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| 3. |
- 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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| 5. |
- Söderström, Lisa, 1982-
(författare)
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Nutritional status among older people : Risk factors and consequences of malnutrition
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Despite the high frequency and serious consequences of protein–energy malnutrition, prevention and treatment of malnutrition do not currently receive appropriate attention. Increased awareness of the importance of nutritional screening among older people is needed. The overall aim of this thesis was to extend our current knowledge about malnutrition and the consequences of a poor nutritional status in relation to preterm death, and to identify possible risk factors for developing malnutrition among older people. The aim of Paper I was to estimate the prevalence of malnutrition and to examine the associations between mealtime habits, meal provision, and malnutrition among older people admitted to a Swedish hospital. The aim of Paper II was to examine whether nutritional status, defined according to the three categories in the full Mini Nutritional Assessment (MNA) instrument, is an independent predictor of preterm death in older people.The baseline survey was a cross-sectional study of 1771 patients aged ³65 years who were admitted to hospital. Nutritional status was assessed using the MNA instrument, and possible risk factors associated with malnutrition were recorded during the hospital stay (Paper I). Overall survival was followed up after 35–50 months in a cohort study of 1767 participants (Paper II).Of the 1771 participants, 35.5% were well-nourished, 55.1% were at risk of malnutrition, and 9.4% were malnourished at baseline. An overnight fast >11 hours was associated with risk of malnutrition (odds ratio (OR) 1.46; 95% confidence interval (CI) 1.14–1.87) and being malnourished (OR 1.67; 95% CI 1.04–2.69). Fewer than four eating episodes a day was associated with both risk of malnutrition (OR 1.88, 95% CI 1.52–2.32) and being malnourished (OR 3.10; 95% CI 2.14–4.49). Not cooking independently was also associated with both risk of malnutrition (OR 1.9; 95% CI 1.30–2.93) and being malnourished (OR 5.04; 95% CI 2.95–8.61). At the 50-month follow-up, the survival rates were 75.2% for well-nourished participants, 60.0% for those at risk of malnutrition, and 33.7% for malnourished participants. After adjusting for confounders, the hazard ratios (95% CI) for all-cause mortality were 1.56 (1.18–2.07) in the group at risk of malnutrition and 3.71 (2.28–6.04) in the malnourished group. Nutritional status defined according to the three categories in the full MNA independently predicted preterm death in people aged 65 years and older.This thesis provides additional knowledge of the current nutritional situation among older people admitted to hospital. The high prevalence and serious consequences of malnutrition demonstrated in this thesis underline the importance of screening and taking actions to counteract malnutrition among older people. The data showing that the length of overnight fasting and number of eating episodes per day are possible risk factors for malnutrition are consistent with the current nutritional recommendations. This knowledge may stimulate care providers to decrease the length of overnight fasting and increase the number of eating episodes per day among older people at risk of malnutrition.
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| 7. |
- de Boniface, J., et al.
(författare)
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Omitting axillary dissection in breast cancer with sentinel-node metastases
- 2024
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 390:13, s. 1163-1175
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Trials evaluating the omission of completion axillary-lymph-node dissection in patients with clinically node-negative breast cancer and sentinel-lymph-node metastases have been compromised by limited statistical power, uncertain nodal radiotherapy target volumes, and a scarcity of data on relevant clinical subgroups.METHODS We conducted a noninferiority trial in which patients with clinically node-negative primary T1 to T3 breast cancer (tumor size, T1, ≤20 mm; T2, 21 to 50 mm; and T3, >50 mm in the largest dimension) with one or two sentinel-node macrometastases (metastasis size, >2 mm in the largest dimension) were randomly assigned in a 1:1 ratio to completion axillary-lymph-node dissection or its omission (sentinel-node biopsy only). Adjuvant treatment and radiation therapy were used in accordance with national guidelines. The primary end point was overall survival. We report here the per-protocol and modified intention-to-treat analyses of the prespecified secondary end point of recurrence-free survival. To show noninferiority of sentinel-node biopsy only, the upper boundary of the confidence interval for the hazard ratio for recurrence or death had to be below 1.44.RESULTS Between January 2015 and December 2021, a total of 2766 patients were enrolled across five countries. The per-protocol population included 2540 patients, of whom 1335 were assigned to undergo sentinel-node biopsy only and 1205 to undergo completion axillary-lymph-node dissection (dissection group). Radiation therapy including nodal target volumes was administered to 1192 of 1326 patients (89.9%) in the sentinel-node biopsy–only group and to 1058 of 1197 (88.4%) in the dissection group. The median follow-up was 46.8 months (range, 1.5 to 94.5). Overall, 191 patients had recurrence or died. The estimated 5-year recurrence-free survival was 89.7% (95% confidence interval [CI], 87.5 to 91.9) in the sentinel-node biopsy–only group and 88.7% (95% CI, 86.3 to 91.1) in the dissection group, with a country-adjusted hazard ratio for recurrence or death of 0.89 (95% CI, 0.66 to 1.19), which was significantly (P<0.001) below the prespecified noninferiority margin.CONCLUSIONS The omission of completion axillary-lymph-node dissection was noninferior to the more extensive surgery in patients with clinically node-negative breast cancer who had sentinel-node macrometastases, most of whom received nodal radiation therapy. (Funded by the Swedish Research Council and others; SENOMAC ClinicalTrials.gov number, NCT02240472.).
