| 361. |
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| 362. |
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| 363. |
- Persson, Anders, et al.
(författare)
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Optogalvanic spectroscopy with microplasma sources – Current status and development towards Lab-On-A-Chip
- 2015
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Konferensbidrag (refereegranskat)abstract
- Miniaturized optogalvanic spectros-copy shows excellent prospects of becoming a highly sensitive method for gas analysis in micro total analysis systems. Here, a status report on the current development of microplasma sources for optogalvan-ic spectroscopy is presented, together with the first comparison of the sensitivity of the method to con-ventional single-pass absorption spectroscopy. The stability and reproducibility of the microplasma source when used as a detector for optogalvanic spectroscopy is also investigated, and a roadmap of future developments is presented, with the particular focus of integrating sensors for measuring the pres-sure, temperature and flow of the sample gas through the detector, and combining the detector with a miniaturized combustor to allow for studies of solid samples.
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| 364. |
- Persson, Anders, et al.
(författare)
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Optogalvanic spectroscopy with microplasma sources – Current status and development towards lab on a chip
- 2016
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 26:10
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Tidskriftsartikel (refereegranskat)abstract
- Miniaturized optogalvanic spectroscopy (OGS) shows excellent prospects of becoming ahighly sensitive method for gas analysis in micro total analysis systems. Here, a status reporton the current development of microwave induced microplasma sources for OGS is presented,together with the first comparison of the sensitivity of the method to conventional single-passabsorption spectroscopy. The studied microplasma sources are stripline split-ring resonators(SSRRs), with typical ring radii between 3.5 and 6 mm and operation frequencies around2.6 GHz. A linear response (R2 = 0.9999), and a stability of more than 100 s are demonstratedwhen using the microplasma source as an optogalvanic detector. Additionally, saturationeffects at laser powers higher than 100 mW are observed, and the temporal response of theplasma to periodic laser perturbation with repletion rates between 20 Hz and 200 Hz arestudied. Finally, the potential of integrating additional functionality with the detector isdiscussed, with the particular focus on a pressure sensor and a miniaturized combustor toallow for studies of solid samples.
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| 365. |
- Persson, Anders Paul, et al.
(författare)
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Heart rate and premature atrial contractions at 24hECG independently predict atrial fibrillation in a population-based study
- 2020
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Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 106:4, s. 287-291
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Low resting heart rate and premature atrial contractions (PACs) predict incident atrial fibrillation (AF) and could be interdependent, since PACs occur in the gaps between normal beats.OBJECTIVE: To study the association between low heart rate at 24hECG, PACs and incident AF in a prospective population-based cohort.METHODS: In the Malmö Diet and Cancer study, 24hECGs were performed in 377 AF-free subjects. The endpoint was clinical AF retrieved from national hospital (mean follow-up 17 years). The interaction between increased supraventricular activity (SVA) top quartile of either PACs/hour or supraventricular tachycardias/hour) and mean heart rate (mHR) as regards AF risk was assessed in multivariable Cox regression analyses adjusted for age, sex, height, BMI, systolic blood pressure, antihypertensive medication, smoking and homeostasis model assessment of insulin resistance.RESULTS: There were 80 (21%) incident cases of AF. Below median mHR (80 bpm/75 bpm for women/men) was associated with increased AF incidence (HR: 1.89, 95% CI 1.18 to 3.02, p=0.008). There was no correlation between mHR and SVA (p=0.6) or evidence of a multiplicative interaction between these factors for AF risk (p for interaction=0.6) In the group with both increased SVA and below median mHR (17% of the population) the relative risk of AF was very high (HR 4.5, 95% CI 2.2 to 9.1, p=0.001).CONCLUSION: Low mHR at 24hECG independently predicts AF, but there is no association between mHR and SVA, and these factors are independent as regards AF risk. Subjects with both low mHR and increased SVA have high AF risk.
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| 366. |
- Persson, Anders Paul, et al.
