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Sample records for optimal vigilance hypothesis

  1. The venom optimization hypothesis revisited.

    Science.gov (United States)

    Morgenstern, David; King, Glenn F

    2013-03-01

    Animal venoms are complex chemical mixtures that typically contain hundreds of proteins and non-proteinaceous compounds, resulting in a potent weapon for prey immobilization and predator deterrence. However, because venoms are protein-rich, they come with a high metabolic price tag. The metabolic cost of venom is sufficiently high to result in secondary loss of venom whenever its use becomes non-essential to survival of the animal. The high metabolic cost of venom leads to the prediction that venomous animals may have evolved strategies for minimizing venom expenditure. Indeed, various behaviors have been identified that appear consistent with frugality of venom use. This has led to formulation of the "venom optimization hypothesis" (Wigger et al. (2002) Toxicon 40, 749-752), also known as "venom metering", which postulates that venom is metabolically expensive and therefore used frugally through behavioral control. Here, we review the available data concerning economy of venom use by animals with either ancient or more recently evolved venom systems. We conclude that the convergent nature of the evidence in multiple taxa strongly suggests the existence of evolutionary pressures favoring frugal use of venom. However, there remains an unresolved dichotomy between this economy of venom use and the lavish biochemical complexity of venom, which includes a high degree of functional redundancy. We discuss the evidence for biochemical optimization of venom as a means of resolving this conundrum. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Motivation in vigilance - A test of the goal-setting hypothesis of the effectiveness of knowledge of results.

    Science.gov (United States)

    Warm, J. S.; Riechmann, S. W.; Grasha, A. F.; Seibel, B.

    1973-01-01

    This study tested the prediction, derived from the goal-setting hypothesis, that the facilitating effects of knowledge of results (KR) in a simple vigilance task should be related directly to the level of the performance standard used to regulate KR. Two groups of Ss received dichotomous KR in terms of whether Ss response times (RTs) to signal detections exceeded a high or low standard of performance. The aperiodic offset of a visual signal was the critical event for detection. The vigil was divided into a training phase followed by testing, during which KR was withdrawn. Knowledge of results enhanced performance in both phases. However, the two standards used to regulate feedback contributed little to these effects.

  3. The Effects of Social Anxiety and State Anxiety on Visual Attention: Testing the Vigilance-Avoidance Hypothesis.

    Science.gov (United States)

    Singh, J Suzanne; Capozzoli, Michelle C; Dodd, Michael D; Hope, Debra A

    2015-01-01

    A growing theoretical and research literature suggests that trait and state social anxiety can predict attentional patterns in the presence of emotional stimuli. The current study adds to this literature by examining the effects of state anxiety on visual attention and testing the vigilance-avoidance hypothesis, using a method of continuous visual attentional assessment. Participants were 91 undergraduate college students with high or low trait fear of negative evaluation (FNE), a core aspect of social anxiety, who were randomly assigned to either a high or low state anxiety condition. Participants engaged in a free view task in which pairs of emotional facial stimuli were presented and eye movements were continuously monitored. Overall, participants with high FNE avoided angry stimuli and participants with high state anxiety attended to positive stimuli. Participants with high state anxiety and high FNE were avoidant of angry faces, whereas participants with low state and low FNE exhibited a bias toward angry faces. The study provided partial support for the vigilance-avoidance hypothesis. The findings add to the mixed results in the literature that suggest that both positive and negative emotional stimuli may be important in understanding the complex attention patterns associated with social anxiety. Clinical implications and suggestions for future research are discussed.

  4. The hubris hypothesis: The downside of comparative optimism displays.

    Science.gov (United States)

    Hoorens, Vera; Van Damme, Carolien; Helweg-Larsen, Marie; Sedikides, Constantine

    2017-04-01

    According to the hubris hypothesis, observers respond more unfavorably to individuals who express their positive self-views comparatively than to those who express their positive self-views non-comparatively, because observers infer that the former hold a more disparaging view of others and particularly of observers. Two experiments extended the hubris hypothesis in the domain of optimism. Observers attributed less warmth (but not less competence) to, and showed less interest in affiliating with, an individual displaying comparative optimism (the belief that one's future will be better than others' future) than with an individual displaying absolute optimism (the belief that one's future will be good). Observers responded differently to individuals displaying comparative versus absolute optimism, because they inferred that the former held a gloomier view of the observers' future. Consistent with previous research, observers still attributed more positive traits to a comparative or absolute optimist than to a comparative or absolute pessimist. Copyright © 2016. Published by Elsevier Inc.

  5. The old age security hypothesis and optimal population growth.

    Science.gov (United States)

    Bental, B

    1989-03-01

    The application of the Samuelson-Diamond overlapping generations framework to the old age security hypothesis indicates that government intervention schemes can influence the relationship between population growth and capital accumulation. The most direct means of optimizing population growth is through taxes or subsidies that relate to the intergenerational transfer of wealth. A pay-as-you-go social security scheme, in which payment is predicated on the number of children the receiver has and is financed by taxes levied on the working population, emerges as the most likely intervention to produce the optimal steady state equilibrium. This system is able to correct any distortions the private sector may build into it. In contrast, a child support system, in which the government subsidizes or taxes workers according to their family size, can guarantee the optimal capital:labor ratio but not the optimal population growth rate. Thus, if the government seeks to decrease the population growth rate, the appropriate intervention is to levy a lump-sum social-security tax on workers and transfer the revenues to the old; the direction should be reversed if the goal is to increase population growth. Another alternative, a lump sum social security system, can guarantee optimal population growth but not a desirable capital:labor ratio. Finally, the introduction of money as a valued commodity into an economy with a high capital:labor ratio will also serve to decrease the population growth rate and solve the intergenerational transfer problem through the private sector without any need for government intervention.

  6. Vigilance, sleep and epilepsy.

    Science.gov (United States)

    Vieth, J

    1986-01-01

    The correlations between vigilance and epilepsy are manifold. Nearly all epileptic seizures cause a diminution of vigilance extending to unconsciousness. Many of the influences triggering or inhibiting epileptic seizures produce alterations of vigilance or are produced by them. Nearly all chemical influences more or less cause diminution of vigilance. The enhancement of vigilance may inhibit seizures. Decreasing vigilance may act vice versa. As a means to enhance vigilance afferent stimuli are able to trigger seizures. This may be accomplished when singular or rhythmic stimulation of afferents gets the already excited neuronal system oscillating. This principle is also responsible for the strong correlation between triggering of seizures and the sleep/waking cycle with its different grades of neuronal synchronization. On the other hand, inhibition of seizures is possible by a continuously applied stimulation load, which may disturb the increasing excitatory oscillation. Also, conditioning may trigger or inhibit seizures. But the EEG biofeedback only is used to decrease abnormal neuronal activity.

  7. Chaotic annealing with hypothesis test for function optimization in noisy environments

    International Nuclear Information System (INIS)

    Pan Hui; Wang Ling; Liu Bo

    2008-01-01

    As a special mechanism to avoid being trapped in local minimum, the ergodicity property of chaos has been used as a novel searching technique for optimization problems, but there is no research work on chaos for optimization in noisy environments. In this paper, the performance of chaotic annealing (CA) for uncertain function optimization is investigated, and a new hybrid approach (namely CAHT) that combines CA and hypothesis test (HT) is proposed. In CAHT, the merits of CA are applied for well exploration and exploitation in searching space, and solution quality can be identified reliably by hypothesis test to reduce the repeated search to some extent and to reasonably estimate performance for solution. Simulation results and comparisons show that, chaos is helpful to improve the performance of SA for uncertain function optimization, and CAHT can further improve the searching efficiency, quality and robustness

  8. Decoding vigilance with NIRS.

    Science.gov (United States)

    Bogler, Carsten; Mehnert, Jan; Steinbrink, Jens; Haynes, John-Dylan

    2014-01-01

    Sustained, long-term cognitive workload is associated with variations and decrements in performance. Such fluctuations in vigilance can be a risk factor especially during dangerous attention demanding activities. Functional MRI studies have shown that attentional performance is correlated with BOLD-signals, especially in parietal and prefrontal cortical regions. An interesting question is whether these BOLD-signals could be measured in real-world scenarios, say to warn in a dangerous workplace whenever a subjects' vigilance is low. Because fMRI lacks the mobility needed for such applications, we tested whether the monitoring of vigilance might be possible using Near-Infrared Spectroscopy (NIRS). NIRS is a highly mobile technique that measures hemodynamics in the surface of the brain. We demonstrate that non-invasive NIRS signals correlate with vigilance. These signals carry enough information to decode subjects' reaction times at a single trial level.

  9. Decoding vigilance with NIRS.

    Directory of Open Access Journals (Sweden)

    Carsten Bogler

    Full Text Available Sustained, long-term cognitive workload is associated with variations and decrements in performance. Such fluctuations in vigilance can be a risk factor especially during dangerous attention demanding activities. Functional MRI studies have shown that attentional performance is correlated with BOLD-signals, especially in parietal and prefrontal cortical regions. An interesting question is whether these BOLD-signals could be measured in real-world scenarios, say to warn in a dangerous workplace whenever a subjects' vigilance is low. Because fMRI lacks the mobility needed for such applications, we tested whether the monitoring of vigilance might be possible using Near-Infrared Spectroscopy (NIRS. NIRS is a highly mobile technique that measures hemodynamics in the surface of the brain. We demonstrate that non-invasive NIRS signals correlate with vigilance. These signals carry enough information to decode subjects' reaction times at a single trial level.

  10. A hypothesis on improving foreign accents by optimizing variability in vocal learning brain circuits

    OpenAIRE

    Simmonds, Anna J.

    2015-01-01

    Rapid vocal motor learning is observed when acquiring a language in early childhood, or learning to speak another language later in life. Accurate pronunciation is one of the hardest things for late learners to master and they are almost always left with a non-native accent. Here, I propose a novel hypothesis that this accent could be improved by optimizing variability in vocal learning brain circuits during learning. Much of the neurobiology of human vocal motor learning has been inferred fr...

  11. A test of the herbivore optimization hypothesis using muskoxen and a graminoid meadow plant community

    Directory of Open Access Journals (Sweden)

    David L. Smith

    1996-01-01

    Full Text Available A prediction from the herbivore optimization hypothesis is that grazing by herbivores at moderate intensities will increase net above-ground primary productivity more than at lower or higher intensities. I tested this hypothesis in an area of high muskox {Ovibos moschatus density on north-central Banks Island, Northwest Territories, Canada (73°50'N, 119°53'W. Plots (1 m2 in graminoid meadows dominated by cottongrass (Eriophorum triste were either clipped, exposed to muskoxen, protected for part of one growing season, or permanently protected. This resulted in the removal of 22-44%, 10-39%, 0-39% or 0%, respectively, of shoot tissue during each growing season. Contrary to the predictions of the herbivore optimization hypothesis, productivity did not increase across this range of tissue removal. Productivity of plants clipped at 1.5 cm above ground once or twice per growing season, declined by 60+/-5% in 64% of the tests. The productivity of plants grazed by muskoxen declined by 56+/-7% in 25% of the tests. No significant change in productivity was observed in 36% and 75% of the tests in clipped and grazed treatments, respecrively. Clipping and grazing reduced below-ground standing crop except where removals were small. Grazing and clipping did not stimulate productivity of north-central Banks Island graminoid meadows.

  12. Coordination and synchronisation of anti-predation vigilance in two crane species.

    Science.gov (United States)

    Ge, Chen; Beauchamp, Guy; Li, Zhongqiu

    2011-01-01

    Much of the previous research on anti-predation vigilance in groups has assumed independent scanning for threats among group members. Alternative patterns that are based on monitoring the vigilance levels of companions can also be adaptive. Coordination of vigilance, in which foragers avoid scanning at the same time as others, should decrease the odds that no group member is alert. Synchronisation of vigilance implies that individuals are more likely to be vigilant when companions are already vigilant. While synchronisation will increase the odds that no one is vigilant, it may allow a better assessment of potential threats. We investigated temporal sequences of vigilance in family flocks consisting of two parents and at most two juveniles in two species of cranes in coastal China. We established whether the observed probability that at least one parent is alert was greater (coordination) or lower (synchronisation) than that predicted under the null hypothesis of independent vigilance. We documented coordination of vigilance in common cranes (Grus grus) foraging in an area with high potential for disturbance by people. We documented synchronisation of vigilance in red-crowned cranes (Grus japonensis) in the less but not in the more disturbed area. Coordination in small flocks leads to high collective vigilance but low foraging rates that may not be suitable in areas with low disturbance. We also argue that synchronisation should break down in areas with high disturbance because periods with low vigilance are riskier. Results highlight the view that temporal patterns of vigilance can take many forms depending on ecological factors.

  13. 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

  14. A hypothesis on improving foreign accents by optimizing variability in vocal learning brain circuits.

    Science.gov (United States)

    Simmonds, Anna J

    2015-01-01

    Rapid vocal motor learning is observed when acquiring a language in early childhood, or learning to speak another language later in life. Accurate pronunciation is one of the hardest things for late learners to master and they are almost always left with a non-native accent. Here, I propose a novel hypothesis that this accent could be improved by optimizing variability in vocal learning brain circuits during learning. Much of the neurobiology of human vocal motor learning has been inferred from studies on songbirds. Jarvis (2004) proposed the hypothesis that as in songbirds there are two pathways in humans: one for learning speech (the striatal vocal learning pathway), and one for production of previously learnt speech (the motor pathway). Learning new motor sequences necessary for accurate non-native pronunciation is challenging and I argue that in late learners of a foreign language the vocal learning pathway becomes inactive prematurely. The motor pathway is engaged once again and learners maintain their original native motor patterns for producing speech, resulting in speaking with a foreign accent. Further, I argue that variability in neural activity within vocal motor circuitry generates vocal variability that supports accurate non-native pronunciation. Recent theoretical and experimental work on motor learning suggests that variability in the motor movement is necessary for the development of expertise. I propose that there is little trial-by-trial variability when using the motor pathway. When using the vocal learning pathway variability gradually increases, reflecting an exploratory phase in which learners try out different ways of pronouncing words, before decreasing and stabilizing once the "best" performance has been identified. The hypothesis proposed here could be tested using behavioral interventions that optimize variability and engage the vocal learning pathway for longer, with the prediction that this would allow learners to develop new motor

  15. Derek Vigil-Fowler | NREL

    Science.gov (United States)

    study, Physical Review B (2014) Physical Origin of Satellites in Photoemission of Doped Graphene: An Ab Initio GW Plus Cumulant Study, Physical Review Letters (2013) Vigil-Fowler Derek Vigil-Fowler Research Scientist: High Performance Computing Derek.Vigil-Fowler

  16. Hypothesis-driven methods to augment human cognition by optimizing cortical oscillations

    Directory of Open Access Journals (Sweden)

    Jörn M. Horschig

    2014-06-01

    Full Text Available Cortical oscillations have been shown to represent fundamental functions of a working brain, e.g. communication, stimulus binding, error monitoring, and inhibition, and are directly linked to behavior. Recent studies intervening with these oscillations have demonstrated effective modulation of both the oscillations and behavior. In this review, we collect evidence in favor of how hypothesis-driven methods can be used to augment cognition by optimizing cortical oscillations. We elaborate their potential usefulness for three target groups: healthy elderly, patients with attention deficit/hyperactivity disorder, and healthy young adults. We discuss the relevance of neuronal oscillations in each group and show how each of them can benefit from the manipulation of functionally-related oscillations. Further, we describe methods for manipulation of neuronal oscillations including direct brain stimulation as well as indirect task alterations. We also discuss practical considerations about the proposed techniques. In conclusion, we propose that insights from neuroscience should guide techniques to augment human cognition, which in turn can provide a better understanding of how the human brain works.

  17. Between-gender differences in vigilance do not necessarily lead to differences in foraging-vigilance tradeoffs.

    Science.gov (United States)

    Barnier, Florian; Duncan, Patrick; Fritz, Hervé; Blanchard, Pierrick; Rubenstein, Daniel I; Pays, Olivier

    2016-07-01

    When prey are time limited in their access to food, any trade-off involving time should ultimately affect their intake rate. In many herbivores, males and females experience different ecological pressures affecting their survival and reproduction because of differences in morphology, physiology and energy/nutrient requirements. If males and females have different vigilance strategies that affect their intake rates differently, they will suffer different foraging costs. This is particularly relevant in sexually monomorphic herbivores, where the two sexes have similar basal energy/nutrient requirements and risk of predation. We investigated how gender, reproductive status, age, group size, predation risk, and food biomass affected vigilance, intake rate, and their trade-off in a monomorphic species, the plains zebra (Equus quagga). Males were more vigilant than females, and lactating females were less vigilant than other females; the levels of vigilance were low (ca. 10 % of feeding time). The effects on time spent feeding, bite rates and intake rates were small and statistically not significant. Reproductive status did not affect the strength of the relationship between vigilance and intake rate, but intake rates increased with group size and, for adult females, were higher in tall grass. While gender and reproductive status were major drivers of vigilance, and group size and food biomass of the rate of food intake, males and females adjust their bite rates and food intake with vigilance in similar ways. Our results support the hypothesis that in monomorphic animals, males and females seem to make similar trade-offs (i.e. adjustments) between vigilance and intake rate.

  18. Coordination and synchronisation of anti-predation vigilance in two crane species.

    Directory of Open Access Journals (Sweden)

    Chen Ge

    Full Text Available Much of the previous research on anti-predation vigilance in groups has assumed independent scanning for threats among group members. Alternative patterns that are based on monitoring the vigilance levels of companions can also be adaptive. Coordination of vigilance, in which foragers avoid scanning at the same time as others, should decrease the odds that no group member is alert. Synchronisation of vigilance implies that individuals are more likely to be vigilant when companions are already vigilant. While synchronisation will increase the odds that no one is vigilant, it may allow a better assessment of potential threats. We investigated temporal sequences of vigilance in family flocks consisting of two parents and at most two juveniles in two species of cranes in coastal China. We established whether the observed probability that at least one parent is alert was greater (coordination or lower (synchronisation than that predicted under the null hypothesis of independent vigilance. We documented coordination of vigilance in common cranes (Grus grus foraging in an area with high potential for disturbance by people. We documented synchronisation of vigilance in red-crowned cranes (Grus japonensis in the less but not in the more disturbed area. Coordination in small flocks leads to high collective vigilance but low foraging rates that may not be suitable in areas with low disturbance. We also argue that synchronisation should break down in areas with high disturbance because periods with low vigilance are riskier. Results highlight the view that temporal patterns of vigilance can take many forms depending on ecological factors.

  19. Active SAmpling Protocol (ASAP) to Optimize Individual Neurocognitive Hypothesis Testing: A BCI-Inspired Dynamic Experimental Design.

    Science.gov (United States)

    Sanchez, Gaëtan; Lecaignard, Françoise; Otman, Anatole; Maby, Emmanuel; Mattout, Jérémie

    2016-01-01

    The relatively young field of Brain-Computer Interfaces has promoted the use of electrophysiology and neuroimaging in real-time. In the meantime, cognitive neuroscience studies, which make extensive use of functional exploration techniques, have evolved toward model-based experiments and fine hypothesis testing protocols. Although these two developments are mostly unrelated, we argue that, brought together, they may trigger an important shift in the way experimental paradigms are being designed, which should prove fruitful to both endeavors. This change simply consists in using real-time neuroimaging in order to optimize advanced neurocognitive hypothesis testing. We refer to this new approach as the instantiation of an Active SAmpling Protocol (ASAP). As opposed to classical (static) experimental protocols, ASAP implements online model comparison, enabling the optimization of design parameters (e.g., stimuli) during the course of data acquisition. This follows the well-known principle of sequential hypothesis testing. What is radically new, however, is our ability to perform online processing of the huge amount of complex data that brain imaging techniques provide. This is all the more relevant at a time when physiological and psychological processes are beginning to be approached using more realistic, generative models which may be difficult to tease apart empirically. Based upon Bayesian inference, ASAP proposes a generic and principled way to optimize experimental design adaptively. In this perspective paper, we summarize the main steps in ASAP. Using synthetic data we illustrate its superiority in selecting the right perceptual model compared to a classical design. Finally, we briefly discuss its future potential for basic and clinical neuroscience as well as some remaining challenges.

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

    NARCIS (Netherlands)

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

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

  1. The Bio-Inspired Optimization of Trading Strategies and Its Impact on the Efficient Market Hypothesis and Sustainable Development Strategies

    Directory of Open Access Journals (Sweden)

    Rafał Dreżewski

    2018-05-01

    Full Text Available In this paper, the evolutionary algorithm for the optimization of Forex market trading strategies is proposed. The introduction to issues related to the financial markets and the evolutionary algorithms precedes the main part of the paper, in which the proposed trading system is presented. The system uses the evolutionary algorithm for optimization of a parameterized greedy strategy, which is then used as an investment strategy on the Forex market. In the proposed system, a model of the Forex market was developed, including all elements that are necessary for simulating realistic trading processes. The proposed evolutionary algorithm contains several novel mechanisms that were introduced to optimize the greedy strategy. The most important of the proposed techniques are the mechanisms for maintaining the population diversity, a mechanism for protecting the best individuals in the population, the mechanisms preventing the excessive growth of the population, the mechanisms of the initialization of the population after moving the time window and a mechanism of choosing the best strategies used for trading. The experiments, conducted with the use of real-world Forex market data, were aimed at testing the quality of the results obtained using the proposed algorithm and comparing them with the results obtained by the buy-and-hold strategy. By comparing our results with the results of the buy-and-hold strategy, we attempted to verify the validity of the efficient market hypothesis. The credibility of the hypothesis would have more general implications for many different areas of our lives, including future sustainable development policies.

  2. Vigilance

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2011-01-01

    This article analyses the relationship between conflict, social invisibility and negative potentiality. Taking its empirical point of departure in fieldwork conducted in Belfast, Northern Ireland, and Bissau, Guinea-Bissau, it illuminates the manner in which people orientate themselves toward pre...

  3. A new semantic vigilance task: vigilance decrement, workload, and sensitivity to dual-task costs.

    Science.gov (United States)

    Epling, Samantha L; Russell, Paul N; Helton, William S

    2016-01-01

    Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

  4. Mental and physical effort affect vigilance differently

    NARCIS (Netherlands)

    Smit, A.S.; Eling, P.A.T.M.; Hopman, M.T.E.; Coenen, A.M.L.

    2005-01-01

    Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants

  5. Mental and physical effort affect vigilance differently.

    NARCIS (Netherlands)

    Smit, A.S.; Eling, P.A.T.M.; Hopman, M.T.E.; Coenen, A.M.L.

    2005-01-01

    Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants

  6. Individual diet variation in a marine fish assemblage: Optimal Foraging Theory, Niche Variation Hypothesis and functional identity

    Science.gov (United States)

    Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S.

    2017-02-01

    Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to

  7. Use of EEG workload indices for diagnostic monitoring of vigilance decrement.

    Science.gov (United States)

    Kamzanova, Altyngul T; Kustubayeva, Almira M; Matthews, Gerald

    2014-09-01

    A study was run to test which of five electroencephalographic (EEG) indices was most diagnostic of loss of vigilance at two levels of workload. EEG indices of alertness include conventional spectral power measures as well as indices combining measures from multiple frequency bands, such as the Task Load Index (TLI) and the Engagement Index (El). However, it is unclear which indices are optimal for early detection of loss of vigilance. Ninety-two participants were assigned to one of two experimental conditions, cued (lower workload) and uncued (higher workload), and then performed a 40-min visual vigilance task. Performance on this task is believed to be limited by attentional resource availability. EEG was recorded continuously. Performance, subjective state, and workload were also assessed. The task showed a vigilance decrement in performance; cuing improved performance and reduced subjective workload. Lower-frequency alpha (8 to 10.9 Hz) and TLI were most sensitive to the task parameters. The magnitude of temporal change was larger for lower-frequency alpha. Surprisingly, higher TLI was associated with superior performance. Frontal theta and El were influenced by task workload only in the final period of work. Correlational data also suggested that the indices are distinct from one another. Lower-frequency alpha appears to be the optimal index for monitoring vigilance on the task used here, but further work is needed to test how diagnosticity of EEG indices varies with task demands. Lower-frequency alpha may be used to diagnose loss of operator alertness on tasks requiring vigilance.

  8. Chewing gum moderates the vigilance decrement.

    OpenAIRE

    Morgan, K.; Johnson, A.J.; Miles, C..

    2014-01-01

    We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in p...

  9. Intrasexual vigilance: the implicit cognition of romantic rivalry.

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    Maner, Jon K; Miller, Saul L; Rouby, D Aaron; Gailliot, Matthew T

    2009-07-01

    Four experiments tested the hypothesis that concerns about infidelity would lead people, particularly those displaying high chronic levels of romantic jealousy, to display a functionally coordinated set of implicit cognitive biases aimed at vigilantly processing attractive romantic rivals. Priming concerns about infidelity led people with high levels of chronic jealousy (but not those low in chronic jealousy) to attend vigilantly to physically attractive same-sex targets at an early stage of visual processing (Study 1), to strongly encode and remember attractive same-sex targets (Study 2), and to form implicit negative evaluations of attractive same-sex targets (Studies 3 and 4). In each case, effects were observed only for same-sex targets who were physically attractive-individuals who can pose especially potent threats to a person's own romantic interests. These studies reveal a cascade of implicit, lower order cognitive processes underlying romantic rivalry and identify the individuals most likely to display those processes. At a broader conceptual level, this research illustrates the utility of integrating social cognitive and evolutionary approaches to psychological science. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  10. Limited Cognitive Resources Explain a Trade-Off between Perceptual and Metacognitive Vigilance.

    Science.gov (United States)

    Maniscalco, Brian; McCurdy, Li Yan; Odegaard, Brian; Lau, Hakwan

    2017-02-01

    Why do experimenters give subjects short breaks in long behavioral experiments? Whereas previous studies suggest it is difficult to maintain attention and vigilance over long periods of time, it is unclear precisely what mechanisms benefit from rest after short experimental blocks. Here, we evaluate decline in both perceptual performance and metacognitive sensitivity (i.e., how well confidence ratings track perceptual decision accuracy) over time and investigate whether characteristics of prefrontal cortical areas correlate with these measures. Whereas a single-process signal detection model predicts that these two forms of fatigue should be strongly positively correlated, a dual-process model predicts that rates of decline may dissociate. Here, we show that these measures consistently exhibited negative or near-zero correlations, as if engaged in a trade-off relationship, suggesting that different mechanisms contribute to perceptual and metacognitive decisions. Despite this dissociation, the two mechanisms likely depend on common resources, which could explain their trade-off relationship. Based on structural MRI brain images of individual human subjects, we assessed gray matter volume in the frontal polar area, a region that has been linked to visual metacognition. Variability of frontal polar volume correlated with individual differences in behavior, indicating the region may play a role in supplying common resources for both perceptual and metacognitive vigilance. Additional experiments revealed that reduced metacognitive demand led to superior perceptual vigilance, providing further support for this hypothesis. Overall, results indicate that during breaks between short blocks, it is the higher-level perceptual decision mechanisms, rather than lower-level sensory machinery, that benefit most from rest. Perceptual task performance declines over time (the so-called vigilance decrement), but the relationship between vigilance in perception and metacognition has

  11. Mood and Vigilance Following Quercetin Supplementation

    National Research Council Canada - National Science Library

    Olson, Craig

    2002-01-01

    .... Based on group assignment, each subject received a one-time dose of 200 mg caffeine plus 1,800 mg placebo, 2,000 mg quercetin or 2,000 mg placebo 1 hour prior to completing a 45-minute scanning visual vigilance task...

  12. SOCIAL VIGILANCE OF SCHOOL JOURNALISTS: COGNITIVE ASPECT

    Directory of Open Access Journals (Sweden)

    Tatyana Vladimirovna Sidorova

    2013-11-01

    Full Text Available In the article one of the stages and results of an ascertaining experiment aimed at identification of the level of high school students’ social vigilance formation are described. The scientific novelty of this work is to implement the pedagogical interpretation of the concept "social vigilance", and also in the selection and creation of valid methods for studying the phenomenon. Ascertaining experiment on cognitive criteria included a test on facts of social reality knowledge, the methods developed by the author "The analysis of the communicative situation," and “Continue the report”, content analysis of texts. The results show that teenagers’ social vigilance largely developed in respect of the microprocesses, but it’s low in respect of macroprocesses. The young journalists have little knowledge about the various social groups, social stratum. The obtained data show the directions of teaching activities to develop students’ social vigilance. Experimental results, methods and forms of research can be extrapolated to other types of educational activities.DOI: http://dx.doi.org/10.12731/2218-7405-2013-7-49

  13. Sensory Modality, Temperament, and the Development of Sustained Attention: A Vigilance Study in Children and Adults

    Science.gov (United States)

    Curtindale, Lori; Laurie-Rose, Cynthia; Bennett-Murphy, Laura; Hull, Sarah

    2007-01-01

    Applying optimal stimulation theory, the present study explored the development of sustained attention as a dynamic process. It examined the interaction of modality and temperament over time in children and adults. Second-grade children and college-aged adults performed auditory and visual vigilance tasks. Using the Carey temperament…

  14. Serotonergic systems associated with arousal and vigilance behaviors following administration of anxiogenic drugs

    DEFF Research Database (Denmark)

    Abrams, J K; Johnson, P L; Hay-Schmidt, Anders

    2005-01-01

    Serotonergic systems play important roles in modulating behavioral arousal, including behavioral arousal and vigilance associated with anxiety states. To further our understanding of the neural systems associated with increases in anxiety states, we investigated the effects of multiple anxiogenic...... and vigilance behaviors consistent with an increase in anxiety state. In addition, these anxiogenic drugs, excluding yohimbine, had convergent actions on an anatomically-defined subset of serotonergic neurons within the middle and caudal, dorsal subdivision of the DR. High resolution topographical analysis...... nucleus, a forebrain structure important for emotional appraisal and modulation of anxiety-related physiological and behavioral responses. Together these findings support the hypothesis that there is a functional topographical organization in the DR and are consistent with the hypothesis that anxiogenic...

  15. Saudi Vigilance Program: Challenges and lessons learned.

    Science.gov (United States)

    Alharf, Adel; Alqahtani, Nasser; Saeed, Ghazi; Alshahrani, Ali; Alshahrani, Mubarak; Aljasser, Nasser; Alquwaizani, Mohammed; Bawazir, Saleh

    2018-03-01

    Pharmacovigilance is vital to public health. Adopting a robust spontaneous reporting system for adverse drug events can counteract most hazards that arise from utilizing medicinal products. Prior to the establishment of the Saudi Food and Drug Authority (SFDA), the number of pharmacovigilance-related activities in Saudi Arabia was limited. In 2009, the SFDA established the National Pharmacovigilance and Drug Safety Center (Saudi Vigilance). The pharmacovigilance system has remarkably improved during the past few years. Several initiatives have been taken to improve the program's performance. These initiatives include initiation of pharmacovigilance guidelines, enhancement of communication and reporting tools, training sessions for concerned staff and healthcare providers, and compliance from stakeholders. This review article provides an overview of what the Saudi Vigilance program is, focusing on the scope, mission and vision, hierarchy, operational themes, and overall work processes. Additionally, we will shed light on the challenges we encountered during the early phase and on our future plans.

  16. Eye-Tracking: An Alternative Vigilance Detector

    Science.gov (United States)

    2011-12-01

    shortened version of the Five Factor Model ( FFM ) (Costa & McCrae, 1992). Studies have found that Introversion and Extraversion results from this...to determine if the FFM is a valid tool for determining if subjects will experience the vigilance decrement. This would be a preferable method...Personality Using the responses to the FFM , we discovered two significant correlations involving the extent to which subjects experienced the

  17. Caffeine deprivation affects vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Phillips-Bute, B G

    1998-08-01

    The effects of brief caffeine deprivation on vigilance performance, mood, and symptoms of caffeine withdrawal were studied in habitual coffee drinkers. Thirty male and female coffee drinkers were tested twice at midday (1130 to 1330 hours) after mornings in which they either consumed caffeinated beverages ad lib or abstained. Vigilance performance was tested with a 30-min computerized visual monitoring task. Mood and withdrawal symptom reports were collected by questionnaires. Caffeine deprivation was associated with impaired vigilance performance characterized by a reduction in the percentage of targets detected and an increase in response time, and by subjective reports of decreased vigor and increased fatigue and symptoms characterized by sleepiness, headache, and reduced ability to work. Even short periods of caffeine deprivation, equivalent in length to skipping regular morning coffee, can produce deficits in sustained attention and noticeable unpleasant caffeine-withdrawal symptoms in habitual coffee drinkers. Such symptoms may be a common side-effect of habitual caffeine consumption that contributes to the maintenance of this behavior.

  18. The effects of theta-burst stimulation on vigilance in humans

    Directory of Open Access Journals (Sweden)

    Armand eMensen

    2014-06-01

    Full Text Available Repetitive transcranial magnetic stimulation has become a popular tool to modulate neuronal networks and associated brain functions in both clinical and basic research. Yet few studies have examined the potential effects of cortical stimulation on general levels of vigilance. In this exploratory study, we used theta-burst protocols, both continuous (cTBS and intermittent (iTBS patterns, to examine whether inhibition or excitation of the left dorso-lateral prefrontal cortex (dlPFC was able to induce reliable and acute changes to vigilance measures, compared to the left dorso-lateral associative visual cortex (dlAVC as a control site in line with previous work. Partially sleep restricted participants underwent four separate sessions in a single day, in a between subjects design for TBS stimulation type and within subjects for locaton, each consisting of maintenance of wakefulness test, a sleep latency test, and a psychomotor vigilance task. TBS significantly affected measures of sleep consolidation, namely latency to sleep stage 2 and sleep efficiency, but had no effects on sleep drive or psychomotor vigilance levels for either TBS type or location. Contrary to our initial hypothesis of the dlAVC as a control site, stimulation to this region resulted in the largest differential effects between stimulation types. Moreover, the effect of TBS was found to be consistent throughout the day. These data may provide the basis for further investigation into therapeutic applications of TBS in sleep disorders.

  19. [Research on vigilance detection based on pulse wave].

    Science.gov (United States)

    Cao, Yong; Jiao, Xuejun; Pan, Jinjin; Jiang, Jin; Fu, Jiahao; Xu, Fenggang; Yang, Hanjun

    2017-12-01

    This paper studied the rule for the change of vigilance based on pulse wave. 10 participants were recruited in a 95-minute Mackworth clock test (MCT) experiment. During the experiment, the vigilance of all participants were evaluated by Karolinska sleepiness scale (KSS) and Stanford sleepiness scale (SSS), and behavior data (the reaction time and the accuracy of target) and pulse wave signal of the participants were recorded simultaneously. The result indicated that vigilance of the participants can be divided into 3 classes: the first 30 minutes for high vigilance level, the middle 30 minutes for general vigilance level, and the last 30 minutes for low vigilance level. Besides, time domain features such as amplitude of secondary peak, amplitude of peak and the latency of secondary peak decreased with the decrease of vigilance, while the amplitude of troughs increased. In terms of frequency domain features, the energy of 4 frequency band including 8.600 ~ 9.375 Hz, 11.720 ~ 12.500 Hz, 38.280 ~ 39.060 Hz and 39.060 ~ 39.840 Hz decreased with the decrease of vigilance. Finally, under the recognition model established by the 8 characteristics mentioned above, the average accuracy of three-classification results over the 10 participants was as high as 88.7%. The results of this study confirmed the feasibility of pulse wave in the evaluation of vigilance, and provided a new way for the real-time monitoring of vigilance.

  20. EEG predictors of covert vigilant attention

    Science.gov (United States)

    Martel, Adrien; Dähne, Sven; Blankertz, Benjamin

    2014-06-01

    Objective. The present study addressed the question whether neurophysiological signals exhibit characteristic modulations preceding a miss in a covert vigilant attention task which mimics a natural environment in which critical stimuli may appear in the periphery of the visual field. Approach. Subjective, behavioural and encephalographic (EEG) data of 12 participants performing a modified Mackworth Clock task were obtained and analysed offline. The stimulus consisted of a pointer performing regular ticks in a clockwise sequence across 42 dots arranged in a circle. Participants were requested to covertly attend to the pointer and press a response button as quickly as possible in the event of a jump, a rare and random event. Main results. Significant increases in response latencies and decreases in the detection rates were found as a function of time-on-task, a characteristic effect of sustained attention tasks known as the vigilance decrement. Subjective sleepiness showed a significant increase over the duration of the experiment. Increased activity in the α-frequency range (8-14 Hz) was observed emerging and gradually accumulating 10 s before a missed target. Additionally, a significant gradual attenuation of the P3 event-related component was found to antecede misses by 5 s. Significance. The results corroborate recent findings that behavioural errors are presaged by specific neurophysiological activity and demonstrate that lapses of attention can be predicted in a covert setting up to 10 s in advance reinforcing the prospective use of brain-computer interface (BCI) technology for the detection of waning vigilance in real-world scenarios. Combining these findings with real-time single-trial analysis from BCI may pave the way for cognitive states monitoring systems able to determine the current, and predict the near-future development of the brain's attentional processes.

  1. The role of memory representation in the vigilance decrement

    OpenAIRE

    CAGGIANO, DANIEL M.; PARASURAMAN, RAJA

    2004-01-01

    Working memory load is critically important for the overall level of performance on vigilance tasks. However, its role in a key aspect of vigilance—sensitivity decrement over time—is unclear. We used a dual-task procedure in which either a spatial or a nonspatial working memory task was performed simultaneously with a spatial vigilance task for 20 min. Sensitivity in the vigilance task declined over time when the concurrent task involved spatial working memory. In contrast, there was no sensi...

  2. Chewing gum moderates the vigilance decrement.

    Science.gov (United States)

    Morgan, Kate; Johnson, Andrew J; Miles, Christopher

    2014-05-01

    We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post-task self-rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing-gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing-gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299-301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501-513) that chewing gum negatively impacts short-term memory task performance. © 2013 The British Psychological Society.

  3. Neurobehavioral Effects of Space Radiation on Psychomotor Vigilance Tests

    Science.gov (United States)

    Hienz, Robert; Davis, Catherine; Weed, Michael; Guida, Peter; Gooden, Virginia; Brady, Joseph; Roma, Peter

    Neurobehavioral Effects of Space Radiation on Psychomotor Vigilance Tests INTRODUCTION Risk assessment of the biological consequences of living in the space radiation environment represents one of the highest priority areas of NASA radiation research. Of critical importance is the need for a risk assessment of damage to the central nervous system (CNS) leading to functional cognitive/behavioral changes during long-term space missions, and the development of effective shielding or biological countermeasures to such risks. The present research focuses on the use of an animal model that employs neurobehavioral tests identical or homologous to those currently in use in human models of risk assessment by U.S. agencies such as the Depart-ment of Defense and Federal Aviation and Federal Railroad Administrations for monitoring performance and estimating accident risks associated with such variables as fatigue and/or alcohol or drug abuse. As a first approximation for establishing human risk assessments due to exposure to space radiation, the present work provides animal performance data obtained with the rPVT (rat Psychomotor Vigilance Test), an animal analog of the human PVT that is currently employed for human risk assessments via quantification of sustained attention (e.g., 'vigilance' or 'readiness to perform' tasks). Ground-based studies indicate that radiation can induce neurobehavioral changes in rodents, including impaired performance on motor tasks and deficits in spatial learning and memory. The present study is testing the hypothesis that radiation exposure impairs motor function, performance accuracy, vigilance, motivation, and memory in adult male rats. METHODS The psychomotor vigilance test (PVT) was originally developed as a human cognitive neurobe-havioral assay for tracking the temporally dynamic changes in sustained attention, and has also been used to track changes in circadian rhythm. In humans the test requires responding to a small, bright

  4. Mental effort causes vigilance decrease due to resource depletion

    NARCIS (Netherlands)

    Smit, A.S.; Eling, P.A.T.M.; Coenen, A.M.L.

    2004-01-01

    The resource view on vigilance performance was tested. First, a low demanding task was compared with a similar low demanding task in which stimulus presentation was less monotonous due to added, irrelevant, stimuli. The resource view, maintaining that vigilance is lowered by hard mental work,

  5. Evolutionary stability of vigilance coordination among social foragers

    NARCIS (Netherlands)

    Rodriguez-Girones, M.A.; Vasquez, R.

    2002-01-01

    Coordination can greatly improve the efficiency of anti-predatory vigilance scans by increasing predator detection for a constant proportion of time spent vigilant. However, it has been rarely found in nature and most studies have detected or assumed independent scanning by group members. In this

  6. The role of memory representation in the vigilance decrement.

    Science.gov (United States)

    Caggiano, Daniel M; Parasuraman, Raja

    2004-10-01

    Working memory load is critically important for the overall level of performance on vigilance tasks. However, its role in a key aspect of vigilance-sensitivity decrement over time-is unclear. We used a dual-task procedure in which either a spatial or a nonspatial working memory task was performed simultaneously with a spatial vigilance task for 20 min. Sensitivity in the vigilance task declined over time when the concurrent task involved spatial working memory. In contrast, there was no sensitivity decrement with a nonspatial working memory task. The results provide the first evidence of a specific role for working memory representation in vigilance decrement. The findings are also consistent with a multiple resource theory in which separate resources for memory representation and cognitive control operations are differentially susceptible to depletion over time, depending on the demands of the task at hand.

  7. Noise pollution has limited effects on nocturnal vigilance in peahens

    Directory of Open Access Journals (Sweden)

    Jessica L. Yorzinski

    2016-09-01

    Full Text Available Natural environments are increasingly exposed to high levels of noise pollution. Noise pollution can alter the behavior of animals but we know little about its effects on antipredator behavior. We therefore investigated the impact of noise pollution on vigilance behavior and roost selection in an avian species, peafowl (Pavo cristatus, that inhabits urban environments. Captive peahens were exposed to noise pollution at night and their vigilance levels and roost selections were monitored. The vigilance levels of peahens were unaffected by exposure to noise pollution within trials. Furthermore, the peahens exhibited no preference for roosting farther or closer to noise pollution. Interestingly, predators often avoided the experimental area during nights with noise pollution, which could explain why vigilance rates were higher overall during control compared to noise trials. The results suggest that peahens’ perception of risk is not drastically impacted by noise pollution but longer-term studies will be necessary to assess any chronic effects.

  8. Noise pollution has limited effects on nocturnal vigilance in peahens.

    Science.gov (United States)

    Yorzinski, Jessica L; Hermann, Fredrick S

    2016-01-01

    Natural environments are increasingly exposed to high levels of noise pollution. Noise pollution can alter the behavior of animals but we know little about its effects on antipredator behavior. We therefore investigated the impact of noise pollution on vigilance behavior and roost selection in an avian species, peafowl ( Pavo cristatus ), that inhabits urban environments. Captive peahens were exposed to noise pollution at night and their vigilance levels and roost selections were monitored. The vigilance levels of peahens were unaffected by exposure to noise pollution within trials. Furthermore, the peahens exhibited no preference for roosting farther or closer to noise pollution. Interestingly, predators often avoided the experimental area during nights with noise pollution, which could explain why vigilance rates were higher overall during control compared to noise trials. The results suggest that peahens' perception of risk is not drastically impacted by noise pollution but longer-term studies will be necessary to assess any chronic effects.

  9. Physiological Investigation of Localized Temperature Effects on Vigilance Performance

    Science.gov (United States)

    2014-03-27

    Lazarus & Folkman , 1984). Past research has shown that people who are challenged perform better on tasks than those who are threatened (Tomaka et al...Cues to Enhance Screener Vigilance (Doctoral dissertation, University of Arizona). Lazarus , R. S., & Folkman , S. (1984). Stress, appraisal, and...Jouanin, J. C., Philippe, M., & Guezennec, C. Y . (2005). EEG and ECG changes during simulator operation reflect mental workload and vigilance

  10. Noise pollution has limited effects on nocturnal vigilance in peahens

    OpenAIRE

    Yorzinski, Jessica L.; Hermann, Fredrick S.

    2016-01-01

    Natural environments are increasingly exposed to high levels of noise pollution. Noise pollution can alter the behavior of animals but we know little about its effects on antipredator behavior. We therefore investigated the impact of noise pollution on vigilance behavior and roost selection in an avian species, peafowl (Pavo cristatus), that inhabits urban environments. Captive peahens were exposed to noise pollution at night and their vigilance levels and roost selections were monitored. The...

  11. Vigilant conservatism in evaluating communicated information.

    Directory of Open Access Journals (Sweden)

    Emmanuel Trouche

    Full Text Available In the absence of other information, people put more weight on their own opinion than on the opinion of others: they are conservative. Several proximal mechanisms have been suggested to account for this finding. One of these mechanisms is that people cannot access reasons for other people's opinions, but they can access the reasons for their own opinions-whether they are the actual reasons that led them to hold the opinions (rational access to reasons, or post-hoc constructions (biased access to reasons. In four experiments, participants were asked to provide an opinion, and then faced with another participant's opinion and asked if they wanted to revise their initial opinion. Some questions were manipulated so that the advice participants were receiving was in fact their own opinion, while what they thought was their own opinion was in fact not. In all experiments, the participants were consistently biased towards what they thought was their own opinion, showing that conservativeness cannot be explained by rational access to reasons, which should have favored the advice. One experiment revealed that conservativeness was not decreased under time pressure, suggesting that biased access to reasons is an unlikely explanation for conservativeness. The experiments also suggest that repetition plays a role in advice taking, with repeated opinions being granted more weight than non-fluent opinions. Our results are not consistent with any of the established proximal explanations for conservatism. Instead, we suggest an ultimate explanation-vigilant conservatism-that sees conservatism as adaptive since receivers should be wary of senders' interests, as they rarely perfectly converge with theirs.

  12. Vigilant conservatism in evaluating communicated information.

    Science.gov (United States)

    Trouche, Emmanuel; Johansson, Petter; Hall, Lars; Mercier, Hugo

    2018-01-01

    In the absence of other information, people put more weight on their own opinion than on the opinion of others: they are conservative. Several proximal mechanisms have been suggested to account for this finding. One of these mechanisms is that people cannot access reasons for other people's opinions, but they can access the reasons for their own opinions-whether they are the actual reasons that led them to hold the opinions (rational access to reasons), or post-hoc constructions (biased access to reasons). In four experiments, participants were asked to provide an opinion, and then faced with another participant's opinion and asked if they wanted to revise their initial opinion. Some questions were manipulated so that the advice participants were receiving was in fact their own opinion, while what they thought was their own opinion was in fact not. In all experiments, the participants were consistently biased towards what they thought was their own opinion, showing that conservativeness cannot be explained by rational access to reasons, which should have favored the advice. One experiment revealed that conservativeness was not decreased under time pressure, suggesting that biased access to reasons is an unlikely explanation for conservativeness. The experiments also suggest that repetition plays a role in advice taking, with repeated opinions being granted more weight than non-fluent opinions. Our results are not consistent with any of the established proximal explanations for conservatism. Instead, we suggest an ultimate explanation-vigilant conservatism-that sees conservatism as adaptive since receivers should be wary of senders' interests, as they rarely perfectly converge with theirs.

  13. Morning anaerobic performance is not altered by vigilance impairment.

    Directory of Open Access Journals (Sweden)

    Romain Lericollais

    Full Text Available The aim of this study was to determine the role played by vigilance on the anaerobic performance recorded during a Wingate test performed at the bathyphase (nadir of the circadian rhythmicity. Twenty active male participants performed a 60-s Wingate test at 6 a.m. during 3 test sessions in counter-balanced order the day after either (i a normal reference night, (ii a total sleep deprivation night, or (iii a total sleep deprivation night associated with an extended simulated driving task from 9 p.m. to 5 a.m. During this task, the number of inappropriate line crossings (ILCs was used to control and quantify the effective decrease in the level of vigilance. The main findings show that (i vigilance of each participant was significantly altered (i.e., a drastic and progressive increase in ILCs is shown during the 7.5 hours of driving by the sleep deprivation night associated with an extended driving task; (ii the subjective evaluation of vigilance performed by self-rated scale revealed an increased impairment of the vigilance level between the normal reference night, the total sleep deprivation night and the total sleep deprivation night associated with an extended driving task; and (iii the morning following this last condition, during the Wingate test, the recorded cycling biomechanical parameters (peak power, mean power and fatigue index values, power decrease, and cycling kinetic and kinematic patterns were not significantly different from the two other conditions. Consequently, these results show that anaerobic performances recorded during a Wingate test performed at the bathyphase of the circadian rhythmicity are not altered by a drastic impairment in vigilance. These findings seem to indicate that vigilance is probably not a factor that contributes to circadian variations in anaerobic performance.

  14. Wireless and wearable EEG system for evaluating driver vigilance.

    Science.gov (United States)

    Lin, Chin-Teng; Chuang, Chun-Hsiang; Huang, Chih-Sheng; Tsai, Shu-Fang; Lu, Shao-Wei; Chen, Yen-Hsuan; Ko, Li-Wei

    2014-04-01

    Brain activity associated with attention sustained on the task of safe driving has received considerable attention recently in many neurophysiological studies. Those investigations have also accurately estimated shifts in drivers' levels of arousal, fatigue, and vigilance, as evidenced by variations in their task performance, by evaluating electroencephalographic (EEG) changes. However, monitoring the neurophysiological activities of automobile drivers poses a major measurement challenge when using a laboratory-oriented biosensor technology. This work presents a novel dry EEG sensor based mobile wireless EEG system (referred to herein as Mindo) to monitor in real time a driver's vigilance status in order to link the fluctuation of driving performance with changes in brain activities. The proposed Mindo system incorporates the use of a wireless and wearable EEG device to record EEG signals from hairy regions of the driver conveniently. Additionally, the proposed system can process EEG recordings and translate them into the vigilance level. The study compares the system performance between different regression models. Moreover, the proposed system is implemented using JAVA programming language as a mobile application for online analysis. A case study involving 15 study participants assigned a 90 min sustained-attention driving task in an immersive virtual driving environment demonstrates the reliability of the proposed system. Consistent with previous studies, power spectral analysis results confirm that the EEG activities correlate well with the variations in vigilance. Furthermore, the proposed system demonstrated the feasibility of predicting the driver's vigilance in real time.

  15. Vigilance in the discrimination-stress model for Black Americans.

    Science.gov (United States)

    Himmelstein, Mary S; Young, Danielle M; Sanchez, Diana T; Jackson, James S

    2015-01-01

    Daily events of discrimination are important factors in understanding health disparities. Vigilant coping, or protecting against anticipated discrimination by monitoring and modifying behaviour, is an understudied mechanism that may link discrimination and health outcomes. This study investigates how responding to everyday discrimination with anticipatory vigilance relates to the health of Black men and women. Black adults (N = 221) from the Detroit area completed measures of discrimination, adverse life events, vigilance coping, stress, depressive symptoms and self-reported health. Vigilance coping strategies mediated the relationship between discrimination and stress. Multi-group path analysis revealed that stress in turn was associated with increased depression in men and women. Self-reported health consequences of stress differed between men and women. Vigilance coping mediates the link between discrimination and stress, and stress has consequences for health outcomes resulting from discrimination. More research is needed to understand other underlying contributors to discrimination, stress and poor health outcomes as well as to create potential interventions to ameliorate health outcomes in the face of discrimination-related stress.

  16. Artificial light pollution increases nocturnal vigilance in peahens

    Directory of Open Access Journals (Sweden)

    Jessica L. Yorzinski

    2015-08-01

    Full Text Available Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus. Captive peahens were exposed to either artificial lighting or natural lighting at night. We employed a novel method to record their vigilance behavior by attaching accelerometers to their heads and continuously monitoring their large head movements. We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrates that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences.

  17. Training for vigilance: using predictive power to evaluate feedback effectiveness.

    Science.gov (United States)

    Szalma, James L; Hancock, Peter A; Warm, Joel S; Dember, William N; Parsons, Kelley S

    2006-01-01

    We examined the effects of knowledge of results (KR) on vigilance accuracy and report the first use of positive and negative predictive power (PPP and NPP) to assess vigilance training effectiveness. Training individuals to detect infrequent signals among a plethora of nonsignals is critical to success in many failure-intolerant monitoring technologies. KR has been widely used for vigilance training, but the effect of the schedule of KR presentation on accuracy has been neglected. Previous research on training for vigilance has used signal detection metrics or hits and false alarms. In this study diagnosticity measures were applied to augment traditional analytic methods. We examined the effects of continuous KR and a partial-KR regimen versus a no-KR control on decision diagnosticity. Signal detection theory (SDT) analysis indicated that KR induced conservatism in responding but did not enhance sensitivity. However, KR in both forms equally enhanced PPP while selectively impairing NPP. There is a trade-off in the effectiveness of KR in reducing false alarms and misses. Together, SDT and PPP/NPP measures provide a more complete portrait of performance effects. PPP and NPP together provide another assessment technique for vigilance performance, and as additional diagnostic tools, these measures are potentially useful to the human factors community.

  18. Effects of theobromine and caffeine on mood and vigilance.

    Science.gov (United States)

    Judelson, Daniel A; Preston, Amy G; Miller, Debra L; Muñoz, Colleen X; Kellogg, Mark D; Lieberman, Harris R

    2013-08-01

    Like caffeine, theobromine crosses the blood-brain barrier and binds to adenosine receptors, suggesting it might share caffeine's beneficial effects on mood and vigilance. Therefore, the purpose of this study was to assess the effect of theobromine doses commonly found in foods on mood and vigilance parameters sensitive to caffeine. Caffeine was tested as a positive control. Twenty-four men (age, 23 [3] years) completed 6 double-blind trials during which they consumed experimental beverages, assessed their mood using standardized self-report questionnaires, and completed a 2-hour visual vigilance task. Three experimental doses (100, 200, and 400 mg theobromine) were delivered in a cocoa-based beverage; 3 matched control treatments (0 mg theobromine, 400 mg theobromine, and 100 mg caffeine) were delivered in a non-cocoa beverage. Mean salivary concentrations of theobromine exhibited significant dose-dependent differences (400 mg trials > 200 mg trial > 100 mg trial > 0 mg trials; P affect mood state or vigilance (P > 0.05), but 100-mg caffeine significantly decreased lethargy/fatigue and increased vigor (P = 0.006 and 0.011, respectively). These findings indicate theobromine does not influence mood and vigilance when administered in nutritionally relevant doses, despite sharing many of caffeine's structural characteristics.

  19. Artificial light pollution increases nocturnal vigilance in peahens.

    Science.gov (United States)

    Yorzinski, Jessica L; Chisholm, Sarah; Byerley, Sydney D; Coy, Jeanee R; Aziz, Aisyah; Wolf, Jamie A; Gnerlich, Amanda C

    2015-01-01

    Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). Captive peahens were exposed to either artificial lighting or natural lighting at night. We employed a novel method to record their vigilance behavior by attaching accelerometers to their heads and continuously monitoring their large head movements. We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrates that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences.

  20. Vigilance and reason - The keys to continued credibility

    International Nuclear Information System (INIS)

    Arlotto, G.A.

    1994-01-01

    I have entitle my speech open-quotes Vigilance and Reason-The Keys to Continued Credibilityclose quotes. A partitioning of the words gives insight into my view of where we are, where we may be going, and that we have control of our fate. open-quotes Continuedclose quotes indicates that I believe, at present, the American Society of Mechanical Engineers (ASME) Codes and Standards process has credibility. open-quotes Keysclose quotes connotes that we are at a crossroads and something must be done to stay on track. And open-quotes Vigilance and Reasonclose quotes suggest that we can achieve our goal of continued credibility through exercising vigilance and reason. We cannot rest on our laurels. We must take conscious, positive actions to strengthen the credibility of our products; otherwise we will backslide. It is up to us

  1. Validation of the Japanese Version of the Body Vigilance Scale.

    Science.gov (United States)

    Saigo, Tatsuo; Takebayashi, Yoshitake; Tayama, Jun; Bernick, Peter J; Schmidt, Norman B; Shirabe, Susumu; Sakano, Yuji

    2016-06-01

    The Body Vigilance Scale is a self-report measure of attention to bodily sensations. The measure was translated into Japanese and its reliability, validity, and factor structure were verified. Participants comprised 286 university students (age: 19 ± 1 years). All participants were administered the scale, along with several indices of anxiety (i.e., Anxiety Sensitivity Index, Short Health Anxiety Inventory Illness Likelihood Scale, Social Interaction Anxiety Scale, and Hospital Anxiety and Depression Scale). The Japanese version of the Body Vigilance Scale exhibited a unidimensional factor structure and strong internal consistency. Construct validity was demonstrated by significant correlations with the above measures. Results suggest that the Japanese version of the scale is a reliable, valid tool for measuring body vigilance in Japanese university students. © The Author(s) 2016.

  2. Hypothesis: Low frequency heart rate variability (LF-HRV) is an input for undisclosed yet biological adaptive control, governing the cardiovascular regulations to assure optimal functioning.

    Science.gov (United States)

    Gabbay, Uri; Bobrovsky, Ben Zion

    2012-02-01

    Cardiovascular regulation is considered today as having three levels: autoregulations, neural regulations and hormonal regulations. We hypothesize that the cardiovascular regulation has an additional (fourth) control level which is outer, hierarchical (adaptive) loop where LF-HRV amplitude serves as a reference input which the neural cardiovascular center detects and responses in order to maintain LF-HRV around some prescribed level. Supporting evidences: LF-HRV absence during artificial cardiac pacing may be associated with "pacemaker syndrome" which had not been sufficiently understood regardless of apparently unimpaired cardiovascular performance. The hypothesis may provide an essential basis for understanding several cardiovascular morbidities and insight toward diagnostic measures and treatments (including but not limited to adding variability to the pulse generator of artificial pacemakers to eliminate "pace maker syndrome"). Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. A hypothesis linking sub-optimal seawater pCO2 conditions for cnidarian-Symbiodinium symbioses with the exceedence of the interglacial threshold (>260 ppmv

    Directory of Open Access Journals (Sweden)

    S. A. Wooldridge

    2012-05-01

    Full Text Available Most scleractinian corals and many other cnidarians host intracellular photosynthetic dinoflagellate symbionts ("zooxanthellae". The zooxanthellae contribute to host metabolism and skeletogenesis to such an extent that this symbiosis is well recognised for its contribution in creating the coral reef ecosystem. The stable functioning of cnidarian symbioses is however dependent upon the host's ability to maintain demographic control of its algal partner. In this review, I explain how the modern envelope of seawater conditions found within many coral reef ecosystems (characterised by elevated temperatures, rising pCO2, and enriched nutrient levels are antagonistic toward the dominant host processes that restrict excessive symbiont proliferation. Moreover, I outline a new hypothesis and initial evidence base, which support the suggestion that the additional "excess" zooxanthellae fraction permitted by seawater pCO2 levels beyond 260 ppmv significantly increases the propensity for symbiosis breakdown ("bleaching" in response to temperature and irradiance extremes. The relevance of this biological threshold is discussed in terms of historical reef extinction events, glacial-interglacial climate cycles and the modern decline of coral reef ecosystems.

  4. A hypothesis linking sub-optimal seawater pCO2 conditions for cnidarian-Symbiodinium symbioses with the exceedence of the interglacial threshold (>260 ppmv)

    Science.gov (United States)

    Wooldridge, S. A.

    2012-05-01

    Most scleractinian corals and many other cnidarians host intracellular photosynthetic dinoflagellate symbionts ("zooxanthellae"). The zooxanthellae contribute to host metabolism and skeletogenesis to such an extent that this symbiosis is well recognised for its contribution in creating the coral reef ecosystem. The stable functioning of cnidarian symbioses is however dependent upon the host's ability to maintain demographic control of its algal partner. In this review, I explain how the modern envelope of seawater conditions found within many coral reef ecosystems (characterised by elevated temperatures, rising pCO2, and enriched nutrient levels) are antagonistic toward the dominant host processes that restrict excessive symbiont proliferation. Moreover, I outline a new hypothesis and initial evidence base, which support the suggestion that the additional "excess" zooxanthellae fraction permitted by seawater pCO2 levels beyond 260 ppmv significantly increases the propensity for symbiosis breakdown ("bleaching") in response to temperature and irradiance extremes. The relevance of this biological threshold is discussed in terms of historical reef extinction events, glacial-interglacial climate cycles and the modern decline of coral reef ecosystems.

