| 1. |
- Absil, Oliver, et al.
(författare)
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Three years of harvest with the vector vortex coronagraph in the thermal infrared
- 2016
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Ingår i: Ground-Based and Airborne Instrumentation for Astronomy VI. - : SPIE - International Society for Optical Engineering. - 9781510601963 ; , s. 1-14
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Konferensbidrag (refereegranskat)abstract
- For several years, we have been developing vortex phase masks based on sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto diamond substrates, these AGPMs are currently designed to be used in the thermal infrared (ranging from 3 to 13 μm). Our AGPMs were first installed on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and Keck/NIRC2 in 2015. In this paper, we review the development, commissioning, on-sky performance, and early scientific results of these new coronagraphic modes and report on the lessons learned. We conclude with perspectives for future developments and applications.
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| 2. |
- Bajbouj, Malek, et al.
(författare)
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Two-year outcome of vagus nerve stimulation in treatment-resistant depression
- 2010
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Ingår i: Journal of Clinical Psychopharmacology. - : Lippincott Williams & Wilkins. - 0271-0749 .- 1533-712X. ; 30:3, s. 273-281
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Tidskriftsartikel (refereegranskat)abstract
- One of the major goals of antidepressant treatment is a sustained response and remission of depressive symptoms. Some of the previous studies of vagus nerve stimulation (VNS) have suggested antidepressant effects. Our naturalistic study assessed the efficacy and the safety of VNS in 74 European patients with therapy-resistant major depressive disorder. Psychometric measures were obtained after 3, 12, and 24 months of VNS. Mixed-model repeated-measures analysis of variance revealed a significant reduction (P < or = 0.05) at all the 3 time points in the 28-item Hamilton Rating Scale for Depression (HRSD28) score, the primary outcome measure. After 2 years, 53.1% (26/49) of the patients fulfilled the response criteria (> or =50% reduction in the HRSD28 scores from baseline) and 38.9% (19/49) fulfilled the remission criteria (HRSD28 scores < or = 10). The proportion of patients who fulfilled the remission criteria remained constant as the duration of VNS treatment increased. Voice alteration, cough, and pain were the most frequently reported adverse effects. Two patients committed suicide during the study; no other deaths were reported. No statistically significant differences were seen in the number of concomitant antidepressant medications. The results of this 2-year open-label trial suggest a clinical response and a comparatively benign adverse effect profile among patients with treatment-resistant depression.
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| 3. |
- Castellá, Bruno Femenía, et al.
(författare)
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Commissioning and first light results of an L’-band vortex coronagraph with the Keck II adaptive optics NIRC2 science instrument
- 2016
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Ingår i: Adaptive Optics Systems V. - : SPIE - International Society for Optical Engineering.
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Konferensbidrag (refereegranskat)abstract
- On March 2015 an L'-band vortex coronagraph based on an Annular Groove Phase Mask made up of a diamond sub-wavelength grating was installed on NIRC2 as a demonstration project. This vortex coronagraph operates in the L' band not only in order to take advantage from the favorable star/planet contrast ratio when observing beyond the K band, but also to exploit the fact that the Keck II Adaptive Optics (AO) system delivers nearly extreme adaptive optics image quality (Strehl ratios values near 90%) at 3.7 mu m. We describe the hardware installation of the vortex phase mask during a routine NIRC2 service mission. The success of the project depends on extensive software development which has allowed the achievement of exquisite real-time pointing control as well as further contrast improvements by using speckle nulling to mitigate the effect of static speckles. First light of the new coronagraphic mode was on June 2015 with already very good initial results. Subsequent commissioning nights were interlaced with science nights by members of the VORTEX team with their respective scientific programs. The new capability and excellent results so far have motivated the VORTEX team and the Keck Science Steering Committee (KSSC) to offer the new mode in shared risk mode for 2016B.
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| 4. |
- Llop-Sayson, Jorge, et al.
