132 research outputs found

    Magnetic levitation on a type-I superconductor as a practical demonstration experiment for students

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    We describe and discuss an experimental set-up which allows undergraduate and graduate students to view and study magnetic levitation on a type-I superconductor. The demonstration can be repeated many times using one readily available 25 liter liquid helium dewar. We study the equilibrium position of a magnet that levitates over a lead bowl immersed in a liquid hand-held helium cryostat. We combine the measurement of the position of the magnet with simple analytical calculations. This provides a vivid visualization of magnetic levitation from the balance between pure flux expulsion and gravitation. The experiment contrasts and illustrates the case of magnetic levitation with high temperature type-II superconductors using liquid nitrogen, where levitation results from partial flux expulsion and vortex physics

    Differences between individuals with schizophrenia or obsessive-compulsive disorder and healthy controls in social cognition and mindfulness skills: A controlled study

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    The study of social cognition (SC) has emerged as a key domain of mental health, supporting the notion that poorer performance in SC tasks is linked to psychopathology, although most studies have primarily addressed only schizophrenia (SZ). Some recent studies have also shown deficits of SC in obsessive-compulsive disorder (OCD) patients; however, little is known about how individuals with OCD may differ on SC performance from individuals with SZ. Moreover, initial research in this field suggests that mindfulness skills may be related to SC abilities such as theory of mind (ToM), emotion processing and empathy. Given the potential benefits of mindfulness for treating OCD and SZ, further efforts are needed to understand the association between mindfulness and SC in these populations. The main objective of this study was to compare samples of patients with SZ and OCD to healthy controls (HCs) on several social cognition (SC) domains and mindfulness measures. In total, 30 outpatients diagnosed with SZ, 31 outpatients diagnosed with OCD and 30 healthy controls were assessed in emotion recognition (the Eyes Test), ToM (the Hinting Task), attributional style (the Ambiguous Intentions and Hostility Questionnaire), empathy (the Interpersonal Reactivity Index) and dispositional mindfulness (the MAAS and the FFMQ). Both clinical groups showed poorer performance in emotion recognition and ToM than the HCs. The OCD and SZ patients did not significantly differ in impairment in SC, but the OCD group had higher scores in attributional style (intentionality and anger bias). With regard to mindfulness, the results found lower levels of acting with awareness for the HCs than for either clinical group and higher non-reactivity to inner experience for the HCs than for the individuals with OCD; the results also yielded significant correlations between SC and mindfulness. In conclusion, these findings revealed that SC abilities were impaired in the SZ and OCD groups compared to the HC group, suggesting a similar disrupted pattern in both clinical groups. Aspects of dispositional mindfulness were differentially associated with SC, which may suggest their potential role in novel transdiagnostic interventions

    FAME : A new beamline for X-ray absorption investigations of very-diluted systems of environmental, material and biological interests

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    International audienceFAME is the French Absorption spectroscopy beamline in Material and Environmental sciences at the ESRF (France), operational since September 2002. Technically speaking, the source is a 0.85 T bending magnet and the main optical element is a two-crystals monochromator using either Si(111) or Si(220) monocrystals so that the available energy ranges from 4 to 40 keV. The first crystal is liquid nitrogen cooled in order to avoid a thermal bump and thus preserve the energy resolution. The second crystal is dynamically bent during the energy scan in order to focus the beam in the horizontal plane. Two bendable mirrors are located before and after the monochromator, for beam-collimation (to optimize the energy resolution) and vertical focalization, respectively. During scans, the beam on the sample is kept constant in position and size (around 150 × 200 μm2, V × H). The high flux on the sample combined with the sensitivity of our 30-elements fluorescence detector allow to decrease the detection limit down to 10 ppm or around less than a monolayer. Moreover, quick-EXAFS acquisition is operational: the acquisition time may be reduced down to 30s

    Abnormal Distribution and Function of Circulating Monocytes and Enhanced Bacterial Translocation in Major Depressive Disorder

