. For example, testing an 8-core node (num_cores = 8)more » with 4 neighbors (num_nbors = 4) requires 8 + 8 * 4 - 40 ranks. The first 8 of those 40 ranks are expected to be on the 'core' node being benchmarked, while the rest of the ranks are on separate nodes.« less

  13. Rotational rate sensor

    DOEpatents

    Hunter, Steven L.

    2002-01-01

    A rate sensor for angular/rotational acceleration includes a housing defining a fluid cavity essentially completely filled with an electrolyte fluid. Within the housing, such as a toroid, ions in the fluid are swept during movement from an excitation electrode toward one of two output electrodes to provide a signal for directional rotation. One or more ground electrodes within the housing serve to neutralize ions, thus preventing any effect at the other output electrode.

  14. Polarization-multiplexed rate-adaptive non-binary-quasi-cyclic-LDPC-coded multilevel modulation with coherent detection for optical transport networks.

    PubMed

    Arabaci, Murat; Djordjevic, Ivan B; Saunders, Ross; Marcoccia, Roberto M

    2010-02-01

    In order to achieve high-speed transmission over optical transport networks (OTNs) and maximize its throughput, we propose using a rate-adaptive polarization-multiplexed coded multilevel modulation with coherent detection based on component non-binary quasi-cyclic (QC) LDPC codes. Compared to prior-art bit-interleaved LDPC-coded modulation (BI-LDPC-CM) scheme, the proposed non-binary LDPC-coded modulation (NB-LDPC-CM) scheme not only reduces latency due to symbol- instead of bit-level processing but also provides either impressive reduction in computational complexity or striking improvements in coding gain depending on the constellation size. As the paper presents, compared to its prior-art binary counterpart, the proposed NB-LDPC-CM scheme addresses the needs of future OTNs, which are achieving the target BER performance and providing maximum possible throughput both over the entire lifetime of the OTN, better. PMID:20174010

  15. Longitudinal Assessment of Global and Regional Rate of Grey Matter Atrophy in 1,172 Healthy Older Adults: Modulation by Sex and Age

    PubMed Central

    Crivello, Fabrice; Tzourio-Mazoyer, Nathalie; Tzourio, Christophe; Mazoyer, Bernard

    2014-01-01

    To characterize the neuroanatomical changes in healthy older adults is important to differentiate pathological from normal brain structural aging. The present study investigated the annualized rate of GM atrophy in a large sample of older participants, focusing on the hippocampus, and searching for modulation by age and sex. In this 4-year longitudinal community cohort study, we used a VBM analysis to estimate the annualized rate of GM loss, at both the global and regional levels, in 1,172 healthy older adults (65–82 years) scanned at 1.5T. The global annualized rate of GM was −4.0 cm3/year (−0.83%/year). The highest rates of regional GM loss were found in the frontal and parietal cortices, middle occipital gyri, temporal cortex and hippocampus. The rate of GM atrophy was higher in women (−4.7 cm3/year, −0.91%/year) than men (−3.3 cm3/year, −0.65%/year). The global annualized rate of GM atrophy remained constant throughout the age range of the cohort, in both sexes. This pattern was replicated at the regional level, with the exception of the hippocampi, which showed a rate of GM atrophy that accelerated with age (2.8%/year per year of age) similarly for men and women. The present study reports a global and regional description of the annualized rate of grey matter loss and its evolution after the age of 65. Our results suggest greater anatomical vulnerability of women in late life and highlight a specific vulnerability of the hippocampus to the aging processes after 65 years of age. PMID:25469789

  16. Recombination Rate Variation Modulates Gene Sequence Evolution Mainly via GC-Biased Gene Conversion, Not Hill–Robertson Interference, in an Avian System

    PubMed Central

    Bolívar, Paulina; Mugal, Carina F.; Nater, Alexander; Ellegren, Hans

    2016-01-01

    The ratio of nonsynonymous to synonymous substitution rates (ω) is often used to measure the strength of natural selection. However, ω may be influenced by linkage among different targets of selection, that is, Hill–Robertson interference (HRI), which reduces the efficacy of selection. Recombination modulates the extent of HRI but may also affect ω by means of GC-biased gene conversion (gBGC), a process leading to a preferential fixation of G:C (“strong,” S) over A:T (“weak,” W) alleles. As HRI and gBGC can have opposing effects on ω, it is essential to understand their relative impact to make proper inferences of ω. We used a model that separately estimated S-to-S, S-to-W, W-to-S, and W-to-W substitution rates in 8,423 avian genes in the Ficedula flycatcher lineage. We found that the W-to-S substitution rate was positively, and the S-to-W rate negatively, correlated with recombination rate, in accordance with gBGC but not predicted by HRI. The W-to-S rate further showed the strongest impact on both dN and dS. However, since the effects were stronger at 4-fold than at 0-fold degenerated sites, likely because the GC content of these sites is farther away from its equilibrium, ω slightly decreases with increasing recombination rate, which could falsely be interpreted as a consequence of HRI. We corroborated this hypothesis analytically and demonstrate that under particular conditions, ω can decrease with increasing recombination rate. Analyses of the site-frequency spectrum showed that W-to-S mutations were skewed toward high, and S-to-W mutations toward low, frequencies, consistent with a prevalent gBGC-driven fixation bias. PMID:26446902

  17. T3 rapidly modulates TSHβ mRNA stability and translational rate in the pituitary of hypothyroid rats.

    PubMed

    Goulart-Silva, Francemilson; de Souza, Paula Bargi; Nunes, Maria Tereza

    2011-01-30

    Whereas it is well known that T3 inhibits TSHβ gene transcription, its effects on TSHβ mRNA stability and translation have been poorly investigated. This study examined these possibilities, by evaluating the TSHβ transcripts poly(A) tail length, translational rate and binding to cytoskeleton, in pituitaries of thyroidectomized and sham-operated rats treated with T3 or saline, and killed 30 min thereafter. The hypothyroidism induced an increase of TSHβ transcript poly(A) tail, as well as of its content in ribosomes and attachment to cytoskeleton. The hypothyroid rats acutely treated with T3 exhibited a reduction of TSHβ mRNA poly(A) tail length and recruitment to ribosomes, indicating that this treatment decreased the stability and translation rate of TSHβ mRNA. Nevertheless, acute T3 administration to sham-operated rats provoked an increase of TSHβ transcripts binding to ribosomes. These data add new insight to an important role of T3 in rapidly regulating TSH gene expression at posttranscriptional level. PMID:21078364

  18. Considerations for How to Rate CPV

    SciTech Connect

    Kurtz, S.; Miller, M.; Marion, B.; Emery, K.; McConnell, R.; Surendran, S.; Kimber, A.

    2011-02-01

    The concentrator photovoltaic (CPV) industry is introducing multiple products into the marketplace, but, as yet, the; community has not embraced a unified method for assessing a nameplate rating. The choices of whether to use 850,; 900, or 1000 W/m2 for the direct-normal irradiance and whether to link the rating to ambient or cell temperature will; affect how CPV modules are rated and compared with other technologies. This paper explores the qualitative and; quantitative ramifications of these choices using data from two multi-junction CPV modules and two flat-plate; modules.

  19. Dual Brushless Resolver Rate Sensor

    NASA Technical Reports Server (NTRS)

    Howard, David E. (Inventor)

    1997-01-01

    A resolver rate sensor is disclosed in which dual brushless resolvers are mechanically coupled to the same output shaft. Diverse inputs are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. In one embodiment of the invention the outputs of the first resolver are directly inputted into two separate multipliers and the outputs of the second resolver are inputted into the two separate multipliers, after being demodulated in a pair of demodulator circuits. The multiplied signals are then added in an adder circuit to provide a directional sensitive output. In another embodiment the outputs from the first resolver is modulated in separate modulator circuits and the output from the modulator circuits are used to excite the second resolver. The outputs from the second resolver are demodulated in separate demodulator circuit and added in an adder circuit to provide a direction sensitive rate output.

  20. Photovoltaic Degradation Rates -- An Analytical Review

    SciTech Connect

    Jordan, D. C.; Kurtz, S. R.

    2012-06-01

    As photovoltaic penetration of the power grid increases, accurate predictions of return on investment require accurate prediction of decreased power output over time. Degradation rates must be known in order to predict power delivery. This article reviews degradation rates of flat-plate terrestrial modules and systems reported in published literature from field testing throughout the last 40 years. Nearly 2000 degradation rates, measured on individual modules or entire systems, have been assembled from the literature, showing a median value of 0.5%/year. The review consists of three parts: a brief historical outline, an analytical summary of degradation rates, and a detailed bibliography partitioned by technology.

  1. PULSE RATE DIVIDER

    DOEpatents

    McDonald, H.C. Jr.

    1962-12-18

    A compact pulse-rate divider circuit affording low impedance output and high input pulse repetition rates is described. The circuit features a single secondary emission tube having a capacitor interposed between its dynode and its control grid. An output pulse is produced at the anode of the tube each time an incoming pulse at the control grid drives the tube above cutoff and the duration of each output pulse corresponds to the charging time of the capacitor. Pulses incoming during the time the grid bias established by the discharging capacitor is sufficiently negative that the pulses are unable to drive the tube above cutoff do not produce output pulses at the anode; these pulses are lost and a dividing action is thus produced by the circuit. The time constant of the discharge path may be vanied to vary in turn the division ratio of the circuit; the time constant of the charging circuit may be varied to vary the width of the output pulses. (AEC)

  2. Survival Rates for Thymus Cancer

    MedlinePlus

    ... staged? Next Topic How is thymus cancer treated? Survival rates for thymus cancer Survival rates are often ... into account. Stage of thymoma 5-year observed survival rate I 74% II 73% III 64% IV ...

  3. Experimental warming and precipitation interactively modulate the mortality rate and timing of spring emergence of a gallmaking Tephritid fly

    PubMed Central

    Xi, Xinqiang; Li, Dongbo; Peng, Youhong; Eisenhauer, Nico; Sun, Shucun

    2016-01-01

    Global climate change is mostly characterized by temperature increase and fluctuating precipitation events, which may affect the spring phenology and mortality rate of insects. However, the interaction effect of temperature and precipitation on species performance has rarely been examined. Here we studied the response of the gall-making Tephritid fly Urophora stylata (Diptera: Tephritidae) to artificial warming, changes in precipitation, and the presence of galls. Our results revealed a significant interaction effect of warming, precipitation, and galls on the life-history traits of the focal species. Specifically, when the galls were intact, warming had no effect on the phenology and increased the mortality of the fly under decreased precipitation, but it significantly advanced the timing of adult emergence and had no effect on the mortality under increased precipitation. When galls were removed, warming significantly advanced the timing of emergence and increased fly mortality, but precipitation showed no effect on the phenology and mortality. In addition, gall removal significantly increased adult fresh mass for both females and males. Our results indicate that the effect of elevated temperature on the performance of species may depend on other environmental conditions, such as variations in precipitation, and species traits like the formation of galls. PMID:27578601

  4. Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

    NASA Technical Reports Server (NTRS)

    Westerlind, K. C.; Wronski, T. J.; Ritman, E. L.; Luo, Z. P.; An, K. N.; Bell, N. H.; Turner, R. T.

    1997-01-01

    Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain.

  5. Frequency-dependent reduction of voltage-gated sodium current modulates retinal ganglion cell response rate to electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsai, David; Morley, John W.; Suaning, Gregg J.; Lovell, Nigel H.

    2011-10-01

    The ability to elicit visual percepts through electrical stimulation of the retina has prompted numerous investigations examining the feasibility of restoring sight to the blind with retinal implants. The therapeutic efficacy of these devices will be strongly influenced by their ability to elicit neural responses that approximate those of normal vision. Retinal ganglion cells (RGCs) can fire spikes at frequencies greater than 200 Hz when driven by light. However, several studies using isolated retinas have found a decline in RGC spiking response rate when these cells were stimulated at greater than 50 Hz. It is possible that the mechanism responsible for this decline also contributes to the frequency-dependent 'fading' of electrically evoked percepts recently reported in human patients. Using whole-cell patch clamp recordings of rabbit RGCs, we investigated the causes for the spiking response depression during direct subretinal stimulation of these cells at 50-200 Hz. The response depression was not caused by inhibition arising from the retinal network but, instead, by a stimulus-frequency-dependent decline of RGC voltage-gated sodium current. Under identical experimental conditions, however, RGCs were able to spike at high frequency when driven by light stimuli and intracellular depolarization. Based on these observations, we demonstrated a technique to prevent the spiking response depression.

  6. Soil temperature and intermittent frost modulate the rate of recovery of photosynthesis in Scots pine under simulated spring conditions.

    PubMed

    Ensminger, Ingo; Schmidt, Lilian; Lloyd, Jon

    2008-01-01

    An earlier onset of photosynthesis in spring for boreal forest trees is predicted as the climate warms, yet the importance of soil vs air temperatures for spring recovery remains to be determined. Effects of various soil- and air-temperature conditions on spring recovery of photosynthesis in Scots pine (Pinus sylvestris) seedlings were assessed under controlled environmental conditions. Using winter-acclimated seedlings, photosynthetic responses were followed after transfer to different simulated spring conditions. Recovery rates for photosynthetic electron transport and net CO(2) uptake were slower in plants from cold or frozen soil compared with controls. In addition, a greater fraction of light absorbed was not used photochemically, but was dissipated thermally via xanthophyll cycle pigments. Intermittent frost events decreased photosynthetic capacity and increased thermal energy dissipation. Within a few days after frost events, photosynthetic capacity recovered to prefrost levels. After 18 d under spring conditions, no difference in the optimum quantum yield of photosynthesis was observed between seedlings that had been exposed to intermittent frost and control plants. These results show that, if air temperatures remain favourable and spells of subfreezing air temperatures are only of short duration, intermittent frost events delay but do not severely inhibit photosynthetic recovery in evergreen conifers during spring. Cold and/or frozen soils exert much stronger inhibitory effects on the recovery process, but they do not totally inhibit it. PMID:18181961

  7. Experimental warming and precipitation interactively modulate the mortality rate and timing of spring emergence of a gallmaking Tephritid fly.

    PubMed

    Xi, Xinqiang; Li, Dongbo; Peng, Youhong; Eisenhauer, Nico; Sun, Shucun

    2016-01-01

    Global climate change is mostly characterized by temperature increase and fluctuating precipitation events, which may affect the spring phenology and mortality rate of insects. However, the interaction effect of temperature and precipitation on species performance has rarely been examined. Here we studied the response of the gall-making Tephritid fly Urophora stylata (Diptera: Tephritidae) to artificial warming, changes in precipitation, and the presence of galls. Our results revealed a significant interaction effect of warming, precipitation, and galls on the life-history traits of the focal species. Specifically, when the galls were intact, warming had no effect on the phenology and increased the mortality of the fly under decreased precipitation, but it significantly advanced the timing of adult emergence and had no effect on the mortality under increased precipitation. When galls were removed, warming significantly advanced the timing of emergence and increased fly mortality, but precipitation showed no effect on the phenology and mortality. In addition, gall removal significantly increased adult fresh mass for both females and males. Our results indicate that the effect of elevated temperature on the performance of species may depend on other environmental conditions, such as variations in precipitation, and species traits like the formation of galls. PMID:27578601

  8. Modulation of the reaction rate of regulating protein induces large morphological and motional change of amoebic cell.

    PubMed

    Nishimura, Shin I; Sasai, Masaki

    2007-03-21

    Morphologies of moving amoebae are categorized into two types. One is the "neutrophil" type in which the long axis of cell roughly coincides with its moving direction. This type of cell extends a leading edge at the front and retracts a narrow tail at the rear, whose shape has been often drawn as a typical amoeba in textbooks. The other one is the "keratocyte" type with widespread lamellipodia along the front side arc. Short axis of cell in this type roughly coincides with its moving direction. In order to understand what kind of molecular feature causes conversion between two types of morphologies, and how two typical morphologies are maintained, a mathematical model of amoebic cells is developed. This model describes movement of cell and intracellular reactions of activator, inhibitor and actin filaments in a unified way. It is found that the producing rate of activator is a key factor of conversion between two types. This model also explains the observed data that the keratocyte type cells tend to rapidly move along a straight line. The neutrophil type cells move along a straight line when the moving velocity is small, but they show fluctuated motions deviating from a line when they move as fast as the keratocyte type cells. Efficient energy consumption in the neutrophil type cells is predicted. PMID:17113108

  9. Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

    PubMed Central

    Westerlind, Kim C.; Wronski, Thomas J.; Ritman, Erik L.; Luo, Zong-Ping; An, Kai-Nan; Bell, Norman H.; Turner, Russell T.

    1997-01-01

    Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain. PMID:9108129

  10. Heart-Rate and Breath-Rate Monitor

    NASA Technical Reports Server (NTRS)

    Cooper, T. G.

    1983-01-01

    Circuit requiring only four integrated circuits (IC's) measures both heart rate and breath rate. Phase-locked loops lock on heart-rate and respiration-rate input signals. Each loop IC contains two phase comparators. Positive-edge-triggered circuit used in making monitors insensitive to dutycycle variations.

  11. Average bit error rate performance analysis of subcarrier intensity modulated MRC and EGC FSO systems with dual branches over M distribution turbulence channels

    NASA Astrophysics Data System (ADS)

    Wang, Ran-ran; Wang, Ping; Cao, Tian; Guo, Li-xin; Yang, Yintang

    2015-07-01

    Based on the space diversity reception, the binary phase-shift keying (BPSK) modulated free space optical (FSO) system over Málaga (M) fading channels is investigated in detail. Under independently and identically distributed and independently and non-identically distributed dual branches, the analytical average bit error rate (ABER) expressions in terms of H-Fox function for maximal ratio combining (MRC) and equal gain combining (EGC) diversity techniques are derived, respectively, by transforming the modified Bessel function of the second kind into the integral form of Meijer G-function. Monte Carlo (MC) simulation is also provided to verify the accuracy of the presented models.

  12. Psychrophilic (6--15 {degree}C) high-rate anaerobic treatment of malting wastewater in a two-module expanded granular sludge bed system

    SciTech Connect

    Rebac, S.; Lier, J.B. van; Lens, P.; Cappellen, J. van; Vermeulen, M.; Stams, A.J.M.; Lettinga, G.; Dekkers, F.; Swinkels, K.T.M.

    1998-11-01

    Psychrophilic (6--15 C) anaerobic treatment of malting wastewater was investigated. A two-module expanded granular sludge bed reactor system with a total volume of 140 dm{sup 3} was used to treat malting wastewater having a soluble and total chemical oxygen demand (COD) between 233 and 1778 mg dm{sup {minus}3} and between 317 and 4422 mg dm{sup {minus}3}, respectively. The removal efficiencies at 6 C were 47 and 71% of the soluble and volatile fatty acids (VFA) COD, at organic loading rates (OLR) ranging between 3.3 and 5.8 kg of COD m{sup {minus}3} day{sup {minus}1}. The removal efficiencies at 10--15 C were 67--78 and 90--96% of the soluble and VFA COD at an OLR between 2.8 and 12.3 kg of COD m{sup {minus}3} day{sup {minus}1}. The specific methanogenic activity of the sludge present in each module increased 2--3-fold during system operation for 400 days. The relatively high concentration of suspended solids in the influent (25% of the total COD) caused a deterioration of the sludge bed in the first reactor module. This was aggravated by excessive growth of acidifying biomass, which persisted in the first module sludge bed and resulted in granular sludge flotation. However, the second module could accommodate the increased OLR, this providing a very high effluent quality (soluble COD < 200 mg dm{sup {minus}3}) of the total system. The stability of module 1 concerning suspended solids could be restored by presettling the wastewater.

  13. 29 CFR 778.112 - Day rates and job rates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Day rates and job rates. 778.112 Section 778.112 Labor... Requirements Principles for Computing Overtime Pay Based on the âregular Rateâ § 778.112 Day rates and job rates. If the employee is paid a flat sum for a day's work or for doing a particular job, without...

  14. 29 CFR 778.112 - Day rates and job rates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Day rates and job rates. 778.112 Section 778.112 Labor... Requirements Principles for Computing Overtime Pay Based on the âregular Rateâ § 778.112 Day rates and job rates. If the employee is paid a flat sum for a day's work or for doing a particular job, without...

  15. 29 CFR 778.112 - Day rates and job rates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Day rates and job rates. 778.112 Section 778.112 Labor... Requirements Principles for Computing Overtime Pay Based on the âregular Rateâ § 778.112 Day rates and job rates. If the employee is paid a flat sum for a day's work or for doing a particular job, without...

  16. 29 CFR 778.112 - Day rates and job rates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Day rates and job rates. 778.112 Section 778.112 Labor... Requirements Principles for Computing Overtime Pay Based on the âregular Rateâ § 778.112 Day rates and job rates. If the employee is paid a flat sum for a day's work or for doing a particular job, without...

  17. 29 CFR 778.112 - Day rates and job rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Day rates and job rates. 778.112 Section 778.112 Labor... Requirements Principles for Computing Overtime Pay Based on the âregular Rateâ § 778.112 Day rates and job rates. If the employee is paid a flat sum for a day's work or for doing a particular job, without...

  18. Iron Oxide Nanoparticle Agglomeration Influences Dose-Rates and Modulates Oxidative Stress Mediated Dose-Response Profiles In Vitro

    SciTech Connect

    Sharma, Gaurav; Kodali, Vamsi K.; Gaffrey, Matthew J.; Wang, Wei; Minard, Kevin R.; Karin, Norman J.; Teeguarden, Justin G.; Thrall, Brian D.

    2013-07-31

    Spontaneous agglomeration of engineered nanoparticles (ENPs) is a common problem in cell culture media which can confound interpretation of in vitro nanotoxicity studies. The authors created stable agglomerates of iron oxide nanoparticles (IONPs) in conventional culture medium, which varied in hydrodynamic size (276 nm-1.5 μm) but were composed of identical primary particles with similar surface potentials and protein coatings. Studies using C10 lung epithelial cells show that the dose rate effects of agglomeration can be substantial, varying by over an order of magnitude difference in cellular dose in some cases. Quantification by magnetic particle detection showed that small agglomerates of carboxylated IONPs induced greater cytotoxicity and redox-regulated gene expression when compared with large agglomerates on an equivalent total cellular IONP mass dose basis, whereas agglomerates of amine-modified IONPs failed to induce cytotoxicity or redox-regulated gene expression despite delivery of similar cellular doses. Dosimetry modelling and experimental measurements reveal that on a delivered surface area basis, large and small agglomerates of carboxylated IONPs have similar inherent potency for the generation of ROS, induction of stress-related genes and eventual cytotoxicity. The results suggest that reactive moieties on the agglomerate surface are more efficient in catalysing cellular ROS production than molecules buried within the agglomerate core. Because of the dynamic, size and density-dependent nature of ENP delivery to cells in vitro, the biological consequences of agglomeration are not discernible from static measures of exposure concentration (μg/ml) alone, highlighting the central importance of integrated physical characterisation and quantitative dosimetry for in vitro studies. The combined experimental and computational approach provides a quantitative framework for evaluating relationships between the biocompatibility of nanoparticles and their

  19. Towards Stable Lithium-Sulfur Batteries with a Low Self-Discharge Rate: Ion Diffusion Modulation and Anode Protection.