  5. Teaching Blended Content Analysis and Critically Vigilant Media Consumption

    Science.gov (United States)

    Harris, Christopher S.

    2015-01-01

    The semester-long activity described herein uses an integrated instructional approach to media studies to introduce students to the research method of qualitative content analysis and help them become more critically vigilant media consumers. The goal is to increase students' media literacy by guiding them in the design of an exploratory…

  6. Factors affecting sleep/vigilance behaviour in incubating mallards

    Czech Academy of Sciences Publication Activity Database

    Javůrková, V.; Hořák, D.; Kreisinger, J.; Klvaňa, P.; Albrecht, Tomáš

    2011-01-01

    Roč. 117, č. 4 (2011), s. 345-355 ISSN 0179-1613 R&D Projects: GA AV ČR KJB601110803; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : mallard * vigilance * antipredation behaviour * incubation Subject RIV: EG - Zoology Impact factor: 2.008, year: 2011

  7. The Co-evolution of Honesty and Strategic Vigilance

    Science.gov (United States)

    Heintz, Christophe; Karabegovic, Mia; Molnar, Andras

    2016-01-01

    We hypothesize that when honesty is not motivated by selfish goals, it reveals social preferences that have evolved for convincing strategically vigilant partners that one is a person worth cooperating with. In particular, we explain how the patterns of dishonest behavior observed in recent experiments can be motivated by preferences for social and self-esteem. These preferences have evolved because they are adaptive in an environment where it is advantageous to be selected as a partner by others and where these others are strategically vigilant: they efficiently evaluate the expected benefit of cooperating with specific partners and attend to their intentions. We specify the adaptive value of strategic vigilance and preferences for social and self-esteem. We argue that evolved preferences for social and self-esteem are satisfied by applying mechanisms of strategic vigilance to one's own behavior. We further argue that such cognitive processes obviate the need for the evolution of preferences for fairness and social norm compliance. PMID:27790162

  8. Effects of Methamphetamine on Vigilance and Tracking during Extended Wakefulness.

    Science.gov (United States)

    1993-09-01

    the log likelihood ratio (log(p); Green & Swets, 1966; Macmillan & Creelman , 1990), was also derived from hit and false-alarm probabilities...vigilance task. Canadian Journal of Psychology, 19, 104-110. Macmillan, N.E., & Creelman , C.D. (1990). Response bias: Characteristics of detection

  9. The co-evolution of honesty and strategic vigilance

    Directory of Open Access Journals (Sweden)

    Christophe Heintz

    2016-10-01

    Full Text Available We hypothesize that when honesty is not motivated by selfish goals, it reveals social preferences that have evolved for convincing strategically vigilant partners that one is a person worth cooperating with. In particular, we explain how the patterns of dishonest behavior observed in recent experiments can be motivated by preferences for social and self-esteem. These preferences have evolved because they are adaptive in an environment where it is advantageous to be selected as a partner by others and where these others are strategically vigilant: they efficiently evaluate the expected benefit of cooperating with specific partners and attend to their intentions. We specify the adaptive value of strategic vigilance and preferences for social and self esteem. We argue that evolved preferences for social and self-esteem are satisfied by applying mechanisms of strategic vigilance to one’s own behavior. We further argue that such cognitive processes obviate the need for the evolution of preferences for fairness and social norm compliance.

  10. THE FRACTAL MARKET HYPOTHESIS

    OpenAIRE

    FELICIA RAMONA BIRAU

    2012-01-01

    In this article, the concept of capital market is analysed using Fractal Market Hypothesis which is a modern, complex and unconventional alternative to classical finance methods. Fractal Market Hypothesis is in sharp opposition to Efficient Market Hypothesis and it explores the application of chaos theory and fractal geometry to finance. Fractal Market Hypothesis is based on certain assumption. Thus, it is emphasized that investors did not react immediately to the information they receive and...

  11. Intra-Abdominal Hypertension and Abdominal Compartment Syndrome in Association with Ruptured Abdominal Aortic Aneurysm in the Endovascular Era: Vigilance Remains Critical

    Directory of Open Access Journals (Sweden)

    Matthew C. Bozeman

    2012-01-01

    In this review, we describe published experience with IAH and ACS complicating abdominal vascular catastrophes, experience with ACS complicating endovascular repair of rAAAs, and techniques for management of the abdominal wound. Vigilance and appropriate management of IAH and ACS remains critically important in decreasing morbidity and optimizing survival following catastrophic intra-abdominal vascular events.

  12. Variability: A Pernicious Hypothesis.

    Science.gov (United States)

    Noddings, Nel

    1992-01-01

    The hypothesis of greater male variability in test results is discussed in its historical context, and reasons feminists have objected to the hypothesis are considered. The hypothesis acquires political importance if it is considered that variability results from biological, rather than cultural, differences. (SLD)

  13. THE FRACTAL MARKET HYPOTHESIS

    Directory of Open Access Journals (Sweden)

    FELICIA RAMONA BIRAU

    2012-05-01

    Full Text Available In this article, the concept of capital market is analysed using Fractal Market Hypothesis which is a modern, complex and unconventional alternative to classical finance methods. Fractal Market Hypothesis is in sharp opposition to Efficient Market Hypothesis and it explores the application of chaos theory and fractal geometry to finance. Fractal Market Hypothesis is based on certain assumption. Thus, it is emphasized that investors did not react immediately to the information they receive and of course, the manner in which they interpret that information may be different. Also, Fractal Market Hypothesis refers to the way that liquidity and investment horizons influence the behaviour of financial investors.

  14. The Affect of Varying Arousal Methods Upon Vigilance and Error Detection in an Automated Command and Control Environment

    National Research Council Canada - National Science Library

    Langhals, Brent

    2001-01-01

    .... The study suggests that by continuously applying arousal stimuli, subjects would retain initially high vigilance levels thereby avoiding the vigilance decrement phenomenon and improving error detection...

  15. A novel mechanism for a survival advantage of vigilant individuals in groups

    NARCIS (Netherlands)

    van der Post, Daniel J.; de Weerd, Harmen; Verbrugge, Rineke; Hemelrijk, Charlotte K.

    2013-01-01

    In many animal species, vigilance is crucial for avoiding predation. In groups, however, nonvigilant individuals could benefit from the vigilance of others without any of the associated costs. In an evolutionary sense, such exploitation may be compensated if vigilant individuals have a survival

  16. Mental effort affects vigilance enduringly: after-effects in EEG and behavior

    NARCIS (Netherlands)

    Smit, A.S.; Eling, P.A.T.M.; Coenen, A.M.L.

    2004-01-01

    Vigilance is assumed to decline with sustained task performance. The EEG-effects during performance on mental tasks, however, cannot be ascribed indisputably to vigilance decline per se. During task performance itself, effects of information processing and vigilance decline may be confounded. In

  17. Associations between heat exposure, vigilance, and balance performance in summer tree fruit harvesters.

    Science.gov (United States)

    Spector, June T; Krenz, Jennifer; Calkins, Miriam; Ryan, Dawn; Carmona, Jose; Pan, Mengjie; Zemke, Anna; Sampson, Paul D

    2018-02-01

    We sought to evaluate potential mediators of the relationship between heat exposure and traumatic injuries in outdoor agricultural workers. Linear mixed models were used to estimate associations between maximum work-shift Wet Bulb Globe Temperature (WBGT max ) and post-shift vigilance (reaction time) and postural sway (total path length) in a cross-sectional sample of 46 Washington State tree fruit harvesters in August-September 2015. The mean (SD) WBGT max was 27.4 (3.2)°C in August and 21.2 (2.0)°C in September. The mean pre-work-shift participant urine specific gravity indicated minimal dehydration. Twenty-four percent of participants exhibited possible excessive sleepiness. There was no association between WBGT max and post-shift reaction time or total path length. Heat exposure was not associated with impaired vigilance or balance in this study, in which the overall mean (SD) WBGT max was 25.9 (4.2)°C. However, the study identified opportunities to ensure adequate pre-work-shift hydration and to optimize sleep and work-shift timing in order to reduce occupational injury and heat-related illness risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Physiopathological Hypothesis of Cellulite

    Science.gov (United States)

    de Godoy, José Maria Pereira; de Godoy, Maria de Fátima Guerreiro

    2009-01-01

    A series of questions are asked concerning this condition including as regards to its name, the consensus about the histopathological findings, physiological hypothesis and treatment of the disease. We established a hypothesis for cellulite and confirmed that the clinical response is compatible with this hypothesis. Hence this novel approach brings a modern physiological concept with physiopathologic basis and clinical proof of the hypothesis. We emphasize that the choice of patient, correct diagnosis of cellulite and the technique employed are fundamental to success. PMID:19756187

  19. Life Origination Hydrate Hypothesis (LOH-Hypothesis

    Directory of Open Access Journals (Sweden)

    Victor Ostrovskii

    2012-01-01

    Full Text Available The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis, according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides, DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their “thermodynamic front” guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor.

  20. White-tailed deer vigilance: the influence of social and environmental factors.

    Directory of Open Access Journals (Sweden)

    Marcus A Lashley

    Full Text Available Vigilance behavior may directly affect fitness of prey animals, and understanding factors influencing vigilance may provide important insight into predator-prey interactions. We used 40,540 pictures taken withcamera traps in August 2011 and 2012to evaluate factors influencing individual vigilance behavior of white-tailed deer (Odocoileus virginianus while foraging at baited sites. We used binary logistic regression to determine if individual vigilance was affected by age, sex, and group size. Additionally, we evaluated whether the time of the day,moon phase,and presence of other non-predatorwildlife species impacted individual vigilance. Juveniles were 11% less vigilant at baited sites than adults. Females were 46% more vigilant when fawns were present. Males and females spent more time feeding as group size increased, but with each addition of 1 individual to a group, males increased feeding time by nearly double that of females. Individual vigilance fluctuated with time of day andwith moon phase but generally was least during diurnal and moonlit nocturnal hours, indicating deer have the ability to adjust vigilance behavior to changing predation risk associated with varyinglight intensity.White-tailed deer increased individual vigilance when other non-predator wildlife were present. Our data indicate that differential effects of environmental and social constraints on vigilance behavior between sexes may encourage sexual segregation in white-tailed deer.

  1. Vigilance: A Review of the Literature and Applications to Sentry Duty

    Energy Technology Data Exchange (ETDEWEB)

    See, Judi E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Vigilance, or sustained attention, involves the ability to maintain focus and remain alert for prolonged periods of time. Problems associated with the ability to sustain attention were first identified in real-world combat situations during World War II, and they continue to abound and evolve as new and different types of situations requiring vigilance arise. This paper provides a review of the vigilance literature that describes the primary psychophysical, task, environmental, pharmacological, and individual factors that impact vigilance performance. The paper also describes how seminal findings from vigilance research apply specifically to the task of sentry duty. The strengths and weaknesses of a human sentry and options to integrate human and automated functions for vigilance tasks are discussed. Finally, techniques that may improve vigilance performance for sentry duty tasks are identified.

  2. Hypothesis analysis methods, hypothesis analysis devices, and articles of manufacture

    Science.gov (United States)

    Sanfilippo, Antonio P [Richland, WA; Cowell, Andrew J [Kennewick, WA; Gregory, Michelle L [Richland, WA; Baddeley, Robert L [Richland, WA; Paulson, Patrick R [Pasco, WA; Tratz, Stephen C [Richland, WA; Hohimer, Ryan E [West Richland, WA

    2012-03-20

    Hypothesis analysis methods, hypothesis analysis devices, and articles of manufacture are described according to some aspects. In one aspect, a hypothesis analysis method includes providing a hypothesis, providing an indicator which at least one of supports and refutes the hypothesis, using the indicator, associating evidence with the hypothesis, weighting the association of the evidence with the hypothesis, and using the weighting, providing information regarding the accuracy of the hypothesis.

  3. On the Keyhole Hypothesis

    DEFF Research Database (Denmark)

    Mikkelsen, Kaare B.; Kidmose, Preben; Hansen, Lars Kai

    2017-01-01

    simultaneously recorded scalp EEG. A cross-validation procedure was employed to ensure unbiased estimates. We present several pieces of evidence in support of the keyhole hypothesis: There is a high mutual information between data acquired at scalp electrodes and through the ear-EEG "keyhole," furthermore we......We propose and test the keyhole hypothesis that measurements from low dimensional EEG, such as ear-EEG reflect a broadly distributed set of neural processes. We formulate the keyhole hypothesis in information theoretical terms. The experimental investigation is based on legacy data consisting of 10...

  4. Independent Coactors May Improve Performance and Lower Workload: Viewing Vigilance Under Social Facilitation.

    Science.gov (United States)

    Claypoole, Victoria L; Szalma, James L

    2018-04-01

    The purpose of the present study was to examine the effects of an independent coactor on vigilance task performance. It was hypothesized that the presence of an independent coactor would improve performance in terms of the proportion of false alarms while also increasing perceived workload and stress. Vigilance, or the ability to maintain attention for extended periods, is of great interest to human factors psychologists. Substantial work has focused on improving vigilance task performance, typically through motivational interventions. Of interest to vigilance researchers is the application of social facilitation as a means of enhancing vigilance. Social facilitation seeks to explain how social presence may improve performance. A total of 100 participants completed a 24-min vigil either alone or in the presence of an independent (confederate) coactor. Participants completed measures of perceived workload and stress. The results indicated that performance (i.e., proportion of false alarms) was improved for those who completed the vigil in the presence of an independent coactor. Interestingly, perceived workload was actually lower for those who completed the vigil in the presence of an independent coactor, although perceived stress was not affected by the manipulation. Authors of future research should extend these findings to other forms of social facilitation and examine vigilance task performance in social contexts in order to determine the utility of social presence for improving vigilance. The use of coactors may be an avenue for organizations to consider utilizing to improve performance because of its relative cost-effectiveness and easy implementation.

  5. O trabalho de vigilância nos centros comerciais

    OpenAIRE

    Gadea,Charles; Cruz,Sofia Alexandra

    2013-01-01

    Este artigo visa escrutinar em termos sociológicos a atividade profissional dos vigilantes nos centros comerciais, analisando o tipo de competências profissionais exigidas, a configuração da hierarquia profissional da vigilância e sua articulação com a comunicação cotidiana entre os vigilantes e, por fim, os desafios e dilemas subjacentes ao ato de vigiar. A pesquisa baseia-se metodologicamente em dados obtidos a partir de entrevistas semidiretivas a vigilantes e observação direta dos seus es...

  6. The Qualitative Expectations Hypothesis

    DEFF Research Database (Denmark)

    Frydman, Roman; Johansen, Søren; Rahbek, Anders

    2017-01-01

    We introduce the Qualitative Expectations Hypothesis (QEH) as a new approach to modeling macroeconomic and financial outcomes. Building on John Muth's seminal insight underpinning the Rational Expectations Hypothesis (REH), QEH represents the market's forecasts to be consistent with the predictions...... of an economistís model. However, by assuming that outcomes lie within stochastic intervals, QEH, unlike REH, recognizes the ambiguity faced by an economist and market participants alike. Moreover, QEH leaves the model open to ambiguity by not specifying a mechanism determining specific values that outcomes take...

  7. The Qualitative Expectations Hypothesis

    DEFF Research Database (Denmark)

    Frydman, Roman; Johansen, Søren; Rahbek, Anders

    We introduce the Qualitative Expectations Hypothesis (QEH) as a new approach to modeling macroeconomic and financial outcomes. Building on John Muth's seminal insight underpinning the Rational Expectations Hypothesis (REH), QEH represents the market's forecasts to be consistent with the predictions...... of an economist's model. However, by assuming that outcomes lie within stochastic intervals, QEH, unlike REH, recognizes the ambiguity faced by an economist and market participants alike. Moreover, QEH leaves the model open to ambiguity by not specifying a mechanism determining specific values that outcomes take...

  8. Social class rank, threat vigilance, and hostile reactivity.

    Science.gov (United States)

    Kraus, Michael W; Horberg, E J; Goetz, Jennifer L; Keltner, Dacher

    2011-10-01

    Lower-class individuals, because of their lower rank in society, are theorized to be more vigilant to social threats relative to their high-ranking upper-class counterparts. This class-related vigilance to threat, the authors predicted, would shape the emotional content of social interactions in systematic ways. In Study 1, participants engaged in a teasing interaction with a close friend. Lower-class participants--measured in terms of social class rank in society and within the friendship--more accurately tracked the hostile emotions of their friend. As a result, lower-class individuals experienced more hostile emotion contagion relative to upper-class participants. In Study 2, lower-class participants manipulated to experience lower subjective socioeconomic rank showed more hostile reactivity to ambiguous social scenarios relative to upper-class participants and to lower-class participants experiencing elevated socioeconomic rank. The results suggest that class affects expectations, perception, and experience of hostile emotion, particularly in situations in which lower-class individuals perceive their subordinate rank.

  9. Binaural auditory beats affect vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

    1998-01-01

    When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

  10. EEG correlates of task engagement and mental workload in vigilance, learning, and memory tasks.

    Science.gov (United States)

    Berka, Chris; Levendowski, Daniel J; Lumicao, Michelle N; Yau, Alan; Davis, Gene; Zivkovic, Vladimir T; Olmstead, Richard E; Tremoulet, Patrice D; Craven, Patrick L

    2007-05-01

    The ability to continuously and unobtrusively monitor levels of task engagement and mental workload in an operational environment could be useful in identifying more accurate and efficient methods for humans to interact with technology. This information could also be used to optimize the design of safer, more efficient work environments that increase motivation and productivity. The present study explored the feasibility of monitoring electroencephalo-graphic (EEG) indices of engagement and workload acquired unobtrusively and quantified during performance of cognitive tests. EEG was acquired from 80 healthy participants with a wireless sensor headset (F3-F4,C3-C4,Cz-POz,F3-Cz,Fz-C3,Fz-POz) during tasks including: multi-level forward/backward-digit-span, grid-recall, trails, mental-addition, 20-min 3-Choice Vigilance, and image-learning and memory tests. EEG metrics for engagement and workload were calculated for each 1 -s of EEG. Across participants, engagement but not workload decreased over the 20-min vigilance test. Engagement and workload were significantly increased during the encoding period of verbal and image-learning and memory tests when compared with the recognition/ recall period. Workload but not engagement increased linearly as level of difficulty increased in forward and backward-digit-span, grid-recall, and mental-addition tests. EEG measures correlated with both subjective and objective performance metrics. These data in combination with previous studies suggest that EEG engagement reflects information-gathering, visual processing, and allocation of attention. EEG workload increases with increasing working memory load and during problem solving, integration of information, analytical reasoning, and may be more reflective of executive functions. Inspection of EEG on a second-by-second timescale revealed associations between workload and engagement levels when aligned with specific task events providing preliminary evidence that second

  11. Revisiting the Dutch hypothesis

    NARCIS (Netherlands)

    Postma, Dirkje S.; Weiss, Scott T.; van den Berge, Maarten; Kerstjens, Huib A. M.; Koppelman, Gerard H.

    The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis

  12. The Lehman Sisters Hypothesis

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2014-01-01

    markdownabstract__Abstract__ This article explores the Lehman Sisters Hypothesis. It reviews empirical literature about gender differences in behavioral, experimental, and neuro-economics as well as in other fields of behavioral research. It discusses gender differences along three dimensions of

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

    Directory of Open Access Journals (Sweden)

    Chunlin Li

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

  14. Vigilance on the move: video game-based measurement of sustained attention.

    Science.gov (United States)

    Szalma, J L; Schmidt, T N; Teo, G W L; Hancock, P A

    2014-01-01

    Vigilance represents the capacity to sustain attention to any environmental source of information over prolonged periods on watch. Most stimuli used in vigilance research over the previous six decades have been relatively simple and often purport to represent important aspects of detection and discrimination tasks in real-world settings. Such displays are most frequently composed of single stimulus presentations in discrete trials against a uniform, often uncluttered background. The present experiment establishes a dynamic, first-person perspective vigilance task in motion using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the study of sustained attention. We conclude that the stress of vigilance extends to the new paradigm, but whether the performance decrement emerges depends upon specific task parameters. The development of the task, the issues to be resolved and the pattern of performance, perceived workload and stress associated with performing such dynamic vigilance are reported. The present experiment establishes a dynamic, first-person perspective movement-based vigilance task using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the evaluation of sustained attention in operational environments in which individuals move as they monitor their environment. Issues addressed in task development are described.

  15. Vigilance and Avoidance of Threat in the Eye Movements of Children with Separation Anxiety Disorder

    Science.gov (United States)

    In-Albon, Tina; Kossowsky, Joe; Schneider, Silvia

    2010-01-01

    The "vigilance-avoidance" attention pattern is found in anxious adults, who initially gaze more at threatening pictures than nonanxious adults (vigilance), but subsequently gaze less at them than nonanxious adults (avoidance). The present research, using eye tracking methodology, tested whether anxious children show the same pattern. Children with…

  16. Vigilance or availability of processing resources. A study on cognitive energetics

    NARCIS (Netherlands)

    Smit, A.S.

    2004-01-01

    The experimental focus of this manuscript was on the exploration of vigilance, which was defined as the energetic condition required for cognitive performance. It was concluded that an increase in theta power in the EEG is a sensitive measure of vigilance lowering. An increase in beta2 power is not

  17. Integrated care: an Information Model for Patient Safety and Vigilance Reporting Systems.

    Science.gov (United States)

    Rodrigues, Jean-Marie; Schulz, Stefan; Souvignet, Julien

    2015-01-01

    Quality management information systems for safety as a whole or for specific vigilances share the same information types but are not interoperable. An international initiative tries to develop an integrated information model for patient safety and vigilance reporting to support a global approach of heath care quality.

  18. Determinants of vigilance in a reintroduced population of Père David's deer

    Directory of Open Access Journals (Sweden)

    Wei ZHENG, Guy BEAUCHAMP, Xuelei JIANG, Zhongqiu LI, Qinglong YANG

    2013-04-01

    Full Text Available After being kept in captivity and isolated from natural predators for more than 1,200 years, Père David’s deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential threat. Antipredator vigilance is an important component of survival for many prey animals in their natural habitat. Do deer still adjust vigilance as a function of risk after such a long period of relaxed predation pressure? Here, we examined vigilance levels in Père David’s deer groups as a function of group size, sex and level of human disturbance. The results showed that individual vigilance significantly decreased with group size in all-female groups but not in all-males or mixed-sex groups. In rutting season, males compete with one another and harass females, and we argue that vigilance is partly aimed at threatening males and that such vigilance increases with group size. This explains why overall vigilance did not vary with group size for males in general and for females in mixed-sex groups. Vigilance increased in more disturbed areas but in in male deer only. The results indicate that despite relaxed predation pressure over centuries, Père David’s deer can still adjust antipredator responses as a function of perceived risk. Such information may become useful in the rewilding programme now under way for this species in China [Current Zoology 59 (2: 265–270, 2013].

  19. Bayesian Hypothesis Testing

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Stephen A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sigeti, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-15

    These are a set of slides about Bayesian hypothesis testing, where many hypotheses are tested. The conclusions are the following: The value of the Bayes factor obtained when using the median of the posterior marginal is almost the minimum value of the Bayes factor. The value of τ2 which minimizes the Bayes factor is a reasonable choice for this parameter. This allows a likelihood ratio to be computed with is the least favorable to H0.

  20. The Drift Burst Hypothesis

    OpenAIRE

    Christensen, Kim; Oomen, Roel; Renò, Roberto

    2016-01-01

    The Drift Burst Hypothesis postulates the existence of short-lived locally explosive trends in the price paths of financial assets. The recent US equity and Treasury flash crashes can be viewed as two high profile manifestations of such dynamics, but we argue that drift bursts of varying magnitude are an expected and regular occurrence in financial markets that can arise through established mechanisms such as feedback trading. At a theoretical level, we show how to build drift bursts into the...

  1. Hypothesis in research

    Directory of Open Access Journals (Sweden)

    Eudaldo Enrique Espinoza Freire

    2018-01-01

    Full Text Available It is intended with this work to have a material with the fundamental contents, which enable the university professor to formulate the hypothesis, for the development of an investigation, taking into account the problem to be solved. For its elaboration, the search of information in primary documents was carried out, such as thesis of degree and reports of research results, selected on the basis of its relevance with the analyzed subject, current and reliability, secondary documents, as scientific articles published in journals of recognized prestige, the selection was made with the same terms as in the previous documents. It presents a conceptualization of the updated hypothesis, its characterization and an analysis of the structure of the hypothesis in which the determination of the variables is deepened. The involvement of the university professor in the teaching-research process currently faces some difficulties, which are manifested, among other aspects, in an unstable balance between teaching and research, which leads to a separation between them.

  2. The Price of Eternal Vigilance: Women and Intoxication

    Directory of Open Access Journals (Sweden)

    Michelle McClellan

    2016-04-01

    Full Text Available The Price of Eternal Vigilance: Women and Intoxication by Michelle McClellan. The author argues that the “cultural meaning of intoxication is shaped profoundly by the reality that we seem to only hear about it from women who have given it up.” This is a problem when it obscures the reasons why women seek out alcohol. Resisting the seemingly inevitable trajectory of addiction and recovery narratives, McClellan introduces the concepts of “dry” and “wet” feminism to draw attention to both the cultural expectations women face and the ways that intoxication might serve as a form of resistance. By refusing to see intoxication as a sort of false consciousness from which women must awake, McClellan demonstrates that it reflects female ambivalence about mothering, sexuality, and pleasure itself.

  3. Epidemic spreading in scale-free networks including the effect of individual vigilance

    International Nuclear Information System (INIS)

    Gong Yong-Wang; Song Yu-Rong; Jiang Guo-Ping

    2012-01-01

    In this paper, we study the epidemic spreading in scale-free networks and propose a new susceptible-infected-recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective spreading rate is dynamically adjusted with the time evolution at the vigilance period. Using the mean-field theory, an analytical result is derived. It shows that individual vigilance has no effect on the epidemic threshold. The numerical simulations agree well with the analytical result. Furthermore, we investigate the effect of individual vigilance on the epidemic spreading speed. It is shown that individual vigilance can slow the epidemic spreading speed effectively and delay the arrival of peak epidemic infection. (general)

  4. Antiaging therapy: a prospective hypothesis

    Directory of Open Access Journals (Sweden)

    Shahidi Bonjar MR

    2015-01-01

    Full Text Available Mohammad Rashid Shahidi Bonjar,1 Leyla Shahidi Bonjar2 1School of Dentistry, Kerman University of Medical Sciences, Kerman Iran; 2Department of Pharmacology, College of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran Abstract: This hypothesis proposes a new prospective approach to slow the aging process in older humans. The hypothesis could lead to developing new treatments for age-related illnesses and help humans to live longer. This hypothesis has no previous documentation in scientific media and has no protocol. Scientists have presented evidence that systemic aging is influenced by peculiar molecules in the blood. Researchers at Albert Einstein College of Medicine, New York, and Harvard University in Cambridge discovered elevated titer of aging-related molecules (ARMs in blood, which trigger cascade of aging process in mice; they also indicated that the process can be reduced or even reversed. By inhibiting the production of ARMs, they could reduce age-related cognitive and physical declines. The present hypothesis offers a new approach to translate these findings into medical treatment: extracorporeal adjustment of ARMs would lead to slower rates of aging. A prospective “antiaging blood filtration column” (AABFC is a nanotechnological device that would fulfill the central role in this approach. An AABFC would set a near-youth homeostatic titer of ARMs in the blood. In this regard, the AABFC immobilizes ARMs from the blood while blood passes through the column. The AABFC harbors antibodies against ARMs. ARM antibodies would be conjugated irreversibly to ARMs on contact surfaces of the reaction platforms inside the AABFC till near-youth homeostasis is attained. The treatment is performed with the aid of a blood-circulating pump. Similar to a renal dialysis machine, blood would circulate from the body to the AABFC and from there back to the body in a closed circuit until ARMs were sufficiently depleted from the blood. The

  5. Improved vigilance after sodium oxybate treatment in narcolepsy : a comparison between in-field and in-laboratory measurements

    NARCIS (Netherlands)

    van Schie, M.K.M.; Werth, E.; Lammers, G.J.; Overeem, S.; Baumann, C.R.; Fronczek, R.

    This two-centre observational study of vigilance measurements assessed the feasibility of vigilance measurements on multiple days using the Sustained Attention to Response Task and the Psychomotor Vigilance Test with portable task equipment, and subsequently assessed the effect of sodium oxybate

  6. Effects of Target Probability and Memory Demands on the Vigilance of Adults with and without Mental Retardation.

    Science.gov (United States)

    Tomporowski, Phillip D.; Tinsley, Veronica

    1994-01-01

    The vigilance of young adults with and without mild mental retardation (MR) was compared, with subjects performing two memory demanding, cognitively based tests. The vigilance decrement of MR adults declined more rapidly than did the vigilance of non-MR adults, due to an interaction between target detectability and response bias, and poor target…

  7. Improved vigilance after sodium oxybate treatment in narcolepsy: a comparison between in-field and in-laboratory measurements

    NARCIS (Netherlands)

    Schie, M.K. van; Werth, E.; Lammers, G.J.; Overeem, S.; Baumann, C.R.; Fronczek, R.

    2016-01-01

    This two-centre observational study of vigilance measurements assessed the feasibility of vigilance measurements on multiple days using the Sustained Attention to Response Task and the Psychomotor Vigilance Test with portable task equipment, and subsequently assessed the effect of sodium oxybate

  8. Keep your eyes open: dispositional vigilance moderates the relationship between operational police stress and stress symptoms.

    Science.gov (United States)

    Kubiak, Jeanette; Krick, Annika; Egloff, Boris

    2017-09-01

    Vigilant coping is characterized by a deep processing of threat-related information. In many cases, vigilant coping increases stress symptoms, whereas avoidant coping decreases negative affect. However, vigilance may be beneficial when stress-eliciting situations involve a risk of injury or escalation as is usually the case in police operations. We investigated the roles of vigilance and cognitive avoidance in police operations in a cross-sectional survey. The participants were 137 students (104 men, M age  = 28.54, SD = 8.04) from the Federal University of Applied Administrative Sciences; 76 of them were already police officers (work experience: M = 12.59 years), and 61 were police officer candidates who had completed a 3- to 6-month police internship. Participants completed a paper-and-pencil survey and reported their operational stress, dispositional vigilance and cognitive avoidance in police operations, and stress symptoms. We found that vigilance was negatively associated with stress symptoms and moderated the relationship between operational stress and stress symptoms. Cognitive avoidance, on the other hand, just missed the level of statistical significance in our test of whether it was positively associated with stress symptoms. Our findings demonstrate that vigilance may protect against the negative consequences of stress in police operations.

  9. Driver Vigilance in Automated Vehicles: Hazard Detection Failures Are a Matter of Time.

    Science.gov (United States)

    Greenlee, Eric T; DeLucia, Patricia R; Newton, David C

    2018-03-01

    The primary aim of the current study was to determine whether monitoring the roadway for hazards during automated driving results in a vigilance decrement. Although automated vehicles are relatively novel, the nature of human-automation interaction within them has the classic hallmarks of a vigilance task. Drivers must maintain attention for prolonged periods of time to detect and respond to rare and unpredictable events, for example, roadway hazards that automation may be ill equipped to detect. Given the similarity with traditional vigilance tasks, we predicted that drivers of a simulated automated vehicle would demonstrate a vigilance decrement in hazard detection performance. Participants "drove" a simulated automated vehicle for 40 minutes. During that time, their task was to monitor the roadway for roadway hazards. As predicted, hazard detection rate declined precipitously, and reaction times slowed as the drive progressed. Further, subjective ratings of workload and task-related stress indicated that sustained monitoring is demanding and distressing and it is a challenge to maintain task engagement. Monitoring the roadway for potential hazards during automated driving results in workload, stress, and performance decrements similar to those observed in traditional vigilance tasks. To the degree that vigilance is required of automated vehicle drivers, performance errors and associated safety risks are likely to occur as a function of time on task. Vigilance should be a focal safety concern in the development of vehicle automation.

  10. Habitat-dependent changes in vigilance behaviour of Red-crowned Crane influenced by wildlife tourism.

    Science.gov (United States)

    Li, Donglai; Liu, Yu; Sun, Xinghai; Lloyd, Huw; Zhu, Shuyu; Zhang, Shuyan; Wan, Dongmei; Zhang, Zhengwang

    2017-11-30

    The Endangered Red-crowned Crane (Grus japonensis) is one of the most culturally iconic and sought-after species by wildlife tourists. Here we investigate how the presence of tourists influence the vigilance behaviour of cranes foraging in Suaeda salsa salt marshes and S. salsa/Phragmites australis mosaic habitat in the Yellow River Delta, China. We found that both the frequency and duration of crane vigilance significantly increased in the presence of wildlife tourists. Increased frequency in crane vigilance only occurred in the much taller S. salsa/P. australis mosaic vegetation whereas the duration of vigilance showed no significant difference between the two habitats. Crane vigilance declined with increasing distance from wildlife tourists in the two habitats, with a minimum distance of disturbance triggering a high degree of vigilance by cranes identified at 300 m. The presence of wildlife tourists may represent a form of disturbance to foraging cranes but is habitat dependent. Taller P. australis vegetation serves primarily as a visual obstruction for cranes, causing them to increase the frequency of vigilance behaviour. Our findings have important implications for the conservation of the migratory red-crowned crane population that winters in the Yellow River Delta and can help inform visitor management.

  11. [Dilemma of null hypothesis in ecological hypothesis's experiment test.

    Science.gov (United States)

    Li, Ji

    2016-06-01

    Experimental test is one of the major test methods of ecological hypothesis, though there are many arguments due to null hypothesis. Quinn and Dunham (1983) analyzed the hypothesis deduction model from Platt (1964) and thus stated that there is no null hypothesis in ecology that can be strictly tested by experiments. Fisher's falsificationism and Neyman-Pearson (N-P)'s non-decisivity inhibit statistical null hypothesis from being strictly tested. Moreover, since the null hypothesis H 0 (α=1, β=0) and alternative hypothesis H 1 '(α'=1, β'=0) in ecological progresses are diffe-rent from classic physics, the ecological null hypothesis can neither be strictly tested experimentally. These dilemmas of null hypothesis could be relieved via the reduction of P value, careful selection of null hypothesis, non-centralization of non-null hypothesis, and two-tailed test. However, the statistical null hypothesis significance testing (NHST) should not to be equivalent to the causality logistical test in ecological hypothesis. Hence, the findings and conclusions about methodological studies and experimental tests based on NHST are not always logically reliable.

  12. Human disturbances, habitat characteristics and social environment generate sex-specific responses in vigilance of Mediterranean mouflon.

    Directory of Open Access Journals (Sweden)

    Stéphanie Benoist

    Full Text Available In prey species, vigilance is an important part of the decision making process related to predation risk effects. Therefore, understanding the mechanisms shaping vigilance behavior provides relevant insights on factors influencing individual fitness. We investigated the role of extrinsic and intrinsic factors on vigilance behavior in Mediterranean mouflon (Ovis gmelini musimon×Ovis sp. in a study site spatially and temporally contrasted in human pressures. Both sexes were less vigilant in the wildlife reserve compared to surrounding unprotected areas, except for males during the hunting period. During this period, males tended to be less strictly restricted to the reserve than females what might lead to a pervasive effect of hunting within the protected area, resulting in an increase in male vigilance. It might also be a rutting effect that did not occur in unprotected areas because males vigilance was already maximal in response to human disturbances. In both sexes, yearlings were less vigilant than adults, probably because they traded off vigilance for learning and energy acquisition and/or because they relied on adult experience present in the group. Similarly, non-reproductive females benefited of the vigilance effort provided by reproductive females when belonging to the same group. However, in the absence of reproductive females, non-reproductive females were as vigilant as reproductive females. Increasing group size was only found to reduce vigilance in females (up to 17.5%, not in males. We also showed sex-specific responses to habitat characteristics. Females increased their vigilance when habitat visibility decreased (up to 13.8% whereas males increased their vigilance when feeding on low quality sites, i.e., when concomitant increase in chewing time can be devoted to vigilance with limited costs. Our global approach was able to disentangle the sex-specific sources of variation in mouflon vigilance and stressed the importance of

  13. Vigilance as a caring expression and Leininger's theory of cultural care diversity and universality.

    Science.gov (United States)

    Carr, J M

    1998-01-01

    Vigilance, or the close, protective involvement of families caring for hospitalized relatives, was explored in this study using holistic ethnography. Leininger's theory of cultural care diversity and universality provided direction for the researcher to generate substantive data about the meanings, patterns, and day-to-day experience of vigilance. Five categories of meaning were derived from the data: commitment to care, emotional upheaval, dynamic nexus, transition, and resilience. The research findings expand understanding of vigilance as a caring expression, suggest direction for nursing practice, and contribute to Leininger's theory of cultural care diversity and universality and the development of nursing science.

  14. Habitual coffee consumption enhances attention and vigilance in hemodialysis patients.

    Science.gov (United States)

    Nikić, Petar M; Andrić, Branislav R; Stojimirović, Biljana B; Trbojevic-Stanković, Jasna; Bukumirić, Zoran

    2014-01-01

    Coffee drinking is the main source of caffeine intake among adult population in the western world. It has been reported that low to moderate caffeine intake has beneficial effect on alertness and cognitive functions in healthy subjects. The aim of this study is to evaluate the impact of habitual coffee consumption on cognitive function in hemodialysis patients. In a cross-sectional study, 86 patients from a single-dialysis centre underwent assessment by the Montreal Cognitive Assessment tool and evaluation for symptoms of fatigue, mood, and sleep disorders by well-validated questionnaires. The habitual coffee use and the average daily caffeine intake were estimated by participants' response to a dietary questionnaire. Sixty-seven subjects (78%) consumed black coffee daily, mostly in low to moderate dose. Cognitive impairment was found in three-quarters of tested patients. Normal mental performance was more often in habitual coffee users (25% versus 16%). Regular coffee drinkers achieved higher mean scores on all tested cognitive domains, but a significant positive correlation was found only for items that measure attention and concentration (P = 0.024). Moderate caffeine intake by habitual coffee consumption could have beneficial impact on cognitive function in hemodialysis patients due to selective enhancement of attention and vigilance.

  15. Autonomic hyper-vigilance in post-infective fatigue syndrome.

    Science.gov (United States)

    Kadota, Yumiko; Cooper, Gavin; Burton, Alexander R; Lemon, Jim; Schall, Ulrich; Lloyd, Andrew; Vollmer-Conna, Ute

    2010-09-01

    This study examined whether post-infective fatigue syndrome (PIFS) is associated with a disturbance in bidirectional autonomic signalling resulting in heightened perception of symptoms and sensations from the body in conjunction with autonomic hyper-reactivity to perceived challenges. We studied 23 patients with PIFS and 25 healthy matched control subjects. A heartbeat discrimination task and a pressure pain threshold test were used to assess interoceptive sensitivity. Cardiac response was assessed over a 4-min Stroop task. PIFS was associated with higher accuracy in heartbeat discrimination and a lower pressure pain threshold. Increased interoceptive sensitivity correlated strongly with current symptoms and potentiated differences in the cardiac response to the Stroop task, which in PIFS was characterized by insensitivity to task difficulty and lack of habituation. Our results provide the first evidence of heightened interoceptive sensitivity in PIFS. Together with the distinct pattern in cardiac responsivity these findings present a picture of physiological hyper-vigilance and response inflexibility. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  16. Habitual Coffee Consumption Enhances Attention and Vigilance in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Petar M. Nikić

    2014-01-01

    Full Text Available Objective. Coffee drinking is the main source of caffeine intake among adult population in the western world. It has been reported that low to moderate caffeine intake has beneficial effect on alertness and cognitive functions in healthy subjects. The aim of this study is to evaluate the impact of habitual coffee consumption on cognitive function in hemodialysis patients. Methods. In a cross-sectional study, 86 patients from a single-dialysis centre underwent assessment by the Montreal Cognitive Assessment tool and evaluation for symptoms of fatigue, mood, and sleep disorders by well-validated questionnaires. The habitual coffee use and the average daily caffeine intake were estimated by participants’ response to a dietary questionnaire. Results. Sixty-seven subjects (78% consumed black coffee daily, mostly in low to moderate dose. Cognitive impairment was found in three-quarters of tested patients. Normal mental performance was more often in habitual coffee users (25% versus 16%. Regular coffee drinkers achieved higher mean scores on all tested cognitive domains, but a significant positive correlation was found only for items that measure attention and concentration (P=0.024. Conclusions. Moderate caffeine intake by habitual coffee consumption could have beneficial impact on cognitive function in hemodialysis patients due to selective enhancement of attention and vigilance.

  17. Sturge-Weber syndrome: Continued vigilance is needed.

    Science.gov (United States)

    Hassan, Saeed; Babiker, Amir; Bashiri, Fahad A; Hassan, Hamdi H; Husseini, Maha El; Salih, Mustafa A

    2015-01-01

    Sturge-Weber syndrome (SWS) is a non-hereditary congenital disorder due to somatic mosaic mutations in the GNAQ gene. The classical presentation relates to the brain lesion (cerebral angiomatous lesion of leptomeninges, which is responsible for epileptic seizures, hemiparesis and mental retardation), skin lesion (unilateral facial nevus), ocular and oral involvement. We present a 12-year-old boy who was referred to the Division of Pediatric Neurology, King Saud University Medical City, Riyadh, Saudi Arabia with left-sided hemiparesis. Physical examination showed a port wine stain involving the right side of the face, extending to the upper thorax, and enlargement of both the right eye globe and cornea (megalocornea), indicating the presence of glaucoma. Following urgent referral to ophthalmology service, his eye condition improved dramatically post surgery. Neuroradiological investigations, including cranial computed tomography (CT) and magnetic resonance angiography (MRI) revealed the classical brain lesions of SWS, as well as right leptomeningeal choroidal angioma. Ten months later, he developed focal-onset seizures which responded to treatment. His cognition is normal with good school performance. Continued vigilance is needed to identify and manage the complications of SWS.

  18. The Bergschrund Hypothesis Revisited

    Science.gov (United States)

    Sanders, J. W.; Cuffey, K. M.; MacGregor, K. R.

    2009-12-01

    After Willard Johnson descended into the Lyell Glacier bergschrund nearly 140 years ago, he proposed that the presence of the bergschrund modulated daily air temperature fluctuations and enhanced freeze-thaw processes. He posited that glaciers, through their ability to birth bergschrunds, are thus able to induce rapid cirque headwall retreat. In subsequent years, many researchers challenged the bergschrund hypothesis on grounds that freeze-thaw events did not occur at depth in bergschrunds. We propose a modified version of Johnson’s original hypothesis: that bergschrunds maintain subfreezing temperatures at values that encourage rock fracture via ice lensing because they act as a cold air trap in areas that would otherwise be held near zero by temperate glacial ice. In support of this claim we investigated three sections of the bergschrund at the West Washmawapta Glacier, British Columbia, Canada, which sits in an east-facing cirque. During our bergschrund reconnaissance we installed temperature sensors at multiple elevations, light sensors at depth in 2 of the 3 locations and painted two 1 m2 sections of the headwall. We first emphasize bergschrunds are not wanting for ice: verglas covers significant fractions of the headwall and icicles dangle from the base of bödens or overhanging rocks. If temperature, rather than water availability, is the limiting factor governing ice-lensing rates, our temperature records demonstrate that the bergschrund provides a suitable environment for considerable rock fracture. At the three sites (north, west, and south walls), the average temperature at depth from 9/3/2006 to 8/6/2007 was -3.6, -3.6, and -2.0 °C, respectively. During spring, when we observed vast amounts of snow melt trickle in to the bergschrund, temperatures averaged -3.7, -3.8, and -2.2 °C, respectively. Winter temperatures are even lower: -8.5, -7.3, and -2.4 °C, respectively. Values during the following year were similar. During the fall, diurnal

  19. Anxiety Sensitivity, Body Vigilance, Interoceptive Acuity, and Cardiovascular Reactivity in the Genesis of Panic

    National Research Council Canada - National Science Library

    Storey, Julie

    2000-01-01

    .... The tendency to interpret arousal symptoms as threatening is known as anxiety sensitivity (AS), but it is unclear if increased vigilance, greater physiological reactivity, or enhanced perception are responsible for reported physiological symptoms...

  20. The Neuroergonomics of Vigilance: Effects of Spatial Uncertainty on Cerebral Blood Flow Velocity and Oculomotor Fatigue

    Science.gov (United States)

    2017-02-01

    at work (pp. 95–112). New York, NY: Oxford University Press. Milosevic, S. (1974). Effects of time and space uncertainty on a vigilance task...Parasuraman, R. (2007). Cerebral hemodynamics and vigilance. In R. Parasuraman & M. Rizzo (Eds.), Neuro- ergonomics : The brain at work (pp. 146–158). New...Eric T. Greenlee 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER H0HJ (53290813) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval

  1. Sex-dependent foraging effort and vigilance in coal-crested finches, Charitospiza eucosma (Aves: Emberizidae during the breeding season: evidence of female-biased predation?

    Directory of Open Access Journals (Sweden)

    Pedro Diniz

    2011-04-01

    Full Text Available Sexual dimorphism in birds is often attributed to sexual selection, but another interpretation suggests the evolution of this phenomenon by natural selection. Predation may be an important selective pressure, acting mainly on females. In this study, I tested the latter hypothesis on the coal-crested finch (Charitospiza eucosma Oberholser, 1905 in a neotropical savanna of the Central Brazil (Cerrado. I used capture methods for ascertaining the sex ratio in the population, and focal observations to gather behavioral data. My results show that the sex ratio is skewed toward males (1:1.39. Males were more vigilant, vocalized for longer periods of time, and used higher perches than females. Females foraged more, spent more time on parental care and remained on the ground for longer periods than males. These results support the 'foraging effort hypothesis, suggesting that females are more preyed upon because they spend more time foraging. Ultimately, this may reflect the fact that females invest more on parental care than males. The sex-dependent parental investment may favor the evolution of different antipredator strategies in males and females: the camouflage in females as a less efficient strategy than vigilance in males.

  2. Privacy on Hypothesis Testing in Smart Grids

    OpenAIRE

    Li, Zuxing; Oechtering, Tobias

    2015-01-01

    In this paper, we study the problem of privacy information leakage in a smart grid. The privacy risk is assumed to be caused by an unauthorized binary hypothesis testing of the consumer's behaviour based on the smart meter readings of energy supplies from the energy provider. Another energy supplies are produced by an alternative energy source. A controller equipped with an energy storage device manages the energy inflows to satisfy the energy demand of the consumer. We study the optimal ener...

  3. The weight of racism: Vigilance and racial inequalities in weight-related measures

    Science.gov (United States)

    Hicken, Margaret T.; Lee, Hedwig; Hing, Anna K.

    2017-01-01

    In the United States, racial/ethnic inequalities in obesity are well-documented, particularly among women. Using the Chicago Community Adult Health Study, a probability-based sample in 2001–2003 (N=3,105), we examined the roles of discrimination and vigilance in racial inequalities in two weight-related measures, body mass index (BMI) and waist circumference (WC), viewed through a cultural racism lens. Cultural racism creates a social environment in which Black Americans bear the stigma burden of their racial group while White Americans are allowed to view themselves as individuals. We propose that in this context, interpersonal discrimination holds a different meaning for Blacks and Whites, while vigilance captures the coping style for Blacks who carry the stigma burden of the racial group. By placing discrimination and vigilance within the context of cultural racism, we operationalize existing survey measures and utilize statistical models to clarify the ambiguous associations between discrimination and weight-related inequalities in the extant literature. Multivariate models were estimated for BMI and WC separately and were stratified by gender. Black women had higher mean BMI and WC than any other group, as well as highest levels of vigilance. White women did not show an association between vigilance and WC but did show a strong positive association between discrimination and WC. Conversely, Black women displayed an association between vigilance and WC, but not between discrimination and WC. These results demonstrate that vigilance and discrimination may hold different meanings for obesity by ethnoracial group that are concealed when all women are examined together and viewed without considering a cultural racism lens. PMID:28372829

  4. Viewing the workload of vigilance through the lenses of the NASA-TLX and the MRQ.

    Science.gov (United States)

    Finomore, Victor S; Shaw, Tyler H; Warm, Joel S; Matthews, Gerald; Boles, David B

    2013-12-01

    The aim of this study was to compare the effectiveness of a new index of perceived mental workload, the Multiple Resource Questionnaire (MRQ), with the standard measure of workload used in the study of vigilance, the NASA Task Load Index (NASA-TLX). The NASA-TLX has been used extensively to demonstrate that vigilance tasks impose a high level of workload on observers. However, this instrument does not specify the information-processing resources needed for task performance. The MRQ offers a tool to measure the workload associated with vigilance assignments in which such resources can be identified. Two experiments were performed in which factors known to influence task demand were varied. Included were the detection of stimulus presence or absence, detecting critical signals by means of successive-type (absolute judgment) and simultaneous-type (comparative judgment) discriminations, and operating under multitask vs. single-task conditions. The MRQ paralleled the NASA-TLX in showing that vigilance tasks generally induce high levels of workload and that workload scores are greater in detecting stimulus absence than presence and in making successive as compared to simultaneous-type discriminations. Additionally, the MRQ was more effective than the NASA-TLX in reflecting higher workload in the context of multitask than in single-task conditions. The resource profiles obtained with MRQ fit well with the nature of the vigilance tasks employed, testifying to the scale's content validity. The MRQ may be a meaningful addition to the NASA-TLX for measuring the workload of vigilance assignments. By uncovering knowledge representation associated with different tasks, the MRQ may aid in designing operational vigilance displays.

  5. The 5-choice continuous performance test: evidence for a translational test of vigilance for mice.

    Directory of Open Access Journals (Sweden)

    Jared W Young

    Full Text Available Attentional dysfunction is related to functional disability in patients with neuropsychiatric disorders such as schizophrenia, bipolar disorder, and Alzheimer's disease. Indeed, sustained attention/vigilance is among the leading targets for new medications designed to improve cognition in schizophrenia. Although vigilance is assessed frequently using the continuous performance test (CPT in humans, few tests specifically assess vigilance in rodents.We describe the 5-choice CPT (5C-CPT, an elaboration of the 5-choice serial reaction (5CSR task that includes non-signal trials, thus mimicking task parameters of human CPTs that use signal and non-signal events to assess vigilance. The performances of C57BL/6J and DBA/2J mice were assessed in the 5C-CPT to determine whether this task could differentiate between strains. C57BL/6J mice were also trained in the 5CSR task and a simple reaction-time (RT task involving only one choice (1CRT task. We hypothesized that: 1 C57BL/6J performance would be superior to DBA/2J mice in the 5C-CPT as measured by the sensitivity index measure from signal detection theory; 2 a vigilance decrement would be observed in both strains; and 3 RTs would increase across tasks with increased attentional load (1CRT task<5CSR task<5C-CPT.C57BL/6J mice exhibited superior SI levels compared to DBA/2J mice, but with no difference in accuracy. A vigilance decrement was observed in both strains, which was more pronounced in DBA/2J mice and unaffected by response bias. Finally, we observed increased RTs with increased attentional load, such that 1CRT task<5CSR task<5C-CPT, consistent with human performance in simple RT, choice RT, and CPT tasks. Thus we have demonstrated construct validity for the 5C-CPT as a measure of vigilance that is analogous to human CPT studies.

  6. The weight of racism: Vigilance and racial inequalities in weight-related measures.

    Science.gov (United States)

    Hicken, Margaret T; Lee, Hedwig; Hing, Anna K

    2018-02-01

    In the United States, racial/ethnic inequalities in obesity are well-documented, particularly among women. Using the Chicago Community Adult Health Study, a probability-based sample in 2001-2003 (N = 3105), we examined the roles of discrimination and vigilance in racial inequalities in two weight-related measures, body mass index (BMI) and waist circumference (WC), viewed through a cultural racism lens. Cultural racism creates a social environment in which Black Americans bear the stigma burden of their racial group while White Americans are allowed to view themselves as individuals. We propose that in this context, interpersonal discrimination holds a different meaning for Blacks and Whites, while vigilance captures the coping style for Blacks who carry the stigma burden of the racial group. By placing discrimination and vigilance within the context of cultural racism, we operationalize existing survey measures and utilize statistical models to clarify the ambiguous associations between discrimination and weight-related inequalities in the extant literature. Multivariate models were estimated for BMI and WC separately and were stratified by gender. Black women had higher mean BMI and WC than any other group, as well as highest levels of vigilance. White women did not show an association between vigilance and WC but did show a strong positive association between discrimination and WC. Conversely, Black women displayed an association between vigilance and WC, but not between discrimination and WC. These results demonstrate that vigilance and discrimination may hold different meanings for obesity by ethnoracial group that are concealed when all women are examined together and viewed without considering a cultural racism lens. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Is the Aluminum Hypothesis Dead?

    Science.gov (United States)

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

  8. Effects of signal salience and noise on performance and stress in an abbreviated vigil

    Science.gov (United States)

    Helton, William Stokely

    Vigilance or sustained attention tasks traditionally require observers to detect predetermined signals that occur unpredictably over periods of 30 min to several hours (Warm, 1984). These tasks are taxing and have been useful in revealing the effects of stress agents, such as infectious disease and drugs, on human performance (Alluisi, 1969; Damos & Parker, 1994; Warm, 1993). However, their long duration has been an inconvenience. Recently, Temple and his associates (Temple et al., 2000) developed an abbreviated 12-min vigilance task that duplicates many of the findings with longer duration vigils. The present study was designed to explore further the similarity of the abbreviated task to long-duration vigils by investigating the effects of signal salience and jet-aircraft engine noise on performance, operator stress, and coping strategies. Forty-eight observers (24 males and 24 females) were assigned at random to each of four conditions resulting from the factorial combination of signal salience (high and low contrast signals) and background noise (quiet and jet-aircraft noise). As is the case with long-duration vigils (Warm, 1993), signal detection in the abbreviated task was poorer for low salience than for high salience signals. In addition, stress scores, as indexed by the Dundee Stress State Questionnaire (Matthews, Joiner, Gilliland, Campbell, & Falconer, 1999), were elevated in the low as compared to the high salience condition. Unlike longer vigils, however, (Becker, Warm, Dember, & Hancock, 1996), signal detection in the abbreviated task was superior in the presence of aircraft noise than in quiet. Noise also attenuated the stress of the vigil, a result that is counter to previous findings regarding the effects of noise in a variety of other scenarios (Clark, 1984). Examination of observers' coping responses, as assessed by the Coping Inventory for Task Situations (Matthews & Campbell, 1998), indicated that problem-focused coping was the overwhelming

  9. Development of a method to maintain vigilance level; Kakusei teika keigen shuho no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Y.; Horiguchi, A.; Ishida, K.; Hata, S. [Mazda Motor Corp., Hiroshima (Japan)

    1995-04-20

    As a part of measures to prevent accidents caused by reduced vigilance and drowsiness of drivers, this paper reports the result of experiments that presents effectiveness of a method to give drivers intermittent auditory stimuli as environmental stimulation. It was found that vigilance decline can be reduced by intermittent auditory stimuli under a laboratory condition using a selective reaction time in monotonous selective reaction works as a parameter; and the effective interval in the intermittence is 30 seconds. A driving simulator was used to prove that the vigilance decline reducing effect by the intermittent auditory stimuli has the same level of effect as chewing gums even under the environment composed of driving operation, vehicle motions, and background noise. However, a number of questions remain yet to be discussed, such as the effect when the ratio of sound presentation time and no presentation time was varied. Furthermore, a number of other physical stimuli in addition to auditory stimulation may be assumed that has effective possibility as vigilance decline reducing stimuli, including hot heat and vibration. It was verified, however, that vigilance decline can be reduced by properly varying the environmental stimulation. 6 refs., 15 figs., 1 tab.

  10. ALCOol, vigiLAnce, Charge de travail : facteurs d'accident chez les jeunes conducteurs

    OpenAIRE

    BERTHELON, Catherine; GALY, Edith; PAXION, Julie; Ferrier, Laurent

    2016-01-01

    D'après le modèle de courbe en U renversé d'Ansseau et Timsit-Berthier (1987 ; in Hadj-Mabrouk, 2001), le niveau de performance augmente avec celui de la vigilance jusqu'à un optimum, au-delà de cet optimum l'augmentation de la vigilance entraîne au contraire une baisse de la performance. L'excès de vigilance que représentent la tension (stress) ou l'hyperexcitation a un pouvoir de dégradation plus rapide sur les activités complexes que sur les activités les plus simples. Il y a donc un nivea...

  11. Vigilance impossible: Diligence, distraction, and daydreaming all lead to failures in a practical monitoring task.

    Science.gov (United States)

    Casner, Stephen M; Schooler, Jonathan W

    2015-09-01

    In laboratory studies of vigilance, participants watch for unusual events in a "sit and stare" fashion as their performance typically declines over time. But watch keepers in practical settings seldom approach monitoring in such simplistic ways and controlled environments. We observed airline pilots performing routine monitoring duties in the cockpit. Unlike laboratory studies, pilots' monitoring did not deteriorate amidst prolonged vigils. Monitoring was frequently interrupted by other pop-up tasks and misses followed. However, when free from these distractions, pilots reported copious mind wandering. Pilots often confined their mind wandering to times in which their monitoring performance would not conspicuously suffer. But when no convenient times were available, pilots mind wandered anyway and misses ensued. Real-world monitors may be caught between a continuous vigilance approach that is doomed to fail, a dynamic environment that cannot be fully controlled, and what may be an irresistible urge to let one's thoughts drift. Published by Elsevier Inc.

  12. Reverse hypothesis machine learning a practitioner's perspective

    CERN Document Server

    Kulkarni, Parag

    2017-01-01

    This book introduces a paradigm of reverse hypothesis machines (RHM), focusing on knowledge innovation and machine learning. Knowledge- acquisition -based learning is constrained by large volumes of data and is time consuming. Hence Knowledge innovation based learning is the need of time. Since under-learning results in cognitive inabilities and over-learning compromises freedom, there is need for optimal machine learning. All existing learning techniques rely on mapping input and output and establishing mathematical relationships between them. Though methods change the paradigm remains the same—the forward hypothesis machine paradigm, which tries to minimize uncertainty. The RHM, on the other hand, makes use of uncertainty for creative learning. The approach uses limited data to help identify new and surprising solutions. It focuses on improving learnability, unlike traditional approaches, which focus on accuracy. The book is useful as a reference book for machine learning researchers and professionals as ...

  13. Hypothesis Designs for Three-Hypothesis Test Problems

    OpenAIRE

    Yan Li; Xiaolong Pu

    2010-01-01

    As a helpful guide for applications, the alternative hypotheses of the three-hypothesis test problems are designed under the required error probabilities and average sample number in this paper. The asymptotic formulas and the proposed numerical quadrature formulas are adopted, respectively, to obtain the hypothesis designs and the corresponding sequential test schemes under the Koopman-Darmois distributions. The example of the normal mean test shows that our methods are qu...

  14. Protection from ischemic heart injury by a vigilant heme oxygenase-1 plasmid system.

    Science.gov (United States)

    Tang, Yao Liang; Tang, Yi; Zhang, Y Clare; Qian, Keping; Shen, Leping; Phillips, M Ian

    2004-04-01

    Although human heme oxygenase-1 (hHO-1) could provide a useful approach for cellular protection in the ischemic heart, constitutive overexpression of hHO-1 may lead to unwanted side effects. To avoid this, we designed a hypoxia-regulated hHO-1 gene therapy system that can be switched on and off. This vigilant plasmid system is composed of myosin light chain-2v promoter and a gene switch that is based on an oxygen-dependent degradation domain from the hypoxia inducible factor-1-alpha. The vector can sense ischemia and switch on the hHO-1 gene system, specifically in the heart. In an in vivo experiment, the vigilant hHO-1 plasmid or saline was injected intramyocardially into myocardial infarction mice or sham operation mice. After gene transfer, expression of hHO-1 was only detected in the ischemic heart treated with vigilant hHO-1 plasmids. Masson trichrome staining showed significantly fewer fibrotic areas in vigilant hHO-1 plasmids-treated mice compared with saline control (43.0%+/-4.8% versus 62.5%+/-3.3%, PhHO-1 expression in peri-infarct border areas, concomitant with higher Bcl-2 levels and lower Bax, Bak, and caspase 3 levels in the ischemic myocardium compared with saline control. By use of a cardiac catheter, heart from vigilant hHO-1 plasmids-treated mice showed improved recovery of contractile and diastolic performance after myocardial infarction compared with saline control. This study documents the beneficial regulation and therapeutic potential of vigilant plasmid-mediated hHO-1 gene transfer. This novel gene transfer strategy can provide cardiac-specific protection from future repeated bouts of ischemic injury.

