Academic literature on the topic 'Stimuli de ler ordre'

We hypothesized that gravitational stimuli elicit cardiovascular responses in the following order with gravitational stress equalized at the level of the feet, from lowest to highest response: short-(SAC) and long-arm centrifugation (LAC), tilt, and lower body negative pressure (LBNP). Up to 15 healthy subjects underwent graded application of the four stimuli. Laser-Doppler flowmetry measured regional skin blood flow. At 0.6 Gz (60 mmHg LBNP), tilt and LBNP similarly reduced leg skin blood flow to ∼36% of supine baseline levels. Flow increased back toward baseline levels at 80–100 mmHg LBNP yet remained stable during 0.8–1.0 Gz tilt. Centrifugation usually produced less leg vasoconstriction than tilt or LBNP. Surprisingly, SAC and LAC did not differ significantly. Thigh responses were less definitive than leg responses. No gravitational vasoconstriction occurred in the neck. All conditions except SAC increased heart rate, according to our hypothesized order. LBNP may be a more effective and practical means of simulating cardiovascular effects of gravity than centrifugation.

Localizing pain not only requires a simple somatotopic representation of the body, but also knowledge about the limb position (i.e., proprioception), and a visual localization of the pain source in external space. Therefore, nociceptive events are remapped into a multimodal representation of the body and the space nearby (i.e., a peripersonal schema of the body). We investigated the influence of visual cues presented either in peripersonal, or in extrapersonal space on the localization of nociceptive stimuli in a temporal order judgement (TOJ) task. 24 psychology students made TOJs concerning which of two nociceptive stimuli (one applied to each hand) had been presented first (or last). A spatially non-predictive visual cue (i.e., lighting of a LED) preceded (80 ms) the nociceptive stimuli. This cue was presented randomly either on the hand of the participant (in peripersonal space), or 70 cm in front of the hand (in extrapersonal space), and either on the left or on the right side of space. Biases in spatial attention are reflected by the point of subjective simultaneity (PSS). The results revealed that TOJs were more biased towards the visual cue in peripersonal space in comparison with the visual cue in extrapersonal space. This study provides evidence for the crossmodal integration of visual and nociceptive stimuli in a peripersonal schema of the body. Future research with this paradigm will explore crossmodal attention deficits in chronic pain populations.

In visual search, some fixations are made between stimuli on empty regions, commonly referred to as “centre-of-gravity” fixations (henceforth: COG fixations). Previous studies have shown that observers with task expertise show more COG fixations than novices. This led to the view that COG fixations reflect simultaneous encoding of multiple stimuli, allowing more efficient processing of task-related items. The present study tested whether COG fixations also aid performance in visual search tasks with unfamiliar and abstract stimuli. Moreover, to provide evidence for the multiple-item processing view, we analysed the effects of COG fixations on the number and dwell times of stimulus fixations. The results showed that (1) search efficiency increased with increasing COG fixations even in search for unfamiliar stimuli and in the absence of special higher-order skills, (2) COG fixations reliably reduced the number of stimulus fixations and their dwell times, indicating processing of multiple distractors, and (3) the proportion of COG fixations was dynamically adapted to potential information gain of COG locations. A second experiment showed that COG fixations are diminished when stimulus positions unpredictably vary across trials. Together, the results support the multiple-item processing view, which has important implications for current theories of visual search.

In order to explore the role of catecholamine and Ca2+ in the synaptic transmission from taste cells to sensory nerve terminals, the effects of various agents added to an artificial solution perfusing the lingual artery on the frog taste nerve responses were examined. The injection of reserpine or guanetidine, which are catecholamine-depleting agents, led to a great reduction of the frog taste nerve responses. The addition of catecholamines to the perfusing solution did not practically enhance the spontaneous impulse discharges, but did recover the response to all the taste stimuli examined. Norepinephrine was most effective and is the most likely candidate for the transmitter. The enhancement of the responses by norepinephrine was suppressed by desipramine, cocaine, or imipramine, which suggests that the enhancement was brought about by incorporation of norepinephrine into taste cells. In a previous paper (Nagahama, S., Y. Kobatake, and K. Kurihara, 1982. J. Gen. Physiol. 80:785), we showed that the responses to the stimuli of one group depended on Ca2+, cGMP, and cAMP added to the perfusing solution and those to the stimuli of another group did not depend on these agents. After the injection or addition of reserpine to the lingual artery, which probably modified injection or addition of reserpine to the lingual artery, which probably modified the permeability of the artery, the responses to the stimuli of the latter group also came to exhibit dependences on these agents, which indicates that the responses to all the taste stimuli have dependences on Ca2+, cGMP, and cAMP.

