Neural substrates of emotion dysregulation in adolescent suicide attempters remain unexamined.
We used functional magnetic resonance imaging to measure neural activity to neutral, mild or intense ...(i.e., 0%, 50% or 100% intensity) emotion face morphs in two separate emotion-processing runs (angry and happy) in three adolescent groups: (1) history of suicide attempt and depression (ATT, n=14) ; (2) history of depression alone (NAT, n=15) ; and (3) healthy controls (HC, n=15). Post-hoc analyses were conducted on interactions from 3 group x 3 condition (intensities) whole-brain analyses (p<0.05, corrected) for each emotion run.
To 50% intensity angry faces, ATT showed significantly greater activity than NAT in anterior cingulate gyral–dorsolateral prefrontal cortical attentional control circuitry, primary sensory and temporal cortices; and significantly greater activity than HC in the primary sensory cortex, while NAT had significantly lower activity than HC in the anterior cingulate gyrus and ventromedial prefrontal cortex. To neutral faces during the angry emotion processing run, ATT had significantly lower activity than NAT in the fusiform gyrus. ATT also showed significantly lower activity than HC to 100% intensity happy faces in the primary sensory cortex, and to neutral faces in the happy run in the anterior cingulate and left medial frontal gyri (all p<0.006,corrected). Psychophysiological interaction analyses revealed significantly reduced anterior cingulate gyral–insula functional connectivity to 50% intensity angry faces in ATT v. NAT or HC.
Elevated activity in attention control circuitry, and reduced anterior cingulate gyral–insula functional connectivity, to 50% intensity angry faces in ATT than other groups suggest that ATT may show inefficient recruitment of attentional control neural circuitry when regulating attention to mild intensity angry faces, which may represent a potential biological marker for suicide risk.
In the framework of the NEWGAIN project, which aims to build a second injector with a mass to charge-state ratio A/q=7 for the SPIRAL2 linear accelerator at GANIL, CEA is developing in collaboration ...with LPSC and GANIL a new superconducting 28 GHz ECR Ion Source Magnet named ASTERICS. The magnetic design is based on an advanced concept of the VENUS ECR ion source operating at Berkeley and the FRIB source under commisionning at MSU. The ion source superconducting magnet consists of a sextupole inside three solenoids to confine the plasma and a shell-based support structure to apply a preload to the sextupole coils. The confinement coils will be made in Nb-Ti and will be operated at 4.2 K. The cryogenic environment will be ensured by liquid helium thermosiphon closed loop thanks to six in-situ cryocoolers. Specific HTS current leads are being designed to power the magnet. A cold integrated He buffer will also allow He almost-lossless quenches. The preliminary design choices of the ASTERICS superconducting magnet are presented here from the magnetic, mechanical and protection design to the cryogenic definition emphasizing the global approach used to obtain the final magnet configuration.
The High Luminosity LHC (HL-LHC) project aims at accumulating 3000 fb -1 in the years 2023-2035, i.e., ten times more w.r.t. the nominal LHC performance expected for 2010-2021. One key element to ...reach this challenging performance is a new insertion region to reduce the beam size in the interaction point by approximately a factor two. This requires larger aperture magnets in the region spanning from the interaction point to the matching section quadrupoles. This aperture has been fixed to 150 mm for the inner triplet quadrupoles in 2012. In this paper, we give a first baseline of the interaction region. We discuss the main motivations that lead us to choose the technology, the combination of fields/gradients and lengths, the apertures, the quantity of superconductor, and the operational margin. Key elements are also the constraints given by the energy deposition in terms of heat load and radiation damage; we present the main features related to shielding and heat removal.
A future circular collider (FCC) with a center-of-mass energy of 100 TeV and a circumference of around 100 km, or an energy upgrade of the LHC (HE-LHC) to 27 TeV require bending magnets providing 16 ...T in a 50-mm aperture. Several development programs for these magnets, based on Nb 3 Sn technology, are being pursued in Europe and in the U.S. In these programs, cos-theta, block-type, common-coil, and canted-cos-theta magnets are explored; first model magnets are under manufacture; limits on conductor stress levels are studied; and a conductor with enhanced characteristics is developed. This paper summarizes and discusses the status, plans, and preliminary results of these programs.
For the HL-LHC project, a 90 mm NbTi cos(2θ) double aperture quadrupole magnet with an operating gradient of 120 T/m at 1.9 K has been designed as an option to replace the 70 mm aperture LHC ...quadrupole MQY. CEA in collaboration with CERN designed and manufactured a single aperture short model magnet with a magnetic length of 1.215 m at 1.9 K called MQYYM. The MQYYM cold test occurred at CEA at 4.2 K in a vertical cryogenic station. During the power test, the operating gradient at 1.9 K has been reached after two training quenches. All along the test, magnetic and mechanical measurements were done using respectively a rotating probe and strain gauges. This paper describes the performance of the MQYYM at 4.2 K and gives an analysis of the data acquired during the test, including training behavior, quench detection, protection and field quality measurements.
