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3. |
- Bakken, TE, et al.
(författare)
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Comparative cellular analysis of motor cortex in human, marmoset and mouse
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 598:7879, s. 111-
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Tidskriftsartikel (refereegranskat)abstract
- The primary motor cortex (M1) is essential for voluntary fine-motor control and is functionally conserved across mammals1. Here, using high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmoset monkeys and mice, we demonstrate a broadly conserved cellular makeup of this region, with similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. The core conserved molecular identities of neuronal and non-neuronal cell types allow us to generate a cross-species consensus classification of cell types, and to infer conserved properties of cell types across species. Despite the overall conservation, however, many species-dependent specializations are apparent, including differences in cell-type proportions, gene expression, DNA methylation and chromatin state. Few cell-type marker genes are conserved across species, revealing a short list of candidate genes and regulatory mechanisms that are responsible for conserved features of homologous cell types, such as the GABAergic chandelier cells. This consensus transcriptomic classification allows us to use patch–seq (a combination of whole-cell patch-clamp recordings, RNA sequencing and morphological characterization) to identify corticospinal Betz cells from layer 5 in non-human primates and humans, and to characterize their highly specialized physiology and anatomy. These findings highlight the robust molecular underpinnings of cell-type diversity in M1 across mammals, and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations.
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4. |
- Schluter, J., et al.
(författare)
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The gut microbiota is associated with immune cell dynamics in humans
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 588:7837, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- Influence of the gut microbiome on the human immune system is revealed by systems analysis of vast clinical data from decades of electronic health records paired with massive longitudinal microbiome sequencing. The gut microbiota influences development(1-3) and homeostasis(4-7) of the mammalian immune system, and is associated with human inflammatory(8) and immune diseases(9,10) as well as responses to immunotherapy(11-14). Nevertheless, our understanding of how gut bacteria modulate the immune system remains limited, particularly in humans, where the difficulty of direct experimentation makes inference challenging. Here we study hundreds of hospitalized-and closely monitored-patients with cancer receiving haematopoietic cell transplantation as they recover from chemotherapy and stem-cell engraftment. This aggressive treatment causes large shifts in both circulatory immune cell and microbiota populations, enabling the relationships between the two to be studied simultaneously. Analysis of observed daily changes in circulating neutrophil, lymphocyte and monocyte counts and more than 10,000 longitudinal microbiota samples revealed consistent associations between gut bacteria and immune cell dynamics. High-resolution clinical metadata and Bayesian inference allowed us to compare the effects of bacterial genera in relation to those of immunomodulatory medications, revealing a considerable influence of the gut microbiota-together and over time-on systemic immune cell dynamics. Our analysis establishes and quantifies the link between the gut microbiota and the human immune system, with implications for microbiota-driven modulation of immunity.
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5. |
- Hall, C. Michael, et al.
(författare)
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Denying bogus skepticism in climate change and tourism research.
- 2015
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Ingår i: Tourism Management. - : Elsevier BV. - 0261-5177 .- 1879-3193. ; 47, s. 352-356
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Tidskriftsartikel (refereegranskat)abstract
- This final response to the two climate change denial papers by Shani and Arad further highlights the inaccuracies, misinformation and errors in their commentaries. The obfuscation of scientific research and the consensus on anthropogenic climate change may have significant long-term negative consequences for better understanding the implications of climate change and climate policy for tourism and create confusion and delay in developing and implementing tourism sector responses.
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6. |
- Hall, C. Michael, et al.
(författare)
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No time for smokescreen skepticism : A rejoinder to Shani and Arad
- 2015
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Ingår i: Tourism Management. - : Elsevier BV. - 0261-5177 .- 1879-3193. ; 47, s. 341-347
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Tidskriftsartikel (refereegranskat)abstract
- Shani and Arad (2014) claimed that tourism scholars tend to endorse the most pessimistic assessments regarding climate change, and that anthropogenic climate change was a "fashionable" and "highly controversial scientific topic". This brief rejoinder provides the balance that is missing from such climate change denial and skepticism studies on climate change and tourism. Recent research provides substantial evidence that reports on anthropogenic climate change are accurate, and that human-induced greenhouse gas emissions, including from the tourism industry, play a significant role in climate change. Some positive net effects may be experienced by some destinations in the short-term, but in the long-term all elements of the tourism system will be impacted. The expansion of tourism emissions at a rate greater than efficiency gains means that it is increasingly urgent that the tourism sector acknowledge, accept and respond to climate change. Debate on tourism-related adaptation and mitigation measures is to be encouraged and welcomed. Climate change denial is not.