  15. Tests of the lunar hypothesis

    Science.gov (United States)

    Taylor, S. R.

    1984-01-01

    The concept that the Moon was fissioned from the Earth after core separation is the most readily testable hypothesis of lunar origin, since direct comparisons of lunar and terrestrial compositions can be made. Differences found in such comparisons introduce so many ad hoc adjustments to the fission hypothesis that it becomes untestable. Further constraints may be obtained from attempting to date the volatile-refractory element fractionation. The combination of chemical and isotopic problems suggests that the fission hypothesis is no longer viable, and separate terrestrial and lunar accretion from a population of fractionated precursor planetesimals provides a more reasonable explanation.

  16. Benefits of the New Laboratory Methods of the Vigilance of the Health of Cienfuegos Population

    Directory of Open Access Journals (Sweden)

    Pedro Sánchez Frenes

    2015-03-01

    Full Text Available The vigilance of laboratory is the one that is developed on the general population or selected groups by means of the use of tests stop to sieve some health problems. As a part of sanitary strategies of the country, the technologies of the Ultrmicroanalytic System with the aim of strengthen the vigilance of infectious, tumor, congenital disease, among others. Its diagnostic capability has been enlarged and diversified, granting to the work of this system, a new conception, constituting a fortress of the health system in each municipality.

  17. Evaluating the Stage Learning Hypothesis.

    Science.gov (United States)

    Thomas, Hoben

    1980-01-01

    A procedure for evaluating the Genevan stage learning hypothesis is illustrated by analyzing Inhelder, Sinclair, and Bovet's guided learning experiments (in "Learning and the Development of Cognition." Cambridge: Harvard University Press, 1974). (Author/MP)

  18. The Purchasing Power Parity Hypothesis:

    African Journals Online (AJOL)

    2011-10-02

    Oct 2, 2011 ... reject the unit root hypothesis in real exchange rates may simply be due to the shortness ..... Violations of Purchasing Power Parity and Their Implications for Efficient ... Official Intervention in the Foreign Exchange Market:.

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

    Directory of Open Access Journals (Sweden)

    Mu-Yang Wang

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

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Blinks, saccades, and fixation pauses during vigilance task performance. II., Gender and time of day.

    Science.gov (United States)

    1996-03-01

    As operators are required to spend more time monitoring computer controlled devices in future systems, it is critical to define the task and situational factors (i.e., fatigue) that may impact vigilance and performance. Aspects of the gaze system can...

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

    Science.gov (United States)

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

    1999-01-01

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

  3. Effects of gamma-hydroxybutyrate (GHB) on vigilance states and EEG in mice

    NARCIS (Netherlands)

    Meerlo, P; Westerveld, P; Turek, FW; Koehl, M

    2004-01-01

    Study Objectives: Gamma-hydroxybutyrate (GHB) is an endogenous neuromodulator that appears to have wide-ranging effects on vigilance and behavior. In the present study, we examined the effects of GHB on sleep-wake behavior and EEG in mice. In addition, we measured effects of GHB on body temperature

  4. The Effects of Eight-Month Physical Activity Intervention on Vigilance Performance in Adult Obese Population.

    Science.gov (United States)

    Monleón, Cristina; Ballester, Rafael; Sanchis, Carlos; Llorens, Francesc; Martín, Marta; Pablos, Ana

    2015-01-01

    We aim to analyze the effects of an 8-month physical activity intervention on cardiorespiratory fitness, body mass index (BMI), and vigilance performance in an adult obese population. We conducted an 8-month physical activity intervention based on dance and rhythmic activities. The weekly frequency was 2 sessions of 1 hr per day. Training sessions were divided into 3 phases: a 10-min warm-up, 40 min of dance and rhythmic activities, and 10 min to cool-down. To assess cardiorespiratory fitness, participants performed a modified version of the 6-min walk test from the Senior Fitness Test battery (Larsson & Mattsson, 2001; Rikli & Jones, 1999). Vigilance performance was measured by means of the psychomotor vigilance task (PVT). Two measurements were performed immediately before and after the intervention. The results revealed that participants improved their cardiorespiratory fitness, BMI, and vigilance performance after the intervention. All in all, findings contribute new empirical evidence to the field that investigates the benefits of physical activity intervention on cognitive processes in obese population.

  5. On the preservation of vigilant attention to semantic information in healthy aging.

    Science.gov (United States)

    Thomson, David R; Hasher, Lynn

    2017-07-01

    Despite decades of research on younger adults, little is known about the way in which vigilant attention is affected by healthy aging, and the small body of work that does exist has yielded mixed findings. Prior examinations of aging and vigilant attention have focused almost exclusively on sensory/perceptual tasks despite the fact that many real-world vigilance tasks are semantic in nature and it has been shown that older adults exhibit memory and attention deficits in semantic tasks in other domains. Here, we present the first empirical investigation of vigilant attention to verbal stimuli in healthy normal aging. In Experiment 1 we find that older adults are just as able as younger adults to identify critical targets defined by category membership (both overall and over time). In Experiment 2, we increase the difficulty of the task by changing the target category from one block to the next, but again find no age-group effects in accuracy. Response time data, however, show that older adults respond more slowly and subjective ratings indicate that older adults experience higher workload and arousal compared to their younger counterparts. The practical as well as theoretical implications of these findings are discussed.

  6. Effects of 2 adenosine antagonists, quercetin and caffeine, on vigilance and mood.

    Science.gov (United States)

    Olson, Craig A; Thornton, Jennifer A; Adam, Gina E; Lieberman, Harris R

    2010-10-01

    Quercetin, a phenolic flavonoid found in small quantities in some fruits and vegetables, is an adenosine receptor antagonist in vitro marketed as a dietary supplement for purported caffeine-like effects. A double-blind, placebo-controlled, between-subjects study was conducted to compare the behavioral effects of quercetin to a central adenosine receptor antagonist, caffeine. Fifty-seven volunteers received either 2000 mg of quercetin dihydrate (a dose estimated based on in vitro receptor binding to be equivalent in potency to 200 mg of caffeine), placebo, or 200 mg of caffeine. One hour later, a 45-minute visual vigilance task was administered. The Profile of Mood States questionnaire was completed before treatment and immediately after vigilance testing. On the vigilance task, caffeine increased the number of stimuli detected (P mood disturbance Profile of Mood States scores compared with placebo. Quercetin did not significantly alter any parameter, but values were typically intermediate between caffeine and placebo on those tests affected by caffeine. Quercetin is unlikely to have any effects when consumed by humans in quantities present in the diet or in dietary supplements. Caffeine (200 mg) administration resulted in the expected effects on vigilance and mood.

  7. The relationship between regular sports participation and vigilance in male and female adolescents.

    Science.gov (United States)

    Ballester, Rafael; Huertas, Florentino; Yuste, Francisco Javier; Llorens, Francesc; Sanabria, Daniel

    2015-01-01

    The present study investigated the relationship between regular sport participation (soccer) and vigilance performance. Two groups of male and female adolescents differentiated in terms of their sport participation (athletes, n = 39, and non-athletes, n = 36) took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level. In the other session, participants completed the Psychomotor Vigilance Task (PVT) to evaluate their vigilance performance. Perceived arousal prior to the task and motivation toward the task were also measured in the PVT session. The results revealed that athletes had better cardiovascular fitness and showed better performance in the PVT. However, correlation analyses did not show any significant relationship between cardiovascular fitness and performance in the PVT. Athletes showed larger scores in motivation and perceived arousal measures with respect to non-athletes, although, once again, these variables were not correlated with PVT performance. Gender differences were observed only in the Leger test, with males showing greater fitness level than females. The major outcome of this research points to a positive relationship between regular sport participation and vigilance during adolescence. This relationship did not seem to be influenced by gender, perceived arousal, motivation toward the task or cardiovascular fitness. We discuss our results in terms of the different hypotheses put forward in the literature to explain the relationship between physical activity and cognitive functioning.

  8. The relationship between regular sports participation and vigilance in male and female adolescents.

    Directory of Open Access Journals (Sweden)

    Rafael Ballester

    Full Text Available The present study investigated the relationship between regular sport participation (soccer and vigilance performance. Two groups of male and female adolescents differentiated in terms of their sport participation (athletes, n = 39, and non-athletes, n = 36 took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level. In the other session, participants completed the Psychomotor Vigilance Task (PVT to evaluate their vigilance performance. Perceived arousal prior to the task and motivation toward the task were also measured in the PVT session. The results revealed that athletes had better cardiovascular fitness and showed better performance in the PVT. However, correlation analyses did not show any significant relationship between cardiovascular fitness and performance in the PVT. Athletes showed larger scores in motivation and perceived arousal measures with respect to non-athletes, although, once again, these variables were not correlated with PVT performance. Gender differences were observed only in the Leger test, with males showing greater fitness level than females. The major outcome of this research points to a positive relationship between regular sport participation and vigilance during adolescence. This relationship did not seem to be influenced by gender, perceived arousal, motivation toward the task or cardiovascular fitness. We discuss our results in terms of the different hypotheses put forward in the literature to explain the relationship between physical activity and cognitive functioning.

  9. Differences between Students with and without ADHD on Task Vigilance under Conditions of Distraction

    Science.gov (United States)

    Ross, Peter; Randolph, Justus

    2016-01-01

    Distraction is a typical component of any classroom environment. For effective instruction and learning to take place, it is critical for students to eventually return to task and maintain task vigilance (i.e., returning to the task at hand) when a distraction occurs. Students with attention deficit hyperactivity disorder (ADHD), by definition,…

  10. The meaning and importance of vigilant attendance for the relatives of intensive care unit patients.

    Science.gov (United States)

    Plakas, Sotirios; Taket, Ann; Cant, Bob; Fouka, Georgia; Vardaki, Zambia

    2014-09-01

    To explore the meaning of vigilant attendance for relatives of critically ill patients in Greece. A plethora of international research has identified proximity to the patient to be a major concern for relatives of critically ill patients. Greece however follows a strict visiting policy in intensive care units (ICUs) so Greek relatives spend great amounts of time just outside the ICUs. This qualitative study adopted the social constructionist version of grounded theory. Data were collected from three ICUs in Athens through in depth interviews with 25 informants and approximately 10 h of observations outside the ICUs on 159 relatives. Vigilant attendance was one of the main coping mechanisms identified for relatives. Four subcategories were found to comprise vigilant attendance: (1) being as close as possible to feel relief, (2) being there to find out what is going on, (3) monitoring changes in the loved one and making own diagnosis and (4) interacting with the ICU professionals. Vigilant attendance describes the way in which relatives in Greece stayed outside the ICUs. Relatives felt satisfaction from being close as the best alternative for not actually being inside the ICU and they tried to learn what was going on by alternative methods. By seeing the patients, relatives were also able to make their own diagnoses and could therefore avoid relying solely on information given to them. However, a prerequisite for successful vigilant attendance was to get on well with doctors and nurses. Changes in visiting policies in Greece are needed to meet the needs of relatives adequately. Recommendations for changes with minimal investment of time and funding are made. © 2013 British Association of Critical Care Nurses.

  11. The atomic hypothesis: physical consequences

    International Nuclear Information System (INIS)

    Rivas, Martin

    2008-01-01

    The hypothesis that matter is made of some ultimate and indivisible objects, together with the restricted relativity principle, establishes a constraint on the kind of variables we are allowed to use for the variational description of elementary particles. We consider that the atomic hypothesis not only states the indivisibility of elementary particles, but also that these ultimate objects, if not annihilated, cannot be modified by any interaction so that all allowed states of an elementary particle are only kinematical modifications of any one of them. Therefore, an elementary particle cannot have excited states. In this way, the kinematical group of spacetime symmetries not only defines the symmetries of the system, but also the variables in terms of which the mathematical description of the elementary particles can be expressed in either the classical or the quantum mechanical description. When considering the interaction of two Dirac particles, the atomic hypothesis restricts the interaction Lagrangian to a kind of minimal coupling interaction

  12. Multiple sclerosis: a geographical hypothesis.

    Science.gov (United States)

    Carlyle, I P

    1997-12-01

    Multiple sclerosis remains a rare neurological disease of unknown aetiology, with a unique distribution, both geographically and historically. Rare in equatorial regions, it becomes increasingly common in higher latitudes; historically, it was first clinically recognized in the early nineteenth century. A hypothesis, based on geographical reasoning, is here proposed: that the disease is the result of a specific vitamin deficiency. Different individuals suffer the deficiency in separate and often unique ways. Evidence to support the hypothesis exists in cultural considerations, in the global distribution of the disease, and in its historical prevalence.

  13. Discussion of the Porter hypothesis

    International Nuclear Information System (INIS)

    1999-11-01

    In the reaction to the long-range vision of RMNO, published in 1996, The Dutch government posed the question whether a far-going and progressive modernization policy will lead to competitive advantages of high-quality products on partly new markets. Such a question is connected to the so-called Porter hypothesis: 'By stimulating innovation, strict environmental regulations can actually enhance competitiveness', from which statement it can be concluded that environment and economy can work together quite well. A literature study has been carried out in order to determine under which conditions that hypothesis is endorsed in the scientific literature and policy documents. Recommendations are given for further studies. refs

  14. The thrifty phenotype hypothesis revisited

    DEFF Research Database (Denmark)

    Vaag, A A; Grunnet, L G; Arora, G P

    2012-01-01

    Twenty years ago, Hales and Barker along with their co-workers published some of their pioneering papers proposing the 'thrifty phenotype hypothesis' in Diabetologia (4;35:595-601 and 3;36:62-67). Their postulate that fetal programming could represent an important player in the origin of type 2...... of the underlying molecular mechanisms. Type 2 diabetes is a multiple-organ disease, and developmental programming, with its idea of organ plasticity, is a plausible hypothesis for a common basis for the widespread organ dysfunctions in type 2 diabetes and the metabolic syndrome. Only two among the 45 known type 2...

  15. Cadeias produtivas e a vigilância em saúde, trabalho e ambiente

    Directory of Open Access Journals (Sweden)

    Luís Henrique da Costa Leão

    2015-12-01

    Full Text Available Resumo A globalização da economia alterou o padrão produtivo na atualidade e a formação de cadeias de produção é um fenômeno central nessa nova conjuntura. Cadeias produtivas são processos de extração, produção, transporte, distribuição, consumo e descarte de bens e serviços. Para o seu desenvolvimento existem investimentos governamentais econômicos/financeiros, por vezes em confronto direto com os interesses da proteção da saúde dos trabalhadores e ambiental. Isso porque são gerados diversos danos, riscos e vulnerabilidades sociais, ambientais, sanitárias e ocupacionais ao longo das cadeias. A vigilância em saúde, trabalho e ambiente tem o desafio de enfrentar esses complexos problemas para garantir melhorias para as condições de vida. O objetivo deste ensaio teórico é discutir estratégias de vigilância em saúde, trabalho e ambiente, partindo da noção de cadeia produtiva enquanto redes interconectadas de produção-consumo. O artigo apresenta as principais abordagens teóricas sobre cadeias de produção, especialmente, Supply Chain, Global Commodity Chain, Análise de Filière e Agribussiness, destacando as áreas do conhecimento envolvidas. Discute ainda a fragilidade e incipiência da interseção dos saberes e práticas da vigilância em saúde, trabalho e ambiente com a temática das cadeias produtivas, evidenciando a necessidade de superação da vigilância dos produtos em direção à intervenção em toda a cadeia produtiva, mediante a articulação entre as vigilâncias do SUS. Destaca-se também o papel da academia, dos serviços de saúde e das populações para a implementação dessa vigilância.

  16. Questioning the social intelligence hypothesis.

    Science.gov (United States)

    Holekamp, Kay E

    2007-02-01

    The social intelligence hypothesis posits that complex cognition and enlarged "executive brains" evolved in response to challenges that are associated with social complexity. This hypothesis has been well supported, but some recent data are inconsistent with its predictions. It is becoming increasingly clear that multiple selective agents, and non-selective constraints, must have acted to shape cognitive abilities in humans and other animals. The task now is to develop a larger theoretical framework that takes into account both inter-specific differences and similarities in cognition. This new framework should facilitate consideration of how selection pressures that are associated with sociality interact with those that are imposed by non-social forms of environmental complexity, and how both types of functional demands interact with phylogenetic and developmental constraints.

  17. Whiplash and the compensation hypothesis.

    Science.gov (United States)

    Spearing, Natalie M; Connelly, Luke B

    2011-12-01

    Review article. To explain why the evidence that compensation-related factors lead to worse health outcomes is not compelling, either in general, or in the specific case of whiplash. There is a common view that compensation-related factors lead to worse health outcomes ("the compensation hypothesis"), despite the presence of important, and unresolved sources of bias. The empirical evidence on this question has ramifications for the design of compensation schemes. Using studies on whiplash, this article outlines the methodological problems that impede attempts to confirm or refute the compensation hypothesis. Compensation studies are prone to measurement bias, reverse causation bias, and selection bias. Errors in measurement are largely due to the latent nature of whiplash injuries and health itself, a lack of clarity over the unit of measurement (specific factors, or "compensation"), and a lack of appreciation for the heterogeneous qualities of compensation-related factors and schemes. There has been a failure to acknowledge and empirically address reverse causation bias, or the likelihood that poor health influences the decision to pursue compensation: it is unclear if compensation is a cause or a consequence of poor health, or both. Finally, unresolved selection bias (and hence, confounding) is evident in longitudinal studies and natural experiments. In both cases, between-group differences have not been addressed convincingly. The nature of the relationship between compensation-related factors and health is unclear. Current approaches to testing the compensation hypothesis are prone to several important sources of bias, which compromise the validity of their results. Methods that explicitly test the hypothesis and establish whether or not a causal relationship exists between compensation factors and prolonged whiplash symptoms are needed in future studies.

  18. The Vigil Network: A means of observing landscape change in drainage basins

    Science.gov (United States)

    Osterkamp, W.R.; Emmett, W.W.; Leopold, Luna Bergere

    1991-01-01

    Long-term monitoring of geomorphic, hydrological, and biological characteristics of landscapes provides an effective means of relating observed change to possible causes of the change. Identification of changes in basin characteristics, especially in arid areas where the response to altered climate or land use is generally rapid and readily apparent, might provide the initial direct indications that factors such as global warming and cultural impacts have affected the environment. The Vigil Network provides an opportunity for earth and life scientists to participate in a systematic monitoring effort to detect landscape changes over time, and to relate such changes to possible causes. The Vigil Network is an ever-increasing group of sites and basins used to monitor landscape features with as much as 50 years of documented geomorphic and related observations.

  19. Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.

    Science.gov (United States)

    Allen, Andrew P; Jacob, Tim J C; Smith, Andrew P

    2014-06-22

    Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Effects of continuous exposure to carbon monoxide on auditory vigilance in man

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D.M.; Jolly, E.J.; Pethybridge, R.J.; Colquhoun, W.P.

    1981-02-01

    Six different groups of non-smoking young male subjcts were stutied separately for 18 consecutive days each in a closed controlled-environment human exposure chamber. Each group was subjected to a 5-day control period in fresh air followed successively by an 8-day period of continuous exposure to 50 ppm, 15 ppm or 0 ppm (controll) by volume of carbon monoxide (CO) in air, and a 5-day recovery period in fresh air. The subjects performed a 1-h auditory vigilance task every day at the same time of day in a fixed qualitative, quantitative, and temporal relationship with food intake, consumption of stimulating beverages, physical activity, and sleep. It was concluded that such CO exposure, involving the continuous carriage of carboxyhaemoglobin loads up to 70%, was without significant effect on auditory vigilance.

  1. Nudging social workers towards interpretive vigilance: approaches supporting management of conduct in the workplace

    OpenAIRE

    Meleyal, Lel

    2017-01-01

    In the UK, Government Inquiries into health and social work failures have burgeoned ever more bureaucratic regulatory mechanisms for managing the conduct of professionals. This article draws on the concepts of Nudge Theory and Interpretive Vigilance to consider the impact upon the social work profession of mandatory registration (license) with a regulatory body. The author’s earlier UK based empirical qualitative study found that, as a regulatory method, registration had perverse consequences...

  2. Vigilance-avoidance and disengagement are differentially associated with fear and avoidant behaviors in social anxiety.

    Science.gov (United States)

    Evans, Travis C; Walukevich, Katherine A; Britton, Jennifer C

    2016-07-15

    Individuals with Social Anxiety Disorder (SAD) often exhibit preferential attention for social threat, demonstrating abnormal orientation to threat (i.e., vigilance-avoidance) and/or difficulty disengaging from threat. However, no research has compared the relationship between attention indices (i.e., vigilance-avoidance, difficulty disengaging from threat) and characteristic features of the disorder such as fear during social situations (social fear) and avoidant behaviors (social avoidance). To address this issue, seventy adults (19.29±1.47 years, 33 females) were separated into low (n=37) or high (n=33) socially anxious groups using clinical cutoff scores on the Social Interaction Anxiety Scale (SIAS). Participants in both groups completed a dot-probe task with congruent, incongruent, and neutral trials to obtain measures of vigilance-avoidance and difficulty disengaging. Using linear regression, we examined the associations each attention index shared with self-reported social fear and social avoidance. Exclusively in the high anxious group, greater vigilance towards threat was associated with higher self-reported social fear, but not with social avoidance. However, difficulty disengaging was not associated with either social measure. In the low anxiety group, no relationships between attention indices and either social measure emerged. Future research with clinical samples is necessary to replicate and extend these findings. The small sample size studied may have limited our ability to detect other smaller effects. Indices of attention bias may contribute differently to the etiology and maintenance of SAD, which offers important implications for novel treatments that target attention. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Cold hands, warm feet: sleep deprivation disrupts thermoregulation and its association with vigilance.

    Science.gov (United States)

    Romeijn, Nico; Verweij, Ilse M; Koeleman, Anne; Mooij, Anne; Steimke, Rosa; Virkkala, Jussi; van der Werf, Ysbrand; Van Someren, Eus J W

    2012-12-01

    Vigilance is affected by induced and spontaneous skin temperature fluctuations. Whereas sleep deprivation strongly affects vigilance, no previous study examined in detail its effect on human skin temperature fluctuations and their association with vigilance. In a repeated-measures constant routine design, skin temperatures were assessed continuously from 14 locations while performance was assessed using a reaction time task, including eyes-open video monitoring, performed five times a day for 2 days, after a normal sleep or sleep deprivation night. Participants were seated in a dimly lit, temperature-controlled laboratory. Eight healthy young adults (five males, age 22.0 ± 1.8 yr (mean ± standard deviation)). One night of sleep deprivation. Mixed-effect regression models were used to evaluate the effect of sleep deprivation on skin temperature gradients of the upper (ear-mastoid), middle (hand-arm), and lower (foot-leg) body, and on the association between fluctuations in performance and in temperature gradients. Sleep deprivation induced a marked dissociation of thermoregulatory skin temperature gradients, indicative of attenuated heat loss from the hands co-occurring with enhanced heat loss from the feet. Sleep deprivation moreover attenuated the association between fluctuations in performance and temperature gradients; the association was best preserved for the upper body gradient. Sleep deprivation disrupts coordination of fluctuations in thermoregulatory skin temperature gradients. The dissociation of middle and lower body temperature gradients may therefore be evaluated as a marker for sleep debt, and the upper body gradient as a possible aid in vigilance assessment when sleep debt is unknown. Importantly, our findings suggest that sleep deprivation affects the coordination between skin blood flow fluctuations and the baroreceptor-mediated cardiovascular regulation that prevents venous pooling of blood in the lower limbs when there is the orthostatic

  4. Vigilance and foraging behaviour of female caribou in relation to predation risk

    Directory of Open Access Journals (Sweden)

    Pernille S. Bøving

    1997-02-01

    Full Text Available Behaviour of female caribou (Rangifer tarandus was investigated during the calving season on ranges in Alaska and West Greenland with the purpose of determining whether investment in vigilance behaviour differed between areas with and without natural predators of caribou. Female caribou in Alaska foraged in larger groups, displayed a higher rate of vigilance during feeding, spent less time feeding and, when lying, more often adopted a vigilant posture (with head up than did female caribou in West Greenland. Moreover, a predation-vulnerable posture of lying down flat was observed in West Greenland but not in Alaska. Within Alaska, females with calves spent more time searching the environment than did those without calves. Finally, the amount of time individuals spent searching declined more gradually with group size in Alaska than in West Greenland, suggesting that what caribou perceive as a predator-safe threshold differs in the two areas. These results indicate that caribou, like several other species of ungulates, show behavioural adaptations to the risk of prédation which are relaxed when this risk is reduced.

  5. Donor vigilance data of a blood transfusion service: A multicenter analysis.

    Science.gov (United States)

    Burkhardt, T; Dimanski, B; Karl, R; Sievert, U; Karl, A; Hübler, C; Tonn, T; Sopvinik, I; Ertl, H; Moog, R

    2015-10-01

    Donor vigilance is an important part of the quality management system of blood transfusion services. The evaluation of donor side effects helps to improve the donation process and donor compliance. The aim of the present study was to evaluate donor vigilance data in whole blood and plasmapheresis donors of a blood donor service. Donors fulfilling current national and European eligibility criteria underwent whole blood and plasmapheresis donation (PCS and MCS+ (Haemonetics, Braintree, USA), A 200 (Fenwal, Round Lake, USA). Whole blood was collected at fixed and mobile sites while plasmaphereses were performed at 8 plasma centers. From 2011 to 2013 donor information was provided for gender, age, body weight, height, first and repeat donation. Donors were monitored for venipuncture and circulatory associated side effects. The total incidences of adverse events were 5004 (0.56%) in repeat donors and 2111 (2.78%) in first time donors for whole blood donation and 3323 (1.01%) and 514 (7.96%) for plasmaphereses, respectively. Circulatory associated events were 2679 (0.30%) for whole blood donation and 1624 (0.49%) for plasmaphereses. Our donor vigilance data of a blood transfusion service show that whole blood and plasmapheresis are safe with low incidences of adverse events. Repeat donation and age are predictors for low rates of adverse events. On the other hand, first time donation and female gender were associated with higher incidences of adverse events. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Parallel vigilance: parents' dual focus following diagnosis of Type 1 diabetes mellitus in their young child.

    Science.gov (United States)

    Niedel, Selaine; Traynor, Michael; McKee, Martin; Grey, Margaret

    2013-05-01

    There is consensus that enabling patient self-care and expertise leads to better management of chronic illness. Clinicians are being encouraged to manage clinical encounters in ways that promote these outcomes rather than perpetuate hierarchical relationships. This article describes one part of a larger study of 55 outpatient consultations conducted within 14 months of the diagnosis of Type 1 diabetes mellitus in young children. Participants were parents and the specialist doctors, nurses, dieticians and social workers who oversee the child's secondary care. Consultations were audio-recorded and transcribed. Our analysis draws on aspects of conversation analysis (CA) to investigate how parents' talk enacts a growing confidence in the management of their child's disease in the face of questioning from professionals. Analysis reveals how this talk distinguishes a duality of focus that combines the normal watchfulness exhibited by all parents as they protect their children, with an additional intense, parallel watchfulness for signs of potentially serious manifestations of diabetes. We term this phenomenon parallel vigilance and illustrate its development using five representative extracts from consultations. The concept of parallel vigilance extends the chronic illness literature and informs our understanding of a process that contributes to parents' developing expertise and provides new and important insights into the way in which parents conceptualize and implement their evolving role in the care of their child. Moreover, parallel vigilance serves as an enabler of parental contributions to the specialist consultation.

  7. Coordinated vigilance provides evidence for direct reciprocity in coral reef fishes.

    Science.gov (United States)

    Brandl, Simon J; Bellwood, David R

    2015-09-25

    Reciprocity is frequently assumed to require complex cognitive abilities. Therefore, it has been argued that reciprocity may be restricted to animals that can meet these demands. Here, we provide evidence for the potential presence of direct reciprocity in teleost fishes. We demonstrate that in pairs of coral reef rabbitfishes (f. Siganidae), one fish frequently assumes an upright vigilance position in the water column, while the partner forages in small crevices in the reef substratum. Both behaviours are strongly coordinated and partners regularly alternate their positions, resulting in a balanced distribution of foraging activity. Compared to solitary individuals, fishes in pairs exhibit longer vigilance bouts, suggesting that the help provided to the partner is costly. In turn, fishes in pairs take more consecutive bites and penetrate deeper into crevices than solitary individuals, suggesting that the safety provided by a vigilant partner may outweigh initial costs by increasing foraging efficiency. Thus, the described system appears to meet all of the requirements for direct reciprocity. We argue that the nature of rabbitfish pairs provides favourable conditions for the establishment of direct reciprocity, as continuous interaction with the same partner, simultaneous needs, interdependence, and communication relax the cognitive demands of reciprocal cooperation.

  8. Implicit versus explicit attitude to doping: Which better predicts athletes' vigilance towards unintentional doping?

    Science.gov (United States)

    Chan, Derwin King Chung; Keatley, David A; Tang, Tracy C W; Dimmock, James A; Hagger, Martin S

    2018-03-01

    This preliminary study examined whether implicit doping attitude, explicit doping attitude, or both, predicted athletes' vigilance towards unintentional doping. A cross-sectional correlational design. Australian athletes (N=143;M age =18.13, SD=4.63) completed measures of implicit doping attitude (brief single-category implicit association test), explicit doping attitude (Performance Enhancement Attitude Scale), avoidance of unintentional doping (Self-Reported Treatment Adherence Scale), and behavioural vigilance task of unintentional doping (reading the ingredients of an unfamiliar food product). Positive implicit doping attitude and explicit doping attitude were negatively related to athletes' likelihood of reading the ingredients table of an unfamiliar food product, and positively related to athletes' vigilance towards unintentional doping. Neither attitude measures predicted avoidance of unintentional doping. Overall, the magnitude of associations by implicit doping attitude appeared to be stronger than that of explicit doping attitude. Athletes with positive implicit and explicit doping attitudes were less likely to read the ingredients table of an unknown food product, but were more likely to be aware of the possible presence of banned substances in a certain food product. Implicit doping attitude appeared to explain athletes' behavioural response to the avoidance of unintentional doping beyond variance explained by explicit doping attitude. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. Tax Evasion, Information Reporting, and the Regressive Bias Hypothesis

    DEFF Research Database (Denmark)

    Boserup, Simon Halphen; Pinje, Jori Veng

    A robust prediction from the tax evasion literature is that optimal auditing induces a regressive bias in effective tax rates compared to statutory rates. If correct, this will have important distributional consequences. Nevertheless, the regressive bias hypothesis has never been tested empirically...

  10. EEG-vigilance differences between patients with borderline personality disorder, patients with obsessive-compulsive disorder and healthy controls.

    Science.gov (United States)

    Hegerl, Ulrich; Stein, Michael; Mulert, Christoph; Mergl, Roland; Olbrich, Sebastian; Dichgans, Eva; Rujescu, Dan; Pogarell, Oliver

    2008-04-01

    The regulation of brain activation, as assessed with the EEG, is a state modulated trait. A decline to lowered EEG-vigilance states has been found to be associated with emotional instability in older studies, but has not been systematically studied in patients with borderline personality disorder (BPD). Twenty unmedicated BPD patients were compared to 20 unmedicated patients with obsessive-compulsive disorder (OCD) as well as 20 healthy controls concerning their EEG-vigilance regulation over a 5-min period assessed with an algorithm classifying every artefact-free 2-s EEG segment into the EEG-vigilance state (A1-A3, B (=non-A)). If the alpha power was posterior more than 55% of the whole alpha power (anterior + posterior) in the artefact-free EEG-segments, that segment was marked as A1, if it was anterior more than 55% of the whole alpha power, as A3. For A2 the following rule was defined: Posterior or anterior alpha between 50 and 55% of the whole alpha power.BPD patients showed significantly lower rates of EEG-vigilance state A compared to OCD patients, indicating a lowered EEG-vigilance. All three groups showed a decrease in the rate of EEG-vigilance state A over the 5 min recording period in line with a lowering of vigilance. The study provides evidence for a less stable regulation of EEG-vigilance in BPD compared to OCD patients and is in line with concepts postulating that the behavioural pattern with sensation seeking and impulsivity in BPD has a compensatory and autoregulatory function to stabilize activation of the CNS.

  11. A Molecular–Structure Hypothesis

    Directory of Open Access Journals (Sweden)

    Jan C. A. Boeyens

    2010-11-01

    Full Text Available The self-similar symmetry that occurs between atomic nuclei, biological growth structures, the solar system, globular clusters and spiral galaxies suggests that a similar pattern should characterize atomic and molecular structures. This possibility is explored in terms of the current molecular structure-hypothesis and its extension into four-dimensional space-time. It is concluded that a quantum molecule only has structure in four dimensions and that classical (Newtonian structure, which occurs in three dimensions, cannot be simulated by quantum-chemical computation.

  12. Vigilance and activity time-budget adjustments of wintering hooded cranes, Grus monacha, in human-dominated foraging habitats.

    Science.gov (United States)

    Li, Chunlin; Zhou, Lizhi; Xu, Li; Zhao, Niannian; Beauchamp, Guy

    2015-01-01

    Due to loss and degradation of natural wetlands, waterbirds increasingly rely on surrounding human-dominated habitats to obtain food. Quantifying vigilance patterns, investigating the trade-off among various activities, and examining the underlying mechanisms will help us understand how waterbirds adapt to human-caused disturbances. During two successive winters (November-February of 2012-13 and 2013-14), we studied the hooded crane, Grus monacha, in the Shengjin Lake National Nature Reserve (NNR), China, to investigate how the species responds to human disturbances through vigilance and activity time-budget adjustments. Our results showed striking differences in the behavior of the cranes when foraging in the highly disturbed rice paddy fields found in the buffer zone compared with the degraded natural wetlands in the core area of the NNR. Time spent vigilant decreased with flock size and cranes spent more time vigilant in the human-dominated buffer zone. In the rice paddy fields, the birds were more vigilant but also fed more at the expense of locomotion and maintenance activities. Adult cranes spent more time vigilant and foraged less than juveniles. We recommend habitat recovery in natural wetlands and community co-management in the surrounding human-dominated landscape for conservation of the hooded crane and, generally, for the vast numbers of migratory waterbirds wintering in the middle and lower reaches of the Yangtze River floodplain.

  13. Family members' views on the benefits of harp music vigils for terminally-ill or dying loved ones.

    Science.gov (United States)

    Ganzini, Linda; Rakoski, Alexa; Cohn, Sharilyn; Mularski, Richard A

    2015-02-01

    Music-thanatology is a palliative modality that uses harp and voice to provide bedside vigils, particularly for terminally ill or actively dying. We sought to determine the benefits of music vigils for terminally ill patients. Survey of 55 family members, whose terminally ill loved one experienced a music vigil during hospitalization, regarding effects on the patient's breathing, relaxation, comfort, pain and ability to sleep. Written comments on negative and positive results of the vigils were coded using content analysis. Family members perceived that the vigils resulted in modest improvement in the patients' breathing, relaxation, comfort, and ability to sleep, with fewer positive effects on pain, and almost no negative effects. Open ended comments focused on the positive benefit in increasing calm, relaxation, comfort. Comments on the positive effects for the family were almost as common as comments on the positive results for the patient. The use of music-vigils in palliative care should be investigated more extensively as our study supports that this intervention has benefits, almost no risk, minimal cost, and may improve patient-family experience of the dying process.

  14. Is PMI the Hypothesis or the Null Hypothesis?

    Science.gov (United States)

    Tarone, Aaron M; Sanford, Michelle R

    2017-09-01

    Over the past several decades, there have been several strident exchanges regarding whether forensic entomologists estimate the postmortem interval (PMI), minimum PMI, or something else. During that time, there has been a proliferation of terminology reflecting this concern regarding "what we do." This has been a frustrating conversation for some in the community because much of this debate appears to be centered on what assumptions are acknowledged directly and which are embedded within a list of assumptions (or ignored altogether) in the literature and in case reports. An additional component of the conversation centers on a concern that moving away from the use of certain terminology like PMI acknowledges limitations and problems that would make the application of entomology appear less useful in court-a problem for lawyers, but one that should not be problematic for scientists in the forensic entomology community, as uncertainty is part of science that should and can be presented effectively in the courtroom (e.g., population genetic concepts in forensics). Unfortunately, a consequence of the way this conversation is conducted is that even as all involved in the debate acknowledge the concerns of their colleagues, parties continue to talk past one another advocating their preferred terminology. Progress will not be made until the community recognizes that all of the terms under consideration take the form of null hypothesis statements and that thinking about "what we do" as a null hypothesis has useful legal and scientific ramifications that transcend arguments over the usage of preferred terminology. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. The Stoichiometric Divisome: A Hypothesis

    Directory of Open Access Journals (Sweden)

    Waldemar eVollmer

    2015-05-01

    Full Text Available Dividing Escherichia coli cells simultaneously constrict the inner membrane, peptidoglycan layer and outer membrane to synthesize the new poles of the daughter cells. For this, more than 30 proteins localize to mid-cell where they form a large, ring-like assembly, the divisome, facilitating division. Although the precise function of most divisome proteins is unknown, it became apparent in recent years that dynamic protein-protein interactions are essential for divisome assembly and function. However, little is known about the nature of the interactions involved and the stoichiometry of the proteins within the divisome. A recent study (Li et al., 2014 used ribosome profiling to measure the absolute protein synthesis rates in E. coli. Interestingly, they observed that most proteins which participate in known multiprotein complexes are synthesized proportional to their stoichiometry. Based on this principle we present a hypothesis for the stoichiometry of the core of the divisome, taking into account known protein-protein interactions. From this hypothesis we infer a possible mechanism for PG synthesis during division.

  16. A Hypothesis-Driven Approach to Site Investigation

    Science.gov (United States)

    Nowak, W.

    2008-12-01

    Variability of subsurface formations and the scarcity of data lead to the notion of aquifer parameters as geostatistical random variables. Given an information need and limited resources for field campaigns, site investigation is often put into the context of optimal design. In optimal design, the types, numbers and positions of samples are optimized under case-specific objectives to meet the information needs. Past studies feature optimal data worth (balancing maximum financial profit in an engineering task versus the cost of additional sampling), or aim at a minimum prediction uncertainty of stochastic models for a prescribed investigation budget. Recent studies also account for other sources of uncertainty outside the hydrogeological range, such as uncertain toxicity, ingestion and behavioral parameters of the affected population when predicting the human health risk from groundwater contaminations. The current study looks at optimal site investigation from a new angle. Answering a yes/no question under uncertainty directly requires recasting the original question as a hypothesis test. Otherwise, false confidence in the resulting answer would be pretended. A straightforward example is whether a recent contaminant spill will cause contaminant concentrations in excess of a legal limit at a nearby drinking water well. This question can only be answered down to a specified chance of error, i.e., based on the significance level used in hypothesis tests. Optimal design is placed into the hypothesis-driven context by using the chance of providing a false yes/no answer as new criterion to be minimized. Different configurations apply for one-sided and two-sided hypothesis tests. If a false answer entails financial liability, the hypothesis-driven context can be re-cast in the context of data worth. The remaining difference is that failure is a hard constraint in the data worth context versus a monetary punishment term in the hypothesis-driven context. The basic principle

  17. Vigilance cartographique.

    Directory of Open Access Journals (Sweden)

    Patrick Poncet

    2004-09-01

    Full Text Available Si la carte du climat social en France n'est souvent dressée qu'après la catastrophe électorale, celle du climat tout court s'efforce en tout cas de prévenir la désillusion d'un pique-nique avorté par la pluie. Est-ce à dire que, dans nos sociétés, on préfère prévoir l'aléa plutôt que voir de près l'électorat ? Probablement. C'est du moins ce que l'on serait tenté de conclure de la publication récente, sur le site internet de Météo France , ...

  18. Partial agonism at the α7 nicotinic acetylcholine receptor improves attention, impulsive action and vigilance in low attentive rats.

    Science.gov (United States)

    Hayward, Andrew; Adamson, Lisa; Neill, Joanna C

    2017-04-01

    Inattention is a disabling symptom in conditions such as schizophrenia and attention deficit/hyperactivity disorder. Nicotine can improve attention and vigilance, but is unsuitable for clinical use due to abuse liability. Genetic knockout of the α7 nicotinic acetylcholine receptor (nAChR) induces attention deficits therefore selective agonism may improve attention, without the abuse liability associated with nicotine. The α7 nAChR partial agonist encenicline (formerly EVP-6124) enhances memory in rodents and humans. Here we investigate, for the first time, efficacy of encenicline to improve attention and vigilance in animals behaviourally grouped for low attentive traits in the 5 choice-continuous performance task (5C-CPT). Female Lister Hooded rats were trained to perform the 5C-CPT with a variable stimulus duration (SD). Animals were then grouped based on performance into upper and lower quartiles of d' (vigilance) and accuracy (selective attention), producing high-attentive (HA) and low-attentive (LA) groups. LA animals showed an increase in selective attention and vigilance at 0.3mg/kg encenicline, a reduction in impulsive action (probability of false alarms) and increase in vigilance following 1mg/kg at 0.75sSD. At 1mg/kg, HA animals had reduced selective attention at 0.75sSD and reduced vigilance at 0.75 and 1.25sSD. Improvement of attention, vigilance and impulsive action in LA animals demonstrates that encenicline has pro-attentive properties dependent on baseline levels of performance. Our work suggests that α7 nAChR partial agonism may improve attention particularly in conditions with low attention. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

  19. Biostatistics series module 2: Overview of hypothesis testing

    Directory of Open Access Journals (Sweden)

    Avijit Hazra

    2016-01-01

    Full Text Available Hypothesis testing (or statistical inference is one of the major applications of biostatistics. Much of medical research begins with a research question that can be framed as a hypothesis. Inferential statistics begins with a null hypothesis that reflects the conservative position of no change or no difference in comparison to baseline or between groups. Usually, the researcher has reason to believe that there is some effect or some difference which is the alternative hypothesis. The researcher therefore proceeds to study samples and measure outcomes in the hope of generating evidence strong enough for the statistician to be able to reject the null hypothesis. The concept of the P value is almost universally used in hypothesis testing. It denotes the probability of obtaining by chance a result at least as extreme as that observed, even when the null hypothesis is true and no real difference exists. Usually, if P is < 0.05 the null hypothesis is rejected and sample results are deemed statistically significant. With the increasing availability of computers and access to specialized statistical software, the drudgery involved in statistical calculations is now a thing of the past, once the learning curve of the software has been traversed. The life sciences researcher is therefore free to devote oneself to optimally designing the study, carefully selecting the hypothesis tests to be applied, and taking care in conducting the study well. Unfortunately, selecting the right test seems difficult initially. Thinking of the research hypothesis as addressing one of five generic research questions helps in selection of the right hypothesis test. In addition, it is important to be clear about the nature of the variables (e.g., numerical vs. categorical; parametric vs. nonparametric and the number of groups or data sets being compared (e.g., two or more than two at a time. The same research question may be explored by more than one type of hypothesis test

  20. The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise

    Directory of Open Access Journals (Sweden)

    Shaun Steven Killen

    2015-04-01

    Full Text Available When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fuelled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope or recovery time after exhaustive exercise. Slower recovery ability or a reduced aerobic scope could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how aerobic scope and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden grey mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26oC, then measured for standard and maximal metabolic rates and aerobic scope using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasise that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with

  1. Vigilant attention to threat, sleep patterns, and anxiety in peripubertal youth.

    Science.gov (United States)

    Ricketts, Emily J; Price, Rebecca B; Siegle, Greg J; Silk, Jennifer S; Forbes, Erika E; Ladouceur, Cecile D; Harvey, Allison G; Ryan, Neal D; Dahl, Ronald E; McMakin, Dana L

    2018-05-02

    Vigilant attention to threat is commonly observed in anxiety, undergoes developmental changes in early adolescence, and has been proposed to interfere with sleep initiation and maintenance. We present one of the first studies to use objective measures to examine associations between vigilant attention to threat and difficulties initiating and maintaining sleep in an early adolescent anxious sample. We also explore the moderating role of development (age, puberty) and sex. Participants were 66 peripubertal youth (ages 9-14) with a primary anxiety disorder and 24 healthy control subjects. A dot-probe task was used to assess attentional bias to fearful relative to neutral face stimuli. Eye-tracking indexed selective attentional bias to threat, and reaction time bias indexed action readiness to threat. Sleep was assessed via actigraphy (e.g. sleep onset delay, wake after sleep onset, etc.), parent report (Children's Sleep Habits Questionnaire), and child report (Sleep Self-Report). The Pediatric Anxiety Rating Scale assessed anxiety severity. Eye-tracking initial threat fixation bias (β = .33, p = .001) and threat dwell time bias (β = .22, p = .041) were positively associated with sleep onset latency. Reaction time bias was positively associated with wake after sleep onset (β = .24, p = .026) and parent-reported sleep disturbance (β = .25, p = .019). Anxiety (severity, diagnosis) was not associated with these outcomes. Sex (β = -.32, p = .036) moderated the relation between initial threat fixation bias and sleep onset latency, with a positive association for males (p = .005), but not for females (p = .289). Age and pubertal status did not moderate effects. Vigilant attention to threat is related to longer sleep onset and reduced sleep maintenance. These associations are not stronger in early adolescents with anxiety. Implications for early intervention or prevention that targets vigilant attention to threat to impact sleep disturbance, and

  2. The Importance of Being Vigilant: Has ECB Communication Influenced Euro Area Inflation Expectations?

    OpenAIRE

    David-Jan Jansen; Jakob de Haan

    2007-01-01

    Using daily data on inflation-indexed bonds, we find evidence of a negative relationship between ECB communication regarding risks to price stability - measured on the basis of the frequency and strength of the keyword ‘vigilance’ - and changes in euro area break-even inflation. However, this result is only found for the second half of 2005. At that time, the start of a tightening of ECB monetary policy was increasingly likely. This suggests that communication should be closely in line wi...

  3. Memory in astrocytes: a hypothesis

    Directory of Open Access Journals (Sweden)

    Caudle Robert M

    2006-01-01

    Full Text Available Abstract Background Recent work has indicated an increasingly complex role for astrocytes in the central nervous system. Astrocytes are now known to exchange information with neurons at synaptic junctions and to alter the information processing capabilities of the neurons. As an extension of this trend a hypothesis was proposed that astrocytes function to store information. To explore this idea the ion channels in biological membranes were compared to models known as cellular automata. These comparisons were made to test the hypothesis that ion channels in the membranes of astrocytes form a dynamic information storage device. Results Two dimensional cellular automata were found to behave similarly to ion channels in a membrane when they function at the boundary between order and chaos. The length of time information is stored in this class of cellular automata is exponentially related to the number of units. Therefore the length of time biological ion channels store information was plotted versus the estimated number of ion channels in the tissue. This analysis indicates that there is an exponential relationship between memory and the number of ion channels. Extrapolation of this relationship to the estimated number of ion channels in the astrocytes of a human brain indicates that memory can be stored in this system for an entire life span. Interestingly, this information is not affixed to any physical structure, but is stored as an organization of the activity of the ion channels. Further analysis of two dimensional cellular automata also demonstrates that these systems have both associative and temporal memory capabilities. Conclusion It is concluded that astrocytes may serve as a dynamic information sink for neurons. The memory in the astrocytes is stored by organizing the activity of ion channels and is not associated with a physical location such as a synapse. In order for this form of memory to be of significant duration it is necessary

  4. Robust and distributed hypothesis testing

    CERN Document Server

    Gül, Gökhan

    2017-01-01

    This book generalizes and extends the available theory in robust and decentralized hypothesis testing. In particular, it presents a robust test for modeling errors which is independent from the assumptions that a sufficiently large number of samples is available, and that the distance is the KL-divergence. Here, the distance can be chosen from a much general model, which includes the KL-divergence as a very special case. This is then extended by various means. A minimax robust test that is robust against both outliers as well as modeling errors is presented. Minimax robustness properties of the given tests are also explicitly proven for fixed sample size and sequential probability ratio tests. The theory of robust detection is extended to robust estimation and the theory of robust distributed detection is extended to classes of distributions, which are not necessarily stochastically bounded. It is shown that the quantization functions for the decision rules can also be chosen as non-monotone. Finally, the boo...

  5. Alien abduction: a medical hypothesis.

    Science.gov (United States)

    Forrest, David V

    2008-01-01

    In response to a new psychological study of persons who believe they have been abducted by space aliens that found that sleep paralysis, a history of being hypnotized, and preoccupation with the paranormal and extraterrestrial were predisposing experiences, I noted that many of the frequently reported particulars of the abduction experience bear more than a passing resemblance to medical-surgical procedures and propose that experience with these may also be contributory. There is the altered state of consciousness, uniformly colored figures with prominent eyes, in a high-tech room under a round bright saucerlike object; there is nakedness, pain and a loss of control while the body's boundaries are being probed; and yet the figures are thought benevolent. No medical-surgical history was apparently taken in the above mentioned study, but psychological laboratory work evaluated false memory formation. I discuss problems in assessing intraoperative awareness and ways in which the medical hypothesis could be elaborated and tested. If physicians are causing this syndrome in a percentage of patients, we should know about it; and persons who feel they have been abducted should be encouraged to inform their surgeons and anesthesiologists without challenging their beliefs.

  6. The oxidative hypothesis of senescence

    Directory of Open Access Journals (Sweden)

    Gilca M

    2007-01-01

    Full Text Available The oxidative hypothesis of senescence, since its origin in 1956, has garnered significant evidence and growing support among scientists for the notion that free radicals play an important role in ageing, either as "damaging" molecules or as signaling molecules. Age-increasing oxidative injuries induced by free radicals, higher susceptibility to oxidative stress in short-lived organisms, genetic manipulations that alter both oxidative resistance and longevity and the anti-ageing effect of caloric restriction and intermittent fasting are a few examples of accepted scientific facts that support the oxidative theory of senescence. Though not completely understood due to the complex "network" of redox regulatory systems, the implication of oxidative stress in the ageing process is now well documented. Moreover, it is compatible with other current ageing theories (e.g., those implicating the mitochondrial damage/mitochondrial-lysosomal axis, stress-induced premature senescence, biological "garbage" accumulation, etc. This review is intended to summarize and critically discuss the redox mechanisms involved during the ageing process: sources of oxidant agents in ageing (mitochondrial -electron transport chain, nitric oxide synthase reaction- and non-mitochondrial- Fenton reaction, microsomal cytochrome P450 enzymes, peroxisomal β -oxidation and respiratory burst of phagocytic cells, antioxidant changes in ageing (enzymatic- superoxide dismutase, glutathione-reductase, glutathion peroxidase, catalase- and non-enzymatic glutathione, ascorbate, urate, bilirubine, melatonin, tocopherols, carotenoids, ubiquinol, alteration of oxidative damage repairing mechanisms and the role of free radicals as signaling molecules in ageing.

  7. Three-year Follow up of GMCSF/bi-shRNA(furin) DNA-transfected Autologous Tumor Immunotherapy (Vigil) in Metastatic Advanced Ewing's Sarcoma.

    Science.gov (United States)

    Ghisoli, Maurizio; Barve, Minal; Mennel, Robert; Lenarsky, Carl; Horvath, Staci; Wallraven, Gladice; Pappen, Beena O; Whiting, Sam; Rao, Donald; Senzer, Neil; Nemunaitis, John

    2016-08-01

    Ewing's sarcoma is a devastating rare pediatric cancer of the bone. Intense chemotherapy temporarily controls disease in most patients at presentation but has limited effect in patients with progressive or recurrent disease. We previously described preliminary results of a novel immunotherapy, FANG (Vigil) vaccine, in which 12 advanced stage Ewing's patients were safely treated and went on to achieve a predicted immune response (IFNγ ELISPOT). We describe follow-up through year 3 of a prospective, nonrandomized study comparing an expanded group of Vigil-treated advanced disease Ewing's sarcoma patients (n = 16) with a contemporaneous group of Ewing's sarcoma patients (n = 14) not treated with Vigil. Long-term follow-up results show a survival benefit without evidence of significant toxicity (no ≥ grade 3) to Vigil when administered once monthly by intradermal injection (1 × 10e(6) cells/injection to 1 × 10e(7) cells/injection). Specifically, we report a 1-year actual survival of 73% for Vigil-treated patients compared to 23% in those not treated with Vigil. In addition, there was a 17.2-month difference in overall survival (OS; Kaplan-Meier) between the Vigil (median OS 731 days) and no Vigil patient groups (median OS 207 days). In conclusion, these results supply the rational for further testing of Vigil in advanced stage Ewing's sarcoma.

  8. Training for vigilance on the move: a video game-based paradigm for sustained attention.

    Science.gov (United States)

    Szalma, J L; Daly, T N; Teo, G W L; Hancock, G M; Hancock, P A

    2018-04-01

    The capacity for superior vigilance can be trained by using knowledge of results (KR). Our present experiments demonstrate the efficacy of such training using a first-person perspective movement videogame-based platform in samples of students and Soldiers. Effectiveness was assessed by manipulating KR during a training phase and withdrawing it in a subsequent transfer phase. Relative to a no KR control condition, KR systematically improved performance for both Soldiers and students. These results build upon our previous findings that demonstrated that a video game-based platform can be used to create a movement-centred sustained attention task with important elements of traditional vigilance. The results indicate that KR effects in sustained attention extend to a first person perspective movement based paradigm, and that these effects occur in professional military as well as a more general population. Such sustained attention training can save lives and the present findings demonstrate one particular avenue to achieve this goal. Practitioner Summary: Sustained attention can be trained by means of knowledge of results using a videogame-based platform with samples of students and Soldiers. Four experiments demonstrate that a dynamic, first-person perspective video game environment can serve to support effective sustained attention training in professional military as well as a more general population.

  9. Role of multisensory stimuli in vigilance enhancement- a single trial event related potential study.

    Science.gov (United States)

    Abbasi, Nida Itrat; Bodala, Indu Prasad; Bezerianos, Anastasios; Yu Sun; Al-Nashash, Hasan; Thakor, Nitish V

    2017-07-01

    Development of interventions to prevent vigilance decrement has important applications in sensitive areas like transportation and defence. The objective of this work is to use multisensory (visual and haptic) stimuli for cognitive enhancement during mundane tasks. Two different epoch intervals representing sensory perception and motor response were analysed using minimum variance distortionless response (MVDR) based single trial ERP estimation to understand the performance dependency on both factors. Bereitschaftspotential (BP) latency L3 (r=0.6 in phase 1 (visual) and r=0.71 in phase 2 (visual and haptic)) was significantly correlated with reaction time as compared to that of sensory ERP latency L2 (r=0.1 in both phase 1 and phase 2). This implies that low performance in monotonous tasks is predominantly dependent on the prolonged neural interaction with the muscles to initiate movement. Further, negative relationship was found between the ERP latencies related to sensory perception and Bereitschaftspotential (BP) and occurrence of epochs when multisensory cues are provided. This means that vigilance decrement is reduced with the help of multisensory stimulus presentation in prolonged monotonous tasks.

  10. Intraindividual variability in vigilance performance: does degrading visual stimuli mimic age-related "neural noise"?

    Science.gov (United States)

    MacDonald, Stuart W S; Hultsch, David F; Bunce, David

    2006-07-01

    Intraindividual performance variability, or inconsistency, has been shown to predict neurological status, physiological functioning, and age differences and declines in cognition. However, potential moderating factors of inconsistency are not well understood. The present investigation examined whether inconsistency in vigilance response latencies varied as a function of time-on-task and task demands by degrading visual stimuli in three separate conditions (10%, 20%, and 30%). Participants were 24 younger women aged 21 to 30 years (M = 24.04, SD = 2.51) and 23 older women aged 61 to 83 years (M = 68.70, SD = 6.38). A measure of within-person inconsistency, the intraindividual standard deviation (ISD), was computed for each individual across reaction time (RT) trials (3 blocks of 45 event trials) for each condition of the vigilance task. Greater inconsistency was observed with increasing stimulus degradation and age, even after controlling for group differences in mean RTs and physical condition. Further, older adults were more inconsistent than younger adults for similar degradation conditions, with ISD scores for younger adults in the 30% condition approximating estimates observed for older adults in the 10% condition. Finally, a measure of perceptual sensitivity shared increasing negative associations with ISDs, with this association further modulated as a function of age but to a lesser degree by degradation condition. Results support current hypotheses suggesting that inconsistency serves as a marker of neurological integrity and are discussed in terms of potential underlying mechanisms.

  11. Anticipatory vigilance: A grounded theory study of minimising risk within the perioperative setting.

    Science.gov (United States)

    O'Brien, Brid; Andrews, Tom; Savage, Eileen

    2018-01-01

    To explore and explain how nurses minimise risk in the perioperative setting. Perioperative nurses care for patients who are having surgery or other invasive explorative procedures. Perioperative care is increasingly focused on how to improve patient safety. Safety and risk management is a global priority for health services in reducing risk. Many studies have explored safety within the healthcare settings. However, little is known about how nurses minimise risk in the perioperative setting. Classic grounded theory. Ethical approval was granted for all aspects of the study. Thirty-seven nurses working in 11 different perioperative settings in Ireland were interviewed and 33 hr of nonparticipant observation was undertaken. Concurrent data collection and analysis was undertaken using theoretical sampling. Constant comparative method, coding and memoing and were used to analyse the data. Participants' main concern was how to minimise risk. Participants resolved this through engaging in anticipatory vigilance (core category). This strategy consisted of orchestrating, routinising and momentary adapting. Understanding the strategies of anticipatory vigilance extends and provides an in-depth explanation of how nurses' behaviour ensures that risk is minimised in a complex high-risk perioperative setting. This is the first theory situated in the perioperative area for nurses. This theory provides a guide and understanding for nurses working in the perioperative setting on how to minimise risk. It makes perioperative nursing visible enabling positive patient outcomes. This research suggests the need for training and education in maintaining safety and minimising risk in the perioperative setting. © 2017 John Wiley & Sons Ltd.

  12. Detrimental effects of gum chewing on vigilance in children with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Tucha, Lara; Simpson, William; Evans, Lynsay; Birrel, Laura; Sontag, Thomas A; Lange, Klaus W; Tucha, Oliver

    2010-12-01

    Impairments of attention are cardinal features of attention deficit hyperactivity disorder (ADHD) and can seriously affect the daily life of children with ADHD. Despite effective treatment strategies, there is a need of further treatment options that can be added to available and well established treatments. Further treatment options are needed since available treatments are often time consuming, expensive and limited regarding their external validity. Recent research demonstrated that gum chewing has beneficial effects on cognition including certain aspects of attention. Therefore, gum chewing may benefit children with ADHD in situations requiring particular cognitive efforts. In a crossover study, attentional functioning of 32 children with ADHD and 32 children without the condition was examined. All participants were assessed with chewing gum and without chewing gum. A computerized test was used for the assessment of vigilance and sustained attention. The findings of the present study suggest that gum chewing during task execution has detrimental effects on vigilance of both healthy children and children with ADHD. Sustained attention was not affected by gum chewing. Chewing gum, therefore, appears not to improve attentional performance in children with ADHD. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Vigilance and iconic memory in children at high risk for alcoholism.