AbstractBackground and aimsQuantitative sensory testing of thermal perception (QTT) is a valuable method in clinical and experimental assessment of the function of small nerve fibres. Previous studies have indicated existence of spatial summation for warmth, cool and heat pain stimulation, but study designs and assessment methods have not always been mutually consistent. The aims of this study were, first, to examine spatial summation of QTT by differently sized contact thermodes, and, second, to evaluate if these differences are significant from a clinical and scientific perspective.MethodsSixteen healthy subjects were included. Warmth detection (WDT), cool detection (CDT) and heat pain (HPT) thresholds were assessed in random order, with the stimulation areas of the contact thermodes of 3.0, 6.3 and 12.5 cm2, blinded to the subjects. Assessments were made bilaterally at volar part of the distal arm and medial part of the lower leg. Data analyses were by a mixed model with random effect for subject and fixed-effects for the variables, site (arm/leg), thermode area (ln thermode area) and side (dominant/non-dominant), in addition to conventional pairwise non-parametric comparisons.ResultsData from 2 subjects were excluded. In the remaining 14 subjects only 4 subjects were able to identify the correct sequence of thermode sizes. The model demonstrated highly statistical significant relationships regarding main effects: thermode area (P < 0.0001) and stimulation site (P < 0.0001; except for CDT P = 0.011). The only significant interaction was between thermode area*site (P = 0.005) for CDT. The study demonstrated in 17 of 18 possible comparisons between thermode size and stimulation site, a significant spatial summation for WDT, CDT and HPT.ConclusionThis randomized, single-blind study of thermal thresholds demonstrated spatial summation and that considerable deviations may occur if values obtained with differing thermode sizes are used uncritically.ImplicationsData from the present study enable interpolation of thermal thresholds with differing thermode sizes, facilitating comparisons across studies.

The researcher collected about twenty-one words in Ancient Egyptian language, each of them meaning anger; as well as many derivations of these words through sign commutation, sign germination, and sign additions (such as causatives; of the infinitive). Specific words may also be added some of these lexical meanings to form expressions denoting to anger and its responses simultaneously. The researcher noted that some of these words expressed the meaning of anger contextually, not lexically, due to the connection between its lexical meanings and emotional responses of anger. The emotion stimuli of anger, or stressful events that led to it, combined in Ancient Egypt, stimuli related to the abuse and harm to the angry, materially and morally (such as honor violation, assault and battery, losing wishes, difference of opinion; and may be also as a result of the other‘s misconduct, the misconduct toward the ruler and the country‘s security). Obviously, this latter type of stimuli associated with the king personality (such as his anger concerning triumph delay, contumacy toward him and his country, as well as threaten its security). The ancient Egyptian noted, through experience, that anger of the Warrior King had an impact in achieving victory; it is an effect that was proven by modern psychology; this led the ancient Egyptian to connect permanently between the anger emotion of the king and his military activities. So the desire to winning represented permanent stimuli, tempted the royal anger through wars. This is known in modern psychology “Behavioral Reactions”, that is if anger achieved a positive result for an individual, it would be an encouragement for an individual to use it in similar situations afterward. Finally, we have another type of anger stimuli associated with the deceased; it is his expectations to be exposed in the afterlife by forms of abuse and harm that would prevent him from obtaining what he wishes. The researcher divided his study into two parts, tracked in the first the lexical meanings denoting anger in ancient Egyptian language, according to its order in the ancient Egyptian dictionaries. The second part discussed the anger stimuli in light of the ancient Egyptian texts. The last part has three topics, guided by modern psychology, the first is entitled “The Conditions and External Factors”; the second is “The Reactions Behavioral”; and the last topic is “The Expectations”. (Please note that this article is in Arabic)

In a number of experiments the effects of presenting different categories of art in contrasting order were explored. In the first experiment traditional and abstract paintings and Chinese calligraphy were used as stimuli, each type was contrasted with the other two, which led to shifts in appreciation as well as in perceived complexity. Two more experiments were performed. In one of these experiments fragments of traditional and modern classical music were presented. The same effect was found as when traditional and abstract paintings were contrasted: enhancement of the appreciation of traditional music but no decrease in the appreciation of modern music. It seems that when art is concerned only positive contrast effects are obtained. A possible explanation could be that it is considered socially undesirable to admit a lesser appreciation of modern than of traditional art. To test this hypothesis, socially ‘neutral’ stimuli, Chinese ideographs, differing in aesthetic quality, were contrasted. This yielded the expected positive as well as negative effects.

