WorldWideScience

Sample records for size groups delay

  1. BOLD delay times using group delay in sickle cell disease

    Science.gov (United States)

    Coloigner, Julie; Vu, Chau; Bush, Adam; Borzage, Matt; Rajagopalan, Vidya; Lepore, Natasha; Wood, John

    2016-03-01

    Sickle cell disease (SCD) is an inherited blood disorder that effects red blood cells, which can lead to vasoocclusion, ischemia and infarct. This disease often results in neurological damage and strokes, leading to morbidity and mortality. Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique for measuring and mapping the brain activity. Blood Oxygenation Level-Dependent (BOLD) signals contain also information about the neurovascular coupling, vascular reactivity, oxygenation and blood propagation. Temporal relationship between BOLD fluctuations in different parts of the brain provides also a mean to investigate the blood delay information. We used the induced desaturation as a label to profile transit times through different brain areas, reflecting oxygen utilization of tissue. In this study, we aimed to compare blood flow propagation delay times between these patients and healthy subjects in areas vascularized by anterior, middle and posterior cerebral arteries. In a group comparison analysis with control subjects, BOLD changes in these areas were found to be almost simultaneous and shorter in the SCD patients, because of their increased brain blood flow. Secondly, the analysis of a patient with a stenosis on the anterior cerebral artery indicated that signal of the area vascularized by this artery lagged the MCA signal. These findings suggest that sickle cell disease causes blood propagation modifications, and that these changes could be used as a biomarker of vascular damage.

  2. 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)

  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. 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.

  5. Practice Utilization of Algorithms for Analog Filter Group Delay Optimization

    Directory of Open Access Journals (Sweden)

    K. Hajek

    2007-04-01

    Full Text Available This contribution deals with an application of three different algorithms which optimize a group delay of analog filters. One of them is a part of the professional circuit simulator Micro Cap 7 and the others two original algorithms are developed in the MATLAB environment. An all-pass network is used to optimize the group delay of an arbitrary analog filter. Introduced algorithms look for an optimal order and optimal coefficients of an all-pass network transfer function. Theoretical foundations are introduced and all algorithms are tested using the optimization of testing analog filter. The optimization is always run three times because the second, third and fourth-order all-pass network is used. An equalization of the original group delay is a main objective of these optimizations. All outputs of all algorithms are critically evaluated and also described.

  6. Group delay functions and its applications in speech technology

    Indian Academy of Sciences (India)

    Fourier transform phase; group delay functions; feature extraction from phase; feature switching; mutual information; K-L divergence. 1. Introduction. Speech is the output of a quasistationary process, since the characteristics of speech change con- tinuously with time. As the ear perceives frequencies to understand sound, ...

  7. Very compact UWB antenna with group delay improvement

    Directory of Open Access Journals (Sweden)

    Tahanian Esmaeel

    2015-01-01

    Full Text Available In this paper, very compact (12mm×17mm and simple UWB antenna is proposed. The achieved bandwidth of the presented antenna is from 3.05 GHz to 12.5 GHz and in the most of the bandwidth, the return loss is less than -20dB. In addition to frequency characteristics, time characteristics such as group delay variations for three different antenna positions, namely, front to front, back to back and side by side using CST MW studio are simulated and discussed. To improve the group delay variations, by changing the radius of the circle on the back side of the antenna, the antenna gain in different frequencies will be tuned, therefore, the time domain characteristics of the proposed antenna are greatly improved.

  8. Design of resonant mirrors with negative group delay.

    Science.gov (United States)

    Gellineau, Antonio; Wong, Yu-Po; Solgaard, Olav

    2014-11-17

    Resonant mirrors introduce large spectral gradients in reflected phase while maintaining high reflectivity, allowing synthesis of optimized reflected phase for many practical applications. In this paper we show theoretically that asymmetry is required for negative group delay in lossless mirrors and explore the limits of reflected phase in resonant mirrors through the use of coupled mode theory and rigorous couple wave analysis. Our coupled mode theory shows that the phase response of resonant mirrors is determined by interacting resonances and gives insight into tradeoffs in design of mirrors with desired phase response.

  9. 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)

  10. Group size and seasonal pattern of occurrence of humpback ...

    African Journals Online (AJOL)

    The occurrence of humpback dolphins Sousa chinensis and their group size in Algoa Bay, South Africa, are described for the period May 1991–May 1994. The mean group size of dolphins was seven (ranging between 3 and 24). Group size was not affected by diurnal, tidal or lunar variability. Solitary, large individuals were ...

  11. Impact of size and delay on neural activity in the rat limbic corticostriatal system

    Directory of Open Access Journals (Sweden)

    Matthew R Roesch

    2011-12-01

    Full Text Available A number of factors influence an animal’s economic decisions. Two most commonly studied are the magnitude of and delay to reward. To investigate how these factors are represented in the firing rates of single neurons, we devised a behavioral task that independently manipulated the expected delay to and size of reward. Rats perceived the differently delayed and sized rewards as having different values and were more motivated under short-delay and big-reward conditions than under long-delay and small-reward conditions as measured by percent choice, accuracy and reaction time. Since the creation of this task, we have recorded from several different brain areas including, orbitofrontal cortex, striatum, amygdala, substantia nigra pars reticulata, and midbrain dopamine neurons. Here, we review and compare those data with a substantial focus on those areas that have been shown to be critical for performance on classic time discounting procedures and provide a potential mechanism by which they might interact when animals are deciding between differently delayed rewards. We found that most brain areas in the cortico-limbic circuit encode both the magnitude and delay to reward delivery in one form or another, but only a few encode them together at the single neuron level.

  12. Setting strategy of delay-optimization-oriented SMAC contention window size.

    Science.gov (United States)

    Rao, Yuan; Deng, Cheng; Su, Jun; Qiao, Yan; Zhu, Jun; Wang, Ru-Chuan

    2017-01-01

    Some frame components, such as SYNC (frame synchronization) and RTS/CTS (Ready to Send/Clear to Send), are not taken into consideration when the traditional setting strategies conduct the optimization of SMAC (Sensor MAC) contention window size. This paper proposes mathematical models that allow the analysis of data packets forwarding delay within one SMAC virtual cluster. Simulation results in OMNeT++ show good agreements with the proposed mathematical models, validating the models' correctness. The curve analyses of the models confirm the existence of delay-optimization-oriented contention window size that is closely related to the number of simultaneously contending nodes. Afterwards, it is shown that SYNC, RTS/CTS and EIFS (Extended InterFrame Space) have impacts on the optimal contention window size and expected delivery delay to various degrees, as well as throughput and energy efficiency. One ideal setting strategy of delay-optimization-oriented SMAC contention window size requires the combination of the network scale, SYNC, RTS/CTS and EIFS. Additionally, it is demonstrated that the proposed setting strategy makes contributions to the improvement in the existing SMAC extensions when they are integrated with each other, in terms of the end-to-end delay, throughput and energy consumption.

  13. Setting strategy of delay-optimization-oriented SMAC contention window size.

    Directory of Open Access Journals (Sweden)

    Yuan Rao

    Full Text Available Some frame components, such as SYNC (frame synchronization and RTS/CTS (Ready to Send/Clear to Send, are not taken into consideration when the traditional setting strategies conduct the optimization of SMAC (Sensor MAC contention window size. This paper proposes mathematical models that allow the analysis of data packets forwarding delay within one SMAC virtual cluster. Simulation results in OMNeT++ show good agreements with the proposed mathematical models, validating the models' correctness. The curve analyses of the models confirm the existence of delay-optimization-oriented contention window size that is closely related to the number of simultaneously contending nodes. Afterwards, it is shown that SYNC, RTS/CTS and EIFS (Extended InterFrame Space have impacts on the optimal contention window size and expected delivery delay to various degrees, as well as throughput and energy efficiency. One ideal setting strategy of delay-optimization-oriented SMAC contention window size requires the combination of the network scale, SYNC, RTS/CTS and EIFS. Additionally, it is demonstrated that the proposed setting strategy makes contributions to the improvement in the existing SMAC extensions when they are integrated with each other, in terms of the end-to-end delay, throughput and energy consumption.

  14. Setting strategy of delay-optimization-oriented SMAC contention window size

    Science.gov (United States)

    Deng, Cheng; Su, Jun; Qiao, Yan; Zhu, Jun; Wang, Ru-chuan

    2017-01-01

    Some frame components, such as SYNC (frame synchronization) and RTS/CTS (Ready to Send/Clear to Send), are not taken into consideration when the traditional setting strategies conduct the optimization of SMAC (Sensor MAC) contention window size. This paper proposes mathematical models that allow the analysis of data packets forwarding delay within one SMAC virtual cluster. Simulation results in OMNeT++ show good agreements with the proposed mathematical models, validating the models’ correctness. The curve analyses of the models confirm the existence of delay-optimization-oriented contention window size that is closely related to the number of simultaneously contending nodes. Afterwards, it is shown that SYNC, RTS/CTS and EIFS (Extended InterFrame Space) have impacts on the optimal contention window size and expected delivery delay to various degrees, as well as throughput and energy efficiency. One ideal setting strategy of delay-optimization-oriented SMAC contention window size requires the combination of the network scale, SYNC, RTS/CTS and EIFS. Additionally, it is demonstrated that the proposed setting strategy makes contributions to the improvement in the existing SMAC extensions when they are integrated with each other, in terms of the end-to-end delay, throughput and energy consumption. PMID:28732020

  15. 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

  16. Enhanced Group Delay of the Pulse Reflection with Graphene Surface Plasmon via Modified Otto Configuration

    Directory of Open Access Journals (Sweden)

    Guimei Li

    2017-01-01

    Full Text Available In this paper, the group delay of the transverse magnetic (TM polarized wave reflected from a modified Otto configuration with graphene surface plasmon is investigated theoretically. The findings show that the optical group delay in this structure can be enhanced negatively and can be switched from negative to positive due to the excitation of surface plasmon by graphene. It is clear that the negative group delay can be actively tuned through the Fermi energy of the graphene. Furthermore, the delay properties can also be manipulated by changing either the relaxation time of graphene or the distance between the coupling prism and the graphene. These tunable delay characteristics are promising for fabricating grapheme-based optical delay devices and other applications in the terahertz regime.

  17. 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

  18. Group Size Predicts Social but Not Nonsocial Cognition in Lemurs.

    Science.gov (United States)

    Maclean, Evan L; Sandel, Aaron A; Bray, Joel; Oldenkamp, Ricki E; Reddy, Rachna B; Hare, Brian A

    2013-01-01

    The social intelligence hypothesis suggests that living in large social networks was the primary selective pressure for the evolution of complex cognition in primates. This hypothesis is supported by comparative studies demonstrating a positive relationship between social group size and relative brain size across primates. However, the relationship between brain size and cognition remains equivocal. Moreover, there have been no experimental studies directly testing the association between group size and cognition across primates. We tested the social intelligence hypothesis by comparing 6 primate species (total N = 96) characterized by different group sizes on two cognitive tasks. Here, we show that a species' typical social group size predicts performance on cognitive measures of social cognition, but not a nonsocial measure of inhibitory control. We also show that a species' mean brain size (in absolute or relative terms) does not predict performance on either task in these species. These data provide evidence for a relationship between group size and social cognition in primates, and reveal the potential for cognitive evolution without concomitant changes in brain size. Furthermore our results underscore the need for more empirical studies of animal cognition, which have the power to reveal species differences in cognition not detectable by proxy variables, such as brain size.

  19. Group-size diversity in public goods games.

    Science.gov (United States)

    Peña, Jorge

    2012-03-01

    Public goods games are models of social dilemmas where cooperators pay a cost for the production of a public good while defectors free ride on the contributions of cooperators. In the traditional framework of evolutionary game theory, the payoffs of cooperators and defectors result from interactions in groups formed by binomial sampling from an infinite population. Despite empirical evidence showing that group-size distributions in nature are highly heterogeneous, most models of social evolution assume that the group size is constant. In this article, I remove this assumption and explore the effects of having random group sizes on the evolutionary dynamics of public goods games. By a straightforward application of Jensen's inequality, I show that the outcome of general nonlinear public goods games depends not only on the average group size but also on the variance of the group-size distribution. This general result is illustrated with two nonlinear public goods games (the public goods game with discounting or synergy and the N-person volunteer's dilemma) and three different group-size distributions (Poisson, geometric, and Waring). The results suggest that failing to acknowledge the natural variation of group sizes can lead to an underestimation of the actual level of cooperation exhibited in evolving populations. © 2011 The Author. Evolution© 2011 The Society for the Study of Evolution.

  20. Conjugacy class sizes and solvability of finite groups

    Indian Academy of Sciences (India)

    of the notations and terminologies are standard and readers may refer to [6]. A well-known problem in group theory is to study the influence of conjugacy class sizes on the structure of a group. For instance, as regards to groups with conjugacy class sizes. {1, m}, Itô [3] proved that G is nilpotent, m = pa for some prime p, and ...

  1. Is size the only determinant of delayed abdominal closure in pediatric liver transplant?

    Science.gov (United States)

    Khorsandi, Shirin Elizabeth; Day, Arthur William Raven; Cortes, Miriam; Deep, Akash; Dhawan, Anil; Vilca-Melendez, Hector; Heaton, Nigel

    2017-03-01

    The aim was to determine the factors associated with the use of delayed abdominal closure in pediatric liver transplantation (LT) and whether this affected outcome. From a prospectively maintained database, transplants performed in children (≤18 years) were identified (October 2010 to March 2015). Primary abdominal closure was defined as mass closure performed at time of transplant. Delayed abdominal closure was defined as mass closure not initially performed at the same time as transplant; 230 children underwent LT. Of these, 176 (76.5%) had primary closure. Age was similar between the primary and delayed groups (5.0 ± 4.9 versus 3.9 ± 5.0 years; P = 0.13). There was no difference in the graft-to-recipient weight ratio (GRWR) in the primary and delayed groups (3.4 ± 2.8 versus 4.1 ± 2.1; P = 0.12). Children with acute liver failure (ALF) were more likely to experience delayed closure then those with chronic liver disease (CLD; P pediatric intensive care unit (PICU; P = 0.001), and required a shorter duration of ventilation (P Liver Transplantation 23 352-360 2017 AASLD. © 2016 by the American Association for the Study of Liver Diseases.

  2. 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.

  3. 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)

  4. Youth Assets and Delayed Coitarche across Developmental Age Groups

    Science.gov (United States)

    Aspy, Cheryl B.; Vesely, Sara K.; Tolma, Eleni L.; Oman, Roy F.; Rodine, Sharon; Marshall, LaDonna; Fluhr, Janene

    2010-01-01

    Cross-sectional studies suggest that assets are associated with youth abstinence, but whether these relationships are constant across developmental age groups has not been shown. Data for this study were obtained from two independent datasets collected across a 2-year period using in-person, in-home interviews of youth (52% female; 44% Caucasian,…

  5. 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

  6. Interdependent and Independent Group Contingencies with Immediate and Delayed Reinforcement for Controlling Classroom Behavior.

    Science.gov (United States)

    Crouch, Pamela Lynne; And Others

    1985-01-01

    Investigated the use of interdependent group contingency for on-task and disruptive behavior along with independent group contingency for disruptive behavior to prevent children from spoiling group reinforcement. Results demonstrated that the combination of group contingency systems and immediate and delayed consequences were effective in reducing…

  7. 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.

  8. Minimax passband group delay nonlinear FIR filter design without imposing desired phase response

    OpenAIRE

    Ho, Charlotte Yuk-Fan; Ling, Wing-Kuen; Dam, Hai Huyen; Yeo, Kok-Lay

    2011-01-01

    In this paper, a nonlinear phase finite impulse response (FIR) filter is designed without imposing a desired phase response. The maximum passband group delay of the filter is minimized subject to a positivity constraint on the passband group delay response of the filter as well as a specification on the maximum absolute difference between the desired magnitude square response and the designed magnitude square response over both the passband and the stopband. This filter design problem is a no...

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

    Indian Academy of Sciences (India)

    Abstract. Let G be a finite group. We prove as follows: Let G be a p-solvable group for a fixed prime p. If the conjugacy class sizes of all elements of primary and biprimary orders of G are {1, pa, n} with a and n two positive integers and (p, n) = 1, then G is p-nilpotent or G has abelian Sylow p-subgroups. Keywords. Conjugacy ...

  10. 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.

  11. Conjugacy class sizes and solvability of finite groups

    Indian Academy of Sciences (India)

    Let be a finite group and * be the set of primary, biprimary and triprimary elements of . We prove that if the conjugacy class sizes of * are {1,,,} with positive coprime integers and ,then is solvable. This extends a recent result of Kong (Manatsh. Math. 168(2)(2012) 267–271).

  12. 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.

  13. Specialization and group size: brain and behavioural correlates of colony size in ants lacking morphological castes.

    Science.gov (United States)

    Amador-Vargas, Sabrina; Gronenberg, Wulfila; Wcislo, William T; Mueller, Ulrich

    2015-02-22

    Group size in both multicellular organisms and animal societies can correlate with the degree of division of labour. For ants, the task specialization hypothesis (TSH) proposes that increased behavioural specialization enabled by larger group size corresponds to anatomical specialization of worker brains. Alternatively, the social brain hypothesis proposes that increased levels of social stimuli in larger colonies lead to enlarged brain regions in all workers, regardless of their task specialization. We tested these hypotheses in acacia ants (Pseudomyrmex spinicola), which exhibit behavioural but not morphological task specialization. In wild colonies, we marked, followed and tested ant workers involved in foraging tasks on the leaves (leaf-ants) and in defensive tasks on the host tree trunk (trunk-ants). Task specialization increased with colony size, especially in defensive tasks. The relationship between colony size and brain region volume was task-dependent, supporting the TSH. Specifically, as colony size increased, the relative size of regions within the mushroom bodies of the brain decreased in trunk-ants but increased in leaf-ants; those regions play important roles in learning and memory. Our findings suggest that workers specialized in defence may have reduced learning abilities relative to leaf-ants; these inferences remain to be tested. In societies with monomorphic workers, brain polymorphism enhanced by group size could be a mechanism by which division of labour is achieved. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  14. 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.

  15. Influence of Group Size and Group Composition on the Adhered Distance Headway

    NARCIS (Netherlands)

    Duives, D.C.; Daamen, W.; Hoogendoorn, S.P.

    2014-01-01

    Research into the influence of groups on pedestrian flow dynamics has been limited. Previous research found that group size influences the walking velocity of pedestrians within the group and as such the capacity the pedestrian infrastructure. This paper's aim is to provide quantitative insights

  16. 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

  17. Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size.

    Science.gov (United States)

    Grassi, Pablo R; Zaretskaya, Natalia; Bartels, Andreas

    2016-06-01

    The integration of local moving elements into a unified gestalt percept has previously been linked to the posterior parietal cortex. There are two possible interpretations for the lack of involvement of other occipital regions. The first is that parietal cortex is indeed uniquely functionally specialized to perform grouping. Another possibility is that other visual regions can perform grouping as well, but that the large spatial separation of the local elements used previously exceeded their neurons' receptive field (RF) sizes, preventing their involvement. In this study we distinguished between these two alternatives. We measured whole-brain activity using fMRI in response to a bistable motion illusion that induced mutually exclusive percepts of either an illusory global Gestalt or of local elements. The stimulus was presented in two sizes, a large version known to activate IPS only, and a version sufficiently small to fit into the RFs of mid-level dorsal regions such as V5/MT. We found that none of the separately localized motion regions apart from parietal cortex showed a preference for global Gestalt perception, even for the smaller version of the stimulus. This outcome suggests that grouping-by-motion is mediated by a specialized size-invariant mechanism with parietal cortex as its anatomical substrate. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. 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 rever...... complex functionalities based on surface plasmon refraction and group delay....

  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. Achieving High Absolute Accuracy for Group-Delay Measurements Using the Modulation Phase-Shift Technique

    Science.gov (United States)

    Dennis, T.; Williams, P. A.

    2005-11-01

    We have developed a modulation phase-shift (MPS) system for measuring relative group delay (RGD) in optical components with high absolute accuracy and simultaneously high temporal and wavelength resolution. Our 200-MHz system has a 3.2-pm wavelength resolution and has demonstrated a group-delay resolution of 0.072 ps for repeated measurements of an artifact based on a hydrogen-cyanide gas cell. The expanded uncertainty (2sigma) is +/-0.46 ps for a single spectral measurement (~ 3.4-pm steps) of a narrow 20-ps group-delay feature of the artifact. To our knowledge, this is the first time that the sources of measurement uncertainty for this technique have been described and quantified. A method for predicting the group delay of the gas-cell artifact from measured absorption spectra is described, and an uncertainty analysis for the prediction method is also presented. The implementation required to achieve results of the highest accuracy for both measurements and predictions is discussed.

  1. 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.

  2. 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

  3. 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.

  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. 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

  6. 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

  7. Choice of Antiviral Allocation Scheme for Pandemic Influenza Depends on Strain Transmissibility, Delivery Delay and Stockpile Size.

    Science.gov (United States)

    Lydeamore, Michael; Bean, Nigel; Black, Andrew J; Ross, Joshua V

    2016-02-01

    Recently, pandemic response has involved the use of antivirals. These antivirals are often allocated to households dynamically throughout the pandemic with the aim being to retard the spread of infection. A drawback of this is that there is a delay until infection is confirmed and antivirals are delivered. Here an alternative allocation scheme is considered, where antivirals are instead preallocated to households at the start of a pandemic, thus reducing this delay. To compare these two schemes, a deterministic approximation to a novel stochastic household model is derived, which allows efficient computation of key quantities such as the expected epidemic final size, expected early growth rate, expected peak size and expected peak time of the epidemic. It is found that the theoretical best choice of allocation scheme depends on strain transmissibility, the delay in delivering antivirals under a dynamic allocation scheme and the stockpile size. A broad summary is that for realistic stockpile sizes, a dynamic allocation scheme is superior with the important exception of the epidemic final size under a severe pandemic scenario. Our results, viewed in conjunction with the practical considerations of implementing a preallocation scheme, support a focus on attempting to reduce the delay in delivering antivirals under a dynamic allocation scheme during a future pandemic.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Group size of a permanent large group of agile mangabeys (Cercocebus agilis) at Bai Hokou, Central African Republic.

    Science.gov (United States)

    Devreese, Lieven; Huynen, Marie-Claude; Stevens, Jeroen M G; Todd, Angelique

    2013-01-01

    White-eyelid mangabeys (genus Cercocebus) live in groups of highly variable size. Because of their semi-terrestrial behaviour and preference for dense forest habitats, re-liable data on group size are scarce. During a 5-month study, we collected 17 group counts on a habituated group of agile mangabeys (C. agilis) at Bai Hokou in the Central African Republic. We found a stable group size of approximately 135 individuals. This permanent large grouping pattern is known to occur among several populations of white-eyelid mangabeys and is congruent with extreme group sizes reported in mandrills at Lopé in Gabon. Copyright © 2013 S. Karger AG, Basel.

  14. 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.

  15. 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)

  16. 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.

  17. The impact of group size on damaging behaviours, aggression, fear and stress in farm animals

    NARCIS (Netherlands)

    Rodenburg, T.B.; Koene, P.

    2007-01-01

    The aim of this review is to discuss the impact of group size on damaging behaviours, aggression, fear and stress in farm animals and to identify housing- and management options that can help to reduce problems caused by suboptimal group sizes. Increasing group size was found to increase the risk of

  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.

    2015-01-01

    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); 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. PMID:26018644

  19. 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.

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

    Indian Academy of Sciences (India)

    (G)). Hence the Sylow p-subgroup of G is abelian as required. Now by the hypothesis we suppose that x is a p-element of G such that [G : CG(x)] = pa. By Lemma 2.1, we know that the normal closure of x will be a p-group, say H. Let Z = CG(H).

  1. Perception of Groups, Size of Opposition, and Social Influence

    Science.gov (United States)

    Wilder, David A.

    1977-01-01

    Two experiments investigated the relationship between social influence and the number of persons attempting influence. Findings suggest that the manner in which persons are initially organized into groups and aggregates of individuals affects their persuasive impact on observers. (Editor/RK)

  2. 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 ...

  3. 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…

  4. Diagnostic difficulties and delays with chest wall chondrosarcoma: a Swedish population based Scandinavian Sarcoma Group study of 106 patients.

    Science.gov (United States)

    Widhe, Björn; Bauer, Henrik C F

    2011-04-01

    Bone sarcomas in Sweden are generally referred to a multidisciplinary team at specialized sarcoma centers. This practice is strictly followed for sarcomas of long bones, but not for chest wall chondrosarcomas. Delay in diagnosis and treatment is often considerable for bone sarcomas. This report focuses on the symptoms and diagnostic problems of chest wall chondrosarcoma and factors related to long doctor's delay. The material included all 106 consecutive patients with chondrosarcoma of the chest wall diagnosed in Sweden 1980-2002. Pathological specimens were re-evaluated and graded by the Scandinavian Sarcoma Group pathology board. Files from the very first medical visit for symptoms related to the chondrosarcoma were traced and used to characterize the initial symptoms and calculate patient's and doctor's delay. The most prominent initial symptom for the chest wall chondrosarcomas was a palpable mass found in 69% (73/106) of the patients at the first visit. Two-thirds of the patients experienced no local chest pain. A tumor was suspected at the first visit in 83% of the patients. Patients delay was median 3 (0-118) months and doctor's delay was 4.5 (0.1-197) months. Doctor's delay was >6 months for 40% of the patients. Patients with an initial plain chest radiograph interpreted as normal (35 patients), and/or normal or inconclusive results of a fine-needle aspiration biopsy had longer doctor's delay. Fine-needle aspiration cytology done at non-specialty units resulted in only 26% correct malignant diagnoses; at sarcoma centers 94% were correctly diagnosed. Long total delay was unfavorable. Patients who died from the chondrosarcoma had longer total delay (pChest wall chondrosarcoma presents as a lump, usually painless. Plain chest radiographs and fine-needle aspiration cytology, when done at a non-specialty center, are often normal or inconclusive. Patients should be referred to sarcoma centers for diagnosis and treatment.

  5. The number of cultural traits is correlated with female group size but not with male group size in chimpanzee communities.

    Directory of Open Access Journals (Sweden)

    Johan Lind

    Full Text Available 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 mothers. In Gombe, termite fishing has been shown to be transmitted from mother to offspring. Lastly, it is female chimpanzees that transfer between communities and thus have the possibility of bringing in novel cultural traits from other communities. From these observations we predicted that females are more important cultural carriers than males. Here we show that the reported number of cultural traits in chimpanzee communities correlates with the number of females in chimpanzee communities, but not with the number of males. Hence, our results suggest that females are the carriers of chimpanzee culture.

  6. The number of cultural traits is correlated with female group size but not with male group size in chimpanzee communities.

    Science.gov (United States)

    Lind, Johan; Lindenfors, Patrik

    2010-03-24

    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 mothers. In Gombe, termite fishing has been shown to be transmitted from mother to offspring. Lastly, it is female chimpanzees that transfer between communities and thus have the possibility of bringing in novel cultural traits from other communities. From these observations we predicted that females are more important cultural carriers than males. Here we show that the reported number of cultural traits in chimpanzee communities correlates with the number of females in chimpanzee communities, but not with the number of males. Hence, our results suggest that females are the carriers of chimpanzee culture.

  7. 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…

  8. 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).

  9. 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...

  10. 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 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.

  11. WMS-III Logical Memory performance after a two-week delay in temporal lobe epilepsy and control groups.

    Science.gov (United States)

    Bell, Brian D

    2006-11-01

    Conventional memory assessment may fail to identify memory dysfunction that is characterized by intact recall for a relatively brief period but rapid forgetting thereafter. This study assessed immediate memory and retention after 30-minute and two-week delays in a control group (n = 25) and a group of individuals with temporal lobe epilepsy (TLE, n = 25). For raw free recall, thematic unit, and recognition memory scores from the Wechsler Memory Scale-3rd ed. (WMS-III) Logical Memory (LM) subtest, there were no group x trial interactions and the TLE group performed significantly worse than the controls on all trials. At the individual level, none of the patients (0%) demonstrated isolated free recall impairment at the two-week delay when raw scores were analyzed, and one patient (4%) but also five controls (20%) did so when percent retention scores were examined. In summary, TLE patients did not demonstrate disproportionate forgetting over two weeks on a widely used story memory test.

  12. Interactions among social monitoring, anti-predator vigilance and group size in eastern grey kangaroos.

    Science.gov (United States)

    Favreau, François-René; Goldizen, Anne W; Pays, Olivier

    2010-07-07

    Group size is known to affect both the amount of time that prey animals spend in vigilance and the degree to which the vigilance of group members is synchronized. However, the variation in group-size effects reported in the literature is not yet understood. Prey animals exhibit vigilance both to protect themselves against predators and to monitor other group members, and both forms of vigilance presumably influence group-size effects on vigilance. However, our understanding of the patterns of individual investment underlying the time sharing between anti-predator and social vigilance is still limited. We studied patterns of variation in individual vigilance and the synchronization of vigilance with group size in a wild population of eastern grey kangaroos (Macropus giganteus) subject to predation, in particular focusing on peripheral females because we expected that they would exhibit both social and anti-predator vigilance. There was no global effect of group size on individual vigilance. The lack of group-size effect was the result of two compensating effects. The proportion of time individuals spent looking at other group members increased, whereas the proportion of time they spent scanning the environment decreased with group size; as a result, overall vigilance levels did not change with group size. Moreover, a degree of synchrony of vigilance occurred within groups and that degree increased with the proportion of vigilance time peripheral females spent in anti-predator vigilance. Our results highlight the crucial roles of both social and anti-predator components of vigilance in the understanding of the relationship between group size and vigilance, as well as in the synchronization of vigilance among group members.

  13. 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)

  14. Sex allocation adjustment to mating group size in a simultaneous hermaphrodite.

    Science.gov (United States)

    Janicke, Tim; Marie-Orleach, Lucas; De Mulder, Katrien; Berezikov, Eugene; Ladurner, Peter; Vizoso, Dita B; Schärer, Lukas

    2013-11-01

    Sex allocation theory is considered as a touchstone of evolutionary biology, providing some of the best supported examples for Darwinian adaptation. In particular, Hamilton's local mate competition theory has been shown to generate precise predictions for extraordinary sex ratios observed in many separate-sexed organisms. In analogy to local mate competition, Charnov's mating group size model predicts how sex allocation in simultaneous hermaphrodites is affected by the mating group size (i.e., the number of mating partners plus one). Until now, studies have not directly explored the relationship between mating group size and sex allocation, which we here achieve in the simultaneously hermaphroditic flatworm Macrostomum lignano. Using transgenic focal worms with ubiquitous expression of green-fluorescent protein (GFP), we assessed the number of wild-type mating partners carrying GFP+ sperm from these focal worms when raised in different social group sizes. This allowed us to test directly how mating group size was related to the sex allocation of focal worms. We find that the proportion of male investment initially increases with increasing mating group size, but then saturates as predicted by theory. To our knowledge, this is the first direct test of the mating group size model in a simultaneously hermaphroditic animal. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  15. 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.

  16. When is bigger better? The effects of group size on the evolution of helping behaviours.

    Science.gov (United States)

    Powers, Simon T; Lehmann, Laurent

    2017-05-01

    Understanding the evolution of sociality in humans and other species requires understanding how selection on social behaviour varies with group size. However, the effects of group size are frequently obscured in the theoretical literature, which often makes assumptions that are at odds with empirical findings. In particular, mechanisms are suggested as supporting large-scale cooperation when they would in fact rapidly become ineffective with increasing group size. Here we review the literature on the evolution of helping behaviours (cooperation and altruism), and frame it using a simple synthetic model that allows us to delineate how the three main components of the selection pressure on helping must vary with increasing group size. The first component is the marginal benefit of helping to group members, which determines both direct fitness benefits to the actor and indirect fitness benefits to recipients. While this is often assumed to be independent of group size, marginal benefits are in practice likely to be maximal at intermediate group sizes for many types of collective action problems, and will eventually become very small in large groups due to the law of decreasing marginal returns. The second component is the response of social partners on the past play of an actor, which underlies conditional behaviour under repeated social interactions. We argue that under realistic conditions on the transmission of information in a population, this response on past play decreases rapidly with increasing group size so that reciprocity alone (whether direct, indirect, or generalised) cannot sustain cooperation in very large groups. The final component is the relatedness between actor and recipient, which, according to the rules of inheritance, again decreases rapidly with increasing group size. These results explain why helping behaviours in very large social groups are limited to cases where the number of reproducing individuals is small, as in social insects, or where

  17. 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…

  18. 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...

  19. Ecological correlates of group-size variation in a resource-defense ungulate, the sedentary guanaco.

    Directory of Open Access Journals (Sweden)

    Andrea Marino

    Full Text Available For large herbivores, predation-risk, habitat structure and population density are often reported as major determinants of group size variation within and between species. However, whether the underlying causes of these relationships imply an ecological adaptation or are the result of a purely mechanistic process in which fusion and fragmentation events only depend on the rate of group meeting, is still under debate. The aim of this study was to model guanaco family and bachelor group sizes in contrasting ecological settings in order to test hypotheses regarding the adaptive significance of group-size variation. We surveyed guanaco group sizes within three wildlife reserves located in eastern Patagonia where guanacos occupy a mosaic of grasslands and shrublands. Two of these reserves have been free from predators for decades while in the third, pumas often prey on guanacos. All locations have experienced important changes in guanaco abundance throughout the study offering the opportunity to test for density effects. We found that bachelor group size increased with increasing density, as expected by the mechanistic approach, but was independent of habitat structure or predation risk. In contrast, the smaller and territorial family groups were larger in the predator-exposed than in the predator-free locations, and were larger in open grasslands than in shrublands. However, the influence of population density on these social units was very weak. Therefore, family group data supported the adaptive significance of group-size variation but did not support the mechanistic idea. Yet, the magnitude of the effects was small and between-population variation in family group size after controlling for habitat and predation was negligible, suggesting that plasticity of these social units is considerably low. Our results showed that different social units might respond differentially to local ecological conditions, supporting two contrasting hypotheses in a

  20. 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.

  1. Correlation of automorphism group size and topological properties with program-size complexity evaluations of graphs and complex networks

    Science.gov (United States)

    Zenil, Hector; Soler-Toscano, Fernando; Dingle, Kamaludin; Louis, Ard A.

    2014-06-01

    We show that numerical approximations of Kolmogorov complexity (K) of graphs and networks capture some group-theoretic and topological properties of empirical networks, ranging from metabolic to social networks, and of small synthetic networks that we have produced. That K and the size of the group of automorphisms of a graph are correlated opens up interesting connections to problems in computational geometry, and thus connects several measures and concepts from complexity science. We derive these results via two different Kolmogorov complexity approximation methods applied to the adjacency matrices of the graphs and networks. The methods used are the traditional lossless compression approach to Kolmogorov complexity, and a normalised version of a Block Decomposition Method (BDM) based on algorithmic probability theory.

  2. Brain size does not impact shoaling dynamics in unfamiliar groups of guppies (Poecilia reticulata).

    Science.gov (United States)

    Kotrschal, Alexander; Szorkovszky, Alexander; Romenskyy, Maksym; Perna, Andrea; Buechel, Severine D; Zeng, Hong-Li; Pelckmans, Kristiaan; Sumpter, David; Kolm, Niclas

    2018-02-01

    Collective movement is achieved when individuals adopt local rules to interact with their neighbours. How the brain processes information about neighbours' positions and movements may affect how individuals interact in groups. As brain size can determine such information processing it should impact collective animal movement. Here we investigate whether brain size affects the structure and organisation of newly forming fish shoals by quantifying the collective movement of guppies (Poecilia reticulata) from large- and small-brained selection lines, with known differences in learning and memory. We used automated tracking software to determine shoaling behaviour of single-sex groups of eight or two fish and found no evidence that brain size affected the speed, group size, or spatial and directional organisation of fish shoals. Our results suggest that brain size does not play an important role in how fish interact with each other in these types of moving groups of unfamiliar individuals. Based on these results, we propose that shoal dynamics are likely to be governed by relatively basic cognitive processes that do not differ in these brain size selected lines of guppies. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Rheotaxis performance increases with group size in a coupled phase model with sensory noise. The effects of noise and group size on rheotaxis

    Science.gov (United States)

    Chicoli, A.; Bak-Coleman, J.; Coombs, S.; Paley, D. A.

    2015-12-01

    Many fish exhibit rheotaxis, a behavior in which fish orient themselves relative to flow. Rheotaxis confers many benefits, including energetic cost savings and interception of drifting prey. Despite the fact that most species of fish school during at least some portion of their life, little is known about the importance of rheotactic behavior to schooling fish and, conversely, how the presence of nearby conspecifics affects rheotactic behavior. Understanding how rheotaxis is modified by social factors is thus of ecological importance. Here we present a mathematical model in the form of an all-to-all, coupled-oscillator framework over the non-Euclidean space of fish orientations to model group rheotactic behavior. Individuals in the model measure the orientation of their neighbors and the flow direction relative to their own orientation. These measures are corrupted by sensory noise. We study the effect of sensory noise and group size on internal (i.e., within the school) and external (i.e., with the flow) disagreement in orientation. We find that under noisy environmental conditions, increased group size improves rheotaxis. Results of this study have implications for understanding animal behavior, as well as for potential applications in bio-inspired engineering.

  4. The value of delaying hCG administration to enable maturation of medium-sized follicles in patients undergoing superovulation for IVF/ICSI.

    Science.gov (United States)

    Awonuga, Awoniyi O; Wheeler, Karen; Thakur, Mili; Jeelani, Roohi; Diamond, Michael P; Puscheck, Elizabeth E

    2018-02-01

    The purpose of the study is to determine whether continued stimulation of mature follicles to allow "catch up" growth of medium-sized follicles in assisted reproductive technology compromises the clinical pregnancy (CPR) and live birth (LBR) rates in IVF/ICSI cycles. This retrospective cohort study reviewed 200 first IVF ± ICSI cycles out of a total of 340 cycles with complete data. Women underwent stimulation protocols with gonadotropins (Gn) and GnRH antagonist. Treatment cycles were divided into two groups (Gp): hCG administration delayed despite the presence of two mature follicles, defined as ≥ 18 mm [Gp1, n = 79] and hCG administration given when there were two mature follicles [Gp2, n = 121]. The patients in Gp1 were significantly younger than those in Gp2 [32.9 (4.5) vs. 34.3 (4.8), p = 0.04] and needed a median of one more day of superovulation before ovulation was triggered with hCG. The extra days was associated with the use of 450 [75-2025] more Gn, such that at the time the hCG was administered, patient's in group 1 had developed significantly greater number of follicles ≥ 18 mm [mean (SD), 4.9 (1.8) vs. 3.4 (1.7), p hCG administration to allow further growth of the medium-sized follicles added further days of superovulation and cost without improvement in CPR and LBR.

