Articles de revues : « SPONTANEOUS INTERACTIONS »

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Cuadros, Zamara, Esteban Hurtado et Carlos Cornejo. « Infant-adult synchrony in spontaneous and nonspontaneous interactions ». PLOS ONE 15, n^o 12 (18 décembre 2020) : e0244138. http://dx.doi.org/10.1371/journal.pone.0244138.

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Infant-adult synchrony has been reported through observational and experimental studies. Nevertheless, synchrony is addressed differently in both cases. While observational studies measure synchrony in spontaneous infant-adult interactions, experimental studies manipulate it, inducing nonspontaneous synchronous and asynchronous interactions. A still unsolved question is to what extent differ spontaneous synchrony from the nonspontaneous one, experimentally elicited. To address this question, we conducted a study to compare synchrony in both interactional contexts. Forty-three 14-month-old infants were randomly assigned to one of two independent groups: (1) the spontaneous interaction context, consisting of a storytime session; and (2) the nonspontaneous interaction context, where an assistant bounced the infant in synchrony with a stranger. We employed an optical motion capture system to accurately track the time and form of synchrony in both contexts. Our findings indicate that synchrony arising in spontaneous exchanges has different traits than synchrony produced in a nonspontaneous interplay. The evidence presented here offers new insights for rethinking the study of infant-adult synchrony and its consequences on child development.

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Li, Chang, et Hideyoshi Yanagisawa. « Intrinsic motivation in virtual assistant interaction for fostering spontaneous interactions ». PLOS ONE 16, n^o 4 (23 avril 2021) : e0250326. http://dx.doi.org/10.1371/journal.pone.0250326.

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With the growing utility of today’s conversational virtual assistants, the importance of user motivation in human–artificial intelligence interactions is becoming more obvious. However, previous studies in this and related fields, such as human–computer interaction, scarcely discussed intrinsic motivation (the motivation to interact with the assistants for fun). Previous studies either treated motivation as an inseparable concept or focused on non-intrinsic motivation (the motivation to interact with the assistant for utilitarian purposes). The current study aims to cover intrinsic motivation by taking an affective engineering approach. A novel motivation model is proposed, in which intrinsic motivation is affected by two factors that derive from user interactions with virtual assistants: expectation of capability and uncertainty. Experiments in which these two factors are manipulated by making participants believe they are interacting with the smart speaker “Amazon Echo” are conducted. Intrinsic motivation is measured both by using questionnaires and by covertly monitoring a five-minute free-choice period in the experimenter’s absence, during which the participants could decide for themselves whether to interact with the virtual assistants. Results of the first experiment showed that high expectation engenders more intrinsically motivated interaction compared with low expectation. However, the results did not support our hypothesis that expectation and uncertainty have an interaction effect on intrinsic motivation. We then revised our hypothetical model of action selection accordingly and conducted a verification experiment of the effects of uncertainty. Results of the verification experiment showed that reducing uncertainty encourages more interactions and causes the motivation behind these interactions to shift from non-intrinsic to intrinsic.

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Altschul, B., et V. Alan Kostelecký. « Spontaneous Lorentz violation and nonpolynomial interactions ». Physics Letters B 628, n^o 1-2 (novembre 2005) : 106–12. http://dx.doi.org/10.1016/j.physletb.2005.09.018.

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Chon, Ki H., Ramakrishna Raghavan, Yu-Ming Chen, Donald J. Marsh et Kay-Pong Yip. « Interactions of TGF-dependent and myogenic oscillations in tubular pressure ». American Journal of Physiology-Renal Physiology 288, n^o 2 (février 2005) : F298—F307. http://dx.doi.org/10.1152/ajprenal.00164.2004.

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We have previously shown that there are two oscillating components in spontaneously fluctuating single-nephron blood flow obtained from Sprague-Dawley rats (Yip K-P, Holstein-Rathlou NH, and Marsh DJ. Am J Physiol Renal Physiol 264: F427–F434, 1993). The slow oscillation (20–30 mHz) is mediated by tubuloglomerular feedback (TGF), whereas the fast oscillation (100 mHz) is probably related to spontaneous myogenic activity. The fast oscillation is rarely detected in spontaneous tubular pressure because of its small magnitude and the fact that tubular compliance filters pressure waves. We detected myogenic oscillation superimposed on TGF-mediated oscillation when ambient tubular flow was interrupted. Two well-defined peaks are present in the mean power spectrum of stop-flow pressure (SFP) centering at 25 and 100 mHz ( n = 13), in addition to a small peak at 125–130 mHz. Bispectral analysis indicates that two of these oscillations (30 and 100 mHz) interact nonlinearly to produce the third oscillation at 125–130 mHz. The presence of nonlinear interactions between TGF and myogenic oscillations indicates that estimates of the relative contribution of each of these mechanisms in renal autoregulation need to account for this interaction. The magnitude of myogenic oscillations was considerably smaller in the SFP measured from spontaneously hypertensive rats (SHR, n = 13); consequently, nonlinear interactions were not observed with bispectral analysis. Reduced augmentation of myogenic oscillations in SFP of SHR might account for the failure in detecting nonlinear interactions in SHR.

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Mudoor Sooresh, Maanasa, Benjamin P. Willing et Benjamin C. T. Bourrie. « Opportunities and Challenges of Understanding Community Assembly in Spontaneous Food Fermentation ». Foods 12, n^o 3 (3 février 2023) : 673. http://dx.doi.org/10.3390/foods12030673.

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Spontaneous fermentations that do not rely on backslopping or industrial starter cultures were especially important to the early development of society and are still practiced around the world today. While current literature on spontaneous fermentations is observational and descriptive, it is important to understand the underlying mechanism of microbial community assembly and how this correlates with changes observed in microbial succession, composition, interaction, and metabolite production. Spontaneous food and beverage fermentations are home to autochthonous bacteria and fungi that are naturally inoculated from raw materials, environment, and equipment. This review discusses the factors that play an important role in microbial community assembly, particularly focusing on commonly reported yeasts and bacteria isolated from spontaneously fermenting food and beverages, and how this affects the fermentation dynamics. A wide range of studies have been conducted in spontaneously fermented foods that highlight some of the mechanisms that are involved in microbial interactions, niche adaptation, and lifestyle of these microorganisms. Moreover, we will also highlight how controlled culture experiments provide greater insight into understanding microbial interactions, a modest attempt in decoding the complexity of spontaneous fermentations. Further research using specific in vitro microbial models to understand the role of core microbiota are needed to fill the knowledge gap that currently exists in understanding how the phenotypic and genotypic expression of these microorganisms aid in their successful adaptation and shape fermentation outcomes. Furthermore, there is still a vast opportunity to understand strain level implications on community assembly. Translating these findings will also help in improving other fermentation systems to help gain more control over the fermentation process and maintain consistent and superior product quality.

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Bauminger-Zviely, Nirit, et Analia Shefer. « Naturalistic evaluation of preschoolers’ spontaneous interactions : The Autism Peer Interaction Observation Scale ». Autism 25, n^o 6 (24 février 2021) : 1520–35. http://dx.doi.org/10.1177/1362361321989919.

