96 research outputs found

    Mechanical characteristics of the hypereutectic silumin processed by ionelectron-plasma modification

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    In this paper, the possibility of modifying the surface of a hypereutectic silumin (Al-(18-24) wt.%Si) is shown. Modification of the samples was carried out in two stages. At the first stage, a "film (Zr-5% Ti-5% Cu) / (Al- (18-24) wt.% Si) film system was formed by an ion-plasma method with an arc-sputtering of a Zr-5% Ti-5 cathode % Cu in the "TRIO" installation (IHCE SB RAS). In the second stage, the surface layer of the silumin of the hypereutectic composition was doped by melting the "film-substrate" system with an intense pulsed electron beam at the "SOLO" installation

    Влияние добавки нановолокон оксида алюминия на стойкость к низкотемпературному разложению керамики на основе диоксида циркония

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    Cerebral activation in the elderly may depend on general cognitive decline as well as actual retrieval performance. Consequently, activation between subjects with and without Mild Cognitive Impairment (MCI), and between remembered and non-remembered words was compared. Twenty-one MCI and 29 healthy control subjects learned 180 nouns. During retrieval, subjects had to discriminate these and 180 distractor words. fMRI identified response-related activation. Most retrieval-related activation was comparable in both groups. However, MCI subjects showed more activation in the prefrontal cortex than controls during processing of hits and correct rejections. Hits showed increased activation than misses in the precuneus and left lateral parieto-occipital cortex; misses showed more activation than correct rejections in the precuneus to cuneus. Verbal retrieval activated a large common network in the elderly independently of MCI. Increased activation in MCI subjects in prefrontal cortex depends on response category. Activation differences between response categories might reflect success (hits) and effort (misses). Increased retrieval-related activation may be used as early marker in subjects at risk of Alzheimer's disease

    Are women better mindreaders? Sex differences in neural correlates of mentalizing detected with functional MRI

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    <p>Abstract</p> <p>Background</p> <p>The ability to mentalize, i.e. develop a Theory of Mind (ToM), enables us to anticipate and build a model of the thoughts, emotions and intentions of others. It has long been hypothesised that women differ from men in their mentalizing abilities. In the present fMRI study we examined the impact of (1) gender (women vs. men) and (2) game partner (human vs. computer) on ToM associated neural activity in the medial prefrontal cortex. Groups of men (n = 12) and women (n = 12) interacted in an iterated classical prisoner's dilemma forced choice situation with alleged human and computer partners who were outside the scanner.</p> <p>Results</p> <p>Both the conditions of playing against putative human as well as computer partners led to activity increases in mPFC, ACC and rTPJ, constituting the classic ToM network. However, mPFC/ACC activity was more pronounced when participants believed they were playing against the alleged human partner. Differences in the medial frontal lobe activation related to the sex of the participants could be demonstrated for the human partner > computer partner contrast.</p> <p>Conclusion</p> <p>Our data demonstrate differences in medial prefrontal brain activation during a ToM task depending on both the gender of participants and the game partner.</p

    Involvement of the Intrinsic/Default System in Movement-Related Self Recognition

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    The question of how people recognize themselves and separate themselves from the environment and others has long intrigued philosophers and scientists. Recent findings have linked regions of the ‘default brain’ or ‘intrinsic system’ to self-related processing. We used a paradigm in which subjects had to rely on subtle sensory-motor synchronization differences to determine whether a viewed movement belonged to them or to another person, while stimuli and task demands associated with the “responded self” and “responded other” conditions were precisely matched. Self recognition was associated with enhanced brain activity in several ROIs of the intrinsic system, whereas no differences emerged within the extrinsic system. This self-related effect was found even in cases where the sensory-motor aspects were precisely matched. Control conditions ruled out task difficulty as the source of the differential self-related effects. The findings shed light on the neural systems underlying bodily self recognition

    Can Machines Think? Interaction and Perspective Taking with Robots Investigated via fMRI

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    Krach S, Hegel F, Wrede B, Sagerer G, Binkofski F, Kircher T. Can Machines Think? Interaction and Perspective Taking with Robots Investigated via fMRI. PLoS ONE. 2008;3(7): e2597.Background When our PC goes on strike again we tend to curse it as if it were a human being. Why and under which circumstances do we attribute human-like properties to machines? Although humans increasingly interact directly with machines it remains unclear whether humans implicitly attribute intentions to them and, if so, whether such interactions resemble human-human interactions on a neural level. In social cognitive neuroscience the ability to attribute intentions and desires to others is being referred to as having a Theory of Mind (ToM). With the present study we investigated whether an increase of human-likeness of interaction partners modulates the participants' ToM associated cortical activity. Methodology/Principal Findings By means of functional magnetic resonance imaging (subjects n = 20) we investigated cortical activity modulation during highly interactive human-robot game. Increasing degrees of human-likeness for the game partner were introduced by means of a computer partner, a functional robot, an anthropomorphic robot and a human partner. The classical iterated prisoner's dilemma game was applied as experimental task which allowed for an implicit detection of ToM associated cortical activity. During the experiment participants always played against a random sequence unknowingly to them. Irrespective of the surmised interaction partners' responses participants indicated having experienced more fun and competition in the interaction with increasing human-like features of their partners. Parametric modulation of the functional imaging data revealed a highly significant linear increase of cortical activity in the medial frontal cortex as well as in the right temporo-parietal junction in correspondence with the increase of human-likeness of the interaction partner (computer<functional robot<anthropomorphic robot<human). Conclusions/Significance Both regions correlating with the degree of human-likeness, the medial frontal cortex and the right temporo-parietal junction, have been associated with Theory-of-Mind. The results demonstrate that the tendency to build a model of another's mind linearly increases with its perceived human-likeness. Moreover, the present data provides first evidence of a contribution of higher human cognitive functions such as ToM in direct interactions with artificial robots. Our results shed light on the long-lasting psychological and philosophical debate regarding human-machine interaction and the question of what makes humans being perceived as human

