408 research outputs found

    Newborns discriminate novel from harmonic sounds: a study using magnetoencephalography

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    Objective: We investigated whether newborns respond differently to novel and deviant sounds during quiet sleep. Methods: Twelve healthy neonates were presented with a three-stimulus oddball paradigm, consisting of frequent standard (76%), infrequent deviant (12%), and infrequent novel stimuli (12%). The standards and deviants were counterbalanced between the newborns and consisted of 500 and 750 Hz tones with two upper harmonics. The novel stimuli contained animal, human, and mechanical sounds. All stimuli had a duration of 300 ms and the stimulus onset asynchrony was 1 s. Evoked magnetic responses during quiet sleep were recorded and averaged offline. Results: Two deflections peaking at 345 and 615 ms after stimulus onset were observed in the evoked responses of most of the newborns. The first deflection was larger to novel and deviant stimuli than to the standard and, furthermore, larger to novel than to deviant stimuli. The second deflection was larger to novel and deviant stimuli than to standards, but did not differ between the novels and deviants. Conclusions: The two deflections found in the present study reflect different mechanisms of auditory change detection and discriminative processes. Significance: The early brain indicators of novelty detection may be crucial in assessing the normal and abnormal cortical function in newborns. Further, studying evoked magnetic fields to complex auditory stimulation in healthy newborns is needed for studying the newborns at-risk for cognitive or language problems

    Simulation of Efficient Real-Time Scheduling and Power Optimisation

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    International audienceSophisticated applications turn out to be executed upon more than one CPU for practical and economic reasons. Due to advances in circuit technology and performance limitation, multi-core technology has become the mainstream in CPU designs. However, the most serious limitation of these devices is the battery lifetime since battery technology is not keeping up with the rest of the power-hungry processors and peripherals used in today's mobile devices. As a solution, many investigations have turned toward the algorithms of power management combined with some scheduling policies. They can make significant energy saving while preserving the temporal constraints of these embedded systems. Reducing energy, especially, affect not only the battery lifetime, but also aim to reduce the heat generated by real-time embedded controller in various products or even to decrease the conditions of cooling and the costs, in the large scale, of giant multiprocessor computers. To assess the behavior and performance of the strategy of scheduling a flexible multiprocessor scheduling simulation and evaluation platform is needed. This paper puts forth the claim that the STORM simulator improves application quality both in terms of execution time and energy consumption for a high performance mobile computing embedded system design

    In silico characterization and evolution studies of alcohol dehydrogenase gene from Phoenix dactylifera L.cv Deglet Nour

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    The aim of our study was to isolate the alcohol dehydrogenase (ADH) mRNA from Phoenix dactifera, and examine the molecular evolutionary history of this nuclear gene with others ADH genes from palms and other plants species. The DnADH gene has been isolated in silico by BLAST2GO from a cDNA library of date palm cv Deglet Nour. The prediction of candidate’s mRNA and protein for ADH gene from khalas were performed in silico from whole genome shotgun sequence (ACYX02009373.1) using FGENESH prediction program. Nucleotide polymorphism using DnaSPv5 was examined in four palm ADH mRNA sequences across the entire 1.098 kb length of ADH mRNA. A primary conclusion of the present study is that nucleotide diversity for ADH between palm species is very low. In order to assess selective pressure, we calculated the ratio of non-synonymous to synonymous substitutions. We conclude that ADH palms genes appear to be under very different selective constraints. Phylogenetic analyses using PHYLIP and Notung 2.8 programs suggest that ADH genes of some plants species resulted from relatively ancient duplication events. In this study, we present for the first time a molecular characterization of ADH protein of P. dactylifera L cv Deglet nour and a phylogeny analysis between plants ADH.Keys word: Alcohol dehydrogenase, palms species, evolution, duplication

    Detecting violations of temporal regularities in waking and sleeping two-month-old infants