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Peer interaction can be challenging in autism spectrum disorder, but naturalistic peer-observation scales for preschoolers are scarce. This study examined psychometric qualities of the newly developed Autism Peer Interaction Observation Scale. We tested the Autism Peer Interaction Observation Scale to (a) characterize peer interactions of preschoolers with autism spectrum disorder who were cognitively able versus typical age-mates, (b) explore each group’s hierarchical pattern of peer interaction behaviors, and (c) identify Autism Peer Interaction Observation Scale’s links with standard reports for assessing social-communication functioning (Vineland Behavior Scales, 2nd ed.), social impairment (Social Responsiveness Scale, 2nd ed.), autism severity (Autism Diagnostic Observation Schedule, 2nd ed.), and intelligence quotient (Mullen) in the cognitively able preschoolers with autism spectrum disorder group. Participants comprised 85 preschoolers (50 cognitively able preschoolers with autism spectrum disorder, intelligence quotient > 75; 35 typical). Groups were matched for age, intelligence quotient, and maternal education. Significant group differences emerged on all Autism Peer Interaction Observation Scale categories, in favor of typical. In cognitively able preschoolers with autism spectrum disorder, correlation analyses indicated that more typical peer relations on Autism Peer Interaction Observation Scale were linked with better adaptive and socialization skills (Vineland Behavior Scales, 2nd ed.) and fewer social atypicalities (Social Responsiveness Scale, 2nd ed.). Higher intelligence quotient scores were linked with better Autism Peer Interaction Observation Scale social-communication functioning. Only a few Autism Peer Interaction Observation Scale social-communication categories significantly correlated with the Autism Diagnostic Observation Schedule, 2nd ed. Findings highlight the Autism Peer Interaction Observation Scale as differentiating between groups and providing knowledge about peer interaction in natural settings. This new tool can help personalize social-communication programs and evaluations of early intervention outcomes. Lay abstract Peer interaction can be challenging in autism spectrum disorder, but naturalistic peer-observation scales for preschoolers are limited. This study examined the newly developed Autism Peer Interaction Observation Scale, with 17 subcategories, which evaluate naturalistic peer interaction processes in preschoolers with autism spectrum disorder and typical development. We tested the Autism Peer Interaction Observation Scale to (a) characterize peer interactions of preschoolers with autism spectrum disorder who were cognitively able versus typical age-mates, (b) explore each group’s hierarchical pattern of peer interaction behaviors, and (c) identify Autism Peer Interaction Observation Scale’s links with standard reports for assessing social-communication functioning (Vineland Behavior Scales, 2nd ed.), social impairment (Social Responsiveness Scale, 2nd ed.), autism severity (Autism Diagnostic Observation Schedule, 2nd ed.), and intelligence quotient (Mullen) in the cognitively able preschoolers with autism spectrum disorder group. Participants comprised 85 preschoolers (50 cognitively able preschoolers with autism spectrum disorder, intelligence quotient > 75; 35 typical). Groups were matched according to age, intelligence quotient, and maternal education. Significant group differences emerged on all Autism Peer Interaction Observation Scale categories, with the typical group showing better social-communication functioning as compared to the cognitively able preschoolers with autism spectrum disorder group. Also, in cognitively able preschoolers with autism spectrum disorder that observed as demonstrating more typical peer relations on the Autism Peer Interaction Observation Scale showed better adaptive and socialization skills on the Vineland (Vineland Behavior Scales, 2nd ed.) and fewer social atypicalities on the Social Responsiveness Scale, 2nd ed. Higher intelligence quotient scores were linked with better observed social-communication functioning (on Autism Peer Interaction Observation Scale). Few Autism Peer Interaction Observation Scale social-communicative categories significantly correlated with the Autism Diagnostic Observation Schedule, 2nd ed. Findings highlight the Autism Peer Interaction Observation Scale as differentiating the two preschooler groups and providing additional knowledge about socially communicative peer interaction in natural settings. This new tool can help personalize social-communication programs and evaluations of early intervention outcomes, thereby leading to a fuller picture of these young children’s functioning.

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Uhnoo, Sara, et Sofia Persson. « Emotion management of disaster volunteers : the delicate balance between control and recognition ». Emotions and Society 2, n^o 2 (1 novembre 2020) : 197–213. http://dx.doi.org/10.1332/263169020x15996504158224.

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Authorities always need help in disaster situations, and in line with the current trend of community resilience, they see support from active citizens as a promising solution. However, the uncontrolled inflow of spontaneous volunteers and other resources into a disaster area poses serious dilemmas for professional responders. The uniqueness of this study lies in its approach to authorities’ management of spontaneous volunteers from the perspective of the sociology of emotions. Drawing on an interactionist perspective of emotions, the objective is to deepen our understanding of how and why professional responders use interpersonal emotion management in interactions with spontaneous volunteers during disasters. We discuss this issue in relation to a specific disaster operation. Building on findings from interviews with personnel from the fire and rescue services, key officials and volunteers involved in the management of a large-scale forest fire in Sweden, we show that professionals’ emotion management in interactions with volunteers requires a balance between the control and recognition of volunteer activities. Specific emotion management techniques and an overarching rule about expressing gratitude to spontaneous volunteers are identified and discussed in relation to the professionals’ rationale for their emotion management. We argue that emotion management is a crucial aspect of the interaction between professionals and volunteers, with important implications for disaster management and the legitimacy of the authorities in the eyes of citizens.

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LI, BING AN. « THEORY OF ELECTROWEAK INTERACTIONS WITHOUT SPONTANEOUS SYMMETRY BREAKING ». International Journal of Modern Physics A 16, n^o 25 (10 octobre 2001) : 4171–88. http://dx.doi.org/10.1142/s0217751x01005341.

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An electroweak theory without spontaneous symmetry breaking is studied in this paper. A new symmetry breaking of SU (2)L × U (1), axial-vector symmetry breaking, caused by the combination of the axial-vector component of the intermediate boson and the fermion mass is found in electroweak theory. The mass of the W boson is resulted in the combination of the axial-vector symmetry breaking and the explicit symmetry breaking by the fermion masses. The Z boson gains mass from the axial-vector symmetry breaking only. [Formula: see text], [Formula: see text], and [Formula: see text] are obtained. They are in excellent agreement with data. The SU (2)L × U (1) invariant generating functional of the Green functions is constructed and the theory is proved to be renormalizable.

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Sodt, Alexander J., Richard M. Venable, Edward Lyman et Richard W. Pastor. « Lipid-Lipid Interactions Determine the Membrane Spontaneous Curvature ». Biophysical Journal 108, n^o 2 (janvier 2015) : 181a. http://dx.doi.org/10.1016/j.bpj.2014.11.1002.

