| 1. |
- Björklund, J., et al.
(author)
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Scientific Merits and Analytical Challenges of Tree-Ring Densitometry
- 2019
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In: Reviews of geophysics. - 8755-1209 .- 1944-9208. ; 57:4, s. 1224-1264
-
Research review (peer-reviewed)abstract
- X-ray microdensitometry on annually resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density (MXD) parameter, but also increasingly through other density parameters. For 50 years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular, and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh long-standing wisdom but also provide new insights. Key outcomes include (i) a demonstration of the need for mass/volume-based recalibration to accurately estimate average ring density; (ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density data sets for climate reconstructions; and (iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate futureinter-comparability and interpretations for global change research.
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| 2. |
- Björklund, Jesper, 1979, et al.
(author)
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Scientific Merits and Analytical Challenges ofTree-Ring Densitometry
- 2019
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In: Reviews of Geophysics. - : American Geophysical Union (AGU). - 8755-1209 .- 1944-9208. ; 57:4, s. 1224-1264
-
Journal article (peer-reviewed)abstract
- X-ray microdensitometry on annually resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density (MXD) parameter, but also increasingly through other density parameters. For 50 years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular, and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh "long-standing wisdom" but also provide new insights. Key outcomes include (i) a demonstration of the need for mass/volume-based recalibration to accurately estimate average ring density; (ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density data sets for climate reconstructions; and (iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate futureinter-comparability and interpretations for global change research.
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| 3. |
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| 4. |
- Hansen, T. W., et al.
(author)
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Ambulatory blood pressure monitoring for risk stratification in obese and non-obese subjects from 10 populations
- 2014
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In: Journal of Human Hypertension. - : Springer Science and Business Media LLC. - 0950-9240 .- 1476-5527. ; 28:9, s. 535-542
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Journal article (peer-reviewed)abstract
- Overweight clusters with high blood pressure (BP), but the independent contribution of both risk factors remains insufficiently documented. In a prospective population study involving 8467 participants (mean age 54.6 years; 47.0% women) randomly recruited from 10 populations, we studied the contribution of body mass index (BMI) to risk over and beyond BP, taking advantage of the superiority of ambulatory over conventional BP. Over 10.6 years (median), 1271 participants (15.0%) died and 1092 (12.9%), 637 (7.5%) and 443 (5.2%) experienced a fatal or nonfatal cardiovascular, cardiac or cerebrovascular event. Adjusted for sex and age, low BMI (<20.7 kg m(-2)) predicted death (hazard ratio (HR) vs average risk, 1.52; P<0.0001) and high BMI (>= 30.9 kg m(-2)) predicted the cardiovascular end point (HR, 1.27; P = 0.006). With adjustments including 24-h systolic BP, these HRs were 1.50 (P <0.001) and 0.98 (P = 0.91), respectively. Across quartiles of the BMI distribution, 24-h and nighttime systolic BP predicted every end point (1.13 <= standardized HR <= 1.67; 0.046 <= P<0.0001). The interaction between systolic BP and BMI was nonsignificant (P >= 0.22). Excluding smokers removed the contribution of BMI categories to the prediction of mortality. In conclusion, BMI only adds to BP in risk stratification for mortality but not for cardiovascular outcomes. Smoking probably explains the association between increased mortality and low BMI.
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| 5. |
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| 6. |
- Babst, F., et al.
(author)
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When tree rings go global: Challenges and opportunities for retro- and prospective insight
- 2018
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In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 197, s. 1-20
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Journal article (peer-reviewed)abstract
- The demand for large-scale and long-term information on tree growth is increasing rapidly as environmental change research strives to quantify and forecast the impacts of continued warming on forest ecosystems. This demand, combined with the now quasi-global availability of tree-ring observations, has inspired researchers to compile large tree-ring networks to address continental or even global-scale research questions. However, these emergent spatial objectives contrast with paleo-oriented research ideas that have guided the development of many existing records. A series of challenges related to how, where, and when samples have been collected is complicating the transition of tree rings from a local to a global resource on the question of tree growth. Herein, we review possibilities to scale tree-ring data (A) from the sample to the whole tree, (B) from the tree to the site, and (C) from the site to larger spatial domains. Representative tree-ring sampling supported by creative statistical approaches is thereby key to robustly capture the heterogeneity of climate-growth responses across forested landscapes. We highlight the benefits of combining the temporal information embedded in tree rings with the spatial information offered by forest inventories and earth observations to quantify tree growth and its drivers. In addition, we show how the continued development of mechanistic tree-ring models can help address some of the non-linearities and feedbacks that complicate making inference from tree-ring data. By embracing scaling issues, the discipline of dendrochronology will greatly increase its contributions to assessing climate impacts on forests and support the development of adaptation strategies. © 2018 Elsevier Ltd
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| 7. |
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| 8. |
- Dickson, L. T., et al.
