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Sample records for size groups delay

  1. Group Delay of High Q Antennas

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Pedersen, Gert Frølund

    2013-01-01

    Group Delay variations versus frequency is an essential factor which can cause distortion and degradation in the signals. Usually this is an issue in wideband communication systems, such as satellite communication systems, which are used for transmitting wideband data. However, group delay can also...... become an issue, when working with high Q antennas, because of the steep phase shift over the frequency. In this paper, it is measured how large group delay variations can become, when going from a low Q antenna to a high Q antenna. The group delay of a low Q antenna is shown to be around 1.3 ns, whereas...... a high Q antenna has group delay of around 22 ns. It is due to this huge group delay variation characteristics of high Q antennas, that signal distortion might occur in the radio system with high Q antennas....

  2. Nuclear size and cell division delay

    International Nuclear Information System (INIS)

    Bird, R.P.

    1986-01-01

    Radiation-induced division delay has been linked to damage at the nuclear envelope. Further, cells in G 2 phase are drastically arrested by high LET radiation such that single particles traversing cell nuclei may produce measurable division delay. A modest effort was initiated using two related cell lines of different size, near-diploid cells and near-tetraploid cells of Chinese hamster origin, to compare their sensitivity for radiation-induced division delay. If the nuclear surface is the critical target, then a larger nuclear cross-section presented to an alpha-particle beam should exhibit delay induced by a lesser particle fluence. Preliminary estimates of the extent of delay in asynchronous cultures following low doses of gamma-irradiation or of alpha-irradiation were made by in-situ observation of the time of onset of mitosis and by fixation and staining of cultures to determine the mitotic index as a function of time after irradiation. The basic approach to evaluating division delay will be to use Colecemid to accumulate mitotic cells over a period of time

  3. MODICO, 1-D Time-Dependent 1 Group, 2 Group Neutron Diffusion with Delayed Neutron Precursors

    International Nuclear Information System (INIS)

    Camiciola, P.; Cundari, D.; Montagnini, B.

    1992-01-01

    1 - Description of program or function: The program solves the 1-D time-dependent one and two group coarse-mesh neutron diffusion equations, coupled with the equations for the delayed-neutron precursor, in plane geometry. 2 - Method of solution: The program is based on a simple coarse-mesh cubic approximation formula for the spatial behaviour of the flux inside each interval. An implicit scheme (the time-integrated method) is used for the advancement of the solution. The resulting (block three-diagonal) matrix is inverted at each time step by Thomas' method. 3 - Restrictions on the complexity of the problem: Number of coarse- mesh intervals LE 80; number of material regions LE 10; number of delayed-neutron precursor groups LE 10. Typical mesh sizes range from 5 cm to 20 cm; typical step length (non-prompt critical transients) ranges from 0.005 to 0.1 seconds

  4. A general formula considering one group delayed neutron under nonequilibrium condition

    International Nuclear Information System (INIS)

    Li Haofeng; Chen Wenzhen; Zhu Qian; Luo Lei

    2008-01-01

    A general neutron breeder formula is developed when the reactor does not reach the steady state and the reactivity changes in phase. This formula can be used to calculate the results of six groups delayed neutron model through a way of amending λ in one group delayed neutron model. The analysis shows that the solution of amended single group delayed neutron model is approximately equal to that of six-group delayed neutron model, and the amended model meets the engineering accuracy. (authors)

  5. Information about the new 8-group delayed neutron set preparation

    International Nuclear Information System (INIS)

    Svarny, J.

    1998-01-01

    Some comments to the present state concerning delayed neutron data preparation is given and preliminary analysis of the new 8-group delayed data (relative abundances) is presented. Comparisons of the 8-group to 6-group set is given for rod drop experiment (Unit 1, Cycle 14, NPP Dukovany).(Author)

  6. Negative group delay for Dirac particles traveling through a potential well

    International Nuclear Information System (INIS)

    Chen Xi; Li Chunfang

    2003-01-01

    The properties of group delay for Dirac particles traveling through a potential well are investigated. A necessary condition is put forward for the group delay to be negative. It is shown that this negative group delay is closely related to its anomalous dependence on the width of the potential well. In order to demonstrate the validity of stationary-phase approach, numerical simulations are made for a Gaussian-shaped temporal wave packet. A restriction to the potential-well's width is obtained that is necessary for the wave packet to remain distortionless in the traveling. Numerical comparison shows that the relativistic group delay is larger than its corresponding nonrelativistic one

  7. Critical appraisal of arguments for the delayed-start design proposed as alternative to the parallel-group randomized clinical trial design in the field of rare disease.

    Science.gov (United States)

    Spineli, Loukia M; Jenz, Eva; Großhennig, Anika; Koch, Armin

    2017-08-17

    A number of papers have proposed or evaluated the delayed-start design as an alternative to the standard two-arm parallel group randomized clinical trial (RCT) design in the field of rare disease. However the discussion is felt to lack a sufficient degree of consideration devoted to the true virtues of the delayed start design and the implications either in terms of required sample-size, overall information, or interpretation of the estimate in the context of small populations. To evaluate whether there are real advantages of the delayed-start design particularly in terms of overall efficacy and sample size requirements as a proposed alternative to the standard parallel group RCT in the field of rare disease. We used a real-life example to compare the delayed-start design with the standard RCT in terms of sample size requirements. Then, based on three scenarios regarding the development of the treatment effect over time, the advantages, limitations and potential costs of the delayed-start design are discussed. We clarify that delayed-start design is not suitable for drugs that establish an immediate treatment effect, but for drugs with effects developing over time, instead. In addition, the sample size will always increase as an implication for a reduced time on placebo resulting in a decreased treatment effect. A number of papers have repeated well-known arguments to justify the delayed-start design as appropriate alternative to the standard parallel group RCT in the field of rare disease and do not discuss the specific needs of research methodology in this field. The main point is that a limited time on placebo will result in an underestimated treatment effect and, in consequence, in larger sample size requirements compared to those expected under a standard parallel-group design. This also impacts on benefit-risk assessment.

  8. Use of one delayed-neutron precursor group in transient analysis

    International Nuclear Information System (INIS)

    Diamond, D.J.

    1983-01-01

    In most reactor dynamics calculations six groups of delayed-neutron precursors are usually accounted for. However, under certain circumstances it may be advantageous to simplify the calculation and utilize a single delayed-neutron group. The motivation for going to one precursor group is economy. For LWR transient codes that use point kinetics the equations are solved very rapidly and six precursor groups should always be used. However, codes with spatially dependent neutron kinetics are very long running and the use of one precursor group may save computer costs and not impair the accuracy of the results significantly. Furthermore, in some codes, the elimation of five presursor groups makes additional memory available which may be used to give a net increase in the accuracy of the calculations, e.g., by allowing for an increase in mesh density. In order to use one delayed neutron precursor group it is necessary to derive a single decay constant, 6 lambda-, which, along with the total (or one group) delayed neutron fraction β = Σ/sub i = 1/β/sub i/, will adequately describe the transeint precursor behavior. The present summary explains how a recommendation for lambda- was derived

  9. General relation between the group delay and dwell time in multicomponent electron systems

    Science.gov (United States)

    Zhai, Feng; Lu, Junqiang

    2016-10-01

    For multicomponent electron scattering states, we derive a general relation between the Wigner group delay and the Bohmian dwell time. It is found that the definition of group delay should account for the phase of the spinor wave functions of propagating modes. The difference between the group delay and dwell time comes from both the interference delay and the decaying modes. For barrier tunneling of helical electrons on a surface of topological insulators, our calculations including the trigonal-warping term show that the decaying modes can contribute greatly to the group delay. The derived relation between the group delay and the dwell time is helpful to unify the two definitions of tunneling time in a quite general situation.

  10. Lie group classification of first-order delay ordinary differential equations

    Science.gov (United States)

    Dorodnitsyn, Vladimir A.; Kozlov, Roman; Meleshko, Sergey V.; Winternitz, Pavel

    2018-05-01

    A group classification of first-order delay ordinary differential equations (DODEs) accompanied by an equation for the delay parameter (delay relation) is presented. A subset of such systems (delay ordinary differential systems or DODSs), which consists of linear DODEs and solution-independent delay relations, have infinite-dimensional symmetry algebras—as do nonlinear ones that are linearizable by an invertible transformation of variables. Genuinely nonlinear DODSs have symmetry algebras of dimension n, . It is shown how exact analytical solutions of invariant DODSs can be obtained using symmetry reduction.

  11. Analog Group Delay Equalizers Design Based on Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    M. Laipert

    2006-04-01

    Full Text Available This paper deals with a design method of the analog all-pass filter designated for equalization of the group delay frequency response of the analog filter. This method is based on usage of evolutionary algorithm, the Differential Evolution algorithm in particular. We are able to design such equalizers to be obtained equal-ripple group delay frequency response in the pass-band of the low-pass filter. The procedure works automatically without an input estimation. The method is presented on solving practical examples.

  12. 36 CFR 13.905 - Group size.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Group size. 13.905 Section 13... § 13.905 Group size. (a) The following are prohibited: (1) Group sizes exceeding 12 individuals on the east side of the park outside the Frontcountry Developed Area as defined by this subpart. (2) Group...

  13. Group delay functions and its applications in speech technology

    Indian Academy of Sciences (India)

    (iii) High resolution property: The (anti) resonance peaks (due to complex ... Resolving power of the group delay spectrum: z-plane (a, d, g), magnitude ...... speech signal into syllable-like units, without the knowledge of phonetic transcription.

  14. Discrete hierarchical organization of social group sizes.

    Science.gov (United States)

    Zhou, W-X; Sornette, D; Hill, R A; Dunbar, R I M

    2005-02-22

    The 'social brain hypothesis' for the evolution of large brains in primates has led to evidence for the coevolution of neocortical size and social group sizes, suggesting that there is a cognitive constraint on group size that depends, in some way, on the volume of neural material available for processing and synthesizing information on social relationships. More recently, work on both human and non-human primates has suggested that social groups are often hierarchically structured. We combine data on human grouping patterns in a comprehensive and systematic study. Using fractal analysis, we identify, with high statistical confidence, a discrete hierarchy of group sizes with a preferred scaling ratio close to three: rather than a single or a continuous spectrum of group sizes, humans spontaneously form groups of preferred sizes organized in a geometrical series approximating 3-5, 9-15, 30-45, etc. Such discrete scale invariance could be related to that identified in signatures of herding behaviour in financial markets and might reflect a hierarchical processing of social nearness by human brains.

  15. Significance of Joint Features Derived from the Modified Group Delay Function in Speech Processing

    Directory of Open Access Journals (Sweden)

    Murthy Hema A

    2007-01-01

    Full Text Available This paper investigates the significance of combining cepstral features derived from the modified group delay function and from the short-time spectral magnitude like the MFCC. The conventional group delay function fails to capture the resonant structure and the dynamic range of the speech spectrum primarily due to pitch periodicity effects. The group delay function is modified to suppress these spikes and to restore the dynamic range of the speech spectrum. Cepstral features are derived from the modified group delay function, which are called the modified group delay feature (MODGDF. The complementarity and robustness of the MODGDF when compared to the MFCC are also analyzed using spectral reconstruction techniques. Combination of several spectral magnitude-based features and the MODGDF using feature fusion and likelihood combination is described. These features are then used for three speech processing tasks, namely, syllable, speaker, and language recognition. Results indicate that combining MODGDF with MFCC at the feature level gives significant improvements for speech recognition tasks in noise. Combining the MODGDF and the spectral magnitude-based features gives a significant increase in recognition performance of 11% at best, while combining any two features derived from the spectral magnitude does not give any significant improvement.

  16. Bearing fault detection utilizing group delay and the Hilbert-Huang transform

    International Nuclear Information System (INIS)

    Jin, Shuai; Lee, Sang-Kwon

    2017-01-01

    Vibration signals measured from a mechanical system are useful to detect system faults. Signal processing has been used to extract fault information in bearing systems. However, a wide vibration signal frequency band often affects the ability to obtain the effective fault features. In addition, a few oscillation components are not useful at the entire frequency band in a vibration signal. By contrast, useful fatigue information can be embedded in the noise oscillation components. Thus, a method to estimate which frequency band contains fault information utilizing group delay was proposed in this paper. Group delay as a measure of phase distortion can indicate the phase structure relationship in the frequency domain between original (with noise) and denoising signals. We used the empirical mode decomposition of a Hilbert-Huang transform to sift the useful intrinsic mode functions based on the results of group delay after determining the valuable frequency band. Finally, envelope analysis and the energy distribution after the Hilbert transform were used to complete the fault diagnosis. The practical bearing fault data, which were divided into inner and outer race faults, were used to verify the efficiency and quality of the proposed method

  17. Bearing fault detection utilizing group delay and the Hilbert-Huang transform

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shuai; Lee, Sang-Kwon [Inha University, Incheon (Korea, Republic of)

    2017-03-15

    Vibration signals measured from a mechanical system are useful to detect system faults. Signal processing has been used to extract fault information in bearing systems. However, a wide vibration signal frequency band often affects the ability to obtain the effective fault features. In addition, a few oscillation components are not useful at the entire frequency band in a vibration signal. By contrast, useful fatigue information can be embedded in the noise oscillation components. Thus, a method to estimate which frequency band contains fault information utilizing group delay was proposed in this paper. Group delay as a measure of phase distortion can indicate the phase structure relationship in the frequency domain between original (with noise) and denoising signals. We used the empirical mode decomposition of a Hilbert-Huang transform to sift the useful intrinsic mode functions based on the results of group delay after determining the valuable frequency band. Finally, envelope analysis and the energy distribution after the Hilbert transform were used to complete the fault diagnosis. The practical bearing fault data, which were divided into inner and outer race faults, were used to verify the efficiency and quality of the proposed method.

  18. Whistler-mode signals: Group delay by cross correlation

    International Nuclear Information System (INIS)

    Thomson, N.R.

    1975-01-01

    Group travel times of 18.6 kHz whistler-mode signals from NLK, Seattle, to Wellington, New Zealand, are now being measured using the normal FSK transmissions. This is done using a mini-computer programmed to perform real-time cross correlations between two receivers: one receiver gets its signal from a whip aerial on which the ground wave (subionospheric mode) dominates, while the other gets its signal from a loop oriented for minimum ground wave. Group travel time can thus be measured continuously while there are whistler-mode signals present. Delays of 0.2--0.8 seconds have been found

  19. Hyperactivity and frustration: the influence of control over and size of rewards in delaying gratification.

    Science.gov (United States)

    Rapport, M D; Tucker, S B; DuPaul, G J; Merlo, M; Stoner, G

    1986-06-01

    This study examined the differential effects of frustration on normal children and those diagnosed as having Attention Deficit Disorder with Hyperactivity. Each group consisted of 16 boys between the ages of 6 and 8 years who were prematched for age, grade, and classroom placement. All children completed a series of arithmetic problems in order to earn toy rewards. Using a variant of Mischel's (1974) delay-of-gratification paradigm, children were presented with two choice-of-delay conditions in a randomly assigned, counterbalanced sequence: a free-choice conflict situation involving a long-passive or short-active reward delay, and a short-active delay. Results showed that a significantly greater proportion of hyperactive children chose to complete problems for an immediate reward compared to their normal control counterparts (p less than .01). Group differences were no longer apparent in the short-active delay trial. The results are discussed in terms of frustration tolerance and contributing factors such as cognitive-attentional style. Implications for treatment and future directions are delineated.

  20. A polarization independent electromagnetically induced transparency-like metamaterial with large group delay and delay-bandwidth product

    Science.gov (United States)

    Bagci, Fulya; Akaoglu, Baris

    2018-05-01

    In this study, a classical analogue of electromagnetically induced transparency (EIT) that is completely independent of the polarization direction of the incident waves is numerically and experimentally demonstrated. The unit cell of the employed planar symmetric metamaterial structure consists of one square ring resonator and four split ring resonators (SRRs). Two different designs are implemented in order to achieve a narrow-band and wide-band EIT-like response. In the unit cell design, a square ring resonator is shown to serve as a bright resonator, whereas the SRRs behave as a quasi-dark resonator, for the narrow-band (0.55 GHz full-width at half-maximum bandwidth around 5 GHz) and wide-band (1.35 GHz full-width at half-maximum bandwidth around 5.7 GHz) EIT-like metamaterials. The observed EIT-like transmission phenomenon is theoretically explained by a coupled-oscillator model. Within the transmission window, steep changes of the phase result in high group delays and the delay-bandwidth products reach 0.45 for the wide-band EIT-like metamaterial. Furthermore, it has been demonstrated that the bandwidth and group delay of the EIT-like band can be controlled by changing the incidence angle of electromagnetic waves. These features enable the proposed metamaterials to achieve potential applications in filtering, switching, data storing, and sensing.

  1. Effects of Group Size on Students Mathematics Achievement in Small Group Settings

    Science.gov (United States)

    Enu, Justice; Danso, Paul Amoah; Awortwe, Peter K.

    2015-01-01

    An ideal group size is hard to obtain in small group settings; hence there are groups with more members than others. The purpose of the study was to find out whether group size has any effects on students' mathematics achievement in small group settings. Two third year classes of the 2011/2012 academic year were selected from two schools in the…

  2. The group delay and suppression pattern of the cochlear microphonic potential recorded at the round window.

    Directory of Open Access Journals (Sweden)

    Wenxuan He

    Full Text Available BACKGROUND: It is commonly assumed that the cochlear microphonic potential (CM recorded from the round window (RW is generated at the cochlear base. Based on this assumption, the low-frequency RW CM has been measured for evaluating the integrity of mechanoelectrical transduction of outer hair cells at the cochlear base and for studying sound propagation inside the cochlea. However, the group delay and the origin of the low-frequency RW CM have not been demonstrated experimentally. METHODOLOGY/PRINCIPAL FINDINGS: This study quantified the intra-cochlear group delay of the RW CM by measuring RW CM and vibrations at the stapes and basilar membrane in gerbils. At low sound levels, the RW CM showed a significant group delay and a nonlinear growth at frequencies below 2 kHz. However, at high sound levels or at frequencies above 2 kHz, the RW CM magnitude increased proportionally with sound pressure, and the CM phase in respect to the stapes showed no significant group delay. After the local application of tetrodotoxin the RW CM below 2 kHz became linear and showed a negligible group delay. In contrast to RW CM phase, the BM vibration measured at location ∼2.5 mm from the base showed high sensitivity, sharp tuning, and nonlinearity with a frequency-dependent group delay. At low or intermediate sound levels, low-frequency RW CMs were suppressed by an additional tone near the probe-tone frequency while, at high sound levels, they were partially suppressed only at high frequencies. CONCLUSIONS/SIGNIFICANCE: We conclude that the group delay of the RW CM provides no temporal information on the wave propagation inside the cochlea, and that significant group delay of low-frequency CMs results from the auditory nerve neurophonic potential. Suppression data demonstrate that the generation site of the low-frequency RW CM shifts from apex to base as the probe-tone level increases.

  3. Measuring and modeling the interaction among reward size, delay to reward, and satiation level on motivation in monkeys.

    Science.gov (United States)

    Minamimoto, Takafumi; La Camera, Giancarlo; Richmond, Barry J

    2009-01-01

    Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e.g., the identity, amount, and timing of a rewarding outcome) and internal factors (e.g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations that are similar to those found in free operant and choice tasks. The fraction of correct trials also decreased progressively as a function of the satiation level. Similar (albeit noiser) relations were obtained for reaction times. The combined effect of reward size, delay-to-reward, and satiation level on the proportion of correct trials is well described as a multiplication of the effects of the single factors when each factor is examined alone. These results provide a quantitative account of the interaction of external and internal factors on instrumental behavior, and allow us to extend the concept of subjective value of a rewarding outcome, usually confined to external factors, to account also for slow changes in the internal drive of the subject.

  4. Tunability of the FBG group delay through acousto-optic modulation

    Science.gov (United States)

    Marques, Carlos A. F.; Oliveira, Roberson A.; Pohl, Alexandre A. P.; Nogueira, Rogério N.

    2013-03-01

    A new method for fine control of the group delay of a fiber Bragg grating (FBG) is presented. It is based on an acoustic wave applied to the fiber. The standing acoustic wave imposes a periodic chirp to the uniform FBG. Tunability is obtained through adjustment of the intensity and/or frequency of the acoustic wave. A fast switching time of ∼17 μs was achieved. The experimental results were verified by theoretical simulation showing a good agreement between them. It can be used for different applications such as tunable narrow dispersion compensator for independent coarse wavelength division multiplexing (CWDM) channels or optical delay lines.

  5. Group size and social conflict in complex societies.

    Science.gov (United States)

    Shen, Sheng-Feng; Akçay, Erol; Rubenstein, Dustin R

    2014-02-01

    Conflicts of interest over resources or reproduction among individuals in a social group have long been considered to result in automatic and universal costs to group living. However, exploring how social conflict varies with group size has produced mixed empirical results. Here we develop a model that generates alternative predictions for how social conflict should vary with group size depending on the type of benefits gained from being in a social group. We show that a positive relationship between social conflict and group size is favored when groups form primarily for the benefits of sociality but not when groups form mainly for accessing group-defended resources. Thus, increased social conflict in animal societies should not be viewed as an automatic cost of larger social groups. Instead, studying the relationship between social conflict and the types of grouping benefits will be crucial for understanding the evolution of complex societies.

  6. Fluctuating survival selection explains variation in avian group size.

    Science.gov (United States)

    Brown, Charles R; Brown, Mary Bomberger; Roche, Erin A; O'Brien, Valerie A; Page, Catherine E

    2016-05-03

    Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark-recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

  7. Group size, grooming and fission in primates: a modeling approach based on group structure.

    Science.gov (United States)

    Sueur, Cédric; Deneubourg, Jean-Louis; Petit, Odile; Couzin, Iain D

    2011-03-21

    In social animals, fission is a common mode of group proliferation and dispersion and may be affected by genetic or other social factors. Sociality implies preserving relationships between group members. An increase in group size and/or in competition for food within the group can result in decrease certain social interactions between members, and the group may split irreversibly as a consequence. One individual may try to maintain bonds with a maximum of group members in order to keep group cohesion, i.e. proximity and stable relationships. However, this strategy needs time and time is often limited. In addition, previous studies have shown that whatever the group size, an individual interacts only with certain grooming partners. There, we develop a computational model to assess how dynamics of group cohesion are related to group size and to the structure of grooming relationships. Groups' sizes after simulated fission are compared to observed sizes of 40 groups of primates. Results showed that the relationship between grooming time and group size is dependent on how each individual attributes grooming time to its social partners, i.e. grooming a few number of preferred partners or grooming equally or not all partners. The number of partners seemed to be more important for the group cohesion than the grooming time itself. This structural constraint has important consequences on group sociality, as it gives the possibility of competition for grooming partners, attraction for high-ranking individuals as found in primates' groups. It could, however, also have implications when considering the cognitive capacities of primates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Group heterogeneity increases the risks of large group size: a longitudinal study of productivity in research groups.

    Science.gov (United States)

    Cummings, Jonathon N; Kiesler, Sara; Bosagh Zadeh, Reza; Balakrishnan, Aruna D

    2013-06-01

    Heterogeneous groups are valuable, but differences among members can weaken group identification. Weak group identification may be especially problematic in larger groups, which, in contrast with smaller groups, require more attention to motivating members and coordinating their tasks. We hypothesized that as groups increase in size, productivity would decrease with greater heterogeneity. We studied the longitudinal productivity of 549 research groups varying in disciplinary heterogeneity, institutional heterogeneity, and size. We examined their publication and citation productivity before their projects started and 5 to 9 years later. Larger groups were more productive than smaller groups, but their marginal productivity declined as their heterogeneity increased, either because their members belonged to more disciplines or to more institutions. These results provide evidence that group heterogeneity moderates the effects of group size, and they suggest that desirable diversity in groups may be better leveraged in smaller, more cohesive units.

  9. Group-size effect on scanning behaviour of Maasai Ostrich Struthio ...

    African Journals Online (AJOL)

    Group-size effect on scanning behaviour of Maasai Ostrich Struthio camelus ... minute) among different group sizes in late 2006 in Serengeti National Park, ... be influenced by factors other than group size, such as body size and habitat type.

  10. Comparison of reactor RA-4 kinetics with simulations with Matlab-Simulink for one group and six groups of delayed neutrons

    International Nuclear Information System (INIS)

    Orso, J A

    2012-01-01

    The critical state of a nuclear reactor is an unstable equilibrium. The nuclear reactor can go from critical to subcritical state or can go from critical to hypercritical state. Although the evolution of the system in these cases is slow, it requires the intervention of an operator to correct deviations. For this reason an automatic control technique was designed, based on the kinetic point to a group of delayed neutrons, which corrects deviations automatically. In this paper we study the point kinetics models in a group and six groups of delayed neutrons for different values of reactivity using the simulations software MATLAB, Simulink. A comparison of two models with the reactor kinetic behavior is made (author)

  11. Integrable microwave filter based on a photonic crystal delay line.

    Science.gov (United States)

    Sancho, Juan; Bourderionnet, Jerome; Lloret, Juan; Combrié, Sylvain; Gasulla, Ivana; Xavier, Stephane; Sales, Salvador; Colman, Pierre; Lehoucq, Gaelle; Dolfi, Daniel; Capmany, José; De Rossi, Alfredo

    2012-01-01

    The availability of a tunable delay line with a chip-size footprint is a crucial step towards the full implementation of integrated microwave photonic signal processors. Achieving a large and tunable group delay on a millimetre-sized chip is not trivial. Slow light concepts are an appropriate solution, if propagation losses are kept acceptable. Here we use a low-loss 1.5 mm-long photonic crystal waveguide to demonstrate both notch and band-pass microwave filters that can be tuned over the 0-50-GHz spectral band. The waveguide is capable of generating a controllable delay with limited signal attenuation (total insertion loss below 10 dB when the delay is below 70 ps) and degradation. Owing to the very small footprint of the delay line, a fully integrated device is feasible, also featuring more complex and elaborate filter functions.

  12. 8-group relative delayed neutron yields for monoenergetic neutron induced fission of 239Pu

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Kazakov, L.E.; Isaev, S.G.; Korolev, G.G.; Roshchenko, V.A.; Tertychnyj, R.G

    2002-01-01

    The energy dependence of the relative yield of delayed neutrons in an 8-group model representation was obtained for monoenergetic neutron induced fission of 239 Pu. A comparison of this data with the available experimental data by other authors was made in terms of the mean half-life of the delayed neutron precursors. (author)

  13. Noise analysis of the measurement of group delay in Fourier white-light interferometric cross correlation

    International Nuclear Information System (INIS)

    Laude, Vincent

    2002-01-01

    The problem of noise analysis in measuring the group delay introduced by a dispersive optical element by use of white-light interferometric cross correlation is investigated. Two noise types, detection noise and position noise, are specifically analyzed. Detection noise is shown to be highly sensitive to the spectral content of the white-light source at the frequency considered and to the temporal acquisition window. Position noise, which arises from the finite accuracy of the measurement of the scanning mirror's position, can severely damage the estimation of the group delay. Such is shown to be the case for fast Fourier transform-based estimation algorithms. A new algorithm that is insensitive to scanning delay errors is proposed, and subfemtosecond accuracy is obtained without any postprocessing

  14. Finite groups with three conjugacy class sizes of some elements

    Indian Academy of Sciences (India)

    Conjugacy class sizes; p-nilpotent groups; finite groups. 1. Introduction. All groups ... group G has exactly two conjugacy class sizes of elements of prime power order. .... [5] Huppert B, Character Theory of Finite Groups, de Gruyter Exp. Math.

  15. Finding the Energy Efficient Curve: Gate Sizing for Minimum Power under Delay Constraints

    Directory of Open Access Journals (Sweden)

    Yoni Aizik

    2011-01-01

    Full Text Available A design scenario examined in this paper assumes that a circuit has been designed initially for high speed, and it is redesigned for low power by downsizing of the gates. In recent years, as power consumption has become a dominant issue, new optimizations of circuits are required for saving energy. This is done by trading off some speed in exchange for reduced power. For each feasible speed, an optimization problem is solved in this paper, finding new sizes for the gates such that the circuit satisfies the speed goal while dissipating minimal power. Energy/delay gain (EDG is defined as a metric to quantify the most efficient tradeoff. The EDG of the circuit is evaluated for a range of reduced circuit speeds, and the power-optimal gate sizes are compared with the initial sizes. Most of the energy savings occur at the final stages of the circuits, while the largest relative downsizing occurs in middle stages. Typical tapering factors for power efficient circuits are larger than those for speed-optimal circuits. Signal activity and signal probability affect the optimal gate sizes in the combined optimization of speed and power.

  16. Nonapeptides and the Evolution of Social Group Sizes in Birds

    Directory of Open Access Journals (Sweden)

    James L. Goodson

    2011-03-01

    Full Text Available Species-typical patterns of grouping have profound impacts on many aspects of physiology and behavior. However, prior to our recent studies in estrildid finches, neural mechanisms that titrate species-typical group size preferences, independent of other aspects of social organization (e.g., mating system and parental care, have been wholly unexplored, likely because species-typical group size is typically confounded with other aspects of behavior and biology. An additional complication is that components of social organization are evolutionarily labile and prone to repeated divergence and convergence. Hence, we cannot assume that convergence in social structure has been produced by convergent modifications to the same neural characters, and thus any comparative approach to grouping must include not only species that differ in their species-typical group sizes, but also species that exhibit convergent evolution in this aspect of social organization. Using five estrildid finch species that differ selectively in grouping (all biparental and monogamous we have demonstrated that neural motivational systems evolve in predictable ways in relation to species-typical group sizes, including convergence in two highly gregarious species and convergence in two relatively asocial, territorial species. These systems include nonapeptide (vasotocin and mesotocin circuits that encode the valence of social stimuli (positive-negative, titrate group-size preferences, and modulate anxiety-like behaviors. Nonapeptide systems exhibit functional and anatomical properties that are biased towards gregarious species, and experimental reductions of nonapeptide signaling by receptor antagonism and antisense oligonucleotides significantly decrease preferred group sizes in the gregarious zebra finch. Combined, these findings suggest that selection on species-typical group size may reliably target the same neural motivation systems when a given social structure evolves

  17. Activity of the Delayed Neutron Working Group of JNDC and the International Evaluation Cooperation - WPEC/SG6

    International Nuclear Information System (INIS)

    Yoshida, Tadashi

    1999-01-01

    The Delayed Neutron Working Group was established in April 1997 within the Nuclear Data Subcommittee of JNDC. It has two principal missions. One is to coordinate the Japanese activities toward the WPEC/Subgroup-6 efforts, and the other is to recommend the delayed neutron data for JENDL-3.3. The final report of Subgroup-6, which in one of the subgroups of the NEA International Evaluation Cooperation (WPEC) and is in charge of the delayed neutron data, is to be completed in 1999. Here in Japan, JENDL-3.3 is planned to be released in early 2000. Delayed Neutron Working Group is, then, going to finalize its activity by the end of the fiscal year 1999 after recommending appropriate sets of data as coherently as possible with the of Subgroup-6 efforts. (author)

  18. COSTANZA, 1-D 2 Group Space-Dependent Reactor Dynamics of Spatial Reactor with 1 Group Delayed Neutrons

    International Nuclear Information System (INIS)

    Agazzi, A.; Gavazzi, C.; Vincenti, E.; Monterosso, R.

    1964-01-01

    1 - Nature of physical problem solved: The programme studies the spatial dynamics of reactor TESI, in the two group and one space dimension approximation. Only one group of delayed neutrons is considered. The programme simulates the vertical movement of the control rods according to any given movement law. The programme calculates the evolution of the fluxes and temperature and precursor concentration in space and time during the power excursion. 2 - Restrictions on the complexity of the problem: The maximum number of lattice points is 100

  19. The universal library of fission products and delayed neutron group yields

    International Nuclear Information System (INIS)

    Koldobskiy, A.B.; Zhivun, V.M.

    1997-01-01

    A new fission product yield library based on the Semiempirical method for the estimation of their mass and charge distribution is described. Contrary to other compilations, this library can be used with all possible excitation energies of fissionable actinides. The library of delayed neutron group yields, based on the fission product yield compilation, is described as well. (author). 15 refs, 4 tabs

  20. Ultrasonic delay measurements for the determination of the size of quasi-natural defects

    International Nuclear Information System (INIS)

    Proegler, H.

    1978-01-01

    Criteria in the form of delay measurements and phase assessments on ultrasonic pulses were worked out for a series of the most different reflection positions of the artificial, quasi-natural and natural kind which in many cases enable an differentiation of defects and the determination of the defect size. Even though it was not possible to completely clarify all effects occuring, such as reflection positions with undefined pulse orientations, the results sofar are still a contribution to the improvement of the stating ability of ultrasonic testing. (orig./RW) [de

  1. An accurate solution of point reactor neutron kinetics equations of multi-group of delayed neutrons

    International Nuclear Information System (INIS)

    Yamoah, S.; Akaho, E.H.K.; Nyarko, B.J.B.

    2013-01-01

    Highlights: ► Analytical solution is proposed to solve the point reactor kinetics equations (PRKE). ► The method is based on formulating a coefficient matrix of the PRKE. ► The method was applied to solve the PRKE for six groups of delayed neutrons. ► Results shows good agreement with other traditional methods in literature. ► The method is accurate and efficient for solving the point reactor kinetics equations. - Abstract: The understanding of the time-dependent behaviour of the neutron population in a nuclear reactor in response to either a planned or unplanned change in the reactor conditions is of great importance to the safe and reliable operation of the reactor. In this study, an accurate analytical solution of point reactor kinetics equations with multi-group of delayed neutrons for specified reactivity changes is proposed to calculate the change in neutron density. The method is based on formulating a coefficient matrix of the homogenous differential equations of the point reactor kinetics equations and calculating the eigenvalues and the corresponding eigenvectors of the coefficient matrix. A small time interval is chosen within which reactivity relatively stays constant. The analytical method was applied to solve the point reactor kinetics equations with six-groups delayed neutrons for a representative thermal reactor. The problems of step, ramp and temperature feedback reactivities are computed and the results compared with other traditional methods. The comparison shows that the method presented in this study is accurate and efficient for solving the point reactor kinetics equations of multi-group of delayed neutrons

  2. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  3. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  4. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    International Nuclear Information System (INIS)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay

  5. Spectral characterization of differential group delay in uniform fiber Bragg gratings.

    Science.gov (United States)

    Bette, S; Caucheteur, C; Wuilpart, M; Mégret, P; Garcia-Olcina, R; Sales, S; Capmany, J

    2005-12-12

    In this paper, we completely study the wavelength dependency of differential group delay (DGD) in uniform fiber Bragg gratings (FBG) exhibiting birefringence. An analytical expression of DGD is established. We analyze the impact of grating parameters (physical length, index modulation and apodization profile) on the wavelength dependency of DGD. Experimental results complete the paper. A very good agreement between theory and experience is reported.

  6. Homotopy analysis solutions of point kinetics equations with one delayed precursor group

    International Nuclear Information System (INIS)

    Zhu Qian; Luo Lei; Chen Zhiyun; Li Haofeng

    2010-01-01

    Homotopy analysis method is proposed to obtain series solutions of nonlinear differential equations. Homotopy analysis method was applied for the point kinetics equations with one delayed precursor group. Analytic solutions were obtained using homotopy analysis method, and the algorithm was analysed. The results show that the algorithm computation time and precision agree with the engineering requirements. (authors)

  7. Delay-dependent exponential stability of cellular neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Zhang Qiang; Wei Xiaopeng; Xu Jin

    2005-01-01

    The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results

  8. Effect of Group Setting on Gross Motor Performance in Children 3-5 Years Old with Motor Delays.

    Science.gov (United States)

    Fay, Deanne; Wilkinson, Tawna; Wagoner, Michelle; Brooks, Danna; Quinn, Lauren; Turnell, Andrea

    2017-02-01

    The purpose of this study was to evaluate differences in gross motor performance of children 3-5 years of age with motor delays when assessed individually compared to assessment in a group setting among peers with typical development (TD). Twenty children with motor delays and 42 children with TD were recruited from a preschool program. A within-subject repeated measures design was used; each child with delay was tested both in an individual setting and in a group setting with two to four peers with TD. Testing sessions were completed 4-8 days apart. Ten different motor skills from the Peabody Developmental Motor Scales-2 were administered. Performance of each item was videotaped and scored by a blinded researcher. Overall gross motor performance was significantly different (p < .05) between the two settings, with 14 of 20 children demonstrating better performance in the group setting. In particular, children performed better on locomotion items (p < .05). The higher scores for locomotion in the group setting may be due to the influence of competition, motivation, or modeling. Assessing a child in a group setting is recommended as part of the evaluation process.

  9. New Beta-delayed Neutron Measurements in the Light-mass Fission Group

    Energy Technology Data Exchange (ETDEWEB)

    Agramunt, J. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); García, A.R. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Algora, A. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Äystö, J. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Caballero-Folch, R.; Calviño, F. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Cano-Ott, D. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Cortés, G. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Domingo-Pardo, C. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Eronen, T. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Gelletly, W. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Gómez-Hornillos, M.B. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); and others

    2014-06-15

    A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for {sup 91}Br, {sup 86}As, {sup 85}As, and {sup 85}Ge nuclei.

  10. 31 CFR 205.17 - Are funds transfers delayed by automated payment systems restrictions based on the size and...

    Science.gov (United States)

    2010-07-01

    ... automated payment systems restrictions based on the size and timing of the drawdown request subject to this... Treasury-State Agreement § 205.17 Are funds transfers delayed by automated payment systems restrictions... to payment processes that automatically reject drawdown requests that fall outside a pre-determined...

  11. Light-Triggered Control of Plasmonic Refraction and Group Delay by Photochromic Molecular Switches

    DEFF Research Database (Denmark)

    Großmann, Malte; Klick, Alwin; Lemke, Christoph

    2015-01-01

    An interface supporting plasmonic switching is prepared from a gold substrate coated with a polymerfilm doped with photochromic molecular switches. A reversible light-induced change in the surface plasmon polariton dispersion curve of the interface is experimentally demonstrated, evidencing...... complex functionalities based on surface plasmon refraction and group delay....

  12. The effect of group size on vigilance in Ruddy Turnstones

    NARCIS (Netherlands)

    Fuller, R.A.; Bearhop, S.; Metcalfe, N.B.; Piersma, T.

    2013-01-01

    Foraging birds can manage time spent vigilant for predators by forming groups of various sizes. However, group size alone will not always reliably determine the optimal level of vigilance. For example, variation in predation risk or food quality between patches may also be influential. In a field

  13. Chromosome sizes of phytoplasmas composing major phylogenetic groups and subgroups.

    Science.gov (United States)

    Marcone, C; Neimark, H; Ragozzino, A; Lauer, U; Seemüller, E

    1999-09-01

    ABSTRACT Chromosome sizes of 71 phytoplasmas belonging to 12 major phylogenetic groups including several of the aster yellows subgroups were estimated from electrophoretic mobilities of full-length chromosomes in pulsed-field gels. Considerable variation in genome size, from 660 to 1,130 kilobases (kb), was observed among aster yellows phytoplasmas. Chromosome size heterogeneity was also observed in the stolbur phytoplasma group (range 860 to 1,350 kb); in this group, isolate STOLF contains the largest chromosome found in a phytoplasma to date. A wide range of chromosome sizes, from 670 to 1,075 kb, was also identified in the X-disease group. The other phytoplasmas examined, which included members of the apple proliferation, Italian alfalfa witches' broom, faba bean phyllody, pigeon pea witches' broom, sugarcane white leaf, Bermuda grass white leaf, ash yellows, clover proliferation, and elm yellows groups, all have chromosomes smaller than 1 megabase, and the size ranges within each of these groups is narrower than in the aster yellows, stolbur, and X-disease groups. The smallest chromosome, approximately 530 kb, was found in two Bermuda grass white leaf phytoplasma isolates. This not only is the smallest mollicute chromosome found to date, but also is the smallest chromosome known for any cell. More than one large DNA band was observed in several phytoplasma preparations. Possible explanations for the occurrence of more than one band may be infection of the host plant by different phytoplasmas, the presence of more than one chromosome in the same organism, or the presence of large extrachromosomal DNA elements.

  14. 8-group relative delayed neutron yields for epithermal neutron induced fission of 235U and 239Pu

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Kazakov, L.E.; Isaev, S.G.; Korolev, G.G.; Roshchenko, V.A.; Tertychnyj, R.G

    2002-01-01

    An 8-group representation of relative delayed neutron yields was obtained for epithermal neutron induced fission of 235 U and 239 Pu. These data were compared with ENDF/B-VI data in terms of the average half- life of the delayed neutron precursors and on the basis of the dependence of reactivity on the asymptotic period. (author)

  15. Experimental demonstration of two methods for controlling the group delay in a system with photonic-crystal resonators coupled to a waveguide.

    Science.gov (United States)

    Huo, Yijie; Sandhu, Sunil; Pan, Jun; Stuhrmann, Norbert; Povinelli, Michelle L; Kahn, Joseph M; Harris, James S; Fejer, Martin M; Fan, Shanhui

    2011-04-15

    We measure the group delay in an on-chip photonic-crystal device with two resonators side coupled to a waveguide. We demonstrate that such a group delay can be controlled by tuning either the propagation phase of the waveguide or the frequency of the resonators.

  16. Transmission and group-delay characterization of coupled resonator optical waveguides apodized through the longitudinal offset technique.

    Science.gov (United States)

    Doménech, J D; Muñoz, P; Capmany, J

    2011-01-15

    In this Letter, the amplitude and group delay characteristics of coupled resonator optical waveguides apodized through the longitudinal offset technique are presented. The devices have been fabricated in silicon-on-insulator technology employing deep ultraviolet lithography. The structures analyzed consisted of three racetracks resonators uniform (nonapodized) and apodized with the aforementioned technique, showing a delay of 5 ± 3 ps and 4 ± 0.5 ps over 1.6 and 1.4 nm bandwidths, respectively.

  17. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    Science.gov (United States)

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside

  18. Utilizing joint routing and capacity assignment algorithms to achieve inter- and intra-group delay fairness in multi-rate multicast wireless sensor networks.

    Science.gov (United States)

    Lin, Frank Yeong-Sung; Hsiao, Chiu-Han; Lin, Leo Shih-Chang; Wen, Yean-Fu

    2013-03-14

    Recent advance in wireless sensor network (WSN) applications such as the Internet of Things (IoT) have attracted a lot of attention. Sensor nodes have to monitor and cooperatively pass their data, such as temperature, sound, pressure, etc. through the network under constrained physical or environmental conditions. The Quality of Service (QoS) is very sensitive to network delays. When resources are constrained and when the number of receivers increases rapidly, how the sensor network can provide good QoS (measured as end-to-end delay) becomes a very critical problem. In this paper; a solution to the wireless sensor network multicasting problem is proposed in which a mathematical model that provides services to accommodate delay fairness for each subscriber is constructed. Granting equal consideration to both network link capacity assignment and routing strategies for each multicast group guarantees the intra-group and inter-group delay fairness of end-to-end delay. Minimizing delay and achieving fairness is ultimately achieved through the Lagrangean Relaxation method and Subgradient Optimization Technique. Test results indicate that the new system runs with greater effectiveness and efficiency.

  19. Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Philippe Jacquet

    2007-01-01

    Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

  20. Lipid composition and lidocaine effect on immediate and delayed injection pain following propofol administration.

    Science.gov (United States)

    Zirak, Nahid; Bameshki, Alireza; Yazdani, Mohammadjavad; Gilani, Mehryar Taghavi

    2016-01-01

    Propofol has been used for the induction and maintenance of anesthesia. However, patients experience vascular pain during its injection. The objective of this study was to compare the effect of the lipid type used in propofol preparations and that of lidocaine on the immediate and delayed vascular pain induced by propofol administration. In this double-blinded clinical study, 150 patients at American Society of Anesthesiologists level I-II were randomly divided into three equally sized groups. A propofol with medium and long-chain triglycerides (propofol-MCT/LCT) was administered to the first group. The second group received propofol containing propofol-LCT, and the third group received propofol-LCT and pretreatment lidocaine 20 mg. The incidence and the intensity of immediate (during injection) and delayed injection pain (after 20 s) were evaluated on a verbal analog scale (1-10) until patients' unconsciousness. Sample size was calculated with SigmaPlot version 12.5 software. Data were analyzed with Statistical Package for the Social Sciences (SPSS) version 16, one-way analysis of variance, and post-hoc Tukey. P < 0.05 was considered statistically significant. The demographic parameters of the three groups were similar. The lidocaine group experienced the least immediate vascular pain. The intensity of pain was highest in the propofol-LCT group (P = 0.04). Additionally, the intensity of delayed pain was lowest in the propofol-MCT/LCT group (P = 0.01). The incidence of pain associated with the propofol administration was 26.5, 44, and 18%, respectively, in propofol-MCT/LCT, propofol-LCT, and lidocaine and propofol-LCT groups. The results indicate an effect of the lipid type on delayed pain reduction, especially propofol-MCT/LCT. On the other hand, the lidocaine decreases immediate propofol-LCT vascular pain.

  1. Correlation of the size of undescended testis with its location in various age groups

    Energy Technology Data Exchange (ETDEWEB)

    Taqvi, S R.H.; Akhtar, J; Batool, T; Farhat, M [National Inst. of child Health, Karachi (Pakistan). Dept. of Peadiatrics; Tabassum, R [National Inst. of Child Health, Karachi (Pakistan). Dept. of Radiology

    2006-09-15

    To assess the correlation of the size of undescended testis with its location in children of various age groups, per- operatively. Children presenting with undescended testis at surgical outpatient were recruited. Physical examination and relevant investigations (haemoglobin, ultrasound for location and size of testes) were performed. Patients were divided randomly into three age groups, group I (8 months - 2.5 years), group II (2.6 - 8 years), group III (8.1-13 years). At orchiopexy location and size of undescended testis were noted. Patients were further sub-divided into groups according to peroperative location of undescended testis, group A (intra-abdominal), group B (intra-canalicular), group C (distal to superficial inguinal ring - pubic). Where no testis was found, a separate group D was assigned. The size of undescended testis at different locations in various age groups was compared with reference to normal descended testicular size in the respective age group, for statistical significance. ANOVA test was used for intergroup comparison for the size of undescended testis and Student t- test was applied for comparison with reference to normal values of the size of testis. A total of 102 patients with undescended testis were included in the study. The total number of 107 testicular units were assessed. Group I had 28, group II, 41 and group III, 38 testes. There were 24 intra-abdominal, 68 intra-canalicular and 12 pubic in location. In 3 cases, no testis was found at exploration. We found no statistically significant difference amongst groups (p-value=0.090) between the size of the undescended testis at different peroperative locations. The size of undescended testis grew with the age as undescended testis of larger size were found in older age group as compared to younger age group. By applying Student t-test, we did not find statistically significant difference in relation to the size of undescended testis in various age groups in comparison to the

  2. Correlation of the size of undescended testis with its location in various age groups

    International Nuclear Information System (INIS)

    Taqvi, S.R.H.; Akhtar, J.; Batool, T.; Farhat, M.; Tabassum, R.

    2006-01-01

    To assess the correlation of the size of undescended testis with its location in children of various age groups, per- operatively. Children presenting with undescended testis at surgical outpatient were recruited. Physical examination and relevant investigations (haemoglobin, ultrasound for location and size of testes) were performed. Patients were divided randomly into three age groups, group I (8 months - 2.5 years), group II (2.6 - 8 years), group III (8.1-13 years). At orchiopexy location and size of undescended testis were noted. Patients were further sub-divided into groups according to peroperative location of undescended testis, group A (intra-abdominal), group B (intra-canalicular), group C (distal to superficial inguinal ring - pubic). Where no testis was found, a separate group D was assigned. The size of undescended testis at different locations in various age groups was compared with reference to normal descended testicular size in the respective age group, for statistical significance. ANOVA test was used for intergroup comparison for the size of undescended testis and Student t- test was applied for comparison with reference to normal values of the size of testis. A total of 102 patients with undescended testis were included in the study. The total number of 107 testicular units were assessed. Group I had 28, group II, 41 and group III, 38 testes. There were 24 intra-abdominal, 68 intra-canalicular and 12 pubic in location. In 3 cases, no testis was found at exploration. We found no statistically significant difference amongst groups (p-value=0.090) between the size of the undescended testis at different peroperative locations. The size of undescended testis grew with the age as undescended testis of larger size were found in older age group as compared to younger age group. By applying Student t-test, we did not find statistically significant difference in relation to the size of undescended testis in various age groups in comparison to the

  3. Utilizing Joint Routing and Capacity Assignment Algorithms to Achieve Inter- and Intra-Group Delay Fairness in Multi-Rate Multicast Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yean-Fu Wen

    2013-03-01

    Full Text Available Recent advance in wireless sensor network (WSN applications such as the Internet of Things (IoT have attracted a lot of attention. Sensor nodes have to monitor and cooperatively pass their data, such as temperature, sound, pressure, etc. through the network under constrained physical or environmental conditions. The Quality of Service (QoS is very sensitive to network delays. When resources are constrained and when the number of receivers increases rapidly, how the sensor network can provide good QoS (measured as end-to-end delay becomes a very critical problem. In this paper; a solution to the wireless sensor network multicasting problem is proposed in which a mathematical model that provides services to accommodate delay fairness for each subscriber is constructed. Granting equal consideration to both network link capacity assignment and routing strategies for each multicast group guarantees the intra-group and inter-group delay fairness of end-to-end delay. Minimizing delay and achieving fairness is ultimately achieved through the Lagrangean Relaxation method and Subgradient Optimization Technique. Test results indicate that the new system runs with greater effectiveness and efficiency.

  4. The effectiveness of multimedia visual perceptual training groups for the preschool children with developmental delay.

    Science.gov (United States)

    Chen, Yi-Nan; Lin, Chin-Kai; Wei, Ta-Sen; Liu, Chi-Hsin; Wuang, Yee-Pay

    2013-12-01

    This study compared the effectiveness of three approaches to improving visual perception among preschool children 4-6 years old with developmental delays: multimedia visual perceptual group training, multimedia visual perceptual individual training, and paper visual perceptual group training. A control group received no special training. This study employed a pretest-posttest control group of true experimental design. A total of 64 children 4-6 years old with developmental delays were randomized into four groups: (1) multimedia visual perceptual group training (15 subjects); (2) multimedia visual perceptual individual training group (15 subjects); paper visual perceptual group training (19 subjects); and (4) a control group (15 subjects) with no visual perceptual training. Forty minute training sessions were conducted once a week for 14 weeks. The Test of Visual Perception Skills, third edition, was used to evaluate the effectiveness of the intervention. Paired-samples t-test showed significant differences pre- and post-test among the three groups, but no significant difference was found between the pre-test and post-test scores among the control group. ANOVA results showed significant differences in improvement levels among the four study groups. Scheffe post hoc test results showed significant differences between: group 1 and group 2; group 1 and group 3; group 1 and the control group; and group 2 and the control group. No significant differences were reported between group 2 and group 3, and group 3 and the control group. The results showed all three therapeutic programs produced significant differences between pretest and posttest scores. The training effect on the multimedia visual perceptual group program and the individual program was greater than the developmental effect Both the multimedia visual perceptual group training program and the multimedia visual perceptual individual training program produced significant effects on visual perception. The

  5. Nonlinear effects of group size on the success of wolves hunting elk

    Science.gov (United States)

    MacNulty, Daniel R.; Smith, Douglas W.; Mech, L. David; Vucetich, John A.; Packer, Craig

    2012-01-01

    Despite the popular view that social predators live in groups because group hunting facilitates prey capture, the apparent tendency for hunting success to peak at small group sizes suggests that the formation of large groups is unrelated to prey capture. Few empirical studies, however, have tested for nonlinear relationships between hunting success and group size, and none have demonstrated why success trails off after peaking. Here, we use a unique dataset of observations of individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to show that the relationship between success and group size is indeed nonlinear and that individuals withholding effort (free riding) is why success does not increase across large group sizes. Beyond 4 wolves, hunting success leveled off, and individual performance (a measure of effort) decreased for reasons unrelated to interference from inept hunters, individual age, or size. But performance did drop faster among wolves with an incentive to hold back, i.e., nonbreeders with no dependent offspring, those performing dangerous predatory tasks, i.e., grabbing and restraining prey, and those in groups of proficient hunters. These results suggest that decreasing performance was free riding and that was why success leveled off in groups with >4 wolves that had superficially appeared to be cooperating. This is the first direct evidence that nonlinear trends in group hunting success reflect a switch from cooperation to free riding. It also highlights how hunting success per se is unlikely to promote formation and maintenance of large groups.

  6. Resolving Microzooplankton Functional Groups In A Size-Structured Planktonic Model

    Science.gov (United States)

    Taniguchi, D.; Dutkiewicz, S.; Follows, M. J.; Jahn, O.; Menden-Deuer, S.

    2016-02-01

    Microzooplankton are important marine grazers, often consuming a large fraction of primary productivity. They consist of a great diversity of organisms with different behaviors, characteristics, and rates. This functional diversity, and its consequences, are not currently reflected in large-scale ocean ecological simulations. How should these organisms be represented, and what are the implications for their biogeography? We develop a size-structured, trait-based model to characterize a diversity of microzooplankton functional groups. We compile and examine size-based laboratory data on the traits, revealing some patterns with size and functional group that we interpret with mechanistic theory. Fitting the model to the data provides parameterizations of key rates and properties, which we employ in a numerical ocean model. The diversity of grazing preference, rates, and trophic strategies enables the coexistence of different functional groups of micro-grazers under various environmental conditions, and the model produces testable predictions of the biogeography.

  7. Calculation of the mean differential group delay of periodically spun, randomly birefringent fibers

    Science.gov (United States)

    Galtarossa, Andrea; Griggio, Paola; Pizzinat, Anna; Palmieri, Luca

    2002-05-01

    Spinning is one of the most effective and well-known ways to reduce polarization mode dispersion of optical fibers. In spite of the popularity of spinning, a detailed theory of spin effects is still lacking. We report an analytical expression for the mean differential group delay of a randomly birefringent spun fiber. The result holds for any periodic spin function with a period shorter than the fiber's beat length.

  8. Classic conditioning in aged rabbits: delay, trace, and long-delay conditioning.

    Science.gov (United States)

    Solomon, P R; Groccia-Ellison, M E

    1996-06-01

    Young (0.5 years) and aged (2+, 3+, and 4+ years) rabbits underwent acquisition of the classically conditioned nictitating membrane response in a delay (500-ms conditioned stimulus [CS], 400-ms interstimulus interval [ISI]), long-delay (1,000-ms CS, 900-ms ISI), or trace (500-ms CS, 400-ms stimulus-free period) paradigm. Collapsing across age groups, there is a general tendency for animals to acquire trace conditioning more slowly than delay conditioning. Collapsing across conditioning paradigms, there is a general tendency for aged animals to acquire more slowly than younger animals. Of greater significance, however, are the age differences in the different conditioning paradigms. In the delay and long-delay paradigms, significant conditioning deficits first appeared in the 4(+)-year-old group. In the trace conditioning paradigm, significant conditioning deficits became apparent in the 2(+)-year-old animals.

  9. Equalization of FBG-induced group-delay ripples penalties using a coherent receiver and digital signal processing

    NARCIS (Netherlands)

    Veljanovski, V.; Al Fiad, M.S.A.S.; Borne, van den D.; Jansen, S.L.; Wuth, T.

    2009-01-01

    We show the mitigation of fiber Bragg gratings induced group delay ripple penalties through the use of coherent detection and electronic equalizer. For 111-Gb/s POLMUX-RZDQPSK only a negligible penalty is observed after 10 cascaded FBGs.

  10. Accounting for One-Group Clustering in Effect-Size Estimation

    Science.gov (United States)

    Citkowicz, Martyna; Hedges, Larry V.

    2013-01-01

    In some instances, intentionally or not, study designs are such that there is clustering in one group but not in the other. This paper describes methods for computing effect size estimates and their variances when there is clustering in only one group and the analysis has not taken that clustering into account. The authors provide the effect size…

  11. Simple Exact Algorithm for Transistor Sizing of Low-Power High-Speed Arithmetic Circuits

    Directory of Open Access Journals (Sweden)

    Tooraj Nikoubin

    2010-01-01

    Full Text Available A new transistor sizing algorithm, SEA (Simple Exact Algorithm, for optimizing low-power and high-speed arithmetic integrated circuits is proposed. In comparison with other transistor sizing algorithms, simplicity, accuracy, independency of order and initial sizing factors of transistors, and flexibility in choosing the optimization parameters such as power consumption, delay, Power-Delay Product (PDP, chip area or the combination of them are considered as the advantages of this new algorithm. More exhaustive rules of grouping transistors are the main trait of our algorithm. Hence, the SEA algorithm dominates some major transistor sizing metrics such as optimization rate, simulation speed, and reliability. According to approximate comparison of the SEA algorithm with MDE and ADC for a number of conventional full adder circuits, delay and PDP have been improved 55.01% and 57.92% on an average, respectively. By comparing the SEA and Chang's algorithm, 25.64% improvement in PDP and 33.16% improvement in delay have been achieved. All the simulations have been performed with 0.13 m technology based on the BSIM3v3 model using HSpice simulator software.

  12. VLF group delay of lightning-induced electron precipitation echoes from measurement of phase and amplitude perturbations at two frequencies

    International Nuclear Information System (INIS)

    Adams, C.D.D.; Dowden, R.L.

    1990-01-01

    Measurement of phase and amplitude perturbations (trimpis) of the NWC signal at Dunedin at both the NWC frequencies, 22,250 Hz and 22,350 Hz, enables measurement of the received phase of the echo signal (phasor difference of the perturbed and unperturbed signals) at each frequency and so the rate of decrease of phase with frequency. This, of course, is the group delay. The 100-Hz difference implies that measurement of echo group delays of up to 5 ms could be made without ambiguity, though other factors limit this to about 2.5 ms. Some 38 difference trimpis during May and June 1988 showed echo delays up to 2 ms corresponding to reflection from points displaced more than 1,000 km from the NWC-Dunedin great circle path. The echo amplitudes observed at such large displacements are much greater than expected from smooth circular depressions of the ionosphere modifying the waveguide phase velocity and so imply sharper discontinuities in the waveguide

  13. HAMLET treatment delays bladder cancer development.

    Science.gov (United States)

    Mossberg, Ann-Kristin; Hou, Yuchuan; Svensson, Majlis; Holmqvist, Bo; Svanborg, Catharina

    2010-04-01

    HAMLET is a protein-lipid complex that kills different types of cancer cells. Recently we observed a rapid reduction in human bladder cancer size after intravesical HAMLET treatment. In this study we evaluated the therapeutic effect of HAMLET in the mouse MB49 bladder carcinoma model. Bladder tumors were established by intravesical injection of MB49 cells into poly L-lysine treated bladders of C57BL/6 mice. Treatment groups received repeat intravesical HAMLET instillations and controls received alpha-lactalbumin or phosphate buffer. Effects of HAMLET on tumor size and putative apoptotic effects were analyzed in bladder tissue sections. Whole body imaging was used to study HAMLET distribution in tumor bearing mice compared to healthy bladder tissue. HAMLET caused a dose dependent decrease in MB49 cell viability in vitro. Five intravesical HAMLET instillations significantly decreased tumor size and delayed development in vivo compared to controls. TUNEL staining revealed selective apoptotic effects in tumor areas but not in adjacent healthy bladder tissue. On in vivo imaging Alexa-HAMLET was retained for more than 24 hours in the bladder of tumor bearing mice but not in tumor-free bladders or in tumor bearing mice that received Alexa-alpha-lactalbumin. Results show that HAMLET is active as a tumoricidal agent and suggest that topical HAMLET administration may delay bladder cancer development. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  14. Delays in Building Construction Projects in Ghana

    Directory of Open Access Journals (Sweden)

    Adwoa B Agyakwah-Baah

    2010-07-01

    Full Text Available This study investigates the causes of delay of building construction projects in Ghana to determine the most important according to the key project participants; clients, consultants, and contractors. Thirty-two possible causes of delay were identified from the literature and semi-structured interviews of 15 key players in the implementation process. These delay factors were further categorised into nine major groups. The list of delay causes was subjected to a questionnaire survey for the identification of the most important causes of delay. The field survey included 130 respondents made up of 39 contractors, 37 clients and 54 consultants. The relative importance of the individual causes and the groups were calculated and ranked by their relative importance index. The overall results of the study indicate that the respondents generally agree that financial group factors ranked highest among the major factors causing delay in construction projects in Ghana. The financial group factors were delay in honouring payment certificates, difficulty in accessing credit and fluctuation in prices. Materials group factors are second followed by scheduling and controlling factors.

  15. Oncoplastic breast surgery does not delay the onset of adjuvant chemotherapy

    DEFF Research Database (Denmark)

    Klit, Anders; Tvedskov, Tove Filtenborg; Kroman, Niels

    2017-01-01

    BACKGROUND: Only a few studies of limited size have examined whether oncoplastic breast surgery delays the onset of adjuvant chemotherapy as compared to conventional breast surgery. We investigated whether oncoplastic breast surgery causes a delay in the onset of adjuvant chemotherapy in comparison...... to lumpectomy and mastectomy. MATERIAL AND METHODS: The study is a population-based cohort study. Within the nationwide registry of the Danish Breast Cancer Group (DBCG), we identified 1798 patients who received adjuvant chemotherapy following mastectomy, lumpectomy or oncoplastic breast surgery for early...... and unilateral invasive breast cancer. Women treated with neoadjuvant chemotherapy were excluded. RESULTS: We found no significant difference between the three groups (mastectomy, lumpectomy, oncoplastic breast surgery) in the time from biopsy to surgery (mean time 17.9, 17.0 and 18.3 days, respectively...

  16. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups.

    Science.gov (United States)

    Hasija, Narender; Bala, Madhu; Goyal, Virender

    2014-05-01

    Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton's ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. To determine any difference in tooth size discrepancy in anterior as well as overall ratio in different malocclusions and comparison with Bolton's study. After measuring the teeth on all 100 patients, Bolton's analysis was performed. Results were compared with Bolton's means and standard deviations. The results were also subjected to statistical analysis. Results show that the mean and standard deviations of ideal occlusion cases are comparable with those Bolton but, when the mean and standard deviation of malocclusion groups are compared with those of Bolton, the values of standard deviation are higher, though the mean is comparable. How to cite this article: Hasija N, Bala M, Goyal V. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups. Int J Clin Pediatr Dent 2014;7(2):82-85.

  17. Liquidity Determinants of the Selected Banking Sectors and their Size Groups

    Directory of Open Access Journals (Sweden)

    Jana Laštůvková

    2016-01-01

    Full Text Available The article focuses on the factors affecting the liquidity of selected bank sectors, as well as their size groups, using panel regression analysis. For higher complexity of the results, multiple dependent variables are used: liquidity creation, outflow and net change. The values are calculated based on the specific method of liquidity risk measurement – gross liquidity flows. The results indicate both multiple effects of some factors on the given variables, as well as isolated influence of factors on a single liquidity form or size group. Thus, when looking for determinants using just one form of liquidity, such as creation, the results need not necessarily comprehensively show the influence of the given factors, and can lead to erroneous conclusions. The results also point to the differing behaviours of the size groups and their different sensitivity on the factors; smaller banks have shown higher sensitivity on macroeconomic variables. Higher flexibility in regulation could lead to higher optimization.

  18. The evolution of body size in extant groups of North American freshwater fishes: speciation, size distributions, and Cope's rule.