    A Genome-Wide Identification Analysis of Small Regulatory RNAs in Mycobacterium tuberculosis by RNA-Seq and Conservation Analysis

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    We propose a new method for smallRNAs (sRNAs) identification. First we build an effective target genome (ETG) by means of a strand-specific procedure. Then we propose a new bioinformatic pipeline based mainly on the combination of two types of information: the first provides an expression map based on RNA-seq data (Reads Map) and the second applies principles of comparative genomics leading to a Conservation Map. By superimposing these two maps, a robust method for the search of sRNAs is obtained. We apply this methodology to investigate sRNAs in Mycobacterium tuberculosis H37Rv. This bioinformatic procedure leads to a total list of 1948 candidate sRNAs. The size of the candidate list is strictly related to the aim of the study and to the technology used during the verification process. We provide performance measures of the algorithm in identifying annotated sRNAs reported in three recent published studies

    The relationship between self-awareness of attentional status, behavioral performance and oscillatory brain rhythms

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    High-level cognitive factors, including self-awareness, are believed to play an important role in human visual perception. The principal aim of this study was to determine whether oscillatory brain rhythms play a role in the neural processes involved in self-monitoring attentional status. To do so we measured cortical activity using magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) while participants were asked to self-monitor their internal status, only initiating the presentation of a stimulus when they perceived their attentional focus to be maximal. We employed a hierarchical Bayesian method that uses fMRI results as soft-constrained spatial information to solve the MEG inverse problem, allowing us to estimate cortical currents in the order of millimeters and milliseconds. Our results show that, during self-monitoring of internal status, there was a sustained decrease in power within the 7-13 Hz (alpha) range in the rostral cingulate motor area (rCMA) on the human medial wall, beginning approximately 430 msec after the trial start (p < 0.05, FDR corrected). We also show that gamma-band power (41-47 Hz) within this area was positively correlated with task performance from 40-640 msec after the trial start (r = 0.71, p < 0.05). We conclude: (1) the rCMA is involved in processes governing self-monitoring of internal status; and (2) the qualitative differences between alpha and gamma activity are reflective of their different roles in self-monitoring internal states. We suggest that alpha suppression may reflect a strengthening of top-down interareal connections, while a positive correlation between gamma activity and task performance indicates that gamma may play an important role in guiding visuomotor behavior. © 2013 Yamagishi et al

    Mode of Effective Connectivity within a Putative Neural Network Differentiates Moral Cognitions Related to Care and Justice Ethics

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    BACKGROUND: Moral sensitivity refers to the interpretive awareness of moral conflict and can be justice or care oriented. Justice ethics is associated primarily with human rights and the application of moral rules, whereas care ethics is related to human needs and a situational approach involving social emotions. Among the core brain regions involved in moral issue processing are: medial prefrontal cortex, anterior (ACC) and posterior (PCC) cingulate cortex, posterior superior temporal sulcus (pSTS), insula and amygdala. This study sought to inform the long standing debate of whether care and justice moral ethics represent one or two different forms of cognition. METHODOLOGY/PRINCIPAL FINDINGS: Model-free and model-based connectivity analysis were used to identify functional neural networks underlying care and justice ethics for a moral sensitivity task. In addition to modest differences in patterns of associated neural activity, distinct modes of functional and effective connectivity were observed for moral sensitivity for care and justice issues that were modulated by individual variation in moral ability. CONCLUSIONS/SIGNIFICANCE: These results support a neurobiological differentiation between care and justice ethics and suggest that human moral behavior reflects the outcome of integrating opposing rule-based, self-other perspectives, and emotional responses

    Is That Me or My Twin? Lack of Self-Face Recognition Advantage in Identical Twins

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    Despite the increasing interest in twin studies and the stunning amount of research on face recognition, the ability of adult identical twins to discriminate their own faces from those of their co-twins has been scarcely investigated. One’s own face is the most distinctive feature of the bodily self, and people typically show a clear advantage in recognizing their own face even more than other very familiar identities. Given the very high level of resemblance of their faces, monozygotic twins represent a unique model for exploring self-face processing. Herein we examined the ability of monozygotic twins to distinguish their own face from the face of their co-twin and of a highly familiar individual. Results show that twins equally recognize their own face and their twin’s face. This lack of self-face advantage was negatively predicted by how much they felt physically similar to their co-twin and by their anxious or avoidant attachment style. We speculate that in monozygotic twins, the visual representation of the self-face overlaps with that of the co-twin. Thus, to distinguish the self from the co-twin, monozygotic twins have to rely much more than control participants on the multisensory integration processes upon which the sense of bodily self is based. Moreover, in keeping with the notion that attachment style influences perception of self and significant others, we propose that the observed self/co-twin confusion may depend upon insecure attachment
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