| 41. |
- Rest, A., et al.
(författare)
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DIRECT CONFIRMATION OF THE ASYMMETRY OF THE CAS A SUPERNOVA WITH LIGHT ECHOES
- 2011
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 732:1, s. 3-
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Tidskriftsartikel (refereegranskat)abstract
- We report the first detection of asymmetry in a supernova (SN) photosphere based on SN light echo (LE) spectra of Cas A from the different perspectives of dust concentrations on its LE ellipsoid. New LEs are reported based on difference images, and optical spectra of these LEs are analyzed and compared. After properly accounting for the effects of finite dust-filament extent and inclination, we find one field where the He I lambda 5876 and Ha features are blueshifted by an additional similar to 4000 km s(-1) relative to other spectra and to the spectra of the Type IIb SN 1993J. That same direction does not show any shift relative to other Cas A LE spectra in the Ca II near-infrared triplet feature. We compare the perspectives of the Cas A LE dust concentrations with recent three-dimensional modeling of the SN remnant (SNR) and note that the location having the blueshifted He I and Ha features is roughly in the direction of an Fe-rich outflow and in the opposite direction of the motion of the compact object at the center of the SNR. We conclude that Cas A was an intrinsically asymmetric SN. Future LE spectroscopy of this object, and of other historical SNe, will provide additional insight into the connection of the explosion mechanism to SN then to SNR, as well as give crucial observational evidence regarding how stars explode.
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| 42. |
- Sneddon, Alan A, et al.
(författare)
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Effect of a conjugated linoleic acid and omega-3 fatty acid mixture on body composition and adiponectin
- 2008
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Ingår i: Obesity. - : Wiley. - 1930-739X .- 1930-7381. ; 16:5, s. 1019-1024
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to determine the effect of supplementation with conjugated linoleic acids (CLAs) plus n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) on body composition, adiposity, and hormone levels in young and older, lean and obese men. Young (31.4 +/- 3.9 years) lean (BMI, 23.6 +/- 1.5 kg/m(2); n = 13) and obese (BMI, 32.4 +/- 1.9 kg/m(2); n = 12) and older (56.5 +/- 4.6 years) lean (BMI, 23.6 +/- 1.5 kg/m(2); n = 20) and obese (BMI, 32.0 +/- 1.6 kg/m(2); n = 14) men participated in a double-blind placebo-controlled, randomized crossover study. Subjects received either 6 g/day control fat or 3 g/day CLA (50:50 cis-9, trans-11: trans-10, cis-12) and 3 g/day n-3 LC-PUFA for 12 weeks with a 12-week wash-out period between crossovers. Body composition was assessed by dual-energy X-ray absorptiometry. Fasting adiponectin, leptin, glucose, and insulin concentrations were measured and insulin resistance estimated by homeostasis model assessment for insulin resistance (HOMA-IR). In the younger obese subjects, CLA plus n-3 LC-PUFA supplementation compared with control fat did not result in increased abdominal fat and raised both fat-free mass (2.4%) and adiponectin levels (12%). CLA plus n-3 LC-PUFA showed no significant effects on HOMA-IR in any group but did increase fasting glucose in older obese subjects. In summary, supplementation with CLA plus n-3 LC-PUFA prevents increased abdominal fat mass and raises fat-free mass and adiponectin levels in younger obese individuals without deleteriously affecting insulin sensitivity, whereas these parameters in young and older lean and older obese individuals were unaffected, apart from increased fasting glucose in older obese men.
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| 43. |
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| 44. |
- Tsofliou, Fotini, et al.
(författare)
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Modulation of Fasted and Postprandial Plasma Lipids in Healthy Volunteers by a Dietary Mixture of Omega-3 Fatty Acids and Conjugated Linoleic Acid
- 2009
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Ingår i: Journal of Food Lipids. - : Wiley. - 1065-7258 .- 1745-4522. ; 16:4, s. 499-513
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Tidskriftsartikel (refereegranskat)abstract
- Effects of a dietary combination of omega-3 polyunsaturated fatty acids (n-3-PUFA) and conjugated linoleic acids (CLAs) on fasting and postprandial plasma lipids was investigated in healthy volunteers with different ages and body mass index (BMI). Lean (BMI 20-26 kg/m2) and obese (BMI 29-35 kg/m2), young (20-37 years) and older (50-65 years) men consumed 3 g/day each of CLA and n-3-PUFA or 6 g/day control oil for 12 weeks in a double-blinded, placebo-controlled, randomized crossover study. In older lean subjects, CLA/n-3-PUFA supplementation reduced fasting nonesterified fatty acids (NEFAs) concentrations compared with the control oil (P < 0.05). However, in older obese subjects, CLA/n-3-PUFA increased fasting low-density lipoprotein cholesterol (P < 0.05) and postprandial total cholesterol levels (P < 0.05). In young lean subjects, CLA/n-3-PUFA reduced postprandial NEFA levels (P < 0.05) whereas in young obese subjects, postprandial total cholesterol and triacylglycerols were lowered (both P < 0.05). Therefore, a dietary combination of CLA together with n-3-PUFA may have favorable effects on plasma lipids in young and older lean men but detrimental effects in older obese men. PRACTICAL APPLICATIONS This study suggests that where individuals consume a combination of both omega-3 polyunsaturated fatty acids and conjugated linoleic acid supplements in order to obtain potential additive beneficial effects of each lipid on adiposity and health, this particular fatty acid combination may have harmful effects on plasma lipid biomarkers of cardiovascular disease in older obese men.
