| 1. |
- Ericson, Petrea, 1966, et al.
(författare)
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Low Levels of Exhaled Surfactant Protein A Associated With BOS After Lung Transplantation
- 2016
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Ingår i: Transplantation Direct. - : Ovid Technologies (Wolters Kluwer Health). - 2373-8731. ; 2:9
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Tidskriftsartikel (refereegranskat)abstract
- Background. There is no clinically available marker for early detection or monitoring of chronic rejection in the form of bronchiolitis obliterans syndrome (BOS), the main long-term complication after lung transplantation. Sampling and analysis of particles in exhaled air is a valid, noninvasive method for monitoring surfactant protein A (SP-A) and albumin in the distal airways. Methods. We asked whether differences in composition of exhaled particles can be detected when comparing stable lung transplant recipients (LTRs) (n = 26) with LTRs who develop BOS (n = 7). A comparison between LTRs and a matching group of healthy controls (n = 33) was also conducted. Using a system developed in-house, particles were collected from exhaled air by the principal of inertial impaction before chemical analysis by immunoassays. Results. Surfactant protein A in exhaled particles and the SP-A/albumin ratio were lower (P = 0.002 and P = 0.0001 respectively) in the BOS group compared to the BOS-free group. LTRs exhaled higher amount of particles (P < 0.0001) and had lower albumin content (P < 0.0001) than healthy controls. Conclusions. We conclude that low levels of SP-A in exhaled particles are associated with increased risk of BOS in LTRs. The possibility that this noninvasive method can be used to predict BOS onset deserves further study with prospective and longitudinal approaches.
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| 2. |
- Fredriksson, Sofie, 1983, et al.
(författare)
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The effect of occupational noise exposure on tinnitus and sound-induced auditory fatigue among obstetrics personnel: a cross-sectional study.
- 2015
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Objective There is a lack of research on effects of occupational noise exposure in traditionally female-dominated workplaces. Therefore, the aim of this study was to assess risk of noise-induced hearing-related symptoms among obstetrics personnel. Design A cross-sectional study was performed at an obstetric ward in Sweden including a questionnaire among all employees and sound level measurements in 61 work shifts at the same ward. Participants 115 female employees responded to a questionnaire (72% of all 160 employees invited). Main outcome measures Self-reported hearing-related symptoms in relation to calculated occupational noise exposure dose and measured sound levels. Results Sound levels exceeded the 80dB LAeq limit for protection of hearing in 46% of the measured work shifts. One or more hearing-related symptoms were reported by 55% of the personnel. In logistic regression models, a significant association was found between occupational noise exposure dose and tinnitus (OR=1.04, 95% CI 1.00 to 1.09) and sound-induced auditory fatigue (OR=1.04, 95% CI 1.00 to 1.07). Work-related stress and noise annoyance at work were reported by almost half of the personnel. Sound-induced auditory fatigue was associated with work-related stress and noise annoyance at work, although stress slightly missed significance in a multivariable model. No significant interactions were found. Conclusions This study presents new results showing that obstetrics personnel are at risk of noise-induced hearing-related symptoms. Current exposure levels at the workplace are high and occupational noise exposure dose has significant effects on tinnitus and sound-induced auditory fatigue among the personnel. These results indicate that preventative action regarding noise exposure is required in obstetrics care and that risk assessments may be needed in previously unstudied non-industrial communication-intense sound environments.
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| 3. |
- Fredriksson, Sofie, 1983, et al.