  5. Producers and scroungers: feeding-type composition changes with group size in a socially foraging spider.

    Science.gov (United States)

    Dumke, Marlis; Herberstein, Marie E; Schneider, Jutta M

    2016-04-13

    In groups of socially foraging animals, feeding behaviour may change with group size in response to varying cost-benefit trade-offs. Numerous studies have described group-size effects on group-average feeding behaviour, particularly emphasizing an increase in scrounging incidence for larger groups, where individuals (scroungers) feed from the food sources others (producers) discovered. However, individual variation in feeding behaviour remains unconsidered in the vast majority of these studies even though theoretical models predict individuals to specialize in feeding tactic and anticipate higher scrounger-type frequencies in larger groups. We combined group-level and individual-level analyses of group-size effects on social foraging in the subsocial spider Australomisidia ergandros Lending novel experimental support to model predictions, we found that individuals specialize in feeding tactic and that higher scrounging and lower producing incidence in larger groups were mediated through shifts in the ratio of feeding types. Further, feeding-type specialization was not explained by innate individual differences in hunting ability as all feeding types were equally efficient in prey capture when foraging alone. Context adaptivity of feeding behaviour might allow this subsocial species to succeed under varying socioecological conditions. © 2016 The Author(s).

  6. Modeling group size and scalar stress by logistic regression from an archaeological perspective.

    Directory of Open Access Journals (Sweden)

    Gianmarco Alberti

    Full Text Available Johnson's scalar stress theory, describing the mechanics of (and the remedies to the increase in in-group conflictuality that parallels the increase in groups' size, provides scholars with a useful theoretical framework for the understanding of different aspects of the material culture of past communities (i.e., social organization, communal food consumption, ceramic style, architecture and settlement layout. Due to its relevance in archaeology and anthropology, the article aims at proposing a predictive model of critical level of scalar stress on the basis of community size. Drawing upon Johnson's theory and on Dunbar's findings on the cognitive constrains to human group size, a model is built by means of Logistic Regression on the basis of the data on colony fissioning among the Hutterites of North America. On the grounds of the theoretical framework sketched in the first part of the article, the absence or presence of colony fissioning is considered expression of not critical vs. critical level of scalar stress for the sake of the model building. The model, which is also tested against a sample of archaeological and ethnographic cases: a confirms the existence of a significant relationship between critical scalar stress and group size, setting the issue on firmer statistical grounds; b allows calculating the intercept and slope of the logistic regression model, which can be used in any time to estimate the probability that a community experienced a critical level of scalar stress; c allows locating a critical scalar stress threshold at community size 127 (95% CI: 122-132, while the maximum probability of critical scale stress is predicted at size 158 (95% CI: 147-170. The model ultimately provides grounds to assess, for the sake of any further archaeological/anthropological interpretation, the probability that a group reached a hot spot of size development critical for its internal cohesion.

  7. 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.

  8. 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.

  9. Information-based sample size re-estimation in group sequential design for longitudinal trials.

    Science.gov (United States)

    Zhou, Jing; Adewale, Adeniyi; Shentu, Yue; Liu, Jiajun; Anderson, Keaven

    2014-09-28

    Group sequential design has become more popular in clinical trials because it allows for trials to stop early for futility or efficacy to save time and resources. However, this approach is less well-known for longitudinal analysis. We have observed repeated cases of studies with longitudinal data where there is an interest in early stopping for a lack of treatment effect or in adapting sample size to correct for inappropriate variance assumptions. We propose an information-based group sequential design as a method to deal with both of these issues. Updating the sample size at each interim analysis makes it possible to maintain the target power while controlling the type I error rate. We will illustrate our strategy with examples and simulations and compare the results with those obtained using fixed design and group sequential design without sample size re-estimation. Copyright © 2014 John Wiley & Sons, Ltd.

  10. 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.

  11. 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.

  12. Evolution of Human-Like Social Grooming Strategies Regarding Richness and Group Size

    Directory of Open Access Journals (Sweden)

    Masanori Takano

    2018-01-01

    Full Text Available Human social strategies have evolved as an adaption to behave in complex societies. In such societies, humans intensively tend to cooperate with their closer friends, because they have to distribute their limited resources through cooperation (e.g., time, food, etc.. It also makes the situation difficult to have uniform social relationships (social grooming with all friends. Thus, the social relationship strengths often show a much skewed distribution (a power law distribution. Here we aim to show adaptivity of such social grooming strategies in order to explore the evolution of human social intelligence. We use a model in the framework of evolutionary games where the social grooming strategies evolve via building social relationships with cooperators. Simulation results demonstrate four evolutionary trends. One of the trends is similar to the strategy that humans use. We find that these trends depend on three parameters; individuals' richness, group sizes, and the amount of social grooming. The human-like strategy evolves in large poor groups. Moreover, the increase of the amount of social grooming makes the group size larger. Conversely, this implies that the same strategy evolves when the amount of social grooming is properly adjusted even if the group sizes are different. Our results are important in the sense that, between human and non-human primates, the differences of the group size and the amount of social grooming are significant.

  13. Predator biomass, prey density, and species composition effects on group size in recruit coral reef fishes

    Science.gov (United States)

    DeMartini, Edward E.; Anderson, Todd W.; Friedlander, Alan M.; Beets, James P.

    2011-01-01

    Group incidence and size are described for recruit parrotfishes, wrasses, and damselfishes on Hawaiian reefs over 3 years (2006–2008) at sites spanning the archipelago (20–28°N, 155–177°W). Coral-poor and coral-rich areas were surveyed at sites with both low (Hawaii Island) and high (Midway Atoll) predator densities, facilitating examination of relations among predator and recruit densities, habitat, and group metrics. Predator and recruit densities varied spatially and temporally, with a sixfold range in total recruit densities among years. Group (≥2 recruits) metrics varied with time and tracked predator and recruit densities and the proportion of schooling species. Groups often included heterospecifics whose proportion increased with group size. A non-saturating relationship between group size and recruit density suggests that the anti-predator benefits of aggregation exceeded competitive costs. Grouping behavior may have overarching importance for recruit survival—even at high recruit densities—and merits further study on Hawaiian reefs and elsewhere.

  14. Anomalous ring-down effects and breakdown of the decay rate concept in optical cavities with negative group delay

    International Nuclear Information System (INIS)

    Lauprêtre, T; Goldfarb, F; Bretenaker, F; Schwartz, S; Ghosh, R; Carusotto, I

    2012-01-01

    The propagation of light pulses through negative group velocity media is known to give rise to a number of paradoxical situations that seem to violate causality. The solution of these paradoxes has triggered the investigation of a number of interesting and unexpected features of light propagation. Here, we report a combined theoretical and experimental study of the ring-down oscillations in optical cavities filled with a medium with a sufficiently negative frequency dispersion to give a negative round-trip group delay time. We theoretically anticipate that causality imposes the existence of additional resonance peaks in the cavity transmission, resulting in a non-exponential decay of the cavity field and in a breakdown of the cavity decay rate concept. Our predictions are validated by simulations and by an experiment using a room-temperature gas of metastable helium atoms in the detuned electromagnetically induced transparency regime as the cavity medium. (paper)

  15. Sample size planning with the cost constraint for testing superiority and equivalence of two independent groups.

    Science.gov (United States)

    Guo, Jiin-Huarng; Chen, Hubert J; Luh, Wei-Ming

    2011-11-01

    The allocation of sufficient participants into different experimental groups for various research purposes under given constraints is an important practical problem faced by researchers. We address the problem of sample size determination between two independent groups for unequal and/or unknown variances when both the power and the differential cost are taken into consideration. We apply the well-known Welch approximate test to derive various sample size allocation ratios by minimizing the total cost or, equivalently, maximizing the statistical power. Two types of hypotheses including superiority/non-inferiority and equivalence of two means are each considered in the process of sample size planning. A simulation study is carried out and the proposed method is validated in terms of Type I error rate and statistical power. As a result, the simulation study reveals that the proposed sample size formulas are very satisfactory under various variances and sample size allocation ratios. Finally, a flowchart, tables, and figures of several sample size allocations are presented for practical reference. ©2011 The British Psychological Society.

  16. 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.

  17. Relational diversity and neighbourhood cohesion. Unpacking variety, balance and in-group size.

    Science.gov (United States)

    Koopmans, Ruud; Schaeffer, Merlin

    2015-09-01

    Ethnic diversity is typically measured by the well-known Hirschman-Herfindahl Index. This paper discusses the merits of an alternative approach, which is in our view better suited to tease out why and how ethnic diversity matters. The approach consists of two elements. First, all existing diversity indices are non-relational. From the viewpoint of theoretical accounts that attribute negative diversity effects to in-group favoritism and out-group threat, it should however matter whether, given a certain level of overall diversity, an individual belongs to a minority group or to the dominant majority. We therefore decompose diversity by distinguishing the in-group share from the diversity of ethnic out-groups. Second, we show how generalized entropy measures can be used to test which of diversity's two basic dimensions matters most: the variety of groups, or the unequal distribution (balance) of the population over groups. These measures allow us to test different theoretical explanations against each other, because they imply different expectations regarding the effects of in-group size, out-group variety, and out-group balance. We apply these ideas in an analysis of various social cohesion measures across 55 German localities and show that both in-group size and out-group diversity matter. For the native majority as well as for persons of immigration background, the variety component of diversity seems to be more decisive than has formerly been acknowledged. These findings provide little support for group threat and in-group favoritism as the decisive mechanisms behind negative diversity effects, and are most in line with the predictions of theories that emphasize coordination problems, asymmetric preferences, and network closure. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Crestal Bone Loss under Delayed Loading of Full Thickness Versus Flapless Surgically Placed Dental Implants in Controlled Type 2 Diabetic Patients: A Parallel Group Randomized Clinical Trial.

    Science.gov (United States)

    Yadav, Rohit; Agrawal, Kaushal Kishor; Rao, Jitendra; Anwar, Mohd; Alvi, Habib Ahmed; Singh, Kalpana; Himanshu, D

    2016-10-12

    To compare crestal bone loss around dental implants using a delayed loading protocol. Bone loss was compared in patients following conventional full thickness flap and flapless surgery in controlled type 2 diabetic patients. Eighty-eight type 2 diabetic patients satisfying predetermined inclusion and exclusion criteria were selected for this single center, parallel group study after obtaining institutional review board approval and informed consent. These patients were randomly divided into two groups. Group I consisted of patients undergoing full thickness flap surgery for implant placement, and group II consisted of patients undergoing flapless surgery for implant placement. The mean age, duration of diabetes, glycosylated hemoglobin levels, and male-to-female ratio in both groups were matched and compared statistically. Dental implants were placed followed by delayed loading (4 months) in both groups. Crestal bone loss was assessed with intraoral periapical radiographs with the help of computer software (DBSWIN viewer). Actual implant length acted as the radiographic index, and implant-abutment junctions were used as a reference point for all measurements. Mesial and distal bone levels at baseline, 6, and 12 months post implant placement of the two groups were determined. Mesial and distal crestal bone loss from baseline to 6 and 12 months were calculated and compared with Tukey test using SPSS v15.0 statistical analysis software. Tukey test revealed similar (not statistically different) mean mesial crestal bone loss between the two groups after 6 months (0.47 ± 0.08 mm vs. 0.36 ± 0.13 mm, p = 0.576) and after 12 months (1.56 ± 0.25 mm vs. 1.50 ± 0.22 mm, p = 0.891). The mean distal bone loss resulting between the two groups was not statistically different at 6 months (0.44 ± 0.08 mm vs. 0.35 ± 0.12 mm, p = 0.687) and at 12 months (1.57 ± 0.23 mm vs. 1.61 ± 0.22 mm, p = 0.947). The results of this clinical randomized control trial indicated that in

  19. 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.

  20. 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…

  1. Within-Group Effect-Size Benchmarks for Problem-Solving Therapy for Depression in Adults

    Science.gov (United States)

    Rubin, Allen; Yu, Miao

    2017-01-01

    This article provides benchmark data on within-group effect sizes from published randomized clinical trials that supported the efficacy of problem-solving therapy (PST) for depression among adults. Benchmarks are broken down by type of depression (major or minor), type of outcome measure (interview or self-report scale), whether PST was provided…

  2. Estimating group size and population density of Eurasian badgers Meles meles by quantifying latrine use

    NARCIS (Netherlands)

    Tuyttens, F.A.M.; Long, B.; Fawcett, T.W.; Skinner, A.; Brown, J.A.; Cheeseman, C.L.; Roddam, A.W.; MacDonald, D.W.

    2001-01-01

    1. Conservation issues and a potential role in disease transmission generate the continued need to census Eurasian badgers Meles metes, but direct counts and sett counts present difficulties. The feasibility of estimating social group size and population density of badgers by quantifying their use

  3. 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…

  4. 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.

  5. 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.

  6. Male group size, female distribution and changes in sexual segregation by Roosevelt elk.

    Directory of Open Access Journals (Sweden)

    Leah M Peterson

    Full Text Available Sexual segregation, or the differential use of space by males and females, is hypothesized to be a function of body size dimorphism. Sexual segregation can also manifest at small (social segregation and large (habitat segregation spatial scales for a variety of reasons. Furthermore, the connection between small- and large-scale sexual segregation has rarely been addressed. We studied a population of Roosevelt elk (Cervus elaphus roosevelti across 21 years in north coastal California, USA, to assess small- and large-scale sexual segregation in winter. We hypothesized that male group size would associate with small-scale segregation and that a change in female distribution would associate with large-scale segregation. Variation in forage biomass might also be coupled to small and large-scale sexual segregation. Our findings were consistent with male group size associating with small-scale segregation and a change in female distribution associating with large-scale segregation. Females appeared to avoid large groups comprised of socially dominant males. Males appeared to occupy a habitat vacated by females because of a wider forage niche, greater tolerance to lethal risks, and, perhaps, to reduce encounters with other elk. Sexual segregation at both spatial scales was a poor predictor of forage biomass. Size dimorphism was coupled to change in sexual segregation at small and large spatial scales. Small scale segregation can seemingly manifest when all forage habitat is occupied by females and large scale segregation might happen when some forage habitat is not occupied by females.

  7. Integration of individual and social information for decision-making in groups of different sizes.

    Science.gov (United States)

    Park, Seongmin A; Goïame, Sidney; O'Connor, David A; Dreher, Jean-Claude

    2017-06-01

    When making judgments in a group, individuals often revise their initial beliefs about the best judgment to make given what others believe. Despite the ubiquity of this phenomenon, we know little about how the brain updates beliefs when integrating personal judgments (individual information) with those of others (social information). Here, we investigated the neurocomputational mechanisms of how we adapt our judgments to those made by groups of different sizes, in the context of jury decisions for a criminal. By testing different theoretical models, we showed that a social Bayesian inference model captured changes in judgments better than 2 other models. Our results showed that participants updated their beliefs by appropriately weighting individual and social sources of information according to their respective credibility. When investigating 2 fundamental computations of Bayesian inference, belief updates and credibility estimates of social information, we found that the dorsal anterior cingulate cortex (dACC) computed the level of belief updates, while the bilateral frontopolar cortex (FPC) was more engaged in individuals who assigned a greater credibility to the judgments of a larger group. Moreover, increased functional connectivity between these 2 brain regions reflected a greater influence of group size on the relative credibility of social information. These results provide a mechanistic understanding of the computational roles of the FPC-dACC network in steering judgment adaptation to a group's opinion. Taken together, these findings provide a computational account of how the human brain integrates individual and social information for decision-making in groups.

  8. Integration of individual and social information for decision-making in groups of different sizes.

    Directory of Open Access Journals (Sweden)

    Seongmin A Park

    2017-06-01

    Full Text Available When making judgments in a group, individuals often revise their initial beliefs about the best judgment to make given what others believe. Despite the ubiquity of this phenomenon, we know little about how the brain updates beliefs when integrating personal judgments (individual information with those of others (social information. Here, we investigated the neurocomputational mechanisms of how we adapt our judgments to those made by groups of different sizes, in the context of jury decisions for a criminal. By testing different theoretical models, we showed that a social Bayesian inference model captured changes in judgments better than 2 other models. Our results showed that participants updated their beliefs by appropriately weighting individual and social sources of information according to their respective credibility. When investigating 2 fundamental computations of Bayesian inference, belief updates and credibility estimates of social information, we found that the dorsal anterior cingulate cortex (dACC computed the level of belief updates, while the bilateral frontopolar cortex (FPC was more engaged in individuals who assigned a greater credibility to the judgments of a larger group. Moreover, increased functional connectivity between these 2 brain regions reflected a greater influence of group size on the relative credibility of social information. These results provide a mechanistic understanding of the computational roles of the FPC-dACC network in steering judgment adaptation to a group's opinion. Taken together, these findings provide a computational account of how the human brain integrates individual and social information for decision-making in groups.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. The effect of group size on the interplay between dominance and reproduction in Bombus terrestris.

    Science.gov (United States)

    Amsalem, Etya; Hefetz, Abraham

    2011-03-28

    Social insects provide good model systems for testing trade-offs in decision-making because of their marked reproductive skew and the dilemma workers face when to reproduce. Attaining reproductive skew requires energy investment in aggression or fertility signaling, creating a trade-off between reproduction and dominance. This may be density-dependent because the cost of achieving dominance may be higher in larger groups. We investigated the effect of group-size in B. terrestris queenless workers on two major reproduction-dominance correlates: between-worker aggression, and pheromone production, aiming at mimicking decision-making during the transition of worker behavior from cooperation and sterility to aggressive reproductive competition in whole colonies. Despite the competition, reproductive division of labor in colonies can be maintained even during this phase through the production of a sterility signal by sterile workers that has an appeasement effect on dominant nestmates. Worker-worker aggression, ovary activation, and production of sterility-appeasement signals may therefore constitute components of a trade-off affecting worker reproduction decisions. By constructing queenless groups of different size and measuring how this affected the parameters above, we found that in all groups aggression was not evenly distributed with the α-worker performing most of the aggressive acts. Moreover, aggression by the α-worker increased proportionally with group-size. However, while in small groups the α-worker monopolized reproduction, in larger groups several workers shared reproduction, creating two worker groups: reproductives and helpers. It appears that despite the increase of aggression, this was evidently not sufficient for the α-worker to monopolize reproduction. If we compare the α-worker to the queen in full-sized colonies it can be hypothesized that worker reproduction in B. terrestris colonies starts due to a gradual increase in the worker population

  14. The Absolute Total Delayed Neutron Yields, Relative Abundances and Half-Lives of Delayed Neutron Groups from Neutron Induced Fission of 232Th, 233U, 236U, 239Pu and 241Am

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Egorov, A.S.; Mitrofanov, K.V.

    2013-10-01

    The absolute total yield, relative yields and half-lives of individual delayed neutron groups produced from fast neutron-induced fission of 232 Th, 233 U, 236 U, 239 Pu and 241 Am are measured by performing cyclic irradiations of the sample and subsequently measuring the time dependence of the delayed neutron activity decay. The data are analysed using an iterative least-squares fitting procedure to estimate the temporary delayed neutron parameters both for the 6- and 8-group models at each incident neutron energy. The improved data contribute to the continuing effort to meet the data requirements emerging from the current trends in reactor technologies, including the growing interest in fuel recycling strategies and new concepts of actinide burners. (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. Fewer but better: Proportionate size of the group affects evaluation of transgressive leaders.

    Science.gov (United States)

    Travaglino, Giovanni A; Abrams, Dominic; Randsley de Moura, Georgina; Yetkili, Orkun

    2016-06-01

    A group may be badly affected if its leader transgresses important rules. Nonetheless, an emerging body of evidence suggests that in intergroup contexts, group members apply a double standard when judging ingroup leaders - They respond less punitively to transgressions by their leader than by non-leaders. In this article, two experiments investigated how proportionate ingroup size affects reactions to transgressive ingroup leaders. We demonstrate that ingroup leaders from larger, but not smaller, groups benefit from the double standard. The experiments testing the effects of two different types of transgressions (nepotistic favouritism and corruption, respectively) show that transgressive leaders from larger groups are evaluated more positively than both comparable non-leaders and leaders from smaller groups. In contrast, transgressive leaders from smaller groups are evaluated similarly to comparable transgressive non-leaders. Experiment 2 investigated a potential explanation for this phenomenon. Faced with a transgressive leader, members of a smaller group report greater embarrassment than do members of larger groups in relation to the leaders' actions. Implications of these findings and directions for future research are discussed. © 2015 The British Psychological Society.

  17. Cognitive performance is linked to group size and affects fitness in Australian magpies.

    Science.gov (United States)

    Ashton, Benjamin J; Ridley, Amanda R; Edwards, Emily K; Thornton, Alex

    2018-02-15

    The social intelligence hypothesis states that the demands of social life drive cognitive evolution. This idea receives support from comparative studies that link variation in group size or mating systems with cognitive and neuroanatomical differences across species, but findings are contradictory and contentious. To understand the cognitive consequences of sociality, it is also important to investigate social variation within species. Here we show that in wild, cooperatively breeding Australian magpies, individuals that live in large groups show increased cognitive performance, which is linked to increased reproductive success. Individual performance was highly correlated across four cognitive tasks, indicating a 'general intelligence factor' that underlies cognitive performance. Repeated cognitive testing of juveniles at different ages showed that the correlation between group size and cognition emerged in early life, suggesting that living in larger groups promotes cognitive development. Furthermore, we found a positive association between the task performance of females and three indicators of reproductive success, thus identifying a selective benefit of greater cognitive performance. Together, these results provide intraspecific evidence that sociality can shape cognitive development and evolution.

  18. Sample-size calculations for multi-group comparison in population pharmacokinetic experiments.

    Science.gov (United States)

    Ogungbenro, Kayode; Aarons, Leon

    2010-01-01

    This paper describes an approach for calculating sample size for population pharmacokinetic experiments that involve hypothesis testing based on multi-group comparison detecting the difference in parameters between groups under mixed-effects modelling. This approach extends what has been described for generalized linear models and nonlinear population pharmacokinetic models that involve only binary covariates to more complex nonlinear population pharmacokinetic models. The structural nonlinear model is linearized around the random effects to obtain the marginal model and the hypothesis testing involving model parameters is based on Wald's test. This approach provides an efficient and fast method for calculating sample size for hypothesis testing in population pharmacokinetic models. The approach can also handle different design problems such as unequal allocation of subjects to groups and unbalanced sampling times between and within groups. The results obtained following application to a one compartment intravenous bolus dose model that involved three different hypotheses under different scenarios showed good agreement between the power obtained from NONMEM simulations and nominal power. Copyright © 2009 John Wiley & Sons, Ltd.

  19. 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.

  20. 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.

  1. Unravelling the size distribution of social groups with information theory in complex networks

    Science.gov (United States)

    Hernando, A.; Villuendas, D.; Vesperinas, C.; Abad, M.; Plastino, A.

    2010-07-01

    The minimization of Fisher’s information (MFI) approach of Frieden et al. [Phys. Rev. E 60, 48 (1999)] is applied to the study of size distributions in social groups on the basis of a recently established analogy between scale invariant systems and classical gases [Phys. A 389, 490 (2010)]. Going beyond the ideal gas scenario is seen to be tantamount to simulating the interactions taking place, for a competitive cluster growth process, in a scale-free ideal network - a non-correlated network with a connection-degree’s distribution that mimics the scale-free ideal gas density distribution. We use a scaling rule that allows one to classify the final cluster-size distributions using only one parameter that we call the competitiveness, which can be seen as a measure of the strength of the interactions. We find that both empirical city-size distributions and electoral results can be thus reproduced and classified according to this competitiveness-parameter, that also allow us to infer the maximum number of stable social relationships that one person can maintain, known as the Dunbar number, together with its standard deviation. We discuss the importance of this number in connection with the empirical phenomenon known as “six-degrees of separation”. Finally, we show that scaled city-size distributions of large countries follow, in general, the same universal distribution.

  2. 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.

  3. Side-group size effects on interfaces and glass formation in supported polymer thin films

    Science.gov (United States)

    Xia, Wenjie; Song, Jake; Hsu, David D.; Keten, Sinan

    2017-05-01

    Recent studies on glass-forming polymers near interfaces have emphasized the importance of molecular features such as chain stiffness, side-groups, molecular packing, and associated changes in fragility as key factors that govern the magnitude of Tg changes with respect to the bulk in polymer thin films. However, how such molecular features are coupled with substrate and free surface effects on Tg in thin films remains to be fully understood. Here, we employ a chemically specific coarse-grained polymer model for methacrylates to investigate the role of side-group volume on glass formation in bulk polymers and supported thin films. Our results show that bulkier side-groups lead to higher bulk Tg and fragility and are associated with a pronounced free surface effect on overall Tg depression. By probing local Tg within the films, however, we find that the polymers with bulkier side-groups experience a reduced confinement-induced increase in local Tg near a strongly interacting substrate. Further analyses indicate that this is due to the packing frustration of chains near the substrate interface, which lowers the attractive interactions with the substrate and thus lessens the surface-induced reduction in segmental mobility. Our results reveal that the size of the polymer side-group may be a design element that controls the confinement effects induced by the free surface and substrates in supported polymer thin films. Our analyses provide new insights into the factors governing polymer dynamics in bulk and confined environments.

  4. Wormlike micelles in poly(oxyethylene) surfactant solution: Growth control through hydrophilic-group size variation.

    Science.gov (United States)

    Ahmed, Toufiq; Aramaki, Kenji

    2008-11-01

    Viscoelastic micellar solutions are formed in poly(oxyethylene) cholesteryl ether (ChEO(m), m=15, 30) aqueous solutions on addition of tri(ethyleneglycol) mono n-dodecyl ether (C(12)EO(3)). The steady-shear and dynamic rheological behavior of the systems is characteristic of wormlike micellar solution. In either system, the plateau modulus (G(0)) and relaxation time (tau) are found to increase with increasing cosurfactant mixing fractions. The plateau modulus of the ChEO(30)-C(12)EO(3) system at the maximum viscosity region is found to be higher than that in the ChEO(15)-C(12)EO(3) system at the maximum viscosity region, whereas for the relaxation time the opposite relation is found. The maximum viscosities obtained in the two systems are of the same order of magnitude. In the ChEO(30)-C(12)EO(3) system, the maximum viscosity is obtained at a higher cosurfactant mixing fraction than that in the ChEO(15)-C(12)EO(3) system. It is concluded that decreasing the head-group size of the hydrophilic surfactant favors micellar growth. Monolaurin, another hydrophobic surfactant known to induce growth in some systems, is found to cause phase separation before significant micellar growth occurs in ChEO(m) solutions, although the effect of head-group size of ChEO(m) is found to be similar to the ChEO(m)-C(12)EO(3) systems.

  5. Comparison of infarct size changes with delayed contrast-enhanced magnetic resonance imaging and electrocardiogram QRS scoring during the 6 months after acutely reperfused myocardial infarction

    DEFF Research Database (Denmark)

    Bang, L.E.; Ripa, R.S.; Grande, P.

    2008-01-01

    that has infarcted. There are no comparison of serial changes on ECG and DE-MRI measuring infarct size. AIM: The general aim of this study was to describe the acute, healing, and chronic phases of the changes in infarct size estimated by the ECG and DE-MRI. The specific aim was to compare estimates......INTRODUCTION: Magnetic resonance imaging using the delayed contrast-enhanced (DE-MRI) method can be used for characterizing and quantifying myocardial infarction (MI). Electrocardiogram (ECG) score after the acute phase of MI can be used to estimate the portion of left ventricular myocardium...... of the Selvester QRS scoring system and DE-MRI to identify the difference between the extent of left ventricle occupied by infarction in the acute and chronic phases. METHODS: In 31 patients (26 men, age 56 +/- 9) with reperfused ST-elevation MI (11 anterior, 20 inferior), standard 12-lead ECG and DE-MRI were...

  6. 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.

  7. 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)

  8. 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…

  9. Generalisations of Hamilton's Rule Applied to Non-Additive Public Goods Games with Random Group Size

    Directory of Open Access Journals (Sweden)

    James A R Marshall

    2014-07-01

    Full Text Available Inclusive fitness theory has been described as being limited to certain special cases of social evolution. In particular some authors argue that the theory can only be applied to social interactions having additive fitness effects, and involving only pairs of individuals. This article takes an elegant formulation of non-additive public goods games from the literature, and shows how the two main generalisations of Hamilton's rule can be applied to such games when group sizes are random. In doing so inclusive fitness theory is thus applied to a very general class of social dilemmas, thereby providing further evidence for its generality. Interestingly, one of the two predominant versions of Hamilton's rule is found to be mathematically easier to apply to the scenario considered, despite both necessarily giving equivalent predictions.

  10. Does intruder group size and orientation affect flight initiation distance in birds?

    Directory of Open Access Journals (Sweden)

    Geist, C.

    2005-06-01

    Full Text Available Wildlife managers use flight initiation distance (FID, the distance animals flee an approaching predator, to determine set back distances to minimize human impacts on wildlife. FID is typically estimated by a single person; this study examined the effects of intruder number and orientation on FID. Three different group size treatments (solitary person, two people side-by-side, two people one-behind-the-other were applied to Pied Currawongs (Strepera graculina and to Crimson Rosellas (Platycerus elegans. Rosellas flushed at significantly greater distances when approached by two people compared to a single person. This effect was not seen in currawongs. Intruder orientation did not influence the FID of either species. Results suggest that intruder number should be better integrated into estimates of set back distance to manage human visitation around sensitive species.

  11. 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.

  12. 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.

  13. Evidences of delayed size recovery in Araucaria angustifolia populations after post-glacial colonization of highlands in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Valdir M. Stefenon

    2008-09-01

    Full Text Available Up to date, little is known about the relationship between historical demography and the current genetic structure of A. Angus As a first effort towards overcoming this lack, microsatellite data scored in six populations and isozyme allele frequencies published for 11 natural stands of this species were analysed in order to assess molecular signatures of populations' demographic history. Signatures of genetic bottlenecks were captured in all analysed populations of southeastern Brazil. Among southern populations, signatures of small effective population size were observed in only three out of 13 populations. Southern populations likely experienced faster recovery of population size after migration onto highlands. Accordingly, current genetic diversity of the southern populations gives evidence of fast population size recovery. In general, demographic history of A. Angusmatches climatic dynamics of southern and southeastern Brazil during the Pleistocene and Holocene. Palynological records and reconstruction of the past climatic dynamics of southeastern and southern Brazil support the hypothesis of different population size recovery dynamics for populations from these regions.Até o momento, pouco se conhece sobre a relação entre história demográfica e a presente estrutura genética da A. Angus Como uma primeira tentativa em transpor esta deficiência, dados de microssatélites coletados em seis populações e freqüências alélicas de isoenzimas publicadas para 11 populações naturais desta espécie foram analisadas com o objetivo de acessar assinaturas moleculares da história demográfica populacional. Assinaturas de gargalos genéticos foram capturadas em todas as populações analisadas provenientes do Sudeste do Brasil. Entre as populações do Sul, assinaturas de pequeno tamanho populacional efetivo foram observadas em somente três entre 13 populações. Populações do Sul provavelmente apresentaram uma rápida recuperação do

  14. Hyphal responses of Neurospora crassa to micron-sized beads with functional chemical surface groups

    Science.gov (United States)

    Held, Marie; Edwards, Clive; Nicolau, Dan V.

    2011-02-01

    Filamentous fungi include serious plant and animal pathogens that explore their environment efficiently in order to penetrate the host. This environment is physically and chemically heterogeneous and the fungi rely on specific physical and chemical signals to find the optimal point/s of attack. This study presents a methodology to introduce distinct structures with dimensions similar to the hyphal diameter and specific chemical surface groups into a controllable environment in order to study the fungal response. We introduced 3.3 μm polystyrene beads covered with Epoxy surface groups into microfluidic channels made from PDMS by rapid replica molding. The experimental setup resulted in different areas with low and high densities of beads as well as densely packed patches. The observations of the fungus exploring the areas long-term showed that the growth parameters were altered significantly, compared with the values measured on agar. The fungus responded to both, the physical and chemical parameters of the beads, including temporary directional changes, increased branching angles, decreased branching distances, decreased apical extension velocities and occasional cell wall lysis. The wealth and magnitude of the observed responses indicates that the microfluidic structures provide a powerful platform for the investigation of micron-sized features on filamentous fungi.

  15. Dependence of micelle size and shape on detergent alkyl chain length and head group.

    Science.gov (United States)

    Oliver, Ryan C; Lipfert, Jan; Fox, Daniel A; Lo, Ryan H; Doniach, Sebastian; Columbus, Linda

    2013-01-01

    Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins for functional and structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC) currently relies on empirical screening of detergents, and a stable and functional PDC is often not obtained. To provide a foundation for systematic comparisons between the properties of the detergent micelle and the resulting PDC, a comprehensive set of detergents commonly used for membrane protein studies are systematically investigated. Using small-angle X-ray scattering (SAXS), micelle shapes and sizes are determined for phosphocholines with 10, 12, and 14 alkyl carbons, glucosides with 8, 9, and 10 alkyl carbons, maltosides with 8, 10, and 12 alkyl carbons, and lysophosphatidyl glycerols with 14 and 16 alkyl carbons. The SAXS profiles are well described by two-component ellipsoid models, with an electron rich outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core composed of the alkyl chains. The minor axis of the elliptical micelle core from these models is constrained by the length of the alkyl chain, and increases by 1.2-1.5 Å per carbon addition to the alkyl chain. The major elliptical axis also increases with chain length; however, the ellipticity remains approximately constant for each detergent series. In addition, the aggregation number of these detergents increases by ∼16 monomers per micelle for each alkyl carbon added. The data provide a comprehensive view of the determinants of micelle shape and size and provide a baseline for correlating micelle properties with protein-detergent interactions.

  16. Dependence of micelle size and shape on detergent alkyl chain length and head group.

    Directory of Open Access Journals (Sweden)

    Ryan C Oliver

    Full Text Available Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins for functional and structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC currently relies on empirical screening of detergents, and a stable and functional PDC is often not obtained. To provide a foundation for systematic comparisons between the properties of the detergent micelle and the resulting PDC, a comprehensive set of detergents commonly used for membrane protein studies are systematically investigated. Using small-angle X-ray scattering (SAXS, micelle shapes and sizes are determined for phosphocholines with 10, 12, and 14 alkyl carbons, glucosides with 8, 9, and 10 alkyl carbons, maltosides with 8, 10, and 12 alkyl carbons, and lysophosphatidyl glycerols with 14 and 16 alkyl carbons. The SAXS profiles are well described by two-component ellipsoid models, with an electron rich outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core composed of the alkyl chains. The minor axis of the elliptical micelle core from these models is constrained by the length of the alkyl chain, and increases by 1.2-1.5 Å per carbon addition to the alkyl chain. The major elliptical axis also increases with chain length; however, the ellipticity remains approximately constant for each detergent series. In addition, the aggregation number of these detergents increases by ∼16 monomers per micelle for each alkyl carbon added. The data provide a comprehensive view of the determinants of micelle shape and size and provide a baseline for correlating micelle properties with protein-detergent interactions.

  17. Humpback whale Megaptera novaeangliae (Cetartiodactyla: Balaenopteridae group sizes in line transect ship surveys: An evaluation of observer errors

    Directory of Open Access Journals (Sweden)

    Guilherme A. Bortolotto

    2016-01-01

    Full Text Available ABSTRACT Accurate estimates of group sizes through line transect sampling methods are important to correctly ascertain the abundance of animals that occur in groups. Since the average observed group size is a component of the distance sampling formula, bias in these data leads to biased abundance estimates. This study aimed to evaluate the potential errors in group size estimation during line transect ship surveys to estimate abundances of the humpback whale, Megaptera novaeangliae (Borowski 1781. In a research cruise along the Brazilian coast, an experiment to collect group size information was conducted from two different sighting platforms on the same vessel. Group sizes were recorded by primary observers at first sighting (PO1 and, in some cases, after some time (PO2. A tracker (T was located on a higher platform to estimate the sizes of groups detected by the primary observers, but tracked one group at a time until it passed abeam. Thus, the dedicated effort to obtain multiple group counts (i.e. higher platform, more time and no responsibility for detecting new groups was expected to provide more accurate numbers. PO2 estimates were compared with PO1 estimates, and T estimates were compared with both PO1 and PO2. Additionally, ratios between T and both PO2 (R1 and PO1 (R2, and between PO2 and PO1 (R3 were calculated. To investigate a possible improvement in abundance estimates, a correction factor (CF was computed from the ratio of T and PO2 means. Primary observer self-correction (= 1.60, CV% = 70.3 was statistically similar to the correction for the tracker (= 1.62, CV% = 84.1. CF resulted in 1 and would not improve abundance estimates. This study supports that observers conducting line transect surveys on large whales have the potential to provide group size information that is as adequate as the correction procedure adopted.

  18. 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…

  19. Effect of environmental enrichment and group size on behaviour and live weight in growing rabbits

    Directory of Open Access Journals (Sweden)

    Daniela Zucca

    2012-07-01

    Full Text Available The aim of this research was to study the effects of group size and environmental enrichment on behaviour and growth of 108 hybrid growing rabbits (Oryctolagus cuniculus. We compared the behaviour (time budget and reactions to specific behavioural tests: “tonic immobility” and “emergence test” and live weight of growing rabbits housed in cages with a different number of rabbits per cage (2, 3 and 4; same density:14 rabbits/m2. Half of the cages were enriched with a wooden stick (Robinia Pseudoacacia, length: 20 cm – diameter: 6 cm, cylindrical hanging from the ceiling of the cage. The stick and number of animals per cage had no effect on weight gain or on behavioural tests responses. Interaction with the stick was significantly higher at the beginning of the growing period. Principal component analysis performed on the data for the whole period showed significant differences according to the treatments: increasing the number of rabbits per cage and introducing a wooden stick seemed to affect locomotor activity frequency and social interactions. Rabbits housed 3 and 4 per cage showed less lying behaviour and higher locomotor activity and sitting. The larger functional space allowance enabled rabbits to perform more natural behaviours compared to smaller cages (2 rabbits/cage. Environmental enrichment seems to be related to higher allogrooming behaviour frequency, which could indicate a social behaviour related to pheromonal olfactory stimulation and mutual recognition.

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

    African Journals Online (AJOL)

    shy, elusive and nocturnal habits of brown hyaenas and the physiognomic characteristics ... animals in the group. The present paper evaluates the use of this technique and is based on material and information collected from a group of three hyaenas studied between October 1982 and October. 1983. This group's territory ...