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| 8. |
- Hellsten, Torbjörn, et al.
(författare)
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Fast wave current drive in JET ITB-plasma
- 2005
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Ingår i: AIP Conference Proceedings. - : AIP. - 0094-243X. ; , s. 273-278
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Konferensbidrag (refereegranskat)abstract
- Fast wave current drive has been performed in JET plasmas with internal transport barriers, ITBs, and strongly reversed magnetic shear. Although the current drive efficiency of the power absorbed on the electrons is fairly high, only small effects are seen in the central current density. The main reasons are the parasitic absorption of RF power, the strongly inductive nature of the plasma and the interplay between the fast wave driven current and bootstrap current. The direct electron heating in the FWCD experiments is found to be strongly degraded compared to that with the dipole phasing.
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| 9. |
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| 14. |
- Cluver, Catherine, et al.
(författare)
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Impact of fetal growth restriction on pregnancy outcome in women undergoing expectant management for preterm pre-eclampsia
- 2023
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Ingår i: Ultrasound in Obstetrics and Gynecology. - 1469-0705 .- 0960-7692. ; 62:5, s. 660-667
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To assess whether coexisting fetal growth restriction (FGR) influences pregnancy latency among women with preterm pre-eclampsia undergoing expectant management. Secondary outcomes assessed were indication for delivery, mode of delivery and rate of serious adverse maternal and perinatal outcomes. Methods: We conducted a secondary analysis of the Pre-eclampsia Intervention (PIE) and the Pre-eclampsia Intervention 2 (PI2) trial data. These randomized controlled trials evaluated whether esomeprazole and metformin could prolong gestation of women diagnosed with pre-eclampsia between 26 and 32 weeks of gestation undergoing expectant management. Delivery indications were deteriorating maternal or fetal status, or reaching 34 weeks' gestation. FGR (defined by Delphi consensus) at the time of pre-eclampsia diagnosis was examined as a predictor of outcome. Only placebo data from PI2 were included, as the trial showed that metformin use was associated with prolonged gestation. All outcome data were collected prospectively from diagnosis of pre-eclampsia to 6 weeks after the expected due date. Results: Of the 202 women included, 92 (45.5%) had FGR at the time of pre-eclampsia diagnosis. Median pregnancy latency was 6.8 days in the FGR group and 15.3 days in the control group (difference 8.5 days; adjusted 0.49-fold change (95% CI, 0.33–0.74); P < 0.001). FGR pregnancies were less likely to reach 34 weeks' gestation (12.0% vs 30.9%; adjusted relative risk (aRR), 0.44 (95% CI, 0.23–0.83)) and more likely to be delivered for suspected fetal compromise (64.1% vs 36.4%; aRR, 1.84 (95% CI, 1.36–2.47)). More women with FGR underwent a prelabor emergency Cesarean section (66.3% vs 43.6%; aRR, 1.56 (95% CI, 1.20–2.03)) and were less likely to have a successful induction of labor (4.3% vs 14.5%; aRR, 0.32 (95% CI, 0.10–1.00)), compared to those without FGR. The rate of maternal complications did not differ significantly between the two groups. FGR was associated with a higher rate of infant death (14.1% vs 4.5%; aRR, 3.26 (95% CI, 1.08–9.81)) and need for intubation and mechanical ventilation (15.2% vs 5.5%; aRR, 2.97 (95% CI, 1.11–7.90)). Conclusion: FGR is commonly present in women with early preterm pre-eclampsia and outcome is poorer. FGR is associated with shorter pregnancy latency, more emergency Cesarean deliveries, fewer successful inductions and increased rates of neonatal morbidity and mortality. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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| 15. |
- de Boniface, Jana, 1971-
(författare)
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Sentinel Node Biopsy in Breast Cancer : Clinical and Immunological Aspects