(författare)
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Reference ranges for ambulatory heart rate measurements in a middle-aged population
- 2024
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Ingår i: Heart. - 1355-6037. ; 110:12, s. 831-837
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Elevated heart rate (HR) predicts cardiovascular disease and mortality, but there are no established normal limits for ambulatory HR. We used data from the Swedish CArdioPulmonary Imaging Study to determine reference ranges for ambulatory HR in a middle-aged population. We also studied clinical correlates of ambulatory HR.METHODS: A 24-hour ECG was registered in 5809 atrial fibrillation-free individuals, aged 50-65 years. A healthy subset (n=3942) was used to establish reference values (excluding persons with beta-blockers, cardiovascular disease, hypertension, heart failure, anaemia, diabetes, sleep apnoea or chronic obstructive pulmonary disease).Minimum HR was defined as the lowest 1-minute HR. Reference ranges are reported as means±SDs and 2.5th-97.5th percentiles. Clinical correlates of ambulatory HR were analysed with multivariable linear regression.RESULTS: The average mean and minimum HRs were 73±9 and 48±7 beats per minute (bpm) in men and 76±8 and 51±7 bpm in women; the reference range for mean ambulatory HR was 57-90 bpm in men and 61-92 bpm in women. Average daytime and night-time HRs are also reported. Clinical correlates, including age, sex, height, body mass index, physical activity, smoking, alcohol intake, diabetes, hypertension, haemoglobin level, use of beta-blockers, estimated glomerular filtration rate, per cent of predicted forced expiratory volume in 1 s and coronary artery calcium score, explained <15% of the interindividual differences in HR.CONCLUSION: Ambulatory HR varies widely in healthy middle-aged individuals, a finding with relevance for the management of patients with a perception of tachycardia. Differences in ambulatory HR between individuals are largely independent of common clinical correlates.
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| 367. |
- Persson, Anders
(författare)
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Palestine at the end of the state-building process: Technical achievements, political failures
- 2018
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Ingår i: Mediterranean Politics. - : Informa UK Limited. - 1362-9395 .- 1743-9418. ; 23:4, s. 433-452
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Tidskriftsartikel (refereegranskat)abstract
- More than two decades of Palestinian state-building have produced neither peace nor a state. In fact, the Palestinians are seemingly further away from statehood today than at any point since the state-building process began in the mid-90s, despite the fact that the West Bank’s institutions now perform, according to the UN, the EU, the World Bank and IMF, above the threshold for what is expected of a state. In this situation – with the Palestinians technically ready for statehood and large parts of Europe and the U.S. not politically ready to recognize Palestine – it is unclear what strategic objectives the internationally supported state-building process now can achieve in the Palestinian territories, except for upholding the status quo.
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| 368. |
- Persson, Anders, et al.
(författare)
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Passive versus active operator work in automated process control - a job design case study in a control center
- 2001
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Ingår i: Applied Ergonomics. - 1872-9126. ; 32:5, s. 441-451
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Tidskriftsartikel (refereegranskat)abstract
- Methods of avoiding common problems associated with operator work in automated process control, such as understimulation and difficulties in achieving and maintaining necessary skills and competence, are addressed in this paper. The source of these problems is deduced here to be that monitoring tasks are a predominant part of the job. This case study shows how work in a highly automated process can be designed not only to avoid the traditional problems, but also provide a stimulating job within a good work situation at the same time as fulfilling efficiency demands. A new definition of active/passive operator jobs is made which is based on categorisation of the types of work tasks that make up the job. The definition gives an explanation of how different designs of operator jobs result in more or less active/passive work situations.
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| 369. |
- Persson, Anders
(författare)
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Phosphorus Release by Fish in Relation to External and Internal Load in a Eutrophic Lake
- 1997
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Ingår i: Limnology and Oceanography. - 1939-5590. ; 42:3, s. 577-583
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare the rate of phosphorus release from fish with estimates of external and internal load in the eutrophic Finjasjon, Sweden. Phosphorus release from roach and bream, when fed either benthic (Chironomidae) or pelagic (Daphnia) prey, was measured in laboratory tanks. These results were transformed to whole lake conditions by using calculated fish consumption rates of both benthic and pelagic prey based on field data for the community structure, growth rate, and diet of the fish. Phosphorus (P) release from the fish was on the average 0.53 mg P m-2 d-1, which was of the same magnitude (110% of external load) as the external load and 42% of the internal load. Most of the P released from the fish was of pelagic origin, being recycled within the water column. Some 18% of the released P was due to benthic feeding, mainly by large bream, thus representing P translocated from the sediment to the water. This last component of the P release constituted 27% of the external and 10% of the internal load. The P release from fish was in a form directly available to phytoplankton, suggesting that P release from fish may be an important nutrient source for algae.
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| 370. |
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