  1. The heterologous expression of a chrysanthemum TCP-P transcription factor CmTCP14 suppresses organ size and delays senescence in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Ting; Qu, Yixin; Wang, Haibin; Wang, Jingjing; Song, Aiping; Hu, Yueheng; Chen, Sumei; Jiang, Jiafu; Chen, Fadi

    2017-06-01

    TCP transcription factors are important for plant growth and development, but their activity in chrysanthemum (Chrysanthemum morifolium) has not been thoroughly explored. Here, a chrysanthemum TCP-P sequence, which encodes a protein harboring the conserved basic helix-loop-helix (bHLH) motif, was shown to be related phylogenetically to the Arabidopsis thaliana gene AtTCP14. A yeast-one hybrid assay showed that the encoding protein had no transcriptional activation ability, and a localization experiment indicated that it was localized in the nucleus. Transcription profiling established that the gene was most active in the stem and leaf. Its heterologous expression in A. thaliana down-regulated certain cell cycle-related genes, reduced the size of various organs and increased the chlorophyll and carotenoid contents of the leaf which led to delayed senescence and a prolonged flowering period. Moreover, by screening the cDNA library of chrysanthemum, we found that the CmTCP14 can interact with CmFTL2 and some CmDELLAs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. A behavioural Bayes approach to the determination of sample size for clinical trials considering efficacy and safety: imbalanced sample size in treatment groups.

    Science.gov (United States)

    Kikuchi, Takashi; Gittins, John

    2011-08-01

    The behavioural Bayes approach to sample size determination for clinical trials assumes that the number of subsequent patients switching to a new drug from the current drug depends on the strength of the evidence for efficacy and safety that was observed in the clinical trials. The optimal sample size is the one which maximises the expected net benefit of the trial. The approach has been developed in a series of papers by Pezeshk and the present authors (Gittins JC, Pezeshk H. A behavioral Bayes method for determining the size of a clinical trial. Drug Information Journal 2000; 34: 355-63; Gittins JC, Pezeshk H. How Large should a clinical trial be? The Statistician 2000; 49(2): 177-87; Gittins JC, Pezeshk H. A decision theoretic approach to sample size determination in clinical trials. Journal of Biopharmaceutical Statistics 2002; 12(4): 535-51; Gittins JC, Pezeshk H. A fully Bayesian approach to calculating sample sizes for clinical trials with binary responses. Drug Information Journal 2002; 36: 143-50; Kikuchi T, Pezeshk H, Gittins J. A Bayesian cost-benefit approach to the determination of sample size in clinical trials. Statistics in Medicine 2008; 27(1): 68-82; Kikuchi T, Gittins J. A behavioral Bayes method to determine the sample size of a clinical trial considering efficacy and safety. Statistics in Medicine 2009; 28(18): 2293-306; Kikuchi T, Gittins J. A Bayesian procedure for cost-benefit evaluation of a new drug in multi-national clinical trials. Statistics in Medicine 2009 (Submitted)). The purpose of this article is to provide a rationale for experimental designs which allocate more patients to the new treatment than to the control group. The model uses a logistic weight function, including an interaction term linking efficacy and safety, which determines the number of patients choosing the new drug, and hence the resulting benefit. A Monte Carlo simulation is employed for the calculation. Having a larger group of patients on the new drug in general

  3. Are infants with torticollis at risk of a delay in early motor milestones compared with a control group of healthy infants?

    Science.gov (United States)

    Ohman, Anna; Nilsson, Staffan; Lagerkvist, Anna-Lena; Beckung, Eva

    2009-07-01

    Recently it has been claimed that infants with congenital muscular torticollis (CMT) are at risk of a delay in early motor milestones. The aim of the present study was to investigate whether infants with CMT are indeed at risk in comparison with a control group of healthy infants. A second aim was to investigate whether the time spent in a prone position and plagiocephaly had any influence on motor development. Eighty-two infants with CMT (35 females and 47 males) were compared with 40 healthy infants (18 females and 22 males). Motor development was assessed with the Alberta Infant Motor scale (AIMS). Multiple regression showed that infants in the CMT group had a significantly lower AIMS score than the control group at 2 months (p=0.03) and 6 months of age (p=0.05). Infants who spent at least three occasions daily in a prone position when awake had significantly higher AIMS scores than infants who spent less time prone at 2 months (p=0.001), 6 months (pmotor milestones significantly later than the control group until the age of 10 months, but the risk of delay seems to be more strongly associated with little or no time prone when awake than with CMT.

  4. 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.

  5. Reducing visitors' group size increases the number of birds during educational activities: Implications for management of nature-based recreation.

    Science.gov (United States)

    Remacha, Carolina; Pérez-Tris, Javier; Delgado, Juan Antonio

    2011-06-01

    Organized tours to watch wildlife are popular recreational and educational activities, in which the visitor expectative (to observe as many and as diverse animals as possible) runs parallel to conservation purposes. However, the presence of visitors may cause negative impacts on wildlife, which makes recreation difficult to manage. Thus, restricting visitor's load to minimize impacts on fauna may be advisable, but too much restriction may end up disappointing the public. We analysed how visitors' group size influences the number and variety of birds observed during an educational activity directed to scholars, in a forested area where public access is otherwise restricted. We observed fewer birds, but not fewer species, as the size of scholars' groups increased. Such effect was apparently mediated by a few species demonstrating reduced tolerance to increased group size. Our results support the idea that reducing the size of visitors' groups not only helps to minimize the negative impacts on wildlife derived from leisure activities, but also allows visitors to watch more wildlife. Therefore, organizing visitors in small numbers is recommended in the design of activities directed to groups of people visiting natural areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. Delay guaranteed VoD services over group-based integrated fiber-wireless (FiWi) access networks with energy efficiency

    Science.gov (United States)

    Li, Yan; Dai, Shifang; Chang, Xiangmao

    2015-08-01

    In group-based fiber-wireless (FiWi) access networks, where wireless clients are divided into several groups according to their interested Internet services, VoD services will meet new challenges considering the diversity of video requesting probability for each wireless group. In this paper, we categorize wireless groups into "video-hot" group with great interest in VoD services and "video-cold" group with infrequent video requesting. For video requests from "video-hot" groups, we firstly propose an energy-efficient optical network unit (ONU) selection approach to reduce ONU power consumption by selecting a subset of ONUs to support such requests, then our previously proposed rebroadcast and patching scheme can be effectively applied. For video requests from "video-cold" groups, a batched multicasting scheme is presented for energy and bandwidth saving. Both of the VoD schemes mentioned in this study are with the aim to minimize worst-case playback delay (WPD) which is particularly important as Internet users. In view of that some ONUs may need to handle video requests from two kinds of group, optimal ONU channel assignment aims to minimize weighted overall WPD is also studied. The efficiency of the work is finally demonstrated by the simulations.

  9. How Many Focus Groups Are Enough? Building an Evidence Base for Nonprobability Sample Sizes

    Science.gov (United States)

    Guest, Greg; Namey, Emily; McKenna, Kevin

    2017-01-01

    Few empirical studies exist to guide researchers in determining the number of focus groups necessary for a research study. The analyses described here provide foundational evidence to help researchers in this regard. We conducted a thematic analysis of 40 focus groups on health-seeking behaviors of African American men in Durham, North Carolina.…

  10. The effects of group size on aggression when mixing unacquainted sows in outdoor paddocks

    Science.gov (United States)

    Aggression is a challenge when pigs are kept in groups. Sows fight at mixing when space is limited but this project sought to determine the amount and type of aggression observed when unacquainted Berkshire sows were mixed in pairs or in two established sub-groups of three in outdoor paddocks. Treat...

  11. Ethnic categorization of immigrants : The role of prejudice, perceived acculturation strategies and group size

    NARCIS (Netherlands)

    Kosica, Ankica; Phalet, Karen

    2006-01-01

    People usually perceive immigrants from different national origins as similar to each other, and thus as belonging to a limited number of ethnic out-groups [Sporer, S. L. (2001a). Recognizing faces of other ethnic groups: An integration of theories. Psychology, Public and Law, 7, 36–97, Sporer, S.

  12. Effects of group size and expectancy of reward on social loafing ...

    African Journals Online (AJOL)

    ... years (mean age = 14.53). Results indicated that performance was significantly poorer in the group condition than in the alone condition (p. <05); and reward significantly attenuated social loafing effect in the group condition (p. <05). These observations were discussed in relation to the prevailing challenge in team work.

  13. Relationship between group size and feeding success of cattle egrets (Bubulcus ibis in the central Free State

    Directory of Open Access Journals (Sweden)

    Hennie Butler

    2008-09-01

    Full Text Available Regardless of habitat or time of day, cattle egrets feeding independently of hosts generally occurring larger groups than those feeding in close association with ungulates. The average group size of three individuals feeding in association with hosts stays remarkably constant with regard to divergent situations. Based on the type of habitat and the grazing speed of the host concerned, cattle egrets achieve the highest feeding success (number of prey items with the least energy inputs (number of paces in association with cattle, and to a lesser extent with the closely related buffalo. Compared to solitary birds, cattle egrets feeding in groups experience without exceptional higher feeding success. Results of feeding experiments, as well as the exceptional occurrence of so-called feeding lines, confirm the phenomenon that the feeding success of cattle egrets correlates closely with the size of the feeding group.

  14. Peer groups splitting in Croatian EQA scheme: a trade-off between homogeneity and sample size number.

    Science.gov (United States)

    Vlašić Tanasković, Jelena; Coucke, Wim; Leniček Krleža, Jasna; Vuković Rodriguez, Jadranka

    2017-03-01

    Laboratory evaluation through external quality assessment (EQA) schemes is often performed as 'peer group' comparison under the assumption that matrix effects influence the comparisons between results of different methods, for analytes where no commutable materials with reference value assignment are available. With EQA schemes that are not large but have many available instruments and reagent options for same analyte, homogenous peer groups must be created with adequate number of results to enable satisfactory statistical evaluation. We proposed a multivariate analysis of variance (MANOVA)-based test to evaluate heterogeneity of peer groups within the Croatian EQA biochemistry scheme and identify groups where further splitting might improve laboratory evaluation. EQA biochemistry results were divided according to instruments used per analyte and the MANOVA test was used to verify statistically significant differences between subgroups. The number of samples was determined by sample size calculation ensuring a power of 90% and allowing the false flagging rate to increase not more than 5%. When statistically significant differences between subgroups were found, clear improvement of laboratory evaluation was assessed before splitting groups. After evaluating 29 peer groups, we found strong evidence for further splitting of six groups. Overall improvement of 6% reported results were observed, with the percentage being as high as 27.4% for one particular method. Defining maximal allowable differences between subgroups based on flagging rate change, followed by sample size planning and MANOVA, identifies heterogeneous peer groups where further splitting improves laboratory evaluation and enables continuous monitoring for peer group heterogeneity within EQA schemes.

  15. Beyond one-size-fits-all: Tailoring diversity approaches to the representation of social groups.

    Science.gov (United States)

    Apfelbaum, Evan P; Stephens, Nicole M; Reagans, Ray E

    2016-10-01

    When and why do organizational diversity approaches that highlight the importance of social group differences (vs. equality) help stigmatized groups succeed? We theorize that social group members' numerical representation in an organization, compared with the majority group, influences concerns about their distinctiveness, and consequently, whether diversity approaches are effective. We combine laboratory and field methods to evaluate this theory in a professional setting, in which White women are moderately represented and Black individuals are represented in very small numbers. We expect that focusing on differences (vs. equality) will lead to greater performance and persistence among White women, yet less among Black individuals. First, we demonstrate that Black individuals report greater representation-based concerns than White women (Study 1). Next, we observe that tailoring diversity approaches to these concerns yields greater performance and persistence (Studies 2 and 3). We then manipulate social groups' perceived representation and find that highlighting differences (vs. equality) is more effective when groups' representation is moderate, but less effective when groups' representation is very low (Study 4). Finally, we content-code the diversity statements of 151 major U.S. law firms and find that firms that emphasize differences have lower attrition rates among White women, whereas firms that emphasize equality have lower attrition rates among racial minorities (Study 5). (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. 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.

  17. Attitudes, Behaviors, and Effectiveness of Black and White Leaders of Simulated Problem Solving Groups of Varying Size and Racial Composition.

    Science.gov (United States)

    Hill, Walter A.; Allen, William R.

    A field experiment was used to investigate the effects, if any, of changing group size and racial composition on the attitudes, behaviors, and effectiveness of black and white leaders. Subjects were 288 naval recruits, half black and half white, performing two tasks which were watched by a pair of racially mixed observers through a one-way mirror.…

  18. 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...

  19. The Effect of Computer-Assisted Cooperative Learning Methods and Group Size on the EFL Learners' Achievement in Communication Skills

    Science.gov (United States)

    AbuSeileek, Ali Farhan

    2012-01-01

    This study explored the effect of cooperative learning small group size and two different instructional modes (positive interdependence vs. individual accountability) on English as a Foreign Language (EFL) undergraduate learners' communication skills (speaking and writing) achievement in computer-based environments. The study also examined the…

  20. 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

    -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...

  1. Dietary assessment in minority ethnic groups: a systematic review of instruments for portion-size estimation in the United Kingdom.

    Science.gov (United States)

    Almiron-Roig, Eva; Aitken, Amanda; Galloway, Catherine; Ellahi, Basma

    2017-03-01

    Dietary assessment in minority ethnic groups is critical for surveillance programs and for implementing effective interventions. A major challenge is the accurate estimation of portion sizes for traditional foods and dishes. The aim of this systematic review was to assess records published up to 2014 describing a portion-size estimation element (PSEE) applicable to the dietary assessment of UK-residing ethnic minorities. Electronic databases, internet sites, and theses repositories were searched, generating 5683 titles, from which 57 eligible full-text records were reviewed. Forty-two publications about minority ethnic groups (n = 20) or autochthonous populations (n = 22) were included. The most common PSEEs (47%) were combination tools (eg, food models and portion-size lists), followed by portion-size lists in questionnaires/guides (19%) and image-based and volumetric tools (17% each). Only 17% of PSEEs had been validated against weighed data. When developing ethnic-specific dietary assessment tools, it is important to consider customary portion sizes by sex and age, traditional household utensil usage, and population literacy levels. Combining multiple PSEEs may increase accuracy, but such methods require validation. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute.

  2. David against Goliath? Group size and bystander effects in virtual knowledge sharing

    NARCIS (Netherlands)

    Voelpel, S.C.; Eckhoff, R.A.; Förster, J.

    2008-01-01

    Knowledge management has been identified as a key factor for sustaining a competitive advantage in today’s corporate world. A fundamental aspect of knowledge management in a global economy is the sharing of information in online groups. Most researchers and practitioners have so far assumed that a

  3. The effects of group size on aggression when mixing unacquainted sows in indoor pens

    Science.gov (United States)

    As the US swine industry moves towards group housing sows, it is important to increase our understanding of aggression. Sows fight at mixing and this project sought to determine the amount and type of aggression observed when unacquainted York × Landrace sows were mixed in pairs or in two establishe...

  4. Territory and group sizes in Eurasian beavers (Castor fiber): echoes of settlement and reproduction?

    NARCIS (Netherlands)

    Campbell, R.D.; Rosell, F.; Nolet, B.A.; Dijkstra, V.A.A.

    2005-01-01

    According to current theories of territoriality, an animal is expected to defend the smallest area that can provide resources for maximisation of reproduction, known as the economically defendable area. In group territorial species however, the strategies behind resource defence are likely to be

  5. Effect of Parasitoid: Host Ratio and Group Size on Fitness of Spathius galinae (Hymenoptera: Braconidae): Implications for Mass-Rearing.

    Science.gov (United States)

    Watt, Timothy J; Duan, Jian J; Tallamy, Douglas W; Hough-Goldstein, Judith

    2015-06-01

    Producing insect natural enemies in laboratories or insectaries for biological pest control is often expensive, and developing cost-effective rearing techniques is a goal of many biological control programs. Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a newly described ectoparasitoid of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is currently being evaluated for environmental introduction in the United States to provide biological control of this invasive pest. To improve mass-rearing outcomes for S. galinae, we investigated the effects of parasitoid: host ratio and parasitoid and host group size (density) on parasitoid fitness. Our results showed that when 1 emerald ash borer larva was exposed to 1, 2, 4, or 8 female parasitoids, parasitism rate was positively associated with increasing parasitoid: host ratio, while brood size, sex ratio, and fitness estimates of progeny were not affected. When a constant 1:1 parasitoid: host ratio was used, but group size varied from 1 female parasitoid and 1 host, 5 parasitoids and 5 hosts, 10 of each, and 20 of each in same size rearing cages, parasitism rates were highest when at least 5 females were exposed to 5 host larvae. Moreover, the number of progeny produced per female parasitoid was greatest when group size was 10 parasitoids and 10 hosts. These findings demonstrate that S. galinae may be reared most efficiently in moderately high-density groups (10 parasitoids and hosts) and with a 1:1 parasitoid: host ratio. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Effect of group size and health status on behavior and feed intake of multiparous dairy cows in early lactation

    DEFF Research Database (Denmark)

    Jensen, Margit Bak; Proudfoot, Kathryn L.

    2017-01-01

    Dairy cows in early lactation are often housed in a large group, where they may have to compete for access to feed and space. However, a cow's ability to compete may be impaired due to production disease, and housing in a small group with minimal competition may be beneficial for cow welfare....... The aim of this study was to investigate the effect of group size and health on social and feeding behavior of cows during the first 3 d after introduction to a new group. Data included 54 multiparous Holstein-Friesian cows that were moved from an individual maternity pen and individually joined...... an existing group pen for 6 (N6) or 24 cows (N24) on d 4 after calving. Cows were considered sick if they were diagnosed with and treated for milk fever, mastitis, or retained placenta, diagnosed with subclinical ketosis or metritis within 3 d of calving, or were diagnosed and treated for any other infection...

  7. Language Delays in Toddlers: Information for Parents

    Science.gov (United States)

    ... Stages Listen Español Text Size Email Print Share Language Delays in Toddlers: Information for Parents Page Content ... situation or repeats scripts from TV Delays in language Delays in language are the most common types ...

  8. Seasonal Variation in Group Size Is Related to Seasonal Variation in Neuropeptide Receptor Density.

    Science.gov (United States)

    Wilson, Leah C; Goodson, James L; Kingsbury, Marcy A

    2016-01-01

    In many species, seasonal variation in grouping behavior is widespread, with shifts towards territoriality in the breeding season and grouping in the winter. Compared to the hormonal and neural mechanisms of seasonal territorial aggression, the mechanisms that promote seasonal grouping have received little attention. We collected brains in spring and winter from wild-caught males of two species of emberizid sparrows that seasonally flock (the field sparrow, Spizella pusilla, and the dark-eyed junco, Junco hyemalis) and two species that do not seasonally flock (the song sparrow, Melospiza melodia, and the eastern towhee, Pipilo erythrophthalmus). We used receptor autoradiography to quantify seasonal plasticity in available binding sites for three neuropeptides known to influence social behavior. We examined binding sites for 125I-vasoactive intestinal polypeptide (VIP), 125I-sauvagine (SG, a ligand for corticotropin-releasing hormone receptors) and 125I-ornithine vasotocin analog (OVTA, a ligand for the VT3 nonapeptide). For all species and ligands, brain areas that exhibited a seasonal pattern in binding density were characterized by a winter increase. Compared to nonflocking species, seasonally flocking species showed different binding patterns in multiple brain areas. Furthermore, we found that winter flocking was associated with elevated winter 125I-VIP binding density in the medial amygdala, as well as 125I-VIP and 125I-OVTA binding density in the rostral arcopallium. While the functional significance of the avian rostral arcopallium is unclear, it may incorporate parts of the pallial amygdala. Our results point to this previously undescribed area as a likely hot spot of social modulation. © 2016 S. Karger AG, Basel.

  9. Group size effects in two repeated game models of a global climate agreement

    Energy Technology Data Exchange (ETDEWEB)

    Helland, Leif

    2002-07-01

    What levels of total abatement can one hope for in a global climate agreement. Some potential answers to this question are provided by game theory. This working paper contains a critical discussion of two (prominent) game ,models that answer the question quite pessimistically. Both models take the n-person, infinitely repeated prisoner's dilemma game as their point of departure. The first model is a full information model and utilises the motion of a weakly re negotiation proof equilibrium. This results in the (maybe counterintuitive) prediction that an agreement that can provide high utility to the group will attract less total abatement than an agreement that can only provide low utility to the group. The second model assumes imperfect public information and utilises the notion of a trigger level equilibrium. This results in the (more intuitive) prediction that the level of total abatements will increase with improved verification techniques for a given player set. Still the level of total abatements decrease with an increasing player set for a given verification technique. Empirical implications of the two models are identified and it is argued that one should confront these with experimentally generated data in order to discriminate between the models. One reason for this is that historical data on abatement efforts in a global climate agreement do not exist since no such agreement has entered into force yet. (Author)

  10. Group size effects in two repeated game models of a global climate agreement

    International Nuclear Information System (INIS)

    Helland, Leif

    2002-01-01

    What levels of total abatement can one hope for in a global climate agreement. Some potential answers to this question are provided by game theory. This working paper contains a critical discussion of two (prominent) game ,models that answer the question quite pessimistically. Both models take the n-person, infinitely repeated prisoner's dilemma game as their point of departure. The first model is a full information model and utilises the motion of a weakly re negotiation proof equilibrium. This results in the (maybe counterintuitive) prediction that an agreement that can provide high utility to the group will attract less total abatement than an agreement that can only provide low utility to the group. The second model assumes imperfect public information and utilises the notion of a trigger level equilibrium. This results in the (more intuitive) prediction that the level of total abatements will increase with improved verification techniques for a given player set. Still the level of total abatements decrease with an increasing player set for a given verification technique. Empirical implications of the two models are identified and it is argued that one should confront these with experimentally generated data in order to discriminate between the models. One reason for this is that historical data on abatement efforts in a global climate agreement do not exist since no such agreement has entered into force yet. (Author)

  11. The impact of size of cooperative group on achievement, social support, and self-esteem.

    Science.gov (United States)

    Bertucci, Andrea; Conte, Stella; Johnson, David W; Johnson, Roger T

    2010-01-01

    The effect of cooperative learning in pairs and groups of 4 and in individualistic learning were compared on achievement, social support, and self-esteem. Sixty-two Italian 7th-grade students with no previous experience with cooperative learning were assigned to conditions on a stratified random basis controlling for ability, gender, and self-esteem. Students participated in 1 instructional unit for 90 min for 6 instructional days during a period of about 6 weeks. The results indicate that cooperative learning in pairs and 4s promoted higher achievement and greater academic support from peers than did individualistic learning. Students working in pairs developed a higher level of social self-esteem than did students learning in the other conditions.

  12. 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.

  13. 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).

  14. Why Patients Delay Their First Contact with Health Services After Stroke? A Qualitative Focus Group-Based Study.

    Directory of Open Access Journals (Sweden)

    Alice Le Bonniec

    Full Text Available Despite national and local French information campaigns, when acute stroke occurs, waiting times before calling mobile emergency medical services (EMS to receive appropriate treatment (i.e. thrombolysis and decrease the risk of physical disability, remain long. We aimed to identify the representations of stroke in the general population and to determine barriers to and facilitators for rapidly contacting EMS.We conducted a qualitative study among the general population with 10 focus groups, 5 comprising employed people (N = 29 and 5 comprising retirees (N = 32. The themes discussed were general knowledge about stroke and its risk factors, symptoms, appropriate management and the awareness that stroke is an emergency issue.In addition to a lack of knowledge about stroke, other barriers to rapidly contacting the EMS were difficulties in recognizing symptoms and understanding that these symptoms constitute an emergency. Furthermore, when faced with stroke, a feeling of inevitability and fatalism about the consequences of a stroke was highlighted. Participants were unaware of the existence of an effective treatment and they mistrusted medical competences. Finally, we found a strong presence and participant appreciation of common knowledge, resulting in the sharing of experiences of stroke. This could partly compensate for the lack of specific knowledge about symptom recognition and appropriate action.Information campaigns should not only inform the public about stroke symptoms in order to ensure people act appropriately, but should also focus on increasing public awareness about the fact that an effective treatment exists.

  15. One size fits all? Policy instruments should fit the segments of target groups

    International Nuclear Information System (INIS)

    Egmond, Cees; Lulofs, Kris

    2005-01-01

    In order to meet the Kyoto CO 2 reduction targets, technical innovations in the field of energy-efficiency must be diffused more rapidly and on a larger market scale. Markets develop gradually however, especially if innovations are involved. Diffusion starts with the innovators and early adopters (the early market), followed by the mainstream market (the early and late majority), and ends with the laggards. The actors in these markets differ in their willingness to adopt innovations: the early market actors have a visionary attitude, and the mainstream actors are more pragmatic. In order to choose policy instruments that will most effectively influence these two markets within the target group of housing association, we addressed the following two questions. (1) What are the differences between the early and mainstream markets actors from a behavioural change point of view, and (2) in what way do existing policy instruments differ in influencing the behaviour of these actors? We analysed early market and mainstream decision-making behaviour, and how the active ingredients in policy instruments specifically target the characteristics of the two markets. Mainstream instruments should intervene as early as possible in the decision-making process and emphasise communication about advantages such as comfort and quality in addition to money and energy savings, and present energy conservation as a solution to an actual problem. Instead of bureaucratic subsidy systems for the mainstream, the motto should be 'cash on the barrelhead'. Early market actors are highly internally motivated, implying that early market interventions have to be challenging and facilitating

  16. One size fits all? Policy instruments should fit the segments of target groups

    International Nuclear Information System (INIS)

    Egmond, C.; Jonkers, R.; Kok, G.

    2006-01-01

    In order to meet the Kyoto CO 2 reduction targets, technical innovations in the field of energy-efficiency must diffuse more rapidly into a larger market. However, markets develop gradually, especially if innovations are involved. Diffusion starts with the early market (innovators and early adopters), followed by the mainstream market (the early and late majority), and ends with the laggards. The actors in these markets differ in their willingness to adopt innovations; the early market actors have a visionary attitude, and the mainstream market actors are more pragmatic. In order to choose policy instruments that will most effectively influence these two markets within the target group of housing association, we addressed the following two questions. (1) What are the differences between the early and mainstream market actors from a behavioural-change point of view? (2) In what way do existing policy instruments differ in influencing the behaviour of these actors? We analyzed early market and mainstream decision-making behaviours, and how the active ingredients in policy instruments specifically target the characteristics of the two markets. Mainstream instruments should intervene as early as possible in the decision-making process and emphasize communication about advantages such as comfort and quality in addition to money and energy savings. Furthermore, they should present energy conservation as a solution to an actual problem. Instead of bureaucratic subsidy systems for the mainstream, the motto should be 'cash on the barrel-head'. Early market actors are highly internally motivated, implying that early market interventions have to be challenging and facilitating

  17. Photoluminescence effects of graphitic core size and surface functional groups in carbon dots: COO− induced red-shift emission

    KAUST Repository

    Hola, Katerina

    2014-04-01

    We present a simple molecular approach to control the lipophilic/ hydrophilic nature of photoluminescent carbon dots (CDs) based on pyrolysis of alkyl gallate precursors. Depending on the gallic acid derivative used, CDs with different alkyl groups (methyl, propyl, lauryl) on the surface can be obtained by isothermal heating at 270 C. This precursor-derived approach allows not only the control of lipophilicity but also the length of the particular alkyl chain enables the control over both the size and photoluminescence (PL) of the prepared CDs. Moreover, the alkyl chains on the CDs surface can be readily converted to carboxylate groups via a mild base hydrolysis to obtain water dispersible CDs with a record biocompatibility. The observed differences in PL properties of CDs and time-resolved PL data, including contributions from carbogenic cores and surface functional group, are rationalized and discussed in detail using time-dependent density functional theory (TD-DFT) calculations. © 2013 Elsevier Ltd. All rights reserved.

  18. Comparison of infarct size changes with delayed contrast-enhanced magnetic resonance imaging and electrocardiogram QRS scoring during the 6 months after acutely reperfused myocardial infarction

    DEFF Research Database (Denmark)

    Bang, L.E.; Ripa, R.S.; Grande, P.

    2008-01-01

    INTRODUCTION: Magnetic resonance imaging using the delayed contrast-enhanced (DE-MRI) method can be used for characterizing and quantifying myocardial infarction (MI). Electrocardiogram (ECG) score after the acute phase of MI can be used to estimate the portion of left ventricular myocardium...

  19. Delayed administration of neural stem cells after hypoxia-ischemia reduces sensorimotor deficits, cerebral lesion size, and neuroinflammation in neonatal mice

    NARCIS (Netherlands)

    Braccioli, Luca; Heijnen, Cobi J.; Coffer, Paul J.; Nijboer, Cora H.A.

    2017-01-01

    Background Hypoxic-ischemic (HI) encephalopathy causes mortality and severe morbidity in neonates. Treatments with a therapeutic window >6 hours are currently not available. Here we explored whether delayed transplantation of allogenic neural stem cells (NSCs) at 10 days after HI could be a tool to

  20. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  1. 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

    four batches in a 2×2 factorial design in order to test the influence of social mixing (presence or absence of social mixing at relocation) and group size (15 and 30 animals). Animals were able to socialise with piglets from other litters during the lactation period, and were all mixed across litters......Alternatives to surgical castration are needed, due to stress and pain caused by castration of male pigs. One alternative is production of entire male pigs. However, changed behaviour of entire males compared with castrated males might adversely affect the welfare of entire males and changes...... frequency (Panimals as compared...

  2. Unit-level voluntary turnover rates and customer service quality: implications of group cohesiveness, newcomer concentration, and size.

    Science.gov (United States)

    Hausknecht, John P; Trevor, Charlie O; Howard, Michael J

    2009-07-01

    Despite substantial growth in the service industry and emerging work on turnover consequences, little research examines how unit-level turnover rates affect essential customer-related outcomes. The authors propose an operational disruption framework to explain why voluntary turnover impairs customers' service quality perceptions. On the basis of a sample of 75 work units and data from 5,631 employee surveys, 59,602 customer surveys, and organizational records, results indicate that unit-level voluntary turnover rates are negatively related to service quality perceptions. The authors also examine potential boundary conditions related to the disruption framework. Of 3 moderators studied (group cohesiveness, group size, and newcomer concentration), results show that turnover's negative effects on service quality are more pronounced in larger units and in those with a greater concentration of newcomers.

  3. Occupational Safety and Health Conditions Aboard Small- and Medium-Size Fishing Vessels: Differences among Age Groups.

    Science.gov (United States)

    Zytoon, Mohamed A; Basahel, Abdulrahman M

    2017-02-24

    Although marine fishing is one of the most hazardous occupations, research on the occupational safety and health (OSH) conditions aboard marine fishing vessels is scarce. For instance, little is known about the working conditions of vulnerable groups such as young and aging fishermen. The objective of the current paper is to study the OSH conditions of young and aging fishermen compared to middle-aged fishermen in the small- and medium-size (SM) marine fishing sector. A cross-sectional study was designed, and 686 fishermen working aboard SM fishing vessels were interviewed to collect information about their safety and health. The associations of physical and psychosocial work conditions with safety and health outcomes, e.g., injuries, illnesses and job satisfaction, are presented. The results of the current study can be utilized in the design of effective accident prevention and OSH training programs for the three age groups and in the regulation of working conditions aboard fishing vessels.

  4. Does home range use explain the relationship between group size and parasitism? A test with two sympatric species of howler monkeys.

    Science.gov (United States)

    González-Hernández, Milagros; Dias, Pedro Américo D; Romero-Salas, Dora; Canales-Espinosa, Domingo

    2011-07-01

    Group size is related to parasite infections in primates. This relationship probably reflects the fact that group size is associated with body contact between group members and with contact with contaminated items in the environment. The latter is highly associated with range use. In the present study we hypothesized that if infection by directly transmitted parasites (DTP) is mainly determined by the exposure of individuals to parasites that accumulate in the environment, and group size correlates negatively with the intensity of home range use, then smaller groups should be more infected by DTP. Additionally, groups that share a higher proportion of their home range with other groups should be more infected. To test our hypothesis we observed and collected fecal samples of two groups of Alouatta palliata (large group size) and two groups of A. pigra (small group size) that live sympatrically in a forest fragment located in Macuspana (Mexico). Group size was positively correlated with range area size and negatively correlated with the intensity of home range use. Range use variables were not related to either DTP prevalence or load. However, there were significant differences in DTP loads between groups, which were positively correlated with group size. Our results suggest that the intensity of home range use is a poor predictor of DTP infection parameters in groups with marked differences in size. Therefore, it is possible that the individual or combined effects of other ecological (e.g., microclimate), social (e.g., contact rate), or physiological (e.g., immune function) factors are more important in the dynamics of DTP in free-ranging primates.

  5. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition ...... mineral density) and psychological (e.g., low self-esteem) and underline the importance of careful clinical assessment of the patients....

  6. Optimal pricing and lot-sizing policies for an economic production quantity model with non-instantaneous deteriorating items, permissible delay in payments, customer returns, and inflation

    DEFF Research Database (Denmark)

    Ghoreishi, Maryam; Mirzazadeh, Abolfazl; Nakhai Kamalabadi, Isa

    2014-01-01

    . The effects of time value of money are studied using the Discounted Cash Flow approach. The main objective is to determine the optimal selling price, the optimal length of the production period, and the optimal length of inventory cycle simultaneously such that the present value of total profit is maximized....... An efficient algorithm is presented to find the optimal solution of the developed model. Finally, a numerical example is extracted to solve the presented inventory model using our proposed algorithm, and the effects of the customer returns, inflation, and delay in payments are also discussed....

  7. Population Balance Modeling of Polydispersed Bubbly Flow in Continuous-Casting Using Multiple-Size-Group Approach

    Science.gov (United States)

    Liu, Zhongqiu; Li, Linmin; Qi, Fengsheng; Li, Baokuan; Jiang, Maofa; Tsukihashi, Fumitaka

    2015-02-01

    A population balance model based on the multiple-size-group (MUSIG) approach has been developed to investigate the polydispersed bubbly flow inside the slab continuous-casting mold and bubble behavior including volume fraction, breakup, coalescence, and size distribution. The Eulerian-Eulerian approach is used to describe the equations of motion of the two-phase flow. All the non-drag forces (lift force, virtual mass force, wall lubrication force, and turbulent dispersion force) and drag force are incorporated in this model. Sato and Sekiguchi model is used to account for the bubble-induced turbulence. Luo and Svendsen model and Prince and Blanch model are used to describe the bubbles breakup and coalescence behavior, respectively. A 1/4th water model of the slab continuous-casting mold was applied to investigate the distribution and size of bubbles by injecting air through a circumferential inlet chamber which was made of the specially-coated samples of mullite porous brick, which is used for the actual upper nozzle. Against experimental data, numerical results showed good agreement for the gas volume fraction and local bubble Sauter mean diameter. The bubble Sauter mean diameter in the upper recirculation zone decreases with increasing water flow rate and increases with increasing gas flow rate. The distribution of bubble Sauter mean diameter along the width direction of the upper mold increases first, and then gradually decreases from the SEN to the narrow wall. Close agreements between the predictions and measurements demonstrate the capability of the MUSIG model in modeling bubbly flow inside the continuous-casting mold.

  8. Hispanic Americans Baseline Alcohol Survey (HABLAS): effects of container size adjustments on estimates of alcohol consumption across Hispanic national groups.

    Science.gov (United States)

    Caetano, Raul; Mills, Britain A; Harris, T Robert

    2012-01-01

    This study was conducted to examine discrepancies in alcohol consumption estimates between a self-reported standard quantity-frequency measure and an adjusted version based on respondents' typically used container size. Using a multistage cluster sample design, 5,224 Hispanic individuals 18 years of age and older were selected from the household population in five metropolitan areas of the United States: Miami, New York, Philadelphia, Houston, and Los Angeles. The survey-weighted response rate was 76%. Personal interviews lasting an average of 1 hour were conducted in respondents' homes in either English or Spanish. The overall effect of container adjustment was to increase estimates of ethanol consumption by 68% for women (range across Hispanic groups: 17%-99%) and 30% for men (range: 14%-42%). With the exception of female Cuban American, Mexican American, and South/Central American beer drinkers and male Cuban American wine drinkers, all percentage differences between unadjusted and container-adjusted estimates were positive. Second, container adjustments produced the largest change for volume of distilled spirits, followed by wine and beer. Container size adjustments generally produced larger percentage increases in consumption estimates for the higher volume drinkers, especially the upper tertile of female drinkers. Self-reported alcohol consumption based on standard drinks underreports consumption when compared with reports based on the amount of alcohol poured into commonly used containers.

  9. Third parties, violence, and conflict resolution: the role of group size and collective action in the microregulation of violence.

    Science.gov (United States)

    Levine, Mark; Taylor, Paul J; Best, Rachel

    2011-03-01

    Although researchers know much about the causes of aggression, they know surprisingly little about how aggression leads to violence or how violence is controlled. To explore the microregulation of violence, we conducted a systematic behavioral analysis of footage from closed-circuit television surveillance of public spaces. Using 42 incidents involving 312 people, we compared aggressive incidents that ended in violence with those that did not. Behaviors of antagonists and third parties were coded as either escalating or conciliatory acts. Results showed that third parties were more likely to take conciliatory actions than to escalate violence and that this tendency increased as group size increased. This analysis revealed a pattern of third-party behaviors that prevent aggression from becoming violent and showed that conciliatory behaviors are more successful when carried out by multiple third parties than when carried out by one person. We conclude by emphasizing the importance of collective third-party dynamics in understanding conflict resolution.

  10. Effective porosity and pore-throat sizes of Conasauga Group mudrock: Application, test and evaluation of petrophysical techniques

    International Nuclear Information System (INIS)

    Dorsch, J.; Katsube, T.J.; Sanford, W.E.; Univ. of Tennessee, Knoxville, TN; Dugan, B.E.; Tourkow, L.M.

    1996-04-01

    Effective porosity (specifically referring to the interconnected pore space) was recently recognized as being essential in determining the effectiveness and extent of matrix diffusion as a transport mechanism within fractured low-permeability rock formations. The research presented in this report was performed to test the applicability of several petrophysical techniques for the determination of effective porosity of fine-grained siliciclastic rocks. In addition, the aim was to gather quantitative data on the effective porosity of Conasauga Group mudrock from the Oak Ridge Reservation (ORR). The quantitative data reported here include not only effective porosities based on diverse measurement techniques, but also data on the sizes of pore throats and their distribution, and specimen bulk and grain densities. The petrophysical techniques employed include the immersion-saturation method, mercury and helium porosimetry, and the radial diffusion-cell method

  11. 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.

  12. Low Group Delay Dispersion Optical Coating for Broad Bandwidth High Reflection at 45° Incidence, P Polarization of Femtosecond Pulses with 900 nm Center Wavelength

    Directory of Open Access Journals (Sweden)

    John C. Bellum

    2016-03-01

    Full Text Available We describe an optical coating design suitable for broad bandwidth high reflection (BBHR at 45° angle of incidence (AOI, P polarization (Ppol of femtosecond (fs laser pulses whose wavelengths range from 800 to 1000 nm. Our design process is guided by quarter-wave HR coating properties. The design must afford low group delay dispersion (GDD for reflected light over the broad, 200 nm bandwidth in order to minimize temporal broadening of the fs pulses due to dispersive alteration of relative phases between their frequency components. The design should also be favorable to high laser-induced damage threshold (LIDT. We base the coating on TiO2/SiO2 layer pairs produced by means of e-beam evaporation with ion-assisted deposition, and use OptiLayer Thin Film Software to explore designs starting with TiO2/SiO2 layers having thicknesses in a reverse chirped arrangement. This approach led to a design with R > 99% from 800 to 1000 nm and GDD < 20 fs2 from 843 to 949 nm (45° AOI, Ppol. The design’s GDD behaves in a smooth way, suitable for GDD compensation techniques, and its electric field intensities show promise for high LIDTs. Reflectivity and GDD measurements for the initial test coating indicate good performance of the BBHR design. Subsequent coating runs with improved process calibration produced two coatings whose HR bands satisfactorily meet the design goals. For the sake of completeness, we summarize our previously reported transmission spectra and LIDT test results with 800 ps, 8 ps and 675 fs pulses for these two coatings, and present a table of the LIDT results we have for all of our TiO2/SiO2 BBHR coatings, showing the trends with test laser pulse duration from the ns to sub-ps regimes.