(författare)
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Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multiepoch Vortex Coronagraphy Upper Limits
- 2021
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Ingår i: Astronomical Journal. - : Institute of Physics Publishing (IOPP). - 0004-6256 .- 1538-3881. ; 162:5
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Tidskriftsartikel (refereegranskat)abstract
- epsilon Eridani is a young planetary system hosting a complex multibelt debris disk and a confirmed Jupiter-like planet orbiting at 3.48 au from its host star. Its age and architecture are thus reminiscent of the early Solar System. The most recent study of Mawet et al., which combined radial-velocity data and Ms-band direct imaging upper limits, started to constrain the planet's orbital parameters and mass, but are still affected by large error bars and degeneracies. Here we make use of the most recent data compilation from three different techniques to further refine epsilon Eridani b's properties: RVs, absolute astrometry measurements from the Hipparcos and Gaia missions, and new Keck/NIRC2 Ms-band vortex coronagraph images. We combine this data in a Bayesian framework. We find a new mass, M-b = 0.66(-0.09)(+0.12) M-Jup, and inclination, i = 78.81(-22.41 degrees)(+29.34), with at least a factor 2 of improvement over previous uncertainties. We also report updated constraints on the longitude of the ascending node, the argument of the periastron, and the time of periastron passage. With these updated parameters, we can better predict the position of the planet at any past and future epoch, which can greatly help define the strategy and planning of future observations and with subsequent data analysis. In particular, these results can assist the search for a direct detection with JWST and the Nancy Grace Roman Space Telescope's coronagraph instrument.
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| 5. |
- Mawet, Dimitri, et al.
(författare)
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Characterization of the inner disk around HD 141569 A from KECK/NIRC2 L-band vortex coronagraphy
- 2017
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 153:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- HD 141569 A is a pre-main sequence B9.5 Ve star surrounded by a prominent and complex circumstellar disk, likely still in a transition stage from protoplanetary to debris disk phase. Here, we present a new image of the third inner disk component of HD 141569 A made in the L′ band (3.8 μm) during the commissioning of the vector vortex coronagraph that has recently been installed in the near-infrared imager and spectrograph NIRC2 behind the W. M. Keck Observatory Keck II adaptive optics system. We used reference point-spread function subtraction, which reveals the innermost disk component from the inner working distance of ;23 au and up to ;70 au. The spatial scale of our detection roughly corresponds to the optical and near-infrared scattered light, thermal Q, N, and 8.6 μm PAH emission reported earlier. We also see an outward progression in dust location from the L′ band to the H band (Very Large Telescope/ SPHERE image) to the visible (Hubble Space Telescope (HST)/ STIS image), which is likely indicative of dust blowout. The warm disk component is nested deep inside the two outer belts imaged by HST-NICMOS in 1999 ( at 406 and 245 au, respectively) . We fit our new L′ -band image and spectral energy distribution of HD 141569 A with the radiative transfer code MCFOST. Our best-fit models favor pure olivine grains and are consistent with the composition of the outer belts. While our image shows a putative very faint point-like clump or source embedded in the inner disk, we did not detect any true companion within the gap between the inner disk and the first outer ring, at a sensitivity of a few Jupiter masses.
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| 6. |
- Naesström, Matilda, 1987-
(författare)
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Deep brain stimulation in obsessive-compulsive disorder
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Deep brain stimulation (DBS) is under investigation for severe obsessive-compulsive disorder (OCD) resistant to other therapies. As a crucial part of the anxiety circuit in the brain, the bed nucleus of stria terminalis (BNST) has been proposed as a target for DBS in OCD. However, the mechanism of action of BNST DBS in OCD is not yet fully understood. In our studies, the aim was to evaluate the effect and side effects of DBS in the BNST in severe OCD, to investigate which anatomical areas are being affected by the stimulation and what could be the potential mechanism of action of DBS in this target. We also explored the knowledge and concerns regarding DBS in OCD among psychiatrists, psychotherapists and patients suffering from the disorder. We investigate clinical outcomes and safety of DBS in the BNST in a series of 11 participants with severe therapy-refractory OCD. The primary outcome was a change in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) scores one year after surgery. Using image and stimulation parameter data from the study above, we investigate through participant-specific simulation of the electric field, which anatomical areas are affected by the electric field, and if this can be related to the clinical results. Six of the participants were evaluated with symptom provocation fMRI pre-operatively and in DBS ON and OFF conditions. A web-based study surveyed psychiatrists, patients, and cognitive-behavioural therapists regarding previous knowledge of DBS, source of knowledge, attitudes, and concerns towards the therapy.At baseline, the mean±SD YBOCS score was 33±3.0. One year after DBS, mean±SD YBOCS score was 20±4.8 (38% improvement (range 10- 60%) p <0.01). Of the 11 participants, six were considered responders (decrease in YBOCS ≥35%) and four partial responders (decrease in YBOCS 25-34%). Surgical adverse events included one case of skin infection leading to reimplantation. The most common transient stimulation-related side-effects were anxiety and insomnia. The individual electric stimulation fields by stimulation in the BNST were similar at the 12 and 24-months follow up, involving mainly the anterior limb of the internal capsule (ALIC), genu of the internal capsule, BNST, fornix, anteromedial globus pallidus externa (GPe) and the anterior commissure. A statistically significant correlation (p < 0.05) between clinical effect measured by the YBOCS and simulation was found at the 12-month follow-up in the ventral ALIC and anteromedial GPe. A significant decrease in anxiety-related brain activity in the pre-supplementary motor area (pre-SMA) and the anterior insula was seen in 3/6 participants, with a comparable reduction (below significance level) in the other three participants. Results from the survey found that the primary source of information was from scientific sources among psychiatrists and psychotherapists. The patients' primary source of information was the media. Common concerns among the groups included complications from surgery, anaesthesia, stimulation side effects, and the novelty of the treatment. Specific concerns for the groups included; personality changes mentioned by patients and psychotherapists and ethical concerns among psychiatrists.BNST DBS is a promising therapy in severe therapy-refractory OCD. Our results are in line with previous publications regarding effect and safety profiles. We hypothesise that possible mechanisms of BNST DBS in OCD could be modulation of anxiety-related activity in the pre-SMA and anterior insula, two regions that play an important role in the pathophysiology of OCD. Many of the targets under investigation for OCD are in anatomical proximity, and as seen in our study, offtarget effects overlap. Therefore, DBS in the region of ALIC, NA, and BNST may perhaps be considered to be stimulation of the same target. DBS challenges in obsessive-compulsive disorder consist of source and quality of information, potential long-term adverse effects and eligibility. A broad research agenda is needed for studies as we advance in this field.