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The most important prognostic factor in breast cancer is the axillary lymph node status. The sentinel node biopsy (SNB) is reported to stage the axilla with an accuracy > 95 % in early breast cancer. Tumour-related perturbation of T-cell function has been observed in patients with malignancies, including breast cancer. The down-regulation of the important T-cell activation molecules CD3-ζ and CD28 may cause T-cell dysfunction, anergy, tolerance and deletion.The expression of CD3-ζ and CD28 was evaluated in 25 sentinel node biopsies. The most pronounced down-regulation was seen in the paracortical area, where the best agreement between both parameters was observed. CD28 expression was significantly more suppressed in CD4+ than in CD8+ T-cells.From the Swedish sentinel node database, 109 patients with breast cancer > 3 cm planned for both SNB and a subsequent axillary dissection were identified. The false negative rate (FNR) was 12.5%. Thirteen cases of tumour multifocality were detected on postoperative pathology. The FNR in this subgroup was higher (30.8%) than in patients with unifocal disease (7.8%; P = 0.012).From the Swedish SNB multicentre cohort trial, 2246 sentinel node-negative patients who had not undergone further axillary surgery were selected for analysis. After a median follow-up time of 37 months (range 0-75), 13 isolated axillary recurrences (13/2246; 0.6%) were found. In another 14 cases, local or distant failure preceded or coincided with axillary relapse (27/2246; 1.2%). In conclusion, the immunological analysis of the sentinel node might provide valuable prognostic information and aid selection of patients for immunotherapy. SNB is encouraged in breast cancer larger than 3 cm, if no multifocal growth pattern is present. The axillary recurrence rate after a negative SNB in Sweden is in accordance with international figures. However, a longer follow-up is mandatory before the true failure rate of the SNB can be determined.
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| 16. |
- de Boniface, J., et al.
(författare)
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Survival and axillary recurrence following sentinel node-positive breast cancer without completion axillary lymph node dissection: the randomized controlled SENOMAC trial
- 2017
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: The role of axillary lymph node dissection (ALND) has increasingly been called into question among patients with positive sentinel lymph nodes. Two recent trials have failed to show a survival difference in sentinel node-positive breast cancer patients who were randomized either to undergo completion ALND or not. Neither of the trials, however, included breast cancer patients undergoing mastectomy or those with tumors larger than 5 cm, and power was debatable to show a small survival difference. Methods: The prospective randomized SENOMAC trial includes clinically node-negative breast cancer patients with up to two macrometastases in their sentinel lymph node biopsy. Patients with T1-T3 tumors are eligible as well as patients prior to systemic neoadjuvant therapy. Both breast-conserving surgery and mastectomy, with or without breast reconstruction, are eligible interventions. Patients are randomized 1: 1 to either undergo completion ALND or not by a web-based randomization tool. This trial is designed as a non-inferiority study with breast cancer-specific survival at 5 years as the primary endpoint. Target accrual is 3500 patients to achieve 80% power in being able to detect a potential 2.5% deterioration of the breast cancer-specific 5-year survival rate. Follow-up is by annual clinical examination and mammography during 5 years, and additional controls after 10 and 15 years. Secondary endpoints such as arm morbidity and health-related quality of life are measured by questionnaires at 1, 3 and 5 years. Discussion: Several large subgroups of breast cancer patients, such as patients undergoing mastectomy or those with larger tumors, have not been included in key trials; however, the use of ALND is being questioned even in these groups without the support of high-quality evidence. Therefore, the SENOMAC Trial will investigate the need of completion ALND in case of limited spread to the sentinel lymph nodes not only in patients undergoing any breast surgery, but also in neoadjuvantly treated patients and patients with larger tumors.
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| 17. |
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| 18. |
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| 19. |
- Enlund, Mats, et al.