Crocodilians are important for understanding the evolutionary history of amniote neural systems as they are the nearest extant relatives of modern birds and share a stem amniote ancestor with mammals. Although the crocodilian brain has been investigated anatomically, functional studies are rare. Here, we employed functional magnetic resonance imaging (fMRI), never tested in poikilotherms, to investigate crocodilian telencephalic sensory processing. Juvenile Crocodylus niloticus were placed in a 7 T MRI scanner to record blood oxygenation level-dependent (BOLD) signal changes during the presentation of visual and auditory stimuli. Visual stimulation increased BOLD signals in rostral to mid-caudal portions of the dorso-lateral anterior dorsal ventricular ridge (ADVR). Simple auditory stimuli led to signal increase in the rostromedial and caudocentral ADVR. These activation patterns are in line with previously described projection fields of diencephalic sensory fibres. Furthermore, complex auditory stimuli activated additional regions of the caudomedial ADVR. The recruitment of these additional, presumably higher-order, sensory areas reflects observations made in birds and mammals. Our results indicate that structural and functional aspects of sensory processing have been likely conserved during the evolution of sauropsids. In addition, our study shows that fMRI can be used to investigate neural processing in poikilotherms, providing a new avenue for neurobiological research in these critical species.

The presence of flanking stimuli decreases sensitivity in many visual tasks. Earlier we showed that size perception depends on the distance between objects (Bondarko and Danilova, 1996 Perception25 Supplement, 94). Now we suggest that flanks not only decrease sensitivity, but also lead to misperception of size. To test this hypothesis we studied the perception of spatial interval for a set of separations from 6 to 33 min−1 in the presence of two vertical flanking lines. The method of constant stimuli was used in a temporal 2AFC paradigm. Reference stimuli were two vertical lines with separation S, either with or without two symmetrical external flanking lines. The distance to the flanking lines varied from 1/4 S to 3 S in steps of 1/4 S. The test stimuli were just two lines. The first stimulus in the pair could be either the test or the reference. Observers had to report whether the distance between the two central lines in the first stimulus were smaller or larger than the distance in the second stimulus. Probit analysis was used to estimate the threshold and the point of subjective equality (PSE). We found that the PSE implied overestimation by up to 10% of the spatial intervals for the smallest distances to the flanking lines. Increasing distances to the flanking lines finally led to slight underestimation. The strength of the illusion depended on the order of presentation of the reference and test stimuli. Thresholds increased for the smallest distances to flanking lines. Our results confirmed the hypothesis that flanks can induce distortions in size perception. We suggest that our experimental situation could be considered as a one-dimensional case of geometrical visual illusions such as the Ebbinghaus illusion.

In natural environments complex and continuous auditory stimulation is virtually ubiquitous. The human auditory system has evolved to efficiently process an infinitude of everyday sounds, which range from short, simple bursts of noise to signals with a much higher order of information such as speech. Investigation of temporal processing in this system using the event-related potential (ERP) technique has led to great advances in our knowledge. However, this method is restricted by the need to present simple, discrete, repeated stimuli to obtain a useful response. Alternatively the continuous auditory steady-state response is used, although this method reduces the evoked response to its fundamental frequency component at the expense of useful information on the timing of response transmission through the auditory system. In this report, we describe a method for eliciting a novel ERP, which circumvents these limitations, known as the AESPA (auditory-evoked spread spectrum analysis). This method uses rapid amplitude modulation of audio carrier signals to estimate the impulse response of the auditory system. We show AESPA responses with high signal-to-noise ratios obtained using two types of carrier wave: a 1-kHz tone and broadband noise. To characterize these responses, they are compared with auditory-evoked potentials elicited using standard techniques. A number of similarities and differences between the responses are noted and these are discussed in light of the differing stimulation and analysis methods used. Data are presented that demonstrate the generalizability of the AESPA method and a number of applications are proposed.

