88 research outputs found
Neural Mechanisms of Transsaccadic Integration of Visual Features
This thesis explores the neural mechanisms of transsaccadic integration of visual features. In the study, I investigated the cortical correlates of transsaccadic integration of object orientation in multiple reference frames. In a functional MRI adaptation (fMRIa) paradigm, participants viewed sets of two orientation stimuli in each trial and were asked to indicate if the orientations were the same (Repeat condition) or different (Novel condition). Stimuli were presented in one of three spatial conditions: 1) space-fixed, 2) retina-fixed and 3) frame-independent. Results indicate that, in addition to common activation in frontal motor cortical regions in all three spatial conditions, parietal and occipitotemporal regions are active in the space-fixed condition, parietofrontal regions are active in the retina-fixed condition, and parietofrontal and occipitotemporal regions are active in the frame-independent condition. In conclusion, these results indicate that transsaccadic integration involves differential activation of cortical areas, depending on the frame of reference
CONCEPT OF SUSTAINABILITY – A LOGICAL APPROACH
The paper aims to achieve a definition of the concept of sustainability and of sustainable system from a logical perspective. In this respect, it introduces and defines (through the sufficiency predicates) the concept of logically vivid system and, on this basis, are discussed a logical concept of sustainability, respectively of a sustainable system in general are discussed and built up. Sustainability is considered in light of identity preservation of the systems, as a static anchor, on one hand, and of the concept of automatic stabilizers as a dynamic anchor on the other side. Finally, the two sufficiency conditions for a logically vivid system be sustainable are identified: the presence of hyper-cycles, respectively the absence of positive feed-back
Как обеспечить постоянную концентрацию примеси по высоте слитка
On the basis of segregation study in crystal growth from a thin melt layer in presence of the submerged heater the possibility to obtain the uniform material along the height of the ingot is shown. Numerically in modeling of solidification of 200 mm in a diameter Sb doped Ge the accurate solution with account for convection was found in the central part of the domain to coincide with the one dimension problem for the melt layer beginning from 40 mm. Condition to neglect with convection in mass transfer are to be more rigorous: the melt layer should be less than 20 mm. In this case, one may use Tiller’s equation obtained to calculate the axial impurity distribution in approach of the diffusion-control segregation. The analysis of attempts to describe experimental data of crystal growth by use of the simplified equations has shown their validity in case of account for actual crystal growth rate or change in the melt layer thickness during the run, as in expression find by Marchenko et al. The above said makes it possible for to describe analytically the axial distribution of impurity in the ingot, particularly, for B and P in silicon and to recommend the amount of its concentration over the height. The uniform material in the very end of the solidification process of the rest portion of the ingot can be obtained by the variation of the growth rate due to change in the cooling rate with time.На основе исследования сегрегации при выращивании германия и кремния из тонкого слоя расплава с использованием техники погруженного нагревателя показана возможность получения однородных по высоте кристаллов. Численно при моделировании кристаллизации легированного сурьмой германии диаметром 200 мм найдено, что, начиная с толщины слоя расплава в 40 мм, точное решение с учетом конвекции совпадает в центральной части расчетной области с задачей теплообмена в одномерной постановке. Условия, при которых можно в массопереносе пренебречь конвекцией, более жесткие: слой расплава должен быть менее 20 мм. В этом случае можно использовать соотношение Тиллера для расчета продольного распределения примеси в условиях преимущественно диффузионного характера переноса. Анализ попыток описания экспериментальных данных по росту кристаллов с помощью упрощенных формул показал, что они дают приемлемые результаты лишь при условии, если учитывается реальная скорость роста или изменение толщины слоя расплава в процессе кристаллизации, как в формуле Марченко с соавторами. Сказанное позволяет аналитически описать продольное распределение примеси в слитке, в частности для B и P в кремнии, и рекомендовать величину дополнительного легирования зоны расплава под нагревателем, чтобы обеспечить постоянную ее концентрацию по высоте кристалла. Однородный материал при затвердевании остаточного слоя в самом конце слитка может быть получен за счет вариации скорости роста при изменении во времени темпа его охлаждения
Cortical Mechanisms for Transsaccadic Perception of Visual Object Features