    Science.gov (United States)

    Knouft, Jason H; Page, Lawrence M

    2003-03-01

    Change in body size within an evolutionary lineage over time has been under investigation since the synthesis of Cope's rule, which suggested that there is a tendency for mammals to evolve larger body size. Data from the fossil record have subsequently been examined for several other taxonomic groups to determine whether they also displayed an evolutionary increase in body size. However, we are not aware of any species-level study that has investigated the evolution of body size within an extant continental group. Data acquired from the fossil record and data derived from the evolutionary relationships of extant species are not similar, with each set exhibiting both strengths and weaknesses related to inferring evolutionary patterns. Consequently, expectation that general trends exhibited in the fossil record will correspond to patterns in extant groups is not necessarily warranted. Using phylogenetic relationships of extant species, we show that five of nine families of North American freshwater fishes exhibit an evolutionary trend of decreasing body size. These trends result from the basal position of large species and the more derived position of small species within families. Such trends may be caused by the invasion of small streams and subsequent isolation and speciation. This pattern, potentially influenced by size-biased dispersal rates and the high percentage of small streams in North America, suggests a scenario that could result in the generation of the size-frequency distribution of North American freshwater fishes.

  19. Pengaruh Faktor Internal dan Eksternal Perusahaan Terhadap Audit Delay dan Timeliness

    Directory of Open Access Journals (Sweden)

    Sistya Rachmawati

    2008-01-01

    Full Text Available The objective of this research is to investigate the influence of the firm size, the profitability, the solvability, the public accountant size and the existence of internal auditor division toward the Audit Delay and Timeliness on manufacture companies that listed in Jakarta Stock Exchange.The Research sample was taken from Fifty-nine listed companies in Jakarta Stock Exchange. These samples were selected by using Purposive sampling method. Analysis hypothesis is using Multiple Regression, before hypothesis test, normality data test using P-Plot test.The result of Multiple Regression model shows that Audit Delay influenced by firm size and public accountant size, and Timeliness influenced by firm size and solvability. This result is recommended for auditor to increase effectiveness and efficiency of his audit performance and for all existing studies to contribute towards the current literature on Auditing. Abstract in Bahasa Indonesia: Penelitian ini bertujuan untuk mengukur pengaruh faktor internal yaitu: profitabilitas, solva¬bili¬tas, internal auditor dan size perusahaan dan faktor eksternal, yaitu ukuran KAP terhadap audit delay dan Timeliness pada perusahaan manufaktur yang terdaftar pada Jakarta Stock Exchange. Pemilihan sampel menggunakan metode Purposive Sampling. Dari hasil pengolahan Regresi Berganda pada Audit Delay diketahui bahwa koefisien determi¬nasi Adjusted R2 = 0,123. Artinya seluruh variabel independen (Profitabilitas, Solvabilitas, Internal Auditor, Size Perusahaan, dan KAP hanya mampu menjelaskan variasi dari variabel depen¬den (Audit Delay adalah sebesar 12,3%. Sedang¬kan pada Timeliness, seluruh variabel independen (Profitabilitas, Solvabilitas, Internal Auditor, Size Perusahaan, dan KAP dapat men¬jelaskan variasi pada variabel dependennya (Timeliness adalah sebesar 7,9%. Hasil dari penelitian ini dapat membantu profesi akuntan publik dalam upaya meningkatkan efisiensi dan efektivitas proses audit dengan

  20. Group size and group income as influences on marriage patterns in Hawaii.

    Science.gov (United States)

    Johnson, R C

    1984-01-01

    This paper analyzes the association of ethnic group size and median ethnic group income with the percentages of cross-ethnic marriages and combinations of marriages of each of the 5 major racial/ethnic groups in Hawaii. The data cover marriages that took place from 1975-1977 in Hawaii's 5 major ethnic groups: 1) Caucasian, 2) Chinese, 3) Filipino, 4) Japanese, and 5) Hawaiian or part-Hawaiian. The number of Caucasians marrying in Hawaii are severely inflated by military and tourist marriages. Chinese (highest median income) and Hawaiians or part-Hawaiians (lowest median income) show the highest percentages of outmarriage. The number of persons making up given groups appears to play a role; larger groups have lower outmarriage rates. Since 19 of 20 potential marriage partners a Chinese person meets are of another racial group, as compared to 2 of 3 for Caucasians or Japanese, it is hardly surprising that the Chinese outmarry more often than other groups. Data show a tendency to an East-West split; Chinese-Japanese marriages are overrepresented, and marriages of Japanese men to Caucasian women are underrepresented. However, marriages of Caucasian males to Chinese women are also overrepresented. Also, Puerto Ricans and Filipinos tend to be more representative of the West than Caucasians are. The authors conclude that cultural attributes likely to lead to a given level of income, rather than income per se, influence the probability of persons marrying a member of a given racial/ethnic group other than their own.

  1. Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

    Science.gov (United States)

    Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

    2013-09-01

    We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025). Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Evolution of students’ friendship networks: Examining the influence of group size

    Directory of Open Access Journals (Sweden)

    Valentina Sokolovska

    2017-01-01

    Full Text Available  The main aim of this study was to examine the effect of the network size on formation and evolution of students’ friendship relations. Data was collected from two groups of sociology freshmen: a group from the University of Belgrade, which represents a larger group, and a group from the University of Novi Sad, which represents a smaller group. The data was collected in three periods of one academic year. We analyzed the structural features of students’ networks and constructed a stochastic model of network evolution in order to explore how friendships form and change during one year. The results showed that structural features of the larger and the smaller group differ in each stage of friendship formation. At the beginning of group forming, small world structure was noticeable in the larger group, although full small world structure was not confirmed in both groups. Furthermore, transitivity of triads had effect on the evolution of the larger network, while balance or structural equivalence had effect on the evolution of the smaller network. Results of the structural analysis are in line with findings of the network evolution model and together they provide an insight into how friendship evolves in groups of different sizes.

  3. 基于MUSIC-Group Delay算法的相邻相干信号源定位%Closely spaced coherent-source localization based on MUSIC-group delay algorithm

    Institute of Scientific and Technical Information of China (English)

    郑家芝

    2016-01-01

    为了准确的进行相邻的相干信号源定位,提出了一种基于多重信号分类群延迟(MUSIC-group delay)的改进算法。首先,将空间平滑技术引入到波达方向(DoA)估计当中去除部分相干信号。由于在信号源相邻的情况下子空间算法的性能降低,就结合了 MUSIC-Group Delay算法来区分相邻的信号源,这种方法因为自身的加和性通过 MUSIC 相位谱来计算群延迟函数,从而能估计出相邻的信号源。理论分析和仿真结果表明提出的方法估计相邻的相干信号源比子空间算法更精确,分辨率更高。%In this paper,the closely spaced coherent-source localization is considered,and an improved method based on the group delay of Multiple Signal Classification (MUSIC)is presented.Firstly,we introduce the spatial smoothing technique into direction of arrival (DoA)estimation to get rid of the coherent part of signals.Due to the degraded per-formance of sub-space based methods on the condition of nearby sources,we then utilize the MUSIC-Group Delay algo-rithm to distinguish the closely spaced sources,which can resolve spatially close sources by the use of the group delay function computed from the MUSIC phase spectrum for efficient DoA estimation owing to its spatial additive property. Theoretical analysis and simulation results demonstrate that the proposed approach can estimate the DoA of the coherent close signal sources more precisely and have higher resolution compared with sub-space based methods.

  4. The role of micro size computing clusters for small physics groups

    International Nuclear Information System (INIS)

    Shevel, A Y

    2014-01-01

    A small physics group (3-15 persons) might use a number of computing facilities for the analysis/simulation, developing/testing, teaching. It is discussed different types of computing facilities: collaboration computing facilities, group local computing cluster (including colocation), cloud computing. The author discuss the growing variety of different computing options for small groups and does emphasize the role of the group owned computing cluster of micro size.

  5. Delay time and Hartman effect in strain engineered graphene

    International Nuclear Information System (INIS)

    Chen, Xi; Deng, Zhi-Yong; Ban, Yue

    2014-01-01

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect

  6. Analysis of stability for stochastic delay integro-differential equations.

    Science.gov (United States)

    Zhang, Yu; Li, Longsuo

    2018-01-01

    In this paper, we concern stability of numerical methods applied to stochastic delay integro-differential equations. For linear stochastic delay integro-differential equations, it is shown that the mean-square stability is derived by the split-step backward Euler method without any restriction on step-size, while the Euler-Maruyama method could reproduce the mean-square stability under a step-size constraint. We also confirm the mean-square stability of the split-step backward Euler method for nonlinear stochastic delay integro-differential equations. The numerical experiments further verify the theoretical results.

  7. Delay and death-thought accessibility: a meta-analysis.

    Science.gov (United States)

    Steinman, Christopher T; Updegraff, John A

    2015-12-01

    The dual-process component of Terror Management Theory (TMT) proposes that different types of threats lead to increases in death-thought accessibility (DTA) after different delay intervals. Experimental studies of terror management threats' effect on DTA were collected and coded for their use of explicitly death-related (vs. not explicitly death-related) threats, and for their use of delay and task-switching during the delay. Results reveal that studies using death-related threats achieved larger DTA effect-sizes when they included more task-switching or a longer delay between the threat and the DTA measurement. In contrast, studies using threats that were not explicitly death-related achieved smaller DTA effect-sizes when they included more task-switching between the threat and the DTA measurement. These findings provide partial support for the dual-process component's predictions regarding delay and DTA. Limitations and future directions are discussed. © 2015 by the Society for Personality and Social Psychology, Inc.

  8. Couch potatoes do better: Delayed dispersal and territory size affect the duration of territory occupancy in a monogamous mammal.

    Science.gov (United States)

    Mayer, Martin; Zedrosser, Andreas; Rosell, Frank

    2017-06-01

    In territorial, socially monogamous species, the establishment and defense of a territory are an important strategy to maximize individual fitness, but the factors responsible for the duration of territory occupancy are rarely studied, especially in long-lived mammals. A long-term monitoring program in southeast Norway spanning over 18 years allowed us to follow the individual life histories of Eurasian beavers ( Castor fiber ) from adolescence in their natal family group to dispersal and territory establishment until the end of territory occupancy. We investigated whether territory size, resource availability, population density, and dispersal age could explain the duration of territory occupancy, which ranged from 1 to 11 years. The duration of territory occupancy was positively related to dispersal age, suggesting that individuals that delayed dispersal had a competitive advantage due to a larger body mass. This is in support with the maturation hypothesis, which states that an animal should await its physical and behavioral maturation before the acquisition of a territory. Further, we found that individuals that established in medium-sized territories occupied them longer as compared to individuals in small or large territories. This suggests that large territories are more costly to defend due to an increased patrolling effort, and small territories might not have sufficient resources. The lifetime reproductive success ranged from zero to six kits and generally increased with an increasing duration of territory occupancy. Our findings show the importance of holding a territory and demonstrate that dispersal decisions and territory selection have important consequences for the fitness of an individual.

  9. Tunable delay time and Hartman effect in graphene magnetic barriers

    International Nuclear Information System (INIS)

    Ban, Yue; Wang, Lin-Jun; Chen, Xi

    2015-01-01

    Tunable group delay and Hartman effect have been investigated for massless Dirac electrons in graphene magnetic barriers. In the presence of magnetic field, dwell time is found to be equal to net group delay plus the group delay contributing from the lateral shifts. The group delay times are discussed in both cases of normal and oblique incidence, to clarify the nature of Hartman effect. In addition, the group delay in transmission can be modulated from subluminality to superluminality by adjusting the magnetic field, which may also lead to potential applications in graphene-based microelectronics

  10. Comparison of feeding behavior between two different-sized groups of Japanese macaques (Macaca fuscata yakui).

    Science.gov (United States)

    Kurihara, Yosuke; Hanya, Goro

    2015-05-13

    Group-living animals face intragroup scramble and intergroup contest competitions. Many studies have shown that larger groups bear the costs of intragroup scramble competition, which negatively affects the reproductive success of females. Unlike most primate species, Japanese macaques in the Yakushima coastal forest show increased reproductive success with group size. However, it remains unclear how group size affects the behavior of macaques. The present study examined the effects of group size on the feeding behavior of Japanese macaques in the Yakushima coastal forest. We investigated 9-13 adult females from two different-sized groups via focal animal sampling during October 2012-August 2013. We compared the feeding behavior, including patch use, between the two groups. The larger group had a larger home range and spent more time feeding, especially on mature leaves. This suggests that intragroup feeding competition should be more intense in the larger group than in the smaller group. The feeding of mature leaves might enable the larger group to increase the number of co-feeding individuals. Contrary to the predictions that the larger group travels longer distances and spends more time moving, the smaller group traveled longer distances, and spent more time moving, although the number of visited patches did not differ between the two groups. The immediate consequences of the loss of inter-group encounters could accumulate as daily travel costs, considering that group size is associated with inter-group dominance and that intergroup aggressive encounters occur frequently in the Yakushima coastal forest. This suggests that the smaller group has increased travel costs as a result of intergroup contest competition, which leads to decline in reproductive success. Am. J. Primatol. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  11. Intergroup Discrimination in Positive and Negative Outcome Allocations: Impact of Stimulus Valence, Relative Group Status, and Relative Group Size.

    Science.gov (United States)

    Otten, Sabine; And Others

    1996-01-01

    Three studies investigated the determination of social discrimination by the valence of stimuli that are allocated between groups. The studies were based on either the minimal group paradigm or a more reality-based laboratory intergroup setting, with stimulus valence, group status, and group size as factors and with pull scores on Tajfel matrices…

  12. Analytical expressions for group delay in the far field from an optical fiber having an arbitrary index profile

    DEFF Research Database (Denmark)

    Danielsen, Per Lander

    1981-01-01

    A general and efficient model for optical fibers with a few modes and arbitrary index profiles is established. The model yields a solution of the vectorial wave equation and analytical expressions for the group delay and the far field. Convergence tests have shown that the dispersion can...

  13. Electrically tunable photonic true-time-delay line.

    Science.gov (United States)

    Barmenkov, Yuri O; Cruz, José Luis; Díez, Antonio; Andrés, Miguel V

    2010-08-16

    We present a new application of the acousto-optic superlattice modulation of a fiber Bragg grating based on the dynamic phase and group delay properties of this fiber-optic component. We demonstrate a tunable photonic true-time-delay line based on the group delay change of the light reflected from the grating sidebands. The delay is electrically tuned by adjusting the voltage applied to a piezoelectric transducer that generates the acoustic wave propagating along the grating. In our experiments, a true-time delay of 400 ps is continuously adjusted (300 ps within the 3 dB amplitude range of the first sideband), using a 12 cm long uniform grating.

  14. Predation, scramble competition, and the vigilance group size effect in dark-eyed juncos (Junco hyemalis)

    Science.gov (United States)

    Steven L. Lima; Patrick A. Zollner; Peter A. Bednekoff

    1999-01-01

    In socially feeding birds and mammals, as group size increases, individuals devote less time to scanning their environment and more time to feeding. This vigilance "group size effect" has long been attributed to the anti-predatory benefits of group living, but many investigators have suggested that this effect may be driven by scramble competition for limited...

  15. Unconditionally stable difference methods for delay partial differential equations

    OpenAIRE

    Huang, Chengming; Vandewalle, Stefan

    2012-01-01

    This paper is concerned with the numerical solution of parabolic partial differential equations with time-delay. We focus in particular on the delay dependent stability analysis of difference methods that use a non-constrained mesh, i.e., the time step-size is not required to be a submultiple of the delay. We prove that the fully discrete system unconditionally preserves the delay dependent asymptotic stability of the linear test problem under consideration, when the following discretizati...

  16. Synchronization of Markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time-varying delays

    International Nuclear Information System (INIS)

    Li Hongjie; Yue Dong

    2010-01-01

    The paper investigates the synchronization stability problem for a class of complex dynamical networks with Markovian jumping parameters and mixed time delays. The complex networks consist of m modes and the networks switch from one mode to another according to a Markovian chain with known transition probability. The mixed time delays are composed of discrete and distributed delays, the discrete time delay is assumed to be random and its probability distribution is known a priori. In terms of the probability distribution of the delays, the new type of system model with probability-distribution-dependent parameter matrices is proposed. Based on the stochastic analysis techniques and the properties of the Kronecker product, delay-dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the LMI toolbox in MATLAB, the solvability of derived conditions depends on not only the size of the delay, but also the probability of the delay-taking values in some intervals. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.

  17. Infinite dwell time and group delay in resonant electron tunneling through double complex potential barrier

    Science.gov (United States)

    Opacak, Nikola; Milanović, Vitomir; Radovanović, Jelena

    2017-12-01

    Tunneling times in complex potentials are investigated. Analytical expressions for dwell time, self-interference time and group delay are obtained for the case of complex double delta potentials. It is shown that we can always find a set of parameters of the potential so that the tunneling times achieve very large values and even approach infinity for the case of resonance. The phenomenon of infinite tunneling times occurs for only one particular positive value of the imaginary part of the potential, if all other parameters are given.

  18. Habitat, density and group size of primates in a Brazilian tropical forest.

    Science.gov (United States)

    Pinto, L P; Costa, C M; Strier, K B; da Fonseca, G A

    1993-01-01

    Habitats, population densities and group sizes of 5 primate species (Callithrix flaviceps, Callicebus personatus personatus, Cebus apella nigritus, Alouatta fusca clamitans, and Brachyteles arachnoides) were estimated, using the method of repeated transect sampling, in an area of montane pluvial forest in eastern Brazil (Atlantic forest). A. fusca and C. apella had the highest densities in terms of groups and individuals per square kilometer, respectively, while B. arachnoides was least abundant. The highest primate densities were observed in areas of secondary vegetation. Both group sizes and population densities for the 5 species were generally lower at the Reserva Biologica Augusto Ruschi than those reported in other areas of Atlantic forest. Hunting pressure and the different carrying capacity of the habitat are suggested as possible causes for the low number of sightings registered for these species.

  19. The Influence of Social Comparison and Peer Group Size on Risky Decision-Making.

    Science.gov (United States)

    Wang, Dawei; Zhu, Liping; Maguire, Phil; Liu, Yixin; Pang, Kaiyuan; Li, Zhenying; Hu, Yixin

    2016-01-01

    This study explores the influence of different social reference points and different comparison group sizes on risky decision-making. Participants were presented with a scenario describing an exam, and presented with the opportunity of making a risky decision in the context of different information provided about the performance of their peers. We found that behavior was influenced, not only by comparison with peers, but also by the size of the comparison group. Specifically, the larger the reference group, the more polarized the behavior it prompted. In situations describing social loss, participants were led to make riskier decisions after comparing themselves against larger groups, while in situations describing social gain, they become more risk averse. These results indicate that decision making is influenced both by social comparison and the number of people making up the social reference group.

  20. Analyzing delay causes in Egyptian construction projects

    Directory of Open Access Journals (Sweden)

    Mohamed M. Marzouk

    2014-01-01

    Full Text Available Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor’s organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  1. Functional groups and reactivity of size-fractionated Aldrich humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Tadao, E-mail: tanaka.tadao26@jaea.go.jp [Nuclear Safety Research Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Naka, Ibaraki, 319-1195 (Japan)

    2012-03-20

    The complexation affinity of the Aldrich Chemicals humic acid with {sup 60}Co was examined with respect to molecular size of humic acid. Correlations between the affinity and the structures of humic acid were studied. At low humic acid concentration range, {sup 60}Co was interacted with the humic acid of size fraction over 100k Da (HA(100<)). With increasing humic acid concentration, the {sup 60}Co was preferentially interacted with the 30k-100k Da of humic acid (HA(30-100)). Fractionated HA(100<) and HA(30-100) were characterized from their FTIR (Fourier Transform Infra-Red), {sup 13}C NMR spectral analyses and acid-base titration curves. The HA(10<) having aliphatic branched structure, smaller amount of COOH group and large proton exchangeable capacity, seem to show low covalent bonding nature and high ion exchangeability in the complexation. In addition, steric hindrance may affect on the complexation, by winding up like random coils from the branched structure. The HA(30-100) is dominated with the aromatic COOH group and OH group and it may preferentially coordinate to {sup 60}Co by covalent binding. These presumptions were supported by XPS analysis, in which the biding energy of cobalt-humates was discussed.

  2. Probing the limits of delay intolerance: preliminary young adult data from the Delay Frustration Task (DeFT).

    Science.gov (United States)

    Bitsakou, Paraskevi; Antrop, Inge; Wiersema, Jan Roelf; Sonuga-Barke, Edmund J S

    2006-02-15

    Delay intolerance/aversion is one amongst a number of candidate neuropsychological endophenotypes for ADHD. Pilot data suggest that, because of potential ceiling effects, simple choice measures of delay tolerance used for children are probably not appropriate for adolescents and adults. The Delay Frustration Task (DeFT) is a new measure of delay intolerance, designed to be used in a similar form with adolescents and adults as well as children. In it delay frustration is indexed as the number and duration of responses made on a response key during a series of unpredictable and unsignalled delay periods, which interrupt the completion of a simple computer-based tests. The aim of this study was to provide preliminary data on the applicability of the task in a sample of young adults. The DeFT was administered to 49 male and female undergraduate students selected from a normal population-base. Their mean age was 23.14 (S.D.=1.54). Three measures of delay frustration were recorded across time intervals during the response window; the number of responses, their duration and their combined product (total time button was pressed) was calculated for each second interval bin during the post-response delay period. The AARS and HADS were used as screening questionnaires for ADHD and anxiety behaviour, respectively. The results indicated that young adults with high-ADHD symptoms scores pressed the button more than those with low ADHD scores during the post-response delay condition. While both groups increased responding across time within intervals this was significantly more marked in the high-ADHD symptom group. These effects became more pronounced when anxiety was controlled. Young adults with high-ADHD symptoms appear to be more sensitive to the imposition of unscheduled and unsignalled delay during a simple maths test. DeFT may provide a useful index of delay tolerance in young adults with ADHD. Future research needs to examine DeFT performance in different age groups and

  3. Precise delay measurement through combinatorial logic

    Science.gov (United States)

    Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

    2010-01-01

    A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

  4. Comparing radio-tracking and visual detection methods to quantify group size measures

    Directory of Open Access Journals (Sweden)

    Reiczigel Jenő

    2015-12-01

    Full Text Available 1. Average values of animal group sizes are prone to be overestimated in traditional field studies because small groups and singletons are easier to overlook than large ones. This kind of bias also applies for the method of locating groups by tracking previously radio-collared individuals in the wild. If the researcher randomly chooses a collared animal to locate a group to visit, a large group has higher probability to be selected than a small one, simply because it has more members.

  5. A scheme to expand the delay-bandwidth product in the resonator-based delay lines by optical OFDM technique

    DEFF Research Database (Denmark)

    Zhu, Jiangbo; Tao, Li; Zhang, Ziran

    2013-01-01

    We propose a novel scheme to expand the inherent limit in the product of the optical delay and the transmission bandwidth in resonator-based delay lines, with the optical orthogonal frequency division multiplexing (OOFDM) technique. The optical group delay properties of a single ring resonator we...

  6. Within-Group Effect-Size Benchmarks for Trauma-Focused Cognitive Behavioral Therapy with Children and Adolescents

    Science.gov (United States)

    Rubin, Allen; Washburn, Micki; Schieszler, Christine

    2017-01-01

    Purpose: This article provides benchmark data on within-group effect sizes from published randomized clinical trials (RCTs) supporting the efficacy of trauma-focused cognitive behavioral therapy (TF-CBT) for traumatized children. Methods: Within-group effect-size benchmarks for symptoms of trauma, anxiety, and depression were calculated via the…

  7. Analytical expressions for group delay in the far field from an optical fiber having an arbitrary index profile

    OpenAIRE

    Danielsen, Per Lander

    1981-01-01

    A general and efficient model for optical fibers with a few modes and arbitrary index profiles is established. The model yields a solution of the vectorial wave equation and analytical expressions for the group delay and the far field. Convergence tests have shown that the dispersion can be calculated with an accuracy better than 0.2 ps/(km . nm).

  8. Tunable dual-wavelength filter and its group delay dispersion in domain-engineered lithium niobate

    Directory of Open Access Journals (Sweden)

    Guang-hao Shao

    2016-12-01

    Full Text Available A tunable dual-wavelength filter is experimentally demonstrated in domain-engineered lithium niobate. Application of an electric field on the y-surfaces of the sample results in the optical axes rotating clockwise and anticlockwise, which makes selective polarization rotation. The quasi phase-matching wavelengths could be adjusted through suitable domain design. A unique dual valley spectrum is obtained in a periodically poled lithium niobate structure with a central defect if the sample is placed between two parallel polarizers. The expected bandwidth could be varied from ∼1 nm to ∼40 nm. Moreover, both the spectral response and group delay dispersion could be engineered.

  9. Patient Delay, Diagnosis Delay and Treatment Delay for Breast Cancer: Comparison of the Pattern between Patients in Public and Private Health Sectors

    Directory of Open Access Journals (Sweden)

    Iraj Harirchi

    2015-05-01

    Full Text Available Background: The purpose of this study was to compare patient delay, diagnosis delay and treatment delay in breast cancer patients of selected public and private health centers in Tehran, Iran.Methods: In this cross-sectional study, female patients with newly diagnosed breast cancer in a public medical complex and a private breast clinic within one year were included. Patient delay was considered positive, if the interval between the detection of the first symptom by the patient and the first visit to a health care provider took longer than one month. Delay in diagnosis was defined as the period of more than one week between the first medical visit for the symptoms and the diagnosis of breast cancer. Following the confirmed diagnosis of breast malignancy, if the medical treatment was initiated later than one week, treatment delay had occurred. The potential reasons for patient, diagnosis and treatment delay according to the patients’ reports were also recorded.Results: Overall, 385 patients were included of whom 52.7% were recruited from the public hospitals and 47.3% from a private clinic. The prevalence of patient delay, diagnosis delay and treatment delay were 31.7%, 17.9% and 28.3%, respectively. Patient delay was significantly more common among patients with lower socio-economic status and those recruited from the public hospitals. All the patients with diagnosis delay were in the group recruited from the public hospitals.Conclusions: Gaps between women of different socio-economic levels of the society need to be addressed in order to decrease patient, diagnosis and treatment delay.

  10. Optimizing trial design in pharmacogenetics research: comparing a fixed parallel group, group sequential, and adaptive selection design on sample size requirements.

    Science.gov (United States)

    Boessen, Ruud; van der Baan, Frederieke; Groenwold, Rolf; Egberts, Antoine; Klungel, Olaf; Grobbee, Diederick; Knol, Mirjam; Roes, Kit

    2013-01-01

    Two-stage clinical trial designs may be efficient in pharmacogenetics research when there is some but inconclusive evidence of effect modification by a genomic marker. Two-stage designs allow to stop early for efficacy or futility and can offer the additional opportunity to enrich the study population to a specific patient subgroup after an interim analysis. This study compared sample size requirements for fixed parallel group, group sequential, and adaptive selection designs with equal overall power and control of the family-wise type I error rate. The designs were evaluated across scenarios that defined the effect sizes in the marker positive and marker negative subgroups and the prevalence of marker positive patients in the overall study population. Effect sizes were chosen to reflect realistic planning scenarios, where at least some effect is present in the marker negative subgroup. In addition, scenarios were considered in which the assumed 'true' subgroup effects (i.e., the postulated effects) differed from those hypothesized at the planning stage. As expected, both two-stage designs generally required fewer patients than a fixed parallel group design, and the advantage increased as the difference between subgroups increased. The adaptive selection design added little further reduction in sample size, as compared with the group sequential design, when the postulated effect sizes were equal to those hypothesized at the planning stage. However, when the postulated effects deviated strongly in favor of enrichment, the comparative advantage of the adaptive selection design increased, which precisely reflects the adaptive nature of the design. Copyright © 2013 John Wiley & Sons, Ltd.

  11. The effect of delayed postoperative irradiation on local control of soft tissue sarcomas of the extremity and torso

    International Nuclear Information System (INIS)

    Schwartz, David L.; Einck, John; Hunt, Karen; Bruckner, James; Conrad, Ernest; Koh, W.-J.; Laramore, George E.

    2002-01-01

    Purpose: The impact of delayed adjuvant radiotherapy in patients treated by surgical resection for peripheral or torso soft tissue sarcoma has not been well characterized. We retrospectively examined this issue in an institutional patient cohort. Methods and Materials: One hundred two adult patients were treated at the University of Washington Medical Center between 1981 and 1998 with postoperative radiotherapy for cure of a newly diagnosed soft tissue sarcoma. Of this group, 58 patients had primary intermediate- or high-grade disease of the extremity or torso (50 extremity/8 torso). Tumor histology was predominantly malignant fibrohistiocytoma, synovial cell sarcoma, and leiomyosarcoma. The group was dichotomized according to time interval from definitive resection to the start of adjuvant radiation. Twenty-six patients had a short delay, defined as <4 months, and 32 patients had a long delay of ≥4 months. Both groups were balanced with regard to site, size, margin status, and tumor depth; however, the long-delay group had a larger proportion of high histologic grade lesions and was treated more frequently with chemotherapy (31/32 [97%] for long-delay patients vs. 14/26 [54%] for short-delay patients). Median follow-up was 49.5 months (range: 7-113 months). Median follow-up for patients still alive was 54 months (range: 9-113 months). Survival outcomes were estimated by the Kaplan-Meier method. Results: Overall local relapse-free survival at 5 years from the time of definitive resection was 74%. On univariate analysis, estimated 5-year local relapse-free survival was significantly improved in the short-delay group (88% vs. 62% for the long-delay group, p = 0.048 by log rank). Overall distant relapse-free survival, disease-free survival, and overall survival at 5 years were 77%, 68%, and 86%, respectively. These survival outcomes were statistically equivalent in both radiation delay groups. There was no evidence to suggest that delaying adjuvant systemic therapy

  12. Stability of formation control using a consensus protocol under directed communications with two time delays and delay scheduling

    Science.gov (United States)

    Cepeda-Gomez, Rudy; Olgac, Nejat

    2016-01-01

    We consider a linear algorithm to achieve formation control in a group of agents which are driven by second-order dynamics and affected by two rationally independent delays. One of the delays is in the position and the other in the velocity information channels. These delays are taken as constant and uniform throughout the system. The communication topology is assumed to be directed and fixed. The formation is attained by adding a supplementary control term to the stabilising consensus protocol. In preparation for the formation control logic, we first study the stability of the consensus, using the recent cluster treatment of characteristic roots (CTCR) paradigm. This effort results in a unique depiction of the non-conservative stability boundaries in the domain of the delays. However, CTCR requires the knowledge of the potential stability switching loci exhaustively within this domain. The creation of these loci is done in a new surrogate coordinate system, called the 'spectral delay space (SDS)'. The relative stability is also investigated, which has to do with the speed of reaching consensus. This step leads to a paradoxical control design concept, called the 'delay scheduling', which highlights the fact that the group behaviour may be enhanced by increasing the delays. These steps lead to a control strategy to establish a desired group formation that guarantees spacing among the agents. Example case studies are presented to validate the underlying analytical derivations.

  13. Timing group delay and differential code bias corrections for BeiDou positioning

    Science.gov (United States)

    Guo, Fei; Zhang, Xiaohong; Wang, Jinling

    2015-05-01

    This article first clearly figures out the relationship between parameters of timing group delay (TGD) and differential code bias (DCB) for BDS, and demonstrates the equivalence of TGD and DCB correction models combining theory with practice. The TGD/DCB correction models have been extended to various occasions for BDS positioning, and such models have been evaluated by real triple-frequency datasets. To test the effectiveness of broadcast TGDs in the navigation message and DCBs provided by the Multi-GNSS Experiment (MGEX), both standard point positioning (SPP) and precise point positioning (PPP) tests are carried out for BDS signals with different schemes. Furthermore, the influence of differential code biases on BDS positioning estimates such as coordinates, receiver clock biases, tropospheric delays and carrier phase ambiguities is investigated comprehensively. Comparative analysis show that the unmodeled differential code biases degrade the performance of BDS SPP by a factor of two or more, whereas the estimates of PPP are subject to varying degrees of influences. For SPP, the accuracy of dual-frequency combinations is slightly worse than that of single-frequency, and they are much more sensitive to the differential code biases, particularly for the B2B3 combination. For PPP, the uncorrected differential code biases are mostly absorbed into the receiver clock bias and carrier phase ambiguities and thus resulting in a much longer convergence time. Even though the influence of the differential code biases could be mitigated over time and comparable positioning accuracy could be achieved after convergence, it is suggested to properly handle with the differential code biases since it is vital for PPP convergence and integer ambiguity resolution.

  14. An integrated approach for determining the size of hardwood group-selection openings

    Science.gov (United States)

    Chris B. LeDoux

    1999-01-01

    The use of group-selection methods is becoming more widespread as landowners and forest managers attempt to respond to public pressure to reduce the size of clearcut blocks. Several studies have shown that harvesting timber in smaller groups or clumps increases the cost of operations for both cable and ground-based logging systems. Recent regeneration studies have...

  15. Human Activity Dampens the Benefits of Group Size on Vigilance in Khulan (Equus hemionus in Western China.

    Directory of Open Access Journals (Sweden)

    Mu-Yang Wang

    Full Text Available Animals receive anti-predator benefits from social behavior. As part of a group, individuals spend less time being vigilant, and vigilance decreases with increasing group size. This phenomenon, called "the many-eyes effect", together with the "encounter dilution effect", is considered among the most important factors determining individual vigilance behavior. However, in addition to group size, other social and environmental factors also influence the degree of vigilance, including disturbance from human activities. In our study, we examined vigilance behavior of Khulans (Equus hemionus in the Xinjiang Province in western China to test whether and how human disturbance and group size affect vigilance. According to our results, Khulan showed a negative correlation between group size and the percentage time spent vigilant, although this negative correlation depended on the groups' disturbance level. Khulan in the more disturbed area had a dampened benefit from increases in group size, compared to those in the undisturbed core areas. Provision of continuous areas of high-quality habitat for Khulans will allow them to form larger undisturbed aggregations and to gain foraging benefits through reduced individual vigilance, as well as anti-predator benefits through increased probability of predator detection.

  16. Human Activity Dampens the Benefits of Group Size on Vigilance in Khulan (Equus hemionus) in Western China.

    Science.gov (United States)

    Wang, Mu-Yang; Ruckstuhl, Kathreen E; Xu, Wen-Xuan; Blank, David; Yang, Wei-Kang

    2016-01-01

    Animals receive anti-predator benefits from social behavior. As part of a group, individuals spend less time being vigilant, and vigilance decreases with increasing group size. This phenomenon, called "the many-eyes effect", together with the "encounter dilution effect", is considered among the most important factors determining individual vigilance behavior. However, in addition to group size, other social and environmental factors also influence the degree of vigilance, including disturbance from human activities. In our study, we examined vigilance behavior of Khulans (Equus hemionus) in the Xinjiang Province in western China to test whether and how human disturbance and group size affect vigilance. According to our results, Khulan showed a negative correlation between group size and the percentage time spent vigilant, although this negative correlation depended on the groups' disturbance level. Khulan in the more disturbed area had a dampened benefit from increases in group size, compared to those in the undisturbed core areas. Provision of continuous areas of high-quality habitat for Khulans will allow them to form larger undisturbed aggregations and to gain foraging benefits through reduced individual vigilance, as well as anti-predator benefits through increased probability of predator detection.

  17. Patient delay is the main cause of treatment delay in acute limb ischemia: an investigation of pre- and in-hospital time delay

    DEFF Research Database (Denmark)

    Londero, Louise Skovgaard; Nørgaard, Birgitte; Houlind, Kim Christian

    2014-01-01

    Abstract BACKGROUND: The prognosis of acute limb ischemia is severe, with amputation rates of up to 25% and in-hospital mortality of 9-15%. Delay in treatment increases the risk of major amputation and may be present at different stages, including patient delay, doctors´ delay and waiting time...... in the emergency department. It is important to identify existing problems in order to reduce time delay. The aim of this study was to collect data for patients with acute limb ischemia and to evaluate the time delay between the different events from onset of symptoms to specialist evaluation and further treatment...... (median (range)) was identified. From onset of symptoms to first contact with a doctor the time for all patients were 24 (0-1200) hours. Thirty patients needed immediate intervention. In the group of fourteen patients who had immediate operation, the median time from vascular evaluation...

  18. Delays due to gas diffusion in flash boiling nucleation

    International Nuclear Information System (INIS)

    Hanbury, W.T.; McCartney, W.S.

    1976-01-01

    A theoretical model to account for the time delay between decompression and nucleation in flash boiling is presented and analyzed. It shows that gas diffusion can be responsible for delayed nucleation when the critical radius for nucleation and the suspended particle size are of the same order of magnitude

  19. Permissible Delay in Payments

    Directory of Open Access Journals (Sweden)

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  20. Identifying Otosclerosis with Aural Acoustical Tests of Absorbance, Group Delay, Acoustic Reflex Threshold, and Otoacoustic Emissions.

    Science.gov (United States)

    Keefe, Douglas H; Archer, Kelly L; Schmid, Kendra K; Fitzpatrick, Denis F; Feeney, M Patrick; Hunter, Lisa L

    2017-10-01

    Otosclerosis is a progressive middle-ear disease that affects conductive transmission through the middle ear. Ear-canal acoustic tests may be useful in the diagnosis of conductive disorders. This study addressed the degree to which results from a battery of ear-canal tests, which include wideband reflectance, acoustic stapedius muscle reflex threshold (ASRT), and transient evoked otoacoustic emissions (TEOAEs), were effective in quantifying a risk of otosclerosis and in evaluating middle-ear function in ears after surgical intervention for otosclerosis. To evaluate the ability of the test battery to classify ears as normal or otosclerotic, measure the accuracy of reflectance in classifying ears as normal or otosclerotic, and evaluate the similarity of responses in normal ears compared with ears after surgical intervention for otosclerosis. A quasi-experimental cross-sectional study incorporating case control was used. Three groups were studied: one diagnosed with otosclerosis before corrective surgery, a group that received corrective surgery for otosclerosis, and a control group. The test groups included 23 ears (13 right and 10 left) with normal hearing from 16 participants (4 male and 12 female), 12 ears (7 right and 5 left) diagnosed with otosclerosis from 9 participants (3 male and 6 female), and 13 ears (4 right and 9 left) after surgical intervention from 10 participants (2 male and 8 female). Participants received audiometric evaluations and clinical immittance testing. Experimental tests performed included ASRT tests with wideband reference signal (0.25-8 kHz), reflectance tests (0.25-8 kHz), which were parameterized by absorbance and group delay at ambient pressure and at swept tympanometric pressures, and TEOAE tests using chirp stimuli (1-8 kHz). ASRTs were measured in ipsilateral and contralateral conditions using tonal and broadband noise activators. Experimental ASRT tests were based on the difference in wideband-absorbed sound power before and after

  1. Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign.

    Science.gov (United States)

    Wu, Te Chang; Chen, Tai Yuan; Shiue, Yow Ling; Chen, Jeon Hor; Hsieh, Tsyh-Jyi; Ko, Ching Chung; Lin, Ching Po

    2018-04-01

    Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA ( P spot sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

  2. Delayed discounting of pain with and without monetary reward

    Directory of Open Access Journals (Sweden)

    Kicman Paweł

    2017-12-01

    Full Text Available We investigated the effect of monetary rewards on the rate of pain discounting. Our aim, also, was to understand the effect of previous painful dental experiences on the rate of discounting pain. Two groups (N = 148 completed a discounting task. In the first group, delayed pain was weaker than immediate pain, and in the second group delayed pain was stronger than immediate pain. Two conditions were studied: pain was either accompanied by a monetary reward or not. We found that people preferred immediate pain when it was weaker than delayed pain; however, when delayed pain was stronger than immediate pain, there was no clear preference. In both groups the preference for immediate pain was higher when pain was accompanied by a monetary reward. Previous painful experiences were not related to the rate of discounting. It was concluded that the preference for delayed pain depends on the intensity of pain, and it can be modified by rewards that accompany pain.

  3. Viral Richness is Positively Related to Group Size, but Not Mating System, in Bats.

    Science.gov (United States)

    Webber, Quinn M R; Fletcher, Quinn E; Willis, Craig K R

    2017-12-01

    Characterizing host traits that influence viral richness and diversification is important for understanding wildlife pathogens affecting conservation and/or human health. Behaviors that affect contact rates among hosts could be important for viral diversification because more frequent intra- and inter-specific contacts among hosts should increase the potential for viral diversification within host populations. We used published data on bats to test the contact-rate hypothesis. We predicted that species forming large conspecific groups, that share their range with more heterospecifics (i.e., sympatry), and with mating systems characterized by high contact rates (polygynandry: multi-male/multi-female), would host higher viral richness than species with small group sizes, lower sympatry, or low contact-rate mating systems (polygyny: single male/multi-female). Consistent with our hypothesis and previous research, viral richness was positively correlated with conspecific group size although the relationship plateaued at group sizes of approximately several hundred thousand bats. This pattern supports epidemiological theory that, up to a point, larger groups have higher contact rates, greater likelihood of acquiring and transmitting viruses, and ultimately greater potential for viral diversification. However, contrary to our hypothesis, there was no effect of sympatry on viral richness and no difference in viral richness between mating systems. We also found no residual effect of host phylogeny on viral richness, suggesting that closely related species do not necessarily host similar numbers of viruses. Our results support the contact-rate hypothesis that intra-specific viral transmission can enhance viral diversification within species and highlight the influence of host group size on the potential of viruses to propagate within host populations.

  4. Group size adjustment to ecological demand in a cooperative breeder.

    Science.gov (United States)

    Zöttl, Markus; Frommen, Joachim G; Taborsky, Michael

    2013-04-07

    Environmental factors can determine which group size will maximize the fitness of group members. This is particularly important in cooperative breeders, where group members often serve different purposes. Experimental studies are yet lacking to check whether ecologically mediated need for help will change the propensity of dominant group members to accept immigrants. Here, we manipulated the perceived risk of predation for dominant breeders of the cooperatively breeding cichlid fish Neolamprologus pulcher to test their response to unrelated and previously unknown immigrants. Potential immigrants were more readily accepted if groups were exposed to fish predators or egg predators than to herbivorous fish or control situations lacking predation risk. Our data are consistent with both risk dilution and helping effects. Egg predators were presented before spawning, which might suggest that the fish adjust acceptance rates also to a potential future threat. Dominant group members of N. pulcher apparently consider both present and future need of help based on ecological demand. This suggests that acceptance of immigrants and, more generally, tolerance of group members on demand could be a widespread response to ecological conditions in cooperatively breeding animals.

  5. The effect of group size on vigilance in Ruddy Turnstones Arenaria interpres varies with foraging habitat

    NARCIS (Netherlands)

    Fuller, Richard A.; Bearhop, Stuart; Metcalfe, Neil B.; Piersma, Theunis

    Foraging birds can manage time spent vigilant for predators by forming groups of various sizes. However, group size alone will not always reliably determine the optimal level of vigilance. For example, variation in predation risk or food quality between patches may also be influential. In a field

  6. Local Control for Intermediate-Risk Rhabdomyosarcoma: Results From D9803 According to Histology, Group, Site, and Size: A Report From the Children's Oncology Group

    Energy Technology Data Exchange (ETDEWEB)

    Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Lyden, Elizabeth R. [Department of Preventive and Societal Medicine, Nebraska Medical Center, Omaha, Nebraska (United States); Arndt, Carola A. [Department of Pediatric and Adolescent Medicine, Mayo Clinic and Foundation, Rochester, Minnesota (United States); Hawkins, Douglas S. [Division of Hematology/Oncology, Seattle Children' s Hospital, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington (United States); Anderson, James R. [Frontier Science and Technology Research Foundation, Madison, Wisconsin (United States); Rodeberg, David A. [Department of Surgery, East Carolina University, Greenville, North Carolina (United States); Morris, Carol D. [Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Donaldson, Sarah S. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States)

    2015-12-01

    Purpose: To determine local control according to clinical variables for patients with intermediate-risk rhabdomyosarcoma (RMS) treated on Children's Oncology Group protocol D9803. Patients and Methods: Of 702 patients enrolled, we analyzed 423 patients with central pathology–confirmed group III embryonal (n=280) or alveolar (group III, n=102; group I-II, n=41) RMS. Median age was 5 years. Patients received 42 weeks of VAC (vincristine, dactinomycin, cyclophosphamide) or VAC alternating with VTC (T = topotecan). Local therapy with 50.4 Gy radiation therapy with or without delayed primary excision began at week 12 for group III patients. Patients with group I/II alveolar RMS received 36-41.4 Gy. Local failure (LF) was defined as local progression as a first event with or without concurrent regional or distant failure. Results: At a median follow-up of 6.6 years, patients with clinical group I/II alveolar RMS had a 5-year event-free survival rate of 69% and LF of 10%. Among patients with group III RMS, 5-year event-free survival and LF rates were 70% and 19%, respectively. Local failure rates did not differ by histology, nodal status, or primary site, though there was a trend for increased LF for retroperitoneal (RP) tumors (P=.12). Tumors ≥5 cm were more likely to fail locally than tumors <5 cm (25% vs 10%, P=.0004). Almost all (98%) RP tumors were ≥5 cm, with no difference in LF by site when the analysis was restricted to tumors ≥5 cm (P=.86). Conclusion: Local control was excellent for clinical group I/II alveolar RMS. Local failure constituted 63% of initial events in clinical group III patients and did not vary by histology or nodal status. The trend for higher LF in RP tumors was related to tumor size. There has been no clear change in local control over RMS studies, including IRS-III and IRS-IV. Novel approaches are warranted for larger tumors (≥5 cm).

  7. Television viewing associates with delayed language development.

    Science.gov (United States)

    Chonchaiya, Weerasak; Pruksananonda, Chandhita

    2008-07-01

    To identify impact of television viewing on language development. The case-control study included 56 new patients with language delay and 110 normal children, aged 15-48 months. Language delay was diagnosed by reviewing language milestones and Denver-II. Television viewing variables and child/parental characteristics between both groups were interviewed. The data were analyzed by ANOVA and chi-square test. Adjusted odds ratios and 95% confidence intervals were calculated from multivariate logistic regression model. Forty-six boys and 10 girls; mean [+/-SD] age, 2.11+/-0.47 years of the case group and 59 boys and 51 girls; mean [+/-SD] age, 2.23+/-0.80 years of the control group were enrolled. Children who had language delay usually started watching television earlier at age 7.22+/-5.52 months vs. 11.92+/-5.86 months, p-valuetelevision than normal children (3.05+/-1.90 h/day vs. 1.85+/-1.18 h/day; p-valuetelevision attelevision>2 h/day were approximately six times more likely to have language delays. There is a relationship between early onset and high frequency of TV viewing and language delay.

  8. Whistle rates of wild bottlenose dolphins (Tursiops truncatus): influences of group size and behavior.

    Science.gov (United States)

    Quick, Nicola J; Janik, Vincent M

    2008-08-01

    In large social groups acoustic communication signals are prone to signal masking by conspecific sounds. Bottlenose dolphins (Tursiops truncatus) use highly distinctive signature whistles that counter masking effects. However, they can be found in very large groups where masking by conspecific sounds may become unavoidable. In this study we used passive acoustic localization to investigate how whistle rates of wild bottlenose dolphins change in relation to group size and behavioral context. We found that individual whistle rates decreased when group sizes got larger. Dolphins displayed higher whistle rates in contexts when group members were more dispersed as in socializing and in nonpolarized movement than during coordinated surface travel. Using acoustic localization showed that many whistles were produced by groups nearby and not by our focal group. Thus, previous studies based on single hydrophone recordings may have been overestimating whistle rates. Our results show that although bottlenose dolphins whistle more in social situations they also decrease vocal output in large groups where the potential for signal masking by other dolphin whistles increases.

  9. State-dependent neutral delay equations from population dynamics.

    Science.gov (United States)

    Barbarossa, M V; Hadeler, K P; Kuttler, C

    2014-10-01

    A novel class of state-dependent delay equations is derived from the balance laws of age-structured population dynamics, assuming that birth rates and death rates, as functions of age, are piece-wise constant and that the length of the juvenile phase depends on the total adult population size. The resulting class of equations includes also neutral delay equations. All these equations are very different from the standard delay equations with state-dependent delay since the balance laws require non-linear correction factors. These equations can be written as systems for two variables consisting of an ordinary differential equation (ODE) and a generalized shift, a form suitable for numerical calculations. It is shown that the neutral equation (and the corresponding ODE--shift system) is a limiting case of a system of two standard delay equations.

  10. A Life-Cycle Model of Human Social Groups Produces a U-Shaped Distribution in Group Size.

    Directory of Open Access Journals (Sweden)

    Gul Deniz Salali

    Full Text Available One of the central puzzles in the study of sociocultural evolution is how and why transitions from small-scale human groups to large-scale, hierarchically more complex ones occurred. Here we develop a spatially explicit agent-based model as a first step towards understanding the ecological dynamics of small and large-scale human groups. By analogy with the interactions between single-celled and multicellular organisms, we build a theory of group lifecycles as an emergent property of single cell demographic and expansion behaviours. We find that once the transition from small-scale to large-scale groups occurs, a few large-scale groups continue expanding while small-scale groups gradually become scarcer, and large-scale groups become larger in size and fewer in number over time. Demographic and expansion behaviours of groups are largely influenced by the distribution and availability of resources. Our results conform to a pattern of human political change in which religions and nation states come to be represented by a few large units and many smaller ones. Future enhancements of the model should include decision-making rules and probabilities of fragmentation for large-scale societies. We suggest that the synthesis of population ecology and social evolution will generate increasingly plausible models of human group dynamics.

  11. Group size and nest success in red-cockaded woodpeckers in the West Gulf Coastal Plain: helpers make a difference

    Science.gov (United States)

    Richard N. Conner; Daniel Saenz; Richard R. Schaefer; James R. McCormick; D. Craig Rudolph; D. Brent Burt

    2004-01-01

    We studied the relationships between Red-cockaded Woodpecker (Picoides borealis) group size and nest productivity. Red-cockaded Woodpecker group size was positively correlated with fledging success. Although the relationships between woodpecker group size and nest productivity measures were nor statistically significant, a pattern of...

  12. Does goal relevant episodic future thinking amplify the effect on delay discounting?

    Science.gov (United States)

    O'Donnell, Sara; Oluyomi Daniel, Tinuke; Epstein, Leonard H

    2017-05-01

    Delay discounting (DD) is the preference for smaller immediate rewards over larger delayed rewards. Research shows episodic future thinking (EFT), or mentally simulating future experiences, reframes the choice between small immediate and larger delayed rewards, and can reduce DD. Only general EFT has been studied, whereby people reframe decisions in terms of non-goal related future events. Since future thinking is often goal-oriented and leads to greater activation of brain regions involved in prospection, goal-oriented EFT may be associated with greater reductions in DD than general goal-unrelated EFT. The present study (n=104, M age =22.25, SD=3.42; 50% Female) used a between-subjects 2×2 factorial design with type of episodic thinking (Goal, General) and temporal perspective (Episodic future versus recent thinking; EFT vs ERT) as between factors. Results showed a significant reduction in DD for EFT groups (p<0.001, Cohen's d effect size=0.89), and goal-EFT was more effective than general-EFT on reducing DD (p=0.03, d=0.64). Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Early versus delayed rehabilitation following arthroscopic rotator cuff repair: A systematic review.

    Science.gov (United States)

    Gallagher, Brian P; Bishop, Meghan E; Tjoumakaris, Fotios P; Freedman, Kevin B

    2015-05-01

    Early passive range of motion (ROM) following arthroscopic cuff repair is thought to decrease postoperative stiffness and improve functionality. However, early aggressive rehabilitation may compromise repair integrity. Our purpose was to perform a systematic review to determine if there are differences between early and delayed rehabilitation after arthroscopic rotator cuff repair in terms of clinical outcomes and healing. We performed a literature search with the terms 'arthroscopic rotator cuff', 'immobilization', 'early', 'delayed', 'late', and 'rehabilitation' using PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Selection criteria included: level I/II evidence ≤ 6 months in duration, comparing early versus delayed rehabilitation following arthroscopic repair. Data regarding demographics, sample sizes, duration, cuff pathology, surgery, rehabilitation, functional outcomes, pain, ROM and anatomic assessment of healing were analyzed. PRIMSA criteria were followed. We identified six articles matching our criteria. Three reported significantly increased functional scores within the first 3-6 months with early rehabilitation compared to the delayed group, only one of which continued to observe a difference at a final follow-up of 15 months. Four articles showed improved ROM in the first 3-6 months post-operatively with early rehabilitation. One noted transient differences in pain scores. Only one study noted significant differences in ROM at final follow-up. No study reported any significant difference in rates of rotator cuff re-tear. However, two studies noted a trend towards increased re-tear with early rehabilitation that did not reach significance. This was more pronounced in studies including medium-large tears. Early rehabilitation after arthroscopic cuff repair is associated with some initial improvements in ROM and function. Ultimately, similar clinical and anatomical outcomes between groups existed at 1 year. While there was no

  14. Micrometer-sized TPM emulsion droplets with surface-mobile binding groups

    Science.gov (United States)

    van der Wel, Casper; van de Stolpe, Guido L.; Verweij, Ruben W.; Kraft, Daniela J.

    2018-03-01

    Colloids coated with lipid membranes have been widely employed for fundamental studies of lipid membrane processes, biotechnological applications such as drug delivery and biosensing, and more recently, for self-assembly. The latter has been made possible by inserting DNA oligomers with covalently linked hydrophobic anchors into the membrane. The lateral mobility of the DNA linkers on micrometer-sized droplets and solid particles has opened the door to creating structures with unprecedented structural flexibility. Here, we investigate micro-emulsions of TPM (3-(trimethoxysilyl)propyl methacrylate) as a platform for lipid monolayers and further functionalization with proteins and DNA oligonucleotides. TPM droplets can be produced with a narrow size distribution and are polymerizable, thus providing supports for model lipid membranes with controlled size and curvature. With fluorescence recovery after photobleaching, we observed that droplet-attached lipids, NeutrAvidin proteins, as well as DNA oligonucleotides all show mobility on the surface. We explored the assembly of micron-sized particles on TPM-droplets by exploiting either avidin-biotin interactions or double-stranded DNA with complementary single-stranded end groups. While the single molecules are mobile, the particles that are attached to them are not. We propose that this is caused by the heterogeneous nature of emulsified TPM, which forms an oligomer network that limits the collective motion of linkers, but allows the surface mobility of individual molecules.

  15. Characters of neutron noise in full-size molten salt reactor

    International Nuclear Information System (INIS)

    Wang, Jiangmeng; Cao, Xinrong

    2015-01-01

    Highlights: • The larger system size makes full-size MSR deviate from point kinetic behavior. • The increasing velocity has non-monotonic effect on the effective delayed neutron fraction. • The amplitude of Green’s function at low frequencies is inversely proportional to the effective delayed neutron fraction. • The range of plateau region is smaller due to the more prominent point kinetic effect. - Abstract: In the present paper, the frequency-dependent and space-dependent behavior of the neutron noise in a full-size Molten Salt Reactor (MSR) is investigated. The theoretical models considering the fuel circulation are established based on one-group neutron diffusion theory. Green’s function of the neutron noise induced by a propagating perturbation is introduced with linear noise theory, due to the small perturbation. The equations are numerically calculated by developing a code, in which the eigenfunction expansion method is adopted. The static results show that the effective delayed neutron fraction changes non-monotonically with the increasing fuel velocity. In the dynamic case, the results are compared to those obtained in 1D MSR and a traditional reactor, in order to figure out the effects of both the fuel circulation and the system size. It is found that there is no difference in 1D and 3D MSR systems from the view of fuel circulation, i.e., the fuel circulation enhances the spatial neutronic coupling and leads to the stronger point kinetic effect. The more prominent space-dependent effect founded in 3D traditional reactors is also observed in the MSR, due to the looser neutronic coupling and the unique singularity of Green’s function in the location of the perturbation. Another interesting finding is that Green’s function for low frequencies changes non-monotonically with increasing velocity. The largest magnitude of Green’s function is observed at the velocity where the effective delayed neutron fraction reaches its minimum. Finally, the

  16. Delayed somatic effects following extended radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Slanina, J

    1977-10-27

    A group of 135 patients was investigated, who suffered from Hodgkin's disease with long-term remission following radiotherapy. By restricting the investigations to the patient group with long-term remission and correlative examinations, differentiation was made between exclusive or principal delayed radiation effects and delayed effects due to other factors. The study reports the most significant results obtained in the fields of catamnesis, laboratory diagnostics, hematology, pulmology, cardiology, thyroid function tests, neurology, andrology and dermatology. Due to the numerous detectable delayed effects the group of patients with long-term remission receives a special status. Although those effects are in no proportion to the deletary risks of an untreated Hodgkin's disease and though they are consequently tolerable in the present state of the therapeutic development, they must initiate the completion of the therapeutic concept including performance of radiotherapy and aftercare, because only then the risk for the patient provoked by these effects, which ranges beyond the malignity of this disease can be reduced or prevented.

  17. Metastable structures and size effects in small group dynamics

    Directory of Open Access Journals (Sweden)

    Rosapia eLauro Grotto

    2014-07-01

    Full Text Available In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: 1 they emerge as a consequence of the natural tendency of (both conscious and unconscious emotions to combine into structured group patterns; 2 they have a certain degree of stability in time; 3 they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; 4 they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical 'leadership’ pattern, and in 'cognitive’ terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e. the group behaves 'as if’ it was assuming that…. Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: 1 are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? 3 can these states be differentiated in structural terms? 3 to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical

  18. Metastable structures and size effects in small group dynamics.

    Science.gov (United States)

    Lauro Grotto, Rosapia; Guazzini, Andrea; Bagnoli, Franco

    2014-01-01

    In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: (1) they emerge as a consequence of the natural tendency of (both conscious and unconscious) emotions to combine into structured group patterns; (2) they have a certain degree of stability in time; (3) they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; (4) they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical "leadership" pattern, and in "cognitive" terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e., the group behaves "as if" it was assuming that). Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: (1) are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? (2) can these states be differentiated in structural terms? (3) to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical setting.

  19. Why Irish women delay seeking treatment for urinary incontinence : a focus group study

    OpenAIRE

    Ni Aileasa, Mairead

    2011-01-01

    non-peer-reviewed Background: Urinary Incontinence is defined as "any involuntary leakage of urine" (Abrams et al, 2002). Living with incontinence can effect one's life greatly. Many women delay seeking treatment and often do not seek any help (Dolan et al, 1999), despite physiotherapy being an effective treatment (Neumann et al, 2005). Therefore, there is a need to discover why women delay seeking help, such as physiotherapy and continue to live with incontinence. Objectives: To establ...

  20. Four-channel delay generator model 5740

    International Nuclear Information System (INIS)

    Baumatz, D.; Milner, M.

    1978-01-01

    The 4-channel delay generator model 5740 generates 4-pulse groups in independent channels. The device offers the possibility of controlling both the time intervals between the pulses of a group and the rate of generation of groups

  1. Isolating the delay component of impulsive choice in adolescent rats

    Directory of Open Access Journals (Sweden)

    Jesse eMcClure

    2014-01-01

    Full Text Available Impulsive choice — the preference for small immediate rewards over larger delayed rewards — has been linked to various psychological conditions ranging from behavioral disorders to addiction. These links highlight the critical need to dissect the various components of this multifaceted behavioral trait. Delay discounting tasks allow researchers to study an important factor of this behavior: how the subjective value of a rewards changes over a delay period. However, existing methods of delay discounting include a confound of modifying reward sizes during the procedure. Here we present a new approach of using a single constant reward size to assess delay discounting. A complementary approach could hold delay constant and assess the utility of changing quantities of a reward. Isolating these behavioral components can advance our ability to explore the behavioral complexity of impulsive choice. We present the methods for isolating delay in detail, and further capitalize on this method by pairing it with a standard peak interval task to test whether individual variation in delay discounting can be explained by differences in perception of time in male and female adolescent rats. We find that rats that were more precise in discriminating time intervals were also less impulsive in their choice. Our data suggest that differences in timing and delay discounting are not causally related, but instead are more likely influenced by a common factor. Further, the mean-level change in our measure between postnatal day 28 and 42 suggests this test may be capturing a developmental change in this factor. In summary, this new method of isolating individual components of impulsive choice (delay or quantity can be efficiently applied in either adolescent or adult animal models and may help elucidate the mechanisms underlying impulsivity and its links to psychological disorders.

  2. Robustness of unstable attractors in arbitrarily sized pulse-coupled networks with delay

    NARCIS (Netherlands)

    Broer, Hendrik; Efstathiou, Konstantinos; Subramanian, Easwar

    We consider arbitrarily large networks of pulse-coupled oscillators with non-zero delay where the coupling is given by the Mirollo-Strogatz function. We prove that such systems have unstable attractors (saddle periodic orbits whose stable set has non-empty interior) in an open parameter region for

  3. Energy dependence of relative abundances and periods of delayed neutron separate groups from neutron induced fission of 239Pu in the virgin neutron energy range 0.37-4.97 MeV

    International Nuclear Information System (INIS)

    Piksajkin, V.M.; Kazakov, L.E.; Isaev, S.T.; Korolev, G.G.; Roshchenko, V.A.; Tertychnyj, R.G.

    2002-01-01

    Relative yield and group period of delayed neutrons induced by the 239 Pu fission in the 0.37-4.97 MeV range were measured. Comparative analysis of experimental data was conducted in terms of middle period of half-life of delayed neutron nuclei-precursors. Character and scale of changing values of delayed neutron group parameters as changing excitation energy of fission compound-nucleus have been demonstrated for the first time. Considerable energy dependence of group parameters under the neutron induced 239 Pu fission that was expressed by the decreasing middle period of half-life of nuclei-precursors by 10 % in the 2.85 eV - 5 MeV range of virgin neutrons was detected [ru

  4. Exploring delay causes of road construction projects in

    Directory of Open Access Journals (Sweden)

    Remon F. Aziz

    2016-06-01

    Full Text Available Construction delays are a common phenomenon in civil engineering projects in Egypt including road construction projects. Therefore, it is essential to study and analyze causes of road construction delays. This paper studied a list of construction delay causes gathered from literature having different types of construction, different countries, different periods and different numbers of delay causes and delay groups. A questionnaire and personal interviews have formed the basis of this paper listing 293 delay causes. The questionnaire survey was distributed to 500 construction participants and 389 were received who represent consultants, contractors and site/design engineers excluding the owner representing the government in road projects as one party only. Relative Importance Index (RII is calculated and according to the highest values the top twenty and the least twenty delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the paper. The test results reveal good correlation of causes and groups between contractors and site/design engineers and between consultants and site design engineers and a somewhat low correlation between contractors and consultants. So there are no root causes that can be taking for granted to be most or least effective delay causes. Proposed model for predicting actual road construction project duration was developed; a real case study tested the accuracy of proposed model. According to the analysis of case study, the most contributing causes and groups to delays were discussed, and some future recommendations were proposed in order to control and minimize delays in road construction projects. These findings can be helpful for project managers to mitigate the road construction delays in Egypt. In order to effectively overcome the road construction delays in developing countries, suggestions are made for fundamental and large

  5. Relation between delay and survival in 596 patients with breast cancer.

    Science.gov (United States)

    Machiavelli, M; Leone, B; Romero, A; Perez, J; Vallejo, C; Bianco, A; Rodriguez, R; Estevez, R; Chacon, R; Dansky, C

    1989-01-01

    To evaluate the influence of delay between first symptom and first treatment upon survival the medical records of 596 patients with breast cancer were reviewed. The following intervals were considered: less than 3 months; 3-6 months and greater than 6 months. Patients in the less than 3 months delay group had a better distribution by clinical stages and a 10-year survival rate higher than those in the longer delay groups (p = 0.034). However, within each stage no statistically significant difference in survival according to delay was observed. A Cox multivariate analysis revealed that performance status and stage of disease were independent predictors of survival, but not delay. Assuming the best prognosis for patients with clinical stages I and II and less than 3 months delay, the group with longer delay times had 15 deaths over what would have been predicted. This adverse effect was observed almost exclusively among patients over age 50 (14/15).

