Trapped magnetic field distribution above two magnetized bulk superconductors close to each other

Bulk large-grain superconductors can be used as high-field permanent magnets. Although the properties of such individual trapped field magnets are well documented, much less is known concerning their behaviour when two are brought together. In this work, the interaction between two cylindrical bulk YBa2Cu3O7 (YBCO) superconductors is described. Two sets of experiments were carried out. The first involved the simultaneous magnetization of two bulk superconductors placed a short distance apart. Here, the applied magnetic field was aligned parallel to the c-axis of one bulk, while the other was oriented with its c-axis offset . For a centre-to-centre distance equal to twice the sample height, the presence of the second sample is found not to alter the current distribution inside the first. Consequently, the contribution of both samples simply sums, thus increasing the magnetic flux density between them. In the second set of experiments, the translational approach of the superconductors with parallel c-axes was investigated. The following configurations were considered: (i) face to face approach (with anti-parallel trapped field orientation) and (ii) sideways approach (with parallel trapped field orientation). An irreversible decrease of the trapped field was measured on separation . Repeated approach cycles showed that the irreversible loss of trapped field is largest for the first approach.Henry Royce Institute (Equipment grant ref. EP/P024947/1) We thank the University of Liege for equipment and travel grants. Michel Houbart is recipient of a FRS-FNRS Research Fellow gran

Adult intradural lipoma with tethered spinal cord syndrome

A 48-year-old woman presented to our imaging department with lumbar sciatica. The patient had a medical history of low back pain and spina bifida. A transverse section lumbar spine CT-scan, obtained with soft-tissue window setting (Fig. A, arrow) showed, a fat-density (45-HU), oblong, posterior intradural supracentimetric lesion, at level of L5-S1. The use of bone window setting revealed a spina bifida at L4-L5-S1 (Fig. B, arrow). Lumbar spine MRI performed shortly afterwards confirmed the presence of a posterior intradural supracentimetric lesion, at level of L5-S1, hyperintense on T1 (Fig. C, arrow) and T2, and hypointetense on T2 Stir weighted imaging (Fig. D, arrow), and showed that the filum terminale was attached to the aforementioned lesion. It also demonstrated that the conus medullaris was in an abdormally low position, set at the spinal level of L3-L4. Intradural spinal lipoma with tethered spinal cord was diagnosed. The patient will benefit from physiotherapy and a surgical option could be envisaged according to the clinical evolution

Developmental Fluoxetine Exposure Normalizes the Long-Term Effects of Maternal Stress on Post-Operative Pain in Sprague-Dawley Rat Offspring

Early life events can significantly alter the development of the nociceptive circuit. In fact, clinical work has shown that maternal adversity, in the form of depression, and concomitant selective serotonin reuptake inhibitor (SSRI) treatment influence nociception in infants. The combined effects of maternal adversity and SSRI exposure on offspring nociception may be due to their effects on the developing hypothalamic-pituitary-adrenal (HPA) system. Therefore, the present study investigated long-term effects of maternal adversity and/or SSRI medication use on nociception of adult Sprague-Dawley rat offspring, taking into account involvement of the HPA system. Dams were subject to stress during gestation and were treated with fluoxetine (2×/5 mg/kg/day) prior to parturition and throughout lactation. Four groups of adult male offspring were used: 1. Control+Vehicle, 2. Control+Fluoxetine, 3. Prenatal Stress+Vehicle, 4. Prenatal Stress+Fluoxetine. Results show that post-operative pain, measured as hypersensitivity to mechanical stimuli after hind paw incision, was decreased in adult offspring subject to prenatal stress alone and increased in offspring developmentally exposed to fluoxetine alone. Moreover, post-operative pain was normalized in prenatally stressed offspring exposed to fluoxetine. This was paralleled by a decrease in corticosteroid binding globulin (CBG) levels in prenatally stressed offspring and a normalization of serum CBG levels in prenatally stressed offspring developmentally exposed to fluoxetine. Thus, developmental fluoxetine exposure normalizes the long-term effects of maternal adversity on post-operative pain in offspring and these effects may be due, in part, to the involvement of the HPA system

Survival, growth and feeding in early life stages of European sea bass (<i>Dicentrarchus labrax</i>) intensively cultured under different stocking densities

Two experiments were conducted in triplicate in order to study the effect of stocking densities on survival (highlighting sibling cannibalism), growth and feeding of intensively cultured sea bass larvae (50, 100, 150 and 200 fish l(-1)) and post-larvae (5, 10, 15 and 20 fish l(-1)). Experimental populations were reared under controlled conditions in 50-l cylindroconical tanks. Dead fish were counted daily and classified into cannibalised and non-cannibalised. Total length and weight were measured weekly. Results indicate that stocking density did not affect survival and growth of larvae. No cannibalistic phenomena were observed at this stage. On the other hand, survival of post-larvae was higher at 5 and 10 fish l(-1) than at 15 and 20 fish l(-1), while growth performance fluctuated between the lowest value recorded in the group of 10 fish l(-1) and the highest value in that of 5 fish l(-1). Feed intake in post-larvae was independent of stocking density. Cannibalism was the main cause of death in post-larvae. Two types of cannibalism were detected: type I, attack from tail (observed at the beginning of this stage) and type II, attack from head (observed at the end of the stage)