(författare)
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Validating self-reporting of hearing-related symptoms against pure-tone audiometry,otoacoustic emission, and speech audiometry
- 2016
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 55:8, s. 454-62
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To validate self-reported hearing-related symptoms among personnel exposed to moderately high occupational noise levels at an obstetrics clinic. Design: Sensitivity, specificity, and predictive values were calculated for questionnaire items assessing hearing loss, tinnitus, sound sensitivity, poor hearing, difficulty perceiving speech, and sound-induced auditory fatigue. Hearing disorder was diagnosed by pure-tone audiometry, distortion Product otoacoustic emissions, and HINT (Hearing In Noise Test). Study sample: Fifty-five female obstetrics personnel aged 22–63 participated; including 26 subjects reporting hearing loss, poor hearing, tinnitus, or sound sensitivity, and 29 randomly selected subjects who did not report these symptoms. Results: The questionnaire item assessing sound-induced auditory fatigue had the best combination of sensitivity 85% (95% CIs 56 to 100%)and specificity 70% (95% CIs 55 to 84%) for hearing disorder diagnosed by audiometry or otoacoustic emission. Of those reporting sound-induced auditory fatigue 71% were predicted to have disorder diagnosed by otoacoustic emission. Participants reporting any hearing-related symptom had slightly worse measured hearing. Conclusions: We suggest including sound-induced auditory fatigue in questionnaires for identification of hearing disorder among Healthcare personnel, though larger studies are warranted for precise estimates of diagnostic performance. Also, more specific and accurate hearing tests are needed to diagnose mild hearing disorder.
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| 4. |
- Hammar, Oscar, 1977
(författare)
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Inference in a Partially Observed Percolation Process
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this licentiate thesis, inference in a partially oberved percolation process living on a graph, is considered. Each edge of the graph is declared open with probability $\theta$ and closed with probability $1-\theta$ independently of the states of all other edges. The inference problem is to draw inference about $\theta$ based on the information on whether or not particular pairs of vertices are connected by open paths. Consistency results under certain conditions on the graph are given for both a Bayesian and a frequentist approach to the inference problem. Moreover, a simulation study is presented which in addition to illustrating the consistency results, also indicates that the consistency results might hold for percolation processes on more general graphs.
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| 5. |
- Hammar, Oscar, 1977
(författare)
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Percolation: Inference and Applications in Hydrology
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Percolation theory is a branch of probability theory describing connectedness in a stochastic network. The connectedness of a percolation process is governed by a few, typically one or two, parameters. A central theme in this thesis is to draw inference about the parameters of a percolation process based on information whether particular points are connected or not. Special attention is paid to issues of consistency as the number of points whose connectedness is revealed tends to infinity. A positive result concerns Bayesian consistency for a bond percolation process on the square lattice $\mathbb{L}^2$ - a process obtained by independently removing each edge of $\mathbb{L}^2$ with probability $1-p$. Another result on Bayesian consistency relates to a continuum percolation model which is obtained by placing discs of fixed radii at each point of a Poisson process in the plane, $\mathbb{R}^2$. Another type of results concerns the computation of relevant quantities for the inference related to percolation processes. Convergence of MCMC algorithms for the computation of the posterior, for bond percolation on a subset of $\mathbb{L}^2$, and the continuum percolation, on a subset of $\mathbb{R}^2$, is proved. The issue of convergence of a stochastic version of the EM algorithm for the computation of the maximum likelihood estimate for a bond percolation problem is also considered. Finally, the theory is applied to hydrology. A model of a heterogeneous fracture amenable for a percolation theory analysis is suggested and the fracture's ability to transmit water is related to the fractures median aperture.
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| 6. |
- Larsson, Per, et al.
(författare)
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Exhaled particles as markers of small airway inflammation in subjects with asthma
- 2017
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961. ; 37:5, s. 489-497
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled breath contains suspended particles of respiratory tract lining fluid from the small airways. The particles are formed when closed airways open during inhalation. We have developed a method called Particles in Exhaled air (PExA((R))) to measure and sample these particles in the exhaled aerosol. Here, we use the PExA((R)) method to study the effects of birch pollen exposure on the small airways of individuals with asthma and birch pollen allergy. We hypothesized that birch pollen-induced inflammation could change the concentrations of surfactant protein A and albumin in the respiratory tract lining fluid of the small airways and influence the amount of exhaled particles. The amount of exhaled particles was reduced after birch pollen exposure in subjects with asthma and birch pollen allergy, but no significant effect on the concentrations of surfactant protein A and albumin in exhaled particles was found. The reduction in the number of exhaled particles may be due to inflammation in the small airways, which would reduce their diameter and potentially reduce the number of small airways that open and close during inhalation and exhalation.
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| 7. |
- Persson Waye, Kerstin, 1959, et al.
