| 1. |
- Aga, Cathrine, et al.
(författare)
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Risk of Revision Was Not Reduced by a Double-bundle ACL Reconstruction Technique: Results From the Scandinavian Registers
- 2017
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Ingår i: Clinical Orthopaedics and Related Research. - : Ovid Technologies (Wolters Kluwer Health). - 0009-921X .- 1528-1132. ; 475:10, s. 2503-2512
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Tidskriftsartikel (refereegranskat)abstract
- © 2017, The Association of Bone and Joint Surgeons®. Background: Double-bundle anterior cruciate ligament (ACL) reconstruction has demonstrated improved biomechanical properties and moderately better objective outcomes compared with single-bundle reconstructions. This could make an impact on the rerupture rate and reduce the risk of revisions in patients undergoing double-bundle ACL reconstruction compared with patients reconstructed with a traditional single-bundle technique. The National Knee Ligament Registers in Scandinavia provide information that can be used to evaluate the revision outcome after ACL reconstructions. Questions/purposes: The purposes of the study were (1) to compare the risk of revision between double-bundle and single-bundle reconstructions, reconstructed with autologous hamstring tendon grafts; (2) to compare the risk of revision between double-bundle hamstring tendon and single-bundle bone-patellar tendon-bone autografts; and (3) to compare the hazard ratios for the same two research questions after Cox regression analysis was performed. Methods: Data collection of primary ACL reconstructions from the National Knee Ligament Registers in Denmark, Norway, and Sweden from July 1, 2005, to December 31, 2014, was retrospectively analyzed. A total of 60,775 patients were included in the study; 994 patients were reconstructed with double-bundle hamstring tendon grafts, 51,991 with single-bundle hamstring tendon grafts, and 7790 with single-bundle bone-patellar tendon-bone grafts. The double-bundle ACL-reconstructed patients were compared with the two other groups. The risk of revision for each research question was detected by the risk ratio, hazard ratio, and the corresponding 95% confidence intervals. Kaplan-Meier analysis was used to estimate survival at 1, 2, and 5 years for the three different groups. Furthermore, a Cox proportional hazard regression model was applied and the hazard ratios were adjusted for country, age, sex, meniscal or chondral injury, and utilized fixation devices on the femoral and tibial sides. Results: There were no differences in the crude risk of revision between the patients undergoing the double-bundle technique and the two other groups. A total of 3.7% patients were revised in the double-bundle group (37 of 994 patients) versus 3.8% in the single-bundle hamstring tendon group (1952 of 51,991; risk ratio, 1.01; 95% confidence interval (CI), 0.73–1.39; p=0.96), and 2.8% of the patients were revised in the bone-patellar tendon-bone group (219 of the 7790 bone-patellar tendon-bone patients; risk ratio, 0.76; 95% CI, 0.54–1.06; p=0.11). Cox regression analysis with adjustment for country, age, sex, menisci or cartilage injury, and utilized fixation device on the femoral and tibial sides, did not reveal any further difference in the risk of revision between the single-bundle hamstring tendon and double-bundle hamstring tendon groups (hazard ratio, 1.18; 95% CI, 0.85–1.62; p=0.33), but the adjusted hazard ratio showed a lower risk of revision in the single-bundle bone-patellar tendon-bone group compared with the double-bundle group (hazard ratio, 0.62; 95% CI, 0.43–0.90; p=0.01). Comparisons of the graft revision rates reported separately for each country revealed that double-bundle hamstring tendon reconstructions in Sweden had a lower hazard ratio compared with the single-bundle hamstring tendon reconstructions (hazard ratio, 1.00 versus 1.89; 95% CI, 1.09–3.29; p=0.02). Survival at 5 years after index surgery was 96.0% for the double-bundle group, 95.4% for the single-bundle hamstring tendon group, and 97.0% for the single-bundle bone-patellar tendon-bone group. Conclusions: Based on the data from all three national registers, the risk of revision was not influenced by the reconstruction technique in terms of using single- or double-bundle hamstring tendons, although national differences in survival existed. Using bone-patellar tendon-bone grafts lowered the risk of revision compared with double-bundle hamstring tendon grafts. These findings should be considered when deciding what reconstruction technique to use in ACL-deficient knees. Future studies identifying the reasons for graft rerupture in single- and double-bundle reconstructions would be of interest to understand the findings of the present study. Level of Evidence: Level III, therapeutic study.
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| 2. |
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| 3. |
- Bero Bedada, Getahun, et al.
