933 resultados para theories of action
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It has been proposed that there is a core impairment in autism spectrum conditions (ASC) to the mirror neuron system (MNS): If observed actions cannot be mapped onto the motor commands required for performance, higher order sociocognitive functions that involve understanding another person's perspective, such as theory of mind, may be impaired. However, evidence of MNS impairment in ASC is mixed. The present study used an 'automatic imitation' paradigm to assess MNS functioning in adults with ASC and matched controls, when observing emotional facial actions. Participants performed a pre-specified angry or surprised facial action in response to observed angry or surprised facial actions, and the speed of their action was measured with motion tracking equipment. Both the ASC and control groups demonstrated automatic imitation of the facial actions, such that responding was faster when they acted with the same emotional expression that they had observed. There was no difference between the two groups in the magnitude of the effect. These findings suggest that previous apparent demonstrations of impairments to the MNS in ASC may be driven by a lack of visual attention to the stimuli or motor sequencing impairments, and therefore that there is, in fact, no MNS impairment in ASC. We discuss these findings with reference to the literature on MNS functioning and imitation in ASC, as well as theories of the role of the MNS in sociocognitive functioning in typical development.
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The existence of a specialized imitation module in humans is hotly debated. Studies suggesting a specific imitation impairment in individuals with autism spectrum disorders (ASD) support a modular view. However, the voluntary imitation tasks used in these studies (which require socio-cognitive abilities in addition to imitation for successful performance) cannot support claims of a specific impairment. Accordingly, an automatic imitation paradigm (a ‘cleaner’ measure of imitative ability) was used to assess the imitative ability of 16 adults with ASD and 16 non-autistic matched control participants. Participants performed a prespecified hand action in response to observed hand actions performed either by a human or a robotic hand. On compatible trials the stimulus and response actions matched, while on incompatible trials the two actions did not match. Replicating previous findings, the Control group showed an automatic imitation effect: responses on compatible trials were faster than those on incompatible trials. This effect was greater when responses were made to human than to robotic actions (‘animacy bias’). The ASD group also showed an automatic imitation effect and a larger animacy bias than the Control group. We discuss these findings with reference to the literature on imitation in ASD and theories of imitation.
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Iatrogenic errors and patient safety in clinical processes are an increasing concern. The quality of process information in hardcopy or electronic form can heavily influence clinical behaviour and decision making errors. Little work has been undertaken to assess the safety impact of clinical process planning documents guiding the clinical actions and decisions. This paper investigates the clinical process documents used in elective surgery and their impact on latent and active clinical errors. Eight clinicians from a large health trust underwent extensive semi- structured interviews to understand their use of clinical documents, and their perceived impact on errors and patient safety. Samples of the key types of document used were analysed. Theories of latent organisational and active errors from the literature were combined with the EDA semiotics model of behaviour and decision making to propose the EDA Error Model. This model enabled us to identify perceptual, evaluation, knowledge and action error types and approaches to reducing their causes. The EDA error model was then used to analyse sample documents and identify error sources and controls. Types of knowledge artefact structures used in the documents were identified and assessed in terms of safety impact. This approach was combined with analysis of the questionnaire findings using existing error knowledge from the literature. The results identified a number of document and knowledge artefact issues that give rise to latent and active errors and also issues concerning medical culture and teamwork together with recommendations for further work.