Le traumatisme craniocérébral léger (TCCL) a des effets complexes sur plusieurs fonctions cérébrales, dont l’évaluation et le suivi peuvent être difficiles. Les problèmes visuels et les troubles de l’équilibre font partie des plaintes fréquemment rencontrées après un TCCL. En outre, ces problèmes peuvent continuer à affecter les personnes ayant eu un TCCL longtemps après la phase aiguë du traumatisme. Cependant, les évaluations cliniques conventionnelles de la vision et de l’équilibre ne permettent pas, la plupart du temps, d’objectiver ces symptômes, surtout lorsqu’ils s’installent durablement. De plus, il n’existe pas, à notre connaissance, d’étude longitudinale ayant étudié les déficits visuels perceptifs, en tant que tels, ni les troubles de l’équilibre secondaires à un TCCL, chez l’adulte. L’objectif de ce projet était donc de déterminer la nature et la durée des effets d’un tel traumatisme sur la perception visuelle et sur la stabilité posturale, en évaluant des adultes TCCL et contrôles sur une période d’un an. Les mêmes sujets, exactement, ont participé aux deux expériences, qui ont été menées les mêmes jours pour chacun des sujets. L’impact du TCCL sur la perception visuelle de réseaux sinusoïdaux définis par des attributs de premier et de second ordre a d’abord été étudié. Quinze adultes diagnostiqués TCCL ont été évalués 15 jours, 3 mois et 12 mois après leur traumatisme. Quinze adultes contrôles appariés ont été évalués à des périodes identiques. Des temps de réaction (TR) de détection de clignotement et de discrimination de direction de mouvement ont été mesurés. Les niveaux de contraste des stimuli de premier et de second ordre ont été ajustés pour qu’ils aient une visibilité comparable, et les moyennes, médianes, écarts-types (ET) et écarts interquartiles (EIQ) des TR correspondant aux bonnes réponses ont été calculés. Le niveau de symptômes a également été évalué pour le comparer aux données de TR. De façon générale, les TR des TCCL étaient plus longs et plus variables (plus grands ET et EIQ) que ceux des contrôles. De plus, les TR des TCCL étaient plus courts pour les stimuli de premier ordre que pour ceux de second ordre, et plus variables pour les stimuli de premier ordre que pour ceux de second ordre, dans la condition de discrimination de mouvement. Ces observations se sont répétées au cours des trois sessions. Le niveau de symptômes des TCCL était supérieur à celui des participants contrôles, et malgré une amélioration, cet écart est resté significatif sur la période d’un an qui a suivi le traumatisme. La seconde expérience, elle, était destinée à évaluer l’impact du TCCL sur le contrôle postural. Pour cela, nous avons mesuré l’amplitude d’oscillation posturale dans l’axe antéropostérieur et l’instabilité posturale (au moyen de la vitesse quadratique moyenne (VQM) des oscillations posturales) en position debout, les pieds joints, sur une surface ferme, dans cinq conditions différentes : les yeux fermés, et dans un tunnel virtuel tridimensionnel soit statique, soit oscillant de façon sinusoïdale dans la direction antéropostérieure à trois vitesses différentes. Des mesures d’équilibre dérivées de tests cliniques, le Bruininks-Oseretsky Test of Motor Proficiency 2nd edition (BOT-2) et le Balance Error Scoring System (BESS) ont également été utilisées. Les participants diagnostiqués TCCL présentaient une plus grande instabilité posturale (une plus grande VQM des oscillations posturales) que les participants contrôles 2 semaines et 3 mois après le traumatisme, toutes conditions confondues. Ces troubles de l’équilibre secondaires au TCCL n’étaient plus présents un an après le traumatisme. Ces résultats suggèrent également que les déficits affectant les processus d’intégration visuelle mis en évidence dans la première expérience ont pu contribuer aux troubles de l’équilibre secondaires au TCCL. L’amplitude d’oscillation posturale dans l’axe antéropostérieur de même que les mesures dérivées des tests cliniques d’évaluation de l’équilibre (BOT-2 et BESS) ne se sont pas révélées être des mesures sensibles pour quantifier le déficit postural chez les sujets TCCL. L’association des mesures de TR à la perception des propriétés spécifiques des stimuli s’est révélée être à la fois une méthode de mesure particulièrement sensible aux anomalies visuomotrices secondaires à un TCCL, et un outil précis d’investigation des mécanismes sous-jacents à ces anomalies qui surviennent lorsque le cerveau est exposé à un traumatisme léger. De la même façon, les mesures d’instabilité posturale se sont révélées suffisamment sensibles pour permettre de mesurer les troubles de l’équilibre secondaires à un TCCL. Ainsi, le développement de tests de dépistage basés sur ces résultats et destinés à l’évaluation du TCCL dès ses premières étapes apparaît particulièrement intéressant. Il semble également primordial d’examiner les relations entre de tels déficits et la réalisation d’activités de la vie quotidienne, telles que les activités scolaires, professionnelles ou sportives, pour déterminer les impacts fonctionnels que peuvent avoir ces troubles des fonctions visuomotrice et du contrôle de l’équilibre.