  6. What about N? A methodological study of sample-size reporting in focus group studies.

    Science.gov (United States)

    Carlsen, Benedicte; Glenton, Claire

    2011-03-11

    Focus group studies are increasingly published in health related journals, but we know little about how researchers use this method, particularly how they determine the number of focus groups to conduct. The methodological literature commonly advises researchers to follow principles of data saturation, although practical advise on how to do this is lacking. Our objectives were firstly, to describe the current status of sample size in focus group studies reported in health journals. Secondly, to assess whether and how researchers explain the number of focus groups they carry out. We searched PubMed for studies that had used focus groups and that had been published in open access journals during 2008, and extracted data on the number of focus groups and on any explanation authors gave for this number. We also did a qualitative assessment of the papers with regard to how number of groups was explained and discussed. We identified 220 papers published in 117 journals. In these papers insufficient reporting of sample sizes was common. The number of focus groups conducted varied greatly (mean 8.4, median 5, range 1 to 96). Thirty seven (17%) studies attempted to explain the number of groups. Six studies referred to rules of thumb in the literature, three stated that they were unable to organize more groups for practical reasons, while 28 studies stated that they had reached a point of saturation. Among those stating that they had reached a point of saturation, several appeared not to have followed principles from grounded theory where data collection and analysis is an iterative process until saturation is reached. Studies with high numbers of focus groups did not offer explanations for number of groups. Too much data as a study weakness was not an issue discussed in any of the reviewed papers. Based on these findings we suggest that journals adopt more stringent requirements for focus group method reporting. The often poor and inconsistent reporting seen in these

  7. What about N? A methodological study of sample-size reporting in focus group studies

    Directory of Open Access Journals (Sweden)

    Glenton Claire

    2011-03-01

    Full Text Available Abstract Background Focus group studies are increasingly published in health related journals, but we know little about how researchers use this method, particularly how they determine the number of focus groups to conduct. The methodological literature commonly advises researchers to follow principles of data saturation, although practical advise on how to do this is lacking. Our objectives were firstly, to describe the current status of sample size in focus group studies reported in health journals. Secondly, to assess whether and how researchers explain the number of focus groups they carry out. Methods We searched PubMed for studies that had used focus groups and that had been published in open access journals during 2008, and extracted data on the number of focus groups and on any explanation authors gave for this number. We also did a qualitative assessment of the papers with regard to how number of groups was explained and discussed. Results We identified 220 papers published in 117 journals. In these papers insufficient reporting of sample sizes was common. The number of focus groups conducted varied greatly (mean 8.4, median 5, range 1 to 96. Thirty seven (17% studies attempted to explain the number of groups. Six studies referred to rules of thumb in the literature, three stated that they were unable to organize more groups for practical reasons, while 28 studies stated that they had reached a point of saturation. Among those stating that they had reached a point of saturation, several appeared not to have followed principles from grounded theory where data collection and analysis is an iterative process until saturation is reached. Studies with high numbers of focus groups did not offer explanations for number of groups. Too much data as a study weakness was not an issue discussed in any of the reviewed papers. Conclusions Based on these findings we suggest that journals adopt more stringent requirements for focus group method

  8. An experimental study of tumour size and radiosensitivity

    International Nuclear Information System (INIS)

    Hill, S.A.; Denekamp, J.

    1989-01-01

    When designing experimental studies of tumours, it is considered important to control all variables that might alter the radiosensitivity and hence influence the variability of the data. One such variable is tumour size. We have studied the regrowth delay of a mammary carcinoma treated at 2-10 mm mean diameter (a 125-fold change of volume) with X-rays alone or X-rays plus misonidazole (MISO). The data were analysed to give dose-response curves, using four endpoints. Regrowth to a fixed size (4.5 mm larger than treatment size), or by a fixed increment (4 times the original volume) was expressed either as absolute delay, or as specific growth delay to allow for the changes in volume doubling time as the tumour grows. The method of analysis made no difference to the measured sensitizer enhancement ratio (SER) for MISO. The SER was dose-dependent, being higher doses, but was not different in tumours of 2 or 10 mm diameter. However, when comparing response to X-rays alone, the method of analysis made a very big difference to the conclusions. Regrowth to R + 4.5 mm showed no change in radiosensitivity with tumour size, but regrowth to 4 times the original volume (the most logical endpoint) indicated that large tumours were more sensitive than small. We conclude that regrowth delay may be an inappropriate method for comparing absolute sensitivities of tumours of different sizes. However, for studying the effectiveness of a radiomodifier the constraints of tumour size at irradiation seem to be less severe than previously believed. (author). 8 refs.; 8 figs

  9. Dampak Konvergensi IFRS, Karakteristik Perusahaan, dan Kualitas Auditor Terhadap Audit Delay

    Directory of Open Access Journals (Sweden)

    Dwi Ratmono

    2016-03-01

    Full Text Available The objective of this study is to examine the influence of IFRS implementation on the audit delay. To focus on the impact of audit delay, this study controls the effect of company’s characteristics.  Characteristics of the company used in this study are the company size, the leverage, and the loss announcement. The population used in this study is all of the manufacturing company listed in Indonesia Stock Exchange for 2010 until 2013 period. The study uses the purposive sampling for the sampling method. The criteria of the sample which is used is company must have published audited financial report for four years successively and used Rupiah, so that  the number of the sample in this study is 416 observations. There are two variables that do not affect the audit delay, those IFRS implementation, and loss announcement..The results shows that the company size, leverage and the auditor’s quality significantly affect audit delay.

  10. Delayed wound healing after forefoot surgery in patients with rheumatoid arthritis.

    Science.gov (United States)

    Ishie, Shinichiro; Ito, Hiromu; Azukizawa, Masayuki; Furu, Moritoshi; Ishikawa, Masahiro; Ogino, Hiroko; Hamamoto, Yosuke; Matsuda, Shuichi

    2015-05-01

    To elucidate the systemic and local risk factors and the effect of surgical procedures for delayed wound healing after forefoot surgery in patients with rheumatoid arthritis (RA). Fifty forefoot surgeries were performed in 39 patients using resection arthroplasty or a joint-preserving procedure (25 feet for each procedure). The associations between the occurrence of delayed wound healing and clinical variables, radiological assessment, or surgical procedures were analyzed. Delayed wound healing was recorded in nine feet of eight patients. The duration of RA was significantly longer in the delayed healing group than that in the healed group. Age, sex, smoking history, concomitant diabetes, and RA medication did not differ between the groups. Radiological evaluation showed significant differences between groups in metatarsophalangeal dorsal flexion angle. The shortened length of the fourth and the fifth metatarsal bones affected the occurrence of the complication. The joint-preserving procedure had significantly less delayed wound healing compared with resection arthroplasty. Preoperative dorsoplantar deformity and perioperative tissue damage can cause delayed wound healing after forefoot surgery in RA patients.

  11. Turn-on delay of QD and QW laser diodes: What is the difference?

    International Nuclear Information System (INIS)

    Sokolovskii, G S; Dudelev, V V; Kolykhalova, E D; Deryagin, A G; Maximov, M V; Nadtochiy, A M; Kuchinskii, V I; Mikhrin, S S; Livshits, D A; Viktorov, E A; Erneux, T

    2013-01-01

    Turn-on delay of laser diodes with quantum-sized active media is investigated both theoretically and experimentally. In this research we show the striking difference in turn-on delay of quantum dot and quantum well laser diodes: With quantum-well lasers turn on delay tends to zero in the limit of high pumping, while with quantum dot lasers turn-on delay has the non-vanishing component which is independent of pumping

  12. Influence of group size on the success of wolves hunting bison.

    Science.gov (United States)

    MacNulty, Daniel R; Tallian, Aimee; Stahler, Daniel R; Smith, Douglas W

    2014-01-01

    An intriguing aspect of social foraging behaviour is that large groups are often no better at capturing prey than are small groups, a pattern that has been attributed to diminished cooperation (i.e., free riding) in large groups. Although this suggests the formation of large groups is unrelated to prey capture, little is known about cooperation in large groups that hunt hard-to-catch prey. Here, we used direct observations of Yellowstone wolves (Canis lupus) hunting their most formidable prey, bison (Bison bison), to test the hypothesis that large groups are more cooperative when hunting difficult prey. We quantified the relationship between capture success and wolf group size, and compared it to previously reported results for Yellowstone wolves hunting elk (Cervus elaphus), a prey that was, on average, 3 times easier to capture than bison. Whereas improvement in elk capture success levelled off at 2-6 wolves, bison capture success levelled off at 9-13 wolves with evidence that it continued to increase beyond 13 wolves. These results are consistent with the hypothesis that hunters in large groups are more cooperative when hunting more formidable prey. Improved ability to capture formidable prey could therefore promote the formation and maintenance of large predator groups, particularly among predators that specialize on such prey.

  13. Influence of group size on the success of wolves hunting bison.

    Directory of Open Access Journals (Sweden)

    Daniel R MacNulty

    Full Text Available An intriguing aspect of social foraging behaviour is that large groups are often no better at capturing prey than are small groups, a pattern that has been attributed to diminished cooperation (i.e., free riding in large groups. Although this suggests the formation of large groups is unrelated to prey capture, little is known about cooperation in large groups that hunt hard-to-catch prey. Here, we used direct observations of Yellowstone wolves (Canis lupus hunting their most formidable prey, bison (Bison bison, to test the hypothesis that large groups are more cooperative when hunting difficult prey. We quantified the relationship between capture success and wolf group size, and compared it to previously reported results for Yellowstone wolves hunting elk (Cervus elaphus, a prey that was, on average, 3 times easier to capture than bison. Whereas improvement in elk capture success levelled off at 2-6 wolves, bison capture success levelled off at 9-13 wolves with evidence that it continued to increase beyond 13 wolves. These results are consistent with the hypothesis that hunters in large groups are more cooperative when hunting more formidable prey. Improved ability to capture formidable prey could therefore promote the formation and maintenance of large predator groups, particularly among predators that specialize on such prey.

  14. A re-examination of the effect of contextual group size on people's attitude to risk

    Directory of Open Access Journals (Sweden)

    Kazumi Shimizu

    2011-02-01

    Full Text Available Using Kahneman and Tversky's life-death decision paradigm, Wang and colleagues (e.g., Wang and Johnston, 1995; Wang, 1996a, 1996b, 1996c, 2008; Wang et al., 2001 have shown two characteristic phenomena regarding people's attitude to risk when the contextual group size is manipulated. In both positive and negative frames, people tend to take greater risks in life-death decisions as the contextual group size becomes smaller; this risk-seeking attitude is greater when framed positively than negatively. (This second characteristic often leads to the disappearance of the framing effect in small group contexts comprising of 6 or 60 people. Their results could shed new light on the effect of contextual group size on people's risk choice. However these results are usually observed in laboratory experiments with university student samples. This study aims to examine the external validity of these results through different ways of experimentation and with a different sample base. The first characteristic was replicated in both a face-to-face interview with a randomly selected sample of the Japanese general public, and a web-based experiment with a non-student sample, but not the second.

  15. The significance of resting thallium-201 delayed SPECT for assessing viability of infarcted regions

    International Nuclear Information System (INIS)

    Mori, Takao; Yamabe, Hiroshi; Yoshida, Hiroyuki; Maeda, Kazumi; Fukuzaki, Hisashi

    1991-01-01

    Thirty-eight patients with old myocardial infarction (OMI) and 35 patients with effort angina pectoris (EAP) underwent resting thallium-201 (Tl) SPECT one week after exercise (Ex) Tl SPECT. On the basis of both resting and Ex Tl SPECT scans, OMI patients were divided into 3 groups: those who had Tl redistribution (RD) on Ex images and the same perfusion defect (PD) on both resting and Ex delayed images (n=12, Group 1); those who had a lower PD on resting delayed images than Ex delayed images (n=15, Group 2); and those who had no Tl RD on Ex images in spite of the same PD on both resting and EX delayed images (n=11, Group 3). EAP patients were divided into Group 1 (n=18) in whom no PD was seen on Ex delayed image and Group 2 (n=17) in whom PD was not seen on Ex delayed images either, but seen on resting delayed images. EX images showed higher pulmonary artery wedge pressure in Group 2 than Group 1 of both OMI and EAP patients (27±7 mmHg vs 15±6 mmHg for OMI patients; 22±6 mmHg vs 12±7 mmHg for EAP patients). For PD, Tl uptake rate on Ex initial images was higher in Group 1 than Gorup 2 of both OMI and EAP patients (63±7% vs 55±9% for OMI patients; 72±7% vs 65±9% for EAP patients). Resting delayed images for OMI patients showed the highest Tl uptake rate in Group 1 (78±7%), followed by Group 2 (74±8%) and then Group 3 (41±10%). In the group of OMI patients, the incidence of akinetic or dyskinetic wall motion on left ventriculography was the highest in Group 3 (85.7%), followed by Group 2 (52.2%) and Group 1 (24.3%). OMI patients, as well as EAP patients, had lower PD on resting delayed images than EX delayed images. Thus, severer ischemia may be associated with stress and infarcted areas may not involve viable muscle when Tl PD is decreased on resting delayed images. (N.K.)

  16. Buffer Sizing in 802.11 Wireless Mesh Networks

    KAUST Repository

    Jamshaid, Kamran; Shihada, Basem; Xia, Li; Levis, Philip

    2011-01-01

    We analyze the problem of buffer sizing for TCP flows in 802.11-based Wireless Mesh Networks. Our objective is to maintain high network utilization while providing low queueing delays. The problem is complicated by the time-varying capacity of the wireless channel as well as the random access mechanism of 802.11 MAC protocol. While arbitrarily large buffers can maintain high network utilization, this results in large queueing delays. Such delays may affect TCP stability characteristics, and also increase queueing delays for other flows (including real-time flows) sharing the buffer. In this paper we propose sizing link buffers collectively for a set of nodes within mutual interference range called the 'collision domain'. We aim to provide a buffer just large enough to saturate the available capacity of the bottleneck collision domain that limits the carrying capacity of the network. This neighborhood buffer is distributed over multiple nodes that constitute the network bottleneck; a transmission by any of these nodes fully utilizes the available spectral resource for the duration of the transmission. We show that sizing routing buffers collectively for this bottleneck allows us to have small buffers (as low as 2 - 3 packets) at individual nodes without any significant loss in network utilization. We propose heuristics to determine these buffer sizes in WMNs. Our results show that we can reduce the end-to-end delays by 6× to 10× at the cost of losing roughly 5% of the network capacity achievable with large buffers.

  17. Buffer Sizing in 802.11 Wireless Mesh Networks

    KAUST Repository

    Jamshaid, Kamran

    2011-10-01

    We analyze the problem of buffer sizing for TCP flows in 802.11-based Wireless Mesh Networks. Our objective is to maintain high network utilization while providing low queueing delays. The problem is complicated by the time-varying capacity of the wireless channel as well as the random access mechanism of 802.11 MAC protocol. While arbitrarily large buffers can maintain high network utilization, this results in large queueing delays. Such delays may affect TCP stability characteristics, and also increase queueing delays for other flows (including real-time flows) sharing the buffer. In this paper we propose sizing link buffers collectively for a set of nodes within mutual interference range called the \\'collision domain\\'. We aim to provide a buffer just large enough to saturate the available capacity of the bottleneck collision domain that limits the carrying capacity of the network. This neighborhood buffer is distributed over multiple nodes that constitute the network bottleneck; a transmission by any of these nodes fully utilizes the available spectral resource for the duration of the transmission. We show that sizing routing buffers collectively for this bottleneck allows us to have small buffers (as low as 2 - 3 packets) at individual nodes without any significant loss in network utilization. We propose heuristics to determine these buffer sizes in WMNs. Our results show that we can reduce the end-to-end delays by 6× to 10× at the cost of losing roughly 5% of the network capacity achievable with large buffers.

  18. Desensitization to a whole egg by rush oral immunotherapy improves the quality of life of guardians: A multicenter, randomized, parallel-group, delayed-start design study.

    Science.gov (United States)

    Itoh-Nagato, Naoka; Inoue, Yuzaburo; Nagao, Mizuho; Fujisawa, Takao; Shimojo, Naoki; Iwata, Tsutomu

    2018-04-01

    Patients with food allergies and their families have a significantly reduced health-related quality of life (QOL). We performed a multicenter, randomized, parallel-group, delayed-start design study to clarify the efficacy and safety of rush oral immunotherapy (rOIT) and its impact on the participants' daily life and their guardians (UMIN000003943). Forty-five participants were randomly divided into an early-start group and a late-start group. The early-start group received rOIT for 3 months, while the late-start group continued the egg elimination diet (control). In the next stage, both groups received OIT until all participants had finished 12 months of maintenance OIT. The ratio of the participants in whom an increase of the TD was achieved in the first stage was significantly higher in the early-start group (87.0%), than in the late-start group (22.7%). The QOL of the guardians in the early-start group significantly improved after the first stage (65.2%), in comparison to the late-start group (31.8%). During 12 months of rOIT, the serum ovomucoid-specific IgE levels, the percentage of CD203c + basophils upon stimulation with egg white, and the wheal size to egg white were decreased, while the serum ovomucoid-specific IgG4 levels were increased. However, approximately 80% of the participants in the early-start group showed an allergic reaction during the first stage of the study, whereas none of the patients in the late-start group experienced an allergic reaction. rOIT induced desensitization to egg and thus improved the QOL of guardians; however, the participants experienced frequent allergic reactions due to the treatment. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  19. Emission, absorption and group delay of microwaves in the atmosphere in relation to water vapour content over the Indian subcontinent

    Science.gov (United States)

    Sen, A. K.; Gupta, A. K. D.; Karmakar, P. K.; Barman, S. D.; Bhattacharya, A. B.; Purkait, N.; Gupta, M. K. D.; Sehra, J. S.

    1985-01-01

    The advent of satellite communication for global coverage has apparently indicated a renewed interest in the studies of radio wave propagation through the atmosphere, in the VHF, UHF and microwave bands. The extensive measurements of atmosphere constituents, dynamics and radio meterological parameters during the Middle Atmosphere Program (MAP) have opened up further the possibilities of studying tropospheric radio wave propagation parameters, relevant to Earth/space link design. The three basic parameters of significance to radio propagation are thermal emission, absorption and group delay of the atmosphere, all of which are controlled largely by the water vapor content in the atmosphere, particular at microwave bands. As good emitters are also good absorbers, the atmospheric emission as well as the absorption attains a maximum at the frequency of 22.235 GHz, which is the peak of the water vapor line. The group delay is practically independent of frequency in the VHF, UHF and microwave bands. However, all three parameters exhibit a similar seasonal dependence originating presumably from the seasonal dependence of the water vapor content. Some of the interesting results obtained from analyses of radiosonde data over the Indian subcontinent collected by the India Meteorological Department is presented.

  20. Anteseden Dan Konsekuensi Audit Delay Pada Perusahaan Perbankan Perioda 2011-2014

    Directory of Open Access Journals (Sweden)

    Ronald Tehupuring

    2016-10-01

    Full Text Available Timeliness in financial reporting can contribute to efficient performance for the stock market because it can reduce the asymmetry information, mitigate insider trading, and improve the usefulness decision of information to stakeholders. There were inconsistencies in prior research and the case of delay submission on issuer financial statements to the Financial Service Authority.  There were 30 cases for each in 2013 and 2014. This study aimed to examine (1 the negative impact between the company size, profitability, leverage, and the auditor quality on audit delay; (2 the positive impact of audit delay on audit switching; and (3 the positive impact of audit delay and audit delay switching on audit quality in banking companies listed on the Stock Exchange 2011-2014 period. A purposive sampling method is used and as the sample, 30 companies are obtained in four years so the analyzed data was based on 120 observations. The data analysis technique used is multiple linear and logistic regression. Results showed that (1 the size of the company and leverage have no impact on audit delay, while the return on assets and the auditor quality have a negative impact and significantly related to audit delay; (2 audit delay has a positive impact and significantly related to audit switching; (3 audit delay has a positive impact and significantly related to audit quality, while audit switching has no impact on audit quality. This study has contributed in optimizing timeliness performance of financial information reporting, effectiveness and efficiency of audit time range so that general  information increased, and The implication for audit quality of financial statements become more reliable.

  1. Break-before-make CMOS inverter for power-efficient delay implementation.

    Science.gov (United States)

    Puhan, Janez; Raič, Dušan; Tuma, Tadej; Bűrmen, Árpád

    2014-01-01

    A modified static CMOS inverter with two inputs and two outputs is proposed to reduce short-circuit current in order to increment delay and reduce power overhead where slow operation is required. The circuit is based on bidirectional delay element connected in series with the PMOS and NMOS switching transistors. It provides differences in the dynamic response so that the direct-path current in the next stage is reduced. The switching transistors are never ON at the same time. Characteristics of various delay element implementations are presented and verified by circuit simulations. Global optimization procedure is used to obtain the most power-efficient transistor sizing. The performance of the modified CMOS inverter chain is compared to standard implementation for various delays. The energy (charge) per delay is reduced up to 40%. The use of the proposed delay element is demonstrated by implementing a low-power delay line and a leading-edge detector cell.

  2. CYLFUX, Fast Reactor Reactivity Transients Simulation in LWR by 2-D 2 Group Diffusion

    International Nuclear Information System (INIS)

    Schmidt, A.

    1973-01-01

    1 - Nature of physical problem solved: A 2-dimensional calculation of the 2-group, space-dependent neutron diffusion equations is performed in r-z geometry using an arbitrary number of groups of delayed neutron precursors. The program is designed to simulate fast reactivity excursions in light water reactors taking into account Doppler feedback via adiabatic heatup of fuel. Axial motions of control rods may be considered including scram action on option. 2 - Method of solution: The differential equations are solved at each time step by an explicit finite difference method using two time levels. The stationary distributions are obtained by using the same algorithm. 3 - Restrictions on the complexity of the problem: No restriction to the number of space points and delayed neutron energy groups besides the computer size

  3. Group selection on population size affects life-history patterns in the entomopathogenic nematode Steinernema carpocapsae.

    Science.gov (United States)

    Bashey, Farrah; Lively, Curtis M

    2009-05-01

    Selection is recognized to operate on multiple levels. In disease organisms, selection among hosts is thought to provide an important counterbalance to selection for faster growth within hosts. We performed three experiments, each selecting for a divergence in group size in the entomopathogenic nematode, Steinernema carpocapsae. These nematodes infect and kill insect larvae, reproduce inside the host carcass, and emerge as infective juveniles. We imposed selection on group size by selecting among hosts for either high or low numbers of emerging nematodes. Our goal was to determine whether this trait could respond to selection at the group level, and if so, to examine what other traits would evolve as correlated responses. One of the three experiments showed a significant response to group selection. In that experiment, the high-selected treatment consistently produced more emerging nematodes per host than the low-selected treatment. In addition, nematodes were larger and they emerged later from hosts in the low-selected lines. Despite small effective population sizes, the effects of inbreeding were small in this experiment. Thus, selection among hosts can be effective, leading to both a direct evolutionary response at the population level, as well as to correlated responses in populational and individual traits.

  4. Influence of social mixing and group size on skin lesions and mounting in organic entire male pigs

    DEFF Research Database (Denmark)

    Thomsen, Rikke; Edwards, Sandra A; Rousing, Tine

    2016-01-01

    in management procedures and production system might be needed. Elements from the organic pig production system might be beneficial in this aspect. The aim of this article is to investigate the effect of grouping strategy including social mixing and group size on levels of mounting behaviour and skin lesions...... at weaning. A second mixing occurred at insertion to fattening pens for pigs being regrouped. Counting of skin lesions (1348 or 1124 pigs) and registration of mounting behaviour (1434 or 1258 pigs) were done on two occasions during the experimental period. No interactive effects were found between social...... mixing and group size on either skin lesions or mounting frequency. Herd differences were found for both mounting frequency and number of skin lesions. No association between skin lesions and mounting were revealed. Social mixing and group size were shown as interacting effects with herds on mounting...

  5. Language Delay in 3-Year-Old Children With ADHD Symptoms.

    Science.gov (United States)

    Rohrer-Baumgartner, Nina; Zeiner, Pål; Eadie, Patricia; Egeland, Jens; Gustavson, Kristin; Reichborn-Kjennerud, Ted; Aase, Heidi

    2016-10-01

    Little is known about cognition in preschoolers with ADHD and language delay (LD). The objective was to investigate cognitive functions in preschoolers with ADHD symptoms and LD compared with children with ADHD symptoms only and to estimate the frequency of children with ADHD symptoms, co-occurring language delay, and delays on cognitive measures. Participants were recruited from the Norwegian Mother and Child Cohort Study. The teacher report of expressive language and the cognitive tests from 119 3-year-old children with parent reported ADHD symptoms and LD were compared with those of 258 children with ADHD symptoms only. The ADHD + LD group performed significantly worse than the ADHD group on most language-related measures. There were no differences between the groups on most nonverbal measures. Single measures had a limited potential of differentiating between the groups. ADHD symptoms and co-occurring LD in preschoolers were characterized by cognitive deficits associated with both disorders, not with global neurodevelopmental delay. © The Author(s) 2013.

  6. Delayed Face Recognition in Children and Adolescents with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Zahra Shahrivar

    2012-06-01

    Full Text Available Objective: Children with autism spectrum disorders (ASDs have great problems in social interactions including face recognition. There are many studies reporting deficits in face memory in individuals with ASDs. On the other hand, some studies indicate that this kind of memory is intact in this group. In the present study, delayed face recognition has been investigated in children and adolescents with ASDs compared to the age and sex matched typically developing group.Methods: In two sessions, Benton Facial Recognition Test was administered to 15 children and adolescents with ASDs (high functioning autism and Asperger syndrome and to 15 normal participants, ages 8-17 years. In the first condition, the long form of Benton Facial Recognition Test was used without any delay. In the second session, this test was administered with 15 seconds delay after one week. The reaction times and correct responses were measured in both conditions as the dependent variables.Results: Comparison of the reaction times and correct responses in the two groups revealed no significant difference in delayed and non-delayed conditions. Furthermore, no significant difference was observed between the two conditions in ASDs patients when comparing the variables. Although a significant correlation (p<0.05 was found between delayed and non-delayed conditions, it was not significant in the normal group. Moreover, data analysis revealed no significant difference between the two groups in the two conditions when the IQ was considered as covariate. Conclusion: In this study, it was found that the ability to recognize faces in simultaneous and delayed conditions is similar between adolescents with ASDs and their normal counterparts.

  7. Accelerating Smaller Cutbacks to Delay Larger Ones?

    DEFF Research Database (Denmark)

    Tepe, Markus; Vanhuysse, Pieter

    2012-01-01

    . Investigating both medium and large cutbacks in ageing welfare states, we test whether, in addition to conventional demographic and economic variables, political-institutional variables capturing partisanship (political ideology), electioneering (political cycle), and institutional constraints (political...... effects of unemployment and population aging: these socio-demographic variables tend to delay large-size cutbacks, but to accelerate medium-size cutbacks in pension generosity, possibly because they function as alarm bell signals urging policymakers to take still feasible incremental action through...

  8. Effects of blood glucose on delay discounting, food intake and counterregulation in lean and obese men.

    Science.gov (United States)

    Klement, Johanna; Kubera, Britta; Eggeling, Jonas; Rädel, Christin; Wagner, Christin; Park, Soyoung Q; Peters, Achim

    2018-03-01

    Delay discounting as a measure of impulsivity has been shown to be higher in obesity with an association of increased food intake. Moreover, obese humans showed a higher wanting for high-calorie food than lean men when blood glucose concentrations were low. First studies linking blood glucose levels to delay discounting yielded mixed results. We hypothesized that obese people - in comparison to lean men - have a relative lack of energy, especially when blood glucose levels are low, that results in higher levels of delay discounting, food intake and hormonal counterregulation. We investigated 20 lean and 20 obese healthy young men in a single-blind balanced cross-over design. With a standardized glucose clamp technique, subjects underwent a hypoglycemic state in one condition and a euglycemic state in the control condition. Regularly, blood was sampled for assessment of hormonal status, and questionnaires were filled out to assess delay discounting and symptom awareness. After normalizing blood glucose concentrations, subjects were free to eat from a standardized test buffet, followed by a snack test. Delay discounting was higher in obese than in lean men throughout experiments (p  0.1). Furthermore, the discounting performance did not correlate with food intake from the test buffet or snack test (p > 0.3). As a response to hypoglycemia, hormonal counterregulation was pronounced in both weight groups (p  0.5). Our data suggest that augmented delay discounting is a robust feature in obesity that is not linked to glucose levels or actual food intake. With our systematically controlled approach, combining performance in delay discounting with regard to distinct blood glucose levels, different weight groups, counterregulatory behavior and food intake, our results imply that delay discounting is not susceptible to fluctuations of blood glucose and do not support the assumption that a low body's energy content leads to increased impulsivity. Further

  9. The Effect of a Reconstruction Technique and Heart Rate in the Evaluation of Optimal Trigger Delay Using Multiphase Reconstruction

    International Nuclear Information System (INIS)

    Cho, Young Jun

    2008-01-01

    To evaluate the mean optimal trigger delays and the difference between the absolute delay and the relative delay as a function of heart rate, using multiphase reconstruction. A total of 30 patients consecutively underwent a 64-slice MDCT examination. Optimal trigger delays at four planes (the bifurcation of the left main coronary artery, aortic valve, mitral valve and cardiac apex) were measured using multiphase reconstruction based on the absolute and relative delay. For this reason, patients were divided into three groups according to heart rate (group I, < 65 bpm; group II, 65-74 bpm; group III, ≥ 75 bpm), and the mean optimal trigger delays and the difference between the absolute delay and the relative delay were evaluated at the four planes for each group. The mean optimal trigger delay for the relative delay and absolute delay ranged from 46% to 66% and from 327 to 700 msec, respectively. The differences in the mean optimal trigger delay using the relative and the absolute delay at the four planes were 1% and 4 msec (group I), 3% and 27 msec (group II), and 14% and 46 msec (group III). In group III, the difference of the mean optimal trigger delay based on the relative delay, increased significantly compared to the absolute delay (p = 0.040). For the patients analyzed, the results suggest that as the heart rate increased, the mean optimal trigger delays shifted from the mid-diastolic phase to the end-systolic phase and the differences in the mean optimal trigger delay at the four planes were significantly greater for the relative delay

  10. Delayed versus immediate pushing in second stage of labor.

    Science.gov (United States)

    Kelly, Mary; Johnson, Eileen; Lee, Vickie; Massey, Liz; Purser, Debbie; Ring, Karen; Sanderson, Stephanye; Styles, Juanita; Wood, Deb

    2010-01-01

    Comparison of two different methods for management of second stage of labor: immediate pushing at complete cervical dilation of 10 cm and delayed pushing 90 minutes after complete cervical dilation. This study was a randomized clinical trial in a labor and delivery unit of a not-for-profit community hospital. A sample of 44 nulliparous mothers with continuous epidural anesthesia were studied after random assignment to treatment groups. Subjects were managed with either immediate or delayed pushing during the second stage of labor at the time cervical dilation was complete. The primary outcome measure was the length of pushing during second stage of labor. Secondary outcomes included length of second stage of labor, maternal fatigue and perineal injuries, and fetal heart rate decelerations. Two-tailed, unpaired Student's t-tests and Chi-square analysis were used for data analysis. Level of significance was set at p pushing; N = 16 delayed pushing). The delayed pushing group had significantly shorter amount of time spent in pushing compared with the immediate pushing group (38.9 +/- 6.9 vs. 78.7 +/- 7.9 minutes, respectively, p = .002). Maternal fatigue scores, perineal injuries, and fetal heart rate decelerations were similar for both groups. Delaying pushing for up to 90 minutes after complete cervical dilation resulted in a significant decrease in the time mothers spent pushing without a significant increase in total time in second stage of labor.In clinical practice, healthcare providers sometimes resist delaying the onset of pushing after second stage of labor has begun because of a belief it will increase labor time. This study's finding of a 51% reduction in pushing time when mothers delay pushing for up to 90 minutes, with no significant increase in overall time for second stage of labor, disputes that concern.

  11. Is early cord clamping, delayed cord clamping or cord milking best?

    Science.gov (United States)

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2018-04-01

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  12. Interteaching: The Effects of Discussion Group Size on Undergraduate Student Performance and Preference

    Science.gov (United States)

    Gutierrez, Michael

    2017-01-01

    Interteaching is a college teaching method grounded in the principles of applied behavior analysis. Research on interteaching demonstrates that it improves academic performance, and students report greater satisfaction with interteaching as compared to traditional teaching styles. The current study investigates whether discussion group size, a…

  13. Investigation of delayed fission gas release

    International Nuclear Information System (INIS)

    Cayet, Nicolas

    1996-05-01

    The study of the fission gas release process in the high burnup rig IFA-562 has revealed a particular fuel behaviour: a delay in the fission gas release process. It appeared that an important release of gas was measured by the pressure transducers once the power had decreased, whereas, during steady-state operation, the pressure did not increase very much. After examinations, the gap size has been concluded to be the main parameter involving this delay. However the burnup could have been a potential factor, its role is mainly to close the gap by swelling. The observations of low burnup rods have shown the same delayed fission gas release, the gap being small by design and closed essentially by thermal expansion. The study of the kinetics has demonstrated the time-independency of the phenomenon. Thus the proposed mechanism driving this delayed fission gas release would involve three consecutives stages. During steady-state, the gas is released into the interlinkage network of grain boundary bubbles and cracks. Due to the closed gap, the gas is trapped in some void volumes, unable to escape the pellet. During power reduction, the gap and some old/new cracks open, immediately providing a path for the gas to the pressure transducers and explaining this delay in the fission gas release. (author)

  14. Desensitization in delayed drug hypersensitivity reactions -- an EAACI position paper of the Drug Allergy Interest Group.

    Science.gov (United States)

    Scherer, K; Brockow, K; Aberer, W; Gooi, J H C; Demoly, P; Romano, A; Schnyder, B; Whitaker, P; Cernadas, J S R; Bircher, A J

    2013-07-01

    Drug hypersensitivity may deprive patients of drug therapy, and occasionally no effective alternative treatment is available. Successful desensitization has been well documented in delayed drug hypersensitivity reactions. In certain situations, such as sulfonamide hypersensitivity in HIV-positive patients or hypersensitivity to antibiotics in patients with cystic fibrosis, published success rates reach 80%, and this procedure appears helpful for the patient management. A state of clinical tolerance may be achieved by the administration of increasing doses of the previously offending drug. However, in most cases, a pre-existent sensitization has not been proven by positive skin tests. Successful re-administration may have occurred in nonsensitized patients. A better understanding of the underlying mechanisms of desensitization is needed. Currently, desensitization in delayed hypersensitivity reactions is restricted to mild, uncomplicated exanthems and fixed drug eruptions. The published success rates vary depending on clinical manifestations, drugs, and applied protocols. Slower protocols tend to be more effective than rush protocols; however, underreporting of unsuccessful procedures is very probable. The decision to desensitize a patient must always be made on an individual basis, balancing risks and benefits. This paper reviews the literature and presents the expert experience of the Drug Hypersensitivity Interest Group of the European Academy of Allergy and Clinical Immunology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Finding determinants of audit delay by pooled OLS regression analysis

    Directory of Open Access Journals (Sweden)

    Tina Vuko

    2014-03-01

    Full Text Available The aim of this paper is to investigate determinants of audit delay. Audit delay is measured as the length of time (i.e. the number of calendar days from the fiscal year-end to the audit report date. It is important to understand factors that influence audit delay since it directly affects the timeliness of financial reporting. The research is conducted on a sample of Croatian listed companies, covering the period of four years (from 2008 to 2011. We use pooled OLS regression analysis, modelling audit delay as a function of the following explanatory variables: audit firm type, audit opinion, profitability, leverage, inventory and receivables to total assets, absolute value of total accruals, company size and audit committee existence. Our results indicate that audit committee existence, profitability and leverage are statistically significant determinants of audit delay in Croatia.

  16. "What time is my next meal?" delay-discounting individuals choose smaller portions under conditions of uncertainty.

    Science.gov (United States)

    Zimmerman, Annie R; Ferriday, Danielle; Davies, Sarah R; Martin, Ashley A; Rogers, Peter J; Mason, Alice; Brunstrom, Jeffrey M

    2017-09-01

    'Dietary' delay discounting is typically framed as a trade-off between immediate rewards and long-term health concerns. Our contention is that prospective thinking also occurs over shorter periods, and is engaged to select portion sizes based on the interval between meals (inter-meal interval; IMI). We sought to assess the extent to which the length of an IMI influences portion-size selection. We predicted that delay discounters would show 'IMI insensitivity' (relative lack of concern about hunger or fullness between meals). In particular, we were interested in participants' sensitivity to an uncertain IMI. We hypothesized that when meal times were uncertain, delay discounters would be less responsive and select smaller portion sizes. Participants (N = 90) selected portion sizes for lunch. In different trials, they were told to expect dinner at 5pm, 9pm, and either 5pm or 9pm (uncertain IMI). Individual differences in future-orientation were measured using a monetary delay-discounting task. Participants chose larger portions when the IMI was longer (p relationship between BMI and smaller portion selection in uncertainty (p < 0.05). This is the first study to report an association between delay discounting and IMI insensitivity. We reason that delay discounters selected smaller portions because they were less sensitive to the uncertain IMI, and overlooked concerns about potential future hunger. These findings are important because they illustrate that differences in discounting are expressed in short-term portion-size decisions and suggest that IMI insensitivity increases when meal timings are uncertain. Further research is needed to confirm whether these findings generalise to other populations. Copyright © 2017. Published by Elsevier Ltd.

  17. Factors influencing delay in the diagnosis of colorectal cancer: a study protocol

    International Nuclear Information System (INIS)

    Esteva, Magdalena; Ramos, Maria; Cabeza, Elena; Llobera, Joan; Ruiz, Amador; Pita, Salvador; Segura, Josep M; Cortés, Jose M; González-Lujan, Luis

    2007-01-01

    Colorectal cancer (CRC) is the second most frequent tumor in developed countries. Since survival from CRC depends mostly on disease stage at the time of diagnosis, individuals with symptoms or signs suspicious of CRC should be examined without delay. Many factors, however, intervene between symptom onset and diagnosis. This study was designed to: 1) Describe the diagnostic process of CRC from the onset of first symptoms to diagnosis and treatment. 2) Establish the time interval from initial symptoms to diagnosis and treatment, globally and considering patient's and doctors' delay, with the latter due to family physician and/or hospital services. 3) Identify the factors related to defined types of delay. 4) Assess the concordance between information included in primary health care and hospital clinical records regarding onset of first symptoms. Descriptive study, coordinated, with 5 participant groups of 5 different Spanish regions (Balearic Islands, Galicia, Catalunya, Aragón and Valencia Health Districts), with a total of 8 acute public hospitals and 140 primary care centers. Incident cases of CRC during the study period, as identified from pathology services at the involved hospitals. A sample size of 896 subjects has been estimated, 150 subjects for each participant group. Information will be collected through patient interviews and primary health care and hospital clinical records. Patient variables will include sociodemographic variables, family history of cancer, symptom perception, and confidence in the family physician; tumor variables will include tumor site, histological type, grade and stage; symptom variables will include date of onset, type and number of symptoms; health system variables will include number of patient contacts with family physician, type and content of the referral, hospital services attending the patient, diagnostic modalities and results; and delay intervals, including global delays and delays attributed to the patient

  18. Congestion control for vehicular delay tolerant network routing protocols

    OpenAIRE

    Oham, Chuka Finbars

    2014-01-01

    The Vehicular Delay Tolerant Network (VDTN) is a special and challenging type of the Delay Tolerant Network because of its high mobility, frequent disconnections and nodal congestion features. These challenging features make it prone to congestion which leads to a considerable amount of message drops in the network. To minimize the impact of congestion in the network, we designed and implemented the Congestion Aware Spray and Wait (CASaW) routing protocol. We varied the buffer sizes of the no...

  19. Robustness of unstable attractors in arbitrarily sized pulse-coupled networks with delay

    International Nuclear Information System (INIS)

    Broer, Henk; Efstathiou, Konstantinos; Subramanian, Easwar

    2008-01-01

    We consider arbitrarily large networks of pulse-coupled oscillators with non-zero delay where the coupling is given by the Mirollo–Strogatz function. We prove that such systems have unstable attractors (saddle periodic orbits whose stable set has non-empty interior) in an open parameter region for three or more oscillators. The evolution operator of the system can be discontinuous and we propose an improved model with continuous evolution operator

  20. early versus delayed induction of labour

    African Journals Online (AJOL)

    during labour versus 18 patients (52%) in the group that was induced .... (AMG) or a delayed induction group (DIG). Sealed .... Of the 7 CSs in the DIG, 3 were for fetal heart rate .... in mind that labour was never induced later than 48 hours.

  1. Assessment of Various Risk Factors for Success of Delayed and Immediate Loaded Dental Implants: A Retrospective Analysis.

    Science.gov (United States)

    Prasant, M C; Thukral, Rishi; Kumar, Sachin; Sadrani, Sannishth M; Baxi, Harsh; Shah, Aditi

    2016-10-01

    Ever since its introduction in 1977, a minimum of few months of period is required for osseointegration to take place after dental implant surgery. With the passage of time and advancements in the fields of dental implant, this healing period is getting smaller and smaller. Immediate loading of dental implants is becoming a very popular procedure in the recent time. Hence, we retrospectively analyzed the various risk factors for the failure of delayed and immediate loaded dental implants. In the present study, retrospective analysis of all the patients was done who underwent dental implant surgeries either by immediate loading procedure or by delayed loading procedures. All the patients were divided broadly into two groups with one group containing patients in which delayed loaded dental implants were placed while other consisted of patients in whom immediate loaded dental implants were placed. All the patients in whom follow-up records were missing and who had past medical history of any systemic diseases were excluded from the present study. Evaluation of associated possible risk factors was done by classifying the predictable factors as primary and secondary factors. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Kaplan-Meier survival analyses and chi-square test were used for assessment of level of significance. In delayed and immediate group of dental implants, mean age of the patients was 54.2 and 54.8 years respectively. Statistically significant results were obtained while comparing the clinical parameters of the dental implants in both the groups while demographic parameters showed nonsignificant correlation. Significant higher risk of dental implant failure is associated with immediate loaded dental implants. Tobacco smoking, shorter implant size, and other risk factors play a significant role in predicting the success and failure of dental implants. Delayed loaded dental implant placement should be preferred

  2. Prospective analysis of delayed colorectal post-polypectomy bleeding.

    Science.gov (United States)

    Park, Soo-Kyung; Seo, Jeong Yeon; Lee, Min-Gu; Yang, Hyo-Joon; Jung, Yoon Suk; Choi, Kyu Yong; Kim, Hungdai; Kim, Hyung Ook; Jung, Kyung Uk; Chun, Ho-Kyung; Park, Dong Il

    2018-01-17

    Although post-polypectomy bleeding is the most frequent complication after colonoscopic polypectomy, only few studies have investigated the incidence of bleeding prospectively. The aim of this study was to investigate the incidence of delayed post-polypectomy bleeding and its associated risk factors prospectively. Patients who underwent colonoscopic polypectomy at Kangbuk Samsung Hospital from January 2013 to December 2014 were prospectively enrolled in this study. Trained nurses contacted patients via telephone 7 and 30 days after polypectomy and completed a standardized questionnaire regarding the development of bleeding. Delayed post-polypectomy bleeding was categorized as minor or major and early or late bleeding. Major delayed bleeding was defined as a > 2-g/dL drop in the hemoglobin level, requiring hospitalization for control of bleeding or blood transfusion; late delayed bleeding was defined as bleeding occurring later than 24 h after polypectomy. A total of 8175 colonoscopic polypectomies were performed in 3887 patients. Overall, 133 (3.4%) patients developed delayed post-polypectomy bleeding. Among them, 90 (2.3%) and 43 (1.1%) patients developed minor and major delayed bleeding, respectively, and 39 (1.0%) patients developed late delayed bleeding. In the polyp-based multivariate analysis, young age ( 10 mm (OR 2.45; 95% CI 1.38-4.36) were significant risk factors for major delayed bleeding, while young age (< 50 years; OR 2.6; 95% CI 1.35-5.12) and immediate bleeding (OR 3.3; 95% CI 1.49-7.30) were significant risk factors for late delayed bleeding. Young age, aspirin use, polyp size, and immediate bleeding were found to be independent risk factors for delayed post-polypectomy bleeding.

  3. Delayed Consensus Problem for Single and Double Integrator Systems

    Directory of Open Access Journals (Sweden)

    Martín Velasco-Villa

    2015-01-01

    Full Text Available This work deals with the analysis of the consensus problem for networks of agents constituted by single and double integrator systems. It is assumed that the communication among agents is affected by a constant time-delay. Previous and numerous analysis of the problem shows that the maximum communication time-delay that can be introduced to the network without affecting the consensus of the group of the agents depends on the considered topology. In this work, a control scheme that is based on the estimation of future states of the agents and that allows increasing the magnitude of a possible time-delay affecting the communication channels is proposed. How the proposed delay compensation strategy is independent of the network topology in the sense that the maximum allowable time-delay that could be supported by the network depends on a design parameter and not on the maximum eigenvalue of the corresponding Laplacian matrix is shown. It is formally proven that, under the proposed prediction scheme, the consensus of the group can be achieved by improving the maximum time-delay bounds previously reported in the literature. Numerical simulations show the effectiveness of the proposed solution.

  4. Behavior Problems in Toddlers with and without Developmental Delays: Comparison of Treatment Outcomes

    Science.gov (United States)

    Holtz, Casey A.; Carrasco, Jennifer M.; Mattek, Ryan J.; Fox, Robert A.

    2009-01-01

    The purpose of this study is to examine the effectiveness of an in-home parent management program for toddlers with behavior problems and developmental delays by comparing outcomes for a group of toddlers with developmental delays (n = 27) and a group of toddlers without developmental delays (n = 27). The majority of children lived in single…

  5. Early and delayed results of radiotherapy and multimodality therapy of spinal hemangiomas

    International Nuclear Information System (INIS)

    Morozov, A.I.; Neretin, V.Ya.; Korshunov, A.I.; Nikolaeva, S.N.; Balkanov, A.S.; Marchenko, V.A.

    1988-01-01

    The authors described the results of therapy of 74 spinal hemangioma patients. The patients were divided into 2 groups: 1 - radiotherapy only; 2 - radiotherapy following surgical intervention for enhanced symptoms of spinal compression. γ-beam therapy was given 5 times a week at a single dose of 0.8-1.2 Gy. An integral dose delivered to the cervical spine was 26-32 Gy, to the thoracic spine 28-30 Gy, to the lumber spine - 30-34 Gy. Field sizes varied from 3x4 to 3x12 cm depending on lesion spreading. Therapy also included traction on a special platform bed. An analysis of delayed therapeutic results (from 3 to 13 yrs.) has shown that clinical convalescence with regained working capacity in the 1st group (40 patients) was observed in 21 patients, in the 2nd group (34 patients) - in 5 patients only. Partial functional restoration was observed in both groups (19 patients in each group). The therapy applied was ineffective in 10 patients of the 2nd group

  6. Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides.

    Science.gov (United States)

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders

    2016-10-01

    The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012-2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1-2 teeth were included in this study. Pre- and postsurgical images were superimposed to evaluate deviations at the crest, apex, and angle. A total of 40 implants placed in 29 patients were included in this study. The overall mean deviations measured at the crest, apex, and angle were 0.86 mm, 1.25 mm, and 3.79°, respectively. The means for the immediate group deviations were: crest = 0.85 mm, apex = 1.10, and angle = 3.49°. The means for the delayed group deviations were: crest = 0.88 mm, apex = 1.59, and angle = 4.29°. No statistically significant difference was found at the crest and angle; however, there was a statistically significant difference between the immediate and delayed group at the apex, with the immediate group presenting more accurate placements at the apical point than the delayed group. CAD/CAM surgical guides can be reliable tools to accurately place implants immediately and/or in a delayed fashion. No statistically significant differences were found between the delayed and the immediate group at the crest and angle, however apical position was more accurate in the immediate group.

  7. Energy dependence of relative abundances and periods of separate groups of delayed neutrons at neutron induced fission of 239Pu in a range of neutrons energies 0.37 - 5 MeV

    International Nuclear Information System (INIS)

    Roschenko, V.A.; Piksaikin, V.M.; Kazakov, L.E.; Isaev, S.G.; Korolev, G.G.; Tarasko, M.Z.; Tertychnyi, R.G.

    2001-01-01

    The fundamental role of delayed neutrons in behavior, control and safety of reactors is well known today. Delayed neutron data are of great interest not only for reactor physics but also for nuclear fission physics and astrophysics. The purpose of the present work was the measurement of energy dependence of delayed neutrons (DN) group parameters at fission of nuclei 239 Pu in a range of energies of primary neutrons from 0.37 up to 5 MeV. The measurements were executed on installation designed on the basis of the electrostatic accelerator of KG - 2.5 SSC RF IPPE. The data are obtained in 6-group representation. It is shown, that there is a significant energy dependence of DN group parameters in a range of primary neutrons energies from thermal meanings up to 5 MeV, which is expressed in reduction of the average half-life of nuclei of the DN precursors on 10 %. The data, received in the present work, can be used at creation of a set of group constants for reactors with an intermediate spectrum of neutrons. (authors)

  8. The reduced local lymph node assay: the impact of group size.

    Science.gov (United States)

    Ryan, Cindy A; Chaney, Joel G; Kern, Petra S; Patlewicz, Grace Y; Basketter, David A; Betts, Catherine J; Dearman, Rebecca J; Kimber, Ian; Gerberick, G Frank

    2008-05-01

    The local lymph node assay (LLNA) is a skin sensitization test that provides animal welfare benefits. To reduce animal usage further, a modified version (rLLNA) was proposed. Conducting the rLLNA as a screening test with a single high dose group and vehicle control differentiated accurately between skin sensitizers and non-sensitizers. This study examined whether a reduction in animal number/group is feasible. Historical data were utilized to examine the impact of conducting the rLLNA with two mice/group. To assess the effect on the stimulation index (SI) 41 datasets with individual animal data derived using five mice/group were analysed. SIs were calculated on all possible combinations of two control and two high dose group disintegrations per minute (dpm) values. For 25 of 33 sensitizer datasets, > 96% of possible dpm combinations resulted in a calculated SI > 3. The lowest percentages of positive SIs were observed with weak allergens when, in the standard LLNA, the mean SIs would have been nearer to the threshold value of 3. The results indicate that moderate, strong and extreme allergens are more likely than weak allergens to be identified as sensitizers when group sizes of two mice are used within the rLLNA. It is concluded that a rLLNA with two mice/group would display decreased sensitivity and is inappropriate for use in hazard identification. Copyright (c) 2007 John Wiley & Sons, Ltd.

  9. Pseudotumoral delayed cerebral radionecrosis

    International Nuclear Information System (INIS)

    Ciaudo-Lacroix, C.; Lapresle, J.

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. γEG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed [fr

  10. Pseudotumoral delayed cerebral radionecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ciaudo-Lacroix, C; Lapresle, J [Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France)

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  11. The use of 65Zn for estimating group size of brown hyaenas Hyaena ...

    African Journals Online (AJOL)

    MacDonald 1983), is influenced by the quality of resources within a territory (Mills 1982). Group size is, however, difficult to determine accurately using routine methods (i.e., direct counts and mark recapture techniques) owing to the shy, elusive and nocturnal habits of brown hyaenas and the physiognomic characteristics of ...

  12. The influence of delaying judgments of learning on metacognitive accuracy: a meta-analytic review.

    Science.gov (United States)

    Rhodes, Matthew G; Tauber, Sarah K

    2011-01-01

    Many studies have examined the accuracy of predictions of future memory performance solicited through judgments of learning (JOLs). Among the most robust findings in this literature is that delaying predictions serves to substantially increase the relative accuracy of JOLs compared with soliciting JOLs immediately after study, a finding termed the delayed JOL effect. The meta-analyses reported in the current study examined the predominant theoretical accounts as well as potential moderators of the delayed JOL effect. The first meta-analysis examined the relative accuracy of delayed compared with immediate JOLs across 4,554 participants (112 effect sizes) through gamma correlations between JOLs and memory accuracy. Those data showed that delaying JOLs leads to robust benefits to relative accuracy (g = 0.93). The second meta-analysis examined memory performance for delayed compared with immediate JOLs across 3,807 participants (98 effect sizes). Those data showed that delayed JOLs result in a modest but reliable benefit for memory performance relative to immediate JOLs (g = 0.08). Findings from these meta-analyses are well accommodated by theories suggesting that delayed JOL accuracy reflects access to more diagnostic information from long-term memory rather than being a by-product of a retrieval opportunity. However, these data also suggest that theories proposing that the delayed JOL effect results from a memorial benefit or the match between the cues available for JOLs and those available at test may also provide viable explanatory mechanisms necessary for a comprehensive account.

  13. Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties

    Science.gov (United States)

    Kang, Jongeun; Lee, Hyunseung; Kim, Young-Nam; Yeom, Areum; Jeong, Heejeong; Lim, Yong Taik; Hong, Kwan Soo

    2013-09-01

    Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe2O4 MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T2 relaxivities ( r 2) at 4.7 T and room temperature in the range of 60 to 300 mM-1s-1, depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe2O4 MNPs could be used as initial base cores of MRI T2 CAs, with almost unique T2 relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis.

  14. Social Reinforcement Delays in Free-Flying Honey Bees (Apis mellifera L.)

    Science.gov (United States)

    Craig, David Philip Arthur; Grice, James W.; Varnon, Chris A.; Gibson, B.; Sokolowski, Michel B. C.; Abramson, Charles I.

    2012-01-01

    Free-flying honey bees (Apis mellifera L.) reactions were observed when presented with varying schedules of post-reinforcement delays of 0 s, 300 s, or 600 s. We measured inter-visit-interval, response length, inter-response-time, and response rate. Honey bees exposed to these post-reinforcement delay intervals exhibit one of several patterns compared to groups not encountering delays, and had longer inter-visit-intervals. We observed no group differences in inter-response time. Honey bees with higher response rates tended to not finish the experiment. The removal of the delay intervals increased response rates for those subjects that completed the trials. PMID:23056425

  15. Mode Switching for the Multi-Antenna Broadcast Channel Based on Delay and Channel Quantization

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2009-01-01

    Full Text Available Imperfect channel state information degrades the performance of multiple-input multiple-output (MIMO communications; its effects on single-user (SU and multiuser (MU MIMO transmissions are quite different. In particular, MU-MIMO suffers from residual interuser interference due to imperfect channel state information while SU-MIMO only suffers from a power loss. This paper compares the throughput loss of both SU and MU-MIMO in the broadcast channel due to delay and channel quantization. Accurate closed-form approximations are derived for achievable rates for both SU and MU-MIMO. It is shown that SU-MIMO is relatively robust to delayed and quantized channel information, while MU-MIMO with zero-forcing precoding loses its spatial multiplexing gain with a fixed delay or fixed codebook size. Based on derived achievable rates, a mode switching algorithm is proposed, which switches between SU and MU-MIMO modes to improve the spectral efficiency based on average signal-to-noise ratio (SNR, normalized Doppler frequency, and the channel quantization codebook size. The operating regions for SU and MU modes with different delays and codebook sizes are determined, and they can be used to select the preferred mode. It is shown that the MU mode is active only when the normalized Doppler frequency is very small, and the codebook size is large.

  16. Polidocanol injection for chemical delay and its effect on the survival of rat dorsal skin flaps.

    Science.gov (United States)

    Menevşe, Gülsüm Tetik; TeomanTellioglu, Ali; Altuntas, Nurgül; Cömert, Ayhan; Tekdemir, Ibrahim

    2014-06-01

    Surgical delay is an invasive method requiring a two-stage surgical procedure. Hence, methods that may serve as an alternative to surgical delay have become the focus of interest of research studies. From a conceptual view, any technique that interrupts the blood flow along the edges of a proposed flap will render the flap ischemic and induce a delay phenomenon. Polidocanol (Aethoxysklerol(®)-Kreussler) was initially used as a local anesthetic. Nowadays, it has been used as a sclerosing agent to treat telangiectasias and varicose veins. The aim of this experimental study was to investigate the effects of polidocanol injected around the periphery of a random flap as a sclerosing agent on flap delay and survival in a random flap model. A preliminary histopathologic study was performed on two rats to evaluate the sclerosing effect and distribution of polidocanol injection. After the preliminary study, the main study was carried out with three groups: group 1: dorsal flap (n = 10); group 2: dorsal flap + surgical delay (n = 10), group 3: dorsal flap + chemical delay (n = 10). Tissue samples obtained from the flap and injection area revealed destruction of intradermal vessels. The area affected with sclerosis was limited to 0.1 cm beyond the injection site. Mean viable flap areas were 52.1 ± 4.38% (44.0-58.2) in group 1, 64.8 ± 8.92% (57.2-89.2) in group 2, and 71.8 ± 5.18% (64.0-84.0) in group 3. A statistically highly significant difference was found between the surgical delay and chemical delay groups versus the group without delay (p injection around the dorsal flap in the rat is a safe and easy method for nonsurgical delay. The results have shown a flap survival benefit that is superior to controls and equivalent to surgical delay. The clinical application of polidocanol, already in clinical practice for occlusal of telangiectasias, for surgical delay appears feasible. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons

  17. Spectra and pseudospectra of neutral delay differential equations with application to real-time substructuring

    NARCIS (Netherlands)

    Green, K.; Wagenknecht, T.

    2010-01-01

    This paper deals with the computation of pseudospectra of neutral delay differential equations (NDDEs) with fixed finite delays. This method provides information on the sensitivity of eigenvalues of the system under perturbations of a given size, allowing one to analyse uncertainties in, for

  18. Contralateral delay activity tracks the influence of Gestalt grouping principles on active visual working memory representations.

    Science.gov (United States)

    Peterson, Dwight J; Gözenman, Filiz; Arciniega, Hector; Berryhill, Marian E

    2015-10-01

    Recent studies have demonstrated that factors influencing perception, such as Gestalt grouping cues, can influence the storage of information in visual working memory (VWM). In some cases, stationary cues, such as stimulus similarity, lead to superior VWM performance. However, the neural correlates underlying these benefits to VWM performance remain unclear. One neural index, the contralateral delay activity (CDA), is an event-related potential that shows increased amplitude according to the number of items held in VWM and asymptotes at an individual's VWM capacity limit. Here, we applied the CDA to determine whether previously reported behavioral benefits supplied by similarity, proximity, and uniform connectedness were reflected as a neural savings such that the CDA amplitude was reduced when these cues were present. We implemented VWM change-detection tasks with arrays including similarity and proximity (Experiment 1); uniform connectedness (Experiments 2a and 2b); and similarity/proximity and uniform connectedness (Experiment 3). The results indicated that when there was a behavioral benefit to VWM, this was echoed by a reduction in CDA amplitude, which suggests more efficient processing. However, not all perceptual grouping cues provided a VWM benefit in the same measure (e.g., accuracy) or of the same magnitude. We also found unexpected interactions between cues. We observed a mixed bag of effects, suggesting that these powerful perceptual grouping benefits are not as predictable in VWM. The current findings indicate that when grouping cues produce behavioral benefits, there is a parallel reduction in the neural resources required to maintain grouped items within VWM.

  19. Increasing Social Behaviors in Young Children with Social-Communication Delays in a Group Arrangement in Preschool

    Science.gov (United States)

    Lane, Justin D.; Gast, David L.; Ledford, Jennifer R.; Shepley, Collin

    2017-01-01

    Young children with disabilities are less likely to display age-appropriate social behaviors than same-age peers with typical social development, especially children who display social-communication delays. In this study, two concurrently operating single case designs were used to evaluate the use of progressive time delay (PTD) to teach children…

  20. Usefulness and safety of early against delayed oral intake after appendectomy

    International Nuclear Information System (INIS)

    Sheikh, I.A.; Taj, R.U.

    2015-01-01

    Objective: To evaluate the usefulness and safety of early versus late oral intake after appendectomy. Study Design: Randomized clinical trial. Place and Duration of Study: Combined Military Hospital Multan from August 2008 to February 2009. Material and Methods: One hundred patients with uncomplicated acute appendicitis, undergoing appendectomy under general anesthesia were included in the study and randomly divided into two equal groups. Early oral intake group (group A) was allowed fluids, when patients were out of effects of general anesthesia. Delayed fed (group B) was started oral fluids, on appearance of normal bowel sounds or passage of flatus. Low residue solid diet was started, after tolerance of oral fluids, in both groups. Results: Early oral intake resulted in start of solid diet earlier by average 9 hours; these patients had normal bowel sounds, and passed flatus, earlier, after 4 hours and 5 hours as compared to late feeding group. Six (12%) patients had mild ileus in early fed group whereas 4(8%) patients in delayed fed group had mild ileus. Thirty eight (76%) early fed patients were very satisfied, as compared to 29 (58%) delayed fed patients. The hospital stay was prolonged by 2 days in delayed fed group. Conclusion: Early oral feeding implemented after appendectomy is safe and effective, with a shortened hospital stay as the primary benefit in patients after appendectomy. (author)

  1. Construction delays causing risks on time and cost - a critical review

    Directory of Open Access Journals (Sweden)

    Chidambaram Ramanathan

    2012-02-01

    Full Text Available There is an increase in the number of construction projects experiencing extensive delays leading to exceeding initial time and cost budget.  This paper reviews 41 studies around the world which surveyed the delay factors and classified them into Groups.  The main purpose of this paper is to review literature, each of which have categorized the causes that are responsible for time delays and cost overrun in projects. The collected list has 113 causes for delays categorized in to 18 different groups.  Most of the researches have analysed the responses from the Questionnaire survey.    The collected data are used to rank the problem.  The data are further used to investigate and analyse Important Index, Frequency Index, Severity Index, Relative Important Index, Relative Importance Weight, Weighted Average, Mean, Standard Deviation and Variance.  The collective comparison has revealed that the ranking given by all the researchers is not the same.  Further each and every study has different rank ratings for the different group of the delays.  This review paper attempts to provide an updated compilation of the earlier studies on ranking of the delay causers, which are never similar and constant for universal projects.  It is concluded that a separate study is required for identifying the factors causing delay for projects operated in Sabah, East Malaysia.

  2. Nest Digging by Leaf-Cutting Ants: Effect of Group Size and Functional Structures

    Directory of Open Access Journals (Sweden)

    Roberto da Silva Camargo

    2012-01-01

    Full Text Available Leaf-cutting ant workers dig underground chambers, for housing their symbiotic fungus, interconnected by a vast quantity of tunnels whose function is to permit the entrance of food (leaves, gaseous exchanges, and movement of workers, offspring, and the queen. Digging is a task executed by a group of workers, but little is known about the group effect and group-constructed functional structures. Thus, we analyzed the structures formed by worker groups (5, 10, 20, and 40 individuals of the leaf-cutting ant, Atta sexdens rubropilosa, for 2 days of excavation. The digging arena was the same for the 4 groups, with each group corresponding to a different density. Our results verified a pattern of tunneling by the workers, but no chamber was constructed. The group effect is well known, since the 40-worker group dug significantly more than the groups of 5, 10, and 20. These groups did not differ statistically from each other. Analysis of load/worker verified that workers of the smallest group carried the greatest load. Our paper demonstrates the group effect on the digging of nests, namely, that excavation is proportional to group size, but without emergence of a functional structure such as a chamber.

