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Sample records for selected visual environmental

  1. Conditional control in visual selection

    NARCIS (Netherlands)

    van Zoest, Wieske; Van der Stigchel, Stefan; Donk, Mieke

    2017-01-01

    Attention and eye movements provide a window into the selective processing of visual information. Evidence suggests that selection is influenced by various factors and is not always under the strategic control of the observer. The aims of this tutorial review are to give a brief introduction to eye

  2. Case Studies of Environmental Visualization

    Directory of Open Access Journals (Sweden)

    Panagiotis Patlakas

    2017-09-01

    Full Text Available The performance gap between simulation and reality has been identified as a major challenge to achieving sustainability in the Built Environment. While Post-Occupancy Evaluation (POE surveys are an integral part of better understanding building performance, and thus addressing this issue, the importance of POE remains relatively unacknowledged within the wider Built Environment community. A possible reason that has been highlighted is that POE survey data is not easily understood and utilizable by non-expert stakeholders, including designers. A potential method by which to address this is the visualization method, which has well established benefits for communication of big datasets. This paper presents two case studies where EnViz (short for “Environmental Visualization”, a prototype software application developed for research purposes, was utilized and its effectiveness tested via a range of analysis tasks. The results are discussed and compared with those of previous work that utilized variations of the methods presented here. The paper concludes by presenting the lessons drawn from the five-year period of EnViz, emphasizing the potential of environmental visualization for decision support in environmental design and engineering for the built environment, and suggests directions for future development.

  3. Visualizing data for environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.

    1997-04-01

    The Environmental Restoration Project at Los Alamos National Laboratory (LANL) has over 11,000 sampling locations in a 44 square mile area. The sample analyses contain raw analytical chemistry values for over 2,300 analytes and compounds used to define and remediate contaminated areas at LANL. The data consist of 2.5 million records in an oracle database. Maps are often used to visualize the data. Problems arise when a client specifies a particular kind of map without fully understanding the limitations of the data or the map. The ability of maps to convey information is dependent on many factors, though all maps are data dependent. The quantity, spatial distribution, and numerical range of the data can limit use with certain kinds of maps. To address these issues and educate the clients, several types of statistical maps (e.g., choropleth, isarithm, and graduated symbol such as bubble and spike) used for environmental analysis were chosen to show the advantages, disadvantages, and data limitations of each. By examining both the complexity of the analytical data and the limitations of the map type, it is possible to consider how reality has been transformed through the map, and if that transformation accurately conveys the information present.

  4. Visualizing data for environmental analysis

    International Nuclear Information System (INIS)

    Benson, J.

    1997-01-01

    The Environmental Restoration Project at Los Alamos National Laboratory (LANL) has over 11,000 sampling locations in a 44 square mile area. The sample analyses contain raw analytical chemistry values for over 2,300 analytes and compounds used to define and remediate contaminated areas at LANL. The data consist of 2.5 million records in an oracle database. Maps are often used to visualize the data. Problems arise when a client specifies a particular kind of map without fully understanding the limitations of the data or the map. The ability of maps to convey information is dependent on many factors, though all maps are data dependent. The quantity, spatial distribution, and numerical range of the data can limit use with certain kinds of maps. To address these issues and educate the clients, several types of statistical maps (e.g., choropleth, isarithm, and graduated symbol such as bubble and spike) used for environmental analysis were chosen to show the advantages, disadvantages, and data limitations of each. By examining both the complexity of the analytical data and the limitations of the map type, it is possible to consider how reality has been transformed through the map, and if that transformation accurately conveys the information present

  5. Neural Mechanisms of Selective Visual Attention.

    Science.gov (United States)

    Moore, Tirin; Zirnsak, Marc

    2017-01-03

    Selective visual attention describes the tendency of visual processing to be confined largely to stimuli that are relevant to behavior. It is among the most fundamental of cognitive functions, particularly in humans and other primates for whom vision is the dominant sense. We review recent progress in identifying the neural mechanisms of selective visual attention. We discuss evidence from studies of different varieties of selective attention and examine how these varieties alter the processing of stimuli by neurons within the visual system, current knowledge of their causal basis, and methods for assessing attentional dysfunctions. In addition, we identify some key questions that remain in identifying the neural mechanisms that give rise to the selective processing of visual information.

  6. Location selection in the visual domain

    NARCIS (Netherlands)

    van der Lubbe, Robert Henricus Johannes; Woestenburg, Jaap C.

    2000-01-01

    According to A.H.C. Van der Heijden (1992), attentional selection of visual stimuli can be considered as location selection. Depending on the type of task, location selection can be considered to be automatic )e.g., in case of abrupt onsets), directly controlled (e.g., in case of symbolic precues),

  7. Feature and Region Selection for Visual Learning.

    Science.gov (United States)

    Zhao, Ji; Wang, Liantao; Cabral, Ricardo; De la Torre, Fernando

    2016-03-01

    Visual learning problems, such as object classification and action recognition, are typically approached using extensions of the popular bag-of-words (BoWs) model. Despite its great success, it is unclear what visual features the BoW model is learning. Which regions in the image or video are used to discriminate among classes? Which are the most discriminative visual words? Answering these questions is fundamental for understanding existing BoW models and inspiring better models for visual recognition. To answer these questions, this paper presents a method for feature selection and region selection in the visual BoW model. This allows for an intermediate visualization of the features and regions that are important for visual learning. The main idea is to assign latent weights to the features or regions, and jointly optimize these latent variables with the parameters of a classifier (e.g., support vector machine). There are four main benefits of our approach: 1) our approach accommodates non-linear additive kernels, such as the popular χ(2) and intersection kernel; 2) our approach is able to handle both regions in images and spatio-temporal regions in videos in a unified way; 3) the feature selection problem is convex, and both problems can be solved using a scalable reduced gradient method; and 4) we point out strong connections with multiple kernel learning and multiple instance learning approaches. Experimental results in the PASCAL VOC 2007, MSR Action Dataset II and YouTube illustrate the benefits of our approach.

  8. Environmental Pollution, A Selective Bibliography.

    Science.gov (United States)

    Clearinghouse for Federal Scientific and Technical Information, Springfield, VA.

    This bibliography on environmental pollution is comprised primarily of reports of federally sponsored research by such departments and agencies as HEW, Interior, AEC, NASA, Defense, Transportation, and others. The reports were selected from Clearinghouse announcement journals during the period 1968 through April 1970. The bibliography contains…

  9. Prefrontal contributions to visual selective attention.

    Science.gov (United States)

    Squire, Ryan F; Noudoost, Behrad; Schafer, Robert J; Moore, Tirin

    2013-07-08

    The faculty of attention endows us with the capacity to process important sensory information selectively while disregarding information that is potentially distracting. Much of our understanding of the neural circuitry underlying this fundamental cognitive function comes from neurophysiological studies within the visual modality. Past evidence suggests that a principal function of the prefrontal cortex (PFC) is selective attention and that this function involves the modulation of sensory signals within posterior cortices. In this review, we discuss recent progress in identifying the specific prefrontal circuits controlling visual attention and its neural correlates within the primate visual system. In addition, we examine the persisting challenge of precisely defining how behavior should be affected when attentional function is lost.

  10. Selection-for-action in visual search

    NARCIS (Netherlands)

    Hannus, A; Cornelissen, FW; Lindemann, O; Bekkering, H

    2005-01-01

    Grasping an object rather than pointing to it enhances processing of its orientation but not its color. Apparently, visual discrimination is selectively enhanced for a behaviorally relevant feature. In two experiments we investigated the limitations and targets of this bias. Specifically, in

  11. Gender and environmental influences on visual acuity in Owerri ...

    African Journals Online (AJOL)

    This study assessed the gender and environmental influences on visual function among adults in Owerri, Nigeria. Visual acuity (V.A.) is a measure of visual function in health and disease. Visual disability together with other disabling conditions is a barrier to development, yet there is little known about the visual acuity and ...

  12. Selection-for-action in visual search.

    Science.gov (United States)

    Hannus, Aave; Cornelissen, Frans W; Lindemann, Oliver; Bekkering, Harold

    2005-01-01

    Grasping an object rather than pointing to it enhances processing of its orientation but not its color. Apparently, visual discrimination is selectively enhanced for a behaviorally relevant feature. In two experiments we investigated the limitations and targets of this bias. Specifically, in Experiment 1 we were interested to find out whether the effect is capacity demanding, therefore we manipulated the set-size of the display. The results indicated a clear cognitive processing capacity requirement, i.e. the magnitude of the effect decreased for a larger set size. Consequently, in Experiment 2, we investigated if the enhancement effect occurs only at the level of behaviorally relevant feature or at a level common to different features. Therefore we manipulated the discriminability of the behaviorally neutral feature (color). Again, results showed that this manipulation influenced the action enhancement of the behaviorally relevant feature. Particularly, the effect of the color manipulation on the action enhancement suggests that the action effect is more likely to bias the competition between different visual features rather than to enhance the processing of the relevant feature. We offer a theoretical account that integrates the action-intention effect within the biased competition model of visual selective attention.

  13. Eco-Visualization: Promoting Environmental Stewardship in the Museum

    Science.gov (United States)

    Holmes, Tiffany

    2007-01-01

    Eco-visualizations are artworks that reinterpret environmental data with custom software to promote stewardship. Eco-visualization technology offers a new way to dynamically picture environmental data and make it meaningful to a museum population. The questions are: How might museums create new projects and programs around place-based information?…

  14. Toward a New Theory for Selecting Instructional Visuals.

    Science.gov (United States)

    Croft, Richard S.; Burton, John K.

    This paper provides a rationale for the selection of illustrations and visual aids for the classroom. The theories that describe the processing of visuals are dual coding theory and cue summation theory. Concept attainment theory offers a basis for selecting which cues are relevant for any learning task which includes a component of identification…

  15. Declarative and Scalable Selection for Map Visualizations

    DEFF Research Database (Denmark)

    Kefaloukos, Pimin Konstantin Balic

    and is itself a source and cause of prolific data creation. This calls for scalable map processing techniques that can handle the data volume and which play well with the predominant data models on the Web. (4) Maps are now consumed around the clock by a global audience. While historical maps were singleuser......-defined constraints as well as custom objectives. The purpose of the language is to derive a target multi-scale database from a source database according to holistic specifications. (b) The Glossy SQL compiler allows Glossy SQL to be scalably executed in a spatial analytics system, such as a spatial relational......, there are indications that the method is scalable for databases that contain millions of records, especially if the target language of the compiler is substituted by a cluster-ready variant of SQL. While several realistic use cases for maps have been implemented in CVL, additional non-geographic data visualization uses...

  16. ATTENTIONAL NETWORKS AND SELECTIVE VISUAL SYSTEM

    Directory of Open Access Journals (Sweden)

    ALEJANDRO CASTILLO MORENO

    2006-05-01

    Full Text Available In this paper we checked the principal researches and theories to explain the attention system functioning.We are going to start reviewing along time about the concept of attention, from filter theories andresources distributor theories, to the current theories in which attention is conceived as a control system.From this last point of view, we will emphasize on the attentional networks theory of Posner, thatproposes different systems to explain diverse aspects of attention, but they are related to each other. Atlast in this paper, we will mention experimental results that have been important to characterize theselective attentional mechanisms of the human visual system, using the attentional spotlight model forthis aim.

  17. Selecting environmental indicator for use in strategic environmental assessment

    International Nuclear Information System (INIS)

    Donnelly, Alison; Jones, Mike; O'Mahony, Tadhg; Byrne, Gerry

    2007-01-01

    The primary aim of carrying out Strategic Environmental Assessment (SEA) is to provide for a high level of environmental protection and to integrate environmental considerations into the planning process. The SEA Directive (2001/42/EC) recommends monitoring to determine the environmental impact of the implementation of plans and programmes. Environmental indicators are a useful tool by which this impact may be measured. However, careful consideration must be given to developing a set of indicators in order to isolate, plan or programme specific impacts. Here, we demonstrate the effectiveness of a workshop-based approach to develop appropriate criteria for selecting environmental indicator for use in SEA. A multi-disciplinary team was used in the approach which consisted of representatives from each of four environmental fields i.e. biodiversity, water, air and climatic factors, together with SEA experts, planning experts, academics and consultants. The team reviewed various sets of criteria, already in existence, for environmental indicator development but not specifically for SEA indicators. The results of this review together with original criteria were applied to the final list agreed upon. Some of the criteria recommended includes, relevance to plan, ability to prioritise, and ability to identify conflict with other plan or SEA objectives

  18. Visual attention spreads broadly but selects information locally.

    Science.gov (United States)

    Shioiri, Satoshi; Honjyo, Hajime; Kashiwase, Yoshiyuki; Matsumiya, Kazumichi; Kuriki, Ichiro

    2016-10-19

    Visual attention spreads over a range around the focus as the spotlight metaphor describes. Spatial spread of attentional enhancement and local selection/inhibition are crucial factors determining the profile of the spatial attention. Enhancement and ignorance/suppression are opposite effects of attention, and appeared to be mutually exclusive. Yet, no unified view of the factors has been provided despite their necessity for understanding the functions of spatial attention. This report provides electroencephalographic and behavioral evidence for the attentional spread at an early stage and selection/inhibition at a later stage of visual processing. Steady state visual evoked potential showed broad spatial tuning whereas the P3 component of the event related potential showed local selection or inhibition of the adjacent areas. Based on these results, we propose a two-stage model of spatial attention with broad spread at an early stage and local selection at a later stage.

  19. Visual selective attention in amnestic mild cognitive impairment.

    Science.gov (United States)

    McLaughlin, Paula M; Anderson, Nicole D; Rich, Jill B; Chertkow, Howard; Murtha, Susan J E

    2014-11-01

    Subtle deficits in visual selective attention have been found in amnestic mild cognitive impairment (aMCI). However, few studies have explored performance on visual search paradigms or the Simon task, which are known to be sensitive to disease severity in Alzheimer's patients. Furthermore, there is limited research investigating how deficiencies can be ameliorated with exogenous support (auditory cues). Sixteen individuals with aMCI and 14 control participants completed 3 experimental tasks that varied in demand and cue availability: visual search-alerting, visual search-orienting, and Simon task. Visual selective attention was influenced by aMCI, auditory cues, and task characteristics. Visual search abilities were relatively consistent across groups. The aMCI participants were impaired on the Simon task when working memory was required, but conflict resolution was similar to controls. Spatially informative orienting cues improved response times, whereas spatially neutral alerting cues did not influence performance. Finally, spatially informative auditory cues benefited the aMCI group more than controls in the visual search task, specifically at the largest array size where orienting demands were greatest. These findings suggest that individuals with aMCI have working memory deficits and subtle deficiencies in orienting attention and rely on exogenous information to guide attention. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Visual selective attention with virtual barriers.

    Science.gov (United States)

    Schneider, Darryl W

    2017-07-01

    Previous studies have shown that interference effects in the flanker task are reduced when physical barriers (e.g., hands) are placed around rather than below a target flanked by distractors. One explanation of this finding is the referential coding hypothesis, whereby the barriers serve as reference objects for allocating attention. In five experiments, the generality of the referential coding hypothesis was tested by investigating whether interference effects are modulated by the placement of virtual barriers (e.g., parentheses). Modulation of flanker interference was found only when target and distractors differed in size and the virtual barriers were beveled wood-grain objects. Under these conditions and those of previous studies, the author conjectures that an impression of depth was produced when the barriers were around the target, such that the target was perceived to be on a different depth plane than the distractors. Perception of depth in the stimulus display might have led to referential coding of the stimuli in three-dimensional (3-D) space, influencing the allocation of attention beyond the horizontal and vertical dimensions. This 3-D referential coding hypothesis is consistent with research on selective attention in 3-D space that shows flanker interference is reduced when target and distractors are separated in depth.

  1. Components of working memory and visual selective attention.

    Science.gov (United States)

    Burnham, Bryan R; Sabia, Matthew; Langan, Catherine

    2014-02-01

    Load theory (Lavie, N., Hirst, A., De Fockert, J. W., & Viding, E. [2004]. Load theory of selective attention and cognitive control. Journal of Experimental Psychology: General, 133, 339-354.) proposes that control of attention depends on the amount and type of load that is imposed by current processing. Specifically, perceptual load should lead to efficient distractor rejection, whereas working memory load (dual-task coordination) should hinder distractor rejection. Studies support load theory's prediction that working memory load will lead to larger distractor effects; however, these studies used secondary tasks that required only verbal working memory and the central executive. The present study examined which other working memory components (visual, spatial, and phonological) influence visual selective attention. Subjects completed an attentional capture task alone (single-task) or while engaged in a working memory task (dual-task). Results showed that along with the central executive, visual and spatial working memory influenced selective attention, but phonological working memory did not. Specifically, attentional capture was larger when visual or spatial working memory was loaded, but phonological working memory load did not affect attentional capture. The results are consistent with load theory and suggest specific components of working memory influence visual selective attention. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  2. Longevity enhances selection of environmental sex determination.

    Science.gov (United States)

    Bull, J J; Bulmer, M G

    1989-12-01

    Environmental sex determination (ESD) is a mechanism in which an individual develops as male or female largely in response to some environmental effect experienced early in life. Its forms range from sex determination by egg incubation temperature in reptiles to sex determination of photoperiod in amphipods. Previous theoretical work as suggested that ESD is favored by natural selection if the fitness consequences of the early environmental experience differ for males and females, so that an individual benefits by being male under some conditions and female under others. A drawback of ESD is that it enables climatic changes to influence the population sex ratio, and such fluctuations select against ESD. This study employed numerical analyses to investigate the balance between these two opposing forces. The negative impact of climatic fluctuations appears to depend greatly on species longevity: substantial between-year fluctuations are of little consequence in selecting against ESD in long-lived species because annual sex ratio fluctuations tend to cancel and thus alter the total population sex ratio only slightly. Thus, if a species is sufficiently long-lived, extreme ESD can be maintained despite only a weak advantage. This result offers one explanation for the failure to demonstrate an advantage for the extreme forms of ESD observed in reptiles.

  3. Visualization of landscape changes and threatening environmental processes using a digital landscape model

    International Nuclear Information System (INIS)

    Svatonova, H; Rybansky, M

    2014-01-01

    Visualizations supported by new geoinformation technologies prove to be appropriate tools for presenting and sharing the research results by professional and general public. The object of the research was to evaluate the benefits of visualizations for the nonexpert users. The subject of evaluation was: the success rate of interpreting the information; forming of a realistic idea of the unknown landscape; and the preference of the users during selection of the appropriate visualization for the purpose of solving the task. The tasks concerned: assessing the current situation and changes of the landscape; assessing the erosion in the landscape; and the ways of their visualizing. To prepare and process the landscape visualizations, it was necessary to select areas that allow tracking of land use changes and representative environmental processes. Then the digital landscape model was created and a number of visualizations were generated. The results of visualization testing show that the users prefer maps to orthophotos, they are able to formulate correct statements concerning the landscape with the help of visualizations, and that the simulated fly throughs represent a very suitable tool supporting formation of a realistic ideas about the landscape

  4. Perceived Visual Deterioration among a Selected Group of Dental ...

    African Journals Online (AJOL)

    To assess the perceived visual deterioration and the determinants among selected dental surgeons in Nigeria. A cross-sectional survey of Resident doctors attending the Revision course of Faculty of Dental Surgery of the National Postgraduate Medical College of Nigeria in Lagos University Teaching Hospital, Lagos, ...

  5. Selected Audio-Visual Materials for Consumer Education. [New Version.

    Science.gov (United States)

    Johnston, William L.

    Ninety-two films, filmstrips, multi-media kits, slides, and audio cassettes, produced between 1964 and 1974, are listed in this selective annotated bibliography on consumer education. The major portion of the bibliography is devoted to films and filmstrips. The main topics of the audio-visual materials include purchasing, advertising, money…

  6. Elementary Teachers' Selection and Use of Visual Models

    Science.gov (United States)

    Lee, Tammy D.; Gail Jones, M.

    2018-02-01

    As science grows in complexity, science teachers face an increasing challenge of helping students interpret models that represent complex science systems. Little is known about how teachers select and use models when planning lessons. This mixed methods study investigated the pedagogical approaches and visual models used by elementary in-service and preservice teachers in the development of a science lesson about a complex system (e.g., water cycle). Sixty-seven elementary in-service and 69 elementary preservice teachers completed a card sort task designed to document the types of visual models (e.g., images) that teachers choose when planning science instruction. Quantitative and qualitative analyses were conducted to analyze the card sort task. Semistructured interviews were conducted with a subsample of teachers to elicit the rationale for image selection. Results from this study showed that both experienced in-service teachers and novice preservice teachers tended to select similar models and use similar rationales for images to be used in lessons. Teachers tended to select models that were aesthetically pleasing and simple in design and illustrated specific elements of the water cycle. The results also showed that teachers were not likely to select images that represented the less obvious dimensions of the water cycle. Furthermore, teachers selected visual models more as a pedagogical tool to illustrate specific elements of the water cycle and less often as a tool to promote student learning related to complex systems.

  7. Evaluation of selected environmental decision support software

    International Nuclear Information System (INIS)

    Sullivan, T.M.; Moskowitz, P.D.; Gitten, M.

    1997-06-01

    Decision Support Software (DSS) continues to be developed to support analysis of decisions pertaining to environmental management. Decision support systems are computer-based systems that facilitate the use of data, models, and structured decision processes in decision making. The optimal DSS should attempt to integrate, analyze, and present environmental information to remediation project managers in order to select cost-effective cleanup strategies. The optimal system should have a balance between the sophistication needed to address the wide range of complicated sites and site conditions present at DOE facilities, and ease of use (e.g., the system should not require data that is typically unknown and should have robust error checking of problem definition through input, etc.). In the first phase of this study, an extensive review of the literature, the Internet, and discussions with sponsors and developers of DSS led to identification of approximately fifty software packages that met the preceding definition

  8. Audio-visual synchrony and feature-selective attention co-amplify early visual processing.

    Science.gov (United States)

    Keitel, Christian; Müller, Matthias M

    2016-05-01

    Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-selective attention. We presented two superimposed Gabor patches that differed in colour and orientation. On each trial, participants were cued to selectively attend to one of the two patches. Over time, spatial frequencies of both patches varied sinusoidally at distinct rates (3.14 and 3.63 Hz), giving rise to pulse-like percepts. A simultaneously presented pure tone carried a frequency modulation at the pulse rate of one of the two visual stimuli to introduce audio-visual synchrony. Pulsed stimulation elicited distinct time-locked oscillatory electrophysiological brain responses. These steady-state responses were quantified in the spectral domain to examine individual stimulus processing under conditions of synchronous versus asynchronous tone presentation and when respective stimuli were attended versus unattended. We found that both, attending to the colour of a stimulus and its synchrony with the tone, enhanced its processing. Moreover, both gain effects combined linearly for attended in-sync stimuli. Our results suggest that audio-visual synchrony can attract attention to specific stimulus features when stimuli overlap in space.

  9. Changes in otoacoustic emissions during selective auditory and visual attention.

    Science.gov (United States)

    Walsh, Kyle P; Pasanen, Edward G; McFadden, Dennis

    2015-05-01

    Previous studies have demonstrated that the otoacoustic emissions (OAEs) measured during behavioral tasks can have different magnitudes when subjects are attending selectively or not attending. The implication is that the cognitive and perceptual demands of a task can affect the first neural stage of auditory processing-the sensory receptors themselves. However, the directions of the reported attentional effects have been inconsistent, the magnitudes of the observed differences typically have been small, and comparisons across studies have been made difficult by significant procedural differences. In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring selective auditory attention (dichotic or diotic listening), selective visual attention, or relative inattention. Within subjects, the differences in nSFOAE magnitude between inattention and attention conditions were about 2-3 dB for both auditory and visual modalities, and the effect sizes for the differences typically were large for both nSFOAE magnitude and phase. These results reveal that the cochlear efferent reflex is differentially active during selective attention and inattention, for both auditory and visual tasks, although they do not reveal how attention is improved when efferent activity is greater.

  10. Learning a New Selection Rule in Visual and Frontal Cortex.

    Science.gov (United States)

    van der Togt, Chris; Stănişor, Liviu; Pooresmaeili, Arezoo; Albantakis, Larissa; Deco, Gustavo; Roelfsema, Pieter R

    2016-08-01

    How do you make a decision if you do not know the rules of the game? Models of sensory decision-making suggest that choices are slow if evidence is weak, but they may only apply if the subject knows the task rules. Here, we asked how the learning of a new rule influences neuronal activity in the visual (area V1) and frontal cortex (area FEF) of monkeys. We devised a new icon-selection task. On each day, the monkeys saw 2 new icons (small pictures) and learned which one was relevant. We rewarded eye movements to a saccade target connected to the relevant icon with a curve. Neurons in visual and frontal cortex coded the monkey's choice, because the representation of the selected curve was enhanced. Learning delayed the neuronal selection signals and we uncovered the cause of this delay in V1, where learning to select the relevant icon caused an early suppression of surrounding image elements. These results demonstrate that the learning of a new rule causes a transition from fast and random decisions to a more considerate strategy that takes additional time and they reveal the contribution of visual and frontal cortex to the learning process. © The Author 2016. Published by Oxford University Press.

  11. Changes in otoacoustic emissions during selective auditory and visual attention

    Science.gov (United States)

    Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

    2015-01-01

    Previous studies have demonstrated that the otoacoustic emissions (OAEs) measured during behavioral tasks can have different magnitudes when subjects are attending selectively or not attending. The implication is that the cognitive and perceptual demands of a task can affect the first neural stage of auditory processing—the sensory receptors themselves. However, the directions of the reported attentional effects have been inconsistent, the magnitudes of the observed differences typically have been small, and comparisons across studies have been made difficult by significant procedural differences. In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring selective auditory attention (dichotic or diotic listening), selective visual attention, or relative inattention. Within subjects, the differences in nSFOAE magnitude between inattention and attention conditions were about 2–3 dB for both auditory and visual modalities, and the effect sizes for the differences typically were large for both nSFOAE magnitude and phase. These results reveal that the cochlear efferent reflex is differentially active during selective attention and inattention, for both auditory and visual tasks, although they do not reveal how attention is improved when efferent activity is greater. PMID:25994703

  12. Dynamic interactions between visual working memory and saccade target selection

    Science.gov (United States)

    Schneegans, Sebastian; Spencer, John P.; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

    2014-01-01

    Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. PMID:25228628

  13. Dynamic interactions between visual working memory and saccade target selection.

    Science.gov (United States)

    Schneegans, Sebastian; Spencer, John P; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

    2014-09-16

    Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. © 2014 ARVO.

  14. Visual Orientation and Directional Selectivity through Thalamic Synchrony

    Science.gov (United States)

    Stanley, Garrett B.; Jin, Jianzhong; Wang, Yushi; Desbordes, Gaëlle; Wang, Qi; Black, Michael J.; Alonso, Jose-Manuel

    2012-01-01

    Thalamic neurons respond to visual scenes by generating synchronous spike trains on the timescale of 10 – 20 ms that are very effective at driving cortical targets. Here we demonstrate that this synchronous activity contains unexpectedly rich information about fundamental properties of visual stimuli. We report that the occurrence of synchronous firing of cat thalamic cells with highly overlapping receptive fields is strongly sensitive to the orientation and the direction of motion of the visual stimulus. We show that this stimulus selectivity is robust, remaining relatively unchanged under different contrasts and temporal frequencies (stimulus velocities). A computational analysis based on an integrate-and-fire model of the direct thalamic input to a layer 4 cortical cell reveals a strong correlation between the degree of thalamic synchrony and the nonlinear relationship between cortical membrane potential and the resultant firing rate. Together, these findings suggest a novel population code in the synchronous firing of neurons in the early visual pathway that could serve as the substrate for establishing cortical representations of the visual scene. PMID:22745507

  15. Visual Data Analysis as an Integral Part of Environmental Management

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Joerg; Bethel, E. Wes; Horsman, Jennifer L.; Hubbard, Susan S.; Krishnan, Harinarayan; Romosan,, Alexandru; Keating, Elizabeth H.; Monroe, Laura; Strelitz, Richard; Moore, Phil; Taylor, Glenn; Torkian, Ben; Johnson, Timothy C.; Gorton, Ian

    2012-10-01

    The U.S. Department of Energy's (DOE) Office of Environmental Management (DOE/EM) currently supports an effort to understand and predict the fate of nuclear contaminants and their transport in natural and engineered systems. Geologists, hydrologists, physicists and computer scientists are working together to create models of existing nuclear waste sites, to simulate their behavior and to extrapolate it into the future. We use visualization as an integral part in each step of this process. In the first step, visualization is used to verify model setup and to estimate critical parameters. High-performance computing simulations of contaminant transport produces massive amounts of data, which is then analyzed using visualization software specifically designed for parallel processing of large amounts of structured and unstructured data. Finally, simulation results are validated by comparing simulation results to measured current and historical field data. We describe in this article how visual analysis is used as an integral part of the decision-making process in the planning of ongoing and future treatment options for the contaminated nuclear waste sites. Lessons learned from visually analyzing our large-scale simulation runs will also have an impact on deciding on treatment measures for other contaminated sites.

  16. Behind the scenes: how visual memory load biases selective attention during processing of visual streams.

    Science.gov (United States)

    Klaver, Peter; Talsma, Durk

    2013-11-01

    We recorded ERPs to investigate whether the visual memory load can bias visual selective attention. Participants memorized one or four letters and then responded to memory-matching letters presented in a relevant color while ignoring distractor letters or letters in an irrelevant color. Stimuli in the relevant color elicited larger frontal selection positivities (FSP) and occipital selection negativities (OSN) compared to irrelevant color stimuli. Only distractors elicited a larger FSP in the high than in the low memory load task. Memory load prolonged the OSN for all letters. Response mapping complexity was also modulated but did not affect the FSP and OSN. Together, the FSP data suggest that high memory load increased distractability. The OSN data suggest that memory load sustained attention to letters in a relevant color until working memory processing was completed, independently of whether the letters were in working memory or not. Copyright © 2013 Society for Psychophysiological Research.

  17. Visual training paired with electrical stimulation of the basal forebrain improves orientation-selective visual acuity in the rat.

    Science.gov (United States)

    Kang, Jun Il; Groleau, Marianne; Dotigny, Florence; Giguère, Hugo; Vaucher, Elvire

    2014-07-01

    The cholinergic afferents from the basal forebrain to the primary visual cortex play a key role in visual attention and cortical plasticity. These afferent fibers modulate acute and long-term responses of visual neurons to specific stimuli. The present study evaluates whether this cholinergic modulation of visual neurons results in cortical activity and visual perception changes. Awake adult rats were exposed repeatedly for 2 weeks to an orientation-specific grating with or without coupling this visual stimulation to an electrical stimulation of the basal forebrain. The visual acuity, as measured using a visual water maze before and after the exposure to the orientation-specific grating, was increased in the group of trained rats with simultaneous basal forebrain/visual stimulation. The increase in visual acuity was not observed when visual training or basal forebrain stimulation was performed separately or when cholinergic fibers were selectively lesioned prior to the visual stimulation. The visual evoked potentials show a long-lasting increase in cortical reactivity of the primary visual cortex after coupled visual/cholinergic stimulation, as well as c-Fos immunoreactivity of both pyramidal and GABAergic interneuron. These findings demonstrate that when coupled with visual training, the cholinergic system improves visual performance for the trained orientation probably through enhancement of attentional processes and cortical plasticity in V1 related to the ratio of excitatory/inhibitory inputs. This study opens the possibility of establishing efficient rehabilitation strategies for facilitating visual capacity.

  18. Visual short-term memory load strengthens selective attention.

    Science.gov (United States)

    Roper, Zachary J J; Vecera, Shaun P

    2014-04-01

    Perceptual load theory accounts for many attentional phenomena; however, its mechanism remains elusive because it invokes underspecified attentional resources. Recent dual-task evidence has revealed that a concurrent visual short-term memory (VSTM) load slows visual search and reduces contrast sensitivity, but it is unknown whether a VSTM load also constricts attention in a canonical perceptual load task. If attentional selection draws upon VSTM resources, then distraction effects-which measure attentional "spill-over"-will be reduced as competition for resources increases. Observers performed a low perceptual load flanker task during the delay period of a VSTM change detection task. We observed a reduction of the flanker effect in the perceptual load task as a function of increasing concurrent VSTM load. These findings were not due to perceptual-level interactions between the physical displays of the two tasks. Our findings suggest that perceptual representations of distractor stimuli compete with the maintenance of visual representations held in memory. We conclude that access to VSTM determines the degree of attentional selectivity; when VSTM is not completely taxed, it is more likely for task-irrelevant items to be consolidated and, consequently, affect responses. The "resources" hypothesized by load theory are at least partly mnemonic in nature, due to the strong correspondence they share with VSTM capacity.

  19. Visual evoked potentials and selective attention to points in space

    Science.gov (United States)

    Van Voorhis, S.; Hillyard, S. A.

    1977-01-01

    Visual evoked potentials (VEPs) were recorded to sequences of flashes delivered to the right and left visual fields while subjects responded promptly to designated stimuli in one field at a time (focused attention), in both fields at once (divided attention), or to neither field (passive). Three stimulus schedules were used: the first was a replication of a previous study (Eason, Harter, and White, 1969) where left- and right-field flashes were delivered quasi-independently, while in the other two the flashes were delivered to the two fields in random order (Bernoulli sequence). VEPs to attended-field stimuli were enhanced at both occipital (O2) and central (Cz) recording sites under all stimulus sequences, but different components were affected at the two scalp sites. It was suggested that the VEP at O2 may reflect modality-specific processing events, while the response at Cz, like its auditory homologue, may index more general aspects of selective attention.

  20. Oculomotor selection underlies feature retention in visual working memory.

    Science.gov (United States)

    Hanning, Nina M; Jonikaitis, Donatas; Deubel, Heiner; Szinte, Martin

    2016-02-01

    Oculomotor selection, spatial task relevance, and visual working memory (WM) are described as three processes highly intertwined and sustained by similar cortical structures. However, because task-relevant locations always constitute potential saccade targets, no study so far has been able to distinguish between oculomotor selection and spatial task relevance. We designed an experiment that allowed us to dissociate in humans the contribution of task relevance, oculomotor selection, and oculomotor execution to the retention of feature representations in WM. We report that task relevance and oculomotor selection lead to dissociable effects on feature WM maintenance. In a first task, in which an object's location was encoded as a saccade target, its feature representations were successfully maintained in WM, whereas they declined at nonsaccade target locations. Likewise, we observed a similar WM benefit at the target of saccades that were prepared but never executed. In a second task, when an object's location was marked as task relevant but constituted a nonsaccade target (a location to avoid), feature representations maintained at that location did not benefit. Combined, our results demonstrate that oculomotor selection is consistently associated with WM, whereas task relevance is not. This provides evidence for an overlapping circuitry serving saccade target selection and feature-based WM that can be dissociated from processes encoding task-relevant locations. Copyright © 2016 the American Physiological Society.

  1. Patch-based visual tracking with online representative sample selection

    Science.gov (United States)

    Ou, Weihua; Yuan, Di; Li, Donghao; Liu, Bin; Xia, Daoxun; Zeng, Wu

    2017-05-01

    Occlusion is one of the most challenging problems in visual object tracking. Recently, a lot of discriminative methods have been proposed to deal with this problem. For the discriminative methods, it is difficult to select the representative samples for the target template updating. In general, the holistic bounding boxes that contain tracked results are selected as the positive samples. However, when the objects are occluded, this simple strategy easily introduces the noises into the training data set and the target template and then leads the tracker to drift away from the target seriously. To address this problem, we propose a robust patch-based visual tracker with online representative sample selection. Different from previous works, we divide the object and the candidates into several patches uniformly and propose a score function to calculate the score of each patch independently. Then, the average score is adopted to determine the optimal candidate. Finally, we utilize the non-negative least square method to find the representative samples, which are used to update the target template. The experimental results on the object tracking benchmark 2013 and on the 13 challenging sequences show that the proposed method is robust to the occlusion and achieves promising results.

  2. Subcortical orientation biases explain orientation selectivity of visual cortical cells.

    Science.gov (United States)

    Vidyasagar, Trichur R; Jayakumar, Jaikishan; Lloyd, Errol; Levichkina, Ekaterina V

    2015-04-01

    The primary visual cortex of carnivores and primates shows an orderly progression of domains of neurons that are selective to a particular orientation of visual stimuli such as bars and gratings. We recorded from single-thalamic afferent fibers that terminate in these domains to address the issue whether the orientation sensitivity of these fibers could form the basis of the remarkable orientation selectivity exhibited by most cortical cells. We first performed optical imaging of intrinsic signals to obtain a map of orientation domains on the dorsal aspect of the anaesthetized cat's area 17. After confirming using electrophysiological recordings the orientation preferences of single neurons within one or two domains in each animal, we pharmacologically silenced the cortex to leave only the afferent terminals active. The inactivation of cortical neurons was achieved by the superfusion of either kainic acid or muscimol. Responses of single geniculate afferents were then recorded by the use of high impedance electrodes. We found that the orientation preferences of the afferents matched closely with those of the cells in the orientation domains that they terminated in (Pearson's r = 0.633, n = 22, P = 0.002). This suggests a possible subcortical origin for cortical orientation selectivity. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  3. Simple Instrumental and Visual Tests for Nonlaboratory Environmental Control

    Directory of Open Access Journals (Sweden)

    L. P. Eksperiandova

    2016-01-01

    Full Text Available Proposed are simple and available techniques that can be used for rapid and reliable environmental control specifically of natural water by means of instrumental and visual tests in outdoor conditions. Developed are the chemical colorimetric modes for fast detection of socially dangerous trace impurities in water such as Co(II, Pd(II, and Rh(III as well as NO2--ions and Fe(III serving as model impurities. Application of portable digital devices and scanner allows estimating the color coordinates and increasing the accuracy and sensitivity of the tests. The combination of complex formation with preconcentration of colored complexes replaces the sensitive but time-consuming and capricious kinetic method that is usually used for this purpose at the more convenient and reliable colorimetric method. As the test tools, the following ones are worked out: polyurethane foam tablets with sorbed colored complexes, the two-layer paper sandwich packaged in slide adapter and saturated by reagents, and polyethylene terephthalate blister with dried reagents. Fast analysis of polyurethane foam tablets is realized using a pocket digital RGB-colorimeter or portable photometer. Express analysis of two-layer paper sandwich or polyethylene terephthalate blister is realized by visual and instrumental tests. The metrological characteristics of the developed visual and instrumental express analysis techniques are estimated.

  4. Socio-environmental education, imaginary and Visual Arts

    Directory of Open Access Journals (Sweden)

    Graciela René Ormezzano

    2013-01-01

    Full Text Available This article is a bibliographic research that chooses the Maffesoli aesthetic worldview and speaks about social imaginary as a foundation for this study. In addition, it does a little speech about some educational politics that promote the environmental education and the mainstreaming and, finally, it discusses the relevance of visual arts in the transdisciplinary teaching-learning process doing a methodological approach that considers that it is able to be developed at various levels of formal education or non-formal education. The suggested mode of execution is based on the use of workshops as teaching methodology, joining the visual arts with various fields of knowledge with which they can relate to address the issue of socio-environmental education. The proposal addresses the need to return to the inventive experience for the purpose of (rediscover the action of raising and educating yourself without losing sight of all. This research looks for the meaning of life in society, transforming the human perception of the Cosmos, respecting the natural environment and complementarity of multiple cultures.

  5. Visual coding with a population of direction-selective neurons.

    Science.gov (United States)

    Fiscella, Michele; Franke, Felix; Farrow, Karl; Müller, Jan; Roska, Botond; da Silveira, Rava Azeredo; Hierlemann, Andreas

    2015-10-01

    The brain decodes the visual scene from the action potentials of ∼20 retinal ganglion cell types. Among the retinal ganglion cells, direction-selective ganglion cells (DSGCs) encode motion direction. Several studies have focused on the encoding or decoding of motion direction by recording multiunit activity, mainly in the visual cortex. In this study, we simultaneously recorded from all four types of ON-OFF DSGCs of the rabbit retina using a microelectronics-based high-density microelectrode array (HDMEA) and decoded their concerted activity using probabilistic and linear decoders. Furthermore, we investigated how the modification of stimulus parameters (velocity, size, angle of moving object) and the use of different tuning curve fits influenced decoding precision. Finally, we simulated ON-OFF DSGC activity, based on real data, in order to understand how tuning curve widths and the angular distribution of the cells' preferred directions influence decoding performance. We found that probabilistic decoding strategies outperformed, on average, linear methods and that decoding precision was robust to changes in stimulus parameters such as velocity. The removal of noise correlations among cells, by random shuffling trials, caused a drop in decoding precision. Moreover, we found that tuning curves are broad in order to minimize large errors at the expense of a higher average error, and that the retinal direction-selective system would not substantially benefit, on average, from having more than four types of ON-OFF DSGCs or from a perfect alignment of the cells' preferred directions. Copyright © 2015 the American Physiological Society.

  6. Dynamic stereoscopic selective visual attention (dssva): integrating motion and shape with depth in video segmentation

    OpenAIRE

    López Bonal, María Teresa; Fernández Caballero, Antonio; Saiz Valverde, Sergio

    2008-01-01

    Depth inclusion as an important parameter for dynamic selective visual attention is presented in this article. The model introduced in this paper is based on two previously developed models, dynamic selective visual attention and visual stereoscopy, giving rise to the so-called dynamic stereoscopic selective visual attention method. The three models are based on the accumulative computation problem-solving method. This paper shows how software reusability enables enhancing results in vision r...

  7. Visualizing and Understanding Socio-Environmental Dynamics in Baltimore

    Science.gov (United States)

    Zaitchik, B. F.; Omeara, K.; Guikema, S.; Scott, A.; Bessho, A.; Logan, T. M.

    2015-12-01

    The City of Baltimore, like any city, is the sum of its component neighborhoods, institutions, businesses, cultures, and, ultimately, its people. It is also an organism in its own right, with distinct geography, history, infrastructure, and environments that shape its residents even as it is shaped by them. Sometimes these interactions are obvious but often they are not; while basic economic patterns are widely documented, the distribution of socio-spatial and environmental connections often hides below the surface, as does the potential that those connections hold. Here we present results of a collaborative initiative on the geography, design, and policy of socio-environmental dynamics of Baltimore. Geospatial data derived from satellite imagery, demographic databases, social media feeds, infrastructure plans, and in situ environmental networks, among other sources, are applied to generate an interactive portrait of Baltimore City's social, health, and well-being dynamics. The layering of data serves as a platform for visualizing the interconnectedness of the City and as a database for modeling risk interactions, vulnerabilities, and strengths within and between communities. This presentation will provide an overview of project findings and highlight linkages to education and policy.

  8. Visual cells remember earlier applied target: plasticity of orientation selectivity.

    Directory of Open Access Journals (Sweden)

    Narcis Ghisovan

    Full Text Available BACKGROUND: A canonical proposition states that, in mature brain, neurons responsive to sensory stimuli are tuned to specific properties installed shortly after birth. It is amply demonstrated that that neurons in adult visual cortex of cats are orientation-selective that is they respond with the highest firing rates to preferred oriented stimuli. METHODOLOGY/PRINCIPAL FINDINGS: In anesthetized cats, prepared in a conventional fashion for single cell recordings, the present investigation shows that presenting a stimulus uninterruptedly at a non-preferred orientation for twelve minutes induces changes in orientation preference. Across all conditions orientation tuning curves were investigated using a trial by trial method. Contrary to what has been previously reported with shorter adaptation duration, twelve minutes of adaptation induces mostly attractive shifts, i.e. toward the adapter. After a recovery period allowing neurons to restore their original orientation tuning curves, we carried out a second adaptation which produced three major results: (1 more frequent attractive shifts, (2 an increase of their magnitude, and (3 an additional enhancement of responses at the new or acquired preferred orientation. Additionally, we also show that the direction of shifts depends on the duration of the adaptation: shorter adaptation in most cases produces repulsive shifts, whereas adaptation exceeding nine minutes results in attractive shifts, in the same unit. Consequently, shifts in preferred orientation depend on the duration of adaptation. CONCLUSION/SIGNIFICANCE: The supplementary response improvements indicate that neurons in area 17 keep a memory trace of the previous stimulus properties, thereby upgrading cellular performance. It also highlights the dynamic nature of basic neuronal properties in adult cortex since repeated adaptations modified both the orientation tuning selectivity and the response strength to the preferred orientation. These

  9. Enhancing Auditory Selective Attention Using a Visually Guided Hearing Aid

    Science.gov (United States)

    2017-01-01

    Purpose Listeners with hearing loss, as well as many listeners with clinically normal hearing, often experience great difficulty segregating talkers in a multiple-talker sound field and selectively attending to the desired “target” talker while ignoring the speech from unwanted “masker” talkers and other sources of sound. This listening situation forms the classic “cocktail party problem” described by Cherry (1953) that has received a great deal of study over the past few decades. In this article, a new approach to improving sound source segregation and enhancing auditory selective attention is described. The conceptual design, current implementation, and results obtained to date are reviewed and discussed in this article. Method This approach, embodied in a prototype “visually guided hearing aid” (VGHA) currently used for research, employs acoustic beamforming steered by eye gaze as a means for improving the ability of listeners to segregate and attend to one sound source in the presence of competing sound sources. Results The results from several studies demonstrate that listeners with normal hearing are able to use an attention-based “spatial filter” operating primarily on binaural cues to selectively attend to one source among competing spatially distributed sources. Furthermore, listeners with sensorineural hearing loss generally are less able to use this spatial filter as effectively as are listeners with normal hearing especially in conditions high in “informational masking.” The VGHA enhances auditory spatial attention for speech-on-speech masking and improves signal-to-noise ratio for conditions high in “energetic masking.” Visual steering of the beamformer supports the coordinated actions of vision and audition in selective attention and facilitates following sound source transitions in complex listening situations. Conclusions Both listeners with normal hearing and with sensorineural hearing loss may benefit from the acoustic

  10. Selected environmental applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    2001-01-01

    NAA is very useful for the determination of trace and minor elements in many environmental applications. While instrumental NAA (INAA) has a number of valid applications in this field, radiochemical NAA (RNAA) prior to, or post irradiation provides some significant advantages. One of the major focus points for environmental applications of NAA is to assess the magnitude of various pollutants. This paper discusses doing this via two methods, namely air monitoring and biological monitoring. (author)

  11. Environmental impact assessment - a selected bibliography

    International Nuclear Information System (INIS)

    Lawson, W.J.

    1989-01-01

    This bibliography of literature relevant to the environmental impact assessment process is essentially a list of material dealing with the environmental impact assessment process held by Griffith University Library. The list is however well supplemented with citations of material not held in the Griffith University Library. Some economic and social impact assessment citations have been included in the bibliography, as the the environmental impact assessment concept has been interpreted very broadly. The citations are arranged according to broad subject areas, such as methodology, critical reviews, social impacts etc. Citations in each of these subject areas, which are listed in the table of contents, are identified by prefixes which are given in parentheses before the subjects headings. Within each subject area the citations are arragend in alphabetic author sequence

  12. Visual search in scenes involves selective and non-selective pathways

    Science.gov (United States)

    Wolfe, Jeremy M; Vo, Melissa L-H; Evans, Karla K; Greene, Michelle R

    2010-01-01

    How do we find objects in scenes? For decades, visual search models have been built on experiments in which observers search for targets, presented among distractor items, isolated and randomly arranged on blank backgrounds. Are these models relevant to search in continuous scenes? This paper argues that the mechanisms that govern artificial, laboratory search tasks do play a role in visual search in scenes. However, scene-based information is used to guide search in ways that had no place in earlier models. Search in scenes may be best explained by a dual-path model: A “selective” path in which candidate objects must be individually selected for recognition and a “non-selective” path in which information can be extracted from global / statistical information. PMID:21227734

  13. Gender and environmental influences on visual acuity in Owerri ...

    African Journals Online (AJOL)

    olayemitoyin

    1Optometry Unit, Eye Clinic, Federal Medical Centre, Owerri, Imo State, 2Department of Physiology, College ... Visual acuity (V.A.) is a measure of visual function in health and disease. ..... environment especially during harmattan and dry.

  14. Selective visualization of gene structure with ultraviolet light

    International Nuclear Information System (INIS)

    Wang, Z.; Becker, M.M.

    1988-01-01

    The ability of the ultraviolet (UV) footprinting technique to detect chromatin has been investigated in vitro. Two basic types of chromatin, a phased nucleosome and a phased nucleosome containing a phased H1 protein, have been reconstituted onto a cloned 5S ribosomal RNA gene from sea urchin. The histone-DNA interactions in each complex have been probed with exonuclease III, DNase I, dimethyl sulfate, and UV light. Whereas DNase I and exonuclease III readily detect interactions between histones and DNA, UV light and dimethyl sulfate do not. In contrast to histone-DNA interactions, we demonstrate that intimate sequence-specific contacts between the same sea urchin 5S DNA and the Xenopus laevis transcription factor IIIA (TFIIIA) are readily detected with UV light. Since the sensitivity of UV light for TFIIIA contacts is similar to its sensitivity for other regulatory protein-DNA contacts, these studies demonstrate the feasibility of using UV light to selectively visualize regulatory protein-DNA interactions in vivo with little or no interference from histone-DNA interactions

  15. Selected aspects of environmental protection in Poland

    International Nuclear Information System (INIS)

    Obarska-Pempkowaik, Hanna; Bolt, Adam

    2001-01-01

    Environmental deterioration in Poland particularly in 1970's, was a result of an incorrect investment policy and indifferent attitude to the principles of the preservation of nature. Water resources, as part of the environment were affected accordingly. Shortage in water resources is caused by deterioration activity of the industrial, the progressing urban development, overconsumption caused by low prices of water and low status the legislation connected with the natural environment. The European integration processes going on make it necessary to adapt the Polish standards and technological solutions in the sphere of the environmental protection to the standards required by the European Union. The destroyed natural environment cannot secure living at a relatively high standard. Hence the concept of ecological safety based on the conviction that there is no high quality J. life without a high quality of the surrounding environment' has more followers. The main purpose of this paper is to describe the nature and scope of water pollution in Poland with an emphasis on current threats to water quality, with achievements in last decade and background of other European countries. (Original)

  16. How to Visualize and Communicate Challenges in Climate and Environmental Sciences?

    Science.gov (United States)

    Vicari, R.; Schertzer, D. J. M.; Deutsch, J. C.

    2014-12-01

    The challenges of climate and environmental sciences need a renewed dialogue with a large spectrum of stakeholders, ranging from the general publics to specialists. This requires a better use of sophisticated visualization techniques to both forward the information and to follow the corresponding flow of information. A particular case of interest is the question of resilience to extreme weather events that also relies on increasing awareness of urban communities. This research looks at the development of exploration techniques of unstructured Big Data. Indeed access to information on environmental and climate sciences has hugely increased in terms of variety and quantity, as a consequence of different factors, among others the development of public relations by research institutes and the pervasive role of digital media (Bucchi 2013; Trench 2008). We are left with unthinkable amounts of information from blogs, social networks postings, public speeches, press releases, articles, etc. It is possible now to explore and visualize patterns followed by digital information with the support of automated analysis tools. On the other hand these techniques can provide important insights on how different techniques of visual communication can impact on urban resilience to extreme weather. The selected case studies correspond to several research projects under the umbrella of the Chair "Hydrology for resilient cities" aimed to develop and test new solutions in urban hydrology that will contribute to the resilience of our cities to extreme weather. These research projects - ranging from regional projects (e.g. RadX@IdF), European projects (e.g. Blue Green Dream and RainGain), to worldwide collaborations (e.g. TOMACS) - include awareness raising and capacity building activities aimed to foster cooperation between scientists, professionals, and beneficiaries. This presentation will explore how visualization techniques can be used in the above mentioned projects in order to support

  17. Assessing environmental features related to mental health: a reliability study of visual streetscape images.

    Science.gov (United States)

    Wu, Yu-Tzu; Nash, Paul; Barnes, Linda E; Minett, Thais; Matthews, Fiona E; Jones, Andy; Brayne, Carol

    2014-10-22

    An association between depressive symptoms and features of built environment has been reported in the literature. A remaining research challenge is the development of methods to efficiently capture pertinent environmental features in relevant study settings. Visual streetscape images have been used to replace traditional physical audits and directly observe the built environment of communities. The aim of this work is to examine the inter-method reliability of the two audit methods for assessing community environments with a specific focus on physical features related to mental health. Forty-eight postcodes in urban and rural areas of Cambridgeshire, England were randomly selected from an alphabetical list of streets hosted on a UK property website. The assessment was conducted in July and August 2012 by both physical and visual image audits based on the items in Residential Environment Assessment Tool (REAT), an observational instrument targeting the micro-scale environmental features related to mental health in UK postcodes. The assessor used the images of Google Street View and virtually "walked through" the streets to conduct the property and street level assessments. Gwet's AC1 coefficients and Bland-Altman plots were used to compare the concordance of two audits. The results of conducting the REAT by visual image audits generally correspond to direct observations. More variations were found in property level items regarding physical incivilities, with broad limits of agreement which importantly lead to most of the variation in the overall REAT score. Postcodes in urban areas had lower consistency between the two methods than rural areas. Google Street View has the potential to assess environmental features related to mental health with fair reliability and provide a less resource intense method of assessing community environments than physical audits.

  18. Resources for Designing, Selecting and Teaching with Visualizations in the Geoscience Classroom

    Science.gov (United States)

    Kirk, K. B.; Manduca, C. A.; Ormand, C. J.; McDaris, J. R.

    2009-12-01

    Geoscience is a highly visual field, and effective use of visualizations can enhance student learning, appeal to students’ emotions and help them acquire skills for interpreting visual information. The On the Cutting Edge website, “Teaching Geoscience with Visualizations” presents information of interest to faculty who are teaching with visualizations, as well as those who are designing visualizations. The website contains best practices for effective visualizations, drawn from the educational literature and from experts in the field. For example, a case is made for careful selection of visualizations so that faculty can align the correct visualization with their teaching goals and audience level. Appropriate visualizations will contain the desired geoscience content without adding extraneous information that may distract or confuse students. Features such as labels, arrows and contextual information can help guide students through imagery and help to explain the relevant concepts. Because students learn by constructing their own mental image of processes, it is helpful to select visualizations that reflect the same type of mental picture that students should create. A host of recommended readings and presentations from the On the Cutting Edge visualization workshops can provide further grounding for the educational uses of visualizations. Several different collections of visualizations, datasets with visualizations and visualization tools are available on the website. Examples include animations of tsunamis, El Nino conditions, braided stream formation and mountain uplift. These collections are grouped by topic and range from simple animations to interactive models. A series of example activities that incorporate visualizations into classroom and laboratory activities illustrate various tactics for using these materials in different types of settings. Activities cover topics such as ocean circulation, land use changes, earthquake simulations and the use of

  19. Uncertainty associated with selected environmental transport models

    International Nuclear Information System (INIS)

    Little, C.A.; Miller, C.W.

    1979-11-01

    A description is given of the capabilities of several models to predict accurately either pollutant concentrations in environmental media or radiological dose to human organs. The models are discussed in three sections: aquatic or surface water transport models, atmospheric transport models, and terrestrial and aquatic food chain models. Using data published primarily by model users, model predictions are compared to observations. This procedure is infeasible for food chain models and, therefore, the uncertainty embodied in the models input parameters, rather than the model output, is estimated. Aquatic transport models are divided into one-dimensional, longitudinal-vertical, and longitudinal-horizontal models. Several conclusions were made about the ability of the Gaussian plume atmospheric dispersion model to predict accurately downwind air concentrations from releases under several sets of conditions. It is concluded that no validation study has been conducted to test the predictions of either aquatic or terrestrial food chain models. Using the aquatic pathway from water to fish to an adult for 137 Cs as an example, a 95% one-tailed confidence limit interval for the predicted exposure is calculated by examining the distributions of the input parameters. Such an interval is found to be 16 times the value of the median exposure. A similar one-tailed limit for the air-grass-cow-milk-thyroid for 131 I and infants was 5.6 times the median dose. Of the three model types discussed in this report,the aquatic transport models appear to do the best job of predicting observed concentrations. However, this conclusion is based on many fewer aquatic validation data than were availaable for atmospheric model validation

  20. Time-varying spatial data integration and visualization: 4 Dimensions Environmental Observations Platform (4-DEOS)

    Science.gov (United States)

    Paciello, Rossana; Coviello, Irina; Filizzola, Carolina; Genzano, Nicola; Lisi, Mariano; Mazzeo, Giuseppe; Pergola, Nicola; Sileo, Giancanio; Tramutoli, Valerio

    2014-05-01

    In environmental studies the integration of heterogeneous and time-varying data, is a very common requirement for investigating and possibly visualize correlations among physical parameters underlying the dynamics of complex phenomena. Datasets used in such kind of applications has often different spatial and temporal resolutions. In some case superimposition of asynchronous layers is required. Traditionally the platforms used to perform spatio-temporal visual data analyses allow to overlay spatial data, managing the time using 'snapshot' data model, each stack of layers being labeled with different time. But this kind of architecture does not incorporate the temporal indexing neither the third spatial dimension which is usually given as an independent additional layer. Conversely, the full representation of a generic environmental parameter P(x,y,z,t) in the 4D space-time domain could allow to handle asynchronous datasets as well as less traditional data-products (e.g. vertical sections, punctual time-series, etc.) . In this paper we present the 4 Dimensions Environmental Observation Platform (4-DEOS), a system based on a web services architecture Client-Broker-Server. This platform is a new open source solution for both a timely access and an easy integration and visualization of heterogeneous (maps, vertical profiles or sections, punctual time series, etc.) asynchronous, geospatial products. The innovative aspect of the 4-DEOS system is that users can analyze data/products individually moving through time, having also the possibility to stop the display of some data/products and focus on other parameters for better studying their temporal evolution. This platform gives the opportunity to choose between two distinct display modes for time interval or for single instant. Users can choose to visualize data/products in two ways: i) showing each parameter in a dedicated window or ii) visualize all parameters overlapped in a single window. A sliding time bar, allows

  1. Influence of olfactory and visual cover on nest site selection and nest success for grassland-nesting birds.

    Science.gov (United States)

    Fogarty, Dillon T; Elmore, R Dwayne; Fuhlendorf, Samuel D; Loss, Scott R

    2017-08-01

    Habitat selection by animals is influenced by and mitigates the effects of predation and environmental extremes. For birds, nest site selection is crucial to offspring production because nests are exposed to extreme weather and predation pressure. Predators that forage using olfaction often dominate nest predator communities; therefore, factors that influence olfactory detection (e.g., airflow and weather variables, including turbulence and moisture) should influence nest site selection and survival. However, few studies have assessed the importance of olfactory cover for habitat selection and survival. We assessed whether ground-nesting birds select nest sites based on visual and/or olfactory cover. Additionally, we assessed the importance of visual cover and airflow and weather variables associated with olfactory cover in influencing nest survival. In managed grasslands in Oklahoma, USA, we monitored nests of Northern Bobwhite ( Colinus virginianus ), Eastern Meadowlark ( Sturnella magna ), and Grasshopper Sparrow ( Ammodramus savannarum ) during 2015 and 2016. To assess nest site selection, we compared cover variables between nests and random points. To assess factors influencing nest survival, we used visual cover and olfactory-related measurements (i.e., airflow and weather variables) to model daily nest survival. For nest site selection, nest sites had greater overhead visual cover than random points, but no other significant differences were found. Weather variables hypothesized to influence olfactory detection, specifically precipitation and relative humidity, were the best predictors of and were positively related to daily nest survival. Selection for overhead cover likely contributed to mitigation of thermal extremes and possibly reduced detectability of nests. For daily nest survival, we hypothesize that major nest predators focused on prey other than the monitored species' nests during high moisture conditions, thus increasing nest survival on these

  2. Active listening impairs visual perception and selectivity: an ERP study of auditory dual-task costs on visual attention.

    Science.gov (United States)

    Gherri, Elena; Eimer, Martin

    2011-04-01

    The ability to drive safely is disrupted by cell phone conversations, and this has been attributed to a diversion of attention from the visual environment. We employed behavioral and ERP measures to study whether the attentive processing of spoken messages is, in itself, sufficient to produce visual-attentional deficits. Participants searched for visual targets defined by a unique feature (Experiment 1) or feature conjunction (Experiment 2), and simultaneously listened to narrated text passages that had to be recalled later (encoding condition), or heard backward-played speech sounds that could be ignored (control condition). Responses to targets were slower in the encoding condition, and ERPs revealed that the visual processing of search arrays and the attentional selection of target stimuli were less efficient in the encoding relative to the control condition. Results demonstrate that the attentional processing of visual information is impaired when concurrent spoken messages are encoded and maintained, in line with cross-modal links in selective attention, but inconsistent with the view that attentional resources are modality-specific. The distraction of visual attention by active listening could contribute to the adverse effects of cell phone use on driving performance.

  3. More insight into the interplay of response selection and visual attention in dual-tasks: masked visual search and response selection are performed in parallel.