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8. |
- Murawski, Christopher D., et al.
(författare)
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Terminology for osteochondral lesions of the ankle: proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle
- 2022
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Ingår i: JOURNAL OF ISAKOS JOINT DISORDERS & ORTHOPAEDIC SPORTS MEDICINE. - : Elsevier BV. - 2059-7754 .- 2059-7762. ; 7:2, s. 62-66
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Tidskriftsartikel (refereegranskat)abstract
- Background: The evidence supporting best practice guidelines in the field of cartilage repair of the ankle is based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on "terminology for osteochondral lesions of the ankle" developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. Methods: Forty-three international experts in cartilage repair of the ankle representing 20 countries were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within four working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed, and the available evidence for each state-ment was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterised as follows: consensus, 51%-74%; strong consensus, 75%-99%; unanimous, 100%. Results: A total of 11 statements on terminology and classification reached consensus during the 2019 Interna-tional Consensus Meeting on Cartilage Repair of the Ankle. Definitions are provided for osseous, chondral and osteochondral lesions, as well as bone marrow stimulation and injury chronicity, among others. An osteochondral lesion of the talus can be abbreviated as OLT. Conclusions: This international consensus derived from leaders in the field will assist clinicians with the appro-priate terminology for osteochondral lesions of the ankle.
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9. |
- Estanqueiro, A., et al.
(författare)
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Energy storage for wind integration : Hydropower and other contributions
- 2012
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Ingår i: Power and Energy Society General Meeting, 2012 IEEE. - : IEEE. - 9781467327275 ; , s. 6344652-
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Konferensbidrag (refereegranskat)abstract
- The amount of wind power and other timevariable non-dispatchable renewable energy sources (RES) is rapidly increasing in the world. A few power systems are already facing very high penetrations from variable renewables which can surpass the systems' consumption during no-load periods, requiring the energy excess to be curtailed, exported or stored. The limitations of electric energy storage naturally lead to the selection of the well-known form of storing potential energy in reservoirs of reversible hydropower stations, although other technologies such as heat storage are also being used successfully. This paper reviews the storage technologies that are available and may be used on a power system scale and compares their advantages and disadvantages for the integration of fast-growing renewables, such as wind power, with a special focus on the role of pumped hydro storage.
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10. |
- Fernandez, Hubert H., et al.
(författare)
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Levodopa-Carbidopa Intestinal Gel in Advanced Parkinson's Disease: Final 12-Month, Open-Label Results
- 2015
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 30:4, s. 500-509
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Tidskriftsartikel (refereegranskat)abstract
- Motor complications in Parkinson's disease (PD) are associated with long-term oral levodopa treatment and linked to pulsatile dopaminergic stimulation. l-dopa-carbidopa intestinal gel (LCIG) is delivered continuously by percutaneous endoscopic gastrojejunostomy tube (PEG-J), which reduces l-dopa-plasma-level fluctuations and can translate to reduced motor complications. We present final results of the largest international, prospective, 54-week, open-label LCIG study. PD patients with severe motor fluctuations (>3 h/day off time) despite optimized therapy received LCIG monotherapy. Additional PD medications were allowed >28 days post-LCIG initiation. Safety was the primary endpoint measured through adverse events (AEs), device complications, and number of completers. Secondary endpoints included diary-assessed off time, on time with/without troublesome dyskinesia, UPDRS, and health-related quality-of-life (HRQoL) outcomes. Of 354 enrolled patients, 324 (91.5%) received PEG-J and 272 (76.8%) completed the study. Most AEs were mild/moderate and transient; complication of device insertion (34.9%) was the most common. Twenty-seven (7.6%) patients withdrew because of AEs. Serious AEs occurred in 105 (32.4%), most commonly complication of device insertion (6.5%). Mean daily off time decreased by 4.4 h/65.6% (P<0.001). On time without troublesome dyskinesia increased by 4.8 h/62.9% (P<0.001); on time with troublesome dyskinesia decreased by 0.4 h/22.5% (P=0.023). Improvements persisted from week 4 through study completion. UPDRS and HRQoL outcomes were also improved throughout. In the advanced PD population, LCIG's safety profile consisted primarily of AEs associated with the device/procedure, l-dopa/carbidopa, and advanced PD. LCIG was generally well tolerated and demonstrated clinically significant improvements in motor function, daily activities, and HRQoL sustained over 54 weeks. (c) 2014 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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11. |
- Lang, Anthony E, et al.