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Szefler, Beata, et Przemysław Czeleń. « Will the Interactions of Some Platinum (II)-Based Drugs with B-Vitamins Reduce Their Therapeutic Effect in Cancer Patients ? Comparison of Chemotherapeutic Agents such as Cisplatin, Carboplatin and Oxaliplatin—A review ». International Journal of Molecular Sciences 24, n^o 2 (12 janvier 2023) : 1548. http://dx.doi.org/10.3390/ijms24021548.

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Pt (II) derivatives show anti-cancer activity by interacting with nucleobases of DNA, thus causing some spontaneous and non-spontaneous reactions. As a result, mono- and diaqua products are formed which further undergo complexation with guanine or adenine. Consequently, many processes are triggered, which lead to the death of the cancer cell. The theoretical and experimental studies confirm that such types of interactions can also occur with other chemical compounds. The vitamins from B group have a similar structure to the nucleobases of DNA and have aromatic rings with single-pair orbitals. Theoretical and experimental studies were performed to describe the interactions of B vitamins with Pt (II) derivatives such as cisplatin, oxaliplatin and carboplatin. The obtained results were compared with the values for guanine. Two levels of simulations were implemented at the theoretical level, namely, B3LYP/6-31G(d,p) with LANL2DZ bases set for platinum atoms and MN15/def2-TZVP. The polarizable continuum model (IEF–PCM preparation) and water as a solvent were used. UV-Vis spectroscopy was used to describe the drug–nucleobase and drug–B vitamin interactions. Values of the free energy (ΔGr) show spontaneous reactions with mono- and diaqua derivatives of cisplatin and oxaliplatin; however, interactions with diaqua derivatives are more preferable. The strength of these interactions was also compared. Carboplatin products have the weakest interaction with the studied structures. The presence of non-covalent interactions was demonstrated in the tested complexes. A good agreement between theory and experiment was also demonstrated.

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VANDERBILT, DAVID. « ORDERING AT SURFACES FROM ELASTIC AND ELECTROSTATIC INTERACTIONS ». Surface Review and Letters 04, n^o 05 (octobre 1997) : 811–16. http://dx.doi.org/10.1142/s0218625x9700081x.

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Elastic and electrostatic interactions can sometimes have a profound influence on surface morphology. Here, we review the conditions under which surface stress or surface dipole variations can give rise to spontaneous domain formation at surfaces, and focus especially on the case of the Si(100) surface. In principle, the anisotropy of the surface stress should cause the spontaneous formation of a striped domain structure on Si(100). In practice, the length scale for this domain structure turns out to be so large as to prevent its direct observation, although the influence of the elastic interactions has been observed indirectly in a variety of related experiments. It is now evident that by introducing Ge or B atoms, the conditions can be tuned in such a way that the spontaneous domain formation is strikingly observed. Because surface electrostatic dipolar interactions scale in the same way as elastic ones, it follows that similar effects can arise from these sources. We consider a simple model two-phase surface system with 1/r3 dipolar interactions, and find that the model exhibits spontaneous formation of two kinds of periodic domain structure. A striped domain structure is stable near half-filling, but as the area fraction is changed, a transition to a hexagonal lattice of almost-circular droplets occurs. The relation of this model to experimental surface systems, especially that of Langmuir layers at the water–air interface, will be discussed.

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Omer, Omer Ahmed, et Nadra Abd Allah Ali. « The Impact of E-learning on Virtual Class Interactions : A Case Study of French Virtual Class Interactions ». Journal of Humanities and Social Sciences Studies 3, n^o 11 (30 novembre 2021) : 133–40. http://dx.doi.org/10.32996/jhsss.2021.3.11.12.

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The current qualitative study aims at exploring and analyzing in a descriptive way the impact of e-learning on different interactions forms in French virtual class in order to strengthen the students’ engagement in this type of class. The problem that we encounter when it comes to French virtual class is the lack of spontaneous and active interactions which could negatively affect the learning process. The study was based on data collected from structured observations conducted throughout the 2nd semester 2020/2021. The results show that the general interaction rate is unsatisfactory; especially the peers’ interaction rate which is the worst. To enhance the virtual class interactions, some tips and practices have been recommended. A further study may help to identify the factors that affect the interactions in virtual class.

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Bhat, G., S. M. Williams, G. R. Saade et Ramkumar Menon. « Biomarker Interactions Are Better Predictors of Spontaneous Preterm Birth ». Reproductive Sciences 21, n^o 3 (24 juillet 2013) : 340–50. http://dx.doi.org/10.1177/1933719113497285.

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Wießner, R. M., A. Fledderjohann, K. H. Mütter et M. Karbach. « Spontaneous magnetization in spin-ladder systems with competing interactions ». Physical Review B 60, n^o 9 (1 septembre 1999) : 6545–51. http://dx.doi.org/10.1103/physrevb.60.6545.

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Sims, Cynthia, Marjorie Romkes, Richard D. Day, Tomoko Nukui, Gail F. Harger, Nina Markovic, W. Allen Hogge, Roberta B. Ness et William L. Bigbee. « 518 Maternal gene-environment interactions and spontaneous abortion risk ». American Journal of Obstetrics and Gynecology 185, n^o 6 (décembre 2001) : S222. http://dx.doi.org/10.1016/s0002-9378(01)80550-0.

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Ponce-Alvarez, A. « Spontaneous transient synchronization networks emerge from large-scale interactions ». Clinical Neurophysiology 127, n^o 3 (mars 2016) : e48. http://dx.doi.org/10.1016/j.clinph.2015.11.157.

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Griffiths, J. F., et S. K. Scott. « Thermokinetic interactions : Fundamentals of spontaneous ignition and cool flames ». Progress in Energy and Combustion Science 13, n^o 3 (janvier 1987) : 161–97. http://dx.doi.org/10.1016/0360-1285(87)90010-4.

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Giudice, E. del, S. Doglia, M. Milani et G. Vitiello. « Spontaneous symmetry breaking and electromagnetic interactions in biological systems ». Physica Scripta 38, n^o 3 (1 septembre 1988) : 505–7. http://dx.doi.org/10.1088/0031-8949/38/3/032.

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Mackay, Trudy F. C., et James D. Fry. « Polygenic Mutation in Drosophila melanogaster : Genetic Interactions Between Selection Lines and Candidate Quantitative Trait Loci ». Genetics 144, n^o 2 (1 octobre 1996) : 671–88. http://dx.doi.org/10.1093/genetics/144.2.671.

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Abstract We have investigated genetic interactions between spontaneous mutations affecting abdominal and sternopleural bristle number that have accumulated in 12 long-term selection lines derived from an inbred strain, and mutations at 14 candidate bristle number quantitative trait loci. The quantitative test for complementation was to cross the selection lines to an inbred wild-type strain (the control cross) and to a derivative of the control strain into which the mutant allele at the candidate locus to be tested was substituted (the tester strain). Genetic interactions between spontaneous mutations affecting bristle number and the candidate locus mutations were common, and in several cases the interaction effects were different in males and females. Analyses of variance of the (tester – control) differences among and within groups of replicate lines selected in the same direction for the same trait showed significant group effects for several candidate loci. Genetically, the interactions could be caused by allelism of, and/or epistasis between, spontaneous mutations in the selection lines and the candidate locus mutations. It is possible that much of the response to selection was from new mutations at candidate bristle number quantitative trait loci, and that for some of these loci, mutation rates were high.