    Science.gov (United States)

    Reimer, Christina B; Schubert, Torsten

    2017-09-15

    Both response selection and visual attention are limited in capacity. According to the central bottleneck model, the response selection processes of two tasks in a dual-task situation are performed sequentially. In conjunction search, visual attention is required to select the items and to bind their features (e.g., color and form), which results in a serial search process. Search time increases as items are added to the search display (i.e., set size effect). When the search display is masked, visual attention deployment is restricted to a brief period of time and target detection decreases as a function of set size. Here, we investigated whether response selection and visual attention (i.e., feature binding) rely on a common or on distinct capacity limitations. In four dual-task experiments, participants completed an auditory Task 1 and a conjunction search Task 2 that were presented with an experimentally modulated temporal interval between them (Stimulus Onset Asynchrony, SOA). In Experiment 1, Task 1 was a two-choice discrimination task and the conjunction search display was not masked. In Experiment 2, the response selection difficulty in Task 1 was increased to a four-choice discrimination and the search task was the same as in Experiment 1. We applied the locus-of-slack method in both experiments to analyze conjunction search time, that is, we compared the set size effects across SOAs. Similar set size effects across SOAs (i.e., additive effects of SOA and set size) would indicate sequential processing of response selection and visual attention. However, a significantly smaller set size effect at short SOA compared to long SOA (i.e., underadditive interaction of SOA and set size) would indicate parallel processing of response selection and visual attention. In both experiments, we found underadditive interactions of SOA and set size. In Experiments 3 and 4, the conjunction search display in Task 2 was masked. Task 1 was the same as in Experiments 1 and 2

  4. Visual Environment for Rich Data Interpretation (VERDI) program for environmental modeling systems

    Science.gov (United States)

    VERDI is a flexible, modular, Java-based program used for visualizing multivariate gridded meteorology, emissions and air quality modeling data created by environmental modeling systems such as the CMAQ model and WRF.

  5. Visual Images as a Motivational Bridge to Pro-Environmental Behaviour: A Cognitive Approach

    OpenAIRE

    Boomsma, Christine

    2013-01-01

    Communicating climate change and other long-term environmental issues to the wider public is a challenging process involving many barriers to action. Visualisations have the ability to overcome these barriers. Furthermore, the benefits of visual images over verbal information have been supported. However, there is a lack of research on how visual images can motivate behaviour. Based on Elaborated Intrusion theory, it is proposed that visual images can be internalised as mental images which ca...

  6. Do the Contents of Visual Working Memory Automatically Influence Attentional Selection During Visual Search?

    OpenAIRE

    Woodman, Geoffrey F.; Luck, Steven J.

    2007-01-01

    In many theories of cognition, researchers propose that working memory and perception operate interactively. For example, in previous studies researchers have suggested that sensory inputs matching the contents of working memory will have an automatic advantage in the competition for processing resources. The authors tested this hypothesis by requiring observers to perform a visual search task while concurrently maintaining object representations in visual working memory. The hypothesis that ...

  7. Interaction of hypertension and age in visual selective attention performance.

    Science.gov (United States)

    Madden, D J; Blumenthal, J A

    1998-01-01

    Previous research suggests that some aspects of cognitive performance decline as a joint function of age and hypertension. In this experiment, 51 unmedicated individuals with mild essential hypertension and 48 normotensive individuals, 18-78 years of age, performed a visual search task. The estimated time required to identify a display character and shift attention between display positions increased with age. This attention shift time did not differ significantly between hypertensive and normotensive participants, but regression analyses indicated some mediation of the age effect by blood pressure. For individuals less than 60 years of age, the error rate was greater for hypertensive than for normotensive participants. Although the present design could detect effects of only moderate to large size, the results suggest that effects of hypertension may be more evident in a relatively general measure of performance (mean error rate) than in the speed of shifting visual attention.

  8. Environmental change disrupts communication and sexual selection in a stickleback population.

    Science.gov (United States)

    Candolin, Ulrika; Tukiainen, Iina; Bertell, Elina

    2016-04-01

    Environmental change that disrupts communication during mate choice and alters sexual selection could influence population dynamics. Yet little is known about such long-term effects. We investigated experimentally the consequences that disrupted visual communication during mate choice has for the quantity and viability of offspring produced in a threespine stickleback population (Gasterosteus aculeatus). We further related the results to long-term monitoring of population dynamics in the field to determine if changes are apparent under natural conditions. The results show that impaired visual communication because of algal blooms reduces reliability of male visual signals as indicators of offspring survival during their first weeks of life. This relaxes sexual selection but has no effect on the number of offspring hatching, as most males have a high hatching success in turbid water. Despite eutrophication and high turbidity levels that interfere with communication during mate choice, the population has grown during recent decades. Large numbers of offspring hatching, combined with high variation in juvenile fitness, has probably shifted selection to later life history stages and maintained a viable population. Together with reduced cost of sexual selection and ongoing ecosystem changes caused by human activities, this could have promoted population growth. These results point to the complexity of ecosystems and the necessity to consider all influencing factors when attempting to understand impacts of human activities on populations.

  9. Data Visualization and Feature Selection Methods in Gel-based Proteomics

    DEFF Research Database (Denmark)

    Silva, Tomé Santos; Richard, Nadege; Dias, Jorge P.

    2014-01-01

    -based proteomics, summarizing the current state of research within this field. Particular focus is given on discussing the usefulness of available multivariate analysis tools both for data visualization and feature selection purposes. Visual examples are given using a real gel-based proteomic dataset as basis....

  10. What Is the Unit of Visual Attention? Object for Selection, but Boolean Map for Access

    Science.gov (United States)

    Huang, Liqiang

    2010-01-01

    In the past 20 years, numerous theories and findings have suggested that the unit of visual attention is the object. In this study, I first clarify 2 different meanings of unit of visual attention, namely the unit of access in the sense of measurement and the unit of selection in the sense of division. In accordance with this distinction, I argue…

  11. Simulating the Role of Visual Selective Attention during the Development of Perceptual Completion

    Science.gov (United States)

    Schlesinger, Matthew; Amso, Dima; Johnson, Scott P.

    2012-01-01

    We recently proposed a multi-channel, image-filtering model for simulating the development of visual selective attention in young infants (Schlesinger, Amso & Johnson, 2007). The model not only captures the performance of 3-month-olds on a visual search task, but also implicates two cortical regions that may play a role in the development of…

  12. Functional MRI mapping of visual function and selective attention for performance assessment and presurgical planning using conjunctive visual search.

    Science.gov (United States)

    Parker, Jason G; Zalusky, Eric J; Kirbas, Cemil

    2014-03-01

    Accurate mapping of visual function and selective attention using fMRI is important in the study of human performance as well as in presurgical treatment planning of lesions in or near visual centers of the brain. Conjunctive visual search (CVS) is a useful tool for mapping visual function during fMRI because of its greater activation extent compared with high-capacity parallel search processes. The purpose of this work was to develop and evaluate a CVS that was capable of generating consistent activation in the basic and higher level visual areas of the brain by using a high number of distractors as well as an optimized contrast condition. Images from 10 healthy volunteers were analyzed and brain regions of greatest activation and deactivation were determined using a nonbiased decomposition of the results at the hemisphere, lobe, and gyrus levels. The results were quantified in terms of activation and deactivation extent and mean z-statistic. The proposed CVS was found to generate robust activation of the occipital lobe, as well as regions in the middle frontal gyrus associated with coordinating eye movements and in regions of the insula associated with task-level control and focal attention. As expected, the task demonstrated deactivation patterns commonly implicated in the default-mode network. Further deactivation was noted in the posterior region of the cerebellum, most likely associated with the formation of optimal search strategy. We believe the task will be useful in studies of visual and selective attention in the neuroscience community as well as in mapping visual function in clinical fMRI.

  13. Images of climate change in the news: Visual framing of a global environmental issue

    Science.gov (United States)

    Rebich Hespanha, S.; Rice, R. E.; Montello, D. R.; Retzloff, S.; Tien, S.

    2012-12-01

    News media play a powerful role in disseminating and framing information and shaping public opinion on environmental issues. Choices of text and images that are made by the creators and distributors of news media not only influence public perception about which issues are important, but also surreptitiously lead consumers of these media to perceive certain aspects or perspectives on an issue while neglecting to consider others. Our research was motivated by a desire to obtain comprehensive quantitative and qualitative understanding of the types of information - both textual and visual -- that have been provided to the U.S. public over the past several decades through news reports about climate change. As part of this project, we documented and examined 118 themes in 19 categories presented in 350 randomly-selected visual images from U.S. news coverage of global climate change between 1969 and late 2009. This study examines how the use of imagery in print news positions climate change within public and private arenas and how it emphasizes particular geographic, political, scientific, technological, sociological, and ideological aspects of the issue.

  14. Young Children's Visual Attention to Environmental Print as Measured by Eye Tracker Analysis

    Science.gov (United States)

    Neumann, Michelle M.; Acosta, Camillia; Neumann, David L.

    2014-01-01

    Environmental print, such as signs and product labels, consist of both print and contextual cues designed to attract the visual attention of the reader. However, contextual cues may draw young children's attention away from the print, thus questioning the value of environmental print in early reading development. Eye tracker technology was used to…

  15. Using a Three-Dimensional Interactive Model To Teach Environmental Concepts to Visually Impaired Children.

    Science.gov (United States)

    Budd, Julia M.; LaGrow, Steven J.

    2000-01-01

    A study investigated the efficacy of using the Buddy Road Kit, an interactive, wooden model, to teach environmental concepts to 4 children with visual impairments ages 7 to 11 years old. Results indicate the model was effective in teaching environmental concepts and traffic safety to the children involved. (Contains references.) (CR)

  16. Special Issue of Selected Papers from Visualization and Data Analysis 2011

    Science.gov (United States)

    Kao, David L.; Wong, Pak Chung

    2012-01-01

    This special issue features the best papers that were selected from the 18th SPIE Conference on Visualization and Data Analysis (VDA 2011). This annual conference is a major international forum for researchers and practitioners interested in data visualization and analytics research, development, and applications. VDA 2011 received 42 high-quality submissions from around the world. Twenty-four papers were selected for full conference papers. The top five papers have been expanded and reviewed for this special issue.

  17. Environmental Factors that Determine Visual Skill Development of ...

    African Journals Online (AJOL)

    2017-10-26

    Oct 26, 2017 ... development and environmental risk factors influencing it provides useful guide for early ..... sporting activities, video games, and play with large mobile toys .... in the brain: Implications for explaining autism. Science. 2005 ...

  18. The Theory of Visual Attention without the race: a new model of visual selection

    DEFF Research Database (Denmark)

    Andersen, Tobias; Kyllingsbæk, Søren

    2012-01-01

    constrained by a limited processing capacity or rate, which is distributed among target and distractor objects with distractor objects receiving a smaller proportion of resources due to attentional filtering. Encoding into a limited visual short-term memory is implemented as a race model. Given its major...

  19. Selective visual attention to emotional words: Early parallel frontal and visual activations followed by interactive effects in visual cortex.

    Science.gov (United States)

    Schindler, Sebastian; Kissler, Johanna

    2016-10-01

    Human brains spontaneously differentiate between various emotional and neutral stimuli, including written words whose emotional quality is symbolic. In the electroencephalogram (EEG), emotional-neutral processing differences are typically reflected in the early posterior negativity (EPN, 200-300 ms) and the late positive potential (LPP, 400-700 ms). These components are also enlarged by task-driven visual attention, supporting the assumption that emotional content naturally drives attention. Still, the spatio-temporal dynamics of interactions between emotional stimulus content and task-driven attention remain to be specified. Here, we examine this issue in visual word processing. Participants attended to negative, neutral, or positive nouns while high-density EEG was recorded. Emotional content and top-down attention both amplified the EPN component in parallel. On the LPP, by contrast, emotion and attention interacted: Explicit attention to emotional words led to a substantially larger amplitude increase than did explicit attention to neutral words. Source analysis revealed early parallel effects of emotion and attention in bilateral visual cortex and a later interaction of both in right visual cortex. Distinct effects of attention were found in inferior, middle and superior frontal, paracentral, and parietal areas, as well as in the anterior cingulate cortex (ACC). Results specify separate and shared mechanisms of emotion and attention at distinct processing stages. Hum Brain Mapp 37:3575-3587, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. PC-based visualization of geographically referenced environmental data

    International Nuclear Information System (INIS)

    Galagan, C.; Howlett, E. Brown, A.J.

    1992-01-01

    Geographical information system (GIS) technology provides sophisticated data handling tools for use in oil spill response and contingency planning. ASAMAP is a software that employs a state-of-the-art graphical user interface to collect and display geographically referenced data on a personal computer. The program is easy to learn and simple to operate, facilitating data collection and visualization in an inexpensive decision support system suitable for oil spill response or any application requiring special data handling. The software can operate on a laptop computer for convenient use in the field and is mouse-driven, using buttons and screen icons to manipulate data interactively on color maps on the screen. During response to an oil spill, ASAMAP provides enhanced data capture and visualization, facilitating faster assimilation of information and a more efficient decision making process. 8 refs., 1 fig

  1. Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

    Science.gov (United States)

    Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

    2017-09-13

    GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

  2. Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size

    Science.gov (United States)

    Andersen, Lau Møller; Blicher, Jakob Udby

    2017-01-01

    GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

  3. WATERSHED SELECTION FOR ENVIRONMENTAL REHABILITATION USING MULTICRITERIA ANALYSIS

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silva Francisco

    2009-10-01

    Full Text Available The Anhumas creek watershed, in the region of Campinas, São Paulo State, Brazil, is degraded also as a result of unplanned land use of its riparian zones, considered Permanent Preservation Areas (APP. Therefore, river flow is unstable, promoting frequent flood damages, besides the lack of several environmental functions of its APPs. Environmental recovery of a degraded area requires a comprehensive effort, often multidisciplinary. Multicriterial analysis is a tool which allows gathering a diversity of attributes of the studied subject, weighing and valuating them, helping in the decision making effort. This work aims to apply two methods of multicriteria analysis to optimize the selection of a watershed for an environmental recovery study of APPs in the Anhumas watershed. The Anhumas watershed was divided in 7 sub-basins aiming the selection of one of those to implement an environmental planning study and to establish and rank areas that should be prioritized for recovery. Thirteen environmental criteria were selected for application of multicriteria analysis using the methods of Compromise Programming (PC and Cooperative Game Theory (CGT. Relevance of each criterion to the analysis was given by a questionnaire answered by specialists. Basin selection results showed no difference neither between PC and CGT nor between mean or mode used to standardize weights given by specialists. Multicriteria analysis was effective, but allowed enough flexibility for the decision maker (DM to adjust undesired analysis distortions. After DM adjustments, the priority basins were ranked as basins 4 > 7 > 5 > 6 > 2 > 3 > 1. Important procedures when carrying out such an analysis were to avoid conceptual overlapping among different criteria, to implement appropriate value judgment for each criterion and to use decision maker expertise to supplement weights obtained with specialists.

  4. Simulating the role of visual selective attention during the development of perceptual completion

    OpenAIRE

    Schlesinger, Matthew; Amso, Dima; Johnson, Scott P.

    2012-01-01

    We recently proposed a multi-channel, image-filtering model for simulating the development of visual selective attention in young infants (Schlesinger, Amso & Johnson, 2007). The model not only captures the performance of 3-month-olds on a visual search task, but also implicates two cortical regions that may play a role in the development of visual selective attention. In the current simulation study, we used the same model to simulate 3-month-olds’ performance on a second measure, the percep...

  5. Directed forgetting of visual symbols: evidence for nonverbal selective rehearsal.

    Science.gov (United States)

    Hourihan, Kathleen L; Ozubko, Jason D; MacLeod, Colin M

    2009-12-01

    Is selective rehearsal possible for nonverbal information? Two experiments addressed this question using the item method directed forgetting paradigm, where the advantage of remember items over forget items is ascribed to selective rehearsal favoring the remember items. In both experiments, difficult-to-name abstract symbols were presented for study, followed by a recognition test. Directed forgetting effects were evident for these symbols, regardless of whether they were or were not spontaneously named. Critically, a directed forgetting effect was observed for unnamed symbols even when the symbols were studied under verbal suppression to prevent verbal rehearsal. This pattern indicates that a form of nonverbal rehearsal can be used strategically (i.e., selectively) to enhance memory, even when verbal rehearsal is not possible.

  6. Enhancing Auditory Selective Attention Using a Visually Guided Hearing Aid

    Science.gov (United States)

    Kidd, Gerald, Jr.

    2017-01-01

    Purpose: Listeners with hearing loss, as well as many listeners with clinically normal hearing, often experience great difficulty segregating talkers in a multiple-talker sound field and selectively attending to the desired "target" talker while ignoring the speech from unwanted "masker" talkers and other sources of sound. This…

  7. Spatial Scaling of the Profile of Selective Attention in the Visual Field.

    Science.gov (United States)

    Gannon, Matthew A; Knapp, Ashley A; Adams, Thomas G; Long, Stephanie M; Parks, Nathan A

    2016-01-01

    Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs) to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load) and visual angle (1.0° or 2.5°). Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

  8. Spatial Scaling of the Profile of Selective Attention in the Visual Field.

    Directory of Open Access Journals (Sweden)

    Matthew A Gannon

    Full Text Available Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load and visual angle (1.0° or 2.5°. Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

  9. Early environmental planning: A process for power line corridor selection

    International Nuclear Information System (INIS)

    Haagenstad, T.; Bare, C.M.

    1998-01-01

    Los Alamos National Laboratory (LANL) conducted an environmental planning study in the fall of 1997 to help determine the best alternative for upgrading the Laboratory's electrical power system. Alternatives considered included an on-site power generation facility and two corridors for a 10-mile-long 115-kV power line. This planning process was conducted prior to the formal National Environmental Policy Act (NEPA) review. The goals were to help select the best proposed action, to recommend modifications and mitigation measures for each alternative for a more environmentally sound project, and to avoid potential delays once the formal Department of Energy review process began. Significant constraints existed from a planning perspective, including operational issues such as existing outdoor high explosives testing areas, as well as environmental issues including threatened and endangered species habitats, multiple archeological sites, contaminated areas, and aesthetics. The study had to be completed within 45 days to meet project schedule needs. The process resulted in a number of important recommendations. While the construction and operation of the on-site power generation facility could have minimal environmental impacts, the need for a new air quality permit would create severe cost and schedule constraints for the project. From an environmental perspective, construction and operation of a power line within either corridor was concluded to be a viable alternative. However, impacts with either corridor would have to be reduced through specific recommended alignment modifications and mitigation measures

  10. Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

    Science.gov (United States)

    Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

    2013-10-16

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

  11. Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

    Science.gov (United States)

    Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

    2013-01-01

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

  12. Sex-specific selection under environmental stress in seed beetles.

    Science.gov (United States)

    Martinossi-Allibert, I; Arnqvist, G; Berger, D

    2017-01-01

    Sexual selection can increase rates of adaptation by imposing strong selection in males, thereby allowing efficient purging of the mutation load on population fitness at a low demographic cost. Indeed, sexual selection tends to be male-biased throughout the animal kingdom, but little empirical work has explored the ecological sensitivity of this sex difference. In this study, we generated theoretical predictions of sex-specific strengths of selection, environmental sensitivities and genotype-by-environment interactions and tested them in seed beetles by manipulating either larval host plant or rearing temperature. Using fourteen isofemale lines, we measured sex-specific reductions in fitness components, genotype-by-environment interactions and the strength of selection (variance in fitness) in the juvenile and adult stage. As predicted, variance in fitness increased with stress, was consistently greater in males than females for adult reproductive success (implying strong sexual selection), but was similar in the sexes in terms of juvenile survival across all levels of stress. Although genetic variance in fitness increased in magnitude under severe stress, heritability decreased and particularly so in males. Moreover, genotype-by-environment interactions for fitness were common but specific to the type of stress, sex and life stage, suggesting that new environments may change the relative alignment and strength of selection in males and females. Our study thus exemplifies how environmental stress can influence the relative forces of natural and sexual selection, as well as concomitant changes in genetic variance in fitness, which are predicted to have consequences for rates of adaptation in sexual populations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  13. Visualizing the Anthropocene: Human Land Use History and Environmental Management

    Science.gov (United States)

    Richard D. Periman

    2006-01-01

    The term “Anthropocene” defines the current, human-dominated, geological epoch of human-caused environmental influences. Some researchers believe that the beginning of this epoch coincides with the inception of the Industrial Revolution (Crutzen and Stoermer 2000). Research is revealing that humans have affected environments on global and local scales for millennia....

  14. Environmental Linguistics: A Typology of Visual Factors in Shopping Malls.

    Science.gov (United States)

    Woods, John D.; Sewell, Edward H., Jr.

    Environment may be regarded as a form of communication, with environmental linguistics becoming a new discipline that will have to be explored. Its goal is to demystify some of the constructs that contribute to the built environment as a communication tool. Treating the built environment as a language requires a recognition of its dynamic nature.…

  15. Biological monitoring and selected trends in environmental quality

    International Nuclear Information System (INIS)

    Suffern, J.S.; West, D.C.; Kemp, H.T.; Burgess, R.L.

    1976-10-01

    Under a contract with the President's Council on Environmental Quality, the National Inventory of Selected Biological Monitoring Programs at ORNL was used to identify documented environmental trends. Fish population trends were described for the Great Lakes and the Colorado River system. Trends in amphibian populations in the northeast were examined and correlated with acid precipitation. Increases in breeding success among large birds of prey were correlated with reductions in ambient levels of DDT and its residues. Geographic variation in PCB contamination was examined along with differences between aquatic and terrestrial contamination levels. Changes in air quality were documented, and their effects on plant viability were outlined. Trends in the biological effects of environmental deposition of lead were documented. Long-term changes in forest structure in the southeast were presented, and a general reduction in wildlife habitat, associated with land use practices, was documented for several areas in the US

  16. Vegetarianism and food perception : selective visual attention to meat pictures

    OpenAIRE

    Stockburger, Jessica; Renner, Britta; Weike, Almut I.; Hamm, Alfons O.; Schupp, Harald Thomas

    2009-01-01

    Vegetarianism provides a model system to examine the impact of negative affect towards meat, based on ideational reasoning. It was hypothesized that meat stimuli are efficient attention catchers in vegetarians. Event-related brain potential recordings served to index selective attention processes at the level of initial stimulus perception. Consistent with the hypothesis, late positive potentials to meat pictures were enlarged in vegetarians compared to omnivores. This effect was specific fo...

  17. Selective attention modulates the direction of audio-visual temporal recalibration.

    Science.gov (United States)

    Ikumi, Nara; Soto-Faraco, Salvador

    2014-01-01

    Temporal recalibration of cross-modal synchrony has been proposed as a mechanism to compensate for timing differences between sensory modalities. However, far from the rich complexity of everyday life sensory environments, most studies to date have examined recalibration on isolated cross-modal pairings. Here, we hypothesize that selective attention might provide an effective filter to help resolve which stimuli are selected when multiple events compete for recalibration. We addressed this question by testing audio-visual recalibration following an adaptation phase where two opposing audio-visual asynchronies were present. The direction of voluntary visual attention, and therefore to one of the two possible asynchronies (flash leading or flash lagging), was manipulated using colour as a selection criterion. We found a shift in the point of subjective audio-visual simultaneity as a function of whether the observer had focused attention to audio-then-flash or to flash-then-audio groupings during the adaptation phase. A baseline adaptation condition revealed that this effect of endogenous attention was only effective toward the lagging flash. This hints at the role of exogenous capture and/or additional endogenous effects producing an asymmetry toward the leading flash. We conclude that selective attention helps promote selected audio-visual pairings to be combined and subsequently adjusted in time but, stimulus organization exerts a strong impact on recalibration. We tentatively hypothesize that the resolution of recalibration in complex scenarios involves the orchestration of top-down selection mechanisms and stimulus-driven processes.

  18. Selective attention modulates the direction of audio-visual temporal recalibration.

    Directory of Open Access Journals (Sweden)

    Nara Ikumi

    Full Text Available Temporal recalibration of cross-modal synchrony has been proposed as a mechanism to compensate for timing differences between sensory modalities. However, far from the rich complexity of everyday life sensory environments, most studies to date have examined recalibration on isolated cross-modal pairings. Here, we hypothesize that selective attention might provide an effective filter to help resolve which stimuli are selected when multiple events compete for recalibration. We addressed this question by testing audio-visual recalibration following an adaptation phase where two opposing audio-visual asynchronies were present. The direction of voluntary visual attention, and therefore to one of the two possible asynchronies (flash leading or flash lagging, was manipulated using colour as a selection criterion. We found a shift in the point of subjective audio-visual simultaneity as a function of whether the observer had focused attention to audio-then-flash or to flash-then-audio groupings during the adaptation phase. A baseline adaptation condition revealed that this effect of endogenous attention was only effective toward the lagging flash. This hints at the role of exogenous capture and/or additional endogenous effects producing an asymmetry toward the leading flash. We conclude that selective attention helps promote selected audio-visual pairings to be combined and subsequently adjusted in time but, stimulus organization exerts a strong impact on recalibration. We tentatively hypothesize that the resolution of recalibration in complex scenarios involves the orchestration of top-down selection mechanisms and stimulus-driven processes.

  19. Event-related potentials during visual selective attention in children of alcoholics.

    NARCIS (Netherlands)

    van der Stelt, O.; Gunning, W.B.; Snel, J.; Kok, A.

    1998-01-01

    Event-related potentials (ERPs) were recorded from 50 7-18 yr old children of alcoholics (COAs) and 50 age- and sex-matched control children while they performed a visual selective attention task. The task was to attend selectively to stimuli with a specified color (red or blue) in an attempt to

  20. Vegetarianism and food perception. Selective visual attention to meat pictures.

    Science.gov (United States)

    Stockburger, Jessica; Renner, Britta; Weike, Almut I; Hamm, Alfons O; Schupp, Harald T

    2009-04-01

    Vegetarianism provides a model system to examine the impact of negative affect towards meat, based on ideational reasoning. It was hypothesized that meat stimuli are efficient attention catchers in vegetarians. Event-related brain potential recordings served to index selective attention processes at the level of initial stimulus perception. Consistent with the hypothesis, late positive potentials to meat pictures were enlarged in vegetarians compared to omnivores. This effect was specific for meat pictures and obtained during passive viewing and an explicit attention task condition. These findings demonstrate the attention capture of food stimuli, deriving affective salience from ideational reasoning and symbolic meaning.

  1. Modeling the effect of selection history on pop-out visual search.

    Directory of Open Access Journals (Sweden)

    Yuan-Chi Tseng

    Full Text Available While attentional effects in visual selection tasks have traditionally been assigned "top-down" or "bottom-up" origins, more recently it has been proposed that there are three major factors affecting visual selection: (1 physical salience, (2 current goals and (3 selection history. Here, we look further into selection history by investigating Priming of Pop-out (POP and the Distractor Preview Effect (DPE, two inter-trial effects that demonstrate the influence of recent history on visual search performance. Using the Ratcliff diffusion model, we model observed saccadic selections from an oddball search experiment that included a mix of both POP and DPE conditions. We find that the Ratcliff diffusion model can effectively model the manner in which selection history affects current attentional control in visual inter-trial effects. The model evidence shows that bias regarding the current trial's most likely target color is the most critical parameter underlying the effect of selection history. Our results are consistent with the view that the 3-item color-oddball task used for POP and DPE experiments is best understood as an attentional decision making task.

  2. Multiple-view, Multiple-selection Visualization of Simulation Geometry in CMS

    International Nuclear Information System (INIS)

    Bauerdick, L A T; Eulisse, G; Jones, C; McCauley, T; Osborne, I; Kovalskyi, D; Mrak Tadel, A; Tadel, M; Yagil, A

    2012-01-01

    Fireworks, the event-display program of CMS, was extended with an advanced geometry visualization package. ROOT's TGeo geometry is used as internal representation, shared among several geometry views. Each view is represented by a GUI list-tree widget, implemented as a flat vector to allow for fast searching, selection, and filtering by material type, node name, and shape type. Display of logical and physical volumes is supported. Color, transparency, and visibility flags can be modified for each node or for a selection of nodes. Further operations, like opening of a new view or changing of the root node, can be performed via a context menu. Node selection and graphical properties determined by the list-tree view can be visualized in any 3D graphics view of Fireworks. As each 3D view can display any number of geometry views, a user is free to combine different geometry-view selections within the same 3D view. Node-selection by proximity to a given point is possible. A visual clipping box can be set for each geometry view to limit geometry drawing into a specified region. Visualization of geometric overlaps, as detected by TGeo, is also supported. The geometry visualization package is used for detailed inspection and display of simulation geometry with or without the event data. It also serves as a tool for geometry debugging and inspection, facilitating development of geometries for CMS detector upgrades and for SLHC.

  3. A model of selective visual attention for a stereo pair of images

    Science.gov (United States)

    Park, Min Chul; Kim, Sung Kyu; Son, Jung-Young

    2005-11-01

    Human visual attention system has a remarkable ability to interpret complex scenes with the ease and simplicity by selecting or focusing on a small region of visual field without scanning the whole images. In this paper, a novel selective visual attention model by using 3D image display system for a stereo pair of images is proposed. It is based on the feature integration theory and locates ROI(region of interest) or FOA(focus of attention). The disparity map obtained from a stereo pair of images is exploited as one of spatial visual features to form a set of topographic feature maps in our approach. Though the true human cognitive mechanism on the analysis and integration process might be different from our assumption the proposed attention system matches well with the results found by human observers.

  4. The selective processing of emotional visual stimuli while detecting auditory targets : An ERP analysis

    OpenAIRE

    Schupp, Harald Thomas; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I.; Hamm, Alfons O.

    2008-01-01

    Event-related potential studies revealed an early posterior negativity (EPN) for emotional compared to neutral pictures. Exploring the emotion-attention relationship, a previous study observed that a primary visual discrimination task interfered with the emotional modulation of the EPN component. To specify the locus of interference, the present study assessed the fate of selective visual emotion processing while attention is directed towards the auditory modality. While simply viewing a rapi...

  5. The spatially global control of attentional target selection in visual search

    OpenAIRE

    Berggren, Nick; Jenkins, M.; McCants, C.W.; Eimer, Martin

    2017-01-01

    Glyn Humphreys and his co-workers have made numerous important theoretical and empirical contributions to research on visual search. They have introduced the concept of attentional target templates and investigated the nature of these templates and how they are involved in the control of search performance. In the experiments reported here, we investigated whether feature-specific search template for particular colours can guide target selection independently for different regions of visual s...

  6. Different cortical mechanisms for spatial vs. feature-based attentional selection in visual working memory

    Directory of Open Access Journals (Sweden)

    Anna Heuer

    2016-08-01

    Full Text Available The limited capacity of visual working memory necessitates attentional mechanisms that selectively update and maintain only the most task-relevant content. Psychophysical experiments have shown that the retroactive selection of memory content can be based on visual properties such as location or shape, but the neural basis for such differential selection is unknown. For example, it is not known if there are different cortical modules specialized for spatial versus feature-based mnemonic attention, in the same way that has been demonstrated for attention to perceptual input. Here, we used transcranial magnetic stimulation (TMS to identify areas in human parietal and occipital cortex involved in the selection of objects from memory based on cues to their location (spatial information or their shape (featural information. We found that TMS over the supramarginal gyrus (SMG selectively facilitated spatial selection, whereas TMS over the lateral occipital cortex selectively enhanced feature-based selection for remembered objects in the contralateral visual field. Thus, different cortical regions are responsible for spatial vs. feature-based selection of working memory representations. Since the same regions are involved in attention to external events, these new findings indicate overlapping mechanisms for attentional control over perceptual input and mnemonic representations.

  7. Electrophysiological evidence for altered visual, but not auditory, selective attention in adolescent cochlear implant users.

    Science.gov (United States)

    Harris, Jill; Kamke, Marc R

    2014-11-01

    Selective attention fundamentally alters sensory perception, but little is known about the functioning of attention in individuals who use a cochlear implant. This study aimed to investigate visual and auditory attention in adolescent cochlear implant users. Event related potentials were used to investigate the influence of attention on visual and auditory evoked potentials in six cochlear implant users and age-matched normally-hearing children. Participants were presented with streams of alternating visual and auditory stimuli in an oddball paradigm: each modality contained frequently presented 'standard' and infrequent 'deviant' stimuli. Across different blocks attention was directed to either the visual or auditory modality. For the visual stimuli attention boosted the early N1 potential, but this effect was larger for cochlear implant users. Attention was also associated with a later P3 component for the visual deviant stimulus, but there was no difference between groups in the later attention effects. For the auditory stimuli, attention was associated with a decrease in N1 latency as well as a robust P3 for the deviant tone. Importantly, there was no difference between groups in these auditory attention effects. The results suggest that basic mechanisms of auditory attention are largely normal in children who are proficient cochlear implant users, but that visual attention may be altered. Ultimately, a better understanding of how selective attention influences sensory perception in cochlear implant users will be important for optimising habilitation strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Selective attention modulates visual and haptic repetition priming: effects in aging and Alzheimer's disease.

    Science.gov (United States)

    Ballesteros, Soledad; Reales, José M; Mayas, Julia; Heller, Morton A

    2008-08-01

    In two experiments, we examined the effect of selective attention at encoding on repetition priming in normal aging and Alzheimer's disease (AD) patients for objects presented visually (experiment 1) or haptically (experiment 2). We used a repetition priming paradigm combined with a selective attention procedure at encoding. Reliable priming was found for both young adults and healthy older participants for visually presented pictures (experiment 1) as well as for haptically presented objects (experiment 2). However, this was only found for attended and not for unattended stimuli. The results suggest that independently of the perceptual modality, repetition priming requires attention at encoding and that perceptual facilitation is maintained in normal aging. However, AD patients did not show priming for attended stimuli, or for unattended visual or haptic objects. These findings suggest an early deficit of selective attention in AD. Results are discussed from a cognitive neuroscience approach.

  9. Riel Converter Station, Winnipeg: Site selection and environmental assessment status report

    International Nuclear Information System (INIS)

    1991-01-01

    As part of its expansion plans, Manitoba Hydro is planning to construct a converter station east of Winnipeg to receive power from a 850-km dc transmission line which will be constructed to bring power from a new generating station in the north of the province. Work performed to date on site selection and preliminary environmental assessment of the converter station is reviewed. The role of the converter station is described and the potential impacts are summarized in such areas as employment opportunities, pollution and noise during construction, electric and magnetic field effects, and land use impacts. Site selection criteria are outlined and potential sites are identified and evaluated. The Deacon site has been chosen as the preferred site since it has a number of inherent advantages including existing ownership by Manitoba Hydro, proximity to existing transmission rights-of-way, and low visual and land-use impact. 12 figs

  10. Environmental and economical aspects of selected energy system

    International Nuclear Information System (INIS)

    1991-11-01

    An analysis of environmental and economical aspects of selected renewable energy systems is presented. The aim was to provide a basis for estimating the competitive status in each case, to review the consequences of technological development, to identify attractive markets and to evaluate the effects of various economic conditions. Calculation methods are described and individual solar heating systems are compared to oil-fired boilers, boilers fired with solid fuels are compared to oil-fired boilers and straw-fired cogeneration plants are compared with coal, fuel-oil and straw-fired district heating plants. Results are presented in the form of tables and graphs. (AB)

  11. Category-specific visual responses: an intracranial study comparing gamma, beta, alpha and ERP response selectivity

    Directory of Open Access Journals (Sweden)

    Juan R Vidal

    2010-11-01

    Full Text Available The specificity of neural responses to visual objects is a major topic in visual neuroscience. In humans, functional magnetic resonance imaging (fMRI studies have identified several regions of the occipital and temporal lobe that appear specific to faces, letter-strings, scenes, or tools. Direct electrophysiological recordings in the visual cortical areas of epileptic patients have largely confirmed this modular organization, using either single-neuron peri-stimulus time-histogram or intracerebral event-related potentials (iERP. In parallel, a new research stream has emerged using high-frequency gamma-band activity (50-150 Hz (GBR and low-frequency alpha/beta activity (8-24 Hz (ABR to map functional networks in humans. An obvious question is now whether the functional organization of the visual cortex revealed by fMRI, ERP, GBR, and ABR coincide. We used direct intracerebral recordings in 18 epileptic patients to directly compare GBR, ABR, and ERP elicited by the presentation of seven major visual object categories (faces, scenes, houses, consonants, pseudowords, tools, and animals, in relation to previous fMRI studies. Remarkably both GBR and iERP showed strong category-specificity that was in many cases sufficient to infer stimulus object category from the neural response at single-trial level. However, we also found a strong discrepancy between the selectivity of GBR, ABR, and ERP with less than 10% of spatial overlap between sites eliciting the same category-specificity. Overall, we found that selective neural responses to visual objects were broadly distributed in the brain with a prominent spatial cluster located in the posterior temporal cortex. Moreover, the different neural markers (GBR, ABR, and iERP that elicit selectivity towards specific visual object categories present little spatial overlap suggesting that the information content of each marker can uniquely characterize high-level visual information in the brain.

  12. Orientation selectivity of synaptic input to neurons in mouse and cat primary visual cortex.

    Science.gov (United States)

    Tan, Andrew Y Y; Brown, Brandon D; Scholl, Benjamin; Mohanty, Deepankar; Priebe, Nicholas J

    2011-08-24

    Primary visual cortex (V1) is the site at which orientation selectivity emerges in mammals: visual thalamus afferents to V1 respond equally to all stimulus orientations, whereas their target V1 neurons respond selectively to stimulus orientation. The emergence of orientation selectivity in V1 has long served as a model for investigating cortical computation. Recent evidence for orientation selectivity in mouse V1 opens cortical computation to dissection by genetic and imaging tools, but also raises two essential questions: (1) How does orientation selectivity in mouse V1 neurons compare with that in previously described species? (2) What is the synaptic basis for orientation selectivity in mouse V1? A comparison of orientation selectivity in mouse and in cat, where such measures have traditionally been made, reveals that orientation selectivity in mouse V1 is weaker than in cat V1, but that spike threshold plays a similar role in narrowing selectivity between membrane potential and spike rate. To uncover the synaptic basis for orientation selectivity, we made whole-cell recordings in vivo from mouse V1 neurons, comparing neuronal input selectivity-based on membrane potential, synaptic excitation, and synaptic inhibition-to output selectivity based on spiking. We found that a neuron's excitatory and inhibitory inputs are selective for the same stimulus orientations as is its membrane potential response, and that inhibitory selectivity is not broader than excitatory selectivity. Inhibition has different dynamics than excitation, adapting more rapidly. In neurons with temporally modulated responses, the timing of excitation and inhibition was different in mice and cats.

  13. Top down and bottom up selection drives variations in frequency and form of a visual signal

    OpenAIRE

    Yeh, Chien-Wei; Blamires, Sean J.; Liao, Chen-Pan; Tso, I.-Min

    2015-01-01

    The frequency and form of visual signals can be shaped by selection from predators, prey or both. When a signal simultaneously attracts predators and prey, selection may favour a strategy that minimizes risks while attracting prey. Accordingly, varying the frequency and form of the silken decorations added to their web may be a way that Argiope spiders minimize predation while attracting prey. Nonetheless, the role of extraneous factors renders the influences of top down and bottom up selecti...

  14. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

    OpenAIRE

    Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnove; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

    2015-01-01

    Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dua...

  15. Exploring Visual Selective Attention towards Novel Stimuli in Alzheimer's Disease Patients

    OpenAIRE

    Sarah A. Chau; Nathan Herrmann; Moshe Eizenman; Jonathan Chung; Krista L. Lanctôt

    2015-01-01

    Background: Alzheimer's disease (AD) is associated with selective attention impairments, which could contribute to cognitive and functional deficits. Selective attention can be explored through examination of novelty preference. Aims: In this study, we quantified novelty preference in AD patients by measuring visual scanning behaviour using an eye tracking paradigm. Methods: Mild-to-moderate AD patients and elderly controls viewed slides containing novel and repeated images simultaneously. Th...

  16. The selective processing of emotional visual stimuli while detecting auditory targets: an ERP analysis.

    Science.gov (United States)

    Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

    2008-09-16

    Event-related potential studies revealed an early posterior negativity (EPN) for emotional compared to neutral pictures. Exploring the emotion-attention relationship, a previous study observed that a primary visual discrimination task interfered with the emotional modulation of the EPN component. To specify the locus of interference, the present study assessed the fate of selective visual emotion processing while attention is directed towards the auditory modality. While simply viewing a rapid and continuous stream of pleasant, neutral, and unpleasant pictures in one experimental condition, processing demands of a concurrent auditory target discrimination task were systematically varied in three further experimental conditions. Participants successfully performed the auditory task as revealed by behavioral performance and selected event-related potential components. Replicating previous results, emotional pictures were associated with a larger posterior negativity compared to neutral pictures. Of main interest, increasing demands of the auditory task did not modulate the selective processing of emotional visual stimuli. With regard to the locus of interference, selective emotion processing as indexed by the EPN does not seem to reflect shared processing resources of visual and auditory modality.

  17. Specific and Nonspecific Neural Activity during Selective Processing of Visual Representations in Working Memory

    Science.gov (United States)

    Oh, Hwamee; Leung, Hoi-Chung

    2010-01-01

    In this fMRI study, we investigated prefrontal cortex (PFC) and visual association regions during selective information processing. We recorded behavioral responses and neural activity during a delayed recognition task with a cue presented during the delay period. A specific cue ("Face" or "Scene") was used to indicate which one of the two…

  18. Body-selective areas in the visual cortex are less active in children than in adults

    NARCIS (Netherlands)

    Ross, Paddy D.; de Gelder, Beatrice; Crabbe, Frances; Grosbras, Marie-Helene

    2014-01-01

    Our ability to read other people's non-verbal signals gets refined throughout childhood and adolescence. How this is paralleled by brain development has been investigated mainly with regards to face perception, showing a protracted functional development of the face-selective visual cortical areas.

  19. Event-related potentials during visual selective attention in children of alcoholics.

    Science.gov (United States)

    van der Stelt, O; Gunning, W B; Snel, J; Kok, A

    1998-12-01

    Event-related potentials were recorded from 7- to 18-year-old children of alcoholics (COAs, n = 50) and age- and sex-matched control children (n = 50) while they performed a visual selective attention task. The task was to attend selectively to stimuli with a specified color (red or blue) in an attempt to detect the occurrence of target stimuli. COAs manifested a smaller P3b amplitude to attended-target stimuli over the parietal and occipital scalp than did the controls. A more specific analysis indicated that both the attentional relevance and the target properties of the eliciting stimulus determined the observed P3b amplitude differences between COAs and controls. In contrast, no significant group differences were observed in attention-related earlier occurring event-related potential components, referred to as frontal selection positivity, selection negativity, and N2b. These results represent neurophysiological evidence that COAs suffer from deficits at a late (semantic) level of visual selective information processing that are unlikely a consequence of deficits at earlier (sensory) levels of selective processing. The findings support the notion that a reduced visual P3b amplitude in COAs represents a high-level processing dysfunction indicating their increased vulnerability to alcoholism.

  20. Acute exercise and aerobic fitness influence selective attention during visual search.

    Science.gov (United States)

    Bullock, Tom; Giesbrecht, Barry

    2014-01-01

    Successful goal directed behavior relies on a human attention system that is flexible and able to adapt to different conditions of physiological stress. However, the effects of physical activity on multiple aspects of selective attention and whether these effects are mediated by aerobic capacity, remains unclear. The aim of the present study was to investigate the effects of a prolonged bout of physical activity on visual search performance and perceptual distraction. Two groups of participants completed a hybrid visual search flanker/response competition task in an initial baseline session and then at 17-min intervals over a 2 h 16 min test period. Participants assigned to the exercise group engaged in steady-state aerobic exercise between completing blocks of the visual task, whereas participants assigned to the control group rested in between blocks. The key result was a correlation between individual differences in aerobic capacity and visual search performance, such that those individuals that were more fit performed the search task more quickly. Critically, this relationship only emerged in the exercise group after the physical activity had begun. The relationship was not present in either group at baseline and never emerged in the control group during the test period, suggesting that under these task demands, aerobic capacity may be an important determinant of visual search performance under physical stress. The results enhance current understanding about the relationship between exercise and cognition, and also inform current models of selective attention.

  1. Acute exercise and aerobic fitness influence selective attention during visual search

    Science.gov (United States)

    Bullock, Tom; Giesbrecht, Barry

    2014-01-01

    Successful goal directed behavior relies on a human attention system that is flexible and able to adapt to different conditions of physiological stress. However, the effects of physical activity on multiple aspects of selective attention and whether these effects are mediated by aerobic capacity, remains unclear. The aim of the present study was to investigate the effects of a prolonged bout of physical activity on visual search performance and perceptual distraction. Two groups of participants completed a hybrid visual search flanker/response competition task in an initial baseline session and then at 17-min intervals over a 2 h 16 min test period. Participants assigned to the exercise group engaged in steady-state aerobic exercise between completing blocks of the visual task, whereas participants assigned to the control group rested in between blocks. The key result was a correlation between individual differences in aerobic capacity and visual search performance, such that those individuals that were more fit performed the search task more quickly. Critically, this relationship only emerged in the exercise group after the physical activity had begun. The relationship was not present in either group at baseline and never emerged in the control group during the test period, suggesting that under these task demands, aerobic capacity may be an important determinant of visual search performance under physical stress. The results enhance current understanding about the relationship between exercise and cognition, and also inform current models of selective attention. PMID:25426094

  2. An investigation of visual selection priority of objects with texture and crossed and uncrossed disparities

    Science.gov (United States)

    Khaustova, Dar'ya; Fournier, Jérôme; Wyckens, Emmanuel; Le Meur, Olivier

    2014-02-01

    The aim of this research is to understand the difference in visual attention to 2D and 3D content depending on texture and amount of depth. Two experiments were conducted using an eye-tracker and a 3DTV display. Collected fixation data were used to build saliency maps and to analyze the differences between 2D and 3D conditions. In the first experiment 51 observers participated in the test. Using scenes that contained objects with crossed disparity, it was discovered that such objects are the most salient, even if observers experience discomfort due to the high level of disparity. The goal of the second experiment is to decide whether depth is a determinative factor for visual attention. During the experiment, 28 observers watched the scenes that contained objects with crossed and uncrossed disparities. We evaluated features influencing the saliency of the objects in stereoscopic conditions by using contents with low-level visual features. With univariate tests of significance (MANOVA), it was detected that texture is more important than depth for selection of objects. Objects with crossed disparity are significantly more important for selection processes when compared to 2D. However, objects with uncrossed disparity have the same influence on visual attention as 2D objects. Analysis of eyemovements indicated that there is no difference in saccade length. Fixation durations were significantly higher in stereoscopic conditions for low-level stimuli than in 2D. We believe that these experiments can help to refine existing models of visual attention for 3D content.

  3. Acute exercise and aerobic fitness influence selective attention during visual search

    Directory of Open Access Journals (Sweden)

    Tom eBullock

    2014-11-01

    Full Text Available Successful goal directed behavior relies on a human attention system that is flexible and able to adapt to different conditions of physiological stress. However, the effects of physical activity on multiple aspects of selective attention and whether these effects are mediated by aerobic capacity, remains unclear. The aim of the present study was to investigate the effects of a prolonged bout of physical activity on visual search performance and perceptual distraction. Two groups of participants completed a hybrid visual search flanker/response competition task in an initial baseline session and then at 17-minute intervals over a 2 hour 16 minute test period. Participants assigned to the exercise group engaged in steady-state aerobic exercise between completing blocks of the visual task, whereas participants assigned to the control group rested in between blocks. The key result was a correlation between individual differences in aerobic capacity and visual search performance, such that those individuals that were more fit performed the search task more quickly. Critically, this relationship only emerged in the exercise group after the physical activity had begun. The relationship was not present in either group at baseline and never emerged in the control group during the test period, suggesting that under these task demands, aerobic capacity may be an important determinant of visual search performance under physical stress. The results enhance current understanding about the relationship between exercise and cognition, and also inform current models of selective attention.

  4. Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways.

    Science.gov (United States)

    Jiang, Like; Kang, Jian

    2016-02-01

    This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5m timber barrier, and 5m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5m timber barrier tended to perform better than the 3m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Multiple-view, multiple-selection visualization of simulation geometry in CMS

    CERN Document Server

    Mrak Tadel, Alja

    2012-01-01

    Fireworks, the event-display program of CMS, was extended with an advanced geometry visualization package. ROOT's TGeo geometry is used as internal representation, shared among several geometry views. Each view is represented by a GUI list-tree widget, implemented as a flat vector to allow for fast searching, selection, and filtering by material type, node name, and shape type. Display of logical and physical volumes is supported. Color, transparency, and visibility flags can be modified for each node or for a selection of nodes. Further operations, like opening of a new view or changing of the root node, can be performed via a context menu. Node selection and graphical properties determined by the list-tree view can be visualized in any 3D graphics view of Fireworks. As each 3D view can display any number of geometry views, a user is free to combine different geometry-view selections within the same 3D view. Node-selection by proximity to a given point is possible. A visual clipping box can be set for each g...

  6. Weak surround suppression of the attentional focus characterizes visual selection in the ventral stream in autism

    Directory of Open Access Journals (Sweden)

    Luca Ronconi

    Full Text Available Neurophysiological findings in the typical population demonstrate that spatial scrutiny for visual selection determines a center-surround profile of the attentional focus, which is the result of recurrent processing in the visual system. Individuals with autism spectrum disorder (ASD manifest several anomalies in their visual selection, with strengths in detail-oriented tasks, but also difficulties in distractor inhibition tasks. Here, we asked whether contradictory aspects of perception in ASD might be due to a different center-surround profile of their attentional focus. In two experiments, we tested two independent samples of children with ASD, comparing them with typically developing (TD peers. In Experiment 1, we used a psychophysical task that mapped the entire spatial profile of the attentional focus. In Experiment 2, we used dense-array electroencephalography (EEG to explore its neurophysiological underpinnings. Experiment 1 results showed that the suppression, surrounding the attentional focus, was markedly reduced in children with ASD. Experiment 2 showed that the center-surround profile in TD children resulted in a modulation of the posterior N2 ERP component, with cortical sources in the lateral-occipital and medial/inferior temporal areas. In contrast, children with ASD did not show modulation of the N2 and related activations in the ventral visual stream. Furthermore, behavioural and neurophysiological measures of weaker suppression predicted more severe autistic symptomatology. The present findings, showing an altered center-surround profile during attentional selection, give an important insight to understand superior visual processing in autism as well as the experiencing of sensory overload. Keywords: EEG, Source analysis, Ventral visual stream, Perception, Rehabilitation

  7. A review of strategic environmental assessment in 12 selected countries

    International Nuclear Information System (INIS)

    Chaker, A.; El-Fadl, K.; Chamas, L.; Hatjian, B.

    2006-01-01

    Strategic Environmental Assessment (SEA) is acknowledged to be an important decision support tool. The increased application of its principles in countries worldwide, the introduction of SEA procedures in planning and decision-making processes of international aid and cooperation organisations, as well as the recent endorsement of two relevant legal documents in the international arena only serve to emphasise the acclaimed significance of the process. In light of the scarcity of literature exploring the practical implementation of SEA, this paper attempts to provide a comparative overview of SEA systems in 12 selected countries from their legal, institutional and procedural perspectives in order to unveil potential implementation pitfalls, obstacles and lessons learnt as well as uncertainties and lack of data for future research, replication and customisation elsewhere or refining of existing systems

  8. Simulating the role of visual selective attention during the development of perceptual completion.

    Science.gov (United States)

    Schlesinger, Matthew; Amso, Dima; Johnson, Scott P

    2012-11-01

    We recently proposed a multi-channel, image-filtering model for simulating the development of visual selective attention in young infants (Schlesinger, Amso & Johnson, 2007). The model not only captures the performance of 3-month-olds on a visual search task, but also implicates two cortical regions that may play a role in the development of visual selective attention. In the current simulation study, we used the same model to simulate 3-month-olds' performance on a second measure, the perceptual unity task. Two parameters in the model - corresponding to areas in the occipital and parietal cortices - were systematically varied while the gaze patterns produced by the model were recorded and subsequently analyzed. Three key findings emerged from the simulation study. First, the model successfully replicated the performance of 3-month-olds on the unity perception task. Second, the model also helps to explain the improved performance of 2-month-olds when the size of the occluder in the unity perception task is reduced. Third, in contrast to our previous simulation results, variation in only one of the two cortical regions simulated (i.e. recurrent activity in posterior parietal cortex) resulted in a performance pattern that matched 3-month-olds. These findings provide additional support for our hypothesis that the development of perceptual completion in early infancy is promoted by progressive improvements in visual selective attention and oculomotor skill. © 2012 Blackwell Publishing Ltd.

  9. Environmental Risk Assessment of Selected Antibiotics in Iran

    Directory of Open Access Journals (Sweden)

    A Alighardashi

    2014-08-01

    Full Text Available In recent years the increasing use of pharmaceuticals and personal-care products (PPCPs, especially antibiotics, has become a particular concern because of their undesirable potential ecological and human health effects. This study presents an environmental risk assessment for the aquatic environment of some frequently used antibiotics in Iran in three stages including; a short literature review about antibiotic consumption in Iran, a comprehensive estimation regarding acute toxicity of selected antibiotics and finally calculation of Risk Quotient (RQ using the predicted environmental concentration (PEC and the predicted no-effect concentration (PNEC. According to recently published data, the consumption of antibiotics in Iran is several times greater than European countries and in case of antibiotics (e.g. Penicillin is approximately 10 times greater than Scandinavian region. The calculated PECs were ranged from 0.0071 to 0.8570 and the PNECs value based on ecotoxicity data was found for all studied antibiotics (varied from 0.0037 to 177. The RQ exceeded one for Amoxicillin, Penicillin G, Sulfamethoxazole, and Erythromycin. Amoxicillin has the highest risk to aquatic organisms based on this study. With respect to the emergence of microbial resistance, it is important to begin monitoring the most frequently used antibiotics

  10. Visual Literacy in the Digital Age: Selected Readings from the Annual Conference of the International Visual Literacy Association (25th, Rochester, New York, October 13-17, 1993).

    Science.gov (United States)

    Beauchamp, Darrel G.; And Others

    This document contains selected papers from the 25th annual conference of the International Visual Literacy Association (IVLA). Topics addressed in the papers include the following: visual literacy; graphic information in research and education; evaluation criteria for instructional media; understanding symbols in business presentations;…

  11. VisionQuest: Journeys toward Visual Literacy. Selected Readings from the Annual Conference of the International Visual Literacy Association (28th, Cheyenne, Wyoming, October, 1996).

    Science.gov (United States)

    Griffin, Robert E., Ed.; And Others

    This document contains 59 selected papers from the 1996 International Visual Literacy Association (IVLA) conference. Topics include: learning to think visually; information design via the Internet; a program for inner-city at-risk children; dubbing versus subtitling television programs; connecting advertisements and classroom reading through…

  12. Self-construal priming selectively modulates the scope of visual attention

    Directory of Open Access Journals (Sweden)

    Zhuozhuo eLiu

    2015-09-01

    Full Text Available Self-concept is one of the major factors to explain the cultural differences between East Asians and Westerners. In the field of visual attention, most studies have focused on the modulation of visual spatial-based attention, whereas possible influences of culture or self-concept on other types of visual attention remain largely unexplored. The present study investigated the possible modulation of visual feature-based attention by self-concept, using a within-group self-construal priming design. The experiment paradigm employed visual stimuli consisted of two intermixing random dot clouds presented in the focal visual field with red and green colors. After primed with an interdependent, independent or neutral self-construal, the participants were instructed to attend to one of the focally presented dot cloud and respond to occasional luminance decrement events of the attended dot cloud. The detection of the focal events was found to be significantly faster when exogenously cued by a peripheral dot cloud of either the same or different colors as the attended focal dot cloud (congruent / incongruent, compared to the uncued condition. More importantly, the self-construal priming took effect only on the reaction time (RT differences between the congruent and incongruent cued conditions: the participants responded much slower to incongruent cued events than congruent cued events under interdependent self-construal priming, while the RT difference was significantly smaller under independent self-construal priming. A closer look on the results suggests that the attention scope is selectively modulated by self-construal priming, and the modulation is mainly reflected by varying the degree of suppression on the processing of the incongruent contextual stimuli that do not share visual features with the focal object. Our findings provide new evidences that could possibly extend the current understanding on the cultural influence on visual attention.

  13. An Environmental Decision Support System for Spatial Assessment and Selective Remediation

    Science.gov (United States)

    Spatial Analysis and Decision Assistance (SADA) is a Windows freeware program that incorporates environmental assessment tools for effective problem-solving. The software integrates modules for GIS, visualization, geospatial analysis, statistical analysis, human health and ecolog...

  14. Visual Input Enhances Selective Speech Envelope Tracking in Auditory Cortex at a ‘Cocktail Party’

    Science.gov (United States)

    Golumbic, Elana Zion; Cogan, Gregory B.; Schroeder, Charles E.; Poeppel, David

    2013-01-01

    Our ability to selectively attend to one auditory signal amidst competing input streams, epitomized by the ‘Cocktail Party’ problem, continues to stimulate research from various approaches. How this demanding perceptual feat is achieved from a neural systems perspective remains unclear and controversial. It is well established that neural responses to attended stimuli are enhanced compared to responses to ignored ones, but responses to ignored stimuli are nonetheless highly significant, leading to interference in performance. We investigated whether congruent visual input of an attended speaker enhances cortical selectivity in auditory cortex, leading to diminished representation of ignored stimuli. We recorded magnetoencephalographic (MEG) signals from human participants as they attended to segments of natural continuous speech. Using two complementary methods of quantifying the neural response to speech, we found that viewing a speaker’s face enhances the capacity of auditory cortex to track the temporal speech envelope of that speaker. This mechanism was most effective in a ‘Cocktail Party’ setting, promoting preferential tracking of the attended speaker, whereas without visual input no significant attentional modulation was observed. These neurophysiological results underscore the importance of visual input in resolving perceptual ambiguity in a noisy environment. Since visual cues in speech precede the associated auditory signals, they likely serve a predictive role in facilitating auditory processing of speech, perhaps by directing attentional resources to appropriate points in time when to-be-attended acoustic input is expected to arrive. PMID:23345218

  15. Hierarchical event selection for video storyboards with a case study on snooker video visualization.

    Science.gov (United States)

    Parry, Matthew L; Legg, Philip A; Chung, David H S; Griffiths, Iwan W; Chen, Min

    2011-12-01

    Video storyboard, which is a form of video visualization, summarizes the major events in a video using illustrative visualization. There are three main technical challenges in creating a video storyboard, (a) event classification, (b) event selection and (c) event illustration. Among these challenges, (a) is highly application-dependent and requires a significant amount of application specific semantics to be encoded in a system or manually specified by users. This paper focuses on challenges (b) and (c). In particular, we present a framework for hierarchical event representation, and an importance-based selection algorithm for supporting the creation of a video storyboard from a video. We consider the storyboard to be an event summarization for the whole video, whilst each individual illustration on the board is also an event summarization but for a smaller time window. We utilized a 3D visualization template for depicting and annotating events in illustrations. To demonstrate the concepts and algorithms developed, we use Snooker video visualization as a case study, because it has a concrete and agreeable set of semantic definitions for events and can make use of existing techniques of event detection and 3D reconstruction in a reliable manner. Nevertheless, most of our concepts and algorithms developed for challenges (b) and (c) can be applied to other application areas. © 2010 IEEE

  16. Sound frequency and aural selectivity in sound-contingent visual motion aftereffect.

    Directory of Open Access Journals (Sweden)

    Maori Kobayashi

    Full Text Available BACKGROUND: One possible strategy to evaluate whether signals in different modalities originate from a common external event or object is to form associations between inputs from different senses. This strategy would be quite effective because signals in different modalities from a common external event would then be aligned spatially and temporally. Indeed, it has been demonstrated that after adaptation to visual apparent motion paired with alternating auditory tones, the tones begin to trigger illusory motion perception to a static visual stimulus, where the perceived direction of visual lateral motion depends on the order in which the tones are replayed. The mechanisms underlying this phenomenon remain unclear. One important approach to understanding the mechanisms is to examine whether the effect has some selectivity in auditory processing. However, it has not yet been determined whether this aftereffect can be transferred across sound frequencies and between ears. METHODOLOGY/PRINCIPAL FINDINGS: Two circles placed side by side were presented in alternation, producing apparent motion perception, and each onset was accompanied by a tone burst of a specific and unique frequency. After exposure to this visual apparent motion with tones for a few minutes, the tones became drivers for illusory motion perception. However, the aftereffect was observed only when the adapter and test tones were presented at the same frequency and to the same ear. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the auditory processing underlying the establishment of novel audiovisual associations is selective, potentially but not necessarily indicating that this processing occurs at an early stage.

  17. Robust selectivity to two-object images in human visual cortex

    Science.gov (United States)

    Agam, Yigal; Liu, Hesheng; Papanastassiou, Alexander; Buia, Calin; Golby, Alexandra J.; Madsen, Joseph R.; Kreiman, Gabriel

    2010-01-01

    SUMMARY We can recognize objects in a fraction of a second in spite of the presence of other objects [1–3]. The responses in macaque areas V4 and inferior temporal cortex [4–15] to a neuron’s preferred stimuli are typically suppressed by the addition of a second object within the receptive field (see however [16, 17]). How can this suppression be reconciled with rapid visual recognition in complex scenes? One option is that certain “special categories” are unaffected by other objects [18] but this leaves the problem unsolved for other categories. Another possibility is that serial attentional shifts help ameliorate the problem of distractor objects [19–21]. Yet, psychophysical studies [1–3], scalp recordings [1] and neurophysiological recordings [14, 16, 22–24], suggest that the initial sweep of visual processing contains a significant amount of information. We recorded intracranial field potentials in human visual cortex during presentation of flashes of two-object images. Visual selectivity from temporal cortex during the initial ~200 ms was largely robust to the presence of other objects. We could train linear decoders on the responses to isolated objects and decode information in two-object images. These observations are compatible with parallel, hierarchical and feed-forward theories of rapid visual recognition [25] and may provide a neural substrate to begin to unravel rapid recognition in natural scenes. PMID:20417105

  18. Priming of pop-out modulates attentional target selection in visual search: Behavioural and electrophysiological evidence

    OpenAIRE

    Eimer, Martin; Kiss, Monika; Cheung, Theodore

    2009-01-01

    Previous behavioural studies have shown that the repetition of target or distractor features across trials speeds pop-out visual search. We obtained behavioural and event-related brain potential (ERP) measures in two experiments where participants searched for a colour singleton target among homogeneously coloured distractors. An ERP marker of spatially selective attention (N2pc component) was delayed when either target or distractor colours were swapped across successive trials, demonstratin...