    PubMed

    Xu, Wen-Tao; Peng, Hong-Jie; Huang, Jia-Qi; Zhao, Chen-Zi; Cheng, Xin-Bing; Zhang, Qiang

    2015-09-01

    The self-discharge of a lithium-sulfur cell decreases the shelf-life of the battery and is one of the bottlenecks that hinders its practical applications. New insights into both the internal chemical reactions in a lithium-sulfur system and effective routes to retard self-discharge for highly stable batteries are crucial for the design of lithium-sulfur cells. Herein, a lithium-sulfur cell with a carbon nanotube/sulfur cathode and lithium-metal anode in lithium bis(trifluoromethanesulfonyl)imide/1,3-dioxolane/dimethyl ether electrolyte was selected as the model system to investigate the self-discharge behavior. Both lithium anode passivation and polysulfide anion diffusion suppression strategies are applied to reduce self-discharge of the lithium-sulfur cell. When the lithium-metal anode is protected by a high density passivation layer induced by LiNO3 , a very low shuttle constant of 0.017 h(-1) is achieved. The diffusion of the polysulfides is retarded by an ion-selective separator, and the shuttle constants decreased. The cell with LiNO3 additive maintained a discharge capacity of 97 % (961 mAh g(-1) ) of the initial capacity after 120 days at open circuit, which was around three times higher than the routine cell (32 % of initial capacity, corresponding to 320 mAh g(-1) ). It is expected that lithium-sulfur batteries with ultralow self-discharge rates may be fabricated through a combination of anode passivation and polysulfide shuttle control, as well as optimization of the lithium-sulfur cell configuration. PMID:26079671

  20. Rates of Earth degassing

    NASA Technical Reports Server (NTRS)

    Onions, R. K.

    1994-01-01

    The degassing of the Earth during accretion is constrained by Pu-U-I-Xe systematics. Degassing was much more efficient during the first 100-200 Ma than subsequently, and it was more complete for Xe than for the lighter gases. More than 90 percent of the degassed Xe escaped from the atmosphere during this period. The combination of fractional degassing of melts and rare gas escape from the atmosphere is able to explain the deficit of terrestrial Xe as a simple consequence of this early degassing history. By the time Xe was quantitatively retained in the atmosphere, the abundances of Kr and the lighter gases in the Earth's interior were similar to or higher than the present-day atmospheric abundances. Subsequent transfer of these lighter rare gases into the atmosphere requires a high rate of post-accretion degassing and melt production. Considerations of Pu-U-Xe systematics suggest that relatively rapid post-accretion degassing was continued to ca. 4.1-4.2 Ga. The present-day degassing history of the Earth is investigated through consideration of rare gas isotope abundances. Although the Earth is a highly degassed body, depleted in rare gases by many orders of magnitude relative to their solar abundances, it is at the present-day losing primordial rare gases which were trapped at the time of accretion.

  1. Rate of Lysozyme Crystallization

    NASA Astrophysics Data System (ADS)

    Baird, J. K.; Clunie, J. C.

    1997-03-01

    We have observed the following: Free solution measurements of the electrophoretic mobility of hen egg-white lysozyme crystals grown in aqueous NaCl at 10 deg C at pH values between 3.6 and 5.7 demonstrate that the crystals are positively charged.(J.K. Baird, A.M. Holmes, and J.C. Clunie, Bull.Am.Phys.Soc. 41, 620 (1996)) (2) When the decaying concentration of uncrystallized lysozyme in the growth solution is monitored as a function of time, the log of the half-life decreases linearly with the square-root of the ionic strength. (3) Acid-base titration shows that lysozyme molecules in solution exist as highly charged cations.(R. Roxby and C. Tanford, Biochemistry 10, 3348 (1971)) These three observations combine to suggest that lysozyme crystallizes by addition of lysozyme cations to positively charged crystal nuclei and that the rate is accelerated by the presence of strong electrolytes.

  2. 77 FR 20476 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  3. 77 FR 59447 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-27

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  4. 75 FR 60152 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  5. 78 FR 62932 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  6. 78 FR 39434 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  7. 77 FR 39560 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  8. 77 FR 76586 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  9. 75 FR 81326 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  10. 76 FR 38717 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  11. 76 FR 77581 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to...

  12. 75 FR 37872 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  13. 76 FR 18821 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  14. 75 FR 5342 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-02

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... preliminary annual fee rates of 0.00% for tier 1 and 0.060% (.00060) for tier 2 for calendar year 2010. These... fee rate on class II revenues for calendar year 2010 shall be one-half of the annual fee rate,...

  15. 77 FR 41202 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... annual fee rates of 0.00% for tier 1 and 0.074% (.00074) for tier 2 for calendar year 2012. These rates... Commission. If a Tribe has a certificate of self-regulation under 25 CFR part 518, the final fee rate...

  16. 78 FR 14821 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... National Indian Gaming Commission Fee Rate AGENCY: National Indian Gaming Commission, Interior. ACTION... Commission has adopted its 2013 preliminary annual fee rates of 0.00% for tier 1 and 0.074% (.00074) for tier... preliminary fee rate on Class II revenues shall be one-half of the annual fee rate, which is 0.037%...

  17. 76 FR 38207 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... annual fee rates of 0.00% for tier 1 and 0.074% (.00074) for tier 2 for calendar year 2011. These rates... Commission. If a tribe has a certificate of self-regulation under 25 CFR part 518, the final fee rate...

  18. 76 FR 7879 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... preliminary annual fee rates of 0.00% for tier 1 and 0.074% (.00074) for tier 2 for calendar year 2011. These... fee rate on class II revenues for calendar year 2011 shall be one-half of the annual fee rate,...

  19. 77 FR 5267 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... preliminary annual fee rates of 0.00% for tier 1 and 0.074% (.00074) for tier 2 for calendar year 2012. These... fee rate on class II revenues for calendar year 2012 shall be one-half of the annual fee rate,...

  20. 76 FR 8946 - Security Ratings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ... COMMISSION 17 CFR Parts 200, 229, 230, 232, 239, 240, and 249 RIN 3235-AK18 Security Ratings AGENCY... will be considering relating to the use of security ratings by credit rating agencies in our rules and... that rely on, or make special accommodations for, security ratings (for example, Forms S-3 and...

  1. Sequential Effects in Essay Ratings

    ERIC Educational Resources Information Center

    Attali, Yigal

    2011-01-01

    Contrary to previous research on sequential ratings of student performance, this study found that professional essay raters of a large-scale standardized testing program produced ratings that were drawn toward previous ratings, creating an assimilation effect. Longer intervals between the two adjacent ratings and higher degree of agreement with…

  2. Primate disease and breeding rates.

    PubMed

    Chamove, A; Cameron, G; Nash, V

    1979-10-01

    33 species were compared for 12 disease categories over 3 years of laboratory housing. There were low correlations between popularity, birth, death, and illness rates. Highest rates were: birth, Macaca nemestrina; illness, Pongo pygmaeus; death, Cercopithecus aethiops. Lowest rates were: birth, Lemur catta; illness, Sanguinus mystax; death, Galago crassicaudatus. Galago crassicaudatus and Macaca fasicularus had low disease and high birth rates. PMID:119108

  3. 75 FR 17453 - Interest Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Interest Rates The Small Business Administration publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate is a weighted average cost of money to the government for maturities similar to...

  4. Modulation of pumping rate by two species of marine bivalve molluscs in response to neurotransmitters: Comparison of in vitro and in vivo results.

    PubMed

    Frank, Dana M; Deaton, Lewis; Shumway, Sandra E; Holohan, Bridget A; Ward, J Evan

    2015-07-01

    Most studies regarding the neuroanatomy and neurophysiology of molluscan ctenidia have focused on isolated ctenidial tissue preparations. This study investigated how bivalve molluscs modulate their feeding rates by examining the effects of a variety of neurotransmitters, including serotonin, dopamine, and the dopamine agonist apomorphine on both isolated ctenidial tissue and in intact members of two commercially important bivalve species: the blue mussel, Mytilus edulis; and the bay scallop Argopecten irradians. In particular, we examined the effect of changes in: 1) beat of the lateral cilia (in vitro), 2) distance between ctenidial filaments and/or plicae (in vivo), and 3) diameter of the siphonal openings (in vivo) on alteration of bulk water flow through the mantle cavity. Important differences were found between isolated tissue and whole animals, and between species. Drugs that stimulated ciliary beat in vitro did not increase water processing rate in vivo. None of the treatments increased water flow through the mantle cavity of intact animals. Results suggest that A. irradians was primarily modulating lateral ciliary activity, while M. edulis appeared to have a number of ways to control water processing activity, signifying that the two species may have different compensatory and regulatory mechanisms controlling feeding activity. PMID:25847101

  5. Hypertonicity increases NO production to modulate the firing rate of magnocellular neurons of the supraoptic nucleus of rats.

    PubMed

    da Silva, M P; Ventura, R R; Varanda, W A

    2013-10-10

    Increases in plasma osmolality enhance nitric oxide (NO) levels in magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and modulate the secretion of both vasopressin (VP) and oxytocin (OT). In this paper, we describe the effects of hypertonicity on the electrical properties of MNCs by focusing on the nitrergic modulation of their activity in this condition. Membrane potentials were measured using the patch clamp technique, in the presence of both glutamatergic and GABAergic neurotransmission blockers, in coronal brain slices of male Wistar rats. The recordings were first made under a control condition (295 mosm/kg H2O), then in the presence of a hypertonic stimulus (330 mosm/kg H2O) and, finally, with a hypertonic stimulus plus 500 μM L-Arginine or 100 μM N-nitro-L-Arginine methyl ester hydrochloride (L-NAME). Hypertonicity per se increased the firing frequency of the neurons. L-Arginine prevented the increase in fire frequency induced by hypertonic stimulus, and L-NAME (inhibitor of nitric oxide synthase) induced an additional increase in frequency when applied together with the hypertonic solution. Moreover, L-Arginine hyperpolarizes the resting potential and decreases the peak value of the after-hyperpolarization; both effects were blocked by L-NAME and hypertonicity and/or L-NAME reduced the time constant of the rising phase of the after-depolarization. These results demonstrate that an intrinsic nitrergic system is part of the mechanisms controlling the excitability of MNCs of the SON when the internal fluid homeostasis is disturbed. PMID:23850590

  6. Determination of the rate of rapid lipid transfer induced by poly(ethylene glycol) using the SLM Fourier transform phase and modulation spectrofluorometer.

    PubMed

    Burgess, S W; Wu, J R; Swift, K; Lentz, B R

    1991-06-01

    Rate constants were determined for the transfer of the fluorescent lipid probe 1-palmitoyl-2-[[2-[4-(6-phenyl-trans-1,3,5-hexatrienyl)phenyl]ethyl] oxy]carbonyl]-3-sn-phosphatidylcholine (DPHpPC) between large, unilamellar extrusion vesicles composed either of dipalmitoyl phosphatidylcholine (DPPC) or of DPPC mixed with a small amount (0.5 mol%) of lyso phosphatidylcholine (Lyso PC). Transfer of the lipid probe in the presence of varying concentrations of poly(ethylene glycol) (PEG) was monitored using the SLM 48000-MHF Multi-Harmonic Fourier Transform phase and modulation spectrofluorometer to collect multifrequency phase and modulation fluorescence data sets on a subsecond time scale. The unique ability of this instrument to yield accurate fluorescence lifetime data on this time scale allowed transfer to be detected in terms of a time-dependent change in the fluorescent lifetime distribution associated with the lipid-like DPHpPC probe. This probe demonstrates two short fluoresence decay times (ca. 1.1-1.4 and 4.3-4.8 ns) in a probe-rich environment but a single long lifetime (ca. 7 ns) in a probe-poor environment. A simple two-state model for initial lipid transfer was used to analyze the multifrequency data sets collected over a 4-s time frame to obtain the time rate of change of the concentrations of donor and acceptor probe populations following rapid mixing of vesicles with PEG. The ability to measure fluorescence lifetimes on this time scale has allowed us to show that the of rate of lipid transfer increased dramatically at 35% PEG in both fusing and nonfusing vesicle systems. These results are interpreted in terms of a distinct interbilayer structure associated with intimate bilayer contact induced by high and potentially fusogenic concentrations of PEG. PMID:24242960

  7. RGS6, but Not RGS4, Is the Dominant Regulator of G Protein Signaling (RGS) Modulator of the Parasympathetic Regulation of Mouse Heart Rate*

    PubMed Central

    Wydeven, Nicole; Posokhova, Ekaterina; Xia, Zhilian; Martemyanov, Kirill A.; Wickman, Kevin

    2014-01-01

    Parasympathetic activity decreases heart rate (HR) by inhibiting pacemaker cells in the sinoatrial node (SAN). Dysregulation of parasympathetic influence has been linked to sinus node dysfunction and arrhythmia. RGS (regulator of G protein signaling) proteins are negative modulators of the parasympathetic regulation of HR and the prototypical M2 muscarinic receptor (M2R)-dependent signaling pathway in the SAN that involves the muscarinic-gated atrial K+ channel IKACh. Both RGS4 and RGS6-Gβ5 have been implicated in these processes. Here, we used Rgs4−/−, Rgs6−/−, and Rgs4−/−:Rgs6−/− mice to compare the relative influence of RGS4 and RGS6 on parasympathetic regulation of HR and M2R-IKACh-dependent signaling in the SAN. In retrogradely perfused hearts, ablation of RGS6, but not RGS4, correlated with decreased resting HR, increased heart rate variability, and enhanced sensitivity to the negative chronotropic effects of the muscarinic agonist carbachol. Similarly, loss of RGS6, but not RGS4, correlated with enhanced sensitivity of the M2R-IKACh signaling pathway in SAN cells to carbachol and a significant slowing of M2R-IKACh deactivation rate. Surprisingly, concurrent genetic ablation of RGS4 partially rescued some deficits observed in Rgs6−/− mice. These findings, together with those from an acute pharmacologic approach in SAN cells from Rgs6−/− and Gβ5−/− mice, suggest that the partial rescue of phenotypes in Rgs4−/−:Rgs6−/− mice is attributable to another R7 RGS protein whose influence on M2R-IKACh signaling is masked by RGS4. Thus, RGS6-Gβ5, but not RGS4, is the primary RGS modulator of parasympathetic HR regulation and SAN M2R-IKACh signaling in mice. PMID:24318880

  8. High accuracy optical rate sensor

    NASA Technical Reports Server (NTRS)

    Uhde-Lacovara, J.

    1990-01-01

    Optical rate sensors, in particular CCD arrays, will be used on Space Station Freedom to track stars in order to provide inertial attitude reference. An algorithm to provide attitude rate information by directly manipulating the sensor pixel intensity output is presented. The star image produced by a sensor in the laboratory is modeled. Simulated, moving star images are generated, and the algorithm is applied to this data for a star moving at a constant rate. The algorithm produces accurate derived rate of the above data. A step rate change requires two frames for the output of the algorithm to accurately reflect the new rate. When zero mean Gaussian noise with a standard deviation of 5 is added to the simulated data of a star image moving at a constant rate, the algorithm derives the rate with an error of 1.9 percent at a rate of 1.28 pixels per frame.

  9. Modulation of internal conversion rate and nonlinear absorption in meso-tetraphenylporphyrins by donor/acceptor substitutes

    NASA Astrophysics Data System (ADS)

    Ao, Guanghong; Qian, Xuemin; Xiao, Zhengguo; Li, Zhongguo; Nie, Zhongquan; Wang, Yuxiao; Zhang, Xueru; Song, Yinglin

    2015-08-01

    Meso-tetraphenylporphyrin (TPP), (meso-tetrakis(4-cyanophenyl)porphyrin [TPP(CN)4)] and (meso-tetrakis(4-methoxyphenyl)porphyrin [TPP(OMe)4]) are synthesized. The donor methoxy substitute (OMe) and acceptor cyano substitute (CN) are introduced into TPP in order to examine their influence on the photophysical properties of TPP. The nonlinear absorption properties of these three porphyrins are studied using open-aperture Z-scan and time-resolved pump-probe techniques in picosecond and nanosecond regimes, and the results are elucidated successfully by a five-level model. As compared to TPP, TPP(OMe)4 exhibits an accelerated internal conversion from S1 to S0 state (0.02 ns), and S1 to T1 state (0.03 ns). Moreover, a changeover from saturable absorption to reverse saturable absorption is observed in TPP(OMe)4 in the ps regime. Whereas the nonlinear absorption behavior of TPP(CN)4 is similar to that of TPP. The results imply that these two substituents, especially the OMe group, could modulate the photophysical properties of TPP, which may provide a useful option for porphyrin-related applications.

  10. A New Paradigm for Gamma Ray Bursts: Long Term Accretion Rate Modulation by an External Accretion Disk

    NASA Technical Reports Server (NTRS)

    Cannizzo, John; Gehrels, Neil

    2009-01-01

    We present a new way of looking at the very long term evolution of GRBs in which the disk of material surrounding the putative black hole powering the GRB jet modulates the mass flow, and hence the efficacy of the process that extracts rotational energy from the black hole and inner accretion disk. The pre-Swift paradigm of achromatic, shallow-to-steep "breaks" in the long term GRB light curves has not been borne out by detailed Swift data amassed in the past several years. We argue that, given the initial existence of a fall-back disk near the progenitor, an unavoidable consequence will be the formation of an "external disk" whose outer edge continually moves to larger radii due to angular momentum transport and lack of a confining torque. The mass reservoir at large radii moves outward with time and gives a natural power law decay to the GRB light curves. In this model, the different canonical power law decay segments in the GRB identified by Zhang et al. and Nousek et al. represent different physical states of the accretion disk. We identify a physical disk state with each power law segment.

  11. A NEW PARADIGM FOR GAMMA-RAY BURSTS: LONG-TERM ACCRETION RATE MODULATION BY AN EXTERNAL ACCRETION DISK

    SciTech Connect

    Cannizzo, J. K. E-mail: gehrels@milkyway.gsfc.nasa.gov

    2009-08-01

    We present a new way of looking at the very long-term evolution of gamma-ray bursts (GRBs) in which the disk of material surrounding the putative black hole powering the GRB jet modulates the mass flow, and hence the efficacy of the process that extracts rotational energy from the black hole and inner accretion disk. The pre-Swift paradigm of achromatic, shallow-to-steep 'breaks' in the long-term GRB light curves has not been borne out by detailed Swift data amassed in the past several years. We argue that, given the initial existence of a fall-back disk near the progenitor, an unavoidable consequence will be the formation of an 'external disk' whose outer edge continually moves to larger radii due to angular momentum transport and lack of a confining torque. The mass reservoir at large radii moves outward with time and gives a natural power-law decay to the GRB light curves. In this model, the different canonical power-law decay segments in the GRB identified by Zhang et al. and Nousek et al. represent different physical states of the accretion disk. We identify a physical disk state with each power-law segment.

  12. National Utility Rate Database: Preprint

    SciTech Connect

    Ong, S.; McKeel, R.

    2012-08-01

    When modeling solar energy technologies and other distributed energy systems, using high-quality expansive electricity rates is essential. The National Renewable Energy Laboratory (NREL) developed a utility rate platform for entering, storing, updating, and accessing a large collection of utility rates from around the United States. This utility rate platform lives on the Open Energy Information (OpenEI) website, OpenEI.org, allowing the data to be programmatically accessed from a web browser, using an application programming interface (API). The semantic-based utility rate platform currently has record of 1,885 utility rates and covers over 85% of the electricity consumption in the United States.

  13. Impact of dose rate on accuracy of intensity modulated radiation therapy plan delivery using the pretreatment portal dosimetry quality assurance and setting up the workflow at hospital levels

    PubMed Central

    Kaviarasu, Karunakaran; Raj, N. Arunai Nambi; Murthy, K. Krishna; Babu, A. Ananda Giri; Prasad, Bhaskar Laxman Durga

    2015-01-01

    The aim of this study was to examine the impact of dose rate on accuracy of intensity modulated radiation therapy (IMRT) plan delivery by comparing the gamma agreement between the calculated and measured portal doses by pretreatment quality assurance (QA) using electronic portal imaging device dosimetry and creating a workflow for the pretreatment IMRT QA at hospital levels. As the improvement in gamma agreement leads to increase in the quality of IMRT treatment delivery, gamma evaluation was carried out for the calculated and the measured portal images for the criteria of 3% dose difference and 3 mm distance-to-agreement (DTA). Three gamma parameters: Maximum gamma, average gamma, and percentage of the field area with a gamma value>1.0 were analyzed. Three gamma index parameters were evaluated for 40 IMRT plans (315 IMRT fields) which were calculated for 400 monitor units (MU)/min dose rate and maximum multileaf collimator (MLC) speed of 2.5 cm/s. Gamma parameters for all 315 fields are within acceptable limits set at our center. Further, to improve the gamma results, we set an action level for this study using the mean and standard deviation (SD) values from the 315 fields studied. Forty out of 315 IMRT fields showed low gamma agreement (gamma parameters>2 SD as per action level of the study). The parameters were recalculated and reanalyzed for the dose rates of 300, 400 and 500 MU/min. Lowering the dose rate helped in getting an enhanced gamma agreement between the calculated and measured portal doses of complicated fields. This may be attributed to the less complex motion of MLC over time and the MU of the field/segment. An IMRT QA work flow was prepared which will help in improving the quality of IMRT delivery. PMID:26865759

  14. Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats.

    PubMed

    Shankaran, Mahalakshmi; Shearer, Todd W; Stimpson, Stephen A; Turner, Scott M; King, Chelsea; Wong, Po-Yin Anne; Shen, Ying; Turnbull, Philip S; Kramer, Fritz; Clifton, Lisa; Russell, Alan; Hellerstein, Marc K; Evans, William J

    2016-03-15

    Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167-201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated (r(2) = 0.90-0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM. PMID:26714847

  15. Minimizing Variation in Outdoor CPV Power Ratings (Presentation)

    SciTech Connect

    Muller, M.

    2011-02-01

    Module data from NREL's CPV test bed is used to examine methods for calculating outdoor CPV power ratings. IEC 62670 and ASTM E2527 are used as a starting point for determining a module power rating on a monthly basis. Monthly power ratings vary by more than desired using existing methods. The presentation examines modifications to existing methods as well as spectral corrections to reduce variation in monthly module power ratings.

  16. All about Heart Rate (Pulse)

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More All About Heart Rate (Pulse) Updated:Apr 19,2016 ... Sodium and Salt 3 Low Blood Pressure 4 All About Heart Rate (Pulse) 5 How to Eat ...

  17. Breast Cancer Rates by State

    MedlinePlus

    ... Associated Lung Ovarian Prostate Skin Uterine Cancer Home Breast Cancer Rates by State Language: English Español (Spanish) Recommend ... from breast cancer each year. Rates of Getting Breast Cancer by State The number of people who get ...

  18. Lung Cancer Rates by State

    MedlinePlus

    ... HPV-Associated Ovarian Prostate Skin Uterine Cancer Home Lung Cancer Rates by State Language: English Español (Spanish) ... incidence data are currently available. Rates of Getting Lung Cancer by State The number of people who ...

  19. Criteria for Establishing Bond Ratings.

    ERIC Educational Resources Information Center

    Ackerman, Freda Stern

    1984-01-01

    An executive of Moody's Investors Service explains what past experience has taught the company about municipal analysis, how a bond issue is assigned a credit rating, and what issuers can do to obtain the best rating. (MLF)

  20. 2007 Wholesale Power Rate Schedules : 2007 General Rate Schedule Provisions.