    Science.gov (United States)

    Steinhauer, S R; Locke, J; Hill, S Y

    1997-07-01

    Previous studies report reduced visual event-related potential (ERP) amplitudes in young males at high risk for alcoholism. These findings could involve difficulties at several stages of visual processing. This study was aimed at examining vigilance performance and iconic memory functions in children at high risk or low risk for alcoholism. Sustained vigilance and retrieval from iconic memory were evaluated in 54 (29 male) white children at high risk and 47 (25 male) white children at low risk for developing alcoholism. Children were also grouped according to gender and age (younger: 8-12 years; older: 13-18 years). No differences is visual sensitivity, response criterion or reaction time were associated with risk status on the degraded visual stimulus version of the Continuous Performance Test. For the Span of Apprehension, no differences were found due to risk status when only 1 or 5 distractors were presented, although with 9 distractors a significant effect of risk status was found when it was tested as an interaction with gender and age (decreased accuracy for older high-risk boys compared to older low-risk boys). These findings suggest that ERP deviations are not attributable to stages of visual processing deficits, but represent difficulty involving more complex utilization of information. Implications of these results are that the differences between high- and low-risk children that have been reported previously for visual ERP components (e.g., P300) are not attributable to deficits of attentional or iconic memory mechanisms.

  14. Robust estimation and hypothesis testing

    CERN Document Server

    Tiku, Moti L

    2004-01-01

    In statistical theory and practice, a certain distribution is usually assumed and then optimal solutions sought. Since deviations from an assumed distribution are very common, one cannot feel comfortable with assuming a particular distribution and believing it to be exactly correct. That brings the robustness issue in focus. In this book, we have given statistical procedures which are robust to plausible deviations from an assumed mode. The method of modified maximum likelihood estimation is used in formulating these procedures. The modified maximum likelihood estimators are explicit functions of sample observations and are easy to compute. They are asymptotically fully efficient and are as efficient as the maximum likelihood estimators for small sample sizes. The maximum likelihood estimators have computational problems and are, therefore, elusive. A broad range of topics are covered in this book. Solutions are given which are easy to implement and are efficient. The solutions are also robust to data anomali...

  15. ALCOol, vigiLAnce, Charge de travail : facteurs d'accident chez les jeunes conducteurs. Rapport final ALCOLAC

    OpenAIRE

    BERTHELON, Catherine; GALY, Edith; PAXION, Julie; FERRIER, Laurent

    2016-01-01

    D'après le modèle de courbe en U renversé d'Ansseau et Timsit-Berthier (1987 ; in Hadj-Mabrouk, 2001), le niveau de performance augmente avec celui de la vigilance jusqu'à un optimum, au-delà de cet optimum l'augmentation de la vigilance entraîne au contraire une baisse de la performance. L'excès de vigilance que représentent la tension (stress) ou l'hyperexcitation a un pouvoir de dégradation plus rapide sur les activités complexes que sur les activités les plus simples. Il y a donc un nivea...

  16. Hypothesis test for synchronization: twin surrogates revisited.

    Science.gov (United States)

    Romano, M Carmen; Thiel, Marco; Kurths, Jürgen; Mergenthaler, Konstantin; Engbert, Ralf

    2009-03-01

    The method of twin surrogates has been introduced to test for phase synchronization of complex systems in the case of passive experiments. In this paper we derive new analytical expressions for the number of twins depending on the size of the neighborhood, as well as on the length of the trajectory. This allows us to determine the optimal parameters for the generation of twin surrogates. Furthermore, we determine the quality of the twin surrogates with respect to several linear and nonlinear statistics depending on the parameters of the method. In the second part of the paper we perform a hypothesis test for phase synchronization in the case of experimental data from fixational eye movements. These miniature eye movements have been shown to play a central role in neural information processing underlying the perception of static visual scenes. The high number of data sets (21 subjects and 30 trials per person) allows us to compare the generated twin surrogates with the "natural" surrogates that correspond to the different trials. We show that the generated twin surrogates reproduce very well all linear and nonlinear characteristics of the underlying experimental system. The synchronization analysis of fixational eye movements by means of twin surrogates reveals that the synchronization between the left and right eye is significant, indicating that either the centers in the brain stem generating fixational eye movements are closely linked, or, alternatively that there is only one center controlling both eyes.

  17. Validity of Linder Hypothesis in Bric Countries

    Directory of Open Access Journals (Sweden)

    Rana Atabay

    2016-03-01

    Full Text Available In this study, the theory of similarity in preferences (Linder hypothesis has been introduced and trade in BRIC countries has been examined whether the trade between these countries was valid for this hypothesis. Using the data for the period 1996 – 2010, the study applies to panel data analysis in order to provide evidence regarding the empirical validity of the Linder hypothesis for BRIC countries’ international trade. Empirical findings show that the trade between BRIC countries is in support of Linder hypothesis.

  18. Human vigilance investigation analysis of the pattern array test (further data analysis). Final report

    International Nuclear Information System (INIS)

    Have, A.C.

    1979-04-01

    This report analyzes a test which was designed to help solve problems of human vigilance encountered in a material safeguard system. The test was designed to determine the efficiency of an operator when processing large amounts of information from a video screen over extended periods of time. In the test eight objects, either circles, squares, or triangles, were set in a 5 x 5 matrix which appeared on a video screen. The eight objects were shown for a specified length of time, the screen blanked out for another specified period, then eight objects in the same 5 x 5 matrix were again shown. The observer was tested on his ability to discern changes in patterns and/or symbols from frame to frame. The testees were able to identify changes in pattern easier than changes in symbols

  19. Vigilância da peste no Estado do Ceará: 1990-1999

    OpenAIRE

    Aragão,Antônia Ivoneida; Seoane,Antônio Carlos M.; Leal,Tereza Cristina Arcanjo; Leal,Nilma Cintra; Almeida,Alzira Maria Paiva de

    2002-01-01

    As atividades de vigilância sorológica da peste nos focos do Estado do Ceará detectaram elevação do número de animais indicadores/sentinela com anticorpos antipestosos a partir de 1995, com pico em 1997 evidenciando aumento da circulação do bacilo pestoso em todos os focos investigados. De um total de 110.725 amostras de soro obtidas de roedores (7.873) e carnívoros domésticos (102.852) analisadas pela técnica de hemaglutinação (HA) para detecção de anticorpos contra o antígeno F1 da Yersinia...

  20. Fast vigilance decrement in closed head injury patients as reflected by the mismatch negativity (MMN).

    Science.gov (United States)

    Kaipio, M L; Novitski, N; Tervaniemi, M; Alho, K; Ohman, J; Salonen, O; Näätänen, R

    2001-05-25

    Event-related potentials (ERPs) were measured from 24 chronic closed head injury (CHI) patients and 18 age- and education-matched controls. The oddball paradigm was applied while subjects were watching a silent movie. The standard (p=0.8) sound of 75 ms duration had a basic frequency of 500 Hz with harmonic partials of 1000 Hz and 1500 Hz, whereas these frequencies for the pitch deviant were each 10% higher. The frequencies of the duration deviant matched with those of the standard but was 25 ms in duration. The MMN (mismatch negativity), generated by the brain's automatic auditory change-detector mechanism, was elicited by both deviants. No significant differences in the MMN latency or amplitude for either pitch or duration deviants were found between the groups. However, the MMN amplitude for the pitch deviant decreased in the patient group during the experiment considerably faster than in controls, suggesting a faster vigilance decrement in the patients.

  1. Flow assurance : complex phase behavior and complex work requires confidence and vigilance

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.D. [ConocoPhillips, Major Projects, Advanced Integrated Simulation, Houston, TX (United States)

    2008-07-01

    Petroleum exploration and development projects and operations increasingly rely on flow assurance definition. Flow assurance is an integrating discipline as it follows the fluid from the reservoir to the market. Flow assurance works across complex technical and non-technical interfaces, including the reservoir, well completions, operation processes, project management, physical/organic chemistry, fluid mechanics, chemical engineering, mechanical engineering and corrosion. The phase behaviour in real fluids also has complex interfaces. The understanding and management of flow assurance of complex phase behaviour must be well communicated in order to enable proper selection, execution, and operation of development concepts designed to manage successful production within the fluid's phase behaviour. Simulation tools facilitate the translation of science into engineering. Academic, industrial, and field research is the core of these tools. The author cautioned that vigilance is required to assist and identify the right time to move innovation into the core tools.

  2. Perspectives on radioactive waste repository monitoring. Confirmation, compliance, confidence building, and societal vigilance

    Energy Technology Data Exchange (ETDEWEB)

    Bergmans, Anne [Antwerp Univ. (Belgium). Research Group Society and Environment; Elam, Mark [Gothenburg Univ. (Sweden); Simmons, Peter [East Anglia Univ., Norwich (United Kingdom); Sundqvist, Goeran [Oslo Univ. (Norway)

    2012-12-15

    Monitoring is now widely seen as a necessary part of programmes for the geological disposal of radioactive waste. However, we find different perspectives on the nature and role of monitoring. Among technical experts it is viewed firstly as a matter of performance confirmation, a tool for validating the safety case underlying repository construction. Among concerned citizens we find a view of monitoring as enabling the critical scrutiny of safety, an instrument for acknowledging uncertainties and detecting emergent problems in a repository. After outlining differing views on questions of whether, why, what, where and for how long to monitor we discuss monitoring in light of constant vigilance as a technical and moral principle of nuclear safety. We suggest that ''how much monitoring'' and ''how should it be organised'' are societal questions and as such need to be broadly discussed.

  3. Effects of zolpidem on sleep architecture, night time ventilation, daytime vigilance and performance in heavy snorers.

    Science.gov (United States)

    Quera-Salva, M A; McCann, C; Boudet, J; Frisk, M; Borderies, P; Meyer, P

    1994-01-01

    1. In a double-blind, crossover, placebo controlled trial, zolpidem 10 mg, a new imidazopyridine hypnotic drug, was administered in a single dose to 10 healthy non-obese heavy snorers. 2. Nocturnal polysomnography showed that zolpidem increased total sleep time, sleep efficiency and the percentage of stage 2. 3. Respiratory monitoring showed that zolpidem did not modify the percentage of total sleep time spent snoring. The percentages of total sleep time with a SaO2 < 4% of the baseline value and with a SaO2 < 90% and the mean SaO2 were also unchanged with zolpidem. The respiratory disturbance index was modestly increased by zolpidem although in all but one subject it remained < 5 with both treatments. 4. Zolpidem intake did not impair daytime vigilance and performance evaluated the day after. PMID:7917771

  4. Difundindo saberes da vigilância sanitária

    Directory of Open Access Journals (Sweden)

    André Luís Gemal

    2013-05-01

    Full Text Available É com enorme prazer que anunciamos o segundo número da revista Vigilância Sanitária em Debate: Sociedade, Ciência & Tecnologia. Nesta edição contamos com valiosas contribuições autorais, ao mesmo tempo em que inauguramos a seção de resenhas, com a descrição crítica do livro Sistemas de Salud en Suramérica: desafios para la universalidad, la integralidad y la equidad (2012, elaborado pelo Instituto Suramericano de Gobierno en Salud (Isags/Unasur e organizado por Ligia Giovanella, Oscar Feo, Mariana Faria e Sebastián Tobar.

  5. Effect of Acute, Subacute, and Repeated Exposure to High Altitude (5050 m on Psychomotor Vigilance

    Directory of Open Access Journals (Sweden)

    Matiram Pun

    2018-06-01

    Full Text Available Aim: High altitude (HA hypoxia may affect cognitive performance and sleep quality. Further, vigilance is reduced following sleep deprivation. We investigated the effect on vigilance, actigraphic sleep indices, and their relationships with acute mountain sickness (AMS during very HA exposure, acclimatization, and re-exposure.Methods: A total of 21 healthy altitude-naive individuals (25 ± 4 years; 13 females completed 2 cycles of altitude exposure separated by 7 days at low altitude (LA, 520 m. Participants slept at 2900 m and spent the day at HA, (5050 m. We report acute altitude exposure on Day 1 (LA vs. HA1 and after 6 days of acclimatization (HA1 vs. HA6. Vigilance was quantified by reaction speed in the 10-min psychomotor vigilance test reaction speed (PVT-RS. AMS was evaluated using the Environmental Symptoms Questionnaire Cerebral Score (AMS-C score. Nocturnal rest/activity was recorded to estimate sleep duration using actigraphy.Results: In Cycle 1, PVT-RS was slower at HA1 compared to LA (4.1 ± 0.8 vs. 4.5 ± 0.6 s-1, respectively, p = 0.029, but not at HA6 (4.6 ± 0.7; p > 0.05. In Cycle 2, PVT-RS at HA1 (4.6 ± 0.7 and HA6 (4.8 ± 0.6 were not different from LA (4.8 ± 0.6, p > 0.05 and significantly greater than corresponding values in Cycle 1. In both cycles, AMS scores were higher at HA1 than at LA and HA6 (p < 0.05. Estimated sleep durations (TST at LA, 1st and 5th nights were 431.3 ± 28.7, 418.1 ± 48.6, and 379.7 ± 51.4 min, respectively, in Cycle 1 and they were significantly reduced during acclimatization exposures (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.012; and 1st vs. 5th night, p = 0.054. LA, 1st and 5th nights TST in Cycle 2 were 477.5 ± 96.9, 430.9 ± 34, and 341.4 ± 32.2, respectively, and we observed similar deteriorations in TST as in Cycle 1 (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.001; and 1st vs. 5th night, p < 0.0001. At HA1, subjects who reported higher AMS-C scores exhibited slower

  6. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

    Science.gov (United States)

    Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A

    2015-03-01

    The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. The study was conducted in an academic research vivarium. Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

  7. Classifying vulnerability to sleep deprivation using baseline measures of psychomotor vigilance.

    Science.gov (United States)

    Patanaik, Amiya; Kwoh, Chee Keong; Chua, Eric C P; Gooley, Joshua J; Chee, Michael W L

    2015-05-01

    To identify measures derived from baseline psychomotor vigilance task (PVT) performance that can reliably predict vulnerability to sleep deprivation. Subjects underwent total sleep deprivation and completed a 10-min PVT every 1-2 h in a controlled laboratory setting. Participants were categorized as vulnerable or resistant to sleep deprivation, based on a median split of lapses that occurred following sleep deprivation. Standard reaction time, drift diffusion model (DDM), and wavelet metrics were derived from PVT response times collected at baseline. A support vector machine model that incorporated maximum relevance and minimum redundancy feature selection and wrapper-based heuristics was used to classify subjects as vulnerable or resistant using rested data. Two academic sleep laboratories. Independent samples of 135 (69 women, age 18 to 25 y), and 45 (3 women, age 22 to 32 y) healthy adults. In both datasets, DDM measures, number of consecutive reaction times that differ by more than 250 ms, and two wavelet features were selected by the model as features predictive of vulnerability to sleep deprivation. Using the best set of features selected in each dataset, classification accuracy was 77% and 82% using fivefold stratified cross-validation, respectively. In both datasets, DDM measures, number of consecutive reaction times that differ by more than 250 ms, and two wavelet features were selected by the model as features predictive of vulnerability to sleep deprivation. Using the best set of features selected in each dataset, classification accuracy was 77% and 82% using fivefold stratified cross-validation, respectively. Despite differences in experimental conditions across studies, drift diffusion model parameters associated reliably with individual differences in performance during total sleep deprivation. These results demonstrate the utility of drift diffusion modeling of baseline performance in estimating vulnerability to psychomotor vigilance decline

  8. Local hypothesis testing between a pure bipartite state and the white noise state

    OpenAIRE

    Owari, Masaki; Hayashi, Masahito

    2010-01-01

    In this paper, we treat a local discrimination problem in the framework of asymmetric hypothesis testing. We choose a known bipartite pure state $\\ket{\\Psi}$ as an alternative hypothesis, and the completely mixed state as a null hypothesis. As a result, we analytically derive an optimal type 2 error and an optimal POVM for one-way LOCC POVM and Separable POVM. For two-way LOCC POVM, we study a family of simple three-step LOCC protocols, and show that the best protocol in this family has stric...

  9. Does the Vigilance-Avoidance Gazing Behavior of Children with Separation Anxiety Disorder Change after Cognitive-Behavioral Therapy?

    Science.gov (United States)

    In-Albon, Tina; Schneider, Silvia

    2012-01-01

    Cognitive biases are of interest in understanding the development of anxiety disorders. They also play a significant role during psychotherapy, where cognitive biases are modified in order to break the vicious cycle responsible for maintaining anxiety disorders. In a previous study, the vigilance-avoidance pattern was shown in children with…

  10. Reinforcement Enhances Vigilance Among Children With ADHD: Comparisons to Typically Developing Children and to the Effects of Methylphenidate

    Science.gov (United States)

    Bubnik, Michelle G.; Hawk, Larry W.; Pelham, William E.; Waxmonsky, James G.; Rosch, Keri S.

    2014-01-01

    Sustained attention and reinforcement are posited as causal mechanisms in Attention-Deficit/Hyperactivity Disorder (ADHD), but their interaction has received little empirical study. In two studies, we examined the impact of performance-based reinforcement on sustained attention over time, or vigilance, among 9- to 12-year-old children. Study 1 demonstrated the expected vigilance deficit among children with ADHD (n=25; 12% female) compared to typically developing (TD) controls (n=33; 22% female) on a standard continuous performance task (CPT). During a subsequent visit, reinforcement improved attention more among children with ADHD than controls. Study 2 examined the separate and combined effects of reinforcement and acute methylphenidate (MPH) on CPT performance in children with ADHD (n=19; 21% female). Both reinforcement and MPH enhanced overall target detection and attenuated the vigilance decrement that occurred in no-reinforcement, placebo condition. Cross-study comparisons suggested that the combination of MPH and reinforcement eliminated the vigilance deficit in children with ADHD, normalizing sustained attention. This work highlights the clinically and theoretically interesting intersection of reinforcement and sustained attention. PMID:24931776

  11. Design of a Fatigue Detection System for High-Speed Trains Based on Driver Vigilance Using a Wireless Wearable EEG

    Directory of Open Access Journals (Sweden)

    Xiaoliang Zhang

    2017-03-01

    Full Text Available The vigilance of the driver is important for railway safety, despite not being included in the safety management system (SMS for high-speed train safety. In this paper, a novel fatigue detection system for high-speed train safety based on monitoring train driver vigilance using a wireless wearable electroencephalograph (EEG is presented. This system is designed to detect whether the driver is drowsiness. The proposed system consists of three main parts: (1 a wireless wearable EEG collection; (2 train driver vigilance detection; and (3 early warning device for train driver. In the first part, an 8-channel wireless wearable brain-computer interface (BCI device acquires the locomotive driver’s brain EEG signal comfortably under high-speed train-driving conditions. The recorded data are transmitted to a personal computer (PC via Bluetooth. In the second step, a support vector machine (SVM classification algorithm is implemented to determine the vigilance level using the Fast Fourier transform (FFT to extract the EEG power spectrum density (PSD. In addition, an early warning device begins to work if fatigue is detected. The simulation and test results demonstrate the feasibility of the proposed fatigue detection system for high-speed train safety.

  12. Moonlight avoidance in gerbils reveals a sophisticated interplay among time allocation, vigilance and state-dependent foraging.

    Science.gov (United States)

    Kotler, Burt P; Brown, Joel; Mukherjee, Shomen; Berger-Tal, Oded; Bouskila, Amos

    2010-05-22

    Foraging animals have several tools for managing the risk of predation, and the foraging games between them and their predators. Among these, time allocation is foremost, followed by vigilance and apprehension. Together, their use influences a forager's time allocation and giving-up density (GUD) in depletable resource patches. We examined Allenby's gerbils (Gerbilus andersoni allenbyi) exploiting seed resource patches in a large vivarium under varying moon phases in the presence of a red fox (Vulpes vulpes). We measured time allocated to foraging patches electronically and GUDs from seeds left behind in resource patches. From these, we estimated handling times, attack rates and quitting harvest rates (QHRs). Gerbils displayed greater vigilance (lower attack rates) at brighter moon phases (full full > new > wane). Finally, gerbils displayed higher QHRs at new and waxing moon phases. Differences across moon phases not only reflect changing time allocation and vigilance, but changes in the state of the foragers and their marginal value of energy. Early in the lunar cycle, gerbils rely on vigilance and sacrifice state to avoid risk; later they defend state at the cost of increased time allocation; finally their state can recover as safe opportunities expand. In the predator-prey foraging game, foxes may contribute to these patterns of behaviours by modulating their own activity in response to the opportunities presented in each moon phase.

  13. Time-on-task impairment of psychomotor vigilance is affected by mild skin warming and changes with aging and insomnia

    NARCIS (Netherlands)

    Raymann, R.J.E.M.; Someren, E.J. van

    2007-01-01

    Study Objectives: To investigate the effect of mild manipulations of core and skin temperature on psychomotor vigilance (PVT) in young adults, elderly, and elderly insomniacs. Design: 432 PVTs were obtained during a 2-day semi-constant routine protocol, while differentially manipulating core and

  14. Hypothesis Testing in the Real World

    Science.gov (United States)

    Miller, Jeff

    2017-01-01

    Critics of null hypothesis significance testing suggest that (a) its basic logic is invalid and (b) it addresses a question that is of no interest. In contrast to (a), I argue that the underlying logic of hypothesis testing is actually extremely straightforward and compelling. To substantiate that, I present examples showing that hypothesis…

  15. Error probabilities in default Bayesian hypothesis testing

    NARCIS (Netherlands)

    Gu, Xin; Hoijtink, Herbert; Mulder, J,

    2016-01-01

    This paper investigates the classical type I and type II error probabilities of default Bayes factors for a Bayesian t test. Default Bayes factors quantify the relative evidence between the null hypothesis and the unrestricted alternative hypothesis without needing to specify prior distributions for

  16. Reassessing the Trade-off Hypothesis

    DEFF Research Database (Denmark)

    Rosas, Guillermo; Manzetti, Luigi

    2015-01-01

    Do economic conditions drive voters to punish politicians that tolerate corruption? Previous scholarly work contends that citizens in young democracies support corrupt governments that are capable of promoting good economic outcomes, the so-called trade-off hypothesis. We test this hypothesis based...

  17. Mastery Learning and the Decreasing Variability Hypothesis.

    Science.gov (United States)

    Livingston, Jennifer A.; Gentile, J. Ronald

    1996-01-01

    This report results from studies that tested two variations of Bloom's decreasing variability hypothesis using performance on successive units of achievement in four graduate classrooms that used mastery learning procedures. Data do not support the decreasing variability hypothesis; rather, they show no change over time. (SM)

  18. Hypothesis driven development of new adjuvants: short peptides as immunomodulators.

    Science.gov (United States)

    Dong, Jessica C; Kobinger, Gary P

    2013-04-01

    To date, vaccinations have been one of the key strategies in the prevention and protection against infectious pathogens. Traditional vaccines have well-known limitations such as safety and efficacy issues, which consequently deems it inappropriate for particular populations and may not be an effective strategy against all pathogens. This evidence highlights the need to develop more efficacious vaccination regiments. Higher levels of protection can be achieved by the addition of immunostimulating adjuvants. Many adjuvants elicit strong, undefined inflammation, which produces increased immunogenicity but may also lead to undesirable effects. Hypothesis driven development of adjuvants is needed to achieve a more specific and directed immune response required for optimal and safe vaccine-induced immune protection. An example of such hypothesis driven development includes the use of short immunomodulating peptides as adjuvants. These peptides have the ability to influence the immune response and can be extrapolated for adjuvant use, but requires further investigation.

  19. Vigilance in the laboratory predicts avoidance in the real world: A dimensional analysis of neural, behavioral, and ecological momentary data in anxious youth

    Directory of Open Access Journals (Sweden)

    Rebecca B. Price

    2016-06-01

    Full Text Available Vigilance and avoidance of threat are observed in anxious adults during laboratory tasks, and are posited to have real-world clinical relevance, but data are mixed in anxious youth. We propose that vigilance-avoidance patterns will become evident in anxious youth through a focus on individual differences and real-world strategic avoidance. Decreased functional connectivity between the amygdala and prefrontal cortex (PFC could play a mechanistic role in this link. 78 clinically anxious youth completed a dot-probe task to assess vigilance to threat while undergoing fMRI. Real-world avoidance was assessed using Ecological Momentary Assessment (EMA of self-reported suppression and distraction during negative life events. Vigilance toward threat was positively associated with EMA distraction and suppression. Functional connectivity between a right amygdala seed region and dorsomedial and right dorsolateral PFC regions was inversely related to EMA distraction. Dorsolateral PFC-amygdalar connectivity statistically mediated the relationship between attentional vigilance and real-world distraction. Findings suggest anxious youth showing attentional vigilance toward threat are more likely to use suppression and distraction to regulate negative emotions. Reduced PFC control over limbic reactivity is a possible neural substrate of this pattern. These findings lend ecological validity to laboratory vigilance assessments and suggest PFC-amygdalar connectivity is a neural mechanism bridging laboratory and naturalistic contexts.

  20. Implications of the Bohm-Aharonov hypothesis

    International Nuclear Information System (INIS)

    Ghirardi, G.C.; Rimini, A.; Weber, T.

    1976-01-01

    It is proved that the Bohm-Aharonov hypothesis concerning largerly separated subsystems of composite quantum systems implies that it is impossible to express the dynamical evolution in terms of the density operator

  1. Multi-agent sequential hypothesis testing

    KAUST Repository

    Kim, Kwang-Ki K.; Shamma, Jeff S.

    2014-01-01

    incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well

  2. The (not so) Immortal Strand Hypothesis

    OpenAIRE

    Tomasetti, Cristian; Bozic, Ivana

    2015-01-01

    Background: Non-random segregation of DNA strands during stem cell replication has been proposed as a mechanism to minimize accumulated genetic errors in stem cells of rapidly dividing tissues. According to this hypothesis, an “immortal” DNA strand is passed to the stem cell daughter and not the more differentiated cell, keeping the stem cell lineage replication error-free. After it was introduced, experimental evidence both in favor and against the hypothesis has been presented. Principal...

  3. The scent of wolves: pyrazine analogs induce avoidance and vigilance behaviors in prey

    Directory of Open Access Journals (Sweden)

    Kazumi eOsada

    2015-10-01

    Full Text Available The common grey wolf (Canis lupus is an apex predator located at the top of the food chain in the Northern Hemisphere. It preys on rodents, rabbits, ungulates, and many other kinds of mammal. However, the behavioral evidence for, and the chemical basis of, the fear-inducing impact of wolf urine on prey are unclear. Recently, the pyrazine analogs 2, 6-dimethylpyrazine, 2, 3, 5-trimethylpyrazine and 3-ethyl-2, 5-dimethyl pyrazine were identified as kairomones in the urine of wolves. When mice were confronted with a mixture of purified pyrazine analogs, vigilance behaviors, including freezing and excitation of neurons at the accessory olfactory bulb, were markedly increased. Additionally, the odor of the pyrazine cocktail effectively suppressed the approach of deer to a feeding area, and for those close to the feeding area elicited fear-related behaviors such as the tail-flag, flight, and jump actions. In this review, we discuss the transfer of chemical information from wolf to prey through the novel kairomones identified in wolf urine and also compare the characteristics of wolf kairomones with other predator-produced kairomones that affect rodents.

  4. Drugs and dilated cardiomyopathies: A case/noncase study in the French PharmacoVigilance Database.

    Science.gov (United States)

    Montastruc, Guillaume; Favreliere, Sylvie; Sommet, Agnès; Pathak, Atul; Lapeyre-Mestre, Maryse; Perault-Pochat, Marie-Christine; Montastruc, Jean-Louis

    2010-03-01

    To evaluate putative associations between drugs and dilated cardiomyopathy. We used the case/noncase method in the French PharmacoVigilance Database (FPVD). Cases were all the observations with dilated cardiomyopathy registered into the FPVD between 1 January 1990 and 30 June 2007. Noncases were all other reports other than those studied. Anthracyclines were used as positive controls. Data were expressed as reporting odds ratio (ROR) with their 95% confidence intervals. Out of the 258 729 adverse drug reaction (ADR) reports recorded in the FPVD between 1 January 1990 and 30 June 2007, 47 (22 men, mean age 49 years) were defined as dilated cardiomyopathy. In these 47 patients, 67 drugs were 'suspect'. A significant ROR was found with cytotoxic (epirubicin, mitoxantrone, cyclophosphamide, gemcitabine, fluorouracil) and antiretroviral (lamividune, zidovudine, abacavir) but also with isotretinoin, prednisone, appetite suppressant (clobenzorex) and psychotropic [antipsychotic (clozapine, olanzapine), lithium, antidepressant (clomipramine, amitriptyline, fluvoxamine)] drugs. The present study describes an association between some drugs and reports of dilated cardiomyopathies. This relationship involves not only some already suspected drugs (anthracyclines, antiretrovirals), but also other drugs (antipsychotics, lithium, antidepressants, retinoids) less known to induce such an ADR. Despite the mandatory limits of this kind of study (underreporting, confounding factors . . .), these data represent a pharmacovigilance signal and could contribute to establish further prospective studies in order to confirm such signals.

  5. Anaphylaxis to diclofenac: nine cases reported to the Allergy Vigilance Network in France.

    Science.gov (United States)

    Picaud, J; Beaudouin, E; Renaudin, J M; Pirson, F; Metz-Favre, C; Dron-Gonzalvez, M; Moneret-Vautrin, D A

    2014-10-01

    Nine cases of diclofenac hypersensitivity recorded by the Allergy Vigilance Network in France from 2002 to 2012 were studied. Data from history, symptoms, skin tests, basophil activation tests, and oral challenge (OC) were recorded. Grade 3 severe anaphylactic reactions occurred in seven cases of nine. IgE-dependent anaphylaxis was confirmed in six cases: positive intradermal tests (n = 4), a syndromic reaction during skin tests (n = 1), and one case with grade 1 reaction and negative skin tests had an anaphylactic shock to the OC. A nonimmune reaction was suspected in one case. An IgE-dependent mechanism may be the predominant cause of adverse reactions to diclofenac. Allergy skin tests must be carried out sequentially at the recommended concentrations. BATs may be helpful because they can support the diagnosis of anaphylaxis. Given the risks of a direct challenge to diclofenac, OC to aspirin should be performed first to exclude a nonimmunologic hypersensitivity to NSAIDs. Tests for specific IgEs to most frequently used NSAIDs such as diclofenac and ibuprofen are urgently needed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Intra-abdominal hypertension and abdominal compartment syndrome in association with ruptured abdominal aortic aneurysm in the endovascular era: vigilance remains critical.

    Science.gov (United States)

    Bozeman, Matthew C; Ross, Charles B

    2012-01-01

    Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are common complications of ruptured abdominal aortoiliac aneurysms (rAAAs) and other abdominal vascular catastrophes even in the age of endovascular therapy. Morbidity and mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF) are significant. Recognition and management of IAH are key critical care measures which may decrease morbidity and improve survival in these vascular patients. Two strategies have been utilized: expectant management with prompt decompressive laparotomy upon diagnosis of threshold levels of IAH versus prophylactic, delayed abdominal closure based upon clinical parameters at the time of initial repair. Competent management of the abdominal wound with preservation of abdominal domain is also an important component of the care of these patients. In this review, we describe published experience with IAH and ACS complicating abdominal vascular catastrophes, experience with ACS complicating endovascular repair of rAAAs, and techniques for management of the abdominal wound. Vigilance and appropriate management of IAH and ACS remains critically important in decreasing morbidity and optimizing survival following catastrophic intra-abdominal vascular events.

  7. Short-term serotonergic but not noradrenergic antidepressant administration reduces attentional vigilance to threat in healthy volunteers

    OpenAIRE

    Murphy, Susannah E; Yiend, Jenny; Lester, Kathryn J; Cowen, Philip J; Harmer, Catherine J

    2009-01-01

    Anxiety is associated with threat-related biases in information processing such as heightened attentional vigilance to potential threat. Such biases are an important focus of psychological treatments for anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of a range of anxiety disorders. The aim of this study was to assess the effect of an SSRI on the processing of threat in healthy volunteers. A selective noradrenergic reuptake inhibitor (SNRI), ...

  8. Vigilância em Saúde Mental e Trabalho no Brasil: características, dificuldades e desafios

    Directory of Open Access Journals (Sweden)

    Tania Maria Araújo

    Full Text Available Resumo Este artigo aborda as dificuldades e os desafios da Vigilância em Saúde Mental Relacionada ao Trabalho (SMRT no Brasil, com base em levantamento de produção bibliográfica. Busca-se, a partir da compilação da produção identificada, fomentar reflexões sobre o panorama atual em que se encontram as ações em Vigilância nesse campo, seus principais entraves e possibilidades de avanços. Efetuou-se levantamento de publicações nacionais nas bases do Scielo, Lilacs e PubMed, de 2002 a 2017. A sistematização dos dados permitiu a sua estruturação nas seguintes temáticas: Epidemiologia da SMRT no Brasil; Políticas para a SMRT e a VISAT; Organização do Trabalho e Saúde Mental; e, Ações e Intervenções em VISAT e SMRT. As ações para Vigilância encontram-se, ainda, em estado incipiente, porém há esforços para o fortalecimento da RENAST, materializado na construção de protocolos e na promoção de encontros nacionais que visam à reflexão e à construção de um novo modelo de Vigilância em Saúde do Trabalhador. Registra-se a busca por novos modelos e concepções de adoecimento mental, de redefinição do foco de atenção, de modos de intervenção com destaque para o papel ativo dos trabalhadores, protagonistas imprescindíveis ao enfrentamento dos desafios nesse campo.

  9. Independent component analysis in non-hypothesis driven metabolomics

    DEFF Research Database (Denmark)

    Li, Xiang; Hansen, Jakob; Zhao, Xinjie

    2012-01-01

    In a non-hypothesis driven metabolomics approach plasma samples collected at six different time points (before, during and after an exercise bout) were analyzed by gas chromatography-time of flight mass spectrometry (GC-TOF MS). Since independent component analysis (ICA) does not need a priori...... information on the investigated process and moreover can separate statistically independent source signals with non-Gaussian distribution, we aimed to elucidate the analytical power of ICA for the metabolic pattern analysis and the identification of key metabolites in this exercise study. A novel approach...... based on descriptive statistics was established to optimize ICA model. In the GC-TOF MS data set the number of principal components after whitening and the number of independent components of ICA were optimized and systematically selected by descriptive statistics. The elucidated dominating independent...

  10. A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation.

    Science.gov (United States)

    Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

    2016-02-19

    In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver's EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver's vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

  11. A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation

    Directory of Open Access Journals (Sweden)

    Zutao Zhang

    2016-02-01

    Full Text Available In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI system with eight channels is designed for collecting the driver’s EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT is adopted to extract the EEG power spectrum density (PSD. In this step, sparse representation classification combined with k-singular value decomposition (KSVD is firstly introduced in PSD to estimate the driver’s vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

  12. The Use of Caffeine to Enhance Cognitive Performance, Reaction Time, Vigilance, Rifle Marksmanship and Mood States in Sleep-Deprived Navy SEAL (BUD/S) Trainees

    National Research Council Canada - National Science Library

    Tharion, William

    1997-01-01

    Caffeine has been shown to improve tasks with a vigilance component. The purpose of this study was to determine the effectiveness of caffeine in sleep-deprived individuals exposed to high levels of operational and environmental stress...

  13. Multiple hypothesis tracking for the cyber domain

    Science.gov (United States)

    Schwoegler, Stefan; Blackman, Sam; Holsopple, Jared; Hirsch, Michael J.

    2011-09-01

    This paper discusses how methods used for conventional multiple hypothesis tracking (MHT) can be extended to domain-agnostic tracking of entities from non-kinematic constraints such as those imposed by cyber attacks in a potentially dense false alarm background. MHT is widely recognized as the premier method to avoid corrupting tracks with spurious data in the kinematic domain but it has not been extensively applied to other problem domains. The traditional approach is to tightly couple track maintenance (prediction, gating, filtering, probabilistic pruning, and target confirmation) with hypothesis management (clustering, incompatibility maintenance, hypothesis formation, and Nassociation pruning). However, by separating the domain specific track maintenance portion from the domain agnostic hypothesis management piece, we can begin to apply the wealth of knowledge gained from ground and air tracking solutions to the cyber (and other) domains. These realizations led to the creation of Raytheon's Multiple Hypothesis Extensible Tracking Architecture (MHETA). In this paper, we showcase MHETA for the cyber domain, plugging in a well established method, CUBRC's INFormation Engine for Real-time Decision making, (INFERD), for the association portion of the MHT. The result is a CyberMHT. We demonstrate the power of MHETA-INFERD using simulated data. Using metrics from both the tracking and cyber domains, we show that while no tracker is perfect, by applying MHETA-INFERD, advanced nonkinematic tracks can be captured in an automated way, perform better than non-MHT approaches, and decrease analyst response time to cyber threats.

  14. Aminoglycoside antibiotics and autism: a speculative hypothesis

    Directory of Open Access Journals (Sweden)

    Manev Hari

    2001-10-01

    Full Text Available Abstract Background Recently, it has been suspected that there is a relationship between therapy with some antibiotics and the onset of autism; but even more curious, some children benefited transiently from a subsequent treatment with a different antibiotic. Here, we speculate how aminoglycoside antibiotics might be associated with autism. Presentation We hypothesize that aminoglycoside antibiotics could a trigger the autism syndrome in susceptible infants by causing the stop codon readthrough, i.e., a misreading of the genetic code of a hypothetical critical gene, and/or b improve autism symptoms by correcting the premature stop codon mutation in a hypothetical polymorphic gene linked to autism. Testing Investigate, retrospectively, whether a link exists between aminoglycoside use (which is not extensive in children and the onset of autism symptoms (hypothesis "a", or between amino glycoside use and improvement of these symptoms (hypothesis "b". Whereas a prospective study to test hypothesis "a" is not ethically justifiable, a study could be designed to test hypothesis "b". Implications It should be stressed that at this stage no direct evidence supports our speculative hypothesis and that its main purpose is to initiate development of new ideas that, eventually, would improve our understanding of the pathobiology of autism.

  15. Testing competing forms of the Milankovitch hypothesis

    DEFF Research Database (Denmark)

    Kaufmann, Robert K.; Juselius, Katarina

    2016-01-01

    We test competing forms of the Milankovitch hypothesis by estimating the coefficients and diagnostic statistics for a cointegrated vector autoregressive model that includes 10 climate variables and four exogenous variables for solar insolation. The estimates are consistent with the physical...... ice volume and solar insolation. The estimated adjustment dynamics show that solar insolation affects an array of climate variables other than ice volume, each at a unique rate. This implies that previous efforts to test the strong form of the Milankovitch hypothesis by examining the relationship...... that the latter is consistent with a weak form of the Milankovitch hypothesis and that it should be restated as follows: Internal climate dynamics impose perturbations on glacial cycles that are driven by solar insolation. Our results show that these perturbations are likely caused by slow adjustment between land...

  16. Rejecting the equilibrium-point hypothesis.

    Science.gov (United States)

    Gottlieb, G L

    1998-01-01

    The lambda version of the equilibrium-point (EP) hypothesis as developed by Feldman and colleagues has been widely used and cited with insufficient critical understanding. This article offers a small antidote to that lack. First, the hypothesis implicitly, unrealistically assumes identical transformations of lambda into muscle tension for antagonist muscles. Without that assumption, its definitions of command variables R, C, and lambda are incompatible and an EP is not defined exclusively by R nor is it unaffected by C. Second, the model assumes unrealistic and unphysiological parameters for the damping properties of the muscles and reflexes. Finally, the theory lacks rules for two of its three command variables. A theory of movement should offer insight into why we make movements the way we do and why we activate muscles in particular patterns. The EP hypothesis offers no unique ideas that are helpful in addressing either of these questions.

  17. The linear hypothesis and radiation carcinogenesis

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1981-10-01

    An assumption central to most estimations of the carcinogenic potential of low levels of ionising radiation is that the risk always increases in direct proportion to the dose received. This assumption (the linear hypothesis) has been both strongly defended and attacked on several counts. It appears unlikely that conclusive, direct evidence on the validity of the hypothesis will be forthcoming. We review the major indirect arguments used in the debate. All of them are subject to objections that can seriously weaken their case. In the present situation, retention of the linear hypothesis as the basis of extrapolations from high to low dose levels can lead to excessive fears, over-regulation and unnecessarily expensive protection measures. To offset these possibilities, support is given to suggestions urging a cut-off dose, probably some fraction of natural background, below which risks can be deemed acceptable

  18. Rayleigh's hypothesis and the geometrical optics limit.

    Science.gov (United States)

    Elfouhaily, Tanos; Hahn, Thomas

    2006-09-22

    The Rayleigh hypothesis (RH) is often invoked in the theoretical and numerical treatment of rough surface scattering in order to decouple the analytical form of the scattered field. The hypothesis stipulates that the scattered field away from the surface can be extended down onto the rough surface even though it is formed by solely up-going waves. Traditionally this hypothesis is systematically used to derive the Volterra series under the small perturbation method which is equivalent to the low-frequency limit. In this Letter we demonstrate that the RH also carries the high-frequency or the geometrical optics limit, at least to first order. This finding has never been explicitly derived in the literature. Our result comforts the idea that the RH might be an exact solution under some constraints in the general case of random rough surfaces and not only in the case of small-slope deterministic periodic gratings.

  19. Development of a Field-Deployable Psychomotor Vigilance Test to Monitor Helicopter Pilot Performance.

    Science.gov (United States)

    McMahon, Terry W; Newman, David G

    2016-04-01

    Flying a helicopter is a complex psychomotor skill. Fatigue is a serious threat to operational safety, particularly for sustained helicopter operations involving high levels of cognitive information processing and sustained time on task. As part of ongoing research into this issue, the object of this study was to develop a field-deployable helicopter-specific psychomotor vigilance test (PVT) for the purpose of daily performance monitoring of pilots. The PVT consists of a laptop computer, a hand-operated joystick, and a set of rudder pedals. Screen-based compensatory tracking task software includes a tracking ball (operated by the joystick) which moves randomly in all directions, and a second tracking ball which moves horizontally (operated by the rudder pedals). The 5-min test requires the pilot to keep both tracking balls centered. This helicopter-specific PVT's portability and integrated data acquisition and storage system enables daily field monitoring of the performance of individual helicopter pilots. The inclusion of a simultaneous foot-operated tracking task ensures divided attention for helicopter pilots as the movement of both tracking balls requires simultaneous inputs. This PVT is quick, economical, easy to use, and specific to the operational flying task. It can be used for performance monitoring purposes, and as a general research tool for investigating the psychomotor demands of helicopter operations. While reliability and validity testing is warranted, data acquired from this test could help further our understanding of the effect of various factors (such as fatigue) on helicopter pilot performance, with the potential of contributing to helicopter operational safety.

  20. AAVPG: A vigilant vector where transgene expression is induced by p53

    Energy Technology Data Exchange (ETDEWEB)

    Bajgelman, Marcio C.; Medrano, Ruan F.V.; Carvalho, Anna Carolina P.V.; Strauss, Bryan E., E-mail: bstrauss@usp.br

    2013-12-15

    Using p53 to drive transgene expression from viral vectors may provide on demand expression in response to physiologic stress, such as hypoxia or DNA damage. Here we introduce AAVPG, an adeno-associated viral (AAV) vector where a p53-responsive promoter, termed PG, is used to control transgene expression. In vitro assays show that expression from the AAVPG-luc vector was induced specifically in the presence of functional p53 (1038±202 fold increase, p<0.001). The AAVPG-luc vector was an effective biosensor of p53 activation in response to hypoxia (4.48±0.6 fold increase in the presence of 250 µM CoCl{sub 2}, p<0.001) and biomechanical stress (2.53±0.4 fold increase with stretching, p<0.05). In vivo, the vigilant nature of the AAVPG-luc vector was revealed after treatment of tumor-bearing mice with doxorubicin (pre-treatment, 3.4×10{sup 5}±0.43×10{sup 5} photons/s; post-treatment, 6.6×10{sup 5}±2.1×10{sup 5} photons/s, p<0.05). These results indicate that the AAVPG vector is an interesting option for detecting p53 activity both in vitro and in vivo. - Highlights: • AAV vector where transgene expression is controlled by the tumor suppressor p53. • The new vector, AAVPG, shown to function as a biosensor of p53 activity, in vitro and in vivo. • The p53 activity monitored by the AAVPG vector is relevant to cancer and other diseases. • AAVPG reporter gene expression was activated upon DNA damage, hypoxia and mechanical stress.

  1. On the generalized gravi-magnetic hypothesis

    International Nuclear Information System (INIS)

    Massa, C.

    1989-01-01

    According to a generalization of the gravi-magnetic hypothesis (GMH) any neutral mass moving in a curvilinear path with respect to an inertial frame creates a magnetic field, dependent on the curvature radius of the path. A simple astrophysical consequence of the generalized GMH is suggested considering the special cases of binary pulsars and binary neutron stars

  2. Remarks about the hypothesis of limiting fragmentation

    International Nuclear Information System (INIS)

    Chou, T.T.; Yang, C.N.

    1987-01-01

    Remarks are made about the hypothesis of limiting fragmentation. In particular, the concept of favored and disfavored fragment distribution is introduced. Also, a sum rule is proved leading to a useful quantity called energy-fragmentation fraction. (author). 11 refs, 1 fig., 2 tabs

  3. Multiple hypothesis clustering in radar plot extraction

    NARCIS (Netherlands)

    Huizing, A.G.; Theil, A.; Dorp, Ph. van; Ligthart, L.P.

    1995-01-01

    False plots and plots with inaccurate range and Doppler estimates may severely degrade the performance of tracking algorithms in radar systems. This paper describes how a multiple hypothesis clustering technique can be applied to mitigate the problems involved in plot extraction. The measures of

  4. The (not so immortal strand hypothesis

    Directory of Open Access Journals (Sweden)

    Cristian Tomasetti

    2015-03-01

    Significance: Utilizing an approach that is fundamentally different from previous efforts to confirm or refute the immortal strand hypothesis, we provide evidence against non-random segregation of DNA during stem cell replication. Our results strongly suggest that parental DNA is passed randomly to stem cell daughters and provides new insight into the mechanism of DNA replication in stem cells.

  5. A Developmental Study of the Infrahumanization Hypothesis

    Science.gov (United States)

    Martin, John; Bennett, Mark; Murray, Wayne S.

    2008-01-01

    Intergroup attitudes in children were examined based on Leyen's "infrahumanization hypothesis". This suggests that some uniquely human emotions, such as shame and guilt (secondary emotions), are reserved for the in-group, whilst other emotions that are not uniquely human and shared with animals, such as anger and pleasure (primary…

  6. Morbidity and Infant Development: A Hypothesis.

    Science.gov (United States)

    Pollitt, Ernesto

    1983-01-01

    Results of a study conducted in 14 villages of Sui Lin Township, Taiwan, suggest the hypothesis that, under conditions of extreme economic impoverishment and among children within populations where energy protein malnutrition is endemic, there is an inverse relationship between incidence of morbidity in infancy and measures of motor and mental…

  7. Diagnostic Hypothesis Generation and Human Judgment

    Science.gov (United States)

    Thomas, Rick P.; Dougherty, Michael R.; Sprenger, Amber M.; Harbison, J. Isaiah

    2008-01-01

    Diagnostic hypothesis-generation processes are ubiquitous in human reasoning. For example, clinicians generate disease hypotheses to explain symptoms and help guide treatment, auditors generate hypotheses for identifying sources of accounting errors, and laypeople generate hypotheses to explain patterns of information (i.e., data) in the…

  8. Multi-hypothesis distributed stereo video coding

    DEFF Research Database (Denmark)

    Salmistraro, Matteo; Zamarin, Marco; Forchhammer, Søren

    2013-01-01

    for stereo sequences, exploiting an interpolated intra-view SI and two inter-view SIs. The quality of the SI has a major impact on the DVC Rate-Distortion (RD) performance. As the inter-view SIs individually present lower RD performance compared with the intra-view SI, we propose multi-hypothesis decoding...

  9. [Resonance hypothesis of heart rate variability origin].

    Science.gov (United States)

    Sheĭkh-Zade, Iu R; Mukhambetaliev, G Kh; Cherednik, I L

    2009-09-01

    A hypothesis is advanced of the heart rate variability being subjected to beat-to-beat regulation of cardiac cycle duration in order to ensure the resonance interaction between respiratory and own fluctuation of the arterial system volume for minimization of power expenses of cardiorespiratory system. Myogenic, parasympathetic and sympathetic machanisms of heart rate variability are described.

  10. In Defense of Chi's Ontological Incompatibility Hypothesis

    Science.gov (United States)

    Slotta, James D.

    2011-01-01

    This article responds to an article by A. Gupta, D. Hammer, and E. F. Redish (2010) that asserts that M. T. H. Chi's (1992, 2005) hypothesis of an "ontological commitment" in conceptual development is fundamentally flawed. In this article, I argue that Chi's theoretical perspective is still very much intact and that the critique offered by Gupta…

  11. Vacuum counterexamples to the cosmic censorship hypothesis

    International Nuclear Information System (INIS)

    Miller, B.D.

    1981-01-01

    In cylindrically symmetric vacuum spacetimes it is possible to specify nonsingular initial conditions such that timelike singularities will (necessarily) evolve from these conditions. Examples are given; the spacetimes are somewhat analogous to one of the spherically symmetric counterexamples to the cosmic censorship hypothesis

  12. A novel hypothesis splitting method implementation for multi-hypothesis filters

    DEFF Research Database (Denmark)

    Bayramoglu, Enis; Ravn, Ole; Andersen, Nils Axel

    2013-01-01

    The paper presents a multi-hypothesis filter library featuring a novel method for splitting Gaussians into ones with smaller variances. The library is written in C++ for high performance and the source code is open and free1. The multi-hypothesis filters commonly approximate the distribution tran...

  13. The Income Inequality Hypothesis Revisited : Assessing the Hypothesis Using Four Methodological Approaches

    NARCIS (Netherlands)

    Kragten, N.; Rözer, J.

    The income inequality hypothesis states that income inequality has a negative effect on individual’s health, partially because it reduces social trust. This article aims to critically assess the income inequality hypothesis by comparing several analytical strategies, namely OLS regression,

  14. Einstein's Revolutionary Light-Quantum Hypothesis

    Science.gov (United States)

    Stuewer, Roger H.

    2005-05-01

    The paper in which Albert Einstein proposed his light-quantum hypothesis was the only one of his great papers of 1905 that he himself termed ``revolutionary.'' Contrary to widespread belief, Einstein did not propose his light-quantum hypothesis ``to explain the photoelectric effect.'' Instead, he based his argument for light quanta on the statistical interpretation of the second law of thermodynamics, with the photoelectric effect being only one of three phenomena that he offered as possible experimental support for it. I will discuss Einstein's light-quantum hypothesis of 1905 and his introduction of the wave-particle duality in 1909 and then turn to the reception of his work on light quanta by his contemporaries. We will examine the reasons that prominent physicists advanced to reject Einstein's light-quantum hypothesis in succeeding years. Those physicists included Robert A. Millikan, even though he provided convincing experimental proof of the validity of Einstein's equation of the photoelectric effect in 1915. The turning point came after Arthur Holly Compton discovered the Compton effect in late 1922, but even then Compton's discovery was contested both on experimental and on theoretical grounds. Niels Bohr, in particular, had never accepted the reality of light quanta and now, in 1924, proposed a theory, the Bohr-Kramers-Slater theory, which assumed that energy and momentum were conserved only statistically in microscopic interactions. Only after that theory was disproved experimentally in 1925 was Einstein's revolutionary light-quantum hypothesis generally accepted by physicists---a full two decades after Einstein had proposed it.

  15. A Dopamine Hypothesis of Autism Spectrum Disorder.

    Science.gov (United States)

    Pavăl, Denis

    2017-01-01

    Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders characterized by social deficits and stereotyped behaviors. While several theories have emerged, the pathogenesis of ASD remains unknown. Although studies report dopamine signaling abnormalities in autistic patients, a coherent dopamine hypothesis which could link neurobiology to behavior in ASD is currently lacking. In this paper, we present such a hypothesis by proposing that autistic behavior arises from dysfunctions in the midbrain dopaminergic system. We hypothesize that a dysfunction of the mesocorticolimbic circuit leads to social deficits, while a dysfunction of the nigrostriatal circuit leads to stereotyped behaviors. Furthermore, we discuss 2 key predictions of our hypothesis, with emphasis on clinical and therapeutic aspects. First, we argue that dopaminergic dysfunctions in the same circuits should associate with autistic-like behavior in nonautistic subjects. Concerning this, we discuss the case of PANDAS (pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections) which displays behaviors similar to those of ASD, presumed to arise from dopaminergic dysfunctions. Second, we argue that providing dopamine modulators to autistic subjects should lead to a behavioral improvement. Regarding this, we present clinical studies of dopamine antagonists which seem to have improving effects on autistic behavior. Furthermore, we explore the means of testing our hypothesis by using neuroreceptor imaging, which could provide comprehensive evidence for dopamine signaling dysfunctions in autistic subjects. Lastly, we discuss the limitations of our hypothesis. Along these lines, we aim to provide a dopaminergic model of ASD which might lead to a better understanding of the ASD pathogenesis. © 2017 S. Karger AG, Basel.

  16. A Bayesian Decision-Theoretic Approach to Logically-Consistent Hypothesis Testing

    Directory of Open Access Journals (Sweden)

    Gustavo Miranda da Silva

    2015-09-01

    Full Text Available This work addresses an important issue regarding the performance of simultaneous test procedures: the construction of multiple tests that at the same time are optimal from a statistical perspective and that also yield logically-consistent results that are easy to communicate to practitioners of statistical methods. For instance, if hypothesis A implies hypothesis B, is it possible to create optimal testing procedures that reject A whenever they reject B? Unfortunately, several standard testing procedures fail in having such logical consistency. Although this has been deeply investigated under a frequentist perspective, the literature lacks analyses under a Bayesian paradigm. In this work, we contribute to the discussion by investigating three rational relationships under a Bayesian decision-theoretic standpoint: coherence, invertibility and union consonance. We characterize and illustrate through simple examples optimal Bayes tests that fulfill each of these requisites separately. We also explore how far one can go by putting these requirements together. We show that although fairly intuitive tests satisfy both coherence and invertibility, no Bayesian testing scheme meets the desiderata as a whole, strengthening the understanding that logical consistency cannot be combined with statistical optimality in general. Finally, we associate Bayesian hypothesis testing with Bayes point estimation procedures. We prove the performance of logically-consistent hypothesis testing by means of a Bayes point estimator to be optimal only under very restrictive conditions.

  17. La vigilance des enseignant-e-s d’éducation physique et sportive relative à l’égalité des filles et des garçons Physical education teachers' vigilance towards gender equity

    Directory of Open Access Journals (Sweden)

    Geneviève Cogerino

    2011-10-01

    Full Text Available Les recherches en Éducation Physique et Sportive (EPS montrent des enseignant-e-s très majoritairement favorables à la mixité, mais elles mettent à jour des mécanismes discriminatoires laissant supposer que ces dernier(es seraient sans conscience des inégalités qu’ils/elles provoquent. Le choix d’une étude s’appuyant sur la psychophénoménologie permet de documenter les logiques intrinsèques à l’origine des discriminations : 24 entretiens d’explicitation ont été réalisés auprès d’enseignant-e-s d’EPS afin de leur faire décrire leurs expériences vécues de cours mixtes. Nos résultats montrent que la mixité est toujours subjectivement située : sa forme, choisie par l’enseignant-e, implique en retour des décisions de justice ainsi qu’une vigilance plus ou moins forte du point de vue de l’équité sexuée. Deux études de cas permettront d’illustrer les facteurs subjectifs qui jouent sur cette vigilance.Researches show that physical education (PE teachers are overwhelmingly in favor of coeducation. But they update discriminatory mechanisms suggesting that they are unaware of the inequities they cause. A study based on psychophenomenology allows to document the intrinsic logics behind discrimination: 24 explanatory interviews were carried out with PE teachers to let them describe their lived experiences in coeducational classes. Our results show that coeducation is always subjectively located: its form, chosen by the teacher, calls in return for justice decisions and for a more or less strong vigilance concerning gender equity. Two case studies illustrate the subjective factors that influence alertness toward the gender equity.

  18. Tests of the Giant Impact Hypothesis

    Science.gov (United States)

    Jones, J. H.

    1998-01-01

    The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

  19. The discovered preference hypothesis - an empirical test

    DEFF Research Database (Denmark)

    Lundhede, Thomas; Ladenburg, Jacob; Olsen, Søren Bøye

    Using stated preference methods for valuation of non-market goods is known to be vulnerable to a range of biases. Some authors claim that these so-called anomalies in effect render the methods useless for the purpose. However, the Discovered Preference Hypothesis, as put forth by Plott [31], offers...... an nterpretation and explanation of biases which entails that the stated preference methods need not to be completely written off. In this paper we conduct a test for the validity and relevance of the DPH interpretation of biases. In a choice experiment concerning preferences for protection of Danish nature areas...... as respondents evaluate more and more choice sets. This finding supports the Discovered Preference Hypothesis interpretation and explanation of starting point bias....

  20. The Hypothesis-Driven Physical Examination.

    Science.gov (United States)

    Garibaldi, Brian T; Olson, Andrew P J

    2018-05-01

    The physical examination remains a vital part of the clinical encounter. However, physical examination skills have declined in recent years, in part because of decreased time at the bedside. Many clinicians question the relevance of physical examinations in the age of technology. A hypothesis-driven approach to teaching and practicing the physical examination emphasizes the performance of maneuvers that can alter the likelihood of disease. Likelihood ratios are diagnostic weights that allow clinicians to estimate the post-probability of disease. This hypothesis-driven approach to the physical examination increases its value and efficiency, while preserving its cultural role in the patient-physician relationship. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. MOLIERE: Automatic Biomedical Hypothesis Generation System.

    Science.gov (United States)

    Sybrandt, Justin; Shtutman, Michael; Safro, Ilya

    2017-08-01

    Hypothesis generation is becoming a crucial time-saving technique which allows biomedical researchers to quickly discover implicit connections between important concepts. Typically, these systems operate on domain-specific fractions of public medical data. MOLIERE, in contrast, utilizes information from over 24.5 million documents. At the heart of our approach lies a multi-modal and multi-relational network of biomedical objects extracted from several heterogeneous datasets from the National Center for Biotechnology Information (NCBI). These objects include but are not limited to scientific papers, keywords, genes, proteins, diseases, and diagnoses. We model hypotheses using Latent Dirichlet Allocation applied on abstracts found near shortest paths discovered within this network, and demonstrate the effectiveness of MOLIERE by performing hypothesis generation on historical data. Our network, implementation, and resulting data are all publicly available for the broad scientific community.

  2. The Method of Hypothesis in Plato's Philosophy

    Directory of Open Access Journals (Sweden)

    Malihe Aboie Mehrizi

    2016-09-01

    Full Text Available The article deals with the examination of method of hypothesis in Plato's philosophy. This method, respectively, will be examined in three dialogues of Meno, Phaedon and Republic in which it is explicitly indicated. It will be shown the process of change of Plato’s attitude towards the position and usage of the method of hypothesis in his realm of philosophy. In Meno, considering the geometry, Plato attempts to introduce a method that can be used in the realm of philosophy. But, ultimately in Republic, Plato’s special attention to the method and its importance in the philosophical investigations, leads him to revise it. Here, finally Plato introduces the particular method of philosophy, i.e., the dialectic

  3. Debates—Hypothesis testing in hydrology: Introduction

    Science.gov (United States)

    Blöschl, Günter

    2017-03-01

    This paper introduces the papers in the "Debates—Hypothesis testing in hydrology" series. The four articles in the series discuss whether and how the process of testing hypotheses leads to progress in hydrology. Repeated experiments with controlled boundary conditions are rarely feasible in hydrology. Research is therefore not easily aligned with the classical scientific method of testing hypotheses. Hypotheses in hydrology are often enshrined in computer models which are tested against observed data. Testability may be limited due to model complexity and data uncertainty. All four articles suggest that hypothesis testing has contributed to progress in hydrology and is needed in the future. However, the procedure is usually not as systematic as the philosophy of science suggests. A greater emphasis on a creative reasoning process on the basis of clues and explorative analyses is therefore needed.

  4. Multi-agent sequential hypothesis testing

    KAUST Repository

    Kim, Kwang-Ki K.