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Amadori, A., R. Zamarchi, M. L. Veronese, M. Panozzo, A. Barelli, A. Borri, M. Sironi, F. Colotta, A. Mantovani et L. Chieco-Bianchi. « B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement. » Journal of Immunology 146, n^o 1 (1 janvier 1991) : 57–62. http://dx.doi.org/10.4049/jimmunol.146.1.57.

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Abstract This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

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Watanabe, Takeshi, Makoto Iima et Yasumasa Nishiura. « Spontaneous formation of travelling localized structures and their asymptotic behaviour in binary fluid convection ». Journal of Fluid Mechanics 712 (28 septembre 2012) : 219–43. http://dx.doi.org/10.1017/jfm.2012.413.

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AbstractWe study spontaneous pattern formation and its asymptotic behaviour in binary fluid flow driven by a temperature gradient. When the conductive state is unstable and the size of the domain is large enough, finitely many spatially localized time-periodic travelling pulses (PTPs), each containing a certain number of convection cells, are generated spontaneously in the conductive state and are finally arranged at non-uniform intervals while moving in the same direction. We found that the role of PTP solutions and their strong interactions (collision) are important in characterizing the asymptotic state. Detailed investigations of pulse–pulse interactions showed the differences in asymptotic behaviour between that in a finite but large domain and in an infinite domain.

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MILDENBERGER, CARL DAVID. « Spontaneous disorder : conflict-kindling institutions in virtual worlds ». Journal of Institutional Economics 14, n^o 5 (11 octobre 2017) : 787–809. http://dx.doi.org/10.1017/s1744137417000492.

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AbstractThis paper analyses the emergence and persistence of disorder due to bellicose (i.e. ‘conflict-kindling’) institutions. It does so relying on a novel empirical approach, examining the predatory and productive interactions of 400,000 users of a virtual world as well as its institutions. The paper finds that while there are many cases of spontaneous order in that virtual world, and while the users are not more conflict-loving as such, bellicose institutions sanctioning suicidal attacks in a supposedly safe region spontaneously emerged and rigidly persist, thus upholding disorder (i.e. a particularly violent kind of ordered anarchy).

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Liljenström, Hans. « Interscale interactions in cortical neural networks ». Behavioral and Brain Sciences 23, n^o 3 (juin 2000) : 408–9. http://dx.doi.org/10.1017/s0140525x00323251.

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This commentary focuses on how the large-scale cortical dynamics described in Nunez's target article are related to various phenomena at different scales, both spatial and temporal, in particular, how the brain dynamics measured with EEG could relate to (i) experience and mental state, (ii) neuromodulatory effects, and (iii) spontaneous firing and autogenerated electromagnetic effects.

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Repp, Bruno H. « Pattern Typicality and Dimensional Interactions in Pianists' Imitation of Expressive Timing and Dynamics ». Music Perception 18, n^o 2 (2000) : 173–211. http://dx.doi.org/10.2307/40285908.

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Success in an imitation task may be defined in absolute terms (how well the reproduction matches the model) or in relative terms (how much better the reproduction matches the model than the imitator's spontaneous production matches the model). In the present study of expressive music performance, it was hypothesized that absolute imitation success would decrease but relative imitation success would increase as the model pattern diverges more and more from the typical pattern of spontaneous production, within reasonable limits. This hypothesis received support in Experiment 1, which required pianists first to play a musical excerpt spontaneously and then to imitate model performances instantiating different patterns of expressive timing or dynamics, with the other dimension held constant at a typical pattern. The typical expressive pattern for a given musical passage seems to function as a cognitive schema that biases perception, memory, and (re) production of expressive nuances. The results also suggested that imitation of different dynamic patterns affects expressive timing (louder tones were followed by longer interonset intervals), whereas imitation of different timing patterns had little effect on produced dynamics. The latter findings were replicated in Experiment 2, which presented models that differed in both timing and dynamics. Attention to both dimensions simultaneously also reduced imitation accuracy, especially for timing.

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Kiener, Peter A., Patricia M. Davis, Gary C. Starling, Christopher Mehlin, Seymour J. Klebanoff, Jeffrey A. Ledbetter et W. Conrad Liles. « Differential Induction of Apoptosis by Fas–Fas Ligand Interactions in Human Monocytes and Macrophages ». Journal of Experimental Medicine 185, n^o 8 (21 avril 1997) : 1511–16. http://dx.doi.org/10.1084/jem.185.8.1511.

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Human monocytes undergo spontaneous apoptosis upon culture in vitro; removal of serum from the media dramatically increases the rate of this process. Monocyte apoptosis can be significantly abrogated by the addition of growth factors or proinflammatory mediators. We have evaluated the role of the endogenous Fas–Fas ligand (FasL) interaction in the induction of this spontaneous apoptosis and found that a Fas–immunoglobulin (Ig) fusion protein, an antagonistic anti-Fas monoclonal antibody and a rabbit anti-FasL antibody all greatly reduced the onset of apoptosis. The results indicate that spontaneous death of monocytes is mediated via an autocrine or paracrine pathway. Treatment of the cells with growth factors or cytokines that prevented spontaneous apoptosis had no major effects on the expression of Fas or FasL. Additionally, monocyte-derived macrophages were found to express both Fas and FasL but did not undergo spontaneous apoptosis and were not sensitive to stimulation by an agonistic anti-Fas IgM. These results indicate that protective mechanisms in these cells exist at a site downstream of the receptor–ligand interaction.

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FIRTH, SALLY I., et MARLA B. FELLER. « Dissociated GABAergic retinal interneurons exhibit spontaneous increases in intracellular calcium ». Visual Neuroscience 23, n^o 5 (septembre 2006) : 807–14. http://dx.doi.org/10.1017/s095252380623013x.

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Early in development, before the retina is responsive to light, neurons exhibit spontaneous activity. Recently it was demonstrated that starburst amacrine cells, a unique class of neurons that secretes both GABA and acetylcholine, spontaneously depolarize. Networks comprised of spontaneously active starburst cells initiate correlated bursts of action potentials that propagate across the developing retina with a periodicity on the order minutes. To determine whether other retinal interneurons have similar “pacemaking” properties, we have utilized cultures of dissociated neurons from the rat retina. In the presence of antagonists for fast neurotransmitter receptors, distinct populations of neurons exhibited spontaneous, uncorrelated increases in intracellular calcium concentration. These increases in intracellular calcium concentration were sensitive to tetrodotoxin, indicating they are mediated by spontaneous membrane depolarizations. By combining immunofluorescence and calcium imaging, we found that 44% of spontaneously active neurons were GABAergic and included starburst amacrine cells. Whole cell voltage clamp recordings in the absence of antagonists for fast neurotransmitters revealed that after 7 days in culture, individual retinal neurons receive bursts of GABA-A receptor mediated synaptic input with a periodicity similar to that measured in spontaneously active GABAergic neurons. Low concentrations of GABA-A receptor antagonists did not alter the inter-burst interval despite significant reduction of post-synaptic current amplitude, indicating that pacemaker activity of GABAergic neurons was not influenced by network interactions. Together, these findings indicate that spiking GABAergic interneurons can function as pacemakers in the developing retina.