    SciTech Connect

    United States. Bonneville Power Administration.

    2006-11-01

    This schedule is available for the contract purchase of Firm Power to be used within the Pacific Northwest (PNW). Priority Firm (PF) Power may be purchased by public bodies, cooperatives, and Federal agencies for resale to ultimate consumers, for direct consumption, and for Construction, Test and Start-Up, and Station Service. Rates in this schedule are in effect beginning October 1, 2006, and apply to purchases under requirements Firm Power sales contracts for a three-year period. The Slice Product is only available for public bodies and cooperatives who have signed Slice contracts for the FY 2002-2011 period. Utilities participating in the Residential Exchange Program (REP) under Section 5(c) of the Northwest Power Act may purchase Priority Firm Power pursuant to the Residential Exchange Program. Rates under contracts that contain charges that escalate based on BPA's Priority Firm Power rates shall be based on the three-year rates listed in this rate schedule in addition to applicable transmission charges. This rate schedule supersedes the PF-02 rate schedule, which went into effect October 1, 2001. Sales under the PF-07 rate schedule are subject to BPA's 2007 General Rate Schedule Provisions (2007 GRSPs). Products available under this rate schedule are defined in the 2007 GRSPs. For sales under this rate schedule, bills shall be rendered and payments due pursuant to BPA's 2007 GRSPs and billing process.

  1. Idiot savants: rate of incidence.

    PubMed

    Hill, A L

    1977-02-01

    Based on the replies to a survey of 300 public residential facilities for the mentally retarded, an incidence rate for idiot savants was established. This rate of .06% is based on the reporting of 54 idiot savants within a population of 90,000 residents. Several reasons for caution in the acceptance of this incidence rate are discussed. PMID:840586

  2. 78 FR 62712 - Rate Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Rate Adjustment AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: The Commission is noticing a recent Postal Service filing seeking postal rate adjustments based on exigent circumstances... On September 26, 2013, the Postal Service filed an exigent rate request with the Commission...

  3. Stocking Rates for Horse Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decision on which stocking rate to graze a horse pasture is critical, particularly if the forage is expected to meet the nutrient needs of the horses. Challenges and management for targeting the optimum stocking rate, defined as the stocking rate that allows forage consumption to approximately equ...

  4. 75 FR 44807 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... COMMISSION Fee Rate AGENCY: National Indian Gaming Commission. ACTION: Notice. SUMMARY: Notice is hereby... annual fee rates of 0.00% for tier 1 and 0.060% (.00060) for tier 2 for calendar year 2010. These rates... Commission. If a tribe has a certificate of self-regulation under 25 CFR part 518, the preliminary fee...

  5. AGRICULTURAL EXCHANGE RATE DATA SHEET

    EPA Science Inventory

    The ERS data set contains annual and monthly data for exchange rates important to U.S. agriculture. It includes both nominal and real exchange rates for 80 countries (plus the European Union) as well as real trade-weighted exchange rate indexes for many commodities and aggregatio...

  6. MEMS Rate Sensors for Space

    NASA Technical Reports Server (NTRS)

    Gambino, Joel P.

    1999-01-01

    Micromachined Electro Mechanical System Rate sensors offer many advantages that make them attractive for space use. They are smaller, consume less power, and cost less than the systems currently available. MEMS Rate Sensors however, have not been optimized for use on spacecraft. This paper describes an approach to developing MEMS Rate Sensors systems for space use.

  7. [Rate Justification for Child Care.

    ERIC Educational Resources Information Center

    Community Coordinated Child Care (4-C) for Central Florida, Inc., Orlando.

    This brief report argues against the cost analysis process currently used as a form of rate justification by states and central agencies who are purchasing child care. Instead, a logic is proposed for negotiated rates based on expected levels of necessary costs and reasonable rates in comparison with open market levels as shown on day care…

  8. Rate and Occupancy Survey Results.

    ERIC Educational Resources Information Center

    Mid-Atlantic Association of Coll. and Univ. Housing Officers.

    In its annual effort to determine rate and occupancy trends in the Mid-Atlantic region, MACUHO surveyed by questionnaire the chief housing officers on its mailing list and received 99 usable responses, compared with 65 the previous year. The average double room rate was reported to be $691, compared with $646 in 1975; the average board rate rose…

  9. Dose rate mapping of VMAT treatments.

    PubMed

    Podesta, Mark; Popescu, I Antoniu; Verhaegen, Frank

    2016-06-01

    Human tissues exhibit a varying response to radiation dose depending on the dose rate and fractionation scheme used. Dose rate effects have been reported for different radiations, and tissue types. The literature indicates that there is not a significant difference in response for low-LET radiation when using dose rates between 1 Gy min(-1) and 12 Gy min(-1) but lower dose rates have an observable sparing effect on tissues and a differential effect between tissues. In intensity-modulated radiotherapy such as volumetric modulated arc therapy (VMAT) the dose can be delivered with a wide range of dose rates. In this work we developed a method based on time-resolved Monte Carlo simulations to quantify the dose rate frequency distribution for clinical VMAT treatments for three cancer sites, head and neck, lung, and pelvis within both planning target volumes (PTV) and normal tissues. The results show a wide range of dose rates are used to deliver dose in VMAT and up to 75% of the PTV can have its dose delivered with dose rates  <1 Gy min(-1). Pelvic plans on average have a lower mean dose rate within the PTV than lung or head and neck plans but a comparable mean dose rate within the organs at risk. Two VMAT plans that fulfil the same dose objectives and constraints may be delivered with different dose rate distributions, particularly when comparing single arcs to multiple arc plans. It is concluded that for dynamic plans, the dose rate range used varies to a larger degree than previously assumed. The effect of the dose rate range in VMAT on clinical outcome is unknown. PMID:27164221

  10. Dose rate mapping of VMAT treatments

    NASA Astrophysics Data System (ADS)

    Podesta, Mark; Antoniu Popescu, I.; Verhaegen, Frank

    2016-06-01

    Human tissues exhibit a varying response to radiation dose depending on the dose rate and fractionation scheme used. Dose rate effects have been reported for different radiations, and tissue types. The literature indicates that there is not a significant difference in response for low-LET radiation when using dose rates between 1 Gy min‑1 and 12 Gy min‑1 but lower dose rates have an observable sparing effect on tissues and a differential effect between tissues. In intensity-modulated radiotherapy such as volumetric modulated arc therapy (VMAT) the dose can be delivered with a wide range of dose rates. In this work we developed a method based on time-resolved Monte Carlo simulations to quantify the dose rate frequency distribution for clinical VMAT treatments for three cancer sites, head and neck, lung, and pelvis within both planning target volumes (PTV) and normal tissues. The results show a wide range of dose rates are used to deliver dose in VMAT and up to 75% of the PTV can have its dose delivered with dose rates  <1 Gy min‑1. Pelvic plans on average have a lower mean dose rate within the PTV than lung or head and neck plans but a comparable mean dose rate within the organs at risk. Two VMAT plans that fulfil the same dose objectives and constraints may be delivered with different dose rate distributions, particularly when comparing single arcs to multiple arc plans. It is concluded that for dynamic plans, the dose rate range used varies to a larger degree than previously assumed. The effect of the dose rate range in VMAT on clinical outcome is unknown.

  11. Relaxed Poisson cure rate models.

    PubMed

    Rodrigues, Josemar; Cordeiro, Gauss M; Cancho, Vicente G; Balakrishnan, N

    2016-03-01

    The purpose of this article is to make the standard promotion cure rate model (Yakovlev and Tsodikov, ) more flexible by assuming that the number of lesions or altered cells after a treatment follows a fractional Poisson distribution (Laskin, ). It is proved that the well-known Mittag-Leffler relaxation function (Berberan-Santos, ) is a simple way to obtain a new cure rate model that is a compromise between the promotion and geometric cure rate models allowing for superdispersion. So, the relaxed cure rate model developed here can be considered as a natural and less restrictive extension of the popular Poisson cure rate model at the cost of an additional parameter, but a competitor to negative-binomial cure rate models (Rodrigues et al., ). Some mathematical properties of a proper relaxed Poisson density are explored. A simulation study and an illustration of the proposed cure rate model from the Bayesian point of view are finally presented. PMID:26686485

  12. Comparison on the sensitivity of fiber optic SONET OC-48 PIN-TIA receivers measured by using synchronous modulation intermixing technique and bit-error-rate tester

    NASA Astrophysics Data System (ADS)

    Lin, Gong-Ru; Liao, Yu-Sheng

    2004-04-01

    The sensitivity of SONET p-i-n photodiode receivers with transimpedance amplifier (PIN-TIA) from OC-3 to OC-48 data rates measured by using a standard bit-error-rate tester (BERT) and a novel synchronous-modulation inter-mixing (SMIM) technique are compared. A threshold inter-mixed voltage of below 15.8 mV obtained by SMIM method corresponding to the sensitivity of PIN-TIA receiver beyond -32 dBm determined by BERT for the SONET OC-48 PIN-TIA receivers with a required BER of better than 10-10 is reported. the analysis interprets that the inter-mixed voltage for improving the PIN-TIA receiver sensitivity from -31 dBm to -33 dBm has to be increased from 12.5 mV to 20.4 mV. As compared to the BERT, the SMIM is a relatively simplified and low-cost technique for on-line mass-production diagnostics for measureing the sensitivity and evaluationg the BER performances of PIN-TIA receivers.

  13. Uncertainty Analysis for Photovoltaic Degradation Rates (Poster)

    SciTech Connect

    Jordan, D.; Kurtz, S.; Hansen, C.

    2014-04-01

    Dependable and predictable energy production is the key to the long-term success of the PV industry. PV systems show over the lifetime of their exposure a gradual decline that depends on many different factors such as module technology, module type, mounting configuration, climate etc. When degradation rates are determined from continuous data the statistical uncertainty is easily calculated from the regression coefficients. However, total uncertainty that includes measurement uncertainty and instrumentation drift is far more difficult to determine. A Monte Carlo simulation approach was chosen to investigate a comprehensive uncertainty analysis. The most important effect for degradation rates is to avoid instrumentation that changes over time in the field. For instance, a drifting irradiance sensor, which can be achieved through regular calibration, can lead to a substantially erroneous degradation rates. However, the accuracy of the irradiance sensor has negligible impact on degradation rate uncertainty emphasizing that precision (relative accuracy) is more important than absolute accuracy.

  14. Saturn component failure rate and failure rate modifiers

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Failure mode frequency ratios, environmental adjustment factors, and failure rates for mechanical and electromechanical component families are presented. The failure rates and failure rate modifiers resulted from a series of studies whose purpose was to provide design, tests, reliability, and systems engineers with accurate, up-to-date failure rate information. The results of the studies were achieved through an extensive engineering analysis of the Saturn Program test data and Unsatisfactory Condition Reports (UCR's) and the application of mathematical techniques developed for the studies.

  15. High data rate systems for the future

    NASA Technical Reports Server (NTRS)

    Chitwood, John

    1991-01-01

    Information systems in the next century will transfer data at rates that are much greater than those in use today. Satellite based communication systems will play an important role in networking users. Typical data rates; use of microwave, millimeter wave, or optical systems; millimeter wave communication technology; modulators/exciters; solid state power amplifiers; beam waveguide transmission systems; low noise receiver technology; optical communication technology; and the potential commercial applications of these technologies are discussed.

  16. Calibration and Rating of Photovoltaics: Preprint

    SciTech Connect

    Emery, K.

    2012-06-01

    Rating the performance of photovoltaic (PV) modules is critical to determining the cost per watt, and efficiency is useful to assess the relative progress among PV concepts. Procedures for determining the efficiency for PV technologies from 1-sun to low concentration to high concentration are discussed. We also discuss the state of the art in primary and secondary calibration of PV reference cells used by calibration laboratories around the world. Finally, we consider challenges to rating PV technologies and areas for improvement.

  17. Field measurement of ventilation rates.

    PubMed

    Persily, A K

    2016-02-01

    Ventilation rates have significant impacts on building energy use and indoor contaminant concentrations, making them key parameters in building performance. Ventilation rates have been measured in buildings for many decades, and there are mature measurement approaches available to researchers and others who need to know actual ventilation rates in buildings. Despite the fact that ventilation rates are critical in interpreting indoor concentration measurements, it is disconcerting how few Indoor Air Quality field studies measure ventilation rates or otherwise characterize the ventilation design of the study building(s). This paper summarizes parameters of interest in characterizing building ventilation, available methods for quantifying these parameters, and challenges in applying these methods to different types of buildings and ventilation systems. These parameters include whole-building air change rates, system outdoor air intake rates, and building infiltration rates. Tracer gas methods are reviewed as well as system airflow rate measurements using, for example, duct traverses. Several field studies of ventilation rates conducted over the past 75 years are described to highlight the approaches employed and the findings obtained. PMID:25689218

  18. 9 CFR 592.520 - Overtime rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. FSIS calculates the benefits rate, the travel and operating rate, the overhead rate, and the allowance for bad...

  19. 9 CFR 592.520 - Overtime rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. FSIS calculates the benefits rate, the travel and operating rate, the overhead rate, and the allowance for bad...

  20. 9 CFR 592.530 - Holiday rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., plus the travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. FSIS calculates the benefits rate, the travel and operating rate, the overhead rate, and the allowance for...

  1. 9 CFR 592.530 - Holiday rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., plus the travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. FSIS calculates the benefits rate, the travel and operating rate, the overhead rate, and the allowance for...

  2. 15 CFR 700.3 - Priority ratings and rated orders.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Priority ratings and rated orders. 700.3 Section 700.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL...

  3. Conducting Market Rate Surveys and Establishing Rate Policies.

    ERIC Educational Resources Information Center

    Karolak, Eric; Collins, Ray; Stoney, Louise

    Market rate surveys and the rate-setting policies and reimbursement rules informed by them are at the core of the market-based approach to child care and are central to the delicate balancing act of ensuring access to subsidized care while at the same time promoting the quality of child care. This report provides an overview of the market-based…

  4. HEATCVB: Coronal heating rate approximations

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.

    2015-06-01

    HEATCVB is a stand-alone Fortran 77 subroutine that estimates the local volumetric coronal heating rate with four required inputs: the radial distance r, the wind speed u, the mass density ρ, and the magnetic field strength |B0|. The primary output is the heating rate Qturb at the location defined by the input parameters. HEATCVB also computes the local turbulent dissipation rate of the waves, γ = Qturb/(2UA).

  5. Relation between gastric emptying rate and rate of intraluminal lipolysis.

    PubMed

    Maes, B D; Ghoos, Y F; Geypens, B J; Hiele, M I; Rutgeerts, P J

    1996-01-01

    The variable gastric emptying rate of a test meal is one of the major problems in evaluating accurately gastrointestinal physiological functions beyond the stomach. The aim of this study was to evaluate the effect of the gastric emptying rate on the rate of intraluminal lipolysis. Thirty four subjects without pancreatic disease (21 with a normal gastric emptying and 13 with a known slow gastric emptying) and 14 subjects with pancreatic disease (four without and 10 with pancreatic insufficiency) were studied using a dual labelled breath test. The test meal consisted of one egg, 60 grams of white bread, 10 grams of margarine, and 150 ml of water (350 kcal). The egg yolk was labelled with 91 mg of 13C-octanoic acid, the margarine was labelled with 296 kBq of distearyl-2-14C-octanoyl-glycerol. Breath samples were taken every 15 minutes during six hours and analysed for 13CO2 and 14CO2 content. The gastric emptying rate of the meal was evaluated by the gastric emptying coefficient, the half emptying time, and the lag phase; the rate of intraluminal lipolysis was evaluated by the six hours cumulative 14CO2 excretion. Despite a clear distinction in the rate of intraluminal lipolysis, no difference could be detected in gastric emptying rate of the test meal between subjects without and with pancreatic disease. In subjects with pancreatic insufficiency, intraluminal hydrolysis was the rate limiting process in fat assimilation; in patients without pancreatic insufficiency, however, gastric emptying could be rate limiting. Therefore, patients with known slow gastric emptying, displayed a significantly decreased rate of intraluminal lipolysis compared with normal controls. This decrease could be corrected for accurately using a correction factor based on the gastric emptying coefficient. In conclusion, the combined 13C-octanoic acid and 14C-mixed triglyceride breath test permits the measurement of gastric emptying rate and intraluminal lipolysis simultaneously in a minimally

  6. Assessing dose rate distributions in VMAT plans

    NASA Astrophysics Data System (ADS)

    Mackeprang, P.-H.; Volken, W.; Terribilini, D.; Frauchiger, D.; Zaugg, K.; Aebersold, D. M.; Fix, M. K.; Manser, P.

    2016-04-01

    Dose rate is an essential factor in radiobiology. As modern radiotherapy delivery techniques such as volumetric modulated arc therapy (VMAT) introduce dynamic modulation of the dose rate, it is important to assess the changes in dose rate. Both the rate of monitor units per minute (MU rate) and collimation are varied over the course of a fraction, leading to different dose rates in every voxel of the calculation volume at any point in time during dose delivery. Given the radiotherapy plan and machine specific limitations, a VMAT treatment plan can be split into arc sectors between Digital Imaging and Communications in Medicine control points (CPs) of constant and known MU rate. By calculating dose distributions in each of these arc sectors independently and multiplying them with the MU rate, the dose rate in every single voxel at every time point during the fraction can be calculated. Independently calculated and then summed dose distributions per arc sector were compared to the whole arc dose calculation for validation. Dose measurements and video analysis were performed to validate the calculated datasets. A clinical head and neck, cranial and liver case were analyzed using the tool developed. Measurement validation of synthetic test cases showed linac agreement to precalculated arc sector times within  ±0.4 s and doses  ±0.1 MU (one standard deviation). Two methods for the visualization of dose rate datasets were developed: the first method plots a two-dimensional (2D) histogram of the number of voxels receiving a given dose rate over the course of the arc treatment delivery. In similarity to treatment planning system display of dose, the second method displays the dose rate as color wash on top of the corresponding computed tomography image, allowing the user to scroll through the variation over time. Examining clinical cases showed dose rates spread over a continuous spectrum, with mean dose rates hardly exceeding 100 cGy min-1 for conventional

  7. Rate control in atrial fibrillation.

    PubMed

    Van Gelder, Isabelle C; Rienstra, Michiel; Crijns, Harry J G M; Olshansky, Brian

    2016-08-20

    Control of the heart rate (rate control) is central to atrial fibrillation management, even for patients who ultimately require control of the rhythm. We review heart rate control in patients with atrial fibrillation, including the rationale for the intervention, patient selection, and the treatments available. The choice of rate control depends on the symptoms and clinical characteristics of the patient, but for all patients with atrial fibrillation, rate control is part of the management. Choice of drugs is patient-dependent. β blockers, alone or in combination with digoxin, or non-dihydropyridine calcium-channel blockers (not in heart failure) effectively lower the heart rate. Digoxin is least effective, but a reasonable choice for physically inactive patients aged 80 years or older, in whom other treatments are ineffective or are contraindicated, and as an additional drug to other rate-controlling drugs, especially in heart failure when instituted cautiously. Atrioventricular node ablation with pacemaker insertion for rate control should be used as an approach of last resort but is also an option early in the management of patients with atrial fibrillation treated with cardiac resynchronisation therapy. However, catheter ablation of atrial fibrillation should be considered before atrioventricular node ablation. Although rate control is a top priority and one of the first management issues for all patients with atrial fibrillation, many issues remain. PMID:27560277

  8. Mortality rates decline in Malaysia.

    PubMed

    1991-11-01

    Experiencing remarkable decreases in mortality rates over the past 3 decades, Malaysia currently has one of the lowest mortality rates among developing countries, a rate that compares favorably with those of developed countries. Between 1957 and 1989, the crude death rate dropped from 12.4/1000 population to 4.6. Over the same period, Malaysia recorded even greater decreases in the infant mortality rate, from 75.5/1000 births to 15.2. The Maternal mortality rate also declined from 1.48 in 1970 to 0.24 in 1988. The data indicates that mortality rates vary from state to state, and that rural areas have a higher mortality than urban areas. According to a study by the National Population and Family Development Board, the use of maternal and child health services has played an important role in reducing neonatal, perinatal, infant, child, and maternal mortality rates. Nearly all women in Malaysia receive antenatal services. While the country has achieved great gains on mortality rates, programs focusing on specific age and socioeconomic groups could lead to even greater reductions. The Minister for National Unity and Social Development, Dato Napsiah Omar, has called for the development of programs designed to improve the population's quality of life. PMID:12284509

  9. Basalt Weathering Rates Across Scales

    NASA Astrophysics Data System (ADS)

    Navarresitchler, A.; Brantley, S.