  3. Delayed diagnosis of sarcoidosis is common in Brazil

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    Mauri Monteiro Rodrigues

    2013-09-01

    Full Text Available OBJECTIVE: To determine the frequency of and the factors related to delayed diagnosis of sarcoidosis in Brazil. METHODS: We evaluated patients with a biopsy-proven diagnosis of sarcoidosis, using a questionnaire that addressed the following: time since symptom onset and since the first medical visit; and the number and specialty of the physicians visited. We divided the patients by the timeliness of the diagnosis-timely (< 6 months and delayed (≥ 6 months-comparing the two groups in terms of systemic and pulmonary symptoms; extrathoracic involvement; spirometric data; radiological staging; level of education; income; and tuberculosis (diagnosis and treatment. RESULTS: We evaluated 100 patients. The median number of physicians consulted was 3 (range, 1-14. In 11 cases, sarcoidosis was diagnosed at the first visit. In 54, the first physician seen was a general practitioner. The diagnosis of sarcoidosis was timely in 41 patients and delayed in 59. The groups did not differ in terms of gender; race; type of health insurance; level of education; income; respiratory/systemic symptoms; extrathoracic involvement; and radiological staging. In the delayed diagnosis group, FVC was lower (80.3 ± 20.4% vs. 90.5 ± 17.1%; p = 0.010, as was FEV1 (77.3 ± 19.9% vs. 86.4 ± 19.5%; p = 0.024, misdiagnosis with and treatment for tuberculosis (≥ 3 months also being more common (24% vs. 7%, p = 0.032, and 20% vs. 0%; p = 0.002, respectively. CONCLUSIONS: The diagnosis of sarcoidosis is often delayed, even when the imaging is suggestive of sarcoidosis. Delayed diagnosis is associated with impaired lung function at the time of diagnosis. Many sarcoidosis patients are misdiagnosed with and treated for tuberculosis.

  4. Impulsive Choice, Alcohol Consumption, and Pre-Exposure to Delayed Rewards: II. Potential Mechanisms

    Science.gov (United States)

    Stein, Jeffrey S.; Renda, C. Renee; Hinnenkamp, Jay E.; Madden, Gregory J.

    2014-01-01

    In a prior study (Stein et al., 2013), we reported that rats pre-exposed to delayed rewards made fewer impulsive choices, but consumed more alcohol (12% wt/vol), than rats pre-exposed to immediate rewards. To understand the mechanisms that produced these findings, we again pre-exposed rats to either delayed (17.5 s; n = 32) or immediate (n = 30) rewards. In post-tests, delay-exposed rats made significantly fewer impulsive choices at both 15- and 30-s delays to a larger, later food reward than the immediacy-exposed comparison group. Behavior in an open-field test provided little evidence of differential stress exposure between groups. Further, consumption of either 12% alcohol or isocaloric sucrose in subsequent tests did not differ between groups. Because Stein et al. introduced alcohol concentration gradually (3–12%), we speculate that their group differences in 12% alcohol consumption were not determined by alcohol’s pharmacological effects, but by another variable (e.g., taste) that was preserved as an artifact from lower concentrations. We conclude that pre-exposure to delayed rewards generalizes beyond the pre-exposure delay; however, this same experimental variable does not robustly influence alcohol consumption. PMID:25418607

  5. Corporate Attributes and Audit Delay in Emerging Markets: Empirical Evidence from Nigeria

    Directory of Open Access Journals (Sweden)

    Afensimi Elijah

    2015-03-01

    Full Text Available The broad objective of the study was to examine the determinants of audit report lag in the Nigerian context. Specifically, the study examined the effects of the following factors on Audit fees; Audit firm type, Leverage, Return on equity, Firm size, subsidiaries and Year-end. The panel research design was used for the study. The data was sourced from the annual reports of all financial companies quoted on the floor of the Nigerian stock exchange. The method of data analysis utilized in the study is the panel data estimation techniques (pooled, fixed and random effects regression. In line with the study objectives, the finding reveals that (i Company size has no significant positive impact on audit delay. (ii Firm’s financial performance has a significant impact on Audit delay. (iii Audit firm type (big 4 and non-big 4 has a significant impact on Audit delay. (iv Leverage has no significant impact on Audit delay and (v Number of subsidiaries has a significant impact on Audit delay and (vi Financial year end has no significant impact on Audit delay. The recommendation is that in achieving the objective of making the financial statements readily available for making timely decisions, the Nigerian stock exchange, Securities and Exchange Commission, the Financial Reporting Council, the Central Bank of Nigeria and other regulatory bodies should put in place measures to ensure strict compliance with 3 months window for financial reports preparation and presentation.

  6. Individualized behavioral assessments and maternal ratings of mastery motivation in mental age-matched toddlers with and without motor delay.

    Science.gov (United States)

    Wang, Pei-Jung; Morgan, George A; Hwang, Ai-Wen; Liao, Hua-Fang

    2013-01-01

    Mastery motivation is a precursor of future developmental outcomes. Evidence about whether toddlers with motor delay have lower mastery motivation is inconclusive. The purpose of this study was to examine differences between mental age-matched toddlers with and without motor delay on various mastery motivation indicators. A mental age- and sex-matched case-control study was performed. Twenty-two children with motor delay, aged 23 to 47 months, and 22 children who were developing typically, aged 15 to 29 months, were recruited. Persistence and mastery pleasure were measured with behavioral tasks that were moderately challenging for each child and with maternal ratings using the Dimensions of Mastery Questionnaire (DMQ). The DMQ was rated by each child's mother based on her perception of her child's motivation. Two types of structured tasks (a puzzle and a cause-effect toy selected to be moderately challenging for each child) were administered in a laboratory setting and recorded on videos. Paired t tests or Wilcoxon signed rank tests were used to examine group differences in persistence and mastery pleasure (α=.007, 2-tailed). Children with motor delay were rated lower on DMQ persistence than the typically developing group, but they did not show significantly lower persistence on the structured tasks. There were no significant differences in mastery pleasure between the 2 groups on either measure. Large within-sample variability on the tasks and small sample size makes subgroup analysis (eg, different severities) difficult. Toddlers with motor delay did not show lower persistence and pleasure when given tasks that were moderately challenging; however, their mothers tended to view them as having lower motivation. Clinicians and parents should provide appropriately challenging tasks to increase children's success and motivation.

  7. Heterogeneity of time delays determines synchronization of coupled oscillators.

    Science.gov (United States)

    Petkoski, Spase; Spiegler, Andreas; Proix, Timothée; Aram, Parham; Temprado, Jean-Jacques; Jirsa, Viktor K

    2016-07-01

    Network couplings of oscillatory large-scale systems, such as the brain, have a space-time structure composed of connection strengths and signal transmission delays. We provide a theoretical framework, which allows treating the spatial distribution of time delays with regard to synchronization, by decomposing it into patterns and therefore reducing the stability analysis into the tractable problem of a finite set of delay-coupled differential equations. We analyze delay-structured networks of phase oscillators and we find that, depending on the heterogeneity of the delays, the oscillators group in phase-shifted, anti-phase, steady, and non-stationary clusters, and analytically compute their stability boundaries. These results find direct application in the study of brain oscillations.

  8. Steep Delay Discounting and Addictive Behavior: A Meta-Analysis of Continuous Associations

    Science.gov (United States)

    Amlung, Michael; Vedelago, Lana; Acker, John; Balodis, Iris; MacKillop, James

    2016-01-01

    Aims To synthesize continuous associations between delayed reward discounting (DRD) and both addiction severity and quantity-frequency (QF); to examine moderators of these relationships; and to investigate publication bias. Methods Meta-analysis of published studies examining continuous associations between DRD and addictive behaviors. Published, peer-reviewed studies on addictive behaviors (alcohol, tobacco, cannabis, stimulants, opiates, and gambling) were identified via PubMed, MEDLINE, and PsycInfo. Studies were restricted to DRD measures of monetary gains. Random effects meta-analysis was conducted using Pearson’s r as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger’s tests, meta-regression of publication year and effect size, and imputation of missing studies. Results The primary meta-analysis revealed a small magnitude effect size that was highly significant (r = 0.14, p addictive behavior (p = 0.30) or DRD assessment (p = 0.90). Indices of publication bias suggested a modest impact of unpublished findings. Conclusions Delayed reward discounting is robustly associated with continuous measures of addiction severity and quantity-frequency. This relation is generally robust across type of addictive behavior and delayed reward discounting assessment modality. PMID:27450931

  9. Development of a statistically based access delay timeline methodology.

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, W. Gary; Robinson, David Gerald; Wyss, Gregory Dane; Hendrickson, Stacey M. Langfitt

    2013-02-01

    The charter for adversarial delay is to hinder access to critical resources through the use of physical systems increasing an adversarys task time. The traditional method for characterizing access delay has been a simple model focused on accumulating times required to complete each task with little regard to uncertainty, complexity, or decreased efficiency associated with multiple sequential tasks or stress. The delay associated with any given barrier or path is further discounted to worst-case, and often unrealistic, times based on a high-level adversary, resulting in a highly conservative calculation of total delay. This leads to delay systems that require significant funding and personnel resources in order to defend against the assumed threat, which for many sites and applications becomes cost prohibitive. A new methodology has been developed that considers the uncertainties inherent in the problem to develop a realistic timeline distribution for a given adversary path. This new methodology incorporates advanced Bayesian statistical theory and methodologies, taking into account small sample size, expert judgment, human factors and threat uncertainty. The result is an algorithm that can calculate a probability distribution function of delay times directly related to system risk. Through further analysis, the access delay analyst or end user can use the results in making informed decisions while weighing benefits against risks, ultimately resulting in greater system effectiveness with lower cost.

  10. Influence of prey dispersion on territory and group size of African lions: a test of the resource dispersion hypothesis.

    Science.gov (United States)

    Valeix, Marion; Loveridge, Andrew J; MacDonald, David W

    2012-11-01

    Empirical tests of the resource dispersion hypothesis (RDH), a theory to explain group living based on resource heterogeneity, have been complicated by the fact that resource patch dispersion and richness have proved difficult to define and measure in natural systems. Here, we studied the ecology of African lions Panthera leo in Hwange National Park, Zimbabwe, where waterholes are prey hotspots, and where dispersion of water sources and abundance of prey at these water sources are quantifiable. We combined a 10-year data set from GPS-collared lions for which information of group composition was available concurrently with data for herbivore abundance at waterholes. The distance between two neighboring waterholes was a strong determinant of lion home range size, which provides strong support for the RDH prediction that territory size increases as resource patches are more dispersed in the landscape. The mean number of herbivore herds using a waterhole, a good proxy of patch richness, determined the maximum lion group biomass an area can support. This finding suggests that patch richness sets a maximum ceiling on lion group size. This study demonstrates that landscape ecology is a major driver of ranging behavior and suggests that aspects of resource dispersion limit group sizes.

  11. Timing matters: The impact of immediate and delayed feedback on artificial language learning

    Directory of Open Access Journals (Sweden)

    Bertram Opitz

    2011-02-01

    Full Text Available In the present experiment, we used event-related potentials (ERP to investigate the role of immediate and delayed feedback in an artificial grammar learning task. Two groups of participants were engaged in classifying non-word strings according to an underlying rule system, not known to the participants. Visual feedback was provided after each classification either immediately or with a short delay of one second. Both groups were able to learn the artificial grammar system as indicated by an increase in classification performance. However, the gain in performance was significantly larger for the group receiving immediate feedback as compared to the group receiving delayed feedback. Learning was accompanied by an increase in P300 activity in the ERP for delayed as compared to immediate feedback. Irrespective of feedback delay, both groups exhibited learning related decreases in the feedback-related positivity (FRP elicited by positive feedback only. The feedback-related negativity (FRN, however, remained constant over the course of learning. These results suggest, first, that delayed feedback is less effective for artificial grammar learning as task requirements are very demanding, and second, that the FRP elicited by positive prediction errors decreases with learning while the FRN to negative prediction errors is elicited in an all-or-none fashion by negative feedback throughout the entire experiment.

  12. Optimal Joint Expected Delay Forwarding in Delay Tolerant Networks

    OpenAIRE

    Jia Xu; Xin Feng; Wen Jun Yang; Ru Chuan Wang; Bing Qing Han

    2013-01-01

    Multicopy forwarding schemes have been employed in delay tolerant network (DTN) to improve the delivery delay and delivery rate. Much effort has been focused on reducing the routing cost while retaining high performance. This paper aims to provide an optimal joint expected delay forwarding (OJEDF) protocol which minimizes the expected delay while satisfying a certain constant on the number of forwardings per message. We propose a comprehensive forwarding metric called joint expected delay (JE...

  13. Physician peer group characteristics and timeliness of breast cancer surgery.

    Science.gov (United States)

    Bachand, Jacqueline; Soulos, Pamela R; Herrin, Jeph; Pollack, Craig E; Xu, Xiao; Ma, Xiaomei; Gross, Cary P

    2018-04-24

    Little is known about how the structure of interdisciplinary groups of physicians affects the timeliness of breast cancer surgery their patients receive. We used social network methods to examine variation in surgical delay across physician peer groups and the association of this delay with group characteristics. We used linked Surveillance, Epidemiology, and End Results-Medicare data to construct physician peer groups based on shared breast cancer patients. We used hierarchical generalized linear models to examine the association of three group characteristics, patient racial composition, provider density (the ratio of potential vs. actual connections between physicians), and provider transitivity (clustering of providers within groups), with delayed surgery. The study sample included 8338 women with breast cancer in 157 physician peer groups. Surgical delay varied widely across physician peer groups (interquartile range 28.2-50.0%). For every 10% increase in the percentage of black patients in a peer group, there was a 41% increase in the odds of delayed surgery for women in that peer group regardless of a patient's own race [odds ratio (OR) 1.41, 95% confidence interval (CI) 1.15-1.73]. Women in physician peer groups with the highest provider density were less likely to receive delayed surgery than those in physician peer groups with the lowest provider density (OR 0.65, 95% CI 0.44-0.98). We did not find an association between provider transitivity and delayed surgery. The likelihood of surgical delay varied substantially across physician peer groups and was associated with provider density and patient racial composition.

  14. Effects of reproductive status, social rank, sex and group size on vigilance patterns in Przewalski's gazelle.

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    Chunlin Li

    Full Text Available Quantifying vigilance and exploring the underlying mechanisms has been the subject of numerous studies. Less attention has focused on the complex interplay between contributing factors such as reproductive status, social rank, sex and group size. Reproductive status and social rank are of particular interest due to their association with mating behavior. Mating activities in rutting season may interfere with typical patterns of vigilance and possibly interact with social rank. In addition, balancing the tradeoff between vigilance and life maintenance may represent a challenge for gregarious ungulate species rutting under harsh winter conditions. We studied vigilance patterns in the endangered Przewalski's gazelle (Procapra przewalskii during both the rutting and non-rutting seasons to examine these issues.Field observations were carried out with focal sampling during rutting and non-rutting season in 2008-2009. Results indicated a complex interplay between reproductive status, social rank, sex and group size in determining vigilance in this species. Vigilance decreased with group size in female but not in male gazelles. Males scanned more frequently and thus spent more time vigilant than females. Compared to non-rutting season, gazelles increased time spent scanning at the expense of bedding in rutting season. During the rutting season, territorial males spent a large proportion of time on rutting activities and were less vigilant than non-territorial males. Although territorial males may share collective risk detection with harem females, we suggest that they are probably more vulnerable to predation because they seemed reluctant to leave rut stands under threats.Vigilance behavior in Przewalski's gazelle was significantly affected by reproductive status, social rank, sex, group size and their complex interactions. These findings shed light on the mechanisms underlying vigilance patterns and the tradeoff between vigilance and other crucial

  15. Factors associated with delay in trauma team activation and impact on patient outcomes.

    Science.gov (United States)

    Connolly, Rory; Woo, Michael Y; Lampron, Jacinthe; Perry, Jeffrey J

    2017-09-05

    Trauma code activation is initiated by emergency physicians using physiological and anatomical criteria, mechanism of injury, and patient demographic factors. Our objective was to identify factors associated with delayed trauma team activation. We assessed consecutive cases from a regional trauma database from January 2008 to March 2014. We defined a delay in trauma code activation as a time greater than 30 minutes from the time of arrival. We conducted univariate analysis for factors potentially influencing trauma team activation, and we subsequently used multiple logistic regression analysis models for delayed activation in relation to mortality, length of stay, and time to operative management. Patients totalling 846 were included for our analysis; 4.1% (35/846) of trauma codes were activated after 30 minutes. Mean age was 40.8 years in the early group versus 49.2 in the delayed group (p=0.01). Patients were over age 70 years in 7.6% in the early activation group versus 17.1% in the delayed group (p=0.04). There was no significant difference in sex, type of injury, injury severity, or time from injury between the two groups. There was no significant difference in mortality, median length of stay, or median time to operative management. Delayed activation is linked with increasing age with no clear link to increased mortality. Given the severe injuries in the delayed cohort that required activation of the trauma team, further emphasis on the older trauma patient and interventions to recognize this vulnerable population should be made.

  16. Maternal Obesity: Risks for Developmental Delays in Early Childhood.

    Science.gov (United States)

    Duffany, Kathleen O'Connor; McVeigh, Katharine H; Kershaw, Trace S; Lipkind, Heather S; Ickovics, Jeannette R

    2016-02-01

    To assess the risk for neurodevelopmental delays for children of mothers who were obese (≥200 pounds) prior to pregnancy, and to characterize delays associated with maternal obesity among children referred to and found eligible to receive Early Intervention Program services. We conducted a retrospective cohort study (N = 541,816) using a population-based New York City data warehouse with linked birth and Early Intervention data. Risks for children suspected of a delay and 'significantly delayed', with two moderate or one severe delay, were calculated. Among the group of children eligible by delay for Early Intervention, analyses assessed risk for being identified with a moderate-to-severe delay across each of five functional domains as well as risks for multiple delays. Children of mothers who were obese were more likely to be suspected of a delay (adjusted RR 1.19 [CI 1.15-1.22]) and borderline association for 'significantly delayed' (adjusted RR 1.01 [CI 1.00-1.02). Among children eligible by delay, children of mothers who were obese evidenced an increased risk for moderate-to-severe cognitive (adjusted RR 1.04 [CI 1.02-1.07]) and physical (adjusted RR 1.04 [CI 1.01-1.08]) delays and for global developmental delay (adjusted RR 1.05 [CI 1.01-1.08]). Maternal obesity is associated with increased risk of developmental delay in offspring. Among children with moderate or severe delays, maternal obesity is associated with increased risk of cognitive and physical delays as well as with increased risk for global developmental delay. While causation remains uncertain, this adds to the growing body of research reporting an association between maternal obesity and neurodevelopmental delays in offspring.

  17. Aloe vera oral administration accelerates acute radiation-delayed wound healing by stimulating transforming growth factor-β and fibroblast growth factor production.

    Science.gov (United States)

    Atiba, Ayman; Nishimura, Mayumi; Kakinuma, Shizuko; Hiraoka, Takeshi; Goryo, Masanobu; Shimada, Yoshiya; Ueno, Hiroshi; Uzuka, Yuji

    2011-06-01

    Delayed wound healing is a significant clinical problem in patients who have had previous irradiation. This study investigated the effectiveness of Aloe vera (Av) on acute radiation-delayed wound healing. The effect of Av was studied in radiation-exposed rats compared with radiation-only and control rats. Skin wounds were excised on the back of rats after 3 days of local radiation. Wound size was measured on days 0, 3, 6, 9, and 12 after wounding. Wound tissues were examined histologically and the expressions of transforming growth factor β-1 (TGF-β-1) and basic fibroblast growth factor (bFGF) were examined by immunohistochemistry and reverse-transcription polymerase chain reaction. Wound contraction was accelerated significantly by Av on days 6 and 12 after wounding. Furthermore, the inflammatory cell infiltration, fibroblast proliferation, collagen deposition, angiogenesis, and the expression levels of TGF-β-1 and bFGF were significantly higher in the radiation plus Av group compared with the radiation-only group. These data showed the potential application of Av to improve the acute radiation-delayed wound healing by increasing TGF-β-1 and bFGF production. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2017-05-01

    Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

  19. Thalidomide for control delayed vomiting in cancer patients receiving chemotherapy

    International Nuclear Information System (INIS)

    Han, Z.; Sun, X.; Du, X.

    2016-01-01

    To explore the efficacy and safety of thalidomide for the treatment of delayed vomiting, induced by chemotherapy in cancer patients. Study Design: Randomized, double-blind controlled study. Place and Duration of Study: The Oncology Department of Affiliated Hospital of Xuzhou Medical University, Jiangsu Xuzhou, China, from January 2012 to January 2014. Methodology: A total of 78 cancer patients, who had delayed vomiting observed from 24 hours to 1 week after chemotherapy, were included in the study. Patients were divided in a treatment group (40 patients, 51.28%) and a control group (38 patients, 48.71%). The treatment group received thalidomide at an oral dose of 100 mg per night; 50 mg was added daily up to a dose of 200 mg per night, if the curative effect was suboptimal and the medicine was tolerated. Both the treatment and the control groups received a drip of 10 mg azasetron 30 minutes before chemotherapy. The control group only proportions of antiemetic effects and adverse reactions were compared using the ?2 test. Antiemetic effects and adverse reactions were assessed from Odds Ratios (OR) with 95% Confidence Intervals(95% CI). Results: The effective control rate of delayed vomiting in the treatment group was significantly higher than that in the control group (?2=5.174, p=0.023). No significant difference was found between the two groups in other adverse effects of chemotherapy. Karnofsky scores or the overall self-evaluation of the patients (p>0.05). Conclusion: Thalidomide can effectively control the delayed vomiting of cancer patients receiving chemotherapy and the adverse reactions of the agent can be tolerated.

  20. Long-term resource variation and group size: A large-sample field test of the Resource Dispersion Hypothesis

    Directory of Open Access Journals (Sweden)

    Morecroft Michael D

    2001-07-01

    Full Text Available Abstract Background The Resource Dispersion Hypothesis (RDH proposes a mechanism for the passive formation of social groups where resources are dispersed, even in the absence of any benefits of group living per se. Despite supportive modelling, it lacks empirical testing. The RDH predicts that, rather than Territory Size (TS increasing monotonically with Group Size (GS to account for increasing metabolic needs, TS is constrained by the dispersion of resource patches, whereas GS is independently limited by their richness. We conducted multiple-year tests of these predictions using data from the long-term study of badgers Meles meles in Wytham Woods, England. The study has long failed to identify direct benefits from group living and, consequently, alternative explanations for their large group sizes have been sought. Results TS was not consistently related to resource dispersion, nor was GS consistently related to resource richness. Results differed according to data groupings and whether territories were mapped using minimum convex polygons or traditional methods. Habitats differed significantly in resource availability, but there was also evidence that food resources may be spatially aggregated within habitat types as well as between them. Conclusions This is, we believe, the largest ever test of the RDH and builds on the long-term project that initiated part of the thinking behind the hypothesis. Support for predictions were mixed and depended on year and the method used to map territory borders. We suggest that within-habitat patchiness, as well as model assumptions, should be further investigated for improved tests of the RDH in the future.

  1. Improved Delayed-Neutron Spectroscopy Using Trapped Ions

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Eric

    2018-04-24

    The neutrons emitted following the  decay of fission fragments (known as delayed neutrons because they are emitted after fission on a timescale of the -decay half-lives) play a crucial role in reactor performance and control. Reviews of delayed-neutron properties highlight the need for high-quality data for a wide variety of delayed-neutron emitters to better understand the timedependence and energy spectrum of the neutrons as these properties are essential for a detailed understanding of reactor kinetics needed for reactor safety and to understand the behavior of these reactors under various accident and component-failure scenarios. For fast breeder reactors, criticality calculations require accurate delayed-neutron energy spectra and approximations that are acceptable for light-water reactors such as assuming the delayed-neutron and fission-neutron energy spectra are identical are not acceptable and improved -delayed neutron data is needed for safety and accident analyses for these reactors. With improved nuclear data, the delayedneutrons flux and energy spectrum could be calculated from the contributions from individual isotopes and therefore could be accurately modeled for any fuel-cycle concept, actinide mix, or irradiation history. High-quality -delayed neutron measurements are also critical to constrain modern nuclear-structure calculations and empirical models that predict the decay properties for nuclei for which no data exists and improve the accuracy and flexibility of the existing empirical descriptions of delayed neutrons from fission such as the six-group representation

  2. How many segments are necessary to characterize delayed colonic transit time?

    Science.gov (United States)

    Bouchoucha, Michel; Devroede, Ghislain; Bon, Cyriaque; Raynaud, Jean-Jacques; Bejou, Bakhtiar; Benamouzig, Robert

    2015-10-01

    Measuring colonic transit time with radiopaque markers is simple, inexpensive, and very useful in constipated patients. Yet, the algorithm used to identify colonic segments is subjective, rather than founded on prior experimentation. The aim of the present study is to describe a rational way to determine the colonic partition in the measurement of colonic transit time. Colonic transit time was measured in seven segments: ascending colon, hepatic flexure, right and left transverse colon, splenic flexure, descending colon, and rectosigmoid in 852 patients with functional bowel and anorectal disorders. An unsupervised algorithm for modeling Gaussian mixtures served to estimate the number of subgroups from this oversegmented colonic transit time. After that, we performed a k-means clustering that separated the observations into homogenous groups of patients according to their oversegmented colonic transit time. The Gaussian mixture followed by the k-means clustering defined 4 populations of patients: "normal and fast transit" (n = 548) and three groups of patients with delayed colonic transit time "right delay" (n = 82) in which transit is delayed in the right part of the colon, "left delay" (n = 87) with transit delayed in the left part of colon and "outlet constipation" (n = 135) for patients with transit delayed in the terminal intestine. Only 3.7 % of patients were "erroneously" classified in the 4 groups recognized by clustering. This unsupervised analysis of segmental colonic transit time shows that the classical division of the colon and the rectum into three segments is sufficient to characterize delayed segmental colonic transit time.

  3. The effect of peer-group size on the delivery of feedback in basic life support refresher training: a cluster randomized controlled trial.

    Science.gov (United States)

    Cho, Youngsuk; Je, Sangmo; Yoon, Yoo Sang; Roh, Hye Rin; Chang, Chulho; Kang, Hyunggoo; Lim, Taeho

    2016-07-04

    Students are largely providing feedback to one another when instructor facilitates peer feedback rather than teaching in group training. The number of students in a group affect the learning of students in the group training. We aimed to investigate whether a larger group size increases students' test scores on a post-training test with peer feedback facilitated by instructor after video-guided basic life support (BLS) refresher training. Students' one-rescuer adult BLS skills were assessed by a 2-min checklist-based test 1 year after the initial training. A cluster randomized controlled trial was conducted to evaluate the effect of student number in a group on BLS refresher training. Participants included 115 final-year medical students undergoing their emergency medicine clerkship. The median number of students was 8 in the large groups and 4 in the standard group. The primary outcome was to examine group differences in post-training test scores after video-guided BLS training. Secondary outcomes included the feedback time, number of feedback topics, and results of end-of-training evaluation questionnaires. Scores on the post-training test increased over three consecutive tests with instructor-led peer feedback, but not differ between large and standard groups. The feedback time was longer and number of feedback topics generated by students were higher in standard groups compared to large groups on the first and second tests. The end-of-training questionnaire revealed that the students in large groups preferred the smaller group size compared to their actual group size. In this BLS refresher training, the instructor-led group feedback increased the test score after tutorial video-guided BLS learning, irrespective of the group size. A smaller group size allowed more participations in peer feedback.

  4. Diagnosis delay in Libyan female breast cancer.

    Science.gov (United States)

    Ermiah, Eramah; Abdalla, Fathi; Buhmeida, Abdelbaset; Larbesh, Entesar; Pyrhönen, Seppo; Collan, Yrjö

    2012-08-21

    To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008-2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3-6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV.Diagnosis delay was associated with bigger tumour size (p Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast

  5. Diagnosis delay in Libyan female breast cancer

    Directory of Open Access Journals (Sweden)

    Ermiah Eramah

    2012-08-01

    Full Text Available Abstract Aims To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. Methods 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008–2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay. Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire during an interview with each patient and from medical records. Results The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3–6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s that did not include a lump (p  Diagnosis delay was associated with bigger tumour size (p Conclusions Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing

  6. Dynamics of a delay differential equation model of hepatitis B virus infection.

    Science.gov (United States)

    Gourley, Stephen A; Kuang, Yang; Nagy, John D

    2008-04-01

    We formulate and systematically study the global dynamics of a simple model of hepatitis B virus in terms of delay differential equations. This model has two important and novel features compared to the well-known basic virus model in the literature. Specifically, it makes use of the more realistic standard incidence function and explicitly incorporates a time delay in virus production. As a result, the infection reproduction number is no longer dependent on the patient liver size (number of initial healthy liver cells). For this model, the existence and the component values of the endemic steady state are explicitly dependent on the time delay. In certain biologically interesting limiting scenarios, a globally attractive endemic equilibrium can exist regardless of the time delay length.

  7. Relationship between gender in the board of directors and the audit committee with the audit delay

    Directory of Open Access Journals (Sweden)

    Luis Antonio Lay

    2017-12-01

    Full Text Available The study verified the relationship between the gender in the composition of the board of directors and the audit committee with the audit delay. The survey sample consisted of 75 companies belonging to the IBrX 100 index. The variables surveyed were the presence of women on the board of directors and on the audit committee, size of the audit committee, independence of the board of directors, expertise, company size, debt, size of the audit firm and audit fees. Data collection took place in the Reference Form and the Economática® database. Data analysis was performed using descriptive statistics and multiple linear regression using SPSS® software. It was found that the presence of women is greater on the board than on the audit committee, with a small number of experienced members. The results showed that the presence of women on the audit committee has a negative and significant association with the audit delay, that is, the presence of women in this organism of corporate governance contributes to the reduction of the period of disclosure of the auditor's report. In addition, the size of the company and the independence of the board of directors were also important in the final model in relation to the audit delay. The presence of women on the board of directors was not significant with the delay in the audit.

  8. Effect of Group-Selection Opening Size on Breeding Bird Habitat Use in a Bottomland Forest

    Energy Technology Data Exchange (ETDEWEB)

    Moorman, C.E.; D.C. Guynn, Jr.

    2001-12-01

    Research on the effects of creating group-selection openings of various sizes on breeding birds habitat use in a bottomland hardwood forest of the Upper Coastal Plain of South Carolina. Creation of 0.5-ha group selection openings in southern bottomland forests should provide breeding habitat for some field-edge species in gaps and habitat for forest-interior species and canopy-dwelling forest-edge species between gaps provided that enough mature forest is made available.

  9. Size of government and entrepreneurship. Analysis of three groups of countries with different economic development

    Directory of Open Access Journals (Sweden)

    Juan Carlos Díaz Casero

    2015-07-01

    Full Text Available This study analyzes the impact of the "size of government" in entrepreneurial activity for countries with different levels of economical development. It has been used the variables "size of government" of the economic freedom indices released by the Economic Freedom Network (2000-2009 and by The Heritage Foundation (2000-2011, and the variables of "entrepreneurship" released by the Global Entrepreneurship Monitor. Furthermore, the same analysis has been carried out grouping the countries by development level, following the classification elaborated by the World Economic Forum. Statistical analyses of correlations have shown that the “size of government” is related to entrepreneurship. The variables "Size of Government: Expenditures, Taxes and Enterprises" and " Government Size” have revealed a positive correlation with the total, opportunity and necessity entrepreneurial activity indices for the economies based on efficiency and innovation, thus less taxes on income and lower government spending, increase the entrepreneurship of the country. In “factor driven economies”, there is no relationship between the size of government and entrepreneurship

  10. Induction of Hopf bifurcation and oscillation death by delays in coupled networks

    International Nuclear Information System (INIS)

    Cheng, C.-Y.

    2009-01-01

    This work explores a system of two coupled networks that each has four nodes. Delayed effects of short-cuts in each network and the coupling between the two groups are considered. When the short-cut delay is fixed, the arising and death of oscillations are caused by the variational coupling delay.

  11. Better working memory and motor inhibition in children who delayed gratification

    Directory of Open Access Journals (Sweden)

    Junhong Yu

    2016-07-01

    Full Text Available Background: Despite the extensive research on delayed gratification over the past few decades, the neurocognitive processes that subserve delayed gratification remains unclear. As an exploratory step in studying these processes, the present study aims to describe the executive function profiles of children who were successful at delaying gratification and those who were not. =Methods: A total of 138 kindergarten students (65 males, 73 females; Mage = 44 months, SD= 3.5; age range= 37 to 53 months were administered a delayed gratification task, a 1-back test, a Day/night Stroop test and a Go/no-go test. The outcome measures of these tests were then analyzed between groups using a Multivariate Analysis of Variance, and subsequently a Multivariate Analysis of Covariance incorporating age as a covariate.Results: Children who were successful in delaying gratification were significantly older and had significantly better outcomes in the 1-back test and go/no-go test. With the exception of the number of hits in the go/no-go test, all other group differences remained significant after controlling for age.Conclusion:Children who were successful in delaying gratification showed better working memory and motor inhibition relative to those who failed the delayed gratification task. The implications of these findings are discussed

  12. Better Working Memory and Motor Inhibition in Children Who Delayed Gratification

    Science.gov (United States)

    Yu, Junhong; Kam, Chi-Ming; Lee, Tatia M. C.

    2016-01-01

    Background: Despite the extensive research on delayed gratification over the past few decades, the neurocognitive processes that subserve delayed gratification remains unclear. As an exploratory step in studying these processes, the present study aims to describe the executive function profiles of children who were successful at delaying gratification and those who were not. Methods: A total of 138 kindergarten students (65 males, 73 females; Mage = 44 months, SD = 3.5; age range = 37–53 months) were administered a delayed gratification task, a 1-back test, a Day/night Stroop test and a Go/no-go test. The outcome measures of these tests were then analyzed between groups using a Multivariate Analysis of Variance, and subsequently a Multivariate Analysis of Covariance incorporating age as a covariate. Results: Children who were successful in delaying gratification were significantly older and had significantly better outcomes in the 1-back test and go/no-go test. With the exception of the number of hits in the go/no-go test, all other group differences remained significant after controlling for age. Conclusion: Children who were successful in delaying gratification showed better working memory and motor inhibition relative to those who failed the delayed gratification task. The implications of these findings are discussed. PMID:27493638

  13. The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats.

    Science.gov (United States)

    Sá, Jairo Zacchê de; Aguiar, José Lamartine de Andrade; Cruz, Adriana Ferreira; Schuler, Alexandre Ricardo Pereira; Lima, José Ricardo Alves de; Marques, Olga Martins

    2012-12-01

    To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.

  14. Simultaneous Buffer-sizing and Wire-sizing for Clock Trees Based on Lagrangian Relaxation

    Directory of Open Access Journals (Sweden)

    Yu-Min Lee

    2002-01-01

    Full Text Available Delay, power, skew, area and sensitivity are the most important concerns in current clock-tree design. We present in this paper an algorithm for simultaneously optimizing the above objectives by sizing wires and buffers in clock trees. Our algorithm, based on Lagrangian relaxation method, can optimally minimize delay, power and area simultaneously with very low skew and sensitivity. With linear storage overall and linear runtime per iteration, our algorithm is extremely economical, fast and accurate; for example, our algorithm can solve a 6201-wire-segment clock-tree problem using about 1-minute runtime and 1.3-MB memory and still achieve pico-second precision on an IBM RS/6000 workstation.

  15. The Impact of Group Size on Welfare Indicators of Ewes during Pregnancy

    Science.gov (United States)

    Averós, Xavier; Beltrán de Heredia, Ignacia; Ruiz, Roberto; Estevez, Inma

    2016-01-01

    Group size (GS) and space allowance have major implications for the welfare of production species, however their effects are often confounded. In a previous study we investigated the impact of varying space allowance at constant GS. In the present work we report the consequences of varying GS on pregnant ewes while controlling space allowance. We housed ewes at 6 (GS6) or 12 ewes/enclosure (GS12), while controlling space allowance to 1.5 m2/ewe (3 enclosures/treatment), and necessarily varying enclosure size. Therefore, when indicating GS effects we implicitly reflect a confounding effect with that of enclosure size. Movement, use of space, behaviour, serum cortisol concentration and body condition score (BCS) were collected during the last 12 gestation weeks. Movement, use of space, and behaviour were collected every other week, during 2 days/week, using 10 minute continuous scan samplings. Blood was collected during weeks 10, 13, 17, and 21 of gestation, and BCS during weeks 15 and 21. Data were analysed using repeated measures, generalized linear mixed models, with GS, week, and their interaction as fixed effects, and enclosure as random effect. GS mainly affected movement and use of space. GS12 ewes walked longer distances using longer steps (Pewe is given during gestation, larger GS will result in larger effective space, and no major implications for the welfare of ewes should be expected as GS increases. Ewes will adapt their movement patterns and use of space to enclosure size, and no further behavioural, physiological and physical consequences should be expected. PMID:27893817

  16. Factors influencing diagnosis delay of advanced breast cancer in Moroccan women

    OpenAIRE

    Maghous, A.; Rais, F.; Ahid, S.; Benhmidou, N.; Bellahamou, K.; Loughlimi, H.; Marnouche, E.; Elmajjaoui, S.; Elkacemi, H.; Kebdani, T.; Benjaafar, N.

    2016-01-01

    Background Delay in the diagnosis of breast cancer in symptomatic women of 3?months or more is associated with advanced stage and low survival. We conducted this study to learn more about the extent and reasons behind diagnosis delay of advanced breast cancer in Moroccan women. Methods A group of patients with advanced breast cancer were interviewed at the National Institute of Oncology in Rabat during the period from February to December 2014. Diagnosis delay was devised into patient delay a...

  17. Delay and probability discounting of sexual and monetary outcomes in individuals with cocaine use disorders and matched controls.

    Science.gov (United States)

    Johnson, Matthew W; Johnson, Patrick S; Herrmann, Evan S; Sweeney, Mary M

    2015-01-01

    Individuals with cocaine use disorders are disproportionately affected by HIV/AIDS, partly due to higher rates of unprotected sex. Recent research suggests delay discounting of condom use is a factor in sexual HIV risk. Delay discounting is a behavioral economic concept describing how delaying an event reduces that event's value or impact on behavior. Probability discounting is a related concept describing how the uncertainty of an event decreases its impact on behavior. Individuals with cocaine use disorders (n = 23) and matched non-cocaine-using controls (n = 24) were compared in decision-making tasks involving hypothetical outcomes: delay discounting of condom-protected sex (Sexual Delay Discounting Task), delay discounting of money, the effect of sexually transmitted infection (STI) risk on likelihood of condom use (Sexual Probability Discounting Task), and probability discounting of money. The Cocaine group discounted delayed condom-protected sex (i.e., were more likely to have unprotected sex vs. wait for a condom) significantly more than controls in two of four Sexual Delay Discounting Task partner conditions. The Cocaine group also discounted delayed money (i.e., preferred smaller immediate amounts over larger delayed amounts) significantly more than controls. In the Sexual Probability Discounting Task, both groups showed sensitivity to STI risk, however the groups did not differ. The Cocaine group did not consistently discount probabilistic money more or less than controls. Steeper discounting of delayed, but not probabilistic, sexual outcomes may contribute to greater rates of sexual HIV risk among individuals with cocaine use disorders. Probability discounting of sexual outcomes may contribute to risk of unprotected sex in both groups. Correlations showed sexual and monetary results were unrelated, for both delay and probability discounting. The results highlight the importance of studying specific behavioral processes (e.g., delay and probability

  18. Delay and probability discounting of sexual and monetary outcomes in individuals with cocaine use disorders and matched controls.

    Directory of Open Access Journals (Sweden)

    Matthew W Johnson

    Full Text Available Individuals with cocaine use disorders are disproportionately affected by HIV/AIDS, partly due to higher rates of unprotected sex. Recent research suggests delay discounting of condom use is a factor in sexual HIV risk. Delay discounting is a behavioral economic concept describing how delaying an event reduces that event's value or impact on behavior. Probability discounting is a related concept describing how the uncertainty of an event decreases its impact on behavior. Individuals with cocaine use disorders (n = 23 and matched non-cocaine-using controls (n = 24 were compared in decision-making tasks involving hypothetical outcomes: delay discounting of condom-protected sex (Sexual Delay Discounting Task, delay discounting of money, the effect of sexually transmitted infection (STI risk on likelihood of condom use (Sexual Probability Discounting Task, and probability discounting of money. The Cocaine group discounted delayed condom-protected sex (i.e., were more likely to have unprotected sex vs. wait for a condom significantly more than controls in two of four Sexual Delay Discounting Task partner conditions. The Cocaine group also discounted delayed money (i.e., preferred smaller immediate amounts over larger delayed amounts significantly more than controls. In the Sexual Probability Discounting Task, both groups showed sensitivity to STI risk, however the groups did not differ. The Cocaine group did not consistently discount probabilistic money more or less than controls. Steeper discounting of delayed, but not probabilistic, sexual outcomes may contribute to greater rates of sexual HIV risk among individuals with cocaine use disorders. Probability discounting of sexual outcomes may contribute to risk of unprotected sex in both groups. Correlations showed sexual and monetary results were unrelated, for both delay and probability discounting. The results highlight the importance of studying specific behavioral processes (e.g., delay and

  19. Stability and delay sensitivity of neutral fractional-delay systems.

    Science.gov (United States)

    Xu, Qi; Shi, Min; Wang, Zaihua

    2016-08-01

    This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

  20. Projects Delay Factors of Saudi Arabia Construction Industry Using PLS-SEM Path Modelling Approach

    Directory of Open Access Journals (Sweden)

    Abdul Rahman Ismail

    2016-01-01

    Full Text Available This paper presents the development of PLS-SEM Path Model of delay factors of Saudi Arabia construction industry focussing on Mecca City. The model was developed and assessed using SmartPLS v3.0 software and it consists of 37 factors/manifests in 7 groups/independent variables and one dependent variable which is delay of the construction projects. The model was rigorously assessed at measurement and structural components and the outcomes found that the model has achieved the required threshold values. At structural level of the model, among the seven groups, the client and consultant group has the highest impact on construction delay with path coefficient β-value of 0.452 and the project management and contract administration group is having the least impact to the construction delay with β-value of 0.016. The overall model has moderate explaining power ability with R2 value of 0.197 for Saudi Arabia construction industry representation. This model will able to assist practitioners in Mecca city to pay more attention in risk analysis for potential construction delay.

  1. FAKTOR-FAKTOR YANG MEMPENGARUHI AUDIT DELAY PADA PERUSAHAAN-PERUSAHAAN GO PUBLIC DI BEJ

    Directory of Open Access Journals (Sweden)

    Reni Yendrawati

    2017-03-01

    Full Text Available Timeliness represented a very important matter in determining financial statementvalue. This research was purposed to investigate the influence of audit delay factors, namelycompany size, company that announced loss, level of company profitability, auditor’s opinionand industrial sector. Audit delay could affect the timeliness of accounting information releases,and it would be known that timeliness was associated with the market reaction to theinformation released. Sampels were selected by method of purposive sampling. Regressionanalysis was used to investigate audit delay factors. The results could be interpreted thataudit delays tended to be longer for the company that announced loss in non-manufacture’ssampel, auditor’s opinion in overall sampel and auditor’s opinion in non-manufacture’s sampel.

  2. Stoma creation: does onset of ostomy care education delay hospital length of stay?

    Science.gov (United States)

    Rashidi, Laila; Long, Kevin; Hawkins, Melinda; Menon, Raman; Bellevue, Oliver

    2016-05-01

    Balancing patient safety with hospital length of stay (LOS) and associated cost is critically important. Subjectively, we have observed that patients undergoing ostomy creation early in the week have a shorter LOS. We retrospectively reviewed LOS based on day of the week the operation was performed. We reviewed 180 patients undergoing minimally invasive surgery with planned ostomy. Group 1 underwent surgery on Monday to Wednesday (n = 77), Group 2 on Thursday (n = 49), and Group 3 on Friday (n = 54). The average LOS for Group 1, 2, and 3 was 6.2, 4.9, and 7.2 days, respectively. The average number of visits with ostomy nursing for Group 1, 2, and 3 was 2.7, 1.8, and 2.3, respectively. Day of initial ostomy nursing visit was significantly correlated between the delay to initial visit and LOS with Group 3 delayed most. Patients with the longest delay to initial nurse visit had the longest LOS, with Friday operations being most delayed. A contributing factor may be absence of ostomy teaching over the weekend. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Is immediate adjunctive CBT more beneficial than delayed CBT in treating depression?: A Pilot Study.

    Science.gov (United States)

    Rizvi, Sakina J; Zaretsky, Ari; Schaffer, Ayal; Levitt, Anthony

    2015-03-01

    Cognitive-behavioral therapy (CBT) is an efficacious first-line therapy for patients with major depressive disorder (MDD). Due to the limited accessibility of CBT, long wait lists result in delayed treatment, which may affect treatment outcomes. The goal of this pilot study was to obtain preliminary data from a randomized controlled trial to determine whether delayed CBT reduces the effectiveness of the therapy compared to immediate CBT in patients with MDD receiving pharmacotherapy. Patients were randomized to receive immediate CBT (n=18) or to begin CBT after 6 months (n=20) and received 14 weekly sessions, followed by two additional booster sessions. During the active treatment months, patients in the immediate group demonstrated reductions in scores on the Beck Depression Inventory II (BDI-II) that were similar to those in the delayed CBT group. However, when the analysis was performed using only data from patients in the delayed group who were still in a depressive episode, there was an overall greater decrease in BDI-II scores in the immediate group vs. the delayed group over the active treatment months, but not specifically at the 6-month endpoint. These findings suggest delays in depression treatment, similar to what occurs with real-world wait list times, may not have a significant impact on the effectiveness of CBT in patients who are already receiving treatment as usual. However, such delays may affect the effectiveness of CBT in those patients who remain depressed during the time delay. A larger trial is necessary to confirm these findings. (Journal of Psychiatric Practice 2015;21:107-113).

  4. Workers' compensation in Pennsylvania: the effects of delayed contested cases.

    Science.gov (United States)

    Dawson, S E

    1994-01-01

    This study examines the effects of delayed workers' compensation cases in the Pennsylvania system. Forty-five claimants of a workers' compensation support group responded to interviews. Delay periods averaged two years with a 68.4% drop in income. Results indicate that claimants endured financial and emotional stress, exhausted personal assets, relied on assistance from relatives, and received public assistance. Implications for social work practice include educating workers about benefits, counseling claimants with delayed claims, and advocating for administrative reforms.

  5. Effect of Delayed Bonding and Antioxidant Application on the Bond Strength to Enamel after Internal Bleaching.

    Science.gov (United States)

    Kılınç, Halil İbrahim; Aslan, Tuğrul; Kılıç, Kerem; Er, Özgür; Kurt, Gökmen

    2016-07-01

    This study evaluated the effect of delayed bonding and antioxidant application (AA, 10% sodium ascorbate) after internal bleaching (35% carbamide peroxide) on the shear bond strength of an adhesive cement to enamel. Eighty-four human maxillary central incisors were endodontically treated. The control group remained unbleached with no AA. Experimental groups were all internally bleached. The buccal enamel was finished and polished with metallographic paper to a refinement of #600, in order to obtain a 5-mm(2) flat bonding area. An adhesive cement (Clearfil Esthetic) was placed into a plastic tube with internal diameter of 3 mm and a 3-mm height and cured on the enamel. Bonding occurred either immediately after bleaching (group Im), a 7-day delay (group 7), or a 14-day delay (group 14), and half the specimens were treated with antioxidant application (groups Im-AA, 7-AA, and 14-AA). Shear bond strength testing was performed on a universal testing machine, and data were analyzed with ANOVA and Fisher test (5%). Delaying of bonding is a useful factor for enhancing shear bond strength (p adhesive cementation to enamel is recommended only when delayed 14 days, or delayed 7 days with sodium ascorbate application. © 2015 by the American College of Prosthodontists.

  6. Early and delayed Tc-99m ECD brain SPECT in SLE patients with CNS involvement

    International Nuclear Information System (INIS)

    Kikukawa, Kaoru; Toyama, Hiroshi; Katayama, Masao

    2000-01-01

    We compared early and delayed Tc-99m ECD SPECT scans in 32 SLE patients (Group 1, definite neuropsychiatric disorders; Group 2, minor neurologic symptoms or normal) with those of normal controls by visual inspection and semi-quantitative evaluation. With visual interpretation, 13 out of 14 patients in Group 1 (93%) and 7 out of 18 patients in Group 2 (39%) had diffuse uneven decrease in early scans. Seven patients in Group 2 (39%) who had normal early scans demonstrated focal decrease in the medial frontal lobe in delayed scans. With cerebral region to cerebellar ratios, in early scans, the medial frontal lobe in Group 1 and Group 2 was significantly lower than in normal controls, and lateral frontal lobe and occipital lobes in Group 1 were significantly lower than in normal controls. Nevertheless, in delayed scans, every cortical region except for the parietal lode in Groups 1 and 2 was significantly lower than in normal controls. The retention rates in all regions in SLE patients were significantly lower than in normal controls. No case showed SPECT improvement on follow-up studies in either group in spite of clinical improvement. Delayed Tc-99m ECD brain SPECT of high sensitivity might be useful in detecting CNS involvement. Although the SPECT findings did not correlate with the neuropsychiatric symptoms, early and delayed Tc-99m ECD SPECT seems to provide useful objective diagnostic information in SLE patients. (author)

  7. Delayed breast reconstruction with implants after invasive breast cancer does not impair prognosis

    DEFF Research Database (Denmark)

    Holmich, L.R.; During, M.; Henriksen, T.F.

    2008-01-01

    We investigated if delayed breast implant reconstruction after breast cancer impairs prognosis. Using data from the Danish Breast Cancer Cooperative Group register, we identified all women......We investigated if delayed breast implant reconstruction after breast cancer impairs prognosis. Using data from the Danish Breast Cancer Cooperative Group register, we identified all women...

  8. [Delays produced by prolonged viewing in the recognition of Kanji characters: analysis of the "Gestaltzerfall" phenomenon].

    Science.gov (United States)

    Ninose, Y; Gyoba, J

    1996-08-01

    It is a well-known observation that when a Kanji character is viewed steadily and continuously, the viewer often becomes unable to recognize the Kanji as a whole pattern and it becomes difficult to judge whether or not the Kanji is orthographically correct. Such a phenomenon is called the "Gestaltzerfall" of Kanji characters. In the present study, two experiments were carried out to examine delays in the recognition of test Kanji following 25 s of prolonged viewing of adaptation Kanji, which were comprised of either the same or different parts and structures. When the size of the adaptation Kanji was equal to that of the test Kanji, there were significant delays of more than 50 ms, both when the stimuli were of the same pattern, and when they had the same structure but different components. However, when their sizes were different, delays were found only when the test and the adaptation Kanji were of the same pattern. These results suggest that a Kanji pattern may be internally represented as a whole, independent of its size, while the processing of Kanji structure may be dependent upon its size. Prolonged viewing may produce an adaptation effect specific to such representations.

  9. Defensive responses by a social caterpillar are tailored to different predators and change with larval instar and group size

    Science.gov (United States)

    McClure, Melanie; Despland, Emma

    2011-05-01

    Gregariousness in animals is widely accepted as a behavioral adaptation for protection from predation. However, predation risk and the effectiveness of a prey's defense can be a function of several other factors, including predator species and prey size or age. The objective of this study was to determine if the gregarious habit of Malacosoma disstria caterpillars is advantageous against invertebrate natural enemies, and whether it is through dilution or cooperative defenses. We also examined the effects of larval growth and group size on the rate and success of attacks. Caterpillars of M. disstria responded with predator-specific behaviors, which led to increased survival. Evasive behaviors were used against stinkbugs, while thrashing by fourth instar caterpillars and holding on to the silk mat by second instar caterpillars was most efficient against spider attacks. Collective head flicking and biting by groups of both second and fourth instar caterpillars were observed when attacked by parasitoids. Increased larval size decreased the average number of attacks by spiders but increased the number of attacks by both stinkbugs and parasitoids. However, increased body size decreased the success rate of attacks by all three natural enemies and increased handling time for both predators. Larger group sizes did not influence the number of attacks from predators but increased the number of attacks and the number of successful attacks from parasitoids. In all cases, individual risk was lower in larger groups. Caterpillars showed collective defenses against parasitoids but not against the walking predators. These results show that caterpillars use different tactics against different natural enemies. Overall, these tactics are both more diverse and more effective in fourth instar than in second instar caterpillars, confirming that growth reduces predation risk. We also show that grouping benefits caterpillars through dilution of risk, and, in the case of parasitoids, through

  10. The economic effect and outcome of delaying oral food challenges.

    Science.gov (United States)

    Couch, Christopher; Franxman, Tim; Greenhawt, Matthew

    2016-05-01

    Food specific IgE (sIgE) is a useful marker to assess predictability of oral food challenge (OFC) outcome. A threshold of less than 2 kUA/L for peanut, egg, and milk has been proposed as a 50% negative predictive value at which patients may pass an OFC. To assess the economic effect and outcome of delaying OFCs. A retrospective analysis was performed for peanut, egg, and milk OFCs conducted between 2001 and 2012 at a tertiary food allergy referral center. Delayed OFC was defined as greater than 12 months from the time the sIgE level became less than 2 kUA/L. Time to OFC was explored in association with skin prick test result (wheal size), OFC outcome, and the economic effect of delay. Of 319 challenges, 173 OFCs were delayed (54.2%) by a mean time of 35.5 months (range, 13-123 months) vs a mean time of 4.2 months in the 146 challenges that were not delayed (P care system. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  11. Gastric emptying measurements: delayed and complex emptying patterns without appropriate correction

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.G.; Christian, P.E.; Taylor, A.T.; Alazraki, N.

    1985-10-01

    Anteriorly acquired and geometric mean corrected gastric emptying curves of solids and liquid isotopic-labeled meals were compared in 37 subjects given 61 meals of three different sizes. Anterior data alone consistently and significantly underestimated solid-phase gastric emptying rates with all meal sizes when compared to geometric mean acquired data. However, with liquids there were only slight differences between anterior and anterior and posterior geometric mean corrected emptying-rates. The difference probably reflects greater attenuation of the 140 kev photon of /sup 99m/Tc compared to the 247 keV photon of In. With anterior data alone, an apparent early delay in emptying of solids was present with all meal sizes and the resultant emptying curves were nonlinear in shape. Geometric mean correction resulted in the linearization of the solid-phase emptying curves and essentially eliminated the apparent delay in emptying or lag phase noted with the anterior data alone. Based on our results, geometric mean correction techniques are necessary for accurate assessment of radioisotopic-labeled solid meals.

  12. Comparison of delayed versus immediate pushing during second stage of labor for nulliparous women with epidural anesthesia.

    Science.gov (United States)

    Gillesby, Erica; Burns, Suzan; Dempsey, Amy; Kirby, Shirley; Mogensen, Kami; Naylor, Kelly; Petrella, Joann; Vanicelli, Rebecca; Whelan, Breon

    2010-01-01

    To determine if the use of delayed pushing after the onset of the second stage of labor decreases the time of active pushing and decreases maternal fatigue. Randomized clinical trial. Labor and delivery unit of a not-for-profit community hospital. Convenience sample of nulliparous laboring women with epidural anesthesia. Immediate or delayed pushing (2 hours) during the second stage of labor at the time of complete cervical dilatation. The length of pushing, total length of the second stage, and maternal fatigue. A total of 77 women were studied (immediate pushing group=39; delayed pushing=38). The immediate pushing group averaged 94 (± 57) minutes in active pushing, while the delayed pushing group averaged 68 (± 46) minutes, a statistically significant difference (p=.04). No significant differences were found in fatigue scores between the immediate and delayed pushing groups (p>.05). We found that by delaying the onset of active pushing for 2 hours after the beginning of the second stage of labor, the time that nulliparous women with epidural anesthesia spent in active pushing was significantly decreased by 27%. Although the delayed pushing group rested for up to 2 hours, the total time in the second stage of labor averaged only 59 minutes longer than the immediate pushing group. © 2010 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  13. Effects of Group Size and Lack of Sphericity on the Recovery of Clusters in K-Means Cluster Analysis

    Science.gov (United States)

    de Craen, Saskia; Commandeur, Jacques J. F.; Frank, Laurence E.; Heiser, Willem J.

    2006-01-01

    K-means cluster analysis is known for its tendency to produce spherical and equally sized clusters. To assess the magnitude of these effects, a simulation study was conducted, in which populations were created with varying departures from sphericity and group sizes. An analysis of the recovery of clusters in the samples taken from these…

  14. Delay in treatment seeking of smear positive tuberculous patients

    International Nuclear Information System (INIS)

    Bhatti, A.T.; Zahid, M.

    2010-01-01

    To assess and identify the causes and circumstances leading to delays in health seeking and diagnosis of tuberculosis patients as they often present with advance disease resulting in increased morbidity and mortality. Settings Department of Tuberculosis, DOTS clinic DHQ Hospital, Vehari. Methodology One (author) inspiration diagnosed smear positive pulmonary tuberculosis patients were included. Information was gathered through interviews and from TB-01 card. Results Maximum patients were in age group of 16-40 years. Median patient delay was 4-6 months; jobless, homeless personnel had longer delay. The main reason for delay was that the symptoms were not considered serious enough. Delay in presentation of smear positive cases may be due to the lack of awareness of patients and the incompetence of some health workers. Training and supervision of staff and awareness campaigns targeted at the population and involvement of private sector will improve TB control in Vehari. (author)

  15. The role of host traits, season and group size on parasite burdens in a cooperative mammal.

    Directory of Open Access Journals (Sweden)

    Hermien Viljoen

    Full Text Available The distribution of parasites among hosts is often characterised by a high degree of heterogeneity with a small number of hosts harbouring the majority of parasites. Such patterns of aggregation have been linked to variation in host exposure and susceptibility as well as parasite traits and environmental factors. Host exposure and susceptibility may differ with sexes, reproductive effort and group size. Furthermore, environmental factors may affect both the host and parasite directly and contribute to temporal heterogeneities in parasite loads. We investigated the contributions of host and parasite traits as well as season on parasite loads in highveld mole-rats (Cryptomys hottentotus pretoriae. This cooperative breeder exhibits a reproductive division of labour and animals live in colonies of varying sizes that procreate seasonally. Mole-rats were parasitised by lice, mites, cestodes and nematodes with mites (Androlaelaps sp. and cestodes (Mathevotaenia sp. being the dominant ecto- and endoparasites, respectively. Sex and reproductive status contributed little to the observed parasite prevalence and abundances possibly as a result of the shared burrow system. Clear seasonal patterns of parasite prevalence and abundance emerged with peaks in summer for mites and in winter for cestodes. Group size correlated negatively with mite abundance while it had no effect on cestode burdens and group membership affected infestation with both parasites. We propose that the mode of transmission as well as social factors constrain parasite propagation generating parasite patterns deviating from those commonly predicted.

  16. Introduction to Focus Issue: Time-delay dynamics

    Science.gov (United States)

    Erneux, Thomas; Javaloyes, Julien; Wolfrum, Matthias; Yanchuk, Serhiy

    2017-11-01

    The field of dynamical systems with time delay is an active research area that connects practically all scientific disciplines including mathematics, physics, engineering, biology, neuroscience, physiology, economics, and many others. This Focus Issue brings together contributions from both experimental and theoretical groups and emphasizes a large variety of applications. In particular, lasers and optoelectronic oscillators subject to time-delayed feedbacks have been explored by several authors for their specific dynamical output, but also because they are ideal test-beds for experimental studies of delay induced phenomena. Topics include the control of cavity solitons, as light spots in spatially extended systems, new devices for chaos communication or random number generation, higher order locking phenomena between delay and laser oscillation period, and systematic bifurcation studies of mode-locked laser systems. Moreover, two original theoretical approaches are explored for the so-called Low Frequency Fluctuations, a particular chaotical regime in laser output which has attracted a lot of interest for more than 30 years. Current hot problems such as the synchronization properties of networks of delay-coupled units, novel stabilization techniques, and the large delay limit of a delay differential equation are also addressed in this special issue. In addition, analytical and numerical tools for bifurcation problems with or without noise and two reviews on concrete questions are proposed. The first review deals with the rich dynamics of simple delay climate models for El Nino Southern Oscillations, and the second review concentrates on neuromorphic photonic circuits where optical elements are used to emulate spiking neurons. Finally, two interesting biological problems are considered in this Focus Issue, namely, multi-strain epidemic models and the interaction of glucose and insulin for more effective treatment.

  17. Beta-delayed neutron decay of $^{33}$Na

    CERN Document Server

    Radivojevic, Z; Caurier, E; Cederkäll, J; Courtin, S; Dessagne, P; Jokinen, A; Knipper, A; Le Scornet, G; Lyapin, V G; Miehé, C; Nowacki, F; Nummela, S; Oinonen, M; Poirier, E; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    Beta-delayed neutron decay of /sup 33/Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the /sup 33/Na decay, showing evidence for strong feeding of states at about 4 MeV in /sup 33/Mg. By simultaneous beta - gamma -n counting the delayed neutron emission probabilities P/sub 1n/ = 47(6)% and P /sub 2n/ = 13(3)% were determined. The half-life value for /sup 33 /Na, T/sub 1/2/ = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. (21 refs).

  18. Lesions Responsible for Delayed Oral Transit Time in Post-stroke Dysphagia.

    Science.gov (United States)

    Moon, Hyun Im; Yoon, Seo Yeon; Yi, Tae Im; Jeong, Yoon Jeong; Cho, Tae Hwan

    2017-10-11

    Some stroke patients show oral phase dysphagia, characterized by a markedly prolonged oral transit time that hinders oral feeding. The aim of this study was to clarify the clinical characteristics and lesions responsible for delayed swallowing. We reviewed 90 patients with stroke. The oral processing time plus the postfaucial aggregation time required to swallow semisolid food was assessed. The patients were divided into two groups according to oral transit time, and we analyzed the differences in characteristics such as demographic factors, lesion factors, and cognitive function. Logistic regression analyses were performed to examine the predictors of delayed oral transit time. Lesion location and volume were measured on brain magnetic resonance images. We generated statistic maps of lesions related to delayed oral phase in swallowing using voxel-based lesion symptom mapping (VLSM). The group of patients who showed delayed oral transit time had significantly low cognitive function. Also, in a regression model, delayed oral phase was predicted with low K-MMSE (Korean version of the Mini Mental Status Exam). Using VLSM, we found the lesion location to be associated with delayed oral phase after adjusting for K-MMSE score. Although these results did not reach statistical significance, they showed the lesion pattern with predominant distribution in the left frontal lobe. Delayed oral phase in post-stroke patients was not negligible clinically. Patients' cognitive impairments affect the oral transit time. When adjusting it, we found a trend that the lesion responsible for delayed oral phase was located in the left frontal lobe, though the association did not reach significance. The delay might be related to praxis function.