(author)
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Mechanisms to control laser-plasma coupling in laser wakefield electron acceleration
- 2022
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In: Physical Review Accelerators and Beams. - 2469-9888. ; 25:10
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Journal article (peer-reviewed)abstract
- Experimental results, supported by precise modeling, demonstrate optimization of a plasma-based injector with intermediate laser pulse energy (<1 J), corresponding to a normalized vector potential a0=2.15, using ionization injection in a tailored plasma density profile. An increase in electron bunch quality and energy is achieved experimentally with the extension of the density downramp at the plasma exit. Optimization of the focal position of the laser pulse in the tailored plasma density profile is shown to efficiently reduce electron bunch angular deviation, leading to a better alignment of the electron bunch with the laser axis. Single peak electron spectra are produced in a previously unexplored regime by combining an early focal position and adaptive optic control of the laser wavefront by optimizing the symmetry of the prefocal laser energy distribution. Experimental results have been validated through particle-in-cell simulations using realistic laser energy, phase distribution, and temporal envelope, allowing for accurate predictions of difficult to model parameters, such as total charge and spatial properties of the electron bunches, opening the way for more accurate modeling for the design of plasma-based accelerators.
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| 9. |
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| 10. |
- Unger, M. M., et al.
(author)
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Unimpaired postprandial pancreatic polypeptide secretion in Parkinson's disease and REM sleep behavior disorder
- 2013
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In: Movement Disorders. - : Wiley. - 0885-3185. ; 28:4, s. 529-533
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Journal article (peer-reviewed)abstract
- Background: Pancreatic polypeptide is released immediately after food ingestion. The release is operated by vagal-abdominal projections and has therefore been suggested as a test for vagal nerve integrity. Pathoanatomical and clinical studies indicate vagal dysfunction in early Parkinson's disease (PD). Methods: We assessed the postprandial secretion of pancreatic polypeptide and motilin in healthy controls (n = 18) and patients with idiopathic rapid-eye-movement sleep behavior disorder (iRBD, n = 10), a potential premotor stage of PD, as well as in drug-naive (n = 19) and treated (n = 19) PD patients. Results: The postprandial pancreatic polypeptide secretion showed a physiological pattern in all groups and even an enhanced response in drug-naive PD and iRBD. Motilin concentrations correlated with pancreatic polypeptide concentrations. Conclusions: Postprandial pancreatic polypeptide secretion is not a suitable test for vagal nerve integrity in PD. The unimpaired pancreatic polypeptide response in iRBD and PD might be explained by partially intact vagal-abdominal projections or compensatory mechanisms substituting a defective neuronal brain–gut axis.
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| 11. |
- Widner, H, et al.
(author)
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Bilateral fetal mesencephalic grafting in two patients with parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)
- 1992
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In: New England Journal of Medicine. - 0028-4793. ; 327:22, s. 63-1556
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Journal article (peer-reviewed)abstract
- BACKGROUND: Intracerebral transplantation of fetal dopaminergic neurons is a promising new approach for the treatment of Parkinson's disease. Patients with parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) have a relatively stable lesion limited to the nigrostriatal system, rendering them ideal candidates for transplantation. Improvement of motor function after neural grafting has previously been observed in nonhuman primates with MPTP-induced parkinsonism.METHODS: We grafted human fetal tissue from the ventral mesencephalon (obtained six to eight weeks after conception) bilaterally to the caudate and putamen in two immunosuppressed patients with severe MPTP-induced parkinsonism, using a stereotaxic technique. The patients were assessed regularly with clinical rating scales, timed tests of motor performance, and [18F]fluorodopa positron-emission tomography during the 18 months before the operation and the 22 to 24 months after the operation.RESULTS: Both patients had substantial, sustained improvement in motor function and became much more independent. Postoperatively, the second patient's maintenance dose of levodopa was decreased to 150 mg daily, which was 30 percent of the original dose. Striatal uptake of fluorodopa was unchanged 5 to 6 months postoperatively but was markedly and bilaterally increased at 12 to 13 and 22 to 24 months in both patients, closely paralleling the patients' clinical improvement. There were no serious complications.CONCLUSIONS: Bilateral implantation of fetal mesencephalic tissue can induce substantial long-term functional improvement in patients with parkinsonism and severe dopamine depletion and is accompanied by increased uptake of fluorodopa by the striatum. The results in these patients resemble those obtained in MPTP-treated primates and suggest that this will be a useful model for the assessment of transplantation therapies in Parkinson's disease.