  19. Age-Related Changes in Selective Attention and Perceptual Load During Visual Search

    OpenAIRE

    Madden, David J.; Langley, Linda K.

    2003-01-01

    Three visual search experiments were conducted to test the hypothesis that age differences in selective attention vary as a function of perceptual load (E. A. Maylor & N. Lavie, 1998). Under resource-limited conditions (Experiments 1 and 2), the distraction from irrelevant display items generally decreased as display size (perceptual load) increased. This perceptual load effect was similar for younger and older adults, contrary to the findings of Maylor and Lavie. Distraction at low perceptua...

  20. Selective visual scaling of time-scale processes facilitates broadband learning of isometric force frequency tracking.

    Science.gov (United States)

    King, Adam C; Newell, Karl M

    2015-10-01

    The experiment investigated the effect of selectively augmenting faster time scales of visual feedback information on the learning and transfer of continuous isometric force tracking tasks to test the generality of the self-organization of 1/f properties of force output. Three experimental groups tracked an irregular target pattern either under a standard fixed gain condition or with selectively enhancement in the visual feedback display of intermediate (4-8 Hz) or high (8-12 Hz) frequency components of the force output. All groups reduced tracking error over practice, with the error lowest in the intermediate scaling condition followed by the high scaling and fixed gain conditions, respectively. Selective visual scaling induced persistent changes across the frequency spectrum, with the strongest effect in the intermediate scaling condition and positive transfer to novel feedback displays. The findings reveal an interdependence of the timescales in the learning and transfer of isometric force output frequency structures consistent with 1/f process models of the time scales of motor output variability.

  1. Expectation violations in sensorimotor sequences: shifting from LTM-based attentional selection to visual search.

    Science.gov (United States)

    Foerster, Rebecca M; Schneider, Werner X

    2015-03-01

    Long-term memory (LTM) delivers important control signals for attentional selection. LTM expectations have an important role in guiding the task-driven sequence of covert attention and gaze shifts, especially in well-practiced multistep sensorimotor actions. What happens when LTM expectations are disconfirmed? Does a sensory-based visual-search mode of attentional selection replace the LTM-based mode? What happens when prior LTM expectations become valid again? We investigated these questions in a computerized version of the number-connection test. Participants clicked on spatially distributed numbered shapes in ascending order while gaze was recorded. Sixty trials were performed with a constant spatial arrangement. In 20 consecutive trials, either numbers, shapes, both, or no features switched position. In 20 reversion trials, participants worked on the original arrangement. Only the sequence-affecting number switches elicited slower clicking, visual search-like scanning, and lower eye-hand synchrony. The effects were neither limited to the exchanged numbers nor to the corresponding actions. Thus, expectation violations in a well-learned sensorimotor sequence cause a regression from LTM-based attentional selection to visual search beyond deviant-related actions and locations. Effects lasted for several trials and reappeared during reversion. © 2015 New York Academy of Sciences.

  2. Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

    Science.gov (United States)

    Sheremata, Summer L; Somers, David C; Shomstein, Sarah

    2018-02-07

    Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

  3. Leading product-related environmental performance indicators: a selection guide and database

    DEFF Research Database (Denmark)

    Issa, Isabela I.; Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2015-01-01

    Ecodesign is a proactive environmental management and improvement approach employed in the product development process, which aims to minimize the environmental impacts caused during a product's life cycle and thus improve its environmental performance. The establishment of measurable environmental...... in the selection and application of environmental performance indicators - a more structured approach is still lacking. This paper presents the efforts made to identify and systematize existing leading product-related environmental performance indicators, based on a systematic literature review, and to develop...

  4. Category Selectivity of Human Visual Cortex in Perception of Rubin Face–Vase Illusion

    Directory of Open Access Journals (Sweden)

    Xiaogang Wang

    2017-09-01

    Full Text Available When viewing the Rubin face–vase illusion, our conscious perception spontaneously alternates between the face and the vase; this illusion has been widely used to explore bistable perception. Previous functional magnetic resonance imaging (fMRI studies have studied the neural mechanisms underlying bistable perception through univariate and multivariate pattern analyses; however, no studies have investigated the issue of category selectivity. Here, we used fMRI to investigate the neural mechanisms underlying the Rubin face–vase illusion by introducing univariate amplitude and multivariate pattern analyses. The results from the amplitude analysis suggested that the activity in the fusiform face area was likely related to the subjective face perception. Furthermore, the pattern analysis results showed that the early visual cortex (EVC and the face-selective cortex could discriminate the activity patterns of the face and vase perceptions. However, further analysis of the activity patterns showed that only the face-selective cortex contains the face information. These findings indicated that although the EVC and face-selective cortex activities could discriminate the visual information, only the activity and activity pattern in the face-selective areas contained the category information of face perception in the Rubin face–vase illusion.

  5. Sensation seeking and visual selective attention in adults with HIV/AIDS.

    Science.gov (United States)

    Hardy, David J; Castellon, Steven A; Hinkin, Charles H; Levine, Andrew J; Lam, Mona N

    2008-11-01

    The association between sensation seeking and visual selective attention was examined in 31 adults with the Human Immunodeficiency Virus (HIV). Sensation seeking was measured with Zuckerman's Sensation Seeking Scale Form V (SSS-V). Selective attention was assessed with a perceptual span task, where a target letter-character must be identified in a quickly presented array of nontarget letter-characters. As predicted, sensation seeking was strongly associated (R(2) = .229) with perceptual span performance in the array size 12 condition, where selective attention demands were greatest, but not in the easier conditions. The Disinhibition, Boredom Susceptibility, and Experience Seeking subscales of the SSS-V were associated with span performance. It is argued that personality factors such as sensation seeking may play a significant role in selective attention and related cognitive abilities in HIV positive adults. Furthermore, sensation seeking differences might explain certain inconsistencies in the HIV neuropsychology literature.

  6. A reaction-diffusion model to capture disparity selectivity in primary visual cortex.

    Directory of Open Access Journals (Sweden)

    Mohammed Sultan Mohiuddin Siddiqui

    Full Text Available Decades of experimental studies are available on disparity selective cells in visual cortex of macaque and cat. Recently, local disparity map for iso-orientation sites for near-vertical edge preference is reported in area 18 of cat visual cortex. No experiment is yet reported on complete disparity map in V1. Disparity map for layer IV in V1 can provide insight into how disparity selective complex cell receptive field is organized from simple cell subunits. Though substantial amounts of experimental data on disparity selective cells is available, no model on receptive field development of such cells or disparity map development exists in literature. We model disparity selectivity in layer IV of cat V1 using a reaction-diffusion two-eye paradigm. In this model, the wiring between LGN and cortical layer IV is determined by resource an LGN cell has for supporting connections to cortical cells and competition for target space in layer IV. While competing for target space, the same type of LGN cells, irrespective of whether it belongs to left-eye-specific or right-eye-specific LGN layer, cooperate with each other while trying to push off the other type. Our model captures realistic 2D disparity selective simple cell receptive fields, their response properties and disparity map along with orientation and ocular dominance maps. There is lack of correlation between ocular dominance and disparity selectivity at the cell population level. At the map level, disparity selectivity topography is not random but weakly clustered for similar preferred disparities. This is similar to the experimental result reported for macaque. The details of weakly clustered disparity selectivity map in V1 indicate two types of complex cell receptive field organization.

  7. Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.

    Science.gov (United States)

    Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

    2017-12-01

    Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.

  8. The temporal dynamics of visual working memory guidance of selective attention.

    Science.gov (United States)

    Tan, Jinfeng; Zhao, Yuanfang; Wu, Shanshan; Wang, Lijun; Hitchman, Glenn; Tian, Xia; Li, Ming; Hu, Li; Chen, Antao

    2014-01-01

    The biased competition model proposes that there is top-down directing of attention to a stimulus matching the contents of working memory (WM), even when the maintenance of a WM representation is detrimental to target relevant performance. Despite many studies elucidating that spatial WM guidance can be present early in the visual processing system, whether visual WM guidance also influences perceptual selection remains poorly understood. Here, we investigated the electrophysiological correlates of early guidance of attention by WM in humans. Participants were required to perform a visual search task while concurrently maintaining object representations in their visual WM. Behavioral results showed that response times (RTs) were longer when the distractor in the visual search task was held in WM. The earliest WM guidance effect was observed in the P1 component (90-130 ms), with match trials eliciting larger P1 amplitude than mismatch trials. A similar result was also found in the N1 component (160-200 ms). These P1 and N1 effects could not be attributed to bottom-up perceptual priming from the presentation of a memory cue, because there was no significant difference in early event-related potential (ERP) component when the cue was merely perceptually identified but not actively held in WM. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the early WM guidance occurred in the occipital lobe and the N1-related activation occurred in the parietal gyrus. Time-frequency data suggested that alpha-band event-related spectral perturbation (ERSP) magnitudes increased under the match condition compared with the mismatch condition only when the cue was held in WM. In conclusion, the present study suggests that the reappearance of a stimulus held in WM enhanced activity in the occipital area. Subsequently, this initial capture of attention by WM could be inhibited by competing visual inputs through attention re-orientation, reflecting by the

  9. The temporal dynamics of visual working memory guidance of selective attention

    Directory of Open Access Journals (Sweden)

    Jinfeng eTan

    2014-09-01

    Full Text Available The biased competition model proposes that there is top-down directing of attention to a stimulus matching the contents of working memory (WM, even when the maintenance of a WM representation is detrimental to target relevant performance. Despite many studies elucidating that spatial WM guidance can be present early in the visual processing system, whether visual WM guidance also influences perceptual selection remains poorly understood. Here, we investigated the electrophysiological correlates of early guidance of attention by WM in humans. Participants were required to perform a visual search task while concurrently maintaining object representations in their visual working memory. Behavioral results showed that response times (RTs were longer when the distractor in the visual search task was held in WM. The earliest WM guidance effect was observed in the P1 component (90-130 ms, with match trials eliciting larger P1 amplitude than mismatch trials. A similar result was also found in the N1 component (160-200 ms. These P1 and N1 effects could not be attributed to bottom-up perceptual priming from the presentation of a memory cue, because there was no significant difference in early ERP component when the cue was merely perceptually identified but not actively held in working memory. Standardized Low Resolution Electrical Tomography Analysis (sLORETA showed that the early WM guidance occurred in the occipital lobe and the N1-related activation occurred in the parietal gyrus. Time-frequency data suggested that alpha-band event-related spectral perturbation (ERSP magnitudes increased under the match condition compared with the mismatch condition. In conclusion, the present study suggests that the reappearance of a stimulus held in WM enhanced activity in the occipital area. Subsequently, this initial capture of attention by WM could be inhibited by competing visual inputs through attention re-orientation, reflecting by the alpha-band rhythm.

  10. Pawtucket R.I. Group Selected for EPA Environmental Workforce Development and Job Training Program Grant

    Science.gov (United States)

    Groundwork Rhode Island, a Pawtucket-based organization, was one of 17 groups selected today by the U.S. Environmental Protection Agency (EPA) to share $3.3 million to operate environmental job training programs for local citizens.

  11. Color Functionality Used in Visual Display for Occupational and Environmental Safety and Managing Color Vision Deficiency.

    Science.gov (United States)

    Ochiai, Nobuhisa; Kondo, Hiroyuki

    2017-01-01

    The effects of color perception are utilized in visual displays for the purpose of safety in the workplace and in daily life. These effects, generally known as color functionality, are divided into four classifications: visibility, legibility, conspicuity and discriminability. This article focuses on the relationship between the color functionality of color schemes used in visual displays for occupational and environmental safety and color vision deficiency (particularly congenital red-green color deficiency), a critical issue in ophthalmology, and examines the effects of color functionality on the perception of the color red in individuals with protan defects. Due to abrupt system reforms, current Japanese clinical ophthalmology finds itself in a situation where it is insufficiently prepared to handle congenital red-green color deficiencies. Indeed, occupational problems caused by color vision deficiencies have been almost completely neglected, and are an occupational safety and health concern that will need to be solved in the future. This report will present the guidelines for the color vision testing established by the British Health and Safety Executive (HSE), a pioneering example of a model meant to solve these problems. Issues relating to the creation of guidelines adapted to Japanese clinical ophthalmology will also be examined, and we will discuss ways to utilize color functionality used in visual displays for occupational and environmental safety to help manage color vision deficiency.

  12. Effects of prey abundance, distribution, visual contrast and morphology on selection by a pelagic piscivore

    Science.gov (United States)

    Hansen, Adam G.; Beauchamp, David A.

    2014-01-01

    Most predators eat only a subset of possible prey. However, studies evaluating diet selection rarely measure prey availability in a manner that accounts for temporal–spatial overlap with predators, the sensory mechanisms employed to detect prey, and constraints on prey capture.We evaluated the diet selection of cutthroat trout (Oncorhynchus clarkii) feeding on a diverse planktivore assemblage in Lake Washington to test the hypothesis that the diet selection of piscivores would reflect random (opportunistic) as opposed to non-random (targeted) feeding, after accounting for predator–prey overlap, visual detection and capture constraints.Diets of cutthroat trout were sampled in autumn 2005, when the abundance of transparent, age-0 longfin smelt (Spirinchus thaleichthys) was low, and 2006, when the abundance of smelt was nearly seven times higher. Diet selection was evaluated separately using depth-integrated and depth-specific (accounted for predator–prey overlap) prey abundance. The abundance of different prey was then adjusted for differences in detectability and vulnerability to predation to see whether these factors could explain diet selection.In 2005, cutthroat trout fed non-randomly by selecting against the smaller, transparent age-0 longfin smelt, but for the larger age-1 longfin smelt. After adjusting prey abundance for visual detection and capture, cutthroat trout fed randomly. In 2006, depth-integrated and depth-specific abundance explained the diets of cutthroat trout well, indicating random feeding. Feeding became non-random after adjusting for visual detection and capture. Cutthroat trout selected strongly for age-0 longfin smelt, but against similar sized threespine stickleback (Gasterosteus aculeatus) and larger age-1 longfin smelt in 2006. Overlap with juvenile sockeye salmon (O. nerka) was minimal in both years, and sockeye salmon were rare in the diets of cutthroat trout.The direction of the shift between random and non-random selection

  13. Google-Earth Based Visualizations for Environmental Flows and Pollutant Dispersion in Urban Areas

    Directory of Open Access Journals (Sweden)

    Daoming Liu

    2017-03-01

    Full Text Available In the present study, we address the development and application of an efficient tool for conversion of results obtained by an integrated computational fluid dynamics (CFD and computational reaction dynamics (CRD approach and their visualization in the Google Earth. We focus on results typical for environmental fluid mechanics studies at a city scale that include characteristic wind flow patterns and dispersion of reactive scalars. This is achieved by developing a code based on the Java language, which converts the typical four-dimensional structure (spatial and temporal dependency of data results in the Keyhole Markup Language (KML format. The visualization techniques most often used are revisited and implemented into the conversion tool. The potential of the tool is demonstrated in a case study of smog formation due to an intense traffic emission in Rotterdam (The Netherlands. It is shown that the Google Earth can provide a computationally efficient and user-friendly means of data representation. This feature can be very useful for visualization of pollution at street levels, which is of great importance for the city residents. Various meteorological and traffic emissions can be easily visualized and analyzed, providing a powerful, user-friendly tool for traffic regulations and urban climate adaptations.

  14. A multichip aVLSI system emulating orientation selectivity of primary visual cortical cells.

    Science.gov (United States)

    Shimonomura, Kazuhiro; Yagi, Tetsuya

    2005-07-01

    In this paper, we designed and fabricated a multichip neuromorphic analog very large scale integrated (aVLSI) system, which emulates the orientation selective response of the simple cell in the primary visual cortex. The system consists of a silicon retina and an orientation chip. An image, which is filtered by a concentric center-surround (CS) antagonistic receptive field of the silicon retina, is transferred to the orientation chip. The image transfer from the silicon retina to the orientation chip is carried out with analog signals. The orientation chip selectively aggregates multiple pixels of the silicon retina, mimicking the feedforward model proposed by Hubel and Wiesel. The chip provides the orientation-selective (OS) outputs which are tuned to 0 degrees, 60 degrees, and 120 degrees. The feed-forward aggregation reduces the fixed pattern noise that is due to the mismatch of the transistors in the orientation chip. The spatial properties of the orientation selective response were examined in terms of the adjustable parameters of the chip, i.e., the number of aggregated pixels and size of the receptive field of the silicon retina. The multichip aVLSI architecture used in the present study can be applied to implement higher order cells such as the complex cell of the primary visual cortex.

  15. Selective attention reduces physiological noise in the external ear canals of humans. II: Visual attention

    Science.gov (United States)

    Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

    2014-01-01

    Human subjects performed in several behavioral conditions requiring, or not requiring, selective attention to visual stimuli. Specifically, the attentional task was to recognize strings of digits that had been presented visually. A nonlinear version of the stimulus-frequency otoacoustic emission (SFOAE), called the nSFOAE, was collected during the visual presentation of the digits. The segment of the physiological response discussed here occurred during brief silent periods immediately following the SFOAE-evoking stimuli. For all subjects tested, the physiological-noise magnitudes were substantially weaker (less noisy) during the tasks requiring the most visual attention. Effect sizes for the differences were >2.0. Our interpretation is that cortico-olivo influences adjusted the magnitude of efferent activation during the SFOAE-evoking stimulation depending upon the attention task in effect, and then that magnitude of efferent activation persisted throughout the silent period where it also modulated the physiological noise present. Because the results were highly similar to those obtained when the behavioral conditions involved auditory attention, similar mechanisms appear to operate both across modalities and within modalities. Supplementary measurements revealed that the efferent activation was spectrally global, as it was for auditory attention. PMID:24732070

  16. Reward speeds up and increases consistency of visual selective attention: a lifespan comparison.

    Science.gov (United States)

    Störmer, Viola; Eppinger, Ben; Li, Shu-Chen

    2014-06-01

    Children and older adults often show less favorable reward-based learning and decision making, relative to younger adults. It is unknown, however, whether reward-based processes that influence relatively early perceptual and attentional processes show similar lifespan differences. In this study, we investigated whether stimulus-reward associations affect selective visual attention differently across the human lifespan. Children, adolescents, younger adults, and older adults performed a visual search task in which the target colors were associated with either high or low monetary rewards. We discovered that high reward value speeded up response times across all four age groups, indicating that reward modulates attentional selection across the lifespan. This speed-up in response time was largest in younger adults, relative to the other three age groups. Furthermore, only younger adults benefited from high reward value in increasing response consistency (i.e., reduction of trial-by-trial reaction time variability). Our findings suggest that reward-based modulations of relatively early and implicit perceptual and attentional processes are operative across the lifespan, and the effects appear to be greater in adulthood. The age-specific effect of reward on reducing intraindividual response variability in younger adults likely reflects mechanisms underlying the development and aging of reward processing, such as lifespan age differences in the efficacy of dopaminergic modulation. Overall, the present results indicate that reward shapes visual perception across different age groups by biasing attention to motivationally salient events.

  17. Using geometric morphometric visualizations of directional selection gradients to investigate morphological differentiation.

    Science.gov (United States)

    Weaver, Timothy D; Gunz, Philipp

    2018-04-01

    Researchers studying extant and extinct taxa are often interested in identifying the evolutionary processes that have lead to the morphological differences among the taxa. Ideally, one could distinguish the influences of neutral evolutionary processes (genetic drift, mutation) from natural selection, and in situations for which selection is implicated, identify the targets of selection. The directional selection gradient is an effective tool for investigating evolutionary process, because it can relate form (size and shape) differences between taxa to the variation and covariation found within taxa. However, although most modern morphometric analyses use the tools of geometric morphometrics (GM) to analyze landmark data, to date, selection gradients have mainly been calculated from linear measurements. To address this methodological gap, here we present a GM approach for visualizing and comparing between-taxon selection gradients with each other, associated difference vectors, and "selection" gradients from neutral simulations. To exemplify our approach, we use a dataset of 347 three-dimensional landmarks and semilandmarks recorded on the crania of 260 primate specimens (112 humans, 67 common chimpanzees, 36 bonobos, 45 gorillas). Results on this example dataset show how incorporating geometric information can provide important insights into the evolution of the human braincase, and serve to demonstrate the utility of our approach for understanding morphological evolution. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  18. How learning might strengthen existing visual object representations in human object-selective cortex.

    Science.gov (United States)

    Brants, Marijke; Bulthé, Jessica; Daniels, Nicky; Wagemans, Johan; Op de Beeck, Hans P

    2016-02-15

    Visual object perception is an important function in primates which can be fine-tuned by experience, even in adults. Which factors determine the regions and the neurons that are modified by learning is still unclear. Recently, it was proposed that the exact cortical focus and distribution of learning effects might depend upon the pre-learning mapping of relevant functional properties and how this mapping determines the informativeness of neural units for the stimuli and the task to be learned. From this hypothesis we would expect that visual experience would strengthen the pre-learning distributed functional map of the relevant distinctive object properties. Here we present a first test of this prediction in twelve human subjects who were trained in object categorization and differentiation, preceded and followed by a functional magnetic resonance imaging session. Specifically, training increased the distributed multi-voxel pattern information for trained object distinctions in object-selective cortex, resulting in a generalization from pre-training multi-voxel activity patterns to after-training activity patterns. Simulations show that the increased selectivity combined with the inter-session generalization is consistent with a training-induced strengthening of a pre-existing selectivity map. No training-related neural changes were detected in other regions. In sum, training to categorize or individuate objects strengthened pre-existing representations in human object-selective cortex, providing a first indication that the neuroanatomical distribution of learning effects depends upon the pre-learning mapping of visual object properties. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Space-based visual attention: a marker of immature selective attention in toddlers?

    Science.gov (United States)

    Rivière, James; Brisson, Julie

    2014-11-01

    Various studies suggested that attentional difficulties cause toddlers' failure in some spatial search tasks. However, attention is not a unitary construct and this study investigated two attentional mechanisms: location selection (space-based attention) and object selection (object-based attention). We investigated how toddlers' attention is distributed in the visual field during a manual search task for objects moving out of sight, namely the moving boxes task. Results show that 2.5-year-olds who failed this task allocated more attention to the location of the relevant object than to the object itself. These findings suggest that in some manual search tasks the primacy of space-based attention over object-based attention could be a marker of immature selective attention in toddlers. © 2014 Wiley Periodicals, Inc.

  20. Immersive virtual reality and environmental noise assessment: An innovative audio–visual approach

    International Nuclear Information System (INIS)

    Ruotolo, Francesco; Maffei, Luigi; Di Gabriele, Maria; Iachini, Tina; Masullo, Massimiliano; Ruggiero, Gennaro; Senese, Vincenzo Paolo

    2013-01-01

    Several international studies have shown that traffic noise has a negative impact on people's health and that people's annoyance does not depend only on noise energetic levels, but rather on multi-perceptual factors. The combination of virtual reality technology and audio rendering techniques allow us to experiment a new approach for environmental noise assessment that can help to investigate in advance the potential negative effects of noise associated with a specific project and that in turn can help designers to make educated decisions. In the present study, the audio–visual impact of a new motorway project on people has been assessed by means of immersive virtual reality technology. In particular, participants were exposed to 3D reconstructions of an actual landscape without the projected motorway (ante operam condition), and of the same landscape with the projected motorway (post operam condition). Furthermore, individuals' reactions to noise were assessed by means of objective cognitive measures (short term verbal memory and executive functions) and subjective evaluations (noise and visual annoyance). Overall, the results showed that the introduction of a projected motorway in the environment can have immediate detrimental effects of people's well-being depending on the distance from the noise source. In particular, noise due to the new infrastructure seems to exert a negative influence on short term verbal memory and to increase both visual and noise annoyance. The theoretical and practical implications of these findings are discussed. -- Highlights: ► Impact of traffic noise on people's well-being depends on multi-perceptual factors. ► A multisensory virtual reality technology is used to simulate a projected motorway. ► Effects on short-term memory and auditory and visual subjective annoyance were found. ► The closer the distance from the motorway the stronger was the effect. ► Multisensory virtual reality methodologies can be used to study

  1. Immersive virtual reality and environmental noise assessment: An innovative audio–visual approach

    Energy Technology Data Exchange (ETDEWEB)

    Ruotolo, Francesco, E-mail: francesco.ruotolo@unina2.it [Laboratory of Cognitive Science and Immersive Virtual Reality, Department of Psychology, Second University of Naples, Viale Ellittico, 31, 81100, Caserta (Italy); Maffei, Luigi, E-mail: luigi.maffei@unina2.it [Department of Architecture and Industrial Design, Second University of Naples, Abazia di S. Lorenzo, 81031, Aversa (Italy); Di Gabriele, Maria, E-mail: maria.digabriele@unina2.it [Department of Architecture and Industrial Design, Second University of Naples, Abazia di S. Lorenzo, 81031, Aversa (Italy); Iachini, Tina, E-mail: santa.iachini@unina2.it [Laboratory of Cognitive Science and Immersive Virtual Reality, Department of Psychology, Second University of Naples, Viale Ellittico, 31, 81100, Caserta (Italy); Masullo, Massimiliano, E-mail: massimiliano.masullo@unina2.it [Department of Architecture and Industrial Design, Second University of Naples, Abazia di S. Lorenzo, 81031, Aversa (Italy); Ruggiero, Gennaro, E-mail: gennaro.ruggiero@unina2.it [Laboratory of Cognitive Science and Immersive Virtual Reality, Department of Psychology, Second University of Naples, Viale Ellittico, 31, 81100, Caserta (Italy); Senese, Vincenzo Paolo, E-mail: vincenzopaolo.senese@unina2.it [Laboratory of Cognitive Science and Immersive Virtual Reality, Department of Psychology, Second University of Naples, Viale Ellittico, 31, 81100, Caserta (Italy); Psychometric Laboratory, Department of Psychology, Second University of Naples, Viale Ellittico, 31, 81100, Caserta (Italy)

    2013-07-15

    Several international studies have shown that traffic noise has a negative impact on people's health and that people's annoyance does not depend only on noise energetic levels, but rather on multi-perceptual factors. The combination of virtual reality technology and audio rendering techniques allow us to experiment a new approach for environmental noise assessment that can help to investigate in advance the potential negative effects of noise associated with a specific project and that in turn can help designers to make educated decisions. In the present study, the audio–visual impact of a new motorway project on people has been assessed by means of immersive virtual reality technology. In particular, participants were exposed to 3D reconstructions of an actual landscape without the projected motorway (ante operam condition), and of the same landscape with the projected motorway (post operam condition). Furthermore, individuals' reactions to noise were assessed by means of objective cognitive measures (short term verbal memory and executive functions) and subjective evaluations (noise and visual annoyance). Overall, the results showed that the introduction of a projected motorway in the environment can have immediate detrimental effects of people's well-being depending on the distance from the noise source. In particular, noise due to the new infrastructure seems to exert a negative influence on short term verbal memory and to increase both visual and noise annoyance. The theoretical and practical implications of these findings are discussed. -- Highlights: ► Impact of traffic noise on people's well-being depends on multi-perceptual factors. ► A multisensory virtual reality technology is used to simulate a projected motorway. ► Effects on short-term memory and auditory and visual subjective annoyance were found. ► The closer the distance from the motorway the stronger was the effect. ► Multisensory virtual reality methodologies

  2. Calcium dynamics in root cells of Arabidopsis thaliana visualized with selective plane illumination microscopy.

    Directory of Open Access Journals (Sweden)

    Alex Costa

    Full Text Available Selective Plane Illumination Microscopy (SPIM is an imaging technique particularly suited for long term in-vivo analysis of transparent specimens, able to visualize small organs or entire organisms, at cellular and eventually even subcellular resolution. Here we report the application of SPIM in Calcium imaging based on Förster Resonance Energy Transfer (FRET. Transgenic Arabidopsis plants expressing the genetically encoded-FRET-based Ca(2+ probe Cameleon, in the cytosol or nucleus, were used to demonstrate that SPIM enables ratiometric fluorescence imaging at high spatial and temporal resolution, both at tissue and single cell level. The SPIM-FRET technique enabled us to follow nuclear and cytosolic Ca(2+ dynamics in Arabidopsis root tip cells, deep inside the organ, in response to different stimuli. A relevant physiological phenomenon, namely Ca(2+ signal percolation, predicted in previous studies, has been directly visualized.

  3. China's Environmental Problems: Selected Issues and Solutions in Context

    OpenAIRE

    Tisdell, Clem

    1996-01-01

    China has experienced outstanding economic growth in recent decades, but not without environmental problems and costs. Environmental costs have included increased air and water pollution, loss of natural vegetation cover and deforestation, soil erosion and a decline in the fertility of the soil and biodiversity loss. Consequently, some writers have questioned whether China’s rate of growth is environmentally sustainable and doubt if China will attain middle-income status in the next century b...

  4. Linguistic processing in visual and modality-nonspecific brain areas: PET recordings during selective attention.

    Science.gov (United States)

    Vorobyev, Victor A; Alho, Kimmo; Medvedev, Svyatoslav V; Pakhomov, Sergey V; Roudas, Marina S; Rutkovskaya, Julia M; Tervaniemi, Mari; Van Zuijen, Titia L; Näätänen, Risto

    2004-07-01

    Positron emission tomography (PET) was used to investigate the neural basis of selective processing of linguistic material during concurrent presentation of multiple stimulus streams ("cocktail-party effect"). Fifteen healthy right-handed adult males were to attend to one of three simultaneously presented messages: one presented visually, one to the left ear, and one to the right ear. During the control condition, subjects attended to visually presented consonant letter strings and ignored auditory messages. This paper reports the modality-nonspecific language processing and visual word-form processing, whereas the auditory attention effects have been reported elsewhere [Cogn. Brain Res. 17 (2003) 201]. The left-hemisphere areas activated by both the selective processing of text and speech were as follows: the inferior prefrontal (Brodmann's area, BA 45, 47), anterior temporal (BA 38), posterior insular (BA 13), inferior (BA 20) and middle temporal (BA 21), occipital (BA 18/30) cortices, the caudate nucleus, and the amygdala. In addition, bilateral activations were observed in the medial occipito-temporal cortex and the cerebellum. Decreases of activation during both text and speech processing were found in the parietal (BA 7, 40), frontal (BA 6, 8, 44) and occipito-temporal (BA 37) regions of the right hemisphere. Furthermore, the present data suggest that the left occipito-temporal cortex (BA 18, 20, 37, 21) can be subdivided into three functionally distinct regions in the posterior-anterior direction on the basis of their activation during attentive processing of sublexical orthography, visual word form, and supramodal higher-level aspects of language.

  5. Comparative Analysis of Environmental Impacts of Selected Products

    Directory of Open Access Journals (Sweden)

    A. Fedoryszyn

    2013-01-01

    Full Text Available The purpose of the present study is to demonstrate that environmental impacts exerted by manufactured products throughout their entire life cycle are major aspects to be considered, alongside their functional features and cost-effectiveness. One of the available methods to evaluate environmental impacts is known to as the Life Cycle Assessment (LCA method.The study summarises the reports from the literature on the subject of environmental impact assessment. In conclusions, the authorsindicate the need for assessing the environmental impact of cast products made from conventional and newly introduced alloys.

  6. Comparative Analysis of Environmental Impacts of Selected Products

    Directory of Open Access Journals (Sweden)

    Fedoryszyn A.

    2013-03-01

    Full Text Available The purpose of the present study is to demonstrate that environmental impacts exerted by manufactured products throughout their entire life cycle are major aspects to be considered, alongside their functional features and cost-effectiveness. One of the available methods to evaluate environmental impacts is known to as the Life Cycle Assessment (LCA method. The study summarises the reports from the literature on the subject of environmental impact assessment. In conclusions, the authors indicate the need for assessing the environmental impact of cast products made from conventional and newly introduced alloys.

  7. Selected industrial and environmental applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    1999-01-01

    A review of the applications of Instrumental Neutron Activation Analysis (INAA) in the industrial and environmental fields is given. Detection limits for different applications are also given. (author)

  8. Selection of multiple cued items is possible during visual short-term memory maintenance.

    Science.gov (United States)

    Matsukura, Michi; Vecera, Shaun P

    2015-07-01

    Recent neuroimaging studies suggest that maintenance of a selected object feature held in visual short-term/working memory (VSTM/VWM) is supported by the same neural mechanisms that encode the sensory information. If VSTM operates by retaining "reasonable copies" of scenes constructed during sensory processing (Serences, Ester, Vogel, & Awh, 2009, p. 207, the sensory recruitment hypothesis), then attention should be able to select multiple items represented in VSTM as long as the number of these attended items does not exceed the typical VSTM capacity. It is well known that attention can select at least two noncontiguous locations at the same time during sensory processing. However, empirical reports from the studies that examined this possibility are inconsistent. In the present study, we demonstrate that (1) attention can indeed select more than a single item during VSTM maintenance when observers are asked to recognize a set of items in the manner that these items were originally attended, and (2) attention can select multiple cued items regardless of whether these items are perceptually organized into a single group (contiguous locations) or not (noncontiguous locations). The results also replicate and extend the recent finding that selective attention that operates during VSTM maintenance is sensitive to the observers' goal and motivation to use the cueing information.

  9. Limits of selection against cheaters: birds prioritise visual fruit advertisement over taste.

    Science.gov (United States)

    Wang, Zhen; Schaefer, H Martin

    2014-04-01

    The concept of biological markets aims to explain how organisms interact with each other. Market theory predicts that organisms choose the most rewarding partner in mutualisms. However, partner choice may also be influenced by advertisement which may not be reliable. In seed dispersal mutualism, we analysed whether seed dispersers prioritise taste cues over visual advertisement to select the most rewarding fruits and whether they select against partners with unreliable advertisement. We conducted experiments on black elder (Sambucus nigra), a species of which the colours of the peduncles match the sugar content of their fruits. We created infructescences the colours of which matched or mismatched the sugar content of their fruits. There was no selection against cheaters in the field or by captive blackcaps (Sylvia atricapilla) as seed dispersers. Blackcaps were constrained to select against unreliable advertisement because they swallowed fruits entirely and thus did not obtain an immediate feedback by taste. Instead, blackcaps selected fruits according to the colour variation of red peduncles. Overall, we suggest that the concept of constraints should be incorporated into biological markets. We further contend that biological markets can be more complex than currently acknowledged because a moderate degree of reliability occurred in black elder even in the absence of selection against cheaters.

  10. Hand placement near the visual stimulus improves orientation selectivity in V2 neurons

    Science.gov (United States)

    Sergio, Lauren E.; Crawford, J. Douglas; Fallah, Mazyar

    2015-01-01

    Often, the brain receives more sensory input than it can process simultaneously. Spatial attention helps overcome this limitation by preferentially processing input from a behaviorally-relevant location. Recent neuropsychological and psychophysical studies suggest that attention is deployed to near-hand space much like how the oculomotor system can deploy attention to an upcoming gaze position. Here we provide the first neuronal evidence that the presence of a nearby hand enhances orientation selectivity in early visual processing area V2. When the hand was placed outside the receptive field, responses to the preferred orientation were significantly enhanced without a corresponding significant increase at the orthogonal orientation. Consequently, there was also a significant sharpening of orientation tuning. In addition, the presence of the hand reduced neuronal response variability. These results indicate that attention is automatically deployed to the space around a hand, improving orientation selectivity. Importantly, this appears to be optimal for motor control of the hand, as opposed to oculomotor mechanisms which enhance responses without sharpening orientation selectivity. Effector-based mechanisms for visual enhancement thus support not only the spatiotemporal dissociation of gaze and reach, but also the optimization of vision for their separate requirements for guiding movements. PMID:25717165

  11. Selecting Environmental Performance Indicators : The Case of Numico

    NARCIS (Netherlands)

    Scherpereel, C.; Koppen, van C.S.A.; Heering, G.B.F.

    2001-01-01

    In order to achieve both efficient and reliable external communication adapted to the company's specific conditions, it is desirable to establish a clear relation between the environmental performance indicators (EPIs) used internally for environmental management and the EPIs used externally for

  12. New environmental supplier selection criteria for circular supply chains

    DEFF Research Database (Denmark)

    Prosman, Ernst Johannes; Sacchi, Romain

    2017-01-01

    upon a consequential life cycle assessment and the monetized environmental impact of four alternative fuel suppliers in the cement industry. The best supplier performs three times better than the worst supplier in terms of environmental impact, thereby exemplifying the need for this study. The findings...

  13. Fuzzy logic control for selective hydrogenation of acetylene in ethylene rich streams using visual basic

    International Nuclear Information System (INIS)

    Malik, S.R.; Suleman, H.; Khan, J.R.

    2010-01-01

    Presence of acetylene is technically disadvantageous in the ethylene rich gas streams from steam crackers. Acetylene tends to polymerize and inactivates the transition metal catalysts, forming highly explosive compounds. The acetylene content has to be selectively reduced to less than one part per million for such streams. The acetylene hydrogenation unit requires stringent control parameters and needs specialized process control techniques for its operation. This study is concerned with application of Fuzzy Logic Control to manipulate and control the process plant with higher precision and greater simplicity. The control program has been written in visual Basic and entails all major scenarios of work modes for successful hydrogenation of Acetylene. (author)

  14. Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex.

    Science.gov (United States)

    Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I; Tao, Huizhong W

    2015-08-05

    In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity

  15. Weed spectrum and selectivity of tembotrione under varying environmental conditions

    Directory of Open Access Journals (Sweden)

    Gatzweiler, Elmar

    2012-03-01

    Full Text Available Tembotrione is a novel HPPD maize herbicide effective against a wide range of broadleaf and grass weeds. Some characteristics of this compound are described in this paper linking weed and crop responses following tembotrione applications to environmental parameters or use conditions. The activity of HPPD herbicides is very much dependant on the availability of light. Increasing illumination intensities following application augmented the activity levels of several comparable HPPD compounds in a growth chamber experiment. Tembotrione was shown to be more efficacious at low and high illumination intensities compared to standard herbicides applied at the same rate. At the high intensity, tembotrione retained its high efficacy from two up to four weeks after application showing a rapid and strong herbicidal activity. The activity following post-emergent treatments of tembotrione against broadleaf weeds was influenced by soil characteristics such as soil texture and organic matter content in a glasshouse test. The level of weed suppression clearly declined stronger on heavier soils than on lighter soils at a rather low application rate of 12.5 g a.i./ha and lower. This is a clear indication of residual efficacy of tembotrione. The selectivity of tembotrione was tested on numerous maize varieties following post-emergent treatment with tembotrione alone or in mixture with the safener isoxadifen-ethyl under field conditions in Germany in comparison to a standard herbicide. The level of crop phytotoxicity tended to increase in the following order: Tembotrione plus safener, standard herbicide to tembotrione alone. Only the mixture of tembotrione with safener did not cause significant adverse effects on maize. Another field experiment in the USA examined crop phytotoxicity using one maize variety in a situation of infurrow soil insecticide treatment followed by a post-emergent application of tembotrione (plus/minus isoxadifen-ethyl and standard herbicides

  16. Visual and associated affective processing of face information in schizophrenia: A selective review.

    Science.gov (United States)

    Chen, Yue; Ekstrom, Tor

    Perception of facial features is crucial in social life. In past decades, extensive research showed that the ability to perceive facial emotion expression was compromised in schizophrenia patients. Given that face perception involves visual/cognitive and affective processing, the roles of these two processing domains in the compromised face perception in schizophrenia were studied and discussed, but not clearly defined. One particular issue was whether face-specific processing is implicated in this psychiatric disorder. Recent investigations have probed into the components of face perception processes such as visual detection, identity recognition, emotion expression discrimination and working memory conveyed from faces. Recent investigations have further assessed the associations between face processing and basic visual processing and between face processing and social cognitive processing such as Theory of Mind. In this selective review, we discuss the investigative findings relevant to the issues of cognitive and affective association and face-specific processing. We highlight the implications of multiple processing domains and face-specific processes as potential mechanisms underlying compromised face perception in schizophrenia. These findings suggest a need for a domain-specific therapeutic approach to the improvement of face perception in schizophrenia.

  17. Neurons in the thalamic reticular nucleus are selective for diverse and complex visual features

    Directory of Open Access Journals (Sweden)

    Vishal eVaingankar

    2012-12-01

    Full Text Available All visual signals the cortex receives are influenced by the perigeniculate sector of the thalamic reticular nucleus, which receives input from relay cells in the lateral geniculate and provides feedback inhibition in return. Relay cells have been studied in quantitative depth; they behave in a roughly linear fashion and have receptive fields with a stereotyped centre-surround structure. We know far less about reticular neurons. Qualitative studies indicate they simply pool ascending input to generate nonselective gain control. Yet the perigeniculate is complicated; local cells are densely interconnected and fire lengthy bursts. Thus, we employed quantitative methods to explore the perigeniculate, using relay cells as controls. By adapting methods of spike-triggered averaging and covariance analysis for bursts, we identified both first and second order features that build reticular receptive fields. The shapes of these spatiotemporal subunits varied widely; no stereotyped pattern emerged. Companion experiments showed that the shape of the first but not second order features could be explained by the overlap of On and Off inputs to a given cell. Moreover, we assessed the predictive power of the receptive field and how much information each component subunit conveyed. Linear-nonlinear models including multiple subunits performed better than those made with just one; further each subunit encoded different visual information. Model performance for reticular cells was always lesser than for relay cells, however, indicating that reticular cells process inputs nonlinearly. All told, our results suggest that the perigeniculate encodes diverse visual features to selectively modulate activity transmitted downstream

  18. From shunting inhibition to dynamic normalization: Attentional selection and decision-making in brief visual displays.

    Science.gov (United States)

    Smith, Philip L; Sewell, David K; Lilburn, Simon D

    2015-11-01

    Normalization models of visual sensitivity assume that the response of a visual mechanism is scaled divisively by the sum of the activity in the excitatory and inhibitory mechanisms in its neighborhood. Normalization models of attention assume that the weighting of excitatory and inhibitory mechanisms is modulated by attention. Such models have provided explanations of the effects of attention in both behavioral and single-cell recording studies. We show how normalization models can be obtained as the asymptotic solutions of shunting differential equations, in which stimulus inputs and the activity in the mechanism control growth rates multiplicatively rather than additively. The value of the shunting equation approach is that it characterizes the entire time course of the response, not just its asymptotic strength. We describe two models of attention based on shunting dynamics, the integrated system model of Smith and Ratcliff (2009) and the competitive interaction theory of Smith and Sewell (2013). These models assume that attention, stimulus salience, and the observer's strategy for the task jointly determine the selection of stimuli into visual short-term memory (VSTM) and the way in which stimulus representations are weighted. The quality of the VSTM representation determines the speed and accuracy of the decision. The models provide a unified account of a variety of attentional phenomena found in psychophysical tasks using single-element and multi-element displays. Our results show the generality and utility of the normalization approach to modeling attention. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Soft computing based feature selection for environmental sound classification

    NARCIS (Netherlands)

    Shakoor, A.; May, T.M.; Van Schijndel, N.H.

    2010-01-01

    Environmental sound classification has a wide range of applications,like hearing aids, mobile communication devices, portable media players, and auditory protection devices. Sound classification systemstypically extract features from the input sound. Using too many features increases complexity

  20. The mere exposure effect is modulated by selective attention but not visual awareness.

    Science.gov (United States)

    Huang, Yu-Feng; Hsieh, Po-Jang

    2013-10-18

    Repeated exposures to an object will lead to an enhancement of evaluation toward that object. Although this mere exposure effect may occur when the objects are presented subliminally, the role of conscious perception per se on evaluation has never been examined. Here we use a binocular rivalry paradigm to investigate whether a variance in conscious perceptual duration of faces has an effect on their subsequent evaluation, and how selective attention and memory interact with this effect. Our results show that face evaluation is positively biased by selective attention but not affected by visual awareness. Furthermore, this effect is not due to participants recalling which face had been attended to. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Sleep deprivation impairs object-selective attention: a view from the ventral visual cortex.

    Science.gov (United States)

    Lim, Julian; Tan, Jiat Chow; Parimal, Sarayu; Dinges, David F; Chee, Michael W L

    2010-02-05

    Most prior studies on selective attention in the setting of total sleep deprivation (SD) have focused on behavior or activation within fronto-parietal cognitive control areas. Here, we evaluated the effects of SD on the top-down biasing of activation of ventral visual cortex and on functional connectivity between cognitive control and other brain regions. Twenty-three healthy young adult volunteers underwent fMRI after a normal night of sleep (RW) and after sleep deprivation in a counterbalanced manner while performing a selective attention task. During this task, pictures of houses or faces were randomly interleaved among scrambled images. Across different blocks, volunteers responded to house but not face pictures, face but not house pictures, or passively viewed pictures without responding. The appearance of task-relevant pictures was unpredictable in this paradigm. SD resulted in less accurate detection of target pictures without affecting the mean false alarm rate or response time. In addition to a reduction of fronto-parietal activation, attending to houses strongly modulated parahippocampal place area (PPA) activation during RW, but this attention-driven biasing of PPA activation was abolished following SD. Additionally, SD resulted in a significant decrement in functional connectivity between the PPA and two cognitive control areas, the left intraparietal sulcus and the left inferior frontal lobe. SD impairs selective attention as evidenced by reduced selectivity in PPA activation. Further, reduction in fronto-parietal and ventral visual task-related activation suggests that it also affects sustained attention. Reductions in functional connectivity may be an important additional imaging parameter to consider in characterizing the effects of sleep deprivation on cognition.

  2. Sleep deprivation impairs object-selective attention: a view from the ventral visual cortex.

    Directory of Open Access Journals (Sweden)

    Julian Lim

    Full Text Available BACKGROUND: Most prior studies on selective attention in the setting of total sleep deprivation (SD have focused on behavior or activation within fronto-parietal cognitive control areas. Here, we evaluated the effects of SD on the top-down biasing of activation of ventral visual cortex and on functional connectivity between cognitive control and other brain regions. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-three healthy young adult volunteers underwent fMRI after a normal night of sleep (RW and after sleep deprivation in a counterbalanced manner while performing a selective attention task. During this task, pictures of houses or faces were randomly interleaved among scrambled images. Across different blocks, volunteers responded to house but not face pictures, face but not house pictures, or passively viewed pictures without responding. The appearance of task-relevant pictures was unpredictable in this paradigm. SD resulted in less accurate detection of target pictures without affecting the mean false alarm rate or response time. In addition to a reduction of fronto-parietal activation, attending to houses strongly modulated parahippocampal place area (PPA activation during RW, but this attention-driven biasing of PPA activation was abolished following SD. Additionally, SD resulted in a significant decrement in functional connectivity between the PPA and two cognitive control areas, the left intraparietal sulcus and the left inferior frontal lobe. CONCLUSIONS/SIGNIFICANCE: SD impairs selective attention as evidenced by reduced selectivity in PPA activation. Further, reduction in fronto-parietal and ventral visual task-related activation suggests that it also affects sustained attention. Reductions in functional connectivity may be an important additional imaging parameter to consider in characterizing the effects of sleep deprivation on cognition.

  3. Cholinergic enhancement reduces functional connectivity and BOLD variability in visual extrastriate cortex during selective attention.

    Science.gov (United States)

    Ricciardi, Emiliano; Handjaras, Giacomo; Bernardi, Giulio; Pietrini, Pietro; Furey, Maura L

    2013-01-01

    Enhancing cholinergic function improves performance on various cognitive tasks and alters neural responses in task specific brain regions. We have hypothesized that the changes in neural activity observed during increased cholinergic function reflect an increase in neural efficiency that leads to improved task performance. The current study tested this hypothesis by assessing neural efficiency based on cholinergically-mediated effects on regional brain connectivity and BOLD signal variability. Nine subjects participated in a double-blind, placebo-controlled crossover fMRI study. Following an infusion of physostigmine (1 mg/h) or placebo, echo-planar imaging (EPI) was conducted as participants performed a selective attention task. During the task, two images comprised of superimposed pictures of faces and houses were presented. Subjects were instructed periodically to shift their attention from one stimulus component to the other and to perform a matching task using hand held response buttons. A control condition included phase-scrambled images of superimposed faces and houses that were presented in the same temporal and spatial manner as the attention task; participants were instructed to perform a matching task. Cholinergic enhancement improved performance during the selective attention task, with no change during the control task. Functional connectivity analyses showed that the strength of connectivity between ventral visual processing areas and task-related occipital, parietal and prefrontal regions reduced significantly during cholinergic enhancement, exclusively during the selective attention task. Physostigmine administration also reduced BOLD signal temporal variability relative to placebo throughout temporal and occipital visual processing areas, again during the selective attention task only. Together with the observed behavioral improvement, the decreases in connectivity strength throughout task-relevant regions and BOLD variability within stimulus

  4. An event-related brain potential study of visual selective attention to conjunctions of color and shape.

    Science.gov (United States)

    Smid, H G; Jakob, A; Heinze, H J

    1999-03-01

    What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other conjunctions of these attributes in three discriminability conditions. Attending to color and shape produced three ERP effects: frontal selection positivity (FSP), central negativity (N2b), and posterior selection negativity (SN). The results suggested that the processes underlying SN and N2b perform independent within-dimension selections, whereas the process underlying the FSP performs hierarchical between-dimension selections. At posterior electrodes, manipulation of discriminability changed the ERPs to the relevant but not to the irrelevant stimuli, suggesting that the SN does not concern the selection process itself but rather a cognitive process initiated after selection is finished. Other findings suggested that selection of multiple visual attributes occurs in parallel.

  5. Visual Perception by Drivers of the Advertisements Located at Selected Major Routes

    Science.gov (United States)

    Bichajło, Lesław

    2017-10-01

    This article characterizes the research based on the analysis of the eye fixation points on the advertisements. The research has been realized in real road and traffic conditions. The group of 12 drivers was equipped with the glasses occulometric measurement system mounted on the driver’s head. The participants were driving their private cars. The analysis was concentrated on the fixations on the advertisement tables located along the selected national roads in Rzeszów area (Poland). For better recognition if the advertisements have distracted the drivers the number of fixations on the advertisements has been compared with the fixations on the road signs. The active drivers have observed many visual attractors like advertisements, road signs and cars being ahead and on another lane. Passive drivers have low number of fixations on road signs and advertisements. Their fixations typically have been localized on survey and they probably used the peripheral vision in order to recognition of road sign shapes. The results show, that: the percentage of fixations on the advertisement and road signs is different for each participants; the highest percentage of fixated advertisements was on the section with small number of advertisements, but in the city area, when a group of advertisements was on the road, the participants selected some of them, yet no participant fixated all advertisements localized in a small distance between them; the single advertisement visible from the long distance strongly attracts the visual perception; the percentage of the fixated advertisements was higher than road signs.

  6. Visual selective attention is impaired in children prenatally exposed to opioid agonist medication.

    Science.gov (United States)

    Konijnenberg, Carolien; Melinder, Annika

    2015-01-01

    To examine whether prenatal exposure to opioid agonist medication is associated with visual selective attention and general attention problems in early childhood. Twenty-two children (mean age = 52.17 months, SD = 1.81) prenatally exposed to methadone, 9 children (mean age = 52.41 months, SD = 1.42) prenatally exposed to buprenorphine and 25 nonexposed comparison children (mean age = 51.44 months, SD = 1.31) were tested. Visual selective attention was measured with a Tobii 1750 Eye Tracker using a spatial negative priming paradigm. Attention problems were measured using the Child Behavior Checklist. The comparison group demonstrated a larger spatial negative priming effect (mean = 23.50, SD = 45.50) than the exposed group [mean = -6.84, SD = 86.39, F(1,50) = 5.91, p = 0.019, η(2) = 0.11]. No difference in reported attention problems was found [F(1,51) = 1.63, p = 0.21, η(2) = 0.03]. Neonatal abstinence syndrome and prenatal exposure to marijuana were found to predict slower saccade latencies in the exposed group (b = 54.55, SE = 23.56, p = 0.03 and b = 88.86, SE = 32.07, p = 0.01, respectively). Although exposed children did not appear to have attention deficits in daily life, lower performance on the SNP task indicates subtle alteration in the attention system. © 2014 S. Karger AG, Basel.

  7. Modulation of human extrastriate visual processing by selective attention to colours and words.

    Science.gov (United States)

    Nobre, A C; Allison, T; McCarthy, G

    1998-07-01

    The present study investigated the effect of visual selective attention upon neural processing within functionally specialized regions of the human extrastriate visual cortex. Field potentials were recorded directly from the inferior surface of the temporal lobes in subjects with epilepsy. The experimental task required subjects to focus attention on words from one of two competing texts. Words were presented individually and foveally. Texts were interleaved randomly and were distinguishable on the basis of word colour. Focal field potentials were evoked by words in the posterior part of the fusiform gyrus. Selective attention strongly modulated long-latency potentials evoked by words. The attention effect co-localized with word-related potentials in the posterior fusiform gyrus, and was independent of stimulus colour. The results demonstrated that stimuli receive differential processing within specialized regions of the extrastriate cortex as a function of attention. The late onset of the attention effect and its co-localization with letter string-related potentials but not with colour-related potentials recorded from nearby regions of the fusiform gyrus suggest that the attention effect is due to top-down influences from downstream regions involved in word processing.

  8. Peptide-activated gold nanoparticles for selective visual sensing of virus

    Energy Technology Data Exchange (ETDEWEB)

    Sajjanar, Basavaraj; Kakodia, Bhuvna; Bisht, Deepika; Saxena, Shikha; Singh, Arvind Kumar [Indian Veterinary Research Institute, Division of Veterinary Biotechnology (India); Joshi, Vinay [Lala Lajpat Rai University of Veterinary & Animal Sciences, Department of Animal Biotechnology (India); Tiwari, Ashok Kumar; Kumar, Satish, E-mail: drsatishkumar-ivri@yahoo.co.in [Indian Veterinary Research Institute, Division of Veterinary Biotechnology (India)

    2015-05-15

    In this study, we report peptide–gold nanoparticles (AuNP)-based visual sensor for viruses. Citrate-stabilized AuNP (20 ± 1.9 nm) were functionalized with strong sulfur–gold interface using cysteinylated virus-specific peptide. Peptide–Cys–AuNP formed complexes with the viruses which made them to aggregate. The aggregation can be observed with naked eye and also with UV–Vis spectrophotometer as a color change from bright red to purple. The test allows for fast and selective detection of specific viruses. Spectroscopic measurements showed high linear correlation (R{sup 2} = 0.995) between the changes in optical density ratio (OD{sub 610}/OD{sub 520}) with the different concentrations of virus. The new method was compared with the hemagglutinating (HA) test for Newcastle disease virus (NDV). The results indicated that peptide–Cys–AuNP was more sensitive and can visually detect minimum number of virus particles present in the biological samples. The limit of detection for the NDV was 0.125 HA units of the virus. The method allows for selective detection and quantification of the NDV, and requires no isolation of viral RNA and PCR experiments. This strategy may be utilized for detection of other important human and animal viral pathogens.

  9. An independent brain-computer interface using covert non-spatial visual selective attention

    Science.gov (United States)

    Zhang, Dan; Maye, Alexander; Gao, Xiaorong; Hong, Bo; Engel, Andreas K.; Gao, Shangkai

    2010-02-01

    In this paper, a novel independent brain-computer interface (BCI) system based on covert non-spatial visual selective attention of two superimposed illusory surfaces is described. Perception of two superimposed surfaces was induced by two sets of dots with different colors rotating in opposite directions. The surfaces flickered at different frequencies and elicited distinguishable steady-state visual evoked potentials (SSVEPs) over parietal and occipital areas of the brain. By selectively attending to one of the two surfaces, the SSVEP amplitude at the corresponding frequency was enhanced. An online BCI system utilizing the attentional modulation of SSVEP was implemented and a 3-day online training program with healthy subjects was carried out. The study was conducted with Chinese subjects at Tsinghua University, and German subjects at University Medical Center Hamburg-Eppendorf (UKE) using identical stimulation software and equivalent technical setup. A general improvement of control accuracy with training was observed in 8 out of 18 subjects. An averaged online classification accuracy of 72.6 ± 16.1% was achieved on the last training day. The system renders SSVEP-based BCI paradigms possible for paralyzed patients with substantial head or ocular motor impairments by employing covert attention shifts instead of changing gaze direction.

  10. Neurons in the thalamic reticular nucleus are selective for diverse and complex visual features

    Science.gov (United States)

    Vaingankar, Vishal; Soto-Sanchez, Cristina; Wang, Xin; Sommer, Friedrich T.; Hirsch, Judith A.

    2012-01-01

    All visual signals the cortex receives are influenced by the perigeniculate sector (PGN) of the thalamic reticular nucleus, which receives input from relay cells in the lateral geniculate and provides feedback inhibition in return. Relay cells have been studied in quantitative depth; they behave in a roughly linear fashion and have receptive fields with a stereotyped center-surround structure. We know far less about reticular neurons. Qualitative studies indicate they simply pool ascending input to generate non-selective gain control. Yet the perigeniculate is complicated; local cells are densely interconnected and fire lengthy bursts. Thus, we employed quantitative methods to explore the perigeniculate using relay cells as controls. By adapting methods of spike-triggered averaging and covariance analysis for bursts, we identified both first and second order features that build reticular receptive fields. The shapes of these spatiotemporal subunits varied widely; no stereotyped pattern emerged. Companion experiments showed that the shape of the first but not second order features could be explained by the overlap of On and Off inputs to a given cell. Moreover, we assessed the predictive power of the receptive field and how much information each component subunit conveyed. Linear-non-linear (LN) models including multiple subunits performed better than those made with just one; further each subunit encoded different visual information. Model performance for reticular cells was always lesser than for relay cells, however, indicating that reticular cells process inputs non-linearly. All told, our results suggest that the perigeniculate encodes diverse visual features to selectively modulate activity transmitted downstream. PMID:23269915

  11. Visual encoding and fixation target selection in free viewing: presaccadic brain potentials

    Directory of Open Access Journals (Sweden)

    Andrey R Nikolaev

    2013-06-01

    Full Text Available In scrutinizing a scene, the eyes alternate between fixations and saccades. During a fixation, two component processes can be distinguished: visual encoding and selection of the next fixation target. We aimed to distinguish the neural correlates of these processes in the electrical brain activity prior to a saccade onset. Participants viewed color photographs of natural scenes, in preparation for a change detection task. Then, for each participant and each scene we computed an image heat map, with temperature representing the duration and density of fixations. The temperature difference between the start and end points of saccades was taken as a measure of the expected task-relevance of the information concentrated in specific regions of a scene. Visual encoding was evaluated according to whether subsequent change was correctly detected. Saccades with larger temperature difference were more likely to be followed by correct detection than ones with smaller temperature differences. The amplitude of presaccadic activity over anterior brain areas was larger for correct detection than for detection failure. This difference was observed for short scrutinizing but not for long explorative saccades, suggesting that presaccadic activity reflects top-down saccade guidance. Thus, successful encoding requires local scanning of scene regions which are expected to be task-relevant. Next, we evaluated fixation target selection. Saccades moving up in temperature were preceded by presaccadic activity of higher amplitude than those moving down. This finding suggests that presaccadic activity reflects attention deployed to the following fixation location. Our findings illustrate how presaccadic activity can elucidate concurrent brain processes related to the immediate goal of planning the next saccade and the larger-scale goal of constructing a robust representation of the visual scene.

  12. Top down and bottom up selection drives variations in frequency and form of a visual signal.

    Science.gov (United States)

    Yeh, Chien-Wei; Blamires, Sean J; Liao, Chen-Pan; Tso, I-Min

    2015-03-30

    The frequency and form of visual signals can be shaped by selection from predators, prey or both. When a signal simultaneously attracts predators and prey selection may favour a strategy that minimizes risks while attracting prey. Accordingly, varying the frequency and form of the silken decorations added to their web may be a way that Argiope spiders minimize predation while attracting prey. Nonetheless, the role of extraneous factors renders the influences of top down and bottom up selection on decoration frequency and form variation difficult to discern. Here we used dummy spiders and decorations to simulate four possible strategies that the spider Argiope aemula may choose and measured the prey and predator attraction consequences for each in the field. The strategy of decorating at a high frequency with a variable form attracted the most prey, while that of decorating at a high frequency with a fixed form attracted the most predators. These results suggest that mitigating the cost of attracting predators while maintaining prey attraction drives the use of variation in decoration form by many Argiope spp. when decorating frequently. Our study highlights the importance of considering top-down and bottom up selection pressure when devising evolutionary ecology experiments.

  13. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks.