The cortical correlates for transsaccadic perception (i.e., the ability to perceive, maintain, and update information across rapid eye movements, or saccades; Irwin, 1991) have been little investigated. Previously, Dunkley et al. (2016) found evidence of transsaccadic updating of object orientation in specific intraparietal (i.e., supramarginal gyrus, SMG) and extrastriate occipital (putative V4) regions. Based on these findings, I hypothesized that transsaccadic perception may rely on a single cortical mechanism. In this dissertation, I first investigated whether activation in the previous regions would generalize to another modality (i.e., motor/grasping) for the same feature (orientation) change, using a functional magnetic resonance imaging (fMRI) event-related paradigm that involved participants grasping a three-dimensional rotatable object for either fixations or saccades. The findings from this experiment further support the role of SMG in transsaccadic updating of object orientation, and provide a novel view of traditional reach/grasp-related regions in their ability to update grasp-related signals across saccades. In the second experiment, I investigated whether parietal cortex (e.g., SMG) plays a general role in the transsaccadic perception of other low-level object features, such as spatial frequency. The results point to the engagement of a different, posteromedial extrastriate (i.e., cuneus) region for transsaccadic perception of spatial frequency changes. This indirect assessment of transsaccadic interactions for different object features suggests that feature sensitive mechanisms may exist. In the third experiment, I tested the cortical correlates directly for two object features: orientation and shape. In this experiment, only posteromedial extrastriate cortex was associated with transsaccadic feature updating in the feature discrimination task, as it showed both saccade and feature modulations. Overall, the results of these three neuroimaging studies suggest that transsaccadic perception may be brought about by more than a single, general mechanism and, instead, through multiple, feature-dependent cortical mechanisms. Specifically, the saccade system communicates with inferior parietal cortex for transsaccadic judgements of orientation in an identified object, whereas as a medial occipital system is engaged for feature judgements related to object identity
Talking about Relations:Factors Influencing the Production of Relational Descriptions
In a production experiment (Experiment 1) and an acceptability rating one (Experiment 2), we assessed two factors, spatial position and salience, which may influence the production of relational descriptions (such as the ball between the man and the drawer). In Experiment 1, speakers were asked to refer unambiguously to a target object (a ball). In Experiment 1a, we addressed the role of spatial position, more specifically if speakers mention the entity positioned leftmost in the scene as (first) relatum. The results showed a preference to start with the left entity, however, only as a trend, which leaves room for other factors that could influence spatial reference. Thus, in the following studies, we varied salience systematically, by making one of the relatum candidates animate (Experiment 1b), and by adding attention capture cues, first subliminally by priming one relatum candidate with a flash (Experiment 1c), then explicitly by using salient colors for objects (Experiment 1d). Results indicate that spatial position played a dominant role. Entities on the left were mentioned more often as (first) relatum than those on the right (Experiment 1a, 1b, 1c, 1d). Animacy affected reference production in one out of three studies (in Experiment 1d). When salience was manipulated by priming visual attention or by using salient colors, there were no significant effects (Experiment 1c, 1d). In the acceptability rating study (Experiment 2), participants expressed their preference for specific relata, by ranking descriptions on the basis of how good they thought the descriptions fitted the scene. Results show that participants preferred most the description that had an animate entity as the first mentioned relatum. The relevance of these results for models of reference production is discussed
Thinking-While-Moving Exercises May Improve Cognition in Elderly with Mild Cognitive Deficits: A Proof-of-Principle Study
Background: Noninvasive interventions to aid healthy cognitive aging are considered an important healthcare priority. Traditional approaches typically focus on cognitive training or aerobic exercise training. In the current study, we investigate the effect of exercises that directly combine cognitive and motor functions on visuomotor skills and general cognition in elderly with various degrees of cognitive deficits. Subjects and Methods: A total of 37 elderly, divided into four groups based on their level of cognition, completed a 16-week cognitive-motor training program. The weekly training sessions consisted of playing a videogame requiring goal-directed hand movements on a computer tablet for 30 minutes. Before and after the training program, all participants completed a test battery to establish their level of cognition and visuomotor skills. Results: We observed an overall change in visuomotor behavior in all groups, as participants completed the tasks faster but less accurately. More importantly, we observed a significant improvement in measures of overall cognition in the subaverage cognition group and the mild-to-moderate cognitive deficits group. Conclusion: Our findings indicate that (1) cognitive-motor exercises induce improved test scores, which is most prominent in elderly with only mild cognitive deficits, and (2) cognitive-motor exercises induce altered visuomotor behavior and slight improvements in measures of general cognition
Gas-phase and particulate products from the atmospheric degradation of an isoxazole fungicide
[EN] The isoxazole structure is present in several pesticides. However, there is a lack of information about its
degradation products after the release to the atmosphere. The main atmospheric reactions of hymexazol
(5-methylisoxazol-3-ol), selected as representative model, were investigated at a large outdoor simulation
chamber. The predominant products of atmospheric degradations were gaseous nitrogen derivates
(nitric acid, nitrogen dioxide, nitrogen oxide, nitrous acid, and peroxyacetylnitrate), ozone, and small
oxygenated compounds (formic acid, formaldehyde, and methylglyoxal). The aerosol yields were lower
than 5%, and an OH rate-dependence was observed in the nucleation, particle growth, and size distribution.