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| 12. |
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| 13. |
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| 14. |
- Bechshoft, Thea, et al.
(author)
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Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
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In: Conservation Physiology. - 2051-1434. ; 3
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Journal article (peer-reviewed)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
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| 15. |
- Bechshoft, Thea, et al.
(author)
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Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
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In: Conservation Physiology. - : Oxford University Press. - 2051-1434. ; 3
-
Journal article (peer-reviewed)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
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| 16. |
- Björklund, Emmelie, et al.
(author)
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Inhibition of monoacylglycerol lipase by troglitazone, N-arachidonoyl dopamine and the irreversible inhibitor JZL184 : comparison of two different assays
- 2010
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In: British Journal of Pharmacology. - : Wiley. - 0007-1188 .- 1476-5381. ; 161:7, s. 1512-1526
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: Drugs used clinically usually have a primary mechanism of action, but additional effects on other biological targets can contribute to their effects. A potentially useful additional target is the endocannabinoid metabolizing enzyme monoacylglycerol lipase (MGL). We have screened a range of drugs for inhibition of MGL and compared the observed potencies using different MGL enzyme assays.EXPERIMENTAL APPROACH: MGL activity was screened using recombinant human MGL (cell lysates and purified enzyme) with 4-nitrophenyl acetate (NPA) as substrate. 2-Oleolyglycerol metabolism by rat cerebellar cytosolic MGL and by recombinant MGL was also investigated.KEY RESULTS: Among the 96 compounds screened in the NPA assay, troglitazone, CP55,940, N-arachidonoyl dopamine and AM404 inhibited NPA hydrolysis by the lysates with IC(50) values of 1.1, 4.9, 0.78 and 3.1µM, respectively. The potency for troglitazone is in the same range as its primary pharmacological activity, activation of peroxisome proliferator-activated receptor (PPAR) γ. Among PPARγ ligands, the potency order towards human MGL was troglitazone > ciglitazone > rosiglitazone > 15-deoxy-Δ(12,14) -prostaglandin J(2) ≈ CAY 10415 > CAY 10514. In contrast to the time-dependent inhibitor JZL184, the potency of troglitazone was dependent upon the enzyme assay system used. Thus, troglitazone inhibited rat cytosolic 2-oleoylglycerol hydrolysis less potently (IC(50) 41µM) than hydrolysis of NPA by the human MGL lysates.CONCLUSIONS AND IMPLICATIONS: 'Hits' in screening programmes for MGL inhibitors should be assessed in different MGL assays. Troglitazone may be a useful lead for the design of novel, dual action MGL inhibitors/PPARγ activators.
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| 17. |
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| 18. |
- Björklund Svensson, J., et al.
(author)
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Start-to-end simulations of plasma-wakefield acceleration using the MAX IV Linear Accelerator
- 2022
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In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1033
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Journal article (peer-reviewed)abstract
- Plasma-wakefield acceleration (PWFA) relies on the interaction between intense particle bunches and plasma for reaching higher accelerating gradients than what is possible with conventional radio-frequency technology. Using ultra-relativistic beam drivers allows for long acceleration lengths and have potential applications such as energy booster stages for synchrotron light sources or linear colliders and generating ultra-high-brightness beams from the background plasma. In this article, we present start-to-end simulations of the MAX IV Linear Accelerator as part of our investigations into the feasibility of using the linac for a PWFA experiment. We find that PWFA appears to be a viable application for the linac. A part of this conclusion is based on our finding that the general properties of the bunch compressor type employed in the MAX IV linac are well-suited for efficient generation of PWFA-optimized bunch current profiles, both for single- and double-bunch beams.
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| 19. |
- Choquet, Isabelle, 1965-, et al.
(author)
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New powder port holder geometry to avoid lump formation in APS
- 2005
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In: 17th international symposium on plasma chemistry (ISPC 17). ; , s. OP7. 1-6
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Conference paper (other academic/artistic)abstract
- A new geometry of the powder port ring holder used in atmospheric plasma spraying has recently been designed to avoid lump formation, and successfully tested for a set of process parameters associated with Ni-5Al powder used in production to form bond coat [1]. But with ZrO 2 powder used to made top coat, improvements were not enough satisfactory. Here, we investigate numerically the cause of the remaining defects, and further improve the ring geometry to prevent lump from forming in any part of the coating.
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| 20. |
- Cisneros, Jose A., et al.
(author)
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Structure-Activity Relationship of a New Series of Reversible Dual Monoacylglycerol Lipase/Fatty Acid Amide Hydrolase Inhibitors
- 2012
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In: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:2, s. 824-836
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Journal article (peer-reviewed)abstract
- The two endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), play independent and nonredundant roles in the body. This makes the development of both selective and dual inhibitors of their inactivation an important priority. In this work we report a new series of inhibitors of monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH). Among them, (+/-)-oxiran-2-ylmethyl 6-(1,1'-biphenyl-4-yl)hexanoate (8) and (2R)-(-)-oxiran-2-ylmethyl(4-benzylphenyl)acetate (30) stand out as potent inhibitors of human recombinant MAGL (IC(50) (8) = 4.1 mu M; IC(50) (30) = 2.4 mu M), rat brain monoacylglycerol hydrolysis (IC(50) (8) = 1.8 mu M; IC(50) (30) = 0.68 mu M), and rat brain FAAH (IC(50) (8) = 5.1 mu M; IC(50) (30) = 0.29 mu M). Importantly, and in contrast to the other previously described MAGL inhibitors, these compounds behave as reversible inhibitors either of competitive (8) or noncompetitive nature (30). Hence, they could be useful to explore the therapeutic potential of reversible MAGL inhibitors.
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| 21. |
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| 22. |
- Eriksson, Ola, et al.
(author)
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Municipal Solid Waste Management from a Systems Perspective
- 2005
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 13:3, s. 241-252
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Journal article (peer-reviewed)abstract
- Different waste treatment options for municipal solid waste have been studied in a systems analysis. Different combinations of incineration, materials recycling of separated plastic and cardboard containers, and biological treatment (anaerobic digestion and composting) of biodegradable waste, were studied and compared to landfilling. The evaluation covered use of energy resources, environmental impact and financial and environmental costs. In the study, a calculation model ( ) based on methodology from life cycle assessment (LCA) was used. Case studies were performed in three Swedish municipalities: Uppsala, Stockholm, and Älvdalen. The study shows that reduced landfilling in favour of increased recycling of energy and materials lead to lower environmental impact, lower consumption of energy resources, and lower economic costs. Landfilling of energy-rich waste should be avoided as far as possible, partly because of the negative environmental impacts from landfilling, but mainly because of the low recovery of resources when landfilling. Differences between materials recycling, nutrient recycling and incineration are small but in general recycling of plastic is somewhat better than incineration and biological treatment somewhat worse. When planning waste management, it is important to know that the choice of waste treatment method affects processes outside the waste management system, such as generation of district heating, electricity, vehicle fuel, plastic, cardboard, and fertiliser.
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| 23. |
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| 24. |
- Hagell, Peter, et al.
(author)
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Sequential bilateral transplantation in Parkinson's disease: effects of the second graft
- 1999
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In: Brain. - : Oxford University Press (OUP). - 1460-2156. ; 122:6, s. 1121-1132
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Journal article (peer-reviewed)abstract
- Five parkinsonian patients who had received implants of human embryonic mesencephalic tissue unilaterally in the striatum 10-56 months earlier were grafted with tissue from four to eight donors into the putamen (four patients) or the putamen plus the caudate nucleus (one patient) on the other side, and were followed for 18-24 months. After 12-18 months, PET showed a mean 85% increase in 6-L-[18F]fluorodopa uptake in the putamen with the second graft, whereas there was no significant further change in the previously transplanted putamen. Two patients exhibited marked additional improvements after their second graft: 'on-off' fluctuations virtually disappeared, movement speed increased, and L-dopa could be withdrawn in one patient and reduced by 70% in the other. The improvement in one patient was moderate. Two patients with atypical features, who responded poorly to the first graft, worsened following the second transplantation. These findings indicate that sequential transplantation in patients does not compromise the survival and function of either the first or the second graft. Moreover, putamen grafts that restore fluorodopa uptake to normal levels can give improvements of major therapeutic value.
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| 25. |
- Kotur, M, et al.
(author)
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PHOTOCATHODE LASER PULSE SHAPING FOR IMPROVED EMITTANCE
- 2018
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In: Proceedings of the 29th Linear Accelerator Conference, LINAC 2018. - 9783954501946 ; , s. 84-86
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Conference paper (peer-reviewed)abstract
- We present a setup for producing and characterizing picosecond ultraviolet laser pulses for use in the MAX IV photocathode electron gun preinjector. Frequency-tripled laser pulses from a commercial laser system are shaped directly in the ultraviolet domain using a Fourier-domain pulse shaper. The pulses were characterized using a transient grating FROG. We discuss a proposed upgrade of the pulse shaper, as well as its limitations.
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