(författare)
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Impact of general anaesthesia on breast cancer survival: a 5-year follow up of a pragmatic, randomised, controlled trial, the CAN-study, comparing propofol and sevoflurane
- 2023
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Ingår i: EClinicalMedicine. - : Elsevier. - 2589-5370. ; 60
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Tidskriftsartikel (refereegranskat)abstract
- Background Anaesthesia may impact long-term cancer survival. In the Cancer and Anaesthesia study, we hypothesised that the hypnotic drug propofol will have an advantage of at least five percentage points in five-year survival over the inhalational anaesthetic sevoflurane for breast cancer surgery. Methods From 2118 eligible breast cancer patients scheduled for primary curable, invasive breast cancer surgery, 1764 were recruited after ethical approval and individual informed consent to this open label, single-blind, randomised trial at four county- and three university hospitals in Sweden and one Chinese university hospital. Of surveyed patients, 354 were excluded, mainly due to refusal to participate. Patients were randomised by computer at the monitoring organisation to general anaesthesia maintenance with either intravenous propofol or inhaled sevoflurane in a 1:1 ratio in permuted blocks. Data related to anaesthesia, surgery, oncology, and demographics were registered. The primary endpoint was five-year overall survival. Data are presented as Kaplan-Meier survival curves and Hazard Ratios based on Cox univariable regression analyses by both intention-to-treat and perprotocol. EudraCT, 2013-002380-25 and ClinicalTrials.gov, NCT01975064. Findings Of 1764 patients, included from December 3, 2013, to September 29, 2017, 1670 remained for analysis. The numbers who survived at least five years were 773/841 (91.9% (95% CI 90.1-93.8)) in the propofol group and 764/829 (92.2% (90.3-94.0)) in the sevoflurane group, (HR 1.03 (0.73-1.44); P = 0.875); the corresponding results in the per-protocol-analysis were: 733/798 (91.9% (90.0-93.8)) and 653/710 (92.0% (90.0-94.0)) (HR = 1.01 (0.71-1.44); P = 0.955). Survival after a median follow-up of 76.7 months did not indicate any difference between the groups (HR 0.97, 0.72-1.29; P = 0.829, log rank test). Interpretation No difference in overall survival was found between general anaesthesia with propofol or sevoflurane for breast cancer surgery. Copyright (c) 2023 The Author(s). Published by Elsevier Ltd.
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| 20. |
- Fröberg, M, et al.
(författare)
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Concentration and Fluxes of Dissolved Organic Carbon (DOC) in Three Norway Spruce Stands along a Climatic Gradient in Sweden
- 2006
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 1573-515X .- 0168-2563. ; 77:1, s. 1-23
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Tidskriftsartikel (refereegranskat)abstract
- Leaching of dissolved organic carbon (DOC) from the forest floor and transport in soil solution into the mineral soil are important for carbon cycling in boreal forest ecosystems. We examined DOC concentrations in bulk deposition, throughfall and in soil solutions collected under the O and B horizons in three Norway spruce stands along a climatic gradient in Sweden. Mean annual temperature for the three sites was 5.5, 3.4 and 1.2 °C. At each site we also examined the effect of soil moisture on DOC dynamics along a moisture gradient (dry, mesic and moist plots). To obtain information about the fate of DOC leached from the O horizon into the mineral soil, 14C measurements were made on bulk organic matter and DOC. The concentration and fluxes of DOC in O horizon leachates were highest at the southern site and lowest at the northern. Average DOC concentrations at the southern, central and northern sites were 49, 39 and 30 mg l−1, respectively. We suggest that DOC leaching rates from O horizons were related to the net primary production of the ecosystem. Soil temperature probably governed the within-year variation in DOC concentration in O horizon leachates, but the peak in DOC was delayed relative to that of temperature, probably due to sorption processes. Neither soil moisture regime (dry, mesic or moist plots) nor seasonal variation in soil moisture seemed to be of any significance for the concentration of DOC leached from the O horizon. The 14C measurements showed that DOC in soil solution collected below the B horizon was derived mainly from the B horizon itself, rather than from the O horizon, indicating a substantial exchange (sorption–desorption reactions) between incoming DOC and soil organic carbon in the mineral soil.
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| 21. |
- Fröberg, M, et al.