Mild traumatic brain injury (mTBI) has complex effects on several brain functions that can be difficult to assess and follow-up. Visual and balance problems are frequently reported after an mTBI. Furthermore, these problems can still affect mTBI individuals far beyond the acute stage of injury. However, standard clinical assessments of vision and balance most often fail to objectivize these symptoms, especially if they are lingering. Moreover, to our knowledge, no longitudinal study investigated either mTBI-related deficits of visual perception per se, or mTBI-related balance deficits in adults. The aim of this project was to determine the nature and duration of the effects of such a traumatism on visual perception as well as on postural stability, by evaluating mTBI and control adults over a one-year period. Exactly the same subjects participated in both experiments, which took place on the same days for every subject. The impact of mTBI on the visual perception of sine-wave gratings defined by first-and second-order characteristics was, first, investigated. Fifteen adults diagnosed with mTBI were assessed at 15 days, 3 months and 12 months after injury. Fifteen matched controls followed the same testing schedule. Reaction times (RTs) for flicker detection and motion direction discrimination were measured. Stimulus contrast of first- and second-order patterns was equated to control for visibility, and correct-response RT means, standard deviations (SDs), medians, and interquartile ranges (IQRs) were calculated. The level of symptoms was also evaluated to compare it to RT data. In general in mTBI, RTs were longer and more variable (ie., larger SDs and IQRs), than those of controls. In addition, mTBI participants’ RTs to first-order stimuli were shorter than those to second-order stimuli, and more irregular for first- than for second-order stimuli in the motion condition. All these observations were made over the 3 sessions. The level of symptoms observed in mTBI was higher than that of control participants and this difference did also persist up to one year after the brain injury, despite an improvement. The second experiment, then, investigated the impact of mTBI on postural control. To achieve that, antero-posterior body sway amplitude (BSA) and postural instability (given by body sway velocity root mean square, vRMS) during upright stance, feet together, on a firm surface, were measured in five different conditions: with eyes closed and in a 3D virtual reality tunnel, either static or sinusoidally moving in the antero-posterior direction at 3 different velocities. Balance measures derived from clinical tests, Bruininks-Oseretsky Test of Motor Proficiency 2nd edition (BOT-2) and Balance Error Scoring System (BESS), were also used. Participants diagnosed with mTBI exhibited more postural instability (i.e. higher body sway vRMS) than control participants at 2 weeks and at 3 months post-injury, regardless of the testing condition. These mTBI-related balance deficits were no longer present one year postinjury. These results also suggest that visual processing impairments revealed in the first experiment might have contributed to mTBI-related balance deficits. Anteroposterior BSA as well as measures derived from clinical tests for balance assessment did not appear to be sensitive enough to quantify postural deficits of mTBI participants. The combination of RT measures with particular stimulus properties appeared to be a highly sensitive method for measuring mTBI-induced visuomotor anomalies, and to provide a fine probe of the underlying mechanisms when the brain is exposed to mild trauma. Likewise, postural instability measures prove to be sensitive enough for measuring mTBI-induced balance deficits. Developing screening tests in this respect intended for early post-mTBI use would be of interest. Also, studying relationships of such deficits with performance in daily life activities, such as school, work, or sports, is crucial in order to determine the functional impacts of these alterations in visuomotor and balance functions.