    2006-12-01

    Weathering of silicate minerals is a known sink for atmospheric CO2. An estimated 30%-35% of the consumption of CO2 from continental silicate weathering can be attributed to basalt weathering (Dessert et al., 2003). To assess basalt weathering rates we examine weathering advance rates of basalt (w, mm/yr) reported at four scales: denudation rates from basalt watersheds (tens of kilometers), rates of soil formation from soil profiles developed on basaltic parent material of known age (meters), rates of weathering rind formation on basalt clasts (centimeters), and laboratory dissolution rates (millimeters). Basalt weathering advance rates calculated for watersheds range between 0.36 and 9.8x10-3 mm/yr. The weathering advance rate for a basalt soil profile in Hawaii is 8.0x10-3 mm/yr while advance rates for clasts range from 5.6x10-6 to 2.4x10-4 mm/yr. Batch and mixed flow laboratory experiments performed at circum- neutral pH yield advance rates of 2.5x10^{-5} to 3.4x10-7 mm/yr when normalized to BET surface area. These results show increasing advance rates with both increasing scale (from laboratory to watersheds) and increasing temperature. If we assume that basalt weathers at an intrinsic rate that applies to all scales then we conclude that variations in weathering advance rates arise from variations in surface area measurement at different scales (D); therefore, basalt weathering is a fractal system. We measure a fractal dimension (dr) of basalt weathering of 2.2. For Euclidean geometries, measured surface area does not vary with the scale at which it is measured and dr equals 2. For natural surfaces, surface area is related to the scale at which it is measured. As scale increases, the minimum size of the surface irregularities that are measurable also increases. The ratio between BET and geometric normalized laboratory dissolution rates has been defined as a roughness parameter, λ, which ranges from ~10-100. We extend the definition of this roughness parameter

  10. Heart Rate and Respiratory Rate Influence on Heart Rate Variability Repeatability: Effects of the Correction for the Prevailing Heart Rate

    PubMed Central

    Gąsior, Jakub S.; Sacha, Jerzy; Jeleń, Piotr J.; Zieliński, Jakub; Przybylski, Jacek

    2016-01-01

    Background: Since heart rate variability (HRV) is associated with average heart rate (HR) and respiratory rate (RespRate), alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate. Methods: Forty healthy volunteers underwent two ECG examinations 7 days apart. Standard HRV indices were calculated from 5-min ECG recordings. The ECG-derived respiration signal was estimated to assess RespRate. To investigate HR impact on HRV, HRV parameters were corrected for prevailing HR. Results: Differences in HRV parameters between the measurements were associated with the changes in HR and RespRate. However, in multiple regression analysis only HR alteration proved to be independent determinant of the HRV differences—every change in HR by 1 bpm changed HRV values by 16.5% on average. After overall removal of HR impact on HRV, coefficients of variation of the HRV parameters significantly dropped on average by 26.8% (p < 0.001), i.e., by the same extent HRV reproducibility improved. Additionally, the HRV correction for HR decreased association between RespRate and HRV. Conclusions: In stable conditions, HR but not RespRate is the most powerful factor determining HRV reproducibility and even a minimal change of HR may considerably alter HRV. However, the removal of HR impact may significantly improve HRV repeatability. The association between HRV and RespRate seems to be, at least in part, HR dependent. PMID:27588006

  11. Modulation of cardiac contraction, relaxation and rate by the endothelial nitric oxide synthase (eNOS): lessons from genetically modified mice

    PubMed Central

    Massion, P B; Balligand, J-L

    2003-01-01

    The modulatory role of endothelial nitric oxide synthase (eNOS) on heart contraction, relaxation and rate is examined in light of recent studies using genetic deletion or overexpression in mice under specific conditions. Unstressed eNOS-/- hearts in basal conditions exhibit a normal inotropic and lusitropic function, with either decreased or unchanged heart rate. Under stimulation with catecholamines, eNOS-/- mice predominantly show a potentiation in their β-adrenergic inotropic and lusitropic responsiveness. A similar phenotype is observed in β3-adrenoceptor deficient mice, pointing to a key role of this receptor subtype for eNOS coupling. The effect of eNOS on the muscarinic cholinergic modulation of cardiac function probably operates in conjunction with other NO-independent mechanisms, the persistence of which may explain the apparent dispensability of this isoform for the effect of acetylcholine in some eNOS-/- mouse strains. eNOS-/- hearts submitted to short term ischaemia-reperfusion exhibit variable alterations in systolic and diastolic function and infarct size, while those submitted to myocardial infarction present a worsened ventricular remodelling, increased 1 month mortality and loss of benefit from ACE inhibitor or angiotensin II type I receptor antagonist therapy. Although non-conditional eNOS gene deletion may engender phenotypic adaptations (e.g. ventricular hypertrophy resulting from chronic hypertension, or upregulation of the other NOS isoforms) potentially confounding the interpretation of comparative studies, the use of eNOS-/- mice has undoubtedly advanced (and will probably continue to improve) our understanding of the complex role of eNOS (in conjunction with the other NOSs) in the regulation of cardiac function. The challenge is now to confirm the emerging paradigms in human cardiac physiology and hopefully translate them into therapy. PMID:12509479

  12. Improving Completion Rates for TAFE Students.

    ERIC Educational Resources Information Center

    Uren, Judith

    A study examined individual student, institutional, and environmental factors influencing student non-completions and determined strategies that Western Australia's Central TAFE (technical and further education) might introduce to improve student retention. After completing a multivariate analysis of module completion rates, further data for a…

  13. Overview of Field Experience - Degradation Rates & Lifetimes

    SciTech Connect

    Jordan, Dirk; Kurtz, Sarah

    2015-09-14

    The way a PV module fails may depend not only on its design and the materials used in its construction, but also on the weather it experiences, the way it is mounted, and the quality control during its manufacture. This presentation gives an overview of Field Experience - what degradation rates and what lifetimes are being observed in various regions.

  14. H2O2 production rate in Lactobacillus johnsonii is modulated via the interplay of a heterodimeric flavin oxidoreductase with a soluble 28 Kd PAS domain containing protein

    PubMed Central

    Valladares, Ricardo B.; Graves, Christina; Wright, Kaitlyn; Gardner, Christopher L.; Lorca, Graciela L.; Gonzalez, Claudio F.

    2015-01-01

    Host and commensals crosstalk, mediated by reactive oxygen species (ROS), has triggered a growing scientific interest to understand the mechanisms governing such interaction. However, the majority of the scientific studies published do not evaluate the ROS production by commensals bacteria. In this context we recently showed that Lactobacillus johnsonii N6.2, a strain of probiotic value, modulates the activity of the critical enzymes 2,3-indoleamine dioxygenase via H2O2 production. L. johnsonii N6.2 by decreasing IDO activity, is able to modify the tryptophan/kynurenine ratio in the host blood with further systemic consequences. Understanding the mechanisms of H2O2 production is critical to predict the probiotic value of these strains and to optimize bacterial biomass production in industrial processes. We performed a transcriptome analysis to identify genes differentially expressed in L. johnsonii N6.2 cells collected from cultures grown under different aeration conditions. Herein we described the biochemical characteristics of a heterodimeric FMN reductase (FRedA/B) whose in vitro activity is controlled by LjPAS protein with a typical Per-Arnst-Sim (PAS) sensor domain. Interestingly, LjPAS is fused to the FMN reductase domains in other lactobacillaceae. In L. johnsonii, LjPAS is encoded by an independent gene which expression is repressed under anaerobic conditions (>3 fold). Purified LjPAS was able to slow down the FRedA/B initial activity rate when the holoenzyme precursors (FredA, FredB, and FMN) were mixed in vitro. Altogether the results obtained suggest that LjPAS module regulates the H2O2 production helping the cells to minimize oxidative stress in response to environmental conditions. PMID:26236298

  15. Matching and Conditioned Reinforcement Rate

    ERIC Educational Resources Information Center

    Shahan, Timothy A.; Podlesnik, Christopher A.; Jimenez-Gomez, Corina

    2006-01-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative…

  16. Nontraditional Student Graduation Rate Benchmarks

    ERIC Educational Resources Information Center

    Miller, Nathan B.

    2014-01-01

    The prominence of discourse on postsecondary degree completion, student persistence, and retention has increased in the national dialogue. Heightened attention to college completion rates by the federal government and pressure to tie state funding to performance metrics associated with graduation rates are catalysts for the discussion.…

  17. Predicting the Divorce Rate: Down?

    ERIC Educational Resources Information Center

    Kemper, Theodore D.

    1983-01-01

    Predicted a decline in the divorce rate based on 10 factors including: decline in marriage rate, older age at marriage, mental health improvement, upper limit on employed women, less migration, end of the cultural revolution, exhaustion of latency effect of no-fault divorce, and fear of the consequences of divorce. (JAC)

  18. Rating Scale Instruments and Measurement

    ERIC Educational Resources Information Center

    Cavanagh, Robert F.; Romanoski, Joseph T.

    2006-01-01

    The article examines theoretical issues associated with measurement in the human sciences and ensuring data from rating scale instruments are measures. An argument is made that using raw scores from rating scale instruments for subsequent arithmetic operations and applying linear statistics is less preferable than using measures. These theoretical…

  19. 76 FR 46603 - Security Ratings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-03

    ... COMMISSION 17 CFR Parts 200, 229, 230, 232, 239, 240, and 249 RIN 3235-AK18 Security Ratings AGENCY... for, security ratings (for example, Forms S-3 and F-3 eligibility criteria) with alternative...- worthiness of a security or money market instrument and any references to or requirements in such...

  20. Depression Rating Scale for Children.

    ERIC Educational Resources Information Center

    Poznanski, Elva O.; And Others

    1979-01-01

    A Children's Depression Rating Scale (CDRS) was devised and tested on 30 inpatient children (6 to 12 years old) in a medical hospital. A high correlation was found between global ratings by two psychiatrists of severity of depression and scores on the CDRS. Journal availability: American Academy of Pediatrics, P.O. Box 1034, Evanston, IL 60204.…

  1. Interest rate swaps under CIR

    NASA Astrophysics Data System (ADS)

    Mallier, R.; Alobaidi, G.

    2004-03-01

    We consider fixed-for-floating interest rate swaps under the assumption that interest rates are given by the mean-reverting Cox-Ingersoll-Ross model. By using a Green's function approach, we derive analytical expressions for the values of both a vanilla swap and an in-arrears swap.

  2. Evolution & the Cesarean Section Rate

    ERIC Educational Resources Information Center

    Walsh, Joseph A.

    2008-01-01

    "Nothing in biology makes sense except in the light of evolution." This was the title of an essay by geneticist Theodosius Dobzhansky writing in 1973. Many causes have been given for the increased Cesarean section rate in developed countries, but biologic evolution has not been one of them. The C-section rate will continue to rise, because the…

  3. National anthems and suicide rates.

    PubMed

    Lester, David; Gunn, John F

    2011-02-01

    In a sample of 18 European nations, suicide rates were positively associated with the proportion of low notes in the national anthems and, albeit less strongly, with students' ratings of how gloomy and how sad the anthems sounded, supporting a hypothesis proposed by Rihmer. PMID:21526589

  4. Dual rate pressure relief valve

    NASA Technical Reports Server (NTRS)

    Steeneken, J.

    1968-01-01

    Pressure relief valve vents at a slow bleed rate at one pressure level and at a higher bleed rate at a higher pressure level. The value housing contains a sleeve, inlet port, outlet port, an orifice, a ball and seat arrangement, and a belleville spring diaphragm.

  5. What Is a Reaction Rate?

    ERIC Educational Resources Information Center

    Schmitz, Guy

    2005-01-01

    The definition of reaction rate is derived and demonstrations are made for the care to be taken while using the term. Reaction rate can be in terms of a reaction property, the extent of reaction and thus it is possible to give a definition applicable in open and closed systems.

  6. Metabolic rate, heart rate, and tailbeat frequency during sustained swimming in the leopard shark Triakis semifasciata.

    PubMed

    Scharold, J; Lai, N C; Lowell, W R; Graham, J B

    1989-01-01

    Heart rate, metabolic rate, and tailbeat frequency were simultaneously recorded from seven leopard sharks (Triakis semifasciata) during steady swimming at controlled speeds to evaluate the usefulness of heart rate as a measure of field metabolic rate. Heart rate was monitored by acoustic telemetry using a frequency modulated ECG transmitter. Metabolic rate was measured as oxygen consumption in a swimming tunnel respirometer. For instrumented sharks, mean resting oxygen consumption rate and heart rate were 105.3 +/- 35.6 (SE) mg O2.kg-1.h-1 and 36.6 +/- 1.8 (SE) beats.min-1, respectively. While swimming at the maximum sustained speed (0.84 +/- 0.03 lengths.s-1) for 30-60 min, these rates were 229.3 +/- 13.2 mg O2.kg-1.h-1 and 46.9 +/- 0.9 beats.min-1. Although a significant linear regression was obtained between metabolic rate and heart rate, a low overall correlation coefficient may result from the existence of separate individual regressions and confounding changes in stroke volume and/or arteriovenous oxygen difference. Heart rate was approximately as closely correlated with oxygen consumption rate as swimming speed was. A significant linear relationship was obtained between tailbeat frequency and swimming speed to speeds of 0.75 lengths.s-1. PMID:2776865

  7. Innovative Rates Program. Final report

    SciTech Connect

    Not Available

    1982-06-21

    Title II of the Energy Conservation and Production Act (ECPA) as amended by the Public Utility Regulatory Policies Act (PURPA) provided financial assistance to state utility regulatory commissions, nonregulated electric utilities, and the Tennessee Valley Authority through the Innovative Rates Program. The financial assistance was to be used to plan or carry out electric utility regulatory rate reform initiatives relating to innovative rate structures that encourage conservation of energy, electric utility efficiency and reduced costs, and equitable rates to consumers. The Federal and local objectives of the project are described. Activities planned and accomplishments are summarized for the following: project management, data collection, utility bill evaluation, billing enclosure/mailing evaluation, media program evaluation, display evaluation, rate study sessions evaluation, speakers bureau evaluation, and individual customer contacts. A timetable/milestone chart and financial information are included. (MHR)

  8. New fine structure cooling rate

    NASA Technical Reports Server (NTRS)

    Hoegy, W. R.

    1976-01-01

    One of the dominant electron cooling processes in the ionosphere is caused by electron impact induced fine structure transitions among the ground state levels of atomic oxygen. This fine structure cooling rate is based on theoretical cross sections. Recent advances in the numerical cross section determinations to include polarization effects and more accurate representations of the atomic target result in new lower values. These cross sections are employed in this paper to derive a new fine structure cooling rate which is between 40% and 60% of the currently used rate. A new generalized formula is presented for the cooling rate (from which the fine structure cooling rate is derived), valid for arbitrary mass and temperature difference of the colliding particles and arbitrary inelastic energy difference.

  9. The Logic of Collective Rating

    NASA Astrophysics Data System (ADS)

    Nax, Heinrich

    2016-05-01

    The introduction of participatory rating mechanisms on online sales platforms has had substantial impact on firms' sales and profits. In this note, we develop a dynamic model of consumer influences on ratings and of rating influences on consumers, focussing on standard 5-star mechanisms as implemented by many platforms. The key components of our social influence model are the consumer trust in the `wisdom of crowds' during the purchase phase and indirect reciprocity during the rating decision. Our model provides an overarching explanation for well-corroborated empirical regularities. We quantify the performance of the voluntary rating mechanism in terms of realized consumer surplus with the no-mechanism and full-information benchmarks, and identify how it could be improved.

  10. The Average of Rates and the Average Rate.

    ERIC Educational Resources Information Center

    Lindstrom, Peter

    1988-01-01

    Defines arithmetic, harmonic, and weighted harmonic means, and discusses their properties. Describes the application of these properties in problems involving fuel economy estimates and average rates of motion. Gives example problems and solutions. (CW)

  11. [Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

    PubMed

    Zhu, Mingshan; Zeng, Bixin

    2015-03-01

    In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module. PMID:26524782

  12. Comment on 'Time modulation of K-shell electron capture decay rates of H-like heavy ions at GSI experiments.'

    SciTech Connect

    Lipkin, H. J.; Physics; Weizmann Inst. of Science; Tel Aviv Univ.

    2010-04-16

    A Comment on the Letter by A.N. Ivanov and P. Kienle, Physical Review Letters volume 103, Issue 6, 062502 (2009). The authors of the Letter offer a Reply to experimental data at GSI, the rates of the number of daughter ions, produced by the nuclear K shell electron capture decays of the H-like heavy ions with one electron in the K shell, such as {sup 140}Pr{sup 58+}, {sup 142}Pm{sup 60+}, and {sup 122}I{sup 52+}, are modulated in time with periods T{sub EC} of the order of a few seconds, obeying an A scaling T{sub EX}=A/20 s, where A is the mass number of the mother nuclei, and with amplitudes a{sub d {sup EC}}{approx}0.21. We show that these data can be explained in terms of the interference of two massive neutrino mass eigenstates. The appearance of the interference term is due to overlap of massive neutrino mass eigenstate energies and of the wave functions of the daughter ions in two-body decay channels, caused by the energy and momentum uncertainties introduced by time differential detection of the daughter ions in GSI experiments.

  13. The Airline Quality Rating 2001

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D.; Headley, Dean E.

    2001-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, Airline Quality Rating 2001, reflects monthly Airline Quality Rating scores for 2000. AQR scores for the calendar year 2000 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2001 is a summary of month-by-month quality ratings for the ten major U.S. airlines operating during 2000. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of on-time arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, major airlines comparative performance for the calendar year of 2000 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for major airlines domestic operations for the 12 month period of 2000, and industry average results. Also, comparative Airline Quality Rating data for 1999 are included for each airline to provide historical perspective regarding performance quality in the industry.

  14. Deformational injection rate measuring method

    NASA Astrophysics Data System (ADS)

    Marčič, Milan

    2002-09-01

    After completing the diesel engine endurance testing, we detected various traces of thermal load on the walls of combustion chambers located in the engine pistons. The engines were fitted with ω combustion chambers. The thermal load of different intensity levels occurred where the spray of fuel, fuel vapor, and air interacted with the combustion chamber wall. The uneven thermal load distribution of the combustion chamber wall results from varying injection rates in each injection nozzle hole. The most widely applied controlling methods so far for injection rate measurement, such as the Zeuch and Bosch concepts, allow measurement of only the total injection rate in multihole nozzles, without providing any indication whatsoever of the injection rate differences in individual injection nozzle holes. The new deformational measuring method described in the article allows the injection rate to be measured in each hole of the multihole nozzle. The results of the measurements using this method showed that the differences occurred in injection rates of individual injection nozzle holes. These differences may be the cause of various thermal loads on the combustion chamber walls. The criterion for injection rate is the deformation of the membrane due to an increase in the fuel quantity in the measuring space and due to the pressure waves resulting from the fuel being injected into the measuring space. The membrane deformation is measured using strain gauges, glued to the membrane and forming the Wheatstone's bridge. We devoted special attention to the temperature compensation of the Wheatstone's bridge and the membrane, heated up during the measurements.

  15. The Airline Quality Rating 2003

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D.; Headley, Dean E.

    2003-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2003, reflects monthly Airline Quality Rating scores for 2002. AQR scores for the calendar year 2002 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2003 is a summary of month-by-month quality ratings for the 10 largest U.S. airlines operating during 2002. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of ontime arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, airlines comparative performance for the calendar year of 2002 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for domestic airline operations for the 12-month period of 2002, and industry average results. Also, comparative Airline Quality Rating data for 2001 are included for each airline to provide historical perspective regarding performance quality in the industry.

  16. The Airline Quality Rating 2004

    NASA Technical Reports Server (NTRS)

    Fink, Mary M. (Editor); Bowen, Brent D.; Headley, Dean E.

    2004-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2004, reflects monthly Airline Quality Rating scores for 2003. AQR scores for the calendar year 2003 are based on 15 elements in four major areas that focus on airline performance aspects important to air travel consumers. The Airline Quality Rating 2004 is a summary of month-by-month quality ratings for U.S. airlines that have at least 1 % of domestic passenger volume during 2003. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of on-time arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, airlines comparative performance for the calendar year of 2003 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for domestic airline operations for the 12-month period of 2003, and industry results. Also, comparative Airline Quality Rating data for 2002 are included, where available, to provide historical perspective regarding performance quality in the industry.

  17. Growth Rate and Turgor Pressure

    PubMed Central

    Green, Paul B.; Cummins, W. Raymond

    1974-01-01

    Because turgor pressure is regarded as the driving force for cell extension, any general theory of plant growth requires quantitative information on the relationship between steady irreversible growth rate and turgor pressure. To investigate contrasting views of this relation an automated apparatus was constructed which perfused both the outer and inner epidermis of a single coleoptile while its growth rate was continuously recorded. Turgor was altered abruptly by perfusing with solutions of varying tonicity. With specially grown rye coleoptiles the half-time of the osmo-elastic response was reduced to 2 minutes or less. After decay of this response, however, rate continued to change (so as to partially compensate the effects of the turgor shift in question) for 30 to 60 minutes. Only then could a steady rate be taken. A characterization of steady rate versus turgor covering five turgor values for a single coleoptile thus required many hours. The conclusions are as follows. (a) The change in steady rate, per unit change in turgor, was much greater +IAA than −IAA. (b) Both auxin and turgor act to reset an apparent stabilizing system whose presence is shown in the partial compensation of the initial response to turgor shifts. The above “extensibility” changes are operational only. They need not reflect changes in the immediate physical extensibility of the wall; they could reflect changes in a process acting on the wall. (c) The growth rate versus turgor relation shows some hysteresis. PMID:16658991

  18. The Airline Quality Rating 2002

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D.; Headley, Dean E.

    2002-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, Airline Quality Rating 2002, reflects monthly Airline Quality Rating scores for 2001. AQR scores for the calendar year 2001 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2002 is a summary of month-by-month quality ratings for the 11 largest U.S. airlines operating during 2001. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of on-time arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, airlines comparative performance for the calendar year of 2001 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for domestic airline operations for the 12-month period of 2001, and industry average results. Also, comparative Airline Quality Rating data for 2000 are included for each airline to provide historical perspective regarding performance quality in the industry.

  19. The Airline Quality Rating 2004

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D.; Headley, Dean E.

    2004-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2004, reflects monthly Airline Quality Rating scores for 2003. AQR scores far the calendar year 2003 are based on 15 elemnts in four major areas that focus on airline performance aspects important to air travel consumers. The Airline Quality Rating 2004 is a summary of month-by-month quality ratings for U.S. airlines that have at least 1% of domestic passenger volume during 2003. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of on-time arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, airlines comparative performance for the calendar year of 2003 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for domestic airline operations for the 12-month period of 2003, and industry results. Also, comparative Airline Quality Rating data for 2002 are included, where available, to provide historical perspective

  20. The Airline Quality Rating 1999

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D.; Headley, Dean E.

    1999-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline performance on combined multiple criteria. This current report, Airline Quality Rating 1999, reflects an updated approach to calculating monthly Airline Quality Rating scores for 1998. AQR scores for the calendar year 1998 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating is a summary of month-by-month quality ratings for the ten major U.S. airlines operating during 1998. Using the Airline Quality Rating system of weighted averages and monthly performance data in the areas of on-time arrivals, involuntary denied boardings, mishandled baggage, and a combination of 12 customer complaint categories, major airlines comparative performance for the calendar year 1998 is reported. This research monograph contains a brief summary of the AQR methodology, detailed data and charts that track comparative quality for major airlines domestic operations for the 12 month period of 1998, and industry average results. Also, comparative Airline Quality Rating data for 1997, using the updated criteria, are included to provide a reference point regarding quality in the industry.

  1. Stochastic analysis of nucleation rates

    NASA Astrophysics Data System (ADS)

    Johansson, Jonas

    2016-02-01

    We show that approximating the Becker-Döring equations with a Langevin equation results in multiplicative noise, which in turn leads to a family of possible Fokker-Planck equations according to the Ito-Stratonovich dilemma. Using a simple and general model for the attachment and detachment rates, we find that the Ito choice approximates the nucleation rate best and also coincides with the Fokker-Planck equation resulting from the common way to Taylor expand the original set of rate equations.

  2. Renormalized reaction and relaxation rates

    NASA Astrophysics Data System (ADS)

    Gorbachev, Yuriy E.

    2016-06-01

    Impact of the non-equilibrium on the reaction and relaxation rates (called as generalized relaxation rates - GRR), for the spatially inhomogeneous gas mixture is considered. Discarding the assumption that the 'chemical' part of the collisional integral is a small correction to non-reactive part, the expression for the zero-order GRR is derived. They are represented as a renormalization of the traditional reaction and relaxation rates, which means mixing of all corresponding processes. Thus all reactions and relaxation processes are entangled.

  3. Dual-Flow-Rate Valve

    NASA Technical Reports Server (NTRS)

    Allbritain, R. H.

    1986-01-01

    Flow-control device precisely adjusted for two rates. Heart of twoposition valve is sliding poppet. At far-right position, poppet allows low flow. At far-left position, allows high flow. Valve supplies high-pressure gas at either of two preselected flow rates. Valve adjustable between 0.12 and 1.2 lb/s (0.054 and 0.54 kg/s) of hydrogen at 3,300 lb/in.2 (23 MN/m2) and 80 degrees F (27 degrees C). Two flow rates preadjusted between these limits in increments of 0.01 lb/s (0.0045 kg/s).

  4. Stochastic analysis of nucleation rates.

    PubMed

    Johansson, Jonas

    2016-02-01

    We show that approximating the Becker-Döring equations with a Langevin equation results in multiplicative noise, which in turn leads to a family of possible Fokker-Planck equations according to the Ito-Stratonovich dilemma. Using a simple and general model for the attachment and detachment rates, we find that the Ito choice approximates the nucleation rate best and also coincides with the Fokker-Planck equation resulting from the common way to Taylor expand the original set of rate equations. PMID:26986388

  5. 75 FR 80866 - Credit Rating Standardization Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... all credit rating agencies issue credit ratings using identical terms; standardizing the market stress... stress; and standardizing credit rating terminology across asset classes, so that named ratings... market stress conditions under which ratings are evaluated; (C) requiring a quantitative...