(författare)
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Contributions of Oi, Oe and Oa horizons to dissolved organic matter in forest floor leachates
- 2003
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Ingår i: Geoderma. - 0016-7061. ; 113:3-4, s. 311-322
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to identify the role of organic matter of the Oi, Oe and Oa layers for leaching of dissolved organic matter (DOM) from the O horizon in a podsolised forest soil in southern Sweden. Solid state C-13 cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy and C-14 measurements were used to analyse organic matter in solid material and water extracts from the Oi, Oe and Oa horizons, soil leachates collected below the Oe and Oa horizons and throughfall. The DOM in soil leachates from the Oe horizon had a C-14 content that was higher than the water extractable organic matter (WEOM) from the Oi horizon but equal to the C-14 content in the WEOM from the Oe horizon. The C-14 contents in WEOM and DOM from the Oe and Oa horizons were all equal. These results suggest that the DOM leaving the Oe horizon to a large extent had its origin within the Oe horizon itself. NMR spectroscopy showed that WEOM was higher in O-alkyl and lower in aromatic carbon than DOM in soil leachates.
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| 22. |
- Fröberg, M, et al.
(författare)
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Dissolved Organic Carbon Leaching from a Coniferous Forest Floor - A Field Manipulation Experiment
- 2005
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 1573-515X .- 0168-2563. ; 75:2, s. 271-287
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Tidskriftsartikel (refereegranskat)abstract
- Leaching of dissolved organic carbon (DOC) from the O layer is important for the carbon cycling of forest soils. Here we study the role of the Oi, Oe and Oa horizons in DOC leaching from the forest floor in field manipulations carried out in a Norway spruce forest stand in southern Sweden. The manipulations involved the addition and removal of litter and the removal of Oi, Oe and Oa horizons. Our data suggest that both recent litter and humified organic matter contribute significantly to the leaching of dissolved organic matter from the O layer. An addition of litter corresponding to four times annual litterfall resulted in a 35% increase in DOC concentrations and fluxes although the specific UV absorbance remained unchanged. The removal of litterfall and the Oi horizon resulted in a decreased DOC concentration and in a significant increase in the molar UV absorptivity. The DOC concentration under the Oa horizon was not significantly different from that under the Oe horizon and there were no increase in DOC flux, but rather a decrease, from the bottom of the Oe horizon to the bottom of the Oa horizon, suggesting that there is no net release of DOC in the Oa horizon. However, significant leaching of DOC occurred from the Oa horizon when litterfall and the Oi and Oe horizons were removed. This indicates that there is both a removal of DOC from the Oi and Oe horizons and a substantial production of DOC in the Oa horizon. Quantitatively, we suggest that the Oi, Oe and Oa horizons contributed approximately 20, 30 and 50%, respectively, to the overall leaching of DOC from the O layer.
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| 23. |
- Hellsten, Torbjörn, 1947-, et al.
(författare)
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Fast Wave Current Drive and Direct Electron Heating in JET ITB Plasmas
- 2006
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Ingår i: Proc 21st IAEA Fusion Energy Conference.
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Konferensbidrag (refereegranskat)abstract
- Experiments with Fast Wave Current Drive, FWCD, and heating have been carried out in JET Internal Transport Barrier (ITB) discharges with strongly reversed magnetic shear. In order to maximize the current drive efficiency and increase the electron damping, and at the same time modifying the current profile in the transport barrier, hot low density ITB plasmas with strongly reversed magnetic shear, close to current hole, were created with Lower Hybrid Current Drive. It was difficult to strongly modify the central plasma current, even though the calculated current drive efficiency in terms of ampere per watts absorbed by the electrons was fairly high, 0.07A/W, because of: the strongly inductive nature of the plasma current due to the high electric conductivity; the interplay between the fast wave driven current and the bootstrap current, which, due to the dependence of the bootstrap current on the poloidal magnetic field, decreases the bootstrap current as the driven current increases; and parasitic absorption of the waves that decreased the power absorbed by the electrons. The power absorbed by the electrons was measured with a power modulation technique and the associated fast wave current drive calculated. Current diffusion simulations using the JETTO transport code, assuming neoclassical resistivity, were then carried out to calculate what changes to the plasma current profile could be expected from the current drive. The simulations showed a much slower response to the current drive compared to the measured central current densities suggesting a faster current penetration in the experiments than expected from neoclassical theory. Whereas the direct electron heating by fast magnetosonic waves using dipole spectra has proven to be an effective method to heat electrons in high-temperature ITB plasmas, even for a single pass damping of only a few percent, the heating in FWCD experiments with + 90o and - 90o antenna phasings were, for similar single pass damping as for the dipole, strongly degraded by parasitic losses, and with a heating efficiency of about half that of the dipole. Observations supporting that the losses are primarily caused by the presence of rectified RF-sheath potentials come from the large differences in performance and in Beryllium-II and Carbon-IV line radiation intensities between the dipole and ±90o phasings.