This chapter reviews Fodor’s contribution to the epic Chomsky-Piaget Royaumont debate. The issue that was under discussion was a familiar one, namely, what psychological processes underlie concept learning. Piaget thought concept learning involved the formation and confirmation of hypotheses that a learner generates through the construction and organization of stimuli gathered from the environment, and modifying them when they proved to be inconsistent. However, Fodor pointed out a fundamental flaw in this theory: it is silent about the origin of the concepts used in generating the hypotheses. Fodor argued that in order for these hypotheses to be tested, let alone generated, they needed to have been readily available to the learner, suggesting that all primitive concepts are innate, and that concept acquisition relies on the process of triggering these concepts that are innately available to the learner, and not through construction by means of progressive guesses and trial-and-error.

The basic concept of smart textiles consists of textile structures that can sense and react to different stimuli from their environment. While forecasts indicate how this sector has the potential to grow in the future, a gap remains for smart textiles to become commercially viable. Growth in consumerism and consumption of services and experiences has led to innovative products that satisfy higher order needs including ideas, sensory and emotional fulfilment, cultural experiences and entertainment. The aim of the paper is to understand smart textiles in this context and to identify factors that influence personal ownership in fitness sector. These will help manufacturers and technologists gain insight into consumer experience and contribute to better design, innovation, marketing and services. The research findings identify important features consumers value in their decision making to purchase a smart top in fitness sector. The results contribute to the field of user adoption in smart textiles and conclude with proposals for the direction of future design and technical development.

The goal of this chapter is to present the application of gamification mechanism and social media tools in the promotion of tourism regions and enterprises as well as the promotion of tourism activity itself. The framework distinguishes between stimulus characteristics of the game (promotion mechanism) that lead to sociological responses toward the game (tourism brand) and actual buyers' (tourists') behaviour. Though the game-like mechanism has been applied in tourism for decades and some funware elements are well known among teens – they hardly deal with competition of computer games. Two popular systems of tourism badges in Poland are thus discussed in order to look for reasons of their falling popularity and teenagers' resistance to participate in the systems. Mobile devices enable teens to combine playing and travelling. The development of mobile applications, integrating social gaming, and location-based technology has led to the growing interest in location-based social network marketing, particularly in tourism and hospitality. The chapter concludes with a proposal how to revitalize an old-school system of tourism badges through the modern gamification mechanism combined with social media tools.

The goal of this chapter is to present the application of gamification mechanism and social media tools in the promotion of tourism regions and enterprises as well as the promotion of tourism activity itself. The framework distinguishes between stimulus characteristics of the game (promotion mechanism) that lead to sociological responses toward the game (tourism brand) and actual buyers' (tourists') behaviour. Though the game-like mechanism has been applied in tourism for decades and some funware elements are well known among teens – they hardly deal with competition of computer games. Two popular systems of tourism badges in Poland are thus discussed in order to look for reasons of their falling popularity and teenagers' resistance to participate in the systems. Mobile devices enable teens to combine playing and travelling. The development of mobile applications, integrating social gaming, and location-based technology has led to the growing interest in location-based social network marketing, particularly in tourism and hospitality. The chapter concludes with a proposal how to revitalize an old-school system of tourism badges through the modern gamification mechanism combined with social media tools.

Now that we have quantified the behavior of the cell in response to current pulses and current steps as delivered by the physiologist's microelectrode, let us study the behavior of the cell responding to a more physiological input. For instance, a visual stimulus in the environment will activate cells in the retina and its target, neurons in the lateral geniculate nucleus. These, in turn, make on the order of 50 excitatory synapses onto the apical tree of a layer 5 pyramidal cell in primary visual cortex such as the one we use throughout the book, and about 100-150 synapses onto a layer 4 spiny stellate cell (Peters and Payne, 1993; Ahmed et al., 1994, 1996; Peters, Payne, and Rudd, 1994). All of these synapses will be triggered within a fraction of a millisecond (Alonso, Usrey, and Reid, 1996). Thus, any sensory input to a neuron is likely to activate on the order of 102 synapses, rather than one or two very specific synapses as envisioned in Chap. 5 in the discussion of synaptic AND-NOT logic. This chapter will reexamine the effect of synaptic input to a realistic dendritic tree. We will commence by considering a single synaptic input as a sort of baseline condition. This represents a rather artificial condition; but because the excitatory postsynaptic potential and current at the soma are frequently experimentally recorded and provide important insights into the situation prevailing in the presence of massive synaptic input, we will discuss them in detail. Next we will treat the case of many temporally dispersed synaptic inputs to a leaky integrate-and-fire model and to the passive dendritic tree of the pyramidal cell. In particular, we are interested in uncovering the exact relationship between the temporal input jitter and the output jitter. The bulk of this chapter deals with the effect of massive synaptic input onto the firing behavior of the cell, by making use of the convenient fiction that the detailed temporal arrangement of action potentials is irrelevant for neuronal information processing. This allows us to derive an analytical expression relating the synaptic input to the somatic current and ultimately to the output frequency of the cell.

