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Sample records for luminance controlled pupil

  1. Luminance controlled pupil size affects Landolt C task performance

    SciTech Connect

    Berman, S.M. ); Fein, G. ); Jewett, D.L.; Ashford, F. )

    1993-02-01

    Subjects judged the orientation of a 2 min. gap Landolt C located at a distance of 2.4 m. The stimuli were presented in central vision on a CRT, at low to medium contrast. The effects of varying the spectrum and luminance of surround lighting were assessed on both pupil size (measured using infrared pupillometry during task performance) and task accuracy. The task display was protected from the surround lighting, so that its luminance and contrast could be varied independently of the changes in the surround lighting. Indirect surround illumination was provided by either two illuminants of very different scotopic spectral content but with the same photopic luminance (Experiments 1 and 3), or by using the same illuminant at two different luminance levels (Experiment 2). In Experiment 3, the effect of changing surround spectrum was compared to the effect of varying task background luminance between 12 cd/m[sup 2] and 73 cd/m[sup 2]. In all experiments, scotopically enhanced surround lighting produced pupil areas which were reduced by almost 50% in comparison with surround lighting with relatively less scotopic luminance. Concomitantly there was improvement in Landolt C task performance with the scotopically enhanced surround lighting at all contrast and luminance levels. In these experiments, smaller pupil sizes were associated with significantly better visual-task performance in spite of lower task retinal illuminance when compared to the condition with larger pupils. These results suggest that changes in surround spectrum can compensate for the effect on task performance of a reduction in task luminance and supports the hypothesis that lighting energy savings could accrue in the workplace by shifting lamp spectra to obtain greater scotopic efficacy.

  2. Luminance controlled pupil size affects Landolt C task performance. Revision

    SciTech Connect

    Berman, S.M.; Fein, G.; Jewett, D.L.; Ashford, F.

    1993-02-01

    Subjects judged the orientation of a 2 min. gap Landolt C located at a distance of 2.4 m. The stimuli were presented in central vision on a CRT, at low to medium contrast. The effects of varying the spectrum and luminance of surround lighting were assessed on both pupil size (measured using infrared pupillometry during task performance) and task accuracy. The task display was protected from the surround lighting, so that its luminance and contrast could be varied independently of the changes in the surround lighting. Indirect surround illumination was provided by either two illuminants of very different scotopic spectral content but with the same photopic luminance (Experiments 1 and 3), or by using the same illuminant at two different luminance levels (Experiment 2). In Experiment 3, the effect of changing surround spectrum was compared to the effect of varying task background luminance between 12 cd/m{sup 2} and 73 cd/m{sup 2}. In all experiments, scotopically enhanced surround lighting produced pupil areas which were reduced by almost 50% in comparison with surround lighting with relatively less scotopic luminance. Concomitantly there was improvement in Landolt C task performance with the scotopically enhanced surround lighting at all contrast and luminance levels. In these experiments, smaller pupil sizes were associated with significantly better visual-task performance in spite of lower task retinal illuminance when compared to the condition with larger pupils. These results suggest that changes in surround spectrum can compensate for the effect on task performance of a reduction in task luminance and supports the hypothesis that lighting energy savings could accrue in the workplace by shifting lamp spectra to obtain greater scotopic efficacy.

  3. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response.

    PubMed

    Barrionuevo, Pablo A; Cao, Dingcai

    2016-09-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a "winner-takes-all" process, suggesting the integration with PC signals might be mediated by a postretinal site.

  4. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response

    PubMed Central

    Barrionuevo, Pablo A.; Cao, Dingcai

    2016-01-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a “winner-takes-all” process, suggesting the integration with PC signals might be mediated by a postretinal site. PMID:27690169

  5. Personality and Pupil Control Behavior.

    ERIC Educational Resources Information Center

    Helsel, A. Ray

    Pupil control behavior is conceptualized as a continuum ranging from custodialism, which views students as irresponsible and undisciplined and needing strictness and punishment, to humanism, which emphasizes a democratic atmosphere in which students are capable of self-discipline and are treated accordingly. The theoretical framework for this…

  6. Relationships among Teacher Personality, Pupil Control Attidues, and Pupil Control Behavior.

    ERIC Educational Resources Information Center

    Bush, Doris W.

    This research examined the relationships among three variables--teacher personality, teacher pupil control attitudes, and teacher pupil control behavior--to determine whether teacher personality or pupil control attitudes were the better predictor of pupil control behavior. Subjects were 102 junior high school teachers. The major finding of the…

  7. Pupil Diameter May Reflect Motor Control and Learning.

    PubMed

    White, Olivier; French, Robert M

    2017-01-01

    Non-luminance-mediated changes in pupil diameter have been used since the first studies by Darwin in 1872 as indicators of clinical, cognitive, and arousal states. However, the relation between processes involved in motor control and changes in pupil diameter remains largely unknown. Twenty participants attempted to compensate random walks of a cursor with a computer mouse to restrain its trajectory within a target circle while the authors recorded their pupil diameters. Two conditions allowed the authors to experimentally manipulate the motor and cognitive components of the task. First, the step size of the cursor's random walk was either large or small leading to 2 task difficulties (difficult or easy). Second, they instructed participants to imagine controlling the cursor by moving the mouse, but without actually moving it (task modality: imagined movement or real movement condition). Task difficulty and modality allowed the authors to show that pupil diameters reflect processes involved in motor control and in the processing of feedback, respectively. Furthermore, the authors also demonstrate that motor learning can be quantified by pupil size. This noninvasive approach provides a promising method for investigating not only motor control, but also motor imagery, a research field of growing importance in sports and rehabilitation.

  8. Pupil Control in the School Climate.

    ERIC Educational Resources Information Center

    Schmidt, Linda J.; Jacobson, Michael H.

    Pupil control (discipline) takes on different forms in different schools, and among different teachers in the same school. Pupil control has been described as existing along a continuum from humanistic to custodial. The prototype of the custodial orientation is the school that provides a rigid and highly controlled setting concerned primarily with…

  9. Principals' Pupil Control Behavior and School Robustness.

    ERIC Educational Resources Information Center

    Smedley, Stanley R.; Willower, Donald J.

    1981-01-01

    A survey of 3,100 students, teachers, and principals in 47 elementary and secondary schools in the Middle Atlantic region, using the Pupil Control Behavior Form, revealed a positive association between principals' humanistic pupil control behavior and schools'"robustness" (the degree of meaning and excitement students find in school).…

  10. Organizational Pressure, Personal Ideology and Teacher Pupil Control Behaviour.

    ERIC Educational Resources Information Center

    Blust, Ross S.; Willower, Donald J.

    1979-01-01

    It was found that teachers' own views on pupil control predicted their pupil control behavior, while organizational pressures, represented by teacher perceptions of the pupil control views of colleagues and the principal, failed to do so. (Author/IRT)

  11. Toward Definition and Measurement of Pupil Control Behaviour

    ERIC Educational Resources Information Center

    Helsel, A. Ray; Willower, Donald J.

    1974-01-01

    Pupil control is regarded as an integrative theme to explain the collection of extensive observations made in schools. This report attempts to define and measure pupil control behavior, a companion concept to pupil control ideology. (Author/WM)

  12. Pupil Control Ideology in Predicting Teacher Discipline Referrals.

    ERIC Educational Resources Information Center

    Foley, Walter J.; Brooks, Robert

    1978-01-01

    Concludes that humanism in teachers is related to reporting fewer unresolvable conflicts with pupils and that pupil control ideology and subsequent teacher control behavior (the referring of pupils to the administration for disciplinary action) are related. (Author/IRT)

  13. Pupil tracking optical coherence tomography for precise control of pupil entry position

    PubMed Central

    Carrasco-Zevallos, Oscar; Nankivil, Derek; Keller, Brenton; Viehland, Christian; Lujan, Brandon J.; Izatt, Joseph A.

    2015-01-01

    To maximize the collection efficiency of back-scattered light, and to minimize aberrations and vignetting, the lateral position of the scan pivot of an optical coherence tomography (OCT) retinal scanner should be imaged to the center of the ocular pupil. Additionally, several retinal structures including Henle’s Fiber Layer (HFL) exhibit reflectivities that depend on illumination angle, which can be controlled by varying the pupil entry position of the OCT beam. In this work, we describe an automated method for controlling the lateral pupil entry position in retinal OCT by utilizing pupil tracking in conjunction with a 2D fast steering mirror placed conjugate to the retinal plane. We demonstrate that pupil tracking prevents lateral motion artifacts from impeding desired pupil entry locations, and enables precise pupil entry positioning and therefore control of the illumination angle of incidence at the retinal plane. We use our prototype pupil tracking OCT system to directly visualize the obliquely oriented HFL. PMID:26417510

  14. Pupil tracking optical coherence tomography for precise control of pupil entry position.

    PubMed

    Carrasco-Zevallos, Oscar; Nankivil, Derek; Keller, Brenton; Viehland, Christian; Lujan, Brandon J; Izatt, Joseph A

    2015-09-01

    To maximize the collection efficiency of back-scattered light, and to minimize aberrations and vignetting, the lateral position of the scan pivot of an optical coherence tomography (OCT) retinal scanner should be imaged to the center of the ocular pupil. Additionally, several retinal structures including Henle's Fiber Layer (HFL) exhibit reflectivities that depend on illumination angle, which can be controlled by varying the pupil entry position of the OCT beam. In this work, we describe an automated method for controlling the lateral pupil entry position in retinal OCT by utilizing pupil tracking in conjunction with a 2D fast steering mirror placed conjugate to the retinal plane. We demonstrate that pupil tracking prevents lateral motion artifacts from impeding desired pupil entry locations, and enables precise pupil entry positioning and therefore control of the illumination angle of incidence at the retinal plane. We use our prototype pupil tracking OCT system to directly visualize the obliquely oriented HFL.

  15. Toward Definition and Measurement of Pupil Control Behavior.

    ERIC Educational Resources Information Center

    Helsel, A. Ray; Willower, Donald J.

    An attempt is made to define and measure pupil control "behavior." In order to measure pupil control behavior, an instrument called the Pupil Control Behavior (PCB) Form was developed and tested. The 31 custodial and 34 humanistic items were randomized, and the initial version of the PCB Form was administered in 20 schools in Illinois…

  16. Teacher Pupil Control Ideology--Behavior Congruence and Job Satisfaction.

    ERIC Educational Resources Information Center

    Willower, Donald J.; Heckert, J. Wayne

    The hypothesis that teacher pupil control ideology-behavior congruence would be positively related to teacher job satisfaction was tested. The rationale for the hypothesis was that teachers whose beliefs and behaviors concerning pupil control were consistent would be likely to be contented with their work. Pupil control was seen as a central…

  17. Some Comments on Inquiries on Schools and Pupil Control.

    ERIC Educational Resources Information Center

    Willower, Donald J.

    This speech, by the co-author of a bibliography of studies of pupil control, reviews literature on that subject, differentiating between studies on Pupil Control Ideology (PCI) and Pupil Control Behavior (PCB), describing instances of their interrelationship, and weighing the various merits of PCI and PCB instruments. The author concludes that…

  18. Pupils

    ERIC Educational Resources Information Center

    Garber, Lee O.; Seitz, Reynolds C.

    1971-01-01

    Discusses recent court litigation concerning legal rights and responsibilities of pupils covering procedural due process, grooming and appearance, regulation of speech and publications, liability for pupil injuries, and racial integration. (JF)

  19. Pupil Control Ideology, Pupil Control Behavior and the Quality of School Life.

    ERIC Educational Resources Information Center

    Lunenburg, Fred C.; Schmidt, Linda J.

    1989-01-01

    This article defines two approaches to pupil control--custodial and humanistic--and reports results of an investigation of the relationship between teacher control ideology and behavior and their influence on quality of life for students. Subjects were 239 elementary and secondary teachers and their students from 5 school districts. (IAH)

  20. Teachers' Conceptualization of Pupil Control in Elementary School Physical Education.

    ERIC Educational Resources Information Center

    Henkel, Steven A.

    1991-01-01

    Describes a framework of techniques teachers used to manage elementary physical education students and foster pupil self-control. Audiotapes and interviews resulted in development of the Physical Education Pupil Control Inventory. Facilitating self-control involved selecting tutorial control techniques, using indirect technique forms, and…

  1. STP---The Teacher's Edge to Pupil Control.

    ERIC Educational Resources Information Center

    Henkel, Steven

    1989-01-01

    Results of a study of pupil control techniques employed by elementary physical educators are reported. Three classifications of control techniques emerged. A Physical Education Pupil Control Inventory (PEPCI) was designed based on findings. Also discussed are rationale and methods of utilizing PEPCI in inservice and preservice training of physical…

  2. Pupil Control Ideology and Teacher Influence in the Classroom.

    ERIC Educational Resources Information Center

    Goldenberg, Ronald

    A study investigated whether pupil control ideology of teachers differentially affected their operational behavior in the classroom. Elementary school teachers employed in a suburban St. Louis district (N=260) responded to the Pupil Control Ideology Form (PCI). From this group 20 were selected to comprise two experimental groups: those with…

  3. Pupil Control Ideology among Prospective South African and Indian Teachers

    ERIC Educational Resources Information Center

    Cherian, L.

    2011-01-01

    The purpose of teacher training programmes is to instil a humanistic ideology into the school curriculum. Unfortunately however, this is not always able to change the culture of a school. The Pupil Control Ideology (PCI) scale was designed to measure the pupil control orientation of the respondents (teachers) on a humanistic-custodial continuum.…

  4. Pupil Control Ideology among Prospective South African and Indian Teachers

    ERIC Educational Resources Information Center

    Cherian, L.

    2011-01-01

    The purpose of teacher training programmes is to instil a humanistic ideology into the school curriculum. Unfortunately however, this is not always able to change the culture of a school. The Pupil Control Ideology (PCI) scale was designed to measure the pupil control orientation of the respondents (teachers) on a humanistic-custodial continuum.…

  5. Pupils.

    ERIC Educational Resources Information Center

    Lufler, Henry S., Jr.; Bielsky, Donald J.

    Litigation having to do with pupils occurred with greater frequency in 1980 than in the past. The greatest increase dealt with the handicapped and with substantive rights of students. Cases involving handicapped students generally focused on parent requests for residential treatment, extended-year programs, and in-class assistance for their…

  6. Pupil Control Ideology: Comparative Perspectives--United States and Canada.

    ERIC Educational Resources Information Center

    Hamalian, A.

    1979-01-01

    This study explores the relationship between the Pupil Control Ideology Scale (PCI) and the sex of the teacher, level of teaching (preschool, elementary, secondary), as well as level of school bureaucracy based on the Moeller scale. (Author/RTS)

  7. The pupil can control an artificial lens intuitively.

    PubMed

    Fliedner, Jan; Heine, Christian; Bretthauer, Georg; Wilhelm, Helmut

    2014-02-04

    After cataract surgery, the ability to accommodate is lost. For this reason, a mechatronic IOL is being developed at the moment: The Artificial Accommodation System. This device requires an easily measureable indicator of the distance of the observed object to determine the demand of accommodation. As the pupil constricts with near vision, pupil size might be such an indicator. Our research focused on whether the pupil can control an artificial lens. A study with 14 healthy subjects aged between 24 and 64 years was conducted. An artificial lens with variable refractive power was mounted in front of one eye. In this eye, natural accommodation was greatly reduced or absent due to presbyopia, pseudophakia, or iatrogenic cycloplegia. The lens' refractive power was changed in a computer-controlled manner depending on changes in the pupil diameter of the second eye, which could not see the fixation stimulus. The subject's task was to get a clear focused image of the target in different distances. The lens can be controlled by the pupil intuitively (P < 1.8 × 10(-18)). Without prior knowledge, 11/14 subjects passed the first trial, and 31/41 trials were successful. Only one subject was not able to control the lens at all. Most subjects comprehended instantly how to use the unfamiliar lens control to bring a target into focus. This study emphasizes the plasticity of the visual control system. Positioning accuracy was acceptable, but the control must be optimized to facilitate maintaining a defined refractive power.

  8. Pupil Control Behavior, Classroom Robustness, and Self-Control: Public and Military High Schools Compared.

    ERIC Educational Resources Information Center

    Sartori, Mary Ann; Bauske, Terri; Lunenburg, Fred C.

    This study investigates students' perceptions of teachers' pupil control behavior, classroom robustness, and student self-control. Results reveal an association between humanistic pupil control behavior of teachers and high levels of classroom robustness, high levels of classroom robustness and high student self-control, and teacher humanism in…

  9. The Relationship between Pupil Control Ideology and Academic Optimism

    ERIC Educational Resources Information Center

    Gilbert, Michael J.

    2012-01-01

    This study investigates the relationship between pupil control ideology and academic optimism. Information was generated through responses to a questionnaire emailed to teachers in two school districts in Central New Jersey. The districts were categorized GH, as determined by the State's district factor grouping. The research concludes that there…

  10. School Socioeconomic Status and Teacher Pupil Control Behavior

    ERIC Educational Resources Information Center

    Brown, Lorraine Hayes; And Others

    1974-01-01

    Despite contrary evidence in the literature, this experimental investigation found that race and the interaction of race and socioeconomic status of students do not have a significant effect on teacher "pupil control behavior." Alternative explanations for these findings are discussed. (EH)

  11. Pupil Control Behavior, Student Brinkmanship and Environmental Robustness.

    ERIC Educational Resources Information Center

    Brown, Ralph E.; Licata, Joseph W.

    1978-01-01

    From the perspective of the student audience, the general results of the study suggest that, as teacher custodialism increases, the more robust are acts of student brinksmanship, the less robust is the teacher's pupil control behavior, and the less the teacher is liked by students. (Author)

  12. School Democratic Meetings: Pupil Control Discourse in Disguise

    ERIC Educational Resources Information Center

    Thornberg, Robert

    2010-01-01

    The aim of this qualitative case study is to investigate how learning in "democratic participation" is constituted by the social interaction and conversation pattern in school democratic meetings in a Swedish primary school. According to the findings, a pupil control discourse and the Initiation-Response-Evaluation pattern dominates the…

  13. The Relationship between Pupil Control Ideology and Academic Optimism

    ERIC Educational Resources Information Center

    Gilbert, Michael J.

    2012-01-01

    This study investigates the relationship between pupil control ideology and academic optimism. Information was generated through responses to a questionnaire emailed to teachers in two school districts in Central New Jersey. The districts were categorized GH, as determined by the State's district factor grouping. The research concludes that there…

  14. Pupil Control Ideology and Behavior as Predictors of Environmental Robustness: Public and Private Schools Compared.

    ERIC Educational Resources Information Center

    Lunenburg, Fred C.

    1991-01-01

    Questionnaires examined differences between public and private schools regarding teachers' pupil control ideology and behavior. Teachers and students completed three survey instruments. Only pupil control ideology differed significantly between public and private schools. Pupil control behavior was the best predictor of environmental robustness.…

  15. Pupil Control Ideology as a Source of Stress: The Student Teacher's Dilemma.

    ERIC Educational Resources Information Center

    Jones, Dan R.

    One type of adaptation made by each student teacher is the development of attitudes toward controlling pupils. The student teachers' attitudes toward pupil control may be at odds with those of other educators and this difference in attitude, particularly in the case of the cooperating teacher, can cause stress. Attitudes toward pupil control can…

  16. Dynamic pupillary response controlled by the pupil size effect.

    PubMed

    Sun, F; Tauchi, P; Stark, L

    1983-11-01

    Pupillary escape has been described as an initial contraction followed by a slow redilatation, occurring in response to a step stimulus of low-intensity light. When the initial pupil size is small, the response to the same step stimulus is pupillary capture, a steady and sustained contraction. In this experiment a comparison was made between three modes of controlling pupil size and thereby of regulating the pupillary response: contralateral light background level, ipsilateral light background level, and accommodative level with which there is no change in retinal adaptation. All three level setting modes showed similar results in illustrating the pupil size effect. In addition, an inhibitory effect was found with both ipsilateral and contralateral light backgrounds that is independent of Weber's Law in the contralateral case. Our results lead to the formulation of a binocular model, featuring an internal parameter control whereby a signal dependent on the static pupil size regulates the gains of the parallel phasic and tonic pathways, the former responsive to transient changes of light, and the latter to background levels of light and accommodative levels. Our findings also raise interesting questions concerning the loci of these complex interactions in the simple neuroanatomy of the pupillary pathways.

  17. Cognitive effort and pupil dilation in controlled and automatic processes.

    PubMed

    Querino, Emanuel; Dos Santos, Lafaiete; Ginani, Giuliano; Nicolau, Eduardo; Miranda, Débora; Romano-Silva, Marco; Malloy-Diniz, Leandro

    2015-01-01

    The Five Digits Test (FDT) is a Stroop paradigm test that aims to evaluate executive functions. It is composed of four parts, two of which are related to automatic and two of which are related to controlled processes. It is known that pupillary diameter increases as the task's cognitive demand increases. In the present study, we evaluated whether the pupillary diameter could distinguish cognitive effort between automated and controlled cognitive processing during the FDT as the task progressed. As a control task, we used a simple reading paradigm with a similar visual aspect as the FDT. We then divided each of the four parts into two blocks in order to evaluate the differences between the first and second half of the task. Results indicated that, compared to a control task, the FDT required higher cognitive effort for each consecutive part. Moreover, the first half of every part of the FDT induced dilation more than the second. The differences in pupil dilation during the first half of the four FDT parts were statistically significant between the parts 2 and 4 (p=0.023), and between the parts 3 and 4 (p=0.006). These results provide further evidence that cognitive effort and pupil diameter can distinguish controlled from automatic processes.

  18. Cognitive effort and pupil dilation in controlled and automatic processes

    PubMed Central

    Querino, Emanuel; dos Santos, Lafaiete; Ginani, Giuliano; Nicolau, Eduardo; Miranda, Débora; Romano-Silva, Marco; Malloy-Diniz, Leandro

    2015-01-01

    The Five Digits Test (FDT) is a Stroop paradigm test that aims to evaluate executive functions. It is composed of four parts, two of which are related to automatic and two of which are related to controlled processes. It is known that pupillary diameter increases as the task’s cognitive demand increases. In the present study, we evaluated whether the pupillary diameter could distinguish cognitive effort between automated and controlled cognitive processing during the FDT as the task progressed. As a control task, we used a simple reading paradigm with a similar visual aspect as the FDT. We then divided each of the four parts into two blocks in order to evaluate the differences between the first and second half of the task. Results indicated that, compared to a control task, the FDT required higher cognitive effort for each consecutive part. Moreover, the first half of every part of the FDT induced dilation more than the second. The differences in pupil dilation during the first half of the four FDT parts were statistically significant between the parts 2 and 4 (p=0.023), and between the parts 3 and 4 (p=0.006). These results provide further evidence that cognitive effort and pupil diameter can distinguish controlled from automatic processes. PMID:28123801

  19. Assessing Visual Delays using Pupil Oscillations

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    2012-01-01

    Stark (1962) demonstrated vigorous pupil oscillations by illuminating the retina with a beam of light focussed to a small spot near the edge of the pupil. Small constrictions of the pupil then are sufficient to completely block the beam, amplifying the normal relationship between pupil area and retinal illuminance. In addition to this simple and elegant method, Stark also investigated more complex feedback systems using an electronic "clamping box" which provided arbitrary gain and phase delay between a measurement of pupil area and an electronically controlled light source. We have replicated Stark's results using a video-based pupillometer to control the luminance of a display monitor. Pupil oscillations were induced by imposing a linear relationship between pupil area and display luminance, with a variable delay. Slopes of the period-vs-delay function for 3 subjects are close to the predicted value of 2 (1.96-2.39), and the implied delays range from 254 to 376 508 to 652 milliseconds. Our setup allows us to extend Stark's work by investigating a broader class of stimuli.

  20. Teacher Pupil-Control Ideology and Behavior and Classroom Environmental Robustness.

    ERIC Educational Resources Information Center

    Multhauf, Arleen P.; And Others

    1978-01-01

    Examines teacher's beliefs and behavior regarding pupil control and their impact on fourth, fifth, and sixth grade students' perceptions of classroom life. Research indicates that humanistic teacher pupil-control behavior is associated with students' reports of high classroom robustness. Inconsistencies between male ideology and behavior are…

  1. Pupil Control Ideology and Behavior and the Quality of School Life.

    ERIC Educational Resources Information Center

    Lunenburg, Frederick C.; Schmidt, Linda J.

    More information is needed about the quality of school life, especially as it affects students' attitudes toward school. This paper contrasts pupil control ideologies and the types of school climates they engender in order to determine their effects on the quality of school life. Pupil control ideology and teacher behavior are conceptualized along…

  2. A Study of Pupil Control Ideology: A Person-Oriented Approach to Data Analysis

    ERIC Educational Resources Information Center

    Adwere-Boamah, Joseph

    2010-01-01

    Responses of urban school teachers to the Pupil Control Ideology questionnaire were studied using Latent Class Analysis. The results of the analysis suggest that the best fitting model to the data is a two-cluster solution. In particular, the pupil control ideology of the sample delineates into two clusters of teachers, those with humanistic and…

  3. Teacher Pupil-Control Ideology and Behavior as Predictors of Classroom Environment: Public and Catholic Schools Compared. Draft.

    ERIC Educational Resources Information Center

    Lunenburg, Fred C.

    This study examined differences between public and Catholic schools concerning teachers' pupil control ideology, teachers' pupil control behavior, and students' perceptions of their classroom environments. The concepts of humanistic and custodial pupil control ideologies were used to contrast types of individual orientations and the types of…

  4. Pupil Control Behavior, Classroom Robustness, and Self-Control: Public and Military Secondary Schools.

    ERIC Educational Resources Information Center

    Sartori, Mary Ann; Bauske, Terri; Lunenburg, Fred C.

    2000-01-01

    Investigated students' perceptions of teachers pupil-control behavior, classroom robustness, and student self-control, highlighting possible differences between public and military secondary schools. Humanistic approaches had more positive, interrelated effects among these variables. Military (custodial) classrooms were perceived as less robust,…

  5. Pupil Control Behavior, Classroom Robustness, and Self-Control: Public and Military Secondary Schools.

    ERIC Educational Resources Information Center

    Sartori, Mary Ann; Bauske, Terri; Lunenburg, Fred C.

    2000-01-01

    Investigated students' perceptions of teachers pupil-control behavior, classroom robustness, and student self-control, highlighting possible differences between public and military secondary schools. Humanistic approaches had more positive, interrelated effects among these variables. Military (custodial) classrooms were perceived as less robust,…

  6. Students' Perceptions of Ideal and Actual Teacher Pupil Control Behavior and Reading Achievement.

    ERIC Educational Resources Information Center

    Forlenza, Vito A.; Willower, Donald J.

    1980-01-01

    Tests the hypothesis that student reading achievement will be a function of the congruence of student's perception of actual and ideal teacher pupil-control behavior. Subjects were 231 students in nine sixth-grade classrooms. (MP)

  7. Pupils' Self-Perceptions: The Role of Teachers' Judgment Controlling for Big-Fish-Little-Pond Effect

    ERIC Educational Resources Information Center

    Bressoux, Pascal; Pansu, Pascal

    2016-01-01

    This article aims to study the relationship between teachers' judgment and pupils' self-perceptions controlling for the big-fish-little-pond effect (BFLPE). Three studies were conducted among third-grade pupils. Study 1 (n = 585) focused on pupils' perceptions of their scholastic competence. Teachers' judgment and BFLPE were found to have an…

  8. Pupils' Self-Perceptions: The Role of Teachers' Judgment Controlling for Big-Fish-Little-Pond Effect

    ERIC Educational Resources Information Center

    Bressoux, Pascal; Pansu, Pascal

    2016-01-01

    This article aims to study the relationship between teachers' judgment and pupils' self-perceptions controlling for the big-fish-little-pond effect (BFLPE). Three studies were conducted among third-grade pupils. Study 1 (n = 585) focused on pupils' perceptions of their scholastic competence. Teachers' judgment and BFLPE were found to have an…

  9. Histone Demethylase KDM6A Controls the Mammary Luminal Lineage through Enzyme-Independent Mechanisms

    PubMed Central

    Yoo, Kyung Hyun; Oh, Sumin; Kang, Keunsoo; Wang, Chaochen; Robinson, Gertraud W.; Ge, Kai

    2016-01-01

    Establishment of the mammary luminal cell lineage is controlled primarily by hormones and through specific transcription factors (TFs). Previous studies have linked histone methyltransferases to the differentiation of mammary epithelium, thus opening the possibility of biological significance of counteracting demethylases. We have now demonstrated an essential role for the H3K27me3 demethylase KDM6A in generating a balanced alveolar compartment. Deletion of Kdm6a in the mammary luminal cell lineage led to a paucity of luminal cells and an excessive expansion of basal cells, both in vivo and in vitro. The inability to form structurally normal ducts and alveoli during pregnancy resulted in lactation failure. Mutant luminal cells did not exhibit their distinctive transcription factor pattern and displayed basal characteristics. The genomic H3K27me3 landscape was unaltered in mutant tissue, and support for a demethylase-independent mechanism came from mice expressing a catalytically inactive KDM6A. Mammary tissue developed normally in these mice. Chromatin immunoprecipitation sequencing (ChIP-seq) experiments demonstrated KDM6A binding to putative enhancers enriched for key mammary TFs and H3K27ac. This study demonstrated for the first time that the mammary luminal lineage relies on KDM6A to ensure a transcription program leading to differentiated alveoli. Failure to fully implement this program results in structurally and functionally impaired mammary tissue. PMID:27215382

  10. Binocular adaptive optics vision analyzer with full control over the complex pupil functions.

    PubMed

    Schwarz, Christina; Prieto, Pedro M; Fernández, Enrique J; Artal, Pablo

    2011-12-15

    We present a binocular adaptive optics vision analyzer fully capable of controlling both amplitude and phase of the two complex pupil functions in each eye of the subject. A special feature of the instrument is its comparatively simple setup. A single reflective liquid crystal on silicon spatial light modulator working in pure phase modulation generates the phase profiles for both pupils simultaneously. In addition, another liquid crystal spatial light modulator working in transmission operates in pure intensity modulation to produce a large variety of pupil masks for each eye. Subjects perform visual tasks through any predefined variations of the complex pupil function for both eyes. As an example of the system efficiency, we recorded images of the stimuli through the system as they were projected at the subject's retina. This instrument proves to be extremely versatile for designing and testing novel ophthalmic elements and simulating visual outcomes, as well as for further research of binocular vision.

  11. Active optics concept for hypertelescope aberration control and pupil densification

    NASA Astrophysics Data System (ADS)

    Dohlen, Kjetil; Dargent, Pascal; Ferrari, Marc; Lemaitre, Gerard R.

    2003-02-01

    One of the instrumental concepts under study for large baseline interferometers for high resolution astronomical imaging, in particular applied to exoplanet search and characterisation, is the hypertelescope (HT). Mainly considered for space deployment, this sparse array of mirror segments supported either by a struss structure or by free-flying micro satellites form a giant, diluted primary mirror. The focal plane instrumentation, including pupil densification optics, is located in the primary focus instrument space craft (ISC). Baselines considered for first-generation HTs are of the order of 100 m, but one can envisage kilometric arrays capable of unprecedented angular resolution. Pointing with such a telescope poses orbital navigation problems. Letting the entire array perform a slow sky-scanning motion and navigating the ISC within the primary focal plane in order to follow the image of the object may solve these problems. The ISC must therefore be equipped with aberration correction optics capable of covering a sufficiently large primary field of view, of the order of a few degrees. In this paper we present optical and mechanical concepts for combined aberration correction and pupil densification using multimode deformable mirror (MDM) and mechanically amplified piezo actuator technologies. Among the advantages of such a system over large monolithic corrector optics is the relaxation of piston alignment requirements for primary segments.

  12. Researcher-Identified and Emergent Predictors of Pupil Control Ideologies: A Canadian Beginning Teacher Perspective

    ERIC Educational Resources Information Center

    Rideout, Glenn; Windle, Sheila

    2013-01-01

    The objectives of this study were (a) to identify the direction of pupil control ideology (PCI) shifts during participants' beginning teaching years, and (b) to identify a broader range of "emergent" (participant-identified) predictors of PCI that beginning teachers saw as accounting for the tendency for their classroom learning…

  13. Teacher's Sense of Power and the Consistency of Their Pupil Control Ideology and Behavior.

    ERIC Educational Resources Information Center

    Rose, Keith R.; Willower, Donald J.

    1981-01-01

    Responses from a sample of 71 secondary teachers and 1,272 students were consistent with the hypothesis that teachers' sense of power would be directly associated with the consistency of their beliefs and behavior concerning pupil control. Some speculations were advanced concerning additional influences on teacher belief-behavior consistency. (NEC)

  14. CSCL for Intellectually Disabled Pupils: Stimulating Interaction by Using a Floor Control Mechanism

    ERIC Educational Resources Information Center

    Cress, Ulrike; Wodzicki, Katrin; Bientzle, Martina; Lingnau, Andreas

    2011-01-01

    Computer-supported collaborative learning has an unexploited potential of becoming an effective learning method for pupils with intellectual disabilities. This paper aims at showing how some specific requirements of this target group may be met by structuring a learning situation with the help of "floor control," which restricts the opportunities…

  15. Pupil Control Ideology of Teachers As It Relates to Middle School Concepts.

    ERIC Educational Resources Information Center

    Hardesty, Lorraine

    This study tested the hypothesis that there will be statistically significant main effects and interaction effects for school level assignment (elementary, junior high, and senior high) and support for middle school organizational concepts on pupil control ideology. A random sample of 252 teachers participated. A two-way analysis of variance…

  16. The First Five Years of Teaching. Their Effect on Pupil Control Ideology and Commitment to Teaching.

    ERIC Educational Resources Information Center

    McArthur, John T.

    This paper reports some findings of a longitudinal study of a group of teachers during their final year of teacher training in 1972 through their first five years of teaching. The two features focused upon as indices of socialization are pupil control ideology and commitment to teaching. The major characteristics that are analyzed are sex,…

  17. Pre-Service Teachers' Beliefs and Other Predictors of Pupil Control Ideologies

    ERIC Educational Resources Information Center

    Rideout, Glenn W.; Morton, Larry L.

    2007-01-01

    Purpose: This study aims to examine a variety of demographic, experiential, and philosophical orientation variables that may be predictive of pupil control ideologies (PCI) for teacher candidates at the beginning of a pre-service program. In particular, it sets out to provide empirically grounded generalizations regarding the relationship between…

  18. Teacher Personality and Pupil Control Ideology: Associations with Response to Relational Aggression in the Classroom

    ERIC Educational Resources Information Center

    Gyllborg, Amy B.

    2015-01-01

    The current study investigated the associations between teacher personality and pupil control ideology and the way in which these variables impact the methods used by Midwestern teachers (n = 123) to respond to and intervene in hypothetical instances of relational aggression, presented via vignette. Regression analyses indicated that aspects of…

  19. Teacher Personality and Pupil Control Ideology: Associations with Response to Relational Aggression in the Classroom

    ERIC Educational Resources Information Center

    Gyllborg, Amy B.

    2015-01-01

    The current study investigated the associations between teacher personality and pupil control ideology and the way in which these variables impact the methods used by Midwestern teachers (n = 123) to respond to and intervene in hypothetical instances of relational aggression, presented via vignette. Regression analyses indicated that aspects of…

  20. Bureaucracy and Pupil Control Orientation and Behavior in Urban Secondary Schools.

    ERIC Educational Resources Information Center

    Lunenburg, Fred C.; Mankowsky, Scarlett A.

    Data collected from 297 teachers and 7,376 students in 20 urban high schools were used to examine relationships between dimensions of bureaucratic structure and pupil control orientation and behavior. Results of the analyses revealed two distinct patterns of rational organization. Hierarchy, rules, impersonality, and centralization comprised the…

  1. Pre-Service Teachers' Beliefs and Other Predictors of Pupil Control Ideologies

    ERIC Educational Resources Information Center

    Rideout, Glenn W.; Morton, Larry L.

    2007-01-01

    Purpose: This study aims to examine a variety of demographic, experiential, and philosophical orientation variables that may be predictive of pupil control ideologies (PCI) for teacher candidates at the beginning of a pre-service program. In particular, it sets out to provide empirically grounded generalizations regarding the relationship between…

  2. Pupil constrictions to photographs of the sun.

    PubMed

    Binda, Paola; Pereverzeva, Maria; Murray, Scott O

    2013-05-17

    The pupil constricts in response to light increments and dilates with light decrements. Here we show that a picture of the sun, introducing a small overall decrease in light level across the field of view, results in a pupillary constriction. Thus, the pictorial representation of a high-luminance object (the sun) can override the normal pupillary dilation elicited by a light decrement. In a series of experiments that control for a variety of factors known to modulate pupil size, we show that the effect (a) does not depend on the retinal position of the images and (b) is modulated by attention. It has long been known that cognitive factors can affect pupil diameter by producing pupillary dilations. Our results indicate that high-level visual analysis (beyond the simple subcortical system mediating the pupillary response to light) can also induce pupillary constriction, with an effect size of about 0.1 mm.

  3. Epimorphin Mediates Mammary Luminal Morphogenesis through Control of C/EBPβ

    PubMed Central

    Hirai, Yohei; Radisky, Derek; Boudreau, Rosanne; Simian, Marina; Stevens, Mary E.; Oka, Yumiko; Takebe, Kyoko; Niwa, Shinichiro; Bissell, Mina J.

    2001-01-01

    We have shown previously that epimorphin (EPM), a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which EPM mediates luminal morphogenesis. Treatment of cells with EPM to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein (C/EBP)β and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, since constitutive expression of LIP was sufficient to produce lumen formation, whereas constitutive expression of LAP blocked EPM-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which EPM expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBPβ, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for EPM in luminal morphogenesis through control of C/EBPβ expression. PMID:11352939

  4. Epimorphin mediates mammary luminal morphogenesis through control of C/EBPbeta

    SciTech Connect

    Hirai, Yohei; Radisky, Derek; Boudreau, Rosanne; Simian, Marina; Stevens, Mary E.; Oka, Yumiko; Takebe, Kyoko; Niwa, Shinichiro; Bissell, Mina J.

    2002-03-22

    We have previously shown that epimorphin, a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which epimorphin mediates luminal morphogenesis. Treatment of cells with epimorphin to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, as constitutive expression of LIP was sufficient to produce lumen formation, while constitutive expression of LAP blocked epimorphin-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which epimorphin expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBPbeta, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for epimorphin in luminal morphogenesis through control of C/EBPbeta expression.

  5. The Development and Factor Structure of a Career Locus of Control Scale for Use with School Pupils

    ERIC Educational Resources Information Center

    Millar, Rob; Shevlin, Mark

    2007-01-01

    This article describes the development and psychometric assessment of a multidimensional, domain-specific Career Locus of Control Scale (CLOC) designed for use with adolescent school pupils engaged in the career development and decision-making process. A 47-item version was administered to 743 school pupils, age 15 or 16 years evenly split between…

  6. Tailoring of Luminous Transmittance upon Switching for Thermochromic VO2 Films by Thickness Control

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Jin, Ping; Tazawa, Masato; Yoshimura, Kazuki

    2004-01-01

    The difference in luminous transmittance (Δ Tlum) upon switching of VO2 films strongly affects its solar controllability when used as a thermochromic window. It was found that Δ Tlum is controllable by film thickness. Optical calculation for a VO2 film on quartz glass revealed that the low-temperature semiconductor phase exhibits lower Tlum than the high-temperature metallic phase for thickness below 50 nm, while the relationship is reversed above 50 nm. The calculation was confirmed by film deposition and measurement. Maximum Δ Tlum is located near 80 nm. An enhanced Δ Tlum contributes largely to solar efficiency.

  7. Intelligent Luminance Control of Lighting Systems Based on Imaging Sensor Feedback

    PubMed Central

    Liu, Haoting; Zhou, Qianxiang; Yang, Jin; Jiang, Ting; Liu, Zhizhen; Li, Jie

    2017-01-01

    An imaging sensor-based intelligent Light Emitting Diode (LED) lighting system for desk use is proposed. In contrast to the traditional intelligent lighting system, such as the photosensitive resistance sensor-based or the infrared sensor-based system, the imaging sensor can realize a finer perception of the environmental light; thus it can guide a more precise lighting control. Before this system works, first lots of typical imaging lighting data of the desk application are accumulated. Second, a series of subjective and objective Lighting Effect Evaluation Metrics (LEEMs) are defined and assessed for these datasets above. Then the cluster benchmarks of these objective LEEMs can be obtained. Third, both a single LEEM-based control and a multiple LEEMs-based control are developed to realize a kind of optimal luminance tuning. When this system works, first it captures the lighting image using a wearable camera. Then it computes the objective LEEMs of the captured image and compares them with the cluster benchmarks of the objective LEEMs. Finally, the single LEEM-based or the multiple LEEMs-based control can be implemented to get a kind of optimal lighting effect. Many experiment results have shown the proposed system can tune the LED lamp automatically according to environment luminance changes. PMID:28208781

  8. Intelligent Luminance Control of Lighting Systems Based on Imaging Sensor Feedback.

    PubMed

    Liu, Haoting; Zhou, Qianxiang; Yang, Jin; Jiang, Ting; Liu, Zhizhen; Li, Jie

    2017-02-09

    An imaging sensor-based intelligent Light Emitting Diode (LED) lighting system for desk use is proposed. In contrast to the traditional intelligent lighting system, such as the photosensitive resistance sensor-based or the infrared sensor-based system, the imaging sensor can realize a finer perception of the environmental light; thus it can guide a more precise lighting control. Before this system works, first lots of typical imaging lighting data of the desk application are accumulated. Second, a series of subjective and objective Lighting Effect Evaluation Metrics (LEEMs) are defined and assessed for these datasets above. Then the cluster benchmarks of these objective LEEMs can be obtained. Third, both a single LEEM-based control and a multiple LEEMs-based control are developed to realize a kind of optimal luminance tuning. When this system works, first it captures the lighting image using a wearable camera. Then it computes the objective LEEMs of the captured image and compares them with the cluster benchmarks of the objective LEEMs. Finally, the single LEEM-based or the multiple LEEMs-based control can be implemented to get a kind of optimal lighting effect. Many experiment results have shown the proposed system can tune the LED lamp automatically according to environment luminance changes.

  9. Parafoveal Target Detectability Reversal Predicted by Local Luminance and Contrast Gain Control

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Beard, Bettina L.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    This project is part of a program to develop image discrimination models for the prediction of the detectability of objects in a range of backgrounds. We wanted to see if the models could predict parafoveal object detection as well as they predict detection in foveal vision. We also wanted to make our simplified models more general by local computation of luminance and contrast gain control. A signal image (0.78 x 0.17 deg) was made by subtracting a simulated airport runway scene background image (2.7 deg square) from the same scene containing an obstructing aircraft. Signal visibility contrast thresholds were measured in a fully crossed factorial design with three factors: eccentricity (0 deg or 4 deg), background (uniform or runway scene background), and fixed-pattern white noise contrast (0%, 5%, or 10%). Three experienced observers responded to three repetitions of 60 2IFC trials in each condition and thresholds were estimated by maximum likelihood probit analysis. In the fovea the average detection contrast threshold was 4 dB lower for the runway background than for the uniform background, but in the parafovea, the average threshold was 6 dB higher for the runway background than for the uniform background. This interaction was similar across the different noise levels and for all three observers. A likely reason for the runway background giving a lower threshold in the fovea is the low luminance near the signal in that scene. In our model, the local luminance computation is controlled by a spatial spread parameter. When this parameter and a corresponding parameter for the spatial spread of contrast gain were increased for the parafoveal predictions, the model predicts the interaction of background with eccentricity.

  10. Tourette Syndrome: Complementary Insights from Measures of Cognitive Control, Eyeblink Rate, and Pupil Diameter.

    PubMed

    Tharp, Jordan A; Wendelken, Carter; Mathews, Carol A; Marco, Elysa J; Schreier, Herbert; Bunge, Silvia A

    2015-01-01

    Some individuals with Tourette syndrome (TS) have severe motoric and vocal tics that interfere with all aspects of their lives, while others have mild tics that pose few problems. We hypothesize that observed tic severity reflects a combination of factors, including the degree to which dopaminergic (DA) and/or noradrenergic (NE) neurotransmitter systems have been affected by the disorder, and the degree to which the child can exert cognitive control to suppress unwanted tics. To explore these hypotheses, we collected behavioral and eyetracking data from 26 patients with TS and 26 controls between ages 7 and 14, both at rest and while they performed a test of cognitive control. To our knowledge, this is the first study to use eyetracking measures in patients with TS. We measured spontaneous eyeblink rate as well as pupil diameter, which have been linked, respectively, to DA and NE levels in the central nervous system. Here, we report a number of key findings that held when we restricted analyses to unmedicated patients. First, patients' accuracy on our test of cognitive control accounted for fully 50% of the variance in parentally reported tic severity. Second, patients exhibited elevated spontaneous eyeblink rates compared to controls, both during task performance and at rest, consistent with heightened DA transmission. Third, although neither task-evoked pupil dilation nor resting pupil diameter differed between TS patients and controls, pupil diameter was positively related to parentally reported anxiety levels in patients, suggesting heightened NE transmission in patients with comorbid anxiety. Thus, with the behavioral and eyetracking data gathered from a single task, we can gather objective data that are related both to tic severity and anxiety levels in pediatric patients with TS, and that likely reflect patients' underlying neurochemical disturbances.

  11. Teacher Pupil Control Ideology and Behavior and Classroom Environmental Robustness.

    ERIC Educational Resources Information Center

    Willower, Donald J.; And Others

    Two hypotheses were tested investigating the relationship between beliefs and behaviors of teachers in controlling students and student perceptions of classroom excitement. It was hypothesized that direct relationships would exist between teacher strictness in beliefs and behaviors toward student control and the students' opinions concerning the…

  12. Table lamp with dynamically controlled lighting distribution and uniformly illuminated luminous shade

    DOEpatents

    Siminovitch, Michael J.; Page, Erik R.

    2002-01-01

    A double lamp table or floor lamp lighting system has a pair of compact fluorescent lamps (CFLs) or other lamps arranged vertically, i.e. one lamp above the other, with a reflective septum in between. By selectively turning on one or both of the CFLs, down lighting, up lighting, or both up and down lighting is produced. The control system can also vary the light intensity from each CFL. The reflective septum ensures that almost all the light produced by each lamp will be directed into the desired light distribution pattern which is selected and easily changed by the user. In a particular configuration, the reflective septum is bowl shaped, with the upper CFL sitting in the bowl, and a luminous shade hanging down from the bowl. The lower CFL provides both task lighting and uniform shade luminance. Planar compact fluorescent lamps, e.g. circular CFLs, particularly oriented horizontally, are preferable. CFLs provide energy efficiency. However, other types of lamps, including incandescent, halogen, and LEDs can also be used in the fixture. The lighting system may be designed for the home, hospitality, office or other environments.

  13. Phase and Pupil Amplitude Recovery for JWST Space-Optics Control

    NASA Technical Reports Server (NTRS)

    Dean, B. H.; Zielinski, T. P.; Smith, J. S.; Bolcar, M. R.; Aronstein, D. L.; Fienup, J. R.

    2010-01-01

    This slide presentation reviews the phase and pupil amplitude recovery for the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam). It includes views of the Integrated Science Instrument Module (ISIM), the NIRCam, examples of Phase Retrieval Data, Ghost Irradiance, Pupil Amplitude Estimation, Amplitude Retrieval, Initial Plate Scale Estimation using the Modulation Transfer Function (MTF), Pupil Amplitude Estimation vs lambda, Pupil Amplitude Estimation vs. number of Images, Pupil Amplitude Estimation vs Rotation (clocking), and Typical Phase Retrieval Results Also included is information about the phase retrieval approach, Non-Linear Optimization (NLO) Optimized Diversity Functions, and Least Square Error vs. Starting Pupil Amplitude.

  14. miR-221/222 control luminal breast cancer tumor progression by regulating different targets.

    PubMed

    Dentelli, Patrizia; Traversa, Matteo; Rosso, Arturo; Togliatto, Gabriele; Olgasi, Cristina; Marchiò, Caterina; Provero, Paolo; Lembo, Antonio; Bon, Giulia; Annaratone, Laura; Sapino, Anna; Falcioni, Rita; Brizzi, Maria Felice

    2014-01-01

    α6β4 integrin is an adhesion molecule for laminin receptors involved in tumor progression. We present a link between β4 integrin expression and miR-221/222 in the most prevalent human mammary tumor: luminal invasive carcinomas (Lum-ICs). Using human primary tumors that display different β4 integrin expression and grade, we show that miR-221/222 expression inversely correlates with tumor proliferating index, Ki67. Interestingly, most high-grade tumors express β4 integrin and low miR-221/222 levels. We ectopically transfected miR-221/222 into a human-derived mammary tumor cell line that recapitulates the luminal subtype to investigate whether miR-221/222 regulates β4 expression. We demonstrate that miR-221/222 overexpression results in β4 expression downregulation, breast cancer cell proliferation, and invasion inhibition. The role of miR-221/222 in driving β4 integrin expression is also confirmed via mutating the miR-221/222 seed sequence for β4 integrin 3'UTR. Furthermore, we show that these 2 miRNAs are also key breast cancer cell proliferation and invasion regulators, via the post-transcriptional regulation of signal transducer and activator of transcription 5A (STAT5A) and of a disintegrin and metalloprotease-17 (ADAM-17). We further confirm these data by silencing ADAM-17, using a dominant-negative or an activated STAT5A form. miR-221/222-driven β4 integrin, STAT5A, and ADAM-17 did not occur in MCF-10A cells, denoted "normal" breast epithelial cells, indicating that the mechanism is cancer cell-specific.   These results provide the first evidence of a post-transcriptional mechanism that regulates β4 integrin, STAT5A, and ADAM-17 expression, thus controlling breast cancer cell proliferation and invasion. Pre-miR-221/222 use in the aggressive luminal subtype may be a powerful therapeutic anti-cancer strategy.

  15. Beam control for LINC-NIRVANA: from the binocular entrance pupil to the combined focal plane

    NASA Astrophysics Data System (ADS)

    Bertram, T.; Trowitzsch, J.; Herbst, T. M.; Ragazzoni, R.

    2012-07-01

    LINC-NIRVANA is the near-infrared interferometric imaging camera for the Large Binocular Telescope. Once operational, it will provide an unprecedented combination of angular resolution, sensitivity and field of view. To meet the tight requirements that result from long exposure interferometric imaging over a large field of view, active control beyond fringe tracking and adaptive optics has to be in place in the telescope and in the instrument domain. The incoming beams of the binocular telescope have to be controlled along the entire optical path, from the entrance pupil to the combined focal plane. The beams have to coincide in the focal plane of the science detector, their pointing origins, offsets, orientations, plate scales, and distortions have to match each other and must not change during the observation. Non-common path effects between AO and science channel, flexure and thermal effects have to be compensated and offioading requests from the adaptive optics and fringe tracking systems have to be arbitrated without introducing unwanted optical path length differences or changes in the geometry of the binocular entrance pupil. Beam Control aspects include pointing, co-pointing and field derotation, active optics and collimation control. In this presentation, the constraints for coherent imaging over a 1.5 arcminute field of view are discussed together with a concept for a distributed control scheme.

  16. Teacher-Pupil Relationships: Black Students' Perceptions of Actual and Ideal Teacher/Pupil Control Behavior and Attitudes Toward Teachers and School

    ERIC Educational Resources Information Center

    Sweeting, Lurlene M.; And Others

    1978-01-01

    Regardless of the direction of pupils' preferences (humanistic or custodial) the more closely pupils' perceptions of their teachers' actual behavior approximated their conception of ideal teacher behavior, the more positive were their attitudes toward teacher and school. (Author)

  17. The relationship of pupil control to preservice elementary science teacher self-efficacy and outcome expectancy

    NASA Astrophysics Data System (ADS)

    Enochs, Larry G.; Scharmann, Lawrence C.; Riggs, Iris M.

