| 121. |
- Hugues, John P., et al.
(författare)
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Chandra Observations of Type Ia Supernovae: Upper Limits to the X-Ray Flux of SN 2002bo, SN 2002ic, SN 2005gj, and SN 2005ke
- 2007
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Ingår i: The Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 670:2, s. 1260-1274
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Tidskriftsartikel (refereegranskat)abstract
- We set sensitive upper limits to the X-ray emission of four Type Ia supernovae (SNe Ia) using the Chandra X-Ray Observatory. SN 2002bo, a normal, although reddened, nearby SN Ia, was observed 9.3 days after explosion. For an absorbed, high-temperature bremsstrahlung model the flux limits are 3.2×10-16 ergs cm-2 s-1 (0.5-2 keV band) and 4.1×10-15 ergs cm-2 s-1 (2-10 keV band). Using conservative model assumptions and a 10 km s-1 wind speed, we derive a mass-loss rate of M˙~2×10-5 Msolar yr-1, which is comparable to limits set by the nondetection of Hα lines from other SNe Ia. Two other objects, SN 2002ic and SN 2005gj, observed 260 and 80 days after explosion, respectively, are the only SNe Ia showing evidence for circumstellar interaction. The SN 2002ic X-ray flux upper limits are ~4 times below predictions of the interaction model currently favored to explain the bright optical emission. To resolve this discrepancy, we invoke the mixing of cool dense ejecta fragments into the forward shock region, which produces increased X-ray absorption. A modest amount of mixing allows us to accommodate the Chandra upper limit. SN 2005gj is less well studied at this time. Assuming the same circumstellar environment as for SN 2002ic, the X-ray flux upper limits for SN 2005gj are ~4 times below the predictions, suggesting that mixing of cool ejecta into the forward shock has also occurred here. Our reanalysis of Swift and Chandra data on SN 2005ke does not confirm a previously reported X-ray detection. The host galaxies NGC 3190 (SN 2002bo) and NGC 1371 (SN 2005ke) each harbor a low-luminosity [LX~(3-4)×1040 ergs s-1] active nucleus in addition to widespread diffuse soft X-ray emission.
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| 122. |
- Högfeldt, Anna-Karin, et al.
(författare)
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Program leadership from a Nordic perspective - Managing education development
- 2012
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Ingår i: Proceedings of 8th International CDIO Conference, Brisbane, Australia.
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Konferensbidrag (refereegranskat)abstract
- Nordic Five Tech (N5T) is a strategic alliance between five technical universities in Denmark, Finland, Norway and Sweden. The overall aim is to “utilize shared and complementary strengths and create synergy within education, research and innovation”. In this paper we focus on university educational development issues by investigating the program leadership at five Nordic technical universities. Specifically, the paper compares definitions, views and experiences of education leadership in the Nordic Five Tech (N5T) universities. The paper does this by, first, reviewing the definitions of roles and responsibilities for program directors at each university, and second, by presenting results from a survey carried out in March 2012 among program directors at the N5T universities. Based on this data, we analyze how program directors experience their role, their possibilities to lead, and their opportunities of learning to lead. How is time for reflection and development as leaders handled at the different universities? The paper goes on to consider what impact the mandate of the leadership role has on the possibilities for developing educational programs. For instance, how can program directors ensure that learning objectives concerning generic skills and abilities are reached? How can program directors drive implementation of integrative and value-oriented topics such as sustainable development, innovation and entrepreneurship?
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| 123. |
- Indebetouw, R., et al.
(författare)
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DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA
- 2014
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Ingår i: The Astrophysical Journal Letters. - : Institute of Physics (IOP). - 2041-8205. ; 782:1, s. L2-
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Tidskriftsartikel (refereegranskat)abstract
- Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 mu m, 870 mu m, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M-circle dot). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.
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| 124. |
- Iping, Rosina C., et al.
(författare)
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Search for O VI Emission from the Shocked Circumstellar Ring of SN 1987A
- 2007
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Ingår i: SUPERNOVA 1987A: 20 YEARS AFTER: Supernovae and Gamma-Ray Bursters. - : AIP. - 9780735404489 ; , s. 182-184
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A search for O VI 1032-38 Å emission from the circumstellar shock interaction zones of SN 1987A was made with the FUSE satellite. The shock interaction of supernova ejecta with the dense inner ring began in the mid-1990s. Broad (FWHM ~300 km s−1) emission from optical coronal lines (e.g. [Fe X], [Fe XI], and [Fe XIV]) has emerged and increased exponentially in strength. O VI emission is expected to track the coronal lines and is expected to be the primary cooling transition for the million-degree shocked gas. In the most recent FUSE observation of SN 1987A, June 2004, a weak broad O VI feature may be present. An upper limit on the intrinsic O VI flux is ~1×10−13 erg cm−2 s−1 (corrected for foreground Galactic and LMC extinction). A follow-up observation of planned for mid-2007.
