| 1. |
- Redaa, A., et al.
(författare)
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Testing Nano-Powder and Fused-Glass Mineral Reference Materials for In Situ Rb-Sr Dating of Glauconite, Phlogopite, Biotite and Feldspar via LA-ICP-MS/MS
- 2023
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Ingår i: Geostandards and Geoanalytical Research. - : Wiley. - 1639-4488 .- 1751-908X. ; 47:1, s. 23-48
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Tidskriftsartikel (refereegranskat)abstract
- Reference materials (RMs) with well-characterised composition are necessary for reliable quantification and quality control of isotopic analyses of geological samples. For in situ Rb-Sr analysis of silicate minerals via laser ablation inductively coupled plasma tandem mass spectrometry (LA-ICP-MS/MS) with a collision/reaction cell, there is a general lack of mineral-specific and matrix-matched RMs, which limits wider application of this new laser-based dating technique to certain minerals. In this work, pressed nano-powder pellets (NP) of four RMs, GL-O (glauconite), Mica-Mg (phlogopite), Mica-Fe (biotite) and FK-N (K-feldspar), were analysed and tested for in situ Rb-Sr dating, complemented by isotope dilution (ID) MC-ICP-MS Rb-Sr analyses of GL-O and Mica-Mg. In addition, we attempted to develop alternative flux-free and fused 'mineral glasses' from the above RMs for in situ Rb-Sr dating applications. Overall, the results of this study showed that among the above RMs only two NP (Mica-Mg-NP and GL-O-NP) were suitable and robust for in situ dating applications. These two nano-powder reference materials, Mica-Mg-NP and GL-O-NP, were thus used as primary RMs to normalise and determine Rb-Sr ages for three natural minerals: MDC phlogopite and GL-O glauconite grains, and also Mica-Fe-NP (biotite). Our in situ analyses of the above RMs yielded Rb-Sr ages that are in good agreement (within 8%) of published ages, which suggests that both Mica-Mg-NP and GL-O-NP are suitable RMs for in situ Rb-Sr dating of phlogopite, glauconite and biotite. However, using secondary RMs is recommended to monitor the quality of the obtained ages.
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| 2. |
- 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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| 3. |
- Baldermann, A., et al.
(författare)
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Impact of green clay authigenesis on element sequestration in marine settings
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Retrograde clay mineral reactions (reverse weathering), including glauconite formation, are first-order controls on element sequestration in marine sediments. Here, we report substantial element sequestration by glauconite formation in shallow marine settings from the Triassic to the Holocene, averaging 3 +/- 2 mmol.cm(-2).kyr(-1) for K, Mg and Al, 16 +/- 9 mmol.cm(-2).kyr(-1) for Si and 6 +/- 3 mmol.cm(-2).kyr(-1) for Fe, which is similar to 2 orders of magnitude higher than estimates for deep-sea settings. Upscaling of glauconite abundances in shallow-water (0-200 m) environments predicts a present-day global uptake of similar to <= 0.1 Tmol.yr(-1) of K, Mg and Al, and similar to 0.1-0.4 Tmol.yr(-1) of Fe and Si, which is similar to half of the estimated Mesozoic elemental flux. Clay mineral authigenesis had a large impact on the global marine element cycles throughout Earth's history, in particular during 'greenhouse' periods with sea level highstand, and is key for better understanding past and present geochemical cycling in marine sediments.
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| 4. |
- Johnson, Kara A., et al.