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| 45. |
- Zokaei, Sepideh, 1991, et al.
(författare)
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Tuning of the elastic modulus of a soft polythiophene through molecular doping
- 2022
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Ingår i: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6355 .- 2051-6347. ; 9:1, s. 433-443
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Tidskriftsartikel (refereegranskat)abstract
- Molecular doping of a polythiophene with oligoethylene glycol side chains is found to strongly modulate not only the electrical but also the mechanical properties of the polymer. An oxidation level of up to 18% results in an electrical conductivity of more than 52 S cm(-1) and at the same time significantly enhances the elastic modulus from 8 to more than 200 MPa and toughness from 0.5 to 5.1 MJ m(-3). These changes arise because molecular doping strongly influences the glass transition temperature T-g and the degree of pi-stacking of the polymer, as indicated by both X-ray diffraction and molecular dynamics simulations. Surprisingly, a comparison of doped materials containing mono- or dianions reveals that - for a comparable oxidation level - the presence of multivalent counterions has little effect on the stiffness. Evidently, molecular doping is a powerful tool that can be used for the design of mechanically robust conducting materials, which may find use within the field of flexible and stretchable electronics.
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- Ben-Ami, Sagi, et al.
(författare)
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ULTRAVIOLET SPECTROSCOPY OF TYPE IIB SUPERNOVAE : DIVERSITY AND THE IMPACT OF CIRCUMSTELLAR MATERIAL
- 2015
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 803:1
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Tidskriftsartikel (refereegranskat)abstract
- We present new Hubble Space Telescope (HST) multi-epoch ultraviolet (UV) spectra of the bright Type IIb SN 2013df, and undertake a comprehensive analysis of the set of four SNe IIb for which HST UV spectra are available (SN 1993J, SN 2001ig, SN 2011dh, and SN 2013df). We find strong diversity in both continuum levels and line features among these objects. We use radiative-transfer models that fit the optical part of the spectrum well, and find that in three of these four events we see a UV continuum flux excess, apparently unaffected by line absorption. We hypothesize that this emission originates above the photosphere, and is related to interaction with circumstellar material (CSM) located in close proximity to the SN progenitor. In contrast, the spectra of SN 2001ig are well fit by single-temperature models, display weak continuum and strong reverse-fluorescence features, and are similar to spectra of radioactive 56Ni-dominated SNe Ia. A comparison of the early shock-cooling components in the observed light curves with the UV continuum levels which we assume trace the strength of CSM interaction suggests that events with slower cooling have stronger CSM emission. The radio emission from events having a prominent UV excess is perhaps consistent with slower blast-wave velocities, as expected if the explosion shock was slowed down by the CSM that is also responsible for the strong UV, but this connection is currently speculative as it is based on only a few events.
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| 50. |
- Caravaggio, Fernando, et al.
(författare)
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Trait impulsivity is not related to post-commissural putamen volumes : A replication study in healthy men
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- High levels of trait impulsivity are considered a risk factor for substance abuse and drug addiction. We recently found that non-planning trait impulsivity was negatively correlated with post-commissural putamen volumes in men, but not women, using the Karolinska Scales of Personality (KSP). Here, we attempted to replicate this finding in an independent sample using an updated version of the KSP: the Swedish Universities Scales of Personality (SSP). Data from 88 healthy male participants (Mean Age: 28.16 +/- 3.34), who provided structural T1-weighted magnetic resonance images (MRIs) and self-reported SSP impulsivity scores, were analyzed. Striatal sub-region volumes were acquired using the Multiple Automatically Generated Templates (MAGeT-Brain) algorithm. Contrary to our previous findings trait impulsivity measured using SSP was not a significant predictor of post-commissural putamen volumes (beta = .14, df = 84, p = .94). A replication Bayes Factors analysis strongly supported this null result. Consistent with our previous findings, secondary exploratory analyses found no relationship between ventral striatum volumes and SSP trait impulsivity (beta = -.05, df = 84, p = .28). An exploratory analysis of the other striatal compartments showed that there were no significant associations with trait impulsivity. While we could not replicate our previous findings in the current sample, we believe this work will aide future studies aimed at establishing meaningful brain biomarkers for addiction vulnerability in healthy humans.
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