    The investigators' intentions in this study were to examine preservice elementary teachers' sense of self-efficacy with regard to science teaching and to define the construct of self-efficacy with greater clarity. Additionally, the construct of pupil control was examined. To gather information toward these purposes, we investigated the following questions: Do prospective elementary teachers' efficacy beliefs relate to their beliefs concerning classroom management or control?; and How is a measure of self-efficacy related to prospective teachers' self-reported choice concerning the teaching of science, amount of time spent in performing hands-on science, and/or perceived effectiveness as future elementary science teachers? Self-efficacy was measured as two distinct constructs, personal self-efficacy and outcome expectancy. Significant correlations were found between personal science teaching self-efficacy and (1) the number of college science courses taken; (2) the number of years of high school science taken; (3) respondent's choice of science instructional delivery; and (4) respondent's perceived effectiveness in teaching science. When the outcome expectancy subscale is considered, however, only one significant correlation is indicated; perceived effectiveness in teaching science was significantly correlated with outcome expectancy. Personal science teaching self-efficacy was significantly correlated with pupil control ideology while outcome expectancy was not.

  18. Pupil diameter tracks changes in control state predicted by the adaptive gain theory of locus coeruleus function

    PubMed Central

    Gilzenrat, Mark S.; Nieuwenhuis, Sander; Jepma, Marieke; Cohen, Jonathan D.

    2010-01-01

    An important dimension of cognitive control is the adaptive regulation of the balance between exploitation (pursuing known sources of reward) and exploration (seeking new ones) in response to changes in task utility. Recent studies have suggested that the locus coeruleus–norepinephrine system may play an important role in this function and that pupil diameter can be used to index locus coeruleus activity. On the basis of this, we reasoned that pupil diameter may correlate closely with control state and associated changes in behavior. Specifically, we predicted that increases in baseline pupil diameter would be associated with decreases in task utility and disengagement from the task (exploration), whereas reduced baseline diameter (but increases in task-evoked dilations) would be associated with task engagement (exploitation). Findings in three experiments were consistent with these predictions, suggesting that pupillometry may be useful as an index of both control state and, indirectly, locus coeruleus function. PMID:20498349

  19. Pupil diameter tracks changes in control state predicted by the adaptive gain theory of locus coeruleus function.

    PubMed

    Gilzenrat, Mark S; Nieuwenhuis, Sander; Jepma, Marieke; Cohen, Jonathan D

    2010-05-01

    An important dimension of cognitive control is the adaptive regulation of the balance between exploitation (pursuing known sources of reward) and exploration (seeking new ones) in response to changes in task utility. Recent studies have suggested that the locus coeruleus-norepinephrine system may play an important role in this function and that pupil diameter can be used to index locus coeruleus activity. On the basis of this, we reasoned that pupil diameter may correlate closely with control state and associated changes in behavior. Specifically, we predicted that increases in baseline pupil diameter would be associated with decreases in task utility and disengagement from the task (exploration), whereas reduced baseline diameter (but increases in task-evoked dilations) would be associated with task engagement (exploitation). Findings in three experiments were consistent with these predictions, suggesting that pupillometry may be useful as an index of both control state and, indirectly, locus coeruleus function.

  20. Expression of squid iridescence depends on environmental luminance and peripheral ganglion control.

    PubMed

    Gonzalez-Bellido, P T; Wardill, T J; Buresch, K C; Ulmer, K M; Hanlon, R T

    2014-03-15

    Squid display impressive changes in body coloration that are afforded by two types of dynamic skin elements: structural iridophores (which produce iridescence) and pigmented chromatophores. Both color elements are neurally controlled, but nothing is known about the iridescence circuit, or the environmental cues, that elicit iridescence expression. To tackle this knowledge gap, we performed denervation, electrical stimulation and behavioral experiments using the long-fin squid, Doryteuthis pealeii. We show that while the pigmentary and iridescence circuits originate in the brain, they are wired differently in the periphery: (1) the iridescence signals are routed through a peripheral center called the stellate ganglion and (2) the iridescence motor neurons likely originate within this ganglion (as revealed by nerve fluorescence dye fills). Cutting the inputs to the stellate ganglion that descend from the brain shifts highly reflective iridophores into a transparent state. Taken together, these findings suggest that although brain commands are necessary for expression of iridescence, integration with peripheral information in the stellate ganglion could modulate the final output. We also demonstrate that squid change their iridescence brightness in response to environmental luminance; such changes are robust but slow (minutes to hours). The squid's ability to alter its iridescence levels may improve camouflage under different lighting intensities.

  1. Teachers' Experiences of Using Eye Gaze-Controlled Computers for Pupils with Severe Motor Impairments and without Speech

    ERIC Educational Resources Information Center

    Rytterström, Patrik; Borgestig, Maria; Hemmingsson, Helena

    2016-01-01

    The purpose of this study is to explore teachers' experiences of using eye gaze-controlled computers with pupils with severe disabilities. Technology to control a computer with eye gaze is a fast growing field and has promising implications for people with severe disabilities. This is a new assistive technology and a new learning situation for…

  2. Teachers' Experiences of Using Eye Gaze-Controlled Computers for Pupils with Severe Motor Impairments and without Speech

    ERIC Educational Resources Information Center

    Rytterström, Patrik; Borgestig, Maria; Hemmingsson, Helena

    2016-01-01

    The purpose of this study is to explore teachers' experiences of using eye gaze-controlled computers with pupils with severe disabilities. Technology to control a computer with eye gaze is a fast growing field and has promising implications for people with severe disabilities. This is a new assistive technology and a new learning situation for…

  3. Pupil Size in Outdoor Environments

    DTIC Science & Technology

    2007-04-06

    tripod using a slanted riser so the photographer could take pictures of the eye at an upward angle to minimize interference of the image with the...luminance measurements for each of the three average pupil sizes in the 20-year age group range from approximately 3000 to 4100 cd·m-2 but the

  4. A Semi-Automatic, Remote-Controlled Video Observation System for Transient Luminous Events

    NASA Astrophysics Data System (ADS)

    Allin, T.; Neubert, T.; Laursen, S.; Rasmussen, I. L.; Soula, S.

    2003-12-01

    In support for global ELF/VLF observations, HF measurements in France, and conjugate photometry/VLF observations in South Africa, we developed and operated a semi-automatic, remotely controlled video system for the observation of middle-atmospheric transient luminous events (TLEs). Installed at the Pic du Midi Observatory in Southern France, the system was operational during the period from July 18 to September 15, 2003. The video system, based two low-light, non-intensified CCD video cameras, was mounted on top of a motorized pan/tilt unit. The cameras and the pan/tilt unit were controlled over serial links from a local computer, and the video outputs were distributed to a pair of PCI frame grabbers in the computer. This setup allowed remote users to log in and operate the system over the internet. Event detection software provided means of recording and time-stamping single TLE video fields and thus eliminated the need for continuous human monitoring of TLE activity. The computer recorded and analyzed two parallel video streams at the full 50 Hz field rate, while uploading status images, TLE images, and system logs to a remote web server. The system detected more than 130 TLEs - mostly sprites - distributed over 9 active evenings. We have thus demonstrated the feasibility of remote agents for TLE observations, which are likely to find use in future ground-based TLE observation campaigns, or to be installed at remote sites in support for space-borne or other global TLE observation efforts.

  5. The impact of luminance on tonic and phasic pupillary responses to sustained cognitive load.

    PubMed

    Peysakhovich, Vsevolod; Vachon, François; Dehais, Frédéric

    2017-02-01

    Pupillary reactions independent of light conditions have been linked to cognition for a long time. However, the light conditions can impact the cognitive pupillary reaction. Previous studies underlined the impact of luminance on pupillary reaction, but it is still unclear how luminance modulates the sustained and transient components of pupillary reaction - tonic pupil diameter and phasic pupil response. In the present study, we investigated the impact of the luminance on these two components under sustained cognitive load. Fourteen participants performed a novel working memory task combining mathematical computations with a classic n-back task. We studied both tonic pupil diameter and phasic pupil response under low (1-back) and high (2-back) working memory load and two luminance levels (gray and white). We found that the impact of working memory load on the tonic pupil diameter was modulated by the level of luminance, the increase in tonic pupil diameter with the load being larger under lower luminance. In contrast, the smaller phasic pupil response found under high load remained unaffected by luminance. These results showed that luminance impacts the cognitive pupillary reaction - tonic pupil diameter (phasic pupil response) being modulated under sustained (respectively, transient) cognitive load. These findings also support the relationship between the locus-coeruleus system, presumably functioning in two firing modes - tonic and phasic - and the pupil diameter. We suggest that the tonic pupil diameter tracks the tonic activity of the locus-coeruleus while phasic pupil response reflects its phasic activity. Besides, the designed novel cognitive paradigm allows the simultaneous manipulation of sustained and transient components of the cognitive load and is useful for dissociating the effects on the tonic pupil diameter and phasic pupil response.

  6. American Indian Students' Perceptions of Actual and Ideal Dormitory Aide Pupil Control Behavior, and Students' Attitudes Regarding Their Dormitory Aides.

    ERIC Educational Resources Information Center

    Davis, Jim L.

    Two hundred and eleven American Indian students (106 males and 105 females) attending an off-reservation BIA elementary boarding school in a predominantly non-Indian community in the midwest were tested to examine the relationship between the congruence of students' perception of and preferences for dormitory aide pupil control behavior and…

  7. Large pupils predict goal-driven eye movements.

    PubMed

    Mathôt, Sebastiaan; Siebold, Alisha; Donk, Mieke; Vitu, Françoise

    2015-06-01

    Here we report that large pupils predict fixations of the eye on low-salient, inconspicuous parts of a visual scene. We interpret this as showing that mental effort, reflected by a dilation of the pupil, is required to guide gaze toward objects that are relevant to current goals, but that may not be very salient. When mental effort is low, reflected by a constriction of the pupil, the eyes tend to be captured by high-salient parts of the image, irrespective of top-down goals. The relationship between pupil size and visual saliency was not driven by luminance or a range of other factors that we considered. Crucially, the relationship was strongest when mental effort was invested exclusively in eye-movement control (i.e., reduced in a dual-task setting), which suggests that it is not due to general effort or arousal. Our finding illustrates that goal-driven control during scene viewing requires mental effort, and that pupil size can be used as an online measure to track the goal-drivenness of behavior. (c) 2015 APA, all rights reserved).

  8. Luminous supernovae.

    PubMed

    Gal-Yam, Avishay

    2012-08-24

    Supernovae, the luminous explosions of stars, have been observed since antiquity. However, various examples of superluminous supernovae (SLSNe; luminosities >7 × 10(43) ergs per second) have only recently been documented. From the accumulated evidence, SLSNe can be classified as radioactively powered (SLSN-R), hydrogen-rich (SLSN-II), and hydrogen-poor (SLSN-I, the most luminous class). The SLSN-II and SLSN-I classes are more common, whereas the SLSN-R class is better understood. The physical origins of the extreme luminosity emitted by SLSNe are a focus of current research.

  9. The effects of human relations training on reported teacher stress, pupil control ideology and locus of control.

    PubMed

    Hall, E; Hall, C; Abaci, R

    1997-12-01

    This study presents the reported outcomes of a two-year, part-time Masters' programme in human relations using an experiential learning methodology based mainly on humanistic psychological theory. The following hypotheses were examined. That as a result of the two-year programme: the experience of reported stress would be reduced; reported attitudes to student classroom control would shift from custodial to humanistic; there would be an increase in reports from participants of a sense of control over their lives; changes of behaviour in work, social settings and at home related to these three variables would be reported. Involved in the study were 42 experienced teachers. These included 32 women and 10 men, with an average age of 35, who worked in a wide range of educational institutions. Their learning style preferences were also considered as independent variables. A control group of 42 was established with similar demographic characteristics. Prior to the course, the experimental group and the control group were given the Maslach Burnout Inventory and the Pupil Control Ideology Form. In the early stages of the course, the experimental group completed the Kolb Learning Style Inventory and an informal measure of locus of control which was repeated at the end of the first year of the course. A sample of 32 from the experimental group were given semi-structured interviews relating to changes in their professional and personal lives. The results indicated that, following the training, there was a reduction in reported stress, indications of a more humanistic orientation towards pupil control and an increase in a sense of an internal locus of control. The quantitative data were confirmed by qualitative data generated from semi-structured interviews, which involved substantial reports of applications of the training in their professional and personal lives. These results provide support for including experiential human relations training as part of both the in

  10. Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance

    PubMed Central

    Brascamp, Jan; Nuiten, Stijn; Hoppenbrouwers, Sylco; Theeuwes, Jan

    2016-01-01

    Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic) changes in pupil size that differentially influenced faster (phasic) pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software. PMID:27191166

  11. Nanoporous thermochromic VO₂ (M) thin films: controlled porosity, largely enhanced luminous transmittance and solar modulating ability.

    PubMed

    Cao, Xun; Wang, Ning; Law, Jia Yan; Loo, Say Chye Joachim; Magdassi, Shlomo; Long, Yi

    2014-02-18

    Vanadium dioxide is the most widely researched thermochromic material with a phase transition temperature (τ(c)) of around 68 °C, and its thermochromic performance can be enhanced by adding nanoporosity. Freeze-drying has been employed to fabricate nanostructures with different porosities from 16 to 45% by varying the prefreezing temperature and precursor concentration. The luminous transmittance (Tlum) and solar modulating ability (ΔTsol) are greatly enhanced as a result of increasing pore size and pore density. The freeze-dried sample with 7.5 mL of H2O2 precursor dip-coated at 300 mm/min gives the best combination of thermochromic properties (Tlum ≈ 50%, ΔTsol = 14.7%), which surpasses the best combined thermochromic performance reported to date that we are aware of (Tlum ≈ 41%, ΔTsol = 14.1%).

  12. Luminous presence

    NASA Astrophysics Data System (ADS)

    Dawson, Paula

    2008-02-01

    The Luminous Presence project examines the use of standard film language in the framing, angle and of points of view of holographic subjects though eight digital holographic stereograms; seven 25 x 25 cm, Hail, Water, Rain, Snow, Sun, Text, Imprint and 1.5 x 1 m, Luminous Presences i. However, before embarking on a discussion of how filmic language can be used in digital holograms it is first important to explain why this line of investigation could be fruitful. Undoubtedly several of the compositional practices which sprung up and evolved throughout the development of the diverse forms of the holographic medium have contributed to a unique hologram pictorial language, however it is well known that the reading of visual imagery of any type relies a great deal on the viewer's knowledge of and experience of other images .The lens-recorded imagery of film is a far more familiar language than that of holograms and the correlation between certain filmic pictorial conventions and emotional responses are well documented and understood. ii . In short the language of film contains a highly nuanced vocabulary of shot types and lens types (which may be criticised as being formulaic) yet are effective in lending emotion to figures.

  13. Pupil Transportation.

    ERIC Educational Resources Information Center

    Stollar, Dewey H.

    The purpose of this NEFP satellite study is to provide an overview of pupil transportation. The first phase of the study discusses the early legal and financial bases for student transportation, the second the current status of student transportation, and the third the future status of student transportation needs and financing for 1980.…

  14. Economics Pupils

    ERIC Educational Resources Information Center

    Scott, Alexander; Straker-Cook, Dawn

    1976-01-01

    This paper contains survey information relating to the relative performance of economics pupils at"A" level, their feelings about the subject, and the type of teaching to which they are exposed. The primary concern is to stimulate debate about the issues raised. Journal is available from: Economics Association, Room 340, Hamilton House, Mabledon…

  15. Investigation of Color Constancy in 4.5-Month-Old Infants under a Strict Control of Luminance Contrast for Individual Participants

    ERIC Educational Resources Information Center

    Yang, Jiale; Kanazawa, So; Yamaguchi, Masami K.; Kuriki, Ichiro

    2013-01-01

    The current study examined color constancy in infants using a familiarization paradigm. We first obtained isoluminance in each infant as defined by the minimum motion paradigm and used these data to control the luminance of stimuli in the main experiments. In the familiarization phase of the main experiment, two identical smiling face patterns…

  16. Investigation of Color Constancy in 4.5-Month-Old Infants under a Strict Control of Luminance Contrast for Individual Participants

    ERIC Educational Resources Information Center

    Yang, Jiale; Kanazawa, So; Yamaguchi, Masami K.; Kuriki, Ichiro

    2013-01-01

    The current study examined color constancy in infants using a familiarization paradigm. We first obtained isoluminance in each infant as defined by the minimum motion paradigm and used these data to control the luminance of stimuli in the main experiments. In the familiarization phase of the main experiment, two identical smiling face patterns…

  17. Improved human visuomotor performance and pupil constriction after choline supplementation in a placebo-controlled double-blind study

    PubMed Central

    Naber, Marnix; Hommel, Bernhard; Colzato, Lorenza S.

    2015-01-01

    Only few nutrients are known to enhance cognition. Here we explore whether visuomotor performance can be improved through the intake of the nutrient choline, an essential chemical compound in a vertebrate’s diet. Choline is abundant in for example eggs and shrimps and many animal studies suggest that it serves as a cognitive enhancer. As choline is important for the communication between motor neurons and the control of skeletal muscles, we assumed that choline supplementation may have positive effects on action coordination in humans. A group of twenty-eight individuals ingested two grams of choline bitartrate or a placebo in two separate sessions. Seventy minutes post ingestion, participants performed a visuomotor aiming task in which they had to rapidly hit the centers of targets. Results showed that participants hit targets more centrally after choline supplementation. Pupil size (a cognition-sensitive biomarker) also significantly decreased after choline intake and correlated positively with the hit distance to the targets and the number of target misses, and negatively with reaction times. These findings point to a choline-induced bias towards action precision in the trade-off between speed and accuracy. The changes in pupil size suggest that choline uptake alters cholinergic functions in the nervous system. PMID:26271904

  18. Eye Movement Control during Scene Viewing: Immediate Effects of Scene Luminance on Fixation Durations

    ERIC Educational Resources Information Center

    Henderson, John M.; Nuthmann, Antje; Luke, Steven G.

    2013-01-01

    Recent research on eye movements during scene viewing has primarily focused on where the eyes fixate. But eye fixations also differ in their durations. Here we investigated whether fixation durations in scene viewing are under the direct and immediate control of the current visual input. Subjects freely viewed photographs of scenes in preparation…

  19. Eye Movement Control during Scene Viewing: Immediate Effects of Scene Luminance on Fixation Durations

    ERIC Educational Resources Information Center

    Henderson, John M.; Nuthmann, Antje; Luke, Steven G.

    2013-01-01

    Recent research on eye movements during scene viewing has primarily focused on where the eyes fixate. But eye fixations also differ in their durations. Here we investigated whether fixation durations in scene viewing are under the direct and immediate control of the current visual input. Subjects freely viewed photographs of scenes in preparation…

  20. Effects of consciousness and consistency in manual control of visual stimulus on reduction of the flash-lag effect for luminance change.

    PubMed

    Ichikawa, Makoto; Masakura, Yuko

    2013-01-01

    Four experiments investigated how observers' consciousness about their control of stimulus change affects the visual perception associated with the illusory flash-lag effect. In previous study (Ichikawa and Masakura, 2006), we found that the flash-lag effect in motion is reduced if observers were conscious that they were controlling stimulus movements by the use of computer mouse, even if the stimulus moved automatically, independently of observer's mouse control. In the other study (Ichikawa and Masakura, 2010a), we found that the consistent directional relationship between the observer's mouse control and stimulus movement, which is learned in our everyday computer use, is important for the reduction of the flash-lag effect in active observation. In the present study, we examined whether the reduction of the flash-lag effect in active observation requires the observers' consciousness about their control of stimulus change, and consistency in coupling mouse movement direction and stimulus change across trials in experiments. We used the flash-lag effect in luminance change because there is no intrinsic relationship between observer's mouse control and luminance change in our everyday computer use. We compared the illusory flash-lag effects for automatic change of the luminance with luminance change that was controlled by the observers' active manipulation of a computer mouse. Because the flash occurs randomly in time, observers could not anticipate when the flash was presented. Results suggest that the not only observer's consciousness of controlling the stimulus, but also consistency in coupling mouse movement direction with stimulus change, are required for the reduction of the flash-lag effect in active observation. The basis of the reduction of the flash-lag effect in active observation is discussed.

  1. Wave-Optics Analysis of Pupil Imaging

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H.; Bos, Brent J.

    2006-01-01

    Pupil imaging performance is analyzed from the perspective of physical optics. A multi-plane diffraction model is constructed by propagating the scalar electromagnetic field, surface by surface, along the optical path comprising the pupil imaging optical system. Modeling results are compared with pupil images collected in the laboratory. The experimental setup, although generic for pupil imaging systems in general, has application to the James Webb Space Telescope (JWST) optical system characterization where the pupil images are used as a constraint to the wavefront sensing and control process. Practical design considerations follow from the diffraction modeling which are discussed in the context of the JWST Observatory.

  2. [Pupil and melanopsin photoreception].

    PubMed

    Ishikawa, Hitoshi

    2013-03-01

    photoreceptor cells, and to evaluate the relative contribution of pupil light response using the control, instigated pharmacological blockade of neurotransmission (PB) model and a transgenic model of retinal degeneration (Tg) rabbit. Although rod and cone photoreceptors disappeared in the PB and Tg models, miosis was still induced during exposure to blue light (470 nm). The greater sustained constriction of pupils to blue light in eyes with outer retinal damage reflects mRGC activation. Our study also indicated that some histologically-identified RGCs were consistent with the characteristics and structures of mRGC. Clinically, in age-related macular degeneration patients, there was no reliable recordable pupil response to red light, even at the brightest intensity but a blue light evoked a sustained pupil constriction. However, in glaucoma patients, there was no reliable recordable pupil response to the brightest intensity of blue light. These preliminary recordings in human subjects demonstrate that changes in the pupil responses to chromatic stimuli are readily detectable and easily quantifiable with standard instruments of clinical testing. We hypothesize that changes in the transient pupil response to red light and low intensity blue light may be more sensitive to cone and rod disease, whereas changes in the sustained pupil response to bright blue light may be more sensitive to optic nerve disease. Ongoing studies of the pupil are aimed at optimizing stimulus conditions that elicit pupil responses that can better localize the site of damage to rods, cones, and RGCs, to quantify the extent of disease.

  3. Coupling between pupil fluctuations and resting-state fMRI uncovers a slow build-up of antagonistic responses in the human cortex.

    PubMed

    Yellin, Dov; Berkovich-Ohana, Aviva; Malach, Rafael

    2015-02-01

    Even in absence of overt tasks, the human cortex manifests rich patterns of spontaneous "resting state" BOLD-fMRI fluctuations. However, the link of these spontaneous fluctuations to behavior is presently unclear. Attempts to directly investigate this link invariably lead to disruptions of the resting state. Here we took advantage of the well-established association between pupil diameter and attentional gain to address this issue by examining the correlation between the resting state BOLD and pupil fluctuations. Our results uncover a spontaneously emerging spatiotemporal pupil-BOLD correlation whereby a slow buildup of activity in default mode areas preceded both pupil dilation and wide-spread BOLD suppression in sensorimotor cortex. Control experiments excluded a role for luminance fluctuations or fixation. Comparing the pupil-correlated patterns to activation maps during visual imagery revealed a substantial overlap. Our results indicate a link between behavior, as indexed by pupil diameter, and resting state BOLD fluctuations. These pupil dilations, assumed to be related to attentional gain, were associated with spontaneously emerging antagonism between fundamental cortical networks. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. The Effects of Parental Involvement, Trust in Parents, Trust in Students and Pupil Control Ideology on Conflict Management Strategies of Early Childhood Teachers

    ERIC Educational Resources Information Center

    Karakus, Mehmet; Savas, Ahmet Cezmi

    2012-01-01

    In this study it was aimed to determine the effects of parental involvement, teachers' trust in parents and students, and teachers' pupil control ideology on the conflict management strategies used by teachers in classroom management. Data were collected from a sample of 254 teachers through paper and pencil questionnaires. Data were analyzed with…

  5. Effectiveness of semantic therapy for word-finding difficulties in pupils with persistent language impairments: a randomized control trial.

    PubMed

    Ebbels, Susan H; Nicoll, Hilary; Clark, Becky; Eachus, Beth; Gallagher, Aoife L; Horniman, Karen; Jennings, Mary; McEvoy, Kate; Nimmo, Liz; Turner, Gail

    2012-01-01

    Word-finding difficulties (WFDs) in children have been hypothesized to be caused at least partly by poor semantic knowledge. Therefore, improving semantic knowledge should decrease word-finding errors. Previous studies of semantic therapy for WFDs are inconclusive. To investigate the effectiveness of semantic therapy for secondary school-aged pupils with WFDs using a randomized control trial with blind assessment. Fifteen participants with language impairments and WFDs (aged 9;11-15;11) were randomly assigned to a therapy versus waiting control group. In Phase 1 the therapy group received two 15-min semantic therapy sessions per week for 8 weeks with their usual speech and language therapist. Therapy for each participant targeted words from one of three semantic categories (animals, food, clothes). All participants were tested pre- and post-phase 1 therapy on the brief version of the Test of Adolescent Word Finding (TAWF), semantic fluency and the Test of Word Finding in Discourse (TWFD). In Phase 2 the waiting control group received the same therapy as the original therapy group, which received therapy targeted at other language areas. Testing after Phase 2 aimed to establish whether the waiting control group made similar progress to the original therapy group and whether the original therapy group maintained any gains. The original therapy group made significant progress in standard scores on the TAWF (d= 0.94), which was maintained 5 months later. However, they made no progress on the semantic fluency or discourse tests. Participants in the waiting control group did not make significant progress on the TAWF in Phase 1 when they received no word-finding therapy. However, after Phase 2, when they received the therapy, they also made significant progress (d= 0.81). The combined effect of therapy over the two groups was d= 1.2. The mean standard scores on the TAWF were 67 pre-therapy and 77 post-therapy. Four hours of semantic therapy on discrete semantic categories

  6. Transient pupil response is modulated by contrast-based saliency.

    PubMed

    Wang, Chin-An; Boehnke, Susan E; Itti, Laurent; Munoz, Douglas P

    2014-01-08

    The sudden appearance of a novel stimulus in the environment initiates a series of orienting responses that include coordinated shifts of gaze and attention, and also transient changes in pupil size. Although numerous studies have identified a significant effect of stimulus saliency on shifts of gaze and attention, saliency effects on pupil size are less understood. To examine salience-evoked pupil responses, we presented visual, auditory, or audiovisual stimuli while monkeys fixated a central visual spot. Transient pupil dilation was elicited after visual stimulus presentation regardless of target luminance relative to background, and auditory stimuli also evoked similar pupil responses. Importantly, the evoked pupil response was modulated by contrast-based saliency, with faster and larger pupil responses following the presentation of more salient stimuli. The initial transient component of pupil dilation was qualitatively similar to that evoked by weak microstimulation of the midbrain superior colliculus. The pupil responses elicited by audiovisual stimuli were well predicted by a linear summation of each modality response. Together, the results suggest that the transient pupil response, as one component of orienting, is modulated by contrast-based saliency, and the superior colliculus is likely involved in its coordination.

  7. Pupil Diameter Tracks Lapses of Attention

    PubMed Central

    Murphy, Peter R.; Nieuwenhuis, Sander

    2016-01-01

    Our ability to sustain attention for prolonged periods of time is limited. Studies on the relationship between lapses of attention and psychophysiological markers of attentional state, such as pupil diameter, have yielded contradicting results. Here, we investigated the relationship between tonic fluctuations in pupil diameter and performance on a demanding sustained attention task. We found robust linear relationships between baseline pupil diameter and several measures of task performance, suggesting that attentional lapses tended to occur when pupil diameter was small. However, these observations were primarily driven by the joint effects of time-on-task on baseline pupil diameter and task performance. The linear relationships disappeared when we statistically controlled for time-on-task effects and were replaced by consistent inverted U-shaped relationships between baseline pupil diameter and each of the task performance measures, such that most false alarms and the longest and most variable response times occurred when pupil diameter was both relatively small and large. Finally, we observed strong linear relationships between the temporal derivative of pupil diameter and task performance measures, which were largely independent of time-on-task. Our results help to reconcile contradicting findings in the literature on pupil-linked changes in attentional state, and are consistent with the adaptive gain theory of locus coeruleus-norepinephrine function. Moreover, they suggest that the derivative of baseline pupil diameter is a potentially useful psychophysiological marker that could be used in the on-line prediction and prevention of attentional lapses. PMID:27768778

  8. Three-dimensional relationship between high-order root-mean-square wavefront error, pupil diameter, and aging

    PubMed Central

    Applegate, Raymond A.; Donnelly, William J.; Marsack, Jason D.; Koenig, Darren E.; Pesudovs, Konrad

    2007-01-01

    We report root-mean-square (RMS) wavefront error (WFE) for individual aberrations and cumulative high-order (HO) RMS WFE for the normal human eye as a function of age by decade and pupil diameter in 1 mm steps from 3 to 7 mm and determine the relationship among HO RMS WFE, mean age for each decade of life, and luminance for physiologic pupil diameters. Subjects included 146 healthy individuals from 20 to 80 years of age. Ocular aberration was measured on the preferred eye of each subject (for a total of 146 eyes through dilated pupils; computed for 3, 4, 5, 6, and 7 mm pupils; and described with a tenth-radial-order normalized Zernike expansion. We found that HO RMS WFE increases faster with increasing pupil diameter for any given age and pupil diameter than it does with increasing age alone. A planar function accounts for 99% of the variance in the 3-D space defined by mean log HO RMS WFE, mean age for each decade of life, and pupil diameter. When physiologic pupil diameters are used to estimate HO RMS WFE as a function of luminance and age, at low luminance (9 cd/m2) HO RMS WFE decreases with increasing age. This normative data set details (1) the 3-D relationship between HO RMS WFE and age for fixed pupil diameters and (2) the 3-D relationship among HO RMS WFE, age, and luminance for physiologic pupil diameters. PMID:17301847

  9. Duodenal luminal nutrient sensing

    PubMed Central

    Rønnestad, Ivar; Akiba, Yasutada; Kaji, Izumi; Kaunitz, Jonathan D

    2016-01-01

    The gastrointestinal mucosa is exposed to numerous chemical substances and microorganisms, including macronutrients, micronutrients, bacteria, endogenous ions, and proteins. The regulation of mucosal protection, digestion, absorption and motility is signaled in part by luminal solutes. Therefore, luminal chemosensing is an important mechanism enabling the mucosa to monitor luminal conditions, such as pH, ion concentrations, nutrient quantity, and microflora. The duodenal mucosa shares luminal nutrient receptors with lingual taste receptors in order to detect the five basic tastes, in addition to essential nutrients, and unwanted chemicals. The recent ‘de-orphanization’ of nutrient sensing G protein-coupled receptors provides an essential component of the mechanism by which the mucosa senses luminal nutrients. In this review, we will update the mechanisms of and underlying physiological and pathological roles in luminal nutrient sensing, with a main focus on the duodenal mucosa. PMID:25113991

  10. Measuring Pupil Growth in Reading in the More Effective Schools.

    ERIC Educational Resources Information Center

    Forlano, George; Abramson, Jack

    This ESEA/Title I project reports a longitudinal comparison of pupils from 21 More Effective Schools (MES) with pupils from nine control schools in New York City. The Metropolitan Achievement Tests were administered to pupils in grades 2 through 6 in all MES and in selected control schools. Alternate forms were used at initial testing time in…

  11. Time Course of Pupil Center Location after Ocular Drug Application.

    PubMed

    Hoang, Tony A; Macdonnell, Jacqueline E; Mangan, Michelle C; Monsour, Cindy S; Polwattage, Buddhika L; Wilson, Sarah F; Suheimat, Marwan; Atchison, David A

    2016-06-01

    To investigate the time course of pupil centration after application of common topical ocular drugs. Single drops of 2.5% phenylephrine hydrochloride, 1% tropicamide, and 2% pilocarpine hydrochloride were applied on different days to the right eyes of 12 participants. Anterior eye images were captured, at 5-min intervals for an hour, using an infrared-sensitive camera. The images were analyzed to determine pupil diameter and pupil center, the latter with respect to the limbal center. As a control, natural pupil size and pupil center were determined under different illuminances. Pupil centers of natural pupils shifted temporally as pupils dilated. At common pupil sizes, drug-induced pupil centers were different from natural pupil centers. Phenylephrine produced a center shift in the nasal and inferior directions that peaked after a mean of 30 min, whereas dilation was continuing up to 60 min. Tropicamide produced transient center shifts in the nasal and inferior directions that peaked at about 10 min before reducing toward baseline values, whereas dilation reached a peak at about 25 min. Pilocarpine produced a small sustained superior shift that, like constriction, reached a peak after about 25 min. Application of topical ophthalmic drugs cause shifts in pupil center that do not match those produced by natural changes in pupil size and that, in the cases of phenylephrine and tropicamide, follow a different time course than the pupil size changes.

  12. Dietary habits and locus of control assessed in middle-school pupils from the Malopolska region of Poland.

    PubMed

    Gacek, Maria

    2013-01-01

    The formative years of adolescence are a crucial time for developing eating habits which, amongst other factors, are determined by personality traits. The aim of the study was to estimate eating behaviour in a group of middle school pupils according to gender and locus of control (LOC). Subjects were n = 200 boys and n = 200 girls, aged 14-16 living in the Malopolska region of Poland who were surveyed by questionnaire about their eating habits. A standardised Delta questionnaire, by Drwal, was used to assess LOC. Based on the median from the raw LOC scale scores, groups of boys and girls were thereby identified as having high internal (below the median) or high external (above the median) loci of control. The Chi2 test assessed the dependence between LOC and eating habits using PQStat software ver. 1.4.2.324 adopting values of p < 0.05 as beingstatistically significant. Boys were found to consume dairy products significantly more frequently than girls (P < 0.001), and likewise for sugary fizzy drinks (P < 0.05). Dairy products were consumed daily by 51% girls and 70% boys (P < 0.001), whilst fizzy drinks by 32% girls and 43% boys (P < 0.05). Girls with an external LOC consumed breakfast (P < 0.01) and second breakfast (P < 0.001) less regularly, with a less frequent consumption of fruit (P < 0.001) and dairy products (P < 0.01). Boys having an external LOC consumed meals less frequently (P < 0.01), whereas sweets and confectionery products (P < 0.001) and fizzy drinks (P < 0.05) were consumed more often, compared to boys with an internal LOC. Numerous irregularities in diet and differences in certain eating behaviour have been found in middle school students that relate to their gender and LOC. The more rational and appropriate choices were taken by subjects with an internal LOC.

  13. The effect of a school-based intervention on sunbed use in Danish pupils at continuation schools: a cluster-randomized controlled trial.

    PubMed

    Aarestrup, Cecilie; Bonnesen, Camilla T; Thygesen, Lau C; Krarup, Anne F; Waagstein, Anne B; Jensen, Poul D; Bentzen, Joan

    2014-02-01

    To examine the effect of an educational intervention on sunbed use and intentions and attitudes toward sunbed use in 14- to 18-year-olds at continuation schools. We randomized 33 continuation schools either to receive the educational intervention (n = 16) or to be controls (n = 17). Intervention schools received an e-magazine addressing the health risks of sunbed use. Information on behavior and intentions and attitudes toward sunbed use was gathered through self-administrated questionnaires before the intervention and at 6 months as a follow-up. The effect of the intervention was examined by multilevel linear regression and logistic regression. Sunbed use was significantly lower at follow-up among pupils at intervention schools versus pupils at control schools (girls: odds ratio .60, 95% confidence interval .42-.86; Boys: odds ratio .58, 95% confidence interval .35-.96). The intervention had no effect on intention to use sunbeds or attitudes toward sunbed use. The analyses revealed a significant impact of school on attitudes toward sunbed; the intraclass correlation coefficient was estimated to be 6.0% and 7.8% for girls and boys, respectively. The findings from the present study provide new evidence of a positive effect of an educational intervention on sunbed use among pupils aged 14-18 years at continuation schools. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  14. Pupil size reflects the focus of feature-based attention.

    PubMed

    Binda, Paola; Pereverzeva, Maria; Murray, Scott O

    2014-12-15

    We measured pupil size in adult human subjects while they selectively attended to one of two surfaces, bright and dark, defined by coherently moving dots. The two surfaces were presented at the same location; therefore, subjects could select the cued surface only on the basis of its features. With no luminance change in the stimulus, we find that pupil size was smaller when the bright surface was attended and larger when the dark surface was attended: an effect of feature-based (or surface-based) attention. With the same surfaces at nonoverlapping locations, we find a similar effect of spatial attention. The pupil size modulation cannot be accounted for by differences in eye position and by other variables known to affect pupil size such as task difficulty, accommodation, or the mere anticipation (imagery) of bright/dark stimuli. We conclude that pupil size reflects not just luminance or cognitive state, but the interaction between the two: it reflects which luminance level in the visual scene is relevant for the task at hand.

  15. Time-domain analysis for extracting fast-paced pupil responses

    PubMed Central

    Zénon, Alexandre

    2017-01-01

    The eye pupil reacts to cognitive processes, but its analysis is challenging when luminance varies or when stimulation is fast-paced. Current approaches relying on deconvolution techniques do not account for the strong low-frequency spontaneous changes in pupil size or the large interindividual variability in the shape of the responses. Here a system identification framework is proposed in which the pupil responses to different parameters are extracted by means of an autoregressive model with exogenous inputs. In an example application of this technique, pupil size was shown to respond to the luminance and arousal scores of affective pictures presented in rapid succession. This result was significant in each subject (N = 5), but the pupil response varied between individuals both in amplitude and latency, highlighting the need for determining impulse responses subjectwise. The same method was also used to account for pupil size variations caused by respiration, illustrating the possibility to model the relation between pupil size and other continuous signals. In conclusion, this new framework for the analysis of pupil size data allows us to dissociate the response of the eye pupil from intermingled sources of influence and can be used to study the relation between pupil size and other physiological signals. PMID:28134323

  16. Experimental investigations of pupil accommodation factors.

    PubMed

    Lee, Eui Chul; Lee, Ji Woo; Park, Kang Ryoung

    2011-08-17

    PURPOSE. The contraction and dilation of the iris muscle that controls the amount of light entering the retina causes pupil accommodation. In this study, experiments were performed and two of the three factors that influence pupil accommodation were analyzed: lighting conditions and depth fixations. The psychological benefits were not examined, because they could not be quantified. METHODS. A head-wearable eyeglasses-based, eye-capturing device was designed to measure pupil size. It included a near-infrared (NIR) camera and an NIR light-emitting diode. Twenty-four subjects watched two-dimensional (2D) and three-dimensional (3D) stereoscopic videos of the same content, and the changes in pupil size were measured by using the eye-capturing device and image-processing methods: RESULTS. The pupil size changed with the intensity of the videos and the disparities between the left and right images of a 3D stereoscopic video. There was correlation between the pupil size and average intensity. The pupil diameter could be estimated as being contracted from approximately 5.96 to 4.25 mm as the intensity varied from 0 to 255. Further, from the changes in the depth fixation for the pupil accommodation, it was confirmed that the depth fixation also affected accommodation of pupil size. CONCLUSIONS. It was confirmed that the lighting condition was an even more significant factor in pupil accommodation than was depth fixation (significance ratio: approximately 3.2:1) when watching 3D stereoscopic video. Pupil accommodation was more affected by depth fixation in the real world than was the binocular convergence in the 3D stereoscopic display.

  17. Pupil size tracks perceptual content and surprise.

    PubMed

    Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

    2015-04-01

    Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events.

  18. A circuit for pupil orienting responses: implications for cognitive modulation of pupil size.

    PubMed

    Wang, Chin-An; Munoz, Douglas P

    2015-08-01

    Pupil size, as a component of orienting, changes rapidly in response to local salient events in the environment, in addition to its well-known illumination-dependent modulation. Recent research has shown that visual, auditory, or audiovisual stimuli can elicit transient pupil dilation, and the timing and size of the evoked responses are systematically modulated by stimulus salience. Moreover, weak microstimulation of the superior colliculus (SC), a midbrain structure involved in eye movements and attention, evokes similar transient pupil dilation, suggesting that the SC coordinates the orienting response which includes transient pupil dilation. Projections from the SC to the pupil control circuitry provide a novel neural substrate underlying pupil modulation by various cognitive processes.

  19. Pupil size and social vigilance in rhesus macaques

    PubMed Central

    Ebitz, R. Becket; Pearson, John M.; Platt, Michael L.

    2014-01-01

    Complex natural environments favor the dynamic alignment of neural processing between goal-relevant stimuli and conflicting but biologically salient stimuli like social competitors or predators. The biological mechanisms that regulate dynamic changes in vigilance have not been fully elucidated. Arousal systems that ready the body to respond adaptively to threat may contribute to dynamic regulation of vigilance. Under conditions of constant luminance, pupil diameter provides a peripheral index of arousal state. Although pupil size varies with the processing of goal-relevant stimuli, it remains unclear whether pupil size also predicts attention to biologically salient objects and events like social competitors, whose presence interferes with current goals. Here we show that pupil size in rhesus macaques both reflects the biological salience of task-irrelevant social distractors and predicts vigilance for these stimuli. We measured pupil size in monkeys performing a visual orienting task in which distractors—monkey faces and phase-scrambled versions of the same images—could appear in a congruent, incongruent, or neutral position relative to a rewarded target. Baseline pupil size under constant illumination predicted distractor interference, consistent with the hypothesis that pupil-linked arousal mechanisms regulate task engagement and distractibility. Notably, pupil size also predicted enhanced vigilance for social distractors, suggesting that pupil-linked arousal may adjust the balance of processing resources between goal-relevant and biologically important stimuli. The magnitude of pupil constriction in response to distractors closely tracked distractor interference, saccade planning and the social relevance of distractors, endorsing the idea that the pupillary light response is modulated by attention. These findings indicate that pupil size indexes dynamic changes in attention evoked by both the social environment and arousal. PMID:24834026

  20. Binocular luminence interactions due to near responses at suprathreshold conditions: psychophysical evidence

    NASA Astrophysics Data System (ADS)

    Medina, J. M.; Jimenez, J. R.; Del Barco, L. J.; Hita, Enrique

    2001-08-01

    Binocular and monocular finger reaction times were measured for circular broad-band stimuli for natural and artificial pupils. Luminance polarity changes were presented at the fovea respect to a reference stimulus under suprathreshold conditions. As in previous studies, binocular reaction times were shorter than monocular with both pupil types. Nevertheless, this binocular summation effect was less marked with the artificial case, becoming more pronounced for dark variations. These result suggest that the near- responses mechanism at the peristriate area of the occipital and at the inferior parietal lobe could support an important role on luminance interactions within the visuomotor pathway.

  1. The Pupil Premium: Next Steps

    ERIC Educational Resources Information Center

    Sutton Trust, 2015

    2015-01-01

    The pupil premium was introduced by the Coalition government in April 2011 to provide additional funding for disadvantaged pupils. The main difference between the premium and previous funding for disadvantaged pupils is that the premium is linked to individual pupils. On July 1, 2015, The Pupil Premium Summit organized by the Education Endowment…

  2. The Pupil Premium: Next Steps

    ERIC Educational Resources Information Center

    Sutton Trust, 2015

    2015-01-01

    The pupil premium was introduced by the Coalition government in April 2011 to provide additional funding for disadvantaged pupils. The main difference between the premium and previous funding for disadvantaged pupils is that the premium is linked to individual pupils. On July 1, 2015, The Pupil Premium Summit organized by the Education Endowment…

  3. Pupil size influences the eye-tracker signal during saccades.

    PubMed

    Nyström, Marcus; Hooge, Ignace; Andersson, Richard

    2016-04-01

    While it is known that scleral search coils-measuring the rotation of the eye globe--and modern, video based eye trackers-tracking the center of the pupil and the corneal reflection (CR)--produce signals with different properties, the mechanisms behind the differences are less investigated. We measure how the size of the pupil affects the eye-tracker signal recorded during saccades with a common pupil-CR eye-tracker. Eye movements were collected from four healthy participants and one person with an aphakic eye while performing self-paced, horizontal saccades at different levels of screen luminance and hence pupil size. Results show that pupil-, and gaze-signals, but not the CR-signal, are affected by the size of the pupil; changes in saccade peak velocities in the gaze signal of more than 30% were found. It is important to be aware of this pupil size dependent change when comparing fine grained oculomotor behavior across participants and conditions.

  4. Diffractive exit-pupil expander for display applications.

    PubMed

    Urey, H

    2001-11-10

    Two-dimensional binary diffraction gratings can be used in wearable display applications as exit-pupil expanders (EPEs) (or numerical-aperture expanders) to increase the size of the display exit pupil. In retinal scanning displays the EPE is placed at an intermediate image plane between the scanners and the display exit pupil. A focused spot scans across the diffractive EPE and produces multiple diffraction orders at the exit pupil. The overall luminance uniformity across the exit pupil as perceived by the viewer is a function of the uniformity of the diffraction-order intensities, focused-spot size, grating period, scanning-beam profile, and the viewer's eye-pupil size. The design, the diffraction-order uniformity, and the effects of the grating phase angle on the uniformity for binary diffraction gratings are discussed. Also discussed are the display exit-pupil uniformity and the impact of the diffractive EPE on the point-spread function and the modulation transfer function of the display. Both theoretical and experimental results are presented.

  5. Early ERPs to faces: aging, luminance, and individual differences

    PubMed Central

    Bieniek, Magdalena M.; Frei, Luisa S.; Rousselet, Guillaume A.

    2013-01-01

    Recently, Rousselet et al. reported a 1 ms/year delay in visual processing speed in a sample of healthy aged 62 subjects (Frontiers in Psychology 2010, 1:19). Here, we replicate this finding in an independent sample of 59 subjects and investigate the contribution of optical factors (pupil size and luminance) to the age-related slowdown and to individual differences in visual processing speed. We conducted two experiments. In experiment 1 we recorded EEG from subjects aged 18–79. Subjects viewed images of faces and phase scrambled noise textures under nine luminance conditions, ranging from 0.59 to 60.8 cd/m2. We manipulated luminance using neutral density filters. In experiment 2, 10 young subjects (age < 35) viewed similar stimuli through pinholes ranging from 1 to 5 mm. In both experiments, subjects were tested twice. We found a 1 ms/year slowdown in visual processing that was independent of luminance. Aging effects became visible around 125 ms post-stimulus and did not affect the onsets of the face-texture ERP differences. Furthermore, luminance modulated the entire ERP time-course from 60 to 500 ms. Luminance effects peaked in the N170 time window and were independent of age. Importantly, senile miosis and individual differences in pupil size did not account for aging differences and inter-subject variability in processing speed. The pinhole manipulation also failed to match the ERPs of old subjects to those of young subjects. Overall, our results strongly suggest that early ERPs to faces (<200 ms) are delayed by aging and that these delays are of cortical, rather than optical origin. Our results also demonstrate that even late ERPs to faces are modulated by low-level factors. PMID:23717297

  6. An investigation of pupil-based cognitive load measurement with low cost infrared webcam under light reflex interference.

    PubMed

    Chen, Siyuan; Epps, Julien; Chen, Fang

    2013-01-01

    Using the task-evoked pupillary response (TEPR) to index cognitive load can contribute significantly to the assessment of memory function and cognitive skills in patients. However, the measurement of pupillary response is currently limited to a well-controlled lab environment due to light reflex and also relies heavily on expensive video-based eye trackers. Furthermore, commercial eye trackers are usually dedicated to gaze direction measurement, and their calibration procedure and computing resource are largely redundant for pupil-based cognitive load measurement (PCLM). In this study, we investigate the validity of cognitive load measurement with (i) pupil light reflex in a less controlled luminance background; (ii) a low-cost infrared (IR) webcam for the TEPR in a controlled luminance background. ANOVA results show that with an appropriate baseline selection and subtraction, the light reflex is significantly reduced, suggesting the possibility of less constrained practical applications of PCLM. Compared with the TEPR from a commercial remote eye tracker, a low-cost IR webcam achieved a similar TEPR pattern and no significant difference was found between the two devices in terms of cognitive load measurement across five induced load levels.

  7. Integrating Physically Handicapped Pupils.

    ERIC Educational Resources Information Center

    Hodgson, Ann

    1984-01-01

    Intended for regular class teachers working with mainstreamed physically handicapped pupils, the article offers guidelines regarding school organization, conditions directly affecting the pupil, and classroom considerations. A brief review of the major conditions (such as allergies, cerebral palsy, and muscular dystrophy) is presented. (CL)

  8. Integrating Physically Handicapped Pupils.

    ERIC Educational Resources Information Center

    Hodgson, Ann

    1984-01-01

    Intended for regular class teachers working with mainstreamed physically handicapped pupils, the article offers guidelines regarding school organization, conditions directly affecting the pupil, and classroom considerations. A brief review of the major conditions (such as allergies, cerebral palsy, and muscular dystrophy) is presented. (CL)

  9. Assessing Pupils' Progress

    ERIC Educational Resources Information Center

    Ollerton, Mike

    2010-01-01

    In this article, the author explores what Assessing Pupils' Progress (APP) is about. He contends that the predilection for testing is a catastrophe as far as the teaching and learning of mathematics is concerned; it is an outcome of the drive for collecting so-called "data" on pupils. What those people, who should know better, either choose to…

  10. Creating Pupils' Internet Magazine

    ERIC Educational Resources Information Center

    Bognar, Branko; Šimic, Vesna

    2014-01-01

    This article presents an action research, which aimed to improve pupils' literary creativity and enable them to use computers connected to the internet. The study was conducted in a small district village school in Croatia. Creating a pupils' internet magazine appeared to be an excellent way for achieving the educational aims of almost all…

  11. Pupil Alignment Considerations for Large, Deployable Space Telescopes

    NASA Technical Reports Server (NTRS)

    Bos, Brent J.; Ohl, Raymond G.; Kubalak, Daivd A.

    2011-01-01

    For many optical systems the properties and alignment of the internal apertures and pupils are not critical or controlled with high precision during optical system design, fabrication or assembly. In wide angle imaging systems, for instance, the entrance pupil position and orientation is typically unconstrained and varies over the system s field of view in order to optimize image quality. Aperture tolerances usually do not receive the same amount of scrutiny as optical surface aberrations or throughput characteristics because performance degradation is typically graceful with misalignment, generally only causing a slight reduction in system sensitivity due to vignetting. But for a large deployable space-based observatory like the James Webb Space Telescope (JWST), we have found that pupil alignment is a key parameter. For in addition to vignetting, JWST pupil errors cause uncertainty in the wavefront sensing process that is used to construct the observatory on-orbit. Furthermore they also open stray light paths that degrade the science return from some of the telescope s instrument channels. In response to these consequences, we have developed several pupil measurement techniques for the cryogenic vacuum test where JWST science instrument pupil alignment is verified. These approaches use pupil alignment references within the JWST science instruments; pupil imaging lenses in three science instrument channels; and unique pupil characterization features in the optical test equipment. This will allow us to verify and crosscheck the lateral pupil alignment of the JWST science instruments to approximately 1-2% of their pupil diameters.

  12. THE TOTAL LUMINOUS EFFICIENCY OF LUMINOUS BACTERIA

    PubMed Central

    Harvey, E. Newton

    1925-01-01

    Methods are described for measuring the light emitted by an emulsion of luminous bacteria of given thickness, and calculating the light emitted by a single bacterium, measuring 1.1 x 2.2 micra, provided there is no absorption of light in the emulsion. At the same time, the oxygen consumed by a single bacterium was measured by recording the time for the bacteria to use up .9 of the oxygen dissolved in sea water from air (20 per cent oxygen). The luminescence intensity does not diminish until the oxygen concentration falls below 2 per cent, when the luminescence diminishes rapidly. Above 2 per cent oxygen (when the oxygen dissolving in sea water from pure oxygen at 760 mm. Hg pressure = 100 per cent) the bacteria use equal amounts of oxygen in equal times, while below 2 per cent oxygen it seems very likely that rate of oxygen absorption is proportional to oxygen concentration. By measuring the time for a tube of luminous bacteria of known concentration saturated with air (20 per cent oxygen) to begin to darken (2 per cent oxygen) we can calculate the oxygen absorbed by one bacterium per second. The bacteria per cc. are counted on a blood counting slide or by a centrifugal method, after measuring the volume of a single bacterium (1.695 x 10–12 cc.). Both methods gave results in good agreement with each other. The maximum value for the light from a single bacterium was 24 x 10–14 lumens or 1.9 x 10–14 candles. The maximum value for lumen-seconds per mg. of oxygen absorbed was 14. The average value for lumen-seconds per mg. O2 was 9.25. The maximum values were selected in calculating the efficiency of light production, since some of the bacteria counted may not be producing light, although they may still be using oxygen. The "diet" of the bacteria was 60 per cent glycerol and 40 per cent peptone. To oxidize this mixture each mg. of oxygen would yield 3.38 gm. calories or 14.1 watts per second. 1 lumen per watt is therefore produced by a normal bacterium which

  13. On the necessity of correcting peripheral target luminance for pupillary area

    SciTech Connect

    Bedell, H.E.; Katz, L.M.