(författare)
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Integrated Safety of Levodopa-Carbidopa Intestinal Gel From Prospective Clinical Trials.
- 2016
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 31:4, s. 538-546
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Tidskriftsartikel (refereegranskat)abstract
- Continuous administration of levodopa-carbidopa intestinal gel (carbidopa-levodopa enteral suspension) through a percutaneous endoscopic gastrojejunostomy is a treatment option for advanced Parkinson disease (PD) patients with motor fluctuations resistant to standard oral medications. Safety data from 4 prospective studies were integrated to assess the safety of this therapy.
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12. |
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13. |
- Hall, C. Michael, et al.
(författare)
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Tourism conceptualizations, disciplinarity, institutions, and issues
- 2014
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Ingår i: The Wiley Blackwell Companion to Tourism. - Oxford, UK : John Wiley & Sons. - 9781118474648 - 9781118474488 ; , s. 3-24
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Conceptual challenges in the study of tourism include defining the parameters of tourism, which can be approached from economic, experiential, and mobility perspectives, each of which in itself is a contested landscape for those seeking to deconstruct the significance of the tourism phenomenon. This is especially an issue for the somewhat tentative efforts to define tourism as not only an interdisciplinary field of research, but also as an emerging academic discipline within the academy of higher learning, evidence for which is seen in the growth in university tourism programs, professional associations, and publications. Interdisciplinarity, however, can also be a weakness leading to a lack of shared ontological and epistemological bases for theory building. A review of tourism publication topics shows that applied and business-oriented research tends to dominate in tourism studies, with marketing and economic topics being prominent. Major areas of research focus from a geographical perspective include environmental and sustainability issues, along with destination, community, and place studies.
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15. |
- Kaplan, Lew, et al.
(författare)
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Retinal regions shape human and murine Müller cell proteome profile and functionality
- 2023
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Ingår i: GLIA. - : Wiley. - 0894-1491 .- 1098-1136. ; 71:2, s. 391-414
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Tidskriftsartikel (refereegranskat)abstract
- The human macula is a highly specialized retinal region with pit-like morphology and rich in cones. How Müller cells, the principal glial cell type in the retina, are adapted to this environment is still poorly understood. We compared proteomic data from cone- and rod-rich retinae from human and mice and identified different expression profiles of cone- and rod-associated Müller cells that converged on pathways representing extracellular matrix and cell adhesion. In particular, epiplakin (EPPK1), which is thought to play a role in intermediate filament organization, was highly expressed in macular Müller cells. Furthermore, EPPK1 knockout in a human Müller cell-derived cell line led to a decrease in traction forces as well as to changes in cell size, shape, and filopodia characteristics. We here identified EPPK1 as a central molecular player in the region-specific architecture of the human retina, which likely enables specific functions under the immense mechanical loads in vivo.
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16. |
- Lampl, Yair, et al.