(författare)
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Short-term Exposure to Ozone and Mortality in Subjects With and Without Previous Cardiovascular Disease
- 2016
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 27:5, s. 663-669
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Exposure to ground level ozone (O3) is a public health problem associated with a range of risks across population subgroups. Our aim was to investigate the role of previous cardiovascular diseases (CVDs) in mortality related to short-term O3 exposure.METHODS: Deaths between 1990 and 2010 in Stockholm County were matched with previous hospitalizations in Swedish registries. An urban background monitoring station provided hourly values of air quality data, from which we calculated 8-hour running averages and daily 8-hour maximum. We analyzed associations between daily O3 concentrations and mortality among persons with and without previous CVD hospitalization with a generalized additive model adjusted for time trend, influenza, and weather. We also performed two-pollutant models.RESULTS: There were 302,283 nontrauma-related deaths, out of which 196,916 had previous CVD hospitalization. The mean concentration of daily maximum 8-hour O3 was 62.9 μg/m. An average 10 μg/m increase in the same and preceding day was associated with an increased mortality of 1.72% (95% confidence interval: 0.44%, 3.02%) in those with prior admission for acute myocardial infarction (AMI), which was more than three times higher than for those with no previous AMI (0.50, 95% confidence interval: 0.10%, 0.89%, P value for interaction 0.098). The association between O3 and mortality remained essentially unchanged in two-pollutant models with NO2, NOx, and PM10.CONCLUSIONS: Our study indicates that short-term exposure to O3 is associated with increased mortality in those with a previous hospitalization for AMI.
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| 4. |
- Bhalerao, RP, et al.
(författare)
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Cloning of the cpce and cpcf genes from synechococcus sp pcc-6301 and their inactivation in synechococcus sp pcc-7942
- 1994
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Ingår i: Plant Molecular Biology. - 0167-4412 .- 1573-5028. ; 26:1, s. 313-326
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Tidskriftsartikel (refereegranskat)abstract
- Two open reading frames denoted as cpcE and cpcF were cloned and sequenced from Synechococcus sp. PCC 6301. The cpcE and cpcF genes are located downstream of the cpcB2A2 gene cluster in the phycobilisome rod operon and can be transcribed independently of the upstream cpcB2A2 gene cluster. The cpcE and cpcF genes were separately inactivated by insertion of a kanamycin resistance cassette in Synechococcus sp. PCC 7942 to generate mutants R2EKM and R2FKM, respectively, both of which display a substantial reduction in spectroscopically detectable phycocyanin. The levels of beta- and alpha-phycocyanin polypeptides were reduced in the R2EKM and R2FKM mutants although the phycocyanin and linker genes are transcribed at normal levels in the mutants as in the wild type indicating the requirement of the functional cpcE and cpcF genes for normal accumulation of phycocyanin. Two biliprotein fractions were isolated on sucrose density gradient from the R2EKM/R2FKM mutants. The faster sedimenting fraction consisted of intact phycobilisomes. The slower sedimenting biliprotein fraction was found to lack phycocyanin polypeptides, thus no free phycocyanin was detected in the mutants. Characterization of the phycocyanin from the mutants revealed that it was chromophorylated, had a lambda(max) similar to that from the wild type and could be assembled into the phycobilisome rods. Thus, although phycocyanin levels are reduced in the R2EKM and R2FKM mutants, the remaining phycocyanin seems to be chromophorylated and similar to that in the wild type with respect to phycobilisome rod assembly and energy transfer to the core.
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| 5. |
- Bhalerao, RP, et al.