    1982-10-01

    Despite the decrease in pupillary area for peripheral targets, retinal illuminance remains fairly constant to about 80 deg visual angle. Constant illuminance is maintained in the retinal periphery because the light that enters the pupil is concentrated into smaller retinal images. The correction of the peripheral target luminances for pupillary area is therefore unnecessary except under certain conditions.

  14. Change in dynamic visual acuity (DVA) by pupil dilation.

    PubMed

    Ueda, Tetsuo; Nawa, Yoshiaki; Yukawa, Eiichi; Taketani, Futoshi; Hara, Yoshiaki

    2006-01-01

    This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation. Pupil dilation may negatively affect driving performance. Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time. In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p < .01) but returned to the predilation level at 360 min (ANOVA; p = .61). Pupil size changed from 4.1 to 7.8 mm (ANOVA; p < .01) at 30 min after the instillation, and this level was maintained up to 120 min but returned to normal within 360 min. In the control group, DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly (p < .05) correlated with the pupil size at all measured times. The improvement in DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA. Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance.

  15. Interaction of aberrations, diffraction, and quantal fluctuations determine the impact of pupil size on visual quality.

    PubMed

    Xu, Renfeng; Wang, Huachun; Thibos, Larry N; Bradley, Arthur

    2017-04-01

    Our purpose is to develop a computational approach that jointly assesses the impact of stimulus luminance and pupil size on visual quality. We compared traditional optical measures of image quality and those that incorporate the impact of retinal illuminance dependent neural contrast sensitivity. Visually weighted image quality was calculated for a presbyopic model eye with representative levels of chromatic and monochromatic aberrations as pupil diameter was varied from 7 to 1 mm, stimulus luminance varied from 2000 to 0.1  cd/m2, and defocus varied from 0 to -2 diopters. The model included the effects of quantal fluctuations on neural contrast sensitivity. We tested the model's predictions for five cycles per degree gratings by measuring contrast sensitivity at 5  cyc/deg. Unlike the traditional Strehl ratio and the visually weighted area under the modulation transfer function, the visual Strehl ratio derived from the optical transfer function was able to capture the combined impact of optics and quantal noise on visual quality. In a well-focused eye, provided retinal illuminance is held constant as pupil size varies, visual image quality scales approximately as the square root of illuminance because of quantum fluctuations, but optimum pupil size is essentially independent of retinal illuminance and quantum fluctuations. Conversely, when stimulus luminance is held constant (and therefore illuminance varies with pupil size), optimum pupil size increases as luminance decreases, thereby compensating partially for increased quantum fluctuations. However, in the presence of -1 and -2 diopters of defocus and at high photopic levels where Weber's law operates, optical aberrations and diffraction dominate image quality and pupil optimization. Similar behavior was observed in human observers viewing sinusoidal gratings. Optimum pupil size increases as stimulus luminance drops for the well-focused eye, and the benefits of small pupils for improving

  16. Pupils' Understanding of Air Pollution

    ERIC Educational Resources Information Center

    Dimitriou, Anastasia; Christidou, Vasilia

    2007-01-01

    This paper reports on a study of pupils' knowledge and understanding of atmospheric pollution. Specifically, the study is aimed at identifying: 1) the extent to which pupils conceptualise the term "air pollution" in a scientifically appropriate way; 2) pupils' knowledge of air pollution sources and air pollutants; and 3) pupils'…

  17. Pupils' Understanding of Air Pollution

    ERIC Educational Resources Information Center

    Dimitriou, Anastasia; Christidou, Vasilia

    2007-01-01

    This paper reports on a study of pupils' knowledge and understanding of atmospheric pollution. Specifically, the study is aimed at identifying: 1) the extent to which pupils conceptualise the term "air pollution" in a scientifically appropriate way; 2) pupils' knowledge of air pollution sources and air pollutants; and 3) pupils'…

  18. Changes in the objective amplitude of accommodation with pupil size.

    PubMed

    Lara, Francisco; Bernal-Molina, Paula; Fernández-Sánchez, Vicente; López-Gil, Norberto

    2014-10-01

    We evaluate the effect of pupil size on objectively measured amplitude of accommodation (AA). Pupil diameter and wavefront aberrometry were obtained in 15 eyes when stimulus swept across the range of clear vision in steps of 0.5 diopters. Wavefront refraction techniques were used to compute objective AA as the maximum refractive change. Measurements were obtained monocularly under low and high ambient room lighting conditions with a fixed luminance of the fixation target. Amplitude of accommodation computations were performed taking into account just paraxial rays (paraxial AA) or including the effects of the change of spherical aberration during accommodation (minRMS AA). Mean pupil size values at low light level were 6.26 mm (relaxed) and 4.15 mm (maximum accommodation), whereas at the high light level, those values became 4.74 and 3.04 mm, respectively. The effects of both light level on accommodation were significant (p < 0.001), and accommodative miosis was slightly larger at low light levels. Mean minRMS and paraxial AA were always greater by more than 1 diopter in high than in low ambient lighting conditions (p < 0.01), indicating a significant impact of pupil size on AA. The influence of the ambient lighting on the objective AA is not only attributed to the increased effects of spherical aberration as the pupil dilates but mostly attributed to a decrease in the paraxial accommodation as pupil dilates.

  19. Pupil responses to high-level image content.

    PubMed

    Naber, Marnix; Nakayama, Ken

    2013-05-17

    The link between arousal and pupil dilation is well studied, but it is less known that other cognitive processes can trigger pupil responses. Here we present evidence that pupil responses can be induced by high-level scene processing, independent of changes in low-level features or arousal. In Experiment 1, we recorded changes in pupil diameter of observers while they viewed a variety of natural scenes with or without a sun that were presented either upright or inverted. Image inversion had the strongest effect on the pupil responses. The pupil constricted more to the onset of upright images as compared to inverted images. Furthermore, the amplitudes of pupil constrictions to viewing images containing a sun were larger relative to control images. In Experiment 2, we presented cartoon versions of upright and inverted pictures that included either a sun or a moon. The image backgrounds were kept identical across conditions. Similar to Experiment 1, upright images triggered pupil constrictions with larger amplitudes than inverted images and images of the sun evoked greater pupil contraction than images of the moon. We suggest that the modulations of pupil responses were due to higher-level interpretations of image content.

  20. Explaining the link among self-controlling and children parenting techniques and mental insurance of high school pupils

    PubMed Central

    Sekhavati, E; Rahimian Boogar, M; Khodadost, M; Afkari, R; Atefeh, Raoufi

    2015-01-01

    Introduction: One of the wellness estimation axes of various communities are the mental well-being of the communities. Health means an attempt to Self-actualization and development that exhibit in the adaptation of person's skills and experiences. No doubt mental health plays a major role in assuring efficiency in any organization and can be affected via different parameters. Accordingly, the current research conducted by the purpose of illustrating the relationship among self-managing and kid parenting techniques and mental health amongst high school pupils of Abadeh Town. Methodology: In this sectional-correlation research, 375 pupils are taken and involved in the research in stage group sampling technique of Abadeh high schools. Tangney’s self-managing survey, Barry's kid parenting rate, Reef’s mental survey and a framework of demographic data utilized to obtain data. Information investigated utilizing software SPSS 19 or Pearson’s relationship coefficient analysis and stepwise multivariable regression investigation. Findings: Information investigation depicts self-managing parameter has a great and opposite predictability regarding mental health parameter (t =0.003, = β-0.158, P=2.99). Therefore self-managing has great and opposite predictability regarding 2 parts of mental health rate i.e. self-approval (P= 0.0001, t=4.87, β= - 0.181) and dominance on conditions (P= 0.0001, t=3.807, β= - 0.200). The decisions represent the proximity of a consequence relationship among predictability of kid parenting techniques regarding mental health (p=0.01, F=3.85, r2= 0.031, r=0.177). These sequences reveal great predictability of kid parenting styles in 2 various ways in 2 methods of grinding (P=0.035, t= 2.12, β=0.113) and standard (P=0.014, t=2.437, β= 0.434). The Severe method has a reversed important connection in maximum features of mental health. Furthermore, they note that "authoritative method" parameter just has prediction capacity 0.143 based on mental

  1. Explaining the link among self-controlling and children parenting techniques and mental insurance of high school pupils.

    PubMed

    Sekhavati, E; Rahimian Boogar, M; Khodadost, M; Afkari, R; Atefeh, Raoufi

    2015-01-01

    Introduction: One of the wellness estimation axes of various communities are the mental well-being of the communities. Health means an attempt to Self-actualization and development that exhibit in the adaptation of person's skills and experiences. No doubt mental health plays a major role in assuring efficiency in any organization and can be affected via different parameters. Accordingly, the current research conducted by the purpose of illustrating the relationship among self-managing and kid parenting techniques and mental health amongst high school pupils of Abadeh Town. Methodology: In this sectional-correlation research, 375 pupils are taken and involved in the research in stage group sampling technique of Abadeh high schools. Tangney's self-managing survey, Barry's kid parenting rate, Reef's mental survey and a framework of demographic data utilized to obtain data. Information investigated utilizing software SPSS 19 or Pearson's relationship coefficient analysis and stepwise multivariable regression investigation. Findings: Information investigation depicts self-managing parameter has a great and opposite predictability regarding mental health parameter (t =0.003, = β-0.158, P=2.99). Therefore self-managing has great and opposite predictability regarding 2 parts of mental health rate i.e. self-approval (P= 0.0001, t=4.87, β= - 0.181) and dominance on conditions (P= 0.0001, t=3.807, β= - 0.200). The decisions represent the proximity of a consequence relationship among predictability of kid parenting techniques regarding mental health (p=0.01, F=3.85, r2= 0.031, r=0.177). These sequences reveal great predictability of kid parenting styles in 2 various ways in 2 methods of grinding (P=0.035, t= 2.12, β=0.113) and standard (P=0.014, t=2.437, β= 0.434). The Severe method has a reversed important connection in maximum features of mental health. Furthermore, they note that "authoritative method" parameter just has prediction capacity 0.143 based on mental

  2. Luminous pulses during triggered lightning

    NASA Astrophysics Data System (ADS)

    Winn, W. P.; Eastvedt, E. M.; Trueblood, J. J.; Eack, K. B.; Edens, H. E.; Aulich, G. D.; Hunyady, S. J.; Murray, W. C.

    2012-05-01

    A triggered lightning flash that transferred negative charge to ground in central New Mexico produced more than three levels of branching above the main channel to ground in a 1 km vertical field of view. A high-speed video recording shows that the main channel had about 50 brief luminous pulses, many of which were superimposed on a slowly changing persistent luminosity. In contrast, superposition was rare in the uppermost visible branches because luminous pulses first appeared on preexisting dark channels before merging into a luminous channel. This observation suggests that luminous pulses in triggered and natural lightning originate only on dark branches and that the complexity of the main channel to ground is the result of multiple mergers of dark branches with pulses into luminous branches without pulses. This suggestion is contrary to an earlier conclusion that there are two kinds of luminous pulses. We also observe behavior characteristic of electromagnetic waves on transmission lines: when a downward propagating luminous pulse reaches a junction with another initially dark branch, it travels both upward and downward along that branch. Upon reaching the ground the downward propagating wave produces a bright reflection which also splits at the junctions, producing luminosity for a short distance upward in one direction while propagating much farther upward along the path charged by the downward propagating wave. However, when a downward moving luminous pulse reaches a junction with an initially luminous branch, splitting is not evident, probably due to the greater conductivity of the luminous channel.

  3. Anisoplanatism in adaptive optics systems due to pupil aberrations

    SciTech Connect

    Bauman, B

    2005-08-01

    Adaptive optics systems typically include an optical relay that simultaneously images the science field to be corrected and also a set of pupil planes conjugate to the deformable mirror of the system. Often, in the optical spaces where DM's are placed, the pupils are aberrated, leading to a displacement and/or distortion of the pupil that varies according to field position--producing a type of anisoplanatism, i.e., a degradation of the AO correction with field angle. The pupil aberration phenomenon is described and expressed in terms of Seidel aberrations. An expression for anisoplanatism as a function of pupil distortion is derived, an example of an off-axis parabola is given, and a convenient method for controlling pupil-aberration-generated anisoplanatism is proposed.

  4. Promoting prosocial pupil behaviour: 2-secondary school intervention and pupil effects.

    PubMed

    Mooij, T

    1999-12-01

    In an earlier article (Mooij, 1999c) a theoretical multilevel model to promote prosocial pupil behaviour by stimulating specific educational conditions was developed. To carry out school interventions to check empirically whether pupil level effects occur because of educational changes at the classroom and school level. Seven secondary schools with relatively high degrees of pupil aggression were selected. Four schools took part as intervention schools, three schools served as control schools. In 1995 (pretest) and 1997 (post-test) pupils and form teachers of the first and third school years participated by completing questionnaires. Within the pupil cohorts, a longitudinal group of 352 pupils was included. Pretest questionnaires in 1995 were followed by intervention in the intervention schools. Teachers collaborated with staff and researchers to increase pupils' participation and responsibility in specifying and controlling behavioural and didactic rules, related to didactic differentiation during lessons. The validity of the intervention implementation was checked using qualitative information and quantitative data from both pre- and post-test. Longitudinal intervention effects were tested by applying two-level multiple regression analyses. After controlling for pretest and covariables in school year 1, school intervention effects were found in school year 3 with the prediction of being a perpetrator of aggressive behaviour at school, aggressive behaviour outside school, and criminal behaviour. Some small effects were found with respect to victim behaviour. Social-pedagogical and didactic class and school variables, but also home variables and support by peers without problematic behaviour, could be integrated more systematically to promote prosocial development of a pupil's behaviour from the beginning in school.

  5. Pupil Transportation Guide: Cost Analysis, Service Options, and Contract Administration.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    Designed to help school administrators improve the efficiency of pupil transportation programs and control costs, this guide provides detailed guidance on how to collect and analyze costs, assess the effects of service levels and policies, and develop and administer a pupil transportation contract. Following an introductory chapter, part I…

  6. Results of a Survey of Pupils and Teachers Regarding Television.

    ERIC Educational Resources Information Center

    Crawford, Patricia; Rapoport, Max

    To test the validity of hypotheses regarding television violence and social behavior of viewers, a survey was conducted of a large stratified sample of sixth grade and kindergarten pupils and of teachers. The student survey identified: (1) frequency with which pupils watch television; (2) parental control of television viewing; (3) family…

  7. How Greek Teachers Perceive School Functioning of Pupils with ADHD

    ERIC Educational Resources Information Center

    Kakouros, Efthymios; Maniadaki, Katerina; Papaeliou, Christina

    2004-01-01

    In this study Greek teachers assessed school functioning in 26 pupils with the possibility of attention deficit hyperactivity disorder (ADHD) subtypes, i.e. combined (C) type, inattentive (IA) type and hyperactive-impulsive (HI) type, and 26 controls. Results showed that C and IA pupils were evaluated as impaired in all areas of academic and…

  8. Faith Schools and Pupils' Progress through Primary Education

    ERIC Educational Resources Information Center

    Yeshanew, Tilaye; Schagen, Ian; Evans, Suzanne

    2008-01-01

    The impact of faith schools on the performance and progress of their pupils has been studied using data from the National Pupil Database (NPD). The value-added analysis was carried out using multilevel modelling, controlling for prior attainment as well as a range of background variables, including ethnicity, sex, eligibility for free school meals…

  9. Pupil densification: a panorama

    NASA Astrophysics Data System (ADS)

    Martinache, F.; Lardière, O.

    The technique of pupil densification bridges the gap existing between conventionnal optical astronomy observing techniques and optical interferometry: it indeed leads to the concept of hypertelescope: an instrument that can provide direct images at the focus of an interferometer. The hypertelescope is the open sesame for high dynamic imaging with an interferometer: indeed, the elementary remapping of the pupil operated by a densifier not only maximizes the dynamic range and the signal to noise ratio of images but also makes the interferometer compatible with most existing coronagraphic devices. Moreover, a careful discussion about field of view show that for a diluted array, the pupil densification preserves all the relevant high angular resolution information collected by the interferometer and therefore induces no field loss.

  10. Chromatic pupil responses: preferential activation of the melanopsin-mediated versus outer photoreceptor-mediated pupil light reflex.

    PubMed

    Kardon, Randy; Anderson, Susan C; Damarjian, Tina G; Grace, Elizabeth M; Stone, Edwin; Kawasaki, Aki

    2009-08-01

    To weight the rod-, cone-, and melanopsin-mediated activation of the retinal ganglion cells, which drive the pupil light reflex by varying the light stimulus wavelength, intensity, and duration. Experimental study. Forty-three subjects with normal eyes and 3 patients with neuroretinal visual loss. A novel stimulus paradigm was developed using either a long wavelength (red) or short wavelength (blue) light given as a continuous Ganzfeld stimulus with stepwise increases over a 2 log-unit range. The pupillary movement before, during, and after the light stimulus was recorded in real time with an infrared illuminated video camera. The percent pupil contraction of the transient and sustained pupil response to a low- (1 cd/m(2)), medium- (10 cd/m(2)), and high-intensity (100 cd/m(2)) red- and blue-light stimulus was calculated for 1 eye of each subject. From the 43 normal eyes, median and 25th, 75th, 5th, and 95th percentile values were obtained for each stimulus condition. In normal eyes at lower intensities, blue light evoked much greater pupil responses compared with red light when matched for photopic luminance. The transient pupil contraction was generally greater than the sustained contraction, and this disparity was greatest at the lowest light intensity and least apparent with bright (100 cd/m(2)) blue light. A patient with primarily rod dysfunction (nonrecordable scotopic electroretinogram) showed significantly reduced pupil responses to blue light at lower intensities. A patient with achromatopsia and an almost normal visual field showed selective reduction of the pupil response to red-light stimulation. A patient with ganglion cell dysfunction owing to anterior ischemic optic neuropathy demonstrated global loss of pupil responses to red and blue light in the affected eye. Pupil responses that differ as a function of light intensity and wavelength support the hypothesis that selected stimulus conditions can produce pupil responses that reflect phototransduction

  11. Lidar Luminance Quantizer

    NASA Technical Reports Server (NTRS)

    Quilligan, Gerard; DeMonthier, Jeffrey; Suarez, George

    2011-01-01

    This innovation addresses challenges in lidar imaging, particularly with the detection scheme and the shapes of the detected signals. Ideally, the echoed pulse widths should be extremely narrow to resolve fine detail at high event rates. However, narrow pulses require wideband detection circuitry with increased power dissipation to minimize thermal noise. Filtering is also required to shape each received signal into a form suitable for processing by a constant fraction discriminator (CFD) followed by a time-to-digital converter (TDC). As the intervals between the echoes decrease, the finite bandwidth of the shaping circuits blends the pulses into an analog signal (luminance) with multiple modes, reducing the ability of the CFD to discriminate individual events

  12. A pupil size response model to assess fear learning.

    PubMed

    Korn, Christoph W; Staib, Matthias; Tzovara, Athina; Castegnetti, Giuseppe; Bach, Dominik R

    2017-03-01

    During fear conditioning, pupil size responses dissociate between conditioned stimuli that are contingently paired (CS+) with an aversive unconditioned stimulus, and those that are unpaired (CS-). Current approaches to assess fear learning from pupil responses rely on ad hoc specifications. Here, we sought to develop a psychophysiological model (PsPM) in which pupil responses are characterized by response functions within the framework of a linear time-invariant system. This PsPM can be written as a general linear model, which is inverted to yield amplitude estimates of the eliciting process in the central nervous system. We first characterized fear-conditioned pupil size responses based on an experiment with auditory CS. PsPM-based parameter estimates distinguished CS+/CS- better than, or on par with, two commonly used methods (peak scoring, area under the curve). We validated this PsPM in four independent experiments with auditory, visual, and somatosensory CS, as well as short (3.5 s) and medium (6 s) CS/US intervals. Overall, the new PsPM provided equal or decisively better differentiation of CS+/CS- than the two alternative methods and was never decisively worse. We further compared pupil responses with concurrently measured skin conductance and heart period responses. Finally, we used our previously developed luminance-related pupil responses to infer the timing of the likely neural input into the pupillary system. Overall, we establish a new PsPM to assess fear conditioning based on pupil responses. The model has a potential to provide higher statistical sensitivity, can be applied to other conditioning paradigms in humans, and may be easily extended to nonhuman mammals.

  13. Smaller pupil size and better proofreading performance with positive than with negative polarity displays.

    PubMed

    Piepenbrock, Cosima; Mayr, Susanne; Buchner, Axel

    2014-01-01

    The 'positive polarity advantage' describes the fact that reading performance is better for dark text on light background (positive polarity) than for light text on dark background (negative polarity). We investigated the underlying mechanism by assessing pupil size and proofreading performance when reading positive and negative polarity texts. In particular, we tested the display luminance hypothesis which postulates that the typically greater brightness of positive compared to negative polarity displays leads to smaller pupil sizes and, hence, a sharper retinal image and better perception of detail. Indeed, pupil sizes were smaller and proofreading performance was better with positive than with negative polarity displays. The results are compatible with the hypothesis that the positive polarity advantage is an effect of display luminance. Limitations of the study are being discussed.

  14. Teacher Development and Pupil Voice

    ERIC Educational Resources Information Center

    Flutter, Julia

    2007-01-01

    The principle of "pupil voice" has attained a high profile over the past decade and its key principles of encouraging pupil consultation and participation are evident in official policy and guidance in many countries around the world. While there has been official endorsement of the notions that pupils have a right to voice their…

  15. Learning a Musical Instrument: The Influence of Interpersonal Interaction on Outcomes for School-Aged Pupils

    ERIC Educational Resources Information Center

    Creech, Andrea; Hallam, Susan

    2011-01-01

    Researchers in recent years have increasingly placed an emphasis on seeking pupils' perceptions of educational settings. Alongside this shift towards attaching value to the pupil viewpoint has been a growing interest concerning how interpersonal relationships, manifested as control or responsiveness between teachers and pupils or parents and…

  16. Cryogenic Pupil Alignment Test Architecture for Aberrated Pupil Images

    NASA Technical Reports Server (NTRS)

    Bos, Brent; Kubalak, David A.; Antonille, Scott; Ohl, Raymond; Hagopian, John G.

    2009-01-01

    A document describes cryogenic test architecture for the James Webb Space Telescope (JWST) integrated science instrument module (ISIM). The ISIM element primarily consists of a mechanical metering structure, three science instruments, and a fine guidance sensor. One of the critical optomechanical alignments is the co-registration of the optical telescope element (OTE) exit pupil with the entrance pupils of the ISIM instruments. The test architecture has been developed to verify that the ISIM element will be properly aligned with the nominal OTE exit pupil when the two elements come together. The architecture measures three of the most critical pupil degrees-of-freedom during optical testing of the ISIM element. The pupil measurement scheme makes use of specularly reflective pupil alignment references located inside the JWST instruments, ground support equipment that contains a pupil imaging module, an OTE simulator, and pupil viewing channels in two of the JWST flight instruments. Pupil alignment references (PARs) are introduced into the instrument, and their reflections are checked using the instrument's mirrors. After the pupil imaging module (PIM) captures a reflected PAR image, the image will be analyzed to determine the relative alignment offset. The instrument pupil alignment preferences are specularly reflective mirrors with non-reflective fiducials, which makes the test architecture feasible. The instrument channels have fairly large fields of view, allowing PAR tip/tilt tolerances on the order of 0.5deg.

  17. Pupil diameter reflects uncertainty in attentional selection during visual search

    PubMed Central

    Geng, Joy J.; Blumenfeld, Zachary; Tyson, Terence L.; Minzenberg, Michael J.

    2015-01-01

    Pupil diameter has long been used as a metric of cognitive processing. However, recent advances suggest that the cognitive sources of change in pupil size may reflect LC-NE function and the calculation of unexpected uncertainty in decision processes (Aston-Jones and Cohen, 2005; Yu and Dayan, 2005). In the current experiments, we explored the role of uncertainty in attentional selection on task-evoked changes in pupil diameter during visual search. We found that task-evoked changes in pupil diameter were related to uncertainty during attentional selection as measured by reaction time (RT) and performance accuracy (Experiments 1-2). Control analyses demonstrated that the results are unlikely to be due to error monitoring or response uncertainty. Our results suggest that pupil diameter can be used as an implicit metric of uncertainty in ongoing attentional selection requiring effortful control processes. PMID:26300759

  18. Speaking and the Pupil.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Speaking activities should be stressed along with reading experiences in teaching-learning situations. It is important for learners to develop needed skills in reporting to others in a group setting. The teacher and the pupils in the classroom should support each other so that satisfying experiences in oral communication are an end result.…

  19. Disorders of the pupil.

    PubMed

    Wilhelm, Helmut

    2011-01-01

    Pupil size is determined by the interaction of the parasympathetic and the sympathetic nervous system. The parasympathetic system conducts the light reaction with its major center in the dorsal midbrain. The sympathetic nervous system acts either directly on the dilator muscle (peripherally) or centrally by inhibiting the Edinger-Westphal nucleus. Psychosensory reactions are transmitted via the sympathetic system. The afferent input of the light reflex system in humans is characteristically wired, allowing a detailed analysis of a lesion of the afferent input. Even in humans a subgroup of ganglion cells containing melansopsin plays an important role as a light sensor for the pupillary system. To diagnose normal pupillary function, pupils need to be isocoric and react bilaterally equally to light. Anisocoria indicates a problem of the efferent pupillary pathway. Pupillary disorders may involve the afferent pathways (relative afferent pupillary defect) or the efferent pathways. Physiological anisocoria is a harmless condition that has to be distinguished from Horner's syndrome. In this case pharmacological testing with cocaine eye-drops is helpful. Disorders of the parasympathetic system will impair the light response. They include dorsal midbrain syndrome, third-nerve palsy, and tonic pupil. Tonic pupils are mainly idiopathic and do not need imaging. Disorders of the iris, including application of cholinergic agents, need also to be considered in impaired pupillary light reaction.

  20. Pupil Transportation Management.

    ERIC Educational Resources Information Center

    Miller, Anthony R.

    The safest means of transportation in the United States is the school bus fleet. Each school day, over 350,000 school buses transport about 22,000,000 children ages 3 to 21--from wheelchair pupils to varsity football players--to and from school in weather conditions ranging from those for Fairbanks, Alaska, to those typical of Cave Creek, Arizona.…

  1. The Pupil Appraisal Center.

    ERIC Educational Resources Information Center

    Wilborn, Bobbie; Gentile, Lance M.

    The primary purpose of the Pupil Appraisal Center (PAC) is to promote teacher education by providing teachers and students direct experience in resolving behavioral disorders and learning problems. PAC provides specialized teacher training in counseling, reading, hearing, speech, and language development and provides service to area schools for…

  2. Speaking: Pupil Competencies.

    ERIC Educational Resources Information Center

    Levin, Beatrice J.; And Others

    To ensure that all of the subskills undergirding pupils' speaking are identified, taught, and reinforced, the School District of Philadelphia prepared hierarchical listings of skills as exemplified in specific student behaviors. The structured sequence of oral language behaviors are stated operationally and are identified at 14 levels in terms of…

  3. Pupil Transportation Management.

    ERIC Educational Resources Information Center

    Miller, Anthony R.

    The safest means of transportation in the United States is the school bus fleet. Each school day, over 350,000 school buses transport about 22,000,000 children ages 3 to 21--from wheelchair pupils to varsity football players--to and from school in weather conditions ranging from those for Fairbanks, Alaska, to those typical of Cave Creek, Arizona.…

  4. Autonomous Work by Pupils.

    ERIC Educational Resources Information Center

    Marbeau, V.

    This monograph is a report on an international discussion of the desirability of autonomous work on the part of students. The rationale for autonomous work is twofold. First, this approach should lead the pupil to think about the learning process and take an active and responsible share in it. This will promote the development of personality by…

  5. Pupil Evaluation Team Handbook.

    ERIC Educational Resources Information Center

    Glass, Ray; And Others

    This handbook is designed to assist educators in Maine to implement the Pupil Evaluation Team (PET) process. PET is described as a group composed of parents, school professionals, and representatives of agencies responsible for determining special education needs of exceptional students. Chapters deal with: (1) the role of the PET chairperson…

  6. Relationships for Learning: Using Pupil Voice to Define Teacher-Pupil Relationships that Enhance Pupil Engagement

    ERIC Educational Resources Information Center

    Marsh, Helena

    2012-01-01

    This paper is a summary of a pupil voice research project conducted to investigate the influence that teacher-pupil relationships have on pupils' feelings of engagement with their school. The study involved two year groups (12-13 and 14-15 year olds) in a rural secondary school in Cambridgeshire. Data sources were collected through a questionnaire…

  7. Make pupils young researchers!

    NASA Astrophysics Data System (ADS)

    Gouhier, Armelle

    2015-04-01

    With the 2011 educational reform in France, a new course has been created in secondary schools : Methods & Practices in Science (MPS). The main goal was to improve the pupils working methods in science, including laboratory and field works. In addition, the pedagogy develops pupils autonomy and creativity, a key factor in a research process. Three teachers are working together (Mathematics, Physics and Geology-Biology), showing how different disciplines complement one another. Eventually, this is aimed at attracting more students in scientific sections. This course is optional, in the "seconde" class in French secondary schools (i.e., for 15 years old students). For the next class, they will have to choose between scientific, economic and literature sections : it is a useful option for them to decide which section has their preference. In my high-school in Clermont-Ferrand, we have chosen a research subject on hydrogeology & water quality improvement in region "Auvergne". The pupils will have to develop and set up appropriate tools to check and improve the water quality, related to different disciplines : - Geology & Biology: hydrogeology, effects of different pollutants on aquatic life, solutions to improve water quality (example of the natural water treatment zone in the lake of "Aydat, Auvergne, France"). - Physics & Chemistry: water potability criteria, pollution tests in water, water treatment plants working. - Mathematics: algorithm development, modeling on excel of the dispersion of pollutants The pedagogy of this course is new in French high-schools : pupils work in groups of three, so as to develop cooperation and autonomy. The teachers give the guidelines at the beginning of each working session, and answer the students questions when necessary. The evaluation is competence-based : instead of a mark, which is the main evaluation method in France, the pupils have to evaluate their own skills. Then, the teachers make an evaluation, and the global process is

  8. Dynamic exit pupil trackers for autostereoscopic displays.

    PubMed

    Akşit, Kaan; Baghsiahi, Hadi; Surman, Phil; Ölçer, Selim; Willman, Eero; Selviah, David R; Day, Sally; Urey, Hakan

    2013-06-17

    This paper describes the first demonstrations of two dynamic exit pupil (DEP) tracker techniques for autostereoscopic displays. The first DEP tracker forms an exit pupil pair for a single viewer in a defined space with low intraocular crosstalk using a pair of moving shutter glasses located within the optical system. A display prototype using the first DEP tracker is constructed from a pair of laser projectors, pupil-forming optics, moving shutter glasses at an intermediate pupil plane, an image relay lens, and a Gabor superlens based viewing screen. The left and right eye images are presented time-sequentially to a single viewer and seen as a 3D image without wearing glasses and allows the viewer to move within a region of 40 cm × 20 cm in the lateral plane, and 30 cm along the axial axis. The second DEP optics can move the exit pupil location dynamically in a much larger 3D space by using a custom spatial light modulator (SLM) forming an array of shutters. Simultaneous control of multiple exit pupils in both lateral and axial axes is demonstrated for the first time and provides a viewing volume with an axial extent of 0.6-3 m from the screen and within a lateral viewing angle of ± 20° for multiple viewers. This system has acceptable crosstalk (< 5%) between the stereo image pairs. In this novel version of the display the optical system is used as an advanced dynamic backlight for a liquid crystal display (LCD). This has advantages in terms of overall display size as there is no requirement for an intermediate image, and in image quality. This system has acceptable crosstalk (< 5%) between the stereo image pairs.

  9. Analysis of Pupil Replication

    NASA Astrophysics Data System (ADS)

    Spaan, F. H. P.; Greenaway, A. H.

    2007-04-01

    Pupil replication and hypertelescope systems for imaging telluric exoplanets in scattered light are treated. Analytic expressions for the spread functions in one and two dimensions and in the presence of various forms of error are given. Error effects considered include aperture misalignment, tilts, piston, pointing errors, and unequal beam amplitude. The performance of the two approaches is contrasted, and the analytic results are compared with simulation results.

  10. Luminance distribution modifies the perceived freshness of strawberries

    PubMed Central

    Arce-Lopera, Carlos; Masuda, Tomohiro; Kimura, Atsushi; Wada, Yuji; Okajima, Katsunori

    2012-01-01

    Material perception studies focus on the analysis of visual cues that may underlie the ability to distinguish between the different properties of an object. Herein, we investigated the effects of luminance distribution on the perceived freshness of a strawberry independent from its colour information. We took photographs of the degradation of a strawberry over 169 hours in a controlled environment, then presented cropped square patches of the original images to subjects who then rated the perceived freshness using a visual analogue scale. Freshness ratings were significantly highly correlated with statistical measures of the luminance and colour channels. To clarify which of these visual cues affects freshness perception, we created artificial images by modifying only the luminance distribution and keeping the colour information unchanged. The modification of luminance resulted in a highly correlated change in freshness perception, suggesting that luminance visual cues are essential to the freshness perception of strawberries. Finally, by eliminating the colour information from the images, we examined the contribution of luminance distribution independent of colour information and found that luminance information suffices for accurate estimation of strawberry freshness. PMID:23145288

  11. Selective Modulation of the Pupil Light Reflex by Microstimulation of Prefrontal Cortex.

    PubMed

    Ebitz, R Becket; Moore, Tirin

    2017-05-10

    The prefrontal cortex (PFC) is thought to flexibly regulate sensorimotor responses, perhaps through modulating activity in other circuits. However, the scope of that control remains unknown: it remains unclear whether the PFC can modulate basic reflexes. One canonical example of a central reflex is the pupil light reflex (PLR): the automatic constriction of the pupil in response to luminance increments. Unlike pupil size, which depends on the interaction of multiple physiological and neuromodulatory influences, the PLR reflects the action of a simple brainstem circuit. However, emerging behavioral evidence suggests that the PLR may be modulated by cognitive processes. Although the neural basis of these modulations remains unknown, one possible source is the PFC, particularly the frontal eye field (FEF), an area of the PFC implicated in the control of attention. We show that microstimulation of the rhesus macaque FEF alters the magnitude of the PLR in a spatially specific manner. FEF microstimulation enhanced the PLR to probes presented within the stimulated visual field, but suppressed the PLR to probes at nonoverlapping locations. The spatial specificity of this effect parallels the effect of FEF stimulation on attention and suggests that FEF is capable of modulating visuomotor transformations performed at a lower level than was previously known. These results provide evidence of the selective regulation of a basic brainstem reflex by the PFC.SIGNIFICANCE STATEMENT The pupil light reflex (PLR) is our brain's first and most fundamental mechanism for light adaptation. Although it is often described in textbooks as being an immutable reflex, converging evidence suggests that the magnitude of the PLR is modulated by cognitive factors. The neural bases of these modulations are unknown. Here, we report that microstimulation in the prefrontal cortex (PFC) modulates the gain of the PLR, changing how a simple reflex circuit responds to physically identical stimuli. These

  12. An evaluation of organic light emitting diode monitors for medical applications: Great timing, but luminance artifacts

    PubMed Central

    Elze, Tobias; Taylor, Christopher; Bex, Peter J.

    2013-01-01

    Purpose: In contrast to the dominant medical liquid crystal display (LCD) technology, organic light-emitting diode (OLED) monitors control the display luminance via separate light-emitting diodes for each pixel and are therefore supposed to overcome many previously documented temporal artifacts of medical LCDs. We assessed the temporal and luminance characteristics of the only currently available OLED monitor designed for use in the medical treatment field (SONY PVM2551MD) and checked the authors’ main findings with another SONY OLED device (PVM2541). Methods: Temporal properties of the photometric output were measured with an optical transient recorder. Luminances of the three color primaries and white for all 256 digital driving levels (DDLs) were measured with a spectroradiometer. Between the luminances of neighboring DDLs, just noticeable differences were calculated according to a perceptual model developed for medical displays. Luminances of full screen (FS) stimuli were compared to luminances of smaller stimuli with identical DDLs. Results: All measured luminance transition times were below 300 μs. Luminances were independent of the luminance in the preceding frame. However, for the single color primaries, up to 50.5% of the luminances of neighboring DDLs were not perceptually distinguishable. If two color primaries were active simultaneously, between 36.7% and 55.1% of neighboring luminances for increasing DDLs of the third primary were even decreasing. Moreover, luminance saturation effects were observed when too many pixels were active simultaneously. This effect was strongest for white; a small white patch was close to 400 cd/m2, but in FS the luminance of white saturated at 162 cd/m2. Due to different saturation levels, the luminance of FS green and FS yellow could exceed the luminance of FS white for identical DDLs. Conclusions: The OLED temporal characteristics are excellent and superior to those of LCDs. However, the OLEDs revealed severe

  13. An evaluation of organic light emitting diode monitors for medical applications: great timing, but luminance artifacts.

    PubMed

    Elze, Tobias; Taylor, Christopher; Bex, Peter J

    2013-09-01

    In contrast to the dominant medical liquid crystal display (LCD) technology, organic light-emitting diode (OLED) monitors control the display luminance via separate light-emitting diodes for each pixel and are therefore supposed to overcome many previously documented temporal artifacts of medical LCDs. We assessed the temporal and luminance characteristics of the only currently available OLED monitor designed for use in the medical treatment field (SONY PVM2551MD) and checked the authors' main findings with another SONY OLED device (PVM2541). Temporal properties of the photometric output were measured with an optical transient recorder. Luminances of the three color primaries and white for all 256 digital driving levels (DDLs) were measured with a spectroradiometer. Between the luminances of neighboring DDLs, just noticeable differences were calculated according to a perceptual model developed for medical displays. Luminances of full screen (FS) stimuli were compared to luminances of smaller stimuli with identical DDLs. All measured luminance transition times were below 300 μs. Luminances were independent of the luminance in the preceding frame. However, for the single color primaries, up to 50.5% of the luminances of neighboring DDLs were not perceptually distinguishable. If two color primaries were active simultaneously, between 36.7% and 55.1% of neighboring luminances for increasing DDLs of the third primary were even decreasing. Moreover, luminance saturation effects were observed when too many pixels were active simultaneously. This effect was strongest for white; a small white patch was close to 400 cd/m(2), but in FS the luminance of white saturated at 162 cd/m(2). Due to different saturation levels, the luminance of FS green and FS yellow could exceed the luminance of FS white for identical DDLs. The OLED temporal characteristics are excellent and superior to those of LCDs. However, the OLEDs revealed severe perceptually relevant artifacts with

  14. Relationships Between Teacher Behavior, Pupil Behavior, and Pupil Achievement.

    ERIC Educational Resources Information Center

    Bemis, Katherine A.; Luft, Max

    In this study, which was designed to examine the relationships among teacher behavior, student behavior, and student achievement, the Southwestern Cooperative Educational Laboratory Interaction Observation Schedule (SCIOS) was developed. Using this instrument, pupil behaviors were isolated to assess the degree to which pupils (1) receive, (2)…

  15. Keeping an eye on the truth? Pupil size changes associated with recognition memory.

    PubMed

    Heaver, Becky; Hutton, Sam B

    2011-05-01

    During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this "pupil old/new effect" and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructions to report all items as new. Participants' pupils dilated more to old items compared to new items under all three instruction conditions. This finding suggests that the increase in pupil size that occurs when participants encounter previously studied items is not under conscious control. Given that pupil size can be reliably and simply measured, the pupil old/new effect may have potential in clinical settings as a means for determining whether patients are feigning memory loss.

  16. Spectropolarimetry of hot, luminous stars

    NASA Technical Reports Server (NTRS)

    Schulte-Ladbeck, Regina E.

    1994-01-01

    I review polarimetric observations of presumably single, hot luminous stars. The stellar types discussed are OB stars. B(e) supergiants, Luminous Blue Variables (LBV), Wolf-Rayet (W-R) stars, and type II supernovae (SN). It is shown that variable, intrinsic polarization is a common phenomenon in that part of the Hertzsprung-Russell (HR) diagram which these stars occupy. However, much observational work remains to be done before we can answer the most basic, statistical questions about the polarimetric properties of different groups of hot, luminous stars. Insight into the diagnostic power of polarization observations has been gained, but cannot be exploited without detailed models. Thus, while polarimetric observations do tell us that the mass-loss processes of all types of massive stars are time-dependent and anisotropic, the significance that this might have for the accuracy of their stellar parameters and evolutionary paths remains elusive.

  17. Oregon Pupil Transportation Manual, 1989.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Education, Salem.

    This manual provides school bus drivers and school officials with pertinent material relating to safe and efficent school transportation. Chapter I presents the laws governing pupil transportation. Oregon motor vehicle laws are identified by an ORS (Oregon Revised Statute) number, and pupil transportation regulations are identified by an OAR…

  18. SCOPE OF PUPIL PERSONNEL SERVICES.

    ERIC Educational Resources Information Center

    ECKERSON, LOUISE OMWAKE; SMITH, HYRUM M.

    PART I OF THIS PAMPHLET DESCRIBES THE INTERPROFESSIONAL RESEARCH COMMISSION ON PUPIL PERSONNEL SERVICES, WHICH WAS STARTED IN 1962 BY THE OFFICE OF EDUCATION AND FINANCED BY THE NATIONAL INSTITUTE OF MENTAL HEALTH FOR A 5-YEAR PROGRAM. THE REST OF THE PAMPHLET DEALS WITH STATISTICS AND SPECIFIC PUPIL PERSONNEL SERVICES. OF THE 60,000…

  19. Cross spread pupil tracking technique

    NASA Astrophysics Data System (ADS)

    Wolski, Krzysztof; Mantiuk, Radosław

    2016-11-01

    We present a fast and minimum delay algorithm for detecting the pupil center, called the "cross spread" tracking technique. This algorithm is meant for video eye trackers that estimate gaze direction from the position of the pupil center in the captured images. Contrary to other solutions, we do not try to make this technique robust to distractors such as reflections, distortions caused by glasses, or eyelids covering the pupil, but rather we assume eye tracking in stable light conditions. We argue that this approach is useful in many eye tracking applications, such as gaze tracking during psychophysical experiments in stable laboratory conditions, and that this approach can significantly reduce the eye tracker's complexity while maintaining its accuracy and performance. The proposed cross spread technique estimates pupil by tracing rays in horizontal and vertical directions in the image, starting from a point in the pupil region and continuing to the pupil boundary. The found boundary points determine the next starting point and the procedure is iteratively repeated. Parallel processing can be efficiently used enabling accurate pupil center detection in <2 ms on typical laptops. We compare the proposed algorithm to other pupil detection algorithms.

  20. What Are the Earth and the Heavenly Bodies Like? A Study of Objectual Conceptions among Norwegian Deaf and Hearing Pupils.

    ERIC Educational Resources Information Center

    Roald, Ingvild; Mikalsen, Oyvind

    2000-01-01

    Addresses deaf pupils' conceptions of directly-observed phenomena of the earth and sky. Studies 7-, 9-, 11-, and 17-year-old deaf pupils and uses 9-year-old Norwegian pupils with normal hearing as the control group. Reports that the children's conceptions are scientifically accepted. Indicates that the shape of the sign representing an object may…

  1. [Tonic pupil caused by ischemia].

    PubMed

    Wilhelm, H

    1989-01-01

    Tonic pupil is usually an idiopathic condition. In some cases, the cause of the ciliary ganglion lesion leading to tonic pupils is obvious. Rarely ischemia causes a lesion of the ciliary ganglion or the short ciliary nerves due to the good blood supply of the ciliary ganglion. Only two cases of tonic pupils in the course of giant cell arteritis are mentioned in the literature, but tonic pupils are probably much more common with this disease. Five cases are demonstrated here. All had associated ischemic optic neuropathy, and stagnation of the blood flow in the supratrochlear artery could be demonstrated in two cases by Doppler sonography. Tonic pupils may also occur when an oclusion of the internal carotid artery resolves, probably because of transient stasis of the orbital blood flow. In another case, tonic pupils were associated with choroidal ischemia (proved by video fluorescent angiography) of unknown origin. The diagnosis of tonic pupils was made by pharmacological testing for cholinergic hypersensitivity with 0.1% pilocarpine.

  2. 78 FR 69710 - Luminant Generation Company, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-20

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Luminant Generation Company, LLC AGENCY: U.S. Nuclear Regulatory Commission (NRC). ACTION... consecutive weeks of a combined license (COL) application from Luminant Generation Company, LLC....

  3. 78 FR 66785 - Luminant Generation Company, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

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  4. 78 FR 70964 - Luminant Generation Company, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

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  5. 78 FR 68100 - Luminant Generation Company, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

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  6. Can pupil size and pupil responses during visual scanning contribute to the diagnosis of autism spectrum disorder in children?

    PubMed

    Martineau, Joëlle; Hernandez, Nadia; Hiebel, Lorraine; Roché, Laetitia; Metzger, Aude; Bonnet-Brilhault, Frédérique

    2011-08-01

    The purpose of this study was to determine whether baseline pupil size and pupil responses during visual scanning with eye-tracking technology could discriminate children with autism spectrum disorder (ASD) from mental age-matched and chronological age-matched controls. To this end, we used stimuli consisting in still color photographs presented centrally to the participant's midline on a stimulus monitor. Each child was presented with a series of neutral faces, virtual faces (avatars) and different objects, separated by black slides. We recorded the mean pupil size and pupil size changes over time in each of the three categories of stimuli and during exposure to the black slides. Fifty-seven children participated in study (19 ASD, mean age 118 months; 19 mental age-matched controls, mean age 87 months; and 19 chronological age-matched controls, mean age 118 months). We compared the baseline pupil size and pupil responses during visual scanning among the three diagnostic groups. During the presentation of slides, the mean pupil size in the ASD group was clearly smaller than in the MA-matched and CA-matched groups. Discriminate analysis of pupil size during the presentation of black slides and slides with visual stimuli successfully predicted group membership in 72% of the participants. Group membership was correctly classified in 89% of the participants in the ASD group, in 63% in the MA-matched group and in 63% in the CA-matched group. These potential biomarkers may contribute to our understanding of the differences in neurological development in the brain in autism and could prove useful as indicators of ASD.

  7. Calibration of imaging luminance measuring devices (ILMD)

    NASA Astrophysics Data System (ADS)

    Liu, Liying; Zheng, Feng; Zhu, Lingxi; Li, Ye; Huan, Kewei; Shi, Xiaoguang

    2015-11-01

    A method of calibration of imaging luminance measuring devices has been studied. By the device-independent color space transformation, the color image by digital camera could be converted to the CIE's absolute color space lab. Then, the calibration model is fitted between ln(L/t) and luminance. At last, luminance image is obtained and the dynamic range of luminance image could be adjusted by shutter speed.

  8. Pupil geometry and pupil re-imaging in telescope arrays

    NASA Technical Reports Server (NTRS)

    Traub, Wesley A.

    1990-01-01

    This paper considers the issues of lateral and longitudinal pupil geometry in ground-based telescope arrays, such as IOTA. In particular, it is considered whether or not pupil re-imaging is required before beam combination. By considering the paths of rays through the system, an expression is derived for the optical path errors in the combined wavefront as a function of array dimensions, telescope magnification factor, viewing angle, and field-of-view. By examining this expression for the two cases of pupil-plane and image-plane combination, operational limits can be found for any array. As a particular example, it is shown that for IOTA no pupil re-imaging optics will be needed.

  9. Homeostatic control of slow vacuolar channels by luminal cations and evaluation of the channel-mediated tonoplast Ca2+ fluxes in situ

    PubMed Central

    Pérez, V.; Wherrett, T.; Shabala, S.; Muñiz, J.; Dobrovinskaya, O.; Pottosin, I.

    2008-01-01

    Ca2+, Mg2+, and K+ activities in red beet (Beta vulgaris L.) vacuoles were evaluated using conventional ion-selective microelectrodes and, in the case of Ca2+, by non-invasive ion flux measurements (MIFE) as well. The mean vacuolar Ca2+ activity was ∼0.2 mM. Modulation of the slow vacuolar (SV) channel voltage dependence by Ca2+ in the absence and presence of other cations at their physiological concentrations was studied by patch-clamp in excised tonoplast patches. Lowering pH at the vacuolar side from 7.5 to 5.5 (at zero vacuolar Ca2+) did not affect the channel voltage dependence, but abolished sensitivity to luminal Ca2+ within a physiological range of concentrations (0.1–1.0 mM). Aggregation of the physiological vacuolar Na+ (60 mM) and Mg2+ (8 mM) concentrations also results in the SV channel becoming almost insensitive to vacuolar Ca2+ variation in a range from nanomoles to 0.1 mM. At physiological cation concentrations at the vacuolar side, cytosolic Ca2+ activates the SV channel in a voltage-independent manner with Kd=0.7–1.5 μM. Comparison of the vacuolar Ca2+ fluxes measured by both the MIFE technique and from estimating the SV channel activity in attached patches, suggests that, at resting membrane potentials, even at elevated (20 μM) cytosolic Ca2+, only 0.5% of SV channels are open. This mediates a Ca2+ release of only a few pA per vacuole (∼0.1 pA per single SV channel). Overall, our data suggest that the release of Ca2+ through SV channels makes little contribution to a global cytosolic Ca2+ signal. PMID:18832189

  10. Relationships between pupil diameter and neuronal activity in the locus coeruleus, colliculi, and cingulate cortex

    PubMed Central

    Joshi, Siddhartha; Li, Yin; Kalwani, Rishi; Gold, Joshua I.

    2015-01-01

    SUMMARY Changes in pupil diameter that reflect effort and other cognitive factors are often interpreted in terms of the activity of norepinephrine-containing neurons in the brainstem nucleus locus coeruleus (LC), but there is little direct evidence for such a relationship. Here we show that LC activation reliably anticipates changes in pupil diameter that either fluctuate naturally or are driven by external events during near fixation, as in many psychophysical tasks. This relationship occurs on as fine a temporal and spatial scale as single spikes from single units. However, this relationship is not specific to the LC. Similar relationships, albeit with delayed timing and different reliabilities across sites, are evident in the inferior and superior colliculus and anterior and posterior cingulate cortex. Because these regions are interconnected with the LC, the results suggest that non-luminance-mediated changes in pupil diameter might reflect LC-mediated coordination of neuronal activity throughout some parts of the brain. PMID:26711118

  11. The pupil's response to affective pictures: Role of image duration, habituation, and viewing mode

    PubMed Central

    O'Farrell, Katherine R.; Burley, Daniel; Erichsen, Jonathan T.; Newton, Naomi V.; Gray, Nicola S.

    2016-01-01

    Abstract The pupil has been shown to be sensitive to the emotional content of stimuli. We examined this phenomenon by comparing fearful and neutral images carefully matched in the domains of luminance, image contrast, image color, and complexity of content. The pupil was more dilated after viewing affective pictures, and this effect was (a) shown to be independent of the presentation time of the images (from 100–3,000 ms), (b) not diminished by repeated presentations of the images, and (c) not affected by actively naming the emotion of the stimuli in comparison to passive viewing. Our results show that the emotional modulation of the pupil is present over a range of variables that typically vary from study to study (image duration, number of trials, free viewing vs. task), and encourages the use of pupillometry as a measure of emotional processing in populations where alternative techniques may not be appropriate. PMID:27172997

  12. The pupil's response to affective pictures: Role of image duration, habituation, and viewing mode.

    PubMed

    Snowden, Robert J; O'Farrell, Katherine R; Burley, Daniel; Erichsen, Jonathan T; Newton, Naomi V; Gray, Nicola S

    2016-08-01

    The pupil has been shown to be sensitive to the emotional content of stimuli. We examined this phenomenon by comparing fearful and neutral images carefully matched in the domains of luminance, image contrast, image color, and complexity of content. The pupil was more dilated after viewing affective pictures, and this effect was (a) shown to be independent of the presentation time of the images (from 100-3,000 ms), (b) not diminished by repeated presentations of the images, and (c) not affected by actively naming the emotion of the stimuli in comparison to passive viewing. Our results show that the emotional modulation of the pupil is present over a range of variables that typically vary from study to study (image duration, number of trials, free viewing vs. task), and encourages the use of pupillometry as a measure of emotional processing in populations where alternative techniques may not be appropriate.