A mathematical model of the locust hind leg extensor muscle is presented. The model accounts for the force response of the muscle due to individual stimuli under isometric conditions. Experimental data was collected by stimulating the muscle directly and force measured at the tibia. Joint dimensions were calculated, enabling tibial force to be converted into muscle force. In developing a model it was assumed that the response to a single isolated stimulus was linear, but no assumptions were made about the model order. Models of various order were fitted using time and frequency domain methods to data obtained from well-separated input pulses. The response could be approximated as an impulse response, with the response to each stimulus best described by a linear third-order system. Responses where input pulses were not well-separated, so that summation of subsequent pulses occurred, were also investigated. As has been observed in mammalian muscle, both facilitation and force depression were evident in locust muscle. The linear third-order model was found to provide an adequate fit to data in which depression and facilitation were evident if the parameters describing the system were allowed to vary between each response.

This article evaluates an M-order Adaptive Kalman filter analysis on Steady-State Visual Evoked Potentials (SSVEPs). This model is based on finding the original brain source signals from their combined observed EEG signals. At each time step, observed brain signals are filtered according to their ideal reference signals measured from 10, 11, 12 and 13 Hz LED stimuli. SSVEP response detection is based on maximum Signal to Noise Ratio (SNR) of the brain source signals. In each test, the average system accuracy is calculated with and without overlapped time-windows along with system Information Transfer Rate (ITR). The overall system accuracy and ITR are showing promising level of SSVEP detection for future online BCI systems.

The objective of this paper is to study the economic and social results of the post-crisis fiscal policies concerning the Balkan States that are members of the EU. The global crisis, which broke out in the US in 2008, had a deep effect on both developed and developing countries. Until today different policies have been put on the agenda in order to eliminate or alleviate the impacts of the crisis. In this context, bailout and stimulus packages were firstly implemented. Stimulus packages were replaced by austerity policies because of the increasing public debt and budget deficit after 2010. Fiscal policy focused on reducing the debts instead of supporting the economic activities. This study is based on historical and descriptive method. It examines the development of post-crisis fiscal policies in the Balkan States that are members of the EU. In this study, public expenditure, public debt, public deficit and unemployment rate are used as the main indicators. The effects of fiscal policy will be compared between countries. This study also suggests that although the crisis resulted from financial sector, burden of crisis was transferred to public sector. Moreover, in many countries, because of its increasing deficit and debt burden, public sector became depended on financial sector that was rescued before. After the crisis, fiscal policies has led to significant economic and social costs in the Balkan States that are members of the EU.

We have recently reported on experimental observations of silk-elastin-like protein polymers (SELPs) that self-assembled into 1-dimensional nanofibers on mica surfaces upon application of a mechanical stimulus with atomic force microscopy (AFM) in water. SELPs are genetically engineered block co-polymers made of silk-like blocks (Gly-Ala-Gly-Ala-Gly-Ser) from Bombyx mori (silkworm) and elastin-like blocks (Gly-Val-Gly-Val-Pro) from mammalian elastin. The experiment consisted of adsorbing the protein polymer onto a freshly cleaved mica surface, followed by AFM characterization under different sets of imaging parameters, each of which led to different nanofiber coverage rates. In order to gain further understanding of the factors governing the self-assembly process, we utilized multimodal AFM simulation to formulate and guide the implementation of a suitable force modulation strategy, which allowed us to observe trends of the surface coverage rate as a function of the applied peak forces. The simulations suggest that a nearly linear control of the peak tapping forces can be achieved by following simple scaling laws based on the harmonic oscillator model.