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Sukov, William, et Daniel S. Barth. « Three-Dimensional Analysis of Spontaneous and Thalamically Evoked Gamma Oscillations in Auditory Cortex ». Journal of Neurophysiology 79, n^o 6 (1 juin 1998) : 2875–84. http://dx.doi.org/10.1152/jn.1998.79.6.2875.

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Sukov, William and Daniel S. Barth. Three-dimensional analysis of spontaneous and thalamically evoked gamma oscillations in auditory cortex. J. Neurophysiol. 79: 2875–2884, 1998. The purpose of this study was to investigate interactions among laminar cell populations producing spontaneous and evoked high-frequency (∼40 Hz) gamma oscillations in auditory cortex. Electrocortical oscillations were recorded using a 64-channel epipial electrode array and a 16-channel linear laminar electrode array while electrical stimulation was delivered to the posterior intralaminar (PIL) nucleus. Spontaneous gamma oscillations, and those evoked by PIL stimulation, are confined to a location overlapping primary and secondary auditory cortex. Current source-density and principal components analysis of laminar recordings at this site indicate that the auditory evoked potential (AEP) complex is characterized by a stereotyped asynchronous activation of supra- and infragranular cell populations. Similar analysis of spontaneous and evoked gamma waves reveals a close spatiotemporal similarity to the laminar AEP, indicating rhythmic interactions between supra- and infragranular cell groups during these oscillatory phenomena. We conclude that neural circuit interactions producing the laminar AEP onset in auditory cortex are the same as those generating evoked and spontaneous gamma oscillations.

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Saito, Yasuhiko, et Tadashi Isa. « Organization of Interlaminar Interactions in the Rat Superior Colliculus ». Journal of Neurophysiology 93, n^o 5 (mai 2005) : 2898–907. http://dx.doi.org/10.1152/jn.01051.2004.

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Our previous studies have shown that when slices of the rat superior colliculus (SC) are exposed to a solution containing 10 μM bicuculline and a low concentration of Mg2+ (0.1 mM), most neurons in the intermediate gray layer (stratum griseum intermediale; SGI), wide-field vertical (WFV) cells in the optic layer (stratum opticum; SO), and a minor population of neurons in the superficial gray layer (stratum griseum superficiale; SGS) exhibit spontaneous depolarization and burst firing, which are synchronous among adjacent neurons. These spontaneous and synchronous depolarizations were thought to share common mechanisms with presaccadic burst activity in SGI neurons. In the present study, we explored the site responsible for generation of synchronous depolarization of SGI neurons by performing dual whole cell recordings under different slice conditions. A pair of SGI neurons recorded in a small rectangular piece of the SGI punched out from the SC slice showed synchronous depolarization but far less frequently than those recorded in a small rectangular piece including SGS and SO. This suggests that the superficial layers are needed for triggering synchronous depolarization in the SGI. Furthermore, we recorded spontaneous depolarizations in pairs of neurons belonging to the different layers. Analysis of their synchronicity revealed that WFV cells in the SO exhibit synchronous depolarizations with both SGS and SGI neurons, and the onset of spontaneous depolarization in WFV cells precedes those of neurons in other layers. Further, when SGS and SGI neurons exhibit synchronous depolarizations, SGI neurons usually precede the SGS neurons. These observations give further evidence to the existence of interlaminar interaction between superficial and deeper layers of the SC. In addition, it is suggested that WFV cells can trigger burst activity in other layers of the SC and that there is an excitatory signal transmission from the deeper layers to the superficial layers.

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Campo, Javier, Javier Luzon, Laura Cañadillas, Naoki Amaya, Fernando Palacio et Yuko Hosokoshi. « Purely organic magnets : How to get ferromagnetic interactions ». Acta Crystallographica Section A Foundations and Advances 70, a1 (5 août 2014) : C1085. http://dx.doi.org/10.1107/s2053273314089141.

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Purely organic magnets, materials with spontaneous magnetization despite no containing magnetic ions, are very promising for technological applications due to their peculiar properties as flexibility, lightness or even biocompatibility. Most of the published purely organic magnets are free radical compounds. One of the most important difficulties in order to get spontaneous magnetization in such materials is that magnetic interactions among free radicals are usually antiferromagnetic and, in addition, ferromagnetic interactions are weaker than the antiferromagnetic ones. A possible strategy to overcome this issue is the use of triradical molecules with total spin S=1/2. In this case, an adequate packing of the triradical molecules can give place to antiferromagnetic interactions between regions with positive spin density and regions with negative spin density of two close molecules. This antiferromagnetic interaction between regions with opposite spin density would result in an overall ferromagnetic interaction between the two close triradicals. With this idea in mind we have performed an study of the spin density distribution and of the intramolecular and intermolecular magnetic interactions of the triradical compound 2-[3',5'-bis(Ntert-butylaminoxyl)phenyl]-4,4,5,5-tetramethyl-4,5-dihydro-1-Himidazol-1-oxyl-3-oxide, containing two N-tert-butyl aminoxyls and a nitronyl nitroxide groups. Combination of experimental data from a polarized neutron diffraction experiment and ab initio calculations (DFT) has allowed us to obtain the spin density distribution. In addition, the intramolecular and intermolecular magnetic interactions have been computed by ab initio quantum chemistry methods. The values for the intramolecular interactions confirm the S=1/2 ground state of the triradical. As for the intermolecular interactions, the two strongest ones are ferromagnetic, what is in agreement with the overlapping of regions with opposite spin density of the two interacting triradicals. These results support the strategy of using triradical molecules for obtaining purely organic magnets with higher magnetic transition ordering temperatures since is easier to obtain ferromagnetic interactions between the radicals and these interactions, having an antiferromagnetic origin, can be stronger than typical ferromagnetic interactions between radicals.

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DAS, C. R., S. DIGAL et T. R. GOVINDARAJAN. « SPONTANEOUS SYMMETRY BREAKDOWN IN FUZZY SPHERES ». Modern Physics Letters A 24, n^o 33 (30 octobre 2009) : 2693–701. http://dx.doi.org/10.1142/s021773230902859x.

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We study and analyse the questions regarding breakdown of global symmetry on noncommutative sphere. We demonstrate this by considering a complex scalar field on a fuzzy sphere and isolating Goldstone modes. We discuss the role of nonlocal interactions present in these through geometrical considerations.

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Steigemann, Anna Marie. « Social practices in a café : community through consumption ? » Geographica Helvetica 72, n^o 1 (27 janvier 2017) : 45–54. http://dx.doi.org/10.5194/gh-72-45-2017.