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| 125. |
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| 126. |
- Johansson, Anja, et al.
(författare)
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Ergonomic Evaluation of Two Different Locations of the Scales in a Supermarket Checkout System
- 1993
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Ingår i: Advances in Industrial Ergonomics and Safety V. ; , s. 667-674
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Konferensbidrag (refereegranskat)abstract
- The aim of this pilot study was to ergonomically evaluate the effect of the location of the scales in a supermarket checkout system. A location of the scales to the left of the cashier was compared with a location under the conveyor belt. Two cashiers were videotaped while working with the two scale locations, in both sitting and standing working postures. Analysis of the video tapes was performed using the WOPALAS method, the VIRA method, and by noting certain positions of the left arm. The left wrist movements were registered by a two-dimensional goniometer. The results indicate that the location under the conveyor belt is somewhat more ergonomically favourable. The improvement is more pronounced for the cashier with a greater reach.
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| 127. |
- Johansson, Anja, et al.
(författare)
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Evaluation of a Workplace Redesign of a Grocery Checkout System
- 1998
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Ingår i: Applied Ergonomics. - 1872-9126. ; 29:4, s. 261-266
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the effects on the working postures and movements of a cashier when two different locations of the scales (one to the left of the cashier, the other under the conveyer belt in front of the cashier) were used in a grocery checkout system. Two cashiers (of average stature and short stature) were videotaped while working, in both sitting and standing working positions. Analysis of the video tapes was performed using the WOPALAS method and video observations. The results of the study show that the design of the checkout system with the scales under the conveyer belt provides a more favourable working position for both the taller and the shorter cashier. Additionally, the results indicate that a standing position is more favourable than a sitting one for the taller cashier while for the shorter cashier the sitting position is better.
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| 128. |
- Jufvas, Åsa, et al.
(författare)
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Global differences in specific histone H3 methylation are associated with overweight and type 2 diabetes.
- 2013
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Ingår i: Clinical Epigenetics. - : BioMed Central. - 1868-7083 .- 1868-7075. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epidemiological evidence indicates yet unknown epigenetic mechanisms underlying a propensity for overweight and type 2 diabetes. We analyzed the extent of methylation at lysine 4 and lysine 9 of histone H3 in primary human adipocytes from 43 subjects using modification-specific antibodies.RESULTS: The level of lysine 9 dimethylation was stable, while adipocytes from type 2 diabetic and non-diabetic overweight subjects exhibited about 40% lower levels of lysine 4 dimethylation compared with cells from normal-weight subjects. In contrast, trimethylation at lysine 4 was 40% higher in adipocytes from overweight diabetic subjects compared with normal-weight and overweight non-diabetic subjects. There was no association between level of modification and age of subjects.CONCLUSIONS: The findings define genome-wide molecular modifications of histones in adipocytes that are directly associated with overweight and diabetes, and thus suggest a molecular basis for existing epidemiological evidence of epigenetic inheritance.
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| 129. |
- Jungner, Måns, 1971-, et al.
(författare)
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A retrospective comparison of oxidized and turned implants with respect to implant survival, marginal bone level and peri-implant soft tissue conditions after at least 5 years in function
- 2014
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 16:2, s. 230-237
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long-term clinical follow-up studies comparing different implant surfaces with regard to survival and marginal conditions are rare. Objectives: The objective of this study was to compare the clinical performance of turned and oxidized implants after more than 5 years of loading Material and Methods: One hundred three patients (43 men, 60 women; mean age 67.4 years, range 32–90) previously treated with 287 implants (Nobel Biocare AB, Gothenburg, Sweden), 133 with turned surface (MKIII, Nobel Biocare AB) and 154 with an oxidized surface (MKIII, TiUnite, Nobel Biocare AB) were examined after at least 5 years of loading (mean 82 months, range 60–93 months). The implants had been used for support of single crowns (33 patients/36 implants), partial bridges (39 patients/103 implants), or full bridges (31 patients/148 implants) following an early loading protocol (14 patients /54 implants), a one-stage protocol (32 patients/59 implants) or a two-stage protocol (57 patients/174 implants). Clinical examinations of bleeding on probing (BoP) and pocket depth (PD) were performed. Intraoral radiographs were used for assessments of marginal bone levels (MBLs). Results: Seven turned implants and one oxidized implant failed, giving overall cumulative survival rates of 94.7 and 99.4%, respectively. There were no differences for BoP scores (0.5 1 0.7 vs 0.4 1 0.6) and PD measurements (1.7 1 0.8 mm vs 1.8 1 1.0 mm) parameters when comparing turned and oxidized implants, respectively. The mean MBL was 1.8 1 0.8 mm and 2.0 1 0.9 mm for turned and oxidized implants, respectively, after more than 5 years in function (NS). Frequency distribution of MBL loss showed no statistically significant differences between the two surfaces. A total of four implants (1.4%) (three oxidized and one turned) showed a PD > 3 mm, MBL > 4 mm, and BoP. However, none of these were associated with suppuration on examination. Conclusion: The present study does not state any differences in implant failure, MBL, presence of bleeding or PD around implants when comparing turned and oxidized titanium implants after at least 5 years of function.