(författare)
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Structural connectivity predicts clinical outcomes of deep brain stimulation for Tourette syndrome
- 2020
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Ingår i: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 143, s. 2607-2623
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Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation may be an effective therapy for select cases of severe, treatment-refractory Tourette syndrome; however, patient responses are variable, and there are no reliable methods to predict clinical outcomes. The objectives of this retrospective study were to identify the stimulation-dependent structural networks associated with improvements in tics and comorbid obsessive-compulsive behaviour, compare the networks across surgical targets, and determine if connectivity could be used to predict clinical outcomes. Volumes of tissue activated for a large multisite cohort of patients (n = 66) implanted bilaterally in globus pallidus internus (n = 34) or centromedial thalamus (n = 32) were used to generate probabilistic tractography to form a normative structural connectome. The tractography maps were used to identify networks that were correlated with improvement in tics or comorbid obsessive-compulsive behaviour and to predict clinical outcomes across the cohort. The correlated networks were then used to generate ‘reverse’ tractography to parcellate the total volume of stimulation across all patients to identify local regions to target or avoid. The results showed that for globus pallidus internus, connectivity to limbic networks, associative networks, caudate, thalamus, and cerebellum was positively correlated with improvement in tics; the model predicted clinical improvement scores (P = 0.003) and was robust to cross-validation. Regions near the anteromedial pallidum exhibited higher connectivity to the positively correlated networks than posteroventral pallidum, and volume of tissue activated overlap with this map was significantly correlated with tic improvement (P < 0.017). For centromedial thalamus, connectivity to sensorimotor networks, parietal-temporal-occipital networks, putamen, and cerebellum was positively correlated with tic improvement; the model predicted clinical improvement scores (P = 0.012) and was robust to cross-validation. Regions in the anterior/lateral centromedial thalamus exhibited higher connectivity to the positively correlated networks, but volume of tissue activated overlap with this map did not predict improvement (P > 0.23). For obsessive-compulsive behaviour, both targets showed that connectivity to the prefrontal cortex, orbitofrontal cortex, and cingulate cortex was positively correlated with improvement; however, only the centromedial thalamus maps predicted clinical outcomes across the cohort (P = 0.034), but the model was not robust to cross-validation. Collectively, the results demonstrate that the structural connectivity of the site of stimulation are likely important for mediating symptom improvement, and the networks involved in tic improvement may differ across surgical targets. These networks provide important insight on potential mechanisms and could be used to guide lead placement and stimulation parameter selection, as well as refine targets for neuromodulation therapies for Tourette syndrome.
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| 5. |
- Martinez-Ramirez, Daniel, et al.
(författare)
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Efficacy and Safety of Deep Brain Stimulation in Tourette Syndrome : The International Tourette Syndrome Deep Brain Stimulation Public Database and Registry
- 2018
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Ingår i: JAMA Neurology. - : American Medical Association. - 2168-6149 .- 2168-6157. ; 75:3, s. 353-359
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Collective evidence has strongly suggested that deep brain stimulation (DBS) is a promising therapy for Tourette syndrome.OBJECTIVE To assess the efficacy and safety of DBS in a multinational cohort of patients with Tourette syndrome.DESIGN, SETTING, AND PARTICIPANTS The prospective International Deep Brain Stimulation Database and Registry included 185 patients with medically refractory Tourette syndrome who underwent DBS implantation from January 1, 2012, to December 31, 2016, at 31 institutions in 10 countries worldwide.EXPOSURES Patients with medically refractory symptoms received DBS implantation in the centromedian thalamic region (93 of 163 [57.1%]), the anterior globus pallidus internus (41 of 163 [25.2%]), the posterior globus pallidus internus (25 of 163 [15.3%]), and the anterior limb of the internal capsule (4 of 163 [2.5%]).MAIN OUTCOMES AND MEASURES Scores on the Yale Global Tic Severity Scale and adverse events.RESULTS The International Deep Brain Stimulation Database and Registry enrolled 185 patients (of 171 with available data, 37 females and 134 males; mean [SD] age at surgery, 29.1 [10.8] years [range, 13-58 years]). Symptoms of obsessive-compulsive disorder were present in 97 of 151 patients (64.2%) and 32 of 148 (21.6%) had a history of self-injurious behavior. The mean (SD) total Yale Global Tic Severity Scale score improved from 75.01 (18.36) at baseline to 41.19 (20.00) at 1 year after DBS implantation (P<.001). The mean (SD) motor tic subscore improved from 21.00 (3.72) at baseline to 12.91 (5.78) after 1 year (P <.001), and the mean (SD) phonic tic subscore improved from 16.82 (6.56) at baseline to 9.63 (6.99) at 1 year (P <.001). The overall adverse event rate was 35.4%(56 of 158 patients), with intracranial hemorrhage occurring in 2 patients (1.3%), infection in 4 patients with 5 events (3.2%), and lead explantation in 1 patient (0.6%). The most common stimulation-induced adverse effects were dysarthria (10 [6.3%]) and paresthesia (13 [8.2%]).CONCLUSIONS AND RELEVANCE Deep brain stimulationwas associated with symptomatic improvement in patients with Tourette syndrome but also with important adverse events. A publicly available website on outcomes of DBS in patients with Tourette syndrome has been provided.
