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.

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.

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

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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.

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

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

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.

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.

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.

SOCIAL VIGILANCE OF SCHOOL JOURNALISTS: COGNITIVE ASPECT

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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

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

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...

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

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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.

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

The co-evolution of honesty and strategic vigilance

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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.

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.

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…

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

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...

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.

Morning anaerobic performance is not altered by vigilance impairment.

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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.

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,

Effects of theobromine and caffeine on mood and vigilance.

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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.

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

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)

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.

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.

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

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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].

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

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.

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.

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.

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.

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

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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.

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

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

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

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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.

Neurobehavioral Effects of Space Radiation on Psychomotor Vigilance Tests

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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

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.

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

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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

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

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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.

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

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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.

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...

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

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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.

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

Validation of the Japanese Version of the Body Vigilance Scale.

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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.

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

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

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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.

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...

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

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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.

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.

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

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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.

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

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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.

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

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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

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

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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

EEG predictors of covert vigilant attention

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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.

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...

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

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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.

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

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

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.

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.

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.

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...

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.

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.

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.

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

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…

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.

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.

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

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.

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.

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.

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.

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…

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.

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

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.

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.

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.

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...

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.

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.

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.

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.

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...

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.

Teaching Blended Content Analysis and Critically Vigilant Media Consumption

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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…

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

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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.

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

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

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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.

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

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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.

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

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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

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

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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.

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

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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.

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

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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.

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

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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

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

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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

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

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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.

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

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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.

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

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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.

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

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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

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

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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.

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

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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.

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

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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...

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

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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

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

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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.

Binaural auditory beats affect vigilance performance and mood.

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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.

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

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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.

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

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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.

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

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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.

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

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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.

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

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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.

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

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...

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.

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

Directory of Open Access Journals (Sweden)

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.

[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.

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...

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.

Programa de Educação para o Trabalho e Vigilância em Saúde

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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.

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

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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.

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.

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.

Caminhos possíveis para a avaliação das práticas da Vigilância em Saúde

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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.

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.

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...

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...

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.

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.

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.

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.

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,…

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.

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.

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.

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.

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...

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

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.

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)

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

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.

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

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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

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 ...

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...

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...

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.

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.

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...

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.

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.

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

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.

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.

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...

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.

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

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…

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...

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...

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.

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

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...

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.

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.

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

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...

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

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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.

THE FRACTAL MARKET HYPOTHESIS

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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.

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...

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

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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

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…

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...

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.

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)

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.

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.

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

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.

Análise de situação dos recursos humanos da vigilância sanitária em Salvador - BA, Brasil

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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.

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.

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

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), ...

Vigilant conservatism in evaluating communicated information.

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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.

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.

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.

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.

Desenvolvimento da Vigilância Epidemiológica de Fronteira no contexto da Globalização: conceitos e marcos teóricos.

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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.

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.

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,

Antiaging therapy: a prospective hypothesis

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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

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.

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.

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)

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.

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.

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...

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.

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.

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...

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

Grupo PET-Saúde/Vigilância em Saúde do Trabalhador Portuário: vivência compartilhada

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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.

Hypothesis in research

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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.

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.

Central Plant Optimization for Waste Energy Reduction (CPOWER). ESTCP Cost and Performance Report

Science.gov (United States)

2016-12-01

meet all demands, and not necessarily for fuel economy or energy efficiency. Plant operators run the equipment according to a pre-set, fixed strategy ...exchanger, based on the site protocol. Thermal Energy Storage Tank Site-specific optimal operating strategies were developed for the chilled water...being served by the central plant Hypothesis The hypothesis tested that the optimized operation reduces wasted energy and energy costs by smart

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

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.

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.

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.

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.

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.

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.

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).

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.

Hybrid intelligent control concepts for optimal data fusion

Science.gov (United States)

Llinas, James

1994-02-01

In the post-Cold War era, Naval surface ship operations will be largely conducted in littoral waters to support regional military missions of all types, including humanitarian and evacuation activities, and amphibious mission execution. Under these conditions, surface ships will be much more isolated and vulnerable to a variety of threats, including maneuvering antiship missiles. To deal with these threats, the optimal employment of multiple shipborne sensors for maximum vigilance is paramount. This paper characterizes the sensor management problem as one of intelligent control, identifies some of the key issues in controller design, and presents one approach to controller design which is soon to be implemented and evaluated. It is argued that the complexity and hierarchical nature of problem formulation demands a hybrid combination of knowledge-based methods and scheduling techniques from 'hard' real-time systems theory for its solution.

A model of optimal voluntary muscular control.

Science.gov (United States)

FitzHugh, R

1977-07-19

In the absence of detailed knowledge of how the CNS controls a muscle through its motor fibers, a reasonable hypothesis is that of optimal control. This hypothesis is studied using a simplified mathematical model of a single muscle, based on A.V. Hill's equations, with series elastic element omitted, and with the motor signal represented by a single input variable. Two cost functions were used. The first was total energy expended by the muscle (work plus heat). If the load is a constant force, with no inertia, Hill's optimal velocity of shortening results. If the load includes a mass, analysis by optimal control theory shows that the motor signal to the muscle consists of three phases: (1) maximal stimulation to accelerate the mass to the optimal velocity as quickly as possible, (2) an intermediate level of stimulation to hold the velocity at its optimal value, once reached, and (3) zero stimulation, to permit the mass to slow down, as quickly as possible, to zero velocity at the specified distance shortened. If the latter distance is too small, or the mass too large, the optimal velocity is not reached, and phase (2) is absent. For lengthening, there is no optimal velocity; there are only two phases, zero stimulation followed by maximal stimulation. The second cost function was total time. The optimal control for shortening consists of only phases (1) and (3) above, and is identical to the minimal energy control whenever phase (2) is absent from the latter. Generalization of this model to include viscous loads and a series elastic element are discussed.

A descentralização da Vigilância em Saúde em Minas Gerais: caracterização dos serviços municipais, 2014 | The decentralization of health surveillance in Minas Gerais: characterization of counties’ services, 2014

Directory of Open Access Journals (Sweden)

Lucília Nunes Assis

2017-08-01

Full Text Available Introdução: O Projeto de Fortalecimento da Vigilância em Saúde implantado em 2012, em Minas Gerais, visava a descentralização da Vigilância Sanitária, subsidiada no diagnóstico local. Objetivos: Caracterizar os serviços municipais de Vigilância em Saúde no estado de Minas Gerais em 2014. Método: Estudo transversal que analisou diagnósticos de 527/853 (62% municípios do total do estado de MG. As variáveis comuns às áreas da Vigilância em Saúde foram instrumentos de gestão, financiamento, categoria profissional, qualificação e sistema de informação. Aquelas específicas às áreas da Vigilância em Saúde caracterizaram infraestrutura, serviços de referência e ações. Analisaram-se frequências, medianas, diferenças interquartílicas e coeficiente de Spearman (p< 0,05. Resultados: Observou-se associação entre instrumentos de gestão, disponibilidade de categorias profissionais, sistema de informação e porte populacional (p<0,001. Identificou-se infraestrutura insuficiente nas Vigilâncias Sanitária e Ambiental e predomínio das ações programáticas frente àquelas de monitoramento. Conclusões: O desafio da Vigilância em Saúde demanda enfrentamentos no campo da gestão, das práticas e do financiamento. ==================================================Introduction: The Health Surveillance Strengthening Project implemented in 2012 in Minas Gerais -subsidized by a local diagnosis- aimed at decentralizing Health Surveillance. Objectives: To characterizes the local Health Surveillance services in the state of Minas Gerais in 2014. Method: Descriptive study that analyzed 527 (62% out of a total of 853 counties. The common variables to the Health Surveillance areas were instruments of management, financing, professional category, qualification and information system. Specific variables to the Health Surveillance areas were characterized infrastructure, reference services and actions. Frequencies, medians

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...

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.

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).

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.

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...

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.

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.

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

Dengue endêmico: o desafio das estratégias de vigilância Endemic dengue: surveillance strategy challenges

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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

Behavioural correlates of urbanisation in the Cape ground squirrel Xerus inauris

Science.gov (United States)

Chapman, Tarryn; Rymer, Tasmin; Pillay, Neville

2012-11-01

Urbanisation critically threatens biodiversity because of habitat destruction and novel selection pressures. Some animals can respond to these challenges by modifying their behaviour, particularly anti-predator behaviour, allowing them to persist in heavily transformed urban areas. We investigated whether the anti-predator behaviour of the Cape ground squirrel Xerus inauris differed in three localities that differed in their level of urbanisation. According to the habituation hypothesis, we predicted that ground squirrels in urban areas would: (a) be less vigilant and forage more; (b) trade-off flight/vigilance in favour of foraging; and (c) have shorter flight initiation distances (FID) when approached by a human observer. Observations were made in winter and summer at each locality. As expected, ground squirrels in urbanised areas were less vigilant and had shorter FIDs but did not trade-off between foraging and vigilance. In contrast, a population in a non-urbanised locality showed greater levels of vigilance, FID and traded-off vigilance and foraging. A population in a peri-urban locality showed mixed responses. Our results indicate that Cape ground squirrels reduce their anti-predator behaviour in urban areas and demonstrate a flexible behavioural response to urbanisation.

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.

Parada cardiorrespiratória: vigilância, prevenção e cuidados após PCR / Cardiorespiratory arrest: surveillance, prevention and care after PCR

Directory of Open Access Journals (Sweden)

Diego Bruno Santos Pinheiro

2018-04-01

Full Text Available Reunir produções científicas acerca de ações de vigilância, prevenção e os cuidados de enfermagem na parada cardiorrespiratória. Métodos: Pesquisa bibliográfica nas bases de dados selecionadas LILACS e MEDLINE. Resultados: O resultado da pesquisa bibliográfica conforme indicadores de pesquisa obtiveram-se 22 artigos. Conclusões: A enfermagem é primordial na vigilância e prevenção do paciente, reconhecendo fatores predisponentes que levariam a uma PCR. Durante a PCR, em geral, é a primeira equipe a identificar, acionar o restante dos profissionais e iniciar a RCP. Auxiliam a equipe médica e fazem o registro de enfermagem no prontuário do paciente. O enfermeiro é peça fundamental na distribuição das funções dos demais membros da equipe e nos cuidados após RCP

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.

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.

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...

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

Pode a Vigilância em Saúde ser emancipatória? Um pensamento alternativo de alternativas em tempos de crise

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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.

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...

MORPH INSERTION AND ALLOMORPHY IN OPTIMALITY THEORY

Directory of Open Access Journals (Sweden)

Eulalia Bonet

2004-12-01

Full Text Available The goal of this paper is to compare two different hypotheses about the insertion of morphs and allomorphy in Optimality Theory. One of them, the Morphs through Constraifits Hypothesis (MCH claims that the phonological realization of morphemes (morphs is introduced through language-particular constraints. The other hypothesis, the Morphs in the Input Hypothesis (MIH claims that the inputs to GEN contain al1 the relevant phonological information. It is shown that the MIH is clearly superior to the MCH in accounting for voicing neutralization in languages like Catalan. The two hypotheses seem to fare even in dealing with other phenomena, such as phonologically-conditioned allomorphy or OCP-triggered epenthesis vs. haplology in English possessives and plurals. Finally, although the MCH seems to be a simpler hypothesis for lexical exceptions, it is shown that, when certain aspects are taken into account, it runs into problems.

Validity of Linder Hypothesis in Bric Countries

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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.

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

Descentralização das ações de vigilância epidemiológica em Pernambuco, Brasil

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Ana Coelho de Albuquerque

2015-04-01

Full Text Available O objetivo do estudo foi analisar a relação entre o processo de descentralização da gestão do Sistema Único de Saúde (SUS e o desenvolvimento das ações de vigilância epidemiológica em municípios de Pernambuco, Brasil. A estratégia de trabalho consistiu num estudo descritivo e exploratório qualitativo/quantitativo, com a realização de uma pesquisa de caráter documental e entrevistas semiestruturadas com informantes-chave, como também um estudo ecológico espacial e de série temporal, no qual foi traçada uma série histórica de dez anos (2001-2010, utilizando-se indicadores selecionados. O estudo evidenciou que o processo de descentralização em Pernambuco obteve adesão e evoluiu, porém com a existência de desigualdades e fragilidades no seu desenvolvimento, também apontadas pela oscilação nos resultados da série histórica dos indicadores selecionados. Assim, mesmo que o processo de descentralização das ações de vigilância epidemiológica ainda seja incipiente em alguns municípios, sabe-se que o papel de executor das ações promove o empoderamento do nível municipal, quando o mesmo passa a produzir as informações necessárias à tomada de decisão

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.

Prediction of pilot opinion ratings using an optimal pilot model. [of aircraft handling qualities in multiaxis tasks

Science.gov (United States)

Hess, R. A.

1977-01-01

A brief review of some of the more pertinent applications of analytical pilot models to the prediction of aircraft handling qualities is undertaken. The relative ease with which multiloop piloting tasks can be modeled via the optimal control formulation makes the use of optimal pilot models particularly attractive for handling qualities research. To this end, a rating hypothesis is introduced which relates the numerical pilot opinion rating assigned to a particular vehicle and task to the numerical value of the index of performance resulting from an optimal pilot modeling procedure as applied to that vehicle and task. This hypothesis is tested using data from piloted simulations and is shown to be reasonable. An example concerning a helicopter landing approach is introduced to outline the predictive capability of the rating hypothesis in multiaxis piloting tasks.

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.

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

Descentralização das ações de Vigilância Sanitária nos municípios em Gestão Plena, Estado do Rio de Janeiro Decentralization of Health Surveillance actions in cities with local health managment in the State of Rio de Janeiro

Directory of Open Access Journals (Sweden)

Mirian Miranda Cohen

2004-09-01

Full Text Available O Centro de Vigilância Sanitária da Secretaria de Estado da Saúde do Rio de Janeiro pretende, com a descentralização das ações de vigilância sanitária para os Municípios, atender condições mínimas para fortalecer o sistema estadual de Vigilância Sanitária, criando estrutura de apoio ao processo de descentralização. Este trabalho objetiva apresentar o diagnóstico situacional dos órgãos de vigilância sanitária dos municípios em Gestão Plena do Sistema Municipal, discutindo os principais resultados. A metodologia compreende a análise dos 22 órgãos de vigilância sanitária em Gestão Plena do Sistema Municipal, conforme a Norma Operacional Básica 96, no período de julho a dezembro de 2002, através de questionário padrão aplicado pelo Centro de Vigilância Sanitária e de observação participante. Com base nos resultados, conclui-se que a maioria dos órgãos de vigilância sanitária municipais em Gestão Plena do Sistema Municipal, possuem profundas dificuldades técnico-operacionais no desenvolvimento das ações descentralizadas, denotando a fragilidade do processo de descentralização das ações de Vigilância Sanitária no Estado e a necessidade de sensibilizar os gestores para a efetiva estruturação das vigilâncias sanitárias locais, em parceria com o órgão estadual de Vigilância Sanitária.The Health Surveillance Center of the State of Rio de Janeiro intends, with the decentralization of low complexity health surveillance actions for Cities, to meet the minimum requirements to strengthen the state health surveillance system, creating a support structure for the descentraliztion process. The objective of this paper is to present the situational diagnosis of the health surveillance agencies that have adopted the System Full Management. The methodology encompasses the analysis of 22 municipal health surveillance agencies that use the System Full Management, according to the Unified Health System's Basic

Arousal, anxiety, and performance: a reexamination of the Inverted-U hypothesis.

Science.gov (United States)

Arent, Shawn M; Landers, Daniel M

2003-12-01

Until recently, the traditional Inverted-U hypothesis had been the primary model used by sport psychologists to describe the arousal-performance relationship. However, many sport psychology researchers have challenged this relationship, and the current trend is a shift toward a more "multidimensional" view of arousal-anxiety and its effects on performance. In the current study, 104 college-age participants performed a simple response time task while riding a bicycle ergometer. Participants were randomly assigned to one of eight arousal groups (between 20 and 90% of heart rate reserve) and were told they were competing for a cash prize. Prior to the task, the Competitive State Anxiety Inventory-2 and Sport Anxiety Scale (SAS) were administered to assess the influence of cognitive and somatic anxiety. As hypothesized, regression analysis revealed a significant quadratic trend for arousal and reaction time. This accounted for 13.2% of the variance, F change (1, 101) = 15.10, p performance beyond that accounted for by the nonsignificant linear trend. As predicted by the Inverted-U hypothesis, optimal performance on the simple task was seen at 60 and 70% of maximum arousal. Furthermore, for the simple task used in this study, only somatic anxiety as measured by the SAS accounted for significant variance in performance beyond that accounted for by arousal alone. These findings support predictions of the Inverted-U hypothesis and raise doubts about the utility theories that rely on differentiation of cognitive and somatic anxiety to predict performance on simple tasks that are not cognitively loaded.

The stuff that dreams aren't made of: why wake-state and dream-state sensory experiences differ.