    2014-12-15

    This paper considers multi-agent sequential hypothesis testing and presents a framework for strategic learning in sequential games with explicit consideration of both temporal and spatial coordination. The associated Bayes risk functions explicitly incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well-defined value functions with respect to (a) the belief states for the case of conditional independent private noisy measurements that are also assumed to be independent identically distributed over time, and (b) the information states for the case of correlated private noisy measurements. A sequential investment game of strategic coordination and delay is also discussed as an application of the proposed strategic learning rules.

  5. Hypothesis testing of scientific Monte Carlo calculations

    Science.gov (United States)

    Wallerberger, Markus; Gull, Emanuel

    2017-11-01

    The steadily increasing size of scientific Monte Carlo simulations and the desire for robust, correct, and reproducible results necessitates rigorous testing procedures for scientific simulations in order to detect numerical problems and programming bugs. However, the testing paradigms developed for deterministic algorithms have proven to be ill suited for stochastic algorithms. In this paper we demonstrate explicitly how the technique of statistical hypothesis testing, which is in wide use in other fields of science, can be used to devise automatic and reliable tests for Monte Carlo methods, and we show that these tests are able to detect some of the common problems encountered in stochastic scientific simulations. We argue that hypothesis testing should become part of the standard testing toolkit for scientific simulations.

  6. Exploring heterogeneous market hypothesis using realized volatility

    Science.gov (United States)

    Chin, Wen Cheong; Isa, Zaidi; Mohd Nor, Abu Hassan Shaari

    2013-04-01

    This study investigates the heterogeneous market hypothesis using high frequency data. The cascaded heterogeneous trading activities with different time durations are modelled by the heterogeneous autoregressive framework. The empirical study indicated the presence of long memory behaviour and predictability elements in the financial time series which supported heterogeneous market hypothesis. Besides the common sum-of-square intraday realized volatility, we also advocated two power variation realized volatilities in forecast evaluation and risk measurement in order to overcome the possible abrupt jumps during the credit crisis. Finally, the empirical results are used in determining the market risk using the value-at-risk approach. The findings of this study have implications for informationally market efficiency analysis, portfolio strategies and risk managements.

  7. Water Taxation and the Double Dividend Hypothesis

    OpenAIRE

    Nicholas Kilimani

    2014-01-01

    The double dividend hypothesis contends that environmental taxes have the potential to yield multiple benefits for the economy. However, empirical evidence of the potential impacts of environmental taxation in developing countries is still limited. This paper seeks to contribute to the literature by exploring the impact of a water tax in a developing country context, with Uganda as a case study. Policy makers in Uganda are exploring ways of raising revenue by taxing environmental goods such a...

  8. [Working memory, phonological awareness and spelling hypothesis].

    Science.gov (United States)

    Gindri, Gigiane; Keske-Soares, Márcia; Mota, Helena Bolli

    2007-01-01

    Working memory, phonological awareness and spelling hypothesis. To verify the relationship between working memory, phonological awareness and spelling hypothesis in pre-school children and first graders. Participants of this study were 90 students, belonging to state schools, who presented typical linguistic development. Forty students were preschoolers, with the average age of six and 50 students were first graders, with the average age of seven. Participants were submitted to an evaluation of the working memory abilities based on the Working Memory Model (Baddeley, 2000), involving phonological loop. Phonological loop was evaluated using the Auditory Sequential Test, subtest 5 of Illinois Test of Psycholinguistic Abilities (ITPA), Brazilian version (Bogossian & Santos, 1977), and the Meaningless Words Memory Test (Kessler, 1997). Phonological awareness abilities were investigated using the Phonological Awareness: Instrument of Sequential Assessment (CONFIAS - Moojen et al., 2003), involving syllabic and phonemic awareness tasks. Writing was characterized according to Ferreiro & Teberosky (1999). Preschoolers presented the ability of repeating sequences of 4.80 digits and 4.30 syllables. Regarding phonological awareness, the performance in the syllabic level was of 19.68 and in the phonemic level was of 8.58. Most of the preschoolers demonstrated to have a pre-syllabic writing hypothesis. First graders repeated, in average, sequences of 5.06 digits and 4.56 syllables. These children presented a phonological awareness of 31.12 in the syllabic level and of 16.18 in the phonemic level, and demonstrated to have an alphabetic writing hypothesis. The performance of working memory, phonological awareness and spelling level are inter-related, as well as being related to chronological age, development and scholarity.

  9. Box-particle probability hypothesis density filtering

    OpenAIRE

    Schikora, M.; Gning, A.; Mihaylova, L.; Cremers, D.; Koch, W.

    2014-01-01

    This paper develops a novel approach for multitarget tracking, called box-particle probability hypothesis density filter (box-PHD filter). The approach is able to track multiple targets and estimates the unknown number of targets. Furthermore, it is capable of dealing with three sources of uncertainty: stochastic, set-theoretic, and data association uncertainty. The box-PHD filter reduces the number of particles significantly, which improves the runtime considerably. The small number of box-p...

  10. Quantum effects and hypothesis of cosmic censorship

    International Nuclear Information System (INIS)

    Parnovskij, S.L.

    1989-01-01

    It is shown that filamentary characteristics with linear mass of less than 10 25 g/cm distort slightly the space-time at distances, exceeding Planck ones. Their formation doesn't change vacuum energy and doesn't lead to strong quantum radiation. Therefore, the problem of their occurrence can be considered within the framework of classical collapse. Quantum effects can be ignored when considering the problem of validity of cosmic censorship hypothesis

  11. Time-on-task decrement in vigilance is modulated by inter-individual vulnerability to homeostatic sleep pressure manipulation

    Directory of Open Access Journals (Sweden)

    Micheline eMaire

    2014-03-01

    Full Text Available Under sleep loss, vigilance is reduced and attentional failures emerge progressively. It becomes difficult to maintain stable performance over time, leading to growing performance variability (i.e. state instability in an individual and among subjects. Task duration plays a major role in the maintenance of stable vigilance levels, such that the longer the task, the more likely state instability will be observed. Vulnerability to sleep-loss-dependent performance decrements is highly individual and is also modulated by a polymorphism in the human clock gene PERIOD3 (PER3. By combining two different protocols, we manipulated sleep-wake history by once extending wakefulness for 40 h (high sleep pressure condition and once by imposing a short sleep-wake cycle by alternating 160 min of wakefulness and 80 min naps (low sleep pressure condition in a within-subject design. We observed that homozygous carriers of the long repeat allele of PER3 (PER35/5 experienced a greater time-on-task dependent performance decrement (i.e., a steeper increase in the number of lapses in the Psychomotor Vigilance Task compared to the carriers of the short repeat allele (PER34/4. These genotype-dependent effects disappeared under low sleep pressure conditions, and neither motivation, nor perceived effort accounted for these differences. Our data thus suggest that greater sleep-loss related attentional vulnerability based on the PER3 polymorphism is mirrored by a greater state instability under extended wakefulness in the short compared to the long allele carriers. Our results undermine the importance of time-on-task related aspects when investigating inter-individual differences in sleep loss-induced behavioural vulnerability.

  12. The (not so) immortal strand hypothesis.

    Science.gov (United States)

    Tomasetti, Cristian; Bozic, Ivana

    2015-03-01

    Non-random segregation of DNA strands during stem cell replication has been proposed as a mechanism to minimize accumulated genetic errors in stem cells of rapidly dividing tissues. According to this hypothesis, an "immortal" DNA strand is passed to the stem cell daughter and not the more differentiated cell, keeping the stem cell lineage replication error-free. After it was introduced, experimental evidence both in favor and against the hypothesis has been presented. Using a novel methodology that utilizes cancer sequencing data we are able to estimate the rate of accumulation of mutations in healthy stem cells of the colon, blood and head and neck tissues. We find that in these tissues mutations in stem cells accumulate at rates strikingly similar to those expected without the protection from the immortal strand mechanism. Utilizing an approach that is fundamentally different from previous efforts to confirm or refute the immortal strand hypothesis, we provide evidence against non-random segregation of DNA during stem cell replication. Our results strongly suggest that parental DNA is passed randomly to stem cell daughters and provides new insight into the mechanism of DNA replication in stem cells. Copyright © 2015. Published by Elsevier B.V.

  13. A test of the orthographic recoding hypothesis

    Science.gov (United States)

    Gaygen, Daniel E.

    2003-04-01

    The Orthographic Recoding Hypothesis [D. E. Gaygen and P. A. Luce, Percept. Psychophys. 60, 465-483 (1998)] was tested. According to this hypothesis, listeners recognize spoken words heard for the first time by mapping them onto stored representations of the orthographic forms of the words. Listeners have a stable orthographic representation of words, but no phonological representation, when those words have been read frequently but never heard or spoken. Such may be the case for low frequency words such as jargon. Three experiments using visually and auditorily presented nonword stimuli tested this hypothesis. The first two experiments were explicit tests of memory (old-new tests) for words presented visually. In the first experiment, the recognition of auditorily presented nonwords was facilitated when they previously appeared on a visually presented list. The second experiment was similar, but included a concurrent articulation task during a visual word list presentation, thus preventing covert rehearsal of the nonwords. The results were similar to the first experiment. The third experiment was an indirect test of memory (auditory lexical decision task) for visually presented nonwords. Auditorily presented nonwords were identified as nonwords significantly more slowly if they had previously appeared on the visually presented list accompanied by a concurrent articulation task.

  14. Consumer health information seeking as hypothesis testing.

    Science.gov (United States)

    Keselman, Alla; Browne, Allen C; Kaufman, David R

    2008-01-01

    Despite the proliferation of consumer health sites, lay individuals often experience difficulty finding health information online. The present study attempts to understand users' information seeking difficulties by drawing on a hypothesis testing explanatory framework. It also addresses the role of user competencies and their interaction with internet resources. Twenty participants were interviewed about their understanding of a hypothetical scenario about a family member suffering from stable angina and then searched MedlinePlus consumer health information portal for information on the problem presented in the scenario. Participants' understanding of heart disease was analyzed via semantic analysis. Thematic coding was used to describe information seeking trajectories in terms of three key strategies: verification of the primary hypothesis, narrowing search within the general hypothesis area and bottom-up search. Compared to an expert model, participants' understanding of heart disease involved different key concepts, which were also differently grouped and defined. This understanding provided the framework for search-guiding hypotheses and results interpretation. Incorrect or imprecise domain knowledge led individuals to search for information on irrelevant sites, often seeking out data to confirm their incorrect initial hypotheses. Online search skills enhanced search efficiency, but did not eliminate these difficulties. Regardless of their web experience and general search skills, lay individuals may experience difficulty with health information searches. These difficulties may be related to formulating and evaluating hypotheses that are rooted in their domain knowledge. Informatics can provide support at the levels of health information portals, individual websites, and consumer education tools.

  15. Programa de Educação para o Trabalho e Vigilância em Saúde

    Directory of Open Access Journals (Sweden)

    Maria Socorro Carneiro Linhares

    Full Text Available As iniciativas nacionais que se propõem contribuir para a reorientação da formação e do modelo de atenção nos levaram a descrever a experiência de implantação do Programa de Educação para o Trabalho (PET-Saúde/Vigilância em Saúde (VS em Sobral, Ceará. Trata-se de estudo descritivo, do tipo relato de experiência, vivenciado por estudantes dos cursos de enfermagem da Universidade Estadual Vale do Acaraú (UVA e medicina e odontologia da Universidade Federal do Ceará (UFC, tutores e preceptores do PET-Saúde/VS. As informações foram registradas pelos tutores e preceptores durante as atividades desenvolvidas desde a implantação do programa (julho de 2010. O processo de trabalho desempenhado no PET-Saúde/VS compreende três eixos estruturantes que se intercomunicam, constando vivências teórico-conceituais, vivências no serviço e vivências de pesquisa. Para garantir a interface ensino-serviço e a integração entre as ações de vigilância em saúde e atenção básica, construímos uma 'tecnologia' pedagógica que chamamos de tecnologia de educação permanente na vigilância em saúde. A experiência permitiu aos estudantes uma visão mais ampla, acerca das condições de saúde da população, da importância do conhecimento sobre problemas locais para o trabalho da vigilância em saúde, a fim de prestar assistência qualificada e voltada para a realidade de cada território.

  16. How organisms do the right thing: The attractor hypothesis

    Science.gov (United States)

    Emlen, J.M.; Freeman, D.C.; Mills, A.; Graham, J.H.

    1998-01-01

    Neo-Darwinian theory is highly successful at explaining the emergence of adaptive traits over successive generations. However, there are reasons to doubt its efficacy in explaining the observed, impressively detailed adaptive responses of organisms to day-to-day changes in their surroundings. Also, the theory lacks a clear mechanism to account for both plasticity and canalization. In effect, there is a growing sentiment that the neo-Darwinian paradigm is incomplete, that something more than genetic structure, mutation, genetic drift, and the action of natural selection is required to explain organismal behavior. In this paper we extend the view of organisms as complex self-organizing entities by arguing that basic physical laws, coupled with the acquisitive nature of organisms, makes adaptation all but tautological. That is, much adaptation is an unavoidable emergent property of organisms' complexity and, to some a significant degree, occurs quite independently of genomic changes wrought by natural selection. For reasons that will become obvious, we refer to this assertion as the attractor hypothesis. The arguments also clarify the concept of "adaptation." Adaptation across generations, by natural selection, equates to the (game theoretic) maximization of fitness (the success with which one individual produces more individuals), while self-organizing based adaptation, within generations, equates to energetic efficiency and the matching of intake and biosynthesis to need. Finally, we discuss implications of the attractor hypothesis for a wide variety of genetical and physiological phenomena, including genetic architecture, directed mutation, genetic imprinting, paramutation, hormesis, plasticity, optimality theory, genotype-phenotype linkage and puncuated equilibrium, and present suggestions for tests of the hypothesis. ?? 1998 American Institute of Physics.

  17. An algorithm for testing the efficient market hypothesis.

    Directory of Open Access Journals (Sweden)

    Ioana-Andreea Boboc

    Full Text Available The objective of this research is to examine the efficiency of EUR/USD market through the application of a trading system. The system uses a genetic algorithm based on technical analysis indicators such as Exponential Moving Average (EMA, Moving Average Convergence Divergence (MACD, Relative Strength Index (RSI and Filter that gives buying and selling recommendations to investors. The algorithm optimizes the strategies by dynamically searching for parameters that improve profitability in the training period. The best sets of rules are then applied on the testing period. The results show inconsistency in finding a set of trading rules that performs well in both periods. Strategies that achieve very good returns in the training period show difficulty in returning positive results in the testing period, this being consistent with the efficient market hypothesis (EMH.

  18. An algorithm for testing the efficient market hypothesis.

    Science.gov (United States)

    Boboc, Ioana-Andreea; Dinică, Mihai-Cristian

    2013-01-01

    The objective of this research is to examine the efficiency of EUR/USD market through the application of a trading system. The system uses a genetic algorithm based on technical analysis indicators such as Exponential Moving Average (EMA), Moving Average Convergence Divergence (MACD), Relative Strength Index (RSI) and Filter that gives buying and selling recommendations to investors. The algorithm optimizes the strategies by dynamically searching for parameters that improve profitability in the training period. The best sets of rules are then applied on the testing period. The results show inconsistency in finding a set of trading rules that performs well in both periods. Strategies that achieve very good returns in the training period show difficulty in returning positive results in the testing period, this being consistent with the efficient market hypothesis (EMH).

  19. On the need of objective vigilance monitoring: Effects of sleep loss on target detection and task-negative activity using combined EEG/fMRI

    Directory of Open Access Journals (Sweden)

    Michael eCzisch

    2012-04-01

    Full Text Available Sleep loss affects attention by reducing levels of arousal and alertness. The neural mechanisms underlying the compensatory efforts of the brain to maintain attention and performance after sleep deprivation are not fully understood. Previous neuroimaging studies of sleep deprivation have not been able to exclude the effects of reduced arousal and vigilance when examining cerebral responses to cognitive challenges. Here, we used a simultaneous electroencephalography (EEG and functional magnetic resonance imaging (fMRI approach to study the effects of 36 hours of total sleep deprivation (TSD. Specifically, we focused on changes in selective attention processes as induced by an active acoustic oddball task, with the ability to isolate runs with objective EEG signs of high or reduced vigilance. At high vigilance, task-related activity appears to be sustained by compensatory co-activation of insular regions, but task-negative activity in the right posterior node of the default mode network is altered following TSD. When EEG shows signs of reduced vigilance, task-positive activity was massively impaired, but task-negative activation was showing levels comparable with the control condition after a well-rested night. Our results suggest that loss of strict anti-correlation between task-positive and task-negative activation reflects the effects of TSD, while the actual state of vigilance and task performance either affects task-related or task-negative activity.

  20. Updating the lamellar hypothesis of hippocampal organization

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    Robert S Sloviter

    2012-12-01

    Full Text Available In 1971, Andersen and colleagues proposed that excitatory activity in the entorhinal cortex propagates topographically to the dentate gyrus, and on through a trisynaptic circuit lying within transverse hippocampal slices or lamellae [Andersen, Bliss, and Skrede. 1971. Lamellar organization of hippocampal pathways. Exp Brain Res 13, 222-238]. In this way, a relatively simple structure might mediate complex functions in a manner analogous to the way independent piano keys can produce a nearly infinite variety of unique outputs. The lamellar hypothesis derives primary support from the lamellar distribution of dentate granule cell axons (the mossy fibers, which innervate dentate hilar neurons and area CA3 pyramidal cells and interneurons within the confines of a thin transverse hippocampal segment. Following the initial formulation of the lamellar hypothesis, anatomical studies revealed that unlike granule cells, hilar mossy cells, CA3 pyramidal cells, and Layer II entorhinal cells all form axonal projections that are more divergent along the longitudinal axis than the clearly lamellar mossy fiber pathway. The existence of pathways with translamellar distribution patterns has been interpreted, incorrectly in our view, as justifying outright rejection of the lamellar hypothesis [Amaral and Witter. 1989. The three-dimensional organization of the hippocampal formation: a review of anatomical data. Neuroscience 31, 571-591]. We suggest that the functional implications of longitudinally-projecting axons depend not on whether they exist, but on what they do. The observation that focal granule cell layer discharges normally inhibit, rather than excite, distant granule cells suggests that longitudinal axons in the dentate gyrus may mediate "lateral" inhibition and define lamellar function, rather than undermine it. In this review, we attempt a reconsideration of the evidence that most directly impacts the physiological concept of hippocampal lamellar

  1. Hypothesis Testing as an Act of Rationality

    Science.gov (United States)

    Nearing, Grey

    2017-04-01

    Statistical hypothesis testing is ad hoc in two ways. First, setting probabilistic rejection criteria is, as Neyman (1957) put it, an act of will rather than an act of rationality. Second, physical theories like conservation laws do not inherently admit probabilistic predictions, and so we must use what are called epistemic bridge principles to connect model predictions with the actual methods of hypothesis testing. In practice, these bridge principles are likelihood functions, error functions, or performance metrics. I propose that the reason we are faced with these problems is because we have historically failed to account for a fundamental component of basic logic - namely the portion of logic that explains how epistemic states evolve in the presence of empirical data. This component of Cox' (1946) calculitic logic is called information theory (Knuth, 2005), and adding information theory our hypothetico-deductive account of science yields straightforward solutions to both of the above problems. This also yields a straightforward method for dealing with Popper's (1963) problem of verisimilitude by facilitating a quantitative approach to measuring process isomorphism. In practice, this involves data assimilation. Finally, information theory allows us to reliably bound measures of epistemic uncertainty, thereby avoiding the problem of Bayesian incoherency under misspecified priors (Grünwald, 2006). I therefore propose solutions to four of the fundamental problems inherent in both hypothetico-deductive and/or Bayesian hypothesis testing. - Neyman (1957) Inductive Behavior as a Basic Concept of Philosophy of Science. - Cox (1946) Probability, Frequency and Reasonable Expectation. - Knuth (2005) Lattice Duality: The Origin of Probability and Entropy. - Grünwald (2006). Bayesian Inconsistency under Misspecification. - Popper (1963) Conjectures and Refutations: The Growth of Scientific Knowledge.

  2. The conscious access hypothesis: Explaining the consciousness.

    Science.gov (United States)

    Prakash, Ravi

    2008-01-01

    The phenomenon of conscious awareness or consciousness is complicated but fascinating. Although this concept has intrigued the mankind since antiquity, exploration of consciousness from scientific perspectives is not very old. Among myriad of theories regarding nature, functions and mechanism of consciousness, off late, cognitive theories have received wider acceptance. One of the most exciting hypotheses in recent times has been the "conscious access hypotheses" based on the "global workspace model of consciousness". It underscores an important property of consciousness, the global access of information in cerebral cortex. Present article reviews the "conscious access hypothesis" in terms of its theoretical underpinnings as well as experimental supports it has received.

  3. Interstellar colonization and the zoo hypothesis

    International Nuclear Information System (INIS)

    Jones, E.M.

    1978-01-01

    Michael Hart and others have pointed out that current estimates of the number of technological civilizations arisen in the Galaxy since its formation is in fundamental conflict with the expectation that such a civilization could colonize and utilize the entire Galaxy in 10 to 20 million years. This dilemma can be called Hart's paradox. Resolution of the paradox requires that one or more of the following are true: we are the Galaxy's first technical civilization; interstellar travel is immensely impractical or simply impossible; technological civilizations are very short-lived; or we inhabit a wildnerness preserve. The latter is the zoo hypothesis

  4. RANDOM WALK HYPOTHESIS IN FINANCIAL MARKETS

    Directory of Open Access Journals (Sweden)

    Nicolae-Marius JULA

    2017-05-01

    Full Text Available Random walk hypothesis states that the stock market prices do not follow a predictable trajectory, but are simply random. If you are trying to predict a random set of data, one should test for randomness, because, despite the power and complexity of the used models, the results cannot be trustworthy. There are several methods for testing these hypotheses and the use of computational power provided by the R environment makes the work of the researcher easier and with a cost-effective approach. The increasing power of computing and the continuous development of econometric tests should give the potential investors new tools in selecting commodities and investing in efficient markets.

  5. Confluence Model or Resource Dilution Hypothesis?

    DEFF Research Database (Denmark)

    Jæger, Mads

    have a negative effect on educational attainment most studies cannot distinguish empirically between the CM and the RDH. In this paper, I use the different theoretical predictions in the CM and the RDH on the role of cognitive ability as a partial or complete mediator of the sibship size effect......Studies on family background often explain the negative effect of sibship size on educational attainment by one of two theories: the Confluence Model (CM) or the Resource Dilution Hypothesis (RDH). However, as both theories – for substantively different reasons – predict that sibship size should...

  6. Set theory and the continuum hypothesis

    CERN Document Server

    Cohen, Paul J

    2008-01-01

    This exploration of a notorious mathematical problem is the work of the man who discovered the solution. The independence of the continuum hypothesis is the focus of this study by Paul J. Cohen. It presents not only an accessible technical explanation of the author's landmark proof but also a fine introduction to mathematical logic. An emeritus professor of mathematics at Stanford University, Dr. Cohen won two of the most prestigious awards in mathematics: in 1964, he was awarded the American Mathematical Society's Bôcher Prize for analysis; and in 1966, he received the Fields Medal for Logic.

  7. Statistical hypothesis testing with SAS and R

    CERN Document Server

    Taeger, Dirk

    2014-01-01

    A comprehensive guide to statistical hypothesis testing with examples in SAS and R When analyzing datasets the following questions often arise:Is there a short hand procedure for a statistical test available in SAS or R?If so, how do I use it?If not, how do I program the test myself? This book answers these questions and provides an overview of the most commonstatistical test problems in a comprehensive way, making it easy to find and performan appropriate statistical test. A general summary of statistical test theory is presented, along with a basicdescription for each test, including the

  8. Health anxiety and attentional bias: the time course of vigilance and avoidance in light of pictorial illness information.

    Science.gov (United States)

    Jasper, Fabian; Witthöft, Michael

    2011-12-01

    Cognitive-behavioral models of health anxiety stress the importance of selective attention not only towards internal but also towards external health threat related stimuli. Yet, little is known about the time course of this attentional bias. The current study investigates threat related attentional bias in participants with varying degrees of health anxiety. Attentional bias was assessed using a visual dot-probe task with health-threat and neutral pictures at two exposure durations, 175ms and 500ms. A baseline condition was added to the dot-probe task to dissociate indices of vigilance towards threat and difficulties to disengage from threat. Substantial positive correlations of health anxiety, anxiety sensitivity, and absorption with difficulties to disengage from threat were detected at 500ms exposure time. At an early stage (i.e., at 175ms exposure time), we found significant positive correlations of health anxiety and absorption with orientation towards threat. Results suggest a vigilance avoidance pattern of selective attention associated with pictorial illness related stimuli in health anxiety. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Los liberalismos de José María Vigil y Antonio Caso y el realismo directo

    Directory of Open Access Journals (Sweden)

    José Hernández

    2013-11-01

    Full Text Available Jose Maria Vigil (1829-1909 and Antonio Caso (1883-1946 were two defenders of liberal democracy and of the possibility of a limited but effective conscious management of public and social affairs, within the adverse contexts of Mexico during the administration of Porfirio Diaz as well as the post-revolutionary period. Both authors based their positions on a critique concerning positivism and social-historical determinism, which would aim at a way of thinking quite distant from subjectivist thought, although very close to an epistemological "direct realism" that establishes that the world is not actually a subjective or inter-subjective construction, that may be interpreted in the same subjective or inter-subjective way. However, it is not either something that might be known through a mental or conceptual copy or representation of its entities and processes. Perhaps, the most evocative defender of direct realism in history has been the 18* Century Scottish philosopher, Thomas Reid (1710-1796, a great "common-sensist", explicitly recovered by Vigil and vindicated in a tacit manner by Antonio Caso.

  10. The effect of chronotype on sleepiness, fatigue, and psychomotor vigilance of ICU nurses during the night shift.

    Science.gov (United States)

    Reinke, Laurens; Özbay, Yusuf; Dieperink, Willem; Tulleken, Jaap E

    2015-04-01

    In general, sleeping and activity patterns vary between individuals. This attribute, known as chronotype, may affect night shift performance. In the intensive care unit (ICR), night shift performance may impact patient safety. We have investigated the effect of chronotype and social demographics on sleepiness, fatigue, and night shift on the performance of nurses. This was a prospective observational cohort study which assessed the performance of 96 ICU night shift nurses during the day and night shifts in a mixed medical-surgical ICU in the Netherlands. We determined chronotype and assessed sleeping behaviour for each nurse prior to starting shift work and before free days. The level of sleepiness and fatigue of nurses during the day and night shifts was determined, as was the effect of these conditions on psychomotor vigilance and mathematical problem-solving. The majority of ICU nurses had a preference for early activity (morning chronotype). Compared to their counterparts (i.e. evening chronotypes), they were more likely to nap before commencing night shifts and more likely to have young children living at home. Despite increased sleepiness and fatigue during night shifts, no effect on psychomotor vigilance was observed during night shifts. Problem-solving accuracy remained high during night shifts, at the cost of productivity. Most of the ICU night shift nurses assessed here appeared to have adapted well to night shift work, despite the high percentage of morning chronotypes, possibly due to their 8-h shift duration. Parental responsibilities may, however, influence shift work tolerance.

  11. Short-term serotonergic but not noradrenergic antidepressant administration reduces attentional vigilance to threat in healthy volunteers.

    Science.gov (United States)

    Murphy, Susannah E; Yiend, Jenny; Lester, Kathryn J; Cowen, Philip J; Harmer, Catherine J

    2009-03-01

    Anxiety is associated with threat-related biases in information processing such as heightened attentional vigilance to potential threat. Such biases are an important focus of psychological treatments for anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of a range of anxiety disorders. The aim of this study was to assess the effect of an SSRI on the processing of threat in healthy volunteers. A selective noradrenergic reuptake inhibitor (SNRI), which is not generally used in the treatment of anxiety, was used as a contrast to assess the specificity of SSRI effects on threat processing. Forty-two healthy volunteers were randomly assigned to 7 d double-blind intervention with the SSRI citalopram (20 mg/d), the SNRI reboxetine (8 mg/d), or placebo. On the final day, attentional and interpretative bias to threat was assessed using the attentional probe and the homograph primed lexical decision tasks. Citalopram reduced attentional vigilance towards fearful faces but did not affect the interpretation of ambiguous homographs as threatening. Reboxetine had no significant effect on either of these measures. Citalopram reduces attentional orienting to threatening stimuli, which is potentially relevant to its clinical use in the treatment of anxiety disorders. This finding supports a growing literature suggesting that an important mechanism through which pharmacological agents may exert their effects on mood is by reversing the cognitive biases that characterize the disorders that they treat. Future studies are needed to clarify the neural mechanisms through which these effects on threat processing are mediated.

  12. Vigilance in industry: cosmetics and household cleaning products. Balance sheet of case report from 2005 to 2007.

    Science.gov (United States)

    Kornfeld-Lecanu, S; Zajaczkowski, F; Dubourg, S; Martin, L; Lefort, S; Siest, S

    2010-12-01

    Unlike medicinal products, cosmetics are not subject to marketing authorization in France. Nevertheless, the Agence Francaise de Sécurité Sanitaire des Produits de Santé (AFSSAPS; French Agency for the Safety of Healthcare Products) has been working on the development of a cosmetovigilance system for several years, with the aim of establishing standard procedures for collecting adverse reactions to cosmetics from the manufacturers. To assess the incidence of skin reactions to cosmetics or household products. Unilever established its own 'vigilance' standard system in France in late 2003. This report describes the experience acquired from 2005 to 2007. Case reports were collected in compliance with a standard procedure. The cases were then analysed by the consultant dermatologist in accordance with a pharmacovigilance-based method (chronological criteria, clinical criteria, possible rechallenge test, patch tests). During the period 2005 to 2007, a total of 102,689 consumers contacted the consumer department, including 842 (0.82%) who reported skin reactions. After analysis of the collected data, 0.144 skin reaction cases per million units sold were found to be attributable to cosmetic or household products. The implementation of a structured vigilance system in the cosmetics and household products industry is an efficient tool for manufacturers, both for information purposes and for product improvement, as well as meeting the transparency requirements of health authorities and consumers. © 2010 The Author(s). Journal compilation © 2010 British Association of Dermatologists.

  13. Hypothesis-driven physical examination curriculum.

    Science.gov (United States)

    Allen, Sharon; Olson, Andrew; Menk, Jeremiah; Nixon, James

    2017-12-01

    Medical students traditionally learn physical examination skills as a rote list of manoeuvres. Alternatives like hypothesis-driven physical examination (HDPE) may promote students' understanding of the contribution of physical examination to diagnostic reasoning. We sought to determine whether first-year medical students can effectively learn to perform a physical examination using an HDPE approach, and then tailor the examination to specific clinical scenarios. Medical students traditionally learn physical examination skills as a rote list of manoeuvres CONTEXT: First-year medical students at the University of Minnesota were taught both traditional and HDPE approaches during a required 17-week clinical skills course in their first semester. The end-of-course evaluation assessed HDPE skills: students were assigned one of two cardiopulmonary cases. Each case included two diagnostic hypotheses. During an interaction with a standardised patient, students were asked to select physical examination manoeuvres in order to make a final diagnosis. Items were weighted and selection order was recorded. First-year students with minimal pathophysiology performed well. All students selected the correct diagnosis. Importantly, students varied the order when selecting examination manoeuvres depending on the diagnoses under consideration, demonstrating early clinical decision-making skills. An early introduction to HDPE may reinforce physical examination skills for hypothesis generation and testing, and can foster early clinical decision-making skills. This has important implications for further research in physical examination instruction. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

  14. A default Bayesian hypothesis test for mediation.

    Science.gov (United States)

    Nuijten, Michèle B; Wetzels, Ruud; Matzke, Dora; Dolan, Conor V; Wagenmakers, Eric-Jan

    2015-03-01

    In order to quantify the relationship between multiple variables, researchers often carry out a mediation analysis. In such an analysis, a mediator (e.g., knowledge of a healthy diet) transmits the effect from an independent variable (e.g., classroom instruction on a healthy diet) to a dependent variable (e.g., consumption of fruits and vegetables). Almost all mediation analyses in psychology use frequentist estimation and hypothesis-testing techniques. A recent exception is Yuan and MacKinnon (Psychological Methods, 14, 301-322, 2009), who outlined a Bayesian parameter estimation procedure for mediation analysis. Here we complete the Bayesian alternative to frequentist mediation analysis by specifying a default Bayesian hypothesis test based on the Jeffreys-Zellner-Siow approach. We further extend this default Bayesian test by allowing a comparison to directional or one-sided alternatives, using Markov chain Monte Carlo techniques implemented in JAGS. All Bayesian tests are implemented in the R package BayesMed (Nuijten, Wetzels, Matzke, Dolan, & Wagenmakers, 2014).

  15. Gaussian Hypothesis Testing and Quantum Illumination.

    Science.gov (United States)

    Wilde, Mark M; Tomamichel, Marco; Lloyd, Seth; Berta, Mario

    2017-09-22

    Quantum hypothesis testing is one of the most basic tasks in quantum information theory and has fundamental links with quantum communication and estimation theory. In this paper, we establish a formula that characterizes the decay rate of the minimal type-II error probability in a quantum hypothesis test of two Gaussian states given a fixed constraint on the type-I error probability. This formula is a direct function of the mean vectors and covariance matrices of the quantum Gaussian states in question. We give an application to quantum illumination, which is the task of determining whether there is a low-reflectivity object embedded in a target region with a bright thermal-noise bath. For the asymmetric-error setting, we find that a quantum illumination transmitter can achieve an error probability exponent stronger than a coherent-state transmitter of the same mean photon number, and furthermore, that it requires far fewer trials to do so. This occurs when the background thermal noise is either low or bright, which means that a quantum advantage is even easier to witness than in the symmetric-error setting because it occurs for a larger range of parameters. Going forward from here, we expect our formula to have applications in settings well beyond those considered in this paper, especially to quantum communication tasks involving quantum Gaussian channels.

  16. Inoculation stress hypothesis of environmental enrichment.

    Science.gov (United States)

    Crofton, Elizabeth J; Zhang, Yafang; Green, Thomas A

    2015-02-01

    One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Athlete's Heart: Is the Morganroth Hypothesis Obsolete?

    Science.gov (United States)

    Haykowsky, Mark J; Samuel, T Jake; Nelson, Michael D; La Gerche, Andre

    2018-05-01

    In 1975, Morganroth and colleagues reported that the increased left ventricular (LV) mass in highly trained endurance athletes versus nonathletes was primarily due to increased end-diastolic volume while the increased LV mass in resistance trained athletes was solely due to an increased LV wall thickness. Based on the divergent remodelling patterns observed, Morganroth and colleagues hypothesised that the increased "volume" load during endurance exercise may be similar to that which occurs in patients with mitral or aortic regurgitation while the "pressure" load associated with performing a Valsalva manoeuvre (VM) during resistance exercise may mimic the stress imposed on the heart by systemic hypertension or aortic stenosis. Despite widespread acceptance of the four-decade old Morganroth hypothesis in sports cardiology, some investigators have questioned whether such a divergent "athlete's heart" phenotype exists. Given this uncertainty, the purpose of this brief review is to re-evaluate the Morganroth hypothesis regarding: i) the acute effects of resistance exercise performed with a brief VM on LV wall stress, and the patterns of LV remodelling in resistance-trained athletes; ii) the acute effects of endurance exercise on biventricular wall stress, and the time course and pattern of LV and right ventricular (RV) remodelling with endurance training; and iii) the value of comparing "loading" conditions between athletes and patients with cardiac pathology. Copyright © 2018. Published by Elsevier B.V.

  18. The Debt Overhang Hypothesis: Evidence from Pakistan

    Directory of Open Access Journals (Sweden)

    Shah Muhammad Imran

    2016-04-01

    Full Text Available This study investigates the debt overhang hypothesis for Pakistan in the period 1960-2007. The study examines empirically the dynamic behaviour of GDP, debt services, the employed labour force and investment using the time series concepts of unit roots, cointegration, error correlation and causality. Our findings suggest that debt-servicing has a negative impact on the productivity of both labour and capital, and that in turn has adversely affected economic growth. By severely constraining the ability of the country to service debt, this lends support to the debt-overhang hypothesis in Pakistan. The long run relation between debt services and economic growth implies that future increases in output will drain away in form of high debt service payments to lender country as external debt acts like a tax on output. More specifically, foreign creditors will benefit more from the rise in productivity than will domestic producers and labour. This suggests that domestic labour and capital are the ultimate losers from this heavy debt burden.

  19. Roots and Route of the Artification Hypothesis

    Directory of Open Access Journals (Sweden)

    Ellen Dissanayake

    2017-08-01

    Full Text Available Over four decades, my ideas about the arts in human evolution have themselves evolved, from an original notion of art as a human behaviour of “making special” to a full-fledged hypothesis of artification. A summary of the gradual developmental path (or route of the hypothesis, based on ethological principles and concepts, is given, and an argument presented in which artification is described as an exaptation whose roots lie in adaptive features of ancestral mother–infant interaction that contributed to infant survival and maternal reproductive success. I show how the interaction displays features of a ritualised behavior whose operations (formalization, repetition, exaggeration, and elaboration can be regarded as characteristic elements of human ritual ceremonies as well as of art (including song, dance, performance, literary language, altered surroundings, and other examples of making ordinary sounds, movement, language, environments, objects, and bodies extraordinary. Participation in these behaviours in ritual practices served adaptive ends in early Homo by coordinating brain and body states, and thereby emotionally bonding members of a group in common cause as well as reducing existential anxiety in individuals. A final section situates artification within contemporary philosophical and popular ideas of art, claiming that artifying is not a synonym for or definition of art but foundational to any evolutionary discussion of artistic/aesthetic behaviour.

  20. Hypothesis: does ochratoxin A cause testicular cancer?

    Science.gov (United States)

    Schwartz, Gary G

    2002-02-01

    Little is known about the etiology of testicular cancer, which is the most common cancer among young men. Epidemiologic data point to a carcinogenic exposure in early life or in utero, but the nature of the exposure is unknown. We hypothesize that the mycotoxin, ochratoxin A, is a cause of testicular cancer. Ochratoxin A is a naturally occurring contaminant of cereals, pigmeat, and other foods and is a known genotoxic carcinogen in animals. The major features of the descriptive epidemiology of testicular cancer (a high incidence in northern Europe, increasing incidence over time, and associations with high socioeconomic status, and with poor semen quality) are all associated with exposure to ochratoxin A. Exposure of animals to ochratoxin A via the diet or via in utero transfer induces adducts in testicular DNA. We hypothesize that consumption of foods contaminated with ochratoxin A during pregnancy and/or childhood induces lesions in testicular DNA and that puberty promotes these lesions to testicular cancer. We tested the ochratoxin A hypothesis using ecologic data on the per-capita consumption of cereals, coffee, and pigmeat, the principal dietary sources of ochratoxin A. Incidence rates for testicular cancer in 20 countries were significantly correlated with the per-capita consumption of coffee and pigmeat (r = 0.49 and 0.54, p = 0.03 and 0.01). The ochratoxin A hypothesis offers a coherent explanation for much of the descriptive epidemiology of testicular cancer and suggests new avenues for analytic research.

  1. Urbanization and the more-individuals hypothesis.

    Science.gov (United States)

    Chiari, Claudia; Dinetti, Marco; Licciardello, Cinzia; Licitra, Gaetano; Pautasso, Marco

    2010-03-01

    1. Urbanization is a landscape process affecting biodiversity world-wide. Despite many urban-rural studies of bird assemblages, it is still unclear whether more species-rich communities have more individuals, regardless of the level of urbanization. The more-individuals hypothesis assumes that species-rich communities have larger populations, thus reducing the chance of local extinctions. 2. Using newly collated avian distribution data for 1 km(2) grid cells across Florence, Italy, we show a significantly positive relationship between species richness and assemblage abundance for the whole urban area. This richness-abundance relationship persists for the 1 km(2) grid cells with less than 50% of urbanized territory, as well as for the remaining grid cells, with no significant difference in the slope of the relationship. These results support the more-individuals hypothesis as an explanation of patterns in species richness, also in human modified and fragmented habitats. 3. However, the intercept of the species richness-abundance relationship is significantly lower for highly urbanized grid cells. Our study confirms that urban communities have lower species richness but counters the common notion that assemblages in densely urbanized ecosystems have more individuals. In Florence, highly inhabited areas show fewer species and lower assemblage abundance. 4. Urbanized ecosystems are an ongoing large-scale natural experiment which can be used to test ecological theories empirically.

  2. The Younger Dryas impact hypothesis: A requiem

    Science.gov (United States)

    Pinter, Nicholas; Scott, Andrew C.; Daulton, Tyrone L.; Podoll, Andrew; Koeberl, Christian; Anderson, R. Scott; Ishman, Scott E.

    2011-06-01

    The Younger Dryas (YD) impact hypothesis is a recent theory that suggests that a cometary or meteoritic body or bodies hit and/or exploded over North America 12,900 years ago, causing the YD climate episode, extinction of Pleistocene megafauna, demise of the Clovis archeological culture, and a range of other effects. Since gaining widespread attention in 2007, substantial research has focused on testing the 12 main signatures presented as evidence of a catastrophic extraterrestrial event 12,900 years ago. Here we present a review of the impact hypothesis, including its evolution and current variants, and of efforts to test and corroborate the hypothesis. The physical evidence interpreted as signatures of an impact event can be separated into two groups. The first group consists of evidence that has been largely rejected by the scientific community and is no longer in widespread discussion, including: particle tracks in archeological chert; magnetic nodules in Pleistocene bones; impact origin of the Carolina Bays; and elevated concentrations of radioactivity, iridium, and fullerenes enriched in 3He. The second group consists of evidence that has been active in recent research and discussions: carbon spheres and elongates, magnetic grains and magnetic spherules, byproducts of catastrophic wildfire, and nanodiamonds. Over time, however, these signatures have also seen contrary evidence rather than support. Recent studies have shown that carbon spheres and elongates do not represent extraterrestrial carbon nor impact-induced megafires, but are indistinguishable from fungal sclerotia and arthropod fecal material that are a small but common component of many terrestrial deposits. Magnetic grains and spherules are heterogeneously distributed in sediments, but reported measurements of unique peaks in concentrations at the YD onset have yet to be reproduced. The magnetic grains are certainly just iron-rich detrital grains, whereas reported YD magnetic spherules are

  3. Acetylcholine Neuromodulation in Normal and Abnormal Learning and Memory: Vigilance Control in Waking, Sleep, Autism, Amnesia and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Stephen Grossberg

    2017-11-01

    Full Text Available Adaptive Resonance Theory, or ART, is a neural model that explains how normal and abnormal brains may learn to categorize and recognize objects and events in a changing world, and how these learned categories may be remembered for a long time. This article uses ART to propose and unify the explanation of diverse data about normal and abnormal modulation of learning and memory by acetylcholine (ACh. In ART, vigilance control determines whether learned categories will be general and abstract, or specific and concrete. ART models how vigilance may be regulated by ACh release in layer 5 neocortical cells by influencing after-hyperpolarization (AHP currents. This phasic ACh release is mediated by cells in the nucleus basalis (NB of Meynert that are activated by unexpected events. The article additionally discusses data about ACh-mediated tonic control of vigilance. ART proposes that there are often dynamic breakdowns of tonic control in mental disorders such as autism, where vigilance remains high, and medial temporal amnesia, where vigilance remains low. Tonic control also occurs during sleep-wake cycles. Properties of Up and Down states during slow wave sleep arise in ACh-modulated laminar cortical ART circuits that carry out processes in awake individuals of contrast normalization, attentional modulation, decision-making, activity-dependent habituation, and mismatch-mediated reset. These slow wave sleep circuits interact with circuits that control circadian rhythms and memory consolidation. Tonic control properties also clarify how Alzheimer’s disease symptoms follow from a massive structural degeneration that includes undermining vigilance control by ACh in cortical layers 3 and 5. Sleep disruptions before and during Alzheimer’s disease, and how they contribute to a vicious cycle of plaque formation in layers 3 and 5, are also clarified from this perspective.

  4. Approaches to informed consent for hypothesis-testing and hypothesis-generating clinical genomics research.

    Science.gov (United States)

    Facio, Flavia M; Sapp, Julie C; Linn, Amy; Biesecker, Leslie G

    2012-10-10

    Massively-parallel sequencing (MPS) technologies create challenges for informed consent of research participants given the enormous scale of the data and the wide range of potential results. We propose that the consent process in these studies be based on whether they use MPS to test a hypothesis or to generate hypotheses. To demonstrate the differences in these approaches to informed consent, we describe the consent processes for two MPS studies. The purpose of our hypothesis-testing study is to elucidate the etiology of rare phenotypes using MPS. The purpose of our hypothesis-generating study is to test the feasibility of using MPS to generate clinical hypotheses, and to approach the return of results as an experimental manipulation. Issues to consider in both designs include: volume and nature of the potential results, primary versus secondary results, return of individual results, duty to warn, length of interaction, target population, and privacy and confidentiality. The categorization of MPS studies as hypothesis-testing versus hypothesis-generating can help to clarify the issue of so-called incidental or secondary results for the consent process, and aid the communication of the research goals to study participants.

  5. Learning-Related Changes in Adolescents' Neural Networks during Hypothesis-Generating and Hypothesis-Understanding Training

    Science.gov (United States)

    Lee, Jun-Ki; Kwon, Yongju

    2012-01-01

    Fourteen science high school students participated in this study, which investigated neural-network plasticity associated with hypothesis-generating and hypothesis-understanding in learning. The students were divided into two groups and participated in either hypothesis-generating or hypothesis-understanding type learning programs, which were…

  6. Progress in violence risk assessment and communication: hypothesis versus evidence.

    Science.gov (United States)

    Harris, Grant T; Rice, Marnie E

    2015-02-01

    We draw a distinction between hypothesis and evidence with respect to the assessment and communication of the risk of violent recidivism. We suggest that some authorities in the field have proposed quite valid and reasonable hypotheses with respect to several issues. Among these are the following: that accuracy will be improved by the adjustment or moderation of numerical scores based on clinical opinions about rare risk factors or other considerations pertaining to the applicability to the case at hand; that there is something fundamentally distinct about protective factors so that they are not merely the obverse of risk factors, such that optimal accuracy cannot be achieved without consideration of such protective factors; and that assessment of dynamic factors is required for optimal accuracy and furthermore interventions aimed at such dynamic factors can be expected to cause reductions in violence risk. We suggest here that, while these are generally reasonable hypotheses, they have been inappropriately presented to practitioners as empirically supported facts, and that practitioners' assessment and communication about violence risk run beyond that supported by the available evidence as a result. We further suggest that this represents harm, especially in impeding scientific progress. Nothing here justifies stasis or simply surrendering to authoritarian custody with somatic treatment. Theoretically motivated and clearly articulated assessment and intervention should be provided for offenders, but in a manner that moves the field more firmly from hypotheses to evidence. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Noves aportacions a la vigilància, prevenció i control del VIH i d’altres infeccions de transmissió sexual a Catalunya

    OpenAIRE

    Carnicer-Pont, Dolors

    2015-01-01

    La vigilància de les malalties transmissibles ha evolucionat al llarg dels anys beneficiant-se dels desenvolupaments tecnològics tant pel que fa al laboratori com als sistemes d'informació. L'objectiu de tenir una visió més global de la realitat que permeti dirigir les actuacions per reduir la transmissió es va assolint gràcies a: 1) La triangulació de les dades procedents de diferents fonts d'informació com són les enquestes bio-conductuals, la vigilància sentinella per part d'un grup de met...

  8. Optimization and Optimal Control

    CERN Document Server

    Chinchuluun, Altannar; Enkhbat, Rentsen; Tseveendorj, Ider

    2010-01-01

    During the last four decades there has been a remarkable development in optimization and optimal control. Due to its wide variety of applications, many scientists and researchers have paid attention to fields of optimization and optimal control. A huge number of new theoretical, algorithmic, and computational results have been observed in the last few years. This book gives the latest advances, and due to the rapid development of these fields, there are no other recent publications on the same topics. Key features: Provides a collection of selected contributions giving a state-of-the-art accou

  9. Optimally Stopped Optimization

    Science.gov (United States)

    Vinci, Walter; Lidar, Daniel

    We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known, and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time, optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark the performance of a D-Wave 2X quantum annealer and the HFS solver, a specialized classical heuristic algorithm designed for low tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N = 1098 variables, the D-Wave device is between one to two orders of magnitude faster than the HFS solver.

  10. Alternatives to the linear risk hypothesis

    International Nuclear Information System (INIS)

    Craig, A.G.

    1976-01-01

    A theoretical argument is presented which suggests that in using the linear hypothesis for all values of LET the low dose risk is overestimated for low LET but that it is underestimated for very high LET. The argument is based upon the idea that cell lesions which do not lead to cell death may in fact lead to a malignant cell. Expressions for the Surviving Fraction and the Cancer Risk based on this argument are given. An advantage of this very general approach is that is expresses cell survival and cancer risk entirely in terms of the cell lesions and avoids the rather contentious argument as to how the average number of lesions should be related to the dose. (U.K.)

  11. Large numbers hypothesis. II - Electromagnetic radiation

    Science.gov (United States)

    Adams, P. J.

    1983-01-01

    This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

  12. Artistic talent in dyslexia--a hypothesis.

    Science.gov (United States)

    Chakravarty, Ambar

    2009-10-01

    The present article hints at a curious neurocognitive phenomenon of development of artistic talents in some children with dyslexia. The article also takes note of the phenomenon of creating in the midst of language disability as observed in the lives of such creative people like Leonardo da Vinci and Albert Einstein who were most probably affected with developmental learning disorders. It has been hypothesised that a developmental delay in the dominant hemisphere most likely 'disinhibits' the non-dominant parietal lobe to unmask talents, artistic or otherwise, in some such individuals. The present hypothesis follows the phenomenon of paradoxical functional facilitation described earlier. It has been suggested that children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to overemphasising on the correction of the disturbed coded symbol operations, in remedial training.

  13. Tissue misrepair hypothesis for radiation carcinogenesis

    International Nuclear Information System (INIS)

    Kondo, Sohei

    1991-01-01

    Dose-response curves for chronic leukemia in A-bomb survivors and liver tumors in patients given Thorotrast (colloidal thorium dioxide) show large threshold effects. The existence of these threshold effects can be explained by the following hypothesis. A high dose of radiation causes a persistent wound in a cellrenewable tissue. Disorder of the injured cell society partly frees the component cells from territorial restraints on their proliferation, enabling them to continue development of their cellular functions toward advanced autonomy. This progression might be achieved by continued epigenetic and genetic changes as a result of occasional errors in the otherwise concerted healing action of various endogeneous factors recruited for tissue repair. Carcinogenesis is not simply a single-cell problem but a cell-society problem. Therefore, it is not warranted to estimate risk at low doses by linear extrapolation from cancer data at high doses without knowledge of the mechanism of radiation carcinogenesis. (author) 57 refs

  14. Statistical hypothesis tests of some micrometeorological observations

    International Nuclear Information System (INIS)

    SethuRaman, S.; Tichler, J.

    1977-01-01

    Chi-square goodness-of-fit is used to test the hypothesis that the medium scale of turbulence in the atmospheric surface layer is normally distributed. Coefficients of skewness and excess are computed from the data. If the data are not normal, these coefficients are used in Edgeworth's asymptotic expansion of Gram-Charlier series to determine an altrnate probability density function. The observed data are then compared with the modified probability densities and the new chi-square values computed.Seventy percent of the data analyzed was either normal or approximatley normal. The coefficient of skewness g 1 has a good correlation with the chi-square values. Events with vertical-barg 1 vertical-bar 1 vertical-bar<0.43 were approximately normal. Intermittency associated with the formation and breaking of internal gravity waves in surface-based inversions over water is thought to be the reason for the non-normality

  15. The hexagon hypothesis: Six disruptive scenarios.

    Science.gov (United States)

    Burtles, Jim

    2015-01-01

    This paper aims to bring a simple but effective and comprehensive approach to the development, delivery and monitoring of business continuity solutions. To ensure that the arguments and principles apply across the board, the paper sticks to basic underlying concepts rather than sophisticated interpretations. First, the paper explores what exactly people are defending themselves against. Secondly, the paper looks at how defences should be set up. Disruptive events tend to unfold in phases, each of which invites a particular style of protection, ranging from risk management through to business continuity to insurance cover. Their impact upon any business operation will fall into one of six basic scenarios. The hexagon hypothesis suggests that everyone should be prepared to deal with each of these six disruptive scenarios and it provides them with a useful benchmark for business continuity.

  16. Novae, supernovae, and the island universe hypothesis

    International Nuclear Information System (INIS)

    Van Den Bergh, S.

    1988-01-01

    Arguments in Curtis's (1917) paper related to the island universe hypothesis and the existence of novae in spiral nebulae are considered. It is noted that the maximum magnitude versus rate-of-decline relation for novae may be the best tool presently available for the calibration of the extragalactic distance scale. Light curve observations of six novae are used to determine a distance of 18.6 + or - 3.5 MPc to the Virgo cluster. Results suggest that Type Ia supernovae cannot easily be used as standard candles, and that Type II supernovae are unsuitable as distance indicators. Factors other than precursor mass are probably responsible for determining the ultimate fate of evolving stars. 83 references

  17. Extra dimensions hypothesis in high energy physics

    Directory of Open Access Journals (Sweden)

    Volobuev Igor

    2017-01-01

    Full Text Available We discuss the history of the extra dimensions hypothesis and the physics and phenomenology of models with large extra dimensions with an emphasis on the Randall- Sundrum (RS model with two branes. We argue that the Standard Model extension based on the RS model with two branes is phenomenologically acceptable only if the inter-brane distance is stabilized. Within such an extension of the Standard Model, we study the influence of the infinite Kaluza-Klein (KK towers of the bulk fields on collider processes. In particular, we discuss the modification of the scalar sector of the theory, the Higgs-radion mixing due to the coupling of the Higgs boson to the radion and its KK tower, and the experimental restrictions on the mass of the radion-dominated states.

  18. Multiple model cardinalized probability hypothesis density filter

    Science.gov (United States)

    Georgescu, Ramona; Willett, Peter

    2011-09-01

    The Probability Hypothesis Density (PHD) filter propagates the first-moment approximation to the multi-target Bayesian posterior distribution while the Cardinalized PHD (CPHD) filter propagates both the posterior likelihood of (an unlabeled) target state and the posterior probability mass function of the number of targets. Extensions of the PHD filter to the multiple model (MM) framework have been published and were implemented either with a Sequential Monte Carlo or a Gaussian Mixture approach. In this work, we introduce the multiple model version of the more elaborate CPHD filter. We present the derivation of the prediction and update steps of the MMCPHD particularized for the case of two target motion models and proceed to show that in the case of a single model, the new MMCPHD equations reduce to the original CPHD equations.

  19. On the immunostimulatory hypothesis of cancer

    Directory of Open Access Journals (Sweden)

    Juan Bruzzo

    2011-12-01

    Full Text Available There is a rather generalized belief that the worst possible outcome for the application of immunological therapies against cancer is a null effect on tumor growth. However, a significant body of evidence summarized in the immunostimulatory hypothesis of cancer suggests that, upon certain circumstances, the growth of incipient and established tumors can be accelerated rather than inhibited by the immune response supposedly mounted to limit tumor growth. In order to provide more compelling evidence of this proposition, we have explored the growth behavior characteristics of twelve murine tumors -most of them of spontaneous origin- arisen in the colony of our laboratory, in putatively immunized and control mice. Using classical immunization procedures, 8 out of 12 tumors were actually stimulated in "immunized" mice while the remaining 4 were neither inhibited nor stimulated. Further, even these apparently non-antigenic tumors could reveal some antigenicity if more stringent than classical immunization procedures were used. This possibility was suggested by the results obtained with one of these four apparently non-antigenic tumors: the LB lymphoma. In effect, upon these stringent immunization pretreatments, LB was slightly inhibited or stimulated, depending on the titer of the immune reaction mounted against the tumor, with higher titers rendering inhibition and lower titers rendering tumor stimulation. All the above results are consistent with the immunostimulatory hypothesis that entails the important therapeutic implications -contrary to the orthodoxy- that, anti-tumor vaccines may run a real risk of doing harm if the vaccine-induced immunity is too weak to move the reaction into the inhibitory part of the immune response curve and that, a slight and prolonged immunodepression -rather than an immunostimulation- might interfere with the progression of some tumors and thus be an aid to cytotoxic therapies.

  20. The Stress Acceleration Hypothesis of Nightmares

    Directory of Open Access Journals (Sweden)

    Tore Nielsen

    2017-06-01

    Full Text Available Adverse childhood experiences can deleteriously affect future physical and mental health, increasing risk for many illnesses, including psychiatric problems, sleep disorders, and, according to the present hypothesis, idiopathic nightmares. Much like post-traumatic nightmares, which are triggered by trauma and lead to recurrent emotional dreaming about the trauma, idiopathic nightmares are hypothesized to originate in early adverse experiences that lead in later life to the expression of early memories and emotions in dream content. Accordingly, the objectives of this paper are to (1 review existing literature on sleep, dreaming and nightmares in relation to early adverse experiences, drawing upon both empirical studies of dreaming and nightmares and books and chapters by recognized nightmare experts and (2 propose a new approach to explaining nightmares that is based upon the Stress Acceleration Hypothesis of mental illness. The latter stipulates that susceptibility to mental illness is increased by adversity occurring during a developmentally sensitive window for emotional maturation—the infantile amnesia period—that ends around age 3½. Early adversity accelerates the neural and behavioral maturation of emotional systems governing the expression, learning, and extinction of fear memories and may afford short-term adaptive value. But it also engenders long-term dysfunctional consequences including an increased risk for nightmares. Two mechanisms are proposed: (1 disruption of infantile amnesia allows normally forgotten early childhood memories to influence later emotions, cognitions and behavior, including the common expression of threats in nightmares; (2 alterations of normal emotion regulation processes of both waking and sleep lead to increased fear sensitivity and less effective fear extinction. These changes influence an affect network previously hypothesized to regulate fear extinction during REM sleep, disruption of which leads to

  1. O clube de leitura: vigilâncias da escola nova em Santa Catarina (1944–1946

    Directory of Open Access Journals (Sweden)

    José Augusto da Silva Neto

    2017-05-01

    Full Text Available O objeto deste estudo são as associações auxiliares da escola, com o foco nos Clubes de Leitura e Bibliotecas nos Grupos Escolares em Santa Catarina a partir de 1944, pautados Decreto Lei nº2.991. Analisa-se os mecanismos de vigilância presentes na cultura escolar no período da Escola Nova. A investigação tem aporte na História Cultural tendo Roger Chartier como um dos interlocutores. Já a questão da hierarquização das diretrizes escolares têm como aporte teórico os escritos de Michael Foucault. Os resultados apontam para o caráter nacionalista, hierárquico e vigilante das diretrizes analisadas com o objetivo de expandir através de decretos oficiais a pedagogia da Escola Nova.

  2. Extraocular light via the ear canal does not acutely affect human circadian physiology, alertness and psychomotor vigilance performance.

    Science.gov (United States)

    Bromundt, Vivien; Frey, Sylvia; Odermatt, Jonas; Cajochen, Christian

    2014-04-01

    We aimed at testing potential effects of extraocular bright light via the ear canals on human evening melatonin levels, sleepiness and psychomotor vigilance performance. Twenty healthy young men and women (10/10) kept a regular sleep-wake cycle during the 2-week study. The volunteers reported to the laboratory on three evenings, 2 h 15 min before usual bedtime, on average at 21:45 h. They were exposed to three different light conditions, each lasting for 12 min: extraocular bright light via the ear canal, ocular bright light as an active control condition and a control condition (extraocular light therapy device with completely blacked out LEDs). The timing of exposure was on average from 22:48 to 23:00 h. During the 2-h protocol, saliva samples were collected in 15-min intervals for melatonin assays along with subjective sleepiness ratings, and the volunteers performed a 10-min visual psychomotor vigilance task (PVT) prior to and after each light condition. The evening melatonin rise was significantly attenuated after the 12-min ocular bright light exposure while no significant changes were observed after the extraocular bright light and sham light condition. Subjective sleepiness decreased immediately over a short period only after ocular light exposure. No significant differences were observed for mean reaction times and the number of lapses for the PVT between the three light conditions. We conclude that extraocular transcranial light exposure in the late evening does not suppress melatonin, reduce subjective sleepiness or improve performance, and therefore, does not acutely influence the human circadian timing system.