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    Introduction: Major depressive disorder (MDD) patients experience a systemic inflammatory stage. Monocytes play an important role in innate inflammatory responses and may be modulated by bacterial translocation. Our aim was to investigate the subset distribution and function of circulating monocytes, levels of proinflammatory cytokines, gut barrier damage, and bacterial translocation in MDD patients. Methods: Twenty-two MDD patients without concomitant diseases and 14 sex- and age-matched healthy controls were studied. The levels of circulating CD14++CD16- (classical), CD14++CD16++ (intermediate) and CD14- CD16++ (nonclassical) monocytes and the intracytoplasmic tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 expression in the presence or absence of lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. The serum TNF-α, IL-1β, IL-6, and IL-10 levels were measured by Luminex. LPS-binding protein (LBP), intestinal fatty acidbinding protein (I-FABP), and zonulin were measured by enzyme-linked immunosorbent assay (ELISA). Results: MDD patients had a significant increase in the frequency of intermediate monocytes and a significant decrease in the frequency of classical monocytes compared to those in the healthy controls. MDD patients had a significantly increased percentage of classical monocytes that expressed IL-1β, intermediate monocytes that expressed IL-1β and IL6 and nonclassical monocytes that expressed IL-1β, and decreased levels of nonclassical monocytes that expressed IL6 compared to those in the healthy controls. MDD patients had significantly increased levels of circulating TNF-α, IL-1β, LBP, and I-FABP compared to those in the healthy controls. MDD patients with high LBP levels had a significant reduction in the number of circulating monocytes compared to that in the normal-LBP MDD patients, which can be mainly ascribed to a decrease in the number of intermediate and nonclassical monocytes. Conclusions: We have demonstrated that compared to the healthy controls, MDD patients show a marked alteration in circulating monocytes, with an expansion of the intermediate subset with increased frequency of IL-1β and IL-6 producing cells. These patients also exhibited a systemic proinflammatory state, which was characterized by the enhanced serum TNF-α and IL-1β levels compared to those in the healthy controls. Furthermore, MDD patients showed increased LBP and I-FABP levels compared to those in healthy controls, indicating increased bacterial translocation and gut barrier damage

    Group and sex differences in social cognition in bipolar disorder, schizophrenia/schizoaffective disorder and healthy people

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    Background: Impairment of social cognition is documented in bipolar disorder (BD) and schizophrenia/schizoaffective disorder (SCH). In healthy individuals, women perform better than men in some of its sub-domains. However, in BD and SCH the results are mixed. Our aim was to compare emotion recognition, affective Theory of Mind (ToM) and first- and second-order cognitive ToM in BD, SCH and healthy subjects, and to investigate sex-related differences. Methods: 120 patients (BD = 60, SCH = 60) and 40 healthy subjects were recruited. Emotion recognition was assessed by the Pictures of Facial Affect (POFA) test, affective ToM by the Reading the Mind in the Eyes Test (RMET) and cognitive ToM by several false-belief stories. Group and sex differences were analyzed using parametric (POFA, RMET) and non-parametric (false-belief stories) tests. The impact of age, intelligence quotient (IQ) and clinical variables on patient performance was examined using a series of linear/logistic regressions. Results: Both groups of patients performed worse than healthy subjects on POFA, RMET and second-order false-belief (p < 0.001), but no differences were found between them. Instead, their deficits were related to older age and/or lower IQ (p < 0.01). Subthreshold depression was associated with a 6-fold increased risk of first-order false-belief failure (p < 0.001). Sex differences were only found in healthy subjects, with women outperforming men on POFA and RMET (p ≤ 0.012), but not on first/second-order false-belief. Limitations: The cross-sectional design does not allow for causal inferences. Conclusion: BD and SCH patients had deficits in emotion recognition, affective ToM, and second-order cognitive ToM, but their performance was comparable to each other, highlighting that the differences between them may be subtler than previously thought. First-order cognitive ToM remained intact, but subthreshold depression altered their normal functioning. Our results suggest that the advantage of healthy women in the emotional and affective aspects of social cognition would not be maintained in BD and SCH