  13. Delayed Ejaculation

    Science.gov (United States)

    ... of stress Delayed ejaculation Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  14. Delayed Ejaculation

    Science.gov (United States)

    ... the penis Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication or other concerns Anxiety about performance Poor body image Cultural or religious taboos Differences between the reality ...

  15. Effects of group-size-floor space allowance during the nursery phase of production on growth, physiology, and hematology in replacement gilts.

    Science.gov (United States)

    Callahan, S R; Cross, A J; DeDecker, A E; Lindemann, M D; Estienne, M J

    2017-01-01

    The objective was to determine effects of nursery group-size-floor space allowance on growth, physiology, and hematology of replacement gilts. A 3 × 3 factorial arrangement of treatments was used wherein gilts classified as large, medium, or small ( = 2537; BW = 5.6 ± 0.6 kg) from 13 groups of weaned pigs were placed in pens of 14, 11, or 8 pigs resulting in floor space allowances of 0.15, 0.19, or 0.27 m/pig, respectively. Pigs were weighed on d 0 (weaning) and d 46 (exit from nursery). The ADG was affected by group-size-floor space allowance × pig size ( = 0.04). Large- and medium-size gilts allowed the most floor space had greater ( gilts allowed the least floor space but for small size gilts there was no effect ( > 0.05) of group size-floor space allowance. Mortality in the nursery was not affected ( > 0.05) by treatment, size, or treatment × size and overall was approximately 2.1%. Complete blood counts and blood chemistry analyses were performed on samples collected at d 6 and 43 from a subsample of gilts ( = 18/group-size-floor space allowance) within a single group. The concentration ( gilts allowed 0.15 m floor space (effects of treatment). Blood calcium was affected by treatment ( = 0.02) and concentrations for gilts allowed the greatest and intermediate amounts of floor space were greater ( gilts allowed the least floor space. Serum concentrations of cortisol were not affected by treatment × day ( = 0.27). Cortisol concentrations increased from d 6 to d 43 in all groups and were affected by day ( gilts displaying increased ADG. Further study will determine if these effects influence lifetime reproductive capacity and sow longevity.

  16. The Impact of Satellite Time Group Delay and Inter-Frequency Differential Code Bias Corrections on Multi-GNSS Combined Positioning.

    Science.gov (United States)

    Ge, Yulong; Zhou, Feng; Sun, Baoqi; Wang, Shengli; Shi, Bo

    2017-03-16

    We present quad-constellation (namely, GPS, GLONASS, BeiDou and Galileo) time group delay (TGD) and differential code bias (DCB) correction models to fully exploit the code observations of all the four global navigation satellite systems (GNSSs) for navigation and positioning. The relationship between TGDs and DCBs for multi-GNSS is clearly figured out, and the equivalence of TGD and DCB correction models combining theory with practice is demonstrated. Meanwhile, the TGD/DCB correction models have been extended to various standard point positioning (SPP) and precise point positioning (PPP) scenarios in a multi-GNSS and multi-frequency context. To evaluate the effectiveness and practicability of broadcast TGDs in the navigation message and DCBs provided by the Multi-GNSS Experiment (MGEX), both single-frequency GNSS ionosphere-corrected SPP and dual-frequency GNSS ionosphere-free SPP/PPP tests are carried out with quad-constellation signals. Furthermore, the author investigates the influence of differential code biases on GNSS positioning estimates. The experiments show that multi-constellation combination SPP performs better after DCB/TGD correction, for example, for GPS-only b1-based SPP, the positioning accuracies can be improved by 25.0%, 30.6% and 26.7%, respectively, in the N, E, and U components, after the differential code biases correction, while GPS/GLONASS/BDS b1-based SPP can be improved by 16.1%, 26.1% and 9.9%. For GPS/BDS/Galileo the 3rd frequency based SPP, the positioning accuracies are improved by 2.0%, 2.0% and 0.4%, respectively, in the N, E, and U components, after Galileo satellites DCB correction. The accuracy of Galileo-only b1-based SPP are improved about 48.6%, 34.7% and 40.6% with DCB correction, respectively, in the N, E, and U components. The estimates of multi-constellation PPP are subject to different degrees of influence. For multi-constellation combination SPP, the accuracy of single-frequency is slightly better than that of dual

  17. The distributions of the gladiator frogs (Hyla boans group in Colombia, with comments on size variations and sympatry

    Directory of Open Access Journals (Sweden)

    Lynch John Douglas

    2001-12-01

    valley as well as in the Maracaibo Basin and at a few cis-Andean sites, but always below 500 m. Sympatry is relatively common between H. boans and H. rosenbergi but, less common between H. boans and either "H. crepitans" or H. pugnax. Maximal sympatry results in sympatry of H. boans, H. pugnax, and H. rosenbergi - normally no more than two species are sympatric. Sexual dimorphism in size is evident in the smallest species ("H. crepitans " but not in the others. AHexhibit geographic variation in size, perhaps related to the combination ofsympatric species ofthe group.

  18. Markedly Increased High-Mobility Group Box 1 Protein in a Patient with Small-for-Size Syndrome

    Directory of Open Access Journals (Sweden)

    Darren G. Craig

    2014-01-01

    Full Text Available Background. Small-for-size syndrome (SFSS occurs in the presence of insufficient liver mass to maintain normal function after liver transplantation. Murine mortality following 85% hepatectomy can be reduced by the use of soluble receptor for advanced glycation end products (sRAGE to scavenge damage-associated molecular patterns and prevent their engagement with membrane-bound RAGE. Aims. To explore serum levels of sRAGE, high-mobility group box-1 (HMGB1 protein, and other soluble inflammatory mediators in a fatal case of SFSS. Methods. Serum levels of HMGB1, sRAGE, IL-18, and other inflammatory mediators were measured by ELISA in a case of SFSS, and the results were compared with 8 patients with paracetamol-induced acute liver failure (ALF and 6 healthy controls (HC. Results. HMGB1 levels were markedly higher in the SFSS patient (92.1 ng/mL compared with the ALF patients (median (IQR 11.4 (3.7–14.8 ng/mL and HC (1.42 (1.38–1.56 ng/mL. In contrast, sRAGE levels were lower in the SFSS patient (1.88 ng/mL compared with the ALF patients (3.53 (2.66–12.37 ng/mL and were similar to HC levels (1.40 (1.23–1.89 ng/mL. Conclusion. These results suggest an imbalance between pro- and anti-inflammatory innate immune pathways in SFSS. Modulation of the HMGB1-RAGE axis may represent a future therapeutic avenue in this condition.

  19. Multiple Size Group Modeling of Polydispersed Bubbly Flow in the Mold: An Analysis of Turbulence and Interfacial Force Models

    Science.gov (United States)

    Liu, Zhongqiu; Qi, Fengsheng; Li, Baokuan; Jiang, Maofa

    2015-04-01

    An inhomogeneous Multiple Size Group (MUSIG) model based on the Eulerian-Eulerian approach has been developed to describe the polydispersed bubbly flow inside the continuous-casting mold. A laboratory scale mold has been simulated using four different turbulence closure models (modified k - ɛ, RNG k - ɛ, k - ω, and SST) with the purpose of critically comparing their predictions of bubble Sauter mean diameter distribution with previous experimental data. Furthermore, the influences of all the interfacial momentum transfer terms including drag force, lift force, virtual mass force, wall lubrication force, and turbulent dispersion force are investigated. The breakup and coalescence effects of the bubbles are modeled according to the bubble breakup by the impact of turbulent eddies while for bubble coalescence by the random collisions driven by turbulence and wake entrainment. It has been found that the modified k - ɛ model shows better agreement than other models in predicting the bubble Sauter mean diameter profiles. Further, simulations have also been performed to understand the sensitivity of different interfacial forces. The appropriate drag force coefficient, lift force coefficient, virtual mass force coefficient, and turbulent dispersion force coefficient are chosen in accordance with measurements of water model experiments. However, the wall lubrication force does not have much effect on the current polydispersed bubbly flow system. Finally, the MUSIG model is then used to estimate the argon bubble diameter in the molten steel of the mold. The argon bubble Sauter mean diameter generated in molten steel is predicted to be larger than air bubbles in water for the similar conditions.

  20. 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.

  1. 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

  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. Retinal Nerve Fiber Layer Thicknesses in Three Different Optic Nerve Head Size Groups Measured by Cirrus Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Sirel Gür Güngör

    2016-04-01

    Full Text Available Objectives: To compare the retinal nerve fiber layer (RNFL thicknesses in three different optic nerve head (ONH size groups measured by Cirrus spectral domain optical coherence tomography (OCT. Materials and Methods: Between January and March 2013, 253 eyes of 253 healthy subjects were enrolled in this study (mean age: 42.7±7.4 years [28-62 years]; 121 men and 132 women. The patients were divided into 3 groups according to ONH size: 77 patients in the “small ONH” group (ONH area 1.97 mm2. Results: There were significant differences in superior (p=0.008, inferior (p=0.004 and average RNFL thickness (p=0.001 between the small, medium and large ONH groups. Positive correlations between ONH size and inferior/average RNFL thicknesses were significant but very weak (r=0.150, p=0.017 and r=0.157, p=0.013 respectively. Conclusion: RNFL thickness as measured by Cirrus OCT is positively correlated with ONH size and the differences in RNFL thickness were statistically significant between groups. This correlation and difference may be the result of a varying distance between the circular scan and the ONH margin.

  4. Population sizes and group characteristics of Siberian Crane (Leuco-geranus leucogeranus) and Hooded Crane (Grus monacha) in Poyang Lake Wetland.

    Science.gov (United States)

    Shao, Ming-Qin; Guo, Hong; Jiang, Jian-Hong

    2014-09-01

    Both the Siberian Crane (Leucogeranus leucogeranus) and Hooded Crane (Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies. To document the current size of their respective populations and characterize their groups, between October 2012 and April 2013 we undertook fieldwork at four nature reserve areas within the Poyang Lake wetlands. We divided Poyanghu National Nature Reserve (PYH) into the Wucheng (PWC) and Hengfeng areas (PHF), because each are each located in different counties. Our fieldwork showed that the Siberian Crane occurred mainly in PYH (364 in the PHF, 158 in the PWC) and the Nanjishan Wetland National Nature Reserve (NJS, with 200 individuals). The Hooded Crane was mainly distributed in PYH (302 in the PHF and 154 in the PWC). Family groups accounted for more than 50% of the total number of groups among both species, with Hooded Cranes forming more family groups than Siberian Cranes. Typically, these groups were formed of two adults with one offspring (Siberian Crane), and two adults with two offspring (Hooded Crane), with the mean family group size of the Siberian Crane and Hooded Crane being respectively 2.65 ± 0.53 (n=43) and 3.09 ± 0.86 (n=47) individuals per group. The mean collective group size of the Siberian Crane and Hooded Crane included 28.09 ± 24.94 (n=23) and 28.94 ± 27.97 (n=16) individuals per group, respectively, with the proportion of juveniles among Hooded Cranes being more than double that seen among the Siberian Cranes.

  5. A review and re-interpretation of a group-sequential approach to sample size re-estimation in two-stage trials.

    Science.gov (United States)

    Bowden, J; Mander, A

    2014-01-01

    In this paper, we review the adaptive design methodology of Li et al. (Biostatistics 3:277-287) for two-stage trials with mid-trial sample size adjustment. We argue that it is closer in principle to a group sequential design, in spite of its obvious adaptive element. Several extensions are proposed that aim to make it even more attractive and transparent alternative to a standard (fixed sample size) trial for funding bodies to consider. These enable a cap to be put on the maximum sample size and for the trial data to be analysed using standard methods at its conclusion. The regulatory view of trials incorporating unblinded sample size re-estimation is also discussed. © 2014 The Authors. Pharmaceutical Statistics published by John Wiley & Sons, Ltd.

  6. Evidence from a Large Sample on the Effects of Group Size and Decision-Making Time on Performance in a Marketing Simulation Game

    Science.gov (United States)

    Treen, Emily; Atanasova, Christina; Pitt, Leyland; Johnson, Michael

    2016-01-01

    Marketing instructors using simulation games as a way of inducing some realism into a marketing course are faced with many dilemmas. Two important quandaries are the optimal size of groups and how much of the students' time should ideally be devoted to the game. Using evidence from a very large sample of teams playing a simulation game, the study…

  7. Rapid changes in the size of different functional organ and muscle groups during refueling in a long-distance migrating shorebird

    NARCIS (Netherlands)

    Piersma, T; Gudmundsson, GA; Lilliendahl, K; Gudmundsson, Gudmundur A.

    1999-01-01

    The adaptive value of size changes in different organ and muscle groups was studied in red knots (Calidris canutus islandica) in relation to their migration. Birds were sampled on five occasions: at arrival in Iceland in May 1994, two times during subsequent refueling, at departure toward, and on

  8. 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...

  9. Group size and composition of Guiana dolphins (Sotalia guianensis) (Van Bénèden, 1864) in the Paranaguá Estuarine Complex, Brazil.

    Science.gov (United States)

    Santos, M C O; Oshima, J E F; Pacífico, E S; Silva, E

    2010-02-01

    The aim of the present study was to describe the characteristics of Guiana dolphins (S. guianensis) group size and composition in the Paranaguá Estuarine Complex (25 degrees 15'-25 degrees 36' S and 48 degrees 02'-48 degrees 45' W), Paraná State, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature) and group size. An area of around 124 km(2) was surveyed by boat from April 2006 to February 2008 in the following subsets of the estuary: Canal do Superagui (approximately 28 km(2)), Pinheiros bay (approximately 34 km(2)), part of Laranjeiras bay, which included the Guaraqueçaba sub-estuary (approximately 38 km(2)), and part of the Mixture Section of the Paranaguá Estuarine Complex (approximately 24 km(2)). In 45 survey days, a total of 147 hours were spent observing 286 groups of S. guianensis. Groups varied from two individuals to aggregations of up to 90 individuals (mean +/- SD: 11.5 +/- 14.4 individuals). Solitary individuals were seen only on five occasions (1.7% of all observations). Groups with calves (n = 247) represented 86.4% overall and were more common in all sub-areas when compared to groups without calves. Groups without calves were found in all sub-areas and were usually smaller and composed of up to 12 individuals. A usual group composition of 70% of adults and 30% of calves was observed considering all sub-areas and seasons. No correlations were found between group size and water temperature (Spearman's rank test, r = 0.0059, p = 0.9338), transparency (Spearman's rank test, r = 0.0597, p = 0.9333), depth (Spearman's rank test, r = 0.1421, p = 0.4698), and salinity (Spearman's rank test, r = -0.1938, p = 0.0665). While Guiana dolphin groups were seen in the entire surveyed area, group size varied significantly among the three main surveyed sub-areas (Kruskal Wallis, H2,196 = 29.85, p = 0.0000). Groups were larger in Laranjeiras bay and smaller in Canal do

  10. Group size and composition of Guiana dolphins (Sotalia guianensis (Van Bénèden, 1864 in the Paranaguá Estuarine Complex, Brazil

    Directory of Open Access Journals (Sweden)

    MCO. Santos

    Full Text Available The aim of the present study was to describe the characteristics of Guiana dolphins (S. guianensis group size and composition in the Paranaguá Estuarine Complex (25° 15' -25° 36' S and 48° 02'-48° 45' W, Paraná State, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature and group size. An area of around 124 km² was surveyed by boat from April 2006 to February 2008 in the following subsets of the estuary: Canal do Superagui (~28 km², Pinheiros bay (~34 km², part of Laranjeiras bay, which included the Guaraqueçaba sub-estuary (~38 km², and part of the Mixture Section of the Paranaguá Estuarine Complex (~24 km². In 45 survey days, a total of 147 hours were spent observing 286 groups of S. guianensis. Groups varied from two individuals to aggregations of up to 90 individuals (mean ± SD: 11.5 ± 14.4 individuals. Solitary individuals were seen only on five occasions (1.7% of all observations. Groups with calves (n = 247 represented 86.4% overall and were more common in all sub-areas when compared to groups without calves. Groups without calves were found in all sub-areas and were usually smaller and composed of up to 12 individuals. A usual group composition of 70% of adults and 30% of calves was observed considering all sub-areas and seasons. No correlations were found between group size and water temperature (Spearman's rank test, r = 0.0059, p = 0.9338, transparency (Spearman's rank test, r = 0.0597, p = 0.9333, depth (Spearman's rank test, r = 0.1421, p = 0.4698, and salinity (Spearman's rank test, r = -0.1938, p = 0.0665. While Guiana dolphin groups were seen in the entire surveyed area, group size varied significantly among the three main surveyed sub-areas (Kruskal Wallis, H2,196 = 29.85, p = 0.0000. Groups were larger in Laranjeiras bay and smaller in Canal do Superagui. The physical environment, risk of predation, seasonal distribution

  11. 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.

  12. One size does not fit all: HIV testing preferences differ among high-risk groups in Northern Tanzania.

    Science.gov (United States)

    Ostermann, Jan; Njau, Bernard; Mtuy, Tara; Brown, Derek S; Mühlbacher, Axel; Thielman, Nathan

    2015-01-01

    In order to maximize the effectiveness of "Seek, Test, and Treat" strategies for curbing the HIV epidemic, new approaches are needed to increase the uptake of HIV testing services, particularly among high-risk groups. Low HIV testing rates among such groups suggest that current testing services may not align well with the testing preferences of these populations. Female bar workers and male mountain porters have been identified as two important high-risk groups in the Kilimanjaro Region of Tanzania. We used conventional survey methods and a discrete choice experiment (DCE), a preference elicitation method increasingly applied by economists and policy-makers to inform health policy and services, to analyze trade-offs made by individuals and quantify preferences for HIV testing services. Bivariate descriptive statistics were used to analyze differences in survey responses across groups. Compared to 486 randomly selected community members, 162 female bar workers and 194 male Kilimanjaro porters reported 2-3 times as many lifetime sexual partners (p porters preferred testing in venues where antiretroviral therapy was readily available. Both high-risk groups were less averse to traveling longer distances to test compared to their community counterparts. These results expose systematic differences in HIV testing preferences across high-risk populations compared to their community peers. Tailoring testing options to the preferences of high-risk populations should be evaluated as a means of improving uptake of testing in these populations.

  13. Cliff´s Delta Calculator: A non-parametric effect size program for two groups of observations

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2011-05-01

    Full Text Available The Cliff´s Delta statistic is an effect size measure that quantifies the amount of difference between two non-parametric variables beyond p-values interpretation. This measure can be understood as a useful complementary analysis for the corresponding hypothesis testing. During the last two decades the use of effect size measures has been strongly encouraged by methodologists and leading institutions of behavioral sciences. The aim of this contribution is to introduce the Cliff´s Delta Calculator software that performs such analysis and offers some interpretation tips. Differences and similarities with the parametric case are analysed and illustrated. The implementation of this free program is fully described and compared with other calculators. Alternative algorithmic approaches are mathematically analysed and a basic linear algebra proof of its equivalence is formally presented. Two worked examples in cognitive psychology are commented. A visual interpretation of Cliff´s Delta is suggested. Availability, installation and applications of the program are presented and discussed.

  14. Delayed recompression for decompression sickness: retrospective analysis.

    Directory of Open Access Journals (Sweden)

    Amir Hadanny

    Full Text Available Most cases of decompression sickness (DCS occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48 h after surfacing for DCS and second, to evaluate the different treatment protocols.From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48 h for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48 h after surfacing at the same hyperbaric institute.There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07 compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation.Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6.

  15. Effect of group size and health status on behavior and feed intake of multiparous dairy cows in early lactation

    DEFF Research Database (Denmark)

    Jensen, Margit Bak; Proudfoot, Kathryn L.

    2017-01-01

    an existing group pen for 6 (N6) or 24 cows (N24) on d 4 after calving. Cows were considered sick if they were diagnosed with and treated for milk fever, mastitis, or retained placenta, diagnosed with subclinical ketosis or metritis within 3 d of calving, or were diagnosed and treated for any other infection...

  16. Reducing time delay in the thrombolysis of myocardial infarction: an internal quality improvement project. ARIAM Project Group. Analisis del Retraso en Infarto Agudo de Miocardio.

    Science.gov (United States)

    Saturno, P J; Felices, F; Segura, J; Vera, A; Rodriguez, J J

    2000-01-01

    The objectives of this study were to improve thrombolytic therapy in acute myocardial infarction by reducing the "door-to-needle" time in a 285-bed university hospital in Spain. A quality management approach was used involving all the relevant staff. Target standard was set at 35 minutes. Baseline data, intervention effect, and continuous monitoring were analyzed using x control charts. Analysis of baseline data showed a wide out-of-control variation and 72 minutes' average delay. Cause analysis revealed organizational and clinical problems that were subjected to intervention. Postintervention data showed a stable process, with an average of 30 minutes. Continuous monitoring showed further improvement in average time and predictable variation. The template of the current control chart has an average of 26 minutes. Quality management methods, particularly staff involvement in problem analysis and intervention design, and the use of control charts were useful to understand, solve, and continuously monitor an important clinical problem whose existence was evident only after it was measured.

  17. Medium-dependent zone size discrepancies associated with susceptibility testing of group D streptococci against various cephalosporins.

    OpenAIRE

    Sahm, D F; Baker, C N; Jones, R N; Thornsberry, C

    1983-01-01

    Mueller-Hinton (MH) agar media from various commercial sources, either supplemented or not supplemented with 5% sheep blood, were studied to determine their effect on disk diffusion susceptibility testing results obtained with 90 strains of group D streptococci and four cephalosporins. The cephalosporins investigated included cephalothin, cefamandole, moxalactam, and cefotaxime. Results showed that a number of Streptococcus faecalis and Streptococcus faecium strains were susceptible to cephal...

  18. Micrometer- and nanometer-sized platinum group nuggets in micrometeorites from deep-sea sediments of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; Parashar, K.; ShyamPrasad, M.

    released in the troposphere could contain fractionated PGNs in large numbers. Keywords: cosmic spherules, platinum group element, nuggets, parent body, chondrites, impact craters 2    INTRODUCTION Micrometeorite flux on the Earth is estimated... of the parent body, angle of entry, entry velocity, and the physical properties of the incoming particle (Brownlee 1985). Three broad micrometeorite types have been recognized: S-type, I-type and the G-type. All the three could have the same parent body - a...

  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. Measurement of blood pressure for the diagnosis and management of hypertension in different ethnic groups: one size fits all.

    Science.gov (United States)

    Gill, Paramjit; Haque, M Sayeed; Martin, Una; Mant, Jonathan; Mohammed, Mohammed A; Heer, Gurdip; Johal, Amanpreet; Kaur, Ramandeep; Schwartz, Claire; Wood, Sally; Greenfield, Sheila M; McManus, Richard J

    2017-02-08

    Hypertension is a major risk factor for cardiovascular disease and prevalence varies by ethnic group. The diagnosis and management of blood pressure are informed by guidelines largely based on data from white populations. This study addressed whether accuracy of blood pressure measurement in terms of diagnosis of hypertension varies by ethnicity by comparing two measurement modalities (clinic blood pressure and home monitoring) with a reference standard of ambulatory BP monitoring in three ethnic groups. Cross-sectional population study (June 2010 - December 2012) with patients (40-75 years) of white British, South Asian and African Caribbean background with and without a previous diagnosis of hypertension recruited from 28 primary care practices. The study compared the test performance of clinic BP (using various protocols) and home-monitoring (1 week) with a reference standard of mean daytime ambulatory measurements using a threshold of 140/90 mmHg for clinic and 135/85 mmHg for out of office measurement. A total of 551 participants had complete data of whom 246 were white British, 147 South Asian and 158 African Caribbean. No consistent difference in accuracy of methods of blood pressure measurement was observed between ethnic groups with or without a prior diagnosis of hypertension: for people without hypertension, clinic measurement using three different methodologies had high specificity (75-97%) but variable sensitivity (33-65%) whereas home monitoring had sensitivity of 68-88% and specificity of 64-80%. For people with hypertension, detection of a raised blood pressure using clinic measurements had sensitivities of 34-69% with specificity of 73-92% and home monitoring had sensitivity (81-88%) and specificity (55-65%). For people without hypertension, ABPM remains the choice for diagnosing hypertension compared to the other modes of BP measurement regardless of ethnicity. Differences in accuracy of home monitoring and clinic monitoring (higher sensitivity

  1. 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

  2. Medium-sized Universities Connect to Their Libraries: Links on University Home Pages and User Group Pages

    Directory of Open Access Journals (Sweden)

    Pamela Harpel-Burk

    2006-03-01

    Full Text Available From major tasks—such as recruitment of new students and staff—to the more mundane but equally important tasks—such as providing directions to campus—college and university Web sites perform a wide range of tasks for a varied assortment of users. Overlapping functions and user needs meld to create the need for a Web site with three major functions: promotion and marketing, access to online services, and providing a means of communication between individuals and groups. In turn, college and university Web sites that provide links to their library home page can be valuable assets for recruitment, public relations, and for helping users locate online services.

  3. Effect of shape and size of amidoxime-group-containing adsorbent on the recovery of uranium from sea water

    International Nuclear Information System (INIS)

    Omichi, H.; Kataki, A.; Sugo, T.; Okamoto, J.; Katoh, S.; Sakane, K.; Sugasaka, K.; Itagaki, T.

    1987-01-01

    An amidoxime-group-containing adsorbent for the recovery of uranium from sea water was synthesized by radiation-induced graft polymerization of acrylonitrile onto polypropylene fiber of round and cross-shaped sections. The tensile strength and elongation of the synthesized adsorbent, both of which were one-half those of the raw material, were not affected by the shape of the fiber. The deterioration of the adsorption ability induced by immersing the adsorbent in HCl was negligible because of the short immersion time required for the desorption with HCl. The concentration factors for uranium and transition metals in 28 days were in the order of 10 5 , while those for alkali metals and alkaline earth metals were in the order 10 -1 -10 1 . The recovery of uranium with the cross-shaped adsorbent was superior to that of the round-shaped one. XMA line profiles show that the distribution of uranium is much restricted to the surface layer when compared with that of alkaline earth metals. Diminishing the diameter or increasing the surface area was effective for increasing the adsorption of uranium

  4. Delay discounting of different commodities.

    Science.gov (United States)

    Weatherly, Jeffrey N; Terrell, Heather K; Derenne, Adam

    2010-01-01

    When outcomes are delayed, their value is decreased. Delay discounting is a much-studied topic because it is correlated with certain disorders (e.g., pathological gambling). The present study attempts to determine how people would delay discount a number of different commodities, ranging from money to dating partners to federal education legislation. Participants completed delay discounting tasks pertaining to 5 different commodities, with a different set of 5 commodities for 2 groups. Results showed that different commodities were often discounted differently. Both data sets were also subjected to factor analysis. A 2-factor solution was found for both, suggesting that there are multiple "domains" of commodities. This finding is of interest because it suggests that measuring delay discounting for one commodity within a particular domain of commodities will be predictive of how people discount other commodities within that domain but will not be predictive of how they discount commodities within another domain.

  5. Prediction of the mesiodistal size of unerupted canines and premolars for a group of Romanian children: a comparative study

    Directory of Open Access Journals (Sweden)

    Cornel Gheorghe BOITOR

    2013-06-01

    Full Text Available Objectives The aim of the present study was to develop an optimization method of multiple linear regression equation (MLRE, using a genetic algorithm to determine a set of coefficients that minimize the prediction error for the sum of permanent premolars and canine dimensions in a group of young people from a central area of Romania represented by a city called Sibiu. Material and Methods To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers, to which we adjusted regression coefficients using the Breeder genetic algorithm. A total of 92 children were selected with complete permanent teeth with no clinically visible dental caries, proximal restorations or orthodontic treatment. A hard dental stone was made for each of these models, which was then measured with a digital calliper. The Dahlberg analyses of variance had been performed to determine the error of method, then the Correlation t Test was applied, and finally the MLRE equations were obtained using the version 16 for Windows of the SPSS program. Results The correlation coefficient of MLRE was between 51-67% and the significance level was set at α=0.05. Comparing predictions provided by the new and respectively old method, we can conclude that the Breeder genetic algorithm is capable of providing the best values for parameters of multiple linear regression equations, and thus our equations are optimized for the best performance. Conclusion The prediction error rates of the optimized equations using the Breeder genetic algorithm are smaller than those provided by the multiple linear regression equations proposed in the recent study.

  6. Position, swimming direction and group size of fin whales (Balaenoptera physalus in the presence of a fast-ferry in the Bay of Biscay

    Directory of Open Access Journals (Sweden)

    Ana S. Aniceto

    2016-07-01

    Full Text Available We analyze group size, swimming direction and the orientation of fin whales relative to a fast ferry in the Bay of Biscay. Fin whale groups (≥3 individuals were on average closer to the vessel than single individuals and pairs (F1,114 = 4.94, p = 0.028 and were more often observed within a high-risk angle ahead of the ferry (binomial probability: p = 7.60 × 10−11. Also, small groups tend to swim in the opposite direction (heading of 180° of the ferry at the starboard side (binomial test: p = 6.86 × 10−5 and at the portside (binomial test: p = 0.0156. These findings provide valuable information to improve shipping management procedures in areas at high risk for collisions.

  7. Delayed fatherhood.

    Science.gov (United States)

    Lawson, Gerald; Fletcher, Richard

    2014-10-01

    Birth data from developed countries indicates that the average paternal age is increasing. As the trend to older fatherhood has become established, concerns have been raised that this may be linked to adverse outcomes, such as pregnancy complications, congenital anomalies, and long-term health implications for the child. Since the sperm of older fathers may be impaired due to the general effects of ageing, their offspring may be at risk due to defects in sperm quality at conception. A literature search was performed to identify pregnancy complications, fetal anomalies and health issues for the child when the father is in an older age bracket. Evidence for impairment in the sperm and genetic material of older fathers was reviewed. With an older father, there is evidence of an increase in stillbirths and a slightly increased risk of autism, bipolar disorder and schizophrenia in the offspring later in life. The increased risk of achondroplasia has long been recognised. For the mother, there is an increased rate of Caesarean section. Investigations of other possible adverse outcomes have produced mixed findings. Further robust and longitudinal studies are needed to clarify these issues. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Rapid changes in the size of different functional organ and muscle groups during refueling in a long-distance migrating shorebird.

    Science.gov (United States)

    Piersma, T; Gudmundsson, G A; Lilliendahl, K

    1999-01-01

    The adaptive value of size changes in different organ and muscle groups was studied in red knots (Calidris canutus islandica) in relation to their migration. Birds were sampled on five occasions: at arrival in Iceland in May 1994, two times during subsequent refueling, at departure toward, and on return from, the high arctic breeding grounds. During their 24-d stopover in May, body mass increased from 144.3 to 214.5 g. Mass gains were lowest over the first week (0.85 g/d, only fat-free tissue deposited). Over the subsequent 10 d, average mass increased by 5.0 g/d (fat contributing 78%), and over the last week before takeoff, it increased by 2.0 g/d (fat contributing over 100% because of loss of lean components). There were no sex differences in body and fat mass gains. Over the first interval, lean masses of heart, stomach, and liver increased. During the middle 10 d, sizes of leg muscle, intestine, liver, and kidneys increased. Stomach mass decreased over the same interval. In the last interval before takeoff, the stomach atrophied further and the intestine, leg muscles, and liver became smaller too, but pectoral muscles and heart increased in size. Sizes of "exercise organs" such as pectoral muscle and heart were best correlated with body mass, whereas sizes of organs used during foraging (leg muscles) and nutrient extraction (intestine, liver) were best correlated with rate of mass gain. Kidneys changed little before takeoff, which suggests that they are needed as much during flight as during refueling.

  9. On routing algorithms with end-to-end delay guarantees

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.S.V.; Batsell, S.G.

    1998-11-01

    The authors consider the transmission of a message of size r from a source to a destination with guarantees on the end-to-end delay over a computer network with n nodes and m links. There are three sources of delays: (a) propagation delays along the links, (b) delays due to bandwidth availability on the links, and (c) queuing delays at the intermediate nodes. First, the authors consider that delays on various links and nodes are given as functions of the message size. If the delay in (b) is a non-increasing function of the bandwidth, they propose O(m{sup 2} + mn log n) time algorithm to compute a path with the minimum end-to-end delay for any given message size r. They then consider that the queuing delay in (c) is a random variable correlated with the message size according to an unknown distribution. At each node, the measurements of queuing delays and message sizes are available. They propose two algorithms to compute paths whose delays are close to optimal delays with a high probability, irrespective of the distribution of the delays, and based entirely on the measurements of sufficient size.

  10. Ricinus communis agglutinin-mediated agglutination and fusion of glycolipid-containing phospholipid vesicles: effect of carbohydrate head group size, calcium ions, and spermine.

    Science.gov (United States)

    Hoekstra, D; Düzgüneş, N

    1986-03-25

    The glycolipids galactosylcerebroside (GalCer), lactosylceramide (LacCer), and trihexosylceramide (Gb3) were inserted into phospholipid vesicles, consisting of phosphatidylethanolamine and phosphatidic acid. The extent to which their carbohydrate head groups protruded beyond the vesicle surface and their interference with membrane approach were examined by determining vesicle susceptibility toward type I Ricinus communis agglutinin (RCA1) induced agglutination and Ca2+- and spermine-induced aggregation and fusion either in the presence or in the absence of the lectin. The initial agglutination rates increased in the order GalCer much less than LacCer less than Gb3, while a reversed order was obtained for Ca2+- and spermine-induced aggregation and fusion, indicating an enhanced steric interference on close approach of bilayers with increasing head group size. The lectin-mediated agglutination rates for LacCer- and Gb3-containing vesicles increased by an order of magnitude when Ca2+ was also included in the medium, at a concentration that did not induce aggregation per se. Charge neutralization could not account for this observation as the polyvalent cation spermine did not display this synergistic effect with RCA1. Addition of Ca2+ to preagglutinated vesicles substantially reduced the threshold cation concentration for fusion (micromolar vs. millimolar). Quantitatively, this concentration decreased with decreasing carbohydrate head group size, indicating that the head group protrusion determined the interbilayer distance within the vesicle aggregate. The distinct behavior of Ca2+ vs. spermine on RCA1-induced agglutination on the one hand and fusion on the other indicated that Ca2+ regulates the steric orientation of the carbohydrate head group, which appears to be related to its ability to dehydrate the bilayer. As a result, lectin agglutinability becomes enhanced while fusion will be interrupted as the interbilayer distance increases, the threshold head group size

  11. Reduction of mercury(II) by tropical river humic substances (Rio Negro)-Part II. Influence of structural features (molecular size, aromaticity, phenolic groups, organically bound sulfur).

    Science.gov (United States)

    Rocha, Julio Cesar; Sargentini, Ezio; Zara, Luiz Fabricio; Rosa, André Henrique; Dos Santos, Ademir; Burba, Peter

    2003-12-04

    The influence of structural features of tropical river humic substances (HS) on their capability to reduce mercury(II) in aqueous solutions was studied. The HS investigated were conventionally isolated from Rio Negro water-Amazonas State/Brazil by means of the collector XAD 8. In addition, the isolated HS were on-line fractionated by tangential-flow multistage ultrafiltration (nominal molecular-weight cut-offs: 100, 50, 30, 10, 5 kDa) and characterized by potentiometry and UV/VIS spectroscopy. The reduction of Hg(II) ions to elemental Hg by size-fractions of Rio Negro HS was assessed by cold-vapor AAS (CVAAS). UV/VIS spectrometry revealed that the fractions of high molecular-size (F(1)>100 kDa and F(2): 50-100 kDa) have a higher aromaticity compared to the fractions of small molecular-size (F(5): 5-10 kDa, F(6): F(2)>F(1)>F(3)>F(4)>F(6)). Accordingly, Hg(II) ions were preferably reduced by HS molecules having a relatively high ratio of phenolic/carboxylic groups and a small concentration of sulfur. From these results a complex 'competition' between reduction and complexation of mercury(II) by aquatic HS occurring in tropical rivers such as the Rio Negro can be suggested.

  12. Use of care management practices in small- and medium-sized physician groups: do public reporting of physician quality and financial incentives matter?

    Science.gov (United States)

    Alexander, Jeffrey A; Maeng, Daniel; Casalino, Lawrence P; Rittenhouse, Diane

    2013-04-01

    To examine the effect of public reporting (PR) and financial incentives tied to quality performance on the use of care management practices (CMPs) among small- and medium-sized physician groups. Survey data from The National Study of Small and Medium-sized Physician Practices were used. Primary data collection was also conducted to assess community-level PR activities. The final sample included 643 practices engaged in quality reporting; about half of these practices were subject to PR. We used a treatment effects model. The instrumental variables were the community-level variables that capture the level of PR activity in each community in which the practices operate. (1) PR is associated with increased use of CMPs, but the estimate is not statistically significant; (2) financial incentives are associated with greater use of CMPs; (3) practices' awareness/sensitivity to quality reports is positively related to their use of CMPs; and (4) combined PR and financial incentives jointly affect CMP use to a greater degree than either of these factors alone. Small- to medium-sized practices appear to respond to PR and financial incentives by greater use of CMPs. Future research needs to investigate the appropriate mix and type of incentive arrangements and quality reporting. © Health Research and Educational Trust.

  13. Sample size and classification error for Bayesian change-point models with unlabelled sub-groups and incomplete follow-up.

    Science.gov (United States)

    White, Simon R; Muniz-Terrera, Graciela; Matthews, Fiona E

    2018-05-01

    Many medical (and ecological) processes involve the change of shape, whereby one trajectory changes into another trajectory at a specific time point. There has been little investigation into the study design needed to investigate these models. We consider the class of fixed effect change-point models with an underlying shape comprised two joined linear segments, also known as broken-stick models. We extend this model to include two sub-groups with different trajectories at the change-point, a change and no change class, and also include a missingness model to account for individuals with incomplete follow-up. Through a simulation study, we consider the relationship of sample size to the estimates of the underlying shape, the existence of a change-point, and the classification-error of sub-group labels. We use a Bayesian framework to account for the missing labels, and the analysis of each simulation is performed using standard Markov chain Monte Carlo techniques. Our simulation study is inspired by cognitive decline as measured by the Mini-Mental State Examination, where our extended model is appropriate due to the commonly observed mixture of individuals within studies who do or do not exhibit accelerated decline. We find that even for studies of modest size ( n = 500, with 50 individuals observed past the change-point) in the fixed effect setting, a change-point can be detected and reliably estimated across a range of observation-errors.