  13. Chromospheres of Luminous Cool Stars

    NASA Astrophysics Data System (ADS)

    Dupree, Andrea K.; Avrett, Eugene

    2015-08-01

    Ultraviolet imaging of Alpha Orionis (Betelgeuse) reveals a complex variable chromospheric structure. Such atmospheres in luminous cool stars can affect features in the optical spectrum. Constructing semi-empiricalmodel atmospheres of luminous stars including the temperature rise due to a chromosphere allows us to predict potential effects on optical transitions. The radiative transfer code, PANDORA, calculates line strengths in a LTE or non-LTE formulation, spherical symmetry, and includes velocity fields when present. Various aspects of the line calculations and their impact on equivalent widths will be discussed including developing appropriate chromospheric models, comparison to a pure radiative equilibrium model, transitions sensitive to non-LTE and the effects of a realistic spherical non-LTE approximation as compared to a plane-parallel approximation. We discuss the extent to which a chromosphere can impact the determination of stellar abundances.

  14. Teaching Styles and Pupil Progress

    ERIC Educational Resources Information Center

    Rogers, Vincent; Baron, Joan

    1977-01-01

    Critically analyzes Neville Bennett's book "Teaching Styles and Pupil Progress," which found that formal teaching styles are more closely associated with student achievement in "basic skills" than are informal styles. (IRT)

  15. Reprocessing in Luminous Disks

    NASA Technical Reports Server (NTRS)

    Bell, K. Robbins; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    We develop and investigate a procedure that accounts for disk reprocessing of photons that originate in the disk itself. Surface temperatures and simple, black body spectral energy distributions (SEDs) of protostellar disks are calculated. In disks that flare with radius, reprocessing of stellar photons results in temperature profiles considerably shallower than r(sup -3/4). Including the disk as a radiation source (as in the case of actively secreting disks) along with the stellar source further flattens the temperature profile. Disks that flare strongly near the star and then smoothly curve over and become shadowed at some distance ("decreasing curvature" disks) exhibit nearly power-law temperature profiles which result in power-law infrared SEDs with slopes in agreement with typical observations of young stellar objects. Disk models in which the photospheric thickness is controlled by the local opacity and in which the temperature decreases with radius naturally show this shape. Uniformly flaring models do not match observations as well; progressively stronger reprocessing at larger radii leads to SEDs that flatten toward the infrared or even have a second peak at the wavelength corresponding (through the Wien law) to the temperature of the outer edge of the disk. In FU Orionis outbursting systems, the dominant source of energy is the disk itself. The details of the reprocessing depend sensitively on the assumed disk shape and emitted temperature profile. The thermal instability outburst models of Bell Lin reproduce trends in the observed SEDs of Fuors with T varies as r(sup -3/4) in the inner disk (r approx. less than 0.25au corresponding to lambda approx. less than 10 microns) and T varies as r(sup -1/2) in the outer disk. Surface irradiation during outburst and quiescence is compared in the region of planet formation (1 - 10 au). The contrast between the two phases is diminished by the importance of the reprocessing of photons from the relatively high mass

  16. Reprocessing in Luminous Disks

    NASA Technical Reports Server (NTRS)

    Bell, K. Robbins; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    We develop and investigate a procedure that accounts for disk reprocessing of photons that originate in the disk itself. Surface temperatures and simple, black body spectral energy distributions (SEDs) of protostellar disks are calculated. In disks that flare with radius, reprocessing of stellar photons results in temperature profiles considerably shallower than r(sup -3/4). Including the disk as a radiation source (as in the case of actively secreting disks) along with the stellar source further flattens the temperature profile. Disks that flare strongly near the star and then smoothly curve over and become shadowed at some distance ("decreasing curvature" disks) exhibit nearly power-law temperature profiles which result in power-law infrared SEDs with slopes in agreement with typical observations of young stellar objects. Disk models in which the photospheric thickness is controlled by the local opacity and in which the temperature decreases with radius naturally show this shape. Uniformly flaring models do not match observations as well; progressively stronger reprocessing at larger radii leads to SEDs that flatten toward the infrared or even have a second peak at the wavelength corresponding (through the Wien law) to the temperature of the outer edge of the disk. In FU Orionis outbursting systems, the dominant source of energy is the disk itself. The details of the reprocessing depend sensitively on the assumed disk shape and emitted temperature profile. The thermal instability outburst models of Bell Lin reproduce trends in the observed SEDs of Fuors with T varies as r(sup -3/4) in the inner disk (r approx. less than 0.25au corresponding to lambda approx. less than 10 microns) and T varies as r(sup -1/2) in the outer disk. Surface irradiation during outburst and quiescence is compared in the region of planet formation (1 - 10 au). The contrast between the two phases is diminished by the importance of the reprocessing of photons from the relatively high mass

  17. Bilateral tonic pupils: Holmes Adie syndrome or generalised neuropathy?

    PubMed

    Bremner, F D; Smith, S E

    2007-12-01

    To compare the pupil signs in patients with bilateral pupillotonia caused by Holmes-Adie syndrome or generalised peripheral neuropathy. Infrared video pupillographic techniques were used to measure a number of pupil variables in patients with Holmes-Adie syndrome, generalised neuropathy (various aetiologies) and healthy age-matched control subjects. Regardless of aetiology, the patients generally had pupil signs typical of pupillotonia (small dark diameters, large light diameters, tonic near responses, attenuated light responses with light-near dissociation, and sector palsy). However, significant differences were found in the prevalence and magnitude of several pupil variables in the two patient groups. In particular, sector palsy and anisocoria exceeding 1 mm (in the light) were seen much more commonly in Holmes-Adie patients than patients with generalised neuropathy. The presence of both these pupil signs can be used to distinguish between these diagnoses with a sensitivity of 58% and a specificity of 90%. The tonic pupils of patients with Holmes-Adie syndrome are significantly different to those found in patients with generalised neuropathy; recognition of these differences may allow distinction between these diagnoses.

  18. Effect evoked by luminance and color of PC monitors in the pupillary responses and retinal illuminances

    NASA Astrophysics Data System (ADS)

    Suaste-Gomez, Ernesto; Zuoiga, Arturo; Martinez, Rosalinda

    2002-06-01

    One of the main characteristics of the reaction of the pupil is the change that undergoes due of the luminance and color of the PC monitors. In this study, we evaluated the retinal illuminance in troland, i.e., total the luminous flux that affects the surface of the retina. For this investigation all the spectral of chromaticity was considered, wavelength from 390 to 660 nm, by means of system RGB and the functions of equalization of color XYZ, were exhibited in several PC monitors. The study was made projecting over on PC monitor, in three forms: full-field chromatic stimulation, the foveal target of 2 degree(s) on background white and on background blue of 15 degree(s) in both cases. In addition, the luminance in cd/m2 of each one of the monitors was measured. In order to quantify the changes of pupil area mm2, it was made by image processing of a video-oculography, which uses a video camera with sensors and illumination in the infrared range. Necessary condition when the observer is dark-adapted in scotopic or photopic conditions. The results obtained of retinal illuminance were made since wavelength 390 to 660 nm of ten subjects including at two persons with different colour vision deficiencies.

  19. Hypertonic saline inhibits luminal sodium channels in respiratory epithelium.

    PubMed

    Hebestreit, Alexandra; Kersting, Ulrich; Hebestreit, Helge

    2007-05-01

    Physical exercise with increased ventilation leads to a considerable rise in water loss from the airways. The mechanisms underlying the regulation of transepithelial fluid transport necessary to compensate for these losses are unknown but may include changes in luminal ion channel conductance. The present study was designed to examine the effects of an increase in luminal chloride and sodium concentrations which may locally occur during hyperventilation on luminal ion conductance in the respiratory epithelium of healthy controls and patients diagnosed with cystic fibrosis (CF). Changes in luminal chloride and sodium conductance were inferred by recording nasal potential difference in eight healthy subjects and 10 patients with CF, using superfusing solutions based on isotonic saline (150 mM) on one occasion and solutions based on hypertonic saline (300 mM) on the other. Switching from isotonic to hypertonic saline superfusion decreased potential difference in controls and CF patients significantly. Amiloride induced a decrease of potential difference which was larger with isotonic than with hypertonic saline (controls 9.5 +/- 6.1 vs. 3.7 +/- 4.6 mV; CF 17.2 +/- 7.2 vs. 9.8 +/- 7.6 mV). Chloride conductance stimulated with solutions low in chloride and containing isoproterenol was not significantly changed by hypertonic saline solutions compared with isotonic solutions in both groups. The findings indicate a significant inhibition of luminal sodium conductance by high luminal sodium concentrations. This mechanism may be involved in the regulation of fluid transport across the respiratory epithelium during exercise and in the improvement of mucociliary clearance and lung functions with inhalation of hypertonic saline in CF.

  20. Retinal ganglion cell adaptation to small luminance fluctuations.

    PubMed

    Freeman, Daniel K; Graña, Gilberto; Passaglia, Christopher L

    2010-08-01

    To accommodate the wide input range over which the visual system operates within the narrow output range of spiking neurons, the retina adjusts its sensitivity to the mean light level so that retinal ganglion cells can faithfully signal contrast, or relative deviations from the mean luminance. Given the large operating range of the visual system, the majority of work on luminance adaptation has involved logarithmic changes in light level. We report that luminance gain controls are recruited for remarkably small fluctuations in luminance as well. Using spike recordings from the rat optic tract, we show that ganglion cell responses to a brief flash of light are modulated in amplitude by local background fluctuations as little as 15% contrast. The time scale of the gain control is rapid (<125 ms), at least for on cells. The retinal locus of adaptation precedes the ganglion cell spike generator because response gain changes of on cells were uncorrelated with firing rate. The mechanism seems to reside within the inner retinal network and not in the photoreceptors, because the adaptation profiles of on and off cells differed markedly. The response gain changes follow Weber's law, suggesting that network mechanisms of luminance adaptation described in previous work modulates retinal ganglion cell sensitivity, not just when we move between different lighting environments, but also as our eyes scan a visual scene. Finally, we show that response amplitude is uniformly reduced for flashes on a modulated background that has spatial contrast, indicating that another gain control that integrates luminance signals nonlinearly over space operates within the receptive field center of rat ganglion cells.

  1. Induced p53 loss in mouse luminal cells causes clonal expansion and development of mammary tumours

    PubMed Central

    Tao, Luwei; Xiang, Dongxi; Xie, Ying; Bronson, Roderick T.; Li, Zhe

    2017-01-01

    Most breast cancers may have a luminal origin. TP53 is one of the most frequently mutated genes in breast cancers. However, how p53 deficiency contributes to breast tumorigenesis from luminal cells remains elusive. Here we report that induced p53 loss in Krt8+ mammary luminal cells leads to their clonal expansion without directly affecting their luminal identity. All induced mice develop mammary tumours with 9qA1 (Yap1) and/or 6qA2 (Met) amplification(s). These tumours exhibit a mammary stem cell (MaSC)-like expression signature and most closely resemble claudin-low breast cancer. Thus, although p53 does not directly control the luminal fate, its loss facilitates acquisition of MaSC-like properties by luminal cells and predisposes them to development of mammary tumours with loss of luminal identity. Our data also suggest that claudin-low breast cancer can develop from luminal cells, possibly via a basal-like intermediate state, although further study using a different luminal promoter is needed to fully support this conclusion. PMID:28194015

  2. Optimized shaped pupil masks for pupil with obscuration

    NASA Astrophysics Data System (ADS)

    Carlotti, Alexis; Kasdin, N. Jeremy; Vanderbei, Robert J.; Delorme, Jacques-Robert

    2012-09-01

    The main components of the SPICA coronagraphic instrument have initially been bar-code apodizing masks, i.e. shaped pupils optimized in one dimension. Their free-standing designs make them manufacturable without a glass substrate, which implies an absolute achromaticity and no additional wavefront errors. However, shaped pupils can now be optimized in two dimensions and can thus take full advantage of the geometry of any arbitrary aperture, in particular obstructed apertures such as SPICA's. Hence, 2D shaped pupils often have higher throughputs while offering the same angular resolutions and contrast. Alternatively, better resolutions or contrast can be obtained for the same throughput. Although some of these new masks are free-standing, this property cannot be constrained if the optimization problem has to remain convex linear. We propose to address this issue in different ways, and we present here examples of freestanding masks for a variety of contrasts, and inner working angles. Moreover, in all other coronagraphic instruments, contrast smaller than 10-5 can only be obtained if a dedicated adaptive optics system uses one or several deformable mirrors to compensate for wavefront aberrations. The finite number of actuators sets the size of the angular area in which quasi-static speckles can be corrected. This puts a natural limit on the outer working angle for which the shaped pupils are designed. The limited number of actuators is also responsible for an additional diffracted energy, or quilting orders, that can prevent faint companions to be detected. This effect can and must be taken into account in the optimization process. Finally, shaped pupils can be computed for a given nominal phase aberration pattern in the pupil plane, although the solutions depend in this case on the observation wavelength. We illustrate this possibility by optimizing an apodizer for the James Webb space telescope, and by testing its chromaticity and its robustness to phase changes.

  3. A wearable infrared video pupillography with multi-stimulation of consistent illumination for binocular pupil response

    NASA Astrophysics Data System (ADS)

    Mang, Ou-Yang; Ko, Mei Lan; Tsai, Yi-Chun; Chiou, Jin-Chern; Huang, Ting-Wei

    2016-03-01

    The pupil response to light can reflect various kinds of diseases which are related to physiological health. Pupillary abnormalities may be influenced on people by autonomic neuropathy, glaucoma, diabetes, genetic diseases, and high myopia. In the early stage of neuropathy, it is often asymptomatic and difficulty detectable by ophthalmologists. In addition, the position of injured nerve can lead to unsynchronized pupil response for human eyes. In our study, we design the pupilometer to measure the binocular pupil response simultaneously. It uses the different wavelength of LEDs such as white, red, green and blue light to stimulate the pupil and record the process. Therefore, the pupilometer mainly contains two systems. One is the image acquisition system, it use the two cameras modules with the same external triggered signal to capture the images of the pupil simultaneously. The other one is the illumination system. It use the boost converter ICs and LED driver ICs to supply the constant current for LED to maintain the consistent luminance in each experiments for reduced experimental error. Furthermore, the four infrared LEDs are arranged nearby the stimulating LEDs to illuminate eyes and increase contrast of image for image processing. In our design, we success to implement the function of synchronized image acquisition with the sample speed in 30 fps and the stable illumination system for precise measurement of experiment.

  4. Pupil Dilations Reflect Why Rembrandt Biased Female Portraits Leftward and Males Rightward

    PubMed Central

    Schirillo, James A.

    2014-01-01

    Portrait painters are experts at examining faces and since emotional content may be expressed differently on each side of the face, consider that Rembrandt biased his male portraits to show their right-cheek more often and female portraits to show their left-cheek more often. This raises questions regarding the emotional significance of such biased positions. I presented rightward and leftward facing male and female portraits. I measured observers’ pupil size while asking observers to report how (dis)pleasing they found each image. This was a methodological improvement over the type of research initially done by Eckhard Hess who claimed that pupils dilate to pleasant images and constrict to unpleasant images. His work was confounded since his images’ luminances and contrasts across conditions were inconsistent potentially affecting pupil size. To overcome this limitation I presented rightward or leftward facing male and female portraits by Rembrandt to observers in either their original or mirror-reversed position. I found that in viewing male portraits pupil diameter was a function of arousal. That is, larger pupil diameter occurred for images rated both low and high in pleasantness. This was not the case with female portraits. I discuss these findings in regard to the perceived dominance of males and how emotional expressions may be driven by hemispheric laterality. PMID:24454285

  5. Decision-related pupil dilation reflects upcoming choice and individual bias

    PubMed Central

    de Gee, Jan Willem; Knapen, Tomas; Donner, Tobias H.

    2014-01-01

    A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence (“yes” vs. “no”) of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker’s attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty. PMID:24449874

  6. Decision-related pupil dilation reflects upcoming choice and individual bias.

    PubMed

    de Gee, Jan Willem; Knapen, Tomas; Donner, Tobias H

    2014-02-04

    A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence ("yes" vs. "no") of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker's attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty.

  7. Characterising Nearby Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Ramphul, R.; Vaisanen, P.; Van der Heyden, K.

    2017-06-01

    Luminous InfraRed Galaxies (LIRGs) in the local universe are known to be highly interacting galaxies with strong star-formation in obscured environments. LIRGs have diversity in terms of morphology and mode and location of SF, while their even more energetic counterparts, the Ultra-Luminous IR galaxies, ULIRGs, (LIR ≥ 10^12 Lsol ) are normally (remnants of) gas rich major mergers with centralised starbursts and AGN. I will present ongoing work on a survey of >40 (U)LIRGs, in a distance range of 40 to 300Mpc, observed with SALT/RSS in long-slit mode. The sample of galaxies are in various stages of interaction and merging, some with strong AGN contribution. The reduction of the SALT/RSS data, was performed efficiently with our custom-built pipeline written in python/iraf/pyraf and handles error-frames propagation. We are performing a rigorous stellar populations analysis of our sample using Starlight (Cid Fernandes, 2005) which will ultimately lead to understanding the star formation history of these galaxies. We also use automatic line intensity measurements to derive chemical abundances, star formation rates, metallicity and emission line diagnostic. The talk will showcase the latest results that we just obtained for this dataset and discuss some of the future works.

  8. Using Advance Organizers to Enhance Pupils' Achievement in Learning Poetry in English Language

    ERIC Educational Resources Information Center

    Muiruri, Mary; Wambugu, Patriciah; Wamukuru, Kuria

    2016-01-01

    The study was a quasi-experimental that investigated the effects of Advance Organizers (AO) on achievement in poetry. Target population was class seven pupils of Nakuru North Sub-county primary schools in Kenya. 160 pupils were involved in the study. Four sampled schools were randomly assigned to control and experimental groups in Solomon Four…

  9. Stochastic analysis of the control of the movement of the spacecraft in the vicinity of the colinear libration point by means of the forces of luminous pressure

    NASA Technical Reports Server (NTRS)

    Lukyanov, S. S.

    1983-01-01

    This paper is dedicated to the possible investigation of the utilization of the solar radiation pressure for the spacecraft motion control in the vicinity of collinear libration point of planar restricted ring problem of three bodies. The control is realized by changing the solar sail area at its permanent orientation. In this problem the influence of the trajectory errors and the errors of the execution control is accounted. It is worked out, the estimation method of the solar sail sizes, which are necessary for spacecraft keeping in the vicinity of collinear libration point during the certain time with given probability. The main control parameters were calculated for some examples in case of libration points of the Sun-Earth and Earth-Moon systems.

  10. Disruption of pupil size modulation correlates with voluntary motor preparation deficits in Parkinson's disease.

    PubMed

    Wang, Chin-An; McInnis, Hailey; Brien, Donald C; Pari, Giovanna; Munoz, Douglas P

    2016-01-08

    Pupil size is an easy-to-measure, non-invasive method to index various cognitive processes. Although a growing number of studies have incorporated measures of pupil size into clinical investigation, there have only been limited studies in Parkinson's disease (PD). Convergent evidence has suggested PD patients exhibit cognitive impairment at or soon after diagnosis. Here, we used an interleaved pro- and anti-saccade paradigm while monitoring pupil size with saccadic eye movements to examine the relationship between executive function deficits and pupil size in PD patients. Subjects initially fixated a central cue, the color of which instructed them to either look at a peripheral stimulus automatically (pro-saccade) or suppress the automatic response and voluntarily look in the opposite direction of the stimulus (anti-saccade). We hypothesized that deficits of voluntary control should be revealed not only on saccadic but also on pupil responses because of the recently suggested link between the saccade and pupil control circuits. In elderly controls, pupil size was modulated by task preparation, showing larger dilation prior to stimulus appearance in preparation for correct anti-saccades, compared to correct pro-saccades, or erroneous pro-saccades made in the anti-saccade condition. Moreover, the size of pupil dilation correlated negatively with anti-saccade reaction times. However, this profile of pupil size modulation was significantly blunted in PD patients, reflecting dysfunctional circuits for anti-saccade preparation. Our results demonstrate disruptions of modulated pupil responses by voluntary movement preparation in PD patients, highlighting the potential of using low-cost pupil size measurement to examine executive function deficits in early PD.

  11. Effect of Pupil Size on Wavefront Refraction during Orthokeratology.

    PubMed

    Faria-Ribeiro, Miguel; Navarro, Rafael; González-Méijome, José Manuel

    2016-11-01

    It has been hypothesized that central and peripheral refraction, in eyes treated with myopic overnight orthokeratology, might vary with changes in pupil diameter. The aim of this work was to evaluate the axial and peripheral refraction and optical quality after orthokeratology, using ray tracing software for different pupil sizes. Zemax-EE was used to generate a series of 29 semi-customized model eyes based on the corneal topography changes from 29 patients who had undergone myopic orthokeratology. Wavefront refraction in the central 80 degrees of the visual field was calculated using three different quality metrics criteria: Paraxial curvature matching, minimum root mean square error (minRMS), and the Through Focus Visual Strehl of the Modulation Transfer Function (VSMTF), for 3- and 6-mm pupil diameters. The three metrics predicted significantly different values for foveal and peripheral refractions. Compared with the Paraxial criteria, the other two metrics predicted more myopic refractions on- and off-axis. Interestingly, the VSMTF predicts only a marginal myopic shift in the axial refraction as the pupil changes from 3 to 6 mm. For peripheral refraction, minRMS and VSMTF metric criteria predicted a higher exposure to peripheral defocus as the pupil increases from 3 to 6 mm. The results suggest that the supposed effect of myopic control produced by ortho-k treatments might be dependent on pupil size. Although the foveal refractive error does not seem to change appreciably with the increase in pupil diameter (VSMTF criteria), the high levels of positive spherical aberration will lead to a degradation of lower spatial frequencies, that is more significant under low illumination levels.

  12. Potassium selectivity of frog gastric luminal membrane.

    PubMed

    Kasbekar, D K

    1986-06-01

    Transmural potential difference (PD) and resistance (R) changes after luminal or serosal instillation of K+ were determined under various conditions in chambered preparations of frog gastric mucosae. Potassium selectivity of the luminal membrane is indicated by the rapid reversal of the inverted PD of mucosae bathed in NaCl-free, choline sulfate (Ch2SO4)-Ringer on the serosal side and unbuffered hypertonic Ch2SO4 solution on the luminal side on luminal K+ instillation. The delta PD responses are significantly attenuated, however, in histamine-stimulated mucosae bathed in hypotonic or in burimamide-inhibited mucosae bathed in hyper- and hypotonic luminal media, which suggests that the K+ selectivity of the luminal membrane resides largely in the tubular cell apical membrane. Imposing a serosal-to-luminal transmucosal K+ gradient in both histamine-stimulated and omeprazole-inhibited mucosae also reversed the normal orientation of PD but not in those inhibited with burimamide. In the latter, the PD inversion was attenuated but maintained its normal orientation. These data suggest that burimamide, but not omeprazole, acts by blocking luminal membrane K+ conductance. The inverted PD in mucosae bathed in Cl-free media may thus be due partially or fully to K+ diffusion driven by the cell-to-lumen K+ gradient via the luminal K+ conductance pathway. These findings have implications for the controversy surrounding the postulated electrogenicity of the gastric proton pump.

  13. Does the "Pupil Enterprise Programme" Influence Grades among Pupils with Special Needs?

    ERIC Educational Resources Information Center

    Johansen, Vegard; Somby, Hege M.

    2016-01-01

    This paper asks whether the Pupil Enterprise Programme (PEP) is a suitable working method for improving academic performance among pupils with special needs. Overall, 20% of pupils participate in PEP at some point during lower secondary school. Results from multilevel regression modelling indicate that pupils with special needs who have…

  14. Does the "Pupil Enterprise Programme" Influence Grades among Pupils with Special Needs?

    ERIC Educational Resources Information Center

    Johansen, Vegard; Somby, Hege M.

    2016-01-01

    This paper asks whether the Pupil Enterprise Programme (PEP) is a suitable working method for improving academic performance among pupils with special needs. Overall, 20% of pupils participate in PEP at some point during lower secondary school. Results from multilevel regression modelling indicate that pupils with special needs who have…

  15. Is Chemistry Attractive for Pupils? Czech Pupils' Perception of Chemistry

    ERIC Educational Resources Information Center

    Kubiatko, Milan

    2015-01-01

    Chemistry is an important subject due to understanding the composition and structure of the things around us. The main aim of the study was to find out the perception of chemistry by lower secondary school pupils. The partial aims were to find out the influence of gender, year of study and favorite subject on the perception of chemistry. The…

  16. Is Chemistry Attractive for Pupils? Czech Pupils' Perception of Chemistry

    ERIC Educational Resources Information Center

    Kubiatko, Milan

    2015-01-01

    Chemistry is an important subject due to understanding the composition and structure of the things around us. The main aim of the study was to find out the perception of chemistry by lower secondary school pupils. The partial aims were to find out the influence of gender, year of study and favorite subject on the perception of chemistry. The…

  17. Understanding Pupils' Hiding Techniques in Physical Education

    ERIC Educational Resources Information Center

    Lyngstad, Idar; Hagen, Per-Magnus; Aune, Ola

    2016-01-01

    Previous research shows that some pupils find physical education (PE) demanding and difficult. Some pupils use strategies to avoid participation in PE when it is demanding and difficult. The present study aims to illuminate and describe strategies used by pupils to avoid negative self-perception in difficult situations and activities in PE…

  18. Understanding Pupils' Hiding Techniques in Physical Education

    ERIC Educational Resources Information Center

    Lyngstad, Idar; Hagen, Per-Magnus; Aune, Ola

    2016-01-01

    Previous research shows that some pupils find physical education (PE) demanding and difficult. Some pupils use strategies to avoid participation in PE when it is demanding and difficult. The present study aims to illuminate and describe strategies used by pupils to avoid negative self-perception in difficult situations and activities in PE…

  19. Mapping and correcting the influence of gaze position on pupil size measurements.

    PubMed

    Hayes, Taylor R; Petrov, Alexander A

    2016-06-01

    Pupil size is correlated with a wide variety of important cognitive variables and is increasingly being used by cognitive scientists. Pupil data can be recorded inexpensively and non-invasively by many commonly used video-based eye-tracking cameras. Despite the relative ease of data collection and increasing prevalence of pupil data in the cognitive literature, researchers often underestimate the methodological challenges associated with controlling for confounds that can result in misinterpretation of their data. One serious confound that is often not properly controlled is pupil foreshortening error (PFE)-the foreshortening of the pupil image as the eye rotates away from the camera. Here we systematically map PFE using an artificial eye model and then apply a geometric model correction. Three artificial eyes with different fixed pupil sizes were used to systematically measure changes in pupil size as a function of gaze position with a desktop EyeLink 1000 tracker. A grid-based map of pupil measurements was recorded with each artificial eye across three experimental layouts of the eye-tracking camera and display. Large, systematic deviations in pupil size were observed across all nine maps. The measured PFE was corrected by a geometric model that expressed the foreshortening of the pupil area as a function of the cosine of the angle between the eye-to-camera axis and the eye-to-stimulus axis. The model reduced the root mean squared error of pupil measurements by 82.5 % when the model parameters were pre-set to the physical layout dimensions, and by 97.5 % when they were optimized to fit the empirical error surface.

  20. Mapping and correcting the influence of gaze position on pupil size measurements

    PubMed Central

    Petrov, Alexander A.

    2015-01-01

    Pupil size is correlated with a wide variety of important cognitive variables and is increasingly being used by cognitive scientists. Pupil data can be recorded inexpensively and non-invasively by many commonly used video-based eye-tracking cameras. Despite the relative ease of data collection and increasing prevalence of pupil data in the cognitive literature, researchers often underestimate the methodological challenges associated with controlling for confounds that can result in misinterpretation of their data. One serious confound that is often not properly controlled is pupil foreshortening error (PFE)—the foreshortening of the pupil image as the eye rotates away from the camera. Here we systematically map PFE using an artificial eye model and then apply a geometric model correction. Three artificial eyes with different fixed pupil sizes were used to systematically measure changes in pupil size as a function of gaze position with a desktop EyeLink 1000 tracker. A grid-based map of pupil measurements was recorded with each artificial eye across three experimental layouts of the eye-tracking camera and display. Large, systematic deviations in pupil size were observed across all nine maps. The measured PFE was corrected by a geometric model that expressed the foreshortening of the pupil area as a function of the cosine of the angle between the eye-to-camera axis and the eye-to-stimulus axis. The model reduced the root mean squared error of pupil measurements by 82.5 % when the model parameters were pre-set to the physical layout dimensions, and by 97.5 % when they were optimized to fit the empirical error surface. PMID:25953668

  1. OLED lightings with optical feedback for luminance difference compensation

    NASA Astrophysics Data System (ADS)

    Shin, D. K.; Park, J. W.

    2013-12-01

    We have employed an optical feedback circuit in an organic light-emitting diode (OLED) lighting system to ensure uniform light output across large-area OLED lighting tiles. In a lighting system with several large-area OLED lighting tiles involved, the panel aging (luminance decrease) may appear differently in each, resulting in a falling-off in lighting quality. To tackle this, light output from each OLED tile is monitored by the optical feedback circuit that consists of a photodetector, I-V converter, 10-bit analogue-digital converter (ADC), and comparator. A photodetector mounted on a glass side generates a feedback signal (current) by detecting side-emitting OLED light. To monitor bottom-emitting output light by detecting side-emitting OLED light, a mapping table between the ADC value and the luminance of bottom emission has been established. If the ADC value is lower or higher than the reference one corresponding to the target luminance of OLED tiles, a micro controller unit adjusts the pulse width modulation used for the control of the power supplied to OLED tiles in such a way that the ADC value obtained from optical feedback is the same as the reference one. As a result, the target luminance of each individual OLED tile is kept unchanged. With the optical feedback circuit included in the lighting system, we have observed less than 2% difference in relative intensity of neighboring OLED tiles.

  2. Assessing Pupils' Skills in Experimentation

    ERIC Educational Resources Information Center

    Hammann, Marcus; Phan, Thi Thanh Hoi; Ehmer, Maike; Grimm, Tobias

    2008-01-01

    This study is concerned with different forms of assessment of pupils' skills in experimentation. The findings of three studies are reported. Study 1 investigates whether it is possible to develop reliable multiple-choice tests for the skills of forming hypotheses, designing experiments and analysing experimental data. Study 2 compares scores from…

  3. Insurance: Pupils' Pamphlet. II C.

    ERIC Educational Resources Information Center

    University of the South Pacific, Suva (Fiji).

    The document presents a study guide for students learning insurance protection and the various types of insurance businesses. The pupils' pamphlet is to be used in coordination with the teacher's guide. Case studies, worksheets, description of basic principles, and examples of policy forms are provided for the different types of insurance: (1)…

  4. Enrolment and Transported Pupils Report.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    As of September, 1987, school enrollment in the Canadian province of Manitoba was 209,352, an increase of 395 pupils over the previous year. Public school enrollment was 199,390, up 353 from the previous year. This was the second consecutive increase in school enrollment following a steady decline from 1971 to 1985. The largest increase per grade…

  5. Three-zone pupil filters

    NASA Astrophysics Data System (ADS)

    Sheppard, Colin J. R.; Campos, Juan; Escalera, Juan C.; Ledesma, Silvia

    2008-07-01

    The performance of pupil filters consisting of three zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters.

  6. Middle School Pupils Write Haiku.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Pupils in the middle school can be motivated to enjoy and write haiku poetry. A student teacher taught two lessons to a sixth grade class in haiku writing. First, the student teacher read three haikus aloud to students. After discovering the characteristics of a haiku from two models, the class as a whole wrote a haiku based on slides from their…

  7. Pupil Authors and Teacher Innovators

    ERIC Educational Resources Information Center

    Parry, John.

    2004-01-01

    This article explores three aspects regarding the supporting of teaching and learning through ICT (information and communication technology). First, the use and value of storyboarding as a preferable technique prior to the creation of a pupil-authored CD-ROM by children aged 9 and 14. Second, responses to the innovation by practicing teachers.…

  8. Middle School Pupils Write Legends.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    A sixth-grade student teacher developed and implemented a unit on creative writing, and one lesson in the unit on writing legends was particularly successful. A discussion of Davy Crockett and the legends surrounding his life, began the lesson. The student teacher then introduced trade books from the library station for the pupils to read.…

  9. Insurance: Pupils' Pamphlet. II C.

    ERIC Educational Resources Information Center

    University of the South Pacific, Suva (Fiji).

    The document presents a study guide for students learning insurance protection and the various types of insurance businesses. The pupils' pamphlet is to be used in coordination with the teacher's guide. Case studies, worksheets, description of basic principles, and examples of policy forms are provided for the different types of insurance: (1)…

  10. School Lights and Problem Pupils

    ERIC Educational Resources Information Center

    Treichel-Arehart, Joan

    1974-01-01

    Pilot project results indicate that under certain conditions, fluorescent lighting may cause or aggravate hyperactivity in school children. Drawing on observations made in photobiological research, a new type of lighting was developed. Teachers in two experimental classrooms reported improvement in hyperactive pupils, which was also verified by…

  11. Pupil Transportation Safety Program Plan.

    ERIC Educational Resources Information Center

    Delahanty, Joseph F.; And Others

    This study has been undertaken to assess the magnitude of the school bus safety problem and to develop a plan to improve pupil transportation safety. The resulting report provides estimates of school bus population and daily usage, gives an account of injuries and fatalities that occur annually, and compares the safety records of school buses to…

  12. Assessing Pupils' Skills in Experimentation

    ERIC Educational Resources Information Center

    Hammann, Marcus; Phan, Thi Thanh Hoi; Ehmer, Maike; Grimm, Tobias

    2008-01-01

    This study is concerned with different forms of assessment of pupils' skills in experimentation. The findings of three studies are reported. Study 1 investigates whether it is possible to develop reliable multiple-choice tests for the skills of forming hypotheses, designing experiments and analysing experimental data. Study 2 compares scores from…

  13. Apparent speed increases at low luminance

    PubMed Central

    Vaziri-Pashkam, Maryam; Cavanagh, Patrick

    2009-01-01

    To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m2) to match that of a high-luminance one (1260 cd/m2). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. Next the role of motion smear in speed overestimation was examined. First it was shown that the length of the perceived motion smear increased at low luminances. Second, the length of the visible smear was manipulated by changing the presentation time of the stimuli. Speed overestimation was reduced at shorter presentation times. Third the speed of a blurred stimulus was compared to a stimulus with sharp edges and the blurred stimulus was judged to move faster. These results indicate that the length of motion smear following a target contributes to its perceived speed and that this leads to speed overestimation at low luminance where motion traces lengthen because of increased persistence. PMID:19146275

  14. Neurophysiological model of the normal and abnormal human pupil

    NASA Technical Reports Server (NTRS)

    Krenz, W.; Robin, M.; Barez, S.; Stark, L.

    1985-01-01

    Anatomical, experimental, and computer simulation studies were used to determine the structure of the neurophysiological model of the pupil size control system. The computer simulation of this model demonstrates the role played by each of the elements in the neurological pathways influencing the size of the pupil. Simulations of the effect of drugs and common abnormalities in the system help to illustrate the workings of the pathways and processes involved. The simulation program allows the user to select pupil condition (normal or an abnormality), specific site along the neurological pathway (retina, hypothalamus, etc.) drug class input (barbiturate, narcotic, etc.), stimulus/response mode, display mode, stimulus type and input waveform, stimulus or background intensity and frequency, the input and output conditions, and the response at the neuroanatomical site. The model can be used as a teaching aid or as a tool for testing hypotheses regarding the system.

  15. Neurophysiological model of the normal and abnormal human pupil

    NASA Technical Reports Server (NTRS)

    Krenz, W.; Robin, M.; Barez, S.; Stark, L.

    1985-01-01

    Anatomical, experimental, and computer simulation studies were used to determine the structure of the neurophysiological model of the pupil size control system. The computer simulation of this model demonstrates the role played by each of the elements in the neurological pathways influencing the size of the pupil. Simulations of the effect of drugs and common abnormalities in the system help to illustrate the workings of the pathways and processes involved. The simulation program allows the user to select pupil condition (normal or an abnormality), specific site along the neurological pathway (retina, hypothalamus, etc.) drug class input (barbiturate, narcotic, etc.), stimulus/response mode, display mode, stimulus type and input waveform, stimulus or background intensity and frequency, the input and output conditions, and the response at the neuroanatomical site. The model can be used as a teaching aid or as a tool for testing hypotheses regarding the system.

  16. Pupils teach to pupils about genetics or global warming

    NASA Astrophysics Data System (ADS)

    Cuny, Delphine

    2013-04-01

    The idea of this project is to put pupils in a teaching situation. Classes of teenagers go to primary schools and animate a science workshop. Junior pupils are separated in small groups and they attend two different sessions in the same half-day. The whole workshop consists of 4 sessions. Each session is organized with an activity (microscope observation, counting of chromosomes, drawing of a curve, etc.) in which senior pupils coach the younger, and ends with a debate or an assessment. The first experiment of this type of project was realized with a class of 14 to 15 year old pupils on the theme: How do your parents transmit your characteristics? The four sessions are attended in disorder but when knowledge of other sessions are necessary, senior pupils explain them at the beginning of the session. Junior pupils have a notebook to write their activities and to note their conclusions. Session 1: What did my father give to make me? Drawing and measuring microscopic observations of human spermatozoons. Conclusion: my father gave a spermatozoon which measures less than one mm long, this spermatozoon met my mother's egg and it made my first cell. Session 2: What does the program that made me look like? Microscope observation of blood cells, identification of chromosomes in the core. On microscope pictures, counting of chromosomes. Conclusion: My program is in each cell of my body, inside the core. Sometimes, in this core, we can observe short sticks that are called chromosomes. All human beings have the same number of chromosomes in their cells: 46. Session 3: Where do my chromosomes come from? Counting of chromosomes in spermatozoons or ovums and playing with sets of chromosomes to deduct sex of a baby. Conclusion: Daddy gave me 23 chromosomes and mummy gave me 23 chromosomes too. My program is then constituted from half of daddy's program and half of mummy's program. My brothers and sisters also have half and half, but not the same halves! Session 4: Where is the

  17. Some new luminance-gradient effects.

    PubMed

    Zavagno, D

    1999-01-01

    Three compelling luminance-gradient effects are described. The first effect concerns a brightness enhancement and a luminous mist spreading out from a central area having the same luminance as the white background and surrounded by four rectangular inducers shaded with a linear luminance gradient. The second effect is perceived with a photographically reversed configuration, and concerns what may be considered a brightness reduction or the enhancement of a darkness quality of a target area of the visual scene. The third effect concerns the perception of a self-luminous disk inside a somewhat foggy medium. The effects are worthy of further examination because they challenge current theories of luminosity perception and brightness perception in general.

  18. Perception of chromatic motion requires luminance interaction.

    PubMed

    Baraas, Rigmor C

    2005-01-01

    There is an ongoing debate related to whether chromatic motion perception arises as a consequence of a chromatic signal only (eg Wandell et al 1999 Neuron 24 901-909) or a signal that is essentially based on luminance processes (luminance artifacts) (Mullen et al 2003 Vision Research 43 1235-1247). These two views conform to the idea that colour and luminance processes are physiologically independent (Livingstone and Hubel 1988 Science 240 740-749), but according to other reports many primary cortical 'V1' cells respond to both colour and luminance contrast (eg Vidyasagar et al 2002 European Journal of Neuroscience 16 945-956). A psychophysical task was designed to test whether possible interaction between luminance and chromatic contrast could account for perception of chromatic motion. It is shown that subjects respond in a manner that reflects involvement of both processes.

  19. Impact of Pupil Transmission Apodization on Presbyopic Through-Focus Visual Performance With Spherical Aberration

    PubMed Central

    Zheleznyak, Len; Jung, HaeWon; Yoon, Geunyoung

    2014-01-01

    Purpose. To investigate the impact on through-focus retinal image quality and visual performance of apodizing the pupil's transmission function in combination with extended depth of focus presbyopic corrections, such as spherical aberration (SA). Methods. Through-focus retinal image quality was determined theoretically for various magnitudes of pupil transmission apodization and Zernike primary SA (−0.5 to +0.5 μm) for a 4-mm pupil. The impact of pupil transmission apodization was also assessed psychophysically with a vision simulator equipped with a liquid crystal spatial light modulator for controlling pupil transmission. Through-focus visual acuity (VA) was measured with and without apodization in three cyclopleged subjects from distance to near with monochromatic light (550 nm) under two multifocal aberration conditions. Phase plates induced +0.2 and −0.2 μm of SA over a 4-mm artificial pupil. A baseline condition of zero SA was also included for comparison. Results. The theoretical investigation showed that pupil transmission apodization significantly improved distance image quality in the presence of positive and negative SA. Retinal image quality at all target vergences for negative SA conditions was improved by apodization. Pupil transmission apodization improved through-focus VA by 0.1 to 0.2 logMAR at intermediate and near object distances for the zero and negative SA conditions. In the positive SA condition, apodization degraded VA by approximately 0.1 logMAR at intermediate object distances. Conclusions. Pupil transmission apodization had a significant impact on though-focus visual performance. Pupil transmission apodization affects through-focus retinal image quality by diminishing the relative contribution to the retinal image from the peripheral region of the wavefront aberration. Through-focus visual performance in presbyopic eyes with negative SA was improved due to pupil transmission apodization. PMID:24265022

  20. Does pupil constriction under blue and green monochromatic light exposure change with age?

    PubMed

    Daneault, Véronique; Vandewalle, Gilles; Hébert, Marc; Teikari, Petteri; Mure, Ludovic S; Doyon, Julien; Gronfier, Claude; Cooper, Howard M; Dumont, Marie; Carrier, Julie

    2012-06-01

    Many nonvisual functions are regulated by light through a photoreceptive system involving melanopsin-expressing retinal ganglion cells that are maximally sensitive to blue light. Several studies have suggested that the ability of light to modulate circadian entrainment and to induce acute effects on melatonin secretion, subjective alertness, and gene expression decreases during aging, particularly for blue light. This could contribute to the documented changes in sleep and circadian regulatory processes with aging. However, age-related modification in the impact of light on steady-state pupil constriction, which regulates the amount of light reaching the retina, is not demonstrated. We measured pupil size in 16 young (22.8±4 years) and 14 older (61±4.4 years) healthy subjects during 45-second exposures to blue (480 nm) and green (550 nm) monochromatic lights at low (7×10(12) photons/cm2/s), medium (3×10(13) photons/cm2/s), and high (10(14) photons/cm2/s) irradiance levels. Results showed that young subjects had consistently larger pupils than older subjects for dark adaptation and during all light exposures. Steady-state pupil constriction was greater under blue than green light exposure in both age groups and increased with increasing irradiance. Surprisingly, when expressed in relation to baseline pupil size, no significant age-related differences were observed in pupil constriction. The observed reduction in pupil size in older individuals, both in darkness and during light exposure, may reduce retinal illumination and consequently affect nonvisual responses to light. The absence of a significant difference between age groups for relative steady-state pupil constriction suggests that other factors such as tonic, sympathetic control of pupil dilation, rather than light sensitivity per se, account for the observed age difference in pupil size regulation. Compared to other nonvisual functions, the light sensitivity of steady-state pupil constriction appears to

  1. Does pupil constriction under blue and green monochromatic light exposure change with age?

    PubMed Central

    Daneault, Véronique; Vandewalle, Gilles; Hébert, Marc; Teikari, Petteri; Mure, Ludovic S.; Doyon, Julien; Gronfier, Claude; Cooper, Howard M.; Dumont, Marie; Carrier, Julie

    2017-01-01

    Many non-visual functions are regulated by light through a photoreceptive system involving melanopsin-expressing retinal ganglion cells that are maximally sensitive to blue light. Several studies have suggested that the ability of light to modulate circadian entrainment and to induce acute effects on melatonin secretion, subjective alertness and gene expression, decreases during aging, particularly for blue light. This could contribute to the documented changes in sleep and circadian regulatory processes with aging. However, age-related modification in the impact of light on steady-state pupil constriction, which regulates the amount of light reaching the retina, is not demonstrated. We measured pupil size in 16 young (22.8±4y) and 14 older (61±4.4y) healthy subjects during 45s exposures to blue (480nm) and green (550nm) monochromatic lights at low (7×1012 photons/cm2/s), medium (3×1013 photons/cm2/s), and high (1014 photons/cm2/s) irradiance levels. Results showed that young subjects had consistently larger pupils than older subjects, for dark adaptation and during all light exposures. Steady-state pupil constriction was greater under blue than green light exposure in both age groups and increased with increasing irradiance. Surprisingly, when expressed in relation to baseline pupil size, no significant age-related differences were observed in pupil constriction. The observed reduction in pupil size in older individuals, both in darkness and during light exposure, may reduce retinal illumination and consequently affect non-visual responses to light. The absence of a significant difference between age groups for relative steady-state pupil constriction suggests that other factors such as tonic, sympathetic control of pupil dilation, rather than light sensitivity per se, account for the observed age difference in pupil size regulation. Compared to other nonvisual functions, the light sensitivity of steady-state pupil constriction appears to remain relatively

  2. ISM Properties of Local Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Diaz-Santos, Tanio; Armus, Lee; Stierwalt, Sabrina; Elbaz, David; Malhotra, Sangeeta

    2015-08-01

    Luminous and Ultra-luminous Infrared Galaxies ((U)LIRGs) represent the most important galaxy population at redshifts z > 1 as they account for more than 50% of all star formation produced in the Universe at those epochs; and encompass what it is called the main-sequence (MS) of star-forming galaxies. Investigating their local counterparts -low luminosity LIRGs- is therefore key to understand the physical properties and phases of their inter-stellar medium (ISM) - a task that is rather challenging in the distant Universe. On the other hand, high-z star-bursting (out of the MS) systems, although small in number, account for a modest yet still significant fraction of the total energy production. Here I present far-IR line emission observations ([CII]158μm, [OI]63μm, [OIII]88μm and [NII]122μm) obtained with Herschel for two large samples of nearby LIRGs: The Great Observatories All-sky LIRG Survey (GOALS), a sample of more than 240 relatively cold LIRGs, and a survey of 30 LIRGs selected to have very warm mid- to far-IR colors, suggestive of an ongoing intense nuclear starburst and/or an AGN. Using photo-dissociation region (PDR) models we derive the basic characteristics of the ISM (ionization intensity and density) for both samples and study differences among systems as a function of AGN activity, merger stage, dust temperature, and compactness of the starburst - parameters that are thought to control the life cycle of galaxies moving in and out of the MS, locally and at high-z.

  3. Luminance compensation for AMOLED displays using integrated MIS sensors

    NASA Astrophysics Data System (ADS)

    Vygranenko, Yuri; Fernandes, Miguel; Louro, Paula; Vieira, Manuela

    2017-05-01

    Active-matrix organic light-emitting diodes (AMOLEDs) are ideal for future TV applications due to their ability to faithfully reproduce real images. However, pixel luminance can be affected by instability of driver TFTs and aging effect in OLEDs. This paper reports on a pixel driver utilizing a metal-insulator-semiconductor (MIS) sensor for luminance control of the OLED element. In the proposed pixel architecture for bottom-emission AMOLEDs, the embedded MIS sensor shares the same layer stack with back-channel etched a Si:H TFTs to maintain the fabrication simplicity. The pixel design for a large-area HD display is presented. The external electronics performs image processing to modify incoming video using correction parameters for each pixel in the backplane, and also sensor data processing to update the correction parameters. The luminance adjusting algorithm is based on realistic models for pixel circuit elements to predict the relation between the programming voltage and OLED luminance. SPICE modeling of the sensing part of the backplane is performed to demonstrate its feasibility. Details on the pixel circuit functionality including the sensing and programming operations are also discussed.

  4. Multifocal electroretinogram: age-related changes for different luminance levels

    PubMed Central

    Gerth, Christina; Garcia, Susan M.; Ma, Lei; Keltner, John L.; Werner, John S.

    2008-01-01

    Background Age-related changes in the first-order multifocal electroretinogram (mfERG) responses were measured for two different luminance levels (200 and 700 cd·m−2). The relative contribution of optical and neural factors to senescent change in response was evaluated. Methods Data were obtained from one eye of each of 71 normal phakic subjects, age 9−80 years. The mfERG responses were recorded with the 7” stimulus-refractor unit (EDI) and VERIS 4.3 using the following protocol: bipolar contact lens, 103 hexagons, consecutive stimulation with 200 and 700 cd·m−2, pupils ≥6 mm, amplification of 105, filter cut-offs at 10 and 300 Hz. Results Age-correlated decreases in amplitude and response density and increases in P1 implicit time were found for both luminance levels. The mean response density (nV·deg−2) was higher for the 700 cd·m−2 stimulus, but the rate of change with age was not significantly different from that obtained with the 200 cd·m−2 stimulus. Implicit time was not significantly different for the two light levels, nor was the rate of change with age. The decrease in response density and the increase in implicit time with age were significant across all retinal regions, dividing the 50 deg stimulus into six concentric rings. Age-related change in response density was greatest for the central retina and decreased with increasing retinal eccentricity. Conclusion Log mfERG response changes linearly as a function of age. Analyses of the effects of reduced ocular media transmission and increased stray light, along with ancillary data obtained from pseudophakes, imply that age-related changes in the mfERG are due to both optical and neural factors. PMID:11935277

  5. Disciplinary Technologies and Pupil Redisposition: School Equipment and Homework Diaries

    ERIC Educational Resources Information Center

    Zaborowski, Katrin U.; Breidenstein, Georg

    2011-01-01

    This paper explores disciplinary technologies and pupil redisposition through school and teacher focus on school equipment and homework diaries. During our field research in two contrasting secondary schools, we experienced the importance of missing school equipment to teacher and school control. We also concluded that forgotten or missing school…

  6. Pupils Talking about Their Learning Mentors: What Can We Learn?

    ERIC Educational Resources Information Center

    Rose, Richard; Doveston, Mary

    2008-01-01

    The use of learning mentors to provide additional support to pupils who experience barriers to learning has become a feature of many schools in recent years. Mentoring places learning within a social context and recognises the necessity to ensure that students feel both comfortable with and in control of the learning process. This paper describes…

  7. Disciplinary Technologies and Pupil Redisposition: School Equipment and Homework Diaries

    ERIC Educational Resources Information Center

    Zaborowski, Katrin U.; Breidenstein, Georg

    2011-01-01

    This paper explores disciplinary technologies and pupil redisposition through school and teacher focus on school equipment and homework diaries. During our field research in two contrasting secondary schools, we experienced the importance of missing school equipment to teacher and school control. We also concluded that forgotten or missing school…

  8. Properties of artificial neurons that report lightness based on accumulated experience with luminance.

    PubMed

    Morgenstern, Yaniv; Rukmini, Dhara V; Monson, Brian B; Purves, Dale

    2014-01-01

    The responses of visual neurons in experimental animals have been extensively characterized. To ask whether these responses are consistent with a wholly empirical concept of visual perception, we optimized simple neural networks that responded according to the cumulative frequency of occurrence of local luminance patterns in retinal images. Based on this estimation of accumulated experience, the neuron responses showed classical center-surround receptive fields, luminance gain control and contrast gain control, the key properties of early level visual neurons determined in animal experiments. These results imply that a major purpose of pre-cortical neuronal circuitry is to contend with the inherently uncertain significance of luminance values in natural stimuli.

  9. Moderately luminous Type II supernovae

    NASA Astrophysics Data System (ADS)

    Inserra, C.; Pastorello, A.; Turatto, M.; Pumo, M. L.; Benetti, S.; Cappellaro, E.; Botticella, M. T.; Bufano, F.; Elias-Rosa, N.; Harutyunyan, A.; Taubenberger, S.; Valenti, S.; Zampieri, L.

