| 1. |
- Skaar, Karin, et al.
(författare)
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Crystal structure of the bacteriophage P2 integrase catalytic domain
- 2015
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 589:23, s. 3556-3563
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Tidskriftsartikel (refereegranskat)abstract
- Bacteriophage P2 is a temperate phage capable of integrating its DNA into the host genome by site-specific recombination upon lysogenization. Integration and excision of the phage genome requires P2 integrase, which performs recognition, cleavage and joining of DNA during these processes. This work presents the high-resolution crystal structure of the catalytic domain of P2 integrase, and analysis of several non-functional P2 integrase mutants. The DNA binding area is characterized by a large positively charged patch, harbouring key residues. The structure reveals potential for large dimer flexibility, likely essential for rearrangement of DNA strands upon integration and excision.
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| 2. |
- Alsholm, Linda, et al.
(författare)
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Interrupted transport by the emergency medical service in stroke/transitory ischemic attack : A consequence of changed treatment routines in prehospital emergency care.
- 2019
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Ingår i: Brain and Behavior. - : Wiley. - 2162-3279 .- 2162-3279.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The discovery that not all patients who call for the emergency medical service (EMS) require transport to hospital has changed the structure of prehospital emergency care. Today, the EMS clinician at the scene already distinguishes patients with a time-critical condition such as stroke/transitory ischemic attack (TIA) from patients without. This highlights the importance of the early identification of stroke/TIA.AIM: To describe patients with a final diagnosis of stroke/TIA whose transport to hospital was interrupted either due to a lack of suspicion of the disease by the EMS crew or due to refusal by the patient or a relative/friend.METHODS: Data were obtained from a register in Gothenburg, covering patients hospitalised due to a final diagnosis of stroke/TIA. The inclusion criterion was that patients were assessed by the EMS but were not directly transported to hospital by the EMS.RESULTS: Among all the patients who were assessed by the EMS nurse and subsequently diagnosed with stroke or TIA in 2015, the transport of 34 of 1,310 patients (2.6%) was interrupted. Twenty-five of these patients, of whom 20 had a stroke and five had a TIA, are described in terms of initial symptoms and outcome. The majority had residual symptoms at discharge from hospital. Initial symptoms were vertigo/disturbed balance in 11 of 25 cases. Another three had symptoms perceived as a change in personality and three had a headache.CONCLUSION: From this pilot study, we hypothesise that a fraction of patients with stroke/TIA who call for the EMS have their direct transport to hospital interrupted due to a lack of suspicion of the disease by the EMS nurse at the scene. These patients appear to have more vague symptoms including vertigo and disturbed balance. Instruments to identify these patients at the scene are warranted.
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| 3. |
- Angré, Alexander, et al.
(författare)
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Phase transformation under isostatic pressure in HIP
- 2017
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Ingår i: Powder Metallurgy. - : Informa UK Limited. - 0032-5899 .- 1743-2901. ; 60:3, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- The new HIP cooling systems enable very fast cooling rates under isostatic pressure. This does not only enable shorter HIP cycles but also allows complete heat treatment cycles to be performed in one HIP cycle. It has been shown in previous studies that extreme pressures of several thousand bar can push phase transformation towards longer times. The new URQ HIP cooling systems give the opportunity to investigate the impact of pressures up to 2000 bar on phase transformation time dependency. For each of the two materials in this study, a comparison of austenite phase transformation time at 100 and 1700 bar was performed. The study was performed by isothermal heat treatment of specimens for a specific time followed by quenching. To evaluate the influence of pressure on hardenability, the phase fractions were evaluated using grid method on SEM images. The study found significant influence of HIP pressure on hardenability.
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| 4. |
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| 5. |
- Bastardo Zambrano, Luis Alejandro, et al.
(författare)
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The structures of complexes between polyethylene imine and sodium dodecyl sulfate in D2O : a scattering study
- 2005
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 109:1, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- The association between a highly branched polyelectrolyte with ionizable groups, polyethylene imine (PEI), and an anionic surfactant, sodium dodecyl sulfate (SDS), has been investigated at two pH values, using small-angle neutron and light scattering. The scattering data allow us to obtain a detailed picture of the association structures formed. Small-angle neutron scattering (SANS) measurements in solutions containing highly charged PEI at low pH and low SDS concentrations indicate the presence of disklike aggregates. The aggregates change to a more complex three-dimensional structure with increasing surfactant concentration. One pronounced feature in the scattering curves is the presence of a Bragg-like peak at high q-values observed at a surfactant concentration of 4.2 mM and above. This scattering feature is attributed to the formation of a common well-ordered PEI/SDS structure, in analogue to what has been reported for other polyelectrolyte-surfactant systems. Precipitation occurred at the charge neutralization point, and X-ray diffraction measurements on the precipitate confirmed the existence of an ordered structure within the PEI/SDS aggregates, which was identified as a lamellar internal organization. Polyethylene imine has a low charge density in alkaline solutions. At pH 10.1 and under conditions where the surfactant was contrast matched, the SANS scattering curves showed only small changes with increasing surfactant concentration. This suggests that the polymer acts as a template onto which the surfactant molecules aggregate. Data from both static light scattering and SANS recorded under conditions where SDS and to a lower degree PEI contribute to the scattering were found to be consistent with a structure of stacked elliptic bilayers. These structures increased in size and became more compact as the surfactant concentration was increased up to the charge neutralization point.