Also, the chemical composition of minor multi-oxygenated products was studied for OH-photooxidations.
More than 20 products were detected in the gas or particulate phase. The most abundant
were heterocyclic cleavage products with C4-chain and oxygenated moieties at positions 1 and 3, such
as 3,4-dioxobutanoic acid, 3-oxobutanoic acid, and 3-oxobutanal. The suggested reaction pathway is
the opening of heterocycle ring by the cleavage of N O bond and C N bond, releasing nitrogen oxides.The authors wish to thank the EUPHORE staff and J.T.B. The authors wish to acknowledge Ministerio de Ciencia y Tecnologia for IMPESTAT (CGL2010-18474/CLI) and the European Community's Seventh Framework Program under the Grant agreement no. 228335 (Eurochamp2). The Fundacion CEAM is partly supported by Generalitat Valenciana, and the projects GRACCIE (Consolider-Ingenio 2010) and FEEDBACKS (Prometeo - Generalitat Valenciana). EUPHORE instrumentation is partly funded by the Spanish Ministry of Science and Innovation, through INNPLANTA Project: PCT-440000-2010-003.Tortajada-Genaro, LA.; Borrás García, EM.; Muñoz, A. (2013). Gas-phase and particulate products from the atmospheric degradation of an isoxazole fungicide. Chemosphere. 92(8):1035-1041. https://doi.org/10.1016/j.chemosphere.2013.03.041S1035104192
Questions of choice of sport in young childrens
Title: Questions of choice of sport in young childrens Objectives: The main aim of this thesis is to find out what possibilities there are for children of an younger school age to be introduced to sport and to find out what choice of sport programmes they have. Also, to find out how children and their parents choose sport activities, sport clubs and sport sections. Methods: During my work with children, I applied method of group research, which is part of methodical quality research. Another way how I gathered information from parents with children of an younger school age was by method of quantity research. I've used a questionnaire and also part of my study to find out what are the possibilities how to introduce children to sport I used desk research method. Therefore, during my practise I used combination of both methods- quality and quantity research. Results: I came to a conclusion, that children of an younger school age are most likely to spend their free time outdoors and practise one of many outdoor activities. Most children have an access to these type of activities near their homes and use public parks.With regret I have to point out that knowledge and deeper understanding of wide range of sport sections and sport disciplines are at the beginning of period of children at an younger school..
PARTICULARITIES AND THREATS ON THE BIODIVERSITY FROM CROATIA
Because it has a specific geographic position and it’s situated at the crossroads of several bio-geographical regions and as a result of its ecological characteristics, the climate and geo-morphological conditions, Croatia is one of the wealthiest countries from Europe concerning the biodiversity. The great variety of the territory, maritime and underground habitats has determined the existence of numerous species and subspecies, including a significant number of endemic species. Although the climate of Croatia has a great value, many of its components are threatened. The most important threats of wild species are losing the habitats and the degradation. Because of its shape and its position in Europe, Croatia has very rich landscape diversity. Croatia contains significant populations of many species that are threatened at the European level. These are connected to preserved large areas of their habitats. Vast mountain beech and fir forests are rich in bear, wolf and lynx populations. Large wetland complexes with alluvial forests are important breeding, the migration and wintering sites for European water birds and for wetland birds nesting in forests. The wealth of marine biodiversity, in combination with the immense diversity of islands and cliffs with endemic life forms, gives the Croatian coastal area international significance.Natural protected area, Biodiversity, National park, Habitat, Endemic species.
Mamabloggers and fans raction on their cooperation with companies
In this diploma thesis I deal with the topic of blogs. My main goal was to introduce the part of blogs called mommyblogs and to define it as a separate category in the theoretical background chapter. In the practical part, I decided to use quantitative methods of data collection through a questionnaire survey. The survey was aimed at both mommy bloggers and their readers. I supplemented the questionnaires with depth interviews with selected mommy bloggers. Which helped me to obtain even more detailed data, which enriched the data obtained from both questionnaires. I found out what motivates mommy bloggers to blog, but also what their attitude is towards cooperation with companies and how they select and label collaborations. Have they ever felt exploited either by companies or by social media? The respondents also touched on the topic of ethics and responsibility - either regarding the placement of photos of children on social media or regarding products whose promotion is bound by regulations. I tried to find out the ability of the readers to recognize advertisements on blogs and social networks of mommy bloggers. And also how the advertising message of mommy bloggers affects their readers. This thesis focuses only on bloggers from the Czech Republic
- …