  6. Minimizing Variation in Outdoor CPV Power Ratings: Preprint

    SciTech Connect

    Muller, M.; Marion, B.; Rodriguez, J.; Kurtz, S.

    2011-07-01

    The CPV community has agreed to have both indoor and outdoor power ratings at the module level. The indoor rating provides a repeatable measure of module performance as it leaves the factory line while the outdoor rating provides a measure of true performance under real world conditions. The challenge with an outdoor rating is that the spectrum, temperature, wind speed, etc are constantly in flux and therefore the resulting power rating varies from day to day and month to month. This work examines different methodologies for determining the outdoor power rating with the goal of minimizing variation even if data are collected under changing meteorological conditions.

  7. Gearbox gene expression and growth rate.

    PubMed

    Aldea, M; Garrido, T; Tormo, A

    1993-07-01

    Regulation of gene expression in prokaryotic cells usually takes place at the level of transcription initiation. Different forms of RNA polymerase recognizing specific promoters are engaged in the control of many prokaryotic regulons. This also seems to be the case for some Escherichia coli genes that are induced at low growth rates and by nutrient starvation. Their gene products are synthesized at levels inversely proportional to growth rate, and this mode of regulation has been termed gearbox gene expression. This kind of growth-rate modulation is exerted by specific transcriptional initiation signals, the gearbox promoters, and some of them depend on a putative new σ factor (RpoS). Gearbox promoters drive expression of morphogenetic and cell division genes at constant levels per cell and cycle to meet the demands of cell division and septum formation. A mechanism is proposed that could sense the growth rate of the cell to alter gene expression by the action of specific σ factors. PMID:24420108

  8. Idiot Savants: Rate of Incidence

    ERIC Educational Resources Information Center

    Hill, A. Lewis

    1977-01-01

    A survey of 300 public residential facilities for the mentally retarded revealed a .06 percent incidence rate for idiot savants, persons of low intelligence who possess an unusually high skill in some special task. (CL)

  9. Confidence rating for eutrophication assessments.

    PubMed

    Brockmann, Uwe H; Topcu, Dilek H

    2014-05-15

    Confidence of monitoring data is dependent on their variability and representativeness of sampling in space and time. Whereas variability can be assessed as statistical confidence limits, representative sampling is related to equidistant sampling, considering gradients or changing rates at sampling gaps. By the proposed method both aspects are combined, resulting in balanced results for examples of total nitrogen concentrations in the German Bight/North Sea. For assessing sampling representativeness surface areas, vertical profiles and time periods are divided into regular sections for which individually the representativeness is calculated. The sums correspond to the overall representativeness of sampling in the defined area/time period. Effects of not sampled sections are estimated along parallel rows by reducing their confidence, considering their distances to next sampled sections and the interrupted gradients/changing rates. Confidence rating of time sections is based on maximum differences of sampling rates at regular time steps and related means of concentrations. PMID:24680718

  10. Blood Pressure vs. Heart Rate

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More Blood Pressure vs. Heart Rate Updated:Aug 30,2016 Blood ... last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

  11. TRMM Sees Chantal's Rainfall Rates

    NASA Video Gallery

    On July 8, NASA's TRMM satellite saw Tropical Storm Chantal's heaviest rainfall happening at a rate of over 115.5 mm/hr. (~4.5 inches) near Chantal's center where thunderstorms reached heights of o...

  12. Tropical Storm Faxai's Rainfall Rates

    NASA Video Gallery

    This animation shows Tropical Storm Faxai's rainfall rates on March 2 from a TRMM TMI/PR rainfall analysis being faded in over infrared cloud data from the TRMM VIRS instrument. Credit: SSAI/NASA, ...

  13. Low bit rate speech transmission

    NASA Astrophysics Data System (ADS)

    Rothweiler, J.; Bertrand, J.

    The achievement of very low bit rates in all-digital military communications is important in tactical systems. Attention is presently given to a 400-2400 bit/sec system in which feature extraction is performed by standard linear predictive coding together with pattern matching by vector quantization and trellis coding. Some part of this system have been implemented in hardware, and others in simulation. Diagnostic rhyme test results are presented to indicate the performance of the system at various bit rates.

  14. Strain Rates and Scalar Dissipation Rates in Gaseous Transverse Jets

    NASA Astrophysics Data System (ADS)

    Shoji, Takeshi; Gevorkyan, Levon; Besnard, Andrea; Karagozian, Ann

    2015-11-01

    This experimental study quantifies local strain rates and scalar dissipation rates for the non-reactive gaseous jet in crossflow (JICF) using simultaneous acetone planar laser-induced fluorescence (PLIF) imaging and stereo particle image velocimetry (PIV). Flush nozzle and flush pipe injectors are used to create jets consisting of mixtures of He and N2, with varying exit velocity profiles, jet-to-crossflow momentum flux ratios J, and density ratios S. Strain rates in the vicinity of windward and lee-side jet shear layers are quantified based both on scalar dissipation rates extracted from PLIF measurements within locally 1D layer-like structures and on vector fields extracted from PIV measurements. Strain rates from the simultaneous measurements are in very good qualitative agreement with one another on the jets' windward and lee sides, and are also consistent with flame ignition locations in comparable reactive JICF experiments. Quantitative differences in strain fields are most pronounced at lower J values, corresponding to absolutely unstable shear layers and high local strain fields, although these differences are affected by the PLIF spatial resolution for a range of flow conditions. Extraction of dominant mode structures via POD will also be presented. Supported by NSF grant CBET-1437014 & AFOSR grant FA9550-15-1-0261 (A004376801).

  15. Ratings for emotion film clips.

    PubMed

    Gabert-Quillen, Crystal A; Bartolini, Ellen E; Abravanel, Benjamin T; Sanislow, Charles A

    2015-09-01

    Film clips are widely utilized to elicit emotion in a variety of research studies. Normative ratings for scenes selected for these purposes support the idea that selected clips correspond to the intended target emotion, but studies reporting normative ratings are limited. Using an ethnically diverse sample of college undergraduates, selected clips were rated for intensity, discreteness, valence, and arousal. Variables hypothesized to affect the perception of stimuli (i.e., gender, race-ethnicity, and familiarity) were also examined. Our analyses generally indicated that males reacted strongly to positively valenced film clips, whereas females reacted more strongly to negatively valenced film clips. Caucasian participants tended to react more strongly to the film clips, and we found some variation by race-ethnicity across target emotions. Finally, familiarity with the films tended to produce higher ratings for positively valenced film clips, and lower ratings for negatively valenced film clips. These findings provide normative ratings for a useful set of film clips for the study of emotion, and they underscore factors to be considered in research that utilizes scenes from film for emotion elicitation. PMID:24984981

  16. Correlation between gamma index passing rate and clinical dosimetric difference for pre-treatment 2D and 3D volumetric modulated arc therapy dosimetric verification

    PubMed Central

    Jin, X; Yan, H; Han, C; Zhou, Y; Yi, J

    2015-01-01

    Objective: To investigate comparatively the percentage gamma passing rate (%GP) of two-dimensional (2D) and three-dimensional (3D) pre-treatment volumetric modulated arc therapy (VMAT) dosimetric verification and their correlation and sensitivity with percentage dosimetric errors (%DE). Methods: %GP of 2D and 3D pre-treatment VMAT quality assurance (QA) with different acceptance criteria was obtained by ArcCHECK® (Sun Nuclear Corporation, Melbourne, FL) for 20 patients with nasopharyngeal cancer (NPC) and 20 patients with oesophageal cancer. %DE were calculated from planned dose–volume histogram (DVH) and patients' predicted DVH calculated by 3DVH® software (Sun Nuclear Corporation). Correlation and sensitivity between %GP and %DE were investigated using Pearson's correlation coefficient (r) and receiver operating characteristics (ROCs). Results: Relatively higher %DE on some DVH-based metrics were observed for both patients with NPC and oesophageal cancer. Except for 2%/2 mm criterion, the average %GPs for all patients undergoing VMAT were acceptable with average rates of 97.11% ± 1.54% and 97.39% ± 1.37% for 2D and 3D 3%/3 mm criteria, respectively. The number of correlations for 3D was higher than that for 2D (21 vs 8). However, the general correlation was still poor for all the analysed metrics (9 out of 26 for 3D 3%/3 mm criterion). The average area under the curve (AUC) of ROCs was 0.66 ± 0.12 and 0.71 ± 0.21 for 2D and 3D evaluations, respectively. Conclusions: There is a lack of correlation between %GP and %DE for both 2D and 3D pre-treatment VMAT dosimetric evaluation. DVH-based dose metrics evaluation obtained from 3DVH will provide more useful analysis. Advances in knowledge: Correlation and sensitivity of %GP with %DE for VMAT QA were studied for the first time. PMID:25494412

  17. Civilian residential fire fatality rates: Six high-rate states versus six low-rate states

    NASA Astrophysics Data System (ADS)

    Hall, J. R., Jr.; Helzer, S. G.

    1983-08-01

    Results of an analysis of 1,600 fire fatalities occurring in six states with high fire-death rates and six states with low fire-death rates are presented. Reasons for the differences in rates are explored, with special attention to victim age, sex, race, and condition at time of ignition. Fire cause patterns are touched on only lightly but are addressed more extensively in the companion piece to this report, "Rural and Non-Rural Civilian Residential Fire Fatalities in Twelve States', NBSIR 82-2519.

  18. A dosimetric analysis of intensity-modulated radiation therapy (IMRT) as an alternative to adjuvant high-dose-rate (HDR) brachytherapy in early endometrial cancer patients

    SciTech Connect

    Aydogan, Bulent . E-mail: baydogan@radonc.uchicago.edu; Mundt, Arno J.; Smith, Brett D.; Mell, Loren K.; Wang, Steve; Sutton, Harold; Roeske, John C.

    2006-05-01

    Purpose: To evaluate the role of intensity-modulated radiation treatment (IMRT) as an alternative to high-dose-rate (HDR) brachytherapy in the treatment of the vagina in postoperative early endometrial cancer patients after surgery. Methods and Materials: Planning computed tomography (CT) scans of 10 patients previously treated with HDR were used in this study. In all cases, a dose of 700 cGy/fraction was prescribed at a distance of 0.5 cm from the cylinder surface. The same CT scans were then used in IMRT planning. In this paradigm, the vaginal cylinder represents a component of a hypothetical immobilization system that would be indexed to the linac treatment table. Results: Our study showed that IMRT provided relatively lower rectal doses than HDR when treatment was prescribed at a distance of 0.5 cm away from the cylinder surface. Maximum rectal doses were lower with IMRT compared with HDR (average: 89.0% vs. 142.6%, respectively, p < 0.05). Moreover, the mean rectal dose was lower in IMRT plans compared with HDR plans with treatment prescribed either to the surface (average: 14.8% vs. 21.4%, respectively, p < 0.05) or to 0.5 cm (average: 19.6% vs. 33.5%, respectively, p < 0.05). IMRT plans had planning target volume (PTV) coverage comparable with HDR (average PTV minimum for treatment prescribed to 0.5 cm: 93.9% vs. 92.1%, p = 0.71, respectively) with less inhomogeneity (average PTV maximum: 110.8% vs. 381.6%, p < 0.05). Conclusion: Our dosimetric analysis suggests that when used in conjunction with a suitable immobilization system, IMRT may provide an alternative to HDR brachytherapy in women with early endometrial cancer after hysterectomy. However, more studies are needed to evaluate the clinical merit of the IMRT in these patients.

  19. Matching and Conditioned Reinforcement Rate

    PubMed Central

    Shahan, Timothy A; Podlesnik, Christopher A; Jimenez-Gomez, Corina

    2006-01-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative conditioned reinforcement rate. In the absence of observing responses, unsignaled periods of food delivery on a variable-interval 90-s schedule alternated with extinction on a center key (i.e., a mixed schedule was in effect). Two concurrently available observing responses produced 15-s access to a stimulus differentially associated with the schedule of food delivery (S+). The relative rate of S+ deliveries arranged by independent variable-interval schedules for the two observing responses varied across conditions. The relation between the ratio of observing responses and the ratio of S+ deliveries was well described by the generalized matching law, despite the absence of changes in the rate of food delivery. In addition, the value of the S+ deliveries likely remained constant across conditions because the ratio of S+ to mixed schedule food deliveries remained constant. Assuming that S+ deliveries serve as conditioned reinforcers, these findings are consistent with the functional similarity between primary and conditioned reinforcers suggested by general choice theories based on the concatenated matching law (e.g., contextual choice and hyperbolic value-added models). These findings are inconsistent with delay reduction theory, which has no terms for the effects of rate of conditioned reinforcement in the absence of changes in rate of primary reinforcement. PMID:16673824

  20. 76 FR 59767 - Interest Rates; Notice

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... publishes an interest rate called the optional ``peg'' rate (13 CFR 120.214) on a quarterly basis. This rate... direct loan. This rate may be used as a base rate for guaranteed fluctuating interest rate SBA loans. This rate will be 3.125 (3\\1/8\\) percent for the October-December quarter of FY 2012. Pursuant to...

  1. Implementation of Constant Dose Rate and Constant Angular Spacing Intensity-modulated Arc Therapy for Cervical Cancer by Using a Conventional Linear Accelerator

    PubMed Central

    Zhang, Ruo-Hui; Fan, Xiao-Mei; Bai, Wen-Wen; Cao, Yan-Kun

    2016-01-01

    Background: Volumetric-modulated arc therapy (VMAT) can only be implemented on the new generation linacs such as the Varian Trilogy® and Elekta Synergy®. This prevents most existing linacs from delivering VMAT. The purpose of this study was to investigate the feasibility of using a conventional linear accelerator delivering constant dose rate and constant angular spacing intensity-modulated arc therapy (CDR-CAS-IMAT) for treating cervical cancer. Methods: Twenty patients with cervical cancer previously treated with intensity-modulated radiation therapy (IMRT) using Varian Clinical 23EX were retreated using CDR-CAS-IMAT. The planning target volume (PTV) was set as 50.4 Gy in 28 fractions. Plans were evaluated based on the ability to meet the dose volume histogram. The homogeneity index (HI), target volume conformity index (CI), the dose to organs at risk, radiation delivery time, and monitor units (MUs) were also compared. The paired t-test was used to analyze the two data sets. All statistical analyses were performed using SPSS 19.0 software. Results: Compared to the IMRT group, the CDR-CAS-IMAT group showed better PTV CI (0.85 ± 0.03 vs. 0.81 ± 0.03, P = 0.001), clinical target volume CI (0.46 ± 0.05 vs. 0.43 ± 0.05, P = 0.001), HI (0.09±0.02 vs. 0.11 ± 0.02, P = 0.005) and D95 (5196.33 ± 28.24 cGy vs. 5162.63 ± 31.12 cGy, P = 0.000), and cord D2 (3743.8 ± 118.7 cGy vs. 3806.2 ± 98.7 cGy, P = 0.017) and rectum V40 (41.9 ± 6.1% vs. 44.2 ± 4.8%, P = 0.026). Treatment time (422.7 ± 46.7 s vs. 84.6 ± 7.8 s, P = 0.000) and the total plan Mus (927.4 ± 79.1 vs. 787.5 ± 78.5, P = 0.000) decreased by a factor of 0.8 and 0.15, respectively. The IMRT group plans were superior to the CDR-CAS-IMAT group plans considering decreasing bladder V50 (17.4 ± 4.5% vs. 16.6 ± 4.2%, P = 0.049), bowel V30 (39.6 ± 6.5% vs. 36.6 ± 7.5%, P = 0.008), and low-dose irradiation volume; there were no significant differences in other statistical indexes. Conclusions

  2. HEART RATE VARIABILITY AND 24-HOUR MINIMUM HEART RATE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heart rate variability (HRV) indices based on 24-hour electrocardiograph recordings have been used in clinical research studies to assess the aggregate activity of the autonomic nervous system. While 24-hour HRV is generally considered non-invasive, use in research protocols typically involves cons...

  3. LINEAR COUNT-RATE METER

    DOEpatents

    Henry, J.J.

    1961-09-01

    A linear count-rate meter is designed to provide a highly linear output while receiving counting rates from one cycle per second to 100,000 cycles per second. Input pulses enter a linear discriminator and then are fed to a trigger circuit which produces positive pulses of uniform width and amplitude. The trigger circuit is connected to a one-shot multivibrator. The multivibrator output pulses have a selected width. Feedback means are provided for preventing transistor saturation in the multivibrator which improves the rise and decay times of the output pulses. The multivibrator is connected to a diode-switched, constant current metering circuit. A selected constant current is switched to an averaging circuit for each pulse received, and for a time determined by the received pulse width. The average output meter current is proportional to the product of the counting rate, the constant current, and the multivibrator output pulse width.

  4. Dual physiological rate measurement instrument

    NASA Technical Reports Server (NTRS)

    Cooper, Tommy G. (Inventor)

    1990-01-01

    The object of the invention is to provide an instrument for converting a physiological pulse rate into a corresponding linear output voltage. The instrument which accurately measures the rate of an unknown rectangular pulse wave over an extended range of values comprises a phase-locked loop including a phase comparator, a filtering network, and a voltage-controlled oscillator, arranged in cascade. The phase comparator has a first input responsive to the pulse wave and a second input responsive to the output signal of the voltage-controlled oscillator. The comparator provides a signal dependent on the difference in phase and frequency between the signals appearing on the first and second inputs. A high-input impedance amplifier accepts an output from the filtering network and provides an amplified output DC signal to a utilization device for providing a measurement of the rate of the pulse wave.

  5. Coal Transportation Rate Sensitivity Analysis

    EIA Publications

    2005-01-01

    On December 21, 2004, the Surface Transportation Board (STB) requested that the Energy Information Administration (EIA) analyze the impact of changes in coal transportation rates on projected levels of electric power sector energy use and emissions. Specifically, the STB requested an analysis of changes in national and regional coal consumption and emissions resulting from adjustments in railroad transportation rates for Wyoming's Powder River Basin (PRB) coal using the National Energy Modeling System (NEMS). However, because NEMS operates at a relatively aggregate regional level and does not represent the costs of transporting coal over specific rail lines, this analysis reports on the impacts of interregional changes in transportation rates from those used in the Annual Energy Outlook 2005 (AEO2005) reference case.

  6. Recent deformation rates on Venus

    NASA Astrophysics Data System (ADS)

    Grimm, Robert E.

    1994-11-01

    Constraints on the recent geological evolution of Venus may be provided by quantitative estimates of the rates of the principal resurfacing processes, volcanism and tectonism. This paper focuses on the latter, using impact craters as strain indicators. The total postimpact tectonic strain lies in the range 0.5-6.5%, which defines a recent mean strain rate of 10-18-10-17/s when divided by the mean surface age. Interpretation of the cratering record as one of pure production requires a decline in resurfacing rates at about 500 Ma (catastrophic resurfacing model). If distributed tectonic resurfacing contributed strongly before that time, as suggested by the widespread occurrence of tessera as inliers, the mean global strain rate must have been at least approximately 10-15/s, which is also typical of terrestrial active margins. Numerical calculations of the response of the lithosphere to inferred mantle convective forces were performed to test the hypothesis that a decrease in surface strain rate by at least two orders of magnitude could be caused by a steady decline in heat flow over the last billion years. Parameterized convection models predict that the mean global thermal gradient decreases by only about 5 K/km over this time; even with the exponential dependence of viscosity upon temperature, the surface strain rate drops by little more than one order of magnitude. Strongly unsteady cooling and very low thermal gradients today are necessary to satisfy the catastrophic model. An alternative, uniformitarian resurfacing hypothesis holds that Venus is resurfaced in quasi-random 'patches' several hundred kilometers in size that occur in response to changing mantle convection patterns.

  7. High Data Rate Instrument Study

    NASA Technical Reports Server (NTRS)

    Schober, Wayne; Lansing, Faiza; Wilson, Keith; Webb, Evan

    1999-01-01

    The High Data Rate Instrument Study was a joint effort between the Jet Propulsion Laboratory (JPL) and the Goddard Space Flight Center (GSFC). The objectives were to assess the characteristics of future high data rate Earth observing science instruments and then to assess the feasibility of developing data processing systems and communications systems required to meet those data rates. Instruments and technology were assessed for technology readiness dates of 2000, 2003, and 2006. The highest data rate instruments are hyperspectral and synthetic aperture radar instruments which are capable of generating 3.2 Gigabits per second (Gbps) and 1.3 Gbps, respectively, with a technology readiness date of 2003. These instruments would require storage of 16.2 Terebits (Tb) of information (RF communications case of two orbits of data) or 40.5 Tb of information (optical communications case of five orbits of data) with a technology readiness date of 2003. Onboard storage capability in 2003 is estimated at 4 Tb; therefore, all the data created cannot be stored without processing or compression. Of the 4 Tb of stored data, RF communications can only send about one third of the data to the ground, while optical communications is estimated at 6.4 Tb across all three technology readiness dates of 2000, 2003, and 2006 which were used in the study. The study includes analysis of the onboard processing and communications technologies at these three dates and potential systems to meet the high data rate requirements. In the 2003 case, 7.8% of the data can be stored and downlinked by RF communications while 10% of the data can be stored and downlinked with optical communications. The study conclusion is that only 1 to 10% of the data generated by high data rate instruments will be sent to the ground from now through 2006 unless revolutionary changes in spacecraft design and operations such as intelligent data extraction are developed.

  8. Rate Change Big Bang Theory

    NASA Astrophysics Data System (ADS)

    Strickland, Ken

    2013-04-01

    The Rate Change Big Bang Theory redefines the birth of the universe with a dramatic shift in energy direction and a new vision of the first moments. With rate change graph technology (RCGT) we can look back 13.7 billion years and experience every step of the big bang through geometrical intersection technology. The analysis of the Big Bang includes a visualization of the first objects, their properties, the astounding event that created space and time as well as a solution to the mystery of anti-matter.

  9. Fermentation Rates of Grape Juice

    PubMed Central

    Ough, C. S.; Kunkee, R. E.

    1968-01-01

    Microbiological analysis showed that juices from white grapes had less biotin than juices from red grapes. The biotin content of the juices of some varieties was significantly different from that of other varieties. We did not note any regional effects on the biotin content of the juices. Biotin content of the Cabernet Sauvignon grapes increased significantly with maturity, whereas the biotin content of a white variety did not. The biotin content, with the total nitrogen, can be used to estimate indirectly the yeast growth potential and hence to predict the fermentation rate of the juice. About 84% of the rate variation can be accounted for by the calculated regression equations. PMID:16349801

  10. Neural network for photoplethysmographic respiratory rate monitoring

    NASA Astrophysics Data System (ADS)

    Johansson, Anders

    2001-10-01

    The photoplethysmographic signal (PPG) includes respiratory components seen as frequency modulation of the heart rate (respiratory sinus arrhythmia, RSA), amplitude modulation of the cardiac pulse, and respiratory induced intensity variations (RIIV) in the PPG baseline. The aim of this study was to evaluate the accuracy of these components in determining respiratory rate, and to combine the components in a neural network for improved accuracy. The primary goal is to design a PPG ventilation monitoring system. PPG signals were recorded from 15 healthy subjects. From these signals, the systolic waveform, diastolic waveform, respiratory sinus arrhythmia, pulse amplitude and RIIV were extracted. By using simple algorithms, the rates of false positive and false negative detection of breaths were calculated for each of the five components in a separate analysis. Furthermore, a simple neural network (NN) was tried out in a combined pattern recognition approach. In the separate analysis, the error rates (sum of false positives and false negatives) ranged from 9.7% (pulse amplitude) to 14.5% (systolic waveform). The corresponding value of the NN analysis was 9.5-9.6%.