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    Correctly processing rapid sequences of sounds is essential for developmental milestones, such as language acquisition. We investigated the sensitivity of two-month-old infants to violations of a temporal regularity, by recording event-related brain potentials (ERP) in an auditory oddball paradigm from 36 waking and 40 sleeping infants. Standard tones were presented at a regular 300 ms inter-stimulus interval (ISI). One deviant, otherwise identical to the standard, was preceded by a 100 ms ISI. Two other deviants, presented with the standard ISI, differed from the standard in their spectral makeup. We found significant differences between ERP responses elicited by the standard and each of the deviant sounds. The results suggest that the ability to extract both temporal and spectral regularities from a sound sequence is already functional within the first few months of life. The scalp distribution of all three deviant-stimulus responses was influenced by the infants‟ state of alertness

    Processing acoustic change and novelty in newborn infants

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    Research on event-related potential (ERP) correlates of auditory deviance-detection in newborns provided inconsistent results; temporal and topographic ERP characteristics differed widely across studies and individual infants. Robust and reliable ERP responses were, however, obtained to sounds (termed ‘novel’ sounds), which cover a wide range of frequencies and widely differ from the context provided by a repeating sound [Kushnerenko et al., (2002) NeuroReport, 13, 1843–1848]. The question we investigated here is whether this effect can be attributed to novelty per se or to acoustic characteristics of the ‘novel’ sounds, such as their wide frequency spectrum and high signal energy compared with the repeated tones. We also asked how sensitivity to these stimulus aspects changes with development. Twelve newborns and 11 adults were tested in four different oddball conditions, each including a ‘standard’ sound presented with the probability of 0.8 and two types of infrequent ‘deviant’ sounds (0.1 probability, each). Deviants were (i) ‘novel’ sounds (diverse environmental noises); (ii) white-noise segments, or harmonic tones of (iii) a higher pitch, or (iv) higher intensity. In newborns, white-noise deviants elicited the largest response in all latency ranges, whereas in adults, this phenomenon was not found. Thus, newborns appear to be especially sensitive to sounds having a wide frequency spectrum. On the other hand, the pattern of results found for the late discriminative ERP response indicates that newborns may also be able to detect novelty in acoustic stimulation, although with a longer latency than adults, as shown by the ERP response. Results are discussed in terms of developmental refinement of the initially broadly tuned neonate auditory system

    Saliency or template? ERP evidence for long-term representation of word stress

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    The present study investigated the event-related brain potential (ERP) correlates of word stress processing. Previous results showed that the violation of a legal stress pattern elicited two consecutive Mismatch Negativity (MMN) components synchronized to the changes on the first and second syllable. The aim of the present study was to test whether ERPs reflect only the detection of salient features present on the syllables, or they reflect the activation of long-term stress related representations. We examined ERPs elicited by pseudowords with no lexical representation in two conditions: the standard having a legal stress patterns, and the deviant an illegal one, and the standard having an illegal stress pattern, and the deviant a legal one. We found that the deviant having an illegal stress pattern elicited two consecutive MMN components, whereas the deviant having a legal stress pattern did not elicit MMN. Moreover, pseudowords with a legal stress pattern elicited the same ERP responses irrespective of their role in the oddball sequence, i.e., if they were standards or deviants. The results suggest that stress pattern changes are processed relying on long-term representation of word stress. To account for these results, we propose that the processing of stress cues is based on language-specific, pre-lexical stress templates

    Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review

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    Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the “cognitive training-soccer performance” relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7-39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) have a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery, and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practicing complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players

    Ischemic cardiomyopathy revealed by central retinal artery occlusion (CRAO)

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    Here we report a case of central retinal artery occlusionrevealing an ischemic cardiomyopathy. A 54-year old smoker man presented at the hospital because of sudden visual loss in his left eye. There was cherry-red spot in the macula in his left eye. We performed a fluorescein angiogram and cervical color Doppler. Later   investigations revealed an ischemic cardiomyopathy undiagnosed until then.Key words: Central retinal artery occlusion, ischemic cardiomyopathy, cardiac thrombu
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