In a traditional automotive cooling system, energy optimization could be achieved by controlling the engine temperature by means of several sensors placed inside the cooling circuit. Nevertheless, in some cases the increasing use of a great number of sensor devices makes the control system too bulky, expensive and not sufficiently robust for the intended application. This paper presents the development of a heavy-duty automotive cooling axial fan with morphing blades activated by Shape Memory Alloy (SMA) strips that work as actuator elements in the polymeric blade structure. The application of smart materials to compact, high-energy density devices as well as the development of modeling and control systems has been of great interest during the last decade. SMAs are frequently combined within monolithic or composite host materials to produce adaptive structures whose properties could be tuned in response to external stimuli. The blade was designed to achieve the activation of the strips (purposely thermo-mechanically treated) by means of an air stream flow. With the aim of studying the morphing capability of the adaptive structure together with the recovery behavior of the NiTi strips, four different polymeric compounds have been compared in a specifically-designed wind tunnel. Digital image analysis techniques have been performed to quantitatively analyze the blade deflections and to evaluate the most suitable polymeric matrix for the intended application. As the airstream flow increases in temperature, the strips recover the memorized bent shape, leading to a camber variation. To study the possibility of employing SMA strips as actuator elements, a comparison with common viscous clutch behavior is proposed. The time range actuator response indicates that the SMA strips provide a lower frequency control that fits well with the engine coolant thermal requirement. The experimental results demonstrate the capability of SMA materials to accommodate the lower power actuators in the automotive field. Finally, the blade tip airfoils, reconstructed using a CAD procedure, were used to study the fluid dynamic behavior of the blade tip airfoil. A CFD numerical simulation was carried out in order to highlight the differences in the airfoil performance due to the different shapes of the blade. The analyses showed that the activated blade tip airfoil led to an increase in the lift coefficient according to the stiffness provided by the polymeric compound. This innovative passive control system results from the selection of (i) the memorized shape of the SMA strips and (ii) the polymeric compound used for the blade structure.

The context of the COVID 19 pandemic has forced managers and entrepreneurs to review how they run their businesses and guide their employees. The new normality has brought with it a number of challenges and changes that have produced immediate and profound effects both in the way business is conducted, the online negotiations giving a formal and less human character, and in the way the employees perceive the work carried out exclusively online. Research has revealed a new phenomenon called "Zoom Fatigue" which is reflected in the human psyche through exhaustion and burnout, a phenomenon caused by the intensity and long duration of video calls and frequent online meetings. Additional cognitive processes required by video calls, the concentration required to absorb all the information transmitted, the lack of visual breaks, multitasking, as well as the merging of professional activity with the familiar environment from the comfort of our home, have led to psychological consequences, such as pronounced fatigue, exhaustion or irritation. All these effects are felt differently by men and women, the latter suffering more from videoconferencing and online work. At the same time, extroverts were found to be less tired than introverted people, feeling the effects of the "Zoom Fatigue" phenomenon differently. For the proper conduct of work and for the creation of a healthy organizational climate and an ethical organizational culture, the role of managers in knowing employees at a human level is of outmost importance, in order to best manage such situations and to identify appropriate measures for motivation and support aimed in particular at female and vulnerable personnel. Orientation towards setting a precise schedule for organizing video conferencing, recommending to avoid multitasking and reducing on-screen stimulus, setting visual breaks, avoiding the use of video calls in their spare time are some of the measures that managers can implement among their employees.

The Panel discussion titled “The Presidential Employment Stimulus: Research Opportunities”, was hosted on 10 December 2020 by the Department of Science and Innovation (DSI) and the Academy of Science of South Africa (ASSAf) at the Science Forum South Africa (SFSA) 2020. The Presidential Employment Stimulus was launched in parliament on 15 October as part of government’s Economic Recovery Strategy. It directly funds 800,000 employment opportunities that are being implemented within the current financial year, but it is anticipated that it will also become a medium-term programme. The stimulus includes public employment programmes, job retention programmes and direct support to livelihoods. The single largest programme is run by the Department of Basic Education, which, in the last fortnight, recruited 300,000 young people as school assistants, to assist schools to deal with the setbacks faced as a result of the pandemic. The stimulus supports employment in the environmental sector and over 75,000 subsistence producers are receiving production grants through an input voucher scheme. There is a once-off grant to assist over 100,000 registered and unregistered Early Childhood Development Practitioners back on their feet, as well as a significant stimulus to the creative sector. The session set out to provide an introduction to the Presidential Employment Stimulus Programme (PESP), a key programme within government’s economic recovery plan led by Dr Kate Philip. The key objective was to get input from the research community on how the work that they are already doing and future work could contribute to the M&E efforts and be augmented in such a way that the PESP could become a medium-term programme. The DSI plans to hold further engagements in 2021 to mobilise the wider research community to provide evidence-based research in order to shape the research agenda that would support the M&E work and identify short-term issues that need to be factored into the department’s work plans, under the guidance of Dr Philip.