    Science.gov (United States)

    Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

    2015-01-01

    Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

  14. Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

    Science.gov (United States)

    Moisala, Mona; Salmela, Viljami; Salo, Emma; Carlson, Synnöve; Vuontela, Virve; Salonen, Oili; Alho, Kimmo

    2015-01-01

    Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention. PMID:25745395

  15. Object selection costs in visual working memory: A diffusion model analysis of the focus of attention.

    Science.gov (United States)

    Sewell, David K; Lilburn, Simon D; Smith, Philip L

    2016-11-01

    A central question in working memory research concerns the degree to which information in working memory is accessible to other cognitive processes (e.g., decision-making). Theories assuming that the focus of attention can only store a single object at a time require the focus to orient to a target representation before further processing can occur. The need to orient the focus of attention implies that single-object accounts typically predict response time costs associated with object selection even when working memory is not full (i.e., memory load is less than 4 items). For other theories that assume storage of multiple items in the focus of attention, predictions depend on specific assumptions about the way resources are allocated among items held in the focus, and how this affects the time course of retrieval of items from the focus. These broad theoretical accounts have been difficult to distinguish because conventional analyses fail to separate components of empirical response times related to decision-making from components related to selection and retrieval processes associated with accessing information in working memory. To better distinguish these response time components from one another, we analyze data from a probed visual working memory task using extensions of the diffusion decision model. Analysis of model parameters revealed that increases in memory load resulted in (a) reductions in the quality of the underlying stimulus representations in a manner consistent with a sample size model of visual working memory capacity and (b) systematic increases in the time needed to selectively access a probed representation in memory. The results are consistent with single-object theories of the focus of attention. The results are also consistent with a subset of theories that assume a multiobject focus of attention in which resource allocation diminishes both the quality and accessibility of the underlying representations. (PsycINFO Database Record (c) 2016

  16. Spatiotemporal oscillatory dynamics of visual selective attention during a flanker task.

    Science.gov (United States)

    McDermott, Timothy J; Wiesman, Alex I; Proskovec, Amy L; Heinrichs-Graham, Elizabeth; Wilson, Tony W

    2017-08-01

    The flanker task is a test of visual selective attention that has been widely used to probe error monitoring, response conflict, and related constructs. However, to date, few studies have focused on the selective attention component of this task and imaged the underlying oscillatory dynamics serving task performance. In this study, 21 healthy adults successfully completed an arrow-based version of the Eriksen flanker task during magnetoencephalography (MEG). All MEG data were pre-processed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach, and voxel time series were extracted from the peak responses to identify the temporal dynamics. Across both congruent and incongruent flanker conditions, our results indicated robust decreases in alpha (9-12Hz) activity in medial and lateral occipital regions, bilateral parietal cortices, and cerebellar areas during task performance. In parallel, increases in theta (3-7Hz) oscillatory activity were detected in dorsal and ventral frontal regions, and the anterior cingulate. As per conditional effects, stronger alpha responses (i.e., greater desynchronization) were observed in parietal, occipital, and cerebellar cortices during incongruent relative to congruent trials, whereas the opposite pattern emerged for theta responses (i.e., synchronization) in the anterior cingulate, left dorsolateral prefrontal, and ventral prefrontal cortices. Interestingly, the peak latency of theta responses in these latter brain regions was significantly correlated with reaction time, and may partially explain the amplitude difference observed between congruent and incongruent trials. Lastly, whole-brain exploratory analyses implicated the frontal eye fields, right temporoparietal junction, and premotor cortices. These findings suggest that regions of both the dorsal and ventral attention networks contribute to visual selective attention processes during incongruent trials

  17. Exploring Visual Selective Attention towards Novel Stimuli in Alzheimer's Disease Patients

    Directory of Open Access Journals (Sweden)

    Sarah A. Chau

    2015-12-01

    Full Text Available Background: Alzheimer's disease (AD is associated with selective attention impairments, which could contribute to cognitive and functional deficits. Selective attention can be explored through examination of novelty preference. Aims: In this study, we quantified novelty preference in AD patients by measuring visual scanning behaviour using an eye tracking paradigm. Methods: Mild-to-moderate AD patients and elderly controls viewed slides containing novel and repeated images simultaneously. The outcome measure was time spent on specific images, with novelty preference defined by greater relative fixation time (RFT on novel versus repeated images. Cognitive status (Standardized Mini-Mental State Examination, SMMSE and attention (Digit Span, DS were also measured. Results: AD patients (age 79.2 ± 6.7 years, SMMSE 22.2 ± 4.0, n = 41 and controls (age 76.2 ± 6.4 years, SMMSE 28.1 ± 2.0, n = 24 were similar in age, education and sex. Compared with controls, AD patients had lower RFT on novel than on repeated images (F1,63 = 11.18, p = 0.001. Further, reduced RFT was associated with lower scores on SMMSE (r63 = 0.288, p = 0.020 and DS (r63 = 0.269, p = 0.030. Within individuals, novelty preference was detected in 92.3% of patients and in 100% of controls. Conclusion: These findings suggest that novelty preference, measured by visual scanning behaviour, can differentiate cognitively healthy and impaired people and may offer a nonverbal, less cognitively demanding method of assessing selective attention.

  18. Exploring Visual Selective Attention towards Novel Stimuli in Alzheimer's Disease Patients.

    Science.gov (United States)

    Chau, Sarah A; Herrmann, Nathan; Eizenman, Moshe; Chung, Jonathan; Lanctôt, Krista L

    2015-01-01

    Alzheimer's disease (AD) is associated with selective attention impairments, which could contribute to cognitive and functional deficits. Selective attention can be explored through examination of novelty preference. In this study, we quantified novelty preference in AD patients by measuring visual scanning behaviour using an eye tracking paradigm. Mild-to-moderate AD patients and elderly controls viewed slides containing novel and repeated images simultaneously. The outcome measure was time spent on specific images, with novelty preference defined by greater relative fixation time (RFT) on novel versus repeated images. Cognitive status (Standardized Mini-Mental State Examination, SMMSE) and attention (Digit Span, DS) were also measured. AD patients (age 79.2 ± 6.7 years, SMMSE 22.2 ± 4.0, n = 41) and controls (age 76.2 ± 6.4 years, SMMSE 28.1 ± 2.0, n = 24) were similar in age, education and sex. Compared with controls, AD patients had lower RFT on novel than on repeated images (F1,63 = 11.18, p = 0.001). Further, reduced RFT was associated with lower scores on SMMSE (r63 = 0.288, p = 0.020) and DS (r63 = 0.269, p = 0.030). Within individuals, novelty preference was detected in 92.3% of patients and in 100% of controls. These findings suggest that novelty preference, measured by visual scanning behaviour, can differentiate cognitively healthy and impaired people and may offer a nonverbal, less cognitively demanding method of assessing selective attention.

  19. Estimating the variation, autocorrelation, and environmental sensitivity of phenotypic selection

    NARCIS (Netherlands)

    Chevin, Luis-Miguel; Visser, Marcel E.; Tufto, Jarle

    2015-01-01

    Despite considerable interest in temporal and spatial variation of phenotypic selection, very few methods allow quantifying this variation while correctly accounting for the error variance of each individual estimate. Furthermore, the available methods do not estimate the autocorrelation of

  20. Estimating the variation, autocorrelation, and environmental sensitivity of phenotypic selection

    NARCIS (Netherlands)

    Chevin, Luis-Miguel; Visser, Marcel E.; Tufto, Jarle

    Despite considerable interest in temporal and spatial variation of phenotypic selection, very few methods allow quantifying this variation while correctly accounting for the error variance of each individual estimate. Furthermore, the available methods do not estimate the autocorrelation of

  1. Indoor Environmental Conditions and Sanitary Practices in Selected ...

    African Journals Online (AJOL)

    Rapidly urbanizing cities are witnessing an increase in Day care centres (DCCs) whose environmental conditions are substandard. This scenario has negative consequences on the health of the DCC attendees and yet information on some of the indicators such as the level of sanitary practices is not adequately ...

  2. Selection of culturable environmental microbial strains for cellular ...

    African Journals Online (AJOL)

    Environmental pollution by organic compounds is a global problem. Biological treatment methods are used to restore polluted environments. Microbial immobilization on abiotic surfaces is a recent strategy to improve the efficiency of these processes. In this technique, cell adhesion is a fundamental step for subsequent ...

  3. Semantic Wavelet-Induced Frequency-Tagging (SWIFT Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas.

    Directory of Open Access Journals (Sweden)

    Roger Koenig-Robert

    Full Text Available Primate visual systems process natural images in a hierarchical manner: at the early stage, neurons are tuned to local image features, while neurons in high-level areas are tuned to abstract object categories. Standard models of visual processing assume that the transition of tuning from image features to object categories emerges gradually along the visual hierarchy. Direct tests of such models remain difficult due to confounding alteration in low-level image properties when contrasting distinct object categories. When such contrast is performed in a classic functional localizer method, the desired activation in high-level visual areas is typically accompanied with activation in early visual areas. Here we used a novel image-modulation method called SWIFT (semantic wavelet-induced frequency-tagging, a variant of frequency-tagging techniques. Natural images modulated by SWIFT reveal object semantics periodically while keeping low-level properties constant. Using functional magnetic resonance imaging (fMRI, we indeed found that faces and scenes modulated with SWIFT periodically activated the prototypical category-selective areas while they elicited sustained and constant responses in early visual areas. SWIFT and the localizer were selective and specific to a similar extent in activating category-selective areas. Only SWIFT progressively activated the visual pathway from low- to high-level areas, consistent with predictions from standard hierarchical models. We confirmed these results with criterion-free methods, generalizing the validity of our approach and show that it is possible to dissociate neural activation in early and category-selective areas. Our results provide direct evidence for the hierarchical nature of the representation of visual objects along the visual stream and open up future applications of frequency-tagging methods in fMRI.

  4. Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

    Science.gov (United States)

    Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

    2015-01-01

    Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

  5. Impact of sleep inertia on visual selective attention for rare targets and the influence of chronotype.

    Science.gov (United States)

    Ritchie, Hannah K; Burke, Tina M; Dear, Tristan B; Mchill, Andrew W; Axelsson, John; Wright, Kenneth P

    2017-10-01

    Sleep inertia is affected by circadian phase, with worse performance upon awakening from sleep during the biological night than biological day. Visual search/selective visual attention performance is known to be sensitive to sleep inertia and circadian phase. Individual differences exist in the circadian timing of habitual wake time, which may contribute to individual differences in sleep inertia. Because later chronotypes awaken at an earlier circadian phase, we hypothesized that later chronotypes would have worse visual search performance during sleep inertia than earlier chronotypes if awakened at habitual wake time. We analysed performance from 18 healthy participants [five females (22.1 ± 3.7 years; mean ± SD)] at ~1, 10, 20, 30, 40 and 60 min following electroencephalogram-verified awakening from an 8 h in-laboratory sleep opportunity. Cognitive throughput and reaction times of correct responses were impaired by sleep inertia and took ~10-30 min to improve after awakening. Regardless whether chronotype was defined by dim light melatonin onset or mid-sleep clock hour on free days, derived from the Munich ChronoType Questionnaire, the duration of sleep inertia for cognitive throughput and reaction times was longer for later chronotypes (n = 7) compared with earlier chronotypes (n = 7). Specifically, performance for earlier chronotypes showed significant improvement within ~10-20 min after awakening, whereas performance for later chronotypes took ~30 min or longer to show significant improvement (P inertia contributes to longer-lasting impairments in morning performance in later chronotypes. © 2017 European Sleep Research Society.

  6. Age-related slowing of response selection and production in a visual choice reaction time task

    Directory of Open Access Journals (Sweden)

    David L Woods

    2015-04-01

    Full Text Available Aging is associated with delayed processing in choice reaction time (CRT tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40% by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each, by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year. Central processing time (CPT, isolated by subtracting simple reaction times (obtained in a companion experiment performed on the same day from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18-82 years. CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and

  7. Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

    Science.gov (United States)

    Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

    2003-01-01

    To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

  8. Environmental aspects of the transuranics: a selected, annotated bibliography

    International Nuclear Information System (INIS)

    Fore, C.S.; Martin, F.M.; Faust, R.A.

    1976-07-01

    This bibliography of 500 references is compiled from the Data Base on the Environmental Aspects of the Transuranics built to provide information support to the Nevada Applied Ecology Group (NAEG) of ERDA's Nevada Operations Office. The general scope is environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. Laboratory and field studies dealing with the effects of plutonium-239 on animals are highlighted in this bibliography. Supporting information on ecology of the Nevada Test Site and reviews on the effects of other radionuclides upon man and his environment has been included at the request of the NAEG. The references are arranged by subject category with first authors appearing alphabetically in each category. Indexes are given for author, geographic location, keywords, taxons, permuted title and publication description

  9. Environmental aspects of the transuranics: a selected, annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Fore, C.S.; Martin, F.M.; Faust, R.A. (comp.)

    1976-07-01

    This bibliography of 500 references is compiled from the Data Base on the Environmental Aspects of the Transuranics built to provide information support to the Nevada Applied Ecology Group (NAEG) of ERDA`s Nevada Operations Office. The general scope is environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. Laboratory and field studies dealing with the effects of plutonium-239 on animals are highlighted in this bibliography. Supporting information on ecology of the Nevada Test Site and reviews on the effects of other radionuclides upon man and his environment has been included at the request of the NAEG. The references are arranged by subject category with first authors appearing alphabetically in each category. Indexes are given for author, geographic location, keywords, taxons, permuted title and publication description.

  10. Selecting protein families for environmental features based on manifold regularization.

    Science.gov (United States)

    Jiang, Xingpeng; Xu, Weiwei; Park, E K; Li, Guangrong

    2014-06-01

    Recently, statistics and machine learning have been developed to identify functional or taxonomic features of environmental features or physiological status. Important proteins (or other functional and taxonomic entities) to environmental features can be potentially used as biosensors. A major challenge is how the distribution of protein and gene functions embodies the adaption of microbial communities across environments and host habitats. In this paper, we propose a novel regularization method for linear regression to adapt the challenge. The approach is inspired by local linear embedding (LLE) and we call it a manifold-constrained regularization for linear regression (McRe). The novel regularization procedure also has potential to be used in solving other linear systems. We demonstrate the efficiency and the performance of the approach in both simulation and real data.

  11. Environmental aspects of the transuranics: a selected, annotated bibliography

    International Nuclear Information System (INIS)

    Ensminger, J.T.; Martin, F.M.; Fore, C.S.

    1977-03-01

    This eighth published bibliography of 427 references is compiled from the Nevada Applied Ecology Information Center's Data Base on the Environmental Aspects of the Transuranics. The data base was built to provide information support to the Nevada Applied Ecology Group (NAEG) of ERDA's Nevada Operations Office. The general scope covers environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. This bibliography highlights literature on plutonium 238 and 239 and americium in the critical organs of man and animals. Supporting information on ecology of the Nevada Test Site and reviews and summarizing literature on other radionuclides have been included at the request of the NAEG. The references are arranged by subject category with leading authors appearing alphabetically in each category. Indexes are provided for author(s), geographic location, keyword(s), taxon, title, and publication description

  12. Detecting effects of donepezil on visual selective attention using signal detection parameters in Alzheimer's disease.

    Science.gov (United States)

    Foldi, Nancy S; White, Richard E C; Schaefer, Lynn A

    2005-05-01

    Attentional function is impaired in Alzheimer's disease (AD). Moreover, attention is mediated by acetylcholine. But, despite the widespread use of acetylcholinesterase inhibitors (AChE-I) to augment available acetylcholine in AD, measures of attentional function have not been used to assess the drug response. We hypothesized that as cholinergic augmentation impacts directly on the attentional system, higher-order measures of visual selective attention would be sensitive to effects of treatment using an AChE-I (donepezil hydrochloride). We also sought to determine whether these attentional measures were more sensitive to treatment than other measures of cognitive function. Seventeen patients with AD (8 untreated, 9 treated with donepezil) were contrasted on performance of a selective cancellation task. Two signal detection parameters were used as outcome measures: decision strategy (beta, beta) and discriminability (d-prime, d'). Standard screening and cognitive domain measures of vigilance, language, memory, and executive function were also contrasted. Treated patients judged stimuli more conservatively (p = 0.29) by correctly endorsing targets and rejecting false alarms. They also discriminated targets from distractors more easily (p = 0.58). The screening and neuropsychological measures failed to differentiate the groups. Higher-order attentional measures captured the effects of donepezil treatment in small groups of patients with AD. The results suggest that cholinergic availability may directly affect the attentional system, and that these selective attention measures are sensitive markers to detect treatment response. Copyright 2005 John Wiley & Sons, Ltd.

  13. Understanding, Classifying, and Selecting Environmentally Acceptable Hydraulic Fluids

    Science.gov (United States)

    2016-08-01

    traditional mineral oil; therefore, the life cycle costs over time may be reduced . REPLACEMENT OF EXISTING HYDRAULIC FLUIDS: Hydraulic fluids in existing...properly maintaining the fluid can extend the time interval between fluid changes, thus reducing the overall operating cost of the EA hydraulic fluid. It...Environmentally Acceptable Hydraulic Fluids by Timothy J. Keyser, Robert N. Samuel, and Timothy L. Welp INTRODUCTION: On a daily basis, the United States Army

  14. Selection of bioaccumulation criteria for environmental emergency (E2) planning

    International Nuclear Information System (INIS)

    Ketcheson, K.; Hradecky, K.; Gagne, M.; St-Amant-Verret, M.

    2006-01-01

    Environment Canada's Environmental Emergency regulations require the evaluation of a substance by a Risk Evaluation Framework (REF). Bioaccumulation criteria are used within the environmental hazard ratings section of the REF to determine the risk of a substance to organisms and are obtained from 3 types of measurements depending on data reliability: (1) bioaccumulation factors (BAF); (2) bioconcentration factors (BCF); and (3) an octanol-water partition coefficient (log K ow ). This paper presented details of a study of international and regional bioaccumulation criteria conducted to aid in determining appropriate criteria for E2 regulations and plans, with specific reference to substances toxic to aquatic organisms. An E2 plan is required if a substance has a bioconcentration factor of more than 500 in conjunction with aquatic toxicity. Bioaccumulation criteria from several sources for 745 substances were obtained to aid in choosing the most important parameters. Various international and regional criteria were examined and corresponding sources were summarized, and different source criteria was compared with empirical chemical data. The criteria chosen included both log K ow values and BCF values, although it was suggested that BCF and BAF are more realistic measures of bioaccumulation than log K ow , as they are derived from animal studies. The chosen values agreed with the virtual elimination criteria set out by the Canadian Environmental Protection Act (CEPA) 1999 as well as United States Environmental Protection Agency (EPA) criteria. It was concluded that the bioaccumulation criteria for E2 planning will help Environment Canada ensure the protection of the environment from hazardous substances. 11 refs., 3 tabs., 5 figs

  15. Environmental Resources of Selected Areas of Hawaii: Ecological Resources (DRAFT)

    Energy Technology Data Exchange (ETDEWEB)

    Trettin, C.C.; Tolbert, V.R.; Jones, A.T.; Smith, C.R.; Kalmijn, A.J.

    1994-06-01

    This report has been prepared to make available and archive the background scientific data and related information collected on ecological resources during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The U.S. Department of Energy (COE) published a notice in the Federal Register on May 17, 1994 (Fed. Regist. 5925638) withdrawing its Notice of Intent (Fed. Regst. 575433) of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The background scientific data and related information presented in this report focus on several areas of Hawaii County, including the southeastern coast, a potential development corridor along the Saddle Road between Hilo and the North Kohala District on the northwestern coast, and on the southeastern coast of Maui. In this report, reference is made to these areas as study areas rather than as areas where proposed or alternative facilities of the HGP would be located. The resource areas addressed herein include terrestrial ecology, aquatic ecology, and marine ecology. The scientific background data and related information is being made available for future research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  16. Visualizing Earth Science Data for Environmental Monitoring and Decision Support in Mesoamerica: The SERVIR Project

    Science.gov (United States)

    Hardin, D.; Graves, S.; Sever, T.; Irwin, D.

    2005-05-01

    In 2002 and 2003 NASA, the World Bank and the United States Agency for International Development (USAID) joined with the Central American Commission for Environment and Development (CCAD) to develop an advanced decision support system for Mesoamerica (named SERVIR). Mesoamerica - composed of the seven Central American countries and the five southernmost states of Mexico - makes up only a small fraction of the world's land surface. However, the region is home to approximately eight percent of the planet's biodiversity (14 biosphere reserves, 31 Ramsar sites, 8 world heritage sites, 589 protected areas) and 45 million people including more than 50 different ethnic groups. Mesoamerica's biological and cultural diversity are severely threatened by human impact and natural disasters including extensive deforestation, illegal logging, water pollution, slash and burn agriculture, earthquakes, hurricanes, drought, and volcanic eruption. NASA Marshall Space Flight Center (NASA/MSFC), together with the University of Alabama in Huntsville (UAH) and the SERVIR partners are developing state-of-the-art decision support tools for environmental monitoring as well as disaster prevention and mitigation in Mesoamerica. These partners are contributing expertise in space-based observation with information management technologies and intimate knowledge of local ecosystems to create a system that is being used by scientists, educators, and policy makers to monitor and forecast ecological changes, respond to natural disasters, and better understand both natural and human induced effects. The decision support and environmental monitoring data products are typically formatted as conventional two-dimensional, static and animated imagery. However, in addition to conventional data products and as a major portion of our research, we are employing commercial applications that generate three-dimensional interactive visualizations that allow data products to be viewed from multiple angles and at

  17. Nuclear site selection and environmental protection. The decision making methods

    International Nuclear Information System (INIS)

    Bresson, G.; Lacourly, G.; Fitoussi, L.

    1975-01-01

    The selection of the site of a nuclear plant most often comes to seek out and compound between two trends: that of the operator who will try and reduce the cost price of his product to the lowest and that of the protectionist who will try and reduce to the minimum the hazards resulting from the plant operation. Such a compromise is the result of a more or less empirical choice, which enters within the frame of a cost-benefit analysis, in which theoretically, the choice between several possible solutions is made of the selection giving the higher advantage [fr

  18. TOUCH INTERACTION WITH 3D GEOGRAPHICAL VISUALIZATION ON WEB: SELECTED TECHNOLOGICAL AND USER ISSUES

    Directory of Open Access Journals (Sweden)

    L. Herman

    2016-10-01

    Full Text Available The use of both 3D visualization and devices with touch displays is increasing. In this paper, we focused on the Web technologies for 3D visualization of spatial data and its interaction via touch screen gestures. At the first stage, we compared the support of touch interaction in selected JavaScript libraries on different hardware (desktop PCs with touch screens, tablets, and smartphones and software platforms. Afterward, we realized simple empiric test (within-subject design, 6 participants, 2 simple tasks, LCD touch monitor Acer and digital terrain models as stimuli focusing on the ability of users to solve simple spatial tasks via touch screens. An in-house testing web tool was developed and used based on JavaScript, PHP, and X3DOM languages and Hammer.js libraries. The correctness of answers, speed of users’ performances, used gestures, and a simple gesture metric was recorded and analysed. Preliminary results revealed that the pan gesture is most frequently used by test participants and it is also supported by the majority of 3D libraries. Possible gesture metrics and future developments including the interpersonal differences are discussed in the conclusion.

  19. Divisive normalization and neuronal oscillations in a single hierarchical framework of selective visual attention

    Directory of Open Access Journals (Sweden)

    Jorrit Steven Montijn

    2012-05-01

    Full Text Available In divisive normalization models of covert attention, spike rate modulations are commonly used as indicators of the effect of top-down attention. In addition, an increasing number of studies have shown that top-down attention increases the synchronization of neuronal oscillations as well, particularly those in gamma-band frequencies (25 to 100 Hz. Although modulations of spike rate and synchronous oscillations are not mutually exclusive as mechanisms of attention, there has thus far been little effort to integrate these concepts into a single framework of attention. Here, we aim to provide such a unified framework by expanding the normalization model of attention with a time dimension; allowing the simulation of a recently reported backward progression of attentional effects along the visual cortical hierarchy. A simple hierarchical cascade of normalization models simulating different cortical areas however leads to signal degradation and a loss of discriminability over time. To negate this degradation and ensure stable neuronal stimulus representations, we incorporate oscillatory phase entrainment into our model, a mechanism previously proposed as the communication-through-coherence (CTC hypothesis. Our analysis shows that divisive normalization and oscillation models can complement each other in a unified account of the neural mechanisms of selective visual attention. The resulting hierarchical normalization and oscillation (HNO model reproduces several additional spatial and temporal aspects of attentional modulation.

  20. Transcranial magnetic stimulation changes response selectivity of neurons in the visual cortex

    Science.gov (United States)

    Kim, Taekjun; Allen, Elena A.; Pasley, Brian N.; Freeman, Ralph D.

    2015-01-01

    Background Transcranial magnetic stimulation (TMS) is used to selectively alter neuronal activity of specific regions in the cerebral cortex. TMS is reported to induce either transient disruption or enhancement of different neural functions. However, its effects on tuning properties of sensory neurons have not been studied quantitatively. Objective/Hypothesis Here, we use specific TMS application parameters to determine how they may alter tuning characteristics (orientation, spatial frequency, and contrast sensitivity) of single neurons in the cat’s visual cortex. Methods Single unit spikes were recorded with tungsten microelectrodes from the visual cortex of anesthetized and paralyzed cats (12 males). Repetitive TMS (4Hz, 4sec) was delivered with a 70mm figure-8 coil. We quantified basic tuning parameters of individual neurons for each pre- and post-TMS condition. The statistical significance of changes for each tuning parameter between the two conditions was evaluated with a Wilcoxon signed-rank test. Results We generally find long-lasting suppression which persists well beyond the stimulation period. Pre- and post-TMS orientation tuning curves show constant peak values. However, strong suppression at non-preferred orientations tends to narrow the widths of tuning curves. Spatial frequency tuning exhibits an asymmetric change in overall shape, which results in an emphasis on higher frequencies. Contrast tuning curves show nonlinear changes consistent with a gain control mechanism. Conclusions These findings suggest that TMS causes extended interruption of the balance between sub-cortical and intra-cortical inputs. PMID:25862599

  1. Divisive normalization and neuronal oscillations in a single hierarchical framework of selective visual attention.

    Science.gov (United States)

    Montijn, Jorrit Steven; Klink, P Christaan; van Wezel, Richard J A

    2012-01-01

    Divisive normalization models of covert attention commonly use spike rate modulations as indicators of the effect of top-down attention. In addition, an increasing number of studies have shown that top-down attention increases the synchronization of neuronal oscillations as well, particularly in gamma-band frequencies (25-100 Hz). Although modulations of spike rate and synchronous oscillations are not mutually exclusive as mechanisms of attention, there has thus far been little effort to integrate these concepts into a single framework of attention. Here, we aim to provide such a unified framework by expanding the normalization model of attention with a multi-level hierarchical structure and a time dimension; allowing the simulation of a recently reported backward progression of attentional effects along the visual cortical hierarchy. A simple cascade of normalization models simulating different cortical areas is shown to cause signal degradation and a loss of stimulus discriminability over time. To negate this degradation and ensure stable neuronal stimulus representations, we incorporate a kind of oscillatory phase entrainment into our model that has previously been proposed as the "communication-through-coherence" (CTC) hypothesis. Our analysis shows that divisive normalization and oscillation models can complement each other in a unified account of the neural mechanisms of selective visual attention. The resulting hierarchical normalization and oscillation (HNO) model reproduces several additional spatial and temporal aspects of attentional modulation and predicts a latency effect on neuronal responses as a result of cued attention.

  2. What Are the Environmental Determinants of Phenotypic Selection? A Meta-analysis of Experimental Studies.

    Science.gov (United States)

    Caruso, Christina M; Martin, Ryan A; Sletvold, Nina; Morrissey, Michael B; Wade, Michael J; Augustine, Kate E; Carlson, Stephanie M; MacColl, Andrew D C; Siepielski, Adam M; Kingsolver, Joel G

    2017-09-01

    Although many selection estimates have been published, the environmental factors that cause selection to vary in space and time have rarely been identified. One way to identify these factors is by experimentally manipulating the environment and measuring selection in each treatment. We compiled and analyzed selection estimates from experimental studies. First, we tested whether the effect of manipulating the environment on selection gradients depends on taxon, trait type, or fitness component. We found that the effect of manipulating the environment was larger when selection was measured on life-history traits or via survival. Second, we tested two predictions about the environmental factors that cause variation in selection. We found support for the prediction that variation in selection is more likely to be caused by environmental factors that have a large effect on mean fitness but not for the prediction that variation is more likely to be caused by biotic factors. Third, we compared selection gradients from experimental and observational studies. We found that selection varied more among treatments in experimental studies than among spatial and temporal replicates in observational studies, suggesting that experimental studies can detect relationships between environmental factors and selection that would not be apparent in observational studies.

  3. Visual discrimination in the pigeon (Columba livia): effects of selective lesions of the nucleus rotundus

    Science.gov (United States)

    Laverghetta, A. V.; Shimizu, T.

    1999-01-01

    The nucleus rotundus is a large thalamic nucleus in birds and plays a critical role in many visual discrimination tasks. In order to test the hypothesis that there are functionally distinct subdivisions in the nucleus rotundus, effects of selective lesions of the nucleus were studied in pigeons. The birds were trained to discriminate between different types of stationary objects and between different directions of moving objects. Multiple regression analyses revealed that lesions in the anterior, but not posterior, division caused deficits in discrimination of small stationary stimuli. Lesions in neither the anterior nor posterior divisions predicted effects in discrimination of moving stimuli. These results are consistent with a prediction led from the hypothesis that the nucleus is composed of functional subdivisions.

  4. Moving attention - Evidence for time-invariant shifts of visual selective attention

    Science.gov (United States)

    Remington, R.; Pierce, L.

    1984-01-01

    Two experiments measured the time to shift spatial selective attention across the visual field to targets 2 or 10 deg from central fixation. A central arrow cued the most likely target location. The direction of attention was inferred from reaction times to expected, unexpected, and neutral locations. The development of a spatial attentional set with time was examined by presenting target probes at varying times after the cue. There were no effects of distance on the time course of the attentional set. Reaction times for far locations were slower than for near, but the effects of attention were evident by 150 msec in both cases. Spatial attention does not shift with a characteristic, fixed velocity. Rather, velocity is proportional to distance, resulting in a movement time that is invariant over the distances tested.

  5. Using visual language to represent interdisciplinary content in urban development: Selected findings

    Directory of Open Access Journals (Sweden)

    Špela Verovšek

    2013-01-01

    Full Text Available This article addresses visual language in architecture and spatial disciplines, using it as a means of communicating and conveying information, knowledge and ideas about space that are permeated by their interdisciplinary character. We focus in particular on the transmission of messages between professionals and the general public, arguing that this process aids the long-term formation of a responsible and critical public, which is then able to take an active part in sustainable planning and design practices. The article highlights some findings of an empirical study of 245 people that tested the effectiveness of selected presentation techniques in communicating spatial messages to the general public and placing them in the framework of existing knowledge.

  6. Izbrani kazalci obremenjenosti okolja pri študijah ranljivosti okolja = Selected environmental pollution indicators in environmental vulnerability studies

    Directory of Open Access Journals (Sweden)

    Dejan Cigale

    2002-01-01

    Full Text Available One of the components of the environmentalvulnerability studies is also the evaluation of the pollution of theenvironment. In the article, the analysis of the selected indicators of theachieved degree of the total and integral pollution is presented. In theframework of the environmental vulnerability studies on the spatial levelof landscape-ecological types for this purpose the following indicatorswere selected: population density, density of working places, trafficintensity and percentage of forests.

  7. Web mapping system for complex processing and visualization of environmental geospatial datasets

    Science.gov (United States)

    Titov, Alexander; Gordov, Evgeny; Okladnikov, Igor

    2016-04-01

    Environmental geospatial datasets (meteorological observations, modeling and reanalysis results, etc.) are used in numerous research applications. Due to a number of objective reasons such as inherent heterogeneity of environmental datasets, big dataset volume, complexity of data models used, syntactic and semantic differences that complicate creation and use of unified terminology, the development of environmental geodata access, processing and visualization services as well as client applications turns out to be quite a sophisticated task. According to general INSPIRE requirements to data visualization geoportal web applications have to provide such standard functionality as data overview, image navigation, scrolling, scaling and graphical overlay, displaying map legends and corresponding metadata information. It should be noted that modern web mapping systems as integrated geoportal applications are developed based on the SOA and might be considered as complexes of interconnected software tools for working with geospatial data. In the report a complex web mapping system including GIS web client and corresponding OGC services for working with geospatial (NetCDF, PostGIS) dataset archive is presented. There are three basic tiers of the GIS web client in it: 1. Tier of geospatial metadata retrieved from central MySQL repository and represented in JSON format 2. Tier of JavaScript objects implementing methods handling: --- NetCDF metadata --- Task XML object for configuring user calculations, input and output formats --- OGC WMS/WFS cartographical services 3. Graphical user interface (GUI) tier representing JavaScript objects realizing web application business logic Metadata tier consists of a number of JSON objects containing technical information describing geospatial datasets (such as spatio-temporal resolution, meteorological parameters, valid processing methods, etc). The middleware tier of JavaScript objects implementing methods for handling geospatial

  8. Incorporation of environmental costs in electric utility planning and resource selection

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Generation of electricity is pervasively regulated for economic, environmental and other governmental objectives at both the state and federal levels. A panoply of legislative and regulatory devices implicitly or explicitly influence the acquisition of generation and fuel resources seeking to achieve environmentally sound selections. Effective implementation or enforcement of these laws and policies may be impeded by the regional or global character of the environmental impacts; jurisdictional conflicts and limitations; and the division of regulatory authority between economic regulatory agencies and their environmental or energy policy counterparts. This chapter reviews the state and federal statutory and regulatory treatment of environmental externalities and discusses alternatives for their consideration

  9. The Effects of an Environmental Studies Course on Selected Variables Related To Environmentally Responsible Behavior.

    Science.gov (United States)

    Smith-Sebasto, N. J.

    1995-01-01

    Reports that students completing an environmental studies course displayed significant gains when compared with students not completing such a course. These gains were made in acquiring a more internally-oriented locus of control of reinforcement for environmentally responsible behavior, a higher perception of their knowledge of and skill in using…

  10. Environmental resources of selected areas of Hawaii: Socioeconomics

    Energy Technology Data Exchange (ETDEWEB)

    Saulsbury, J.W.; Sorensen, B.M.; Reed, R.M. [Oak Ridge National Lab., TN (United States); Schexnayder, S.M. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-03-01

    This report has been prepared to make available and archive the background information on socioeconomic resources collected during the preparation of the environmental impact statement (EIS) for Phases 3--4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The USDOE published a notice withdrawing its Notice of Intent to prepare the HGP EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. This document provides background information on socioeconomic resources in Hawaii County, with particular emphasis on the Puna District. Information is being made available for use by others in conducting future socioeconomic impact assessments in this area. this report describes existing socioeconomic resources in the areas studied and does not represent an assessment of environmental impacts. The socioeconomic resources described are primarily those that would be affected by employment and population growth associated with any future large-scale development. These resource categories are population, housing, land use, economic structure, infrastructure and public services, local government revenues and expenditures, and tourism and recreation.

  11. Environmental Resources of Selected Areas of Hawaii: Socioeconomics (DRAFT)

    Energy Technology Data Exchange (ETDEWEB)

    Saulsbury, J.W.; Sorensen, B.M.; Schexnayder, S.M.

    1994-06-01

    This report has been prepared to make available and archive the background information on socioeconomic resources collected during the preparation of the Environmental Impact Statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The U.S. Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 (Fed. Regis. 5925638), withdrawing its Notice of Intent (Fed Regis. 57:5433), of February 14, 1992, to prepare the HGPEIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. This document provides background information on socioeconomic resources in Hawaii County, with particular emphasis on the Puna District (Fig. 1). Information is being made available for use by others in conducting future socioeconomic impact assessments in this area. This report describes existing socioeconomic resources in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts. The socioeconomic resources described are primarily those that would be affected by employment and population growth associated with any future large-scale development. These resource categories are (1) population, (2) housing, (3) land use, (4) economic structure (primarily employment and income), (5) infrastructure and public services (education, ground transportation, police and fire protection, water, wastewater, solid waste disposal, electricity, and emergency planning), (6) local government revenues and expenditures, and (7) tourism and recreation.

  12. Environmental resources of selected areas of Hawaii: Geological hazards

    Energy Technology Data Exchange (ETDEWEB)

    Staub, W.P.; Reed, R.M.

    1995-03-01

    This report has been prepared to make available and archive the background scientific data and related information collected on geologic hazards during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice withdrawing its Notice of Intent to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. This report presents a review of current information on geologic hazards in the Hawaiian Islands. Interrelationships among these hazards are discussed. Probabilities of occurrence of given geologic hazards are provided in various regions where sufficient geologic or historical data are available. Most of the information contained herein is compiled from recent US Geological Survey (USGS) publications and USGS open-file reports related to this project. This report describes the natural geologic hazards present in the area and does not represent an assessment of environmental impacts. Geologic hazards originate both onshore and offshore. Onshore geologic hazards such as volcanic eruptions, earthquakes, surface rupture, landslides, uplift and subsidence occur mainly on the southern third of the island of Hawaii (hereinafter referred to as Hawaii). Offshore geologic hazards are more widely distributed throughout the Hawaiian Islands. Examples of offshore geologic hazards are submarine landslides, turbidity currents, and seismic sea waves (tsunamis).

  13. Selectivity and direct visualization of carbon dioxide and sulfur dioxide in a decorated porous host

    Science.gov (United States)

    Yang, Sihai; Sun, Junliang; Ramirez-Cuesta, Anibal J.; Callear, Samantha K.; David, William I. F.; Anderson, Daniel P.; Newby, Ruth; Blake, Alexander J.; Parker, Julia E.; Tang, Chiu C.; Schröder, Martin

    2012-11-01

    Understanding the mechanism by which porous solids trap harmful gases such as CO2 and SO2 is essential for the design of new materials for their selective removal. Materials functionalized with amine groups dominate this field, largely because of their potential to form carbamates through H2N(δ-)···C(δ+)O2 interactions, thereby trapping CO2 covalently. However, the use of these materials is energy-intensive, with significant environmental impact. Here, we report a non-amine-containing porous solid (NOTT-300) in which hydroxyl groups within pores bind CO2 and SO2 selectively. In situ powder X-ray diffraction and inelastic neutron scattering studies, combined with modelling, reveal that hydroxyl groups bind CO2 and SO2 through the formation of O=C(S)=O(δ-)···H(δ+)-O hydrogen bonds, which are reinforced by weak supramolecular interactions with C-H atoms on the aromatic rings of the framework. This offers the potential for the application of new ‘easy-on/easy-off’ capture systems for CO2 and SO2 that carry fewer economic and environmental penalties.

  14. Evaluation of uncertainties in selected environmental dispersion models

    International Nuclear Information System (INIS)

    Little, C.A.; Miller, C.W.

    1979-01-01

    Compliance with standards of radiation dose to the general public has necessitated the use of dispersion models to predict radionuclide concentrations in the environment due to releases from nuclear facilities. Because these models are only approximations of reality and because of inherent variations in the input parameters used in these models, their predictions are subject to uncertainty. Quantification of this uncertainty is necessary to assess the adequacy of these models for use in determining compliance with protection standards. This paper characterizes the capabilities of several dispersion models to predict accurately pollutant concentrations in environmental media. Three types of models are discussed: aquatic or surface water transport models, atmospheric transport models, and terrestrial and aquatic food chain models. Using data published primarily by model users, model predictions are compared to observations

  15. Environmental aspects of the transuranics. A selected, annotated bibliography

    International Nuclear Information System (INIS)

    Martin, F.M.; Faust, R.A.; Sanders, C.T.

    1975-07-01

    This bibliography of 470 references is from the computer file built to provide information support to the Nevada Applied Ecology Group (NAEG) of ERDA's Nevada Operations Office. The general scope is environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. Biological aspects of the transuranics is highlighted in this bibliography. In addition, supporting materials involving basic ecology studies, ecology of the Nevada Test Site, and reviews on other radionuclides are entered at the request of the NAEG. Significant numeric data is shown in tabular display or is noted for reference to the original document. The references are arranged by subject category with first authors arranged alphabetically within the category. Indexes are given for author, keywords, geographic location, permuted title, taxons, and publication description. (U.S.)

  16. Analysis of selected phytotoxins and mycotoxins in environmental samples.

    Science.gov (United States)

    Hoerger, Corinne C; Schenzel, Judith; Strobel, Bjarne W; Bucheli, Thomas D

    2009-11-01

    Natural toxins such as phytotoxins and mycotoxins have been studied in food and feed for decades, but little attention has yet been paid to their occurrence in the environment. Because of increasing awareness of the presence and potential relevance of micropollutants in the environment, phytotoxins and mycotoxins should be considered and investigated as part of the chemical cocktail in natural samples. Here, we compile chemical analytical methods to determine important phytotoxins (i.e. phenolic acids, quinones, benzoxazinones, terpenoids, glycoalkaloids, glucosinolates, isothiocyanates, phytosterols, flavonoids, coumestans, lignans, and chalcones) and mycotoxins (i.e. resorcyclic acid lactones, trichothecenes, fumonisins, and aflatoxins) in environmentally relevant matrices such as surface water, waste water-treatment plant influent and effluent, soil, sediment, manure, and sewage sludge. The main problems encountered in many of the reviewed methods were the frequent unavailability of suitable internal standards (especially isotope-labelled analogues) and often absent or fragmentary method optimization and validation.

  17. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

    Directory of Open Access Journals (Sweden)

    Shibli Nisar

    2016-01-01

    Full Text Available Short Time Fourier Transform (STFT is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT. Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

  18. Visual selective attention in body dysmorphic disorder, bulimia nervosa and healthy controls.

    Science.gov (United States)

    Kollei, Ines; Horndasch, Stefanie; Erim, Yesim; Martin, Alexandra

    2017-01-01

    Cognitive behavioral models postulate that selective attention plays an important role in the maintenance of body dysmorphic disorder (BDD). It is suggested that individuals with BDD overfocus on perceived defects in their appearance, which may contribute to the excessive preoccupation with their appearance. The present study used eye tracking to examine visual selective attention in individuals with BDD (n=19), as compared to individuals with bulimia nervosa (BN) (n=21) and healthy controls (HCs) (n=21). Participants completed interviews, questionnaires, rating scales and an eye tracking task: Eye movements were recorded while participants viewed photographs of their own face and attractive as well as unattractive other faces. Eye tracking data showed that BDD and BN participants focused less on their self-rated most attractive facial part than HCs. Scanning patterns in own and other faces showed that BDD and BN participants paid as much attention to attractive as to unattractive features in their own face, whereas they focused more on attractive features in attractive other faces. HCs paid more attention to attractive features in their own face and did the same in attractive other faces. Results indicate an attentional bias in BDD and BN participants manifesting itself in a neglect of positive features compared to HCs. Perceptual retraining may be an important aspect to focus on in therapy in order to overcome the neglect of positive facial aspects. Future research should aim to disentangle attentional processes in BDD by examining the time course of attentional processing. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Body-Selective Areas in the Visual Cortex are less active in Children than in Adults

    Directory of Open Access Journals (Sweden)

    Paddy D Ross

    2014-11-01

    Full Text Available Our ability to read other people’s non-verbal signals gets refined throughout childhood and adolescence. How this is paralleled by brain development has been investigated mainly with regards to face perception, showing a protracted functional development of the face-selective visual cortical areas. In view of the importance of whole-body expressions in interpersonal communication it is important to understand the development of brain areas sensitive to these social signals.Here we used functional magnetic resonance imaging (fMRI to compare brain activity in a group of 24 children (age 6-11 and 26 adults while they passively watched short videos of body or object movements. We observed activity in similar regions in both groups; namely the extra-striate body area (EBA, fusiform body area (FBA, posterior superior temporal sulcus (pSTS, amygdala and premotor regions. Adults showed additional activity in the inferior frontal gyrus. Within the main body-selective regions (EBA, FBA and pSTS, the strength and spatial extent of fMRI signal change was larger in adults than in children. Multivariate Bayesian analysis showed that the spatial pattern of neural representation within those regions did not change over age.Our results indicate, for the first time, that body perception, like face perception, is still maturing through the second decade of life.

  20. Visual Search for Motion-Form Conjunctions: Selective Attention to Movement Direction.

    Science.gov (United States)

    Von Mühlenen, Adrian; Müller, Hermann J

    1999-07-01

    In 2 experiments requiring visual search for conjunctions of motion and form, the authors reinvestigated whether motion-based filtering (e.g., P. McLeod, J. Driver, Z. Dienes, & J. Crisp, 1991) is direction selective and whether cuing of the target direction promotes efficient search performance. In both experiments, the authors varied the number of movement directions in the display and the predictability of the target direction. Search was less efficient when items moved in multiple (2, 3, and 4) directions as compared with just 1 direction. Furthermore, precuing of the target direction facilitated the search, even with "wrap-around" displays, relatively more when items moved in multiple directions. The authors proposed 2 principles to explain that pattern of effects: (a) interference on direction computation between items moving in different directions (e.g., N. Qian & R. A. Andersen, 1994) and (b) selective direction tuning of motion detectors involving a receptive-field contraction (cf. J. Moran & R. Desimone, 1985; S. Treue & J. H. R. Maunsell, 1996).

  1. Environmental Resources of Selected Areas of Hawaii: Geological Hazards (DRAFT)

    Energy Technology Data Exchange (ETDEWEB)

    Staub, W.P.

    1994-06-01

    This report has been prepared to make available and archive the background scientific data and related information collected on geologic hazards during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The U.S. Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 (Fed Regis. 5925638) withdrawing its Notice of Intent (Fed Regis. 575433) of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated This report presents a review of current information on geologic hazards in the Hawaiian Islands. Interrelationships among these hazards are discussed. Probabilities of occurrence of given geologic hazards are provided in various regions where sufficient geologic or historical data are available. Most of the information contained herein is compiled from recent U.S. Geological Survey (USGS) publications and open-file reports. This report describes the natural geologic hazards present in the area and does not represent an assessment of environmental impacts. Geologic hazards originate both onshore and offshore. Onshore geologic hazards such as volcanic eruptions, earthquakes, surface rupture, landslides, uplift, and subsidence occur mainly on the southern third of the island of Hawaii (hereinafter referred to as Hawaii). Offshore geologic hazards are more widely distributed throughout the Hawaiian Islands. Examples of offshore geologic hazards are submarine landslides, turbidity currents, and seismic sea waves (tsunamis). First, overviews of volcanic and earthquake activity, and details of offshore geologic hazards is provided for the Hawaiian Islands. Then, a more detailed discussion of onshore geologic hazards is presented with special emphasis on the southern third of Hawaii and the east rift

  2. Is selective mutism associated with deficits in memory span and visual memory?: An exploratory case-control study.

    Science.gov (United States)

    Kristensen, Hanne; Oerbeck, Beate

    2006-01-01

    Our main aim in this study was to explore the association between selective mutism (SM) and aspects of nonverbal cognition such as visual memory span and visual memory. Auditory-verbal memory span was also examined. The etiology of SM is unclear, and it probably represents a heterogeneous condition. SM is associated with language impairment, but nonspecific neurodevelopmental factors, including motor problems, are also reported in SM without language impairment. Furthermore, SM is described in Asperger's syndrome. Studies on nonverbal cognition in SM thus merit further investigation. Neuropsychological tests were administered to a clinical sample of 32 children and adolescents with SM (ages 6-17 years, 14 boys and 18 girls) and 62 nonreferred controls matched for age, gender, and socioeconomic status. We used independent t-tests to compare groups with regard to auditory-verbal memory span, visual memory span, and visual memory (Benton Visual Retention Test), and employed linear regression analysis to study the impact of SM on visual memory, controlling for IQ and measures of language and motor function. The SM group differed from controls on auditory-verbal memory span but not on visual memory span. Controlled for IQ, language, and motor function, the SM group did not differ from controls on visual memory. Motor function was the strongest predictor of visual memory performance. SM does not appear to be associated with deficits in visual memory span or visual memory. The reduced auditory-verbal memory span supports the association between SM and language impairment. More comprehensive neuropsychological studies are needed.

  3. Not in Your Backyard? Selective Tariff Cuts for Environmentally Preferable Products

    OpenAIRE

    Estelle, Gozlan; Ramos, Maria Priscila

    2007-01-01

    Current negotiations at the WTO’s Committee on Trade and Environment have made it conceivable that WTO members agree on selective tariff cuts for certain Environmentally Preferable Products, in an attempt to combine gains from trade and from cleaner production/consumption. This raises questions on the environmental and welfare implications of trade policy when a close substitute (“environmentally worse") exists. Using a simple partial equilibrium model with two substitutable goods ('green' an...

  4. Efficient spiking neural network model of pattern motion selectivity in visual cortex.

    Science.gov (United States)

    Beyeler, Michael; Richert, Micah; Dutt, Nikil D; Krichmar, Jeffrey L

    2014-07-01

    Simulating large-scale models of biological motion perception is challenging, due to the required memory to store the network structure and the computational power needed to quickly solve the neuronal dynamics. A low-cost yet high-performance approach to simulating large-scale neural network models in real-time is to leverage the parallel processing capability of graphics processing units (GPUs). Based on this approach, we present a two-stage model of visual area MT that we believe to be the first large-scale spiking network to demonstrate pattern direction selectivity. In this model, component-direction-selective (CDS) cells in MT linearly combine inputs from V1 cells that have spatiotemporal receptive fields according to the motion energy model of Simoncelli and Heeger. Pattern-direction-selective (PDS) cells in MT are constructed by pooling over MT CDS cells with a wide range of preferred directions. Responses of our model neurons are comparable to electrophysiological results for grating and plaid stimuli as well as speed tuning. The behavioral response of the network in a motion discrimination task is in agreement with psychophysical data. Moreover, our implementation outperforms a previous implementation of the motion energy model by orders of magnitude in terms of computational speed and memory usage. The full network, which comprises 153,216 neurons and approximately 40 million synapses, processes 20 frames per second of a 40 × 40 input video in real-time using a single off-the-shelf GPU. To promote the use of this algorithm among neuroscientists and computer vision researchers, the source code for the simulator, the network, and analysis scripts are publicly available.

  5. (En)Countering Social and Environmental Messages in the Rainforest Cafe [sic], Children's Picturebooks, and Other Visual Culture Sites

    Science.gov (United States)

    Reisberg, Mira; Han, Sandrine

    2009-01-01

    Our study critically examines social and environmental messages in a range of visual sites educating about rainforest environments. We focus primarily on the Rainforest Cafe, an international series of rainforest-themed edutainment restaurant/stores, whose inherent contradictions between consumption and conservation are quite disturbing when…

  6. Different effects of color-based and location-based selection on visual working memory.

    Science.gov (United States)

    Li, Qi; Saiki, Jun

    2015-02-01

    In the present study, we investigated how feature- and location-based selection influences visual working memory (VWM) encoding and maintenance. In Experiment 1, cue type (color, location) and cue timing (precue, retro-cue) were manipulated in a change detection task. The stimuli were color-location conjunction objects, and binding memory was tested. We found a significantly greater effect for color precues than for either color retro-cues or location precues, but no difference between location pre- and retro-cues, consistent with previous studies (e.g., Griffin & Nobre in Journal of Cognitive Neuroscience, 15, 1176-1194, 2003). We also found no difference between location and color retro-cues. Experiment 2 replicated the color precue advantage with more complex color-shape-location conjunction objects. Only one retro-cue effect was different from that in Experiment 1: Color retro-cues were significantly less effective than location retro-cues in Experiment 2, which may relate to a structural property of multidimensional VWM representations. In Experiment 3, a visual search task was used, and the result of a greater location than color precue effect suggests that the color precue advantage in a memory task is related to the modulation of VWM encoding rather than of sensation and perception. Experiment 4, using a task that required only memory for individual features but not for feature bindings, further confirmed that the color precue advantage is specific to binding memory. Together, these findings reveal new aspects of the interaction between attention and VWM and provide potentially important implications for the structural properties of VWM representations.

  7. Environmental resources of selected areas of Hawaii: Ecological resources

    Energy Technology Data Exchange (ETDEWEB)

    Trettin, C.C.; Tolbert, V.R. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Jones, A.T. [Jones (Anthony T.), Vancouver, British Columbia (Canada); Smith, C.R. [Smith (Craig R.), Kailna, HI (United States); Kalmijn, A.J. [Kalmijn (Adrianus J.), Encinitas, CA (United States)

    1995-03-01

    This report has been prepared to make available and archive the background scientific data and related information collected on ecological resources during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The background scientific data and related information presented in this report focus on several areas of Hawaii County. In this report, reference is made to these areas as study areas rather than as areas where proposed or alternative facilities of the HGP would be located. The resource areas addressed herein include terrestrial ecology, aquatic ecology, and marine ecology. The scientific background data and related information that were obtained from review of the (1) scientific literature, (2) government and private sector reports, (3) studies done under DOE interagency agreements with the US Fish and Wildlife Service (FWS) and with the US Army Corps of Engineers (COE), and (4) observations made during site visits are being made available for future research in these areas.

  8. Environmental resources of selected areas of Hawaii: Ecological resources

    International Nuclear Information System (INIS)

    Trettin, C.C.; Tolbert, V.R.; Smith, C.R.; Kalmijn, A.J.

    1995-03-01

    This report has been prepared to make available and archive the background scientific data and related information collected on ecological resources during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The background scientific data and related information presented in this report focus on several areas of Hawaii County. In this report, reference is made to these areas as study areas rather than as areas where proposed or alternative facilities of the HGP would be located. The resource areas addressed herein include terrestrial ecology, aquatic ecology, and marine ecology. The scientific background data and related information that were obtained from review of the (1) scientific literature, (2) government and private sector reports, (3) studies done under DOE interagency agreements with the US Fish and Wildlife Service (FWS) and with the US Army Corps of Engineers (COE), and (4) observations made during site visits are being made available for future research in these areas

  9. Reorganization of neural systems mediating peripheral visual selective attention in the deaf: An optical imaging study.

    Science.gov (United States)

    Seymour, Jenessa L; Low, Kathy A; Maclin, Edward L; Chiarelli, Antonio M; Mathewson, Kyle E; Fabiani, Monica; Gratton, Gabriele; Dye, Matthew W G

    2017-01-01

    Theories of brain plasticity propose that, in the absence of input from the preferred sensory modality, some specialized brain areas may be recruited when processing information from other modalities, which may result in improved performance. The Useful Field of View task has previously been used to demonstrate that early deafness positively impacts peripheral visual attention. The current study sought to determine the neural changes associated with those deafness-related enhancements in visual performance. Based on previous findings, we hypothesized that recruitment of posterior portions of Brodmann area 22, a brain region most commonly associated with auditory processing, would be correlated with peripheral selective attention as measured using the Useful Field of View task. We report data from severe to profoundly deaf adults and normal-hearing controls who performed the Useful Field of View task while cortical activity was recorded using the event-related optical signal. Behavioral performance, obtained in a separate session, showed that deaf subjects had lower thresholds (i.e., better performance) on the Useful Field of View task. The event-related optical data indicated greater activity for the deaf adults than for the normal-hearing controls during the task in the posterior portion of Brodmann area 22 in the right hemisphere. Furthermore, the behavioral thresholds correlated significantly with this neural activity. This work provides further support for the hypothesis that cross-modal plasticity in deaf individuals appears in higher-order auditory cortices, whereas no similar evidence was obtained for primary auditory areas. It is also the only neuroimaging study to date that has linked deaf-related changes in the right temporal lobe to visual task performance outside of the imaging environment. The event-related optical signal is a valuable technique for studying cross-modal plasticity in deaf humans. The non-invasive and relatively quiet characteristics of

  10. Functionalized membranes for environmental remediation and selective separation

    Science.gov (United States)

    Xiao, Li

    ) between UF and RO presents selectivity controlled by both steric and electrostatic repulsions, which are widely used to reject charged species, particularly multivalent ions. In this work, selective permeation of CaCl2 and high sucrose retention are obtained through the modification of nanofiltration membranes with lower charge compared to commercial nanofiltration membrane. The membrane module also shows high stability with constant water permeability in a long-term (two months) test. Extended Nernst-Planck equation were further used to evaluate the experimental results and it fits well. KEY WORDS: Functionalized Membrane, Dechlorination, Responsive, Tunable, Full-scale.

  11. Cross-modal selective attention: on the difficulty of ignoring sounds at the locus of visual attention.

    Science.gov (United States)

    Spence, C; Ranson, J; Driver, J

    2000-02-01

    In three experiments, we investigated whether the ease with which distracting sounds can be ignored depends on their distance from fixation and from attended visual events. In the first experiment, participants shadowed an auditory stream of words presented behind their heads, while simultaneously fixating visual lip-read information consistent with the relevant auditory stream, or meaningless "chewing" lip movements. An irrelevant auditory stream of words, which participants had to ignore, was presented either from the same side as the fixated visual stream or from the opposite side. Selective shadowing was less accurate in the former condition, implying that distracting sounds are harder to ignore when fixated. Furthermore, the impairment when fixating toward distractor sounds was greater when speaking lips were fixated than when chewing lips were fixated, suggesting that people find it particularly difficult to ignore sounds at locations that are actively attended for visual lipreading rather than merely passively fixated. Experiments 2 and 3 tested whether these results are specific to cross-modal links in speech perception by replacing the visual lip movements with a rapidly changing stream of meaningless visual shapes. The auditory task was again shadowing, but the active visual task was now monitoring for a specific visual shape at one location. A decrement in shadowing was again observed when participants passively fixated toward the irrelevant auditory stream. This decrement was larger when participants performed a difficult active visual task there versus fixating, but not for a less demanding visual task versus fixation. The implications for cross-modal links in spatial attention are discussed.

  12. Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex.

    Science.gov (United States)

    Ptak, Radek; Lazeyras, François; Di Pietro, Marie; Schnider, Armin; Simon, Stéphane R

    2014-07-01

    Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studied a patient with object agnosia following isolated damage to the left occipito-temporal cortex overlapping with the LOC. The patient showed intact processing of object structure, yet often made identification errors that were mainly based on the global visual similarity between objects. Using functional Magnetic Resonance Imaging (fMRI) we found that the damaged as well as the contralateral, structurally intact right LOC failed to show any object-selective fMRI activity, though the latter retained selectivity for faces. Thus, unilateral damage to the left LOC led to a bilateral breakdown of neural responses to a specific stimulus class (objects and artefacts) while preserving the response to a different stimulus class (faces). These findings indicate that representations of structure necessary for the identification of objects crucially rely on bilateral, distributed coding of shape features. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Identification and evaluation of influential criteria for the selection of an environmental shipping carrier using DEMATEL

    DEFF Research Database (Denmark)

    Jia, Peng; Govindan, Kannan; Kannan, Devika

    2015-01-01

    The current environmental pollution is a major factor in economic development and vehicle pollution is ranked next to industrial emissions in total emissions worldwide. This study focuses on the selection of a suitable shipping carrier from an economic and environmental perspective. In practice......, there are many criteria's available to select a suitable shipping container. But, shipping container companies are struggling to identify the most influential criteria to select a shipping container as it requires in-depth analysis. So, the objective of this paper is to analyse the criteria and identify the most...... influential criteria from an environmental practices perspective. In this study, seventeen factors are identified from literature aimed at locating the most influential criteria to select a suitable shipping carrier using the decision making trial and evaluation laboratory (DEMATEL). This procedure helps...

  14. URABN LEGIBILITY AND SHAPING THE IMAGE OF DOHA: Visual Analysis of the Environmental Graphics of the 15th. Asian Games

    Directory of Open Access Journals (Sweden)

    Abeer A. Hasanin

    2007-11-01

    Full Text Available This paper explores urban legibility and the associated elements that contribute to the image of the city. It investigates the graphics of the 15th. Asian Games that took place in Doha, December 2006, while placing emphasis on environmental graphics as a vehicle for shaping our indoor and outdoor visual environment. Utilizing the concept of environmental quality and its underlying notion of legibility, the paper analytically describes the environmental graphics of the games event and preliminarily measures Doha residents’ reactions to graphics-based urban settings within the city. The results of performing these procedures reveal that environmental graphics can contribute in shaping the memory of city images and can help establish associations between people past, present and future experience of urban scenes. such results call for including environmental graphics in the work of architects and urban designers toward shaping better memorable images of cities.

  15. Anxiety-related biases in visual orienting and spatial motor response selection independently assessed by a probe-classification task

    NARCIS (Netherlands)

    Schrooten, M.G.S.; Smulders, F.T.Y.; Mogg, K.; Bradley, B.P.

    2012-01-01

    This dot-probe study assessed anxiety-related biases in visual attentional orienting and spatial motor response selection (motor attention) in high- and low-trait-anxious adults, and whether anxiety-related biases depend on response speed. Emotional-neutral word pairs appeared for 14 or 500 ms, with

  16. An event-related brain potential study of visual selective attention to conjunctions of color and shape

    NARCIS (Netherlands)

    Smid, HGOM; Jakob, A; Heinze, HJ

    What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other

  17. Selective Visual Attention during Mirror Exposure in Anorexia and Bulimia Nervosa.

    Directory of Open Access Journals (Sweden)

    Brunna Tuschen-Caffier

    Full Text Available Cognitive theories suggest that body dissatisfaction results from the activation of maladaptive appearance schemata, which guide mental processes such as selective attention to shape and weight-related information. In line with this, the present study hypothesized that patients with anorexia nervosa (AN and bulimia nervosa (BN are characterized by increased visual attention for the most dissatisfying/ugly body part compared to their most satisfying/beautiful body part, while a more balanced viewing pattern was expected for controls without eating disorders (CG.Eye movements were recorded in a group of patients with AN (n = 16, BN (n = 16 and a CG (n = 16 in an ecologically valid setting, i.e., during a 3-min mirror exposure.Evidence was found that patients with AN and BN display longer and more frequent gazes towards the most dissatisfying relative to the most satisfying and towards their most ugly compared to their most beautiful body parts, whereas the CG showed a more balanced gaze pattern.The results converge with theoretical models that emphasize the role of information processing in the maintenance of body dissatisfaction. Given the etiological importance of body dissatisfaction in the development of eating disorders, future studies should focus on the modification of the reported patterns.