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Relating the measurable, large scale, effects of anaesthetic agents to their molecular and cellular targets of action is necessary to better understand the principles by which they affect behavior, as well as enabling the design and evaluation of more effective agents and the better clinical monitoring of existing and future drugs. Volatile and intravenous general anaesthetic agents (GAs) are now known to exert their effects on a variety of protein targets, the most important of which seem to be the neuronal ion channels. It is hence unlikely that anaesthetic effect is the result of a unitary mechanism at the single cell level. However, by altering the behavior of ion channels GAs are believed to change the overall dynamics of distributed networks of neurons. This disruption of regular network activity can be hypothesized to cause the hypnotic and analgesic effects of GAs and may well present more stereotypical characteristics than its underlying microscopic causes. Nevertheless, there have been surprisingly few theories that have attempted to integrate, in a quantitative manner, the empirically well documented alterations in neuronal ion channel behavior with the corresponding macroscopic effects. Here we outline one such approach, and show that a range of well documented effects of anaesthetics on the electroencephalogram (EEG) may be putatively accounted for. In particular we parameterize, on the basis of detailed empirical data, the effects of halogenated volatile ethers (a clinically widely used class of general anaesthetic agent). The resulting model is able to provisionally account for a range of anaesthetically induced EEG phenomena that include EEG slowing, biphasic changes in EEG power, and the dose dependent appearance of anomalous ictal activity, as well as providing a basis for novel approaches to monitoring brain function in both health and disease.
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The study of workarounds (WA) has increased in importance due to their impact on patient safety and efficiency. However, there are no adequate theories to explain the motivation to create and use a workaround in a healthcare sitting. Although theories of technology acceptance help to understand the reasons to accept or reject technology, they fail to explain drivers for alternatives. Also workarounds involve creators and performers that have different motivations. Models such as Theory of Planned Behaviour (TPB) or Theory of Reasoned Action (TRA) can help to explain the role of workaround users, but lack explanation of workaround creators’ dynamics. Our aim is to develop a theoretical foundation to explain workaround motivation behaviour models with norms that relate to sanctions to provide an integrated Workaround Motivation Model; WAMM. The development of WAMM model is explained in this paper based on workaround cases as part of further research to establish the model.
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In a culture of performativity, action research offers teachers an opportunity to step back and reflect on their practice. This paper reports on a collaborative project carried out between a university and a secondary school in England, in which the university staff supported an action research project within the school. Five school teachers volunteered to engage in this project. They were given an introduction to action research and were assigned a university researcher to support them. Despite the common input and a common school culture, the teachers engaged in very different models of action research. This article reports on two teachers whose approaches were dissimilar. It examines these differences and suggests that they can be explained by considering the teachers’ different responses to a performativity culture.
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The generation of flow and current vortices in the dayside auroral ionosphere has been predicted for two processes ocurring at the dayside magnetopause. The first of these mechanisms is time-dependent magnetic reconnection, in “flux transfer events” (FTEs); the second is the action of solar wind dynamic pressure changes. The ionospheric flow signature of an FTE should be a twin vortex, with the mean flow velocity in the central region of the pattern equal to the velocity of the pattern as a whole. On the other hand, a pulse of enhanced or reduced dynamic pressure is also expected to produce a twin vortex, but with the central plasma flow being generally different in speed from, and almost orthogonal to, the motion of the whole pattern. In this paper, we make use of this distinction to discuss recent observations of vortical flow patterns in the dayside auroral ionosphere in terms of one or other of the proposed mechanisms. We conclude that some of the observations reported are consistent only with the predicted signature of FTEs. We then evaluate the dimensions of the open flux tubes required to explain some recent simultaneous radar and auroral observations and infer that they are typically 300 km in north–south extent but up to 2000 km in longitudinal extent (i.e., roughly 5 hours of MLT). Hence these observations suggest that recent theories of FTEs which invoke time-varying reconnection at an elongated neutral line may be correct. We also present some simultaneous observations of the interplanetary magnetic field (IMF) and solar wind dynamic pressure (observed using the IMP8 satellite) and the ionospheric flow (observed using the EISCAT radar) which are also only consistent with the FTE model. We estimate that for continuously southward IMF (
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In this paper we show that heritage speakers and returnees are fundamentally different from the majority of adult second language learners with respect to their use of collocations (Laufer & Waldman, 2011). We compare the use of lexical collocations involving yap- “do” and et- “do” among heritage speakers of Turkish in Germany (n=45) with those found among Turkish returnees (n=65) and Turkish monolinguals (n=69). Language use by returnees is an understudied resource although this group can provide crucial insights into the specific language ability of heritage speakers. Results show that returnees who had been back for one year avoid collocations with yap- and use some hypercorrect forms in et-, whilst returnees who had been back for seven years upon recording produce collocations that are quantitatively and qualitatively similar to those of monolingual speakers of Turkish. We discuss implications for theories of ultimate attainment and incomplete acquisition in heritage speakers.