(författare)
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Cloning of the phycobilisome rod linker genes from the cyanobacterium synechococcus sp pcc-6301 och their inactivation in synechococcus sp pcc-7942
- 1993
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Ingår i: Molecular General Genetics. - 0026-8925 .- 1432-1874. ; 237:1-2, s. 89-96
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Tidskriftsartikel (refereegranskat)abstract
- The phycobilisome rod linker genes in the two closely related cyanobacteria Synechococcus sp. PCC 6301 and Synechococcus sp. PCC 7942 were studied. Southern blot analysis showed that the genetic organization of the phycobilisome rod operon is very similar in the two strains. The phycocyanin gene pair is duplicated and separated by a region of about 2.5 kb. The intervening region between the duplicated phycocyanin gene pair was cloned from Synechococcus sp. PCC 6301 and sequenced. Analysis of this DNA sequence revealed the presence of three open reading frames corresponding to 273, 289 and 81 amino acids, respectively. Insertion of a kanamycin resistance cassette into these open reading frames indicated that they corresponded to the genes encoding the 30, 33 and 9 kDa rod linkers, respectively, as judged by the loss of specific linkers from the phycobilisomes of the insertional mutants. Amino acid compositions of the 30 and 33 kDa linkers derived from the DNA sequence were found to deviate from those of purified 33 and 30 kDa linkers in the amounts of glutamic acid/glutamine residues. On the basis of similarity of the amino acid sequence of the rod linkers between Synechococcus sp. PCC 6301 and Calothrix sp. PCC 7601 we name the genes encoding the 30, 33 and 9 kDa linkers cpcH, cpcI and cpcD, respectively. The three linker genes were found to be co-transcribed on an mRNA of 3700 nucleotides. However, we also detected a smaller species of mRNA, of 3400 nucleotides, which would encode only the cpcH and cpcI genes. The 30 kDa linker was still found in phycobilisome rods lacking the 33 kDa linker and the 9 kDa linker was detected in mutants lacking the 33 or the 30 kDa linkers. Free phycocyanin was found in the mutants lacking the 33 or the 30 kDa linkers, whereas no free phycocyanin could be found in the mutant lacking the 9 kDa linker.
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| 6. |
- Byström, Alexandra, et al.
(författare)
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Analysis of a New Plate Thermometer - The Copper Disc Plate Thermometer
- 2015
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Ingår i: Proceedings of the International Fire Safety Symposium 2015. - : International Fire Safety Symposium. ; , s. 453-460
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Konferensbidrag (refereegranskat)abstract
- Two temperatures govern heat transfer to a surface of a solid body. One is the gas temperature which can be measured with thermocouples (TC) and the other the black body radiation temperature. The latter can also be expressed as the incident radiant heat flux. It is difficult to measure as radiometers cannot be used under hot fire conditions. Indirectly the radiation temperature can be obtained by measuring the Adiabatic Surface Temperature (AST) with plate thermometers (PT) for example as defined in the fire resistance furnace standards EN 1363-1 and ISO-834-1 combined with measurements of gas temperature with thin TC. In the test reported here a smaller gauge is used to measure adiabatic surface temperature at surfaces. It has been named copper disc Plate Thermometer (cdPT). Then a thin copper disc with an attached TC is mounted flush at the surface to obtain the AST in e.g. cone calorimeters according to ISO 5660. A main advantage of the cdPT is that it can record the AST before as well after a material has ignited. It can thereby be used to indicate ignition as well as continue recording the thermal exposure thereafter when ignition occurs the cdPT reacts immediately by displaying a quick temperature rise.
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| 7. |
- Dyrrdal, Anita Verpe, et al.
(författare)
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Changes in design precipitation over the Nordic-Baltic region as given by convection-permitting climate simulations
- 2023
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Ingår i: Weather and Climate Extremes. - 2212-0947. ; 42
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Tidskriftsartikel (refereegranskat)abstract
- The increased risk of flooding due to global warming and subsequent heavy rainfall events in the Nordic-Baltic region, call for recommendations directed at long-term planning. One example of such recommendations are climate change allowances. These are often based on expected changes in design precipitation as given by climate model simulations, and are used as a buffer on top of current design values to avoid a future increased damage potential as a consequence of climate change. We here compute expected changes in precipitation design values, so-called climate factors (CFs), for the Nordic-Baltic region, based on 3 km convection permitting simulations from the Nordic Convection Permitting Climate Projections project. These have the advantage of explicitly resolving convection, which has been shown to be the main contributor to increased rainfall. We assess the dependence of the CFs on rainfall duration, return period, and geographical location, focusing on the summer (convective) season, short durations and the high emission scenario RCP8.5. We also compare these CFs to those computed from a non-convection permitting regional climate model ensemble. We found higher CFs for the longer return period, with only few exceptions, and distinctly higher CFs going from daily to sub-daily durations. However, the different simulations give conflicting results for very short-duration rainfall (<3 h). The huge difference in the climate sensitivity of driving GCMs dominates the magnitude of estimated return levels. Our analysis is shaped by the high computational costs of running convection permitting models, resulting in a very limited ensemble (3 members) representing a single emission scenario (RCP8.5). Therefore, we believe that combining results from convection permitting simulations with a larger ensemble (21 members) of non-convection permitting simulations adds value to the assessment of robust climate change allowances for heavy precipitation in the Nordic-Baltic region.