  3. Compassion and vigilance: investigators' strategies to manage ethical concerns in palliative and end-of-life research.

    Science.gov (United States)

    Hickman, Susan E; Cartwright, Juliana C; Nelson, Christine A; Knafl, Kathleen

    2012-08-01

    Ethical concerns were identified as a potential barrier to advancing palliative and end-of-life science at the 2004 National Institutes of Health State of the Science Meeting. However, data are lacking about the nature of ethical concerns and strategies for balancing the need to advance science with human subjects protections. A qualitative case-study design was used to follow 43 end-of-life studies from proposal development through the review process and implementation. Investigators participated in semi-structured telephone interviews and provided document data regarding their experiences with grant and IRB reviews. Using constant comparative analysis within and across cases, the investigators identified commonly encountered and unique concerns and strategies for managing these concerns. Investigator strategies fell into two broad categories: 1) Recruitment and consent strategies related to subject identification and enrollment; and 2) Protocol-related strategies related to the process of data collection. These strategies shared the overarching meta-themes of compassion, as evidenced by a heightened sensitivity to the needs of the population, coupled with vigilance, as evidenced by close attention to the possible effects of study participation on the participants' well-being, clinical care, and the needs of research staff. Ethical concerns have led to the development of compassionate and vigilant strategies designed to balance the potential for risk of harm with the need to advance the science of palliative and end-of-life care. These strategies can be used by investigators to address ethical concerns and minimize barriers to the development of palliative and end-of-life care science.

  4. The Matter-Gravity Entanglement Hypothesis

    Science.gov (United States)

    Kay, Bernard S.

    2018-03-01

    I outline some of my work and results (some dating back to 1998, some more recent) on my matter-gravity entanglement hypothesis, according to which the entropy of a closed quantum gravitational system is equal to the system's matter-gravity entanglement entropy. The main arguments presented are: (1) that this hypothesis is capable of resolving what I call the second-law puzzle, i.e. the puzzle as to how the entropy increase of a closed system can be reconciled with the asssumption of unitary time-evolution; (2) that the black hole information loss puzzle may be regarded as a special case of this second law puzzle and that therefore the same resolution applies to it; (3) that the black hole thermal atmosphere puzzle (which I recall) can be resolved by adopting a radically different-from-usual description of quantum black hole equilibrium states, according to which they are total pure states, entangled between matter and gravity in such a way that the partial states of matter and gravity are each approximately thermal equilibrium states (at the Hawking temperature); (4) that the Susskind-Horowitz-Polchinski string-theoretic understanding of black hole entropy as the logarithm of the degeneracy of a long string (which is the weak string coupling limit of a black hole) cannot be quite correct but should be replaced by a modified understanding according to which it is the entanglement entropy between a long string and its stringy atmosphere, when in a total pure equilibrium state in a suitable box, which (in line with (3)) goes over, at strong-coupling, to a black hole in equilibrium with its thermal atmosphere. The modified understanding in (4) is based on a general result, which I also describe, which concerns the likely state of a quantum system when it is weakly coupled to an energy-bath and the total state is a random pure state with a given energy. This result generalizes Goldstein et al.'s `canonical typicality' result to systems which are not necessarily small.

  5. The Matter-Gravity Entanglement Hypothesis

    Science.gov (United States)

    Kay, Bernard S.

    2018-05-01

    I outline some of my work and results (some dating back to 1998, some more recent) on my matter-gravity entanglement hypothesis, according to which the entropy of a closed quantum gravitational system is equal to the system's matter-gravity entanglement entropy. The main arguments presented are: (1) that this hypothesis is capable of resolving what I call the second-law puzzle, i.e. the puzzle as to how the entropy increase of a closed system can be reconciled with the asssumption of unitary time-evolution; (2) that the black hole information loss puzzle may be regarded as a special case of this second law puzzle and that therefore the same resolution applies to it; (3) that the black hole thermal atmosphere puzzle (which I recall) can be resolved by adopting a radically different-from-usual description of quantum black hole equilibrium states, according to which they are total pure states, entangled between matter and gravity in such a way that the partial states of matter and gravity are each approximately thermal equilibrium states (at the Hawking temperature); (4) that the Susskind-Horowitz-Polchinski string-theoretic understanding of black hole entropy as the logarithm of the degeneracy of a long string (which is the weak string coupling limit of a black hole) cannot be quite correct but should be replaced by a modified understanding according to which it is the entanglement entropy between a long string and its stringy atmosphere, when in a total pure equilibrium state in a suitable box, which (in line with (3)) goes over, at strong-coupling, to a black hole in equilibrium with its thermal atmosphere. The modified understanding in (4) is based on a general result, which I also describe, which concerns the likely state of a quantum system when it is weakly coupled to an energy-bath and the total state is a random pure state with a given energy. This result generalizes Goldstein et al.'s `canonical typicality' result to systems which are not necessarily small.

  6. Reduction of nocturnal slow-wave activity affects daytime vigilance lapses and memory encoding but not reaction time or implicit learning

    NARCIS (Netherlands)

    van der Werf, Y.D.; Altena, E.; Vis, J.C.; Koene, T.; van Someren, E.J.W.

    2011-01-01

    Total sleep deprivation in healthy subjects has a profound effect on the performance on tasks measuring sustained attention or vigilance. We here report how a selective disruption of deep sleep only, that is, selective slow-wave activity (SWA) reduction, affects the performance of healthy

  7. Psychometric Properties of the German Version of the Pain Vigilance and Awareness Questionnaire (PVAQ) in Pain-Free Samples and Samples with Acute and Chronic Pain

    NARCIS (Netherlands)

    Kunz, M.; Capito, E. S.; Horn-Hofmann, C.; Baum, C.; Scheel, J.; Karmann, A. J.; Priebe, J. A.; Lautenbacher, S.

    The way individuals attend to pain is known to have a considerable impact on the experience and chronification of pain. One method to assess the habitual "attention to pain" is the Pain Vigilance and Awareness Questionnaire (PVAQ). With the present study, we aimed to test the psychometric properties

  8. Marginal contrasts and the Contrastivist Hypothesis

    Directory of Open Access Journals (Sweden)

    Daniel Currie Hall

    2016-12-01

    Full Text Available The Contrastivist Hypothesis (CH; Hall 2007; Dresher 2009 holds that the only features that can be phonologically active in any language are those that serve to distinguish phonemes, which presupposes that phonemic status is categorical. Many researchers, however, demonstrate the existence of gradient relations. For instance, Hall (2009 quantifies these using the information-theoretic measure of entropy (unpredictability of distribution and shows that a pair of sounds may have an entropy between 0 (totally predictable and 1 (totally unpredictable. We argue that the existence of such intermediate degrees of contrastiveness does not make the CH untenable, but rather offers insight into contrastive hierarchies. The existence of a continuum does not preclude categorical distinctions: a categorical line can be drawn between zero entropy (entirely predictable, and thus by the CH phonologically inactive and non-zero entropy (at least partially contrastive, and thus potentially phonologically active. But this does not mean that intermediate degrees of surface contrastiveness are entirely irrelevant to the CH; rather, we argue, they can shed light on how deeply ingrained a phonemic distinction is in the phonological system. As an example, we provide a case study from Pulaar [ATR] harmony, which has previously been claimed to be problematic for the CH.

  9. The Stem Cell Hypothesis of Aging

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2010-04-01

    Full Text Available BACKGROUND: There is probably no single way to age. Indeed, so far there is no single accepted explanation or mechanisms of aging (although more than 300 theories have been proposed. There is an overall decline in tissue regenerative potential with age, and the question arises as to whether this is due to the intrinsic aging of stem cells or rather to the impairment of stem cell function in the aged tissue environment. CONTENT: Recent data suggest that we age, in part, because our self-renewing stem cells grow old as a result of heritable intrinsic events, such as DNA damage, as well as extrinsic forces, such as changes in their supporting niches. Mechanisms that suppress the development of cancer, such as senescence and apoptosis, which rely on telomere shortening and the activities of p53 and p16INK4a may also induce an unwanted consequence: a decline in the replicative function of certain stem cells types with advancing age. This decrease regenerative capacity appears to pointing to the stem cell hypothesis of aging. SUMMARY: Recent evidence suggested that we grow old partly because of our stem cells grow old as a result of mechanisms that suppress the development of cancer over a lifetime. We believe that a further, more precise mechanistic understanding of this process will be required before this knowledge can be translated into human anti-aging therapies. KEYWORDS: stem cells, senescence, telomere, DNA damage, epigenetic, aging.

  10. Confabulation: Developing the 'emotion dysregulation' hypothesis.

    Science.gov (United States)

    Turnbull, Oliver H; Salas, Christian E

    2017-02-01

    Confabulations offer unique opportunities for establishing the neurobiological basis of delusional thinking. As regards causal factors, a review of the confabulation literature suggests that neither amnesia nor executive impairment can be the sole (or perhaps even the primary) cause of all delusional beliefs - though they may act in concert with other factors. A key perspective in the modern literature is that many delusions have an emotionally positive or 'wishful' element, that may serve to modulate or manage emotional experience. Some authors have referred to this perspective as the 'emotion dysregulation' hypothesis. In this article we review the theoretical underpinnings of this approach, and develop the idea by suggesting that the positive aspects of confabulatory states may have a role in perpetuating the imbalance between cognitive control and emotion. We draw on existing evidence from fields outside neuropsychology, to argue for three main causal factors: that positive emotions are related to more global or schematic forms of cognitive processing; that positive emotions influence the accuracy of memory recollection; and that positive emotions make people more susceptible to false memories. These findings suggest that the emotions that we want to feel (or do not want to feel) can influence the way we reconstruct past experiences and generate a sense of self - a proposition that bears on a unified theory of delusional belief states. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  11. Evolutionary hypothesis for Chiari type I malformation.

    Science.gov (United States)

    Fernandes, Yvens Barbosa; Ramina, Ricardo; Campos-Herrera, Cynthia Resende; Borges, Guilherme

    2013-10-01

    Chiari I malformation (CM-I) is classically defined as a cerebellar tonsillar herniation (≥5 mm) through the foramen magnum. A decreased posterior fossa volume, mainly due to basioccipital hypoplasia and sometimes platybasia, leads to posterior fossa overcrowding and consequently cerebellar herniation. Regardless of radiological findings, embryological genetic hypothesis or any other postulations, the real cause behind this malformation is yet not well-elucidated and remains largely unknown. The aim of this paper is to approach CM-I under a broader and new perspective, conjoining anthropology, genetics and neurosurgery, with special focus on the substantial changes that have occurred in the posterior cranial base through human evolution. Important evolutionary allometric changes occurred during brain expansion and genetics studies of human evolution demonstrated an unexpected high rate of gene flow interchange and possibly interbreeding during this process. Based upon this review we hypothesize that CM-I may be the result of an evolutionary anthropological imprint, caused by evolving species populations that eventually met each other and mingled in the last 1.7 million years. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Environmental Kuznets Curve Hypothesis. A Survey

    International Nuclear Information System (INIS)

    Dinda, Soumyananda

    2004-01-01

    The Environmental Kuznets Curve (EKC) hypothesis postulates an inverted-U-shaped relationship between different pollutants and per capita income, i.e., environmental pressure increases up to a certain level as income goes up; after that, it decreases. An EKC actually reveals how a technically specified measurement of environmental quality changes as the fortunes of a country change. A sizeable literature on EKC has grown in recent period. The common point of all the studies is the assertion that the environmental quality deteriorates at the early stages of economic development/growth and subsequently improves at the later stages. In other words, environmental pressure increases faster than income at early stages of development and slows down relative to GDP growth at higher income levels. This paper reviews some theoretical developments and empirical studies dealing with EKC phenomenon. Possible explanations for this EKC are seen in (1) the progress of economic development, from clean agrarian economy to polluting industrial economy to clean service economy; (2) tendency of people with higher income having higher preference for environmental quality, etc. Evidence of the existence of the EKC has been questioned from several corners. Only some air quality indicators, especially local pollutants, show the evidence of an EKC. However, an EKC is empirically observed, till there is no agreement in the literature on the income level at which environmental degradation starts declining. This paper provides an overview of the EKC literature, background history, conceptual insights, policy and the conceptual and methodological critique

  13. DAMPs, ageing, and cancer: The 'DAMP Hypothesis'.

    Science.gov (United States)

    Huang, Jin; Xie, Yangchun; Sun, Xiaofang; Zeh, Herbert J; Kang, Rui; Lotze, Michael T; Tang, Daolin

    2015-11-01

    Ageing is a complex and multifactorial process characterized by the accumulation of many forms of damage at the molecular, cellular, and tissue level with advancing age. Ageing increases the risk of the onset of chronic inflammation-associated diseases such as cancer, diabetes, stroke, and neurodegenerative disease. In particular, ageing and cancer share some common origins and hallmarks such as genomic instability, epigenetic alteration, aberrant telomeres, inflammation and immune injury, reprogrammed metabolism, and degradation system impairment (including within the ubiquitin-proteasome system and the autophagic machinery). Recent advances indicate that damage-associated molecular pattern molecules (DAMPs) such as high mobility group box 1, histones, S100, and heat shock proteins play location-dependent roles inside and outside the cell. These provide interaction platforms at molecular levels linked to common hallmarks of ageing and cancer. They can act as inducers, sensors, and mediators of stress through individual plasma membrane receptors, intracellular recognition receptors (e.g., advanced glycosylation end product-specific receptors, AIM2-like receptors, RIG-I-like receptors, and NOD1-like receptors, and toll-like receptors), or following endocytic uptake. Thus, the DAMP Hypothesis is novel and complements other theories that explain the features of ageing. DAMPs represent ideal biomarkers of ageing and provide an attractive target for interventions in ageing and age-associated diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Identity of Particles and Continuum Hypothesis

    Science.gov (United States)

    Berezin, Alexander A.

    2001-04-01

    Why all electrons are the same? Unlike other objects, particles and atoms (same isotopes) are forbidden to have individuality or personal history (or reveal their hidden variables, even if they do have them). Or at least, what we commonly call physics so far was unable to disprove particle's sameness (Berezin and Nakhmanson, Physics Essays, 1990). Consider two opposing hypotheses: (A) particles are indeed absolutely same, or (B) they do have individuality, but it is beyond our capacity to demonstrate. This dilemma sounds akin to undecidability of Continuum Hypothesis of existence (or not) of intermediate cardinalities between integers and reals (P.Cohen). Both yes and no of it are true. Thus, (alleged) sameness of electrons and atoms may be a physical translation (embodiment) of this fundamental Goedelian undecidability. Experiments unlikely to help: even if we find that all electrons are same within 30 decimal digits, could their masses (or charges) still differ in100-th digit? Within (B) personalized informationally rich (infinitely rich?) digital tails (starting at, say, 100-th decimal) may carry individual record of each particle history. Within (A) parameters (m, q) are indeed exactly same in all digits and their sameness is based on some inherent (meta)physical principle akin to Platonism or Eddington-type numerology.

  15. Environmental Kuznets Curve Hypothesis. A Survey

    Energy Technology Data Exchange (ETDEWEB)

    Dinda, Soumyananda [Economic Research Unit, Indian Statistical Institute, 203, B.T. Road, Kolkata-108 (India)

    2004-08-01

    The Environmental Kuznets Curve (EKC) hypothesis postulates an inverted-U-shaped relationship between different pollutants and per capita income, i.e., environmental pressure increases up to a certain level as income goes up; after that, it decreases. An EKC actually reveals how a technically specified measurement of environmental quality changes as the fortunes of a country change. A sizeable literature on EKC has grown in recent period. The common point of all the studies is the assertion that the environmental quality deteriorates at the early stages of economic development/growth and subsequently improves at the later stages. In other words, environmental pressure increases faster than income at early stages of development and slows down relative to GDP growth at higher income levels. This paper reviews some theoretical developments and empirical studies dealing with EKC phenomenon. Possible explanations for this EKC are seen in (1) the progress of economic development, from clean agrarian economy to polluting industrial economy to clean service economy; (2) tendency of people with higher income having higher preference for environmental quality, etc. Evidence of the existence of the EKC has been questioned from several corners. Only some air quality indicators, especially local pollutants, show the evidence of an EKC. However, an EKC is empirically observed, till there is no agreement in the literature on the income level at which environmental degradation starts declining. This paper provides an overview of the EKC literature, background history, conceptual insights, policy and the conceptual and methodological critique.

  16. A NONPARAMETRIC HYPOTHESIS TEST VIA THE BOOTSTRAP RESAMPLING

    OpenAIRE

    Temel, Tugrul T.

    2001-01-01

    This paper adapts an already existing nonparametric hypothesis test to the bootstrap framework. The test utilizes the nonparametric kernel regression method to estimate a measure of distance between the models stated under the null hypothesis. The bootstraped version of the test allows to approximate errors involved in the asymptotic hypothesis test. The paper also develops a Mathematica Code for the test algorithm.

  17. Vigilância ambiental em saúde e sua implantação no Sistema Único de Saúde

    Directory of Open Access Journals (Sweden)

    Barcellos Christovam

    2006-01-01

    Full Text Available A incorporação da vigilância ambiental no campo das políticas públicas de saúde é uma demanda relativamente recente no Brasil. Um dos principais desafios da vigilância ambiental em saúde é a definição do seu objeto e a especificidade de suas ações. O conceito ampliado de exposição, tratado não como um atributo da pessoa, mas do conjunto de relações complexas entre a sociedade e o ambiente, é central para a definição de indicadores e para a orientação da prática de vigilância ambiental. Entre as dificuldades encontradas para sua efetivação no Sistema Único de Saúde estão a necessidade de reestruturação das ações de vigilância em saúde e a formação de equipes multidisciplinares, com capacidade de diálogo com outros setores, além da construção de sistemas de informação capazes de auxiliar a análise de situações de saúde e a tomada de decisões. Nesse sentido, foi realizada uma revisão do objeto e conceitos da vigilância ambiental em saúde, bem como identificados os desafios para a sua implantação no Sistema Único de Saúde.

  18. Caminhos possíveis para a avaliação das práticas da Vigilância em Saúde

    Directory of Open Access Journals (Sweden)

    Maria Filomena de Gouveia Vilela

    Full Text Available Resumo Trata-se de pesquisa avaliativa, qualitativa que se propôs investigar a autoavaliação como dispositivo de análise das práticas da Vigilância em Saúde, valendo-se de questionário construído pelos pesquisadores, adaptado da Autovaliação da Melhoria do Acesso e da Qualidade da Atenção Básica (AMAQ e disponibilizado na plataforma FORMSUS. Quarenta e um trabalhadores e gestores da Vigilância em Saúde de um município de grande porte do estado de São Paulo avaliaram as dimensões da “gestão” e “trabalho da equipe” e suas respectivas subdimensões. Criaram-se duas categorias de análise dos resultados: “Gestão” e “Equipe”, em diálogo com referenciais da Gestão, Avaliação e Vigilância em Saúde. A maior parte das subdimensões da “gestão” e “trabalho da equipe” foram avaliadas como satisfatórias. A autoavaliação, mediante o instrumento aplicado, mostrou-se potente para a análise das práticas da Vigilância em Saúde, em conjunto com outros dispositivos adotados no SUS. Diferentemente dos processos habituais de avaliação, pautados em indicadores quantitativos, este processo autoavaliativo incluiu os sujeitos e trouxe a possibilidade de incorporar aos modos de fazer da Vigilância em Saúde o olhar para si e sustentar futuros contratos de gestão entre trabalhadores e gestores.

  19. Reduction of nocturnal slow-wave activity affects daytime vigilance lapses and memory encoding but not reaction time or implicit learning.

    Science.gov (United States)

    Van Der Werf, Ysbrand D; Altena, Ellemarije; Vis, José C; Koene, Teddy; Van Someren, Eus J W

    2011-01-01

    Total sleep deprivation in healthy subjects has a profound effect on the performance on tasks measuring sustained attention or vigilance. We here report how a selective disruption of deep sleep only, that is, selective slow-wave activity (SWA) reduction, affects the performance of healthy well-sleeping subjects on several tasks: a "simple" and a "complex" vigilance task, a declarative learning task, and an implicit learning task despite unchanged duration of sleep. We used automated electroencephalogram (EEG) dependent acoustic feedback aimed at selective interference with-and reduction of-SWA. In a within-subject repeated measures crossover design, performance on the tasks was assessed in 13 elderly adults without sleep complaints after either SWA-reduction or after normal sleep. The number of vigilance lapses increased as a result of SWA reduction, irrespective of the type of vigilance task. Recognition on the declarative memory task was also affected by SWA reduction, associated with a decreased activation of the right hippocampus on encoding (measured with fMRI) suggesting a weaker memory trace. SWA reduction, however, did not affect reaction time on either of the vigilance tasks or implicit memory task performance. These findings suggest a specific role of slow oscillations in the subsequent daytime ability to maintain sustained attention and to encode novel declarative information but not to maintain response speed or to build implicit memories. Of particular interest is that selective SWA reduction can mimic some of the effects of total sleep deprivation, while not affecting sleep duration. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. TNFα G308A polymorphism is associated with resilience to sleep deprivation-induced psychomotor vigilance performance impairment in healthy young adults.

    Science.gov (United States)

    Satterfield, Brieann C; Wisor, Jonathan P; Field, Stephanie A; Schmidt, Michelle A; Van Dongen, Hans P A

    2015-07-01

    Cytokines such as TNFα play an integral role in sleep/wake regulation and have recently been hypothesized to be involved in cognitive impairment due to sleep deprivation. We examined the effect of a guanine to adenine substitution at position 308 in the TNFα gene (TNFα G308A) on psychomotor vigilance performance impairment during total sleep deprivation. A total of 88 healthy women and men (ages 22-40) participated in one of five laboratory total sleep deprivation experiments. Performance on a psychomotor vigilance test (PVT) was measured every 2-3h. The TNFα 308A allele, which is less common than the 308G allele, was associated with greater resilience to psychomotor vigilance performance impairment during total sleep deprivation (regardless of time of day), and also provided a small performance benefit at baseline. The effect of genotype on resilience persisted when controlling for between-subjects differences in age, gender, race/ethnicity, and baseline sleep duration. The TNFα G308A polymorphism predicted less than 10% of the overall between-subjects variance in performance impairment during sleep deprivation. Nonetheless, the differential effect of the polymorphism at the peak of performance impairment was more than 50% of median performance impairment at that time, which is sizeable compared to the effects of other genotypes reported in the literature. Our findings provided evidence for a role of TNFα in the effects of sleep deprivation on psychomotor vigilance performance. Furthermore, the TNFα G308A polymorphism may have predictive potential in a biomarker panel for the assessment of resilience to psychomotor vigilance performance impairment due to sleep deprivation. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Vigilância ambiental em saúde e sua implantação no Sistema Único de Saúde

    Directory of Open Access Journals (Sweden)

    Christovam Barcellos

    2006-02-01

    Full Text Available A incorporação da vigilância ambiental no campo das políticas públicas de saúde é uma demanda relativamente recente no Brasil. Um dos principais desafios da vigilância ambiental em saúde é a definição do seu objeto e a especificidade de suas ações. O conceito ampliado de exposição, tratado não como um atributo da pessoa, mas do conjunto de relações complexas entre a sociedade e o ambiente, é central para a definição de indicadores e para a orientação da prática de vigilância ambiental. Entre as dificuldades encontradas para sua efetivação no Sistema Único de Saúde estão a necessidade de reestruturação das ações de vigilância em saúde e a formação de equipes multidisciplinares, com capacidade de diálogo com outros setores, além da construção de sistemas de informação capazes de auxiliar a análise de situações de saúde e a tomada de decisões. Nesse sentido, foi realizada uma revisão do objeto e conceitos da vigilância ambiental em saúde, bem como identificados os desafios para a sua implantação no Sistema Único de Saúde.

  2. Updating the mild encephalitis hypothesis of schizophrenia.

    Science.gov (United States)

    Bechter, K

    2013-04-05

    Schizophrenia seems to be a heterogeneous disorder. Emerging evidence indicates that low level neuroinflammation (LLNI) may not occur infrequently. Many infectious agents with low overall pathogenicity are risk factors for psychoses including schizophrenia and for autoimmune disorders. According to the mild encephalitis (ME) hypothesis, LLNI represents the core pathogenetic mechanism in a schizophrenia subgroup that has syndromal overlap with other psychiatric disorders. ME may be triggered by infections, autoimmunity, toxicity, or trauma. A 'late hit' and gene-environment interaction are required to explain major findings about schizophrenia, and both aspects would be consistent with the ME hypothesis. Schizophrenia risk genes stay rather constant within populations despite a resulting low number of progeny; this may result from advantages associated with risk genes, e.g., an improved immune response, which may act protectively within changing environments, although they are associated with the disadvantage of increased susceptibility to psychotic disorders. Specific schizophrenic symptoms may arise with instances of LLNI when certain brain functional systems are involved, in addition to being shaped by pre-existing liability factors. Prodrome phase and the transition to a diseased status may be related to LLNI processes emerging and varying over time. The variability in the course of schizophrenia resembles the varying courses of autoimmune disorders, which result from three required factors: genes, the environment, and the immune system. Preliminary criteria for subgrouping neurodevelopmental, genetic, ME, and other types of schizophrenias are provided. A rare example of ME schizophrenia may be observed in Borna disease virus infection. Neurodevelopmental schizophrenia due to early infections has been estimated by others to explain approximately 30% of cases, but the underlying pathomechanisms of transition to disease remain in question. LLNI (e.g. from

  3. [Psychodynamic hypothesis about suicidality in elderly men].

    Science.gov (United States)

    Lindner, Reinhard

    2010-08-01

    Old men are overrepresented in the whole of all suicides. In contrast, only very few elderly men find their way to specialised treatment facilities. Elderly accept psychotherapy more rarely than younger persons. Therefore presentations on the psychodynamics of suicidality in old men are rare and mostly casuistical. By means of a stepwise reconstructable qualitative case comparison of five randomly chosen elderly suicidal men with ideal types of suicidal (younger) men concerning biography, suicidal symptoms and transference, psychodynamic hypothesis of suicidality in elderly men are developed. All patients came into psychotherapy in a specialised academic out-patient clinic for psychodynamic treatment of acute and chronic suicidality. The five elderly suicidal men predominantly were living in long-term, conflictuous sexual relationships and also had ambivalent relationships to their children. Suicidality in old age refers to lifelong existing intrapsychic conflicts, concerning (male) identity, self-esteem and a core conflict between fusion and separation wishes. The body gets a central role in suicidal experiences, being a defensive instance modified by age and/or physical illness, which brings up to consciousness aggressive and envious impulses, but also feelings of emptiness and insecurity, which have to be warded off again by projection into the body. In transference relationships there are on the one hand the regular transference, on the other hand an age specific turned around transference, with their counter transference reactions. The chosen methodological approach serves the systematic finding of hypotheses with a higher degree in evidence than hypotheses generated from single case studies. Georg Thieme Verlag KG Stuttgart - New York.

  4. Atopic dermatitis and the hygiene hypothesis revisited.

    Science.gov (United States)

    Flohr, Carsten; Yeo, Lindsey

    2011-01-01

    We published a systematic review on atopic dermatitis (AD) and the hygiene hypothesis in 2005. Since then, the body of literature has grown significantly. We therefore repeated our systematic review to examine the evidence from population-based studies for an association between AD risk and specific infections, childhood immunizations, the use of antibiotics and environmental exposures that lead to a change in microbial burden. Medline was searched from 1966 until June 2010 to identify relevant studies. We found an additional 49 papers suitable for inclusion. There is evidence to support an inverse relationship between AD and endotoxin, early day care, farm animal and dog exposure in early life. Cat exposure in the presence of skin barrier impairment is positively associated with AD. Helminth infection at least partially protects against AD. This is not the case for viral and bacterial infections, but consumption of unpasteurized farm milk seems protective. Routine childhood vaccinations have no effect on AD risk. The positive association between viral infections and AD found in some studies appears confounded by antibiotic prescription, which has been consistently associated with an increase in AD risk. There is convincing evidence for an inverse relationship between helminth infections and AD but no other pathogens. The protective effect seen with early day care, endotoxin, unpasteurized farm milk and animal exposure is likely to be due to a general increase in exposure to non-pathogenic microbes. This would also explain the risk increase associated with the use of broad-spectrum antibiotics. Future studies should assess skin barrier gene mutation carriage and phenotypic skin barrier impairment, as gene-environment interactions are likely to impact on AD risk. Copyright © 041_ S. Karger AG, Basel.

  5. Habitat fragmentation, vole population fluctuations, and the ROMPA hypothesis: An experimental test using model landscapes.

    Science.gov (United States)

    Batzli, George O

    2016-11-01

    Increased habitat fragmentation leads to smaller size of habitat patches and to greater distance between patches. The ROMPA hypothesis (ratio of optimal to marginal patch area) uniquely links vole population fluctuations to the composition of the landscape. It states that as ROMPA decreases (fragmentation increases), vole population fluctuations will increase (including the tendency to display multi-annual cycles in abundance) because decreased proportions of optimal habitat result in greater population declines and longer recovery time after a harsh season. To date, only comparative observations in the field have supported the hypothesis. This paper reports the results of the first experimental test. I used prairie voles, Microtus ochrogaster, and mowed grassland to create model landscapes with 3 levels of ROMPA (high with 25% mowed, medium with 50% mowed and low with 75% mowed). As ROMPA decreased, distances between patches of favorable habitat (high cover) increased owing to a greater proportion of unfavorable (mowed) habitat. Results from the first year with intensive live trapping indicated that the preconditions for operation of the hypothesis existed (inversely density dependent emigration and, as ROMPA decreased, increased per capita mortality and decreased per capita movement between optimal patches). Nevertheless, contrary to the prediction of the hypothesis that populations in landscapes with high ROMPA should have the lowest variability, 5 years of trapping indicated that variability was lowest with medium ROMPA. The design of field experiments may never be perfect, but these results indicate that the ROMPA hypothesis needs further rigorous testing. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  6. Risk-Based, Hypothesis-Driven Framework for Hydrological Field Campaigns with Case Studies

    Science.gov (United States)

    Harken, B.; Rubin, Y.

    2014-12-01

    There are several stages in any hydrological modeling campaign, including: formulation and analysis of a priori information, data acquisition through field campaigns, inverse modeling, and prediction of some environmental performance metric (EPM). The EPM being predicted could be, for example, contaminant concentration or plume travel time. These predictions often have significant bearing on a decision that must be made. Examples include: how to allocate limited remediation resources between contaminated groundwater sites or where to place a waste repository site. Answering such questions depends on predictions of EPMs using forward models as well as levels of uncertainty related to these predictions. Uncertainty in EPM predictions stems from uncertainty in model parameters, which can be reduced by measurements taken in field campaigns. The costly nature of field measurements motivates a rational basis for determining a measurement strategy that is optimal with respect to the uncertainty in the EPM prediction. The tool of hypothesis testing allows this uncertainty to be quantified by computing the significance of the test resulting from a proposed field campaign. The significance of the test gives a rational basis for determining the optimality of a proposed field campaign. This hypothesis testing framework is demonstrated and discussed using various synthetic case studies. This study involves contaminated aquifers where a decision must be made based on prediction of when a contaminant will arrive at a specified location. The EPM, in this case contaminant travel time, is cast into the hypothesis testing framework. The null hypothesis states that the contaminant plume will arrive at the specified location before a critical amount of time passes, and the alternative hypothesis states that the plume will arrive after the critical time passes. The optimality of different field campaigns is assessed by computing the significance of the test resulting from each one

  7. Phi index: a new metric to test the flush early and avoid the rush hypothesis.

    Science.gov (United States)

    Samia, Diogo S M; Blumstein, Daniel T

    2014-01-01

    Optimal escape theory states that animals should counterbalance the costs and benefits of flight when escaping from a potential predator. However, in apparent contradiction with this well-established optimality model, birds and mammals generally initiate escape soon after beginning to monitor an approaching threat, a phenomena codified as the "Flush Early and Avoid the Rush" (FEAR) hypothesis. Typically, the FEAR hypothesis is tested using correlational statistics and is supported when there is a strong relationship between the distance at which an individual first responds behaviorally to an approaching predator (alert distance, AD), and its flight initiation distance (the distance at which it flees the approaching predator, FID). However, such correlational statistics are both inadequate to analyze relationships constrained by an envelope (such as that in the AD-FID relationship) and are sensitive to outliers with high leverage, which can lead one to erroneous conclusions. To overcome these statistical concerns we develop the phi index (Φ), a distribution-free metric to evaluate the goodness of fit of a 1:1 relationship in a constraint envelope (the prediction of the FEAR hypothesis). Using both simulation and empirical data, we conclude that Φ is superior to traditional correlational analyses because it explicitly tests the FEAR prediction, is robust to outliers, and it controls for the disproportionate influence of observations from large predictor values (caused by the constrained envelope in AD-FID relationship). Importantly, by analyzing the empirical data we corroborate the strong effect that alertness has on flight as stated by the FEAR hypothesis.

  8. Factoring handedness data: II. Geschwind's multidimensional hypothesis.

    Science.gov (United States)

    Messinger, H B; Messinger, M I

    1996-06-01

    The challenge in this journal by Peters and Murphy to the validity of two published factor analyses of handedness data because of bimodality was dealt with in Part I by identifying measures to normalize the handedness item distributions. A new survey using Oldfield's questionnaire format had 38 bell-shaped (unimodal) handedness-item distributions and 11 that were only marginally bimodal out of the 55 items used in Geschwind's 1986 study. Yet they were still non-normal and the factor analysis was unsatisfactory; bimodality is not the only problem. By choosing a transformation for each item that was optimal as assessed by D'Agostino's K2 statistic, all but two items could be normalized. Seven factors were derived that showed high congruence between maximum likelihood and principal components extractions before and after varimax rotation. Geschwind's assertion that handedness is not unidimensional is therefore supported.

  9. Multitarget botanical pharmacotherapy in major depression: a toxic brain hypothesis.

    Science.gov (United States)

    Tang, Siu W; Tang, Wayne H; Leonard, Brain E

    2017-11-01

    A significant number of patients with major depression do not respond optimally to current antidepressant drugs. As depression is likely to be a heterogeneous disorder, it is possible that existing neurotransmitter-based antidepressant drugs do not fully address other pathologies that may exist in certain cases. Biological pathologies related to depression that have been proposed and studied extensively include inflammation and immunology, hypercortisolemia, oxidative stress, and impaired angiogenesis. Such pathologies may induce neurodegeneration, which in turn causes cognitive impairment, a symptom increasingly being recognized in depression. A neurotoxic brain hypothesis unifying all these factors may explain the heterogeneity of depression as well as cognitive decline and antidepressant drug resistance in some patients. Compared with neurotransmitter-based antidepressant drugs, many botanical compounds in traditional medicine used for the treatment of depression and its related symptoms have been discovered to be anti-inflammatory, immunoregulatory, anti-infection, antioxidative, and proangiogenic. Some botanical compounds also exert actions on neurotransmission. This multitarget nature of botanical medicine may act through the amelioration of the neurotoxic brain environment in some patients resistant to neurotransmitter-based antidepressant drugs. A multitarget multidimensional approach may be a reasonable solution for patients resistant to neurotransmitter-based antidepressant drugs.

  10. Early hominins in Europe: The Galerian migration hypothesis

    Science.gov (United States)

    Muttoni, Giovanni; Scardia, Giancarlo; Kent, Dennis V.

    2018-01-01

    Our updated review of sites bearing hominin remains and/or tools from Europe, including new findings from the Balkans, still indicates that the only compelling evidence of main hominin presence in these regions was only since ∼0.9 million years ago (Ma), bracketed by the end of the Jaramillo geomagnetic polarity subchron (0.99 Ma) and the Brunhes-Matuyama polarity chron boundary (0.78 Ma). This time window straddled the late Early Pleistocene climate transition (EPT) at the onset of enhanced glacial/interglacial activity that reverberated worldwide. Europe may have become initially populated during the EPT when, possibly for the first time in the Pleistocene, vast and exploitable ecosystems were generated along the eustatically emergent Po-Danube terrestrial conduit. These newly formed settings, characterized by stable terrestrial lowlands with open grasslands and reduced woody cover especially during glacial/interglacial transitions, are regarded as optimal ecosystems for several large Galerian immigrant mammals such as African and Asian megaherbivores, possibly linked with hominins in a common food web, to expand into en route to Europe. The question of when hominins first arrived in Europe thus places the issue in the context of changes in climate, paleogeography and faunal associations as potential environmental drivers and controlling agents in a specific time frame, a key feature of the Galerian migration hypothesis.

  11. The zinc dyshomeostasis hypothesis of Alzheimer's disease.

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    Travis J A Craddock

    Full Text Available Alzheimer's disease (AD is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ, intracellular neurofibrillary tangles (NFTs composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau, and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1 used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2 performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3 used metallomic imaging mass spectrometry (MIMS to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of

  12. The zinc dyshomeostasis hypothesis of Alzheimer's disease.

    Science.gov (United States)

    Craddock, Travis J A; Tuszynski, Jack A; Chopra, Deepak; Casey, Noel; Goldstein, Lee E; Hameroff, Stuart R; Tanzi, Rudolph E

    2012-01-01

    Alzheimer's disease (AD) is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ), intracellular neurofibrillary tangles (NFTs) composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau), and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques) not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1) used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2) performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3) used metallomic imaging mass spectrometry (MIMS) to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of polymerized

  13. Can providing feedback on driving behavior and training on parental vigilant care affect male teen drivers and their parents?

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    Farah, Haneen; Musicant, Oren; Shimshoni, Yaara; Toledo, Tomer; Grimberg, Einat; Omer, Haim; Lotan, Tsippy

    2014-08-01

    This study focuses on investigating the driving behavior of young novice male drivers during the first year of driving (three months of accompanied driving and the following nine months of solo driving). The study's objective is to examine the potential of various feedback forms on driving to affect young drivers' behavior and to mitigate the transition from accompanied to solo driving. The study examines also the utility of providing parents with guidance on how to exercise vigilant care regarding their teens' driving. Driving behavior was evaluated using data collected by In-Vehicle Data Recorders (IVDR), which document events of extreme g-forces measured in the vehicles. IVDR systems were installed in 242 cars of the families of young male drivers, however, only 217 families of young drivers aged 17-22 (M=17.5; SD=0.8) completed the one year period. The families were randomly allocated into 4 groups: (1) Family feedback: In which all the members of the family were exposed to feedback on their own driving and on that of the other family members; (2) Parental training: in which in addition to the family feedback, parents received personal guidance on ways to enhance vigilant care regarding their sons' driving; (3) Individual feedback: In which family members received feedback only on their own driving behavior (and were not exposed to the data on other family members); (4) CONTROL: Group that received no feedback at all. The feedback was provided to the different groups starting from the solo period, thus, the feedback was not provided during the supervised period. The data collected by the IVDRs was first analyzed using analysis of variance in order to compare the groups with respect to their monthly event rates. Events' rates are defined as the number of events in a trip divided by its duration. This was followed by the development and estimation of random effect negative binomial models that explain the monthly event rates of young drivers and their parents

  14. Vigilance task-related change in brain functional connectivity as revealed by wavelet phase coherence analysis of near-infrared spectroscopy signals

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    Wang Wei

    2016-08-01

    Full Text Available This study aims to assess the vigilance task-related change in connectivity in healthy adults using wavelet phase coherence (WPCO analysis of near-infrared spectroscopy signals (NIRS. NIRS is a non-invasive neuroimaging technique for assessing brain activity. Continuous recordings of the NIRS signals were obtained from the prefrontal cortex (PFC and sensorimotor cortical areas of 20 young healthy adults (24.9±3.3 years during a 10-min resting state and a 20-min vigilance task state. The vigilance task was used to simulate driving mental load by judging three random numbers (i.e., whether odd numbers. The task was divided into two sessions: the first 10 minutes (Task t1 and the second 10 minutes (Task t2. The WPCO of six channel pairs were calculated in five frequency intervals: 0.6–2 Hz (I, 0.145–0.6 Hz (II, 0.052–0.145 Hz (III, 0.021–0.052 Hz (IV, and 0.0095–0.021 Hz (V. The significant WPCO formed global connectivity (GC maps in intervals I and II and functional connectivity (FC maps in intervals III to V. Results show that the GC levels in interval I and FC levels in interval III were significantly lower in the Task t2 than in the resting state (p < 0.05, particularly between the left PFC and bilateral sensorimotor regions. Also, the reaction time shows an increase in Task t2 compared with that in Task t1. However, no significant difference in WPCO was found between Task t1 and resting state. The results showed that the change in FC at the range of 0.6-2 Hz was not attributed to the vigilance task pe se, but the interaction effect of vigilance task and time factors. The findings suggest that the decreased attention level might be partly attributed to the reduced GC levels between the left prefrontal region and sensorimotor area. The present results provide a new insight into the vigilance task-related brain activity.

  15. Fatigue and Cognitive Fatigability in Mild Traumatic Brain Injury are Correlated with Altered Neural Activity during Vigilance Test Performance

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    Marika C. Möller

    2017-09-01

    Full Text Available IntroductionFatigue is the most frequently reported persistent symptom following a mild traumatic brain injury (mTBI, but the explanations for the persisting fatigue symptoms in mTBI remain controversial. In this study, we investigated the change of cerebral blood flow during the performance of a psychomotor vigilance task (PVT by using pseudo-continuous arterial spin labeling (PCASL MRI technique to better understand the relationship between fatigability and brain activity in mTBI.Material and methodsTen patients (mean age: 37.5 ± 11.2 years with persistent complaints of fatigue after mTBI and 10 healthy controls (mean age 36.9 ± 11.0 years were studied. Both groups completed a 20-min long PVT inside a clinical MRI scanner during simultaneous measurements of reaction time and regional cerebral blood flow (rCBF with PCASL technique. Cognitive fatigability and neural activity during PVT were analyzed by dividing the performance and rCBF data into quintiles in addition to the assessment of self-rated fatigue before and after the PVT.ResultsThe patients showed significant fatigability during the PVT while the controls had a stable performance. The variability in performance was also significantly higher among the patients, indicating monitoring difficulty. A three-way ANOVA, modeling of the rCBF data demonstrated that there was a significant interaction effect between the subject group and performance time during PVT in a mainly frontal/thalamic network, indicating that the pattern of rCBF change for the mTBI patients differed significantly from that of healthy controls. In the mTBI patients, fatigability at the end of the PVT was related to increased rCBF in the right middle frontal gyrus, while self-rated fatigue was related to increased rCBF in left medial frontal and anterior cingulate gyri and decreases of rCBF in a frontal/thalamic network during this period.DiscussionThis study demonstrates that PCASL is a useful technique to

  16. Polio eradication in India: progress, but environmental surveillance and vigilance still needed.

    Science.gov (United States)

    Chatterjee, Animesh; Vidyant, Sanjukta; Dhole, Tapan N

    2013-02-18

    Poliomyelitis has appeared in epidemic form, become endemic on a global scale, and has been reduced to near elimination, all within the span of documented medical history. Nevertheless, effective vaccinations, global surveillance network, development of accurate viral diagnosis prompted the historical challenge, global polio eradication initiative (GPEI). Environmental surveillance of poliovirus means monitoring of wild polio virus (WPV) and vaccine derived polio virus (cVDPV) circulation in human populations by examining environmental specimens supposedly contaminated by human feces. The rationale for surveillance is based on the fact that PV-infected individuals, whether presenting with disease symptoms or not, shed large amounts of PV in the feces for several weeks. As the morbidity: infection ratio of PV infection is very low, and therefore this fact contributes to the sensitivity of poliovirus surveillance, which under optimal conditions can be better than that of the standard acute flaccid paralysis (AFP) surveillance. The World Health Organization (WHO) has included environmental surveillance of poliovirus in the new Strategic Plan of the Global Polio Eradication Initiative for years 2010-2012 to be increasingly used in PV surveillance, supplementing AFP surveillance and the strategic advisory group of experts on immunization (SAGE) recommended a switch from tOPV-bOPV to remove the threat of cVDPV2 and to accelerate the elimination of WPV type 1 and 3 as bOPV is a more immunogenic vaccine and to introduce one dose of IPV in their vaccination schedule prior to OPV cessation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Gingival bleeding, a possible "serious" adverse drug reaction: An observational study in the French PharmacoVigilance Database.

    Science.gov (United States)

    Bondon-Guitton, Emmanuelle; Mourgues, Thibaut; Rousseau, Vanessa; Cousty, Sarah; Cottin, Judith; Drablier, Guillaume; Micallef, Joëlle; Montastruc, Jean-Louis

    2017-09-01

    Antithrombotic drugs are known to increase the risk of gingival bleeding because they affect coagulation. However, other drugs could also be involved in gingival bleeding. We performed a pharmacoepidemiological study to identify the drugs most frequently "suspected" in the occurrence of gingival bleeding. We selected reports of "gingival bleeding" from 1 January 1985 to 30 September 2014 in the French PharmacoVigilance Database. Among 523,808 reports of adverse drug reactions, we identified 454 reports of gingival bleeding (0.09%). Most of them were "serious" (58.4%) and occurred in females (54.6%). The frequency of gingival bleeding increased with age. The most frequently "suspected" drugs were antithrombotics (67.8%), particularly fluindione. Other drugs frequently involved were furosemide followed by paracetamol, amiodarone, amoxicillin, paroxetine, ketoprofen, zolpidem, enalapril and ramipril. Thirty-nine reports involved a drug-drug interaction with antithrombotics, mainly with anti-infectives. Gingival bleeding can be an adverse drug reaction, often "serious" and rarely fatal. Patients older than 50 years and women are particularly at risk. Among drugs known to increase the risk of gingival bleeding, the most frequently involved were fluindione, furosemide, paracetamol, amiodarone, amoxicillin, paroxetine or ketoprofen. We also identified signal for drugs not usually known to be involved in bleeding, like zolpidem, enalapril or ramipril. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Interindividual differences in stress sensitivity: basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress.

    Science.gov (United States)

    Henckens, Marloes J A G; Klumpers, Floris; Everaerd, Daphne; Kooijman, Sabine C; van Wingen, Guido A; Fernández, Guillén

    2016-04-01

    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both basal cortisol levels and stress-induced cortisol responses predicts differences in neural vigilance processing during stress exposure. Implementing a randomized, counterbalanced, crossover design, 120 healthy male participants were exposed to a stress-induction and control procedure, followed by an emotional perception task (viewing fearful and happy faces) during fMRI scanning. Stress sensitivity was assessed using physiological (salivary cortisol levels) and psychological measures (trait questionnaires). High stress-induced cortisol responses were associated with increased stress sensitivity as assessed by psychological questionnaires, a stronger stress-induced increase in medial temporal activity and greater differential amygdala responses to fearful as opposed to happy faces under control conditions. In contrast, high basal cortisol levels were related to relative stress resilience as reflected by higher extraversion scores, a lower stress-induced increase in amygdala activity and enhanced differential processing of fearful compared with happy faces under stress. These findings seem to reflect a critical role for HPA-axis signaling in stress coping; higher basal levels indicate stress resilience, whereas higher cortisol responsivity to stress might facilitate recovery in those individuals prone to react sensitively to stress. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Evaluating the longitudinal risk of social vigilance on atherosclerosis: study protocol for the North Texas Heart Study.

    Science.gov (United States)

    Ruiz, John M; Taylor, Daniel J; Uchino, Bert N; Smith, Timothy W; Allison, Matthew; Ahn, Chul; Johnson, Jillian J; Smyth, Joshua M

    2017-08-14

    Psychosocial factors are increasingly recognised as important determinants of cardiovascular disease risk. The North Texas Heart Study aims to understand the mechanisms responsible for this association with a focus on social vigilance (ie, scanning the environment for social threats). There is also growing interest in supplementing traditional methods (eg, survey assessment of psychosocial risk paired with cross-sectional and longitudinal health outcomes) with daily or repeated momentary assessment of psychosocial factors. However, there are relatively few longitudinal studies directly comparing these approaches with hard endpoints. The North Texas Heart Study proposes a longitudinal measurement burst design to examine psychosocial determinants of subclinical atherosclerosis. A sample of 300 healthy community participants, stratified by age and gender, will complete survey measures, as well as 2 days of ecological momentary assessment at baseline and at a 2-year follow-up. A range of psychosocial and behavioural factors, objective biomarkers, as well as carotid intima-media thickness (cIMT) will be assessed at both time points. Unadjusted and adjusted models will evaluate cross-sectional associations and determinants of change in the cIMT. The Institutional Review Board at the study coordinating institute (University of North Texas) has approved this study. Positive, negative or inconclusive primary and ancillary findings will be disseminated in scientific journals and conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Occupational contact urticaria: lessons from the French National Network for Occupational Disease Vigilance and Prevention (RNV3P).

    Science.gov (United States)

    Bensefa-Colas, L; Telle-Lamberton, M; Faye, S; Bourrain, J-L; Crépy, M-N; Lasfargues, G; Choudat, D; Momas, I

    2015-12-01

    Occupational contact urticaria (OCU) is an occupational contact dermatitis that can cause serious health consequences and disability at work. To describe OCU and its temporal trends by the main causal agents and activity sectors in a nationwide scheme in France. Using data from the French National Network for Occupational Disease Vigilance and Prevention (RNV3P), we described OCU reported during the period 2001-10 and analysed the temporal trends of OCU and OCU attributed to the most frequent agents over the study period. Trends analyses were supported by reporting odds ratios using a logistic regression model with reference to 2001, or with time as a continuous variable. During the study period, 251 cases of OCU were reported in RNV3P, half of which were due to natural rubber latex, in particular in the health and social work activity sector (HSW). The number of these cases declined significantly over the study period (19% per year), and particularly after 2006. Conversely, the other causes of OCU did not decrease. Using surveillance data from a French national network, this study has found that there was a significant decline in OCU due to natural rubber latex, particularly in the HSW, when powdered latex gloves were banned from French hospitals. Our results show the effectiveness of this preventive measure, and suggest that this practice should be extended to other sectors. © 2015 British Association of Dermatologists.

  1. The neurocognitive nature of children with ADHD comorbid sluggish cognitive tempo: Might SCT be a disorder of vigilance?

    Science.gov (United States)

    Baytunca, Muharrem Burak; Inci, Sevim Berrin; Ipci, Melis; Kardas, Burcu; Bolat, Gul Unsel; Ercan, Eyup Sabri

    2018-03-21

    Sluggish Cognitive Tempo (SCT) refers to a clinical construct including several symptoms such as sluggishness, absentmindedness, low energy. In the present study, we compared neurocognitive laboratory outcomes of ADHD children with or without SCT. The CNS Vital Signs Battery was utilized to measure neurocognitive measure of the participants. The SCT+ADHD group comprised of 42 subjects, ADHD group was 41 subjects and control group was 24 subjects. The cognitive flexibility score was found to be more severely impaired in ADHD children with SCT in comparison to the ADHD-only. Additionally, greater deficits in the Shifting Attention Test (p = 0.014) and the Continuous Performance Test (reaction time score, p SCT+ADHD group relative to ADHD group. Processing speed, visual/auditory memory, psychomotor speed and reaction time were not found to more impaired in those comorbid with SCT. Impairments in the cognitive flexibility and more specifically shifting attention and continuous performance may be indicative of vigilance and orientation problems rather than executive functions for the SCT construct. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Nicotine chewing gum (2 mg, 4 mg) and cigarette smoking: comparative effects upon vigilance and heart rate.

    Science.gov (United States)

    Parrott, A C; Winder, G

    1989-01-01

    Sixteen male smokers, abstinent the morning before testing, were assessed under four conditions: placebo chewing gum, 2 mg nicotine chewing gum, 4 mg nicotine gum, and cigarette smoking. Placebo gum was administered in the cigarette condition, while sham smoking occurred in the gum conditions. Pre-drug administration and post-drug difference scores were calculated for each assessment measure: rapid visual information processing (RVIP), memory for new information, and heart rate. Nicotine raised heart rate in a significant monotonic dose-related manner (P less than 0.001): placebo +0.2; 2 mg gum +5.1; 4 mg gum +9.8; cigarette +17.5 bpm. Rapid visual information processing target detections were also significantly related to dose (P less than 0.01), with this increased vigilance significant under 4 mg nicotine gum and cigarette smoking. Memory task performance was not significantly affected. Self-reported feelings of alertness/energy were higher while smoking than under placebo or 4 mg gum. Complaints about the taste of the 4 mg nicotine gum were frequent.

  3. Towards a global system of vigilance and surveillance in unrelated donors of haematopoietic progenitor cells for transplantation.

    Science.gov (United States)

    Shaw, B E; Chapman, J; Fechter, M; Foeken, L; Greinix, H; Hwang, W; Phillips-Johnson, L; Korhonen, M; Lindberg, B; Navarro, W H; Szer, J

    2013-11-01

    Safety of living donors is critical to the success of blood, tissue and organ transplantation. Structured and robust vigilance and surveillance systems exist as part of some national entities, but historically no global systems are in place to ensure conformity, harmonisation and the recognition of rare adverse events (AEs). The World Health Assembly has recently resolved to require AE/reaction (AE/R) reporting both nationally and globally. The World Marrow Donor Association (WMDA) is an international organisation promoting the safety of unrelated donors and progenitor cell products for use in haematopoietic progenitor cell (HPC) transplantation. To address this issue, we established a system for collecting, collating, analysing, distributing and reacting to serious adverse events and reactions (SAE/R) in unrelated HPC donors. The WMDA successfully instituted this reporting system with 203 SAE/R reported in 2011. The committee generated two rapid reports, reacting to specific SAE/R, resulting in practice changing policies. The system has a robust governance structure, formal feedback to the WMDA membership and transparent information flows to other agencies, specialist physicians and transplant programs and the general public.

  4. The thalamo-cortical auditory receptive fields: regulation by the states of vigilance, learning and the neuromodulatory systems.

    Science.gov (United States)

    Edeline, Jean-Marc

    2003-12-01

    The goal of this review is twofold. First, it aims to describe the dynamic regulation that constantly shapes the receptive fields (RFs) and maps in the thalamo-cortical sensory systems of undrugged animals. Second, it aims to discuss several important issues that remain unresolved at the intersection between behavioral neurosciences and sensory physiology. A first section presents the RF modulations observed when an undrugged animal spontaneously shifts from waking to slow-wave sleep or to paradoxical sleep (also called REM sleep). A second section shows that, in contrast with the general changes described in the first section, behavioral training can induce selective effects which favor the stimulus that has acquired significance during learning. A third section reviews the effects triggered by two major neuromodulators of the thalamo-cortical system--acetylcholine and noradrenaline--which are traditionally involved both in the switch of vigilance states and in learning experiences. The conclusion argues that because the receptive fields and maps of an awake animal are continuously modulated from minute to minute, learning-induced sensory plasticity can be viewed as a "crystallization" of the receptive fields and maps in one of the multiple possible states. Studying the interplays between neuromodulators can help understanding the neurobiological foundations of this dynamic regulation.

  5. A comparison of the effects of transcranial direct current stimulation and caffeine on vigilance and cognitive performance during extended wakefulness.

    Science.gov (United States)

    McIntire, Lindsey K; McKinley, R Andy; Goodyear, Chuck; Nelson, Justin

    2014-01-01

    Sleep deprivation from extended duty hours is a common complaint for many occupations. Caffeine is one of the most common countermeasures used to combat fatigue. However, the benefits of caffeine decline over time and with chronic use. Our objective was to evaluate the efficacy of anodal transcranial direct current stimulation (tDCS) applied to the pre-frontal cortex at 2 mA for 30 min to remediate the effects of sleep deprivation and to compare the behavioral effects of tDCS with those of caffeine. Three groups of 10 participants each received either active tDCS with placebo gum, caffeine gum with sham tDCS, or sham tDCS with placebo gum during 30 h of extended wakefulness. Our results show that tDCS prevented a decrement in vigilance and led to better subjective ratings for fatigue, drowsiness, energy, and composite mood compared to caffeine and control in sleep-deprived individuals. Both the tDCS and caffeine produced similar improvements in latencies on a short-term memory task and faster reaction times in a psychomotor task when compared to the placebo group. Interestingly, changes in accuracy for the tDCS group were not correlated to changes in mood; whereas, there was a relationship for the caffeine and sham groups. Our data suggest that tDCS could be a useful fatigue countermeasure and may be more beneficial than caffeine since boosts in performance and mood last several hours. Published by Elsevier Inc.

  6. A inserção da vigilância em saúde ambiental no sistema único de saúde

    OpenAIRE

    Edenilo Baltazar Barreira Filho; José Ricardo Soares Pontes

    2012-01-01

    A inserção das atividades de vigilância ambiental no SUS apresenta algumas características que se diferenciam das práticas de vigilância epidemiológica. Isto ocorre principalmente em decorrência de que muitos dados sobre a exposição aos fatores ambientais são obtidos fora do setor saúde e a adoção de ações que busquem controlar e/ou prevenir exigem, na grande maioria dos casos, uma compreensãoe articulação intra e intersetorial, pois o setor saúde não é capaz de, sozinho, dar respostas as que...

  7. Los aspectos ideológicos-pedagógicos del proyecto del «Instituto Secundario C. C. Vigil» (1970-1977

    Directory of Open Access Journals (Sweden)

    María Luz Prados

    2017-01-01

    Full Text Available En el presente artículo se analizan los aspectos ideológico-pedagógicos del proyecto político-pedagógico del Instituto Secundario C. C. Vigil. Tal proyecto formó parte del complejo institucional de lo que fuera la Biblioteca Constancio C. Vigil (1959-1977, emblemática entidad de la ciudad de Rosario que llevó adelante un proyecto cultural, social, pedagógico y mutual en uno de sus barrios populares: el barrio Tablada. Esta entidad fue víctima del terrorismo de Estado y, específicamente, de la política educativa procesista (Kaufmann, 2006 desplegada durante la última dictadura cívico-militar (1976-1983 sufriendo una intervención militar en el año 1977 que puso fin a toda su labor.

  8. Impact of overnight traffic noise on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers: Results of a pilot study

    Directory of Open Access Journals (Sweden)

    Roland FJ Popp

    2015-01-01

    Full Text Available This study aimed to evaluate the impact of traffic noise along the motorway on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers. This was a randomized, crossover, within-subject controlled study. Healthy long-haul truck drivers spent 6 consecutive nights in a real truck berth with full sleep laboratory equipment. During 3 nights, subjects were exposed to replayed traffic noise alongside motorways, whereas the other 3 nights were without traffic noise. Polysomnography was recorded during the nights and numerous sleepiness tests and vigilance examinations were performed during the following standardized working day. Outcome measures were compared between noisy and silent nights using the paired Wilcoxon test. Ten healthy long-haul truck drivers with a mean age of 36.3 ± 7.3 years completed the study as planned. On noisy nights, subjects had greater latencies to the rapid eye movement (REM phase (90 ± 32 min vs 69 ± 16 min, P = 0.074 and higher percentages of sleep stage 1 (13.7 ± 5.5% vs 11.2 ± 4.4%; P = 0.059. Subjects also rated their sleep quality as having been better during nights without noise (28.1 ± 3.7 vs 30.3 ± 6.2, P = 0.092. The impact of these differences on daytime sleepiness and vigilance was rather low; however, mean Karolinska Sleepiness Scale (KSS scores measured during the course of the following day were higher on six out of eight occasions after noisy nights. The effects of overnight traffic noise on sleep quality are detectable but unlikely to have any major impact on the vigilant attention and driving performance of long haul-truck drivers with low nocturnal noise sensitivity. This might not be true for subgroups prone to sleeping disorders.

  9. Impact of overnight traffic noise on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers: Results of a pilot study.