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Estrogen is a ligand for the estrogen receptor (ER), which on binding 17beta-estradiol, functions as a ligand-activated transcription factor and regulates the transcription of target genes. This is the slow genomic mode of action. However, rapid non-genomic actions of estrogen also exist at the cell membrane. Using a novel two-pulse paradigm in which the first pulse rapidly initiates non-genomic actions using a membrane-limited estrogen conjugate (E-BSA), while the second pulse promotes genomic transcription from a consensus estrogen response element (ERE), we have demonstrated that rapid actions of estrogen potentiate the slower transcriptional response from an ERE-reporter in neuroblastoma cells. Since rapid actions of estrogen activate kinases, we used selective inhibitors in the two-pulse paradigm to determine the intracellular signaling cascades important in such potentiation. Inhibition of protein kinase A (PKA), PKC, mitogen activated protein kinase (MAPK) or phosphatidylinositol 3-OH kinase (PI-3K) in the first pulse decreases potentiation of transcription. Also, our data with both dominant negative and constitutive mutants of Galpha subunits show that Galpha(q) initiates the rapid signaling cascade at the membrane in SK-N-BE(2)C neuroblastoma cells. We discuss two models of multiple kinase activation at the membrane Pulses of estrogen induce lordosis behavior in female rats. Infusion of E-BSA into the ventromedial hypothalamus followed by 17beta-estradiol in the second pulse could induce lordosis behavior, demonstrating the applicability of this paradigm in vivo. A model where non-genomic actions of estrogen couple to genomic actions unites both aspects of hormone action.
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This chapter analyses how children, and especially boys, are constructed as ‘savage’ in relation to warlike toys and representations that narrate particular versions of conflict, such as war and terrorism. The chapter uses Action Man toys as a case study that is contextualized against a wider background of other toys, television programmes and films. Action Man is most familiar as a twelve-inch costumed toy figure, but the brand also extends into related media representations such as television programmes, comics and advertising. The chapter focuses increasingly on the specifics of Action Man representations produced from the 1960s to the 1990s, prefacing this detailed discussion with some examples of transmedia texts aimed at children in film and television. This chapter suggests that making the toy a central object of analysis allows for insights into representations of the gendered body that are particularly useful for work on the child-savage analogy. Some of the cultural meanings of war toys, warlike play and representations of war that can be analysed from this perspective include their role in the construction of masculine identity, their representation of particular wars and warlikeness in general, and their relationship to consumer society. This complex of meanings exhibits many of the contradictions that inhabit the construction of ‘the child’ in general, such as that the often extreme masculinity of war toys and games is countered by an aesthetic of spatial disposition, collecting and sometimes nurturing that is more conventionally feminine. Such inter-dependent but apparently opposed meanings can also be seen in the construction of the child as untainted by adult corruption yet also savage, or as in need of adult guidance yet also offering a model of innocence and purity that adults are expected to admire.