  18. Selective visual attention for ugly and beautiful body parts in eating disorders.

    Science.gov (United States)

    Jansen, Anita; Nederkoorn, Chantal; Mulkens, Sandra

    2005-02-01

    Body image disturbance is characteristic of eating disorders, and current treatments use body exposure to reduce bad body feelings. There is however little known about the cognitive effects of body exposure. In the present study, eye movement registration (electroculography) as a direct index of selective visual attention was used while eating symptomatic and normal control participants were exposed to digitalized pictures of their own body and control bodies. The data showed a decreased focus on their own 'beautiful' body parts in the high symptomatic participants, whereas inspection of their own 'ugly' body parts was given priority. In the normal control group a self-serving cognitive bias was found: they focused more on their own 'beautiful' body parts and less on their own 'ugly' body parts. When viewing other bodies the pattern was reversed: high symptom participants allocated their attention to the beautiful parts of other bodies, whereas normal controls concentrated on the ugly parts of the other bodies. From the present findings the hypothesis follows that a change in the processing of information might be needed for body exposure to be successful.

  19. Selective Visual Attention during Mirror Exposure in Anorexia and Bulimia Nervosa

    Science.gov (United States)

    Tuschen-Caffier, Brunna; Bender, Caroline; Caffier, Detlef; Klenner, Katharina; Braks, Karsten; Svaldi, Jennifer

    2015-01-01

    Objective Cognitive theories suggest that body dissatisfaction results from the activation of maladaptive appearance schemata, which guide mental processes such as selective attention to shape and weight-related information. In line with this, the present study hypothesized that patients with anorexia nervosa (AN) and bulimia nervosa (BN) are characterized by increased visual attention for the most dissatisfying/ugly body part compared to their most satisfying/beautiful body part, while a more balanced viewing pattern was expected for controls without eating disorders (CG). Method Eye movements were recorded in a group of patients with AN (n = 16), BN (n = 16) and a CG (n = 16) in an ecologically valid setting, i.e., during a 3-min mirror exposure. Results Evidence was found that patients with AN and BN display longer and more frequent gazes towards the most dissatisfying relative to the most satisfying and towards their most ugly compared to their most beautiful body parts, whereas the CG showed a more balanced gaze pattern. Discussion The results converge with theoretical models that emphasize the role of information processing in the maintenance of body dissatisfaction. Given the etiological importance of body dissatisfaction in the development of eating disorders, future studies should focus on the modification of the reported patterns. PMID:26714279

  20. Rapid Improvement in Visual Selective Attention Related to Action Video Gaming Experience

    Directory of Open Access Journals (Sweden)

    Nan Qiu

    2018-02-01

    Full Text Available A central issue in cognitive science is understanding how learning induces cognitive and neural plasticity, which helps illuminate the biological basis of learning. Research in the past few decades showed that action video gaming (AVG offered new, important perspectives on learning-related cognitive and neural plasticity. However, it is still unclear whether cognitive and neural plasticity is observable after a brief AVG session. Using behavioral and electrophysiological measures, this study examined the plasticity of visual selective attention (VSA associated with a 1 h AVG session. Both AVG experts and non-experts participated in this study. Their VSA was assessed prior to and after the AVG session. Within-group comparisons on the participants' performance before and after the AVG session showed improvements in response time in both groups and modulations of electrophysiological measures in the non-experts. Furthermore, between-group comparisons showed that the experts had superior VSA, relative to the non-experts, prior to the AVG session. These findings suggested an association between the plasticity of VSA and AVG. Most importantly, this study showed that the plasticity of VSA was observable after even a 1 h AVG session.

  1. Rapid Improvement in Visual Selective Attention Related to Action Video Gaming Experience.

    Science.gov (United States)

    Qiu, Nan; Ma, Weiyi; Fan, Xin; Zhang, Youjin; Li, Yi; Yan, Yuening; Zhou, Zhongliang; Li, Fali; Gong, Diankun; Yao, Dezhong

    2018-01-01

    A central issue in cognitive science is understanding how learning induces cognitive and neural plasticity, which helps illuminate the biological basis of learning. Research in the past few decades showed that action video gaming (AVG) offered new, important perspectives on learning-related cognitive and neural plasticity. However, it is still unclear whether cognitive and neural plasticity is observable after a brief AVG session. Using behavioral and electrophysiological measures, this study examined the plasticity of visual selective attention (VSA) associated with a 1 h AVG session. Both AVG experts and non-experts participated in this study. Their VSA was assessed prior to and after the AVG session. Within-group comparisons on the participants' performance before and after the AVG session showed improvements in response time in both groups and modulations of electrophysiological measures in the non-experts. Furthermore, between-group comparisons showed that the experts had superior VSA, relative to the non-experts, prior to the AVG session. These findings suggested an association between the plasticity of VSA and AVG. Most importantly, this study showed that the plasticity of VSA was observable after even a 1 h AVG session.

  2. Object-based attention benefits reveal selective abnormalities of visual integration in autism.

    Science.gov (United States)

    Falter, Christine M; Grant, Kate C Plaisted; Davis, Greg

    2010-06-01

    A pervasive integration deficit could provide a powerful and elegant account of cognitive processing in autism spectrum disorders (ASD). However, in the case of visual Gestalt grouping, typically assessed by tasks that require participants explicitly to introspect on their own grouping perception, clear evidence for such a deficit remains elusive. To resolve this issue, we adopt an index of Gestalt grouping from the object-based attention literature that does not require participants to assess their own grouping perception. Children with ASD and mental- and chronological-age matched typically developing children (TD) performed speeded orientation discriminations of two diagonal lines. The lines were superimposed on circles that were either grouped together or segmented on the basis of color, proximity or these two dimensions in competition. The magnitude of performance benefits evident for grouped circles, relative to ungrouped circles, provided an index of grouping under various conditions. Children with ASD showed comparable grouping by proximity to the TD group, but reduced grouping by similarity. ASD seems characterized by a selective bias away from grouping by similarity combined with typical levels of grouping by proximity, rather than by a pervasive integration deficit.

  3. Saccade frequency response to visual cues during gait in Parkinson's disease: the selective role of attention.

    Science.gov (United States)

    Stuart, Samuel; Lord, Sue; Galna, Brook; Rochester, Lynn

    2018-04-01

    Gait impairment is a core feature of Parkinson's disease (PD) with implications for falls risk. Visual cues improve gait in PD, but the underlying mechanisms are unclear. Evidence suggests that attention and vision play an important role; however, the relative contribution from each is unclear. Measurement of visual exploration (specifically saccade frequency) during gait allows for real-time measurement of attention and vision. Understanding how visual cues influence visual exploration may allow inferences of the underlying mechanisms to response which could help to develop effective therapeutics. This study aimed to examine saccade frequency during gait in response to a visual cue in PD and older adults and investigate the roles of attention and vision in visual cue response in PD. A mobile eye-tracker measured saccade frequency during gait in 55 people with PD and 32 age-matched controls. Participants walked in a straight line with and without a visual cue (50 cm transverse lines) presented under single task and dual-task (concurrent digit span recall). Saccade frequency was reduced when walking in PD compared to controls; however, visual cues ameliorated saccadic deficit. Visual cues significantly increased saccade frequency in both PD and controls under both single task and dual-task. Attention rather than visual function was central to saccade frequency and gait response to visual cues in PD. In conclusion, this study highlights the impact of visual cues on visual exploration when walking and the important role of attention in PD. Understanding these complex features will help inform intervention development. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Selective transfer of visual working memory training on Chinese character learning.

    Science.gov (United States)

    Opitz, Bertram; Schneiders, Julia A; Krick, Christoph M; Mecklinger, Axel

    2014-01-01

    Previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages. However, little is known about the impact of working memory processes on second language learning in a non-alphabetic language such as Mandarin Chinese. Due to the greater complexity of the Chinese writing system we expect that visual working memory rather than phonological working memory exerts a unique influence on learning Chinese characters. This issue was explored in the present experiment by comparing visual working memory training with an active (auditory working memory training) control condition and a passive, no training control condition. Training induced modulations in language-related brain networks were additionally examined using functional magnetic resonance imaging in a pretest-training-posttest design. As revealed by pre- to posttest comparisons and analyses of individual differences in working memory training gains, visual working memory training led to positive transfer effects on visual Chinese vocabulary learning compared to both control conditions. In addition, we found sustained activation after visual working memory training in the (predominantly visual) left infero-temporal cortex that was associated with behavioral transfer. In the control conditions, activation either increased (active control condition) or decreased (passive control condition) without reliable behavioral transfer effects. This suggests that visual working memory training leads to more efficient processing and more refined responses in brain regions involved in visual processing. Furthermore, visual working memory training boosted additional activation in the precuneus, presumably reflecting mental image generation of the learned characters. We, therefore, suggest that the conjoint activity of the mid-fusiform gyrus and the precuneus after visual working memory training reflects an interaction of working memory and

  5. Relative Effects of Visualized and Verbal Presentation Methods in Communicating Environmental Information among Stakeholders: Okavango Delta, Botswana

    Science.gov (United States)

    Thakadu, Olekae T.; Irani, Tracy; Telg, Ricky

    2011-01-01

    The present study examined the relative effectiveness of 2 public instructional communication methods in improving selected predictors of knowledge-sharing behaviors among communities in the Okavango Delta, Botswana. A total of 120 subjects took part in a quasiexperimental study, with 2 experimental treatments: (a) visualized PowerPoint…

  6. Temporal limits of selection and memory encoding: A comparison of whole versus partial report in rapid serial visual presentation.

    Science.gov (United States)

    Nieuwenstein, Mark R; Potter, Mary C

    2006-06-01

    People often fail to recall the second of two visual targets presented within 500 ms in rapid serial visual presentation (RSVP). This effect is called the attentional blink. One explanation of the attentional blink is that processes involved in encoding the first target into memory are slow and capacity limited. Here, however, we show that the attentional blink should be ascribed to attentional selection, not consolidation of the first target. Rapid sequences of six letters were presented, and observers had to report either all the letters (whole-report condition) or a subset of the letters (partial-report condition). Selection in partial report was based on color (e.g., report the two red letters) or identity (i.e., report all letters from a particular letter onward). In both cases, recall of letters presented shortly after the first selected letter was impaired, whereas recall of the corresponding letters was relatively accurate with whole report.

  7. A paired case-control comparison of ziprasidone on visual sustained attention and visual selective attention in patients with paranoid schizophrenia.

    Science.gov (United States)

    Chen, X; Zhang, Z H; Song, Y; Yuan, W; Liu, Z X; Tang, M Q

    2015-08-01

    Cognitive impairment is one of the main targets of the treatment to schizophrenia.The atypical antipsychotic was proved to improve the cognition function of the patients. There were a few of clinical trials to detect the effect of medicine treatment on attention function. But the respective changes of sustained and selective attention in the patients with treatment of ziprasidone were rarely investigated. This present study was to explore the effect of ziprasidone on visual sustained and selective attention in schizophrenia. There were 81 patients who were treated with ziprasidone and matched with 81 healthy controls in this open-label trial. The functions were evaluated by Continuous Performance Test (CPT) and Color Word Test (CWT) at baseline and eight weeks later. Between two groups the functions were compared at the two time points, and in patients group those were compared prior to and post treatment. As compared with healthy controls, the functions of the patients were worse. But after 8 weeks treatment of ziprasidone the functions improved in some degree, which were indicated by the change of CPT and CWT indexes. Furthermore, those of patients post treatment were better than prior to treatment. Patients with paranoid schizophrenia have visual sustained and selective attention deficits. The deficits can be improved partly with ziprasidone treatment.

  8. Early auditory evoked potential is modulated by selective attention and related to individual differences in visual working memory capacity.

    Science.gov (United States)

    Giuliano, Ryan J; Karns, Christina M; Neville, Helen J; Hillyard, Steven A

    2014-12-01

    A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual's capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70-90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals.

  9. Early Auditory Evoked Potential Is Modulated by Selective Attention and Related to Individual Differences in Visual Working Memory Capacity

    Science.gov (United States)

    Giuliano, Ryan J.; Karns, Christina M.; Neville, Helen J.; Hillyard, Steven A.

    2015-01-01

    A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual’s capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70–90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals. PMID:25000526

  10. Investigating category- and shape-selective neural processing in ventral and dorsal visual stream under interocular suppression.

    Science.gov (United States)

    Ludwig, Karin; Kathmann, Norbert; Sterzer, Philipp; Hesselmann, Guido

    2015-01-01

    Recent behavioral and neuroimaging studies using continuous flash suppression (CFS) have suggested that action-related processing in the dorsal visual stream might be independent of perceptual awareness, in line with the "vision-for-perception" versus "vision-for-action" distinction of the influential dual-stream theory. It remains controversial if evidence suggesting exclusive dorsal stream processing of tool stimuli under CFS can be explained by their elongated shape alone or by action-relevant category representations in dorsal visual cortex. To approach this question, we investigated category- and shape-selective functional magnetic resonance imaging-blood-oxygen level-dependent responses in both visual streams using images of faces and tools. Multivariate pattern analysis showed enhanced decoding of elongated relative to non-elongated tools, both in the ventral and dorsal visual stream. The second aim of our study was to investigate whether the depth of interocular suppression might differentially affect processing in dorsal and ventral areas. However, parametric modulation of suppression depth by varying the CFS mask contrast did not yield any evidence for differential modulation of category-selective activity. Together, our data provide evidence for shape-selective processing under CFS in both dorsal and ventral stream areas and, therefore, do not support the notion that dorsal "vision-for-action" processing is exclusively preserved under interocular suppression. © 2014 Wiley Periodicals, Inc.

  11. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

    Science.gov (United States)

    Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-01-01

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)—a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with λmax = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  12. Lrit1, a Retinal Transmembrane Protein, Regulates Selective Synapse Formation in Cone Photoreceptor Cells and Visual Acuity

    Directory of Open Access Journals (Sweden)

    Akiko Ueno

    2018-03-01

    Full Text Available Summary: In the vertebrate retina, cone photoreceptors play crucial roles in photopic vision by transmitting light-evoked signals to ON- and/or OFF-bipolar cells. However, the mechanisms underlying selective synapse formation in the cone photoreceptor pathway remain poorly understood. Here, we found that Lrit1, a leucine-rich transmembrane protein, localizes to the photoreceptor synaptic terminal and regulates the synaptic connection between cone photoreceptors and cone ON-bipolar cells. Lrit1-deficient retinas exhibit an aberrant morphology of cone photoreceptor pedicles, as well as an impairment of signal transmission from cone photoreceptors to cone ON-bipolar cells. Furthermore, we demonstrated that Lrit1 interacts with Frmpd2, a photoreceptor scaffold protein, and with mGluR6, an ON-bipolar cell-specific glutamate receptor. Additionally, Lrit1-null mice showed visual acuity impairments in their optokinetic responses. These results suggest that the Frmpd2-Lrit1-mGluR6 axis regulates selective synapse formation in cone photoreceptors and is essential for normal visual function. : Ueno et al. finds that Lrit1 plays an important role in regulating the synaptic connection between cone photoreceptors and cone ON-bipolar cells. The Frmpd2-Lrit1-mGluR6 axis is crucial for selective synapse formation in cone photoreceptors and for development of normal visual function. Keywords: retina, circuit, synapse formation, cone photoreceptor cell, ON-bipolar cell, visual acuity

  13. Different processing phases for features, figures, and selective attention in the primary visual cortex

    NARCIS (Netherlands)

    Roelfsema, P.R.; Tolboom, M.; Khayat, P.S.

    2007-01-01

    Our visual system imposes structure onto images that usually contain a diversity of surfaces, contours, and colors. Psychological theories propose that there are multiple steps in this process that occur in hierarchically organized regions of the cortex: early visual areas register basic features,

  14. A Motor-Skills Programme to Enhance Visual Motor Integration of Selected Pre-School Learners

    Science.gov (United States)

    Africa, Eileen K.; van Deventer, Karel J.

    2017-01-01

    Pre-schoolers are in a window period for motor skill development. Visual-motor integration (VMI) is the foundation for academic and sport skills. Therefore, it must develop before formal schooling. This study attempted to improve VMI skills. VMI skills were measured with the "Beery-Buktenica developmental test of visual-motor integration 6th…

  15. Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory

    Directory of Open Access Journals (Sweden)

    Sachiko eTakahama

    2014-06-01

    Full Text Available Information on an object’s features bound to its location is very important for maintaining object representations in visual working memory. Interactions with dynamic multi-dimensional objects in an external environment require complex cognitive control, including the selective maintenance of feature-location binding. Here, we used event-related functional magnetic resonance imaging to investigate brain activity and functional connectivity related to the maintenance of complex feature-location binding. Participants were required to detect task-relevant changes in feature-location binding between objects defined by color, orientation, and location. We compared a complex binding task requiring complex feature-location binding (color-orientation-location with a simple binding task in which simple feature-location binding, such as color-location, was task-relevant and the other feature was task-irrelevant. Univariate analyses showed that the dorsolateral prefrontal cortex (DLPFC, hippocampus, and frontoparietal network were activated during the maintenance of complex feature-location binding. Functional connectivity analyses indicated cooperation between the inferior precentral sulcus (infPreCS, DLPFC, and hippocampus during the maintenance of complex feature-location binding. In contrast, the connectivity for the spatial updating of simple feature-location binding determined by reanalyzing the data from Takahama et al. (2010 demonstrated that the superior parietal lobule (SPL cooperated with the DLPFC and hippocampus. These results suggest that the connectivity for complex feature-location binding does not simply reflect general memory load and that the DLPFC and hippocampus flexibly modulate the dorsal frontoparietal network, depending on the task requirements, with the infPreCS involved in the maintenance of complex feature-location binding and the SPL involved in the spatial updating of simple feature-location binding.

  16. A Fuzzy MCDM Approach for Green Supplier Selection from the Economic and Environmental Aspects

    Directory of Open Access Journals (Sweden)

    Hsiu Mei Wang Chen

    2016-01-01

    Full Text Available Due to the challenge of rising public awareness of environmental issues and governmental regulations, green supply chain management (SCM has become an important issue for companies to gain environmental sustainability. Supplier selection is one of the key operational tasks necessary to construct a green SCM. To select the most suitable suppliers, many economic and environmental criteria must be considered in the decision process. Although numerous studies have used economic criteria such as cost, quality, and lead time in the supplier selection process, only some studies have taken into account the environmental issues. This study proposes a comprehensive fuzzy multicriteria decision making (MCDM approach for green supplier selection and evaluation, using both economic and environmental criteria. In the proposed approach, a fuzzy analytic hierarchy process (AHP is employed to determine the important weights of criteria under vague environment. In addition, a fuzzy technique for order performance by similarity to ideal solution (TOPSIS is used to evaluate and rank the potential suppliers. Finally, a case study in Luminance Enhancement Film (LEF industry is presented to illustrate the applicability and efficiency of the proposed method.

  17. Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

    Science.gov (United States)

    Koefoed, Vilhelm F; Assmuss, Jörg; Høvding, Gunnar

    2018-03-25

    To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. The object detection distance was significantly correlated to the level of environmental light (p maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  18. A simple and rapid visual method for the determination of ammonia nitrogen in environmental waters using thymol

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, M.; Fujinaga, K.; Seike, Y.; Honda, S. [Dept. of Material Science, Interdisciplinary Faculty of Science and Engineering, Shimane University, Matsue (Japan)

    1999-11-01

    Simple visual and spectrophotometric methods for the determination of ammonia nitrogen in water are proposed, based on the color development of indothymol blue formed between ammonia and thymol. The color development was accelerated by nitroprusside to complete in 3 min. This color development is remarkably rapid compared with that of the other conventional methods with indothymol blue and indophenol blue. The concentration range of ammonia nitrogen spectrophotometrically determined was 0.04-1.2 mg/L NH{sub 4}-N. The absorbance per 1 {mu}g NH{sub 4}-N was 0.0215 (molar absorptivity = 1.51 x 10{sup 4}) at 690 nm. The visual method not using any instrument as an in situ method in field works was developed based on the optimum conditions for the established spectrophotometric method. This visual method was successfully applied to the determination of ammonia nitrogen in environmental waters. (orig.)

  19. Survey on basic knowledge about exposure and potential environmental and health risks for selected nanomaterials

    DEFF Research Database (Denmark)

    Mikkelsen, Sonja Hagen; Hansen, Erik; Christensen, Trine Boe

    Based on a literature review this report provides a general description as well as an environmental and health profile of 7 nanomaterials. The examined nanomaterials are selected because of expected high use or specific environmental and health properties. Fullerenes, iron, silver, nanoclay...... and titanium-, cerium-, and silicondioxides were studied in the project. Based on current uses, it is concluded that current applications of nano-iron and nanoclay can not cause unexpected “nano-associated” health or environmental problems. Although no specific risk associated with current uses of any of the 7...... other nanomaterials were identified, there are areas where there may be reason for attention and thus need for more knowledge....

  20. Braille alexia during visual hallucination in a blind man with selective calcarine atrophy.

    Science.gov (United States)

    Maeda, Kengo; Yasuda, Hitoshi; Haneda, Masakazu; Kashiwagi, Atsunori

    2003-04-01

    The case of a 56-year-old man who has been blind for 25 years due to retinal degeneration is herein described. The patient complained of elementary visual hallucination, during which it was difficult for him to read Braille. Brain magnetic resonance imaging showed marked atrophy of the bilateral striate cortex. Visual hallucination as a release phenomenon of the primary visual cortex has never been reported to cause alexia for Braille. The present case supports the results of recent functional imaging studies of the recruitment of striate and prestriate cortex for Braille reading.

  1. Choosing Your Poison: Optimizing Simulator Visual System Selection as a Function of Operational Tasks

    Science.gov (United States)

    Sweet, Barbara T.; Kaiser, Mary K.

    2013-01-01

    Although current technology simulator visual systems can achieve extremely realistic levels they do not completely replicate the experience of a pilot sitting in the cockpit, looking at the outside world. Some differences in experience are due to visual artifacts, or perceptual features that would not be present in a naturally viewed scene. Others are due to features that are missing from the simulated scene. In this paper, these differences will be defined and discussed. The significance of these differences will be examined as a function of several particular operational tasks. A framework to facilitate the choice of visual system characteristics based on operational task requirements will be proposed.

  2. Metabolomic analysis of the selection response of Drosophila melanogaster to environmental stress

    DEFF Research Database (Denmark)

    Malmendal, Anders; Sørensen, Jesper Givskov; Overgaard, Johannes

    2013-01-01

    -regulated in response to selection for some of the stresses in this study. Overall, the results illustrate that selection markedly alters the metabolite profile and that the coupling between different levels of biological organization indeed is present though not very strong for stress selection at this level......We investigated the global metabolite response to artificial selection for tolerance to stressful conditions such as cold, heat, starvation, and desiccation, and for longevity in Drosophila melanogaster. Our findings were compared to data from other levels of biological organization, including gene...... expression, physiological traits, and organismal stress tolerance phenotype. Overall, we found that selection for environmental stress tolerance changes the metabolomic (1)H NMR fingerprint largely in a similar manner independent of the trait selected for, indicating that experimental evolution led...

  3. Short-term memory for auditory and visual durations: evidence for selective interference effects.

    Science.gov (United States)

    Rattat, Anne-Claire; Picard, Delphine

    2012-01-01

    The present study sought to determine the format in which visual, auditory and auditory-visual durations ranging from 400 to 600 ms are encoded and maintained in short-term memory, using suppression conditions. Participants compared two stimulus durations separated by an interval of 8 s. During this time, they performed either an articulatory suppression task, a visuospatial tracking task or no specific task at all (control condition). The results showed that the articulatory suppression task decreased recognition performance for auditory durations but not for visual or bimodal ones, whereas the visuospatial task decreased recognition performance for visual durations but not for auditory or bimodal ones. These findings support the modality-specific account of short-term memory for durations.

  4. Visual compatibility of defibrotide with selected drugs during simulated Y-site administration.

    Science.gov (United States)

    Correard, Florian; Savry, Amandine; Gauthier-Villano, Laurence; Pisano, Pascale; Pourroy, Bertrand

    2014-08-01

    The visual compatibility of a solution of defibrotide (the only drug recommended for treatment and prophylaxis of hepatic venoocclusive disease) with solutions of various drugs commonly administered in bone marrow transplant procedures was studied. Solutions of 43 drug products in concentrations typically used in clinical practice were evaluated in 1:1 mixtures with defibrotide solution in glass tubes kept at room temperature. The evaluated products included antiinfectious, corticoid, sedative, analgesic, and cardiovascular agents widely used for hematopoietic stem cell transplantation and other marrow transplant procedures; in most cases, test solutions were prepared via dilution in or reconstitution with sterile water, 0.9% sodium chloride injection, or 5% dextrose injection. The mixtures were visually observed immediately after manual mixing and at specified time points (60, 150, and 240 minutes). Visual compatibility was defined as the absence of color change, haze, fibers, particles, gas generation, and precipitate formation. The effect of mixing order on visual compatibility was ascertained. Of the 43 tested drug solutions, 36 were found to be visually compatible with the defibrotide solution over the entire four-hour study period. Solutions of 7 drugs (amikacin, furosemide, midazolam, mycophenolate mofetil, nicardipine, tobramycin, and vancomycin) were visually incompatible with defibrotide solution. In some cases, evidence of incompatibility was observed intermittently or was dependent on mixing order. Defibrotide solution was found to be visually compatible with solutions of 36 i.v. products that are likely to be coadministered with the drug in a bone marrow transplant unit. Seven drug solutions were visually incompatible with defibrotide solution. Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  5. Using remote sensing in support of environmental management: A framework for selecting products, algorithms and methods

    CSIR Research Space (South Africa)

    De Klerk, HM

    2016-11-01

    Full Text Available Traditionally, to map environmental features using remote sensing, practitioners will use training data to develop models on various satellite data sets using a number of classification approaches and use test data to select a single ‘best performer...

  6. Supramolecular Chemistry of Selective Anion Recognition for Anions of Environmental Relevance

    International Nuclear Information System (INIS)

    Bowman-James, K.; Wilson, G.; Moyer, B. A.

    2004-01-01

    This project involves the design and synthesis of receptors for oxoanions of environmental importance, including emphasis on high level and low activity waste. Target anions have included primarily oxoanions and a study of the basic concepts behind selective binding of target anions. A primary target has been sulfate because of its deleterious influence on the vitrification of tank wastes

  7. A risk index for multicriterial selection of a logging system with low environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Horodnic, Sergiu Andrei, E-mail: horodnic@usv.ro

    2015-02-15

    Setting up the working stages in forest operations is conditioned by environmental protection and forest health requirements. This paper exposes a method for improving the decision-making process by choosing the most environmentally effective logging systems according to terrain configuration and stand characteristics. Such a methodology for selecting machines or logging systems accounting for environment, safety as well as economics, becomes mandatory in the context of sustainable management of forest with multiple functions. Based on analytic hierarchy process analysis the following classification of the environmental performance for four considered alternatives was obtained: skyline system (42.43%), forwarder system (20.22%), skidder system (19.92%) and horse logging system (17.43%). Further, an environmental risk matrix for the most important 28 risk factors specific to any work equipment used in forest operations was produced. In the end, a multicriterial analysis generated a risk index RI ranging between 1.0 and 3.5, which could help choosing the optimal combination of logging system and logging equipment with low environmental impact. In order to demonstrate the usefulness of the proposed approach, a simple application in specific conditions of a harvesting site is presented. - Highlights: • We propose a decision-making algorithm to select eco-friendly logging systems. • Analytic hierarchy process was applied for ranking 4 types of logging systems. • An environmental risk matrix with 28 risk factors in forest operations was made up.

  8. A risk index for multicriterial selection of a logging system with low environmental impact

    International Nuclear Information System (INIS)

    Horodnic, Sergiu Andrei

    2015-01-01

    Setting up the working stages in forest operations is conditioned by environmental protection and forest health requirements. This paper exposes a method for improving the decision-making process by choosing the most environmentally effective logging systems according to terrain configuration and stand characteristics. Such a methodology for selecting machines or logging systems accounting for environment, safety as well as economics, becomes mandatory in the context of sustainable management of forest with multiple functions. Based on analytic hierarchy process analysis the following classification of the environmental performance for four considered alternatives was obtained: skyline system (42.43%), forwarder system (20.22%), skidder system (19.92%) and horse logging system (17.43%). Further, an environmental risk matrix for the most important 28 risk factors specific to any work equipment used in forest operations was produced. In the end, a multicriterial analysis generated a risk index RI ranging between 1.0 and 3.5, which could help choosing the optimal combination of logging system and logging equipment with low environmental impact. In order to demonstrate the usefulness of the proposed approach, a simple application in specific conditions of a harvesting site is presented. - Highlights: • We propose a decision-making algorithm to select eco-friendly logging systems. • Analytic hierarchy process was applied for ranking 4 types of logging systems. • An environmental risk matrix with 28 risk factors in forest operations was made up

  9. Early Auditory Evoked Potential Is Modulated by Selective Attention and Related to Individual Differences in Visual Working Memory Capacity

    OpenAIRE

    Giuliano, Ryan J.; Karns, Christina M.; Neville, Helen J.; Hillyard, Steven A.

    2014-01-01

    A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and...

  10. Task-irrelevant distractors in the delay period interfere selectively with visual short-term memory for spatial locations.

    Science.gov (United States)

    Marini, Francesco; Scott, Jerry; Aron, Adam R; Ester, Edward F

    2017-07-01

    Visual short-term memory (VSTM) enables the representation of information in a readily accessible state. VSTM is typically conceptualized as a form of "active" storage that is resistant to interference or disruption, yet several recent studies have shown that under some circumstances task-irrelevant distractors may indeed disrupt performance. Here, we investigated how task-irrelevant visual distractors affected VSTM by asking whether distractors induce a general loss of remembered information or selectively interfere with memory representations. In a VSTM task, participants recalled the spatial location of a target visual stimulus after a delay in which distractors were presented on 75% of trials. Notably, the distractor's eccentricity always matched the eccentricity of the target, while in the critical conditions the distractor's angular position was shifted either clockwise or counterclockwise relative to the target. We then computed estimates of recall error for both eccentricity and polar angle. A general interference model would predict an effect of distractors on both polar angle and eccentricity errors, while a selective interference model would predict effects of distractors on angle but not on eccentricity errors. Results showed that for stimulus angle there was an increase in the magnitude and variability of recall errors. However, distractors had no effect on estimates of stimulus eccentricity. Our results suggest that distractors selectively interfere with VSTM for spatial locations.

  11. Selective Attention to Visual Stimuli Using Auditory Distractors Is Altered in Alpha-9 Nicotinic Receptor Subunit Knock-Out Mice.

    Science.gov (United States)

    Terreros, Gonzalo; Jorratt, Pascal; Aedo, Cristian; Elgoyhen, Ana Belén; Delano, Paul H

    2016-07-06

    During selective attention, subjects voluntarily focus their cognitive resources on a specific stimulus while ignoring others. Top-down filtering of peripheral sensory responses by higher structures of the brain has been proposed as one of the mechanisms responsible for selective attention. A prerequisite to accomplish top-down modulation of the activity of peripheral structures is the presence of corticofugal pathways. The mammalian auditory efferent system is a unique neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear bundle, and it has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear neurons in selective attention paradigms. Here, we trained wild-type and α-9 nicotinic receptor subunit knock-out (KO) mice, which lack cholinergic transmission between medial olivocochlear neurons and outer hair cells, in a two-choice visual discrimination task and studied the behavioral consequences of adding different types of auditory distractors. In addition, we evaluated the effects of contralateral noise on auditory nerve responses as a measure of the individual strength of the olivocochlear reflex. We demonstrate that KO mice have a reduced olivocochlear reflex strength and perform poorly in a visual selective attention paradigm. These results confirm that an intact medial olivocochlear transmission aids in ignoring auditory distraction during selective attention to visual stimuli. The auditory efferent system is a neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear system. It has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear

  12. Glycine-containing selective medium for isolation of Legionellaceae from environmental specimens.

    Science.gov (United States)

    Wadowsky, R M; Yee, R B

    1981-11-01

    Glycine, at a final concentration of 0.3%, has been shown to be an excellent selective agent for the isolation of Legionellaceae. Stock cultures of Legionella pneumophila were not inhibited on buffered charcoal-yeast extract agar containing the amino acid. Among the other Legionellaceae tested, only one of two strains of L. dumoffii and two of six strains of L. micdadei were appreciably inhibited. This medium permitted the isolation of L. pneumophila from environmental specimens with marked inhibition of many non-Legionellaceae bacteria. The selectivity of the medium was subsequently improved by the incorporation of vancomycin (5 microgram/ml) and polymyxin B (100 U/ml). This selective medium, glycine-vancomycin-polymyxin B agar, should facilitate the recovery of Legionellaceae from environmental sources.

  13. Effective Connectivity from Early Visual Cortex to Posterior Occipitotemporal Face Areas Supports Face Selectivity and Predicts Developmental Prosopagnosia.

    Science.gov (United States)

    Lohse, Michael; Garrido, Lucia; Driver, Jon; Dolan, Raymond J; Duchaine, Bradley C; Furl, Nicholas

    2016-03-30

    Face processing is mediated by interactions between functional areas in the occipital and temporal lobe, and the fusiform face area (FFA) and anterior temporal lobe play key roles in the recognition of facial identity. Individuals with developmental prosopagnosia (DP), a lifelong face recognition impairment, have been shown to have structural and functional neuronal alterations in these areas. The present study investigated how face selectivity is generated in participants with normal face processing, and how functional abnormalities associated with DP, arise as a function of network connectivity. Using functional magnetic resonance imaging and dynamic causal modeling, we examined effective connectivity in normal participants by assessing network models that include early visual cortex (EVC) and face-selective areas and then investigated the integrity of this connectivity in participants with DP. Results showed that a feedforward architecture from EVC to the occipital face area, EVC to FFA, and EVC to posterior superior temporal sulcus (pSTS) best explained how face selectivity arises in both controls and participants with DP. In this architecture, the DP group showed reduced connection strengths on feedforward connections carrying face information from EVC to FFA and EVC to pSTS. These altered network dynamics in DP contribute to the diminished face selectivity in the posterior occipitotemporal areas affected in DP. These findings suggest a novel view on the relevance of feedforward projection from EVC to posterior occipitotemporal face areas in generating cortical face selectivity and differences in face recognition ability. Areas of the human brain showing enhanced activation to faces compared to other objects or places have been extensively studied. However, the factors leading to this face selectively have remained mostly unknown. We show that effective connectivity from early visual cortex to posterior occipitotemporal face areas gives rise to face

  14. Consideration of environmental externality costs in electric utility resource selections and regulation

    International Nuclear Information System (INIS)

    Ottinger, R.L.

    1990-01-01

    A surprising number of state electric utility regulatory commissions (half) have started to require consideration of environmental externality costs in utility planning and resource selection. The principal rationale for doing so is that electric utility operations impose very real and large damages to human health and the environment which are not taken into account by traditional utility least cost planning, resource selection procedures, or by government pollution regulation. These failures effectively value the residual environmental costs to society of utility operations at zero. The likely future prospect for more stringent governmental pollution regulation renders imprudent the selection of resources without taking environmental externality costs into consideration. Most regulatory commissions requiring environmental externality consideration have left it to the utilities to compute the societal costs, although a few have either set those costs themselves or used a proxy adder to polluting resource costs (or bonus for non-polluting resources). These commissions have used control or pollution mitigation costs, rather than societal damage costs, in their regulatory computations. This paper recommends that damage costs be used where adequate studies exist to permit quantification, discusses the methodologies for their measurement, and describes the means that have been and might be used for their incorporation

  15. Effects of environmental variables on invasive amphibian activity: Using model selection on quantiles for counts

    Science.gov (United States)

    Muller, Benjamin J.; Cade, Brian S.; Schwarzkoph, Lin

    2018-01-01

    Many different factors influence animal activity. Often, the value of an environmental variable may influence significantly the upper or lower tails of the activity distribution. For describing relationships with heterogeneous boundaries, quantile regressions predict a quantile of the conditional distribution of the dependent variable. A quantile count model extends linear quantile regression methods to discrete response variables, and is useful if activity is quantified by trapping, where there may be many tied (equal) values in the activity distribution, over a small range of discrete values. Additionally, different environmental variables in combination may have synergistic or antagonistic effects on activity, so examining their effects together, in a modeling framework, is a useful approach. Thus, model selection on quantile counts can be used to determine the relative importance of different variables in determining activity, across the entire distribution of capture results. We conducted model selection on quantile count models to describe the factors affecting activity (numbers of captures) of cane toads (Rhinella marina) in response to several environmental variables (humidity, temperature, rainfall, wind speed, and moon luminosity) over eleven months of trapping. Environmental effects on activity are understudied in this pest animal. In the dry season, model selection on quantile count models suggested that rainfall positively affected activity, especially near the lower tails of the activity distribution. In the wet season, wind speed limited activity near the maximum of the distribution, while minimum activity increased with minimum temperature. This statistical methodology allowed us to explore, in depth, how environmental factors influenced activity across the entire distribution, and is applicable to any survey or trapping regime, in which environmental variables affect activity.

  16. Selected environmental considerations and their measuring parameters for nuclear power plant siting

    International Nuclear Information System (INIS)

    Norris, J.A.

    1975-01-01

    The site selection process for nuclear power stations encompasses a broad range of considerations. A categorization of these considerations consistent with the needs of the U. S. Atomic Energy Commission, as the regulatory agency, and of the utility company involves these major areas of concern. They are issues related to safety, environmental impact, and engineering/economics. The more important environmental considerations and their measuring parameters presented in this paper include biota, ecological systems and water quality, land use, aesthetics, water availability, and meteorology. (U.S.)

  17. Selected research works published in international journals on Vietnam environmental radioactivity

    International Nuclear Information System (INIS)

    2012-01-01

    The environmental radioactivity is object of many studies of the Vietnam Atomic Energy Institute (VINATOM). The VINATOM for long time has carried out monitoring of environmental radioactivity and application of isotopes in investigation of natural resources for socio-economic development in Vietnam. A lot of results of the studies in monitoring and application of radiation and isotopes have been presented at conferences. Some excellent research works have been published in prestigious international journals and selected to republish in this collection. The publication is expected to be as reference material for researchers, postgraduates in the field of environment protection. (NHA)

  18. Genomic selection using indicator traits to reduce the environmental impact of milk production

    DEFF Research Database (Denmark)

    Hansen Axelsson, H; Fikse, W F; Kargo, Morten

    2013-01-01

    The aim of this simulation study was to test the hypothesis that phenotype information of specific indicator traits of environmental importance recorded on a small-scale can be implemented in breeding schemes with genomic selection to reduce the environmental impact of milk production. A stochastic...... was, however, best in the scenarios where the genetic correlation between IT and EI was ≥0.30 and the accuracy of direct genomic value was ≥0.40. The genetic gain in EI was 26 to 34% higher when indicator traits such as greenhouse gases in the breath of the cow and methane recorded in respiration...... of direct genomic values will be reasonably high...

  19. You see what you have learned. Evidence for an interrelation of associative learning and visual selective attention.

    Science.gov (United States)

    Feldmann-Wüstefeld, Tobias; Uengoer, Metin; Schubö, Anna

    2015-11-01

    Besides visual salience and observers' current intention, prior learning experience may influence deployment of visual attention. Associative learning models postulate that observers pay more attention to stimuli previously experienced as reliable predictors of specific outcomes. To investigate the impact of learning experience on deployment of attention, we combined an associative learning task with a visual search task and measured event-related potentials of the EEG as neural markers of attention deployment. In the learning task, participants categorized stimuli varying in color/shape with only one dimension being predictive of category membership. In the search task, participants searched a shape target while disregarding irrelevant color distractors. Behavioral results showed that color distractors impaired performance to a greater degree when color rather than shape was predictive in the learning task. Neurophysiological results show that the amplified distraction was due to differential attention deployment (N2pc). Experiment 2 showed that when color was predictive for learning, color distractors captured more attention in the search task (ND component) and more suppression of color distractor was required (PD component). The present results thus demonstrate that priority in visual attention is biased toward predictive stimuli, which allows learning experience to shape selection. We also show that learning experience can overrule strong top-down control (blocked tasks, Experiment 3) and that learning experience has a longer-term effect on attention deployment (tasks on two successive days, Experiment 4). © 2015 Society for Psychophysiological Research.

  20. Infants' Selective Attention to Reliable Visual Cues in the Presence of Salient Distractors

    Science.gov (United States)

    Tummeltshammer, Kristen Swan; Mareschal, Denis; Kirkham, Natasha Z.

    2014-01-01

    With many features competing for attention in their visual environment, infants must learn to deploy attention toward informative cues while ignoring distractions. Three eye tracking experiments were conducted to investigate whether 6- and 8-month-olds (total N = 102) would shift attention away from a distractor stimulus to learn a cue-reward…

  1. MODULATION OF EVENT-RELATED POTENTIALS BY WORD REPETITION - THE ROLE OF VISUAL SELECTIVE ATTENTION

    NARCIS (Netherlands)

    OTTEN, LJ; RUGG, MD; DOYLE, MC

    1993-01-01

    Event-related potentials (ERPs) were recorded while subjects viewed visually presented words, some of which occurred twice. Each trial consisted of two colored letter strings, the requirement being to attend to and make a word/nonword discrimination for one of the strings. Attention was manipulated

  2. Visual assessment of BIPV retrofit design proposals for selected historical buildings using the saliency map method

    Directory of Open Access Journals (Sweden)

    Ran Xu

    2015-06-01

    Full Text Available With the increasing awareness of energy efficiency, many old buildings have to undergo a massive facade energy retrofit. How to predict the visual impact which solar installations on the aesthetic cultural value of these buildings has been a heated debate in Switzerland (and throughout the world. The usual evaluation method to describe the visual impact of BIPV is based on semantic and qualitative descriptors, and strongly dependent on personal preferences. The evaluation scale is therefore relative, flexible and imprecise. This paper proposes a new method to accurately measure the visual impact which BIPV installations have on a historical building by using the saliency map method. By imitating working principles of the human eye, it is measured how much the BIPV design proposals differ from the original building facade in the aspect of attracting human visual attention. The result is directly presented in a quantitative manner, and can be used to compare the fitness of different BIPV design proposals. The measuring process is numeric, objective and more precise.  

  3. Effect of Selected Balance Exercises on the Dynamic Balance of Children with Visual Impairments

    Science.gov (United States)

    Jazi, Shirin Davarpanah; Purrajabi, Fatemeh; Movahedi, Ahmadreza; Jalali, Shahin

    2012-01-01

    Introduction: Maintaining balance while walking is of utmost importance for individuals with visual impairments because deficits in dynamic balance have been associated with a high risk of falling. Thus, the primary aim of the study presented here was to determine whether balance training effects the dynamic balance of children with visual…

  4. The Selection of Tangible Symbols by Educators of Students with Visual Impairments and Additional Disabilities

    Science.gov (United States)

    Trief, Ellen; Bruce, Susan M.; Cascella, Paul W.

    2010-01-01

    Tangible symbols are objects or partial objects that can be physically manipulated and that share a perceptual relationship with what they represent, known as the referent. They make fewer demands on memory and representational ability, making them an appropriate expressive form of communication for individuals with visual impairments and…

  5. Is Visual Selective Attention in Deaf Individuals Enhanced or Deficient? The Case of the Useful Field of View

    Science.gov (United States)

    Dye, Matthew W. G.; Hauser, Peter C.; Bavelier, Daphne

    2009-01-01

    Background Early deafness leads to enhanced attention in the visual periphery. Yet, whether this enhancement confers advantages in everyday life remains unknown, as deaf individuals have been shown to be more distracted by irrelevant information in the periphery than their hearing peers. Here, we show that, in a complex attentional task, a performance advantage results for deaf individuals. Methodology/Principal Findings We employed the Useful Field of View (UFOV) which requires central target identification concurrent with peripheral target localization in the presence of distractors – a divided, selective attention task. First, the comparison of deaf and hearing adults with or without sign language skills establishes that deafness and not sign language use drives UFOV enhancement. Second, UFOV performance was enhanced in deaf children, but only after 11 years of age. Conclusions/Significance This work demonstrates that, following early auditory deprivation, visual attention resources toward the periphery slowly get augmented to eventually result in a clear behavioral advantage by pre-adolescence on a selective visual attention task. PMID:19462009

  6. Human prosaccades and antisaccades under risk: effects of penalties and rewards on visual selection and the value of actions.

    Science.gov (United States)

    Ross, M; Lanyon, L J; Viswanathan, J; Manoach, D S; Barton, J J S

    2011-11-24

    Monkey studies report greater activity in the lateral intraparietal area and more efficient saccades when targets coincide with the location of prior reward cues, even when cue location does not indicate which responses will be rewarded. This suggests that reward can modulate spatial attention and visual selection independent of the "action value" of the motor response. Our goal was first to determine whether reward modulated visual selection similarly in humans, and next, to discover whether reward and penalty differed in effect, if cue effects were greater for cognitively demanding antisaccades, and if financial consequences that were contingent on stimulus location had spatially selective effects. We found that motivational cues reduced all latencies, more for reward than penalty. There was an "inhibition-of-return"-like effect at the location of the cue, but unlike the results in monkeys, cue valence did not modify this effect in prosaccades, and the inhibition-of-return effect was slightly increased rather than decreased in antisaccades. When financial consequences were contingent on target location, locations without reward or penalty consequences lost the benefits seen in noncontingent trials, whereas locations with consequences maintained their gains. We conclude that unlike monkeys, humans show reward effects not on visual selection but on the value of actions. The human saccadic system has both the capacity to enhance responses to multiple locations simultaneously, and the flexibility to focus motivational enhancement only on locations with financial consequences. Reward is more effective than penalty, and both interact with the additional attentional demands of the antisaccade task. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Relationship between BOLD amplitude and pattern classification of orientation-selective activity in the human visual cortex

    Science.gov (United States)

    Tong, Frank; Harrison, Stephenie A.; Dewey, John A.; Kamitani, Yukiyasu

    2012-01-01

    Orientation-selective responses can be decoded from fMRI activity patterns in the human visual cortex, using multivariate pattern analysis (MVPA). To what extent do these feature-selective activity patterns depend on the strength and quality of the sensory input, and might the reliability of these activity patterns be predicted by the gross amplitude of the stimulus-driven BOLD response? Observers viewed oriented gratings that varied in luminance contrast (4, 20 or 100%) or spatial frequency (0.25, 1.0 or 4.0 cpd). As predicted, activity patterns in early visual areas led to better discrimination of orientations presented at high than low contrast, with greater effects of contrast found in area V1 than in V3. A second experiment revealed generally better decoding of orientations at low or moderate as compared to high spatial frequencies. Interestingly however, V1 exhibited a relative advantage at discriminating high spatial frequency orientations, consistent with the finer scale of representation in the primary visual cortex. In both experiments, the reliability of these orientation-selective activity patterns was well predicted by the average BOLD amplitude in each region of interest, as indicated by correlation analyses, as well as decoding applied to a simple model of voxel responses to simulated orientation columns. Moreover, individual differences in decoding accuracy could be predicted by the signal-to-noise ratio of an individual's BOLD response. Our results indicate that decoding accuracy can be well predicted by incorporating the amplitude of the BOLD response into simple simulation models of cortical selectivity; such models could prove useful in future applications of fMRI pattern classification. PMID:22917989

  8. Structuring the Environmental Experience Design Research Framework through Selected Aged Care Facility Data Analyses in Victoria

    Directory of Open Access Journals (Sweden)

    Nan Ma

    2017-11-01

    Full Text Available Humans relate to the living environment physically and psychologically. Environmental psychology has a rich developed history while experience design emerged recently in the industrial design domain. Nonetheless, these approaches have barely been merged, understood or implemented in architectural design practices. This study explored the correlation between experience design and environmental psychology. Moreover, it conducted literature reviews on theories about emotion, user experience design, experience design and environmental psychology, followed by the analyses of spatial settings and environmental quality data of a selected aged care facility in Victoria, Australia, as a case study. Accordingly, this study led to proposing a research framework on environmental experience design (EXD. It can be defined as a deliberate attempt that affiliates experience design and environmental psychology with creation of the built environment that should accommodate user needs and demands. The EXD research framework proposed in this study was tailored for transforming related design functions into the solutions that contribute to improving the built environment for user health and wellbeing.

  9. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Caroline [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5056 (United States); Grimaldi, Marina; Boulahtouf, Abdelhay [Institut de Recherche en Cancérologie de Montpellier, Institut National de la Santé de la Recherche Médicale U896, Institut Régional de Cancérologie de Montpellier, Université Montpellier 1, 34298 Montpellier (France); Pakdel, Farzad [Institut de Recherche sur la Santé, Environnement et Travail (IRSET), INSERM U1085, Université de Rennes 1, Rennes (France); Brion, François; Aït-Aïssa, Sélim [Unité Écotoxicologie In Vitro et In Vivo, INERIS, Parc ALATA, 60550 Verneuil-en-Halatte (France); Cavaillès, Vincent [Institut de Recherche en Cancérologie de Montpellier, Institut National de la Santé de la Recherche Médicale U896, Institut Régional de Cancérologie de Montpellier, Université Montpellier 1, 34298 Montpellier (France); Bourguet, William [U1054, Centre de Biochimie Structurale, CNRS UMR5048, Université Montpellier 1 et 2, 34290 Montpellier (France); Gustafsson, Jan-Ake [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5056 (United States); Department of Biosciences and Nutrition, Karolinska Institutet, 14183 Huddinge (Sweden); and others

    2014-10-01

    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28 °C as compared to 37 °C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology. - Highlights: • Zebrafish is increasingly used to study the effects of estrogens. • We assessed the activity of pharmaceutical and environmental estrogens on zfERs. • Environmental estrogens displayed greater potency for zfERα compared to zfERβs. • hERβ selective agonists displayed greater potency for zf

  10. Effects of task-irrelevant grouping on visual selection in partial report

    DEFF Research Database (Denmark)

    Lunau, Rasmus; Habekost, Thomas

    2017-01-01

    and the selection criterion was luminance. This effect was accompanied by impaired selectivity in unsorted-color trials. Overall, the results suggest that the benefit of task-irrelevant color grouping of targets is contingent on the processing locus of the selection criterion....... the color of the elements in these trials. In the sorted-color condition, the color of the display elements was arranged according to the selection criterion, and in the unsorted-color condition, colors were randomly assigned. The distractor cost was inferred by subtracting performance in partial......-report trials from performance in a control condition that had no distractors in the display. Across five experiments, we manipulated trial order, selection criterion, and exposure duration, and found that attentional selectivity was improved in sorted-color trials when the exposure duration was 200 ms...

  11. Visual Attention to Print-Salient and Picture-Salient Environmental Print in Young Children

    Science.gov (United States)

    Neumann, Michelle M.; Summerfield, Katelyn; Neumann, David L.

    2015-01-01

    Environmental print is composed of words and contextual cues such as logos and pictures. The salience of the contextual cues may influence attention to words and thus the potential of environmental print in promoting early reading development. The present study explored this by presenting pre-readers (n = 20) and beginning readers (n = 16) with…

  12. A decision-making support system to select forages according to environmental conditions in Colombia

    Directory of Open Access Journals (Sweden)

    Blanca Aurora Arce Barboza

    2013-07-01

    Full Text Available Low food supply is a major problem affecting a large percentage of the livestock population in Colombia and is largely associated to inappropriate choice of forage species; and thus not well adapted to the environmental conditions of a specific region. To mitigate this problem, without incurring increasing costs associated to changing environmental conditions, it is possible to match the adaptive capacity of species to the environment in which they grow. A decision support system was developed to select suitable forage species for a given environment. The system is based on the use of existing information about requirements of the species rather than specific experimentation. From the information gathered, a database was generated and implemented on ASP.NET in C # and SQL Server database. This system allows users to search and select pastures and forage species for specific soil and climatic conditions of a particular farm or region, through a user-friendly web platform.

  13. Selectivity in Postencoding Connectivity with High-Level Visual Cortex Is Associated with Reward-Motivated Memory.

    Science.gov (United States)

    Murty, Vishnu P; Tompary, Alexa; Adcock, R Alison; Davachi, Lila

    2017-01-18

    Reward motivation has been demonstrated to enhance declarative memory by facilitating systems-level consolidation. Although high-reward information is often intermixed with lower reward information during an experience, memory for high value information is prioritized. How is this selectivity achieved? One possibility is that postencoding consolidation processes bias memory strengthening to those representations associated with higher reward. To test this hypothesis, we investigated the influence of differential reward motivation on the selectivity of postencoding markers of systems-level memory consolidation. Human participants encoded intermixed, trial-unique memoranda that were associated with either high or low-value during fMRI acquisition. Encoding was interleaved with periods of rest, allowing us to investigate experience-dependent changes in connectivity as they related to later memory. Behaviorally, we found that reward motivation enhanced 24 h associative memory. Analysis of patterns of postencoding connectivity showed that, even though learning trials were intermixed, there was significantly greater connectivity with regions of high-level, category-selective visual cortex associated with high-reward trials. Specifically, increased connectivity of category-selective visual cortex with both the VTA and the anterior hippocampus predicted associative memory for high- but not low-reward memories. Critically, these results were independent of encoding-related connectivity and univariate activity measures. Thus, these findings support a model by which the selective stabilization of memories for salient events is supported by postencoding interactions with sensory cortex associated with reward. Reward motivation is thought to promote memory by supporting memory consolidation. Yet, little is known as to how brain selects relevant information for subsequent consolidation based on reward. We show that experience-dependent changes in connectivity of both the

  14. Here, KAPTUR This! Identifying and Selecting the Infrastructure Required to Support the Curation and Preservation of Visual Arts Research Data

    Directory of Open Access Journals (Sweden)

    Leigh Garrett

    2013-11-01

    Full Text Available Research data is increasingly perceived as a valuable resource and, with appropriate curation and preservation, it has much to offer learning, teaching, research, knowledge transfer and consultancy activities in the visual arts. However, very little is known about the curation and preservation of this data: none of the specialist arts institutions have research data management policies or infrastructure and anecdotal evidence suggests that practice is ad hoc, left to individual researchers and teams with little support or guidance. In addition, the curation and preservation of such diverse and complex digital resources as found in the visual arts is, in itself, challenging. Led by the Visual Arts Data Service, a research centre of the University for the Creative Arts, in collaboration with the Glasgow School of Art; Goldsmiths College, University of London; and University of the Arts London, and funded by JISC, the KAPTUR project (2011-2013 seeks to address the lack of awareness and explore the potential of research data management systems in the arts by discovering the nature of research data in the visual arts, investigating the current state of research data management, developing a model of best practice applicable to both specialist arts institutions and arts departments in multidisciplinary institutions, and by applying, testing and piloting the model with the four institutional partners. Utilising the findings of the KAPTUR user requirement and technical review, this paper will outline the method and selection of an appropriate research data management system for the visual arts and the issues the team encountered along the way.

  15. SORIOS – A method for evaluating and selecting environmental certificates and labels

    DEFF Research Database (Denmark)

    Kikkenborg Pedersen, Dennis; Dukovska-Popovska, Iskra; Ola Strandhagen, Jan

    2012-01-01

    This paper presents a general method for evaluating and selecting environmental certificates and labels for companies to use on products and services. The method is developed based on a case study using a Grounded Theory approach. The result is a generalized six-step method that features an initial...... searching strategy and an evaluation model that weighs the prerequisites, rewards and the organization of certificate or label against the strategic needs of a company....

  16. Determinants of Environmental Degradation under the Perspective of Globalization: A Panel Analysis of Selected MENA Nations

    OpenAIRE

    Audi, Marc; Ali, Amjad

    2018-01-01

    This paper has examined the determinants of environmental degradation under the perspective of globalization in the case of selected MENA nations (Jordan, United Arab Emirates, Saudi Arabia, Algeria, Qatar, Lebanon, Egypt, Bahrain, Iran, Morocco, Israel, Kuwait, Oman and Tunisia) over the period of 1980 to 2013. ADF - Fisher Chi-square, Im, Pesaran and Shin W-stat, Levin, Lin & Chu t*, and PP-Fisher Chi-square unit root tests are used for analyzing the stationarity of the variables. This stud...

  17. 2016 Billion-Ton Report: Environmental Sustainability Effects of Select Scenarios from Volume 1 (Volume 2)

    Energy Technology Data Exchange (ETDEWEB)

    Efroymson, R. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Langholtz, M. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, K. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stokes, B. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-13

    On behalf of all the authors and contributors, it is a great privilege to present the 2016 Billion-Ton Report (BT16), volume 2: Environmental Sustainability Effects of Select Scenarios from volume 1. This report represents the culmination of several years of collaborative effort among national laboratories, government agencies, academic institutions, and industry. BT16 was developed to support the U.S. Department of Energy’s efforts towards national goals of energy security and associated quality of life.

  18. Glycine-containing selective medium for isolation of Legionellaceae from environmental specimens.

    OpenAIRE

    Wadowsky, R M; Yee, R B

    1981-01-01

    Glycine, at a final concentration of 0.3%, has been shown to be an excellent selective agent for the isolation of Legionellaceae. Stock cultures of Legionella pneumophila were not inhibited on buffered charcoal-yeast extract agar containing the amino acid. Among the other Legionellaceae tested, only one of two strains of L. dumoffii and two of six strains of L. micdadei were appreciably inhibited. This medium permitted the isolation of L. pneumophila from environmental specimens with marked i...

  19. Illustrating sensitivity in environmental fate models using partitioning maps - application to selected contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, T.; Wania, F. [Univ. of Toronto at Scarborough - DPES, Toronto (Canada)

    2004-09-15

    Generic environmental multimedia fate models are important tools in the assessment of the impact of organic pollutants. Because of limited possibilities to evaluate generic models by comparison with measured data and the increasing regulatory use of such models, uncertainties of model input and output are of considerable concern. This led to a demand for sensitivity and uncertainty analyses for the outputs of environmental fate models. Usually, variations of model predictions of the environmental fate of organic contaminants are analyzed for only one or at most a few selected chemicals, even though parameter sensitivity and contribution to uncertainty are widely different for different chemicals. We recently presented a graphical method that allows for the comprehensive investigation of model sensitivity and uncertainty for all neutral organic chemicals simultaneously. This is achieved by defining a two-dimensional hypothetical ''chemical space'' as a function of the equilibrium partition coefficients between air, water, and octanol (K{sub OW}, K{sub AW}, K{sub OA}), and plotting sensitivity and/or uncertainty of a specific model result to each input parameter as function of this chemical space. Here we show how such sensitivity maps can be used to quickly identify the variables with the highest influence on the environmental fate of selected, chlorobenzenes, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs) and brominated flame retardents (BFRs).

  20. Basic Visual Disciplines in Heritage Conservation: Outline of Selected Perspectives in Teaching and Learning

    Science.gov (United States)

    Lobovikov-Katz, A.

    2017-08-01

    Acknowledgement of the value of a basic freehand sketch by the information and communication community of researchers and developers brought about the advanced developments for the use of sketches as free input to complicated processes of computerized visualization, so as to make them more widely accessible. However, a sharp reduction and even exclusion of this and other basic visual disciplines from education in sciences, technology, engineering and architecture dramatically reduces the number of future users of such applications. The unique needs of conservation of cultural heritage pose specific challenges as well as encourage the formulation of innovative development tasks in related areas of information and communication technologies (ICT). This paper claims that the introduction of basic visual disciplines to both communities is essential to the effectiveness of integration of heritage conservation needs and the advanced ICT development of conservation value, and beyond. It provides an insight into the challenges and advantages of introducing these subjects in a relevant educational context, presents some examples of their teaching and learning in the modern environment, including e-learning, and sketches perspectives to their application.

  1. Selective weighting of action-related feature dimensions in visual working memory.

    Science.gov (United States)

    Heuer, Anna; Schubö, Anna

    2017-08-01

    Planning an action primes feature dimensions that are relevant for that particular action, increasing the impact of these dimensions on perceptual processing. Here, we investigated whether action planning also affects the short-term maintenance of visual information. In a combined memory and movement task, participants were to memorize items defined by size or color while preparing either a grasping or a pointing movement. Whereas size is a relevant feature dimension for grasping, color can be used to localize the goal object and guide a pointing movement. The results showed that memory for items defined by size was better during the preparation of a grasping movement than during the preparation of a pointing movement. Conversely, memory for color tended to be better when a pointing movement rather than a grasping movement was being planned. This pattern was not only observed when the memory task was embedded within the preparation period of the movement, but also when the movement to be performed was only indicated during the retention interval of the memory task. These findings reveal that a weighting of information in visual working memory according to action relevance can even be implemented at the representational level during maintenance, demonstrating that our actions continue to influence visual processing beyond the perceptual stage.

  2. Detection vs. selection: integration of genetic, epigenetic and environmental cues in fluctuating environments.

    Science.gov (United States)

    McNamara, John M; Dall, Sasha R X; Hammerstein, Peter; Leimar, Olof

    2016-10-01

    There are many inputs during development that influence an organism's fit to current or upcoming environments. These include genetic effects, transgenerational epigenetic influences, environmental cues and developmental noise, which are rarely investigated in the same formal framework. We study an analytically tractable evolutionary model, in which cues are integrated to determine mature phenotypes in fluctuating environments. Environmental cues received during development and by the mother as an adult act as detection-based (individually observed) cues. The mother's phenotype and a quantitative genetic effect act as selection-based cues (they correlate with environmental states after selection). We specify when such cues are complementary and tend to be used together, and when using the most informative cue will predominate. Thus, we extend recent analyses of the evolutionary implications of subsets of these effects by providing a general diagnosis of the conditions under which detection and selection-based influences on development are likely to evolve and coexist. © 2016 John Wiley & Sons Ltd/CNRS.

  3. Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation.

    Science.gov (United States)

    Bengtsson-Palme, Johan; Larsson, D G Joakim

    2016-01-01

    There are concerns that selection pressure from antibiotics in the environment may accelerate the evolution and dissemination of antibiotic-resistant pathogens. Nevertheless, there is currently no regulatory system that takes such risks into account. In part, this is due to limited knowledge of environmental concentrations that might exert selection for resistant bacteria. To experimentally determine minimal selective concentrations in complex microbial ecosystems for all antibiotics would involve considerable effort. In this work, our aim was to estimate upper boundaries for selective concentrations for all common antibiotics, based on the assumption that selective concentrations a priori need to be lower than those completely inhibiting growth. Data on Minimal Inhibitory Concentrations (MICs) were obtained for 111 antibiotics from the public EUCAST database. The 1% lowest observed MICs were identified, and to compensate for limited species coverage, predicted lowest MICs adjusted for the number of tested species were extrapolated through modeling. Predicted No Effect Concentrations (PNECs) for resistance selection were then assessed using an assessment factor of 10 to account for differences between MICs and minimal selective concentrations. The resulting PNECs ranged from 8 ng/L to 64 μg/L. Furthermore, the link between taxonomic similarity between species and lowest MIC was weak. This work provides estimated upper boundaries for selective concentrations (lowest MICs) and PNECs for resistance selection for all common antibiotics. In most cases, PNECs for selection of resistance were below available PNECs for ecotoxicological effects. The generated PNECs can guide implementation of compound-specific emission limits that take into account risks for resistance promotion. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Adding value to innovation : Impressionism and the transformation of the selection system in visual arts

    NARCIS (Netherlands)

    Wijnberg, N.M.; Gemser, G.

    2000-01-01

    Valuation of cultural products tends to be problematic. In this paper, we provide insight into how valuation of cultural products takes place by describing the changing role and significance of different types of selection systems. Three basic types of selection systems are distinguished: market

  5. Signatures of environmental genetic adaptation pinpoint pathogens as the main selective pressure through human evolution.

    Directory of Open Access Journals (Sweden)

    Matteo Fumagalli

    2011-11-01

    Full Text Available Previous genome-wide scans of positive natural selection in humans have identified a number of non-neutrally evolving genes that play important roles in skin pigmentation, metabolism, or immune function. Recent studies have also shown that a genome-wide pattern of local adaptation can be detected by identifying correlations between patterns of allele frequencies and environmental variables. Despite these observations, the degree to which natural selection is primarily driven by adaptation to local environments, and the role of pathogens or other ecological factors as selective agents, is still under debate. To address this issue, we correlated the spatial allele frequency distribution of a large sample of SNPs from 55 distinct human populations to a set of environmental factors that describe local geographical features such as climate, diet regimes, and pathogen loads. In concordance with previous studies, we detected a significant enrichment of genic SNPs, and particularly non-synonymous SNPs associated with local adaptation. Furthermore, we show that the diversity of the local pathogenic environment is the predominant driver of local adaptation, and that climate, at least as measured here, only plays a relatively minor role. While background demography by far makes the strongest contribution in explaining the genetic variance among populations, we detected about 100 genes which show an unexpectedly strong correlation between allele frequencies and pathogenic environment, after correcting for demography. Conversely, for diet regimes and climatic conditions, no genes show a similar correlation between the environmental factor and allele frequencies. This result is validated using low-coverage sequencing data for multiple populations. Among the loci targeted by pathogen-driven selection, we found an enrichment of genes associated to autoimmune diseases, such as celiac disease, type 1 diabetes, and multiples sclerosis, which lends credence to the

  6. Sequence-selective single-molecule alkylation with a pyrrole-imidazole polyamide visualized in a DNA nanoscaffold.

    Science.gov (United States)

    Yoshidome, Tomofumi; Endo, Masayuki; Kashiwazaki, Gengo; Hidaka, Kumi; Bando, Toshikazu; Sugiyama, Hiroshi

    2012-03-14

    We demonstrate a novel strategy for visualizing sequence-selective alkylation of target double-stranded DNA (dsDNA) using a synthetic pyrrole-imidazole (PI) polyamide in a designed DNA origami scaffold. Doubly functionalized PI polyamide was designed by introduction of an alkylating agent 1-(chloromethyl)-5-hydroxy-1,2-dihydro-3H-benz[e]indole (seco-CBI) and biotin for sequence-selective alkylation at the target sequence and subsequent streptavidin labeling, respectively. Selective alkylation of the target site in the substrate DNA was observed by analysis using sequencing gel electrophoresis. For the single-molecule observation of the alkylation by functionalized PI polyamide using atomic force microscopy (AFM), the target position in the dsDNA (∼200 base pairs) was alkylated and then visualized by labeling with streptavidin. Newly designed DNA origami scaffold named "five-well DNA frame" carrying five different dsDNA sequences in its cavities was used for the detailed analysis of the sequence-selectivity and alkylation. The 64-mer dsDNAs were introduced to five individual wells, in which target sequence AGTXCCA/TGGYACT (XY = AT, TA, GC, CG) was employed as fully matched (X = G) and one-base mismatched (X = A, T, C) sequences. The fully matched sequence was alkylated with 88% selectivity over other mismatched sequences. In addition, the PI polyamide failed to attach to the target sequence lacking the alkylation site after washing and streptavidin treatment. Therefore, the PI polyamide discriminated the one mismatched nucleotide at the single-molecule level, and alkylation anchored the PI polyamide to the target dsDNA.

  7. A heuristic approach using multiple criteria for environmentally benign 3PLs selection

    Science.gov (United States)

    Kongar, Elif

    2005-11-01

    Maintaining competitiveness in an environment where price and quality differences between competing products are disappearing depends on the company's ability to reduce costs and supply time. Timely responses to rapidly changing market conditions require an efficient Supply Chain Management (SCM). Outsourcing logistics to third-party logistics service providers (3PLs) is one commonly used way of increasing the efficiency of logistics operations, while creating a more "core competency focused" business environment. However, this alone may not be sufficient. Due to recent environmental regulations and growing public awareness regarding environmental issues, 3PLs need to be not only efficient but also environmentally benign to maintain companies' competitiveness. Even though an efficient and environmentally benign combination of 3PLs can theoretically be obtained using exhaustive search algorithms, heuristics approaches to the selection process may be superior in terms of the computational complexity. In this paper, a hybrid approach that combines a multiple criteria Genetic Algorithm (GA) with Linear Physical Weighting Algorithm (LPPW) to be used in efficient and environmentally benign 3PLs is proposed. A numerical example is also provided to illustrate the method and the analyses.

  8. Sustainable manufacturing: Effect of material selection and design on the environmental impact in the manufacturing process

    International Nuclear Information System (INIS)

    Harun, Mohd Hazwan Syafiq; Salaam, Hadi Abdul; Taha, Zahari

    2013-01-01

    The environmental impact of a manufacturing process is also dependent on the selection of the material and design of a product. This is because the manufacturing of a product is directly connected to the amount of carbon emitted in consuming the electrical energy for that manufacturing process. The difference in the general properties of materials such as strength, hardness and impact will have significant effect on the power consumption of the machine used to complete the product. In addition the environmental impact can also be reduced if the proposed designs use less material. In this study, an LCA tool called Eco-It is used. Evaluate the environmental impact caused by manufacturing simple jig. A simple jig with 4 parts was used as a case study. Two experiments were carried out. The first experiment was to study the environmental effects of different material, and the second experiment was to study the environmental impact of different design. The materials used for the jig are Aluminium and mild steel. The results showed a decrease in the rate of carbon emissions by 60% when Aluminium is use instead from mild steel, and a decrease of 26% when the-design is modified

  9. Selection of facility location under environmental damage priority and using ELECTRE method.

    Science.gov (United States)

    Gundogdu, Ceren Erdin

    2011-03-01

    In the recent years, the environmental problems have reached to a vital extent, which is pushing the boundaries and far beyond daily evaluations. Industrial plants, the energy sources and uncontrolled release of pollutant gases (SO2, CO2 etc.) in the production stage have the greatest share in the occurrence of unfavorable environmental conditions. For this reason, the dimension of the problems that may arise in the production stage of industrial plants is directly related to the selection of facility location. In this study, geographical regions (a total of 7 regions) of our country have been analyzed in terms of environmental values based on their basins and the unfavorable environmental problems that are currently being experienced. Considered as such, with the directives of an expert group composed of nature scientists, the criteria and alternative areas are determined using the data gathered on ecosystem, basin characteristics, and land types. Since the primary goal is to keep the environmental damages at the minimum level, comprehensive definition of the problem is constructed by consultation of the expert group and the criteria are determined. Considering the fact that it will prevent the drawbacks generated by making decisions depending on certain stereotypes toa great extent, ELECTRE (Elimination and Choice Translating Reality English - Elimination Et Choix Traduisant la Realite) method is used to determine in which geographic region our country's industrial plants should be located.

  10. High temperature and bacteriophages can indirectly select for bacterial pathogenicity in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Ville-Petri Friman

    2011-03-01

    Full Text Available The coincidental evolution hypothesis predicts that traits connected to bacterial pathogenicity could be indirectly selected outside the host as a correlated response to abiotic environmental conditions or different biotic species interactions. To investigate this, an opportunistic bacterial pathogen, Serratia marcescens, was cultured in the absence and presence of the lytic bacteriophage PPV (Podoviridae at 25°C and 37°C for four weeks (N = 5. At the end, we measured changes in bacterial phage-resistance and potential virulence traits, and determined the pathogenicity of all bacterial selection lines in the Parasemia plantaginis insect model in vivo. Selection at 37°C increased bacterial motility and pathogenicity but only in the absence of phages. Exposure to phages increased the phage-resistance of bacteria, and this was costly in terms of decreased maximum population size in the absence of phages. However, this small-magnitude growth cost was not greater with bacteria that had evolved in high temperature regime, and no trade-off was found between phage-resistance and growth rate. As a result, phages constrained the evolution of a temperature-mediated increase in bacterial pathogenicity presumably by preferably infecting the highly motile and virulent bacteria. In more general perspective, our results suggest that the traits connected to bacterial pathogenicity could be indirectly selected as a correlated response by abiotic and biotic factors in environmental reservoirs.

  11. Contribution of correlated noise and selective decoding to choice probability measurements in extrastriate visual cortex.

    Science.gov (United States)

    Gu, Yong; Angelaki, Dora E; DeAngelis, Gregory C

    2014-07-01

    Trial by trial covariations between neural activity and perceptual decisions (quantified by choice Probability, CP) have been used to probe the contribution of sensory neurons to perceptual decisions. CPs are thought to be determined by both selective decoding of neural activity and by the structure of correlated noise among neurons, but the respective roles of these factors in creating CPs have been controversial. We used biologically-constrained simulations to explore this issue, taking advantage of a peculiar pattern of CPs exhibited by multisensory neurons in area MSTd that represent self-motion. Although models that relied on correlated noise or selective decoding could both account for the peculiar pattern of CPs, predictions of the selective decoding model were substantially more consistent with various features of the neural and behavioral data. While correlated noise is essential to observe CPs, our findings suggest that selective decoding of neuronal signals also plays important roles.

  12. Development of ion imprinted polymers for the selective extraction of lanthanides from environmental samples

    International Nuclear Information System (INIS)

    Moussa, Manel

    2016-01-01

    The analysis of the lanthanide ions present at trace level in complex environmental matrices requires often a purification and preconcentration step. The solid phase extraction (SPE) is the most used sample preparation technique. To improve the selectivity of this step, Ion Imprinted Polymers (IIPs) can be used as SPE solid supports. The aim of this work was the development of IIPs for the selective extraction of lanthanide ions from environmental samples. In a first part, IIPs were prepared according to the trapping approach using 5,7-dichloroquinoline-8-ol as non-vinylated ligand. For the first time, the loss of the trapped ligand during template ion removal and sedimentation steps was demonstrated by HPLC-UV. Moreover, this loss was not repeatable, which led to a lack of repeatability of the SPE profiles. It was then demonstrated that the trapping approach is not appropriate for the IIPs synthesis. In a second part, IIPs were synthesized by chemical immobilization of methacrylic acid as vinylated monomer. The repeatability of the synthesis and the SPE protocol were confirmed. A good selectivity of the IIPs for all the lanthanide ions was obtained. IIPs were successfully used to selectively extract lanthanide ions from tap and river water. Finally, IIPs were synthesized by chemical immobilization of methacrylic acid and 4-vinylpyridine as functional monomers and either a light (Nd 3+ ) or a heavy (Er 3+ ) lanthanide ion as template. Both kinds of IIPs led to a similar selectivity for all lanthanide ions. Nevertheless, this selectivity can be modified by changing the nature and the pH of the washing solution used in the SPE protocol. (author)

  13. Selective Attention Modulates the Direction of Audio-Visual Temporal Recalibration

    OpenAIRE

    Ikumi, Nara; Soto-Faraco, Salvador

    2014-01-01

    Temporal recalibration of cross-modal synchrony has been proposed as a mechanism to compensate for timing differences between sensory modalities. However, far from the rich complexity of everyday life sensory environments, most studies to date have examined recalibration on isolated cross-modal pairings. Here, we hypothesize that selective attention might provide an effective filter to help resolve which stimuli are selected when multiple events compete for recalibration. We addressed this qu...

  14. Adaptive attunement of selective covert attention to evolutionary-relevant emotional visual scenes

    OpenAIRE

    Fernández-Martín, Andrés (UNIR); Gutiérrez-García, Aida; Capafons, Juan; Calvo, Manuel G

    2017-01-01

    We investigated selective attention to emotional scenes in peripheral vision, as a function of adaptive relevance of scene affective content for male and female observers. Pairs of emotional neutral images appeared peripherally with perceptual stimulus differences controlled while viewers were fixating on a different stimulus in central vision. Early selective orienting was assessed by the probability of directing the first fixation towards either scene, and the time until first fixation. Emo...

  15. The perception of naturalness correlates with low-level visual features of environmental scenes.

    Directory of Open Access Journals (Sweden)

    Marc G Berman

    Full Text Available Previous research has shown that interacting with natural environments vs. more urban or built environments can have salubrious psychological effects, such as improvements in attention and memory. Even viewing pictures of nature vs. pictures of built environments can produce similar effects. A major question is: What is it about natural environments that produces these benefits? Problematically, there are many differing qualities between natural and urban environments, making it difficult to narrow down the dimensions of nature that may lead to these benefits. In this study, we set out to uncover visual features that related to individuals' perceptions of naturalness in images. We quantified naturalness in two ways: first, implicitly using a multidimensional scaling analysis and second, explicitly with direct naturalness ratings. Features that seemed most related to perceptions of naturalness were related to the density of contrast changes in the scene, the density of straight lines in the scene, the average color saturation in the scene and the average hue diversity in the scene. We then trained a machine-learning algorithm to predict whether a scene was perceived as being natural or not based on these low-level visual features and we could do so with 81% accuracy. As such we were able to reliably predict subjective perceptions of naturalness with objective low-level visual features. Our results can be used in future studies to determine if these features, which are related to naturalness, may also lead to the benefits attained from interacting with nature.

  16. D Web Visualization of Environmental Information - Integration of Heterogeneous Data Sources when Providing Navigation and Interaction

    Science.gov (United States)

    Herman, L.; Řezník, T.

    2015-08-01

    3D information is essential for a number of applications used daily in various domains such as crisis management, energy management, urban planning, and cultural heritage, as well as pollution and noise mapping, etc. This paper is devoted to the issue of 3D modelling from the levels of buildings to cities. The theoretical sections comprise an analysis of cartographic principles for the 3D visualization of spatial data as well as a review of technologies and data formats used in the visualization of 3D models. Emphasis was placed on the verification of available web technologies; for example, X3DOM library was chosen for the implementation of a proof-of-concept web application. The created web application displays a 3D model of the city district of Nový Lískovec in Brno, the Czech Republic. The developed 3D visualization shows a terrain model, 3D buildings, noise pollution, and other related information. Attention was paid to the areas important for handling heterogeneous input data, the design of interactive functionality, and navigation assistants. The advantages, limitations, and future development of the proposed concept are discussed in the conclusions.

  17. Remote Sensing and GIS Applied to the Landscape for the Environmental Restoration of Urbanizations by Means of 3D Virtual Reconstruction and Visualization (Salamanca, Spain

    Directory of Open Access Journals (Sweden)

    Antonio Miguel Martínez-Graña

    2016-01-01

    Full Text Available The key focus of this paper is to establish a procedure that combines the use of Geographical Information Systems (GIS and remote sensing in order to achieve simulation and modeling of the landscape impact caused by construction. The procedure should be easily and inexpensively developed. With the aid of 3D virtual reconstruction and visualization, this paper proposes that the technologies of remote sensing and GIS can be applied to the landscape for post-urbanization environmental restoration. The goal is to create a rural zone in an urban development sector that integrates the residential areas and local infrastructure into the surrounding natural environment in order to measure the changes to the preliminary urban design. The units of the landscape are determined by means of two cartographic methods: (1 indirect, using the components of the landscape; and (2 direct methods, using the landscape’s elements. The visual basins are calculated for the most transited by the population points, while establishing the zones that present major impacts for the urbanization of their landscape. Based on this, the different construction types are distributed (one-family houses, blocks of houses, etc., selecting the types of plant masses either with ornamentals or integration depending on the zone; integrating water channels, creating a water channel in recirculation and green spaces and leisure time facilities. The techniques of remote sensing and GIS allow for the visualization and modeling of the urbanization in 3D, simulating the virtual reality of the infrastructure as well as the actions that need to be taken for restoration, thereby providing at a low cost an understanding of landscape integration before it takes place.

  18. Ancestral informative marker selection and population structure visualization using sparse Laplacian eigenfunctions.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference.

  19. Lrit1, a Retinal Transmembrane Protein, Regulates Selective Synapse Formation in Cone Photoreceptor Cells and Visual Acuity.

    Science.gov (United States)

    Ueno, Akiko; Omori, Yoshihiro; Sugita, Yuko; Watanabe, Satoshi; Chaya, Taro; Kozuka, Takashi; Kon, Tetsuo; Yoshida, Satoyo; Matsushita, Kenji; Kuwahara, Ryusuke; Kajimura, Naoko; Okada, Yasushi; Furukawa, Takahisa

    2018-03-27

    In the vertebrate retina, cone photoreceptors play crucial roles in photopic vision by transmitting light-evoked signals to ON- and/or OFF-bipolar cells. However, the mechanisms underlying selective synapse formation in the cone photoreceptor pathway remain poorly understood. Here, we found that Lrit1, a leucine-rich transmembrane protein, localizes to the photoreceptor synaptic terminal and regulates the synaptic connection between cone photoreceptors and cone ON-bipolar cells. Lrit1-deficient retinas exhibit an aberrant morphology of cone photoreceptor pedicles, as well as an impairment of signal transmission from cone photoreceptors to cone ON-bipolar cells. Furthermore, we demonstrated that Lrit1 interacts with Frmpd2, a photoreceptor scaffold protein, and with mGluR6, an ON-bipolar cell-specific glutamate receptor. Additionally, Lrit1-null mice showed visual acuity impairments in their optokinetic responses. These results suggest that the Frmpd2-Lrit1-mGluR6 axis regulates selective synapse formation in cone photoreceptors and is essential for normal visual function. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Nayantara Santhi

    2007-11-01

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

  1. Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Science.gov (United States)

    Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

    2015-01-01

    Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

  2. Adolescents' selective visual attention for high-status peers: the role of perceiver status and gender.

    Science.gov (United States)

    Lansu, Tessa A M; Cillessen, Antonius H N; Karremans, Johan C

    2014-01-01

    Previous research has shown that adolescents' attention for a peer is determined by the peer's status. This study examined how it is also determined by the status of the perceiving adolescent, and the gender of both parties involved (perceiver and perceived). Participants were 122 early adolescents (M age = 11.0 years) who completed sociometric measures and eye-tracking recordings of visual fixations at pictures of high-status (popular) and low-status (unpopular) classmates. Automatic attention (first-gaze preference) and controlled attention (total gaze time) were measured. Target popularity was associated with both measures of attention. These associations were further moderated by perceiver popularity and perceiver and target gender. Popular adolescents attracted attention especially from other popular adolescents. Popular boys attracted attention especially from girls. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

  3. Environmental and economic evaluation of selective non-catalytic reduction of nitrogen oxides

    Science.gov (United States)

    Parchevskii, V. M.; Shchederkina, T. E.; Proshina, A. O.

    2017-11-01

    There are two groups of atmosphere protecting measures: technology (primary) and treatment (secondary). When burning high-calorie low-volatile brands of coals in the furnaces with liquid slag removal to achieve emission standards required joint use of these two methods, for example, staged combustion and selective non-catalytic reduction recovery (SNCR). For the economically intelligent combination of these two methods it is necessary to have information not only about the environmental performance of each method, but also the operating costs per unit of reduced emission. The authors of this report are made an environmental-economic analysis of SNCR on boiler Π-50P Kashirskaya power station. The obtained results about the dependence of costs from the load of the boiler and the mass emissions of nitrogen oxides then approximates into empirical formulas, is named as environmental and economic characteristics, which is suitable for downloading into controllers and other control devices for subsequent implementation of optimal control of emissions to ensure compliance with environmental regulations at the lowest cost at any load of the boiler.

  4. Modeling the effects of trophy selection and environmental disturbance on a simulated population of African lions.

    Science.gov (United States)

    Whitman, Karyl L; Starfield, Anthony M; Quadling, Henley; Packer, Craig

    2007-06-01

    Tanzania is a premier destination for trophy hunting of African lions (Panthera leo) and is home to the most extensive long-term study of unhunted lions. Thus, it provides a unique opportunity to apply data from a long-term field study to a conservation dilemma: How can a trophy-hunted species whose reproductive success is closely tied to social stability be harvested sustainably? We used an individually based, spatially explicit, stochastic model, parameterized with nearly 40 years of behavioral and demographic data on lions in the Serengeti, to examine the separate effects of trophy selection and environmental disturbance on the viability of a simulated lion population in response to annual harvesting. Female population size was sensitive to the harvesting of young males (> or = 3 years), whereas hunting represented a relatively trivial threat to population viability when the harvest was restricted to mature males (> or = 6 years). Overall model performance was robust to environmental disturbance and to errors in age assessment based on nose coloration as an index used to age potential trophies. Introducing an environmental disturbance did not eliminate the capacity to maintain a viable breeding population when harvesting only older males, and initially depleted populations recovered within 15-25 years after the disturbance to levels comparable to hunted populations that did not experience a catastrophic event. These results are consistent with empirical observations of lion resilience to environmental stochasticity.

  5. Spatial distribution of juvenile and adult stages of limnetic Cladocera in relation to selected environmental factors

    Directory of Open Access Journals (Sweden)

    Małgorzata Adamczuk

    2012-01-01

    Full Text Available Environmental factors have a varied impact on the development of juvenile and adult Cladocera, depending on their different physiological conditions and body size. The values of these factors alter spatially and temporarily, thus implying that they play a role in the spatial distribution of the pre-reproductive and potentially reproductive stages of cladocerans. The aim of the study was to determine seasonal and spatial variations in the distribution of juvenile and adult individuals of limnetic Cladocera in relation to selected physicochemical factors (temperature, conductivity, pH, concentration of dissolved oxygen, total organic carbon, total suspended solids and fish predation pressure (measured by Chesson’s coefficient λ in deep Lake Piaseczno (eastern Poland. Adult Cladocera displayed spatial distribution related to fish predation pressure. The species selectively eaten, B. coregoni and D. longispina, and non-selectively eaten, D. cucullata, selected the pelagic zone to exist, whereas those avoided by fish, D. brachyurum and B. longirostris, were evenly distributed in the littoral and pelagic zone. Juvenile cladocerans were strongly impacted by physico-chemical factors. Juvenile Daphnia, Diaphanosoma and B. longirostris showed preferences to biotic zones similar to the adults but differed in their habitat choices. Juvenile and adult stages of B. coregoni differed in their distribution, indicating that adult individuals impacted by high predation pressure alternatively modified their habitat selection. Principal component analysis (PCA ordination showed a seasonal tendency for the spatial segregation of the cladocerans, suggesting that possible competitive interactions between the studied cladocerans may also influence their distribution patterns.

  6. Visualization of Environmental Waste by Manufacturing : Equip VSM with Green Perspective

    OpenAIRE

    Hu, Juebin; Lu, Shan

    2011-01-01

    This thesis is a subtask of the research project “Green Production System”, which is jointly launched and run by Volvo/Volvo Technology, Haldex, Saab and All-Emballage J.E. AB as industrial party, and Mälardalen University as academic party. The whole project is dedicated to develop “green production system” to be a competitive mean to Swedish automotive and manufacturing industry through four work packages, which are “Wet preconditions and frames of a green production system”, “Visualization...

  7. Attentional selection in visual perception, memory and action: a quest for cross-domain integration

    Science.gov (United States)

    Schneider, Werner X.; Einhäuser, Wolfgang; Horstmann, Gernot

    2013-01-01

    For decades, the cognitive and neural sciences have benefitted greatly from a separation of mind and brain into distinct functional domains. The tremendous success of this approach notwithstanding, it is self-evident that such a view is incomplete. Goal-directed behaviour of an organism requires the joint functioning of perception, memory and sensorimotor control. A prime candidate for achieving integration across these functional domains are attentional processes. Consequently, this Theme Issue brings together studies of attentional selection from many fields, both experimental and theoretical, that are united in their quest to find overreaching integrative principles of attention between perception, memory and action. In all domains, attention is understood as combination of competition and priority control (‘bias’), with the task as a decisive driving factor to ensure coherent goal-directed behaviour and cognition. Using vision as the predominant model system for attentional selection, many studies of this Theme Issue focus special emphasis on eye movements as a selection process that is both a fundamental action and serves a key function in perception. The Theme Issue spans a wide range of methods, from measuring human behaviour in the real word to recordings of single neurons in the non-human primate brain. We firmly believe that combining such a breadth in approaches is necessary not only for attentional selection, but also to take the next decisive step in all of the cognitive and neural sciences: to understand cognition and behaviour beyond isolated domains. PMID:24018715

  8. Attentional selection in visual perception, memory and action: a quest for cross-domain integration.

    Science.gov (United States)

    Schneider, Werner X; Einhäuser, Wolfgang; Horstmann, Gernot

    2013-10-19

    For decades, the cognitive and neural sciences have benefitted greatly from a separation of mind and brain into distinct functional domains. The tremendous success of this approach notwithstanding, it is self-evident that such a view is incomplete. Goal-directed behaviour of an organism requires the joint functioning of perception, memory and sensorimotor control. A prime candidate for achieving integration across these functional domains are attentional processes. Consequently, this Theme Issue brings together studies of attentional selection from many fields, both experimental and theoretical, that are united in their quest to find overreaching integrative principles of attention between perception, memory and action. In all domains, attention is understood as combination of competition and priority control ('bias'), with the task as a decisive driving factor to ensure coherent goal-directed behaviour and cognition. Using vision as the predominant model system for attentional selection, many studies of this Theme Issue focus special emphasis on eye movements as a selection process that is both a fundamental action and serves a key function in perception. The Theme Issue spans a wide range of methods, from measuring human behaviour in the real word to recordings of single neurons in the non-human primate brain. We firmly believe that combining such a breadth in approaches is necessary not only for attentional selection, but also to take the next decisive step in all of the cognitive and neural sciences: to understand cognition and behaviour beyond isolated domains.

  9. Adaptive attunement of selective covert attention to evolutionary-relevant emotional visual scenes.

    Science.gov (United States)

    Fernández-Martín, Andrés; Gutiérrez-García, Aída; Capafons, Juan; Calvo, Manuel G

    2017-05-01

    We investigated selective attention to emotional scenes in peripheral vision, as a function of adaptive relevance of scene affective content for male and female observers. Pairs of emotional-neutral images appeared peripherally-with perceptual stimulus differences controlled-while viewers were fixating on a different stimulus in central vision. Early selective orienting was assessed by the probability of directing the first fixation towards either scene, and the time until first fixation. Emotional scenes selectively captured covert attention even when they were task-irrelevant, thus revealing involuntary, automatic processing. Sex of observers and specific emotional scene content (e.g., male-to-female-aggression, families and babies, etc.) interactively modulated covert attention, depending on adaptive priorities and goals for each sex, both for pleasant and unpleasant content. The attentional system exhibits domain-specific and sex-specific biases and attunements, probably rooted in evolutionary pressures to enhance reproductive and protective success. Emotional cues selectively capture covert attention based on their bio-social significance. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. To be selected or not to be selected : a modeling and behavioral study of the mechanisms underlying stimulus-driven and top-down visual attention

    NARCIS (Netherlands)

    Voort van der Kleij, van der Gwendid T.

    2007-01-01

    This thesis investigates the mechanisms of stimulus-driven visual attention (global saliency), the mechanisms of top-down visual attention, and the interaction between these mechanisms, in visual search. Following the outline of an existing model of top-down visual attention, namely the Closed-Loop

  11. Geospatial intelligence and visual classification of environmentally observed species in the Future Internet

    Science.gov (United States)

    Arbab-Zavar, B.; Chakravarthy, A.; Sabeur, Z. A.

    2012-04-01

    The rapid development of advanced smart communication tools with good quality and resolution video cameras, audio and GPS devices in the last few years shall lead to profound impacts on the way future environmental observations are conducted and accessed by communities. The resulting large scale interconnections of these "Future Internet Things" form a large environmental sensing network which will generate large volumes of quality environmental observations and at highly localised spatial scales. This enablement in environmental sensing at local scales will be of great importance to contribute in the study of fauna and flora in the near future, particularly on the effect of climate change on biodiversity in various regions of Europe and beyond. The Future Internet could also potentially become the de facto information space to provide participative real-time sensing by communities and improve our situation awarness of the effect of climate on local environments. In the ENVIROFI(2011-2013) Usage Area project in the FP7 FI-PPP programme, a set of requirements for specific (and generic) enablers is achieved with the potential establishement of participating community observatories of the future. In particular, the specific enablement of interest concerns the building of future interoperable services for the management of environmental data intelligently with tagged contextual geo-spatial information generated by multiple operators in communities (Using smart phones). The classification of observed species in the resulting images is achieved with structured data pre-processing, semantic enrichement using contextual geospatial information, and high level fusion with controlled uncertainty estimations. The returned identification of species is further improved using future ground truth corrections and learning by the specific enablers.

  12. In situ visualization of newly synthesized proteins in environmental microbes using amino acid tagging and click chemistry

    Science.gov (United States)

    Hatzenpichler, Roland; Scheller, Silvan; Tavormina, Patricia L; Babin, Brett M; Tirrell, David A; Orphan, Victoria J

    2014-01-01

    Here we describe the application of a new click chemistry method for fluorescent tracking of protein synthesis in individual microorganisms within environmental samples. This technique, termed bioorthogonal non-canonical amino acid tagging (BONCAT), is based on the in vivo incorporation of the non-canonical amino acid L-azidohomoalanine (AHA), a surrogate for l-methionine, followed by fluorescent labelling of AHA-containing cellular proteins by azide-alkyne click chemistry. BONCAT was evaluated with a range of phylogenetically and physiologically diverse archaeal and bacterial pure cultures and enrichments, and used to visualize translationally active cells within complex environmental samples including an oral biofilm, freshwater and anoxic sediment. We also developed combined assays that couple BONCAT with ribosomal RNA (rRNA)-targeted fluorescence in situ hybridization (FISH), enabling a direct link between taxonomic identity and translational activity. Using a methanotrophic enrichment culture incubated under different conditions, we demonstrate the potential of BONCAT-FISH to study microbial physiology in situ. A direct comparison of anabolic activity using BONCAT and stable isotope labelling by nano-scale secondary ion mass spectrometry (15NH3 assimilation) for individual cells within a sediment-sourced enrichment culture showed concordance between AHA-positive cells and 15N enrichment. BONCAT-FISH offers a fast, inexpensive and straightforward fluorescence microscopy method for studying the in situ activity of environmental microbes on a single-cell level. PMID:24571640

  13. Evaluation of selected predictive models and parameters for the environmental transport and dosimetry of radionuclides

    International Nuclear Information System (INIS)

    Miller, C.W.; Dunning, D.E. Jr.; Etnier, E.L.; Hoffman, F.O.; Little, C.A.; Meyer, H.R.; Shaeffer, D.L.; Till, J.E.

    1979-07-01

    Evaluations of selected predictive models and parameters used in the assessment of the environmental transport and dosimetry of radionuclides are summarized. Mator sections of this report include a validation of the Gaussian plume disperson model, comparison of the output of a model for the transport of 131 I from vegetation to milk with field data, validation of a model for the fraction of aerosols intercepted by vegetation, an evaluation of dose conversion factors for 232 Th, an evaluation of considering the effect of age dependency on population dose estimates, and a summary of validation results for hydrologic transport models

  14. Selection of IFE target materials from a safety and environmental perspective

    Energy Technology Data Exchange (ETDEWEB)

    Latkowski, J.F. E-mail: latkowski1@llnl.gov; Sanz, J.; Reyes, S.; Gomez del Rio, J

    2001-05-21

    Target materials for inertial fusion energy (IFE) power plant designs might be selected for a wide variety of reasons including wall absorption of driver energy, material opacity, cost and ease of fabrication. While each of these issues are of great importance, target materials should also be selected based upon their safety and environmental (S and E) characteristics. The present work focuses on the recycling, waste management and accident dose characteristics of potential target materials. If target materials are recycled so that the quantity is small, isotopic separation may be economically viable. Therefore, calculations have been completed for all stable isotopes for all elements from lithium to polonium. The results of these calculations are used to identify specific isotopes and elements that are most likely to be offensive as well as those most likely to be acceptable in terms of their S and E characteristics.

  15. Selection of IFE target materials from a safety and environmental perspective

    Science.gov (United States)

    Latkowski, J. F.; Sanz, J.; Reyes, S.; Gomez del Rio, J.

    2001-05-01

    Target materials for inertial fusion energy (IFE) power plant designs might be selected for a wide variety of reasons including wall absorption of driver energy, material opacity, cost and ease of fabrication. While each of these issues are of great importance, target materials should also be selected based upon their safety and environmental (S&E) characteristics. The present work focuses on the recycling, waste management and accident dose characteristics of potential target materials. If target materials are recycled so that the quantity is small, isotopic separation may be economically viable. Therefore, calculations have been completed for all stable isotopes for all elements from lithium to polonium. The results of these calculations are used to identify specific isotopes and elements that are most likely to be offensive as well as those most likely to be acceptable in terms of their S&E characteristics.

  16. An overview of safety and environmental considerations in the selection of materials for fusion facilities

    International Nuclear Information System (INIS)

    Petti, D.A.; Piet, S.J.; Seki, Y.

    1996-01-01

    Safety and environmental considerations can play a large role in the selection of fusion materials. In this paper, we review the attributes of different structural, plasma facing, and breeding materials from a safety perspective and discuss some generic waste management issues as they relate to fusion materials in general. Specific safety concerns exist for each material that must be dealt with in fusion facility design. Low activation materials offer inherent safety benefits compared with conventional materials, but more work is needed before these materials have the requisite certified databases. In the interim, the international thermonuclear experimental reactor (ITER) has selected more conventional materials and is showing that the safety concerns with these materials can be addressed by proper attention to design. In the area of waste management disposal criteria differ by country. However, the criteria are all very strict making disposal of fusion components difficult. As a result, recycling has gained increasing attention. (orig.)

  17. INTEGRATING VISUALIZATION AND MULTI-ATTRIBUTE UTILITY THEORY FOR ONLINE PRODUCT SELECTION

    OpenAIRE

    CHUREE THEETRANONT; PETER HADDAWY; DONYAPRUETH KRAIRIT

    2007-01-01

    Effectively selling products online is a challenging task. Today's product domains often contain a dizzying variety of brands and models with highly complex sets of characteristics. This paper addresses the problem of supporting product search and selection in domains containing large numbers of alternatives with complex sets of features. A number of online shopping websites provide product choice assistance by making direct use of Multi-Attribute Utility Theory (MAUT). While the MAUT approac...

  18. Environmental risk assessment of selected organic chemicals based on TOC test and QSAR estimation models.

    Science.gov (United States)

    Chi, Yulang; Zhang, Huanteng; Huang, Qiansheng; Lin, Yi; Ye, Guozhu; Zhu, Huimin; Dong, Sijun

    2018-02-01

    Environmental risks of organic chemicals have been greatly determined by their persistence, bioaccumulation, and toxicity (PBT) and physicochemical properties. Major regulations in different countries and regions identify chemicals according to their bioconcentration factor (BCF) and octanol-water partition coefficient (Kow), which frequently displays a substantial correlation with the sediment sorption coefficient (Koc). Half-life or degradability is crucial for the persistence evaluation of chemicals. Quantitative structure activity relationship (QSAR) estimation models are indispensable for predicting environmental fate and health effects in the absence of field- or laboratory-based data. In this study, 39 chemicals of high concern were chosen for half-life testing based on total organic carbon (TOC) degradation, and two widely accepted and highly used QSAR estimation models (i.e., EPI Suite and PBT Profiler) were adopted for environmental risk evaluation. The experimental results and estimated data, as well as the two model-based results were compared, based on the water solubility, Kow, Koc, BCF and half-life. Environmental risk assessment of the selected compounds was achieved by combining experimental data and estimation models. It was concluded that both EPI Suite and PBT Profiler were fairly accurate in measuring the physicochemical properties and degradation half-lives for water, soil, and sediment. However, the half-lives between the experimental and the estimated results were still not absolutely consistent. This suggests deficiencies of the prediction models in some ways, and the necessity to combine the experimental data and predicted results for the evaluation of environmental fate and risks of pollutants. Copyright © 2016. Published by Elsevier B.V.

  19. Environmental risk perception from visual cues: the psychophysics of tornado risk perception

    Science.gov (United States)

    Dewitt, Barry; Fischhoff, Baruch; Davis, Alexander; Broomell, Stephen B.

    2015-12-01

    Lay judgments of environmental risks are central to both immediate decisions (e.g., taking shelter from a storm) and long-term ones (e.g., building in locations subject to storm surges). Using methods from quantitative psychology, we provide a general approach to studying lay perceptions of environmental risks. As a first application of these methods, we investigate a setting where lay decisions have not taken full advantage of advances in natural science understanding: tornado forecasts in the US and Canada. Because official forecasts are imperfect, members of the public must often evaluate the risks on their own, by checking environmental cues (such as cloud formations) before deciding whether to take protective action. We study lay perceptions of cloud formations, demonstrating an approach that could be applied to other environmental judgments. We use signal detection theory to analyse how well people can distinguish tornadic from non-tornadic clouds, and multidimensional scaling to determine how people make these judgments. We find that participants (N = 400 recruited from Amazon Mechanical Turk) have heuristics that generally serve them well, helping participants to separate tornadic from non-tornadic clouds, but which also lead them to misjudge the tornado risk of certain cloud types. The signal detection task revealed confusion regarding shelf clouds, mammatus clouds, and clouds with upper- and mid-level tornadic features, which the multidimensional scaling task suggested was the result of participants focusing on the darkness of the weather scene and the ease of discerning its features. We recommend procedures for training (e.g., for storm spotters) and communications (e.g., tornado warnings) that will reduce systematic misclassifications of tornadicity arising from observers’ reliance on otherwise useful heuristics.

  20. DOCUMENTATION OF HISTORICAL UNDERGROUND OBJECT IN SKORKOV VILLAGE WITH SELECTED MEASURING METHODS, DATA ANALYSIS AND VISUALIZATION

    Directory of Open Access Journals (Sweden)

    A. Dlesk

    2016-06-01

    Full Text Available The author analyzes current methods of 3D documentation of historical tunnels in Skorkov village, which lies at the Jizera river, approximately 30 km away from Prague. The area is known as a former military camp from Thirty Years’ War in 17th Century. There is an extensive underground compound with one entrance corridor and two transverse, situated approximately 2 to 5 m under the local development. The object has been partly documented by geodetic polar method, intersection photogrammetry, image-based modelling and laser scanning. Data have been analyzed and methods have been compared. Then the 3D model of object has been created and compound with cadastral data, orthophoto, historical maps and digital surface model which was made by photogrammetric method using remotely piloted aircraft system. Then the measuring has been realized with ground penetrating radar. Data have been analyzed and the result compared with real status. All the data have been combined and visualized into one 3D model. Finally, the discussion about advantages and disadvantages of used measuring methods has been livened up. The tested methodology has been also used for other documentation of historical objects in this area. This project has been created as a part of research at EuroGV. s.r.o. Company lead by Ing. Karel Vach CSc. in cooperation with prof. Dr. Ing. Karel Pavelka from Czech Technical University in Prague and Miloš Gavenda, the renovator.

  1. Selective visual attention and motivation: the consequences of value learning in an attentional blink task.

    Science.gov (United States)

    Raymond, Jane E; O'Brien, Jennifer L

    2009-08-01

    Learning to associate the probability and value of behavioral outcomes with specific stimuli (value learning) is essential for rational decision making. However, in demanding cognitive conditions, access to learned values might be constrained by limited attentional capacity. We measured recognition of briefly presented faces seen previously in a value-learning task involving monetary wins and losses; the recognition task was performed both with and without constraints on available attention. Regardless of available attention, recognition was substantially enhanced for motivationally salient stimuli (i.e., stimuli highly predictive of outcomes), compared with equally familiar stimuli that had weak or no motivational salience, and this effect was found regardless of valence (win or loss). However, when attention was constrained (because stimuli were presented during an attentional blink, AB), valence determined recognition; win-associated faces showed no AB, but all other faces showed large ABs. Motivational salience acts independently of attention to modulate simple perceptual decisions, but when attention is limited, visual processing is biased in favor of reward-associated stimuli.

  2. Documentation of Historical Underground Object in Skorkov Village with Selected Measuring Methods, Data Analysis and Visualization

    Science.gov (United States)

    Dlesk, A.

    2016-06-01

    The author analyzes current methods of 3D documentation of historical tunnels in Skorkov village, which lies at the Jizera river, approximately 30 km away from Prague. The area is known as a former military camp from Thirty Years' War in 17th Century. There is an extensive underground compound with one entrance corridor and two transverse, situated approximately 2 to 5 m under the local development. The object has been partly documented by geodetic polar method, intersection photogrammetry, image-based modelling and laser scanning. Data have been analyzed and methods have been compared. Then the 3D model of object has been created and compound with cadastral data, orthophoto, historical maps and digital surface model which was made by photogrammetric method using remotely piloted aircraft system. Then the measuring has been realized with ground penetrating radar. Data have been analyzed and the result compared with real status. All the data have been combined and visualized into one 3D model. Finally, the discussion about advantages and disadvantages of used measuring methods has been livened up. The tested methodology has been also used for other documentation of historical objects in this area. This project has been created as a part of research at EuroGV. s.r.o. Company lead by Ing. Karel Vach CSc. in cooperation with prof. Dr. Ing. Karel Pavelka from Czech Technical University in Prague and Miloš Gavenda, the renovator.

  3. Visualization of Operational Performance of Grid-Connected PV Systems in Selected European Countries

    Directory of Open Access Journals (Sweden)

    Bala Bhavya Kausika

    2018-05-01

    Full Text Available This paper presents the results of the analyses of operational performance of small-sized residential PV systems, connected to the grid, in the Netherlands and some other European countries over three consecutive years. Web scraping techniques were employed to collect detailed yield data at high time resolution (5–15 min from a large number (31,844 of systems with 741 MWp of total capacity, delivering data continuously for at least one year. Annual system yield data was compared from small and medium-sized installations. Cartography and spatial analysis techniques in a geographic information system (GIS were used to visualize yield and performance ratio, which greatly facilitates the assessment of performance for geographically scattered systems. Variations in yield and performance ratios over the years were observed with higher values in 2015 due to higher irradiation values. The potential of specific yield and performance maps lies in the updating of monitoring databases, quality control of data, and availability of irradiation data. The automatic generation of performance maps could be a trend in future mapping.

  4. The effects of memory load and stimulus relevance on the EEG during a visual selective memory search task : An ERP and ERD/ERS study

    NARCIS (Netherlands)

    Gomarus, HK; Althaus, M; Wijers, AA; Minderaa, RB

    Objective: Psychophysiological correlates of selective attention and working memory were investigated in a group of 18 healthy children using a visually presented selective mernory search task. Methods: Subjects had to memorize one (load 1) or 3 (load3) letters (memory set) and search for these

  5. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Lauri Mikonranta

    Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  6. Genomic and environmental selection patterns in two distinct lettuce crop–wild hybrid crosses

    Science.gov (United States)

    Hartman, Yorike; Uwimana, Brigitte; Hooftman, Danny A P; Schranz, Michael E; van de Wiel, Clemens C M; Smulders, Marinus J M; Visser, Richard G F; van Tienderen, Peter H

    2013-01-01

    Genomic selection patterns and hybrid performance influence the chance that crop (trans)genes can spread to wild relatives. We measured fitness(-related) traits in two different field environments employing two different crop–wild crosses of lettuce. We performed quantitative trait loci (QTL) analyses and estimated the fitness distribution of early- and late-generation hybrids. We detected consistent results across field sites and crosses for a fitness QTL at linkage group 7, where a selective advantage was conferred by the wild allele. Two fitness QTL were detected on linkage group 5 and 6, which were unique to one of the crop–wild crosses. Average hybrid fitness was lower than the fitness of the wild parent, but several hybrid lineages outperformed the wild parent, especially in a novel habitat for the wild type. In early-generation hybrids, this may partly be due to heterosis effects, whereas in late-generation hybrids transgressive segregation played a major role. The study of genomic selection patterns can identify crop genomic regions under negative selection across multiple environments and cultivar–wild crosses that might be applicable in transgene mitigation strategies. At the same time, results were cultivar-specific, so that a case-by-case environmental risk assessment is still necessary, decreasing its general applicability. PMID:23789025

  7. Genomic and environmental selection patterns in two distinct lettuce crop-wild hybrid crosses.

    Science.gov (United States)

    Hartman, Yorike; Uwimana, Brigitte; Hooftman, Danny A P; Schranz, Michael E; van de Wiel, Clemens C M; Smulders, Marinus J M; Visser, Richard G F; van Tienderen, Peter H

    2013-06-01

    Genomic selection patterns and hybrid performance influence the chance that crop (trans)genes can spread to wild relatives. We measured fitness(-related) traits in two different field environments employing two different crop-wild crosses of lettuce. We performed quantitative trait loci (QTL) analyses and estimated the fitness distribution of early- and late-generation hybrids. We detected consistent results across field sites and crosses for a fitness QTL at linkage group 7, where a selective advantage was conferred by the wild allele. Two fitness QTL were detected on linkage group 5 and 6, which were unique to one of the crop-wild crosses. Average hybrid fitness was lower than the fitness of the wild parent, but several hybrid lineages outperformed the wild parent, especially in a novel habitat for the wild type. In early-generation hybrids, this may partly be due to heterosis effects, whereas in late-generation hybrids transgressive segregation played a major role. The study of genomic selection patterns can identify crop genomic regions under negative selection across multiple environments and cultivar-wild crosses that might be applicable in transgene mitigation strategies. At the same time, results were cultivar-specific, so that a case-by-case environmental risk assessment is still necessary, decreasing its general applicability.

  8. A QSAR Study of Environmental Estrogens Based on a Novel Variable Selection Method

    Directory of Open Access Journals (Sweden)

    Aiqian Zhang

    2012-05-01

    Full Text Available A large number of descriptors were employed to characterize the molecular structure of 53 natural, synthetic, and environmental chemicals which are suspected of disrupting endocrine functions by mimicking or antagonizing natural hormones and may thus pose a serious threat to the health of humans and wildlife. In this work, a robust quantitative structure-activity relationship (QSAR model with a novel variable selection method has been proposed for the effective estrogens. The variable selection method is based on variable interaction (VSMVI with leave-multiple-out cross validation (LMOCV to select the best subset. During variable selection, model construction and assessment, the Organization for Economic Co-operation and Development (OECD principles for regulation of QSAR acceptability were fully considered, such as using an unambiguous multiple-linear regression (MLR algorithm to build the model, using several validation methods to assessment the performance of the model, giving the define of applicability domain and analyzing the outliers with the results of molecular docking. The performance of the QSAR model indicates that the VSMVI is an effective, feasible and practical tool for rapid screening of the best subset from large molecular descriptors.

  9. Biological Principles and Threshold Concepts for Understanding Natural Selection. Implications for Developing Visualizations as a Pedagogic Tool

    Science.gov (United States)

    Tibell, Lena A. E.; Harms, Ute

    2017-11-01

    Modern evolutionary theory is both a central theory and an integrative framework of the life sciences. This is reflected in the common references to evolution in modern science education curricula and contexts. In fact, evolution is a core idea that is supposed to support biology learning by facilitating the organization of relevant knowledge. In addition, evolution can function as a pivotal link between concepts and highlight similarities in the complexity of biological concepts. However, empirical studies in many countries have for decades identified deficiencies in students' scientific understanding of evolution mainly focusing on natural selection. Clearly, there are major obstacles to learning natural selection, and we argue that to overcome them, it is essential to address explicitly the general abstract concepts that underlie the biological processes, e.g., randomness or probability. Hence, we propose a two-dimensional framework for analyzing and structuring teaching of natural selection. The first—purely biological—dimension embraces the three main principles variation, heredity, and selection structured in nine key concepts that form the core idea of natural selection. The second dimension encompasses four so-called thresholds, i.e., general abstract and/or non-perceptual concepts: randomness, probability, spatial scales, and temporal scales. We claim that both of these dimensions must be continuously considered, in tandem, when teaching evolution in order to allow development of a meaningful understanding of the process. Further, we suggest that making the thresholds tangible with the aid of appropriate kinds of visualizations will facilitate grasping of the threshold concepts, and thus, help learners to overcome the difficulties in understanding the central theory of life.

  10. Selective visual attention to drive cognitive brain machine interfaces: from concepts to neurofeedback and rehabilitation applications

    Directory of Open Access Journals (Sweden)

    Elaine eAstrand

    2014-08-01

    Full Text Available Brain Machine Interfaces (BMI using motor cortical activity to drive an external effector like a screen cursor or a robotic arm have seen enormous success and proven their great rehabilitation potential. An emerging parallel effort is now directed to BMIs controlled by endogenous cognitive activity, also called cognitive BMIs. While more challenging, this approach opens new dimensions to the rehabilitation of cognitive disorders. In the present work, we focus on BMIs driven by visuospatial attention signals and we provide a critical review of these studies in the light of the accumulated knowledge about the psychophysics, anatomy and neurophysiology of visual spatial attention. Importantly, we provide a unique comparative overview of the several studies, ranging from noninvasive to invasive human and non-human primates studies, that decode attention-related information from ongoing neuronal activity. We discuss these studies in the light of the challenges attention-driven cognitive BMIs have to face. In a second part of the review, we discuss past and current attention-based neurofeedback studies, describing both the covert effects of neurofeedback onto neuronal activity and its overt behavioral effects. Importantly, we compare neurofeedback studies based on the amplitude of cortical activity to studies based on the enhancement of cortical information content. Last, we discuss several lines of future research and applications for attention-driven cognitive BCIs, including the rehabilitation of cognitive deficits, restored communication in locked-in patients, and open-field applications for enhanced cognition in normal subjects. The core motivation of this work is the key idea that the improvement of current cognitive BMIs for therapeutic and open field applications needs to be grounded in a proper interdisciplinary understanding of the physiology of the cognitive function of interest, be it spatial attention, working memory or any other

  11. Preliminary assessment of RTR and visual characterization for selected waste categories

    International Nuclear Information System (INIS)

    Ziegler, D.L.

    1992-01-01

    The first transuranic (TRU) waste shipped to the Waste Isolation Pilot Plant (WIPP) will be for the WIPP Experimental Program. The purpose of the Experimental Program is to determine the gas generation rates and potential for gas generation by the waste after it has been permanently stored at the WIPP. The first phase of these tests will be performed at WIPP with test bins that have been filled and sealed in accordance with the test plan for bin scale tests. A second phase of the testing, the Alcove Test, will involve drummed waste placed in sealed rooms within WIPP. A preliminary test was conducted at the Rocky Flats Plant (RFP) to evaluate potential methods for use in the characterization of waste. The waste material types to be identified were as defined in the bin-scale test plan -- Cellulosics, Plastic, Rubber, Corroding Metal/Steel, Corroding Metal/Aluminum, Non-corroding Metal, Solid Inorganic, Inorganic Sludges, other organics and Cements. A total of 19 drums representing eleven different waste types (Rocky Flats Plant -- Identification Description Codes (IDC)) and seven different TRUCON Code materials were evaluated. They included Dry Combustibles, Wet Combustibles, Plastic, light Metal, Glass (Non-Raschig Ring). Raschig Rings, M g O crucibles, HEPA Filters, Insulation, Leaded Dry Box Gloves, and Graphite. These Identification Description Codes were chosen because of their abundance on plant, as well as the variability in drum loading techniques. The goal of this test was to evaluate the effectiveness of RTR inspection and visual inspection as characterization methods for waste. In addition, gas analysis of the head space was conducted to provide an indication of the types of gas generated

  12. Effects of working memory load on visual selective attention: Behavioral and electrophysiological evidence

    Directory of Open Access Journals (Sweden)

    Nikki ePratt

    2011-06-01

    Full Text Available Working memory and attention interact in a way that enables us to focus on relevant items and maintain current goals. The influence of working memory on attention has been noted in several studies using dual task designs. Multitasking increases the demands on working memory and reduces the amount of resources available for cognitive control functions such as resolving stimulus conflict. However, few studies have investigated the temporal activation of the cortex while multitasking. The present study addresses the extent to which working memory load influences early (P1 and late (P300 attention-sensitive event-related potential (ERP components using a dual task paradigm. Participants performed an arrow flanker task alone (single task condition or concurrently with a Sternberg memory task (dual task condition. In the flanker task, participants responded to the direction of a central arrow surrounded by congruent or incongruent arrows. In the dual task condition, participants were presented with a Sternberg task that consisted of either 4 or 7 consonants to remember prior to a short block of flanker trials. Participants were slower and less accurate on incongruent versus congruent trials. Furthermore, accuracy on incongruent trials was reduced in both dual task conditions. Likewise, P300 amplitude to incongruent flanker stimuli decreased when working memory load increased. These findings suggest that interference from incongruent flankers was more difficult to suppress when working memory was taxed. In addition, P1 amplitude was diminished on all flanker trials in the dual task condition. This result indicates that top-down attentional control over early visual processing is diminished by increasing demands on working memory. Both the behavioral and electrophysiological results suggest that working memory is critical in maintaining attentional focus and resolving conflict.

  13. Chronic cannabis use and ERP correlates of visual selective attention during the performance of a flanker go/nogo task.

    Science.gov (United States)

    Nicholls, Clare; Bruno, Raimondo; Matthews, Allison

    2015-09-01

    The aim of the study was to investigate the relationship between chronic cannabis use and visual selective attention by examining event-related potentials (ERPs) during the performance of a flanker go/nogo task. Male participants were 15 chronic cannabis users (minimum two years use, at least once per week) and 15 drug naive controls. Cannabis users showed longer reaction times compared to controls with equivalent accuracy. Cannabis users also showed a reduction in the N2 'nogo effect' at frontal sites, particularly for incongruent stimuli, and particularly in the right hemisphere. This suggests differences between chronic cannabis users and controls in terms of inhibitory processing within the executive control network, and may implicate the right inferior frontal cortex. There was also preliminary evidence for differences in early selective attention, with controls but not cannabis users showing modulation of N1 amplitude by flanker congruency. Further investigation is required to examine the potential reversibility of these residual effects after long-term abstinence and to examine the role of early selective attention mechanisms in more detail. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Selectivity of N170 for visual words in the right hemisphere: Evidence from single-trial analysis.

    Science.gov (United States)

    Yang, Hang; Zhao, Jing; Gaspar, Carl M; Chen, Wei; Tan, Yufei; Weng, Xuchu

    2017-08-01

    Neuroimaging and neuropsychological studies have identified the involvement of the right posterior region in the processing of visual words. Interestingly, in contrast, ERP studies of the N170 typically demonstrate selectivity for words more strikingly over the left hemisphere. Why is right hemisphere selectivity for words during the N170 epoch typically not observed, despite the clear involvement of this region in word processing? One possibility is that amplitude differences measured on averaged ERPs in previous studies may have been obscured by variation in peak latency across trials. This study examined this possibility by using single-trial analysis. Results show that words evoked greater single-trial N170s than control stimuli in the right hemisphere. Additionally, we observed larger trial-to-trial variability on N170 peak latency for words as compared to control stimuli over the right hemisphere. Results demonstrate that, in contrast to much of the prior literature, the N170 can be selective to words over the right hemisphere. This discrepancy is explained in terms of variability in trial-to-trial peak latency for responses to words over the right hemisphere. © 2017 Society for Psychophysiological Research.

  15. Methodology for the selection of alternatives to the waterfall division of hydro graphical basin, considering environmental impacts

    International Nuclear Information System (INIS)

    Cunha, S.H.F. da; Pires, S.H.; Rovere, E.L. La; Pereira, M.V.F.

    1993-01-01

    This paper presents the many stages of a new methodology propose to selection of alternatives of waterfall division of hydro graphical basin considering environmental impacts. The methodology uses the techniques of hierarchical analysis in evaluation of environmental impacts, simulation the individualized power plants in energy evaluation and multi-objective analysis in selection of better alternative of division of basin waterfall. The methodology still foresee moments and mechanisms to take into account the opinion of different social sectors. (C.M.)

  16. Is skewed income distribution good for environmental quality? A comparative analysis among selected BRICS countries.

    Science.gov (United States)

    Mahalik, Mantu Kumar; Mallick, Hrushikesh; Padhan, Hemachandra; Sahoo, Bhagaban

    2018-06-03

    A large number of studies have examined the linkage between income inequality and environmental quality at the individual country levels. This study attempts to examine the linkage between the two factors for the individual BRICS economies from a comparative perspective, which is scarce in the literature. It examines the selected countries (Brazil, India, China and South Africa) by endogenising the patterns of primary energy consumption (coal use and petroleum use), total primary energy consumption, economic growth, and urbanisation as key determining factors in CO 2 emission function. The long-run results based on ARDL bounds testing revealed that income inequality leads to increase in CO 2 emissions for Brazil, India and China, while the same factor leads to reduction in CO 2 emissions for South Africa. However, it observes that while coal use increases CO 2 emissions for India, China and South Africa, it has no effect for Brazil. In contrast, the use of petroleum products contributes to CO 2 emissions in Brazil, while the use of the same surprisingly results in reduction of carbon emissions in South Africa, India and China. The findings suggest that given the significance of income inequality in environmental pollution, the policy makers in these emerging economies have to take into consideration the role of income inequality, while designing the energy policy to achieve environmental sustainability.

  17. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 12. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The 664 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the twelfth in a series of reports prepared annually for the US Department of Energy Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy Remedial Action Programs. Major sections are (1) Decontamination and Decommissioning Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and key word. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects, analyzes, and disseminates information on environmental restoration and remedial actions. RAPIC staff and resources are available to meet a variety of information needs. Contact the center at FTS 624-7764 or (615) 574-7764.

  18. Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction.

    Science.gov (United States)

    Yin, Jun; Xu, Haokui; Duan, Jipeng; Shen, Mowei

    2018-05-01

    Traditionally, objects of attention are characterized either as full-fledged entities or either as elements grouped by Gestalt principles. Because humans appear to use social groups as units to explain social activities, we proposed that a socially defined group, according to social interaction information, would also be a possible object of attentional selection. This hypothesis was examined using displays with and without handshaking interactions. Results demonstrated that object-based attention, which was measured by an object-specific attentional advantage (i.e., shorter response times to targets on a single object), was extended to two hands performing a handshake but not to hands that did not perform meaningful social interactions, even when they did perform handshake-like actions. This finding cannot be attributed to the familiarity of the frequent co-occurrence of two handshaking hands. Hence, object-based attention can select a grouped object whose parts are connected within a meaningful social interaction. This finding implies that object-based attention is constrained by top-down information.

  19. Heuristics and Criterion Setting during Selective Encoding in Visual Decision-Making: Evidence from Eye Movements.

    Science.gov (United States)

    Schotter, Elizabeth R; Gerety, Cainen; Rayner, Keith

    2012-01-01

    When making a decision, people spend longer looking at the option they ultimately choose compared other options-termed the gaze bias effect-even during their first encounter with the options (Glaholt & Reingold, 2009a, 2009b; Schotter, Berry, McKenzie & Rayner, 2010). Schotter et al. (2010) suggested that this is because people selectively encode decision-relevant information about the options, on-line during the first encounter with them. To extend their findings and test this claim, we recorded subjects' eye movements as they made judgments about pairs of images (i.e., which one was taken more recently or which one was taken longer ago). We manipulated whether both images were presented in the same color content (e.g., both in color or both in black-and-white) or whether they differed in color content and the extent to which color content was a reliable cue to relative recentness of the images. We found that the magnitude of the gaze bias effect decreased when the color content cue was not reliable during the first encounter with the images, but no modulation of the gaze bias effect in remaining time on the trial. These data suggest people do selectively encode decision-relevant information on-line.

  20. Selection of bi-level image compression method for reduction of communication energy in wireless visual sensor networks

    Science.gov (United States)

    Khursheed, Khursheed; Imran, Muhammad; Ahmad, Naeem; O'Nils, Mattias

    2012-06-01

    Wireless Visual Sensor Network (WVSN) is an emerging field which combines image sensor, on board computation unit, communication component and energy source. Compared to the traditional wireless sensor network, which operates on one dimensional data, such as temperature, pressure values etc., WVSN operates on two dimensional data (images) which requires higher processing power and communication bandwidth. Normally, WVSNs are deployed in areas where installation of wired solutions is not feasible. The energy budget in these networks is limited to the batteries, because of the wireless nature of the application. Due to the limited availability of energy, the processing at Visual Sensor Nodes (VSN) and communication from VSN to server should consume as low energy as possible. Transmission of raw images wirelessly consumes a lot of energy and requires higher communication bandwidth. Data compression methods reduce data efficiently and hence will be effective in reducing communication cost in WVSN. In this paper, we have compared the compression efficiency and complexity of six well known bi-level image compression methods. The focus is to determine the compression algorithms which can efficiently compress bi-level images and their computational complexity is suitable for computational platform used in WVSNs. These results can be used as a road map for selection of compression methods for different sets of constraints in WVSN.

  1. Visual working memory modulates low-level saccade target selection: Evidence from rapidly generated saccades in the global effect paradigm

    Science.gov (United States)

    Hollingworth, Andrew; Matsukura, Michi; Luck, Steven J.

    2013-01-01

    In three experiments, we examined the influence of visual working memory (VWM) on the metrics of saccade landing position in a global effect paradigm. Participants executed a saccade to the more eccentric object in an object pair appearing on the horizontal midline, to the left or right of central fixation. While completing the saccade task, participants maintained a color in VWM for an unrelated memory task. Either the color of the saccade target matched the memory color (target match), the color of the distractor matched the memory color (distractor match), or the colors of neither object matched the memory color (no match). In the no-match condition, saccades tended to land at the midpoint between the two objects: the global, or averaging, effect. However, when one of the two objects matched VWM, the distribution of landing position shifted toward the matching object, both for target match and for distractor match. VWM modulation of landing position was observed even for the fastest quartile of saccades, with a mean latency as low as 112 ms. Effects of VWM on such rapidly generated saccades, with latencies in the express-saccade range, indicate that VWM interacts with the initial sweep of visual sensory processing, modulating perceptual input to oculomotor systems and thereby biasing oculomotor selection. As a result, differences in memory match produce effects on landing position similar to the effects generated by differences in physical salience. PMID:24190909

  2. Top-down inputs enhance orientation selectivity in neurons of the primary visual cortex during perceptual learning.

    Directory of Open Access Journals (Sweden)

    Samat Moldakarimov

    2014-08-01

    Full Text Available Perceptual learning has been used to probe the mechanisms of cortical plasticity in the adult brain. Feedback projections are ubiquitous in the cortex, but little is known about their role in cortical plasticity. Here we explore the hypothesis that learning visual orientation discrimination involves learning-dependent plasticity of top-down feedback inputs from higher cortical areas, serving a different function from plasticity due to changes in recurrent connections within a cortical area. In a Hodgkin-Huxley-based spiking neural network model of visual cortex, we show that modulation of feedback inputs to V1 from higher cortical areas results in shunting inhibition in V1 neurons, which changes the response properties of V1 neurons. The orientation selectivity of V1 neurons is enhanced without changing orientation preference, preserving the topographic organizations in V1. These results provide new insights to the mechanisms of plasticity in the adult brain, reconciling apparently inconsistent experiments and providing a new hypothesis for a functional role of the feedback connections.

  3. Visual working memory modulates low-level saccade target selection: evidence from rapidly generated saccades in the global effect paradigm.

    Science.gov (United States)

    Hollingworth, Andrew; Matsukura, Michi; Luck, Steven J

    2013-11-04

    In three experiments, we examined the influence of visual working memory (VWM) on the metrics of saccade landing position in a global effect paradigm. Participants executed a saccade to the more eccentric object in an object pair appearing on the horizontal midline, to the left or right of central fixation. While completing the saccade task, participants maintained a color in VWM for an unrelated memory task. Either the color of the saccade target matched the memory color (target match), the color of the distractor matched the memory color (distractor match), or the colors of neither object matched the memory color (no match). In the no-match condition, saccades tended to land at the midpoint between the two objects: the global, or averaging, effect. However, when one of the two objects matched VWM, the distribution of landing position shifted toward the matching object, both for target match and for distractor match. VWM modulation of landing position was observed even for the fastest quartile of saccades, with a mean latency as low as 112 ms. Effects of VWM on such rapidly generated saccades, with latencies in the express-saccade range, indicate that VWM interacts with the initial sweep of visual sensory processing, modulating perceptual input to oculomotor systems and thereby biasing oculomotor selection. As a result, differences in memory match produce effects on landing position similar to the effects generated by differences in physical salience.

  4. Multimodal Code-pairing and Switching of Visual-verbal Texts in Selected Nigerian Stand-up Comedy Performances

    Directory of Open Access Journals (Sweden)

    Mufutau Temitayo Lamidi

    2017-10-01

    Full Text Available This study examines multimodal pairing and switching of codes as features of visual-verbal texts and how they are used as strategies for evoking humour in Nigerian stand-up comedy performances, an area that has not attracted much scholarly attention. Data were obtained through purposive random sampling and analysed through content analysis. Six DVDs (Vols. 3, 7, 8 & 28 of Nite of a Thousand Laughs; Vols. 27 & 28 of AY LIVE Happiness Edition and 6 video clips (downloaded from the Internet all totalling 8 hours and 20 minutes of play were selected for the study. Incongruity, Layered Meaning and Visual Semiotics serve as theoretical framework. The study identifies different multimodal strategies such as code-pairing and integration in different forms of oral codes, gestures, costume, and symbols; intertextuality; incongruous translations/ deliberate misinterpretations; and mimicry, quotes and paralanguage used to elicit laughter. It suggests that these features are also useful in other speech-making events, and concludes that the integration of codes and modes of communication serves as an effective strategy in evoking humour and laughter in stand-up comedy

  5. Transfrontier problems in connection with the site selection of power stations and energy facilities with environmental impact

    International Nuclear Information System (INIS)

    Manz, P.; Kanton Basel-Landschaft, Liestal

    1977-01-01

    This contribution deals with the subjects politics and environmental protection, site selection procedures and their consequences, and tasks of international commissions, and concludes that cooperation, research and agreement are essential for environmental and energy policies which are to be beneficial to all. (RW) [de

  6. Oscillatory Mechanisms of Stimulus Processing and Selection in the Visual and Auditory Systems: State-of-the-Art, Speculations and Suggestions

    Directory of Open Access Journals (Sweden)

    Benedikt Zoefel

    2017-05-01

    Full Text Available All sensory systems need to continuously prioritize and select incoming stimuli in order to avoid overflow or interference, and provide a structure to the brain's input. However, the characteristics of this input differ across sensory systems; therefore, and as a direct consequence, each sensory system might have developed specialized strategies to cope with the continuous stream of incoming information. Neural oscillations are intimately connected with this selection process, as they can be used by the brain to rhythmically amplify or attenuate input and therefore represent an optimal tool for stimulus selection. In this paper, we focus on oscillatory processes for stimulus selection in the visual and auditory systems. We point out both commonalities and differences between the two systems and develop several hypotheses, inspired by recently published findings: (1 The rhythmic component in its input is crucial for the auditory, but not for the visual system. The alignment between oscillatory phase and rhythmic input (phase entrainment is therefore an integral part of stimulus selection in the auditory system whereas the visual system merely adjusts its phase to upcoming events, without the need for any rhythmic component. (2 When input is unpredictable, the visual system can maintain its oscillatory sampling, whereas the auditory system switches to a different, potentially internally oriented, “mode” of processing that might be characterized by alpha oscillations. (3 Visual alpha can be divided into a faster occipital alpha (10 Hz and a slower frontal alpha (7 Hz that critically depends on attention.

  7. Mean field theory for a balanced hypercolumn model of orientation selectivity in primary visual cortex

    CERN Document Server

    Lerchner, A; Hertz, J; Ahmadi, M

    2004-01-01

    We present a complete mean field theory for a balanced state of a simple model of an orientation hypercolumn. The theory is complemented by a description of a numerical procedure for solving the mean-field equations quantitatively. With our treatment, we can determine self-consistently both the firing rates and the firing correlations, without being restricted to specific neuron models. Here, we solve the analytically derived mean-field equations numerically for integrate-and-fire neurons. Several known key properties of orientation selective cortical neurons emerge naturally from the description: Irregular firing with statistics close to -- but not restricted to -- Poisson statistics; an almost linear gain function (firing frequency as a function of stimulus contrast) of the neurons within the network; and a contrast-invariant tuning width of the neuronal firing. We find that the irregularity in firing depends sensitively on synaptic strengths. If Fano factors are bigger than 1, then they are so for all stim...

  8. Attention and perceptual implicit memory: effects of selective versus divided attention and number of visual objects.

    Science.gov (United States)

    Mulligan, Neil W

    2002-08-01

    Extant research presents conflicting results on whether manipulations of attention during encoding affect perceptual priming. Two suggested mediating factors are type of manipulation (selective vs divided) and whether attention is manipulated across multiple objects or within a single object. Words printed in different colors (Experiment 1) or flanked by colored blocks (Experiment 2) were presented at encoding. In the full-attention condition, participants always read the word, in the unattended condition they always identified the color, and in the divided-attention conditions, participants attended to both word identity and color. Perceptual priming was assessed with perceptual identification and explicit memory with recognition. Relative to the full-attention condition, attending to color always reduced priming. Dividing attention between word identity and color, however, only disrupted priming when these attributes were presented as multiple objects (Experiment 2) but not when they were dimensions of a common object (Experiment 1). On the explicit test, manipulations of attention always affected recognition accuracy.

  9. Ad-hoc and context-dependent adjustments of selective attention in conflict control: an ERP study with visual probes.

    Science.gov (United States)

    Nigbur, R; Schneider, J; Sommer, W; Dimigen, O; Stürmer, B

    2015-02-15

    Cognitive conflict control in flanker tasks has often been described using the zoom-lens metaphor of selective attention. However, whether and how selective attention - in terms of suppression and enhancement - operates in this context has remained unclear. To examine the dynamic interplay of selective attention and cognitive control we used electrophysiological measures and presented task-irrelevant visual probe stimuli at foveal, parafoveal, and peripheral display positions. Target-flanker congruency varied either randomly from trial to trial (mixed-block) or block-wise (fixed-block) in order to induce reactive versus proactive control modes, respectively. Three EEG measures were used to capture ad-hoc adjustments within trials as well as effects of context-based predictions: the N1 component of the visual evoked potential (VEP) to probes, the VEP to targets, and the conflict-related midfrontal N2 component. Results from probe-VEPs indicate that enhanced processing of the foveal target rather than suppression of the peripheral flankers supports interference control. In incongruent mixed-block trials VEPs were larger to probes near the targets. In the fixed-blocks probe-VEPs were not modulated, but contrary to the mixed-block the preceding target-related VEP was affected by congruency. Results of the control-related N2 reveal largest amplitudes in the unpredictable context, which did not differentiate for stimulus and response incongruency. In contrast, in the predictable context, N2 amplitudes were reduced overall and differentiated between stimulus and response incongruency. Taken together these results imply that predictability alters interference control by a reconfiguration of stimulus processing. During unpredictable sequences participants adjust their attentional focus dynamically on a trial-by-trial basis as reflected in congruency-dependent probe-VEP-modulation. This reactive control mode also elicits larger N2 amplitudes. In contrast, when task demands

  10. Bottlenecks in bog pine multiplication by somatic embryogenesis and their visualization with the environmental scanning electron microscope.

    Science.gov (United States)

    Vlašínová, Helena; Neděla, Vilem; Đorđević, Biljana; Havel, Ladislav

    2017-07-01

    Somatic embryogenesis (SE) is an important biotechnological technique used for the propagation of many pine species in vitro. However, in bog pine, one of the most endangered tree species in the Czech Republic, limitations were observed, which negatively influenced the development and further germination of somatic embryos. Although initiation frequency was very low-0.95 %, all obtained cell lines were subjected to maturation. The best responding cell line (BC1) was used and subjected to six different variants of the maturation media. The media on which the highest number of early-precotyledonary/cotyledonary somatic embryos was formed was supplemented with 121 μM abscisic acid (ABA) and with 6 % maltose. In the end of maturation experiments, different abnormalities in formation of somatic embryos were observed. For visualization and identification of abnormalities in meristem development during proliferation and maturation processes, the environmental scanning electron microscope was used. In comparison to the classical light microscope, the non-commercial environmental scanning electron microscope AQUASEM II has been found as a very useful tool for the quick recognition of apical meristem disruption and abnormal development. To our knowledge, this is the first report discussing somatic embryogenesis in bog pine. Based on this observation, the cultivation procedure could be enhanced and the method for SE of bog pine optimized.

  11. Mining environmental high-throughput sequence data sets to identify divergent amplicon clusters for phylogenetic reconstruction and morphotype visualization.

    Science.gov (United States)

    Gimmler, Anna; Stoeck, Thorsten

    2015-08-01

    Environmental high-throughput sequencing (envHTS) is a very powerful tool, which in protistan ecology is predominantly used for the exploration of diversity and its geographic and local patterns. We here used a pyrosequenced V4-SSU rDNA data set from a solar saltern pond as test case to exploit such massive protistan amplicon data sets beyond this descriptive purpose. Therefore, we combined a Swarm-based blastn network including 11 579 ciliate V4 amplicons to identify divergent amplicon clusters with targeted polymerase chain reaction (PCR) primer design for full-length small subunit of the ribosomal DNA retrieval and probe design for fluorescence in situ hybridization (FISH). This powerful strategy allows to benefit from envHTS data sets to (i) reveal the phylogenetic position of the taxon behind divergent amplicons; (ii) improve phylogenetic resolution and evolutionary history of specific taxon groups; (iii) solidly assess an amplicons (species') degree of similarity to its closest described relative; (iv) visualize the morphotype behind a divergent amplicons cluster; (v) rapidly FISH screen many environmental samples for geographic/habitat distribution and abundances of the respective organism and (vi) to monitor the success of enrichment strategies in live samples for cultivation and isolation of the respective organisms. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Draft Environmental Impact Statement. MX Deployment Area Selection and Land Withdrawal/Acquisition DEIS. Volume IV. Part II. Environmental Consequences to the Study Regions and Operating Base Vicinities.

    Science.gov (United States)

    1980-12-01

    Subtitle) 5. TYPE OF REPORT & PERIOD COVERED Draft Environmental Impact Statement-MX Draft-December 80 Deployment Alea Selection-Environmental...recreation, a weekend at the lake, the opportunity to be alone with yourself and your family, the clean air to see the next mountain and the freedom to...traffic volumes and projected traffic volumes during the peak construction year. In mountain passes, where capacity is severely reduced by steep grades

  13. Environmental mobile robot based on artificial intelligence and visual perception for weed elimination

    Directory of Open Access Journals (Sweden)

    Nabeel Kadim Abid AL-SAHIB

    2012-12-01

    Full Text Available This research presents a new editing design for the pioneer p3-dx mobile robot by adding a mechanical gripper for eliminating the weed and a digital camera for capturing the image of the field. Also, a wireless kit that makes control on the motor's gripper is envisaged. This work consists of two parts. The theoretical part contains a program to read the image and discover the weed coordinates which will be sent to the path planning software to discover the locations of weed, green plant and sick plant. These positions are sent then to the mobile robot navigation software. Then the wireless signal is sent to the gripper. The experimental part is represented as a digital camera that takes an image of the agricultural field, and then sends it to the computer for processing. After that the weeds coordinates are sent to the mobile robots by mobile robot navigation software. Next, the wireless signal is sent to the wireless kit controlling the motor gripper by the computer interface program; the first trial on the agricultural field shows that the mobile robot can discriminate the green plant, from weed and sick plant and can take the right decision with respect to treatment or elimination. The experimental work shows that the environmental mobile robot can detect successfully the weed, sick plant and the hale plant. The mobile robot also travels from base to the target point represented by the weed and sick plants in the optimum path. The experimental work also shows that the environmental mobile robot can eliminate the weed and cure the sick plants in a correctly way.

  14. Functional Imaging of Audio-Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Rinne, Teemu; Muers, Ross S; Salo, Emma; Slater, Heather; Petkov, Christopher I

    2017-06-01

    The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio-visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio-visual selective attention modulates the primate brain, identify sources for "lost" attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. © The Author 2017. Published by Oxford University Press.

  15. Functional Imaging of Audio–Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Muers, Ross S.; Salo, Emma; Slater, Heather; Petkov, Christopher I.

    2017-01-01

    Abstract The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio–visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio–visual selective attention modulates the primate brain, identify sources for “lost” attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. PMID:28419201

  16. Do episodic migraineurs selectively attend to headache-related visual stimuli?

    Science.gov (United States)

    McDermott, Michael J; Peck, Kelly R; Walters, A Brooke; Smitherman, Todd A

    2013-02-01

    To assess pain-related attentional biases among individuals with episodic migraine. Prior studies have examined whether chronic pain patients selectively attend to pain-related stimuli in the environment, but these studies have produced largely mixed findings and focused primarily on patients with chronic musculoskeletal pain. Limited research has implicated attentional biases among chronic headache patients, but no studies have been conducted among episodic migraineurs, who comprise the overwhelming majority of the migraine population. This was a case-control, experimental study. Three hundred and eight participants (mean age = 19.2 years [standard deviation = 3.3]; 69.5% female; 36.4% minority), consisting of 84 episodic migraineurs, diagnosed in accordance with International Classification of Headache Disorders (2(nd) edition) criteria using a structured diagnostic interview, and 224 non-migraine controls completed a computerized dot probe task to assess attentional bias toward headache-related pictorial stimuli. The task consisted of 192 trials and utilized 2 emotional-neutral stimulus pairing conditions (headache-neutral and happy-neutral). No within-group differences for reaction time latencies to headache vs happy conditions were found among those with episodic migraine or among the non-migraine controls. Migraine status was unrelated to attentional bias indices for both headache (F [1,306] = 0.56, P = .45) and happy facial stimuli (F [1,306] = 0.37, P = .54), indicating a lack of between-group differences. Lack of within- and between-group differences was confirmed with repeated measures analysis of variance. In light of the large sample size and prior pilot testing of presented images, results suggest that episodic migraineurs do not differentially attend to headache-related facial stimuli. Given modest evidence of attentional biases among chronic headache samples, these findings suggest potential differences in attentional

  17. Visual selective attention biases contribute to the other-race effect among 9-month-old infants.

    Science.gov (United States)

    Markant, Julie; Oakes, Lisa M; Amso, Dima

    2016-04-01

    During the first year of life, infants maintain their ability to discriminate faces from their own race but become less able to differentiate other-race faces. Though this is likely due to daily experience with own-race faces, the mechanisms linking repeated exposure to optimal face processing remain unclear. One possibility is that frequent experience with own-race faces generates a selective attention bias to these faces. Selective attention elicits enhancement of attended information and suppression of distraction to improve visual processing of attended objects. Thus attention biases to own-race faces may boost processing and discrimination of these faces relative to other-race faces. We used a spatial cueing task to bias attention to own- or other-race faces among Caucasian 9-month-old infants. Infants discriminated faces in the focus of the attention bias, regardless of race, indicating that infants remained sensitive to differences among other-race faces. Instead, efficacy of face discrimination reflected the extent of attention engagement. © 2015 Wiley Periodicals, Inc.

  18. Use of strategic environmental assessment in the site selection process for a radioactive waste disposal facility in Slovenia.

    Science.gov (United States)

    Dermol, Urška; Kontić, Branko

    2011-01-01

    The benefits of strategic environmental considerations in the process of siting a repository for low- and intermediate-level radioactive waste (LILW) are presented. The benefits have been explored by analyzing differences between the two site selection processes. One is a so-called official site selection process, which is implemented by the Agency for radwaste management (ARAO); the other is an optimization process suggested by experts working in the area of environmental impact assessment (EIA) and land-use (spatial) planning. The criteria on which the comparison of the results of the two site selection processes has been based are spatial organization, environmental impact, safety in terms of potential exposure of the population to radioactivity released from the repository, and feasibility of the repository from the technical, financial/economic and social point of view (the latter relates to consent by the local community for siting the repository). The site selection processes have been compared with the support of the decision expert system named DEX. The results of the comparison indicate that the sites selected by ARAO meet fewer suitability criteria than those identified by applying strategic environmental considerations in the framework of the optimization process. This result stands when taking into account spatial, environmental, safety and technical feasibility points of view. Acceptability of a site by a local community could not have been tested, since the formal site selection process has not yet been concluded; this remains as an uncertain and open point of the comparison. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Stereoscopic CAD and Environmental Sculpture: Enhancement of the Design Process in the Visual Arts

    Science.gov (United States)

    Fisher, Robert N.; Bandini, Pier L.

    1989-09-01

    In this paper, co-authors Robert Fisher and Pier Luigi Bandini describe their personal observations concerning stereo enhancements of computer graphics images employed in their research. in Part One, Robert Fisher, a professional sculptor, Professor and Artist-in-Residence in the College of Engineering at Penn State, cites three recent environmental sculpture projects: "See-scape," "A Page from the Book of Skies," and an as yet untitled work. Wireframe images, interior views of architectural spaces, and complex imagery are rendered comprehensible by stereo 3-D. In Part Two, Pier L. Bandini, Associate Professor of Architecture and Director of the Architecture CAD Lab at Penn State, describes the virtues of the stereo-enhanced wireframe model--the benefits of the "see-through coupled with a complete awareness of the whole space." The final example, of a never-realized XVIII-century project, suggests a new and profound application of stereo 3-D to historical inquiry, namely, the experience of ancient spaces and structures that are no longer existing or that were never constructed.

  20. Environmental cost-effectiveness analysis in intertemporal natural resource policy: evaluation of selective fishing gear.

    Science.gov (United States)

    Kronbak, Lone Grønbæk; Vestergaard, Niels

    2013-12-15

    In most decision-making involving natural resources, the achievements of a given policy (e.g., improved ecosystem or biodiversity) are rather difficult to measure in monetary units. To address this problem, the current paper develops an environmental cost-effectiveness analysis (ECEA) to include intangible benefits in intertemporal natural resource problems. This approach can assist managers in prioritizing management actions as least cost solutions to achieve quantitative policy targets. The ECEA framework is applied to a selective gear policy case in Danish mixed trawl fisheries in Kattegat and Skagerrak. The empirical analysis demonstrates how a policy with large negative net benefits might be justified if the intangible benefits are included. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. HIGH QUALITY ENVIRONMENTAL PRINCIPLES APPLIED TO THE ARCHITECTONIC DESIGN SELECTION PROCEDURE: THE NUTRE LAB CASE

    Directory of Open Access Journals (Sweden)

    Claudia Barroso Krause

    2012-06-01

    Full Text Available The need to produce more sustainable buildings has been influencing the design decisions all over the world. That’s why it is imperative, in Brazil, the development of strategies and method to aid the decision making during the design process, focused on high quality environmental. This paper presents a decision support tool based on the principles of sustainable construction developed by the Project, Architecture and Sustainability Research Group (GPAS of Federal University of Rio de Janeiro – Brazil. The methodology has been developed for the selection of a preliminary design of a laboratory to be built at Rio Technology Park at the University campus. The support provided by GPAS occurred in three stages: the elaboration of the Reference Guide for the competitors, the development of a methodology to evaluate the proposed solutions (based on environmental performance criteria and the assistance of the members of jury in the trial phase. The theoretical framework was based upon the concepts of the bioclimatic architecture, the procedures specified by the certification HQE® (Haute Qualité Environnementale and the method suggested by the ADDENDA® architecture office. The success of this experience points out the possibility to future application in similar cases.

  2. Environmentally Benign, Rapid, and Selective Extraction of Gold from Ores and Waste Electronic Materials.

    Science.gov (United States)

    Yue, Chunlin; Sun, Huaming; Liu, Wen-Jing; Guan, Binbin; Deng, Xudong; Zhang, Xu; Yang, Peng

    2017-08-01

    The extraction of gold from ores and electronic waste is an important topic worldwide, as this precious metal has immense value in a variety of fields. However, serious environmental pollution and high energy consumption due to the use of toxic oxidation reagents and harsh reaction conditions is a well-known problem in the gold industry. Herein, we report a new chemical method based on the combined use of N-bromosuccinimide (NBS) and pyridine (Py), which has a greatly decreased environmental impact and reagent cost, as well as mild reaction requirements. This method can directly leach Au 0 from gold ore and electronic waste to form Au III in water. The process is achieved in a yield of approximately 90 % at room temperature and a nearly neutral pH. The minimum dose of NBS/Py is as low as 10 mm, which exhibits low toxicity towards mammalian cells and animals as well as aquatic creatures. The high leaching selectivity of Au over other metals during gold leaching is demonstrated, showing that this method has great potential for practical industrial application towards the sustainable refining of gold from ores and electronic waste. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Selected dark sides of biomass-derived biochars as environmental amendments

    Institute of Scientific and Technical Information of China (English)

    Zien Chen; Lei Luo; Diyi Xiao; Jitao Lv; Bei Wen; Yibing Ma; Shuzhen Zhang

    2017-01-01

    With the rapid increase in the application of biochars as amendments,studies are needed to clarify the possible environmental risks derived from biochars to use safely the biomass resources.This work reported selected dark sides of maize straw-and swine manurederived biochars pyrolyzed at 300 and 500℃C.During the pyrolysis processes,total heavy metals in the biochars were enriched greatly accompanying with considerable emission of the heavy metals into atmosphere and the trends became increasingly obvious with pyrolysis temperature.Meanwhile,the biochars showed distinctly decreased available heavy metals compared with raw feedstocks,which could be mainly attributed to the sorption by the inorganics in the biochars.The water-and acid-washing treatments significantly increased the releasing risks of heavy metals from biochars into the environments.Electron paramagnetic resonance analysis indicated that persistent free radicals,emerged strongly in the biochars as a function of the aromatization of biomass feedstocks,were free from the influence of water-,acid-,or organic-washing of the biochars and could remain stable even after aged in soils for 30 days.Dissolved biochars,highly produced during pyrolysis processes,showed distinct properties including lower molecular weight distribution while higher aromaticity compared with soil dissolved organic carbon.The results of this study provide important perspectives on the safe usage of biochars as agricultural/environmental amendments.

  4. The impact of selected environmental, behavioral and psychosocial factors on schoolchildren's somatic and mental health.

    Science.gov (United States)

    Vondrova, Diana; Kapsdorfer, Daniela; Argalasova, Lubica; Hirosova, Katarina; Samohyl, Martin; Sevcikova, Ludmila

    2017-03-01

    Children develop rapidly and many exogenous determinants of health significantly affect their somatic and mental development. There is a subjective perception of cognitive load associated with the educational process. The aim of the study is to assess individual environmental, behavioral and psychosocial factors influencing physical health and to investigate the amount of mental load in children. We investigated 87 schoolchildren (47 girls and 40 boys) aged 10-12 years, who were attending primary school in Bratislava. To assess values of selected factors we used a questionnaire form and personality characteristics were estimated by standardized psycho-diagnostic and IQ tests [range of classic fear, social-situation anxiety and jitters [skala Klasickeho strachu a Socialno-situacnej (in Slovak)] (KSAT), Eyesenck Personality Questionnaire for children (EPQ), Raven's IQ test]. Self-reported perception of mental load was assessed by questionnaire of subjective feelings and states (SFS). Children's body parameters were assessed using anthropometric measurements [height, weight, chest, abdominal and hip girth, Rohrer's index (RI), body mass index (BMI)] and a body fat measurement method (skinfold thickness). The results confirmed a significant relationship between higher parameters of overweight and obesity and irregular breakfast eating (pmental effort and cognitive load associated with the educational process. We note a close relationship between the higher mental load and the score of neuroticism (pmental health of schoolchildren is significantly affected by exogenous factors. Therefore, in terms of protection and promotion of children's health, it is important to evaluate and monitor environmental risk factors and to form their healthy habits.

  5. Review Article : Utilization of Environmental Radiochemistry Techniques for Selection and Evaluation of Nuclear Facility Sites

    International Nuclear Information System (INIS)

    Atta, E.R.; Madbouly, A.M.; Zakaria, Kh.M.

    2016-01-01

    This research review puts necessary considerations on the available environmental radiochemistry techniques for selection and evaluation of a nuclear facility sites.The main bjective in site evaluation for nuclear facilities in terms of nuclear safety is to protect the site workers, the public and the environment from the effects of ionizing radiation release from nuclear facilities due to accidents. The extreme sensitivity and speed of radiochemical methods make their applications of considerable importance in several fields and they have found many uses. Information about the existed radioactivity in the different nuclear facilities is an essential requirement for their environmental assessment. It is necessary to estimate the various radioactivity levels in the environment through qualitative and quantitative analytical techniques and to assess the potential effects of the nuclear facility in the region by considering the characteristics of sites.The siting and site evaluation requirements are discussed. Emphasis was given to types of radiochemical techniques used for characterization of the site parameters which determine the potential hazards of the site on the facility and the facility on the site. Emphasis has been also given to the quantitative and qualitative analysis of naturally occurring radionuclides for monitoring and control .There are some techniques employed such as radioactive tracer technique, liquid scintillation technique, gamma spectrometry technique, neutron activation analysis technique, fluorimetric technique and isotope hydrology technique.

  6. The healthy building intervention study: Objectives, methods and results of selected environmental measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, W.J.; Faulkner, D.; Sullivan, D. [and others

    1998-02-17

    To test proposed methods for reducing SBS symptoms and to learn about the causes of these symptoms, a double-blind controlled intervention study was designed and implemented. This study utilized two different interventions designed to reduce occupants` exposures to airborne particles: (1) high efficiency filters in the building`s HVAC systems; and (2) thorough cleaning of carpeted floors and fabric-covered chairs with an unusually powerful vacuum cleaner. The study population was the workers on the second and fourth floors of a large office building with mechanical ventilation, air conditioning, and sealed windows. Interventions were implemented on one floor while the occupants on the other floor served as a control group. For the enhanced-filtration intervention, a multiple crossover design was used (a crossover is a repeat of the experiment with the former experimental group as the control group and vice versa). Demographic and health symptom data were collected via an initial questionnaire on the first study week and health symptom data were obtained each week, for eight additional weeks, via weekly questionnaires. A large number of indoor environmental parameters were measured during the study including air temperatures and humidities, carbon dioxide concentrations, particle concentrations, concentrations of several airborne bioaerosols, and concentrations of several microbiologic compounds within the dust sampled from floors and chairs. This report describes the study methods and summarizes the results of selected environmental measurements.

  7. Region-specificity of GABAA receptor mediated effects on orientation and direction selectivity in cat visual cortical area 18.

    Science.gov (United States)

    Jirmann, Kay-Uwe; Pernberg, Joachim; Eysel, Ulf T

    2009-01-01

    The role of GABAergic inhibition in orientation and direction selectivity has been investigated with the GABA(A)-Blocker bicuculline in the cat visual cortex, and results indicated a region specific difference of functional contributions of GABAergic inhibition in areas 17 and 18. In area 17 inhibition appeared mainly involved in sculpturing orientation and direction tuning, while in area 18 inhibition seemed more closely associated with temporal receptive field properties. However, different types of stimuli were used to test areas 17 and 18 and further studies performed in area 17 suggested an important influence of the stimulus type (single light bars vs. moving gratings) on the evoked responses (transient vs. sustained) and inhibitory mechanisms (GABA(A) vs. GABA(B)) which in turn might be more decisive for the specific results than the cortical region. To insert the missing link in this chain of arguments it was necessary to study GABAergic inhibition in area 18 with moving light bars, which has not been done so far. Therefore, in the present study we investigated area 18 cells responding to oriented moving light bars with extracellular recordings and reversible microiontophoretic blockade of GABAergig inhibition with bicuculline methiodide. The majority of neurons was characterized by a pronounced orientation specificity and variable degrees of direction selectivity. GABA(A)ergic inhibition significantly influenced preferred orientation and preferred direction in area 18. During the action of bicuculline orientation tuning width increased and orientation and direction selectivity indices decreased. Our results obtained in area 18 with moving bar stimuli, although in the proportion of affected cells similar to those described in area 17, quantitatively matched the findings for direction and orientation specificity obtained with moving gratings in area 18. Accordingly, stimulus type is not decisive in area 18 and the GABA(A) dependent, inhibitory intracortical

  8. Functional visual sensitivity to ultraviolet wavelengths in the Pileated Woodpecker (Dryocopus pileatus), and its influence on foraging substrate selection

    Science.gov (United States)

    O'Daniels, Sean T.; Kesler, Dylan C.; Mihail, Jeanne D.; Webb, Elisabeth B.; Werner, Scott J.

    2017-01-01

    Most diurnal birds are presumed visually sensitive to near ultraviolet (UV) wavelengths, however, controlled behavioral studies investigating UV sensitivity remain few. Although woodpeckers are important as primary cavity excavators and nuisance animals, published work on their visual systems is limited. We developed a novel foraging-based behavioral assay designed to test UV sensitivity in the Pileated Woodpecker (Dryocopus pileatus). We acclimated 21 wild-caught woodpeckers to foraging for frozen mealworms within 1.2 m sections of peeled cedar (Thuja spp.) poles. We then tested the functional significance of UV cues by placing frozen mealworms behind UV-reflective covers, UV-absorptive covers, or decayed red pine substrates within the same 1.2 m poles in independent experiments. Behavioral responses were greater toward both UV-reflective and UV-absorptive substrates in three experiments. Study subjects therefore reliably differentiated and attended to two distinct UV conditions of a foraging substrate. Cue-naïve subjects showed a preference for UV-absorptive substrates, suggesting that woodpeckers may be pre-disposed to foraging from such substrates. Behavioral responses were greater toward decayed pine substrates (UV-reflective) than sound pine substrates suggesting that decayed pine can be a useful foraging cue. The finding that cue-naïve subjects selected UV-absorbing foraging substrates has implications for ecological interactions of woodpeckers with fungi. Woodpeckers transport fungal spores, and communication methods analogous to those of plant-pollinator mutualisms (i.e. UV-absorbing patterns) may have evolved to support woodpecker-fungus mutualisms.

  9. Environmental settings for selected U.S. Department of Energy installations - support information for the Programmatic Environmental Impact Statement

    International Nuclear Information System (INIS)

    Holdren, G.R.; Glantz, C.S.; Berg, L.K.; Delinger, K.; Goodwin, S.M.; Rustad, J.R.; Schalla, R.; Schramke, J.A.

    1994-12-01

    This report contains the environmental setting information developed for 20 U.S. Department of Energy (DOE) installations in support of the DOE's Programmatic Environmental Impact Study (PEIS). The objective of the PEIS is to provide the public with information about the types of radiological and hazardous wastes and environmental contamination problems associated with major DOE facilities across the country, and to assess the relative risks that these wastes pose to the public, onsite workers, and the environment. Environmental setting information consists of the site-specific data required to model (using the Multimedia Environmental Pollutant Assessment System) the atmospheric, groundwater, and surface water transport of contaminants within and near the boundaries of the installations. The environmental settings data describes the climate, atmospheric dispersion, hydrogeology, and surface water characteristics of the installations. The number of discrete environmental settings established for each installation was governed by two competing requirements: (1) the risks posed by contaminants released from numerous waste sites were to be modeled as accurately as possible, and (2) the modeling required for numerous release sites and a large number of contaminants had to be completed within the limits imposed by the PEIS schedule. The final product is the result of attempts to balance these competing concerns in a way that minimizes the number of settings per installation in order to meet the project schedule while at the same time providing adequate, if sometimes highly simplified, representations of the different areas within an installation. Environmental settings were developed in conjunction with installation experts in the fields of meteorology, geology, hydrology, and geochemistry. When possible, local experts participated in the initial development, fine tuning, and final review of the PEIS environmental settings

  10. Reconfigurable Auditory-Visual Display

    Science.gov (United States)

    Begault, Durand R. (Inventor); Anderson, Mark R. (Inventor); McClain, Bryan (Inventor); Miller, Joel D. (Inventor)

    2008-01-01

    System and method for visual and audible communication between a central operator and N mobile communicators (N greater than or equal to 2), including an operator transceiver and interface, configured to receive and display, for the operator, visually perceptible and audibly perceptible signals from each of the mobile communicators. The interface (1) presents an audible signal from each communicator as if the audible signal is received from a different location relative to the operator and (2) allows the operator to select, to assign priority to, and to display, the visual signals and the audible signals received from a specified communicator. Each communicator has an associated signal transmitter that is configured to transmit at least one of the visual signals and the audio signal associated with the communicator, where at least one of the signal transmitters includes at least one sensor that senses and transmits a sensor value representing a selected environmental or physiological parameter associated with the communicator.

  11. The relationship between visual working memory and attention: retention of precise colour information in the absence of effects on perceptual selection.

    Science.gov (United States)

    Hollingworth, Andrew; Hwang, Seongmin

    2013-10-19

    We examined the conditions under which a feature value in visual working memory (VWM) recruits visual attention to matching stimuli. Previous work has suggested that VWM supports two qualitatively different states of representation: an active state that interacts with perceptual selection and a passive (or accessory) state that does not. An alternative hypothesis is that VWM supports a single form of representation, with the precision of feature memory controlling whether or not the representation interacts with perceptual selection. The results of three experiments supported the dual-state hypothesis. We established conditions under which participants retained a relatively precise representation of a parcticular colour. If the colour was immediately task relevant, it reliably recruited attention to matching stimuli. However, if the colour was not immediately task relevant, it failed to interact with perceptual selection. Feature maintenance in VWM is not necessarily equivalent with feature-based attentional selection.

  12. Selective attention to spatial and non-spatial visual stimuli is affected differentially by age: Effects on event-related brain potentials and performance data

    NARCIS (Netherlands)

    Talsma, D.; Kok, Albert; Ridderinkhof, K. Richard

    2006-01-01

    To assess selective attention processes in young and old adults, behavioral and event-related potential (ERP) measures were recorded. Streams of visual stimuli were presented from left or right locations (Experiment 1) or from a central location and comprising two different spatial frequencies

  13. Working-memory capacity predicts the executive control of visual search among distractors: the influences of sustained and selective attention.

    Science.gov (United States)

    Poole, Bradley J; Kane, Michael J

    2009-07-01

    Variation in working-memory capacity (WMC) predicts individual differences in only some attention-control capabilities. Whereas higher WMC subjects outperform lower WMC subjects in tasks requiring the restraint of prepotent but inappropriate responses, and the constraint of attentional focus to target stimuli against distractors, they do not differ in prototypical visual-search tasks, even those that yield steep search slopes and engender top-down control. The present three experiments tested whether WMC, as measured by complex memory span tasks, would predict search latencies when the 1-8 target locations to be searched appeared alone, versus appearing among distractor locations to be ignored, with the latter requiring selective attentional focus. Subjects viewed target-location cues and then fixated on those locations over either long (1,500-1,550 ms) or short (300 ms) delays. Higher WMC subjects identified targets faster than did lower WMC subjects only in the presence of distractors and only over long fixation delays. WMC thus appears to affect subjects' ability to maintain a constrained attentional focus over time.

  14. Luminol functionalized gold nanoparticles as colorimetric and chemiluminescent probes for visual, label free, highly sensitive and selective detection of minocycline

    Science.gov (United States)

    He, Yi; Peng, Rufang

    2014-11-01

    In this work, luminol functionalized gold nanoparticles (LuAuNPs) were used as colorimetric and chemiluminescent probes for visual, label free, sensitive and selective detection of minocycline (MC). The LuAuNPs were prepared by simple one-pot reduction of HAuCl4 with luminol, which exhibited a good chemiluminescence (CL) activity owing to the presence of luminol molecules on their surface and surface plasmon resonance absorption. In the absence of MC, the color of LuAuNPs was wine red and their size was relatively small (˜25 nm), which could react with silver nitrate, producing a strong CL emission. Upon the addition of MC at acidic buffer solutions, the electrostatic interaction between positively charged MC and negatively charged LuAuNPs caused the aggregation of LuAuNPs, generating a purple or blue color. Simultaneously, the aggregated LuAuNPs did not effectively react with silver nitrate, producing a weak CL emission. The signal change was linearly dependent on the logarithm of MC concentration in the range from 30 ng to 1.0 μg for colorimetric detection and from 10 ng to 1.0 μg for CL detection. With colorimetry, a detection limit of 22 ng was achieved, while the detection limit for CL detection modality was 9.7 ng.

  15. Luminol functionalized gold nanoparticles as colorimetric and chemiluminescent probes for visual, label free, highly sensitive and selective detection of minocycline

    International Nuclear Information System (INIS)

    He, Yi; Peng, Rufang

    2014-01-01

    In this work, luminol functionalized gold nanoparticles (LuAuNPs) were used as colorimetric and chemiluminescent probes for visual, label free, sensitive and selective detection of minocycline (MC). The LuAuNPs were prepared by simple one-pot reduction of HAuCl 4 with luminol, which exhibited a good chemiluminescence (CL) activity owing to the presence of luminol molecules on their surface and surface plasmon resonance absorption. In the absence of MC, the color of LuAuNPs was wine red and their size was relatively small (∼25 nm), which could react with silver nitrate, producing a strong CL emission. Upon the addition of MC at acidic buffer solutions, the electrostatic interaction between positively charged MC and negatively charged LuAuNPs caused the aggregation of LuAuNPs, generating a purple or blue color. Simultaneously, the aggregated LuAuNPs did not effectively react with silver nitrate, producing a weak CL emission. The signal change was linearly dependent on the logarithm of MC concentration in the range from 30 ng to 1.0 μg for colorimetric detection and from 10 ng to 1.0 μg for CL detection. With colorimetry, a detection limit of 22 ng was achieved, while the detection limit for CL detection modality was 9.7 ng. (paper)

  16. A general procedure to generate models for urban environmental-noise pollution using feature selection and machine learning methods.

    Science.gov (United States)

    Torija, Antonio J; Ruiz, Diego P

    2015-02-01

    The prediction of environmental noise in urban environments requires the solution of a complex and non-linear problem, since there are complex relationships among the multitude of variables involved in the characterization and modelling of environmental noise and environmental-noise magnitudes. Moreover, the inclusion of the great spatial heterogeneity characteristic of urban environments seems to be essential in order to achieve an accurate environmental-noise prediction in cities. This problem is addressed in this paper, where a procedure based on feature-selection techniques and machine-learning regression methods is proposed and applied to this environmental problem. Three machine-learning regression methods, which are considered very robust in solving non-linear problems, are used to estimate the energy-equivalent sound-pressure level descriptor (LAeq). These three methods are: (i) multilayer perceptron (MLP), (ii) sequential minimal optimisation (SMO), and (iii) Gaussian processes for regression (GPR). In addition, because of the high number of input variables involved in environmental-noise modelling and estimation in urban environments, which make LAeq prediction models quite complex and costly in terms of time and resources for application to real situations, three different techniques are used to approach feature selection or data reduction. The feature-selection techniques used are: (i) correlation-based feature-subset selection (CFS), (ii) wrapper for feature-subset selection (WFS), and the data reduction technique is principal-component analysis (PCA). The subsequent analysis leads to a proposal of different schemes, depending on the needs regarding data collection and accuracy. The use of WFS as the feature-selection technique with the implementation of SMO or GPR as regression algorithm provides the best LAeq estimation (R(2)=0.94 and mean absolute error (MAE)=1.14-1.16 dB(A)). Copyright © 2014 Elsevier B.V. All rights reserved.

  17. [Influence of selected endogenous and environmental factors on the course and complications of Grave's disease].

    Science.gov (United States)

    Kurzynska, Anna; Przybylik-Mazurek, Elwira; Węgrzynowicz, Katarzyna; Morzywołek, Aleksandra; Wieczorek, Agata; Żarnowska, Maja; Hubalewska-Dydejczyk, Alicja

    2014-01-01

    Graves' disease (GD) is an autoimmune thyroid disease with complex and not fully established etiology. It occurs when environmental factors influence people genetically prone to this illness. The aim of this study was to determine the impact of selected factors (endogenous and environmental) on the course and complications of disease in patients with recurrent GD. Two hundred and four patients with relapsed GD, treated in the Clinical Department of Endocrinology in University Hospital in Cracow in years 2004-2006 and then in 2011 were retrospectively analyzed. Patients who agreed to participate in the study were sent questionnaire to complete. Demographic and clinical data were collected and entered into a database. Patient data included: gender, place of living, lifestyle (smoking), family history of autoimmune diseases, the course of the disease, its symptoms and the treatment strategy. Furthermore the medical documentation was analyzed. Descriptive statistical analyses were made. The study showed a significant difference in the frequency of appearance of ophthalmopathy between men and women (80% and 37.14%, respectively, p = 0.041), between smokers and nonsmokers (61.9% and 21.05%, respectively, p = 0.022) and between the age of patients with positive and negative family history of autoimmune diseases (37.6 years and 50.5 years respectively, p = 0.002). 1. Male gender is a risk factor for ophthalmopathy in GD. 2. Cigarette smoking affects the risk of Graves' ophthalmopathy. 3. A positive family history of thyroid diseases and/or autoimmune diseases promotes the development of GD at a younger age.

  18. Environmental carbonate chemistry selects for phenotype of recently isolated strains of Emiliania huxleyi

    Science.gov (United States)

    Rickaby, Rosalind E. M.; Hermoso, Michaël; Lee, Renee B. Y.; Rae, Benjamin D.; Heureux, Ana M. C.; Balestreri, Cecilia; Chakravarti, Leela; Schroeder, Declan C.; Brownlee, Colin

    2016-05-01

    Coccolithophorid algae, particularly Emiliania huxleyi, are prolific biomineralisers that, under many conditions, dominate communities of marine eukaryotic plankton. Their ability to photosynthesise and form calcified scales (coccoliths) has placed them in a unique position in the global carbon cycle. Contrasting reports have been made with regards to the response of E. huxleyi to ocean acidification. Therefore, there is a pressing need to further determine the fate of this key organism in a rising CO2 world. In this paper, we investigate the phenotype of newly isolated, genetically diverse, strains of E. huxleyi from UK Ocean Acidification Research Programme (UKOA) cruises around the British Isles, the Arctic, and the Southern Ocean. We find a continuum of diversity amongst the physiological and photosynthetic parameters of different strains of E. huxleyi morphotype A under uniform, ambient conditions imposed in the laboratory. This physiology is best explained by adaptation to carbonate chemistry in the former habitat rather than being prescribed by genetic fingerprints such as the coccolithophore morphology motif (CMM). To a first order, the photosynthetic capacity of each strain is a function of both aqueous CO2 availability, and calcification rate, suggestive of a link between carbon concentrating ability and calcification. The calcification rate of each strain is related linearly to the natural environmental [CO32-] at the site of isolation, but a few exceptional strains display low calcification rates at the highest [CO32-] when calcification is limited by low CO2 availability and/or a lack of a carbon concentrating mechanism. We present O2-electrode measurements alongside coccolith oxygen isotopic composition and the uronic acid content (UAC) of the coccolith associated polysaccharide (CAP), that act as indirect tools to show the differing carbon concentrating ability of the strains. The environmental selection revealed amongst our recently isolated strain

  19. Environmental risk factors and health outcomes in selected communities of the Niger delta area, Nigeria.

    Science.gov (United States)

    Ana, Godson; Sridhar, Mynepalli K C; Bamgboye, Elijah A

    2009-07-01

    The main aim of this study was to assess the prevalence of various health outcomes associated with exposure to environmental risk factors including industrial pollution in selected communities of Nigeria's oil-rich Niger delta area (NDA). The study involved both laboratory experiments and community health surveys using questionnaires and hospital records. A total of 14 air samples, 16 grab soil samples and 18 surface water samples were collected and analyzed for physicochemical parameters including heavy metals and polycyclic aromatic hydrocarbons (PAHs) using standard methods. A 77-item questionnaire was administered on randomly selected 349 subjects. A five-year record was collected from health facilities located in the two communities. The laboratory results indicated that the median PAH level at Eleme as compared to Ahoada East was higher than the guideline limit 50 ng/l for surface waters. The mean TSP level at Eleme was higher than the level at Ahoada East and the guideline limit 100 microg/m3. The median PAH level at Eleme was higher than the level at Ahoada East and the guideline limit problem (p = 0.044). At Ahoada East commonly consumed aquatic food was highly significantly associated with painful body outgrowth (p fuel types was also highly significantly associated with child deformities (p < 0.0001). Hospital records showed high proportions of respiratory disorder among males (3.85%) and females (4.39%) at Eleme as compared to the proportion of respiratory disorder among males (3.68%) and females (4.18%) at Ahoada East. The study shows that industrial communities such as Eleme, which are exposed to higher levels of air pollution, are more predisposed to respiratory morbidities, skin disorders and other related health risks.

  20. Aqueous magnesium as an environmental selection pressure in the evolution of phospholipid membranes on early earth

    Science.gov (United States)

    Dalai, Punam; Ustriyana, Putu; Sahai, Nita

    2018-02-01

    Early compartmentalization of simple biomolecules by membrane bilayers was, presumably, a critical step in the emergence of the first cell-like entities, protocells. Their membranes were likely composed of single chain amphiphiles (SCAs), but pure SCA membranes especially those with short-chains are highly unstable towards divalent cations, which are ubiquitous in aqueous environments. The prebiotic synthesis of phospholipids (PLs), even in only trace amounts, may also have been possible. PL membranes are much more stable towards divalent cations. Here, we show the transition of fatty acid membranes to mixed fatty acid-PL and, finally, to PL membranes in the presence of Mg2+, which acts as an environmental selection pressure, and we propose different mechanisms for the observed increased Mg2+-immunity. The "fatal" concentration ([Mg2+]fatal) at which vesicles are disrupted increased dramatically by an order of magnitude from OA to mixed to POPC vesicles. Two mechanisms for the increasing immunity were determined. The negative charge density of the vesicles decreased with increasing POPC content, so more Mg2+ was required for disruption. More interestingly, Mg2+ preferentially bound to and abstracted OA from mixed lipid membranes, resulting in relatively POPC-enriched vesicles compared to the initial ratio. The effect was the most dramatic for the largest initial OA-POPC ratio representing the most primitive protocells. Thus, Mg2+ acted to evolve the mixed membrane composition towards PL enrichment. To the best of our knowledge, this is the first report of selective lipid abstraction from mixed SCA-PL vesicles. These results may hold implications for accommodating prebiotic Mg2+-promoted processes such as non-enzymatic RNA polymerization on early Earth.

  1. Climate-related environmental variation in a visual signalling device: the male and female dewlap in Anolis sagrei lizards.

    Science.gov (United States)

    Driessens, T; Baeckens, S; Balzarolo, M; Vanhooydonck, B; Huyghe, K; Van Damme, R

    2017-10-01

    Animals communicate using a variety of signals that differ dramatically among and within species. The astonishing dewlap diversity in anoles has attracted considerable attention in this respect. Yet, the evolutionary processes behind it remain elusive and have mostly been explored for males only. Here, we considered Anolis sagrei males and females to study signal divergence among populations. First, we assessed the degree of variation in dewlap design (size, pattern and colour) and displays by comparing 17 populations distributed across the Caribbean. Second, we assessed whether the observed dewlap diversity is associated with variation in climate-related environmental conditions. Results showed that populations differed in all dewlap characteristics, with the exception of display rate in females. We further found that males and females occurring in 'xeric' environments had a higher proportion of solid dewlaps with higher UV reflectance. In addition, lizards inhabiting 'mesic' environments had primarily marginal dewlaps showing high reflectance in red. For dewlap display, a correlation with environment was only observed in males. Our study provides evidence for a strong relationship between signal design and prevailing environmental conditions, which may result from differential selection on signal efficacy. Moreover, our study highlights the importance of including females when studying dewlaps in an evolutionary context. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  2. Preliminary environmental assessment of selected geopressured - geothermal prospect areas: Louisiana Gulf Coast Region. Volume II. Environmental baseline data

    Energy Technology Data Exchange (ETDEWEB)

    Newchurch, E.J.; Bachman, A.L.; Bryan, C.F.; Harrison, D.P.; Muller, R.A.; Newman, J.P. Jr.; Smith, C.G. Jr.; Bailey, J.I. Jr.; Kelly, G.G.; Reibert, K.C.

    1978-10-15

    A separate section is presented for each of the six prospect areas studied. Each section includes a compilation and discussion of environmental baseline data derived from existing sources. The data are arranged as follows: geology and geohydrology, air quality, water resources and flood hazards, ecological systems, and land use. When data specific to the prospect were not available, regional data are reported. (MHR)

  3. Environmental effect and fate of selected phenols in aquatic ecosystems using microcosm approaches

    International Nuclear Information System (INIS)

    Portier, R.J.; Chen, H.M.; Meyers, S.P.

    1983-01-01

    Microbiological studies, together with physicochemical analyses of selected industrial source phenols of environmental significance, were conducted in continuous flow and carbon metabolism microcosms to determine the behavior of these priority pollutants in soil and sediment-water systems typical of coastal wetlands. Phenols used included 4- nitrophenol, 2,4,6-trichlorophenol, 2-chlorophenol, and phenol. The organophosphate, 14 C-UL-Methyl Parathion, was used as a benchmark toxicant control while 14 C-Ring-Phenol was employed for all phenolic compound additions. Microbial diversity, ATP, and specific enzyme systems (i.e., phosphatase, dehydrogenase) were continuously monitored along with 14 CO 2 expiration and 14 C assimilation by the cellular component. Residual analysis of all microcosm tests employed procedures using combined gas chromatography/high-performance liquid chromatography. Statistical analyses were conducted of variations of testing criteria, along with a ranking profile of relative biotransformation and biodegradation potential. Data presented confirm the validity of microcosm approaches and related correlation analysis in toxic substance fate investigations. 17 references, 6 figures, 1 table

  4. Compact development and VMT: environmental determinism, self-selection, or some of both?

    Science.gov (United States)

    Ewing, Reid; Hamidi, Shima; Grace, James B.

    2016-01-01

    There is a long-running debate in the planning literature about the effects of the built environment on travel behavior and the degree to which apparent effects are due to the tendency of households to self-select into neighborhoods that reinforce their travel preferences. Those who want to walk will choose walkable neighborhoods, and those who want to use transit will choose transit-served neighborhoods. These households might have walked or used transit more than their neighbors wherever they lived. Most previous studies have shown that individual attitudes attenuate the relationship between the residential environment and travel choices, and so the effect of the built environment on travel may be overestimated. But there are other researchers who argue the reverse, claiming that residential preferences reinforce built environmental influences. This study assesses the relative importance of the built environment and residential preferences/travel attitudes for a sample of 962 households in the Greater Salt Lake region using structural equation modeling. For the sake of simplicity, we extracted two factors using principal component analysis, one representing the built environment and the other representing residential preferences/attitudes. Our findings are consistent with the view that the neighborhood built environment and residential preferences both influence household’s travel, that the built environment is the stronger influence, and that the built environment affects travel through two causal pathways, one direct and the other indirect, through attitudes.

  5. Procedure to select test organisms for environmental risk assessment of genetically modified crops in aquatic systems.

    Science.gov (United States)

    Hilbeck, Angelika; Bundschuh, Rebecca; Bundschuh, Mirco; Hofmann, Frieder; Oehen, Bernadette; Otto, Mathias; Schulz, Ralf; Trtikova, Miluse

    2017-11-01

    For a long time, the environmental risk assessment (ERA) of genetically modified (GM) crops focused mainly on terrestrial ecosystems. This changed when it was scientifically established that aquatic ecosystems are exposed to GM crop residues that may negatively affect aquatic species. To assist the risk assessment process, we present a tool to identify ecologically relevant species usable in tiered testing prior to authorization or for biological monitoring in the field. The tool is derived from a selection procedure for terrestrial ecosystems with substantial but necessary changes to adequately consider the differences in the type of ecosystems. By using available information from the Water Framework Directive (2000/60/EC), the procedure can draw upon existing biological data on aquatic systems. The proposed procedure for aquatic ecosystems was tested for the first time during an expert workshop in 2013, using the cultivation of Bacillus thuringiensis (Bt) maize as the GM crop and 1 stream type as the receiving environment in the model system. During this workshop, species executing important ecological functions in aquatic environments were identified in a stepwise procedure according to predefined ecological criteria. By doing so, we demonstrated that the procedure is practicable with regard to its goal: From the initial long list of 141 potentially exposed aquatic species, 7 species and 1 genus were identified as the most suitable candidates for nontarget testing programs. Integr Environ Assess Manag 2017;13:974-979. © 2017 SETAC. © 2017 SETAC.

  6. Determination of specific activity of americium and plutonium in selected environmental samples

    International Nuclear Information System (INIS)

    Trebunova, T.

    1999-01-01

    The aim of this work was development of method for determination of americium and plutonium in environmental samples. Developed method was evaluated on soil samples and after they was applied on selected samples of fishes (smoked mackerel, herring and fillet from Alaska hake). The method for separation of americium is based on liquid separation with Aliquate-336, precipitation with oxalic acid and using of chromatographic material TRU-Spec TM .The intervals of radiochemical yields were from 13.0% to 80.9% for plutonium-236 and from 10.5% to 100% for americium-241. Determined specific activities of plutonium-239,240 were from (2.3 ± 1.4) mBq/kg to (82 ± 29) mBq/kg, the specific activities of plutonium-238 were from (14.2 ± 3.7) mBq/kg to (708 ± 86) mBq/kg. The specific activities of americium-241 were from (1.4 ± 0.9) mBq/kg to (3360 ± 210) mBq/kg. The fishes from Baltic Sea as well as from North Sea show highest specific activities then fresh-water fishes from Slovakia. Therefore the monitoring of alpha radionuclides in foods imported from territories with nuclear testing is recommended

  7. Environmental implications of thorium use in selected nuclear fuel cycles. Final

    International Nuclear Information System (INIS)

    Buckley, D.W.; Simmons, G.L.; Ziskind, R.A.

    1978-01-01

    The objective of this study was to assess the environmental implications of the nuclear fuel cycle associated with the highly enriched uranium concept of the High Temperature Gas Cooled Reactor. Model fuel cycles were constructed for the HTGR and a reference light water reactor (LWR) cycle. Mass flows were developed, control technology cases proposed and costed, effluents determined, and population doses calculated. Emphasis was given to the intercomparison of the fuel cycles to delineate areas which show pronounced departure. The dose commitment received by the population both within and outside a radius of 50 miles of each facility was determined. The 100 year population dose commitments due to a single year's plant operation was selected to facilitate intercomparison among fuel cycle components. No account was taken for long term waste sources associated with the fuel cycle such as mill tailing piles or terminal waste storage (study groundrule). The resource utilization and radionuclide activity of various fuel cycle options for using thorium in a Pressurized Water Reactor were studied. These data were contrasted with similar results obtained for a uranium fuel PWR

  8. Selection of dominant radionuclides for Phase 1 of the Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.

    1991-07-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of emissions from nuclear operations at Hanford since their inception in 1944. A vital step in the estimation of radiation doses is the determination of the source term,'' that is, the quantities of radionuclides that were released to the environment from the various Hanford operations. Hanford operations have at various times involved hundreds of different radionuclides, some in relatively large quantities. Those radionuclides present in the largest quantities, although significant from an operational handling point of view, may not necessarily have been those of greatest concern for offsite radiation dose. This report documents the selection of the dominant radionuclides (those that may have resulted in the largest portion of the received doses) in the source term for Phase 1 of the HEDR Project, that is, for atmospheric releases from 1944 through 1947 and for surface water releases from 1964 through 1966. 15 refs., 3 figs., 10 tabs.

  9. Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

    Science.gov (United States)

    Shiba, Tomonori; Mii, Masahiro

    2005-12-01

    Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

  10. Develop an asset management tool for collecting and tracking commitments on selected environmental mitigation features.

    Science.gov (United States)

    2009-05-01

    Wisconsin has constructed many environmental mitigation projects in conjunction with transportation projects that have been implemented according : to the National Environmental Policy Act. Other mitigation projects have been constructed pursuant to ...

  11. The Integration of Pedagogical Aspects in Environmental Management Systems in Selected South African Primary Schools

    Science.gov (United States)

    Kanyimba, Alex; Richter, Barry; Raath, Schalk

    2015-01-01

    Environmental management systems implemented in schools are regarded by many as a mechanism for the integration of environmental matters in all the operational functions of the school. The links, however, between environmental management and curriculum practice have not been adequately addressed in the literature. This article reports on the…

  12. Prediction of breeding values and selection responses with genetic heterogeneity of environmental variance

    NARCIS (Netherlands)

    Mulder, H.A.; Bijma, P.; Hill, W.G.

    2007-01-01

    There is empirical evidence that genotypes differ not only in mean, but also in environmental variance of the traits they affect. Genetic heterogeneity of environmental variance may indicate genetic differences in environmental sensitivity. The aim of this study was to develop a general framework

  13. Effects of inter- and intramodal selective attention to non-spatial visual stimuli: An event-related potential analysis.

    NARCIS (Netherlands)

    de Ruiter, M.B.; Kok, A.; van der Schoot, M.

    1998-01-01

    Event-related potentials (ERPs) were recorded to trains of rapidly presented auditory and visual stimuli. ERPs in conditions in which Ss attended to different features of visual stimuli were compared with ERPs to the same type of stimuli when Ss attended to different features of auditory stimuli,

  14. Environmental considerations in the selection of isolation gowns: A life cycle assessment of reusable and disposable alternatives.

    Science.gov (United States)

    Vozzola, Eric; Overcash, Michael; Griffing, Evan

    2018-04-11

    Isolation gowns serve a critical role in infection control by protecting healthcare workers, visitors, and patients from the transfer of microorganisms and body fluids. The decision of whether to use a reusable or disposable garment system is a selection process based on factors including sustainability, barrier effectiveness, cost, and comfort. Environmental sustainability is increasingly being used in the decision-making process. Life cycle assessment is the most comprehensive and widely used tool used to evaluate environmental performance. The environmental impacts of market-representative reusable and disposable isolation gown systems were compared using standard life cycle assessment procedures. The basis of comparison was 1,000 isolation gown uses in a healthcare setting. The scope included the manufacture, use, and end-of-life stages of the gown systems. At the healthcare facility, compared to the disposable gown system, the reusable gown system showed a 28% reduction in energy consumption, a 30% reduction in greenhouse gas emissions, a 41% reduction in blue water consumption, and a 93% reduction in solid waste generation. Selecting reusable garment systems may result in significant environmental benefits compared to selecting disposable garment systems. By selecting reusable isolation gowns, healthcare facilities can add these quantitative benefits directly to their sustainability scorecards. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  15. From Reactionary to Responsive: Applying the Internal Environmental Scan Protocol to Lifelong Learning Strategic Planning and Operational Model Selection

    Science.gov (United States)

    Downing, David L.

    2009-01-01

    This study describes and implements a necessary preliminary strategic planning procedure, the Internal Environmental Scanning (IES), and discusses its relevance to strategic planning and university-sponsored lifelong learning program model selection. Employing a qualitative research methodology, a proposed lifelong learning-centric IES process…

  16. Environmental settings for selected US Department of Energy installations - support information for the programmatic environmental impact statement and the baseline environmental management report

    Energy Technology Data Exchange (ETDEWEB)

    Holdren, G.R.; Glantz, C.S.; Berg, L.K.; Delinger, K.; Fosmire, C.J.; Goodwin, S.M.; Rustad, J.R.; Schalla, R.; Schramke, J.A.

    1995-05-01

    This report contains the environmental setting information developed for 25 U.S. Department of Energy (DOE) installations in support of the DOE`s Programmatic Environmental Impact Study (PEIS) and the Baseline Environmental Management Report (BEMR). The common objective of the PEIS and the BEMR is to provide the public with information about the environmental contamination problems associated with major DOE facilities across the country, and to assess the relative risks that radiological and hazardous contaminants pose to the public, onsite workers, and the environment. Environmental setting information consists of the site-specific data required to model (using the Multimedia Environmental Pollutant Assessment System) the atmospheric, groundwater, and surface water transport of contaminants within and near the boundaries of the installations. The environmental settings data describes the climate, atmospheric dispersion, hydrogeology, and surface water characteristics of the installations. The number of discrete environmental settings established for each installation was governed by two competing requirements: (1) the risks posed by contaminants released from numerous waste sites were to be modeled as accurately as possible, and (2) the modeling required for numerous release sites and a large number of contaminants had to be completed within the limits imposed by the PEIS and BEMR schedule. The final product is the result of attempts to balance these competing concerns in a way that minimizes the number of settings per installation in order to meet the project schedule while at the same, time providing adequate, if sometimes highly simplified, representations of the different areas within an installation. Environmental settings were developed in conjunction with installation experts in the fields of meteorology, geology, hydrology, and geochemistry.

  17. Environmental settings for selected US Department of Energy installations - support information for the programmatic environmental impact statement and the baseline environmental management report

    International Nuclear Information System (INIS)

    Holdren, G.R.; Glantz, C.S.; Berg, L.K.; Delinger, K.; Fosmire, C.J.; Goodwin, S.M.; Rustad, J.R.; Schalla, R.; Schramke, J.A.

    1995-05-01

    This report contains the environmental setting information developed for 25 U.S. Department of Energy (DOE) installations in support of the DOE's Programmatic Environmental Impact Study (PEIS) and the Baseline Environmental Management Report (BEMR). The common objective of the PEIS and the BEMR is to provide the public with information about the environmental contamination problems associated with major DOE facilities across the country, and to assess the relative risks that radiological and hazardous contaminants pose to the public, onsite workers, and the environment. Environmental setting information consists of the site-specific data required to model (using the Multimedia Environmental Pollutant Assessment System) the atmospheric, groundwater, and surface water transport of contaminants within and near the boundaries of the installations. The environmental settings data describes the climate, atmospheric dispersion, hydrogeology, and surface water characteristics of the installations. The number of discrete environmental settings established for each installation was governed by two competing requirements: (1) the risks posed by contaminants released from numerous waste sites were to be modeled as accurately as possible, and (2) the modeling required for numerous release sites and a large number of contaminants had to be completed within the limits imposed by the PEIS and BEMR schedule. The final product is the result of attempts to balance these competing concerns in a way that minimizes the number of settings per installation in order to meet the project schedule while at the same, time providing adequate, if sometimes highly simplified, representations of the different areas within an installation. Environmental settings were developed in conjunction with installation experts in the fields of meteorology, geology, hydrology, and geochemistry

  18. Selective leaching of Zn from spent alkaline batteries using environmentally friendly approaches.

    Science.gov (United States)

    Maryam Sadeghi, S; Vanpeteghem, Guillaumme; Neto, Isabel F F; Soares, Helena M V M

    2017-02-01

    The main aim of this work was to evaluate the possibility of using microwave or ultrasound to assist the efficient and selective leaching of Zn from spent alkaline batteries and compare the results with those obtained using the conventional method. Two different strategies were applied: acid leaching of a washed residue and alkaline leaching of the original residue. In both (acid and alkaline) approaches, the use of microwave- or ultrasound-assisted leaching increased the extraction of Zn compared with the best results obtained using conventional leaching [acid leaching (1.5mol/L H 2 SO 4 , 3h, 80°C), 90% of Zn extracted; alkaline leaching (6mol/L NaOH, 3h, 80°C), 42% of Zn extracted]. With acid leaching, 94% of the Zn was extracted using microwave-assisted leaching (1 cycle, 30s, 1mol/L H 2 SO 4 ), and 92% of the Zn was extracted using ultrasound-assisted leaching (2min, 0.1p, 20% amplitude, 1mol/L H 2 SO 4 ). Ultrasound-assisted leaching resulted in a more selective (Zn/Mn ratio of 5.1) Zn extraction than microwave-assisted leaching (Zn/Mn ratio of 3.5); both processes generated a concentrated Zn solution (⩾18.7g/L) with a purity (83.3% and 77.7%, respectively) that was suitable for electrowinning. With alkaline leaching, microwave- (1 cycle, 3 min, 4mol/L NaOH) and ultrasound-assisted (14min, 0.1p, 20% amplitude, 4mol/L NaOH) leaching extracted about 80% of the Zn and less than 0.01% of the Mn, which resulted in lesser concentrated Zn solutions (approximately 16.5g/L) but with high purity (>99.5%) that was suitable for the recovery of Zn by precipitation. The microwave- and ultrasound-assisted leaching strategies used in this work proved to be efficient and environmentally-friendly approaches for the extraction of Zn from spent alkaline residues since a concentrated Zn solution with adequate purity for subsequent Zn recovery was obtained using significantly decreased leaching times and concentrations of chemicals. Copyright © 2017 Elsevier Ltd. All rights

  19. The prefrontal cortex shows context-specific changes in effective connectivity to motor or visual cortex during the selection of action or colour

    DEFF Research Database (Denmark)

    Rowe, James B.; Stephan, Klaas E.; Friston, Karl

    2005-01-01

    The role of the prefrontal cortex remains controversial. Neuroimaging studies support modality-specific and process-specific functions related to working memory and attention. Its role may also be defined by changes in its influence over other brain regions including sensory and motor cortex. We...... used functional magnetic imaging (fMRI) to study the free selection of actions and colours. Control conditions used externally specified actions and colours. The prefrontal cortex was activated during free selection, regardless of modality, in contrast to modality-specific activations outside...... included high-order interactions between modality, selection and regional activity. There was greater coupling between prefrontal cortex and motor cortex during free selection and action tasks, and between prefrontal cortex and visual cortex during free selection of colours. The results suggest...

  20. Selection of filter media in alpha air monitors for emergency environmental monitoring

    International Nuclear Information System (INIS)

    Kinouchi, N.; Oishi, T.; Noguchi, H.; Kato, S.

    2000-01-01

    We have developed an alpha air monitor which is possible to measure rapidly and sensitively the concentrations of airborne alpha-emitting particles, such as plutonium, for the environmental monitoring at an accident of nuclear reprocessing plant. The monitor is designed to collect airborne alpha-emitting particles by drawing the ambient air through a filter and to detect the activity by alpha spectroscopy. In order to achieve high-sensitive measurements, selection of a suitable filter used in the monitor is considerably important. The most important requirement for the filter is that it has a high surface collection efficiency to obtain the sharpness of the alpha energy spectrum. This makes it easy to distinguish the alpha-ray peak of plutonium from the alpha spectrum of naturally occurring radon decay products in the environment. And the filter is also desired to have low resistance of the air flow so that particles can be collected at a high flowrate. We have made a comparison of the surface collection efficiency and pressure drop for the various filters. Types of the test filters, most of which are commercially available in Japan, were glass fiber, cellulose-glass fiber, membrane and so on. The surface collection efficiency has been evaluated by the following two indices. One was the sharpness of alpha-ray energy peaks of thoron decay products generated in a laboratory and collected in the fibers. The other was the background counts of radon decay products in a plutonium region by measuring alpha-ray energy spectrum of radon decay products collected in the filters by sampling of dust in the atmosphere. It was found that the PTFE (polytetrafluoroethylene) membrane filter with backing had a high surface collection efficiency and low pressure drop. The results of the test are described in detail in this paper. (author)

  1. Unsupervised binning of environmental genomic fragments based on an error robust selection of l-mers.

    Science.gov (United States)

    Yang, Bin; Peng, Yu; Leung, Henry Chi-Ming; Yiu, Siu-Ming; Chen, Jing-Chi; Chin, Francis Yuk-Lun

    2010-04-16

    With the rapid development of genome sequencing techniques, traditional research methods based on the isolation and cultivation of microorganisms are being gradually replaced by metagenomics, which is also known as environmental genomics. The first step, which is still a major bottleneck, of metagenomics is the taxonomic characterization of DNA fragments (reads) resulting from sequencing a sample of mixed species. This step is usually referred as "binning". Existing binning methods are based on supervised or semi-supervised approaches which rely heavily on reference genomes of known microorganisms and phylogenetic marker genes. Due to the limited availability of reference genomes and the bias and instability of marker genes, existing binning methods may not be applicable in many cases. In this paper, we present an unsupervised binning method based on the distribution of a carefully selected set of l-mers (substrings of length l in DNA fragments). From our experiments, we show that our method can accurately bin DNA fragments with various lengths and relative species abundance ratios without using any reference and training datasets. Another feature of our method is its error robustness. The binning accuracy decreases by less than 1% when the sequencing error rate increases from 0% to 5%. Note that the typical sequencing error rate of existing commercial sequencing platforms is less than 2%. We provide a new and effective tool to solve the metagenome binning problem without using any reference datasets or markers information of any known reference genomes (species). The source code of our software tool, the reference genomes of the species for generating the test datasets and the corresponding test datasets are available at http://i.cs.hku.hk/~alse/MetaCluster/.

  2. Selective uptake and biological consequences of environmentally relevant antidepressant pharmaceutical exposures on male fathead minnows

    Science.gov (United States)

    Schultz, Melissa M.; Painter, Meghan M.; Bartell, Stephen E.; Logue, Amanda; Furlong, Edward T.; Werner, Stephen L.; Schoenfuss, Heiko L.

    2011-01-01

    Antidepressant pharmaceuticals have been reported in wastewater effluent at the nanogram to low microgram-per-liter range, and include bupropion (BUP), fluoxetine (FLX), sertraline (SER), and venlafaxine (VEN). To assess the effects of antidepressants on reproductive anatomy, physiology, and behavior, adult male fathead minnows (Pimeplwles promelas) were exposed for 21 days either to a single concentration of the antidepressants FLX, SER, VEN, or BUP, or to an antidepressant mixture. The data demonstrated that exposure to VEN (305 ng/L and 1104 ng/L) and SER (5.2 ng/L) resulted in mortality. Anatomical alterations were noted within the testes of fish exposed to SER and FLX, both modulators of the neurotransmitter serotonin. Additionally, FLX at 28 ng/L induced vitellogenin in male fish—a common endpoint for estrogenic endocrine disruption. Significant alterations in male secondary sex characteristics were noted with single exposures. Effects of single compound exposures neither carried over, nor became additive in the antidepressant mixtures, and reproductive behavior was not affected. Analysis of brain tissues from the exposed fish suggested increased uptake of FLX, SER and BUP and minimal uptake of VEN when compared to exposure water concentrations. Furthermore, the only metabolite detected consistently in the brain tissues was norfluoxetine. Similar trends of uptake by brain tissue were observed when fish were exposed to antidepressant mixtures. The present study demonstrates that anatomy and physiology, but not reproductive behavior, can be disrupted by exposure to environmental concentrations of some antidepressants. The observation that antidepressant uptake into fish tissues is selective may have consequences on assessing the mode-of-action and effects of these compounds in future studies.

  3. Effects of Information Visualization on Older Adults' Decision-Making Performance in a Medicare Plan Selection Task: A Comparative Usability Study.

    Science.gov (United States)

    Price, Margaux M; Crumley-Branyon, Jessica J; Leidheiser, William R; Pak, Richard

    2016-06-01

    Technology gains have improved tools for evaluating complex tasks by providing environmental supports (ES) that increase ease of use and improve performance outcomes through the use of information visualizations (info-vis). Complex info-vis emphasize the need to understand individual differences in abilities of target users, the key cognitive abilities needed to execute a decision task, and the graphical elements that can serve as the most effective ES. Older adults may be one such target user group that would benefit from increased ES to mitigate specific declines in cognitive abilities. For example, choosing a prescription drug plan is a necessary and complex task that can impact quality of life if the wrong choice is made. The decision to enroll in one plan over another can involve comparing over 15 plans across many categories. Within this context, the large amount of complex information and reduced working memory capacity puts older adults' decision making at a disadvantage. An intentionally designed ES, such as an info-vis that reduces working memory demand, may assist older adults in making the most effective decision among many options. The objective of this study is to examine whether the use of an info-vis can lower working memory demands and positively affect complex decision-making performance of older adults in the context of choosing a Medicare prescription drug plan. Participants performed a computerized decision-making task in the context of finding the best health care plan. Data included quantitative decision-making performance indicators and surveys examining previous history with purchasing insurance. Participants used a colored info-vis ES or a table (no ES) to perform the decision task. Task difficulty was manipulated by increasing the number of selection criteria used to make an accurate decision. A repeated measures analysis was performed to examine differences between the two table designs. Twenty-three older adults between the ages of 66

  4. Developmental memory capacity resources of typical children retrieving picture communication symbols using direct selection and visual linear scanning with fixed communication displays.

    Science.gov (United States)

    Wagner, Barry T; Jackson, Heather M

    2006-02-01

    This study examined the cognitive demands of 2 selection techniques in augmentative and alternative communication (AAC), direct selection, and visual linear scanning, by determining the memory retrieval abilities of typically developing children when presented with fixed communication displays. One hundred twenty typical children from kindergarten, 1st, and 3rd grades were randomly assigned to either a direct selection or visual linear scanning group. Memory retrieval was assessed through word span using Picture Communication Symbols (PCSs). Participants were presented various numbers and arrays of PCSs and asked to retrieve them by placing identical graphic symbols on fixed communication displays with grid layouts. The results revealed that participants were able to retrieve more PCSs during direct selection than scanning. Additionally, 3rd-grade children retrieved more PCSs than kindergarten and 1st-grade children. An analysis on the type of errors during retrieval indicated that children were more successful at retrieving the correct PCSs than the designated location of those symbols on fixed communication displays. AAC practitioners should consider using direct selection over scanning whenever possible and account for anticipatory monitoring and pulses when scanning is used in the service delivery of children with little or no functional speech. Also, researchers should continue to investigate AAC selection techniques in relationship to working memory resources.

  5. Exploring Environmental Disclosure in SelectedAustralian Multinationals under the GRI Guidelines

    Directory of Open Access Journals (Sweden)

    Omar Al Farooque

    2014-09-01

    Full Text Available This paper explores changes in environmental reporting among Australian MNEs between 2004 and 2007, using the GRI guidelines, and explains how GRI transformation (from G2 to G3 leads to changes in environmental disclosure aspects along with their association with company size, profitability, industry sector. Applying Wilcoxon matched pair signed ranked and Spearman rank correlation tests, twenty companies from the Australian SAM Sustainability Index (AuSSI are examined to identify the extent of changes on specific aspects of environmental disclosure. The findings of the paper document a significant increase in environmental reporting in Australian companies. In particular, reporting has increased for energy, emissions and environmental management followed by water, overall, materials, transport and product/services aspects. However, a shift in emphasis from compliance and biodiversity aspects associated with climate changes and resource preservation is also evident. Again, the majority of changes occurred in companies operating in environmentally sensitive industries with industry sector having significant relationship with a few environmental disclosure aspects, the study shows no significant effect of company size and profitability on different environmental disclosure aspects. These evidences indicate that external forces (such as, legislation, industry sensitiveness to environment, and stakeholder awareness and pressure rather than internal factors are more effective to influence and determine environmental disclosure in Australian companies.

  6. Visualizing water

    Science.gov (United States)

    Baart, F.; van Gils, A.; Hagenaars, G.; Donchyts, G.; Eisemann, E.; van Velzen, J. W.

    2016-12-01

    A compelling visualization is captivating, beautiful and narrative. Here we show how melding the skills of computer graphics, art, statistics, and environmental modeling can be used to generate innovative, attractive and very informative visualizations. We focus on the topic of visualizing forecasts and measurements of water (water level, waves, currents, density, and salinity). For the field of computer graphics and arts, water is an important topic because it occurs in many natural scenes. For environmental modeling and statistics, water is an important topic because the water is essential for transport, a healthy environment, fruitful agriculture, and a safe environment.The different disciplines take different approaches to visualizing water. In computer graphics, one focusses on creating water as realistic looking as possible. The focus on realistic perception (versus the focus on the physical balance pursued by environmental scientists) resulted in fascinating renderings, as seen in recent games and movies. Visualization techniques for statistical results have benefited from the advancement in design and journalism, resulting in enthralling infographics. The field of environmental modeling has absorbed advances in contemporary cartography as seen in the latest interactive data-driven maps. We systematically review the design emerging types of water visualizations. The examples that we analyze range from dynamically animated forecasts, interactive paintings, infographics, modern cartography to web-based photorealistic rendering. By characterizing the intended audience, the design choices, the scales (e.g. time, space), and the explorability we provide a set of guidelines and genres. The unique contributions of the different fields show how the innovations in the current state of the art of water visualization have benefited from inter-disciplinary collaborations.

  7. A multi-objective optimization approach for the selection of working fluids of geothermal facilities: Economic, environmental and social aspects.

    Science.gov (United States)

    Martínez-Gomez, Juan; Peña-Lamas, Javier; Martín, Mariano; Ponce-Ortega, José María

    2017-12-01

    The selection of the working fluid for Organic Rankine Cycles has traditionally been addressed from systematic heuristic methods, which perform a characterization and prior selection considering mainly one objective, thus avoiding a selection considering simultaneously the objectives related to sustainability and safety. The objective of this work is to propose a methodology for the optimal selection of the working fluid for Organic Rankine Cycles. The model is presented as a multi-objective approach, which simultaneously considers the economic, environmental and safety aspects. The economic objective function considers the profit obtained by selling the energy produced. Safety was evaluated in terms of individual risk for each of the components of the Organic Rankine Cycles and it was formulated as a function of the operating conditions and hazardous properties of each working fluid. The environmental function is based on carbon dioxide emissions, considering carbon dioxide mitigation, emission due to the use of cooling water as well emissions due material release. The methodology was applied to the case of geothermal facilities to select the optimal working fluid although it can be extended to waste heat recovery. The results show that the hydrocarbons represent better solutions, thus among a list of 24 working fluids, toluene is selected as the best fluid. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Field verification of social and environmental issues of selected water sector projects in Punjab-Pakistan

    International Nuclear Information System (INIS)

    Ayesha, A.

    2012-01-01

    Irrigation helps in increasing the agricultural yield and the irrigation projects are carried out for the welfare of people. The importance of environment for sustainable development of irrigation projects has been realized. Environmental Impact Assessment is being increasingly used as a tool for appropriate environmental planning. In Pakistan, PEP A (Pakistan Environmental Protection Act),1997 establishes the framework to carry out Environmental Assessment of development projects. Various national and international agencies have developed Environmental Assessment Guidelines and Checklists for systematic evaluation of environmental impacts and their mitigation. The Social and Environmental Management Unit of Punjab Irrigation and Drainage Authority developed checklist for assessment of irrigation projects in 2007. The present study was conducted on three water sector projects namely: Concrete Lining of Dhudi Minor, Improving Nikki Deg Drain System and Rehabilitation of Khanki Barrage. The field verification of social and environmental issues of the projects was carried out according to the checklist of Social and Environmental Management Unit. The most noticeable impacts which were identified include: extended canal closure, emissions and effluents, waste generation and disposal, effect on flora, public health and safety, land acquisition, and social issues. The mitigatory measures proposed: proper project scheduling to minimize the canal closure periods, waste disposal through proper planning, preparation of detailed resettlement action plans and compensation, location of labor camps away from the settlements, avoiding unnecessary cutting of trees, and deployed machinery should be in good working condition. The recommendations of the study are to review and improve the checklists through a gradual and phased process into a more comprehensive social and environmental assessment process; capacity building of all the stake holders; collaboration between different

  9. Visual attention.

    Science.gov (United States)

    Evans, Karla K; Horowitz, Todd S; Howe, Piers; Pedersini, Roccardo; Reijnen, Ester; Pinto, Yair; Kuzmova, Yoana; Wolfe, Jeremy M

    2011-09-01

    A typical visual scene we encounter in everyday life is complex and filled with a huge amount of perceptual information. The term, 'visual attention' describes a set of mechanisms that limit some processing to a subset of incoming stimuli. Attentional mechanisms shape what we see and what we can act upon. They allow for concurrent selection of some (preferably, relevant) information and inhibition of other information. This selection permits the reduction of complexity and informational overload. Selection can be determined both by the 'bottom-up' saliency of information from the environment and by the 'top-down' state and goals of the perceiver. Attentional effects can take the form of modulating or enhancing the selected information. A central role for selective attention is to enable the 'binding' of selected information into unified and coherent representations of objects in the outside world. In the overview on visual attention presented here we review the mechanisms and consequences of selection and inhibition over space and time. We examine theoretical, behavioral and neurophysiologic work done on visual attention. We also discuss the relations between attention and other cognitive processes such as automaticity and awareness. WIREs Cogni Sci 2011 2 503-514 DOI: 10.1002/wcs.127 For further resources related to this article, please visit the WIREs website. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Variations in Carabidae assemblages across the farmland habitats in relation to selected environmental variables including soil properties

    Directory of Open Access Journals (Sweden)

    Beáta Baranová

    2018-03-01

    Full Text Available The variations in ground beetles (Coleoptera: Carabidae assemblages across the three types of farmland habitats, arable land, meadows and woody vegetation were studied in relation to vegetation cover structure, intensity of agrotechnical interventions and selected soil properties. Material was pitfall trapped in 2010 and 2011 on twelve sites of the agricultural landscape in the Prešov town and its near vicinity, Eastern Slovakia. A total of 14,763 ground beetle individuals were entrapped. Material collection resulted into 92 Carabidae species, with the following six species dominating: Poecilus cupreus, Pterostichus melanarius, Pseudoophonus rufipes, Brachinus crepitans, Anchomenus dorsalis and Poecilus versicolor. Studied habitats differed significantly in the number of entrapped individuals, activity abundance as well as representation of the carabids according to their habitat preferences and ability to fly. However, no significant distinction was observed in the diversity, evenness neither dominance. The most significant environmental variables affecting Carabidae assemblages species variability were soil moisture and herb layer 0-20 cm. Another best variables selected by the forward selection were intensity of agrotechnical interventions, humus content and shrub vegetation. The other from selected soil properties seem to have just secondary meaning for the adult carabids. Environmental variables have the strongest effect on the habitat specialists, whereas ground beetles without special requirements to the habitat quality seem to be affected by the studied environmental variables just little.

  11. Selectivity of neuronal [3H]GABA accumulation in the visual cortex as revealed by Golgi staining of the labeled neurons

    International Nuclear Information System (INIS)

    Somogyi, P.; Freund, T.F.; Kisvarday, Z.F.; Halasz, N.

    1981-01-01

    [ 3 H]GABA was injected into the visual cortex of rats in vivo. The labeled amino acid was demonstrated by autoradiography using semithin sections of Golgi material. Selective accumulation was seen in the perikarya of Golgi-stained, gold-toned, aspinous stellate neurons. Spine-laden pyramidal-like cells did not show labeling. This method gives direct information about the dendritic arborization of a neuron, and its putative transmitter, and allows the identification of its synaptic connections. (Auth.)

  12. Integrating environmental impact assessment into new product development and processing-technology selection

    NARCIS (Netherlands)

    Depping, Verena; Grunow, Martin; Middelaar, van Corina; Dumpler, Joseph

    2017-01-01

    Environmental-impact reduction potential is great early in new product development. To exploit this potential, this study evaluates novel combinations of existent processing technologies. Process engineering is combined with an environmental product assessment along the supply chain. In the dairy

  13. Hemi-ordered nanoporous carbon electrode material for highly selective determination of nitrite in physiological and environmental systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shenghai; Wu, Hongmin; Wu, Ying; Shi, Hongyan; Feng, Xun; Jiang, Shang; Chen, Jian; Song, Wenbo, E-mail: wbsong@jlu.edu.cn

    2014-08-01

    Hemi-ordered nanoporous carbon (HONC) was obtained from a mesoporous silica template through a nano-replication method using furfuryl alcohol as the carbon source. The structure and morphology of HONC were characterized and analyzed in detail by X-ray diffraction, N{sub 2}-sorption, Raman spectroscopy and transmission electron microscopy. HONC was then demonstrated as active electrode material for selective determination of nitrite in either physiological or environmental system. Well separated oxidation peaks of ascorbic acid, dopamine, uric acid and nitrite were observed in physiological system, and simultaneous discrimination of catechol, hydroquinone, resorcinol and nitrite in environmental system was also accomplished. Distinctly improved performances for selective determination of nitrite (such as significantly fast and sensitive current response with especially high selectivity) coexisted with ascorbic acid, dopamine and uric acid in the physiological system, as well as with catechol, hydroquinone and resorcinol in the environmental system were achieved at HONC electrode material. The excellent discriminating ability and high selectivity for NO{sub 2}{sup −} determination were ascribed to the good electronic conductivity, unique hemi-ordered porous structure, large surface area and large number of edge plane defect sites contained on the surface of nanopore walls of HONC. Results in this work demonstrated that HONC is one of the promising catalytic electrode materials for nitrite sensor fabrication. - Highlights: • Hemi-ordered nanoporous carbon as an active electrode material • Good discriminating ability towards NO{sub 2}{sup −} from physiological or environmental system • Highly selective determination of nitrite with fast and sensitive current response.

  14. Potential Visual Impacts of Utility-Scale Solar Energy Development within Solar Energy Zones on Selected Viewpoints in Death Valley and Joshua Tree National Parks, and El Camino Real De Tierra Adentro National Historic Trail

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Robert G. [Argonne National Lab. (ANL), Argonne, IL (United States); Abplanalp, Jennifer M. [Argonne National Lab. (ANL), Argonne, IL (United States); Cantwell, Brian L. [Argonne National Lab. (ANL), Argonne, IL (United States); Beckman, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-06-01

    In connection with the Bureau of Land Management’s (BLM’s) Solar Programmatic Environmental Impact Statement (Solar PEIS), Argonne National Laboratory (Argonne) has conducted an extended visual impact analysis for selected key observation points (KOPs) within three National Park Service (NPS) units located within the 25-mi (40-km) viewshed of four solar energy zones (SEZs) identified in the Solar PEIS. The analysis includes only those NPS units that the Solar PEIS identified as potentially subject to moderate or strong visual contrasts associated with solar development within the SEZs. The NPS units included in the analysis are Death Valley and Joshua Tree National Parks and El Camino Real De Tierra Adentro National Historic Trail. The analysis showed that certain KOPs in each of these NPS units could potentially be subject to major visual contrast and impacts from solar development within the SEZs, but many of the KOPs would likely be subject to moderate, minor, or negligible contrasts and impacts, generally because they were relatively distant from the relevant SEZ, had views of the SEZ partially blocked by intervening terrain, and/or had very low vertical angles of view toward the SEZ. For all three NPS units, power tower facilities were found to be major contributors to potential visual contrasts, primarily because of the long-distance visibility of intensely bright reflection of light from the receivers on the central towers, but also because of the height and strong vertical line of the tower structures and the potential for night-sky impacts from FAA-mandated hazard navigation lighting.

  15. Selection of environmental sustainable fiber materials for wind turbine blades - a contra intuitive process?

    Energy Technology Data Exchange (ETDEWEB)

    Birkved, M.; Corona, A. [Technical Univ. of Denmark. DTU Management Engineering, Kgs. Lyngby (Denmark); Markussen, C.M.; Madsen, Bo [Technical Univ. of Denmark. DTU Wind Energy, Risoe Campus, Roskilde (Denmark)

    2013-09-01

    Over the recent decades biomaterials have been marketed successfully supported by the common perception that biomaterials and environmental sustainability de facto represents two sides of the same coin. The development of sustainable composite materials such as blades for small-scale wind turbines have thus partially been focused on the substitution of conventional fiber materials with bio-fibers. The major question is if this material substitution actually, is environmental sustainable. In order to assess a wide pallet of environmental impacts and taking into account positive and negative environmental trade-offs over the entire life-span of composite materials, life cycle assessment (LCA) can be applied. In the present case study, four different types of fibers (carbon, glass, flax and carbon/flax mixture) are compared in terms of environmental sustainability and cost. Applying one of the most recent life cycle impact assessment methods, it is demonstrated that the environmental sustainability of the mixed carbon/flax fiber based composite material is better than that of the flax fibers alone. This observation may be contra-intuitive, but is mainly caused by the fact that the bio-material resin demand is by far exceeding the resin demand of the conventional fibers, and since the environmental burden of the resin is comparable to that of the fibers, resin demand is in terms of environmental sustainability important. On the other hand is the energy demand and associated environmental impacts in relation to the production of the carbon and glass fibers considerable compared to the impacts resulting from resin production. The ideal fiber solution, in terms of environmental sustainability, is hence the fiber composition having the lowest resin demand and lowest overall energy demand. The optimum environmental solution hence turns out to be a 70:30 flax:carbon mix, thereby minimizing the use of carbon fibers and resin. On top of the environmental sustainability

  16. Disruption of visual awareness during the attentional blink is reflected by selective disruption of late-stage neural processing

    Science.gov (United States)

    Harris, Joseph A.; McMahon, Alex R.; Woldorff, Marty G.

    2015-01-01

    Any information represented in the brain holds the potential to influence behavior. It is therefore of broad interest to determine the extent and quality of neural processing of stimulus input that occurs with and without awareness. The attentional blink is a useful tool for dissociating neural and behavioral measures of perceptual visual processing across conditions of awareness. The extent of higher-order visual information beyond basic sensory signaling that is processed during the attentional blink remains controversial. To determine what neural processing at the level of visual-object identification occurs in the absence of awareness, electrophysiological responses to images of faces and houses were recorded both within and outside of the attentional blink period during a rapid serial visual presentation (RSVP) stream. Electrophysiological results were sorted according to behavioral performance (correctly identified targets versus missed targets) within these blink and non-blink periods. An early index of face-specific processing (the N170, 140–220 ms post-stimulus) was observed regardless of whether the subject demonstrated awareness of the stimulus, whereas a later face-specific effect with the same topographic distribution (500–700 ms post-stimulus) was only seen for accurate behavioral discrimination of the stimulus content. The present findings suggest a multi-stage process of object-category processing, with only the later phase being associated with explicit visual awareness. PMID:23859644

  17. The Oil Point Method - A tool for indicative environmental evaluation in material and process selection

    DEFF Research Database (Denmark)

    Bey, Niki

    2000-01-01

    to three essential assessment steps, the method enables rough environmental evaluations and supports in this way material- and process-related decision-making in the early stages of design. In its overall structure, the Oil Point Method is related to Life Cycle Assessment - except for two main differences...... of environmental evaluation and only approximate information about the product and its life cycle. This dissertation addresses this challenge in presenting a method, which is tailored to these requirements of designers - the Oil Point Method (OPM). In providing environmental key information and confining itself...

  18. The visualCMAT: A web-server to select and interpret correlated mutations/co-evolving residues in protein families.

    Science.gov (United States)

    Suplatov, Dmitry; Sharapova, Yana; Timonina, Daria; Kopylov, Kirill; Švedas, Vytas

    2018-04-01

    The visualCMAT web-server was designed to assist experimental research in the fields of protein/enzyme biochemistry, protein engineering, and drug discovery by providing an intuitive and easy-to-use interface to the analysis of correlated mutations/co-evolving residues. Sequence and structural information describing homologous proteins are used to predict correlated substitutions by the Mutual information-based CMAT approach, classify them into spatially close co-evolving pairs, which either form a direct physical contact or interact with the same ligand (e.g. a substrate or a crystallographic water molecule), and long-range correlations, annotate and rank binding sites on the protein surface by the presence of statistically significant co-evolving positions. The results of the visualCMAT are organized for a convenient visual analysis and can be downloaded to a local computer as a content-rich all-in-one PyMol session file with multiple layers of annotation corresponding to bioinformatic, statistical and structural analyses of the predicted co-evolution, or further studied online using the built-in interactive analysis tools. The online interactivity is implemented in HTML5 and therefore neither plugins nor Java are required. The visualCMAT web-server is integrated with the Mustguseal web-server capable of constructing large structure-guided sequence alignments of protein families and superfamilies using all available information about their structures and sequences in public databases. The visualCMAT web-server can be used to understand the relationship between structure and function in proteins, implemented at selecting hotspots and compensatory mutations for rational design and directed evolution experiments to produce novel enzymes with improved properties, and employed at studying the mechanism of selective ligand's binding and allosteric communication between topologically independent sites in protein structures. The web-server is freely available at https

  19. Spot Sampling and Exposure Surrogate Selection as Sources of Bias in Environmental Epidemiology Studies

    Science.gov (United States)

    Spot measurements of chemical biomarkers are often used as quantitative exposure surrogates in environmental epidemiology studies. These measures can be expressed a number of different ways – for example, urinary biomarkers can be expressed in units of concentration (&micr...

  20. Selection of environmental sustainable fiber materials for wind turbine blades - a contra intuitive process?

    DEFF Research Database (Denmark)

    Birkved, Morten; Corona, Andrea; Markussen, Christen Malte

    2013-01-01

    environmental trade-offs over the entire life-span of composite materials, life cycle assessment (LCA) can be applied. In the present case study, four different types of fibers (carbon, glass, flax and carbon/flax mixture) are compared in terms of environmental sustainability and cost. Applying one of the most...... recent life cycle impact assessment methods, it is demonstrated that the environmental sustainability of the mixed carbon/flax fiber based composite material is better than that of the flax fibers alone. This observation may be contra-intuitive, but is mainly caused by the fact that the bio...... impacts in relation to the production of the carbon and glass fibers considerable compared to the impacts resulting from resin production. The ideal fiber solution, in terms of environmental sustainability, is hence the fiber composition having the lowest resin demand and lowest overall energy demand...

  1. Valuation of selected environmental impacts associated with Bonneville Power Administration Resource Program alternatives

    International Nuclear Information System (INIS)

    Englin, J.E.; Gygi, K.F.

    1992-03-01

    This report documents work undertaken by the Pacific Northwest Laboratory (PNL) and its contractors to assist the Bonneville Power Administration (Bonneville) in assessing the potential environmental consequences of new power resources. A major purpose of this effort is to describe and evaluate the techniques available for economic valuation of environmental costs. Another is to provide estimates of the environmental costs associated with specific power resources called for under Bonneville's Resource Programs. Bonneville's efforts to extend valuation techniques to as many impacts as can be reliably assessed represents a substantial advance in the application of state-of-the-art economic techniques to environmental assessments. This economic analysis evaluates effects on human health, wildlife, crops, and visibility impacts associated with air pollution. This report also discusses river recreation (primarily fishing) which may be affected by fluctuations in water levels. 70 refs

  2. STAKEHOLDER OPINION-BASED COMPARISON OF LIFE CYCLE ENVIRONMENTAL IMPACTS OF ELECTRICITY GENERATION IN TURKEY WITH SELECTED EUROPEAN COUNTRIES

    OpenAIRE

    Gorkem Uctug

    2017-01-01

    The life cycle environmental impacts of electricity generation in Turkey were compared to those of Denmark, France, and Poland. The reason for selecting these particular countries for benchmarking was the fact that electricity generation in these countries is dominated mostly by a single source, that is wind, nuclear, and coal, respectively. OpenLCA software and European Life Cycle Database database were used, CML2001 method was employed. The life cycle analysis approach was from cradle to gr...

  3. An evidential reasoning-based AHP approach for the selection of environmentally-friendly designs

    Energy Technology Data Exchange (ETDEWEB)

    NG, C.Y., E-mail: ng.cy@cityu.edu.hk

    2016-11-15

    Due to the stringent environmental regulatory requirements being imposed by cross-national bodies in recent years, manufacturers have to minimize the environmental impact of their products. Among those environmental impact evaluation tools available, Life Cycle Assessment (LCA) is often employed to quantify the product's environmental impact throughout its entire life cycle. However, owing to the requirements of expert knowledge in environmental science and vast effort for data collection in carrying out LCA, as well as the common absence of complete product information during product development processes, there is a need to develop a more suitable tool for product designers. An evidential reasoning-based approach, which aims at providing a fast-track method to perform design alternative evaluations for non-LCA experts, is therefore introduced as a new initiative to deal with the incomplete or uncertain information. The proposed approach also enables decision makers to quantitatively assess the life cycle phases and design alternatives by comparing their potential environmental impacts, thus effectively and efficiently facilitates the identification of greener designs. A case application is carried out to demonstrate the applicability of the proposed approach.

  4. An Environmental and Economic Assessment for Selecting the Optimal Ground Heat Exchanger by Considering the Entering Water Temperature

    Directory of Open Access Journals (Sweden)

    Jimin Kim

    2015-07-01

    Full Text Available In order to solve environmental problems such as global warming and resource depletion in the construction industry, interest in new renewable energy (NRE systems has increased. The ground source heat pump (GSHP system is the most efficient system among NRE systems. However, since the initial investment cost of the GSHP is quite expensive, a feasibility study needs to be conducted from the life-cycle perspective. Meanwhile, the efficiency of GSHP depends most significantly on the entering water temperature (EWT of the ground heat exchanger (GHE. Therefore, this study aims to assess the environmental and economic effects of the use of GHE for selecting the optimal GHE. This study was conducted in three steps: (i establishing the basic information and selecting key factors affecting GHE performances; (ii making possible alternatives of the GHE installation by considering EWT; and (iii using life-cycle assessment and life-cycle cost, as well as comprehensive evaluation of the environmental and economic effects on the GHE. These techniques allow for easy and accurate determination of the optimal design of the GHE from the environmental and economic effects in the early design phase. In future research, a multi-objective decision support model for the GSHP will be developed.

  5. A holistic model for the selection of environmental assessment indicators to assess the impact of industrialization on indigenous health.

    Science.gov (United States)

    Kryzanowski, Julie A; McIntyre, Lynn

    2011-01-01

    Mainstream environmental assessment (EA) methodologies often inadequately address health, social and cultural impacts of concern for Canadian indigenous communities affected by industrialization. Our objective is to present a holistic, culturally-appropriate framework for the selection of indigenous health indicators for baseline health assessment, impact prediction, or monitoring of impacts over time. We used a critical population health approach to explore the determinants of health and health inequities in indigenous communities and conceptualize the pathways by which industrialization affects these determinants. We integrated and extended key elements from three indigenous health frameworks into a new holistic model for the selection of indigenous EA indicators. The holistic model conceptualizes individual and community determinants of health within external social, economic and political contexts and thus provides a comprehensive framework for selecting indicators of indigenous health. Indigenous health is the product of interactions among multiple determinants of health and contexts. Potential applications are discussed using case study examples involving indigenous communities affected by industrialization. Industrialization can worsen indigenous health inequities by perpetuating the health, social and cultural impacts of historic environmental dispossession. To mitigate impacts, EA should explicitly recognize linkages between environmental dispossession and the determinants of health and health inequities and meaningfully involve indigenous communities in the process.

  6. An Analytic Network Process approach for the environmental aspect selection problem — A case study for a hand blender

    Energy Technology Data Exchange (ETDEWEB)

    Bereketli Zafeirakopoulos, Ilke, E-mail: ibereketli@gsu.edu.tr; Erol Genevois, Mujde, E-mail: merol@gsu.edu.tr

    2015-09-15

    Life Cycle Assessment is a tool to assess, in a systematic way, the environmental aspects and its potential environmental impacts and resources used throughout a product's life cycle. It is widely accepted and considered as one of the most powerful tools to support decision-making processes used in ecodesign and sustainable production in order to learn about the most problematic parts and life cycle phases of a product and to have a projection for future improvements. However, since Life Cycle Assessment is a cost and time intensive method, companies do not intend to carry out a full version of it, except for large corporate ones. Especially for small and medium sized enterprises, which do not have enough budget for and knowledge on sustainable production and ecodesign approaches, focusing only on the most important possible environmental aspect is unavoidable. In this direction, finding the right environmental aspect to work on is crucial for the companies. In this study, a multi-criteria decision-making methodology, Analytic Network Process is proposed to select the most relevant environmental aspect. The proposed methodology aims at providing a simplified environmental assessment to producers. It is applied for a hand blender, which is a member of the Electrical and Electronic Equipment family. The decision criteria for the environmental aspects and relations of dependence are defined. The evaluation is made by the Analytic Network Process in order to create a realistic approach to inter-dependencies among the criteria. The results are computed via the Super Decisions software. Finally, it is observed that the procedure is completed in less time, with less data, with less cost and in a less subjective way than conventional approaches. - Highlights: • We present a simplified environmental assessment methodology to support LCA. • ANP is proposed to select the most relevant environmental aspect. • ANP deals well with the interdependencies between aspects

  7. An Analytic Network Process approach for the environmental aspect selection problem — A case study for a hand blender

    International Nuclear Information System (INIS)

    Bereketli Zafeirakopoulos, Ilke; Erol Genevois, Mujde

    2015-01-01

    Life Cycle Assessment is a tool to assess, in a systematic way, the environmental aspects and its potential environmental impacts and resources used throughout a product's life cycle. It is widely accepted and considered as one of the most powerful tools to support decision-making processes used in ecodesign and sustainable production in order to learn about the most problematic parts and life cycle phases of a product and to have a projection for future improvements. However, since Life Cycle Assessment is a cost and time intensive method, companies do not intend to carry out a full version of it, except for large corporate ones. Especially for small and medium sized enterprises, which do not have enough budget for and knowledge on sustainable production and ecodesign approaches, focusing only on the most important possible environmental aspect is unavoidable. In this direction, finding the right environmental aspect to work on is crucial for the companies. In this study, a multi-criteria decision-making methodology, Analytic Network Process is proposed to select the most relevant environmental aspect. The proposed methodology aims at providing a simplified environmental assessment to producers. It is applied for a hand blender, which is a member of the Electrical and Electronic Equipment family. The decision criteria for the environmental aspects and relations of dependence are defined. The evaluation is made by the Analytic Network Process in order to create a realistic approach to inter-dependencies among the criteria. The results are computed via the Super Decisions software. Finally, it is observed that the procedure is completed in less time, with less data, with less cost and in a less subjective way than conventional approaches. - Highlights: • We present a simplified environmental assessment methodology to support LCA. • ANP is proposed to select the most relevant environmental aspect. • ANP deals well with the interdependencies between aspects

  8. A novel approach to assessing environmental disturbance based on habitat selection by zebra fish as a model organism.

    Science.gov (United States)

    Araújo, Cristiano V M; Griffith, Daniel M; Vera-Vera, Victoria; Jentzsch, Paul Vargas; Cervera, Laura; Nieto-Ariza, Beatriz; Salvatierra, David; Erazo, Santiago; Jaramillo, Rusbel; Ramos, Luis A; Moreira-Santos, Matilde; Ribeiro, Rui

    2018-04-01

    Aquatic ecotoxicity assays used to assess ecological risk assume that organisms living in a contaminated habitat are forcedly exposed to the contamination. This assumption neglects the ability of organisms to detect and avoid contamination by moving towards less disturbed habitats, as long as connectivity exists. In fluvial systems, many environmental parameters vary spatially and thus condition organisms' habitat selection. We assessed the preference of zebra fish (Danio rerio) when exposed to water samples from two western Ecuadorian rivers with apparently distinct disturbance levels: Pescadillo River (highly disturbed) and Oro River (moderately disturbed). Using a non-forced exposure system in which water samples from each river were arranged according to their spatial sequence in the field and connected to allow individuals to move freely among samples, we assayed habitat selection by D. rerio to assess environmental disturbance in the two rivers. Fish exposed to Pescadillo River samples preferred downstream samples near the confluence zone with the Oro River. Fish exposed to Oro River samples preferred upstream waters. When exposed to samples from both rivers simultaneously, fish exhibited the same pattern of habitat selection by preferring the Oro River samples. Given that the rivers are connected, preference for the Oro River enabled us to predict a depression in fish populations in the Pescadillo River. Although these findings indicate higher disturbance levels in the Pescadillo River, none of the physical-chemical variables measured was significantly correlated with the preference pattern towards the Oro River. Non-linear spatial patterns of habitat preference suggest that other environmental parameters like urban or agricultural contaminants play an important role in the model organism's habitat selection in these rivers. The non-forced exposure system represents a habitat selection-based approach that can serve as a valuable tool to unravel the factors

  9. Portable, universal, and visual ion sensing platform based on the light emitting diode-based self-referencing-ion selective field-effect transistor.

    Science.gov (United States)

    Zhang, Xiaowei; Han, Yanchao; Li, Jing; Zhang, Libing; Jia, Xiaofang; Wang, Erkang

    2014-02-04

    In this work, a novel and universal ion sensing platform was presented, which enables the visual detection of various ions with high sensitivity and selectivity. Coaxial potential signals (millivolt-scale) of the sample from the self-referencing (SR) ion selective chip can be transferred into the ad620-based amplifier with an output of volt-scale potentials. The amplified voltage is high enough to drive a light emitting diode (LED), which can be used as an amplifier and indicator to report the sample information. With this double amplification device (light emitting diode-based self-referencing-ion selective field-effect transistor, LED-SR-ISFET), a tiny change of the sample concentration can be observed with a distinguishable variation of LED brightness by visual inspection. This LED-based luminescent platform provided a facile, low-cost, and rapid sensing strategy without the need of additional expensive chemiluminescence reagent and instruments. Moreover, the SR mode also endows this device excellent stability and reliability. With this innovative design, sensitive determination of K(+), H(+), and Cl(-) by the naked eye was achieved. It should also be noticed that this sensing strategy can easily be extended to other ions (or molecules) by simply integrating the corresponding ion (or molecule) selective electrode.

  10. Selection for protection from insolation results in the visual isolation of Yellow-eyed Penguin Megadyptes antipodes nests

    CSIR Research Space (South Africa)

    Clark, RD

    2015-06-01

    Full Text Available The concealed and widely dispersed nests of the rare and endangered Yellow-eyed Penguin Megadyptes antipodes, or “hoiho”, have been considered to reflect an essential requirement for the visual isolation of nest sites from conspecifics. However...

  11. Observation of Depictive Versus Tracing Gestures Selectively Aids Verbal Versus Visual-Spatial Learning in Primary School Children

    NARCIS (Netherlands)

    van Wermeskerken, Margot; Fijan, Nathalie; Eielts, Charly; Pouw, Wim T. J. L.

    2016-01-01

    Previous research has established that gesture observation aids learning in children. The current study examined whether observation of gestures (i.e. depictive and tracing gestures) differentially affected verbal and visual-spatial retention when learning a route and its street names. Specifically,

  12. Selection for uniformity in livestock by exploiting genetic heterogeneity of environmental variance

    NARCIS (Netherlands)

    Mulder, H.A.; Bijma, P.; Hill, W.G.

    2008-01-01

    In some situations, it is worthwhile to change not only the mean, but also the variability of traits by selection. Genetic variation in residual variance may be utilised to improve uniformity in livestock populations by selection. The objective was to investigate the effects of genetic parameters,

  13. Effects of environmental changes on natural selection active on human polygenic traits.

    Science.gov (United States)

    Ulizzi, L

    1993-06-01

    During the last century, industrialized countries experienced such an improvement in socioeconomic conditions and in sanitation that it is likely that the selective forces active on human metric traits have been modified. Perinatal mortality as a function of birth weight is one of the clearest examples of natural selection in humans. Here, trends over time of stabilizing and directional selection associated with birth weight have been analyzed in Japan from 1969 to 1989. The population of newborns has been subdivided according to gestational age, which is one of the main covariates of birth weight. The results show that in full-term babies both stabilizing and directional selection are coming to an end, whereas in babies born after 8 months of gestation these selective forces are still active, even if at much lower levels than in the past. The peculiar results found in the 7-month-gestation population are probably due to grossly abnormal cases of immaturity.

  14. Comparative environmental impact and efficiency assessment of selected hydrogen production methods

    Energy Technology Data Exchange (ETDEWEB)

    Ozbilen, Ahmet, E-mail: Ahmet.Ozbilen@uoit.ca; Dincer, Ibrahim, E-mail: Ibrahim.Dincer@uoit.ca; Rosen, Marc A., E-mail: Marc.Rosen@uoit.ca

    2013-09-15

    The environmental impacts of various hydrogen production processes are evaluated and compared, considering several energy sources and using life cycle analysis. The results indicate that hydrogen produced by thermochemical water decomposition cycles are more environmentally benign options compared to conventional steam reforming of natural gas. The nuclear based four-step Cu–Cl cycle has the lowest global warming potential (0.559 kg CO{sub 2}-eq per kg hydrogen production), mainly because it requires the lowest quantity of energy of the considered processes. The acidification potential results show that biomass gasification has the highest impact on environment, while wind based electrolysis has the lowest. The relation is also investigated between efficiency and environmental impacts. -- Highlights: • Environmental performance of nuclear-based hydrogen production is investigated. • The GWP and AP results are compared with various hydrogen production processes. • Nuclear based 4-step Cu–Cl cycle is found to be an environmentally benign process. • Wind-based electrolysis has the lowest AP value.

  15. Multi-scale Visualization of Remote Sensing and Topographic Data of the Amazon Rain Forest for Environmental Monitoring of the Petroleum Industry.

    Science.gov (United States)

    Fonseca, L.; Miranda, F. P.; Beisl, C. H.; Souza-Fonseca, J.

    2002-12-01

    PETROBRAS (the Brazilian national oil company) built a pipeline to transport crude oil from the Urucu River region to a terminal in the vicinities of Coari, a city located in the right margin of the Solimoes River. The oil is then shipped by tankers to another terminal in Manaus, capital city of the Amazonas state. At the city of Coari, changes in water level between dry and wet seasons reach up to 14 meters. This strong seasonal character of the Amazonian climate gives rise to four distinct scenarios in the annual hydrological cycle: low water, high water, receding water, and rising water. These scenarios constitute the main reference for the definition of oil spill response planning in the region, since flooded forests and flooded vegetation are the most sensitive fluvial environments to oil spills. This study focuses on improving information about oil spill environmental sensitivity in Western Amazon by using 3D visualization techniques to help the analysis and interpretation of remote sensing and digital topographic data, as follows: (a) 1995 low flood and 1996 high flood JERS-1 SAR mosaics, band LHH, 100m pixel; (b) 2000 low flood and 2001 high flood RADARSAT-1 W1 images, band CHH, 30m pixel; (c) 2002 high flood airborne SAR images from the SIVAM project (System for Surveillance of the Amazon), band LHH, 3m pixel and band XHH, 6m pixel; (d) GTOPO30 digital elevation model, 30' resolution; (e) Digital elevation model derived from topographic information acquired during seismic surveys, 25m resolution; (f) panoramic views obtained from low altitude helicopter flights. The methodology applied includes image processing, cartographic conversion and generation of value-added product using 3D visualization. A semivariogram textural classification was applied to the SAR images in order to identify areas of flooded forest and flooded vegetation. The digital elevation models were color shaded to highlight subtle topographic features. Both datasets were then converted to

  16. Sensitive and selective culture medium for detection of environmental Clostridium difficile isolates without requirement for anaerobic culture conditions.

    Science.gov (United States)

    Cadnum, Jennifer L; Hurless, Kelly N; Deshpande, Abhishek; Nerandzic, Michelle M; Kundrapu, Sirisha; Donskey, Curtis J

    2014-09-01

    Effective and easy-to-use methods for detecting Clostridium difficile spore contamination would be useful for identifying environmental reservoirs and monitoring the effectiveness of room disinfection. Culture-based detection methods are sensitive for detecting C. difficile, but their utility is limited due to the requirement of anaerobic culture conditions and microbiological expertise. We developed a low-cost selective broth medium containing thioglycolic acid and l-cystine, termed C. difficile brucella broth with thioglycolic acid and l-cystine (CDBB-TC), for the detection of C. difficile from environmental specimens under aerobic culture conditions. The sensitivity and specificity of CDBB-TC (under aerobic culture conditions) were compared to those of CDBB (under anaerobic culture conditions) for the recovery of C. difficile from swabs collected from hospital room surfaces. CDBB-TC was significantly more sensitive than CDBB for recovering environmental C. difficile (36/41 [88%] versus 21/41 [51%], respectively; P = 0.006). C. difficile latex agglutination, an enzyme immunoassay for toxins A and B or glutamate dehydrogenase, and a PCR for toxin B genes were all effective as confirmatory tests. For 477 total environmental cultures, the specificity of CDBB-TC versus that of CDBB based upon false-positive yellow-color development of the medium without recovery of C. difficile was 100% (0 false-positive results) versus 96% (18 false-positive results), respectively. False-positive cultures for CDBB were attributable to the growth of anaerobic non-C. difficile organisms that did not grow in CDBB-TC. Our results suggest that CDBB-TC provides a sensitive and selective medium for the recovery of C. difficile organisms from environmental samples, without the need for anaerobic culture conditions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. ENVIRONMENTAL CONTAMINANTS AND POTENTIAL HUMAN RISK ASSOCIATED WITH SELECTED BOTANICAL DIETARY SUPPLEMENTS

    Science.gov (United States)

    Botanical dietary supplements have a long history of use in Europe and China and they are becoming increasingly popular in the United States. However, little data is available regarding environmental contaminants in botanical dietary supplements and the risk posed to those ingest...

  18. Selecting among five common modelling approaches for integrated environmental assessment and management

    NARCIS (Netherlands)

    Kelly, Rebecca A.; Jakeman, Anthony J.; Barreteau, Olivier; Borsuk, Mark E.; El-Sawah, Sondoss; Hamilton, Serena H.; Henriksen, Hans Jorgen; Kuikka, Sakari; Maier, Holger R.; Rizzoli, Andrea Emilio; van Delden, H.; Voinov, A.

    2013-01-01

    The design and implementation of effective environmental policies need to be informed by a holistic understanding of the system processes (biophysical, social and economic), their complex interactions, and how they respond to various changes. Models, integrating different system processes into a

  19. Performance assessment of select covers and disposal cell compliance with EPA [Environmental Protection Agency] groundwater standards

    International Nuclear Information System (INIS)

    1989-06-01

    This document describes the technical approach to the assessment of the performance of a full component topslope cover, three sideslope covers, and hence the way in which a Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell complies with the US Environmental Protection Agency (EPA) groundwater protection standards. 4 refs

  20. Environmental Management and Education and Training Provision in Selected EU Countries

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Madsen, Henning

    Particular attention has been given at the UN level and in the EU environmental policy to the importance of the educational requirements which follow from the implementation of cleaner and less harmful practices. Therefore, training and education have long been recognised as essential ingredients...

  1. Changing Preschool Children's Attitudes into Behavior towards Selected Environmental Issues: An Action Research Study

    Science.gov (United States)

    Ertürk Kara, Gözde; Aydos, E. Hande; Aydin, Özge

    2015-01-01

    The purpose of this study is to provide the transform of attitudes into behavior of 60-72 month of age children continued early childhood education toward environmental issues. Collaborative action research method of qualitative design was used. The whole participants of the study were 60-72 months of age children who were attending in an early…

  2. Clean and Selective Catalytic C-H alkylation of Alkenes with Environmental friendly Alcohols

    KAUST Repository

    Poater, Albert; Vummaleti, Sai V. C.; Polo, Alfonso; Cavallo, Luigi

    2016-01-01

    Bearing the alkylation of alkene substrates using alcohol as solvent, catalysed by the cationic Ru-based catalyst [(C6H6)(PCy3)(CO)RuH]+, DFT calculations have been carried out to get mechanistic insights of such an environmental friendly reaction

  3. Column liquid chromatography- mass spectrometry: selected techniques in environmental applications for polar pesticides and related compounds.

    NARCIS (Netherlands)

    Slobodnik, J.; van Baar, B.L.M.; Brinkman, U.A.T.

    1995-01-01

    A review covering the field of environmental applications of liquid chromatography-mass spectrometry (LC-MS) is presented. Recent developments and advances are discussed with emphasis on the presently popular thermospray, particle beam and atmospheric pressure ionisation interfaces. Each interface

  4. Harnessing Visual Media in Environmental Education: Increasing Knowledge of Orangutan Conservation Issues and Facilitating Sustainable Behaviour through Video Presentations

    Science.gov (United States)

    Pearson, Elissa; Dorrian, Jillian; Litchfield, Carla

    2011-01-01

    Many animals are currently facing extinction. Conservation education which highlights the impacts of our behaviour on other species survival is crucial. This study provides evidence for the use of visual media to increase knowledge, attitudes and conservation behaviours regarding the highly endangered orangutan. University students (n = 126) were…

  5. Modeling the Time-Course of Responses for the Border Ownership Selectivity Based on the Integration of Feedforward Signals and Visual Cortical Interactions.

    Science.gov (United States)

    Wagatsuma, Nobuhiko; Sakai, Ko

    2016-01-01

    Border ownership (BO) indicates which side of a contour owns a border, and it plays a fundamental role in figure-ground segregation. The majority of neurons in V2 and V4 areas of monkeys exhibit BO selectivity. A physiological work reported that the responses of BO-selective cells show a rapid transition when a presented square is flipped along its classical receptive field (CRF) so that the opposite BO is presented, whereas the transition is significantly slower when a square with a clear BO is replaced by an ambiguous edge, e.g., when the square is enlarged greatly. The rapid transition seemed to reflect the influence of feedforward processing on BO selectivity. Herein, we investigated the role of feedforward signals and cortical interactions for time-courses in BO-selective cells by modeling a visual cortical network comprising V1, V2, and posterior parietal (PP) modules. In our computational model, the recurrent pathways among these modules gradually established the visual progress and the BO assignments. Feedforward inputs mainly determined the activities of these modules. Surrounding suppression/facilitation of early-level areas modulates the activities of V2 cells to provide BO signals. Weak feedback signals from the PP module enhanced the contrast gain extracted in V1, which underlies the attentional modulation of BO signals. Model simulations exhibited time-courses depending on the BO ambiguity, which were caused by the integration delay of V1 and V2 cells and the local inhibition therein given the difference in input stimulus. However, our model did not fully explain the characteristics of crucially slow transition: the responses of BO-selective physiological cells indicated the persistent activation several times longer than that of our model after the replacement with the ambiguous edge. Furthermore, the time-course of BO-selective model cells replicated the attentional modulation of response time in human psychophysical experiments. These attentional

  6. Modeling the Time-Course of Responses for the Border Ownership Selectivity Based on the Integration of Feedforward Signals and Visual Cortical Interactions

    Science.gov (United States)

    Wagatsuma, Nobuhiko; Sakai, Ko

    2017-01-01

    Border ownership (BO) indicates which side of a contour owns a border, and it plays a fundamental role in figure-ground segregation. The majority of neurons in V2 and V4 areas of monkeys exhibit BO selectivity. A physiological work reported that the responses of BO-selective cells show a rapid transition when a presented square is flipped along its classical receptive field (CRF) so that the opposite BO is presented, whereas the transition is significantly slower when a square with a clear BO is replaced by an ambiguous edge, e.g., when the square is enlarged greatly. The rapid transition seemed to reflect the influence of feedforward processing on BO selectivity. Herein, we investigated the role of feedforward signals and cortical interactions for time-courses in BO-selective cells by modeling a visual cortical network comprising V1, V2, and posterior parietal (PP) modules. In our computational model, the recurrent pathways among these modules gradually established the visual progress and the BO assignments. Feedforward inputs mainly determined the activities of these modules. Surrounding suppression/facilitation of early-level areas modulates the activities of V2 cells to provide BO signals. Weak feedback signals from the PP module enhanced the contrast gain extracted in V1, which underlies the attentional modulation of BO signals. Model simulations exhibited time-courses depending on the BO ambiguity, which were caused by the integration delay of V1 and V2 cells and the local inhibition therein given the difference in input stimulus. However, our model did not fully explain the characteristics of crucially slow transition: the responses of BO-selective physiological cells indicated the persistent activation several times longer than that of our model after the replacement with the ambiguous edge. Furthermore, the time-course of BO-selective model cells replicated the attentional modulation of response time in human psychophysical experiments. These attentional

  7. Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of "Green" Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex.

    Science.gov (United States)

    Rauscher, Franziska G; Plant, Gordon T; James-Galton, Merle; Barbur, John L

    2011-01-01

    Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d'Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength ("red") and middle wavelength ("green") regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient's results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both "red/green" and "yellow/blue" directions in colour space, the subject's lower left quadrant showed a marked asymmetry in "red/green" thresholds with the greatest loss of sen