(författare)
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Infrared laser therapy for ischemic stroke : a new treatment strategy
- 2007
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Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 38:6, s. 1843-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The NeuroThera Effectiveness and Safety Trial-1 (NEST-1) study evaluated the safety and preliminary effectiveness of the NeuroThera Laser System in the ability to improve 90-day outcomes in ischemic stroke patients treated within 24 hours from stroke onset. The NeuroThera Laser System therapeutic approach involves use of infrared laser technology and has shown significant and sustained beneficial effects in animal models of ischemic stroke.METHODS: This was a prospective, intention-to-treat, multicenter, international, double-blind, trial involving 120 ischemic stroke patients treated, randomized 2:1 ratio, with 79 patients in the active treatment group and 41 in the sham (placebo) control group. Only patients with baseline stroke severity measured by National Institutes of Health Stroke Scale (NIHSS) scores of 7 to 22 were included. Patients who received tissue plasminogen activator were excluded. Outcome measures were the patients' scores on the NIHSS, modified Rankin Scale (mRS), Barthel Index, and Glasgow Outcome Scale at 90 days after treatment. The primary outcome measure, prospectively identified, was successful treatment, documented by NIHSS. This was defined as a complete recovery at day 90 (NIHSS 0 to 1), or a decrease in NIHSS score of at least 9 points (day 90 versus baseline), and was tested as a binary measure (bNIH). Secondary outcome measures included mRS, Barthel Index, and Glasgow Outcome Scale. Primary statistical analyses were performed with the Cochran-Mantel-Haenszel rank test, stratified by baseline NIHSS score or by time to treatment for the bNIH and mRS. Logistic regression analyses were conducted to confirm the results.RESULTS: Mean time to treatment was >16 hours (median time to treatment 18 hours for active and 17 hours for control). Time to treatment ranged from 2 to 24 hours. More patients (70%) in the active treatment group had successful outcomes than did controls (51%), as measured prospectively on the bNIH (P=0.035 stratified by severity and time to treatment; P=0.048 stratified only by severity). Similarly, more patients (59%) had successful outcomes than did controls (44%) as measured at 90 days as a binary mRS score of 0 to 2 (P=0.034 stratified by severity and time to treatment; P=0.043 stratified only by severity). Also, more patients in the active treatment group had successful outcomes than controls as measured by the change in mean NIHSS score from baseline to 90 days (P=0.021 stratified by time to treatment) and the full mRS ("shift in Rankin") score (P=0.020 stratified by severity and time to treatment; P=0.026 stratified only by severity). The prevalence odds ratio for bNIH was 1.40 (95% CI, 1.01 to 1.93) and for binary mRS was 1.38 (95% CI, 1.03 to 1.83), controlling for baseline severity. Similar results held for the Barthel Index and Glasgow Outcome Scale. Mortality rates and serious adverse events (SAEs) did not differ significantly (8.9% and 25.3% for active 9.8% and 36.6% for control, respectively, for mortality and SAEs).CONCLUSIONS: The NEST-1 study indicates that infrared laser therapy has shown initial safety and effectiveness for the treatment of ischemic stroke in humans when initiated within 24 hours of stroke onset. A larger confirmatory trial to demonstrate safety and effectiveness is warranted.
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17. |
- Lampl, Y., et al.
(författare)
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Infrared laser therapy for ischemic stroke: a new treatment strategy: results of the NeuroThera Effectiveness and Safety Trial-1 (NEST-1)
- 2007
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Ingår i: Stroke. - 1524-4628. ; 38:6, s. 1843-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The NeuroThera Effectiveness and Safety Trial-1 (NEST-1) study evaluated the safety and preliminary effectiveness of the NeuroThera Laser System in the ability to improve 90-day outcomes in ischemic stroke patients treated within 24 hours from stroke onset. The NeuroThera Laser System therapeutic approach involves use of infrared laser technology and has shown significant and sustained beneficial effects in animal models of ischemic stroke. METHODS: This was a prospective, intention-to-treat, multicenter, international, double-blind, trial involving 120 ischemic stroke patients treated, randomized 2:1 ratio, with 79 patients in the active treatment group and 41 in the sham (placebo) control group. Only patients with baseline stroke severity measured by National Institutes of Health Stroke Scale (NIHSS) scores of 7 to 22 were included. Patients who received tissue plasminogen activator were excluded. Outcome measures were the patients' scores on the NIHSS, modified Rankin Scale (mRS), Barthel Index, and Glasgow Outcome Scale at 90 days after treatment. The primary outcome measure, prospectively identified, was successful treatment, documented by NIHSS. This was defined as a complete recovery at day 90 (NIHSS 0 to 1), or a decrease in NIHSS score of at least 9 points (day 90 versus baseline), and was tested as a binary measure (bNIH). Secondary outcome measures included mRS, Barthel Index, and Glasgow Outcome Scale. Primary statistical analyses were performed with the Cochran-Mantel-Haenszel rank test, stratified by baseline NIHSS score or by time to treatment for the bNIH and mRS. Logistic regression analyses were conducted to confirm the results. RESULTS: Mean time to treatment was >16 hours (median time to treatment 18 hours for active and 17 hours for control). Time to treatment ranged from 2 to 24 hours. More patients (70%) in the active treatment group had successful outcomes than did controls (51%), as measured prospectively on the bNIH (P=0.035 stratified by severity and time to treatment; P=0.048 stratified only by severity). Similarly, more patients (59%) had successful outcomes than did controls (44%) as measured at 90 days as a binary mRS score of 0 to 2 (P=0.034 stratified by severity and time to treatment; P=0.043 stratified only by severity). Also, more patients in the active treatment group had successful outcomes than controls as measured by the change in mean NIHSS score from baseline to 90 days (P=0.021 stratified by time to treatment) and the full mRS ("shift in Rankin") score (P=0.020 stratified by severity and time to treatment; P=0.026 stratified only by severity). The prevalence odds ratio for bNIH was 1.40 (95% CI, 1.01 to 1.93) and for binary mRS was 1.38 (95% CI, 1.03 to 1.83), controlling for baseline severity. Similar results held for the Barthel Index and Glasgow Outcome Scale. Mortality rates and serious adverse events (SAEs) did not differ significantly (8.9% and 25.3% for active 9.8% and 36.6% for control, respectively, for mortality and SAEs). CONCLUSIONS: The NEST-1 study indicates that infrared laser therapy has shown initial safety and effectiveness for the treatment of ischemic stroke in humans when initiated within 24 hours of stroke onset. A larger confirmatory trial to demonstrate safety and effectiveness is warranted.