  19. Development of an online database of typical food portion sizes in Irish population groups.

    Science.gov (United States)

    Lyons, Jacqueline; Walton, Janette; Flynn, Albert

    2013-01-01

    The Irish Food Portion Sizes Database (available at www.iuna.net) describes typical portion weights for an extensive range of foods and beverages for Irish children, adolescents and adults. The present paper describes the methodologies used to develop the database and some key characteristics of the portion weight data contained therein. The data are derived from three large, cross-sectional food consumption surveys carried out in Ireland over the last decade: the National Children's Food Survey (2003-2004), National Teens' Food Survey (2005-2006) and National Adult Nutrition Survey (2008-2010). Median, 25th and 75th percentile portion weights are described for a total of 545 items across the three survey groups, split by age group or sex as appropriate. The typical (median) portion weights reported for adolescents and adults are similar for many foods, while those reported for children are notably smaller. Adolescent and adult males generally consume larger portions than their female counterparts, though similar portion weights may be consumed where foods are packaged in unit amounts (for example, pots of yoghurt). The inclusion of energy under-reporters makes little difference to the estimation of typical portion weights in adults. The data have wide-ranging applications in dietary assessment and food labelling, and will serve as a useful reference against which to compare future portion size data from the Irish population. The present paper provides a useful context for researchers and others wishing to use the Irish Food Portion Sizes Database, and may guide researchers in other countries in establishing similar databases of their own.

  20. Emergency surgery pre-operative delays - realities and economic impacts.

    Science.gov (United States)

    O'Leary, D P; Beecher, S; McLaughlin, R

    2014-12-01

    A key principle of acute surgical service provision is the establishment of a distinct patient flow process and an emergency theatre. Time-to-theatre (TTT) is a key performance indicator of theatre efficiency. The combined impacts of an aging population, increasing demands and complexity associated with centralisation of emergency and oncology services has placed pressure on emergency theatre access. We examined our institution's experience with running a designated emergency theatre for acute surgical patients. A retrospective review of an electronic prospectively maintained database was performed between 1/1/12 and 31/12/13. A cost analysis was conducted to assess the economic impact of delayed TTT, with every 24hr delay incurring the cost of an additional overnight bed. Delays and the economic effects were assessed only after the first 24 h as an in-patient had elapsed. In total, 7041 procedures were performed. Overall mean TTT was 26 h, 2 min. There were significant differences between different age groups, with those aged under 16 year and over 65 having mean TTT at 6 h, 34 min (95% C.I. 0.51-2.15, p 65 years age group had a mean TTT of 23 h, 41 min which was significantly longer than the overall mean TTT Vascular and urological emergencies are significantly disadvantaged in competition with other services for a shared emergency theatre. The economic impact of delayed TTT was calculated at €7,116,000, or €9880/day of additional costs generated from delayed TTT over a 24 month period. One third of patients waited longer than 24 h for emergency surgery, with the elderly disproportionately represented in this group. Aside from the clinical risks of delayed and out of hours surgery, such practices incur significant additional costs. New strategies must be devised to ensure efficient access to emergency theatres, investment in such services is likely to be financially and clinically beneficial. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier

  1. Congenital rubella syndrome and delayed manifestations

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup

    2010-01-01

    Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who hav...... which people with CRS face must primarily be understood in relation to congenital deafblindness and dual sensory and communicative deprivation....... CRS and who are congenitally deafblind. Results: None of the hypotheses could be confirmed when individuals with CRS were compared to a control group of individuals who were congenital deafblind with different aetiology than CRS. Conclusions: This study concludes that those health related problems...

  2. Delay in Diagnosis of Celiac Disease in Patients Without Gastrointestinal Complaints.

    Science.gov (United States)

    Paez, Marco A; Gramelspacher, Anna Maria; Sinacore, James; Winterfield, Laura; Venu, Mukund

    2017-11-01

    The purpose of our study is to investigate the delay in diagnosis of patients with biopsy-proven celiac disease in those who present with gastrointestinal complaints vs nongastrointestinal complaints at our tertiary care center. Celiac disease is an autoimmune disorder that affects approximately 1% of the population worldwide. Celiac disease can have variable clinical presentations; it can be characterized by predominately gastrointestinal symptoms, or it may present without any gastrointestinal symptoms. We retrospectively reviewed the charts of 687 adult patients who carried the diagnosis of celiac disease. Patients included had biopsy-proven celiac disease and were categorized based on presence or absence of gastrointestinal symptoms prior to their diagnosis. There were 101 patients with biopsy-proven celiac disease that met inclusion criteria. Fifty-two patients presented with gastrointestinal symptoms and 49 had nongastrointestinal complaints. Results from Mann-Whitney statistical analysis showed a median delay in diagnosis of 2.3 months for the gastrointestinal symptoms group and 42 months for the nongastrointestinal group (P symptoms had abnormal thyroid-stimulating hormone, as opposed to 15.5% in the gastrointestinal symptom group (P = .004). Of patients with nongastrointestinal symptoms, 69.4% had anemia, compared with 11.5% of the gastrointestinal symptom group (P symptom group, 68%, were noted to have abnormal bone density scans, compared with 41% in the gastrointestinal symptom group. No sex differences were noted on chi-squared analysis between the 2 groups (P = .997). Although there is growing awareness of celiac disease, the delay in diagnosis for patients without gastrointestinal symptoms remains prolonged, with an average delay of 3.5 years. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Prospective Memory Deficits in Ecstasy Users: Effects of Longer Ongoing Task Delay Interval

    Science.gov (United States)

    WEINBORN, MICHAEL; WOODS, STEVEN PAUL; NULSEN, CLAIRE; PARK, KATHERINE

    2011-01-01

    Ecstasy use has been associated with neurotoxicity and neurocognitive impairment in a variety of domains, including prospective memory (ProM), which involves the delayed execution of a previously encoded intention in response to a specific cue. The present study adopted the multiprocess theory of ProM to evaluate the hypothesis that ecstasy users would evidence differentially impaired ProM on longer versus shorter ongoing task delays. Ecstasy (n = 31) users, high-risk alcohol users (n = 21) and healthy nonusers (n = 31) completed the short (2-min) and long (15-min) delay ProM scales of the Memory for Intentions Screening Test. Results showed a significant group by ProM delay interaction, such that ecstasy users performed comparably to the comparison groups on short-delay trials, but were impaired on long-delay ProM, particularly for time-based cues. Among the ecstasy users, long-delay ProM was positively associated with risky decision-making, but not with retrospective memory or other aspects of executive functions. These findings suggest that ecstasy users may be particularly susceptible to deficits in strategic target monitoring and maintenance of cue-intention pairings over longer ProM delays. Findings are discussed in the context of their potential everyday functioning (e.g., academic, vocational) and treatment implications for ecstasy users. PMID:22047194

  4. Cucker-Smale model with normalized communication weights and time delay

    KAUST Repository

    Choi, Young-Pil

    2017-03-06

    We study a Cucker-Smale-type system with time delay in which agents interact with each other through normalized communication weights. We construct a Lyapunov functional for the system and provide sufficient conditions for asymptotic flocking, i.e., convergence to a common velocity vector. We also carry out a rigorous limit passage to the mean-field limit of the particle system as the number of particles tends to infinity. For the resulting Vlasov-type equation we prove the existence, stability and large-time behavior of measure-valued solutions. This is, to our best knowledge, the first such result for a Vlasov-type equation with time delay. We also present numerical simulations of the discrete system with few particles that provide further insights into the flocking and oscillatory behaviors of the particle velocities depending on the size of the time delay.

  5. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design trends move towards nanometer technologies, more number of new parameters affects the delay of the component. Fuzzy delay models are ideal for modelling the uncertainty found in the design and manufacturing steps.

  6. Reconfiguration of the NRAD delay loop for proposed 1 MW operations

    International Nuclear Information System (INIS)

    Heidel, C.C.; Richards, W.J.; Pruett, D.P.

    1984-01-01

    Neutron radiography is provided by the NRAD reactor facility, which is located beneath the HFEF hot cell. The NRAD reactor is a TRIGA reactor and is operated at a steady-state power level of 250 kw solely for neutron radiography and the development of radiography techniques. When the NRAD facility was designed and constructed, an operating power level of 250 kw was considered to be adequate for obtaining radiographs of the type of specimens envisaged at that time. Since that time a second radiography station was installed and the thickness of the specimens being radiographed is greater than was initially envisaged. In order to decrease exposure times, the reactor power level is to be increased to 1 Mw. The present delay loop can not to be used at 1 Mw operation, because the passage way where the primary piping exits the reactor room must be maintained less than 1 MR/hr. To obtain the needed delay before the primary water exits the reactor room using the present internal delay loop system would require two more delay loops of the same size to be placed in series with the present delay loop. Because the NRAD reactor tank is small this is not possible; therefore, the delay must take place external to the reactor tank. The delay loop will have to be located in a shielded area to allow the decay of N 16 . The best location for the delay tank will be in the east radiography

  7. A comparison of pecking generated by serial, delay, and trace autoshaping procedures1

    Science.gov (United States)

    Newlin, Robert J.; LoLordo, Vincent M.

    1976-01-01

    Pigeons were exposed to serial, delay, and trace autoshaping procedures. In Experiment I, all conditioned stimuli (CSs) were changes in illumination of the response key. The number of trials to acquisition of the keypeck increased from serial, to 4-sec delay, 8-sec delay, and 8-sec trace procedures, in that order. In Experiment II, which used a longer intertrial interval, trials to criterion increased from 8-sec delay, to 28-sec delay, 8-sec trace, and 28-sec trace procedures, in that order. In Experiment III, two groups received serial procedures in which the first CS was either a tone or a houselight, and the second was a keylight. The tone group acquired the key peck more rapidly than the houselight group. Early in conditioning in these experiments, and when the conditioned stimulus was a change in the keylight, there was a short latency to the onset of pecking and pecking was directed at the CS. After extensive conditioning, or when the CS was relatively diffuse, pecking still occurred, but had a longer latency and was not reliably directed toward the conditioned stimulus. PMID:16811907

  8. The effect of body coloration and group size on social partner preferences in female fighting fish (Betta splendens).

    Science.gov (United States)

    Blakeslee, C; McRobert, S P; Brown, A C; Clotfelter, E D

    2009-02-01

    Females of the fighting fish Betta splendens have been shown to associate with other B. splendens females in a manner reminiscent of shoaling behavior. Since body coloration varies dramatically in this species, and since body coloration has been shown to affect shoalmate choice in other species of fish, we examined the influence of body coloration on association preferences in female B. splendens. In dichotomous choice tests, B. splendens females spent more time swimming near groups of females (regardless of coloration) than swimming near an empty chamber, and chose to swim near fish of similar coloration to their own when choosing between two distinctly colored groups of females. When examining the interplay between body coloration and group size, focal fish spent more time swimming near larger groups (N=5) of similarly colored fish than swimming near an individual female of similar coloration. However, focal fish showed no preference when presented with an individual female of similar coloration and a larger group of females of dissimilar coloration. These results suggest that association choices in B. splendens females are strongly affected by both body coloration and by group size.

  9. Operative Outcome and Patient Satisfaction in Early and Delayed Laparoscopic Cholecystectomy for Acute Cholecystitis

    Directory of Open Access Journals (Sweden)

    Aly Saber

    2014-01-01

    Full Text Available Introduction. Early laparoscopic cholecystectomy is usually associated with reduced hospital stay, sick leave, and health care expenditures. Early diagnosis and treatment of acute cholecystitis reduce both mortality and morbidity and the accurate diagnosis requires specific diagnostic criteria of clinical data and imaging studies. Objectives. To compare early versus delayed laparoscopic cholecystectomy regarding the operative outcome and patient satisfaction. Patients and Methods. Patients with acute cholecystitis were divided into two groups, early (A and delayed (B cholecystectomy. Diagnosis of acute cholecystitis was confirmed by clinical examination, laboratory data, and ultrasound study. The primary end point was operative and postoperative outcome and the secondary was patient’s satisfaction. Results. The number of readmissions in delayed treatment group B was three times in 10% of patients, twice in 23.3%, and once in 66.7% while the number of readmissions was once only in patients in group A and the mean total hospital stays were higher in group B than in group A. The overall patient’s satisfaction was 92.66±6.8 in group A compared with 75.34±12.85 in group B. Conclusion. Early laparoscopic cholecystectomy resulted in significant reduction in length of hospital stay and accepted rate of operative complications and conversion rates when compared with delayed techniques.

  10. Correlation properties of delayed neutrons from fast neutron induced fission

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Isaev, S.G.

    1998-01-01

    The experimental studies of the energy dependence of the delayed neutron parameters for various fissioning systems has shown that the behavior of a some combination of delayed neutron parameters (group relative abundances a i and half lives T i ) has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. Below we will present the preliminary results which were obtained during this study omitting the physics interpretation of the results. (author)

  11. On the cost/delay tradeoff of wireless delay tolerant geographic routing

    OpenAIRE

    Tasiopoulos, Argyrios; Tsiaras, Christos; Toumpis, Stavros

    2012-01-01

    In Delay Tolerant Networks (DTNs), there is a fundamental tradeoff between the aggregate transport cost of a packet and the delay in its delivery. We study this tradeoff in the context of geographical routing in wireless DTNs.We ?rst specify the optimal cost/delay tradeoff, i.e., the tradeoff under optimal network operation, using a dynamic network construction termed the Cost/Delay Evolving Graph (C/DEG) and the Optimal Cost/Delay Curve (OC/DC), a function that gives the minimum possible agg...

  12. Group Representations and Intergroup Bias: Positive Affect, Similarity, and Group Size.

    Science.gov (United States)

    Dovidio, John F.; And Others

    1995-01-01

    Examined how social appearance and affective factors can influence social categorization and intergroup bias. Positive affect increased the extent to which subjects formed inclusive group representations, anticipating that the members of two groups would feel like one. Subjects in dissimilarly dressed groups expected the members to feel less like…

  13. Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography

    Science.gov (United States)

    Cho, Y.; Chang, C.-C.; Wang, L. V.; Zou, J.

    2016-02-01

    This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT.

  14. Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography

    International Nuclear Information System (INIS)

    Cho, Y; Chang, C-C; Zou, J; Wang, L V

    2016-01-01

    This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT. (paper)

  15. Population size, group composition and behavioural ecology of geladas (Theropithecus gelada) and human-gelada conflict in Wonchit Valley, Ethiopia.

    Science.gov (United States)

    Kifle, Zewdu; Belay, Gurja; Bekele, Afework

    2013-11-01

    Primates that live in protected areas are intensively studied; however, those that live outside protected areas are less studied by primatologists. Therefore, the present study was carried out outside protected areas on the endemic gelada (Theropithecus gelada) to estimate the population size and group composition and human-gelada conflict in Wonchit Valley, Ethiopia from August 2008-March 2009. Total count method was used to determine the population size and group composition of geladas. A band of geladas was selected to carry out behavioural research. Data were collected on activity, diet and ranging patterns for one band of geladas using scan samples at 15 min intervals. Data on human-gelada conflict was gathered using questionnaire interview method. The total number of geladas in the study area was 1525. The average size of one-male unit was 16.96. Adult male to adult female sex ratio was 1.00:6.61. The average size of the band was 58.03. Group size ranged from 3 to 220. Geladas spent 65.2% of their time feeding, 16.3% moving, 4.6% resting and 13.9% socializing. The total time spent feeding on grass blades was 83.8% and 11.8% for bulbs and roots. The home range size was 1.5 km2 during the dry season and 0.2 km2 during the wet season. Geladas in the study area caused crop damage and shared pasture and drinking water with livestock. They consume crops during harvesting stage more than the seedling and vegetative stages. The study has immense contribution for the conservation and management of this endemic primate in unprotected areas.

  16. Proceedings of the specialists' meeting on delayed neutron nuclear data

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi

    1999-07-01

    This report is the Proceedings of the Specialists' Meeting on Delayed Neutron Nuclear Data. The meeting was held on January 28-29, 1999, at the Tokai Research Establishment of Japan Atomic Energy Research Institute with the participation of thirty specialists, who are evaluators, theorist, experimentalists. Although the fraction of the delayed neutron is no more than 1% in the total neutrons emitted in the fission process, it plays an important roll in the control of fission reactor. In the meeting, the following topics were reported: the present status of delayed neutron data in the major evaluated data libraries, measurements of effective delayed neutron fraction using FCA (Fast Critical Assembly) and TCA (Tank-type Critical Assembly) and their analyses, sensitivity analysis for fast reactor, measurements of delayed neutron emission from actinides and so on. As another topics, delayed neutron in transmutation system and fission yield data were also presented. Free discussion was held on the future activity of delayed neutron data evaluation. The discussion was helpful for the future activity of the delayed neutron working group of JNDC aiming to the evaluation of delayed neutron data for JENDL-3.3. The 15 of the presented papers are indexed individually. (J.P.N.)

  17. Early language delay phenotypes and correlation with later linguistic abilities.

    Science.gov (United States)

    Petinou, Kakia; Spanoudis, George

    2014-01-01

    The present study focused on examining the continuity and directionality of language skills in late talkers (LTs) and identifying factors which might contribute to language outcomes at the age of 3 years. Subjects were 23 Cypriot-Greek-speaking toddlers classified as LTs and 24 age-matched typically developing peers (TDs). Participants were assessed at 28, 32 and 36 months, using various linguistic measures such as size of receptive and expressive vocabulary, mean length of utterance (MLU) of words and number of consonants produced. Data on otitis media familial history were also analyzed. The ANOVA results indicated parallel developmental profiles between the two groups, with a language lag characterizing LTs. Concurrent correlations between measures showed that poor phonetic inventories in the LT group at 28 months predicted poor MLU at the ages of 32 and 36 months. Significant cross-lagged correlations supported the finding that poor phonetic inventories at 28 months served as a good predictor for MLU and expressive vocabulary at the age of 32 and for MLU at 36 months. The results highlight the negative effect of early language delay on language skills up to the age of 3 years and lend support to the current literature regarding the universal linguistic picture of early and persistent language delay. Based on the current results, poor phonetic inventories at the age of intake might serve as a predictive factor for language outcomes at the age of 36 months. Finally, the findings are discussed in view of the need for further research with a focus on more language-sensitive tools in testing later language outcomes. © 2014 S. Karger AG, Basel.

  18. The effect of topical minoxidil pretreatment on nonsurgical delay of rat cutaneous flaps: further studies.

    Science.gov (United States)

    Gümüş, Nazım; Odemiş, Yusuf; Tuncer, Ersin; Yılmaz, Sarper

    2013-08-01

    The purpose of this study was to determine the effectiveness of topically applied minoxidil in the pharmacological delay phenomenon and to demonstrate the comparable microscopic and macroscopic changes between minoxidil-pretreated flaps and surgically delayed flaps. A modified version of the McFarlane flap was used. Group 1 rats, in which a caudally based dorsal skin flap was raised and sutured back, were the control group. In group II, minoxidil solution was spread over the marked skin flap area for 7 days. On the 7th day, a caudally based dorsal skin flap was elevated and then sutured back. Group III rats underwent a surgical delay procedure alone. On the 7th day after flap elevation, evaluation was done by histologic examination and calculation of the flap survival areas in all groups. The lowest flap survival rate appeared in group I and was statistically different from groups II and III. The mean surviving skin flap area in the minoxidil-pretreated group was significantly larger than that in the control group. After histologic evaluation, moderate angiogenesis was also detected in group II. We also found that surgical delay significantly reduced flap necrosis when compared to the minoxidil pretreatment group. According to our study, minoxidil may be considered an effective vasoactive agent for the stimulation of angiogenesis in rat cutaneous flaps and capable of achieving pharmacological delay and increasing flap survival. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  19. Relating group size and posting activity of an online community of financial investors: Regularities and seasonal patterns

    Science.gov (United States)

    Racca, P.; Casarin, R.; Dondio, P.; Squazzoni, F.

    2018-03-01

    Group size can potentially affect collective activity and individual propensity to contribute to collective goods. Mancur Olson, in his Logic of Collective Action, argued that individual contribution to a collective good tends to be lower in groups of large size. Today, online communication platforms represent an interesting ground to study such collaborative dynamics under possibly different conditions (e.g., lower costs related to gather and share information). This paper examines the relationship between group size and activity in an online financial forum, where users invest time in sharing news, analysis and comments with other investors. We looked at about 24 million messages shared in more than ten years in the finanzaonline.com online forum. We found that the relationship between the number of active users and the number of posts shared by those users is of the power type (with exponent α > 1) and is subject to periodic fluctuations, mostly driven by hour-of-the-day and day-of-the-week effects. The daily patterns of the exponent showed a divergence between working week and weekend days. In general, the exponent was lower before noon, where investors are typically interested in market news, higher in the late afternoon, where markets are closing and investors need better understanding of the situation. Further research is needed, especially at the micro level, to dissect the mechanisms behind these regularities.

  20. Is delayed surgery related to worse outcomes in native left-sided endocarditis?

    Science.gov (United States)

    Tepsuwan, Thitipong; Rimsukcharoenchai, Chartaroon; Tantraworasin, Apichat; Woragidpoonpol, Surin; Schuarattanapong, Suphachai; Nawarawong, Weerachai

    2016-05-01

    Timing of surgery in the management of infective endocarditis is controversial, and there is still no definite conclusion on how early the surgery should be performed. This study focuses on the outcomes of surgery during the active period of infective endocarditis in consideration of the duration after diagnosis. One hundred and thirty-four patients with active native valve infective endocarditis who underwent surgery from January 2006 to December 2013 were reviewed retrospectively. They were divided in 2 groups based on timing of surgery: early group (first week after diagnosis, n = 37) and delayed group (2 to 6 weeks after diagnosis, n = 97). Compared to the delayed group, the early group had significantly more patients in New York Heart Association class IV (81% vs. 43.3%), more mechanically ventilated (54.1% vs. 18.6%), more on inotropic support (62.2% vs. 38.1%), and hence a worse EuroSCORE II (14.8% vs. 8.8%). Operative mortality was comparable (5.4% vs. 10.3%) and 7-year survival was similar (77.4% vs. 74.6%). On multivariable regression analysis, delayed surgery did not impact on short- and long-term outcomes. Preoperative cardiac arrest and infection with Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, or Kingella were risk factors for higher operative mortality. Predictors of poor 7-year survival were diabetes mellitus and acute renal failure. Delayed surgery is not associated with worse outcomes. Both early and delayed approaches are safe and provide acceptable results. Timing of surgery should be tailored to each patient's clinical status, not based on duration of endocarditis alone. © The Author(s) 2016.

  1. Leveraging delay discounting for health: Can time delays influence food choice?

    Science.gov (United States)

    Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

    2018-03-15

    Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Terrestrial Sagnac delay constraining modified gravity models

    Science.gov (United States)

    Karimov, R. Kh.; Izmailov, R. N.; Potapov, A. A.; Nandi, K. K.

    2018-04-01

    Modified gravity theories include f(R)-gravity models that are usually constrained by the cosmological evolutionary scenario. However, it has been recently shown that they can also be constrained by the signatures of accretion disk around constant Ricci curvature Kerr-f(R0) stellar sized black holes. Our aim here is to use another experimental fact, viz., the terrestrial Sagnac delay to constrain the parameters of specific f(R)-gravity prescriptions. We shall assume that a Kerr-f(R0) solution asymptotically describes Earth's weak gravity near its surface. In this spacetime, we shall study oppositely directed light beams from source/observer moving on non-geodesic and geodesic circular trajectories and calculate the time gap, when the beams re-unite. We obtain the exact time gap called Sagnac delay in both cases and expand it to show how the flat space value is corrected by the Ricci curvature, the mass and the spin of the gravitating source. Under the assumption that the magnitude of corrections are of the order of residual uncertainties in the delay measurement, we derive the allowed intervals for Ricci curvature. We conclude that the terrestrial Sagnac delay can be used to constrain the parameters of specific f(R) prescriptions. Despite using the weak field gravity near Earth's surface, it turns out that the model parameter ranges still remain the same as those obtained from the strong field accretion disk phenomenon.

  3. Numerical Hopf bifurcation of Runge-Kutta methods for a class of delay differential equations

    International Nuclear Information System (INIS)

    Wang Qiubao; Li Dongsong; Liu, M.Z.

    2009-01-01

    In this paper, we consider the discretization of parameter-dependent delay differential equation of the form y ' (t)=f(y(t),y(t-1),τ),τ≥0,y element of R d . It is shown that if the delay differential equation undergoes a Hopf bifurcation at τ=τ * , then the discrete scheme undergoes a Hopf bifurcation at τ(h)=τ * +O(h p ) for sufficiently small step size h, where p≥1 is the order of the Runge-Kutta method applied. The direction of numerical Hopf bifurcation and stability of bifurcating invariant curve are the same as that of delay differential equation.

  4. Hippocampus, delay discounting, and vicarious trial-and-error.

    Science.gov (United States)

    Bett, David; Murdoch, Lauren H; Wood, Emma R; Dudchenko, Paul A

    2015-05-01

    In decision-making, an immediate reward is usually preferred to a delayed reward, even if the latter is larger. We tested whether the hippocampus is necessary for this form of temporal discounting, and for vicarious trial-and-error at the decision point. Rats were trained on a recently developed, adjustable delay-discounting task (Papale et al. (2012) Cogn Affect Behav Neurosci 12:513-526), which featured a choice between a small, nearly immediate reward, and a larger, delayed reward. Rats then received either hippocampus or sham lesions. Animals with hippocampus lesions adjusted the delay for the larger reward to a level similar to that of sham-lesioned animals, suggesting a similar valuation capacity. However, the hippocampus lesion group spent significantly longer investigating the small and large rewards in the first part of the sessions, and were less sensitive to changes in the amount of reward in the large reward maze arm. Both sham- and hippocampus-lesioned rats showed a greater amount of vicarious trial-and-error on trials in which the delay was adjusted. In a nonadjusting version of the delay discounting task, animals with hippocampus lesions showed more variability in their preference for a larger reward that was delayed by 10 s compared with sham-lesioned animals. To verify the lesion behaviorally, rat were subsequently trained on a water maze task, and rats with hippocampus lesions were significantly impaired compared with sham-lesioned animals. The findings on the delay discounting tasks suggest that damage to the hippocampus may impair the detection of reward magnitude. © 2014 Wiley Periodicals, Inc.

  5. Perception of Construction Participants in Construction delays: A case study in Tamilnadu, India.

    Science.gov (United States)

    Rathinakumar, V.; Vignesh, T.; Dhivagar, K.

    2017-07-01

    Delays in the construction industry are universal fact, which affects the construction participants. The research work spotlights on determining the prevailing delays in the cities of Tamil Nadu, as perceived by the participants. After a few field level interactions, a questionnaire was framed and administered to the participants i.e., Consultants (50 Nos.), contractors (50 Nos.) and clients (150 Nos.) to understand their perception on the causes of delays. The factors for delay was categorized into 4 groups say Improper project planning, Design related issues, Finance related issues and Resource related issues. The responses were analysed using the SPSS software by applying ANOVA and Regression analysis. From the analysis, it was found that the personal financial problems of the client dominantly affect the entire construction progress and the subsequent design changes by the clients, Inadequate early project planning, labour related issues. Also, the delay groups were found to be the improper project planning and the Resource related issues.

  6. Taurine supplementation attenuates delayed increase in exercise-induced arterial stiffness.

    Science.gov (United States)

    Ra, Song-Gyu; Choi, Youngju; Akazawa, Nobuhiko; Ohmori, Hajime; Maeda, Seiji

    2016-06-01

    There is a delayed increase in arterial stiffness after eccentric exercise that is possibly mediated by the concurrent delayed increase in circulating oxidative stress. Taurine has anti-oxidant action, and taurine supplementation may be able to attenuate the increase in oxidative stress after exercise. The purpose of the present study was to investigate whether taurine supplementation attenuates the delayed increase in arterial stiffness after eccentric exercise. In the present double-blind, randomized, and placebo-controlled trial, we divided 29 young, healthy men into 2 groups. Subjects received either 2.0 g of placebo (n = 14) or taurine (n = 15) 3 times per day for 14 days prior to the exercise, on the day of exercise, and the following 3 days. The exercise consisted of 2 sets of 20 maximal-effort eccentric repetitions with the nondominant arm only. On the morning of exercise and for 4 days thereafter, we measured serum malondialdehyde (MDA) and carotid-femoral pulse wave velocity (cfPWV) as indices of oxidative stress and arterial stiffness, respectively. On the third and fourth days after exercise, both MDA and cfPWV significantly increased in the placebo group. However, these elevations were significantly attenuated in the taurine group. The increase in MDA was associated with an increase in cfPWV from before exercise to 4 days after exercise (r = 0.597, p taurine group. Our results suggest that delayed increase in arterial stiffness after eccentric exercise was probably affected by the exercise-induced oxidative stress and was attenuated by the taurine supplementation.

  7. Representing delayed force feedback as a combination of current and delayed states.

    Science.gov (United States)

    Avraham, Guy; Mawase, Firas; Karniel, Amir; Shmuelof, Lior; Donchin, Opher; Mussa-Ivaldi, Ferdinando A; Nisky, Ilana

    2017-10-01

    To adapt to deterministic force perturbations that depend on the current state of the hand, internal representations are formed to capture the relationships between forces experienced and motion. However, information from multiple modalities travels at different rates, resulting in intermodal delays that require compensation for these internal representations to develop. To understand how these delays are represented by the brain, we presented participants with delayed velocity-dependent force fields, i.e., forces that depend on hand velocity either 70 or 100 ms beforehand. We probed the internal representation of these delayed forces by examining the forces the participants applied to cope with the perturbations. The findings showed that for both delayed forces, the best model of internal representation consisted of a delayed velocity and current position and velocity. We show that participants relied initially on the current state, but with adaptation, the contribution of the delayed representation to adaptation increased. After adaptation, when the participants were asked to make movements with a higher velocity for which they had not previously experienced with the delayed force field, they applied forces that were consistent with current position and velocity as well as delayed velocity representations. This suggests that the sensorimotor system represents delayed force feedback using current and delayed state information and that it uses this representation when generalizing to faster movements. NEW & NOTEWORTHY The brain compensates for forces in the body and the environment to control movements, but it is unclear how it does so given the inherent delays in information transmission and processing. We examined how participants cope with delayed forces that depend on their arm velocity 70 or 100 ms beforehand. After adaptation, participants applied opposing forces that revealed a partially correct representation of the perturbation using the current and the

  8. Typical versus delayed speech onset influences verbal reporting of autistic interests.

    Science.gov (United States)

    Chiodo, Liliane; Majerus, Steve; Mottron, Laurent

    2017-01-01

    The distinction between autism and Asperger syndrome has been abandoned in the DSM-5. However, this clinical categorization largely overlaps with the presence or absence of a speech onset delay which is associated with clinical, cognitive, and neural differences. It is unknown whether these different speech development pathways and associated cognitive differences are involved in the heterogeneity of the restricted interests that characterize autistic adults. This study tested the hypothesis that speech onset delay, or conversely, early mastery of speech, orients the nature and verbal reporting of adult autistic interests. The occurrence of a priori defined descriptors for perceptual and thematic dimensions were determined, as well as the perceived function and benefits, in the response of autistic people to a semi-structured interview on their intense interests. The number of words, grammatical categories, and proportion of perceptual / thematic descriptors were computed and compared between groups by variance analyses. The participants comprised 40 autistic adults grouped according to the presence ( N  = 20) or absence ( N  = 20) of speech onset delay, as well as 20 non-autistic adults, also with intense interests, matched for non-verbal intelligence using Raven's Progressive Matrices. The overall nature, function, and benefit of intense interests were similar across autistic subgroups, and between autistic and non-autistic groups. However, autistic participants with a history of speech onset delay used more perceptual than thematic descriptors when talking about their interests, whereas the opposite was true for autistic individuals without speech onset delay. This finding remained significant after controlling for linguistic differences observed between the two groups. Verbal reporting, but not the nature or positive function, of intense interests differed between adult autistic individuals depending on their speech acquisition history: oral reporting of

  9. Anomalous group velocity at the high energy range of real 3D photonic nanostructures

    Science.gov (United States)

    Botey, Muriel; Martorell, Jordi; Lozano, Gabriel; Míguez, Hernán; Dorado, Luis A.; Depine, Ricardo A.

    2010-05-01

    We perform a theoretical study on the group velocity for finite thin artificial opal slabs made of a reduced number of layers in the spectral range where the light wavelength is on the order of the lattice parameter. The vector KKR method including extinction allows us to evaluate the finite-size effects on light propagation in the ΓL and ΓX directions of fcc close-packed opal films made of dielectric spheres. The group is index determined from the phase delay introduced by the structure to the forwardly transmitted electric field. We show that for certain frequencies, light propagation can either be superluminal -positive or negative- or approach zero depending on the crystal size and absorption. Such anomalous behavior can be attributed to the finite character of the structure and provides confirmation of recently emerged experimental results.

  10. Teaching self-control to small groups of dually diagnosed adults.

    OpenAIRE

    Dixon, M R; Holcomb, S

    2000-01-01

    The present study examined the use of a progressive delay procedure to teach self-control to two groups of dually diagnosed adults. When given a choice between an immediate smaller reinforcer and a larger delayed reinforcer, both groups chose the smaller reinforcer during baseline. During treatment, progressive increases in work requirements for gaining access to a larger reinforcer resulted in both groups selecting larger delayed reinforcers. The results are discussed with respect to increas...

  11. Prospective randomized study of arthroscopic rotator cuff repair using an early versus delayed postoperative physical therapy protocol.

    Science.gov (United States)

    Cuff, Derek J; Pupello, Derek R

    2012-11-01

    This study evaluated patient outcomes and rotator cuff healing after arthroscopic rotator cuff repair using a postoperative physical therapy protocol with early passive motion compared with a delayed protocol that limited early passive motion. The study enrolled 68 patients (average age, 63.2 years) who met inclusion criteria. All patients had a full-thickness crescent-shaped tear of the supraspinatus that was repaired using a transosseous equivalent suture-bridge technique along with subacromial decompression. In the early group, 33 patients were randomized to passive elevation and rotation that began at postoperative day 2. In the delayed group, 35 patients began the same protocol at 6 weeks. Patients were monitored clinically for a minimum of 12 months, and rotator cuff healing was assessed using ultrasound imaging. Both groups had similar improvements in preoperative to postoperative American Shoulder and Elbow Surgeons scores (early group: 43.9 to 91.9, P rotator cuff healing, or range of motion between the early and delayed groups. Patients in the early group and delayed group both demonstrated very similar outcomes and range of motion at 1 year. There was a slightly higher rotator cuff healing rate in the delayed passive range of motion group compared with the early passive range of motion group (91% vs 85%). Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  12. The Relationships among Group Size, Participation, and Performance of Programming Language Learning Supported with Online Forums

    Science.gov (United States)

    Shaw, Ruey-Shiang

    2013-01-01

    This study examined the relationships among group size, participation, and learning performance factors when learning a programming language in a computer-supported collaborative learning (CSCL) context. An online forum was used as the CSCL environment for learning the Microsoft ASP.NET programming language. The collaborative-learning experiment…

  13. Delayed-onset dementia after stroke or transient ischemic attack.

    Science.gov (United States)

    Mok, Vincent C T; Lam, Bonnie Y K; Wang, Zhaolu; Liu, Wenyan; Au, Lisa; Leung, Eric Y L; Chen, Sirong; Yang, Jie; Chu, Winnie C W; Lau, Alexander Y L; Chan, Anne Y Y; Shi, Lin; Fan, Florence; Ma, Sze H; Ip, Vincent; Soo, Yannie O Y; Leung, Thomas W H; Kwok, Timothy C Y; Ho, Chi L; Wong, Lawrence K S; Wong, Adrian

    2016-11-01

    Patients surviving stroke without immediate dementia are at high risk of delayed-onset dementia. Mechanisms underlying delayed-onset dementia are complex and may involve vascular and/or neurodegenerative diseases. Dementia-free patients with stroke and/or transient ischemic attack (TIA; n = 919) were studied for 3 years prospectively, excluding those who developed dementia 3 to 6 months after stroke and/or TIA. Forty subjects (4.4%) developed dementia during the study period. Imaging markers of severe small vessel disease (SVD), namely presence of ≥3 lacunes and confluent white matter changes; history of hypertension and diabetes mellitus independently predicted delayed-onset dementia after adjustment for age, gender, and education. Only 6 of 31 (19.4%) subjects with delayed cognitive decline harbored Alzheimer's disease-like Pittsburg compound B (PiB) retention. Most PiB cases (16/25, 64%) had evidence of severe SVD. Severe SVD contributes importantly to delayed-onset dementia after stroke and/or TIA. Future clinical trials aiming to prevent delayed-onset dementia after stroke and/or TIA should target this high-risk group. Copyright © 2016 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  14. The effectiveness of parent participation in occupational therapy for children with developmental delay

    Directory of Open Access Journals (Sweden)

    Lin CL

    2018-02-01

    Full Text Available Chien-Lin Lin1,2 Chin-Kai Lin,3 Jia-Jhen Yu4 1Department of Physical Medicine and Rehabilitation, China Medical University Hospital, 2School of Chinese Medicine, College of Chinese Medicine, China Medical University, 3Program of Early Intervention, Department of Early Childhood Education, National Taichung University of Education, 4Occupation Therapy Unit of Rehabilitation Techniques Section, Lin Shin Medical Corporation Wuri Lin Shin Hospital, Taichung, Taiwan Introduction: This study aims to explore the impact of Parent Participation Program on the development of developmental delay children. Methods: Pretest-posttest equivalent-group experimental design study was used in this paper. A total of 30 pairs of developmental delay children aged 0–72 months and their parents participated into this study. They were divided into two groups, namely control group and experimental group, according to parents’ wishes. The objects of study in control group received 16 courses of direct rehabilitation therapy; those in experimental group received 8 courses of direct rehabilitation therapy and 8 courses of instruction and tracking of Parent Participation Program. The duration of the intervention was 8 weeks. All cases should be evaluated before and after the intervention, to analyze the difference before and after intervention and among groups. The statistical methods in this paper included descriptive analysis, Chi-square test, independent sample t-test, pair-sample t-test. Results and conclusion: The intervention of Parent Participation Occupational Program has positive impact on the development of developmental delay children in various fields. Among all the intervention results, the progress of the experimental group is 1.895 times more than that of the control group. With parent involvement, Parent Participation Occupational Therapy can promote the cognitive ability, language ability, action ability (gross and fine movement, social competence and

  15. Treatment-time-dependence models of early and delayed radiation injury in rat small intestine

    International Nuclear Information System (INIS)

    Denham, James W.; Hauer-Jensen, Martin; Kron, Tomas; Langberg, Carl W.

    2000-01-01

    Background: The present study modeled data from a large series of experiments originally designed to investigate the influence of time, dose, and fractionation on early and late pathologic endpoints in rat small intestine after localized irradiation. The objective was to obtain satisfactory descriptions of the regenerative response to injury together with the possible relationships between early and late endpoints. Methods: Two- and 26-week pathologic radiation injury data in groups of Sprague-Dawley rats irradiated with 27 different fractionation schedules were modeled using the incomplete repair (IR) version of the linear-quadratic model with or without various time correction models. The following time correction models were tested: (1) No time correction; (2) A simple exponential (SE) regenerative response beginning at an arbitrary time after starting treatment; and (3) A bi-exponential response with its commencement linked to accumulated cellular depletion and fraction size (the 'intelligent response model' [INTR]). Goodness of fit of the various models was assessed by correlating the predicted biological effective dose for each dose group with the observed radiation injury score. Results: (1) The incomplete repair model without time correction did not provide a satisfactory description of either the 2- or 26-week data. (2) The models using SE time correction performed better, providing modest descriptions of the data. (3) The INTR model provided reasonable descriptions of both the 2- and 26-week data, confirming a treatment time dependence of both early and late pathological endpoints. (4) The most satisfactory descriptions of the data by the INTR model were obtained when the regenerative response was assumed to cease 2 weeks after irradiation rather than at the end of irradiation. A fraction-size-dependent delay of the regenerative response was also suggested in the best fitting models. (5) Late endpoints were associated with low-fractionation sensitivity

  16. Measurement of time delays in gated radiotherapy for realistic respiratory motions

    International Nuclear Information System (INIS)

    Chugh, Brige P.; Quirk, Sarah; Conroy, Leigh; Smith, Wendy L.

    2014-01-01

    Purpose: Gated radiotherapy is used to reduce internal motion margins, escalate target dose, and limit normal tissue dose; however, its temporal accuracy is limited. Beam-on and beam-off time delays can lead to treatment inefficiencies and/or geographic misses; therefore, AAPM Task Group 142 recommends verifying the temporal accuracy of gating systems. Many groups use sinusoidal phantom motion for this, under the tacit assumption that use of sinusoidal motion for determining time delays produces negligible error. The authors test this assumption by measuring gating time delays for several realistic motion shapes with increasing degrees of irregularity. Methods: Time delays were measured on a linear accelerator with a real-time position management system (Varian TrueBeam with RPM system version 1.7.5) for seven motion shapes: regular sinusoidal; regular realistic-shape; large (40%) and small (10%) variations in amplitude; large (40%) variations in period; small (10%) variations in both amplitude and period; and baseline drift (30%). Film streaks of radiation exposure were generated for each motion shape using a programmable motion phantom. Beam-on and beam-off time delays were determined from the difference between the expected and observed streak length. Results: For the system investigated, all sine, regular realistic-shape, and slightly irregular amplitude variation motions had beam-off and beam-on time delays within the AAPM recommended limit of less than 100 ms. In phase-based gating, even small variations in period resulted in some time delays greater than 100 ms. Considerable time delays over 1 s were observed with highly irregular motion. Conclusions: Sinusoidal motion shapes can be considered a reasonable approximation to the more complex and slightly irregular shapes of realistic motion. When using phase-based gating with predictive filters even small variations in period can result in time delays over 100 ms. Clinical use of these systems for patients

  17. Measurement of time delays in gated radiotherapy for realistic respiratory motions

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Brige P.; Quirk, Sarah; Conroy, Leigh; Smith, Wendy L., E-mail: Wendy.Smith@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada)

    2014-09-15

    Purpose: Gated radiotherapy is used to reduce internal motion margins, escalate target dose, and limit normal tissue dose; however, its temporal accuracy is limited. Beam-on and beam-off time delays can lead to treatment inefficiencies and/or geographic misses; therefore, AAPM Task Group 142 recommends verifying the temporal accuracy of gating systems. Many groups use sinusoidal phantom motion for this, under the tacit assumption that use of sinusoidal motion for determining time delays produces negligible error. The authors test this assumption by measuring gating time delays for several realistic motion shapes with increasing degrees of irregularity. Methods: Time delays were measured on a linear accelerator with a real-time position management system (Varian TrueBeam with RPM system version 1.7.5) for seven motion shapes: regular sinusoidal; regular realistic-shape; large (40%) and small (10%) variations in amplitude; large (40%) variations in period; small (10%) variations in both amplitude and period; and baseline drift (30%). Film streaks of radiation exposure were generated for each motion shape using a programmable motion phantom. Beam-on and beam-off time delays were determined from the difference between the expected and observed streak length. Results: For the system investigated, all sine, regular realistic-shape, and slightly irregular amplitude variation motions had beam-off and beam-on time delays within the AAPM recommended limit of less than 100 ms. In phase-based gating, even small variations in period resulted in some time delays greater than 100 ms. Considerable time delays over 1 s were observed with highly irregular motion. Conclusions: Sinusoidal motion shapes can be considered a reasonable approximation to the more complex and slightly irregular shapes of realistic motion. When using phase-based gating with predictive filters even small variations in period can result in time delays over 100 ms. Clinical use of these systems for patients

  18. Optimal Placement of Actors in WSANs Based on Imposed Delay Constraints

    Directory of Open Access Journals (Sweden)

    Chunxi Yang

    2014-01-01

    Full Text Available Wireless Sensor and Actor Networks (WSANs refer to a group of sensors and actors linked by wireless medium to probe environment and perform specific actions. Such certain actions should always be taken before a deadline when an event of interest is detected. In order to provide such services, the whole monitor area is divided into several virtual areas and nodes in the same area form a cluster. Clustering of the WSANs is often pursued to give that each actor acts as a cluster-head. The number of actors is related to the size and the deployment of WSANs cluster. In this paper, we find a method to determine the accurate number of actors which enables them to receive data and take actions in an imposed time-delay. The k-MinTE and the k-MaxTE clustering algorithm are proposed to form the minimum and maximum size of cluster, respectively. In those clustering algorithms, actors are deployed in such a way that sensors could route data to actors within k hops. Then, clusters are arranged by the regular hexagon. At last, we evaluate the placement of actors and results show that our approach is effective.

  19. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  20. Maternal and Neonatal Outcomes With Early Compared With Delayed Pushing Among Nulliparous Women.

    Science.gov (United States)

    Yee, Lynn M; Sandoval, Grecio; Bailit, Jennifer; Reddy, Uma M; Wapner, Ronald J; Varner, Michael W; Caritis, Steve N; Prasad, Mona; Tita, Alan T N; Saade, George; Sorokin, Yoram; Rouse, Dwight J; Blackwell, Sean C; Tolosa, Jorge E

    2016-11-01

    To describe factors associated with delayed pushing and evaluate the relationship between delayed pushing and perinatal outcomes in nulliparous women with singleton term gestations. This was a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Assessment of Perinatal Excellence cohort of 115,502 women and their neonates born in 25 U.S. hospitals from 2008 to 2011. Nulliparous women with singleton, cephalic, nonanomalous term births who achieved 10-cm cervical dilation were included. Women in whom pushing was delayed by 60 minutes or greater (delayed group) were compared with those who initiated pushing within 30 minutes (early group). Multivariable regression analyses were used to assess the independent association of delayed pushing with mode of delivery, length of the second stage, and other maternal and perinatal outcomes (significance defined as Ppushing was delayed in 18.4% (n=3,870). Women who were older, privately insured, or non-Hispanic white as well as those who had induction or augmentation of labor, diabetes, or epidural analgesia were more likely to have delayed pushing. Delayed pushing was more common when the second stage began during daytime hours or in hospitals with dedicated 24-hour obstetric anesthesia, although differences were small. After adjusting for differences in baseline and labor characteristics including center, women in the delayed group had longer mean durations of the second stage (191 compared with 84 minutes, Ppushing (86 compared with 76 minutes, Ppushing was associated with greater rates of cesarean delivery (11.2% compared with 5.1%; adjusted odds ratio [OR] 1.86, 95% confidence interval [CI] 1.63-2.12), operative vaginal delivery (adjusted OR 1.26, 95% CI 1.14-1.40), postpartum hemorrhage (adjusted OR 1.43, 95% CI 1.05-1.95), and blood transfusion (adjusted OR 1.51, 95% CI 1.04-2.17). Delayed pushing was not associated with increased odds of adverse neonatal outcomes

  1. Truncated predictor feedback for time-delay systems

    CERN Document Server

    Zhou, Bin

    2014-01-01

    This book provides a systematic approach to the design of predictor based controllers for (time-varying) linear systems with either (time-varying) input or state delays. Differently from those traditional predictor based controllers, which are infinite-dimensional static feedback laws and may cause difficulties in their practical implementation, this book develops a truncated predictor feedback (TPF) which involves only finite dimensional static state feedback. Features and topics: A novel approach referred to as truncated predictor feedback for the stabilization of (time-varying) time-delay systems in both the continuous-time setting and the discrete-time setting is built systematically Semi-global and global stabilization problems of linear time-delay systems subject to either magnitude saturation or energy constraints are solved in a systematic manner Both stabilization of a single system and consensus of a group of systems (multi-agent systems) are treated in a unified manner by applying the truncated pre...

  2. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color.

    Science.gov (United States)

    Canton, Jillian L; Smith, Mark R; Choi, Ho-Sun; Eastman, Charmane I

    2009-07-17

    Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Subjects (blue-eyed n = 7; brown eyed n = 6) maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO). Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux). An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline). A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment.Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. The average phase delay of the DLMO was -1.3 +/- 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. A single 2-hour bright light pulse combined with a moderate delay of the sleep/dark episode

  3. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color

    Directory of Open Access Journals (Sweden)

    Choi Ho-Sun

    2009-07-01

    Full Text Available Abstract Background Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Methods Subjects (blue-eyed n = 7; brown eyed n = 6 maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO. Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux. An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline. A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment. Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. Results The average phase delay of the DLMO was -1.3 ± 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. Conclusion A single 2-hour bright light

  4. Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size

    Science.gov (United States)

    King, Richard B.

    2016-01-01

    Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females) and annual growth increments of individuals of unknown age (1,152 males, 730 females). We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631–820 mm snout-vent length in males and from 835–1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further investigation. PMID

  5. Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size.

    Directory of Open Access Journals (Sweden)

    Richard B King

    Full Text Available Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females and annual growth increments of individuals of unknown age (1,152 males, 730 females. We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631-820 mm snout-vent length in males and from 835-1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further

  6. Sunscreens for delay of ultraviolet induction of skin tumors

    International Nuclear Information System (INIS)

    Wulf, H.C.; Poulsen, T.; Brodthagen, H.; Hou-Jensen, K.

    1982-01-01

    Sunscreens with different sun protection factors (SPFs) have been tested for their capability of delaying or preventing actinic damage and skin cancer development in groups of hairless, pigmented mice exposed to artificial ultraviolet (UV) light of increasing intensity. The dose delivered was less than or equal to 1 minimal erythema dose (MED) in the group of untreated mice, so that the mice to which sunscreens were applied never obtained a sunburn after UV exposure. The quality of UV light was similar to bright midday sun at a latitude of 56 degrees (city of Copenhagen). Tumorigenesis was demonstrated to be delayed corresponding to the SPF claimed by the manufacturer, but almost all of the UV-irradiated mice developed skin tumors. Histologic examination revealed actinic degeneration and tumors of squamous cell type with marked variation in differentiation. Metastases to lymph nodes and lungs were found in only 10%. Toxic reactions, such as eczematous-like skin reactions, dark coloring, and amyloidosis, were observed predominantly in the group treated with the sunscreen of highest SPF value. Long-term investigations seem to be necessary to unveil these problems--in particular, the specific SPF value, in sunscreens, that should be recommended to the public for prevention or delay of actinic damage and/or cancer development

  7. Integrating the ACR Appropriateness Criteria Into the Radiology Clerkship: Comparison of Didactic Format and Group-Based Learning.

    Science.gov (United States)

    Stein, Marjorie W; Frank, Susan J; Roberts, Jeffrey H; Finkelstein, Malka; Heo, Moonseong

    2016-05-01

    The aim of this study was to determine whether group-based or didactic teaching is more effective to teach ACR Appropriateness Criteria to medical students. An identical pretest, posttest, and delayed multiple-choice test was used to evaluate the efficacy of the two teaching methods. Descriptive statistics comparing test scores were obtained. On the posttest, the didactic group gained 12.5 points (P didactic group gained 14.4 points (P didactic lectures, group-based learning is more enjoyable, time efficient, and equally efficacious. The choice of educational method can be individualized for each institution on the basis of group size, time constraints, and faculty availability. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Factors associated with long diagnostic delay in celiac disease.

    Science.gov (United States)

    Fuchs, Valma; Kurppa, Kalle; Huhtala, Heini; Collin, Pekka; Mäki, Markku; Kaukinen, Katri

    2014-11-01

    Here, we investigated the factors associated with long diagnostic delay in celiac disease and the impact of the national Current Care Guidelines in reducing the delay. This population-based study involved 825 adult celiac disease patients. The diagnosis was considered delayed when the interval between first symptoms and diagnosis was >10 years. The patients were asked about the duration and type of symptoms before diagnosis, time and site (tertiary, secondary, or primary care) of the diagnosis, family history of the disease, and presence of significant comorbidities. Analysis was performed by binary logistic regression. Altogether, 261 (32%) out of 825 participants reported a diagnostic delay of >10 years. Female gender, neurological or musculoskeletal disorders and presence of diarrhea, abdominal pain, and malabsorption were associated with prolonged delay. Male gender, diagnosis after the introduction of the first Current Care Guidelines in 1997, and being detected by serological screening, and family history of celiac disease were associated with a lower risk of delayed diagnosis. Factors not associated with the delay were site of diagnosis, age, and presence of dermatitis herpetiformis, type 1 diabetes, or thyroidal disease. The number of long diagnostic delays in celiac disease has decreased over the past decades. The shift of diagnostics from secondary and tertiary care to primary care has not been detrimental. National guidelines together with increased awareness and active screening in at-risk groups of celiac disease are important in these circumstances.

  9. Observations on early and delayed colostomy closure.

    Science.gov (United States)

    Tade, A O; Salami, B A; Ayoade, B A

    2011-06-01

    Traditional treatment of a variety of colorectal pathologies had included a diverting colostomy that was closed eight or more weeks later during a readmission. The aim of this retrospective study was to determine the outcomes of early colostomy closure and delayed colostomy closure in patients with temporary colostomies following traumatic and non-traumatic colorectal pathologies. In this study early colostomy closure was the closure of a colostomy within three weeks of its construction, while delayed colostomy closure referred to closure after 3 weeks. Complete records of the 37 adult patients who had temporary colostomy constructed and closed between Jan. 1997 December 2003 for various colorectal pathologies were studied. Fourteen patients had early colostomy closure while 23 had delayed closure. In the early colostomy closure group there were 10 men and 4 women. The mean age of the patients was 28yr with a range of 18-65yr. Colostomies were closed 9-18 days after initial colostomy construction. There was no mortality. Morbidity rate 28.6% (4 out of 14). There were two faecal fistulas (14.3%). Twenty-three patients had delayed colostomy closure 8 weeks to 18 months after initial colostomy construction. These were patients unfit for early surgery after initial colostomy construction because of carcinoma, significant weight loss, or sepsis. There was no mortality. Morbidity rate was 26.1%. There were 3 faecal fistulas (13.2%). Outcomes following early colostomy closure and delayed closure were comparable. Patients fit for surgery should have early closure whilst patients who may have compromised health should have delayed closure.

  10. Estimation of time-delayed mutual information and bias for irregularly and sparsely sampled time-series

    International Nuclear Information System (INIS)

    Albers, D.J.; Hripcsak, George

    2012-01-01

    Highlights: ► Time-delayed mutual information for irregularly sampled time-series. ► Estimation bias for the time-delayed mutual information calculation. ► Fast, simple, PDF estimator independent, time-delayed mutual information bias estimate. ► Quantification of data-set-size limits of the time-delayed mutual calculation. - Abstract: A method to estimate the time-dependent correlation via an empirical bias estimate of the time-delayed mutual information for a time-series is proposed. In particular, the bias of the time-delayed mutual information is shown to often be equivalent to the mutual information between two distributions of points from the same system separated by infinite time. Thus intuitively, estimation of the bias is reduced to estimation of the mutual information between distributions of data points separated by large time intervals. The proposed bias estimation techniques are shown to work for Lorenz equations data and glucose time series data of three patients from the Columbia University Medical Center database.

  11. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design .... To find the quality of non-robust tests, a fuzzy delay ..... Dubois D and Prade H 1989 Processing Fuzzy temporal knowledge. IEEE Transactions ...

  12. Effect of delayed auditory feedback on stuttering with and without central auditory processing disorders.

    Science.gov (United States)

    Picoloto, Luana Altran; Cardoso, Ana Cláudia Vieira; Cerqueira, Amanda Venuti; Oliveira, Cristiane Moço Canhetti de

    2017-12-07

    To verify the effect of delayed auditory feedback on speech fluency of individuals who stutter with and without central auditory processing disorders. The participants were twenty individuals with stuttering from 7 to 17 years old and were divided into two groups: Stuttering Group with Auditory Processing Disorders (SGAPD): 10 individuals with central auditory processing disorders, and Stuttering Group (SG): 10 individuals without central auditory processing disorders. Procedures were: fluency assessment with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF), assessment of the stuttering severity and central auditory processing (CAP). Phono Tools software was used to cause a delay of 100 milliseconds in the auditory feedback. The "Wilcoxon Signal Post" test was used in the intragroup analysis and "Mann-Whitney" test in the intergroup analysis. The DAF caused a statistically significant reduction in SG: in the frequency score of stuttering-like disfluencies in the analysis of the Stuttering Severity Instrument, in the amount of blocks and repetitions of monosyllabic words, and in the frequency of stuttering-like disfluencies of duration. Delayed auditory feedback did not cause statistically significant effects on SGAPD fluency, individuals with stuttering with auditory processing disorders. The effect of delayed auditory feedback in speech fluency of individuals who stutter was different in individuals of both groups, because there was an improvement in fluency only in individuals without auditory processing disorder.

  13. Tracheobronchial foreign bodies in children: importance of accurate history and plain chest radiography in delayed presentation

    Energy Technology Data Exchange (ETDEWEB)

    Tokar, B. E-mail: btokar@ogu.edu.trbarantokar@hotmail.com; Ozkan, R.; Ilhan, H

    2004-07-01

    AIM: To evaluate the factors associated with delayed diagnosis of foreign body aspiration (FBA) in children and to compare clinical, radiological and bronchoscopic findings in the patients with suspected FBA. MATERIAL AND METHODS: The medical records of 214 children who underwent bronchoscopy for suspected FBA were reviewed. The data were analysed in three groups: the patients with negative bronchoscopy for FBA (group I), early (group II) and delayed diagnosis (group III). RESULTS: The majority of the patients with FBA were between 1 and 3 years of age. Choking episodes, coughing and decreased breath sounds were determined in a significantly higher number of the patients with FBA. The plain chest radiography revealed radio-opaque foreign bodies (FBs) in 19.7% of all patients with FBA. Emphysema was more common in children with FBA. Clinical and radiological findings of pneumonia and atelectasis were significantly more common in the groups with negative bronchoscopy and with delayed diagnosis (p<0.01). The FBs were most frequently of vegetable origin, such as seeds and peanuts. A significant tissue reaction with inflammation was more common in the delayed cases. CONCLUSION: To prevent delayed diagnosis, characteristic symptoms, signs and radiological findings of FBA should be checked in all suspected cases. As clinical and radiological findings of FBA in delayed cases may mimic other disorders, the clinician must be aware of the likelihood of FBA. Regardless of radiological findings, bronchoscopy should be considered in patients with an appropriate history.

  14. Reciprocal Relations between Student-Teacher Relationship and Children's Behavioral Problems: Moderation by Child-Care Group Size

    Science.gov (United States)

    Skalická, Vera; Belsky, Jay; Stenseng, Frode; Wichstrøm, Lars

    2015-01-01

    In this Norwegian study, bidirectional relations between children's behavior problems and child-teacher conflict and closeness were examined, and the possibility of moderation of these associations by child-care group size was tested. Eight hundred and nineteen 4-year-old children were followed up in first grade. Results revealed reciprocal…

  15. Delayed repair of the peripheral nerve: a novel model in the rat sciatic nerve.

    Science.gov (United States)

    Wu, Peng; Spinner, Robert J; Gu, Yudong; Yaszemski, Michael J; Windebank, Anthony J; Wang, Huan

    2013-03-30

    Peripheral nerve reconstruction is seldom done in the acute phase of nerve injury due to concomitant injuries and the uncertainty of the extent of nerve damage. A proper model that mimics true clinical scenarios is critical but lacking. The aim of this study is to develop a standardized, delayed sciatic nerve repair model in rats and validate the feasibility of direct secondary neurrorraphy after various delay intervals. Immediately or 1, 4, 6, 8 and 12 weeks after sciatic nerve transection, nerve repair was carried out. A successful tension-free direct neurorraphy (TFDN) was defined when the gap was shorter than 4.0 mm and the stumps could be reapproximated with 10-0 stitches without detachment. Compound muscle action potential (CMAP) was recorded postoperatively. Gaps between the two nerve stumps ranged from 0 to 9 mm, the average being 1.36, 2.85, 3.43, 3.83 and 6.4 mm in rats with 1, 4, 6, 8 and 12 week delay, respectively. The rate of successful TFDN was 78% overall. CMAP values of 1 and 4 week delay groups were not different from the immediate repair group, whereas CMAP amplitudes of 6, 8 and 12 week delay groups were significantly lower. A novel, standardized delayed nerve repair model is established. For this model to be sensitive, the interval between nerve injury and secondary repair should be at least over 4 weeks. Thereafter the longer the delay, the more challenging the model is for nerve regeneration. The choice of delay intervals can be tailored to meet specific requirements in future studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Delayed power analysis

    International Nuclear Information System (INIS)

    Adamovich, L.A.; Azarov, V.V.

    1999-01-01

    Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

  17. Global Hopf bifurcation analysis on a BAM neural network with delays

    Science.gov (United States)

    Sun, Chengjun; Han, Maoan; Pang, Xiaoming

    2007-01-01

    A delayed differential equation that models a bidirectional associative memory (BAM) neural network with four neurons is considered. By using a global Hopf bifurcation theorem for FDE and a Bendixon's criterion for high-dimensional ODE, a group of sufficient conditions for the system to have multiple periodic solutions are obtained when the sum of delays is sufficiently large.

  18. Global Hopf bifurcation analysis on a BAM neural network with delays

    International Nuclear Information System (INIS)

    Sun Chengjun; Han Maoan; Pang Xiaoming

    2007-01-01

    A delayed differential equation that models a bidirectional associative memory (BAM) neural network with four neurons is considered. By using a global Hopf bifurcation theorem for FDE and a Bendixon's criterion for high-dimensional ODE, a group of sufficient conditions for the system to have multiple periodic solutions are obtained when the sum of delays is sufficiently large

  19. Impulsive stabilization and impulsive synchronization of discrete-time delayed neural networks.

    Science.gov (United States)

    Chen, Wu-Hua; Lu, Xiaomei; Zheng, Wei Xing

    2015-04-01

    This paper investigates the problems of impulsive stabilization and impulsive synchronization of discrete-time delayed neural networks (DDNNs). Two types of DDNNs with stabilizing impulses are studied. By introducing the time-varying Lyapunov functional to capture the dynamical characteristics of discrete-time impulsive delayed neural networks (DIDNNs) and by using a convex combination technique, new exponential stability criteria are derived in terms of linear matrix inequalities. The stability criteria for DIDNNs are independent of the size of time delay but rely on the lengths of impulsive intervals. With the newly obtained stability results, sufficient conditions on the existence of linear-state feedback impulsive controllers are derived. Moreover, a novel impulsive synchronization scheme for two identical DDNNs is proposed. The novel impulsive synchronization scheme allows synchronizing two identical DDNNs with unknown delays. Simulation results are given to validate the effectiveness of the proposed criteria of impulsive stabilization and impulsive synchronization of DDNNs. Finally, an application of the obtained impulsive synchronization result for two identical chaotic DDNNs to a secure communication scheme is presented.