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| 7. |
- Nuttin, Bart, et al.
(författare)
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Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders
- 2014
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Ingår i: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ Publishing Group. - 0022-3050 .- 1468-330X. ; 85:9, s. 1003-1008
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Tidskriftsartikel (refereegranskat)abstract
- Background For patients with psychiatric illnesses remaining refractory to 'tandard' therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. Methods To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. Findings The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered 'stablished' in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-p evaluation, and reporting of effects and side effects for all patients. Interpretation This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety.
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| 8. |
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| 9. |
- Tyagi, Himanshu, et al.
(författare)
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A randomized trial directly comparing ventral capsule and anteromedial subthalamic nucleus stimulation in obsessive-compulsive disorder : Clinical and imaging evidence for dissociable effects
- 2022
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Ingår i: FOCUS. - : American Psychiatric Association Publishing. - 1541-4094 .- 1541-4108. ; 20:1, s. 160-169
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Tidskriftsartikel (refereegranskat)abstract
- Background: Deep brain stimulation (DBS) is an emerging treatment for severe obsessive-compulsive disorder (OCD). We compared the efficacy of ventral capsule/ventral striatal (VC/VS) and anteromedial subthalamic nucleus (amSTN) DBS in the same patients and tested for mechanistic differences on mood and cognitive flexibility and associated neural circuitry. The possible synergistic benefit of DBS at both sites and cognitive behavioral therapy was explored.Methods: Six patients with treatment-refractory OCD (5 men; Yale-Brown Obsessive Compulsive Scale score >32) entered double-blind counterbalanced phases of 12-week amSTN or VC/VS DBS, followed by 12-week open phases when amSTN and VC/VS were stimulated together, in which optimal stimulation parameters were achieved and adjunctive inpatient cognitive behavioral therapy was delivered. OCD and mood were assessed with standardized scales and cognitive flexibility with the Cambridge Neuropsychological Test Automated Battery Intra-Extra Dimensional Set-Shift task. Diffusion-weighted and intraoperative magnetic resonance imaging scans were performed for tractography from optimally activated electrode contacts.Results: DBS at each site significantly and equivalently reduced OCD symptoms with little additional gain following combined stimulation. amSTN but not VC/VS DBS significantly improved cognitive flexibility, whereas VC/VS DBS had a greater effect on mood. The VC/VS effective site was within the VC. VC DBS connected primarily to the medial orbitofrontal cortex, and amSTN DBS to the lateral orbitofrontal cortex, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex. No further improvement followed cognitive behavioral therapy, reflecting a floor effect of DBS on OCD.Conclusions: Both the VC/VS and amSTN are effective targets for severe treatment-refractory OCD. Differential improvements in mood and cognitive flexibility and their associated connectivity suggest that DBS at these sites modulates distinct brain networks.
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| 10. |
- Visser-Vandewalle, Veerle, et al.
(författare)
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Deep brain stimulation for obsessive-compulsive disorder : a crisis of access
- 2022
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Ingår i: Nature Medicine. - : Nature Publishing Group. - 1078-8956 .- 1546-170X. ; 28:8, s. 1529-1532
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Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation is an effective treatment for obsessive–compulsive disorder but is rarely used. Action is needed by psychologists, psychiatrists and insurers so that patients with otherwise intractable cases can receive this therapy to improve their mental health.
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