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18. |
- Rocha, W. R.M., et al.
(författare)
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JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions: I. CH4, SO2, HCOO, OCN, H2CO, HCOOH, CH3CH2OH, CH3CHO, CH3OCHO, and CH3COOH
- 2024
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 683
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Tidskriftsartikel (refereegranskat)abstract
- Context. Complex organic molecules (COMs) are ubiquitously detected in the gas phase and thought to be mostly formed on icy grains. Nevertheless, there have not been any unambiguous detections of COMs larger than CH3OH in ices reported thus far. Exploring this matter in greater detail has now become possible with the unprecedented possibilities offered by the James Webb Space Telescope (JWST) within the infrared (IR) spectral range with its very high sensitivity and spectral resolution in the critical 5 10 μm range, the fingerprint region of oxygen-bearing COMs. Aims. In the JWST Observations of Young protoStars (JOYS+) program, more than 30 protostars are undergoing observation with the Medium Resolution Spectrograph (MRS) of the Mid-IR Instrument (MIRI). The goal of this study is to comprehensively explore the COMs ice signatures in one low- and one high-mass protostar: NGC 1333 IRAS 2A and IRAS 23385+6053, respectively. Methods. We performed global continuum and silicate subtractions of the MIRI-MRS spectra, followed by a local continuum subtraction in optical depth scale in the range around 6.8 and 8.6 μm, the ice COM fingerprint region. We explored different choices for the local continuum and silicate subtraction. Next, we fit the observational data with a large sample of available IR laboratory ice spectra. We used the ENIIGMA fitting tool, a genetic algorithm-based code that not only finds the best fit between the lab data and the observations, but also performs a statistical analysis of the solutions, such as deriving the confidence intervals and quantifying fit degeneracy. Results. We report the best fits for the spectral ranges between 6.8 and 8.6 μm in NGC 1333 IRAS 2A and IRAS 23385+6053, originating from simple molecules and COMs, as well as negative ions. Overall, we find that ten chemical species are needed to reproduce the astronomical data. The strongest feature in this range (7.7 μm) is dominated by CH4, with contributions from SO2 and OCN. Our results indicate that the 7.2 and 7.4 μm bands are mostly dominated by HCOO. We also find statistically robust detections of COMs based on multiple bands, most notably, CH3CHO, CH3CH2OH, and CH3OCHO. We also report a likely detection of CH3COOH. Based on the ice column density ratios between CH3CH2OH and CH3CHO of NGC 1333 IRAS 2A and IRAS 23385+6053, we find compelling evidence that these COMs are formed on icy grains. Finally, the derived ice abundances for NGC 1333 IRAS 2A correlate well with those in comet 67P/GC within a factor of 5. Conclusions. Based on the high-quality JWST (MIRI-MRS) spectra, we conclude that COMs are present in interstellar ices, thus providing additional proof for the solid-state origin of these species in star-forming regions. In addition, the good correlation between the ice abundances in comet 67P and NGC 1333 IRAS 2A is fully in line with the idea that cometary COMs may be inherited from the early protostellar phases to a significant extent.
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19. |
- Stendahl, Olle, et al.