Science.gov (United States)

Symons, D

1993-06-01

It is adaptive for individuals to be continuously alert and responsive to external stimuli (such as the sound and odor of an approaching predator or the cry of an infant), even during sleep. Natural selection thus has disfavored the occurrence during sleep of hallucinations that compromise external vigilance. In the great majority of mammalian species, including Homo sapiens, closed eyes and immobility are basic aspects of sleep. Therefore, (a) visual and movement sensory modalities (except kinesthesis) do not provide the sleeper with accurate information about the external environment or the sleeper's relationship to that environment; (b) the sleeper's forebrain "vigilance mechanism" does not monitor these modalities; hence (c) visual and movement hallucinations--similar or identical to percepts--can occur during sleep without compromising vigilance. In contrast, the other sensory modalities do provide the sleeper with a continuous flow of information about the external environment or the sleeper's relationship to that environment, and these modalities are monitored by the vigilance mechanism. Hallucinations of kinesthesis, pain, touch, warmth, cold, odor, and sound thus would compromise vigilance, and their occurrence during sleep has been disfavored by natural selection. This vigilance hypothesis generates novel predictions about dream phenomenology and REM-state neurophysiology and has implications for the general study of imagery.

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.

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.

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…

Short-Term Wind Speed Forecasting Using Support Vector Regression Optimized by Cuckoo Optimization Algorithm

Directory of Open Access Journals (Sweden)

Jianzhou Wang

2015-01-01

Full Text Available This paper develops an effectively intelligent model to forecast short-term wind speed series. A hybrid forecasting technique is proposed based on recurrence plot (RP and optimized support vector regression (SVR. Wind caused by the interaction of meteorological systems makes itself extremely unsteady and difficult to forecast. To understand the wind system, the wind speed series is analyzed using RP. Then, the SVR model is employed to forecast wind speed, in which the input variables are selected by RP, and two crucial parameters, including the penalties factor and gamma of the kernel function RBF, are optimized by various optimization algorithms. Those optimized algorithms are genetic algorithm (GA, particle swarm optimization algorithm (PSO, and cuckoo optimization algorithm (COA. Finally, the optimized SVR models, including COA-SVR, PSO-SVR, and GA-SVR, are evaluated based on some criteria and a hypothesis test. The experimental results show that (1 analysis of RP reveals that wind speed has short-term predictability on a short-term time scale, (2 the performance of the COA-SVR model is superior to that of the PSO-SVR and GA-SVR methods, especially for the jumping samplings, and (3 the COA-SVR method is statistically robust in multi-step-ahead prediction and can be applied to practical wind farm applications.

Methods for Optimizing CRISPR-Cas9 Genome Editing Specificity

Science.gov (United States)

Tycko, Josh; Myer, Vic E.; Hsu, Patrick D.

2016-01-01

Summary Advances in the development of delivery, repair, and specificity strategies for the CRISPR-Cas9 genome engineering toolbox are helping researchers understand gene function with unprecedented precision and sensitivity. CRISPR-Cas9 also holds enormous therapeutic potential for the treatment of genetic disorders by directly correcting disease-causing mutations. Although the Cas9 protein has been shown to bind and cleave DNA at off-target sites, the field of Cas9 specificity is rapidly progressing with marked improvements in guide RNA selection, protein and guide engineering, novel enzymes, and off-target detection methods. We review important challenges and breakthroughs in the field as a comprehensive practical guide to interested users of genome editing technologies, highlighting key tools and strategies for optimizing specificity. The genome editing community should now strive to standardize such methods for measuring and reporting off-target activity, while keeping in mind that the goal for specificity should be continued improvement and vigilance. PMID:27494557

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

The potential for increased power from combining P-values testing the same hypothesis.

Science.gov (United States)

Ganju, Jitendra; Julie Ma, Guoguang

2017-02-01

The conventional approach to hypothesis testing for formal inference is to prespecify a single test statistic thought to be optimal. However, we usually have more than one test statistic in mind for testing the null hypothesis of no treatment effect but we do not know which one is the most powerful. Rather than relying on a single p-value, combining p-values from prespecified multiple test statistics can be used for inference. Combining functions include Fisher's combination test and the minimum p-value. Using randomization-based tests, the increase in power can be remarkable when compared with a single test and Simes's method. The versatility of the method is that it also applies when the number of covariates exceeds the number of observations. The increase in power is large enough to prefer combined p-values over a single p-value. The limitation is that the method does not provide an unbiased estimator of the treatment effect and does not apply to situations when the model includes treatment by covariate interaction.

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.

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.

Topology optimization for elastic base under rectangular plate subjected to moving load

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Jilavyan Samvel H.

2015-09-01

Full Text Available Distribution optimization of elastic material under elastic isotropic rectangular thin plate subjected to concentrated moving load is investigated in the present paper. The aim of optimization is to damp its vibrations in finite (fixed time. Accepting Kirchhoff hypothesis with respect to the plate and Winkler hypothesis with respect to the base, the mathematical model of the problem is constructed as two-dimensional bilinear equation, i.e. linear in state and control function. The maximal quantity of the base material is taken as optimality criterion to be minimized. The Fourier distributional transform and the Bubnov-Galerkin procedures are used to reduce the problem to integral equality type constraints. The explicit solution in terms of two- dimensional Heaviside‘s function is obtained, describing piecewise-continuous distribution of the material. The determination of the switching points is reduced to a problem of nonlinear programming. Data from numerical analysis are presented.

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

Amostragem por larva-única na vigilância de Aedes aegypti Single-larva sampling for Aedes aegypti surveillance

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José Eduardo Bracco

1995-04-01

Full Text Available Com a finalidade de testar a metodologia de amostragem por larva-única na vigilância entomológica do Aedes aegypti, foram pesquisados domicílios do Município de Araraquara, SP (Brasil. Nos criadouros que continham larvas de Aedes uma delas foi coletada. Como controle, após a coleta da larva-única, todas as larvas foram coletadas para identificação posterior. Esse processo foi repetido no laboratório. Dos 447 domicílios visitados, apenas 12 foram considerados positivos e 20 criadouros foram identificados; destes, 13 continham larvas de Aedes; 5, larvas de Aedes e Culex e 2, larvas de Culex. Os resultados mostram o reconhecimento correto, no campo, de todos os criadouros, evidenciando que o método poderia ser utilizado na vigilância entomológica de municípios sem infestação domiciliar ou infestados apenas com uma única espécie de Aedes.Buildings in Araraquara city, Southeastern Brazil, were searched during a year for the presence of Aedes larvae using single larva sampling in order to check the single-larva methodology. In those breeding places in wich Aedes larvae were found, one of them was collected. As a control, after the single larva had been collected, all the larvae from the breeding place were collected for later identification. This process was repeated in the laboratory. Of the 447 domiciles searched, 12 were considered positive and 20 breeding places were found. Of the breeding places, 13 contained Aedes larvae, 5 both Aedes and Culex larvae and 2 Culex larvae only. The results show that all the breeding places in the field were properly recognited showing the method may be used for Aedes surveillance in cities infested with one species only or without any domiciliary infestation.

Comprometimento organizacional de trabalhadores da vigilância sanitária em municípios do estado de Goiás

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Maria Aparecida de Souza Melo

Full Text Available Trata-se de estudo de campo, com abordagem quantitativa, sobre o nível de comprometimento organizacional de fiscais da vigilância sanitária municipal. Foram analisadas possíveis diferenças entre os grupos amostrais, divididos de acordo com suas características sociodemográficas. Participaram do estudo 335 fiscais de 53 municípios de Goiás, que responderam à Escala de Bases do Comprometimento Organizacional em 2011. A escala aborda sete diferentes tipos de vínculo que os trabalhadores têm em relação à instituição onde trabalham, além de dados pessoais e profissionais. As análises realizadas foram: descritivas, de variância e testes qui-quadrado. Encontrou-se alto comprometimento afetivo e alto sentimento de obrigação pelo desempenho no trabalho, baixos níveis nos sentimentos de afiliação e de obrigação em permanecer trabalhando na vigilância sanitária municipal, bem como diferenças entre grupos quando levadas em conta as características individuais e profissionais. Os gestores públicos da área devem atentar para a importância dos recursos humanos no desenvolvimento das políticas públicas e priorizar ações que resultem em níveis elevados de comprometimento desses profissionais.

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.

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...

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

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.

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

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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.

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

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.

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)

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

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.

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

Construção do Sistema Brasileiro de Vigilância Sanitária: argumentos para debate Construction of the Brazilian Sanitary Surveillance System: arguments to debate

Directory of Open Access Journals (Sweden)

Marismary Horsth De Seta

2010-11-01

Full Text Available Este artigo analisa a construção do Sistema Nacional de Vigilância Sanitária, um arranjo voltado à regulação e redução dos riscos sanitários decorrentes do consumo de produtos, da prestação de serviços de saúde e do ambiente no Brasil. Consideraram-se aspectos históricos, políticos, fiscais e a conjuntura atual para cotejar seu desenvolvimento com o do Sistema Nacional de Vigilância em Saúde, que tem recebido intensa cooperação internacional. O cotejamento se baseou na trajetória de seus sistemas nacionais e respectivos serviços federais, bem como nos critérios para descentralização. A análise teve como categoria central a coordenação federativa e se baseou no referencial do federalismo e das relações intergovernamentais. O contexto institucional da saúde e da vigilância sanitária apresenta forte competição política, instabilidade no projeto e provável redução da capacidade de coordenação federativa após o Pacto pela Saúde. O Sistema Nacional de Vigilância Sanitária, em razão da sua natureza de bem público e da alta externalidade de seu campo de ação, requer coordenação federativa para incremento da cooperação regional e local e também pela heterogeneidade estrutural dos municípios brasileiros.This paper analyzes the Brazilian Sanitary Surveillance System as an arrangement aimed at regulating and reducing health risks associated with consumption of products, use of health services and the environment. Historical, political and tax aspects were considered and their development compared with the National Health Surveillance System, which has received strong international cooperation. The comparison was based on the trajectory of their national systems and related federal agencies, as well as on criteria adopted for decentralization. The central category of analysis is federative coordination and was based on the framework of federalism and intergovernmental relations. The institutional context

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.

Correlations in state space can cause sub-optimal adaptation of optimal feedback control models

OpenAIRE

Aprasoff, Jonathan; Donchin, Opher

2011-01-01

Control of our movements is apparently facilitated by an adaptive internal model in the cerebellum. It was long thought that this internal model implemented an adaptive inverse model and generated motor commands, but recently many reject that idea in favor of a forward model hypothesis. In theory, the forward model predicts upcoming state during reaching movements so the motor cortex can generate appropriate motor commands. Recent computational models of this process rely on the optimal feedb...

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.

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.

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

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.

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.

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.

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

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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.

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...

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

3-minute smartphone-based and tablet-based psychomotor vigilance tests for the assessment of reduced alertness due to sleep deprivation.

Science.gov (United States)

Grant, Devon A; Honn, Kimberly A; Layton, Matthew E; Riedy, Samantha M; Van Dongen, Hans P A

2017-06-01

The psychomotor vigilance test (PVT) is widely used to measure reduced alertness due to sleep loss. Here, two newly developed, 3-min versions of the psychomotor vigilance test, one smartphone-based and the other tablet-based, were validated against a conventional 10-min laptop-based PVT. Sixteen healthy participants (ages 22-40; seven males, nine females) completed a laboratory study, which included a practice and a baseline day, a 38-h total sleep deprivation (TSD) period, and a recovery day, during which they performed the three different versions of the PVT every 3 h. For each version of the PVT, the number of lapses, mean response time (RT), and number of false starts showed statistically significant changes across the sleep deprivation and recovery days. The number of lapses on the laptop was significantly correlated with the numbers of lapses on the smartphone and tablet. The mean RTs were generally faster on the smartphone and tablet than on the laptop. All three versions of the PVT exhibited a time-on-task effect in RTs, modulated by time awake and time of day. False starts were relatively rare on all three PVTs. For the number of lapses, the effect sizes across 38 h of TSD were large for the laptop PVT and medium for the smartphone and tablet PVTs. These results indicate that the 3-min smartphone and tablet PVTs are valid instruments for measuring reduced alertness due to sleep deprivation and restored alertness following recovery sleep. The results also indicate that the loss of sensitivity on the 3-min PVTs may be mitigated by modifying the threshold defining lapses.

Vigilância aos agrotóxicos: quantificação do uso e previsão de impactos na saúde-trabalho-ambiente para os municípios brasileiros

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Wanderlei Pignati

2014-12-01

Full Text Available Como estratégia da vigilância em saúde do trabalhador, população e ambiente, foram analisadas as quantidades, os tipos e a toxicidade de agrotóxicos usados por hectare nas lavouras mato-grossenses para servir de apoio às vigilâncias dos municípios brasileiros. O Brasil cultivou 95 milhões de hectares de lavouras em 2012 e Mato Grosso foi o maior consumidor de agrotóxicos. Utilizaram-se dados do banco informatizado do Instituto de Defesa Agropecuário que registra nas notas fiscais de venda e local de uso e os dados dos receituários agronômicos. Os resultados mostraram que em média um hectare de soja consumiu 12 litros de agrotóxicos, o de milho 6 litros, o de cana 4,8 litros e o de algodão 24 litros. Verificaram-se também os tipos e classes toxicológicas usadas por hectare de cada lavoura. Também, verificou-se, através de uma matriz de produção agropecuária e consumo de pesticidas, que alguns agravos à saúde estão correlacionados com as regiões mais produtoras. A partir dos dados de consumo de agrotóxicos, pela produção agrícola e da toxicidade desses venenos, podem-se inferir seus agravos e danos nos municípios brasileiros e estabelecer estratégias de prevenção e de vigilância à saúde dos trabalhadores, do ambiente e das populações expostas.

The importance of functional form in optimal control solutions of problems in population dynamics

Science.gov (United States)

Runge, M.C.; Johnson, F.A.

2002-01-01

Optimal control theory is finding increased application in both theoretical and applied ecology, and it is a central element of adaptive resource management. One of the steps in an adaptive management process is to develop alternative models of system dynamics, models that are all reasonable in light of available data, but that differ substantially in their implications for optimal control of the resource. We explored how the form of the recruitment and survival functions in a general population model for ducks affected the patterns in the optimal harvest strategy, using a combination of analytical, numerical, and simulation techniques. We compared three relationships between recruitment and population density (linear, exponential, and hyperbolic) and three relationships between survival during the nonharvest season and population density (constant, logistic, and one related to the compensatory harvest mortality hypothesis). We found that the form of the component functions had a dramatic influence on the optimal harvest strategy and the ultimate equilibrium state of the system. For instance, while it is commonly assumed that a compensatory hypothesis leads to higher optimal harvest rates than an additive hypothesis, we found this to depend on the form of the recruitment function, in part because of differences in the optimal steady-state population density. This work has strong direct consequences for those developing alternative models to describe harvested systems, but it is relevant to a larger class of problems applying optimal control at the population level. Often, different functional forms will not be statistically distinguishable in the range of the data. Nevertheless, differences between the functions outside the range of the data can have an important impact on the optimal harvest strategy. Thus, development of alternative models by identifying a single functional form, then choosing different parameter combinations from extremes on the likelihood

Plant Disease Severity Assessment-How Rater Bias, Assessment Method, and Experimental Design Affect Hypothesis Testing and Resource Use Efficiency.

Science.gov (United States)

Chiang, Kuo-Szu; Bock, Clive H; Lee, I-Hsuan; El Jarroudi, Moussa; Delfosse, Philippe

2016-12-01

The effect of rater bias and assessment method on hypothesis testing was studied for representative experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed "balanced" and those with unequal numbers of replicate estimates are termed "unbalanced". The three assessment methods considered were nearest percent estimates (NPEs), an amended 10% incremental scale, and the Horsfall-Barratt (H-B) scale. Estimates of severity of Septoria leaf blotch on leaves of winter wheat were used to develop distributions for a simulation model. The experimental designs are presented here in the context of simulation experiments which consider the optimal design for the number of specimens (individual units sampled) and the number of replicate estimates per specimen for a fixed total number of observations (total sample size for the treatments being compared). The criterion used to gauge each method was the power of the hypothesis test. As expected, at a given fixed number of observations, the balanced experimental designs invariably resulted in a higher power compared with the unbalanced designs at different disease severity means, mean differences, and variances. Based on these results, with unbiased estimates using NPE, the recommended number of replicate estimates taken per specimen is 2 (from a sample of specimens of at least 30), because this conserves resources. Furthermore, for biased estimates, an apparent difference in the power of the hypothesis test was observed between assessment methods and between experimental designs. Results indicated that, regardless of experimental design or rater bias, an amended 10% incremental scale has slightly less power compared with NPEs, and that the H-B scale is more likely than the others to cause a type II error. These results suggest that choice of assessment method, optimizing sample number and number of replicate

A caracterização do risco sanitário nos processos administrativos da vigilância sanitária

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Max Rogério Alves

2012-12-01

Full Text Available Estudo da caracterização do risco sanitário (avaliação e gerenciamento de risco nos processos administrativos da vigilância sanitária, a partir de um estudo de caso relativo ao controle sanitário de portos, aeroportos e fronteiras. A análise de decisões tomadas no âmbito de processos sanitários permitiu evidenciar que o grau de risco é superficialmente tratado neles, inferindo-se que a caracterização do risco nos referidos processos aproxima-se mais da aplicação do senso comum do que de uma abordagem científica.