  11. Online Course Evaluations Response Rates

    ERIC Educational Resources Information Center

    Guder, Faruk; Malliaris, Mary

    2013-01-01

    This paper studies the reasons for low response rates in online evaluations. Survey data are collected from the students to understand factors that might affect student participation in the course evaluation process. When course evaluations were opened to the student body, an email announcement was sent to all students, and a reminder email was…

  12. Dual Brushless Resolver Rate Sensor

    NASA Technical Reports Server (NTRS)

    Howard, David E. (Inventor)

    1996-01-01

    This invention relates to dual analog angular rate sensors which are implemented without the use of mechanical brushes. A resolver rate sensor which includes two brushless resolvers which are mechanically coupled to the same output shaft is provided with inputs which are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. Novelty and advantages of the invention reside in the excitation of a resolver with a DC signal and in the utilization of two resolvers and the trigonometric identity of cos(exp 2)(theta) + sin(exp 2)(theta) = 1 to provide an accurate rate sensor which is sensitive to direction and accurate through zero rate.

  13. Cohort Default Rates in Context

    ERIC Educational Resources Information Center

    Looney, Shannon M.

    2011-01-01

    Burgeoning student loan debt indicates problems not only for the country's borrowers but also for the postsecondary system. The rise in student loan defaults signifies a rise in institutional cohort default rates (CDRs)--a measure of accountability that informs the government and the general public how well an institution prepares its students for…

  14. Metabolic rate meter and method

    NASA Technical Reports Server (NTRS)

    Taylor, T. I.; Ruderman, I. W. (Inventor)

    1968-01-01

    A method is described for measuring the dynamic metabolic rate of a human or animal. The ratio of the exhaled carbon dioxide to a known amount of C(13)02 introduced into the exhalation is determined by mass spectrometry. This provides an instantaneous measurement of the carbon dioxide generated.

  15. 78 FR 15973 - Fee Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Indian Gaming Commission Fee Rate Correction In notice document 2013-05334, appearing on page 14821 in the issue of Thursday, March 7, 2013, make the following correction: On page 14821, in...

  16. On Comparing Transition Rate Gains.

    ERIC Educational Resources Information Center

    Reuterberg, Sven-Eric

    This report is about the problem of making transition or enrollment rate gains comparable. It is shown that measures based on the proportions themselves, i.e. the difference between proportions, the proportion ratio and the residual gain ratio do not make the gains comparable. Instead a non-linear transformation has to be done. Two such…

  17. Exchange Rates and Old People.

    ERIC Educational Resources Information Center

    Dowd, James J.

    1980-01-01

    Extends earlier work on aging as a process of exchange by focusing on the issue of exchange rates and how they are negotiated. Access to power resources declines with age, placing the old person in the position of negotiating from weakness. (Author)

  18. Variable gas leak rate valve

    DOEpatents

    Eernisse, Errol P.; Peterson, Gary D.

    1976-01-01

    A variable gas leak rate valve which utilizes a poled piezoelectric element to control opening and closing of the valve. The gas flow may be around a cylindrical rod with a tubular piezoelectric member encircling the rod for seating thereagainst to block passage of gas and for reopening thereof upon application of suitable electrical fields.

  19. Divergent Thinking and Interview Ratings

    ERIC Educational Resources Information Center

    Batey, Mark; Rawles, Richard; Furnham, Adrian

    2009-01-01

    This study examined divergent thinking (DT) test scores of applicants taking part in a selection procedure for an undergraduate psychology degree (N = 370). Interviewers made six specific (creative intelligence, motivation, work habits, emotional stability, sociability, and social responsibility) and one overall recommendation rating on each…

  20. Heating rates in tropical anvils

    NASA Technical Reports Server (NTRS)

    Ackerman, Thomas P.; Valero, Francisco P. J.; Pfister, Leonhard; Liou, Kuo-Nan

    1988-01-01

    The interaction of infrared and solar radiation with tropical cirrus anvils is addressed. Optical properties of the anvils are inferred from satellite observations and from high-altitude aircraft measurements. An infrared multiple-scattering model is used to compute heating rates in tropical anvils. Layer-average heating rates in 2 km thick anvils were found to be on the order of 20 to 30 K/day. The difference between heating rates at cloud bottom and cloud top ranges from 30 to 200 K/day, leading to convective instability in the anvil. The calculations are most sensitive to the assumed ice water content, but also are affected by the vertical distribution of ice water content and by the anvil thickness. Solar heating in anvils is shown to be less important than infrared heating but not negligible. The dynamical implications of the computed heating rates are also explored and it is concluded that the heating may have important consequences for upward mass transport in the tropics. The potential impact of tropical cirrus on the tropical energy balance and cloud forcing are discussed.

  1. Fast repetition rate (FRR) flasher

    DOEpatents

    Kolber, Z.; Falkowski, P.

    1997-02-11

    A fast repetition rate (FRR) flasher is described suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between successive discharges of the discharge capacitor. Advantageously, the control means is operable to discharge the discharge capacitor at a rate greater than 10,000 Hz and even up to a rate greater than about 250,000 Hz. 14 figs.

  2. PBXN-110 Burn Rate Estimate

    SciTech Connect

    Glascoe, E

    2008-08-11

    It is estimated that PBXN-110 will burn laminarly with a burn function of B = (0.6-1.3)*P{sup 1.0} (B is the burn rate in mm/s and P is pressure in MPa). This paper provides a brief discussion of how this burn behavior was estimated.

  3. Vehicle crashworthiness ratings in Australia.

    PubMed

    Cameron, M; Mach, T; Neiger, D; Graham, A; Ramsay, R; Pappas, M; Haley, J

    1994-08-01

    The paper reviews the published vehicle safety ratings based on mass crash data from the United States, Sweden, and Great Britain. It then describes the development of vehicle crashworthiness ratings based on injury compensation claims and police accident reports from Victoria and New South Wales, the two most populous states in Australia. Crashworthiness was measured by a combination of injury severity (of injured drivers) and injury risk (of drivers involved in crashes). Injury severity was based on 22,600 drivers injured in crashes in the two states. Injury risk was based on 70,900 drivers in New South Wales involved in crashes after which a vehicle was towed away. Injury risk measured in this way was compared with the "relative injury risk" of particular model cars involved in two car crashes in Victoria (where essentially only casualty crashes are reported), which was based on the method developed by Folksam Insurance in Sweden from Evans' double-pair comparison method. The results include crashworthiness ratings for the makes and models crashing in Australia in sufficient numbers to measure their crash performance adequately. The ratings were normalised for the driver sex and speed limit at the crash location, the two factors found to be strongly related to injury risk and/or severity and to vary substantially across makes and models of Australian crash-involved cars. This allows differences in crashworthiness of individual models to be seen, uncontaminated by major crash exposure differences. PMID:7916859

  4. Fast repetition rate (FRR) flasher

    DOEpatents

    Kolber, Zbigniew; Falkowski, Paul

    1997-02-11

    A fast repetition rate (FRR) flasher suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between Successive discharges of the discharge capacitor. Advantageously, the control means is operable to discharge the discharge capacitor at a rate greater than 10,000 Hz and even up to a rate greater than about 250,000 Hz.

  5. The Adaptive Behavior Rating Scale.

    ERIC Educational Resources Information Center

    Meyer, William J.

    A scale to identify important behaviors in preschool children was developed, and ratings were related to more traditional indices of development and academic readiness. Teacher interviews were used to identify 62 specific behaviors related to maximally adapted and maximally maladapted kindergarten children. These were incorporated into a…

  6. Columbus Payloads Flow Rate Anomalies

    NASA Technical Reports Server (NTRS)

    Quaranta, Albino; Bufano, Gaetana; DePalo, Savino; Holt, James M.; Szigetvari, Zoltan; Palumberi, Sergio; Hinderer, S.

    2011-01-01

    The Columbus Active Thermal Control System (ATCS) is the main thermal bus for the pressurized racks working inside the European laboratory. One of the ATCS goals is to provide proper water flow rate to each payload (P/L) by controlling actively the pressure drop across the common plenum distribution piping. Overall flow measurement performed by the Water Pump Assembly (WPA) is the only flow rate monitor available at system level and is not part of the feedback control system. At rack activation the flow rate provided by the system is derived on ground by computing the WPA flow increase. With this approach, several anomalies were raised during these 3 years on-orbit, with the indication of low flow rate conditions on the European racks FSL, BioLab, EDR and EPM. This paper reviews the system and P/Ls calibration approach, the anomalies occurred, the engineering evaluation on the measurement approach and the accuracy improvements proposed, the on-orbit test under evaluation with NASA and finally discusses possible short and long term solutions in case of anomaly confirmation.

  7. Frame Rate and Human Vision

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    2012-01-01

    To enhance the quality of the theatre experience, the film industry is interested in achieving higher frame rates for capture and display. In this talk I will describe the basic spatio-temporal sensitivities of human vision, and how they respond to the time sequence of static images that is fundamental to cinematic presentation.

  8. NASA Human-Rating Requirements

    NASA Technical Reports Server (NTRS)

    Groen, Frank; Harkins, Wil; Stamatelatos, Michael

    2010-01-01

    NASA's Procedural Requirements 87052B defines the Human-Rating Certification process and related technical requirements for human spaceflight programs developed by and for NASA. The document specifies Agency-level responsibilities related to the certification, processes to be established by the program, and technical requirements.

  9. Antipredator defenses predict diversification rates

    PubMed Central

    Arbuckle, Kevin; Speed, Michael P.

    2015-01-01

    The “escape-and-radiate” hypothesis predicts that antipredator defenses facilitate adaptive radiations by enabling escape from constraints of predation, diversified habitat use, and subsequently speciation. Animals have evolved diverse strategies to reduce the direct costs of predation, including cryptic coloration and behavior, chemical defenses, mimicry, and advertisement of unprofitability (conspicuous warning coloration). Whereas the survival consequences of these alternative defenses for individuals are well-studied, little attention has been given to the macroevolutionary consequences of alternative forms of defense. Here we show, using amphibians as the first, to our knowledge, large-scale empirical test in animals, that there are important macroevolutionary consequences of alternative defenses. However, the escape-and-radiate hypothesis does not adequately describe them, due to its exclusive focus on speciation. We examined how rates of speciation and extinction vary across defensive traits throughout amphibians. Lineages that use chemical defenses show higher rates of speciation as predicted by escape-and-radiate but also show higher rates of extinction compared with those without chemical defense. The effect of chemical defense is a net reduction in diversification compared with lineages without chemical defense. In contrast, acquisition of conspicuous coloration (often used as warning signals or in mimicry) is associated with heightened speciation rates but unchanged extinction rates. We conclude that predictions based on the escape-and-radiate hypothesis must incorporate the effect of traits on both speciation and extinction, which is rarely considered in such studies. Our results also suggest that knowledge of defensive traits could have a bearing on the predictability of extinction, perhaps especially important in globally threatened taxa such as amphibians. PMID:26483488

  10. Sensor for Injection Rate Measurements

    PubMed Central

    Marcic, Milan

    2006-01-01

    A vast majority of the medium and high speed Diesel engines are equipped with multi-hole injection nozzles nowadays. Inaccuracies in workmanship and changing hydraulic conditions in the nozzles result in differences in injection rates between individual injection nozzle holes. The new deformational measuring method described in the paper allows injection rate measurement in each injection nozzle hole. The differences in injection rates lead to uneven thermal loads of Diesel engine combustion chambers. All today known measuring method, such as Bosch and Zeuch give accurate results of the injection rate in diesel single-hole nozzles. With multihole nozzles they tell us nothing about possible differences in injection rates between individual holes of the nozzle. At deformational measuring method, the criterion of the injected fuel is expressed by the deformation of membrane occurring due to the collision of the pressure wave against the membrane. The pressure wave is generated by the injection of the fuel into the measuring space. For each hole of the nozzle the measuring device must have a measuring space of its own into which fuel is injected as well as its measuring membrane and its own fuel outlet. During measurements procedure the measuring space must be filled with fuel to maintain an overpressure of 5 kPa. Fuel escaping from the measuring device is conducted into the graduated cylinders for measuring the volumetric flow through each hole of the nozzle.The membrane deformation is assessed by strain gauges. They are glued to the membrane and forming the full Wheatstone's bridge. We devoted special attention to the membrane shape and temperature compensation of the strain gauges.

  11. Antipredator defenses predict diversification rates.

    PubMed

    Arbuckle, Kevin; Speed, Michael P

    2015-11-01

    The "escape-and-radiate" hypothesis predicts that antipredator defenses facilitate adaptive radiations by enabling escape from constraints of predation, diversified habitat use, and subsequently speciation. Animals have evolved diverse strategies to reduce the direct costs of predation, including cryptic coloration and behavior, chemical defenses, mimicry, and advertisement of unprofitability (conspicuous warning coloration). Whereas the survival consequences of these alternative defenses for individuals are well-studied, little attention has been given to the macroevolutionary consequences of alternative forms of defense. Here we show, using amphibians as the first, to our knowledge, large-scale empirical test in animals, that there are important macroevolutionary consequences of alternative defenses. However, the escape-and-radiate hypothesis does not adequately describe them, due to its exclusive focus on speciation. We examined how rates of speciation and extinction vary across defensive traits throughout amphibians. Lineages that use chemical defenses show higher rates of speciation as predicted by escape-and-radiate but also show higher rates of extinction compared with those without chemical defense. The effect of chemical defense is a net reduction in diversification compared with lineages without chemical defense. In contrast, acquisition of conspicuous coloration (often used as warning signals or in mimicry) is associated with heightened speciation rates but unchanged extinction rates. We conclude that predictions based on the escape-and-radiate hypothesis must incorporate the effect of traits on both speciation and extinction, which is rarely considered in such studies. Our results also suggest that knowledge of defensive traits could have a bearing on the predictability of extinction, perhaps especially important in globally threatened taxa such as amphibians. PMID:26483488

  12. SU-E-J-116: Uncertainties Associated with Dose Summation of High-Dose Rate Brachytherapy and Intensity Modulated Radiotherapy for Gynecological Cases

    SciTech Connect

    Kauweloa, K; Bergamo, A; Gutierrez, A; Stathakis, S; Papanikolaou, N; Kirby, N; Mavroidis, P

    2015-06-15

    Purpose: Determining the cumulative dose distribution (CDD) for gynecological patients treated with both high-dose rate (HDR) brachytherapy and intensity-modulated radiotherapy (IMRT) is challenging. The purpose of this work is to study the uncertainty of performing this with a structure-guided deformable (SGD) approach in Velocity. Methods: For SGD, the Hounsfield units inside specified contours are overridden to set uniform values. Deformable image registration (DIR) is the run on these process images, which forces the DIR to focus on these contour boundaries. 18 gynecological cancer patients were used in this study. The original bladder and rectum planning contours for these patients were used to drive the SGD. A second set of contours were made of the bladder by the same person with the intent of carefully making them completely consistent with each other. This second set was utilized to evaluate the spatial accuracy of the SGD. The determined spatial accuracy was then multiplied by the local dose gradient to determine a dose uncertainty associated with the SGD dose warping. The normal tissue complication probability (NTCP) was then calculated for each dose volume histogram (DVH) that included four different probabilistic uncertainties associated with the spatial errors (e.g., 68.3% and 95.4%). Results: The NTCPs for each DVH (e.g., NTCP-−95.4%, NTCP-−68.3%, NTCP-68.3%, NTCP-95.4%) differed amongst patients. All patients had an NTCP-−95.4% close to 0%, while NTCP-95.4% ranged from 0.67% to 100%. Nine patients had an NTCP-−95.4% less than 50% while the remaining nine patients had NTCP-95.4% greater than 50%. Conclusion: The uncertainty associated with this CDD technique renders a large NTCP uncertainty. Thus, it is currently not practical for clinical use. The two ways to improve this would be to use more precise contours to drive the SGD and to use a more accurate DIR algorithm.

  13. 13 CFR 301.4 - Investment rates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Investment rates. 301.4 Section... ELIGIBILITY, INVESTMENT RATE AND APPLICATION REQUIREMENTS Investment Rates and Matching Share Requirements § 301.4 Investment rates. (a) Minimum Investment Rate. There is no minimum Investment Rate for a...

  14. 13 CFR 301.4 - Investment rates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Investment rates. 301.4 Section... ELIGIBILITY, INVESTMENT RATE AND APPLICATION REQUIREMENTS Investment Rates and Matching Share Requirements § 301.4 Investment rates. (a) Minimum Investment Rate. There is no minimum Investment Rate for a...

  15. 13 CFR 301.4 - Investment rates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Investment rates. 301.4 Section... ELIGIBILITY, INVESTMENT RATE AND APPLICATION REQUIREMENTS Investment Rates and Matching Share Requirements § 301.4 Investment rates. (a) Minimum Investment Rate. There is no minimum Investment Rate for a...

  16. 13 CFR 301.4 - Investment rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Investment rates. 301.4 Section... ELIGIBILITY, INVESTMENT RATE AND APPLICATION REQUIREMENTS Investment Rates and Matching Share Requirements § 301.4 Investment rates. (a) Minimum Investment Rate. There is no minimum Investment Rate for a...

  17. Heart Rate Sensor for Freshwater Mussels

    NASA Astrophysics Data System (ADS)

    Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.

    2014-12-01

    Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.

  18. Nucleation rate in monotectic alloys

    NASA Astrophysics Data System (ADS)

    Falk, F.

    Cooling a melt of a monotectic system into the miscibility gap results in nucleation of fluid droplets in a fluid matrix prior to solidification. For homogeneous nucleation the temperature dependence of the nucleation rate is calculated. As material parameters the chemical potential of the species involved, the diffusion constant of the fluid, and the surface tension between adjacent phases are important. Since their temperature dependence is not well known from experiments, different theoretical models are used and their influence is discussed. The surface tension turns out to be the most crucial parameter in determining the nucleation rate. For AlIn numerical results are presented. In this system the undercooling with respect to homogeneous nucleation increases from zero at the critical point to 100 K at a composition near the monotectic point.

  19. Improving the RPC rate capability

    NASA Astrophysics Data System (ADS)

    Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Stante, L.; Iuppa, R.; Liberti, B.; Paolozzi, L.; Pastori, E.; Santonico, R.; Toppi, M.

    2016-07-01

    This paper has the purpose to study the rate capability of the Resistive Plate Chamber, RPC, starting from the basic physics of this detector. The effect of different working parameters determining the rate capability is analysed in detail, in order to optimize a new family of RPCs for applications to heavy irradiation environments and in particular to the LHC phase 2. A special emphasis is given to the improvement achievable by minimizing the avalanche charge delivered in the gas. The paper shows experimental results of Cosmic Ray tests, performed to study the avalanche features for different gas gap sizes, with particular attention to the overall delivered charge. For this purpose, the paper studies, in parallel to the prompt electronic signal, also the ionic signal which gives the main contribution to the delivered charge. Whenever possible the test results are interpreted on the basis of the RPC detector physics and are intended to extend and reinforce our physical understanding of this detector.

  20. The instantaneous frequency rate spectrogram

    NASA Astrophysics Data System (ADS)

    Czarnecki, Krzysztof

    2016-01-01

    An accelerogram of the instantaneous phase of signal components referred to as an instantaneous frequency rate spectrogram (IFRS) is presented as a joint time-frequency distribution. The distribution is directly obtained by processing the short-time Fourier transform (STFT) locally. A novel approach to amplitude demodulation based upon the reassignment method is introduced as a useful by-product. Additionally, an estimator of energy density versus the instantaneous frequency rate (IFR) is proposed and referred to as the IFR profile. The energy density is estimated based upon both the classical energy spectrogram and the IFRS smoothened by the median filter. Moreover, the impact of an analyzing window width, additive white Gaussian noise and observation time is tested. Finally, the introduced method is used for the analysis of the acoustic emission of an automotive engine. The recording of the engine of a Lamborghini Gallardo is analyzed as an example.

  1. Child Mortality Rate in Ethiopia

    PubMed Central

    Susuman, A Sathiya

    2012-01-01

    Ethiopia’s childhood mortality has continued to decline although at a swift pace. The drop in urban childhood mortality decline, duration of breastfeeding is the principle reason for the overall decline in mortality trends in Ethiopia. Data from the Ethiopian Demographic and Health Surveys 2000 and 2005 were used. Indirect estimation of Brass and Trussell’s methods were adopted. Selected demographic and socio-economic variables were included in the analysis with statistically significant effects. Findings clearly show neonatal and post neonatal mortality decline gradually. Even though, Ethiopia’s childhood mortality rates are still high. The result shows less than 2 years birth interval have higher infant mortality rates than higher birth interval (113 deaths per 1000). The proper spacing of births allows more time for childcare to make more maternal resources available for the care of the child and mother. Therefore, further research is urgent for regional level and national level investigation. PMID:23113145

  2. Self-similar aftershock rates.

    PubMed

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise-an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes-the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting. PMID:27627324

  3. Nova reaction rates and experiments

    NASA Astrophysics Data System (ADS)

    Bishop, S.; Herlitzius, C.; Fiehl, J.

    2011-04-01

    Oxygen-neon novae form a subset of classical novae events known to freshly synthesize nuclei up to mass number A≲40. Because several gamma-ray emitters lie in this mass range, these novae are also interesting candidates for gamma-ray astronomy. The properties of excited states within those nuclei in this mass region play a critical role in determining the resonant (p,γ) reaction rates, themselves, largely unknown for the unstable nuclei. We describe herein a new Doppler shift lifetime facility at the Maier-Leibnitz tandem laboratory, Technische Universität München, with which we will map out important resonant (p,γ) nova reaction rates.

  4. Rate processes in gas phase

    NASA Technical Reports Server (NTRS)

    Hansen, C. F.

    1983-01-01

    Reaction-rate theory and experiment are given a critical review from the engineers' point of view. Rates of heavy-particle, collision-induced reaction in gas phase are formulated in terms of the cross sections and activation energies for reaction. The effect of cross section function shape and of excited state contributions to reaction both cause the slope of Arrhenius plots to differ from the true activation energy, except at low temperature. The master equations for chemically reacting gases are introduced, and dissociation and ionization reactions are shown to proceed primarily from excited states about kT from the dissociation or ionization limit. Collision-induced vibration, vibration-rotation, and pure rotation transitions are treated, including three-dimensional effects and conservation of energy, which have usually been ignored. The quantum theory of transitions at potential surface crossing is derived, and results are found to be in fair agreement with experiment in spite of some questionable approximations involved.