  14. Influence of control group on effect size in trials of acupuncture for chronic pain: a secondary analysis of an individual patient data meta-analysis.

    Directory of Open Access Journals (Sweden)

    Hugh MacPherson

    Full Text Available In a recent individual patient data meta-analysis, acupuncture was found to be superior to both sham and non-sham controls in patients with chronic pain. In this paper we identify variations in types of sham and non-sham controls used and analyze their impact on the effect size of acupuncture.Based on literature searches of acupuncture trials involving patients with headache and migraine, osteoarthritis, and back, neck and shoulder pain, 29 trials met inclusion criteria, 20 involving sham controls (n = 5,230 and 18 non-sham controls (n = 14,597. For sham controls, we analysed non-needle sham, penetrating sham needles and non-penetrating sham needles. For non-sham controls, we analysed non-specified routine care and protocol-guided care. Using meta-regression we explored impact of choice of control on effect of acupuncture.Acupuncture was significantly superior to all categories of control group. For trials that used penetrating needles for sham control, acupuncture had smaller effect sizes than for trials with non-penetrating sham or sham control without needles. The difference in effect size was -0.45 (95% C.I. -0.78, -0.12; p = 0.007, or -0.19 (95% C.I. -0.39, 0.01; p = 0.058 after exclusion of outlying studies showing very large effects of acupuncture. In trials with non-sham controls, larger effect sizes associated with acupuncture vs. non-specified routine care than vs. protocol-guided care. Although the difference in effect size was large (0.26, it was not significant with a wide confidence interval (95% C.I. -0.05, 0.57, p = 0.1.Acupuncture is significantly superior to control irrespective of the subtype of control. While the choice of control should be driven by the study question, our findings can help inform study design in acupuncture, particularly with respect to sample size. Penetrating needles appear to have important physiologic activity. We recommend that this type of sham be avoided.

  15. Natural endocrine profiles of the group-living skunk anemonefish Amphiprion akallopisos in relation to their size-based dominance hierarchy.

    Science.gov (United States)

    Mills, S C; O'Donnell, J L; Bernardi, G; Beldade, R

    2018-03-01

    Group-living animals commonly display differences in behaviour, physiology and endocrine profiles between conspecifics within the group, which are tightly linked to reproduction. Teleosts exhibit a variety of social systems, where social status, as well as sex, has been linked to different androgen and oestrogen profiles. Levels of gonadal androgen and oestrogen were investigated as a function of sex and position in a social hierarchy in free-living individuals of the skunk anemonefish Amphiprion akallopisos, a protandrous pomacentrid fish with a size-based dominance hierarchical social system. Plasma levels of 11-ketotestosterone (11-KT), testosterone (T) and 17β-oestradiol (E 2 ), as well as conversion ratios from T, were measured by ELISA from 111 individuals along a linear hierarchy from 38 social groups in the wild. Blood plasma levels of 11-KT and E 2 showed sex differences, being higher in males and females respectively as expected based on their role as the major androgen and oestrogen in fish reproduction. However, no sex differences were found for T, which may represent its role in territorial defence or simply as a precursor for the synthesis of 11-KT and E 2 . In terms of the hierarchical social system within males, 11-KT levels decline as the hierarchy is descended, which may represent their decreasing reproductive opportunity, as well as the decreasing levels of aggression towards males lower in the hierarchy. In summary, the size-based dominance hierarchy is associated with distinct steroid levels of 11-KT and E 2 between individual free-living A. akallopisos that closely resemble those of species in which breeding individuals suppress reproduction of conspecifics lower in the hierarchy. © 2018 The Fisheries Society of the British Isles.

  16. Local density and group size interacts with age and sex to determine direction and rate of social dispersal in a polygynous mammal.

    Science.gov (United States)

    Marjamäki, Paula H; Contasti, Adrienne L; Coulson, Tim N; McLoughlin, Philip D

    2013-09-01

    Movement away from an area or social group in response to increasing density (density-dependent dispersal) is known for most species; why it evolves is fundamental to our understanding of ecology and evolution. However, we have yet to fully appreciate how individuals of varying conditions (e.g., age and sex) might differently consider effects of density (quorum) when deciding to disperse or not, and scale dependence in their sense of quorum. We tracked movements of all individuals of a naturalized population of feral horses (Equus ferus caballus; Sable Island National Park Reserve, Nova Scotia, Canada) during a period of rapid population growth (N increased from 375 to 484 horses from 2008 to 2010). Permanent dispersal from breeding groups (bands) was positively density dependent for all age and sex categories with respect to local density (horses/km(2), bounded by the 99th percentile of individual movements [8000 m]), but was negatively and positively density dependent for males and females, respectively, in relation to group (band) size. Dispersal was generally female biased, with the exception of foals which moved with their mothers (no sex effect), and for yearlings and subadults when band sizes were smaller than average, in which case males dispersed at higher rates than females. Dispersal distance was positively related to local density. We conclude that dispersal rate can be both positively and negatively density dependent for feral horses, contingent on the state of individuals and the scale at which quorum with respect to choosing to disperse or not is assessed. Scale effects and interactions of density-dependent and sex- and age-biased dispersal may have both ecological and evolutionary consequences through effects on resource and mate competition.

  17. Agrupamento de colheitas de tomate e estimativas do tamanho de parcela em cultivo protegido Grouping in tomato harvests and estimates of the plot size in protected environment

    Directory of Open Access Journals (Sweden)

    Alessandro Dal'Col Lúcio

    2010-06-01

    Full Text Available Para verificar qual a interferência da variabilidade das estimativas dos valores usados para determinação do tamanho de parcela com simulações de diferentes números de plantas por parcela e agrupamentos de colheitas, realizou-se um trabalho com três experimentos de tomate no Departamento de Fitotecnia da UFSM. Em dois experimentos foram utilizados túneis plásticos, com irrigação por gotejamento, camalhões com mulching preto de PEDB, três linhas de cultivo, 24 plantas por linha, espaçamento entre plantas 0,8 m e entre filas 1,2 m e uma estufa plástica no terceiro, essa com dimensões de 24 m de comprimento por 10 m de largura em oito linhas de cultivo. Todos os tratos culturais foram realizados com base na recomendação para a cultura (Filgueira, 2000, sendo aplicados concomitantemente nos três experimentos. A seqüência de duas, três e quatro plantas na linha de cultivo formou as parcelas de duas, três e quatro unidades básicas de tamanho. Foram realizadas análises considerando-se apenas colheitas individuais e colheitas agrupadas. Foram estimados a variância, o coeficiente de variação e o índice de informação relativa. Aplicou-se o teste de Bartlett entre as variâncias das colheitas individuais e agrupadas em cada tamanho de parcela simulado para verificar sua homogeneidade. As variâncias, entre as colheitas agrupadas, são homogêneas a partir do agrupamento de seis colheitas. Há acréscimos nas estimativas da variância da fitomassa de frutos com o aumento do tamanho da parcela e/ou o número de colheitas agrupadas. Parcelas de quatro plantas na linha de cultivo, combinados com agrupamento de seis em seis colheitas reduzem a variabilidade.The variability interference was verified on the estimates of the values used to determine the plot size with simulations of different numbers of plants per plot and groupings of harvests. Three experiments were performed with the tomato crop in the winter/spring of 2007

  18. Context matters: volunteer bias, small sample size, and the value of comparison groups in the assessment of research-based undergraduate introductory biology lab courses.

    Science.gov (United States)

    Brownell, Sara E; Kloser, Matthew J; Fukami, Tadashi; Shavelson, Richard J

    2013-01-01

    The shift from cookbook to authentic research-based lab courses in undergraduate biology necessitates the need for evaluation and assessment of these novel courses. Although the biology education community has made progress in this area, it is important that we interpret the effectiveness of these courses with caution and remain mindful of inherent limitations to our study designs that may impact internal and external validity. The specific context of a research study can have a dramatic impact on the conclusions. We present a case study of our own three-year investigation of the impact of a research-based introductory lab course, highlighting how volunteer students, a lack of a comparison group, and small sample sizes can be limitations of a study design that can affect the interpretation of the effectiveness of a course.

  19. Delayed cure bismaleimide resins

    Science.gov (United States)

    Adams, Johnnie E.; Jamieson, Donald R.

    1984-08-07

    Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, Cl or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH.sub.2).sub.n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.

  20. Dive Distribution and Group Size Parameters for Marine Species Occurring in the U.S. Navy’s Atlantic and Hawaii-Southern California Training and Testing Study Areas

    Science.gov (United States)

    2017-06-09

    Blue whales track the diel vertical migration of their prey and feed almost exclusively on euphausiids, Marine Species Dive Distribution and Group ...Size Information 3.1 Introduction Many marine mammals are known to travel and feed in groups . The NAEMO accounts for this behavior by...Marine Species Dive Distribution and Group Size Parameters Technical Report 9 June 2017 NUWC-NPT Technical Report 12,243 9 June 2017 Dive

  1. Pretreatment with Pancaspase Inhibitor (Z-VAD-FMK Delays but Does Not Prevent Intraperitoneal Heat-Killed Group B Streptococcus-Induced Preterm Delivery in a Pregnant Mouse Model

    Directory of Open Access Journals (Sweden)

    Ozlem Equils

    2009-01-01

    Full Text Available Caspases and apoptosis are thought to play a role in infection-associated preterm-delivery. We have shown that in vitro treatment with pancaspase inhibitor Z-VAD-FMK protects trophoblasts from microbial antigen-induced apoptosis. Objective. To examine whether in vivo administration of Z-VAD-FMK would prevent infection-induced preterm-delivery. Methods. We injected 14.5 day-pregnant-mice with heat-killed group B streptococcus (HK-GBS. Apoptosis within placentas and membranes was assessed by TUNEL staining. Calpain expression and caspase-3 activation were assessed by immunohistochemistry. Preterm-delivery was defined as expulsion of a fetus within 48 hours after injection. Results. Intrauterine (i.u. or intraperitoneal (i.p. HK-GBS injection led to preterm-delivery and induced apoptosis in placentas and membranes at 14 hours. The expression of calpain, a caspase-independent inducer of apoptosis, was increased in placenta. Treatment with the specific caspase inhibitor Z-VAD-FMK (i.p. prior to HK-GBS (i.p. delayed but did not prevent preterm-delivery. Conclusion. Caspase-dependent apoptosis appears to play a role in the timing but not the occurrence of GBS-induced preterm delivery in the mouse.

  2. The effect of social group size on feather corticosterone in the co-operatively breeding Smooth-billed Ani (Crotophaga ani: An assay validation and analysis of extreme social living.

    Directory of Open Access Journals (Sweden)

    Joshua K Robertson

    Full Text Available Living closely with others can provide a myriad of fitness benefits, from shared territory defense to co-operative resource acquisition. Costs of social aggregation are not absent, however, and likely influence optimal and observed groups' sizes in a social species. Here, we explored optimal group size in a joint-nesting cuckoo species (the Smooth-billed Ani, Crotophaga ani using endocrine markers of stress physiology (corticosterone, or CORT. Smooth-billed Anis exhibit intense reproductive competition that is exacerbated in atypically large groups. We therefore hypothesized that intra-group competition (measured by social group size mediates the desirability and physiological cost of social group membership in this species. To test this hypothesis, we captured 47 adult Smooth-billed Anis (31 males, 16 females during the breeding seasons of 2012-2014 in south-western Puerto Rico, and documented social group sizes. Tail feathers were sampled and used to quantify CORT (pg/mg in enzyme-linked immunosorbent assays (ELISAs (n = 50. Our analyses show significant differences in feather-CORT of adults between categorical group sizes, with individuals from atypically large social groups (≥ x + 1SD having highest mean concentrations (33.319 pg/mg, and individuals from atypically small social groups (≤ x - 1SD having lowest mean concentrations (8.969 pg/mg. Whether reproductive competition or effort is responsible for elevated CORT in atypically large social groups, however, remains unclear. Our results suggest that living in atypically large groups is physiologically expensive and may represent an evolutionarily unstable strategy. To our knowledge, this is the first study to explore a correlation between stress physiology and group size in a joint-nesting species.

  3. CAREGIVER-CHILD INTERACTION, CAREGIVER TRANSITIONS, AND GROUP SIZE AS MEDIATORS BETWEEN INTERVENTION CONDITION AND ATTACHMENT AND PHYSICAL GROWTH OUTCOMES IN INSTITUTIONALIZED CHILDREN.

    Science.gov (United States)

    Warner, Hilary A; McCall, Robert B; Groark, Christina J; Kim, Kevin H; Muhamedrahimov, Rifkat J; Palmov, Oleg I; Nikiforova, Natalia V

    2017-09-01

    This report describes a secondary analysis of data from a comprehensive intervention project which included training and structural changes in three Baby Homes in St. Petersburg, Russian Federation. Multiple mediator models were tested according to the R.M. Baron and D.A. Kenny () causal-steps approach to examine whether caregiver-child interaction quality, number of caregiver transitions, and group size mediated the effects of the intervention on children's attachment behaviors and physical growth. The study utilized a subsample of 163 children from the original Russian Baby Home project, who were between 11 and 19 months at the time of assessment. Results from comparisons of the training and structural changes versus no intervention conditions are presented. Caregiver-child interaction quality and number of caregiver transitions fully mediated the association between intervention condition and attachment behavior. No other mediation was found. Results suggest that the quality of interaction between caregivers and children in institutional care is of primary importance to children's development, but relationship context may play a less direct mediational role, supporting caregiver-child interactions. © 2017 Michigan Association for Infant Mental Health.

  4. Calculating and reporting effect sizes on scientific papers (1: p < 0.05 limitations in the analysis of mean differences of two groups

    Directory of Open Access Journals (Sweden)

    Helena Espirito Santo

    2015-02-01

    Since p-values from the results of the statistical tests do not indicate the magnitude or importance of a difference, then effect sizes (ES should reported. In fact, ES give meaning to statistical tests; emphasize the power of statistical tests; reduce the risk of interpret mere sampling variation as real relationship; can increase the reporting of “non-significant"results, and allow the accumulation of knowledge from several studies using meta-analysis. Thus, the objectives of this paper are to present the limits of the significance level; describe the foundations of presentation of ES of statistical tests to analyze differences between two groups; present the formulas to calculate directly ES, providing examples of our own previous studies; show how to calculate confidence intervals; provide the conversion formulas for the review of the literature; indicate how to interpret the ES; and show that, although interpretable, the meaning (small, medium or large effect for an arbitrary metric could be inaccurate, requiring that interpretation should be made in the context of the research area and in the context of real world variables.

  5. Delay correlation analysis and representation for vital complaint VHDL models

    Science.gov (United States)

    Rich, Marvin J.; Misra, Ashutosh

    2004-11-09

    A method and system unbind a rise/fall tuple of a VHDL generic variable and create rise time and fall time generics of each generic variable that are independent of each other. Then, according to a predetermined correlation policy, the method and system collect delay values in a VHDL standard delay file, sort the delay values, remove duplicate delay values, group the delay values into correlation sets, and output an analysis file. The correlation policy may include collecting all generic variables in a VHDL standard delay file, selecting each generic variable, and performing reductions on the set of delay values associated with each selected generic variable.

  6. Delays in Building Construction Projects in Ghana

    Directory of Open Access Journals (Sweden)

    Frank DK Fugar

    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.

  7. On the Impact of Sample Size on LC50Estimation in Acute Fish Toxicity Testing: Is N = 7/Group Enough?

    Science.gov (United States)

    Carr, Greg J; Bailer, A John; Rawlings, Jane M; Belanger, Scott E

    2018-01-19

    The fish acute toxicity test method is foundational to aquatic toxicity testing strategies, yet the literature lacks a concise sample size assessment. While various sources address sample size, historical precedent seems to play a larger role than objective measures. Here, a novel and comprehensive quantification of the effect of sample size on estimation of the LC 50 is presented, covering a wide range of scenarios. The results put into perspective the practical differences across a range of sample sizes, from N = 5/concentration up to N = 23/concentration. This work provides a framework for setting sample size guidance. It illustrates ways to quantify the performance of LC 50 estimation, which can be used to set sample size guidance given reasonably difficult, or worst-case scenarios. There is a clear benefit to larger sample size studies: they reduce error in the determination of LC 50 s, and lead to more robust safe environmental concentration determinations, particularly in cases likely to be called worst-case (shallow slope and true LC 50 near the edges of the concentration range). Given that the use of well-justified sample sizes is crucial to reducing uncertainty in toxicity estimates, these results lead us to recommend a reconsideration of the current de minimis 7/concentration sample size for critical studies (e.g., studies needed for a chemical registration, which are being tested for the first time, or involving difficult test substances). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Effect of preharvest understory treatment and group opening size on four-year survival of advance reproduction in the Boston Mountains of Arkansas

    Science.gov (United States)

    Martin A. Spetich; David L. Graney

    2003-01-01

    The purpose of this study was to examine survival of regeneration in small openings. Six forest stands were located in 1990 and three understory treatments were applied to each in early 1991. In each stand, six sizes of openings were created in 1992 ranging in size from 0.025 ac to 0.50 ac. Understory treatments consisted of: 1) no control of competing regeneration, 2...

  9. Analyzing delay causes in Egyptian construction projects.

    Science.gov (United States)

    Marzouk, Mohamed M; El-Rasas, Tarek I

    2014-01-01

    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.

  10. Digital time delay

    Science.gov (United States)

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  11. Delayed Sequence Intubation

    DEFF Research Database (Denmark)

    Weingart, Scott D; Trueger, N Seth; Wong, Nelson

    2015-01-01

    assessed. RESULTS: A total of 62 patients were enrolled: 19 patients required delayed sequence intubation to allow nonrebreather mask, 39 patients required it to allow NIPPV, and 4 patients required it for nasogastric tube placement. Saturations increased from a mean of 89.9% before delayed sequence...

  12. A general relation for group delay and the relevance of group delay for refractometric sensing

    NARCIS (Netherlands)

    Hoekstra, Hugo; Hammer, Manfred

    2014-01-01

    The relevance of our definition for sensitivity in refractometric sensing, being the relative change in the transmittance of a certain output channel of an optical device over the change in the refractive index of the probed material, is discussed. It is compared to one based on spectral shift per

  13. 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......, fertility decisions and labor supply alternatives faced by the individuals over different stages of the life cycle. The delays in giving birth and buying first home arise endogenously.......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...

  14. IMPACT OF THE IMPLEMENTATION OF QUALITY MANAGEMENT SYSTEM ON OPERATING COST FOR SMALL AND MEDIUM - SIZED BUSINESS ORGANIZATIONS AFFILIATED TO A PURCHASING GROUP

    Directory of Open Access Journals (Sweden)

    Dominik Zimon

    2015-12-01

    Full Text Available Purpose - The purpose of this paper is to ask one question. How the implementation of the requirements of ISO 9001 system affects the costs of running the business? Design/methodology/approach - The research covered time from 2006 to 2011 and was an attempt to assess the impact of the maintenance of the ISO 9001 Quality Management System on the costs of small and medium sized business organizations. The main objective was the selection of right research subjects that would allow the formulation of the most reliable and statistically valid conclusions. For this purpose we obtained permissions to conduct research in organizations characterized by comparable futures such as size, industry, type of business and strategy. Findings - The study shows that the costs associated with the implementation and maintenance of the Quality Management System standard is still too high, and effectively discourages representatives of small and medium-sized commercial organizations from implementing ISO 9001 system.

  15. Pengaruh Faktor Internal dan Eksternal pada Audit Delay

    OpenAIRE

    Ramantha, I Wayan; Yadnyana, I Ketut; Karang, Ni Made Dwi Umidyathi

    2015-01-01

    This research aims to reveal (1) the effect of company size on audit delay, (2) the effect of company€™s profitability on audit delay, (3) the effect of solvability on audit delay, (4) the effect of auditor quality on audit delay and (5) the effect of auditor opinion on audit delay of companies listed on Indonesian Stock Exchange. The data population used in this research are all the companies that are listed in BEI. The sample were taken randomly using Slovin equation, as a result, there wer...

  16. Challenges of flow-cytometric estimation of nuclear genome size in orchids, a plant group with both whole-genome and progressively partial endoreplication.

    Science.gov (United States)

    Trávníček, Pavel; Ponert, Jan; Urfus, Tomáš; Jersáková, Jana; Vrána, Jan; Hřibová, Eva; Doležel, Jaroslav; Suda, Jan

    2015-10-01

    Nuclear genome size is an inherited quantitative trait of eukaryotic organisms with both practical and biological consequences. A detailed analysis of major families is a promising approach to fully understand the biological meaning of the extensive variation in genome size in plants. Although Orchidaceae accounts for ∼10% of the angiosperm diversity, the knowledge of patterns and dynamics of their genome size is limited, in part due to difficulties in flow cytometric analyses. Cells in various somatic tissues of orchids undergo extensive endoreplication, either whole-genome or partial, and the G1-phase nuclei with 2C DNA amounts may be lacking, resulting in overestimated genome size values. Interpretation of DNA content histograms is particularly challenging in species with progressively partial endoreplication, in which the ratios between the positions of two neighboring DNA peaks are lower than two. In order to assess distributions of nuclear DNA amounts and identify tissue suitable for reliable estimation of nuclear DNA content, we analyzed six different tissue types in 48 orchid species belonging to all recognized subfamilies. Although traditionally used leaves may provide incorrect C-values, particularly in species with progressively partial endoreplication, young ovaries and pollinaria consistently yield 2C and 1C peaks of their G1-phase nuclei, respectively, and are, therefore, the most suitable parts for genome size studies in orchids. We also provide new DNA C-values for 22 orchid genera and 42 species. Adhering to the proposed methodology would allow for reliable genome size estimates in this largest plant family. Although our research was limited to orchids, the need to find a suitable tissue with dominant 2C peak of G1-phase nuclei applies to all endopolyploid species. © 2015 International Society for Advancement of Cytometry.

  17. Relation between early motor delay and later communication delay in infants at risk for autism.

    Science.gov (United States)

    Bhat, A N; Galloway, J C; Landa, R J

    2012-12-01

    Motor delays have been reported in retrospective studies of young infants who later develop Autism Spectrum Disorders (ASDs). In this study, we prospectively compared the gross motor development of a cohort at risk for ASDs; infant siblings of children with ASDs (AU sibs) to low risk typically developing (LR) infants. 24 AU sibs and 24 LR infants were observed at 3 and 6 months using a standardized motor measure, the Alberta Infant Motor Scale (AIMS). In addition, as part of a larger study, the AU sibs also received a follow-up assessment to determine motor and communication performance at 18 months using the Mullen Scales of Early Learning. Significantly more AU sibs showed motor delays at 3 and 6 months than LR infants. The majority of the AU sibs showed both early motor delays and later communication delays. Small sample size and limited follow-up. Early motor delays are more common in AU sibs than LR infants. Communication delays later emerged in 67-73% of the AU sibs who had presented with early motor delays. Overall, early motor delays may be predictive of future communication delays in children at risk for autism. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. 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)

  19. Challenges of flow-cytometric estimation of nuclear genome size in orchids, a plant group with both whole-genome and progressively partial endoreplication

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Pavel; Ponert, J.; Urfus, Tomáš; Jersáková, Jana; Vrána, Jan; Hřibová, Eva; Doležel, Jaroslav; Suda, Jan

    2015-01-01

    Roč. 87, č. 10 (2015), s. 958-966 ISSN 1552-4922 R&D Projects: GA ČR GAP506/12/1320 Institutional support: RVO:67985939 ; RVO:67179843 ; RVO:61389030 Keywords : flow cytometry * genome size * hyporeduplication Subject RIV: EF - Botanics; EF - Botanics (UEB-Q); EH - Ecology, Behaviour (UEK-B) Impact factor: 3.181, year: 2015

  20. 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...

  1. Modeling mechanisms of persisting and resolving delay in language development.

    Science.gov (United States)

    Thomas, Michael S C; Knowland, V C P

    2014-04-01

    PURPOSE In this study, the authors used neural network modeling to investigate the possible mechanistic basis of developmental language delay and to test the viability of the hypothesis that persisting delay and resolving delay lie on a mechanistic continuum with normal development. METHOD The authors used a population modeling approach to study individual rates of development in 1,000 simulated individuals acquiring a notional language domain (in this study, represented by English past tense). Variation was caused by differences in internal neurocomputational learning parameters as well as the richness of the language environment. An early language delay group was diagnosed, and individual trajectories were then traced. RESULTS Quantitative variations in learning mechanisms were sufficient to produce persisting delay and resolving delay subgroups in similar proportions to empirical observations. In the model, persisting language delay was caused by limitations in processing capacity, whereas resolving delay was caused by low plasticity. Richness of the language environment did not predict the emergence of persisting delay but did predict the final ability levels of individuals with resolving delay. CONCLUSION Mechanistically, it is viable that persisting delay and resolving delay are only quantitatively different. There may be an interaction between environmental factors and outcome groups, with individuals who have resolving delay being influenced more by the richness of the language environment.

  2. Delayed puberty in boys

    Science.gov (United States)

    ... In most cases, delayed puberty is simply a matter of growth changes beginning later than usual, sometimes ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  3. Delayed puberty in girls

    Science.gov (United States)

    ... with too little body fat, gaining a bit of weight may help trigger puberty. If delayed puberty is caused by a disease or an eating disorder, treating the cause may help puberty to develop normally. If puberty ...

  4. Vernier Delay Unit

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Choice and reinforcement delay

    OpenAIRE

    Gentry, G. David; Marr, M. Jackson

    1980-01-01

    Previous studies of choice between two delayed reinforcers have indicated that the relative immediacy of the reinforcer is a major determinant of the relative frequency of responding. Parallel studies of choice between two interresponse times have found exceptions to this generality. The present study looked at the choice by pigeons between two delays, one of which was always four times longer than the other, but whose absolute durations were varied across conditions. The results indicated th...

  6. 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

  7. Delayed sleep onset in depressed young people.

    Science.gov (United States)

    Glozier, Nicholas; O'Dea, Bridianne; McGorry, Patrick D; Pantelis, Christos; Amminger, Günter Paul; Hermens, Daniel F; Purcell, Rosemary; Scott, Elizabeth; Hickie, Ian B

    2014-02-08

    The circadian abnormality of delayed sleep phase has been suggested to characterise a subgroup of depressed young adults with different risk factors and course of illness. We aim to assess the prevalence and factors, particularly substance use, associated with such delay in a large help-seeking cohort of young people with mental health problems. From a consecutively recruited sample of 802 help-seeking young people, 305 (38%) had at least moderate depressive symptoms (QIDS-C16 >10), sleep data and did not have a chronic severe mental illness. Demographic and clinical characteristics were evaluated through self report and clinical interview. Delayed sleep phase was defined as a sleep onset between the hours of 02:00 a.m. - 06:00 a.m. and the characteristics of this group were compared to normal phase sleepers. Delayed sleep onset was reported amongst 18% (n = 56/305) of the depressed group compared to 11% of the non-depressed young people. Amongst the depressed group, delayed sleep onset was associated with tobacco, alcohol and cannabis misuse and short sleep duration (x̅: 5.8 hrs vs. x̅: 7.8 hrs). There were no differences in demographic factors, personality traits or symptoms. Tobacco smoking was very common: In logistic regression analyses only tobacco use (OR 2.28, 95% CI: 1.04 - 5.01) was associated with delayed sleep onset. There was no interaction with age. Delayed sleep onset was twice as common in depressed young people as the general population and young people with other mental health problems, and is a potential marker for a subgroup of mood disorders. Those with delayed sleep onset were not more severely depressed but had short sleep duration, a risk for chronic psychological ill health, and higher levels of tobacco use. Nicotine use was common in this group, has biological evidence as a sleep disrupter, and requires specifically addressing in this population.

  8. Effects of Suspended Moxibustion on Delayed Onset Muscle Soreness: A Randomized Controlled Double-Blind Pilot Study.

    Science.gov (United States)

    Meng, Ding; Xiaosheng, Dong; Xuhui, Wang; Xu, Wang; Xijin, Zhang

    2017-06-01

    The objective of this study was to investigate the effects of suspended moxibustion upon tender point on delayed onset muscle soreness. The study was a randomized double-blind controlled trial with 50 subjects in each group. Subjects in moxibustion group received suspended moxibustion upon tender point (by palpation) twice. The controls received no treatment. Each subject received treatments twice, 24 hr and 48 hr after the delayed onset muscle soreness induction. The measurements of Pain Visual Analog Scale, maximum isometric muscle strength and circumference were made immediately after delayed onset muscle soreness induction, before and after every treatment session and 72 hr after delayed onset muscle soreness induction. There were no significantly statistical differences between two groups at all measurement time points on maximum isometric muscle strength and circumference. However, the Pain Visual Analog Scale scores after first treatment session and 72 hr after delayed onset muscle soreness induction in moxibustion group was less than the control group, with significant difference (p soreness. However, results need to be cautiously interpreted because of the pilot character of this study. The suspended moxibustion has a potential effect of pain relief on DOMS from the analysis of the data of this study. A large sample size trial is needed to confirm the effect of the suspended moxibustion on DOMS in the future.

  9. Factors associated with delayed Antenatal Care attendance in Malawi

    African Journals Online (AJOL)

    SITWALA COMPUTERS

    15,16 school, and to be stigmatized. The stigma and shame of an unwanted pregnancy influenced delaying antenatal care. Despite the small sample size, our study reveals that unplanned or unwanted pregnancies were one of the factors associated with delayed ANC attendance. This was especially apparent if the woman ...

  10. Wideband RF beamforming: architectures, time-delays and cmos implementations

    NARCIS (Netherlands)

    Garakoui, S.K.

    2015-01-01

    A phased array antenna is a kind of antenna which is electronically reconfigurable to realize different antenna beam patterns. Delay blocks are an essential part of phased array antenna systems. Their delay-range, noise, nonlinearity, bandwidth, size, cost and power consumption have a dominant

  11. "I Would Rather Be Size 10 Than Have Straight A's": A Focus Study Group of Adolescent Girls' Wish To Be Thinner.

    Science.gov (United States)

    Tiggemann, Marika; Gardiner, Maria; Slater, Amy

    2000-01-01

    Investigates the body concerns of adolescent girls (N=67), together with the underlying motivations for wishes to be thinner. Results of focus group studies reveal that sociocultural influences exerted the strongest pressures to be thin. The girls displayed an unexpected sophistication in their conceptualization of the role of both media effects…

  12. Portion size

    Science.gov (United States)

    ... with hummus. To control your portion sizes when eating out, try these tips: Order the small size. Instead of a medium or large, ask for the smallest size. By eating a small hamburger instead of a large, you ...

  13. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2011-01-01

    Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two......-stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during...... of reoperation was significantly higher following the one-stage procedure. For both procedures, the majority of reoperations were due to asymmetry or displacement of the implant. In conclusion, non-radiated one- and two-stage delayed breast implant reconstructions are associated with substantial risks...

  14. Severe delayed skin reactions related to drugs in the paediatric age group: A review of the subject by way of three cases (Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS).

    Science.gov (United States)

    Belver, M T; Michavila, A; Bobolea, I; Feito, M; Bellón, T; Quirce, S

    2016-01-01

    Severe delayed drug-induced skin reactions in children are not common but potentially serious. This article describes aspects concerning the etiology, pathogenesis and clinical manifestations of these processes; it presents three paediatric cases, namely STS (Steven Johnson Syndrome), TEN (toxic epidermal necrolysis), probably related to amoxicillin/clavulanate and ibuprofen and DRESS (a drug reaction with eosinophilia and systemic symptoms) secondary to phenytoin; and in relation to them, the diagnosis and the treatment of these processes are discussed and reviewed. The AGEP (acute generalised exanthematous pustulosis) is also reviewed. The aetiological diagnosis of severe non-immediate reactions is difficult, and the value of current allergological testing is not well defined in these cases. Diagnosis is based on clinical history, the empirical risk of drugs to trigger SJS/TEN or DRESS, and the in vivo and in vitro testing of the suspect drug. Skin biopsy confirms that the clinical diagnosis and delayed hypersensitivity tests, especially the patch test and the lymphoblastic transformation test (LTT), may be important to confirm the aetiological diagnosis, in our cases emphasising the latter. These diseases can be life threatening (especially DRESS and TEN) and/or have a high rate of major complications or sequelae (SJS/TEN). The three cases described progressed well without sequelae. All were treated with corticosteroids, which is the most currently accepted treatment although the effect has not been clearly demonstrated. Copyright © 2015 SEICAP. Published by Elsevier Espana. All rights reserved.

  15. 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

  16. Small-Magnitude Effect Sizes in Epigenetic End Points are Important in Children's Environmental Health Studies: The Children's Environmental Health and Disease Prevention Research Center's Epigenetics Working Group.

    Science.gov (United States)

    Breton, Carrie V; Marsit, Carmen J; Faustman, Elaine; Nadeau, Kari; Goodrich, Jaclyn M; Dolinoy, Dana C; Herbstman, Julie; Holland, Nina; LaSalle, Janine M; Schmidt, Rebecca; Yousefi, Paul; Perera, Frederica; Joubert, Bonnie R; Wiemels, Joseph; Taylor, Michele; Yang, Ivana V; Chen, Rui; Hew, Kinjal M; Freeland, Deborah M Hussey; Miller, Rachel; Murphy, Susan K

    2017-04-01

    Characterization of the epigenome is a primary interest for children's environmental health researchers studying the environmental influences on human populations, particularly those studying the role of pregnancy and early-life exposures on later-in-life health outcomes. Our objective was to consider the state of the science in environmental epigenetics research and to focus on DNA methylation and the collective observations of many studies being conducted within the Children's Environmental Health and Disease Prevention Research Centers, as they relate to the Developmental Origins of Health and Disease (DOHaD) hypothesis. We address the current laboratory and statistical tools available for epigenetic analyses, discuss methods for validation and interpretation of findings, particularly when magnitudes of effect are small, question the functional relevance of findings, and discuss the future for environmental epigenetics research. A common finding in environmental epigenetic studies is the small-magnitude epigenetic effect sizes that result from such exposures. Although it is reasonable and necessary that we question the relevance of such small effects, we present examples in which small effects persist and have been replicated across populations and across time. We encourage a critical discourse on the interpretation of such small changes and further research on their functional relevance for children's health. The dynamic nature of the epigenome will require an emphasis on future longitudinal studies in which the epigenome is profiled over time, over changing environmental exposures, and over generations to better understand the multiple ways in which the epigenome may respond to environmental stimuli.

  17. Delayed photon selfinterference

    International Nuclear Information System (INIS)

    Kessel', A.R.; Moiseev, S.A.

    1993-01-01

    Delayed photon selfinterference on a sample containing resonant two-level atoms is considered when the difference in the lengths in two optical paths exceeds the photon 'length'. It is shown that a reading pulse of the electromagnetic field can induce photon echo

  18. Estimating Delays In ASIC's

    Science.gov (United States)

    Burke, Gary; Nesheiwat, Jeffrey; Su, Ling

    1994-01-01

    Verification is important aspect of process of designing application-specific integrated circuit (ASIC). Design must not only be functionally accurate, but must also maintain correct timing. IFA, Intelligent Front Annotation program, assists in verifying timing of ASIC early in design process. This program speeds design-and-verification cycle by estimating delays before layouts completed. Written in C language.

  19. Delays of Interconnected Flows

    Science.gov (United States)

    Sorger, U.; Suchanecki, Z.

    2011-07-01

    A rigorous approach to flows of particles in networks is presented. Under the assumption of independence of the transversal flows the asymptotic distributions of inter-delay times between particles are shown to be log-normal. In the case of dependent transversal traffic the ARCH and GARCH time series models, as well as martingale approach, have been applied.

  20. Plasmas for Transition Delay

    NARCIS (Netherlands)

    Kotsonis, M.; Boon, P.; Veldhuis, L.

    2009-01-01

    This paper describes the experimental investigation of the properties of Dielectric Barrier Discharge (DBD) actuators aimed at transition delay techniques. A wide range of geometrical configurations are tested as well as several electrical operational conditions. For the majority of the measurements

  1. 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.

  2. Delay decomposition approach to stability analysis for uncertain fuzzy Hopfield neural networks with time-varying delay

    Science.gov (United States)

    Balasubramaniam, P.; Chandran, R.

    2011-04-01

    This paper is concerned with delay-dependent stability analysis for uncertain Tagaki-Sugeno (T-S) fuzzy Hopfield neural networks (UFHNNs) with time-varying delay. By decomposing the delay interval into multiple equidistant subintervals, Lyapunov-Krasovskii functionals (LKFs) are constructed on these intervals. Employing these LKFs, a new stability criterion is proposed in terms of Linear Matrix Inequalities (LMIs), which is dependent on the size of the time delay and can be easily verified by MATLAB LMI toolbox. Numerical examples are given to illustrative the effectiveness of the proposed method.

  3. Towards a highly-efficient fuel-cell catalyst: optimization of Pt particle size, supports and surface-oxygen group concentration.

    Science.gov (United States)

    Muthuswamy, Navaneethan; de la Fuente, Jose Luis Gomez; Ochal, Piotr; Giri, Rajiv; Raaen, Steinar; Sunde, Svein; Rønning, Magnus; Chen, De

    2013-03-21

    In the present work, methanol oxidation reaction was investigated on Pt particles of various diameters on carbon-nanofibers and carbon-black supports with different surface-oxygen concentrations, aiming for a better understanding of the relationship between the catalyst properties and the electrochemical performance. The pre-synthesized Pt nanoparticles in ethylene glycol, prepared by the polyol method without using any capping agents, were deposited on different carbon supports. Removal of oxygen-groups from the carbon supports had profound positive effects on not only the Pt dispersion but also the specific activity. The edge structures on the stacked graphene sheets in the platelet carbon-nanofibers provided a strong interaction with the Pt particles, significantly reconstructing them in the process. Such reconstruction resulted in the formation of more plated Pt particles on the CNF than on the carbon-black and exposure of more Pt atoms with relatively high co-ordination numbers, and thereby higher specific activity. Owing to the combined advantages of optimum Pt particle diameter, an oxygen-free surface and the unique properties of CNFs, Pt supported on heat-treated CNFs exhibited a higher mass activity twice of that of its commercial counterpart.

  4. Measuring specific, rather than generalized, cognitive deficits and maximizing between-group effect size in studies of cognition and cognitive change.