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Abstract. The transformations of economic structures as well as of transportation and communication means have altered neighborhood-based interaction in the last decades. Therefore most urban studies argue that local neighborhoods have lost their function as places of sociability and solidarity. But if one looks at the more semipublic local contact sites and therein on a more superficial and fluid interactional level, interactions and ties among local residents do not seem to decrease in the same way as close and intimate ties have exceeded the neighborhood boundaries. This article thus examines the neighborhood-based interactions in one example of an important neighborhood space – a café – that demands different kinds of commitments. Practice theories thereby provide a particularly advantageous set of approaches to examine these rather spontaneous and loose micro-interactions. This is why this article ethnographically analyzes a café, as one of the important social neighborhood spaces. The article elaborates on Theodore Schatzki's (2010) and Elizabeth Shove's (2012) idea of practices as linked entities of material, competence, and meanings, coupled with Erving Goffman's conceptualization of public behavior (1959, 1963) regarding why local businesses represent locational material neighborhood settings for local micro-interactions (as social practices). Furthermore, the article addresses how these interactional practices lead to a sense of belonging and community for their carriers.

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Vidaurre, D., A. Llera, S. M. Smith et M. W. Woolrich. « Behavioural relevance of spontaneous, transient brain network interactions in fMRI ». NeuroImage 229 (avril 2021) : 117713. http://dx.doi.org/10.1016/j.neuroimage.2020.117713.

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Gorbunova, Yuliya V., et Nicholas C. Spitzer. « Dynamic interactions of cyclic AMP transients and spontaneous Ca2+ spikes ». Nature 418, n^o 6893 (juillet 2002) : 93–96. http://dx.doi.org/10.1038/nature00835.

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Carpenter, John E., et Michael Grünwald. « Heterogeneous Interactions Promote Crystallization and Spontaneous Resolution of Chiral Molecules ». Journal of the American Chemical Society 142, n^o 24 (12 mai 2020) : 10755–68. http://dx.doi.org/10.1021/jacs.0c02097.

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Bhat, Geeta, Scott Williams, Esther Tamayo, George Saade et Ram Menon. « 486 : Biomarker interactions are better predictors of spontaneous preterm birth ». American Journal of Obstetrics and Gynecology 208, n^o 1 (janvier 2013) : S210. http://dx.doi.org/10.1016/j.ajog.2012.10.652.

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Saller, H. « On the origin of gauge interactions by spontaneous symmetry breakdown ». Il Nuovo Cimento A 88, n^o 4 (août 1985) : 363–90. http://dx.doi.org/10.1007/bf02902366.

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Hindriks, Rikkert, Fetsje Bijma, Bob W. van Dijk, Cornelis J. Stam, Ysbrand Y. van der Werf, Eus J. W. van Someren, Jan C. de Munck et Aad W. van der Vaart. « Data-driven modeling of phase interactions between spontaneous MEG oscillations ». Human Brain Mapping 32, n^o 7 (10 janvier 2011) : 1161–78. http://dx.doi.org/10.1002/hbm.21099.

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Rao, Rajiv. « Manifestations of /bdg/ in Heritage Speakers of Spanish ». Heritage Language Journal 12, n^o 1 (30 avril 2015) : 48–74. http://dx.doi.org/10.46538/hlj.12.1.3.

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Inspired by the relatively sparse amount of previous work on heritage Spanish phonetics and phonology, this study examined the intervocalic productions of /bdg/ in the read and spontaneous data of eight participants between the ages of 18-21, each of whom was classified as a regular speaker, a childhood speaker, a childhood addressee or a speaker with minimal exposure to Spanish (cf. Oh & Au, 2005). An acoustic analysis of the data revealed a three-way allophonic classification of all relevant tokens: pure approximants, tense approximants and stops (cf. Martínez Celdrán, 1985, among others). Mixed-effects models were run to analyze the effects of phoneme, syllable stress, task, and word position, as well as interactions between these variables, on the realizations of /bdg/. The statistical results showed that the native-like pure approximants appeared at a significantly lower rate in /b/, in stressed syllables, at word boundaries, and in the reading task. The phoneme /b/’s interactions with the word boundary and spontaneous task variables generated a significant decrease and increase in pure approximants, respectively. When /b/ corresponded with the grapheme <v>, tense approximants were at their highest rate, but they were significantly lower in the spontaneous task. A significant interaction between these two variables informed us that /b/<v> reduced its tense approximant rate in the spontaneous task. Stops namely exhibited opposing significant main effects and interactions when compared to pure approximants. Regarding individual differences, regular speakers’ productions resembled native-like patterns, while highly variable patterns were present across the other three speaker classes, suggesting that a consistent connection with Spanish well beyond childhood is important for achieving target-like pronunciation in a heritage language as a young adult.

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Lord, Catherine, et Joyce MaGill-Evans. « Peer interactions of autistic children and adolescents ». Development and Psychopathology 7, n^o 4 (1995) : 611–26. http://dx.doi.org/10.1017/s095457940000674x.

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AbstractTwo observational studies of verbal, high-functioning children and adolescents with autism; nonautistic, behaviorally disordered youngsters of equivalent verbal skills and chronological age; and verbal age-matched normally developing students during integrated summer day camps are reported. In the first study, observations were made of spontaneous peer interaction and play over the course of 2 weeks of day camp. The eight autistic subjects were consistently more likely to not be interacting and less likely to be engaged in any purposeful activity than the 16 other children. During the 2 weeks, time interacting and purposeful activity increased overall. In the second study, the quality of spontaneous peer-directed initiations was observed during free time in similar day camps the following summer. The 11 autistic children and adolescents produced fewer initiations than did the 20 other children and were less likely to smile or coordinate several behaviors with eye contact during an initiation. Autistic subjects were consistently more likely not to receive a response to their initiation than the other groups, although there was no identifiable relationship between the quality of the initiation and the likelihood of it receiving a response.

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Kim, DoHyun, Tomer Livne, Nicholas V. Metcalf, Maurizio Corbetta et Gordon L. Shulman. « Spontaneously emerging patterns in human visual cortex and their functional connectivity are linked to the patterns evoked by visual stimuli ». Journal of Neurophysiology 124, n^o 5 (1 novembre 2020) : 1343–63. http://dx.doi.org/10.1152/jn.00630.2019.

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Spontaneous brain activity was once thought to reflect only noise, but evidence of strong spatiotemporal regularities has motivated a search for functional explanations. Here we show that the spatial pattern of spontaneous activity in human high-level and early visual cortex is related to the spatial patterns evoked by stimuli. Moreover, these patterns partly govern spontaneous spatiotemporal interactions between regions, so-called functional connectivity. These results support the hypothesis that spontaneous activity serves a representational function.

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Jiang, Huijun, et Zhonghuai Hou. « Hydrodynamic interaction induced spontaneous rotation of coupled active filaments ». Soft Matter 10, n^o 46 (2014) : 9248–53. http://dx.doi.org/10.1039/c4sm01734j.

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Carboni, C., E. Al-Abry et S. Arafin. « he Direction of Spontaneous Magnetisation of Lanthanide Ions at a Site of Cubic Symmetry ». Sultan Qaboos University Journal for Science [SQUJS] 12, n^o 1 (1 juin 2007) : 53. http://dx.doi.org/10.24200/squjs.vol12iss1pp53-66.

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The zero temperature direction of spontaneous magnetisation of lanthanide ions at a site of cubic symmetry is investigated as a function of the electrostatic and magnetic interactions. For all the values of J between J = 3 and J = 8, two-dimensional diagrams giving the orientation of spontaneous magnetisation are obtained as a function of the parameters R representing the relative strength of the magnetic to electrostatic interaction and the parameter x representing the relative strength of the fourth to the sixth order terms in the crystal field. The boundaries between regions of the parameter space with different directions of spontaneous magnetisation are investigated. It is found that at some boundaries there is a gradual rotation of the direction of spontaneous magnetisation and that at other boundaries there is a sudden change of orientation of spontaneous magnetisation at a critical value of the (R,x) parameters. Two types of behaviour are observed when there is a critical value of (R,x). There are boundaries where there is at the critical value a degenerate plane in which all the orientations can be direction of spontaneous magnetisation and some boundaries where two different principal crystallographic axes can be direction of spontaneous magnetisation at the critical value. In the latter case there is a region near the boundary where an unstable equilibrium orientation for the magnetisation can be found.

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Bonaventure M., Sala. « The Performative Aspect of Spontaneous Prayers in Cameroon : A Study in Evasive Media in Interactions ». British Journal of English Language Linguistics 10, n^o 2 (15 février 2022) : 1–15. http://dx.doi.org/10.37745/bjel.2013/vol10n2pp115.

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Studies on prayers have focussed mainly on their vertical interactive dimension between the faithful and the deity. As a result, notably with spontaneous prayers, prayers have hardly been seen as a form of horizontal communication, or as ‘evasively’ having a communicative value with the faithful, who constitute their immediate audience. This study therefore considers the horizontal effect spontaneous prayers have on the audience that listens to, or overhears, them. Our analyses show that spontaneous prayers, which turn out to be a medium of communication in its own right, can facilitate complex conversational events as they can be used for self-endearment; for control of the behaviour of the audience; as a pre-emptive measure to ward off blame; as a mild way of being insolent; to dish out criticisms or disapprove of someone’s behaviour with little retort; to give praise and advice without sounding suspicious. Given that spontaneous prayers enable speakers to better communicate sensitive information, we classify them as a medium of tact and a diplomatic weapon that helps in repairing Face Threatening Acts (FTAs) in conversation

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Dumonceaux, Julie, Sébastien Nisole, Chantal Chanel, Laurence Quivet, Ali Amara, Frano̧ise Baleux, Pascale Briand et Uriel Hazan. « Spontaneous Mutations in the env Gene of the Human Immunodeficiency Virus Type 1 NDK Isolate Are Associated with a CD4-Independent Entry Phenotype ». Journal of Virology 72, n^o 1 (1 janvier 1998) : 512–19. http://dx.doi.org/10.1128/jvi.72.1.512-519.1998.

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ABSTRACT Human immunodeficiency virus type 1 (HIV-1) entry into target cells is a multistep process initiated by envelope protein gp120 binding to cell surface CD4. The conformational changes induced by this interaction likely favor a second-step interaction between gp120 and a coreceptor such as CXCR4 or CCR5. Here, we report a spontaneous and stable CD4-independent entry phenotype for the HIV-1 NDK isolate. This mutant strain, which emerged from a population of chronically infected CD4-positive CEM cells, can replicate in CD4-negative human cell lines. The presence of CXCR4 alone renders cells susceptible to infection by the mutant NDK, and infection can be blocked by the CXCR4 natural ligand SDF-1. Furthermore, we have correlated the CD4-independent phenotype with seven mutations in the C2 and C3 regions and the V3 loop. We propose that the mutant gp120 spontaneously acquires a conformation allowing it to interact directly with CXCR4. This virus provides us with a powerful tool to study directly gp120-CXCR4 interactions.

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Johnson, M. J., et K. D. Alloway. « Cross-correlation analysis reveals laminar differences in thalamocortical interactions in the somatosensory system ». Journal of Neurophysiology 75, n^o 4 (1 avril 1996) : 1444–57. http://dx.doi.org/10.1152/jn.1996.75.4.1444.

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1. Spontaneous and stimulus-induced activity were recorded from corresponding somatotopic representations in the ventroposterolateral nucleus (VPL) of the thalamus and primary somatosensory (SI) cortex of intact, halothane-anesthetized cats. Thalamic and cortical neurons with overlapping receptive fields on the hairy skin of the forelimb were excited by a series of interleaved air jets aimed at multiple skin sites. 2. The laminar locations of 68% (240 of 355) of the neurons recorded in SI cortex were histologically reconstructed and responses of these 240 SI neurons were analyzed with respect to responses recorded from 118 thalamic neurons. Maximum responsiveness during the initial onset (1st 100 ms) of air jet stimulation was similar for neurons distributed throughout all layers of SI cortex (2-4 spikes per stimulus) and did not differ significantly from VPL responses. During the subsequent plateau phase of the stimulus, VPL neurons discharged at a mean rate of 19.0 spikes/ s and neurons in cortical layers II, IIIa, IIIb, and IV discharged at similar rates. Mean responsiveness during the plateau phase of the stimulus was significantly reduced among neurons in cortical layers V and VI and only averaged 7.1 and 3.9 spikes/s, respectively. 3. Responses recorded simultaneously from pairs of thalamic and cortical neurons were analyzed with cross-correlation analysis to determine differences in the incidence and strength of neuronal interactions as a function of cortical layer. Among 421 thalamocortical neuron pairs displaying stimulus-induced responses, 68 neuron pairs exhibited significant interactions during air jet stimulation. A laminar analysis revealed that 28% (45 of 163) of the neurons in the middle cortical layers displayed significant interactions with thalamic neurons, whereas only 14% (13 of 92) of superficial layer neurons and 6% (10 of 166) of deep layer neurons were synchronized with thalamic activity during air jet stimulation. When thalamocortical efficacy for different layers of cortex was plotted as a cumulative frequency distribution, the strongest interactions in the middle cortical layers were twice as strong as interactions involving the superficial or deep cortical layers. 4. More than 70% of stimulus-induced interactions involved thalamic discharges followed by subsequent cortical discharges and the majority of these interactions involved interspike intervals of < or = 3 ms. Nearly 75% (27 of 37) of interactions in the thalamocortical direction that involved cortical neurons in layers IIIb and IV transpired within a 3-ms interspike interval. For interactions with superficial or deep cortical layers, the proportion of thalamocortical interactions transpiring within 3 ms was only 58% (7 of 12) and 33% (2 of 6), respectively. 5. Cross-correlation analysis of spontaneous activity indicated that 124 pairs of thalamic and cortical neurons displayed synchronous activity in the absence of sensory stimulation. A laminar analysis indicated that similar proportions of cortical neurons in each layer were synchronized with thalamic activity in the absence of cutaneous stimulation. Thus 27% (44 of 163) of middle layer neurons, 30% (28 of 92) of superficial layer neurons, and 31% (51 of 166) of deep layer neurons displayed spontaneous interactions with thalamic neurons. The temporal pattern of spontaneous activity was examined with autocorrelation analysis to determine whether neuronal oscillations were essential for coordinating thalamic and cortical activity in the absence of peripheral stimulation. Only 18.5% (23 of 124) of spontaneous interactions between thalamic and cortical neurons were associated with periodic activity, which suggests that thalamocortical synchronization occurs before the constituent neurons begin to oscillate. 6. The influence of sensory stimulation on spontaneous interactions was examined in 31 pairs of thalamic and cortical neurons that exhibited interactions during prestimulus and stimulus in

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Margheritis, C., A. Marini et C. Sinistri. « Thermodynamics of ß-cyclodextrine/water Interactions ». Zeitschrift für Naturforschung A 52, n^o 4 (1 avril 1997) : 348–50. http://dx.doi.org/10.1515/zna-1997-0409.

