102 research outputs found

    In vivo two-photon imaging of the embryonic cortex reveals spontaneous ketamine-sensitive calcium activity

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    Prior to sensory experience spontaneous activity appears to play a fundamental role in the correct formation of prominent functional features of different cortical regions. The use of anaesthesia during pregnancy such as ketamine is largely considered to negatively affect neuronal development by interfering with synaptic transmission. Interestingly, the characteristics of spontaneous activity as well as the acute functional effects of maternal anaesthesia remain largely untested in the embryonic cortex in vivo. In the present work, we performed in vivo imaging of spontaneous calcium activity and cell motility in the marginal zone of the cortex of E14-15 embryos connected to the mother. We made use of a preparation where the blood circulation from the mother through the umbilical cord is preserved and fluctuations in intracellular calcium in the embryonic frontal cortex are acquired using two-photon imaging. We found that spontaneous transients were either sporadic or correlated in clusters of neuronal ensembles at this age. These events were not sensitive to maternal isoflurane anaesthesia but were strongly inhibited by acute in situ or maternal application of low concentration of the anaesthetic ketamine (a non-competitive antagonist of NMDA receptors). Moreover, simultaneous imaging of cell motility revealed a correlated strong sensitivity to ketamine. These results show that anaesthetic compounds can differ significantly in their impact on spontaneous early cortical activity as well as motility of cells in the marginal zone. The effects found in this study may be relevant in the etiology of heightened vulnerability to cerebral dysfunction associated with the use of ketamine during pregnancy.Peer reviewe

    Student Attitudes Towards Distance Learning at a Large Urban Public College

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    Student attitudes towards distance learning can affect both the acquisition of knowledge and the motivation to learn. This study explores student attitudes towards the following four topics: (1) technological and environmental impediments towards distance learning, (2) asynchronous vs. synchronous course preferences, (3) online vs. in-person course preferences, and (4) attitudes towards taking online courses in the future. The findings of the study are based on two anonymous online surveys conducted in the spring and fall of 2020 among students at a large urban public college located in the Northeast U.S.  The study reveals that a significant number of students have unreliable Internet and live in homes not conducive for online learning.  By a narrow margin, students prefer an asynchronous to a synchronous approach to online learning.  Along several dimensions covering different facets of the classroom experience, students prefer in-person courses to online courses.  The disparities favoring in-person classes are most noticeable with respect to the ability to concentrate in class sessions, feeling motivated to learn, and developing friendship ties with classmates.  Distinctive profiles exist among students who opt for these different teaching modalities.  Those students who are more positively disposed towards in-person classes tend to be younger,  freshmen or sophomores, those experiencing higher stress levels, and those whose physical arrangements at home are not conducive for learning.  Importantly, though, a majority of students say they were inclined towards taking more online course in the future. 

    Psychological profiles derived by cluster analysis of Minnesota Multiphasic Personality Inventory and long term clinical outcome after coronary artery by pass grafting

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    Background: To evaluate the psychological characteristics of coronary heart disease (CHD) patients after coronary artery bypass grafting (CABG) by cluster analysis of Minnesota Multiphasic Personality Inventory (MMPI-2) questionnaires and to assess the impact of the profiles obtained on long-term outcome. Methods: 229 CHD patients admitted to cardiac rehabilitation filled in self-administered MMPI-2 questionnaires early after CABG. We assessed the relation between MMPI- 2 profiles derived by cluster analysis, clinical characteristics and outcome at 3-year follow-up. Results: Among the 215 patients (76% men, median age 66 years) with valid criteria in control scales, we identified 3 clusters (G) with homogenous psychological characteristics: G1 patients (N=75) presented somatoform complaints but overall minimal psychological distress. G2 patients (N=72) presented type D personality traits. G3 subjects (N=68) showed a trend to cynicism, mild increases in anger, social introversion and hostility. Clusters overlapped for clinical characteristics such as smoking (G1 21%, G2 24%, G3 24%, p ns), previous myocardial infarction (G1 43%, G2 47%, G3 49% p ns), LV ejection fraction (G1 60 [51 – 60]; G2 58 [49- 60]; G3 60 [55-60], p ns), 3-vessel-disease prevalence (G1 69%, G2 65%, G3 71%, p ns). Three-year event rates were comparable (G1 15%; G2 18%; G3 15%) and Kaplan- Meier curves overlapped among clusters (p ns). Conclusions: After CABG, the interpretation of MMPI- 2 by cluster analysis is useful for the psychological and personological diagnosis to direct psychological assistance. Conversely, results from cluster analysis of MMPI-2 do not seem helpful to the clinician to predict long term outcome

    Social acceptability of treatments for adolescent idiopathic scoliosis: a cross-sectional study