    2013-07-01

    Context. Core-collapse Supernovae (CC-SNe) descend from progenitors more massive than about 8 M⊙. Because of the young age of the progenitors, the ejecta may eventually interact with the circumstellar medium (CSM) via highly energetic processes detectable in the radio, X-ray, ultraviolet (UV) and, sometimes, in the optical domains. Aims: In this paper we present ultraviolet, optical and near infrared observations of five Type II SNe, namely SNe 2009dd, 2007pk, 2010aj, 1995ad, and 1996W. Together with few other SNe they form a group of moderately luminous Type II events. We investigate the photometric similarities and differences among these bright objects. We also attempt to characterise them by analysing the spectral evolutions, in order to find some traces of CSM-ejecta interaction. Methods: We collected photometry and spectroscopy with several telescopes in order to construct well-sampled light curves and spectral evolutions from the photospheric to the nebular phases. Both photometry and spectroscopy indicate a degree of heterogeneity in this sample. Modelling the data of SNe 2009dd, 2010aj and 1995ad allows us to constrain the explosion parameters and the properties of the progenitor stars. Results: The light curves have luminous peak magnitudes (-16.95 < MB < -18.70). The ejected masses of 56Ni for three SNe span a wide range of values (2.8 × 10-2 M⊙ < M(56Ni)< 1.4 × 10-1 M⊙), while for a fourth (SN 2010aj) we could determine a stringent upper limit (7 × 10-3 M⊙). Clues of interaction, such as the presence of high velocity (HV) features of the Balmer lines, are visible in the photospheric spectra of SNe 2009dd and 1996W. For SN 2007pk we observe a spectral transition from a Type IIn to a standard Type II SN. Modelling the observations of SNe 2009dd, 2010aj and 1995ad with radiation hydrodynamics codes, we infer kinetic plus thermal energies of about 0.2-0.5 foe, initial radii of 2-5 × 1013 cm and ejected masses of ~5.0-9.5 M⊙. Conclusions: These

  10. Pupil fluctuations track rapid changes in adrenergic and cholinergic activity in cortex

    PubMed Central

    Reimer, Jacob; McGinley, Matthew J; Liu, Yang; Rodenkirch, Charles; Wang, Qi; McCormick, David A; Tolias, Andreas S

    2016-01-01

    Rapid variations in cortical state during wakefulness have a strong influence on neural and behavioural responses and are tightly coupled to changes in pupil size across species. However, the physiological processes linking cortical state and pupil variations are largely unknown. Here we demonstrate that these rapid variations, during both quiet waking and locomotion, are highly correlated with fluctuations in the activity of corticopetal noradrenergic and cholinergic projections. Rapid dilations of the pupil are tightly associated with phasic activity in noradrenergic axons, whereas longer-lasting dilations of the pupil, such as during locomotion, are accompanied by sustained activity in cholinergic axons. Thus, the pupil can be used to sensitively track the activity in multiple neuromodulatory transmitter systems as they control the state of the waking brain. PMID:27824036

  11. Neural Correlates of Fast Pupil Dilation in Nonhuman Primates: Relation to Behavioral Performance and Cognitive Workload

    PubMed Central

    Hampson, R.E.; Opris, Ioan; Deadwyler, S.A.

    2010-01-01

    Pupil dilation in humans has been previously shown to correlate with cognitive workload, whereby increased frequency of dilation is associated with increased degree of difficulty of a task. It has been suggested that frontal oculomotor brain areas control cognitively-related pupil dilations, but this has not been confirmed due to lack of animal models of cognitive workload and task-related pupil dilation. This is the first report of a wavelet analysis applied to continuous measures of pupil size used to detect the onset of abrupt pupil dilations and the frequency of those dilations in nonhuman primates (NHPs) performing a trial-unique delayed match to sample (DMS) task. An additional unique finding shows that electrophysiological recordings in the same animals revealed correlated firing of neurons in frontal cortex with different components of pupil dilation during task performance. It is further demonstrated that the frequency of fast pupil dilations (but not rate of eye movements) correlated with cognitive workload during task performance. Such correlations suggest that frontal neuron encoding of pupil dilation provides critical feedback to other brain areas involved in the processing of complex visual information. PMID:20226215

  12. Multi-level aspects of social cohesion of secondary schools and pupils' feelings of safety.

    PubMed

    Mooij, Ton; Smeets, Ed; de Wit, Wouter

    2011-09-01

    BACKGROUND. School safety and corresponding feelings of both pupils and school staff are beginning to receive more and more attention. The social cohesion characteristics of a school may be useful in promoting feelings of safety, particularly in pupils. AIMS. To conceptualize theoretically, and check empirically a two-level model of social cohesion between and within schools, in order to explain a pupil's feelings of safety at school. SAMPLES. Data were collected aided by a national Dutch survey in secondary education carried out via the Internet. In 2008, digital questionnaires were completed by about 78,800 pupils, 6,200 teachers and educational support staff, and 600 school managers. METHODS. Data were checked for reliability and representativity. Social cohesion was indicated by self-reported measures of individual pupils and by aggregating scale and item scores of school managers, teachers, and other support staff within schools. Multi-level analysis using individual pupil data and school-level data was performed using MLwiN. RESULTS. A pupil's age, educational attainment level, experience of mild physical violence, prosocial rules of conduct and joint control of these rules, and school measures against playing truant, show positive influences on a pupil's feelings of safety at school. Negative influences are exerted by not feeling most at home in The Netherlands, peers taking drugs and weapons into school, and by experiencing social violence, severe physical violence, and sexual violence. Negative school effects exist simultaneously in severe physical violence experienced by teachers and other staff, and in curriculum differentiation applied by teachers and other staff; a positive school effect is school size. Some interaction effects between pupil and school-level variables were explored. CONCLUSIONS. The variance at school level is relatively low compared with the variance at pupil level. However, a much higher percentage of variance at school level than at

  13. Age-related gene expression in luminal epithelial cells is driven by a microenvironment made from myoepithelial cells.

    PubMed

    Miyano, Masaru; Sayaman, Rosalyn W; Stoiber, Marcus H; Lin, Chun-Han; Stampfer, Martha R; Brown, James B; LaBarge, Mark A

    2017-10-09

    Luminal epithelial cells in the breast gradually alter gene and protein expression with age, appearing to lose lineage-specificity by acquiring myoepithelial-like characteristics. We hypothesize that the luminal lineage is particularly sensitive to microenvironment changes, and age-related microenvironment changes cause altered luminal cell phenotypes. To evaluate the effects of different microenvironments on the fidelity of epigenetically regulated luminal and myoepithelial gene expression, we generated a set of lineage-specific probes for genes that are controlled through DNA methylation. Culturing primary luminal cells under conditions that favor myoepithelial propogation led to their reprogramming at the level of gene methylation, and to a more myoepithelial-like expression profile. Primary luminal cells' lineage-specific gene expression could be maintained when they were cultured as bilayers with primary myoepithelial cells. Isogenic stromal fibroblast co-cultures were unable to maintain the luminal phenotype. Mixed-age luminal-myoepithelial bilayers revealed that luminal cells adopt transcription and methylation patterns consistent with the chronological age of the myoepithelial cells. We provide evidence that the luminal epithelial phenotype is exquisitely sensitive to microenvironment conditions, and that states of aging are cell non-autonomously communicated through microenvironment cues over at least one cell diameter.

  14. Dust near luminous ultraviolet stars

    NASA Astrophysics Data System (ADS)

    Henry, Richard C.

    1992-03-01

    More than 700 luminous stars in the infrared astronomical satellite (IRAS) Skyflux plates were examined for the presence of dust heated by a nearby star. This dust may be distinguished from the ubiquitous cool cirrus by its higher temperature and thus enhanced 60 micron emission. More than 120 dust clouds were found around only 106 of the stars with a volume filling factor of 0.006 and an intercloud separation of 46 pc. A region of dust smoothly distributed through the volume of space heated by the star could not be found and hence an upper limit of 0.05 cm-3 is placed on the equivalent gas density in the intercloud regions. The clouds have an average density of 0.22 cm-3 and a radius of 1.9 pc, albeit with wide variations in their properties. Two different scale heights of 140 and 540 pc were found. This was interpreted as evidence for different distributions of dust in and out of the galactic disk.

  15. Dust near luminous ultraviolet stars

    NASA Technical Reports Server (NTRS)

    Henry, Richard C.

    1992-01-01

    More than 700 luminous stars in the infrared astronomical satellite (IRAS) Skyflux plates were examined for the presence of dust heated by a nearby star. This dust may be distinguished from the ubiquitous cool cirrus by its higher temperature and thus enhanced 60 micron emission. More than 120 dust clouds were found around only 106 of the stars with a volume filling factor of 0.006 and an intercloud separation of 46 pc. A region of dust smoothly distributed through the volume of space heated by the star could not be found and hence an upper limit of 0.05 cm(exp -3) is placed on the equivalent gas density in the intercloud regions. The clouds have an average density of 0.22 cm(exp -3) and a radius of 1.9 pc, albeit with wide variations in their properties. Two different scale heights of 140 and 540 pc were found. This was interpreted as evidence for different distributions of dust in and out of the galactic disk.

  16. Dust near luminous ultraviolet stars

    NASA Technical Reports Server (NTRS)

    Henry, Richard C.

    1993-01-01

    This report describes research activities related to the Infrared Astronomical Satellite (IRAS) sky survey. About 745 luminous stars were examined for the presence of interstellar dust heated by a nearby star. The 'cirrus' discovered by IRAS is thermal radiation from interstellar dust at moderate and high galactic latitudes. The IRAS locates the dust which must (at some level) scatter ultraviolet starlight, although it was expected that thermal emission would be found around virtually every star, most stars shown no detectable emission. And the emission found is not uniform. It is not that the star is embedded in 'an interstellar medium', but rather what is found are discrete clouds that are heated by starlight. An exception is the dearth of clouds near the very hottest stars, implying that the very hottest stars play an active role with respect to destroying or substantially modifying the dust clouds over time. The other possibility is simply that the hottest stars are located in regions lacking in dust, which is counter-intuitive. A bibliography of related journal articles is attached.

  17. The Most Luminous Galaxies Found by WISE

    NASA Astrophysics Data System (ADS)

    Eisenhardt, Peter

    2012-08-01

    We have used photometry from NASA's Wide-field Infrared Survey Explorer (WISE) to select an all-sky sample of objects which are extremely luminous. Herschel far-IR follow-up observations of these sources are underway. We find most are brighter than 10 trillion solar luminosities, and about 10% exceed 100 trillion solar luminosities. We request one night with LRIS-ADC to obtain redshifts for 20 candidate WISE Ultra-Luminous IR Galaxies which are targets of the Herschel program. The redshifts are essential to one of the two primary science objectives for WISE: to identify the most luminous galaxies in the Universe.

  18. Optical coherence tomography investigations of ceramic lumineers

    NASA Astrophysics Data System (ADS)

    Fernandes, Luana O.; Graça, Natalia D. R. L.; Melo, Luciana S. A.; Silva, Claudio H. V.; Gomes, Anderson S. L.

    2016-02-01

    Lumineers are veneer laminates used as an alternative for aesthetic dental solutions of the highest quality, but the only current means of its performance assessment is visual inspection. The objective of this study was to use the Optical Coherence Tomography (OCT) technique working in spectral domain to analyze in vivo in a single patient, 14 lumineers 180 days after cementation. It was possible to observe images in various kinds of changes in the cementing line and the laminate. It was concluded that the OCT is an effective and promising method to clinical evaluation of the cementing line in lumineers.

  19. Improving vision by pupil masking

    PubMed Central

    Bonaque-González, Sergio; Ríos-Rodríguez, Susana; López-Gil, Norberto

    2016-01-01

    We propose an alternative solution to improve visual quality by spatially modulating the amplitude of light passing into the eye (related to the eye's transmittance), in contrast to traditional correction of the wavefront phase (related to the local refractive power). Numerical simulations show that masking the aberrated areas at the pupil plane should enhance visual function, especially in highly aberrated eyes. This correction could be implemented in practice using customized contact or intraocular lenses. PMID:27446688

  20. Hemispheric laterality measured in Rembrandt's portraits using pupil diameter and aesthetic verbal judgements.

    PubMed

    Powell, W Ryan; Schirillo, James A

    2011-08-01

    Eckhard Hess claimed that pupils dilate to pleasant images and constrict to unpleasant images. However, his work was confounded since his image's luminances and contrasts across conditions were inconsistent. We overcome this limitation and suggest a new, promising methodology for research in this area. We presented rightward or leftward facing male and female portraits by Rembrandt to observers in either their original or mirror-reversed position. Since emotional content may be expressed differently on each side of the face, we used Rembrandt's portraits since most of his males had their right-cheek exposed and females had their left-cheek exposed. This raises questions regarding the emotional and cognitive significance of such biased positioning. Simultaneously, we measured observers pupil size while asking observers to report how (dis)pleasing they found each image. We found that in viewing male portraits pupil diameter was a function of arousal. That is, larger pupil diameter occurred for images rated both low and high in pleasantness. We discuss these findings in regard to the perceived dominance of males and how emotional expressions may be driven by hemispheric laterality.

  1. Pupil response and attention skills in Down syndrome.

    PubMed

    Angulo-Chavira, Armando Quetzalcóatl; García, Octavio; Arias-Trejo, Natalia

    2017-09-06

    Down syndrome (DS) is characterized by attentional problems. Little is known about the neural correlates of attention problems in DS due to difficulties in evaluation. Pupil dilation, associated with an increase in cognitive load and locus coeruleus-noradrenaline system activity in humans, is a neurophysiological measurement that may help to characterize such problems. The aim of this research was to investigate the link between a phasic pupil dilation response and target detection in people with DS, as compared with a control group with typical development (TD) matched by mental age. Participants performed an "oddball" task by means of an eye-tracker and a series of neuropsychological tests. Although the DS and control group demonstrated similar attentional skills and behavioral performance, the participants with DS showed greater pupil dilation. This result suggests that people with DS expend extra cognitive effort to achieve performance similar to those with TD. This finding is discussed in light of the attentional process in DS and the reliability of pupil dilation measurement in the study of attention and other cognitive processes in DS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Pupil measures of alertness and mental load

    NASA Technical Reports Server (NTRS)

    Backs, Richard W.; Walrath, Larry C.

    1988-01-01

    A study of eight adults given active and passive search tasks showed that evoked pupillary response was sensitive to information processing demands. In particular, large pupillary diameter was observed in the active search condition where subjects were actively processing information relevant to task performance, as opposed to the passive search (control) condition where subjects passively viewed the displays. However, subjects may have simply been more aroused in the active search task. Of greater importance was that larger pupillary diameter, corresponding to longer search time, was observed for noncoded than for color-coded displays in active search. In the control condition, pupil diameter was larger with the color displays. The data indicate potential usefulness of pupillary responses in evaluating the information processing requirements of visual displays.

  3. The impact of a multiple intelligences teaching approach drug education programme on drug refusal skills of Nigerian pupils.

    PubMed

    Nwagu, Evelyn N; Ezedum, Chuks E; Nwagu, Eric K N

    2015-09-01

    The rising incidence of drug abuse among youths in Nigeria is a source of concern for health educators. This study was carried out on primary six pupils to determine the effect of a Multiple Intelligences Teaching Approach Drug Education Programme (MITA-DEP) on pupils' acquisition of drug refusal skills. A programme of drug education based on the Multiple Intelligences Teaching Approach (MITA) was developed. An experimental group was taught using this programme while a control group was taught using the same programme but developed based on the Traditional Teaching Approach. Pupils taught with the MITA acquired more drug refusal skills than those taught with the Traditional Teaching Approach. Urban pupils taught with the MITA acquired more skills than rural pupils. There was no statistically significant difference in the mean refusal skills of male and female pupils taught with the MITA. © The Author(s) 2014.

  4. Pupil Mimicry Correlates With Trust in In-Group Partners With Dilating Pupils.

    PubMed

    Kret, M E; Fischer, A H; De Dreu, C K W

    2015-09-01

    During close interactions with fellow group members, humans look into one another's eyes, follow gaze, and quickly grasp emotion signals. The eye-catching morphology of human eyes, with unique eye whites, draws attention to the middle part, to the pupils, and their autonomic changes, which signal arousal, cognitive load, and interest (including social interest). Here, we examined whether and how these changes in a partner's pupils are processed and how they affect the partner's trustworthiness. Participants played incentivized trust games with virtual partners, whose pupils dilated, remained static, or constricted. Results showed that (a) participants trusted partners with dilating pupils and withheld trust from partners with constricting pupils, (b) participants' pupils mimicked changes in their partners' pupils, and (c) dilation mimicry predicted trust in in-group partners, whereas constriction mimicry did not. We suggest that pupil-contingent trust is in-group bounded and possibly evolved in and because of group life. © The Author(s) 2015.

  5. Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial.

    PubMed

    Stephenson, J M; Strange, V; Forrest, S; Oakley, A; Copas, A; Allen, E; Babiker, A; Black, S; Ali, M; Monteiro, H; Johnson, A M

    Improvement of sex education in schools is a key part of the UK government's strategy to reduce teenage pregnancy in England. We examined the effectiveness of one form of peer-led sex education in a school-based randomised trial of over 8000 pupils. 29 schools were randomised to either peer-led sex education (intervention) or to continue their usual teacher-led sex education (control). In intervention schools, peer educators aged 16-17 years delivered three sessions of sex education to 13-14 year-old pupils from the same schools. Primary outcome was unprotected (without condom) first heterosexual intercourse by age 16 years. Analysis was by intention to treat. By age 16 years, significantly fewer girls reported intercourse in the peer-led arm than in the control arm, but proportions were similar for boys. The proportions of pupils reporting unprotected first sex did not differ for girls (8.4% intervention vs 8.3% control) or for boys (6.2% vs 4.7%). Stratified estimates of the difference between arms were -0.4% (95% CI -3.7% to 2.8%, p=0.79) for girls and -1.4% (-4.4% to 1.6%, p=0.36) for boys. At follow-up (mean age 16.0 years [SD 0.32]), girls in the intervention arm reported fewer unintended pregnancies, although the difference was borderline (2.3% vs 3.3%, p=0.07). Girls and boys were more satisfied with peer-led than teacher-led sex education, but 57% of girls and 32% of boys wanted sex education in single-sex groups. Peer-led sex education was effective in some ways, but broader strategies are needed to improve young people's sexual health. The role of single-sex sessions should be investigated further.

  6. Predicting a Luminous Red Nova

    NASA Astrophysics Data System (ADS)

    Van Noord, Daniel; Molnar, Larry; Kinemuchi, Karen; Steenwyk, Steven; Alexander, Cara; Spedden, Chris; Kobulnicky, Henry

    2016-05-01

    Luminous Red Novae (LRN) are rare transient events believed to be caused by the merger of a main sequence contact binary. Since the discovery of the prototype, V838 Mon, only a handful of LRN events have been observed. Tylenda et al. (2011) analyzed the OGLE data preceding the 2008 Novae of V1309 Sco and found that it exhibited a similar light curve to that of a contact binary with one interesting exception, the orbital period of V1309 Sco showed exponential period change going to zero. Unfortunately the system was discovered to be a binary after the merger, preventing any targeted observations to narrow down how the system entered this unusual state. However the extreme period change observed in V1309 Sco gives us a signature to look for in other contact binaries, allowing the discovery of merger candidates for follow up. We will present an analysis of light curves and spectra of KIC 9832227 (NSVS 5597755) that show it is a contact binary system with a negative period derivative that is becoming more extreme with time. These data span more than 15 years and are taken from the NSVS, ASAS, WASP, and Kepler surveys, with ongoing measurements from the Calvin College Observatory and the Apache Point Observatory. The ongoing period change observed in the system is consistent with the exponential model fit from V1309 Sco and the rate of period change has surpassed that of all other measured contact binaries with the exception of V1309 Sco. If the exponential period decay continues the system will likely merge between 2019 and 2022 resulting in a naked eye nova. If this event occurs, this star will present the unprecedented opportunity to study a LRN progenitor and to follow the evolution of the merger.

  7. Eta Carinae and Other Luminous Blue Variables

    NASA Technical Reports Server (NTRS)

    Corcoran, M. F.

    2006-01-01

    Luminous Blue Variables (LBVs) are believed to be evolved, extremely massive stars close to the Eddington Limit and hence prone to bouts of large-scale, unstable mass loss. I discuss current understanding of the evolutionary state of these objects, the role duplicity may play and known physical characteristics of these stars using the X-ray luminous LBVs Eta Carinae and HD 5980 as test cases.

  8. Simultaneous chromatic and luminance human electroretinogram responses

    PubMed Central

    Parry, Neil R A; Murray, Ian J; Panorgias, Athanasios; McKeefry, Declan J; Lee, Barry B; Kremers, Jan

    2012-01-01

    The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats’ ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post-receptoral pathways that are in operation from the earliest stages of visual processing. PMID:22586211

  9. Ratio model serves suprathreshold color- luminance discrimination

    NASA Astrophysics Data System (ADS)

    Sankeralli, Marcel J.; Mullen, Kathy T.; Hine, Trevor J.

    2002-03-01

    We extended earlier results [J. Opt. Soc. Am. A 16, 2625 (1999)] to examine how the responses of the three postreceptoral mechanisms are combined to subserve discrimination of suprathreshold stimuli. Test thresholds were obtained in the presence of suprathreshold pedestals selected in different quadrants of the red-green/luminance and blue-yellow/luminance planes of cardinal color space. We showed that (1) test threshold was directly proportional to pedestal contrast for pedestal contrasts exceeding five times pedestal contrast threshold, and (2) there were exceptions to this proportionality, notably when the test and pedestal directions were fixed in the cardinal directions. Results support a ratio model of suprathreshold color-luminance discrimination, in which discrimination depends on a ratio of outputs of the postreceptoral mechanisms. We also observed that when test threshold was measured as a function of test color-space direction, masking by the achromatic component of the pedestal was less than that by the chromatic component. In addition, masking by a dark (negative luminance component) pedestal was lower than masking by a light (positive luminance) pedestal of a similar contrast. Our results demonstrated that (1) there is no fundamental difference between discrimination in the isoluminant and in the two chromoluminant cardinal planes, (2) there exists the possibility that discrimination in cardinal directions differs from that in noncardinal (intermediate) directions, and (3) suprathreshold discrimination of luminance differences may be more sensitive than that of chromatic differences for a given suprathreshold pedestal.

  10. The online behavior of pupils with visual impairment: A preliminary report.

    PubMed

    Wrzesińska, Magdalena; Tabała, Klaudia; Stecz, Patryk

    2016-10-01

    Young people with special educational needs are also users of new media. The aim of the study was to determine whether pupils with visual impairment spend more time on Internet use than pupils without visual impairment and whether youngsters from the study group are engaged in behaviors which could increase risk of problematic Internet use. The study is based on a total of 191 pupils: a study group of 66 partially-sighted pupils and a control group comprised 125 pupils who do not have visual impairment. A self-report questionnaire was constructed for the needs of this study. Pupils with visual impairment spent significantly less time on Internet use than their peers from the reference groups. Twice as many pupils from the study group as controls reported no symptoms suggesting potentially problematic Internet use. In addition, the study group more frequently used online social networking services and e-mails or used the Internet for assignments. Little difference exists between students with visual impairment and those without with regard to Internet use. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Pupils as Active Participants: Diamond Ranking as a Tool to Investigate Pupils' Experiences of Classroom Practices

    ERIC Educational Resources Information Center

    Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse

    2015-01-01

    This article is based on a pedagogical action research initiative carried out in a Finnish primary school. Twenty-four 5th grade pupils and their teacher participated in the study. The research initiative was guided by two questions: (1) How do pupils experience their classroom practices? (2) How can pupils participate in the process of developing…

  12. Pupils as Active Participants: Diamond Ranking as a Tool to Investigate Pupils' Experiences of Classroom Practices

    ERIC Educational Resources Information Center

    Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse

    2015-01-01

    This article is based on a pedagogical action research initiative carried out in a Finnish primary school. Twenty-four 5th grade pupils and their teacher participated in the study. The research initiative was guided by two questions: (1) How do pupils experience their classroom practices? (2) How can pupils participate in the process of developing…

  13. [Hygienic requirements for the sizes of furniture for junior pupils].

    PubMed

    Khramtsov, P I; Moldovanov, V V; Sotnikova, E N; Strokina, A N

    2009-01-01

    The paper gives the results of anthropometric surveys in present-day junior pupils. It shows the distribution of junior pupils by the height groups and the ergonomic signs that determine the required functional sizes of furniture for pupils.

  14. Pupil tracking with a Hartmann-Shack wavefront sensor

    NASA Astrophysics Data System (ADS)

    Arines, Justo; Prado, Paula; Bará, Salvador

    2010-05-01

    We present the theoretical background and experimental validation of a pupil tracking method based on measurement of the irradiance centroid of Hartmann-Shack aberrometric images. The experimental setup consists of a Hartmann-Shack (HS) sensor forming over the same camera the images of the eye's pupil and the aberrometric image. The calibration is made by comparing the controlled displacements induced to an artificial eye with the displacements estimated from the centroid of the pupil and of the HS focal plane. The pupil image is also used for validation of the method when operating with human eyes. The experimental results after calibration show a root mean square error of 10.45 μm for the artificial eye and 27, 10, and 6 μm rms for human eyes tested using Hartmann-Shack images, with signal-to-noise ratios of 6, 8, and 11, respectively. The performance of the method is similar to conventional commercial eye trackers. It avoids the need for using separate tracking devices and their associated synchronization problems. This technique can also be used to reprocess present and stored sets of Hartmann-Shack aberrometric images to estimate the ocular movements that occurred during the measurement runs, and, if convenient, to correct the measured aberrations from their influence.

  15. Detection of Changes in Surgical Difficulty: Evidence From Pupil Responses.

    PubMed

    Zheng, Bin; Jiang, Xianta; Atkins, M Stella

    2015-12-01

    Assessing the workload of surgeons requires technology to continuously monitor surgeons' behaviors without interfering with their performance. We investigated the feasibility of using eye-tracking to reveal surgeons' response to increasing task difficulty. A controlled study was conducted in a simulated operating room, where 14 subjects were required to perform a laparoscopic procedure that includes 9 subtasks. The subtasks could be divided into 3 types with different levels of task difficulty, calculated by the index of task difficulty (ID) proposed by Fitts in 1954. Pupillary responses of subjects in performing the procedure were recorded using Tobii eye-tracking equipment. Peak pupil dilation and movement time were compared between subtasks with different IDs as well as between fast moving and slow aiming phases within each subtask. When the task difficulty was increased, task completion time increased. Meanwhile, the subjects' peak pupil size also increased. As the entire procedure was performed continuously, we found that pupil responses were not only affected by the ID in the current subtask but also influenced by subtasks before and after. Decomposing a surgical procedure into meaningful subtasks and examining the surgeon's pupil response to each subtask enables us to identify the challenging steps within a continuous surgical procedure. Psychomotor evidence on surgeon's performance may lead to an innovation for designing a task-specific training curriculum. © The Author(s) 2015.

  16. Pupil tracking with a Hartmann-Shack wavefront sensor.

    PubMed

    Arines, Justo; Prado, Paula; Bará, Salvador

    2010-01-01

    We present the theoretical background and experimental validation of a pupil tracking method based on measurement of the irradiance centroid of Hartmann-Shack aberrometric images. The experimental setup consists of a Hartmann-Shack (HS) sensor forming over the same camera the images of the eye's pupil and the aberrometric image. The calibration is made by comparing the controlled displacements induced to an artificial eye with the displacements estimated from the centroid of the pupil and of the HS focal plane. The pupil image is also used for validation of the method when operating with human eyes. The experimental results after calibration show a root mean square error of 10.45 mum for the artificial eye and 27, 10, and 6 mum rms for human eyes tested using Hartmann-Shack images, with signal-to-noise ratios of 6, 8, and 11, respectively. The performance of the method is similar to conventional commercial eye trackers. It avoids the need for using separate tracking devices and their associated synchronization problems. This technique can also be used to reprocess present and stored sets of Hartmann-Shack aberrometric images to estimate the ocular movements that occurred during the measurement runs, and, if convenient, to correct the measured aberrations from their influence.

  17. Perceived temporal asynchrony between sinusoidally modulated luminance and depth

    PubMed Central

    Žarić, Gojko; Yazdanbakhsh, Arash; Nishina, Shigeaki; De Weerd, Peter; Watanabe, Takeo

    2015-01-01

    Simultaneously presented visual events lead to temporally asynchronous percepts. This has led some researchers to conclude that the asynchronous experience is a manifestation of differences in neural processing time for different visual attributes. Others, however, have suggested that the asynchronous experience is due to differences in temporal markers for changes of different visual attributes. Here, two sets of bars were presented, one to each eye. Either the bars were moving or their luminance was gradually changing. Bars moved horizontally in counterphase at low frequencies along short trajectories and were presented stereoscopically, such that the horizontal movements were perceived as back-and-forth motion on a sagittal plane, or monocularly to a dominant eye, preserving a perception of the horizontal movements on a frontal plane. In a control condition, bars were stationary and their luminance was modulated. The changes in stimulus speed or luminance occurred sinusoidally. When asked to adjust the phase of one stimulus to the other to achieve synchronous perception, participants showed a constant phase offset at the lowest frequencies used. Given the absence of abrupt transitions and the presence of similar gradual turning points in our stimuli to control for attentional effects, it can be concluded that asynchronous percepts in multimodal stimuli may at least in part be a manifestation of difference in neural processing time of visual attributes rather than solely a difference in the temporal markers (transitions versus turning points). PMID:26605842

  18. Temporal characteristics of melanopsin inputs to the human pupil light reflex

    PubMed Central

    Joyce, Daniel S.; Feigl, Beatrix; Cao, Dingcai; Zele, Andrew J.

    2014-01-01

    Rods, cones and melanopsin containing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) operate in concert to regulate pupil diameter. The temporal properties of intrinsic ipRGC signalling are distinct to those of rods and cones, including longer latencies and sustained signalling after light offset. We examined whether the melanopsin mediated post-illumination pupil response (PIPR) and pupil constriction were dependent upon the inter-stimulus interval (ISI) between successive light pulses and the temporal frequency of sinusoidal light stimuli. Melanopsin excitation was altered by variation of stimulus wavelength (464 nm and 638 nm lights) and irradiance (11.4 and 15.2 log photons.cm−2.s−1). We found that 6s PIPR amplitude was independent of ISI and temporal frequency for all melanopsin excitation levels, indicating complete summation. In contrast to the PIPR, the maximum pupil constriction increased with increasing ISI with high and low melanopsin excitation, but time to minimum diameter was slower with high melanopsin excitation only. This melanopsin response to briefly presented pulses (16 and 100 ms) slows the temporal response of the maximum pupil constriction. We also demonstrate that high melanopsin excitation attenuates the phasic peak-trough pupil amplitude compared to conditions with low melanopsin excitation, indicating an interaction between inner and outer retinal inputs to the pupil light reflex. We infer that outer retina summation is important for rapidly controlling pupil diameter in response to short timescale fluctuations in illumination and may occur at two potential sites, one that is presynaptic to extrinsic photoreceptor input to ipRGCs, or another within the pupil control pathway if ipRGCs have differential temporal tuning to extrinsic and intrinsic signalling. PMID:25497360

  19. Temporal characteristics of melanopsin inputs to the human pupil light reflex.

    PubMed

    Joyce, Daniel S; Feigl, Beatrix; Cao, Dingcai; Zele, Andrew J

    2015-02-01

    Rods, cones and melanopsin containing intrinsically photosensitive retinal ganglion cells (ipRGCs) operate in concert to regulate pupil diameter. The temporal properties of intrinsic ipRGC signalling are distinct to those of rods and cones, including longer latencies and sustained signalling after light offset. We examined whether the melanopsin mediated post-illumination pupil response (PIPR) and pupil constriction were dependent upon the inter-stimulus interval (ISI) between successive light pulses and the temporal frequency of sinusoidal light stimuli. Melanopsin excitation was altered by variation of stimulus wavelength (464 nm and 638 nm lights) and irradiance (11.4 and 15.2 log photons cm(-2) s(-1)). We found that 6s PIPR amplitude was independent of ISI and temporal frequency for all melanopsin excitation levels, indicating complete summation. In contrast to the PIPR, the maximum pupil constriction increased with increasing ISI with high and low melanopsin excitation, but time to minimum diameter was slower with high melanopsin excitation only. This melanopsin response to briefly presented pulses (16 and 100 ms) slows the temporal response of the maximum pupil constriction. We also demonstrate that high melanopsin excitation attenuates the phasic peak-trough pupil amplitude compared to conditions with low melanopsin excitation, indicating an interaction between inner and outer retinal inputs to the pupil light reflex. We infer that outer retina summation is important for rapidly controlling pupil diameter in response to short timescale fluctuations in illumination and may occur at two potential sites, one that is presynaptic to extrinsic photoreceptor input to ipRGCs, or another within the pupil control pathway if ipRGCs have differential temporal tuning to extrinsic and intrinsic signalling.

  20. The Voice of the Pupils: An Experimental Comparison of Decisions Made by Elected Pupil Councils, Pupils in Referenda, and Teaching Staff

    ERIC Educational Resources Information Center

    Gilljam, Mikael; Esaiasson, Peter; Lindholm, Torun

    2010-01-01

    This article tests whether the form of decision-making used in school environments affects pupils' views on the legitimacy of the decisions made, and of the decision-making procedure. Building on political science theory on democratic decision-making, it compares pupils' reactions towards decisions made by pupil councils, by pupils via referendum,…

  1. The Voice of the Pupils: An Experimental Comparison of Decisions Made by Elected Pupil Councils, Pupils in Referenda, and Teaching Staff

    ERIC Educational Resources Information Center

    Gilljam, Mikael; Esaiasson, Peter; Lindholm, Torun

    2010-01-01

    This article tests whether the form of decision-making used in school environments affects pupils' views on the legitimacy of the decisions made, and of the decision-making procedure. Building on political science theory on democratic decision-making, it compares pupils' reactions towards decisions made by pupil councils, by pupils via referendum,…

  2. "The Joy of Reading"--An Intervention Program to Increase Reading Motivation for Pupils with Learning Disabilities

    ERIC Educational Resources Information Center

    Tovli, Esther

    2014-01-01

    This study aimed to examine the effect of an intensive reading intervention on reading motivation. The intervention program, ("Joy of Reading"), was implemented in six 2nd grade special education classes for pupils with learning disabilities, compared to a control group (n = 108 pupils in total). The intervention program was created…

  3. Rhodopsin and Melanopsin Contributions to the Early Redilation Phase of the Post-Illumination Pupil Response (PIPR)

    PubMed Central

    Adhikari, Prakash; Feigl, Beatrix; Zele, Andrew J.

    2016-01-01

    Melanopsin expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) entirely control the post-illumination pupil response (PIPR) from 6 s post-stimulus to the plateau during redilation after light offset. However, the photoreceptor contributions to the early redilation phase of the PIPR (< 6 s post-stimulus) have not been reported. Here, we evaluated the photoreceptor contributions to the early phase PIPR (0.6 s to 5.0 s) by measuring the spectral sensitivity of the criterion PIPR amplitude in response to 1 s light pulses at five narrowband stimulus wavelengths (409, 464, 508, 531 and 592 nm). The retinal irradiance producing a criterion PIPR was normalised to the peak and fitted by either a single photopigment nomogram or the combined melanopsin and rhodopsin spectral nomograms with the +L+M cone photopic luminous efficiency (Vλ) function. We show that the PIPR spectral sensitivity at times ≥ 1.7 s after light offset is best described by the melanopsin nomogram. At times < 1.7 s, the peak PIPR sensitivity shifts to longer wavelengths (range: 482 to 498 nm) and is best described by the combined photoreceptor nomogram, with major contributions from melanopsin and rhodopsin. This first report of melanopsin and rhodopsin contributions to the early phase PIPR is in line with the electrophysiological findings of ipRGC and rod signalling after the cessation of light stimuli and provides a cut-off time for isolating photoreceptor specific function in healthy and diseased eyes. PMID:27548480

  4. Pupil Personnel Services: Statement of Functions.

    ERIC Educational Resources Information Center

    Cardinale, Anthony

    This statement of function for pupil personnel services (PPS) in the Department of Defense Dependents Schools (DDDS) focuses on the support role of pupil personnel workers. General, program, and specific functions of school counselors and psychologists, social workers, educational prescriptionists, school health nurses, and resident hall advisors…

  5. Secondary Modern Schools: Are Their Pupils Disadvantaged?

    ERIC Educational Resources Information Center

    Levacic, Rosalind; Marsh, Alan J.

    2007-01-01

    There are still 10 English local educational authorities (LEAs) that are wholly selective and a further 10 with some grammar and secondary modern schools. This article examines the academic performance of pupils in secondary modern schools and the funding of these schools using national data sets matching pupils' performance at Key Stage 2 and…

  6. Primary Pupils' Preconceptions about Child Prenatal Development

    ERIC Educational Resources Information Center

    Zoldosova, Kristina; Prokop, Pavol

    2007-01-01

    The research deals a problem of primary pupils' preconceptions about a child prenatal development. Even the pupils cannot experience the phenomenon and can get only mediate information; their idea about the prenatal development is quite well constructed. The quality of the preconceptions depends mainly upon variety of informational sources kept at…

  7. Key Stage 3 Pupils' Perception of Music

    ERIC Educational Resources Information Center

    Button, Stuart

    2006-01-01

    The key aim of the research summarised in this article was to examine pupils' perception of music and to determine whether or not these perceptions were the same for both female and male pupils. The empirical enquiry consisted of the administration of a questionnaire to six secondary schools in the north-east of England followed by semi-structured…

  8. Pupil Master Record System: History and Outlook.

    ERIC Educational Resources Information Center

    Miller, J. J.; Skees, W. D.

    The Montgomery County, Maryland Public Schools, working with Operations Research, Incorporated, developed a Pupil Master File (PLMF). PLMF is one of the several applications included within the Pupil Subsystem of the district's overall computerized School Information System. The PLMF is designed to provide: 1) a master file which enables users to…

  9. Pupil Absenteeism and the Educational Psychologist

    ERIC Educational Resources Information Center

    Carroll, H. C. M.

    2015-01-01

    From a review of the literature, it is concluded that (i) each form of pupil absenteeism relates to a heterogeneous group of children; (ii) because of such heterogeneity, those who are involved in assessment and intervention in relation to pupil absenteeism are faced with a demanding task; (iii) as a consequence of their education and training,…

  10. Secondary Modern Schools: Are Their Pupils Disadvantaged?

    ERIC Educational Resources Information Center

    Levacic, Rosalind; Marsh, Alan J.

    2007-01-01

    There are still 10 English local educational authorities (LEAs) that are wholly selective and a further 10 with some grammar and secondary modern schools. This article examines the academic performance of pupils in secondary modern schools and the funding of these schools using national data sets matching pupils' performance at Key Stage 2 and…

  11. Primary Pupils' Preconceptions about Child Prenatal Development

    ERIC Educational Resources Information Center

    Zoldosova, Kristina; Prokop, Pavol

    2007-01-01

    The research deals a problem of primary pupils' preconceptions about a child prenatal development. Even the pupils cannot experience the phenomenon and can get only mediate information; their idea about the prenatal development is quite well constructed. The quality of the preconceptions depends mainly upon variety of informational sources kept at…

  12. Pupils' Voice: "My Primary School Teacher''

    ERIC Educational Resources Information Center

    Alkan, Vesile

    2013-01-01

    This study aims to explore pupils' views on how a teacher should be and the reasons for their decisions. Based on qualitative research design, focus group interviews were done with ten 5th graders from a public primary school in Turkey. These pupils were asked the following questions: "how do you think a teacher should be?" and "why…

  13. Patterns of Absence and Pupil Achievement.

    ERIC Educational Resources Information Center

    Monk, David H.; Ibrahim, Mohd Ariffin

    1984-01-01

    Various aspects of absentee patterns were compared with pupils' performances on a standardized ninth grade algebra examination. Results indicated that patterns of absence, in addition to gross quantity of absence, are related to pupils' performances. Moreover, results indicate that attending students' test score performances are sensitive to…

  14. Ability of Slovakian Pupils to Identify Birds

    ERIC Educational Resources Information Center

    Prokop, Pavol; Rodak, Rastislav

    2009-01-01

    A pupil's ability to identify common organisms is necessary for acquiring further knowledge of biology. We investigated how pupils were able to identify 25 bird species following their song, growth habits, or both features presented simultaneously. Just about 19% of birds were successfully identified by song, about 39% by growth habit, and 45% of…

  15. Ability of Slovakian Pupils to Identify Birds

    ERIC Educational Resources Information Center

    Prokop, Pavol; Rodak, Rastislav

    2009-01-01

    A pupil's ability to identify common organisms is necessary for acquiring further knowledge of biology. We investigated how pupils were able to identify 25 bird species following their song, growth habits, or both features presented simultaneously. Just about 19% of birds were successfully identified by song, about 39% by growth habit, and 45% of…

  16. NAT THE RAT - PUPIL'S BOOK. (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    ROJAS, PAULINE M.; AND OTHERS

    THE EXPERIMENTAL EDITION OF "NAT THE RAT" REPRESENTS LEVEL TWO OF THE "MIAMI LINGISTIC READERS" DESIGNED TO BE USED IN TEACHING BEGINNING READING TO PUPILS WHOSE PRESCHOOL LANGUAGE WAS OTHER THAN ENGLISH. THE FIVE MAJOR CHARACTERS IN THE STORY ARE INTRODUCED ON THE FIRST FIVE PAGES OF THE PUPILS' BOOK. ILLUSTRATIONS (BLACK AND…

  17. Pupils' Representations of Models of Water.

    ERIC Educational Resources Information Center

    Pereira, Mariana P.; Pestana, Maria Elisa M.

    1991-01-01

    The pencil-and-paper assignment "Represent water in its three states using a model" was given to pupils (n=227) from eighth to twelfth grades. The findings show that the dominant model used was the space filling type; movement of particles was indicated by a minority of pupils; size of the model changed when drawn in different states.…

  18. Planning and Analysis Needs for Pupil Transportation.

    ERIC Educational Resources Information Center

    Stanley Associates, Edmonton (Alberta).

    This study was initiated to determine the pupil transportation planning and analysis needs of Alberta school systems and, based on these needs, to define an action plan for the development of an information or analytical package that would assist school boards with their pupil transportation activities. Based on the data collected from indepth…

  19. Turkish Primary School Pupils' Views on Punishment

    ERIC Educational Resources Information Center

    Aydin, Bahri

    2010-01-01

    Teachers meet with unwanted behavior when they are acting as facilitators of the learning process and they resort to certain tactics to deal with them. One of these tactics is punishment. This study aimed to identify the views held by Turkish primary school pupils on punishment. According to the results of the study, pupils were punished for…

  20. NAT THE RAT - PUPIL'S BOOK. (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    ROJAS, PAULINE M.; AND OTHERS

    THE EXPERIMENTAL EDITION OF "NAT THE RAT" REPRESENTS LEVEL TWO OF THE "MIAMI LINGISTIC READERS" DESIGNED TO BE USED IN TEACHING BEGINNING READING TO PUPILS WHOSE PRESCHOOL LANGUAGE WAS OTHER THAN ENGLISH. THE FIVE MAJOR CHARACTERS IN THE STORY ARE INTRODUCED ON THE FIRST FIVE PAGES OF THE PUPILS' BOOK. ILLUSTRATIONS (BLACK AND…

  1. Pupil size variations correlate with physical effort perception.

    PubMed

    Zénon, Alexandre; Sidibé, Mariam; Olivier, Etienne

    2014-01-01

    It has long been established that the pupil diameter increases during mental activities in proportion to the difficulty of the task at hand. However, it is still unclear whether this relationship between the pupil size and effort applies also to physical effort. In order to address this issue, we asked healthy volunteers to perform a power grip task, at varied intensity, while evaluating their effort both implicitly and explicitly, and while concurrently monitoring their pupil size. Each trial started with a contraction of imposed intensity, under the control of a continuous visual feedback. Upon completion of the contraction, participants had to choose whether to replicate, without feedback, the first contraction for a variable monetary reward, or whether to skip this step and go directly to the next trial. The rate of acceptance of effort replication and the amount of force exerted during the replication were used as implicit measures of the perception of the effort exerted during the first contraction. In addition, the participants were asked to rate on an analog scale, their explicit perception of the effort for each intensity condition. We found that pupil diameter increased during physical effort and that the magnitude of this response reflected not only the actual intensity of the contraction but also the subjects' perception of the effort. This finding indicates that the pupil size signals the level of effort invested in a task, irrespective of whether it is physical or mental. It also helps refining the potential brain circuits involved since the results of the current study imply a convergence of mental and physical effort information at some level along this pathway.

  2. The Effect of Unilateral Mean Luminance on Binocular Combination in normal and amblyopic vision

    PubMed Central

    Zhou, Jiawei; Jia, Wuli; Huang, Chang-Bing; Hess, Robert F.

    2013-01-01

    Luminance plays a modulating role in the processes of several visual tasks, which in turn provides significant information for the understanding of visual processing. Here, using a binocular phase combination paradigm, we studied the effect of unilateral changes in mean luminance on binocular combination in both normal and amblyopic vision. We found, in normal observers, attenuation of one eye's stimulus luminance with neutral density filters produces binocular phase combination similar to those of amblyopic subjects. Correspondingly, in amblyopic observers, reduction of the fellow eye's stimulus luminance produces binocular phase combination similar to those of normal subjects. These phenomena could be explained by an attenuated contribution of the filtered eye to the binocular phase percept due to reduced gain-control. The findings have major implications both for the study of binocular combination and for amblyopia treatment. PMID:23774670

  3. Characterization of halogen lamps as secondary standard of luminous flux

    NASA Astrophysics Data System (ADS)

    Marques, A. A. R.; Sanchez, O., Jr.; Ferreira, A. F. G., Jr.

    2011-09-01

    This work presents a study of lamps characterization concerning its lamp output, current and voltage drift during seasoning and regarding the use of theses lamps as luminous flux secondary standard. The 200W halogen lamps are seasoned for 30 hours and during the seasoning period the relative drift of the lamp illuminance, current and voltage are measured at each 3 minutes. The illuminance is measured using a photometer with detector head, the lamp voltage is measured using a 6.5 digits voltmeter and the current is measured using a 6.5 digits voltmeter and 0.1 Ohms standard resistor. The lamp current is controlled by a calibrated current power source with stability better than 1 mA. To reduce the stray light, baffles are positioned between the lamp and the detector head. The alignment of experimental assembly is made by a He-Ne Laser. Data of illuminance, current and voltage is acquired by software built in Labview database. Among the 5 lamps seasoned, the best result presents the variation of illuminance of 0.04% per hour. This lamp is chosen to become the secondary standard and its luminous flux is measured using an Ulbricht integrating sphere. This method allows the laboratory to create secondary standard of luminous flux for its routine test and measurements and to supply theses standards for Brazilian industry.

  4. Current limitations about the cleaning of luminal endoscopes.

    PubMed

    Hervé, R; Keevil, C W

    2013-01-01

    The presence and potential build-up of patient material such as proteins in endoscope lumens can have significant implications, including toxic reactions, device damage, inadequate disinfection/sterilization, increased risk of biofilm development and potential transmission of pathogens. To evaluate potential protein deposition and removal in the channels of flexible luminal endoscopes during a simple contamination/cleaning cycle. The level of contamination present on disposable endoscopy forceps which come into contact with the lumen of biopsy channels was evaluated. Following observations in endoscopy units, factors influencing protein adsorption inside luminal endoscope channels and the action of current initial cleaning techniques were evaluated using a proteinaceous test soil and very sensitive fluorescence epimicroscopy. Disposable endoscope accessories appear to be likely to contribute to the contamination of lumens, and were useful indicators of the amount of proteinaceous soil transiting through the channels of luminal endoscopes. Enzymatic cleaning according to the manufacturer's recommendations and brushing of the channels were ineffective at removing all proteinaceous residues from new endoscope channels after a single contamination. Rinsing immediately after contamination only led to a slight improvement in decontamination outcome. Limited action of current decontamination procedures and the lack of applicable quality control methods to assess the cleanliness of channels between patients contribute to increasing the risk of cross-infection of potentially harmful micro-organisms and molecules during endoscopy procedures. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  5. The Impact of Auditory Spectral Resolution on Listening Effort Revealed by Pupil Dilation

    PubMed Central

    Winn, Matthew B.; Edwards, Jan R.; Litovsky, Ruth Y.

    2014-01-01

    Objectives This study measured the impact of auditory spectral resolution on listening effort. Systematic degradation in spectral resolution was hypothesized to elicit corresponding systematic increases in pupil dilation, consistent with the notion of pupil dilation as a marker of cognitive load. Design Spectral resolution of sentences was varied with 2 different vocoders: (1) a noise channel vocoder with a variable number of spectral channels; and (2) a vocoder designed to simulate front-end processing of a cochlear implant, including peak-picking channel selection with variable synthesis filter slopes to simulate spread of neural excitation. Pupil dilation was measured after subject-specific luminance adjustment and trial-specific baseline measures. Mixed-effects growth curve analysis was used to model pupillary responses over time. Results For both types of vocoder, pupil dilation grew with each successive degradation in spectral resolution. Within each condition, pupillary responses were not related to intelligibility scores, and the effect of spectral resolution on pupil dilation persisted even when only analyzing trials in which responses were 100% correct. Conclusions Intelligibility scores alone were not sufficient to quantify the effort required to understand speech with poor resolution. Degraded spectral resolution results in increased effort required to understand speech, even when intelligibility is at 100%. Pupillary responses were a sensitive and highly granular measurement to reveal changes in listening effort. Pupillary responses might potentially reveal the benefits of aural prostheses that are not captured by speech intelligibility performance alone, as well as the disadvantages that are overcome by increased listening effort. PMID:25654299

  6. Experimental demonstration of binary shaped pupil mask coronagraphs for telescopes with obscured pupils

    NASA Astrophysics Data System (ADS)

    Haze, Kanae; Enya, Keigo; Abe, Lyu; Takahashi, Aoi; Kotani, Takayuki; Yamamuro, Tomoyasu

    2015-04-01

    We present the fabrication and experimental demonstration of three free-standing binary shaped pupil mask coronagraphs, which are applicable for telescopes with partially obscured pupils. Three masks, designed to be complementary (labeled Mask-A, Mask-B, and Mask-C), were formed in 5 μm thick nickel. The design of Mask-A is based on a one-dimensional barcode mask. The design principle of Mask-B is similar, but has a smaller inner working angle and a lower contrast than Mask-A. Mask-C is based on a concentric ring mask and provides the widest dark region and a symmetric point spread function. Mask-A and Mask-C were both designed to produce a flexibly tailored dark region (i.e., non-uniform contrast). The contrast was evaluated using a light source comprising a broadband super-luminescent light-emitting diode with a center wavelength of 650 nm, and the measurements were carried out in a large vacuum chamber. Active wavefront control was not applied in this work. The coronagraphic images obtained by experiment were mostly consistent with the designs. The contrast of Mask-A within the ranges 3.3-8 λ/D and 8-12 λ/D was ˜ 10-4-10-7 and ˜ 10-7, respectively, where λ is the wavelength and D is the pupil diameter. The contrast of Mask-B was ˜ 10-4 and that of Mask-C over an extended field of view (5-25 λ/D) was ˜ 10-5-10-6. The effect of tilting the masks was investigated, and found to be irrelevant at the ˜ 10-7 contrast level. Therefore the masks can be tilted to avoid ghosting. These high-contrast free-standing masks have the potential to enable coronagraphic imaging over a wide wavelength range using both ground-based and space-borne general-purpose telescopes with pupil structures not specifically designed for coronagraphy.

  7. Pupil diameter predicts changes in the exploration-exploitation trade-off: evidence for the adaptive gain theory.

    PubMed

    Jepma, Marieke; Nieuwenhuis, Sander

    2011-07-01

    The adaptive regulation of the balance between exploitation and exploration is critical for the optimization of behavioral performance. Animal research and computational modeling have suggested that changes in exploitative versus exploratory control state in response to changes in task utility are mediated by the neuromodulatory locus coeruleus-norepinephrine (LC-NE) system. Recent studies have suggested that utility-driven changes in control state correlate with pupil diameter, and that pupil diameter can be used as an indirect marker of LC activity. We measured participants' pupil diameter while they performed a gambling task with a gradually changing payoff structure. Each choice in this task can be classified as exploitative or exploratory using a computational model of reinforcement learning. We examined the relationship between pupil diameter, task utility, and choice strategy (exploitation vs. exploration), and found that (i) exploratory choices were preceded by a larger baseline pupil diameter than exploitative choices; (ii) individual differences in baseline pupil diameter were predictive of an individual's tendency to explore; and (iii) changes in pupil diameter surrounding the transition between exploitative and exploratory choices correlated with changes in task utility. These findings provide novel evidence that pupil diameter correlates closely with control state, and are consistent with a role for the LC-NE system in the regulation of the exploration-exploitation trade-off in humans.

  8. SUB-LUMINOUS {gamma}-RAY PULSARS

    SciTech Connect

    Romani, R. W.; Kerr, M.; Craig, H. A.; Johnston, S.; Cognard, I.; Smith, D. A.