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

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.

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.

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.

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.

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

A vigilância sanitária em Feira de Santana no processo de descentralização da saúde (1998-2000

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Iraildes Andrade Juliano

Full Text Available Este estudo analisa a organização da Vigilância Sanitária (Visa de Feira de Santana no processo de descentralização da saúde (1998-2000, apontando avanços e limites no cenário local. Trata-se de um estudo exploratório, de abordagem qualitativa, numa perspectiva histórico-social, cujo recorte espacial foi a Divisão de Vigilância Sanitária da Secretaria Municipal de Saúde. Os materiais empíricos foram os depoimentos de gestores, técnicos, inspetores sanitários e fontes documentais. A análise evidenciou a ausência de um projeto político para a gestão descentralizada das ações de Visa no município. Aponta limites: (desarticulação com o nível regional, recursos humanos temporários e sem qualificação técnica, dificuldades na utilização do incentivo financeiro, insuficiência de infra-estrutura e interferências políticas. Destaca avanços: cumprimento da Programação Pactuada e Integrada, cadastramento dos estabelecimentos sujeitos à fiscalização sanitária, articulações interinstitucionais. Esse processo necessita da mobilização de sujeitos sociais com capacidade de vocalização para inscrevê-lo numa agenda de prioridades, em prol da qualidade de vida da população.

A vigilância sanitária em Feira de Santana no processo de descentralização da saúde (1998-2000

Directory of Open Access Journals (Sweden)

Juliano Iraildes Andrade

2004-01-01

Full Text Available Este estudo analisa a organização da Vigilância Sanitária (Visa de Feira de Santana no processo de descentralização da saúde (1998-2000, apontando avanços e limites no cenário local. Trata-se de um estudo exploratório, de abordagem qualitativa, numa perspectiva histórico-social, cujo recorte espacial foi a Divisão de Vigilância Sanitária da Secretaria Municipal de Saúde. Os materiais empíricos foram os depoimentos de gestores, técnicos, inspetores sanitários e fontes documentais. A análise evidenciou a ausência de um projeto político para a gestão descentralizada das ações de Visa no município. Aponta limites: (desarticulação com o nível regional, recursos humanos temporários e sem qualificação técnica, dificuldades na utilização do incentivo financeiro, insuficiência de infra-estrutura e interferências políticas. Destaca avanços: cumprimento da Programação Pactuada e Integrada, cadastramento dos estabelecimentos sujeitos à fiscalização sanitária, articulações interinstitucionais. Esse processo necessita da mobilização de sujeitos sociais com capacidade de vocalização para inscrevê-lo numa agenda de prioridades, em prol da qualidade de vida da população.

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.

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

Science.gov (United States)

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

A vigilância na Atenção Básica à Saúde: perspectivas para o alcance da Vigilância à Saúde La vigilancia en la Atención Basica a la Salud: perspectivas para el alcance de la Vigilancia en Salud The Surveillance in Health Basic: perspectives to reach the Surveillance in Health

Directory of Open Access Journals (Sweden)

Liliam Saldanha Faria

2010-09-01

Full Text Available A Vigilância à Saúde é Modelo Assistencial com potencial para a reorganização dos processos de trabalho. O estudo objetivou identificar e analisar a estruturação das práticas de vigilância na Atenção Básica, em um território do Município de São Paulo. Foram entrevistados 14 sujeitos, de fevereiro a abril de 2006: gerentes e trabalhadores da saúde que atuavam junto à vigilância epidemiológica. Sob o marco da determinação social da saúde-doença, e da concepção materialista de processo de trabalho, verificou-se que o trabalho cotidiano se apresentou fragmentado. Foram identificados como limitantes para a implementação da vigilância à saúde, a precariedade da infra-estrutura, a falta de qualificação profissional apropriada, de incentivo político-gerencial e de participação da população. Conclui-se, mesmo diante de tal situação que, no nível local, há potencial para transformar a organização do trabalho em saúde e atender as necessidades de saúde da população, através da operacionalização Vigilância à Saúde.La Vigilancia en Salud se constituye como un Modelo Asistencial con potencialidad para la reorganización de los procesos de trabajo. Este estudio tuvo como objetivo identificar y analizar la estructura de las acciones de vigilancia en la Atención Básica de Salud en una determinada región de salud de la Municipalidad de São Paulo-Brasil. Fueran entrevistados 14 profesionales de salud, incluyendo gerentes y trabajadores de la vigilancia epidemiologica. Las entrevistas fueran analizadas con base en el marco de la interpretación social de la salud-enfermedad y de la concepción materialista del proceso de trabajo. Se ha verificado que el trabajo se presentó fragmentado. Se ha verificado limitaciones para la implementación de la vigilancia en salud: la precariedad del trabajo en términos de logistica, la falta de formación profesional apropiada, y la falta de incentivo pol

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...

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

Stages in learning motor synergies: a view based on the equilibrium-point hypothesis.

Science.gov (United States)

Latash, Mark L

2010-10-01

This review describes a novel view on stages in motor learning based on recent developments of the notion of synergies, the uncontrolled manifold hypothesis, and the equilibrium-point hypothesis (referent configuration) that allow to merge these notions into a single scheme of motor control. The principle of abundance and the principle of minimal final action form the foundation for analyses of natural motor actions performed by redundant sets of elements. Two main stages of motor learning are introduced corresponding to (1) discovery and strengthening of motor synergies stabilizing salient performance variable(s) and (2) their weakening when other aspects of motor performance are optimized. The first stage may be viewed as consisting of two steps, the elaboration of an adequate referent configuration trajectory and the elaboration of multi-joint (multi-muscle) synergies stabilizing the referent configuration trajectory. Both steps are expected to lead to more variance in the space of elemental variables that is compatible with a desired time profile of the salient performance variable ("good variability"). Adjusting control to other aspects of performance during the second stage (for example, esthetics, energy expenditure, time, fatigue, etc.) may lead to a drop in the "good variability". Experimental support for the suggested scheme is reviewed. Copyright © 2009 Elsevier B.V. All rights reserved.

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

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

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.

Personal Hypothesis Testing: The Role of Consistency and Self-Schema.

Science.gov (United States)

Strohmer, Douglas C.; And Others

1988-01-01

Studied how individuals test hypotheses about themselves. Examined extent to which Snyder's bias toward confirmation persists when negative or nonconsistent personal hypothesis is tested. Found negativity or positivity did not affect hypothesis testing directly, though hypothesis consistency did. Found cognitive schematic variable (vulnerability…

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.

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)

Ações de vigilância para influenza aviária desenvolvida no Brasil, no período de 2004 e 2007

OpenAIRE

Mota,M.A.; Lima,F.S.; Oliveira,P.F.N.; Guimarães,M.P.

2013-01-01

No início dos anos 2000, o Brasil se consolidou como maior exportador mundial de carne de frango, mesmo período em que se observou a emergência global de focos de HPAI. Para assegurar a qualidade sanitária do produto avícola nacional, o Mapa organizou um programa oficial de vigilância para o vírus de IA. Na primeira fase, foram coletados 106.226 soros e 7.017 pools de suabes traqueais e cloacais, provenientes de granjas avícolas de produção comercial intensiva de frangos de corte, no período ...

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.

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

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

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.

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...

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:.

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

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.

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.

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.

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.

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.

Carbon and nutrient use efficiencies optimally balance stoichiometric imbalances

Science.gov (United States)

Manzoni, Stefano; Čapek, Petr; Lindahl, Björn; Mooshammer, Maria; Richter, Andreas; Šantrůčková, Hana

2016-04-01

Decomposer organisms face large stoichiometric imbalances because their food is generally poor in nutrients compared to the decomposer cellular composition. The presence of excess carbon (C) requires adaptations to utilize nutrients effectively while disposing of or investing excess C. As food composition changes, these adaptations lead to variable C- and nutrient-use efficiencies (defined as the ratios of C and nutrients used for growth over the amounts consumed). For organisms to be ecologically competitive, these changes in efficiencies with resource stoichiometry have to balance advantages and disadvantages in an optimal way. We hypothesize that efficiencies are varied so that community growth rate is optimized along stoichiometric gradients of their resources. Building from previous theories, we predict that maximum growth is achieved when C and nutrients are co-limiting, so that the maximum C-use efficiency is reached, and nutrient release is minimized. This optimality principle is expected to be applicable across terrestrial-aquatic borders, to various elements, and at different trophic levels. While the growth rate maximization hypothesis has been evaluated for consumers and predators, in this contribution we test it for terrestrial and aquatic decomposers degrading resources across wide stoichiometry gradients. The optimality hypothesis predicts constant efficiencies at low substrate C:N and C:P, whereas above a stoichiometric threshold, C-use efficiency declines and nitrogen- and phosphorus-use efficiencies increase up to one. Thus, high resource C:N and C:P lead to low C-use efficiency, but effective retention of nitrogen and phosphorus. Predictions are broadly consistent with efficiency trends in decomposer communities across terrestrial and aquatic ecosystems.

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.

PEMBENTUKAN PORTOFOLIO OPTIMAL SAHAM-SAHAM PADA PERIODE BULLISH DI BURSA EFEK INDONESIA

Directory of Open Access Journals (Sweden)

Suramaya Suci Kewal

2013-04-01

Full Text Available Abstrak: Pembentukan Portofolio Optimal Saham-Saham Pada Periode Bullish Di Bursa Efek Indonesia. Penelitian ini dilakukan dengan tujuan untuk menyusun portofolio optimal saham yang tercatat di Bursa Efek Indonesia dengan menggunakan model indeks tunggal pada periode Bullish. Periode penelitian yang digunakan dalam penelitian ini adalah 2009-2011. Hasilnya adalah tersusunnya sebuah portofolio saham yang terdiri dari empat saham, yaitu ASRI (48,72%, INDF (28,24%, BBNI (16,32%, dan BKSL (6.71%. Hasil pengujian hipotesis pertama menunjukkan bahwa ada perbedaan dalam return saham dari portofolio candidate dibandingkan dengan portofolio noncandidate. Hasil pengujian hipotesis kedua menunjukkan bahwa tidak ada perbedaan dalam risiko saham yang termasuk dalam portofolio candidate dibandingkan dengan portofolio noncandidate. Kata kunci: portofolio optimal, model single-index   Abstract: Establishment of Optimal Portfolio Shares On Bullish Period In Indonesia Stock Exchange. This study was conducted in order to establish an optimal portfolio of stocks listed on the Indonesia Stock Exchange using a single index model on Bullish conditions. Period of research used in this study is 2009-2011. The result is the formation of a stock portfolio consisting of four stocks, namely ASRI (48.72%, INDF (28.24%, BBNI (16.32%, and BKSL (6.71%. The test results of the first hypothesis suggests that there are differences in stock returns a stock portfolio of candidates as compared to the noncandidate portfolio. The results of testing the second hypothesis suggests that there is no difference in the risk of stocks included in candidate portfolios as compared to the noncandidate portfolio. Keywords: optimal portfolios, single-index models

Optimal experimental design with R

CERN Document Server

Rasch, Dieter; Verdooren, L R; Gebhardt, Albrecht

2011-01-01

Experimental design is often overlooked in the literature of applied and mathematical statistics: statistics is taught and understood as merely a collection of methods for analyzing data. Consequently, experimenters seldom think about optimal design, including prerequisites such as the necessary sample size needed for a precise answer for an experimental question. Providing a concise introduction to experimental design theory, Optimal Experimental Design with R: Introduces the philosophy of experimental design Provides an easy process for constructing experimental designs and calculating necessary sample size using R programs Teaches by example using a custom made R program package: OPDOE Consisting of detailed, data-rich examples, this book introduces experimenters to the philosophy of experimentation, experimental design, and data collection. It gives researchers and statisticians guidance in the construction of optimum experimental designs using R programs, including sample size calculations, hypothesis te...

Calcium Hypothesis of Alzheimer's disease and brain aging: A framework for integrating new evidence into a comprehensive theory of pathogenesis.

Science.gov (United States)

2017-02-01

This article updates the Calcium Hypothesis of Alzheimer's disease and brain aging on the basis of emerging evidence since 1994 (The present article, with the subtitle "New evidence for a central role of Ca 2+ in neurodegeneration," includes three appendices that provide context and further explanations for the rationale for the revisions in the updated hypothesis-the three appendices are as follows: Appendix I "Emerging concepts on potential pathogenic roles of [Ca 2+ ]," Appendix II "Future studies to validate the central role of dysregulated [Ca 2+ ] in neurodegeneration," and Appendix III "Epilogue: towards a comprehensive hypothesis.") (Marx J. Fresh evidence points to an old suspect: calcium. Science 2007; 318:384-385). The aim is not only to re-evaluate the original key claims of the hypothesis with a critical eye but also to identify gaps in knowledge required to validate relevant claims and delineate additional studies and/or data that are needed. Some of the key challenges for this effort included examination of questions regarding (1) the temporal and spatial relationships of molecular mechanisms that regulate neuronal calcium ion (Ca 2+ ), (2) the role of changes in concentration of calcium ion [Ca 2+ ] in various subcellular compartments of neurons, (3) how alterations in Ca 2+ signaling affect the performance of neurons under various conditions, ranging from optimal functioning in a healthy state to conditions of decline and deterioration in performance during aging and in disease, and (4) new ideas about the contributions of aging, genetic, and environmental factors to the causal relationships between dysregulation of [Ca 2+ ] and the functioning of neurons (see Appendices I and II). The updated Calcium Hypothesis also includes revised postulates that are intended to promote further crucial experiments to confirm or reject the various predictions of the hypothesis (see Appendix III). Copyright © 2016 the Alzheimer's Association. All rights reserved.

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.

Optimal Scale Edge Detection Utilizing Noise within Images

Directory of Open Access Journals (Sweden)

Adnan Khashman

2003-04-01

Full Text Available Edge detection techniques have common problems that include poor edge detection in low contrast images, speed of recognition and high computational cost. An efficient solution to the edge detection of objects in low to high contrast images is scale space analysis. However, this approach is time consuming and computationally expensive. These expenses can be marginally reduced if an optimal scale is found in scale space edge detection. This paper presents a new approach to detecting objects within images using noise within the images. The novel idea is based on selecting one optimal scale for the entire image at which scale space edge detection can be applied. The selection of an ideal scale is based on the hypothesis that "the optimal edge detection scale (ideal scale depends on the noise within an image". This paper aims at providing the experimental evidence on the relationship between the optimal scale and the noise within images.

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

Correlations in state space can cause sub-optimal adaptation of optimal feedback control models.

Science.gov (United States)

Aprasoff, Jonathan; Donchin, Opher

2012-04-01

Control of our movements is apparently facilitated by an adaptive internal model in the cerebellum. It was long thought that this internal model implemented an adaptive inverse model and generated motor commands, but recently many reject that idea in favor of a forward model hypothesis. In theory, the forward model predicts upcoming state during reaching movements so the motor cortex can generate appropriate motor commands. Recent computational models of this process rely on the optimal feedback control (OFC) framework of control theory. OFC is a powerful tool for describing motor control, it does not describe adaptation. Some assume that adaptation of the forward model alone could explain motor adaptation, but this is widely understood to be overly simplistic. However, an adaptive optimal controller is difficult to implement. A reasonable alternative is to allow forward model adaptation to 're-tune' the controller. Our simulations show that, as expected, forward model adaptation alone does not produce optimal trajectories during reaching movements perturbed by force fields. However, they also show that re-optimizing the controller from the forward model can be sub-optimal. This is because, in a system with state correlations or redundancies, accurate prediction requires different information than optimal control. We find that adding noise to the movements that matches noise found in human data is enough to overcome this problem. However, since the state space for control of real movements is far more complex than in our simple simulations, the effects of correlations on re-adaptation of the controller from the forward model cannot be overlooked.

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.

Os "Maria da Penha" : uma etnografia de mecanismos de vigilância e subversão de masculinidade violentas em Belo Horizonte

OpenAIRE

Maciel, Welliton Caixeta

2014-01-01

A vigilância eletrônica de pessoas em situação de cumprimento de medidas judiciais situa-se dentro do debate maior sobre a descarcerização e a construção de políticas públicas de racionalização do poder punitivo. No contexto do direito penal brasileiro e das políticas públicas a que tem dado lastro, consiste basicamente no controle por meio do acoplamento de um dispositivo eletrônico, vulgo 'tornozeleira', no corpo de indivíduos que passam a ser ‘observados* por uma Central de Monitoração cri...

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.

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.