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    BACKGROUND: There are no data on social acceptability of scoliosis. Aim. To elicit evidence-based opinions on therapeutic strategies for adolescent idiopathic scoliosis in a sample of families with not affected children, so to understand the social perception of this issue. METHODS: Design. Cross-sectional study. Setting. Secondary schools in 4 northern Italian regions. Participants. Parents of children in the age group at risk of and not affected by scoliosis (Pre-test group = 100, Study group = 3,162). Interventions. Questionnaire: five specific and evidence-based questions regarding scoliosis treatment options and a socio-demographic section. Methodology. "Role-playing" in which it was required to normal people to answer what they would have chosen if they had been in the situation proposed. Main outcome measures. Perception of acceptability of treatments for adolescent idiopathic scoliosis in the general population (social acceptability) RESULTS: The families support the use of screening (94.8%) at school, immediate bracing (76.4%) for scoliosis with a 60% risk of progression, but also therapeutic exercises (86.9%) in cases with a 25% risk of progression. CONCLUSION: There is a growing tendency to consider not only the efficacy, effectiveness and efficiency of treatments, but also their acceptability. This patient-centred aspect is especially more important in areas (like adolescent idiopathic scoliosis) in which there is some evidence on the efficacy of treatments, but not strong and definitive (RCTs). Adolescent idiopathic scoliosis treatments should thus be carefully considered also in the light of their social acceptability

    Forces exerted during exercises by patients with adolescent idiopathic scoliosis wearing fiberglass braces

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    OBJECTIVE: To quantify and compare the forces exerted by scoliosis patients in fiberglass braces during exercises usually prescribed in departments where casts are made. The exercises are intended to increase corrective forces, activate muscles, stimulate ventilation and help the patient psychologically. SETTING: Outpatient care. PATIENTS: 17 consecutive adolescent patients wearing fiberglass brace for idiopathic scoliosis. INTERVENTIONS: Exercises (kyphotization, rotation, "escape from the pad") in different positions (sitting, supine, on all fours). MAIN OUTCOME MEASURE: Pressure detected by the F-Socket System between the rib hump and the pad of the brace. RESULTS: In static and dynamic conditions, the position adopted did not alter the total pressure exerted by the brace, although the part of the sensor stimulated did vary. Kyphotization and rotation exercises produced a significant increase of pressure (+ 58.9% and +29.8%, respectively); however, the "escape from the pad" exercise, despite its name, did not produce any significant variation of pressure. CONCLUSION: Exercises in the brace allow adjunctive forces to be applied on soft tissues and through them, presumably on the spine. Different exercises can be chosen to obtain different actions. Physical exercises and sporting activities are useful in mechanical terms, although other important actions should not be overlooked

    The Role of the Interplay between Stimulus Type and Timing in Explaining BCI-Illiteracy for Visual P300-Based Brain-Computer Interfaces

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    Visual P300-based Brain-Computer Interface (BCI) spellers enable communication or interaction with the environment by flashing elements in a matrix and exploiting consequent changes in end-user's brain activity. Despite research efforts, performance variability and BCI-illiteracy still are critical issues for real world applications. Moreover, there is a quite unaddressed kind of BCI-illiteracy, which becomes apparent when the same end-user operates BCI-spellers intended for different applications: our aim is to understand why some well performers can become BCI-illiterate depending on speller type. We manipulated stimulus type (factor STIM: either characters or icons), color (factor COLOR: white, green) and timing (factor SPEED: fast, slow). Each BCI session consisted of training (without feedback) and performance phase (with feedback), both in copy-spelling. For fast flashing spellers, we observed a performance worsening for white icon-speller. Our findings are consistent with existing results reported on end-users using identical whiteĂ—fast spellers, indicating independence of worsening trend from users' group. The use of slow stimulation timing shed a new light on the perceptual and cognitive phenomena related to the use of a BCI-speller during both the training and the performance phase. We found a significant STIM main effect for the N1 component on Pz and PO7 during the training phase and on PO8 during the performance phase, whereas in both phases neither the STIMĂ—COLOR interaction nor the COLOR main effect was statistically significant. After collapsing data for factor COLOR, it emerged a statistically significant modulation of N1 amplitude depending to the phase of BCI session: N1 was more negative for icons than for characters both on Pz and PO7 (training), whereas the opposite modulation was observed for PO8 (performance). Results indicate that both feedback and expertise with respect to the stimulus type can modulate the N1 component and that icons require more perceptual analysis. Therefore, fast flashing is likely to be more detrimental for end-users' performance in case of icon-spellers. In conclusion, the interplay between stimulus type and timing seems relevant for a satisfactory and efficient end-user's BCI-experience

    Origin and physiopathology of cortical malformation : periventricular nodular heterotopia due to mutations in FLNA gene.