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| 130. |
- Jungner, Måns, 1971-
(författare)
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Healing of endosseous implants with different surface characteristics in grafted and non-grafted bone : clinical and experimental studies
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aims: This study uses radiological and clinical evaluations of the healing of endosseous titanium implants presented with different surface characteristics in the clinical situation (paper I-III) and experimentally to describe the early bone healing in maxillary sinus membrane elevation with and without the use of grafting material (paper IV).Material and methods: In paper I, 136 patients were treated with 394 dental implants – 199 were oxidized titanium implants (Nobel Biocare TiUnite) and 195 were turned titanium surface implants (Nobel Biocare Mark III). Implant survival rates were retrospectively investigated after a minimum of five months after functional loading of the implants. At the five-year follow-up (paper II), eight patients were deceased and 128 were invited. Twenty-five patients refrained from participating in the study. The remaining 103 patients (287 implants – 133 with a turned surface and 154 with an oxidized surface) were examined after at least five years of functional loading. Clinical examinations of bleeding on probing (BoP) and pocket depth (PD) were performed. Intraoral radiographs were used to assess marginal bone levels (MBLs). In paper III, 28 patients were subjected to autologous bone graft and delayed implant placement, with a total of 92 dental implants. Thirteen patients received 47 implants with a turned surface and 15 patients received 45 implants with an oxidized surface. After a minimum of five years of functional loading, all patients were clinically examined regarding PD and BoP. The MBL was measured in intraoral radiographs. Cone beam computed tomography (CBCT) was used to evaluate the apical bone level (ABL) of the implants and intra-sinus conditions. The experimental study (paper IV) used nine adult male tufted capuchin primates (Cebus apella). Eight animals were subjected to bilateral maxillary sinus membrane elevation using a lateral replaceable bone window technique. One oxidized dental implant was placed in the residual bone of the sinus floor, protruding into the maxillary sinus cavity on both sides. In four animals, one sinus was left without any additional treatment, while the contralateral sinus was filled with autologous bone grafts from the tibia. In two animals, the implants were inserted under the elevated sinus membrane on both sides. In two animals, the sinus membrane was totally removed bilaterally before placement of implants. The animals were euthanized after 10 (n=4) or 45 (n=4) days. One non-operated animal representing pristine tissue conditions served as the control. The maxillary sinuses with implants were retrieved and further processed to prepare light microscopic ground sections or decalcified sections for immunohistochemical analyses. Results: In paper I seven implants were lost in five patients – six in the maxilla and one in the mandible. All failed implants were Mark III turned implants. The overall implant survival rate was 98.2% with a survival rate of 96.4% for implants with turned surface after a minimum of five months after functional loading. In paper II, one additional oxidized implant failed, giving an overall cumulative survival rate of 94.7 and 99.4%, respectively, after at least five years of functional loading. There was no difference for BoP, PD, or MBL between turned and oxidized implants. A total of two implants, three oxidized and one turned, showed a PD > 3 mm, MBL > 4 mm, and BoP. However, none of these were associated with suppurative infection on examination. In paper III no difference was found between the two implants surfaces used in terms of PD, BoP, MBL, or ABL. Pathological reactions to the sinus membrane were seen in four of the patients (14%). Radiographic signs of sinus pathology were not correlated to either survival rate of the implants or any of the investigated parameters. In the experimental paper IV, bone formation started from the bottom of the sinus floor, sprouting into the granulation tissue along the implant surface under the elevated membrane irrespective of time and surgical technique. Bone formation was not seen in direct conjunction with the sinus membrane. A distinct expression of osteopontin was observed in the serous glands of deeper portion of the lamina propria in direct connection with the elevated sinus membrane and close to the implant within all groups.Conclusion: After more than five years of function in non-grafted patients, oxidized implants had a survival rate higher than turned implants, although this was not statistically significant. No difference was found in MBL, PD, or BoP. Grafting of the maxillary sinus floor with intra- orally harvested bone and delayed placement of either turned or oxidized implants resulted in equally high long-term survival rates, MBL, ABL, and BoP. Pathological findings in the maxillary sinus cavity, in terms of sinus membrane health, are few and not correlated to any of the other investigated parameters. In the experimental study bone formation after sinus membrane elevation with or without additional bone grafts started at the sinus floor and sprouted into the elevated space along the implant surface. Removal of the membrane resulted in less bone formation. The sinus membrane did not seem to present osteoinductive potential in sinus membrane elevation procedures.
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