(författare)
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Rail freight vibration impacts sleep and community response: An overview of CargoVibes
- 2014
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Ingår i: ICBEN 2014, the 11th International Congress on Noise as a Public Health Problem. Nara, Japan, 2014 June 1 to June 5.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The European Union funded CargoVibes project involving 10 partners from 8 nations has aimed to examine ground-borne vibration affecting residents close to freight railway lines. This poster presents an overview of the work package investigating human response to vibration, with particular focus on physiological and psychological impact on sleep, community annoyance and the development of guidance in evaluating response. The effects of vibration on sleep were measured in a series of laboratory trials at the University of Gothenburg. Existing field studies of community response were supplemented with further field work in the Netherlands and Poland, and a meta-analysis conducted to determine dose-response relationships for railway vibration. Numerous outcomes of vibration exposure were found, with physiological markers such as greater heart rate response and cortical reactions during sleep, and annoyance and sleep disturbance increasing with higher vibration amplitudes. A guidance document considering current state of the art regarding vibration measurement and assessment was produced pertaining to human perception, evaluation methods, annoyance, sleep impacts, and non-exposure factors. The outcomes of this work represent a significant advance in the understanding of the human response to railway vibration and a step towards a much needed harmonisation of assessment methods. The findings presented in this poster highlight the importance of considering environmental vibration in the planning, construction, and maintenance of railways in residential environments.
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| 8. |
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| 9. |
- Smith, Michael, et al.
(författare)
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Freight trains, nocturnal vibration and noise, and their physiological effects during sleep
- 2014
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Ingår i: 11th International Congress on Noise as a Public Health Problem (ICBEN) 2014, Nara, JAPAN. Proceedings of ICBEN 2014.
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Konferensbidrag (refereegranskat)abstract
- There has been much previous research examining the effects of environmental noise on sleep, but the specific influence of vibration exposure has largely been neglected and primarily limited to cross-sectional field studies. Within the EU CargoVibes project, we experimentally investigated physiological reactions to freight train vibration and noise exposure during sleep. Polysomnography was used to determine the impact on sleep architecture, in terms of macrostructure and for event-related autonomic and cortical arousals. The work aimed to examine the effects on sleep of vibration amplitude, number of events, and the interaction of vibration and noise. Nights with 36 events and high vibration were found to result in greatest sleep fragmentation, more changes to lighter sleep stage, shorter continuous time in slow wave sleep and earlier awakenings than the control, and increased wakefulness and reduced rapid eye movement sleep relative to the 20 train night. The likelihood of the occurrence of event-related awakenings, arousals and changes in sleep depth all increased with vibration amplitude. Heart rate response was greater during exposure to high than moderate vibration. Comparison between first and second half of the night indicated that cardiac reactions sensitized to repeated vibration exposure. Vibration in residential environments from railway freight contributes towards sleep fragmentation which may have implications for health outcomes. Guidelines to prevent adverse health outcomes for freight lines where there is a risk for vibration exposure therefore need to consider not only noise but also the added impact of vibration.
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| 10. |
- Smith, Michael, et al.
(författare)
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Nocturnal vibration and noise from freight trains impacts sleep
- 2013
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Ingår i: Proceedings of Meetings on Acoustics. - : ASA. - 1939-800X.
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Konferensbidrag (refereegranskat)abstract
- There is a proposed increase in the number of freight trains on the European railway networks, with this growth being facilitated through using the available night time periods. Freight trains are particularly problematic with regards to generation of low frequency vibration and noise which has the potential to propagate to nearby homes and influence the sleep of residents. To investigate the potential impact we conducted a laboratory trial on 24 young healthy persons to ascertain physiological and psychological reactions to nocturnal vibration and noise from freight traffic, and to examine differences between gender and noise sensitivity. Nights with moderate (0.0102 m/s2) and high (0.0204 m/s2) maximum Wd weighted vibration amplitudes and low (20) and high (36) number of train passages were simulated with noise levels being of the same order between nights. Polysomnography was used to record sleep stage and EEG arousals and awakenings. Event-related cardiac activations were analysed using ECG recordings. Questionnaires were administered to obtain subjective sleep parameters. Sleep was more fragmented during nights with higher vibration amplitudes and number of events. Furthermore, heart rate response was higher in the high vibration condition. Results from the subjective data showed less discrimination between nights.
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