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

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

Metodologia de captura-recaptura: uma opção para a vigilância das doenças não transmissíveis na população idosa

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Cláudia Medina Coeli

Full Text Available A metodologia de captura-recaptura é utilizada na área da ecologia para a estimativa do tamanho de populações de animais selvagens. Esta técnica pode ser empregada no âmbito da epidemiologia para a obtenção de estimativas de doenças transmissíveis e não transmissíveis em uma forma relativamente barata e rápida. Sistemas de vigilância baseados na utilização desta metodologia representam uma alternativa potencial para o monitoramento de doenças não transmissíveis em nosso meio. Este artigo apresenta uma revisão sucinta dos fundamentos da metodologia de captura-recaptura e de suas aplicações no âmbito da epidemiologia. Adicionalmente, é apresentado um modelo teórico para a implantação de um sistema de vigilância do diabetes mellitus na população idosa baseado na utilização de fontes de morbidade e mortalidade usualmente disponíveis em nosso meio e na aplicação da metodologia de captura-recaptura.

Avaliação da qualidade dos dados, valor preditivo positivo, oportunidade e representatividade do sistema de vigilância epidemiológica da dengue no Brasil, 2005 a 2009

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Jakeline Ribeiro Barbosa

Full Text Available OBJETIVO: avaliar a qualidade dos dados, o valor preditivo positivo (VPP, a oportunidade e a representatividade do sistema de vigilância epidemiológica da dengue no Brasil entre 2005 e 2009. MÉTODOS: estudo de avaliação, com análise dos dados de dengue do Sistema de Informação de Agravos de Notificação (Sinan conforme atributos selecionados da metodologia do Centers for Disease Control and Prevention (Atlanta/GA, Estados Unidos da América. RESULTADOS: houve melhora na qualidade dos dados quanto a sua consistência; o VPP dos casos de dengue variou de 34 a 65%; o sistema apresentou uma mediana de oportunidade para notificação dos casos de 3 dias e revelou-se representativo, permitindo conhecer a situação da doença no país. CONCLUSÃO: o sistema de vigilância da dengue no Brasil mostrou-se consistente, com valor preditivo positivo expressivo, oportuno para notificação de casos e representativo, capaz de detectar tendência de mudança no perfil epidemiológico da doença.

Integração entre vigilância sanitária e assistência à saúde da mulher: um estudo sobre a integralidade no SUS Integration of health surveillance and women's health care: a study on comprehensiveness in the Unified National Health System

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Christiane Maia

2010-04-01

Full Text Available A integralidade é um princípio do SUS, com várias perspectivas, entre as quais a da articulação de seus serviços. O debate sobre esse princípio está presente na assistência à saúde, com destaque para a área de Saúde da Mulher, e nas diretrizes da Vigilância Sanitária. Como as duas áreas buscam a qualidade dos serviços de saúde, o objetivo é analisar a integração entre Vigilância Sanitária e assistência à saúde da mulher. Trata-se de estudo de caso, qualitativo, com entrevistas de profissionais de Vigilância Sanitária de serviços de saúde e coordenadores de Saúde da Mulher (CSM. Os achados apontam para isolamento da Vigilância Sanitária nas secretarias de saúde. A importância da integração é citada por CSM, porém não é fácil de ser aplicada. As relações, se ocorrem, são por situações emergenciais. Os trabalhadores de Vigilância Sanitária acham que não há articulação por não haver problemas na Saúde da Mulher que demandem sua participação e que, com inspeções e palestras, estão colaborando com a área. Mostram-se dificuldades à concretização da integralidade, com o desafio de articular ações em saúde, sobretudo para a Vigilância Sanitária.Comprehensiveness is a key principle in Brazil's Unified National Health System (SUS, approached from various perspectives, including linkage between services. The debate on this principle appears in health care, especially in the area of Women's Health, and in Health Surveillance guidelines. Since both areas target quality of health services, the aim of this study is to analyze the integration between Health Surveillance and Women's Health Care. This is a qualitative case study that interviewed Health Surveillance staff in health services and coordinators of Women's Health services. The findings point to the isolation of Health Surveillance within the health secretariats. The importance of integrating the two areas is cited by Women's Health

Modelo de Análise e Prevenção de Acidentes - MAPA: ferramenta para a vigilância em Saúde do trabalhador

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Ildeberto Muniz de Almeida

2014-12-01

Full Text Available A análise de acidentes de trabalho é importante para a vigilância e a prevenção desses eventos. Métodos atuais de análise buscam superar visões reducionistas que enxergam essas ocorrências como eventos simples explicados por erros dos operadores. O objetivo do artigo é analisar o modelo de análise e prevenção de acidentes (MAPA e seu uso em intervenções de vigilância, destacando aspectos vivenciados na apropriação da ferramenta. Optou-se por método descritivo analítico apresentando as etapas do modelo. Para ilustrar contribuições e ou dificuldades foram selecionados casos nos quais foi usada a ferramenta em contexto de serviço. O MAPA integra abordagens teóricas já experimentadas em estudos de acidentes fornecendo apoio conceitual útil desde a etapa de coleta de dados à conclusão e intervenção. Além de revelar fragilidades da abordagem tradicional, ajuda a identificar determinantes organizacionais como falhas gerenciais, de concepção de sistemas e da gestão de segurança envolvidas na acidentalidade. Os principais desafios encontram-se no domínio dos conceitos pelos usuários, na exploração de aspectos organizacionais mais à montante na cadeia de decisões ou em níveis superiores da hierarquia, bem como na intervenção para mudanças nos determinantes destes eventos.

A contribuição dos trabalhadores na consolidação dos serviços municipais de vigilância sanitária

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Garibotti Vanda

2006-01-01

Full Text Available Este estudo teve como objetivo principal aprofundar o conhecimento sobre o papel e as possibilidades de contribuição dos trabalhadores na consolidação dos serviços de vigilância sanitária em três municípios da Região Metropolitana de Porto Alegre, Rio Grande do Sul, Brasil. Trata-se de uma pesquisa qualitativa que utilizou como técnicas o grupo focal e a observação participante. Os dados coletados foram sistematizados e categorizados por meio de análise de conteúdo. Os resultados apontaram a precariedade da gestão dos serviços de vigilância sanitária estudados. Os principais problemas identificados foram deficiências na formação e capacitação dos profissionais, precárias condições de trabalho, falta de autonomia na alocação de recursos e de autogestão do trabalho, além da priorização de ações de caráter restrito, voltadas para o controle e fiscalização de produtos e serviços em detrimento de uma atuação ampliada, dirigida para outros determinantes do processo saúde-doença. Apesar desta realidade, a maioria dos profissionais busca qualificação por conta própria e oscila entre a procura de alternativas para a superação das dificuldades e momentos de frustração e desânimo.

Human Factors Considerations in Migration of Unmanned Aircraft System (UAS) Operator Control

National Research Council Canada - National Science Library

Tvaryanas, Anthony P

2006-01-01

..., or both. There are potential advantages to control migration to include mitigating operator vigilance decrements and fatigue, facilitating operator task specialization, and optimizing workload during multi...

Costs and benefits of realism and optimism.

Science.gov (United States)

Bortolotti, Lisa; Antrobus, Magdalena

2015-03-01

What is the relationship between rationality and mental health? By considering the psychological literature on depressive realism and unrealistic optimism, it was hypothesized that, in the context of judgments about the self, accurate cognitions are psychologically maladaptive and inaccurate cognitions are psychologically adaptive. Recent studies recommend being cautious in drawing any general conclusion about the style of thinking and mental health. Recent investigations suggest that people with depressive symptoms are more accurate than controls in tasks involving time perception and estimates of personal circumstances, but not in other tasks. Unrealistic optimism remains a robust phenomenon across a variety of tasks and domains, and researchers are starting to explore its neural bases. However, the challenge is to determine to what extent and in what way unrealistic optimism is beneficial. We should revisit the hypothesis that optimistic cognitions are psychologically adaptive, whereas realistic thinking is not. Realistic beliefs and expectations can be conducive to wellbeing and good functioning, and wildly optimistic cognitions have considerable psychological costs.

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

Optimal Energy Taxation for Environment and Efficiency

Energy Technology Data Exchange (ETDEWEB)

Pak, Y.D. [Korea Energy Economics Institute, Euiwang (Korea)

2001-11-01

Main purpose of this research is to investigate about how to use energy tax system to reconcile environmental protection and economic growth, and promote sustainable development with the emphasis of double dividend hypothesis. As preliminary work to attain this target, in this limited study I will investigate the specific conditions under which double dividend hypothesis can be valid, and set up the model for optimal energy taxation. The model will be used in the simulation process in the next project. As the beginning part in this research, I provide a brief review about energy taxation policies in Sweden, Netherlands, and the United States. From this review it can be asserted that European countries are more aggressive in the application of environmental taxes like energy taxes for a cleaner environment than the United States. In next part I examined the rationale for optimal environmental taxation in the first-best and the second-best setting. Then I investigated energy taxation how it can provoke various distortions in markets and be connected to the marginal environmental damages and environmental taxation. In the next chapter, I examined the environmentally motivated taxation in the point of optimal commodity taxation view. Also I identified the impacts of environmental taxation in various circumstances intensively to find out when the environment tax can yield double dividend after taking into account of even tax-interaction effects. Then it can be found that even though in general the environmental tax exacerbates the distortion in the market rather than alleviates, it can also improve the welfare and the employment under several specific circumstances which are classified as various inefficiencies in the existing tax system. (author). 30 refs.

Ações de vigilância sanitária no município de Divinópolis, Minas Gerais, entre 2008 e 2013 / Actions of health surveillance in southeast brazilian city from 2008 to 2013

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Suelen Garcia Oliveira da Fonseca

2014-02-01

Full Text Available Os municípios brasileiros apresentam modalidades distintas de organização e gestão pública em virtude das diferentes realidades regionais, o que constitui uma importante estratégia para o planejamento dos serviços de vigilância sanitária. O objetivo deste estudo é descrever e analisar os procedimentos realizados pela Vigilância Sanitária do município de Divinópolis inserido no Sistema de Informações Ambulatoriais (SIA-SUS entre 2008 e 2013. Trata-se de um estudo transversal que utilizou informações do banco de dados eletrônico SIA-SUS e disponibilizado de forma pública através do site DATA/SUS. A partir do Tabnet/Datasus foram acessados os dados da produção ambulatorial do SUS por local de atendimento e forma de organização referente à vigilância sanitária. As informações foram exportadas e organizadas por tipo de atividade para o programa computacional Windows Excel® (versão 2007 para análise descritiva dos dados. De um total de 49 tipos de procedimentos executados pela vigilância sanitária de Divinópolis, 6 (12,24% são relativos a processo administrativo sanitário, 4 (8,16% às atividades educativas, 5 (10,20% são relativos à análise/investigação de surtos e 10 (20,41% à inspeção sanitária. O SIA-SUS é uma ferramenta útil para o desenvolvimento de mecanismos de avaliação do serviço de vigilância sanitária. --------------------------------------------------------------------------- The Brazilian municipalities have distinct modes of organization and public administration owing to differing regional realities, which is an important strategy for the planning of he-alth surveillance services. The aim of this study is to describe and analyse the procedures performed by the Health Surveillance service of Divinópolis inserted into the Ambulatory Information System (SIA-SUS from 2008 to 2013. This was a cross-sectional study that used information from the electronic database SIA-SUS and publicly

Vigilância sanitária em postos de revenda de combustíveis: aplicação de um modelo para integrar ações e promover a saúde do trabalhador

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Isabela Giardini

Full Text Available Resumo Introdução: o benzeno, composto encontrado na gasolina, é reconhecido como agente cancerígeno e tem sido objeto de controle em âmbito mundial devido aos seus efeitos agudos e crônicos à saúde humana. No Brasil, trabalhadores de postos de revenda de combustíveis (PRC são expostos ao benzeno durante suas atividades ocupacionais. A Vigilância Sanitária, ao monitorar a exposição dos trabalhadores ao benzeno, pode avaliar os riscos e implementar estratégias para estabelecer um ambiente de trabalho mais seguro. Objetivo: suscitar a discussão sobre as ações da Vigilância Sanitária em postos de combustíveis baseada na aplicação do modelo Força-Motriz/Pressão/Situação/Exposição/Efeito/Ação (FPSEEA. Método: realização de uma ampla revisão da literatura com a finalidade de obter as informações necessárias para construção e desenvolvimento da matriz proposta no modelo. Discussão: foi possível identificar as deficiências existentes nos diferentes níveis institucionais que possuem suas ações voltadas à proteção da saúde do trabalhador e propor ações para avançar na reflexão sobre o modelo de desenvolvimento, modos de produção e exploração de recursos. Também foram identificadas as possíveis ações da Vigilância Sanitária a serem aplicadas no ambiente ocupacional de PRC para eliminação ou redução dos riscos à saúde aos quais os trabalhadores estão expostos.

Chronic Pain and Selective Attention to Pain Arousing Daily Activity Pictures: Evidence From an Eye Tracking Study

Directory of Open Access Journals (Sweden)

Masoumeh Mahmoodi-Aghdam

2017-11-01

Conclusion: Although these results did not provide unequivocal support for the vigilance-avoidance hypothesis, they are generally consistent with the results of studies using eye tracking technology. Furthermore, our findings put a question over characterization of attentional biases in patients with chronic pain by simply relating that to difficulty in disengaging from pain-related stimuli.

Parents’ Optimism, Positive Parenting, and Child Peer Competence in Mexican-Origin Families

Science.gov (United States)

Castro-Schilo, Laura; Ferrer, Emilio; Taylor, Zoe E.; Robins, Richard W.; Conger, Rand D.; Widaman, Keith F.

2012-01-01

SYNOPSIS Objective This study examined how parents’ optimism influences positive parenting and child peer competence in Mexican-origin families. Design A sample of 521 families (521 mothers, 438 fathers, and 521 11-year-olds) participated in the cross-sectional study. We used structural equation modeling to assess whether effective parenting would mediate the effect of parents’ optimism on child peer competence and whether mothers’ and fathers’ optimism would moderate the relation between positive parenting and child social competence. Results Mothers’ and fathers’ optimism were associated with effective parenting, which in turn was related to children’s peer competence. Mothers’ and fathers’ optimism also moderated the effect of parenting on child peer competence. High levels of parental optimism buffered children against poor parenting; at low levels of parental optimism, positive parenting was more strongly related to child peer competence. Conclusions Results are consistent with the hypothesis that positive parenting is promoted by parents’ optimism and is a proximal driver of child social competence. Parental optimism moderates effects of parenting on child outcomes. PMID:23526877

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.

Valores Organizacionais e do Trabalho: um estudo com vigilantes de uma empresa de terceirização de serviços de vigilância privada de Belo Horizonte

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Paiva, Kely César Martins de

2014-12-01

Full Text Available The general objective of the study was to describe how organizational and work values of vigilants employed by a company that outsources private security services in Belo Horizonte city are configured, in their own perception. The theoretical model adopted was Paiva (2012a,b, based on Oliveira & Tamayo (2004 organizational values model and Porto & Tamayo (2003 work values model. A descriptive field research was performed, with quantitative approach. The unit of analysis was that organization. Already observation units were vigilants crowded in clients in the metropolitan area of the city. Of the total of about 900 vigilantes , 101 answered the questionnaire which data were subjected to univariate and bivariate statistical analysis, using specific softwares (SPSS, Statistical Package for the Social Sciences, version 15; Minitab 14. The organizational values more considered by vigilantes were "conformity", "prestige" , "concern with the community" and "achievement". Regarding work values, "stability" had the highest average, followed by "achievement at work" and "social relations". In general, a certain congruence between organizational values and work was observed. The bivariate analysis showed significant results in several tests and the nature of the activities carried out by vigilantes, as well as some features that are subject of concerns, including formalized legally, explain such results.

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…

Optimality and self-organization in river deltas

Science.gov (United States)

Tejedor, A.; Longjas, A.; Edmonds, D. A.; Zaliapin, I. V.; Georgiou, T. T.; Rinaldo, A.; Foufoula-Georgiou, E.

2017-12-01

Deltas are nourished by channel networks, whose connectivity constrains, if not drives, the evolution, functionality and resilience of these systems. Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. However, in contrast to tributary channel networks, to date, no theory has been proposed to explain how deltas self-organize to distribute water and sediment to the delta top and the shoreline. Here, we hypothesize the existence of an optimality principle underlying the self-organized partition of fluxes in delta channel networks. Specifically, we hypothesize that deltas distribute water and sediment fluxes on a given delta topology such as to maximize the diversity of flux delivery to the shoreline. By introducing the concept of nonlocal Entropy Rate (nER) and analyzing ten field deltas in diverse environments, we present evidence that supports our hypothesis, suggesting that delta networks achieve dynamically accessible maxima of their nER. Furthermore, by analyzing six simulated deltas using the Delf3D model and following their topologic and flux re-organization before and after major avulsions, we further study the evolution of nER and confirm our hypothesis. We discuss how optimal flux distributions in terms of nER, when interpreted in terms of resilience, are configurations that reflect an increased ability to withstand perturbations.

Influence of habitat on behavior of Towndsend's ground squirrels (Spermophilus townsendii)

Science.gov (United States)

Sharpe, Peter B.; Van Horne, Beatrice

1998-01-01

Trade-offs between foraging and predator avoidance may affect an animal's survival and reproduction. These trade-offs may be influenced by differences in vegetative cover, especially if foraging profitability and predation risk differ among habitats. We examined above-ground activity of Townsend's ground squirrels (Spermophilus townsendii) in four habitats in the Snake River Birds of Prey National Conservation Area in southwestern Idaho to determine if behavior of ground squirrels varied among habitats, and we assessed factors that might affect perceived predation risk (i. e. predator detectability, predation pressure, population density). The proportion of time spent in vigilance by ground squirrels in winterfat (Krascheninnikovia lanata) and mosaic habitats of winterfat-sagebrush (Artemisia tridentata) was more than twice that of ground squirrels in burned and unburned sagebrush habitats. We found no evidence for the 'many-eyes' hypothesis as an explanation for differences in vigilance among habitats. Instead, environmental heterogeneity, especially vegetation structure, likely influenced activity budgets of ground squirrels. Differences in vigilance may have been caused by differences in predator detectability and refuge availability, because ground squirrels in the winterfat and mosaic habitats also spent more time in upright vigilant postures than ground squirrels in burned-sagebrush or sagebrush habitats. Such postures may enhance predator detection in low-growing winterfat.

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.

Maximal Repetitions in Written Texts: Finite Energy Hypothesis vs. Strong Hilberg Conjecture

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Łukasz Dębowski

2015-08-01

Full Text Available The article discusses two mutually-incompatible hypotheses about the stochastic mechanism of the generation of texts in natural language, which could be related to entropy. The first hypothesis, the finite energy hypothesis, assumes that texts are generated by a process with exponentially-decaying probabilities. This hypothesis implies a logarithmic upper bound for maximal repetition, as a function of the text length. The second hypothesis, the strong Hilberg conjecture, assumes that the topological entropy grows as a power law. This hypothesis leads to a hyperlogarithmic lower bound for maximal repetition. By a study of 35 written texts in German, English and French, it is found that the hyperlogarithmic growth of maximal repetition holds for natural language. In this way, the finite energy hypothesis is rejected, and the strong Hilberg conjecture is partly corroborated.

The Stoichiometric Divisome: A Hypothesis

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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.

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 ...

A vigilância da qualidade da água para consumo humano: desafios e perspectivas para o Sistema Único de Saúde Surveillance in drinking-water quality: challenges and perspectives for the Brazilian Health System

Directory of Open Access Journals (Sweden)

Marcelo Bessa Freitas

2005-12-01

Full Text Available O controle da qualidade da água de consumo humano se tornou uma ação de saúde pública a partir da década de 1970, quando a portaria No 52 Bsb 77 do Ministério da Saúde instituiu a norma de potabilidade em todo o território nacional. Entretanto, a implementação de um programa de vigilância da qualidade da água só ocorreu a partir da criação do Sistema Nacional de Vigilância Ambiental em Saúde em 1999, e da publicação da portaria 1.469 em 2000. O objetivo deste artigo é discutir os desafios que se colocam para a vigilância da qualidade da água, não só como proposta racionalizadora das ações do Estado, mas como prática sanitária de vigilância em saúde que tenha como perspectiva incorporar a promoção e a proteção da saúde ao conjunto de medidas adotadas pelo SUS, atendendo ainda às seguintes diretrizes: geração de dados, análise e disseminação da informação; descentralização; intersetorialidade e participação da sociedade. O artigo está organizado de modo a descrever, a partir de uma perspectiva histórica, o processo de normatização e regulação da qualidade da água para o consumo humano, abordando os principais desafios e perspectivas da vigilância da qualidade da água no sentido da busca por ações intersetoriais e descentralizadas, abertas a uma gestão participativa voltada para o controle social.The control of the drinking water quality became itself an action of public health from 70's, when the Norm 52 BSB 77, through of Ministry of Health, stated the norm of drinkability of water supply in all country. However, the achievement of a program of drinking water surveillance alone occurred from the creation of the National System of Environmental Health Surveillance in 1999. This paper approach the challenges put on itself by drinking water surveillance as proposals, not just by rationalizing of the Government, but incorporating the perspective of surveillance in health: the promotion and

Avaliação da Vigilância da Síndrome Gripal: estudo de casos em unidade sentinela

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Camila Soares de Vasconcelos

Full Text Available RESUMO O artigo descreve a avaliação de implantação da Vigilância da Síndrome Gripal em Pernambuco por meio de pesquisa avaliativa que compreendeu a determinação do grau de implantação, a análise de contexto político-organizacional e da influência deste sobre o grau. Foram elaborados um modelo lógico e uma matriz de indicadores, e a análise do contexto baseou-se no Triângulo de Governo, de Matus, no projeto de governo, na capacidade de governo e na governabilidade. Identificou-se que a estratégia está implantada em uma das seis unidades avaliadas, que o grau é influenciado de forma variada pelo contexto e que características políticas e organizacionais mais favoráveis podem contribuir para o alcance de graus mais avançados.

Food insecurity as a driver of obesity in humans: The insurance hypothesis.

Science.gov (United States)

Nettle, Daniel; Andrews, Clare; Bateson, Melissa

2017-01-01

Integrative explanations of why obesity is more prevalent in some sectors of the human population than others are lacking. Here, we outline and evaluate one candidate explanation, the insurance hypothesis (IH). The IH is rooted in adaptive evolutionary thinking: The function of storing fat is to provide a buffer against shortfall in the food supply. Thus, individuals should store more fat when they receive cues that access to food is uncertain. Applied to humans, this implies that an important proximate driver of obesity should be food insecurity rather than food abundance per se. We integrate several distinct lines of theory and evidence that bear on this hypothesis. We present a theoretical model that shows it is optimal to store more fat when food access is uncertain, and we review the experimental literature from non-human animals showing that fat reserves increase when access to food is restricted. We provide a meta-analysis of 125 epidemiological studies of the association between perceived food insecurity and high body weight in humans. There is a robust positive association, but it is restricted to adult women in high-income countries. We explore why this could be in light of the IH and our theoretical model. We conclude that although the IH alone cannot explain the distribution of obesity in the human population, it may represent a very important component of a pluralistic explanation. We also discuss insights it may offer into the developmental origins of obesity, dieting-induced weight gain, and anorexia nervosa.

[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.

Optimal Detection under the Restricted Bayesian Criterion

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Shujun Liu

2017-07-01

Full Text Available This paper aims to find a suitable decision rule for a binary composite hypothesis-testing problem with a partial or coarse prior distribution. To alleviate the negative impact of the information uncertainty, a constraint is considered that the maximum conditional risk cannot be greater than a predefined value. Therefore, the objective of this paper becomes to find the optimal decision rule to minimize the Bayes risk under the constraint. By applying the Lagrange duality, the constrained optimization problem is transformed to an unconstrained optimization problem. In doing so, the restricted Bayesian decision rule is obtained as a classical Bayesian decision rule corresponding to a modified prior distribution. Based on this transformation, the optimal restricted Bayesian decision rule is analyzed and the corresponding algorithm is developed. Furthermore, the relation between the Bayes risk and the predefined value of the constraint is also discussed. The Bayes risk obtained via the restricted Bayesian decision rule is a strictly decreasing and convex function of the constraint on the maximum conditional risk. Finally, the numerical results including a detection example are presented and agree with the theoretical results.

On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

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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.

A test of the reward-contrast hypothesis.

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Dalecki, Stefan J; Panoz-Brown, Danielle E; Crystal, Jonathon D

2017-12-01

Source memory, a facet of episodic memory, is the memory of the origin of information. Whereas source memory in rats is sustained for at least a week, spatial memory degraded after approximately a day. Different forgetting functions may suggest that two memory systems (source memory and spatial memory) are dissociated. However, in previous work, the two tasks used baiting conditions consisting of chocolate and chow flavors; notably, the source memory task used the relatively better flavor. Thus, according to the reward-contrast hypothesis, when chocolate and chow were presented within the same context (i.e., within a single radial maze trial), the chocolate location was more memorable than the chow location because of contrast. We tested the reward-contrast hypothesis using baiting configurations designed to produce reward-contrast. The reward-contrast hypothesis predicts that under these conditions, spatial memory will survive a 24-h retention interval. We documented elimination of spatial memory performance after a 24-h retention interval using a reward-contrast baiting pattern. These data suggest that reward contrast does not explain our earlier findings that source memory survives unusually long retention intervals. Copyright © 2017 Elsevier B.V. All rights reserved.

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…

Vigilância para acidentes e violência: instrumento para estratégias de prevenção e controle Injury surveillance: a tool for prevention and control strategies

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Eliseu Alves Waldman

1999-01-01

Full Text Available A rápida e expressiva elevação da morbi-mortalidade por acidentes e violência constituiu um dos pontos mais relevantes da transição epidemiológica no Brasil, a partir dos anos 80. A complexidade do problema implica a aplicação de medidas no âmbito de políticas sociais, elaboração de legislação específica e desenvolvimento de instrumentos de intervenção voltados à prevenção, ao tratamento e à reabilitação dos atingidos, o que pressupõe a identificação de grupos e fatores de risco. O objetivo deste texto é discutir aspectos conceituais e operacionais da utilização da vigilância em eventos adversos à saúde relacionados a acidentes e à violência. Apresentados os conceitos, características comuns e aspectos relativos à operacionalização dos sistemas de vigilância, independente do evento adverso à saúde a que se destinam, foram discutidas algumas questões específicas relativas à elaboração de definições de caso, à identificação de fontes de informação e à coleta dos dados de interesse, buscando identificar diferenças da utilização da vigilância para acidentes e violência se comparadas com a aplicação deste instrumento para doenças infecciosas, salientando entre elas que, para a identificação de fatores de risco, geralmente, se faz necessário complementar os resultados obtidos pela vigilância com pesquisas epidemiológicas.The fast and important increase in morbidity and mortality due to accidents and violence has been one of the most relevant aspects of the epidemiological transition in Brazil since the 80s. This intricate problem calls for social and political measures, and the development of specific legislation and tools for intervening in terms of prevention, treatment, and rehabilitation of those affected, so that risk groups and factors can be identified. The aim of the present paper is to discuss conceptual and operational aspects of using surveillance in adverse health events

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...

P value and the theory of hypothesis testing: an explanation for new researchers.

Science.gov (United States)

Biau, David Jean; Jolles, Brigitte M; Porcher, Raphaël

2010-03-01

In the 1920s, Ronald Fisher developed the theory behind the p value and Jerzy Neyman and Egon Pearson developed the theory of hypothesis testing. These distinct theories have provided researchers important quantitative tools to confirm or refute their hypotheses. The p value is the probability to obtain an effect equal to or more extreme than the one observed presuming the null hypothesis of no effect is true; it gives researchers a measure of the strength of evidence against the null hypothesis. As commonly used, investigators will select a threshold p value below which they will reject the null hypothesis. The theory of hypothesis testing allows researchers to reject a null hypothesis in favor of an alternative hypothesis of some effect. As commonly used, investigators choose Type I error (rejecting the null hypothesis when it is true) and Type II error (accepting the null hypothesis when it is false) levels and determine some critical region. If the test statistic falls into that critical region, the null hypothesis is rejected in favor of the alternative hypothesis. Despite similarities between the two, the p value and the theory of hypothesis testing are different theories that often are misunderstood and confused, leading researchers to improper conclusions. Perhaps the most common misconception is to consider the p value as the probability that the null hypothesis is true rather than the probability of obtaining the difference observed, or one that is more extreme, considering the null is true. Another concern is the risk that an important proportion of statistically significant results are falsely significant. Researchers should have a minimum understanding of these two theories so that they are better able to plan, conduct, interpret, and report scientific experiments.

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.

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.

A proposta da rede de serviços sentinela como estratégia da vigilância de violências e acidentes The injury surveillance system based on sentinel health services

Directory of Open Access Journals (Sweden)

Vilma Pinheiro Gawryszewski

2006-01-01

Full Text Available No Brasil, as bases de dados oficiais permitem o monitoramento da mortalidade e internações no SUS, decorrentes dos acidentes e violências. É preciso conhecer a magnitude e o perfil dessas causas que demandam os serviços de emergência, bem como identificar alguns problemas ocultos tais como as violências doméstica e sexual. O propósito deste artigo é apresentar a proposta do Ministério da Saúde de implantação da Rede de Serviços Sentinela de Vigilância de Violências e Acidentes - Rede VIVA, iniciada em 2006, que visa complementar o sistema de informações existente para a vigilância dessas causas. Para obter um quadro mais completo do problema e atender à legislação vigente no País, foram estabelecidos dois componentes: 1 Vigilância de acidentes e violências em emergências hospitalares selecionadas: coleta em um mês a cada ano, através de uma amostra; 2 Vigilância das violências sexual, doméstica e/ou outras violências interpessoais em serviços de referência: coleta universal e contínua. O estabelecimento da Rede VIVA foi realizado pelo Ministério da Saúde em parceria com as Secretarias Estaduais e Municipais de Saúde a partir de critérios previamente estabelecidos. A adesão ao projeto foi acima das expectativas, todas as regiões do Brasil foram representadas.In Brazil, the official data sets allow monitoring the impact of injury deaths and injury hospitalization in the public health system. But it is necessary to gather more information about the magnitude and the characteristics of injuries at Emergency Departments (ED, as well as to identify some hidden problems, such as domestic and sexual violence. The purpose of this article is to present the new Injury Surveillance System based on Sentinel Health Services, carried out by the Ministry of Health in order to broaden the knowledge of these causes.To have a more accurate picture of injuries and to enforce the law which made mandatory the information

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.

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.

Does Portuguese economy support crude oil conservation hypothesis?

International Nuclear Information System (INIS)

Bashiri Behmiri, Niaz; Pires Manso, José R.

2012-01-01

This paper examines cointegration relationships and Granger causality nexus in a trivariate framework among oil consumption, economic growth and international oil price in Portugal. For this purpose, we employ two Granger causality approaches: the Johansen cointegration test and vector error correction model (VECM) and the Toda–Yamamoto approaches. Cointegration test proves the existence of a long run equilibrium relationship among these variables and VECM and Toda–Yamamoto Granger causality tests indicate that there is bidirectional causality between crude oil consumption and economic growth (feed back hypothesis). Therefore, the Portuguese economy does not support crude oil conservation hypothesis. Consequently, policymakers should consider that implementing oil conservation and environmental policies may negatively impact on the Portuguese economic growth. - Highlights: ► We examine Granger causality among oil consumption, GDP and oil price in Portugal. ► VECM and Toda–Yamamoto tests found bidirectional causality among oil and GDP. ► Portuguese economy does not support the crude oil conservation hypothesis.

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.

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.

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.

Counselor Hypothesis Testing Strategies: The Role of Initial Impressions and Self-Schema.

Science.gov (United States)

Strohmer, Douglas C.; Chiodo, Anthony L.

1984-01-01

Presents two experiments concerning confirmatory bias in the way counselors collect data to test their hypotheses. Counselors were asked either to develop their own clinical hypothesis or were given a hypothesis to test. Confirmatory bias in hypothesis testing was not supported in either experiment. (JAC)

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.

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.

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.

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.

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

The Method of Hypothesis in Plato's Philosophy

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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

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.

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.

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.

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.

Quantitative electroencephalographic measures in homicidal men with antisocial personality disorder.

Science.gov (United States)

Lindberg, Nina; Tani, Pekka; Virkkunen, Matti; Porkka-Heiskanen, Tarja; Appelberg, Björn; Naukkarinen, Hannu; Salmi, Tapani

2005-07-15

Many symptoms of antisocial personality disorder have been proposed to be related to decreased daytime vigilance. To explore this hypothesis, quantitative analyses were conducted of the electroencephalographic (EEG) activity of drug-free and detoxified homicidal male offenders with antisocial personality disorder as the primary diagnosis. Subjects comprised 16 men recruited from a forensic psychiatric examination in a special ward of a university psychiatric hospital. Fifteen healthy age- and gender-matched controls with no criminal record or history of physical violence consisted of hospital staff and students. An overall reduction of alpha power was observed in the waking EEG of offenders. A bilateral increase in occipital delta and theta power was also found in these individuals. This study provides further support to the growing evidence of brain dysfunction in severe aggressive behavior. Homicidal offenders with antisocial personality disorder seem to have difficulties in maintaining normal daytime arousal. Decreased vigilance, together with social and psychological variables, may explain their aberrant behavior in everyday life. New studies are, however, needed to specify the vigilance problems of this patient group.