    2011-09-01

    Most pulsars observed by the Fermi Large Area Telescope have {gamma}-ray luminosities scaling with spin-down power E-dot as L{sub {gamma}}{approx}(E-dot x 10{sup 33} erg s{sup -1}){sup 1/2}. However, there exist one detection and several upper limits an order of magnitude or more fainter than this trend. We describe these 'sub-luminous' {gamma}-ray pulsars and discuss the case for this being an orientation effect. Of the 12 known young radio pulsars with E-dot >10{sup 34} erg s{sup -1} and d {<=} 2 kpc several are substantially sub-luminous. The limited available geometrical constraints favor aligned geometries for these pulsars, although no one case for alignment is compelling. In this scenario GeV emission detected from such sub-luminous pulsars can be due to a lower altitude, lower-power accelerator gap.

  9. Sub-luminous γ-ray pulsars

    SciTech Connect

    Romani, R. W.; Kerr, M.; Craig, H. A.; Johnston, S.; Cognard, I.; Smith, D. A.

    2011-08-17

    Here, most pulsars observed by the Fermi Large Area Telescope have γ-ray luminosities scaling with spin-down power ${\\dot{E}}$ as $L_\\gamma \\approx ({\\dot{E}}\\, \\times \\, 10^{33}\\,{\\rm erg \\,s^{-1}})^{1/2}$. However, there exist one detection and several upper limits an order of magnitude or more fainter than this trend. We describe these "sub-luminous" γ-ray pulsars and discuss the case for this being an orientation effect. Of the 12 known young radio pulsars with ${\\dot{E}}>10^{34}\\, {\\rm erg\\,s^{-1}}$ and d ≤ 2 kpc several are substantially sub-luminous. The limited available geometrical constraints favor aligned geometries for these pulsars, although no one case for alignment is compelling. In this scenario GeV emission detected from such sub-luminous pulsars can be due to a lower altitude, lower-power accelerator gap.

  10. Retinal imaging system with adaptive optics enhanced with pupil tracking

    NASA Astrophysics Data System (ADS)

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Vabre, Laurent; Dainty, Chris

    2011-03-01

    A compact retinal camera with adaptive optics which was designed for clinical practice was used to test a new adaptive optics control algorithm to correct for the angular ray deviations of a model eye. The new control algorithm is based on pupil movements rather than the measurement of the slopes of the wavefront with an optoelectronic sensor. The method for the control algorithm was based on the hypothesis that majority of the changes of the aberrations of the eye are due to head and eye movements and it is possible to correct for the aberrations of the eye by shifting the paraxial correction according to the new position of the pupil. Since the fixational eye movements are very small, the eye movements are assumed to be translational rather than rotational. Using the new control algorithm it was possible to simulate the aberrations of the moving model eye based on pupil tracking. The RMS of the residual wavefront error of the simulation had a magnitude similar to the RMS of the residual wavefront error of the adaptive optics correction based on optoelectronic sensor for angular ray deviations. If our hypothesis is true and other factors such as the tear film or the crystalline lens fluctuations do not cause changes in the aberrations of the eye as much as motion does, the method is expected to work in vivo as it did for a model eye which had no intrinsic factors that cause aberration changes.

  11. Influence of background size, luminance and eccentricity on different adaptation mechanisms.

    PubMed

    Gloriani, Alejandro H; Matesanz, Beatriz M; Barrionuevo, Pablo A; Arranz, Isabel; Issolio, Luis; Mar, Santiago; Aparicio, Juan A

    2016-08-01

    Mechanisms of light adaptation have been traditionally explained with reference to psychophysical experimentation. However, the neural substrata involved in those mechanisms remain to be elucidated. Our study analyzed links between psychophysical measurements and retinal physiological evidence with consideration for the phenomena of rod-cone interactions, photon noise, and spatial summation. Threshold test luminances were obtained with steady background fields at mesopic and photopic light levels (i.e., 0.06-110cd/m(2)) for retinal eccentricities from 0° to 15° using three combinations of background/test field sizes (i.e., 10°/2°, 10°/0.45°, and 1°/0.45°). A two-channel Maxwellian view optical system was employed to eliminate pupil effects on the measured thresholds. A model based on visual mechanisms that were described in the literature was optimized to fit the measured luminance thresholds in all experimental conditions. Our results can be described by a combination of visual mechanisms. We determined how spatial summation changed with eccentricity and how subtractive adaptation changed with eccentricity and background field size. According to our model, photon noise plays a significant role to explain contrast detection thresholds measured with the 1/0.45° background/test size combination at mesopic luminances and at off-axis eccentricities. In these conditions, our data reflect the presence of rod-cone interaction for eccentricities between 6° and 9° and luminances between 0.6 and 5cd/m(2). In spite of the increasing noise effects with eccentricity, results also show that the visual system tends to maintain a constant signal-to-noise ratio in the off-axis detection task over the whole mesopic range.

  12. Mesopic luminance assessed with minimum motion photometry.

    PubMed

    Raphael, Sabine; MacLeod, Donald I A

    2011-08-25

    We measured the relative contribution of rods and cones to luminance across a range of photopic, mesopic, and scotopic adaptation levels and at various retinal eccentricities. We isolated the luminance channel by setting motion-based luminance nulls (minimum motion photometry) using annular stimuli. Luminance nulls between differently colored stimuli require equality in a weighted sum of rod and cone excitations. The relative cone weight increases smoothly from the scotopic range, where rods dominate, to photopic levels, where rod influence becomes negligible. The change from rod to cone vision does not occur uniformly over the visual field. The more peripheral the stimulus location, the higher is the light level required for cones to participate strongly. The relative cone contribution can be described by a sigmoid function of intensity, with two parameters that each depend on the eccentricity and spatial frequency of the stimulus. One parameter determines the "meso-mesopic" luminance--the center of the mesopic range, at which rod and cone contributions are balanced. This increases with eccentricity, reflecting an increase in the meso-mesopic luminance from 0.04 scotopic cd/m(2) at 2° eccentricity to 0.44 scotopic cd/m(2) at 18°. The second parameter represents the slope of the log-log threshold-versus-intensity curve (TVI curve) for rod vision. This parameter inversely scales the width of the mesopic range and increases only slightly with eccentricity (from 0.73 at 2° to 0.78 for vision at 18° off-axis).

  13. Specific micro-RNA expression patterns distinguish the basal and luminal subtypes of muscle-invasive bladder cancer

    PubMed Central

    Ochoa, Andrea E.; Choi, Woonyoung; Su, Xiaoping; Siefker-Radtke, Arlene; Czerniak, Bogdan; Dinney, Colin; McConkey, David J.

    2016-01-01

    The roles of non-coding RNAs in controlling clinical and biological heterogeneity in bladder cancer remain unclear. We used TCGA's published dataset (n = 405 tumors) as a discovery cohort and created a new validation cohort to define the miRNA expression patterns in the basal and luminal molecular subtypes of muscle-invasive bladder cancer (MIBC). We identified 63 miRNAs by PAM, which optimally identified basal and luminal tumors. The targets of the top luminal miRNAs were activators of EMT (ZEB1, ZEB2) and basal subtype transcription (IL-6, EGFR, STAT3), whereas the targets of the top basal miRNAs were involved in adipogenesis pathways and luminal breast cancer (ERBB2, ERBB3). We also identified a 15-miRNA signature that identified stromally infiltrated basal and luminal MIBCs corresponding to the “cluster IV/immune undifferentiated/claudin-low” and “cluster II/luminal immune” subtypes identified previously, which likely contain samples with higher infiltration rates. Using the 63-miRNA signature, we accurately assigned MIBCs to the basal and luminal subtypes and confirmed that patients with basal tumors had shorter overall survival. The results strongly suggest that miRNAs contribute to the control of the gene expression patterns observed in basal and luminal MIBCs and that they can be used as biomarkers and candidate therapeutic targets. PMID:27845906

  14. Specific micro-RNA expression patterns distinguish the basal and luminal subtypes of muscle-invasive bladder cancer.

    PubMed

    Ochoa, Andrea E; Choi, Woonyoung; Su, Xiaoping; Siefker-Radtke, Arlene; Czerniak, Bogdan; Dinney, Colin; McConkey, David J

    2016-12-06

    The roles of non-coding RNAs in controlling clinical and biological heterogeneity in bladder cancer remain unclear. We used TCGA's published dataset (n = 405 tumors) as a discovery cohort and created a new validation cohort to define the miRNA expression patterns in the basal and luminal molecular subtypes of muscle-invasive bladder cancer (MIBC). We identified 63 miRNAs by PAM, which optimally identified basal and luminal tumors. The targets of the top luminal miRNAs were activators of EMT (ZEB1, ZEB2) and basal subtype transcription (IL-6, EGFR, STAT3), whereas the targets of the top basal miRNAs were involved in adipogenesis pathways and luminal breast cancer (ERBB2, ERBB3). We also identified a 15-miRNA signature that identified stromally infiltrated basal and luminal MIBCs corresponding to the "cluster IV/immune undifferentiated/claudin-low" and "cluster II/luminal immune" subtypes identified previously, which likely contain samples with higher infiltration rates. Using the 63-miRNA signature, we accurately assigned MIBCs to the basal and luminal subtypes and confirmed that patients with basal tumors had shorter overall survival. The results strongly suggest that miRNAs contribute to the control of the gene expression patterns observed in basal and luminal MIBCs and that they can be used as biomarkers and candidate therapeutic targets.

  15. A visual circuit uses complementary mechanisms to support transient and sustained pupil constriction

    PubMed Central

    Keenan, William Thomas; Rupp, Alan C; Ross, Rachel A; Somasundaram, Preethi; Hiriyanna, Suja; Wu, Zhijian; Badea, Tudor C; Robinson, Phyllis R; Lowell, Bradford B; Hattar, Samer S

    2016-01-01

    Rapid and stable control of pupil size in response to light is critical for vision, but the neural coding mechanisms remain unclear. Here, we investigated the neural basis of pupil control by monitoring pupil size across time while manipulating each photoreceptor input or neurotransmitter output of intrinsically photosensitive retinal ganglion cells (ipRGCs), a critical relay in the control of pupil size. We show that transient and sustained pupil responses are mediated by distinct photoreceptors and neurotransmitters. Transient responses utilize input from rod photoreceptors and output by the classical neurotransmitter glutamate, but adapt within minutes. In contrast, sustained responses are dominated by non-conventional signaling mechanisms: melanopsin phototransduction in ipRGCs and output by the neuropeptide PACAP, which provide stable pupil maintenance across the day. These results highlight a temporal switch in the coding mechanisms of a neural circuit to support proper behavioral dynamics. DOI: http://dx.doi.org/10.7554/eLife.15392.001 PMID:27669145

  16. Blue and Red Light-Evoked Pupil Responses in Photophobic Subjects with TBI.

    PubMed

    Yuhas, Phillip T; Shorter, Patrick D; McDaniel, Catherine E; Earley, Michael J; Hartwick, Andrew T E

    2017-01-01

    Photophobia is a common symptom in individuals suffering from traumatic brain injury (TBI). Recent evidence has implicated blue light-sensitive intrinsically photosensitive retinal ganglion cells (ipRGCs) in contributing to the neural circuitry mediating photophobia in migraine sufferers. The goal of this work is to test the hypothesis that ipRGC function is altered in TBI patients with photophobia by assessing pupillary responses to blue and red light. Twenty-four case participants (mean age 43.3; 58% female), with mild TBI and self-reported photophobia, and 12 control participants (mean age 42.6; 58% female) were in this study. After 10 minutes of dark adaptation, blue (470 nm, 1 × 10 phots/s/cm) and red (625 nm, 7 × 10 phots/s/cm) flashing (0.1 Hz) light stimuli were delivered for 30 seconds to the dilated left eye while the right pupil was recorded. The amplitude of normalized pupil fluctuation (constriction and dilation) was quantified using Fourier fast transforms. In both case and control participants, the amplitude of pupil fluctuation was significantly less for the blue light stimuli as compared to the red light stimuli, consistent with a contribution of ipRGCs to these pupil responses. There was no significant difference in the mean pupil fluctuation amplitudes between the two participant groups, but case participants displayed greater variability in their pupil responses to the blue stimulus. Case and control participants showed robust ipRGC-mediated components in their pupil responses to blue light. The results did not support the hypothesis that ipRGCs are "hypersensitive" to light in TBI participants with photophobia. However, greater pupil response variability in the case subjects suggests that ipRGC function may be more heterogeneous in this group.

  17. Pupil-linked arousal is driven by decision uncertainty and alters serial choice bias

    NASA Astrophysics Data System (ADS)

    Urai, Anne E.; Braun, Anke; Donner, Tobias H.

    2017-03-01

    While judging their sensory environments, decision-makers seem to use the uncertainty about their choices to guide adjustments of their subsequent behaviour. One possible source of these behavioural adjustments is arousal: decision uncertainty might drive the brain's arousal systems, which control global brain state and might thereby shape subsequent decision-making. Here, we measure pupil diameter, a proxy for central arousal state, in human observers performing a perceptual choice task of varying difficulty. Pupil dilation, after choice but before external feedback, reflects three hallmark signatures of decision uncertainty derived from a computational model. This increase in pupil-linked arousal boosts observers' tendency to alternate their choice on the subsequent trial. We conclude that decision uncertainty drives rapid changes in pupil-linked arousal state, which shape the serial correlation structure of ongoing choice behaviour.

  18. Infrared television pupillometer revised: Bright-pupil illumination and computer automation

    NASA Astrophysics Data System (ADS)

    Watanabe, Takeru; Ikeda, Manabu; Suzuki, Takahiro; Nakamura, Fukuzo

    1990-01-01

    A new-generation infrared-television pupillometer is described and related issues are discussed. In order to obtain a back-lit image of the pupil of the eye, and infrared-LED illuminator that outputs a squeezed beam and a recent CCD camera having enhanced sensitivity in the near-infrared region were incorporated. The infrared-ray exposure to the eye by this method was determined to be quite low and hence a prolonged reconding could be made with safety. The bright-pupil image gives a definite pupil/iris boundary so that more accurate tracing of pupillary movement becomes feasible. In particular, intrinsic responses of the pupil in dim and dark adapted conditions can be measured stably and precisely. Simple, carefully designed, and inexpensive hardware implementation using a microcomputer, as well as a necessary control program for autonomous data acquisition, is presented in detail.

  19. Pupil-linked arousal is driven by decision uncertainty and alters serial choice bias

    PubMed Central

    Urai, Anne E.; Braun, Anke; Donner, Tobias H.

    2017-01-01

    While judging their sensory environments, decision-makers seem to use the uncertainty about their choices to guide adjustments of their subsequent behaviour. One possible source of these behavioural adjustments is arousal: decision uncertainty might drive the brain's arousal systems, which control global brain state and might thereby shape subsequent decision-making. Here, we measure pupil diameter, a proxy for central arousal state, in human observers performing a perceptual choice task of varying difficulty. Pupil dilation, after choice but before external feedback, reflects three hallmark signatures of decision uncertainty derived from a computational model. This increase in pupil-linked arousal boosts observers' tendency to alternate their choice on the subsequent trial. We conclude that decision uncertainty drives rapid changes in pupil-linked arousal state, which shape the serial correlation structure of ongoing choice behaviour. PMID:28256514

  20. Pupil-linked arousal is driven by decision uncertainty and alters serial choice bias.

    PubMed

    Urai, Anne E; Braun, Anke; Donner, Tobias H

    2017-03-03

    While judging their sensory environments, decision-makers seem to use the uncertainty about their choices to guide adjustments of their subsequent behaviour. One possible source of these behavioural adjustments is arousal: decision uncertainty might drive the brain's arousal systems, which control global brain state and might thereby shape subsequent decision-making. Here, we measure pupil diameter, a proxy for central arousal state, in human observers performing a perceptual choice task of varying difficulty. Pupil dilation, after choice but before external feedback, reflects three hallmark signatures of decision uncertainty derived from a computational model. This increase in pupil-linked arousal boosts observers' tendency to alternate their choice on the subsequent trial. We conclude that decision uncertainty drives rapid changes in pupil-linked arousal state, which shape the serial correlation structure of ongoing choice behaviour.

  1. Secondary school pupils' perceptions of physics

    NASA Astrophysics Data System (ADS)

    Barmby, Patrick; Defty, Neil

    2006-11-01

    This paper describes the analysis of data collected by Durham University’s YELLIS project, over the period of 1999 to 2004. Included in this data was the degree to which pupils in England at the end of their secondary education ‘liked’ or ‘disliked’ different subjects, and their expected examination grades in these subjects. The authors’ study focused on the perceptions of pupils in the science subjects of biology, chemistry and physics. Using the available data, they were able to analyse the perceptions of a large number of pupils (e.g. 9827 pupils in 2004) who took examinations in the separate sciences. The study found that physics was perceived as the least popular science, particularly by female pupils. We also found that the expected grade in a particular science subject correlated quite strongly (Spearman’s rho of around 0.5) with the liking of that subject. These expected grades were found to be the lowest in physics, again particularly for female pupils. The authors therefore concluded that in order to redress the gender imbalance in physics, they need to tackle this problem that physics is perceived as difficult by female pupils.

  2. Pupil size and corneal laser surgery.

    PubMed

    Salz, James J; Trattler, William

    2006-08-01

    The role of scotopic pupil size as a factor in predicting night vision complaints is controversial. This review summarizes reports in the literature, some that have found and some that have failed to find a correlation with scotopic pupil size and night vision complaints. Pupil-measuring devices are discussed along with informed consent issues and reports showing that wavefront aberrations increase with increasing pupil size. A new objective measuring device (Larson) showed a correlation with postoperative starbursts and pupil size and a decrease in starbursts with wavefront-guided treatments compared with conventional excimer laser treatments. Cortical adaptation allows many patients to adapt to their new night vision. Treatment options for those who remain symptomatic include drops to reduce pupil size and wavefront-guided retreatments. Reports in the literature are conflicting, and refractive surgeons would be wise to inform their patients that large scotopic pupil size is a potential risk factor for night vision complaints. By doing this they will follow the recommendations in recent patient information brochures of both VISX (Santa Clara, California) and Alcon (Orlando, Florida) and on the United States Food and Drug Administration web site.

  3. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment

    PubMed Central

    Zekveld, Adriana A.; Naylor, Graham; Ohlenforst, Barbara; Jansma, Elise P.; Lorens, Artur; Lunner, Thomas; Kramer, Sophia E.

    2016-01-01

    Context Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown. Objectives To 1) review the evidence for the pupil light reflex being a sensitive method to evaluate parasympathetic dysfunction, 2) review the evidence relating hearing impairment and parasympathetic activity and 3) seek evidence of possible connections between hearing impairment and the pupil light reflex. Methods Literature searches were performed in five electronic databases. All selected articles were categorized into three sections: pupil light reflex and parasympathetic dysfunction, hearing impairment and parasympathetic activity, pupil light reflex and hearing impairment. Results Thirty-eight articles were included in this review. Among them, 36 articles addressed the pupil light reflex and parasympathetic dysfunction. We summarized the information in these data according to different types of parasympathetic-related diseases. Most of the studies showed a difference on at least one pupil light reflex parameter between patients and healthy controls. Two articles discussed the relationship between hearing impairment and parasympathetic activity. Both studies reported a reduced parasympathetic activity in the hearing impaired groups. The searches identified no results for pupil light reflex and hearing impairment. Discussion and Conclusions As the first systematic review of the evidence, our findings suggest that the pupil light reflex is a sensitive tool to assess the presence of parasympathetic dysfunction. Maximum constriction velocity and relative constriction amplitude appear to be the most sensitive parameters. There are only two studies investigating the

  4. Two-zone pupil filters

    NASA Astrophysics Data System (ADS)

    Sheppard, Colin J. R.; Campos, Juan; Escalera, Juan C.; Ledesma, Silvia

    2008-03-01

    The performance of pupil filters consisting of two zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified and optimized. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters. The first of these minimizes the relative power in the outer rings for a given axial resolution, the second maximizes the Strehl ratio for a given transverse resolution, and the third minimizes the relative power in the outer rings for a given transverse resolution. Complex filters can give an axially shifted maximum in intensity: the performance parameters calculated relative to the true focus are investigated for some different classes of filter, but filters with phase change not equal to π are found to give inferior performance to the real value filters.

  5. Influence of high ambient illuminance and display luminance on readability and subjective preference

    NASA Astrophysics Data System (ADS)

    De Moor, Katrien; Andrén, Börje; Guo, Yi; Brunnström, Kjell; Wang, Kun; Drott, Anton; Hermann, David S.

    2015-03-01

    Many devices, such as tablets, smartphones, notebooks, fixed and portable navigation systems are used on a (nearly) daily basis, both in in- and outdoor environments. It is often argued that contextual factors, such as the ambient illuminance in relation to characteristics of the display (e.g., surface treatment, screen reflectance, display luminance …) may have a strong influence on the use of such devices and corresponding user experiences. However, the current understanding of these influence factors is still rather limited. In this work, we therefore focus in particular on the impact of lighting and display luminance on readability, visual performance, subjective experience and preference. A controlled lab study (N=18) with a within-subjects design was performed to evaluate two car displays (one glossy and one matte display) in conditions that simulate bright outdoor lighting conditions. Four ambient luminance levels and three display luminance settings were combined into 7 experimental conditions. More concretely, we investigated for each display: (1) whether and how readability and visual performance varied with the different combinations of ambient luminance and display luminance and (2) whether and how they influenced the subjective experience (through self-reported valence, annoyance, visual fatigue) and preference. The results indicate a limited, yet negative influence of increased ambient luminance and reduced contrast on visual performance and readability for both displays. Similarly, we found that the self-reported valence decreases and annoyance and visual fatigue increase as the contrast ratio decreases and ambient luminance increases. Overall, the impact is clearer for the matte display than for the glossy display.

  6. Dependency of reaction times to motion onset on luminance and chromatic contrast.

    PubMed

    Burr, D C; Corsale, B

    2001-04-01

    We measured reaction times for detecting the onset of motion of sinusoidal gratings of 1 c/deg, modulated in either luminance or chromatic contrast, caused to move abruptly at speeds ranging from 0.25 to 10 deg/s (0.25-10 Hz). At any given luminance or chromatic contrast, RTs varied linearly with temporal periodicity (r2 congruent with 0.97), yielding a Weber fraction of period. The value of the Weber fraction varied inversely with contrast, differently for luminance and chromatic contrast. The results were well simulated with a simple model that accumulated change in contrast over time until a critical threshold had been reached. Two crucial aspects of the model are a second-stage temporal integration mechanism, capable of accumulating information for periods of up to 2 s, and contrast gain control, different for luminance than for chromatic stimuli. The contrast response for luminance shows very low semi-saturating contrasts and high gain, similar to LGN M-cells and cells in MT; that for colour shows high semi-saturating contrasts and low gain, similar to LGN P-cells. The results suggest that motion onset for luminance and chromatic gratings are detected by different mechanisms, probably by the magno- and parvo-cellular systems.

  7. New Techniques of Difference: On Data as School Pupils

    ERIC Educational Resources Information Center

    Thoutenhoofd, Ernst D.

    2017-01-01

    Pupils--the learners of both educational thought and of educational practice--exist ever more as data, as do the strictures and goals through which these pupils are pedagogically managed. I elaborate this thought by way of a single example: a particular kind of pupils whose number is reportedly on the increase, namely pupils diagnosed with…

  8. Teachers' and Pupils' Perceptions of Creativity across Different Key Stages

    ERIC Educational Resources Information Center

    Turner, Sarah

    2013-01-01

    The new Secondary Curriculum (implemented in 2008) saw greater emphasis on creativity within the National Curriculum for England. Since this term has been boldly stated, how have teachers and pupils responded to it in the classroom? This study draws on responses from a range of pupils in different Key Stages (2 (pupils aged 7-11), 3 (pupils aged…

  9. Teachers' Personal Constructs and their Pupils' Self-images.

    ERIC Educational Resources Information Center

    Blease, Derek

    1986-01-01

    Investigates the relationship between 12 teachers' perceptions of 24 secondary pupils and the pupils' own views of themselves as learners. While students' images are not solely dependent upon teacher interaction, results show a significant and positive relationship between teachers' perceptions of the pupils and the pupils' views of themselves.…

  10. Permanent alterations in muscarinic receptors and pupil size produced by chronic atropinization in kittens

    SciTech Connect

    Smith, E.L.; Redburn, D.A.; Harwerth, R.S.; Maguire, G.W.

    1984-02-01

    Chronic mydriasis was induced in six kittens (four monocular, two binocular) and two adult cats (both monocular) by the daily topical application of atropine. Both the kittens and the adult cats were atropinized for a 13-week period with the treatment regimen beginning at the time of eye opening for the kittens. Pupil size measurements, obtained 1 year after the atropinization were discontinued, revealed that, although the pupils of the adult cats were normal, the pupils of the kittens' treated eyes were consistently smaller than pupils in control eyes. The status of the muscarinic receptors in the kittens' irides was investigated using /sup 3/H-QNB binding assays. In comparison with iris muscle homogenates from the control eyes, those from the treated eyes demonstrated an eightfold increase in the number of receptor binding sites. The results indicate that pupil size can be altered permanently by chronic mydriasis initiated early in the life of a kitten and that the permanent change in pupil size may result, in part, from a type of permanent supersensitivity response in the muscle following chronic blockade of muscarinic transmission by atropine.

  11. Symmetry properties with pupil phase-filters.

    PubMed

    Ledesma, Silvia; Campos, J; Escalera, J; Yzuel, M

    2004-05-31

    Pupil filters can modify the three dimensional response of an optical system. In this paper, we study different pupil symmetries that produce a predictable image behavior. We show that different pupil-filters that satisfy certain symmetry conditions can produce axial responses which are either identical or mirror reflected. We also establish the differences in the symmetry properties between amplitude-only filters and phase-only filters. In particular, we are interested in phase filters that produce transverse superresolution with axial superresolution or high depth of focus.

  12. CO excitation in four IR luminous galaxies

    NASA Astrophysics Data System (ADS)

    Radford, Simon J. E.; Solomon, P. M.; Downes, Dennis

    1990-07-01

    The correlation between the CO and far infrared luminosities of spiral galaxies is well established. The luminosity ration, LFIR/L sub CO in IR luminous active galaxies is, however, systematically five to ten times higher than in ordinary spirals and molecular clouds in our Galaxy. Furthermore, the masses of molecular hydrogen in luminous galaxies are large, M (H2) approx. equals 1010 solar magnitude, which indicates the observed luminosity ratios are due to an excess of infrared output, rather than a deficiency of molecular gas. These large amounts of molecular gas may fuel luminous galaxies through either star formation or nuclear activity. This interpretation rests on applying the M (H2)/LCO ratio calibrated in our Galaxy to galaxies with strikingly different luminosity ratios. But are the physical conditions of the molecular gas different in galaxies with different luminosity ratios. And, if so, does the proportionality between CO and H2 also vary among galaxies. To investigate these questions researchers observed CO (2 to 1) and (1 to 0) emission from four luminous galaxies with the Institute for Radio Astronomy in the Millimeter range (IRAM) 30 m telescope. Researchers conclude that most of the CO emission from these Arp 193, Arp 220, and Mrk 231 arises in regions with moderate ambient densities similar to the clouds in the Milky Way molecular ring. The emission is neither from dense hot cloud cores nor from the cold low density gas characteristic of the envelopes of dark clouds.

  13. CO excitation in four IR luminous galaxies

    NASA Technical Reports Server (NTRS)

    Radford, Simon J. E.; Solomon, P. M.; Downes, Dennis

    1990-01-01

    The correlation between the CO and far infrared luminosities of spiral galaxies is well established. The luminosity ration, L sub FIR/L sub CO in IR luminous active galaxies is, however, systematically five to ten times higher than in ordinary spirals and molecular clouds in our Galaxy. Furthermore, the masses of molecular hydrogen in luminous galaxies are large, M (H2) approx. equals 10(exp 10) solar magnitude, which indicates the observed luminosity ratios are due to an excess of infrared output, rather than a deficiency of molecular gas. These large amounts of molecular gas may fuel luminous galaxies through either star formation or nuclear activity. This interpretation rests on applying the M (H2)/L sub CO ratio calibrated in our Galaxy to galaxies with strikingly different luminosity ratios. But are the physical conditions of the molecular gas different in galaxies with different luminosity ratios. And, if so, does the proportionality between CO and H2 also vary among galaxies. To investigate these questions researchers observed CO (2 to 1) and (1 to 0) emission from four luminous galaxies with the Institute for Radio Astronomy in the Millimeter range (IRAM) 30 m telescope. Researchers conclude that most of the CO emission from these Arp 193, Arp 220, and Mrk 231 arises in regions with moderate ambient densities similar to the clouds in the Milky Way molecular ring. The emission is neither from dense hot cloud cores nor from the cold low density gas characteristic of the envelopes of dark clouds.

  14. THE EFFECTS OF LIGHT ON LUMINOUS BACTERIA

    PubMed Central

    Harvey, E. Newton

    1925-01-01

    A conservative statement would therefore be that luminous bacteria show no changes in luminescence as a result of illumination by 625 foot candles for 1.5 minutes when examined 1/200 of a second after exposure, and none as the result of illumination by 15,000 foot candles for 6 minutes when examined ⅙ of a second after exposure. PMID:19872170

  15. Luminous Binary Supersoft X-Ray Sources

    NASA Technical Reports Server (NTRS)

    DiStefano, Rosanne; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    This grant was for the study of Luminous Supersoft X-Ray Sources (SSSs). During the first year a number of projects were completed and new projects were started. The projects include: 1) Time variability of SSSs 2) SSSs in M31; 3) Binary evolution scenarios; and 4) Acquiring new data.

  16. [Tonic pupil, pupil Adie syndrome Adie Holmes: current reassessment of terminology -- a clinical case].

    PubMed

    Szabo, Bianca; Popescu, Livia Adriana; Rusu, Anca

    2012-01-01

    The benign syndrome of pupillotonia and absence of deep reflexes is not uncommon. It was clearly and accurately described by Adie (1932), although incompletely recognized many years, before. The pupillary abnormality was reported by ophthalmologists at the turn of the century (Saenger, 1902, Strasburger 1902), and the associated deep reflex change was described by Markus (1906), Roemheld (1921) and Parkes Weber (1923). Holmes (1932) was fully aware of the association of "partial iridoplegia" with diminished reflexes. Tonic pupils react poorly to light but constrict during viewing of a near stimulus. Adie's name is typically used in association with tonic pupils, but a review of Adie's articles reveals that he described the syndrome of tonic pupils and absent reflexes and not the pupillary abnormality per se. Therefore, it would be more appropriate to refer to a tonic pupil as simply a 'tonic pupil" and leave Adie's name for the syndrome. We report a typical case of tonic pupil.

  17. Evolution of luminous IRAS galaxies: Radio imaging

    NASA Technical Reports Server (NTRS)

    Neff, S. G.; Hutchings, J. B.

    1993-01-01

    In a recent study of IRAS galaxies' optical morphologies, we found that luminous IR sources lie in the IR color-luminosity plane in groups which separate out by optical spectroscopic type and also by degree of tidal disturbance. We found that the most luminous steep-IR-spectrum sources are generally galaxies in the initial stages of a major tidal interaction. Galaxies with active nuclei were generally found to have flatter IR spectra, to cover a range of IR luminosity, and to be in the later stages of a tidal interaction. We proposed a sequence of events by which luminous IR sources evolve: they start as interacting or merging galaxies, some develop active nuclei, and most undergo extensive star-formation in their central regions. Another way to study these objects and their individual evolution is to study their radio morphologies. Radio emission may arise at a detectable level from supernovae in star-forming regions and/or the appearance of an active nucleus can be accompanied by a nuclear radio source (which may develop extended structure). Therefore, the compact radio structure may trace the evolution of the inner regions of IRAS-luminous sources. If the radio sources are triggered by the interactions, we would expect to find the radio morphology related to the optical 'interactivity' of the systems. Here, we explore using the radio emission of IRAS galaxies as a possible tracer of galaxy evolution. We present and discuss observations of the compact radio morphology of 111 luminous IRAS-selected active galaxies covering a wide range of IR and optical properties.

  18. Teachers' and Pupils' Behavior in Large and Small Classes: A Systematic Observation Study of Pupils Aged 10 and 11 Years

    ERIC Educational Resources Information Center

    Blatchford, Peter; Bassett, Paul; Brown, Penelope

    2005-01-01

    The authors examined class size effects on teacher-pupil interactions, pupil engagement, and pupil-pupil interaction. They extended previous research by recognizing the hierarchical nature of observation data and the possible influence of other variables. The study used a time sampling method involving 257 children (aged 10-11 years) in 16 small…

  19. Problematising Pupil Voice Using Visual Methods: Findings from a Study of Engaged and Disaffected Pupils in an Urban Secondary School

    ERIC Educational Resources Information Center

    Cremin, Hilary; Mason, Carolynne; Busher, Hugh

    2011-01-01

    This article explores how pupils and teachers in an 11-16 mixed secondary school in an area of urban disadvantage in the UK experience pupil voice. It used visual methods to unpick some of the ways in which official and unofficial discourses of pupil voice, engagement, discipline and inclusion were played out in this school. A typology of pupils,…

  20. Relationships among Teacher and Pupil Self-Concept and Pupil Reading Achievement at the First Grade Level.

    ERIC Educational Resources Information Center

    Brantley, Verna Lee

    Relationships among teacher and pupil self-concepts and pupil reading achievement were investigated in a sample of 239 first-grade pupils and the 17 teachers assigned to them. Results from pretesting and posttesting indicated that a positive relationship existed among changes in certain elements of pupil self-concept (self-acceptance, social…

  1. White spots in the pupil (image)

    MedlinePlus

    ... occasion, the pupil of the eye may appear white. This is never a normal condition and requires ... an ophthalmologist. The causes of a cloudy or white cornea are different than those of a white ...

  2. Environmental Education and Hearing-Impaired Pupils.

    ERIC Educational Resources Information Center

    Lock, Roger

    1998-01-01

    Reports on a way in which student teachers are given the opportunity to work with partially hearing pupils in the context of environmental education outside the science laboratory. Focuses on student investigation of moss on trees. (DDR)

  3. Pupil responses derived from outer and inner retinal photoreception are normal in patients with hereditary optic neuropathy.

    PubMed

    Kawasaki, Aki; Collomb, Sylvie; Léon, Lorette; Münch, Mirjam

    2014-03-01

    We compared the pupil responses originating from outer versus inner retinal photoreception between patients with isolated hereditary optic neuropathy (HON, n = 8) and healthy controls (n = 8). Three different testing protocols were used. For the first two protocols, a response function of the maximal pupil contraction versus stimulus light intensity was generated and the intensity at which half of the maximal pupil contraction, the half-max intensity, was determined. For the third protocol, the pupil size after light offset, the re-dilation rate and re-dilation amplitude were calculated to assess the post-light stimulus response. Patients with HON had bilateral, symmetric optic atrophy and significant reduction of visual acuity and visual field compared to controls. There were no significant mean differences in the response curve and pupil response parameters that reflect mainly rod, cone or melanopsin activity between patients and controls. In patients, there was a significant correlation between the half-max intensity of the red light sequence and visual field loss. In conclusion, pupil responses derived from outer or inner retinal photoreception in HON patients having mild-to moderate visual dysfunction are not quantitatively different from age-matched controls. However, an association between the degree of visual field loss and the half-max intensity of the cone response suggests that more advanced stages of disease may lead to impaired pupil light reflexes.

  4. Luminous efficiency estimates of meteors -I. Uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Subasinghe, Dilini; Campbell-Brown, Margaret; Stokan, Edward

    2017-09-01

    The luminous efficiency of meteors is poorly known, but critical for determining the meteoroid mass. We present an uncertainty analysis of the luminous efficiency as determined by the classical ablation equations, and suggest a possible method for determining the luminous efficiency of real meteor events. We find that a two-term exponential fit to simulated lag data is able to reproduce simulated luminous efficiencies reasonably well.

  5. Pupil Size Tracks Attentional Performance In Attention-Deficit/Hyperactivity Disorder.

    PubMed

    Wainstein, G; Rojas-Líbano, D; Crossley, N A; Carrasco, X; Aboitiz, F; Ossandón, T

    2017-08-15

    Attention-deficit/hyperactivity disorder (ADHD) diagnosis is based on reported symptoms, which carries the potential risk of over- or under-diagnosis. A biological marker that helps to objectively define the disorder, providing information about its pathophysiology, is needed. A promising marker of cognitive states in humans is pupil size, which reflects the activity of an 'arousal' network, related to the norepinephrine system. We monitored pupil size from ADHD and control subjects, during a visuo-spatial working memory task. A sub group of ADHD children performed the task twice, with and without methylphenidate, a norepinephrine-dopamine reuptake inhibitor. Off-medication patients showed a decreased pupil diameter during the task. This difference was no longer present when patients were on-medication. Pupil size correlated with the subjects' performance and reaction time variability, two vastly studied indicators of attention. Furthermore, this effect was modulated by medication. Through pupil size, we provide evidence of an involvement of the noradrenergic system during an attentional task. Our results suggest that pupil size could serve as a biomarker in ADHD.

  6. Relating Pupil Dilation and Metacognitive Confidence during Auditory Decision-Making.

    PubMed

    Lempert, Karolina M; Chen, Yu Lin; Fleming, Stephen M

    2015-01-01

    The sources of evidence contributing to metacognitive assessments of confidence in decision-making remain unclear. Previous research has shown that pupil dilation is related to the signaling of uncertainty in a variety of decision tasks. Here we ask whether pupil dilation is also related to metacognitive estimates of confidence. Specifically, we measure the relationship between pupil dilation and confidence during an auditory decision task using a general linear model approach to take into account delays in the pupillary response. We found that pupil dilation responses track the inverse of confidence before but not after a decision is made, even when controlling for stimulus difficulty. In support of an additional post-decisional contribution to the accuracy of confidence judgments, we found that participants with better metacognitive ability - that is, more accurate appraisal of their own decisions - showed a tighter relationship between post-decisional pupil dilation and confidence. Together our findings show that a physiological index of uncertainty, pupil dilation, predicts both confidence and metacognitive accuracy for auditory decisions.

  7. Pupil Response to Threat in Trauma-Exposed Individuals With or Without PTSD.

    PubMed

    Cascardi, Michele; Armstrong, Davine; Chung, Leeyup; Paré, Denis

    2015-08-01

    An infrequently studied and potentially promising physiological marker for posttraumatic stress disorder (PTSD) is pupil response. This study tested the hypothesis that pupil responses to threat would be significantly larger in trauma-exposed individuals with PTSD compared to those without PTSD. Eye-tracking technology was used to evaluate pupil response to threatening and neutral images. Recruited for participation were 40 trauma-exposed individuals; 40.0% (n = 16) met diagnostic criteria for PTSD. Individuals with PTSD showed significantly more pupil dilation to threat-relevant stimuli compared to the neutral elements (Cohen's d = 0.76), and to trauma-exposed controls (Cohen's d = 0.75). Pupil dilation significantly accounted for 12% of variability in PTSD after time elapsed since most recent trauma, cumulative violence exposure, and trait anxiety were statistically adjusted. The final logistic regression model was associated with 85% of variability in PTSD status and correctly classified 93.8% of individuals with PTSD and 95.8% of those without. Pupil reactivity showed promise as a physiological marker for PTSD.

  8. Relating Pupil Dilation and Metacognitive Confidence during Auditory Decision-Making

    PubMed Central

    Lempert, Karolina M.; Chen, Yu Lin; Fleming, Stephen M.

    2015-01-01

    The sources of evidence contributing to metacognitive assessments of confidence in decision-making remain unclear. Previous research has shown that pupil dilation is related to the signaling of uncertainty in a variety of decision tasks. Here we ask whether pupil dilation is also related to metacognitive estimates of confidence. Specifically, we measure the relationship between pupil dilation and confidence during an auditory decision task using a general linear model approach to take into account delays in the pupillary response. We found that pupil dilation responses track the inverse of confidence before but not after a decision is made, even when controlling for stimulus difficulty. In support of an additional post-decisional contribution to the accuracy of confidence judgments, we found that participants with better metacognitive ability – that is, more accurate appraisal of their own decisions – showed a tighter relationship between post-decisional pupil dilation and confidence. Together our findings show that a physiological index of uncertainty, pupil dilation, predicts both confidence and metacognitive accuracy for auditory decisions. PMID:25950839

  9. Pupil diameter as predictor of cognitive load: A novel tool for geoscience education research

    NASA Astrophysics Data System (ADS)

    Mitra, R.; McNeal, K.

    2015-12-01

    Pupils can truly serve as windows to the mind. Since the early part of the last decade, pupillometry, the study of pupils in response to cognitive tasks, have gained traction in psychophysiological studies. Muscles of the iris work in tandem with the autonomic nervous system in response to light condition to either dilate or contract the pupil, usually between 2 to 7 mm. Along with this response to light conditions, the pupils also contract or dilate in response to emotional or mental response. Therefore, for a cognitive task, if the ambient brightness is controlled, pupil dilation reflects the cognitive load associated with the task. Simple tasks such as counting, memorizing, multiplying and visual searching have been found to have pupillometry profiles reflective of the cognitive load involved with such tasks. In this study, we investigate whether pupil diameter can be used for education research where tasks can be more complex. In particular, we look at two specific types of tasks common in geoscience and several other STEM fields: graph reading and spatial problem solving.

  10. Pupil size changes during recognition memory.

    PubMed

    Otero, Samantha C; Weekes, Brendan S; Hutton, Samuel B

    2011-10-01

    Pupils dilate to a greater extent when participants view old compared to new items during recognition memory tests. We report three experiments investigating the cognitive processes associated with this pupil old/new effect. Using a remember/know procedure, we found that the effect occurred for old items that were both remembered and known at recognition, although it was attenuated for known compared to remembered items. In Experiment 2, the pupil old/new effect was observed when items were presented acoustically, suggesting the effect does not depend on low-level visual processes. The pupil old/new effect was also greater for items encoded under deep compared to shallow orienting instructions, suggesting it may reflect the strength of the underlying memory trace. Finally, the pupil old/new effect was also found when participants falsely recognized items as being old. We propose that pupils respond to a strength-of-memory signal and suggest that pupillometry provides a useful technique for exploring the underlying mechanisms of recognition memory.

  11. Robust reflective pupil slicing technology

    NASA Astrophysics Data System (ADS)

    Meade, Jeffrey T.; Behr, Bradford B.; Cenko, Andrew T.; Hajian, Arsen R.

    2014-07-01

    Tornado Spectral Systems (TSS) has developed the High Throughput Virtual Slit (HTVSTM), robust all-reflective pupil slicing technology capable of replacing the slit in research-, commercial- and MIL-SPEC-grade spectrometer systems. In the simplest configuration, the HTVS allows optical designers to remove the lossy slit from pointsource spectrometers and widen the input slit of long-slit spectrometers, greatly increasing throughput without loss of spectral resolution or cross-dispersion information. The HTVS works by transferring etendue between image plane axes but operating in the pupil domain rather than at a focal plane. While useful for other technologies, this is especially relevant for spectroscopic applications by performing the same spectral narrowing as a slit without throwing away light on the slit aperture. HTVS can be implemented in all-reflective designs and only requires a small number of reflections for significant spectral resolution enhancement-HTVS systems can be efficiently implemented in most wavelength regions. The etendueshifting operation also provides smooth scaling with input spot/image size without requiring reconfiguration for different targets (such as different seeing disk diameters or different fiber core sizes). Like most slicing technologies, HTVS provides throughput increases of several times without resolution loss over equivalent slitbased designs. HTVS technology enables robust slit replacement in point-source spectrometer systems. By virtue of pupilspace operation this technology has several advantages over comparable image-space slicer technology, including the ability to adapt gracefully and linearly to changing source size and better vertical packing of the flux distribution. Additionally, this technology can be implemented with large slicing factors in both fast and slow beams and can easily scale from large, room-sized spectrometers through to small, telescope-mounted devices. Finally, this same technology is directly

  12. Adaptive optics with pupil tracking for high resolution retinal imaging.

    PubMed

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

    2012-02-01

    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics.

  13. Adaptive optics with pupil tracking for high resolution retinal imaging

    PubMed Central

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

    2012-01-01

    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics. PMID:22312577

  14. Compatibility of a Diffractive Pupil and Coronagraphic Imaging

    NASA Technical Reports Server (NTRS)

    Bendek, Eduardo; Belikov, Rusian; Pluzhnyk, Yevgeniy; Guyon, Olivier

    2013-01-01

    Detection and characterization of exo-earths require direct-imaging techniques that can deliver contrast ratios of 10(exp 10) at 100 milliarc-seconds or smaller angular separation. At the same time, astrometric data is required to measure planet masses and can help detect planets and constrain their orbital parameters. To minimize costs, a single space mission can be designed using a high efficiency coronograph to perform direct imaging and a diffractive pupil to calibrate wide-field distortions to enable high precision astrometric measurements. This paper reports the testing of a diffractive pupil on the high-contrast test bed at the NASA Ames Research Center to assess the compatibility of using a diffractive pupil with coronographic imaging systems. No diffractive contamination was found within our detectability limit of 2x10(exp -7) contrast outside a region of 12lambda/D and 2.5x10(exp -6) within a region spanning from 2 to 12lambda/D. Morphology of the image features suggests that no contamination exists even beyond the detectability limit specified or at smaller working angles. In the case that diffractive contamination is found beyond these stated levels, active wavefront control would be able to mitigate its intensity to 10(exp -7) or better contrast.

  15. Non-intrusive practitioner pupil detection for unmodified microscope oculars.

    PubMed

    Fuhl, Wolfgang; Santini, Thiago; Reichert, Carsten; Claus, Daniel; Herkommer, Alois; Bahmani, Hamed; Rifai, Katharina; Wahl, Siegfried; Kasneci, Enkelejda

    2016-12-01

    Modern microsurgery is a long and complex task requiring the surgeon to handle multiple microscope controls while performing the surgery. Eye tracking provides an additional means of interaction for the surgeon that could be used to alleviate this situation, diminishing surgeon fatigue and surgery time, thus decreasing risks of infection and human error. In this paper, we introduce a novel algorithm for pupil detection tailored for eye images acquired through an unmodified microscope ocular. The proposed approach, the Hough transform, and six state-of-the-art pupil detection algorithms were evaluated on over 4000 hand-labeled images acquired from a digital operating microscope with a non-intrusive monitoring system for the surgeon eyes integrated. Our results show that the proposed method reaches detection rates up to 71% for an error of ≈3% w.r.t the input image diagonal; none of the state-of-the-art pupil detection algorithms performed satisfactorily. The algorithm and hand-labeled data set can be downloaded at:: www.ti.uni-tuebingen.de/perception.

  16. Oxytocin enhances pupil dilation and sensitivity to 'hidden' emotional expressions.

    PubMed

    Leknes, Siri; Wessberg, Johan; Ellingsen, Dan-Mikael; Chelnokova, Olga; Olausson, Håkan; Laeng, Bruno

    2013-10-01

    Sensing others' emotions through subtle facial expressions is a highly important social skill. We investigated the effects of intranasal oxytocin treatment on the evaluation of explicit and 'hidden' emotional expressions and related the results to individual differences in sensitivity to others' subtle expressions of anger and happiness. Forty healthy volunteers participated in this double-blind, placebo-controlled crossover study, which shows that a single dose of intranasal oxytocin (40 IU) enhanced or 'sharpened' evaluative processing of others' positive and negative facial expression for both explicit and hidden emotional information. Our results point to mechanisms that could underpin oxytocin's prosocial effects in humans. Importantly, individual differences in baseline emotional sensitivity predicted oxytocin's effects on the ability to sense differences between faces with hidden emotional information. Participants with low emotional sensitivity showed greater oxytocin-induced improvement. These participants also showed larger task-related pupil dilation, suggesting that they also allocated the most attentional resources to the task. Overall, oxytocin treatment enhanced stimulus-induced pupil dilation, consistent with oxytocin enhancement of attention towards socially relevant stimuli. Since pupil dilation can be associated with increased attractiveness and approach behaviour, this effect could also represent a mechanism by which oxytocin increases human affiliation.

  17. Pupil aberrations in Offner spectrometers.

    PubMed

    González-Núñez, Héctor; Prieto-Blanco, Xesús; de la Fuente, Raúl

    2012-04-01

    The light path function (LPF) of an Offner spectrometer is presented. The evaluation of the LPF of this spectrometer enables its imaging properties to be studied for arbitrary object and image positions, while avoiding the more complicated analysis of intermediate images generated by the diffraction grating, which is often involved. A power series expansion of the LPF on the grating coordinates directly determines pupil aberrations of the generated spectrum and facilitates the search for configurations with small low-order aberrations. This analysis not only confirms the possibility of reducing low-order aberrations in Rowland-type mounts, namely astigmatism and coma, as predicted in previous studies, but also proves that all third-order terms in the series expansion of the aberration function can be canceled at the image of the design point and for the corresponding design wavelength, when the design point is located on a plane orthogonal to the optical axis. Furthermore, fourth-order terms are computed and shown to represent the most relevant contribution to image blurring. Third- and fourth-order aberrations are also evaluated for Rowland mounts with the design point located outside the aforementioned plane. The study described in this manuscript is not restricted to small angles of incidence, and, therefore, it goes beyond Seidel and Buchdahl aberrations.

  18. White LEDs with limit luminous efficacy

    SciTech Connect

    Lisitsyn, V. M.; Stepanov, S. A. Yangyang, Ju; Lukash, V. S.

    2016-01-15

    In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

  19. The Least Luminous Galaxies in the Universe

    NASA Astrophysics Data System (ADS)

    Willman, Beth

    2011-05-01

    In the past six years, more than two dozen dwarf galaxies have been discovered around the Milky Way and M31. Many of these discoveries are 100 times less luminous than any galaxy previously known, and a million times less luminous than the Milky Way itself. These discoveries have made astronomers question the very meaning of the word "galaxy", and hint that such ultra-faint dwarf galaxies may be the most numerous type of galaxy in the universe. This talk will highlight i. how we can see galaxies that are effectively invisible in images of the sky, ii. the brewing controversy over the definition of the term "galaxy", and iii. what ultra-faint galaxies can reveal about the distribution of dark matter in our Universe.

  20. Evolution of luminous IRAS sources - CCD imaging

    NASA Technical Reports Server (NTRS)

    Hutchings, J. B.; Neff, S. G.

    1991-01-01

    The paper presents optical imaging of a sample of 64 luminous IRAS galaxies which cover a wide range of IRAS spectra and luminosity and also include a range of optical types. The objects are almost all in current or recent tidal interaction. The connections between the strength and age of the interaction, the IR spectrum and luminosity, and the optical colors, and other properties of the galaxies are discussed. The principal result is that the powerful IR sources with steep IR spectra are stronger and dynamically younger interacting systems, while the flat IR spectrum objects are older. Star formation, dust obscuration, and the timescales for nuclear activity compared with IR and tidal events are discussed, and a self-consistent evolution scenario connecting the luminous IR sources is described.

  1. Evolution of luminous IRAS sources - Radio imaging

    NASA Technical Reports Server (NTRS)

    Neff, S. G.; Hutchings, J. B.

    1992-01-01

    Observations of the compact radio morphology of 111 luminous IRAS-selected active galaxies covering a wide range of IR and optical properties are presented and discussed. Of these sources, 72 are observed for the first time with the VLA A configuration. The circumnuclear radio sources are generally small and weak, with 15 nondetections to a limit of about 0.4 mJy. Comparison with the IR and optical properties of the objects indicates that the radio sources turn on within 10 exp 8 yr of the tidal encounter that is presumed to generate the IR activity. However, the radio sources do not all appear at the same time. The radio observations are consistent with the evolution scenario for luminous IRAS galaxies suggested by Hutchings and Neff (1991).

  2. Achromatic Emission Velocity Measurements in Luminous Flows

    NASA Technical Reports Server (NTRS)

    Schneider, S. J.; Fulghum, S. F.; Rostler, P. S.

    1997-01-01

    A new velocity measurement instrument for luminous flows was developed by Science Research Laboratory for NASA. The SIEVE (Segmented Image Emission VElocimeter) instrument uses broadband light emitted by the flow for the velocity measurement. This differs from other velocimetry techniques in that it does not depend on laser illumination and/or light scattering from particles in the flow. The SIEVE is a passive, non-intrusive diagnostic. By moving and adjusting the imaging optics, the SIEVE can provide three-dimensional mapping of a flow field and determine turbulence scale size. A SIEVE instrument was demonstrated on an illuminated rotating disk to evaluate instrument response and noise and on an oxy-acetylene torch to measure flame velocities. The luminous flow in rocket combustors and plumes is an ideal subject for the SIEVE velocity measurement technique.