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Abstract From a purely enthalpic standpoint, the ß-CD hydration, as studied by semiempirical calculations, appears improbable, in contrast to experiment. For the spontaneous hydration process, a compensation mechanism, connected with substrate stabilization and/or entropy increase, is suggested on the basis of simple thermodynamic considerations. The analysis is done on the basis of a single parameter Ew (> 0), which represents the energy needed to transfer a mole of water from the liquid to the ß-CD absorbed phase.The model, although simple, allows predictions largely consistent with the experimental results, while suggesting possible interpretations.

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Horan, W. P., K. H. Nuechterlein, J. K. Wynn, J. Lee, F. Castelli et M. F. Green. « Disturbances in the spontaneous attribution of social meaning in schizophrenia ». Psychological Medicine 39, n^o 4 (8 juillet 2008) : 635–43. http://dx.doi.org/10.1017/s0033291708003838.

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BackgroundSchizophrenia patients show disturbances on a range of tasks that assess mentalizing or ‘Theory of Mind’ (ToM). However, these tasks are often developmentally inappropriate, make large demands on verbal abilities and explicit problem-solving skills, and involve after-the-fact reflection as opposed to spontaneous mentalizing.MethodTo address these limitations, 55 clinically stable schizophrenia out-patients and 44 healthy controls completed a validated Animations Task designed to assess spontaneous attributions of social meaning to ambiguous abstract visual stimuli. In this paradigm, 12 animations depict two geometric shapes ‘interacting’ with each other in three conditions: (1) ToM interactions that elicit attributions of mental states to the agents, (2) Goal-Directed (GD) interactions that elicit attributions of simple actions, and (3) Random scenes in which no interaction occurs. Verbal descriptions of each animation are rated for the degree of Intentionality attributed to the agents and for accuracy.ResultsPatients had lower Intentionality ratings than controls for ToM and GD scenes but the groups did not significantly differ for Random scenes. The descriptions of the patients less closely matched the situations intended by the developers of the task. Within the schizophrenia group, performance on the Animations Task showed minimal associations with clinical symptoms.ConclusionsPatients demonstrated disturbances in the spontaneous attribution of mental states to abstract visual stimuli that normally evoke such attributions. Hence, in addition to previously established impairment on mentalizing tasks that require logical inferences about others' mental states, individuals with schizophrenia show disturbances in implicit aspects of mentalizing.

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Scalabrini, Andrea, Sjoerd J. H. Ebisch, Zirui Huang, Simone Di Plinio, Mauro Gianni Perrucci, Gian Luca Romani, Clara Mucci et Georg Northoff. « Spontaneous Brain Activity Predicts Task-Evoked Activity During Animate Versus Inanimate Touch ». Cerebral Cortex 29, n^o 11 (21 janvier 2019) : 4628–45. http://dx.doi.org/10.1093/cercor/bhy340.

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Abstract The spontaneous activity of the brain is characterized by an elaborate temporal structure with scale-free properties as indexed by the power law exponent (PLE). We test the hypothesis that spontaneous brain activity modulates task-evoked activity during interactions with animate versus inanimate stimuli. For this purpose, we developed a paradigm requiring participants to actively touch either animate (real hand) or inanimate (mannequin hand) stimuli. Behaviorally, participants perceived the animate target as closer in space, temporally more synchronous with their own self, and more personally relevant, compared with the inanimate. Neuronally, we observed a modulation of task-evoked activity by animate versus inanimate interactions in posterior insula, in medial prefrontal cortex, comprising anterior cingulate cortex, and in medial superior frontal gyrus. Among these regions, an increased functional connectivity was shown between posterior insula and perigenual anterior cingulate cortex (PACC) during animate compared with inanimate interactions and during resting state. Importantly, PLE during spontaneous brain activity in PACC correlated positively with PACC task-evoked activity during animate versus inanimate stimuli. In conclusion, we demonstrate that brain spontaneous activity in PACC can be related to the distinction between animate and inanimate stimuli and thus might be specifically tuned to align our brain with its animate environment.

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Xiang, Xuyan, et Jianguo Wu. « Dynamics of Moment Neuronal Networks with Intra- and Inter-Interactions ». Mathematical Problems in Engineering 2015 (2015) : 1–13. http://dx.doi.org/10.1155/2015/381271.

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A framework of moment neuronal networks with intra- and inter-interactions is presented. It is to show how the spontaneous activity is propagated across the homogeneous and heterogeneous network. The input-output firing relationship and the stability are first explored for a homogeneous network. For heterogeneous network without the constraint of the correlation coefficients between neurons, a more sophisticated dynamics is then explored. With random interactions, the network gets easily synchronized. However, desynchronization is produced by a lateral interaction such as Mexico hat function. It is the external intralayer input unit that offers a more sophisticated and unexpected dynamics over the predecessors. Hence, the work further opens up the possibility of carrying out a stochastic computation in neuronal networks.

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Cobos, Jacquelin E., Yassin Kissami, Issam Abdolkareem Alkutaini et Erik G. Søgaard. « Microcalorimetric Study of Carbonating Produced Water as a Promising CO2 Storage and Enhanced Oil Recovery Method ». Energies 15, n^o 8 (14 avril 2022) : 2888. http://dx.doi.org/10.3390/en15082888.

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Carbonated produced water injection (CPWI) might be considered an efficient alternative to handle the largest waste stream while enhancing the oil recovery and storing carbon dioxide (CO2) underground. This study was an attempt to get a deeper understanding of the oil recovery process through synergy between spontaneous imbibition and isothermal titration calorimetry (ITC) experiments. The results from the spontaneous imbibition experiments showed 7% to 11% additional oil recovery in comparison with plain produced water. Rock–fluid and fluid–fluid interactions, evaluated by isothermal titration calorimetry (ITC) experiments, confirmed that the CPW interactions with oil+EFB+chalk and oil+EFB systems are much more exothermic than those with plain PW in those systems. The synergy between spontaneous imbibition and ITC experiments provides an improved understanding of carbonated water injection in carbonate reservoirs.

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