  5. Interaction of cholesterol with sphingomyelin in bilayer membranes: Evidence that the hydroxy group of sphingomyelin does not modulate the rate of cholesterol exchange between vesicles

    SciTech Connect

    Chucheng Kan; Zhongshi Ruan; Bittman, R. )

    1991-08-06

    Cholesterol undergoes exchange between membranes containing sphingomyelin at a much slower rate than between membranes lacking sphingomyelin. To investigate the role of the hydroxy group at the 3-position of sphingomyelin in the interaction between sphingomyelin and cholesterol, the authors have measured the rates of (4-{sup 14}C)cholesterol exchange between unilamellar vesicles prepared with N-alkyl group or with hydrogen. Vesicles prepared from 3-deoxy- and 3-0-methyl-N-stearoylsphingomyelin had the same rate of ({sup 14}C) cholesterol desorption. The half-times for exchange from vesicles prepared with 3-0-methyl- and 3-deoxy-N-stearoylsphingomyelins and 10 mol% of cholesterol were only slightly faster than that found from vesicles prepared from N-stearoylsphingomyelin and 10 mol% cholesterol. The rate of cholesterol desorption from vesicles could be accelerated by preparing vesicles from bulky 3-0-alkyl analogues of sphingomyelin. These data indicate that insertion of sterically bulky groups at the 3-position of sphingomyelin in place of hydroxy interferes markedly with the molecular packing of cholesterol and sphingomyelin in bilayer membranes; however, the hydroxy group of sphingomyelin is not critical for the strong interaction of cholesterol with sphingomyelin. These results suggest that van der Waals interactions are more important than hydrogen-bonding interactions involving the hydroxy group in contributing to tight lateral packing of cholesterol with sphingomyelin.

  6. Glucose Injections into the Dorsal Hippocampus or Dorsolateral Striatum of Rats Prior to T-Maze Training: Modulation of Learning Rates and Strategy Selection

    ERIC Educational Resources Information Center

    Canal, Clinton E.; Stutz, Sonja J.; Gold, Paul E.

    2005-01-01

    The present experiments examined the effects of injecting glucose into the dorsal hippocampus or dorsolateral striatum on learning rates and on strategy selection in rats trained on a T-maze that can be solved by using either a hippocampus-sensitive place or striatum-sensitive response strategy. Percentage strategy selection on a probe trial…

  7. Pharmacological modulation of gastric emptying rate of solids as measured by the carbon labelled octanoic acid breath test: influence of erythromycin and propantheline.

    PubMed Central

    Maes, B D; Hiele, M I; Geypens, B J; Rutgeerts, P J; Ghoos, Y F; Vantrappen, G

    1994-01-01

    The *C (13C or 14C) labelled octanoic acid breath test was recently developed to measure the gastric emptying rate of solids. This study aimed to investigate whether it is sensitive enough to detect pharmacologically induced changes in the gastric emptying rate. Nine healthy volunteers were studied in basal condition, after intravenous administration of 200 mg erythromycin, and after peroral administration of 30 mg propantheline. Erythromycin significantly enhanced gastric emptying in all subjects, with an increase of the gastric emptying coefficient (p = 0.0043) in eight of nine and a fall in both the gastric half emptying time (p = 0.0020) and the lag phase (p = 0.0044) in all nine. Propantheline significantly reduced the gastric emptying rate, with a decreased gastric emptying coefficient (p = 0.0007) and an increased gastric half emptying time (p = 0.0168) in all subjects, but no change in the lag phase (p = 0.1214). Further mathematical analysis showed that breath sampling at 15 minutes intervals over a four hour period is recommended to guarantee accuracy and the discriminative value of the breath test in various gastric emptying patterns. In conclusion the *C labelled octanoic acid breath test is sufficiently sensitive to show pharmacologically induced changes of gastric emptying rates of solids. PMID:8150342

  8. Growth rate for blackhole instabilities

    NASA Astrophysics Data System (ADS)

    Prabhu, Kartik; Wald, Robert

    2015-04-01

    Hollands and Wald showed that dynamic stability of stationary axisymmetric black holes is equivalent to positivity of canonical energy on a space of linearised axisymmetric perturbations satisfying certain boundary and gauge conditions. Using a reflection isometry of the background, we split the energy into kinetic and potential parts. We show that the kinetic energy is positive. In the case that potential energy is negative, we show existence of exponentially growing perturbations and further obtain a variational formula for the growth rate.

  9. Star ratings. Stars of wonder.

    PubMed

    Dawes, David

    2002-09-12

    Analysis of trusts that changed their star-rating over the past two years indicates that a change of chief executive was not a significant factor. The length of time in post and the experience of the chief executive were also insignificant. This has serious implications for the theory behind franchising and the evaluation of franchised trusts. Holding chief executives to account for the organisation's performance within their first 12 months is unlikely to be effective. PMID:12357738

  10. Low nutation-rate dampers

    NASA Technical Reports Server (NTRS)

    Tossman, B. E.

    1971-01-01

    Mission requirements plus spacecraft weight and power constraints often reduce the excitation frequency of a nutation damper below 1 cpm. Since attitude stability is determined by damper performance, maximum effectiveness at low rates is demanded. Presented are design considerations that low-frequency dampers require, along with descriptions of two low-frequency systems: the Direct Measurement Explorer 1 and the Small Astronomy Satellite A (SAS-A).

  11. 1993 Wholesale Power and Transmission Rate Schedules.

    SciTech Connect

    US Bonneville Power Administration

    1993-10-01

    Bonneville Power Administration 1993 Wholesale Power Rate Schedules and General Rate Schedule Provisions and 1993 Transmission Rate Schedules and General Transmission Rate Schedule Provisions, contained herein, were approved on an interim basis effective October 1, 1993. These rate schedules and provisions were approved by the Federal Energy Commission, United States Department of Energy, in September, 1993. These rate schedules and provisions supersede the Administration`s Wholesale Power Rate Schedules and General Rate Schedule Provisions and Transmission Rate Schedules and General Transmission Rate Schedule Provisions effective October 1, 1991.

  12. High rate manure supernatant digestion.

    PubMed

    Bergland, Wenche Hennie; Dinamarca, Carlos; Toradzadegan, Mehrdad; Nordgård, Anna Synnøve Røstad; Bakke, Ingrid; Bakke, Rune

    2015-06-01

    The study shows that high rate anaerobic digestion may be an efficient way to obtain sustainable energy recovery from slurries such as pig manure. High process capacity and robustness to 5% daily load increases are observed in the 370 mL sludge bed AD reactors investigated. The supernatant from partly settled, stored pig manure was fed at rates giving hydraulic retention times, HRT, gradually decreased from 42 to 1.7 h imposing a maximum organic load of 400 g COD L(-1) reactor d(-1). The reactors reached a biogas production rate of 97 g COD L(-1) reactor d(-1) at the highest load at which process stress signs were apparent. The yield was ∼0.47 g COD methane g(-1) CODT feed at HRT above 17 h, gradually decreasing to 0.24 at the lowest HRT (0.166 NL CH4 g(-1) CODT feed decreasing to 0.086). Reactor pH was innately stable at 8.0 ± 0.1 at all HRTs with alkalinity between 9 and 11 g L(-1). The first stress symptom occurred as reduced methane yield when HRT dropped below 17 h. When HRT dropped below 4 h the propionate removal stopped. The yield from acetate removal was constant at 0.17 g COD acetate removed per g CODT substrate. This robust methanogenesis implies that pig manure supernatant, and probably other similar slurries, can be digested for methane production in compact and effective sludge bed reactors. Denaturing gradient gel electrophoresis (DGGE) analysis indicated a relatively fast adaptation of the microbial communities to manure and implies that non-adapted granular sludge can be used to start such sludge bed bioreactors. PMID:25776915

  13. Atmospheric radiation flight dose rates

    NASA Astrophysics Data System (ADS)

    Tobiska, W. K.

    2015-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

  14. NPP ATMS Snowfall Rate Product

    NASA Technical Reports Server (NTRS)

    Meng, Huan; Ferraro, Ralph; Kongoli, Cezar; Wang, Nai-Yu; Dong, Jun; Zavodsky, Bradley; Yan, Banghua

    2015-01-01

    Passive microwave measurements at certain high frequencies are sensitive to the scattering effect of snow particles and can be utilized to retrieve snowfall properties. Some of the microwave sensors with snowfall sensitive channels are Advanced Microwave Sounding Unit (AMSU), Microwave Humidity Sounder (MHS) and Advance Technology Microwave Sounder (ATMS). ATMS is the follow-on sensor to AMSU and MHS. Currently, an AMSU and MHS based land snowfall rate (SFR) product is running operationally at NOAA/NESDIS. Based on the AMSU/MHS SFR, an ATMS SFR algorithm has been developed recently. The algorithm performs retrieval in three steps: snowfall detection, retrieval of cloud properties, and estimation of snow particle terminal velocity and snowfall rate. The snowfall detection component utilizes principal component analysis and a logistic regression model. The model employs a combination of temperature and water vapor sounding channels to detect the scattering signal from falling snow and derive the probability of snowfall (Kongoli et al., 2015). In addition, a set of NWP model based filters is also employed to improve the accuracy of snowfall detection. Cloud properties are retrieved using an inversion method with an iteration algorithm and a two-stream radiative transfer model (Yan et al., 2008). A method developed by Heymsfield and Westbrook (2010) is adopted to calculate snow particle terminal velocity. Finally, snowfall rate is computed by numerically solving a complex integral. NCEP CMORPH analysis has shown that integration of ATMS SFR has improved the performance of CMORPH-Snow. The ATMS SFR product is also being assessed at several NWS Weather Forecast Offices for its usefulness in weather forecast.

  15. Heart rate variability and heart rate recovery as prognostic factors

    PubMed Central

    GRAD, COSMIN

    2015-01-01

    Background and aim Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a number of HR interval. HRV can serve as measure of autonomic activity of sino-atrial node. The aim of the study was to determine the influence of certain clinical and paraclinical parameters on heart rate recovery after exercise in patients with ischemic heart disease and the relation with HRV using 24 h Holter monitoring. Methods The study included 46 patients who were submitted to cardiovascular exercise stress test and also to 24 h Holter EKG monitoring. Subjects had a mean age of 56.2±11.2 years, with a minimum of 25 and a maximum of 79 years. The study included 22 (47.8%) men and 24 (52.2%) women. Statistical analysis was performed using MedCalc software version 14.8.1. Multivariate analysis consisted of the construction of several multiple linear regression models. A p value of 0.05 was considered statistically significant. Results The HRV values (time domain) were all lower in the IHD compared with the group without coronary heart disease, even if the difference is not statistically significant. Also rest and maximal HR values were similar but during the test varies in the sense that those with IHD had higher values of rest and maximal HR and lower HRR, but not statistically significant. Conclusions HRV is a very easy and safe method if there is an available device and it is used for evaluation of the autonomic nervous system in many cardiovascular diseases, but also in other pathologies. In uncomplicated ischemic heart disease HRV is depressed, but not significant. HRR

  16. Modulation of the Active Complex Assembly and Turnover Rate by Protein–DNA Interactions in Cre–LoxP Recombination†,‡

    PubMed Central

    Martin, Shelley S.; Chu, Victor C.; Baldwin, Enoch

    2010-01-01

    Cre promotes recombination at the 34 bp LoxP sequence. Substitution of a critical C-G base pair in LoxP with an A-T base pair, to give LoxAT, reduced Cre binding in vitro and abolished recombination in vivo. We demonstrated that LoxAT can be recombined in vitro. However, Cre discriminates against this substrate both before and after DNA binding. The preference for LoxP over LoxAT is the result of reduced binding and a slower turnover rate, amplified by changes in cooperativity of complex assembly. With LoxAT, similar levels of substrate turnover required 2–2.5-fold higher protein–DNA concentrations compared to LoxP, but the sigmoidal behavior of the concentration dependence was more pronounced. Further, the Cre–LoxAT complexes reacted 4–5-fold more slowly. In the 2.3 Å resolution Cre–LoxAT complex structure, the major groove Arg259–guanine interaction was disrupted, explaining the reduced binding. Overall structural shifts and mobility changes indicate more favorable interactions between subunits, providing a hypothesis for the reduced turnover rate. Concomitant with the displacement of Arg259 from the DNA, adjacent charged residues Glu262 and Glu266 shifted to form salt bridges with the Arg259 guanidinium moiety. Substitution of Glu262 and Glu266 with glutamine increased Cre complex assembly efficiency and reaction rates with both LoxAT and LoxP, but diminished Cre’s ability to distinguish them. The increased rate of this variant suggests that DNA substrate binding and turnover are coupled. The improved efficiency, made at some expense of sequence discrimination, may be useful for enhancing recombination in vivo. PMID:12779336

  17. Event rates for WIMP detection

    SciTech Connect

    Vergados, J. D.; Moustakidis, Ch. C.; Oikonomou, V.

    2006-11-28

    The event rates for the direct detection of dark matter for various types of WIMPs are presented. In addition to the neutralino of SUSY models, we considered other candidates (exotic scalars as well as particles in Kaluza-Klein and technicolour theories) with masses in the TeV region. Then one finds reasonable branching ratios to excited states. Thus the detection of the WIMP can be made not only by recoil measurements, by measuring the de-excitation {gamma}-rays as well.

  18. Double White Dwarf Merger Rates

    NASA Astrophysics Data System (ADS)

    Toonen, Silvia; Nelemans, Gijs; Portegies Zwart, Simon

    2013-01-01

    Type Ia supernovae (SNe Ia) are very successfully used as standard candles on cosmological distance scales, but so far the nature of the progenitor(s) is unclear. A possible scenario for SNe Ia are merging carbon/oxygen white dwarfs with a combined mass exceeding the Chandrasekhar mass. We determine the theoretical rates and delay time distribution of these mergers for two different common envelope prescriptions and metallicities. The shape of the delay time distributions is rather insensitive to the assumptions. The normalization is a factor ~3-13 too low compared to observations.

  19. Depletion of tumour glutathione in vivo by buthionine sulphoximine: modulation by the rate of cellular proliferation and inhibition of cancer growth.

    PubMed Central

    Terradez, P; Asensi, M; Lasso de la Vega, M C; Puertes, I R; Viña, J; Estrela, J M

    1993-01-01

    We have investigated in Ehrlich-ascites-tumour-bearing mice the effect of buthionine sulphoximine (BSO), a selective inhibitor of GSH synthesis, on the rate of GSH depletion of tumour versus normal tissues and its relation to tumour cell proliferation. In normal tissues, GSH and GSSG remain unchanged or close to normal values during tumour growth, even at the last stage of growth when the animal is close to death. After administration of a single dose of BSO (4 mmol/kg), the rates of GSH depletion and recovery in the tumour and in several normal tissues are very different. BSO depletes GSH in cancer cells to a level of 0.3-0.4 mumol/g. The fall in GSH levels is faster when tumour cells do not proliferate actively. Four treatments of 4 mmol of BSO/kg at 48 h intervals induce a significant decrease (about 44%) in tumour growth. Our data show that the rate of BSO-induced GSH depletion in cancer cells depends on the stage of tumour growth, and that BSO administration also inhibits cancer-cell proliferation. A mechanism involving changes in protein kinase C activity and intracellular pH is proposed to explain the inhibition of cancer growth elicited by BSO. PMID:8503882

  20. 7 CFR 1980.423 - Interest rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... effect a permanent reduction in the interest rate of their B&I guaranteed loan at any time during the... interest rate for insured loans will be the rate in effect at the time the loan is approved or at the time... approving the lender's interest rate, the rate at which guaranteed loans are being sold or traded in...

  1. 48 CFR 42.704 - Billing rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACT ADMINISTRATION AND AUDIT SERVICES Indirect Cost Rates 42.704 Billing rates. (a) The contracting... final indirect cost rates also shall be responsible for determining the billing rates. (b) The... basis of information resulting from recent review, previous rate audits or experience, or...

  2. 7 CFR 4279.125 - Interest rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... applicant and may be either fixed or variable as long as it is a legal rate. Interest rates will not be more... market and pass interest-rate savings on to the borrower. (a) A variable interest rate agreed to by the.... The variable interest rate may be adjusted at different intervals during the term of the loan, but...

  3. 47 CFR 65.800 - Rate base.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Rate base. 65.800 Section 65.800 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERSTATE RATE OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Rate Base § 65.800 Rate base. The rate base...

  4. 47 CFR 65.800 - Rate base.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Rate base. 65.800 Section 65.800 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERSTATE RATE OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Rate Base § 65.800 Rate base. The rate base...

  5. 7 CFR 4279.125 - Interest rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... applicant and may be either fixed or variable as long as it is a legal rate. Interest rates will not be more... market and pass interest-rate savings on to the borrower. (a) A variable interest rate agreed to by the.... The variable interest rate may be adjusted at different intervals during the term of the loan, but...

  6. 9 CFR 391.2 - Basetime rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. (b) FSIS will calculate the benefits, travel and operating, overhead, and allowance for bad debt rate components of the...) Allowance for bad debt rate. Previous fiscal year's allowance for bad debt (for example, debt owed that...

  7. 9 CFR 391.2 - Basetime rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... travel and operating rate, plus the overhead rate, plus the allowance for bad debt rate. (b) FSIS will calculate the benefits, travel and operating, overhead, and allowance for bad debt rate components of the...) Allowance for bad debt rate. Previous fiscal year's allowance for bad debt (for example, debt owed that...

  8. 5 CFR 532.251 - Special rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Special rates. 532.251 Section 532.251 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.251 Special rates. (a) A lead agency, with the approval of OPM, may establish special rates for use...

  9. 7 CFR 1980.320 - Interest rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Interest rate. 1980.320 Section 1980.320 Agriculture... REGULATIONS (CONTINUED) GENERAL Rural Housing Loans § 1980.320 Interest rate. The interest rate must not... interest rate over the life of the loan. The rate shall be agreed upon by the borrower and the Lender...

  10. Multifractality and heart rate variability

    NASA Astrophysics Data System (ADS)

    Sassi, Roberto; Signorini, Maria Gabriella; Cerutti, Sergio

    2009-06-01

    In this paper, we participate to the discussion set forth by the editor of Chaos for the controversy, "Is the normal heart rate chaotic?" Our objective was to debate the question, "Is there some more appropriate term to characterize the heart rate variability (HRV) fluctuations?" We focused on the ≈24 h RR series prepared for this topic and tried to verify with two different techniques, generalized structure functions and wavelet transform modulus maxima, if they might be described as being multifractal. For normal and congestive heart failure subjects, the hq exponents showed to be decreasing for increasing q with both methods, as it should be for multifractal signals. We then built 40 surrogate series to further verify such hypothesis. For most of the series (≈75%-80% of cases) multifractality stood the test of the surrogate data employed. On the other hand, series coming from patients in atrial fibrillation showed a small, if any, degree of multifractality. The population analyzed is too small for definite conclusions, but the study supports the use of multifractal series to model HRV. Also it suggests that the regulatory action of autonomous nervous system might play a role in the observed multifractality.

  11. Reconnection rates of magnetic fields

    SciTech Connect

    Park, W.; Monticello, D.A.; White, R.B.

    1983-05-01

    The Sweet-Parker and Petschek scalings of magnetic reconnection rate are modified to include the effect of the viscosity. The modified scalings show that the viscous effect can be important in high-..beta.. plasmas. The theoretical reconnection scalings are compared with numerical simulation results in a tokamak geometry for three different cases: a forced reconnection driven by external coils, the nonlinear m = 1 resistive internal kink, and the nonlinear m = 2 tearing mode. In the first two cases, the numerical reconnection rate agrees well with the modified Sweet-Parker scaling, when the viscosity is sufficiently large. When the viscosity is negligible, a steady state which was assumed in the derivation of the reconnection scalings is not reached and the current sheet in the reconnection layer either remains stable through sloshing motions of the plasma or breaks up to higher m modes. When the current sheet remains stable, a rough comparison with the Sweet-Parker scaling is obtained. In the nonlinear m = 2 tearing mode case where the instability is purely resistive, the reconnection occurs on the slower dissipation time scale (Psi/sub s/ approx. eta). In addition, experimental data of the nonlinear m = 1 resistive internal kink in tokamak discharges are analyzed and are found to give reasonable agreement with the modified Sweet-Parker scaling.

  12. 7 CFR 1980.320 - Interest rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... exceed the established applicable usury rate. Loans guaranteed under this subpart must bear a fixed interest rate over the life of the loan. The rate shall be agreed upon by the borrower and the Lender...

  13. 7 CFR 1980.320 - Interest rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... exceed the established, applicable usury rate. Loans guaranteed under this subpart must bear a fixed interest rate over the life of the loan. The rate shall be agreed upon by the borrower and the Lender...

  14. 76 FR 6762 - Publication of Depreciation Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-08

    ... December 31, 2009. DATES: These rates are effective immediately and will remain in effect until rates are... Depreciation rate 1. Land and Support Assets: a. Motor vehicles 16.00 b. Aircraft 11.70 c. Special...

  15. 78 FR 73821 - Publication of Depreciation Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... December 31, 2012. DATES: These rates are effective immediately and will remain in effect until rates are... December 31, 2012 Depreciation Telecommunications plant category rate 1. Land and Support Assets: a....

  16. Modulation of the hydrolysis rate of the ADP-insensitive phosphoenzyme of the sarcoplasmic reticulum ATPase by H+ and Mg2+.

    PubMed

    Wakabayashi, S; Ogurusu, T; Shigekawa, M

    1987-07-01

    Effects of H+ and Mg2+ on the hydrolysis rate of the ADP-insensitive phosphoenzyme intermediate (E2P) of the sarcoplasmic reticulum ATPase were investigated at 6 degrees C in the presence and absence of K+. In the absence of K+, the pH dependence of the E2P hydrolysis rate obtained in the absence of divalent cations showed a bell-shaped profile with an optimum at pH 9. At neutral pH, Mg2+ or other divalent cations accelerated the E2P hydrolysis while they strongly inhibited it at alkaline pH. The accelerating effect occurred on the cytoplasmic side of the membrane whereas the inhibitory effect occurred on the luminal side of the membrane, presumably at the low affinity calcium transport sites. The presence of Mg2+ or other divalent cations, therefore, shifted the pH activity profile to the acidic side while the magnitude of this shift and the activity obtained at the optimum pH depended on the species and the concentration of the divalent cation used. Simulation of a set of the pH activity curves obtained in 0 to 40 mM Mg2+ suggests that the marked activation of E2P hydrolysis by high Mg2+ observed at neutral pH is primarily caused by a Mg2+-induced increase in the dissociation constant of the ionizing group(s) rather than a markedly increased rate constant for E2P hydrolysis. In the presence of K+, the stimulatory effect of Mg2+ at pH 7 was less pronounced but its inhibitory effect at pH 9 was similar to that observed in the absence of K+. These effects of Mg2+ and other divalent cations should be taken into account when the role of H+ in the ATPase reaction is investigated. PMID:2954958

  17. Glucose injections into the dorsal hippocampus or dorsolateral striatum of rats prior to T-maze training: Modulation of learning rates and strategy selection

    PubMed Central

    Canal, Clinton E.; Stutz, Sonja J.; Gold, Paul E.

    2005-01-01

    The present experiments examined the effects of injecting glucose into the dorsal hippocampus or dorsolateral striatum on learning rates and on strategy selection in rats trained on a T-maze that can be solved by using either a hippocampus-sensitive place or striatum-sensitive response strategy. Percentage strategy selection on a probe trial (Pcrit) administered after rats achieved criterion (nine of 10 correct choices) varied by group. All groups predominately exhibited a response strategy on a probe trial administered after overtraining, i.e., after 90 trials. In experiment 1, rats that received intrahippocampal glucose injections showed enhanced acquisition of the T-maze and showed increased use of response solutions at Pcrit compared with that of unimplanted and artificial cerebral spinal fluid (aCSF)-treated groups. These findings suggest that glucose enhanced hippocampal functions to accelerate the rate of learning and the early adoption of a response strategy. In experiment 2, rats that received intrastriatal glucose injections exhibited place solutions early in training and reached criterion more slowly than did aCSF controls, with learning rates comparable to those of unoperated and operated-uninjected controls. Relative to unoperated, operated-uninjected and glucose-injected rats, rats that received intrastriatal aCSF injections showed enhanced acquisition of the T-maze and increased use of response solutions at Pcrit. The unexpected enhanced acquisition seen after striatal aCSF injections suggests at least two possible interpretations: (1) aCSF impaired striatal function, thereby releasing competition with the hippocampus and ceding control over learning to the hippocampus during early training trials; and (2) aCSF enhanced striatal functioning to facilitate striatal-sensitive learning. With either interpretation, the results indicate that intrastriatal glucose injections compensated for the aCSF-induced effect. Finally, enhanced acquisition regardless

  18. 47 CFR 64.1801 - Geographic rate averaging and rate integration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Geographic rate averaging and rate integration... CARRIER SERVICES (CONTINUED) MISCELLANEOUS RULES RELATING TO COMMON CARRIERS Geographic Rate Averaging and Rate Integration § 64.1801 Geographic rate averaging and rate integration. (a) The rates charged...

  19. The Vocational Adaptation Rating Scales.

    PubMed

    Malgady, R G; Barcher, P R

    1982-01-01

    The Vocational Adaptation Rating Scales (VARS) were developed to provide a comprehensive assessment of maladaptive social behavior related to vocational success, but not directly measuring job performance of mentally retarded workers. Psychometric information derived from the VARS is useful for developing individualized educational plans (IEPs) for compliance with Public Law 94-142; for program, worker or curriculum evaluations; and for predicting placement of workers in vocational training. Research indicates that VARS scores are internally consistent, moderately correlated with other vocational measures, unbiased with respect to sex and age differences, and independent of IQ. Inter-rater reliability is acceptable, and VARS profiles are accurate predictors of level of sheltered workshop placement of mentally retarded workers, independent of IQ, sex and age. Unlike other instruments, the VARS offers a profile of social behavior in a vocational context. PMID:7168570

  20. Calculation of molecular excitation rates

    NASA Technical Reports Server (NTRS)

    Flynn, George

    1993-01-01

    State-to-state collisional excitation rates for interstellar molecules observed by radio astronomers continue to be required to interpret observed line intensities in terms of local temperatures and densities. A problem of particular interest is collisional excitation of water which is important for modeling the observed interstellar masers. In earlier work supported by a different NASA Grant, excitation of water in collisions with He atoms was studied; after many years of successively more refined calculations that problem now seems to be well understood, and discrepancies with earlier experimental data for related (pressure broadening) phenomena are believed to reflect experimental errors. Because of interstellar abundances, excitation by H2, the dominant interstellar species, is much more important than excitation by He, although it has been argued that rates for excitation by these are similar. Under the current grant theoretical study of this problem has begun which is greatly complicated by the additional degrees of freedom which must be included both in determining the interaction potential and also in the molecular scattering calculation. We have now computed the interaction forces for nearly a thousand molecular geometries and are close to having an acceptable global fit to these points which is necessary for the molecular dynamics calculations. Also, extensive modifications have been made to the molecular scattering code, MOLSCAT. These included coding the rotational basis sets and coupling matrix elements required for collisions of an asymmetric top with a linear rotor. A new method for numerical solution of the coupled equations has been incorporated. Because of the long-ranged nature of the water-hydrogen interaction it is necessary to integrate the equations to rather large intermolecular separations, and the integration methods previously available in MOLSCAT are not ideal for such cases. However, the method used by Alexander in his HIBRIDON code is

  1. Light-mediated modulation of helix angle and rate of seminal root tip movement determines root morphology of young rice seedlings.

    PubMed

    Chen, Hsiang-Wen; Shao, Ko-Hsuan; Wang, Shu-Jen

    2016-01-01

    Seminal root growth is one of the factors to determine rice seedling establishment. Our previous reports showed light can induce Z-type wavy root and coiling root morphology in several rice (Oryza sativa L.) varieties, and the regulated Z-type and unregulated coil seminal roots were resulted by different circumnutational trajectories. Moreover, the light-induced seminal root waving was conducted by an NO-dependent signaling pathway. In order to further reveal the difference of root tip movement between straight and wavy seminal roots; here, the root tip movement trajectories of Tainung 67 variety (TNG67; presented straight root in light conditions) and Taichung Native 1 (TCN1; presented Z-type wavy root in light) were recorded and analyzed in both white light and dark (dim far-red light was applied in dark for taking time-lapse photography) conditions. The results showed the root tip movement of both rice varieties in low intensity of dim far-red light conditions were followed the circumnutation path. However, the stimuli of high intensity of white light would increase the root helix angle in TCN1 seedlings but not in TNG67. In addition, slowing down the rate of root helix was induced by white light treatment in TCN1 but not in TNG67 seedlings. In conclusion, changes of TCN1 rice seminal root morphology from straight to wavy type stimulated by light was resulted by both helix angle increasing and circumnutation rate slowing of root tip movement. PMID:26829414

  2. Minimizing Variation in Outdoor CPV Power Ratings (Presentation)

    SciTech Connect

    Muller, M.

    2011-04-01

    Presented at the 7th International Conference on Concentrating Photovoltaic Systems (CPV-7), 4-6 April 2011, Las Vegas, Nevada. The CPV community has agreed to have both indoor and outdoor power ratings at the module level. The indoor rating provides a repeatable measure of module performance as it leaves the factory line while the outdoor rating provides a measure of true performance under real world conditions. The challenge with an outdoor rating is that the spectrum, temperature, wind speed, etc are constantly in flux and therefore the resulting power rating varies from day to day and month to month. This work examines different methodologies for determining the outdoor power rating with the goal of minimizing variation even if data are collected under changing meteorological conditions.

  3. [The urbanization rate in Turkey].

    PubMed

    Widy-kwiatkowska, J

    1994-01-01

    Data from the annual statistical report on Turkey for 1990 and the results of research from 1985 and 1990 were utilized and compared with the trends of urbanization observed in the 1969 work of Z. Siemek on Turkey. In 1990, Turkey had about 56.5 million people with an average annual natural growth rate of 2.6% and an unemployment rate of 16%. The rural population made up 41% of the total populace. Urbanization was on the increase, from 47% in 1980, to 55% in 1985, and 59% in 1990. Urbanization in Ankara, because of its location in the center of Turkey, was particularly active in the regions of Anatolia, although it was still isolated in terms of intensified development. Istanbul's The population of Istanbul numbered 6,754,000 people in 1990. It is the major industrial center of the country with about 20% of industrial plants and 17% of the work force in the manufacturing industry. The largest degree of urbanization was demonstrated by Ankara: in 1927 its population numbered only 74,500 people, in 1965 about 902,000 inhabitants, and in 1990 about 2,837,000 people. During the period 1985-90, only 2 out of 73 provinces experienced a decline of the urban population: Kirikkale from 70.4% to 69.7% (because of the dynamic development of the Central region) and Istanbul from 95.4% to 92.4%. During this same period, Kirikkale's urban population, compared with the nation's total urban population, also declined from 0.9% to 0.7% because of immigration of both urban and rural people to other, more attractive provinces. The growth of urban population in the province of Istanbul varied from 1% to 10% during the period and made up 20.3% of the entire urban population. The Central region underwent a large degree of urbanization characterized by industrial-agricultural development. The city of Sivas became a center of communication. In the Central and Kurd regions, urbanization proceeded fast owing to the development of the Black Sea region and the immigration of Kurds from Iraq

  4. Development of digital flow control system for multi-channel variable-rate sprayers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precision modulation of nozzle flow rates is a critical step for variable-rate spray applications in orchards and ornamental nurseries. An automatic flow rate control system activated with microprocessors and pulse width modulation (PWM) controlled solenoid valves was developed to control flow rates...

  5. Rate of runaway evaporative cooling

    SciTech Connect

    Groep, J. van de; Straten, P. van der; Vogels, J. M.

    2011-09-15

    Evaporative cooling is a process that is essential in creating Bose-Einstein condensates in dilute atomic gasses. This process has often been simulated based on a model using a truncated Boltzmann distribution. This model assumes that the energy distribution up to the threshold energy can still be described by a Boltzmann distribution: it assumes detailed balance up to the threshold energy. However, the evolution of the distribution function in time is not taken into account. Here we solve the kinetic Boltzmann equation for a gas undergoing evaporative cooling in a harmonic and linear trap in order to determine the evolution of the energy distribution. The magnitude of the discrepancy with the truncated Boltzmannmodel is calculated by including a polynomial expansion of the distribution function. We find that up to 35% fewer particles are found in the high-energy tail of the distribution with respect to the truncated Boltzmann distribution and up to 15% more collisions are needed to reach quantum degeneracy. Supported by a detailed investigation of the particle loss rate at different energies, we conclude that the limited occupation of high-energy states during the evaporation process causes the lowering of the evaporation speed and efficiency.

  6. Flow rate logging seepage meter

    NASA Technical Reports Server (NTRS)

    Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

    1996-01-01

    An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

  7. Failure rate analysis using GLIMMIX

    SciTech Connect

    Moore, L.M.; Hemphill, G.M.; Martz, H.F.

    1998-12-01

    This paper illustrates use of a recently developed SAS macro, GLIMMIX, for implementing an analysis suggested by Wolfinger and O`Connell (1993) in modeling failure count data with random as well as fixed factor effects. Interest in this software tool arose from consideration of modernizing the Failure Rate Analysis Code (FRAC), developed at Los Alamos National Laboratory in the early 1980`s by Martz, Beckman and McInteer (1982). FRAC is a FORTRAN program developed to analyze Poisson distributed failure count data as a log-linear model, possibly with random as well as fixed effects. These statistical modeling assumptions are a special case of generalized linear mixed models, identified as GLMM in the current statistics literature. In the nearly 15 years since FRAC was developed, there have been considerable advances in computing capability, statistical methodology and available statistical software tools allowing worthwhile consideration of the tasks of modernizing FRAC. In this paper, the approaches to GLMM estimation implemented in GLIMMIX and in FRAC are described and a comparison of results for the two approaches is made with data on catastrophic time-dependent pump failures from a report by Martz and Whiteman (1984). Additionally, statistical and graphical model diagnostics are suggested and illustrated with the GLIMMIX analysis results.

  8. Retention Rate by Ethnicity. Information Capsule.

    ERIC Educational Resources Information Center

    Baldwin, Anne

    This document discusses retention rate based on ethnicity for Miami-Dade Community College (M-DCC) for December 2002. The study found that the 2001 Fall-Spring retention rates increased among all ethnic groups. The total college retention rate rose by 2.7 percentage points to 75.2%. Among individual groups, the highest retention rate of 76.9% was…

  9. 38 CFR 36.4312 - Interest rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... result in a change in either direction of more than one percentage point from the interest rate in effect... such loans either bear interest at a rate that is agreed upon by the veteran and the lender, or bear interest at a rate not in excess of a rate established by the Secretary. The Secretary may, from time...

  10. 18 CFR 704.39 - Discount rate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rate in effect immediately prior to the effective date of this section, and that rate shall continue to... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Discount rate. 704.39... STANDARDS AND PROCEDURES Standards for Plan Formulation and Evaluation § 704.39 Discount rate. (a)...

  11. 18 CFR 284.10 - Rates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... has the effect of guaranteeing revenue. Such rate must separately identify cost components... General Provisions and Conditions § 284.10 Rates. (a) Applicability. Any rate charged for transportation service under subparts B and G of this part must be established under a rate schedule that is filed...

  12. 18 CFR 284.10 - Rates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... has the effect of guaranteeing revenue. Such rate must separately identify cost components... General Provisions and Conditions § 284.10 Rates. (a) Applicability. Any rate charged for transportation service under subparts B and G of this part must be established under a rate schedule that is filed...

  13. 38 CFR 36.4312 - Interest rates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... result in a change in either direction of more than one percentage point from the interest rate in effect... such loans either bear interest at a rate that is agreed upon by the veteran and the lender, or bear interest at a rate not in excess of a rate established by the Secretary. The Secretary may, from time...

  14. 18 CFR 704.39 - Discount rate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... rate in effect immediately prior to the effective date of this section, and that rate shall continue to... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discount rate. 704.39... STANDARDS AND PROCEDURES Standards for Plan Formulation and Evaluation § 704.39 Discount rate. (a)...

  15. 7 CFR 953.253 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 953.253 Section 953.253 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Assessment Rates § 953.253 Assessment rate. On and after June 1, 1998, an assessment rate of...

  16. 7 CFR 953.253 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 953.253 Section 953.253 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Assessment Rates § 953.253 Assessment rate. On and after June 1, 1998, an assessment rate of...

  17. 7 CFR 953.253 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 953.253 Section 953.253 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Assessment Rates § 953.253 Assessment rate. On and after June 1, 1998, an assessment rate of...

  18. 7 CFR 953.253 - Assessment rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Assessment rate. 953.253 Section 953.253 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... STATES Assessment Rates § 953.253 Assessment rate. On and after June 1, 1998, an assessment rate of...

  19. 7 CFR 923.236 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 923.236 Section 923.236 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Assessment Rate § 923.236 Assessment rate. On and after April 1, 2007, an assessment rate of $0.40 per ton is established for the Washington Cherry...

  20. 7 CFR 915.235 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 915.235 Section 915.235 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 915.235 Assessment rate. On and after April 1, 2010, an assessment rate of $0.37 per...

  1. 7 CFR 905.235 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 905.235 Section 905.235 Agriculture... TANGELOS GROWN IN FLORIDA Assessment Rates § 905.235 Assessment rate. On and after August 1, 2007, an assessment rate of $0.0072 per 4/5 bushel carton or equivalent is established for Florida citrus...

  2. How Boards and Presidents Influence Credit Ratings

    ERIC Educational Resources Information Center

    Kedem, Karen

    2011-01-01

    Moody's Investors Service provides credit ratings for hundreds of private and public colleges and universities--ratings that can strongly influence the interest rates higher-education institutions can obtain when they want to borrow money. How colleges are governed and managed are key determinants of those credit ratings, especially in an…

  3. 7 CFR 3575.33 - Interest rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... negotiated between the lender and the borrower. They may be either fixed or variable rates. Interest rates... business and are subject to Agency review and approval. (b) Variable rate publication. A variable interest... more often than quarterly). (2) The lender must incorporate within the variable rate note,...

  4. 7 CFR 1779.33 - Interest rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... will be negotiated between the lender and the borrower. They may be either fixed or variable rates... course of business and are subject to Agency review and approval. (b) Variable rate publication. A variable interest rate must be tied to a base rate published periodically in a recognized national...

  5. 7 CFR 916.234 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 916.234 Section 916.234 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 916.234 Assessment rate. On and after March 1, 2009, an assessment rate of $0.0175 per...

  6. 7 CFR 929.236 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 929.236 Section 929.236 Agriculture... LONG ISLAND IN THE STATE OF NEW YORK Assessment Rate § 929.236 Assessment rate. On and after September 1, 2006, an assessment rate of $.28 per barrel is established for cranberries....

  7. 7 CFR 923.236 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 923.236 Section 923.236 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Assessment Rate § 923.236 Assessment rate. On and after April 1, 2012, an assessment rate of $0.18 per ton is established for the Washington Cherry...

  8. 7 CFR 905.235 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 905.235 Section 905.235 Agriculture... TANGELOS GROWN IN FLORIDA Assessment Rates § 905.235 Assessment rate. On and after August 1, 2007, an assessment rate of $0.0072 per 4/5 bushel carton or equivalent is established for Florida citrus...

  9. 7 CFR 905.235 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 905.235 Section 905.235 Agriculture... TANGELOS GROWN IN FLORIDA Assessment Rates § 905.235 Assessment rate. On and after August 1, 2007, an assessment rate of $0.0072 per 4/5 bushel carton or equivalent is established for Florida citrus...

  10. 7 CFR 916.234 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 916.234 Section 916.234 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 916.234 Assessment rate. On and after March 1, 2010, an assessment rate of $0.0280 per...

  11. 7 CFR 915.235 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 915.235 Section 915.235 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 915.235 Assessment rate. On and after April 1, 2012, an assessment rate of $0.25 per...

  12. 7 CFR 905.235 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 905.235 Section 905.235 Agriculture... TANGELOS GROWN IN FLORIDA Assessment Rates § 905.235 Assessment rate. On and after August 1, 2007, an assessment rate of $0.0072 per 4/5 bushel carton or equivalent is established for Florida citrus...

  13. 7 CFR 915.235 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 915.235 Section 915.235 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 915.235 Assessment rate. On and after April 1, 2010, an assessment rate of $0.37 per...

  14. 7 CFR 915.235 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 915.235 Section 915.235 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 915.235 Assessment rate. On and after April 1, 2005, an assessment rate of $0.27 per...

  15. 7 CFR 930.200 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 930.200 Section 930.200 Agriculture... MICHIGAN, NEW YORK, PENNSYLVANIA, OREGON, UTAH, WASHINGTON, AND WISCONSIN Assessment Rates § 930.200 Assessment rate. On and after October 1, 2010, the assessment rate imposed on handlers shall be $0.0075...

  16. 7 CFR 984.347 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 984.347 Section 984.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 984.347 Assessment rate. On and after September 1, 2011, an assessment rate of $0.0175...

  17. 7 CFR 984.347 - Assessment rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Assessment rate. 984.347 Section 984.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 984.347 Assessment rate. On and after September 1, 2013, an assessment rate of $0.0189...

  18. 7 CFR 989.347 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 989.347 Section 989.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... CALIFORNIA Assessment Rates § 989.347 Assessment rate. On and after August 1, 2010, an assessment rate of...

  19. 7 CFR 989.347 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 989.347 Section 989.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Assessment Rates § 989.347 Assessment rate. On and after August 1, 2005, an assessment rate of...

  20. 7 CFR 989.347 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 989.347 Section 989.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Assessment Rates § 989.347 Assessment rate. On and after August 1, 2010, an assessment rate of...

  1. 7 CFR 993.347 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 993.347 Section 993.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 993.347 Assessment rate. On and after August 1, 2011, an assessment rate of $0.22 per...

  2. 7 CFR 993.347 - Assessment rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Assessment rate. 993.347 Section 993.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 993.347 Assessment rate. On and after August 1, 2011, an assessment rate of $0.22 per...

  3. 7 CFR 984.347 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 984.347 Section 984.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 984.347 Assessment rate. On and after September 1, 2009, an assessment rate of $0.0177...

  4. 7 CFR 993.347 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 993.347 Section 993.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 993.347 Assessment rate. On and after August 1, 2009, an assessment rate of $0.16 per...

  5. 7 CFR 993.347 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 993.347 Section 993.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 993.347 Assessment rate. On and after August 1, 2010, an assessment rate of $0.27 per...

  6. 7 CFR 989.347 - Assessment rate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 989.347 Section 989.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Assessment Rates § 989.347 Assessment rate. On and after August 1, 2005, an assessment rate of...

  7. 7 CFR 993.347 - Assessment rate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 993.347 Section 993.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 993.347 Assessment rate. On and after August 1, 2011, an assessment rate of $0.22 per...

  8. 7 CFR 984.347 - Assessment rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 984.347 Section 984.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 984.347 Assessment rate. On and after September 1, 2011, an assessment rate of $0.0175...

  9. 7 CFR 984.347 - Assessment rate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 984.347 Section 984.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 984.347 Assessment rate. On and after September 1, 2010, an assessment rate of $0.0174...

  10. 7 CFR 989.347 - Assessment rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Assessment rate. 989.347 Section 989.347 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... CALIFORNIA Assessment Rates § 989.347 Assessment rate. On and after August 1, 2010, an assessment rate of...

  11. Dual-Rate Transmission Reduces Weather Effects

    NASA Technical Reports Server (NTRS)

    Posner, E. C.

    1984-01-01

    Scheme ensures maximum data received on average. Dual-rate scheme for maximizing data returned during spacecraft mission, adaptable, as is or with modifications, to high-frequency terrestrial data transmission. Data rate fixed in advance at minimum value guarantees reasonable prospect of success during bad weather. Dualrate strategy yields net data rate 2.5 times best achievable with single transmission rate.

  12. 10 CFR 903.23 - Rate extensions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Rate Adjustments and Extensions for the Alaska, Southeastern, Southwestern, and Western Area Power Administrations § 903.23 Rate extensions. (a) The following regulations shall apply to the extension of rates... 10 Energy 4 2010-01-01 2010-01-01 false Rate extensions. 903.23 Section 903.23 Energy...

  13. 5 CFR 532.251 - Special rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... area (or part thereof) specified. (h) The scheduled special rate payable under this section may not, at... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.251 Special rates. (a) A lead agency, with the approval of OPM,...

  14. Nitramine propellants. [gun propellant burning rate

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D. (Inventor)

    1978-01-01

    Nitramine propellants without a pressure exponent shift in the burning rate curves are prepared by matching the burning rate of a selected nitramine or combination of nitramines within 10% of burning rate of a plasticized active binder so as to smooth out the break point appearance in the burning rate curve.

  15. 7 CFR 1779.33 - Interest rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... will be negotiated between the lender and the borrower. They may be either fixed or variable rates... course of business and are subject to Agency review and approval. (b) Variable rate publication. A variable interest rate must be tied to a base rate published periodically in a recognized national...

  16. 7 CFR 3575.33 - Interest rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... negotiated between the lender and the borrower. They may be either fixed or variable rates. Interest rates... business and are subject to Agency review and approval. (b) Variable rate publication. A variable interest... more often than quarterly). (2) The lender must incorporate within the variable rate note,...

  17. 9 CFR 592.510 - Basetime rate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the allowance for bad debt rate. (b) FSIS will calculate the benefits, travel and operating, overhead, and allowance for bad debt rate components of the basetime rate, using the following formulas: (1... the calendar year's percentage of inflation. (4) Allowance for bad debt rate. Previous fiscal...

  18. 9 CFR 592.510 - Basetime rate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the allowance for bad debt rate. (b) FSIS will calculate the benefits, travel and operating, overhead, and allowance for bad debt rate components of the basetime rate, using the following formulas: (1... the calendar year's percentage of inflation. (4) Allowance for bad debt rate. Previous fiscal...

  19. 78 FR 62627 - Sam Rayburn Dam Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ...The U.S. Department of Energy Deputy Secretary has approved and placed into effect on an interim basis Rate Order No. SWPA-67, which increases the power rate for the Sam Rayburn Dam (Rayburn) project pursuant to the Rayburn rate schedule (SRD-13) to supersede the existing rate...

  20. Base Rates: Both Neglected and Intuitive

    ERIC Educational Resources Information Center

    Pennycook, Gordon; Trippas, Dries; Handley, Simon J.; Thompson, Valerie A.

    2014-01-01

    Base-rate neglect refers to the tendency for people to underweight base-rate probabilities in favor of diagnostic information. It is commonly held that base-rate neglect occurs because effortful (Type 2) reasoning is required to process base-rate information, whereas diagnostic information is accessible to fast, intuitive (Type 1) processing…