(författare)
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Redistribution of intracellular Ca2+ stores during phagocytosis in human neutrophils
- 1994
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 265:5177, s. 1439-1441
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Tidskriftsartikel (refereegranskat)abstract
- Subcellular gradients of cytosolic free Ca2+ concentration, [Ca2+]i, are thought to be critical for the localization of functional responses within a cell. A potential but previously unexplored mechanism for the generation of gradients of [Ca2+]i is the accumulation of Ca2+ stores at the site of Ca2+ action. The distribution of the Ca2+ store markers Ca(2+)-dependent adenosine triphosphatase and calreticulin was investigated in resting and phagocytosing human neutrophils. Both proteins showed an evenly distributed fine granular pattern in nonphagocytosing cells, but became markedly concentrated in the filamentous actin-rich cytoplasmic area around the ingested particle during phagocytosis. This redistribution began at early stages of phagocytosis and did not depend on an increase in [Ca2+]i. Thus, accumulation of Ca2+ stores in a restricted area of the cell may contribute to the generation of localized increases in [Ca2+]i.
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20. |
- Van Gelder, M. L., et al.
(författare)
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JOYS+: Mid-infrared detection of gas-phase SO 2 emission in a low-mass protostar
- 2024
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 682
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Tidskriftsartikel (refereegranskat)abstract
- Context. Thanks to the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST), our ability to observe the star formation process in the infrared has greatly improved. Due to its unprecedented spatial and spectral resolution and sensitivity in the mid-infrared, JWST/MIRI can see through highly extincted protostellar envelopes and probe the warm inner regions. An abundant molecule in these warm inner regions is SO2, which is a common tracer of both outflow and accretion shocks as well as hot core chemistry. Aims. This paper presents the first mid-infrared detection of gaseous SO2 emission in an embedded low-mass protostellar system rich in complex molecules and aims to determine the physical origin of the SO2 emission. Methods. JWST/MIRI observations taken with the Medium Resolution Spectrometer (MRS) of the low-mass protostellar binary NGC 1333 IRAS 2A in the JWST Observations of Young protoStars (JOYS+) program are presented. The observations reveal emission from the SO2 ν3 asymmetric stretching mode at 7.35 µm. Using simple slab models and assuming local thermodynamic equilibrium (LTE), we derived the rotational temperature and total number of SO2 molecules. We then compared the results to those derived from high-angular-resolution SO2 data on the same scales (∼50−100 au) obtained with the Atacama Large Millimeter/submillimeter Array (ALMA). Results. The SO2 emission from the ν3 band is predominantly located on ∼50−100 au scales around the mid-infrared continuum peak of the main component of the binary, IRAS 2A1. A rotational temperature of 92 ± 8 K is derived from the ν3 lines. This is in good agreement with the rotational temperature derived from pure rotational lines in the vibrational ground state (i.e., ν = 0) with ALMA (104 ± 5 K), which are extended over similar scales. However, the emission of the ν3 lines in the MIRI-MRS spectrum is not in LTE given that the total number of molecules predicted by a LTE model is found to be a factor of 2 × 104 higher than what is derived for the ν = 0 state from the ALMA data. This difference can be explained by a vibrational temperature that is ∼100 K higher than the derived rotational temperature of the ν = 0 state: Tvib ∼ 200 K versus Trot = 104 ± 5 K. The brightness temperature derived from the continuum around the ν3 band (∼7.35 µm) of SO2 is ∼180 K, which confirms that the ν3 = 1 level is not collisionally populated but rather infrared-pumped by scattered radiation. This is also consistent with the non-detection of the ν2 bending mode at 18−20 µm. The similar rotational temperature derived from the MIRI-MRS and ALMA data implies that they are in fact tracing the same molecular gas. The inferred abundance of SO2 , determined using the LTE fit to the lines of the vibrational ground state in the ALMA data, is 1.0 ± 0.3 × 10−8 with respect to H2, which is on the lower side compared to interstellar and cometary ices (10−8−10−7). Conclusions. Given the rotational temperature, the extent of the emission (∼100 au in radius), and the narrow line widths in the ALMA data (∼3.5 km s−1), the SO2 in IRAS 2A likely originates from ice sublimation in the central hot core around the protostar rather than from an accretion shock at the disk–envelope boundary. Furthermore, this paper shows the importance of radiative pumping and of combining JWST observations with those from millimeter interferometers such as ALMA to probe the physics on disk scales and to infer molecular abundances.
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21. |
- Woodman, Tim, et al.