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The sexual system of the symbiotic shrimp Thor amboinensis is described, along with observations on sex ratio and host-use pattern of different populations. We used a comprehensive approach to elucidate the previously unknown sexual system of this shrimp. Dissections, scanning electron microscopy, size-frequency distribution analysis, and laboratory observations demonstrated that T amboinensis is a protandric hermaphrodite: shrimp first mature as males and change into females later in life. Thor amboinensis inhabited the large and structurally heterogeneous sea anemone Stichoclactyla helianthus in large groups (up to 11 individuals) more frequently than expected by chance alone. Groups exhibited no particularly complex social structure and showed male-biased sex ratios more frequently than expected by chance alone. The adult sex ratio was male-biased in the four separate populations studied, one of them being thousands of kilometers apart from the others. This study supports predictions central to theories of resource monopolization and sex allocation. Dissections demonstrated that unusually large males were parasitized by an undescribed species of isopod (family Entoniscidae). Infestation rates were similarly low in both sexes (approximate to 11%-12%). The available information suggests that T. amboinensis uses pure search promiscuity as a mating system. This hypothesis needs to be formally tested with mating behavior observations and field measurements on the movement pattern of both sexes of the species. Further detailed studies on the lifestyle and sexual system of all the species within this genus and the development of a molecular phylogeny are necessary to elucidate the evolutionary history of gender expression in the genus Thor.
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We show that the S parameter is not finite in theories of electroweak symmetry breaking in a slice of anti-de Sitter five-dimensional space, with the light fermions localized in the ultraviolet. We compute the one-loop contributions to S from the Higgs sector and show that they are logarithmically dependent on the cutoff of the theory. We discuss the renormalization of S, as well as the implications for bounds from electroweak precision measurements on these models. We argue that, although in principle the choice of renormalization condition could eliminate the S parameter constraint, a more consistent condition would still result in a large and positive S. On the other hand, we show that the dependence on the Higgs mass in S can be entirely eliminated by the renormalization procedure, making it impossible in these theories to extract a Higgs mass bound from electroweak precision constraints.
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The existence of an interpolating master action does not guarantee the same spectrum for the interpolated dual theories. In the specific case of a generalized self-dual (GSD) model defined as the addition of the Maxwell term to the self-dual model in D = 2 + 1, previous master actions have furnished a dual gauge theory which is either nonlocal or contains a ghost mode. Here we show that by reducing the Maxwell term to first order by means of an auxiliary field we are able to define a master action which interpolates between the GSD model and a couple of non-interacting Maxwell-Chern-Simons theories of opposite helicities. The presence of an auxiliary field explains the doubling of fields in the dual gauge theory. A generalized duality transformation is defined and both models can be interpreted as self-dual models. Furthermore, it is shown how to obtain the gauge invariant correlators of the non-interacting MCS theories from the correlators of the self-dual field in the GSD model and vice-versa. The derivation of the non-interacting MCS theories from the GSD model, as presented here, works in the opposite direction of the soldering approach.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Toxic baits are the most used control method for leaf-cutting ants due to their high effectiveness and because they are considered the safest for humans. Taking into account that the importance of leaf-cutting ants as pests, knowing the process by which dispersal and worker contamination is achieved becomes essential to understand several aspects about the functioning of a bait-borne AI (active ingredient) used in toxic baits. It has been established that an effective toxic bait should have a delayed- action AI, but its dispersion among the different sizes of workers is unknown. Workers of different sizes are involved in quite different tasks such foraging, cultivation of symbiotic macrofungus or control of deleterious microfungi. Therefore, we prepared a toxic bait containing the delayed-action AI sulfluramid and a dye (Rhodamine B) as an AI tracer in order to study dispersal and contamination in colonies, evaluated at different periods and in relation to different workers' sizes. Both field and laboratory colonies were evaluated. The great level of contamination, about 50% at 24 hours, in all sizes of workers demonstrates that worker contact with toxic bait is intense within this period. The distribution in field and laboratory colonies was similar. This contamination pattern is probably enough to cause the colony to die because of contamination of smaller workers, leading to the loss of control of the aggressive microfungi, which can quickly overgrow the symbiotic fungus culture. The dispersal dynamics of AI in leaf-cutting ant workers is important for investigations on the mode of action of this insecticide in the colony, and as a reference in future studies, such as those attempting to reduce the concentration of AIs in baits to reduce their environmental impact, or for facilitation of new AI screening.