    Science.gov (United States)

    Popp, Roland Fj; Maier, Stefanie; Rothe, Siegfried; Zulley, Jürgen; Crönlein, Tatjana; Wetter, Thomas C; Rupprecht, Rainer; Hajak, Göran

    2015-01-01

    This study aimed to evaluate the impact of traffic noise along the motorway on sleep quality, sleepiness, and vigilant attention in long-haul truck drivers. This was a randomized, crossover, within-subject controlled study. Healthy long-haul truck drivers spent 6 consecutive nights in a real truck berth with full sleep laboratory equipment. During 3 nights, subjects were exposed to replayed traffic noise alongside motorways, whereas the other 3 nights were without traffic noise. Polysomnography was recorded during the nights and numerous sleepiness tests and vigilance examinations were performed during the following standardized working day. Outcome measures were compared between noisy and silent nights using the paired Wilcoxon test. Ten healthy long-haul truck drivers with a mean age of 36.3 ± 7.3 years completed the study as planned. On noisy nights, subjects had greater latencies to the rapid eye movement (REM) phase (90 ± 32 min vs 69 ± 16 min, P = 0.074) and higher percentages of sleep stage 1 (13.7 ± 5.5% vs 11.2 ± 4.4%; P = 0.059). Subjects also rated their sleep quality as having been better during nights without noise (28.1 ± 3.7 vs 30.3 ± 6.2, P = 0.092). The impact of these differences on daytime sleepiness and vigilance was rather low; however, mean Karolinska Sleepiness Scale (KSS) scores measured during the course of the following day were higher on six out of eight occasions after noisy nights. The effects of overnight traffic noise on sleep quality are detectable but unlikely to have any major impact on the vigilant attention and driving performance of long haul-truck drivers with low nocturnal noise sensitivity. This might not be true for subgroups prone to sleeping disorders.

  10. Attention/vigilance in schizophrenia: performance results from a large multi-site study of the Consortium on the Genetics of Schizophrenia (COGS).

    Science.gov (United States)

    Nuechterlein, Keith H; Green, Michael F; Calkins, Monica E; Greenwood, Tiffany A; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Light, Gregory A; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

    2015-04-01

    Attention/vigilance impairments are present in individuals with schizophrenia across psychotic and remitted states and in their first-degree relatives. An important question is whether deficits in attention/vigilance can be consistently and reliably measured across sites varying in many participant demographic, clinical, and functional characteristics, as needed for large-scale genetic studies of endophenotypes. We examined Continuous Performance Test (CPT) data from phase 2 of the Consortium on the Genetics of Schizophrenia (COGS-2), the largest-scale assessment of cognitive and psychophysiological endophenotypes relevant to schizophrenia. The CPT data from 2251 participants from five sites were examined. A perceptual-load vigilance task (the Degraded Stimulus CPT or DS-CPT) and a memory-load vigilance task (CPT-Identical Pairs or CPT-IP) were utilized. Schizophrenia patients performed more poorly than healthy comparison subjects (HCS) across sites, despite significant site differences in participant age, sex, education, and racial distribution. Patient-HCS differences in signal/noise discrimination (d') in the DS-CPT varied significantly across sites, but averaged a medium effect size. CPT-IP performance showed large patient-HCS differences across sites. Poor CPT performance was independent of or weakly correlated with symptom severity, but was significantly associated with lower educational achievement and functional capacity. Current smoking was associated with poorer CPT-IP d'. Patients taking both atypical and typical antipsychotic medication performed more poorly than those on no or atypical antipsychotic medications, likely reflecting their greater severity of illness. We conclude that CPT deficits in schizophrenia can be reliably detected across sites, are relatively independent of current symptom severity, and are related to functional capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Representações sociais dos conselheiros municipais de saúde sobre a vigilância sanitária

    Directory of Open Access Journals (Sweden)

    Ana Maria Caldeira Oliveira

    2015-08-01

    Full Text Available ResumoO objetivo do estudo é descrever e analisar as representações sociais dos Conselheiros de Saúde de Belo Horizonte sobre suas experiências com a vigilância sanitária. A pesquisa utilizou a técnica de entrevista baseada em roteiro semiestruturado. Os dados obtidos foram analisados pela técnica do Discurso do Sujeito Coletivo. Verificou-se que o distanciamento existente entre a vigilância sanitária e o Conselho Municipal de Saúde é compensado pela riqueza das experiências “vividas” dos conselheiros. Essas experiências foram ressignificadas em saber prático, influenciando diretamente o pensamento e o conhecimento desses sujeitos sobre o tema. Por fim, a comprovação da apropriação social sobre a importância da vigilância sanitária como ação de saúde a qualifica como eficaz modelo de atenção à saúde, intervindo sobre os fatores determinantes e condicionantes do processo saúde doença, ao mesmo tempo em que promove ações educativas que contribuem para elevar a consciência sanitária.

  12. Review of declarations received by the AFSSAPS and the ASN on the account of radio-vigilance (external radiotherapy). July 2007 - June 2008

    International Nuclear Information System (INIS)

    2009-09-01

    After a presentation of the procedure of declaration of significant radiation protection events, of the ASN-SFRO event scale, and of the indication procedure related to material vigilance, this report proposes a review and an analysis of significant radioprotection and material vigilance events which have been declared between July 2007 and June 2008. The assessment of radiation protection events declared to the ASN is as well quantitative (distribution in time, geographical distribution, status of declaring centres, declaration delays, classification according to the ASN-SFRO scale) as qualitative (origin, event typology, stage of the treatment process at which the event occurred and has been detected, personnel having detected the event, communication about events). The analysis of material vigilance events addresses the evolution of their number, their distribution in terms of declarer type, of radiotherapy equipment, or of criticality level, and so on. A review of hybrid accidents is proposed (concerned equipment, declarer origin, consequences of the declarations, classification on the ASN-SFRO scale)

  13. Men’s Perception of Raped Women: Test of the Sexually Transmitted Disease Hypothesis and the Cuckoldry Hypothesis

    Directory of Open Access Journals (Sweden)

    Prokop Pavol

    2016-06-01

    Full Text Available Rape is a recurrent adaptive problem of female humans and females of a number of non-human animals. Rape has various physiological and reproductive costs to the victim. The costs of rape are furthermore exaggerated by social rejection and blaming of a victim, particularly by men. The negative perception of raped women by men has received little attention from an evolutionary perspective. Across two independent studies, we investigated whether the risk of sexually transmitted diseases (the STD hypothesis, Hypothesis 1 or paternity uncertainty (the cuckoldry hypothesis, Hypothesis 2 influence the negative perception of raped women by men. Raped women received lower attractiveness score than non-raped women, especially in long-term mate attractiveness score. The perceived attractiveness of raped women was not influenced by the presence of experimentally manipulated STD cues on faces of putative rapists. Women raped by three men received lower attractiveness score than women raped by one man. These results provide stronger support for the cuckoldry hypothesis (Hypothesis 2 than for the STD hypothesis (Hypothesis 1. Single men perceived raped women as more attractive than men in a committed relationship (Hypothesis 3, suggesting that the mating opportunities mediate men’s perception of victims of rape. Overall, our results suggest that the risk of cuckoldry underlie the negative perception of victims of rape by men rather than the fear of disease transmission.

  14. New Hypothesis for SOFC Ceramic Oxygen Electrode Mechanisms

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Chatzichristodoulou, Christodoulos; Graves, Christopher R.

    2016-01-01

    A new hypothesis for the electrochemical reaction mechanism in solid oxide cell ceramic oxygen electrodes is proposed based on literature including our own results. The hypothesis postulates that the observed thin layers of SrO-La2O3 on top of ceramic perovskite and other Ruddlesden-Popper...

  15. Assess the Critical Period Hypothesis in Second Language Acquisition

    Science.gov (United States)

    Du, Lihong

    2010-01-01

    The Critical Period Hypothesis aims to investigate the reason for significant difference between first language acquisition and second language acquisition. Over the past few decades, researchers carried out a series of studies to test the validity of the hypothesis. Although there were certain limitations in these studies, most of their results…

  16. Dynamical agents' strategies and the fractal market hypothesis

    Czech Academy of Sciences Publication Activity Database

    Vácha, Lukáš; Vošvrda, Miloslav

    2005-01-01

    Roč. 14, č. 2 (2005), s. 172-179 ISSN 1210-0455 Grant - others:GA UK(CZ) 454/2004/A EK/FSV Institutional research plan: CEZ:AV0Z10750506 Keywords : efficient market hypothesis * fractal market hypothesis * agent's investment horizons Subject RIV: AH - Economics

  17. An Exercise for Illustrating the Logic of Hypothesis Testing

    Science.gov (United States)

    Lawton, Leigh

    2009-01-01

    Hypothesis testing is one of the more difficult concepts for students to master in a basic, undergraduate statistics course. Students often are puzzled as to why statisticians simply don't calculate the probability that a hypothesis is true. This article presents an exercise that forces students to lay out on their own a procedure for testing a…

  18. A default Bayesian hypothesis test for ANOVA designs

    NARCIS (Netherlands)

    Wetzels, R.; Grasman, R.P.P.P.; Wagenmakers, E.J.

    2012-01-01

    This article presents a Bayesian hypothesis test for analysis of variance (ANOVA) designs. The test is an application of standard Bayesian methods for variable selection in regression models. We illustrate the effect of various g-priors on the ANOVA hypothesis test. The Bayesian test for ANOVA

  19. Adaptation hypothesis of biological efficiency of ionizing radiation

    International Nuclear Information System (INIS)

    Kudritskij, Yu.K.; Georgievskij, A.B.; Karpov, V.I.

    1992-01-01

    Adaptation hypothesis of biological efficiency of ionizing radiation is based on acknowledgement of invariance of fundamental laws and principles of biology related to unity of biota and media, evolution and adaptation for radiobiology. The basic arguments for adaptation hypothesis validity, its correspondence to the requirements imposed on scientific hypothes are presented

  20. New methods of testing nonlinear hypothesis using iterative NLLS estimator

    Science.gov (United States)

    Mahaboob, B.; Venkateswarlu, B.; Mokeshrayalu, G.; Balasiddamuni, P.

    2017-11-01

    This research paper discusses the method of testing nonlinear hypothesis using iterative Nonlinear Least Squares (NLLS) estimator. Takeshi Amemiya [1] explained this method. However in the present research paper, a modified Wald test statistic due to Engle, Robert [6] is proposed to test the nonlinear hypothesis using iterative NLLS estimator. An alternative method for testing nonlinear hypothesis using iterative NLLS estimator based on nonlinear hypothesis using iterative NLLS estimator based on nonlinear studentized residuals has been proposed. In this research article an innovative method of testing nonlinear hypothesis using iterative restricted NLLS estimator is derived. Pesaran and Deaton [10] explained the methods of testing nonlinear hypothesis. This paper uses asymptotic properties of nonlinear least squares estimator proposed by Jenrich [8]. The main purpose of this paper is to provide very innovative methods of testing nonlinear hypothesis using iterative NLLS estimator, iterative NLLS estimator based on nonlinear studentized residuals and iterative restricted NLLS estimator. Eakambaram et al. [12] discussed least absolute deviation estimations versus nonlinear regression model with heteroscedastic errors and also they studied the problem of heteroscedasticity with reference to nonlinear regression models with suitable illustration. William Grene [13] examined the interaction effect in nonlinear models disused by Ai and Norton [14] and suggested ways to examine the effects that do not involve statistical testing. Peter [15] provided guidelines for identifying composite hypothesis and addressing the probability of false rejection for multiple hypotheses.

  1. The Younger Dryas impact hypothesis: A critical review

    NARCIS (Netherlands)

    van Hoesel, A.; Hoek, W.Z.; Pennock, G.M.; Drury, Martyn

    2014-01-01

    The Younger Dryas impact hypothesis suggests that multiple extraterrestrial airbursts or impacts resulted in the Younger Dryas cooling, extensive wildfires, megafaunal extinctions and changes in human population. After the hypothesis was first published in 2007, it gained much criticism, as the

  2. PC-PVT 2.0: An updated platform for psychomotor vigilance task testing, analysis, prediction, and visualization.

    Science.gov (United States)

    Reifman, Jaques; Kumar, Kamal; Khitrov, Maxim Y; Liu, Jianbo; Ramakrishnan, Sridhar

    2018-07-01

    The psychomotor vigilance task (PVT) has been widely used to assess the effects of sleep deprivation on human neurobehavioral performance. To facilitate research in this field, we previously developed the PC-PVT, a freely available software system analogous to the "gold-standard" PVT-192 that, in addition to allowing for simple visual reaction time (RT) tests, also allows for near real-time PVT analysis, prediction, and visualization in a personal computer (PC). Here we present the PC-PVT 2.0 for Windows 10 operating system, which has the capability to couple PVT tests of a study protocol with the study's sleep/wake and caffeine schedules, and make real-time individualized predictions of PVT performance for such schedules. We characterized the accuracy and precision of the software in measuring RT, using 44 distinct combinations of PC hardware system configurations. We found that 15 system configurations measured RTs with an average delay of less than 10 ms, an error comparable to that of the PVT-192. To achieve such small delays, the system configuration should always use a gaming mouse as the means to respond to visual stimuli. We recommend using a discrete graphical processing unit for desktop PCs and an external monitor for laptop PCs. This update integrates a study's sleep/wake and caffeine schedules with the testing software, facilitating testing and outcome visualization, and provides near-real-time individualized PVT predictions for any sleep-loss condition considering caffeine effects. The software, with its enhanced PVT analysis, visualization, and prediction capabilities, can be freely downloaded from https://pcpvt.bhsai.org. Published by Elsevier B.V.

  3. In-flight sleep, pilot fatigue and Psychomotor Vigilance Task performance on ultra-long range versus long range flights.

    Science.gov (United States)

    Gander, Philippa H; Signal, T Leigh; van den Berg, Margo J; Mulrine, Hannah M; Jay, Sarah M; Jim Mangie, Captain

    2013-12-01

    This study evaluated whether pilot fatigue was greater on ultra-long range (ULR) trips (flights >16 h on 10% of trips in a 90-day period) than on long range (LR) trips. The within-subjects design controlled for crew complement, pattern of in-flight breaks, flight direction and departure time. Thirty male Captains (mean age = 54.5 years) and 40 male First officers (mean age = 48.0 years) were monitored on commercial passenger flights (Boeing 777 aircraft). Sleep was monitored (actigraphy, duty/sleep diaries) from 3 days before the first study trip to 3 days after the second study trip. Karolinska Sleepiness Scale, Samn-Perelli fatigue ratings and a 5-min Psychomotor Vigilance Task were completed before, during and after every flight. Total sleep in the 24 h before outbound flights and before inbound flights after 2-day layovers was comparable for ULR and LR flights. All pilots slept on all flights. For each additional hour of flight time, they obtained an estimated additional 12.3 min of sleep. Estimated mean total sleep was longer on ULR flights (3 h 53 min) than LR flights (3 h 15 min; P(F) = 0.0004). Sleepiness ratings were lower and mean reaction speed was faster at the end of ULR flights. Findings suggest that additional in-flight sleep mitigated fatigue effectively on longer flights. Further research is needed to clarify the contributions to fatigue of in-flight sleep versus time awake at top of descent. The study design was limited to eastward outbound flights with two Captains and two First Officers. Caution must be exercised when extrapolating to different operations. © 2013 European Sleep Research Society.

  4. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task.

    Science.gov (United States)

    Foxe, John J; Morie, Kristen P; Laud, Peter J; Rowson, Matthew J; de Bruin, Eveline A; Kelly, Simon P

    2012-06-01

    Caffeine and L-theanine, both naturally occurring in tea, affect the ability to make rapid phasic deployments of attention to locations in space as reflected in behavioural performance and alpha-band oscillatory brain activity (8-14 Hz). However, surprisingly little is known about how these compounds affect an aspect of attention that has been more popularly associated with tea, namely vigilant attention: the ability to maintain focus on monotonous tasks over protracted time-periods. Twenty-seven participants performed the Sustained Attention to Response Task (SART) over a two-hour session on each of four days, on which they were administered caffeine (50 mg), theanine (100 mg), the combination, or placebo in a double-blind, randomized, cross-over fashion. Concurrently, we recorded oscillatory brain activity through high-density electroencephalography (EEG). We asked whether either compound alone, or both in combination, would affect performance of the task in terms of reduced error rates over time, and whether changes in alpha-band activity would show a relationship to such changes in performance. When treated with placebo, participants showed a rise in error rates, a pattern that is commonly observed with increasing time-on-task, whereas after caffeine and theanine ingestion, error rates were significantly reduced. The combined treatment did not confer any additional benefits over either compound alone, suggesting that the individual compounds may confer maximal benefits at the dosages employed. Alpha-band oscillatory activity was significantly reduced on ingestion of caffeine, particularly in the first hour. This effect was not changed by addition of theanine in the combined treatment. Theanine alone did not affect alpha-band activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Sliding-window analysis tracks fluctuations in amygdala functional connectivity associated with physiological arousal and vigilance during fear conditioning.

    Science.gov (United States)

    Baczkowski, Blazej M; Johnstone, Tom; Walter, Henrik; Erk, Susanne; Veer, Ilya M

    2017-06-01

    We evaluated whether sliding-window analysis can reveal functionally relevant brain network dynamics during a well-established fear conditioning paradigm. To this end, we tested if fMRI fluctuations in amygdala functional connectivity (FC) can be related to task-induced changes in physiological arousal and vigilance, as reflected in the skin conductance level (SCL). Thirty-two healthy individuals participated in the study. For the sliding-window analysis we used windows that were shifted by one volume at a time. Amygdala FC was calculated for each of these windows. Simultaneously acquired SCL time series were averaged over time frames that corresponded to the sliding-window FC analysis, which were subsequently regressed against the whole-brain seed-based amygdala sliding-window FC using the GLM. Surrogate time series were generated to test whether connectivity dynamics could have occurred by chance. In addition, results were contrasted against static amygdala FC and sliding-window FC of the primary visual cortex, which was chosen as a control seed, while a physio-physiological interaction (PPI) was performed as cross-validation. During periods of increased SCL, the left amygdala became more strongly coupled with the bilateral insula and anterior cingulate cortex, core areas of the salience network. The sliding-window analysis yielded a connectivity pattern that was unlikely to have occurred by chance, was spatially distinct from static amygdala FC and from sliding-window FC of the primary visual cortex, but was highly comparable to that of the PPI analysis. We conclude that sliding-window analysis can reveal functionally relevant fluctuations in connectivity in the context of an externally cued task. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Environmental policy without costs? A review of the Porter hypothesis

    Energy Technology Data Exchange (ETDEWEB)

    Braennlund, Runar; Lundgren, Tommy. e-mail: runar.brannlund@econ.umu.se

    2009-03-15

    This paper reviews the theoretical and empirical literature connected to the so called Porter Hypothesis. That is, to review the literature connected to the discussion about the relation between environmental policy and competitiveness. According to the conventional wisdom environmental policy, aiming for improving the environment through for example emission reductions, do imply costs since scarce resources must be diverted from somewhere else. However, this conventional wisdom has been challenged and questioned recently through what has been denoted the 'Porter hypothesis'. Those in the forefront of the Porter hypothesis challenge the conventional wisdom basically on the ground that resources are used inefficiently in the absence of the right kind of environmental regulations, and that the conventional neo-classical view is too static to take inefficiencies into account. The conclusions that can be made from this review is (1) that the theoretical literature can identify the circumstances and mechanisms that must exist for a Porter effect to occur, (2) that these circumstances are rather non-general, hence rejecting the Porter hypothesis in general, (3) that the empirical literature give no general support for the Porter hypothesis. Furthermore, a closer look at the 'Swedish case' reveals no support for the Porter hypothesis in spite of the fact that Swedish environmental policy the last 15-20 years seems to be in line the prerequisites stated by the Porter hypothesis concerning environmental policy

  7. The linear hypothesis - an idea whose time has passed

    International Nuclear Information System (INIS)

    Tschaeche, A.N.

    1995-01-01

    The linear no-threshold hypothesis is the basis for radiation protection standards in the United States. In the words of the National Council on Radiation Protection and Measurements (NCRP), the hypothesis is: open-quotes In the interest of estimating effects in humans conservatively, it is not unreasonable to follow the assumption of a linear relationship between dose and effect in the low dose regions for which direct observational data are not available.close quotes The International Commission on Radiological Protection (ICRP) stated the hypothesis in a slightly different manner: open-quotes One such basic assumption ... is that ... there is ... a linear relationship without threshold between dose and the probability of an effect. The hypothesis was necessary 50 yr ago when it was first enunciated because the dose-effect curve for ionizing radiation for effects in humans was not known. The ICRP and NCRP needed a model to extrapolate high-dose effects to low-dose effects. So the linear no-threshold hypothesis was born. Certain details of the history of the development and use of the linear hypothesis are presented. In particular, use of the hypothesis by the U.S. regulatory agencies is examined. Over time, the sense of the hypothesis has been corrupted. The corruption of the hypothesis into the current paradigm of open-quote a little radiation, no matter how small, can and will harm youclose quotes is presented. The reasons the corruption occurred are proposed. The effects of the corruption are enumerated, specifically, the use of the corruption by the antinuclear forces in the United States and some of the huge costs to U.S. taxpayers due to the corruption. An alternative basis for radiation protection standards to assure public safety, based on the weight of scientific evidence on radiation health effects, is proposed

  8. Phi index: a new metric to test the flush early and avoid the rush hypothesis.

    Directory of Open Access Journals (Sweden)

    Diogo S M Samia

    Full Text Available Optimal escape theory states that animals should counterbalance the costs and benefits of flight when escaping from a potential predator. However, in apparent contradiction with this well-established optimality model, birds and mammals generally initiate escape soon after beginning to monitor an approaching threat, a phenomena codified as the "Flush Early and Avoid the Rush" (FEAR hypothesis. Typically, the FEAR hypothesis is tested using correlational statistics and is supported when there is a strong relationship between the distance at which an individual first responds behaviorally to an approaching predator (alert distance, AD, and its flight initiation distance (the distance at which it flees the approaching predator, FID. However, such correlational statistics are both inadequate to analyze relationships constrained by an envelope (such as that in the AD-FID relationship and are sensitive to outliers with high leverage, which can lead one to erroneous conclusions. To overcome these statistical concerns we develop the phi index (Φ, a distribution-free metric to evaluate the goodness of fit of a 1:1 relationship in a constraint envelope (the prediction of the FEAR hypothesis. Using both simulation and empirical data, we conclude that Φ is superior to traditional correlational analyses because it explicitly tests the FEAR prediction, is robust to outliers, and it controls for the disproportionate influence of observations from large predictor values (caused by the constrained envelope in AD-FID relationship. Importantly, by analyzing the empirical data we corroborate the strong effect that alertness has on flight as stated by the FEAR hypothesis.

  9. Comment rester vigilant face à l’oubli ? Le musée de la fonderie à Rosières. How to remain vigilant against forgetting ? Rosières’s foundry museum.

    Directory of Open Access Journals (Sweden)

    Guillaume ETIENNE

    2011-12-01

    Full Text Available La mise en exposition d’objets liés au travail dépasse largement la simple présentation au public d’un savoir-faire ou d’une technique. Dans cette cité ouvrière du département du Cher, dans le centre de la France, les objets exposés au musée de la Fonderie semblent donner au visiteur bien plus qu’une vision générale du travail de la fonte. A travers l’analyse de la création de ce musée, de la mise en place d’un véritable réseau de vigilance contre la perte, et de l’exposition qui laisse transparaitre bien plus que des outils de travail, nous envisagerons ici le musée de la fonderie comme un microcosme d’une vie sociale aujourd’hui révolue, indissociable de l’usine et du paternalisme industriel qui a géré la vie des salariés pendant près d’un siècle et demi.More and more museums are dedicated to local histories of work and labour, displaying industrial artefacts and objects directly taken from the work place. In such museums, the visitors do not only get a chance to discover specific techniques and savoir-faire. The purpose is also to expose them to a much encompassing cultural experience. In the local museum of Rosières, a small industrial town located in the centre of France, the visitors are offered much more than the possibility to get a grasp of the smelting work itself, which we demonstrate through an analysis of the history of this museum, of the content of its permanent exhibition, and of a network of individuals who try to keep the industrial memory of this area alive. This museum indeed appears to function as a microcosm of a social life that no longer exists, and that was strongly connected to the factory life and the industrial plant as well as industrial paternalism that ruled the workers’ lives during almost one and a half century.

  10. Null but not void: considerations for hypothesis testing.

    Science.gov (United States)

    Shaw, Pamela A; Proschan, Michael A

    2013-01-30

    Standard statistical theory teaches us that once the null and alternative hypotheses have been defined for a parameter, the choice of the statistical test is clear. Standard theory does not teach us how to choose the null or alternative hypothesis appropriate to the scientific question of interest. Neither does it tell us that in some cases, depending on which alternatives are realistic, we may want to define our null hypothesis differently. Problems in statistical practice are frequently not as pristinely summarized as the classic theory in our textbooks. In this article, we present examples in statistical hypothesis testing in which seemingly simple choices are in fact rich with nuance that, when given full consideration, make the choice of the right hypothesis test much less straightforward. Published 2012. This article is a US Government work and is in the public domain in the USA.

  11. Alzheimer's disease: the amyloid hypothesis and the Inverse Warburg effect

    KAUST Repository

    Demetrius, Lloyd A.; Magistretti, Pierre J.; Pellerin, Luc

    2015-01-01

    Epidemiological and biochemical studies show that the sporadic forms of Alzheimer's disease (AD) are characterized by the following hallmarks: (a) An exponential increase with age; (b) Selective neuronal vulnerability; (c) Inverse cancer comorbidity. The present article appeals to these hallmarks to evaluate and contrast two competing models of AD: the amyloid hypothesis (a neuron-centric mechanism) and the Inverse Warburg hypothesis (a neuron-astrocytic mechanism). We show that these three hallmarks of AD conflict with the amyloid hypothesis, but are consistent with the Inverse Warburg hypothesis, a bioenergetic model which postulates that AD is the result of a cascade of three events—mitochondrial dysregulation, metabolic reprogramming (the Inverse Warburg effect), and natural selection. We also provide an explanation for the failures of the clinical trials based on amyloid immunization, and we propose a new class of therapeutic strategies consistent with the neuroenergetic selection model.

  12. Cross-system log file analysis for hypothesis testing

    NARCIS (Netherlands)

    Glahn, Christian

    2008-01-01

    Glahn, C. (2008). Cross-system log file analysis for hypothesis testing. Presented at Empowering Learners for Lifelong Competence Development: pedagogical, organisational and technological issues. 4th TENCompetence Open Workshop. April, 10, 2008, Madrid, Spain.

  13. Hypothesis Testing Using the Films of the Three Stooges

    Science.gov (United States)

    Gardner, Robert; Davidson, Robert

    2010-01-01

    The use of The Three Stooges' films as a source of data in an introductory statistics class is described. The Stooges' films are separated into three populations. Using these populations, students may conduct hypothesis tests with data they collect.

  14. Incidence of allergy and atopic disorders and hygiene hypothesis.

    Czech Academy of Sciences Publication Activity Database

    Bencko, V.; Šíma, Petr

    2017-01-01

    Roč. 2, 6 March (2017), č. článku 1244. ISSN 2474-1663 Institutional support: RVO:61388971 Keywords : allergy disorders * atopic disorders * hygiene hypothesis Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology

  15. Alzheimer's disease: the amyloid hypothesis and the Inverse Warburg effect

    KAUST Repository

    Demetrius, Lloyd A.

    2015-01-14

    Epidemiological and biochemical studies show that the sporadic forms of Alzheimer\\'s disease (AD) are characterized by the following hallmarks: (a) An exponential increase with age; (b) Selective neuronal vulnerability; (c) Inverse cancer comorbidity. The present article appeals to these hallmarks to evaluate and contrast two competing models of AD: the amyloid hypothesis (a neuron-centric mechanism) and the Inverse Warburg hypothesis (a neuron-astrocytic mechanism). We show that these three hallmarks of AD conflict with the amyloid hypothesis, but are consistent with the Inverse Warburg hypothesis, a bioenergetic model which postulates that AD is the result of a cascade of three events—mitochondrial dysregulation, metabolic reprogramming (the Inverse Warburg effect), and natural selection. We also provide an explanation for the failures of the clinical trials based on amyloid immunization, and we propose a new class of therapeutic strategies consistent with the neuroenergetic selection model.

  16. The Double-Deficit Hypothesis in Spanish Developmental Dyslexia

    Science.gov (United States)

    Jimenez, Juan E.; Hernandez-Valle, Isabel; Rodriguez, Cristina; Guzman, Remedios; Diaz, Alicia; Ortiz, Rosario

    2008-01-01

    The double-deficit hypothesis (DDH) of developmental dyslexia was investigated in seven to twelve year old Spanish children. It was observed that the double deficit (DD) group had the greatest difficulty with reading.

  17. SETI in vivo: testing the we-are-them hypothesis

    Science.gov (United States)

    Makukov, Maxim A.; Shcherbak, Vladimir I.

    2018-04-01

    After it was proposed that life on Earth might descend from seeding by an earlier extraterrestrial civilization motivated to secure and spread life, some authors noted that this alternative offers a testable implication: microbial seeds could be intentionally supplied with a durable signature that might be found in extant organisms. In particular, it was suggested that the optimal location for such an artefact is the genetic code, as the least evolving part of cells. However, as the mainstream view goes, this scenario is too speculative and cannot be meaningfully tested because encoding/decoding a signature within the genetic code is something ill-defined, so any retrieval attempt is doomed to guesswork. Here we refresh the seeded-Earth hypothesis in light of recent observations, and discuss the motivation for inserting a signature. We then show that `biological SETI' involves even weaker assumptions than traditional SETI and admits a well-defined methodological framework. After assessing the possibility in terms of molecular and evolutionary biology, we formalize the approach and, adopting the standard guideline of SETI that encoding/decoding should follow from first principles and be convention-free, develop a universal retrieval strategy. Applied to the canonical genetic code, it reveals a non-trivial precision structure of interlocked logical and numerical attributes of systematic character (previously we found these heuristically). To assess this result in view of the initial assumption, we perform statistical, comparison, interdependence and semiotic analyses. Statistical analysis reveals no causal connection of the result to evolutionary models of the genetic code, interdependence analysis precludes overinterpretation, and comparison analysis shows that known variations of the code lack any precision-logic structures, in agreement with these variations being post-LUCA (i.e. post-seeding) evolutionary deviations from the canonical code. Finally, semiotic

  18. The Random-Walk Hypothesis on the Indian Stock Market

    OpenAIRE

    Ankita Mishra; Vinod Mishra; Russell Smyth

    2014-01-01

    This study tests the random walk hypothesis for the Indian stock market. Using 19 years of monthly data on six indices from the National Stock Exchange (NSE) and the Bombay Stock Exchange (BSE), this study applies three different unit root tests with two structural breaks to analyse the random walk hypothesis. We find that unit root tests that allow for two structural breaks alone are not able to reject the unit root null; however, a recently developed unit root test that simultaneously accou...

  19. The Fractal Market Hypothesis: Applications to Financial Forecasting

    OpenAIRE

    Blackledge, Jonathan

    2010-01-01

    Most financial modelling systems rely on an underlying hypothesis known as the Efficient Market Hypothesis (EMH) including the famous Black-Scholes formula for placing an option. However, the EMH has a fundamental flaw: it is based on the assumption that economic processes are normally distributed and it has long been known that this is not the case. This fundamental assumption leads to a number of shortcomings associated with using the EMH to analyse financial data which includes failure to ...

  20. Dopamine and Reward: The Anhedonia Hypothesis 30 years on

    OpenAIRE

    Wise, Roy A.

    2008-01-01

    The anhedonia hypothesis – that brain dopamine plays a critical role in the subjective pleasure associated with positive rewards – was intended to draw the attention of psychiatrists to the growing evidence that dopamine plays a critical role in the objective reinforcement and incentive motivation associated with food and water, brain stimulation reward, and psychomotor stimulant and opiate reward. The hypothesis called to attention the apparent paradox that neuroleptics, drugs used to treat ...

  1. Vigilant and Invincible

    National Research Council Canada - National Science Library

    Moeller, Stephen

    1995-01-01

    .... From the first deployment of World War II-vintage antiaircraft guns in 1950 to the inactivation of the last NIKE HERCULES missile system in 1974, ARADCOM provided a deterrent to the Soviet strategic...

  2. Contribution of Vigilance

    Indian Academy of Sciences (India)

    2017-11-17

    Nov 17, 2017 ... positions in government in the infrastructure, energy, transport ... service. He has served as Principal Secretary, Energy. Department; Chairman, BESCOM; MD, ... ALL ARE WELCOME RSVP: 2266 1222. E. W. RSVP: 2266 1222.

  3. Langevin- Science and vigilance

    International Nuclear Information System (INIS)

    Bensaude-Vincent, B.

    1987-01-01

    Paul Langevin personifies the figure of popular scientist, buried in the Pantheon, because he was in all great fights: to diffuse knowledge, for improvement and democratization of teaching, for justice and peace. Great theoretician of physics, comparable to Einstein whom he rejoined the approach, he was a fertile discoverer, author, in particular, of a proceeding to detect submarines. He fought politically, regardless of his career, in the ranges of pacifists and opponents of fascism. This book reveals, in his warm diversity, a badly known personality, in spite of the legend in his lifetime. (N.C.)

  4. Testing the null hypothesis: the forgotten legacy of Karl Popper?

    Science.gov (United States)

    Wilkinson, Mick

    2013-01-01

    Testing of the null hypothesis is a fundamental aspect of the scientific method and has its basis in the falsification theory of Karl Popper. Null hypothesis testing makes use of deductive reasoning to ensure that the truth of conclusions is irrefutable. In contrast, attempting to demonstrate the new facts on the basis of testing the experimental or research hypothesis makes use of inductive reasoning and is prone to the problem of the Uniformity of Nature assumption described by David Hume in the eighteenth century. Despite this issue and the well documented solution provided by Popper's falsification theory, the majority of publications are still written such that they suggest the research hypothesis is being tested. This is contrary to accepted scientific convention and possibly highlights a poor understanding of the application of conventional significance-based data analysis approaches. Our work should remain driven by conjecture and attempted falsification such that it is always the null hypothesis that is tested. The write up of our studies should make it clear that we are indeed testing the null hypothesis and conforming to the established and accepted philosophical conventions of the scientific method.

  5. Validity and sensitivity of a brief psychomotor vigilance test (PVT-B) to total and partial sleep deprivation

    Science.gov (United States)

    Basner, Mathias; Mollicone, Daniel; Dinges, David F.

    2011-12-01

    The Psychomotor Vigilance Test (PVT) objectively assesses fatigue-related changes in alertness associated with sleep loss, extended wakefulness, circadian misalignment, and time on task. The standard 10-min PVT is often considered impractical in applied contexts. To address this limitation, we developed a modified brief 3-min version of the PVT (PVT-B). The PVT-B was validated in controlled laboratory studies with 74 healthy subjects (34 female, aged 22-45 years) that participated either in a total sleep deprivation (TSD) study involving 33 h awake ( N=31 subjects) or in a partial sleep deprivation (PSD) protocol involving 5 consecutive nights of 4 h time in bed ( N=43 subjects). PVT and PVT-B were performed regularly during wakefulness. Effect sizes of 5 key PVT outcomes were larger for TSD than PSD and larger for PVT than for PVT-B for all outcomes. Effect size was largest for response speed (reciprocal response time) for both the PVT-B and the PVT in both TSD and PSD. According to Cohen's criteria, effect sizes for the PVT-B were still large (TSD) or medium to large (PSD, except for fastest 10% RT). Compared to the 70% decrease in test duration the 22.7% (range 6.9-67.8%) average decrease in effect size was deemed an acceptable trade-off between duration and sensitivity. Overall, PVT-B performance had faster response times, more false starts and fewer lapses than PVT performance (all psleep loss between PVT-B and PVT for all outcome variables (all P>0.15) but the fastest 10% response times during PSD ( P<0.001), and effect sizes increased from 1.38 to 1.49 (TSD) and 0.65 to 0.76 (PSD), respectively. In conclusion, PVT-B tracked standard 10-min PVT performance throughout both TSD and PSD, and yielded medium to large effect sizes. PVT-B may be a useful tool for assessing behavioral alertness in settings where the duration of the 10-min PVT is considered impractical, although further validation in applied settings is needed.

  6. Mecanismos de vigilância e dispositivos de controle: o caso de uma indústria familiar de confecções de Minas Gerais

    Directory of Open Access Journals (Sweden)

    Almiralva Ferraz Gomes

    2008-12-01

    Full Text Available As transformações políticas, sociais e econômicas, cada vez mais aceleradas, mudamo ambiente de negócios do mundo inteiro. Nesse cenário, empresas de diferentesramos, nacionalidades e tamanhos enfrentam-se com o objetivo de ganharmais mercado ou simplesmente de garantir um espaço no mercado. Esse caráteratual de constantes transformações ambientais impõe às organizações, até mesmoàs familiares, uma nova dinâmica. Visando à sua adequação para essa novacondição e ao alcance de competitividade em produtos, serviços e processos, aempresa moderna utiliza-se, muitas vezes, de mecanismos de controle e vigilância.Assim, tendo em vista a importância sociopolítica e econômica da organizaçãofamiliar, o presente trabalho buscou conhecer as interpretações dos váriosagentes sociais a respeito do controle e da vigilância no cotidiano laboral. Apoiadoem uma abordagem qualitativa, estudou-se o caso de uma indústria de confecçõesde caráter familiar localizada no sul de Minas Gerais. Evidenciou-se, nocaso analisado, que o controle e a vigilância podem ser interpretados de formadiferenciada pelos diversos atores sociais e que, a depender da posição hierárquicado indivíduo, sua percepção será distinta.

  7. Análise de situação dos recursos humanos da vigilância sanitária em Salvador - BA, Brasil

    Directory of Open Access Journals (Sweden)

    Cristian Oliveira Benevides Sanches Leal

    Full Text Available Realizou-se uma análise situacional dos recursos humanos da Vigilância Sanitária de Salvador (VISA, a partir da identificação, pelos atores envolvidos, dos principais problemas e seus determinantes relacionados a categorias predefinidas. Trata-se de estudo de caso, descritivo e exploratório com estratégia metodológica baseada no Planejamento Estratégico Situacional. Foram fontes de evidências entrevistas individuais e com grupos focais entre gestores e técnicos da vigilância sanitária. Os resultados indicaram: insuficiência na quantidade, multiprofissionalidade e distribuição dos profissionais; insuficiente capacitação; desmotivação dos profissionais; insuficiente gratificação; não institucionalização do Plano de Cargos, Carreiras e Salários; baixa utilização do potencial dos técnicos e indefinição de requisitos éticos para exercer funções de fiscalização sanitária. Sugere-se melhor estruturação do serviço de Visa, o estabelecimento de uma política de recursos humanos que contemple as especificidades do campo e que considere a necessidade da consolidação do Sistema Nacional de Vigilância Sanitária, bem como investimentos na gestão de recursos humanos.

  8. Análise de situação dos recursos humanos da vigilância sanitária em Salvador - BA, Brasil

    Directory of Open Access Journals (Sweden)

    Cristian Oliveira Benevides Sanches Leal

    2009-09-01

    Full Text Available Realizou-se uma análise situacional dos recursos humanos da Vigilância Sanitária de Salvador (VISA, a partir da identificação, pelos atores envolvidos, dos principais problemas e seus determinantes relacionados a categorias predefinidas. Trata-se de estudo de caso, descritivo e exploratório com estratégia metodológica baseada no Planejamento Estratégico Situacional. Foram fontes de evidências entrevistas individuais e com grupos focais entre gestores e técnicos da vigilância sanitária. Os resultados indicaram: insuficiência na quantidade, multiprofissionalidade e distribuição dos profissionais; insuficiente capacitação; desmotivação dos profissionais; insuficiente gratificação; não institucionalização do Plano de Cargos, Carreiras e Salários; baixa utilização do potencial dos técnicos e indefinição de requisitos éticos para exercer funções de fiscalização sanitária. Sugere-se melhor estruturação do serviço de Visa, o estabelecimento de uma política de recursos humanos que contemple as especificidades do campo e que considere a necessidade da consolidação do Sistema Nacional de Vigilância Sanitária, bem como investimentos na gestão de recursos humanos.

  9. Visual processing of one's own body over the course of time: Evidence for the vigilance-avoidance theory in adolescents with anorexia nervosa?

    Science.gov (United States)

    Bauer, Anika; Schneider, Silvia; Waldorf, Manuel; Cordes, Martin; Huber, Thomas J; Braks, Karsten; Vocks, Silja

    2017-10-01

    The vigilance-avoidance theory postulates a specific threat-related pattern of attention deployment, characterized by initial orientation towards fear-evoking stimuli and subsequent directing of attention away from them. The current eye-tracking study was the first to examine the applicability of the theory for patients with eating disorders, who perceive their own body as a highly aversive, threat-evoking stimulus. N = 56 female adolescents with anorexia nervosa (AN) and n = 43 healthy controls (HC) aged 13-18 viewed own-body pictures while their eye movements were recorded. Relative fixation times on self-defined unattractive body areas were compared between the groups by sequencing the overall presentation time of 6,000 ms into six intervals à 1,000 ms. Participants with AN showed a significantly stronger attentional bias for unattractive body areas than HC within the time intervals 1, 2, and 3. However, for intervals 4, 5, and 6, no significant group differences occurred. Within the AN group, the bias for unattractive body areas was significantly stronger in interval 1 compared to intervals 4, 5, and 6; whereas within the HC group, a stable pattern of attention deployment emerged. In AN, early attention deployment was positively correlated with the negative affect reported after photo presentation. The early vigilance in AN and the subsequent decrease in attention to unattractive body parts is in line with our assumptions. However, no indication of attentional avoidance was found. The current findings partially support the vigilance-avoidance theory for the exposure to one's own body in adolescents with AN. © 2017 Wiley Periodicals, Inc.

  10. Auditory Vigilance and Working Memory in Youth at Familial Risk for Schizophrenia or Affective Psychosis in the Harvard Adolescent Family High Risk Study.

    Science.gov (United States)

    Seidman, Larry J; Pousada-Casal, Andrea; Scala, Silvia; Meyer, Eric C; Stone, William S; Thermenos, Heidi W; Molokotos, Elena; Agnew-Blais, Jessica; Tsuang, Ming T; Faraone, Stephen V

    2016-11-01

    The degree of overlap between schizophrenia (SCZ) and affective psychosis (AFF) has been a recurring question since Kraepelin's subdivision of the major psychoses. Studying nonpsychotic relatives allows a comparison of disorder-associated phenotypes, without potential confounds that can obscure distinctive features of the disorder. Because attention and working memory have been proposed as potential endophenotypes for SCZ and AFF, we compared these cognitive features in individuals at familial high-risk (FHR) for the disorders. Young, unmedicated, first-degree relatives (ages, 13-25 years) at FHR-SCZ (n=41) and FHR-AFF (n=24) and community controls (CCs, n=54) were tested using attention and working memory versions of the Auditory Continuous Performance Test. To determine if schizotypal traits or current psychopathology accounted for cognitive deficits, we evaluated psychosis proneness using three Chapman Scales, Revised Physical Anhedonia, Perceptual Aberration, and Magical Ideation, and assessed psychopathology using the Hopkins Symptom Checklist -90 Revised. Compared to controls, the FHR-AFF sample was significantly impaired in auditory vigilance, while the FHR-SCZ sample was significantly worse in working memory. Both FHR groups showed significantly higher levels of physical anhedonia and some psychopathological dimensions than controls. Adjusting for physical anhedonia, phobic anxiety, depression, psychoticism, and obsessive-compulsive symptoms eliminated the FHR-AFF vigilance effects but not the working memory deficits in FHR-SCZ. The working memory deficit in FHR-SZ was the more robust of the cognitive impairments after accounting for psychopathological confounds and is supported as an endophenotype. Examination of larger samples of people at familial risk for different psychoses remains necessary to confirm these findings and to clarify the role of vigilance in FHR-AFF. (JINS, 2016, 22, 1026-1037).

  11. A vigilant, hypoxia-regulated heme oxygenase-1 gene vector in the heart limits cardiac injury after ischemia-reperfusion in vivo.

    Science.gov (United States)

    Tang, Yao Liang; Qian, Keping; Zhang, Y Clare; Shen, Leping; Phillips, M Ian

    2005-12-01

    The effect of a cardiac specific, hypoxia-regulated, human heme oxygenase-1 (hHO-1) vector to provide cardioprotection from ischemia-reperfusion injury was assessed. When myocardial ischemia and reperfusion is asymptomatic, the damaging effects are cumulative and patients miss timely treatment. A gene therapy approach that expresses therapeutic genes only when ischemia is experienced is a desirable strategy. We have developed a cardiac-specific, hypoxia-regulated gene therapy "vigilant vector'' system that amplifies cardioprotective gene expression. Vigilant hHO-1 plasmids, LacZ plasmids, or saline (n = 40 per group) were injected into mouse heart 2 days in advance of ischemia-reperfusion injury. Animals were exposed to 60 minutes of ischemia followed by 24 hours of reperfusion. For that term (24 hours) effects, the protein levels of HO-1, inflammatory responses, apoptosis, and infarct size were determined. For long-term (3 week) effects, the left ventricular remodeling and recovery of cardiac function were assessed. Ischemia-reperfusion resulted in a timely overexpression of HO-1 protein. Infarct size at 24 hours after ischemia-reperfusion was significantly reduced in the HO-1-treated animals compared with the LacZ-treated group or saline-treated group (P < .001). The reduction of infarct size was accompanied by a decrease in lipid peroxidant activity, inflammatory cell infiltration, and proapoptotic protein level in ischemia-reperfusion-injured myocardium. The long-term study demonstrated that timely, hypoxia-induced HO-1 overexpression is beneficial in conserving cardiac function and attenuating left ventricle remodelling. The vigilant HO-1 vector provides a protective therapy in the heart for reducing cellular damage during ischemia-reperfusion injury and preserving heart function.

  12. Carbohydrate administration during a day of sustained aerobic activity improves vigilance, as assessed by a novel ambulatory monitoring device, and mood.

    Science.gov (United States)

    Lieberman, Harris R; Falco, Christina M; Slade, Steven S

    2002-07-01

    The brain requires a continuous supply of glucose to function adequately. During aerobic exercise, peripheral glucose requirements increase and carbohydrate supplementation improves physical performance. The brain's utilization of glucose also increases during aerobic exercise. However, the effects of energy supplementation on cognitive function during sustained aerobic exercise are not well characterized. The effects of energy supplementation, as liquid carbohydrate, on cognitive function during sustained aerobic activity were examined. A double-blind, placebo-controlled, between-subjects design was used. Young, healthy men (n = 143) were randomly assigned to 1 of 3 treatment groups. The groups received either a 6% (by vol) carbohydrate (35.1 kJ/kg), 12% (by vol) carbohydrate (70.2 kJ/kg), or placebo beverage in 6 isovolumic doses, and all groups consumed 2 meals (3200 kJ). Over the 10-h study, the subjects performed physically demanding tasks, including a 19.3-km road march and two 4.8-km runs, interspersed with rest and other activities. Wrist-worn vigilance monitors, which emitted auditory stimuli (20/h) to which the subjects responded as rapidly as possible, and a standardized self-report mood questionnaire were used to assess cognitive function. Vigilance consistently improved with supplemental carbohydrates in a dose-related manner; the 12% carbohydrate group performed the best and the placebo group the worst (P Mood-questionnaire results corroborated the results from the monitors; the subjects who received carbohydrates reported less confusion (P = 0.040) and greater vigor (P = 0.025) than did those who received the placebo. Supplemental carbohydrate beverages enhance vigilance and mood during sustained physical activity and interspersed rest. In addition, ambulatory monitoring devices can continuously assess the effects of nutritional factors on cognition as individuals conduct their daily activities or participate in experiments.

  13. Desenvolvimento da Vigilância Epidemiológica de Fronteira no contexto da Globalização: conceitos e marcos teóricos.

    Directory of Open Access Journals (Sweden)

    Robson BRUNIERA-OLIVEIRA

    2014-12-01

    Full Text Available Objetivo. Apresentar e analisar as ações desenvolvidas para a implementação e desenvolvimento de Vigilância Epidemiológica de Fronteiras, nos Blocos Econômicos Multinacionais, particularmente na América do Sul e Brasil. Metodologia. Foi realizado um estudo de revisão narrativa incluindo artigos científicos, documentos técnicos, diretrizes, normas, manuais, pautas de reuniões ou qualquer outro documento que fosse relacionado ao desenvolvimento e implementação de ações e programas de Vigilância Epidemiológica em Fronteiras. O estudo foi baseado nos sites das instituições/organizações multinacionais e nas bases MedLine, PubMed, Scielo e Scopus. Resultados. Foram identificados a criação de órgãos e ações no intuito de implementar e desenvolver a vigilância epidemiológica de fronteiras para os seguintes blocos: União Europeia (Health Security Committee, European Center for Disease Prevention and Control, Sistema de alerta rápido e resposta, General Rapid Alert System e Rede de Monitoramento Ad Hoc; Tratado Norte-Americano de Livre Comércio (Border Infectious Disease Surveillance, “Projeto de Vigilância e Alerta Rápido de Doenças Infeciosas” ; Mercado Comum do Sul ( Reunião de Ministros da Saúde do Mercosul, Subgrupo de Trabalho 11 Saúde e Subcomissão Controle Sanitário de Portos, Aeroportos, Terminais e Passos Fronteiriços Terrestres; e União de Nações Sul-Americanas. Conclusões. Os programas e politicas desenvolvidos até o momento refletem o reconhecimento da importância do assunto por parte dos Estados Membros da OMS. Uma maior integração, com troca de informações, incluindo fluxos, frameworks, planos de preparação e o fortalecimento de áreas estratégicas como de energia e transporte deve ser incentivada intra e inter blocos.

  14. Psychosocial and biological aspects of dispositional optimism at old age

    NARCIS (Netherlands)

    Rius Ottenheim, Nathaly

    2012-01-01

    The findings presented in this thesis fit the hypothesis that optimism is associated with enhanced mental well-being and longevity, but also that levels of optimism within a certain person are rather stable over time and resistant to change. However, this stability of optimism does not necessarily

  15. Robust real-time pattern matching using bayesian sequential hypothesis testing.

    Science.gov (United States)

    Pele, Ofir; Werman, Michael

    2008-08-01

    This paper describes a method for robust real time pattern matching. We first introduce a family of image distance measures, the "Image Hamming Distance Family". Members of this family are robust to occlusion, small geometrical transforms, light changes and non-rigid deformations. We then present a novel Bayesian framework for sequential hypothesis testing on finite populations. Based on this framework, we design an optimal rejection/acceptance sampling algorithm. This algorithm quickly determines whether two images are similar with respect to a member of the Image Hamming Distance Family. We also present a fast framework that designs a near-optimal sampling algorithm. Extensive experimental results show that the sequential sampling algorithm performance is excellent. Implemented on a Pentium 4 3 GHz processor, detection of a pattern with 2197 pixels, in 640 x 480 pixel frames, where in each frame the pattern rotated and was highly occluded, proceeds at only 0.022 seconds per frame.

  16. Modelo conceitual para projetos de instalações produtivas sujeitas à Vigilância Sanitária / Conceptual model for production facilities projects subject to Sanitary Surveillance

    Directory of Open Access Journals (Sweden)

    Marcelo Battesini

    2014-08-01

    Full Text Available O projeto de instalações produtivas objeto da ação de Vigilância Sanitária é uma atividade complexa e multidisciplinar que deve resultar em arranjos espaciais capazes de otimizar a obtenção de produtos e atender à regulação sanitária. A linguagem utilizada na legisla-ção sanitária dificulta sua compreensão por projetistas, prejudicando o entendimento da relação direta entre o risco sanitário, as instalações e os fluxos por elas condicionados. O objetivo do artigo é propor um Modelo Conceitual para projetos de Instalações Produtivas sujeitas à Vigilância Sanitária (MCIP-VISA. A coleta de dados ocorrida durante o processo de trabalho participativo e multidisciplinar no nível estadual da VISA, no RS, no período de 2000 a 2010, caracterizam a natureza aplicada e a abordagem qualitativa utilizada. Como resultados são apresentados uma sistematização dos requisitos legais para instalações, as diferentes formas de compor os espaços, os fluxos e o sequenciamento de processos, e as implicações práticas da utilização do modelo no projeto e avaliação de instalações. A aplicação do MCIP-VISA em situações reais demonstrou não haver incompatibilidade entre projetar instalações que minimizem os riscos sanitários e simultaneamente otimizem a produção. A demanda legal pela aprovação dos projetos de instalações pela VISA se mos-trou um momento oportuno à reflexão sobre o planejamento de infraestruturas físicas capazes de viabilizar o cumprimento das Boas Práticas de Fabricação. ------------------------------------------------------------------------ The design of production facilities subject to Sanitary Surveillance is a complex and multi-disciplinary activity that should result in spatial arrangements that optimize the products obtainment and meet the sanitary regulation. The language used in health legislation diffi-cult its understanding by designers, hindering the understanding of the direct

  17. Hypothesis tests for the detection of constant speed radiation moving sources

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Sannie, Guillaume; Gameiro, Jordan; Normand, Stephane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 99 Gif-sur-Yvette, (France); Mechin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 4050 Caen, (France)

    2015-07-01

    Radiation Portal Monitors are deployed in linear network to detect radiological material in motion. As a complement to single and multichannel detection algorithms, inefficient under too low signal to noise ratios, temporal correlation algorithms have been introduced. Test hypothesis methods based on empirically estimated mean and variance of the signals delivered by the different channels have shown significant gain in terms of a tradeoff between detection sensitivity and false alarm probability. This paper discloses the concept of a new hypothesis test for temporal correlation detection methods, taking advantage of the Poisson nature of the registered counting signals, and establishes a benchmark between this test and its empirical counterpart. The simulation study validates that in the four relevant configurations of a pedestrian source carrier under respectively high and low count rate radioactive background, and a vehicle source carrier under the same respectively high and low count rate radioactive background, the newly introduced hypothesis test ensures a significantly improved compromise between sensitivity and false alarm, while guaranteeing the stability of its optimization parameter regardless of signal to noise ratio variations between 2 to 0.8. (authors)

  18. A large scale test of the gaming-enhancement hypothesis

    Directory of Open Access Journals (Sweden)

    Andrew K. Przybylski

    2016-11-01

    Full Text Available A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis, has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people’s gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work.

  19. A large scale test of the gaming-enhancement hypothesis.

    Science.gov (United States)

    Przybylski, Andrew K; Wang, John C

    2016-01-01

    A growing research literature suggests that regular electronic game play and game-based training programs may confer practically significant benefits to cognitive functioning. Most evidence supporting this idea, the gaming-enhancement hypothesis , has been collected in small-scale studies of university students and older adults. This research investigated the hypothesis in a general way with a large sample of 1,847 school-aged children. Our aim was to examine the relations between young people's gaming experiences and an objective test of reasoning performance. Using a Bayesian hypothesis testing approach, evidence for the gaming-enhancement and null hypotheses were compared. Results provided no substantive evidence supporting the idea that having preference for or regularly playing commercially available games was positively associated with reasoning ability. Evidence ranged from equivocal to very strong in support for the null hypothesis over what was predicted. The discussion focuses on the value of Bayesian hypothesis testing for investigating electronic gaming effects, the importance of open science practices, and pre-registered designs to improve the quality of future work.

  20. Investigating the environmental Kuznets curve hypothesis in Vietnam

    International Nuclear Information System (INIS)

    Al-Mulali, Usama; Saboori, Behnaz; Ozturk, Ilhan

    2015-01-01

    This study investigates the existence of the environmental Kuznets curve (EKC) hypothesis in Vietnam during the period 1981–2011. To realize the goals of this study, a pollution model was established applying the Autoregressive Distributed Lag (ARDL) methodology. The results revealed that the pollution haven hypothesis does exist in Vietnam because capital increases pollution. In addition, imports also increase pollution which indicates that most of Vietnam's imported products are energy intensive and highly polluted. However, exports have no effect on pollution which indicates that the level of exports is not significant enough to affect pollution. Moreover, fossil fuel energy consumption increases pollution while renewable energy consumption has no significant effect in reducing pollution. Furthermore, labor force reduces pollution since most of Vietnam's labor force is in the agricultural and services sectors which are less energy intensive than the industrial sector. Based on the obtained results, the EKC hypothesis does not exist because the relationship between GDP and pollution is positive in both the short and long run. - Highlights: • The environmental Kuznets curve (EKC) hypothesis in Vietnam is investigated. • The Autoregressive Distributed Lag (ARDL) methodology was utilized. • The EKC hypothesis does not exist

  1. Social learning and evolution: the cultural intelligence hypothesis

    Science.gov (United States)

    van Schaik, Carel P.; Burkart, Judith M.

    2011-01-01

    If social learning is more efficient than independent individual exploration, animals should learn vital cultural skills exclusively, and routine skills faster, through social learning, provided they actually use social learning preferentially. Animals with opportunities for social learning indeed do so. Moreover, more frequent opportunities for social learning should boost an individual's repertoire of learned skills. This prediction is confirmed by comparisons among wild great ape populations and by social deprivation and enculturation experiments. These findings shaped the cultural intelligence hypothesis, which complements the traditional benefit hypotheses for the evolution of intelligence by specifying the conditions in which these benefits can be reaped. The evolutionary version of the hypothesis argues that species with frequent opportunities for social learning should more readily respond to selection for a greater number of learned skills. Because improved social learning also improves asocial learning, the hypothesis predicts a positive interspecific correlation between social-learning performance and individual learning ability. Variation among primates supports this prediction. The hypothesis also predicts that more heavily cultural species should be more intelligent. Preliminary tests involving birds and mammals support this prediction too. The cultural intelligence hypothesis can also account for the unusual cognitive abilities of humans, as well as our unique mechanisms of skill transfer. PMID:21357223

  2. Dopamine and reward: the anhedonia hypothesis 30 years on.

    Science.gov (United States)

    Wise, Roy A

    2008-10-01

    The anhedonia hypothesis--that brain dopamine plays a critical role in the subjective pleasure associated with positive rewards--was intended to draw the attention of psychiatrists to the growing evidence that dopamine plays a critical role in the objective reinforcement and incentive motivation associated with food and water, brain stimulation reward, and psychomotor stimulant and opiate reward. The hypothesis called to attention the apparent paradox that neuroleptics, drugs used to treat a condition involving anhedonia (schizophrenia), attenuated in laboratory animals the positive reinforcement that we normally associate with pleasure. The hypothesis held only brief interest for psychiatrists, who pointed out that the animal studies reflected acute actions of neuroleptics whereas the treatment of schizophrenia appears to result from neuroadaptations to chronic neuroleptic administration, and that it is the positive symptoms of schizophrenia that neuroleptics alleviate, rather than the negative symptoms that include anhedonia. Perhaps for these reasons, the hypothesis has had minimal impact in the psychiatric literature. Despite its limited heuristic value for the understanding of schizophrenia, however, the anhedonia hypothesis has had major impact on biological theories of reinforcement, motivation, and addiction. Brain dopamine plays a very important role in reinforcement of response habits, conditioned preferences, and synaptic plasticity in cellular models of learning and memory. The notion that dopamine plays a dominant role in reinforcement is fundamental to the psychomotor stimulant theory of addiction, to most neuroadaptation theories of addiction, and to current theories of conditioned reinforcement and reward prediction. Properly understood, it is also fundamental to recent theories of incentive motivation.

  3. Social learning and evolution: the cultural intelligence hypothesis.

    Science.gov (United States)

    van Schaik, Carel P; Burkart, Judith M

    2011-04-12

    If social learning is more efficient than independent individual exploration, animals should learn vital cultural skills exclusively, and routine skills faster, through social learning, provided they actually use social learning preferentially. Animals with opportunities for social learning indeed do so. Moreover, more frequent opportunities for social learning should boost an individual's repertoire of learned skills. This prediction is confirmed by comparisons among wild great ape populations and by social deprivation and enculturation experiments. These findings shaped the cultural intelligence hypothesis, which complements the traditional benefit hypotheses for the evolution of intelligence by specifying the conditions in which these benefits can be reaped. The evolutionary version of the hypothesis argues that species with frequent opportunities for social learning should more readily respond to selection for a greater number of learned skills. Because improved social learning also improves asocial learning, the hypothesis predicts a positive interspecific correlation between social-learning performance and individual learning ability. Variation among primates supports this prediction. The hypothesis also predicts that more heavily cultural species should be more intelligent. Preliminary tests involving birds and mammals support this prediction too. The cultural intelligence hypothesis can also account for the unusual cognitive abilities of humans, as well as our unique mechanisms of skill transfer.