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| 24. |
- Kolberg, D., et al.
(författare)
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Effect of Rhizome Fragmentation, Clover Competition, Shoot-Cutting Frequency, and Cutting Height on Quackgrass (Elymus repens)
- 2018
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Ingår i: Weed science. - : Cambridge University Press. - 0043-1745 .- 1550-2759. ; 66:2, s. 215-225
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Tidskriftsartikel (refereegranskat)abstract
- Quackgrass is a problematic agricultural weed in the temperate zones of the world and is difficult to control without herbicides or intensive tillage. However, it may be possible to control quackgrass with less environmental impact by combining multiple low-intensity control methods. A pot experiment was conducted in July to October 2012 and repeated in June to September 2013 to investigate the effect of rhizome fragmentation, competition from white clover, shoot-cutting frequency, and cutting height on quackgrass. Rhizome fragmentation was expected to result in more, but weaker, quackgrass shoots that would be more vulnerable to shoot cutting and competition. However, by 20 d past planting, rhizome fragmentation did not change the total number of quackgrass shoots per pot, because an increase in main shoots was offset by a decrease in tiller numbers. Rhizome fragmentation did not reduce quackgrass biomass acquisition during the experimental period. Although rhizome fragmentation did reduce total fructan content, it did not enhance the effect of clover competition, shoot-cutting frequency, or shoot-cutting height. Clover competition by itself reduced quackgrass shoot numbers by 72%, rhizome biomass by 81%, and belowground fructan concentration by 10 percentage points, compared with no competition. The more frequently quackgrass shoots were cut, the less biomass quackgrass acquired, and a high shoot-cutting frequency (each time quackgrass reached 2 leaves) resulted in a lower belowground fructan concentration than a low shoot-cutting frequency (at 8 leaves). However, in pots without competition, a higher shoot-cutting frequency resulted in more quackgrass shoots. A lower shoot-cutting height (25 mm) had more impact when shoot cutting was more frequent. In conclusion, rhizome fragmentation did not reduce the number of quackgrass shoots or rhizome biomass, but competition from white clover, a high shoot-cutting frequency, and a low shoot-cutting height strongly suppressed quackgrass biomass and fructan acquisition.
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| 25. |
- Persson, F., et al.
(författare)
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The risk of symptomatic knee osteoarthritis after arthroscopic meniscus repair vs partial meniscectomy vs the general population
- 2018
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Ingår i: Osteoarthritis and Cartilage. - : Elsevier BV. - 1063-4584. ; 26:2, s. 195-201
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare consultation rate for knee osteoarthritis (OA) after meniscus repair, arthroscopic partial meniscectomy (APM), and in general population, respectively. Method: We identified patients aged 16-45 years having had meniscus surgery due to traumatic meniscus tear in 1998-2010 in southern Sweden by a healthcare register. Patients were followed from surgery until a diagnosis of knee OA, relocation, death, or December 31st, 2015. We studied the consultation rate for knee OA compared to the general population. Results: We identified 2,487 patients diagnosed with traumatic meniscus tear (mean [SD] age 30.5 [8.6] years); 229 (9.2%) of them had had meniscus repair. The absolute risk of having consulted for knee OA during the study was 17% after APM, 10.0% after meniscus repair, and 2.3% in the general population. Hazard ratio (HR) (95% confidence interval (CI)) for knee OA after repair vs APM was: 0.74 (0.48, 1.15). Excluding cases with OA within 2 years post-surgery, yielded the HR of 0.51 (0.27, 0.96). The consultation rate for knee OA standardized to the general population was then 42 per 10,000 person-years (95% CI 12, 71) in the meniscus repair group, 118 per 10,000 person-years (95% CI 101, 135) after APM, and 20 per 10,000 person-years (95% CI 19.9, 20.1) in the general population. Conclusion: The point estimates suggests about 25-50% lower risk of consultation for knee OA after meniscus repair as compared to APM. However, the consultation rate for knee OA after repair was still at least two times higher as compared to the general population.
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| 26. |
- Sjöberg, G, et al.