    Science.gov (United States)

    Silverstein, Steven M

    2008-07-01

    While cognitive impairment in schizophrenia is easy to demonstrate, it has been much more difficult to measure a specific cognitive process unconfounded by the influence of other cognitive processes and noncognitive factors (eg, sedation, low motivation) that affect test scores. With the recent interest in the identification of neurophysiology-linked cognitive probes for clinical trials, the issue of isolating specific cognitive processes has taken on increased importance. Recent advances in research design and psychometric theory regarding cognition research in schizophrenia demonstrate the importance of (1) maximizing between-group differences via reduction of measurement error during both test development and subsequent research and (2) the development and use of process-specific tasks in which theory-driven performance indices are derived across multiple conditions. Use of these 2 strategies can significantly advance both our understanding of schizophrenia and measurement sensitivity for clinical trials. Novel data-analytic strategies for analyzing change across multiple conditions and/or multiple time points also allow for increased reliability and greater measurement sensitivity than traditional strategies. Following discussion of these issues, trade-offs inherent to attempts to address psychometric issues in schizophrenia research are reviewed. Finally, additional considerations for maximizing sensitivity and real-world significance in clinical trials are discussed.

  5. Density matrix renormalization group simulations of SU(N ) Heisenberg chains using standard Young tableaus: Fundamental representation and comparison with a finite-size Bethe ansatz

    Science.gov (United States)

    Nataf, Pierre; Mila, Frédéric

    2018-04-01

    We develop an efficient method to perform density matrix renormalization group simulations of the SU(N ) Heisenberg chain with open boundary conditions taking full advantage of the SU(N ) symmetry of the problem. This method is an extension of the method previously developed for exact diagonalizations and relies on a systematic use of the basis of standard Young tableaux. Concentrating on the model with the fundamental representation at each site (i.e., one particle per site in the fermionic formulation), we have benchmarked our results for the ground-state energy up to N =8 and up to 420 sites by comparing them with Bethe ansatz results on open chains, for which we have derived and solved the Bethe ansatz equations. The agreement for the ground-state energy is excellent for SU(3) (12 digits). It decreases with N , but it is still satisfactory for N =8 (six digits). Central charges c are also extracted from the entanglement entropy using the Calabrese-Cardy formula and agree with the theoretical values expected from the SU (N) 1 Wess-Zumino-Witten conformal field theories.

  6. Measurements of benzene and formaldehyde in a medium sized urban environment. Indoor/outdoor health risk implications on special population groups.

    Science.gov (United States)

    Pilidis, Georgios A; Karakitsios, Spyros P; Kassomenos, Pavlos A; Kazos, Elias A; Stalikas, Constantine D

    2009-03-01

    In the present study, the results of a measurement campaign aiming to assess cancer risk among two special groups of population: policemen and laboratory technicians exposed to the toxic substances, benzene and formaldehyde are presented. The exposure is compared to general population risk. The results show that policemen working outdoor (traffic regulation, patrol on foot or in vehicles, etc.) are exposed at a significantly higher benzene concentration (3-5 times) than the general population, while the exposure to carbonyls is in general lower. The laboratory technicians appear to be highly exposed to formaldehyde while no significant variation of benzene exposure in comparison to the general population is recorded. The assessment revealed that laboratory technicians and policemen run a 20% and 1% higher cancer risk respectively compared to the general population. Indoor working place air quality is more significant in assessing cancer risk in these two categories of professionals, due to the higher Inhalation Unit Risk (IUR) of formaldehyde compared to benzene. Since the origin of the danger to laboratory technicians is clear (use of chemicals necessary for the experiments), in policemen the presence of carbonyls in indoor air concentrations due to smoking or used materials constitute a danger equal to the exposure to traffic originated air pollutants.

  7. Reversing the Signaled Magnitude Effect in Delayed Matching to Sample: Delay-Specific Remembering?

    Science.gov (United States)

    White, K. Geoffrey; Brown, Glenn S.

    2011-01-01

    Pigeons performed a delayed matching-to-sample task in which large or small reinforcers for correct remembering were signaled during the retention interval. Accuracy was low when small reinforcers were signaled, and high when large reinforcers were signaled (the signaled magnitude effect). When the reinforcer-size cue was switched from small to…

  8. 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...

  9. Accelerating Smaller Cutbacks to Delay Larger Ones?

    DEFF Research Database (Denmark)

    Tepe, Markus; Vanhuysse, Pieter

    2012-01-01

    This chapter investigates the politics of delays in pension generosity cutbacks in 18 OECD democracies between 1981 and 1999 by using event history analysis. In the context of fiscal austerity, policymakers are assumed to have a strong incentive to manipulate the timing of cutbacks strategically...... rigidity) contribute to explain the timing of cutbacks. While the latter two factors are found not to have any significant effect on the timing of pension generosity cutbacks, more rightleaning governments tend to implement pension generosity cutbacks significantly earlier. Finally, we find almost mirror...... 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...

  10. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  11. 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.

  12. Risk Factors for Delayed Extubation after Ventricular Septal Defect Closure: a Prospective Observational Study

    Directory of Open Access Journals (Sweden)

    Divyakant Parmar

    Full Text Available Objective: The objective of our study was to determine the feasibility of early extubation and to identify the risk factors for delayed extubation in pediatric patients operated for ventricular septal defect closure. Methods: A prospective, observational study was carried out at our Institute. This study involved consecutive 135 patients undergoing ventricular septal defect closure. Patients were extubated if feasible within six hours after surgery. Based on duration of extubation, patients were divided two groups: Group 1= extubation time ≤ 6 hours, Group 2= extubation time >6 hours. Results: A total of 99 patients were in Group 1 and 36 patients in Group 2. Duration of ventilation was 4.4±0.9 hours in Group 1 and 25.9±24.9 hours in Group 2 (P<0.001. Univariate analysis showed that young age, low weight, low partial pressure of oxygen, trisomy 21, multiple ventricular septal defect, high vasoactive inotropic score, transient heart block and low cardiac output syndrome were associated with delayed extubation. However, regression analysis revealed that only trisomy 21 (OR: 0.248; 95%CI: 0.176-0.701; P=0.001, low cardiac output syndrome (OR: 0.291; 95%CI: 0.267-0.979; P=0.001, multiple ventricular septal defect (OR: 0.243; 95%CI: 0.147-0.606; P=0.002 and vasoactive inotropic score (OR: 0.174 95%CI: 0.002-0.062; P=0.039 are strongest predictors for delayed extubation. Conclusion: Trisomy 21, low cardiac output syndrome, multiple ventricular septal defect and high vasoactive inotropic score are significant risk factors for delay in extubation. Age, weight, pulmonary artery hypertension, size of ventricular septal defect, aortic cross-clamp and cardiopulmonary bypass time did not affect early extubation.

  13. Delayed auditory feedback and aphasia.

    Science.gov (United States)

    Boller, F; Vrtunski, P B; Kim, Y; Mack, J L

    1978-06-01

    The effect of Delayed Auditory Feedback (DAF) was evaluated in three groups of subjects: 10 normal controls, 10 non-fluent aphasics, and 10 fluent aphasics. Speec production tasks consisted of (1) repeating sound and words; (2) naming objects; (3) producing sentences from given stimulus words; (4) answering questions; (5) reciting nursery rhymes; and (6) reading. Two delays were used, 180 and 360 msec. Two independent judges rated patients' responses for changes in intensity, duration, and quality of speech. Inter-judge reliability was considered satisfactory. Contrary to some previous reports, all subjects, including all the fluent aphasics, showed some DAF effect. Fluent aphasics, however, showed a significantly smaller DAF effect than non-fluent aphasics. Patient with conduction aphasia appeared to be the least impaired. Overall DAF effect was greater with 180 msec. than with 360 msec. The largest DAF effect occurred during answering question, followed by repeating, reading, nursery rhymes, sentence production, and naming, in that order. Repetition of a complex word produced a greater DAF effect than repetition of a simple sound. Finally, we found a differential effect of DAF on the three measures used in the study. We hypothesize that DAF effects result from changes in two separate monitoring systems. One systems is related to changes in the intensity of speech and does not appear to be affected by aphasia. The other is responsible for duration and qualitative changes in speech and is differentially affected in relation to pathology producing aphasia.

  14. Oncoplastic breast surgery does not delay the onset of adjuvant chemotherapy: a population-based study.

    Science.gov (United States)

    Klit, Anders; Tvedskov, Tove Filtenborg; Kroman, Niels; Elberg, Jens Jørgen; Ejlertsen, Bent; Henriksen, Trine Foged

    2017-05-01

    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. 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. 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), the time from surgery to onset of adjuvant chemotherapy, nor total time from biopsy to the onset of adjuvant chemotherapy (mean time 52.7, 51.9 and 53.2 days, respectively). Our study shows that oncoplastic breast surgery does not delay the onset of adjuvant chemotherapy in comparison with mastectomy and lumpectomy. Accordingly, patients should not be excluded from treatment with oncoplastic breast surgery due to concerns of delay in adjuvant chemotherapy.

  15. 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.

  16. Delayed Speech or Language Development

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Delayed Speech or Language Development KidsHealth / For Parents / Delayed Speech ... their child is right on schedule. How Are Speech and Language Different? Speech is the verbal expression ...

  17. Delayed antibiotic prescriptions for respiratory infections.

    Science.gov (United States)

    Spurling, Geoffrey Kp; Del Mar, Chris B; Dooley, Liz; Foxlee, Ruth; Farley, Rebecca

    2017-09-07

    Concerns exist regarding antibiotic prescribing for respiratory tract infections (RTIs) owing to adverse reactions, cost, and antibacterial resistance. One proposed strategy to reduce antibiotic prescribing is to provide prescriptions, but to advise delay in antibiotic use with the expectation that symptoms will resolve first. This is an update of a Cochrane Review originally published in 2007, and updated in 2010 and 2013. To evaluate the effects on clinical outcomes, antibiotic use, antibiotic resistance, and patient satisfaction of advising a delayed prescription of antibiotics in respiratory tract infections. For this 2017 update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 4, 2017), which includes the Cochrane Acute Respiratory Infection Group's Specialised Register; Ovid MEDLINE (2013 to 25 May 2017); Ovid Embase (2013 to 2017 Week 21); EBSCO CINAHL Plus (1984 to 25 May 2017); Web of Science (2013 to 25 May 2017); WHO International Clinical Trials Registry Platform (1 September 2017); and ClinicalTrials.gov (1 September 2017). Randomised controlled trials involving participants of all ages defined as having an RTI, where delayed antibiotics were compared to immediate antibiotics or no antibiotics. We defined a delayed antibiotic as advice to delay the filling of an antibiotic prescription by at least 48 hours. We considered all RTIs regardless of whether antibiotics were recommended or not. We used standard Cochrane methodological procedures. Three review authors independently extracted and collated data. We assessed the risk of bias of all included trials. We contacted trial authors to obtain missing information. For this 2017 update we added one new trial involving 405 participants with uncomplicated acute respiratory infection. Overall, this review included 11 studies with a total of 3555 participants. These 11 studies involved acute respiratory infections including acute otitis media (three studies

  18. Delayed Macular Hole Closure

    Directory of Open Access Journals (Sweden)

    Peter Distelmaier

    2014-04-01

    Full Text Available Purpose: The presented case raises questions regarding the favorable scheduling of planned postoperative care and the ideal observation interval to decide for reoperations in macular hole surgery. Furthermore a discussion about the use of short- and long-acting gas tamponades in macular hole surgery is encouraged. Methods: We present an interventional case report and a short review of the pertinent literature. Results: We report a case of spontaneous delayed macular hole closure after vitreoretinal surgery had been performed initially without the expected success. A 73-year-old male Caucasian patient presented at our clinic with a stage 2 macular hole in his left eye. He underwent 23-gauge pars plana vitrectomy and internal limiting membrane peeling with a 20% C2F6-gas tamponade. Sixteen days after the procedure, an OCT scan revealed a persistent stage 2 macular hole, and the patient was scheduled for reoperation. Surprisingly, at the date of planned surgery, which was another 11 days later, the macular hole had resolved spontaneously without any further intervention. Conclusions: So far no common opinion exists regarding the use of short- or long-acting gas in macular hole surgery. Our case of delayed macular hole closure after complete resorption of the gas tamponade raises questions about the need and duration of strict prone positioning after surgery. Furthermore short-acting gas might be as efficient as long-acting gas. We suggest to wait with a second intervention at least 4 weeks after the initial surgery, since a delayed macular hole closure is possible.

  19. group sizes of oribis in different habitats

    African Journals Online (AJOL)

    1991-07-05

    Jul 5, 1991 ... (Cnidaria: Limnomedusae) from southern Africa. Nancy A. Rayner * and C.C. Appleton. Department of Zoology & Entomology, University of Natal,. P.O. Box 375, Pietermaritzburg, 3200 Republic of South. Africa. Received 27 January 1992; accepted 9 March 1992. The northern hemisphere Craspedacusta ...

  20. Organophosphate induced delayed polyneuropathy.

    Science.gov (United States)

    Qureshi, Asif; Ali, Rajab; Yaqoob, M Yousuf; Saleem, Omema

    2007-07-01

    Organophosphate induced delayed polyneuropathy (OPIDP) is a rare sensory-motor distal axonopathy, which usually occur after ingestion of large doses of certain organophosphate insecticide. The clinical picture is characterized by the distal paresis in lower limb associated with sensory symptoms. Electrodiagnostic studies show a motor axonal neuropathy. This case occurred in a 14 years old girl who developed cramping pain in both calves associated with lower limbs paresis 6 weeks after accidental organophosphate poisoning. After another week, she also developed weakness in both hands. Electrophysiological study was characterized by an axonal polyneuropathy pattern. Patient improved upon oral multivitamin therapy and physiotherapy.

  1. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...

  2. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical......Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  3. 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.

  4. Patient delay in cancer studies

    DEFF Research Database (Denmark)

    Andersen, Rikke Sand; Vedsted, Peter; Olesen, Frede

    2009-01-01

    BACKGROUND: There is no validated way of measuring the prevalence and duration of patient delay, and we do not know how people perceive and define the time intervals they are asked to report in patient delay studies. This lack of a validated measure hampers research in patient delay...... as symptoms related to a specific cancer diagnosis is embedded within a social and cultural context. We therefore cannot assume that respondents define delay periods in identical ways. SUMMARY: In order to improve the validity of patient delay studies, it is suggested that research be strengthened on three...

  5. Can the Onset of Type 2 Diabetes Be Delayed by a Group-Based Lifestyle Intervention in Women with Prediabetes following Gestational Diabetes Mellitus (GDM? Findings from a Randomized Control Mixed Methods Trial

    Directory of Open Access Journals (Sweden)

    Angela O’Dea

    2015-01-01

    Full Text Available Objective. To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM. Design. A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n=24 or wait control (n=26 and postintervention qualitative interviews with participants. Main Outcome Measures. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG from study entry to one-year follow-up. Results. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Conclusions. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

  6. Delay Discounting in Current and Former Marijuana-Dependent Individuals

    OpenAIRE

    Johnson, Matthew W.; Bickel, Warren K.; Baker, Forest; Moore, Brent A.; Badger, Gary J.; Budney, Alan J.

    2010-01-01

    Studies have found that a variety of drug dependent groups discount delayed rewards more than matched-controls. This study compared delay discounting for a hypothetical $1000 reward among dependent marijuana users, former dependent marijuana users, and matched-controls. Discounting of marijuana was also assessed in the currently marijuana-dependent group. No significant difference in discounting was detected among the groups, however currently dependent users showed a trend to discount money ...

  7. Epidemiology of delayed ejaculation.

    Science.gov (United States)

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea; Jannini, Emmanuele A

    2016-08-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

  8. Ataxia telangiectasia: presentation and diagnostic delay.

    Science.gov (United States)

    Devaney, Rebecca; Pasalodos, Sara; Suri, Mohnish; Bush, Andy; Bhatt, Jayesh M

    2017-04-01

    Ataxia telangiectasia (A-T) is a rare progressive, multisystem genetic disease. Families of children with ultra-rare diseases often experience significant diagnostic delays. We reviewed the diagnostic process for A-T in order to identify causes of delay in an attempt to facilitate earlier identification of A-T in the future. A retrospective case note review of 79 children at the National Paediatric A-T clinic seen since May 2009. Data were collected on the nature and age of initial symptoms, the age at first presentation, measurement of alpha feto-protein (AFP) and age of genetic diagnostic confirmation. At presentation, 71 children (90%) had ataxia. The median presentation delay (from first parental concern to presentation) was 8 months (range 0-118 months), and the median diagnostic delay (genetic confirmation of diagnosis) was 12 months (range 1-109 months). There are significant delays in presentation and diagnostic confirmation of A-T. A greater awareness of A-T and early measurement of AFP may help to improve this. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. 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)

  10. Analyzing Double Delays at Newark Liberty International Airport

    Science.gov (United States)

    Evans, Antony D.; Lee, Paul

    2016-01-01

    When weather or congestion impacts the National Airspace System, multiple different Traffic Management Initiatives can be implemented, sometimes with unintended consequences. One particular inefficiency that is commonly identified is in the interaction between Ground Delay Programs (GDPs) and time based metering of internal departures, or TMA scheduling. Internal departures under TMA scheduling can take large GDP delays, followed by large TMA scheduling delays, because they cannot be easily fitted into the overhead stream. In this paper we examine the causes of these double delays through an analysis of arrival operations at Newark Liberty International Airport (EWR) from June to August 2010. Depending on how the double delay is defined between 0.3 percent and 0.8 percent of arrivals at EWR experienced double delays in this period. However, this represents between 21 percent and 62 percent of all internal departures in GDP and TMA scheduling. A deep dive into the data reveals that two causes of high internal departure scheduling delays are upstream flights making up time between their estimated departure clearance times (EDCTs) and entry into time based metering, which undermines the sequencing and spacing underlying the flight EDCTs, and high demand on TMA, when TMA airborne metering delays are high. Data mining methods (currently) including logistic regression, support vector machines and K-nearest neighbors are used to predict the occurrence of double delays and high internal departure scheduling delays with accuracies up to 0.68. So far, key indicators of double delay and high internal departure scheduling delay are TMA virtual runway queue size, and the degree to which estimated runway demand based on TMA estimated times of arrival has changed relative to the estimated runway demand based on EDCTs. However, more analysis is needed to confirm this.

  11. Size reduction techniques for vital compliant VHDL simulation models

    Science.gov (United States)

    Rich, Marvin J.; Misra, Ashutosh

    2006-08-01

    A method and system select delay values from a VHDL standard delay file that correspond to an instance of a logic gate in a logic model. Then the system collects all the delay values of the selected instance and builds super generics for the rise-time and the fall-time of the selected instance. Then, the system repeats this process for every delay value in the standard delay file (310) that correspond to every instance of every logic gate in the logic model. The system then outputs a reduced size standard delay file (314) containing the super generics for every instance of every logic gate in the logic model.

  12. 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.

  13. 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.

  14. Survey of time preference, delay discounting models

    Directory of Open Access Journals (Sweden)

    John R. Doyle

    2013-03-01

    Full Text Available The paper surveys over twenty models of delay discounting (also known as temporal discounting, time preference, time discounting, that psychologists and economists have put forward to explain the way people actually trade off time and money. Using little more than the basic algebra of powers and logarithms, I show how the models are derived, what assumptions they are based upon, and how different models relate to each other. Rather than concentrate only on discount functions themselves, I show how discount functions may be manipulated to isolate rate parameters for each model. This approach, consistently applied, helps focus attention on the three main components in any discounting model: subjectively perceived money; subjectively perceived time; and how these elements are combined. We group models by the number of parameters that have to be estimated, which means our exposition follows a trajectory of increasing complexity to the models. However, as the story unfolds it becomes clear that most models fall into a smaller number of families. We also show how new models may be constructed by combining elements of different models. The surveyed models are: Exponential; Hyperbolic; Arithmetic; Hyperboloid (Green and Myerson, Rachlin; Loewenstein and Prelec Generalized Hyperboloid; quasi-Hyperbolic (also known as beta-delta discounting; Benhabib et al's fixed cost; Benhabib et al's Exponential / Hyperbolic / quasi-Hyperbolic; Read's discounting fractions; Roelofsma's exponential time; Scholten and Read's discounting-by-intervals (DBI; Ebert and Prelec's constant sensitivity (CS; Bleichrodt et al.'s constant absolute decreasing impatience (CADI; Bleichrodt et al.'s constant relative decreasing impatience (CRDI; Green, Myerson, and Macaux's hyperboloid over intervals models; Killeen's additive utility; size-sensitive additive utility; Yi, Landes, and Bickel's memory trace models; McClure et al.'s two exponentials; and Scholten and Read's trade

  15. Transfer delay audit.

    Science.gov (United States)

    Alraqi, S; Coughlan, R

    2007-05-01

    The purpose was to determine the average transfer time taken for acute patients to arrive to the medical unit from the time of referral by an A/E officer. We included the first 200 consecutive patients with completed records. 86 were men and 114 women, aged between 14 and 96 years. Transfer time was calculated as the difference from the time of referral by the A/E officer in UCHG to the time of arrival to the medical unit in MPH. The average transfer time for all patients was 91.5 minutes. The longest was in the second (17:00-24:00) interval with a mean of 105 minutes. 26.5% of patients arrived later than 2 hours after referral. Our findings confirm the existence of unacceptably long transfer time for a significant number of patients. Causes for this delay should be searched for to help find and implement solutions.

  16. Delay tolerant networks

    CERN Document Server

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  17. 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.

  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. 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.

  20. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported......When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new...

  1. Relationship of Reaction Time to Perception of a Stimulus and Volitionally Delayed Response.

    Science.gov (United States)

    Meador, Kimford J; Boyd, Alan; Loring, David W

    2017-06-01

    Initiation of response in a simple reaction time (RT) task may precede conscious perception of the stimulus. Since volitionally delayed responses may require conscious perception of the stimulus before response initiation, it has been hypothesized that volitionally delayed responses will markedly delay RT. We conducted two experiments with separate groups of healthy volunteers (n=16; n=13) who performed computerized simple and choice RT tasks. In the standard condition, we instructed the participants to respond to a visual stimulus by pushing a button as quickly as possible. In the second condition, we instructed the participants to respond after a slight volitional delay. The second experiment had an additional volitional delay condition in which we asked participants to delay their responses by an estimated 50% above their usual standard response. We found marked delays and increased variability when participants volitionally delayed their responses, averaging 322 ms for standard and 861 ms for delayed simple RTs (267% increase), and 650 ms for standard and 1018 ms for delayed choice RTs (157% increase). Effects did not differ across age, sex, or handedness. However, a minority of participants did not meaningfully delay their RT during the volitional delay conditions. On average, participants had marked delays when they tried to delay their responses slightly, but a subset of participants exhibited essentially no delay despite trying to delay. We suggest some potential mechanisms that future investigations might delineate.

  2. Control systems with network delay

    OpenAIRE

    Şabanoviç, Asif; Sabanovic, Asif; Ohnishi, Kouhei; Yashiro, Daisuke; Acer, Merve; Ş.-Behliloviç, Nadira; S.-Behlilovic, Nadira

    2009-01-01

    In this paper motion control systems with delay in measurement and control channels are discussed and a new structure of the observer-predictor is proposed. The feature of the proposed system is enforcement of the convergence in both the estimation and the prediction of the plant output in the presence of the variable, unknown delay in both measurement and in the control channels. The estimation is based on the available data – undelayed control input, the delayed measurement of position o...

  3. PRECISION TIME-DELAY CIRCUIT

    Science.gov (United States)

    Creveling, R.

    1959-03-17

    A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

  4. 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

  5. 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

  6. 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

  7. A modified thromboembolic stroke model of rat suitable for the delayed thrombolytic therapy

    International Nuclear Information System (INIS)

    You Xiaofang; Li Minghua; Zhao Jungong; Li Yongdong; Cheng Yingsheng

    2007-01-01

    Objective: To develop a modified focal thromboembolic stroke model of rat suitable for the delayed thrombolytic therapy. Methods: Ten fibrin-rich autologous blood clots (0.8-1.0 mm in length, 0.35 mm in width) were injected into the internal carotid artery to establish a focal thromboembolic stroke model. 138 embolized rats were divided randomly into ischemic group (n=68) and delayed thrombolytic therapeutic group (n=70). At 3 h, 6 h and 9 h after embolization, the rats in delayed thrombolytic therapeutic group were treated with 10 mg/kg recombinant tissue plasminogen activator respectively, while no treatment was performed on ischemic group. Lesion size, location, relative cerebral blood flow volume at different time, and intracranial hemorrhage after treatment were evaluated by MRI. After the last MRI examination, the rats were decapitated and their brain tissue were fixed with formalin for further pathology study. Results: Embolization with a preformed clot resulted in a focal infarction in the territory supplied by the MCA branch or anterior choroid artery, including 79.4% (104/131) of infarction located in ipsilateral parietal cortex or /and audoputamen, with infarction volume of (23.12 ± 6.04)% in embolized hemisphere. At 3 h, 6 h, and 9 h after embolization, the relative cerebral blood flow volumes were (36.86 ± 16.02)%, (40.67 ± 25.91)% and (44.72 ± 26.51)% respectively, with no statistical difference between them (3 h vs 6 h, Z=- 0.958, P=0.338, 3 h vs 9 h, Z=- 1.147, P=0.251). Hemorrhage was observed in 12 rats, all of that were in delayed thrombolytic therapeutic group. 13 rats died within 24 hours and 3 died within 12 days after delayed thrombolytic therapy. Conclusion: The modified rat thromboembolic brain model is reliable and repeaducible closely mimicking that of the human middle cerebral arterial branch thrombosis, suitable for investigating the delayed thrombolytic therapy in rats. (authors)

  8. 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.

  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. Sustainable Sizing.

    Science.gov (United States)

    Robinette, Kathleen M; Veitch, Daisy

    2016-08-01

    To provide a review of sustainable sizing practices that reduce waste, increase sales, and simultaneously produce safer, better fitting, accommodating products. Sustainable sizing involves a set of methods good for both the environment (sustainable environment) and business (sustainable business). Sustainable sizing methods reduce (1) materials used, (2) the number of sizes or adjustments, and (3) the amount of product unsold or marked down for sale. This reduces waste and cost. The methods can also increase sales by fitting more people in the target market and produce happier, loyal customers with better fitting products. This is a mini-review of methods that result in more sustainable sizing practices. It also reviews and contrasts current statistical and modeling practices that lead to poor fit and sizing. Fit-mapping and the use of cases are two excellent methods suited for creating sustainable sizing, when real people (vs. virtual people) are used. These methods are described and reviewed. Evidence presented supports the view that virtual fitting with simulated people and products is not yet effective. Fit-mapping and cases with real people and actual products result in good design and products that are fit for person, fit for purpose, with good accommodation and comfortable, optimized sizing. While virtual models have been shown to be ineffective for predicting or representing fit, there is an opportunity to improve them by adding fit-mapping data to the models. This will require saving fit data, product data, anthropometry, and demographics in a standardized manner. For this success to extend to the wider design community, the development of a standardized method of data collection for fit-mapping with a globally shared fit-map database is needed. It will enable the world community to build knowledge of fit and accommodation and generate effective virtual fitting for the future. A standardized method of data collection that tests products' fit methodically

  11. High resolution digital delay timer

    Science.gov (United States)

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  12. System delays in breast cancer

    African Journals Online (AJOL)

    we notice a discrepancy in incidence rates between various ethnic/race .... Thailand. 180. 2. 3. 5 to diagnosis NOT treatment‡. This study. South Africa 45. -. 2.5. 3. 1.25. 3. -. 10. *Total delay refers to totals for available datasets and not necessarily mean delay to treatment/surgery commencement. †Montella et al. presented ...

  13. Magnetic bearing optical delay line

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in close cooperation with Micromega-Dynamics and Dutch Space, has developed an advanced Optical Delay Line (ODL) for use in PRIMA, GENIE and other ground based interferometers. The delay line design is modular and flexible, which makes scaling for other applications a relatively easy task.

  14. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  15. Picosecond resolution programmable delay line

    International Nuclear Information System (INIS)

    Suchenek, Mariusz

    2009-01-01

    The note presents implementation of a programmable delay line for digital signals. The tested circuit has a subnanosecond delay range programmable with a resolution of picoseconds. Implementation of the circuit was based on low-cost components, easily available on the market. (technical design note)

  16. Socioeconomic disadvantage and developmental delay among US children aged 18 months to 5 years.

    Science.gov (United States)

    Simon, Alan E; Pastor, Patricia N; Avila, Rosa M; Blumberg, Stephen J

    2013-08-01

    Few studies have examined the relationship between sociodemographic factors and a population-based measure of developmental delay in US children. We identify sociodemographic factors associated with unlikely, probable and possible developmental delay in preschool US children using nationally representative data. All children aged 18 months to 5 years in the 2007 National Survey of Children's Health were categorised into three groups based on the likelihood of developmental delay (unlikely delay, possible delay and probable delay) using a modified survey version of the Parents' Evaluation of Developmental Status questionnaire. Bivariate and multivariate multinomial logistic regressions were used to assess relations between sociodemographic variables and risk of developmental delay. Children had increased odds of probable delay (compared with unlikely delay) if they were older (adjusted OR (aOR)=1.41/additional year above the youngest age group (18 months-2 years), pincome (aOR=1.33 for each decreasing category of poverty level, p10 h/week of care at another family's home (aOR=1.71, p<0.05). Only four characteristics (being older, male, low birth weight and Hispanic living in a non-English-speaking household) were associated with increased odds of possible delay compared with unlikely delay. Multiple factors, including demographic characteristics and indicators of social disadvantage, distinguish children with probable developmental delay from those unlikely to have developmental delay. Fewer factors identify children with possible delay.

  17. 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.

  18. Exploring Size.

    Science.gov (United States)

    Brand, Judith, Ed.

    1995-01-01

    "Exploring" is a magazine of science, art, and human perception that communicates ideas museum exhibits cannot demonstrate easily by using experiments and activities for the classroom. This issue concentrates on size, examining it from a variety of viewpoints. The focus allows students to investigate and discuss interconnections among…

  19. Size matter!

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Jespersen, Andreas Maaløe; Skov, Laurits Rhoden

    2015-01-01

    the hypothesis that a decrease in the size of food plates may lead to significant reductions in food waste from buffets. It supports and extends the set of circumstances in which a recent experiment found that reduced dinner plates in a hotel chain lead to reduced quantities of leftovers....

  20. Delayed radiation neuropathy

    International Nuclear Information System (INIS)

    Nagashima, Toshiko; Miyamoto, Kazuto; Beppu, Hirokuni; Hirose, Kazuhiko; Yamada, Katsuhiro

    1981-01-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  1. Delayed radiation neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  2. The effects of delay duration on visual working memory for orientation.

    Science.gov (United States)

    Shin, Hongsup; Zou, Qijia; Ma, Wei Ji

    2017-12-01

    We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.

  3. 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.

  4. 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)

  5. Consonant and syllable complexity of toddlers with Down syndrome and mixed-aetiology developmental delays.

    Science.gov (United States)

    Sokol, Shari B; Fey, Marc E

    2013-12-01

    This study examines whether speech sound production of toddlers with Down syndrome (DS) is on par with or more severely impaired than that of mental age (MA) peers with developmental delay due to aetiologies other than Down syndrome at two points within an 18-month period near the onset of spoken word production. The utterances of 26 children with DS, aged 24-33 months, with a mean MA of 14.3 months, originally studied by Fey et al. and Warren et al. were compared to those of a group of 22 children with similar intellectual and communication delay but no DS (NDS). Phonological measures included the size of the consonant inventory, syllable shape complexity, and number of communication acts with canonical vocalizations. At Time 1, the DS group performed as well as or better than the NDS group on these measures of speech production. At Time 2, 18 months later, the DS group was behind the NDS group on the same measures. Results extended the pattern of more severe impairment in children with DS than NDS peers commonly noted in expressive language to measures of phonological development.

  6. 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.

  7. Group delay functions and its applications in speech technology

    Indian Academy of Sciences (India)

    respectively. The features that characterize the digital filter can be obtained directly from the spectrum or can be derived from the model. The source information may be derived by passing the speech signal through the inverse of the model system. The source and system become additive as in homomorphic processing, i.e.,.

  8. Group delay functions and its applications in speech technology

    Indian Academy of Sciences (India)

    Traditionally, the information in speech signals is represented in terms of features derived from short-time Fourier analysis. In this analysis the features extracted from the magnitude of the Fourier transform (FT) are considered, ignoring the phase component. Although the significance of the FT phase was highlighted in ...

  9. 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

  10. Postplacental insertion of the levonorgestrel intrauterine device after cesarean delivery vs. delayed insertion: a randomized controlled trial.

    Science.gov (United States)

    Whitaker, Amy K; Endres, Loraine K; Mistretta, Stephanie Q; Gilliam, Melissa L

    2014-06-01

    This trial was designed to compare levonorgestrel intrauterine device (LNG-IUD) use at 1 year after delivery between women randomized to postplacental insertion at the time of cesarean delivery and delayed insertion 4-8 weeks after delivery. This randomized controlled trial was conducted at two urban medical centers. Eligible pregnant women with planned cesarean deliveries were randomized to immediate postplacental insertion during cesarean or delayed insertion after 4-8 weeks. We used intention-to-treat analysis for the primary outcome of LNG-IUD use 12 months after delivery. Forty-two women were randomized, 20 into the postplacental group and 22 in the delayed group. Although confirmed use of the LNG-IUD 12 months after delivery was higher in the postplacental group (60.0% vs. 40.9%, p=.35), this difference was not statistically significance. Expulsion was significantly more common in the postplacental group (20.0% vs. 0%, p=.04). There were significant differences between the two sites in baseline population characteristics, follow-up and expulsion. The trial did not answer the intended question as it was halted early due to slow enrollment. Our results show higher expulsion after postplacental insertion compared to delayed insertion but suggest similar IUD use at 12 months. Moreover, it provides valuable lessons regarding a randomized controlled trial of postplacental LNG-IUD placement due to the challenges of estimating effect size and the nature of the population who might benefit from immediate insertion. Postplacental insertion of an IUD may improve use of highly effective contraception during the postpartum period. While our results suggest higher expulsion after postplacental insertion compared to delayed insertion and similar IUD use at 12 months, our trial was insufficient to definitively test our hypothesis. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Fractional delayed damped Mathieu equation

    Science.gov (United States)

    Mesbahi, Afshin; Haeri, Mohammad; Nazari, Morad; Butcher, Eric A.

    2015-03-01

    This paper investigates the dynamical behaviour of the fractional delayed damped Mathieu equation. This system includes three different phenomena (fractional order, time delay, parametric resonance). The method of harmonic balance is employed to achieve approximate expressions for the transition curves in the parameter plane. The n = 0 and n = 1 transition curves (both lower and higher order approximations) are obtained. The dependencies of these curves on the system parameters and fractional orders are determined. Previous results for the transition curves reported for the damped Mathieu equation, delayed second-order oscillator, and fractional Mathieu equation are confirmed as special cases of the results for the current system.

  12. Ergodic Interference Alignment with Delayed Feedback

    OpenAIRE

    Kang, Myung Gil; Choi, Wan

    2013-01-01

    We propose new ergodic interference alignment techniques for $K$-user interference channels with delayed feedback. Two delayed feedback scenarios are considered -- delayed channel information at transmitter (CIT) and delayed output feedback. It is proved that the proposed techniques achieve total $2K/(K+2)$ DoF which is higher than that by the retrospective interference alignment for the delayed feedback scenarios.

  13. 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

  14. Fractional variational principles with delay

    International Nuclear Information System (INIS)

    Baleanu, Dumitru; Abdeljawad, Thabet Maaraba; Jarad, Fahd

    2008-01-01

    The fractional variational principles within Riemann-Liouville fractional derivatives in the presence of delay are analyzed. The corresponding Euler-Lagrange equations are obtained and one example is analyzed in detail

  15. Linear rotary optical delay lines

    Science.gov (United States)

    Guerboukha, Hichem; Qu, Hang; Skorobogatiy, Maksim

    2016-03-01

    We present a semi-analytical solution for the design of a high-speed rotary optical delay line that use a combination of two rotating curvilinear reflectors. We demonstrate that it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating reflector surfaces. Moreover, a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, we present blades that fit into a circle of 10cm diameter. Finally, a prototype of a rotary delay line is fabricated using CNC machining, and its optical properties are characterized.

  16. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  17. Patterns of delayed marriage: how special are the Irish?

    Science.gov (United States)

    Schellenberg, J A

    1991-02-01

    "This paper deals with delayed marriage and singlehood among the Irish as a focus for the study of the persistence of ethnic characteristics. Patterns of delayed marriage in Ireland in the nineteenth and twentieth centuries are reviewed, and evidence is also presented that Irish persons in other countries (especially in the United States) continue to show significantly higher rates of singlehood and postponed marriage than persons of other nationality groups. Discussion includes how delayed marriage became common in Ireland during the past 150 years and what may be involved in the apparent persistence of this pattern today in Ireland and among the Irish in other countries." excerpt

  18. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  19. 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

  20. Rhizosphere size

    Science.gov (United States)

    Kuzyakov, Yakov; Razavi, Bahar

    2017-04-01

    Estimation of the soil volume affected by roots - the rhizosphere - is crucial to assess the effects of plants on properties and processes in soils and dynamics of nutrients, water, microorganisms and soil organic matter. The challenges to assess the rhizosphere size are: 1) the continuum of properties between the root surface and root-free soil, 2) differences in the distributions of various properties (carbon, microorganisms and their activities, various nutrients, enzymes, etc.) along and across the roots, 3) temporal changes of properties and processes. Thus, to describe the rhizosphere size and root effects, a holistic approach is necessary. We collected literature and own data on the rhizosphere gradients of a broad range of physico-chemical and biological properties: pH, CO2, oxygen, redox potential, water uptake, various nutrients (C, N, P, K, Ca, Mg, Mn and Fe), organic compounds (glucose, carboxylic acids, amino acids), activities of enzymes of C, N, P and S cycles. The collected data were obtained based on the destructive approaches (thin layer slicing), rhizotron studies and in situ visualization techniques: optodes, zymography, sensitive gels, 14C and neutron imaging. The root effects were pronounced from less than 0.5 mm (nutrients with slow diffusion) up to more than 50 mm (for gases). However, the most common effects were between 1 - 10 mm. Sharp gradients (e.g. for P, carboxylic acids, enzyme activities) allowed to calculate clear rhizosphere boundaries and so, the soil volume affected by roots. The first analyses were done to assess the effects of soil texture and moisture as well as root system and age on these gradients. The most properties can be described by two curve types: exponential saturation and S curve, each with increasing and decreasing concentration profiles from the root surface. The gradient based distribution functions were calculated and used to extrapolate on the whole soil depending on the root density and rooting intensity. We

  1. Selecting cryptographic key sizes

    OpenAIRE

    Verheul, E. R.; Lenstra, Arjen K.

    2001-01-01

    In this article we offer guidelines for the determination of key sizes for symmetric cryptosystems, RSA, and discrete logarithm-based cryptosystems both over finite fields and over groups of elliptic curves over prime fields. Our recommendations are based on a set of explicitly formulated parameter settings, combined with existing data points about the cryptosystems.