  20. Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

    Science.gov (United States)

    Sarmiento, J Manuel; Venteicher, Andrew S; Patil, Chirag G

    2015-01-01

    progression compared to observation (and delayed radiotherapy upon disease progression) for people with LGG but does not significantly improve overall survival (OS). The median progression-free survival (PFS) was 5.3 years in the early radiotherapy group and 3.4 years in the delayed radiotherapy group (hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.45 to 0.77; P value radiotherapy group was 7.4 years, while the delayed radiotherapy group experienced a median overall survival of 7.2 years (HR 0.97, 95% CI 0.71 to 1.33; P value = 0.872; 311 participants; 1 trail; low quality evidence). The total dose of radiotherapy given was 54 Gy; five fractions of 1.8 Gy per week were given for six weeks. Adverse effects following radiotherapy consisted of skin reactions, otitis media, mild headache, nausea, and vomiting. Rescue therapy was provided to 65% of the participants randomised to delayed radiotherapy. People in both cohorts who were free from tumour progression showed no differences in cognitive deficit, focal deficit, performance status, and headache after one year. However, participants randomised to the early radiotherapy group experienced significantly fewer seizures than participants in the delayed postoperative radiotherapy group at one year (25% versus 41%, P value = 0.0329, respectively). Authors’ conclusions Given the high risk of bias in the included study, the results of this analysis must be interpreted with caution. Early radiation therapy was associated with the following adverse effects: skin reactions, otitis media, mild headache, nausea, and vomiting. People with LGG who undergo early radiotherapy showed an increase in time to progression compared with people who were observed and had radiotherapy at the time of progression. There was no significant difference in overall survival between people who had early versus delayed radiotherapy; however, this finding may be due to the effectiveness of rescue therapy with radiation in the control arm. People who

  1. Attosecond time delay in the valence photoionization of C240 versus C60

    International Nuclear Information System (INIS)

    Shi, Kele; Magrakvelidze, Maia; Anstine, Dylan; Chakraborty, Himadri; Madjet, Mohamed

    2015-01-01

    We investigate effects of electron correlations on the attosecond time delay of the photoionization from HOMO and HOMO-1 electrons in C 240 . A comparison with earlier C 60 results assesses the molecular size effect. (paper)

  2. Risk factors for delayed healing at the free anterolateral thigh flap donor site

    Directory of Open Access Journals (Sweden)

    Yoshiro Abe

    2018-01-01

    Full Text Available Background The free anterolateral thigh (ALT flap has been widely used for various kinds of reconstructions. However, delayed healing at the donor site occasionally occurs due to wound dehiscence or the partial loss of grafted skin at the donor site. The aim of the present study was to identify reliable predictive factors for delayed healing at the donor site after the harvest of a free ALT flap. Methods This study included 52 patients who underwent reconstructive procedures using free ALT flaps. The delayed healing group included patients with wounds at the donor site that had not healed over 3 weeks after surgery, and the normal healing group included patients who showed wound healing within 3 weeks after surgery. Multivariate logistic regression models were created to identify the risk factors for delayed healing at the ALT flap donor site. Results Among the 52 patients, 24 (46.2% showed delayed healing at the donor site, and 6 patients required additional operative treatment. A high preoperative body mass index (BMI, smoking, and skin grafting were found to be significantly associated with delayed healing at the ALT donor site. Of the 37 patients who underwent skin grafting, 23 (62% experienced delayed healing at the donor site. Conclusions A high preoperative BMI, smoking, and skin grafting were risk factors for delayed healing at the free ALT donor site. Skin grafting at the ALT donor site should be avoided in patients with a high BMI or a habit of smoking.

  3. Normal ventricular size and changes with age in pediatric groups on computed tomography

    International Nuclear Information System (INIS)

    Nakada, Yoshitaka; Nose, Tadao; Enomoto, Takao; Maki, Yutaka

    1980-01-01

    The purpose of this report is to determine the normal value of the ventricular size on CT, snd analyze its changes with age in normal pediatric group. Materials and Methods: We searched through our 240 normal pediatric CT film files, aged 4 months to 14 years. Scans were performed on Hitachi CT-II scanner, using 10 mm collimation. Results: 1. The width of the third ventricle showed the same value in all pediatric groups, the mean value of its being 4.8 mm (SD 1.3 mm). 2. Bicaudate cerebroventricular indexes of the anterior horns of lateral ventricles (interecarlate distance/transverse diameter of the brain x100) were 15.3 in infants under one year, 13.8 in the age of one year and 12.7 in the children over two years. The indexes were almost the same in old age group over the age of three years. 3. The upper limit of the normal inverse cella media index (minium width of cella media/transverse diameter of the brain x100) was 31. Therefore the cases with the index above this range can be diagnosed as hydrocephalic. 4. The shape of the anterior horns of lateral ventricles was Y-shaped in infants under one year. II-shaped (paralied shaped) in the age of 1 - 12 years, and again it was Y-shaped in the group over 12 years. 5. In the age group under one year, the temporal horns of the lateral ventricles were visualized in about 60% cases, while the figure decreased to 20% in the older group. (author)

  4. Hearing assessment in pre-school children with speech delay.

    Science.gov (United States)

    Psillas, George; Psifidis, Anestis; Antoniadou-Hitoglou, Magda; Kouloulas, Athanasios

    2006-09-01

    The purpose of this study was to detect any underlying hearing loss among the healthy pre-school children with speech delay. 76 children, aged from 1 to 5 years, underwent a thorough audiological examination consisting of tympanometry, free field testing, otoacoustic emission recordings and auditory brainstem responses (ABRs). If hearing was normal, then they were evaluated by a child neurologist-psychiatrist. According to our findings, the children were classified into 3 groups; those with normal hearing levels (group I, 52 children, 68.4%), sensorineural hearing loss (group II, 22 children, 28.9%) and conductive hearing loss (group III, 2 children, 2.6%). In group I, speech delay was attributed to pervasive developmental disorder (PDD), which represents high-functioning autistic children (37 cases). Other causes were specific language impairment (SLI)-expressive (3 cases), bilingualism (2 cases), and unknown etiology (10 cases). More than half (59%) of the children diagnosed with PDD evidenced significant language impairment limited to more than two words. Children with SLI-expressive and bilingualism used a maximum of two words. In group II, 13 children suffered from profound hearing loss in both ears, 3 from severe, 3 had profound hearing loss in one ear and severe in the other, 2 from moderate, and 1 had moderate in one ear and severe in the other. No child had mild sensorineural hearing loss. The children with profound hearing loss in at least one ear had total language impairment using no word at all (10 cases), or a maximum of two words (6 cases). When hearing loss was moderate to severe, then the speech vocabulary was confined to several words (more than two words-6 cases). Only two children suffering from conductive hearing loss both presented with complete lack of speech. A great number of healthy pre-school children with speech delay were found to have normal hearing. In this case, the otolaryngologist should be aware of the possible underlying clinical

  5. Speech and Language Delay

    Science.gov (United States)

    ... OTC Relief for Diarrhea Home Diseases and Conditions Speech and Language Delay Condition Speech and Language Delay Share Print Table of Contents1. ... Treatment6. Everyday Life7. Questions8. Resources What is a speech and language delay? A speech and language delay ...

  6. Delay in the Diagnosis of Stable Slipped Capital Femoral Epiphysis.

    Science.gov (United States)

    Hosseinzadeh, Pooya; Iwinski, Henry J; Salava, Jonathon; Oeffinger, Donna

    2017-01-01

    Delays in the diagnosis of stable slipped capital femoral epiphysis (SCFE) is common due to the vague symptomatology and the lack of awareness of this entity by healthcare providers. Delays in the diagnosis of this condition can lead to poor outcomes for the patients. This study was designed to identify factors that contributed to delays in the diagnosis or the treatment of patients with SCFE seen at our institution. A retrospective chart review of patients with the diagnosis of a stable SCFE who had undergone screw stabilization between 1989 and 2010 at our hospital was performed. For each patient, demographic data, the date of initial onset of symptoms, the date of the first visit to the medical provider, the type of provider seen initially (orthopaedic surgeon or not), the date of diagnosis of SCFE, the type of physician who made the diagnosis (orthopaedic surgeon or not), and the date of surgery were recorded. For each patient, the presenting symptom was recorded as hip, thigh, or knee pain. The effect of demographic data, presenting symptoms, and the type of initial provider seen on the delay to diagnosis was studied using 2 Cox models. A total of 149 patients with 196 stable SCFE were included. The average time from the first physician visit to diagnosis was 94 days in the group seen by a nonorthopaedic provider compared with an average of 2.9 days in the group seen by an orthopaedist (Pprovider versus 97% in the group seen by orthopaedic surgeons. It took significantly longer to be diagnosed with SCFE in patients who presented with initial knee pain (P=0.0097) compared with those who presented with hip pain at the initial visit. This study shows a significant delay in the diagnosis of SCFE in the United States, particularly in patients seen by nonorthopaedic providers initially. Level III-prognostic.

  7. Proceedings of the specialists' meeting on delayed neutron nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi [ed.] [Japanese Nuclear Data Committee, Tokai, Ibaraki (Japan)

    1999-07-01

    This report is the Proceedings of the Specialists' Meeting on Delayed Neutron Nuclear Data. The meeting was held on January 28-29, 1999, at the Tokai Research Establishment of Japan Atomic Energy Research Institute with the participation of thirty specialists, who are evaluators, theorist, experimentalists. Although the fraction of the delayed neutron is no more than 1% in the total neutrons emitted in the fission process, it plays an important roll in the control of fission reactor. In the meeting, the following topics were reported: the present status of delayed neutron data in the major evaluated data libraries, measurements of effective delayed neutron fraction using FCA (Fast Critical Assembly) and TCA (Tank-type Critical Assembly) and their analyses, sensitivity analysis for fast reactor, measurements of delayed neutron emission from actinides and so on. As another topics, delayed neutron in transmutation system and fission yield data were also presented. Free discussion was held on the future activity of delayed neutron data evaluation. The discussion was helpful for the future activity of the delayed neutron working group of JNDC aiming to the evaluation of delayed neutron data for JENDL-3.3. The 15 of the presented papers are indexed individually. (J.P.N.)

  8. Impact of delay to treatment upon survival in 1067 patients with breast-cancer.

    Science.gov (United States)

    Rabinovich, M; Vallejo, C; Perez, J; Rodriguez, R; Cuevas, M; Machiavelli, M; Lacava, J; Leone, B; Romero, A; Mickiewicz, E; Chacon, R; Estevez, R

    1993-02-01

    The medical records of 1067 patients with breast cancer were reviewed to evaluate the influence of delay between first symptom and first treatment upon survival. Three delay intervals were considered: 6 months. At a follow-up of 120 months, survival analyses identified a statistically significant difference (p=0.029) favoring patients with 3 months delay between first symptom and first treatment. Better survival rate for patients with a short delay would obey to a greater number of patients in favorable stages and a higher proportion of women aged 50 or older in this group.

  9. Population is the main driver of war group size and conflict casualties.

    Science.gov (United States)

    Oka, Rahul C; Kissel, Marc; Golitko, Mark; Sheridan, Susan Guise; Kim, Nam C; Fuentes, Agustín

    2017-12-26

    The proportions of individuals involved in intergroup coalitional conflict, measured by war group size (W), conflict casualties (C), and overall group conflict deaths (G), have declined with respect to growing populations, implying that states are less violent than small-scale societies. We argue that these trends are better explained by scaling laws shared by both past and contemporary societies regardless of social organization, where group population (P) directly determines W and indirectly determines C and G. W is shown to be a power law function of P with scaling exponent X [demographic conflict investment (DCI)]. C is shown to be a power law function of W with scaling exponent Y [conflict lethality (CL)]. G is shown to be a power law function of P with scaling exponent Z [group conflict mortality (GCM)]. Results show that, while W/P and G/P decrease as expected with increasing P, C/W increases with growing W. Small-scale societies show higher but more variance in DCI and CL than contemporary states. We find no significant differences in DCI or CL between small-scale societies and contemporary states undergoing drafts or conflict, after accounting for variance and scale. We calculate relative measures of DCI and CL applicable to all societies that can be tracked over time for one or multiple actors. In light of the recent global emergence of populist, nationalist, and sectarian violence, our comparison-focused approach to DCI and CL will enable better models and analysis of the landscapes of violence in the 21st century. Copyright © 2017 the Author(s). Published by PNAS.

  10. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups

    OpenAIRE

    Hasija, Narender; Bala, Madhu; Goyal, Virender

    2014-01-01

    ABSTRACT Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton’s ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. Aim: To determine any difference in tooth size discrepancy in a...

  11. Relationships between processing delay and microbial load of broiler neck skin samples.

    Science.gov (United States)

    Lucianez, A; Holmes, M A; Tucker, A W

    2010-01-01

    The measurable microbial load on poultry carcasses during processing is determined by a number of factors including farm or origin, processing hygiene, and external temperature. This study investigated associations between carcass microbial load and progressive delays to processing. A total of 30 carcasses were delayed immediately after defeathering and before evisceration in a commercial abattoir in groups of five, and were held at ambient temperature for 1, 2, 3, 4, 6, and 8 h. Delayed carcasses were reintroduced to the processing line, and quantitative assessment of total viable count, coliforms, Staphylococcus aureus, and Pseudomonas spp. was undertaken on neck skin flap samples collected after carcass chilling and then pooled for each group. Sampling was repeated on 5 separate days, and the data were combined. Significant increases in total viable count (P = 0.001) and coliforms (P = 0.004), but not for S. aureus or Pseudomonas loads, were observed across the 8-h period of delay. In line with previous studies, there was significant variation in microbiological data according to sampling day. In conclusion, there is a significant and measurable decline in microbiological status of uneviscerated but defeathered poultry carcasses after an 8-h delay, but the variability of sampling results, reflecting the wide range of factors that impact microbial load, means that it is not possible to determine maximum or minimum acceptable periods of processing delay based on this criterion alone.

  12. When the Battle is Lost and Won: Delayed Chest Closure After Bilateral Lung Transplantation.

    Science.gov (United States)

    Soresi, Simona; Sabashnikov, Anton; Weymann, Alexander; Zeriouh, Mohamed; Simon, André R; Popov, Aron-Frederik

    2015-10-12

    In this article we summarize benefits of delayed chest closure strategy in lung transplantation, addressing indications, different surgical techniques, and additional perioperative treatment. Delayed chest closure seems to be a valuable and safe strategy in managing patients with various conditions after lung transplantation, such as instable hemodynamics, need for high respiratory pressures, coagulopathy, and size mismatch. Therefore, this approach should be considered in lung transplant centers to give patients time to recover before the chest is closed.

  13. Risk factors of delayed ulcer healing after gastric endoscopic submucosal dissection.

    Science.gov (United States)

    Lim, Joo Hyun; Kim, Sang Gyun; Choi, Jeongmin; Im, Jong Pil; Kim, Joo Sung; Jung, Hyun Chae

    2015-12-01

    Although post-endoscopic submucosal dissection (ESD) iatrogenic ulcer is known to heal faster than peptic ulcer, some iatrogenic ulcers show delayed healing. The aim of this study was to clarify risk factors of delayed ulcer healing after gastric ESD. We retrospectively reviewed medical records of all patients who had ESD for gastric neoplasms (866 adenomas and 814 early gastric cancers) between January 2005 and February 2011. Of 1680 subjects, 95 had delayed ulcer healing in 3-month follow-up. Multivariate analysis showed that diabetes (OR 1.743; 95% CI 1.017-2.989, p = 0.043), coagulation abnormality (OR 3.195; 95% CI 1.535-6.650, p = 0.002), specimen size greater than 4 cm (OR 2.999; 95% CI 1.603-5.611, p = 0.001), and electrocoagulation (OR 7.149; 95% CI 1.738-29.411, p = 0.006) were revealed to be independent risk factors of delayed ulcer healing. Meanwhile, persistent Helicobacter pylori infection was not related to the delayed ulcer healing. Large iatrogenic ulcer by ESD with massive hemostasis, especially in patients with diabetes mellitus or coagulation abnormalities, tends to take more than 3 months to heal. For such cases, initial dosage increment of PPI or addition of other anti-ulcer agents after ESD may be beneficial.

  14. On the linearity of cross-correlation delay times

    Science.gov (United States)

    Mercerat, E. D.; Nolet, G.

    2012-12-01

    We investigate the question whether a P-wave delay time Δ T estimated by locating the maximum of the cross-correlation function between data d(t) and a predicted test function s(t): γ (t) = ∫ t1t_2 s(τ ) d(τ -t) \\ {d}τ, provides an estimate of the Delta T that is (quasi-)linear with the relative velocity perturbation deltaln V_P}. Such linearity is intuitive if the data d(t) is an undeformed but delayed replica of the test signal, i.e. if d(t)=s(t-Delta T). Then the maximum of gamma (t) is shifted exactly by the delay Delta T, and linearity holds even for Delta T very large. In this case, we say that the body waves are in the ray theoretical regime and their delays, because of Fermat's Principle, depend quasi-linearly on the relative velocity (or slowness) perturbations deltaln V_P in the model. However, even if we correct for dispersion induced by the instrument response and by attenuation, body waves may show frequency dependent delay times that are caused by diffraction effects around lateral heterogeneities. It is not a-priori clear that linearity holds for Delta T, as is assumed in finite-frequency theory, if the waveforms of d(t) and s(t) differ substantially because of such dispersion. To test the linearity, we generate synthetic seismograms between two boreholes, and between the boreholes and the surface, in a 3D box of 200 × 120 × 120 m. The heterogeneity is a checkerboard with cubic anomalies of size 12 × 12 × 12 m. We test two different anomaly amplitudes: ± 2% and ± 5%, and measure Delta T using a test seismogram s(t) computed for an homogeneous medium. We also predict the delays for the 5% model from those in the 2% model by multiplying with 5/2. These predictions are in error by 10-20% of the delay, which is usually acceptable for tomography when compared with actual data errors. A slight bias in the prediction indicates that the Wielandt effect - the fact that negative delays suffer less wavefront healing than positive delays - is a

  15. Speech and language development in cognitively delayed children with cochlear implants.

    Science.gov (United States)

    Holt, Rachael Frush; Kirk, Karen Iler

    2005-04-01

    The primary goals of this investigation were to examine the speech and language development of deaf children with cochlear implants and mild cognitive delay and to compare their gains with those of children with cochlear implants who do not have this additional impairment. We retrospectively examined the speech and language development of 69 children with pre-lingual deafness. The experimental group consisted of 19 children with cognitive delays and no other disabilities (mean age at implantation = 38 months). The control group consisted of 50 children who did not have cognitive delays or any other identified disability. The control group was stratified by primary communication mode: half used total communication (mean age at implantation = 32 months) and the other half used oral communication (mean age at implantation = 26 months). Children were tested on a variety of standard speech and language measures and one test of auditory skill development at 6-month intervals. The results from each test were collapsed from blocks of two consecutive 6-month intervals to calculate group mean scores before implantation and at 1-year intervals after implantation. The children with cognitive delays and those without such delays demonstrated significant improvement in their speech and language skills over time on every test administered. Children with cognitive delays had significantly lower scores than typically developing children on two of the three measures of receptive and expressive language and had significantly slower rates of auditory-only sentence recognition development. Finally, there were no significant group differences in auditory skill development based on parental reports or in auditory-only or multimodal word recognition. The results suggest that deaf children with mild cognitive impairments benefit from cochlear implantation. Specifically, improvements are evident in their ability to perceive speech and in their reception and use of language. However, it may

  16. Effect of delayed polymerization time and bracket manipulation on orthodontic bracket bonding

    Science.gov (United States)

    Ponikvar, Michael J.

    This study examined the effect of bracket manipulation in combination with delayed polymerization times on orthodontic bracket shear bond strength and degree of resin composite conversion. Orthodontics brackets were bonded to extracted third molars in a simulated oral environment after a set period of delayed polymerization time and bracket manipulation. After curing the bracket adhesive, each bracket underwent shear bond strength testing followed by micro-Raman spectroscopy analysis to measure the degree of conversion of the resin composite. Results demonstrated the shear bond strength and the degree of conversion of ceramic brackets did not vary over time. However, with stainless steel brackets there was a significant effect (p ≤ 0.05) of delay time on shear bond strength between the 0.5 min and 10 min bracket groups. In addition, stainless steel brackets showed significant differences related to degree of conversion over time between the 0.5 min and 5 min groups, in addition to the 0.5 min and 10 min groups. This investigation suggests that delaying bracket adhesive polymerization up to a period of 10 min then adjusting the orthodontic bracket may increase both shear bond strength and degree of conversion of stainless steel brackets while having no effect on ceramic brackets.

  17. Synchronization of delayed systems in the presence of delay time modulation

    International Nuclear Information System (INIS)

    Kye, Won-Ho; Choi, Muhan; Kim, Myung-Woon; Lee, Soo-Young; Rim, Sunghwan; Kim, Chil-Min; Park, Young-Jai

    2004-01-01

    We investigate synchronization in the presence of delay time modulation for application to communication. We have observed that the robust synchronization is established by a common delay signal and its threshold is presented using Lyapunov exponents analysis. The influence of the delay time modulation in chaotic oscillators is also discussed

  18. Trauma patients who present in a delayed fashion: a unique and challenging population.

    Science.gov (United States)

    Kao, Mary J; Nunez, Hector; Monaghan, Sean F; Heffernan, Daithi S; Adams, Charles A; Lueckel, Stephanie N; Stephen, Andrew H

    2017-02-01

    A proportion of trauma patients present for evaluation in a delayed fashion after injury, likely due to a variety of medical and nonmedical reasons. There has been little investigation into the characteristics and outcomes of trauma patients who present delayed. We hypothesize that trauma patients who present in a delayed fashion are a unique population at risk of increased trauma-related complications. This was a retrospective review from 2010-2015 at a Level I trauma center. Patients were termed delayed if they presented >24 hours after injury. Patients admitted within 24 hours of their injury were the comparison group. Charts were reviewed for demographics, mechanism, comorbidities, complications and outcomes. A subgroup analysis was done on patients who suffered falls. During the 5-y period, 11,705 patients were admitted. A total of 588 patients (5%) presented >24 h after their injury. Patients in the delayed group were older (65 versus 55 y, P fashion have unique characteristics and are more likely to suffer negative outcomes including substance withdrawal. Future goals will include exploring strategies for early intervention, such as automatic withdrawal monitoring and social work referral for all patients who present in a delayed fashion. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Fast realization of nonrecursive digital filters with limits on signal delay

    Science.gov (United States)

    Titov, M. A.; Bondarenko, N. N.

    1983-07-01

    Attention is given to the problem of achieving a fast realization of nonrecursive digital filters with the aim of reducing signal delay. It is shown that a realization wherein the impulse characteristic of the filter is divided into blocks satisfies the delay requirements and is almost as economical in terms of the number of multiplications as conventional fast convolution. In addition, the block method leads to a reduction in the needed size of the memory and in the number of additions; the short-convolution procedure is substantially simplified. Finally, the block method facilitates the paralleling of computations owing to the simple transfers between subfilters.

  20. Comparison of energy balance between two different-sized groups of Japanese macaques (Macaca fuscata yakui).

    Science.gov (United States)

    Kurihara, Yosuke; Hanya, Goro

    2017-07-01

    Quantifying the energy balance is essential for testing socio-ecological models. To reveal costs and benefits of group living in Japanese macaques from the perspective of feeding competition, Kurihara and Hanya (Am J Primatol 77:986-1000, 2015) previously compared feeding behavior between two different-sized groups of macaques (larger group 30-35 individuals; smaller group 13-15 individuals) in the coastal forest of Yakushima, Japan. The results suggested that the larger group exhibited greater feeding effort because of intragroup scramble competition and that the smaller group suffered from higher travel costs, possibly owing to intergroup contest competition. However, it remained unclear whether the behavioral differences affected their energy budgets. The present study examined energetic consequences of the different feeding behaviors in the two groups. Using behavioral data from 10 to 13 adult females and nutritional composition of food items, we compared ingestion rates, energetic/nutritional content of diet, and energy budgets between the two groups. Ingestion rates and energetic/nutritional content of diet did not differ between the two groups. Despite the higher feeding effort of the larger group, energy intake did not differ between the two groups. Energy expenditure did not differ between the two groups because higher travel costs were negated by lower feeding effort in the smaller group. Consequently, the energy balance did not differ between the two groups. We demonstrated that the behavioral measures of feeding competition were not translated into their energetic condition; moreover, our findings re-emphasize the importance of quantifying behavioral and fitness measures for interpreting variation in feeding behavior properly.

  1. Chaos synchronization in time-delayed systems with parameter mismatches and variable delay times

    International Nuclear Information System (INIS)

    Shahverdiev, E.M.; Nuriev, R.A.; Hashimov, R.H.; Shore, K.A.

    2004-06-01

    We investigate synchronization between two undirectionally linearly coupled chaotic nonidentical time-delayed systems and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only retarded synchronization with the coupling delay time is obtained. We show that with parameter mismatch or without it neither complete nor anticipating synchronization occurs. We derive existence and stability conditions for the retarded synchronization manifold. We demonstrate our approach using examples of the Ikeda and Mackey Glass models. Also for the first time we investigate chaos synchronization in time-delayed systems with variable delay time and find both existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. (author)

  2. Aspectos motores corporais e orais em um grupo de crianças com transtorno/atraso fonológico Body and oral motor aspects in a group of children with phonological delay/disorder

    Directory of Open Access Journals (Sweden)

    Ana Paula Ramos de Souza

    2010-01-01

    Full Text Available OBJETIVO: Comparar o desenvolvimento motor e aspectos orofaciais em crianças com transtorno e atraso fonológico. MÉTODOS: Participaram da pesquisa 80 crianças de cinco a 11 anos de idade pertencentes à rede escolar regular de um município da Grande Porto Alegre com alterações fonológicas. Foi realizada uma entrevista com os pais através de um questionário semi-estruturado. Em seguida, foram avaliados o sistema estomatognático e a fala das crianças, e o diagnóstico de transtorno ou atraso fonológico foi confirmado para cada sujeito. Para a análise estatística, foram utilizados os testes de Fisher e o Qui-quadrado com nível de significância de 5% (pPURPOSE: To compare the motor development and orofacial aspects in children with phonological disorder and delay. METHODS: The participants were 80 children with phonological deficits and ages ranging from five to 11 years, who belonged to the regular school system of a city in Rio Grande do Sul, Brazil. An interview with their parents was conducted, using a semi-structured questionnaire. After that, it was carried out the assessment of the subjects' stomatognathic system and speech, and the diagnosis of phonological delay or disorder was confirmed. The Chi-square test and the Fisher test were used for statistical analysis, with significance level of 5% (p<0,05. RESULTS: There were no statistically significant differences between the group with phonological delay and the group with phonological disorder in all aspects examined. CONCLUSION: Phonological delay and disorder do not show significant distinction regarding motor, oral and infectious aspects, together with deleterious oral habits, as shown by the homogeneity between the groups.

  3. Factors affecting the diagnostic delay in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Cellura, Eleonora; Spataro, Rossella; Taiello, Alfonsa Claudia; La Bella, Vincenzo

    2012-07-01

    Although amyotrophic lateral sclerosis (ALS) is a relentlessly progressive disorder, early diagnosis allows a prompt start with the specific drug riluzole and an accurate palliative care planning. ALS at onset may however mimic several disorders, some of them treatable (e.g., multifocal motor neuropathy) or epidemiologically more frequent (e.g., cervical myelopathy). To study the delay from onset to diagnosis in a cohort of ALS patients and to the variables that may affect it. We performed a retrospective analysis of the diagnostic delays in a cohort of 260 patients affected by ALS (M/F = 1.32) followed at our tertiary referral ALS Center between 2000 and 2007. The median time from onset to diagnosis was 11 months (range: 6-21) for the whole ALS cohort, 10 months (range: 6-15) in bulbar-onset (n = 65) and 12 months (range: 7-23) in spinal-onset (n = 195) patients (p = 0.3). 31.1% of patients received other diagnoses before ALS and this led to a significant delay of the correct diagnosis in this group (other diagnoses before ALS, n = 81: median delay, 15 months [9.75-24.25] vs ALS, n = 179, median delay, 9 months [6-15.25], p heuristics might represent an important contributing factor. Furthermore, the length of the differential diagnosis from other disorders and delays in referral to the neurologist seems to be positively associated with the delay in diagnosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Factors Associated with Delayed Cancer Diagnosis in Egyptian Children

    Directory of Open Access Journals (Sweden)

    E.R. Abdelkhalek

    2014-01-01

    Full Text Available Background Despite tremendous importance of early cancer diagnosis in children, few studies on this topic have been conducted in Egypt. Early stage diagnosis can have a positive effect on prognoses and the quality of life of children with cancer. We investigated delays in the diagnosis of childhood cancers in Egypt and determined the factors associated with these delays. Methods This retrospective study included 172 children with cancer from two pediatric oncology units. The interval between symptoms onset and final diagnosis for each child was estimated and examined by univariate and multivariate analyses to determine correlations with the child's sex, age at diagnosis, type and site of malignancy, family residence, socioeconomic status, and parental educational level. Findings The median total diagnosis delay period was 47 days caused by patients and/or parents (8 days and diagnosis (28 days. Statistically significant patient factors associated with delayed diagnosis were age (<5 years, lower parental education, and socioeconomic status. Sex residence and family size were not significant. Malignancy type and tumor site significantly affected the time for diagnosis. The lowest median value was associated with germ cell tumors (GCTs and leukemia, and the highest value was in children with brain tumor. Missed diagnoses were initially recorded in 39.5% of the patients and were associated with patient and tumor factors. Interpretation Delayed diagnosis of childhood cancer is related to age, family, socioeconomic status and parental education, and cancer type and site. Efforts should be made to promote awareness, develop effective steps to eliminate possible contributing factors, and determine the best intervention method.

  5. Radiation induced early delayed changes in mice brain: a 1h MRS and behavioral evaluation study

    International Nuclear Information System (INIS)

    Gupta, Mamta; Rana, Poonam; Haridas, Seenu; Manda, Kailash; Hemanth Kumar, B.S.; Khushu, Subash

    2014-01-01

    Radiation induced CNS injury can be classified as acute, early delayed and late delayed. Most of the studies suggest that acute injury is reversible whereas early delayed and late delayed injury is irreversible leading to metabolic and cognitive impairment. Extensive research has been carried out on cranial radiation induced early and late delayed changes, there are no reports on whole body radiation induced early and delayed changes. The present study was designed to observe early delayed effects of radiation during whole body radiation exposure. A total of 20 C57 male mice were divided in two groups of 10 animals each. One group was exposed to a dose of 5 Gy whole body radiation through Tele 60 Co irradiation facility with source operating at 2.496 Gy/min, while other group served as sham irradiated control. Behavioral and MR spectroscopy was carried out 3 months post irradiation. Behavioral parameters such as locomotor activity and working memory were evaluated first then followed by MR spectroscopy at 7T animal MRI system. For MRS, voxel was localised in the cortex-hippocampus region of mouse brain. MR spectra were acquired using PRESS sequence, FID was processed using LC model for quantitation. The data showed impaired cognitive functions and altered metabolite levels during early delayed phase of whole body radiation induced injury. In behavioural experiments, there was a significant impairment in the cognitive as well as exploratory functions at 3 months post irradiation in irradiated group as compared to controls. MRS results explained changes in mI, glutamine and glx levels in irradiated animals compared to controls. Altered mI level has been found to be associated with reduced cognitive abilities in many brain disorders including MCI and Alzheimer's disease. The findings of this study suggest that whole body radiation exposure may have long lasting effect on the cognitive performance. (author)

  6. A low dead time vernier delay line TDC implemented in an Actel flash-based FPGA

    International Nuclear Information System (INIS)

    Qin Xi; Feng Changqing; Zhang Deliang; Zhao Lei; Liu Shubin; An Qi

    2013-01-01

    In this paper, a high precision vernier delay line (VDL) TDC (Time-to-Digital Converter) in an Actel flash-based Field-Programmable-Gate-Arrays A3PE1500 is implemented, achieving a resolution of 16.4-ps root mean square value or 42-ps averaged bin size. The TDC has a dead time of about 200 ns while the dynamic range is 655.36 Vs. The double delay lines method is employed to cut the dead time in half to improve its performance. As the bin size of the TDC is dependent on temperature, a compensation algorithm is adopted as temperature drift correction, and the TDC shows satisfying performance in a temperature range from -5℃ to +55℃. (authors)

  7. REPERCUSSIONS OF THE INCREASE IN GROUP SIZE IN EARLY CHILDHOOD EDUCATION: THE PERSPECTIVE OF EDUCATORS

    Directory of Open Access Journals (Sweden)

    Casla, Marta

    2014-10-01

    Full Text Available This work describes some of the consequences of new regulations on nurseries in the Madrid area that are related to ratios and group size (especially after the decree 18/2008. Analyses are based on educators and education staff’s point of view. Special emphasis is made on consequences on children behavior. Two hundred and seventy seven professionals that belonged to more than 53 nurseries of Madrid area voluntarily answered a survey with open questions about educative process and child’s behavior. Qualitative and quantitative analyses show that, from educator’s point of view, increasing ratio child-educator has consequences in the variables explored. Main effects were found for the activities made in classrooms (loosing educative standards, hygiene and supply routines (loosing intrinsic values and autonomy support, space and time distribution, support staff organization and relation with families (reduced to quick information interchanges. Directors, classroom tutors and support educators perceive these changes in a similar fashion. The vast majority perceived changes on children’s behavior- increases in the number of conflicts and anxiety. These results agree with previous research on the influence of child-educators ratios and group size on quality of education. Implications for child development are discussed. This paper is published in Spanish.

  8. Immediate versus delayed loading of strategic mini dental implants for the stabilization of partial removable dental prostheses: a patient cluster randomized, parallel-group 3-year trial.

    Science.gov (United States)

    Mundt, Torsten; Al Jaghsi, Ahmad; Schwahn, Bernd; Hilgert, Janina; Lucas, Christian; Biffar, Reiner; Schwahn, Christian; Heinemann, Friedhelm

    2016-07-30

    Acceptable short-term survival rates (>90 %) of mini-implants (diameter implants as strategic abutments for a better retention of partial removable dental prosthesis (PRDP) are not available. The purpose of this study is to test the hypothesis that immediately loaded mini-implants show more bone loss and less success than strategic mini-implants with delayed loading. In this four-center (one university hospital, three dental practices in Germany), parallel-group, controlled clinical trial, which is cluster randomized on patient level, a total of 80 partially edentulous patients with unfavourable number and distribution of remaining abutment teeth in at least one jaw will receive supplementary min-implants to stabilize their PRDP. The mini-implant are either immediately loaded after implant placement (test group) or delayed after four months (control group). Follow-up of the patients will be performed for 36 months. The primary outcome is the radiographic bone level changes at implants. The secondary outcome is the implant success as a composite variable. Tertiary outcomes include clinical, subjective (quality of life, satisfaction, chewing ability) and dental or technical complications. Strategic implants under an existing PRDP are only documented for standard-diameter implants. Mini-implants could be a minimal invasive and low cost solution for this treatment modality. The trial is registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00007589 ( www.germanctr.de ) on January 13(th), 2015.

  9. Effects of Stocking Density or Group Size on Intake, Growth, and Meat Quality of Hanwoo Steers (

    Directory of Open Access Journals (Sweden)

    Sang Moo Lee

    2012-11-01

    Full Text Available This study was conducted to investigate the effects of stocking density or group size on feed intake, daily gain, and carcass characteristics of Hanwoo (Korean indigenous breed steers reared from 7 months to 31 months of age. Thirty Hanwoo steers were divided into four groups with three replicates each (a total of 12 pens. In each group, one (G1, two (G2, three (G3, and four steers (G4 per pen were allocated as treatments. Pen size was 32.0 m2, and therefore Hanwoo steers in G1, G2, G3, and G4 were reared under different space allowances, i.e. 32.0, 16.0, 10.6, and 8.0 m2/steer, respectively. Steers were reared following a conventional beef cattle management method in Korea, and were offered a fixed amount of commercial concentrate with ad libitum forages. Results were subjected to analysis of variance with stocking density as the main effect, and significance was declared at p<0.05. Although total feed intake was not significantly altered, it numerically increased in animals of low stocking density (G1 compared to those subjected to high stocking density treatment (i.e. G4. Feed conversion ratio was higher (p<0.05 in G3 compared to G1 and G2. Animals in G1 (low stocking density grew faster (p<0.05 than those of high stocking density (G3 and G4. Back fat thickness, meat yield index, and meat yield grade were similar among all levels of stocking density. However, longissimus muscle area was larger in G1 and G2 (p<0.01 compared to G3 and G4, and animals in G3 produced smaller carcasses (p<0.05. Carcass quality traits, including marbling score, meat color, fat color, texture, maturity and meat quality grade, as determined by a group of experts, were not significantly different among the treatments. In conclusion, lower stocking density resulted in increased feed efficiency, daily gain, and carcass weight in Hanwoo steers. However it remains unclear whether such differences are the results of stocking density or group size, or a combination of both

  10. Malignant cliomas treated after surgery by combination chemotherapy and delayed irradiation. Pt. 1

    International Nuclear Information System (INIS)

    Poisson, M.; Mashaly, R.; Pertuiset, B.F.; Metzger, J.

    1979-01-01

    Forty-six patients with gliomas were introduced after surgery into a therapeutic programme of six cycles of combination chemotherapy with VM 26 and CCNU, followed by delayed irradiation six months after surgery with an average dose of 5,800 rads. After irradiation the same preradiation chemotherapy was readministered for an average of four cycles. The results were compared to those from another group of 28 patients treated only by the same chemotherapy (CRC and C groups successively). Twelve patients (26%) died before irradiation in the CRC groups, six patients (13%) had recurrences at the time of irradiation, and 28 patients (61%) had no clinical or radiological signs of recurrence at the time of irradiation. For the total of treated patients the median survival after surgery was 17 months, and 46% of the patients were surviving at 18 months. The percentage of survivors at 18 months was significantly more elevated in the group treated by combination chemotherapy and delayed irradiation than in a control group treated by the same combination chemotherapy alone. This result suggests that in approximately 50% of cases combination chemotherapy after surgery, and delayed irradiation six months after surgery, cumulated their effects on survival time. (author)

  11. Airline's choice of aircraft size-explanations and implications

    NARCIS (Netherlands)

    Rietveld, P.; Givoni, M.

    2009-01-01

    When facing a growth in demand, airlines tend to respond more by means of increasing frequencies than by increasing aircraft size. At many of the world's largest airports there are fewer than 100 passengers per air transport movement, although congestion and delays are growing. Furthermore, demand

  12. Impact of system delay on infarct size, myocardial salvage index, and left ventricular function in patients with ST-segment elevation myocardial infarction

    DEFF Research Database (Denmark)

    Lønborg, Jacob Thomsen; Schoos, Mikkel Malby; Kelbæk, Henning Skov

    2012-01-01

    The association between reperfusion delay and myocardial damage has previously been assessed by evaluation of the duration from symptom onset to invasive treatment, but results have been conflicting. System delay defined as the duration from first medical contact to first balloon dilatation is less...

  13. Effects of group size on behaviour, growth and occurrence of bite marks in farmed mink

    DEFF Research Database (Denmark)

    Axelsson, Helene M. K.; Hansen, Steffen W.; Loberg, Jenny

    2017-01-01

    The aims of this study were to investigate the occurrence of stereotypic behaviours and the activity level in farmed mink when group housed in climbing cages and if group housing increase aggression by assessing the prevalence of bite marks. This was studied in juvenile mink of the colour types...... sunset during six periods of five days each from August-October. After pelting, the leather side of the undried skins were visually inspected for bite marks. Stereotypic behaviours were infrequent (0.1% of observations). Pair housed mink in climbing cages were more "inactive out in cage" than pair housed...... mink in standard cages (p 0.0001), but cage type had no effect on the behaviours "being in nest box", "active out in cage", "interactions with enrichments" or "social interactions" (n.s.). Group sizes of three or four mink increased the behaviours "active out in cage" (P 0.0001) and decreased "being...

  14. Extracorporeal shockwave enhanced regeneration of fibrocartilage in a delayed tendon-bone insertion repair model.

    Science.gov (United States)

    Chow, Dick Ho Kiu; Suen, Pui Kit; Huang, Le; Cheung, Wing-Hoi; Leung, Kwok-Sui; Ng, Chun; Shi, San Qiang; Wong, Margaret Wan Nar; Qin, Ling

    2014-04-01

    Fibrous tissue is often formed in delayed healing of tendon bone insertion (TBI) instead of fibrocartilage. Extracorporeal shockwave (ESW) provides mechanical cues and upregulates expression of fibrocartilage-related makers and cytokines. We hypothesized that ESW would accelerate fibrocartilage regeneration at the healing interface in a delayed TBI healing model. Partial patellectomy with shielding at the TBI interface was performed on 32 female New Zealand White Rabbits for establishing this delayed TBI healing model. The rabbits were separated into the control and ESW group for evaluations at postoperative week 8 and 12. Shielding was removed at week 4 and a single ESW treatment was applied at week 6. Fibrocartilage regeneration was evaluated histomorphologically and immunohistochemically. Vickers hardness of the TBI matrix was measured by micro-indentation. ESW group showed higher fibrocartilage area, thickness, and proteoglycan deposition than the control in week 8 and 12. ESW increased expression of SOX9 and collagen II significantly in week 8 and 12, respectively. ESW group showed a gradual transition of hardness from bone to fibrocartilage to tendon, and had a higher Vickers hardness than the control group at week 12. In conclusion, ESW enhanced fibrocartilage regeneration at the healing interface in a delayed TBI healing model. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Delayed healing of lower limb fractures with bisphosphonate therapy.

    Science.gov (United States)

    Yue, B; Ng, A; Tang, H; Joseph, S; Richardson, M

    2015-07-01

    Bisphosphonate therapy (BT) is used commonly in the management of osteoporosis. A systematic review was conducted investigating delayed union of lower limb, long bone fractures in patients on BT. We specifically assessed whether BT increases the risk of delayed union or non-union in lower limb, long bone fractures. A literature search was conducted in the PubMed and Embase™ on 4 November 2014. Articles that investigated lower limb fractures, history of BT and fracture union were included in the review. A total of 9,809 papers were retrieved and 14 were deemed suitable for this review. The mean time to union in patients on BT was 8.5 months. A longer time to union was reported in a study investigating BT users versus controls (6.5 vs 4.8 months respectively). The mean rate of delayed or non-union for BT associated atypical fractures was 20% per fracture. Specifically in one study, delayed union was more common in the cohort with more than three years of BT (67%) than in the group with less than three years of BT (26%). Surgical fixation was associated with improved outcomes compared with non-operative management. BT has been described to be associated with multiple adverse outcomes related to atypical fractures. Current evidence recommends operative management for this patient group. Further investigation is required to evaluate the exact effects of BT on lower limb fractures, in particular typical femoral fractures.

  16. Comparison of visual scoring and quantitative planimetry methods for estimation of global infarct size on delayed enhanced cardiac MRI and validation with myocardial enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Mewton, Nathan, E-mail: nmewton@gmail.com [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France); Revel, Didier [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France); Bonnefoy, Eric [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); Ovize, Michel [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); INSERM Unite 886 (France); Croisille, Pierre [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France)

    2011-04-15

    Purpose: Although delayed enhanced CMR has become a reference method for infarct size quantification, there is no ideal method to quantify total infarct size in a routine clinical practice. In a prospective study we compared the performance and post-processing time of a global visual scoring method to standard quantitative planimetry and we compared both methods to the peak values of myocardial biomarkers. Materials and methods: This study had local ethics committee approval; all patients gave written informed consent. One hundred and three patients admitted with reperfused AMI to our intensive care unit had a complete CMR study with gadolinium-contrast injection 4 {+-} 2 days after admission. A global visual score was defined on a 17-segment model and compared with the quantitative planimetric evaluation of hyperenhancement. The peak values of serum Troponin I (TnI) and creatine kinase (CK) release were measured in each patient. Results: The mean percentage of total left ventricular myocardium with hyperenhancement determined by the quantitative planimetry method was (20.1 {+-} 14.6) with a range of 1-68%. There was an excellent correlation between quantitative planimetry and visual global scoring for the hyperenhancement extent's measurement (r = 0.94; y = 1.093x + 0.87; SEE = 1.2; P < 0.001) The Bland-Altman plot showed a good concordance between the two approaches (mean of the differences = 1.9% with a standard deviation of 4.7). Mean post-processing time for quantitative planimetry was significantly longer than visual scoring post-processing time (23.7 {+-} 5.7 min vs 5.0 {+-} 1.1 min respectively, P < 0.001). Correlation between peak CK and quantitative planimetry was r = 0.82 (P < 0.001) and r = 0.83 (P < 0.001) with visual global scoring. Correlation between peak Troponin I and quantitative planimetry was r = 0.86 (P < 0.001) and r = 0.85 (P < 0.001) with visual global scoring. Conclusion: A visual approach based on a 17-segment model allows a rapid

  17. Comparison of visual scoring and quantitative planimetry methods for estimation of global infarct size on delayed enhanced cardiac MRI and validation with myocardial enzymes

    International Nuclear Information System (INIS)

    Mewton, Nathan; Revel, Didier; Bonnefoy, Eric; Ovize, Michel; Croisille, Pierre

    2011-01-01

    Purpose: Although delayed enhanced CMR has become a reference method for infarct size quantification, there is no ideal method to quantify total infarct size in a routine clinical practice. In a prospective study we compared the performance and post-processing time of a global visual scoring method to standard quantitative planimetry and we compared both methods to the peak values of myocardial biomarkers. Materials and methods: This study had local ethics committee approval; all patients gave written informed consent. One hundred and three patients admitted with reperfused AMI to our intensive care unit had a complete CMR study with gadolinium-contrast injection 4 ± 2 days after admission. A global visual score was defined on a 17-segment model and compared with the quantitative planimetric evaluation of hyperenhancement. The peak values of serum Troponin I (TnI) and creatine kinase (CK) release were measured in each patient. Results: The mean percentage of total left ventricular myocardium with hyperenhancement determined by the quantitative planimetry method was (20.1 ± 14.6) with a range of 1-68%. There was an excellent correlation between quantitative planimetry and visual global scoring for the hyperenhancement extent's measurement (r = 0.94; y = 1.093x + 0.87; SEE = 1.2; P < 0.001) The Bland-Altman plot showed a good concordance between the two approaches (mean of the differences = 1.9% with a standard deviation of 4.7). Mean post-processing time for quantitative planimetry was significantly longer than visual scoring post-processing time (23.7 ± 5.7 min vs 5.0 ± 1.1 min respectively, P < 0.001). Correlation between peak CK and quantitative planimetry was r = 0.82 (P < 0.001) and r = 0.83 (P < 0.001) with visual global scoring. Correlation between peak Troponin I and quantitative planimetry was r = 0.86 (P < 0.001) and r = 0.85 (P < 0.001) with visual global scoring. Conclusion: A visual approach based on a 17-segment model allows a rapid and accurate

  18. The effects of density dependent resource limitation on size of wild reindeer.

    Science.gov (United States)

    Skogland, Terje

    1983-11-01

    A density-dependent decrement in size for wild reindeer from 12 different Norwegian herds at 16 different densities was shown using lower jawbone-length as the criterion of size. This criterion was tested and found to adequately predict body size of both bucks and does. Lactation in does did not affect jaw length but significantly affected dressed weights.A decrement in the size of does as a result of gross density was found. This size decrement was further analysed in relation to the habitat densities in winter (R 2 =0.85) and in summer (R 2 =0.75) separately, in order to estimate the relative effects of each factor. For herds with adequate food in winter (no signs of overgrazing of lichens) density in relation to summer habitat and mires yielded the highest predictive power in a multiple regression. For herds with adequate summer pastures, densities per winter habitat and lichen volumes showed likewise a highly significant correlation. The inclusion of the lichen volume data in the regression increased its predictive power. The major effect of resource limitation was to delay the time of calving because a maternal carry-over effect allowed the calf a shorter period of growth to be completed during its first summer. Neonate size at birth was highly correlated with maternal size regardless of the mean calving date although the latter was significantly delayed for small-sized does in food resource-limited herds. Likewise the postnatal growth rate of all calves were not significantly different during 50 days postpartum regardless of maternal conditions in winter feeding. The summer growth rates of bucks ≧1 year did not vary significantly between herds. The age of maturity of food resource-limited does was delayed by one year and growth ceased after the initiation of reproduction. This shows that under conditions of limited resources the does with delayed births of calves allocated less energy to body growth simply because they had less time to replenish body

  19. Global synchronization criteria with channel time-delay for chaotic time-delay system

    International Nuclear Information System (INIS)

    Sun Jitao

    2004-01-01

    Based on the Lyapunov stabilization theory, matrix measure, and linear matrix inequality (LMIs), this paper studies the chaos synchronization of time-delay system using the unidirectional linear error feedback coupling with time-delay. Some generic conditions of chaos synchronization with time-delay in the transmission channel is established. The chaotic Chua's circuit is used for illustration, where the coupling parameters are determined according to the criteria under which the global chaos synchronization of the time-delay coupled systems is achieved

  20. The Effect of Learner-generated Illustrations on the Immediate And Delayed Recall of English Idioms

    Directory of Open Access Journals (Sweden)

    Afrouz Aeineh

    2014-06-01

    Full Text Available The present study investigated the effect of learner generated illustrations on the immediate and delayed idiom recall of Iranian EFL (English as a foreign language learners. To accomplish this end, 40 female students participated in this study. A placement test (Quick Placement Test, Version 2 was administered to the participants to ascertain that they were all at intermediate level of proficiency. Since the design of the study was quasi experimental, they were randomly assigned to control (N: 20 and experimental (N: 20 groups. A pretest of idioms was given to the participants to ensure that they were homogeneous in terms of their knowledge of idioms. Both groups were provided with the clarification of idioms through definitions and examples. However the experimental group was required to draw their own mental image of the idioms on a paper. At the end of the treatment, students took an immediate posttest of idioms. After an interval of 2 weeks, a similar posttest was given to the students to examine the delayed recall ability of the learners. The obtained results through an independent samples t-test indicated that the experimental group slightly outperformed the control group on immediate posttest, but the difference was not statistically significant. However the results on the delayed posttest suggested that there was a significant difference between the two groups and the participants in the experimental group had stronger delayed recall ability.

  1. Brain Size, IQ, and Racial-Group Differences: Evidence from Musculoskeletal Traits.

    Science.gov (United States)

    Rushton, J. Philippe; Rushton, Elizabeth W.

    2003-01-01

    Correlated brain size differences with 37 musculoskeletal variables shown in evolutionary textbooks to change with brain size. Findings from a sample of more than 6,000 U.S. military personnel indicate that racial differences in brain size are securely established and are the most likely biological mediators of race differences in intelligence.…

  2. Delayed minocycline but not delayed mild hypothermia protects against embolic stroke

    Directory of Open Access Journals (Sweden)

    Noor Raza

    2002-04-01

    Full Text Available Abstract Background Inflammatory reactions occurring in the brain after ischemia may contribute to secondary damage. In the present study, effects of minocycline, an anti-inflammatory agent, alone or in combination with mild hypothermia on focal embolic cerebral ischemia have been examined. Methods Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA. Infarction volume was measured at 48 h after the injury. Mortality was also recorded. Results Delayed administration of minocycline alone or delayed minocycline plus delayed mild hypothermia reduced the infarction volume significantly. However, delayed mild hypothermia alone was not protective and delayed mild hypothermia in combination with minocycline did not show any additive effect. Conclusions These results suggest that minocycline is beneficial in focal ischemic brain injury, and the lack of the enhanced neuroprotection may be due to the brief exposure to hypothermia.

  3. Adaptation to delayed force perturbations in reaching movements.

    Directory of Open Access Journals (Sweden)

    Noa Levy

    Full Text Available Adaptation to deterministic force perturbations during reaching movements was extensively studied in the last few decades. Here, we use this methodology to explore the ability of the brain to adapt to a delayed velocity-dependent force field. Two groups of subjects preformed a standard reaching experiment under a velocity dependent force field. The force was either immediately proportional to the current velocity (Control or lagged it by 50 ms (Test. The results demonstrate clear adaptation to the delayed force perturbations. Deviations from a straight line during catch trials were shifted in time compared to post-adaptation to a non-delayed velocity dependent field (Control, indicating expectation to the delayed force field. Adaptation to force fields is considered to be a process in which the motor system predicts the forces to be expected based on the state that a limb will assume in response to motor commands. This study demonstrates for the first time that the temporal window of this prediction needs not to be fixed. This is relevant to the ability of the adaptive mechanisms to compensate for variability in the transmission of information across the sensory-motor system.

  4. Factors associated with delayed bleeding after resection of large nonpedunculated colorectal polyps.

    Science.gov (United States)

    Elliott, Timothy R; Tsiamoulos, Zacharias P; Thomas-Gibson, Siwan; Suzuki, Noriko; Bourikas, Leonidas A; Hart, Ailsa; Bassett, Paul; Saunders, Brian P

    2018-04-06

    Delayed bleeding is the most common significant complication after piecemeal endoscopic mucosal resection (p-EMR) of large nonpedunculated colorectal polyps (NPCPs). Risk factors for delayed bleeding are incompletely defined. We aimed to determine risk factors for delayed bleeding following p-EMR.  Data were analyzed from a prospective tertiary center audit of patients with NPCPs ≥ 20 mm who underwent p-EMR between 2010 and 2012. Patient, polyp, and procedure-related data were collected. Four post p-EMR defect factors were evaluated for interobserver agreement and included in analysis. Delayed bleeding severity was reported in accordance with guidelines. Predictors of bleeding were identified.  Delayed bleeding requiring hospitalization occurred after 22 of 330 procedures (6.7 %). A total of 11 patients required blood transfusion; of these, 4 underwent urgent colonoscopy, 1 underwent radiological embolization, and 1 required surgery. Interobserver agreement for identification of the four post p-EMR defect factors was moderate (kappa range 0.52 - 0.57). Factors associated with delayed bleeding were visible muscle fibers ( P  = 0.03) and the presence of a "cherry red spot" ( P  = 0.05) in the post p-EMR defect. Factors not associated with delayed bleeding were American Association of Anesthesiologists class, aspirin use, polyp size, site, and use of argon plasma coagulation.  Visible muscle fibers and the presence of a "cherry red spot" in the resection defect were associated with delayed bleeding after p-EMR. These findings suggest evaluation and photodocumentation of the post p-EMR defect is important and, when considered alongside other patient and procedural factors, may help to reduce the incidence and severity of delayed bleeding. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Delays at signalised intersections with exhaustive traffic control

    NARCIS (Netherlands)

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2010-01-01

    In this paper we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under Heavy Traffic (HT) conditions,

  6. Delays at signalized intersections with exhaustive traffic control

    NARCIS (Netherlands)

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2012-01-01

    In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

  7. Delays at signalised intersections with exhaustive traffic control

    NARCIS (Netherlands)

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2012-01-01

    In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

  8. Delayed puberty in girls

    Science.gov (United States)

    ... sexual development - girls; Pubertal delay - girls; Constitutional delayed puberty ... In most cases of delayed puberty, growth changes just begin later than usual, sometimes called a late bloomer. Once puberty begins, it progresses normally. This pattern runs ...

  9. A Direct Comparison of Self-Injurious and Stereotyped Motor Behavior Between Preschool-Aged Children With and Without Developmental Delays.

    Science.gov (United States)

    Hoch, John; Spofford, Lisa; Dimian, Adele; Tervo, Raymond; MacLean, William E; Symons, Frank J

    2016-06-01

    To compare the prevalence of self-injurious behavior (SIB) and stereotyped motor behavior (STY) of preschool-aged children with developmental delays (DD group) and their peers without developmental delays (TD group) using a standardized caregiver report scale. The Repetitive Behavior Scale-Revised was completed by caregivers of children with developmental delays and their peers without developmental delays. Frequency of occurrence and severity ratings for SIB and STY were compared between groups. SIB and STY were reported more often and at a greater level of severity in the DD group. Older chronological age was associated with more severe STY in the DD group but not the TD group. Gender was not related to STY or SIB for either group. Differences in STY and SIB were evident between preschoolers with and without DD. Findings are discussed from developmental and behavioral psychology perspectives regarding the expression of repetitive behavior in developmentally at-risk pediatric populations. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Ethanol induces impulsive-like responding in a delay-of-reward operant choice procedure: impulsivity predicts autoshaping.

    Science.gov (United States)

    Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

    1998-10-01

    Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion of retractable lever conditioned stimulus (CS) followed by the response-independent delivery of food (US)] were followed by testing for impulsive-like responding in a two-choice lever-press operant delay-of-reward procedure (immediate small food reward versus delayed large food reward). Delay-of-reward functions revealed two distinct subject populations. Subjects in the Sensitive group (n=7) were more impulsive-like, increasing immediate reward choices at longer delays for large reward, while those in the Insensitive group (n=8) responded predominantly on only one lever. During the prior autoshaping phase, the Sensitive group had performed more autoshaping CRs, and correlations revealed that impulsive subjects acquired the autoshaping CR in fewer trials. In the Sensitive group, acute injections of ethanol (0, 0.25, 0.50, 1.00, 1.50 g/kg) given immediately before delay-of-reward sessions yielded an inverted U-shaped dose-response curve with increased impulsivity induced by the 0.25, 0.50, and 1.00 g/kg doses of ethanol, while choice strategy of the Insensitive group was not influenced by ethanol dose. Ethanol induced impulsive-like responding only in rats that were flexible in their response strategy (Sensitive group), and this group also performed more autoshaping CRs. Data support the hypothesis that autoshaping and impulsivity are linked.

  11. Delayed Puberty (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Delayed Puberty KidsHealth / For Teens / Delayed Puberty What's in this ... wonder if there's anything wrong. What Is Delayed Puberty? Puberty is the time when your body grows ...

  12. Comparison between hearing screening-detected cases and sporadic cases of delayed-onset hearing loss in preschool-age children.

    Science.gov (United States)

    Lü, Jingrong; Huang, Zhiwu; Ma, Yan; Li, Yun; Mei, Ling; Yao, Guoyin; Wang, Yu; Shen, Xiaoming; Wu, Hao

    2014-04-01

    This study aimed to compare the diagnosis and ages of intervention for cases of delayed-onset hearing loss identified sporadically or via a preschool hearing screening program. Retrospective study with the comparative analysis of two groups of children. Cases identified from screening were selected from 34 321 preschool children who underwent screening for delayed-onset hearing loss between October 2009 and May 2011. Sporadic cases of delayed-onset hearing loss were selected from pediatric clinical records. Cases from the first group were excluded from the latter to avoid duplication. Two groups were given the same questionnaire to record risk indicators, diagnosis, and age at intervention. The average age of 26 children at the time of diagnosis in the screening group (52.81 ± 13.23 months) was significantly earlier than in the 33 cases identified in the sporadic group (62.03 ± 12.86 months; p children with bilateral moderate to severe hearing loss in the screening group (50.40 ± 10.76 months) was also earlier than in the sporadic group (62.73 ± 13.77 months; p hearing screening for preschool children with no significant symptoms of delayed-onset hearing loss.

  13. Comparison of Immediate With Delayed Stenting Using the Minimalist Immediate Mechanical Intervention Approach in Acute ST-Segment-Elevation Myocardial Infarction: The MIMI Study.

    Science.gov (United States)

    Belle, Loic; Motreff, Pascal; Mangin, Lionel; Rangé, Grégoire; Marcaggi, Xavier; Marie, Antoine; Ferrier, Nadine; Dubreuil, Olivier; Zemour, Gilles; Souteyrand, Géraud; Caussin, Christophe; Amabile, Nicolas; Isaaz, Karl; Dauphin, Raphael; Koning, René; Robin, Christophe; Faurie, Benjamin; Bonello, Laurent; Champin, Stanislas; Delhaye, Cédric; Cuilleret, François; Mewton, Nathan; Genty, Céline; Viallon, Magalie; Bosson, Jean Luc; Croisille, Pierre

    2016-03-01

    Delayed stent implantation after restoration of normal epicardial flow by a minimalist immediate mechanical intervention aims to decrease the rate of distal embolization and impaired myocardial reperfusion after percutaneous coronary intervention. We sought to confirm whether a delayed stenting (DS) approach (24-48 hours) improves myocardial reperfusion, versus immediate stenting, in patients with acute ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention. In the prospective, randomized, open-label minimalist immediate mechanical intervention (MIMI) trial, patients (n=140) with ST-segment-elevation myocardial infarction ≤12 hours were randomized to immediate stenting (n=73) or DS (n=67) after Thrombolysis In Myocardial Infarction 3 flow restoration by thrombus aspiration. Patients in the DS group underwent a second coronary arteriography for stent implantation a median of 36 hours (interquartile range 29-46) after randomization. The primary end point was microvascular obstruction (% left ventricular mass) on cardiac magnetic resonance imaging performed 5 days (interquartile range 4-6) after the first procedure. There was a nonsignificant trend toward lower microvascular obstruction in the immediate stenting group compared with DS group (1.88% versus 3.96%; P=0.051), which became significant after adjustment for the area at risk (P=0.049). Median infarct weight, left ventricular ejection fraction, and infarct size did not differ between groups. No difference in 6-month outcomes was apparent for the rate of major cardiovascular and cerebral events. The present findings do not support a strategy of DS versus immediate stenting in patients with ST-segment-elevation infarction undergoing primary percutaneous coronary intervention and even suggested a deleterious effect of DS on microvascular obstruction size. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01360242. © 2016 American Heart Association, Inc.

  14. Group size effects on survivorship and adult development in the gregarious larvae of Euselasia chrysippe (Lepidoptera, Riodinidae)

    Science.gov (United States)

    P. E. Allen

    2010-01-01

    Caterpillars living in aggregations may derive several benefits that outweigh the costs, including better survivorship and improved growth rates. I tested whether larval group size had an effect on these two vital rates in Euselasia chrysippe. These caterpillars feed gregariously during all instars and move in processionary form over the host plant...

  15. Place matters: A longitudinal analysis measuring the association between neighbourhood walkability and walking by age group and population center size in Canada.

    Science.gov (United States)

    Wasfi, Rania; Steinmetz-Wood, Madeleine; Kestens, Yan

    2017-01-01

    This study examined the influence of walkability on walking behaviour and assessed whether associations varied according to life-stage and population center (PC) size. Walkability scores were obtained for the six-digit postal codes of residential neighbourhoods of 11,200 Canadians, who participated in biennial assessments of the National Population Health Survey from 1994 to 2010. Participants were stratified by age-group. Mixed-effects logistic regression models were used to estimate the influence of cumulative exposure to neighborhood walkability on utilitarian and exercise walking by PC size and life-stage. Associations of neighbourhood walkability with utilitarian and exercise walking varied according to age-group and PC size. Exposure to high walkable neighborhoods was associated with utilitarian walking in younger and older adults in all PC sizes, except for older adults living in a medium PC. Living in a highly walkable neighborhood in a large PC was associated with walking for exercise in younger (OR: 1.42; 95%CI: 1.20-1.67) and older adults (OR: 2.09; 95%CI: 1.51-2.89). Living in highly walkable neighbourhood in a medium PC was associated with walking for exercise in older adults (OR: 1.62; 95%CI: 1.15-2.29). These results emphasize the need to consider the size and nature of every community, and the age-group of a population when implementing strategies to promote walking.

  16. A comparison of cosmological models using time delay lenses

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio, E-mail: jjwei@pmo.ac.cn, E-mail: xfwu@pmo.ac.cn, E-mail: fmelia@email.arizona.edu [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-06-20

    The use of time-delay gravitational lenses to examine the cosmological expansion introduces a new standard ruler with which to test theoretical models. The sample suitable for this kind of work now includes 12 lens systems, which have thus far been used solely for optimizing the parameters of ΛCDM. In this paper, we broaden the base of support for this new, important cosmic probe by using these observations to carry out a one-on-one comparison between competing models. The currently available sample indicates a likelihood of ∼70%-80% that the R {sub h} = ct universe is the correct cosmology versus ∼20%-30% for the standard model. This possibly interesting result reinforces the need to greatly expand the sample of time-delay lenses, e.g., with the successful implementation of the Dark Energy Survey, the VST ATLAS survey, and the Large Synoptic Survey Telescope. In anticipation of a greatly expanded catalog of time-delay lenses identified with these surveys, we have produced synthetic samples to estimate how large they would have to be in order to rule out either model at a ∼99.7% confidence level. We find that if the real cosmology is ΛCDM, a sample of ∼150 time-delay lenses would be sufficient to rule out R {sub h} = ct at this level of accuracy, while ∼1000 time-delay lenses would be required to rule out ΛCDM if the real universe is instead R {sub h} = ct. This difference in required sample size reflects the greater number of free parameters available to fit the data with ΛCDM.