  4. A comparator-hypothesis account of biased contingency detection.

    Science.gov (United States)

    Vadillo, Miguel A; Barberia, Itxaso

    2018-02-12

    Our ability to detect statistical dependencies between different events in the environment is strongly biased by the number of coincidences between them. Even when there is no true covariation between a cue and an outcome, if the marginal probability of either of them is high, people tend to perceive some degree of statistical contingency between both events. The present paper explores the ability of the Comparator Hypothesis to explain the general pattern of results observed in this literature. Our simulations show that this model can account for the biasing effects of the marginal probabilities of cues and outcomes. Furthermore, the overall fit of the Comparator Hypothesis to a sample of experimental conditions from previous studies is comparable to that of the popular Rescorla-Wagner model. These results should encourage researchers to further explore and put to the test the predictions of the Comparator Hypothesis in the domain of biased contingency detection. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. The large numbers hypothesis and a relativistic theory of gravitation

    International Nuclear Information System (INIS)

    Lau, Y.K.; Prokhovnik, S.J.

    1986-01-01

    A way to reconcile Dirac's large numbers hypothesis and Einstein's theory of gravitation was recently suggested by Lau (1985). It is characterized by the conjecture of a time-dependent cosmological term and gravitational term in Einstein's field equations. Motivated by this conjecture and the large numbers hypothesis, we formulate here a scalar-tensor theory in terms of an action principle. The cosmological term is required to be spatially dependent as well as time dependent in general. The theory developed is appled to a cosmological model compatible with the large numbers hypothesis. The time-dependent form of the cosmological term and the scalar potential are then deduced. A possible explanation of the smallness of the cosmological term is also given and the possible significance of the scalar field is speculated

  6. Universality hypothesis breakdown at one-loop order

    Science.gov (United States)

    Carvalho, P. R. S.

    2018-05-01

    We probe the universality hypothesis by analytically computing the at least two-loop corrections to the critical exponents for q -deformed O (N ) self-interacting λ ϕ4 scalar field theories through six distinct and independent field-theoretic renormalization group methods and ɛ -expansion techniques. We show that the effect of q deformation on the one-loop corrections to the q -deformed critical exponents is null, so the universality hypothesis is broken down at this loop order. Such an effect emerges only at the two-loop and higher levels, and the validity of the universality hypothesis is restored. The q -deformed critical exponents obtained through the six methods are the same and, furthermore, reduce to their nondeformed values in the appropriated limit.

  7. Unicorns do exist: a tutorial on "proving" the null hypothesis.

    Science.gov (United States)

    Streiner, David L

    2003-12-01

    Introductory statistics classes teach us that we can never prove the null hypothesis; all we can do is reject or fail to reject it. However, there are times when it is necessary to try to prove the nonexistence of a difference between groups. This most often happens within the context of comparing a new treatment against an established one and showing that the new intervention is not inferior to the standard. This article first outlines the logic of "noninferiority" testing by differentiating between the null hypothesis (that which we are trying to nullify) and the "nill" hypothesis (there is no difference), reversing the role of the null and alternate hypotheses, and defining an interval within which groups are said to be equivalent. We then work through an example and show how to calculate sample sizes for noninferiority studies.

  8. Almost-Quantum Correlations Violate the No-Restriction Hypothesis.

    Science.gov (United States)

    Sainz, Ana Belén; Guryanova, Yelena; Acín, Antonio; Navascués, Miguel

    2018-05-18

    To identify which principles characterize quantum correlations, it is essential to understand in which sense this set of correlations differs from that of almost-quantum correlations. We solve this problem by invoking the so-called no-restriction hypothesis, an explicit and natural axiom in many reconstructions of quantum theory stating that the set of possible measurements is the dual of the set of states. We prove that, contrary to quantum correlations, no generalized probabilistic theory satisfying the no-restriction hypothesis is able to reproduce the set of almost-quantum correlations. Therefore, any theory whose correlations are exactly, or very close to, the almost-quantum correlations necessarily requires a rule limiting the possible measurements. Our results suggest that the no-restriction hypothesis may play a fundamental role in singling out the set of quantum correlations among other nonsignaling ones.

  9. Motor synergies and the equilibrium-point hypothesis.

    Science.gov (United States)

    Latash, Mark L

    2010-07-01

    The article offers a way to unite three recent developments in the field of motor control and coordination: (1) The notion of synergies is introduced based on the principle of motor abundance; (2) The uncontrolled manifold hypothesis is described as offering a computational framework to identify and quantify synergies; and (3) The equilibrium-point hypothesis is described for a single muscle, single joint, and multijoint systems. Merging these concepts into a single coherent scheme requires focusing on control variables rather than performance variables. The principle of minimal final action is formulated as the guiding principle within the referent configuration hypothesis. Motor actions are associated with setting two types of variables by a controller, those that ultimately define average performance patterns and those that define associated synergies. Predictions of the suggested scheme are reviewed, such as the phenomenon of anticipatory synergy adjustments, quick actions without changes in synergies, atypical synergies, and changes in synergies with practice. A few models are briefly reviewed.

  10. On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

    Science.gov (United States)

    LeBoeuf, Richard L.; Mehta, Rabindra D.

    1995-01-01

    In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

  11. Nonlinear optimization

    CERN Document Server

    Ruszczynski, Andrzej

    2011-01-01

    Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates the theory and the methods of nonlinear optimization in a unified, clear, and mathematically rigorous fashion, with detailed and easy-to-follow proofs illustrated by numerous examples and figures. The book covers convex analysis, the theory of optimality conditions, duality theory, and numerical methods for solving unconstrained and constrained optimization problems. It addresses not only classical material but also modern top...

  12. The frequentist implications of optional stopping on Bayesian hypothesis tests.

    Science.gov (United States)

    Sanborn, Adam N; Hills, Thomas T

    2014-04-01

    Null hypothesis significance testing (NHST) is the most commonly used statistical methodology in psychology. The probability of achieving a value as extreme or more extreme than the statistic obtained from the data is evaluated, and if it is low enough, the null hypothesis is rejected. However, because common experimental practice often clashes with the assumptions underlying NHST, these calculated probabilities are often incorrect. Most commonly, experimenters use tests that assume that sample sizes are fixed in advance of data collection but then use the data to determine when to stop; in the limit, experimenters can use data monitoring to guarantee that the null hypothesis will be rejected. Bayesian hypothesis testing (BHT) provides a solution to these ills because the stopping rule used is irrelevant to the calculation of a Bayes factor. In addition, there are strong mathematical guarantees on the frequentist properties of BHT that are comforting for researchers concerned that stopping rules could influence the Bayes factors produced. Here, we show that these guaranteed bounds have limited scope and often do not apply in psychological research. Specifically, we quantitatively demonstrate the impact of optional stopping on the resulting Bayes factors in two common situations: (1) when the truth is a combination of the hypotheses, such as in a heterogeneous population, and (2) when a hypothesis is composite-taking multiple parameter values-such as the alternative hypothesis in a t-test. We found that, for these situations, while the Bayesian interpretation remains correct regardless of the stopping rule used, the choice of stopping rule can, in some situations, greatly increase the chance of experimenters finding evidence in the direction they desire. We suggest ways to control these frequentist implications of stopping rules on BHT.

  13. Copa do Mundo FIFA Brasil 2014: vigilância ativa e perfil dos atendimentos de saúde na cidade-sede de Fortaleza, Ceará

    Directory of Open Access Journals (Sweden)

    Márcio Henrique de Oliveira Garcia

    Full Text Available Resumo OBJETIVO: descrever a estratégia de vigilância ativa em tempo real e o perfil dos atendimentos de saúde realizados no período da 20ª Copa do Mundo da FIFA Brasil 2014 (CMFB, na cidade-sede de Fortaleza, Ceará, Brasil. MÉTODO: estudo descritivo com dados das fichas de atendimento relacionados à Copa, entre 8/6 e 13/7/2014, nas unidades de saúde pré-selecionadas. RESULTADOS: foram 2.570 atendimentos relacionados à CMFB, 56% de indivíduos do sexo masculino, 35% de 20 a 29 anos de idade, 68% foram atendimentos clínicos, 64% de torcedores/espectadores; 94% dos atendidos foram liberados, 3% removidos, 3% internados e 0,2% idos a óbito; os postos médicos avançados responderam por 79% dos atendimentos, principalmente nos dias de jogos. CONCLUSÃO: não foram identificados eventos de Saúde Pública de grande relevância; a estratégia de vigilância ativa possibilitou monitorar a situação de saúde dos envolvidos no evento.

  14. Pode a Vigilância em Saúde ser emancipatória? Um pensamento alternativo de alternativas em tempos de crise

    Directory of Open Access Journals (Sweden)

    Marcelo Firpo de Souza Porto

    Full Text Available Resumo Este artigo, na forma de ensaio, é um convite à reflexão sobre o caráter emancipatório da vigilância em/da saúde, um debate interrompido na década de 1990. Em tempos de grave crise política e institucional no Brasil e no ano da 1ª Conferência Nacional de Vigilância em Saúde (1ª CNVS, é estratégico renovar as discussões teóricas e epistemológicas críticas que fundamentaram a trajetória da medicina social latino-americana e da saúde coletiva nos últimos 40 anos. Para isso, baseamo-nos nos pensamentos críticos da modernidade que articulam o capitalismo, o colonialismo (ou a colonialidade e o patriarcalismo como os três pilares da dominação, segundo o sociólogo português Boaventura de Sousa Santos. Em um contexto de crise civilizatória, repensar a emancipação significa atualizar o significado das lutas sociais em seu relacionamento com o conhecimento e as epistemologias desprezadas pela civilização moderna e ainda presentes no Sul Global, seja nos espaços indígenas e camponeses ou nas periferias urbanas.

  15. Sistema de vigilância alimentar e nutricional: frustrações, desafios e perspectivas Food and nutritional surveillance system: frustrations, challenges and perspectives

    Directory of Open Access Journals (Sweden)

    Bertoldo K. G. de Arruda

    1992-03-01

    Full Text Available O autor refere o valor da vigilância alimentar e nutricional, as frustrações decorrentes da sua implementação, os desafios que se apresentam ao desenvolviemnto do Sisvan, analisando-os em várias dimensões - política, técnica, organizacional, operacional e social - e as perspectivas surgidas com a valorização, ultimamente, dos aspectos nutricionais como referencial obrigatório das políticas sociais e econômicas. Um ponto enfatizado é ser a vigilância uma atividade de natureza eminentemente local, que encontra respaldo nas propostas de descentralização, que se concretizam na municipalização dos serviços de saúde.The author reports the importance of food and nutritional surveillance, the frustations experienced during its implementation, and challenges faced in the development of Sisvan, analysing their varions dimensions - political, technical, organizational, operational and social - as well as recent perspectives generated by the recognition of nutritional aspects as a mandatory reference for social and economic policies. Emphasis is given to surveillance as a basically local activity in nature, supported by decentralization proposals which are materialized in the municipalization of health services.

  16. ArrayVigil: a methodology for statistical comparison of gene signatures using segregated-one-tailed (SOT) Wilcoxon's signed-rank test.

    Science.gov (United States)

    Khan, Haseeb Ahmad

    2005-01-28

    Due to versatile diagnostic and prognostic fidelity molecular signatures or fingerprints are anticipated as the most powerful tools for cancer management in the near future. Notwithstanding the experimental advancements in microarray technology, methods for analyzing either whole arrays or gene signatures have not been firmly established. Recently, an algorithm, ArraySolver has been reported by Khan for two-group comparison of microarray gene expression data using two-tailed Wilcoxon signed-rank test. Most of the molecular signatures are composed of two sets of genes (hybrid signatures) wherein up-regulation of one set and down-regulation of the other set collectively define the purpose of a gene signature. Since the direction of a selected gene's expression (positive or negative) with respect to a particular disease condition is known, application of one-tailed statistics could be a more relevant choice. A novel method, ArrayVigil, is described for comparing hybrid signatures using segregated-one-tailed (SOT) Wilcoxon signed-rank test and the results compared with integrated-two-tailed (ITT) procedures (SPSS and ArraySolver). ArrayVigil resulted in lower P values than those obtained from ITT statistics while comparing real data from four signatures.

  17. Sleep restriction therapy for insomnia is associated with reduced objective total sleep time, increased daytime somnolence, and objectively impaired vigilance: implications for the clinical management of insomnia disorder.

    Science.gov (United States)

    Kyle, Simon D; Miller, Christopher B; Rogers, Zoe; Siriwardena, A Niroshan; Macmahon, Kenneth M; Espie, Colin A

    2014-02-01

    To investigate whether sleep restriction therapy (SRT) is associated with reduced objective total sleep time (TST), increased daytime somnolence, and impaired vigilance. Within-subject, noncontrolled treatment investigation. Sleep research laboratory. Sixteen patients [10 female, mean age = 47.1 (10.8) y] with well-defined psychophysiological insomnia (PI), reporting TST ≤ 6 h. Patients were treated with single-component SRT over a 4-w protocol, sleeping in the laboratory for 2 nights prior to treatment initiation and for 3 nights (SRT night 1, 8, 22) during the acute interventional phase. The psychomotor vigilance task (PVT) was completed at seven defined time points [day 0 (baseline), day 1,7,8,21,22 (acute treatment) and day 84 (3 mo)]. The Epworth Sleepiness Scale (ESS) was completed at baseline, w 1-4, and 3 mo. Subjective sleep outcomes and global insomnia severity significantly improved before and after SRT. There was, however, a robust decrease in PSG-defined TST during acute implementation of SRT, by an average of 91 min on night 1, 78 min on night 8, and 69 min on night 22, relative to baseline (P insomnia.

  18. Grupo PET-Saúde/Vigilância em Saúde do Trabalhador Portuário: vivência compartilhada

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Ferreira Queiróz

    2015-12-01

    Full Text Available Trata-se de um relato de vivência compartilhada do Grupo PET-Saúde/ Vigilância em Saúde do Trabalhador Portuário, da Universidade Federal de São Paulo – Unifesp e o Centro de Referência em Saúde do Trabalhador – CEREST, de Santos, SP. O objetivo é descrever a experiência desse grupo tutorial e sua contribuição para o fortalecimento de ações de vigilância em saúde do trabalhador de Santos. O trabalho portuário é a temática do PET-Saúde por sua importância no cenário nacional e por sofrer transformações que geram fatores de agravos à saúde dos trabalhadores. As ações são desenvolvidas englobando o CEREST, os serviços da rede de saúde de Santos e a comunidade portuária santista. Observa-se que os participantes têm compartilhado conhecimento teórico e prático profissional, contribuindo nas ações dos trabalhadores do CEREST e apontando na direção de aproximação com a rede básica de atenção à saúde.

  19. Thermalization without eigenstate thermalization hypothesis after a quantum quench.

    Science.gov (United States)

    Mori, Takashi; Shiraishi, Naoto

    2017-08-01

    Nonequilibrium dynamics of a nonintegrable system without the eigenstate thermalization hypothesis is studied. It is shown that, in the thermodynamic limit, this model thermalizes after an arbitrary quantum quench at finite temperature, although it does not satisfy the eigenstate thermalization hypothesis. In contrast, when the system size is finite and the temperature is low enough, the system may not thermalize. In this case, the steady state is well described by the generalized Gibbs ensemble constructed by using highly nonlocal conserved quantities. We also show that this model exhibits prethermalization, in which the prethermalized state is characterized by nonthermal energy eigenstates.

  20. Tunguska, 1908: the gas pouch and soil fluidization hypothesis

    Science.gov (United States)

    Nistor, I.

    2012-01-01

    The Siberian taiga explosion of 30 June 1908 remains one of the great mysteries of the 20th century: millions of trees put down over an area of 2200 km2 without trace of a crater or meteorite fragments. Hundred years of failed searches have followed, resulting in as many flawed hypothesis which could not offer satisfactory explanations: meteorite, comet, UFO, etc. In the author's opinion, the cause is that the energy the explorers looked for was simply not there! The author's hypothesis is that a meteoroid encountered a gas pouch in the atmosphere, producing a devastating explosion, its effects being amplified by soil fluidization.

  1. The equilibrium-point hypothesis--past, present and future.

    Science.gov (United States)

    Feldman, Anatol G; Levin, Mindy F

    2009-01-01

    This chapter is a brief account of fundamentals of the equilibrium-point hypothesis or more adequately called the threshold control theory (TCT). It also compares the TCT with other approaches to motor control. The basic notions of the TCT are reviewed with a major focus on solutions to the problems of multi-muscle and multi-degrees of freedom redundancy. The TCT incorporates cognitive aspects by explaining how neurons recognize that internal (neural) and external (environmental) events match each other. These aspects as well as how motor learning occurs are subjects of further development of the TCT hypothesis.

  2. The cosmic censorship hypothesis and the positive energy conjecture

    International Nuclear Information System (INIS)

    Jang, P.S.; Wald, R.W.

    1979-01-01

    The position so far is summarized. Penrose derived an inequality; if a data set was found to violate this then the assumptions deriving the inequality must be false. In this case it could show a counter example to the cosmic censorship hypothesis. The authors have shown elsewhere that a positive energy argument of Geroch can be modified to rule out a violation of Penrose's inequality with any time-symmetric initial data set whose apparent horizon consists of a single component. This increases confidence in the hypothesis and also indicates there may be a close relationship between this conjecture and the positive energy conjecture. (UK)

  3. Eat dirt and avoid atopy: the hygiene hypothesis revisited.

    Science.gov (United States)

    Patki, Anil

    2007-01-01

    The explosive rise in the incidence of atopic diseases in the Western developed countries can be explained on the basis of the so-called "hygiene hypothesis". In short, it attributes the rising incidence of atopic dermatitis to reduced exposure to various childhood infections and bacterial endotoxins. Reduced exposure to dirt in the clean environment results in a skewed development of the immune system which results in an abnormal allergic response to various environmental allergens which are otherwise innocuous. This article reviews the historical aspects, epidemiological and immunological basis of the hygiene hypothesis and implications for Indian conditions.

  4. A inserção da vigilância em saúde ambiental no sistema único de saúde

    Directory of Open Access Journals (Sweden)

    Edenilo Baltazar Barreira Filho

    2012-03-01

    Full Text Available A inserção das atividades de vigilância ambiental no SUS apresenta algumas características que se diferenciam das práticas de vigilância epidemiológica. Isto ocorre principalmente em decorrência de que muitos dados sobre a exposição aos fatores ambientais são obtidos fora do setor saúde e a adoção de ações que busquem controlar e/ou prevenir exigem, na grande maioria dos casos, uma compreensãoe articulação intra e intersetorial, pois o setor saúde não é capaz de, sozinho, dar respostas as questões de saúde ambiental.Nos últimos anos vem consolidando-se cada vez mais o campo da saúdeambiental, que compreende a área da saúde pública, afeita ao conhecimento científico, à formulação de políticas públicas e às correspondentes intervenções (ações relacionadas à interação entre a saúde humana e os fatores do meio ambiente natural e antrópico que a determinam, condicionam e influenciam, com vistas a melhorar a qualidade de vida do ser humano sob o ponto de vista dasustentabilidade(1.Conforme entendimento acordado no I Seminário da Política Nacional de Saúde Ambiental, realizado em outubro de 2005, e consolidado na primeira Conferência Nacional de Saúde Ambiental, realizada em dezembro de 2009, compreende-se como uma área de práticas intersetoriais e transdisciplinares voltadas aos reflexos, na saúde humana, das relações ecogeossociais do homem com o ambiente(1.Nesse sentido, o Ministério da Saúde vem implementando em todo o território nacional um Sistema de Vigilância em Saúde Ambiental (SINVISA, buscando o aprimoramento deste “modelo” de atuação e estabelecendo competências nas três esferas de gestão, com o objetivo de consolidar a prática da Saúde Ambiental dentro do SUS.A Instrução Normativa nº 1, de 7 de março de 2005, cria o SINVISA, estabelece a área de atuação, as competências para as três esferas de Gestão do SUS e define a Vigilância em Saúde Ambiental como sendo

  5. Website Optimization

    CERN Document Server

    King, Andrew

    2008-01-01

    Remember when an optimized website was one that merely didn't take all day to appear? Times have changed. Today, website optimization can spell the difference between enterprise success and failure, and it takes a lot more know-how to achieve success. This book is a comprehensive guide to the tips, techniques, secrets, standards, and methods of website optimization. From increasing site traffic to maximizing leads, from revving up responsiveness to increasing navigability, from prospect retention to closing more sales, the world of 21st century website optimization is explored, exemplified a

  6. Células natural killer e vigilância imunológica Natural killer cells and immune surveillance

    Directory of Open Access Journals (Sweden)

    Mariana Jobim

    2008-08-01

    Full Text Available OBJETIVOS: Analisar a importância das células natural killer, de seus receptores killer immunoglobulin-like receptors e correspondentes genes (KIR na vigilância imunológica do organismo contra agentes infecciosos, transplantes de células-tronco hematopoiéticas, assim como sua participação na auto-imunidade. As características e o polimorfismo dos genes e receptores KIR na população brasileira serão descritos. FONTES DOS DADOS: Livros, artigos de revisão e artigos científicos recentes são citados e listados na bibliografia. A experiência pessoal é também apresentada. SÍNTESE DOS DADOS: Identificamos o perfil de genes e haplótipos KIR na população caucasóide brasileira, sendo de importância esse conhecimento para a análise da relação desse sistema com doenças. Examinamos 116 indivíduos doadores voluntários de medula óssea, identificando-se 32 genótipos e a presença de 51 e 49% de haplótipos A e B, respectivamente. Foi realizado estudo comparativo entre os nossos genótipos e os de outras populações. CONCLUSÕES: A imunidade inata é uma barreira antiinfecciosa de importância em pediatria. Ela atua de maneira independente da imunidade celular e humoral, sendo mais rápida que as demais fontes de proteção do organismo. Ao mesmo tempo, ela estimula os linfócitos T CD8 a agirem e amplificarem a rede de proteção imunológica. Entretanto, como na maioria das vezes em que a imunidade atua, ela também pode ser prejudicial, agredindo o organismo por mecanismos auto-imunes ou mesmo, na sua ausência, oferecer espaço aos agentes infecciosos para agirem de forma impune.OBJECTIVES: To analyze the importance of natural killer cells, their killer immunoglobulin-like receptors (KIR and genes in autoimmunity and in the immune surveillance against infectious agents and stem cells transplantation. The characteristics and polymorphisms of the KIR genes and receptors in the Brazilian population is described. SOURCES

  7. Integração laboratórios-vigilância sanitária: uma revisão | Integration laboratories-sanitary surveillance: a review

    Directory of Open Access Journals (Sweden)

    Rosane Gomes Alves Lopes

    2017-05-01

    Full Text Available Identificar literatura nacional e internacional sobre laboratório e vigilância sanitária para refletir sobre a integração desses serviços no Sistema Nacional de Vigilância Sanitária foi o objetivo da revisão integrativa com busca sistemática em três repositórios: Banco de Teses e Dissertações; Scientific Electronic Library Online – Brasil e Pubmed Central. A seleção seguiu critérios pré-definidos e a análise considerou: tipo de produção acadêmica (mestrado, doutorado ou artigo científico, ano e instituição de origem, tema focalizado. Predominaram trabalhos oriundos do mestrado (64,7% e, como instituição, a Fundação Oswaldo Cruz (36,5%, sendo 90,0% no Instituto Nacional de Controle da Qualidade em Saúde. O controle da qualidade de produtos é área expressiva das publicações (71,0%, incluindo-se nela alimentos, medicamentos e vacinas. Estudos relacionados a políticas públicas e vigilância sanitária tematizaram: medicamentos genéricos; estudos de equivalência farmacêutica; alimentação e nutrição; e integração da Agência Nacional de Vigilância Sanitária com outros atores na inovação de vacinas e na Rede Brasileira de Laboratórios Analíticos em Saúde. A integração se expressou mediante as atividades cooperativas entre laboratórios e serviços, restando aprimorá-la, tendo-se em vista que, no Brasil, os laboratórios e os serviços de vigilância são diferenciados e vinculam-se a entes governamentais distintos. ============================================= This integrative review with systematic search aimed to identify national and international literature on laboratory and sanitary surveillance to reflect on the integration of these services in the National System of Sanitary Surveillance Three repositories were used: Banco de Teses e Dissertações; Scientific Electronic Library Online - Brazil and Pubmed Central. The selection followed pre-defined criteria and the analysis considered

  8. Environmental vigilance programmes of desalination plants. Development of an evaluations method of its application; Los Programas de Vigilancia Ambiental de las Instalaciones Desalinizadoras de Agua Marina. Desarrollo de un metodo de valoracion de su aplicacion

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Arriaga, S.; Garcia Sanchez-Colomer, M.

    2008-07-01

    This article aims to develop a working methodology to assess the application of the measures designed to avoid, reduce and, if possible, remedy significant adverse effects, included in the Environmental Vigilance Programmes. the study is based on a practical case study of the building project, currently under development, of a desalination plant located in the Spanish Mediterranean coast. A collection of measures was selected to be fulfilled in any building project of a desalination plant, and thus the requirements derivates from them. Their analysis will allow to establish the level of fulfillment (regarding to the measures taken from the Environmental Vigilance Programme or the Declaration of Environmental Impact) and the evaluation (regarding to the measures taken from specialized bibliography) of the indicators implementation. This monitoring provides the supervisor of environmental issues with a valid tool to negotiate with the developer certain modifications, with the objective or improving the effectiveness of the measures described in the Environmental Vigilance Programme. (Author) 5 refs.

  9. development of optimized s hollow block with block with ment

    African Journals Online (AJOL)

    eobe

    optimize the design computation process the design ... acy is checked using the control factors. Finally a ... utation process which takes the desired property of the mix, and generat of the mix ...... We recall our statistical hypothesis as follows: 1.

  10. New Hypothesis and Theory about Functions of Sleep and Dreams

    Directory of Open Access Journals (Sweden)

    Nikola N. Ilanković

    2014-03-01

    Conclusion: IEP-P1 could be a new biological marker to distinction of sleep organization in different psychotic states and other states of altered consciousness. The developed statistical models could be the basis for new hypothesis and theories about functions of sleep and dreams.

  11. A test of the reward-value hypothesis.

    Science.gov (United States)

    Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

    2017-03-01

    Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

  12. Revisiting Hudson’s (1992) OO = O2 hypothesis

    DEFF Research Database (Denmark)

    Shibuya, Yoshikata; Jensen, Kim Ebensgaard

    2018-01-01

    In an important paper on the English “double-object”, or ditransitive, construction, Richard Hudson proposes a hypothesis that conflates the ditransitive direct object, or O2, and the monotransitive direct object, or OO, into the same syntactic functional category. While making important departures...

  13. Hypothesis, Prediction, and Conclusion: Using Nature of Science Terminology Correctly

    Science.gov (United States)

    Eastwell, Peter

    2012-01-01

    This paper defines the terms "hypothesis," "prediction," and "conclusion" and shows how to use the terms correctly in scientific investigations in both the school and science education research contexts. The scientific method, or hypothetico-deductive (HD) approach, is described and it is argued that an understanding of the scientific method,…

  14. A sequential hypothesis test based on a generalized Azuma inequality

    NARCIS (Netherlands)

    Reijsbergen, D.P.; Scheinhardt, Willem R.W.; de Boer, Pieter-Tjerk

    We present a new power-one sequential hypothesis test based on a bound for the probability that a bounded zero-mean martingale ever crosses a curve of the form $a(n+k)^b$. The proof of the bound is of independent interest.

  15. Planned Hypothesis Tests Are Not Necessarily Exempt from Multiplicity Adjustment

    Science.gov (United States)

    Frane, Andrew V.

    2015-01-01

    Scientific research often involves testing more than one hypothesis at a time, which can inflate the probability that a Type I error (false discovery) will occur. To prevent this Type I error inflation, adjustments can be made to the testing procedure that compensate for the number of tests. Yet many researchers believe that such adjustments are…

  16. A default Bayesian hypothesis test for correlations and partial correlations

    NARCIS (Netherlands)

    Wetzels, R.; Wagenmakers, E.J.

    2012-01-01

    We propose a default Bayesian hypothesis test for the presence of a correlation or a partial correlation. The test is a direct application of Bayesian techniques for variable selection in regression models. The test is easy to apply and yields practical advantages that the standard frequentist tests

  17. Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael

    This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

  18. Using Employer Hiring Behavior to Test the Educational Signaling Hypothesis

    NARCIS (Netherlands)

    Albrecht, J.W.; van Ours, J.C.

    2001-01-01

    This paper presents a test of the educational signaling hypothesis.If employers use education as a signal in the hiring process, they will rely more on education when less is otherwise known about applicants.We nd that employers are more likely to lower educational standards when an informal, more

  19. Explorations in Statistics: Hypothesis Tests and P Values

    Science.gov (United States)

    Curran-Everett, Douglas

    2009-01-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This second installment of "Explorations in Statistics" delves into test statistics and P values, two concepts fundamental to the test of a scientific null hypothesis. The essence of a test statistic is that it compares what…

  20. THE BARKER HYPOTHESIS: IMPLICATIONS FOR FUTURE DIRECTIONS IN TOXICOLOGY RESEARCH

    Science.gov (United States)

    This review covers the past year’s papers germane to the Barker hypothesis. While much of the literature has centered on maternal and developmental nutrition, new findings have emerged on the ability of toxic exposures during development to impact fetal/developmental programming....

  1. Developmental Dyslexia: The Visual Attention Span Deficit Hypothesis

    Science.gov (United States)

    Bosse, Marie-Line; Tainturier, Marie Josephe; Valdois, Sylviane

    2007-01-01

    The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was…

  2. The "Discouraged-Business-Major" Hypothesis: Policy Implications

    Science.gov (United States)

    Marangos, John

    2012-01-01

    This paper uses a relatively large dataset of the stated academic major preferences of economics majors at a relatively large, not highly selective, public university in the USA to identify the "discouraged-business-majors" (DBMs). The DBM hypothesis addresses the phenomenon where students who are screened out of the business curriculum often…

  3. The Twin Deficits Hypothesis: An Empirical Analysis for Tanzania

    Directory of Open Access Journals (Sweden)

    Manamba Epaphra

    2017-09-01

    Full Text Available This paper examines the relationship between current account and government budget deficits in Tanzania. The paper tests the validity of the twin deficits hypothesis, using annual time series data for the 1966-2015 period. The paper is thought to be significant because the concept of the twin deficit hypothesis is fraught with controversy. Some researches support the hypothesis that there is a positive relationship between current account deficits and fiscal deficits in the economy while others do not. In this paper, the empirical tests fail to reject the twin deficits hypothesis, indicating that rising budget deficits put more strain on the current account deficits in Tanzania. Specifically, the Vector Error Correction Model results support the conventional theory of a positive relationship between fiscal and external balances, with a relatively high speed of adjustment toward the equilibrium position. This evidence is consistent with a small open economy. To address the problem that may result from this kind of relationship, appropriate policy variables for reducing budget deficits such as reduction in non-development expenditure, enhancement of domestic revenue collection and actively fight corruption and tax evasion should be adopted. The government should also target export oriented firms and encourage an import substitution industry by creating favorable business environments.

  4. Etiology of common childhood acute lymphoblastic leukemia: the adrenal hypothesis

    DEFF Research Database (Denmark)

    Schmiegelow, K.; Vestergaard, T.; Nielsen, S.M.

    2008-01-01

    The pattern of infections in the first years of life modulates our immune system, and a low incidence of infections has been linked to an increased risk of common childhood acute lymphoblastic leukemia (ALL). We here present a new interpretation of these observations--the adrenal hypothesis...

  5. Cross-system log file analysis for hypothesis testing

    NARCIS (Netherlands)

    Glahn, Christian; Specht, Marcus; Schoonenboom, Judith; Sligte, Henk; Moghnieh, Ayman; Hernández-Leo, Davinia; Stefanov, Krassen; Lemmers, Ruud; Koper, Rob

    2008-01-01

    Glahn, C., Specht, M., Schoonenboom, J., Sligte, H., Moghnieh, A., Hernández-Leo, D. Stefanov, K., Lemmers, R., & Koper, R. (2008). Cross-system log file analysis for hypothesis testing. In H. Sligte & R. Koper (Eds.), Proceedings of the 4th TENCompetence Open Workshop. Empowering Learners for

  6. The catecholaminergic-cholinergic balance hypothesis of bipolar disorder revisited

    Science.gov (United States)

    van Enkhuizen, Jordy; Janowsky, David S; Olivier, Berend; Minassian, Arpi; Perry, William; Young, Jared W; Geyer, Mark A

    2014-01-01

    Bipolar disorder is a unique illness characterized by fluctuations between mood states of depression and mania. Originally, an adrenergic-cholinergic balance hypothesis was postulated to underlie these different affective states. In this review, we update this hypothesis with recent findings from human and animal studies, suggesting that a catecholaminergic-cholinergic hypothesis may be more relevant. Evidence from neuroimaging studies, neuropharmacological interventions, and genetic associations support the notion that increased cholinergic functioning underlies depression, whereas increased activations of the catecholamines (dopamine and norepinephrine) underlie mania. Elevated functional acetylcholine during depression may affect both muscarinic and nicotinic acetylcholine receptors in a compensatory fashion. Increased functional dopamine and norepinephrine during mania on the other hand may affect receptor expression and functioning of dopamine reuptake transporters. Despite increasing evidence supporting this hypothesis, a relationship between these two neurotransmitter systems that could explain cycling between states of depression and mania is missing. Future studies should focus on the influence of environmental stimuli and genetic susceptibilities that may affect the catecholaminergic-cholinergic balance underlying cycling between the affective states. Overall, observations from recent studies add important data to this revised balance theory of bipolar disorder, renewing interest in this field of research. PMID:25107282

  7. A "Projective" Test of the Golden Section Hypothesis.

    Science.gov (United States)

    Lee, Chris; Adams-Webber, Jack

    1987-01-01

    In a projective test of the golden section hypothesis, 24 high school students rated themselves and 10 comic strip characters on basis of 12 bipolar constructs. Overall proportion of cartoon figures which subjects assigned to positive poles of constructs was very close to golden section. (Author/NB)

  8. The Lehman Sisters Hypothesis: an exploration of literature and bankers

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2012-01-01

    textabstractAbstract This article tests the Lehman Sisters Hypothesis in two complementary, although incomplete ways. It reviews the diverse empirical literature in behavioral, experimental, and neuroeconomics as well as related fields of behavioral research. And it presents the findings from an

  9. The Lehman Sisters Hypothesis: an exploration of literature and bankers

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2012-01-01

    textabstractThis article tests the Lehman Sisters Hypothesis in two complementary, although incomplete ways. It reviews the diverse empirical literature in behavioural, experimental, and neuroeconomics as well as related fields of behavioural research. And it presents the findings from an

  10. A Life-Course Perspective on the "Gateway Hypothesis"

    Science.gov (United States)

    Van Gundy, Karen; Rebellon, Cesar J.

    2010-01-01

    Drawing on stress and life-course perspectives and using panel data from 1,286 south Florida young adults, we assess three critical questions regarding the role of marijuana in the "gateway hypothesis." First, does teen marijuana use independently (causally) affect subsequent use of more dangerous substances? Second, if so, does that…

  11. Shaping Up the Practice of Null Hypothesis Significance Testing.

    Science.gov (United States)

    Wainer, Howard; Robinson, Daniel H.

    2003-01-01

    Discusses criticisms of null hypothesis significance testing (NHST), suggesting that historical use of NHST was reasonable, and current users should read Sir Ronald Fisher's applied work. Notes that modifications to NHST and interpretations of its outcomes might better suit the needs of modern science. Concludes that NHST is most often useful as…

  12. Rational Variability in Children's Causal Inferences: The Sampling Hypothesis

    Science.gov (United States)

    Denison, Stephanie; Bonawitz, Elizabeth; Gopnik, Alison; Griffiths, Thomas L.

    2013-01-01

    We present a proposal--"The Sampling Hypothesis"--suggesting that the variability in young children's responses may be part of a rational strategy for inductive inference. In particular, we argue that young learners may be randomly sampling from the set of possible hypotheses that explain the observed data, producing different hypotheses with…

  13. Assessing Threat Detection Scenarios through Hypothesis Generation and Testing

    Science.gov (United States)

    2015-12-01

    Publications. Field, A. (2005). Discovering statistics using SPSS (2nd ed.). Thousand Oaks, CA: Sage Publications. Fisher, S. D., Gettys, C. F...therefore, subsequent F statistics are reported using the Huynh-Feldt correction (Greenhouse-Geisser Epsilon > .775). Experienced and inexperienced...change in hypothesis using experience and initial confidence as predictors. In the Dog Day scenario, the regression was not statistically

  14. Fecundity of trees and the colonization-competition hypothesis

    Science.gov (United States)

    James S. Clark; Shannon LaDeau; Ines Ibanez

    2004-01-01

    Colonization-competition trade-offs represent a stabilizing mechanism that is thought to maintain diversity of forest trees. If so, then early-successional species should benefit from high capacity to colonize new sites, and late-successional species should be good competitors. Tests of this hypothesis in forests have been precluded by an inability to estimate...

  15. Scalar fields and cosmic censorship hypothesis in general relativity

    International Nuclear Information System (INIS)

    Parnovs'kij, S.L.; Gajdamaka, O.Z.

    2004-01-01

    We discuss an influence of the presence of some nonstandard scalar fields in the vicinity of naked time-like singularity on the type and properties of this singularity. The main goal is to study the validity of the Penrose's Cosmic Censorship hypothesis in the General Relativity

  16. Hypothesis Sampling Systems among Preoperational and Concrete Operational Kindergarten Children

    Science.gov (United States)

    Gholson, Barry; And Others

    1976-01-01

    Preoperational and concrete operational kindergarten children received stimulus differentiation training, either with or without feedback, and then a series of discrimination learning problems in which a blank trial probe was used to detect a child's hypothesis after each feedback trial. Piagetian stage theory requires elaboration to account…

  17. Bayesian Approaches to Imputation, Hypothesis Testing, and Parameter Estimation

    Science.gov (United States)

    Ross, Steven J.; Mackey, Beth

    2015-01-01

    This chapter introduces three applications of Bayesian inference to common and novel issues in second language research. After a review of the critiques of conventional hypothesis testing, our focus centers on ways Bayesian inference can be used for dealing with missing data, for testing theory-driven substantive hypotheses without a default null…

  18. Animal Models for Testing the DOHaD Hypothesis

    Science.gov (United States)

    Since the seminal work in human populations by David Barker and colleagues, several species of animals have been used in the laboratory to test the Developmental Origins of Health and Disease (DOHaD) hypothesis. Rats, mice, guinea pigs, sheep, pigs and non-human primates have bee...

  19. An investigation of the competitiveness hypothesis of the resource curse

    NARCIS (Netherlands)

    L.A. Serino (Leandro)

    2008-01-01

    textabstractIn this paper I investigate the competitiveness explanation of the resource curse: to what extent slow growth in primary producer countries is related to the properties of this pattern of trade specialization. To address this hypothesis that has not been adequately explored in the

  20. Optimality Conditions in Vector Optimization

    CERN Document Server

    Jiménez, Manuel Arana; Lizana, Antonio Rufián

    2011-01-01

    Vector optimization is continuously needed in several science fields, particularly in economy, business, engineering, physics and mathematics. The evolution of these fields depends, in part, on the improvements in vector optimization in mathematical programming. The aim of this Ebook is to present the latest developments in vector optimization. The contributions have been written by some of the most eminent researchers in this field of mathematical programming. The Ebook is considered essential for researchers and students in this field.

  1. Medicinsk Optimering

    DEFF Research Database (Denmark)

    Birkholm, Klavs

    2010-01-01

    En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system......En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system...

  2. Structural optimization

    CERN Document Server

    MacBain, Keith M

    2009-01-01

    Intends to supplement the engineer's box of analysis and design tools making optimization as commonplace as the finite element method in the engineering workplace. This title introduces structural optimization and the methods of nonlinear programming such as Lagrange multipliers, Kuhn-Tucker conditions, and calculus of variations.

  3. Topology Optimization

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt; Damkilde, Lars

    2007-01-01

    . A way to solve the initial design problem namely finding a form can be solved by so-called topology optimization. The idea is to define a design region and an amount of material. The loads and supports are also fidefined, and the algorithm finds the optimal material distribution. The objective function...... dictates the form, and the designer can choose e.g. maximum stiness, maximum allowable stresses or maximum lowest eigenfrequency. The result of the topology optimization is a relatively coarse map of material layout. This design can be transferred to a CAD system and given the necessary geometrically...... refinements, and then remeshed and reanalysed in other to secure that the design requirements are met correctly. The output of standard topology optimization has seldom well-defined, sharp contours leaving the designer with a tedious interpretation, which often results in less optimal structures. In the paper...

  4. Dispositional Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.

    2014-01-01

    Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971

  5. The influence of herd size, conspecific risk, and predation risk on the vigilance of elk (Cervus elaphus) in Yellowstone National Park, and, Interest, learning, and a thematic biology course

    Science.gov (United States)

    Lung, Mark A.

    This dissertation is a composite of biological and educational research. The biological research concerns Rocky Mountain elk (Cervus elaphus ) behavior. The educational research presents ideas and findings on the influence of a thematic general biology course on student interest and perception of learning. The dissertation begins with a Preface that attempts to bring the ideas presented in later chapters together. Chapter One is a review of the literature concerning sociality, social behaviors, and elk biology. It summarizes current research literature as a means of introduction to Chapter Two. Chapter Two presents findings concerning the effects of herd size, predation risk, and the risk of being near conspecifics on two behaviors commonly associated with social animals---vigilance and aggression. Vigilance and aggression were measured in elk in Yellowstone National Park in two regions that varied in their presence of elk predators (wolves---Canis lupus, and grizzly bears---Ursus arctos) and in two seasons (spring and fall) that varied in the risks of being near conspecifics. Overall, male and female elk responded very differently. Male elk adjust their vigilance and aggression in response to changes in conspecific risk, but not to changes in predation risk. Female elk adjust their vigilance in response to changes in predation risk, but not to changes in conspecific risk. Males show no response in vigilance to changes in herd size. Non-reproductive females, however, adjust their levels of vigilance with changes in herd size in high risk regions. Interestingly, in the spring, vigilance decreases with increasing herd size, but in the fall, vigilance increases with increasing herd size. Chapter Three presents findings concerning the influence of a thematic course design on student perceptions of interest and teaming in a non-major's biology course (Bins 100: Concepts of Biology). I compared responses on student evaluations from two sections of Bios 100 taught in a

  6. O Código Filipino, as Normas Camarárias e o comércio: mecanismo de vigilância e regulamentação comercial na Capitania do Rio Grande do Norte

    OpenAIRE

    Dias,Thiago Alves

    2014-01-01

    O artigo propõe apresentar algumas considerações acerca das normas metropolitanas encetadas pelo Código Filipino e sua relação com a atuação do poder local municipal representado pelas Câmaras, notadamente, nos aspectos relacionados à vigilância e à regulamentação das práticas comerciais cotidianas. Partindo dos registros das Câmaras Municipais da Capitania do Rio Grande do Norte, evidenciamos a relação entre poder central e poderes locais com base nas normas, na vigilância e na regulamentaçã...

  7. The Effectiveness of the Comprehension Hypothesis: A Review on the Current Research on Incidental Vocabulary Acquisition

    Science.gov (United States)

    Ponniah, Joseph

    2011-01-01

    The Comprehension Hypothesis (CH) is the most powerful hypothesis in the field of Second Language Acquisition despite the presence of the rivals the skill-building hypothesis, the output hypothesis, and the interaction hypothesis. The competing hypotheses state that consciously learned linguistic knowledge is a necessary step for the development…

  8. Simultaneity modeling analysis of the environmental Kuznets curve hypothesis

    International Nuclear Information System (INIS)

    Ben Youssef, Adel; Hammoudeh, Shawkat; Omri, Anis

    2016-01-01

    The environmental Kuznets curve (EKC) hypothesis has been recognized in the environmental economics literature since the 1990's. Various statistical tests have been used on time series, cross section and panel data related to single and groups of countries to validate this hypothesis. In the literature, the validation has always been conducted by using a single equation. However, since both the environment and income variables are endogenous, the estimation of a single equation model when simultaneity exists produces inconsistent and biased estimates. Therefore, we formulate simultaneous two-equation models to investigate the EKC hypothesis for fifty-six countries, using annual panel data from 1990 to 2012, with the end year is determined by data availability for the panel. To make the panel data analysis more homogeneous, we investigate this issue for a three income-based panels (namely, high-, middle-, and low-income panels) given several explanatory variables. Our results indicate that there exists a bidirectional causality between economic growth and pollution emissions in the overall panels. We also find that the relationship is nonlinear and has an inverted U-shape for all the considered panels. Policy implications are provided. - Highlights: • We have given a new look for the validity of the EKC hypothesis. • We formulate two-simultaneous equation models to validate this hypothesis for fifty-six countries. • We find a bidirectional causality between economic growth and pollution emissions. • We also discover an inverted U-shaped between environmental degradation and economic growth. • This relationship varies at different stages of economic development.

  9. A critique of statistical hypothesis testing in clinical research

    Directory of Open Access Journals (Sweden)

    Somik Raha

    2011-01-01

    Full Text Available Many have documented the difficulty of using the current paradigm of Randomized Controlled Trials (RCTs to test and validate the effectiveness of alternative medical systems such as Ayurveda. This paper critiques the applicability of RCTs for all clinical knowledge-seeking endeavors, of which Ayurveda research is a part. This is done by examining statistical hypothesis testing, the underlying foundation of RCTs, from a practical and philosophical perspective. In the philosophical critique, the two main worldviews of probability are that of the Bayesian and the frequentist. The frequentist worldview is a special case of the Bayesian worldview requiring the unrealistic assumptions of knowing nothing about the universe and believing that all observations are unrelated to each other. Many have claimed that the first belief is necessary for science, and this claim is debunked by comparing variations in learning with different prior beliefs. Moving beyond the Bayesian and frequentist worldviews, the notion of hypothesis testing itself is challenged on the grounds that a hypothesis is an unclear distinction, and assigning a probability on an unclear distinction is an exercise that does not lead to clarity of action. This critique is of the theory itself and not any particular application of statistical hypothesis testing. A decision-making frame is proposed as a way of both addressing this critique and transcending ideological debates on probability. An example of a Bayesian decision-making approach is shown as an alternative to statistical hypothesis testing, utilizing data from a past clinical trial that studied the effect of Aspirin on heart attacks in a sample population of doctors. As a big reason for the prevalence of RCTs in academia is legislation requiring it, the ethics of legislating the use of statistical methods for clinical research is also examined.

  10. Mechanisms of eyewitness suggestibility: tests of the explanatory role hypothesis.

    Science.gov (United States)

    Rindal, Eric J; Chrobak, Quin M; Zaragoza, Maria S; Weihing, Caitlin A

    2017-10-01

    In a recent paper, Chrobak and Zaragoza (Journal of Experimental Psychology: General, 142(3), 827-844, 2013) proposed the explanatory role hypothesis, which posits that the likelihood of developing false memories for post-event suggestions is a function of the explanatory function the suggestion serves. In support of this hypothesis, they provided evidence that participant-witnesses were especially likely to develop false memories for their forced fabrications when their fabrications helped to explain outcomes they had witnessed. In three experiments, we test the generality of the explanatory role hypothesis as a mechanism of eyewitness suggestibility by assessing whether this hypothesis can predict suggestibility errors in (a) situations where the post-event suggestions are provided by the experimenter (as opposed to fabricated by the participant), and (b) across a variety of memory measures and measures of recollective experience. In support of the explanatory role hypothesis, participants were more likely to subsequently freely report (E1) and recollect the suggestions as part of the witnessed event (E2, source test) when the post-event suggestion helped to provide a causal explanation for a witnessed outcome than when it did not serve this explanatory role. Participants were also less likely to recollect the suggestions as part of the witnessed event (on measures of subjective experience) when their explanatory strength had been reduced by the presence of an alternative explanation that could explain the same outcome (E3, source test + warning). Collectively, the results provide strong evidence that the search for explanatory coherence influences people's tendency to misremember witnessing events that were only suggested to them.

  11. Vigilância e busca ativa de casos suspeitos de dengue hemorrágico em Ribeirão Preto, São Paulo

    Directory of Open Access Journals (Sweden)

    Pontes Ricardo José Soares

    1997-01-01

    Full Text Available Um estudo clínico-epidemiológico, do tipo relato de casos, avaliou o sistema de vigilância e busca ativa de casos suspeitos de dengue hemorrágico/síndrome de choque do dengue (DH/SCD durante uma epidemia de dengue no Município de Ribeirão Preto, Estado de São Paulo, Brasil, que ocorreu entre novembro de 1990 e março de 1991. Tratou-se da primeira epidemia de dengue registrada nessa região. Embora o dengue seja um problema de saúde pública crescente no Brasil e o DH/SCD pareça tratar-se de um problema em evolução nas Américas, os serviços de saúde pública demonstram uma atitude passiva diante da ocorrência da doença, em parte como fruto da falta de experiência. A divulgação da ocorrência desta enfermidade, tanto na forma de casos esporádicos como na forma epidêmica, é essencial para a redução da letalidade. Os dados utilizados na presente análise foram coletados pelo sistema oficial de vigilância epidemiológica do Município de Ribeirão Preto durante o período da epidemia. Entre 2 521 casos confirmados de dengue foram identificados 36 casos suspeitos de DH/SCD -- 34 casos de doença febril aguda com manifestações hemorrágicas e 2 óbitos associados ao dengue. Desse conjunto, 12 casos de dengue com manifestações hemorrágicas foram confirmados laboratorialmente. A análise dos dados clínicos, epidemiológicos, laboratoriais e de autópsia dos óbitos associados ao dengue sugeriu tratarem-se de casos de DH/SCD primário. O estudo aqui descrito evidenciou a dificuldade do sistema assistencial de saúde em estabelecer a suspeita clínica de DH/SCD. Isto acarretou demora e inadequação na conduta clínica. Além disso, ficou confirmada a necessidade de um sistema de vigilância epidemiológica ativa permanente, que possibilite a identificação precoce dos casos suspeitos de DH/SCD e viabilize uma ação de controle rápida e adequada.

  12. Dengue endêmico: o desafio das estratégias de vigilância Endemic dengue: surveillance strategy challenges

    Directory of Open Access Journals (Sweden)

    Keyla Belizia Feldman Marzochi

    2004-10-01

    Full Text Available A interação entre infecção clínica, vetor e imunidade sorotípica da população define o risco de epidemia por dengue. A situação epidemiológica endêmico-esporádica seria meta aceitável de controle em regiões metropolitanas ante deficiências de urbanização, saneamento, acesso às residências por agentes sanitários, baixo poder residual de inseticidas biológicos e mobilização social. A Vigilância, então, requererá continuidade das ações públicas e da sociedade em geral, estimuladas na medida inversa da redução de casos, e propostas adequadas. Visando constituir sistema de Vigilância sensível e específico, sobretudo em períodos endêmicos, propõe-se que o componente clínico sentinela deve integrar tanto a assistência emergencial aberta preconizada, detectando casos graves - ponta do iceberg, como serviços de referência para doenças febris agudas, definindo diferentes formas clínicas e propiciando confirmação diagnóstica. Em regiões estratégicas, paralelamente, inquéritos sorotipicos amostrais, embora complexos, devem ser buscados, avaliando imunidade e suscetibilidade de grupos etários aos sorotipos circulantes, estimativa de casos subclínicos e alcance do Sistema de Vigilância e Controle.Interaction between clinical infection, vector, and population serotype immunity defines dengue epidemic risk. An endemic-sporadic epidemiological situation is an acceptable control target in metropolitan regions deficient in urban upgrading, sanitation, and health agents' access to residences, besides low residual power of biological insecticides and social mobilization problems. Surveillance requires continued action by government and society (particularly when incidence decreases and adequate proposals. To establish a sensitive and specific surveillance system for endemic periods, the authors propose the sentinel clinical component as part of emergency care (detecting serious tip-of-the-iceberg cases and

  13. Prospective detection of large prediction errors: a hypothesis testing approach

    International Nuclear Information System (INIS)

    Ruan, Dan

    2010-01-01

    Real-time motion management is important in radiotherapy. In addition to effective monitoring schemes, prediction is required to compensate for system latency, so that treatment can be synchronized with tumor motion. However, it is difficult to predict tumor motion at all times, and it is critical to determine when large prediction errors may occur. Such information can be used to pause the treatment beam or adjust monitoring/prediction schemes. In this study, we propose a hypothesis testing approach for detecting instants corresponding to potentially large prediction errors in real time. We treat the future tumor location as a random variable, and obtain its empirical probability distribution with the kernel density estimation-based method. Under the null hypothesis, the model probability is assumed to be a concentrated Gaussian centered at the prediction output. Under the alternative hypothesis, the model distribution is assumed to be non-informative uniform, which reflects the situation that the future position cannot be inferred reliably. We derive the likelihood ratio test (LRT) for this hypothesis testing problem and show that with the method of moments for estimating the null hypothesis Gaussian parameters, the LRT reduces to a simple test on the empirical variance of the predictive random variable. This conforms to the intuition to expect a (potentially) large prediction error when the estimate is associated with high uncertainty, and to expect an accurate prediction when the uncertainty level is low. We tested the proposed method on patient-derived respiratory traces. The 'ground-truth' prediction error was evaluated by comparing the prediction values with retrospective observations, and the large prediction regions were subsequently delineated by thresholding the prediction errors. The receiver operating characteristic curve was used to describe the performance of the proposed hypothesis testing method. Clinical implication was represented by miss

  14. Mismatch or cumulative stress : Toward an integrated hypothesis of programming effects

    NARCIS (Netherlands)

    Nederhof, Esther; Schmidt, Mathias V.

    2012-01-01

    This paper integrates the cumulative stress hypothesis with the mismatch hypothesis, taking into account individual differences in sensitivity to programming. According to the cumulative stress hypothesis, individuals are more likely to suffer from disease as adversity accumulates. According to the

  15. Rethinking exchange market models as optimization algorithms

    Science.gov (United States)

    Luquini, Evandro; Omar, Nizam

    2018-02-01

    The exchange market model has mainly been used to study the inequality problem. Although the human society inequality problem is very important, the exchange market models dynamics until stationary state and its capability of ranking individuals is interesting in itself. This study considers the hypothesis that the exchange market model could be understood as an optimization procedure. We present herein the implications for algorithmic optimization and also the possibility of a new family of exchange market models

  16. SAR-based change detection using hypothesis testing and Markov random field modelling

    Science.gov (United States)

    Cao, W.; Martinis, S.

    2015-04-01

    The objective of this study is to automatically detect changed areas caused by natural disasters from bi-temporal co-registered and calibrated TerraSAR-X data. The technique in this paper consists of two steps: Firstly, an automatic coarse detection step is applied based on a statistical hypothesis test for initializing the classification. The original analytical formula as proposed in the constant false alarm rate (CFAR) edge detector is reviewed and rewritten in a compact form of the incomplete beta function, which is a builtin routine in commercial scientific software such as MATLAB and IDL. Secondly, a post-classification step is introduced to optimize the noisy classification result in the previous step. Generally, an optimization problem can be formulated as a Markov random field (MRF) on which the quality of a classification is measured by an energy function. The optimal classification based on the MRF is related to the lowest energy value. Previous studies provide methods for the optimization problem using MRFs, such as the iterated conditional modes (ICM) algorithm. Recently, a novel algorithm was presented based on graph-cut theory. This method transforms a MRF to an equivalent graph and solves the optimization problem by a max-flow/min-cut algorithm on the graph. In this study this graph-cut algorithm is applied iteratively to improve the coarse classification. At each iteration the parameters of the energy function for the current classification are set by the logarithmic probability density function (PDF). The relevant parameters are estimated by the method of logarithmic cumulants (MoLC). Experiments are performed using two flood events in Germany and Australia in 2011 and a forest fire on La Palma in 2009 using pre- and post-event TerraSAR-X data. The results show convincing coarse classifications and considerable improvement by the graph-cut post-classification step.

  17. An omnibus test for the global null hypothesis.

    Science.gov (United States)

    Futschik, Andreas; Taus, Thomas; Zehetmayer, Sonja

    2018-01-01

    Global hypothesis tests are a useful tool in the context of clinical trials, genetic studies, or meta-analyses, when researchers are not interested in testing individual hypotheses, but in testing whether none of the hypotheses is false. There are several possibilities how to test the global null hypothesis when the individual null hypotheses are independent. If it is assumed that many of the individual null hypotheses are false, combination tests have been recommended to maximize power. If, however, it is assumed that only one or a few null hypotheses are false, global tests based on individual test statistics are more powerful (e.g. Bonferroni or Simes test). However, usually there is no a priori knowledge on the number of false individual null hypotheses. We therefore propose an omnibus test based on cumulative sums of the transformed p-values. We show that this test yields an impressive overall performance. The proposed method is implemented in an R-package called omnibus.

  18. Discrete causal theory emergent spacetime and the causal metric hypothesis

    CERN Document Server

    Dribus, Benjamin F

    2017-01-01

    This book evaluates and suggests potentially critical improvements to causal set theory, one of the best-motivated approaches to the outstanding problems of fundamental physics. Spacetime structure is of central importance to physics beyond general relativity and the standard model. The causal metric hypothesis treats causal relations as the basis of this structure. The book develops the consequences of this hypothesis under the assumption of a fundamental scale, with smooth spacetime geometry viewed as emergent. This approach resembles causal set theory, but differs in important ways; for example, the relative viewpoint, emphasizing relations between pairs of events, and relationships between pairs of histories, is central. The book culminates in a dynamical law for quantum spacetime, derived via generalized path summation.

  19. A test of the domain-specific acculturation strategy hypothesis.

    Science.gov (United States)

    Miller, Matthew J; Yang, Minji; Lim, Robert H; Hui, Kayi; Choi, Na-Yeun; Fan, Xiaoyan; Lin, Li-Ling; Grome, Rebekah E; Farrell, Jerome A; Blackmon, Sha'kema

    2013-01-01

    Acculturation literature has evolved over the past several decades and has highlighted the dynamic ways in which individuals negotiate experiences in multiple cultural contexts. The present study extends this literature by testing M. J. Miller and R. H. Lim's (2010) domain-specific acculturation strategy hypothesis-that individuals might use different acculturation strategies (i.e., assimilated, bicultural, separated, and marginalized strategies; J. W. Berry, 2003) across behavioral and values domains-in 3 independent cluster analyses with Asian American participants. Present findings supported the domain-specific acculturation strategy hypothesis as 67% to 72% of participants from 3 independent samples using different strategies across behavioral and values domains. Consistent with theory, a number of acculturation strategy cluster group differences emerged across generational status, acculturative stress, mental health symptoms, and attitudes toward seeking professional psychological help. Study limitations and future directions for research are discussed.

  20. Teen Fertility and Gender Inequality in Education: A Contextual Hypothesis

    Directory of Open Access Journals (Sweden)

    C. Shannon Stokes

    2004-12-01

    Full Text Available Previous studies in developed countries have found a micro-level association between teenage fertility and girls' educational attainment but researchers still debate the policy implications of these associations. First, are these associations causal? Second, are they substantively important enough, at the macro-level, to warrant policy attention? In other words, how much would policy efforts to reduce unintended pregnancy among teens pay off in terms of narrowing national gender gaps in educational attainment? Third, under what contexts are these payoffs likely to be important? This paper focuses on the latter two questions. We begin by proposing a contextual hypothesis to explain cross-national variation in the gender-equity payoffs from reducing unintended teen fertility. We then test this hypothesis, using DHS data from 38 countries.