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    Les hétérotopies nodulaires périventriculaires (HNP) correspondent aux malformations cérébrales les plus fréquemment découvertes à l'âge adulte. Survenant au cours de la migration, elles consistent en l'apparition de nodules de neurones ectopiques positionnés le long de la paroi des ventricules latéraux. Sur le plan clinique, les HNP associent une épilepsie et/ou un retard mental. Les mutations dans le gène FLNA (Xq28) représentent la cause majeure des HNP. Une forme récessive rare d'HNP liée à des mutations du gène ARFGEF2 (20q13) et des réarrangements chromosomiques identifiés chez des patients présentant une HNP ont également été rapportés. Alors que le lien entre les HNP associées à des mutations du gène FLNA et leurs manifestations cliniques a été clairement établi, les mécanismes physiopathologiques sous-jacents restent à ce jour inconnus. Deux lignées de souris knockout pour FlnA ont été développées mais aucune de ces deux lignées n'a développé d'HNP. Nous avons donc choisi de créer un nouveau modèle, chez le rat, par inactivation in utero du gène FlnA en utilisant la technique de l'ARN interférence (RNAi). Par cette approche, nous avons reproduit avec succès un phénotype d'HNP chez le rat comparable à celui observé chez les patients. Sur ce modèle, nous avons montré que l'HNP est associée à une désorganisation de la glie radiaire et à une incapacité des progéniteurs neuronaux de progresser dans le cycle cellulaire. En accord avec ces observations, une désorganisation de la glie radiaire a été également observée dans des cerveaux post-mortem de deux patientes présentant une HNP associée à une mutation de FLNA.Periventricular nodular heterotopia (PNH) is a brain malformation caused by defective neuronal migration resulting in ectopic neuronal nodules lining the lateral ventricles. Most patients have epilepsy, with normal to borderline cognitive function. Mutations in FLNA are the main cause of PH. A rare recessive form caused by mutations in the ARFGEF2 gene (20q13) and chromosomal rearrangements identified in patients with PNH have been reported. The link between FLNA-trelated PH and clinical manifestattions has been wee established but the underlying pathological mechanism remains unknown. Though two FlnA knockout mice strains have been developed, progress has been hindered by the fact that none of them showed the presence of ectopic nodules. Therefore, to recapitulate the loss of FlnA function in the developing rat brain, we used an in utero RNA interference (RNAi)-mediated knockdown approach and successfully reproduced a PNH phenotype in rats comparable to that observed in patients. Using this FlnA knockdown rodent model, we demonstrated that PNH is associated with a disruption in radial glial scaffold integrity in the ventricular zone and also an inability for neuroprogenitor cells to progress adequately through the cell cycle.Consistent with the observations made in rodents, we found similar alterations of radial glia in postmortem brains of two PNH patients harboring distinct FLNA mutations. These data highlights the complexity of the pathogenesis of PNH, the likelihood that several mechanisms are coalescing to lead to disrupted neuronal migration

    2. Les scènes de la chanson à Paris (1950-1985)

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    Carabalona Jean. 2. Les scènes de la chanson à Paris (1950-1985). In: Vibrations, N. 5, 1988. La scène, sous la direction de Louis-Jean Calvet. pp. 29-39

    Le flux libre instinctif, de la découverte à l'intégration de la pratique : étude qualitative portant sur la démarche, les motivations et le vécu des femmes pratiquant le flux libre instinctif

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    Objectives: The objective was to understand the approach of women practicing free bleeding, that means their motivations and the process(es) that led them to this practice; as well as their experience, their feelings, positive or negative, in the establishment and continuation of this practice. Methods: This was a qualitative study with an interpretative phenomenological analysis (IPA). Recruitment was done via a call for participation on social networks. Data collection was carried out through semi-structured interviews. Results: Nine semi-structured interviews were conducted and 7 analyzed to reach data saturation. The approaches of women practicing free bleeding were very individual and their own path to each, sometimes requiring a lapse of time between discovery and the transition to practice. A certain instinctive basis was mentioned in the testimonies and the women evolved their practice by adjusting it to a mode of operation that suited them. The women reported a more global development in which they had changed their relationship to their body and to menstruation and which had resulted in a gain in self-confidence. Conclusion: The free bleeding is a practice that can provide a concrete solution to a problem around the menstruation but which also goes in the direction of personal fulfillment and empowerment of women.Objectifs : L’objectif était de comprendre la démarche des femmes pratiquant le flux libre instinctif, c’est-à-dire leurs motivations et le(s) processus qui les a(ont) menées à cette pratique ; ainsi que leur vécu, leurs ressentis, positif ou négatif, dans la mise en place et la poursuite de cette pratique. Méthodes : Il s’agissait d’une étude qualitative avec une analyse phénoménologique interprétative (IPA). Le recrutement a été fait via un appel à participation sur les réseaux sociaux. Le recueil des données a été réalisé lors d’entretiens semi-directifs. Résultats : Neuf entretiens semi-directifs ont été réalisés et 7 analysés pour arriver à saturation des données. Les démarches des femmes pratiquant le flux libre instinctif étaient très individuelles et leur cheminement propre à chacune, nécessitant parfois un laps de temps entre la découverte et le passage à la pratique. Une certaine base instinctive a été évoquée dans les témoignages et les femmes ont fait évoluer leur pratique en l’ajustant vers un mode de fonctionnement qui leur convenait. Les femmes rapportaient une évolution plus globale dans laquelle elles avaient changé leur rapport à leur corps et aux règles et qui avait aboutie à une prise de confiance en elle. Conclusion : Le flux libre instinctif est une pratique qui peut apporter une solution concrète à une problématique autour des règles mais qui va aussi dans le sens d’un épanouissement personnel et d’un empowerment de la femme
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