  17. A comparison of cosmological models using time delay lenses

    International Nuclear Information System (INIS)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio

    2014-01-01

    The use of time-delay gravitational lenses to examine the cosmological expansion introduces a new standard ruler with which to test theoretical models. The sample suitable for this kind of work now includes 12 lens systems, which have thus far been used solely for optimizing the parameters of ΛCDM. In this paper, we broaden the base of support for this new, important cosmic probe by using these observations to carry out a one-on-one comparison between competing models. The currently available sample indicates a likelihood of ∼70%-80% that the R h = ct universe is the correct cosmology versus ∼20%-30% for the standard model. This possibly interesting result reinforces the need to greatly expand the sample of time-delay lenses, e.g., with the successful implementation of the Dark Energy Survey, the VST ATLAS survey, and the Large Synoptic Survey Telescope. In anticipation of a greatly expanded catalog of time-delay lenses identified with these surveys, we have produced synthetic samples to estimate how large they would have to be in order to rule out either model at a ∼99.7% confidence level. We find that if the real cosmology is ΛCDM, a sample of ∼150 time-delay lenses would be sufficient to rule out R h = ct at this level of accuracy, while ∼1000 time-delay lenses would be required to rule out ΛCDM if the real universe is instead R h = ct. This difference in required sample size reflects the greater number of free parameters available to fit the data with ΛCDM.

  18. Comparison of primary and delayed primary closure in dirty abdominal wounds in terms of frequency of surgical site infection

    International Nuclear Information System (INIS)

    Aziz, O.B.A.; Ahmed, N.; Butt, M.W.U.D.; Saleem, M.R.

    2013-01-01

    Objective: Objective of this study was to compare primary and delayed primary wound closure for dirty abdominal wounds in terms of frequency of surgical site infection. Study Design: Randomized Controlled Trial. Place and Duration of Study: Combined Military Hospital, Multan. From 16 Sep 2010 to 15 Mar 2011. Patients and Methods: A total of 110 patients were randomly divided into two groups of 55 patients each using random numbers table. Abdominal wounds of one group were closed primarily and of other group were subjected to delayed primary wound closure. The wounds were then checked for surgical site infection for seven post operative days. Results: A higher frequency of surgical site infection was observed in primary closure group (27.3%) as compared to delayed primary closure group (9.1%) which was statistically significant (p=0.013). Conclusion: Delayed primary closure is superior to primary closure in dirty abdominal wounds in terms of frequency of surgical site infection. (author)

  19. Reward acts as a signal to control delay-period activity in delayed-response tasks.

    Science.gov (United States)

    Ichihara-Takeda, Satoe; Takeda, Kazuyoshi; Funahashi, Shintaro

    2010-03-31

    Prefrontal delay-period activity represents a neural mechanism for the active maintenance of information and needs to be controlled by some signal to appropriately operate working memory. To examine whether reward-delivery acts as this signal, the effects of delay-period activity in response to unexpected reward-delivery were examined by analyzing single-neuron activity recorded in the primate dorsolateral prefrontal cortex. Among neurons that showed delay-period activity, 34% showed inhibition of this activity in response to unexpected reward-delivery. The delay-period activity of these neurons was affected by the expectation of reward-delivery. The strength of the reward signal in controlling the delay-period activity is related to the strength of the effect of reward information on the delay-period activity. These results indicate that reward-delivery acts as a signal to control delay-period activity.

  20. Praeoperativt delay hos patienter med perforeret ulcus: en klinisk audit fra Det Nationale Indikatorprojekt

    DEFF Research Database (Denmark)

    Møller, Morten Hylander; Nørgård, Bente Mertz; Mehnert, Frank

    2009-01-01

    size, this audit suggests that long preoperative delay in patients with peptic ulcer perforation is associated with factors related to both the internal organisation of the healthcare system, the patient's pathological picture, and the quality of diagnosis and treatment given. Udgivelsesdato: 2009-Nov......INTRODUCTION: Mortality following perforated peptic ulcer in Denmark is nearly 30%. Delayed surgery is a prognostic factor, but only half of the patients are operated within six hours of perforation - a predefined quality of care criterion in The Danish National Indicator Project. A clinical audit...

  1. Delay Discounting of Losses in Alcohol Use Disorders and Antisocial Psychopathology: Effects of a Working Memory Load.

    Science.gov (United States)

    Gerst, Kyle R; Gunn, Rachel L; Finn, Peter R

    2017-10-01

    Alcohol use disorders (AUDs) are associated with increased discounting of delayed rewards and reduced executive working memory (eWM) capacity. This association is amplified when comorbid with antisocial psychopathology (AP). Furthermore, recent studies suggest that reduced WM capacity is associated with disinhibited decisions reflected by increased impulsive decision making on the delay discounting of rewards task. While discounting of delayed rewards is well studied, the discounting of delayed losses has received significantly less experimental attention. The current study investigated (i) the rate of discounting of delayed losses in individuals with AUD only (n = 61), AUD with comorbid AP (n = 79) and healthy controls (n = 64); (ii) the relationship between eWM capacity and discounting of delayed losses; and (iii) the effect of a WM load on discounting of delayed losses. Discounting performance was assessed using a computerized discounting of delayed losses task. Results showed that the AUD-only and AUD-AP groups had higher rates of discounting of delayed losses and lower eWM capacity compared to the control groups. Lower individual eWM capacity was associated with increased discounting of delayed losses. However, WM load did not increase discounting rates overall. These results support the hypothesis that greater discounting of delayed losses is associated with AUD and comorbid AP problems and lower individual eWM capacity. Copyright © 2017 by the Research Society on Alcoholism.

  2. Circadian phase, dynamics of subjective sleepiness and sensitivity to blue light in young adults complaining of a delayed sleep schedule.

    Science.gov (United States)

    Moderie, Christophe; Van der Maren, Solenne; Dumont, Marie

    2017-06-01

    To assess factors that might contribute to a delayed sleep schedule in young adults with sub-clinical features of delayed sleep phase disorder. Two groups of 14 young adults (eight women) were compared: one group complaining of a delayed sleep schedule and a control group with an earlier bedtime and no complaint. For one week, each subject maintained a target bedtime reflecting their habitual sleep schedule. Subjects were then admitted to the laboratory for the assessment of circadian phase (dim light melatonin onset), subjective sleepiness, and non-visual light sensitivity. All measures were timed relative to each participant's target bedtime. Non-visual light sensitivity was evaluated using subjective sleepiness and salivary melatonin during 1.5-h exposure to blue light, starting one hour after target bedtime. Compared to control subjects, delayed subjects had a later circadian phase and a slower increase of subjective sleepiness in the late evening. There was no group difference in non-visual sensitivity to blue light, but we found a positive correlation between melatonin suppression and circadian phase within the delayed group. Our results suggest that a late circadian phase, a slow build-up of sleep need, and an increased circadian sensitivity to blue light contribute to the complaint of a delayed sleep schedule. These findings provide targets for strategies aiming to decreasing the severity of a sleep delay and the negative consequences on daytime functioning and health. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Two-actor conflict with time delay: A dynamical model

    Science.gov (United States)

    Qubbaj, Murad R.; Muneepeerakul, Rachata

    2012-11-01

    Recent mathematical dynamical models of the conflict between two different actors, be they nations, groups, or individuals, have been developed that are capable of predicting various outcomes depending on the chosen feedback strategies, initial conditions, and the previous states of the actors. In addition to these factors, this paper examines the effect of time delayed feedback on the conflict dynamics. Our analysis shows that under certain initial and feedback conditions, a stable neutral equilibrium of conflict may destabilize for some critical values of time delay, and the two actors may evolve to new emotional states. We investigate the results by constructing critical delay surfaces for different sets of parameters and analyzing results from numerical simulations. These results provide new insights regarding conflict and conflict resolution and may help planners in adjusting and assessing their strategic decisions.

  4. Delayed healing of corneal epithelium after phototherapeutic keratectomy for lattice dystrophy.

    Science.gov (United States)

    Das, Sujata; Langenbucher, Achim; Seitz, Berthold

    2005-04-01

    To evaluate the time period necessary for complete epithelial healing after phototherapeutic keratectomy (o-PTK) carried out for various superficial corneal opacities. A total of 197 eyes were divided into 9 groups: group 1, Cogan dystrophy including recurrences (n = 15); group 2, Reis Bucklers dystrophy including recurrences (n = 12); group 3, granular dystrophy including recurrences (n = 63); group 4, lattice dystrophy including recurrences (n = 19); group 5, macular dystrophy including recurrences (n = 10); group 6, herpetic scars (n = 5); group 7, corneal scars of nonherpetic origin (including scrofulous, traumatic, central keratoconus, post-pterygium surgery) (n = 31); group 8, Salzmann nodular degeneration (n = 22); and group 9, miscellaneous (such as bullous keratopathy, acute chemical burn, corneal degeneration) (n = 20). After o-PTK, patients were examined daily at the slit lamp using fluorescein and blue light. The time period necessary for complete healing of the epithelial defect was compared among these groups. Delayed healing was considered where the epithelium was not closed after 7 days. One hundred sixty-one eyes (95%) healed within 7 days. Overall, 63%, 80%, and 85% of epithelial defects were closed within 3, 4, and 5 days, respectively. Out of 9 eyes that had delayed healing, 6 eyes (67%) belonged to lattice dystrophy category. Mean time taken for healing in group 4 (8.6 +/- 8.4 days) was significantly longer than those in group 1 (3.0 +/- 1.5 days, P = 0.009), group 2 (3.7 +/- 3.1 days, P = 0.03), group 3 (3.1 +/- 1.5 days, P = 0.001), group 5 (2.7 +/- 0.8 days, P = 0.01), group 7 (3.6 +/- 2.4 days, P = 0.007), group 8 (3.3 +/- 1.3 days, P = 0.009), and group 9 (3.0 +/- 1.9 days, P = 0.011). Eyes with lattice corneal dystrophy suffered from delayed epithelial healing after o-PTK. In addition to adequate counseling, these patients should be followed up closely until complete closure of the epithelium to avoid ulceration, scarring, or even

  5. Comparison of Early and Delayed Open Reduction and Internal Fixation for Treating Closed Tibial Pilon Fractures.

    Science.gov (United States)

    Tang, Xin; Liu, Lei; Tu, Chong-qi; Li, Jian; Li, Qi; Pei, Fu-xing

    2014-07-01

    The timing of surgery for osteosynthesis of type C pilon (AO/OTA) fractures remains controversial. The aim of this study was to determine the outcome of early and delayed open reduction and internal fixation (ORIF) for treating closed type C pilon fractures. Forty-six patients with closed type C pilon fractures matched according to age, gender, soft tissue conditions, and fracture pattern were divided into group A (early group: underwent surgery within 36 hours of the injury) or group B (delayed group: underwent surgery 10 days to 3 weeks postinjury after the soft tissue swelling subsided). In the delayed group, 9 patients were treated first by temporary external fixation. All the closed fractures were managed by ORIF with locking plates. At follow-up, the clinical and radiographic results were retrospectively analyzed. The mean follow-up time was 25.8 months (range, 14 to 48 months) in group A and 26.0 months (range, 15 to 44 months) in group B. There was no significant difference (P > .05) between the 2 groups regarding the rate of soft tissue complication, the rate of fracture union, and the final functional score. The patients in group A had a significantly shorter mean time to fracture union (21.5 ± 4.0 weeks vs 23.3 ± 3.7 weeks, P fractures can be safe and effective, with similar rates of wound complication, fracture union, and final good functional recovery but shorter operative time, union time, and hospital stay. These results favorably compare with delayed ORIF treatment. Level III, retrospective comparative study. © The Author(s) 2014.

  6. Assessing delay discounting in mice

    OpenAIRE

    Mitchell, Suzanne H.

    2014-01-01

    Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

  7. Modelling delays in pharmacokinetics

    International Nuclear Information System (INIS)

    Farooqi, Z.H.; Lambrecht, R.M.

    1990-01-01

    Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

  8. Risk-factors for surgical delay following hip fracture.

    Science.gov (United States)

    Sanz-Reig, J; Salvador Marín, J; Ferrández Martínez, J; Orozco Beltrán, D; Martínez López, J F

    To identify pre-operative risk factors for surgical delay of more than 2 days after admission in patients older than 65 years with a hip fracture. A prospective observational study was conducted on 180 hip fractures in patients older than 65 years of age admitted to our hospital from January 2015 to April 2016. The data recorded included, patient demographics, day of admission, pre-fracture comorbidities, mental state, level of mobility and physical function, type of fracture, antiaggregant and anticoagulant medication, pre-operative haemoglobin value, type of treatment, and surgical delay. The mean age of the patients was 83.7 years. The mean Charlson Index was 2.8. The pre-fracture baseline co-morbidities were equal or greater than 2 in 70% of cases. Mean timing of surgery was 3.1 days. At the time of admission, 122 (67.7%) patients were fit for surgery, of which 80 (44.4%) underwent surgery within 2 days. A Charlson index greater than 2, anticoagulant therapy, and admission on Thursday to Saturday, were independently associated with a surgical delay greater than 2 days. The rate of hip fracture patients undergoing surgery within 2 days is low. Risk factors associated to surgical delay are non-modifiable. However, their knowledge should allow the development of protocols that can reduce surgical delay in this group of patients. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Stochastic nonlinear time series forecasting using time-delay reservoir computers: performance and universality.

    Science.gov (United States)

    Grigoryeva, Lyudmila; Henriques, Julie; Larger, Laurent; Ortega, Juan-Pablo

    2014-07-01

    Reservoir computing is a recently introduced machine learning paradigm that has already shown excellent performances in the processing of empirical data. We study a particular kind of reservoir computers called time-delay reservoirs that are constructed out of the sampling of the solution of a time-delay differential equation and show their good performance in the forecasting of the conditional covariances associated to multivariate discrete-time nonlinear stochastic processes of VEC-GARCH type as well as in the prediction of factual daily market realized volatilities computed with intraday quotes, using as training input daily log-return series of moderate size. We tackle some problems associated to the lack of task-universality for individually operating reservoirs and propose a solution based on the use of parallel arrays of time-delay reservoirs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Contrast enhancement of focal hepatic lesions in CT: effect of size and histology

    International Nuclear Information System (INIS)

    Burgener, F.A.; Hamlin, D.J.

    1983-01-01

    The effect of size and histology on the contrast enhancement of hepatic lesions has been analyzed in this clinical and experimental investigation yielding the following results: (1) The attenuation values of hepatic cysts in patients increase significantly and inversely with their size after contrast enhancement when the cysts measure less than twice the CT-slice thickness. This seems to be caused by partial-volume effect. (2) Experimental tumors of identical sizes and originating from the same cell line can demonstrate different contrast-enhancement patterns. (3) Peak contrast uptake in both experimental and human tumors seems to be inversely related to their size. (4) Compared to liver, contrast washout from experimental and human tumors (presumably the extravascular space) is delayed. The delay in the contrast washout from a tumor seems to correlate with tumor size. These findings suggest that in general, it is not possible to differentiate reliably among various hepatic neoplasms on the basis of their contrast enhancement patterns for the following reasons: (1) Attenuation values of small hepatic neoplasms are distorted by partial volume effect. (2) Tumors of different histologies can demonstrate the same enhancement pattern. (3) Tumors of identical histology and size can demonstrate different enhancement patterns. (4) The enhancement pattern of a tumor changes with growth or size

  11. REASONS FOR PATIENT DELAYS & HEALTH SYSTEM DELAYS FOR TUBERCULOSIS IN SOUTH INDIA

    Directory of Open Access Journals (Sweden)

    Kapil Goel

    2011-12-01

    Full Text Available Background: Globally, the burden of Tuberculosis is escalating. Early diagnosis and prompt initiation of tuberculosis treatment is essential for an effective tuberculosis control programme. Objectives: To study the self reported reasons for patient and health system (diagnosis & treatment delays in Tuberculosis patients. Methods: A community based cross sectional study was conducted among 98 new sputum positive TB cases aged > 15 years registered under RNTCP from Oct 2006 to June 2007 & receiving treatment under DOTS in Udupi taluk by interviewing them. Results: Total 98 patients were recruited and 68% were males. Out of 17 patients with patient delays, 82% felt that their symptoms were not severe, 71% felt that patient delay was due to lack of awareness and 71% did not take it seriously. Out of 86 patients with health system delays, 82.6% of patients mentioned that doctor has not advised for sputum examination, 76.7% of patients told that they first consulted a private doctor, 21% of them mentioned that doctor was unaware to diagnose TB. Conclusion: Symptoms not severe is the main reason for the patient delay and doctor didn’t advise for sputum examination is the main reason for health system delays.

  12. Delayed traumatic hematomas of the brain: the early manifestations of CT

    International Nuclear Information System (INIS)

    Liu Shuyan; Tang Guangjian; Fu Jiazhen; Xu Bing; Yin Yanyu

    2002-01-01

    Objective: To study the CT manifestations of delayed traumatic hematomas of the brain and evaluate their diagnostic significance in predicting the delayed traumatic brain hematoma. Methods: The manifestations of initial CT studies and follow-up CT examinations of 31 delayed traumatic brain hematomas were analyzed. Another 50 CT studies of head trauma without delayed brain hematomas were included randomly as control. Results: The abnormal findings of CT studies of the 31 delayed traumatic brain hematomas included: (1) Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 18 cases; (2) Local subarachnoid space hemorrhage in 24 cases; (3) Slight mass effect of local brain parenchyma in 16 cases. (4) Subdural hematoma in 9 cases. The locations of the abnormalities were roughly the same with the delayed hematoma except one local subarachnoid space hemorrhage, which was in the opposite of the delayed hematoma. The appearing rate of those abnormal findings in the control group was low and the difference was statistically significant. Conclusion: The decrease of density of local brain parenchyma, the disappeared difference between the gray and white matter, local subarachnoid space hemorrhage, and local swollen of brain presented in the initial CT study of the patient with heat trauma should be taken as indicators of delayed hemorrhage of the same area of brain, and it is necessary to do follow-up CT studies to exclude it

  13. The Number of Cultural Traits Is Correlated with Female Group Size but Not with Male Group Size in Chimpanzee Communities

    OpenAIRE

    Lind, Johan; Lindenfors, Patrik

    2010-01-01

    What determines the number of cultural traits present in chimpanzee (Pan troglodytes) communities is poorly understood. In humans, theoretical models suggest that the frequency of cultural traits can be predicted by population size. In chimpanzees, however, females seem to have a particularly important role as cultural carriers. Female chimpanzees use tools more frequently than males. They also spend more time with their young, skewing the infants’ potential for social learning towards their ...

  14. Delayed orgasm and anorgasmia.

    Science.gov (United States)

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Influence of food availability on the diet and activity budget of two western lowland gorilla (Gorilla gorilla gorilla) groups of differing size in the Dzanga-Ndoki National Park, Central African Republic

    OpenAIRE

    Neba, Terence Fuh; Donati, Giuseppe; Todd, Angelique; Masi, Shelly

    2014-01-01

    Variation in food availability, body size and group size are known to influence primate diet and activity budgets. Here we report how seasonal food availability shapes the diet and activity patterns of two habituated western lowland gorilla (WLG) groups of differing size. WLGs are ripe fruit opportunists, showing dietary flexibility when preferred foods are scarce. However, as fruit can be rare/ patchily distributed, as intra-group feeding competition increases with group size, access to indi...

  16. On the Expected Discounted Penalty Function for the Classical Risk Model with Potentially Delayed Claims and Random Incomes

    Directory of Open Access Journals (Sweden)

    Huiming Zhu

    2014-01-01

    Full Text Available We focus on the expected discounted penalty function of a compound Poisson risk model with random incomes and potentially delayed claims. It is assumed that each main claim will produce a byclaim with a certain probability and the occurrence of the byclaim may be delayed depending on associated main claim amount. In addition, the premium number process is assumed as a Poisson process. We derive the integral equation satisfied by the expected discounted penalty function. Given that the premium size is exponentially distributed, the explicit expression for the Laplace transform of the expected discounted penalty function is derived. Finally, for the exponential claim sizes, we present the explicit formula for the expected discounted penalty function.

  17. Effect of a comprehensive health education program on pre-hospital delay intentions in high-risk stroke population and caregivers.

    Science.gov (United States)

    Yang, Li; Zhao, Qiuli; Zhu, Xuemei; Shen, Xiaoying; Zhu, Yulan; Yang, Liu; Gao, Wei; Li, Minghui

    2017-08-01

    Many factors influence pre-hospital delays in the event of stroke. This study aimed to develop and evaluate a comprehensive educational program for decreasing pre-hospital delays in high-risk stroke population. We enrolled 220 high-risk stroke population and caregivers from six urban communities in Harbin from May 2013 to May 2015, and randomly divided them into intervention and control groups. We implemented a comprehensive educational program (intervention group), comprising public lectures, instructional brochures, case videos, simulations, and role-playing from May 2013 to May 2015. We delivered conventional oral education in the control group. We compared stroke pre-hospital delay behavioral intention (SPDBI), pre-hospital stroke symptom coping test (PSSCT), and stroke pre-symptoms alert test (SPSAT) results between the groups before and 6, 12, and 18 months after health intervention. There were significant differences between before and after intervention (P educational program was significantly effective in decreasing SPDBI, improving knowledge, enhancing stroke pre-symptoms alert, and reducing the possibility of pre-hospital delays.

  18. Imprints of the quasar structure in time-delay light curves: Microlensing-aided reverberation mapping

    Science.gov (United States)

    Sluse, D.; Tewes, M.

    2014-11-01

    The advent of large area photometric surveys has raised a great deal of interest in the possibility of using broadband photometric data, instead of spectra, to measure the size of the broad line region of active galactic nuclei. We describe here a new method that uses time-delay lensed quasars where one or several images are affected by microlensing due to stars in the lensing galaxy. Because microlensing decreases (or increases) the flux of the continuum compared to the broad line region, it changes the contrast between these two emission components. We show that this effect can be used to effectively disentangle the intrinsic variability of those two regions, offering the opportunity to perform reverberation mapping based on single-band photometric data. Based on simulated light curves generated using a damped random walk model of quasar variability, we show that measurement of the size of the broad line region can be achieved using this method, provided one spectrum has been obtained independently during the monitoring. This method is complementary to photometric reverberation mapping and could also be extended to multi-band data. Because the effect described above produces a variability pattern in difference light curves between pairs of lensed images that is correlated with the time-lagged continuum variability, it can potentially produce systematic errors in measurement of time delays between pairs of lensed images. Simple simulations indicate that time-delay measurement techniques that use a sufficiently flexible model for the extrinsic variability are not affected by this effect and produce accurate time delays.

  19. Buffer sizing for multi-hop networks

    KAUST Repository

    Shihada, Basem

    2014-01-28

    A cumulative buffer may be defined for an interference domain in a wireless mesh network and distributed among nodes in the network to maintain or improve capacity utilization of network resources in the interference domain without increasing packet queuing delay times. When an interference domain having communications links sharing resources in a network is identified, a cumulative buffer size is calculated. The cumulative buffer may be distributed among buffers in each node of the interference domain according to a simple division or according to a cost function taking into account a distance of the communications link from the source and destination. The network may be monitored and the cumulative buffer size recalculated and redistributed when the network conditions change.

  20. Analysis and control of issues that delay pharmaceutical projects

    Directory of Open Access Journals (Sweden)

    Nallam Sai Nandeswara Rao

    2015-10-01

    Full Text Available Every project will have certain objectives and service levels to be achieved. The success of a project depends on several dimensions like time, cost/budget, quality, etc. and managing a project involves completing the project within time, within budget and with quality to satisfy the users. Because of the significance of health, pharmaceutical companies realized the importance of project management methods and techniques to make available the life saving drugs in time to the needy patients and hospitals. In literature, there is meager information about pharmaceutical project management oriented towards analysis of issues and factors that contribute to the failure or success of projects. This study attempts to analyse different issues that contribute to time delays in pharmaceutical product-based projects, group them under a finite set of prominent factors and identify remedial measures to control those delays. The feedback of project people of some big pharmaceutical firms of Indian sub-continent was collected for this purpose. Exploratory factor analysis (EFA has been used to reduce the reasons for time delays to a limited number of prominent factors and the EFA model has been further examined by confirmatory factor analysis (CFA for its validation. Remedial measures under each factor of time delays have been gathered and a framework designed to mitigate the time delays in pharmaceutical projects. The derived factors that delay the pharmaceutical projects include resource, monitoring & control, scheduling and planning problems. Important remedial measures like blended resource approach, estimation and forecast of shortage of labour and skills, regular quality training, etc. have been recommended.

  1. Delay-dependent stability of neural networks of neutral type with time delay in the leakage term

    International Nuclear Information System (INIS)

    Li, Xiaodi; Cao, Jinde

    2010-01-01

    This paper studies the global asymptotic stability of neural networks of neutral type with mixed delays. The mixed delays include constant delay in the leakage term (i.e. 'leakage delay'), time-varying delays and continuously distributed delays. Based on the topological degree theory, Lyapunov method and linear matrix inequality (LMI) approach, some sufficient conditions are derived ensuring the existence, uniqueness and global asymptotic stability of the equilibrium point, which are dependent on both the discrete and distributed time delays. These conditions are expressed in terms of LMI and can be easily checked by the MATLAB LMI toolbox. Even if there is no leakage delay, the obtained results are less restrictive than some recent works. It can be applied to neural networks of neutral type with activation functions without assuming their boundedness, monotonicity or differentiability. Moreover, the differentiability of the time-varying delay in the non-neutral term is removed. Finally, two numerical examples are given to show the effectiveness of the proposed method

  2. Clinical review: Distinguishing constitutional delay of growth and puberty from isolated hypogonadotropic hypogonadism: critical appraisal of available diagnostic tests.

    Science.gov (United States)

    Harrington, Jennifer; Palmert, Mark R

    2012-09-01

    Determining the etiology of delayed puberty during initial evaluation can be challenging. Specifically, clinicians often cannot distinguish constitutional delay of growth and puberty (CDGP) from isolated hypogonadotropic hypogonadism (IHH), with definitive diagnosis of IHH awaiting lack of spontaneous puberty by age 18 yr. However, the ability to make a timely, correct diagnosis has important clinical implications. The aim was to describe and evaluate the literature regarding the ability of diagnostic tests to distinguish CDGP from IHH. A PubMed search was performed using key words "puberty, delayed" and "hypogonadotropic hypogonadism," and citations within retrieved articles were reviewed to identify studies that assessed the utility of basal and stimulation tests in the diagnosis of delayed puberty. Emphasis was given to a test's ability to distinguish prepubertal adolescents with CDGP from those with IHH. Basal gonadotropin and GnRH stimulation tests have limited diagnostic specificity, with overlap in gonadotropin levels between adolescents with CDGP and IHH. Stimulation tests using more potent GnRH agonists and/or human chorionic gonadotropin may have better discriminatory value, but small study size, lack of replication of diagnostic thresholds, and prolonged protocols limit clinical application. A single inhibin B level in two recent studies demonstrated good differentiation between groups. Distinguishing IHH from CDGP is an important clinical issue. Basal inhibin B may offer a simple, discriminatory test if results from recent studies are replicated. However, current literature does not allow for recommendation of any diagnostic test for routine clinical use, making this an important area for future investigation.

  3. Factors influencing diagnosis delay of advanced breast cancer in Moroccan women.

    Science.gov (United States)

    Maghous, A; Rais, F; Ahid, S; Benhmidou, N; Bellahamou, K; Loughlimi, H; Marnouche, E; Elmajjaoui, S; Elkacemi, H; Kebdani, T; Benjaafar, N

    2016-06-07

    Delay in the diagnosis of breast cancer in symptomatic women of 3 months or more is associated with advanced stage and low survival. We conducted this study to learn more about the extent and reasons behind diagnosis delay of advanced breast cancer in Moroccan women. A group of patients with advanced breast cancer were interviewed at the National Institute of Oncology in Rabat during the period from February to December 2014. Diagnosis delay was devised into patient delay and system delay. Patient delay was defined as time from first symptoms until first medical consultation. System delay was defined as time from first presentation to a health care provider until definite diagnosis or treatment. Prospective information and clinical data were collected on a form during an interview with each patient and from medical records. In all, 137 patients were interviewed. The mean age of women was 48.3 ± 10.4 years. The median of consultation time was 6[4,12] months and the median of diagnosis time was 1[1,3] months. Diagnosis delay was associated to a personal reason in 96 (70.1 %) patients and to a medical reason in 19 (13.9 %) patients. A number of factors predicted diagnosis delay: symptoms were not considered serious in 66 (55.9 %) patients; traditional therapy was applied in 15 (12.7 %) patients and fear of cancer diagnosis and/or treatment in 14 (11.9 %) patients. A use of traditional methods was significantly associated with rural residence and far away from basic health center (p = 0.000). Paradoxically, a family history of breast cancer was significantly higher in who report a fear of cancer diagnosis and/or treatment to diagnosis delay (p Diagnosis delay is very serious problem in Morocco. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer information in our populations and training of general practitioners to reduce advanced breast cancer by

  4. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  5. Delayed Orgasm and Anorgasmia

    OpenAIRE

    Jenkins, Lawrence C.; Mulhall, John P.

    2015-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, ...

  6. The TCD50 and regrowth delay assay in human tumor xenografts: Differences and implications

    International Nuclear Information System (INIS)

    Budach, W.; Budach, V.; Stuschke, M.; Dinges, S.; Sack, H.

    1993-01-01

    The response to irradiation of five human xenograft cell lines - a malignant paraganglioma, a neurogenic sarcoma, a malignant histiocytoma, a primary lymphoma of the brain, and a squamous cell carcinoma - were tested in nude mice. All mice underwent 5 Gy whole body irradiation prior to xenotransplantation to minimize the residual immune response. The subcutaneous tumors were irradiated at a tumor volume of 120 mm 3 under acutely hypoxic conditions with single doses between 8 Gy and 80 Gy depending on the expected radiation sensitivity of the tumor line. Endpoints of the study were the tumor control dose 50% (TCD 50 ) and the regrowth delay endpoints growth delay, specific growth delay, and the tumor bed effect corrected specific growth delay. Specific growth delay and corrected specific growth delay at 76% of the TCD 50 was used in order to compare the data to previously published data from spheroids. The lowest TCD 50 was found in the lymphoma with 24.9 Gy, whereas the TCD 50 of the soft tissue sarcomas and the squamous cell carcinoma ranged from 57.8 Gy to 65.6 Gy. The isoeffective dose levels for the induction of 30 days growth delay, a specific growth delay of 3, and a corrected specific growth delay of 3 ranged from 15.5 Gy (ECL1) to 37.1 Gy (FADU), from 7.2 Gy (ENE2) to 45.6 Gy (EPG1) and from 9.2 Gy (ENE2) to 37.6 Gy (EPG1), respectively. The corrected specific growth delay at 76% of the TCD 50 was correlated with the number of tumor rescue units per 100 cells in spheroids, which was available for three tumor lines, and with the tumor doubling time in xenografts (n = 5). The TCD 50 values corresponded better to the clinical experience than the regrowth delay data. There was no correlation between TCD 50 and any of the regrowth delay endpoints. This missing correlation was most likely a result of large differences in the number of tumor rescue units in human xenografts of the same size

  7. Survival analysis for predictive factors of delay vaccination in Iranian children

    Directory of Open Access Journals (Sweden)

    Abolfazl Mohammadbeigi

    2015-01-01

    Full Text Available Background: Today, beside immunization coverage the age appropriate vaccination is another helpful index in public health. Evidences have shown that high immunization coverage rates do not necessarily imply age-appropriate vaccination status. The current study aimed to show the predictive factors of delayed vaccination by survival models. Methods: A historical cohort study conducted on 3610 children aged between 24 and 47 months who was living in the suburbs of five big cities of Iran. Time of delay in vaccination of first dose of mumps-measles-rubella (MMR was calculated from date of vaccination minus age appropriate time according to vaccine card. Kaplan-Maier and Log rank tests were used for comparison the median of delay time. For controlling of confounding variables, multivariate cox model was used and hazard ratio with 95% confidence interval (95% was reported. Results: The mean ± standard deviation and median interquartile range of delay time was 38.34 ± 73.1 and 16 (11-31 days in delayed group. The Log rank test showed that city of living, nationality, parents′ education, and birth order are related with prolonged delay time in MMR vaccination (P 0.05. Cox regression showed that city of living, mother education, and nationality are the most predictive factors of delay time duration in MMR vaccination. Conclusions: Delay time duration of vaccination increased by faring from capital to the east south. Moreover, concentration of foreign immigrants in big cities and low level of mother education are the most predictors of delayed vaccination. Educational intervention should focus on immigrants and mothers with low education level.

  8. Radiation cell survival and growth delay studies in multicellular spheroids of small-cell lung carcinoma

    International Nuclear Information System (INIS)

    Duchesne, G.M.; Peacock, J.H.

    1987-01-01

    The radiation sensitivity of two small-cell lung carcinoma cell lines growing as multicellular spheroids in static culture was determined using clonogenic cell survival and growth delay as endpoints. Growth delay determination suggested that clonogenic cell kill was less than was obtained by direct assay of cell survival. Recovery from potentially lethal damage was assayed in one line (HC12) but was not demonstrable, and clonogenic cell survival decreased with time in treated spheroids with diameters greater than 300 μm which contained a hypoxic cell population. Microscopic examination of the treated spheroids showed the emergence of an abnormal giant-cell population, and the progressive clonogenic cell loss that occurred after treatment was thought to be due to oxygen and nutrient deprivation of the remaining viable cells by this doomed cell population. Correction of the growth delay measurements for changes in cell size and clonogenic cell population allowed correlation of the growth delay and cell survival data. (author)

  9. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    Science.gov (United States)

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  10. Effects of delayed polymerization time and bracket manipulation on orthodontic resin modified glass ionomer adhesive

    Science.gov (United States)

    Gilbert, Danielle Wiggins

    This study examined the effect of varying delayed polymerization times in combination with bracket manipulation on shear bond strength (SBS), degree of conversion (DC), and adhesive remnant index (ARI) score when using a resin modified glass ionomer (RMGI) adhesive. Specimens were divided into three groups of clinically relevant delay times (0.5, 2, and 4-min) to simulate the delay that frequently occurs between bracket placement and manipulation and subsequent light curing. Based on an analysis of variance (alpha=.05), the SBS was not significantly different between the three groups. While one of the goals of this study was to be the first study to quantify DC of RMGI using Raman microspectroscopy, several challenges, including weak peak signal with and without fluorescence, were encountered and as a result, DC could not be determined. A significant difference (pbracket with increasing delay time. A Spearman correlation between SBS and ARI indicated no positive association between SBS and ARI measures across delay times. The results of this study suggest that clinically relevant delay times of 0.5, 2, and 4-min do not negatively impact the SBS of a RMGI adhesive. However, with increasing delay time, the results suggest that more adhesive might remain on the bracket during debonding. With more adhesive remaining on the bracket, this could be beneficial in that less adhesive needs to be removed from enamel by grinding at the time of bracket removal when orthodontic treatment is completed.

  11. Attosecond Delays in Molecular Photoionization.

    Science.gov (United States)

    Huppert, Martin; Jordan, Inga; Baykusheva, Denitsa; von Conta, Aaron; Wörner, Hans Jakob

    2016-08-26

    We report measurements of energy-dependent photoionization delays between the two outermost valence shells of N_{2}O and H_{2}O. The combination of single-shot signal referencing with the use of different metal foils to filter the attosecond pulse train enables us to extract delays from congested spectra. Remarkably large delays up to 160 as are observed in N_{2}O, whereas the delays in H_{2}O are all smaller than 50 as in the photon-energy range of 20-40 eV. These results are interpreted by developing a theory of molecular photoionization delays. The long delays measured in N_{2}O are shown to reflect the population of molecular shape resonances that trap the photoelectron for a duration of up to ∼110 as. The unstructured continua of H_{2}O result in much smaller delays at the same photon energies. Our experimental and theoretical methods make the study of molecular attosecond photoionization dynamics accessible.

  12. Iterative method for obtaining the prompt and delayed alpha-modes of the diffusion equation

    International Nuclear Information System (INIS)

    Singh, K.P.; Degweker, S.B.; Modak, R.S.; Singh, Kanchhi

    2011-01-01

    Highlights: → A method for obtaining α-modes of the neutron diffusion equation has been developed. → The difference between the prompt and delayed modes is more pronounced for the higher modes. → Prompt and delayed modes differ more in reflector region. - Abstract: Higher modes of the neutron diffusion equation are required in some applications such as second order perturbation theory, and modal kinetics. In an earlier paper we had discussed a method for computing the α-modes of the diffusion equation. The discussion assumed that all neutrons are prompt. The present paper describes an extension of the method for finding the α-modes of diffusion equation with the inclusion of delayed neutrons. Such modes are particularly suitable for expanding the time dependent flux in a reactor for describing transients in a reactor. The method is illustrated by applying it to a three dimensional heavy water reactor model problem. The problem is solved in two and three neutron energy groups and with one and six delayed neutron groups. The results show that while the delayed α-modes are similar to λ-modes they are quite different from prompt modes. The difference gets progressively larger as we go to higher modes.

  13. Virtual unit delay for digital frequency adaptive T/4 delay phase-locked loop system

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2016-01-01

    /processor with a fixed sampling rate considering the cost and complexity, where the number of unit delays that have been adopted should be an integer. For instance, in conventional digital control systems, a single-phase T/4 Delay Phase-Locked Loop (PLL) system takes 50 unit delays (i.e., in a 50-Hz system...... Delay PLL system should be done in its implementation. This process will result in performance degradation in the digital control system, as the exactly required number of delays is not realized. Hence, in this paper, a Virtual Unit Delay (VUD) has been proposed to address such challenges to the digital......Digital micro-controllers/processors enable the cost-effective control of grid-connected power converter systems in terms of system monitoring, signal processing (e.g., grid synchronization), control (e.g., grid current and voltage control), etc. Normally, the control is implemented in a micro-controller...

  14. Effect of group size on performance and egg quality of laying hens during 20 to 36 weeks of age

    Directory of Open Access Journals (Sweden)

    Fulvia Bovera

    2014-03-01

    Full Text Available The aim of this study was to improve knowledge on the effect of group size on productive performance and egg quality of hens raised in furnished cages equally designed. A total of 520, 15-week-old Lohmann Brown laying hens were divided into 2 groups to have a similar initial body weight (average 1392±16.3 g. The cages of S25 group (240 L x 78 W x 50 H cm, 749 cm2/hen hosted a total of 200 hens, while those of S40 group (462 L x 65 W x 50 H, 751 cm2/hen included 320 birds. Experimental data were recorded after an adaptation period of 5 weeks (20 to 36 weeks of age. Hens were submitted to 15 h of light/d. The average temperature inside the building was 24.6±2.5°C over the entire experimental period with higher values at 24, 26, 28 and 30 weeks of age. The relative humidity recorded inside the building was 55% at week 20 and 60% all through the experimental period. Hens raised from S40 group had lower percentage of egg production (84.91 vs 88.90%, P<0.01 and higher feed conversion ratio (2.70 vs 2.25, P<0.0001 than S25 group. The percentage of eggs laid out of the nest was higher in S25 than S40 group (0.26 vs 0.19%, P<0.01. As expected, the week of age affected almost all the parameters (feed intake, body weight, laying percentage, egg weight, yolk, shell and albumen indexes, shell thickness, Haugh unit. However, the effect of group size was particularly evident during the hot period.

  15. Auditory Brainstem Response Wave Amplitude Characteristics as a Diagnostic Tool in Children with Speech Delay with Unknown Causes

    Directory of Open Access Journals (Sweden)

    Susan Abadi

    2016-09-01

    Full Text Available Speech delay with an unknown cause is a problem among children. This diagnosis is the last differential diagnosis after observing normal findings in routine hearing tests. The present study was undertaken to determine whether auditory brainstem responses to click stimuli are different between normally developing children and children suffering from delayed speech with unknown causes. In this cross-sectional study, we compared click auditory brainstem responses between 261 children who were clinically diagnosed with delayed speech with unknown causes based on normal routine auditory test findings and neurological examinations and had >12 months of speech delay (case group and 261 age- and sex-matched normally developing children (control group. Our results indicated that the case group exhibited significantly higher wave amplitude responses to click stimuli (waves I, III, and V than did the control group (P=0.001. These amplitudes were significantly reduced after 1 year (P=0.001; however, they were still significantly higher than those of the control group (P=0.001. The significant differences were seen regardless of the age and the sex of the participants. There were no statistically significant differences between the 2 groups considering the latency of waves I, III, and V. In conclusion, the higher amplitudes of waves I, III, and V, which were observed in the auditory brainstem responses to click stimuli among the patients with speech delay with unknown causes, might be used as a diagnostic tool to track patients’ improvement after treatment.

  16. Diverse Effects of a Seven-Year Experimental Grassland Fragmentation on Major Invertebrate Groups.

    Science.gov (United States)

    Braschler, Brigitte; Baur, Bruno

    2016-01-01

    Habitat fragmentation is a major driver of biodiversity loss, but observed effects vary and may depend on the group examined. Time since fragmentation may explain some differences between taxonomical groups, as some species and thus species composition respond with a delay to changes in their environment. Impacts of drivers of global change may thus be underestimated in short-term studies. In our study we experimentally fragmented nutrient-poor dry calcareous grasslands and studied the response of species richness, individual density and species composition of various groups of invertebrates (gastropods, ants, ground beetles, rove beetles, orthoptera, spiders, woodlice) in 12 small (1.5 m * 1.5 m) and 12 large (4.5 m * 4.5 m) fragments and their corresponding control plots after 7 years. We further examined responses to fragmentation in relation to body size and habitat preferences. Responses to fragmentation varied between taxonomical groups. While spider species richness and individual density were lower in fragments, the opposite was true for an orthopteran species and woodlice. Species composition and β-diversity differed between fragments and control plots for some groups. However, the interaction treatment*plot size was rarely significant. Species with high occupancy rates in undisturbed control plots responded more negatively to the fragmentation, while species with large body size were relatively more abundant in fragments in some groups. No effect of the fragmentation was found for ants, which may have the longest lag times because of long-lived colonies. However, relationships between abundance and the species' preferences for environmental factors affected by edge effects indicate that ant diversity too may be affected in the longer-term. Our results show the importance of considering different groups in conservation management in times of widespread fragmentation of landscapes. While species richness may respond slowly, changes in abundance related to

  17. Information transfer via implicit encoding with delay time modulation in a time-delay system

    Energy Technology Data Exchange (ETDEWEB)

    Kye, Won-Ho, E-mail: whkye@kipo.go.kr [Korean Intellectual Property Office, Government Complex Daejeon Building 4, 189, Cheongsa-ro, Seo-gu, Daejeon 302-701 (Korea, Republic of)

    2012-08-20

    A new encoding scheme for information transfer with modulated delay time in a time-delay system is proposed. In the scheme, the message is implicitly encoded into the modulated delay time. The information transfer rate as a function of encoding redundancy in various noise scales is presented and it is analyzed that the implicit encoding scheme (IES) has stronger resistance against channel noise than the explicit encoding scheme (EES). In addition, its advantages in terms of secure communication and feasible applications are discussed. -- Highlights: ► We propose new encoding scheme with delay time modulation. ► The message is implicitly encoded with modulated delay time. ► The proposed scheme shows stronger resistance against channel noise.

  18. Why do total-body decay curves of iodine-labeled proteins begin with a delay

    International Nuclear Information System (INIS)

    Regoeczi, E.

    1987-01-01

    The initial delay that occurs in total-body radiation curves reaching their single-exponential slopes was analyzed from 106 experiments involving several mammalian species (guinea pig, mouse, rabbit, and rat) and plasma proteins (alpha 1-acid glycoprotein, antithrombin III, fibrinogen, immunoglobulin G, and transferrin) in 14 different combinations. The time interval (Td) between injection and the intercept of the slope with the full-dose value was adopted as a measure of curve nonideality. The overall mean Td was 6.6 h, but individual values showed a significant correlation to protein half-lives, whereby proteins of unequal metabolic properties exhibited different mean Td values. Targeting protein to the liver abolished delay. Choice of the isotope ( 125 I or 131 I) and size of the labeled protein had no influence on the magnitude of delay. Whole-body radiation curves of animals that received [ 125 I]iodotyrosines, Na 131 I, or 131 I-polyvinylpyrrolidone exhibited no initial delays. These results do not support the earlier notion that delay is caused by a redistribution of the labeled protein in the body to radiometrically more favorable sites. However, they are compatible with the assumption that delayed passage of a protein dose through the extracellular matrix and/or retarded transfer of proteolytic products from extravascular catabolic sites to plasma may be responsible for the phenomenon

  19. Hydrogen peroxide-induced reduction of delayed rectifier potassium current in hippocampal neurons involves oxidation of sulfhydryl groups.

    Science.gov (United States)

    Hasan, Sonia M K; Redzic, Zoran B; Alshuaib, Waleed B

    2013-07-03

    This study examined the effect of H2O2 on the delayed rectifier potassium current (IKDR) in isolated hippocampal neurons. Whole-cell voltage-clamp experiments were performed on freshly dissociated hippocampal CA1 neurons of SD rats before and after treatment with H2O2. To reveal the mechanism behind H2O2-induced changes in IKDR, cells were treated with different oxidizing and reducing agents. External application of membrane permeable H2O2 reduced the amplitude and voltage-dependence of IKDR in a concentration dependent manner. Desferoxamine (DFO), an iron-chelator that prevents hydroxyl radical (OH) generation, prevented H2O2-induced reduction in IKDR. Application of the sulfhydryl-oxidizing agent 5,5 dithio-bis-nitrobenzoic acid (DTNB) mimicked the effect of H2O2. Sulfhydryl-reducing agents dithiothreitol (DTT) and glutathione (GSH) alone did not affect IKDR; however, DTT and GSH reversed and prevented the H2O2-induced inhibition of IKDR, respectively. Membrane impermeable agents GSH and DTNB showed effects only when added intracellularly identifying intracellular sulfhydryl groups as potential targets for hydroxyl-mediated oxidation. However, the inhibitory effects of DTNB and H2O2 at the positive test potentials were completely and partially abolished by DTT, respectively, suggesting an additional mechanism of action for H2O2, that is not shared by DTNB. In summary, this study provides evidence for the redox modulation of IKDR, identifies hydroxyl radical as an intermediate oxidant responsible for the H2O2-induced decrease in current amplitude and identifies intracellular sulfhydryl groups as an oxidative target. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Impulsive control of time-delay systems using delayed impulse and its application to impulsive master-slave synchronization

    International Nuclear Information System (INIS)

    Sun Jitao; Han Qinglong; Jiang Xiefu

    2008-01-01

    This Letter is concerned with impulsive control of a class of nonlinear time-delay systems. Some uniform stability criteria for the closed-loop time-delay system under delayed impulsive control are derived by using piecewise Lyapunov functions. Then the criteria are applied to impulsive master-slave synchronization of some secure communication systems with transmission delays and sample delays under delayed impulsive control. Two numerical examples are given to illustrate the effectiveness of the derived results

  1. Prehospital delay in acute coronary syndrome--an analysis of the components of delay

    DEFF Research Database (Denmark)

    Ottesen, Michael Mundt; Dixen, Ulrik; Torp-Pedersen, Christian

    2004-01-01

    BACKGROUND: Prompt hospital admission is essential when treating acute coronary syndrome. Delay prior to admission is unnecessarily long. Therefore, a thorough scrutiny of the influence of characteristics, circumstantial and subjective variables on elements of prehospital delay among patients...... admitted with acute coronary syndrome is warranted. METHODS: A structured interview was conducted on 250 consecutive patients admitted alive with acute coronary syndrome. RESULTS: Median prehospital, decision, physician and transportation delays were 107, 74, 25 and 22 min, respectively. Women (n=77) had...... of acute coronary syndrome among women, and thereby contributes to unnecessary long delay to treatment. The patient's prior experience and interpretation has a significant influence on behaviour....

  2. Communication key using delay times in time-delayed chaos synchronization

    International Nuclear Information System (INIS)

    Kim, Chil-Min; Kye, Won-Ho; Rim, Sunghwan; Lee, Soo-Young

    2004-01-01

    We propose an efficient key scheme, which can generate a great number of communication keys, for communication using chaos synchronization. We have attained the keys from delay times of time-delay coupled chaotic systems. We explain the scheme and the efficiency by coupling Henon and logistic maps and illustrate them by coupling Navier-Stokes and Lorenz equations as a continuous system

  3. External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation.

    Science.gov (United States)

    Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

    2017-10-01

    The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation.Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups.The mean follow-up time was 18.6 months (range: 5-24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P  .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P  0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05).External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation.

  4. Steeper discounting of delayed rewards in schizophrenia but not first-degree relatives.

    Science.gov (United States)

    Yu, Linda Q; Lee, Sangil; Katchmar, Natalie; Satterthwaite, Theodore D; Kable, Joseph W; Wolf, Daniel H

    2017-06-01

    Excessive discounting of future rewards has been related to a variety of risky behaviors and adverse clinical conditions. Prior work examining delay discounting in schizophrenia suggests an elevated discount rate. However, it remains uncertain whether this reflects the disease process itself or an underlying genetic vulnerability, whether it is selective for delay discounting or reflects pervasive changes in decision-making, and whether it is driven by specific clinical dimensions such as cognitive impairment. Here we investigated delay discounting, as well as loss aversion and risk aversion, in three groups: schizophrenia (SZ), unaffected first-degree family members (FM), and controls without a family history of psychosis (NC). SZ had elevated discounting, without changes in loss aversion or risk aversion. Contrary to expectations, the FM group did not show an intermediate phenotype in discounting. Higher discount rates correlated with lower cognitive performance on verbal reasoning, but this did not explain elevated discount rates in SZ. Group differences were driven primarily by the non-smoking majority of the sample. This study provides further evidence for elevated discounting in schizophrenia, and demonstrates that steeper discounting is not necessarily associated with familial risk, cannot be wholly accounted for by cognitive deficits, and is not attributable to smoking-related impulsivity. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  5. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  6. Limited value of delayed radiothallium image in the diagnosis of nodular goiter

    International Nuclear Information System (INIS)

    Misaki, Takashi; Yagi, Kanji; Dokoh, Shigeharu; Koh, Toshikiyo; Shimbo, Shin-ichiro

    1991-01-01

    To test whether delayed thallium image can improve the diagnostic accuracy of thyroid tumor, we have reviewed 35 patients with cold nodules of proven histopathology. Early and delayed images were taken 10-20 min and 3-4 hr postinjection, respectively. In this study, a thyroid nodule was interpreted as malignant if it had normal or increased uptake on early scan and more residual radioactivity than paranodular tissue on delayed scan. In the eighteen patients who had carcinoma, a disappointing 44% false negative rate was observed. No significant difference was seen between retention-positive and negative cases in tumor size or histological type of cancer. Nor could any demographic bias explain the low sensitivity. Of the six false negatives, macroscopic cystic degeneration was seen in two cases, but tumors in the other four were grossly solid. Considering the histological heterogeneity often seen within a thyroid tumor, the portion with increased retention of radiothallium may be too small to be detected in the false negative cases. Furthermore, 3 false positive readings were obtained in 17 patients with benign conditions. We conclude that the contribution of the delayed thallium image was quite limited in predicting or ruling out malignancy in nodular goiters. (author)

  7. Cell cycle delays in synchronized cell populations following irradiation with heavy ions

    International Nuclear Information System (INIS)

    Scholz, M.

    1992-11-01

    Mammalian cells subjected to irradiation with heavy ions were investigated for cell cycle delays. The ions used for this purpose included Ne ions in the LET range of 400 keV/μm just as well as uranium ions of 16225 keV/μm. The qualitative changes in cell cycle progression seen after irradiation with Ne ions (400 keV/μm) were similar to those observed in connection with X-rays. Following irradiation with extremely heavy ions (lead, uranium) the majority of cells were even at 45 hours still found to be in the S phase or G 2 M phase of the first cycle. The delay cross section 'σ-delay' was introduced as a quantity that would permit quantitative comparisons to be carried out between the changes in cell progression and other effects of radiation. In order to evaluate the influence of the number of hits on the radiation effect observed, the size of the cell nucleus was precisely determined with reference to the cycle phase and local cell density. A model to simulate those delay effects was designed in such a way that account is taken of this probability of hit and that the results can be extrapolated from the delay effects after X-irradiation. On the basis of the various probabilities of hit for cells at different cycle stages a model was developed to ascertain the intensified effect following fractionated irradiation with heavy ions. (orig./MG) [de

  8. Sample size determinations for group-based randomized clinical trials with different levels of data hierarchy between experimental and control arms.

    Science.gov (United States)

    Heo, Moonseong; Litwin, Alain H; Blackstock, Oni; Kim, Namhee; Arnsten, Julia H

    2017-02-01

    We derived sample size formulae for detecting main effects in group-based randomized clinical trials with different levels of data hierarchy between experimental and control arms. Such designs are necessary when experimental interventions need to be administered to groups of subjects whereas control conditions need to be administered to individual subjects. This type of trial, often referred to as a partially nested or partially clustered design, has been implemented for management of chronic diseases such as diabetes and is beginning to emerge more commonly in wider clinical settings. Depending on the research setting, the level of hierarchy of data structure for the experimental arm can be three or two, whereas that for the control arm is two or one. Such different levels of data hierarchy assume correlation structures of outcomes that are different between arms, regardless of whether research settings require two or three level data structure for the experimental arm. Therefore, the different correlations should be taken into account for statistical modeling and for sample size determinations. To this end, we considered mixed-effects linear models with different correlation structures between experimental and control arms to theoretically derive and empirically validate the sample size formulae with simulation studies.

  9. Luteal cell steroidogenesis in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Meenakumari, Karukayil J; Banerjee, Arnab; Krishna, Amitabh

    2009-01-01

    The primary aim of this study was to determine the possible cause of slow or delayed embryonic development in Cynopterus sphinx by investigating morphological and steroidogenic changes in the corpus luteum (CL) and circulating hormone concentrations during two pregnancies of a year. This species showed delayed post-implantational embryonic development during gastrulation of the first pregnancy. Morphological features of the CL showed normal luteinization during both pregnancies. The CL did not change significantly in luteal cell size during the delay period of the first pregnancy as compared with the second pregnancy. The circulating progesterone and 17beta-estradiol concentrations were significantly lower during the period of delayed embryonic development as compared with the same stage of embryonic development during the second pregnancy. We also showed a marked decline in the activity of 3beta-hydroxysteroid dehydrogenase, P450 side chain cleavage enzyme, and steroidogenic acute regulatory peptide in the CL during the delay period. This may cause low circulating progesterone and estradiol synthesis and consequently delay embryonic development. What causes the decrease in steroidogenic factors in the CL during the period of delayed development in C. sphinx is under investigation.

  10. Improving Delay-Range-Dependent Stability Condition for Systems with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Wei Qian

    2013-01-01

    Full Text Available This paper discusses the delay-range-dependent stability for systems with interval time-varying delay. Through defining the new Lyapunov-Krasovskii functional and estimating the derivative of the LKF by introducing new vectors, using free matrices and reciprocally convex approach, the new delay-range-dependent stability conditions are obtained. Two well-known examples are given to illustrate the less conservatism of the proposed theoretical results.

  11. Social Class and Group Size as Predictors of Behavior in Male Equus kiang

    Directory of Open Access Journals (Sweden)

    Prameek M. Kannan

    2017-11-01

    Full Text Available Ethograms provide a systematic approach to identify and quantify the repertoire of behaviors of an organism. This information may assist animal welfare in zoos, increase awareness of conservation needs, and help curb high-risk behaviors during human-wildlife conflict. Our primary objective was to utilize an equid ethogram to produce activity budgets for Equus kiang males, a social ungulate that is among the least-studied mammals worldwide, and unknown to the ethological literature. We recently reported the existence of three social classes of this species; Territorial males, Bachelor males and ‘Transient’ males. Therefore, our secondary objective was to compare activity budgets in each of these three groups. We found that kiang spent >70% of their time performing six behaviors: vigilance (34%, locomotion (24.2%, resting (14.2%, mixed foraging (12.5%, browsing (5.1%, and antagonism (1.1%. Over 2% of the total behavioral investment was spent on olfactory investigations (genital sniffing, sniffing proximity and flehmen. Eleven of the eighteen behaviors differed by class. Habitat selection differed strongly by each group, with Territorial males favoring mesic sites with greater vegetation abundance. Vigilance also differed according to habitat selection, but not group size. Animals in the xeric, least vegetation-rich area were far less vigilant than animals at more attractive sites. We found that the full repertoire of behaviors, and relative investments in each, differ according to social class. These findings are a reminder that researchers should make every effort to disambiguate social class among ungulates– and other taxa where behaviors are class-dependent.

  12. Treatment delay of bone tumours, compilation of a sociodemographic risk profile: A retrospective study

    International Nuclear Information System (INIS)

    Schnurr, Christoph; Pippan, Mathias; Stuetzer, Hartmut; Delank, Karl S; Michael, Joern WP; Eysel, Peer

    2008-01-01

    Bone tumours are comparatively rare tumours and delays in diagnosis and treatment are common. The purpose of this study was to analyse sociodemographic risk factors for bone tumour patients in order to identify those at risk of prolonged patients delay (time span from first symptoms to consultation), professional delay (from consultation to treatment) or symptom interval (from first symptoms to treatment). Understanding these relationships might enable us to shorten time to diagnosis and therapy. We carried out a retrospective analysis of 265 patients with bone tumours documenting sociodemographic factors, patient delay, professional delay and symptom interval. A multivariate explorative Cox model was performed for each delay. Female gender was associated with a prolonged patient delay. Age under 30 years and rural living predisposes to a prolonged professional delay and symptom interval. Early diagnosis and prompt treatment are required for successful management of most bone tumour patients. We succeeded in identifying the histology independent risk factors of age under 30 years and rural habitation for treatment delay in bone tumour patients. Knowing about the existence of these risk groups age under 30 years and female gender could help the physician to diagnose bone tumours earlier. The causes for the treatment delays of patients living in a rural area have to be investigated further. If the delay initiates in the lower education of rural general physicians, further training about bone tumours might advance early detection. Hence the outcome of patients with bone tumours could be improved

  13. Modeling of delays in PKPD: classical approaches and a tutorial for delay differential equations.

    Science.gov (United States)

    Koch, Gilbert; Krzyzanski, Wojciech; Pérez-Ruixo, Juan Jose; Schropp, Johannes

    2014-08-01

    In pharmacokinetics/pharmacodynamics (PKPD) the measured response is often delayed relative to drug administration, individuals in a population have a certain lifespan until they maturate or the change of biomarkers does not immediately affects the primary endpoint. The classical approach in PKPD is to apply transit compartment models (TCM) based on ordinary differential equations to handle such delays. However, an alternative approach to deal with delays are delay differential equations (DDE). DDEs feature additional flexibility and properties, realize more complex dynamics and can complementary be used together with TCMs. We introduce several delay based PKPD models and investigate mathematical properties of general DDE based models, which serve as subunits in order to build larger PKPD models. Finally, we review current PKPD software with respect to the implementation of DDEs for PKPD analysis.

  14. A delay fractioning approach to global synchronization of delayed complex networks with stochastic disturbances

    International Nuclear Information System (INIS)

    Wang Yao; Wang Zidong; Liang Jinling

    2008-01-01

    In this Letter, the synchronization problem is investigated for a class of stochastic complex networks with time delays. By utilizing a new Lyapunov functional form based on the idea of 'delay fractioning', we employ the stochastic analysis techniques and the properties of Kronecker product to establish delay-dependent synchronization criteria that guarantee the globally asymptotically mean-square synchronization of the addressed delayed networks with stochastic disturbances. These sufficient conditions, which are formulated in terms of linear matrix inequalities (LMIs), can be solved efficiently by the LMI toolbox in Matlab. The main results are proved to be much less conservative and the conservatism could be reduced further as the number of delay fractioning gets bigger. A simulation example is exploited to demonstrate the advantage and applicability of the proposed result

  15. A distributed delay approach for modeling delayed outcomes in pharmacokinetics and pharmacodynamics studies.

    Science.gov (United States)

    Hu, Shuhua; Dunlavey, Michael; Guzy, Serge; Teuscher, Nathan

    2018-04-01

    A distributed delay approach was proposed in this paper to model delayed outcomes in pharmacokinetics and pharmacodynamics studies. This approach was shown to be general enough to incorporate a wide array of pharmacokinetic and pharmacodynamic models as special cases including transit compartment models, effect compartment models, typical absorption models (either zero-order or first-order absorption), and a number of atypical (or irregular) absorption models (e.g., parallel first-order, mixed first-order and zero-order, inverse Gaussian, and Weibull absorption models). Real-life examples were given to demonstrate how to implement distributed delays in Phoenix ® NLME™ 8.0, and to numerically show the advantages of the distributed delay approach over the traditional methods.

  16. Novel delay-distribution-dependent stability analysis for continuous-time recurrent neural networks with stochastic delay

    International Nuclear Information System (INIS)

    Wang Shen-Quan; Feng Jian; Zhao Qing

    2012-01-01

    In this paper, the problem of delay-distribution-dependent stability is investigated for continuous-time recurrent neural networks (CRNNs) with stochastic delay. Different from the common assumptions on time delays, it is assumed that the probability distribution of the delay taking values in some intervals is known a priori. By making full use of the information concerning the probability distribution of the delay and by using a tighter bounding technique (the reciprocally convex combination method), less conservative asymptotic mean-square stable sufficient conditions are derived in terms of linear matrix inequalities (LMIs). Two numerical examples show that our results are better than the existing ones. (general)

  17. Split and delay photon correlation spectroscopy with a visible light

    International Nuclear Information System (INIS)

    Rasch, Marten

    2016-04-01

    The development and performance of a setup constructed with the aim for the split pulse photon correlation spectroscopy is presented in this thesis. The double pulse time structure is accomplished with help of an Acusto-Optic Modulator (AOM) crystal, which mimics the splitting and delaying of photon pulses. The setup provides double pulses and allows to control the pulse width and delay and to synchronize them into one camera exposure window. The performance of the setup was successfully verified in a proof of principle experiment with a model system of polystyrene particles following Brownian motion. The measured radius of particles obtained with from the split pulse experiment (R h =(2.567±0.097) μm) is in agreement with the particle size provided by the manufacturer (R=(2.26±0.08) μm). The achieved results show higher statistics compared to a standard Dynamic Light Scattering (DLS) measurement.

  18. The oxidative costs of reproduction are group-size dependent in a wild cooperative breeder.

    Science.gov (United States)

    Cram, Dominic L; Blount, Jonathan D; Young, Andrew J

    2015-11-22

    Life-history theory assumes that reproduction entails a cost, and research on cooperatively breeding societies suggests that the cooperative sharing of workloads can reduce this cost. However, the physiological mechanisms that underpin both the costs of reproduction and the benefits of cooperation remain poorly understood. It has been hypothesized that reproductive costs may arise in part from oxidative stress, as reproductive investment may elevate exposure to reactive oxygen species, compromising survival and future reproduction and accelerating senescence. However, experimental evidence of oxidative costs of reproduction in the wild remains scarce. Here, we use a clutch-removal experiment to investigate the oxidative costs of reproduction in a wild cooperatively breeding bird, the white-browed sparrow weaver, Plocepasser mahali. Our results reveal costs of reproduction that are dependent on group size: relative to individuals in groups whose eggs were experimentally removed, individuals in groups that raised offspring experienced an associated cost (elevated oxidative damage and reduced body mass), but only if they were in small groups containing fewer or no helpers. Furthermore, during nestling provisioning, individuals that provisioned at higher rates showed greater within-individual declines in body mass and antioxidant protection. Our results provide rare experimental evidence that reproduction can negatively impact both oxidative status and body mass in the wild, and suggest that these costs can be mitigated in cooperative societies by the presence of additional helpers. These findings have implications for our understanding of the energetic and oxidative costs of reproduction, and the benefits of cooperation in animal societies. © 2015 The Authors.

  19. Surgery for hip fractures: Does surgical delay affect outcomes?

    Directory of Open Access Journals (Sweden)

    Nicole Simunovic

    2011-01-01

    Full Text Available Hip fractures are associated with a high rate of mortality and profound temporary and sometimes permanent impairment of quality of life. Current guidelines indicate that surgeons should perform surgery for a hip fracture within 24 hours of injury because earlier surgery is associated with better functional outcome and lower rates of perioperative complications and mortality. Proponents of early treatment argue that this approach minimizes the length of time a patient is confined to bed rest, thereby reducing the risk for associated complications, such as pressure sores, deep vein thrombosis, and urinary tract infections. Those favoring delaying surgery beyond the guideline recommendations believe that this approach is required to medically optimize patients, and therefore decrease the risk for perioperative complications. Further challenges to resolving this debate is the lack of an accepted definition of what should constitute an "unacceptable delay" for hip fracture surgery and the fact that outcomes associated with surgical delay are based on observational data alone (i.e., not randomized controlled trials. The effect of preoperative timing on mortality and other patient-important outcomes across various age groups remains controversial and warrants a large randomized controlled trial to offer clear insights into the effects associated with early versus delayed surgery among hip fracture patients.

  20. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  1. Throughput and delay analysis of IEEE 802.15.6-based CSMA/CA protocol.

    Science.gov (United States)

    Ullah, Sana; Chen, Min; Kwak, Kyung Sup

    2012-12-01

    The IEEE 802.15.6 is a new communication standard on Wireless Body Area Network (WBAN) that focuses on a variety of medical, Consumer Electronics (CE) and entertainment applications. In this paper, the throughput and delay performance of the IEEE 802.15.6 is presented. Numerical formulas are derived to determine the maximum throughput and minimum delay limits of the IEEE 802.15.6 for an ideal channel with no transmission errors. These limits are derived for different frequency bands and data rates. Our analysis is validated by extensive simulations using a custom C+ + simulator. Based on analytical and simulation results, useful conclusions are derived for network provisioning and packet size optimization for different applications.

  2. Delay-Dependent Guaranteed Cost Control of an Interval System with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Xiao Min

    2009-01-01

    Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.

  3. Delay-Dependent Control for Networked Control Systems with Large Delays

    Directory of Open Access Journals (Sweden)

    Yilin Wang

    2013-01-01

    Full Text Available We consider the problems of robust stability and control for a class of networked control systems with long-time delays. Firstly, a nonlinear discrete time model with mode-dependent time delays is proposed by converting the uncertainty of time delay into the uncertainty of parameter matrices. We consider a probabilistic case where the system is switched among different subsystems, and the probability of each subsystem being active is defined as its occurrence probability. For a switched system with a known subsystem occurrence probabilities, we give a stochastic stability criterion in terms of linear matrix inequalities (LMIs. Then, we extend the results to a more practical case where the subsystem occurrence probabilities are uncertain. Finally, a simulation example is presented to show the efficacy of the proposed method.

  4. Quad nanosecond delay module

    International Nuclear Information System (INIS)

    McDonald, R.J.; Hunter, J.B.; Wozniak, G.J.

    1986-04-01

    Four nanosecond (ns) delay units have been designed to fit in a single-width NIM module. This module is particularly suited for use in conjunction with quad constant fraction timing discriminators (CFTDs) since it has four delay units that can be placed adjacent to the four units of the CFTD. A series of different length cables connected via DIP toggle switches provide delays of 0.60 ns in 4 ns increments. Thus, the CFTD delay can be optimized for pulses of different rise times from approx.10-100 ns. Design work for the PC board and silkscreening of the front panel were done with the MacDraw program on the Apple Mackintosh computer and printed with the Lasewriter printer. 6 refs

  5. Optically-derived estimates of phytoplankton size class and taxonomic group biomass in the Eastern Subarctic Pacific Ocean

    Science.gov (United States)

    Zeng, Chen; Rosengard, Sarah Z.; Burt, William; Peña, M. Angelica; Nemcek, Nina; Zeng, Tao; Arrigo, Kevin R.; Tortell, Philippe D.

    2018-06-01

    We evaluate several algorithms for the estimation of phytoplankton size class (PSC) and functional type (PFT) biomass from ship-based optical measurements in the Subarctic Northeast Pacific Ocean. Using underway measurements of particulate absorption and backscatter in surface waters, we derived estimates of PSC/PFT based on chlorophyll-a concentrations (Chl-a), particulate absorption spectra and the wavelength dependence of particulate backscatter. Optically-derived [Chl-a] and phytoplankton absorption measurements were validated against discrete calibration samples, while the derived PSC/PFT estimates were validated using size-fractionated Chl-a measurements and HPLC analysis of diagnostic photosynthetic pigments (DPA). Our results showflo that PSC/PFT algorithms based on [Chl-a] and particulate absorption spectra performed significantly better than the backscatter slope approach. These two more successful algorithms yielded estimates of phytoplankton size classes that agreed well with HPLC-derived DPA estimates (RMSE = 12.9%, and 16.6%, respectively) across a range of hydrographic and productivity regimes. Moreover, the [Chl-a] algorithm produced PSC estimates that agreed well with size-fractionated [Chl-a] measurements, and estimates of the biomass of specific phytoplankton groups that were consistent with values derived from HPLC. Based on these results, we suggest that simple [Chl-a] measurements should be more fully exploited to improve the classification of phytoplankton assemblages in the Northeast Pacific Ocean.

  6. Application of a Lie group admitted by a homogeneous equation for group classification of a corresponding inhomogeneous equation

    Science.gov (United States)

    Long, Feng-Shan; Karnbanjong, Adisak; Suriyawichitseranee, Amornrat; Grigoriev, Yurii N.; Meleshko, Sergey V.

    2017-07-01

    This paper proposes an algorithm for group classification of a nonhomogeneous equation using the group analysis provided for the corresponding homogeneous equation. The approach is illustrated by a partial differential equation, an integro-differential equation, and a delay partial differential equation.

  7. Small-Size High-Current Generators for X-Ray Backlighting

    Science.gov (United States)

    Chaikovsky, S. A.; Artyomov, A. P.; Zharova, N. V.; Zhigalin, A. S.; Lavrinovich, I. V.; Oreshkin, V. I.; Ratakhin, N. A.; Rousskikh, A. G.; Fedunin, A. V.; Fedushchak, V. F.; Erfort, A. A.

    2017-12-01

    The paper deals with the soft X-ray backlighting based on the X-pinch as a powerful tool for physical studies of fast processes. Proposed are the unique small-size pulsed power generators operating as a low-inductance capacitor bank. These pulse generators provide the X-pinch-based soft X-ray source (hν = 1-10 keV) of micron size at 2-3 ns pulse duration. The small size and weight of pulse generators allow them to be transported to any laboratory for conducting X-ray backlighting of test objects with micron space resolution and nanosecond exposure time. These generators also allow creating synchronized multi-frame radiographic complexes with frame delay variation in a broad range.

  8. Early Versus Delayed Passive Range of Motion After Rotator Cuff Repair: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Kluczynski, Melissa A; Nayyar, Samir; Marzo, John M; Bisson, Leslie J

    2015-08-01

    Postoperative rehabilitation has been shown to affect healing of the rotator cuff after surgical repair. However, it is unknown whether an early or delayed rehabilitation protocol is most beneficial for healing. To determine whether early versus delayed passive range of motion (PROM) affects rotator cuff (RC) retear rates after surgery. Systematic review and meta-analysis. A systematic review of the literature published between January 2003 and February 2014 was conducted. Retear rates were compared for early (within 1 week after surgery) versus delayed (3-6 weeks after surgery) PROM using χ(2) or Fisher exact tests as well as relative risks (RR) and 95% CIs. In the first analysis, data from evidence level 1 studies that directly compared early versus delayed PROM were pooled; and in the second analysis, data from level 1 to 4 studies that did not directly compare early versus delayed PROM were pooled. The second analysis was stratified by tear size and repair method. Twenty-eight studies (1729 repairs) were included. The first analysis of level 1 studies did not reveal a significant difference in retear rates for early (13.7%) versus delayed (10.5%) PROM (P = .36; RR = 1.30 [95% CI, 0.74-2.30]). The second analysis revealed that for ≤3 cm tears, the risk of retear was lower for early versus delayed PROM for transosseous (TO) plus single-row anchor (SA) repairs (18.7% vs 28.2%, P = .02; RR = 0.66 [95% CI, 0.47-0.95]). For >5 cm tears, the risk of retear was greater for early versus delayed PROM for double-row anchor (DA) repairs (56.4% vs 20%, P = .002; RR = 2.82 [95% CI, 1.31-6.07]) and for all repair methods combined (52.2% vs 22.6%, P = .01; RR = 2.31 [95% CI, 1.16-4.61]). There were no statistically significant associations for tears measuring 3 cm. Evidence is lacking with regard to the optimal timing of PROM after RC repair; however, this study suggests that tear size may be influential. © 2014 The Author(s).

  9. UAVs and Control Delays

    National Research Council Canada - National Science Library

    de Vries, S. C

    2005-01-01

    .... Delays of about 250-300 ms often lead to unacceptable airplane handling qualities. Techniques such as filtering and predictive displays may extend the range of acceptable delays up to about 400 ms...

  10. Scintigraphic evaluation of coronary thrombolysis with urokinase using /sup 201/Tl-emission computed tomography. Effect on infarct size

    Energy Technology Data Exchange (ETDEWEB)

    Kambara, Hirofumi; Tamaki, Shunichi; Kadota, Kazunori; Nohara, Takashi; Suzuki, Yukisono; Tamaki, Nagara; Torizuka, Kanji; Kawai, Chuichi [Kyoto Univ. (Japan). Faculty of Medicine

    1984-09-01

    Twenty-seven patients with first acute myocardial infarction were evaluated by serial determination of creatine kinase (CK) and thallium-201 myocardial emission computed tomography (ECT) performed four weeks after infarction. Total release of CK-MB and peak CK-MB had a linear correlation with infarct volume calculated by ECT, but a different relationship was found in between patients with successful coronary thrombolysis and those without. The former group of patients had an earlier peak of CK-MB and larger release of the cardiac enzyme comparative to infarct volume than the latter group. In 28 cases with proximal occlusion of the anterior descending coronary artery ECT-infarct volume was smaller with ealier recanalization within 10 hours after onset of infarction and, therefore, the time delay of recanalization may be allowed up to 10 hours. In conclusion, early coronary recanalization is an effective method to limit infarct size and time limit may be up to 10 hours after onset of infarction. But enzymatic calculation of infarct size should be modified when early coronary recanalization was expected.

  11. Analytical applications for delayed neutrons

    International Nuclear Information System (INIS)

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes

  12. Grain size statistics and depositional pattern of the Ecca Group sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    Baiyegunhi Christopher

    2017-11-01

    Full Text Available Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicate the dominance of low energy environment. The bivariate plots show that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are lacustrine or deltaic deposits. The C-M plots indicated that the sediments were deposited mainly by suspension and saltation, and graded suspension. Visher diagrams show that saltation is the major process of transportation, followed by suspension.

  13. Grain size statistics and depositional pattern of the Ecca Group sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa

    Science.gov (United States)

    Baiyegunhi, Christopher; Liu, Kuiwu; Gwavava, Oswald

    2017-11-01

    Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicate the dominance of low energy environment. The bivariate plots show that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are lacustrine or deltaic deposits. The C-M plots indicated that the sediments were deposited mainly by suspension and saltation, and graded suspension. Visher diagrams show that saltation is the major process of transportation, followed by suspension.

  14. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  15. Impact of fluoroquinolone treatment on delay of tuberculosis diagnosis: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Catherine A Hogan

    2017-01-01

    Full Text Available Background: Fluoroquinolones are among the most commonly used antibiotics for the treatment of respiratory infections. Because fluoroquinolones show bactericidal activity against Mycobacterium tuberculosis, there is concern that their use can delay the diagnosis of tuberculosis. We conducted a systematic review and meta-analysis to assess whether empiric treatment with fluoroquinolones delays the diagnosis and treatment of tuberculosis in patients with respiratory tract infections. Objectives: The primary objective was to assess the delay in days in the diagnosis and treatment of tuberculosis, among patients who received quinolones, compared to those who received non-fluoroquinolone antibiotics. Methods: We included studies of adult patients treated with fluoroquinolones prior to a confirmed diagnosis of tuberculosis. We performed a literature search of 7 databases (including PubMed, Embase and Cochrane Library with no language restrictions. We calculated an unweighted mean of estimate of difference in delay across all studies. For the studies for which the estimate was available as a mean with standard deviation, a weighted average using a random effects meta-analysis model was estimated. Results: A total of 3983 citations were identified from the literature search; of these, 17 articles were selected for full-text review. A total of 10 studies were retained for the synthesis. These included 7 retrospective cohort studies and 3 case-control studies. Only one of these studies was from a high TB burden country, South Africa. The most commonly used fluoroquinolones were levofloxacin, gemifloxacin and moxifloxacin. The unweighted average of difference in delay between the fluoroquinolone group and non-fluoroquinolone group was 12.9 days (95% CI 6.1–19.7. When these differences were pooled using a random effects model, the weighted estimate was 10.9 days (95% CI 4.2–17.6. When stratified by acid-fast smear status, the delay was

  16. Delayed puberty in boys

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007695.htm Delayed puberty in boys To use the sharing features on this page, please enable JavaScript. Delayed puberty in boys is when puberty does not begin ...

  17. Delay-range-dependent exponential H∞ synchronization of a class of delayed neural networks

    International Nuclear Information System (INIS)

    Karimi, Hamid Reza; Maass, Peter

    2009-01-01

    This article aims to present a multiple delayed state-feedback control design for exponential H ∞ synchronization problem of a class of delayed neural networks with multiple time-varying discrete delays. On the basis of the drive-response concept and by introducing a descriptor technique and using Lyapunov-Krasovskii functional, new delay-range-dependent sufficient conditions for exponential H ∞ synchronization of the drive-response structure of neural networks are driven in terms of linear matrix inequalities (LMIs). The explicit expression of the controller gain matrices are parameterized based on the solvability conditions such that the drive system and the response system can be exponentially synchronized. A numerical example is included to illustrate the applicability of the proposed design method.

  18. A pilot study to investigate the effect of a hydration regime upon immediate and 24 h delayed MRI contrast agent reactions

    International Nuclear Information System (INIS)

    Bailey, William; Marshall, Gill; Coals, Jacqui

    2007-01-01

    Purpose: Adverse reaction rates to gadolinium based magnetic resonance imaging (MRI) contrast agents which occur immediately post-injection are well documented. However little research has investigated delayed reaction rates (i.e. 30 min-24 h). This study evaluated the rate of immediate and delayed adverse reaction rates to a gadolinium based MRI contrast agent (Dotarem) and investigated the effect of a hydration regime on the rate of adverse events. Method: Fifty-eight patients received no preparation, prior to administration of the contrast agent, whilst another 58 underwent a hydration protocol. The patients had their answers to a questionnaire recorded immediately after the scanning procedure and also via a follow-up telephone call 24 h later. Results: In the unprepared group 9 patients (15.5%) experienced immediate adverse events, i.e. within 0-30 min, whereas 24 (41.4%) experienced delayed reactions (30 min-24 h) after administration of the contrast agent. In the hydrated patient group 6 (10.3%) experienced an immediate adverse event, whilst 8 (13.7%) experienced delayed events post-injection. The difference in the total reaction rates for the unprepared and hydrated groups was statistically significant for immediate and delayed reactions. The difference in the rates of delayed headache, nausea, dizziness and problems with the injection site, for the unprepared and hydrated groups was statistically significant. Conclusion: An oral hydration regime administered to patients, both before and after MRI contrast agent administration significantly reduced the total number of immediate and delayed reactions. It also significantly reduced delayed headache, nausea, dizziness and problems at the injection site. Whilst this pilot study had methodological shortcomings, the strength of the relationship demonstrated are worthy of further investigation

  19. New Results on Passivity Analysis of Stochastic Neural Networks with Time-Varying Delay and Leakage Delay

    Directory of Open Access Journals (Sweden)

    YaJun Li

    2015-01-01

    Full Text Available The passivity problem for a class of stochastic neural networks systems (SNNs with varying delay and leakage delay has been further studied in this paper. By constructing a more effective Lyapunov functional, employing the free-weighting matrix approach, and combining with integral inequality technic and stochastic analysis theory, the delay-dependent conditions have been proposed such that SNNs are asymptotically stable with guaranteed performance. The time-varying delay is divided into several subintervals and two adjustable parameters are introduced; more information about time delay is utilised and less conservative results have been obtained. Examples are provided to illustrate the less conservatism of the proposed method and simulations are given to show the impact of leakage delay on stability of SNNs.

  20. Effect of delayed diagnosis on disease course and management of Churg-Strauss syndrome: a retrospective study.

    Science.gov (United States)

    Sokołowska, Barbara; Szczeklik, Wojciech; Mastalerz, Lucyna; Kuczia, Paweł; Wodkowski, Michał; Stodółkiewicz, Edyta; Macioł, Karolina; Musiał, Jacek

    2013-03-01

    Delayed diagnosis in patients with Churg-Strauss syndrome (CSS) is largely attributed to the variable and nonspecific presentation of the disease's initial symptoms. The aim of the study was to evaluate the effect of delayed diagnosis on the course of CSS. We conducted a retrospective study of 30 CSS patients followed up in our department. In each patient, we assessed the delay in CSS diagnosis (the time when patients already fulfilled four out of six of the American College of Rheumatology criteria and the diagnosis was not yet established), the disease activity at the time of diagnosis, and organ involvement during CSS course. A median value of 2 weeks was chosen as the cutoff point after which the diagnosis was considered as delayed. Sixteen patients were diagnosed before (group 1) and 14 patients after this cutoff point (group 2). In group 2, we found a higher Birmingham Vasculitis Activity Score at the moment of diagnosis (20.4 vs 25.1, p < 0.05) and a more severe disease course, resulting in more frequent hospitalization rates (0.64 vs 2.26/year, p < 0.00001), higher corticosteroids dose requirements (5.87 vs 11.57 mg/day converted to methylprednisolone, p < 0.0001), and additional immunosuppressive therapy administration (56.2 vs 92.8 %, p < 0.05) to maintain disease remission. All six perinuclear pattern of antineutrophil cytoplasmic antibobodies (pANCA)-positive patients (20 %) were found in group 1. Concluding, the delay in diagnosis of CSS of more than 2 weeks was found to be associated with a disease course that was more severe. The presence of the pANCA antibodies may occasionally facilitate establishment of the diagnosis.

  1. Clinical Comparison of Outcomes of Early versus Delayed Carotid Artery Stenting for Symptomatic Cerebral Watershed Infarction due to Stenosis of the Proximal Internal Carotid Artery

    Directory of Open Access Journals (Sweden)

    Huakun Liu

    2016-01-01

    Full Text Available The aim of this study was to compare the clinical outcomes of early versus delayed carotid artery stenting (CAS for symptomatic cerebral watershed infarction (sCWI patients due to stenosis of the proximal internal carotid artery. We retrospectively collected clinical data of those who underwent early or delayed CAS from March 2011 to April 2014. The time of early CAS and delayed CAS was within a week of symptom onset and after four weeks from symptom onset. Clinical data such as second stroke, the National Institutes of Health Stroke Scale (NHISS score, and modified Rankin Scale (mRS score and periprocedural complications were collected. The rate of second stroke in early CAS group is lower when compared to that of delayed CAS group. There was no significant difference regarding periprocedural complications in both groups. There was a significant difference regarding mean NHISS score 90 days after CAS in two groups. Early CAS group had a significant better good outcome (mRS score ≤ 2 than delayed CAS group. We suggest early CAS for sCWI due to severe proximal internal carotid artery stenosis as it provides lower rate of second stroke, comparable periprocedural complications, and better functional outcomes compared to that of delayed CAS.

  2. Competition in size-structured populations: mechanisms inducing cohort formation and population cycles.

    Science.gov (United States)

    de Roos, André M; Persson, Lennart

    2003-02-01

    In this paper we investigate the consequences of size-dependent competition among the individuals of a consumer population by analyzing the dynamic properties of a physiologically structured population model. Only 2 size-classes of individuals are distinguished: juveniles and adults. Juveniles and adults both feed on one and the same resource and hence interact by means of exploitative competition. Juvenile individuals allocate all assimilated energy into development and mature on reaching a fixed developmental threshold. The combination of this fixed threshold and the resource-dependent developmental rate, implies that the juvenile delay between birth and the onset of reproduction may vary in time. Adult individuals allocate all assimilated energy to reproduction. Mortality of both juveniles and adults is assumed to be inversely proportional to the amount of energy assimilated. In this setting we study how the dynamics of the population are influenced by the relative foraging capabilities of juveniles and adults. In line with results that we previously obtained in size-structured consumer-resource models with pulsed reproduction, population cycles primarily occur when either juveniles or adults have a distinct competitive advantage. When adults have a larger per capita feeding rate and are hence competitively superior to juveniles, population oscillations occur that are primarily induced by the fact that the duration of the juvenile period changes with changing food conditions. These cycles do not occur when the juvenile delay is a fixed parameter. When juveniles are competitively superior, two different types of population fluctuations can occur: (1) rapid, low-amplitude fluctuations having a period of half the juvenile delay and (2) slow, large-amplitude fluctuations characterized by a period, which is roughly equal to the juvenile delay. The analysis of simplified versions of the structured model indicates that these two types of oscillations also occur if

  3. Identifying time-delayed gene regulatory networks via an evolvable hierarchical recurrent neural network.

    Science.gov (United States)

    Kordmahalleh, Mina Moradi; Sefidmazgi, Mohammad Gorji; Harrison, Scott H; Homaifar, Abdollah

    2017-01-01

    The modeling of genetic interactions within a cell is crucial for a basic understanding of physiology and for applied areas such as drug design. Interactions in gene regulatory networks (GRNs) include effects of transcription factors, repressors, small metabolites, and microRNA species. In addition, the effects of regulatory interactions are not always simultaneous, but can occur after a finite time delay, or as a combined outcome of simultaneous and time delayed interactions. Powerful biotechnologies have been rapidly and successfully measuring levels of genetic expression to illuminate different states of biological systems. This has led to an ensuing challenge to improve the identification of specific regulatory mechanisms through regulatory network reconstructions. Solutions to this challenge will ultimately help to spur forward efforts based on the usage of regulatory network reconstructions in systems biology applications. We have developed a hierarchical recurrent neural network (HRNN) that identifies time-delayed gene interactions using time-course data. A customized genetic algorithm (GA) was used to optimize hierarchical connectivity of regulatory genes and a target gene. The proposed design provides a non-fully connected network with the flexibility of using recurrent connections inside the network. These features and the non-linearity of the HRNN facilitate the process of identifying temporal patterns of a GRN. Our HRNN method was implemented with the Python language. It was first evaluated on simulated data representing linear and nonlinear time-delayed gene-gene interaction models across a range of network sizes and variances of noise. We then further demonstrated the capability of our method in reconstructing GRNs of the Saccharomyces cerevisiae synthetic network for in vivo benchmarking of reverse-engineering and modeling approaches (IRMA). We compared the performance of our method to TD-ARACNE, HCC-CLINDE, TSNI and ebdbNet across different network

  4. The comparing results of carcinoma between three-phase and delayed whole body bone scan

    International Nuclear Information System (INIS)

    Si Hongwei; Li Xianfeng

    2004-01-01

    Purpose: Three phase bone scan is an imaging technology in nuclear medicine, which composed of blood flow phase, blood pool phase and delayed phase and the last one is often performed in routine works in department of nuclear medicine. The purpose of this study is to evaluate the merit of three-phase bone scan.Methods: In this study, we chose 54 patients who were having an regional pain which caused by benign or malignant carcinoma that diagnosed by CT, X-ray, ECT, MRI or other examinations. The imaging were acquired simultaneously from both anterior and posterior views, after a bolus injection of 1110 MBq technetium-99m-labelled methylene diphosphonate (MDP), blood phase contains 20 frame sand 3 seconds per frame, blood pool phase contains 5 frames and 1 minute per frame, delayed phase was performed 2.5 hour later. According to the results of three-phase bone scan, the patients were divided into 2 groups: normal and abnormal groups. The abnormal group includes early phase positive,delay positive and all three phase positive sets. The comparing among the 3 sets were analyzed by chi-square test and other statistic means.Results: There were 54 patients who had suffered lung cancer, breast cancer and other cancer,involved in this study, 34 males and 20 females, ranged age 17 to 88 years, were normal in 15 cases,positive in 22 cases, the results in delayed phase were positive in 9 cases, blood flow and blood pool phase showed blood flow changes in 4 cases and soft tissue tumors were seen in 4 cases. Three phase bone scan was more sensitive than delayed whole body bone scan in detecting the abnormal sites (p 0.05) The sensitivity of detecting tumors in blood flow and blood pool phase,delayed phase were respectively lower than in three phase bone scan (p<0.001).Conclusion: It is more sensitivity of detecting tumor lesions in three phase bone scan than in delayed phase whole body bone scan and the changes of blood flow and soft tissue can be seen in three phase bone scan

  5. Delayed Hospital Discharges of Older Patients: A Systematic Review on Prevalence and Costs.

    Science.gov (United States)

    Landeiro, Filipa; Roberts, Kenny; Gray, Alastair Mcintosh; Leal, José

    2017-05-23

    To determine the prevalence of delayed discharges of elderly inpatients and associated costs. We searched Medline, Embase, Global Health, CAB Abstracts, Econlit, Web of Knowledge, EBSCO - CINAHL, The Cochrane Library, Health Management Information Consortium, and SCIE - Social Care Online for evidence published between 1990 and 2015 on number of days or proportion of delayed discharges for elderly inpatients in acute hospitals. Descriptive and regression analyses were conducted. Data on proportions of delayed discharges were pooled using a random effects logistic model and the association of relevant factors was assessed. Mean costs of delayed discharge were calculated in USD adjusted for Purchasing Power Parity (PPP). Of 64 studies included, 52 (81.3%) reported delayed discharges as proportions of total hospital stay and 9 (14.1%) estimated the respective costs for these delays. Proportions of delayed discharges varied widely, from 1.6% to 91.3% with a weighted mean of 22.8%. This variation was also seen in studies from the same country, for example, in the United Kingdom, they ranged between 1.6% and 60.0%. No factor was found to be significantly associated with delays. The mean costs of delayed discharge also varied widely (between 142 and 31,935 USD PPP adjusted), reflecting the variability in mean days of delay per patient. Delayed discharges occur in most countries and the associated costs are significant. However, the variability in prevalence of delayed discharges and available data on costs limit our knowledge of the full impact of delayed discharges. A standardization of methods is necessary to allow comparisons to be made, and additional studies are required-preferably by disease area-to determine the postdischarge needs of specific patient groups and the estimated costs of delays. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Value of the post-operative CT in predicting delayed flap failures following head and neck cancer surgery

    International Nuclear Information System (INIS)

    Kim, Bitna; Yoon, Dae Young; Seo, Young Lan; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo; Chung, Chul Hoon

    2017-01-01

    To identify post-operative computed tomography (CT) findings associated with delayed flap failures following head and neck cancer surgery. We retrospectively reviewed 60 patients who underwent flap reconstruction after head and neck cancer surgery and post-operative (3–14 days) contrast-enhanced CT scans for suspected complications. Patients were divided into two groups: delayed flap failure patients (patients required flap revision) (n = 18) and flap success patients (n = 42). Clinical data (age, sex, T-stage, type of flap, and time interval between reconstruction surgery and CT) and post-operative CT findings of flap status (maximum dimension of the flap, intra- or peri-flap fluid collection and intra- or peri-flap air collection, fat infiltration within the flap, fistula to adjacent aerodigestive tract or skin, and enhanced vascular pedicle) were assessed and compared between the two groups. CT findings showed that the following flap anomalies were observed more frequently in the delayed flap failure group than in the flap success group: intra- or peri-flap fluid collection > 4 cm (61.1% vs. 23.8%, p 2 cm (61.1% vs. 2.4%, p < 0.001), and fistula to adjacent aerodigestive tract or skin (44.4% vs. 0%, p < 0.001). The maximum dimension of the flap, fat infiltration within the flap, and enhanced vascular pedicle were not associated with delayed flap failures. A large amount of fluid or air collection and fistula are the CT findings that were associated with delayed flap failures in patients with suspected post-operative complications after head and neck cancer surgery

  7. Discounting of Monetary Rewards that are Both Delayed and Probabilistic: Delay and Probability Combine Multiplicatively, not Additively

    Science.gov (United States)

    Vanderveldt, Ariana; Green, Leonard; Myerson, Joel

    2014-01-01

    The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). Despite being well-described by the same hyperboloid function, delay and probability discounting involve fundamentally different processes, as revealed, for example, by the differential effects of reward amount. Previous research has focused on the discounting of delayed and probabilistic rewards separately, with little research examining more complex situations in which rewards are both delayed and probabilistic. In two experiments, participants made choices between smaller rewards that were both immediate and certain and larger rewards that were both delayed and probabilistic. Analyses revealed significant interactions between delay and probability factors inconsistent with an additive model. In contrast, a hyperboloid discounting model in which delay and probability were combined multiplicatively provided an excellent fit to the data. These results suggest that the hyperboloid is a good descriptor of decision making in complicated monetary choice situations like those people encounter in everyday life. PMID:24933696

  8. TASK, 1-D Multigroup Diffusion or Transport Theory Reactor Kinetics with Delayed Neutron

    International Nuclear Information System (INIS)

    Buhl, A.R.; Hermann, O.W.; Hinton, R.J.; Dodds, H.L. Jr.; Robinson, J.C.; Lillie, R.A.

    1975-01-01

    1 - Description of problem or function: TASK solves the one-dimensional multigroup form of the reactor kinetics equations, using either transport or diffusion theory and allowing an arbitrary number of delayed neutron groups. The program can also be used to solve standard static problems efficiently such as eigenvalue problems, distributed source problems, and boundary source problems. Convergence problems associated with sources in highly multiplicative media are circumvented, and such problems are readily calculable. 2 - Method of solution: TASK employs a combination scattering and transfer matrix method to eliminate certain difficulties that arise in classical finite difference approximations. As such, within-group (inner) iterations are eliminated and solution convergence is independent of spatial mesh size. The time variable is removed by Laplace transformation. (A later version will permit direct time solutions.) The code can be run either in an outer iteration mode or in closed (non-iterative) form. The running mode is dictated by the number of groups times the number of angles, consistent with available storage. 3 - Restrictions on the complexity of the problem: The principal restrictions are available storage and computation time. Since the code is flexibly-dimensioned and has an outer iteration option there are no internal restrictions on group structure, quadrature, and number of ordinates. The flexible-dimensioning scheme allows optional use of core storage. The generalized cylindrical geometry option is not complete in Version I of the code. The feedback options and omega-mode search options are not included in Version I

  9. Visuomotor Resolution in Telerobotic Grasping with Transmission Delays

    Directory of Open Access Journals (Sweden)

    Omri Afgin

    2017-10-01

    Full Text Available Weber’s law is among the basic psychophysical laws of human perception. It determines that human sensitivity to change along a physical dimension, the just noticeable difference (JND, is linearly related to stimulus intensity. Conversely, in direct (natural, visually guided grasping, Weber’s law is violated and the JND does not depend on stimulus intensity. The current work examines adherence to Weber’s law in telerobotic grasping. In direct grasping, perception and action are synchronized during task performance. Conversely, in telerobotic control, there is an inherent spatial and temporal separation between perception and action. The understanding of perception–action association in such conditions may facilitate development of objective measures for telerobotic systems and contribute to improved interface design. Moreover, telerobotic systems offer a unique platform for examining underlying causes for the violation of Weber’s law during direct grasping. We examined whether, like direct grasping, telerobotic grasping with transmission delays violates Weber’s law. To this end, we examined perceptual assessment, grasp control, and grasp demonstration, using a telerobotic system with time delays in two spatial orientations: alongside and facing the robot. The examination framework was adapted to telerobotics from the framework used for examining Weber’s law in direct grasping. The variability of final grip apertures (FGAs in perceptual assessment increased with object size in adherence with Weber’s law. Similarly, the variability of maximal grip apertures in grasp demonstration approached significance in adherence with Weber’s law. In grasp control, the variability of maximal grip apertures did not increase with object size, which seems to violate Weber’s law. However, unlike in direct grasping, motion trajectories were prolonged and fragmented, and included an atypical waiting period prior to finger closure. Therefore, in

  10. Scaling-Up Effective Language and Literacy Instruction: Evaluating the Importance of Scripting and Group Size Components

    DEFF Research Database (Denmark)

    Bleses, Dorthe; Højen, Anders; Dale, Philip

    2018-01-01

    participated in a cluster-randomized evaluation of three variations of a language-literacy focused curriculum (LEAP) comprising 40 twice-weekly 30-min lessons. LEAP-LARGE and LEAP-SMALL conditions involved educators’ implementation of a scope and sequence of objectives using scripted lessons provided to whole......-class and small groups, respectively. In LEAP-OPEN, educators followed the scope and sequence but were allowed to determine the instructional activities for each of 40 lessons (i.e., they received no scripted lessons). A business-as-usual (BAU) condition served as the control. Overall, the largest effect sizes...

  11. Modelling the relationship between soil color and particle size for soil survey in Ferralsol environments

    Directory of Open Access Journals (Sweden)

    B. Kone

    2009-05-01

    Full Text Available Soil texture is an important property for evaluating its inherent fertility especially by using pedo-transfers functions requiring particle size data. However, there is no existing quantitative method for in situ estimation of soil particle size, delaying judgement of soil chemical properties in the field. For this purpose, laboratory particle size analyses of 1028 samples from 281 Ferralsol profiles, located between latitudes 7º N and 10º N in Côte d’Ivoire and their respective colour notation by Munsell chart were used to generate prediction models. Multiple Linear Regression Analysis by Group was processed to identify clay, sand and silt contents in the soil based on color hue (2.5YR, 5YR, 7.5YR, and 10YR and Chroma (1, 2, 3, 4, 5, 6, 7, 8. The evaluation was conducted for each horizon coded as H1 (0-20 cm, H2 (20-60 cm, H3 (60-80 cm and H4 (80-150 cm and used as grouping variables. Highly significant (P< 0.001 models were identified for clay and sand. These models were used to estimate successfully clay and sand contents for other Ferralsol samples by comparing calculated and measured mean using the null hypothesis of difference and Tukey’s tests. They were accurate for at all depths, except 80 - 150 cm, for sand in 10YR soils. The method was deemed appropriate for in situ estimation of soil particle size contents in Ferralsol environment for improving reconnaissance agricultural soil surveys.

  12. Delayed enhanced MRI in intraparenchymal tumors

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

    1991-01-01

    Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

  13. Project delay analysis of HRSG

    Science.gov (United States)

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  14. A rare presentation of craniopharyngioma: delayed puberty

    Science.gov (United States)

    İnci, Mehmet Fatih; Özkan, Fuat; Bozkurt, Selim; Demir, Caner Feyzi

    2012-01-01

    Craniopharyngiomas are the most frequently encountered suprasellar tumours in children. Owing to the slow growth rate of these tumours, they are often quite large before becoming symptomatic. They are more common among children and older adults (55–74 years). Depending upon the direction of growth and tumour size, craniopharyngiomas can affect the hypothalamus, pituitary stalk, optic nerves and chiasm and carotid arteries. Compression of these neural and vascular structures frequently precipitates endocrine disorders, visual loss and an increased intracranial pressure. Hypopituitarism leading to a delayed puberty is a rare presentation of craniopharyngioma. The diagnosis of craniopharyngioma is usually made with the classic radiological imaging features based on CT and MRI. PMID:23195827

  15. Women's groups and individual entrepreneurs: a Ugandan case study.

    Science.gov (United States)

    Pickering, H; Kajura, E; Katongole, G; Whitworth, J

    1996-10-01

    This study is based on interviews conducted among 8 women's income-generating groups and 12 individual women entrepreneurs in 15 villages in Masaka district, Uganda. The Baganda are the main tribe in the study villages. The study evaluates the economic achievement, objectives, and social characteristics of the groups. Groups ranged in size from 9-20 members. All had functioned for 3-5 years. A regular membership fee was paid through the sale of agricultural produce. Groups met at least every 2 weeks. This study revealed that the individual goals were to increase individual wealth, while the stated group goals were to invest in the community. Members considered the groups as useful in providing an easy way to raise capital. Most members considered financial status as a criterion for group membership. Elderly women tended to join social and handicraft groups. The women's group members tended to be friends before the establishment of the group and tended to be currently married to men residing in the area. Of the 12 women entrepreneurs, only 5 were currently married. All 12 women entrepreneurs had considerable initiative. The 12 women and the women's group members derived income from two or more sources: agricultural projects, animal husbandry, craft production, alcohol production and sale, or other activities. Study findings indicate that decisions were often delayed or avoided in order to preserve social cohesion. In a market-oriented enterprise, quick response time is needed and the bureaucratic dynamics would hinder some agricultural ventures. The poorest women experienced barriers to group membership. Women entrepreneurs were more successful than group women.

  16. Nonlinear delay monopoly with bounded rationality

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2012-01-01

    The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

  17. Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective.

    Science.gov (United States)

    Göllner, Lars M; Ballhausen, Nicola; Kliegel, Matthias; Forstmeier, Simon

    2017-01-01

    The delay of gratification (DoG) in children is widely investigated with an experimental procedure originally called the "marshmallow test," whereas the studies on self-regulation (SR) in adolescents and adults usually use self-report questionnaires. Delay discounting (DD) measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP) and episodic future thinking (EFT)] as well as age differences in these constructs. Participants from five age groups (9-14, 18-25, 35-55, 65-80, 80+) participated in the study ( N = 96). While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC) was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest) in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification.

  18. On the combination of delayed neutron and delayed gamma techniques for fission rate measurement in nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Perret, G.; Jordan, K. A. [Paul Scherrer Institut, Villigen, 5232 (Switzerland)

    2011-07-01

    Novel techniques to measure newly induced fissions in spent fuel after re-irradiation at low power have been developed and tested at the Proteus zero-power research reactor. The two techniques are based on the detection of high energy gamma-rays emitted by short-lived fission products and delayed neutrons. The two techniques relate the measured signals to the total fission rate, the isotopic composition of the fuel, and nuclear data. They can be combined to derive better estimates on each of these parameters. This has potential for improvement in many areas. Spent fuel characterisation and safeguard applications can benefit from these techniques for non-destructive assay of plutonium content. Another application of choice is the reduction of uncertainties on nuclear data. As a first application of the combination of the delayed neutron and gamma measurement techniques, this paper shows how to reduce the uncertainties on the relative abundances of the longest delayed neutron group for thermal fissions in {sup 235}U, {sup 239}Pu and fast fissions in {sup 238}U. The proposed experiments are easily achievable in zero-power research reactors using fresh UO{sub 2} and MOX fuel and do not require fast extraction systems. The relative uncertainties (1{sigma}) on the relative abundances are expected to be reduced from 13% to 4%, 16% to 5%, and 38% to 12% for {sup 235}U, {sup 238}U and {sup 239}Pu, respectively. (authors)

  19. Memorized discrete systems and time-delay

    CERN Document Server

    Luo, Albert C J

    2017-01-01

    This book examines discrete dynamical systems with memory—nonlinear systems that exist extensively in biological organisms and financial and economic organizations, and time-delay systems that can be discretized into the memorized, discrete dynamical systems. It book further discusses stability and bifurcations of time-delay dynamical systems that can be investigated through memorized dynamical systems as well as bifurcations of memorized nonlinear dynamical systems, discretization methods of time-delay systems, and periodic motions to chaos in nonlinear time-delay systems. The book helps readers find analytical solutions of MDS, change traditional perturbation analysis in time-delay systems, detect motion complexity and singularity in MDS; and determine stability, bifurcation, and chaos in any time-delay system.

  20. Location in the right hemi-colon is an independent risk factor for delayed post-polypectomy hemorrhage: a multi-center case-control study.

    Science.gov (United States)

    Buddingh, K Tim; Herngreen, Thomas; Haringsma, Jelle; van der Zwet, Wil C; Vleggaar, Frank P; Breumelhof, Ronald; Ter Borg, Frank

    2011-06-01

    Delayed hemorrhage is an infrequent, but serious complication of colonoscopic polypectomy. Large size is the only polyp-related factor that has been unequivocally proven to increase the risk of delayed bleeding. It has been suggested that location in the right hemi-colon is also a risk factor. The objective of this study was to determine whether polyp location is an independent risk factor for delayed post-polypectomy hemorrhage. A retrospective case-control study was conducted in two university hospitals and two community hospitals. Thirty-nine cases and 117 controls were identified. In multivariate analysis, size and location were found to be independent polyp-related risk factors for delayed type hemorrhage. The risk increased by 13% for every 1 mm increase in polyp diameter (odds ratio (OR) 1.13, 95% confidence interval (CI) 1.05-1.20, Plocated in the right hemi-colon had an OR of 4.67 (1.88-11.61, P=0.001) for delayed hemorrhage. Polyps in the cecum seemed to be especially at high risk in univariate analysis (OR 13.82, 95% CI 2.66-71.73), but this could not be assessed in multivariate analysis as the number of cases was too small. Polyp type (sessile or pedunculated) was not a risk factor. Polyp location in the right hemi-colon seems to be an independent and substantial risk factor for delayed post-polypectomy hemorrhage. A low threshold for preventive hemostatic measures is advised when removing polyps from this region.

  1. Acceleration (Deceleration Model Supporting Time Delays to Refresh Data

    Directory of Open Access Journals (Sweden)

    José Gerardo Carrillo González

    2018-04-01

    Full Text Available This paper proposes a mathematical model to regulate the acceleration (deceleration applied by self-driving vehicles in car-following situations. A virtual environment is designed to test the model in different circumstances: (1 the followers decelerate in time if the leader decelerates, considering a time delay of up to 5 s to refresh data (vehicles position coordinates required by the model, (2 with the intention of optimizing space, the vehicles are grouped in platoons, where 3 s of time delay (to update data is supported if the vehicles have a centre-to-centre spacing of 20 m and a time delay of 1 s is supported at a spacing of 6 m (considering a maximum speed of 20 m/s in both cases, and (3 an algorithm is presented to manage the vehicles’ priority at a traffic intersection, where the model regulates the vehicles’ acceleration (deceleration and a balance in the number of vehicles passing from each side is achieved.

  2. Vernier Delay Unit

    International Nuclear Information System (INIS)

    Pierce, W.B.

    1984-10-01

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  3. Breaking Free of Sample Size Dogma to Perform Innovative Translational Research

    Science.gov (United States)

    Bacchetti, Peter; Deeks, Steven G.; McCune, Joseph M.

    2011-01-01

    Innovative clinical and translational research is often delayed or prevented by reviewers’ expectations that any study performed in humans must be shown in advance to have high statistical power. This supposed requirement is not justifiable and is contradicted by the reality that increasing sample size produces diminishing marginal returns. Studies of new ideas often must start small (sometimes even with an N of 1) because of cost and feasibility concerns, and recent statistical work shows that small sample sizes for such research can produce more projected scientific value per dollar spent than larger sample sizes. Renouncing false dogma about sample size would remove a serious barrier to innovation and translation. PMID:21677197

  4. Predictors of delay in starting radiation treatment for patients with early stage breast cancer

    International Nuclear Information System (INIS)

    Benk, Veronique; Ho, Vivian; Fortin, Paul R.; Zhang, G.; Levinton, Carey; Freeman, C.R.

    1998-01-01

    Purpose: To describe the factors predicting waiting time for radiation treatment in early breast cancer. Materials and Methods: Between January 1992 and December 1993, 739 patients with Stage I and II breast cancer were treated with conservative treatment at three McGill University Hospitals. Waiting time was defined as the interval between the date of surgery and the date of the first radiation treatment. Delay was defined as a waiting time of more than 7 weeks for women who did not receive chemotherapy (Group NC, n 478), and as a waiting time of more than 24 weeks for those who received chemotherapy (Group C, n = 261). We analyzed predictive factors related to the patient (age, stage, treatment on protocol, income by postal code) and to the referring hospital (university or community hospital). Results: For the entire population, 54% of patients were delayed, 72% in Group NC and 21.4% in Group C. Univariate analysis showed an impact of referring hospital in both groups, and of stage and treatment on protocol in Group C (all p = 0.001). Multivariate analysis showed that delays were significantly less in Group NC for women referred from a community hospital (p = 0.001) and in Group C for women with Stage I disease (p = 0.06), those treated on protocol, and those referred from a university hospital (p = 0.001). Conclusion: More than half of patients with early breast cancer waited more than the recommended intervals for radiation therapy. However, lower income breast cancer patients did not wait longer for treatment than higher income patients, possibly a result of the Canadian Medicare system which provides universal access to health care

  5. Pregnancy outcome of “delayed start” GnRH antagonist protocol versus GnRH antagonist protocol in poor responders: A clinical trial study

    Directory of Open Access Journals (Sweden)

    Abbas Aflatoonian

    2017-08-01

    Full Text Available Background: Management of poor-responding patients is still major challenge in assisted reproductive techniques (ART. Delayed-start GnRH antagonist protocol is recommended to these patients, but little is known in this regards. Objective: The goal of this study was assessment of delayed-start GnRH antagonist protocol in poor responders, and in vitro fertilization (IVF outcomes. Materials and Methods: This randomized clinical trial included sixty infertile women with Bologna criteria for ovarian poor responders who were candidate for IVF. In case group (n=30, delayed-start GnRH antagonist protocol administered estrogen priming followed by early follicular-phase GnRH antagonist treatment for 7 days before ovarian stimulation with gonadotropin. Control group (n=30 treated with estrogen priming antagonist protocol. Finally, endometrial thickness, the rates of oocytes maturation, , embryo formation, and pregnancy were compared between two groups. Results: Rates of implantation, chemical, clinical, and ongoing pregnancy in delayed-start cycles were higher although was not statistically significant. Endometrial thickness was significantly higher in case group. There were no statistically significant differences in the rates of oocyte maturation, embryo formation, and IVF outcomes between two groups. Conclusion: There is no significant difference between delayed-start GnRH antagonist protocol versus GnRH antagonist protocol.

  6. Incidence Probability of Delayed Health Consequences of the Chernobyl Accident

    International Nuclear Information System (INIS)

    Abdel-Ghani, A.H.; El-Naggar, A.M.; El-Kadi, A.A.

    2000-01-01

    During the first international Conference on the long -term consequences of the Chernobyl disaster in 1995 at Kiev, and also during the 1996 International Conference at Vienna, Summing up the consequences of the Chernobyl accident, the data regarding the delayed health consequences were mainly related to thyroid cancer, hereditary disorders, general morbidity, mortality and psychological disturbances. Contrary to expectations, the incidences of Leukemia and Soft Tissue tumors were similar to the spontaneous incident. The expected delayed effects, however, among the accident survivors, the liquidators and populations resident in contaminated areas would show higher incidence probability to Leukemia. These population groups have been continuously exposed to low level radiation both externally and internally. Application of the new ICRP concept of radiation-induced Detriment, and the Nominal Probability Coefficient for Cancer and hereditary effects for both workers and populations are used as the rationale to calculate the incidence probability of occurrence of delayed health effects of the Chernobyl accidents

  7. Delayed endovascular aortic repair is associated with reduced in-hospital mortality in patients with blunt thoracic aortic injury.

    Science.gov (United States)

    Marcaccio, Christina L; Dumas, Ryan P; Huang, Yanlan; Yang, Wei; Wang, Grace J; Holena, Daniel N

    2018-02-13

    The traditional approach to stable blunt thoracic aortic injury (BTAI) endorsed by the Society for Vascular Surgery is early (<24 hours) thoracic endovascular aortic repair (TEVAR). Recently, some studies have shown improved mortality in stable BTAI patients repaired in a delayed manner (≥24 hours). However, the indications for use of delayed TEVAR for BTAI are not well characterized, and its overall impact on the patient's survival remains poorly understood. We sought to determine whether delayed TEVAR is associated with a decrease in mortality compared with early TEVAR in this population. We conducted a retrospective cohort study of adult patients with BTAI (International Classification of Diseases, Ninth Revision diagnosis code 901.0) who underwent TEVAR (International Classification of Diseases, Ninth Revision procedure code 39.73) from 2009 to 2013 using the National Sample Program data set. Missing physiologic data were imputed using chained multiple imputation. Patients were parsed into groups based on the timing of TEVAR (early, <24 hours, vs delayed, ≥24 hours). The χ 2 , Mann-Whitney, and Fisher exact tests were used to compare baseline characteristics and outcomes of interest between groups. Multivariable logistic regression for mortality was performed that included all variables significant at P ≤ .2 in univariate analyses. A total of 2045 adult patients with BTAI were identified, of whom 534 (26%) underwent TEVAR. Patients with missing data on TEVAR timing were excluded (n = 27), leaving a total of 507 patients for analysis (75% male; 69% white; median age, 40 years [interquartile range, 27-56 years]; median Injury Severity Score [ISS], 34 [interquartile range, 26-41]). Of these, 378 patients underwent early TEVAR and 129 underwent delayed TEVAR. The two groups were similar with regard to age, sex, race, ISS, and presenting physiology. Mortality was 11.9% in the early TEVAR group vs 5.4% in the delayed group, with the early group

  8. Comorbid depression, antisocial personality, and substance dependence: Relationship with delay discounting.

    Science.gov (United States)

    Moody, Lara; Franck, Christopher; Bickel, Warren K

    2016-03-01

    Within the field of addiction, as many as four-fifths of individuals in treatment for substance use disorder have co-existing lifetime psychopathology and as high as two-thirds have current psychopathology. Among substance-dependent individuals, excessive delay discounting is pervasive. Despite evidence of excessive discounting across substance use disorders, few studies have investigated the impact of co-occurring psychopathologies and SUD on delay discounting. We compared delay discounting in currently abstaining substance users with (a) SUD (n=166), (b) SUD and managed major depressive disorder (MDD; n=44), (c) SUD and antisocial personality disorder (APD; n=35), (d) SUD and managed MDD and APD (n=22) and (e) no SUD or co-occurring psychopathology (n=60). All groups with SUD discounted future delayed rewards significantly more than healthy controls (p<0.001 in each case, d=0.686, 0.835, 1.098 and 1.650, respective to groups a-d above). Individuals with both APD and SUD and individuals with MDD, APD, and SUD discounted future rewards significantly more than substance users without comorbid psychopathology (p=0.029, d=0.412 and p<0.001, d=0.964, respectively). Overall, individuals with multiple psychopathologies in addition to substance use have exacerbated deficits in discounting of the future, above and beyond that observed in substance use alone. Increased discounting in combined substance and psychopathology profiles suggest a greater chance of treatment failure and therefore may necessitate individualized treatment using adjunctive interventions to achieve better treatment outcomes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Exponential synchronization of two nonlinearly non-delayed and delayed coupled complex dynamical networks

    International Nuclear Information System (INIS)

    Zheng Song

    2012-01-01

    In this paper, the exponential synchronization between two nonlinearly coupled complex networks with non-delayed and delayed coupling is investigated with Lyapunov-Krasovskii-type functionals. Based on the stability analysis of the impulsive differential equation and the linear matrix inequality, sufficient delay-dependent conditions for exponential synchronization are derived, and a linear impulsive controller and simple updated laws are also designed. Furthermore, the coupling matrices need not be symmetric or irreducible. Numerical examples are presented to verify the effectiveness and correctness of the synchronization criteria obtained.

  10. Prevalence of delayed emergence of permanent teeth as a result of local factors.

    Science.gov (United States)

    Johnsen, D C

    1977-01-01

    Delayed emergence of permanent teeth as a result of local etiologic factors was found in 45 of 1,032(4.3%) persons ages 8 through 18 in a dentally indigent population. In 36 persons (3.4%) delayed emergence resulted from causes other than those associated with premature primary molar extraction. This statistic probably approximates the potential for this problem in a treated population group. Teeth most commonly involved were mandibular second premolars, maxillary canines, and maxillary central incisors. The most common causes, respectively, were space loss, palatal position, and mesiodens. Supernumerary, malformed, and congenitally missing teeth were more frequent in persons with delayed emergence than in the rest of the population sampled. The difference was statistically significant. No correlation was found between delayed emergence and sex of the patient. In this study, teeth delayed in emergence behaved as other teeth in that they exhibited normal root development and did not contribute to resorption of adjacent roots. Except for maxillary canines, enlarged follicular spaces did not develop after eruption

  11. Delay Discounting of Video Game Players: Comparison of Time Duration Among Gamers.

    Science.gov (United States)

    Buono, Frank D; Sprong, Matthew E; Lloyd, Daniel P; Cutter, Christopher J; Printz, Destiny M B; Sullivan, Ryan M; Moore, Brent A

    2017-02-01

    Video game addiction or Internet game disorder, as proposed by the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), has similar criterion characteristics to other impulse control disorders. There is limited research examining video game addiction within a behavioral economic framework using delay discounting. The current study evaluated delay-discounting patterns of money and video game play by usual weekly hours of video game play. A total of 104 participants were split into 1 of 3 groups of video game players (low, medium, and high) and were asked to complete a monetary and video game discounting procedure through an online survey. Results showed significant differences between groups within both the monetary (p = 0.003) and video game discounting procedures (p = 0.004). Additionally, a positive linear relationship was noted between the groups across both procedures. The results of the current article reinforce previous findings that more hours of video game use are associated with greater impulsivity and provide implications for future research.

  12. Delay-Range-Dependent H∞ Control for Automatic Mooring Positioning System with Time-Varying Input Delay

    Directory of Open Access Journals (Sweden)

    Xiaoyu Su

    2014-01-01

    Full Text Available Aiming at the economy and security of the positioning system in semi-submersible platform, the paper presents a new scheme based on the mooring line switching strategy. Considering the input delay in switching process, H∞ control with time-varying input delay is designed to calculate the control forces to resist disturbing forces. In order to reduce the conservativeness, the information of the lower bound of delay is taken into account, and a Lyapunov function which contains the range of delay is constructed. Besides, the input constraint is considered to avoid breakage of mooring lines. The sufficient conditions for delay-range-dependent stabilization are derived in terms of LMI, and the controller is also obtained. The effectiveness of the proposed approach is illustrated by a realistic design example.

  13. The Japanese diet from 1975 delays senescence and prolongs life span in SAMP8 mice.

    Science.gov (United States)

    Yamamoto, Kazushi; E, Shuang; Hatakeyama, Yu; Sakamoto, Yu; Honma, Taro; Jibu, Yuri; Kawakami, Yuki; Tsuduki, Tsuyoshi

    2016-01-01

    Life expectancy in Japan is high, suggesting that the Japanese diet, Nihon shoku (Japanese food), has significant health benefits. However, these benefits have been called into question over the past 50 y, during which time the Japanese diet has become increasingly Westernized. The aim of the present study was to focus on senescence delay and to examine the effects of Japanese diets from different years to identify which Japanese diet is most effective in enhancing life expectancy and delaying senescence. Weekly menus from the years 1960, 1975, 1990, and 2005 were reproduced based on the National Health and Nutrition Survey in Japan and prepared as powdered foods. The senescence-accelerated mouse prone 8 (SAMP8) mice were fed standard laboratory chow supplemented with a 30% mix of Japanese meals from various years ad libitum throughout their lifetime. Additionally, the control group was given standard laboratory chow only, to examine the development of mice reared under standard conditions. In the group that ingested the traditional 1975 Japanese diet, life span was prolonged, senescence was delayed, and learning and memory capacities were maintained compared with the group fed the 2005 Japanese diet. The life span of the group that ingested the 1990 Japanese diet showed a tendency to be longer than SAMP8 mice fed the 2005 diet. The results of the present study suggested that the traditional Japanese diet is more effective in enhancing life expectancy and delaying senescence than the current Japanese diet. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Systematic of delayed neutron parameters

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  15. Delayed frost growth on jumping-drop superhydrophobic surfaces.

    Science.gov (United States)

    Boreyko, Jonathan B; Collier, C Patrick

    2013-02-26

    Self-propelled jumping drops are continuously removed from a condensing superhydrophobic surface to enable a micrometric steady-state drop size. Here, we report that subcooled condensate on a chilled superhydrophobic surface are able to repeatedly jump off the surface before heterogeneous ice nucleation occurs. Frost still forms on the superhydrophobic surface due to ice nucleation at neighboring edge defects, which eventually spreads over the entire surface via an interdrop frost wave. The growth of this interdrop frost front is shown to be up to 3 times slower on the superhydrophobic surface compared to a control hydrophobic surface, due to the jumping-drop effect dynamically minimizing the average drop size and surface coverage of the condensate. A simple scaling model is developed to relate the success and speed of interdrop ice bridging to the drop size distribution. While other reports of condensation frosting on superhydrophobic surfaces have focused exclusively on liquid-solid ice nucleation for isolated drops, these findings reveal that the growth of frost is an interdrop phenomenon that is strongly coupled to the wettability and drop size distribution of the surface. A jumping-drop superhydrophobic condenser minimized frost formation relative to a conventional dropwise condenser in two respects: preventing heterogeneous ice nucleation by continuously removing subcooled condensate, and delaying frost growth by limiting the success of interdrop ice bridge formation.

  16. Delay-Dependent Guaranteed Cost H∞ Control of an Interval System with Interval Time-Varying Delay

    Directory of Open Access Journals (Sweden)

    Zhongke Shi

    2009-01-01

    Full Text Available This paper concerns the problem of the delay-dependent robust stability and guaranteed cost H∞ control for an interval system with time-varying delay. The interval system with matrix factorization is provided and leads to less conservative conclusions than solving a square root. The time-varying delay is assumed to belong to an interval and the derivative of the interval time-varying delay is not a restriction, which allows a fast time-varying delay; also its applicability is broad. Based on the Lyapunov-Ktasovskii approach, a delay-dependent criterion for the existence of a state feedback controller, which guarantees the closed-loop system stability, the upper bound of cost function, and disturbance attenuation lever for all admissible uncertainties as well as out perturbation, is proposed in terms of linear matrix inequalities (LMIs. The criterion is derived by free weighting matrices that can reduce the conservatism. The effectiveness has been verified in a number example and the compute results are presented to validate the proposed design method.

  17. The role of size in synchronous air breathing of Hoplosternum littorale.

    Science.gov (United States)

    Sloman, Katherine A; Sloman, Richard D; De Boeck, Gudrun; Scott, Graham R; Iftikar, Fathima I; Wood, Chris M; Almeida-Val, Vera M F; Val, Adalberto L

    2009-01-01

    Synchronized air breathing may have evolved as a way of minimizing the predation risk known to be associated with air breathing in fish. Little is known about how the size of individuals affects synchronized air breathing and whether some individuals are required to surface earlier than necessary in support of conspecifics, while others delay air intake. Here, the air-breathing behavior of Hoplosternum littorale held in groups or in isolation was investigated in relation to body mass, oxygen tensions, and a variety of other physiological parameters (plasma lactate, hepatic glycogen, hematocrit, hemoglobin, and size of heart, branchial basket, liver, and air-breathing organ [ABO]). A mass-specific relationship with oxygen tension of first surfacing was seen when fish were held in isolation; smaller individuals surfaced at higher oxygen tensions. However, this relationship was lost when the same individuals were held in social groups of four, where synchronous air breathing was observed. In isolation, 62% of fish first surfaced at an oxygen tension lower than the calculated P(crit) (8.13 kPa), but in the group environment this was reduced to 38% of individuals. Higher oxygen tensions at first surfacing in the group environment were related to higher levels of activity rather than any of the physiological parameters measured. In fish held in isolation but denied access to the water surface for 12 h before behavioral testing, there was no mass-specific relationship with oxygen tension at first surfacing. Larger individuals with a greater capacity to store air in their ABOs may, therefore, remain in hypoxic waters for longer periods than smaller individuals when held in isolation unless prior access to the air is prevented. This study highlights how social interaction can affect air-breathing behaviors and the importance of considering both behavioral and physiological responses of fish to hypoxia to understand the survival mechanisms they employ.

  18. Interaction between carbon fibers and polymer sizing: Influence of fiber surface chemistry and sizing reactivity

    Science.gov (United States)

    Moosburger-Will, Judith; Bauer, Matthias; Laukmanis, Eva; Horny, Robert; Wetjen, Denise; Manske, Tamara; Schmidt-Stein, Felix; Töpker, Jochen; Horn, Siegfried

    2018-05-01

    Different aspects of the interaction of carbon fibers and epoxy-based polymer sizings are investigated, e.g. the wetting behavior, the strength of adhesion between fiber and sizing, and the thermal stability of the sizing layer. The influence of carbon fiber surface chemistry and sizing reactivity is investigated using fibers of different degree of anodic oxidation and sizings with different number of reactive epoxy groups per molecule. Wetting of the carbon fibers by the sizing dispersion is found to be specified by both, the degree of fiber activation and the sizing reactivity. In contrast, adhesion strength between fibers and sizing is dominated by the surface chemistry of the carbon fibers. Here, the number of surface oxygen groups seems to be the limiting factor. We also find that the sizing and the additional functionalities induced by anodic oxidation are removed by thermal treatment at 600 °C, leaving the carbon fiber in its original state after carbonization.

  19. Analysis Of Packets Delay In Wireless Data Networks

    Directory of Open Access Journals (Sweden)

    Krivchenkov Aleksandr

    2015-12-01

    Full Text Available The networks with wireless links for automation control applications traffic transmission when packets have small size and application payload is predictable are under consideration. Analytical model for packets delay on their propagation path through the network is proposed. Estimations for network architectures based on WiFi and Bluetooth wireless technologies are made. The specifications for physical layer 802.11 a/b/g/n and 802.15.1 are under consideration. Analytical and experimental results for delivered network bandwidth for different network architecture, traffic structure and wireless technologies were compared to validate that basic mechanisms are correctly taken into account in the model. It is shown that basic effects are taken into account and further accuracy “improvement” of the model will give not more than 5%. As a result that is important for automation control applications we have reliably received the lowest possible level for packets delay in one wireless link. For 802.11 it is of order of 0.2 ms, for 802.15.1 it is 1.25 ms and is true when application packet can be transferred by one data frame.

  20. Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics.

    Science.gov (United States)

    Boulet, Jason; Balasubramaniam, Ramesh; Daffertshofer, Andreas; Longtin, André

    2010-01-28

    We report on experiments and modelling involving the 'visuo-postural control loop' in the upright stance. We experimentally manipulated an artificial delay to the visual feedback during standing, presented at delays ranging from 0 to 1 s in increments of 250 ms. Using stochastic delay differential equations, we explicitly modelled the centre-of-pressure (COP) and centre-of-mass (COM) dynamics with two independent delay terms for vision and proprioception. A novel 'drifting fixed point' hypothesis was used to describe the fluctuations of the COM with the COP being modelled as a faster, corrective process of the COM. The model was in good agreement with the data in terms of probability density functions, power spectral densities, short- and long-term correlations (Hurst exponents) as well the critical time between the two ranges. This journal is © 2010 The Royal Society