In the framework of the HL-LHC project, a NbTi double aperture quadrupole magnet MQYY is being developed as an option to replace the LHC magnet MQY. This 90 mm double aperture cos-2θ quadrupole has ...an operating gradient of 120 T/m at 1.9 K. To demonstrate the validity of the design, a single aperture short model of 1.2 m called MQYYM has been developed. Designed by CEA and manufactured in collaboration with CERN, the MQYYM magnet is being prepared for cold test at CEA in a dedicated cryogenic station with LHe bath at 1 bar 4.2 K and 23 mbar 1.9 K. First, this paper will summarize the initial and as-built magnet designs based on the assembly at CERN. Second, updated mechanical measurements of collaring and axial pre-loading will be presented. Finally warm magnetic measurements performed at CERN during the assembly and at CEA during test preparation will be detailed.
The luminosity upgrade of the LHC requires replacing the magnets around the ATLAS and CMS experiments with larger aperture dipoles, quadrupoles and correctors. The goal is to have a magnetic lattice ...that can allow to halve the beam size in the collision points with respect to present baseline. Within the framework of HiLumi LHC, CEA-Saclay studied the replacement of the 70-mm double aperture quadrupole Q4, with a 90-mm magnet based on Nb-Ti technology. The main challenges are due to the distance between the beams of 194 mm, giving a non-negligible magnetic coupling between the two apertures. The coil chosen to be the baseline is a single layer with 15-mm-width cable of the LHC MQ quadrupole. The mechanical structure is based on stainless steel collars to withstand the Lorentz forces. The iron yoke has a magnetic function, and guarantees the alignment of the two apertures. Electromagnetic and mechanical aspects and effects of unbalanced regimes on the field quality have been analyzed. A 3-D design of the coil ends is obtained by minimizing both the integrated multipoles and the peak field.
The design and construction of a wide-aperture, superconducting quadrupole magnet for the LHC insertion region is part of a study towards a luminosity upgrade of the LHC at CERN. The engineering ...design of components and tooling, the procurement, and the construction work presented in this paper includes innovative features such as more porous cable insulation, a new collar structure allowing horizontal assembly with a hydraulic collaring press, tuning shims for the adjustment of field quality, a fishbone like structure for the ground-plane insulation, and an improved quench-heater design. Rapid prototyping of coil-end spacers and trial-coil winding led to improved shapes, thus avoiding the need to impregnate the ends with epoxy resin, which would block the circulation of helium. The magnet construction follows established procedures for the curing and assembly of the coils, in order to match the workflow established in CERN's "large magnet facility." This requirement led to the design and procurement of a hydraulic press allowing for both a vertical and a horizontal position of the coil-collar pack, as well as a collapsible assembly mandrel, which guarantees the pack's four-fold symmetry during collaring. The assembly process has been validated with the construction of two short models, instrumented with strain gauges and capacitive pressure transducers. This also determines the final parameters for coil curing and shim sizes.
The aim of this paper is to present an analytical modelling of chatter vibration in orthogonal cutting. With this objective, and to contribute to the understanding of self excited vibration ...phenomenon, an experimental study was first carried out. The experiments were conducted on a CNC lathe, a special setup was developed to investigate vibration in feed direction. The specimen was a tube and the tool vibrations were measured with an eddy current sensor. Vibration signals, surface roughness and chip morphologies were analysed for different set of cutting conditions in order to define the stability limits of the process. The next part of the study was the modelling of the observed vibration phenomenon. The proposed approach integrated the main sources of non-linearities. In addition, an original aspect of the approach was to associate the vibration model with an analytical thermomechanical model of cutting to estimate the dynamic cutting forces and to deduce the stability limits of the process. A parametric exploration was then presented, different ploughing effect models were evaluated. Finally, the predicted stability limits were compared with those obtained from the experimental tests and from the literature.
This paper presents a cable-driven dexterous manipulator with a large, open lumen. One specific application for the manipulator is the treatment of the degeneration of bone tissue (osteolysis) during ...a less-invasive hip revision surgery. Rigid tools used in traditional approaches limit the surgeons' ability to comprehensively treat the osteolysis due to the complex geometries of the lesion. The surgical scenario, testing, kinematic modeling, and image-based inverse kinematics are described. Testing shows 94% coverage of a lesion wall; the kinematic model describes manipulator notch positions within 0.15 mm, while the image-based inverse kinematics has 0.36 mm error. This manipulator is potentially useful in treating osteolytic lesions through (1) effective lesion exploration compared to conventional techniques, and (2) rapidly performing inverse kinematics from visual feedback.
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