  2. Growth processes leading to a large or small adult size.

    Science.gov (United States)

    Gasser, T; Sheehy, A; Molinari, L; Largo, R H

    2001-01-01

    The way in which a large size in anthropometric variables is achieved is a longstanding problem, since the pubertal spurt shows statistically and clinically little association with adult size (mostly studied for height). By analysing longitudinal growth of groups of subjects with a large or a small adult size separately for height, leg and sitting height, and bihumeral and biiliac width, we studied this problem in some detail. Of interest are growth patterns specific for these variables and for boys or girls. The data consist of 120 boys and 112 girls followed longitudinally from 4 weeks until adulthood. Statistically, structural average velocity curves were computed for each variable and each subgroup separately for comparison. This velocity curve represents the average intensity and the average tempo of growth. Since the area under the velocity curve is adult size, differences in the growth process can be visualized. Both sexes show similar patterns in reaching a small or large adult size. The different variables, however, show marked differences. Only for legs is the pubertal spurt delayed for the large groups (with additional gains in prepubertal years). For sitting height and biiliac width, a slightly elevated velocity all along development (after 2 years) leads to a larger size and for bihumeral width the size of the pubertal peak is decisive. The steering of growth to a certain target size is qualitatively similar for boys and girls, but quite different for different anthropometric variables. This leads to questions about endocrinological control for various parts of the body and differential bone growth in development.

  3. Break-before-Make CMOS Inverter for Power-Efficient Delay Implementation

    Directory of Open Access Journals (Sweden)

    Janez Puhan

    2014-01-01

    Full Text Available 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.

  4. 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.

  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. 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

  7. 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.

  8. Delayed presentation or delayed diagnosis? A retrospective study of prospectively collected data of 482 foot and ankle injuries.

    Science.gov (United States)

    Shah, Rajiv; Shah, Shivam

    2017-08-01

    Delayed presentation of injury cases is common in developing countries like India. It is prudent to study reasons for delayed presentations to focus preventive measures towards responsible factors. Since foot and ankle orthopaedics is in its infancy in India, it was deemed to be worthwhile to study reasons for delayed presentations of foot and ankle injuries. Retrospective analysis of prospectively collected data from 482 foot and ankle injuries treated at our three foot and ankle centres over past three years was undertaken. Delayed presentation was defined as cases presenting to us at or after 3 weeks of injury, but with complete records. Reasons for delayed presentations were analysed. There were ninety eight such cases who fulfilled the delayed presentation criteria and within this group there were twenty different varieties of foot and ankle injuries. Of these twenty six cases were never treated by qualified orthopaedic surgeons and were labelled as direct delayed presentations, and the remaining 72 cases who were treated by qualified orthopaedic surgeons, but could not be diagnosed and presented late, were labelled as indirect delayed presentations. Failure to suspect injury (5 cases) or failure to diagnose injury (67 cases) were reasons for indirect delayed presentations. Failure to diagnose injury on part of clinicians was either due to failure of clinical and radiological analysis (analytical failure - 15 cases) or due to failure to investigate case with further radiological investigations (investigative failure - 10 cases). Forty-two cases had combined failures. In developing countries like India, patients did neglect their foot and ankle injuries and presented late. In fact, by way of delayed diagnosis, clinicians were more responsible for indirect delayed presentations of foot and ankle injuries. This is contrary to the common belief that in developing countries like India, only patients would be solely responsible for delayed presentations after injury

  9. 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

  10. Design-for-Delay Testability Techniques for High-Speed Digital Circuits

    NARCIS (Netherlands)

    Vermaak, H.J.

    2005-01-01

    The importance of delay faults is enhanced by the ever increasing clock rates and decreasing geometry sizes of nowadays’ circuits. This thesis focuses on the development of Design-for-Delay-Testability (DfDT) techniques for high-speed circuits and embedded cores. The rising costs of IC testing and

  11. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  12. Time delay in quantum scattering

    International Nuclear Information System (INIS)

    Tee, R.G.

    1978-01-01

    As is well known, the knowledge of the scattering cross section and its angular dependence, as a function of energy, is insufficient to determine the phase shifts uniquely. This led Eisenbud and Wigner to propose the measurement of the scattering lifetime or time delay as an additional independent datum. A rigorous time-dependent study of time delay within the framework of Hilbert space formalism is presented. Specifically, Martin's theory of time delay and the validity of the Eisenbud-Wigner time delay formula are extended to spherically symmetric potentials satisfying the asymptotic fall-off rate V(r) → O(r/sup -2-epsilon/). This extension is obtained by use of a maximal estimate of the rate of convergence of the asymptotic condition and the elimination of Martin's requirement that the scattering operator S be three times differentiable with respect to the free-particle Hamiltonian H 0 . Also presented are related results on the total time a quantum particle spends inside some bounded regions in position space. It is then proved that any two free particles having identical distributions of energy and angular momentum take exactly identical expectation values for the transit time across an arbitrary spherical region centered at the origin in position space. Ways to extend this result to nonfree Hamiltonians are indicated. Finally, the relationship between the position operator and the Eisenbud-Wigner time delay operator is examined. It is shown that the usual method of calculating time delay based on the classical analysis of the position operator is not exact

  13. 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)

  14. Stochastic modelling of train delays and delay propagation in stations

    NARCIS (Netherlands)

    Yuan, J.

    2006-01-01

    A trade-off exists between efficiently utilizing the capacity of railway networks and improving the reliability and punctuality of train operations. This dissertation presents a new analytical probability model based on blocking time theory which estimates the knock-on delays of trains caused by

  15. 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.

  16. Individual cochlear delays measured with tone-burst-evoked otoacoustic emissions

    DEFF Research Database (Denmark)

    Pigasse, Gilles; Harte, James; Dau, Torsten

    Methods to estimate cochlear delay in humans have been traditionally based on either phase-derived group delays from otoacoustic emissions (OAEs), or auditory brainstem responses (ABR). These methods demonstrate large variability in cochlear delay estimates, and are derived from across subject...... averages. This work aims to assess the individual variability in cochlear delay. Tone-burst evoked otoacoustic emissions (TBOAEs) are used in this study to estimate cochlear delay. The OAE is analysed by separating the non-linear components of cochlear origin, and the linear reflection in the time domain...

  17. 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. ...

  18. Delayed Neutrons and Photoneutrons from Fission Products

    International Nuclear Information System (INIS)

    Amiel, S.

    1965-01-01

    Delayed neutrons: Most studies of the delayed neutrons from fission have involved analysis of the kinetic behaviour of fusion chain- reacting systems, analysis of the gross neutron decay (resolved into six groups with approximate half-lives of 0.2, 0.5, 2, 6, 22 and 55 s) and some measurements of the neutron spectra (the energies extendfrom 0.1 to 1.2 MeV, peaking in the range 0.2 to 0.5 MeV). Rapid separations of fission-produced halogens have indicated seven isotopes (Br 87,88,89,90 and I 137,138,139 ). and rare gas analysis has indicated 1.5-s Kr and 6-s Rb as definite delayed neutron precursors. These identified precursors account for some 80% of the total delayed neutron yields. Theoretical predictions of possible precursors point to a few tens of such nuclides to be found mainly in regions just above closed neutron shells. Total neutron yields are observed to increase with mass number and decrease with atomic number of the fissioning nuclide. Yields are nearly independent of the energy of the incident fissioning neutron at energies up to several MeV. In this range observed group yields,-especially of the long-lived precursors, ate in fairly good agreement with fission mass and charge distributions, and calculated neutron emission probabilities. . Further detailed studies of delayed neutron precursors (particularly in the difficult short half-life region) require development of ultra-fast radiochemical separation procedures (or on-line isotope separation) and fast neutron spectroscopy of high resolution and efficiency. Photoneutrons; A knowledge of the intensities and gamma-ray spectra of fission products is of practical importance in reactor technology particularly with respect to gamma heating, shielding and radiation effects. Gamma-rays of energies greater than 2.23 and 1.67 MeV cause emission of photoneutrons from deuterium and beryllium respectively, and are important in the kinetics of heavy water and beryllium-moderated reactors. The rate of

  19. Delays and user performance in human-computer-network interaction tasks.

    Science.gov (United States)

    Caldwell, Barrett S; Wang, Enlie

    2009-12-01

    This article describes a series of studies conducted to examine factors affecting user perceptions, responses, and tolerance for network-based computer delays affecting distributed human-computer-network interaction (HCNI) tasks. HCNI tasks, even with increasing computing and network bandwidth capabilities, are still affected by human perceptions of delay and appropriate waiting times for information flow latencies. Conducted were 6 laboratory studies with university participants in China (Preliminary Experiments 1 through 3) and the United States (Experiments 4 through 6) to examine users' perceptions of elapsed time, effect of perceived network task performance partners on delay tolerance, and expectations of appropriate delays based on task, situation, and network conditions. Results across the six experiments indicate that users' delay tolerance and estimated delay were affected by multiple task and expectation factors, including task complexity and importance, situation urgency and time availability, file size, and network bandwidth capacity. Results also suggest a range of user strategies for incorporating delay tolerance in task planning and performance. HCNI user experience is influenced by combinations of task requirements, constraints, and understandings of system performance; tolerance is a nonlinear function of time constraint ratios or decay. Appropriate user interface tools providing delay feedback information can help modify user expectations and delay tolerance. These tools are especially valuable when delay conditions exceed a few seconds or when task constraints and system demands are high. Interface designs for HCNI tasks should consider assistant-style presentations of delay feedback, information freshness, and network characteristics. Assistants should also gather awareness of user time constraints.

  20. 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

  1. Delayed neurological deterioration due to progressive pneumocephalus

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2015-03-01

    Full Text Available Pneumocephalus can develop immediately following head trauma or clinical presentation may be delayed for days. We report a case of 35 year male whose initial CT scan brain plain small specks of pneumocephalus in left para-sellar region. However the next day he was complaining of severe headache and had multiple episodes of vomiting. Repeat CT scan showed increase in the size of pneumocephalus including appearance of intraventricular air with mild cerebral edema. The patient recovered well with conservative management. The present case is a gentle reminder that in a subgroup of head injury patients, intracranial air can produce significant mass effect leading to tension pneumocephalus which can can behave like other intracranial mass lesions and causes worsening of the neurological status of these patients.

  2. EAMJ Delayed April 10.indd

    African Journals Online (AJOL)

    2010-04-04

    Apr 4, 2010 ... and Director, Kenyatta National Hospital, P.O. Box 19961-00202, Nairobi, Kenya, S.K. Kimende, MBChB, MMed (Surg.) Lecturer, Department of Surgery, ... For purposes of management, breast cancer is clinically divided into early .... delays inherent in out healthcare systems (18,19). Indeed, one of the most ...

  3. Early-delayed radiation rhombencephalopathy

    International Nuclear Information System (INIS)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F.; Newcastle upon Tyne Univ.

    1982-01-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

  4. Advanced optical delay line demonstrator

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in cooperation with Micromega-Dynamics and Dutch Space, has designed an advanced Optical Delay Line (ODL) for use in future ground based and space interferometry missions. The work is performed under NIVR contract in preparation for GENIE and DARWIN. Using the ESO PRIMA DDL requirements as

  5. Diagnostic Delay in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    to approach their general practitioner (GP) with joint pain, and also how GPs respond to patients' complaints. METHODS: The study was based on qualitative data collected using 11 semi-structured individual interviews. RESULTS: When symptoms were obvious to patients, there was a shorter delay between symptom...

  6. Livermore blasted for project delay

    CERN Multimedia

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  7. Weather delay costs to trucking.

    Science.gov (United States)

    2012-11-01

    Estimates of the nations freight sector of transportation range to upwards of $600 billion of total gross domestic product with 70 percent of total value and 60 percent of total weight moving by truck. Weather-related delays can add significantly ...

  8. Another definition for time delay

    International Nuclear Information System (INIS)

    Narnhofer, H.

    1980-01-01

    Time delay is defined by geometrical considerations which work in classical as well as in quantum mechanics, and its connection with the S-matrix and the virial is proven for potentials with V(x vector) and x vector V(x vector) vanishing as rsup(-1-epsilon) for r -> infinity. (Author)

  9. Early-delayed radiation rhombencephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F. (Royal Victoria Infirmary, Newcastle upon Tyne (UK); Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1982-03-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome.

  10. Delayed School Entry in Uganda

    Science.gov (United States)

    Moyi, Peter

    2011-01-01

    Since 1997 Uganda has seen a large increase in school enrolment. Despite this increased enrolment, universal education has remained elusive. Many children enrol in school, but not at the recommended age, and they drop out before completing school. This article focuses on one of these problems--delayed school entry. What household factors are…

  11. Providing delay guarantees in Bluetooth

    NARCIS (Netherlands)

    Ait Yaiz, R.; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network.

  12. Millisecond laser machining of transparent materials assisted by a nanosecond laser with different delays.

    Science.gov (United States)

    Pan, Yunxiang; Lv, Xueming; Zhang, Hongchao; Chen, Jun; Han, Bing; Shen, Zhonghua; Lu, Jian; Ni, Xiaowu

    2016-06-15

    A millisecond laser combined with a nanosecond laser was applied to machining transparent materials. The influences of delay between the two laser pulses on processing efficiencies and modified sizes were studied. In addition, a laser-supported combustion wave (LSCW) was captured during laser irradiation. An optimal delay corresponding to the highest processing efficiency was found for cone-shaped cavities. The modified size as well as the lifetime and intensity of the LSCW increased with the delay decreasing. Thermal cooperation effects of defects, overlapping effects of small modified sites, and thermal radiation from LSCW result in all the phenomena.

  13. Timing of implant placement after tooth extraction: immediate, immediate-delayed or delayed implants? A Cochrane systematic review.

    Science.gov (United States)

    Esposito, Marco; Grusovin, Maria Gabriella; Polyzos, Ilias P; Felice, Pietro; Worthington, Helen V

    2010-01-01

    This review is based on a Cochrane systematic review entitled ‘Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants)' published in The Cochrane Library (see http://www.cochrane.org/ for information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane review can be interpreted differently, depending on people's perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration. To evaluate success, complications, aesthetics and patient satisfaction among immediate, immediate-delayed and delayed implants in post-extractive sockets and whether and when augmentation procedures are necessary and which is the most effective augmentation technique. The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to the 2nd of June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 1 year in function comparing immediate, immediate-delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants. Outcome measures were prosthesis and implant failures, complications, patient satisfaction and preference including aesthetics, aesthetics evaluated by a dentist, peri-implant marginal bone level changes, etc. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was

  14. Analysis of a first-order delay differential-delay equation containing two delays

    Science.gov (United States)

    Marriott, C.; Vallée, R.; Delisle, C.

    1989-09-01

    An experimental and numerical analysis of the behavior of a two-delay differential equation is presented. It is shown that much of the system's behavior can be related to the stability behavior of the underlying linearized modes. A new phenomenon, mode crossing, is explored.

  15. 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

  16. 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.

  17. Procrastination by pigeons: preference for larger, more delayed work requirements.

    Science.gov (United States)

    Mazur, J E

    1996-01-01

    In three experiments, pigeons chose between alternatives that required the completion of a small ratio schedule early in the trial or a larger ratio schedule later in the trial. Completion of the ratio requirement did not lead to an immediate reinforcer, but simply allowed the events of the trial to continue. In Experiment 1, the ratio requirements interrupted periods in which food was delivered on a variable-time schedule. In Experiments 2 and 3, each ratio requirement was preceded and followed by a delay, and only one reinforcer was delivered, at the end of each trial. Two of the experiments used an adjusting-ratio procedure in which the ratio requirement was increased and decreased over trials so as to estimate an indifference point--a ratio size at which the two alternatives were chosen about equally often. These experiments found clear evidence for "procrastination"--the choice of a larger but more delayed response requirement. In some cases, subjects chose the more delayed ratio schedule even when it was larger than the more immediate alternative by a factor of four or more. The results suggest that as the delay to the start of a ratio requirement is increased, it has progressively less effect on choice behavior, in much the same way that delaying a positive reinforcer reduces it effect on choice. PMID:8583195

  18. Procrastination by pigeons: preference for larger, more delayed work requirements.

    Science.gov (United States)

    Mazur, J E

    1996-01-01

    In three experiments, pigeons chose between alternatives that required the completion of a small ratio schedule early in the trial or a larger ratio schedule later in the trial. Completion of the ratio requirement did not lead to an immediate reinforcer, but simply allowed the events of the trial to continue. In Experiment 1, the ratio requirements interrupted periods in which food was delivered on a variable-time schedule. In Experiments 2 and 3, each ratio requirement was preceded and followed by a delay, and only one reinforcer was delivered, at the end of each trial. Two of the experiments used an adjusting-ratio procedure in which the ratio requirement was increased and decreased over trials so as to estimate an indifference point--a ratio size at which the two alternatives were chosen about equally often. These experiments found clear evidence for "procrastination"--the choice of a larger but more delayed response requirement. In some cases, subjects chose the more delayed ratio schedule even when it was larger than the more immediate alternative by a factor of four or more. The results suggest that as the delay to the start of a ratio requirement is increased, it has progressively less effect on choice behavior, in much the same way that delaying a positive reinforcer reduces it effect on choice.

  19. 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.

  20. 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.

  1. Interest of delayed images in the detection of small size lesions in positron emission tomography (PET): about a case of peritoneal carcinosis evaluation; Interet des images tardives dans la detection de lesion de petite taille en tomographie par emission de positons (TEP): a propos d'un cas de bilan de carcinose peritoneale

    Energy Technology Data Exchange (ETDEWEB)

    Rakotonirina, H.; Berthelot, C.; Vervueren, L.; Agius, C.; Jeanguillaume, C.; Couturier, O. [Service de medecine nucleaire, CHU d' Angers, (France)

    2009-05-15

    Because of the effect of partial volume, the small injuries (under 1 cm) are not the most often seen in F.D.G.-PET. however, if the gradient tumor/background noise is important, it is sometimes possible to visualize them. To increase this gradient, we can increase the tumor captation of F.D.G. by increasing the time of captation, or reduce the vascular background noise by making easy the urinary excretion. through a clinical case, we remind the interest of delayed images ( 2 hours after injection) associated to the injection of furosemide in the detection of small injuries of peritoneal carcinosis. (N.C.)

  2. Air congestion delay: a review

    Directory of Open Access Journals (Sweden)

    Daniel Alberto Pamplona

    2016-04-01

    Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

  3. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  4. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  5. 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.

  6. Reconfigurable Reduced Delay Universal Adder

    OpenAIRE

    Mohit Tyagi,; Samender Singh,; Kavita Khare

    2011-01-01

    This paper introduces a novel architecture for least latency universal adder using pipeline and parallel computing technique. The proposed architecture implemented in reconfigurable technology as arun time reconfigurable unit. The proposed 32-bit Universal adder design and compared with previously proposed adder designs in terms of area and delay after synthesis targeting on 4vfx60ff672-12 Xilinxvirtex-4 FPGA and have high hardware resource sharing up to 42% for the binary and BCD arithmetic ...

  7. [Determinants of induced abortion delay].

    Science.gov (United States)

    Font-Ribera, Laia; Pérez, Glòria; Espelt, Albert; Salvador, Joaquin; Borrell, Carme

    2009-01-01

    In induced abortion, the method, the risk of complications and the economic cost of the abortion are determined by gestational age. The aim of this study was to describe the determinants of induced abortion delay until the second trimester of pregnancy in Barcelona. We performed a cross-sectional study of induced abortions due to the physical or mental health of the woman (Barcelona, 2004-2005; N=9,175). The city's induced abortion register provided data on gestational age at abortion (dependent variable), educational level, age, cohabitation with the partner, number of children previous abortions, and type of center. Adjusted prevalence ratios (aPR) were calculated with log-binomial regression models. A total of 7.7% of induced abortions were second-trimester abortions and 99.3% were performed in private centers. Compared with women with a university education, those with primary education or less had an aPR of 1.8 (95% confidence interval [95%CI]: 1.4-2.2) of delaying the abortion until the second trimester. A higher proportion of second-trimester abortions were also recorded in women aged less than 18 years old (aPR=2.6; 95%CI: 2.0-3.4), women not cohabiting with their partners (aRP=1.4; 95% CI: 1.2-1.6) and in public centers (aPR=2.8; 95% CI: 2.2-3.7). No differences were found in induced abortion delay among women with previous abortions and those without. Induced abortion delay until the second trimester of pregnancy was associated with low educational level, young ages, not cohabiting with a partner, and public centers. This study demonstrates the existence of socioeconomic inequalities in access conditions to abortion services.

  8. Assembly delay line pulse generators

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  9. Teriparatide Induced Delayed Persistent Hypercalcemia

    OpenAIRE

    Thiruchelvam, Nirosshan; Randhawa, Jaskirat; Sadiek, Happy; Kistangari, Gaurav

    2014-01-01

    Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  10. Teriparatide Induced Delayed Persistent Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  11. ATLAS calibration delay chip study

    CERN Document Server

    Massol, N

    2003-01-01

    The delay chip is an ASIC developed to precisely adjust signals within the range of 0-24ns in steps of 1ns. In this note, we report the study of the characteristics of this chip like the linearity and the jitter. We describe the influence of temperature and supply voltage on its behavior. Finally, we study its dependency due to the variations in process on a whole production.

  12. Extreme fluctuations in stochastic network coordination with time delays

    Science.gov (United States)

    Hunt, D.; Molnár, F.; Szymanski, B. K.; Korniss, G.

    2015-12-01

    We study the effects of uniform time delays on the extreme fluctuations in stochastic synchronization and coordination problems with linear couplings in complex networks. We obtain the average size of the fluctuations at the nodes from the behavior of the underlying modes of the network. We then obtain the scaling behavior of the extreme fluctuations with system size, as well as the distribution of the extremes on complex networks, and compare them to those on regular one-dimensional lattices. For large complex networks, when the delay is not too close to the critical one, fluctuations at the nodes effectively decouple, and the limit distributions converge to the Fisher-Tippett-Gumbel density. In contrast, fluctuations in low-dimensional spatial graphs are strongly correlated, and the limit distribution of the extremes is the Airy density. Finally, we also explore the effects of nonlinear couplings on the stability and on the extremes of the synchronization landscapes.

  13. 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

  14. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  15. Internal mammary recipient site breast cancer recurrence following delayed microvascular breast reconstruction.

    Science.gov (United States)

    Rosich-Medina, Anais; Wang, Susan; Erel, Ertan; Malata, Charles M

    2013-01-01

    The internal mammary vessels are a popular recipient site for microsurgical anastomoses of free flap breast reconstructions. We, however, observed 3 patients undergoing internal mammary vessel delayed free flap breast reconstruction that subsequently developed tumor recurrence at this site. We reviewed their characteristics to determine whether there was a correlation between delayed microsurgical reconstruction and local recurrence. A retrospective review of a single surgeon's delayed free flap breast reconstructions using the internal mammary vessels was conducted over a 7-year period to identify the time intervals between mastectomy and delayed breast reconstruction and between delayed breast reconstruction and recurrence. Three patients developed local recurrence at the site of the microvascular anastomoses following delayed breast reconstruction. All patients had been disease-free following mastectomy. The median time interval between mastectomy and delayed breast reconstruction was 28 months (range = 20-120 months) while that between delayed breast reconstruction and local recurrence was 7 months (range = 4-10 months). Two patients died from metastatic disease, 36 and 72 months following their local recurrence. One patient remains alive 44 months after reconstruction. Local tumor recurrence at the internal mammary vessel dissection site following delayed breast reconstruction raises the question whether these 2 events may be related. Specifically, could internal mammary vessel dissection undertaken for delayed microsurgical reconstruction predispose to recurrence in the internal mammary lymph nodes? Further research is needed to ascertain whether delayed breast reconstruction increases the risk of local recurrence in this patient group.

  16. Fine mapping of a QTL for ear size on porcine chromosome 5 and identification of high mobility group AT-hook 2 (HMGA2 as a positional candidate gene

    Directory of Open Access Journals (Sweden)

    Li Pinghua

    2012-03-01

    Full Text Available Abstract Background Ear size and shape are distinct conformation characteristics of pig breeds. Previously, we identified a significant quantitative trait locus (QTL influencing ear surface on pig chromosome 5 in a White Duroc × Erhualian F2 resource population. This QTL explained more than 17% of the phenotypic variance. Methods Four new markers on pig chromosome 5 were genotyped across this F2 population. RT-PCR was performed to obtain expression profiles of different candidate genes in ear tissue. Standard association test, marker-assisted association test and F-drop test were applied to determine the effects of single nucleotide polymorphisms (SNP on ear size. Three synthetic commercial lines were also used for the association test. Results We refined the QTL to an 8.7-cM interval and identified three positional candidate genes i.e. HMGA2, SOX5 and PTHLH that are expressed in ear tissue. Seven SNP within these three candidate genes were selected and genotyped in the F2 population. Of the seven SNP, HMGA2 SNP (JF748727: g.2836 A > G showed the strongest association with ear size in the standard association test and marker-assisted association test. With the F-drop test, F value decreased by more than 97% only when the genotypes of HMGA2 g.2836 A > G were included as a fixed effect. Furthermore, the significant association between g.2836 A > G and ear size was also demonstrated in the synthetic commercial Sutai pig line. The haplotype-based association test showed that the phenotypic variance explained by HMGA2 was similar to that explained by the QTL and at a much higher level than by SOX5. More interestingly, HMGA2 is also located within the dog orthologous chromosome region, which has been shown to be associated with ear type and size. Conclusions HMGA2 was the closest gene with a potential functional effect to the QTL or marker for ear size on chromosome 5. This study will contribute to identify the causative gene and mutation underlying

  17. PDGF ENZYMATIC ACTIVITY IN PATIENTS WITH DELAYED FRACTURE CONSOLIDATION

    Directory of Open Access Journals (Sweden)

    D. V. Kuzmenko

    2017-01-01

    Full Text Available Introduction. Techniques that use growth factors to improve bone fragment consolidation and to treat the inflammatory and degenerative diseases of the musculoskeletal system have become very popular. Many researchers are actively searching for personification of this therapy and the reasons for delayed consolidation. The purpose of the study – to identify the biomarker for delayed bone consolidation.Materials and Methods. The study groups consisted of patients with high-energy tibia open fractures with normal (group 1 and with delayed (2nd group consolidation of bone fragments. The enzymatic activity of platelet-derived growth factor (PDGF in blood serum was studied after 7 days and in 1, 3 and 6 months after bone fragments reduction. Spectrophotometric technique (Specord-200 was used.Results. In patients with normal consolidation of bone fragments, the enzymatic activity of PDGF was statistically significantly higher in comparison with the group with delayed healing. At the same time, the highest activity was reported on day 7, and by third month it was becoming lower.Conclusion. Bone healing depends on PDGF enzymatic activity, besides significant differences on various stages of healing were observed. Further study the reasons for the PDGF enzymatic deficiency and its correction are of a great interest for reducing the timing of consolidation.

  18. Synchronization in networks with heterogeneous coupling delays

    Science.gov (United States)

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  19. 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

  20. Variation in the species composition and mean body size of an avian foliage-gleaning guild along an elevational gradient: correlation with arthropod body size.

    Science.gov (United States)

    Janes, Stewart W

    1994-08-01

    The composition of an avian foliage-gleaning guild was analyzed with respect to body size at nine sites along an elevational gradient in the Oregon Cascades. Mean body size decreased from 20.5 g near the lower forest boundary where it meets the grassland at about 775 m to 9.3 g near timberline at about 1720 m. Both the loss of larger species and the gain of smaller species contributed to the change. Mean volume of the foliage-dwelling arthropods also decreased with increasing elevation by two orders of magnitude along the same gradient. A significant decrease in body size occurred in three arthropod groups, larval Lepidoptera, Homoptera, and spiders, and of these, larval Lepidoptera dominated the overall size trend among arthropods. Both developmental differences (higher elevation sites are delayed seasonally on the same calendar date) and taxonomic differences contributed to the change in mean arthropod size. Mean bird size was positively correlated (r=0.93) with the body size of foliage-dwelling arthropods. A similar pattern was suggested for other avian guilds dependent directly or indirectly upon foliage-dwelling arthropods, but not for guilds independent of foliage-dwelling arthropods.

  1. Au70S20(PPh3)12: an intermediate sized metalloid gold cluster stabilized by the Au4S4 ring motif and Au-PPh3 groups.

    Science.gov (United States)

    Kenzler, Sebastian; Schrenk, Claudio; Frojd, Andrew R; Häkkinen, Hannu; Clayborne, Andre Z; Schnepf, Andreas

    2018-01-02

    Reducing (Ph 3 P)AuSC(SiMe 3 ) 3 with l-Selectride® gives the medium-sized metalloid gold cluster Au 70 S 20 (PPh 3 ) 12 . Computational studies show that the phosphine bound Au-atoms not only stabilize the electronic structure of Au 70 S 20 (PPh 3 ) 12 , but also behave as electron acceptors leading to auride-like gold atoms on the exterior.

  2. Delayed diagnosis of sarcoidosis is common in Brazil

    Directory of Open Access Journals (Sweden)

    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.

  3. Dynamic Cournot Duopoly Game with Delay

    Directory of Open Access Journals (Sweden)

    A. A. Elsadany

    2014-01-01

    Full Text Available The delay Cournot duopoly game is studied. Dynamical behaviors of the game are studied. Equilibrium points and their stability are studied. The results show that the delayed system has the same Nash equilibrium point and the delay can increase the local stability region.

  4. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  5. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Philipp J. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Faculty of Medicine, University of Heidelberg, Heidelberg (Germany); Park, Henry S. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Knisely, Jonathan P.S. [Department of Radiation Medicine, North Shore University Hospital, Manhasset, New York (United States); Chiang, Veronica L. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Vortmeyer, Alexander O., E-mail: alexander.vortmeyer@yale.edu [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States)

    2012-05-01

    Purpose: Recently, single-fraction, high-dosed focused radiation therapy such as that administered by Gamma Knife radiosurgery has been used increasingly for the treatment of metastatic brain cancer. Radiation therapy to the brain can cause delayed leukoencephalopathy, which carries its own significant morbidity and mortality. While radiosurgery-induced leukoencephalopathy is known to be clinically different from that following fractionated radiation, pathological differences are not well characterized. In this study, we aimed to integrate novel radiographic and histopathologic observations to gain a conceptual understanding of radiosurgery-induced leukoencephalopathy. Methods and Materials: We examined resected tissues of 10 patients treated at Yale New Haven Hospital between January 1, 2009, and June 30, 2010, for brain metastases that had been previously treated with Gamma Knife radiosurgery, who subsequently required surgical management of a symptomatic regrowing lesion. None of the patients showed pathological evidence of tumor recurrence. Clinical and magnetic resonance imaging data for each of the 10 patients were then studied retrospectively. Results: We provide evidence to show that radiosurgery-induced leukoencephalopathy may present as an advancing process that extends beyond the original high-dose radiation field. Neuropathologic examination of the resected tissue revealed traditionally known leukoencephalopathic changes including demyelination, coagulation necrosis, and vascular sclerosis. Unexpectedly, small and medium-sized vessels revealed transmural T-cell infiltration indicative of active vasculitis. Conclusions: We propose that the presence of a vasculitic component in association with radiation-induced leukoencephalopathy may facilitate the progressive nature of the condition. It may also explain the resemblance of delayed leukoencephalopathy with recurring tumor on virtually all imaging modalities used for posttreatment follow-up.

  6. Reactor shutdown delays medical procedures

    Science.gov (United States)

    Gwynne, Peter

    2008-01-01

    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  7. Saccades and fixations in children with delayed reading skills.

    Science.gov (United States)

    Vinuela-Navarro, Valldeflors; Erichsen, Jonathan T; Williams, Cathy; Woodhouse, J Margaret

    2017-07-01

    Previous studies have reported that eye movements differ between good/average and poor readers. However, these studies have been limited to investigating eye movements during reading related tasks, and thus, the differences found could arise from deficits in higher cognitive processes involved in reading rather than oculomotor performance. The purpose of the study is to determine the extent to which eye movements in children with delayed reading skills are different to those obtained from children with good/average reading skills in non-reading related tasks. After a screening optometric assessment, eye movement recordings were obtained from 120 children without delayed reading skills and 43 children with delayed reading skills (4 to 11 years) using a Tobii TX300 eye tracker. Cartoon characters were presented horizontally from -20° to +20° in steps of 5° to study saccades. An animated stimulus in the centre of the screen was presented for 8 seconds to study fixation stability. Saccadic main sequences, and the number and amplitude of the saccades during fixation were obtained for each participant. Children with delayed reading skills (n = 43) were unmasked after data collection was completed. Medians and quartiles were calculated for each eye movement parameter for children without (n = 120) and with (n = 43) delayed reading skills. Independent t-tests with Bonferroni correction showed no significant differences in any of the saccadic main sequence parameters (Slope, Intercept, A, n and Q ratio) between children without and with delayed reading (p > 0.01). Similarly, no significant differences were found in the number of saccades and their amplitude during the fixation task between the two groups (p > 0.05). Further, none of the gross optometric parameters assessed (visual acuity, refractive error, ocular alignment, convergence, stereopsis and accommodation accuracy) were found to be associated with delayed reading skills (p > 0.05). Eye movements in

  8. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  9. Commission errors in delay-execute prospective memory tasks.

    Science.gov (United States)

    Schaper, Philipp; Grundgeiger, Tobias

    2017-08-01

    Individuals frequently retrieve an intention, but the execution of the task needs to be delayed due to ongoing task demands - so-called delay-execute prospective memory (PM) tasks. We investigated commission errors in the delay-execute paradigm. Participants were told that a PM task is finished (PM task has been executed and is now finished for a final phase) or cancelled (PM task has been cancelled immediately after introduction). We observed commission errors and ongoing task performance in the final phase which included several irrelevant PM cues. In two experiments, we observed significantly more commission errors for cancelled compared to the finished intentions. In Experiment 2, commission errors were eliminated if the final phase required divided attention, regardless of PM task status. In addition, we observed significantly more PM cue interference on the ongoing task in the cancelled compared to the finished group, indicating that the PM task was retrieved in the cancelled group but not in the finished group. As retrieval and execution of the PM task were separated by a delay, the results indicate that commission errors are not always the result of a quick, spontaneous retrieval-execution sequence and may also occur when retrieval and execution are temporally separated.

  10. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  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 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.

  12. 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...

  13. 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

  14. Effects of alveolar ridge preservation on delayed implant osseointegration.

    Science.gov (United States)

    Shao, Shan; Li, Bin; Xue, Hui-Min; Huang, Hai-Yun; Liu, Gang-Li

    2015-01-01

    To evaluate the effects of alveolar ridge preservation with Bio-Oss bone substitute (Geistlich Pharma) on delayed implant osseointegration. The 3rd and 4th left and right mandibular premolars were extracted from four adult healthy male and female dogs. For the experimental group, we randomly selected two extraction sockets in each dog to be filled with Bio-Oss bone substitute (Geistlich Pharma). The two remaining extraction sockets remained untreated and served as the control group. Three months after Bio-Oss placement, dental implants were inserted into the alveolar bone of the experimental group and the control group. The osteogenic activity of the bone around the implants was assessed by evaluating the histological morphology and by estimating histomorphometric parameters at 3 and 6 months after delayed implantation. At 3 months, Goldner's trichrome staining analysis showed that the bone-implant contact rate and mineralised bone area around the implant were significantly higher in the experimental group (75.98% ± 8.97% and 69.52% ± 9.63%, respectively) than in the control group (56.13% ± 8.18% and 52.82% ± 7.25%, respectively; P alveolar ridge preservation by using Bio-Oss placement can promote osseointegration of delayed implantation. This may be a promising option for clinical use.

  15. Multiuser Delay-Tracking CDMA Receiver

    Directory of Open Access Journals (Sweden)

    Zha Wei

    2002-01-01

    Full Text Available We propose to integrate delay tracking into a successive interference cancellation (SIC code division multiple access (CDMA multiuser detector. Delay-robust SIC was initially proposed for CDMA multiuser detection when there exist time delay estimation errors. When the delay error is small, the true user signature vector can be approximately expanded around the estimated time delay as a linear combination of an estimated signature vector and an error vector. The amplitude of the error signal can be recursively estimated and cancelled in the multistage SIC iterations by using the tentative feedback decisions. Since the relative amplitude of the error signal provides information about the delay error, we propose the application of error signal feedback to improve the delay estimation. In a sliding window implementation, the delay-robust SIC is used to track multiple time varying user delays. For constant or slowly varying channels, a soft-decision function can be used to improve the delay-robust SIC. For fast fading channels, a linear decision function is used. Delay-tracking results for both rectangular chip pulses and band-limited chip pulses are shown.

  16. PRECISION TIME-DELAY GENERATOR

    Science.gov (United States)

    Carr, B.J.; Peckham, V.D.

    1959-06-16

    A precision time-delay generator circuit with low jitter is described. The first thyratron has a series resonant circuit and a diode which is connected to the second thyratron. The first thyratron is triggered at the begin-ning of a time delay and a capacitor is discharged through the first thyratron and the diode, thereby, triggering the second thyratron. (T.R.H.) l6l9O The instrument described can measure pressures between sea level and 300,000 ft. The pressure- sensing transducer of the instrument is a small cylindrical tube with a thin foil of titanium-tritium fastened around the inside of the tube. Output is a digital signal which can be used for storage or telemetering more conveniently than an analog signal. (W.D.M.) l6l9l An experimental study was made on rolling contacts in the temperature range of 550 to 1000 deg F. Variables such as material composition, hardness, and operating conditions were investigated in a rolling test stand. Ball bearing tests were run to determine the effect of design parameters, bearing materials, lubricants, and operating conditions. (auth)

  17. Cross delay line sensor characterization

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Israel J [Los Alamos National Laboratory; Remelius, Dennis K [Los Alamos National Laboratory; Tiee, Joe J [Los Alamos National Laboratory; Buck, Steven E [Los Alamos National Laboratory; Whittemore, Stephen R [Los Alamos National Laboratory; Thompson, David C [Los Alamos National Laboratory; Shirey, Robert [Los Alamos National Laboratory

    2010-01-01

    There exists a wealth of information in the scientific literature on the physical properties and device characterization procedures for complementary metal oxide semiconductor (CMOS), charge coupled device (CCD) and avalanche photodiode (APD) format detectors. Numerous papers and books have also treated photocathode operation in the context of photomultiplier tube (PMT) operation for either non imaging applications or limited night vision capability. However, much less information has been reported in the literature about the characterization procedures and properties of photocathode detectors with novel cross delay line (XDL) anode structures. These allow one to detect single photons and create images by recording space and time coordinate (X, Y & T) information. In this paper, we report on the physical characteristics and performance of a cross delay line anode sensor with an enhanced near infrared wavelength response photocathode and high dynamic range micro channel plate (MCP) gain (> 10{sup 6}) multiplier stage. Measurement procedures and results including the device dark event rate (DER), pulse height distribution, quantum and electronic device efficiency (QE & DQE) and spatial resolution per effective pixel region in a 25 mm sensor array are presented. The overall knowledge and information obtained from XDL sensor characterization allow us to optimize device performance and assess capability. These device performance properties and capabilities make XDL detectors ideal for remote sensing field applications that require single photon detection, imaging, sub nano-second timing response, high spatial resolution (10's of microns) and large effective image format.