Costs and benefits of realism and optimism

Science.gov (United States)

Bortolotti, Lisa; Antrobus, Magdalena

2015-01-01

Purpose of review What is the relationship between rationality and mental health? By considering the psychological literature on depressive realism and unrealistic optimism, it was hypothesized that, in the context of judgments about the self, accurate cognitions are psychologically maladaptive and inaccurate cognitions are psychologically adaptive. Recent studies recommend being cautious in drawing any general conclusion about the style of thinking and mental health. Recent findings Recent investigations suggest that people with depressive symptoms are more accurate than controls in tasks involving time perception and estimates of personal circumstances, but not in other tasks. Unrealistic optimism remains a robust phenomenon across a variety of tasks and domains, and researchers are starting to explore its neural bases. However, the challenge is to determine to what extent and in what way unrealistic optimism is beneficial. Summary We should revisit the hypothesis that optimistic cognitions are psychologically adaptive, whereas realistic thinking is not. Realistic beliefs and expectations can be conducive to wellbeing and good functioning, and wildly optimistic cognitions have considerable psychological costs. PMID:25594418

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…

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.

A produção científica e grupos de pesquisa sobre vigilância sanitária no CNPq The scientific production and research groups on sanitary surveillance at CNPq

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Vera Lúcia Edais Pepe

2010-11-01

Full Text Available A vigilância sanitária caracteriza-se por ser prática intersetorial e multidisciplinar, utilizando-se, de longa data, do conhecimento científico produzido em diferentes áreas. Esta pesquisa objetivou descrever a produção científica sobre vigilância sanitária registrada por pesquisadores cadastrados na Plataforma Lattes do CNPq e analisar o perfil dos grupos de pesquisa que trabalham com o tema. Utilizaram-se os Censos de 2000, 2002 e 2004 do Diretório dos Grupos de Pesquisa no Brasil do Conselho Nacional de Desenvolvimento Científico e Tecnológico com o termo "vigilância sanitária". A produção científica foi analisada no período de 1997 a 2003. Encontraram-se 1.194 registros, sendo 913 na categoria de produção bibliográfica e 281 em orientações concluídas, com aumento de 540% no período. A produção foi realizada por 735 grupos de pesquisa, criados principalmente entre 2000 e 2003, e 6.263 pesquisadores, concentrados na região Sudeste e na pequena área da Saúde Coletiva. Conclui-se que, pelo crescimento da produção especialmente na última década, a vigilância sanitária tem se tornado locus de produção de saber e ocupado fóruns importantes de produção científica voltados à Saúde Coletiva no Brasil, sendo ela ainda concentrada, assim como outras áreas na Saúde.Sanitary surveillance is an intersectorial and multidisciplinary practice of health regulation. The aim was to describe the scientific research on sanitary surveillance and its research groups in Brazil during the period of 1997 to 2003, through the Census of 2000, 2002 and 2004 of Directory of Research Groups of the Scientific and Technological Development National Council (CNPq. The term "sanitary surveillance" was used to search the production and the research groups in the Lattes Platform of CNPq. There were 1,194 items, 913 in bibliographic production and 281 in post-graduated production, with an increment of 540% on the period. There were

The Human Release Hypothesis for biological invasions: human activity as a determinant of the abundance of invasive plant species [v1; ref status: indexed, http://f1000r.es/33c

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Heike Zimmermann

2014-05-01

Full Text Available Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density remain poorly understood. Invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the abundance of invasive species may be partly explained by the level of human activity or landscape maintenance, with intermediate levels of human activity providing optimal conditions for high abundance. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important additional or complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability.

Biological fingerprint of high LET radiation. Brenner hypothesis

International Nuclear Information System (INIS)

Kodama, Yoshiaki; Awa, Akio; Nakamura, Nori

1997-01-01

Hypothesis by Brenner et al. (1994) that in chromosome aberrations in human peripheral lymphocytes induced by radiation exposure, F value (dicentrics/rings) differs dependently on the LET and can be a biomarker of high LET radiation like neutron and α-ray was reviewed and evaluated as follows. Radiation and chromosome aberrations; in this section, unstable aberrations like dicentric and rings (r) and stable ones like translocation and pericentric inversions were described. F value. Brenner hypothesis. Bauchinger's refutation. F value determined by FISH method; here, FISH is fluorescence in situ hybridization. F value in studies by author's Radiation Effect Research Facility. Frequency of chromosome aberration in A-bomb survivors and ESR (ESR: electron spin resonance). The cause for fluctuation of F values. The Brenner hypothesis could not be supported by studies by author's facility, suggesting that the rate of inter-chromosomal and intra-chromosomal exchange abnormalities can not be distinguishable by the radiation LET. This might be derived from the difference in detection technology of r rather than in LET. (K.H.)

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....

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.

Footprints of Optimal Protein Assembly Strategies in the Operonic Structure of Prokaryotes

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Jan Ewald

2015-04-01

Full Text Available In this work, we investigate optimality principles behind synthesis strategies for protein complexes using a dynamic optimization approach. We show that the cellular capacity of protein synthesis has a strong influence on optimal synthesis strategies reaching from a simultaneous to a sequential synthesis of the subunits of a protein complex. Sequential synthesis is preferred if protein synthesis is strongly limited, whereas a simultaneous synthesis is optimal in situations with a high protein synthesis capacity. We confirm the predictions of our optimization approach through the analysis of the operonic organization of protein complexes in several hundred prokaryotes. Thereby, we are able to show that cellular protein synthesis capacity is a driving force in the dissolution of operons comprising the subunits of a protein complex. Thus, we also provide a tested hypothesis explaining why the subunits of many prokaryotic protein complexes are distributed across several operons despite the presumably less precise co-regulation.

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.

The Twin Deficits Hypothesis: An Empirical Analysis for Tanzania

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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.

Exposição ao benzeno em postos de combustíveis: estratégia de ações integradas de Vigilância em Saúde do Trabalhador na região dos Vales/RS

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Adriana Skamvetsakis

2017-12-01

Full Text Available Resumo Introdução: O benzeno é uma importante fonte de contaminação ambiental e está presente na composição da gasolina, expondo trabalhadores de Postos de Revenda de Combustíveis (PRC a intoxicações. Objetivo: relatar experiências de vigilância da exposição ao benzeno do Centro de Referência em Saúde do Trabalhador da região dos Vales/RS. Métodos: a vigilância no território incluiu o mapeamento regional dos PRC, ações intrasetoriais, intersetoriais e interinstitucionais, inspeção nos locais de trabalho, desenvolvimento de instrumento de intervenção específico para esse ramo produtivo - Notificação Recomendatória, avaliações individuais dos trabalhadores - e outras abordagens visando intervir nos ambientes com exposição ao benzeno. Resultados: foram observadas alterações em biomarcadores de efeito e de exposição, além de inadequações dos PRC no monitoramento clínico e laboratorial dos trabalhadores. Nos ambientes e processos de trabalho ficaram evidentes situações que ampliam a exposição: inadequações nas pistas de abastecimento, uso de “flanela”, inexistência ou insuficiência de medidas de proteção coletivas, ausência de medição eletrônica dos tanques e de higienização dos uniformes por parte das empresas, dentre outras. Conclusão: as experiências desencadeadas por meio de ações integradas no setor saúde demonstraram a potencialidade benéfica da vigilância da exposição ao benzeno em PRC.

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis.

Science.gov (United States)

Latash, Mark L

2008-01-01

This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time.

A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems

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Kunio Kawamura

2016-08-01

Full Text Available RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes.

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 ...

Review series on helminths, immune modulation and the hygiene hypothesis: the broader implications of the hygiene hypothesis.

Science.gov (United States)

Rook, Graham A W

2009-01-01

Man has moved rapidly from the hunter-gatherer environment to the living conditions of the rich industrialized countries. The hygiene hypothesis suggests that the resulting changed and reduced pattern of exposure to microorganisms has led to disordered regulation of the immune system, and hence to increases in certain inflammatory disorders. The concept began with the allergic disorders, but there are now good reasons for extending it to autoimmunity, inflammatory bowel disease, neuroinflammatory disorders, atherosclerosis, depression associated with raised inflammatory cytokines, and some cancers. This review discusses these possibilities in the context of Darwinian medicine, which uses knowledge of evolution to cast light on human diseases. The Darwinian approach enables one to correctly identify some of the organisms that are important for the 'Hygiene' or 'Old Friends' hypothesis, and to point to the potential exploitation of these organisms or their components in novel types of prophylaxis with applications in several branches of medicine.

Examination of the embargo hypothesis as an explanation for the Great Silence

Science.gov (United States)

Deardorff, J. W.

1987-08-01

The embargo or quarantine hypothesis for explaining the 'Great Silence' is reviewed and found to be more plausible than the view that, at most, earth might expect to receive radio messages from some distant star. The latter hypothesis is shown to be compatible with extraterrestrial technologies only a few hundred years in advance of those on earth, whereas the embargo hypothesis more reasonably infers that they should be tens of thousands of years in advance and in control of any contact with humanity. Reasons why the embargo hypothesis has received insufficient attention are presented; they involve failure to allow for the application of both greatly advanced technology and high ethical values by maturing societies of extraterrestrial intelligence. The implication of the embargo hypothesis for space development is that planets already harboring diverse biota are ethically off-limits for exploitive colonization.

Diálogos de aprendizagem com gestores da vigilância sanitária: percepções do facilitador / Learning dialogues with managers of health surveillance: perceptions of facilitator

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Sergio Ferreira Menezes

2013-08-01

Full Text Available Apresento uma apreciação crítica de ser facilitador ao formar especialistas em Gestão da Vigilância Sanitária, cujo desempenho exigiu habilidades inerentes à metodologia ativa em que o especializando é conduzido a refletir sobre suas práticas nas relações de trabalho. Enfatizo, acima de tudo, a sistematização de saberes e experiência ao desempenhar essa função, que teve por objetivo formar gestores atuantes no sistema. O curso proposto pela Agência Nacional de Vigilância Sanitária foi formulado por expertises da área e coordenado pelo Instituto Sírio Libanês de Ensino e Pesquisa. Tal formulação calcou-se em perfil de competência baseado em três eixos — gestão do risco sanitário, do trabalho e da educação — que delimitam o escopo do trabalho e da atuação profissional. A abordagem construtivista adotada norteia a proposta pedagógica, aplicada com estratégias de aprendizagem baseada em problemas e da problematização, em que o professor assume o papel de facilitador. Ao final do processo analiso a positividade metodológica, visto que a abordagem construtivista permitiu edificar novos saberes que partem das experiências pessoais, tanto do facilitador quanto dos especializandos, além de valorizar criticamente as vivências do trabalho. Especialmente, foi possível observar o aprendizado compartilhado entre os indivíduos, a integração do grupo que possibilitou a (reconstrução de experiências no coletivo, aspectos esses que trazem raros significados para a qualificação dos gestores da vigilância sanitária. --------------------------------------------------------------- Present a critical assessment to be facilitator to train specialists in Management of Health Surveillance, whose performance demanded skills inherent in the active methodology that specializing is led to refl ect on their practices in labor relations. Emphasize, above all, the systematization of knowledge and experience to this

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.

DIO: um jogo em dispositivos móveis para mapear câmeras de vigilância | DIO: a mobile game to map surveillance cameras

OpenAIRE

Rafael de Almeida Evangelista; Tiago Soares; Sarah Costa Schimidt; Felipe Lavignatti

2016-01-01

RESUMO Na sociedade contemporânea, as câmeras de vigilância são tecnologias de uso rápido e crescente. As razões dadas para essa proliferação estão principalmente relacionadas a preocupações com segurança. Nos países pobres, a ênfase está no controle da criminalidade urbana. Nos países ricos, elas são justificadas também pela ameaça do terrorismo. DIO é um jogo para celulares, ainda em desenvolvimento, que tematiza a proliferação das câmeras em áreas urbanas, promovendo um mapeamento colabora...

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...

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…

A Critique of One-Tailed Hypothesis Test Procedures in Business and Economics Statistics Textbooks.

Science.gov (United States)

Liu, Tung; Stone, Courtenay C.

1999-01-01

Surveys introductory business and economics statistics textbooks and finds that they differ over the best way to explain one-tailed hypothesis tests: the simple null-hypothesis approach or the composite null-hypothesis approach. Argues that the composite null-hypothesis approach contains methodological shortcomings that make it more difficult for…

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.

Extraction of airway trees using multiple hypothesis tracking and template matching

DEFF Research Database (Denmark)

Raghavendra, Selvan; Petersen, Jens; Pedersen, Jesper Johannes Holst

2016-01-01

used in constructing a multiple hypothesis tree, which is then traversed to reach decisions. The proposed modifications remove the need for local thresholding of hypotheses as decisions are made entirely based on statistical comparisons involving the hypothesis tree. The results show improvements......Knowledge of airway tree morphology has important clinical applications in diagnosis of chronic obstructive pulmonary disease. We present an automatic tree extraction method based on multiple hypothesis tracking and template matching for this purpose and evaluate its performance on chest CT images...

A naturalização da vigilância no Jornalismo a partir da ubiquidade das Câmeras

Directory of Open Access Journals (Sweden)

Maura Martins

2016-04-01

Full Text Available No presente artigo, pretende-se refletir sobre uma das consequências da onipresença de câmeras na sociedade e da apropriação sistemática de seus registros pelas agendas do telejornalismo: o esgarçamento das fronteiras entre o que se entende por público e privado. Em busca de um enfoque mais preciso a este fenômeno, a análise centraliza-se em uma reportagem, considerada representativa, veiculada pela Rede Record, na qual se assiste ao aproveitamento de um registro feito de modo amador de um flagrante de infração. Deste modo, pretende-se investigar de que forma a popularização de dispositivos que registram o real – motivada por um ideal de atitude cidadã e um discurso de participação ativa do público nas produções jornalísticas - tem impulsionado a naturalização da vigilância distribuída (Bruno, 2013 como um modo de pertencimento à cultura.

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.

On the validity of Taylor's hypothesis for wall-bounded flows

International Nuclear Information System (INIS)

Piomelli, U.; Balint, J.; Wallace, J.M.

1989-01-01

The results of large eddy simulation (LES) of the Navier--Stokes equations are used to evaluate the validity of Taylor's hypothesis of frozen turbulence, which states that the time derivative of some instantaneous quantity is proportional to its derivative in the streamwise direction, for incompressible plane channel flow. Time and space derivatives in the streamwise direction of the velocity components are, in fact, found to be well correlated. Root-mean-square fluctuations of the terms in Taylor's hypothesis also support the validity of this hypothesis above the buffer layer. The good agreement between LES and experimental results indicates that errors in the evaluation of derivatives in the streamwise direction are due mostly to insufficient resolution

A critique of statistical hypothesis testing in clinical research

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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.

Geographic variation in chin shape challenges the universal facial attractiveness hypothesis.

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Zaneta M Thayer

Full Text Available The universal facial attractiveness (UFA hypothesis proposes that some facial features are universally preferred because they are reliable signals of mate quality. The primary evidence for this hypothesis comes from cross-cultural studies of perceived attractiveness. However, these studies do not directly address patterns of morphological variation at the population level. An unanswered question is therefore: Are universally preferred facial phenotypes geographically invariant, as the UFA hypothesis implies? The purpose of our study is to evaluate this often overlooked aspect of the UFA hypothesis by examining patterns of geographic variation in chin shape. We collected symphyseal outlines from 180 recent human mandibles (90 male, 90 female representing nine geographic regions. Elliptical Fourier functions analysis was used to quantify chin shape, and principle components analysis was used to compute shape descriptors. In contrast to the expectations of the UFA hypothesis, we found significant geographic differences in male and female chin shape. These findings are consistent with region-specific sexual selection and/or random genetic drift, but not universal sexual selection. We recommend that future studies of facial attractiveness take into consideration patterns of morphological variation within and between diverse human populations.

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

The optimism trap: Migrants' educational choices in stratified education systems.

Science.gov (United States)

Tjaden, Jasper Dag; Hunkler, Christian

2017-09-01

Immigrant children's ambitious educational choices have often been linked to their families' high level of optimism and motivation for upward mobility. However, previous research has mostly neglected alternative explanations such as information asymmetries or anticipated discrimination. Moreover, immigrant children's higher dropout rates at the higher secondary and university level suggest that low performing migrant students could have benefitted more from pursuing less ambitious tracks, especially in countries that offer viable vocational alternatives. We examine ethnic minority's educational choices using a sample of academically low performing, lower secondary school students in Germany's highly stratified education system. We find that their families' optimism diverts migrant students from viable vocational alternatives. Information asymmetries and anticipated discrimination do not explain their high educational ambitions. While our findings further support the immigrant optimism hypothesis, we discuss how its effect may have different implications depending on the education system. Copyright © 2017. Published by Elsevier Inc.