(författare)
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Long-term N addition effects on the C mineralization and DOC production in mor humus under spruce
- 2003
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Ingår i: Soil Biology & Biochemistry. - 0038-0717. ; 35:10, s. 1305-1315
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Tidskriftsartikel (refereegranskat)abstract
- This study was based on laboratory incubations of mor humus from two N fertilized stands of Norway spruce in Sweden (Skogaby and Strasan), which had received repeated N additions (100 kg N ha(-1) yr(-1) as (NH4)(2)SO4 at Skogaby and 35, 73 and 108 kg ha(-1) yr(-1), as NH4NO3 at Strasan) during 8 and 24-29 years, respectively. The aim was to investigate long-term N effects on the mineralization of C and production of DOC. Mor humus (Oe and Oa) was incubated in columns at 20 degreesC for 49 days. Columns were leached once a week with artificial throughfall solution, which was analyzed for DOC, total N, NH4+-N and NO3--N. Prior to each leaching event, CO2 evolution from the columns was determined. C-to-N ratios in the N-treated Oe layers at Strasan (21-24) and Skogaby (24) were significantly lower than those of the controls (Strasan, 32; Skogaby, 28). The cumulative amount Of CO2-C showed a significant treatment effect in the Oe layer at Skogaby, i.e. 18 and 29 mg C g(-1) C in the N treatment and control, respectively. At Strasan, the cumulative CO2-C was significantly lower in the N3 treatment compared to the control in both layers (33 compared to 74 mg C g(-1) C in the Oe layer and 16 compared to 35 mg C g(-1) C in the Oa layer). Neither the DOC nor the DON production showed any significant treatment effects at the two sites. However, DOC was lower in the fertilized Oe layer at Skogaby throughout the incubation. The leaching of DON was highest in the Oe layers at both sites, and DON increased with time at Skogaby while there was a decreasing trend at Strasan. The DOC-to-DON ratio tended to be lower in the fertilized Oe layers at both sites. The NH4+ leaching at Skogaby decreased in the N-treated Oe and Oa layers. At Strasan, NH4+ from the Oe layer increased in N2 and control. The NO3- leaching was low and constant in both Skogaby layers. At Strasan, NO3- increased in the Oe layer of N1. Cumulative CO2 was positively correlated to C-to-N ratio (r(2) = 0.71, p < 0.01) and to cumulative DOC (r(2) = 0.63, p < 0.05) in the Oe layer at Strasan. Our conclusion was that long-term N additions caused decreased C-to-N ratios and decreased CO2 evolution rates. The correlation between CO2 and C-to-N ratio in the Oe layers at Strasan may be due to a changed quality of the fertilized forest floor material and presence of more N efficient microorganisms.
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| 27. |
- Tipping, E, et al.
(författare)
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DOC leaching from a coniferous forest floor: modeling a manipulation experiment
- 2005
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Ingår i: Journal of Plant Nutrition and Soil Science. - : Wiley. - 1436-8730 .- 1522-2624. ; 168:3, s. 316-324
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Tidskriftsartikel (refereegranskat)abstract
- The DyDOC model simulates the C dynamics of forest soils, including the production and transport of dissolved organic matter (DOM), on the basis of soil hydrology, metabolic processes, and sorption reactions. The model recognizes three main pools of soil C: litter, substrate (an intermediate transformation product), and humic substances. The model was used to simulate the behavior of C in the 0 horizon of soil under a Norway spruce stand at Asa, Sweden, that had been subjected to experimental manipulations (addition and removal) of above-ground litter inputs and to removal of the Oi and Oe layers. Initially, the model was calibrated using results for the control plots and was able to reproduce the observed total soil C pool and C-14 content, DOC flux and DO C-14 content, and the pool of litter C, together with the assumed content of C in humic substances (20% of the total soil C), and the assumed distribution of DOC between hydrophilic and hydrophobic fractions. The constant describing DOC exchange between micro- and macropores was estimated from short-term variations in DOC concentration. When the calibrated model was used to predict the effects of litter and soil manipulations, it underestimated the additional DOC export (up to 33%) caused by litter addition, and underestimated the 22% reduction in DOC export caused by litter withdrawal. Therefore, an additional metabolic process, the direct conversion of litter to DOC, was added to the model. The addition of this process permitted reasonably accurate simulation of the results of the manipulation experiments, without affecting the goodness-of-fit in the model calibration. The results suggest that, under normal conditions, DOC exported from the Asa forest floor is a mixture of compounds derived from soil C pools with a range of residence times. Approximately equal amounts come from the litter pool (turnover time 4.6 yr), the substrate pool (26 yr), and the humic-substances pool (36 yr).
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