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| 8. |
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Exhibition: Space Waves and a Tale : Hannes Alfvén (1908–1995). Nobel Prize laureate in physics 1970.
- 2022
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Konstnärligt arbeteabstract
- The exhibition Space Waves and a Tale presented parts of Alfvén's extensive research, his community engagement and last but not least, his fictional story The tale of the great computing machine from 1966. In 1970 KTH professor Hannes Alfvén (1908 – 1995) was awarded the Nobel Prize in physics for his discoveries and applications in plasma physics. The exhibition Space Waves and a Tale presented parts of Alfvén's extensive research, his community engagement and his fictional story The tale of the great computing machine from 1966.Alfvén's research allow us to explore all corners of the universe – from the auroras on earth to the auroras on other planets, from solar wind to stellar wind, from plasma phenomena in the laboratory to astrophysical plasma phenomena in ours and other galaxies.The tale of the great computing machine is a satirical tale that tells the story of a future society controlled by computers and is also the source of inspiration for an opera with the same name.As part of the exhibition Space Waves and a Tale visitors were invited to share their visions of how future technology will shape our lives and societies. Two students from the KTH School of Architecture have contributed to the exhibition by designing and building a flexible and sustainable exhibition module. Students from BOOMERANG REXUS participated with objects related to aerospace research.Space Waves and a Tale was produced by the project group for KTH 200 years anniversary celebration together with KTH Library, The Opera: The Tale of the Great Computing Machine, the Division of Space and Plasma Physics and the KTH School of Architecture.In connection with the exhibithion there was a book discussion, popular science lecture and a class visit.
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| 9. |
- Franken, Matthias K., et al.
(författare)
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Does passive sound attenuation affect responses to pitch-shifted auditory feedback?
- 2019
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Ingår i: The Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966. ; 146:6, s. 4108-4121
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Tidskriftsartikel (refereegranskat)abstract
- The role of auditory feedback in vocal production has mainly been investigated by altered auditory feedback (AAF) in real time. In response, speakers compensate by shifting their speech output in the opposite direction. Current theory suggests this is caused by a mismatch between expected and observed feedback. A methodological issue is the difficulty to fully isolate the speaker’s hearing so that only AAF is presented to their ears. As a result, participants may be presented with two simultaneous signals. If this is true, an alternative explanation is that responses to AAF depend on the contrast between the manipulated and the non-manipulated feedback. This hypothesis was tested by varying the passive sound attenuation (PSA). Participants vocalized while auditory feed- back was unexpectedly pitch shifted. The feedback was played through three pairs of headphones with varying amounts of PSA. The participants’ responses were not affected by the different levels of PSA. This suggests that across all three headphones, PSA is either good enough to make the manipulated feedback dominant, or differences in PSA are too small to affect the contribution of non-manipulated feedback. Overall, the results suggest that it is important to realize that non-manipulated auditory feedback could affect responses to AAF.
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| 10. |
- Franken, Matthias K., et al.
(författare)
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Don’t blame yourself : Conscious source monitoring modulates feedback control during speech production
- 2023
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Ingår i: Quarterly Journal of Experimental Psychology. - : SAGE Publications. - 1747-0218 .- 1747-0226. ; 76:1, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Sensory feedback plays an important role in speech motor control. One of the main sources of evidence for this is studies in which online auditory feedback is perturbed during ongoing speech. In motor control, it is therefore crucial to distinguish between sensory feedback and externally generated sensory events. This is called source monitoring. Previous altered feedback studies have taken non-conscious source monitoring for granted, as automatic responses to altered sensory feedback imply that the feedback changes are processed as self-caused. However, the role of conscious source monitoring is unclear. The current study investigated whether conscious source monitoring modulates responses to unexpected pitch changes in auditory feedback. During the first block, some participants spontaneously attributed the pitch shifts to themselves (self-blamers) while others attributed them to an external source (other-blamers). Before Block 2, all participants were informed that the pitch shifts were experimentally induced. The self-blamers then showed a reduction in response magnitude in Block 2 compared with Block 1, while the other-blamers did not. This suggests that conscious source monitoring modulates responses to altered auditory feedback, such that consciously ascribing feedback to oneself leads to larger compensation responses. These results can be accounted for within the dominant comparator framework, where conscious source monitoring could modulate the gain on sensory feedback. Alternatively, the results can be naturally explained from an inferential framework, where conscious knowledge may bias the priors in a Bayesian process to determine the most likely source of a sensory event.
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