Da vigilância para prevenção de acidentes de trabalho: contribuição da ergonomia da atividade From surveillance to work-related accident prevention: the contribution of the ergonomics of the activity

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Rodolfo Andrade de Gouveia Vilela

2012-10-01

Full Text Available Os acidentes são fenômenos complexos, cuja determinação situa-se na organização do trabalho, dimensão invisível aos agentes de vigilância. O objetivo deste artigo é analisar e comparar o alcance das intervenções realizadas em uma empresa frigorífica, em 1997, baseada na checagem de normas de saúde e segurança, e em 2008, quando se incorpora a ergonomia da atividade. Foi realizado estudo de caso com análise documental referente à intervenção de 1997 e análise ergonômica do trabalho adotada em 2008. Em 1997 as ações de vigilância incidiram principalmente sobre os fatores de risco visíveis. Mesmo cumprindo as exigências, a empresa continuava, em 2008, com proporção de incidência anual de 26% de acidentes, o que motivou a busca da nova abordagem. Verificou-se, em 2008, que a gênese dos acidentes era provocada por um circulo vicioso: trabalho intenso; inadequação de meios técnicos; absenteísmo e rotatividade (84% ao ano com recrutamento de inexperientes. Esse quadro é agravado por práticas autoritárias. A ergonomia da atividade contribuiu para compreender as causas organizacionais ultrapassando os aspectos normativos da vigilância tradicional, o que indica sua importância para tornar mais efetivas as ações de vigilância para a prevenção.Work-related accidents are complex phenomena determined by the work organization process, the dimensions of which are usually invisible to surveillance agents. The scope of this paper was a case study based on documentary evidence to analyze and compare the success of an intervention conducted at a meat processing and packaging factory, by focusing on checking health and safety norms in 1997, and incorporating ergonomic concepts in 2008. In 1997, surveillance actions focused primarily on visible risk factors. Despite fulfilling sanitation requirements, the company still had an annual accident rate of 26% in 2008, which motivated the search for a new approach. In 2008, it was

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...

Birth weight and perinatal mortality: A comparison of "optimal" birth weight in seven western European countries

NARCIS (Netherlands)

Graafmans, W.C.; Richardus, J.H.; Borsboom, G.J.J.M.; Bakketeig, L.; Langhoff-Roos, J.; Bergsjø, P.; Macfarlane, A.; Verloove-Vanhorick, P.; Mackenbach, J.; Aelvoet, W.; Alderdice, F.; Amelink, M.; Bakoula, C.; Blondel, B.; Bødker, B.; Bolumar, F.; Davidson, L.; Gissler, M.; Hartikainen, A.L.; Holt, J.; Kaminski, M.; Leidinger, J.; Lekea, V.; Lindmark, G.; Masuy-Stroobant, G.; Pal, K. van der; Penney, G.; Purificação Araújo, M. Da; Rantakallio, P.; Rebagliato, M.

2002-01-01

Background. Previous studies have suggested that a population's entire birth weight distribution may be shifted towards higher or lower birth weights, and that optimal birth weight may be lower in populations with a lower average birth weight. We evaluated this hypothesis for seven western European

The Cognitive Mediation Hypothesis Revisited: An Empirical Response to Methodological and Theoretical Criticism.

Science.gov (United States)

Romero, Anna A.; And Others

1996-01-01

In order to address criticisms raised against the cognitive mediation hypothesis, three experiments were conducted to develop a more direct test of the hypothesis. Taken together, the three experiments provide converging support for the cognitive mediation hypothesis, reconfirming the central role of cognition in the persuasion process.…

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.

Do the Emotional Benefits of Optimism Vary Across Older Adulthood? A Life Span Perspective.

Science.gov (United States)

Wrosch, Carsten; Jobin, Joelle; Scheier, Michael F

2017-06-01

This study examined whether the emotional benefits of dispositional optimism for managing stressful encounters decrease across older adulthood. Such an effect might emerge because age-related declines in opportunities for overcoming stressors could reduce the effectiveness of optimism. This hypothesis was tested in a 6-year longitudinal study of 171 community-dwelling older adults (age range = 64-90 years). Hierarchical linear models showed that dispositional optimism protected relatively young participants from exhibiting elevations in depressive symptoms over time, but that these benefits became increasingly reduced among their older counterparts. Moreover, the findings showed that an age-related association between optimism and depressive symptoms was observed particularly during periods of enhanced, as compared to reduced, stress. These results suggest that dispositional optimism protects emotional well-being during the early phases of older adulthood, but that its effects are reduced in advanced old age. © 2016 Wiley Periodicals, Inc.

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

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.

A Vigilância Sanitária no controle de riscos potenciais em serviços de hemoterapia no Brasil

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João Batista Silva Júnior

Full Text Available RESUMO O artigo descreve a situação sanitária dos serviços de hemoterapia avaliados pela Vigilância Sanitária em 2011 e 2012 por meio do Método de Avaliação de Risco Potencial de Serviços de Hemoterapia (MARPSH, classificando-os em cinco categorias: Baixo, Médio-Baixo, Médio, Médio-Alto e Alto. Dos 560 avaliados, houve acréscimo de 9% nos classificados como de baixo risco e queda de 6% entre os de alto. Os principais problemas foram encontrados na região Norte, em agências transfusionais e serviços públicos. Destacaram-se não conformidades relacionadas à gestão da qualidade, de pessoal e de equipamentos. Apesar das melhorias observadas, notaram-se serviços críticos com comprometimento à segurança e à eficácia dos produtos e serviços.

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.

Visual perception and imagery: a new molecular hypothesis.

Science.gov (United States)

Bókkon, I

2009-05-01

Here, we put forward a redox molecular hypothesis about the natural biophysical substrate of visual perception and visual imagery. This hypothesis is based on the redox and bioluminescent processes of neuronal cells in retinotopically organized cytochrome oxidase-rich visual areas. Our hypothesis is in line with the functional roles of reactive oxygen and nitrogen species in living cells that are not part of haphazard process, but rather a very strict mechanism used in signaling pathways. We point out that there is a direct relationship between neuronal activity and the biophoton emission process in the brain. Electrical and biochemical processes in the brain represent sensory information from the external world. During encoding or retrieval of information, electrical signals of neurons can be converted into synchronized biophoton signals by bioluminescent radical and non-radical processes. Therefore, information in the brain appears not only as an electrical (chemical) signal but also as a regulated biophoton (weak optical) signal inside neurons. During visual perception, the topological distribution of photon stimuli on the retina is represented by electrical neuronal activity in retinotopically organized visual areas. These retinotopic electrical signals in visual neurons can be converted into synchronized biophoton signals by radical and non-radical processes in retinotopically organized mitochondria-rich areas. As a result, regulated bioluminescent biophotons can create intrinsic pictures (depictive representation) in retinotopically organized cytochrome oxidase-rich visual areas during visual imagery and visual perception. The long-term visual memory is interpreted as epigenetic information regulated by free radicals and redox processes. This hypothesis does not claim to solve the secret of consciousness, but proposes that the evolution of higher levels of complexity made the intrinsic picture representation of the external visual world possible by regulated

Some consequences of using the Horsfall-Barratt scale for hypothesis testing

Science.gov (United States)

Comparing treatment effects by hypothesis testing is a common practice in plant pathology. Nearest percent estimates (NPEs) of disease severity were compared to Horsfall-Barratt (H-B) scale data to explore whether there was an effect of assessment method on hypothesis testing. A simulation model ba...

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

In Search of the Optimal Path: How Learners at Task Use an Online Dictionary

Science.gov (United States)

Hamel, Marie-Josee

2012-01-01

We have analyzed circa 180 navigation paths followed by six learners while they performed three language encoding tasks at the computer using an online dictionary prototype. Our hypothesis was that learners who follow an "optimal path" while navigating within the dictionary, using its search and look-up functions, would have a high chance of…

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

Suitable or optimal noise benefits in signal detection

International Nuclear Information System (INIS)

Liu, Shujun; Yang, Ting; Tang, Mingchun; Wang, Pin; Zhang, Xinzheng

2016-01-01

Highlights: • Six intervals of additive noises divided according to the two constraints. • Derivation of the suitable additive noise to meet the two constraints. • Formulation of the suitable noise for improvability or nonimprovability. • Optimal noises to minimize P FA , maximize P D and maximize the overall improvement. - Abstract: We present an effective way to generate the suitable or the optimal additive noises which can achieve the three goals of the noise enhanced detectability, i.e., the maximum detection probability (P D ), the minimum false alarm probability (P FA ) and the maximum overall improvement of P D and P FA , without increasing P FA and decreasing P D in a binary hypothesis testing problem. The mechanism of our method is that we divide the discrete vectors into six intervals and choose the useful or partial useful vectors from these intervals to form the additive noise according to different requirements. The form of the optimal noise is derived and proven as a randomization of no more than two discrete vectors in our way. Moreover, how to choose suitable and optimal noises from the six intervals are given. Finally, numerous examples are presented to illustrate the theoretical analysis, where the background noises are Gaussian, symmetric and asymmetric Gaussian mixture noise, respectively.

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

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

Qualidade de Vida na Palma da Mão: tecnologias móveis digitais, vigilância e visibilidade na busca pelo bem-estar

Directory of Open Access Journals (Sweden)

Erika Oikawa

2013-12-01

Full Text Available Este trabalho busca refletir como as tecnologias móveis digitais são apropriadas no cotidiano das pessoas na busca pelo bem-estar individual e coletivo, analisando-se principalmente a possibilidade desses dispositivos em promover interações ubíquas e possibilitar a formação de smart mobs. Para isso, primeiramente, apresenta-se um panorama geral sobre como essas tecnologias vêm transformando a vida social contemporânea. Em seguida, reflete-se sobre como características desses dispositivos móveis podem ajudar a alcançar as metas de uma vida mais regrada, por possibilitarem uma interação constante entre pessoas com os mesmos objetivos, e, ao mesmo tempo, promover um regime de visibilidade e vigilância permanente.

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…

From heresy to dogma in accounts of opposition to Howard Temin's DNA provirus hypothesis.

Science.gov (United States)

Marcum, James A

2002-01-01

In 1964 the Wisconsin virologist Howard Temin proposed the DNA provirus hypothesis to explain the mechanism by which a cancer-producing virus containing only RNA infects and transforms cells. His hypothesis reversed the flow of genetic information, as ordained by the central dogma of molecular biology. Although there was initial opposition to his hypothesis it was widely accepted, after the discovery of reverse transcriptase in 1970. Most accounts of Temin's hypothesis after the discovery portray the hypothesis as heretical, because it challenged the central dogma. Temin himself in his Nobel Prize speech of 1975 narrates a similar story about its reception. But are these accounts warranted? I argue that members of the virology community opposed Temin's provirus hypothesis not simply because it was a counterexample to the central dogma, but more importantly because his experimental evidence for supporting it was inconclusive. Furthermore, I propose that these accounts of opposition to the DNA provirus hypothesis as heretical, written by Temin and others after the discovery of reverse transcriptase, played a significant role in establishing retrovirology as a specialized field.

The limits to pride: A test of the pro-anorexia hypothesis.

Science.gov (United States)

Cornelius, Talea; Blanton, Hart

2016-01-01

Many social psychological models propose that positive self-conceptions promote self-esteem. An extreme version of this hypothesis is advanced in "pro-anorexia" communities: identifying with anorexia, in conjunction with disordered eating, can lead to higher self-esteem. The current study empirically tested this hypothesis. Results challenge the pro-anorexia hypothesis. Although those with higher levels of pro-anorexia identification trended towards higher self-esteem with increased disordered eating, this did not overcome the strong negative main effect of pro-anorexia identification. These data suggest a more effective strategy for promoting self-esteem is to encourage rejection of disordered eating and an anorexic identity.

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

OpenAIRE

Latash, Mark L.

2008-01-01

This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of m...

Testing hypotheses and the advancement of science: recent attempts to falsify the equilibrium point hypothesis.

Science.gov (United States)

Feldman, Anatol G; Latash, Mark L

2005-02-01

Criticisms of the equilibrium point (EP) hypothesis have recently appeared that are based on misunderstandings of some of its central notions. Starting from such interpretations of the hypothesis, incorrect predictions are made and tested. When the incorrect predictions prove false, the hypothesis is claimed to be falsified. In particular, the hypothesis has been rejected based on the wrong assumptions that it conflicts with empirically defined joint stiffness values or that it is incompatible with violations of equifinality under certain velocity-dependent perturbations. Typically, such attempts use notions describing the control of movements of artificial systems in place of physiologically relevant ones. While appreciating constructive criticisms of the EP hypothesis, we feel that incorrect interpretations have to be clarified by reiterating what the EP hypothesis does and does not predict. We conclude that the recent claims of falsifying the EP hypothesis and the calls for its replacement by EMG-force control hypothesis are unsubstantiated. The EP hypothesis goes far beyond the EMG-force control view. In particular, the former offers a resolution for the famous posture-movement paradox while the latter fails to resolve it.

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

Analysis of Various Multi-Objective Optimization Evolutionary Algorithms for Monte Carlo Treatment Planning System

CERN Document Server

Tydrichova, Magdalena

2017-01-01

In this project, various available multi-objective optimization evolutionary algorithms were compared considering their performance and distribution of solutions. The main goal was to select the most suitable algorithms for applications in cancer hadron therapy planning. For our purposes, a complex testing and analysis software was developed. Also, many conclusions and hypothesis have been done for the further research.

Comunicação, vigilância e infraestrutura: tecnopolíticas do espectro eletromagnético | Communication, surveillance and infrastructure: techno-politics of the electromagnetic spectrum

Directory of Open Access Journals (Sweden)

Adriano Belisário

2016-11-01

Full Text Available RESUMO Este trabalho analisa algumas dinâmicas técnicas e políticas em torno dos usos e aplicações do espectro eletromagnético. Argumentando que a vigilância é parte intrínseca do desenvolvimento de certo modelo e arquitetura tecnológica em um nível infraestrutural, exploramos conceitos e práticas que buscam novas perspectivas de entendimento e ação dentro dessa camada essencial para os processos de comunicação que é o espectro. Iniciamos apresentando o espectro radioelétrico e seu gerenciamento para em seguida debater a noção de “espectro aberto” e seus usos mais recentes. Ao final, apresentamos exemplos que ilustram concepções alternativas técnicas e políticas por meio da noção de “espectro livre”. Palavras-Chave: Vigilância; Comunicação; Rádio; Espectro Eletromagnético; Tecnologia. ABSTRACT This paper examines technical and political dynamics around the uses and applications of the electromagnetic spectrum. Arguing that surveillance is an intrinsic part of the development of a certain technological model and architecture at an infrastructural level, we explore concepts and practices that seek new prospects for understanding and acting in this essential layer for communication processes that is the spectrum. We begin presenting the radio spectrum and its management to then discuss the notion of 'open spectrum' and its most recent uses. At the end, we present examples that illustrate alternative technical and political conceptions by means of the notion of a "free spectrum". Keywords: Surveillance; Communication; Radio, Electromagnetic Spectrum; Technology.

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.

Testing the Cross-Racial Generality of Spearman's Hypothesis in Two Samples

Science.gov (United States)

Hartmann, Peter; Kruuse, Nanna Hye Sun; Nyborg, Helmuth

2007-01-01

Spearman's hypothesis states that racial differences in IQ between Blacks (B) and Whites (W) are due primarily to differences in the "g" factor. This hypothesis is often confirmed, but it is less certain whether it generalizes to other races. We therefore tested its cross-racial generality by comparing American subjects of European…

HIV prevention fatigue and HIV treatment optimism among young men who have sex with men

Science.gov (United States)

Macapagal, Kathryn; Birkett, Michelle; Janulis, Patrick; Garofalo, Robert; Mustanski, Brian

2017-01-01

HIV prevention fatigue (the sense that prevention messages are tiresome) and being overly optimistic about HIV treatments are hypothesized to increase HIV risk behavior. Little research has examined these constructs and their correlates among young men who have sex with men (YMSM), who are at high risk for HIV. YMSM (N = 352; M age = 20; 50% Black) completed measures of prevention fatigue, treatment optimism, HIV risk behaviors, and HIV-related knowledge and attitudes during a longitudinal study. Overall, YMSM reported low levels of HIV prevention fatigue and treatment optimism. Path analysis (n = 307) indicated that greater prevention fatigue and treatment optimism predicted higher rates of condomless sex, but condomless sex did not predict later increases in prevention fatigue or treatment optimism. Results are inconsistent with the hypothesis of high prevention fatigue and treatment optimism among YMSM and point to potential causal relationships among these variables and condomless sex. PMID:28825861

[Synopsis about the hypothesis of "information channel" of channel-collateral system].

Science.gov (United States)

Chang, Xi-Lang

2008-10-01

The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

Raison d’être of insulin resistance: the adjustable threshold hypothesis

OpenAIRE

Wang, Guanyu

2014-01-01

The epidemics of obesity and diabetes demand a deeper understanding of insulin resistance, for which the adjustable threshold hypothesis is formed in this paper. To test the hypothesis, mathematical modelling was used to analyse clinical data and to simulate biological processes at both molecular and organismal levels. I found that insulin resistance roots in the thresholds of the cell's bistable response. By assuming heterogeneity of the thresholds, single cells' all-or-none response can col...

Applicability of Taylor's hypothesis in thermally driven turbulence

Science.gov (United States)

Kumar, Abhishek; Verma, Mahendra K.

2018-04-01

In this paper, we show that, in the presence of large-scale circulation (LSC), Taylor's hypothesis can be invoked to deduce the energy spectrum in thermal convection using real-space probes, a popular experimental tool. We perform numerical simulation of turbulent convection in a cube and observe that the velocity field follows Kolmogorov's spectrum (k-5/3). We also record the velocity time series using real-space probes near the lateral walls. The corresponding frequency spectrum exhibits Kolmogorov's spectrum (f-5/3), thus validating Taylor's hypothesis with the steady LSC playing the role of a mean velocity field. The aforementioned findings based on real-space probes provide valuable inputs for experimental measurements used for studying the spectrum of convective turbulence.

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.

Risk-sensitive optimal feedback control accounts for sensorimotor behavior under uncertainty.

Directory of Open Access Journals (Sweden)

Arne J Nagengast

2010-07-01

Full Text Available Many aspects of human motor behavior can be understood using optimality principles such as optimal feedback control. However, these proposed optimal control models are risk-neutral; that is, they are indifferent to the variability of the movement cost. Here, we propose the use of a risk-sensitive optimal controller that incorporates movement cost variance either as an added cost (risk-averse controller or as an added value (risk-seeking controller to model human motor behavior in the face of uncertainty. We use a sensorimotor task to test the hypothesis that subjects are risk-sensitive. Subjects controlled a virtual ball undergoing Brownian motion towards a target. Subjects were required to minimize an explicit cost, in points, that was a combination of the final positional error of the ball and the integrated control cost. By testing subjects on different levels of Brownian motion noise and relative weighting of the position and control cost, we could distinguish between risk-sensitive and risk-neutral control. We show that subjects change their movement strategy pessimistically in the face of increased uncertainty in accord with the predictions of a risk-averse optimal controller. Our results suggest that risk-sensitivity is a fundamental attribute that needs to be incorporated into optimal feedback control models.

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.

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).

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.

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.

Acute sleep deprivation and circadian misalignment associated with transition onto the first night of work impairs visual selective attention.

Directory of Open Access Journals (Sweden)

Nayantara Santhi

2007-11-01

Full Text Available Overnight operations pose a challenge because our circadian biology promotes sleepiness and dissipates wakefulness at night. Since the circadian effect on cognitive functions magnifies with increasing sleep pressure, cognitive deficits associated with night work are likely to be most acute with extended wakefulness, such as during the transition from a day shift to night shift.To test this hypothesis we measured selective attention (with visual search, vigilance (with Psychomotor Vigilance Task [PVT] and alertness (with a visual analog scale in a shift work simulation protocol, which included four day shifts followed by three night shifts. There was a nocturnal decline in cognitive processes, some of which were most pronounced on the first night shift. The nighttime decrease in visual search sensitivity was most pronounced on the first night compared with subsequent nights (p = .04, and this was accompanied by a trend towards selective attention becoming 'fast and sloppy'. The nighttime increase in attentional lapses on the PVT was significantly greater on the first night compared to subsequent nights (p<.05 indicating an impaired ability to sustain focus. The nighttime decrease in subjective alertness was also greatest on the first night compared with subsequent nights (p<.05.These nocturnal deficits in attention and alertness offer some insight into why occupational errors, accidents, and injuries are pronounced during night work compared to day work. Examination of the nighttime vulnerabilities underlying the deployment of attention can be informative for the design of optimal work schedules and the implementation of effective countermeasures for performance deficits during night work.

Sexual selection on land snail shell ornamentation: a hypothesis that may explain shell diversity

Directory of Open Access Journals (Sweden)

Schilthuizen Menno

2003-06-01

Full Text Available Abstract Background Many groups of land snails show great interspecific diversity in shell ornamentation, which may include spines on the shell and flanges on the aperture. Such structures have been explained as camouflage or defence, but the possibility that they might be under sexual selection has not previously been explored. Presentation of the hypothesis The hypothesis that is presented consists of two parts. First, that shell ornamentation is the result of sexual selection. Second, that such sexual selection has caused the divergence in shell shape in different species. Testing the hypothesis The first part of the hypothesis may be tested by searching for sexual dimorphism in shell ornamentation in gonochoristic snails, by searching for increased variance in shell ornamentation relative to other shell traits, and by mate choice experiments using individuals with experimentally enhanced ornamentation. The second part of the hypothesis may be tested by comparing sister groups and correlating shell diversity with degree of polygamy. Implications of the hypothesis If the hypothesis were true, it would provide an explanation for the many cases of allopatric evolutionary radiation in snails, where shell diversity cannot be related to any niche differentiation or environmental differences.

Humans have evolved specialized skills of social cognition: the cultural intelligence hypothesis.

Science.gov (United States)

Herrmann, Esther; Call, Josep; Hernàndez-Lloreda, Maráa Victoria; Hare, Brian; Tomasello, Michael

2007-09-07

Humans have many cognitive skills not possessed by their nearest primate relatives. The cultural intelligence hypothesis argues that this is mainly due to a species-specific set of social-cognitive skills, emerging early in ontogeny, for participating and exchanging knowledge in cultural groups. We tested this hypothesis by giving a comprehensive battery of cognitive tests to large numbers of two of humans' closest primate relatives, chimpanzees and orangutans, as well as to 2.5-year-old human children before literacy and schooling. Supporting the cultural intelligence hypothesis and contradicting the hypothesis that humans simply have more "general intelligence," we found that the children and chimpanzees had very similar cognitive skills for dealing with the physical world but that the children had more sophisticated cognitive skills than either of the ape species for dealing with the social world.

Different meaning of the p-value in exploratory and confirmatory hypothesis testing

DEFF Research Database (Denmark)

Gerke, Oke; Høilund-Carlsen, Poul Flemming; Vach, Werner

2011-01-01

The outcome of clinical studies is often reduced to the statistical significance of results by indicating a p-value below the 5% significance level. Hypothesis testing and, through that, the p-value is commonly used, but their meaning is frequently misinterpreted in clinical research. The concept...... of hypothesis testing is explained and some pitfalls including those of multiple testing are given. The conceptual difference between exploratory and confirmatory hypothesis testing is discussed, and a better use of p-values, which includes presenting p-values with two or three decimals, is suggested....

The influence of variability on the optimal shape of an airway tree branching asymmetrically

International Nuclear Information System (INIS)

Mauroy, Benjamin; Bokov, Plamen

2010-01-01

The asymmetry of the bronchial tree has been reported on numerous occasions, and bronchi in the lung bifurcate most of the time into a major and a minor daughter. Asymmetry is most probably bound to play a role on the hydrodynamic resistance and volume occupation of the bronchial tree. Thus, in this work, we search for an optimal asymmetric airway tree crossed by Poiseuille flow that would be a good candidate to model the distal conductive part of the lung. The geometry is controlled by major and minor diameter reduction factors that depend on the generation. We show that the optimal asymmetric tree has diameter reduction factors that are adimensional from the second level of bifurcation and that they are highly dependent on the asymmetric ratio that defines the relative sizes of the major and minor branches in a bifurcation. This optimization also gives access to a cost function whose particularity is to be asymmetric around its minimum. Thus, the cliff-edge hypothesis predicts that if the system suffers variability, then the best tree is shifted from the optimal. We apply a recent theoretical model of cliff-edge in order to measure the role of variability on the determination of the best asymmetric tree. Then, we compare our results with lung data of the literature. In particular, we are able to quantify the variability needed to fit the data and to give hypothesis that could explain, at least partially, the shift found between the optimal tree and the measures in the case of asymmetric bronchial trees. Finally, our model predicts that, even if the population is adapted at best, there always exist individuals whose bronchial trees are associated with larger costs comparatively to the average and who ought to be more sensitive to geometrical remodeling

The Public Goods Hypothesis for the evolution of life on Earth.

Science.gov (United States)

McInerney, James O; Pisani, Davide; Bapteste, Eric; O'Connell, Mary J

2011-08-23

It is becoming increasingly difficult to reconcile the observed extent of horizontal gene transfers with the central metaphor of a great tree uniting all evolving entities on the planet. In this manuscript we describe the Public Goods Hypothesis and show that it is appropriate in order to describe biological evolution on the planet. According to this hypothesis, nucleotide sequences (genes, promoters, exons, etc.) are simply seen as goods, passed from organism to organism through both vertical and horizontal transfer. Public goods sequences are defined by having the properties of being largely non-excludable (no organism can be effectively prevented from accessing these sequences) and non-rival (while such a sequence is being used by one organism it is also available for use by another organism). The universal nature of genetic systems ensures that such non-excludable sequences exist and non-excludability explains why we see a myriad of genes in different combinations in sequenced genomes. There are three features of the public goods hypothesis. Firstly, segments of DNA are seen as public goods, available for all organisms to integrate into their genomes. Secondly, we expect the evolution of mechanisms for DNA sharing and of defense mechanisms against DNA intrusion in genomes. Thirdly, we expect that we do not see a global tree-like pattern. Instead, we expect local tree-like patterns to emerge from the combination of a commonage of genes and vertical inheritance of genomes by cell division. Indeed, while genes are theoretically public goods, in reality, some genes are excludable, particularly, though not only, when they have variant genetic codes or behave as coalition or club goods, available for all organisms of a coalition to integrate into their genomes, and non-rival within the club. We view the Tree of Life hypothesis as a regionalized instance of the Public Goods hypothesis, just like classical mechanics and euclidean geometry are seen as regionalized

The public goods hypothesis for the evolution of life on Earth

LENUS (Irish Health Repository)

McInerney, James O

2011-08-23

Abstract It is becoming increasingly difficult to reconcile the observed extent of horizontal gene transfers with the central metaphor of a great tree uniting all evolving entities on the planet. In this manuscript we describe the Public Goods Hypothesis and show that it is appropriate in order to describe biological evolution on the planet. According to this hypothesis, nucleotide sequences (genes, promoters, exons, etc.) are simply seen as goods, passed from organism to organism through both vertical and horizontal transfer. Public goods sequences are defined by having the properties of being largely non-excludable (no organism can be effectively prevented from accessing these sequences) and non-rival (while such a sequence is being used by one organism it is also available for use by another organism). The universal nature of genetic systems ensures that such non-excludable sequences exist and non-excludability explains why we see a myriad of genes in different combinations in sequenced genomes. There are three features of the public goods hypothesis. Firstly, segments of DNA are seen as public goods, available for all organisms to integrate into their genomes. Secondly, we expect the evolution of mechanisms for DNA sharing and of defense mechanisms against DNA intrusion in genomes. Thirdly, we expect that we do not see a global tree-like pattern. Instead, we expect local tree-like patterns to emerge from the combination of a commonage of genes and vertical inheritance of genomes by cell division. Indeed, while genes are theoretically public goods, in reality, some genes are excludable, particularly, though not only, when they have variant genetic codes or behave as coalition or club goods, available for all organisms of a coalition to integrate into their genomes, and non-rival within the club. We view the Tree of Life hypothesis as a regionalized instance of the Public Goods hypothesis, just like classical mechanics and euclidean geometry are seen as

Optimization of constellation jettisoning regards to short term collision risks

Science.gov (United States)

Handschuh, D.-DA.-A.; Bourgeois, E.

2018-04-01

The space debris problematic is directly linked to the in-orbit collision risk between artificial satellites. With the increase of the space constellation projects, a multiplication of multi-payload launches should occur. In the specific cases where many satellites are injected into orbit with the same launcher upper stage, all these objects will be placed on similar orbits, very close one from each other, at a specific moment where their control capabilities will be very limited. Under this hypothesis, it is up to the launcher operator to ensure that the simultaneous in-orbit injection is safe enough to guarantee the non-collision risk between all the objects under a ballistic hypothesis eventually considering appropriate uncertainties. The purpose of the present study is to find optimized safe separation conditions to limit the in-orbit collision risk following the injection of many objects on very close orbits in a short-delay mission.

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.

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…

Empathy and universal values explicated by the empathy-altruism hypothesis.

Science.gov (United States)

Persson, Björn N; Kajonius, Petri J

2016-01-01

Research reports that empathy is on the decline in present-day society, together with an increasing trend in self-enhancing values. Based on the empathy-altruism hypothesis, we investigated whether these constructs are interlinked by analyzing the relationships between emotional and cognitive empathy and 10 universal values. In the first study, using a middle-aged U.S. sample, the results showed that empathy was strongly and positively related to altruistic values and negatively to self-enhancing values in a pattern that aligned with the empathy-altruism hypothesis. In a second confirmation study, these findings were replicated and extended, while also controlling for the Big Five personality traits, to discount that empathy is only captured by basic personality. Only emotional empathy, not cognitive empathy, accounted for up to 18% additional variance in altruistic values, which further confirmed the emphasis on feelings, as postulated by the empathy-altruism hypothesis.

Linking mind wandering tendency to risky driving in young male drivers.

Science.gov (United States)

Albert, Derek A; Ouimet, Marie Claude; Jarret, Julien; Cloutier, Marie-Soleil; Paquette, Martin; Badeau, Nancy; Brown, Thomas G

2018-02-01

Risky driving is a significant contributor to road traffic crashes, especially in young drivers. Transient mind wandering states, an internal form of distraction, are associated with faster driving, reduced headway distance, slower response times, reduced driver vigilance, and increased crash risk. It is unclear whether a trait tendency to mind wander predicts risky driving, however. Mind wandering is also associated with poor executive control, but whether this capacity moderates the putative link between mind wandering tendency and risky driving is uncertain. The present study tested whether mind wandering tendency predicts risky driving behaviour in young male drivers aged 18-21 (N=30) and whether this relationship is mediated by driver vigilance and moderated by executive control capacity. Mind wandering was measured with the Sustained Attention to Response Task (SART) and the Daydreaming Frequency Scale (DDFS). Risky driving was assessed by mean speed in a driving simulator and driver vigilance was quantified by horizontal eye movements measured with eye tracking. Results showed that greater mind wandering tendency based on SART performance significantly predicts faster mean speed, confirming the main hypothesis. Neither driver vigilance mediated nor executive control capacity moderated this relationship as hypothesized. These findings speak to the complexity of individual differences in mind wandering. Overall, mind wandering tendency is a significant marker of risky driving in young drivers, which could guide the development of targeted interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

The Variability Hypothesis: The History of a Biological Model of Sex Differences in Intelligence.

Science.gov (United States)

Shields, Stephanie A.

1982-01-01

Describes the origin and development of the variability hypothesis as applied to the study of social and psychological sex differences. Explores changes in the hypothesis over time, social and scientific factors that fostered its acceptance, and possible parallels between the variability hypothesis and contemporary theories of sex differences.…

Is optimality in stomatal conductance an endogenous process or an emergent property arising from interactions with the environment?

Science.gov (United States)

Resco de Dios, Victor; Gessler, Arthur; Ferrio, Juan Pedro; Bahn, Michael; Milcu, Alexandru; Tissue, David; Voltas, Jordi; Roy, Jacques

2016-04-01

Plants are sessile and poikilothermic organisms that need to respond and adjust promptly to an ever-changing environment. Over a single 24 h period, a plant may experience the same level of variation in radiation as in its entire life-time and, in some climates, the oscillation in day-night temperature and vapor pressure deficit might be of similar magnitude to that experienced across a full year. Plants need to maintain a positive C balance without depleting soil water reserves in the face of such a diverse environment, and feedbacks between assimilation (A) and water losses (E) are thought to have evolved to optimize stomatal conductance (gs). In short, the optimal conductance hypothesis proposes that cross-talks between A and stomatal conductance gs lead to a constant marginal water use (λ) during a day, such that A is maximized and E minimized. The biological mechanism by which biochemical processes would feedback gs remains unknown, but multiple studies have shown empirical support for this hypothesis, leading to its current consideration of theory by many. Here we test whether optimal stomatal conductance is an endogenous property, that is, driven solely by factors internal to the plant, and in the absence of environmental fluctuations. After 5 days of entrainment, where monoculture canopies of bean and of cotton were subjected to the average environmental conditions of an August sunny day in Montpellier (at the CNRS European Ecotron, FR), we kept temperature, relative humidity and photosynthetically active radiation constant for 48 h at the values observed at noon. During this period, we monitored leaf gas exchange continuously every two minutes, and canopy gas exchange every 15 minutes. We observed a periodic oscillation in λ, showing a 24 h period, and consistent with a circadian regulation of water use efficiency. Hourly variations in λ could thus not be explained by the optimal stomatal hypothesis. Moreover, the pattern of variation (of maximal water

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.

The estrogen hypothesis of schizophrenia implicates glucose metabolism

DEFF Research Database (Denmark)

Olsen, Line; Hansen, Thomas; Jakobsen, Klaus D

2008-01-01

expression studies have indicated an equally large set of candidate genes that only partially overlap linkage genes. A thorough assessment, beyond the resolution of current GWA studies, of the disease risk conferred by the numerous schizophrenia candidate genes is a daunting and presently not feasible task....... We undertook these challenges by using an established clinical paradigm, the estrogen hypothesis of schizophrenia, as the criterion to select candidates among the numerous genes experimentally implicated in schizophrenia. Bioinformatic tools were used to build and priorities the signaling networks...... implicated by the candidate genes resulting from the estrogen selection. We identified ten candidate genes using this approach that are all active in glucose metabolism and particularly in the glycolysis. Thus, we tested the hypothesis that variants of the glycolytic genes are associated with schizophrenia...