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| 6. |
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| 7. |
- Rivera-Ferre, Marta G., et al.
(författare)
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A vision for transdisciplinarity in Future Earth : Perspectives from young researchers
- 2013
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Ingår i: The Journal of Agriculture, Food Systems, and Community Development. - : New Leaf Associates, Inc.. - 2152-0798 .- 2152-0801. ; 3:4, s. 249-260
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Tidskriftsartikel (refereegranskat)abstract
- Meeting the demand for food, energy, and water as world population increases is a major goal for the food systems of the future. These future challenges, which are complex, multiscalar, and cross-sectoral in nature, require a food systems approach that recognizes the socio-ecological and socio-technical dimensions of food (Ericksen, 2008; Ingram, 2011; Rivera-Ferre, 2012). The United Nations' Future Earth Program aims to provide a new platform for consolidating the knowledge required for societies to transition to global sustainability (Future Earth Transition Team, 2012). In this paper, we explore how Future Earth could become a vehicle for inspiring the production of new research ideas and collaborations for sustainably transforming the future food system. We do this on the basis of a synthesis of views from 28 young (below 40 years old) food system scientists, representing five continents. Their expertise comes from disciplines including food engineering, agronomy, ecology, geography, psychology, public health, food politics, nutritional science, political science, sociology and sustainability science. This paper begins with an outline of the institutional framework of Future Earth and how it might support innovative transdisciplinary research on food systems, and the position of young scientists within this framework. Secondly, we outline the key insights expressed by the young scientists during the Food Futures Conference in Villa Vigoni, Italy, in April 2013, including the core research questions raised during the meeting as well as some of the challenges involved in realizing their research ambitions within their professional spheres.
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| 8. |
- Scheiblhofer, E., et al.
(författare)
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Revisiting Glauconite Geochronology: Lessons Learned from In Situ Radiometric Dating of a Glauconite-Rich Cretaceous Shelfal Sequence
- 2022
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Ingår i: Minerals. - : MDPI AG. - 2075-163X. ; 12:7
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Tidskriftsartikel (refereegranskat)abstract
- The scarcity of well-preserved and directly dateable sedimentary sequences is a major impediment to inferring the Earth's paleo-environmental evolution. The authigenic mineral glauconite can potentially provide absolute stratigraphic ages for sedimentary sequences and constraints on paleo-depositional conditions. This requires improved approaches for measuring and interpreting glauconite formation ages. Here, glauconite from a Cretaceous shelfal sequence (Langenstein, northern Germany) was characterized using petrographical, geochemical (EMP), andmineralogical (XRD) screening methods before in situ Rb-Sr dating via LA-ICP-MS/MS. The obtained glauconite ages (similar to 101 to 97 Ma) partly overlap with the depositional age of the Langenstein sequence (+/- 3 Ma), but without the expected stratigraphic age progression, which we attribute to detrital and diagenetic illitic phase impurities inside the glauconites. Using a novel age deconvolution approach, which combines the new Rb-Sr dataset with published K-Ar ages, we recalculate the glauconite bulk ages to obtain stratigraphically significant 'pure' glauconite ages (similar to 100 to 96 Ma). Thus, our results show that pristine ages can be preserved in mineralogically complex glauconite grains even under burial diagenetic conditions (T < 65 degrees C; <1500 m depth), confirming that glauconite could be a suitable archive for paleo-environmental reconstructions and direct sediment dating.
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