  18. Delayed coker fractionator advanced control

    Energy Technology Data Exchange (ETDEWEB)

    Jaisinghani, R.; Minter, B. (ABB SIMCON Inc., Houston, TX (United States)); Tica, A.; Puglesi, A.; Ojeda, R. (Yacimentos Petroliferos Fiscales, Mendoza (Argentina))

    1993-08-01

    In a delayed coking process, as coke drum switches are made, rapid changes occur in both the fractionator feed rate and composition. With conventional control, it is not unusual to see long transient behavior of large swings in both quality and flowrates of coker gas oils. This can extract a heavy economic toll, not only in coker operation, but in the operation of downstream units as the upset is propagated. An advanced process control application (APC) was recently implemented on the coker fractionator at the Yacimentos Petroliferos Fiscales (YPF), Lujan de Cuyo Refinery, in Mendoza, Argentina. This coker fractionator control design was unique as it handled two different operating objectives: control of product qualities via tower temperature profile during normal operation and control of gas oil product flow ratio during drum switch. This combination of control objectives in one multivariable predictive control program was achieved by including special logic to decouple the individual tuning requirements. Also, additional logic was included to unambiguously detect and identify drum switch and drum steam out as discrete events within 30 seconds of their actual occurrence. These discrete events were then used as disturbance variables to minimize fractionator transient behavior. As a performance measure, the overhead temperature was controlled within 2 C to 2.5 C of its target, gas oil flows were stabilized during drum switches and steam generation via pump around was maximized. Overall, implementing advanced control for the delayed coker fractionator resulted in substantial benefits from product quality control, product flow control and minimized energy consumption.

  19. Reasons for diagnostic delay in gynecological malignancies

    DEFF Research Database (Denmark)

    Vandborg, Mai Partridge; Christensen, René dePont Christensen; Kragstrup, Jakob

    2011-01-01

    Aim The primary aim of this study was to identify and describe different delay types in women with gynecologic cancer, and to analyze the relationship between diagnostic delay and a number of characteristics for patients, cancers and the health care system. Setting A cohort study of women newly......) and The Danish Gynecological Cancer Database (DGCD). 161 women were included; ovarian cancer: 63, endometrial cancer: 50, cervical cancer: 34 and vulvar cancer: 14. Outcome measures were different delay types counted in days and the influence of four clinical important variables: Presence of alarm symptoms, age...... (≤ or > 60 years), performance of gynecological examination by the GP and notification of cancer suspicion on first referral from GP’s on the diagnostic delay (short delay ≤90 days and long delay >90 days). Results Across cancer type a median total delay of 101 days was observed. The 10% of women...

  20. Large Deviations for Gaussian Diffusions with Delay

    Science.gov (United States)

    Azencott, Robert; Geiger, Brett; Ott, William

    2018-01-01

    Dynamical systems driven by nonlinear delay SDEs with small noise can exhibit important rare events on long timescales. When there is no delay, classical large deviations theory quantifies rare events such as escapes from metastable fixed points. Near such fixed points, one can approximate nonlinear delay SDEs by linear delay SDEs. Here, we develop a fully explicit large deviations framework for (necessarily Gaussian) processes X_t driven by linear delay SDEs with small diffusion coefficients. Our approach enables fast numerical computation of the action functional controlling rare events for X_t and of the most likely paths transiting from X_0 = p to X_T=q. Via linear noise local approximations, we can then compute most likely routes of escape from metastable states for nonlinear delay SDEs. We apply our methodology to the detailed dynamics of a genetic regulatory circuit, namely the co-repressive toggle switch, which may be described by a nonlinear chemical Langevin SDE with delay.

  1. 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.

  2. Stress management and mind-body medicine: a randomized controlled longitudinal evaluation of students' health and effects of a behavioral group intervention at a middle-size German university (SM-MESH).

    Science.gov (United States)

    Esch, Tobias; Sonntag, Ulrike; Esch, Sonja Maren; Thees, Stefanie

    2013-01-01

    Student life can be stressful. Hence, we started a regular mind-body medical stress management program in 2006. By today, more than 500 students took part and evaluations showed significant results, especially with regard to a reduction of stress warning signals. For further analysis, we now decided to run a randomized controlled longitudinal trial. Participating students at Coburg University were randomized into an intervention (n = 24) or a waitlist control group (n = 19). The intervention group completed 3 sets (pre/post/follow-up) and the control group 2 sets (pre/post) of self-administered questionnaires. The questionnaires included: SF-12 Health Survey, Perceived Stress Scale (PSS), Sense of Coherence (SOC-L9), Visual Analogue Scale (VAS) concerning stress, and the Stress Warning Signs (SWS) scale. Randomly selected participants of the intervention group were also queried in qualitative interviews. The intervention consisted of an 8 week stress management group program (mind-body medical stress reduction - MBMSR). Follow-up measures were taken after 6 months. Virtually, no drop-out occurred. Our study showed significant effects in the intervention group concerning SF-12 Mental Component Scale (p = 0.05), SF-12 Physical Component Scale (p = 0.001), VAS (in general, p = 0.001) and SWS (emotional reactions, p students could be demonstrated. Findings suggest that stress management might be given importance at universities that care for the performance, the quality of life, and stress-health status of their students, acknowledging and accounting for the challenging circumstances of university life, as well as the specific needs of the modern student population. Copyright © 2013 S. Karger AG, Basel.

  3. Intron size and genome size in plants.

    Science.gov (United States)

    J. Wendel; R. Cronn; I. Alvarez; B. Liu; R. Small; D. Senchina

    2002-01-01

    It has long been known that genomes vary over a remarkable range of sizes in both plants (Bennett, Cox, and Leitch 1997) and animals (Gregory 2001). It also has become evident that across the broad phylogenetic sweep, genome size may be correlated with intron size (Deutsch and Long 1999; Vinogradov 1999; McLysaght et al. 2000), suggesting that some component of genome...

  4. Sauropod dinosaurs evolved moderately sized genomes unrelated to body size.

    Science.gov (United States)

    Organ, Chris L; Brusatte, Stephen L; Stein, Koen

    2009-12-22

    Sauropodomorph dinosaurs include the largest land animals to have ever lived, some reaching up to 10 times the mass of an African elephant. Despite their status defining the upper range for body size in land animals, it remains unknown whether sauropodomorphs evolved larger-sized genomes than non-avian theropods, their sister taxon, or whether a relationship exists between genome size and body size in dinosaurs, two questions critical for understanding broad patterns of genome evolution in dinosaurs. Here we report inferences of genome size for 10 sauropodomorph taxa. The estimates are derived from a Bayesian phylogenetic generalized least squares approach that generates posterior distributions of regression models relating genome size to osteocyte lacunae volume in extant tetrapods. We estimate that the average genome size of sauropodomorphs was 2.02 pg (range of species means: 1.77-2.21 pg), a value in the upper range of extant birds (mean = 1.42 pg, range: 0.97-2.16 pg) and near the average for extant non-avian reptiles (mean = 2.24 pg, range: 1.05-5.44 pg). The results suggest that the variation in size and architecture of genomes in extinct dinosaurs was lower than the variation found in mammals. A substantial difference in genome size separates the two major clades within dinosaurs, Ornithischia (large genomes) and Saurischia (moderate to small genomes). We find no relationship between body size and estimated genome size in extinct dinosaurs, which suggests that neutral forces did not dominate the evolution of genome size in this group.

  5. Scaling beta-delayed neutron measurements to large detector areas

    Science.gov (United States)

    Sutanto, F.; Nattress, J.; Jovanovic, I.

    2017-08-01

    We explore the performance of a cargo screening system that consists of two large-sized composite scintillation detectors and a high-energy neutron interrogation source by modeling and simulation. The goal of the system is to measure β-delayed neutron emission from an illicit special nuclear material by use of active interrogation. This task is challenging because the β-delayed neutron yield is small in comparison with the yield of the prompt fission secondary products, β-delayed neutrons are emitted with relatively low energies, and high neutron and gamma backgrounds are typically present. Detectors used to measure delayed neutron emission must exhibit high intrinsic efficiency and cover a large solid angle, which also makes them sensitive to background neutron radiation. We present a case study where we attempt to detect the presence of 5 kg-scale quantities of 235U in a standard air-filled cargo container using 14 MeV neutrons as a probe. We find that by using a total measurement time of ˜11.6 s and a dose equivalent of ˜1.7 mrem, the presence of 235U can be detected with false positive and false negative probabilities that are both no larger than 0.1%.

  6. Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation.

    Science.gov (United States)

    Shaw, P; Eckstrand, K; Sharp, W; Blumenthal, J; Lerch, J P; Greenstein, D; Clasen, L; Evans, A; Giedd, J; Rapoport, J L

    2007-12-04

    There is controversy over the nature of the disturbance in brain development that underpins attention-deficit/hyperactivity disorder (ADHD). In particular, it is unclear whether the disorder results from a delay in brain maturation or whether it represents a complete deviation from the template of typical development. Using computational neuroanatomic techniques, we estimated cortical thickness at >40,000 cerebral points from 824 magnetic resonance scans acquired prospectively on 223 children with ADHD and 223 typically developing controls. With this sample size, we could define the growth trajectory of each cortical point, delineating a phase of childhood increase followed by adolescent decrease in cortical thickness (a quadratic growth model). From these trajectories, the age of attaining peak cortical thickness was derived and used as an index of cortical maturation. We found maturation to progress in a similar manner regionally in both children with and without ADHD, with primary sensory areas attaining peak cortical thickness before polymodal, high-order association areas. However, there was a marked delay in ADHD in attaining peak thickness throughout most of the cerebrum: the median age by which 50% of the cortical points attained peak thickness for this group was 10.5 years (SE 0.01), which was significantly later than the median age of 7.5 years (SE 0.02) for typically developing controls (log rank test chi(1)(2) = 5,609, P processes including attention and motor planning. Neuroanatomic documentation of a delay in regional cortical maturation in ADHD has not been previously reported.

  7. Prognostic significance of delayed intraventricular haemorrhage in the INTERACT studies.

    Science.gov (United States)

    Moullaali, Tom J; Sato, Shoichiro; Wang, Xia; Rabinstein, Alejandro A; Arima, Hisatomi; Carcel, Cheryl; Chen, Guofang; Robinson, Thompson; Heeley, Emma; Chan, Edward; Delcourt, Candice; Stapf, Christian; Cordonnier, Charlotte; Lindley, Richard I; Chalmers, John; Anderson, Craig S

    2017-01-01

    Intraventricular extension of intracerebral haemorrhage (ICH) predicts poor outcome, but the significance of delayed intraventricular haemorrhage (dIVH) is less well defined. We determined the prognostic significance of dIVH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trials (INTERACT 1 and 2). Pooled analyses of the INTERACT CT substudies-international, multicentre, prospective, open, blinded end point, randomised controlled trials of patients with acute spontaneous ICH and elevated systolic blood pressure (SBP)-randomly assigned to intensive (<140 mm Hg) or guideline-based (<180 mm Hg) SBP management. Participants had blinded central analyses of baseline and 24 h CTs, with dIVH defined as new intraventricular haemorrhage (IVH) on the latter scan. Outcomes of death and major disability were defined by modified Rankin Scale scores at 90 days. There were 349 (27%) of 1310 patients with baseline IVH, and 107 (11%) of 961 initially IVH-free patients who developed dIVH. Significant associations of dIVH were prior warfarin anticoagulation, high (≥15) baseline National Institutes of Health Stroke Scale score, larger (≥15 mL) ICH volume, greater ICH growth and higher achieved SBP over 24 h. Compared with those who were IVH-free, dIVH had greater odds of 90-day death or major disability versus initial IVH (adjusted ORs 2.84 (95% CI 1.52 to 5.28) and 1.87 (1.36 to 2.56), respectively (p trend <0.0001)). Although linked to factors determining greater ICH growth including poor SBP control, dIVH is independently associated with poor outcome in acute small to moderate-size ICH. NCT00226096 and NCT00716079. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Delayed response in ipilimumab therapy.

    Science.gov (United States)

    Megahed, Ahmed; Faulhaber, Peter; Phillips, Tycel; Koon, Henry

    2014-03-01

    Metastatic melanoma is a deadly disease with a 5-year survival rate lower than 20%. In 2011, ipilimumab, a fully humanized antibody that binds to cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) was approved by the US Food and Drug Administration based on improved survival in a pivotal trial. CTLA4 is a molecule on cytotoxic T-lymphocytes that plays a critical role in attenuating immune responses. Ipilimumab blocks the binding of B7, the ligand of CTLA4, thereby blocking the activation of CTLA4 and sustaining antitumor immune responses. The time course to response can be variable with immunotherapeutics. We report on a patient who experienced a considerable delay before responding to ipilimumab.

  9. Does one size really fit all? The effectiveness of a non-diagnosis-specific integrated mental health care program in Germany in a prospective, parallel-group controlled multi-centre trial.

    Science.gov (United States)

    Mueller-Stierlin, Annabel Sandra; Helmbrecht, Marina Julia; Herder, Katrin; Prinz, Stefanie; Rosenfeld, Nadine; Walendzik, Julia; Holzmann, Marco; Dinc, Uemmueguelsuem; Schützwohl, Matthias; Becker, Thomas; Kilian, Reinhold

    2017-08-01

    The Network for Mental Health (NWpG-IC) is an integrated mental health care program implemented in 2009 by cooperation between health insurance companies and community mental health providers in Germany. Meanwhile about 10,000 patients have been enrolled. This is the first study evaluating the effectiveness of the program in comparison to standard mental health care in Germany. In a parallel-group controlled trial over 18 months conducted in five regions across Germany, a total of 260 patients enrolled in NWpG-IC and 251 patients in standard mental health care (TAU) were recruited between August 2013 and November 2014. The NWpG-IC patients had access to special services such as community-based multi-professional teams, case management, crisis intervention and family-oriented psychoeducation in addition to standard mental health care. The primary outcome empowerment (EPAS) and the secondary outcomes quality of life (WHO-QoL-BREF), satisfaction with psychiatric treatment (CSQ-8), psychosocial and clinical impairment (HoNOS) and information about mental health service needs (CAN) were measured four times at 6-month intervals. Linear mixed-effect regression models were used to estimate the main effects and interaction effects of treatment, time and primary diagnosis. Due to the non-randomised group assignment, propensity score adjustment was used to control the selection bias. NWpG-IC and TAU groups did not differ with respect to most primary and secondary outcomes in our participating patients who showed a broad spectrum of psychiatric diagnoses and illness severities. However, a significant improvement in terms of patients' satisfaction with psychiatric care and their perception of treatment participation in favour of the NWpG-IC group was found. Providing integrated mental health care for unspecific mentally ill target groups increases treatment participation and service satisfaction but seems not suitable to enhance the overall outcomes of mental health care in

  10. 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.

  11. Delay and Disruption Tolerant Networking MACHETE Model

    Science.gov (United States)

    Segui, John S.; Jennings, Esther H.; Gao, Jay L.

    2011-01-01

    To verify satisfaction of communication requirements imposed by unique missions, as early as 2000, the Communications Networking Group at the Jet Propulsion Laboratory (JPL) saw the need for an environment to support interplanetary communication protocol design, validation, and characterization. JPL's Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE), described in Simulator of Space Communication Networks (NPO-41373) NASA Tech Briefs, Vol. 29, No. 8 (August 2005), p. 44, combines various commercial, non-commercial, and in-house custom tools for simulation and performance analysis of space networks. The MACHETE environment supports orbital analysis, link budget analysis, communications network simulations, and hardware-in-the-loop testing. As NASA is expanding its Space Communications and Navigation (SCaN) capabilities to support planned and future missions, building infrastructure to maintain services and developing enabling technologies, an important and broader role is seen for MACHETE in design-phase evaluation of future SCaN architectures. To support evaluation of the developing Delay Tolerant Networking (DTN) field and its applicability for space networks, JPL developed MACHETE models for DTN Bundle Protocol (BP) and Licklider/Long-haul Transmission Protocol (LTP). DTN is an Internet Research Task Force (IRTF) architecture providing communication in and/or through highly stressed networking environments such as space exploration and battlefield networks. Stressed networking environments include those with intermittent (predictable and unknown) connectivity, large and/or variable delays, and high bit error rates. To provide its services over existing domain specific protocols, the DTN protocols reside at the application layer of the TCP/IP stack, forming a store-and-forward overlay network. The key capabilities of the Bundle Protocol include custody-based reliability, the ability to cope with intermittent connectivity

  12. Menstrual management in developmentally delayed adolescent females.

    Science.gov (United States)

    Chuah, Irene; McRae, Alexandra; Matthews, Kim; Maguire, Ann M; Steinbeck, Katharine

    2017-06-01

    Requests for assistance in menstrual management and menstrual suppression are a common, emotive and sometimes controversial aspect of adolescent disability care. To review the uptake and outcomes of menstrual suppression among adolescent patients with developmental delay. A retrospective review of the medical records of adolescent females with intellectual disability referred for menstrual management to the Paediatric and Adolescent Gynaecology Clinic, Children's Hospital at Westmead, Sydney, for the three-year period between January 1, 2010 and January 1, 2013. Eighty adolescent patients with developmental delay were identified. A third (n = 28) of the patients were pre-menarcheal at first review with parent/caregivers seeking anticipatory advice. Of the post-menarcheal patients, the median age of menarche was 12 years (range 10-15 years). First and second line interventions were documented as were reasons for change where applicable. The combined oral contraceptive pill (COCP) was the most frequently used therapy (67%), and 19 patients in total had a levonorgestrel releasing intrauterine system (LNG-IUS) inserted (31%). Our study population differs from similar previously published groups in the marked absence of the use of depot medroxyprogesterone acetate or the subdermal etonogestrel releasing device. As a paediatrician, it is important to address menstrual management issues and allay caregiver concerns with appropriate advice. Our study supports the use of the COCP as sound first line management in achieving menstrual suppression. The LNG-IUS appears to be a favourable second line option. Further investigation into longer-term outcomes and potential complications of device insertion is recommended. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  13. Decomposing the dynamics of heterogeneous delayed networks with applications to connected vehicle systems.

    Science.gov (United States)

    Szalai, Róbert; Orosz, Gábor

    2013-10-01

    Delay-coupled networks are investigated with nonidentical delay times and the effects of such heterogeneity on the emergent dynamics of complex systems are characterized. A simple decomposition method is presented that decouples the dynamics of the network into node-size modal equations in the vicinity of equilibria. The resulting independent components contain distributed delays that map the spatiotemporal complexity of the system to the time domain. We demonstrate that this approach can be used to reveal physical phenomena in heterogenous vehicular traffic when vehicles are linked via vehicle-to-vehicle communication.

  14. A Full-Bandwidth Audio Codec with Low Complexity and Very Low Delay

    OpenAIRE

    Maxwell, Gregory; Terriberry, Timothy; Valin, Jean-Marc

    2009-01-01

    We propose an audio codec that addresses the low-delay requirements of some applications such as network music performance. The codec is based on the modified discrete cosine transform (MDCT) with very short frames and uses gain-shape quantization to preserve the spectral envelope. The short frame sizes required for low delay typically hinder the performance of transform codecs. However, at 96 kbit/s and with only 4 ms algorithmic delay, the proposed codec out-performs the ULD codec operating...

  15. 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.

  16. Making Cooperative Learning Groups Work.

    Science.gov (United States)

    Hawley, James; De Jong, Cherie

    1995-01-01

    Discusses the use of cooperative-learning groups with middle school students. Describes cooperative-learning techniques, including group roles, peer evaluation, and observation and monitoring. Considers grouping options, including group size and configuration, dyads, the think-pair-share lecture, student teams achievement divisions, jigsaw groups,…

  17. Group purchasing: an overview.

    Science.gov (United States)

    Wetrich, J G

    1987-07-01

    The various types and operational methods of purchasing groups are described, and evaluation of groups is discussed. Since group purchasing is increasing in popularity as a method of controlling drug costs, community and hospital pharmacy managers may need to evaluate various groups to determine the appropriateness of their services. Groups are categorized as independent, system based, or alliance or association based. Instead of "purchasing," some groups develop contracts for hospitals, which then purchase directly from the vendor. Aside from this basic difference between groups that purchase and groups that contract, comparisons among groups are difficult because of the wide variation in sizes and services. Competition developing from diversification among groups has led to "super groups," formed from local and regional groups. In evaluating groups, advantages and disadvantages germane to accomplishing the member's objectives must be considered. To ensure a group's success, members must be committed and support the group's philosophies; hospital pharmacists must help to establish a strong formulary system. To select vendors, groups should develop formal qualification and selection criteria and should not base a decision solely on price. The method of solicitation (bidding or negotiating), as well as the role of the prime vendor, should be studied. Legal implications of group purchasing, especially in the areas of administrative fees and drug diversion, must also be considered. The most advantageous group for each organization will include members with common missions and will be able to implement strategies for future success.

  18. Memory Reduction via Delayed Simulation

    Directory of Open Access Journals (Sweden)

    Michael Holtmann

    2011-02-01

    Full Text Available We address a central (and classical issue in the theory of infinite games: the reduction of the memory size that is needed to implement winning strategies in regular infinite games (i.e., controllers that ensure correct behavior against actions of the environment, when the specification is a regular omega-language. We propose an approach which attacks this problem before the construction of a strategy, by first reducing the game graph that is obtained from the specification. For the cases of specifications represented by "request-response"-requirements and general "fairness" conditions, we show that an exponential gain in the size of memory is possible.

  19. 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.

  20. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  1. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23¿days (0-17¿months) and median health care delay of 94¿days (1-40¿months) with delays of median 15¿days...

  2. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23 days (0-17 months) and median health care delay of 94 days (1-40 months) with delays of median 15 days...

  3. 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.

  4. Permutation entropy with vector embedding delays

    Science.gov (United States)

    Little, Douglas J.; Kane, Deb M.

    2017-12-01

    Permutation entropy (PE) is a statistic used widely for the detection of structure within a time series. Embedding delay times at which the PE is reduced are characteristic timescales for which such structure exists. Here, a generalized scheme is investigated where embedding delays are represented by vectors rather than scalars, permitting PE to be calculated over a (D -1 ) -dimensional space, where D is the embedding dimension. This scheme is applied to numerically generated noise, sine wave and logistic map series, and experimental data sets taken from a vertical-cavity surface emitting laser exhibiting temporally localized pulse structures within the round-trip time of the laser cavity. Results are visualized as PE maps as a function of embedding delay, with low PE values indicating combinations of embedding delays where correlation structure is present. It is demonstrated that vector embedding delays enable identification of structure that is ambiguous or masked, when the embedding delay is constrained to scalar form.

  5. Stochastic Hopf bifurcation in transcription networks with delayed feedback

    Science.gov (United States)

    Wentworth, John; Gaudreault, Mathieu; Vinals, Jorge

    2012-02-01

    We study the oscillatory instabilities of two model systems that rely on delayed negative feedback to induce oscillation: a single gene auto repressor system, and a dimer negative autoregulation system. We focus on fluctuations of intrinsic origin in the range of low copy number. The bifurcation diagram is obtained for these stochastic models, and shown to differ significantly from that of a macroscopic description that neglects fluctuations. Bifurcation lines remain sharp under fluctuations, but their location is a function of the relative size of the fluctuations. Shifts in the stability threshold of the oscillators can be traced back to the interplay between statistical correlations and delayed feedback. We finally show that there results cannot be captured by weak noise approximations (the diffusion limit), but instead result from strong fluctuations associated with low copy numbers.

  6. Price regulation and relative delays in generic drug adoption.

    Science.gov (United States)

    Costa-Font, Joan; McGuire, Alistair; Varol, Nebibe

    2014-12-01

    Increasing the adoption of generic drugs has the potential to improve static efficiency in a health system without harming pharmaceutical innovation. However, very little is known about the timing of generic adoption and diffusion. No prior study has empirically examined the differential launch times of generics across a comprehensive set of markets, or more specifically the delays in country specific adoption of generics relative to the first country of (generic) adoption. Drawing on data containing significant country and product variation across a lengthy time period (1999-2008), we use duration analysis to examine relative delays, across countries, in the adoption of generic drugs. Our results suggest that price regulation has a significant effect on reducing the time to launch of generics, with faster adoption in higher priced markets. The latter result is dependent on the degree of competition and the expected market size. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. 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.

  8. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    by numerical analysis with simulation. This paper proposes an analytical estimate of aggregate delay with a polynomial form. The function returns the aggregate delay of a railway line resulting from an initial, primary, delay. Analysis of the function demonstrates that there should be a balance between the two...... remedial measures, supplement and buffer. Numerical analysis of a Copenhagen Sbane line shows that the polynomial function is valid even when theoretical assumptions are violated....

  9. Stability investigation of quadratic systems with delay

    Directory of Open Access Journals (Sweden)

    Vladimir Davydov

    2000-01-01

    Full Text Available Systems of differential equations with quadratic right-hand sides with delay are considered in the paper. Compact matrix notation form is proposed for the systems of such type. Stability investigations are performed by Lyapunov's second method with functions of quadratic form. Stability conditions of quadratic systems with delay, uniformly by argument deviation, and with delay depending on the system's parameters are derived. A guaranteed radius of the ball of asymptotic stability region for zero solution is obtained.

  10. 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)

  11. Faktor - Faktor Yang Mempengaruhi Audit Delay

    OpenAIRE

    Christine Tamba

    2010-01-01

    The aim for this study to investigate the influence of right issue, financial leverage, audit committee education, firm performance and audit opinion on audit delay. The samples consist of listed manufactured firms from 2005 to 2009. The results show that tight issue, audit committee education, and firm leverage significantly influence on audit delay. But, audit opinion and financial leverage do not significantly influence on audit delay. Keywords : Right isisue, Leverage, Education, Perfo...

  12. 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.

  13. Patient Related Factors Associated with Delayed Reporting in Oral Cavity and Oropharyngeal Cancer

    Directory of Open Access Journals (Sweden)

    Mohammad Akram

    2014-01-01

    Conclusions: The results of this study provide guidance towards interventions to reduce patient delay. Interventions should target the rural, older age group and lower socioeconomic population for educating them and to change their psychosocial behavior for oral and oropharyngeal cancer.

  14. Neutron stochastic transport theory with delayed neutrons

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Verdu, G.

    1987-01-01

    From the stochastic transport theory with delayed neutrons, the Boltzmann transport equation with delayed neutrons for the average flux emerges in a natural way without recourse to any approximation. From this theory a general expression is obtained for the Feynman Y-function when delayed neutrons are included. The single mode approximation for the particular case of a subcritical assembly is developed, and it is shown that Y-function reduces to the familiar expression quoted in many books, when delayed neutrons are not considered, and spatial and source effects are not included. (author)

  15. 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

  16. Delayed stenosis following stentriever use in acute stroke intervention.

    Science.gov (United States)

    Macke, Jeremy James; Bellew, Michael P; Hellinger, Frank R

    2015-05-01

    We report two cases of delayed post-embolectomy stenosis--that is, a new stenosis in the vascular bed of a previous endovascular embolectomy. The first case was discovered incidentally in a patient returning after embolectomy for evaluation of cerebral aneurysms. The second case was discovered on an MR angiogram obtained to screen for stenosis. This was prompted by our experience with the first case. To our knowledge, this phenomenon has not been reported previously. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. The impact of immediate or delayed feedback on driving behaviour in a simulated Pay-As-You-Drive system.

    Science.gov (United States)

    Dijksterhuis, Chris; Lewis-Evans, Ben; Jelijs, Bart; de Waard, Dick; Brookhuis, Karel; Tucha, Oliver

    2015-02-01

    Pay-As-You-Drive (PAYD) insurance links an individual's driving behaviour to the insurance fee that they pay, making car insurance more actuarially accurate. The best known PAYD insurance format is purely mileage based and is estimated to reduce accidents by about 15% (Litman, 2011). However, these benefits could be further enhanced by incorporating a wider range of driving behaviours, such as lateral and longitudinal accelerations and speeding behaviour, thereby stimulating not only a safe but also an eco-friendly driving style. Currently, feedback on rewards and driver behaviour is mostly provided through a web-based interface, which is presented temporally separated from driving. However, providing immediate feedback within the vehicle itself could elicit more effect. To investigate this hypothesis, two groups of 20 participants drove with a behavioural based PAYD system in a driving simulator and were provided with either delayed feedback through a website, or immediate feedback through an in-car interface, allowing them to earn up to €6 extra. To be clear, every participant in the web group did actually view their feedback during the one week between sessions. Results indicate clear driving behaviour improvements for both PAYD groups as compared to baseline rides and an equal sized control group. After both PAYD groups had received feedback, the initial advantage of the in-car group was reduced substantially. Taken together with usability ratings and driving behaviours in specific situations these results show a moderate advantage of using immediate in-car feedback. However, the study also showed that under conditions of feedback certainty, the effectiveness of delayed feedback approaches that of immediate feedback as compared to a naïve control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Survival of immediately versus delayed loaded short implants: A prospective case series study

    OpenAIRE

    Alvira-Gonz?lez, Joaquin; D?az-Campos, Erick; S?nchez-Garc?s, Maria-Angeles; Gay-Escoda, Cosme

    2015-01-01

    Background To assess and compare survival rates of immediately and delayed loaded short implants (7 mm) in free ends of a partially edentulous jaw with moderate-severe alveolar bone resorption. Material and Methods 24 patients with atrophic edentulous free-ends were included in this prospective study. Four study groups were monitored monthly and their behavior was evaluated: bridges supported only by short implants and mixed short and long implant bridge groups, both with immediate and delaye...

  19. Analysis of the causes and effects of delay before diagnosis using surgical mortality data.

    Science.gov (United States)

    North, J B; Blackford, F J; Wall, D; Allen, J; Faint, S; Ware, R S; Rey-Conde, T

    2013-02-01

    The aim of the study was to assess the causes and effects of delay in diagnosis in surgical patients who died in 20 public hospitals participating in the Queensland Audit of Surgical Mortality (QASM) in Australia. This was a retrospective cross-sectional analysis (June 2007 to December 2011) of deaths reported to QASM. Deaths were assigned to one of two groups (no delay or delay in diagnosis). Logistic regression was used to compare the association of delay with surgical complications, both overall and by surgical specialty. A total of 3139 deaths were reported. Diagnostic delay was reported in 293 (9·3 per cent). The primary cause of delay was attributed to diagnostic support services (41·7 per cent). Some 174 (13·8 per cent) of 1259 general (gastrointestinal) surgery patients experienced delayed diagnosis. Delay across all surgical specialties was associated with an increased risk of unplanned return to theatre (odds ratio (OR) 1·77, 95 per cent confidence interval 1·24 to 2·52), of being treated in intensive care (OR 1·71, 1·15 to 2·54) and of postoperative complications (OR 1·39, 1·05 to 1·85). General (gastrointestinal) surgery patients who experienced delayed diagnosis were at increased risk of postoperative complications. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  20. 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

  1. 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

  2. Factors affecting delayed walking skill in malnourished children.

    Science.gov (United States)

    Ojofeitimi, E O; Elegbe, I; Jinadu, M K; Oladipo, C A

    1984-01-01

    This research examined children between 13 and 23 months of age with developmental delays in walking. Children in the experimental group received intensive infant stimulation and, subsequently approximately 71% were able to walk by themselves. In contrast, 32% of those children receiving only verbal instruction were able to achieve this important milestone. There was a significant difference (p less than 0.05) between the control and experimental group in acquiring walking skills. Mothers' lack of awareness about infant stimulation and lack of supervision on the part of health workers are the major contributing factors to delayed walking skill in these children. The study highlights the importance of taking health care to the home of clients, the most neglected aspect of primary health in this part of the world.

  3. [Delayed posthypoxic leukoencephalopathy: case reports].

    Science.gov (United States)

    Okuda, Shiho; Ueno, Masao; Hayakawa, Michiko; Araki, Manabu; Kanda, Fumio; Takano, Shin

    2012-01-01

    Delayed posthypoxic leukoencephalopathy (DPL) is a rare and less well known complication of hypoxic brain injury. Although it is well known that anoxic or hypoxic injury produces acute neurologic deficits, DPL typically manifests days to weeks after apparent recovery from an obtunded state, and patients with DPL demonstrate cognitive impairment, high brain dysfunction, parkinsonism, or psychosis. MRI findings of the brain demonstrate deep white matter abnormalities. We report 2 cases of DPL after hypoxia due to benzodiazepine overdose. Both of our patients had normal arylsulfatase A activity. Although DPL is seen in carbon monoxide poisoning, pseudodeficiency of arylsulfatase A activity, or drug overdose with heroin or morphine, there are only some previous studies of DPL caused by an overdose with benzodiazepine. It is unclear whether neurotoxicity from the drug in addition to hypoxia alone is involved, however, it is important to note that overdose of common drugs as sleeping medicine can cause DPL. Since DPL may often be misdiagnosed and be subjected to unnecessary treatments, it is also important to understand its unique clinical course and MRI findings. With prompt recognition of DPL, we expect that more cases of DPL caused by overdose with benzodiazepine will be diagnosed, because benzodiazepine overdoses are common.

  4. Delayed Orthostatic Hypotension: A Pilot Study from India.

    Science.gov (United States)

    Roy, Arun Grace; Gopinath, Siby; Kumar, Suresh; Kannoth, Sudheeran; Kumar, Anand

    2017-01-01

    Orthostatic hypotension is defined as a sustained decrease in systolic blood pressure of 20 mm Hg or a decrease in diastolic blood pressure of 10 mm Hg within three minutes of standing compared with blood pressure from the sitting or supine position or by head-up tilt-table testing (1). When sustained blood pressure (BP) drop is after three minutes of upright posture it is called delayed orthostatic hypotension (delayed OH) (2). To detect the incidence of delayed orthostatic hypotension in patients referred to our autonomic lab. BP was measured noninvasively at 1-minute intervals with an automated cuff sphygmomanometer over the right brachial artery for 45 minutes. The onset and duration of falls in blood pressure either systolic or diastolic or both were documented, and any associated symptoms were recorded. Only patients with sustained falls in BP were included. Drugs causing OH was stopped 48 hours before testing as per protocol followed in lab. We also looked into other autonomic function test abnormalities in patients with delayed OH. Patients above age of 18 years referred for evaluation of autonomic function tests. Patients with severe cardiac failure and cardiac arrhythmias were excluded and patients with rapid fall in BP and bradycardia (Neurally mediated syncope) were excluded. Total 170 patients underwent tilt table testing. Orthostatic hypotension was seen within 3 minutes in seventy patients, fifty patients had delayed OH (BP fall after 3 minutes). There were twenty seven males and twenty three females in this group. Twenty nine of the 50 patients with delayed orthostatic hypotension, had symptoms during the tilt table procedure. Asymptomatic OH was more common in patients who developed OH after 10 minutes. This is a pilot study, first in India where we looked into the incidence of delayed orthostatic hypotension in patients undergoing tilt table testing in our autonomic lab. We found that fifty patients had delayed orthostatic hypotension which could

  5. 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.

  6. 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.

  7. A case-control study investigating factors of preoperative delay in emergency laparotomy.

    Science.gov (United States)

    Schneider, Crispin; Tyler, Laura E; Scull, Eleanor F; Pryle, Belinda J; Barr, Hugh

    2015-10-01

    Emergency laparotomy (EL) is a procedure that puts a strain on healthcare resources and is associated with a significant morbidity and mortality. Despite these implications little improvement in the outcome of patients undergoing this procedure has been made in the UK over the last few decades. A delay in transferring patients to theatre has been shown to negatively affect outcome of EL. A prospective case-control study was carried out to evaluate which preoperative factors may contribute towards a delay in theatre transfer. The time between decision to operate and anaesthetic start time was recorded for all patients undergoing EL between April and September 2013 at Gloucestershire Royal Infirmary. Patient selection criteria were based on the National Emergency Laparotomy Audit guidelines. Patients were divided into two groups depending on whether the transfer to theatre was delayed or not. Binary logistic regression analysis was performed on perioperative factors to determine independent predictors of delay. A total of 84 EL were included for analyses with 31 classified as delayed. In the delayed group time for theatre transfer was increased at 6.9 vs. 2.3 h (p delay (n = 24). On binary logistic regression analysis, indication for laparotomy (OR 4.96, CI 1.4-17.6, p delay in EL. In this study, factors that were associated with a delay in commencing EL were operative indication and patient age whereas the presence of a consultant surgeon made a delay less likely. These findings may highlight points of interest for researchers analysing and auditing the provision of EL in the UK. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  8. Broadband hyperchaotic oscillator with delay line

    DEFF Research Database (Denmark)

    Cenys, Antanas; Lindberg, Erik; Anagnostopoulos, A. N.

    2002-01-01

    Dynamical systems with time delay can be employed as high dimensional hyperchaotic oscillators with multiple positive Lyapunov exponents. We describe an electronic circuit composed of a 3-stage amplifier and a delay line in the feedback loop. The 1st stage of the amplifier is a nonlinear one while...

  9. Programmable delay circuit for sparker signal analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, D.

    on it to classify the seafloor sediment properties. A specific purpose oriented programmable delay circuit was developed to generate the necessary delay so that the A/D conversion could start just before the arrival of the echo from the water bottom interface...

  10. Discounting of Delayed Rewards Is Not Hyperbolic

    Science.gov (United States)

    Luhmann, Christian C.

    2013-01-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

  11. Action for delayed neutron data evaluation

    International Nuclear Information System (INIS)

    Okajima, Shigeaki

    1999-01-01

    Status of NEA/NSC/WPEC/SG6 activities on delayed neutron data evaluation is shortly reviewed. From this review the actions in evaluating the delayed neutron data are proposed to contribute the revise work for the JENDL-3.3 library. (author)

  12. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  13. Recursive Delay Calculation Unit for Parametric Beamformer

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt; Tomov, Borislav Gueorguiev

    2006-01-01

    This paper presents a recursive approach for parametric delay calculations for a beamformer. The suggested calculation procedure is capable of calculating the delays for any image line defined by an origin and arbitrary direction. It involves only add and shift operations making it suitable...

  14. 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 have...

  15. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  16. On Delay and Security in Network Coding

    Science.gov (United States)

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  17. Algebraic entropy for differential-delay equations

    OpenAIRE

    Viallet, Claude M.

    2014-01-01

    We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

  18. Performance characteristics of positive and negative delayed ...

    Indian Academy of Sciences (India)

    The chaotic dynamics of directly modulated semiconductor lasers with delayed optoelectronic feedback is studied numerically. The effects of positive and negative delayed optoelectronic feedback in producing chaotic outputs from such lasers with nonlinear gain reduction in its optimum value range is investigated using ...

  19. Delaying Developmental Mathematics: The Characteristics and Costs

    Science.gov (United States)

    Johnson, Marianne; Kuennen, Eric

    2004-01-01

    This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

  20. Delaying gratification depends on social trust

    Directory of Open Access Journals (Sweden)

    Laura eMichaelson

    2013-06-01

    Full Text Available Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then chose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity.