| 1. |
- Aronsson, Helena, et al.
(författare)
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Mellangrödor i växtföljden - för kolinlagring och effektivt kväveutnyttjande
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten beskriver mellangrödors funktion för kolinlagring i jordbruksmark i relation till andra funktioner och miljörisker. Den består av en kunskapsgenomgång, en inventering av data från fältförsök samt en sammanfattning av odlares erfarenheter vid en workshop. Vår definition av mellangröda är: En gröda som har sin huvudsakliga tillväxt mellan två huvudgrödor, och där syftet med att odla mellangrödan kan variera.Mellangrödan ger kolinlagring, särskilt rötternaKolinlagringen av en mellangröda har uppskattats till ca 320 kg kol i medeltal per ha och år, men variationen är stor. Vi sammanställde resultat från fältförsök med mellangrödor under 30 år. För insådda gräsfånggrödor skiljer sig biomassaproduktionen i medeltal inte så mycket åt mellan olika regioner, medan variationen är större för eftersådda mellangrödor. Det saknas kunskap för att kunna ge konkreta råd om hur artval och jordbearbetningsstrategier m.m. för mellangröda kan användas för att optimera stabiliseringsprocesserna för kol i marken. Mellangrödans rötter bidrar med ca 2,5 gånger större inlagring än den ovanjordiska grönmassan. Mätningar vi funnit visar en stor variation i viktförhållandet mellan skott och rot, som beror på arters variation, men också på osäkerheter i provtagning och metoder.Utmaningar för odlarnaBåde försök och odlares erfarenheter vittnar om utmaningar med sådd av mellangrödor efter skörd, särskilt på jordar med hög lerhalt. Det handlar om att hinna så direkt efter huvudgrödans skörd för att lyckas med etableringen och för att utnyttja hösten för tillväxt. Att ge sådd av mellangrödan lika hög prioritet som en huvudgröda var ett råd som erfarna odlare poängterade vid en workshop. Det finns olika tankesätt och strategier kring val av arter, beroende på syftet med mellangrödan. Genom artblandningar kan man också kombinera funktioner. Det finns inga tydliga råd för arter som särskilt främjar kolinlagring utan det viktigaste är stor tillväxt, hög kol-kväve-kvot (C/N-kvot), stor rotbiomassa samt baljväxtinslag. Hushållning med kvävet En nordisk sammanställning visade att mellangrödor i medeltal minskade kväveläckaget med drygt 40 %. Tidpunkt för nedbrukning eller kemisk avdödning är metoder för att styra återmineraliseringen och kväveverkan i nästa gröda. För frostkänsliga mellangrödor med låg C/N-kvot finns en risk att kvävet frigörs så snabbt att det hinner utlakas innan våren. Under sådana förhållanden ökar också risken för lustgasemissioner. Mer kunskap behövs om hur kväveomsättning påverkas och hur lustgasemissioner kan minimeras, för att kunna anpassa mellangrödesystemen efter olika odlingskrav och klimatets förändring.
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| 2. |
- Amato, Alberto, et al.
(författare)
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Grazer-induced transcriptomic and metabolomic response of the chain-forming diatom Skeletonema marinoi
- 2018
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Ingår i: ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 12, s. 1594-1604
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Tidskriftsartikel (refereegranskat)abstract
- Diatoms and copepods are main actors in marine food webs. The prey-predator interactions between them affect bloom dynamics, shape marine ecosystems and impact the energy transfer to higher trophic levels. Recently it has been demonstrated that the presence of grazers may affect the diatom prey beyond the direct effect of grazing. Here, we investigated the response of the chain-forming centric diatom Skeletonema marinoi to grazer cues, including changes in morphology, gene expression and metabolic profile. S. marinoi cells were incubated with Calanus finmarchicus or with Centropages typicus and in both cases responded by reducing the chain length, whereas changes in gene expression indicated an activation of stress response, changes in the lipid and nitrogen metabolism, in cell cycle regulation and in frustule formation. Transcripts linked to G protein-coupled receptors and to nitric oxide synthesis were differentially expressed suggesting involvement of these signalling transduction pathways in the response. Downregulation of a lipoxygenase in the transcriptomic data and of its products in the metabolomic data also indicate an involvement of oxylipins. Our data contribute to a better understanding of the gene function in diatoms, providing information on the nature of genes implicated in the interaction with grazers, a crucial process in marine ecosystems.
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| 3. |
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| 4. |
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Att välja trä
- 2020. - 10
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Samlingsverk (redaktörskap) (populärvet., debatt m.m.)
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| 5. |
- Beral, V, et al.
(författare)
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Alcohol, tobacco and breast cancer - collaborative reanalysis of individual data from 53 epidemiological studies, including 58515 women with breast cancer and 95067 women without the disease
- 2002
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 87, s. 1234-45
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Tidskriftsartikel (refereegranskat)abstract
- Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58515 women with invasive breast cancer and 95067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19 - 1.45, P < 0.00001) for an intake of 35 - 44 g per day alcohol, and 1.46 (1.33 - 1.61, P < 0.00001) for greater than or equal to 45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1 % per 10 g per day, P < 0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers= 1.03, 95% CI 0.98 - 1.07, and for current smokers=0.99, 0.92 - 1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver. (C) 2002 Cancer Research UK.
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| 6. |
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| 7. |
- Bergkvist, Jonas, et al.
(författare)
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Improved chip design for integrated solid-phase microextraction in on-line proteomic sample preparation
- 2002
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Ingår i: Proteomics. - 1615-9861. ; 2:4, s. 422-429
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Tidskriftsartikel (refereegranskat)abstract
- A recently introduced silicon microextraction chip (SMEC), used for on-line proteomic sample preparation, has proved to facilitate the process of protein identification by sample clean up and enrichment of peptides. It is demonstrated that a novel grid-SMEC design improves the operating characteristics for solid-phase microextraction, by reducing dispersion effects and thereby improving the sample preparation conditions. The structures investigated in this paper are treated both numerically and experimentally. The numerical approach is based on finite element analysis of the micro-fluidic flow in the microchip. The analysis is accomplished by use of the computational fluid dynamics-module FLOTRAN in the ANSYS(R) software package. The modeling and analysis of the previously reported weir-SMEC design indicates some severe drawbacks, that can be reduced by changing the microextraction chip geometry to the grid-SMEC design. The overall analytical performance was thereby improved and also verified by experimental work. Matrix-assisted laser desorption/ionization mass spectra of model peptides extracted from both the weir-SMEC and the new grid-SMEC support the numerical analysis results. Further use of numerical modeling and analysis of the SMEC structures is also discussed and suggested in this work.
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| 8. |
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| 9. |
- Bergkvist, Jonas, et al.
(författare)
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Miniaturized flowthrough microdispenser with piezoceramic tripod actuation
- 2005
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Ingår i: Journal of Microelectromechanical Systems. - 1057-7157. ; 14:1, s. 134-140
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the further development of a silicon flowthrough microdispenser is described. Previously reported designs of the dispenser used bimorph, and later multilayered, piezoelectric actuator elements for the generation of droplets. The introduction of a multilayered actuator significantly reduced the voltage amplitude needed to dispense droplets. Dispenser properties relevant for chemical analysis systems, e.g., reduced sample volume, internal surface area, and dispersion, were improved by miniaturization of the device. In this paper, a new actuator design, the tripod, is presented to enable further dispenser miniaturization and to facilitate device assembly. Tripod actuators were manufactured using a prototyping process, based on micromilling, for multilayer piezoceramic components. A building technique for miniaturized electrical interconnects, based on microstructured flexible printed circuits, is also suggested in line with the prospect of future miniaturization. The microfluidic properties of the tripod- actuated dispenser were evaluated. Stable droplet generation in the frequency range from 0 to 3 kHz was demonstrated, providing a maximum dispensed flow rate of 7.8 muL/min.
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| 10. |
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| 11. |
- Bergkvist, Magnus, et al.
(författare)
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Debridement, antibiotics and implant retention in early periprosthetic joint infection
- 2016
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Ingår i: HIP International. - : SAGE Publications. - 1120-7000 .- 1724-6067. ; 26:2, s. 138-143
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Periprosthetic joint infection (PJI) is a devastating complication in hip arthroplasty surgery. Debridement, antibiotics (AB) and implant retention (DAIR) is recommended in early PJI in association with stable implants. The aim of this study was to evaluate the success rate of DAIR in early PJI (<4 weeks) and to identify factors predicting the outcome. Methods: This cohort study included a consecutive series of 35 patients (median age 74 years, 25 women, 26 primary arthroplasties) treated with DAIR for an early PJI in a regional hospital. Results: 28 patients (80%) had their infection eradicated. DAIR-only eradicated the PJI in 22 (63%) patients with a median follow-up of 50 (24-84) months. In 17 (49%) patients, oral AB had been given prior to intraoperative cultures, which delayed first debridement with average 6 days and delayed hospital stay. Primary surgery for a hip fracture increased the risk of DAIR-failure. Surgical experience did not affect the outcome. 17% (n = 6) of the patients sustained a secondary infection during their hospital stay; the majority was beta-lactam resistant coagulase negative Staphylococcus aureus. Conclusions: The success rate of DAIR was inferior to pervious controls from experienced revision centers. Hip fracture patients should be informed about the increased risk of DAIR treatment failure. In order not to delay surgery, empirically based oral AB should not be administered prior to deep cultures.
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| 12. |
- Bergkvist, Sharon W, 1973, et al.
(författare)
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Improved iron solubility in carrot juice fermented by homo- and hetero-fermentative lactic acid bacteria
- 2005
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Ingår i: Food Microbiology. - : Elsevier BV. - 0740-0020 .- 1095-9998. ; 22:1, s. 53-61
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate lactic acid fermentation as a means to increase the availability of iron in carrot juice, two strains (Lactobacillus pentosus FSC1 and Leuconostoc mesenteroides FSC2), two types of carrot juice and two modes of fermentation were compared. Fermentation improved iron solubility up to 30 fold. The total mineral content and the yield of soluble iron differed between the two types of juice. Addition of pectolytic enzyme and cellulase further improved iron solubility in fermented juice by about 10%. L. pentosus FSC1 yielded the largest improvement in soluble iron, which was not simply a result of a decrease in pH. The concentration of soluble iron in Ln. mesenteroides FSC2 fermentation was linearly related to the major acids produced. Besides, the mineral inhibitor phytate was completely degraded in all the fermentations. Lactic acid fermentation strongly improves iron solubility in carrot juice. The level of improvement was strain specific and related to the produced acids rather than a simple pH effect. Composition of carrot juice and addition of viscosity-reducing enzymes also contributed to this improvement. Our study suggests that carrot juice with high mineral availability may be achieved by fermentation using selected starter cultures, substrate and process.
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| 13. |
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| 14. |
- Bergkvist, Sharon W, 1973, et al.
(författare)
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Lactic acid decreases Fe (II) and Fe (III) retention but increases Fe (III) transepithelial transfer by Caco-2 cells
- 2005
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 53:17, s. 6919-6923
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid (LA) has been proposed to be an enhancer for dietary iron absorption, but contradictory results have also been reported. In the present study, fully differentiated Caco-2 cell monolayers were used to evaluate the effects of LA (1-50 mmol/L) on the cellular retention and transepithelial transport of soluble non-heme iron (as ferric nitrilotriacetate). Our data revealed a linear decline in Fe(III) retention with respect to the concentration of LA added. In the presence of 50 mmol/L LA, retention of Fe(111) and Fe(II) decreased 57% and 58%, respectively. In contrast, transfer of Fe(111) across the cell monolayer was doubled, while Fe(II) transfer across the cell monolayer decreased 35%. We conclude that LA reduces cellular retention and transepithelial transport of Fe(l I) by Caco-2 cells in a dose-dependent manner. However, while LA also reduces retention of Fe(111) by Caco-2 cells, the transfer of Fe(III) across cell monolayers is enhanced, possibly due to effects on paracellular transport.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Dahlberg, Leif, et al.
(författare)
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Starkt samband övervikt/obesitas och ortopediska åkommor. Fetmaepidemins konsekvenser vidgas.
- 2008
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Ingår i: Läkartidningen. - 0023-7205. ; 105:34, s. 2246-2248
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Tidskriftsartikel (refereegranskat)abstract
- t is well known that overweight/obesity are risk factors for several important conditions of internal medicine. The positive correlation between gonarthrosis and a high BMI is also well investigated. However, the possible correlation between owerweight/obesitas and other orthopaedic conditions are less well studied and are therefore rarely discussed in either medical terms or economical considerations. Objective: To examine the relationship between owerweight/obesity and orthopaedic conditions. Patient BMI was compared with a reference population BMI in two assessments. In one we investigated patients who were diagnosed with ankle fracture in the emergency room (n=79). In the other we investigated outpatients with various orthopaedic conditions (n=647). In both assessments patients were recruited in a consecutive mode. The BMI of the patients with ankle fracture was self reported as were the BMI of the normal population. The outpatients were weighted and measured. Patients with ankle fractures differed significantly from the reference population, (1.92 units (p<0.001). The fracture odds ratio of BMI>30 was 3.46 (p<0.001). Similarly, the outpatients had 1.44 higher BMI units than the references (p<0,001). Odds ratio to become an orthopaedic outpatient if BMI>30 was 2.3 (p<0.001). In both investigations results were age and gender standardised. Both studies indicate that there is a positive correlation between BMI and the risk of sustaining orthopaedic conditions. Although there may be reporting-bias, results seem prominent enough to conclude that orthopaedic conditions may be added to other medical disciplines regarding negative consequences of overweight/obesity and strengthens the need for preventive measures aimed at the epidemic progress of overweight/obesity.
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| 19. |
- Forsberg, Samuel
(författare)
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Power Grid Resilience to High Impact Low Probability Events
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The electrification of societies and the decarbonisation of electricity production are changing energy systems worldwide. A fast transition towards the replacement of fossil fuels by intermittent renewable energy sources is expected in the next decades to combat climate change. A significant share of the produced electricity is likely to be generated from offshore wind farms, due to the abundant wind resources in the offshore regions and the lack of available onshore sites. However, increased electricity dependence in combination with expanded offshore wind power generation introduce new vulnerabilities to the society. Specifically, the effects of high impact low probability (HILP) events are considered as potential threats to the power system, not least because of the increasing number of extreme weather events. Therefore, research on power grid vulnerability and power system resilience to HILP events are of significant interest.This thesis presents results of studies investigating power grid vulnerability from a topological perspective, and resilience to storm conditions of power systems with varying dependencies on offshore wind. To achieve this, methods based on complex network theory and AC power flow analysis have been developed, tested, and evaluated. Further, geospatial wind data from historical extreme storm events have been used to generate realistic power production profiles from hypothetical offshore wind farms.The results strengthen that complex network concepts can be used successfully in the context of power grid vulnerability analysis. Further, the results show that the resilience of power systems with large dependencies on offshore wind differ vastly depending on the grid properties and control strategies, which are further discussed in this thesis.
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| 20. |
- Forsberg, Samuel, et al.
(författare)
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Power grid vulnerability analysis using complex network theory : A topological study of the Nordic transmission grid
- 2023
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Ingår i: Physica A. - : Elsevier. - 0378-4371 .- 1873-2119. ; 626
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Tidskriftsartikel (refereegranskat)abstract
- To reduce the vulnerability of power grids to high impact low probability (HILP) events, analysis methods can be applied to quantify the criticality of the nodes in the grid. The method implemented in this article is one originating from complex network theory. It is used to quantify the structural vulnerability of an open-source transmission grid model representing the Nordic transmission grid. The analytical measures used are clustering coefficient and betweenness, closeness, degree, and combined centrality, which are weighted with respect to the estimated values of the transmission lines’ series reactance. The results, which are presented in the form of geographic and network representations, show substantial differences in terms of criticality between the nodes. The most critical ones are highlighted in geographic representations and are further compared with an open-source system analysis performed by the Swedish transmission system operator (TSO). The outcome from this study is that the weighted and combined centrality measure performed the best in terms of identifying critical nodes in the Nordic transmission grid. Thus, the method can be used as a tool for assessing the structural vulnerability of a real transmission grid, even with limited access to electrical grid data. However, the results from this method should not be considered conclusive.
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| 21. |
- Forsberg, Samuel, et al.
(författare)
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Resilience to extreme storm conditions : A comparative study of two power systems with varying dependencies on offshore wind
- 2024
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Ingår i: Results in Engineering (RINENG). - : Elsevier. - 2590-1230. ; 23
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Tidskriftsartikel (refereegranskat)abstract
- In the next decades, the dependencies on power production from renewable energy sources are expected to increase dramatically. A transition towards large-scale offshore wind farms together with an increased electrification of the industry and transportation sectors introduces new vulnerabilities to society. Further, extreme weather events are expected to increase in intensity and frequency, driven by climate change. However, there are significant knowledge gaps concerning the impacts of severe weather conditions on the resilience of power systems with large dependencies on offshore wind. In the present study, a comparison between two different power systems’ resilience to historical extreme storm conditions has been conducted. The power systems are the IEEE39-bus New England model and the Great Britain model. The results show significant differences between the two power systems, which underlying reasons are analysed and explained. With an offshore wind penetration level of 30 %, the New England model stays intact in terms of connected load. When increasing the penetration level to 40 %, about 10 % of the total connected load gets disconnected, whereas about 33 % of the load gets disconnected with a penetration level of 50 %. The Great Britain model stays intact in terms of connected load with a penetration level of at least 49 %.
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| 22. |
- Forsberg, Samuel, et al.
(författare)
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Resilience to storm conditions of power systems with large dependencies on offshore wind
- 2023
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Ingår i: Journal of Physics, Conference Series. - : Institute of Physics Publishing (IOPP). - 1742-6588 .- 1742-6596. ; 2626
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Tidskriftsartikel (refereegranskat)abstract
- The ongoing transition towards large installations of offshore wind and the electrification of the transport sector and other critical infrastructures introduce new vulnerabilities to the society. Large dependencies of power production from offshore wind are expected in the next decades, but there are large knowledge gaps regarding the power production reliability under severe weather conditions. Simultaneously, weather extremes may increase in frequency and intensity, driven by climate change. In this paper we investigate the resilience of a power system subject to a hurricane event. The power system is based on the IEEE39-bus New England system but with different scenarios for increasing penetration of offshore wind. We find that an offshore wind penetration level of 30% or less results in a power system resilient to hurricane events, with no need for load disconnection. However, when increased to 40% offshore wind penetration, 650 MW corresponding to 10% of the total load demand gets disconnected during the storm peak. With a penetration of 50% offshore wind, the disconnected load ranges from 2.2 GW of load corresponding to 1/3 of the total load demand, to a total power system blackout.
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| 23. |
- Genkinger, Jeanine M., et al.
(författare)
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Alcohol Intake and Pancreatic Cancer Risk : A Pooled Analysis of Fourteen Cohort Studies
- 2009
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 18:3, s. 765-776
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Forskningsöversikt (refereegranskat)abstract
- Background: Few risk factors have been implicated in pancreatic cancer etiology. Alcohol has been theorized to promote carcinogenesis. However, epidemiologic studies have reported inconsistent results relating alcohol intake to pancreatic cancer risk. Methods: We conducted a pooled analysis of the primary data from 14 prospective cohort studies. The study sample consisted of 862,664 individuals among whom 2,187 incident pancreatic cancer cases were identified. Study-specific relative risks and 95% confidence intervals were calculated using Cox proportional hazards models and then pooled using a random effects model. Results: A slight positive association with pancreatic cancer risk was observed for alcohol intake (pooled multivariate relative risk, 1.22; 95% confidence interval, 1.03-1.45 comparing >= 30 to 0 grams/day of alcohol; P value, test for between-studies heterogeneity = 0.80). For this comparison, the positive association was only statistically significant among women although the difference in the results by gender was not statistically significant (P value, test for interaction = 0.19). Slightly stronger results for alcohol intake were observed when we limited the analysis to cases with adenocarcinomas of the pancreas. No statistically significant associations were observed for alcohol from wine, beer, and spirits comparing intakes of >= 5 to 0 grams/day. A stronger positive association between alcohol consumption and pancreatic cancer risk was observed among normal weight individuals compared with overweight and obese individuals (P value, test for interaction = 0.01). Discussion: Our findings are consistent with a modest increase in risk of pancreatic cancer with consumption of 30 or more grams of alcohol per day. (Cancer Epidemiol Biomarkers Prev 2009;18(3):765-76)
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| 24. |
- Genkinger, Jeanine M., et al.
(författare)
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Coffee, Tea, and Sugar-Sweetened Carbonated Soft Drink Intake and Pancreatic Cancer Risk : A Pooled Analysis of 14 Cohort Studies
- 2012
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 21:2, s. 305-318
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Tidskriftsartikel (refereegranskat)abstract
- Background: Coffee has been hypothesized to have pro- and anticarcinogenic properties, whereas tea may contain anticarcinogenic compounds. Studies assessing coffee intake and pancreatic cancer risk have yielded mixed results, whereas findings for tea intake have mostly been null. Sugar-sweetened carbonated soft drink (SSB) intake has been associated with higher circulating levels of insulin, which may promote carcinogenesis. Few prospective studies have examined SSB intake and pancreatic cancer risk; results have been heterogeneous. Methods: In this pooled analysis from 14 prospective cohort studies, 2,185 incident pancreatic cancer cases were identified among 853,894 individuals during follow-up. Multivariate (MV) study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and then pooled using a random-effects model. Results: No statistically significant associations were observed between pancreatic cancer risk and intake of coffee (MVRR = 1.10; 95% CI, 0.81-1.48 comparing >= 900 to <0 g/d; 237g approximate to 8oz), tea (MVRR = 0.96; 95% CI, 0.78-1.16 comparing >= 400 to 0 g/d; 237g approximate to 8oz), or SSB (MVRR = 1.19; 95% CI, 0.98-1.46 comparing >= 250 to 0 g/d; 355g approximate to 12oz; P value, test for between-studies heterogeneity > 0.05). These associations were consistent across levels of sex, smoking status, and body mass index. When modeled as a continuous variable, a positive association was evident for SSB (MVRR = 1.06; 95% CI, 1.02-1.12). Conclusion and Impact: Overall, no associations were observed for intakes of coffee or tea during adulthood and pancreatic cancer risk. Although we were only able to examine modest intake of SSB, there was a suggestive, modest positive association for risk of pancreatic cancer for intakes of SSB.
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| 25. |
- Hellsten, Torbjörn A. K., et al.
(författare)
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On ion cyclotron emission in toroidal plasmas
- 2006
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Ingår i: Nuclear Fusion. - 0029-5515 .- 1741-4326. ; 46:7, s. S442-S454
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Tidskriftsartikel (refereegranskat)abstract
- A detailed study of ion cyclotron interactions in a toroidal plasma has been carried out in order to elucidate the role of toroidal effects on ion cyclotron emission. It is well known that non-relaxed distribution functions can give rise to excitation of magnetosonic waves by ion cyclotron interactions when the distribution function increases with respect to the perpendicular velocity. We have extended and clarified the conditions under which even collisionally relaxed distribution function can destabilize magnetosonic eigenmodes. In a toroidal plasma, cyclotron interactions at the plasma boundary with ions having barely co-current passing orbits and marginally trapped orbits can cause destabilisation by the strong inversion of the distribution function along the characteristics of cyclotron interaction by neo-classical effects. The unstable interactions can further be enhanced by tangential interactions, which can also prevent the interactions from reaching the stable part of the characteristics, where they interact with trapped orbits. Conditions on the localization of the magnetosonic eigenmodes for unstable excitation are analysed by studying the anti-Hermitian part of the susceptibility tensor of thermonuclear alpha-particles. The pattern of positive and negative regions of the anti-Hermitian part of the susceptibility tensor of thermonuclear alpha-particles is, in general, consistent with the excitation of edge localized magnetosonic eigenmodes, even though the eigenmodes are usually not localized in the major radius and for distribution functions that have relaxed to steady state.
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