  3. Toward 10(exp 10) Contrast for Terrestrial Exoplanet Detection: Demonstration of Wavefront Correction in a Shaped Pupil Coronagraph

    NASA Technical Reports Server (NTRS)

    Belikov, Ruslan; Give'on, Amir; Trauger, John T.; Carr, Michael; Kasdin, Jeremy N.; Vanderbei, Robert J.; Shi, Fang; Balasubramanian, Kunjithapatham; Kuhnert, Andreas

    2006-01-01

    Experimental demonstration of wavefront control with shaped pupils. Contrast level is maintained across different wavelengths and 10% broadband light. Further improvements in contrast believed to have been possible with more time and parameter optimizations.

  4. Toward 10(exp 10) Contrast for Terrestrial Exoplanet Detection: Demonstration of Wavefront Correction in a Shaped Pupil Coronagraph

    NASA Technical Reports Server (NTRS)

    Belikov, Ruslan; Give'on, Amir; Trauger, John T.; Carr, Michael; Kasdin, Jeremy N.; Vanderbei, Robert J.; Shi, Fang; Balasubramanian, Kunjithapatham; Kuhnert, Andreas

    2006-01-01

    Experimental demonstration of wavefront control with shaped pupils. Contrast level is maintained across different wavelengths and 10% broadband light. Further improvements in contrast believed to have been possible with more time and parameter optimizations.

  5. Robust pupil center detection using a curvature algorithm

    NASA Technical Reports Server (NTRS)

    Zhu, D.; Moore, S. T.; Raphan, T.; Wall, C. C. (Principal Investigator)

    1999-01-01

    Determining the pupil center is fundamental for calculating eye orientation in video-based systems. Existing techniques are error prone and not robust because eyelids, eyelashes, corneal reflections or shadows in many instances occlude the pupil. We have developed a new algorithm which utilizes curvature characteristics of the pupil boundary to eliminate these artifacts. Pupil center is computed based solely on points related to the pupil boundary. For each boundary point, a curvature value is computed. Occlusion of the boundary induces characteristic peaks in the curvature function. Curvature values for normal pupil sizes were determined and a threshold was found which together with heuristics discriminated normal from abnormal curvature. Remaining boundary points were fit with an ellipse using a least squares error criterion. The center of the ellipse is an estimate of the pupil center. This technique is robust and accurately estimates pupil center with less than 40% of the pupil boundary points visible.

  6. Robust pupil center detection using a curvature algorithm

    NASA Technical Reports Server (NTRS)

    Zhu, D.; Moore, S. T.; Raphan, T.; Wall, C. C. (Principal Investigator)

    1999-01-01

    Determining the pupil center is fundamental for calculating eye orientation in video-based systems. Existing techniques are error prone and not robust because eyelids, eyelashes, corneal reflections or shadows in many instances occlude the pupil. We have developed a new algorithm which utilizes curvature characteristics of the pupil boundary to eliminate these artifacts. Pupil center is computed based solely on points related to the pupil boundary. For each boundary point, a curvature value is computed. Occlusion of the boundary induces characteristic peaks in the curvature function. Curvature values for normal pupil sizes were determined and a threshold was found which together with heuristics discriminated normal from abnormal curvature. Remaining boundary points were fit with an ellipse using a least squares error criterion. The center of the ellipse is an estimate of the pupil center. This technique is robust and accurately estimates pupil center with less than 40% of the pupil boundary points visible.

  7. Orbital masses of nearby luminous galaxies

    SciTech Connect

    Karachentsev, Igor D.; Kudrya, Yuri N. E-mail: yukudrya@gmail.com

    2014-09-01

    We use observational properties of galaxies accumulated in the Updated Nearby Galaxy Catalog to derive a dark matter mass of luminous galaxies via motions of their companions. The data on orbital-to-stellar mass ratio are presented for 15 luminous galaxies situated within 11 Mpc from us: the Milky Way, M31, M81, NGC 5128, IC342, NGC 253, NGC 4736, NGC 5236, NGC 6946, M101, NGC 4258, NGC 4594, NGC 3115, NGC 3627, and NGC 3368, as well as for a composite suite around other nearby galaxies of moderate and low luminosity. The typical ratio for these galaxies is M {sub orb}/M {sub *} = 31, corresponding to the mean local density of matter Ω {sub m} = 0.09, i.e., one-third of the global cosmic density. This quantity seems to be rather an upper limit of dark matter density, since the peripheric population of the suites may suffer from the presence of fictitious unbound members. We note that the Milky Way and M31 halos have lower dimensions and lower stellar masses than those of the other 13 nearby luminous galaxies. However, the dark-to-stellar mass ratio for both the Milky Way and M31 is typical for other neighboring luminous galaxies. The distortion in the Hubble flow, observed around the Local Group and five other neighboring groups, yields their total masses within the radius of a zero velocity surface, R {sub 0}; these masses are slightly lower than the orbital and virial values. This difference may be due to the effect of dark energy producing a kind of 'mass defect' within R {sub 0}.

  8. Intrinsic basal and luminal subtypes of muscle-invasive bladder cancer.

    PubMed

    Choi, Woonyoung; Czerniak, Bogdan; Ochoa, Andrea; Su, Xiaoping; Siefker-Radtke, Arlene; Dinney, Colin; McConkey, David J

    2014-07-01

    Whole-genome analyses have revealed that muscle-invasive bladder cancers (MIBCs) are heterogeneous and can be grouped into basal and luminal subtypes that are highly reminiscent of those found in breast cancer. Basal MIBCs are enriched with squamous and sarcomatoid features and are associated with advanced stage and metastatic disease at presentation. Like basal breast cancers, basal bladder tumours contain a claudin-low subtype that is enriched with biomarkers characteristic of epithelial-to-mesenchymal transition. The stem cell transcription factor ΔNp63α controls basal MIBC gene expression, just as it does in basal breast cancers. Luminal MIBCs are enriched with activating FGFR3 and ERBB3 mutations and ERBB2 amplifications, and their gene expression profiles are controlled by peroxisome proliferator activator receptor γ (PPARγ) and possibly also by oestrogen receptor activation. Luminal bladder cancers can be further subdivided into two subtypes, p53-like and luminal, which can be distinguished from one another by different levels of biomarkers that are characteristic of stromal infiltration, cell cycle progression, and proliferation. Importantly, basal bladder cancers are intrinsically aggressive, but are highly sensitive to cisplatin-based combination chemotherapy. Although the luminal subtypes are not as intrinsically aggressive as basal cancers, p53-like tumours are resistant to chemotherapy and might, therefore, represent a problem for treated patients.

  9. Paracrine Met signaling triggers epithelial–mesenchymal transition in mammary luminal progenitors, affecting their fate

    PubMed Central

    Di-Cicco, Amandine; Petit, Valérie; Chiche, Aurélie; Bresson, Laura; Romagnoli, Mathilde; Orian-Rousseau, Véronique; Vivanco, Maria dM; Medina, Daniel; Faraldo, Marisa M; Glukhova, Marina A; Deugnier, Marie-Ange

    2015-01-01

    HGF/Met signaling has recently been associated with basal-type breast cancers, which are thought to originate from progenitor cells residing in the luminal compartment of the mammary epithelium. We found that ICAM-1 efficiently marks mammary luminal progenitors comprising hormone receptor-positive and receptor-negative cells, presumably ductal and alveolar progenitors. Both cell populations strongly express Met, while HGF is produced by stromal and basal myoepithelial cells. We show that persistent HGF treatment stimulates the clonogenic activity of ICAM1-positive luminal progenitors, controlling their survival and proliferation, and leads to the expression of basal cell characteristics, including stem cell potential. This is accompanied by the induction of Snai1 and Snai2, two major transcription factors triggering epithelial–mesenchymal transition, the repression of the luminal-regulatory genes Elf5 and Hey1, and claudin down-regulation. Our data strongly indicate that paracrine Met signaling can control the function of luminal progenitors and modulate their fate during mammary development and tumorigenesis. DOI: http://dx.doi.org/10.7554/eLife.06104.001 PMID:26165517

  10. A Comparison of Written Compositions of Head-Start Pupils with Non-Head-Start Pupils.

    ERIC Educational Resources Information Center

    Houston, David Ree

    This study--a follow-up to one conducted by Giles in 1965-- compared the written compositions of fourth grade pupils who had been in Project Head Start in the summer of 1965 with those of comparable pupils not in the program to determine possible differences in their written language development. Seventy Negro students were divided by sex and…

  11. Body, Caring and Power in Teacher-Pupil Relationships: Encounters in Former Pupils' Memories

    ERIC Educational Resources Information Center

    Uitto, Minna; Syrjala, Leena

    2008-01-01

    This narrative inquiry aims to look at teacher-pupil relationships through teacher memories. When 49 university students of education were asked to write their memories of teachers, they told about their teachers in relation to pupils. The data were analysed thematically and, based on that, re-read through the concepts of body, caring and power in…

  12. Administration of Pupil Personnel Services. Pupil Personnel Services Recommended Practices and Procedures Manual.

    ERIC Educational Resources Information Center

    Irvin, Mari; Whiteside, David

    This volume, part of the Illinois State Board of Education's "Pupil Personnel Services Recommended Practices and Procedures Manual," deals with the administration of pupil personnel services (PPS). After a brief introduction, the following topics are covered: (1) major PPS concepts (including coordination of services, needs assessment,…

  13. Locked Out: Researching Destinations and Outcomes for Pupils Excluded from Special Schools and Pupil Referral Units

    ERIC Educational Resources Information Center

    Pirrie, Anne; Macleod, Gale

    2009-01-01

    This article explores the methodological challenges encountered during a study of destinations and outcomes for pupils permanently excluded from Pupil Referral Units (PRUs) and special schools in England. It outlines the manner in which the key phrases and assumptions embedded within the specification, terms such as routes and trajectories,…

  14. Pupil-segmentation-based adaptive optical microscopy with full-pupil illumination.

    PubMed

    Milkie, Daniel E; Betzig, Eric; Ji, Na

    2011-11-01

    Optical aberrations deteriorate the performance of microscopes. Adaptive optics can be used to improve imaging performance via wavefront shaping. Here, we demonstrate a pupil-segmentation based adaptive optical approach with full-pupil illumination. When implemented in a two-photon fluorescence microscope, it recovers diffraction-limited performance and improves imaging signal and resolution.

  15. A Study of Teacher-Pupil and Pupil-Pupil Interactional Differences Between Inquiry Centered Science and Traditional Science in Elementary Schools.

    ERIC Educational Resources Information Center

    Rains, Ohren Willis

    Reported is a study of teacher-pupil and pupil-pupil interactional differences between a traditional instruction method and an inquiry-centered learning method for 18 science classes at the fourth and fifth grade levels. Nine classes were assigned to the experimental group, and the remaining nine classes received a traditional program. Classroom…

  16. Sub-luminous γ-ray pulsars

    DOE PAGES

    Romani, R. W.; Kerr, M.; Craig, H. A.; ...

    2011-08-17

    Here, most pulsars observed by the Fermi Large Area Telescope have γ-ray luminosities scaling with spin-down powermore » $${\\dot{E}}$$ as $$L_\\gamma \\approx ({\\dot{E}}\\, \\times \\, 10^{33}\\,{\\rm erg \\,s^{-1}})^{1/2}$$. However, there exist one detection and several upper limits an order of magnitude or more fainter than this trend. We describe these "sub-luminous" γ-ray pulsars and discuss the case for this being an orientation effect. Of the 12 known young radio pulsars with $${\\dot{E}}>10^{34}\\, {\\rm erg\\,s^{-1}}$$ and d ≤ 2 kpc several are substantially sub-luminous. The limited available geometrical constraints favor aligned geometries for these pulsars, although no one case for alignment is compelling. In this scenario GeV emission detected from such sub-luminous pulsars can be due to a lower altitude, lower-power accelerator gap.« less

  17. Pulsations and outbursts of luminous blue variables

    SciTech Connect

    Cox, A.N.; Guzik, J.A.; Soukup, M.S.; Despain, K.M.

    1997-06-01

    We propose an outburst mechanism for the most luminous stars in our and other galaxies. These million solar luminosity stars, with masses (after earlier mass loss) of between 20 and maybe 70 solar masses, are pulsationally unstable for both radial and low-degree nonradial modes. Some of these modes are ``strange,`` meaning mostly that the pulsations are concentrated near the stellar surface and have very rapid growth rates in linear theory. The pulsation driving is by both the high iron line opacity (near 150,000 K) and the helium opacity (near 30,000 K) kappa effects. Periods range from 5 to 40 days. Depending on the composition, pulsations periodically produce luminosities above the Eddington limit for deep layers. The radiative luminosity creates an outward push that readily eases the very low gamma envelope to very large outburst radii. A key point is that a super-Eddington luminosity cannot be taken up by the sluggish convection rapidly enough to prevent an outward acceleration of much of the envelope. As the helium abundance in the envelope stellar material increases by ordinary wind mass loss and the luminous blue variable outbursts, the opacity in the deep pulsation driving layers decreases. This makes the current Eddington luminosity even higher so that pulsations can then no longer give radiative luminosities exceeding the limit. For the lower mass and luminosity luminous blue variables there is considerably less iron line opacity driving, and pulsations are almost all caused by the helium ionization kappa effect.

  18. Luminal breast cancer: from biology to treatment.

    PubMed

    Ignatiadis, Michail; Sotiriou, Christos

    2013-09-01

    Oestrogen receptor (ER)-positive--or luminal--tumours represent around two-thirds of all breast cancers. Luminal breast cancer is a highly heterogeneous disease comprising different histologies, gene-expression profiles and mutational patterns, with very varied clinical courses and responses to systemic treatment. Despite adjuvant endocrine therapy and chemotherapy treatment for patients at high risk of relapse, both early and late relapses still occur, a fact that highlights the unmet medical needs of these patients. Ongoing research aims to identify those patients who can be spared adjuvant chemotherapy and who will benefit from extended adjuvant hormone therapy. This research also aims to explore the role of adjuvant bisphosphonates, to interrogate new agents for targeting minimal residual disease, and to address endocrine resistance. Data from next-generation sequencing studies have given us new insight into the biology of luminal breast cancer and, together with advances in preclinical models and the availability of newer targeted agents, have led to the testing of rationally chosen combination treatments in clinical trials. However, a major challenge will be to make sense of the large amount of patient genomic data that is becoming increasingly available. This analysis will be critical to our understanding how intertumour and intratumour heterogeneity can influence treatment response and resistance.

  19. The pupil as an indicator of unconscious memory: Introducing the pupil priming effect.

    PubMed

    Gomes, Carlos Alexandre; Montaldi, Daniela; Mayes, Andrew

    2015-06-01

    We explored whether object behavioral priming and pupil changes occur in the absence of recognition memory. Experiment 1 found behavioral priming for unrecognized objects (Ms) regardless of whether they had been encoded perceptually or conceptually. Using the same perceptual encoding task, Experiment 2 showed greater pupil dilation for Ms than for correct rejections of unstudied objects (CRs) when reaction times were matched. In Experiment 3, there was relatively less pupil dilation for Ms than for similarly matched CRs when objects had been encoded conceptually. Mean/peak pupil dilation for CRs, but not Ms, increased in Experiment 3, in which novelty expectation was also reduced, and the pupillary time course for both Ms and CRs was distinct in the two experiments. These findings indicate that both behavioral and pupil memory occur for studied, but unrecognized stimuli, and suggest that encoding and novelty expectation modulate pupillary memory responses.

  20. Lateral pupil alignment tolerance in peripheral refractometry.

    PubMed

    Fedtke, Cathleen; Ehrmann, Klaus; Ho, Arthur; Holden, Brien A

    2011-05-01

    To investigate the tolerance to lateral pupil misalignment in peripheral refraction compared with central refraction. A Shin-Nippon NVision-K5001 open-view auto-refractor was used to measure central and peripheral refraction (30° temporal and 30° nasal visual field) of the right eyes of 10 emmetropic and 10 myopic participants. At each of the three fixation angles, five readings were recorded for each of the following alignment positions relative to pupil center: centrally aligned, 1 and 2 mm temporally aligned, and 1 and 2 mm nasally aligned. For central fixation, increasing dealignment from pupil center produced a quadratic decrease (r ≥ 0.98, p < 0.04) in the refractive power vectors M and J180 which, when interpolated, reached clinical significance (i.e., ≥ 0.25 diopter for M and ≥ 0.125 diopter for J180 and J45) for an alignment error of 0.79 mm or greater. M and J180 as measured in the 30° temporal and 30° nasal visual field led to a significant linear correlation (r ≥ 0.94, p < 0.02) as pupil dealignment gradually changed from temporal to nasal. As determined from regression analysis, a pupil alignment error of 0.20 mm or greater would introduce errors in M and J180 that are clinically significant. Tolerance to lateral pupil alignment error decreases strongly in the periphery compared with the greater tolerance in central refraction. Thus, precise alignment of the entrance pupil with the instrument axis is critical for accurate and reliable peripheral refraction.

  1. A self-made disposable iris retractor in small pupil phacoemulsification

    PubMed Central

    Li, Jie; Liu, Fei; Zhang, Wei-Wei; Zhang, Jun-Jun

    2014-01-01

    AIM To explore a simple and low-cost self-made disposable flexible iris retractor and study its clinical efficacy and safety in small pupil phacoemulsification. METHODS Polyproplyene suture and scalp acupuncture were used to make iris retractor. A prospective study were carried on 50 patients (50 eyes) with a maximally dilated pupil size of 2.5-4.0 mm which underwent phacoemulsification using this self-made iris retractor. Another 50 cases of phacoemulsification with normal pupil size sever as control group. The mean operation time, ultrasound time and ultrasonic power, volume of irrigation fluid were documented intraoperatively. The visual acuity, pupil size and complication were observed on 1d, 1wk, 1mo and 1y after operation. Corneal endothelial cell was measured at 1mo postoperatively. RESULT Pupils could be expanded to approximately 4.5-5.5 mm with our self-made iris retractor in operation. No serious postoperative complication was found. Most (88%) of the pupils returned round or oval shape, light reflex restored to varying degrees at the first day after surgery. Best corrected visual acuity stabilized in 37 eyes (74%) at one day, in 43 eyes (86%) at one week, in 44 eyes (88%) at one month and 46 eyes (92%) at one year. Compared with the control, more time was needed to complete the operation in the small pupil group. There was no significant difference of the mean ultrasound time, ultrasonic power, volume of irrigation fluid required and corneal endothelial cell loss in 1mo follow up between the two groups. CONCLUSION Our self-made disposable flexible iris retractor could be easy obtained preoperatively or intraoperatively. It performed both safety and efficacy in our clinical trials. This simple self-made device has shown economic and practical values, especially in primary care hospital of the less developed districts. PMID:24790872

  2. JWST science instrument pupil alignment measurements

    NASA Astrophysics Data System (ADS)

    Kubalak, Dave; Sullivan, Joe; Ohl, Ray; Antonille, Scott; Beaton, Alexander; Coulter, Phillip; Hartig, George; Kelly, Doug; Lee, David; Maszkiewicz, Michael; Schweiger, Paul; Telfer, Randal; Te Plate, Maurice; Wells, Martyn

    2016-09-01

    NASA's James Webb Space Telescope (JWST) is a 6.5m diameter, segmented, deployable telescope for cryogenic IR space astronomy ( 40K). The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI), including a guider. OSIM is a full field, cryogenic, optical simulator of the JWST OTE. It is the "Master Tool" for verifying the cryogenic alignment and optical performance of ISIM by providing simulated point source/star images to each of the four Science Instruments in ISIM. Included in OSIM is a Pupil Imaging Module (PIM) - a large format CCD used for measuring pupil alignment. Located at a virtual stop location within OSIM, the PIM records superimposed shadow images of pupil alignment reference (PAR) targets located in the OSIM and SI pupils. The OSIM Pupil Imaging Module was described by Brent Bos, et al, at SPIE in 2011 prior to ISIM testing. We have recently completed the third and final ISIM cryogenic performance verification test before ISIM was integrated with the OTE. In this paper, we describe PIM implementation, performance, and measurement results.

  3. The effects of luminance contribution from large fields to chromatic visual evoked potentials.

    PubMed

    Skiba, Rafal M; Duncan, Chad S; Crognale, Michael A

    2014-02-01

    Though useful from a clinical and practical standpoint uniform, large-field chromatic stimuli are likely to contain luminance contributions from retinal inhomogeneities. Such contribution can significantly influence psychophysical thresholds. However, the degree to which small luminance artifacts influence the chromatic VEP has been debated. In particular, claims have been made that band-pass tuning observed in chromatic VEPs result from luminance intrusion. However, there has been no direct evidence presented to support these claims. Recently, large-field isoluminant stimuli have been developed to control for intrusion from retinal inhomogeneities with particular regard to the influence of macular pigment. We report here the application of an improved version of these full-field stimuli to directly test the influence of luminance intrusion on the temporal tuning of the chromatic VEP. Our results show that band-pass tuning persists even when isoluminance is achieved throughout the extent of the stimulus. In addition, small amounts of luminance intrusion affect neither the shape of the temporal tuning function nor the major components of the VEP. These results support the conclusion that the chromatic VEP can depart substantially from threshold psychophysics with regard to temporal tuning and that obtaining a low-pass function is not requisite evidence of selective chromatic activation in the VEP. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Regulation of intestinal calcium absorption by luminal calcium content: role of intestinal alkaline phosphatase.

    PubMed

    Brun, Lucas R; Brance, María L; Lombarte, Mercedes; Lupo, Maela; Di Loreto, Verónica E; Rigalli, Alfredo

    2014-07-01

    Intestinal alkaline phosphatase is a brush border enzyme that is stimulated by calcium. Inhibition of intestinal alkaline phosphatase increases intestinal calcium absorption. We hypothesized that intestinal alkaline phosphatase acts as a minute-to-minute regulatory mechanism of calcium entry. The aim of this study was to evaluate the mechanism by which intestinal luminal calcium controls intestinal calcium absorption. We performed kinetic studies with purified intestinal alkaline phosphatase and everted duodenal sacs and showed that intestinal alkaline phosphatase modifies the luminal pH as a function of enzyme concentration and calcium luminal content. A decrease in pH occurred simultaneously with a decrease in calcium absorption. The inhibition of intestinal alkaline phosphatase by l-phenylalanine caused an increase in calcium absorption. This effect was also confirmed in calcium uptake experiments with isolated duodenal cells. Changes in luminal pH arising from intestinal alkaline phosphatase activity induced by luminal calcium concentration modulate intestinal calcium absorption. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Inverting pupil illumination from resist-based measurements

    NASA Astrophysics Data System (ADS)

    Perçin, Gokhan; Sezginer, Apo; Zach, Franz X.

    2006-03-01

    Computational models used in process proximity correction require accurate description of the pupil illumination function of the lithography projector. Traditional top-hat approximation for pupil illumination function is no longer sufficient to meet stringent CD control requirements of low-k1 applications. The pupil illumination profile can change across the exposure field, contributing to across-field linewidth variation. We present a measurement of the pupil illumination based on exposing pinhole patterns on a wafer at different dose and defocus settings, and processing SEM images of patterns printed in photoresist. The fundamental principle of the method is Abbe's formulation of image formation: the intensity-image formed in resist is an incoherent, linear superposition of images each one of which is formed by illuminating the photomask by a single plane-wave. A single plane-wave that is incident on the photomask maps to a single point in the Fourier-transform aperture of the illuminator. The pupil-fill of the illuminator is obtained from SEM images by a model-based method consisting of these steps: First, resist edges in the SEM images are detected by an edge detection algorithm based on Perona-Malik diffusion. Coordinates of the points on the resist edge are obtained with respect to a reference ruler. The image intensity at any resist edge is equal to the dose-to-clear. This provides an equation for the image intensity at each point on the edge of a pinhole image. Multiple values of dose and defocus, and multiple points on each resist edge provide a large system of equations. The result of the inversion for a 193nm 0.75 NA stepper with σ = 0.55/0.85 annular illumination at five exposure field locations is presented. The CD difference between the nominal top-hat illumination and the inverted illumination was up to 1.8 nm for 1:1 line and space features ranging from 100nm to 300nm. Variation of the illumination along the long-dimension of the slit of the

  6. Digital image comparison using feature extraction and luminance matching

    NASA Astrophysics Data System (ADS)

    Bachnak, Ray A.; Steidley, Carl W.; Funtanilla, Jeng

    2005-03-01

    This paper presents the results of comparing two digital images acquired using two different light sources. One of the sources is a 50-W metal halide lamp located in the compartment of an industrial borescope and the other is a 1 W LED placed at the tip of the insertion tube of the borescope. The two images are compared quantitatively and qualitatively using feature extraction and luminance matching approaches. Quantitative methods included the images' histograms, intensity profiles along a line segment, edges, and luminance measurement. Qualitative methods included image registration and linear conformal transformation with eight control points. This transformation is useful when shapes in the input image are unchanged, but the image is distorted by some combination of translation, rotation, and scaling. The gray-level histogram, edge detection, image profile and image registration do not offer conclusive results. The LED light source, however, produces good images for visual inspection by the operator. The paper presents the results and discusses the usefulness and shortcomings of various comparison methods.

  7. Post-illumination pupil response after blue light: Reliability of optimized melanopsin-based phototransduction assessment.

    PubMed

    van der Meijden, Wisse P; te Lindert, Bart H W; Bijlenga, Denise; Coppens, Joris E; Gómez-Herrero, Germán; Bruijel, Jessica; Kooij, J J Sandra; Cajochen, Christian; Bourgin, Patrice; Van Someren, Eus J W

    2015-10-01

    Melanopsin-containing retinal ganglion cells have recently been shown highly relevant to the non-image forming effects of light, through their direct projections on brain circuits that regulate alertness, mood and circadian rhythms. A quantitative assessment of functionality of the melanopsin-signaling pathway could be highly relevant in order to mechanistically understand individual differences in the effects of light on these regulatory systems. We here propose and validate a reliable quantification of the melanopsin-dependent Post-Illumination Pupil Response (PIPR) after blue light, and evaluated its sensitivity to dark adaptation, time of day, body posture, and light exposure history. Pupil diameter of the left eye was continuously measured during a series of light exposures to the right eye, of which the pupil was dilated using tropicamide 0.5%. The light exposure paradigm consisted of the following five consecutive blocks of five minutes: baseline dark; monochromatic red light (peak wavelength: 630 nm, luminance: 375 cd/m(2)) to maximize the effect of subsequent blue light; dark; monochromatic blue light (peak wavelength: 470 nm, luminance: 375 cd/m(2)); and post-blue dark. PIPR was quantified as the difference between baseline dark pupil diameter and post-blue dark pupil diameter (PIPR-mm). In addition, a relative PIPR was calculated by dividing PIPR by baseline pupil diameter (PIPR-%). In total 54 PIPR assessments were obtained in 25 healthy young adults (10 males, mean age ± SD: 26.9 ± 4.0 yr). From repeated measurements on two consecutive days in 15 of the 25 participants (6 males, mean age ± SD: 27.8 ± 4.3 yrs) test-retest reliability of both PIPR outcome parameters was calculated. In the presence of considerable between-subject differences, both outcome parameters had very high test-retest reliability: Cronbach's α > 0.90 and Intraclass Correlation Coefficient > 0.85. In 12 of the 25 participants (6 males, mean age ± SD: 26.5

  8. Pupil Size Changes as an Active Information Channel for Biofeedback Applications.

    PubMed

    Ehlers, Jan; Strauch, Christoph; Georgi, Juliane; Huckauf, Anke

    2016-09-01

    Pupil size is usually regarded as a passive information channel that provides insight into cognitive and affective states but defies any further control. However, in a recent study (Ehlers et al. 2015) we demonstrate that sympathetic activity indexed by pupil dynamics allows strategic interference by means of simple cognitive techniques. Utilizing positive/negative imaginings, subjects were able to expand pupil diameter beyond baseline variations; albeit with varying degrees of success and only over brief periods. The current study provides a comprehensive replication on the basis of considerable changes to the experimental set-up. Results show that stricter methodological conditions (controlled baseline settings and specified user instructions) strengthen the reported effect, whereas overall performance increases by one standard deviation. Effects are thereby not restricted to pupillary level. Parallel recordings of skin conductance changes prove a general enhancement of induced autonomic arousal. Considering the stability of the results across studies, we conclude that pupil size information exceeds affective monitoring and may constitute an active input channel in human-computer interaction. Furthermore, since variations in pupil diameter reliably display self-induced changes in sympathetic arousal, the relevance of this parameter is strongly indicated for future approaches in clinical biofeedback.

  9. Music chills: The eye pupil as a mirror to music's soul.

    PubMed

    Laeng, Bruno; Eidet, Lise Mette; Sulutvedt, Unni; Panksepp, Jaak

    2016-08-01

    This study evaluated whether music-induced aesthetic "chill" responses, which typically correspond to peak emotional experiences, can be objectively monitored by degree of pupillary dilation. Participants listened to self-chosen songs versus control songs chosen by other participants. The experiment included an active condition where participants made key presses to indicate when experiencing chills and a passive condition (without key presses). Chills were reported more frequently for self-selected songs than control songs. Pupil diameter was concurrently measured by an eye-tracker while participants listened to each of the songs. Pupil size was larger within specific time-windows around the chill events, as monitored by key responses, than in comparison to pupil size observed during 'passive' song listening. In addition, there was a clear relationship between pupil diameter within the chills-related time-windows during both active and passive conditions, thus ruling out the possibility that chills-related pupil dilations were an artifact of making a manual response. These findings strongly suggest that music chills can be visible in the moment-to-moment changes in the size of pupillary responses and that a neuromodulatory role of the central norepinephrine system is thereby implicated in this phenomenon.

  10. Effects of luminal glucose versus nonnutritive infusates on jejunal mass and absorption in the rat.

    PubMed

    Richter, G C; Levine, G M; Shiau, Y F

    1983-11-01

    These studies were designed to better understand the effects of luminal nutrition on intestinal mass and function. Parenterally nourished rats received a midjejunal infusion of either 0.9% saline, 10% glucose, 10% 3-O-methyl glucose, or 30% glucose. A fifth group underwent sham operation. After 7 days, intestinal mass and in vitro glucose and leucine uptake were measured in the intestine just distal to the infusion site. Luminal infusion led to greater intestinal mass in all groups compared to controls, but only the 10% and 30% glucose groups had significantly greater overall glucose uptake. Kinetic analysis revealed a greater apparent maximal transport rate in both glucose groups. The 30% glucose group had a greater apparent maximal transport rate for leucine and permeability for glucose and leucine. These data confirmed that "work load," in addition to luminal nutrition, maintains intestinal mass. However, adaptation of intestinal transport is more specific and appears to be regulated both by substrate metabolism and caloric density.

  11. Microstructure optimization of the composite phase ceramic phosphor for white LEDs with excellent luminous efficacy.

    PubMed

    Tang, Yan Ru; Zhou, Sheng Ming; Yi, Xue Zhuan; Lin, Hui; Zhang, Shuai; Hao, De Ming

    2015-12-01

    The two-phase MgAl2O4-Ce:YAG ceramic phosphor was fabricated by the solid-state reaction in vacuum, and it presented a better luminous efficacy than the single-phase transparent ceramic phosphor when directly combined with the blue light-emitting diodes. The addition of MgAl2O4 implemented the control of the grain sizes and the variation of microstructure, and the microstructure optimization further improved the luminous efficacy of the composite phase ceramic phosphor. A maximum luminous efficacy attaining 99 lm/W at the correlated color temperature 5000 K was obtained. The composite phase ceramic phosphor is expected to be a promising candidate for use in the high-power light source.

  12. A VO2-Based Multifunctional Window with Highly Improved Luminous Transmittance

    NASA Astrophysics Data System (ADS)

    Jin, Ping; Xu, Gang; Tazawa, Masato; Yoshimura, Kazuki

    2002-03-01

    A novel window structure composed of VO2 thermochromic film with TiO2 antireflection (AR) coating was proposed. TiO2 was chosen as the best AR candidatefor reasons that it is an AR material superior to the reported SiO2, and that it is capable to make the window multifunctional with excellent photocatalytic properties. Optical calculation was done for the proposed structure, which predicts a strong enhancement in luminous transmittance (Tlum). A TiO2 (40 nm)/VO2 (50 nm) structure, optimized to a maximum integrated luminous transmittance by calculation, was formed on SiO2 glass by magnetron sputtering. A maximum increase in Tlum by 53% (from 32% to 49%) was experimentally obtained. The proposed window is the most advanced among the similarly reported in being multifunctional with automatic solar/heat control, ultraviolet stopping, and possibly a wide range of photocatalytic functions in addition to being highly luminous transmitting.

  13. Luminal B breast cancer subtype displays a dicotomic epigenetic pattern.

    PubMed

    Bediaga, Naiara G; Beristain, Elena; Calvo, Borja; Viguri, María A; Gutierrez-Corres, Borja; Rezola, Ricardo; Ruiz-Diaz, Irune; Guerra, Isabel; de Pancorbo, Marian M

    2016-01-01

    Luminal B breast tumors have aggressive clinical and biological features, and constitute the most heterogeneous molecular subtype, both clinically and molecularly. Unfortunately, the immunohistochemistry correlate of the luminal B subtype remains still imprecise, and it has now become of paramount importance to define a classification scheme capable of segregating luminal tumors into clinically meaningful subgroups that may be used clinically to guide patient management. With the aim of unraveling the DNA methylation profiles of the luminal subtypes currently being most used in the clinical setting, we have quantified the DNA methylation level of 27,578 CpG sites in 17 luminal B (ER+, Ki67 ≥ 20 % or PgR < 20 % and HER2-), 8 luminal A (ER+ and Ki67 > 20 %) and 4 luminal B-HER2+ (ER+ and HER2+) breast cancer samples by using the Illumina Infinium methylation microarray approach. Unsupervised hierarchical clustering revealed that DNA methylation stratifies luminal B samples in two categories with differing epigenetic and clinical features. One subgroup of luminal B samples showed a methylator phenotype and clustered with the lumB-HER tumors, while the other showed less methylated events, clustered with the luminal A. A 3 CpG marker panel capable of discriminating methylator versus non-methylator luminal B samples was identified and further validated in an independent cohort of patients. Our results provide evidence that DNA methylation and, more specifically, a panel of 3 CpG markers, enables the stratification of luminal B samples in two categories with differing epigenetic and clinical features and support the utilization of this panel for therapeutic stratification of patients with luminal breast cancer.

  14. The pupil dilation response to visual detection

    NASA Astrophysics Data System (ADS)

    Privitera, Claudio M.; Renninger, Laura W.; Carney, Thom; Klein, Stanley; Aguilar, Mario

    2008-02-01

    The pupil dilation reflex is mediated by inhibition of the parasympathetic Edinger-Westphal oculomotor complex and sympathetic activity. It has long been documented that emotional and sensory events elicit a pupillary reflex dilation. Is the pupil response a reliable marker of a visual detection event? In two experiments where viewers were asked to report the presence of a visual target during rapid serial visual presentation (RSVP), pupil dilation was significantly associated with target detection. The amplitude of the dilation depended on the frequency of targets and the time of the detection. Larger dilations were associated with trials having fewer targets and with targets viewed earlier during the trial. We also found that dilation was strongly influenced by the visual task.

  15. Pupil size reveals preparatory processes in the generation of pro-saccades and anti-saccades.

    PubMed

    Wang, Chin-An; Brien, Donald C; Munoz, Douglas P

    2015-04-01

    The ability to generate flexible behaviors to accommodate changing goals in response to identical sensory stimuli is a signature that is inherited in humans and higher-level animals. In the oculomotor system, this function has often been examined with the anti-saccade task, in which subjects are instructed, prior to stimulus appearance, to either automatically look at the peripheral stimulus (pro-saccade) or to suppress the automatic response and voluntarily look in the opposite direction from the stimulus (anti-saccade). Distinct neural preparatory activity between the pro-saccade and anti-saccade conditions has been well documented, particularly in the superior colliculus (SC) and the frontal eye field (FEF), and this has shown higher inhibition-related fixation activity in preparation for anti-saccades than in preparation for pro-saccades. Moreover, the level of preparatory activity related to motor preparation is negatively correlated with reaction times. We hypothesised that preparatory signals may be reflected in pupil size through a link between the SC and the pupil control circuitry. Here, we examined human pupil dynamics during saccade preparation prior to the execution of pro-saccades and anti-saccades. Pupil size was larger in preparation for correct anti-saccades than in preparation for correct pro-saccades and erroneous pro-saccades made in the anti-saccade condition. Furthermore, larger pupil dilation prior to stimulus appearance accompanied saccades with faster reaction times, with a trial-by-trial correlation between dilation size and anti-saccade reaction times. Overall, our results demonstrate that pupil size is modulated by saccade preparation, and neural activity in the SC, together with the FEF, supports these findings, providing unique insights into the neural substrate coordinating cognitive processing and pupil diameter.

  16. Pupils' Perceptions of the Foreign Language Learning Experience.

    ERIC Educational Resources Information Center

    Chambers, Gary N.

    1998-01-01

    Presents findings relating to a study on pupils' perceptions of the in-school foreign language learning experience. The study is part of a longitudinal study on the motivational perspectives of secondary pupils learning German. (Author/VWL)

  17. Pupils' Pressure Models and Their Implications for Instruction.

    ERIC Educational Resources Information Center

    Kariotoglou, P.; Psillos, D.

    1993-01-01

    Discusses a study designed to investigate pupils' conceptions about fluids and particularly liquids in equilibrium, with reference to the concept of pressure. Based upon the results obtained, several mental models of how pupils understand liquids in equilibrium were proposed. (ZWH)

  18. Suzuki Meets Polya: Teaching Mathematics to Young Pupils.

    ERIC Educational Resources Information Center

    Hazlewood, Donald G.; And Others

    1989-01-01

    Describes how Suzuki's methods of teaching young pupils to play the violin can be combined with Polya's ideas on problem solving to teach mathematics to elementary school pupils. Six references are listed. (YP)

  19. Pupil and Salivary Indicators of Autonomic Dysfunction in Autism Spectrum Disorder

    PubMed Central

    Anderson, Christa J.; Colombo, John; Unruh, Kathryn E.

    2013-01-01

    Dysregulated tonic pupil size has been reported in Autism Spectrum Disorder (ASD). Among the possible sources of this dysregulation are disruptions in the feedback loop between norepinephrine (NE) and hypothalamic systems. In the current study, we examined afternoon levels of salivary alpha-amylase (sAA, a putative correlate of NE) and cortisol (used to assess stress-based responses) in two independent samples of children with ASD. We found a larger pupil size and lower sAA levels in ASD, compared to typical and clinical age-matched controls. This was substantiated at the individual level, as sAA levels were strongly correlated with tonic pupil size. Relatively little diurnal variation in sAA taken in the home environment in the ASD group was also observed, while typical controls showed a significant linear increase throughout the day. Results are discussed in terms of potential early biomarkers and the elucidation of underlying neural dysfunction in ASD. PMID:22644965

  20. Constraining Emission Models of Luminous Blazar Sources

    SciTech Connect

    Sikora, Marek; Stawarz, Lukasz; Moderski, Rafal; Nalewajko, Krzysztof; Madejski, Greg; /KIPAC, Menlo Park /SLAC

    2009-10-30

    Many luminous blazars which are associated with quasar-type active galactic nuclei display broad-band spectra characterized by a large luminosity ratio of their high-energy ({gamma}-ray) and low-energy (synchrotron) spectral components. This large ratio, reaching values up to 100, challenges the standard synchrotron self-Compton models by means of substantial departures from the minimum power condition. Luminous blazars have also typically very hard X-ray spectra, and those in turn seem to challenge hadronic scenarios for the high energy blazar emission. As shown in this paper, no such problems are faced by the models which involve Comptonization of radiation provided by a broad-line-region, or dusty molecular torus. The lack or weakness of bulk Compton and Klein-Nishina features indicated by the presently available data favors production of {gamma}-rays via up-scattering of infrared photons from hot dust. This implies that the blazar emission zone is located at parsec-scale distances from the nucleus, and as such is possibly associated with the extended, quasi-stationary reconfinement shocks formed in relativistic outflows. This scenario predicts characteristic timescales for flux changes in luminous blazars to be days/weeks, consistent with the variability patterns observed in such systems at infrared, optical and {gamma}-ray frequencies. We also propose that the parsec-scale blazar activity can be occasionally accompanied by dissipative events taking place at sub-parsec distances and powered by internal shocks and/or reconnection of magnetic fields. These could account for the multiwavelength intra-day flares occasionally observed in powerful blazars sources.

  1. Blur tolerance for luminance and chromatic stimuli.

    PubMed

    Wuerger, S M; Owens, H; Westland, S

    2001-06-01

    We investigated the blur tolerance of human observers for stimuli modulated along the isoluminant red-green, the isoluminant yellow-blue, and the luminance (black-white) direction in color space. We report the following results: (i) Blur difference thresholds for red-green and luminance stimuli (of equal cone contrast) are very similar and as low as 0.5 min of visual angle; for yellow-blue the lowest blur thresholds are much higher (1.5 min of visual angle). (ii) The smallest blur thresholds are found for slightly blurred square waves (reference blur of 1 arc min) and not for sharp edges. (iii) Blur thresholds for red-green and black-white follow a Weber law for reference (pedestal) blurs greater than the optimum blur. (iv) Using the model proposed by Watt and Morgan [Vision Res. 24, 1387 (1984)] we estimated the internal blur of the visual system for the black-white and the red-green color directions and arrived at the following estimates: 1.2 arc min for black-white stimuli at 10% contrast and 0.9 arc min for red-green stimuli at 10% cone contrast. Blur tolerance for yellow-blue is independent of external blur and cannot be predicted by the model. (v) The contrast dependence of blur sensitivity is similar for red-green and luminance modulations (slopes of -0.15 and -0.16 in log-log coordinates, respectively) and slightly stronger for yellow-blue (slope = -0.75). Blur discrimination thresholds are not predicted by the contrast sensitivity function of the visual system. Our findings are useful for predicting blur tolerance for complex images and provide a spatial frequency cutoff point when Gaussian low-pass filters are used for noise removal in colored images. They are also useful as a baseline for the study of visual disorders such as amblyopia.

  2. Adaptive optics scanning ophthalmoscopy with annular pupils.

    PubMed

    Sulai, Yusufu N; Dubra, Alfredo

    2012-07-01

    Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections.

  3. Adaptive optics scanning ophthalmoscopy with annular pupils

    PubMed Central

    Sulai, Yusufu N.; Dubra, Alfredo

    2012-01-01

    Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections. PMID:22808435

  4. Differences in Pupil Achievement in Kenya: Implications for Policy and Practice

    ERIC Educational Resources Information Center

    Hungi, Njora; Thuku, Florence W.

    2010-01-01

    In this study the authors employed multilevel analyses procedures to examine pupil, class and school levels factors that influenced pupil achievement in Kenya. Pupil's age, pupil's socioeconomic background and pupil-teacher ratio were important factors in the prediction of pupil achievement. The provinces with the largest between-school variation…

  5. Evolving Our Evaluation of Luminous Environments

    NASA Technical Reports Server (NTRS)

    Clark, Toni

    2016-01-01

    The advance in solid state light emitting technologies and optics for lighting and visual communication necessitates the evaluation of how NASA envisions spacecraft lighting architectures and how NASA uses industry standards for the design and evaluation of lighting systems. Current NASA lighting standards and requirements for existing architectures focus on the separate ability of a lighting system to throw light against a surface or the ability of a display system to provide the appropriate visual contrast. This project investigated large luminous surface lamps as an alternative or supplement to overhead lighting. The efficiency of the technology was evaluated for uniformity and power consumption.

  6. Photometric monitoring of Luminous Blue Variables

    NASA Astrophysics Data System (ADS)

    Buemi, Carla; Distefano, Elisa; Leto, Paolo; Schillirò, Francesco; Trigilio, Corrado; Umana, Grazia; Bernabei, Stefano; Cutispoto, Giuseppe; Messina, Sergio

    2011-01-01

    We present some preliminary results from our program of intensive near-infrared photometric monitoring of a sample of confirmed and candidate Luminous Blue Variables (LBVs) conducted from 2008 to 2010. Clear long-term variability has been observed for Wray 17-96 and V481 Sct, with overall brightness variation greater than 1 mag in the J band. Other sources, such as LBV 1806-20 showed detectable variability with amplitudes of few tenths of a magnitude with a time-scale of about 60 days.

  7. Relative roles of luminance and fixation in inducing dissociated vertical divergence.

    PubMed

    Ghadban, Rafif; Liebermann, Laura; Klaehn, Lindsay D; Holmes, Jonathan M; Brodsky, Michael C

    2014-12-23

    We evaluated the roles of luminance and fixation in the pathophysiology of dissociated vertical divergence (DVD). Vertical eye position was measured in 6 subjects with DVD (ages 11-47 years, 5 females) and 6 controls (ages 16-40 years, 5 females) using video-oculography (VOG) under conditions of change in fixation and luminance. Subjects with DVD showed the following VOG responses. When fixation was precluded with a translucent filter and bright light was shone into one eye to produce a marked binocular luminance disparity, we found some subjects had a small induced vertical divergence causing the illuminated eye to be lower than the nonilluminated eye (mean -1.6° ± 1.5°, P = 0.06 compared to no vertical divergence using the signed rank test). When fixation was precluded with a translucent filter, while alternate occlusion produced a mild binocular luminance disparity, we found a smaller vertical divergence of the eyes that was not statistically significant (1.2° ± 2.1°, P = 0.3). When alternate occlusion produced reversal of monocular fixation in the dark (with essentially no change in peripheral luminance disparity), there was a significant vertical divergence movement causing the covered eye to be relatively higher than the uncovered eye (7.2° ± 3.1°, P = 0.03). The amplitude of this vertical divergence was similar to that measured under conditions of alternate occlusion in a lighted room (where there also was a significant average relative upward movement of the covered eye of 8.1° ± 2.9°, P = 0.03). Control subjects showed no vertical divergence under any testing conditions. Dissociated vertical divergence is mediated primarily by changes in fixation and only to a minor degree by binocular luminance disparity. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  8. Relative Roles of Luminance and Fixation in Inducing Dissociated Vertical Divergence

    PubMed Central

    Ghadban, Rafif; Liebermann, Laura; Klaehn, Lindsay D.; Holmes, Jonathan M.; Brodsky, Michael C.

    2015-01-01

    Purpose. We evaluated the roles of luminance and fixation in the pathophysiology of dissociated vertical divergence (DVD). Methods. Vertical eye position was measured in 6 subjects with DVD (ages 11–47 years, 5 females) and 6 controls (ages 16–40 years, 5 females) using video-oculography (VOG) under conditions of change in fixation and luminance. Results. Subjects with DVD showed the following VOG responses. When fixation was precluded with a translucent filter and bright light was shone into one eye to produce a marked binocular luminance disparity, we found some subjects had a small induced vertical divergence causing the illuminated eye to be lower than the nonilluminated eye (mean −1.6° ± 1.5°, P = 0.06 compared to no vertical divergence using the signed rank test). When fixation was precluded with a translucent filter, while alternate occlusion produced a mild binocular luminance disparity, we found a smaller vertical divergence of the eyes that was not statistically significant (1.2° ± 2.1°, P = 0.3). When alternate occlusion produced reversal of monocular fixation in the dark (with essentially no change in peripheral luminance disparity), there was a significant vertical divergence movement causing the covered eye to be relatively higher than the uncovered eye (7.2° ± 3.1°, P = 0.03). The amplitude of this vertical divergence was similar to that measured under conditions of alternate occlusion in a lighted room (where there also was a significant average relative upward movement of the covered eye of 8.1° ± 2.9°, P = 0.03). Control subjects showed no vertical divergence under any testing conditions. Conclusions. Dissociated vertical divergence is mediated primarily by changes in fixation and only to a minor degree by binocular luminance disparity. PMID:25537206

  9. Hybrid pupil filter design using Bessel series

    NASA Astrophysics Data System (ADS)

    Ochoa, Noé Alcalá; García-Márquez, J.; González-Vega, A.

    2011-09-01

    We propose a simple method of designing pupil filters for transverse super-resolution. For this end we represent the amplitude Point Spread Function (PSF) as a series expansion, constructed from the Fourier transform of a basis of Bessel functions. With this representation we optimize the intensity PSF according to certain desired characteristics, such as a smaller disk diameter than the corresponding, clear aperture, Airy disk. It is proved that by using few basis functions, it is possible to design pupils with similar or better PSF characteristics than previously reported.

  10. An Exploratory Study on How Primary Pupils Approach Systems

    ERIC Educational Resources Information Center

    Koski, Marja-Ilona; de Vries, Marc

    2013-01-01

    This paper presents a study of systems thinking among 27 primary pupils (8-10 years old) and their teacher. The study included a pre-test for the teacher and the pupils, lesson planning, the actual lesson and a post-test for the pupils. The research focused on finding an answer to three questions: (1) do pupils see a system as a structure…

  11. System and measurement method for binocular pupillometry to study pupil size variability.

    PubMed

    Nowak, Wioletta; Żarowska, Anna; Szul-Pietrzak, Elżbieta; Misiuk-Hojło, Marta

    2014-06-05

    An objective and noninvasive examination of pupil size variability can be used to assess the activity of the autonomous nervous system. We designed a system that enables binocular, fast, and accurate recordings of different types of pupil variabilities, which are synchronous with other biosignals. This type of measurement system is needed to extend the scope of pupillometry applications. In the proposed system, the left and right eyes are independently and interchangeably illuminated to generate alternating images, which are successively acquired by a single camera. The system is composed of four functional modules: the image acquisition module, the image processing unit, the light stimulator, and the controller. The proposed image processing algorithm approximates the shape of the pupil using the best-fit ellipse. The user control panel (controller) precisely sets the stimuli parameters and controls the entire measurement procedure. The computer-based binocular system records the pupil size during the pupil light reflexes (direct and indirect) and spontaneous pupil size fluctuations, at a sampling rate up to 75 Hz, with a resolution better than 0.02 mm. Our initial laboratory tests confirmed that the new system is fast and precise (system accuracy better than 0.5% and repeatability better than 4%). The proposed system's unique geometry and construction, and the method it uses to detect images from each eye, allows us to monitor the right and left eyes using a single camera with no overlap between the images. The system does not require a very experienced operator, because it is relatively simple and easy to use. Importantly, it is comfortable for the subjects. Additionally, the presented system can operate with other bio-measurement systems using a synchronous signal. These system capabilities can expand the scope of pupillometry research applications.

  12. Pupil Welfare in Finnish Schools -- Communal or Falling Apart?

    ERIC Educational Resources Information Center

    Koskela, Teija; Määttä, Kaarina; Uusiautti, Satu

    2013-01-01

    The need for pupil welfare has increased in schools as has the need to renew the traditional teacher's work. The purpose of this article is to find out how committed the teachers are to pupil welfare work and how the school organisation supports pupil welfare work structurally and practically. The original research was carried out in northern…

  13. Pupils' Perspectives on the Lived Pedagogy of the Classroom

    ERIC Educational Resources Information Center

    Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse; Hilppö, Jaakko

    2015-01-01

    This paper is based on a pedagogical action research initiative that explores what constitutes the "lived pedagogy" of the classroom from the pupils' perspective. Photography and group interviews were utilised to allow pupils to express their perspectives. The results show that pupils considered situations meaningful when they were able…

  14. What Makes an Exemplary Teacher of Science? The Pupils' Perspective

    ERIC Educational Resources Information Center

    Wilson, Helen; Mant, Jenny

    2011-01-01

    Questionnaires were completed by 5044 12-year-old pupils in Oxfordshire state schools and initially used to identify classes where the pupils were more positive and enthusiastic about their science lessons than the majority. The teachers of these classes were identified and the views of their pupils as to what happens in their science lessons…

  15. Pupils' Perspectives on the Lived Pedagogy of the Classroom

    ERIC Educational Resources Information Center

    Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse; Hilppö, Jaakko

    2015-01-01

    This paper is based on a pedagogical action research initiative that explores what constitutes the "lived pedagogy" of the classroom from the pupils' perspective. Photography and group interviews were utilised to allow pupils to express their perspectives. The results show that pupils considered situations meaningful when they were able…

  16. Assisting Pupils in Mathematics Achievement (The Common Core Standards)

    ERIC Educational Resources Information Center

    Ediger, Marlow

    2011-01-01

    Mathematics teachers must expect reasonably high standards of achievement from pupils. Too frequently, pupils attain at a substandard level and more optimal achievement is necessary. Thus, pupils should have self esteem needs met in the school and classroom setting. Thus, learners feel that mathematics is worthwhile and effort must be put forth to…

  17. Pupil Welfare in Finnish Schools -- Communal or Falling Apart?

    ERIC Educational Resources Information Center

    Koskela, Teija; Määttä, Kaarina; Uusiautti, Satu

    2013-01-01

    The need for pupil welfare has increased in schools as has the need to renew the traditional teacher's work. The purpose of this article is to find out how committed the teachers are to pupil welfare work and how the school organisation supports pupil welfare work structurally and practically. The original research was carried out in northern…

  18. What Happens When I Write? Pupils' Writing about Writing

    ERIC Educational Resources Information Center

    Barbeiro, Luis Filipe

    2011-01-01

    This article presents pupils' awareness of writing as elicited through a metawriting task, in other words a task in which pupils from the third, fourth and sixth forms (grades) were required to write about writing. The analysis of the texts revealed the pupils' increasing ability to write texts focusing on writing and on the subject's relationship…

  19. On Pupils' Self-Confidence in Mathematics: Gender Comparisons

    ERIC Educational Resources Information Center

    Nurmi, Anu; Hannula, Markku; Maijala, Hanna; Pehkonen, Erkki

    2003-01-01

    In this paper we will concentrate on pupils' self-confidence in mathematics, which belongs to pupils' mathematical beliefs in themselves, and beliefs on achievement in mathematics. Research described consists of a survey of more than 3000 fifth-graders and seventh-graders. Furthermore, 40 pupils participated in a qualitative follow-up study…

  20. Gender "Matters" in the Primary Classroom: Pupils' and Teachers' Perspectives

    ERIC Educational Resources Information Center

    Skelton, C.; Carrington, B.; Francis, B.; Hutchings, M.; Read, B.; Hall, I.

    2009-01-01

    A recent project involving Year 3 (seven-eight year-old) pupils and their teachers revealed that "gender matters" differently to boys and girls, and teachers. The study sought to elicit whether pupils and their teachers felt the gender of a teacher mattered to their experiences of schooling. Pupils were concerned about how effective…

  1. Guidelines For Pupil Services. Volume 17, Number 1, Spring 1979.

    ERIC Educational Resources Information Center

    Erpenbach, William J., Ed.

    1979-01-01

    This guide offers articles giving advice and information about pupil services. It serves to blend theory and practice in reporting on promising practices in the pupil services disciplines in Wisconsin. Material and suggestions are adaptable elsewhere, and serve to stimulate professional activity in the pupil services field. Major articles focus on…

  2. Elementary Public School Pupil Rating of Teacher Effectiveness.

    ERIC Educational Resources Information Center

    Follman, John

    1995-01-01

    Reviews research on elementary school pupils' ratings of teacher effectiveness. Concludes adequate research exists to generalize that pupils can rate reliably, pupils may be no more vulnerable than others to rating leniency and halo, psychometric characteristics and factor structures of rating scales resemble those of college students,…

  3. Elementary Public School Pupil Rating of Teacher Effectiveness.

    ERIC Educational Resources Information Center

    Follman, John

    1995-01-01

    Reviews research on elementary school pupils' ratings of teacher effectiveness. Concludes adequate research exists to generalize that pupils can rate reliably, pupils may be no more vulnerable than others to rating leniency and halo, psychometric characteristics and factor structures of rating scales resemble those of college students,…

  4. Cochlear Implanted Pupils in Scottish Schools: 4-Year School Attainment

    ERIC Educational Resources Information Center

    Thoutenhoofd, Ernst

    2006-01-01

    The Achievements of Deaf Pupils in Scotland (ADPS) project has been tracking the educational attainment of deaf pupils in Scotland's schools since 2000. At the time of writing, the database contains records for 1,752 deaf pupils (2000--2005). Here 4-year aggregate educational attainment data are reported for a subset of 152 school-aged deaf pupils…

  5. Academic Outcomes in School Classes with Markedly Disruptive Pupils

    ERIC Educational Resources Information Center

    Bru, Edvin

    2009-01-01

    The aim of the present research is to investigate the degree to which average academic outcomes in secondary school classes are associated with the inclusion of markedly disruptive pupils. Findings are based on two separate studies among pupils in Norwegian secondary schools. The first study included a relatively large sample of 2,332 pupils from…

  6. Turkish Pupils' Conceptions of the Particulate Nature of Matter

    ERIC Educational Resources Information Center

    Boz, Yezdan

    2006-01-01

    The purpose of this research study is to explore year 6, 8 & 11 (13, 15 and 17 years old respectively) Turkish pupils' views about the particulate nature of matter within the context of phase changes. About 300 pupils participated in the study. Questionnaires distributed to year 6, 8 and 11 pupils included 6-item open-ended questions about (a)…

  7. Pupils' Attitudes toward Chemistry in Two Types of Czech Schools

    ERIC Educational Resources Information Center

    Kubiatko, Milan; Balatova, Kristyna; Fancovicova, Jana; Prokop, Pavol

    2017-01-01

    Chemistry is a school subject that is not viewed favorably among pupils. Before we can improve pupils' attitudes toward chemistry, it is important to find out the problem as to why the attitudes are relatively negative. The research was focused on Czech lower secondary and secondary grammar school pupils' attitudes to the subject of chemistry.…

  8. Pupils' Humour Directed at Teachers: Its Types and Functions

    ERIC Educational Resources Information Center

    Šedová, Klára

    2013-01-01

    Based on an analysis of 137 texts written by pupils, this paper examines pupils' humour directed at teachers, its types and social functions. The collected data are divided into three categories that describe different modes of teachers as targets of pupils' humour. The first mode describes teachers as unintentionally comical, the second as duped…

  9. Pupil Mobility, Attainment and Progress in Primary School

    ERIC Educational Resources Information Center

    Strand, Steve; Demie, Feyisa

    2006-01-01

    This article presents an analysis of the association between pupil mobility and educational attainment in the 2002 national end of Key Stage 2 (KS2) tests for 11-year-old pupils in an inner London education authority. The results show that pupil mobility is strongly associated with low attainment in the end of key stage tests. However, the…

  10. Cyberbullying: Its Nature and Impact in Secondary School Pupils

    ERIC Educational Resources Information Center

    Smith, Peter K.; Mahdavi, Jess; Carvalho, Manuel; Fisher, Sonja; Russell, Shanette; Tippett, Neil

    2008-01-01

    Background: Cyberbullying describes bullying using mobile phones and the internet. Most previous studies have focused on the prevalence of text message and email bullying. Methods: Two surveys with pupils aged 11-16 years: (1) 92 pupils from 14 schools, supplemented by focus groups; (2) 533 pupils from 5 schools, to assess the generalisability of…

  11. Modulation of stimulus contrast on the human pupil orienting response.

    PubMed

    Wang, Chin-An; Munoz, Douglas P

    2014-09-01

    The sudden appearance of a novel stimulus initiates a series of responses to orient the body for appropriate actions, including not only shifts of gaze and attention, but also transient pupil dilation. Modulation of pupil dynamics by stimulus properties is less understood, although its effects on other components of orienting have been extensively explored. Microstimulation of the superior colliculus evoked transient pupil dilation, and the initial component of pupil dilation evoked by microstimulation was similar to that elicited by the presentation of salient sensory stimuli, suggesting a coordinated role of the superior colliculus on this behavior, although evidence in humans is yet to be established. To examine pupil orienting responses in humans, we presented visual stimuli while participants fixated on a central visual spot. Transient pupil dilation in humans was elicited after presentation of a visual stimulus in the periphery. The evoked pupil responses were modulated systematically by stimulus contrast, with faster and larger pupil responses triggered by higher contrast stimuli. The pupil response onset latencies for high contrast stimuli were similar to those produced by the light reflex and significantly faster than the darkness reflex, suggesting that the initial component of pupil dilation is probably mediated by inhibition of the parasympathetic pathway. The contrast modulation was pronounced under different levels of baseline pupil size. Together, our results demonstrate visual contrast modulation on the orienting pupil response in humans.

  12. Learning Mathematics--Letting the Pupils Have Their Say

    ERIC Educational Resources Information Center

    Lee, Clare; Johnston-Wilder, Sue

    2013-01-01

    Pupil voice is an emerging force for change and improvement in many UK schools, but what is not fully understood is how best to access pupil voice within the specific context of secondary mathematics departments. This paper presents a research project designed to use pupils as co-researchers in increasing knowledge about how to improve learning in…

  13. Pupils' Humour Directed at Teachers: Its Types and Functions

    ERIC Educational Resources Information Center

    Šedová, Klára

    2013-01-01

    Based on an analysis of 137 texts written by pupils, this paper examines pupils' humour directed at teachers, its types and social functions. The collected data are divided into three categories that describe different modes of teachers as targets of pupils' humour. The first mode describes teachers as unintentionally comical, the second as duped…

  14. Turkish Pupils' Conceptions of the Particulate Nature of Matter

    ERIC Educational Resources Information Center

    Boz, Yezdan

    2006-01-01

    The purpose of this research study is to explore year 6, 8 & 11 (13, 15 and 17 years old respectively) Turkish pupils' views about the particulate nature of matter within the context of phase changes. About 300 pupils participated in the study. Questionnaires distributed to year 6, 8 and 11 pupils included 6-item open-ended questions about (a)…

  15. What Happens When I Write? Pupils' Writing about Writing

    ERIC Educational Resources Information Center

    Barbeiro, Luis Filipe

    2011-01-01

    This article presents pupils' awareness of writing as elicited through a metawriting task, in other words a task in which pupils from the third, fourth and sixth forms (grades) were required to write about writing. The analysis of the texts revealed the pupils' increasing ability to write texts focusing on writing and on the subject's relationship…

  16. Cyberbullying: Its Nature and Impact in Secondary School Pupils

    ERIC Educational Resources Information Center

    Smith, Peter K.; Mahdavi, Jess; Carvalho, Manuel; Fisher, Sonja; Russell, Shanette; Tippett, Neil

    2008-01-01

    Background: Cyberbullying describes bullying using mobile phones and the internet. Most previous studies have focused on the prevalence of text message and email bullying. Methods: Two surveys with pupils aged 11-16 years: (1) 92 pupils from 14 schools, supplemented by focus groups; (2) 533 pupils from 5 schools, to assess the generalisability of…

  17. Luminal-B breast cancer and novel therapeutic targets

    PubMed Central

    2011-01-01

    Gene expression profiling has led to a new molecular classification of breast cancer characterized by four intrinsic subtypes: basal-like, HER2-positive, luminal A, and luminal B. Despite expressing estrogen receptor, the luminal-B subtype confers increased risk of early relapse with endocrine therapy compared with the luminal-A subtype. Although luminal-B definitions vary, the hallmark appears to be increased expression of proliferation-related genes. Several biological pathways are identified as possible contributors to the poor outcomes, and novel agents targeting these pathways are being developed with aims to improve survival. We review the definition of luminal-B breast cancer, its pathological and clinical features, and potential targets for treatment. PMID:22217398

  18. Luminance cues constrain chromatic blur discrimination in natural scene stimuli.

    PubMed

    Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

    2013-03-22

    Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties.

  19. Peripheral visual response time and retinal luminance-area relations

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1975-01-01

    Experiments were undertaken to elucidate the stimulus luminance-retinal area relationship that underlies response time (RT) behavior. Mean RT was significantly faster to stimuli imaged beyond about 70 deg of arc from the fovea when their luminance was increased by an amount equal to the foveal stimulus luminance multiplied by the cosine of the angle between the peripheral stimuli and the line of sight. This and additional data are discussed in relation to previous psychophysical data and to possible response mechanisms.

  20. Peripheral visual response time and retinal luminance-area relations

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1975-01-01

    Experiments were undertaken to elucidate the stimulus luminance-retinal area relationship that underlies response time (RT) behavior. Mean RT was significantly faster to stimuli imaged beyond about 70 deg of arc from the fovea when their luminance was increased by an amount equal to the foveal stimulus luminance multiplied by the cosine of the angle between the peripheral stimuli and the line of sight. This and additional data are discussed in relation to previous psychophysical data and to possible response mechanisms.

  1. A new interpretation of luminous blue stars

    NASA Technical Reports Server (NTRS)

    Stothers, R.

    1976-01-01

    A major revision of current theoretical ideas about the brightest blue stars must be made if Carson's (1976) radiative opacities are adopted in stellar models. Unlike earlier opacities, these exhibit a large 'bump' due to CNO ionization, which leads to very strong central condensation, convective instability, and pulsational instability in hot diffuse stellar envelopes. Despite a number of theoretical uncertainties, the new picture of the structure of very luminous stars is reasonably successful in accounting for a variety of previously unexplained observations. The stellar models for the phase of core hydrogen burning predict large radii and rather cool effective temperatures for O stars and a spreading out of the main-sequence band in the H-R diagram toward luminous cool supergiants for masses higher than about 20 solar masses. In massive X-ray binary systems, circular orbits and supergiant-like visual companions are expected to be quite common. Long-period variability is predicted to exist for massive blue supergiants of luminosity class Ia. The models for helium stars predict large radii and rather cool effective temperatures for Wolf-Rayet stars, as well as multimodal pulsational instability and, possibly, surface turbulence for these stars.

  2. ERP-pupil size correlations reveal how bilingualism enhances cognitive flexibility.

    PubMed

    Kuipers, Jan-Rouke; Thierry, Guillaume

    2013-01-01

    A bilingual upbringing has been shown to enhance executive control, but the neural mechanisms underpinning such effect are essentially unknown. Here, we investigated whether monolingual and bilingual toddlers differ in semantic processing efficiency and their allocation of attention to expected and unexpected visual stimuli. We simultaneously recorded event-related brain potentials (ERPs) and pupil size in monolingual and bilingual toddlers presented with (spoken) word-picture pairs. Although ERP effects elicited by semantic relatedness were indistinguishable between the two children groups, pictures unrelated to the preceding word evoked greater pupil dilation than related pictures in bilinguals, but not in monolinguals. Furthermore, increasing pupil dilation to unrelated pictures was associated with decreasing N400 amplitude in bilinguals, whereas the monolingual toddlers showed the opposite association. Hence, attention to unexpected stimuli seems to hamper semantic integration in monolinguals, but to facilitate semantic integration in bilinguals, suggesting that bilingual toddlers are more tolerant to variation in word-referent mappings. Given the link between pupil dilation and norepinephrine-driven cognitive efficiency, correlations between ERP amplitude and concurrent pupil dilation provide new insights into the neural bases of the bilingual cognitive advantage. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Teacher management behaviors and pupil task involvement during small group laboratory activities

    NASA Astrophysics Data System (ADS)

    Beasley, Warren

    A major concern of many beginning and experienced teachers is that of classroom management and control. This article describes recent research into defining classroom management procedures that are used by high school science teachers and their relationship to pupil ontaskness. The classroom is conceptualized as a manipulable behavioral system. This construct arises directly from Barker's (1968) ecological psychology, the classroom and its occupants being conceptualized as a behavior setting. The behaviors of the teacher and the pupils are an integral part of the unit (behavior setting), which in turn coerces certain behaviors from its participants. Thus settings, and, in particular, subsettings, are seen as more important determiners of social behavior than the personality of individual teacher or pupil. The methodology employed in this research has involved the extensive use of video in naturalistic science classrooms. Tapes of both teacher and pupil behaviors were continuously and independently recorded. Intensive analysis using electronic recording instruments interfaced with the computer has allowed the collection and sophisticated analysis of the observational data. Data relating to teacher management behavior in small group settings have been analyzed and the relationships to pupil task involvement have been explored.

  4. Covariation of Color and Luminance Facilitate Object Individuation in Infancy

    PubMed Central

    Woods, Rebecca J.; Wilcox, Teresa

    2013-01-01

    The ability to individuate objects is one of our most fundamental cognitive capacities. Recent research has revealed that when objects vary in color or luminance alone, infants fail to individuate those objects until 11.5 months. However, color and luminance frequently covary in the natural environment, thus providing a more salient and reliable indicator of distinct objects. For this reason, we propose that infants may be more likely to individuate when objects vary in both color and luminance. Using the narrow-screen task of Wilcox and Baillargeon (1998a), in Experiment 1 we assessed 7.5-month-old infants' ability to individuate uniformly colored objects that varied in both color and luminance or luminance alone. Experiment 2 further explored the link between color and luminance by assessing infants' ability to use pattern differences that included luminance or color to individuate objects. Results indicated that infants individuated objects only when covariations in color and luminance were used. These studies add to a growing body of literature investigating the interaction of color and luminance in object processing in infants and have implications for developmental changes in the nature and content of infants' object representations. PMID:20438179

  5. Adaptive display luminance for viewing smartphones under low illuminance.

    PubMed

    Na, Nooree; Suk, Hyeon-Jeong

    2015-06-29

    The study investigates the optimal display luminance for viewing smartphones in conditions of low illuminance. This proposes a model of adaptive display in that display luminance changes gradually with the passage of watching time. It starts at a fairly low display luminance of 10 cd/m2, and after 10 seconds, the luminance increases slowly until it reaches 40 cd/m2 for 20 seconds and maintains the luminance. For the development of the model, an experiment was conducted to identify the optimal luminance for initial viewing and that for continuous viewing, as well as the change speed of display luminance. In order to validate the model, users' subjective judgments and activation of alpha rhythm were observed, and the result confirmed the superiority of the adaptive display luminance compared to the current display luminance in terms of physiological comfort and psychological satisfaction. It is expected that this study contributes to the pleasing use of displays at night under low illuminance by applying to diverse types of display devices.

  6. Luminance-model-based DCT quantization for color image compression

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Peterson, Heidi A.

    1992-01-01

    A model is developed to approximate visibility thresholds for discrete cosine transform (DCT) coefficient quantization error based on the peak-to-peak luminance of the error image. Experimentally measured visibility thresholds for R, G, and B DCT basis functions can be predicted by a simple luminance-based detection model. This model allows DCT coefficient quantization matrices to be designed for display conditions other than those of the experimental measurements: other display luminances, other veiling luminances, and other spatial frequencies (different pixel spacings, viewing distances, and aspect ratios).

  7. Reducing luminance intensity can improve motion perception in noise

    PubMed Central

    Allard, Rémy; Arleo, Angelo

    2017-01-01

    Visual perception generally improves under brighter environments. For instance, motion sensitivity is known to improve with luminance intensity especially at high temporal frequencies. However, the current study counter-intuitively shows that increasing luminance intensity can impair motion sensitivity in noise. Motion sensitivity was measured with and without noise added to a drifting Gabor patch as a function of the temporal frequency and luminance intensity. As expected, motion sensitivity in absence of noise reached a ceiling performance at a relatively low luminance intensity (about 35 td) for low temporal frequencies and improved with luminance intensity up to the highest luminance intensity tested (353 td) for high temporal frequencies. In noise, reducing mean luminance intensity facilitated motion sensitivity (up to a factor of about 1.7) for temporal frequencies up to 7.5 Hz and impaired sensitivity at higher temporal frequencies (15 and 30 Hz). We conclude that reducing luminance intensity is effectively equivalent to applying a low-pass filter, which can improve motion sensitivity in noise to low and middle temporal frequencies. This counterintuitive facilitation effect can be explained by two known properties of the visual system: decreasing luminance intensity impairs the visibility of high temporal frequencies (equivalent to a low-pass filter) and motion detectors are broadly tuned. PMID:28220883

  8. Night vision goggle luminance disparity and the Pulfrich phenomenon

    NASA Astrophysics Data System (ADS)

    Pinkus, Alan; Task, Harry L.

    2004-09-01

    When night vision goggle (NVG) image intensifier tubes (I2Ts) are replaced during maintenance, the output luminances of the two channels must not exceed a ratio of 1.5 (brighter channel luminance divided by the dimmer channel luminance) in order to meet the current allowed binocular luminance disparity specification. Two studies were performed to investigate the validity of this requirement. The first study estimated thresholds of binocular luminance disparity detection for observers looking through NVGs. For eight observers, the 25% corrected-for-chance probability of detecting an ocular luminance difference, yielded an average ratio of 1.43 indicating that the current 1.5 specification is perhaps too loose. The second study investigated the Pulfrich phenomenon, a pseudo-stereo effect that can be induced by presenting luminance imbalances to the eyes. This study created NVG luminance imbalances using neutral density (ND) filters and then investigated whether or not the various imbalance levels were sufficient to cause the Pulfrich phenomenon to be perceived. Results indicated an imbalance ratio of 1.10 was insufficient to cause the effect to be seen, but a ratio of 1.26 was sufficient (p <= 0.0003) for the effect to be seen, at least part of the time. Based on these results, it is apparent the allowed binocular luminance disparity ratio should probably be tightened to at least 1.3 with a goal of 1.2.

  9. Risk-based learning games improve long-term retention of information among school pupils.

    PubMed

    Devonshire, Ian M; Davis, Jenny; Fairweather, Sophie; Highfield, Lauren; Thaker, Chandni; Walsh, Ashleigh; Wilson, Rachel; Hathway, Gareth J

    2014-01-01

    Risk heightens motivation and, if used appropriately, may have the potential to improve engagement in the classroom. We have developed a risk-based learning game for school pupils in order to test whether such learning games can improve later recall of information. The study was performed during a series of public engagement workshops delivered by undergraduate students. Undergraduate neuroscience students delivered 90-minute science workshops to 9-10 year old school pupils (n = 448) that were divided into 'Risk', 'No risk' and 'Control' classes. 'Risk' classes received periodic multiple-choice questions (MCQs) during the workshops which required small teams of pupils to assign tokens to the answer(s) they believed to be correct. Tokens assigned to the correct answer were returned to the group and an equal number given back as a prize; tokens assigned to incorrect answers were lost. Participation was incentivised by the promise of a brain-related prize to the team with the most tokens at the end of the workshop. 'No risk' classes received MCQs without the risk component whilst the 'Control' classes received no MCQs. When presented with a neuroscience quiz based on workshop content at the end of the workshop, pupils in the 'Risk' classes exhibited significantly greater recall of information one week later. Quiz scores were higher than scores from the day of the workshop which suggested pupils may have discussed the workshop content outside of the classroom, thereby increasing knowledge over and above what was learned during the workshop. This is supported by feedback from pupils in 'Risk' classes which indicated that 'Risk' workshops were more interesting than 'No risk' and 'Control' workshops. These data suggest that there is a role for risk in the classroom but further investigations are required to elucidate the causal mechanisms of improved retention of information.

  10. School and Pupil Effects on Secondary Pupils' Feelings of Safety in School, around School, and at Home

    ERIC Educational Resources Information Center

    Mooij, Ton; Fettelaar, Daan

    2013-01-01

    In line with fear of crime research, schools should be secure places where pupils feel safe in order to function well. Various types of risk and promotive variables at school and pupil level may differently influence a pupil's feelings of safety in school, the school surroundings, and at home. The aim is to elaborate and test a theoretical…

  11. Teachers on Perceived Traits and Academic Achievements of Regular Pupils and Pupils with Special Needs in Mainstream Primary Schools

    ERIC Educational Resources Information Center

    Lesar, Irena; Cuk, Ivan; Pecek, Mojca

    2014-01-01

    When looking for answers to the question of academic (non)achievement of regular pupils and pupils with special needs, it is necessary to take into account the extraordinary complexity of factors, ranging from psychological across instructional to home environment variables. The academic achievement is not only a reflection of the pupil's…

  12. Teachers on Perceived Traits and Academic Achievements of Regular Pupils and Pupils with Special Needs in Mainstream Primary Schools

    ERIC Educational Resources Information Center

    Lesar, Irena; Cuk, Ivan; Pecek, Mojca

    2014-01-01

    When looking for answers to the question of academic (non)achievement of regular pupils and pupils with special needs, it is necessary to take into account the extraordinary complexity of factors, ranging from psychological across instructional to home environment variables. The academic achievement is not only a reflection of the pupil's…

  13. School and Pupil Effects on Secondary Pupils' Feelings of Safety in School, around School, and at Home

    ERIC Educational Resources Information Center

    Mooij, Ton; Fettelaar, Daan

    2013-01-01

    In line with fear of crime research, schools should be secure places where pupils feel safe in order to function well. Various types of risk and promotive variables at school and pupil level may differently influence a pupil's feelings of safety in school, the school surroundings, and at home. The aim is to elaborate and test a theoretical…

  14. Objective lens simultaneously optimized for pupil ghosting, wavefront delivery and pupil imaging

    NASA Technical Reports Server (NTRS)

    Olczak, Eugene G (Inventor)

    2011-01-01

    An objective lens includes multiple optical elements disposed between a first end and a second end, each optical element oriented along an optical axis. Each optical surface of the multiple optical elements provides an angle of incidence to a marginal ray that is above a minimum threshold angle. This threshold angle minimizes pupil ghosts that may enter an interferometer. The objective lens also optimizes wavefront delivery and pupil imaging onto an optical surface under test.

  15. Objective Lens Optimized for Wavefront Delivery, Pupil Imaging, and Pupil Ghosting

    NASA Technical Reports Server (NTRS)

    Olzcak, Gene

    2009-01-01

    An interferometer objective lens (or diverger) may be used to transform a collimated beam into a diverging or converging beam. This innovation provides an objective lens that has diffraction-limited optical performance that is optimized at two sets of conjugates: imaging to the objective focus and imaging to the pupil. The lens thus provides for simultaneous delivery of a high-quality beam and excellent pupil resolution properties.

  16. Suggestions for Teaching the Migratory Pupil.

    ERIC Educational Resources Information Center

    Blanton, Dolly; And Others

    Suggestions for teachers of migrant children are offered in seven individual teaching guides which were developed as part of a research and curriculum development project to improve the teaching of migratory pupils. Levels of study include grades four, five, six, and seven, and one general unit deals with providing an effective learning…

  17. Pupil Personnel Services: Material Review List Recommendations.

    ERIC Educational Resources Information Center

    Cardinale, Anthony

    This list of materials provides recommendations to counselors and guidance personnel for the purchase of materials for pupil personnel services programs in the Department of Defense Dependents Schools (DDDS). The listing, based on staff reviews in each of the six DDDS regions, is divided into 10 content areas: (1) assessment and evaluation; (2)…

  18. How Finland Serves Gifted and Talented Pupils

    ERIC Educational Resources Information Center

    Tirri, Kirsi; Kuusisto, Elina

    2013-01-01

    The purpose of this article is to provide an overview of the ways gifted and talented pupils are served in Finland. The trend toward individualism and freedom of choice as well as national policy affecting gifted education are discussed. Empirical research on Finnish teachers' attitudes toward gifted education with respect to the national…

  19. Curricular Content for Pupils' Mental Health

    ERIC Educational Resources Information Center

    Ebadi, Seyed Hossein; Keshtiaray, Narges; Aghaei, Asghar; Yousefy, Alireza

    2016-01-01

    Present-day curricular designs have to take the pupils' psychological needs in account, thus becoming melodies of mental health and happiness for the next generation. Emphasizing the findings from previous investigations using the research synthesis methodology, the present study has been conducted aiming at achieving some integrative knowledge…

  20. North Yorkshire Schools' Responses to Pupil Bereavement

    ERIC Educational Resources Information Center

    Holland, John; McLennan, Derek

    2015-01-01

    This was a research project carried out in North Yorkshire schools by the loss and bereavement research group of the Educational Psychology Service. The background was an interest in how schools responded to bereaved pupils, whether they had a structured response, trained staff and training needs, from where they sought support and the level of…

  1. Pupil Masks for Spectrophotometry of Transiting Exoplanets

    NASA Astrophysics Data System (ADS)

    Itoh, Satoshi; Matsuo, Taro; Goda, Shohei; Shibai, Hiroshi; Sumi, Takahiro

    2017-09-01

    Spectrophotometric stability, which is crucial in the spectral characterization of transiting exoplanets, is affected by photometric variations arising from field-stop loss in space telescopes with pointing jitter or primary mirror deformation. This paper focuses on a new method for removing slit-loss or field-stop-loss photometric variation through the use of a pupil mask. Two types of pupil function are introduced: the first uses conventional (e.g., Gaussian or hyper-Gaussian) apodizing patterns; whereas the second, which we call a block-shaped mask, employs a new type of pupil mask designed for high photometric stability. A methodology for the optimization of a pupil mask for transit observations is also developed. The block-shaped mask can achieve a photometric stability of 10-5 for a nearly arbitrary field-stop radius when the pointing jitter is smaller than approximately 0.7λ /D and a photometric stability of 10-6 at a pointing jitter smaller than approximately 0.5λ /D. The impact of optical aberrations and mask imperfections upon mask performance is also discussed.

  2. Microcomputer Support of Teacher-Pupil Dialogue.

    ERIC Educational Resources Information Center

    Strang, Harold S.; Loper, Ann Booker

    1986-01-01

    Describes features of a second generation computer simulation offering teacher education students realistic experience in maintaining verbal dialog during spelling lessons with computer-defined pupils. Features discussed include lesson content, behavioral sensitivity, cueing during training, and post-lesson debriefing. User evaluations of the…

  3. Parents of Excluded Pupils: Customers, Partners, Problems?

    ERIC Educational Resources Information Center

    Macleod, Gale; Pirrie, Anne; McCluskey, Gillean; Cullen, MairiAnn

    2013-01-01

    This article presents data drawn from interviews with a range of service providers and with the parents of pupils permanently excluded from alternative provision in England. The findings are considered in the context of recent policy developments in the area of children and families. These include the neo-liberal framing of parents as customers…

  4. Manual for School Administrators on Pupil Transportation.

    ERIC Educational Resources Information Center

    Tennessee State Dept. of Education, Nashville.

    Guiding principles, state laws, and state board rules and regulations are covered, providing school administrators with a ready reference in the field of pupil transportation. Divided into three sections, the manual initially covers administrative procedures including--(1) the purchase of buses, (2) bus maintenance, (3) employment of drivers, (4)…

  5. North Yorkshire Schools' Responses to Pupil Bereavement

    ERIC Educational Resources Information Center

    Holland, John; McLennan, Derek

    2015-01-01

    This was a research project carried out in North Yorkshire schools by the loss and bereavement research group of the Educational Psychology Service. The background was an interest in how schools responded to bereaved pupils, whether they had a structured response, trained staff and training needs, from where they sought support and the level of…

  6. Educational Potential of Northern Canadian Native Pupils.

    ERIC Educational Resources Information Center

    MacArthur, R.S.

    Evidence presented in this paper indicates the existence of both general intellectual potential and differential abilities of Eskimo and Indian-Metis pupils in contrast to White classmates. A factor analytic technique is described which was used to treat data obtained from a sample of more than 1,800 students. One conclusion of the study is that a…

  7. Non-Verbal Communication in Retarded Pupils.

    ERIC Educational Resources Information Center

    Powell, Evan R.; Dennis, Virginia Collier

    Thirty educable mentally retarded (EMR) and 20 trainable mentally retarded (TMR) black or white pupils were observed interacting with classmates and 25 teachers in a retardation center. Multi-modal communicative behavior was noted, with focus on interpersonal spatial distance as one index of relationship and affect between interacting partners.…

  8. Teachers' and Pupils' Definitions of Bullying

    ERIC Educational Resources Information Center

    Naylor, Paul; Cowie, Helen; Cossin, Fabienne; de Bettencourt, Rita; Lemme, Francesca

    2006-01-01

    Background: Comparison of teachers' and pupils' definitions of bullying is important for considering the implications for reports of its incidence in schools, for the study of developmental trends in children's and adolescents' perceptions of the phenomenon and for evaluating the effectiveness of interventions designed to combat bullying. Aims: To…

  9. Innovative Solutions to Challenges in Pupil Transportation.

    ERIC Educational Resources Information Center

    Ross, Jonathan; Burkybile, Sharon

    2000-01-01

    States have had to budget increasing amounts for mandated pupil-transportation services as their state transportation aid has been slashed dramatically. Among school districts, cooperation and coordination through shared services (consortia) have resulted in safer, more reliable, and more efficient transportation. Implementation advice is…

  10. Photonic technologies for a pupil remapping interferometer

    NASA Astrophysics Data System (ADS)

    Tuthill, Peter; Jovanovic, Nemanja; Lacour, Sylvestre; Lehmann, Andrew; Ams, Martin; Marshall, Graham; Lawrence, Jon; Withford, Michael; Robertson, Gordon; Ireland, Michael; Pope, Benjamin; Stewart, Paul

    2010-07-01

    Interest in pupil-remapping interferometry, in which a single telescope pupil is fragmented and recombined using fiber optic technologies, has been growing among a number of groups. As a logical extrapolation from several highly successful aperture masking programs underway worldwide, pupil remapping offers the advantage of spatial filtering (with single-mode fibers) and in principle can avoid the penalty of low throughput inherent to an aperture mask. However in practice, pupil remapping presents a number of difficult technological challenges including injection into the fibers, pathlength matching of the device, and stability and reproducibility of the results. Here we present new approaches based on recently-available photonic technologies in which coherent threedimensional waveguide structures can be sculpted into bulk substrate. These advances allow us to miniaturize the photonic processing into a single, robust, thermally stable element; ideal for demanding observatory or spacecraft environments. Ultimately, a wide range of optical functionality could be routinely fabricated into such structures, including beam combiners and dispersive or wavelength selective elements, bringing us closer to the vision of an interferometer on a chip.

  11. Secondary School Pupils Perceptions of Physics

    ERIC Educational Resources Information Center

    Barmby, Patrick; Defty, Neil

    2006-01-01

    This paper describes the analysis of data collected by Durham University's YELLIS project, over the period of 1999 to 2004. Included in this data was the degree to which pupils in England at the end of their secondary education "liked" or "disliked" different subjects, and their expected examination grades in these subjects.…

  12. Psychometric Aspects of Pupil Monitoring Systems

    ERIC Educational Resources Information Center

    Glas, Cees A. W.; Geerlings, Hanneke

    2009-01-01

    Pupil monitoring systems support the teacher in tailoring teaching to the individual level of a student and in comparing the progress and results of teaching with national standards. The systems are based on the availability of an item bank calibrated using item response theory. The assessment of the students' progress and results can be further…

  13. Diagnostics of Pupils' Attitude to Education

    ERIC Educational Resources Information Center

    Eminli, Tovuz

    2011-01-01

    The paper is devoted to the investigation of the questions connected with the pedagogical diagnostics, in particular, the diagnostics of pupils' attitude to education. It is considered reasonable to apply the practice of development of an individual pedagogical and psychological map for productive implementation of the pedagogical diagnostics and…

  14. Pupils' Difficulties: What Can the Teacher Do?

    ERIC Educational Resources Information Center

    Dawson, C. J.

    1978-01-01

    Discusses how the teacher can deal with difficulties pupils of varying ages have in understanding certain chemical ideas. The article does not support using a Piagetian model for science courses in secondary schools. It suggests that Ausubel's learning theory is of much more use to the practicing teacher. (HM)

  15. Shared Reading, the Pupil, and the Teacher

    ERIC Educational Resources Information Center

    Ediger, Marlow

    2011-01-01

    Pupil/teacher interaction provides opportunities for many kinds of learning experiences. Within the reading curriculum, there are a plethora of activities in oral communication and working together harmoniously. Thus from every day experiences, the teacher may communicate verbally what he/she has read in an interesting, informative manner on the…

  16. The Pupils Voice in Different Educational Settings

    ERIC Educational Resources Information Center

    Herz, Birgit; Haertel, Nora

    2016-01-01

    Since ratification of the UN Convention on the Rights of Persons with Disabilities in 2009, joint "same goal" and "different goal" education of pupils with and without disabilities has become a key concern of any changes in German educational policy. The lively public discourse and the controversial debate among experts have…

  17. Negative Home Influence and Pupil School Success.

    ERIC Educational Resources Information Center

    Soar, Robert S.; Soar, Ruth M.

    The study was devised to examine the empirical relations between selected home influences and a number of aspects of pupil growth in school, both academic and personal-social. Data was compiled on 559 children, in grades 3 through 6, from a metropolitan area in South Carolina. Data from a concurrent project noted that these were atypical…

  18. The Pupils Voice in Different Educational Settings

    ERIC Educational Resources Information Center

    Herz, Birgit; Haertel, Nora

    2016-01-01

    Since ratification of the UN Convention on the Rights of Persons with Disabilities in 2009, joint "same goal" and "different goal" education of pupils with and without disabilities has become a key concern of any changes in German educational policy. The lively public discourse and the controversial debate among experts have…

  19. Class Composition Influences on Pupils' Cognitive Development

    ERIC Educational Resources Information Center

    Peetsma, Thea; van der Veen, Ineke; Koopman, Pjotr; van Schooten, Erik

    2006-01-01

    The proportion of low-achieving children in a class can affect the progress of individual pupils in that class. Having a large proportion of low achievers in a class could slow down growth in cognitive achievement but, might also boost such growth, due to the effects of specialist teaching geared to low achievers' needs. In a longitudinal study of…

  20. Creativity and Pupils' Experience of School

    ERIC Educational Resources Information Center

    Cullingford, Cedric

    2007-01-01

    Based on the analysis of interviews with children, this article links what we know about the way in which they learn with their views of creativity. Whilst pupils have a crisp view of the nature of creativity, which links them to well-established philosophical views, this contrasts both with the vaguer notions of the term and with their experience…

  1. Parents of Excluded Pupils: Customers, Partners, Problems?

    ERIC Educational Resources Information Center

    Macleod, Gale; Pirrie, Anne; McCluskey, Gillean; Cullen, MairiAnn

    2013-01-01

    This article presents data drawn from interviews with a range of service providers and with the parents of pupils permanently excluded from alternative provision in England. The findings are considered in the context of recent policy developments in the area of children and families. These include the neo-liberal framing of parents as customers…

  2. Environmental Education and Pupils' Conceptions of Matter.

    ERIC Educational Resources Information Center

    Hellden, Gustav

    1995-01-01

    Reports on a seven-year longitudinal study of pupils' (n=25) understanding of ecological processes with emphasis on how their conceptions of matter influence their understanding. Results indicate that initially students expected the plants cultivated in closed transparent boxes to die but later used a "cycle model" to explain how the…

  3. Innovative Solutions to Challenges in Pupil Transportation.

    ERIC Educational Resources Information Center

    Ross, Jonathan; Burkybile, Sharon

    2000-01-01

    States have had to budget increasing amounts for mandated pupil-transportation services as their state transportation aid has been slashed dramatically. Among school districts, cooperation and coordination through shared services (consortia) have resulted in safer, more reliable, and more efficient transportation. Implementation advice is…

  4. Pupil Dilation and Object Permanence in Infants

    ERIC Educational Resources Information Center

    Sirois, Sylvain; Jackson, Iain R.

    2012-01-01

    This paper examines the relative merits of looking time and pupil diameter measures in the study of early cognitive abilities of infants. Ten-month-old infants took part in a modified version of the classic drawbridge experiment used to study object permanence (Baillargeon, Spelke, & Wasserman, 1985). The study involved a factorial design where…

  5. Consulting Secondary School Pupils about Their Learning

    ERIC Educational Resources Information Center

    Thompson, Paul

    2009-01-01

    This paper reports on the findings of a research project which explored the value for secondary school teachers of consulting with pupils about the curriculum. Twenty volunteer teachers across a range of subject areas in an 11-18 and three 11-16 secondary schools in a city in the East Midlands of England were given an open-ended remit to…

  6. Exploring Pupils' Beliefs about Designers and Designing

    ERIC Educational Resources Information Center

    Trebell, Donna

    2011-01-01

    The purpose of this paper is to report on an investigation into pupil beliefs about designers and designing conducted as part of a research project focusing on Designerly Activity in Secondary Design and Technology which builds upon a pilot study (Barlex and Trebell in "Int J Technol Design Educ," 2007). Four research questions drove this element…

  7. Motivating Pupils To Learn in Mathematics.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    The mathematics teacher has a major responsibility in assisting pupils to learn in ongoing lessons and units of study. This paper discusses ways of motivating students in the mathematics classroom from the perspectives of different learning theories such as behaviorism, humanism, cognitive psychology, and constructivism. Guidelines for teaching…

  8. Pupils' Difficulties: What Can the Teacher Do?

    ERIC Educational Resources Information Center

    Dawson, C. J.

    1978-01-01

    Discusses how the teacher can deal with difficulties pupils of varying ages have in understanding certain chemical ideas. The article does not support using a Piagetian model for science courses in secondary schools. It suggests that Ausubel's learning theory is of much more use to the practicing teacher. (HM)

  9. Teachers' and Pupils' Definitions of Bullying

    ERIC Educational Resources Information Center

    Naylor, Paul; Cowie, Helen; Cossin, Fabienne; de Bettencourt, Rita; Lemme, Francesca

    2006-01-01

    Background: Comparison of teachers' and pupils' definitions of bullying is important for considering the implications for reports of its incidence in schools, for the study of developmental trends in children's and adolescents' perceptions of the phenomenon and for evaluating the effectiveness of interventions designed to combat bullying. Aims: To…

  10. Developing Pupils' Performance in Team Invasion Games

    ERIC Educational Resources Information Center

    Gray, Shirley; Sproule, John

    2011-01-01

    Background: To develop pupils' team invasion games (TIG) performance within physical education (PE), practitioners have traditionally adopted teacher-centred, skill-focused approaches. Teaching Games for Understanding and the Tactical approach are alternative approaches to TIG teaching that aim to develop overall game performance, including…

  11. Citizenship: Pupil Involvement in Scottish Schools

    ERIC Educational Resources Information Center

    Mills, Iain

    2004-01-01

    "Citizenship" is currently an area receiving considerable attention in schools. It has been argued that citizenship is best learned through experiencing democratic decision-making rather than through learning about it in the classroom. The article examines the background to moves towards greater pupil involvement in decision-making in…

  12. Pupil responses to intravenous heroin (diamorphine) in dependent and non-dependent humans.

    PubMed

    Tress, K H; El-Sobky, A A

    1979-02-01

    1. Intravenous heroin was administered to volunteers, in doses of 2.5 and 5 mg to non-dependent subjects and does of 1/6, 1/3 and 1/2 of their prescribed daily does of opiates to dependent subjects, and pupillary responses measured before and three times during the 2 h after injection. 2. Tolerance to the miotic effects of heroin in the dependent subjects was demonstrated--larger doses of heroin were needed to produce the same pupil response in dependent subjects than in non-dependent subjects and the duration of action was shorter in the former group. 3. The effect of concurrent oral methadone medication on pupil response to heroin was demonstrated. Subjects prescribed both methadone and heroin showed smaller control pupil diameters and a reduced dose effect to heroin than did subjects prescribed heroin alone.

  13. Pupil responses to intravenous heroin (diamorphine) in dependent and non-dependent humans.

    PubMed Central

    Tress, K H; El-Sobky, A A

    1979-01-01

    1. Intravenous heroin was administered to volunteers, in doses of 2.5 and 5 mg to non-dependent subjects and does of 1/6, 1/3 and 1/2 of their prescribed daily does of opiates to dependent subjects, and pupillary responses measured before and three times during the 2 h after injection. 2. Tolerance to the miotic effects of heroin in the dependent subjects was demonstrated--larger doses of heroin were needed to produce the same pupil response in dependent subjects than in non-dependent subjects and the duration of action was shorter in the former group. 3. The effect of concurrent oral methadone medication on pupil response to heroin was demonstrated. Subjects prescribed both methadone and heroin showed smaller control pupil diameters and a reduced dose effect to heroin than did subjects prescribed heroin alone. PMID:760755

  14. Low number of luminance levels in the luminance noise increases color discrimination thresholds estimated with pseudoisochromatic stimuli.

    PubMed

    Souza, Givago S; Malone, Felecia L; Crawford, Teera L; Miquilini, Letícia; Salomão, Raílson C; Guimarães, Diego L; Ventura, Dora F; Fitzgerald, Malinda E C; Silveira, Luiz Carlos L

    2014-01-01

    In pseudoisochromatic stimuli the presence of spatial and luminance noise forces the subject to discriminate the target from the background solely on the basis of chromaticity difference. Color-blind subjects may show difficulty to identify the target due to the elimination of borders and brightness clues caused by the luminance and spatial noise. Few studies have fully described the features of pseudoisochromatic stimuli. Fewer investigators have focused their studies in the effects of specific pseudoisochromatic parameters on color discrimination. We used the Cambridge Color Test (CCT) to investigate the influence on color discrimination thresholds due to the number of luminance levels present in the luminance noise. The CCT default has six luminance steps; however, in our investigation a total of eight different conditions were tested from 2 to 16 luminance steps. It was found that the CCT provided very robust values for color discrimination thresholds, which were degraded only for very small number of luminance steps. When the number of steps was increased, the color discrimination thresholds improved from 2 to 6 luminance steps and gradually reached a plateau for 10 or more luminance steps. The area of color discrimination ellipses as a function of luminance steps matches the relative proportion of ineffective contrasts between mosaic patches as a function of luminance steps, assuming that contrast becomes ineffective for values 18.6% or less. The lower number of color and luminance interactions in these conditions could explain the measured increase of color discrimination thresholds. The primary conclusion from this investigation was that results from pseudoisochromatic tests should have their parameters described in more detail. This type of description would allow a better understanding of the results provided, interpretations, and therefore cross study comparison of results obtained from different laboratories.

  15. Low number of luminance levels in the luminance noise increases color discrimination thresholds estimated with pseudoisochromatic stimuli

    PubMed Central

    Souza, Givago S.; Malone, Felecia L.; Crawford, Teera L.; Miquilini, Letícia; Salomão, Raílson C.; Guimarães, Diego L.; Ventura, Dora F.; Fitzgerald, Malinda E. C.; Silveira, Luiz Carlos L.

    2014-01-01

    In pseudoisochromatic stimuli the presence of spatial and luminance noise forces the subject to discriminate the target from the background solely on the basis of chromaticity difference. Color-blind subjects may show difficulty to identify the target due to the elimination of borders and brightness clues caused by the luminance and spatial noise. Few studies have fully described the features of pseudoisochromatic stimuli. Fewer investigators have focused their studies in the effects of specific pseudoisochromatic parameters on color discrimination. We used the Cambridge Color Test (CCT) to investigate the influence on color discrimination thresholds due to the number of luminance levels present in the luminance noise. The CCT default has six luminance steps; however, in our investigation a total of eight different conditions were tested from 2 to 16 luminance steps. It was found that the CCT provided very robust values for color discrimination thresholds, which were degraded only for very small number of luminance steps. When the number of steps was increased, the color discrimination thresholds improved from 2 to 6 luminance steps and gradually reached a plateau for 10 or more luminance steps. The area of color discrimination ellipses as a function of luminance steps matches the relative proportion of ineffective contrasts between mosaic patches as a function of luminance steps, assuming that contrast becomes ineffective for values 18.6% or less. The lower number of color and luminance interactions in these conditions could explain the measured increase of color discrimination thresholds. The primary conclusion from this investigation was that results from pseudoisochromatic tests should have their parameters described in more detail. This type of description would allow a better understanding of the results provided, interpretations, and therefore cross study comparison of results obtained from different laboratories. PMID:25566106

  16. Pupil movements to light and accommodative stimulation - A comparative study.

    NASA Technical Reports Server (NTRS)

    Semmlow, J.; Stark, L.

    1973-01-01

    Isolation and definition of specific response components in pupil reflexes through comparison of the dynamic features of light-induced and accommodation-induced pupil movements. A quantitative analysis of the behavior of the complex nonlinear pupil responses reveals the presence of two independent nonlinear characteristics: a range-dependent gain and a direction dependence or movement asymmetry. These nonlinear properties are attributed to motor processes because they are observable in pupil responses to both light and accommodation stimuli. The possible mechanisms and consequences of these pupil response characteristics are quantitatively defined and discussed.

  17. Pupil movements to light and accommodative stimulation - A comparative study.

    NASA Technical Reports Server (NTRS)

    Semmlow, J.; Stark, L.

    1973-01-01

    Isolation and definition of specific response components in pupil reflexes through comparison of the dynamic features of light-induced and accommodation-induced pupil movements. A quantitative analysis of the behavior of the complex nonlinear pupil responses reveals the presence of two independent nonlinear characteristics: a range-dependent gain and a direction dependence or movement asymmetry. These nonlinear properties are attributed to motor processes because they are observable in pupil responses to both light and accommodation stimuli. The possible mechanisms and consequences of these pupil response characteristics are quantitatively defined and discussed.

  18. Hybrid super-resolving pupils with smooth profile

    NASA Astrophysics Data System (ADS)

    Alcalá Ochoa, Noé; Landgrave, J. E. A.; Hermosillo, Y.; García-Márquez, J.; González-Vega, A.

    2011-08-01

    One form of achieving super-resolution consists in reducing the size of the Point Spread Function (PSF) of a diffraction-limited optical system. For this end, good results have been obtained by means of pupils with discontinuous profiles. When devices such as deformable mirrors are used to generate such pupils, however, these cannot be accurately reproduced. To overcome this limitation, we developed a method based on a Bessel series expansion to design pupils with smooth profiles, and found that, properly designed, pupils with continuous profiles will perform equally well, and in some respects better, than pupils with discontinuous ones.

  19. The Manchester Color Wheel: validation in secondary school pupils

    PubMed Central

    2012-01-01

    Background As part of our research programme into facilitating improved ways of communicating with patients, especially about more sensitive clinical issues, we have been investigating whether there are any non-verbal methods that might aid this process. One such approach is to ask patients to choose a color in response to a particular question, for instance about health or psychological status, and for this purpose we developed the Manchester Color Wheel (MCW). This instrument consists of positive, neutral and negative colors and its validation in normal adults and those with anxiety or depression showed that it is responsive to change and reproducible. It also has the capacity to identify a positive frame of mind. We concluded that it might be a particularly useful instrument in adolescents and therefore this study aimed to validate it in a secondary school. Methods 620 pupils (aged 11–17 years, mean age 14.0 years, 298 (48.1%) males, 322 (51.9%) females) at Sale Grammar School in Greater Manchester were asked to relate their mood to a MCW color and also complete the Hospital Anxiety Depression (HAD) questionnaire. To give these pupils an experience in science, 197 were divided into four subgroups for an ‘experiment’ to ascertain whether, compared to controls, a change in mood color choice could be induced by participation in sport, music or art activities. Results Although mood color and HAD depression score are unlikely to be measuring exactly the same psychological state, a negative mood color was chosen by 62.5% of HAD depressed compared to only 14.5% of HAD normal pupils (p < 0.001). In contrast, a positive mood color was chosen by 48.9% of normal and only 18.8% of depressed pupils (p < 0.001). In the ‘experiment’, compared to controls, all activities resulted in an increased choice of positive mood colors which reached significance for sport and music. Conclusion This study confirms the potential utility of the MCW to rapidly and

  20. The Manchester Color Wheel: validation in secondary school pupils.

    PubMed

    Carruthers, Helen R; Magee, Linda; Osborne, Susan; Hall, Linda K; Whorwell, Peter J

    2012-09-05

    As part of our research programme into facilitating improved ways of communicating with patients, especially about more sensitive clinical issues, we have been investigating whether there are any non-verbal methods that might aid this process. One such approach is to ask patients to choose a color in response to a particular question, for instance about health or psychological status, and for this purpose we developed the Manchester Color Wheel (MCW). This instrument consists of positive, neutral and negative colors and its validation in normal adults and those with anxiety or depression showed that it is responsive to change and reproducible. It also has the capacity to identify a positive frame of mind. We concluded that it might be a particularly useful instrument in adolescents and therefore this study aimed to validate it in a secondary school. 620 pupils (aged 11-17 years, mean age 14.0 years, 298 (48.1%) males, 322 (51.9%) females) at Sale Grammar School in Greater Manchester were asked to relate their mood to a MCW color and also complete the Hospital Anxiety Depression (HAD) questionnaire. To give these pupils an experience in science, 197 were divided into four subgroups for an 'experiment' to ascertain whether, compared to controls, a change in mood color choice could be induced by participation in sport, music or art activities. Although mood color and HAD depression score are unlikely to be measuring exactly the same psychological state, a negative mood color was chosen by 62.5% of HAD depressed compared to only 14.5% of HAD normal pupils (p < 0.001). In contrast, a positive mood color was chosen by 48.9% of normal and only 18.8% of depressed pupils (p < 0.001). In the 'experiment', compared to controls, all activities resulted in an increased choice of positive mood colors which reached significance for sport and music. This study confirms the potential utility of the MCW to rapidly and easily assess a variety of health issues in large populations