    Women with psychotic episodes during pregnancy show increased markers of placental damage with Tenney-Parker changes

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    y. Psychosis is a hazardous and functionally disruptive psychiatric condition which may affect women in pregnancy, entailing negative consequences for maternofetal well-being. The precise pathophysiological basis and consequences of a psychotic episode in pregnancy remain to be further elucidated. The placenta is a pivotal tissue with many functions in the gestational period, critically influencing the fate and development of pregnancy. Although detrimental alterations have been observed in women undergoing severe psychiatric disorders in pregnancy, there are little studies evaluating the consequences of suffering from a psychotic episode in the placental tissue In this work, we have evaluated the histopathological consequences of a first episode of psychosis in pregnancy (FE-PW; N=22) and compare them with healthy pregnant women (HC-PW; N=20) by using histological, immunohistochemical and gene expression techniques. Our results define that the placental tissue of FE-PW display an increase in the number of placental villi, bridges, syncytial knots and syncytial knots/villi. Besides, we have also observed an enhanced gene and protein expression in FE-PW of the hypoxic marker HIF-1α, together with the apoptotic markers BAX and Bcl-2. To our knowledge, this is the first study demonstrating significant histopathological changes in the placenta of women suffering a new-onset psychotic episode in pregnancy. Further studies should be aimed at deepening the knowledge about the pernicious effects of psychosis in the maternofetal tissues, as well as the potential implications of these alterations

    Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study

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    <p>Abstract</p> <p>Background</p> <p>Cognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients.</p> <p>Methods</p> <p>12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated.</p> <p>Results</p> <p>(1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex.</p> <p>Conclusions</p> <p>Individuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.</p

    What to consider when pseudohypoparathyroidism is ruled out: IPPSD and differential diagnosis

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    Background: Pseudohypoparathyroidism (PHP) is a rare disease whose phenotypic features are rather difficult to identify in some cases. Thus, although these patients may present with the Albright''s hereditary osteodystrophy (AHO) phenotype, which is characterized by small stature, obesity with a rounded face, subcutaneous ossifications, mental retardation and brachydactyly, its manifestations are somewhat variable. Indeed, some of them present with a complete phenotype, whereas others show only subtle manifestations. In addition, the features of the AHO phenotype are not specific to it and a similar phenotype is also commonly observed in other syndromes. Brachydactyly type E (BDE) is the most specific and objective feature of the AHO phenotype, and several genes have been associated with syndromic BDE in the past few years. Moreover, these syndromes have a skeletal and endocrinological phenotype that overlaps with AHO/PHP. In light of the above, we have developed an algorithm to aid in genetic testing of patients with clinical features of AHO but with no causative molecular defect at the GNAS locus. Starting with the feature of brachydactyly, this algorithm allows the differential diagnosis to be broadened and, with the addition of other clinical features, can guide genetic testing. Methods: We reviewed our series of patients (n = 23) with a clinical diagnosis of AHO and with brachydactyly type E or similar pattern, who were negative for GNAS anomalies, and classify them according to the diagnosis algorithm to finally propose and analyse the most probable gene(s) in each case. Results: A review of the clinical data for our series of patients, and subsequent analysis of the candidate gene(s), allowed detection of the underlying molecular defect in 12 out of 23 patients: five patients harboured a mutation in PRKAR1A, one in PDE4D, four in TRPS1 and two in PTHLH. Conclusions: This study confirmed that the screening of other genes implicated in syndromes with BDE and AHO or a similar phenotype is very helpful for establishing a correct genetic diagnosis for those patients who have been misdiagnosed with "AHO-like phenotype" with an unknown genetic cause, and also for better describing the characteristic and differential features of these less common syndromes
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