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| 6. |
- Berg, Magnus, et al.
(författare)
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A combined on-line PCA-ICA algorithm for blind source separation
- 2005
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Konferensbidrag (refereegranskat)abstract
- In this paper, we introduce and investigate a method combining principle component analysis (PCA) and independent component analysis (ICA) for blind source separation (BSS). A recursive method for the PCA is applied to meet the demands of a real-time application, and likewise a modified on-line version of the information maximization principle is used. The combined PCA-ICA algorithm, first reduces the dimension of the problem and then separates the signals. Evaluation of the proposed algorithm in a real room shows superior noise suppression capabilities compared to the use of PCA or ICA individually. The proposed algorithm achieves an impressive noise suppression/separation of up to 14 dB with only two microphones. Most importantly this is achieved with negligible distortion of the recovered signal. © 2005 IEEE.
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| 7. |
- Berggren, Magnus, et al.
(författare)
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Analysis of How the Noise Level Depends on Different Activities in a Child Day-Care Center
- 2008
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Konferensbidrag (refereegranskat)abstract
- In child day-care centers the noise level can rise to high levels and in some cases become so high that the people present risk hearing damage. The purpose of this investigation was to study how the noise level depends on the different activities during the day. The study was performed at a child day-care center and 6 children and 5 adult female teachers participated. The participants had a microphone attached next to the ear connected to a wearable digital recorder. A total of 32.5 hours of data was recorded. By listening tests the recorded data could be sorted by activity and by number of people present in the same room as the test subject. Activities were classified as belonging to one of the following: outdoor activity, indoor play, singing, storytelling and gathering. Further, by listening, the data was classified in small group/large group (3 or less/more than 3). The results show that the average noise level (LAeq) for outdoor activity was the highest and was measured to 88.1 dBA (average over 7h52min). Singing was 81.5 dBA (1h26min), indoor play 81.3 dBA (19h21min), storytelling 76.6 dBA (1h09min) and gathering 75.0 dBA (2h44min). The noise level difference between all activities except between singing and indoor play and gathering and storytelling could be verified using t-test (p<0.001). Further, the results showed that the average noise level was 86.6 dBA (14h11min) for the large group and 79.6 dBA (18h21min) for the small group. This difference, of 7.0 dB was statistically validated (p<0.001) using t-test.
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| 8. |
- Berggren, Magnus, et al.
(författare)
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Audio Processing Solution for Video Conference Based Aerobics
- 2010
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Ingår i: 2010 Digest of Technical Papers, International Conference on Consumer Electronics. - Las Vegas : IEEE. - 9781424443147 - 9781424443161 ; , s. 407-408
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Konferensbidrag (refereegranskat)abstract
- In this paper an audio processing solution for video conference based aerobics is presented. The proposed solution leaves the workout music unaltered by separating it from the speech and processing each signal separately. The speech signal processing is also performed at a lower sample rate, which saves computational power. Real time evaluation of the system shows that high quality music as well as a good two-way communication is maintained during the aerobic session.
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| 9. |
- Berggren, Magnus, et al.
(författare)
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Low-complexity network echo cancellation approach for systems equipped with external memory
- 2011
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Ingår i: IEEE Transactions on Audio, Speech, and Language Processing. - : IEEE. - 1558-7916 .- 1558-7924. ; 19:8, s. 2506-2515
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Tidskriftsartikel (refereegranskat)abstract
- Long delays and sparseness characterize impulse responses in telecommunication networks and a vast number of solutions for network echo cancellation have been proposed over the years. In this paper, an approach for detecting dispersive regions of a sparse impulse response and a proportionate normalized least mean square (PNLMS)-based selective updating approach are combined with an adaptive double-talk detector to form a complete solution for echo cancellation. The proposed solution has low computational complexity and is targeted for systems equipped with external memory.
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| 10. |
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