(författare)
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Emotions and sport performance : An exploration of happiness, hope and anger
- 2009
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Ingår i: Journal of Sport and Exercise Psychology. - : Human Kinetics. - 0895-2779. ; 31:2, s. 169-188
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We conducted three experiments to examine the relationships between emotions and subcomponents of performance. Experiment 1 revealed that anger was associated with enhanced gross muscular peak force performance but that happiness did not influence grammatical reasoning performance. Following Lazarus (1991, 2000a), we examined hope rather than happiness in Experiment 2. As hypothesized, hope yielded faster soccer-related reaction times in soccer players. Experiment 3 was an examination of extraversion as a moderator of the anger-performance relationship. When angry, extraverts' peak force increased more than introverts'. Results are discussed and future research directions are offered in relation to Lazarus's framework.
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22. |
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23. |
- Zhou, Feng, et al.
(författare)
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Thermal conductivity of indium arsenide nanowires with wurtzite and zinc blende phases
- 2011
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 83:20
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Tidskriftsartikel (refereegranskat)abstract
- The thermal conductivity of wurtzite and zinc blende indium arsenide nanowires was measured using a microfabricated device, with the crystal structure of each sample controlled during growth and determined by transmission electron microscopy. Nanowires of both phases showed a reduction of the thermal conductivity by a factor of 2 or more compared to values reported for zinc blende indium arsenide bulk crystals within the measured temperature range. Theoretical models were developed to analyze the measurement results and determine the effect of phase on phonon transport. Branch-specific phonon dispersion data within the discretized first Brillouin zone were calculated from first principles and used in numerical models of volumetric heat capacity and thermal conductivity. The combined results of the experimental and theoretical studies suggest that wurtzite indium arsenide possesses similar volumetric heat capacity, weighted average group velocity, weighted average phonon-phonon scattering mean free path, and anharmonic scattering-limited thermal conductivity as the zinc blende phase. Hence, we attribute the differing thermal conductivity values observed in the indium arsenide nanowires of different phases to differences in the surface scattering mean free paths between the nanowire samples.
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24. |
- Zillinger, Malin, 1975-
(författare)
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Guided tourism : the role of guidebooks in German tourist behaviour in Sweden
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tourism is a spatial phenomenon. Tourist behaviour on-site is not only dependent on the destination itself, but also on the situation in other places, tourists’ spatial mobility and access to information. On the basis of this argument, the whole tourism system is taken into account in this thesis. The aim is to analyse the interplay between mobility, tourist behaviour and guidebooks. The focus lies on German tourists in Sweden. Due to the importance of guidebooks to this visitor group, the thesis concentrates particularly on guidebooks as source of information.In the first article, power relations that steer the selection of Swedish tourist sites in German guidebooks are analysed. The results show that the selection of tourist sites is dependent on personal, editorial, geographical, economic and tourism-sociological factors. The production of information is dependent on a complex web of power relations, the core of which is constituted by authors, publishers and readers.In the second article, the content in German guidebooks on Sweden is analysed. Besides Stockholm and Northern Lapland, the regions presented most frequently are usually located in the south of the country. It is found that guidebooks influence German tourists’ choices of tourist sites in Sweden, and that this influence increases with the distance from Germany. The study also shows that guidebooks contribute to constructing tourism space and providing places with meaning.In the third article, it is shown that information and time availability influence tourist mobility. The existence of an individual travel rhythm is confirmed, which is defined as a travel pattern that is independent of the tourist sites that are visited. It includes, among other things, long travel distances the first and last days of the holiday, a short first stay-over, the longest stay in the region with the greatest distance from home, and a relation between the length of stay at one place and the distance covered when departing.In the last article, tourist behaviour is analysed. The results dispel the predominant impression in current tourism discourse that states that tourists are continually active during their holidays. It is found that the major difference between home and tourist behaviour is not constituted by the activities themselves, but by a difference in place, followed by a slower pace in which activities are performed and a limited time period. Spatial mobility, the characteristics of place and access to information all influence tourist behaviour on-site.In conclusion, it is found that tourist information, mobility and behaviour on the spot are closely connected. Tourists consume the tourism space created in guidebooks, and recreate this space when travelling, as they choose individually how to respond to the information provided. Actors, places and tourist structures all exist in relation to each other. For the resulting behaviour in place, this means that it is not only the supply at the destination that is important, but also the situation in tourists’ home regions and along their travel routes.
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